WO2019203333A1 - Solid electrolyte composition, sheet for all-solid secondary battery, all-solid secondary battery, and method of manufacturing sheet for all-solid secondary battery or all-solid secondary battery - Google Patents

Abstract

Provided are: a solid electrolyte composition comprising a specific additive, a salt of a metal of Group I or Group II of the periodic table, an inorganic solid electrolyte conductive to ions of a metal of Group I or Group II of the periodic table, binder particles including a polymer having a specific partial structure, and a disperse medium; a sheet for an all-solid secondary battery and an all-solid secondary battery using the composition; and a method of manufacturing each of the sheet for an all-solid secondary battery and an all-solid secondary battery.

Description

Solid electrolyte composition, sheet for all-solid secondary battery and all-solid-state secondary battery, and method for producing sheet for all-solid-state secondary battery or all-solid-state secondary battery

The present invention relates to a solid electrolyte composition, an all-solid secondary battery sheet and an all-solid secondary battery, and a method for producing an all-solid secondary battery sheet or an all-solid secondary battery.

A lithium ion secondary battery is a storage battery that has a negative electrode, a positive electrode, and an electrolyte sandwiched between the negative electrode and the positive electrode, and can be charged and discharged by reciprocating lithium ions between the two electrodes. Conventionally, an organic electrolytic solution has been used as an electrolyte in a lithium ion secondary battery. However, the organic electrolyte is liable to leak, and there is a possibility that a short circuit occurs inside the battery due to overcharge and overdischarge, resulting in ignition, and further improvement in reliability and safety is required.
Under such circumstances, an all-solid secondary battery using an inorganic solid electrolyte instead of an organic electrolyte has been attracting attention. The all-solid-state secondary battery is composed of a solid negative electrode, electrolyte, and positive electrode, which can greatly improve safety and reliability, which are the problems of batteries using organic electrolytes, and can also extend the service life. It will be. Furthermore, the all-solid-state secondary battery can have a structure in which an electrode and an electrolyte are directly arranged in series. Therefore, it is possible to increase the energy density as compared with a secondary battery using an organic electrolyte, and application to an electric vehicle or a large storage battery is expected.

In such all-solid secondary batteries, the binding between solid particles such as inorganic solid electrolytes, the binding between the layers constituting the battery, and / or the binding between the active material layer and the current collector ( Hereinafter, it is also described as “binding property between solid particles”, etc.) to improve battery performance. In order to enhance the binding property between solid particles and the like, the battery constituent layer of the negative electrode active material layer, the solid electrolyte layer, and the positive electrode active material layer contains an inorganic solid electrolyte and a binder (binder). It has been proposed to form with materials. As such a material, for example, Patent Document 1 includes a specific inorganic solid electrolyte, a binder particle having an average particle diameter of 10 nm or more and 50,000 nm or less and containing an ion conductive substance, and a dispersion medium. A solid electrolyte composition is described. By using this solid electrolyte composition as a material constituting the constituent layer, in the obtained all-solid-state secondary battery, the binding property between solid particles is increased, the resistance is reduced, and the discharge capacity retention rate is improved. It is said that you can. Patent Document 2 describes an all-solid-state secondary battery slurry containing an inorganic solid electrolyte, an ion conductive polymer, an alkali metal salt, and an ether or / and ketone solvent having a boiling point of 100 to 250 ° C. Has been. By using this solid electrolyte composition as a material constituting the constituent layer, the obtained all-solid-state secondary battery has a uniform constituent layer and can extend the life of the battery.

International Publication No. 2017/99248 International Publication No. 2014/51032

In preparation for practical application of all-solid-state secondary batteries, studies are underway to mass-produce all-solid-state secondary batteries as well as reducing battery resistance and improving battery performance such as discharge capacity. In order to improve the battery performance as compared with the all-solid secondary battery described in each of the above patent documents, it is required to further improve the binding property between the solid particles. Moreover, the sheet | seat for all-solid-state secondary batteries which has a solid electrolyte layer and / or an electrode active material layer is distribute | circulated in the state wound up with the roll, This roll is unwound and an all-solid-state secondary battery is manufactured (mass production). Form is expected to be desirable. In order to increase the sheet area to be transported at once, even if the sheet for an all-solid-state secondary battery is bent with a smaller bending radius than the conventional sheet (even when wound in a roll shape), the solid electrolyte layer and / or the electrode active material layer is cracked. It is required to impart properties that are difficult to cause damage such as cracks. Therefore, it is necessary to improve the binding property between solid particles and the like as compared with the prior art.

The present invention uses an all-solid-state secondary battery sheet as a material constituting the constituent layer of the all-solid-state secondary battery sheet, so that the obtained all-solid-state secondary battery sheet is bent at a small bending radius and wound into a roll. Even if it solves, it makes it a subject to provide the solid electrolyte composition which can make a solid electrolyte layer and / or an electrode active material layer hard to produce a damage. In addition, the present invention provides a solid electrolyte composition capable of realizing a reduction in resistance and an excellent discharge capacity in the obtained all-solid-state secondary battery by using it as a material constituting the constituent layer of the all-solid-state secondary battery. This is the issue. Furthermore, the present invention provides an all-solid-state secondary battery sheet and an all-solid-state secondary battery, and an all-solid-state secondary battery sheet and an all-solid-state secondary battery manufacturing method using this solid electrolyte composition. The task is to do.

As a result of various studies, the inventors have dispersed an additive having a specific structure, a specific metal salt, a specific inorganic solid electrolyte, and a binder particle having a specific cross-linked structure in a dispersion medium. The above-mentioned damage can be made difficult to occur by forming a sheet for an all-solid secondary battery or a layer (constituting layer) constituting the all-solid-state secondary battery using the solid electrolyte composition. It has been found that even if it is in a state of being contained in the constituent layer without removing the additive, it is possible to impart excellent battery performance to the all-solid secondary battery. The present invention has been further studied based on these findings and has been completed.

　式（１）中、Ｒ^１及びＲ^２は、水素原子、アルキル基、アリール基又はアシル基を示す。ｎは１以上の整数を示す。Ｘは、アルキレン基、アリーレン基、－Ｏ－、－Ｓ－又は単結合を示す。Ｒ^１とＲ^２は互いに結合して環を形成してもよい。
　Ｌ^１はアルキレン基又はアリーレン基を示す。Ｙは、アルキレン基、アリーレン基、－Ｏ－、－Ｓ－、－Ｎ（Ｒｓ）－、－Ｐ（＝Ｏ）（ＯＲｔ）－、－Ｃ（＝Ｏ）－、－Ｃ（＝Ｓ）－、又は、－Ｏ－、－Ｓ－、－Ｎ（Ｒｓ）－、－Ｐ（＝Ｏ）（ＯＲｔ）－及びＣ（＝Ｏ）－から選択される基の少なくとも２つが組み合わされた２価の連結基を示す。ここで、Ｒｓ及びＲｔは、水素原子、アルキル基又はアリール基である。ｎが２以上の整数のとき、－Ｌ^１－Ｙ－の繰り返し部分は互いに同一であっても異なっていてもよい。

　式（２）中、ｓは２～２０の整数を示す。Ｒ^３は水素原子又はアルキル基を示す。Ｌ^２は－（ＣＨ_２）_ｔ－又は－Ｃ（＝Ｏ）－を示し、ｔは０～１０の整数を示す。Ｌ^３は、酸素原子及び窒素原子の少なくとも１種を含むｓ価の連結基を示す。ここで、Ｌ^２を構成する炭素原子が、Ｌ^３を構成する酸素原子又は窒素原子と結合する。 That is, the above problem has been solved by the following means.
<1>
Conductivity of an additive represented by the following formula (1), a salt of a metal belonging to Group 1 or 2 of the periodic table, and an ion of a metal belonging to Group 1 or 2 of the periodic table A solid electrolyte composition comprising an inorganic solid electrolyte, binder particles containing a polymer having a partial structure represented by the following formula (2), and a dispersion medium.

In formula (1), R ¹ and R ² represent a hydrogen atom, an alkyl group, an aryl group, or an acyl group. n represents an integer of 1 or more. X represents an alkylene group, an arylene group, —O—, —S— or a single bond. R ¹ and R ² may combine with each other to form a ring.
L ¹ represents an alkylene group or an arylene group. Y represents an alkylene group, an arylene group, —O—, —S—, —N (Rs) —, —P (═O) (ORt) —, —C (═O) —, —C (═S) —. Or a divalent combination of at least two groups selected from —O—, —S—, —N (Rs) —, —P (═O) (ORt) —, and C (═O) —. A linking group is shown. Here, Rs and Rt are a hydrogen atom, an alkyl group, or an aryl group. When n is an integer of 2 or more, the repeating parts of -L ¹ -Y- may be the same as or different from each other.

In the formula (2), s represents an integer of 2 to 20. R ³ represents a hydrogen atom or an alkyl group. L ² represents — (CH ₂ ) _t — or —C (═O) —, and t represents an integer of 0 to 10. L ³ represents an s-valent linking group containing at least one of an oxygen atom and a nitrogen atom. Wherein the carbon atoms constituting L ² binds to the oxygen atom or nitrogen atom constituting L ^3.

<2>
The solid electrolyte composition according to <1>, wherein the additive has a molecular weight of less than 10,000.
<3>
The solid electrolyte according to <1> or <2>, wherein the ratio of the additive to the metal salt is, by mass ratio, additive: metal salt = 1: 0.1 to 0.1: 1 Composition.

　式（３）中、Ｒ^５は水素原子、ハロゲン原子、アルキル基又はアリール基を示し、＊は結合部を示す。 <4>
The solid electrolyte composition according to any one of <1> to <3>, wherein the polymer has at least one structure represented by the following formula (3).

In formula (3), R ⁵ represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and * represents a bonding part.

　式（４）中、Ｌ^４は単結合又は２価の連結基を示し、Ｒ^６は水素原子、ハロゲン原子、アルキル基又はアリール基を示す。＊は結合部を示す。 <5>
The solid electrolyte composition according to any one of <1> to <4>, wherein the polymer has at least one structure represented by the following formula (4).

In formula (4), L ⁴ represents a single bond or a divalent linking group, and R ⁶ represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group. * Indicates a connecting part.

<6>
The solid electrolyte composition according to any one of <1> to <5>, wherein the polymer has a glass transition temperature of −100 to 80 ° C.
<7>
<1> to <6>, wherein the glass transition temperature of the mixture comprising the additive, the binder particles, and the metal salt contained in the solid electrolyte composition is −120 to 40 ° C. The solid electrolyte composition described.
<8>
The solid electrolyte composition according to any one of <1> to <7>, wherein the polymer has at least one functional group selected from the following functional group group.
[Functional group group]
An acidic functional group, a basic functional group, a hydroxy group, a cyano group, an alkoxysilyl group, an aryl group, a heteroaryl group, a hydrocarbon ring group in which three or more rings are condensed.
<9>
The solid electrolyte composition according to any one of <1> to <8>, wherein the metal salt is contained inside the polymer.
<10>
The solid electrolyte composition according to any one of <1> to <9>, wherein the inorganic solid electrolyte is a sulfide-based inorganic solid electrolyte.
<11>
The solid electrolyte composition according to any one of <1> to <10>, comprising an active material.

<12>
<1>-<11> A sheet for an all-solid-state secondary battery having a layer composed of the solid electrolyte composition according to any one of <11>.
<13>
The sheet for an all-solid-state secondary battery according to <12>, wherein the layer contains the above additive in an amount of 100 ppm or more on a mass basis when heated at 200 ° C. for 6 hours at 1 atm.
<14>
An all solid state secondary battery comprising a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order,
All solids in which at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is a layer composed of the solid electrolyte composition according to any one of <1> to <11> Secondary battery.
<15>
<1>-<11> The manufacturing method of the sheet | seat for all-solid-state secondary batteries which forms the solid electrolyte composition as described in any one of <11>.
<16>
The manufacturing method of an all-solid-state secondary battery which manufactures an all-solid-state secondary battery via the manufacturing method as described in <15>.

By using the solid electrolyte composition of the present invention as a material constituting the constituent layer of the all-solid-state secondary battery sheet, the obtained all-solid-state secondary battery sheet is bent at a small bending radius and wound into a roll. Even if the roll state is released, the solid electrolyte layer and / or the electrode active material layer can be hardly damaged. In addition, by using the solid electrolyte composition of the present invention as a material constituting the constituent layer of the all-solid secondary battery, it is possible to realize a reduction in resistance and an excellent discharge capacity in the obtained all-solid secondary battery. Even if the sheet for an all-solid-state secondary battery of the present invention is bent with a small bending radius and wound into a roll shape and the roll state is released, the solid electrolyte layer and / or the electrode active material layer is hardly damaged. The all solid state secondary battery of the present invention has a low resistance and an excellent discharge capacity. Moreover, the manufacturing method of the all-solid-state secondary battery sheet | seat and all-solid-state secondary battery of this invention manufactures the all-solid-state secondary battery sheet | seat and all-solid-state secondary battery of this invention which show the said outstanding characteristic, respectively. Can do.

It is a longitudinal cross-sectional view which shows typically the all-solid-state secondary battery which concerns on preferable embodiment of this invention. It is a longitudinal cross-sectional view which shows typically the all-solid-state secondary battery (coin battery) produced in the Example.

In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the present specification, when “acryl” or “(meth) acryl” is simply described, it means acrylic and / or methacrylic.
In the present specification, the indication of a compound (for example, when referring to a compound with a suffix) is used to mean that the compound itself, its salt, and its ion are included. In addition, it is meant to include derivatives in which a part thereof is changed, such as introduction of a substituent, within a range where a desired effect is exhibited.
In the present specification, a substituent that does not specify substitution or non-substitution (the same applies to a linking group) means that the group may have an appropriate substituent. This is also synonymous for compounds that do not specify substitution or non-substitution. Examples of such a substituent include the substituent T described later.
In this specification, when it is simply described as a YYY group, the YYY group may further have a substituent.
In the present specification, when there are a plurality of substituents, linking groups, etc. (hereinafter referred to as substituents, etc.) indicated by specific symbols, or when a plurality of substituents etc. are specified simultaneously or alternatively, It means that a substituent etc. may mutually be same or different. In addition, even when not specifically stated, when a plurality of substituents and the like are adjacent to each other, they may be connected to each other or condensed to form a ring.

[Solid electrolyte composition]
The solid electrolyte composition of the present invention includes an additive represented by the following formula (1), a salt of a metal belonging to Group 1 or 2 of the periodic table, and Group 1 or 2 of the periodic table. An inorganic solid electrolyte having conductivity of metal ions belonging to the above, binder particles having a partial structure represented by the following formula (2), and a dispersion medium.
The solid electrolyte composition of the present invention can be preferably used as a molding material for an all-solid secondary battery sheet or a solid electrolyte layer or an active material layer of an all-solid secondary battery.

In the solid electrolyte composition of the present invention, the mode (mixing mode) containing the additive, the metal salt, the inorganic solid electrolyte, the binder particles, and the dispersion medium is not particularly limited. The components may be dispersed and may be present as a mixture in which some or all of the additives, metal salts, and binder particles are aggregated. This mixture may be a composite. Examples of the composite include an embodiment having a metal salt inside the polymer, which will be described later. The metal salt may be dissociated.

The reason why the solid electrolyte composition of the present invention exhibits the above-mentioned effects is not yet clear, but is estimated as follows.
The solid electrolyte composition of the present invention contains an additive, a metal salt, and binder particles in a dispersion medium in combination, thereby forming a sheet for an all-solid secondary battery or a constituent layer of an all-solid secondary battery. When used as a material, the additive is retained in the constituent layer without being removed by volatilization or evaporation. Due to the presence of the additive in the constituent layer, the polymer constituting the binder particles having a specific structure (a structure composed of an s-valent linking group containing at least one kind of oxygen atom and nitrogen atom) has an appropriate flexibility. It is considered that the ionic conductivity and the electronic conductivity in the above-mentioned constituent layer can be improved by making the properties of the polymer constituting the binder particles compatible with the wettability with respect to the solid component. Combined with these actions, when the solid electrolyte composition of the present invention is used to form the all-solid secondary battery sheet or the constituent layer of the all-solid secondary battery, the solid particles are firmly bound to each other. In addition, it is considered that the reduction in resistance due to good contact between the solid particles can be exhibited in a balanced manner, and the discharge capacity of the all-solid secondary battery can be improved.

The solid electrolyte composition of the present invention is not particularly limited, but the moisture content (also referred to as water content) is preferably 500 ppm or less, more preferably 200 ppm or less, and further preferably 100 ppm or less. It is preferably 50 ppm or less. When the water content of the solid electrolyte composition is small, deterioration of the inorganic solid electrolyte can be suppressed. The water content indicates the amount of water contained in the solid electrolyte composition (mass ratio with respect to the solid electrolyte composition). Specifically, the water content is filtered through a 0.02 μm membrane filter, and Karl Fischer titration is used. The measured value.

