JPWO2019117056A1 - Binders for non-aqueous electrolyte batteries, aqueous binder solutions and slurry compositions using them, and electrodes for non-aqueous electrolyte batteries and non-aqueous electrolyte batteries. - Google Patents

Abstract

The present invention comprises a neutralizing salt of a copolymer of a vinyl alcohol and an ethylenically unsaturated carboxylic acid, and the neutralizing salt is a neutralizing salt of the copolymer and a basic substance containing a polyvalent metal. The present invention relates to a binder for a non-aqueous electrolyte battery.

Description

The present invention relates to a binder for a non-aqueous electrolyte battery, a binder aqueous solution and a slurry composition using the same, and an electrode for a non-aqueous electrolyte battery and a non-aqueous electrolyte battery.

In recent years, mobile terminals such as mobile phones, notebook personal computers, and pad-type information terminal devices have become remarkably widespread. Mobile terminals are required to be more comfortable to carry, and with the rapid progress of miniaturization, thinning, weight reduction and high performance, the batteries used in form terminals are also becoming smaller, thinner, lighter and lighter. High performance is required. Lithium-ion secondary batteries are often used as secondary batteries used as power sources for such mobile terminals. For non-aqueous electrolyte batteries such as lithium ion secondary batteries, positive and negative electrodes are installed via a separator, and LiPF ₆ , LiBF ₄ , LiTFSI (lithium (bistrifluoromethylsulfonylimide)), LiFSI (lithium (bisfluorosulfonylimide)). ))) Has a structure in which a lithium salt such as) is stored in a container together with an electrolytic solution in which a lithium salt is dissolved in an organic liquid such as ethylene carbonate.

The negative electrode and positive electrode constituting the non-aqueous electrolyte battery are usually electrodes obtained by dissolving or dispersing a binder and a thickener in water or a solvent, and mixing the active material, a conductive auxiliary agent (conductivity-imparting agent), or the like. It is formed by applying a water-based slurry (hereinafter, may be simply referred to as “slurry”) to a current collector and then drying water or a solvent to bind them as a mixed layer.

In recent years, there has been increasing interest in slurries that use water instead of solvent as electrode slurries from the viewpoint of reducing the burden on the environment and the convenience of manufacturing equipment. Especially in the production of negative electrodes, slurries that use an aqueous medium are used. The transition to is progressing rapidly. As a binder for such an aqueous medium, a system in which carboxymethyl cellulose sodium salt (CMC-Na) is added as a thickener to a diene rubber such as styrene-butadiene rubber (SBR), which is most industrially used. (For example, Patent Document 1), acrylic binders such as polyacrylic acid (for example, Patent Documents 2 and 3), polyamide / imide-based binders (for example, Patent Documents 4 and 5), and polyvinyl alcohol-based binders (for example, Patent Documents 4 and 5). , Patent Documents 6 and 7) and various types of binders are known.

JP-A-2014-13693 JP-A-2002-260667 Japanese Patent Application Laid-Open No. 2003-282061 JP 2001-68115 JP 2015-65164 JP-A-11-250915 JP-A-2017-59527

However, the conventionally used SBR / CMC-Na addition type binder is vulnerable to heat generated during charging and discharging, and has a low capacity retention rate. In addition, since it is a two-component type, it has high storage stability. There are manufacturing problems such as low concentration and complicated slurry preparation process. Further, in the acrylic binder and the polyamide / imide binder as disclosed in Patent Documents 2 to 5, the problems of poor flexibility, fragile electrodes, and high electrical resistance have not been sufficiently solved. Furthermore, polyvinyl alcohol-based binders tend to have low slurry stability because the active material tends to aggregate, and even when a water-soluble polymer such as a cellulose derivative is used in combination to improve stability, electricity is used. Due to its high resistance, it was not sufficiently satisfactory as a binder used for electrodes of non-aqueous electrolyte batteries.

Therefore, the present invention provides a binder for a non-aqueous electrolyte battery, which has excellent slurry stability and can realize low resistance when used as an electrode of a non-aqueous electrolyte battery, and has a high capacity of the battery in the non-aqueous electrolyte battery. The purpose is to improve battery characteristics such as low resistance (low resistance, high efficiency), battery life (cycle characteristics) and charging speed (rate characteristics).

The present inventors have arrived at the present invention as a result of diligent studies to solve the above problems. That is, the present invention provides the following preferred embodiments.
[1] A neutralizing salt of a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid is contained, and the neutralizing salt is a neutralizing salt of the copolymer and a basic substance containing a polyvalent metal. There is a binder for non-aqueous electrolyte batteries.
[2] The non-aqueous electrolyte battery according to the above [1], wherein the neutralizing salt is a neutralizing salt of the copolymer and a basic substance containing a polyvalent metal and a basic substance containing an alkali metal. Binder for.
[3] The binder for a non-aqueous electrolyte battery according to the above [1] or [2], wherein the polyvalent metal is a divalent metal.
[4] The content of polyvalent metal atom in the binder for a non-aqueous electrolyte battery is less than 0.5 equivalent with respect to the ethylenically unsaturated carboxylic acid unit in the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid. The binder for a non-aqueous electrolyte battery according to any one of the above [1] to [3].
[5] The total equivalent ratio of polyvalent metal atoms and alkali metal atoms to the ethylenically unsaturated carboxylic acid unit in the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid in the binder for non-aqueous electrolyte batteries is 1 or less. The binder for a non-aqueous electrolyte battery according to any one of the above [1] to [4].
[6] The binder for a non-aqueous electrolyte battery according to any one of [1] to [5] above, wherein the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid is a graft copolymer.
[7] An aqueous binder solution for a non-aqueous electrolyte battery comprising the binder for a non-aqueous electrolyte battery and water according to any one of the above [1] to [6].
[8] A slurry composition for a non-aqueous electrolyte battery comprising the binder for the non-aqueous electrolyte battery according to any one of the above [1] to [6], an active material, and water.
[9] An electrode for a non-aqueous electrolyte battery comprising a current collector including the binder for the non-aqueous electrolyte battery according to any one of [1] to [6] and a layer containing an active material.
[10] A non-aqueous electrolyte battery having the electrode for the non-aqueous electrolyte battery according to the above [9].

According to the present invention, it is possible to provide a binder for a non-aqueous electrolyte battery which is excellent in slurry stability and can realize low resistance when used as an electrode of a non-aqueous electrolyte battery. The battery characteristics of the water electrolyte battery can be improved.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited thereto.

The binder for a non-aqueous electrolyte battery of the present invention (hereinafter, also referred to as “the binder of the present invention”) contains a neutralizing salt of a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid. In the present invention, the neutralized salt of a copolymer means a neutralized product in which active hydrogen of a carbonyl acid produced from an ethylenically unsaturated carboxylic acid reacts with a basic substance to form a salt and exists as a neutralized product. .. The binder of the present invention is mainly composed of the neutralized salt, and the neutralized salt of the copolymer is usually reacted with a basic substance in the presence of a plurality of copolymers. Therefore, the binder of the present invention may also contain a copolymer that exists without forming a neutralizing salt.

By using a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid, the flexibility of the electrode can be increased as compared with the conventional acrylic binder and polyvinyl alcohol-based binder, and it is active in long-term use of the electrode. Even when the material repeatedly expands and contracts, it is difficult to crack, and an electrode having improved durability can be obtained. In the present invention, examples of the ethylenically unsaturated carboxylic acid include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, and ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid and maleic acid. Can be mentioned. Of these, acrylic acid, methacrylic acid and maleic acid are preferable from the viewpoints of availability, polymerizability, product stability and the like. One of these ethylenically unsaturated carboxylic acid esters may be used alone, or two or more thereof may be used in combination.

