Electrode composite materials, secondary batteries, and all-solid-state batteries

Abstract

The purpose of the present invention is to provide an electrode mixture containing a dispersant with enhanced dispersibility of an electrode active material and / or a solid electrolyte. Specifically, an electrode mixture containing an electrode active material and / or a solid electrolyte and a dispersant, wherein the dispersant is a polyester represented by general formula (1-1) or (1-2) (where G is an aliphatic diol residue having 2 to 20 carbon atoms, A is an aliphatic dicarboxylic acid residue having 2 to 10 carbon atoms, X1 and X2 are each an aliphatic polybasic acid residue having 2 to 10 carbon atoms or an aromatic polybasic acid residue having 6 to 15 carbon atoms, Y is a monocarboxylic acid residue having 1 to 20 carbon atoms, Z is a monoalcohol residue having 2-30 carbon atoms, p is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or the aromatic polybasic acid residue of X1, q is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or the aromatic polybasic acid residue of X2, and n represents the number of repetitions).

Description

[Technical Field]

[0001] This invention relates to electrode composite materials, secondary batteries, and all-solid-state batteries. [Background technology]

[0002] In recent years, the introduction of electric vehicles has been rapidly progressing in various countries in order to achieve reductions in carbon dioxide emissions. High-energy-density lithium-ion batteries (LiBs) are being adopted as the power source, and the market for LiBs is expected to expand.

[0003] To extend the driving range of automobiles and further enhance user convenience, there is a demand for higher capacity and smaller size lithium-ion batteries (LiBs). LiBs typically consist of a laminated structure of a positive electrode sheet, a separator, and a negative electrode sheet. The positive electrode sheet and negative electrode sheet are sheets containing positive electrode active material and negative electrode active material, respectively, and battery performance can be improved by well-dispersing the active material within the sheets without uneven distribution.

[0004] All-solid-state batteries, which are being developed as next-generation batteries, typically have a stacked structure consisting of a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. Similar to lithium-ion batteries (LiBs), the electrode layer contains active material, and battery performance can be improved by well-dispersing the active material within the electrode layer without uneven distribution. Furthermore, since the electrolyte in all-solid-state batteries is solid, it is necessary to improve the dispersibility of the solid electrolyte in order to form a good ion path.

[0005] To improve the dispersibility of the active material and / or solid electrolyte, Patent Document 1 proposes the addition of an amine-based dispersant. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2023-546207 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The dispersant described in Patent Document 1 is a low-molecular-weight compound containing nitrogen, which may generate nitrogen gas and / or ammonia during use in a battery, potentially compromising the safety of the battery.

[0008] The problem that the present invention aims to solve is to provide an electrode mixture containing a dispersant that enhances the dispersibility of the electrode active material and / or solid electrolyte. Another problem that the present invention aims to solve is to provide an all-solid-state battery in which the dispersibility of the electrode active material and / or solid electrolyte in the battery components is improved. Another problem that the present invention aims to solve is to provide a secondary battery in which the dispersibility of electrode active material and / or solid electrolyte in the battery components is improved. [Means for solving the problem]

[0009] As a result of diligent research to solve the above problems, the inventors of the present invention have found that a specific polyester dispersant improves the dispersibility of electrode active materials and / or solid electrolytes, thereby improving battery performance, and have completed the present invention.

[0010] In other words, the present invention relates to the following electrode composite materials, etc. 1. An electrode mixture containing an electrode active material and / or a solid electrolyte and a dispersant, An electrode mixture in which the dispersant is a polyester represented by the following general formula (1-1) or (1-2). [ka] (In the above general formulas (1-1) and (1-2), G is an aliphatic diol residue with 2 to 20 carbon atoms. A is an aliphatic dicarboxylic acid residue with 2 to 10 carbon atoms. X 1 and X 2These are, independently, aliphatic polybasic acid residues having 2 to 10 carbon atoms or aromatic polybasic acid residues having 6 to 15 carbon atoms. Y is a monocarboxylic acid residue with 1 to 20 carbon atoms. Z is a monoalcohol residue with 2 to 30 carbon atoms. p is X 1 It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. q is X 2 It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. n represents the number of repetitions. 2. The electrode material according to 1, wherein the acid value of the polyester is in the range of 3 to 400 mg KOH / g. 3. The electrode composite material according to claim 1 or 2, wherein G is an aliphatic diol residue having a branched structure with 3 to 20 carbon atoms. 4. An electrode composite material according to any of 1 to 3, wherein A is an aliphatic dicarboxylic acid residue having 4 to 10 carbon atoms. 5.X 1 and X 2 However, each of the electrode composite materials is independently one of 1 to 4, which are aliphatic dicarboxylic acid residues having 2 to 10 carbon atoms. 6. The electrode composite material according to any one of 1 to 5, wherein the polyester is a polyester represented by the general formula (1-2) in which Z is an aliphatic monoalcohol residue having 2 to 30 carbon atoms. 7. An electrode composite material according to any one of 1 to 6, wherein the number average molecular weight of the polyester is in the range of 1,500 to 5,000. 8. The electrode mixture according to any one of 1 to 7, wherein the polyester is a liquid at room temperature. 9. An electrode composite material according to any one of 1 to 8, wherein the electrode active material is one or more positive electrode active materials selected from lithium manganate, lithium cobaltate, lithium nickel manganese cobaltate, lithium nickel cobalt aluminate, lithium nickel cobaltate, lithium-containing olivine-type phosphate, titanium sulfide, molybdenum sulfide, iron sulfide, copper sulfide, nickel sulfide, niobium selenide, lithium iron phosphate, lithium manganese phosphate, lithium iron manganese phosphate, lithium cobalt phosphate, and lithium nickel phosphate. 10. An electrode composite material according to any one of 1 to 9, wherein the electrode active material is one or more negative electrode active materials selected from lithium, indium, aluminum, silicon, tin, lithium oxide, indium oxide, aluminum oxide, silicon oxide, and tin oxide. 11. The electrode mixture according to any one of 1 to 10, wherein the solid electrolyte is an oxide solid electrolyte containing lithium and oxygen and / or a sulfide solid electrolyte containing lithium and sulfur. 12. An electrode mixture according to any one of 1 to 11, wherein the dispersant is contained in an amount of 0.05 to 10 parts by mass per 100 parts by mass of the total of the electrode active material and the solid electrolyte. A secondary battery using an electrode composite material described in any of sections 13.1 to 12. 14. An all-solid-state battery having a positive electrode layer, a solid electrolyte layer, and a negative electrode layer in this order, An all-solid-state battery containing a dispersant in which one or more of the positive electrode layer, the solid electrolyte layer, and the negative electrode layer is a polyester represented by the following general formula (1-1) or (1-2). [ka] (In the above general formulas (1-1) and (1-2), G is an aliphatic diol residue with 2 to 20 carbon atoms. A is an aliphatic dicarboxylic acid residue with 2 to 10 carbon atoms. X 1 and X 2 These are, independently, aliphatic polybasic acid residues having 2 to 10 carbon atoms or aromatic polybasic acid residues having 6 to 15 carbon atoms. Y is a monocarboxylic acid residue having 1 to 20 carbon atoms, Z is a monoalcohol residue having 2 to 30 carbon atoms, p is X 1 an integer obtained by subtracting 1 from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue of, q is X 2 an integer obtained by subtracting 1 from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue of, n represents the number of repetitions.) 15. A secondary battery having a positive electrode, a separator, and a negative electrode in this order, wherein the separator is a laminate in which the surface of the base material is coated with a coating layer containing inorganic particles, A secondary battery in which one or more of the positive electrode, the coating layer, and the negative electrode contain a dispersant that is a polyester represented by the following general formula (1-1) or (1-2).

