JP2015115226A - Electrode composition for batteries, battery electrode, and battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an electrode composition for batteries which allows an electrode to remarkably exert its function because of the electrode allowed to have a metal alone and/or a metal oxide sufficiently distributed therein, and makes possible to bring about the effect of enhancement of a battery performance largely, and to stabilize the battery quality; and a battery electrode and a battery, each of which is arranged by use of such an electrode composition according to a simple manufacturing process.SOLUTION: An electrode composition for batteries comprises: an active material; a metal alone and/or a metal oxide; and a polymer. The polymer has a carboxyl group and/or a carboxylate group, and a polyalkylene glycol chain.

Description

The present invention relates to a battery electrode composition, a battery electrode, and a battery. More specifically, the present invention relates to a battery electrode composition capable of forming a battery electrode having high battery performance and stabilized quality, a battery electrode obtained by a simple manufacturing process using the same, and a battery.

In recent years, the use of batteries has spread to portable devices and automobiles. The importance of battery development / improvement is increasing in many industrial fields, and accordingly, each of the members constituting the battery has been actively studied. Among them, the battery electrode is an important member having a great influence on the characteristics of the battery, and a composition for forming the battery electrode has been actively studied.

Various additives are used in the battery electrode composition. Additives are often filled into battery electrodes together with active materials, and in primary batteries, functions such as self-discharge suppression during battery storage and stabilization of output current during battery use are required. In addition to these functions, a function that suppresses battery deterioration associated with charge / discharge cycles is required, and those that exhibit these functions satisfactorily are selected. For example, in a lithium ion battery, in addition to the active material, a conductive additive such as carbon for ensuring the electron conductivity of the electrode is disclosed as an additive (see, for example, Patent Document 1). Moreover, in the alkaline secondary battery, various additives for improving battery performance are proposed in addition to the conductive assistant (see, for example, Patent Documents 2 to 4).

JP 2004-14519 A JP-A-1-289068 Japanese Unexamined Patent Publication No. 1-223963 Japanese Patent Laid-Open No. 1-200556

From the standpoint of maximizing the function of the additive, it is considered desirable that it is uniformly dispersed in the electrode. However, the smaller the particle size of the additive, the more the interparticle interaction increases. However, the particles tend to aggregate. Therefore, it can be said that ensuring the dispersibility is an important factor in the production of battery electrodes, particularly when the desired additive has a small particle size.

Moreover, when a metal simple substance and / or a metal oxide are selected as an additive, the surfaces thereof tend to aggregate due to a small amount of water. For example, when the function of making the current flowing through the electrode uniform by a single metal and / or metal oxide is exhibited, the dispersion state is important as described above. Therefore, if the metal simple substance and / or metal oxide aggregates, the above functions cannot be sufficiently obtained, and the amount of the metal simple substance and / or metal oxide introduced into the electrode composition is not sufficient. There existed a subject that the said function was not fully exhibited.

The present invention has been made in view of the above-described situation, and a simple metal and / or a metal oxide can be sufficiently dispersed in an electrode to exhibit its function more remarkably, and greatly improve the battery performance. An object of the present invention is to provide a battery electrode composition capable of stabilizing the quality of a battery, a battery electrode obtained by a simple manufacturing process using the same, and a battery.

The present inventors pay attention to the possibility that if the metal alone and / or the metal oxide can be sufficiently dispersed in the electrode, the function can be exhibited more remarkably in the composition. Various methods for dispersing a single metal and / or a metal oxide were studied. Further, by including a polymer having a specific functional group in the electrode composition, it is possible to disperse the metal alone and / or the metal oxide more sufficiently in the electrode as compared with the conventional electrode composition. It is possible to simplify the manufacturing process for dispersing the single substance and / or the metal oxide, and to sufficiently exhibit the functions such as the improvement of the high rate discharge characteristics, and to solve the above problems brilliantly. The headline, the present invention has been reached. A battery produced using such an electrode composition can be suitably used in many industrial fields from portable devices to automobiles.

That is, the present invention is a battery electrode composition containing an active material, wherein the battery electrode composition further contains a metal element and / or a metal oxide and a polymer, and the polymer is a carboxyl group. And / or a battery electrode composition having a carboxylate group and a polyalkylene glycol chain.

This invention is also a battery electrode comprised using the battery electrode composition of this invention.
The present invention is also a battery configured using the battery electrode of the present invention and an electrolyte.
The present invention is described in detail below.
In addition, the form which combined two or more each preferable structure of this invention described below is also a preferable form of this invention.

The electrode composition for a battery according to the present invention includes an active material, and further includes a single metal and / or a metal oxide and a polymer. The polymer includes a carboxyl group and / or a carboxylate group, and a polyalkylene glycol. Has a chain. Such a polymer exhibits high dispersion performance because its carboxyl group is adsorbed on a single metal and / or metal oxide, and its polyalkylene glycol chain disperses the single metal and / or metal oxide due to its steric hindrance. It is considered possible.

The ratio of the polymer in the battery electrode composition of the present invention is 0.01% by mass or more based on 100% by mass of the metal simple substance and / or metal oxide in the battery electrode composition of the present invention. preferable. More preferably, it is 0.1 mass% or more, More preferably, it is 1 mass% or more, Most preferably, it is 2 mass% or more. Moreover, it is preferable that the said ratio is 50 mass% or less. More preferably, it is 20 mass% or less, More preferably, it is 10 mass% or less, Most preferably, it is 8 mass% or less.

The polymer in the battery electrode composition of the present invention may have a polyoxyalkylene chain and a carboxyl group in the molecule, but the structural unit (A) derived from the unsaturated polyalkylene glycol monomer (a). And a structural unit (B) derived from an unsaturated carboxylic acid monomer (b). Hereinafter, such a polymer is also referred to as “polycarboxylic acid copolymer in the present invention”.

The unsaturated polyalkylene glycol monomer (a) is represented by the following general formula (1) from the viewpoint of particularly enhancing the dispersion performance:

(In the formula, R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R ² represents a hydrogen atom or a methyl group. AO represents an oxyalkylene group having 2 to 18 carbon atoms. P is 0, 1 or 2. q is 0 or 1. r represents the average number of added moles of the oxyalkylene group represented by AO and is a number from 2 to 300. Represented,
The unsaturated carboxylic acid monomer (b) is represented by the following general formula (2):

（式中、Ｒ^３及びＲ^４は、同一若しくは異なって、水素原子、メチル基又は−ＣＯＯＭ^２基を表す。Ｒ^５は、水素原子又はメチル基を表す。Ｍ^１及びＭ^２は、同一若しくは異なって、水素原子、金属原子、アンモニウム基又はアミン基を表す。なお、Ｒ^３及びＲ^４は、同時に−ＣＯＯＭ^２基を表さない。また、Ｒ^４が−ＣＯＯＭ^２基を表す場合、当該Ｒ^４と−ＣＯＯＭ^１基とが酸無水物基を形成していてもよい。）で表されることが好ましい。

(In the formula, R ³ and R ⁴ are the same or different and each represents a hydrogen atom, a methyl group, or a —COOM ² group. R ⁵ represents a hydrogen atom or a methyl group. M ¹ and M ² are the same or Differently, it represents a hydrogen atom, a metal atom, an ammonium group or an amine group, wherein R ³ and R ⁴ do not simultaneously represent a —COOM ² group, and when R ⁴ represents a —COOM ² group, R ⁴ and the —COOM ¹ group may form an acid anhydride group.

The number r in the general formula (1) is particularly preferably 5 to 200.
In addition, the polycarboxylic acid-type copolymer in this invention may further contain the structural unit (C) derived from the other monomer (c) mentioned later. Moreover, each structural unit in the polycarboxylic acid-type copolymer in this invention may be 1 type, respectively, and 2 or more types may be sufficient as it.
Hereinafter, the unsaturated polyalkylene glycol monomer (a) is also referred to as “monomer (a)”, and the unsaturated carboxylic acid monomer (b) is also referred to as “monomer (b)”.

