KR20120094003A - Binder particles for electrochemical element - Google Patents

Abstract

(Problem) Provided is a binder for an electrochemical device which does not contain a component decomposed at a potential at which lithium is inserted into a negative electrode active material and which does not increase internal resistance and is excellent in output characteristics and life characteristics.
(Measures) The binder particle for electrochemical elements which concerns on this invention consists of a core part and a cell part, the cell part contains the monomer unit containing the atom which has an isolated electron pair, and the said valence is quaternized with the organic acid, It consists of a polymer which consists of.

Description

Binder particles for electrochemical devices {BINDER PARTICLES FOR ELECTROCHEMICAL ELEMENT}

The present invention provides binder particles used for the production of electrodes (hereinafter, collectively referred to as "electrochemical element electrodes") used in electrochemical elements such as lithium ion secondary batteries and electric double layer capacitors, emulsions thereof, and It relates to a slurry composition for an electrochemical device electrode.

Taking advantage of the characteristics of small size, light weight, high energy density, and repeatable charging and discharging, electrochemical devices such as lithium ion secondary batteries, electric double layer capacitors, and lithium ion capacitors are rapidly expanding their demands. Lithium ion secondary batteries are used in fields such as mobile phones and notebook personal computers because of their relatively high energy density. In addition, since the electric double layer capacitor can be rapidly charged and discharged, it is used as a memory backup small power supply such as a personal computer. In addition, the electric double layer capacitor is expected to be applied as a large power source for electric vehicles. In addition, hybrid capacitors utilizing the advantages of lithium ion secondary batteries and electric double layer capacitors have attracted attention in that both energy density and output density are high.

The electrode of these electrochemical elements consists of an electrode active material layer carried by the electrical power collector. The electrode active material layer contains a dispersion medium such as an electrode active material, a binder resin, and water, and is formed by applying and drying a slurry of an electrode composition containing a conductive material, a dispersant, a surfactant, a viscosity modifier, etc. to a current collector, as necessary. Each of these components affects the properties of the electrochemical device, but in particular, the binder has a relatively high volume ratio in the electrode composition, and greatly affects the performance of the electrochemical device.

The binder usually used is a fine particle of an elastomer. The fine particles of such an elastomer are generally obtained by emulsion polymerization using a low molecular weight surfactant (Patent Document 1). For this reason, surfactant is contained in the elastic polymer obtained.

Japanese Unexamined Patent Publication No. 10-302797

However, a low molecular weight surfactant may decompose when exposed to repeated charge and discharge in an electrochemical device, especially when the potential during charge and discharge is high. For this reason, when an elastomer containing a surfactant is used as binder particles for an electrochemical device, foreign substances due to decomposition products of the surfactant are generated at a potential at which lithium is inserted into the negative electrode active material. In some cases, an increase in internal resistance and a decrease in battery life may be caused. On the other hand, when the amount of the surfactant is reduced or the amount of the surfactant is reduced by water washing or the like after emulsion polymerization, the dispersion stability of the elastomer may be lowered and aggregated to coarsen.

In addition, when an electrode active material having a relatively high pH is used as the electrode active material, as a result of corroding the current collector to generate gas, pinholes or the like may occur on the electrode surface.

Therefore, the present invention does not include a component that decomposes at the potential at which lithium is inserted into the negative electrode active material, and does not increase the internal resistance, so that the electrode active material is excellent even if the electrode active material having excellent output characteristics and lifespan characteristics and high pH is used. An object of the present invention is to provide a binder for an electrochemical device capable of suppressing the generation of pinholes on the surface.

The present invention solving the above problems includes the following matters as a summary.

(1) consisting of a core part and a cell part,

Binder particle | grains for electrochemical elements which consist of a polymer in which a cell part contains the atom unit containing the atom which has an lone electron pair, and the said atom is quaternized with the organic acid.

(2) The binder particle for electrochemical elements as described in (1) whose weight average molecular weights of the said polymer are 5,000-100,000.

(3) The polymer which comprises a cell part quaternized cationic by the organic acid the atom which has the isolated electron pair of the polymer containing the atom which has an isolated electron pair,

The binder particle | grains for electrochemical elements as described in (1) or (2) whose usage-amount of the organic acid used for the said quaternization cationization is 0.5-2.0 mol with respect to 1 mol of atoms which have the said isolated electron pair.

(4) The electrochemical device according to any one of (1) to (3), wherein the polymer forming the core portion is an elastic polymer, and the elastic polymer is any of a fluorine polymer, a diene polymer, and an acrylate polymer. Binder particles.

(5) The binder composition for electrochemical elements in which the binder particle for electrochemical elements in any one of said (1)-(4) is disperse | distributed to a dispersion medium.

(6) The binder composition for electrochemical elements according to the above (5), wherein the dispersion medium is water.

(7) The slurry composition for electrochemical element electrodes containing the binder particle for electrochemical elements in any one of said (1)-(4), an electrode active material, and a dispersion medium.

(8) The electrochemical element electrode manufactured by apply | coating and drying the slurry composition for electrochemical element electrodes as described in said (7) to an electrical power collector.

(9) The electrochemical element which has an electrode as described in said (8).

(10) Process of superposing | polymerizing the polymeric composition containing the monomer containing the atom which has an isolated electron pair, and obtaining the polymer (I) containing the atom which has an isolated electron pair,

A step of quaternizing an atom having an isolated electron pair contained in the polymer (I) with an organic acid to obtain a polymer (II), and

The manufacturing method of the binder particle for electrochemical elements as described in said (1) containing the process of manufacturing an elastic polymer in presence of a polymer (II).

The binder particle for electrochemical elements which concerns on this invention does not contain the component which decomposes even if it is repeatedly exposed to high electric potential, for example, surfactant. Therefore, according to the electrochemical element using the binder particle for electrochemical elements of this invention, the lifetime of an element can be extended. Moreover, although the binder particle | grains for electrochemical elements of this invention show the outstanding dispersion stability, even if it does not contain surfactant, even if it uses what pH becomes high when preparing slurry for electrodes, such as Ni containing compound, as an electrode active material, A plate having a smooth surface can be obtained.

(Binder Particles for Electrochemical Devices)

The binder particle for electrochemical elements which concerns on this invention has what is called a core cell structure which consists of a core part and a cell part.

It is preferable that the polymer which forms a core part is an elastic polymer, and the said elastic polymer is any of a fluoropolymer, a diene polymer, and an acrylate polymer. An elastomer is defined as having an elastic modulus (Young's modulus) at room temperature of about 1-10 MPa (JIS K 6251). When the polymer forming the core portion is the polymer, an electrode plate excellent in flexibility and adhesion strength can be obtained. Among the elastomers, the diene polymer or the acrylate polymer is more preferable because it can increase the withstand voltage and can increase the energy density of the electrochemical device, and the acrylate polymer is particularly preferred. Do.

A diene polymer is a polymer containing the monomeric unit formed by polymerizing conjugated dienes, such as butadiene and isoprene. The ratio of the monomer unit formed by superposing | polymerizing the conjugated diene in a diene type polymer is 40 weight% or more normally, Preferably it is 50 weight% or more, More preferably, it is 60 weight% or more. As a diene polymer, the homopolymer of conjugated dienes, such as polybutadiene and polyisoprene; The copolymer of the monomer copolymerizable with conjugated diene is mentioned. As said monomer which can be copolymerized, (alpha), (beta)-unsaturated nitrile compounds, such as acrylonitrile and methacrylonitrile; styrene, chloro styrene, vinyltoluene, t-butyl styrene, vinyl benzoic acid, methyl vinyl benzoate, vinyl naphthalene, chloro Styrene-based monomers such as methyl styrene, hydroxymethyl styrene, α-methyl styrene and divinylbenzene; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; olefins such as ethylene and propylene; vinyl chloride and vinylidene chloride. Halogen atom-containing monomers; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether and butyl vinyl ether; methyl vinyl ketone, ethyl vinyl ketone, and butyl vinyl ketone Vinyl ketones such as hexyl vinyl ketone and isopropenyl vinyl ketone; heterocycles such as N-vinylpyrrolidone, vinyl pyridine and vinylimidazole; A containing vinyl compound is mentioned. Among these, α, β-unsaturated nitrile compounds, styrene monomers and unsaturated carboxylic acids are preferable. 5-60 weight% is preferable and, as for the ratio of the structural unit derived from these copolymerizable monomers, 10-50 weight% is more preferable.

An acrylate polymer is a polymer containing the monomeric unit formed by superposing | polymerizing an acrylic acid ester and / or methacrylic acid ester. The ratio of the monomer unit formed by superposing | polymerizing the acrylic acid ester and / or methacrylic acid ester in an acrylic polymer is 40 weight% or more normally, Preferably it is 50 weight% or more, More preferably, it is 60 weight% or more. As an acryl-type polymer, the homopolymer of acrylic acid ester and / or methacrylic acid ester, the copolymer of acrylic acid ester and / or methacrylic acid ester, and the monomer copolymerizable with this is mentioned. Examples of the copolymerizable monomer include carboxylic acid ester monomers having two or more carbon-carbon double bonds such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate and trimethylolpropane triacrylate; styrene and chlorostyrene Styrene monomers such as vinyltoluene, t-butyl styrene, vinyl benzoic acid, methyl vinyl benzoate, vinyl naphthalene, chloromethyl styrene, hydroxymethyl styrene, α-methyl styrene and divinylbenzene; unsaturated such as acrylic acid and methacrylic acid; Carboxylic acid; Amide system monomers, such as acrylamide, N-methylol acylamide, and acrylamide-2-methylpropanesulfonic acid; (alpha), (beta)-unsaturated nitrile compounds, such as acrylonitrile and methacrylonitrile; Ethylene, Olefins such as propylene; diene monomers such as butadiene and isoprene; halogen atom-containing mothers such as vinyl chloride and vinylidene chloride Nomer; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether and butyl vinyl ether; methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone and hexyl vinyl Vinyl ketones such as ketones and isopropenyl vinyl ketones; and heterocyclic vinyl compounds such as N-vinylpyrrolidone, vinylpyridine and vinylimidazole. Among these, α, β-unsaturated nitrile compounds and styrene monomers are preferable, and α, β-unsaturated nitrile compounds are particularly preferable. 3-60 weight% is preferable, as for the ratio of the structural unit derived from these copolymerizable monomers, 5-50 weight% is more preferable, 5-30 weight% is especially preferable.