Chemical formula

Advantages of the Invention

[0011] The present invention provides an electrode mixture containing a dispersant that enhances the dispersibility of the electrode active material and / or solid electrolyte. The present invention provides an all-solid-state battery in which the dispersibility of the electrode active material and / or solid electrolyte in the battery components is improved. The present invention provides a secondary battery in which the dispersibility of electrode active material and / or solid electrolyte in the battery components is improved. [Modes for carrying out the invention]

[0012] The following describes one embodiment of the present invention. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications without impairing the effects of the present invention. Furthermore, the compounds used in this specification may be derived from fossil resources or from biological resources.

[0013] [Electrode composite material] The electrode mixture of the present invention is an electrode mixture containing a solid electrolyte and / or an electrode active material and a dispersant, wherein the dispersant is a polyester having a specific structure. By including a dispersant in the electrode composite material, which is a polyester having a specific structure, the uneven distribution of the solid electrolyte and / or electrode active material within the battery components can be suppressed, thereby improving the performance of the resulting battery. The following describes each component.

[0014] (Dispersant) The dispersant in the electrode mixture of the present invention is a polyester represented by the following general formula (1-1) or (1-2). Hereinafter, the polyester that is the dispersant may be referred to as "the polyester of the present invention."

[0015] [ka] (In the above general formulas (1-1) and (1-2), G is an aliphatic diol residue with 2 to 20 carbon atoms. A is an aliphatic dicarboxylic acid residue with 2 to 10 carbon atoms. X 1 and X 2 These are, independently, aliphatic polybasic acid residues having 2 to 10 carbon atoms or aromatic polybasic acid residues having 6 to 15 carbon atoms. Y is a monocarboxylic acid residue with 1 to 20 carbon atoms. Z is a monoalcohol residue with 2 to 30 carbon atoms. p is X 1 It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. q is X 2 It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. n represents the number of repetitions.

[0016] The polyester of the present invention is thought to improve the dispersibility of the electrode active material and solid electrolyte by ensuring compatibility in the electrode mixture through a polyester chain containing a carboxyl group at one end that is adsorbed onto the solid electrolyte and / or electrode active material, and the other end that is sealed.

[0017] In this invention, "diol residue" and "alcohol residue" refer to the organic groups remaining after removing the hydroxyl group from a diol and an alcohol. In this invention, "carboxylic acid residue" refers to the remaining organic group after removing the carboxyl group from a carboxylic acid. The number of carbon atoms in the carboxylic acid residue does not include the carbon atoms in the carboxyl group. In the present invention, "polybasic acid residue" refers to an organic group obtained by removing a basic acid functional group from a polybasic acid having two or more basic acid functional groups. For example, if the polybasic acid residue is a dicarboxylic acid residue, a tricarboxylic acid residue, or a tetracarboxylic acid residue, then the dicarboxylic acid residue, the tricarboxylic acid residue, or the tetracarboxylic acid residue refers to the remaining organic group after removing the carboxyl group it possesses. The number of carbon atoms in the dicarboxylic acid residue, tricarboxylic acid residue, and tetracarboxylic acid residue does not include the carbon atoms in the carboxyl group.

[0018] The fatty chain of aliphatic diol residues of G having 2 to 20 carbon atoms may be linear or branched, and may contain alicyclic structures and / or ether bonds. Furthermore, the fatty chain of aliphatic diol residues of G may be saturated or unsaturated, having carbon-carbon unsaturated bonds.

