JP6500541B2 - Nonaqueous Electrolyte and Nonaqueous Electrolyte Battery Using the Same - Google Patents

Description

  The present invention relates to a non-aqueous electrolytic solution and a non-aqueous electrolytic solution battery using the same.

With the rapid progress of portable electronic devices such as mobile phones and laptop personal computers, there is an increasing demand for higher capacity batteries used for the main power supply and backup power supply. Non-aqueous electrolyte batteries such as lithium ion secondary batteries having higher energy density than hydrogen batteries are attracting attention.
As electrolyte solution of lithium ion secondary battery, electrolytes such as LiPF 6, LiBF 4, LiN (CF 3 SO 2) 2, LiCF 3 (CF 2) 3 SO 3, etc., high permittivity solvents such as ethylene carbonate and propylene carbonate, dimethyl carbonate, diethyl carbonate, A non-aqueous electrolytic solution dissolved in a mixed solvent with a low viscosity solvent such as ethyl methyl carbonate is mentioned as a representative example.

  In addition, as a negative electrode active material of a lithium ion secondary battery, a carbonaceous material capable of mainly absorbing and desorbing lithium ions is used, and natural graphite, artificial graphite, amorphous carbon and the like are listed as representative examples. Be Furthermore, in order to increase the capacity, metal or alloy negative electrodes using silicon or tin are also known. As the positive electrode active material, a transition metal complex oxide capable of mainly absorbing and releasing lithium ions is used, and cobalt, nickel, manganese, iron and the like can be mentioned as typical examples of the transition metal.

Since such a lithium ion secondary battery uses a highly active positive electrode and a negative electrode, it is known that the charge / discharge capacity is reduced due to a side reaction between the electrode and the electrolytic solution, and the battery characteristics are improved. In order to achieve this, various studies have been made on nonaqueous solvents and electrolytes.
In Patent Documents 1 to 3, attempts have been made to improve the cycle characteristics of a battery by adding a malonic acid ester compound to a non-aqueous electrolytic solution.

  In Patent Documents 4 and 5, attempts have been made to improve battery characteristics at high temperatures and improve cycle characteristics by using a fluorinated malonic acid ester compound and an electrolytic solution added.

  In Patent Document 6, by adding a malonic ester or tricarboxylic acid ester compound to an electrolytic solution, a study to improve the reduction resistance of the electrolytic solution and a study to suppress a leakage current during constant voltage charging of an electric double layer capacitor Is being done.

Japanese Patent Application Laid-Open No. 11-135148 Japanese Patent Laid-Open Publication No. 2000-223153 Japanese Patent Application Laid-Open No. 2004-172120 Japanese Patent Application Laid-Open No. 11-7978 Japanese Patent Application Laid-Open No. 2005-317403 International Publication Number WO2008-001955

However, in recent years, the demand for improving the characteristics of lithium non-aqueous electrolyte secondary batteries is increasing, and all the performances such as high temperature storage characteristics, energy density, output characteristics, life, high speed charge / discharge characteristics, low temperature characteristics etc. It is required to have a high level, but it has not been achieved yet. There is a trade-off between durability performance including high temperature storage characteristics and performance such as capacity, resistance, output characteristics, etc., and there is a problem that the balance of overall performance is bad.

  The present invention has been made in view of the above problems. That is, it is an object of the present invention to provide a battery having a well-balanced overall performance with respect to performances such as cycle characteristics, battery swelling suppression, cycle gas suppression, high temperature storage characteristics and the like in non-aqueous electrolyte secondary batteries.

  The inventors of the present invention conducted intensive studies to achieve the above object, and as a result, it is a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of inserting and extracting metal ions, and a non-aqueous electrolyte solution. The aqueous electrolyte contains a compound represented by the general formula (A) together with the electrolyte and the non-aqueous solvent, and the negative electrode has a negative electrode active material containing metal particles that can be alloyed with Li and graphite particles It has been found that the above-mentioned problems can be solved by using a non-aqueous electrolytic solution battery characterized by the above, and the present invention described below has been completed.

(In the formula (A), R ₁ is an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, an alkenyl group or an alkynyl group, or a carbon number 6 which may be substituted with a halogen atom 20 is an aromatic hydrocarbon group, and n is an integer of 0 to 1. R ₂ is an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, an alkenyl group or an alkynyl group, or a halogen R 6 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may be substituted by an atom, provided that when n = 0, R ₂ has a halogen atom, and X ₁ and X ₂ each independently represent A hydrogen atom, a halogen atom, an alkoxycarbonyl group having 1 to 12 carbon atoms which may be substituted by a halogen atom, or an acyl group is shown)

The gist of the present invention is as follows.
(A) A non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of absorbing and releasing metal ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution together with the electrolyte and the non-aqueous solvent is represented by the following general formula (A) A non-aqueous electrolytic solution battery comprising the compound of claim 1 and the negative electrode containing a negative electrode active material containing metal particles that can be alloyed with Li and graphite particles.

(R ¹ and R ² independently represent an alkyl group, an alkenyl group, an alkynyl group, or an aromatic hydrocarbon group which may be substituted with a halogen atom. X ¹ and X ² are independently hydrogen atom,
A halogen atom, an alkoxycarbonyl group which may be substituted by a halogen atom, and an acyl group are shown. n represents an integer of 0 to 1; However, when n = 0, R ² represents an alkyl group substituted with a halogen atom, an alkenyl group, an alkynyl group or an aromatic hydrocarbon group. )

(B) In the non-aqueous electrolyte solution, the content of the compound represented by the general formula (A) is 0.001% by mass to 10% by mass with respect to the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte battery as described in (a).
Liquid battery.
(C) The non-aqueous electrolytic solution is a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, an acid anhydride compound, an isocyanate compound, a cyclic sulfonic acid ester compound, a compound having an isocyanuric acid skeleton and a nitrile The non-aqueous electrolyte battery according to (a) or (b), containing at least one compound selected from the group consisting of compounds.

  (D) In the non-aqueous electrolyte, a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, an acid anhydride compound, an isocyanate compound, a cyclic sulfonic acid ester compound, a compound having an isocyanuric acid skeleton and cyano The content of at least one compound selected from the group consisting of compounds having a group is 0.001% by mass or more and 10% by mass or less with respect to the total amount of the non-aqueous electrolytic solution described in (c) Non-aqueous electrolyte batteries.

(E) The metal particle which can be alloyed with Li is at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn and W or a metal compound thereof The non-aqueous electrolyte solution battery as described in a)-(d).
(F) The non-aqueous electrolyte battery according to (a) to (e), wherein the metal particle that can be alloyed with Li is Si or a metal oxide with Si.
(G) The content of the metal particles which can be alloyed with Li is 0.1 to 25% by mass with respect to the total of the metal particles which can be alloyed with Li and the graphite particles. The non-aqueous electrolyte battery according to f).

According to the present invention, with respect to lithium non-aqueous electrolyte secondary batteries, it is possible to provide a battery with well-balanced overall performance in terms of performance such as cycle characteristics, battery swelling suppression, cycle gas suppression, high temperature storage characteristics .
Function and principle of the non-aqueous electrolyte secondary battery produced using the non-aqueous electrolyte solution of the present invention and the non-aqueous electrolyte secondary battery of the present invention becoming a secondary battery with a good balance of overall performance Although it is not clear, it is considered as follows. However, the present invention is not limited to the operation and principle described below.

In Patent Documents 1-5, attempts have been made to improve the cycle characteristics and the discharge characteristics at high temperatures by containing a malonic acid ester compound and a fluoromalonic acid ester compound in the electrolytic solution, but any of the examples is described. Carbon and metal lithium are used, and the property improvement effect of the Si-based active material has not been clarified at all.
In Patent Document 6, the characteristic improvement by compound addition is clarified only when using an electric double layer capacitor or a carbon negative electrode, but the effect of using a Si-based active material for a lithium secondary battery or a negative electrode is as follows: It is not made clear at all like the patent documents 1-5.

Si-based active materials are attracting attention as next-generation negative electrodes because they have a very large theoretical capacity per weight and volume of the negative electrode active material compared to currently used carbon negative electrodes. However, the Si-based active material has a very large volume change (100 to 300%) due to lithium ion absorption / desorption, and along with this, the electron conduction path in the electrode is broken, and the mixture electrode such as particle pulverization etc. There is a problem such as deterioration of the substance. By repeating charging and discharging and pulverizing the particles, a highly active new surface (dangling bond) is exposed. The reaction of the exposed surface with the electrolytic solution causes deterioration of the surface of the active material, resulting in a decrease in capacity of the active material and a shift in charge depth of the positive electrode and the negative electrode, resulting in a problem of poor cycle characteristics. To address this problem, in the present invention, the compound represented by the formula (A) is contained in the non-aqueous electrolytic solution. The active methylene site of the compound represented by the formula (A) is reduced on the surface of the negative electrode active material to generate an anion in the compound, and the reduced form interacts with the Si surface to activate the Si surface. To reduce the reductive decomposition reaction of the electrolytic solution and the deterioration of Si. Furthermore, when X ₁ and X ₂ in the formula (A) are an electron-withdrawing halogen, an alkoxycarbonyl group or an acyl group, the activity of methylene is enhanced and a reductant is generated, so that the Si surface and the electrolyte The reaction is further suppressed.

  In order to solve the above problems, the present invention is a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of inserting and extracting metal ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte together with the electrolyte and the non-aqueous solvent A non-aqueous electrolytic solution battery comprising a compound represented by the general formula (A) and having a negative electrode active material containing a metal particle which can be alloyed with Li and a graphite particle . As a result, they have found that not only the cycle characteristics but also various characteristics such as battery swelling suppression, cycle gas suppression, high temperature storage characteristics are improved, and the present invention has been completed.

Hereinafter, although an embodiment of the present invention is described, the present invention is not limited to the following embodiment, and can be arbitrarily modified and implemented without departing from the scope of the present invention.
Moreover, "weight%", "weight ppm" and "weight part" and "mass%", "mass ppm" and "mass part" are respectively synonymous here. Moreover, when it only describes as ppm, it shows the thing of "weight ppm."
1. Non-aqueous electrolyte solution 1-1. Nonaqueous Electrolyte Solution of the Present Invention The nonaqueous electrolyte solution of the present invention contains a compound represented by the following general formula (A) together with an electrolyte and a nonaqueous solvent.
1-1-1. Compound Represented by General Formula (A)

In the above general formula (A), R ¹ and R ² independently represent an alkyl group which may be substituted by a halogen atom, an alkenyl group, an alkynyl group or an aromatic hydrocarbon group. X ¹ and X ² independently represent a hydrogen atom, a halogen atom, an alkoxycarbonyl group which may be substituted with a halogen atom, or an acyl group. n represents an integer of 0 to 1; However, when n = 0, R ² represents an alkyl group substituted with a halogen atom, an alkenyl group, an alkynyl group or an aromatic hydrocarbon group.

As an alkyl group which may be substituted by a halogen atom, an alkyl group having 1 to 10 carbon atoms is preferable, and as a more preferable example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group And linear or branched alkyl groups such as sec-butyl group and tert-butyl group, fluorine-substituted alkyl groups, and cyclic alkyl groups such as cyclopropyl group, cyclopentyl group and cyclohexyl group.

  As a specific example of the alkenyl group which may be substituted by a halogen atom, an alkenyl group having 2 to 10 carbon atoms is preferable, and as a more preferable specific example, a vinyl group, an allyl group, a methallyl group, a 1-propenyl group, a fluorine-substituted And vinyl, allyl, methallyl, alkyl and the like.

As a specific example of the alkynyl group which may be substituted by the halogen atom, a C2-C10 alkynyl group is preferable, A ethynyl group, a propargyl group, 1-propynyl group etc. are mentioned as a more preferable specific example.
As a specific example of an aromatic hydrocarbon group, a C6-C20 aromatic hydrocarbon is preferable, and a phenyl group, a tolyl group, a benzyl group, a phenethyl group etc. are mentioned as a preferable example rather than a group.

The type of the alkoxycarbonyl group which may be substituted by a halogen atom and the acyl group are not particularly limited as long as they are groups represented by -COOR and -COR, respectively, and those having 2 to 10 carbon atoms are preferable, _{examples, -COOCH 3, -COOCH 2 CH 3} , -COCH 3, is like -COCH ₂ CH _3, -COOCH _3, preferably -COOCH ₂ CH _3, more preferably -COOCH ₂ CH _3.

Among these substituents, methyl, ethyl, vinyl, allyl, methallyl, propargyl, phenyl and the like which may be substituted with fluorine are preferable. In the case of a phenyl group, "optionally substituted with a halogen atom" also includes a halogenated alkyl group substituent such as a trifluoromethyl group. Further, X ₁ and X ₂ are preferably a fluorine atom, an alkoxycarbonyl group, an acyl group or the like from the viewpoint of characteristic improvement.

As the compound used in the present invention, a compound represented by the general formula (A) is used, and specific examples include a compound having the following structure.
<Compound of n = 0 in General Formula (A)>

<Compound of n = 1 in the General Formula (A)>

Can be mentioned.
Preferred compounds include compounds of the following structure:

  Further preferred compounds include compounds of the following structure.

  Particularly preferred compounds include compounds of the following structure:

  Most preferred compounds include compounds of the following structure:

There is no limitation on the compounding amount of the compound of the general formula (A) to the whole non-aqueous electrolyte of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired. 0
. 001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, more preferably It is contained at a concentration of 2% by mass or less, particularly preferably 1% by mass or less, most preferably 0.5% by mass or less.

  When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics, and battery swelling are further improved.

1-2. A cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, an acid anhydride compound, an isocyanate compound, a cyclic sulfonic acid ester compound, a compound having an isocyanuric acid skeleton, a nitrile compound In addition to the compound represented by the general formula (A), a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, an acid anhydride compound, an isocyanate compound, a cyclic sulfonic acid ester compound, an isocyanuric acid skeleton It is preferable from the viewpoint of improving the battery characteristics that it further contains at least one compound selected from the group consisting of: nitrile compounds and nitrile compounds; cyclic carbonates having a carbon-carbon unsaturated bond and cyclic carbonates having a fluorine atom are more preferable .

1-2-1. Cyclic carbonate having carbon-carbon unsaturated bond As cyclic carbonate having carbon-carbon unsaturated bond (hereinafter sometimes referred to as "unsaturated cyclic carbonate"), carbon-carbon double bond or carbon-carbon triple bond There is no particular limitation as long as it is a cyclic carbonate having a bond, and any unsaturated carbonate can be used. In addition, the cyclic carbonate which has an aromatic ring shall also be included by unsaturated cyclic carbonate.

  Examples of unsaturated cyclic carbonates include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, And catechol carbonates.

As vinylene carbonates,
Vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate, 4,5-diphenylvinylene carbonate, vinylvinylene carbonate, 4,5-divinylvinylene carbonate, allylvinylene carbonate, 4,5-diallylvinylene carbonate 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate and the like. .

As specific examples of ethylene carbonates substituted by a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond,
Vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5-vinyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5 -Ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl-5-ethynyl ethylene carbonate, phenyl ethylene carbonate, 4,5-diphenyl ethylene carbonate, 4-phenyl-5-vinyl ethylene carbonate, 4-allyl -5-phenyl ethylene carbonate, allyl ethylene carbonate, 4,5-diallyl ethylene carbonate, 4-methyl-5-allyl ethylene carbonate and the like.

Among them, preferred unsaturated cyclic carbonates are
Vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, vinylvinylene carbonate, 4,5-vinylvinylene carbonate, allylvinylene carbonate, 4,5-diallylvinylene carbonate, vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate , 4-methyl-5-vinyl ethylene carbonate, allyl ethylene carbonate, 4,5-diallyl ethylene carbonate, 4-methyl-5-allyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5 -Diethynyl ethylene carbonate, 4-methyl 5- ethynyl ethylene carbonate, 4-vinyl 5- ethynyl ethylene carbonate are mentioned.

In addition, vinylene carbonate, vinyl ethylene carbonate and ethynyl ethylene carbonate are particularly preferable because they form a more stable surface protective film.
The molecular weight of the unsaturated cyclic carbonate is not particularly limited, and is arbitrary unless the effects of the present invention are significantly impaired. The molecular weight is preferably 80 or more and 250 or less. Within this range, the solubility of the unsaturated cyclic carbonate in the non-aqueous electrolytic solution can be easily secured, and the effects of the present invention can be sufficiently exhibited. The molecular weight of the unsaturated cyclic carbonate is more preferably 85 or more, and more preferably 150 or less. The method for producing the unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production.

  The unsaturated cyclic carbonates may be used alone or in any combination of two or more in any proportion. Further, the compounding amount of the unsaturated cyclic carbonate is not particularly limited and is arbitrary unless the effects of the present invention are significantly impaired. However, it is usually 0.001% by mass or more, preferably 0% in 100% by mass of the non-aqueous electrolytic solution. .01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. Within this range, the non-aqueous electrolyte battery is likely to exhibit a sufficient improvement in cycle characteristics, and the high temperature storage characteristics are degraded, the amount of gas generation is increased, and the discharge capacity retention rate is degraded. Easy to avoid.

1-2-2. Cyclic carbonate having a fluorine atom Examples of the cyclic carbonate compound having a fluorine atom include fluorinated compounds of cyclic carbonates having an alkylene group having 2 to 6 carbon atoms, and derivatives thereof. For example, fluorinated compounds of ethylene carbonate and derivatives thereof Can be mentioned. As a derivative of the fluorinated product of ethylene carbonate, for example, fluorinated products of ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms) can be mentioned. Among them, ethylene carbonate having 1 to 8 fluorine atoms and derivatives thereof are preferable.

In particular,
Monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methyl carbonate Ethylene carbonate, 4,4-difluoro-5-methyl ethylene carbonate, 4- (fluoromethyl) -ethylene carbonate, 4- (difluoromethyl) -ethylene carbonate, 4- (trifluoromethyl) -ethylene carbonate, 4- (fluoro) Methyl) -4-fluoroethylene carbonate, 4- (fluoromethyl) -5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene Boneto, 4,4-difluoro-5,5-dimethylethylene carbonate.

Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate and 4,5-difluoroethylene carbonate gives high ion conductivity and preferably forms an interfacial protective film. More preferred.
As the cyclic carbonate compound having a fluorine atom, one type may be used alone, or two or more types may be used in combination in an optional combination and ratio.

  As the cyclic carbonate compound having a fluorine atom, one type may be used alone, or two or more types may be used in combination in an optional combination and ratio. There is no restriction | limiting in the compounding quantity of the halogenated cyclic carbonate with respect to the whole non-aqueous electrolyte solution of this invention, Although it is arbitrary unless the effect of this invention is impaired remarkably, Usually 0.001 mass% in 100 mass% of non-aqueous electrolytes The content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. However, monofluoroethylene carbonate may be used as a solvent, and in that case, it is not limited to the above content.

1-2-3. Acid Anhydride Compound As the acid anhydride compound, carboxylic acid anhydride, sulfuric acid anhydride, nitric acid anhydride, sulfonic acid anhydride, phosphoric acid anhydride, phosphoric acid anhydride, cyclic acid anhydride, chain The structure is not particularly limited as long as it is an acid anhydride compound without limitation such as being an acid anhydride.