Hereinafter, components contained in the solid electrolyte composition of the present invention and components that can be contained will be described.

<Additives>
An additive consists of a compound represented by following formula (1).

In formula (1), R ¹ and R ² represent a hydrogen atom, an alkyl group, an aryl group, or an acyl group. n represents an integer of 1 or more. X represents an alkylene group, an arylene group, —O—, —S— or a single bond. R ¹ and R ² may combine with each other to form a ring.
L ¹ represents an alkylene group or an arylene group. Y represents an alkylene group, an arylene group, —O—, —S—, —N (Rs) —, —P (═O) (ORt) —, —C (═O) —, —C (═S) —. Or a divalent combination of at least two groups selected from —O—, —S—, —N (Rs) —, —P (═O) (ORt) —, and C (═O) —. A linking group is shown. L ¹ and Y are not both alkylene groups. Y represents —O—, —S—, —N (Rs) —, —P (═O) (ORt) —, —C (═O) —, —C (═S) —, or —O—. , —S—, —N (Rs) —, —P (═O) (ORt) — and C (═O) — represent a divalent linking group in which at least two groups selected from the group are combined. preferable. Here, Rs and Rt are each independently a hydrogen atom, an alkyl group, or an aryl group.
When n is an integer of 2 or more, the repeating parts of -L ¹ -Y- may be the same or different.

X and Y are preferably the following combinations.
X is —O—, Y is —O—, X is —S—, Y is —S—, X is alkylene, Y is —C (═O) —O—, X is a single bond , Y is a combination of —O—C (═O) —O—, X is an alkylene, and Y is a combination of —O—C (═O) —O—.

The alkyl group represented by R ¹ and R ² may be linear, branched or cyclic, and preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1. Specific examples of the alkyl group include methyl, ethyl, i-propyl, t-butyl, pentyl and cyclohexyl, and methyl is preferred.

The aryl group represented by R ¹ and R ² is preferably an aryl group having 6 to 16 carbon atoms, more preferably an aryl group having 6 to 14 carbon atoms, still more preferably an aryl group having 6 to 10 carbon atoms, such as phenyl And naphthyl, and phenyl is preferred.

The acyl group represented by R ¹ and R ² is preferably an alkylcarbonyl group or an arylcarbonyl group. The alkyl group of the alkylcarbonyl group is synonymous with the above alkyl group, and the preferred range is also the same. The aryl group of the arylcarbonyl group is synonymous with the above aryl group, and the preferred range is also the same.

N is preferably an integer of 1 to 50, more preferably an integer of 1 to 20, and still more preferably 1 to 10.

The alkylene group represented by X may be linear, branched or cyclic, and preferably has 1 to 10 carbon atoms, more preferably 1 to 5 and even more preferably 1 to 3. Specific examples of the alkylene group include methylene, ethylene, trimethylene, 2-methyltrimethylene and cyclohexylene.

The arylene group represented by X is preferably an arylene group having 6 to 16 carbon atoms, more preferably an arylene group having 6 to 14 carbon atoms, still more preferably an arylene group having 6 to 10 carbon atoms, such as phenylene and naphthylene. And phenylene is preferred.

The alkylene group and arylene group represented by L ¹ are synonymous with the alkylene group and arylene group represented by X, and the preferred range is also the same.

The alkylene group and arylene group represented by Y are synonymous with the alkylene group and arylene group represented by X, and the preferred range is also the same.

The alkyl group and aryl group represented by Rs and Rt are synonymous with the alkyl group and aryl group represented by R ¹ and R ² , and the preferred range is also the same.

A divalent linking group in which at least two groups selected from —O—, —S—, —N (Rs) —, —P (═O) (ORt) — and —C (═O) — are combined. For example, —C (═O) —O—, —O—C (═O) —, —O—C (═O) —O—, —C (═O) —S—, —S— C (= O)-, -C (= S) -S-, -SC (= S)-, -SC (= O) -O-, -SC (= O) -S- , -SC (= S) -S-, -C (= O) -N (Rs)-, -N (Rs) -C (= O)-, -N (Rs) -C (= O) —N (Rs) —, —O—C (═O) —N (Rs) —, —N (Rs) —C (═O) —O—, —C (═S) —N (Rs) —, -N (Rs) -C (= S)-, -N (Rs) -C (= S) -N (Rs)-, -O-C (= S) -N (Rs)-, -N ( s) -C (= S) -O -, - P (= O) (ORt) -O -, - O-P (= O) (ORt) -, and the like.

The molecular weight of the additive is preferably less than 10,000, more preferably 5,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less. The lower limit is preferably 50 or more, more preferably 100 or more, and still more preferably 150 or more.
When the additive has a molecular weight distribution, “molecular weight of the additive” means a mass average molecular weight. Further, the mass average molecular weight / number average molecular weight (polydispersity index Mw / Mn) is preferably 10 or less, more preferably 5 or less, and even more preferably less than 3. The lower limit is preferably 1 or more.
When the molecular weight or Mw / Mn is in the above range, the film strength of the all-solid-state secondary battery sheet can be further improved.
The mass average molecular weight and number average molecular weight of the additive can be measured in the same manner as in the method for measuring the molecular weight of the polymer and macromonomer described later.

Hereinafter, although the specific example of an additive is described, this invention is not limited to these. In the exemplified compounds, n1 represents an integer from 5 to the upper limit of n, and n2 has the same meaning as n.

An additive may be used individually by 1 type and may be used in combination of 2 or more type. In the total content of the additive and the solid content contained in the solid electrolyte composition of the present invention, it is preferable to contain 0.05 to 20% by mass of the additive, the metal salt, and the binder particles in total. 0.1 to 15% by mass is more preferable, and 0.1 to 10% by mass is more preferable.
In this specification, solid content (solid component) means the component which does not lose | disappear by volatilizing or evaporating, when a solid electrolyte composition is dried at 170 degreeC under a nitrogen atmosphere at 170 degreeC for 1 hour. In addition, even if it is a component which does not burn out on the said conditions which do not lose | disappear, an additive shall not be included in the said solid content.
Further, in the mixture composed of the additive, the metal salt and the binder particles, the content of the binder particles is preferably 30 to 99% by mass, more preferably 40 to 90% by mass, and further 55 to 85% by mass. preferable.

In the solid electrolyte composition of the present invention, the content ratio of the additive to the metal salt (additive: metal salt) is preferably 1: 0.1 to 0.1: 1 by mass ratio, preferably 1: 0. More preferred is 3 to 0.3: 1, and further more preferred is 1: 0.5 to 0.5: 1. When the content ratio is in the above range, the film strength can be further improved.

<Metal salt>
The metal salt used in the present invention is preferably a metal salt usually used in this type of product, and more preferably a lithium salt. Specific examples of metal salts are described below.

(L-1) Inorganic lithium salts: inorganic fluoride salts such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiN (FSO ₂ ) ₂ ; perhalogenates such as LiClO ₄ , LiBrO ₄ , LiIO ₄ ; LiAlCl inorganic chloride salts such as _4.

(L-2) Fluorine-containing organic lithium salt: perfluoroalkane carboxylate such as LiCF ₃ CO ₂ , perfluoroalkane sulfonate such as LiCF ₃ SO ₃ ; LiN (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ Perfluoroalkanesulfonylimide salts such as SO ₂ ) (FSO ₂ ), LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ); LiC (CF ₃ SO ₂ ) Perfluoroalkanesulfonylmethide salts such as ₃ ; Li [PF ₅ (CF ₂ CF ₂ CF ₃ )], Li [PF ₄ (CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF _{3) 3], Li [PF} 5 (CF 2 CF 2 CF 2 CF 3)], Li [PF 4 (CF 2 CF 2 CF 2 CF 3) 2], Li [PF ₃ (CF ₂ CF ₂ CF ₂ CF ₃ ) ₃ ] and the like.

(L-3) Oxalatoborate salt: lithium bis (oxalato) borate, lithium difluorooxalatoborate and the like.

(L-4) Inorganic sodium salts: inorganic fluoride salts such as NaPF ₆ , NaBF ₄ , NaAsF ₆ , NaSbF ₆ , NaN (FSO ₂ ) ₂ ; perhalogenates such as NaClO ₄ , NaBrO ₄ , NaIO ₄ ; NaAlCl inorganic chloride salts such as _4.

Of these, the following metal salts are preferred.

Metal salts may be used alone or in combination of two or more.

<Inorganic solid electrolyte>
The solid electrolyte composition of the present invention contains an inorganic solid electrolyte.
In the present invention, the inorganic solid electrolyte is an inorganic solid electrolyte, and the solid electrolyte is a solid electrolyte capable of moving ions inside. Since it does not contain organic substances as the main ion conductive material, organic solid electrolytes (polymer electrolytes typified by polyethylene oxide (PEO), etc., organics typified by lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), etc. It is clearly distinguished from the electrolyte salt). In addition, since the inorganic solid electrolyte is solid in a steady state, it is not usually dissociated or released into cations and anions. In this respect, it is also clearly distinguished from an electrolyte or an inorganic electrolyte salt (such as LiPF ₆ , LiBF ₄ , lithium bis (fluorosulfonyl) imide (LiFSI), LiCl, etc.) in which cations and anions are dissociated or liberated in the polymer. Is done. The inorganic solid electrolyte is not particularly limited as long as it has conductivity of ions of metals belonging to Group 1 or Group 2 of the periodic table, and generally does not have electron conductivity. When the all solid state secondary battery of the present invention is a lithium ion battery, the inorganic solid electrolyte preferably has lithium ion ionic conductivity.
As the inorganic solid electrolyte, a solid electrolyte material usually used for an all-solid secondary battery can be appropriately selected and used. Typical examples of inorganic solid electrolytes include (i) sulfide-based inorganic solid electrolytes and (ii) oxide-based inorganic solid electrolytes. In the present invention, a sulfide-based inorganic solid electrolyte is preferably used from the viewpoint that a better interface can be formed between the active material and the inorganic solid electrolyte.

(I) Sulfide-based inorganic solid electrolyte The sulfide-based inorganic solid electrolyte contains a sulfur atom (S) and has ion conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and Those having electronic insulating properties are preferred. The sulfide-based inorganic solid electrolyte preferably contains at least Li, S and P as elements and has lithium ion conductivity. However, depending on the purpose or the case, other than Li, S and P may be used. An element may be included.

Examples of the sulfide-based inorganic solid electrolyte include a lithium ion conductive inorganic solid electrolyte that satisfies the composition represented by the following formula (1).

L _a1 M _b1 P _c1 S _d1 A _e1 (1)

In the formula, L represents an element selected from Li, Na and K, and Li is preferred. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al, and Ge. A represents an element selected from I, Br, Cl and F. a1 to e1 indicate the composition ratio of each element, and a1: b1: c1: d1: e1 satisfies 1 to 12: 0 to 5: 1: 2 to 12: 0 to 10. a1 is preferably 1 to 9, and more preferably 1.5 to 7.5. b1 is preferably 0 to 3, and more preferably 0 to 1. d1 is preferably 2.5 to 10, and more preferably 3.0 to 8.5. e1 is preferably from 0 to 5, and more preferably from 0 to 3.

The composition ratio of each element can be controlled by adjusting the blending amount of the raw material compound when producing the sulfide-based inorganic solid electrolyte as described below.

The sulfide-based inorganic solid electrolyte may be amorphous (glass) or crystallized (glass ceramic), or only a part may be crystallized. For example, Li—PS system glass containing Li, P, and S, or Li—PS system glass ceramics containing Li, P, and S can be used.
The sulfide-based inorganic solid electrolyte includes, for example, lithium sulfide (Li ₂ S), phosphorus sulfide (for example, diphosphorus pentasulfide (P ₂ S ₅ )), simple phosphorus, simple sulfur, sodium sulfide, hydrogen sulfide, lithium halide (for example, LiI, LiBr, LiCl) and a sulfide of the element represented by M (for example, SiS ₂ , SnS, GeS ₂ ) can be produced by reaction of at least two raw materials.

The ratio of Li ₂ S to P ₂ S ₅ in the Li—PS system glass and Li—PS system glass ceramics is a molar ratio of Li ₂ S: P ₂ S ₅ , preferably 60:40 to 90:10, more preferably 68:32 to 78:22. By setting the ratio of Li ₂ S to P ₂ S ₅ within this range, the lithium ion conductivity can be increased. Specifically, the lithium ion conductivity can be preferably 1 × 10 ⁻⁴ S / cm or more, more preferably 1 × 10 ⁻³ S / cm or more. Although there is no particular upper limit, it is practical that it is 1 × 10 ⁻¹ S / cm or less.

Examples of combinations of raw materials are shown below as specific examples of sulfide-based inorganic solid electrolytes. For example, Li ₂ S—P ₂ S ₅ , Li ₂ S—P ₂ S ₅ —LiCl, Li ₂ S—P ₂ S ₅ —H ₂ S, Li ₂ S—P ₂ S ₅ —H ₂ S—LiCl, Li ₂ S—LiI—P ₂ S ₅ , Li ₂ S—LiI—Li ₂ O—P ₂ S ₅ , Li ₂ S—LiBr—P ₂ S ₅ , Li ₂ S—Li ₂ O—P ₂ S ₅ , Li ₂ S—Li ₃ PO ₄ —P ₂ S ₅ , Li ₂ S—P ₂ S ₅ —P ₂ O ₅ , Li ₂ S—P ₂ S ₅ —SiS ₂ , Li ₂ S—P ₂ S ₅ —SiS _2- LiCl, Li ₂ S—P ₂ S ₅ —SnS, Li ₂ S—P ₂ S ₅ —Al ₂ S ₃ , Li ₂ S—GeS ₂ , Li ₂ S—GeS ₂ —ZnS, Li ₂ S—Ga _{2 S 3, Li 2 S-} GeS 2 -Ga 2 S 3, Li 2 S-GeS 2 -P 2 S 5 _{Li 2 S-GeS 2 -Sb 2} S 5, Li 2 S-GeS 2 -Al 2 S 3, Li 2 S-SiS 2, Li 2 S-Al 2 S 3, Li 2 S-SiS 2 -Al 2 S ₃ , Li ₂ S—SiS ₂ —P ₂ S ₅ , Li ₂ S—SiS ₂ —P ₂ S ₅ —LiI, Li ₂ S—SiS ₂ —LiI, Li ₂ S—SiS ₂ —Li ₄ SiO ₄ , Li ₂ S—SiS ₂ —Li ₃ PO ₄ , Li ₁₀ GeP ₂ S _{12 and the} like. However, the mixing ratio of each raw material does not matter. Examples of a method for synthesizing a sulfide-based inorganic solid electrolyte material using such a raw material composition include an amorphization method. Examples of the amorphization method include a mechanical milling method, a solution method, and a melt quench method. This is because processing at room temperature is possible, and the manufacturing process can be simplified.

(Ii) Oxide-based inorganic solid electrolyte The oxide-based inorganic solid electrolyte contains an oxygen atom (O) and has ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and Those having electronic insulating properties are preferred.
The oxide-based inorganic solid electrolyte preferably has an ionic conductivity of 1 × 10 ⁻⁶ S / cm or more, more preferably 5 × 10 ⁻⁶ S / cm or more, and 1 × 10 ⁻⁵ S. / Cm or more is particularly preferable. The upper limit is not particularly limited, but is practically 1 × 10 ⁻¹ S / cm or less.

