TW201622218A - Binder for forming nonaqueous battery electrode, binder composition, electrode mixture slurry using same, electrode structure and nonaqueous battery - Google Patents

Abstract

Provided is a binder for forming a nonaqueous battery electrode, which has heat resistance, solvent resistance and good adhesion to a powder electrode material and a collector, and which could contribute to improvement of the battery characteristics. This binder for forming a nonaqueous battery electrode is easily used industrially. This binder for forming a nonaqueous battery electrode contains an aromatic polyamide resin and has a total halogen content of 100 ppm or less.

Description

Non-aqueous battery electrode forming forming material, bonding material composition, electrode mixture slurry using the same, electrode structure, and non-aqueous battery

The present invention relates to a non-aqueous battery, particularly a lithium ion battery, for stably fixing a powder electrode material (mainly an electrode active material and a conductive auxiliary agent added as needed) to an electrode, and can also help A binder (also referred to as a binder) composed of a reactive aromatic polyamide resin composition, a binder composition thereof, a solution of a binder composition, and a powder electrode material, which are improved in battery characteristics. The electrode mixture slurry composed of the mixture is further related to an electrode structure and a nonaqueous battery formed using the electrode mixture slurry.

As a binder of a powder electrode material such as an electrode active material of a non-aqueous battery, a vinylidene fluoride-based polymer is often used (Patent Documents 1 and 2). However, since the vinylidene fluoride-based polymer is relatively weak against the powder electrode material or the adhesion to the current-collecting substrate, the powder electrode material such as the active material may be peeled off or the powder electrode material may be contained during use. The phenomenon that the electrode mixture layer is peeled off from the current collecting substrate. Therefore, if a nonaqueous battery is used for a long period of time, there is a problem that the discharge capacity thereof decreases as time passes.

Examples of the polymer having high heat resistance include an example in which an aromatic polyimine is used as a binder (Patent Documents 3 to 5). However, if an aromatic polyimine is used, the following problems exist: Since the ring closure reaction is necessary, the processing steps become complicated and the productivity is lowered. Similarly to PVDF, the alkali resistance is not high, and the conductivity of Li ions is not high.

Further, in order to solve the above problems, various polymers have been studied as other bonding materials, and electrode sheets using aromatic polyamines have been proposed so far (Patent Documents 6 to 7). These methods show a method of producing an electrode sheet using a slurry containing meta-aramid and a solvent. Specific examples of the meta-polyarylamine include poly(m-xylylenediphenyl) m-phenylenediamine and a copolymer thereof, and the synthesis of the aromatic polyamine is a synthesis example using an acid chloride. The resulting binder contains a high concentration of impurity ions. The impurity ions have high mobility and are highly likely to affect the cycle characteristics of the battery. Further, as battery capacity is increasing, higher heat resistance or cycle characteristics are required for the binder resin in terms of ensuring safety.

Patent Document 1: Japanese Laid-Open Patent Publication No. 09-306502

Patent Document 2: Japanese Laid-Open Patent Publication No. 06-052861

Patent Document 3: Japanese Laid-Open Patent Publication No. 06-163031

Patent Document 4: Japanese Laid-Open Patent Publication No. 09-265990

Patent Document 5: Japanese Patent Laid-Open Publication No. 2004-079286

Patent Document 6: International Publication No. 2007/012517

Patent Document 7: Japanese Laid-Open Patent Publication No. 2012-142244

Therefore, the main object of the present invention is to provide an industrially easy-to-use non-aqueous system which has heat resistance, solvent resistance, and good adhesion to powder electrode materials and current collectors, and can also contribute to improvement of battery characteristics. A binder for forming a battery electrode.

A further object of the present invention is to provide an electrode mixture slurry comprising a solution of the composition of the above-mentioned binder, a mixture of a solution of a binder composition and a powder electrode material, and using the electrode mixture slurry The electrode structure and the non-aqueous battery are formed.

In order to solve the above problems, the present inventors have conducted intensive studies and found that it is extremely effective to use a binder containing a polymer having a specific structure for the purpose of the present application.

