WO2021210604A1

WO2021210604A1 - Binder composition for nonaqueous secondary battery, composition for electrode, electrode sheet, nonaqueous secondary battery, and methods for producing said electrode sheet and said nonaqueous secondary battery

Info

Publication number: WO2021210604A1
Application number: PCT/JP2021/015432
Authority: WO
Inventors: 智則三村; 郁雄木下; 歌穂森; 景河野; 一樹瀧本
Original assignee: 富士フイルム株式会社; 富士フイルム和光純薬株式会社
Priority date: 2020-04-15
Filing date: 2021-04-14
Publication date: 2021-10-21
Also published as: JP2023106633A

Abstract

Provided are: a binder composition for nonaqueous secondary batteries which includes a binder constituted of a polymer having a component including a betaine structure; a composition for electrodes which comprises said binder composition and an electrode active material; an electrode sheet including a layer constituted of said composition for electrodes; a method for producing the electrode sheet; a nonaqueous secondary battery including a positive-electrode active material layer and a negative-electrode active material layer, wherein at least one of the layers is a layer constituted of said composition for electrodes; and a method for producing the nonaqueous secondary battery.

Description

Binder composition for non-aqueous secondary battery, composition for electrode, electrode sheet, non-aqueous secondary battery, and method for manufacturing these electrode sheet and non-aqueous secondary battery.

The present invention relates to a binder composition for a non-aqueous secondary battery, a composition for an electrode, an electrode sheet, a non-aqueous secondary battery, a method for producing an electrode sheet, and a method for producing a non-aqueous secondary battery.

Non-aqueous secondary batteries represented by lithium-ion secondary batteries are used as a power source for portable electronic devices such as personal computers, video cameras, and mobile phones. Recently, against the background of the global environmental issue of reducing carbon dioxide emissions, it has become widespread as a power source for transportation equipment such as automobiles, and as a power storage application for nighttime electric power and electric power generated by renewable energy power generation.

The electrodes (positive electrode and negative electrode) of the lithium ion secondary battery have an electrode active material layer (positive electrode active material layer and negative electrode active material layer), and this electrode active material layer can store or release lithium ions during charging and discharging. Contains electrode active material particles. Further, since electron transport is also performed between the electrode active material particles or between the electrode active material particles and the current collector, it is required to ensure electron conductivity. The binding property between the electrode active material particles or between the electrode active material particles and the current collector is important for improving the efficiency of electron conduction, and the electrode active material layer usually has a binder. However, the binder itself has a low electron transporting ability, and the improvement of the binding property and the improvement of the electron conductivity usually have a so-called trade-off relationship with each other.

The electrodes of a lithium ion secondary battery are usually formed by applying a composition (slurry) for forming an electrode onto a current collector and drying it. Therefore, the slurry for forming the electrode is prepared by dispersing the electrode active material and the binder in the liquid medium. Against the background of growing interest in environmental issues in recent years, water-based liquid media have been required, and water-based binders suitable for water-based slurries have been developed.
For example, Patent Document 1 contains 50 to 80% by mass of structural units derived from an ethylenically unsaturated carboxylic acid ester monomer and 20 to 50% by mass of structural units derived from an ethylenically unsaturated carboxylic acid ester monomer. , It is described that a water-soluble polymer having a specific viscosity is used as an aqueous electrode binder for a secondary battery.
Further, Patent Document 2 describes an ethylenically unsaturated monomer which may contain a phosphate group-containing ethylenically unsaturated monomer, a surfactant which may contain a phosphate group-containing surfactant, and a surfactant. Described is an aqueous dispersion type binder for a non-aqueous battery electrode, which is obtained by emulsion polymerization of a composition containing at least one neutralizing agent selected from an alkali metal and an alkaline earth metal.

In order to realize further increase in capacity of lithium ion secondary batteries, studies on using a silicon-based active material as a negative electrode active material are being actively conducted. High energy density can be achieved by using a silicon-based active material for the negative electrode. However, the silicon-based active material occludes a large amount of lithium ions during charging and expands significantly, and the contraction width of the silicon-based active material during discharging also increases accordingly. Therefore, a lithium ion battery using a silicon-based active material as the negative electrode active material has a large volume change of the negative electrode active material during charging and discharging, and the battery performance tends to deteriorate due to repeated charging and discharging. That is, there are restrictions on improving the cycle life.
As a technique for dealing with such a problem, for example, Patent Document 3 describes a negative electrode active material containing 20% by mass or more of silicon particles having a median diameter of 0.1 to 2 μm, a (meth) acrylamide skeleton-containing monomer, and a sulfonic acid. A slurry for the negative electrode of a lithium ion battery, which is a radical copolymer of a group of monomers containing a group-substituted unsaturated hydrocarbon group-containing monomer and contains poly (meth) acrylamide showing a specific viscosity in an aqueous solution state of a specific concentration and water. Is described. According to the technique described in Patent Document 3, it is said that the dispersibility of the slurry can be improved, the electrode formed by the slurry has excellent flexibility, and a lithium ion secondary battery having a long cycle life can be obtained.

Japanese Unexamined Patent Publication No. 2015-1877 Japanese Patent No. 6462125 JP-A-2018-6334

With the expansion of applications for non-aqueous secondary batteries, non-aqueous secondary batteries are required to have higher energy density, lower resistance, and further improvement in cycle life. However, as a result of studies on conventional electrode binders including the electrode binders described in the above patent documents, the present inventors have used a silicon-based active material as the negative electrode active material and have a high energy density of a non-aqueous secondary battery. It has become clear that it is difficult to sufficiently suppress the battery resistance and that the cycle life has not reached the desired high level.

According to the present invention, a composition (slurry) having excellent dispersibility of these solid particles can be obtained by mixing with solid particles such as an electrode active material and a conductive additive, and the electrode activity can be obtained by using this composition. By forming a material layer, the binding property between the electrode active material particles or between the electrode active material particles and the current collector can be sufficiently enhanced, and the electrode active material having a large volume change during charging and discharging can be used as an electrode. For non-aqueous secondary batteries, the resistance of the non-aqueous secondary battery obtained even when used in the active material layer can be sufficiently reduced, and the cycle life of this non-aqueous secondary battery can be sufficiently extended. An object of the present invention is to provide a binder composition. Another object of the present invention is to provide an electrode composition in which the binder composition and the electrode active material are combined, an electrode sheet using the electrode composition, and a non-aqueous secondary battery. A further object of the present invention is to provide a method for manufacturing the electrode sheet and the non-aqueous secondary battery.

In view of the above problems, the present inventors have repeated various studies on the polymer structure constituting the binder. As a result, when the binder composition containing the aqueous polymer having the constituent component containing the betaine structure in the aqueous medium is mixed with the solid particles such as the electrode active material and the conductive auxiliary agent, the aggregation of the solid particles is suppressed. A composition in which solid particles are sufficiently dispersed in a small particle size can be obtained, and if an electrode active material layer is formed using this composition, the electrode active material particles can be separated from each other or between the electrode active material particles and the current collector. By sufficiently enhancing the bondability between the electrodes and incorporating the electrode containing the electrode active material layer into the non-aqueous secondary battery, the resistance of the obtained non-aqueous secondary battery can be effectively suppressed. We also found that the cycle life can be extended sufficiently. The present invention has been further studied based on these findings and has been completed.

That is, the above problem was solved by the following means.
<1>
A binder composition for a non-aqueous secondary battery, which comprises a binder composed of a polymer having a constituent component containing a betaine structure.
<2>
The non-aqueous secondary battery according to <1>, wherein the polymer has a component having at least one salt structure of a carboxylate, a sulfonate, a phosphate, a phosphonate, a nitrate and an ammonium salt. Binder composition.
<3>
The non-described in <2>, wherein the salt structure is at least one of a carboxylate, a sulfonate, a phosphate, a phosphonate, and a nitrate, and the salt structure has a counterion derived from a polyvalent amine. Binder composition for water secondary batteries.
<4>
<1> to <3>, in which the swelling rate of the polymer is 1% or more and less than 200% with respect to a solvent in which ethylene carbonate and ethyl methyl carbonate are mixed in a mass ratio of ethylene carbonate / ethyl methyl carbonate = 1/2. The binder composition for a non-aqueous secondary battery according to any one of the above.
<5>
The binder composition for a non-aqueous secondary battery according to any one of <1> to <4>, wherein the polymer has a constituent component represented by the following formula (O-31).

In the formula, R ³¹ to R ³³ independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group having 1 to 24 carbon atoms.
R ³⁴ represents a hydrogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a phenyl group, an aliphatic ring group or a halogen atom.
Y ²¹ represents an imino group or an oxygen atom.
L ⁴¹ represents an alkylene group having 1 to 16 carbon atoms, an arylene group having 6 to 12 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group, or a linking group obtained by combining these groups. However, ^{when the side of L 41} bonded to R ³⁴ is an alkylene group having 1 to 16 carbon atoms, R ³⁴ represents a hydrogen atom, a hydroxy group, a phenyl group, an aliphatic ring group or a halogen atom.
<6>
The binder composition for a non-aqueous secondary battery according to <5>, wherein the component represented by the above formula (O-31) contains a component having a glass transition temperature of 60 ° C. or lower.
<7>
The binder composition for a non-aqueous secondary battery according to any one of <1> to <6>, wherein the polymer has a weight average molecular weight of 100,000 or more.
<8>
The binder composition for a non-aqueous secondary battery according to any one of <1> to <7>, wherein the content of water in the binder composition is 10% by mass or more.
<9>
The binder composition for a non-aqueous secondary battery according to any one of <1> to <8>, and an electrode active material capable of inserting and releasing ions of a metal belonging to Group 1 or Group 2 of the periodic table. Compositions for electrodes containing and.
<10>
An electrode sheet having a layer composed of the electrode composition according to <9>.
<11>
A non-aqueous secondary battery having a positive electrode active material layer, a separator, and a negative electrode active material layer in this order, wherein at least one layer of the positive electrode active material layer and the negative electrode active material layer is described in <9>. A non-aqueous secondary battery, which is a layer composed of a composition for electrodes.
<12>
A method for producing an electrode sheet, which comprises a step of forming a film using the electrode composition according to <9>.
<13>
A method for manufacturing a non-aqueous secondary battery, which comprises incorporating an electrode sheet obtained by the manufacturing method according to <12> into an electrode of the non-aqueous secondary battery.