In this invention, it is preferable that the glass transition temperature of an elastomer is 25 degrees C or less, More preferably, it is -100 degreeC-+25 degreeC, More preferably, it is -80 degreeC-+10 degreeC, Most preferably, it is -80 degreeC-0 ℃. When the glass transition temperature of the elastomer is in the above range, properties such as flexibility, binding and winding properties, adhesion between the electrode active material layer and the current collector layer are highly balanced, and the surface of the electrode active material particles is coated on the binder. Since the present state can be maintained, peeling of the binder from the electrode active material in the electrode plate pressing step can be suppressed, and a decrease in the adhesion strength can be suppressed.

These elastic polymers can be used individually or in combination of 2 or more types.

The cell portion contains a monomer unit containing an atom having an lone pair of electrons, and further comprises a polymer in which the atom is quaternized with an organic acid (hereinafter, referred to as "quaternary polymer").

As an atom which has an lone pair, nitrogen, sulfur, oxygen, fluorine, phosphorus, etc. are mentioned, for example, Among these, nitrogen and sulfur are more preferable at the point of versatility and workability, Especially, nitrogen is the most preferable.

Therefore, as a monomer unit containing the atom which has a lone electron pair, the monomer unit derived from the (alpha), (beta) ethylenic polymerizable compound which has an amino group is mentioned, for example. Specific examples of the amino group-containing α, β ethylenic polymerizable compound include dimethylaminomethyl acrylate, diethylaminomethyl acrylate, dibutylaminomethyl acrylate, dihexylaminomethyl acrylate, and dimethylaminoethyl acrylate. Corresponding to acrylates such as ethylaminoethyl acrylate, di (t-butyl) aminoethyl acrylate, diisohexylaminoethyl acrylate, dihexylaminopropyl acrylate, di (t-butyl) aminohexyl acrylate Methacrylates and the like.

Moreover, aromatic monomers containing nitrogen, such as 2-vinylpyridine, etc. are mentioned.

The monomer containing the atom which has these lone electron pairs may be used independently, or may be used in a complex system.

Moreover, the quaternization polymer may contain the unit derived from the other monomer copolymerizable with the monomer containing the atom which has a lone electron pair.

The other copolymerizable monomer is preferably an α, β ethylenic polymerizable compound having an organic acid group. For example, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, acrylamide-2-methylpropanesulfonic acid Methacrylates corresponding to acrylates such as these are included. These may be used alone or in combination.

The other monomers other than the above are preferably α, β ethylenic polymerizable compounds having no organic acid group and amino group, for example, alkyl or cycloalkyl esters of acrylic acid or methacrylic acid, ethylene glycol dimethacrylate, Carboxylic ester monomers having two or more carbon-carbon double bonds such as diethylene glycol dimethacrylate and trimethylolpropane triacrylate; styrene, chlorostyrene, vinyltoluene, t-butylstyrene, vinyl benzoic acid, vinyl benzoic acid Styrene-based monomers such as methyl, vinylnaphthalene, chloromethylstyrene, hydroxymethylstyrene, α-methylstyrene and divinylbenzene; Amides such as acrylamide, N-methylol acrylamide and acrylamide-2-methylpropanesulfonic acid. Monomer; α, β-unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile; ol such as ethylene and propylene Lepins; diene monomers such as butadiene and isoprene; halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate; methyl vinyl ether, ethyl vinyl ether, Vinyl ethers such as butyl vinyl ether; vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone, and isopropenyl vinyl ketone; N-vinyl pyrrolidone, vinyl pyridine, vinyl imidazole, and the like. Heterocyclic containing vinyl compound is mentioned. These may be used alone or in combination.

In the quaternization polymer, the ratio of the monomer unit containing the atom having the lone electron pair to another monomer unit is not particularly limited, but the content of the monomer unit containing the atom having the lone electron pair is based on the total constitutional units of the polymer. Preferably it is 20 to 90 weight%, More preferably, it is 30 to 80 weight%, Especially preferably, it is 40 to 70 weight%, Most preferably, it is in the range of 40 to 50 weight%. By including a monomer unit containing an atom having an isolated electron pair in the polymer in the above range, it is possible to efficiently present a cationic functional group on the cell portion of the binder, that is, the surface thereof, and this cationic functional group allows the lithium inside the battery. It becomes possible to reduce the transfer resistance of ions, and the water solubility and output characteristics of lithium ions are improved.

As described above, the quaternization polymer includes a monomer unit containing an atom having an isolated electron pair, and the atom is quaternized with an organic acid. By using an organic acid for quaternization, it is easy to produce a favorable film between functional groups on the surface of an electrical power collector, and corrosion of an electrical power collector can be suppressed. Moreover, even when the electrode active material with high pH is used, generation | occurrence | production of the pinhole in the electrode surface can be suppressed.

Examples of the organic acid include those selected from the group consisting of carboxylic acid, sulfonic acid, and phosphonic acid.

Examples of the carboxylic acid include aliphatic saturated carboxylic acids such as acetic acid, butyric acid, pivalic acid, 2-ethylhexanoic acid, caproic acid, caprylic acid, capric acid, lauric acid, palmitic acid and stearic acid; Aliphatic unsaturated carboxylic acids such as methacrylic acid, crotonic acid, sorbic acid, oleic acid, euicosapentaenoic acid, docosahexaenoic acid; aromatic carboxylic acids such as benzoic acid and cinnamic acid; further, monochloroacetic acid, salicylic acid, etc. Carboxylic acid derivatives; Polyhydric carboxylic acids, such as succinic acid, glutaric acid, adipic acid, isophthalic acid, terephthalic acid, etc. are mentioned.

As sulfonic acid, 2, 4- dichloro benzene sulfonic acid, 2, 5- dichloro benzene sulfonic acid, 3, 5- dichloro benzene sulfonic acid, 2, 4- dibromo benzene sulfonic acid, 2, 5- dibromo benzene sulfonic acid, 3, 5-dibromobenzenesulfonic acid, 2,4-diiodinebenzenesulfonic acid, 2,5-diiodinebenzenesulfonic acid, 3,5-diiodinebenzenesulfonic acid, 2,4-dichloro-5-methylbenzenesulfonic acid, 2,5 -Dichloro-4-methylbenzenesulfonic acid, 2,4-dibromo-5-methylbenzenesulfonic acid, 2,5-dibromo-4-methylbenzenesulfonic acid, 2,4-diiodine-5-methylbenzenesulfonic acid, 2,5-diiodine-4-methylbenzenesulfonic acid, 2,4-dichloro-5-methoxybenzenesulfonic acid, 2,5-dichloro-4-methoxybenzenesulfonic acid, 2,4-dibromo-5-meth Methoxybenzenesulfonic acid, 2,5-dibromo-4-methoxybenzenesulfonic acid, 2,4-diiodine-5-methoxybenzenesulfonic acid, 2,5-diiodine-4-methoxybenzenesulfonic acid, 3,3 '-Dichlorobiphenyl-2,2'-disulfonic acid, 3,3'-dibromobiphenyl-2,2'-disulfonic acid, 3,3'-diiobibiphenyl-2,2'-disulfonic acid, 4,4'-dichlorobipe Nyl-2,2'-disulfonic acid, 4,4'-dibromobiphenyl-2,2'-disulfonic acid, 4,4'-diiodbiphenyl-2,2'-disulfonic acid, 4,4 ' -Dichlorobiphenyl-3,3'-disulfonic acid, 4,4'-dibromobiphenyl-3,3'-disulfonic acid, 4,4'-diiodbiphenyl-3,3'-disulfonic acid, 5 , 5'-dichlorobiphenyl-2,2'-disulfonic acid, 5,5'-dibromobiphenyl 2,2'-disulfonic acid, 5,5'-diiobibiphenyl-2,2'-disulfonic acid Etc. can be mentioned.

Examples of the phosphonic acid include 1-hydroxyethylidene-1,1-diphosphonic acid, 1-hydroxypropylidene-1,1-diphosphonic acid and 1-hydroxybutylidene-1,1-diphosphone Acid, aminotrimethylenephosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, methyldiphosphonic acid, nitrotrismethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, ethylenediaminebismethylenephosphonic acid, Amino tris methylene phosphonic acid, hexamethylene diamine tetramethylene phosphonic acid, diethylene triamine pentamethylene phosphonic acid, and cyclohexanediamine tetramethylene phosphonic acid are mentioned.

Among these, phosphonic acid is preferable, the phosphonic acid containing a nitrogen atom is more preferable at the point which the corrosion prevention effect of an electrical power collector becomes more remarkable, and nitrotris methylene phosphonic acid is especially preferable.

In the quaternization polymer, the atoms having lone electron pairs may be quaternized in their entirety, and some of them may be quaternized. The ratio of quaternization is not particularly limited, but is preferably 0.5 to 2.0 moles, more preferably 0.7 to 1.8 moles, and particularly preferably 0.8 to 1.5 moles of organic acid per mole of atoms having lone pairs. It is preferable to make it quaternize by making it react as a rapid supply agent.

If quaternization is insufficient, the above-described effect of reducing the transfer resistance of lithium ions is not sufficiently obtained. If the quaternization is excessive, the acid remaining in the system lowers the pH of the system at the time of slurry production described later, and the electrostatic repulsion effect of the electrode active material particles is inhibited, resulting in a problem that the dispersibility of the slurry is lowered.