In other words, the present invention relates to a method of forming a non-aqueous battery electrode forming material comprising an aromatic polyamine resin having a total halogen amount of 100 ppm or less, and (2) a non-aqueous system as described in (1). The base material for forming a battery electrode, wherein the total amount of the acidic impurities is 1000 ppm or less; (3) The non-aqueous battery electrode forming structure according to (1) or (2), wherein the aromatic polyamide resin Has the following formula (1) in the structure

(wherein m and n are average values, and are positive numbers satisfying the relationship of 0≦n/(m+n)<0.5 and 0<m+n≦200; Ar ₁ represents a divalent aromatic group, and Ar ₂ represents The non-aqueous battery electrode according to any one of (1) to (3), wherein the divalent aromatic group having a phenolic hydroxyl group and Ar ₃ is a divalent aromatic group; An agglomerate in which an aromatic polyamide resin is contained by using a butadiene-acrylonitrile rubber, a butadiene rubber, a hydrogenated butadiene rubber, and a polyoxyxene rubber having a carboxyl group or an amine group selected from a terminal group. (A) A non-aqueous battery electrode forming binder composition, which is described in any one of (1) to (4), wherein the one or more types of the aromatic polyamine resin are modified by the rubber; (6) An electrode mixture slurry obtained by mixing (5) a solution and a powder of a binder composition for forming a nonaqueous battery electrode according to the invention. (7) An electrode structure having electrode mixture formed by using the electrode mixture slurry of (6) on at least one surface of the current collector Layer; (8) A non-aqueous battery, in which the positive electrode and the negative electrode is constituted by one (7) of the electrode structure according to at least.

The bonding agent of the present invention can be directly used in a usual production line, and the composition has heat resistance of 200 ° C or more, and is excellent in adhesion, solvent resistance, and contains as little impurity ion species as possible to hinder movement of lithium ions. Suitable for non-aqueous battery electrode forming applications.

Hereinafter, embodiments of the present invention will be described.

The knot of the present invention contains an aromatic polyamide resin and has a total halogen content of 100 ppm or less.

The aromatic polyamine resin may, for example, be a repeating unit represented by the above formula (1) in the structure.

Ar ₁ in the formula (1) represents a divalent aromatic group, Ar ₂ represents a divalent aromatic group having a phenolic hydroxyl group, and Ar ₃ represents a divalent aromatic group. Further, in the present invention, the "divalent aromatic group" means a structure obtained by removing two hydrogen atoms from an aromatic ring of a compound having at least one aromatic group in its structure, for example, from diphenyl ether. The structure in which each of the benzene rings on both sides of the phenyl ring is removed by a hydrogen atom is also included in the "divalent aromatic group" described in the present invention.

Specific examples of Ar ₁ in the formula (1) include residues obtained by removing two carboxyl groups from the following dicarboxylic acids: phthalic acid, isophthalic acid, terephthalic acid, 4, 4'-oxygen Dibenzoic acid, 4,4'-biphenyldicarboxylic acid, 3,3'-methylenedibenzoic acid, 4,4'-methylenedibenzoic acid, 4,4'-thiodibenzoic acid, 3,3'-carbonyldibenzoic acid, 4,4'-carbonyldibenzoic acid, 4,4'-sulfonyldibenzoic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2, 6-naphthalenedicarboxylic acid and 1,2-naphthalene dicarboxylic acid and the like are preferably residues of isophthalic acid.

Specific examples of Ar ₂ in the formula (1) include residues obtained by removing two carboxyl groups from a dicarboxylic acid having a phenolic hydroxyl group: 5-hydroxyisophthalic acid, 4-hydroxyisophthalic acid, 2-hydroxyisophthalic acid, 3-hydroxyisophthalic acid, 2-hydroxyterephthalic acid or the like is preferably a residue of 5-hydroxyisophthalic acid.