[0019] The aliphatic diol residue of G having 2 to 20 carbon atoms is preferably an aliphatic diol residue having a branched structure with 3 to 20 carbon atoms, and more preferably a diol represented by the following general formula (G-1). [ka] (In the above general formula (G-1), p is an integer greater than or equal to 1, q is an integer greater than or equal to 0, and r is an integer greater than or equal to 1. R is a hydrogen atom or an alkyl group having 1 or more carbon atoms, and at least one of the r Rs is an alkyl group having 1 or more carbon atoms. The sum of the number of carbon atoms in p, q, r, and R is an integer between 3 and 20.

[0020] In the above general formula (G-1), the alkyl group R is preferably an alkyl group having 7 to 18 carbon atoms, and more preferably an alkyl group having 10 to 18 carbon atoms.

[0021] Examples of aliphatic diol residues of G with 2 to 20 carbon atoms include ethylene glycol residues, 1,2-propylene glycol residues, 1,3-propanediol residues, 1,2-butanediol residues, 1,3-butanediol residues, 2-methyl-1,3-propanediol residues, 1,4-butanediol residues, 1,5-pentanediol residues, 2,2-dimethyl-1,3-propanediol (neopentyl glycol) residues, 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane) residues, 2- Examples include n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane) residues, 3-methyl-1,5-pentanediol residues, 1,6-hexanediol residues, 2,2,4-trimethyl-1,3-pentanediol residues, 2-ethyl-1,3-hexanediol residues, 2-methyl-1,8-octanediol residues, 1,9-nonanediol residues, 1,10-decanediol residues, 1,12-dodecanediol residues, 1,2-tetradecanediol residues, and 1,2-dodecanediol residues.

[0022] The aliphatic diol residue of G having 2 to 20 carbon atoms may include an alicyclic structure. Examples of aliphatic diol residues having 2 to 20 carbon atoms including such an alicyclic structure include 1,3-cyclopentanediol residue, 1,2-cyclohexanediol residue, 1,3-cyclohexanediol residue, 1,4-cyclohexanediol residue, 1,2-cyclohexanedimethanol residue, and 1,4-cyclohexanedimethanol residue.

[0023] The aliphatic diol residue of G having 2 to 20 carbon atoms may include an ether bond (-O-), and examples of aliphatic diol residues having 2 to 20 carbon atoms including such ether bonds include diethylene glycol residues, triethylene glycol residues, tetraethylene glycol residues, dipropylene glycol residues, and tripropylene glycol residues.

[0024] G is preferably an aliphatic diol residue having 2 to 14 carbon atoms, and more preferably an ethylene glycol residue, a diethylene glycol residue, a 1,2-propylene glycol residue, a 1,6-hexanediol residue, a 3-methyl-1,5-pentanediol residue, a 1,4-butanediol residue, a 1,3-butanediol residue, or a 1,2-tetradecanediol residue or a 1,2-dodecanediol residue.

[0025] The fatty chain of the aliphatic dicarboxylic acid residue of A may be linear or branched, and may contain alicyclic structures and / or ether bonds. Furthermore, the fatty chain of the aliphatic dicarboxylic acid residue of A may be saturated or unsaturated, having carbon-carbon unsaturated bonds.

[0026] Examples of aliphatic dicarboxylic acid residues of A having 2 to 10 carbon atoms include malonic acid residues, succinic acid residues, glutaric acid residues, adipic acid residues, pimelic acid residues, suberic acid residues, azelaic acid residues, sebacic acid residues, dodecanedicarboxylic acid residues, maleic acid residues, fumaric acid residues, 1,2-dicarboxycyclohexane residues, and 1,2-dicarboxycyclohexene residues, with succinic acid residues, glutaric acid residues, adipic acid residues, or sebacic acid residues being preferred.

[0027] The aliphatic dicarboxylic acid residue of A having 2 to 10 carbon atoms is preferably an aliphatic dicarboxylic acid residue having 4 to 10 carbon atoms.

[0028] X 1 and X 2 The alipid chain of aliphatic polybasic acid residues having 2 to 10 carbon atoms may be linear or branched, and may contain alicyclic structures and / or ether bonds.

[0029] X 1 and X 2The aliphatic polybasic acid residue having 2 to 10 carbon atoms is preferably an aliphatic dicarboxylic acid residue having 2 to 10 carbon atoms. Examples of such aliphatic dicarboxylic acid residues having 2 to 10 carbon atoms include succinic acid residues, glutaric acid residues, adipic acid residues, pimelic acid residues, suberic acid residues, azelaic acid residues, sebacic acid residues, dodecanedicarboxylic acid residues, maleic acid residues, fumaric acid residues, 1,2-dicarboxycyclohexane residues, and 1,2-dicarboxycyclohexene residues, with succinic acid residues, glutaric acid residues, adipic acid residues, sebacic acid residues, or dodecanedicarboxylic acid residues being preferred.

[0030] X 1 and X 2 The aromatic polybasic acid residue having 6 to 15 carbon atoms is preferably an aromatic dicarboxylic acid residue having 6 to 15 carbon atoms, an aromatic tricarboxylic acid residue having 6 to 15 carbon atoms, or an aromatic tetracarboxylic acid residue having 6 to 15 carbon atoms. Specific examples of these include phthalic acid residues, trimellitic acid residues, pyromellitic acid residues, and the like.

[0031] X 1 and X 2 Preferably, it is an aliphatic dicarboxylic acid residue having 2 to 10 carbon atoms, and more preferably an aliphatic dicarboxylic acid residue having 5 to 10 carbon atoms.