In the polycarboxylic acid copolymer in the present invention, the proportion of the structural units (A) and (B) is preferably 1% by mass or more with respect to 100% by mass of all the structural units. If the structural unit (A) is less than 1% by mass or the structural unit (B) is less than 1% by mass, the dispersibility of the single metal and / or metal oxide may not be sufficiently improved. The content ratio of the structural unit (A) in the total amount of the structural units (A) and (B) of 100% by mass is preferably 60 to 96% by mass, more preferably 70 to 95% by mass, and still more preferably 80%. It is -94 mass%, Most preferably, it is 84-94 mass%. Moreover, as a content rate of the structural unit (B) which occupies in the total amount 100 mass% of structural unit (A) and (B), Preferably it is 3-50 mass%, More preferably, it is 3-35 mass%, More preferably, Is 4 to 30% by mass, still more preferably 4 to 25% by mass, and particularly preferably 4 to 14% by mass.
By setting the above range, the dispersibility of the single metal and / or metal oxide can be remarkably improved, and functions such as equalization of the current flowing through the electrode due to the single metal and / or metal oxide can be increased. It is possible to further develop the function and effect of the present invention.

Further, the total ratio (mass%) of the structural units (A) and (B) is preferably 70 to 100 mass% with respect to 100 mass% of all the structural units. That is, it is preferable that the content rate of the structural unit (C) derived from another monomer (c) is 0-30 mass% with respect to 100 mass% of all the structural units. The total ratio of the structural units (A) and (B) in 100% by mass of all the structural units is more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass. .

Here, in this specification, when calculating the ratio of the structural unit (B) derived from the unsaturated carboxylic acid monomer (b), the structural unit (B) is a completely neutralized single monomer. It is calculated as a structural unit derived from a body (salt). For example, when acrylic acid is used as the monomer (b) and neutralized with sodium hydroxide in the polymerization reaction, sodium acrylate is used as the monomer (b). ).

In the polycarboxylic acid copolymer of the present invention, the proportion of the structural unit (A) is preferably 50 mol% or less with respect to 100 mol% of all structural units. This is because the unsaturated polyalkylene glycol monomer (a) constituting the structural unit (A) is not sufficiently polymerizable, and the above polycarboxylic acid copolymer having high dispersion performance is obtained in a high yield. This is because the proportion of the monomer (a) used is preferably 50 mol% or less with respect to 100 mol% of all monomer components. More preferably, it is 49 mol% or less.

Next, the monomer component constituting the polycarboxylic acid copolymer in the present invention will be further described. In addition, each monomer can use 1 type (s) or 2 or more types, respectively.
<Unsaturated polyalkylene glycol monomer (a)>
The monomer (a) is a monomer represented by the above general formula (1), and the structural unit (A) derived from the monomer (a) is a monomer (a). Means a structure in which the unsaturated double bond (carbon-carbon double bond) portion of the is a single bond.

In the general formula (1), AO represents an oxyalkylene group having 2 to 18 carbon atoms. Among them, an oxyalkylene group having 2 to 8 carbon atoms is preferable, and examples thereof include an oxyethylene group, an oxypropylene group, an oxybutylene group, an oxyisobutylene group, an oxymethylethylene group, an oxyoctylene group, and an oxystyrene group. An oxyalkylene group having 2 to 4 carbon atoms is more preferable, and an oxyethylene group is particularly preferable. In addition, the polyalkylene glycol chain represented by (AO) _r may be formed by two or more oxyalkylene groups. In this case, two or more oxyalkylene groups are randomly added or blocked. Any addition form such as addition and alternate addition may be used.

In the general formula (1), the ratio of oxyethylene groups in 100 mol% of all oxyalkylene groups is preferably 50 mol% or more. Thereby, sufficient dispersion performance can be exhibited. More preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably 90 mol% or more, most preferably 100 mol%, that is, a polyalkylene glycol chain represented by (AO) _r only by oxyethylene groups. Is formed. In addition, as the combination having two or more oxyalkylene groups, (oxyethylene group, oxypropylene group), (oxyethylene group, oxybutylene group), (oxyethylene group, oxystyrene group) are preferable. . Among these, (oxyethylene group, oxypropylene group) is more preferable.

The average addition mole number (average chain length of the polyalkylene glycol chain) r of the oxyalkylene group is a number of 2 to 300. From the viewpoint of improving the dispersion performance by the polycarboxylic acid copolymer in the present invention, the lower limit of r is preferably not less than a specific value in the following order (a larger numerical value is preferable). That is, 5 or more, 10 or more, 15 or more, 20 or more, or 22 or more are preferable. On the other hand, when r exceeds 300, the copolymerizability may not be sufficient, and the dispersibility retention performance may not be sufficiently exhibited. Therefore, the upper limit value of r is preferably not more than a specific value in the following order (a smaller numerical value is preferable). That is, 200 or less, 120 or less, 80 or less, 60 or less, 40 or less, 30 or less, or 28 or less is preferable.
The average chain length of polyalkylene glycol chains (average number of moles of oxyalkylene group added) refers to the unsaturated polyalkylene glycol monomer (a) possessed by the polycarboxylic acid copolymer in the present invention. It means the average value of the number of moles of oxyalkylene groups added to 1 mole of the derived polyalkylene glycol chain.

In the general formula (1), R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and the hydrophobicity increases as the number of carbon atoms of the hydrocarbon group increases, and the dispersion performance is sufficient. Therefore, the number of carbon atoms of the hydrocarbon group is preferably 1-20. More preferably, it is 1-12, More preferably, it is 1-10, More preferably, it is 1-6, Most preferably, it is 1-4.
As the hydrocarbon group, for example, an alkyl group (straight chain, branched chain or cyclic), a phenyl group, an alkyl-substituted phenyl group, an alkenyl group, an alkynyl group, an aryl and the like are preferable. Of these, an alkyl group (straight chain, branched chain or cyclic) is preferable.
R ¹ is particularly preferably a hydrogen atom, a methyl group or an ethyl group.

In the general formula (1), q is 0 or 1, but when q represents 0, the monomer (a) represented by the general formula (1) is a monomer having an ether structure. (Ether type monomer), and when q represents 1, it is a monomer having an ester structure (ester type monomer).

When the monomer (a) represented by the general formula (1) is an ester monomer, specific examples of the monomer include a polyalkylene glycol ester monomer, that is, an unsaturated group, Examples thereof include compounds having a structure in which a polyalkylene glycol chain is bonded via an ester bond. For example, unsaturated carboxylic acid polyalkylene glycol ester compounds are suitable. Among these, (alkoxy) polyalkylene glycol mono (meth) acrylate is preferable.

Examples of the (alkoxy) polyalkylene glycol mono (meth) acrylate include, for example, alkoxy polyalkylene glycols obtained by adding 2 to 25 mol of an oxyalkylene group having 2 to 18 carbon atoms to alcohols, particularly oxyethylene groups. Esterified products of alkoxy polyalkylene glycols and (meth) acrylic acid are preferred. The phrase “mainly composed of oxyethylene groups” means that 50% or more of the oxyalkylene groups in the (alkoxy) polyalkylene glycol mono (meth) acrylate are oxyethylene groups. More preferably, 80% or more of the oxyalkylene groups are oxyethylene groups, and more preferably 100% of the oxyalkylene groups are oxyethylene groups.
Examples of the alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, and 2-hexanol. C1-C30 aliphatic alcohols such as 3-hexanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol and stearyl alcohol; C3-C30 fats such as cyclohexanol Cyclic alcohols; unsaturated alcohols having 3 to 30 carbon atoms such as (meth) allyl alcohol, 3-buten-1-ol, 3-methyl-3-buten-1-ol, and the like.