Specific examples of Ar ₃ in the formula (1) include residues in which two amine groups are removed from the following diamines: phenylenediamines such as m-phenylenediamine, p-phenylenediamine, and m-toluenediamine; 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether and 4,4'- Diaminodiphenyl ethers such as diaminodiphenyl sulfide; 3,3'-dimethyl-4,4'-diaminodiphenyl sulfide, 3,3'-diethoxy-4, Diamines such as 4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, and 3,3'-dimethoxy-4,4'-diaminodiphenyl sulfide Diphenyl sulfides; 4,4'-diaminobenzophenones and diaminobenzophenones such as 3,3'-dimethyl-4,4'-diaminobenzophenone; Diaminodiphenylphosphonium such as 4,4'-diaminodiphenylarylene and 4,4'-diaminodiphenylphosphonium; benzidine, 3,3'-dimethylbenzidine, 2,2'-Dimethylbenzidine, 3,3'-dimethoxybenzidine and benzidine such as 2,2'-dimethoxybenzidine;3,3'-diaminobiphenyl; Xylylenediamine such as p-xylylenediamine, m-xylylenediamine and o-xylylenediamine, and diaminodiphenylmethane such as 4,4'-diaminodiphenylmethane Preferably, it is a residue of a phenylenediamine, a diaminodiphenylmethane or a diaminodiphenyl ether, more preferably a diaminodiphenylmethane or a diaminodiphenyl ether. The residue of 3,4'-diaminodiphenyl ether or 4,4'-diaminodiphenyl ether is particularly preferred in terms of solvent solubility or flame retardancy of the obtained polymer. .

m and n in the formula (1) represent the average number of repetitions satisfying the relationship of 0≦n/(m+n)≦1.0 and 0<m+n≦500. Here, 0 ≦ n / (m + n) < 0.8 and 0 < m + n ≦ 300 are preferable, and 0 ≦ n / (m + n) ≦ 0.5 and 0 < m + n ≦ 200 are more preferable.

When the value of n/(m+n) in the formula (1) is 0.5 or less, the polarity in the binder does not become high, and the possibility that lithium ions are trapped becomes lower, which is preferable. In addition, when m+n is 200 or less, the solvent solubility is extremely lowered, and the productivity of the aromatic polyamide resin or the workability of the binder composition solution does not cause a problem.

The aromatic polyamine resin can be synthesized by the method described in JP-A-2006-124545, using the above dicarboxylic acid, a dicarboxylic acid having a phenolic hydroxyl group, and a diamine.

Further, the aromatic polyamine resin used in the present invention may also contain a rubber-modified aromatic Polyamide resin (also known as rubber modified aromatic polyamide resin). The rubber-modified aromatic polyamide resin can be synthesized by using a butadiene-acrylonitrile rubber, a butadiene rubber, a hydrogenated butadiene rubber, and a polyoxymethylene rubber having a carboxyl group or an amine group at the terminal. One or more of them are synthesized in accordance with the method described in JP-A-2007-161914.

In the target application, the non-aqueous battery electrode forming plug of the present invention preferably has a small content of ionic impurities. In particular, the acidic impurities contained in the binder component are also easily dissociated in the electrolyte, and the charge and discharge are repeated, and the lithium ions are bonded or associated with lithium ions, resulting in a decrease in capacity characteristics.

The acidic impurity of the present invention means an anion (or an anion-generating substance) which is paired with a lithium ion as a cation. For example, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, etc. are met regardless of the degree of dissociation.

In the examples, the quantification of acidic impurities was carried out by the total amount of chlorine and the amount of total phosphorus under fluorescent X-rays.

Therefore, the acidic impurities in the present invention refer to the total amount of chlorine and the total amount of phosphorus in the resin quantified by fluorescent X-rays.

The total amount of the acidic impurities is preferably 1000 ppm or less, more preferably 500 ppm or less, still more preferably 250 ppm or less, still more preferably 100 ppm or less, and most preferably 50 ppm or less.

In the non-aqueous battery electrode forming plug of the present invention, it is preferred to use a resin having the structure represented by the above formula (1) as a curing component. Alternatively, when it is used in the form of a composition with other hardening components, it is important that the resin having the structure represented by the formula (1) is also contained as a hardening component in a high ratio.

As another hardening component, a well-known hardening component (epoxy) which can be hard-hardened is mentioned. In the present invention, the curing component is preferably 3 parts by weight or less, more preferably 3 parts by weight or less, based on 100 parts by weight of the curable resin having the structure represented by the above formula (1). It is 1.5 parts by weight or less, and particularly preferably 0.5 parts by weight or less. By being in the above range, charging characteristics such as excellent capacity retention ratio can be exhibited.