In the present invention, the content of ethylenically unsaturated carboxylic acid (modified amount of ethylenically unsaturated carboxylic acid) with respect to vinyl alcohol in the copolymer is preferably 0.1 to 60 mol%, preferably 1 to 50 mol%. It is more preferably%, and further preferably 5 to 35 mol%. When the content of the ethylenically unsaturated carboxylic acid with respect to vinyl alcohol is within the above range, the hydrophilicity and water solubility of the high molecular weight substance dissolved in water and the affinity for metals and ions are improved. Further, when used as an electrode of a non-aqueous electrolyte battery, there is an advantage that an appropriate toughness can be imparted to the electrode and the electric resistance can be lowered. The content (modification amount) of the ethylenically unsaturated carboxylic acid can be quantified by, for example, nuclear magnetic resonance spectroscopy (NMR).

In the present invention, the copolymerization form of the vinyl alcohol and the ethylenically unsaturated carboxylic acid copolymer is not particularly limited, and may be any of a random copolymer, an alternating copolymer, a block copolymer, a graft copolymer and the like. You may. Since the adhesiveness can be improved by arranging vinyl alcohols regularly, a block copolymer or a graft copolymer is preferable as the copolymerization form, and appropriate flexibility is obtained while maintaining high adhesiveness. Graft copolymers are more preferred because they can. Further, the graft copolymer is also advantageous in that it is easy to produce and has excellent industrial productivity.

In the present invention, the above-mentioned copolymer can be produced by a conventionally known method using polyvinyl alcohol and ethylenically unsaturated carboxylic acid as starting materials. For example, any polymerization initiation method such as anion polymerization, cationic polymerization, and radical polymerization may be used, and any method such as solution polymerization, bulk polymerization, suspension polymerization, dispersion polymerization, or emulsion polymerization may be adopted.

In the present invention, the average molecular weight of the vinyl alcohol and the ethylenically unsaturated carboxylic acid copolymer is preferably 5,000 to 250,000 in number average molecular weight, more preferably 10,000 or more, and 15 It is more preferably 000 or more, more preferably 200,000 or less, and further preferably 150,000 or less. When the number average molecular weight is at least the above lower limit value, a binder having good mechanical strength can be obtained. Further, when the number average molecular weight is not more than the above upper limit, the viscosity stability of the slurry composition is improved, the slurry is less likely to aggregate, and the slurry composition is excellent in handleability. The number average molecular weight of the copolymer in the present invention means a value measured by a gel permeation chromatography (GPC) method using polyethylene oxide and polyethylene glycol as standard substances and an aqueous column as a column.

In the binder of the present invention, the neutralizing salt of the copolymer is a neutralizing salt of the copolymer and a basic substance containing a polyvalent metal. By adopting a structure in which the carboxyl groups of the ethylenically unsaturated carboxylic acid constituting the copolymer are crosslinked with a polyvalent metal, the hydroxyl groups of the polymer constituting the binder and the hydrogen of the carboxylic acid are used as a slurry composition. Aggregation due to bonding is alleviated, and the stability of the slurry can be improved. Further, when the binder of the present invention is an aqueous solution, there is an advantage that the viscosity is increased by cross-linking and the slurry stability can be improved by suppressing aggregation.

In the present invention, the polyvalent metal means a metal having a valence of divalent or higher, and examples thereof include metals of Group 2 of the periodic table such as magnesium, calcium and barium, and aluminum. Among them, from the viewpoint of solubility in water or electrical stability, the polyvalent metal is preferably a divalent metal, more preferably magnesium and calcium. In the present invention, examples of the basic substance containing a polyvalent metal that can be used to form a neutralizing salt of a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid include carbonates such as calcium carbonate and magnesium carbonate. Salts; hydroxides such as calcium hydroxide, magnesium hydroxide, barium hydroxide, aluminum hydroxide; acetates such as magnesium acetate, calcium acetate, aluminum acetate; chlorides such as magnesium chloride, calcium chloride, aluminum chloride, etc. Can be mentioned. Of these, magnesium acetate and calcium acetate are preferable from the viewpoint of solubility in water. The basic substance containing a polyvalent metal may be used alone or in combination of two or more.

In the binder of the present invention, the content of the polyvalent metal atom is less than 0.5 equivalent with respect to the ethylenically unsaturated carboxylic acid unit in the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid. preferable. Here, in the present invention, the equivalent of the polyvalent metal atom to the ethylenically unsaturated carboxylic acid unit in the copolymer of the vinyl alcohol and the ethylenically unsaturated carboxylic acid is 1 mol of the ethylenically unsaturated carboxylic acid unit. Represents the molar amount of polyvalent metal atom relative to. When the content of the polyvalent metal atom is less than 0.5 equivalent, it is possible to suppress an increase in viscosity more than necessary, the handleability as a binder is improved, and the electrode can be easily manufactured. Further, the adhesive effect of the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid is considered to show high adhesiveness by agglomerating the polymer in a state where the dispersed active material is involved, and crosslinks with the copolymer. If the amount of polyvalent metal atoms forming the structure is too large, the cohesive force of the polymer is suppressed by the formed crosslinks, and the adhesive force tends to decrease. However, if the amount is less than 0.5 equivalent, high adhesiveness is obtained. It can be realized. Therefore, the content of the polyvalent metal atom is preferably 0.4 equivalent or less with respect to the ethylenically unsaturated carboxylic acid unit. Further, since a water-soluble copolymer salt having a small amount of alkali residue can be obtained and the adhesiveness of the electrode using the binder can be improved, the content of the polyvalent metal atom is set to the ethylenically unsaturated carboxylic acid unit. On the other hand, it is preferably 0.05 equivalent or more, and more preferably 0.08 equivalent or more.

The content of the polyvalent metal atom in the binder of the present invention is the amount of ethylenically unsaturated carboxylic acid modification of the copolymer used, the type of polyvalent metal used, and the polyvalent metal with respect to the ethylenically unsaturated carboxylic acid unit. It is appropriately determined depending on the amount of atoms and the like, and is not particularly limited, but is preferably 0.01 to 10% by mass with respect to the total mass (solid content) of the binder. It is more preferably 05 to 8% by mass, and even more preferably 0.1 to 5% by mass. When the content of the polyvalent metal atom is in the above range, high adhesiveness and slurry stability can be achieved. The solid content means a component obtained by removing the solvent from the components constituting the binder. In addition, the content of the multivalent metal atom in the binder can be measured by the method described in Examples described later.

In the binder of the present invention, the neutralizing salt of the copolymer is preferably a neutralizing salt of the copolymer and a basic substance containing a polyvalent metal and a basic substance containing an alkali metal. Since the neutralizing salt of the copolymer is composed of an alkali metal in addition to the polyvalent metal, the adhesiveness and slurry stability can be improved, and the crosslinked structure formed by the polyvalent metal with the copolymer. By forming a conductive path of metal ions (electrons), it is possible to reduce the electrical resistance and obtain a highly efficient battery. In addition, high solubility in water can be ensured, and the viscosity can be adjusted to an appropriate level without using a thickener.