As specific examples of the acid anhydride compound, for example,
Malonic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, maleic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride, glutaconic anhydride, itaconic anhydride, phthalic anhydride, phenylmaleic anhydride 2,3-Diphenylmaleic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 4 4,4'-oxydiphthalic anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid anhydride, phenyl succinic acid anhydride, 2-phenyl glutaric acid anhydride , Allylsuccinic anhydride, 2-butene-11-ylsuccinic anhydride, (2-methyl-2-propenyl) succinic anhydride, no tetrafluorosuccinic acid Hydrate, diacetyl-tartaric acid anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, methacrylic acid anhydride, acrylic acid anhydride, crotonic acid anhydride, methanesulfonic acid anhydride, trifluoromethanesulfonic acid anhydride, nonafluorobutane sulfone An acid anhydride, an acetic anhydride, etc. are mentioned.

Of these,
Succinic anhydride, maleic anhydride, citraconic anhydride, phenylmaleic anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2 ,
5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, allylsuccinic acid anhydride, acetic anhydride, methacrylic acid anhydride, acrylic acid anhydride, methanesulfonic acid anhydride Particularly preferred.

An acid anhydride compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no restriction | limiting in the compounding quantity of the acid anhydride compound with respect to the whole non-aqueous electrolyte solution of this invention, Although it is arbitrary unless the effect of this invention is impaired remarkably, Usually 0.001 mass% in 100 mass% of non-aqueous electrolytes Or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, more preferably 1 It is at most mass%, particularly preferably at most 0.5 mass%.

  When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.

1-2-4. Isocyanate Compound The type of the isocyanate compound is not particularly limited as long as it is a compound having an isocyanate group in the molecule.
Specific examples of the isocyanate compound include, for example,
Hydrocarbon-based monoisocyanate compounds such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tertiary butyl isocyanate, pentyl isocyanate, hexyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, fluorophenyl isocyanate and the like;

Monoisocyanate compounds having a carbon-carbon unsaturated bond such as vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, propynyl isocyanate;
Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-diisocyanate Natopropane, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-fluorobutane, 1,4-diisocyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5 -Diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato-3-hexene, 1,6 Diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluorohexane, toluene diisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanato) Methyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1 ′ -Diisocyanate, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane-
4,4'-diisocyanate, bicyclo [2.2.1] heptane-2,5-diyl bis (
Methyl isocyanate), bicyclo [2.2.1] heptane-2,6-diyl bis (methyl isocyanate), isophorone diisocyanate, carbonyl diisocyanate, 1,4-diisocyanatobutane-1,4-dione, 1,5- Hydrocarbon diisocyanate compounds such as diisocyanatopentane-1,5-dione, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate;

Diisocyanato sulfone, isocyanate compounds such as (ortho-, meta-, para-) toluene sulfonyl isocyanate, benzene sulfonyl isocyanate, fluoro sulfonyl isocyanate, phenoxy sulfonyl isocyanate, pentafluoro phenoxy sulfonyl isocyanate, methoxy sulfonyl isocyanate;
Etc.

Among these, monoisocyanate compounds having a carbon-carbon unsaturated bond such as vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, propynyl isocyanate;
Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-bis ( Isocyanatomethyl) cyclohexane, dicyclohexylmethane-4,4'-diisocyanate, bicyclo [2.2.1] heptane-2,
5-diylbis (methyl isocyanate), bicyclo [2.2.1] heptane-2,6-diyl bis (methyl isocyanate), isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4 Hydrocarbon-based diisocyanate compounds such as trimethylhexamethylene diisocyanate;

Diisocyanato sulfone, isocyanate compounds such as (ortho-, meta-, para-) toluene sulfonyl isocyanate, benzene sulfonyl isocyanate, fluoro sulfonyl isocyanate, phenoxy sulfonyl isocyanate, pentafluoro phenoxy sulfonyl isocyanate, methoxy sulfonyl isocyanate;
Is preferable from the point of improvement of cycle characteristics and storage characteristics.

More preferably, allyl isocyanate, hexamethylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, diisocyanato sulfone, (ortho-, meta-, para-) toluene sulfonyl isocyanate is preferred, and particularly preferably hexamethylene Diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, (ortho-, meta-, para-) toluene sulfonyl isocyanate is preferred, and most preferably hexamethylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane preferable.
Moreover, as an isocyanate compound, the isocyanate compound which has a branched chain is preferable.

  The isocyanate compound used in the present invention may be a trimer compound derived from a compound having at least two isocyanate groups in the molecule, or an aliphatic polyisocyanate having a polyhydric alcohol added thereto. For example, biuret represented by basic structures of the following general formulas (3-1) to (3-4), isocyanurate, adduct, modified polyisocyanate of difunctional type and the like can be exemplified (general formula (1-2 -1) to (1-2-4), R and R 'are each independently any hydrocarbon group).

  The compounds having at least two isocyanate groups in the molecule used in the present invention also include so-called blocked isocyanates which are blocked with a blocking agent to improve storage stability. Examples of the blocking agent include alcohols, phenols, organic amines, oximes and lactams. Specifically, n-butanol, phenol, tributylamine, diethylethanolamine, methylethyl ketoxime, ε-caprolactam Etc. can be mentioned.

Metal catalysts such as dibutyltin dilaurate etc., 1,8-diazabicyclo [5.4.0] undecene- for the purpose of promoting reactions based on compounds having at least two isocyanate groups in the molecule and obtaining higher effects. It is also preferable to use an amine catalyst such as 7 in combination.
Furthermore, an isocyanate compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

There is no restriction | limiting in the compounding quantity of the isocyanate compound with respect to the whole non-aqueous electrolyte solution of this invention, Although it is arbitrary unless the effect of this invention is impaired remarkably, Usually 0.001 mass% with respect to the non-aqueous electrolyte of this invention Or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, more preferably 2% by mass In the following, the content is particularly preferably 1% by mass or less, most preferably 0.5% by mass or less.
When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.

1-2-5. Cyclic sulfonic acid ester compound The type of cyclic sulfonic acid ester compound is not particularly limited.
Specific examples of cyclic sulfonic acid esters include, for example,
1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-methyl-1,3-propane sultone , 2-methyl-1,3-propane sultone, 3-methyl-1,3-propane sultone, 1-propene-1,3-sultone, 2-propene-1,3-sultone, 1-fluoro-1-propene 1,3-Sultone, 2-fluoro-1-propene-1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1-fluoro-2-propene-1,3-sultone, 2 -Fluoro-2-propene-1,3-sultone, 3-fluoro-2-propene-1,3-sultone, 1-methyl-1-propene-1,3-sultone, 2-methyl-1-propyl Pen-1,3-sultone, 3-methyl-1-propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-Methyl-2-propene-1,3-sultone, 1,4-butanesultone, 1-fluoro-1,4-butanesultone, 2-fluoro-1,4-butanesultone, 3-fluoro-1,4-butanesultone, 4-fluoro-1,4-butanesultone, 1-methyl-1,4-butanesultone, 2-methyl-1,4-butanesultone, 3-methyl-1,4-butanesultone, 4-methyl-1,4-butanesultone, 1-butene-1,4-sultone, 2-butene-1,4-sultone, 3-butene-1,4-sultone, 1-fluoro-1-butene-1,4-sultone, 2-fluoro 1-butene-1,4-sultone, 3-fluoro-1-butene-1,4-sultone, 4-fluoro-1-butene-1,4-sultone, 1-fluoro-2-butene-1,4- Sultone, 2-fluoro-2-butene-1,4-sultone, 3-fluoro-2-butene-1,4-sultone, 4-fluoro-2-butene-1,4-sultone, 1-fluoro-3- Butene-1,4-sultone, 2-fluoro-3-butene-1,4-sultone, 3-fluoro-3-butene-1,4-sultone, 4-fluoro-3-butene-1,4-sultone, 1-methyl-1-butene-1,4-sultone, 2-methyl-1-butene-1,4-sultone, 3-methyl-1-butene-1,4-sultone, 4-methyl-1-butene- 1,4-sultone, 1-methyl-2-butene-1 4-sultone, 2-methyl-2-butene-1,4-sultone, 3-methyl-2-butene-1,4-sultone, 4-methyl-2-butene-1,4-sultone, 1-methyl- 3-butene-1,4-sultone, 2-methyl-3-butene-1,4-sultone, 3-methyl-3-butene-1,4-sultone, 4-methyl-3-butene-1,4- Sultone, 1,5-pentane sultone, 1-fluoro-1,5-pentane sultone, 2-fluoro-1,5-pentane sultone, 3-fluoro-1,5-pentane sultone, 4-fluoro-1,5-pentane Pentane sultone, 5-fluoro-1,5-pentane sultone, 1-methyl-1,5-pentane sultone, 2-methyl-1,5-pentane sultone, 3-methyl-1,5-pentane sultone, 4-methyl -1,5 -Pentane sultone, 5-methyl-1,5-pentane sultone, 1-pentene-1,5-sultone, 2-pentene-1,5-sultone, 3-pentene-1,5-sultone, 4-pentene-1 5-Sultone, 1-Fluoro-1-pentene-1,5-Sultone, 2-Fluoro-1-pentene-1,5-Sultone, 3-Fluoro-1-pentene-1,5-Sultone, 4-Fluoro -1-pentene-1,5-sultone, 5-fluoro-1-pentene-1,5-sultone, 1-fluoro-2-pentene-1,5-sultone, 2-fluoro-2-pentene-1,5 -Sultone, 3-fluoro-2-pentene-1,5-sultone, 4-fluoro-2-pentene-1,5-sultone, 5-fluoro-2-pentene-1,5-sultone, 1-fluoro-3 -Pe Ten-1,5-sultone, 2-fluoro-3-pentene-1,5-sultone, 3-fluoro-3-pentene-1,5-sultone, 4-fluoro-3-pentene-1,5-sultone, 5-fluoro-3-pentene-1,5-sultone, 1-fluoro-4-pentene-1,5-sultone, 2-fluoro-4-pentene-1,5-sultone, 3-fluoro-4-pentene- 1,5-sultone, 4-fluoro-4-pentene-1,5-sultone, 5-fluoro-4-pentene-1,5-sultone, 1-methyl-1-pentene-1,5-sultone, 2- Methyl-1-pentene-1,5-sultone, 3-methyl-1-pentene-1,5-sultone, 4-methyl-1-pentene-1,5-sultone, 5-methyl-1-pentene-1, 5-Sultone, 1-Me Ru-2-pentene-1,5-sultone, 2-methyl-2-pentene-1,5-sultone, 3-methyl-2-pentene-1,5-sultone, 4-methyl-2-pentene-1, 5-Sultone, 5-methyl-2-pentene-1,5-sultone, 1-methyl-3-pentene-1,5-sultone, 2-methyl-3-pentene-1,5-sultone, 3-methyl- 3-pentene-1,5-sultone, 4-methyl-3-pentene-1,5-sultone, 5-methyl-3-pentene-1,5-sultone, 1-methyl-4-pentene-1,5- Sultone, 2-methyl-4-pentene-1,5-sultone, 3-methyl-4-pentene-1,5-sultone, 4-methyl-4-pentene-1,5-sultone, 5-methyl-4- Sultonization such as pentene-1,5-sultone Compound;

Sulfate compounds such as methylene sulfate, ethylene sulfate and propylene sulfate;
Disulfonate compounds such as methylene methane disulfonate, ethylene methane disulfonate and the like;
1,2,3-oxathiazolidine-2,2-dioxide, 3-methyl-1,2,3-oxathiazolidine-2,2-dioxide, 3H-1,2,3-oxathiazole-2,2-dioxide 5H-1,2,3-oxathiazole-2,2-dioxide, 1,2,4-oxathiazolidine-2,2-dioxide, 4-methyl-1,2,4-oxathiazolidine-2,2- Dioxide, 3H-1,2,4-oxathiazole-2,2-dioxide, 5H-1,2,4-oxathiazole-2,2-dioxide, 1,2,5-oxathiazolidine-2,2-dioxide 5-methyl-1,2,5-oxathiazolidine-2,2-dioxide, 3H-1,2,5-oxathiazole-2,2-dioxide, 5H-1,2,5-oxathiazole-2 2-Dioxide, 1,2,3-oxathiazinane-2,2-dioxide, 3-methyl-1,2,3-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,3-oxathiazine 2,2-dioxide, 1,2,4-oxathiazinane-2,2-dioxide, 4-methyl-1,2,4-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,4- Oxathiazine-2,2-dioxide, 3,6-dihydro-1,2,4-oxathiazine-2,2-dioxide, 3,4-dihydro-1,2,4-oxathiazine-2,2-dioxide, 1, 2,5-oxathiazinane-2,2-dioxide, 5-methyl-1,2,5-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,5-oxathiazine-2 2-dioxide, 3,6-dihydro-1,2,5-oxathiazine-2,2-dioxide, 3,4-dihydro-1,2,5-oxathiazine-2,2-dioxide, 1,2,6- Oxathiazinane-2,2-dioxide, 6-methyl-1,2,6-oxathiadinan-2,2-dioxide, 5,6-dihydro-1,2,6-oxathiazine-2,2-dioxide, 3,4- Nitrogen-containing compounds such as dihydro-1,2,6-oxathiazine-2,2-dioxide and 5,6-dihydro-1,2,6-oxathiazine-2,2-dioxide;

1,2,3-oxathiaphoslane-2,2-dioxide, 3-methyl-1,2,3-oxathiaphoslane-2,2-dioxide, 3-methyl-1,2,3-oxathi Aphoslane-2,2,3-trioxide, 3-methoxy-1,2,3-oxathiaphoslane-2,2,3-trioxide, 1,2,4-oxathiaphoslane-2,2-dioxide , 4-methyl-1,2,4-oxathiaphoslane-2,2-dioxide, 4-methyl-1,2,4-oxathiaphoslane-2,2,4-trioxide, 4-methoxy-1 , 2,4-oxathiaphoslane-2,2,4-trioxide, 1,2,5-oxathiaphoslane-2,2-dioxide, 5-methyl-1,2,5-oxathiaphoslane- 2,2-dioxide, 5-methyl-1,2,5-oxathia Soulan 2,2,5-trioxide, 5-methoxy-1
2,2,5-oxathiaphoslane-2,2,5-trioxide, 1,2,3-oxathiaphosphinan-2,2-dioxide, 3-methyl-1,2,3-oxathiaphosphinan- 2,2-dioxide, 3-methyl-1,2,3-oxathiaphosphinan-2,2,3-trioxide, 3-methoxy-1,2,3-oxathiaphosphinan-2,2,3- Trioxide, 1,2,4-oxathiaphosphinan-2,2-dioxide, 4-methyl-1,2,4-oxathiaphosphinan-2,2-dioxide, 4-methyl-1,2,4- Oxathiaphosphinan-2,2,3-trioxide, 4-methyl-1,5,2,4-dioxathiaphosphinan-2,4-dioxide, 4-methoxy-1,5,2,4-di Oxathiaphosphinan-2,4- Oxide, 3-methoxy-1,2,4-oxathiaphosphinan-2,2,3-trioxide, 1,2,5-oxathiaphosphinan-2,2-dioxide, 5-methyl-1,2,3, 5-oxathiaphosphinan-2,2-dioxide, 5-methyl-1,2,5-oxathiaphosphinan-2,2,3-trioxide, 5-methoxy-1,2,5-oxathiaphosphinan 2,2,3-Trioxide, 1,2,6-oxathiaphosphinan-2,2-dioxide, 6-methyl-1,2,6-oxathiaphosphinan-2,2-dioxide, 6-methyl Phosphorus-containing compounds such as 1,2,6-oxathiaphosphinan-2,2,3-trioxide and 6-methoxy-1,2,6-oxathiaphosphinan-2,2,3-trioxide;

  Among these, 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-propene-1,1, 3-sultone, 1-fluoro-1-propene-1,3-sultone, 2-fluoro-1-propene-1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1,4- Butane sultone, methylene methane disulfonate, ethylene methane disulfonate is preferable from the point of storage characteristic improvement, and 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3 -Fluoro-1,3-propane sultone, 1-propene-1,3-sultone is more preferred.

  The cyclic sulfonic acid ester compounds may be used alone or in any combination and ratio of two or more. There is no restriction | limiting in the compounding quantity of the cyclic sulfonic acid ester compound with respect to the whole non-aqueous electrolyte solution of this invention, Although it is arbitrary unless the effect of this invention is impaired remarkably, Usually 0.001 mass in 100 mass% non-aqueous electrolytes % Or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, particularly preferably It is 2% by mass or less, most preferably 1% by mass or less. When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.

1-2-6. Compound Having an Isocyanuric Acid Backbone The compound having an isocyanuric acid backbone is represented by the general formula (B).

In formula (A), R1 to R3 are each an organic group which may be the same as or different from each other, and may have a substituent having 1 to 20 carbon atoms.
Here, the organic group represents a functional group composed of an atom selected from the group consisting of carbon atom, hydrogen atom, nitrogen atom, oxygen atom and halogen atom. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, a nitrile group, an ether group, a carbonate group, a carbonyl group and the like.

Further, specific examples of the substituent include an alkyl group which may be substituted by a halogen atom, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, a nitrile group, an ether group, a carbonate group, a carbonyl group, a carboxyl group and a sulfonyl And phosphoryl groups and the like.
Specific examples of the alkyl group include, for example, a linear or branched chain such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, tert-butyl group, etc. Examples thereof include an alkyl group or a fluorine-substituted alkyl group, and a cyclic alkyl group such as a cyclopropyl group, a cyclopentyl group and a cyclohexyl group.

Specific examples of the alkenyl group include vinyl group, allyl group, methallyl group, 1-propenyl group, fluorine-substituted vinyl group, allyl group, methallyl group, alkyl group and the like.
Specific examples of the alkynyl group include ethynyl group, propargyl group, 1-propynyl group and the like.
Specific examples of the aryl group include phenyl group, tolyl group, benzyl group, phenethyl group and the like.

Specific examples of the organic group which may have a substituent include an acryl group, a methacryl group, an acryl group via an alkyl group, a methacryl group, an epoxy group, a glycidyl group, a carbonyl group, a cyanoalkyl group, a vinylsulfonyl group, A trimethylsilyl group, a trimethylsilyl group having an alkyl group, and the like can be mentioned.
Among them, methyl, ethyl, i-propyl, tert-butyl, cyclohexyl, vinyl, allyl, methallyl, ethynyl, propargyl, phenyl, acryl, methacryl and alkyl groups are preferable. Acryl, methacryl, glycidyl, carbonyl, cyanoalkyl, vinylsulfonyl, trimethylsilyl, trimethylsilyl having alkyl, fluorine-substituted alkyl, fluorine-substituted vinyl, alkyl, etc. It can be mentioned.

  More preferably, a cyclohexyl group, a vinyl group, an allyl group, a methallyl group, an ethynyl group, a propargyl group, a phenyl group, an acrylic group, an methacrylic group, an acrylic group through an alkyl group, a methacrylic group, a glycidyl group, a cyanoalkyl group, vinyl A sulfonyl group, a trimethylsilyl group, a trimethylsilyl group having an alkyl group, a fluorine-substituted alkyl group, a fluorine-substituted vinyl group, an alkyl group and the like can be mentioned.

  Particularly preferably, a cyclohexyl group, a vinyl group, an allyl group, a methallyl group, an ethynyl group, a propargyl group, an acryl group, a methacryl group, an acryl group via an alkyl group, a methacryl group, a carbonyl group, a vinylsulfonyl group, a trimethylsilyl group, an alkyl The trimethylsilyl group which has group, a fluorine-substituted vinyl group, an alkyl group etc. are mentioned.