Specifically, the following (alkoxy) polyethylene glycol (poly) (C2-C4 alkylene glycol) (meth) acrylic acid esters and the like are preferable as the esterified product.
Methoxy polyethylene glycol mono (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, methoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol (Poly) butylene glycol} mono (meth) acrylate, ethoxypolyethyleneglycol mono (meth) acrylate, ethoxy {polyethyleneglycol (poly) propyleneglycol} mono (meth) acrylate, ethoxy {polyethyleneglycol (poly) butyleneglycol} mono (meta ) Acrylate, ethoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (Meth) acrylate, propoxy polyethylene glycol mono (meth) acrylate, propoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, propoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, propoxy {polyethylene glycol ( Poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate,
Butoxy polyethylene glycol mono (meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, butoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol (Poly) butylene glycol} mono (meth) acrylate, pentoxypolyethylene glycol mono (meth) acrylate, pentoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, pentoxy {polyethylene glycol (poly) butylene glycol} mono ( Meth) acrylate, pentoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol } Mono (meth) acrylate,

Hexoxypolyethylene glycol mono (meth) acrylate, hexoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, hexoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, hexoxy {polyethylene glycol (poly) propylene Glycol (poly) butylene glycol} mono (meth) acrylate, heptoxypolyethylene glycol mono (meth) acrylate, heptoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, heptoxy {polyethylene glycol (poly) butylene glycol} mono (Meth) acrylate, heptoxy {polyethylene glycol (poly) propylene glycol (poly) butylene Recall} mono (meth) acrylate, octoxypolyethylene glycol mono (meth) acrylate, octoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, octoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, Octoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate, nonanoxy polyethylene glycol mono (meth) acrylate, nonanoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, nonanoxy {polyethylene Glycol (poly) butylene glycol} mono (meth) acrylate, nonanoxy {polyethylene glycol (poly Propylene glycol (poly) butylene glycol} mono (meth) acrylate.

When the monomer (a) represented by the general formula (1) is an ether monomer, specific examples of the monomer include an unsaturated alcohol polyalkylene glycol adduct, that is, an unsaturated group. Examples thereof include compounds having a structure in which a polyalkylene glycol chain is added to an alcohol having an unsaturated alcohol. Such a compound can be obtained, for example, by adding an alkylene glycol (alkylene oxide) to an unsaturated alcohol.
The unsaturated alcohol is represented by the following general formula (3):
YO (AO) _s H (3)
(In the formula, Y corresponds to “CH ₂ ═C (R ² ) — (CH ₂ ) _p —” in the general formula (1). S is an average addition of an oxyalkylene group represented by AO) The number of moles is a number of 0 to 300. AO is the same as AO in the general formula (1).

In the said General formula (3), although s is a number of 0-300, as a range of s, 0-200 are preferable. More preferably, it is 0-100, More preferably, it is 0-50, More preferably, it is 0-25, Especially preferably, it is 0-10, Most preferably, it is 0-4. It is also preferable that s is 1 or more. When s is 1 or more, 1-50 are preferable. More preferably, it is 1-25, More preferably, it is 1-10, More preferably, it is 1-5, More preferably, it is 1-3, Most preferably, it is 1-2, Most preferably, it is 1. Furthermore, it is preferable that s is 0. When s is 0, in the compound represented by the general formula (3), Y corresponds to an unsaturated alcohol having 2 to 5 carbon atoms.

Specific examples of the unsaturated alcohol include, for example, alcohols such as methallyl alcohol, allyl alcohol, and 3-methyl-3-buten-1-ol, and alkylene oxide adducts of these alcohols. As the adduct, those having a relatively small average added mole number p are preferable.
Among the above unsaturated alcohols, methallyl alcohol, allyl alcohol, 3-methyl-3-buten-1-ol, methallyl alcohol-1EO (one mole of ethylene oxide added to methallyl alcohol), allyl alcohol-1EO (One mole of ethylene oxide added to allyl alcohol), 3-methyl-3-buten-1-ol-1EO (one mole of ethylene oxide added to 3-methyl-3-buten-1-ol), Methallyl alcohol-2EO (two moles of ethylene oxide added to methallyl alcohol), allyl alcohol-2EO (two moles of ethylene oxide added to allyl alcohol), 3-methyl-3-buten-1-ol- 2EO (3-methyl-3-buten-1-ol and ethylene Kisaido 2 mol addition to ones) are more preferable.

As said alkylene oxide, a C2-C18 alkylene oxide is preferable. More preferably, it is a C2-C8 alkylene oxide, for example, ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, styrene oxide, etc. are mentioned. Among these, alkylene oxides having 2 to 4 carbon atoms are preferable, and ethylene oxide is particularly preferable. Two or more kinds of alkylene oxides may be used. In this case, the addition reaction may be in any form such as random addition, block addition, and alternate addition.

Specific examples of the unsaturated alcohol polyalkylene glycol adduct include, for example, vinyl alcohol alkylene oxide adduct, (meth) allyl alcohol alkylene oxide adduct, 3-buten-1-ol alkylene oxide adduct, isoprene alcohol (3 -Methyl-3-buten-1-ol) alkylene oxide adduct, 3-methyl-2-buten-1-ol alkylene oxide adduct, 2-methyl-3-buten-2-ol alkylene oxide adduct, 2- Methyl-2-buten-1-ol alkylene oxide adduct and 2-methyl-3-buten-1-ol alkylene oxide adduct are preferred.

More specifically, for example, polyethylene glycol monovinyl ether, polyethylene glycol monoallyl ether, polyethylene glycol mono (2-methyl-2-propenyl) ether, polyethylene glycol mono (2-butenyl) ether, polyethylene glycol mono (3-methyl) -3-butenyl) ether, polyethylene glycol mono (3-methyl-2-butenyl) ether, polyethylene glycol mono (2-methyl-3-butenyl) ether, polyethylene glycol mono (2-methyl-2-butenyl) ether, polyethylene Glycol mono (1,1-dimethyl-2-propenyl) ether, polyethylene polypropylene glycol mono (3-methyl-3-butenyl) ether, methoxypolyethylene glycol mono 3-methyl-3-butenyl) ether, ethoxy polyethylene glycol mono (3-methyl-3-butenyl) ether, 1-propoxy polyethylene glycol mono (3-methyl-3-butenyl) ether, cyclohexyloxypolyethylene glycol mono (3- Methyl-3-butenyl) ether, phenoxypolyethyleneglycol mono (3-methyl-3-butenyl) ether, methoxypolyethyleneglycolmonoallylether, ethoxypolyethyleneglycolmonoallylether, phenoxypolyethyleneglycolmonoallylether, methoxypolyethyleneglycolmono (2 -Methyl-2-propenyl) ether, ethoxypolyethylene glycol mono (2-methyl-2-propenyl) ether, phenoxypolyethylene Glycol mono (2-methyl-2-propenyl) ether and the like.

<Unsaturated carboxylic acid monomer (b)>
The monomer (b) is a monomer containing an unsaturated double bond (carbon-carbon double bond) and a carboxyl group and / or a carboxylate. The structural unit (B) derived from the unsaturated carboxylic acid monomer (b) means a structure in which the unsaturated double bond portion of the monomer (b) is a single bond.

Here, including a carboxyl group and / or a carboxylate salt means that a group represented by —COOZ (Z represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group) is 1 per molecule. It means having one or more. Examples of metal atoms include alkali metals such as sodium, lithium, potassium, rubidium and cesium; alkaline earth metals such as magnesium, calcium, strontium and barium; aluminum and iron. Organic amine groups include monoethanolamine groups, diethanolamine groups, triethanolamine groups and other alkanolamine groups; monoethylamine groups, diethylamine groups, triethylamine groups and other alkylamine groups; ethylenediamine groups, triethylenediamine groups and other polyamines Groups and the like. Among these, the carboxylate is preferably an ammonium salt, a sodium salt, or a potassium salt, and more preferably a sodium salt.