The binder composition for a non-aqueous secondary battery of the present invention can be mixed with solid particles such as an electrode active material and a conductive auxiliary agent to obtain a composition (slurry) having excellent dispersibility of these solid particles. can. The binder composition for a non-aqueous secondary battery, the composition for an electrode, and the electrode sheet of the present invention are collected between electrode active material particles or with electrode active material particles in a non-aqueous secondary battery in which an electrode is produced using these. The bondability with the electric body can be sufficiently enhanced, the resistance of the non-aqueous secondary battery can be reduced even when an electrode active material having a large volume change during charging and discharging is used, and the non-aqueous secondary battery can be reduced in resistance. The cycle life of the next battery can also be sufficiently extended.
In the non-aqueous secondary battery of the present invention, the binding property between the electrode active material particles or between the electrode active material particles and the current collector is sufficiently enhanced, and the volume change of the electrode active material during charging and discharging is large. Even when the one is adopted, it is possible to realize low resistance when the battery is driven, and it has a sufficiently long cycle life.
According to the method for producing an electrode sheet of the present invention, the electrode sheet of the present invention can be obtained. Further, according to the method for producing a non-aqueous secondary battery of the present invention, the above-mentioned non-aqueous secondary battery of the present invention can be obtained.

FIG. 1 is a vertical cross-sectional view schematically showing a basic laminated structure of a non-aqueous secondary battery.

In the description of the present invention, the numerical range represented by using "-" means a range including the numerical values before and after "-" as the lower limit value and the upper limit value.
In the present specification, the indication of a compound (for example, when referred to as a compound at the end) is used to mean that the compound itself, its salt, and its ion are included. In addition, it is meant to include a derivative in which a part of the structure is changed, such as by introducing a substituent, within a range in which a desired effect is obtained.
In the present specification, when the substituent has a dissociative hydrogen atom (a group in which a hydrogen atom is dissociated by the action of a base), the substituent includes an ion or salt form.
Substituents, linking groups, etc. (hereinafter referred to as substituents, etc.) for which substitution or non-substitution is not specified in the present specification mean that the group may have an appropriate substituent. Therefore, even when it is simply described as "-group" (for example, "alkyl group") in the present specification, this "-group" (for example, "alkyl group") does not have a substituent. In addition to the embodiment (eg, "unsubstituted alkyl group"), it also includes an aspect having a substituent (eg, "substituted alkyl group"). This is also synonymous with compounds that do not specify substitution or non-substitution. Preferred substituents include Substituent T, which will be described later.
When simply referred to as a "substituent" in the present specification, a substituent selected from the substituent T described later is preferably applied.
In the present specification, when there are a plurality of substituents, etc. indicated by specific reference numerals, or when a plurality of substituents, etc. are specified simultaneously or selectively, the respective substituents, etc. may be the same or different from each other. It means good. Further, even if it is not particularly specified, it means that when a plurality of substituents or the like are adjacent to each other, they may be connected to each other or condensed to form a ring.
In the present specification, when the polymer has a plurality of components having the same labeling (represented by the same general formula), the components may be the same or different from each other.
In the present invention, the "non-aqueous secondary battery" means a non-aqueous electrolyte secondary battery and an all-solid-state secondary battery. By "non-aqueous electrolyte" is meant an electrolyte that is substantially free of water. That is, the "non-aqueous electrolytic solution" may contain a small amount of water as long as the effect of the present invention is not impaired. In the present invention, the "non-aqueous electrolytic solution" has a water concentration of 1000 ppm (mass basis) or less, preferably 100 ppm or less, and more preferably 20 ppm or less. It is practically difficult to make the non-aqueous electrolytic solution completely anhydrous, and usually contains 1 ppm or more of water. The "all-solid secondary battery" means a secondary battery that does not use a liquid as an electrolyte but uses a solid electrolyte such as an inorganic solid electrolyte or a solid polymer electrolyte.

[Binder composition for non-aqueous secondary batteries]
The binder composition for a non-aqueous secondary battery of the present invention (also referred to as "the binder composition of the present invention") is a binder composition suitable as a material for forming a member or a constituent layer constituting a non-aqueous secondary battery. .. Typically, the binder composition of the present invention is mixed with an electrode active material (positive electrode active material or negative electrode active material, which is also simply referred to as “active material”) to be used as an electrode (non-aqueous secondary battery electrode). It can be used to form a positive electrode and / or negative electrode) active material layer. The binder composition of the present invention may be applied to the surface of a separator of a non-aqueous electrolyte secondary battery in order to form a heat-resistant layer, or may be used as a binder for coating a current collector. can.
The binder composition of the present invention contains a polymer having a constituent component containing a betaine structure as a binder component. In addition, the binder composition of the present invention contains a liquid medium that dissolves or disperses the polymer. The liquid medium is usually an aqueous medium containing water. In the present invention, the "aqueous medium containing water" is water or a mixed solution of water and a water-soluble organic solvent, and may also contain a neutralizing agent described later. The "water-soluble organic solvent" is an organic solvent that mixes with water without phase separation, and examples thereof include N-methylpyrrolidone, methanol, ethanol, acetone, and tetrahydrofuran.
The polymer, which is a binder component, is preferably dissolved in a liquid medium.

<Polymer>
The binder composition of the present invention contains a polymer having a component containing a betaine structure (a component derived from a monomer containing a betaine structure, hereinafter also referred to as “component (a)”). The "betaine structure" means that a positive charge and a negative charge are not adjacent to each other in the same molecule, and a dissociable hydrogen atom is not bonded to the atom having the positive charge, and the molecule as a whole is uncharged. Means the structure that is.
A polymer having a constituent component containing a betaine structure can act in an affinity for both positive and negative charges that solid particles such as an electrode active material and a conductive auxiliary agent can have, and the electrode activity. In the state where the material layer is formed, the binding property between the solid particles can be further enhanced. On the other hand, when the electrode composition (slurry) described later is prepared, the repulsion between positive charges or negative charges contributes to the improvement of the dispersibility of the solid particles, and the aggregation of the solid particles in the slurry is effective. Can be suppressed to.
Therefore, if the constituent component of the polymer has a betaine structure, the above-mentioned desired action can be exhibited.

Examples of the betaine structure contained in the component (a) include a carbobetaine structure, a sulfobetaine structure, and a phosphobetaine structure. Here, the carboxy group dissociated from the carbobetaine structure constitutes a negative charge of the betaine structure, the sulfo group dissociated from the sulfobetaine structure constitutes the negative charge of the betaine structure, and the phosphoric acid dissociated from the phosphobetaine structure. It is a betaine structure in which the group constitutes a negative charge of the betaine structure.
Further, the betaine structure contained in the component (a) usually has an ammonium cation structure, a sulfonium cation structure or a phosphonium cation structure as a positive charge, and more preferably has a quaternary ammonium cation structure.
The component (a) preferably has a betaine structure in the side chain from the viewpoint of further enhancing the bonding efficiency with the solid particles. In this case, the main chain of the polymer can be formed by the polymerization reaction of an ethylenically unsaturated group (carbon-carbon double bond).

The component (a) can be represented by any of the following formulas (J-1) to (J-4), for example.

In the formula, R ¹¹ to R ¹³ , R ¹⁶ to R ¹⁸ , R ²¹ to R ²³ , and R ²⁶ to R ²⁸ independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group, respectively. R ¹⁴ , R ¹⁵ , R ¹⁹ , R ²⁰ , R ²⁴ , R ²⁵ , R ²⁹ , R ³⁰ , and R ³¹ each independently represent a hydrogen atom or substituent. L ¹¹ to L ¹⁸ represent divalent linking groups.

Examples of halogen atoms that can be taken as R ¹¹ to R ¹³ , R ¹⁶ to R ¹⁸ , R ²¹ to R ²³ , and R ²⁶ to R ²⁸ include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. The ^{halogen atoms that can be taken as R 11} to R ¹³ , R ¹⁶ to R ¹⁸ , R ²¹ to R ²³ , and R ²⁶ to R ²⁸ are preferably fluorine atoms or chlorine atoms.

The ^{alkyl groups that can be taken as R 11} to R ¹³ , R ¹⁶ to R ¹⁸ , R ²¹ to R ²³ , and R ²⁶ to R ²⁸ may be linear or may have a branch. The ^{number of carbon atoms of the alkyl groups that can be taken as R 11} to R ¹³ , R ¹⁶ to R ¹⁸ , R ²¹ to R ²³ , and R ²⁶ to R ²⁸ is preferably 1 to 24, more preferably 1 to 12, and 1 to 8. More preferably, it is particularly preferably 1 to 4. A particularly preferable specific example of this alkyl group is methyl or ethyl, and methyl is particularly preferable.
R ¹¹ , R ¹² , R ¹⁶ , R ¹⁷ , R ²¹ , R ²² , R ²⁶ , and R ²⁷ are preferably hydrogen atoms. Further, R ¹³ , R ¹⁸ , R ²³ , and R ²⁸ are preferably hydrogen atoms or alkyl groups.

R ¹⁴ , R ¹⁵ , R ¹⁹ , R ²⁰ , R ²⁴ , R ²⁵ , R ²⁹ , R ³⁰ , and R ³¹ are preferably groups selected from the substituent T described later, and more preferably an alkyl group or an aryl group.
The preferred forms of the alkyl groups that can be taken as R ¹⁴ , R ¹⁵ , R ¹⁹ , R ²⁰ , R ²⁴ , R ²⁵ , R ²⁹ , R ³⁰ , and R ³¹ are the same as the preferred forms of the alkyl groups that can be taken as ^{R 11 above.} Is. Further, the ^{aryl group that can be taken as R 14} , R ¹⁵ , R ¹⁹ , R ²⁰ , R ²⁴ , R ²⁵ , R ²⁹ , R ³⁰ , and R ³¹ preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms. Preferably, 6 to 12 is more preferable, and 6 to 10 is particularly preferable. A particularly preferred embodiment of this aryl group is phenyl.

L ¹¹ to L ¹⁸ represent divalent linking groups. The ^{structures of L 11} to L ¹⁸ are not particularly limited as long as the betaine structure can be introduced into the polymer side chain. The chemical formulas of L ¹¹ to L ¹⁸ are preferably 14 to 2000, more preferably 14 to 200, and even more preferably 14 to 100.
The ^{divalent linking group that can be taken as L 11} to L ¹⁸ can have, for example, the following structure.
Alkylene group having 1 to 16 carbon atoms, an aromatic group, an oxygen atom, a sulfur atom, an imino group ^{(-N (R N) -)} , a carbonyl group, or two or more combined groups thereof.
"Imino group ^{(-N (R} N) -)" in the present invention ^{R N} of a hydrogen atom or a substituent. Substituents which can be taken as R ^N is not particularly limited, it includes groups selected from substituent group T described below, a hydrogen atom or an alkyl group is preferable.