The weight average molecular weight of the quaternization polymer which comprises a cell part becomes like this. Preferably it is 5,000-100,000, More preferably, it is 7,500-50,000, Especially preferably, it is the range of 10,000-25,000. Since the molecular weight of a quaternization polymer exists in the said range, reaction advances easily at the time of superposition | polymerization of a core part.

Glass transition temperature Tg of the quaternization polymer which comprises a cell part becomes like this. Preferably it is 50 degrees C or less, More preferably, it is -15-25 degreeC. If the glass transition temperature (Tg) of the quaternized polymer is in this range, the binding property is excellent in a small amount of use, the electrode strength is strong, and the flexibility is abundant, and the electrode density is easily increased by the press process at the time of electrode formation. Can be.

The binder particle | grains for electrochemical elements of this invention are formed from the core part which consists of said elastic polymers, and the cell part which consists of quaternization polymers. Although the ratio of a core part and a cell part is not specifically limited, A core part / cell part by weight ratio becomes like this. Preferably it is 10/90-90/10, More preferably, it is 20/80-80/20, Especially preferably, it is 30/70 It is in the range of 70/30. Since the ratio of a core part and a cell part exists in the said range, the effect of reducing the movement resistance of lithium ion is not impaired, and stability of binder particle | grains is maintained.

50 nm-500 nm are preferable, and, as for the number average particle diameter of the binder particle for electrochemical elements, 70 nm-400 nm are more preferable. If the number average particle diameter of a binder particle is this range, the intensity | strength and flexibility of the electrode obtained will become favorable.

Although the presence form of the binder particle for electrochemical elements which concerns on this invention as mentioned above is not specifically limited, As mentioned later, the binder particle for electrochemical elements of this invention is preferably obtained by emulsion polymerization, and is used for a dispersion medium. It is common for the binder particles to be in the form of dispersed emulsion.

(Dispersion medium)

The dispersion medium of the binder particles for electrochemical elements is not particularly limited as long as the binder particles are uniformly dispersed.

As a dispersion medium, both water and an organic solvent can be used. As an organic solvent, Cycloaliphatic hydrocarbons, such as cyclopentane and cyclohexane; Aromatic hydrocarbons, such as toluene, xylene, and ethylbenzene; Acetone, ethyl methyl ketone, diisopropyl ketone, cyclohexanone, methylcyclohexane, Ketones such as ethylcyclohexane; chlorine aliphatic hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride; esters such as ethyl acetate, butyl acetate, γ-butyrolactone and ε-caprolactone; acylonitrile such as acetonitrile and propionitrile Ethers such as tetrahydrofuran and ethylene glycol diethyl ether; alcohols such as methanol, ethanol, isopropanol, ethylene glycol and ethylene glycol monomethyl ether; N-methylpyrrolidone, N, N-dimethylformamide and the like; Amides may be mentioned.

These dispersion mediums may be used alone, or two or more thereof may be mixed and used as a mixed solvent. Among these, a dispersion medium having a low boiling point and high volatility is preferable because it can be removed in a short time and at a low temperature. Specifically, acetone, toluene, cyclohexanone, cyclopentane, tetrahydrofuran, cyclohexane, xylene, water, or N-methylpyrrolidone, or a mixed solvent thereof is preferable, and water is particularly preferable.

(Method for Producing Binder Particles for Electrochemical Devices)

Although the manufacturing method of the binder particle of this invention is not specifically limited, It can obtain easily from emulsion polymerization which made the said polymer the emulsifier.

That is, the manufacturing method of the binder particle of this invention,

Polymerizing a polymerizable composition containing a monomer containing an atom having an isolated electron pair, and obtaining a polymer (I) containing an atom having an isolated electron pair,

A step of quaternizing an atom having an isolated electron pair contained in the polymer (I) with an organic acid to obtain a polymer (II), and

It is characterized by including the process of manufacturing an elastic polymer in presence of polymer (II).

Specific examples of the monomer containing an atom having an isolated electron pair as a raw material of the polymer (I), and other comonomers, copolymerization ratios thereof and the like are the same as above. Although the polymerization method is not specifically limited, Polymer (I) can be obtained simply by solution polymerization.

Examples of the solvent that can be used for the solution polymerization include aromatics such as toluene and xylene; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; alcohols such as normal butanol, isobutanol and isopropyl alcohol; ethyl acetate And esters such as n-butyl acetate and the like. These may be used alone or in combination. Alcohols having good solubility of the polymer (I) are preferred.

Moreover, although the polymerization initiator for solution polymerization of polymer (I) is not specifically limited, Azo type polymerization initiators, such as azobisisobutyronitrile, peroxide type polymerization initiators, such as benzoyl peroxide, etc. are contained. These polymerization initiators may be used alone or in combination.

Although polymerization temperature is not specifically limited, Generally, it is 40-180 degreeC, Preferably it is about 60-150 degreeC, and polymerization time is 2-8 hours, Preferably it is about 3-6 hours.

By such solution polymerization, the polymer (I) containing the atom which has a lone electron pair can be obtained simply.

Subsequently, the above-mentioned polymer (II) is obtained by quaternizing the atom which has the lone electron pair contained in polymer (I). Here, the quaternizing agent to be used, the usage amount thereof, and the like are as described above.

Although the temperature at the time of quaternization is not specifically limited, Generally it is 25-80 degreeC, Preferably it is about 40-60 degreeC, and the time of a quaternization process is 1-5 hours, Preferably it is about 2-4 hours. to be.

Polymer (II) obtained in this way is said quaternization polymer, and all the characteristics are as above-mentioned.

Next, the binder particle for electrochemical elements of this invention is obtained by manufacturing the said elastic polymer in presence of the obtained polymer (II).

The elastomer is as described above, and the production method thereof is not particularly limited. However, since the binder particles of the core cell structure can be easily obtained, it is preferable to produce the elastomer by emulsion polymerization using the emulsification action of the polymer (II). .

What is necessary is just to set the specific manufacturing conditions of an elastic polymer suitably based on the target polymer composition.

Although not limited at all, a well-known redox polymerization initiator can be used as a polymerization initiator for emulsion polymerization, For example, hydrogen peroxide is contained. Moreover, it is preferable to perform emulsion polymerization at the temperature of 60-90 degreeC. The polymerization time is appropriately selected depending on the core / cell ratio described above, and is generally 2 to 10 hours, preferably 4 to 6 hours. Moreover, as a medium of emulsion polymerization, said dispersion medium is used, It is preferable to use water especially.

(Slurry Composition for Electrochemical Device Electrodes)

The slurry composition for electrochemical element electrodes which concerns on this invention is characterized by including the said binder particle and an electrode active material. Moreover, this slurry composition contains dispersion mediums, such as water, an electrically conductive material, a thickener, etc. as needed.

(Electrode active material)

An electrode active material is a substance which exchanges electrons in the electrode for electrochemical elements. The electrode active material mainly includes an active material for lithium ion secondary batteries, an active material for electric double layer capacitors, and an active material for lithium ion capacitors.

The electrode active material (positive electrode active material) for a lithium ion secondary battery positive electrode is largely divided into the thing which consists of inorganic compounds and the thing which consists of organic compounds, and the active material which can occlude-release lithium ion.

As a positive electrode active material which consists of inorganic compounds, transition metal oxide, transition metal sulfide, lithium containing composite metal oxide of lithium and a transition metal, etc. are mentioned. As the transition metal, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo and the like are used.

As the transition metal oxide, MnO, MnO ₂ , V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , Cu ₂ V ₂ O ₃ , amorphous V ₂ OP ₂ O ₅ , MoO ₃ , V ₂ O ₅ , V ₆ O It includes _13, etc., and among them are preferable _{MnO, V 2 O 5, V} 6 O 13, TiO 2 from the cycle stability and capacity.

Examples of the transition metal sulfides include TiS ₂ , TiS ₃ , amorphous MoS ₂ , FeS, and the like.

As a lithium containing composite metal oxide, the lithium containing composite metal oxide which has a layered structure, the lithium containing composite metal oxide which has a spinel structure, the lithium containing composite metal oxide which has an olivine type structure, etc. are mentioned.

Lithium-containing composite metal oxides having a layered structure include lithium-containing cobalt oxide (LiCoO ₂ ), lithium-containing nickel oxide (LiNiO ₂ ), lithium composite oxide of Co-Ni-Mn, lithium composite oxide of Ni-Mn-Al, Ni And lithium composite oxides of -Co-Al.

A lithium-containing composite metal oxide having a spinel structure lithium manganese oxide (LiMn ₂ O ₄₎ and the substituting a part of Mn with other transition metal _{Li [Mn 3/2 M 1} /2] O 4 ( where M, Cr , Fe, Co, Ni, Cu and the like).

Examples of the lithium-containing composite metal oxide having an olivine-type structure include Li _X MPO ₄ (wherein M is Mn, Fe, Co, Ni, Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, and Si). And an olivine-type lithium phosphate compound represented by at least one selected from B, and Mo, 0 ≦ X ≦ 2).

As the organic compound, for example, a conductive polymer such as polyacetylene or poly-p-phenylene may be used.

The iron oxide lacking in electrical conductivity may be used as an electrode active material covered with a carbon material by allowing a carbon source material to be present during reduction firing. Moreover, these compounds may be element substituted partially. The mixture of the said inorganic compound and an organic compound may be sufficient as the positive electrode active material for lithium ion secondary batteries.

As the electrode active material (negative electrode active material) for the lithium ion secondary battery negative electrode, an active material capable of occluding and releasing lithium ions is used, and is mainly classified into a carbon-based active material and a non-carbon-based active material.