As a specific compound example, for example, Li _xa La _ya TiO ₃ [xa satisfies 0.3 ≦ xa ≦ 0.7, and ya satisfies 0.3 ≦ ya ≦ 0.7. (LLT); Li _xb La _yb Zr _zb M ^bb _{mb Onb} (M ^bb is one or more elements selected from Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In and Sn) Xb satisfies 5 ≦ xb ≦ 10, yb satisfies 1 ≦ yb ≦ 4, zb satisfies 1 ≦ zb ≦ 4, mb satisfies 0 ≦ mb ≦ 2, nb satisfies 5 ≦ nb ≦ 20 Li _xc B _yc M ^cc _{zc Onc} (M ^cc is one or more elements selected from C, S, Al, Si, Ga, Ge, In and Sn. Xc is 0 ≦ xc ≦ 5 Yc satisfies 0 ≦ yc ≦ 1, zc satisfies 0 ≦ zc ≦ 1, and nc satisfies 0 ≦ nc ≦ 6); Li _xd (Al, Ga) _yd (Ti, Ge) _zd Si _ad P _{md Ond} (xd satisfies 1 ≦ xd ≦ 3, yd Satisfies 0 ≦ yd ≦ 1, zd satisfies 0 ≦ zd ≦ 2, ad satisfies 0 ≦ ad ≦ 1, md satisfies 1 ≦ md ≦ 7, and nd satisfies 3 ≦ nd ≦ 13.) Li _(3-2xe) M ^ee _xe D ^ee O (xe represents a number of 0 to 0.1, M ^ee represents a divalent metal atom, D ^ee represents a halogen atom or two or more types of halogen atoms; represent a combination _{of);. Li xf Si yf O} zf (xf satisfies 1 ≦ xf ≦ 5, yf satisfies 0 <yf ≦ 3, zf satisfies _{1 ≦ zf ≦ 10);.} Li xg S yg O _zg (xg satisfies 1 ≦ xg ≦ 3, yg satisfies 0 <yg ≦ 2, and zg satisfies 1 ≦ zg ≦ 10); Li ₃ BO ₃ ; Li ₃ BO ₃ —Li ₂ SO ₄ ; _{Li 2 O-B 2 O 3} -P 2 O 5; Li 2 O-SiO 2 _{Li 6 BaLa 2 Ta 2 O 12} ; Li 3 PO (4-3 / 2w) N w (w is _{w <1); LISICON Li 3.5} Zn 0.25 GeO with (Lithium super ionic conductor) type crystal structure ₄ ; La _0.55 Li _0.35 TiO ₃ having a perovskite-type crystal structure; LiTi ₂ P ₃ O ₁₂ having a NASICON (Natrium super ionic conductor) type crystal structure; Li _{1 + xh + yh} (Al, Ge) _xh (Ti, Ge) _2-xh Si _yh P _3-yh O ₁₂ (xh satisfies 0 ≦ xh ≦ 1 and yh satisfies 0 ≦ yh ≦ 1) And Li ₇ La ₃ Zr ₂ O ₁₂ (LLZ) having a garnet-type crystal structure.
Phosphorus compounds containing Li, P and O are also desirable. For example, lithium phosphate (Li ₃ PO ₄ ); LiPON obtained by substituting a part of oxygen of lithium phosphate with nitrogen; LiPOD ¹ (D ¹ is preferably Ti, V, Cr, Mn, Fe, Co, Ni, And at least one element selected from Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, and Au.
Furthermore, LiA ¹ ON (A ¹ is one or more elements selected from Si, B, Ge, Al, C, and Ga) can be preferably used.

The inorganic solid electrolyte is preferably a particle. In this case, the volume average particle diameter of the inorganic solid electrolyte is not particularly limited, but is preferably 0.01 μm or more, and more preferably 0.1 μm or more. As an upper limit, it is preferable that it is 100 micrometers or less, and it is more preferable that it is 50 micrometers or less. The volume average particle size of the inorganic solid electrolyte is measured by the following procedure. The inorganic solid electrolyte particles are prepared by diluting a 1% by weight dispersion in water (heptane in the case of a substance unstable to water) in a 20 mL sample bottle. The diluted dispersion sample is irradiated with 1 kHz ultrasonic waves for 10 minutes and used immediately after that. Using this dispersion liquid sample, using a laser diffraction / scattering particle size distribution measuring apparatus LA-920 (trade name, manufactured by HORIBA), data acquisition was performed 50 times using a measurement quartz cell at a temperature of 25 ° C. Obtain the volume average particle size. For other detailed conditions, refer to the description of JIS Z 8828: 2013 “Particle Size Analysis—Dynamic Light Scattering Method” as necessary. Five samples are prepared for each level, and the average value is adopted.

An inorganic solid electrolyte may be used individually by 1 type, or may be used in combination of 2 or more type.
When forming a solid electrolyte layer, the mass (mg) (weight per unit area) of the inorganic solid electrolyte per unit area (cm ² ) of the solid electrolyte layer is not particularly limited. It can be determined as appropriate according to the designed battery capacity, for example, 1 to 100 mg / cm ² .
However, when the solid electrolyte composition contains an active material to be described later, the weight of the inorganic solid electrolyte is preferably the total amount of the active material and the inorganic solid electrolyte in the above range.

The content of the inorganic solid electrolyte in the solid electrolyte composition is 5% by mass or more in terms of dispersion stability, reduction in interfacial resistance, and binding properties, with a total of 100% by mass of the additive and the total solid content. Preferably, it is 70% by mass or more, and particularly preferably 90% by mass or more. As an upper limit, it is preferable that it is 99.9 mass% or less from the same viewpoint, It is more preferable that it is 99.5 mass% or less, It is especially preferable that it is 99 mass% or less.
However, when the solid electrolyte composition contains an active material to be described later, the total content of the active material and the inorganic solid electrolyte is preferably in the above range as the content of the inorganic solid electrolyte in the solid electrolyte composition.

<Binder particles>
The polymer constituting the binder particles has a partial structure represented by the following formula (2). The polymer which comprises binder particle | grains may be used individually by 1 type, and may be used in combination of 2 or more type.

In the formula (2), s represents an integer of 2 to 20. R ³ represents a hydrogen atom or an alkyl group. L ² represents — (CH ₂ ) _t — or —C (═O) —, and t represents an integer of 0 to 10. L ³ represents an s-valent linking group containing at least one of an oxygen atom and a nitrogen atom. Here, when t is 0, L ² is a single bond, and when t is an integer of 1 to 10 or when L ² represents —C (═O) —, the carbon atom constituting L ² Is bonded to an oxygen atom or a nitrogen atom constituting L ³ .

S is preferably an integer of 2 to 10.

The alkyl group represented by R ³ is synonymous with the alkyl group represented by R ¹ , and the preferred range is also the same.

T is preferably an integer of 1 to 10, more preferably 1 or 2.

The linking group represented by L ³ is an s-valent linking group containing at least one of an oxygen atom and a nitrogen atom, and includes an oxygen atom, a nitrogen atom, a carbonyl group, —N (R ⁴ ) —, an alkylene group, and an alkenylene group. , An s-valent linking group formed by combining at least two of an arenetriyl group, an alkanetriyl group, and an alkanetetrayl group. Here, R ⁴ represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group.
The linking group may be any of chain, branched and cyclic, and the chain and cyclic linking groups may be bonded to a carbon atom constituting L ² with an oxygen atom or a nitrogen atom at the end of the molecular chain. preferable.

The alkylene group may be linear, branched or cyclic, and the carbon number is preferably 1-20, more preferably 1-10, and even more preferably 2-12. Specific examples of the alkylene group include methylene, ethylene, trimethylene, 2-methyltrimethylene, hexamethylene, cyclohexylene and dodecamethylene.

The alkenylene group may be linear, branched or cyclic, and the carbon number is preferably 2 to 20, more preferably 2 to 12, and further preferably 2 to 4. Specific examples of the alkenylene group include vinylene, propenylene, butenylene, 2-methylbutenylene and cyclohexylene.

The arenetriyl group is preferably an arylene triyl group having 6 to 16 carbon atoms, more preferably an arenetriyl group having 6 to 14 carbon atoms, still more preferably an arenetriyl group having 6 to 10 carbon atoms, for example, benzene Triyl and naphthalene triyl are mentioned.

The alkanetriyl group may be a chain, a ring, or a combination of a chain and a ring. The carbon number of the alkanetriyl group is preferably 1 to 16, more preferably 1 to 12, and particularly preferably 1 to 8. Examples include methanetriyl, ethanetriyl, propanetriyl, butanetriyl, t-butanetriyl, hexanetriyl and cyclohexanetriyl. The “alkanetriyl group in a combination of a chain type and a cyclic group” means, for example, an alkanetriyl group containing a saturated alicyclic ring such as an alkanetriyl group in which a methanetriyl group and three cyclohexylene groups are combined. Means group.

The alkanetetrayl group may be a chain, a ring, or a combination of a chain and a ring. The carbon number of the alkanetetrayl group is preferably 1 to 16, more preferably 1 to 12, and particularly preferably 1 to 8. Examples include methanetetrayl, ethanetetrayl, propanetetrayl, t-butanetetrayl and cyclohexanetetrayl. The term “alkanetetrayl group in combination of chain and cyclic” means, for example, an alkane containing a saturated alicyclic ring such as an alkanetetrayl group in which a methanetetrayl group and four cyclohexylene groups are combined. A tetrayl group is meant.

R ⁴ preferably represents a hydrogen atom, and the halogen atom, alkyl group or aryl group has the same meaning as the halogen atom, alkyl group or aryl group represented by R ¹ , and the preferred range is also the same.

Examples of the divalent linking group represented by L ³ include a linking group in which an oxygen atom and an alkylene group are combined, a linking group in which an imino group, an alkylene group, and an oxygen atom are combined, an oxygen atom, an alkylene group, and an alkenylene group. And a linking group in which an oxygen atom, a carbonyl group, an imino group, and an alkylene group are combined. Specific examples of the divalent linking group represented by L ³ are shown below. In the following linking groups, “*” represents a bonding part. The same applies to the description of the trivalent to decavalent linking groups described later. Moreover, the structure shown in parentheses may be repeated.

Examples of the trivalent linking group represented by L ³ include a linking group in which an alkanetriyl group and an oxygen atom are combined, a linking group in which an imino group, an alkylene group, and a nitrogen atom are combined, an isocyanurate group, and an oxygen atom. And a linking group combining an alkylene group and an isocyanurate group, and a linking group combining an arenetriyl group and an alkylene group. Specific examples of the trivalent linking group represented by L ³ are shown below.

The tetravalent linking group represented by L ³ includes, for example, a linking group combining an alkanetetrayl group and an oxygen atom, a linking group combining an imino group, an alkanetetrayl group, an oxygen atom and an alkylene group, and imino. And a linking group in which a group, an alkylene group, and a nitrogen atom are combined. Specific examples of the tetravalent linking group represented by L ³ are shown below.

Examples of the pentavalent linking group represented by L ³ include a linking group in which two alkanetetrayl groups and an oxygen atom are combined. Specific examples of the pentavalent linking group represented by L ³ are shown below.

The hexavalent linking group represented by L ³ includes, for example, a linking group in which two of the above trivalent linking groups and an oxygen atom are combined, and two of the above trivalent linking group and one of the above divalent linking groups. And a linking group in combination. Specific examples of the hexavalent linking group represented by L ³ are shown below.

Examples of the 10-valent linking group represented by L ³ include a linking group obtained by combining two pentavalent linking groups and one divalent linking group. Specific examples of the decavalent linking group represented by L ³ are shown below.

In order to further improve the film strength in the present invention, the polymer constituting the binder particles preferably has at least one structure represented by the following formula (3), and at least the structure represented by the following formula (4). It is more preferable to have one. The structure represented by the following formula (3) or (4) may be contained as a repeating unit in the polymer constituting the binder particles.

In formula (3), R ⁵ represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and * represents a bonding part. R ⁵ preferably represents a hydrogen atom, and the halogen atom, alkyl group or aryl group has the same meaning as the halogen atom, alkyl group or aryl group represented by R ¹ , and the preferred range is also the same.

In formula (4), L ⁴ represents a single bond or a divalent linking group, and R ⁶ represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group. * Indicates a connecting part.
R ⁶ preferably represents a hydrogen atom, and the halogen atom, alkyl group or aryl group has the same meaning as the halogen atom, alkyl group or aryl group represented by R ¹ , and the preferred range is also the same.
L ⁴ preferably represents a divalent linking group. Examples of the divalent linking group include the divalent linking group represented by L ³ described above. Further, the divalent linking group represented by L ⁴ is preferably an alkylene group, a combination of an alkylene group and an oxygen atom, or a combination of an alkylene group and —N (R ⁴ ) —. As the alkylene group and —N (R ⁴ ) —, those described for L ³ can be used. Further, the molecular weight of L ³ is preferably 14 to 1000, more preferably 14 to 700, and still more preferably 14 to 500.

The polymer constituting the binder particles preferably has at least one functional group selected from the following functional group group.
[Functional group group]
Acid functional group, basic functional group, hydroxy group, cyano group, alkoxysilyl group, aryl group, heteroaryl group, and hydrocarbon ring group in which three or more rings are condensed

The acidic functional group is not particularly limited, and examples thereof include a carboxylic acid group (—COOH), a sulfonic acid group (sulfo group: —SO ₃ H), a phosphoric acid group (phospho group: —OPO (OH) ₂ ), phosphone. An acid group and a phosphinic acid group are mentioned.
The basic functional group is not particularly limited, and examples thereof include an amino group, a pyridyl group, an imino group, and an amidine.
The alkoxysilyl group is not particularly limited, and is preferably an alkoxysilyl group having 1 to 6 carbon atoms, and examples thereof include methoxysilyl, ethoxysilyl, t-butoxysilyl, and cyclohexylsilyl.
The aryl group is not particularly limited and is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include phenyl and naphthyl. The ring of the aryl group is preferably a single ring or a ring in which two rings are condensed.
The heteroaryl group is not particularly limited and preferably has a 4- to 10-membered heterocycle. The number of carbon atoms constituting the heterocycle is preferably 3 to 9. As for the hetero atom which comprises a heterocyclic ring, an oxygen atom, a nitrogen atom, and a sulfur atom are mentioned, for example. Specific examples of the heterocyclic ring include thiophene, furan, pyrrole and imidazole.

The hydrocarbon ring group in which three or more rings are condensed is not particularly limited as long as it is a hydrocarbon ring other than the above aryl group, and the hydrocarbon ring is a ring group in which three or more rings are condensed. Examples of the condensed hydrocarbon ring include a saturated aliphatic hydrocarbon ring, an unsaturated aliphatic hydrocarbon ring, and an aromatic hydrocarbon ring (benzene ring). The hydrocarbon ring is preferably a 5-membered ring or a 6-membered ring.
The hydrocarbon ring group in which three or more rings are condensed includes three or more condensed ring groups including at least one aromatic hydrocarbon ring, or 3 saturated aliphatic hydrocarbon rings or unsaturated aliphatic hydrocarbon rings. A ring group condensed with a ring or more is preferred. The number of condensed rings is not particularly limited, but is preferably 3 to 8 rings, and more preferably 3 to 5 rings.

The ring group condensed with three or more rings including at least one aromatic hydrocarbon ring is not particularly limited, and examples thereof include anthracene, phenanthracene, pyrene, tetracene, tetraphen, chrysene, triphenylene, pentacene, pentaphen, perylene, Examples thereof include a cyclic group composed of pyrene, benzo [a] pyrene, coronene, anthanthrene, corannulene, obalene, graphene, cycloparaphenylene, polyparaphenylene, or cyclophene.

The ring group in which three or more saturated aliphatic hydrocarbon rings or unsaturated aliphatic hydrocarbon rings are condensed is not particularly limited, and examples thereof include a ring group made of a compound having a steroid skeleton. Examples of the compound having a steroid skeleton include cholesterol, ergosterol, testosterone, estradiol, aldosterol, aldosterone, hydrocortisone, stigmasterol, thymosterol, lanosterol, 7-dehydrodesmosterol, 7-dehydrocholesterol, colanic acid, and chole Examples include cyclic groups composed of compounds of acid, lithocholic acid, deoxycholic acid, sodium deoxycholic acid, lithium deoxycholic acid, hyodeoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, dehydrocholic acid, hokecholic acid or hyocholic acid. .
Among the above, the hydrocarbon ring group in which three or more rings are condensed is more preferably a ring group or a pyrenyl group made of a compound having a cholesterol ring structure.

The functional group can further reinforce the binding function between the solid particles produced by the binder particles by interacting with the solid particles. This interaction is not particularly limited, but is, for example, due to a hydrogen bond, due to an acid-base ionic bond, due to a covalent bond, due to a π-π interaction due to an aromatic ring, or due to a hydrophobic-hydrophobic interaction Etc. The solid particles and the binder particles are adsorbed by one or more of the above interactions depending on the type of functional group and the type of particles described above.
When functional groups interact, the chemical structure of the functional group may or may not change. For example, in the above π-π interaction and the like, the functional group usually does not change and the structure is maintained as it is. On the other hand, in the interaction by a covalent bond or the like, the active hydrogen such as a carboxylic acid group is usually released as an anion (the functional group is changed) to bind to the inorganic solid electrolyte.

Carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, hydroxy groups, cyano groups, and alkoxysilyl groups are preferably adsorbed to the positive electrode active material and the inorganic solid electrolyte. Of these, a carboxylic acid group is particularly preferred.
For the negative electrode active material and the conductive additive, an aryl group, a heteroaryl group, and an aliphatic hydrocarbon ring group in which three or more rings are condensed are preferably adsorbed. Among them, a hydrocarbon ring group in which three or more rings are condensed is particularly preferable.