Examples of the basic substance containing an alkali metal that can be used in the present invention include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide and lithium hydroxide; and carbonates of alkali metals such as sodium carbonate and potassium carbonate; Alkali metal acetates such as sodium acetate and potassium acetate; alkali metal phosphates such as trisodium phosphate and the like can be mentioned. Basic substances containing alkali metals may be used alone or in combination of two or more. Among these, lithium hydroxide and sodium hydroxide are preferable from the viewpoint of solubility in water and availability.

In the binder of the present invention, the content of the alkali metal atom can be appropriately selected depending on the use of the binder and the like, but usually, the ethylenically unsaturated carboxylic acid in the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid is used. It is preferably 0.1 to 0.9 equivalents, more preferably 0.3 to 0.8 equivalents, relative to the acid unit. Here, in the present invention, the equivalent of an alkali metal atom to an ethylenically unsaturated carboxylic acid unit in a copolymer of a vinyl alcohol and an ethylenically unsaturated carboxylic acid is the equivalent of 1 mol of the ethylenically unsaturated carboxylic acid unit. Represents the molar amount of alkali metal atoms. When the content of the alkali metal atom is within the above range, high adhesiveness of the electrode using the binder composition can be ensured, and the electric resistance can be suppressed low.

In the binder of the present invention, the total equivalent ratio (neutralization degree) of the polyvalent metal atom and the alkali metal atom to the ethylenically unsaturated carboxylic acid unit in the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid is preferable. Is 1 or less, more preferably 0.9 or less, still more preferably 0.8 or less. In the present invention, the total equivalent ratio of the polyvalent metal atom and the alkali metal atom is based on the basic substance and the alkali metal in which the active hydrogen of the carbonyl acid generated from the ethylenically unsaturated carboxylic acid constituting the binder contains the polyvalent metal. It is 1 when it reacts with the contained basic substance in just proportion to form a salt and becomes a neutralized product. On the other hand, when the amounts of the polyvalent metal atom and the alkali metal atom are excessive with respect to the ethylenically unsaturated carboxylic acid unit, the total equivalent ratio exceeds 1. When the total equivalent ratio of the polyvalent metal atom and the alkali metal to the ethylenically unsaturated carboxylic acid unit is not more than the above upper limit, high adhesiveness can be imparted to the binder, and the electrodes produced by using such a binder are collected. Since the binder has a high affinity for the electric body and is difficult to peel off, it is difficult for the battery performance to deteriorate due to peeling. This is because when the total equivalent ratio of the polyvalent metal atom and the alkali metal atom is equal to or less than the above upper limit, substantially all the polyvalent metal atom and the alkali metal atom contained in the binder form a salt with the copolymer. Therefore, it is possible to prevent the basic substance containing the metal freed in the binder and the metal not used for the formation of the neutralizing salt from acting like a lubricant and lowering the adhesiveness. it is conceivable that. Further, the lower limit of the total equivalent ratio of the polyvalent metal atom and the alkali metal atom is preferably 0.1 or more, and more preferably 0.3 or more. When the total equivalent ratio is not more than the above lower limit, there is an advantage that the acidity is low and the decomposition of the electrolytic solution can be suppressed.

The total content of polyvalent metal atom and alkali metal atom in the binder of the present invention is based on the amount of ethylenically unsaturated carboxylic acid modification of the copolymer used, the type of metal used, and the unit of ethylenically unsaturated carboxylic acid. It is appropriately determined depending on the amount of metal atoms and the like, and is not particularly limited, but is preferably 0.02 to 40% by mass with respect to the total mass (solid content) of the binder, and is 0. .1 to 28% by mass is more preferable, and 0.2 to 15% by mass is further preferable. When the total content of the polyvalent metal atom and the alkali metal atom is in the above range, high adhesiveness and slurry stability can be achieved. The content of the alkali metal in the binder can be measured by the method described in Examples described later.

In the binder of the present invention, in particular, the total equivalent ratio of the polyvalent metal atom and the alkali metal atom to the ethylenically unsaturated carboxylic acid unit is in the above range, and the content of the polyvalent metal atom is the predetermined value described above. When it is in the range of, high adhesiveness and low resistance can be ensured while maintaining high slurry stability due to the crosslinked structure formed of the polyvalent metal.

The total equivalent ratio of the polyvalent metal atom and the alkali metal atom in the binder of the present invention is such that the active hydrogen of the carbonyl acid produced from the ethylenically unsaturated carboxylic acid is a basic substance containing the polyvalent metal and a basic substance containing the alkali metal. When it reacts with a substance in just proportion to form a salt and becomes a neutralized product, that is, it becomes 1 at the neutralization point. The neutralization point can be determined by using a method such as base determination, infrared spectrum, or NMR spectrum, but it is preferable to perform base titration for simple and accurate measurement. The specific titration method is not particularly limited, but it is dissolved in water having few impurities such as ion-exchanged water and is prepared by using a basic substance such as lithium hydroxide, sodium hydroxide and potassium hydroxide. It can be carried out by neutralizing. The neutralization point indicator is not particularly limited, but an indicator such as phenolphthalein, which indicates the pH by a base, can be used.

In the present invention, the neutralized salt of a basic substance containing a vinyl alcohol, an ethylenically unsaturated carboxylic acid copolymer, a polyvalent metal, and, if necessary, a basic substance containing an alkali metal is prepared according to a known method. It can be obtained by reacting a copolymer with a basic substance, but a method of carrying out the reaction in the presence of water to obtain a neutralized product as an aqueous solution is convenient and preferable.

In the present invention, the binder may further contain additives conventionally used in the art such as thickeners and surfactants, if necessary. Such additives may include, for example, various alcohols, polyethers, celluloses, polysaccharides such as starch. In particular, by containing polyvinyl alcohol and / or a modified product thereof, the effect of enhancing the cohesiveness of the binder due to the carboxyl group and the affinity with the collector electrode and improving the adhesiveness can be expected. Further, by mixing different polymers, the molecular weight distribution is apparently broadened, and the crystallinity of the polymer is lowered, so that the effect of improving the flexibility can be expected. In addition, the effect of improving slurry stability can be expected by suppressing agglutination in a single polymer by intermolecular interaction with a different polymer. Therefore, it is advantageous to include them.

When the binder of the present invention contains polyvinyl alcohol, the saponification degree of polyvinyl alcohol is preferably 50 mol% or more, more preferably 80 mol% or more, still more preferably 95 mol% or more. When the degree of saponification is in the above range, it is less likely to be hydrolyzed by the metal contained in the binder, and stability can be maintained, which is preferable.

When the binder of the present invention contains polyvinyl alcohol, the amount of polyvinyl alcohol contained in the binder is preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably, based on the total mass of the binder. Is 20% by mass or less. When the content of polyvinyl alcohol is not more than the above upper limit, low resistance can be ensured and high charge / discharge efficiency can be realized.

The binder of the present invention may consist of a neutralized salt of a basic substance containing a vinyl alcohol, an ethylenically unsaturated carboxylic acid copolymer and a polyvalent metal, and optionally a basic substance containing an alkali metal. It is good, but the above-mentioned neutralizing salt such as the above-mentioned additives, and if present, a component different from the above-mentioned copolymer existing without forming the neutralizing salt (hereinafter, also referred to as “other components”). When the content of the other components is included, the total content of the other components is preferably 40% by mass or less, more preferably 30% by mass or less, based on the total mass of the binder.

The binder of the present invention is usually used as an aqueous binder solution composed of the above-mentioned binder and water. Therefore, the present invention is directed to the binder aqueous solution for a non-aqueous electrolyte battery containing the binder of the present invention and water.