Examples of the carbon-based active material include carbonaceous materials and graphite materials. Carbonaceous material generally refers to a low graphitization (low crystallinity) carbon material heat-treated (carbonized) the carbon precursor at 2000 ° C. or lower, and graphite material refers to heat treatment at 2000 ° C. The graphite material which has high crystallinity close to the obtained graphite is shown.

Examples of the carbonaceous material include non-graphitizable carbon having a structure close to an amorphous structure represented by digraphite carbon and glassy carbon, which easily change the structure of the carbon depending on the heat treatment temperature. Examples of the digraphite carbon include carbon materials based on tar pitch obtained from petroleum or coal, and include, for example, coke, mesocarbon microbeads (MCMB), mesophase pitch carbon fiber, pyrolysis vapor growth carbon fiber, and the like. Can be mentioned. MCMB is carbon microparticles | fine-particles which isolate | separated and extracted the mesophase globules produced | generated in the process of heating pitch about 400 degreeC, and mesophase pitch type carbon fiber is the mesophase pitch obtained by the growth and coalescing of the said mesophase globules. It is carbon fiber made into.

Examples of the non-graphite carbon include phenol resin fired bodies, polyacrylonitrile-based carbon fibers, pseudo isotropic carbon, and furfuryl alcohol resin fired bodies (PFA).

Examples of the graphite material include natural graphite and artificial graphite. Examples of artificial graphite include artificial graphite heat treated at 2800 ° C. or higher, graphitized MCMB obtained by heat treating MCMB at 2000 ° C. or higher, and graphitized mesophase pitch carbon fiber heat treated at 2000 ° C. or higher. It is used as a negative electrode active material.

As the non-carbon-based active material, lithium metals, single metals and alloys forming a lithium alloy, and oxides and sulfides thereof are used.

As a single metal and alloy which form a lithium alloy, the compound containing metals, such as Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn, Sr, Zn, etc. Can be mentioned. Among them, a single metal of silicon (Si), tin (Sn) or lead (Pb), an alloy containing these atoms, or a compound of these metals is used.

Examples of the oxides and sulfides include oxides, carbides, nitrides, silicides, sulfides, and phosphides. Among them, a lithium-containing metal composite oxide material containing a metal element selected from the group consisting of oxides such as tin oxide, manganese oxide, titanium oxide, niobium oxide, vanadium oxide, Si, Sn, Pb, and Ti atoms is used.

As the lithium-containing metal composite oxide, a lithium titanium composite oxide further represented by Li _x Ti _y M _z O ₄ (0.7 ≦ x ≦ 1.5, 1.5 ≦ _y ≦ 2.3, 0 ≦ _z ≦ 1.6, and M is Na, K, Co , Al, Fe, Ti, Mg , Cr, Ga, Cu, Zn , and can be exemplified by Nb), in particular, _{Li 4/3 Ti 5/3} O 4, Li 1 Ti 2 O 4, Li 4/5 Ti 11 _{/ 5} O ₄ is used.

The volume average particle diameter of the active material for lithium ion secondary battery electrodes is 1-50 micrometers normally, Preferably it is 2-30 micrometers. By having a particle diameter in the said range, it is possible to reduce the amount of binder at the time of preparing the slurry composition mentioned later, to suppress the fall of a battery capacity, and to prepare with a viscosity suitable for apply | coating a slurry composition. It becomes easy and a uniform electrode can be obtained.

Moreover, as an active material for lithium ion secondary battery electrodes, what adhere | attached the electrically conductive provision material to the surface by a mechanical modification method can also be used.

As an electrode active material used for the electrode for electric double layer capacitors, a carbon allotrope is used normally. Specific examples of the allotrope of carbon include activated carbon, polyacene, carbon whisker, graphite, and the like, and these powders or fibers can be used. Preferable electrode active materials are activated carbon, and specific examples thereof include activated charcoal obtained from phenol resin, rayon, acrylonitrile resin, pitch, and coconut shell.

The volume average particle diameter of the electrode active material used for the electrode for electric double layer capacitors is 0.1-100 micrometers normally, Preferably it is 1-50 micrometers, More preferably, it is 5-20 micrometers.

The specific surface area of the electrode active material used for the electrode for electric double layer capacitors is 30 m <2> / g or more, Preferably it is 500-5,000 m <2> / g, More preferably, it is 1,000-3,000 m <2> / g. Since the density of the electrode active material layer obtained tends to become small, so that the specific surface area of an electrode active material is large, the electrode active material layer which has a desired density can be obtained by selecting an electrode active material suitably.

(Slurry Composition for Electrodes for Electrochemical Devices)

The slurry composition for electrodes for electrochemical elements of this invention contains said electrode active material, the binder particle for electrochemical elements of this invention, and a dispersion medium.

The binder particle for electrochemical elements may be a mixture of two or more kinds of binder particles having different structures or compositions within a range not impairing the object of the present invention. Moreover, the normal binder particle which does not have a core cell structure may be contained. That is, 0.5 weight part or more of binder particles for electrochemical elements of this invention should just be contained with respect to 100 weight part of whole amounts of binder particle.

The amount of the binder particles is usually 0.1 to 50 parts by weight, preferably 0.5 to 20 parts by weight, more preferably 1 to 10 parts by weight, and particularly preferably 1 to 5 parts by weight with respect to 100 parts by weight of the electrode active material. to be. When the amount of the binder particles is within this range, the adhesion between the electrode active material layer and the current collector obtained can be sufficiently secured, and the capacity of the electrochemical element can be increased and the internal resistance can be lowered.

For example, the binder particles may be in a state in which binder particles such as latex are dispersed in water or may be in a powder form obtained by drying such a dispersion liquid.Binder particles are dispersed in water from the viewpoint of reducing environmental load. The form of the aqueous emulsion is preferred.

The slurry composition for electrochemical element electrodes of this invention makes the said component essential, and contains a dispersion medium, a electrically conductive material, a thickener, etc. as needed.

(Dispersion medium)

As a dispersion medium used in order to obtain a slurry, although water is used normally similarly to the emulsion of the binder for electrochemical elements mentioned above, as long as the dispersion state of each said component is maintained, you may use an organic solvent. As an organic solvent, For example, alkyl alcohols, such as methyl alcohol, ethyl alcohol, and propyl alcohol; alkyl ketones, such as acetone and methyl ethyl ketone; ethers, such as tetrahydrofuran, dioxane, and diglyme; diethylform Amides such as amide, dimethylacetoamide, N-methyl-2-pyrrolidone and dimethylimidazolidinone; sulfur-based solvents such as dimethyl sulfoxide and sulfolane; alcohols are preferable.

The amount of the dispersion medium in the slurry is an amount such that the solid content concentration of the slurry is usually in the range of 1 to 50% by weight, preferably 5 to 50% by weight, and more preferably 10 to 30% by weight.

(Challenge)

In the slurry composition for electrochemical element electrodes of this invention, you may contain a electrically conductive material. As the conductive material, conductive carbon such as acetylene black, Ketjen black, carbon black, graphite, vapor grown carbon fibers, and carbon nanotubes can be used. By using a electrically conductive material, the electrical contact of electrode active materials can be improved, and when using for a lithium ion secondary battery, a discharge rate characteristic can be improved. The compounding quantity of a electrically conductive material is 0-20 weight part normally with respect to 100 weight part of electrode active materials, Preferably it is 1-10 weight part.

(Thickener)

In the slurry composition for electrochemical element electrodes of this invention, you may contain a thickener further. Examples of the thickener include cellulose-based polymers such as carboxymethyl cellulose, methyl cellulose and hydroxypropyl cellulose and their ammonium salts and alkali metal salts; (modified) poly (meth) acrylic acid and their ammonium salts and alkali metal salts; (modified) polyvinyl alcohol , Polyvinyl alcohols such as copolymers of acrylic acid or acrylate and vinyl alcohol, maleic anhydride or copolymers of maleic acid or fumaric acid and vinyl alcohol; polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, modified polyacrylic acid, oxidation Starch, phosphate starch, casein, various modified starches, and the like. Among them, ammonium salts and alkali metal salts of carboxymethyl cellulose are preferred because they have less air bubbles during aqueous solution adjustment. Moreover, since the low molecular weight surfactant contained in the conventional binder does not exist in the binder of this invention, foamability is low and a smooth electrode can be obtained by combining these.

0.4-1.6 are preferable and, as for the etherification degree of the ammonium salt and alkali metal salt of carboxymethylcellulose, 0.8-1.5 are more preferable. If the degree of etherification is within this range, the solubility of cellulose in water can be ensured. Moreover, since the low molecular weight surfactant contained in the conventional binder does not exist in the binder of this invention, foamability is low and a smooth electrode can be obtained by combining these. Here, etherification degree means substitution degree with respect to the substituent with respect to the carboxymethyl group of hydroxyl groups (three), etc. per anhydroglucose unit in cellulose. Theoretically, it can take values from 0 to 3. As the degree of etherification increases, the proportion of hydroxyl groups in cellulose decreases, and the proportion of substituents increases. As the degree of etherification decreases, the hydroxyl groups in cellulose increase and the substituents decrease. The degree of etherification (substitution degree) is determined by the following method and formula.

First, 0.5-0.7 g of samples are precisely weighed and incinerated in a magnetic crucible. After cooling, the obtained ash is transferred to a 500 ml beaker, about 250 ml of water and 35 ml of N / 10 sulfuric acid are further added, followed by boiling for 30 minutes. This is cooled, a phenolphthalein indicator is added, and the excess acid is reverse titrated with N / 10 potassium hydroxide to calculate the degree of substitution from the following equation.