The functional group may be present in any of the main chain, side chain, or terminal of the polymer, but is more preferably introduced into the side chain or the terminal thereof.
The number of functional groups possessed by the polymer may be at least one, but is preferably two or more. Specifically, it depends on the content (mol) of the component having the functional group and the number of moles of the polymer. It is determined.
The method for introducing the functional group into the polymer is not particularly limited, and examples thereof include a method for polymerizing a compound having the functional group, a method for substituting a hydrogen atom in the polymer with the functional group, and the like.

The glass transition temperature of the polymer constituting the binder particles is preferably −100 to 80 ° C., more preferably −90 to 60 ° C., and further preferably −80 to 40 ° C. In addition, the glass transition temperature of the mixture comprising the additive, the binder particles, and the metal salt is preferably −120 to 40 ° C., more preferably −100 to 30 ° C., and further preferably −90 to 20 ° C.
This is because when the glass transition temperature is in the above range, the film strength of the sheet for an all-solid-state secondary battery of the present invention can be further improved.
In addition, the preparation method of the said mixture is mentioned later.

The glass transition temperature (Tg) is measured under the following conditions by using a differential scanning calorimeter: X-DSC7000 (trade name, manufactured by SII Nanotechnology) using binder particles or a dried sample of the above mixture. The measurement is performed twice on the same sample, and the second measurement result is adopted.
Measurement chamber atmosphere: nitrogen gas (50 mL / min)
Temperature increase rate: 5 ° C / min
Measurement start temperature: -150 ° C
Measurement end temperature: 200 ° C
Sample pan: Aluminum pan Mass of measurement sample: 5 mg
Calculation of Tg: Tg is calculated by rounding off the decimal point of the intermediate temperature between the descent start point and descent end point of the DSC chart.
In the case of using an all-solid secondary battery, for example, after disassembling the all-solid secondary battery, the active material layer or the solid electrolyte layer is placed in water to disperse the material, followed by filtration, and the remaining solid And the glass transition temperature is measured by the above-described measurement method.

The mass average molecular weight of the polymer constituting the binder particles is not particularly limited. For example, 10,000 or more are preferable, 15,000 or more are more preferable, and 20,000 or more are more preferable. As an upper limit, 1,000,000 or less is preferable, 800,000 is more preferable, and 500,000 or less is still more preferable.

-Measurement of molecular weight-
In the present invention, the molecular weight of the polymer refers to the weight average molecular weight, the molecular weight of the macromonomer refers to the number average molecular weight, and the weight average molecular weight or number average molecular weight in terms of standard polystyrene is measured by gel permeation chromatography (GPC). . The measurement method is basically a value measured by the following condition 1 or condition 2 (priority) method. However, an appropriate eluent may be selected and used depending on the polymer type.
(Condition 1)
Column: Two TOSOH TSKgel Super AWM-Hs are connected Carrier: 10 mM LiBr / N-methylpyrrolidone Measurement temperature: 40 ° C.
Carrier flow rate: 1.0 mL / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector (Condition 2) priority Column: TOSOH TSKgel Super HZM-H, TOSOH TSKgel Super HZ4000, TOSOH TSKgel Super HZ2000 connected to column Carrier: Tetrahydrofuran Measurement temperature: 40 ° C
Carrier flow rate: 1.0 mL / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector

Below, the monomer for synthesize | combining the polymer which comprises a binder particle is demonstrated. Each monomer demonstrated below may be used individually by 1 type, and may be used in combination of 2 or more type.
For the synthesis of the polymer constituting the binder particles, at least a monomer represented by the following formula (2a) is used.

Wherein (2a), ^s, R 3, ^{L 2,} and ^{L 3, s} in the formula ^(2), has the same meaning as R 3, ^{L 2,} and ^{L 3} and preferred ranges thereof are also the same.

Hereinafter, specific examples of the monomer represented by the above formula (2a) will be described, but the present invention is not limited thereto. The parentheses D-2 mean that the structure in the parentheses is a repeating unit, and the number of repetitions is 2-30.

The polymer constituting the binder particles may be synthesized from the monomer represented by the formula (2a), and may have a monomer-derived component described below as a copolymerization component. Examples of such monomer-derived components include the following monomer (c) and macromonomer.

(Monomer (c))
The monomer (c) is preferably a monomer having one polymerizable unsaturated bond, and for example, various vinyl monomers and acrylic monomers can be applied. In the present invention, it is particularly preferable to use an acrylic monomer. More preferably, a monomer selected from (meth) acrylic acid monomers, (meth) acrylic acid ester monomers, and (meth) acrylonitrile is used.

The vinyl monomer is preferably one represented by the following formula (c-1).

In the formula, R ⁷ is a hydrogen atom, an alkyl group (preferably 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 6 carbon atoms), an alkenyl group (preferably 2 to 24 carbon atoms, preferably 2 to 12 carbon atoms). More preferably, 2 to 6 are particularly preferred), an alkynyl group (preferably having 2 to 24 carbon atoms, more preferably 2 to 12, more preferably 2 to 6), or an aryl group (preferably having 6 to 22 carbon atoms, 6 To 14 are more preferable). Of these, a hydrogen atom or an alkyl group is preferable, and a hydrogen atom or a methyl group is more preferable.

R ⁸ is a hydrogen atom, an alkyl group (preferably 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 6 carbon atoms), an alkenyl group (preferably 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms). ), Aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms), aralkyl group (preferably having 7 to 23 carbon atoms, more preferably 7 to 15 carbon atoms), cyano group, carboxy group, hydroxy group, thiol Group, sulfonic acid group, phosphoric acid group, phosphonic acid group, aliphatic heterocyclic group containing oxygen atom (preferably having 2 to 12 carbon atoms, more preferably 2 to 6), or amino group (NR ^N ₂ : R ^N is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms according to the definition described later. Of these, a methyl group, ethyl group, propyl group, butyl group, cyano group, ethenyl group, phenyl group, carboxy group, sulfanyl (thiol group), sulfonic acid group and the like are preferable.
R ⁸ may further have a substituent T described later. Of these, a carboxy group, a halogen atom (fluorine atom, etc.), a hydroxy group, an alkyl group and the like may be substituted.
The carboxy group, hydroxy group, sulfonic acid group, phosphoric acid group, and phosphonic acid group may be esterified with, for example, an alkyl group having 1 to 6 carbon atoms.
The aliphatic heterocyclic group containing an oxygen atom is preferably an epoxy group-containing group, an oxetane group-containing group, a tetrahydrofuryl group-containing group, or the like.

L ⁵ is an arbitrary linking group, and examples of the linking group L described later can be given. Specifically, an alkylene group having 1 to 6 (preferably 1 to 3) carbon atoms, an alkenylene group having 2 to 6 (preferably 2 to 3) carbon atoms, and 6 to 24 (preferably 6 to 10) carbon atoms. Arylene group, oxygen atom, sulfur atom, imino group (NR ^N ), carbonyl group, phosphate linking group (—O—P (OH) (O) —O—), phosphonic acid linking group (—P (OH) ( And groups relating to O)-O-), or combinations thereof. The linking group may have an arbitrary substituent. The preferable number of connecting atoms and the number of connecting atoms are the same as described later. As an arbitrary substituent, the substituent T is mentioned, For example, an alkyl group or a halogen atom is mentioned.

M is 0 or 1.

As the acrylic monomer, in addition to the above (c-1), those represented by the following formula (c-2) or (c-3) are preferable.

R ⁷ and m are as defined in the above formula (c-1).
R ⁹ has the same meaning as R ⁸ . However, preferred examples thereof include a hydrogen atom, an alkyl group, an aryl group, a carboxy group, a thiol group, a phosphoric acid group, a phosphonic acid group, an aliphatic heterocyclic group containing an oxygen atom, and an amino group (NR ^N ₂ ). Is mentioned.
L ⁶ is an arbitrary linking group, and is preferably an example of L ⁵ , an oxygen atom, an alkylene group having 1 to 6 carbon atoms (preferably 1 to 3), or a group having 2 to 6 carbon atoms (preferably 2 to 3 carbon atoms). An alkenylene group, a carbonyl group, an imino group (NR ^N ), or a group related to a combination thereof is more preferable.
L ⁷ is a linking group, and an example of L ⁶ is preferable, and an alkylene group having 1 to 6 (preferably 1 to 3) carbon atoms is more preferable.
m represents an integer of 1 to 20, preferably an integer of 1 to 15, and more preferably an integer of 1 to 10.

In the above formulas (c-1) to (c-3), any group that may take a substituent such as an alkyl group, an aryl group, an alkylene group, or an arylene group may be substituted as long as the effects of the present invention are maintained. It may have a group. Examples of the optional substituent include a substituent T, and specifically include a halogen atom, a hydroxy group, a carboxy group, a thiol group, an acyl group, an acyloxy group, an alkoxy group, an aryloxy group, an aryloyl group, and an aryl group. You may have arbitrary substituents, such as a royloxy group and an amino group.

Examples of the monomer (c) will be given below, but the present invention is not construed as being limited thereby. V in the following formula represents 1 to 90.

(Macromonomer)
The macromonomer has a number average molecular weight of 1,000 or more, more preferably 2,000 or more, and particularly preferably 3,000 or more. The upper limit is preferably 500,000 or less, more preferably 100,000 or less, and particularly preferably 30,000 or less.

The SP value of the macromonomer is preferably 10 or less, and more preferably 9.5 or less. Although there is no particular lower limit, it is practical that it is 5 or more.

-SP value definition-
In this specification, unless otherwise specified, the SP value is obtained by the Hoy method (HL Hoy Journal of Paining, 1970, Vol. 42, 76-118). The SP value is shown with the unit omitted, but the unit is cal ^1/2 cm ^−3/2 .

The main chain of the side chain component of the macromonomer is not particularly limited, and a normal polymer component can be applied. The macromonomer preferably has a polymerizable unsaturated bond, and can have, for example, various vinyl groups or (meth) acryloyl groups. In the present invention, it is preferable to have a (meth) acryloyl group.

The macromonomer preferably contains a repeating unit derived from a monomer selected from a (meth) acrylic acid monomer, a (meth) acrylic acid ester monomer, and (meth) acrylonitrile. The macromonomer includes a polymerizable double bond and a linear hydrocarbon structural unit S having 6 or more carbon atoms (preferably an alkylene group having 6 to 30 carbon atoms, more preferably an alkylene group having 8 to 24 carbon atoms). ) Is preferably included. Thus, when the macromonomer which makes a side chain has the linear hydrocarbon structural unit S, the effect | action that the affinity with a solvent becomes high and a dispersion stability improves can be anticipated.

The above macromonomer preferably has a moiety represented by the following formula (c-11).

R ¹⁰ has the same meaning as R ⁷ . * Is a connecting part.

The above macromonomer preferably has a moiety represented by the following formulas (c-12a) to (c-12c). Hereinafter, these sites may be referred to as “specific polymerizable sites”.

R ^b2 has the same ^meaning as R ⁷ . * Is a connecting part. ^RN has the same definition as the substituent T described later. An arbitrary substituent T may be substituted on the benzene ring of the formulas (c-12c), (c-13c), and (c-14c).
The structure part present at the end of the bond part of * is not particularly limited as long as the molecular weight as a macromonomer is satisfied, but a structure part composed of a carbon atom, an oxygen atom, and a hydrogen atom is preferable. At this time, it may have a substituent T, and may have, for example, a halogen atom (fluorine atom).

The macromonomer is preferably a compound represented by the following formulas (c-13a) to (c-13c) or a compound having a repeating unit represented by (c-14a) to (c-14c). .

R ^b2 and R ^b3 have the same ^meaning as R ⁷ .

Ra represents a substituent (preferably an organic group).
Rb is a divalent linking group.
Examples of the divalent linking group include the following linking group L. Specifically, an alkane linking group having 1 to 30 carbon atoms (an alkylene group in the case of divalent), a cycloalkane linking group having 3 to 12 carbon atoms (a cycloalkylene group in the case of divalent), an aryl having 6 to 24 carbon atoms. Linking group (arylene group for divalent), heteroaryl linking group having 3 to 12 carbon atoms (heteroarylene group for divalent), ether group (—O—), sulfide group (—S—), phosphinidene group ( -PR-: R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), a silylene group (-SiRR'-: R, R 'is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), a carbonyl group, an imino group ( -NR N ^-: according R ^N is below the defined, here, a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms), or is preferably a combination thereof. Among them, an alkane linking group having 1 to 30 carbon atoms (an alkylene group in the case of divalent), an aryl linking group having 6 to 24 carbon atoms (an arylene group in the case of divalent), an ether group, a carbonyl group, or a combination thereof. It is preferable.
The linking group constituting Rb is preferably a linking structure composed of a carbon atom, an oxygen atom, and a hydrogen atom. Alternatively, the linking group constituting Rb is also preferably a structural part having a repeating unit (b-15) described later. The number of atoms constituting Rb and the number of linking atoms are as defined for the linking group L described later.

Examples of the substituent represented by Ra include examples of the substituent T described later, and among them, an alkyl group, an alkenyl group, and an aryl group are preferable. At this time, even if the linking group L is present and substituted, the linking group L may be present in the substituent.
Alternatively, Ra is preferably a structure of —Rb—Rc or a structure having a repeating unit (b-15) described later. Here, Rc includes examples of the substituent T described later, and among them, an alkyl group, an alkenyl group, and an aryl group are preferable.

At this time, each of Ra and Rb preferably contains at least a linear hydrocarbon structural unit having 1 to 30 carbon atoms (preferably an alkylene group), and preferably contains the linear hydrocarbon structural unit S. More preferred. Each of Ra to Rc may have a linking group or a substituent, and examples thereof include a linking group L and a substituent T described later.

The above macromonomer preferably further has a repeating unit represented by the following formula (c-15).

In the formula, R ^b4 is a hydrogen atom or a substituent T described later. Of these, a hydrogen atom, an alkyl group, an alkenyl group, and an aryl group are preferable. When R ^b4 is an alkyl group, an alkenyl group, or an aryl group, it may further have a substituent T described later, and may have, for example, a halogen atom or a hydroxy group.
L ⁸ is a linking group, and examples of the linking group L can be given. An ether group, a carbonyl group, an imino group, an alkylene group, an arylene group, or a combination thereof is preferable. Specific examples of the linking group relating to the combination include a linking group composed of a carbonyloxy group, an amide group, an oxygen atom, a carbon atom, and a hydrogen atom. When R ^b4 and X contain carbon, the preferred carbon number is the same as the substituent T and linking group L described later. The preferable number of constituent atoms of the linking group and the number of linking atoms are also synonymous.
In addition to the repeating unit having a polymerizable group described above, the macromonomer includes a (meth) acrylate structural unit such as the above formula b-15, and an alkylene chain which may have a halogen atom (for example, a fluorine atom) (For example, ethylene chain). At this time, an ether group (O) or the like may be present in the alkylene chain.

Examples of the substituent include a structure in which an arbitrary substituent is arranged at the terminal of the linking group. Examples of the terminal substituent include the substituent T described below, and the example of R ⁷ is preferable.