[0032] The monocarboxylic acid residue of Y having 1 to 20 carbon atoms may be, for example, an aliphatic monocarboxylic acid residue having 1 to 20 carbon atoms or an aromatic monocarboxylic acid residue having 1 to 20 carbon atoms, and is preferably an aliphatic monocarboxylic acid residue having 1 to 20 carbon atoms.

[0033] When Y is an aliphatic monocarboxylic acid residue having 1 to 20 carbon atoms, the fatty chain of the aliphatic monocarboxylic acid residue having 1 to 20 carbon atoms may be linear or branched, and may contain an alicyclic structure and / or ether bonds. Furthermore, the fatty chain of the aliphatic monocarboxylic acid residue having 1 to 20 carbon atoms may be a saturated fatty chain or an unsaturated fatty chain having carbon-carbon unsaturated bonds.

[0034] Examples of monocarboxylic acid residues of Y with 1 to 20 carbon atoms include acetic acid residues, propionic acid residues, butanoic acid residues, hexanoic acid residues, octanoic acid residues, octic acid residues, benzoic acid residues, dimethylbenzoic acid residues, trimethylbenzoic acid residues, tetramethylbenzoic acid residues, ethylbenzoic acid residues, propylbenzoic acid residues, butylbenzoic acid residues, cumic acid residues, para-tertrialybutylbenzoic acid residues, orthotoluic acid residues, metatoluic acid residues, paratoluic acid residues, ethoxybenzoic acid residues, propoxybenzoic acid residues, anisic acid residues, and the like.

[0035] The monoalcohol residue of Z having 2 to 30 carbon atoms may be, for example, an aliphatic monoalcohol residue having 2 to 30 carbon atoms or an aromatic monoalcohol residue having 6 to 30 carbon atoms, and is preferably an aliphatic monoalcohol residue having 2 to 30 carbon atoms.

[0036] When Z is an aliphatic monoalcohol residue having 2 to 30 carbon atoms, the fatty chain of the aliphatic monoalcohol residue having 2 to 30 carbon atoms may be linear or branched, and may contain alicyclic structures and / or ether bonds. Furthermore, the fatty chain of the aliphatic monoalcohol residue having 2 to 30 carbon atoms may be a saturated fatty chain or an unsaturated fatty chain having carbon-carbon unsaturated bonds.

[0037] The monoalcohol residue of Z having 2 to 30 carbon atoms is preferably an alkylalcohol residue having 2 to 10 carbon atoms or an alcohol residue of a polyalkylene glycol monoalkyl ether having 5 to 30 carbon atoms.

[0038] Examples of alkyl alcohol residues with 2 to 10 carbon atoms in Z include ethanol residues, propanol residues, butanol residues, pentanol residues, hexanol residues, cyclohexanol residues, heptanol residues, octanol residues, nonanol residues, and decanol residues.

[0039] Examples of alcohol residues in polyalkylene glycol alkyl ethers with 5 to 30 carbon atoms in Z include polyethylene glycol alkyl ethers such as diethylene glycol monomethyl ether and triethylene glycol monomethyl ether; polypropylene glycol alkyl ethers such as polypropylene glycol monomethyl ether and polypropylene glycol monoethyl ether; and alcohol residues such as (polyethylene glycol-polypropylene glycol) monoalkyl ether.

[0040] The average value of the number of repetitions of n is preferably in the range of 0 to 20, more preferably in the range of 0.2 to 15, and more preferably in the range of 0.5 to 10. The average number of repeats of n can be calculated from the number-average molecular weight of the polyester of the present invention.

[0041] p is X 1 q is an integer obtained by subtracting one from the number of basic acid functional groups in the aliphatic polybasic acid residue or aromatic polybasic acid residue, where q is X 2 It is an integer obtained by subtracting one from the number of basic acid functional groups in the aliphatic polybasic acid residue or aromatic polybasic acid residue. Therefore, for example X 1 and X 2 However, if each is independently an aliphatic dicarboxylic acid residue with 2 to 10 carbon atoms, then X 1 and X 2 The number of basic acid functional groups (carboxyl groups) that each possesses becomes 2, and p and q each become 1, so the general formulas (1-1) and (1-2) above become as follows.

[0042] [ka]

[0043] The polyester of the present invention may be any polyester that satisfies the above general formula (1-1) or (1-2), and may be used as a mixture of two or more polyesters with different structures.

[0044] The number-average molecular weight (Mn) of the polyester of the present invention is, for example, in the range of 500 to 5,000, preferably in the range of 1,000 to 5,000, more preferably in the range of 1,500 to 5,000, and even more preferably in the range of 1,500 to 4,000. By setting the lower limit of the number-average molecular weight to 1,500 or higher, a particularly good effect on improving dispersibility can be expected. The above number-average molecular weight (Mn) is a value converted to polystyrene based on gel permeation chromatography (GPC) measurement, and is measured by the method described in the examples.

[0045] The acid value of the polyester of the present invention is in the range of 3 to 400 mg KOH / g, preferably in the range of 3 to 100 mg KOH / g, and more preferably in the range of 3 to 50 mg KOH / g. The acid value of the above polyester is confirmed by the method described in the examples.

[0046] The properties of the polyester of the present invention vary depending on the number-average molecular weight and composition, but it is preferably liquid at room temperature. Here, "liquid at room temperature" means that the polyester of the present invention exhibits fluidity at normal pressure and room temperature of 25°C.

[0047] The content of the dispersant in the electrode mixture is not particularly limited, but for example, it is in the range of 0.01 to 30 parts by mass of dispersant per 100 parts by mass of electrode active material, preferably in the range of 0.05 to 10 parts by mass of dispersant per 100 parts by mass of electrode active material, and more preferably in the range of 0.1 to 5.0 parts by mass of dispersant per 100 parts by mass of electrode active material.