The content of the binder in the aqueous binder solution of the present invention may be appropriately determined according to its use, desired viscosity, etc., and may be, for example, 1 to 50% by mass, preferably 1 to 50% by mass, based on the total mass of the aqueous binder solution. It is 3 to 30% by mass, more preferably 5 to 20% by mass. In other words, the content of water in the aqueous binder solution of the present invention may be, for example, 50 to 99% by mass, preferably 70 to 97% by mass, and more preferably 80 to 80% by mass, based on the total mass of the aqueous binder solution. It is 95% by mass. When the content of the binder or water is in the above range, the handleability becomes good as an aqueous solution having an appropriate viscosity.

Furthermore, the binder of the present invention can also be used as a slurry composition containing water and an active material in addition to the above-mentioned binder. Therefore, the present invention also covers a slurry composition for a non-aqueous electrolyte battery, which comprises the binder, water and active material of the present invention.

The content of the binder in the slurry composition of the present invention is usually preferably 0.1 to 15% by mass, more preferably 0.1 to 15% by mass, when the total mass of the active material contained in the slurry composition is 100. It is 0.5 to 10% by mass, more preferably 1 to 8% by mass. When the content of the binder is in the above range, the slurry composition has an appropriate viscosity, the layer thickness when applied to the current collector can be easily controlled in a desired range, and the decrease in discharge capacity can be suppressed. it can.

Further, the amount of water in the slurry composition of the present invention is usually preferably 30 to 150% by mass, more preferably 70, when the total mass of the active material contained in the slurry composition is 100. ~ 120% by mass.

In the present invention, as a solvent for dissolving the binder, instead of water or in addition to water, for example, alcohols such as methanol, ethanol, propanol and 2-propanol, and cyclic such as tetrahydrofuran and 1,4-dioxane. Ethers, amides such as N, N-dimethylformiamide, N, N-dimethylacetamide, cyclic amides such as N-methylpyrrolidone and N-ethylpyrrolidone, and sulfoxides such as dimethyl sulfoxide may be used. However, from the viewpoint of safety and environmental protection, it is preferable to contain at least water as the solvent.

Further, in the slurry composition of the present invention, in addition to the above solvent, for example, an organic solvent having a boiling point of 100 ° C. or higher and 300 ° C. or lower at normal pressure may be used in combination. Specific examples of such an organic solvent include hydrocarbons such as n-dodecane; alcohols such as 2-ethyl-1-hexanol and 1-nonanol; esters such as γ-butyrolactone and methyl lactate; N. -Amids such as methylpyrrolidone, N, N-dimethylacetamide and dimethylformamide; organic dispersion media such as sulfoxide sulfones such as dimethyl sulfoxide and sulfolane. When these organic solvents are contained, the content thereof is preferably in the range of 20% by mass or less of the total solvent.

When the slurry composition of the present invention is used for producing a negative electrode of a non-aqueous electrolyte battery, examples of the negative electrode active material include amorphous carbon, graphite, natural graphite, mesocarbon microbeads (MCMB), and pitch-based carbon fibers. Carbonaceous materials; Conductive polymers such as polyacene; Sn, Si; Composite metal oxides represented by SiO _x , SnO _x , LiTIO _x , other metal oxides, lithium metals, lithium-based metals such as lithium alloys. ; Metal compounds such as TiS ₂ and LiTiS ₂ are exemplified.

When used for producing a positive electrode for a non-aqueous electrolyte battery, examples of the positive electrode active material include lithium iron phosphate (LiFePO ₄ ), lithium manganese phosphate (LiMnPO ₄ ), and lithium cobalt phosphate (LiCoPO ₄ ). , Iron pyrophosphate (Li ₂ FeP ₂ O ₇ ), Lithium cobaltate composite oxide (LiCoO ₂ ), Spinel-type lithium manganate composite oxide (LiMn ₂ O ₄ ), Lithium manganate composite oxide (LiMnO ₂ ), lithium nickel composite oxide (LiNiO _2), lithium niobate composite oxide (LiNbO _2), ferrate lithium composite oxide (LiFeO _2), lithium magnesium acid complex oxide (LiMgO _2), lithium calcium acid complex oxide (LiCaO _2), cuprate lithium composite oxide (LiCuO _2), lithium composite oxide zincate (LiZnO _2), lithium molybdate complex oxide (LiMoO _2), lithium tantalate complex oxide (LiTaO _2), tungsten Lithium acid acid composite oxide (LiWO ₂ ), lithium-nickel-cobalt-aluminum composite oxide (LiNi _0.8 Co _0.15 Al _0.05 O ₂ ), lithium-nickel-cobalt-manganese composite oxide (LiNi _{0) .33} Co _0.33 Mn _0.33 O ₂ ), Li excess nickel-cobalt-manganese composite oxide (LixNiACoBMnCO ₂ solid solution), manganese nickel oxide (LiNi _0.5 Mn _1.5 O ₄ ), manganese oxide (LiNi _0.5 Mn _1.5 O ₄ ) MnO ₂ ), vanadium oxides, sulfur oxides, silicate oxides and the like are exemplified.

In the present invention, the slurry composition may further contain a thickener, if necessary. The thickener is not particularly limited, and a thickener known in the art can be used, for example, various alcohols, unsaturated carboxylic acids and modified products thereof, α-olefin-maleic acids and the like. Examples thereof include modified products, celluloses, polysaccharides such as starch, and the like.

When the slurry composition of the present invention contains a thickener, the content thereof is preferably 0.1 to 4% by mass when the total mass of the active material contained in the slurry composition is 100. , More preferably 0.3 to 3% by mass, still more preferably 0.5 to 2% by mass. When the content of the thickener is within the above range, it is possible to impart an appropriate viscosity to the slurry composition, and it is easy to control the layer thickness when applied to the current collector to a desired range. It is possible to suppress a decrease in discharge capacity.

In addition, the slurry composition may further contain a conductive auxiliary agent, if necessary. Examples of the conductive auxiliary agent include metal powder, conductive polymer, acetylene black and the like. When the slurry composition contains a conductive auxiliary agent, the content thereof is usually preferably 0.1 to 10% by mass, and more preferably, when the total mass of the active material contained in the slurry composition is 100. It is preferably 0.8 to 7% by mass.

Since the binder of the present invention can realize low resistance when used for an electrode of a non-aqueous electrolyte battery, it is suitable as a constituent material of an electrode for a non-aqueous electrolyte battery. Therefore, the present invention also covers electrodes for non-aqueous electrolyte batteries comprising a current collector having a layer comprising the binder and active material of the present invention. The electrode for a non-aqueous electrolyte battery of the present invention is obtained by, for example, applying the slurry composition containing the binder, the active material and water of the present invention to a current collector, and then removing a solvent such as water by a method such as drying. It can be produced by fixing a layer (hereinafter, also referred to as “mixed layer”) containing the binder and the active material of the present invention to a current collector.

The current collector constituting the electrode for the non-aqueous electrolyte battery of the present invention is not particularly limited as long as it is made of a conductive material, and for example, iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, and gold. , Platinum and other metal materials can be used. These may be used alone, or two or more kinds may be used in combination at an arbitrary ratio.

Copper is preferably used as the current collector for the negative electrode because the effect of the slurry for the negative electrode of the non-aqueous electrolyte battery of the present invention is most apparent. This is because the binder of the present invention has a high affinity with the copper foil, and a negative electrode having high adhesiveness can be produced. The shape of the current collector for the negative electrode is not particularly limited, but it is usually preferably in the form of a sheet having a thickness of about 0.001 to 0.5 mm.