A = (a × fb × f ¹ ) / sample (g) -alkalinity (or + acidity)

Degree of substitution = M × A / (10000-80A)

A: Amount of N / 10 sulfuric acid consumed by bound alkali metal ions in 1 g of sample (ml)

a ： The amount of N / 10 sulfuric acid used (ml)

f ： Titer of N / 10 sulfuric acid

b: Proper amount of N / 10 potassium hydroxide (ml)

f ¹ : Potency coefficient of N / 10 potassium hydroxide

M: Weight average molecular weight of a sample

The 1 weight% aqueous solution viscosity (henceforth simply "aqueous solution viscosity") of a thickener is based on JISZ 8803: 1991 by a single cylindrical rotational viscometer (25 degreeC, rotation speed = 60 rpm, spindle shape: No.4). The value of 1 minute after start of measurement is said.

1,000 mPa * s or more of aqueous solution viscosity is preferable, and 2,000-15,000 mPa * s is more preferable. When aqueous solution viscosity is this range, an electrode active material is uniformly coat | covered with a thickener, and it can suppress that the polymer of the cell part in the binder particle of this invention adsorb | sucks on the electrode active material surface.

Moreover, if this carboxymethylcellulose aqueous solution only uses what is 2,000-15,000 mPa, you may use combining what is less than 2,000 mPa.

As for the compounding quantity of a thickener, 0.5-2.0 weight part is preferable with respect to 100 weight part of electrode active materials. If the compounding quantity of a thickener is this range, applicability | paintability and adhesiveness with an electrical power collector are favorable. In addition, in the above, "(modified) poly" means "unmodified poly" or "modified poly", and "(meth) acryl" means "acryl" or "methacryl". Moreover, a thickener may be used individually by 1 type, and may use 2 or more types together.

(Other additives)

In addition to the above components, the slurry composition for electrochemical device electrodes of the present invention may further contain other components, such as electrolyte additives having functions such as reinforcing materials, dispersants, and electrolyte solution decomposition suppression, and may be described later. It may be included in. These are not particularly limited as long as they do not affect the battery reaction.

As the reinforcing material, various inorganic and organic spherical, plate-like, rod-like or fibrous fillers can be used. By using the reinforcing material, a strong and flexible electrode can be obtained, and excellent long-term cycle characteristics can be exhibited. The amount of the reinforcing agent used is usually 0.01 to 20 parts by weight, preferably 1 to 10 parts by weight based on 100 parts by weight of the electrode active material. By being included in the above range, high capacity and many load characteristics can be exhibited.

Examples of the dispersant include anionic compounds, cationic compounds, nonionic compounds, and high molecular compounds. The dispersant is selected according to the electrode active material and the conductive material to be used. The content rate of the dispersing agent in the slurry composition for electrochemical element electrodes becomes like this. Preferably it is 0.01-10 weight part with respect to 100 weight part of electrode active materials. When the content rate of a dispersing agent is the said range, the slurry is excellent in stability, a smooth electrode can be obtained, and high battery capacity can be exhibited.

Moreover, you may add various additives to the slurry composition for electrochemical element electrodes. Specifically, nano fine particles, such as fumed silica and fumed alumina, are mentioned. By mixing nanoparticles, the thixotropy of the slurry composition for electrochemical element electrodes can be controlled, and the leveling property of the electrode obtained by it can be improved further. The content rate of the nano fine particles in the slurry composition for electrochemical device electrodes is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the electrode active material. When nanoparticles are in the said range, it is excellent in slurry stability and productivity, and shows high battery characteristics.

(Method for producing slurry composition for electrochemical device electrodes)

The slurry composition for electrochemical element electrodes of this invention is obtained by mixing the said binder particle for electrochemical elements, an electrode active material, a dispersion medium, and the thickener, electrically conductive material, etc. which are used as needed.

Although the mixing method is not specifically limited, For example, the method of using mixing apparatuses, such as stirring, agitation, and rotation, is mentioned. Moreover, the method using the dispersion kneading apparatuses, such as a homogenizer, a ball mill, a sand mill, a roll mill, and a planetary kneader, is mentioned.

The viscosity of the slurry is also different depending on the type of the applicator and the shape of the application line, but is usually 100 to 100,000 mPa · s, preferably 1,000 to 50,000 mPa · s, more preferably 5,000 to 20,000 mPa · s.

(Method for Producing Electrode)

The electrode for electrochemical elements of this invention is obtained by apply | coating and drying said slurry composition for electrochemical element electrodes to an electrical power collector, and forming an electrode active material layer. The current collector is not particularly limited as long as it is a conductive and electrochemically durable material, but from the viewpoint of heat resistance, for example, iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, gold, platinum Metal materials, such as these, are preferable. Especially, aluminum is especially preferable for the positive electrode of a lithium ion secondary battery, and copper is especially preferable for the negative electrode. Although the shape of an electrical power collector is not specifically limited, It is preferable that it is a sheet form with a thickness of about 0.001-0.5 mm. In order that an electrical power collector may raise adhesive strength with an electrode active material layer, it is preferable to use it, roughening previously. Examples of the roughening method include mechanical roughening, electrolytic roughening, and chemical roughening. In the mechanical polishing method, a polishing cloth on which abrasive particles are fixed, a wire brush provided with a grindstone, an emery buff, a steel wire, or the like is used. Moreover, in order to improve the adhesive strength and electroconductivity of an electrode active material layer, you may form an intermediate | middle layer in the electrical power collector surface.

The manufacturing method of an electrode may be a method of binding the electrode active material layer in a layered form on at least one side of the current collector, preferably on both sides. The coating method to the collector of the slurry composition for electrochemical element electrodes is not specifically limited. For example, methods, such as a doctor blade method, a dip method, the reverse roll method, the direct roll method, the gravure method, the extrusion method, the brush coating method, are mentioned.

As a drying method of the apply | coated slurry, the drying method by irradiation with warm air, hot air, low humidity wind, vacuum drying, (far) infrared rays, an electron beam, etc. are mentioned, for example. Among them, a drying method by far-infrared irradiation is preferable.

As for a drying temperature and a drying time, the temperature and time which can remove the solvent in a apply | coated slurry completely are preferable, As a drying temperature, it is 100-300 degreeC, Preferably it is 120-250 degreeC. As drying time, it is 10 minutes-100 hours normally, Preferably it is 20 minutes-20 hours.

After apply | coating and drying the said slurry for electrodes on an electrical power collector, it is preferable to have a process of making the porosity of an electrode active material layer low by pressurization process using a metal mold | die press, a roll press, etc. The range of 50 degreeC-150 degreeC is preferable, and, as for the temperature of a hot press, 80 degreeC-130 degreeC is more preferable. The preferred range of the porosity is 5% to 15%, more preferably 7% to 13%. If the porosity is too high, the charging efficiency and the discharge efficiency deteriorate. If the porosity is too low, a high volume capacity is hardly obtained, or the electrode active material layer is easily peeled off from the current collector, causing a problem of poorly occurring.

The thickness of the electrode active material layer obtained is 5-300 micrometers normally, Preferably it is 30-250 micrometers. By the thickness of an electrode active material layer being in the said range, the flexibility and adhesiveness of an electrode become favorable.

(Electrochemical element)

The electrode of this invention is used especially suitably as an electrode of electrochemical elements, such as a lithium ion secondary battery, an electric double layer capacitor, and a lithium ion capacitor. Although not limited at all as an electrochemical element, the example using the electrode of this invention as an electrode of a lithium ion secondary battery is demonstrated in more detail.

(Lithium ion secondary battery)

The lithium ion secondary battery which is an example of the electrochemical element which concerns on this invention has a positive electrode, a negative electrode, a separator, and electrolyte solution, and at least one of a positive electrode and a negative electrode is an electrode of this invention.

(Electrolytic solution)

Although electrolyte solution is not specifically limited, For example, what melt | dissolved lithium salt as a supporting electrolyte in non-aqueous solvent can be used. Examples of lithium salts include LiPF ₆ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlCl ₄ , LiClO ₄ , CF ₃ SO ₃ Li, C ₄ F ₉ SO ₃ Li, CF ₃ COOLi, (CF ₃ CO) _{2 NLi, (CF 3 SO 2} ) 2 NLi, (C 2 F 5 SO 2) can be cited lithium salts such as NLi. LiPF ₆ , LiClO ₄ , and CF ₃ SO ₃ Li, which are particularly easy to dissolve in a solvent and exhibit a high degree of dissociation, are preferably used. These can be used individually or in mixture of 2 or more types. The amount of the supporting electrolyte is usually 1% by weight or more, preferably 5% by weight or more, and usually 30% by weight or less, preferably 20% by weight or less with respect to the electrolyte solution. Even if the amount of the supporting electrolyte is too small or too large, the ionic conductivity is lowered and the charging and discharging characteristics of the battery are lowered.

The solvent used for the electrolytic solution is not particularly limited as long as it dissolves the supporting electrolyte, but is usually dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), butylene carbonate ( BC) and alkyl carbonates such as methyl ethyl carbonate (MEC); esters such as γ-butyrolactone and methyl formate, ethers such as 1,2-dimethoxyethane and tetrahydrofuran; sulfolane, and Sulfur-containing compounds such as dimethyl sulfoxide; and the like. In particular, dimethyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, and methyl ethyl carbonate are preferable because high ion conductivity is easily obtained and the use temperature range is wide. These can be used individually or in mixture of 2 or more types.

In other than the electrolytic solution, there may be mentioned an inorganic solid electrolyte of polyethylene oxide, a gel polymer electrolyte or by impregnating an electrolytic solution in the polymer electrolyte, such as polyacrylonitrile, lithium sulfide, such as LiI, Li ₃ N.

Moreover, you may use it, containing an additive in the said electrolyte solution. As electrolyte solution additive, carbonate type compounds, such as vinylene carbonate (VC), are preferable.