The non-aqueous battery electrode forming binder composition of the present invention is obtained by dissolving the non-aqueous battery electrode forming binder of the present invention in various organic solvents. As the organic solvent which can be used for dissolution, for example, γ-butyrolactone, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethyl Amidoxime solvent such as acetamide, N,N-dimethylimidazolidone, anthraquinone such as tetramethylene hydrazine, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl An ether solvent such as ether, propylene glycol monomethyl ether monoacetate or propylene glycol monobutyl ether; a ketone solvent such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone or cyclohexanone; toluene, xylene, etc. Aromatic solvent. The concentration of the organic solvent in the binder composition for forming a nonaqueous battery electrode of the present invention is usually 30 to 95% by mass, preferably 40 to 90% by mass.

Further, in the non-aqueous battery electrode-forming binder of the present invention, in addition to the aromatic polyamide resin, other binders may be used in combination as needed. Examples of other binders include aromatic polymers such as polyimine, polyamidamine, semi-aromatic polyamide, and wholly aromatic polyamine; and polyvinylidene fluoride (PVDF). a fluoropolymer such as polytetrafluoroethylene (PTFE) or fluororubber or the like; styrene butadiene rubber (SBR), ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, a polymer having rubbery elasticity such as butadiene rubber, polybutadiene, polyethylene oxide or the like; a polyamine, polyvinyl chloride, polyvinylpyrrolidone, polyethylene, polypropylene, etc. a thermoplastic polymer or a denatured product thereof; an acrylic polymer such as acrylic acid, methacrylic acid, acrylate, methacrylate or the like; a starch, One type or two or more types of the polysaccharides such as polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, and diethyl fluorinated cellulose, or the like, or the like can be used.

The electrode mixture slurry is obtained by dispersing a mixed powder electrode material (electrode active material and, if necessary, a conductive auxiliary agent, other auxiliary agent) in the non-aqueous battery electrode forming forming material composition of the present invention obtained as described above. material.

The electrode mixture of the present invention can be applied to any of a positive electrode mixture and a negative electrode mixture of a nonaqueous battery.

As an active material of a lithium ion secondary battery, in the case of a positive electrode, LiMY ₂ (M is at least one of transition metals such as Co, Fe, Mn, Cr, and V; Y is sulfur such as O or S; The complex metal chalcogen compound represented by the group element compound is particularly preferably a composite metal oxide represented by LiNi _x Co _1-x O ₂ (0≦x≦1). In the case of a negative electrode, in addition to graphite, activated carbon, or a powdery carbonaceous material such as a phenol resin or an asphalt which is carbonized, examples thereof include metal oxide-based GeO, GeO ₂ , SnO, and SnO. ₂ , PbO, PbO ₂ , titanium nitrate, cerium oxide (SiO, SiO _x , 0 < x < 2), cerium, or such composite metal oxides.

The conductive auxiliary agent in the battery is used to increase the conductivity of the electrode mixture layer when an active material having a small electron conductivity such as LiCoO _{2 is} used, and a carbonaceous material such as carbon black, graphite fine powder or fiber, or Fine powder or fiber of metal such as nickel or aluminum. When a highly conductive substance is used as the active material, it is not necessary to use such a conductive auxiliary agent.

The electrode mixture slurry of the present invention is preferably formed by mixing 100 parts by mass of the powder electrode material with a solution containing the solid content of 0.1 to 20 parts by mass of the binder composition of the present invention.

The electrode mixture slurry formed as described above is applied to, for example, iron, stainless At least one side, preferably two sides of a current collecting substrate composed of a metal foil such as steel, steel, copper, aluminum, nickel, titanium or the like and having a thickness of 5 to 20 μm is dried at, for example, 50 to 400 ° C, for example, In the case of a small scale, an electrode mixture layer having a thickness of 10 to 1000 μm is formed, thereby forming an electrode for a nonaqueous battery.

The drying temperature is usually 50 to 400 ° C, more preferably 150 to 400 ° C, and still more preferably 250 to 400 ° C from the viewpoint of residual solvent.

The secondary battery has a structure in which a microporous material containing a polymer substance impregnated with an electrolytic solution and containing a polymer substance such as polypropylene or polyethylene is disposed between the positive electrode and the negative electrode in a bottomed metal case. The separator formed of the film is wound into a spiral power generating element.