Further, since the effect of the slurry for the negative electrode of the non-aqueous electrolyte battery of the present invention is most exhibited, it is preferable to use aluminum as the current collector for the positive electrode. This is because the binder of the present invention has a high affinity with the aluminum foil, and a positive electrode having high adhesiveness can be produced. The shape of the current collector for the positive electrode is not particularly limited, but it is usually preferably in the form of a sheet having a thickness of about 0.001 to 0.5 mm.

The method of applying the slurry composition to the current collector is not particularly limited, and examples thereof include a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a dipping method, and a brush coating method. The method can be used. The coating amount is also not particularly limited, but the thickness of the mixed layer containing the binder and the active material formed after removing the solvent or the dispersion medium by a method such as drying is preferably 0.005 to 5 mm, more preferably 0.01. The amount should be ~ 2 mm.

The drying method for removing the solvent such as water contained in the slurry composition is not particularly limited, and for example, aeration drying with warm air, hot air, and low humidity air; vacuum drying; irradiation ray drying with infrared rays, far infrared rays, electron beams, etc. And so on. The drying conditions should be adjusted so that the solvent can be removed as soon as possible while the speed range is such that the mixed layer does not crack due to the concentration of stress and the mixed layer does not peel off from the current collector. preferable. Further, it is also effective to press the current collector after drying in order to increase the density of the active material of the electrode. Examples of the pressing method include a die press and a roll press.

Furthermore, the present invention also includes a non-aqueous electrolyte battery having the above electrodes. Non-aqueous electrolyte batteries typically include a negative electrode, a positive electrode and an electrolyte. Examples of the non-aqueous electrolyte battery of the present invention include a lithium ion battery, a sodium ion battery, a lithium sulfur battery, an all-solid-state battery and the like.

When the binder of the present invention is used for the positive electrode, a negative electrode usually used for a non-aqueous electrolyte battery such as a lithium ion secondary battery can be used as the negative electrode without particular limitation. For example, examples of the negative electrode active material include graphite, hard carbon, and Si-based oxides. Further, the negative electrode active material, the above-mentioned conductive auxiliary agent, and a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinylidene fluoride have a boiling point of 100 ° C. or higher in water or the above-mentioned normal pressure. A negative electrode slurry prepared by mixing with a solvent of 300 ° C. or lower can be applied to a negative electrode current collector such as a copper foil, and then the solvent can be removed by drying or the like to obtain a negative electrode.

When the binder of the present invention is used for the negative electrode, a positive electrode usually used for a non-aqueous electrolyte battery such as a lithium ion secondary battery can be used as the positive electrode without particular limitation. For example, as the positive electrode active material, TiS ₂ , TiS ₃ , amorphous MoS ₃ , Cu ₂ V ₂ O ₃ , amorphous V ₂ O-P ₂ O ₅ , MoO ₃ , V ₂ O ₅ , V ₆ O Examples thereof include transition metal oxides such as ₁₃ and lithium-containing composite metal oxides such as LiCoO ₂ , LiNiO ₂ , LiMnO ₂ and LiMn ₂ O ₄ . Further, the positive electrode active material, the above-mentioned conductive auxiliary agent, and a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinylidene fluoride are mixed with water or the above-mentioned boiling point of 100 ° C. or higher and 300 ° C. or lower. The positive electrode slurry prepared by mixing with the solvent of the above can be applied to a positive electrode current collector such as aluminum, and then the solvent can be removed by drying or the like to obtain a positive electrode.

Further, both the positive electrode and the negative electrode may be electrodes containing the binder of the present invention.

Further, in the non-aqueous electrolyte battery of the present invention, an electrolytic solution in which an electrolyte is dissolved in a solvent can be used. The electrolyte may be liquid or gel as long as it is used for non-aqueous electrolyte batteries such as ordinary lithium ion secondary batteries, and exhibits a function as a battery depending on the type of negative electrode active material and positive electrode active material. You can select what you want to do. Specific electrolytes, for example, any known lithium salt can be used, for example _{LiClO 4, LiBF 6, LiPF 6} , LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiB 10 Cl 10 _{, LiAlC l4, LiCl, LiBr,} LiB (C 2 H 5) 4, CF 3 SO 3 Li, CH 3 SO 3 Li, LiCF 3 SO 3, LiC 4 F 9 SO 3, Li (CF 3 SO 2) 2 N , Lower aliphatic lithium carboxylate and the like.

The solvent for dissolving such an electrolyte (electrolyte solution solvent) is not particularly limited. Specific examples include carbonates such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate and diethyl carbonate; lactones such as γ-butyl lactone; trimethoxymethane, 1,2-dimethoxyethane, diethyl ether and 2-ethoxyethane. , Ethers such as tetrahydrofuran, 2-methyltetraxide; sulfoxides such as dimethylsulfoxide; oxolanes such as 1,3-dioxolane, 4-methyl-1,3-dioxolane; nitrogen-containing compounds such as acetonitrile and nitromethane; formic acid Organic acid esters such as methyl, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate; inorganic acid esters such as triethyl phosphate, dimethyl carbonate, diethyl carbonate; diglimes; triglimes; sulfolanes; Oxazolidinones such as 3-methyl-2-oxazolidinone; sulton compounds such as 1,3-propane sulton, 1,4-butane sulton, and nafta sulton can be mentioned, and these can be used alone or in combination of two or more. When a gel-like electrolytic solution is used, a nitrile-based polymer, an acrylic-based polymer, a fluorine-based polymer, an alkylene oxide-based polymer, or the like can be added as a gelling agent.

The method for producing the non-aqueous electrolyte battery of the present invention is not particularly limited, and examples thereof include the following production methods. That is, the negative electrode and the positive electrode are overlapped with each other via a separator such as a polypropylene porous membrane, wound or folded according to the shape of the battery, put into a battery container, and an electrolytic solution is injected to seal the battery. The shape of the battery may be any of known coin type, button type, sheet type, cylindrical type, square type, flat type and the like.

The non-aqueous electrolyte battery of the present invention is a battery that has both adhesiveness and improved battery characteristics, and is useful in various applications. For example, it is very useful as a battery used in a mobile terminal that is required to be smaller, thinner, lighter, and higher in performance.

Examples of the present invention will be described below, but the present invention is not limited thereto.

(Example 1)
<Synthesis of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer>
100 g of commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., 28-98s) was irradiated with an electron beam (30 kGy). Next, 33.4 g of acrylic acid and 466.6 g of methanol were charged into a reactor equipped with a stirrer, a reflux condenser, a nitrogen introduction tube and a particle addition port, and the inside of the system was replaced with nitrogen for 30 minutes while bubbling nitrogen. .. 100 g of polyvinyl alcohol irradiated with an electron beam was added thereto, and the particles were stirred and heated under reflux for 300 minutes in a state where the particles were dispersed in the solution to carry out graft polymerization. Then, the particles were separated by filtration, and the particles were vacuum-dried at 40 ° C. overnight to obtain the desired copolymer (number average molecular weight: 25100). The amount of ethylenically unsaturated carboxylic acid modification of the obtained copolymer was 7.3 mol%. The number average molecular weight and the modified amount of the copolymer were measured by gel permeation chromatography according to the following conditions.