The unsaturated carboxylic acid monomer (b) includes an unsaturated monocarboxylic acid monomer containing an unsaturated double bond and one carboxyl group or carboxylate in one molecule, An unsaturated dicarboxylic acid monomer containing an unsaturated double bond and two carboxyl groups or a carboxylate is preferable.

Specific examples of the unsaturated monocarboxylic acid monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, α-hydroxyacrylic acid, α-hydroxymethylacrylic acid and derivatives thereof, These salts are mentioned.
Specific examples of the unsaturated dicarboxylic acid-based monomer include unsaturated dicarboxylic acids such as maleic acid, itaconic acid, citraconic acid, fumaric acid, and mesaconic acid, salts thereof, and anhydrides thereof. Can be mentioned.
Among these, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid and salts thereof are preferable from the viewpoint of polymerizability. Of these, acrylic acid, methacrylic acid, and salts thereof are more preferable. That is, the carboxylic acid monomer (b) preferably includes (meth) acrylic acid or a salt thereof. More preferably, it is methacrylic acid or a salt thereof. By including a structure derived from (meth) acrylic acid or a salt thereof, the resulting polycarboxylic acid copolymer in the present invention has a further excellent dispersion performance in a smaller amount. It becomes possible to demonstrate.
Acrylic acid and methacrylic acid are collectively referred to as “(meth) acrylic acid”.

<Other monomer (c)>
As described above, the polycarboxylic acid copolymer in the present invention is also a structural unit (C) derived from the monomer (c) other than the above (a) and (b) which is an essential monomer component. ) May be included. Such a monomer (c) may be any monomer that can be copolymerized with the monomer (a) and / or (b), and includes, for example, one or more of the following compounds. Can be used.
Half esters and diesters of the above unsaturated dicarboxylic acid monomers and alcohols having 1 to 30 carbon atoms; Half amides and diamides of the above unsaturated dicarboxylic acid monomers and amines having 1 to 30 carbon atoms Half esters and diesters of an alkyl (poly) alkylene glycol obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine and the unsaturated dicarboxylic acid monomer; Half esters and diesters of saturated dicarboxylic dicarboxylic acid monomers and alkylene glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of the alkylene glycol; methyl (meth) acrylate, ethyl (meta ) Acrylate, propyl (meth) acrylate, glycidyl Esters of unsaturated monocarboxylic acids such as (meth) acrylate, methyl crotonate, ethyl crotonate, propyl crotonate and alcohols having 1 to 30 carbon atoms; alcohols having 1 to 30 carbon atoms and 2 to 18 carbon atoms Esters of alkoxy (poly) alkylene glycols to which 1 to 500 moles of alkylene oxide have been added and unsaturated monocarboxylic acids such as (meth) acrylic acid; (poly) ethylene glycol monomethacrylate, (poly) propylene glycol monomethacrylate, 1-500 molar adducts of alkylene oxides having 2-18 carbon atoms to unsaturated monocarboxylic acids such as (meth) acrylic acid, such as (poly) butylene glycol monomethacrylate;

Half amides of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols; triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) (Poly) alkylene glycol di (meth) acrylates such as acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate; hexanediol di (meth) acrylate, trimethylolpropane Multifunctional (meth) acrylates such as tri (meth) acrylate and trimethylolpropane di (meth) acrylate; (poly) alkyl such as triethylene glycol dimaleate and polyethylene glycol dimaleate Glycol dimaleates; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (Meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate, (meth) acrylamide methylsulfonic acid, (meth) acrylamide Unsaturated sulfonic acids such as ethyl sulfonic acid, 2-methylpropane sulfonic acid (meth) acrylamide, styrene sulfonic acid and the like, and monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts thereof; ) Amides of unsaturated monocarboxylic acids with amines having 1 to 30 carbon atoms such as acrylamide; styrene, alpha-methyl styrenes, vinyl toluene, p- methyl vinyl aromatics such as styrene;

Dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene; (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, Unsaturated amides such as N-dimethyl (meth) acrylamide; unsaturated cyanides such as (meth) acrylonitrile and α-chloroacrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate , Unsaturated amines such as methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, vinylpyridine, and the like; Divinyl aromatics such as triallyl cyanurate Anurates; Allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; Unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; Methoxypolyethylene glycol monovinyl ether, Polyethylene glycol monovinyl ether, Methoxypolyethylene glycol mono Vinyl ethers or allyl ethers such as (meth) allyl ether and polyethylene glycol mono (meth) allyl ether; polydimethylsiloxanepropylaminomaleamic acid, polydimethylsiloxaneaminopropylaminomaleamic acid, polydimethylsiloxane-bis- (propylamino) Maleamic acid), polydimethylsiloxane-bis- (dipropyleneamino maleamic acid), polydimethylsiloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1-propyl) Siloxane derivatives such as -3-methacrylate).

Next, a method for obtaining the polymer will be described.
As a method for obtaining the polymer, a method usually used in the technical field of the present invention can be employed. For example, as a method for obtaining the polycarboxylic acid-based copolymer in the present invention, a polymerization initiator can be used. The monomer component containing the monomer (a) and the monomer (b) and, if necessary, the monomer (c) may be copolymerized, but the polycarboxylic acid copolymer in the present invention It is preferable to appropriately set the type and amount of the monomer contained in the monomer component so that the structural unit constituting the component falls within the above-described range. That is, the type and amount of the monomer contained in the monomer component are appropriately set so that the proportion of the constituent units constituting the polycarboxylic acid copolymer in the present invention falls within the above-described preferred range. Is preferred.

Therefore, the content of each of the monomers (a) and (b) is 1% by mass or more with respect to 100% by mass of the total monomer components used for obtaining the polycarboxylic acid copolymer in the present invention. Is preferable. Further, the content ratio of the monomer (a) in the total amount of 100% by mass of the monomers (a) and (b) is preferably 60 to 96% by mass, more preferably 70 to 95% by mass, More preferably, it is 80-94 mass%, Most preferably, it is 84-94 mass%. Further, the content ratio of the monomer (b) in the total amount of the monomers (a) and (b) of 100% by mass is preferably 3 to 50% by mass, more preferably 3 to 35% by mass, More preferably, it is 4-30 mass%, More preferably, it is 4-25 mass%, Most preferably, it is 4-14 mass%.

The total ratio (mass%) of the monomers (a) and (b) is preferably 70 to 100 mass% with respect to 100 mass% of all monomer components. That is, it is preferable that the content rate of another monomer (c) is 0-30 mass% with respect to 100 mass% of all the monomer components. The total ratio of the monomers (a) and (b) in 100% by mass of all monomer components is more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass. %.

Further, in order to obtain a high yield of the polycarboxylic acid copolymer in the present invention having a high dispersion performance, the proportion of the monomer (a) is 50 mol% with respect to 100 mol% of all monomer components. It is preferable that: More preferably, it is 49 mol% or less.

The copolymerization can be performed by a usual method such as solution polymerization or bulk polymerization. The solution polymerization can be carried out either batchwise or continuously. Examples of the solvent used here include water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n- Examples include aromatic or aliphatic hydrocarbons such as hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; and cyclic ether compounds such as tetrahydrofuran and dioxane. Among these, from the viewpoint of the solubility of the raw material monomer and the resulting polymer, it is preferable to use at least one selected from the group consisting of water and a lower alcohol having 1 to 4 carbon atoms. It is more preferable in that the solvent step can be omitted.

When the copolymerization is performed by an aqueous solution polymerization method, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate; hydrogen peroxide; 2 Azoamidine compounds such as 2,2′-azobis-2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, 2-carbamoylazoiso It is preferable to use a water-soluble azo initiator such as an azonitrile compound such as butyronitrile. In addition, at this time, alkali metal sulfites such as sodium hydrogen sulfite, metabisulfite, sodium hypophosphite, Fe (II) salts such as molle salt, sodium hydroxymethanesulfinate dihydrate, hydroxylamine hydrochloride, Accelerators such as thiourea, L-ascorbic acid (salt), and erythorbic acid (salt) can also be used in combination. Among these, a combination of hydrogen peroxide and an accelerator such as L-ascorbic acid (salt) is preferable. These radical polymerization initiators and accelerators may be used alone or in combination of two or more.