As the nonaqueous electrolytic solution impregnated in the separator, for example, an electrolyte such as a lithium salt can be dissolved in a nonaqueous solvent (organic solvent).

Here, as the electrolyte, there are LiPF ₃ , LiAsF ₆ , LiClO ₄ , LiBF ₄ , LiCH ₃ SO ₃ , LiCF ₃ SO ₃ , LiN(CF ₃ OSO ₂ ) ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiC (CF). ₃ OSO ₂ ) ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiC(CF ₃ SO ₂ ) ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiC(CF ₃ SO ₂ ) ₃ and the like.

Further, as the organic solvent of the electrolyte, propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate, ethyl methyl carbonate, γ can be used. - butyrolactone, methyl propionate, ethyl propionate, mixtures of these, etc., but are not necessarily limited to these.

Example

Next, the present invention will be specifically described by way of examples, but the invention is not limited to the examples.

Synthesis Example 1 (synthesis of component (A))

The flask equipped with the thermometer, the cooling tube, the fractionation tube and the agitator was subjected to nitrogen purge while adding 3.6 parts of 5-hydroxyisophthalic acid, 162.7 parts of isophthalic acid, and 3,4'-diaminodiphenyl ether 204. 1 part of lithium chloride, 12.8 parts of lithium chloride, 1360 parts of N-methylpyrrolidone, 272 parts of pyridine, and stirred to dissolve 490 parts of triphenyl phosphite, and then carry out a condensation reaction at 95 ° C for 4 hours. The reaction liquid of the component (A) was obtained. While stirring, 1300 parts of water was added dropwise to the reaction liquid at 90 ° C for 3 hours, and the mixture was further stirred at 90 ° C for 1 hour, cooled to 60 ° C, and allowed to stand for 30 minutes. The layer separation is such that the upper layer is the water layer and the lower layer is the oil layer (resin layer), so the upper layer is removed by decantation. The amount of wastewater is 1200 parts. To the oil layer (resin layer), 1200 parts of N,N-dimethylformamide was added and diluted. Further, the water washing step of the water addition, the layer separation, the decantation, and the solvent addition was repeated seven times to carry out the washing of the component (A). The component (A) solution obtained above was sprayed to 6000 parts of the stirred water using a two-fluid nozzle, and the fine powder of the component (A) having a particle diameter of 5 to 50 μm precipitated was separated by filtration. The wet cake of the obtained precipitate was dispersed in 3200 parts of methanol and refluxed under stirring for 2 hours. Then, methanol was separated by filtration, and the precipitates collected by washing 3200 parts of water were washed and dried, whereby the following formula (2) was obtained in the structure.

332 parts of the component (A) of the repeating unit indicated. The amount of the element contained in the component (A) was quantified by a fluorescent X-ray measuring apparatus, and as a result, the total amount of phosphorus was 150 ppm. The total chlorine content is 20 ppm. Further, the intrinsic viscosity of the obtained component (A) was 0.52 dl/g (dimethylacetamide solution, 30 ° C), and the results were determined by gel permeation chromatography and determined by polystyrene conversion. The number average molecular weight was 44,000, and the weight average molecular weight was 106,000. The value of m in the formula (2) calculated from the molar ratio of each component used in the synthesis reaction was about 39.2, and the value of n was about 0.8.

As the component (A'), a commercially available KAYAFLEX BPAM (manufactured by Nippon Kayaku Co., Ltd.) obtained by reacting a butadiene rubber whose terminal carboxyl group is modified with the above formula (2) is used.