(Separator)

The separator is a porous substrate having pores. Examples of the separator that can be used include (a) a porous separator having pores, (b) a porous separator having a polymer coat layer formed on one or both surfaces thereof, or (c) an inorganic ceramic powder. Porous separators having a porous resin coat layer are included, and non-limiting examples thereof include polypropylene-based, polyethylene-based, polyolefin-based, or aramid-based porous separators, polyvinylidene fluoride, polyethylene oxide, and polyacrylonitrile. A porous film layer comprising a polymer film for a solid polymer electrolyte or a gel polymer electrolyte such as a nitrile or polyvinylidene fluoride hexafluoropropylene copolymer, a separator coated with a gelled polymer coat layer, or a dispersant for an inorganic filler or an inorganic filler. This coated separator etc. are mentioned.

(Method of manufacturing battery)

The manufacturing method of a lithium ion secondary battery is not specifically limited. For example, the negative electrode and the positive electrode are overlapped with each other via a separator, wound or bent along the shape of the battery, placed in a battery container, and the electrolyte is injected into the battery container to be sealed. In addition, an over-current protection element such as an expanded metal, a fuse, a PTC element, a lead plate, or the like may be placed, if necessary, to prevent pressure rise inside the battery and overcharge / discharge. The shape of the battery may be any of a laminated cell type, a coin type, a button type, a sheet type, a cylindrical shape, a square type, a flat type, and the like.

(Example)

Although an Example is given to the following and this invention is demonstrated, this invention is not limited to this. In addition, the part and% in a present Example are a basis of weight unless there is particular notice.

In Examples and Comparative Examples, various physical properties were evaluated as follows.

(Weight average molecular weight of quaternized polymer (II))

The weight average molecular weight of the quaternized polymer (II) was measured by gel permeation chromatography using water as a developing solvent and calculated in terms of standard polyoxyethylene.

(Electrochemical properties)

(1) Cyclic Voltametry (CV) Measurement

The quaternized polymer (II) is cast to a glass carbon electrode having a diameter of 3 mm phi, to obtain an electrode to which the polymer (II) is cast at 60 ° C for 5 hours. 1 mol / liter of LiPF ₆ was added to a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 25 by using a cast electrode obtained, using lithium metal as the counter electrode and the reference electrode at a volume ratio of 25 ° C. Each electrode was immersed in the electrolyte solution dissolved to a concentration, and cyclic voltammetry (hereinafter abbreviated as CV) was measured, and the host speed was set to 1 mV / sec, and was performed in the range of 0 to 3 V. do. The same measurement is performed also by the glass carbon electrode in which the polymer (II) is not cast. And the current value in 0.01V in the CV measurement performed using the electrode cast the polymer (II), and 0.01 in the CV measurement using the glazed carbon electrode in which the polymer (II) was not cast. The determination was made based on the following criteria, with the ratio of the current value at V (the following formula) as an index of the ease of decomposition. The smaller the following ratio, the better the decomposition resistance.

[Equation 1]

SA ： less than 80%

A: 80% or more-less than 101%

B: 101% or more but less than 200%

C: 200% or more but less than 300%

D: 300% or more but less than 400%

(Charge and discharge characteristics)

(1) Initial charge and discharge characteristics

Using the laminated cell-type batteries obtained in the examples and the comparative examples, in a manner of constant current constant voltage charging method of 0.1 C at 25 ° C., respectively, charging at constant current until 4.2 V, then charging at constant voltage, and then at 0.1 C A charge and discharge cycle of discharging up to 3.0 V with a constant current was performed. The ratio of the discharge capacity to the charge capacity was expressed as a percentage to set initial charge and discharge efficiency, and the result was determined based on the following criteria. The larger this value is, the less battery the initial capacity deteriorates.

SA ： 98% or more

A: 96% or more and less than 98%

B: 92% or more and less than 96%

C: 88% or more and less than 92%

D ： less than 88%

(2) charge and discharge cycle characteristics

Using the laminated cell batteries obtained in the examples and the comparative examples, in a manner of constant current constant voltage charging method of 0.1 C at 25 ° C., respectively, charging at constant current until 4.2 V, then charging at constant voltage, and then at 0.1 C A charge and discharge cycle of discharging up to 3.0 V at a constant current of was performed. The charge / discharge cycle was carried out up to 50 cycles, and the ratio of the discharge capacity at the 100th cycle to the initial discharge capacity was determined based on the following criteria. The larger this value, the smaller the decrease in capacity due to repeated charging and discharging.

SA ： 85% or more

A: 80% or more and less than 85%

B: 75% or more and less than 80%

C: 70% or more but less than 75%

D: 65% or more but less than 70%

E: 60% or more but less than 65%

F ： less than 60%

(3) charge and discharge rate characteristics (load characteristics)

Except having changed the measurement conditions into the constant current amount 2.0C, it carried out similarly to the measurement of the charge / discharge cycle characteristic, and measured the discharge capacity in each constant current amount. The ratio of the discharge capacity in these conditions with respect to said battery capacity was computed as a percentage, it was set as the charge / discharge rate characteristic, and it determined by the following reference | standard. The larger this value, the smaller the internal resistance, indicating that high-speed charging and discharging is possible.

SA ： 80% or more

A: 70% or more but less than 80%

B: 60% or more and less than 70%

C: 50% or more but less than 60%

D: 40% or more but less than 50%

E ： less than 40%

(Pinhole number on electrode surface)

A 10 cm × 10 cm electrode plate was produced, and the number of spots (number of pinholes) on the surface of the electrode active material layer was evaluated based on the following criteria. The smaller the number of spots (the number of pinholes), the less corrosion of the current collector, and the more uniform the electrode surface.

A ： No pinhole

B ： 1 to 5 pinholes

C ： 6-10 pinholes

D ： 10-30 pinholes

E ： 31 or more pinholes

(Example 1)

40 parts of ethyl methyl ketone was injected into the reactor, and the temperature was raised to 120 ° C. under a nitrogen atmosphere, and 3.0 parts of azobisisobutyronitrile, 60 parts of dimethylaminoethyl methacrylate, 70 parts of butyl acrylate, and 20 parts of methyl methacrylate were mixed. It was dripped at constant speed for 3 hours, and also reacted for 3 hours, and manufactured polymer (I-1). The prepared polymer (I-1) was further cooled to 60 ° C., 145 parts of nitrotrismethylenephosphonic acid as quaternization agent (molar number for nitrogen atom in dimethylaminoethyl methacrylate was 1 mol) and ion exchanged water 500 Part was added to prepare quaternized polymer (II-1). The weight average molecular weight of the quaternized polymer (II-1) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-1) was 40% with respect to the whole structural unit of a polymer.

To the obtained quaternized polymer (II-1), 1 part of iron sulfate and 1 part of ascorbic acid were added, the temperature was raised to 80 ° C, a mixture of 80 parts of butyl acrylate, 40 parts of methyl methacrylate, and 30 parts of acrylonitrile, and hydrogen peroxide 1 part of water and 50 parts of ion-exchanged water were simultaneously dripped at the same speed for 3 hours, and it was made to react for further 5 hours, and the quaternized polymer (II-1) was used as a cell part, and butylacrylate / methylmethacrylate / acryl The dispersion of the binder particle of the core-cell structure which used the nitrile copolymer (elastic polymer) as a core part was obtained. The obtained dispersion was concentrated to obtain an emulsion of binder particles having a solid content concentration of 40%. In addition, the ratio of the structural unit derived from acrylonitrile in a core part was 20%.

(Manufacture of negative electrode)

The 1% aqueous solution was adjusted using the carboxymethylcellulose (Daicel Chemical Industry Co., Ltd. "Daicel2200") whose 1-% aqueous solution viscosity is 2,000 mPa * s.

100 parts of artificial graphite were put into the planetary mixer with a disper, 100 parts of said aqueous solutions were added to this, and it adjusted to solid content concentration 53.5% with ion-exchange water, and mixed at 25 degreeC for 60 minutes. Next, after adjusting to 44% of solid content concentration by ion-exchange water, it mixed at 25 degreeC for 15 minutes.

Next, 2 parts of the emulsion of the binder particle obtained above were put in conversion of solid content, and it mixed for 10 more minutes. This was defoamed under reduced pressure to obtain a slurry for electrodes having good fluidity.

The electrode slurry composition was coated on a copper foil having a thickness of 20 μm with a comma coater so that the film thickness after drying was about 200 μm, and dried at 60 ° C. for 2 minutes at a speed of 0.5 m / min, and 2 minutes at 120 ° C. Heat treatment was performed to obtain an electrode disk. This electrode original disk was rolled by roll press, and the electrode for negative electrodes whose thickness of an electrode active material layer is 80 micrometers was obtained.

(Production of positive electrode)

100 parts of LiNiO ₂ as a positive electrode active material, 2.5 parts of an aqueous dispersion of an emulsion of the binder particles as a binder (solid content concentration of 40%), 40 parts of an aqueous solution of carboxymethylcellulose having an etherification degree of 0.8 as a thickener (solid content concentration of 2%), and an appropriate amount Of water was mixed with a planetary mixer to obtain a slurry for the positive electrode. The slurry for the positive electrode was applied to an aluminum foil having a thickness of 18 μm, dried at 50 ° C. for 20 minutes, then heated at 150 ° C. for 2 hours, and then roll-pressed to obtain a positive electrode having a thickness of 100 μm from the electrode active material layer. Got it.

The battery container was manufactured using the laminated | multilayer film which the both sides of the aluminum sheet coat | covered with resin which consists of polypropylene. Subsequently, the electrode active material layer was removed from the edge part using the said positive electrode and the negative electrode, respectively, and the positive electrode welded Ni tab and the negative electrode welded Cu tab at the removed point. The obtained positive electrode and the negative electrode were wound and placed in the battery container with a separator made of a microporous membrane made of polyethylene with the electrode active material layer surfaces of the positive electrode facing each other. Then here, the ethylene carbonate and diethyl carbonate in a volume ratio in the 25 ℃ 1: in a mixed solvent of 2, was injected into the electrolyte dissolved therein to a concentration of 1 mol / liter of LiPF _6. Subsequently, the laminate film was sealed to prepare a laminate cell type lithium ion secondary battery. Table 2 shows the evaluation results of this battery performance.