[0048] The content of the dispersant in the electrode mixture is not particularly limited, but for example, it is in the range of 0.01 to 30 parts by mass of dispersant per 100 parts by mass of the total of the electrode active material and solid electrolyte, preferably in the range of 0.05 to 10 parts by mass of dispersant per 100 parts by mass of the total of the electrode active material and solid electrolyte, and more preferably in the range of 0.05 to 5.0 parts by mass of dispersant per 100 parts by mass of the total of the electrode active material and solid electrolyte.

[0049] The polyester of the present invention is obtained using reaction raw materials comprising aliphatic diols, aliphatic dicarboxylic acids, aliphatic polybasic acids and / or aromatic polybasic acids, and monoalcohols and / or monocarboxylic acids. Here, "reaction raw materials" means the raw materials that constitute the polyester of the present invention, and does not include solvents or catalysts that do not constitute the polyester. The method for producing polyester according to the present invention is not particularly limited and can be produced by known methods, or by the production method described later.

[0050] The reaction raw materials for the polyester of the present invention may include aliphatic diols, aliphatic dicarboxylic acids, aliphatic polybasic acids and / or aromatic polybasic acids, and monoalcohols and / or monocarboxylic acids, and may also include other raw materials. The reaction raw materials for the polyester of the present invention preferably consist of 90% by mass or more of aliphatic diols, aliphatic dicarboxylic acids, aliphatic polybasic acids and / or aromatic polybasic acids, and monoalcohols and / or monocarboxylic acids, relative to the total amount of the reaction raw materials, and more preferably consist only of aliphatic diols, aliphatic dicarboxylic acids, aliphatic polybasic acids and / or aromatic polybasic acids, and monoalcohols and / or monocarboxylic acids.

[0051] The aliphatic diol used in the production of the polyester of the present invention is an aliphatic diol corresponding to an aliphatic diol residue of G having 2 to 20 carbon atoms. The aliphatic diol used may be one type alone or two or more types may be used in combination. The aliphatic dicarboxylic acid used in the production of the polyester of the present invention is an aliphatic dicarboxylic acid corresponding to an aliphatic dicarboxylic acid residue of A having 2 to 10 carbon atoms. The aliphatic dicarboxylic acid used may be used alone or in combination of two or more types. The aliphatic polybasic acid used in the production of the polyester of the present invention is X 1 and X 2 These are aliphatic polybasic acids corresponding to aliphatic polybasic acid residues with 2 to 10 carbon atoms. The aliphatic polybasic acids used may be used alone or in combination of two or more. The aromatic polybasic acid used in the production of the polyester of the present invention is X 1 and X 2 These are aromatic polybasic acids corresponding to aromatic polybasic acid residues with 6 to 15 carbon atoms. The aromatic polybasic acids used may be used individually or in combination of two or more. The monocarboxylic acid used in the production of the polyester of the present invention is a monocarboxylic acid corresponding to a monocarboxylic acid residue of Y having 1 to 20 carbon atoms. The monocarboxylic acid used may be one type alone or two or more types may be used in combination. The monoalcohol used in the production of the polyester of the present invention is a monoalcohol corresponding to a monoalcohol residue of Z having 2 to 30 carbon atoms. The monoalcohol used may be one type alone or two or more types may be used in combination.

[0052] If the polybasic acid (aliphatic polybasic acid and / or aromatic polybasic acid) used as a reaction material is an aliphatic dicarboxylic acid, the reaction material may include an aliphatic diol, an aliphatic dicarboxylic acid, a monoalcohol and / or a monocarboxylic acid.

[0053] Hydrogenated vegetable oil fatty acids may be used as monocarboxylic acids in the production of the polyester of the present invention. Examples of such hydrogenated vegetable oil fatty acids include hydrogenated coconut oil fatty acids, hydrogenated palm kernel oil fatty acids, hydrogenated palm oil fatty acids, hydrogenated olive oil fatty acids, hydrogenated castor oil fatty acids, and hydrogenated rapeseed oil fatty acids. These are obtained by hydrolysis and hydrogenation of oils obtained from coconut, palm kernel, palm, olive, castor, and rapeseed, respectively, and are all mixtures of two or more long-chain aliphatic monocarboxylic acids containing aliphatic monocarboxylic acids with 8 to 21 carbon atoms. Furthermore, as the monocarboxylic acid used in the production of the polyester of the present invention, the above-mentioned unhydrogenated vegetable oil fatty acids may be used, provided that they do not impair the effects of the present invention. Also, the vegetable oil fatty acids are not limited to those mentioned above.

[0054] When the polyester of the present invention is a polyester reacted with an aliphatic diol, an aliphatic dicarboxylic acid, an aliphatic polybasic acid and / or an aromatic polybasic acid, and a hydrogenated vegetable oil fatty acid, the resulting polyester is obtained as a mixture of two or more polyesters represented by the general formula (1-1).

[0055] The aliphatic diols, aliphatic dicarboxylic acids, aliphatic polybasic acids, aromatic polybasic acids, monoalcohols, and monocarboxylic acids used in the production of the polyester of the present invention can all be derivatives thereof. Examples of such derivatives include esterified products, acid chlorides, acid anhydrides, and cyclic esters. For example, since epoxy compounds undergo ring-opening to form diols when reacting with carboxylic acids, aliphatic epoxy compounds may be used as derivatives of aliphatic diols used as reaction raw materials in the present invention.