Most preferably, a vinyl group, allyl group, methallyl group, ethynyl group, propargyl group, acrylic group through alkyl group, methacryl group, vinylsulfonyl group, glycidyl group, trimethylsilyl group, trimethylsilyl group having alkyl group, fluorine-substituted And vinyl groups and alkyl groups. Among these, groups having a carbon-carbon unsaturated bond are preferable.
As specific examples of the compound, for example,

  Among them, preferably

  More preferably,

  Particularly preferably

  Most preferably,

Can be mentioned.
There is no limitation on the compounding amount of the compound of the general formula (A) to the whole non-aqueous electrolyte of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired. 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less It is preferably contained at a concentration of 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less.

  When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.

1-2-7. Nitrile Compound The nitrile compound is not particularly limited as long as it is a compound having a cyano group in the molecule.
As specific examples of the nitrile compound, for example,
Acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 2-methylbutyronitrile, trimethylacetonitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile , Crotononitrile, 3-methyl crotononitrile, 2-methyl-2-buteneditolyl, 2-pentene nitrile, 2-methyl-2-pentene nitrile, 3-methyl-2-pentene nitrile, 2-hexene nitrile, Fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-diphenyl Oropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3,3'-oxydipropionitrile, 3,3 ' -Compounds having one nitrile group such as thiodipropionitrile, 1,2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile and pentafluoropropionitrile

  Malononitrile, succinonitrile, glutaronitrile, adiponitrile, piperonitrile, suberonitrile, azeronitrile, sebaconitrile, undecane dinitrile, undecane dinitrile, dodecandir nitrile, methyl malononitrile, ethyl malononitrile, isopropyl malononitrile, tert-butyl malononitrile, methyl succinonitrile 2, 2, 2- dimethyl succinonitrile, 2,3- dimethyl succinonitrile, 2, 3, 3- trimethyl succinonitrile, 2, 2, 3, 3- tetramethyl succinonitrile, 2,3- diethyl- 2,3-Dimethylsuccinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-dicarbonitrile, bicyclohexyl-2,2-dicarbonitrile, bicyclohexyl- 2,3-dicarbonitrile, 2,5-dimethyl-2,5-hexanedicarbonitrile, 2,3-diisobutyl-2,3-dimethylsuccinonitrile, 2,2-diisobutyl-3,3-dimethylsuccino Nitrile, 2-methylglutaronitrile, 2,3-dimethylglutaronitrile, 2,4-dimethylglutaronitrile, 2,2,3,3-tetramethylglutaronitrile, 2,2,4,4-tetra Methylglutaronitrile, 2,2,3,4-tetramethylglutaronitrile, 2,3,3,4-tetramethylglutaronitrile, maleonitrile, fumaronitrile, 1,4-dicyanopentane, 2,6-dicyanoheptane 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-dicyanobenzene, 1,3-dicyano Benzene, 1,4-dicyanobenzene, 3,3 '-(ethylenedioxy) dipropionitrile, 3,3'-(ethylenedithio) dipropionitrile, 3,9-bis (2-cyanoethyl) -2,4 , Compounds having two nitrile groups such as 8,10-tetraoxaspiro [5,5] undecane;

  Examples thereof include compounds having three cyano groups such as cyclohexanetricarbonitrile, triscyanoethylamine, triscyanoethoxypropane, tricyanoethylene, pentanetricarbonitrile, propanetricarbonitrile, and heptane tricarbonitrile.

Among these, lauronitrile, crotononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azera nitrile, sebaconitrile, undecane dinitrile, dodecane dinitrile, fumaronitrile, 3,9-bis (2-cyanoethyl)- 2,4,8,10-Tetraoxaspiro [5,5] undecane is preferred from the viewpoint of improving the storage characteristics. In addition, succinonitrile, glutaronitrile, adiponitrile, piperonitrile, suberonitrile, azeronitrile, sebaconitrile, undecane dinitrile, dodecane dinitrile, fumaronitrile, 3,9-bis (2-cyanoethyl) -2,4,8,10-tetra Particularly preferred are dinitrile compounds such as oxaspiro [5,5] undecane.

  A nitrile compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. There is no limitation on the compounding amount of the nitrile compound to the whole non-aqueous electrolyte of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired. The content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass The most preferable amount is 1% by mass or less. When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.

1-3. Electrolyte <lithium salt>
A lithium salt is usually used as the electrolyte. The lithium salt is not particularly limited as long as it is known to be used for this application, and any lithium salt can be used. Specific examples thereof include the following.

For example, inorganic lithium salts such as LiPF 6, LiBF 4, LiClO 4, LiAlF 4, LiSbF 6, LiTaF 6, LiWF 7 and the like;
Lithium tungstates such as LiWOF5;
Lithium salts of carboxylic acids such as HCO 2 Li, CH 3 CO 2 Li, CH 2 F CO 2 Li, CHF 2 CO 2 Li, CF 3 CO 2 Li, CF 3 CH 2 CO 2 Li, CF 3 CF 2 CO 2 Li, CF 3 CF 2 CF 2 CO 2 Li, CF 3 CF 2 CF 2 CF 2 CO 2 Li;
Lithium sulfonate salts such as FSO 3 Li, CH 3 SO 3 Li, CH 2 F SO 3 Li, CHF 2 SO 3 Li, CF 3 SO 3 Li, CF 3 CF 2 SO 3 Li, CF 3 CF 2 CF 2 SO 3 Li, CF 3 CF 2 CF 2 CF 2 CF 2 SO 3 Li;

LiN (FCO) 2, LiN (FCO) (FSO2), LiN (FSO2) 2, LiN (FSO2) (CF3SO2), LiN (CF3SO2) 2, LiN (C2F5SO2) 2, lithium cyclic 1,2-perfluoroethanedi Lithium imide salts such as sulfonyl imide, lithium cyclic 1,3-perfluoropropane disulfonyl imide, LiN (CF 3 SO 2) (C 4 F 9 SO 2), etc.
Lithium methide salts such as LiC (FSO2) 3, LiC (CF3SO2) 3, LiC (C2F5SO2) 3;

Lithium oxalato borate salts such as lithium difluoro oxalato borate, lithium bis (oxalato) borate;
Lithium oxalato phosphate salts such as lithium tetrafluoro oxalato phosphate, lithium difluoro bis (oxalato) phosphate, lithium tris (oxalato) phosphate;

  Besides, LiPF4 (CF3) 2, LiPF4 (C2F5) 2, LiPF4 (CF3SO2) 2, LiPF4 (C2F5SO2) 2, LiBF3CF3, LiBF3C2F5, LiBF3C2F5, LiBF2 (CF3) 2, LiBF2 (C2F5) 2, LiBF2 (CF3 SO2) And fluorine-containing organic lithium salts such as LiBF 2 (C 2 F 5 SO 2) 2 and the like.

Among them, LiPF 6, LiBF 4, LiSbF 6, LiTaF 6, FSO 3 Li, CF
3SO3Li, LiN (FSO2) 2, LiN (FSO2) (CF3SO2), LiN (CF3SO2) 2, LiN (C2F5SO2) 2, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropane Disulfonylimide, LiC (FSO2) 3, LiC (CF3SO2) 3, LiC (C2F5SO2) 3, lithium bisoxalato borate, lithium difluoro oxalato borate, lithium tetrafluoro oxalato phosphate, lithium difluoro bis oxalato phosphate, LiBF 3 CF 3 , LiBF 3 C 2 F 5, LiPF 3 (CF 3) 3, LiPF 3 (C 2 F 5) 3 etc. have the effect of improving output characteristics, high rate charge / discharge characteristics, high temperature storage characteristics, cycle characteristics etc. Masui.

These lithium salts may be used alone or in combination of two or more. One preferable example in the case of using two or more kinds in combination is a combination use of LiPF 6 and LiBF 4, LiPF 6 and LiN (FSO 2) 2, LiPF 6 and FSO 3 Li, etc., and has an effect of improving load characteristics and cycle characteristics.
In this case, the concentration of LiBF 4 or FSO 3 Li with respect to 100% by mass of the whole non-aqueous electrolyte is not limited as long as the effect of the present invention is not significantly impaired. Usually, it is 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30% by mass or less, preferably 20% by mass or less.

  Another example is the combined use of an inorganic lithium salt and an organic lithium salt, and the combined use of both has the effect of suppressing deterioration due to high temperature storage. As an organic lithium salt, CF 3 SO 3 Li, LiN (FSO 2) 2, LiN (FSO 2) (CF 3 SO 2), LiN (CF 3 SO 2) 2, LiN (C 2 F 5 SO 2) 2, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1 , 3-perfluoropropane disulfonyl imide, LiC (FSO 2) 3, LiC (CF 3 SO 2) 3, LiC (C 2 F 5 SO 2) 3, lithium bis oxalato borate, lithium difluoro oxalato borate, lithium tetrafluoro oxalato phosphate, lithium difluoro bis Oxalatophosphate, LiBF 3 CF 3, LiBF 3 C 2 F 5, LiPF 3 (CF 3) 3, LiPF 3 (C 2 F 5) 3 and the like are preferable. In this case, the ratio of the organic lithium salt is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and preferably 30% by mass or less based on 100% by mass of the whole non-aqueous electrolyte solution. And particularly preferably 20% by mass or less.

The concentration of these lithium salts in the non-aqueous electrolytic solution is not particularly limited as long as the effects of the present invention are not impaired, but the electric conductivity of the electrolytic solution is made a good range to ensure good battery performance. In view of the above, the total molar concentration of lithium in the non-aqueous electrolyte solution is preferably 0.3 mol / L or more, more preferably 0.4 mol / L or more, and still more preferably 0.5 mol / L or more. Preferably it is 3 mol / L or less, More preferably, it is 2.5 mol / L or less, More preferably, it is 2.0 mol / L or less.
When the total molar concentration of lithium is in the above range, the conductivity of the electrolytic solution is sufficient, and the decrease in the conductivity due to the increase in viscosity and the decrease in the battery performance due to it are prevented.

1-4. Nonaqueous Solvent There is no particular limitation on the nonaqueous solvent in the present invention, and known organic solvents can be used. When these are illustrated, the cyclic carbonate which does not have a fluorine atom, a linear carbonate, cyclic and linear carboxylic acid ester, an ether compound, a sulfone type compound etc. are mentioned.

<Cyclic carbonate having no fluorine atom>
As a cyclic carbonate which does not have a fluorine atom, the cyclic carbonate which has a C2-C4 alkylene group is mentioned.
As a specific example of the cyclic carbonate which does not have a fluorine atom which has a C2-C4 alkylene group, ethylene carbonate, a propylene carbonate, a butylene carbonate is mentioned. Among them, ethylene carbonate and propylene carbonate are particularly preferable from the viewpoint of the improvement of the battery characteristics derived from the improvement of the lithium ion dissociation degree.

The cyclic carbonates having no fluorine atom may be used alone or in any combination of two or more in any proportion.
The compounding amount of the cyclic carbonate having no fluorine atom is not particularly limited and is optional as long as the effects of the present invention are not significantly impaired. However, the compounding amount when one type is used alone is 100% by volume of non-aqueous solvent Medium, 5% by volume or more, more preferably 10% by volume or more. By setting the range to this range, the decrease of the electric conductivity derived from the decrease of the dielectric constant of the non-aqueous electrolyte solution is avoided, and the large current discharge characteristics of the non-aqueous electrolyte battery, the stability to the negative electrode, and the cycle characteristics are good ranges. It becomes easy to do. Further, it is 95% by volume or less, more preferably 90% by volume or less, and still more preferably 85% by volume or less. By setting the viscosity in this range, the viscosity of the non-aqueous electrolyte solution can be set to an appropriate range, the decrease in ion conductivity can be suppressed, and the load characteristics of the non-aqueous electrolyte battery can be easily set in a good range.

<Linear carbonate>
As a linear carbonate, a C3-C7 linear carbonate is preferable and a C3-C7 dialkyl carbonate is more preferable.
Specific examples of the linear carbonate include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, methyl n-propyl carbonate, n-butyl methyl carbonate, isobutyl methyl carbonate Carbonate, t-butyl methyl carbonate, ethyl-n-propyl carbonate, n-butyl ethyl carbonate, isobutyl ethyl carbonate, t-butyl ethyl carbonate and the like can be mentioned.

Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate and methyl-n-propyl carbonate are preferable, and dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate are particularly preferable. is there.
In addition, linear carbonates having a fluorine atom (hereinafter sometimes referred to as "fluorinated linear carbonate") can also be suitably used.

The number of fluorine atoms contained in the fluorinated linear carbonate is not particularly limited as long as it is 1 or more, but is usually 6 or less, preferably 4 or less. When the fluorinated linear carbonate has a plurality of fluorine atoms, they may be bonded to the same carbon as each other or to different carbons.
The fluorinated linear carbonates include fluorinated dimethyl carbonate and derivatives thereof, fluorinated ethyl methyl carbonate and derivatives thereof, fluorinated diethyl carbonate and derivatives thereof and the like.

Examples of fluorinated dimethyl carbonate and derivatives thereof include fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis (fluoromethyl) carbonate, bis (difluoro) methyl carbonate, bis (trifluoromethyl) carbonate Be
As fluorinated ethyl methyl carbonate and derivatives thereof, 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoro ethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2 -Trifluoroethyl methyl carbonate, 2, 2- difluoro ethyl fluoro methyl carbonate, 2- fluoro ethyl difluoro methyl carbonate, ethyl trifluoromethyl carbonate etc. are mentioned.

  As fluorinated diethyl carbonate and derivatives thereof, ethyl- (2-fluoroethyl) carbonate, ethyl- (2,2-difluoroethyl) carbonate, bis (2-fluoroethyl) carbonate, ethyl- (2,2,2-) Trifluoroethyl) carbonate, 2,2-difluoroethyl-2'-fluoroethyl carbonate, bis (2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2'-fluoroethyl carbonate, 2, 2,2-trifluoroethyl-2 ', 2'-difluoroethyl carbonate, bis (2,2,2-trifluoroethyl) carbonate, etc. are mentioned.

As the chain carbonate, one type may be used alone, or two or more types may be used in combination in an optional combination and ratio.
The compounding amount of the linear carbonate is preferably 5% by volume or more, more preferably 10% by volume or more, and still more preferably 15% by volume or more in 100% by volume of the non-aqueous solvent. By setting the lower limit in this manner, the viscosity of the non-aqueous electrolyte solution can be set to an appropriate range, the decrease in ion conductivity can be suppressed, and the large current discharge characteristics of the non-aqueous electrolyte battery can be easily set to a good range. The linear carbonate is preferably 90% by volume or less, more preferably 85% by volume or less, and particularly preferably 80% by volume or less in 100% by volume of the non-aqueous solvent. By setting the upper limit in this manner, it is possible to avoid the decrease in the electrical conductivity resulting from the decrease in the dielectric constant of the non-aqueous electrolyte solution, and to easily set the large current discharge characteristics of the non-aqueous electrolyte battery in a good range.

<Cyclic carboxylic acid ester>
The cyclic carboxylic acid ester is preferably one having 3 to 12 carbon atoms.
Specifically, gamma butyrolactone, gamma valerolactone, gamma caprolactone, epsilon caprolactone and the like can be mentioned. Among them, gamma-butyrolactone is particularly preferable from the viewpoint of the improvement of the battery characteristics derived from the improvement of the lithium ion dissociation degree.

The cyclic carboxylic acid esters may be used alone or in any combination of two or more in any proportion.
The compounding amount of the cyclic carboxylic acid ester is usually 5% by volume or more, more preferably 10% by volume or more in 100% by volume of the non-aqueous solvent. Within this range, the electrical conductivity of the non-aqueous electrolyte solution is improved, and the large current discharge characteristics of the non-aqueous electrolyte battery can be easily improved. Moreover, the compounding quantity of cyclic carboxylic acid ester becomes like this. Preferably it is 50 volume% or less, More preferably, it is 40 volume% or less. By setting the upper limit in this way, the viscosity of the non-aqueous electrolyte solution is made into an appropriate range, the decrease in electrical conductivity is avoided, the increase in negative electrode resistance is suppressed, and the large current discharge of non-aqueous electrolyte secondary battery It becomes easy to make a characteristic into a good range.

<Linear carboxylic acid ester>
The chain carboxylic acid ester is preferably one having 3 to 7 carbon atoms. Specifically, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, Isopropyl propionate, n-butyl propionate, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyrate-n- Propyl, isopropyl isobutyrate and the like can be mentioned.

Among them, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, methyl butyrate, ethyl butyrate, etc. are due to viscosity reduction. It is preferable from the point of the improvement of ion conductivity.
As the chain carboxylic acid ester, one type may be used alone, or two or more types may be used in combination in an optional combination and ratio.

  The blending amount of the linear carboxylic acid ester is usually 10% by volume or more, preferably 15% by volume or more, in 100% by volume of the non-aqueous solvent. By setting the lower limit in this manner, the electrical conductivity of the non-aqueous electrolyte solution can be improved, and the large current discharge characteristics of the non-aqueous electrolyte battery can be easily improved. Moreover, the compounding quantity of chain | strand-shaped carboxylic acid ester is preferably 60 volume% or less, more preferably 50 volume% or less in 100 volume% of non-aqueous solvents. By setting the upper limit in this manner, an increase in negative electrode resistance can be suppressed, and the large current discharge characteristics and the cycle characteristics of the non-aqueous electrolyte battery can be easily made into a good range.

<Ether compounds>
As the ether compound, a chain ether having 3 to 10 carbon atoms and a cyclic ether having 3 to 6 carbon atoms in which part of hydrogen may be substituted with fluorine are preferable.
As a C3-C10 linear ether,
Diethyl ether, di (2-fluoroethyl) ether, di (2,2-difluoroethyl) ether, di (2,2,2-trifluoroethyl) ether, ethyl (2-fluoroethyl) ether, ethyl (2,2, 2,2-Trifluoroethyl) ether, ethyl (1,1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl) (2,2,2-trifluoroethyl) ether, (2-fluoroethyl) ) (1,1,2,2-tetrafluoroethyl) ether, (2,2,2-trifluoroethyl) (1,1,2,2-tetrafluoroethyl) ether, ethyl-n-propylether, ethyl (3-fluoro-n-propyl) ether, ethyl (3,3,3-trifluoro-n-propyl) ether, ethyl (2,2,3,3-tet) Fluoro-n-propyl) ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl) ether, 2-fluoroethyl-n-propylether, (2-fluoroethyl) (3-fluoro- n-Propyl) ether, (2-fluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (2-fluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) Ether, (2-fluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 2,2,2-trifluoroethyl-n-propylether, (2,2,2- Trifluoroethyl) (3-fluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (2,2,3 , 2-Trifluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (2,2,3,3,3-pentafluoro- n-Propyl) ether, 1,1,2,2-tetrafluoroethyl-n-propylether, (1,1,2,2-tetrafluoroethyl) (3-fluoro-n-propyl) ether, (1,1 1,2,2-tetrafluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3-tetrafluoro -N-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-propylether, (n- Propyl) (3-fluo Ro-n-propyl) ether, (n-propyl) (3,3,3-trifluoro-n-propyl) ether, (n-propyl) (2,2,3,3-tetrafluoro-n-propyl) Ether, (n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (3-fluoro-n-propyl) ether, (3-fluoro-n-propyl) (3) , 3,3-Trifluoro-n-propyl) ether, (3-fluoro-n-propyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (3-fluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (3,3,3-trifluoro-n-propyl) ether, (3,3,3-trifluoro-n-propyl) ) (2, 2, 3, 3- Tiger fluoro -n- propyl) ether, (3,3,3
-Trifluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,3 2,3,3-Tetrafluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (2,2,3,3,3-pentafluoro-n-) Propyl) ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, methoxy (2-fluoroethoxy) methane, methoxy (2,2,2-trifluoroethoxy) methanemethoxy (1,1,2,2-tetra) Fluoroethoxy) methane, diethoxymethane, ethoxy (2-fluoroethoxy) methane, ethoxy (2,2,2-trifluoroethoxy) methane, ethoxy (1,1 2,2-tetrafluoroethoxy) methane, di (2-fluoroethoxy) methane, (2-fluoroethoxy) (2,2,2-trifluoroethoxy) methane, (2-fluoroethoxy) (1,1 and 2) 2,2-tetrafluoroethoxy) methanedi (2,2,2-trifluoroethoxy) methane, (2,2,2-trifluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methane, di (1 (1,2,2-tetrafluoroethoxy) methane, dimethoxyethane, methoxyethoxyethane, methoxy (2-fluoroethoxy) ethane, methoxy (2,2,2-trifluoroethoxy) ethane, methoxy (1,1,2 , 2-Tetrafluoroethoxy) ethane, diethoxyethane, ethoxy (2-fluoroethoxy) ethane, ethoxy (2,2 2-trifluoroethoxy) ethane, ethoxy (1,1,2,2-tetrafluoroethoxy) ethane, di (2-fluoroethoxy) ethane, (2-fluoroethoxy) (2,2,2-trifluoroethoxy) Ethane, (2-fluoroethoxy) (1,1,2,2-tetrafluoroethoxy) ethane, di (2,2,2-trifluoroethoxy) ethane, (2,2,2-trifluoroethoxy) (1 1,2,2,2-tetrafluoroethoxy) ethane, di (1,1,2,2-tetrafluoroethoxy) ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether etc. It can be mentioned.