In the copolymerization, the reaction temperature is not particularly limited. For example, when persulfate is used as the initiator, the reaction temperature is preferably in the range of 30 to 100 ° C, more preferably in the range of 40 to 95 ° C, and 45 to 45 ° C. A range of 90 ° C. is more preferable. Further, when hydrogen peroxide and L-ascorbic acid (salt) as a promoter are combined to form an initiator, the reaction temperature is preferably in the range of 30 to 100 ° C, more preferably in the range of 40 to 95 ° C, and 45 to 45 ° C. A range of 90 ° C. is more preferable.
Although the polymerization time in the case of copolymerization is not specifically limited, For example, the range of 0.5 to 10 hours is preferable. If the polymerization time is too long or too short than this range, the polymerization rate may be lowered or the productivity may be lowered, which is not preferable. More preferably, it is 0.5-8 hours, More preferably, it is the range of 1-6 hours.
The amount of all monomer components used in the copolymerization is preferably in the range of 10 to 99% by mass with respect to 100% by mass of all the raw materials including other raw materials and the polymerization solvent. In particular, if the amount of all the monomer components used is too lower than this range, it is not preferred because it may cause a decrease in polymerization rate or a decrease in productivity. More preferably, it is 20-98 mass%, More preferably, it is 25-95 mass%, More preferably, it is 30-90 mass%, Especially preferably, it is 30-80 mass%, Most preferably, it is the range of 40-70 mass%.

In the copolymerization, a chain transfer agent can be used for adjusting the molecular weight of the polycarboxylic acid copolymer obtained in the present invention. In particular, it is preferable to use a chain transfer agent when the polymerization reaction is performed at a high concentration of 30% by mass or more with respect to 100% by mass of the total amount of raw materials used during polymerization. . Examples of chain transfer agents include mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, etc. These thiol chain transfer agents can be used, and two or more types of chain transfer agents can be used in combination. Furthermore, in order to adjust the molecular weight of the copolymer, it is also effective to use a monomer having high chain mobility such as (meth) allylsulfonic acid (salt) as the monomer (d).

In the above copolymerization reaction, when a solvent is used, the polymerization may be carried out at a pH of 5 or more. In this case, the polymerization rate is lowered and the copolymerizability is not sufficiently improved. Since there is a possibility that the dispersibility of the oxide cannot be improved sufficiently, the copolymerization reaction is preferably performed at a pH of less than 5. The pH can be adjusted by, for example, inorganic salts such as hydroxides or carbonates of monovalent metals or divalent metals; ammonia; alkaline substances such as organic amines or inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, acetic acid, It can carry out using organic acids, such as p-toluenesulfonic acid.

The polycarboxylic acid copolymer in the present invention can be used as it is as a component of the electrode composition, but it is preferable to adjust the pH to 5 or more from the viewpoint of handleability. As described above, the copolymerization reaction is preferably performed at a pH of less than 5, and the pH is preferably adjusted to 5 or more after the copolymerization. The pH can be adjusted using, for example, an inorganic salt such as a monovalent metal or divalent metal hydroxide or carbonate; ammonia; an alkaline substance such as an organic amine. Further, after the reaction is completed, the concentration can be adjusted if necessary. Further, the polycarboxylic acid copolymer in the present invention may be used as a component of the electrode composition as it is in the form of an aqueous solution, or neutralized with a hydroxide of a divalent metal such as calcium or magnesium. It may be used after being made into a polyvalent metal salt and then dried, or supported on an inorganic powder such as silica fine powder and dried.

The weight average molecular weight (Mw) of the polymer (polycarboxylic acid copolymer in the present invention) is preferably 500,000 or less. More preferably, it is 300,000 or less, More preferably, it is 200,000 or less, Most preferably, it is 100,000 or less. Moreover, it is preferable that Mw is 3000 or more from the viewpoint that it is easier to exhibit dispersion performance when adsorbed to a single metal and / or metal oxide to some extent, and that the adsorption power increases as Mw increases. More preferably, it is 5000 or more, More preferably, it is 7000 or more, Especially preferably, it is 10,000 or more, Most preferably, it is 20,000 or more.
The weight average molecular weight of the polymer can be determined by gel permeation chromatography (GPC) analysis.

The metal simple substance and / or metal oxide may be any metal simple substance and / or metal oxide other than the active material. The metal in the simple metal and / or metal oxide is at least one element selected from the group consisting of metal elements belonging to Groups 1 to 15 of the periodic table, that is, Ag, Al, Au, Ba, Be, Bi , Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, In, K, Li, Mg, Mn, Mo, Na, Nb, Ni, Pd, Pt, Pb, Rb , Ru, Sc, Sn, Sr, Sb, Ta, Ti, Tl, V, W, Y, Zr, lanthanoid and the like. More preferably, at least one element selected from the group consisting of metal elements belonging to Groups 1 to 6, 10 to 15 of the periodic table, that is, Ag, Al, Au, Ba, Be, Bi, Ca, Cd, Ce, Cr, Cs, Cu, Ga, Ge, Hf, Hg, In, K, Li, Mg, Mo, Na, Nb, Ni, Pd, Pt, Pb, Rb, Sc, Sn, Sr, Sb, Ta, It is at least one element selected from the group consisting of Ti, Tl, V, W, Y, Zr, and lanthanoid. More preferably, Ag, Al, Au, Ba, Bi, Ca, Cd, Ce, Cr, Cs, Cu, Ga, Ge, In, K, Li, Mg, Na, Nb, Ni, Pd, Pb, Sc, It is at least one element selected from the group consisting of Sr, Sb, Ta, Ti, Tl, W, Y, Zr, and a lanthanoid. Particularly preferred is at least one selected from the group consisting of Bi, Ga, In, Pb, Sn and Tl. In other words, the metal in the metal electrode and / or metal oxide in the battery electrode composition of the present invention is at least one selected from the group consisting of indium, thallium, tin, bismuth, lead, and gallium. It is particularly preferred.

Specific examples of the metal oxide include silver oxide, aluminum oxide, barium oxide, bismuth oxide, bismuth-containing composite oxide, calcium oxide, calcium-containing composite oxide, lanthanum oxide / cerium oxide / cerium-containing composite oxide. Products, cerium-containing solid solutions, lanthanoid oxides such as ytterbium oxide, cobalt oxide, cesium oxide, gallium oxide, indium oxide, indium-containing composite oxides, tin oxide, potassium oxide, lithium oxide, magnesium oxide, sodium oxide, niobium oxide, oxide Neodymium, lead oxide, tin oxide, scandium oxide, antimony oxide, titanium oxide, manganese oxide, yttrium oxide, zirconium oxide, zirconium oxide stabilized with scandium oxide, zirconium oxide stabilized with yttrium oxide, zirconium Bromide-containing composite oxide, chromium oxide, germanium oxide, rubidium oxide, strontium oxide, vanadium oxide, nickel oxide, thallium oxide, gold oxide, palladium oxide, copper oxide, cadmium oxide, tungsten oxide. Among these, bismuth oxide, bismuth-containing composite oxide, gallium oxide, indium oxide, indium-containing composite oxide, lead oxide, thallium oxide, and tin oxide are preferable.

The average particle size (primary particle size) of the metal simple substance and / or metal oxide in the battery electrode composition of the present invention is preferably 100 μm or less. More preferably, it is 10 micrometers or less, More preferably, it is 1 micrometer or less. On the other hand, the average particle size is preferably 1 nm or more. More preferably, it is 5 nm or more, More preferably, it is 10 nm or more. The average particle diameter can be determined by measuring, for example, 1,000,000 to 5,000,000 simple metals and / or metal oxides with a particle size distribution meter using a light scattering method.