[0056] The polyester represented by the general formula (1-1) can be produced, for example, by reacting an aliphatic diol, an aliphatic dicarboxylic acid, an aliphatic polybasic acid and / or an aromatic polybasic acid and a monocarboxylic acid all at once, with the equivalent amount of carboxyl groups being greater than the equivalent amount of hydroxyl groups. Alternatively, the polyester represented by the general formula (1-1) can also be produced, for example, by reacting an aliphatic diol and an aliphatic dicarboxylic acid in any equivalent ratio, and then reacting the terminal hydroxyl groups of the resulting polyester with a monocarboxylic acid and an aliphatic polybasic acid and / or an aromatic polybasic acid to encapsulate the hydroxyl groups with carboxylic acid residues.

[0057] The polyester represented by the general formula (1-2) can be produced, for example, by reacting an aliphatic diol, an aliphatic dicarboxylic acid, an aliphatic polybasic acid and / or an aromatic polybasic acid and a monoalcohol all at once, with the amount of carboxyl groups being greater than the amount of hydroxyl groups. Alternatively, the polyester represented by the general formula (1-2) can also be produced, for example, by reacting an aliphatic diol and an aliphatic dicarboxylic acid in any equivalent ratio, and then reacting the ends of the resulting polyester with a monoalcohol and an aliphatic polybasic acid and / or an aromatic polybasic acid.

[0058] In the production of polyester according to the present invention, the reaction of the reaction raw materials may be carried out in the presence of an esterification catalyst as needed, for example, in a temperature range of 170 to 250°C for 10 to 25 hours. Furthermore, the temperature, time, and other conditions for the esterification reaction are not particularly limited and may be set as appropriate.

[0059] Examples of the esterification catalysts include titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate; zinc-based catalysts such as zinc acetate; tin-based catalysts such as tin octoate and dibutyltin oxide; and organic sulfonic acid-based catalysts such as p-toluenesulfonic acid.

[0060] The amount of esterification catalyst used can be set as appropriate, but it is usually used in the range of 0.0001 to 0.1 parts by mass per 100 parts by mass of the total amount of reaction raw materials.

[0061] (electrode active material) As for the electrode active materials, a positive electrode active material and a negative electrode active material are selected depending on whether the electrode composite material is used for the positive electrode or the negative electrode.

[0062] Examples of positive electrode active materials include oxide-based positive electrode active materials and sulfide-based positive electrode active materials.

[0063] Examples of the oxide-based positive electrode active material include lithium-containing transition metal composite oxides such as LMO (lithium manganate), LCO (lithium cobaltate), NMC (lithium nickel manganese cobaltate), NCA (lithium nickel cobalt aluminate), LNCO (lithium nickel cobaltate), and lithium-containing olivine-type phosphates (LiMePO4, Me = Fe, Co, Ni, Mn).

[0064] Specific examples of the oxide-based positive electrode active material include rock salt layer-type active materials such as LiCoO2, LiMnO2, LiNiO2, LiVO2, LiNi x Co y Mn z O2; spinel-type active materials such as LiMn2O4, Li4Ti5O 12 、Li(Ni 0.5 Mn 1.5 )O4; olivine-type active materials such as LiFePO4, LiMnPO4, LiNiPO4, LiCoPO4, and lithium manganese iron phosphate (LiMn x Fe 1-x PO4; 0 < x < 1), etc.

[0065] Examples of the sulfide-based positive electrode active material include titanium sulfide (TiS2), molybdenum sulfide (MoS2), iron sulfide (FeS, FeS2), copper sulfide (CuS), nickel sulfide (Ni3S2), etc. In addition, niobium selenide (NbSe3), etc. can also be used.

[0066] The positive electrode active material may be used alone or in combination of two or more.

[0067] Examples of the negative electrode active material include metallic lithium such as metallic lithium, metallic indium, metallic aluminum, metallic silicon, metallic tin, etc., metals that can form an alloy with metallic lithium, oxides of these metals, and alloys of these metals and metallic lithium, etc. <S

[0068] The electrode active material may be, for example, an electrode active material having a coating layer with a coated surface. Materials used to form the coating layer include ion conductors such as lithium nitrides, lithium oxides, or composites thereof.

[0069] Specific examples of coating material include, for example, Li 4-2x Zn x Conductors having a lithicon-type crystal structure such as GeO4, and conductors having a Li3PO4-type skeletal structure, such as Li3PO4. 4-x Ge 1-x P x Conductors having a thiolysicone-type crystal structure such as S4, La 2 / 3-x Li 3x Examples include conductors having a perovskite-type crystal structure such as TiO3, and conductors having a NASICON-type crystal structure such as LiTi2(PO4)3. In addition to the above, Li y Ti 3-y O4(0 <y<3)、Li4Ti5O 12 Other examples include lithium titanate compounds such as (LTO), lithium metal oxide compounds of metals belonging to Group 5 of the periodic table such as LiNbO3 and LiTaO3, and conductors of boron oxide / phosphorus oxide compounds such as the Li2O-B2O3-P2O5 system, Li2O-B2O3-ZnO system, and Li2O-Al2O3-SiO2-P2O5-TiO2 system.

[0070] The coating can be formed by known methods, for example, by attaching the electrode active material to a solution containing a material for forming the coating layer, and then firing the electrode active material after attachment.

[0071] The coverage rate of the coating layer is preferably 90% or more, more preferably 95% or more, and even more preferably 100%, based on the surface area of ​​the electrode active material, i.e., the entire surface is covered. The thickness of the coating layer is preferably 1 nm or more, more preferably 2 nm or more, with an upper limit of preferably 30 nm or less, and more preferably 25 nm or less. Furthermore, the thickness of the coating layer can be measured by cross-sectional observation using a transmission electron microscope (TEM), and the coverage ratio can be calculated from the thickness of the coating layer, elemental analysis values, and BET specific surface area.