Examples of the substituent T include the following.
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), cycloalkyl A group (preferably a cycloalkyl group having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), an aryl group (preferably an aryl group having 6 to 26 carbon atoms such as phenyl, 1- Naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl, etc.), heterocyclic groups (preferably having 2 to 20 carbon atoms, preferably having at least one oxygen atom, sulfur atom, nitrogen atom) 5- or 6-membered heterocyclic groups are preferred, for example, tetrahydropyran Tetrahydrofuran, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl, etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropyloxy, etc. , Benzyloxy, etc.), aryloxy groups (preferably aryloxy groups having 6 to 26 carbon atoms, such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), alkoxycarbonyl groups (preferably carbon An alkoxycarbonyl group having 2 to 20 carbon atoms such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc., an aryloxycarbonyl group (preferably an aryloxycarbonyl group having 6 to 26 carbon atoms such as phenoxycarbonyl, 1-naphthyl Oxycarbonyl, 3-methylphenoxycarbonyl, 4-methoxyphenoxycarbonyl, etc.), amino groups (preferably containing an amino group having 0 to 20 carbon atoms, an alkylamino group, an arylamino group, such as amino, N, N— Dimethylamino, N, N-diethylamino, N-ethylamino, anilino, etc.), sulfamoyl groups (preferably sulfamoyl groups having 0 to 20 carbon atoms, such as N, N-dimethylsulfamoyl, N-phenylsulfamoyl, etc.) ), Acyl groups (including alkylcarbonyl groups, arylcarbonyl groups, and heterocyclic carbonyl groups, preferably having 1 to 20 carbon atoms, such as acetyl, propionyl, butyryl, octanoyl, hexadecanoyl, benzoyl, naphthoyl, nicotinoyl Etc.), acyloxy group (alkyl) A carbonyloxy group, an alkenylcarbonyloxy group, an alkynylcarbonyloxy group, an arylcarbonyloxy group, a heterocyclic carbonyloxy group, preferably an acyloxy group having 1 to 20 carbon atoms, such as acetyloxy, propionyloxy, butyryloxy, octanoyl Oxy, hexadecanoyloxy, acryloyloxy, methacryloyloxy, crotonoyloxy, benzoyloxy, naphthoyloxy, nicotinoyloxy, etc.), aryloyloxy group (preferably an aryloyloxy group having 7 to 23 carbon atoms, for example, Benzoyloxy, etc.), carbamoyl groups (preferably carbamoyl groups having 1 to 20 carbon atoms such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl etc.), acylamino groups (preferably carbon 1-20 acylamino groups (eg, acetylamino, benzoylamino, etc.), alkylthio groups (preferably alkylthio groups having 1-20 carbon atoms, eg, methylthio, ethylthio, isopropylthio, benzylthio, etc.), arylthio groups (preferably carbon An arylthio group having 6 to 26, for example, phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc., an alkylsulfonyl group (preferably an alkylsulfonyl group having 1 to 20 carbon atoms, for example, methylsulfonyl) , Ethylsulfonyl, etc.), arylsulfonyl groups (preferably arylsulfonyl groups having 6 to 22 carbon atoms such as benzenesulfonyl), alkylsilyl groups (preferably alkylsilyl groups having 1 to 20 carbon atoms such as monomethylsilyl, Zimechi Silyl, trimethylsilyl, triethylsilyl, etc.), arylsilyl groups (preferably arylsilyl groups having 6 to 42 carbon atoms such as triphenylsilyl), phosphoryl groups (preferably phosphoric acid groups having 0 to 20 carbon atoms such as, for example, -OP (= O) (R ^P ) ₂ ), a phosphonyl group (preferably a phosphonyl group having 0 to 20 carbon atoms, such as -P (= O) (R ^P ) ₂ ), a phosphinyl group (preferably having 0 carbon atoms). To 20 phosphinyl groups such as —P (R ^P ) ₂ ), sulfo group (sulfonic acid group), hydroxy group, sulfanyl group, cyano group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom, etc.) ).
In addition, each of the groups listed as the substituent T may be further substituted with the above-described substituent T.

When the compound, substituent, linking group and the like include an alkyl group, an alkylene group, an alkenyl group, an alkenylene group, an alkynyl group and / or an alkynylene group, these may be cyclic or linear, and may be linear or branched. It may be substituted as described above or unsubstituted.

Each substituent defined in the present specification may be substituted through the following linking group L within the scope of the effects of the present invention, or the linking group L may be present in the structure thereof. For example, an alkyl group, an alkylene group, an alkenyl group, and an alkenylene group may further have the following hetero-linking group interposed in the structure.

The linking group L includes a hydrocarbon linking group [an alkylene group having 1 to 10 carbon atoms (more preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an alkenylene group having 2 to 10 carbon atoms (more preferably carbon atoms). 2 to 6, more preferably 2 to 4), an alkynylene group having 2 to 10 carbon atoms (more preferably 2 to 6, more preferably 2 to 4 carbon atoms), and an arylene group having 6 to 22 carbon atoms (more preferably Is a carbon number 6-10)], hetero linking group [carbonyl group (—CO—), thiocarbonyl group (—CS—), ether group (—O—), thioether group (—S—), imino group (— NR ^N —), imine linking group (R ^N —N═C <, —N═C (R ^N ) —), sulfonyl group (—SO ₂ —), sulfinyl group (—SO—), phosphate linking group ( -OP (OH) (O) -O-), phosphonic acid Yuimoto (-P (OH) (O) -O -), 2-valent heterocyclic group], or a linking group is preferably a combination thereof. In addition, when condensing and forming a ring, the said hydrocarbon coupling group may form the double bond and the triple bond suitably, and may connect. The ring to be formed is preferably a 5-membered ring or a 6-membered ring. As the five-membered ring, a nitrogen-containing five-membered ring is preferable, and examples of the compound forming the ring include pyrrole, imidazole, pyrazole, indazole, indole, benzimidazole, pyrrolidine, imidazolidine, pyrazolidine, indoline, carbazole, or these And derivatives thereof. Examples of the 6-membered ring include piperidine, morpholine, piperazine, and derivatives thereof. When an aryl group, a heterocyclic group, or the like is included, they may be monocyclic or condensed, and may be similarly substituted or unsubstituted.

R ^N represents a hydrogen atom or a substituent, the substituent is the same as defined indicated above substituent T. Examples of the substituent include an alkyl group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, more preferably 1 to 6 and particularly preferably 1 to 3), and an alkenyl group (preferably having 2 to 24 carbon atoms and 2 carbon atoms). To 12 is more preferable, 2 to 6 is more preferable, and 2 to 3 is particularly preferable, and an alkynyl group (2 to 24 carbon atoms is preferable, 2 to 12 is more preferable, 2 to 6 is more preferable, and 2 to 3 is Particularly preferred), an aralkyl group (preferably 7 to 22 carbon atoms, more preferably 7 to 14 carbon atoms, particularly preferably 7 to 10 carbon atoms), an aryl group (preferably 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms, 6 to 10 is particularly preferred).

^RP is a hydrogen atom, a hydroxy group, or a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, more preferably 1 to 6 and particularly preferably 1 to 3), and an alkenyl group (preferably having 2 to 24 carbon atoms and 2 carbon atoms). To 12 is more preferable, 2 to 6 is more preferable, and 2 to 3 is particularly preferable, and an alkynyl group (2 to 24 carbon atoms is preferable, 2 to 12 is more preferable, 2 to 6 is more preferable, and 2 to 3 is Particularly preferred), an aralkyl group (preferably 7 to 22 carbon atoms, more preferably 7 to 14 carbon atoms, particularly preferably 7 to 10 carbon atoms), an aryl group (preferably 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms, 6 to 10 is particularly preferred), an alkoxy group (preferably having a carbon number of 1 to 24, more preferably 1 to 12, more preferably 1 to 6, and particularly preferably 1 to 3), an alkenyloxy group (having a carbon number of To 24, more preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 3, and an alkynyloxy group (preferably 2 to 24 carbon atoms, more preferably 2 to 12 carbon atoms, and 2 to 6 carbon atoms). More preferably, 2 to 3 are particularly preferred), an aralkyloxy group (preferably 7 to 22 carbon atoms, more preferably 7 to 14 carbon atoms, particularly preferably 7 to 10 carbon atoms), an aryloxy group (preferably 6 to 22 carbon atoms, 6 to 14 are more preferable, and 6 to 10 are particularly preferable.

In the present specification, the number of atoms constituting the linking group is preferably from 1 to 36, more preferably from 1 to 24, still more preferably from 1 to 12, and from 1 to 6 Is particularly preferred. The number of linking atoms in the linking group is preferably 10 or less, and more preferably 8 or less. The lower limit is 1 or more. The number of connected atoms refers to the minimum number of atoms that are located in a path connecting predetermined structural parts and are involved in connection. For example, in the case of —CH ₂ —C (═O) —O—, the number of atoms constituting the linking group is 6, but the number of linking atoms is 3.

Specific combinations of linking groups include the following. Oxycarbonyl group (—OCO—), carbonate group (—OCOO—), amide group (—CONH—), urethane group (—NHCOO—), urea group (—NHCONH—), (poly) alkyleneoxy group (— ( Lr-O) x-), carbonyl (poly) oxyalkylene group (-CO- (O-Lr) x-, carbonyl (poly) alkyleneoxy group (-CO- (Lr-O) x-), carbonyloxy ( Poly) alkyleneoxy group (—COO— (Lr—O) x—), (poly) alkyleneimino group (— (Lr—NR ^N ) x—), alkylene (poly) iminoalkylene group (—Lr— (NR ^N -lr) x-), carbonyl (poly) iminoalkylene group ^{(-CO- (NR N -Lr) x-} ), carbonyl (poly) alkyleneimino group (-CO- (Lr-NR ^N x-), (poly) ester group (— (CO—O—Lr) x—, — (O—CO—Lr) x—, — (O—Lr—CO) x—, — (Lr—CO—O) ) X-,-(Lr-O-CO) x-), (poly) amide group (-(CO-NR ^N -Lr) x-,-(NR ^N -CO-Lr) x-,-(NR ^N -Lr-CO) x-,-(Lr-CO-NR ^N ) x-,-(Lr-NR ^N -CO) x-), etc. x is an integer of 1 or more, preferably 1 to 500 1 to 100 is more preferable.

Lr is preferably an alkylene group, an alkenylene group or an alkynylene group. The carbon number of Lr is preferably 1 to 12, more preferably 1 to 6, and particularly preferably 1 to 3. A plurality of Lr, R ^N , R ^P , x, etc. need not be the same. The direction of the linking group is not limited by the above description, and may be understood as appropriate according to a predetermined chemical formula.

As the macromonomer, a macromonomer having an ethylenically unsaturated bond at the terminal may be used. Here, the macromonomer is composed of a polymer chain portion and a polymerizable functional group portion having an ethylenically unsaturated double bond at the terminal thereof.

In the present invention, the average particle size of the polymer constituting the binder particles is preferably 1 nm to 10 μm, more preferably 10 nm to 1 μm, and even more preferably 20 nm to 600 nm.
In the present invention, the average particle diameter of the polymer constituting the binder particles is the volume average particle diameter measured in the same manner as the average particle diameter of the inorganic solid electrolyte.
In addition, the measurement from the produced all-solid-state secondary battery is, for example, after the battery is disassembled and the electrode is peeled off, and the measurement is performed in accordance with the method of measuring the particle diameter of the polymer constituting the binder particles for the electrode material. And the measurement of the particle diameter of the polymer constituting the binder particles, which has been measured in advance, is eliminated.

The polymer constituting the binder particles preferably contains 0.1 to 60% by mass, more preferably 0.3 to 40% by mass of the component derived from the monomer represented by the formula (2a), 0.5% More preferably, the content is ˜20% by mass. The polymer constituting the binder particles preferably contains 0 to 99.9% by mass of the component derived from the monomer (c), more preferably 20 to 95% by mass, and even more preferably 40 to 90% by mass. . The polymer constituting the binder particles preferably contains 0.5 to 60% by mass of a component derived from a macromonomer, more preferably 1 to 50% by mass, and even more preferably 2 to 40% by mass.

The polymer constituting the binder particles can be synthesized with reference to, for example, JP-A-2015-88486 and JP-A-2015-164125.
In the present invention, the polymer constituting the binder particles preferably has a metal salt inside the polymer. Taking binder particles (P-1), which will be described later, as an example, “having a metal salt inside the polymer” means that a cation derived from the metal salt is present in the poly (ethyleneoxy) chain. It means that it is adsorbed by electronic interaction.
The polymer can be obtained by a method of mixing with a metal salt after synthesis, a method of polymerizing in the presence of a metal salt, or the like.

The binder particles preferably contain 80% by mass or more of the polymer, more preferably 90% by mass or more, still more preferably 95% by mass or more, and may be 100% by mass.
In addition to the above polymer, a polymer other than the polymer having the partial structure represented by the formula (2) may be included as a polymer constituting the binder particles as long as the effects of the present invention are not impaired.

<Dispersion medium>
The solid electrolyte composition of the present invention contains a dispersion medium (dispersion medium).
The dispersion medium only needs to disperse each of the above components, and examples thereof include various organic solvents. Examples of the organic solvent include alcohol solvents, ether compounds, amide compounds, amine compounds, ketone compounds, aromatic compounds, aliphatic compounds, nitrile compounds, ester compounds, and the like. However, the said additive is not contained in an alcohol compound, an ether compound, and an ester compound.
Specific examples of the dispersion medium include the following.

Examples of the alcohol compound include methyl alcohol.

Examples of ether compounds include diethyl ether and anisole.

Examples of the amide compound include N, N-dimethylformamide, N-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidinone, ε-caprolactam, formamide, N- Examples include methylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropanamide, hexamethylphosphoric triamide and the like.

Examples of the amine compound include triethylamine, diisopropylethylamine, tributylamine and the like.
Examples of the ketone compound include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.
Examples of the aromatic compound include benzene, toluene, xylene and the like.
Examples of the aliphatic compound include hexane, heptane, octane, decane and the like.
Examples of the nitrile compound include acetonitrile, propylonitrile, isobutyronitrile, and the like.
Examples of the ester compound include ethyl acetate, butyl acetate, propyl acetate, butyl butyrate, and butyl pentanoate.
Examples of the non-aqueous dispersion medium include the above aromatic compounds and aliphatic compounds.

In the present invention, among them, amine compounds, ether compounds, ketone compounds, aromatic compounds, and aliphatic compounds are preferable, and ether compounds, aromatic compounds, and aliphatic compounds are more preferable. In the present invention, it is preferable to further select the specific organic solvent using a sulfide-based inorganic solid electrolyte. By selecting this combination, the functional group active for the sulfide-based inorganic solid electrolyte is not included, so that the sulfide-based inorganic solid electrolyte can be handled stably, which is preferable.

The dispersion medium preferably has a boiling point of 50 ° C. or higher, more preferably 70 ° C. or higher at normal pressure (1 atm). The upper limit is preferably 250 ° C. or lower, and more preferably 220 ° C. or lower.
The said dispersion medium may be used individually by 1 type, or may be used in combination of 2 or more type.

In the present invention, the content of the dispersion medium in the solid electrolyte composition is not particularly limited and can be appropriately set. For example, in the solid electrolyte composition, 20 to 99% by mass is preferable, 25 to 70% by mass is more preferable, and 30 to 60% by mass is particularly preferable.

<Active material>
The solid electrolyte composition of the present invention may contain an active material capable of inserting and releasing metal ions belonging to Group 1 or Group 2 of the Periodic Table. As described below, the active material includes a positive electrode active material and a negative electrode active material. A transition metal oxide (preferably a transition metal oxide) that is a positive electrode active material or a metal oxide that is a negative electrode active material Or the metal which can form an alloy with lithium, such as Sn, Si, Al, and In, is preferable.
In the present invention, a solid electrolyte composition containing an active material (positive electrode active material or negative electrode active material) is sometimes referred to as an electrode composition (positive electrode composition or negative electrode composition).

(Positive electrode active material)
The positive electrode active material that may be contained in the solid electrolyte composition of the present invention is preferably one that can reversibly insert and / or release lithium ions. The material is not particularly limited as long as it has the above characteristics, and may be a transition metal oxide or an element that can be complexed with Li such as sulfur.
Among these, as the positive electrode active material, it is preferable to use a transition metal oxide, and a transition metal oxide having a transition metal element M ^a (one or more elements selected from Co, Ni, Fe, Mn, Cu, and V). More preferred. In addition, this transition metal oxide includes an element M ^b (an element of the first (Ia) group of the metal periodic table other than lithium, an element of the second (IIa) group, Al, Ga, In, Ge, Sn, Pb, Elements such as Sb, Bi, Si, P and B) may be mixed. The mixing amount is preferably 0 ~ 30 mol% relative to the amount of the transition metal element ^{M a (100mol%).} That the molar ratio of li / ^{M a} was synthesized were mixed so that 0.3 to 2.2, more preferably.
Specific examples of the transition metal oxide include (MA) a transition metal oxide having a layered rock salt structure, (MB) a transition metal oxide having a spinel structure, (MC) a lithium-containing transition metal phosphate compound, (MD And lithium-containing transition metal halogenated phosphate compounds and (ME) lithium-containing transition metal silicate compounds.

(MA) As specific examples of the transition metal oxide having a layered rock salt structure, LiCoO ₂ (lithium cobaltate [LCO]), LiNi ₂ O ₂ (lithium nickelate), LiNi _0.85 Co _0.10 Al _{0. 05} O ₂ (nickel cobalt lithium aluminum oxide [NCA]), LiNi _1/3 Co _1/3 Mn _1/3 O ₂ (nickel manganese lithium cobalt oxide [NMC]), LiNi _0.5 Mn _0.5 O ₂ ( Lithium manganese nickelate).
As specific examples of transition metal oxides having (MB) spinel structure, LiMn ₂ O ₄ (LMO), LiCoMnO _4, Li ₂ FeMn ₃ O ₈ , Li ₂ CuMn ₃ O ₈ , Li ₂ CrMn ₃ O ₈ and Li ₂ NiMn ₃ O ₈ is mentioned.
Examples of (MC) lithium-containing transition metal phosphate compounds include olivine-type iron phosphate salts such as LiFePO ₄ and Li ₃ Fe ₂ (PO ₄ ) ₃ , iron pyrophosphates such as LiFeP ₂ O ₇ , LiCoPO _{4, and the} like. And monoclinic Nasicon type vanadium phosphate salts such as Li ₃ V ₂ (PO ₄ ) ₃ (vanadium lithium phosphate).
(MD) as the lithium-containing transition metal halogenated phosphate compound, for _example, Li 2 FePO ₄ F such fluorinated phosphorus iron _salt, Li 2 MnPO ₄ hexafluorophosphate manganese salts such as F and _Li 2 CoPO ₄ F Cobalt fluorophosphates such as
Examples of the (ME) lithium-containing transition metal silicate compound include Li ₂ FeSiO ₄ , Li ₂ MnSiO ₄ , and Li ₂ CoSiO ₄ .
In the present invention, a transition metal oxide having a (MA) layered rock salt structure is preferable, and LCO or NMC is more preferable.