The alkylene group having 1 to 16 carbon atoms which can be contained in L ¹¹ to L ^{18 may be a straight chain or may have a branch.} The ^{alkylene group that can be contained in L 11} to L ¹⁸ is more preferably 1 to 12 carbon atoms, further preferably 1 to 8 carbon atoms, and particularly preferably 1 to 6 carbon atoms.
The ^{aromatic group that can be contained in L 11} to L ¹⁸ may be an aromatic hydrocarbon group or a heteroaromatic group having a hetero atom in the ring-constituting atom. Moreover, this aromatic group may be a fused ring. Examples of ^{the aromatic ring constituting the aromatic group that can be contained in L 11} to L ¹⁸ include a benzene ring, a furan ring, a thiophene ring, a pyrazole ring, a pyrazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyridazine ring, and a pyrimidine ring. , Pyrazine ring, triazole ring, oxazole ring, thiazole ring and the like, and a fused ring in which two or more (preferably two or three) of these rings are condensed may be used. Of these, a phenylene group is preferable as the aromatic group that can be contained in ^{L 21.}

^{^{^{L 11, L 13, L 15}}} , and ^{L 17} is an ester bond (-C (= O) O-) or an amide bond ^{(-C (= O) NR N} -, R N is the above ^{R N} in the imino group It is preferable to have (synonymous). These ester bonds and amide bonds are preferably derived from the (meth) acryloyloxy group and the (meth) acrylamide group of the monomer, respectively. In the present invention, "(meth) acryloyl" means to include both methacryloyl and acryloyl (the same applies to "(meth) acrylic" and "(meth) acrylamide").
It ^{is also preferable that L 11} , L ¹³ , L ¹⁵ and L ¹⁷ have the above aromatic groups. Further, L ¹¹ , L ¹³ , L ¹⁵ and L ¹⁷ preferably have an alkylene group, and preferably have an oxygen atom (—O—, an oxygen atom that does not form an ester bond).
L ¹¹ , L ¹³ , L ¹⁵ and L ¹⁷ are a combination of an ester bond and an alkylene group, a combination of an amide bond and an alkylene group, a combination of an ester bond and an alkylene group and an oxygen atom, or an amide bond and an alkylene. A combination of a group and an oxygen atom is preferred. In these cases, the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, further preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms.
^{^{^{L 11, L 13, L 15}}} , and the amide ^{bond L 17} may have ^{(-C (= O) NR N} -) in, ^{R N} may have a betaine structure. For example, ^RN is an alkyl group, and a betaine structure can be contained in the substituent of this alkyl group.
Further, the formula (J-1), in the (J-2) and ^{(J-3), L 11} , L 13, and the above amide ^{bond L 15} may have each ^{R N} having amide bond, It can also be in the form combined with R ¹⁴ , R ¹⁹ and R ^{24, respectively.}

L ¹² , L ¹⁴ , L ¹⁶ and L ¹⁸ preferably have an alkylene group, may be a combination of an alkylene group and an oxygen atom, and more preferably an alkylene group or an oxyalkylene group. The alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, further preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms.

Although preferable specific examples of the component (a) are shown below, the above components are not limited to these in the present invention.

The polymer constituting the binder component is also referred to as a component having at least one salt structure of a carboxylate, a sulfonate, a phosphate, a phosphonate, a nitrate and an ammonium salt (hereinafter, also referred to as a component (b)). It is preferable to have.). This component (b) is a component different from the component (a).
The salt structure may be contained in the main chain or the side chain, but is preferably contained in the side chain. By including the constituent component having the salt structure, the content thereof can be adjusted and the water solubility of the polymer can be increased to a desired level. In addition, the interaction with the surface of the active material or the current collector is also enhanced, and it is considered that it can contribute to the improvement of the binding property.

The component (b) is preferably derived from a compound having a (meth) acryloyl group or a (meth) acryloyl group.
The chemical formula amount of the component (b) is preferably 60 to 60,000, more preferably 70 to 20,000. Further, a form in which a crosslinked structure is formed by neutralizing a divalent or higher valent metal or a polyfunctional organic base is also preferable. In the present invention, "(meth) acryloyl" is a concept that includes both methacryloyl and acryloyl.
The component (b) is preferably a component having at least one salt structure of a carboxylate, a sulfonate and a phosphate.

As the counterion for forming the salt structure, an ordinary cation or anion can be used. Examples of cations as counterions include metal cations, and examples thereof include sodium ion, lithium ion, potassium ion, calcium ion, magnesium ion, zinc ion and the like. It is also preferable to have an amine-derived cation. Such amines include polyvalent amines such as polyethyleneimine, monoalkylamines such as hexylamine, dialkylamines such as dibutylamine, trialkylamines such as triethylamine, alcohol amines such as ethanolamine, and aromatic rings such as benzylamine and dimethylaminopyridine. Polycyclic amines such as contained amines and diazabicycloundecene can be preferably used.
Examples of anions as counterions include halogen anions.
Two or more counterions may be used to form the salt structure. For example, it is also preferable to use a metal cation and an amine-derived cation (preferably a polyvalent amine-derived cation such as polyethyleneimine) in combination.

The polymer may have a constituent component (bH) in which the constituent component (b) does not have a salt structure and a hydrogen atom is bonded to the terminal. That is, the polymer having the constituent component (bH) forms a salt structure in part or all of the constituent component (bH) in the presence of the neutralizing agent, and exists as the constituent component (b). The ratio (100 × Z / Q) of the molar amount (Z) of the constituent component (b) to the total molar amount (Q) of the constituent component (bH) and the constituent component (b) is the degree of neutralization of the polymer. (Mole%). The degree of neutralization of the polymer is preferably 30 mol% or more, more preferably 50 mol% or more, further preferably 60 mol% or more, and particularly preferably 70 mol% or more. The degree of neutralization of the polymer may be 100 mol%, preferably 95 mol% or less, and more preferably 90 mol% or less.
Examples of the neutralizing agent include hydroxides, carbonates and hydrogen carbonates of metals belonging to Group 1 of the periodic table, hydroxides of metals belonging to Group 2 of the periodic table, inorganic bases such as carbonates, and polyethylene. Polyvalent amines such as imine, diazabicycloundecene, pyridine, triethylamine, benzylamine, pentylamine, octylamine, dibutylamine, ethanolamine, organic bases such as histidine, inorganic bases such as hydrochloric acid, hydrogen bromide, sulfuric acid, nitrate, etc. Examples thereof include organic acids such as acids, formic acids, acetic acids, oxalic acids and citric acids. The neutralizing agent may be used alone or in combination of two or more, and it is preferable to use two or more in combination. Preferred neutralizers include lithium hydroxide, sodium hydroxide, polyethyleneimine and diazabicycloundecene as sources of counterion cations, and hydrochloric acid as sources of counterion anions. ..

Specific examples of the constituent component (b) are shown below, but the constituent component (b) is not construed as being limited to these in the present invention.

As the constituent component (b), a salt of (meth) acrylic acid can be preferably used.

The polymer constituting the binder component preferably has a component represented by the following formula (O-31) (hereinafter, also referred to as a component (c)). The component (c) represented by the formula (O-31) is a component different from the component (a), the component (b), and the component (bH).

In the formula (O-31), R ³¹ to R ³³ independently represent a hydrogen atom, a cyano group, a halogen atom or an alkyl group, respectively. The alkyl groups that can be taken as ^{R 31} to R ³³ are synonymous with the alkyl groups that can be taken as ^{R 11} to R ^{13 of the formula (J-1), and the preferred forms are also the same.}

R ³⁴ represents a hydrogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a phenyl group, an aliphatic ring group or a halogen atom.
The alkyl group having 1 to 12 carbon atoms which can be taken as R ^{34 may be linear or branched.} The alkyl group preferably has 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms.
The ^{aliphatic ring group that can be taken as R 34} is preferably a 5-membered ring or a 6-membered ring. Further, it is preferably an aliphatic heterocyclic group. The ring-constituting heteroatom contained in the aliphatic heterocyclic group is preferably an oxygen atom, a sulfur atom or a nitrogen atom, and more preferably an oxygen atom.
R ³⁴ is more preferably a hydroxy group.

Y ²¹ represents an imino group or an oxygen atom.

L ⁴¹ represents an alkylene group having 1 to 16 carbon atoms, an arylene group having 6 to 12 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group, or a linking group combining these. However, ^{when the side of L 41} bonded to R ³⁴ is an alkylene group having 1 to 16 carbon atoms, R ³⁴ is a hydrogen atom, a hydroxy group, a phenyl group, an aliphatic ring group or a halogen atom (preferably a fluorine atom or chlorine). Atom) is shown. The alkylene group having 1 to 16 carbon atoms preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, further preferably 1 to 8 carbon atoms, and particularly preferably 1 to 6 carbon atoms.
The chemical formula of L ⁴¹ is preferably 14 to 2000, more preferably 28 to 500, and even more preferably 40 to 200.
The alkylene group having 1 to 16 carbon atoms that L ^{41 can have may be linear or branched.} The alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, further preferably 1 to 8 carbon atoms, and particularly preferably 1 to 6 carbon atoms.

Examples of L ⁴¹ include an alkylene group having 1 to 16 carbon atoms, an alkyleneoxy group (the alkyleneoxy group preferably has 1 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, further preferably 2 to 4 carbon atoms), and a polyalkyleneoxy group. (The number of repetitions of the alkyleneoxy group (average number of repetitions) is preferably 2 to 10, more preferably 2 to 5, still more preferably 2 or 3; the number of carbon atoms of the alkyleneoxy group is preferably 1 to 10, and 2 to 6 is preferable. More preferably, 2 to 4 is more preferable) or an arylene group having 6 to 12 carbon atoms is preferable. Among them, an alkylene group having 1 to 16 carbon atoms is more preferable, an alkylene group having 1 to 12 carbon atoms is further preferable, an alkylene group having 1 to 10 carbon atoms is particularly preferable, and an alkylene group having 1 to 8 carbon atoms is particularly preferable. Most preferably, it is an alkylene group having 1 to 6 carbon atoms.