[0072] (solid electrolyte) Examples of solid electrolytes include sulfide solid electrolytes and oxide solid electrolytes.

[0073] A sulfide solid electrolyte is a solid electrolyte containing a metal element (M) such as Li, Na, K, Mg, Ca, and sulfur (S). Preferably, it is a sulfide solid electrolyte containing lithium and sulfur, and more preferably, it is a sulfide solid electrolyte containing lithium, sulfur, and one or more elements selected from the group consisting of P, Si, Ge, Al, and B. The sulfide solid electrolyte may optionally further contain halogen elements such as Cl, Br, and I, or oxygen such as O.

[0074] Specific examples of sulfide solid electrolytes include Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, and Li2S-P2S5-Z. m S n (However, m and n are positive numbers. Z is one of Ge, Zn, or Ga.) Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (However, x and y are positive numbers. M is one of P, Si, Ge, B, Al, Ga, or In.) These are some examples. For example, the description "Li2S-P2S5" above refers to a sulfide solid electrolyte obtained using reaction materials containing Li2S and P2S5. The same applies to other descriptions.

[0075] The sulfide solid electrolyte may be either an amorphous sulfide solid electrolyte or a crystalline sulfide solid electrolyte. Amorphous sulfide solid electrolytes can be produced, for example, by mechanical milling the reaction raw materials. Crystallized sulfide solid electrolytes can be produced, for example, by heat-treating amorphous sulfide solid electrolytes at a temperature above their crystallization temperature.

[0076] Examples of oxide solid electrolytes include NASICON-type oxides, garnet-type oxides, and perovskite-type oxides. Examples of NASICON-type oxides include oxides containing Li, Al, Ti, P, and O (e.g., Li 1.5 Al 0.5 Ti 1.5 Examples of garnet-type oxides include oxides containing Li, La, Zr, and O (e.g., Li7La3Zr2O). 12 ), oxides containing Li, La, Zr, Ta and O (Li 7-x La3Zr 2-x Ta x O 12 Examples of perovskite-type oxides include those containing Li, La, Ti, and O (e.g., LiLaTiO3).

[0077] When the electrode mixture contains both an electrode active material and a solid electrolyte, the mass ratio of the electrode active material to the solid electrolyte is, for example, in the range of electrode active material:solid electrolyte (mass ratio) = 99.5:0.5 to 40:60, preferably in the range of electrode active material:solid electrolyte (mass ratio) = 99:1 to 50:50, and more preferably in the range of electrode active material:solid electrolyte (mass ratio) = 98:2 to 60:40.

[0078] (Other ingredients) The electrode composite material of the present invention may contain an electrode active material and / or a solid electrolyte and a dispersant, and may also contain other components as long as they do not impair the effects of the present invention. Examples of such other components include conductive materials and binders.

[0079] Examples of conductive materials include carbon-based materials such as artificial graphite, graphite carbon fiber, resin-fired carbon, pyrolysis vapor-grown carbon, coke, mesocarbon microbeads, furfuryl alcohol resin-fired carbon, polyacene, pitch-based carbon fiber, vapor-grown carbon fiber, natural graphite, non-graphitizable carbon, and carbon nanotubes (multiwall, singlewall).

[0080] When the electrode composite material of the present invention contains a conductive material, there are no particular restrictions on the content of the conductive material in the electrode composite material. However, considering the improvement of battery performance and manufacturing efficiency, the lower limit is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more, and the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less.

[0081] Examples of binders include fluorine-based polymers such as polytetrafluoroethylene and polyvinylidene fluoride, thermoplastic elastomers such as butylene rubber and styrene-butadiene rubber, and various resins such as acrylic resins, acrylic polyol resins, polyvinyl acetal resins, polyvinyl butyral resins, and silicone resins.

[0082] When the electrode mixture of the present invention contains a binder, there are no particular restrictions on the amount of binder in the electrode mixture, but the lower limit is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, and the upper limit is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0083] Electrode mixtures can be manufactured by mixing a solid electrolyte and / or electrode active material, a dispersant, and any other components in a known manner.

[0084] [Secondary battery] By using the electrode composite material of the present invention, battery components for secondary batteries can be manufactured, and such secondary batteries include, for example, all-solid-state batteries in which the electrolyte is solid and lithium-ion batteries in which the electrolyte is liquid.

[0085] [All-solid battery] The all-solid-state battery of the present invention is an all-solid-state battery having a positive electrode layer, a solid electrolyte layer, and a negative electrode layer in that order, wherein one or more of the positive electrode layer, solid electrolyte layer, and negative electrode layer contain a dispersant which is the polyester of the present invention. The electrode composite material of the present invention is suitable for battery components of all-solid-state batteries. For example, if the electrode composite material of the present invention contains a positive electrode active material, it can form a positive electrode layer. For example, if the electrode composite material of the present invention contains a negative electrode active material, it can form a negative electrode layer. For example, if the electrode composite material of the present invention does not contain an electrode active material but contains a solid electrolyte, it can form a solid electrolyte layer. Furthermore, the positive electrode layer and the negative electrode layer may each contain a solid electrolyte.

[0086] The configuration of the all-solid-state battery of the present invention preferably comprises a positive electrode current collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector in this order. Examples of positive electrode materials include foil-like, plate-like, and porous materials made of aluminum, aluminum alloys, stainless steel, nickel, iron, titanium, etc. Examples of negative electrode current collectors include foil-like materials, plate-like materials, porous materials, etc., made of nickel, copper, stainless steel, etc.