(Example 2)

Except for using lithium titanate (Li ₄ Ti ₅ O ₁₂ ) instead of artificial graphite as the negative electrode active material, the same operations as in Example 1 were carried out, and the emulsion of the binder particles having a core-cell structure, the slurry for the electrode, the electrode and A coin-type lithium ion secondary battery was produced and evaluated. The results are shown in Table 1 and Table 2.

(Example 3)

The quaternized polymer (II-1) obtained in Example 1 was heated to 50 ° C, and a mixture of 80 parts of butadiene, 40 parts of styrene and 30 parts of acrylonitrile, 0.3 parts of potassium persulfate and 50 parts of ion-exchanged water were simultaneously 4 The core-cell structure was added dropwise at a constant velocity over time, and further reacted for 6 hours, wherein the quaternized polymer (II-1) was used as the cell portion, and the styrene / butadiene / acrylonitrile copolymer (elastic polymer) was used as the core portion. A dispersion of binder particles was obtained. The obtained dispersion was concentrated to obtain an emulsion of binder particles having a solid content concentration of 40%. Except having used this as an emulsion of binder particle | grains, operation similar to Example 1 was performed, the slurry for electrodes, the electrode, and the coin-type lithium ion secondary battery were manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 4)

To the obtained quaternized polymer (II-1), instead of a mixture of 80 parts of butyl acrylate, 40 parts of methyl methacrylate and 30 parts of acrylonitrile, 98 parts of butyl acrylate, 40 parts of methyl methacrylate, acrylonitrile 12 Except having added the negative mixture, the same operation as in Example 1 was carried out to prepare an emulsion of a binder particle having a core and cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery, and evaluated. . The results are shown in Table 1 and Table 2. In addition, the ratio of the structural unit derived from acrylonitrile in a core part was 8%.

(Example 5)

To the obtained quaternized polymer (II-1), instead of a mixture of 80 parts of butyl acrylate, 40 parts of methyl methacrylate, and 30 parts of acrylonitrile, 80 parts of butyl acrylate, 28 parts of methyl methacrylate, and acrylonitrile 42 Except having added the negative mixture, the same operation as in Example 1 was carried out to prepare an emulsion of a binder particle having a core and cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery, and evaluated. . The results are shown in Table 1 and Table 2. In addition, the ratio of the structural unit derived from acrylonitrile in the core part was 28%.

(Example 6)

40 parts of ethyl methyl ketone was introduced into a reactor, and the temperature was raised to 120 ° C. under a nitrogen atmosphere, and 3.0 parts of azobisisobutyronitrile, 27 parts of dimethylaminoethyl methacrylate, 96 parts of butyl acrylate, and 27 parts of methyl methacrylate were mixed. It was dripped at constant speed for 3 hours, and also it reacted for 3 hours, and manufactured polymer (I-2). The prepared polymer (I-2) was further cooled to 60 ° C., 70 parts of nitrotrismethylenephosphonic acid as quaternization agent (molar number of nitrogen atoms in dimethylaminoethyl methacrylate is 1 mol) and ion exchanged water 500 Part was added to prepare quaternized polymer (II-2). The weight average molecular weight of the quaternized polymer (II-2) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-2) was 18% with respect to the whole structural unit of a polymer.

Except for using the quaternized polymer (II-2) instead of the quaternized polymer (II-1) as the quaternized polymer, the same operation as in Example 1 was carried out, and the quaternized polymer (II-2) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 7)

40 parts of ethyl methyl ketone was introduced into the reactor, and the temperature was raised to 120 ° C. under a nitrogen atmosphere, 3.0 parts of azobisisobutyronitrile, 48 parts of dimethylaminoethyl methacrylate, 85 parts of butyl acrylate, and 20 parts of methyl methacrylate were mixed. It was dripped at constant speed for 3 hours, and also reacted for 3 hours, and polymer (I-3) was manufactured. The prepared polymer (I-3) was further cooled to 60 ° C, 70 parts of nitrotrismethylenephosphonic acid as quaternization agent (molar number of nitrogen atoms in dimethylaminoethyl methacrylate is 1 mol) and ion exchanged water 500 Part was added to prepare quaternized polymer (II-3). The weight average molecular weight of the quaternized polymer (II-3) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-3) was 32% with respect to all the structural units of a polymer.

Except for using the quaternized polymer (II-3) instead of the quaternized polymer (II-1) as the quaternized polymer, the same operation as in Example 1 was carried out, and the quaternized polymer (II-3) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 8)

40 parts of ethyl methyl ketone were injected into the reactor, and the temperature was raised to 120 ° C. under a nitrogen atmosphere, and 3.0 parts of azobisisobutyronitrile, 72 parts of dimethylaminoethyl methacrylate, 60 parts of butyl acrylate, and 15 parts of methyl methacrylate were mixed. It was dripped at constant speed for 3 hours, and also it reacted for 3 hours, and manufactured polymer (I-4). The prepared polymer (I-4) was further cooled to 60 ° C., 174 parts of nitrotrismethylenephosphonic acid as quaternization agent (molar number for nitrogen atom in dimethylaminoethyl methacrylate was 1 mol) and ion exchanged water 500 Parts were added to form a quaternized polymer (II-4). The weight average molecular weight of the quaternized polymer (II-4) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-4) was 48% with respect to all the structural units of a polymer.

Except for using the quaternized polymer (II-4) instead of the quaternized polymer (II-1) as the quaternized polymer, the same operation as in Example 1 was carried out, and the quaternized polymer (II-4) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 9)

40 parts of ethyl methyl ketone were introduced into the reactor, and the temperature was raised to 120 ° C. under a nitrogen atmosphere, 3.0 parts of azobisisobutyronitrile, 96 parts of dimethylaminoethyl methacrylate, and 54 parts of butyl acrylate were mixed and added dropwise at 3 hours, The mixture was further reacted for 3 hours to prepare polymer (I-5). The prepared polymer (I-5) was further cooled to 60 ° C., 232 parts of nitrotrismethylenephosphonic acid as quaternization agent (the number of moles of nitrogen atoms in dimethylaminoethyl methacrylate was 1 mol) and ion exchanged water 500 Parts were added to form a quaternized polymer (II-5). The weight average molecular weight of the quaternized polymer (II-5) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-5) was 64% with respect to all the structural units of a polymer.

As the quaternization polymer, the same operation as in Example 1 was carried out except that the quaternization polymer (II-5) was used instead of the quaternization polymer (II-1), and the quaternization polymer (II-5) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 10)

As the quaternizing agent of the polymer (I-1), except for using 25 parts of acetic acid (the number of moles of nitrogen atoms in dimethylaminoethyl methacrylate is 1 mol) instead of 145 parts of nitrotrismethylenephosphonic acid, Example 1 and The same operation was performed and the quaternization polymer (II-6) was manufactured. The weight average molecular weight of the quaternized polymer (II-6) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-6) was 40% with respect to all the structural units of a polymer.

As the quaternized polymer, the same operation as in Example 1 was carried out except that the quaternized polymer (II-6) was used instead of the quaternized polymer (II-1), and the quaternized polymer (II-6) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 11)

As the quaternizing agent of the polymer (I-1), except that 72 parts of p-toluenesulfonic acid (the number of moles of nitrogen atoms in dimethylaminoethyl methacrylate is about 1 mole) instead of 145 parts of nitrotrismethylenephosphonic acid, The same operation as in Example 1 was carried out to produce a quaternized polymer (II-7). The weight average molecular weight of the quaternized polymer (II-7) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-7) was 40% with respect to the whole structural unit of a polymer.

As the quaternized polymer, the same operation as in Example 1 was carried out except that the quaternized polymer (II-7) was used instead of the quaternized polymer (II-1), and the quaternized polymer (II-7) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 12)

In the preparation of the polymer (I-1), 40 parts of ethyl methyl ketone is charged into a reactor, and heated to 120 ° C. under a nitrogen atmosphere, 0.8 parts of azobisisobutyronitrile, 60 parts of dimethylaminoethyl methacrylate, and butyl acryl. 70 parts of rate and 20 parts of methyl methacrylate were mixed, this was dripped at constant speed for 3 hours, and it was made to react for further 5 hours to produce polymer (I-8), and it was nitro as a quaternizing agent of polymer (I-8). The quaternization polymer (II-8) was carried out in the same manner as in Example 1, except that 25 parts of acetic acid (the number of moles of the nitrogen atom in dimethylaminoethyl methacrylate was 1 mole) instead of 145 parts of trismethylenephosphonic acid. And binder particles having a core-cell structure, wherein the quaternized polymer (II-8) is used as the cell portion, and the butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) is used as the core portion. To prepare the emulsion, the lithium ion secondary battery of the slurry, electrodes and coin-shaped electrode, were evaluated. In addition, the weight average molecular weight of the quaternization polymer (II-8) was 6,000. The results are shown in Table 1 and Table 2.

In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-8) was 40% with respect to all the structural units of a polymer.

(Example 13)

In the preparation of the polymer (I-1), 40 parts of ethyl methyl ketone are charged into a reactor, and heated to 120 ° C. under a nitrogen atmosphere, 5 parts of azobisisobutyronitrile, 60 parts of dimethylaminoethyl methacrylate, and butyl acryl. 70 parts of rate and 20 parts of methyl methacrylates were mixed, and this was dripped at constant speed for 3 hours, polymer (I-9) was produced, and 145 parts of nitrotrismethylene phosphonic acid as a quaternizing agent of polymer (I-9) A quaternization polymer (II-9) was prepared by the same operation as in Example 1, except that 25 parts of acetic acid (the number of moles of the nitrogen atom in dimethylaminoethyl methacrylate was 1 mole) was used instead. Emulsion of the binder particle of the core-cell structure, slurry for electrodes, which uses a polymer (II-9) as a cell part, and uses a butylacrylate / methylmethacrylate / acrylonitrile copolymer (elastic polymer) as a core part, To prepare the electrode and a lithium ion secondary battery of the coin-type, it was evaluated. The results are shown in Table 1 and Table 2.