<Measurement method of number average molecular weight of copolymer>
The measurement was performed according to the following conditions using a size exclusion high performance liquid chromatography device "GPC-101" manufactured by Showa Denko KK.
Measurement conditions Column: Two water-based columns "TSKgel GMPWXL" manufactured by Tosoh Corporation are connected in series. Standard sample: Polyethylene oxide and polyethylene glycol Solvent and mobile phase: 0.1 mol / L sodium nitrate aqueous solution Flow rate: 0.7 L / min, temperature : 25 ° C
Detector: RI

<Method for measuring the amount of ethylenically unsaturated carboxylic acid modification of the copolymer>
The 40 ° C. vacuum drying was carried out 12 hours a sample was dissolved in D _{2 O,} 3- (trimethylsilyl) -1-propane was used sodium sulfonate in a small amount added sample was prepared measurement. ^{1 1} H-NMR measurement was carried out at 25 ° C. using ¹ H-NMR (manufactured by JEOL Ltd .; LAMBDA 500). The peak derived from methine of vinyl alcohol unit is attributed to 3.8 to 4.2 ppm (integral value A), and the peak derived from the root of carboxylic acid (CH-COOH) is attributed to 2.0 to 2.5 ppm (integral value B). , The amount of modification was calculated by the following formula.
Denatured amount (mol%) = (B / A) x 100

<Preparation of neutralized salt of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer>
To 100 g of the vinyl alcohol and acrylic acid copolymer 10% by mass aqueous solution obtained above, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the copolymer, and the mixture was heated and stirred at 80 ° C. for 2 hours, and then stirred. , Cooled to room temperature. Then, 0.1 equivalent of magnesium acetate was added to the carboxylic acid unit, and the mixture was heated and stirred at 90 ° C. for 1 hour while distilling off acetic acid, and cooled to room temperature to obtain a binder aqueous solution. ^{1 From} the proton shift of the root of the carboxylic acid in H-NMR, the total equivalent ratio of magnesium and lithium to the carboxylic acid unit in the copolymer was calculated as the degree of neutralization and was 0.7.

<Calculation method of neutralization degree>
The 80 ° C. hot air drying was carried out for 1 hour samples were dissolved in D _{2 O,} 3- (trimethylsilyl) -1-propane was used sodium sulfonate in a small amount added sample was prepared measurement. ^{1 1} H-NMR measurement was carried out at 25 ° C. using ¹ H-NMR (manufactured by JEOL Ltd .; LAMBDA 500). The peak derived from the root (CH-COOH) of the carboxylic acid is attributed to 2.0 to 2.5 ppm and shifts to a high magnetic field with chloride. Therefore, a calibration curve of the shift value with respect to the added amount is created, and this calibration curve is used. By using it, the degree of neutralization was calculated.

<Measurement of content of multivalent metal atoms and alkali metal atoms>
The contents of the polyvalent metal and the alkali metal (mass% of the solid content of the binder aqueous solution) in the obtained binder aqueous solution were measured according to the following methods, respectively. The results are shown in Table 1.
Using a trace element analyzer "iCAP6500" manufactured by Thermo Fisher Scientific, 0.01 g of a sample is weighed in an Erlenmeyer flask as a pretreatment, 1 ml of sulfuric acid and 5 ml of nitric acid are added, and after heat decomposition, nitric acid (about 10 ml) is added in the middle to completely decompose. , 50 ml female up (solvent: water) was carried out, and the measurement was carried out under the conditions of RF power 1150 W, pump flow rate 50 rpm, auxiliary gas flow rate 0.5 L / min, nebulizer gas flow rate 0.7 L / min, and clant gas flow rate 12 L / min.

<Preparation of slurry composition>
To prepare the slurry composition for electrodes, 96 parts by mass of artificial graphite (FSN-1, manufactured by Sugisugi, China) as an active material for negative electrodes, 3 parts by mass of a 10% by mass aqueous solution of the binder as a solid content, and conductivity. Super-P (manufactured by Timcal Co., Ltd.) as an auxiliary agent (conductivity imparting agent) is put into a container dedicated to 1 part by mass as a solid content, kneaded using a planetary stirrer (ARE-250, manufactured by Shinky Co., Ltd.), and electrode coated. A working slurry composition was prepared. The composition ratio of the active material and the binder in the slurry composition is graphite powder: conductive auxiliary agent: binder = 96: 1: 3 (mass ratio) as a solid content.

<Slurry composition stability (visual test)>
In order to confirm the stability of the obtained slurry composition, the state of particle sedimentation immediately after the preparation of the slurry composition was visually confirmed. As the evaluation criteria, the slurry in which sedimentation did not occur for 3 hours or more was evaluated as ⊚, the slurry in which sedimentation occurred in 3 hours to 30 minutes was evaluated as Δ, and the slurry in which sedimentation occurred within 30 minutes was evaluated as ×. The results are shown in Table 1.

<Slurry composition stability (settling rate)>
Further, the particle settling speed (nm / sec) of the obtained slurry composition was measured by using a dispersion stability analyzer "Lumiiser610" manufactured by Nippon Luft, and the prepared slurry was placed in a 2 mm cell manufactured by PC, and the rotation speed was 600 rpm and the temperature was 25. The sedimentation speed was calculated from the moving distance for a time of 20% transmittance by measuring at ° C. for 3 hours under the condition of Light Factor 4. The results are shown in Table 1.

<Manufacturing of negative electrode for batteries>
The obtained slurry composition is coated on a copper foil (CST8G, manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.) of a current collector using a bar coater (T101, manufactured by Matsuo Industry Co., Ltd.) and at 80 ° C. After primary drying in a hot air dryer for 30 minutes, rolling treatment was performed using a roll press (manufactured by Hosen Co., Ltd.). Next, after punching as a battery electrode (φ14 mm), a coin battery electrode (negative electrode) was produced by secondary drying under reduced pressure conditions at 140 ° C. for 3 hours.

<Preparation of electrodes for peel strength and toughness test>
The obtained slurry composition is coated on a copper foil (CST8G, manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.) of a current collector using a bar coater (T101, manufactured by Matsuo Industry Co., Ltd.) and at 80 ° C. After primary drying in a hot air dryer for 30 minutes, rolling treatment was performed using a roll press (manufactured by Hosen Co., Ltd.) to obtain an electrode (thickness: about 35 μm) for peel strength and toughness test.

<Measurement of electrode peel strength>
The strength when the peel strength test electrode was peeled from the copper foil as the collecting electrode was measured. The peel strength was measured by 180 ° using a 50 N load cell (manufactured by Imada Co., Ltd.). The slurry-coated surface of the battery coating electrode obtained above and the stainless steel plate are bonded together using double-sided tape (double-sided tape made by Nichiban), and 180 ° peel strength (peeling width 10 mm, peeling speed 100 mm / min) is measured. did. The results are shown in Table 1.

<Electrode toughness test>
For evaluation of electrode toughness, use JIS K5600-5-1 (General paint test method-Part 5: Mechanical properties of coating film-Section 1: Flexibility (cylindrical mandrel method)) type 1 test equipment. It was done using. Visually check the electrode cracks, and prepare 1.5 mm, 1.0 mm, 0.8 mm, and 0.5 mm SUS rods (manufactured by SUS304Wire Niraco) for the electrodes that did not crack even with the maximum diameter of 2 mm in this test. Then, an electrode winding test was performed. The minimum SUS diameter without cracking is shown in Table 1 below.