The cyclic ether having 3 to 6 carbon atoms includes tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1 And 4-dioxane etc., and fluorinated compounds thereof.
Among them, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether have high solvation ability to lithium ions and improve ion dissociation. From the viewpoint of low viscosity and high ionic conductivity, dimethoxymethane, diethoxymethane and ethoxymethoxymethane are particularly preferable.

The ether compounds may be used alone or in any combination of two or more in any proportion.
The compounding amount of the ether compound is usually 5% by volume or more, preferably 10% by volume or more, more preferably 15% by volume or more, and preferably 70% by volume or less in 100% by volume of the nonaqueous solvent More preferably, it is 60 volume% or less, more preferably 50 volume% or less.

Within this range, the effect of improving the lithium ion dissociation degree of the chain ether and the improvement of the ion conductivity derived from the viscosity decrease can be easily secured, and when the negative electrode active material is a carbonaceous material, the chain ether together with the lithium ion It is easy to avoid the situation that the capacity is reduced due to the co-insertion.
<Sulphone type compounds>
As a sulfone type compound, a C3-C6 cyclic sulfone and a C2-C6 chain-like sulfone are preferable. The number of sulfonyl groups in one molecule is preferably 1 or 2.

As a C3-C6 cyclic sulfone,
Monosulfone compounds trimethylene sulfones, tetramethylene sulfones, hexamethylene sulfones;
Examples of such a disulfone compound include trimethylene disulfones, tetramethylene disulfones, and hexamethylene disulfones.

Among them, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones and hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable, from the viewpoint of dielectric constant and viscosity.
As sulfolanes, sulfolane and / or sulfolane derivatives (hereinafter sometimes referred to as “sulfolanes including sulfolane”) are preferable. As the sulfolane derivative, one in which at least one hydrogen atom bonded to a carbon atom constituting a sulfolane ring is substituted with a fluorine atom or an alkyl group is preferable.

  Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-Difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3-methylsulfolane Sulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoro Methyl sulfolane, 2- Trifluoromethyl sulfolane, 3-trifluoromethyl sulfolane, 2-fluoro-3- (trifluoromethyl) sulfolane, 3-fluoro-3- (trifluoromethyl) sulfolane, 4-fluoro-3- (trifluoromethyl) sulfolane 5-fluoro-3- (trifluoromethyl) sulfolane and the like are preferable in that they have high ion conductivity and high input / output characteristics.

Moreover, as a C2-C6 linear sulfone,
Dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, n-butyl methyl sulfone, n-butyl ethyl Sulfone, t-butyl methyl sulfone, t-butyl ethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoro Ethyl methyl sulfone, Ethyl mono fluoro methyl sulfone, Ethyl difluoro methyl sulfone, Ethyl trifluoromethyl sulfone, Perf Oroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (trifluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl- n-propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl n-propyl sulfone, pentafluoroethyl isopropyl sulfone Trifluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl- - butyl sulfone, pentafluoroethyl -t- butyl sulfone, and the like.

Among them, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone Monofluoroethyl methyl sulfone difluoroethyl methyl sulfone trifluoroethyl methyl sulfone pentafluoroethyl methyl sulfone ethyl monofluoromethyl sulfone ethyl difluoromethyl sulfone ethyl trifluoromethyl sulfone ethyl trifluoroethyl sulfone ethyl pentafluoro Ethyl sulfone, trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, tri Ruoroechiru -n- butyl sulfone, trifluoroethyl -t- butyl sulfone, trifluoromethyl -n- butyl sulfone, trifluoromethyl -t- butyl sulfone is high ion conductivity, preferable because the input-output characteristic is high.

The sulfone-based compounds may be used alone or in any combination of two or more in any proportion.
The blending amount of the sulfone-based compound is usually preferably at least 0.3 vol. It is at most volume%, more preferably at most 35 volume%, even more preferably at most 30 volume%.

  Within this range, the effect of improving the durability such as cycle characteristics and storage characteristics can be easily obtained, and the viscosity of the non-aqueous electrolyte can be made an appropriate range, and a decrease in electrical conductivity can be avoided. When the charge and discharge of the water-based electrolyte battery are performed at a high current density, it is easy to avoid the situation where the charge and discharge capacity retention rate decreases.

<When using a cyclic carbonate having a fluorine atom as a non-aqueous solvent>
In the present invention, when a cyclic carbonate having a fluorine atom is used as a nonaqueous solvent, one of the non-aqueous solvents exemplified above is combined with the cyclic carbonate having a fluorine atom as a nonaqueous solvent other than the cyclic carbonate having a fluorine atom. These may be used or two or more may be used in combination with the cyclic carbonate having a fluorine atom.

  For example, one preferable combination of non-aqueous solvents is a combination mainly composed of a cyclic carbonate having a fluorine atom and a linear carbonate. Among them, the total of the cyclic carbonate having a fluorine atom and the chain carbonate in the non-aqueous solvent is preferably 60% by volume or more, more preferably 80% by volume or more, and still more preferably 90% by volume or more. The ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a and the linear carbonate is 3% by volume or more, preferably 5% by volume or more, more preferably 10% by volume or more, and still more preferably 15% by volume or more Also, it is usually 60% by volume or less, preferably 50% by volume or less, more preferably 40% by volume or less, more preferably 35% by volume or less, particularly preferably 30% by volume or less, and most preferably 20% by volume or less.

When a combination of these non-aqueous solvents is used, the balance between the cycle characteristics and the high temperature storage characteristics (in particular, the residual capacity after high temperature storage and the high load discharge capacity) of a battery manufactured using the combination may be improved.
For example, as a specific example of a preferable combination of cyclic carbonate having a fluorine atom and linear carbonate,
Monofluoroethylene carbonate and dimethyl carbonate, Monofluoroethylene carbonate and diethyl carbonate, Monofluoroethylene carbonate and ethyl methyl carbonate, Monofluoroethylene carbonate and dimethyl carbonate and diethyl carbonate, Monofluoroethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, Monofluoroethylene carbonate and dimethyl carbonate Examples thereof include ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

  Among combinations of cyclic carbonates having a fluorine atom and linear carbonates, those containing symmetrical linear alkyl carbonates as linear carbonates are more preferable, and in particular, monofluoroethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, mono Those containing monofluoroethylene carbonate such as fluoroethylene carbonate and diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and dimethyl carbonate and diethyl carbonate and diethyl carbonate and ethyl methyl carbonate, symmetrical linear carbonates and asymmetric linear carbonates, cycle characteristics It is preferable because the balance between the high current discharge characteristics and the high current discharge characteristics is good. Among them, the symmetrical linear carbonates are preferably dimethyl carbonate, and the alkyl group of the linear carbonate preferably has 1 to 2 carbon atoms.

  The combination which added the cyclic carbonate which does not have a fluorine atom further to the combination of the cyclic carbonate which has these fluorine atoms, and linear carbonates is also mentioned as a preferable combination. Among them, the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom in the non-aqueous solvent is preferably 10% by volume or more, more preferably 15% by volume or more, still more preferably 20% by volume or more The ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom is 1% by volume or more, preferably 3% by volume or more, more preferably 5% by volume or more , More preferably 10% by volume or more, particularly preferably 20% by volume or more, preferably 95% by volume or less, more preferably 85% by volume or less, still more preferably 75% by volume or less, particularly preferably 60% by volume It is the following.

When the cyclic carbonate having no fluorine atom is contained in this concentration range, the electric conductivity of the electrolytic solution can be maintained while forming a stable protective film on the negative electrode.
Specific examples of preferable combinations of cyclic carbonates having a fluorine atom, cyclic carbonates having no fluorine atom, and linear carbonates are as follows:
Monofluoroethylene carbonate and ethylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and ethylene carbonate and diethyl carbonate, monofluoroethylene carbonate and ethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and ethylene carbonate and dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate Ethylene carbonate, ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl carbonate Monofluoroethylene carbonate and propylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and propylene carbonate and diethyl carbonate, monofluoroethylene carbonate and propylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate and dimethyl carbonate and diethyl carbonate, Monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate Ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate and dimethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate and diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate Carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate and propylene carbonate, Examples include diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

Among the combinations of cyclic carbonates having a fluorine atom, cyclic carbonates having no fluorine atom, and linear carbonates, those containing asymmetric linear alkyl carbonates as linear carbonates are more preferable, in particular,
Monofluoroethylene carbonate and ethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and ethylene carbonate and ethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate and dimethyl carbonate Ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate Ethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate Containing monofluoroethylene carbonate and asymmetric linear carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, ethylene carbonate, propylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate Since the balance of Le characteristics and large-current discharge characteristics may preferably. Among them, the asymmetric linear carbonates are preferably ethyl methyl carbonate, and the alkyl group of the linear carbonate preferably has 1 to 2 carbon atoms.

  When ethyl methyl carbonate is contained in the non-aqueous solvent, the proportion of ethyl methyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, still more preferably 25% by volume or more Particularly preferably 30% by volume or more, preferably 95% by volume or less, more preferably 90% by volume or less, still more preferably 85% by volume or less, particularly preferably 80% by volume or less The load characteristics of the battery may be improved.

  In the combination mainly composed of the cyclic carbonate having a fluorine atom and the chain carbonate, in addition to the cyclic carbonate having no fluorine atom, cyclic carboxylic acid esters, linear carboxylic acid esters, cyclic ethers, chain Other solvents such as organic ethers, sulfur-containing organic solvents, phosphorus-containing organic solvents, and fluorine-containing aromatic solvents may be mixed.

<When using a cyclic carbonate having a fluorine atom as an auxiliary agent>
In the present invention, when using a cyclic carbonate having a fluorine atom as an auxiliary, one of the non-aqueous solvents exemplified above may be used alone as a non-aqueous solvent other than the cyclic carbonate having a fluorine atom, or two or more May be used in any combination and ratio.

For example, one preferable combination of non-aqueous solvents is a combination mainly composed of a cyclic carbonate having no fluorine atom and a linear carbonate.
Among them, the total of the cyclic carbonate having no fluorine atom in the non-aqueous solvent and the linear carbonate is preferably 70% by volume or more, more preferably 80% by volume or more, still more preferably 90% by volume or more The ratio of the cyclic carbonate having no fluorine atom to the total of the cyclic carbonate and the chain carbonate is preferably 5% by volume or more, more preferably 10% by volume or more, still more preferably 15% by volume or more, and preferably It is 50% by volume or less, more preferably 35% by volume or less, still more preferably 30% by volume or less, and particularly preferably 25% by volume or less.

When a combination of these non-aqueous solvents is used, the balance between the cycle characteristics and the high temperature storage characteristics (in particular, the residual capacity after high temperature storage and the high load discharge capacity) of a battery manufactured using the combination may be improved.
For example, as a specific example of a preferable combination of cyclic carbonate and linear carbonate having no fluorine atom,
Ethylene carbonate and dimethyl carbonate, Ethylene carbonate and diethyl carbonate, Ethylene carbonate and ethyl methyl carbonate, Ethylene carbonate and dimethyl carbonate and diethyl carbonate, Ethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, Ethylene carbonate and diethyl carbonate and ethyl methyl carbonate, Ethylene carbonate And dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, propylene carbonate and ethyl methyl carbonate, propylene carbonate and ethyl methyl carbonate and diethyl carbonate, propylene carbonate, ethyl methyl carbonate and dimethyl carbonate, and the like.

  Among the combinations of cyclic carbonates having no fluorine atom and linear carbonates, those containing asymmetric linear alkyl carbonates as linear carbonates are more preferable, and in particular, ethylene carbonate and ethyl methyl carbonate, propylene carbonate and ethyl Methyl carbonate, ethylene carbonate and ethyl methyl carbonate and dimethyl carbonate, ethylene carbonate and ethyl methyl carbonate and diethyl carbonate, propylene carbonate and ethyl methyl carbonate and dimethyl carbonate, propylene carbonate and ethyl methyl carbonate and diethyl carbonate, etc. have cycle characteristics and large currents It is preferable because the balance of the discharge characteristics is good.

Among them, the asymmetric linear carbonates are preferably ethyl methyl carbonate, and the alkyl group of the linear carbonate preferably has 1 to 2 carbon atoms.
When dimethyl carbonate is contained in the non-aqueous solvent, the proportion of dimethyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, still more preferably 25% by volume or more, particularly Preferably, it is 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, still more preferably 75% by volume or less, and particularly preferably 70% by volume or less. Battery load characteristics may improve.

Among them, by containing dimethyl carbonate and ethyl methyl carbonate, by making the content ratio of dimethyl carbonate more than the content ratio of ethyl methyl carbonate, the battery characteristics after high temperature storage can be improved while maintaining the electric conductivity of the electrolytic solution It is preferable to do it.
The volume ratio of dimethyl carbonate to ethyl methyl carbonate in the total non-aqueous solvent (dimethyl carbonate / ethyl methyl carbonate) is 1.1 or more in that it improves the electric conductivity of the electrolytic solution and the battery characteristics after storage. Is preferably 1.5 or more, more preferably 2.5 or more. The volume ratio (dimethyl carbonate / ethyl methyl carbonate) is preferably 40 or less, more preferably 20 or less, still more preferably 10 or less, and particularly preferably 8 or less, from the viewpoint of improving the battery characteristics at low temperatures.

In the combination mainly composed of the cyclic carbonate having no fluorine atom and the linear carbonate, cyclic carboxylic acid esters, linear carboxylic acid esters, cyclic ethers, linear ethers, sulfur-containing organic solvent, phosphorus-containing organic solvent Other solvents such as an organic solvent and an aromatic fluorine-containing solvent may be mixed.
In addition, in this specification, although the volume of a non-aqueous solvent is a measured value at 25 degreeC, what is a solid at 25 degreeC like ethylene carbonate uses the measured value in melting | fusing point.

1-5. Auxiliary Agent In the non-aqueous electrolytic solution battery of the present invention, an auxiliary agent may be suitably used according to the purpose, in addition to the above-described substances. Examples of the auxiliary include aromatic compounds having 12 or less carbon atoms, fluorinated unsaturated cyclic carbonate, compounds having a triple bond, and other auxiliary agents, which are shown below.
1-5-1. Aromatic Compounds having 12 or Less Carbons As the aromatic compounds having 12 or less carbon atoms, the type thereof is not particularly limited as long as the number of carbon atoms in the molecule is 12 or less.

As a specific example of the aromatic compound of carbon nest 12 or less, for example,
Aromatic compounds such as biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, etc .; Partially fluorinated;
And fluorine-containing anisole compounds such as 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6-difluoroanisole, 3,5-difluoroanisole and the like. Above all,
Aromatic compounds such as biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether and dibenzofuran are preferred.

  These may be used alone or in combination of two or more. When two or more are used in combination, in particular, a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, an oxygen-free aroma such as biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, etc. It is preferable from the viewpoint of the balance of high-temperature storage characteristics that a combination of at least one selected from group compounds and at least one selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran is used.

  The aromatic compound having 12 or less carbon atoms is not particularly limited, and is optional unless the effects of the present invention are significantly impaired. The overcharge inhibitor is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less in 100% by mass of the non-aqueous electrolytic solution. It is preferably contained at a concentration of 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, particularly preferably 1% by mass or less. Within this range, the effect of the overcharge preventing agent can be easily exhibited sufficiently, and the situation in which the battery characteristics such as the high temperature storage characteristics are degraded can be easily avoided.

1-5-2. Fluorinated unsaturated cyclic carbonate As the fluorinated cyclic carbonate, it is also preferable to use a cyclic carbonate having an unsaturated bond and a fluorine atom (hereinafter sometimes referred to as "fluorinated unsaturated cyclic carbonate"). The number of fluorine atoms in the fluorinated unsaturated cyclic carbonate is not particularly limited as long as it is 1 or more. Among them, the number of fluorine atoms is usually 6 or less, preferably 4 or less, and most preferably 1 or 2.

Examples of the fluorinated unsaturated cyclic carbonate include fluorinated vinylene carbonate derivatives, fluorinated ethylene carbonate derivatives substituted with a substituent having an aromatic ring or a carbon-carbon double bond, and the like.
As fluorinated vinylene carbonate derivatives, 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, 4-fluoro-5-fluorovinylene carbonate And vinyl vinylene carbonate and the like.

As a fluorinated ethylene carbonate derivative substituted by a substituent having an aromatic ring or a carbon-carbon double bond,
4-fluoro-4-vinyl ethylene carbonate, 4-fluoro-4-allyl ethylene carbonate, 4-fluoro-5-vinyl ethylene carbonate, 4-fluoro-5-allyl ethylene carbonate, 4,4-difluoro-4-vinyl ethylene Carbonate, 4,4-difluoro-4-allyl ethylene carbonate, 4,5-difluoro-4-vinyl ethylene carbonate, 4,5-difluoro-4-allyl ethylene carbonate, 4-fluoro-4,5-divinyl ethylene carbonate, 4-fluoro-4,5-diallyl ethylene carbonate, 4,5-difluoro-4,5-divinyl ethylene carbonate, 4,5-difluoro-4,5-diallyl ethylene carbonate, 4-fluoro-4-phenyl ethylene carbonate, 4-f Oro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate.

Among them, preferred fluorinated unsaturated cyclic carbonates are
4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, 4-fluoro-4-vinylethylene carbonate, 4-fluoro- 4-allyl ethylene carbonate, 4-fluoro-5-vinyl ethylene carbonate, 4-fluoro-5-allyl ethylene carbonate, 4,4-difluoro-4-vinyl ethylene carbonate, 4,4-difluoro-4-allyl ethylene carbonate, 4,5-Difluoro-4-vinyl ethylene carbonate, 4,5-Difluoro-4-allyl ethylene carbonate, 4-fluoro-4,5-divinyl ethylene carbonate, 4-fluoro-4,5-diallyl ethylene carbonate 4,5-difluoro-4,5-divinyl ethylene carbonate, 4,5-difluoro-4,5-diallyl ethylene carbonate, because it forms a stable interface protective coating, more preferably used.