The metal simple substance and / or metal oxide preferably has a specific surface area of 0.01 m ² / g or more. More preferably, it is 0.1 m < ² > / g or more, More preferably, it is 0.5 m < ² > / g or more. Moreover, it is preferable that this specific surface area is 500 m < ² > / g or less. The specific surface area can be measured by a specific surface area measuring apparatus or the like by a nitrogen adsorption BET method.

The ratio of the metal simple substance and / or the metal oxide in the battery electrode composition of the present invention is 0.1% by mass or more with respect to 100% by mass of the active material in the battery electrode composition of the present invention. Is preferred. More preferably, it is 1 mass% or more, More preferably, it is 3 mass% or more. Moreover, it is preferable that the said ratio is 20 mass% or less. More preferably, it is 10 mass% or less, More preferably, it is 8 mass% or less.

The battery electrode composition of the present invention preferably further contains a binder.
The binder is, for example, a hydrocarbon site-containing polymer; an aromatic group-containing polymer; an ether group-containing polymer; a hydroxyl group-containing polymer; an amide group-containing polymer; an imide group-containing polymer; a carboxyl group-containing polymer; Polymers: Polymers bonded by ring opening of epoxy groups such as epoxy resins; Polymers containing sulfonate sites; Polymers containing quaternary ammonium salts or quaternary phosphonium salts; Used for cation / anion exchange membranes, etc. Natural rubber; Artificial rubber; Sugar; Amine group-containing polymer; Carbamate group site-containing polymer; Carbamide group site-containing polymer; Epoxy group site-containing polymer; Heterocycle and / or ionized heterocycle site Containing polymer; Polymer alloy; Heteroatom Yes polymers; low molecular weight surfactants, and the like. Of these, halogen-containing polymers are preferred. More preferably, it is a fluororesin. Examples of the fluororesin include a fully fluorinated resin in which all hydrogen atoms are substituted with fluorine atoms in the hydrocarbon moiety-containing polymer, and a partially fluorinated resin in which some hydrogen atoms are substituted with fluorine atoms in the hydrocarbon moiety-containing polymer. However, a fully fluorinated resin is more preferable. A homopolymer or a copolymer may be used, but polytetrafluoroethylene is particularly preferable.

The above-mentioned binder is a radical polymerization, radical (alternate) copolymerization, anion polymerization, anion (alternate) copolymerization, cation polymerization, cation (alternate) copolymerization, graft polymerization, graft (alternate), from monomers corresponding to the structural unit. Copolymerization, living polymerization, living (alternate) copolymerization, dispersion polymerization, emulsion polymerization, suspension polymerization, ring-opening polymerization, cyclization polymerization, polymerization by light, ultraviolet ray or electron beam irradiation, metathesis polymerization, electrolytic polymerization, etc. Can do. When the binder has a functional group, it may have a main chain and / or a side chain, and may exist as a binding site with a crosslinking agent. 1 type may be used for a binder and 2 or more types may be used for it.
The binder may be an ester bond, amide bond, ionic bond, van der Waals bond, agostic interaction, hydrogen bond, acetal bond, ketal bond, ether bond, peroxide bond, carbon-carbon bond, carbon- It may be cross-linked through a nitrogen bond, a carbon-oxygen bond, a carbon-sulfur bond, a carbamate bond, a thiocarbamate bond, a carbamide bond, a thiocarbamide bond, an oxazoline moiety-containing bond, a triazine bond, or the like. However, when the crosslinked binder has water absorption, cracks may occur in the electrode formed using the electrode composition of the present invention. Therefore, the crosslinked binder should not have water absorption.

The binder preferably has a weight average molecular weight of 200 to 7000000. Thereby, the ion conductivity of the electrode formed using the electrode composition of this invention, a flexibility, etc. can be adjusted. The weight average molecular weight is more preferably 400 to 6500000, and still more preferably 500 to 5000000.
The weight average molecular weight can be measured by gel permeation chromatography (GPC) or a UV detector.

The ratio of the binder in the battery electrode composition of the present invention is preferably 10% by mass or more with respect to 100% by mass of the active material in the battery electrode composition of the present invention. More preferably, it is 30 mass% or more, More preferably, it is 50 mass% or more. Especially preferably, it is 80 mass% or more. Moreover, it is preferable that it is 300 mass% or less. More preferably, it is 250 mass% or less, More preferably, it is 150 mass% or less. Especially preferably, it is 120 mass% or less. Thereby, the effect which makes it difficult to produce the crack of the electrode formed using the electrode composition of this invention is also exhibited, and the effect of this invention can be made remarkable.

The active material according to the present invention may be a positive electrode active material or a negative electrode active material, but is preferably a negative electrode active material.

When the battery electrode composition of the present invention is a negative electrode composition, the active material of the negative electrode includes carbon species, lithium species, sodium species, magnesium species, zinc species, tin species, silicon-containing materials, hydrogen storage alloys Materials and the like that are commonly used as negative electrode active materials for batteries can be used. Among these, it is preferable that the negative electrode active material contains a zinc species. Here, the zinc species refers to a zinc-containing compound. The zinc species may be repeatedly oxidized and reduced by driving the battery as long as it contains zinc.

The active material (zinc-containing compound) containing the above zinc species is, for example, zinc oxide, conductive zinc oxide, zinc metal, zinc powder, zinc fiber, zinc hydroxide, zinc sulfide, tetrahydroxyzinc alkali metal salt, tetra Hydroxyzinc alkaline earth metal salt, zinc halide such as zinc fluoride, zinc carboxylate compound, zinc alloy, zinc borate, zinc phosphate, zinc hydrogen phosphate, zinc silicate, zinc aluminate, carbonate, carbonate Zinc (alloy) compounds, organic zinc compounds, and zinc compounds having at least one element selected from the group consisting of elements belonging to Groups 1 to 17 of the periodic table represented by hydrogen salts, nitrates, sulfates, etc. Examples include salts.

When the battery electrode composition of the present invention is a positive electrode composition, as the positive electrode active material, those normally used as the positive electrode active material of a primary battery or a secondary battery can be used. Examples include nickel-containing compounds such as nickel oxyhydroxide, nickel hydroxide, and cobalt-containing nickel hydroxide; manganese-containing compounds such as manganese dioxide; silver oxide; lithium-containing compounds such as lithium cobaltate; iron-containing compounds. Among these, it is preferable that the active material of the positive electrode contains a nickel species.

Examples of the shape of the active material particles include fine powder, powder, granule, fine granule, scaly, fiber, granule, polyhedron, rod, rectangular, cylindrical, curved surface-containing, and the like. It is done.

As a compounding quantity of the said active material, it is preferable that it is 0.001-99.999 mass% with respect to 100 mass% of whole quantity of the electrode composition for batteries. More preferably, it is 10 mass% or more, More preferably, it is 40 mass% or more. Moreover, More preferably, it is 80 mass% or less, More preferably, it is 60 mass% or less.

The battery electrode composition of the present invention may further contain a conductive additive. Examples of the conductive auxiliary include conductive carbon, conductive ceramic, zinc used in zinc powder, zinc powder, zinc alloy, (alkaline) dry batteries and air batteries (hereinafter also referred to as metal zinc). Can be used. Conductive carbon includes graphite, glassy carbon, amorphous carbon, graphitizable carbon, non-graphitizable carbon, carbon nanofoam, activated carbon, graphene, nanographene, graphene nanoribbon, fullerene, carbon black, carbon fiber, fibrous carbon, carbon Nanotubes, carbon nanohorns, Vulcan, ketjen black, acetylene black and the like can be mentioned.