<Battery production>
The negative electrode for the battery obtained above was transferred to a glove box (manufactured by Miwa Seisakusho Co., Ltd.) in an argon gas atmosphere. A metallic lithium foil (thickness 0.2 mm, φ16 mm) was used for the positive electrode. In addition, a polyprofylene system (Celguard # 2400, manufactured by Polypore Co., Ltd.) is used as a separator, and the electrolytic solution is ethylene carbonate (EC) and ethylmethyl carbonate (EMC) of lithium hexafluorophosphate (LiPF ₆ ) and vinylene. A coin cell (2032 type) was prepared by injecting using a mixed solvent system (1M-LiPF ₆ , EC / EMC = 3/7 vol%, VC 2% by weight) to which carbonate (VC) was added.

<Charging / discharging characteristic test>
A charge / discharge test was carried out on the produced coin battery using a commercially available charge / discharge tester (TOSCAT3100, manufactured by Toyo System Co., Ltd.). The coin battery is placed in a constant temperature bath at 25 ° C., and charged with a constant current of 0.1 C (about 0.5 mA / cm ² ) with respect to the amount of active material until it reaches 0 V with respect to the lithium potential, and further charged with the lithium potential. A constant voltage charge of 0 V was carried out up to a current of 0.02 mA. The capacity at this time was defined as the charging capacity (mAh / g). Next, a constant current discharge of 0.1 C (about 0.5 mA / cm ² ) was performed up to 1.5 V with respect to the lithium potential, and the capacity at this time was defined as the discharge capacity (mAh / g). The difference between the initial discharge capacity and the charge capacity was defined as the irreversible capacity, and the percentage of the discharge capacity / charge capacity was defined as the charge / discharge efficiency. The results are shown in Table 1.

(Example 2)
An aqueous binder solution was prepared in the same manner as in Example 1 except that the amounts of lithium hydroxide and magnesium acetate added were 0.3 equivalents with respect to the carboxylic acid unit.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 3)
An aqueous binder solution was prepared in the same manner as in Example 1 except that calcium acetate was added instead of magnesium acetate.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 4)
Lithium hydroxide was added to 100 g of a 10 wt% aqueous solution of the vinyl alcohol and acrylic acid copolymer prepared in Example 1 in an amount of 0.2 equivalent to the carboxylic acid unit in the polymer, sodium hydroxide in an amount of 0.3 equivalent, and magnesium acetate. An aqueous binder solution was prepared in the same manner as in Example 1 except that 0.1 equivalent was added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 5)
The target copolymer was synthesized in the same manner as in Example 1 except that 100 g of acrylic acid and 400 g of methanol were added. The amount of ethylenically unsaturated carboxylic acid modification of the obtained copolymer was 26.2 mol%. A neutralized salt was prepared using this copolymer in the same manner as in Example 1 to prepare an aqueous binder solution.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 6)
100 g of commercially available polyvinyl alcohol (Elvanol 71-30, manufactured by Kuraray Co., Ltd.) was irradiated with an electron beam (30 kGy). Next, 25 g of methacrylic acid and 475 g of methanol were charged into a reactor equipped with a stirrer, a reflux condenser, a nitrogen introduction tube and a particle addition port, and nitrogen was substituted in the system for 30 minutes while performing nitrogen bubbling. 100 g of polyvinyl alcohol irradiated with an electron beam was added thereto, and the particles were stirred and heated under reflux for 300 minutes in a state where the particles were dispersed in the solution to carry out graft polymerization. Then, the particles were separated by filtration, and the particles were collected and vacuum dried at 40 ° C. overnight to obtain the desired copolymer. The amount of ethylenically unsaturated carboxylic acid modification of the obtained copolymer was 7.0 mol%. A neutralized salt was prepared using this copolymer in the same manner as in Example 1 to prepare an aqueous binder solution.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 7)
The target copolymer was synthesized in the same manner as in Example 5 except that 100 g of methacrylic acid and 400 g of methanol were added. The amount of ethylenically unsaturated carboxylic acid modification of the obtained copolymer was 34.0 mol%. A neutralized salt was prepared using this copolymer in the same manner as in Example 1 to prepare an aqueous binder solution.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 8)
A reactor equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, and an initiator addition port is charged with 370 g of water and 100 g of commercially available polyvinyl alcohol (M115 manufactured by Kuraray Co., Ltd.) and heated at 95 ° C. under stirring. After dissolving polyvinyl alcohol, it was cooled to room temperature. Sulfuric acid of 0.5 eq (N) was added to the obtained aqueous solution to adjust the pH to 3.0. To this, 9.9 g of acrylic acid was added under stirring, and then the aqueous solution was heated to 70 ° C. while bubbling nitrogen, and then nitrogen was bubbled for 30 minutes at 70 ° C. to replace nitrogen. After nitrogen substitution, 80.7 g of an aqueous potassium persulfate solution (concentration 2.5% by mass) was added dropwise to the aqueous solution over 1.5 hours. After adding the whole amount, the temperature was raised to 75 ° C., the mixture was further stirred for 1 hour, and then cooled to room temperature. The obtained aqueous solution was poured onto a PET film and dried with hot air at 80 ° C. for 30 minutes to prepare a film. The film was frozen in liquid nitrogen, pulverized using a centrifugal pulverizer, and further vacuum dried at 40 ° C. overnight to obtain the desired copolymer. The amount of ethylenically unsaturated carboxylic acid modification of the obtained copolymer was 6.0 mol%. A neutralized salt was prepared using this copolymer in the same manner as in Example 1 to prepare an aqueous binder solution.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 9)
The target copolymer was synthesized in the same manner as in Example 8 except that 20 g of acrylic acid and 150 g of an aqueous potassium persulfate solution (concentration: 2.5% by mass) were added. The amount of ethylenically unsaturated carboxylic acid modification of the obtained copolymer was 12.0 mol%. A neutralized salt was prepared using this copolymer in the same manner as in Example 1 to prepare an aqueous binder solution.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 10)
In 100 g of a 10 wt% aqueous solution of the vinyl alcohol and acrylic acid copolymer prepared in Example 9, lithium hydroxide was 0.2 equivalent to the carboxylic acid unit in the copolymer, sodium hydroxide was 0.3 equivalent, and acetic acid. An aqueous binder solution was prepared in the same manner as in Example 9 except that 0.1 equivalent of magnesium was added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 11)
In 100 g of a 10 wt% aqueous solution of the vinyl alcohol and acrylic acid copolymer prepared in Example 9, lithium hydroxide was 0.1 equivalent to the carboxylic acid unit in the copolymer, sodium hydroxide was 0.2 equivalent, and acetic acid. An aqueous binder solution was prepared in the same manner as in Example 9 except that 0.3 equivalent of magnesium was added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 12)
An aqueous binder solution was prepared in the same manner as in Example 10 except that magnesium acetate was changed to calcium acetate.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 13)
A reactor equipped with a stirrer, a reflux condenser, an argon introduction tube, and an initiator addition port was charged with 640 g of vinyl acetate, 240.4 g of methanol, and 0.88 g of acrylic acid, and nitrogen was bubbled in the system for 30 minutes while bubbling nitrogen. Replaced. Separately from this, a methanol solution of acrylic acid (concentration: 20% by mass) was prepared as a solution for sequentially adding comonomer (hereinafter referred to as a delay solution), and argon was bubbled for 30 minutes. The temperature of the reactor was started, and when the internal temperature reached 60 ° C., 0.15 g of 2,2'-azobisisobutyronitrile was added to start polymerization. During the progress of the polymerization reaction, the prepared delay solution was dropped into the system so that the monomer composition (molar ratio of vinyl acetate and acrylic acid) in the polymerization solution became constant. After polymerizing at 60 ° C. for 210 minutes, the polymerization was stopped by cooling. Subsequently, the unreacted monomer was removed by occasionally adding methanol at 30 ° C. under reduced pressure to obtain a methanol solution of polyvinyl acetate modified with acrylic acid. Next, 20.4 g of sodium hydroxide methanol solution (concentration 18.0% by mass) was added to 400 g of the polyvinyl acetate methanol solution prepared by adding methanol to the methanol solution of the polyvinyl acetate to a concentration of 25% by mass. , 79.6 g of methanol was added, and saponification was carried out at 40 ° C. A gelled product was formed within a few minutes after the addition of the sodium hydroxide-methanol solution. This was pulverized with a pulverizer and left at 40 ° C. for 60 minutes to proceed with saponification. The obtained pulverized gel was repeatedly washed with methanol and then vacuum dried at 40 ° C. overnight to synthesize the desired copolymer. The amount of ethylenically unsaturated carboxylic acid modification of the obtained copolymer was 5.0 mol%. A neutralized salt was prepared using this copolymer in the same manner as in Example 1 to prepare an aqueous binder solution.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 14)
An aqueous binder solution was prepared in the same manner as in Example 9 except that 0.5 equivalent of magnesium acetate was added to the carboxylic acid unit in the copolymer.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 15)
An aqueous binder solution was prepared in the same manner as in Example 1 except that lithium hydroxide was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 16)
An aqueous binder solution was prepared in the same manner as in Example 2 except that lithium hydroxide was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Example 17)
The same method as in Example 1 was used except that 0.3 equivalent of calcium acetate was added to 100 g of a 10 wt% aqueous solution of the vinyl alcohol and acrylic acid copolymer prepared in Example 1 without adding lithium hydroxide. An aqueous binder solution was prepared.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 1)
An aqueous binder solution was prepared in the same manner as in Example 1 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 2)
An aqueous binder solution was prepared in the same manner as in Example 5 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 3)
An aqueous binder solution was prepared in the same manner as in Example 6 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 4)
An aqueous binder solution was prepared in the same manner as in Example 7 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 5)
An aqueous binder solution was prepared in the same manner as in Example 8 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 6)
An aqueous binder solution was prepared in the same manner as in Example 9 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 7)
An aqueous binder solution was prepared in the same manner as in Example 13 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was conducted. Further, an electrode for peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 8)
An aqueous binder solution was prepared in the same manner as in Example 10 except that magnesium acetate was not added.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 9)
A commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., 28-98s) was used to prepare a 10% by mass aqueous solution, which was used as a binder aqueous solution. From this aqueous solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