Synthesis Example 2 (synthesis of component (B))

The flask equipped with a thermometer, a cooling tube, a fractionation tube, and a stirrer was flushed with nitrogen while adding 169.3 parts of isophthalic acid, 204 parts of 3,4'-diaminodiphenyl ether, 12.8 parts of lithium chloride, and N- After 1360 parts of methylpyrrolidone and 272 parts of pyridine were stirred and dissolved, 490 parts of triphenyl phosphite was added and a condensation reaction was carried out at 95 ° C for 4 hours to obtain a reaction liquid of the component (B). While stirring, 1300 parts of water was added dropwise to the reaction liquid at 90 ° C for 3 hours, and the mixture was further stirred at 90 ° C for 1 hour, cooled to 60 ° C, and allowed to stand for 30 minutes. The layer separation is such that the upper layer is the water layer and the lower layer is the oil layer (resin layer), so the upper layer is removed by decantation. The amount of wastewater is 1200 parts. To the oil layer (resin layer), 1200 parts of N,N-dimethylformamide was added and diluted. Further, the water washing step of the water addition, the layer separation, the decantation, and the solvent addition was repeated seven times to carry out the cleaning of the component (B). The component (B) solution obtained above was sprayed to 6000 parts of the stirred water using a two-fluid nozzle, and the fine powder of the component (B) having a particle diameter of 5 to 50 μm precipitated was separated by filtration. The wet cake of the obtained precipitate was dispersed in 3200 parts of methanol and refluxed under stirring for 2 hours. Then, methanol was separated by filtration, and the precipitates collected by washing 3200 parts of water were washed and dried, whereby the following formula (3) was obtained in the structure.

332 parts of the component (B) of the repeating unit indicated. The amount of the element contained in the component (B) was quantified by a fluorescent X-ray measuring apparatus, and as a result, the total phosphorus amount was 150 ppm, and the total chlorine amount was 20 ppm. Further, the intrinsic viscosity of the obtained component (B) was 0.50 dl/g (dimethylacetamide solution, 30 ° C), and the results were determined by gel permeation chromatography and determined by polystyrene conversion. The number average molecular weight was 35,000 and the weight average molecular weight was 96,000.

Synthesis Example 3 <Dicarboxylic acid III Synthesis of active esters >

To a flask equipped with a thermometer, a nitrogen introduction tube, and a stirrer, 4.2 parts of isophthalic acid, 2-chloro-4,6-dimethoxy-1,3,5-three was added. 9.7 parts of N-methyl-2-pyrrolidone 100 parts and cooled to 0 °C. Thereafter, 7.6 parts of N-methylofofolin was added dropwise with stirring, and the reaction was carried out for 15 minutes to obtain the following formula (4).

Dicarboxylic acid three The reaction solution of the active ester. The reaction solution was poured into 1000 parts of ion-exchanged water, and the precipitated product was separated by filtration, recrystallized from a mixed solvent of ethyl acetate and n-hexane, and dried to obtain a dicarboxylic acid White powdery crystalline powder 1 of the active ester (yield 23%).

Synthesis Example 3' (synthesis of component (C))

The flask equipped with the thermometer, the nitrogen introduction tube, and the agitator was subjected to nitrogen purge, and 20 parts of 3,4'-diaminodiphenyl ether and 200 parts of N-methylpyrrolidone were stirred and dissolved, and 44 parts of the above were added. Dicarboxylic acid III obtained The powder 1 of the active ester was reacted at 20 ° C for 6 hours to obtain a reaction liquid of a polyamide resin. The obtained reaction liquid was poured into 2000 parts of methanol, and the precipitated resin was separated by filtration, washed with 200 parts of methanol, and then refluxed with methanol to carry out purification. Then, the mixture was cooled to room temperature, filtered, and the filtrate was dried to obtain 32 parts of the component (C) having the repeating unit represented by the above formula (3) in the structure. The amount of the element contained in the component (C) was quantified by a fluorescent X-ray measuring apparatus. As a result, the total phosphorus amount was below the detection limit, and the total chlorine amount was 2 ppm. Further, the intrinsic viscosity of the obtained component (C) was 0.45 dl/g (dimethylacetamide solution, 30 ° C), and the results were determined by gel permeation chromatography and determined by polystyrene conversion. The number average molecular weight was 41,000 and the weight average molecular weight was 69,000.

Synthesis Example 4 (synthesis of component (D))

The flask equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer was subjected to nitrogen purge, and 22 parts of 3,3'-dihydroxy-4,4'-diaminobiphenyl and 205 parts of N-methylpyrrolidone were subjected. Stirring and stirring, adding 44 parts of the dicarboxylic acid obtained above Powder 1 of active ester, reacted at 20 ° C for 12 hours to obtain polybenzoic acid A reaction solution of an azole precursor resin. The obtained reaction liquid was poured into 2000 parts of methanol, and the precipitated resin was separated by filtration, washed with 200 parts of methanol, and then refluxed with methanol to carry out purification. Then, after cooling to room temperature, filtration is carried out to dry the filtrate, whereby the following formula (5) is obtained in the structure.