The component (c) has a glass transition temperature (Tg) of preferably 60 ° C. or lower, more preferably 40 ° C. or lower, further preferably 20 ° C. or lower, and preferably 0 ° C. or lower. Especially preferable.
The Tg of the component (c) is a Tg of a polymer composed of the component (c) alone, and the Tg described in the table of the POLYMER HANDBOOK forth edition VI chapter is adopted. The Tg of polymers not listed in the above table is determined by actual measurement. That is, a dry sample of the polymer is prepared and measured under the following conditions using a differential scanning calorimeter: X-DSC7000 (trade name, manufactured by SII Nanotechnology Inc.). The measurement is performed twice on the same sample, and the result of the second measurement is adopted.
Atmosphere in the measurement room: Nitrogen gas (50 mL / min)
Temperature rise rate: 5 ° C / min Measurement start temperature: -80 ° C
Measurement end temperature: 250 ° 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 descending start point and the descending end point of the DSC chart.
The Tg of the component (c) is preferably −45 ° C. or higher.

Specific examples of the constituent component (c) are shown below, but the constituent component (c) is not construed as being limited to these in the present invention.

It is also preferable that the polymer has, as the constituent component (c), two or more kinds of hydroxyalkyl acrylate components having different chain lengths of alkylene groups.

Examples of the substituent T include the following.
Alkyl groups (preferably alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), Alkyl groups (preferably alkyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, oleyl, etc.), alkynyl groups (preferably alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, butadiynyl, phenylethynyl). Etc.), cycloalkyl groups (preferably cycloalkyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), aryl groups (preferably having 6 to 26 carbon atoms). Aryl groups such as phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl, etc., heterocyclic groups (preferably heterocyclic groups having 2 to 20 carbon atoms, more preferably It is a 5- or 6-membered heterocyclic group having at least one oxygen atom, sulfur atom, and nitrogen atom. The heterocyclic group includes an aromatic heterocyclic group and an aliphatic heterocyclic group, for example, a tetrahydropyran ring group. , Tetrahydrofuran ring group, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzoimidazolyl, 2-thiazolyl, 2-oxazolyl, etc.), alkoxy group (preferably alkoxy group having 1 to 20 carbon atoms, for example, methoxy , Ethoxy, isopropyloxy, benzyloxy, etc.), aryloxy groups (preferably aryloxy groups having 6 to 26 carbon atoms, such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), Heterocyclic oxy group (group in which —O— group is bonded to the above heterocyclic group), alkoxycarbonyl group (preferably alkoxycarbonyl group having 2 to 20 carbon atoms, for example, ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc.) , Aryloxycarbonyl groups (preferably aryloxycarbonyl groups having 6 to 26 carbon atoms, such as phenoxycarbonyl, 1-naphthyloxycarbonyl, 3-methylphenoxycarbonyl, 4-methoxyphenoxycarbonyl, etc.), amino groups (preferably phenoxycarbonyl, 4-methoxyphenoxycarbonyl, etc.). Contains an amino group, an alkylamino group, and an arylamino group having 0 to 20 carbon atoms, for example, amino (-NH ₂ ), 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 (alkylcarbonyl groups, alkenylcarbonyls, etc.) Acrylic groups containing a group, an alkynylcarbonyl group, an arylcarbonyl group, a heterocyclic carbonyl group, preferably having 1 to 20 carbon atoms, such as acetyl, propionyl, butyryl, octanoyl, hexadecanoyl, acryloyl, methacryloyl, crotonoyl, Bencoyl, naphthoyl, nicotineol, etc.), acyloxy groups (alkylcarbonyloxy groups, alkenylcarbonyloxy groups, alkynylcarbonyloxy groups, arylcarbonyloxy groups, heterocyclic carbonyloxy groups, etc., preferably acyloxy having 1 to 20 carbon atoms. Groups such as acetyloxy, propionyloxy, butyryloxy, octanoyloxy, hexadecanoyloxy, acryloyloxy, methacryloxy, crotonoyloxy, benzoyloxy, naphthoyloxy, nicotinoyyloxy, etc., allyloyloxy groups (preferably). Is an allylloyloxy group having 7 to 23 carbon atoms, for example, benzoyloxy, a carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, for example, N, N-dimethylcarbamoyl, N-phenylcarbamoyl). Etc.), acylamino groups (preferably acylamino groups having 1 to 20 carbon atoms, such as acetylamino, benzoylamino, etc.), alkylthio groups (preferably alkylthio groups having 1 to 20 carbon atoms, such as methylthio, ethylthio). , Isopropylthio, benzylthio, etc.), arylthio groups (preferably arylthio groups having 6 to 26 carbon atoms, such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc.), heterocyclic thio groups. (A group in which an —S— group is bonded to the heterocyclic group), an alkylsulfonyl group (preferably an alkylsulfonyl group having 1 to 20 carbon atoms, for example, methylsulfonyl, ethylsulfonyl, etc.), an arylsulfonyl group (preferably). An arylsulfonyl group having 6 to 22 carbon atoms, for example, a benzenesulfonyl group, an alkylsilyl group (preferably an alkylsilyl group having 1 to 20 carbon atoms, for example, monomethylsilyl, dimethylsilyl, trimethylsilyl, triethylsilyl, etc.) ), An arylsilyl group (preferably an arylsilyl group having 6 to 42 carbon atoms, for example, triphenylsilyl), a phosphoryl group (preferably a phosphoric acid group having 0 to 20 carbon atoms, for example, -OP ( ^{_{= O) (R P) 2}} ), a phosphonyl group (preferably a phosphonyl group having a carbon number of 0 to 20, for ^{example, -P (= O) (R} P) 2), a phosphinyl group (preferably a carbon number of 0 ~ 20 a is a phosphinyl group, for example, ^-P (R _P) 2), a sulfo group (sulfonic acid group), a carboxy group, hydroxy group, sulfanyl group, a cyano group, a halogen atom (e.g. fluorine atom, a chlorine atom, a bromine atom , Iodine atom, etc.). ^RP is a hydrogen atom or a substituent (preferably a group selected from the substituent T).
Further, each group listed in these substituents T may further have the above-mentioned substituent T as a substituent.

Among the polymers as binder components, the content of the component (a) represented by the formula (J-1) is preferably 2 to 60% by mass, more preferably 3 to 25% by mass, and 4 to 20% by mass. % Is more preferable, and 5 to 15% by mass is particularly preferable.
When the polymer has a component (b) and / or a component (bH) in addition to the component (a) represented by the formula (J-1), the component (b) in the polymer ) And / or the total content of the constituent component (bH) is preferably 2 to 95% by mass, more preferably 3 to 70% by mass, further preferably 5 to 60% by mass, and 5 to 30% by mass. Especially preferable. The total content of the constituent component (b) and / or the constituent component (bH) may be 6 to 95% by mass, 7 to 95% by mass, or 7 to 90% by mass. The ratio of the molar amount of the constituent component (b) to the total molar amount of the constituent component (b) and the constituent component (bH) is as described in the above-mentioned degree of neutralization of the polymer.
When the polymer has a component (c) represented by the formula (O-31), the content of the component (c) represented by the formula (O-31) in the polymer is 2 to 90. It is preferably mass%, more preferably 5 to 90% by mass, further preferably 10 to 90% by mass, particularly preferably 20 to 90% by mass, and even more preferably 40 to 85% by mass. , 60 to 85% by mass is most preferable.

The polymer, which is a binder component constituting the binder composition of the present invention, has characteristics that can follow repeated expansion and contraction of the active material when it is assumed to be used in a non-aqueous electrolyte secondary battery, and a desired result. From the viewpoint of developing adhesion and prolonging the cycle life, it is preferable to exhibit a certain degree of swelling property with respect to the electrolytic solution. For example, the swelling rate of the polymer is 1% or more and less than 200% with respect to a solvent (pseudo-electrolyte solution) in which ethylene carbonate and ethyl methyl carbonate are mixed in a mass ratio of ethylene carbonate / ethyl methyl carbonate = 1/2. Is more preferable, 7% or more and less than 150% is more preferable, 8% or more and less than 150% is further preferable, and 10% or more and less than 150% is particularly preferable. Here, when the polymer does not swell in the above solvent, the swelling rate is 0%. The swelling rate is determined by the method described in Examples described later.

The weight average molecular weight of the polymer is preferably 100,000 or more. When the weight average molecular weight of the polymer is sufficiently large, the binding action of the polymer becomes large, and the cycle life of the non-aqueous secondary battery in which the binder composition containing the polymer is used is extended.

The weight average molecular weight is a weight average molecular weight converted to sodium polyacrylate by gel permeation chromatography (GPC), and can be determined under the following conditions.
Measuring instrument: HLC-8220GPC (trade name, manufactured by Tosoh Corporation)
Column: Connect TOSOH TSKgel 5000PWXL (trade name, manufactured by Tosoh), TOSOH TSKgel G4000PWXL (trade name, manufactured by Tosoh), and TOSOH TSKgel G2500PWXL (trade name, manufactured by Tosoh).
Carrier: 200 mM sodium nitrate aqueous solution Measurement temperature: 40 ° C
Carrier flow rate: 1.0 ml / min
Sample concentration: 0.2%
Detector: RI (refractive index) detector

When the weight average molecular weight cannot be measured under the above measurement conditions such as when the polymer is crosslinked, the weight average molecular weight is measured by static light scattering under the following conditions.
Measuring instrument: DLS-8000 (trade name, manufactured by Otsuka Electronics Co., Ltd.)
Measured concentration: 0.25, 0.50, 0.75, 1.00 mg / ml
Diluted solution: 0.1 M NaCl aqueous solution Laser wavelength: 633 nm
Pinhole: PH1 = Open, PH2 = Slit
Measurement angle: 60, 70, 80, 90, 100, 110, 120, 130 degrees Analytical method: The molecular weight was measured from the Zim square root plot. The dn / dc required for the analysis is actually measured with an Abbe refractive index meter.

The binder composition of the present invention may contain the above-mentioned polymer alone or in combination of two or more.

The polymer can be synthesized by combining monomers leading to each of the above constituent components according to the purpose and, if necessary, addition polymerization in the presence of a catalyst (including a polymerization initiator, a chain transfer agent, etc.). The method and conditions for addition polymerization are not particularly limited, and ordinary methods and conditions can be appropriately selected.