In addition, the weight average molecular weight of the quaternization polymer (II-9) was 80,000. Content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has a lone electron pair in quaternization polymer (II-9) was 40% with respect to all the structural units of a polymer.

(Example 14)

A quaternization polymer (II-10) was carried out in the same manner as in Example 1, except that the amount of nitrotrismethylenephosphonic acid was 43.5 parts (the number of moles of the nitrogen atom in dimethylaminoethyl methacrylate was 0.3 mol). Was prepared. The weight average molecular weight of the quaternized polymer (II-10) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-10) was 40% with respect to the whole structural unit of a polymer.

As the quaternized polymer, the same operation as in Example 1 was carried out except that the quaternized polymer (II-10) was used instead of the quaternized polymer (II-1), and the quaternized polymer (II-10) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 15)

The quaternization polymer (II-11) was carried out in the same manner as in Example 1, except that the amount of nitrotrismethylenephosphonic acid was set to 116 parts (the number of moles of the nitrogen atom in dimethylaminoethyl methacrylate was 0.8 mole). Was prepared. The weight average molecular weight of the quaternized polymer (II-11) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-11) was 40% with respect to the whole structural unit of a polymer.

As the quaternized polymer, the same operation as in Example 1 was carried out except that the quaternized polymer (II-11) was used instead of the quaternized polymer (II-1), and the quaternized polymer (II-11) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 16)

A quaternization polymer (II-12) was carried out in the same manner as in Example 1, except that the amount of nitrotrismethylenephosphonic acid was set to 260 parts (the number of moles of the nitrogen atom in dimethylaminoethyl methacrylate was 1.8 mol). Was prepared. The weight average molecular weight of the quaternized polymer (II-12) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-12) was 40% with respect to the whole structural unit of a polymer.

Except for using the quaternized polymer (II-12) instead of the quaternized polymer (II-1) as the quaternized polymer, the same operation as in Example 1 was carried out, and the quaternized polymer (II-12) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Example 17)

The quaternization polymer (II-13) was performed in the same manner as in Example 1 except that the amount of nitrotrisethylene phosphonic acid was set to 435 parts (the number of moles of the nitrogen atom in dimethylaminoethyl methacrylate was 3 mol). Was prepared. The weight average molecular weight of the quaternized polymer (II-13) was 25,000. In addition, content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has the lone electron pair in quaternization polymer (II-13) was 40% with respect to the whole structural unit of a polymer.

Except for using the quaternized polymer (II-13) instead of the quaternized polymer (II-1) as the quaternized polymer, the same operation as in Example 1 was carried out, and the quaternized polymer (II-13) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Comparative Example 1)

In an autoclave equipped with a stirrer, 200 parts of water, 0.5 parts of sodium lauryl sulfate, 1.0 parts of potassium persulfate, 0.5 parts of sodium bisulfite and 30 parts of styrene, 39 parts of butadiene, 30 parts of methyl methacrylate, ita 1 part of cholic acid and 0.1 part of (alpha)-styrene dimers were respectively injected, and it was made to react at 45 degreeC for 6 hours. Thereafter, a mixture of 45 parts of styrene, 25 parts of butadiene, 20 parts of methyl methacrylate, 1 part of itaconic acid and 0.2 parts of α-styrene dimer was continuously added at 60 ° C. over 7 hours to continue the polymerization, and further After the completion of the continuous addition, the product was reacted at 70 ° C. over 6 hours to obtain a product. The obtained product was deodorized and concentrated, and the solid content concentration was adjusted to 40% to obtain an emulsion of binder particles. The same procedure as in Example 1 was carried out except that the emulsion of the binder particles was used as an emulsion of the binder particles to prepare an emulsion of the binder particles, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery, and evaluated. It was. The electrochemical stability of sodium dodecylbenzenesulfonate is not cast using an electrolyte solution obtained by dissolving sodium dodecylbenzenesulfonate at a concentration of 0.1% by weight in an electrolyte solution without using a cast electrode in CV measurement. The measurement was carried out with a non-glazed carbon electrode. Other measurement conditions were carried out in the same manner as in Example 1. The results are shown in Table 1 and Table 2.

(Comparative Example 2)

As the quaternizing agent of the polymer (I-1), except for using 40 parts of phosphoric acid (the number of moles of nitrogen atoms in dimethylaminoethyl methacrylate is 1 mole) instead of 145 parts of nitrotrismethylenephosphonic acid, Example 1 and The same operation was performed and the quaternization polymer (II-14) was manufactured. Content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has a 25,000 and lone electron pair as the weight average molecular weight of a quaternization polymer (II-14) was 40% with respect to all the structural units of a polymer.

As the quaternized polymer, the same operation as in Example 1 was carried out except that the quaternized polymer (II-14) was used instead of the quaternized polymer (II-1), and the quaternized polymer (II-14) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Comparative Example 3)

Example 1, except that 60 parts of methyl iodide (the number of moles to the nitrogen atom in dimethylaminoethyl methacrylate is 1 mole) was used instead of 145 parts of nitrotrismethylenephosphonic acid as the quaternizing agent of the polymer (I-1). The same operation as described above was carried out to produce quaternized polymer (II-15). Content of the monomer (dimethylaminoethyl methacrylate) unit containing the atom which has 25,000 and lone electron pairs as the weight average molecular weight of a quaternization polymer (II-15) was 40% with respect to all the structural units of a polymer.

Except for using the quaternized polymer (II-15) instead of the quaternized polymer (II-1) as the quaternized polymer, the same operation as in Example 1 was carried out, and the quaternized polymer (II-15) was used as the cell portion. Emulsion of a core-cell structure, an electrode slurry, an electrode, and a coin-type lithium ion secondary battery having a butyl acrylate / methyl methacrylate / acrylonitrile copolymer (elastic polymer) as a core part. It manufactured and evaluated. The results are shown in Table 1 and Table 2.

(Comparative Example 4)

Except for using lithium titanate (Li ₄ Ti ₅ O ₁₂ ) instead of artificial graphite as the negative electrode active material, the same operation as in Comparative Example 2 was carried out to produce an emulsion of a binder particle having a core-cell structure, an electrode slurry, an electrode, and A coin-type lithium ion secondary battery was produced and evaluated. The results are shown in Table 1 and Table 2.

(Comparative Example 5)

Except for using lithium titanate (Li ₄ Ti ₅ O ₁₂ ) instead of artificial graphite as the negative electrode active material, the same operation as in Comparative Example 3 was carried out to produce an emulsion of a binder particle having a core-cell structure, an electrode slurry, an electrode, and A coin-type lithium ion secondary battery was produced and evaluated. The results are shown in Table 1 and Table 2.

The following results can be seen from the results in Table 2. According to the present invention, as shown in the examples, lithium is obtained by using binder particles made of a polymer containing a monomer unit in which the cell portion contains an atom having an isolated electron pair, and wherein the atom is quaternized with an organic acid. Since it does not contain the component which decomposes in the electric potential inserted into a negative electrode, it is excellent in electrochemical characteristics and excellent charge / discharge characteristic. Moreover, since an organic acid is used, an electrical power collector does not corrode and an electrode surface is uniform.

On the other hand, when the polymerization is carried out using a surfactant, the cell unit contains a monomer unit containing an atom having an lone pair of electrons, and a non-polymeric polymer in which the atom is quaternized cationic (Comparative Example 1) In the case of using a polymer formed by quaternary cationization (Comparative Examples 2 to 5), the electrochemical characteristics and charge / discharge characteristics are inferior, or the current collector is highly corroded, resulting in uneven electrodes.

Claims (10)

It consists of a core part and a cell part,
Binder particle | grains for electrochemical elements which consist of a polymer in which a cell part contains the atom unit containing the atom which has an lone electron pair, and the said atom is quaternized with the organic acid. The method of claim 1,
The binder particle | grains for electrochemical elements whose weight average molecular weights of the said polymer are 5,000-100,000. The method according to claim 1 or 2,
The polymer constituting the cell portion is quaternized with an organic acid of an atom having the isolated electron pair of the polymer containing an atom having the isolated electron pair,
The binder particle | grains for electrochemical elements whose usage-amount of the organic acid used for the said quaternization cationization is 0.5-2.0 mol with respect to 1 mol of atoms which have the said isolated electron pair. The method according to any one of claims 1 to 3,
The polymer which forms a core part is an elastomer, and the said elastomer is any of a fluoropolymer, a diene polymer, and an acrylate polymer, The binder particle | grains for electrochemical elements. The binder composition for electrochemical elements in which the binder particle for electrochemical elements in any one of Claims 1-4 is disperse | distributed to a dispersion medium. The method of claim 5, wherein
The binder composition for an electrochemical device, wherein the dispersion medium is water. The binder particle for electrochemical elements as described in any one of Claims 1-4,
Slurry composition for electrochemical element electrodes containing an electrode active material and a dispersion medium. The electrochemical element electrode manufactured by apply | coating and drying the slurry composition for electrochemical element electrodes of Claim 7 to an electrical power collector. An electrochemical device having the electrode of claim 8. Polymerizing a polymerizable composition containing a monomer containing an atom having an isolated electron pair, and obtaining a polymer (I) containing an atom having an isolated electron pair,
A step of quaternizing an atom having an isolated electron pair contained in the polymer (I) with an organic acid to obtain a polymer (II), and
The manufacturing method of the binder particle for electrochemical elements of Claim 1 containing the process of manufacturing an elastic polymer in presence of a polymer (II).