The shape of the positive electrode active material is not particularly limited, but is preferably particulate. The volume average particle diameter (sphere conversion average particle diameter) of the positive electrode active material is not particularly limited. For example, the thickness can be 0.1 to 50 μm. In order to make the positive electrode active material have a predetermined particle size, an ordinary pulverizer or classifier may be used. The positive electrode active material obtained by the firing method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent. The volume average particle diameter (sphere-converted average particle diameter) of the positive electrode active material particles can be measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (trade name, manufactured by HORIBA).

The positive electrode active material may be used alone or in combination of two or more.
When forming a positive electrode active material layer, the mass (mg) (weight per unit area) of the positive electrode active material per unit area (cm ² ) of the positive electrode active material layer is not particularly limited. It can be determined as appropriate according to the designed battery capacity, for example, 1 to 100 mg / cm ² .

The content of the positive electrode active material in the solid electrolyte composition is not particularly limited, and is preferably 10 to 97% by mass, more preferably 30 to 95% by mass, in a total of 100% by mass of the additive and the total solid content. It is more preferably 40 to 93% by mass, particularly preferably 50 to 90% by mass.

(Negative electrode active material)
The negative electrode active material that may be contained in the solid electrolyte composition of the present invention is preferably one that can reversibly insert and / or release lithium ions. The material is not particularly limited as long as it has the above characteristics, and is a carbonaceous material, a metal oxide such as tin oxide, a silicon oxide, a metal composite oxide, a lithium simple substance or a lithium alloy such as a lithium aluminum alloy, and , Sn, Si, Al, In, and other metals capable of forming an alloy with lithium. Among these, a carbonaceous material or a lithium composite oxide is preferably used from the viewpoint of reliability. Further, the metal composite oxide is preferably capable of inserting and extracting lithium. The material is not particularly limited, but preferably contains titanium and / or lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics.

The carbonaceous material used as the negative electrode active material is a material substantially made of carbon. For example, various synthetics such as petroleum pitch, carbon black such as acetylene black (AB), graphite (natural graphite, artificial graphite such as vapor-grown graphite), PAN (polyacrylonitrile) resin or furfuryl alcohol resin, etc. The carbonaceous material which baked resin can be mentioned. Furthermore, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA (polyvinyl alcohol) -based carbon fiber, lignin carbon fiber, glassy carbon fiber, and activated carbon fiber. And mesophase microspheres, graphite whiskers, flat graphite and the like.

These carbonaceous materials can be divided into non-graphitizable carbonaceous materials and graphite-based carbonaceous materials according to the degree of graphitization. The carbonaceous material preferably has a face spacing or density and crystallite size described in JP-A-62-222066, JP-A-2-6856, and 3-45473. The carbonaceous material does not have to be a single material, and a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, or the like is used. You can also.

As the metal oxide and metal composite oxide applied as the negative electrode active material, an amorphous oxide is particularly preferable, and chalcogenite which is a reaction product of a metal element and a group 16 element of the periodic table is also preferably used. It is done. The term “amorphous” as used herein means an X-ray diffraction method using CuKα rays, which has a broad scattering band having a peak in the region of 20 ° to 40 ° in terms of 2θ, and is a crystalline diffraction line. You may have. The strongest intensity of crystalline diffraction lines seen from 2 ° to 40 ° to 70 ° is 100 times the diffraction line intensity at the peak of the broad scattering band seen from 2 ° to 20 °. It is preferable that it is 5 times or less, and it is particularly preferable not to have a crystalline diffraction line.

Among the compound group consisting of the above amorphous oxide and chalcogenide, an amorphous oxide of a metalloid element and a chalcogenide are more preferable, and elements of Groups 13 (IIIB) to 15 (VB) of the periodic table, Al , Ga, Si, Sn, Ge, Pb, Sb and Bi are used alone or in combination of two or more thereof, and chalcogenides are particularly preferable. Specific examples of preferable amorphous oxides and chalcogenides include, for example, Ga ₂ O ₃ , SiO, GeO, SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₈ Bi ₂ O ₃ , Sb ₂ O ₈ Si ₂ O ₃ , Bi ₂ O ₄ , SnSiO ₃ , GeS, SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ and SnSiS ₃ are preferred. Moreover, these may be a complex oxide with lithium oxide, for example, Li ₂ SnO ₂ .

It is also preferable that the negative electrode active material contains a titanium atom. More specifically, Li ₄ Ti ₅ O ₁₂ (lithium titanate [LTO]) is excellent in rapid charge / discharge characteristics due to small volume fluctuations during occlusion and release of lithium ions, and the deterioration of the electrodes is suppressed, and lithium ion secondary. This is preferable in that the battery life can be improved.

In the present invention, hard carbon or graphite is preferably used, and graphite is more preferably used. In the present invention, the carbonaceous materials may be used singly or in combination of two or more.

In the present invention, it is also preferable to apply a Si-based negative electrode. In general, a Si negative electrode can occlude more Li ions than a carbon negative electrode (such as graphite and acetylene black). That is, the amount of occlusion of Li ions per unit mass increases. Therefore, the battery capacity can be increased. As a result, there is an advantage that the battery driving time can be extended.

The chemical formula of the compound obtained by the above firing method can be calculated from an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method, and from a mass difference between powders before and after firing as a simple method.

Examples of the negative electrode active material that can be used in combination with the amorphous oxide negative electrode active material centering on Sn, Si, and Ge include carbon materials that can occlude and / or release lithium ions or lithium metal, lithium, lithium alloys, A metal that can be alloyed with lithium is preferable.

The shape of the negative electrode active material is not particularly limited, but is preferably particulate. The average particle size of the negative electrode active material is preferably 0.1 to 60 μm. In order to obtain a predetermined particle size, an ordinary pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill or a sieve is preferably used. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle diameter, classification is preferably performed. There is no restriction | limiting in particular as a classification method, A sieve, an air classifier, etc. can be used as needed. Classification can be used both dry and wet. The average particle diameter of the negative electrode active material particles can be measured by the same method as the above-described method for measuring the volume average particle diameter of the positive electrode active material.

The said negative electrode active material may be used individually by 1 type, or may be used in combination of 2 or more type.
When forming the negative electrode active material layer, the mass (mg) (weight per unit area) of the negative electrode active material per unit area (cm ² ) of the negative electrode active material layer is not particularly limited. It can be determined as appropriate according to the designed battery capacity, for example, 1 to 100 mg / cm ² .

The content of the negative electrode active material in the solid electrolyte composition is not particularly limited, and is preferably 10 to 90% by mass, and 20 to 85% by mass in a total of 100% by mass of the additive and the total solid content. More preferably, it is 30 to 80% by mass, and further preferably 40 to 75% by mass.

(Coating with active material)
The surfaces of the positive electrode active material and the negative electrode active material may be coated with another metal oxide. Examples of the surface coating agent include metal oxides containing Ti, Nb, Ta, W, Zr, Al, Si, or Li. Specific examples include spinel titanate, tantalum-based oxides, niobium-based oxides, lithium niobate-based compounds, and the like. Specific examples include Li ₄ Ti ₅ O ₁₂ , Li ₂ Ti ₂ O ₅ , LiTaO _3. , LiNbO ₃ , LiAlO ₂ , Li ₂ ZrO ₃ , Li ₂ WO ₄ , Li ₂ TiO ₃ , Li ₂ B ₄ O ₇ , Li ₃ PO ₄ , Li ₂ MoO ₄ , Li ₃ BO ₃ , LiBO ₂ , Li ₂ CO ₃ , Li ₂ SiO ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , B ₂ O _{3 and the} like.
Moreover, the electrode surface containing a positive electrode active material or a negative electrode active material may be surface-treated with sulfur or phosphorus.
Furthermore, the particle surface of the positive electrode active material or the negative electrode active material may be subjected to surface treatment with actinic rays or an active gas (plasma or the like) before and after the surface coating.

<Conductive aid>
The solid electrolyte composition of the present invention may contain a conductive auxiliary agent used for improving the electronic conductivity of the active material, if necessary. As the conductive auxiliary agent, a general conductive auxiliary agent can be used. For example, graphites such as natural graphite and artificial graphite, carbon blacks such as acetylene black, ketjen black and furnace black, amorphous carbon such as needle coke, vapor-grown carbon fiber or carbon nanotube, which are electron conductive materials Carbon fibers such as graphene, carbonaceous materials such as graphene or fullerene, metal powders such as copper and nickel, and metal fibers may be used, and conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyphenylene derivatives May be used. Moreover, 1 type of these may be used and 2 or more types may be used.
When the solid electrolyte composition of the present invention contains a conductive auxiliary agent, the content of the conductive auxiliary agent in the solid electrolyte composition exceeds 10% by mass in a total of 100% by mass of the additive and the total solid content and exceeds 10% by mass. The following is preferred.

(Preparation of solid electrolyte composition)
The solid electrolyte composition of the present invention is preferably prepared as a slurry by mixing additives, metal salts, binder particles, and a dispersion medium, and optionally other components, for example, using various mixers. Can be prepared.
The mixing method is not particularly limited, and may be mixed in a lump or may be mixed sequentially, and the additive, a metal salt, a dispersion liquid in which binder particles and a dispersion medium are mixed, and if necessary, mixed with other components. Can be prepared.
Although it does not restrict | limit especially as a mixer, For example, a ball mill, bead mill, a planetary mixer, a blade mixer, a roll mill, a kneader, and a disk mill are mentioned. The mixing conditions are not particularly limited. For example, the mixing temperature is set to 10 to 60 ° C., the mixing time is set to 5 minutes to 5 hours, and the rotation speed is set to 10 to 700 rpm (rotation per minute). When a ball mill is used as the mixer, it is preferable to set the rotational speed at 150 to 700 rpm and the mixing time at 5 minutes to 24 hours at the mixing temperature. In addition, it is preferable that the compounding quantity of each component is set so that it may become the said content.
The environment for mixing is not particularly limited, and examples thereof include dry air or inert gas.

[All-solid-state secondary battery sheet]
The sheet for an all-solid-state secondary battery of the present invention is a sheet-like molded body that can form a constituent layer of the all-solid-state secondary battery, and includes various modes depending on the application. For example, a sheet preferably used for a solid electrolyte layer (also referred to as a solid electrolyte sheet for an all-solid secondary battery), an electrode, or a sheet preferably used for a laminate of an electrode and a solid electrolyte layer (an electrode for an all-solid secondary battery) Sheet) and the like. In the present invention, these various sheets may be collectively referred to as an all-solid secondary battery sheet.

The layer composed of the solid electrolyte composition of the present invention constituting the all-solid-state secondary battery sheet of the present invention contains 100 ppm or more of the above additive on a mass basis when heated at 200 ° C. for 6 hours under 1 atm. 300 ppm or more is preferable, and 500 ppm or more is more preferable. Although there is no restriction | limiting in particular in an upper limit, 20 mass% or less is practical, and 10 mass% or less is preferable.
The content of the additive in the layer can be obtained by extracting the additive with a coating solvent or the like from the layer constituted by the solid electrolyte composition of the present invention and quantifying the additive by liquid chromatography.

The solid electrolyte sheet for an all-solid-state secondary battery according to the present invention may be a sheet having a solid electrolyte layer. The sheet | seat currently formed from may be sufficient. The solid electrolyte sheet for an all-solid-state secondary battery may have other layers as long as it has a solid electrolyte layer. Examples of other layers include a protective layer (release sheet), a current collector, and a coat layer.
Examples of the solid electrolyte sheet for an all-solid-state secondary battery of the present invention include a sheet having a solid electrolyte layer and, if necessary, a protective layer in this order on a substrate.
The base material is not particularly limited as long as it can support the solid electrolyte layer, and examples thereof include materials described later with reference to current collectors, sheet materials (plate bodies) of organic materials, inorganic materials, and the like. Examples of the organic material include various polymers, and specific examples include polyethylene terephthalate, polypropylene, polyethylene, and cellulose. Examples of the inorganic material include glass and ceramic.

The configuration and layer thickness of the solid electrolyte layer of the all-solid-state secondary battery sheet are the same as the configuration and layer thickness of the solid electrolyte layer described in the all-solid-state secondary battery of the present invention.

The electrode sheet for an all-solid-state secondary battery of the present invention (also simply referred to as “electrode sheet of the present invention”) may be an electrode sheet having an active material layer, and the active material layer is on the substrate (current collector). Even the sheet | seat formed in this may be a sheet | seat formed from an active material layer, without having a base material. This electrode sheet is usually a sheet having a current collector and an active material layer, but an embodiment having a current collector, an active material layer, and a solid electrolyte layer in this order, and a current collector, an active material layer, and a solid electrolyte The aspect which has a layer and an active material layer in this order is also included. The electrode sheet of the present invention may have the other layers described above as long as it has an active material layer. The layer thickness of each layer constituting the electrode sheet of the present invention is the same as the layer thickness of each layer described in the all-solid secondary battery described later.

[Manufacture of sheets for all-solid-state secondary batteries]
The method for producing the all-solid-state secondary battery sheet of the present invention is not particularly limited, and can be produced by forming each of the above layers using the solid electrolyte composition of the present invention. For example, a method of forming a layer (coating / drying layer) made of a solid electrolyte composition by forming a film (coating / drying) on a base material or a current collector (may be provided with another layer) if necessary. Can be mentioned. Thereby, the sheet | seat for all-solid-state secondary batteries which has a base material or an electrical power collector, and a coating dry layer as needed can be produced. Here, the coating and drying layer is a layer formed by applying the solid electrolyte composition of the present invention and drying the dispersion medium (that is, using the solid electrolyte composition of the present invention, and the solid of the present invention. A layer having a composition obtained by removing the dispersion medium from the electrolyte composition).
In the method for producing an all-solid-state secondary battery sheet of the present invention, each step such as coating and drying will be described in the following method for producing an all-solid-state secondary battery.

In the method for producing an all-solid-state secondary battery sheet of the present invention, the coating / drying layer obtained as described above can be pressurized. The pressurizing condition and the like will be described later in the method for manufacturing an all-solid secondary battery.
Moreover, in the manufacturing method of the sheet | seat for all-solid-state secondary batteries of this invention, a base material, a protective layer (especially peeling sheet), etc. can also be peeled.

The all-solid-state secondary battery sheet according to the present invention has at least one of a solid electrolyte layer and an active material layer formed of the solid electrolyte composition of the present invention, and effectively suppresses an increase in interfacial resistance between solid particles. Solid particles are firmly bound together. Therefore, it is suitably used as a sheet that can form a constituent layer of an all-solid-state secondary battery. In particular, when a sheet for an all-solid-state secondary battery is produced in a long line (even if it is wound during conveyance) and used as a wound battery, bending stress is applied to the solid electrolyte layer and the active material layer. Even if it acts, the binding state of the solid particles in the solid electrolyte layer and the active material layer can be maintained. When an all-solid-state secondary battery is manufactured using the sheet for an all-solid-state secondary battery manufactured by such a manufacturing method, high productivity and yield (reproducibility) can be realized while maintaining excellent battery performance.

[All-solid secondary battery]
An all solid state secondary battery of the present invention comprises a positive electrode active material layer, a negative electrode active material layer facing the positive electrode active material layer, and a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer. Have. The positive electrode active material layer is formed on the positive electrode current collector as necessary to constitute a positive electrode. The negative electrode active material layer is formed on the negative electrode current collector as necessary to constitute the negative electrode.
At least one of the negative electrode active material layer, the positive electrode active material layer, and the solid electrolyte layer is preferably formed of the solid electrolyte composition of the present invention. Among them, all the layers are formed of the solid electrolyte composition of the present invention. More preferably. In addition, a well-known material can be used when an active material layer or a solid electrolyte layer is not formed with the solid electrolyte composition of this invention.
The thicknesses of the negative electrode active material layer, the solid electrolyte layer, and the positive electrode active material layer are not particularly limited. The thickness of each layer is preferably 10 to 1,000 μm, more preferably 20 μm or more and less than 500 μm, considering the dimensions of a general all solid state secondary battery. In the all solid state secondary battery of the present invention, it is more preferable that the thickness of at least one of the positive electrode active material layer and the negative electrode active material layer is 50 μm or more and less than 500 μm.
Each of the positive electrode active material layer and the negative electrode active material layer may include a current collector on the side opposite to the solid electrolyte layer.