The binder composition of the present invention contains water in an amount of preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass, and particularly preferably 40% by mass or more. The binder composition of the present invention may contain 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more of water.
The content of the polymer in the binder composition of the present invention may be appropriately set according to the intended purpose. For example, the content of the polymer in the binder composition can be 2 to 50% by mass, preferably 4 to 30% by mass, and more preferably 6 to 20% by mass. In the binder composition of the present invention, the balance excluding the polymer is preferably composed of water, a neutralizing agent, and a water-soluble organic solvent, and the balance excluding the polymer is water and a neutralizing agent. Is more preferable.

[Composition for electrodes]
In addition to the above binder composition, the electrode composition of the present invention contains an active material capable of inserting and releasing ions of a metal belonging to Group 1 or Group 2 of the periodic table. If necessary, a conductive auxiliary agent and other additives can be further included. The active material may be a positive electrode active material or a negative electrode active material. When the electrode composition contains a positive electrode active material, the electrode composition can be used as a slurry for forming a positive electrode active material layer in a non-aqueous secondary battery. When the electrode composition contains a negative electrode active material, the electrode composition can be used as a slurry for forming a negative electrode active material layer. The binder composition can be applied to both positive and negative electrode compositions, but is preferably used for the negative electrode, and particularly preferably for the negative electrode composition having a silicon atom-containing active material.
The active material, the conductive auxiliary agent, and the other additive are not particularly limited, and may be appropriately selected from those used in conventionally known non-aqueous secondary batteries according to the purpose.

(Positive electrode active material)
The positive electrode active material is preferably one capable of reversibly inserting and releasing lithium ions. The material is not particularly limited as long as it has the above-mentioned properties, and may be an element that can be composited with Li such as a transition metal oxide, an organic substance, or sulfur, or a composite of sulfur and a metal.
Among them, as the positive electrode active material, a transition metal oxide having preferably used a transition metal oxide, a transition metal element ^{M a (Co, Ni, Fe} , Mn, 1 or more elements selected from Cu and V) the The thing is more preferable. Further, the 1 (Ia) group elements of the transition metal oxide to elemental ^{M b} (Table Periodic other than lithium, the elements of the 2 (IIa) group, Al, Ga, In, Ge , Sn, Pb, Sb , Bi, Si, P or B) may be mixed. The mixing amount is preferably 0 ~ 30 mol% relative to the amount of the transition metal element ^{M a (100mol%).} It is more preferable that the mixture is synthesized by mixing so that the molar ratio of Li / Ma is 0.3 to 2.2.
Specific examples of the transition metal oxide include (MA) a transition metal oxide having a layered rock salt type structure, (MB) a transition metal oxide having a spinel type structure, (MC) a lithium-containing transition metal phosphate compound, and (MD). ) Lithium-containing transition metal halide phosphoric acid compound, (ME) lithium-containing transition metal silicic acid compound and the like can be mentioned.

(MA) Specific examples of the transition metal oxide having a layered rock salt structure include LiCoO ₂ (lithium cobalt oxide [LCO]), LiNi ₂ O ₂ (lithium nickel oxide), LiNi _0.85 Co _0.10 Al _{0. 05} O ₂ (Lithium Nickel Cobalt Aluminate [NCA]), LiNi _1/3 Co _1/3 Mn _1/3 O ₂ (Lithium Nickel Manganese Cobalt Oxide [NMC]) and LiNi _0.5 Mn _0.5 O ₂ ( Lithium manganese nickel oxide).
(MB) Specific examples of the transition metal oxide having a 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 can be mentioned.
Examples of the (MC) lithium-containing transition metal phosphate compound 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 _{, and LiCoPO 4.} Examples thereof include cobalt phosphates of Li ₃ V ₂ (PO ₄ ) ₃ (lithium vanadium phosphate) and other monoclinic pachicon-type vanadium phosphate salts.
(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 Fluorophosphate cobalts such as.
Examples of the (ME) lithium-containing transition metal silicic acid 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 type structure is preferable, and LCO or NMC is more preferable.

The shape of the positive electrode active material is not particularly limited, but it is preferably in the form of particles. The average particle size (sphere-equivalent average particle size) of the positive electrode active material is not particularly limited. For example, it can be 0.1 to 50 μm. In order to make the positive electrode active material have a predetermined particle size, a normal crusher 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 positive electrode active material may be used alone or in combination of two or more.
When forming the positive electrode active material layer, the mass (mg) (grain amount) 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 appropriately determined according to the designed battery capacity.

The content of the positive electrode active material in the composition for the electrode layer is not particularly limited, and is preferably 10 to 99% by mass, more preferably 30 to 98% by mass, and 50 to 97% by mass in terms of solid content of 100% by mass. More preferably, 55 to 95% by mass is particularly preferable.

(Negative electrode active material)
The negative electrode active material is preferably one that can reversibly occlude and release lithium ions. The material is not particularly limited as long as it has the above characteristics, and is a carbonaceous material, a silicon-based material, a metal oxide, a metal composite oxide, a simple substance of lithium, a lithium alloy, and a negative electrode active material capable of forming an alloy with lithium. And so on. Of these, carbonaceous materials or silicon-based materials are preferably used from the viewpoint of reliability.

The carbonaceous material used as the negative electrode active material is a material substantially composed of carbon. For example, carbon black obtained by firing various synthetic resins such as carbon black such as petroleum pitch, graphite (artificial graphite such as natural graphite and vapor-grown graphite), and PAN (polyacrylonitrile) -based resin or furfuryl alcohol resin. Materials can be mentioned. Further, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-phase-grown carbon fiber, dehydrated PVA (polypoly alcohol) -based carbon fiber, lignin carbon fiber, glassy carbon fiber and activated carbon fiber. Kind, mesophase microspheres, graphite whisker, flat plate graphite and the like can also be mentioned.

The metal oxide and the metal composite oxide applied as the negative electrode active material are not particularly limited as long as they are oxides capable of storing and releasing lithium, and amorphous oxides are preferable, and metal elements and the periodic table Calcogenite, which is a reaction product with Group 16 elements, is also preferably mentioned. Amorphous here means an X-ray diffraction method using CuKα rays, which has a broad scattering band having an apex in a region of 20 ° to 40 ° in 2θ value, and is a crystalline diffraction line. May have.
Among the compound group consisting of the amorphous oxide and the chalcogenide, the amorphous oxide of the metalloid element and the chalcogenide are more preferable, and the elements of the Group 13 (IIIB) to 15 (VB) of the Periodic Table. Oxides consisting of one of Al, Ga, Si, Sn, Ge, Pb, Sb and Bi alone or a combination of two or more thereof, or chalcogenides are particularly preferable. Specific examples of preferable amorphous oxides and chalcogenides include, for example, Ga ₂ O ₃ , GeO, 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 , Sb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ O ₄ , GeS, PbS, PbS ₂ , Sb ₂ S ₃ and Sb ₂ S ₅ is preferably mentioned.

It is preferable that the metal (composite) oxide and the chalcogenide contain at least one of titanium and lithium as constituent components from the viewpoint of high current density charge / discharge characteristics. Examples of the lithium-containing metal composite oxide (lithium composite metal oxide) include a composite oxide of lithium oxide and the metal (composite) oxide or the chalcogenide, and more specifically, Li ₂ SnO _2. Can be mentioned.

It is also preferable that the negative electrode active material contains a titanium atom. More specifically, TiNb ₂ O ₇ (nioboxide titanate [NTO]) and Li ₄ Ti ₅ O ₁₂ (lithium titanate [LTO]) are rapidly charged because the volume fluctuation during the occlusion and release of lithium ions is small. It is preferable in that it has excellent discharge characteristics, suppresses deterioration of electrodes, and can improve the life of a lithium ion secondary battery.

The lithium alloy as the negative electrode active material is not particularly limited as long as it is an alloy usually used as the negative electrode active material of the secondary battery, and examples thereof include a lithium aluminum alloy.

The negative electrode active material that can be alloyed with lithium is not particularly limited as long as it is usually used as the negative electrode active material of the secondary battery. Such an active material has a large expansion and contraction due to charge and discharge, and the binding property of solid particles is lowered as described above. However, in the present invention, a high binding property can be achieved by the binder. Examples of such an active material include a negative electrode active material having a silicon atom or a tin atom, and each metal such as Al and In, and a negative negative active material having a silicon atom (silicon atom-containing active material) capable of higher battery capacity. ) Is preferable, and a silicon atom-containing active material having a silicon atom content of 40 mol% or more of all the constituent atoms is more preferable.
Generally, a negative electrode containing these negative electrode active materials (for example, a Si negative electrode containing a silicon atom-containing active material, a Sn negative electrode containing an active material having a tin atom) is a carbon negative electrode (graphite, acetylene black, etc.). Compared to, more Li ions can be occluded. That is, the amount of Li ions occluded per unit mass increases. Therefore, the battery capacity (energy density) can be increased. As a result, there is an advantage that the battery drive time can be lengthened.
Examples of the silicon atom-containing active material include silicon materials such as Si and SiOx (0 <x ≦ 1), and alloys containing titanium, vanadium, chromium, manganese, nickel, copper, or lanthanum (for example, LaSi ₂ , VSi ₂ ) or an organized active material (for example, LaSi ₂ / Si), and other active materials containing silicon atoms and tin atoms such as _{SnSiO 3} and SnSiS _{3 can be mentioned.} In addition, SiOx itself can be used as a negative electrode active material (metalloid oxide), and since Si is generated by the operation of the battery, it can be used as an active material (precursor material thereof) that can be alloyed with lithium. Can be used.
Examples of the negative electrode active material having a tin atom include Sn, SnO, SnO ₂ , SnS, SnS ₂ , and the active material containing the silicon atom and the tin atom. Also included are composite oxides with lithium oxide, such as Li ₂ SnO _2.

The shape of the negative electrode active material is not particularly limited, but it is preferably in the form of particles. The average particle size of the negative electrode active material is preferably 0.1 to 60 μm. A normal crusher or classifier is used to obtain a predetermined particle size. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling airflow type jet mill, a sieve, or the like is preferably used. At the time of pulverization, wet pulverization in which water or an organic solvent such as methanol coexists can also be performed. It is preferable to perform classification in order to obtain a desired particle size. The classification method is not particularly limited, and a sieve, a wind power classifier, or the like can be used as desired. Both dry and wet classifications can be used.

The negative electrode active material may be used alone or in combination of two or more. Among them, a combination of a silicon atom-containing active material and a carbonaceous material is preferable, and a combination of SiOx (0 <x≤1) and graphite is particularly preferable. The mass ratio (SiOx / graphite) when combining SiOx (0 <x≤1) and graphite is preferably 2 or less, more preferably 1 or less, and even more preferably 0.5 or less.
When the negative electrode active material layer is formed, the mass (mg) (grain amount) 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 appropriately determined according to the designed battery capacity.