When the battery electrode composition of the present invention contains a conductive assistant, the blending amount of the conductive assistant is 0.001 to 99.999 mass% with respect to 100 mass% of the active material in the battery electrode composition. Preferably there is. When metallic zinc is used as a conductive aid during the preparation of the battery electrode composition, metallic zinc is not a component that acts as an active material, but is calculated as a conductive aid. In addition, metal zinc generated during charging / discharging from zinc oxide or zinc hydroxide, which is a zinc-containing compound, can also be used as a conductive aid in the system, but in that case, the battery electrode composition of The zinc-containing compound used at the time of preparation is calculated as a component that acts as an active material. When the amount of the conductive additive is within such a range, the battery electrode formed from the battery electrode composition exhibits better battery performance when used as a battery electrode. More preferably, it is 0.01-99.99 mass%, More preferably, it is 0.05-99.99 mass%.

The battery electrode composition of the present invention may contain components other than the binder, the component acting as an active material, and the conductive auxiliary agent as long as the effects of the present invention can be exhibited. Examples of other components include a solvent.

As said solvent, 1 type, or 2 or more types, such as water; Alcohol, such as methanol, ethanol, and propanol, is mentioned.

When the battery electrode composition of the present invention contains a solvent, the blending ratio of the solvent is preferably 0.01 to 40% by mass with respect to 100% by mass of the battery electrode composition. More preferably, it is 0.1-30 mass%.

The battery electrode composition of the present invention can be prepared by mixing the components contained in the battery electrode composition. For mixing each component, a mixer, blender, kneader, bead mill, ready mill, ball mill, or the like can be used.
In addition, after mixing, operations such as sieving may be performed in order to align the particles with a desired particle diameter.

A battery electrode constituted by using the battery electrode composition of the present invention is also one aspect of the present invention.

The battery electrode of the present invention is usually obtained by forming an active material layer on a current collector using the battery electrode composition of the present invention.

It is preferable that the ratio of the said active material in the active material layer in the battery electrode of this invention is 0.001-99.999 mass% with respect to 100 mass% of active material layers. More preferably, it is 10 mass% or more, More preferably, it is 30 mass% or more. Moreover, More preferably, it is 80 mass% or less, More preferably, it is 40 mass% or less.

A preferred ratio of the polymer, the metal simple substance and / or metal oxide, the binder, and the conductive additive in the active material layer in the battery electrode of the present invention is a preferred ratio in the battery electrode composition of the present invention. As described above.

Examples of the current collector include materials used as current collectors and containers for alkaline storage batteries and alkaline fuel cells. For example, copper foil, electrolytic copper foil, copper mesh (expanded metal), copper foam, punching Copper, brass and other copper alloys, brass foil, brass mesh (expanded metal), foamed brass, punched brass, nickel foil, nickel mesh, corrosion-resistant nickel, nickel mesh (expanded metal), punched nickel, metallic zinc, corrosion-resistant metallic zinc, Examples thereof include zinc foil, zinc mesh (expanded metal), steel plate, punched steel plate, silver and the like. These are further added with Ni, Zn, Sn, Pb, Hg, Bi, In, Tl, etc. or plated with Ni, Zn, Sn, Pb, Hg, Bi, In, Tl, etc. Also good.

The method for producing the battery electrode of the present invention is not particularly limited as long as the active material layer can be formed on the current collector using the battery electrode composition of the present invention. A method of forming an active material layer containing an active material by coating, pressing or adhering a battery electrode composition to a current collector can be used.
The battery electrode composition of the present invention may be coated, pressure-bonded, or bonded to one side of the current collector, or may be coated, pressure-bonded, or bonded to both surfaces or the entire surface.
It is preferable to dry at 0 to 250 ° C. during coating and / or after coating. More preferably, it is 15-200 degreeC as drying temperature. Drying may be performed by vacuum drying. The drying time is preferably 5 minutes to 48 hours.
The battery electrode of the present invention may be produced by repeating the coating and drying steps. Moreover, it is preferable to perform a press with a roll press machine etc. by the pressure of normal pressure-20t with a roll press machine etc. after drying of the battery electrode composition of this invention. The pressure for pressing is more preferably a pressure of normal pressure to 15 t. You may apply the temperature of 10-500 degreeC at the time of a press. The pressing process may be performed once or a plurality of times. When performing the pressing, the adhesion between the active materials and / or the active material and the binder can be improved, and the thickness of the active material layer can be adjusted.

The battery electrode of the present invention and a battery formed using the electrolyte are also one aspect of the present invention. The battery of the present invention can sufficiently bring out the function of the additive.

When only the negative electrode is the battery electrode of the present invention among the battery electrodes included in the battery of the present invention, the positive electrode used in the battery electrode composition of the present invention is used as the positive electrode active material included in the battery of the present invention. As the active material, those described above can be preferably used.
Moreover, when only the positive electrode is the battery electrode of the present invention among the battery electrodes included in the battery of the present invention, the negative electrode active material included in the battery of the present invention is used in the battery electrode composition of the present invention. What was mentioned above as an active material of a negative electrode can be used conveniently.
In addition, both the positive electrode and negative electrode with which the battery of this invention is provided may be the battery electrode of this invention.

As a form of the battery of the present invention, a primary battery, a chargeable / dischargeable secondary battery, a form using mechanical charge (mechanical replacement of a zinc negative electrode), a third electrode different from these together with a positive electrode and a negative electrode The form to utilize is mentioned.

Since the battery of the present invention can use a water-containing electrolyte as the electrolyte, a highly safe battery can be obtained. On the other hand, it is also possible to use a non-aqueous electrolyte as the electrolyte.

As the electrolytic solution, one that is usually used as an electrolytic solution for a storage battery can be used, and is not particularly limited. For example, the organic solvent-based electrolytic solution is preferably ethylene carbonate, propylene carbonate, dimethyl carbonate, or diethyl carbonate. Examples of the aqueous electrolyte include potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, and lithium hydroxide aqueous solution. Among these, an aqueous electrolyte solution is preferable, and an aqueous potassium hydroxide solution is particularly preferable. The aqueous electrolyte solution may contain the organic solvent electrolyte solution.

As the battery of the present invention, a separator can also be used. The separator is a member that separates the positive electrode and the negative electrode and holds the electrolyte solution to ensure ionic conductivity between the positive electrode and the negative electrode. There is no particular limitation as a separator, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, cellulose, cellulose acetate, hydroxyalkylcellulose, carboxymethylcellulose, polyvinyl alcohol, cellophane, polystyrene, polyacrylonitrile, polyacrylamide, polyvinyl chloride, High molecular weight polymers having micropores such as polyamide, vinylon, and poly (meth) acrylic acid, copolymers thereof, gel compounds, ion exchange membrane polymers and copolymers thereof, cyclized polymers and copolymers thereof, Poly (meth) acrylate-containing polymers and their copolymers, sulfonate-containing polymers and their copolymers, quaternary ammonium salt-containing polymers and their copolymers, quaternary phosphonium salt polymers and their copolymers Body, and the like. In the separator, silver oxide, aluminum oxide, zinc oxide, barium hydroxide, calcium oxide, calcium hydroxide, cadmium, cerium oxide, copper oxide, iron oxide, magnesium oxide, magnesium silicate, calcium silicate, nickel, hydroxide Strontium, boric acid, potassium borate, calcium borate, potassium fluoride, titanium oxide, zirconium oxide, a surfactant and the like may be contained.

In addition to the above, in the battery of the present invention, the manufacturing process and the like of the battery are not particularly limited as long as they are usually employed in the technical field of the present invention, but those described in International Publication No. 2013/027767 are not limited. It can be suitably employed.

The battery electrode composition of the present invention has the above-described configuration. When an electrode is formed using this composition, the dispersibility of the metal simple substance and / or metal oxide in the electrode is improved as compared with the conventional electrode. Thus, the effect of improving the battery performance can be increased, and the quality of the battery can be stabilized.

FIG. 1 is a graph showing the particle size distribution of bismuth oxide fine particles in a reference aqueous solution when a polymer having a carboxylate group and a polyalkylene glycol chain is not added. FIG. 2 is a graph showing the particle size distribution of bismuth oxide fine particles in an aqueous solution when a polymer having a carboxylate group and a polyalkylene glycol chain is added. FIG. 3 is a bar graph showing the Coulomb efficiency of Example 1 and Comparative Example 1 when the discharge current is 100 mA / cm ² .