(Comparative Example 10)
A binder aqueous solution was prepared in the same manner as in Example 1 except that carboxymethyl cellulose (cellogen BSH-6, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added as a thickener without adding magnesium acetate in an amount of 5% by mass. went.
From the obtained aqueous binder solution, a slurry composition for a non-aqueous electrolyte battery was prepared by the same method as in Example 1, and the stability of the slurry composition was evaluated. Further, a negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge / discharge characteristic test was performed. Further, an electrode for a peel strength test was prepared by the same method as in Example 1, and the peel strength was measured. The results are shown in Table 1.

In Examples 1 to 17 using the binder of the present invention, it was clarified that a slurry having very excellent stability can be prepared. Further, by containing a polyvalent metal capable of forming a crosslinked form, the electric resistance is lowered and a high charge / discharge efficiency of 93% or more is realized. On the other hand, in Comparative Examples 1 to 8 containing no polyvalent metal salt, although high charge / discharge efficiency was shown, the slurry stability was not sufficient as compared with Examples. Further, in Comparative Example 10 in which the thickener was thickened using a thickener, the adhesiveness, slurry stability, and charge / discharge efficiency were all lowered, and these physical properties and battery characteristics were improved only by a simple thickening effect. It was shown that it could not be done. Further, when the total equivalent ratio of the polyvalent metal atom and the alkali metal atom to the carboxylic acid unit in the copolymer is 1 or less, high adhesiveness can be ensured in addition to slurry stability and low resistance. Was confirmed.

<Tensile elongation test>
The binder aqueous solutions (solid content 10% by mass) prepared in Examples 1 and 8 and Comparative Example 1 were placed on a Teflon substrate (film thickness 0.1 mm, manufactured by Esco) placed on a horizontal table, respectively. The coating was performed using a bar coater (T101, manufactured by Matsuo Industry Co., Ltd.) so that the film thickness at the time of drying was 30 μm. Then, after air-drying at room temperature for 1 day, the Teflon base material was peeled off to obtain a coating film (film) for tensile elongation test. The obtained film was left to stand in an environment of 25 ° C. and a relative humidity of 45% for 2 days, and then the tensile elongation of the film was measured under the following measurement conditions. The results are shown in Table 2.

Tensile elongation measurement conditions Measuring device: Autograph AG5000B, manufactured by Shimadzu Corporation Temperature: 25 ° C
Humidity: 45% RH
Distance between chucks: 70 mm
Test speed: 50 mm / min Test piece: Dumbbell type (test part width 10 mm, JIS K 7162-1B test piece)
Film thickness: 30 μm

The coating film obtained from the binder aqueous solution of Example 1 in which the vinyl alcohol and the ethylenically unsaturated carboxylic acid copolymer are graft copolymers showed high tensile elongation, and when a block copolymer was used (Example 8). ), It was confirmed that the flexibility can be improved while maintaining high adhesiveness. On the other hand, when the polyvalent metal salt was not contained (Comparative Example 1), no improvement in flexibility was confirmed even if the vinyl alcohol and the ethylenically unsaturated carboxylic acid copolymer were graft copolymers.

Claims (10)

It contains a neutralizing salt of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid, and the neutralizing salt is a neutralizing salt of the copolymer and a basic substance containing a polyvalent metal. Binder for water electrolyte batteries. The binder for a non-aqueous electrolyte battery according to claim 1, wherein the neutralizing salt is a neutralizing salt of the copolymer and a basic substance containing a polyvalent metal and a basic substance containing an alkali metal. The binder for a non-aqueous electrolyte battery according to claim 1 or 2, wherein the polyvalent metal is a divalent metal. The content of polyvalent metal atoms in the binder for non-aqueous electrolyte batteries is less than 0.5 equivalents with respect to the ethylenically unsaturated carboxylic acid unit in the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid. The binder for a non-aqueous electrolyte battery according to any one of claims 1 to 3. The total equivalent ratio of polyvalent metal atoms and alkali metal atoms to the ethylenically unsaturated carboxylic acid unit in the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid in the binder for a non-aqueous electrolyte battery is 1 or less. The binder for a non-aqueous electrolyte battery according to any one of claims 1 to 4. The binder for a non-aqueous electrolyte battery according to any one of claims 1 to 5, wherein the copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid is a graft copolymer. An aqueous binder solution for a non-aqueous electrolyte battery comprising the binder for a non-aqueous electrolyte battery according to any one of claims 1 to 6 and water. A slurry composition for a non-aqueous electrolyte battery, which comprises the binder for a non-aqueous electrolyte battery according to any one of claims 1 to 6, an active material and water. An electrode for a non-aqueous electrolyte battery comprising a current collector comprising the binder for the non-aqueous electrolyte battery according to any one of claims 1 to 6 and a layer containing an active material. A non-aqueous electrolyte battery having the electrode for the non-aqueous electrolyte battery according to claim 9.