The content of the negative electrode active material in the composition for the electrode layer is not particularly limited, and is preferably 10 to 98% by mass, more preferably 20 to 90% by mass, based on 100% by mass of the solid content.

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

In the present invention, when the negative electrode active material layer is formed by charging the battery, instead of the negative electrode active material, metal ions belonging to Group 1 or Group 2 of the periodic table generated in the all-solid secondary battery are used. Can be used. A negative electrode active material layer can be formed by combining these ions with electrons and precipitating them as a metal.

(Coating of active material)
The surfaces of the positive electrode active material and the negative electrode active material may be surface-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 thereof include spinel titanate, tantalum oxide, niobate oxide, lithium niobate compound and the like. Specifically, Li ₄ Ti ₅ O ₁₂ , Li ₂ Ti ₂ O ₅ and 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.
Further, the surface of the electrode containing the positive electrode active material or the negative electrode active material may be surface-treated with sulfur or phosphorus.
Further, the surface of the positive electrode active material or the particle surface of the negative electrode active material may be surface-treated with active light rays or an active gas (plasma or the like) before and after the surface coating.

(Conductive aid)
The electrode composition of the present invention may also contain a conductive auxiliary agent, and it is particularly preferable that the silicon atom-containing active material as the negative electrode active material is used in combination with the conductive auxiliary agent.
The conductive auxiliary agent is not particularly limited, and those known as general conductive auxiliary agents can be used. For example, electron conductive materials such as 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 fibers or carbon nanotubes. It may be a carbon fiber such as graphene or fullerene, a metal powder such as copper or nickel, or a metal fiber, and a conductive polymer such as polyaniline, polypyrrole, polythiophene, polyacetylene, or polyphenylene derivative. You may use it.
In the present invention, when the active material and the conductive auxiliary agent are used in combination, among the above conductive auxiliary agents, the conductive auxiliary agent that does not insert and release Li when the battery is charged and discharged and does not function as the active material. And. Therefore, among the conductive auxiliary agents, those that can function as active materials in the active material layer when the battery is charged and discharged are classified as active materials instead of conductive auxiliary agents. Whether or not the battery functions as an active material when it is charged and discharged is not unique and is determined by the combination with the active material.

As the conductive auxiliary agent, one kind may be used, or two or more kinds may be used.
The content of the conductive auxiliary agent in the composition for the electrode layer is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on 100% by mass of the solid content.

The shape of the conductive auxiliary agent is not particularly limited, but it is preferably in the form of particles. The median diameter D50 of the conductive auxiliary agent is not particularly limited, and is preferably 0.01 to 50 μm, more preferably 0.02 to 10.0 μm, for example.

(Other additives)
The solid electrolyte composition of the present invention contains, if desired, a lithium salt, an ionic liquid, a thickener, an antifoaming agent, a leveling agent, a dehydrating agent, an antioxidant and the like as components other than the above-mentioned components. Can be done. Further, a cross-linking agent for chemically cross-linking the above polymer (such as one that undergoes a cross-linking reaction by radical polymerization, condensation polymerization or ring-opening polymerization), and a polymerization initiator (such as one that generates an acid or radical by heat or light). May be contained.
Regarding the above-mentioned active material, conductive auxiliary agent, and other additives used in a non-aqueous secondary battery, for example, International Publication No. 2019/203334, Japanese Patent Application Laid-Open No. 2015-46389 and the like can be referred to.

The content of the active material in the electrode composition of the present invention can be adjusted to, for example, 50 to 99% by mass. Further, in the electrode composition of the present invention, the mass ratio of the content of the active material to the polymer (binder component) can be set to active material / polymer = 1/1 to 200/1, and the active material / polymer. It is more preferable to set = 1/33 to 5/1.

[Electrode sheet]
The electrode sheet of the present invention has a layer (active material layer, that is, a negative electrode active material layer or a positive electrode active material layer) constructed by using the electrode composition of the present invention. The electrode sheet of the present invention may be an electrode sheet having an active material layer, and even a sheet in which the active material layer is formed on a base material (current collector) does not have a base material (negative electrode or positive electrode). ) It may be a sheet formed only by the active material layer. This electrode sheet is usually a sheet having a structure in which an active material layer is laminated on a current collector. The electrode sheet of the present invention may have other layers such as a protective layer (release sheet) and a coat layer.
The electrode sheet of the present invention can be suitably used as a material constituting the negative electrode active material layer or the positive electrode active material layer of a non-aqueous secondary battery.

[Manufacturing method of electrode sheet]
The electrode sheet of the present invention can be obtained by forming an active material layer using the electrode composition of the present invention. For example, a current collector or the like is used as a base material, and the electrode composition of the present invention is applied onto the base material (may be via another layer) to form a coating film, which is dried to form a base material. An electrode sheet having an active material layer (coating dry layer) on top can be obtained.

[Non-water secondary battery]
In the present invention, the non-aqueous secondary battery means a general device in which ions pass between positive and negative electrodes via a non-aqueous medium by charging and discharging, and energy is stored and released in the positive and negative electrodes. That is, it means that both a battery and a capacitor (lithium ion capacitor) are included. From the viewpoint of energy storage, the non-aqueous secondary battery of the present invention is preferably used for battery applications (not a capacitor).
The non-aqueous secondary battery of the present invention has a configuration including a positive electrode, a negative electrode, and a separator arranged between the positive electrode and the negative electrode. In an all-solid-state secondary battery using an inorganic solid electrolyte, the separator can be an inorganic solid electrolyte layer.
The positive electrode has a positive electrode current collector and a positive electrode active material layer in contact with the positive electrode current collector, and the negative electrode has a negative electrode current collector and a negative electrode active material layer in contact with the negative electrode current collector. In the non-aqueous secondary battery of the present invention, at least one layer of the positive electrode active material layer and the negative electrode active material layer is formed by using the electrode composition of the present invention.

FIG. 1 is a cross-sectional view schematically showing a laminated structure of a general non-aqueous secondary battery 10 including an operating electrode when operating as a battery. The non-aqueous secondary battery 10 has a laminated structure having a negative electrode current collector 1, a negative electrode active material layer 2, a separator 3, a positive electrode active material layer 4, and a positive electrode current collector 5 in this order when viewed from the negative electrode side. There is.
When the non-aqueous secondary battery 10 is a non-aqueous electrolyte secondary battery, the space between the negative electrode active material layer and the positive electrode active material layer is filled with a non-aqueous electrolytic solution (not shown) and separated by a separator 3. ing. In this case, the separator 3 has holes and functions as a positive / negative electrode separation membrane that insulates between the positive and negative electrodes while allowing the electrolytic solution and ions to pass through in a normal battery use state.
When the non-aqueous secondary battery 10 is an all-solid-state secondary battery, the negative electrode active material layer and the positive electrode active material layer are separated by a solid electrolyte layer 3.
With such a structure, for example, in the case of a lithium ion secondary battery, during charging, electrons (e ⁻ ) are supplied to the negative electrode side through an external circuit, and at the same time, lithium ions (Li ⁺ ) are released from the positive electrode via the electrolytic solution. It moves and accumulates in the negative electrode. On the other hand, at the time of discharge, lithium ions (Li ⁺ ) accumulated in the negative electrode are returned to the positive electrode side via the electrolytic solution or the solid electrolyte layer, and electrons are supplied to the operating portion 6. In the illustrated example, a light bulb is used for the operating portion 6, and the light bulb is turned on by electric discharge.
In the present invention, the negative electrode current collector 1 and the negative electrode active material layer 2 are collectively referred to as a negative electrode, and the positive electrode active material layer 4 and the positive electrode current collector 5 are collectively referred to as a positive electrode.

Each material, non-aqueous electrolyte solution, solid electrolyte, member, etc. used in the non-aqueous secondary battery of the present invention is particularly limited except that a specific layer is formed by using the binder composition or the electrode composition of the present invention. Not done. As these materials, members and the like, those used for ordinary non-aqueous secondary batteries can be appropriately applied. Further, as for the method for producing the non-aqueous secondary battery of the present invention, a usual method through the production of an electrode sheet is used except that a specific layer is formed by using the binder composition or the composition for electrodes of the present invention. It can be adopted as appropriate. For example, Japanese Patent Application Laid-Open No. 2016-201308, Japanese Patent Application Laid-Open No. 2005-108835, Japanese Patent Application Laid-Open No. 2012-185938, and the like can be appropriately referred to.
The preferred form of the non-aqueous electrolyte solution will be described in more detail.

(Electrolytes)
The electrolyte used in the non-aqueous electrolyte solution is preferably a salt of a metal ion belonging to Group 1 or Group 2 of the periodic table. The salt of the metal ion to be used is appropriately selected depending on the purpose of use of the non-aqueous electrolytic solution. For example, lithium salt, potassium salt, sodium salt, calcium salt, magnesium salt and the like can be mentioned, and when used in a non-aqueous electrolyte secondary battery or the like, the lithium salt is preferable from the viewpoint of output. When the non-aqueous electrolytic solution of the present invention is used as the non-aqueous electrolytic solution for a lithium ion secondary battery, a lithium salt may be selected as the salt of the metal ion. As the lithium salt, a lithium salt usually used as an electrolyte in a non-aqueous electrolyte solution for a lithium ion secondary battery is preferable, and for example, those described below are preferable.

(L-1) inorganic lithium _{_{_{salt: LiPF 6, LiBF 4, LiAsF}}} 6, LiSbF 6 inorganic fluoride salts, such _as, LiClO _4, Libro 4, perhalogenate of LiIO ₄ such as an inorganic chloride salts such as LiAlCl ₄ etc

(L-2) Fluorine-containing organic lithium salt: Perfluoroalkane sulfonate such as _{LiCF 3} SO ₃ _{, LiN (CF 3} SO ₂ ) ₂ , LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F9SO ₂ ) and other perfluoroalkanesulfonylimide salts, LiC (CF ₃ SO ₂ ) _{3 and} other perfluoroalcansulfonylmethide salts, 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 )], Perfluoroalkyl fluorinated phosphates such as Li [PF ₄ (CF ₂ CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF ₂ CF ₃ ) _{3], etc.}

(L-3) Oxalatoborate salt: Lithium bis (oxalate) borate, lithium difluorooxalate borate, etc.