The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary unless the effects of the present invention are significantly impaired. The molecular weight is preferably 50 or more and 250 or less. Within this range, the solubility of the fluorinated cyclic carbonate in the non-aqueous electrolyte solution can be easily ensured, and the effects of the present invention can be easily exhibited.
The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production. The molecular weight is more preferably 100 or more, and more preferably 200 or less.

The fluorinated unsaturated cyclic carbonates may be used alone or in any combination of two or more in any proportion. In addition, the blending amount of the fluorinated unsaturated cyclic carbonate is not particularly limited, and is arbitrary unless the effects of the present invention are significantly impaired.
The compounding amount of the fluorinated unsaturated cyclic carbonate is usually 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more in 100% by mass of the non-aqueous electrolytic solution. And preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, and particularly preferably 2% by mass or less.

Within this range, the non-aqueous electrolyte battery is likely to exhibit a sufficient improvement in cycle characteristics, and the high temperature storage characteristics are degraded, so that the amount of gas generation increases and the discharge capacity retention rate is degraded. Easy to avoid.
1-5-3. Compound Having Triple Bond The compound having a triple bond is not particularly limited as long as it is a compound having one or more triple bonds in the molecule.

Specific examples of the compound having a triple bond include, for example, the following compounds.
1-Pentin, 2-Pentin, 1-Hexin, 2-Hexin, 3-Hexin, 1-Heptin, 2-Heptin, 3-Heptin, 1-Octin, 2-Octin, 3-Octin, 4-Octin, 1-Hoctin Nonin, 2-nonin, 3-nonin, 4-nonin, 1-dodecin, 2-dodecin, 3-dodecin, 4-dodecin, 5-dodecin, phenylacetylene, 1-phenyl-1-propyne, 1-phenyl-2 -Propine, 1-phenyl-1-butyne, 4-phenyl-1-butyne, 4-phenyl-1-butyne, 1-phenyl-1-pentyne, 5-phenyl-1-pentyne, 1-phenyl-1-hexyne And hydrocarbon compounds such as 6-phenyl-1-hexyne, diphenylacetylene, 4-ethynyltoluene, dicyclohexylacetylene and the like;

2-propynyl methyl carbonate, 2-propynyl ethyl carbonate, 2-propynyl propyl carbonate, 2-propynyl butyl carbonate, 2-propynyl phenyl carbonate, 2-propynyl cyclohexyl carbonate, di-2-propynyl carbonate, 1-methyl-2-propynyl Methyl carbonate, 1,1-dimethyl-2-propynyl methyl carbonate, 2-butynyl methyl carbonate, 3-butynyl methyl carbonate, 2-pentynyl methyl carbonate, 3-pentynyl methyl carbonate, 4-pentynyl methyl carbonate, Etc. monocarbonates;
2-butyne-1,4-diol dimethyl dicarbonate, 2-butyne-1,4-diol diethyl dicarbonate, 2-butyne-1,4-diol dipropyl dicarbonate, 2-butyne-1,4-diol dibutyl Dicarbonates such as dicarbonate, 2-butyne-1,4-diol diphenyldicarbonate, 2-butyne-1,4-diol dicyclohexyldicarbonate;

2-propynyl acetate, 2-propynyl propionate, 2-propynyl butyrate, 2-propynyl benzoate, 2-propynyl cyclohexylcarboxylate, 1,1-dimethyl-2-propynyl acetate, 1,1-dimethyl-2-propionic acid Propynyl, butyric acid 1,1-dimethyl-2-propynyl, benzoic acid 1,1-dimethyl-2-propynyl, cyclohexylcarboxylic acid 1, 1-dimethyl-2-propynyl acetate, 2-butynyl acetate, 3-butynyl acetate, acetic acid 2 -Pentynyl, 3-pentynyl acetate, 4-pentynyl acetate, methyl acrylate, ethyl acrylate, propyl acrylate, vinyl acrylate, 2-propenyl acrylate, 2-butenyl acrylate, 3-butenyl acrylate, methyl methacrylate , Ethyl Methacrylate, Propyl Methacrylate, Methac Vinyl lactate, 2-propenyl methacrylate, 2-butenyl methacrylate, 3-butenyl methacrylate, methyl 2-propynoate, ethyl 2-propynoate, propyl 2-propynoate, vinyl 2-propynoate, 2-propynoic acid 2-propenyl, 2-propynoate 2-butenyl, 2-propynoate 3-butenyl, methyl 2-butyrate, ethyl 2-butyrate, propyl 2-butyrate, vinyl 2-butyrate, 2-butynoate Propenyl, 2-butenyl 2-butyrate, 3-butenyl 2-butyrate, methyl 3-butyrate, ethyl 3-butyrate, propyl 3-butynoate, vinyl 3-butyrate, 2-propenyl 3-butynate, 3-butyric acid 2-butenyl, 3-butynyl 3-butenyl, methyl 2-pentynoate, ethyl 2-pentynoate, propyl 2-pentynoate, 2- Vinyl benzoate, 2-propenyl 2-pentyrate, 2-butenyl 2-pentyrate, 3-butenyl 2-pentyrate, methyl 3-pentyrate, ethyl 3-pentyrate, propyl 3-pentynoate, 3-pentynoate Vinyl, 2-propenyl 3-pentyrate, 2-butenyl 3-pentyrate, 3-butenyl 3-pentyrate, methyl 4-pentyrate, ethyl 4-pentyrate, propyl 4-pentyrate, vinyl 4-pentynoate, Monocarboxylic acid esters such as 2-pentenyl 4-pentynoate, 2-butenyl 4-pentynoate, 3-butenyl 4-pentynoate;
2-butyne-1,4-diol diacetate, 2-butyne-1,4-diol dipropionate, 2-butyne-1,4-diol dibutyrate, 2-butyne-1,4-diol dibenzoate, 2-butyne -Dicarboxylic acid esters such as 1,4-diol dicyclohexane carboxylate;

  Methyl oxalate 2-propynyl, ethyl oxalate 2-propynyl, propyl oxalate 2-propynyl, oxalate 2-propynyl vinyl, allyl oxalate 2-propynyl oxalate, di-2-propynyl oxalate, 2-butynyl methyl oxalate, Ethyl 2-butynyl oxalate, 2-butynyl propyl oxalate, vinyl 2-butynyl oxalate, allyl 2-butynyl oxalate, di-2-butynyl oxalate, 3-butynyl oxalate, 3-butynyl ethyl oxalate , 3-butynylpropyl oxalate, 3-butynyl oxalate

Oxalate diesters such as vinyl, allyl 3-butynyl oxalate, di-3-butynyl oxalate;
Methyl (2-propynyl) (vinyl) phosphine oxide, divinyl (2- propynyl) phosphine oxide, di (2- propynyl) (vinyl) phosphine oxide, di (2- propenyl) 2 (-propynyl) phosphine oxide, di (2 Phosphine oxides such as propynyl) (2-propenyl) phosphine oxide, di (3-butenyl) (2-propynyl) phosphine oxide, and di (2-propynyl) (3-butenyl) phosphine oxide;

  2-propynyl methyl (2-propenyl) phosphinate, 2-propynyl 2-butenyl (methyl) phosphinate, 2-propynyl di (2-propenyl) phosphinate, 2-propynyl di (3-butenyl) phosphinate, methyl 2-propenyl) phosphinic acid 1,1-dimethyl-2-propynyl, 2-butenyl (methyl) phosphinic acid 1,1-dimethyl-2-propynyl, di (2-propenyl) phosphinic acid 1,1-dimethyl-2- Propynyl and 1,1-dimethyl-2-propynyl di (3-butenyl) phosphinic acid, 2-propenyl methyl (2-propynyl) phosphinic acid, 3-butenyl methyl (2-propynyl) phosphinate, di (2-propynyl) 2) 2-propenyl phosphinate, 3-butenyl di (2-propynyl) phosphinate, 2 Propynyl (2-propenyl) phosphinic acid 2-propenyl, and 2-propynyl (2-propenyl) phosphinic acid 3-phosphinic acid esters butenyl;

2-propenyl phosphonate methyl 2-propynyl, methyl 2-butenyl phosphonate (2-propynyl), 2-propenyl phosphonic acid (2-propynyl) (2-propenyl), 3-butenyl phosphonic acid (3-butenyl) (2-propynyl) ), 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl), 2-butenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl), 2-propenylphosphonic acid (1,1 -Dimethyl-2-propynyl) (2-propenyl), and 3-butenylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl), methylphosphonic acid (2-propynyl) (2-propenyl), methylphosphonic acid (3-butenyl) (2-propynyl), methyl phosphonic acid (1,1-dimethyl-2-pro) Pinyl) (2-propenyl), methylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl), ethylphosphonic acid (2-propynyl) (2-propenyl), ethylphosphonic acid (3-butenyl) ( Phosphonic esters such as 2-propynyl), ethylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl), and ethylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl) ;

Phosphoric acid (methyl) (2-propenyl) (2-propynyl), phosphoric acid (ethyl) (2-propenyl) (2-propynyl), phosphoric acid (2-butenyl) (methyl) (2-propynyl), phosphoric acid (2-butenyl) (ethyl) (2-propynyl), phosphoric acid (1,1-dimethyl-2-propynyl) (methyl) (2-propenyl), phosphoric acid (1,1-dimethyl-2-propynyl) ( Ethyl) (2-propenyl), phosphoric acid (2-butenyl) (1,1-dimethyl-2-propynyl) (methyl), and phosphoric acid (2-butenyl) (ethyl) (1,1-dimethyl-2-) Phosphoric esters such as propynyl);
Among these, compounds having an alkynyloxy group are preferable because they form a negative electrode film more stably in the electrolytic solution.

further,
2-propynyl methyl carbonate, di-2-propynyl carbonate, 2-butyne-1,4-diol dimethyl dicarbonate, 2-propynyl acetate, 2-butyne-1,4-diol diacetate, methyl oxalate 2-propynyl Compounds such as di-2-propynyl oxalate are particularly preferable from the viewpoint of improving the storage characteristics.

  The compounds having a triple bond may be used alone or in any combination of two or more in any proportion. There is no restriction | limiting in the compounding quantity of the compound which has a triple bond with respect to the whole non-aqueous electrolyte solution of this invention, Although it is arbitrary unless the effect of this invention is impaired remarkably, Usually with respect to the non-aqueous electrolyte of this invention. 01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, usually 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less Let When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.

1-5-4. Other Auxiliary Agents As the other auxiliary agents, known auxiliary agents other than the above-mentioned auxiliary agents can be used. As other adjuvants,
Carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate;
Spiro compounds such as 2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane;
Ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolene, diphenyl sulfone, N, N-dimethyl methane sulfonamide, N, N-diethyl methane sulfonamide, vinyl Methyl sulfonate, ethyl vinyl sulfonate, allyl vinyl sulfonate, propargyl vinyl sulfonate, methyl allyl sulfonate, ethyl allyl sulfonate, allyl allyl sulfonate, propargyl allyl sulfonate, 1,2-bis (vinyl sulfonyloxy) Sulfur-containing compounds such as ethane;

Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methyl succinimide;
Trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, dimethyl vinylphosphonate, diethyl vinylphosphonate, diethylphospho Phosphorus-containing compounds such as ethyl noacetate, methyl dimethylphosphinate, ethyl diethylphosphinate, trimethylphosphine oxide, triethylphosphine oxide and the like;

Hydrocarbon compounds such as heptane, octane, nonane, decane and cycloheptane;
Fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, hexafluorobenzene and benzotrifluoride;
Etc. These may be used alone or in combination of two or more. By adding these assistants, capacity retention characteristics and cycle characteristics after high temperature storage can be improved.

The amount of the other auxiliary agent is not particularly limited, and is optional unless the effects of the present invention are significantly impaired. The other auxiliary agent is usually 0.01% by mass or more and 10% by mass or less in 100% by mass of the non-aqueous electrolytic solution. Within this range, the effects of the other auxiliary agents can be sufficiently exhibited, and situations in which battery characteristics such as high load discharge characteristics are degraded can be easily avoided.
The blending amount of the other auxiliary agent is preferably 0.1% by mass or more, more preferably 0.3% by mass, more preferably 0.5% by mass, and particularly preferably 1.0% by mass. Preferably it is 5 mass% or less, More preferably, it is 3 mass% or less, More preferably, it is 2 mass%, Especially preferably, it is 1 mass% or less.

As mentioned above, the above-mentioned non-aqueous electrolyte solution also contains the thing which exists inside the non-aqueous electrolyte solution battery as described in this invention.
Specifically, components of the non-aqueous electrolytic solution such as a lithium salt, a solvent, and an auxiliary agent are separately synthesized, and the non-aqueous electrolytic solution is prepared from those substantially isolated, and the method described below is used. In the case of a non-aqueous electrolytic solution in a non-aqueous electrolytic solution battery obtained by pouring into a separately assembled battery, or the components of the non-aqueous electrolytic solution of the present invention are individually put in the battery, When the same composition as the non-aqueous electrolyte solution of the present invention is obtained by mixing at the same time, a compound constituting the non-aqueous electrolyte solution of the present invention is generated in the non-aqueous electrolyte solution battery. The case where the same composition as the aqueous electrolyte solution is obtained is also included.

2. Battery Configuration The non-aqueous electrolytic solution battery of the present invention is suitable for use as an electrolytic solution for secondary batteries, for example, lithium secondary batteries among non-aqueous electrolytic solution batteries. Hereinafter, a non-aqueous electrolytic solution battery using the non-aqueous electrolytic solution of the present invention will be described.
The non-aqueous electrolytic solution battery of the present invention can have a known structure, and typically, a negative electrode and a positive electrode capable of absorbing and desorbing ions (for example, lithium ions); And a liquid.

2-1. Negative electrode The negative electrode active material used for a negative electrode is described below. The negative electrode active material is not particularly limited as long as it can electrochemically store and release lithium ions. Specific examples thereof include carbonaceous materials, alloy materials, lithium-containing metal composite oxide materials, and the like. One of these may be used alone, or two or more of these may be used in combination as desired.

<Anode active material>
Examples of the negative electrode active material include carbonaceous materials, alloy materials, lithium-containing metal composite oxide materials, and the like.
Examples of carbonaceous materials include (1) natural graphite, (2) artificial graphite, (3) amorphous carbon, (4) carbon-coated graphite, (5) graphite-coated graphite, (6) resin-coated graphite, etc. .

(1) Examples of natural graphite include scale-like graphite, scale-like graphite, soil graphite and / or graphite particles obtained by subjecting such graphite to a treatment such as spheroidization or densification. Among these, spherical or ellipsoidal graphite having a spheroidizing treatment is particularly preferable from the viewpoint of particle filling property and charge / discharge rate characteristics.
As an apparatus used for the spheroidizing process, for example, an apparatus which repeatedly gives mechanical action such as compression, friction, shear force and the like including impact force and particle interaction can be used. Specifically, it has a rotor having a large number of blades installed inside the casing, and when the rotor rotates at high speed, mechanical action such as impact compression, friction, and shear force is performed on the carbon material introduced inside. And a device for performing the spheronization process is preferred. In addition, it is preferable to have a mechanism in which the mechanical action is repeatedly given by circulating the carbon material.

  For example, when spheroidizing treatment is performed using the above-mentioned apparatus, the peripheral velocity of the rotating rotor is preferably 30 to 100 m / sec, more preferably 40 to 100 m / sec, and further preferably 50 to 100 m / sec. It is more preferable to do. Also, the treatment can be carried out simply by passing the carbonaceous matter, but it is preferable to treat by circulating or staying in the device for 30 seconds or more, and it is preferable to treat by circulating or staying in the device for 1 minute or more. More preferable.

  (2) As artificial graphite, coal tar pitch, coal-based heavy oil, atmospheric residual oil, petroleum-based heavy oil, aromatic hydrocarbon, nitrogen-containing cyclic compound, sulfur-containing cyclic compound, polyphenylene, polyvinyl chloride, Organic compounds such as polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral, natural polymers, polyphenylene sulfide, polyphenylene oxide, furfuryl alcohol resin, phenol-formaldehyde resin, imide resin are generally in the range of 2500 ° C. or more, usually 3200 ° C. or less What is graphitized at temperature, and grind | pulverized and / or classified as needed, and what is manufactured is mentioned. Under the present circumstances, a silicon containing compound, a boron containing compound, etc. can also be used as a graphitization catalyst. In addition, artificial graphite obtained by graphitizing mesocarbon microbeads separated in the heat treatment process of pitch may be mentioned. Furthermore, artificial graphite of granulated particles consisting of primary particles can also be mentioned. For example, by mixing mesograph microbeads, graphitizable carbonaceous material powder such as coke, graphitizable binder such as tar and pitch, and graphitization catalyst, graphitizing, and grinding as necessary. A plurality of flat particles can be obtained, and graphite particles assembled or combined such that the orientation planes are not parallel may be mentioned.

(3) Amorphous carbon which is heat-treated once or more in a non-graphitizing temperature range (range of 400 to 2200 ° C.) using a graphitizable carbon precursor such as tar or pitch as a raw material as the amorphous carbon Non-graphitizable carbon precursors such as particles and resins may be used as the raw material to heat-treat amorphous carbon particles.
(4) As carbon-coated graphite, it can be obtained by mixing natural graphite and / or artificial graphite and a carbon precursor which is an organic compound such as tar, pitch or resin, and heat-treating at a temperature of 400 to 2300 ° C. once or more. Examples thereof include carbon-graphite composites in which natural graphite and / or artificial graphite are core graphite and amorphous carbon covers the core graphite. The form of the composite may be a whole or a part of the surface, or a plurality of primary particles composited with carbon derived from the carbon precursor as a binder. Also, carbon can be deposited (CVD) on the surface of graphite by reacting natural graphite and / or artificial graphite with hydrocarbon-based gas such as benzene, toluene, methane, propane, volatiles of aromatic series at high temperature, etc. Graphite composites can also be obtained.

(5) Graphite-coated graphite is prepared by mixing natural graphite and / or artificial graphite and a carbon precursor of a graphitizable organic compound such as tar or pitch, resin, etc., once in the range of about 2400 to 3200 ° C. The graphite coated graphite which makes natural graphite and / or artificial graphite which are obtained by heat processing above and / or artificial graphite as core graphite, and the graphitization coats the whole surface or a part of core graphite is mentioned.
(6) As the resin-coated graphite, natural graphite and / or artificial graphite are mixed with a resin etc. and dried at a temperature of less than 400 ° C. Natural graphite and / or artificial graphite obtained as core graphite are used as the resin. Resin-coated graphite which is coated with

Moreover, the carbonaceous material of (1)-(6) may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
As organic compounds such as tar, pitch and resin used in the above (2) to (5), coal-based heavy oil, direct current-based heavy oil, cracking-based petroleum heavy oil, aromatic hydrocarbon, N-ring compound And S-ring compounds, polyphenylenes, organic synthetic polymers, natural polymers, thermoplastic resins, and carbonizable organic compounds selected from the group consisting of thermosetting resins and the like. Moreover, in order to adjust the viscosity at the time of mixing, the raw material organic compound may be dissolved in a low molecular weight organic solvent and used.