[Case]
The all-solid-state secondary battery of the present invention may be used as an all-solid-state secondary battery with the above-mentioned structure depending on the application. Is preferred. The housing may be metallic or made of resin (plastic). In the case of using a metallic material, for example, an aluminum alloy or a stainless steel material can be used. The metallic housing is preferably divided into a positive-side housing and a negative-side housing and electrically connected to the positive current collector and the negative current collector, respectively. The casing on the positive electrode side and the casing on the negative electrode side are preferably joined and integrated via a gasket for preventing a short circuit.

Hereinafter, an all-solid secondary battery according to a preferred embodiment of the present invention will be described with reference to FIG. 1, but the present invention is not limited thereto.

FIG. 1 is a cross-sectional view schematically showing an all solid state secondary battery (lithium ion secondary battery) according to a preferred embodiment of the present invention. The all-solid-state secondary battery 10 of this embodiment has a negative electrode current collector 1, a negative electrode active material layer 2, a solid electrolyte layer 3, a positive electrode active material layer 4, and a positive electrode current collector 5 in this order as viewed from the negative electrode side. . Each layer is in contact with each other and has an adjacent structure. By adopting such a structure, at the time of charging, electrons (e ⁻ ) are supplied to the negative electrode side, and lithium ions (Li ⁺ ) are accumulated therein. On the other hand, at the time of discharge, lithium ions (Li ⁺ ) accumulated in the negative electrode are returned to the positive electrode side, and electrons are supplied to the working part 6. In the illustrated example, a light bulb is adopted as a model for the operating part 6 and is lit by discharge.

When the all-solid-state secondary battery having the layer configuration shown in FIG. 1 is placed in a 2032 type coin case, this all-solid-state secondary battery is referred to as an all-solid-state secondary battery laminate, A battery produced by placing it in a 2032 type coin case may be referred to as an all-solid secondary battery.

(Positive electrode active material layer, solid electrolyte layer, negative electrode active material layer)
In the all-solid-state secondary battery 10, all of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer are formed of the solid electrolyte composition of the present invention. This all-solid-state secondary battery 10 has a small electric resistance and exhibits excellent battery performance. The additive, metal salt, inorganic solid electrolyte, and binder particles contained in the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 may be the same or different from each other.
In the present invention, either or both of the positive electrode active material layer and the negative electrode active material layer may be simply referred to as an active material layer or an electrode active material layer. One or both of the positive electrode active material and the negative electrode active material may be simply referred to as an active material or an electrode active material.

In the present invention, when the additive, metal salt, and binder particles are used in combination with solid particles such as an inorganic solid electrolyte or an active material, the interfacial resistance between the solid particles is increased, and the interfacial resistance between the solid particles and the current collector is increased. The rise can be suppressed. Furthermore, contact failure between the solid particles and peeling (peeling) of the solid particles from the current collector can be suppressed. Therefore, the all solid state secondary battery of the present invention exhibits excellent battery characteristics. In particular, the all-solid-state secondary battery of the present invention using the above-described binder particles capable of binding solid particles or the like is manufactured as described above, for example, a sheet for an all-solid-state secondary battery or an all-solid-state secondary battery. Excellent battery characteristics can be maintained even if bending stress acts in the process.

In the all-solid-state secondary battery 10, the negative electrode active material layer can be a lithium metal layer. Examples of the lithium metal layer include a layer formed by depositing or molding lithium metal powder, a lithium foil, a lithium vapor deposition film, and the like. Regardless of the thickness of the negative electrode active material layer, the thickness of the lithium metal layer can be, for example, 1 to 500 μm.

The positive electrode current collector 5 and the negative electrode current collector 1 are preferably electronic conductors.
In the present invention, either or both of the positive electrode current collector and the negative electrode current collector may be simply referred to as a current collector.
Materials for forming the positive electrode current collector include aluminum, aluminum alloy, stainless steel, nickel, and titanium, as well as aluminum or stainless steel surface treated with carbon, nickel, titanium, or silver (forming a thin film) Among them, aluminum and aluminum alloys are more preferable.
In addition to aluminum, copper, copper alloy, stainless steel, nickel, titanium, etc., the material for forming the negative electrode current collector is treated with carbon, nickel, titanium, or silver on the surface of aluminum, copper, copper alloy, or stainless steel. What was made to do is preferable, and aluminum, copper, a copper alloy, and stainless steel are more preferable.

The current collector is usually in the form of a film sheet, but a net, a punched one, a lath, a porous body, a foam, a fiber group molded body, or the like can also be used.
The thickness of the current collector is not particularly limited, but is preferably 1 to 500 μm. Moreover, it is also preferable that the current collector surface is roughened by surface treatment.

In the present invention, a functional layer, a member, or the like is appropriately interposed or disposed between or outside each of the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector. May be. Each layer may be composed of a single layer or a plurality of layers.

[Manufacture of all-solid-state secondary batteries]
The all solid state secondary battery can be manufactured by a conventional method. Specifically, an all-solid secondary battery can be manufactured by forming each of the above layers using the solid electrolyte composition of the present invention. Thereby, an all-solid-state secondary battery having a small electric resistance and excellent battery performance can be manufactured. Details will be described below.

The all-solid-state secondary battery of the present invention includes a step of applying the solid electrolyte composition of the present invention on a base material (for example, a metal foil serving as a current collector) to form a film (forming a film). It can be manufactured via the (intermediate) method (method for manufacturing the sheet for an all-solid-state secondary battery of the present invention).
For example, a solid electrolyte composition containing a positive electrode active material is applied as a positive electrode material (positive electrode composition) on a metal foil that is a positive electrode current collector to form a positive electrode active material layer. A positive electrode sheet for a battery is prepared. Next, a solid electrolyte composition for forming a solid electrolyte layer is applied on the positive electrode active material layer to form a solid electrolyte layer. Furthermore, a solid electrolyte composition containing a negative electrode active material is applied as a negative electrode material (negative electrode composition) on the solid electrolyte layer to form a negative electrode active material layer. An all-solid-state secondary battery having a structure in which a solid electrolyte layer is sandwiched between a positive electrode active material layer and a negative electrode active material layer is obtained by stacking a negative electrode current collector (metal foil) on the negative electrode active material layer. Can do. If necessary, this can be enclosed in a housing to obtain a desired all-solid secondary battery.
Moreover, the formation method of each layer is reversed, and a negative electrode active material layer, a solid electrolyte layer, and a positive electrode active material layer are formed on the negative electrode current collector, and the positive electrode current collector is stacked to produce an all-solid secondary battery. You can also

Another method includes the following method. That is, a positive electrode sheet for an all-solid secondary battery is produced as described above. Further, a negative electrode active material layer is formed by applying a solid electrolyte composition containing a negative electrode active material as a negative electrode material (negative electrode composition) on a metal foil that is a negative electrode current collector, and forming an all-solid secondary A negative electrode sheet for a battery is prepared. Next, a solid electrolyte layer is formed on one of the active material layers of these sheets as described above. Furthermore, the other of the positive electrode sheet for an all solid secondary battery and the negative electrode sheet for an all solid secondary battery is laminated on the solid electrolyte layer so that the solid electrolyte layer and the active material layer are in contact with each other. In this way, an all-solid secondary battery can be manufactured.
Another method includes the following method. That is, as described above, a positive electrode sheet for an all-solid secondary battery and a negative electrode sheet for an all-solid secondary battery are produced. Separately from this, a solid electrolyte composition is applied onto a substrate to produce a solid electrolyte sheet for an all-solid secondary battery comprising a solid electrolyte layer. Furthermore, it laminates | stacks so that the solid electrolyte layer peeled off from the base material may be pinched | interposed with the positive electrode sheet for all-solid-state secondary batteries, and the negative electrode sheet for all-solid-state secondary batteries. In this way, an all-solid secondary battery can be manufactured.

An all-solid-state secondary battery can also be manufactured by a combination of the above forming methods. For example, as described above, a positive electrode sheet for an all-solid secondary battery, a negative electrode sheet for an all-solid secondary battery, and a solid electrolyte sheet for an all-solid secondary battery are produced. Then, after laminating the solid electrolyte layer peeled off from the base material on the negative electrode sheet for an all solid secondary battery, an all solid secondary battery can be produced by pasting the positive electrode sheet for the all solid secondary battery. it can. In this method, the solid electrolyte layer can be laminated on the positive electrode sheet for an all-solid secondary battery, and bonded to the negative electrode sheet for an all-solid secondary battery.
In the above production method, the solid electrolyte composition of the present invention may be used for any one of the positive electrode composition, the solid electrolyte composition, and the negative electrode composition. It is preferable to use it.

<Formation of each layer (film formation)>
The method for applying the solid electrolyte composition is not particularly limited and can be appropriately selected. Examples thereof include coating (preferably wet coating), spray coating, spin coating coating, dip coating, slit coating, stripe coating, and bar coating coating.
At this time, the solid electrolyte composition may be dried after being applied, or may be dried after being applied in multiple layers. The drying temperature is not particularly limited. The lower limit is preferably 30 ° C or higher, more preferably 60 ° C or higher, and still more preferably 80 ° C or higher. The upper limit is preferably 300 ° C. or lower, more preferably 250 ° C. or lower, and even more preferably 200 ° C. or lower. By heating in such a temperature range, a dispersion medium can be removed and it can be set as a solid state (coating dry layer). Further, it is preferable because the temperature is not excessively raised and each member of the all-solid-state secondary battery is not damaged. Thereby, in the all-solid-state secondary battery, excellent overall performance can be obtained, and good binding properties and good ionic conductivity can be obtained even without pressure.

As described above, when the solid electrolyte composition of the present invention is applied and dried, a coating / drying layer in which the interfacial resistance between the solid particles is small and the solid particles are firmly bound can be formed.

It is preferable to pressurize each layer or all-solid secondary battery after producing the applied solid electrolyte composition or all-solid secondary battery. Moreover, it is also preferable to pressurize in the state which laminated | stacked each layer. An example of the pressurizing method is a hydraulic cylinder press. The applied pressure is not particularly limited and is generally preferably in the range of 50 to 1500 MPa.
Moreover, you may heat the apply | coated solid electrolyte composition simultaneously with pressurization. The heating temperature is not particularly limited, and is generally in the range of 30 to 300 ° C. It is also possible to press at a temperature higher than the glass transition temperature of the inorganic solid electrolyte. On the other hand, when the inorganic solid electrolyte and binder particles coexist, pressing can be performed at a temperature higher than the glass transition temperature of the polymer forming the binder particles. However, it is generally a temperature that does not exceed the melting point of the polymer.
The pressurization may be performed in a state where the coating solvent or the dispersion medium is previously dried, or may be performed in a state where the solvent or the dispersion medium remains.
In addition, each composition may be apply | coated simultaneously and application | coating drying press may be performed simultaneously and / or sequentially. You may laminate | stack by transfer after apply | coating to a separate base material.

The atmosphere during pressurization is not particularly limited, and may be any of the following: air, dry air (dew point -20 ° C. or lower), inert gas (for example, argon gas, helium gas, nitrogen gas).
The pressing time may be a high pressure in a short time (for example, within several hours), or a medium pressure may be applied for a long time (1 day or more). In the case of an all-solid-state secondary battery other than the all-solid-state secondary battery sheet, for example, a restraining tool (screw tightening pressure or the like) of the all-solid-state secondary battery can be used in order to keep applying moderate pressure.
The pressing pressure may be uniform or different with respect to the pressed part such as the sheet surface.
The pressing pressure can be changed according to the area or film thickness of the pressed part. Also, the same part can be changed stepwise with different pressures.
The press surface may be smooth or roughened.

<Initialization>
The all solid state secondary battery manufactured as described above is preferably initialized after manufacture or before use. The initialization is not particularly limited, and can be performed, for example, by performing initial charging / discharging in a state where the press pressure is increased, and then releasing the pressure until the general operating pressure of the all-solid secondary battery is reached.

[Use of all-solid-state secondary batteries]
The all solid state secondary battery of the present invention can be applied to various uses. Although there are no particular restrictions on the application mode, for example, when installed in an electronic device, a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone, a pager, a handy terminal, a mobile fax machine, a mobile phone Copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini-disc, electric shaver, transceiver, electronic notebook, calculator, memory card, portable tape recorder, radio, backup power supply, etc. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, and shoulder grinders). Furthermore, it can be used for various military use and space use. Moreover, it can also combine with a solar cell.

Hereinafter, the present invention will be described in more detail based on examples. The present invention is not construed as being limited thereby. In the following examples, “part” and “%” representing the composition are based on mass unless otherwise specified. In the present invention, “room temperature” means 25 ° C.

-Synthesis of Macromonomer M-1-
Macromonomer M-1 was synthesized as follows.
190 parts by mass of toluene was added to a 1 L three-necked flask equipped with a reflux condenser and a gas introduction cock, and nitrogen gas was introduced at a flow rate of 200 mL / min for 10 minutes, followed by heating to 80 ° C. The liquid (the following prescription α) prepared in a separate container was dropped into a 1 L three-necked flask over 2 hours and stirred at 80 ° C. for 2 hours. Thereafter, an additional 0.2 g of radical polymerization initiator V-601 (trade name, manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred at 95 ° C. for 2 hours. 0.025 parts by mass of 2,2,6,6-tetramethylpiperidine-1-oxyl (manufactured by Tokyo Chemical Industry Co., Ltd.) and glycidyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) were added to the solution kept at 95 ° C. after stirring. 13 parts by mass and 2.5 parts by mass of tetrabutylammonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) were added and stirred at 120 ° C. for 3 hours. The resulting mixture was cooled to room temperature and then added to methanol for precipitation. The precipitate was collected by filtration, washed twice with methanol, and dissolved by adding 300 parts by mass of heptane. A portion of the resulting solution was distilled off under reduced pressure to obtain a solution of macromonomer M-1 represented by the chemical formula described below. The weight average molecular weight was 16,000.

(Prescription α)
Dodecyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 150 parts by mass Methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 59 parts by mass 3-mercaptopropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 2 parts by mass V-601 (Wako Pure Chemical Industries, Ltd.) 2.0 parts by mass)

-Synthesis of Macromonomer M-2-
In the synthesis of macromonomer M-1, dodecyl methacrylate was changed to 2-ethylhexyl methacrylate, methyl methacrylate was changed to propyl methacrylate, and polymerization initiator V-601 was changed to dicumyl peroxide (manufactured by Aldrich). Except for the above, a solution of macromonomer M-2 was obtained in the same manner. The weight average molecular weight was 13,000.

(Synthesis of binder particles P-1)
After adding 30 parts by mass of macromonomer M-1 and 160 parts by mass of heptane to a 1 L three-necked flask equipped with a reflux condenser and a gas introduction cock, nitrogen gas was introduced at a flow rate of 200 mL / min for 10 minutes and then 80 parts. The temperature was raised to ° C. A liquid prepared in a separate container (prescription β below) was added dropwise thereto over 2 hours, and then stirred at 80 ° C. for 2 hours. Thereafter, an additional 2.0 g of V-601 was added to the resulting mixture and stirred at 90 ° C. for 2 hours. A dispersion of binder particles (acrylic latex) P-1 was obtained. The polymer constituting the binder particle P-1 had a mass average molecular weight of 77,000, an average particle size of 180 nm, and the glass transition temperature of the binder particle P-1 obtained by drying the dispersion liquid was −55 ° C.

(Prescription β)
64 parts by mass of the exemplified compound C-16 (poly (ethylene glycol) methyl ether methacrylate (manufactured by Aldrich))
6 parts by mass of the exemplified compound D-1 (diethylene glycol dimethacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.))
V-601 2.6 parts by mass

The chemical formula of the polymer constituting the binder particle P-1 is shown below.

(Synthesis of binder particles P-2 to P-23)
Dispersions of binder particles P-2 to P-23 were prepared in the same manner as binder particle P-1, except that the composition was changed to the composition shown in Table 1 below.

<Notes on the table>
Amount: part by mass molecular weight: mass average molecular weight particle size: average particle size (nm)
Tg: Glass transition temperature of polymer constituting binder particles M-3: Macromonomer AB-6 (trade name, manufactured by Toa Gosei Co., Ltd.)
D-14: Polybutadiene-terminated diacrylate, trade name BAC-45 (manufactured by Osaka Organic Chemical Industry Co., Ltd.)