Among these, LiPF ₆ , LiBF ₄ , _{LiAsF 6} , LiSbF ₆ , LiClO ₄ , Li (Rf1SO ₃ ), LiN (Rf1SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf1SO ₂ ) (Rf2SO ₂ ) Is preferable, and lithium imide salts such as _{LiPF 6} , LiBF ₄ , LiN (Rf1SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ and LiN (Rf1SO ₂ ) (Rf2SO _{2) are more preferable.} Here, Rf1 and Rf2 each represent a perfluoroalkyl group.
As the electrolyte used in the non-aqueous electrolyte solution, one type may be used alone, or two or more types may be arbitrarily combined.

The salt concentration of the electrolyte (preferably the ion of a metal belonging to Group 1 or Group 2 of the Periodic Table or a metal salt thereof) in the non-aqueous electrolyte solution is appropriately selected depending on the purpose of use of the non-aqueous electrolyte solution, but is generally selected. Is 10% by mass to 50% by mass, more preferably 15% by mass to 30% by mass, based on the total mass of the non-aqueous electrolyte solution. The molar concentration is preferably 0.5 M to 1.5 M. When evaluating the ion concentration, it may be calculated in terms of salt with a metal that is preferably applied.

(Non-aqueous solvent)
The non-aqueous electrolytic solution of the present invention contains a non-aqueous solvent.
As the non-aqueous solvent used in the present invention, an aprotic organic solvent is preferable, and an aprotic organic solvent having 2 to 10 carbon atoms is particularly preferable.
Such non-aqueous solvents include chain or cyclic carbonate compounds, lactone compounds, chain or cyclic ether compounds, ester compounds, nitrile compounds, amide compounds, oxazolidinone compounds, nitro compounds, chain or cyclic sulfone or Examples include sulfoxide compounds and phosphate esters.
A compound having an ether bond, a carbonyl bond, an ester bond or a carbonate bond is preferable. These compounds may have a substituent, and examples thereof include the above-mentioned substituent T.

Examples of the non-aqueous solvent include ethylene carbonate, fluorinated ethylene carbonate, vinylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methylpropyl carbonate, γ-butyrolactone, γ-valerolactone, 1, 2-Dimethoxyethane, tetrahydrofuran, 2-methyl tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, 1,4-dioxane, methyl acetate, ethyl acetate, propion Methyl acid, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethylacetate, ethyl trimethylacetate, acetonitrile, glutaronitrile, adiponitrile, methoxynitrile, 3-methoxypropionitrile, N, N-dimethylformamide, N-methyl Examples thereof include pyrrolidinone, N-methyloxazolidinone, N, N'-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, dimethylsulfoxide, dimethylsulfoxideric acid and the like. These may be used alone or in combination of two or more. Among them, at least one of the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, and γ-butyrolactone is preferable, and in particular, high viscosity (high dielectric constant) such as ethylene carbonate or propylene carbonate is preferable. A combination of a solvent (for example, relative permittivity ε ≧ 30) and a low viscosity solvent such as dimethyl carbonate, ethyl methyl carbonate or diethyl carbonate (for example, viscosity ≦ 1 mPa · s) is more preferable. By using such a combination of mixed solvents, the dissociability of the electrolyte salt and the mobility of ions are improved.
The non-aqueous solvent used in the present invention is not limited to these.

The non-aqueous secondary battery of the present invention is, for example, a laptop computer, a pen input computer, a mobile computer, an electronic book player, a mobile phone, a cordless phone handset, a pager, a handy terminal, a mobile fax, a mobile copy, a mobile printer, a headphone stereo. , Video movies, LCD TVs, handy cleaners, portable CDs, mini discs, electric shavers, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, memory cards, and other electronic devices. .. For consumer use, it can be installed in automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.). It can also be combined with a solar cell.

Hereinafter, the present invention will be described in more detail based on Examples. It should be noted that the present invention is not construed as being limited thereto. In the following examples, "parts" and "%" representing the composition are based on mass unless otherwise specified.

<Preparation of binder composition containing polymer B-1>
260.0 g of distilled water was added to a 1 L three-necked flask equipped with a reflux condenser and a gas introduction cock. After introducing nitrogen gas for 60 minutes at a flow rate of 200 mL / min, the temperature was raised to 75 ° C. Liquid prepared in a separate container (acrylic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 6.0 g, hydroxyethyl acrylate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 48.0 g, 3-[[2- (methacryloyloxy) ethyl) ] Dimethylammonio] Propionate (manufactured by Tokyo Kasei Co., Ltd., a monomer giving a repeating unit represented by the above formula a-3) 6.0 g, distilled water 80.0 g, VA-057 (trade name: Fujifilm Wako Pure Chemical Industries, Ltd.) (Manufactured) 0.46 g was stirred and mixed, and the mixture was added dropwise over 1 hour. After the dropping was completed, stirring was continued at 75 ° C. for 3 hours. Then, it was cooled in an ice bath, and 5.6 g of a 48% aqueous sodium hydroxide solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added. Then, 240.0 g of distilled water was added to obtain an aqueous solution of binder B-1. The solid content concentration was 10.0% and the weight average molecular weight was 243000. The degree of neutralization of the polymer is 80 mol%.
The amount of monomers used (% by mass) in the table below is the ratio of each monomer when the amount of all monomers used is 100% by mass. Further, in the column of the constituent component (a), the code (“a-1” or the like) of the constituent component itself is described, and the mass% thereof indicates the amount of the monomer used to guide the constituent component. Is.

<Preparation of binder composition containing polymers B-2 to B-14>
A monomer (represented by the above formula a-1 or a-3) leading to the component (a) shown in Table 1, a neutralizing agent, and another monomer (acrylic acid, methacrylic acid, 2-acrylamide-2-methyl). Polymer B using propanesulfonic acid, N- (2-hydroxyethyl) acrylamide, 2-hydroxyethyl acrylate, tetrahydrofurfuryl acrylate, methoxypolyethylene glycol acrylate (molecular weight about 2000), 4-hydroxybutyl acrylate). Each aqueous solution (binder composition) containing polymers B-2 to B-14 as a binder component was obtained in the same manner as in -1. The solid content concentration of each of the aqueous solutions was 10.0%. The degree of neutralization of the polymers is 80 mol%.

The structures of the polymers B-1 to B-14 are shown below.

(Measurement of weight average molecular weight)
The weight average molecular weights (Mw) of the polymers B-1 to B-8, B-10, and B-12 to B-14 are the weight average molecular weights converted to sodium polyacrylate by gel permeation chromatography (GPC). , It is a value measured under the following conditions.
Measuring instrument: HLC-8220GPC (trade name, manufactured by Tosoh Corporation)
Columns: TOSOH TSKgel 5000PWXL (trade name, manufactured by Tosoh), TOSOH TSKgel G4000PWXL (trade name, manufactured by Tosoh), and TOSOH TSKgel G2500PWXL (trade name, manufactured by Tosoh) were connected.
Carrier: 200 mM sodium nitrate aqueous solution Measurement temperature: 40 ° C
Carrier flow rate: 1.0 ml / min Sample concentration: 0.2%
Detector: RI (refractive index) detector

The weight average molecular weights (Mw) of the polymers B-9 and B-11 were measured by static light scattering under the following conditions.
Measuring instrument: DLS-8000 (trade name, manufactured by Otsuka Electronics Co., Ltd.)
Measured concentration: 0.25, 0.50, 0.75, 1.00 mg / ml
Diluted solution: 0.1 M NaCl aqueous solution Laser wavelength: 633 nm
Pinhole: PH1 = Open, PH2 = Slit
Measurement angle: 60, 70, 80, 90, 100, 110, 120, 130 degrees Analytical method: The molecular weight was measured from the Zim square root plot. The dn / dc required for the analysis was measured with an Abbe refractive index meter.

(Determination of glass transition temperature)
The Tg of the polymer constituent was determined by the method described above.

[Test Example 1] Evaluation of swelling rate with respect to simulated electrolytic solution 5 g of each binder composition prepared above was placed on a surface hydrophobized PET (NP75C, trade name, manufactured by Panac) sheet and dried at 50 ° C. for 6 hours. After that, each binder film was peeled off from the hydrophobized PET. Each of the obtained binder membranes was dried at 150 ° C. in vacuum for 6 hours. Weigh 0.10 g of each binder film after drying in a glass bottle, add 1.90 g of a solvent (simulated electrolyte) mixed with ethylene carbonate / ethyl methyl carbonate = 1/2 by mass ratio, and add 24 at 60 ° C. Heated for hours. After heating, each binder film was taken out and the mass (Ws) was measured. After drying each binder film in a vacuum of 150 ° C. for 5 hours, the mass (Wd) was measured again. The obtained Ws and Wd values were applied to the following formula to calculate the swelling rate. The results are shown in Table 1.
Swelling degree (%) = [(Ws-Wd) / Wd] x 100

[Test Example 2] Evaluation of dispersibility of solid particles 0.30 g of acetylene black (trade name: Denka Black, manufactured by Denka, conductive aid) in a 60 mL ointment container (manufactured by Mano Chemical Co., Ltd.), 2.50 g of each binder aqueous solution (Solid content: 0.25 g) was added, and the mixture was dispersed at 2000 rpm for 10 minutes using Awatori Rentaro (manufactured by THINKY). 2.5 g of distilled water was added to the dispersed liquid, and the mixture was dispersed at 2000 rpm for 3 minutes using Awatori Rentaro (manufactured by THINKY). 2.5 g of distilled water was added to the dispersed liquid, and the mixture was dispersed at 2000 rpm for 3 minutes using Awatori Rentaro (manufactured by THINKY). 3.2 g of the obtained liquid was added to a 60 mL ointment container (manufactured by Mano Kagaku Co., Ltd.), 7.2 g of distilled water was further added, and the mixture was dispersed at 2000 rpm for 3 minutes. 0.1 g of the obtained liquid and 14.5 g of water were added to a 30 mL sample bottle and diluted. The diluted solution was measured with ELSZ-1000S (trade name: manufactured by Otsuka Electronics Co., Ltd.) for the average particle size of scattering intensity. The above measurement was repeated 5 times, and the average value was evaluated based on the following evaluation rank. The results are shown in Table 2.
-Dispersibility evaluation rank-
6: Less than 1.9 μm 5: 1.9 μm or more and less than 2.2 μm 4: 2.2 μm or more and less than 2.7 μm 3: 2.7 μm or more and less than 3.3 μm 2: 3.3 μm or more and less than 4.0 μm 1: 4.0 μm or more

[Preparation of electrode sheet]
Silicon monoxide (particle size: 5 μm, manufactured by Osaka Titanium) 1.35 g, graphite (trade name: MAG-D, manufactured by Hitachi Kasei) 3.15 g, acetylene black (manufactured by Mano Chemical Co., Ltd.) in a 60 mL ointment container (manufactured by Mano Chemical Co., Ltd.) Product name: Denka Black, manufactured by Denka) 0.25 g, each binder composition 2.50 g (solid content 0.25 g), and distilled water 1.6 g are added, and 2000 rpm using Awatori Rentaro (manufactured by THINKY). Was dispersed for 10 minutes. 1.3 g of distilled water was added to the dispersed liquid, and the mixture was dispersed at 2000 rpm for 10 minutes using Awatori Rentaro (manufactured by THINKY).
The obtained composition for each electrode (negative electrode) (containing 27% silicon monoxide, 63% graphite, 5% acetylene black, and 5% binder) was applied on a copper foil having a thickness of 20 μm by an applicator, and 1 at 80 ° C. Allowed to dry for hours. Then, after pressurizing using a press machine, it was dried in a vacuum of 150 ° C. for 6 hours to obtain each electrode (negative electrode) sheet having a thickness of the negative electrode active material layer of 25 μm.