Moreover, as natural graphite used as a raw material of nuclear graphite and / or artificial graphite, natural graphite subjected to a spheroidizing treatment is preferable.
As an alloy-based material used as a negative electrode active material, lithium alone, lithium single metal and alloy forming lithium alloy, or oxides, carbides, nitrides, silicides, sulfide thereof as long as lithium can be absorbed and released It may be any of compounds or compounds such as phosphides and is not particularly limited. The single metal and alloy forming the lithium alloy is preferably a material containing Group 13 and Group 14 metal / metalloid elements (ie excluding carbon), more preferably a single metal of aluminum, silicon and tin and It is an alloy or a compound containing these atoms. One of these may be used alone, or two or more of these may be used in any combination and ratio.

<Physical properties of carbonaceous materials>
When using a carbonaceous material as the negative electrode active material, it is desirable to have the following physical properties.
(X-ray parameters)
The d value (interlayer distance) of the lattice plane (002 plane) determined by X-ray diffraction according to the Gakushin method of the carbonaceous material is usually 0.335 nm or more, and usually 0.360 nm or less, 0.350 nm The following are preferable, and 0.345 nm or less is more preferable. The crystallite size (Lc) of the carbonaceous material determined by X-ray diffraction by the Gakushin method is preferably 1.0 nm or more, and more preferably 1.5 nm or more.

(Volume-based average particle size)
The volume-based average particle diameter of the carbonaceous material is a volume-based average particle diameter (median diameter) determined by laser diffraction / scattering method, and is usually 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, 7 μm The above is particularly preferable, and usually, it is 100 μm or less, preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, and particularly preferably 25 μm or less.

If the volume-based average particle size is less than the above range, the irreversible capacity may increase, which may lead to the loss of the initial battery capacity. Moreover, when the said range is exceeded, when producing an electrode by application | coating, it will be easy to become a non-uniform coated surface, and it may be undesirable in the battery manufacture process.
In the measurement of the volume-based average particle size, a carbon powder is dispersed in a 0.2 mass% aqueous solution (about 10 mL) of polyoxyethylene (20) sorbitan monolaurate which is a surfactant, and laser diffraction / scattering type particle size distribution (For example, LA-700 manufactured by Horiba, Ltd.). The median diameter determined by the measurement is defined as the volume-based average particle size of the carbonaceous material of the present invention.

(Raman R value)
The Raman R value of the carbonaceous material is a value measured using a laser Raman spectrum method, and is usually 0.01 or more, preferably 0.03 or more, more preferably 0.1 or more, and usually 1. It is 5 or less, preferably 1.2 or less, more preferably 1 or less, and particularly preferably 0.5 or less.

When the Raman R value is below the above range, the crystallinity of the particle surface may be too high, and the sites at which Li may enter into the layer may decrease as charge and discharge occur. That is, the chargeability may be reduced. In addition, when the negative electrode is densified by pressing after being applied to the current collector, crystals may be easily oriented in a direction parallel to the electrode plate, which may lead to a decrease in load characteristics.
On the other hand, if the above range is exceeded, the crystallinity of the particle surface may be reduced, the reactivity with the non-aqueous electrolyte solution may be increased, and the efficiency may be decreased or gas generation may be increased.

  The measurement of the Raman spectrum is carried out by naturally dropping the sample into the measurement cell and filling it using a Raman spectrometer (for example, Raman spectrometer made by JASCO Corporation), and argon ion laser light (or semiconductor) on the sample surface in the cell It is carried out by rotating the cell in a plane perpendicular to the laser beam while irradiating the laser beam. About the obtained Raman spectrum, intensity IA of peak PA around 1580 cm −1 and intensity IB of peak PB around 1360 cm −1 are measured, and the intensity ratio R (R = IB / IA) is calculated. The Raman R value calculated by the measurement is defined as the Raman R value of the carbonaceous material of the present invention.

Moreover, said Raman measurement conditions are as follows.
Laser wavelength: Ar ion laser 514.5 nm (semiconductor laser 532 nm)
・ Measurement range: 1100 cm-1 to 1730 cm-1
・ Raman R value: background processing,
・ Smoothing processing: Simple average, convolution 5 points

(BET specific surface area)
The BET specific surface area of the carbonaceous material is a value of the specific surface area measured using the BET method, and is usually 0.1 m 2 · g -1 or more, preferably 0.7 m 2 · g -1 or more, 1.0 m 2 · · g-1 or more is more preferable, 1.5 m2 · g-1 or more is particularly preferable, and usually 100 m2 · g-1 or less, 25 m2 · g-1 or less is preferable, 15 m2 · g-1 or less is more preferable , 10 m 2 · g -1 or less is particularly preferable.

When the value of the BET specific surface area falls below this range, the acceptability of lithium at the time of charging when used as a negative electrode material tends to be poor, lithium is likely to be deposited on the electrode surface, and the stability may be reduced. On the other hand, if it exceeds this range, the reactivity with the non-aqueous electrolyte solution increases when used as a negative electrode material, gas generation tends to be large, and a preferable battery may be difficult to obtain.
Measurement of the specific surface area by the BET method is carried out by predrying the sample at 350 ° C. for 15 minutes under flowing nitrogen using a surface area meter (for example, a fully automatic surface area measuring device manufactured by Okura Riken) and then measuring the atmospheric pressure. It is carried out by the nitrogen adsorption BET one-point method according to the gas flow method, using a nitrogen-helium mixed gas which is accurately adjusted so that the value of the relative pressure of nitrogen is 0.3.

(Roundness)
When the degree of circularity is measured as the degree of spherical shape of the carbonaceous material, it is preferable to fall within the following range. The circularity is defined as "circularity = (peripheral length of equivalent circle having the same area as the particle projection shape) / (actual peripheral length of the particle projection shape)", and when the circularity is 1, it is theoretical It becomes a true sphere.
The circularity of particles having a particle diameter of the carbonaceous material in the range of 3 to 40 μm is preferably as close to 1 as possible, preferably 0.1 or more, more preferably 0.5 or more, and more preferably 0.8 or more. 0.85 or more is more preferable, and 0.9 or more is especially preferable. The high current density charge / discharge characteristics improve as the degree of circularity increases. Therefore, when the circularity is less than the above range, the filling property of the negative electrode active material may be reduced, the resistance between particles may be increased, and the high current density charge / discharge characteristics may be deteriorated for a short time.

The measurement of the degree of circularity is performed using a flow type particle image analyzer (for example, FPIA manufactured by Sysmex Corporation). About 0.2 g of a sample is dispersed in a 0.2 mass% aqueous solution (about 50 mL) of polyoxyethylene (20) sorbitan monolaurate which is a surfactant, and irradiated with ultrasonic waves of 28 kHz for 1 minute at a power of 60 W The detection range is specified to 0.6 to 400 μm, and measurement is performed on particles having a particle size in the range of 3 to 40 μm.

  The method for improving the degree of circularity is not particularly limited, but it is preferable to use a sphericization treatment to make it spherical since the shape of the interparticle voids when the electrode body is formed can be obtained. As an example of the spheroidizing process, a mechanical force or a mechanical processing method in which a plurality of fine particles are granulated by a binder or the adhesive force of the particles themselves by mechanically applying a shear force or a compressive force to a spherical shape Can be mentioned.

(Tap density)
The tap density of the carbonaceous material is usually 0.1 g · cm −3 or more, preferably 0.5 g · cm −3 or more, more preferably 0.7 g · cm −3 or more, and 1 g · cm −3 or more. In particular, 2 g · cm −3 or less is preferable, 1.8 g · cm −3 or less is more preferable, and 1.6 g · cm −3 or less is particularly preferable. When the tap density is lower than the above range, the packing density may not be easily increased when used as a negative electrode, and a high capacity battery may not be obtained. Moreover, when the said range is exceeded, the space | gap between particle | grains in an electrode will decrease too much, it will become difficult to ensure the conductivity between particle | grains, and it may be difficult to acquire a preferable battery characteristic.

  The tap density is measured by passing the sample through a 300 μm mesh screen and dropping the sample into a 20 cm 3 tapping cell to fill the sample to the top end face of the cell, and then using a powder density measuring instrument (eg, a tap made by Seishin Enterprise Co., Ltd.) Tapping with a stroke length of 10 mm is performed 1000 times using a denser), and the tap density is calculated from the volume at that time and the mass of the sample.

(Alignment ratio)
The orientation ratio of the carbonaceous material is usually 0.005 or more, preferably 0.01 or more, more preferably 0.015 or more, and usually 0.67 or less. When the orientation ratio is below the above range, the high density charge and discharge characteristics may be degraded. The upper limit of the above range is the theoretical upper limit value of the orientation ratio of the carbonaceous material.
The orientation ratio is measured by X-ray diffraction after pressure-molding the sample. A molding obtained by filling 0.47 g of a sample into a molding machine having a diameter of 17 mm and compressing it at 58.8 MN · m−2 is set using clay to be flush with the surface of the sample holder for measurement. Measure X-ray diffraction. From the obtained peak intensities of (110) diffraction and (004) diffraction of carbon, a ratio represented by (110) diffraction peak intensity / (004) diffraction peak intensity is calculated.

The X-ray diffraction measurement conditions are as follows. "2θ" indicates a diffraction angle.
Target: Cu (Kα ray) graphite monochromator Slit:
Divergence slit = 0.5 degree Photo acceptance slit = 0.15 mm
Scattering slit = 0.5 degree Measurement range and step angle / measurement time:
(110) plane: 75 degrees ≦ 2θ ≦ 80 degrees 1 degree / 60 seconds (004) plane: 52 degrees ≦ 2θ ≦ 57 degrees 1 degree / 60 seconds

(Aspect ratio (powder))
The aspect ratio of the carbonaceous material is usually 1 or more, and usually 10 or less, preferably 8 or less, and more preferably 5 or less. When the aspect ratio exceeds the above range, streaking during electrode plate formation and a uniform coated surface can not be obtained, and the high current density charge / discharge characteristics may be degraded. The lower limit of the above range is the theoretical lower limit of the aspect ratio of the carbonaceous material.

  The measurement of the aspect ratio is performed by magnifying and observing particles of the carbonaceous material with a scanning electron microscope. Carbon material material particles when selecting arbitrary 50 graphite particles fixed to the end face of metal having a thickness of 50 μm or less, rotating and tilting the stage on which the sample is fixed for each, and observing it three-dimensionally The longest diameter A and the shortest diameter B orthogonal to that are measured, and the average value of A / B is determined.

(Coverage)
The negative electrode active material of the present invention may be coated with a carbonaceous material or a graphitic material. Among them, it is preferable from the viewpoint of lithium ion acceptance that it is covered with an amorphous carbonaceous substance, and the coverage is usually 0.5% to 30%, preferably 1% to 25%, more preferably Is 2% or more and 20% or less. When the content is too large, the amorphous carbon portion of the negative electrode active material tends to be large, and the reversible capacity when assembled in a battery tends to be small. If the content is too small, the amorphous carbon site is not uniformly coated on the core graphite particles, and strong granulation is not achieved, and when crushed after firing, the particle size tends to be too small.

The content (coverage) of the carbide derived from the organic compound of the negative electrode active material finally obtained is the amount of the negative electrode active material, the amount of the organic compound and the residue measured by the micro method according to JIS K 2270 It can be calculated by the following equation according to the carbon ratio.
Formula: Coverage of carbide derived from organic compound (%) = (mass of organic compound × residual carbon ratio × 100) / {mass of negative electrode active material + (mass of organic compound × carbon ratio of organic compound)}
(Internal porosity)

  The internal porosity of the negative electrode active material is usually 1% or more, preferably 3% or more, more preferably 5% or more, and still more preferably 7% or more. Also, it is usually less than 50%, preferably 40% or less, more preferably 30% or less, and still more preferably 20% or less. If the internal porosity is too small, the amount of liquid in the particles tends to be small, and the charge / discharge characteristics tend to deteriorate. If the internal porosity is too large, the interparticle gap is small when used as an electrode, and the diffusion of the electrolyte Tend to be inadequate. In addition, in this void, a substance that buffers expansion and contraction of metal particles that can be alloyed with Li, such as amorphous carbon, graphite, resin, etc., is filled in the void by being present or void. It may be

<Metal particles that can be alloyed with Li>
As a method for confirming that the metal particles are metal particles that can be alloyed with Li, identification of metal particle phase by X-ray diffraction, observation of particle structure by electron microscope and elemental analysis, element by fluorescent X-ray Analysis etc. are mentioned.
Any metal particle that can be alloyed with Li can be used, but from the viewpoint of capacity and cycle life, the metal particles can be, for example, Fe, Co, Sb, Bi, Pb, Ni, Ag Preferred are metals or compounds selected from the group consisting of Si, Sn, Al, Zr, Cr, P, S, V, Mn, Nb, Mo, Cu, Zn, Ge, In, Ti and the like. Further, an alloy composed of two or more kinds of metals may be used, and the metal particle may be an alloy particle formed of two or more kinds of metal elements. Among these, a metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn and W or a compound thereof is preferable.
Examples of metal compounds include metal oxides, metal nitrides, metal carbides and the like. Alternatively, an alloy composed of two or more metals may be used.

Among these, Si or Si compounds are preferable in terms of increasing the capacity. In the present specification, Si or Si compounds are generically referred to as Si compounds. Specific examples of the Si compound include SiOx, SiNx, SiCx, SiZxOy (Z = C, N) and the like, preferably SiOx in the general formula. This general formula SiOx is Si dioxide (SiO2) and metal Si
(Si) can be obtained as a raw material, but the value of x is usually 0 ≦ x <2. SiOx has a large theoretical capacity as compared with graphite, and further, amorphous Si or nano-sized Si crystal is easy to get in and out alkali ions such as lithium ions, and it is possible to obtain a high capacity.

Specifically, it is represented as SiOx, x is 0 ≦ x <2, more preferably 0.2 or more and 1.8 or less, still more preferably 0.4 or more and 1.6 Or less, particularly preferably 0.6 or more and 1 or 4 or less, and particularly preferably X = 0. Within this range, it is possible to reduce the irreversible capacity due to the bond between Li and oxygen as well as having a high capacity.
・ Average particle size of metal particles that can be alloyed with Li (d50)
The average particle size (d50) of the metal particles that can be alloyed with Li is usually 0.01 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, still more preferably 0.3 μm from the viewpoint of cycle life It is the above, normally 10 micrometers or less, preferably 9 micrometers or less, and more preferably 8 micrometers or less. When the average particle diameter (d50) is in the above range, volumetric expansion associated with charge and discharge is reduced, and good cycle characteristics can be obtained while maintaining charge and discharge capacity.
The average particle size (d50) is determined by a laser diffraction / scattering particle size distribution measuring method or the like.

-BET specific surface area of metal particles that can be alloyed with Li According to the BET method of metal particles that can be alloyed with Li, the specific surface area is preferably 0.5 to 60 m 2 / g and 1 to 40 m 2 / g. When the specific surface area of the metal particles that can be alloyed with Li according to the BET method is within the above range, the charge and discharge efficiency and discharge capacity of the battery are high, lithium is rapidly taken in and out in high speed charge and discharge, and rate characteristics are excellent.

-Contained oxygen amount of metal particles that can be alloyed with Li The contained oxygen amount of metal particles that can be alloyed with Li is not particularly limited, but usually 0.01 to 8% by mass, 0.05 to 5% by mass Is preferred. The oxygen distribution state in the particle may be present near the surface, present inside the particle, or uniformly present in the particle, but it is particularly preferable to be present near the surface. It is preferable that the content of oxygen of the metal particles that can be alloyed with Li is in the above-mentioned range, because the strong bond between Si and O suppresses the volume expansion associated with charge and discharge and has excellent cycle characteristics.

  The metal particle that can be alloyed with Li and the negative electrode active material that contains graphite particles as described in the present invention may be a mixture in which metal particles that can be alloyed with Li and graphite particles are mixed in mutually independent particles. Alternatively, it may be a composite in which metal particles that can be alloyed with Li are present on the surface or inside of the graphite particles. In the present specification, a composite (also referred to as a composite particle) is not particularly limited as long as it is a particle containing metal particles and carbonaceous materials that can be alloyed with Li, but preferably it is preferably an alloy with Li Metallizable metal particles and carbonaceous matter are particles integrated by physical and / or chemical bonding. In a more preferable form, each solid component is dispersed and present in the particles to such an extent that metal particles and carbonaceous substances which can be alloyed with Li are present at least on both the surface of the composite particle and inside the bulk. In order to integrate them by physical and / or chemical bonding, carbonaceous substances are present in such a form. A more specific preferred embodiment is a composite material comprising at least a metal particle alloyable with Li and a graphite particle, wherein the graphite particle, preferably, a particle having a folded structure in which natural graphite has a curved surface In the negative electrode active material, metal particles capable of being alloyed with Li are present in gaps in the folded structure having the curved surface. Also, the gap may be a void, or a material such as amorphous carbon, a graphitic substance, a resin, or the like that buffers expansion and contraction of metal particles that can be alloyed with Li is present in the gap. It is also good.

-Content ratio of metal particles that can be alloyed with Li The content ratio of metal particles that can be alloyed with Li to the total of metal particles that can be alloyed with Li and graphite particles is usually at least 0.1 mass%, preferably 1 The content is preferably at least 2% by mass, more preferably at least 3% by mass, particularly preferably at least 5% by mass. Also, usually 99% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, still more preferably 25% by mass or less, particularly preferably 15% or less, most preferably It is 10% by mass or less. Within this range, it is preferable in that sufficient capacity can be obtained.

  The alloy-based material negative electrode can be manufactured using any known method. Specifically, as a method of manufacturing a negative electrode, for example, a method in which a negative electrode active material as described above to which a binder, a conductive material, etc. is added is directly roll-formed to form a sheet electrode, or compression molded to form a pellet electrode The negative electrode is usually formed on a current collector for the negative electrode (hereinafter sometimes referred to as “negative electrode current collector”) by a method such as a coating method, a vapor deposition method, a sputtering method, or a plating method. The method of forming the thin film layer (negative electrode active material layer) containing an active material is used. In this case, a binder, a thickener, a conductive material, a solvent, and the like are added to the above-described negative electrode active material to form a slurry, which is applied to the negative electrode current collector, dried and pressed to increase the density. The negative electrode active material layer is formed on the negative electrode current collector.

Examples of the material of the negative electrode current collector include steel, copper alloy, nickel, nickel alloy, stainless steel and the like. Among these, copper foil is preferable in terms of easy processing into a thin film and cost.
The thickness of the negative electrode current collector is usually 1 μm or more, preferably 5 μm or more, and usually 100 μm or less, preferably 50 μm or less. When the thickness of the negative electrode current collector is too thick, the capacity of the entire battery may be too low, and conversely, when it is too thin, handling may be difficult.

  In order to improve the binding effect with the negative electrode active material layer formed on the surface, the surface of the negative electrode current collector is preferably roughened in advance. The surface is roughened by blasting, rolling with a rough surface roll, abrasive cloth with abrasive particles fixed, grinding machine with a wire brush equipped with a grindstone, emery buff, steel wire, etc. Chemical polishing method, electro polishing method, chemical polishing method, and the like.