(Preparation of mixture ABP-1)
160 parts by mass of heptane was added to a 1 L three-necked flask equipped with a reflux condenser and a gas introduction cock. A dispersion of binder particles P-1 was added to a 1 L three-neck flask so that the solid content was 80 parts by mass, and the mixture was stirred at room temperature for 1 hour. Thereafter, 11.8 parts by mass of Additive A-2 (Diglyme (Aldrich)) and 8.2 parts by mass of metal salt B-2 (lithium bisfluorosulfonium imide (Kishida Chemical Co., Ltd.)) The mixture was stirred at room temperature for 2 hours to obtain a dispersion of a mixture ABP-1 containing binder particles, an additive, and a metal salt. The glass transition temperature of the mixture ABP-1 obtained by drying the obtained dispersion was -65 ° C.

(Preparation of mixtures ABP-2 to ABP-24-1, CP-1 and CP-2)
Dispersions of mixtures ABP-2 to ABP-24-1, CP-1 and CP-2 were prepared in the same manner as the mixture ABP-1, except that the composition was changed to the composition shown in Table 2 below.

<Notes on the table>
Amount: part by mass Tg: glass transition temperature of the mixture PEO: polyethylene oxide EC: ethylene carbonate A-5: polyethylene glycol 2000 (manufactured by Wako Pure Chemical Industries) Number average molecular weight 2,000
Mw / Mn = 1-2

(Synthesis of sulfide inorganic solid electrolyte (Li-PS glass))
Sulfide-based inorganic solid electrolytes are disclosed in T.W. Ohtomo, A .; Hayashi, M .; Tatsumisago, Y. et al. Tsuchida, S .; Hama, K .; Kawamoto, Journal of Power Sources, 233, (2013), pp231-235 and A.K. Hayashi, S .; Hama, H .; Morimoto, M .; Tatsumisago, T .; Minami, Chem. Lett. , (2001), pp 872-873.

Specifically, in a glove box under an argon atmosphere (dew point −70 ° C.), 2.42 g of lithium sulfide (Li ₂ S, manufactured by Aldrich, purity> 99.98%), diphosphorus pentasulfide (P ₂ S ₅ , 3.90 g manufactured by Aldrich, purity> 99%) was weighed, put into an agate mortar, and mixed for 5 minutes using an agate mortar. Incidentally, Li ₂ S and _P 2 _{S 5} at a molar ratio of _{Li 2 S: P 2 S 5} = 75: was 25.
66 zirconia beads having a diameter of 5 mm were introduced into a 45 mL container (made by Fritsch) made of zirconia, the whole mixture of the above lithium sulfide and diphosphorus pentasulfide was introduced, and the container was sealed under an argon atmosphere. A container is set on a planetary ball mill P-7 (trade name) manufactured by Frichtu, and mechanical milling is performed at a temperature of 25 ° C. and a rotation speed of 510 rpm for 20 hours to obtain a yellow powder sulfide-based inorganic solid electrolyte (Li-PS system). 6.20 g of glass) was obtained.

<Preparation of solid electrolyte composition S-1>
A zirconia 45 mL container (manufactured by Fritsch) was charged with 180 pieces of zirconia beads having a diameter of 5 mm, 4.85 g of the Li—PS glass prepared above, and the dispersion ABP-1 of the mixture was equivalent to the solid content. 0.15 g and 8.0 g of heptane as a dispersion medium were added. A container was set in the planetary ball mill P-7, and mixing was continued for 60 minutes at a temperature of 25 ° C. and a rotation speed of 250 rpm to prepare a solid electrolyte composition S-1.

<Preparation of solid electrolyte compositions S-2 to 24 and T-1 to T-3>
Solid electrolyte compositions S-2 to S-24-1 and T-1 to T-3 were prepared in the same manner as the solid electrolyte composition S-1, except that the composition was changed to the composition shown in Table 3 below.

<Notes on the table>
LPS: Li—PS system glass LLZ: Li ₇ La ₃ Zr ₂ O ₁₂

<Preparation of positive electrode sheet>
180 pieces of zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, 1.9 g of the solid electrolyte composition prepared above was added in an amount corresponding to the solid content, and 12.3 g of heptane as a total amount of the dispersion medium. . NMC (LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (manufactured by Aldrich)) 8.0 g and acetylene black 0.1 g as an active material are put into a container, and the container is set in a planetary ball mill P-7. Then, mixing was continued for 30 minutes at a temperature of 25 ° C. and a rotational speed of 200 rpm to prepare a positive electrode composition CE-1.

The positive electrode composition CE-1 prepared above was applied to an aluminum foil having a thickness of 20 μm as a current collector using an applicator (trade name: SA-201 Baker type applicator, manufactured by Tester Sangyo Co., Ltd.), and 1 at 80 ° C. After heating for an hour, it was further dried at 110 ° C. for 1 hour. Then, using a heat press machine, it pressurized (20 Mpa, 1 minute), heating (120 degreeC), and produced the positive electrode sheet CE-1 which has a laminated structure of a positive electrode active material layer / aluminum foil.

Positive electrode sheets CE-2 to CE-24 and CC-1 to CC-3 were prepared in the same manner as the positive electrode sheet CE-1, except that the composition of the positive electrode composition was changed to the composition shown in Table 4 below.

<Preparation of negative electrode sheet>
Negative electrode sheets AE-1 to AE- were prepared in the same manner as the positive electrode sheet CE-1, except that a negative electrode composition having the composition shown in Table 4 below was prepared and used instead of the positive electrode composition CE-1. 4, CA-1 and CA-2 were prepared.
In all cases, stainless steel foil was used as a current collector.

<Preparation of solid electrolyte sheet for all-solid-state secondary battery>
The solid electrolyte composition S-1 prepared above was applied onto an aluminum foil having a thickness of 20 μm used as a support by an applicator (trade name: SA-201 Baker type applicator, manufactured by Tester Sangyo Co., Ltd.), and at 80 ° C. After heating for 1 hour, it was further dried at 110 ° C. for 1 hour to produce a solid electrolyte sheet EE-1.

Solid electrolyte sheet EE- for an all-solid-state secondary battery in the same manner as the solid electrolyte sheet EE-1 for an all-solid-state secondary battery, except that the composition of the solid electrolyte composition and the conductive additive is changed to the composition shown in Table 4 below. 2 to EE-4 were prepared.

The positive electrode sheets CE-1 to CE-24, the negative electrode sheets AE-1 to AE-4, and the solid electrolyte sheets EE-1 to EE-4 for all-solid-state secondary batteries are heated at 1 atm. Thus, it was confirmed that the solid electrolyte layer, the positive electrode active material layer, or the negative electrode active material layer included in each sheet contains 100 ppm or more of the additive.

<Membrane strength test>
A bending resistance test (based on JIS K5600-5-1 (1999)) using a mandrel tester was performed. From each sheet, a strip-shaped test piece having a width of 50 mm and a length of 100 mm was cut out. The solid electrolyte layer surface or the active material layer surface was set on the side opposite to the mandrel, bent using a mandrel having a diameter of 32 mm, the solid electrolyte layer surface or the active material layer surface was observed, and the presence or absence of cracks and cracks was observed. When no cracks or cracks occur and the solid electrolyte layer surface or active material layer surface is not peeled off from the substrate, the diameter (unit: mm) of the mandrel is 25, 20, 16, 12, 10, 8, 6, 5, The diameter of the mandrel at which cracks, cracks or peeling occurred first was recorded. The evaluation criteria are shown below. Rank C or higher is the passing level of this test.

-Evaluation criteria-
A: Mandrel diameter 5 mm or less B: Mandrel diameter 6 mm or 8 mm
C: Mandrel diameter 10 mm
D: Mandrel diameter 12 mm or 16 mm
E: Mandrel diameter 20 mm or 25 mm
F: Mandrel diameter 32 mm

<Notes on the table>
LCO: LiCoO ₂ (manufactured by Aldrich)
NMC: LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (manufactured by Aldrich)
Si: Silicon powder AB: Acetylene black (Denka Black (trade name), manufactured by Denka)
VGCF: Vapor growth carbon fiber (Showa Denko)

As is apparent from Table 4, the positive electrode sheets CC-1 to CC-3 and the negative electrode sheets CA-1 and CA-2 that do not satisfy the provisions of the present invention all have inferior film strength. On the other hand, manufactured from the solid electrolyte composition of the present invention containing the additive represented by the formula (1) and the binder particles containing the polymer having the partial structure represented by the formula (2) in combination. The positive electrode sheet, the negative electrode sheet, and the solid electrolyte sheet for an all-solid-state secondary battery are found to have excellent film strength (CE-1 to CE-24, AE-1 to AE-4, and EE-1 to EE-4). ).

<Manufacture of all-solid-state secondary batteries>
The negative electrode sheet AE-1 produced above was subjected to a bending test using a mandrel having a diameter of 10 mm three times, and then the solid electrolyte composition (S-1) prepared above was applied onto the negative electrode active material layer. After heating at 80 ° C. for 1 hour, it was further dried at 110 ° C. for 6 hours. The sheet having the solid electrolyte layer formed on the negative electrode active material layer was pressurized (30 MPa, 1 minute) while being heated (120 ° C.) using a heat press machine, and the solid electrolyte layer / negative electrode active material layer / stainless foil A sheet having a laminated structure was produced.

This sheet was cut into a disk shape having a diameter of 15 mm. On the other hand, the positive electrode sheet CE-1 for an all-solid-state secondary battery prepared above was subjected to a bending test using a mandrel having a diameter of 10 mm three times, and then cut into a disk shape having a diameter of 13 mm. After arranging the positive electrode active material layer of the positive electrode sheet and the solid electrolyte layer to face each other, using a heat press machine, pressurizing (40 MPa, 1 minute) while heating (120 ° C.), aluminum foil / positive electrode active material layer A laminate for an all-solid-state secondary battery having a laminated structure of / solid electrolyte layer / negative electrode active material layer / stainless foil was produced.

Please refer to FIG.
The all-solid-state secondary battery laminate 12 thus produced is put into a stainless steel 2032 type coin case 11 incorporating a spacer and a washer (not shown in FIG. 2), and the 2032 type coin case 11 is caulked. No. 101 all-solid-state secondary battery 13 was produced.
Except for employing the configuration shown in Table 5 below, In the same manner as the all-solid secondary battery 101, an all-solid secondary battery shown in Table 5 was produced.
After the following discharge capacity density measurement and resistance evaluation test were conducted, the all-solid-state secondary battery laminate was taken out from the coin case, and the above method was used for No. 4 It was confirmed that each constituent layer of the all-solid secondary batteries 101 to 123 contained 100 ppm or more of the additive.

[Measurement of discharge capacity density]
The all-solid secondary battery produced above was measured with a charge / discharge evaluation apparatus “TOSCAT-3000” (trade name) manufactured by Toyo System. The all solid state secondary battery was charged at a current value of 0.2 mA until the battery voltage reached 4.2 V, and then discharged at a current value of 0.2 mA until the battery voltage reached 3.0 V. This charging / discharging was made into 1 cycle. This cycle was repeated, and the discharge capacity at the third cycle was defined as the discharge capacity of the all-solid-state secondary battery. This discharge capacity was converted to the discharge capacity when the positive electrode area was 100 cm ² . In addition, the discharge capacity of 110 mAh or more is a passing level of this test.

[Evaluation of resistance]
The all-solid secondary battery produced above was measured with a charge / discharge evaluation apparatus “TOSCAT-3000” (trade name) manufactured by Toyo System. The all solid state secondary battery was charged at a current value of 0.2 mA until the battery voltage reached 4.2 V, and then discharged at a current value of 2.0 mA until the battery voltage reached 3.0 V. The battery voltage 10 seconds after the start of discharge was read according to the following criteria to evaluate the resistance. A higher battery voltage indicates a lower resistance. The evaluation criteria are shown below. Rank C or higher is the passing level of this test.

-Evaluation criteria-
A: 4.15 V or more A: 4.1 V or more, less than 4.15 V B: 4.0 V or more, less than 4.1 V C: 3.8 V or more, less than 4.0 V D: 3.6 V or more, less than 3.8 V E: Less than 3.6V

As can be seen from Table 5, the all-solid-state secondary battery without the all-solid-state secondary battery sheet produced from the solid electrolyte composition of the present invention has high resistance and inferior battery voltage (c01- c03). In contrast, the all-solid-state secondary battery having the all-solid-state secondary battery sheet manufactured from the solid electrolyte composition of the present invention has low resistance and excellent battery voltage (101 to 123).

While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

This application claims priority based on Japanese Patent Application No. 2018-081670 filed in Japan on April 20, 2018, the contents of which are hereby incorporated by reference. Capture as part.

DESCRIPTION OF SYMBOLS 1 Negative electrode collector 2 Negative electrode active material layer 3 Solid electrolyte layer 4 Positive electrode active material layer 5 Positive electrode collector 6 Actuation site 10 All-solid secondary battery 11 Coin case 12 Laminated body 13 for all-solid secondary battery All-solid secondary Battery (coin battery)

Claims (16)

Conductivity of an additive represented by the following formula (1), a salt of a metal belonging to Group 1 or 2 of the periodic table, and an ion of a metal belonging to Group 1 or 2 of the periodic table A solid electrolyte composition comprising an inorganic solid electrolyte, binder particles containing a polymer having a partial structure represented by the following formula (2), and a dispersion medium.

In formula (1), R ¹ and R ² represent a hydrogen atom, an alkyl group, an aryl group, or an acyl group. n represents an integer of 1 or more. X represents an alkylene group, an arylene group, —O—, —S— or a single bond. R ¹ and R ² may combine with each other to form a ring.
L ¹ represents an alkylene group or an arylene group. Y represents an alkylene group, an arylene group, —O—, —S—, —N (Rs) —, —P (═O) (ORt) —, —C (═O) —, —C (═S) —. Or a divalent linkage in which at least two groups selected from —O—, —S—, —N (Rs) —, —P (═O) (ORt) —, and C (═O) — are combined. Indicates a group. Here, Rs and Rt are a hydrogen atom, an alkyl group, or an aryl group. When n is an integer of 2 or more, the repeating parts of -L ¹ -Y- may be the same as or different from each other.

In the formula (2), s represents an integer of 2 to 20. R ³ represents a hydrogen atom or an alkyl group. L ² represents — (CH ₂ ) _t — or —C (═O) —, and t represents an integer of 0 to 10. L ³ represents an s-valent linking group containing at least one of an oxygen atom and a nitrogen atom. Wherein the carbon atoms constituting L ² binds to the oxygen atom or nitrogen atom constituting L ^3. The solid electrolyte composition according to claim 1, wherein the additive has a molecular weight of less than 10,000. The solid electrolyte composition according to claim 1 or 2, wherein the ratio of the additive to the metal salt is additive: metal salt = 1: 0.1 to 0.1: 1 by mass ratio. . The solid electrolyte composition according to any one of claims 1 to 3, wherein the polymer has at least one structure represented by the following formula (3).

In formula (3), R ⁵ represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and * represents a bonding part. The solid electrolyte composition according to any one of claims 1 to 4, wherein the polymer has at least one structure represented by the following formula (4).

In formula (4), L ⁴ represents a single bond or a divalent linking group, and R ⁶ represents a hydrogen atom, a halogen atom, an alkyl group or an aryl group. * Indicates a connecting part. 6. The solid electrolyte composition according to claim 1, wherein the polymer has a glass transition temperature of −100 to 80 ° C. The glass transition temperature of the mixture comprising the additive, the binder particles, and the metal salt contained in the solid electrolyte composition is -120 to 40 ° C according to any one of claims 1 to 6. Solid electrolyte composition. The solid electrolyte composition according to any one of claims 1 to 7, wherein the polymer has at least one functional group selected from the following functional group group.
[Functional group group]
An acidic functional group, a basic functional group, a hydroxy group, a cyano group, an alkoxysilyl group, an aryl group, a heteroaryl group, a hydrocarbon ring group in which three or more rings are condensed. The solid electrolyte composition according to any one of claims 1 to 8, wherein the metal salt is contained inside the polymer. The solid electrolyte composition according to any one of claims 1 to 9, wherein the inorganic solid electrolyte is a sulfide-based inorganic solid electrolyte. The solid electrolyte composition according to any one of claims 1 to 10, comprising an active material. An all-solid secondary battery sheet having a layer composed of the solid electrolyte composition according to any one of claims 1 to 11. The sheet for an all-solid-state secondary battery according to claim 12, wherein the layer contains the additive in an amount of 100 ppm or more on a mass basis when heated at 200 ° C for 6 hours under 1 atmosphere. An all solid state secondary battery comprising a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order,
The all-solid secondary, wherein at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is a layer composed of the solid electrolyte composition according to any one of claims 1 to 11. battery. A method for producing a sheet for an all-solid-state secondary battery, wherein the solid electrolyte composition according to any one of claims 1 to 11 is formed. A method for producing an all-solid-state secondary battery, wherein the all-solid-state secondary battery is produced through the production method according to claim 15.

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