[Test Example 3] Evaluation of Bondability The average stress when an adhesive tape is attached to the entire electrode sheet cut out to a width of 10 mm and a length of 50 mm and peeled off at an angle of 90 ° at 100 mm / min in the length direction is obtained. It was measured. The above measurement was repeated 8 times, and the average value was evaluated based on the following evaluation rank. The results are shown in Table 2.
-Evaluation rank of cohesion-
6: 0.6N or more 5: 0.4N or more and less than 0.6N 4: 0.2N or more and less than 0.4N 3: 0.1N or more and less than 0.2N 2: 0.05N or more and less than 0.1N 1: Less than 0.05N

[Manufacturing of non-water secondary battery (2032 type coin battery)]
Each of the above electrode sheets was cut out into a disk shape having a diameter of 13.0 mm and used as a negative electrode. Lithium foil (thickness 50 μm, 14.5 mmφ) and polypropylene separator (thickness 25 μm, 16.0 mmφ) are stacked in this order, and 1M LiPF ₆ ethylene carbonate / ethylmethyl carbonate (volume ratio 1: 2) electrolytic solution is used as a 200 μL separator. Soaked in. Further, 200 μL of an electrolytic solution was added on the separator, and the negative electrode was laminated so that the active material layer surface was in contact with the separator. Then, the 2032 type coin case was crimped to prepare each coin battery (a laminate composed of Li foil-separator-negative electrode active material layer-copper foil).

[Test Example 4] Evaluation of Resistance The discharge capacity retention rate of each coin battery was measured by a charge / discharge evaluation device: TOSCAT-3000 (trade name, manufactured by Toyo System Co., Ltd.). Charging was performed at a C rate of 0.2 C (the speed at which the battery is fully charged in 5 hours) until the battery voltage reaches 0.02 V. The discharge was performed at a C rate of 0.2 C until the battery voltage reached 1.5 V. Each coin battery was initialized by repeating charging and discharging for three cycles with one charge and one discharge as one charge and discharge cycle. Since it is a half cell of the negative electrode, the voltage drops during charging and rises during discharging.
After initialization, the battery voltage was carried out at a C rate of 0.2 C until the battery voltage reached 0.02 V, and the discharge was carried out at 2 C until the battery voltage reached 1.5 V. The discharge capacity at this time was compared with the discharge capacity (discharge capacity retention rate) when the discharge capacity in the third cycle at the time of initialization was 100%, and the resistance was evaluated by applying to the following evaluation ranks. The smaller the discharge capacity retention rate, the higher the resistance. The results are shown in Table 2.
-Evaluation rank of discharge capacity retention rate (resistance)-
6: 96% or more 5: 94% or more and less than 96% 4: 92% or more and less than 94% 3: 87% or more and less than 92% 2: 80% or more and less than 87% 1: less than 80%

[Test Example 5] Evaluation of cycle characteristics The discharge capacity retention rate of each coin battery was measured by a charge / discharge evaluation device: TOSCAT-3000 (trade name, manufactured by Toyo System Co., Ltd.). Charging was performed at a C rate of 0.2 C (the speed at which the battery is fully charged in 5 hours) until the battery voltage reaches 0.02 V. The discharge was performed at a C rate of 0.2 C until the battery voltage reached 1.5 V. Each coin battery was initialized by repeating charging and discharging for three cycles with one charge and one discharge as one charge and discharge cycle.
After initialization, charging was performed at 0.5 C until 0.02 V was reached. Discharge was performed at 0.5 C until 1.5 V was reached. The cycle characteristics were evaluated by repeating charging and discharging for 50 cycles, with one charge and one discharge as one charge and discharge cycle. When the discharge capacity (initial discharge capacity) of the first cycle after initialization is 100%, the discharge capacity (discharge capacity retention rate) of the 50th cycle (discharge capacity with respect to the initial discharge capacity) is measured and applied to the following evaluation ranks. The characteristics were evaluated. The results are shown in Table 2.
-Evaluation rank of discharge capacity retention rate (cycle characteristics)-
6: 92% or more 5: 87% or more, less than 92% 4: 80% or more, less than 87% 3: 70% or more, less than 80% 2: 50% or more, less than 70% 1: less than 50%

[Comparative Examples 1 and 2]
As a binder component, in Comparative Example 1, the polymer BC-1 (methacrylic acid / ethyl acrylate / 1,6-hexanediol acrylate copolymer) described in Example 1 of JP-A-2015-18776 was used in Comparative Example 2. Then, the polymer BC-2 (acrylamide / N-methylol acrylamide / acrylamide t-butyl sulfonic acid / sodium methacrylic sulfonate / acrylic acid / ethyl acrylate / acrylonitrile copolymer described in Production Example 3 of JP-A-2018-6334) ) Was used to prepare a binder composition (solid content concentration: 10%) to prepare each coin cell BC-1 and BC-2, in the same manner as above, in terms of binding property, resistance, and cycle characteristics. Was evaluated. The results are shown in Table 2.

Each electrode sheet using polymers BC-1 and BC-2 as a binder for the negative electrode active material layer, which have an acidic group but do not have a constituent component containing the betaine structure specified in the present invention in the polymer side chain. Although the binding property can be improved to some extent, the dispersibility of the solid particles is low, the resistance of the obtained battery is high, and the cycle characteristics are also inferior. In other words, it was not possible to bring all of the dispersibility, binding properties, battery resistance, and cycle characteristics of solid particles to sufficient characteristics.
On the other hand, each of the electrode sheets using the polymers B-1 to B-14 having the constituent components containing the betaine structure specified in the present invention as the binder of the negative electrode active material layer has the dispersibility and binding property of solid particles. It was found that it was excellent, the resistance of the obtained battery was sufficiently low, and the cycle life was sufficiently extended.

Although the present invention has been described with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified, and contrary to the spirit and scope of the invention set forth in the appended claims. I think that it should be widely interpreted without.

The present application claims priority based on Japanese Patent Application No. 2020-073022, which was filed in Japan on April 15, 2020, which is referred to herein and is described herein. Incorporate as a part.

10 Non-aqueous electrolyte secondary battery 1 Negative electrode current collector 2 Negative electrode active material layer 3 Separator 4 Positive electrode active material layer 5 Positive electrode current collector 6 Operating part (light bulb)

Claims

A binder composition for a non-aqueous secondary battery, which comprises a binder composed of a polymer having a constituent component containing a betaine structure.
The non-aqueous secondary battery according to claim 1, wherein the polymer has a component having at least one salt structure of a carboxylate, a sulfonate, a phosphate, a phosphonate, a nitrate and an ammonium salt. Binder composition.
The non-statement of claim 2, wherein the salt structure is at least one of a carboxylate, a sulfonate, a phosphate, a phosphonate, and a nitrate, and the salt structure has a counterion derived from a polyvalent amine. Binder composition for water secondary batteries.
Any of claims 1 to 3, wherein the swelling rate of the polymer is 1% or more and less than 200% with respect to a solvent in which ethylene carbonate and ethyl methyl carbonate are mixed in a mass ratio of ethylene carbonate / ethyl methyl carbonate = 1/2. The binder composition for a non-aqueous secondary battery according to item 1.
The binder composition for a non-aqueous secondary battery according to any one of claims 1 to 4, wherein the polymer has a component represented by the following formula (O-31).

In the formula, R 31 to R 33 independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group having 1 to 24 carbon atoms.
R 34 represents a hydrogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a phenyl group, an aliphatic ring group or a halogen atom.
Y 21 represents an imino group or an oxygen atom.
L 41 represents an alkylene group having 1 to 16 carbon atoms, an arylene group having 6 to 12 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group, or a linking group obtained by combining these groups. However, when the side of L 41 bonded to R 34 is an alkylene group having 1 to 16 carbon atoms, R 34 represents a hydrogen atom, a hydroxy group, a phenyl group, an aliphatic ring group or a halogen atom.
The binder composition for a non-aqueous secondary battery according to claim 5, wherein the component represented by the formula (O-31) contains a component having a glass transition temperature of 60 ° C. or lower.
The binder composition for a non-aqueous secondary battery according to any one of claims 1 to 6, wherein the polymer has a weight average molecular weight of 100,000 or more.
The binder composition for a non-aqueous secondary battery according to any one of claims 1 to 7, wherein the content of water in the binder composition is 10% by mass or more.
The binder composition for a non-aqueous secondary battery according to any one of claims 1 to 8 and an electrode active material capable of inserting and releasing ions of a metal belonging to Group 1 or Group 2 of the periodic table. Composition for electrodes including.
An electrode sheet having a layer composed of the electrode composition according to claim 9.
The ninth aspect of the non-aqueous secondary battery, which has a positive electrode active material layer, a separator, and a negative electrode active material layer in this order, wherein at least one layer of the positive electrode active material layer and the negative electrode active material layer is described in claim 9. A non-aqueous secondary battery, which is a layer composed of a composition for electrodes.
A method for producing an electrode sheet, which comprises a step of forming a film using the electrode composition according to claim 9.
A method for manufacturing a non-aqueous secondary battery, which comprises incorporating the electrode sheet obtained by the manufacturing method according to claim 12 into an electrode of the non-aqueous secondary battery.