  Also, in order to reduce the mass of the negative electrode current collector and improve the energy density per mass of the battery, it is also possible to use a perforated type negative electrode current collector such as expanded metal or punching metal. The mass of the negative electrode current collector of this type can also be changed to white by changing the aperture ratio. In addition, when the negative electrode active material layer is formed on both sides of this type of negative electrode current collector, peeling of the negative electrode active material layer is further difficult to occur due to the rivet effect through the holes. However, if the aperture ratio becomes too high, the contact area between the negative electrode active material layer and the negative electrode current collector may be reduced, and the adhesive strength may be lowered.

The slurry for forming the negative electrode active material layer is usually prepared by adding a binder, a thickener and the like to the negative electrode material. In addition, the "negative electrode material" in this specification shall refer to the material which united the negative electrode active material and the electrically conductive material.
The content of the negative electrode active material in the negative electrode material is preferably 70% by mass or more, particularly 75% by mass or more, and usually 97% by mass or less, particularly 95% by mass or less. When the content of the negative electrode active material is too small, the capacity of the secondary battery using the obtained negative electrode tends to be insufficient, and when the content is too large, the content of the conductive agent is relatively insufficient, so that electricity as a negative electrode is obtained. It tends to be difficult to ensure conductivity. In the case where two or more negative electrode active materials are used in combination, the total amount of the negative electrode active materials may be set to satisfy the above range.

Examples of the conductive material used for the negative electrode include metal materials such as copper and nickel; and carbon materials such as graphite and carbon black. One of these may be used alone, or two or more of these may be used in any combination and ratio. In particular, it is preferable to use a carbon material as the conductive material because the carbon material also acts as an active material. The content of the conductive material in the negative electrode material is preferably 3% by mass or more, particularly 5% by mass or more, and usually 30% by mass or less, particularly 25% by mass or less. If the content of the conductive material is too small, the conductivity tends to be insufficient. If the content is too large, the content of the negative electrode active material or the like is relatively short, and the battery capacity and the strength tend to be reduced. When two or more conductive materials are used in combination, the total amount of the conductive materials may satisfy the above range.

  As a binder used for a negative electrode, if it is a safe material with respect to the solvent and electrolyte solution used at the time of electrode manufacture, an arbitrary thing can be used. For example, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, styrene butadiene rubber isoprene rubber, butadiene rubber, ethylene acrylic acid copolymer, ethylene methacrylic acid copolymer and the like can be mentioned. One of these may be used alone, or two or more of these may be used in any combination and ratio. The content of the binder is preferably 0.5 parts by mass or more, particularly 1 part by mass or more, and usually 10 parts by mass or less, particularly 8 parts by mass or less, based on 100 parts by mass of the negative electrode material. When the content of the binder is too small, the strength of the obtained negative electrode tends to be insufficient. When the content is too large, the content of the negative electrode active material and the like is relatively insufficient, so the battery capacity and the conductivity tend to be insufficient. It becomes. When two or more binders are used in combination, the total amount of the binders may be within the above range.

  Examples of the thickener used for the negative electrode include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and the like. One of these may be used alone, or two or more of these may be used in any combination and ratio. A thickener may be used as necessary, but when used, the content of the thickener in the negative electrode active material layer is usually in the range of 0.5% by mass to 5% by mass. Is preferred.

  The slurry for forming the negative electrode active material layer is prepared using the aqueous solvent or the organic solvent as a dispersion medium by mixing the above-mentioned negative electrode active material with a conductive agent, a binder and a thickener as required. Ru. Although water is usually used as the aqueous solvent, it may be used in combination with organic solvents such as alcohols such as ethanol and cyclic amides such as N-methyl pyrrolidone in a range of 30% by mass or less with respect to water You can also. Also, as the organic solvent, usually, cyclic amides such as N-methyl pyrrolidone, linear amides such as N, N-dimethylformamide, N, N-dimethylacetamide, and aromatic carbonization such as anisole, toluene, xylene and the like Hydrogens, alcohols such as butanol, cyclohexanol and the like, and cyclic amides such as N-methylpyrrolidone, linear amides such as N, N-dimethylformamide, N, N-dimethylacetamide and the like are preferable among them . In addition, these may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The obtained slurry is applied onto the above-described negative electrode current collector, dried, and pressed to form a negative electrode active material layer. The method of application is not particularly limited, and a method known per se can be used. The drying method is also not particularly limited, and known methods such as natural drying, heat drying and reduced pressure drying can be used.

<Structure of negative electrode and preparation method>
For production of the electrode, any known method can be used as long as the effects of the present invention are not significantly impaired. For example, a binder, a solvent, and, if necessary, a thickener, a conductive material, a filler and the like are added to the negative electrode active material to form a slurry, which is applied to a current collector, dried and pressed. Can.
In the case of using an alloy-based material, a method such as evaporation, sputtering or plating is used.
The method of forming the thin film layer (negative electrode active material layer) containing the above-mentioned negative electrode active material is also used.

(Electrode density)
The electrode structure when making the negative electrode active material into an electrode is not particularly limited, but the density of the negative electrode active material present on the current collector is preferably 1 g · cm −3 or more, and 1.2 g · cm −3 or more Is more preferable, 1.3 g · cm −3 or more is particularly preferable, and 2.2 g · cm −3 or less is preferable, 2.1 g · cm −3 or less is more preferable, and 2.0 g · cm −3 or less More preferably, 1.9 g · cm −3 or less is particularly preferable. When the density of the negative electrode active material present on the current collector exceeds the above range, the negative electrode active material particles are destroyed, and the initial irreversible capacity increases, or the non-aqueous system near the current collector / negative electrode active material interface In some cases, the high current density charge / discharge characteristics may be deteriorated due to the decrease in the permeability of the electrolyte solution. If the above range is exceeded, the conductivity between the negative electrode active materials may be reduced, the battery resistance may be increased, and the capacity per unit volume may be reduced.

2-2. Positive electrode <positive electrode active material>
The positive electrode active material (lithium transition metal based compound) used for the positive electrode will be described below.
Lithium transition metal compounds
The lithium transition metal-based compound is a compound having a structure capable of releasing and inserting Li ions, and examples thereof include a sulfide, a phosphate compound, and a lithium transition metal composite oxide. As the sulfide, a compound having a two-dimensional layered structure such as TiS 2 or MoS 2 or a strong three-dimensional framework structure represented by the general formula MexMo 6 S 8 (Me is various transition metals including Pb, Ag, and Cu) Shubrel compounds and the like can be mentioned. The phosphate compounds include those having an olivine structure, and are generally represented by LiMePO4 (Me is at least one transition metal), and specific examples include LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4 and the like Be As lithium transition metal complex oxide, what belongs to the spinel structure in which three-dimensional diffusion is possible, and the thing which belongs to the layered structure which enables two-dimensional diffusion of lithium ion is mentioned. One having a spinel structure is generally represented as LiMe 2 O 4 (Me is at least one transition metal), and specific examples include LiMn 2 O 4, LiCoMnO 4, LiNi 0.5 Mn 1.5 O 4, LiCoVO 4 and the like. Those having a layered structure are generally represented as LiMeO 2 (Me is at least one transition metal). Specifically, LiCoO2, LiNiO2, LiNi1-xCoxO2, LiNi1-x-yCoxMnyO2, LiNi0.5Mn0.5O2, Li1.2Cr0.4Mn0.4O2, Li1.2Cr0.4Ti0.4O2, LiMnO2 etc. are mentioned.

<composition>
Moreover, it is mentioned that a lithium containing transition metal compound is a lithium transition metal type-compound shown, for example by a following composition formula (A) or (B).
1) In the case of a lithium transition metal compound represented by the following composition formula (A)
Li1 + xMO2 (A)
However, x is usually 0 or more and 0.5 or less. M is an element composed of Ni and Mn, or Ni, Mn and Co, and the Mn / Ni molar ratio is usually 0.1 or more and 5 or less. The Ni / M molar ratio is usually 0 or more and 0.5 or less. The Co / M molar ratio is usually 0 or more and 0.5 or less. In addition, the rich part of Li represented by x may be substituted by the transition metal site M.

In the above composition formula (A), the atomic ratio of the amount of oxygen is described as 2 for convenience, but it may have some nonstoichiometry. Further, x in the above composition formula is a preparation composition at the production stage of the lithium transition metal based compound. Usually, batteries in the market are aged after the batteries are assembled. Therefore, the amount of Li in the positive electrode may be lost as a result of charge and discharge. In that case, x may be measured as −0.65 or more and 1 or less when discharged to 3 V in composition analysis.

Further, the lithium transition metal-based compound is obtained by firing at a high temperature under an oxygen-containing gas atmosphere to improve crystallinity of the positive electrode active material, and the material is excellent in battery characteristics.
Furthermore, the lithium transition metal-based compound represented by the composition formula (A) may be a solid solution with Li2MO3 called 213 layer as represented by the following formula (A ').
α Li 2 MO 3 · (1-α) Li M 'O 2 (A')
In the general formula, α is a number that satisfies 0 <α <1.

M is at least one metal element having an average oxidation number of 4+, and specifically, at least one metal element selected from the group consisting of Mn, Zr, Ti, Ru, Re, and Pt.
M ′ is at least one metal element having an average oxidation number of 3+, preferably at least one metal element selected from the group consisting of V, Mn, Fe, Co and Ni, more preferably It is at least one metal element selected from the group consisting of Mn, Co and Ni.

2) In the case of a lithium transition metal based compound represented by the following general formula (B).
Li [LiaMbMn2-b-a] O4 + δ (B)
However, M is an element composed of at least one of transition metals selected from Ni, Cr, Fe, Co, Cu, Zr, Al and Mg.
The value of b is usually 0.4 or more and 0.6 or less.
If the value of b is in this range, the energy density per unit weight in the lithium transition metal based compound is high.

  The value of a is usually 0 or more and 0.3 or less. Further, a in the above composition formula is a feed composition at the production stage of the lithium transition metal based compound. Usually, batteries in the market are aged after the batteries are assembled. Therefore, the amount of Li in the positive electrode may be lost as a result of charge and discharge. In that case, a may be measured at −0.65 or more and 1 or less when discharged to 3 V in composition analysis.

If the value of a is in this range, good load characteristics can be obtained without significantly impairing the energy density per unit weight of the lithium transition metal based compound.
Furthermore, the value of δ is usually in the range of ± 0.5.
If the value of δ is in this range, the stability as a crystal structure is high, and the cycle characteristics and high temperature storage of a battery having an electrode manufactured using this lithium transition metal based compound are good.

Here, the chemical meaning of the lithium composition in the lithium nickel manganese composite oxide, which is the composition of the lithium transition metal based compound, will be described in more detail below.
In order to obtain a and b of the composition formula of the lithium transition metal based compound, each transition metal and lithium are analyzed by inductively coupled plasma emission spectrometry (ICP-AES) to obtain the ratio of Li / Ni / Mn. Calculated by

From a structural point of view, it is considered that the lithium relating to a is substituted into the same transition metal site. Here, due to the lithium according to a, the average valence of M and manganese becomes larger than 3.5 according to the principle of charge neutrality.
Further, the lithium transition metal-based compound may be fluorine-substituted and is described as LiMn 2 O 4 -xF 2 x.

<blend>
Specific examples of the lithium transition metal compound having the above composition include, for example, Li1 + xNi0.5Mn0.5O2, Li1 + xNi0.85Co0.10Al0.05O2, Li1 + xNi0.33Mn0.33Co0.33O2, Li1 + xNi0.45Mn0.45Co0.1O2, Li1 + xMn1.8Al0 And 2O4, Li1 + xMn1.5Ni0.5O4 and the like. One of these lithium transition metal compounds may be used alone, or two or more thereof may be blended and used.

Introduction of different elements
In addition, different elements may be introduced into the lithium transition metal based compound. As different elements, B, Na, Mg, Al, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Ru, Rh, Pd, Ag, In, Sb, Te , Ba, Ta, Mo, W, Re, Os, Ir, Pt, Au, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Bi And N, F, S, Cl, Br, I, As, Ge, P, Pb, Sb, Si and Sn are selected from any one or more of them. These different elements may be incorporated into the crystal structure of the lithium transition metal based compound, or not incorporated into the crystal structure of the lithium transition metal based compound, either alone or as a compound on the particle surface or grain boundary. It may be unevenly distributed.

[Positive Electrode for Lithium Secondary Battery]
The positive electrode for a lithium secondary battery is obtained by forming a positive electrode active material layer containing the above-mentioned lithium transition metal based compound powder for lithium secondary battery positive electrode material and a binder on a current collector.
In the positive electrode active material layer, a positive electrode material, a binder, and a conductive material, a thickener, etc., which are optionally used, are mixed in a dry state to form a sheet, and is pressed to the positive electrode current collector Alternatively, these materials are dissolved or dispersed in a liquid medium to form a slurry, which is applied to a positive electrode current collector and dried.

  As a material of the positive electrode current collector, usually, a metal material such as aluminum, stainless steel, nickel plating, titanium, tantalum or the like, or a carbon material such as carbon cloth or carbon paper is used. Further, as the shape, in the case of metal material, metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punch metal, foam metal etc., in the case of carbon material, carbon plate, carbon thin film, carbon cylinder Etc. The thin film may be formed in a mesh shape as appropriate.

When a thin film is used as the positive electrode current collector, the thickness thereof is arbitrary, but a range of 1 μm to 100 mm is usually preferable. If the thickness is thinner than the above range, the strength required for the current collector may be insufficient, while if it is thicker than the above range, the handleability may be impaired.
The binder used to manufacture the positive electrode active material layer is not particularly limited, and in the case of the coating method, any material that is stable to the liquid medium used at the time of electrode manufacture may be used. Specific examples include polyethylene, Resin polymers such as polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, cellulose, nitrocellulose, SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), fluororubber, isoprene rubber, butadiene rubber, ethylene・ Rubber-like polymers such as propylene rubber, styrene / butadiene / styrene block copolymers and hydrogenated products thereof, EPDM (ethylene / propylene / diene terpolymers), styrene / ethylene / butadiene / ethylene copolymers, Styrene · Isoprene Styrene Bro Thermoplastic elastomeric polymers such as co-polymers and their hydrogenated products, syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymers, propylene / α-olefin copolymers, etc. Ion conductivity of soft polymer, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene, fluorinated polymer such as polytetrafluoroethylene-ethylene copolymer, alkali metal ion (especially lithium ion) The polymer composition etc. which it has are mentioned. One of these substances may be used alone, or two or more of these substances may be used in any combination and ratio.

The proportion of the binder in the positive electrode active material layer is usually 0.1% by weight or more and 80% by weight or less. When the proportion of the binder is too low, the positive electrode active material can not be sufficiently retained, the mechanical strength of the positive electrode is insufficient, and battery performance such as cycle characteristics may be deteriorated. It may lead to a decrease in battery capacity and conductivity.
The positive electrode active material layer usually contains a conductive material to enhance the conductivity. The type is not particularly limited, but specific examples thereof include metal materials such as copper and nickel, graphite such as natural graphite, artificial graphite and the like, carbon black such as acetylene black, amorphous carbon such as needle coke and the like And carbon materials of the One of these substances may be used alone, or two or more of these substances may be used in any combination and ratio. The proportion of the conductive material in the positive electrode active material layer is usually 0.01% by weight or more and 50% by weight or less. If the proportion of the conductive material is too low, the conductivity may be insufficient, and if too high, the battery capacity may decrease.

  As a liquid medium for forming a slurry, it is possible to dissolve or disperse a lithium transition metal based compound powder which is a positive electrode material, a binder, and a conductive material and a thickener which are optionally used. The type of the solvent is not particularly limited, and either an aqueous solvent or an organic solvent may be used. Examples of the aqueous solvent include water, alcohol and the like, and examples of the organic solvent include N-methyl pyrrolidone (NMP), dimethylformamide, dimethyl acetamide, methyl acetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyl triamine, N , N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran (THF), toluene, acetone, dimethyl ether, dimethyl acetamide, hexamethyl phosphaamide, dimethyl sulfoxide, benzene, xylene, quinoline, pyridine, methyl naphthalene, hexane, etc. be able to. In particular, when an aqueous solvent is used, a dispersant is added to the thickener together with the thickener, and a slurry such as SBR is used. In addition, one of these solvents may be used alone, or two or more thereof may be used in any combination and ratio.

The content ratio of the lithium transition metal based compound powder as the positive electrode material in the positive electrode active material layer is usually 10% by weight or more and 99.9% by weight or less. When the proportion of the lithium transition metal based compound powder in the positive electrode active material layer is too large, the strength of the positive electrode tends to be insufficient, and when it is too small, the capacity may be insufficient.
The thickness of the positive electrode active material layer is usually about 10 to 200 μm.

The electrode density of the positive electrode after pressing is usually 2.2 g / cm 3 or more and 4.2 g / cm 3 or less.
In order to increase the packing density of the positive electrode active material, the positive electrode active material layer obtained by coating and drying is preferably consolidated by a roller press or the like.
Thus, a positive electrode for lithium secondary battery can be prepared.

2-3. Separator In order to prevent a short circuit, a separator is usually interposed between the positive electrode and the negative electrode. In this case, the non-aqueous electrolytic solution of the present invention is usually used by impregnating this separator.
The material and shape of the separator are not particularly limited, and any known ones can be adopted as long as the effects of the present invention are not significantly impaired. Among them, resins, glass fibers, inorganic substances, etc., which are made of a material stable to the non-aqueous electrolyte solution of the present invention, are used, and porous sheet or non-woven fabric-like articles etc. excellent in liquid retention are used. Is preferred.

  As a material of resin and a glass fiber separator, polyolefins, such as polyethylene and a polypropylene, aromatic polyamide, polytetrafluoroethylene, polyether sulfone, a glass filter etc. can be used, for example. Among them, preferred are glass filters and polyolefins, and more preferred are polyolefins. One of these materials may be used alone, or two or more of these materials may be used in any combination and ratio.

  The thickness of the separator is arbitrary but is usually 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and usually 50 μm or less, preferably 40 μm or less, and more preferably 30 μm or less. If the separator is thinner than the above range, the insulation and mechanical strength may be reduced. When the thickness is more than the above range, not only the battery performance such as rate characteristics may be degraded, but also the energy density of the whole non-aqueous electrolyte secondary battery may be degraded.

  Furthermore, when a porous sheet such as a porous sheet or non-woven fabric is used as the separator, the porosity of the separator is optional, but is usually 20% or more, preferably 35% or more, and more preferably 45% or more, Also, it is usually 90% or less, preferably 85% or less, and more preferably 75% or less. When the porosity is smaller than the above range, the film resistance tends to be increased and the rate characteristic tends to be deteriorated. Moreover, when it is larger than the said range, it exists in the tendency for the mechanical strength of a separator to fall and for insulation to fall.

The average pore diameter of the separator is also optional, but is usually 0.5 μm or less, preferably 0.2 μm or less, and usually 0.05 μm or more. When the average pore size exceeds the above range, a short circuit is likely to occur. If the above range is exceeded, the film resistance may increase and the rate characteristics may deteriorate.
On the other hand, as the inorganic material, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used, and those having a particle shape or fiber shape are used. Used.

  As the form, a thin film such as a non-woven fabric, a woven fabric and a microporous film is used. In the thin film form, one having a pore diameter of 0.01 to 1 μm and a thickness of 5 to 50 μm is suitably used. A separator formed by forming a composite porous layer containing particles of the above-mentioned inorganic material on the surface layer of the positive electrode and / or the negative electrode using a binder made of resin other than the above-mentioned independent thin film shape can be used. For example, alumina particles having a 90% particle size of less than 1 μm may be formed on both sides of the positive electrode to form a porous layer using a fluorine resin as a binder.