The component (D) of the repeated unit represented is 32 parts. The amount of the element contained in the component (D) was quantified by a fluorescent X-ray measuring apparatus. As a result, the total phosphorus amount was below the detection limit, and the total chlorine amount was 1 ppm. Further, the intrinsic viscosity of the obtained component (D) was 0.85 dl/g (dimethylacetamide solution, 30 ° C), and the results were determined by gel permeation chromatography and determined by polystyrene conversion. The number average molecular weight was 19,000 and the weight average molecular weight was 35,000.

Synthesis Example 5 (synthesis of component (E))

The flask to which the thermometer, the cooling tube, the dropping funnel, and the stirrer were attached was subjected to nitrogen purge, and 66.1 parts of 3,4'-diaminodiphenyl ether and 600 parts of N-methylpyrrolidone were added and stirred. Soluble. A solution containing 66.3 parts of isophthalic acid chloride and 68 parts of N-methylpyrrolidone was added to the solution. The condensation reaction was carried out at a temperature of 30 ° C or lower for 4 hours, whereby a reaction liquid of the component (E) was obtained. While stirring, 274 parts of a 12.4 wt% sodium carbonate aqueous solution was added dropwise to the reaction liquid at a temperature of 30 ° C or lower for 3 hours, and further stirred at 30 ° C or lower for 1 hour, and then allowed to stand for 30 minutes. The layer separation is such that the upper layer is the water layer and the lower layer is the oil layer (resin layer), so the upper layer is removed by decantation. The amount of wastewater is 690 parts. To the oil layer (resin layer), 200 parts of N,N-dimethylformamide was added for dilution. The obtained component (E) solution was sprayed to 6000 parts of the stirred water using a two-fluid nozzle, and the precipitated fine powder of the component (E) having a particle diameter of 5 to 50 μm was separated by filtration. By filtering out the precipitates The mixture was dried to obtain 80 parts of the component (E) having a repeating unit represented by the above formula (3) in the structure. The amount of the element contained in the component (E) was quantified by a fluorescent X-ray measuring apparatus. As a result, the total phosphorus amount was below the detection limit, and the total chlorine amount was 120 ppm. Further, the intrinsic viscosity of the obtained component (E) was 0.49 dl/g (dimethylacetamide solution, 30 ° C), and the results were determined by gel permeation chromatography and determined by polystyrene conversion. The number average molecular weight was 27,000 and the weight average molecular weight was 93,000. .

Examples 1 to 5 and Comparative Example 1

Adding N-methylpyrrolidone 245 to 100 parts of each of the obtained component (A), component (A'), component (B), component (C), component (D), and component (E) In this way, a solution of a binder composition for forming a nonaqueous battery electrode of the present invention is obtained.

The obtained binder composition solution was applied to a PET film so as to have a thickness of 25 μm after drying, and the solvent was removed under drying conditions at 130 to 150 ° C and peeled off from the PET film, and then completely dried at 250 ° C. Dry the test piece. The glass transition temperature of the obtained test piece was measured by DMA (Dynamic Viscoelasticity Measuring Apparatus), and as a result, the system using the component (A) was 255 ° C, and the system using the component (A') was 200 ° C.

Each of the obtained binder composition solutions was used in an amount of 100 parts to prepare an electrode mixture for a negative electrode.

Carbotron P manufactured by Kureha Chemical Co., Ltd. is used as an active material for the negative electrode, and the binder composition is mixed so that the solid content of the binder resin is 10 parts by mass based on 100 parts by mass of the active material, respectively, to prepare an electrode mixture. Agent slurry. The electrode mixture slurry was applied onto a copper foil having a thickness of 10 μm and dried at 150 to 350 °C. The thickness of the electrode composite material layer formed on the copper foil is in the range of 100 to 120 μm.

Using this electrode structure, the peel strength of the copper foil from the electrode composite material layer was measured by a 180° peel test in accordance with JIS K6854. It exhibits a higher value equivalent to or higher than PVDF as a general binder.