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass” and “%” means “% by mass”.
The meanings of the symbols in the examples are as follows.
SMAA: sodium methacrylate PGM-25E: methoxypolyethyleneglycol methacrylate (average added mole number of ethylene oxide 25)

(Evaluation of dispersion performance of metal species by polymer)
A polymer having a carboxylate group and a polyalkylene glycol chain (PGM-25E / SMAA = 90.5 / 9.5 (mass%)) and bismuth oxide are each 1 mass% in 100 mass% of an aqueous solution. An aqueous solution for reference and an aqueous solution for reference in which only bismuth oxide was added to 1% by mass in 100% by mass of the aqueous solution without adding a polymer were compared, and the dispersibility of bismuth oxide was compared. Specifically, the particle size distribution of bismuth oxide fine particles was measured for both aqueous solutions using a particle size distribution meter (HORIBA LA950, manufactured by Horiba, Ltd.). The results are shown in FIGS. FIG. 1 is a graph showing the particle size distribution of bismuth oxide fine particles in a reference aqueous solution when a polymer having a carboxylate group and a polyalkylene glycol chain is not added. From the results of FIG. 1, the peak particle size was 13246 nm. FIG. 2 is a graph showing the particle size distribution of bismuth oxide fine particles in an aqueous solution when a polymer having a carboxylate group and a polyalkylene glycol chain is added. From the results of FIG. 2, the peak particle size was 87 nm. 1 and 2, it was found that the dispersibility of the bismuth oxide fine particles was greatly improved by adding a polymer having a carboxylate group and a polyalkylene glycol chain.

Next, the battery performance was compared as follows.
(Example 1)
A battery negative electrode using zinc oxide as the battery active material and bismuth oxide as the metal oxide was studied. Zinc oxide, bismuth oxide and an aqueous solution of polytetrafluoroethylene (60% by mass) were mixed at a mass ratio of 95: 5: 170 to prepare a mixed solution. Bismuth oxide having an average particle size of 0.1 μm was used. Among the bismuth oxides used, those having an aspect ratio of 4 or more were included. The addition of bismuth oxide improves the high rate discharge characteristics.
In addition, the average particle diameter of bismuth oxide is the average value which measured the particle diameter of 100000-55,000 bismuth oxide with the particle size distribution meter using the light-scattering method.

Furthermore, a polymer having a carboxylate group and a polyalkylene glycol chain was added to the above mixed solution so that the ratio was 0.1% by mass in 100% by mass of the battery electrode composition. A composition was prepared. The weight average molecular weight of the polymer is 31000-37000. The weight average molecular weight was determined by gel permeation chromatography (GPC) analysis.

This battery electrode composition was applied on a copper plate as a current collector, left to dry in a dry atmosphere (dew point -40 ° C. or lower) for 3 hours to form an active material layer having a thickness of 200 μm, and a zinc negative electrode Was made.
A nickel zinc battery using a known sintered nickel electrode as the positive electrode, a potassium hydroxide aqueous solution (8M) as the electrolyte, a non-woven fabric as the separator, and the positive electrode and the prepared zinc negative electrode combined through the separator. It was. The performance of this battery was measured as follows.

(Comparative Example 1)
A nickel zinc battery was prepared in the same manner as in Example 1 except that a polymer having a carboxylate group and a polyalkylene glycol chain was not added, and the performance was measured as follows.

FIG. 3 shows the respective coulomb efficiencies of the nickel-zinc battery of Example 1 and the nickel-zinc battery of Comparative Example 1 when discharged at 100 mA / cm ² . Coulomb efficiency was calculated from the ratio of the amount of charge that could be discharged to the amount of charge that was charged.
In FIG. 3, “REF” is the result of measuring the nickel zinc battery of Comparative Example 1, and “Polymer addition” is the result of measuring the nickel zinc battery of Example 1.

When these results are seen, in the nickel zinc battery of Example 1 produced using the polymer having a carboxylate group and a polyalkylene glycol chain, the Coulomb efficiency is greatly improved, and the bismuth oxide used in Comparative Example 1 It can be seen that the function of bismuth oxide, which is only the same amount, is exerted more than in Comparative Example 1. That is, as is clear from the results of the particle size distribution described above, the dispersibility of bismuth oxide is improved by the polymer having a carboxylate group and a polyalkylene glycol chain, whereby the bismuth oxide is uniformly disposed in the electrode, and bismuth oxide is thus obtained. It is proved that the battery performance improvement effect by is maximized.

The following was found from the results of the examples.
Using a battery electrode composition comprising an active material, a single metal and / or a metal oxide, and a polymer having a carboxyl group and / or a carboxylate group and a polyalkylene glycol chain, for a battery with a simple manufacturing process An electrode can be formed, and in the battery electrode, the dispersibility of the metal simple substance and / or metal oxide is improved by the polymer, and when the battery is configured using the polymer, the effect of improving the battery performance is large. It was proved that the quality of the battery can be stabilized.

In addition, in the said Example, it is for batteries containing the polymer which has a specific active material, a specific metal simple substance and / or metal oxide, a specific carboxyl group and / or carboxylate group, and a polyalkylene glycol chain. A battery electrode is formed using the electrode composition, but a battery electrode is formed using the battery electrode composition of the present invention, and the battery configured using such a battery electrode is a metal A mechanism in which the simple substance and / or metal oxide is sufficiently dispersed in the electrode, whereby the function of the simple metal and / or metal oxide can be more fully exhibited, and the effect of improving battery performance is increased. Are the same when the battery electrode composition of the present invention is used. Therefore, it can be said from the results of the above-described embodiments that the present invention can be applied in the entire technical scope of the present invention and in various forms disclosed in this specification, and can exhibit advantageous effects.

Claims (8)

A battery electrode composition comprising an active material,
The electrode composition for a battery further includes a simple metal and / or a metal oxide and a polymer.
The battery electrode composition, wherein the polymer has a carboxyl group and / or a carboxylate group, and a polyalkylene glycol chain. The polymer has a structural unit (A) derived from an unsaturated polyalkylene glycol monomer (a) and a structural unit (B) derived from an unsaturated carboxylic acid monomer (b). The battery electrode composition according to claim 1. The unsaturated polyalkylene glycol monomer (a) is represented by the following general formula (1):

(In the formula, R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R ² represents a hydrogen atom or a methyl group. AO represents an oxyalkylene group having 2 to 18 carbon atoms. P is 0, 1 or 2. q is 0 or 1. r represents the average number of added moles of the oxyalkylene group represented by AO and is a number from 2 to 300. Represented,
The unsaturated carboxylic acid monomer (b) is represented by the following general formula (2):

(In the formula, R ³ and R ⁴ are the same or different and each represents a hydrogen atom, a methyl group, or a —COOM ² group. R ⁵ represents a hydrogen atom or a methyl group. M ¹ and M ² are the same or Differently, it represents a hydrogen atom, a metal atom, an ammonium group or an amine group, wherein R ³ and R ⁴ do not simultaneously represent a —COOM ² group, and when R ⁴ represents a —COOM ² group, The battery electrode composition according to claim 2, wherein R ⁴ and -COOM ¹ group may form an acid anhydride group. The battery electrode composition according to any one of claims 1 to 3, wherein the average particle size of the single metal and / or metal oxide is 100 µm or less. The active material contains a zinc species,
The said battery electrode composition is used in order to comprise a zinc negative electrode, The battery electrode composition in any one of Claims 1-4 characterized by the above-mentioned. 6. The battery according to claim 5, wherein the metal in the simple metal and / or the metal oxide is at least one selected from the group consisting of indium, thallium, tin, bismuth, lead, and gallium. Electrode composition. A battery electrode comprising the battery electrode composition according to claim 1. A battery comprising the battery electrode according to claim 7 and an electrolyte.

Images