  The characteristics of the non-electrolyte secondary battery of the separator can be grasped by the Gurley value. The Gurley value indicates the difficulty of air passing through in the film thickness direction, and since 100 ml of air is represented by the number of seconds required to pass through the film, smaller numbers are easier to pass through and larger numbers are larger. It means that one is more difficult to pass through. That is, the smaller the value, the better the communication in the thickness direction of the film, and the larger the value, the worse the communication in the thickness direction of the film. The communication property is the degree of connection of the holes in the film thickness direction. If the Gurley value of the separator of the present invention is low, it can be used in various applications. For example, when it is used as a separator of a non-aqueous lithium secondary battery, a low Gurley value means that lithium ions can be easily moved, which is preferable because the battery performance is excellent. The Gurley value of the separator is optionally but preferably 10 to 1000 seconds / 100 ml, more preferably 15 to 800 seconds / 100 ml, and still more preferably 20 to 500 seconds / 100 ml. If the Gurley value is 1000 seconds / 100 ml or less, the electric resistance is substantially low and it is preferable as a separator.

2-4. Battery design <Electrode group>
The electrode group has a laminated structure in which the positive electrode plate and the negative electrode plate described above are intervened by the separator, and a structure in which the positive electrode plate and the negative electrode plate are spirally wound through the separator. Any one may be used. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is usually 40% or more, preferably 50% or more, and usually 90% or less, preferably 80% or less .

  When the electrode group occupancy rate falls below the above range, the battery capacity decreases. Further, when the above range is exceeded, the void space is small, the battery becomes high temperature, the members expand, the vapor pressure of the liquid component of the electrolyte becomes high, and the internal pressure rises, and the charge and discharge repetition performance as the battery Or, the characteristics such as high temperature storage may be lowered, and furthermore, a gas release valve may be actuated to release the internal pressure to the outside.

<Exterior case>
The material of the outer case is not particularly limited as long as it is a stable substance to the non-aqueous electrolyte used. Specifically, a nickel-plated steel sheet, metals such as stainless steel, aluminum or aluminum alloy, magnesium alloy or the like, or a laminated film (laminated film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, metals of aluminum or aluminum alloy and laminate films are preferably used.

  In the outer case using metals, the metals are welded to form a hermetically sealed structure by laser welding, resistance welding, ultrasonic welding, or a caulking structure is formed using the above metals via a resin gasket. The thing is mentioned. In the outer case using the above-mentioned laminated film, those having a sealing and sealing structure by thermally fusing the resin layers to each other may be mentioned. In order to improve the sealing property, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, in the case where the resin layer is heat-sealed through the current collection terminal to form a sealed structure, the metal and the resin are joined, and therefore, a resin having a polar group or a modification having a polar group introduced as an intervening resin Resin is preferably used.

<Protective element>
As a protection element, PTC (Positive Temperature Coefficient), whose resistance increases when abnormal heat generation or excessive current flows, thermal fuse, thermistor, interrupt the current flowing in the circuit due to rapid increase of internal pressure of battery and internal temperature at abnormal heat generation. Valve (current shutoff valve) etc. can be used. The protective element is preferably selected under conditions which do not operate under normal use of high current, and it is more preferable to design it so as not to lead to abnormal heat generation or thermal runaway without the protective element.

(Exterior body)
The non-aqueous electrolyte secondary battery of the present invention is usually constructed by housing the above non-aqueous electrolyte, the negative electrode, the positive electrode, the separator and the like in an outer package (outer case). The outer package is not limited, and any known one can be adopted as long as the effects of the present invention are not significantly impaired.
The material of the outer case is not particularly limited as long as the material is stable to the non-aqueous electrolyte used. Specifically, a nickel-plated steel sheet, stainless steel, aluminum or aluminum alloy, magnesium alloy, metals such as nickel or titanium, or a laminated film (laminated film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, metals of aluminum or aluminum alloy and laminate films are preferably used.

In the outer case using the above metals, the metals are welded together by laser welding, resistance welding, ultrasonic welding to form a hermetically sealed structure, or a caulking structure using the above metals via a resin gasket. The thing to do is mentioned. In the outer case using the above-mentioned laminated film, those having a sealing and sealing structure by thermally fusing the resin layers to each other may be mentioned. In order to improve the sealing property, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, in the case where the resin layer is heat-sealed through the current collection terminal to form a sealed structure, the metal and the resin are joined, and therefore, a resin having a polar group or a modification having a polar group introduced as an intervening resin Resin is preferably used.

  The shape of the outer case is also arbitrary, and may be, for example, cylindrical, square, laminate, coin or large size.

EXAMPLES The present invention will be more specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.
Abbreviations and structures of compounds used in Examples and Comparative Examples are shown below.

Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-7
[Production of positive electrode]
85% by mass of lithium-nickel-cobalt-manganese composite oxide (Li _1.05 Ni _0.33 Mn _0.33 Co _0.33 O ₂ ) as a positive electrode active material and 10% by mass of acetylene black as a conductive material 5% by mass of polyvinylidene fluoride (PVdF) as a bonding material was mixed in an N-methylpyrrolidone solvent with a disperser to form a slurry. This was uniformly applied on both sides of a 21 μm thick aluminum foil and dried, and then pressed to form a positive electrode.

[Fabrication of negative electrode]
50 g of Si fine particles with an average particle size of 0.2 μm are dispersed in 2000 g of scaly graphite with an average particle size of 35 μm and charged into a hybridization system (manufactured by Nara Machinery Co., Ltd.) It was retained and processed to obtain a composite of Si and graphite particles. Coal tar pitch was mixed as an organic compound to be a carbonaceous substance so that the coverage after firing was 7.5%, and the obtained composite was kneaded and dispersed by a twin-screw kneader. The obtained dispersion was introduced into a baking furnace and baked at 1000 ° C. for 3 hours in a nitrogen atmosphere. The obtained fired product was further crushed with a hammer mill and sieved (45 μm) to produce a negative electrode active material. The content of silicon element, the average particle diameter d50, the tap density, and the specific surface area measured by the measurement method were 2.0 mass%, 20 μm, 1.0 g / cm 3 and 7.2 m 2 / g, respectively.

  The above negative electrode active material, a thickener, and an aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as a thickener and a binder, and an aqueous dispersion of styrene-butadiene rubber (concentration of 50 mass of styrene-butadiene rubber) %), Mixed with a disperser and made into a slurry. The slurry was uniformly coated on one side of a 10 μm thick copper foil and dried, and then pressed to form a negative electrode. In addition, in the negative electrode after drying, it produced so that it might become mass ratio of the above-mentioned negative electrode active material: carboxymethylcellulose sodium: styrene butadiene rubber = 97.5: 1: 1.5.

[Preparation of non-aqueous electrolyte solution]
1 mole / L of LiPF 6 sufficiently dried in a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) (volume ratio 3: 7) under a dry argon atmosphere (as a concentration in the non-aqueous electrolyte) What was made to melt | dissolve (this is called the reference electrolyte solution 1), and 2.0 mass% of vinylene carbonate (VC) and fluoro ethylene carbonate (MFEC) were respectively added (this is called the reference electrolyte solution 2). Examples 1-1 to 1-6 and comparative examples 1-1 to 1-6 are the whole reference electrolyte solution 2, Examples 1 to 7 to 1-10, and comparative example 1-7 the whole reference electrolyte 1 The compounds were added in the proportions described in Table 1 below to prepare an electrolytic solution. However, Comparative Example 1-1 and Comparative Example 1-7 are the reference electrolyte solution 2 and the reference electrolyte solution 1 respectively.

[Manufacture of non-aqueous electrolyte battery (laminated type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained was wrapped with an aluminum laminate film, and after injecting an electrolytic solution described later, the battery element was vacuum sealed to produce a sheet-like non-aqueous electrolytic solution secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High temperature cycle test]
The non-aqueous electrolyte secondary battery of the laminate type cell was subjected to constant current-constant voltage charging up to 4.0 V at a current corresponding to 0.05 C in a thermostat at 25 ° C. Thereafter, it was discharged to 2.5 V at 0.05C. Subsequently, after CC-CV at 0.2 C to 4.0 V, the battery was discharged to 2.5 V at 0.2 C to stabilize the non-aqueous electrolyte secondary battery. Thereafter, CC-CV charging was performed at 0.2 C to 4.2 V, and then discharging was performed at 0.2 C to 2.5 V to perform initial conditioning.

The cell after the initial conditioning was charged in a 45 ° C. constant temperature bath at 0.5 C to CCCV charge to 4.2 V, and then discharged to 2.5 V at a constant current of 0.5 C as one cycle, for 100 cycles. The capacity at the 100th cycle is referred to as "capacity after 100 cycles". Moreover, after measuring the thickness of the battery which performed initial conditioning, the high temperature cycle test (100 cycles) was done. After that, the change in thickness of the battery was measured in the same manner as after the initial conditioning, and the change in electrode thickness of the battery with the cycle was regarded as "battery swelling".
In the following Table 1, Examples 1-1 to 1-6 and Comparative Examples 1-2 to 1-6 are the values of Comparative Example 1-1, and Examples 1-7 to 1-10 are Comparative Example 1-7. Indicated by the value of 100 cycle capacity, showing battery swelling.

<Comparative Examples 2-1 to 2-5>
[Production of positive electrode]
67.5 parts by mass of lithium manganate (Li _1.1 Mn _1.9 Al _0.1 O ₄ ) as a first positive electrode active material, lithium-nickel-cobalt-manganese composite oxidation as a second positive electrode active material 22.5 parts by mass of (Li _1.05 Ni _0.33 Mn _0.33 Co _0.33 O ₂ ), 5 parts by mass of carbon black as a conductive material, and 5 parts by mass of polyvinylidene fluoride (PVdF) as a binder % Was mixed and slurried with a disperser in N-methyl-2-pyrrolidone solvent. This was uniformly applied on both sides of a 21 μm thick aluminum foil and dried, and then pressed to form a positive electrode.

[Fabrication of negative electrode]
99.5 parts by mass of graphite powder as a negative electrode active material, 150 parts by mass of aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as a thickener and a binder, and aqueous of styrene-butadiene rubber 2 parts by mass of dispersion (concentration of 50% by mass of styrene-butadiene rubber) was added and mixed by a disperser to form a slurry. The slurry was uniformly coated on one side of a 10 μm thick copper foil and dried, and then pressed to form a negative electrode.

[Preparation of non-aqueous electrolyte solution]
The compound was added in the ratio of following Table 2 with respect to the whole reference electrolyte solution 2 shown by said <Example 1-1 to 1-10, Comparative Example 1-1 to 1-7>, and the electrolyte solution was prepared. . However, Comparative Example 2-5 is the reference electrolyte solution 2 itself.

[Manufacture of non-aqueous electrolyte battery (laminated type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained was wrapped with an aluminum laminate film, and after injecting an electrolytic solution described later, the battery element was vacuum sealed to produce a sheet-like non-aqueous electrolytic solution secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[Initial charge and discharge]
In a thermostat at 25 ° C., a sheet-like non-aqueous electrolyte secondary battery was charged by CC-CV to 4.2 V at 0.1 C and then discharged to 2.7 V at 0.1 C. Subsequently, CC-CV charge was performed at 0.3 C to 4.2 V, and then discharged at 0.3 C to 2.7 V. This was repeated 2 cycles for a total of 3 cycles to stabilize the non-aqueous electrolyte secondary battery. Thereafter, the battery was kept at 60 ° C. for 24 hours for aging.

[High temperature cycle test]
The high temperature cycle test was carried out for 100 cycles, where CC-CV was charged to 4.2 V at 1 C in a thermostat at 55 ° C. and then discharged to 2.7 V at 1 C CC. The ratio of the capacity of a 100-cycle house to the capacity of the first cycle was taken as "100-cycle capacity".
Table 2 below shows the 100 cycle capacity normalized with the value of Comparative Example 2-5.

<Reference Examples 1-1 to 1-4>
[Production of positive electrode]
85% by mass of lithium-nickel-cobalt-manganese composite oxide (Li _1.05 Ni _0.33 Mn _0.33 Co _0.33 O ₂ ) as a positive electrode active material and 10% by mass of acetylene black as a conductive material 5% by mass of polyvinylidene fluoride (PVdF) as a bonding material was mixed in an N-methylpyrrolidone solvent with a disperser to form a slurry. This was uniformly applied on both sides of a 21 μm thick aluminum foil and dried, and then pressed to form a positive electrode.

[Fabrication of negative electrode]
Silicon powder as a negative electrode active material, graphite powder as a conductive agent, and a binder were mixed, an N-methyl pyrrolidone solution was added to these, and they were mixed by a disperser to make a slurry. The obtained slurry was uniformly applied on a 20 μm thick copper foil as a negative electrode current collector to form a negative electrode, and the active material was cut out to have a width of 30 mm and a length of 40 mm to obtain a negative electrode. The negative electrode was used after drying under reduced pressure at 60 ° C. for 12 hours.

[Preparation of non-aqueous electrolyte solution]
1 mole / L of LiPF 6 sufficiently dried in a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) (volume ratio 3: 7) under a dry argon atmosphere (as a concentration in the non-aqueous electrolyte) What was made to melt | dissolve (this is called the reference electrolyte solution 1), and 2.0 mass% of vinylene carbonate (VC) and fluoro ethylene carbonate (MFEC) were respectively added (this is called the reference electrolyte solution 2). In the reference examples 1-1 to 1-2, the compounds described in the following Table 3 are added to the whole of the reference electrolyte 2 and in the reference examples 1-3 to 1-4, to the whole of the reference electrolyte 1. An electrolyte was prepared. However, Reference Example 1-1 and Reference Example 1-3 are the reference electrolyte solution 2 and the reference electrolyte solution 1 respectively.

[Manufacture of non-aqueous electrolyte battery (laminated type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained was wrapped with an aluminum laminate film, and after injecting an electrolytic solution described later, the battery element was vacuum sealed to produce a sheet-like non-aqueous electrolytic solution secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High temperature cycle test]
The non-aqueous electrolyte secondary battery of the laminate type cell was subjected to constant current-constant voltage charging up to 4.0 V at a current corresponding to 0.05 C in a thermostat at 25 ° C. Thereafter, it was discharged to 2.5 V at 0.05C. Subsequently, after CC-CV at 0.2 C to 4.0 V, the battery was discharged to 2.5 V at 0.2 C to stabilize the non-aqueous electrolyte secondary battery. Thereafter, CC-CV charging was performed at 0.2 C to 4.2 V, and then discharging was performed at 0.2 C to 2.5 V to perform initial conditioning.

  The cell after the initial conditioning was charged in a 45 ° C. constant temperature bath at 0.5 C to CCCV charge to 4.2 V, and then discharged to 2.5 V at a constant current of 0.5 C as one cycle, for 100 cycles. The capacity at the 100th cycle is referred to as "capacity after 100 cycles". Moreover, after measuring the thickness of the battery which performed initial conditioning, the high temperature cycle test (100 cycles) was done. After that, the change in thickness of the battery was measured in the same manner as after the initial conditioning, and the change in electrode thickness of the battery with the cycle was regarded as "battery swelling".

  In Table 3 below, Reference Example 1-2 shows the value of Reference Example 1-1, and Reference Example 1-4 shows the 100 cycle capacity and battery swelling normalized with the value of Reference Example 1-3.

  As apparent from Table 1, a non-aqueous system using a negative electrode active material containing metal particles capable of alloying with Li and graphite particles for the negative electrode and containing the specific substance represented by the general formula (A) of the present invention When an electrolytic solution is used, it has been shown to improve cycle characteristics and battery swelling more than Comparative Examples 1-2 to 1-6 which do not contain a specific compound. Further, as apparent from Tables 2 and 3, it is shown that the cycle characteristics and the battery swelling are not improved when the negative electrode active material containing metal particles capable of alloying with Li and graphite particles is not used for the negative electrode. There is. From this, a non-aqueous system in which a negative electrode active material containing metal particles capable of alloying with Li and graphite particles is used for the negative electrode and a compound having a structure represented by the general formula (A) is added to the non-aqueous electrolyte It is understood that cycle characteristics and battery swelling are improved by using the electrolytic solution.

  According to the non-aqueous electrolyte solution of the present invention, it is possible to improve capacity deterioration and cycle characteristics during high-temperature storage of the non-aqueous electrolyte battery. Therefore, it can be suitably used in all fields such as electronic devices in which non-aqueous electrolyte secondary batteries are used. Moreover, it can utilize suitably also in electric field capacitors, such as a lithium ion capacitor which uses a non-aqueous electrolyte solution.

  The application of the non-aqueous electrolytic solution and the non-aqueous electrolytic solution secondary battery of the present invention is not particularly limited, and can be used for various known applications. Specific examples of its use are laptop computers, e-book players, mobile phones, mobile faxes, mobile copiers, mobile printers, mobile audio players, small video cameras, LCD TVs, handy cleaners, transceivers, electronic organizers, calculators, memories Cards, portable tape recorders, radios, backup power supplies, automobiles, motorbikes, motorbikes, bicycles, lighting fixtures, toys, game machines, watches, electric tools, strobes, cameras, etc. can be mentioned.

Claims (6)

1. A non-aqueous electrolyte secondary battery comprising a positive electrode and a negative electrode capable of inserting and extracting metal ions, and a non-aqueous electrolyte solution, the non-aqueous electrolyte solution comprising an electrolyte and a non-aqueous solvent together with the general formula (A) contains a compound represented by), and, have a negative active material negative electrode containing Li can be alloyed metal particles and graphite particles, with said Li can be alloyed metal particles and the graphite particles The L to the sum of
The content of the metal particle which can be alloyed with i is 0.1-25 mass%, The non-aqueous electrolyte solution secondary battery characterized by the above-mentioned.

(R ¹ and R ² independently represent an alkyl group, an alkenyl group, an alkynyl group, or an aromatic hydrocarbon group which may be substituted with a halogen atom. X ¹ and X ² are independently hydrogen An atom, a halogen atom, an alkoxycarbonyl group which may be substituted by a halogen atom, or an acyl group is shown, n is an integer of 0 to 1, provided that when n = 0, R2 is an alkyl substituted by a halogen atom Group, an alkenyl group, an alkynyl group, or an aromatic hydrocarbon group is shown) In the non-aqueous electrolyte solution, the content of the compound represented by the general formula (A) is 0.001% by mass to 10% by mass with respect to the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte secondary battery as described in. The non-aqueous electrolyte comprises a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, an acid anhydride compound, an isocyanate compound, a cyclic sulfonic acid ester compound, a compound having an isocyanuric acid skeleton and a nitrile compound. The non-aqueous electrolytic solution secondary battery according to claim 1, containing at least one compound selected from the group. In the non-aqueous electrolyte, a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, an acid anhydride compound, an isocyanate compound, a cyclic sulfonic acid ester compound, a compound having an isocyanuric acid skeleton and a cyano group The content of the at least one compound selected from the group consisting of compounds is 0. 0 to the total amount of the non-aqueous electrolyte solution.
It is 001 mass% or more and 10 mass% or less, The non-aqueous electrolyte according to claim 3
Secondary battery. The metal particle that can be alloyed with Li is at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn and W, or a metal compound thereof. 4. The non-aqueous electrolyte secondary battery according to any one of 4. The non-aqueous electrolyte secondary battery according to any one of claims 1 to 5, wherein the metal particle that can be alloyed with Li is Si or a metal oxide with Si.