Although the electrode structure was immersed in a solvent of propylene carbonate at 25 ° C for 144 hours, no abnormality in appearance was observed.

<Method for Producing Sample Battery for Evaluation>

The electrode structure produced by the above method was cut into a circular shape to serve as a negative electrode for a battery. A battery for evaluation was prepared using the negative electrode for each battery. A lithium metal plate was used as the positive electrode. Further, as the electrolytic solution, a 1 liter nonaqueous electrolytic solution was prepared by dissolving 1 mol of LiPF ₆ in a mixed solvent of 50% by volume of ethyl carbonate and 50% by volume of diethyl ether carbonate.

<Method and result of evaluation of sample battery>

Evaluation of sample batteries of Examples 1 to 5 and Comparative Example 1

A charge and discharge cycle test was performed on a sample battery using each of the components (A), (A'), (B), (C), (D), and (E) obtained by the above method, and the capacity was measured. Maintenance rate, expansion rate, etc.

In the charge and discharge cycle test, the amount of electric power until the end voltage is reached by charging or discharging is measured, and the value obtained by accumulating the electric quantities is taken as the actual measured charging capacity or the measured discharge capacity in the cycle. Further, the capacity retention rate is calculated based on the actually measured values of the capacities. Here, the "capacity retention rate" refers to the ratio of the maximum value of the actual measured charging capacity observed in the charge and discharge cycle test to the reference capacity, and the ratio of the discharge capacity in each cycle to the reference capacity.

Regarding the expansion ratio, the thickness before the test was measured in advance, and after the cycle test, the thickness was further measured, and the rate of change with respect to the initial thickness was defined as the expansion ratio.

Method for determining capacity retention rate

More than 80%...○

More than 50%~ not up to 80%...△

Less than 50%...×

Method for determining expansion ratio

Less than 50%...○

More than 50%~ not up to 70%...△

More than 70%...×

From the above results, it was confirmed that the non-aqueous battery electrode forming binder of the present invention maintains a high capacity retention ratio and a small expansion change.

The present invention has been described in detail with reference to the specific embodiments thereof, and it is understood that various changes and modifications may be made without departing from the spirit and scope of the invention.

Furthermore, the present application is based on a Japanese patent application filed on Jul. 24, 2014 (2014-150861), the entire contents of which is incorporated by reference. Again, all references cited herein are incorporated in their entirety.

Claims (8)

A non-aqueous battery electrode forming material comprising an aromatic polyamide resin and having a total halogen content of 100 ppm or less. The non-aqueous battery electrode-forming knot material according to the first aspect of the invention, wherein the total amount of the acidic impurities is 1000 ppm or less. The non-aqueous battery electrode forming structure according to claim 1 or 2, wherein the aromatic polyamide resin has the following formula (1) in the structure; (wherein m and n are average values, and are positive numbers satisfying the relationship of 0≦n/(m+n)<0.5 and 0<m+n≦200; Ar ₁ represents a divalent aromatic group, and Ar ₂ represents A repeating unit represented by a divalent aromatic group having a phenolic hydroxyl group and Ar ₃ representing a divalent aromatic group. The non-aqueous battery electrode forming structure according to any one of claims 1 to 3, wherein the aromatic polyamide resin comprises butadiene-propylene having a carboxyl group or an amine group selected from a terminal group. An aromatic polyamine resin which is modified by rubber in a reaction of at least one of a nitrile rubber, a butadiene rubber, a hydrogenated butadiene rubber, and a polyoxyxene rubber. A non-aqueous battery electrode-forming structure for forming a non-aqueous battery electrode according to any one of claims 1 to 4, which is obtained by dissolving a non-aqueous battery electrode forming material in an organic solvent. An electrode mixture slurry obtained by mixing a solution of a binder composition for forming a nonaqueous battery electrode of the fifth aspect of the patent application with a powder electrode material. An electrode structure which is attached to at least one side of a current collector and has a sixth application patent scope An electrode mixture layer formed by the electrode mixture slurry. A nonaqueous battery, wherein at least one of a positive electrode and a negative electrode is composed of an electrode structure of claim 7 of the patent application.