[0087] The all-solid-state battery of the present invention can be manufactured by known methods. For example, the positive electrode layer and the negative electrode layer can each be manufactured by coating the electrode mixture slurry of the present invention onto a current collector and drying it.

[0088] Examples of solvents used to form the electrode mixture slurry include ketone compounds such as methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, dibutyl ketone, and diisobutyl ketone; ether compounds such as diethylene glycol diethyl ether, cyclopentyl methyl ether, dibutyl ether, dipentyl ether, and anisole; and ester compounds such as ethyl butyrate, butyl butyrate, and 2-methylbutyrate butyl.

[0089] The electrode mixture slurry can be prepared by known methods, and the viscosity of the electrode mixture slurry can be set arbitrarily.

[0090] The means for coating the electrode mixture slurry onto the surface of the current collector are not particularly limited, and methods such as inkjet printing, screen printing, CVD, and sputtering can be used, as well as known coating methods such as doctor blades. The total thickness of the electrode layer and the current collector after drying (electrode thickness) is not particularly limited, but is, for example, in the range of 0.1 μm to 1 mm, and preferably in the range of 1 μm to 200 μm.

[0091] A solid electrolyte layer can be formed by, for example, a process such as pressing a solid electrolyte. Alternatively, the solid electrolyte layer can be formed by applying a slurry solution of a solid electrolyte, prepared by dispersing a solid electrolyte material in a solvent, to the surface of a substrate or electrode. The thickness of the solid electrolyte layer is not particularly limited, but is, for example, 0.1 μm to 1 mm, and preferably 1 μm to 100 μm.

[0092] [Lithium-ion battery] The electrode composite material of the present invention can also be suitably used as a battery component in lithium-ion batteries, where the electrolyte is liquid. Generally, a lithium secondary battery consists of a positive electrode, a negative electrode, a separator sandwiched between the positive and negative electrodes, and an electrolyte. Here, the separator is, for example, a laminate in which a coating layer is formed by applying and drying a secondary battery separator coating composition containing inorganic particles and a binder resin on a substrate.

[0093] (Inorganic particles) The separator serves to prevent physical contact between the negative electrode and the positive electrode and allows metal ions such as lithium ions to pass through pores. However, when the separator is only the base material (without a coating layer), there is a problem that the separator may be damaged by the charge of metal particles moving between the separators during the charge / discharge process of the secondary battery. The inorganic particles are for increasing the strength of the separator.

[0094] As the inorganic particles contained in the coating composition for the secondary battery separator, for example, one or more selected from the group consisting of BaTiO3, Pb(Zr,Ti)O3, Pb 1-x La x Zr 1-y TiyO3(0 < x < 1, 0 < y < 1), Pb(Mg 1 / 3 Nb 2 / 3 )O3 - PbTiO3, HfO2, SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiC can be used.

[0095] The inorganic particles are not limited to the above, and lithium phosphate (Li3PO4), lithium titanium phosphate (Li p Ti q (PO4)3, 0 < p < 2, 0 < q < 3), lithium aluminum titanium phosphate (Li a Al b Ti c (PO4)3, 0 < a < 2, 0 < b < 1, 0 < c < 3), 14Li2O9Al2O338TiO239P2O5 etc. (LiAlTiP) d O e glass 0 < d < 4, 0 < e < 13), lithium lanthanum titanate (Li e La f TiO3, 0 < e < 2, < f < 3), Li 3.25 Ge 0.25 P 0.75 S such as 4 etc. lithium germanium thiophosphate (Li g Ge h P i S j, (0 < g < 4, 0 < h < 1, 0 < i < 1, 0 < j < 5), lithium nitride such as Li3N (Li k N l , (0 < k < 4, 0 < l < 2), SiS2 glass such as Li3PO4 - Li2S - SiS2 (Li m Si n S o , (0 < m < 3, 0 < n < 2, 0 < o < 4), inorganic particles having lithium ion conductivity such as P2S5 glass such as LiI - Li2S - P2S5 can also be used.

[0096] The particle size of the inorganic particles is not particularly limited, but D 50 measured by the laser diffraction method is, for example, in the range of 0.1 to 10 μm, preferably in the range of 0.2 to 5 μm. Similarly, D 90 measured by the laser diffraction method is, for example, 30 μm or less, preferably in the range of 10 to 25 μm.

[0097] When the coating composition for the secondary battery separator is 100 parts by mass, the content of the inorganic particles is, for example, in the range of 0.5 to 40 parts by mass, preferably in the range of 5 to 30 parts by mass, and more preferably in the range of 10 to 20 parts by mass.

[0098] The polyester of the present invention may be added as a dispersant for improving the dispersibility of the inorganic particles. The content of the polyester of the present invention may be, for example, in the range of 0.1 to 10.0 parts by mass with respect to 100 parts by mass of the inorganic particles, preferably in the range of 0.1 to 5.0 parts by mass, more preferably in the range of 0.2 to 2.0 parts by mass, and still more preferably in the range of 0.8 to 1.8 parts by mass.

[0099] (Binder resin) As the binder resin contained in the coating composition for secondary battery separators, one or more selected from the group consisting of aliphatic conjugated diene / aromatic monovinyl copolymer, (meth)acrylic polymer, fluoropolymer, (meth)acrylic acid / (meth)acrylamide copolymer, (meth)acrylonitrile polymer, and aromatic monovinyl / (meth)acrylic copolymer can be used.

[0100] Specific examples of binder resins include polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylpyrrolidone, polyacrylonitrile, polyvinylidene fluoride-trichloroethylene, polyvinylidene fluoride-chlorotrifluoroethylene, polymethyl methacrylate, polyvinyl acetate, ethylene vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethylcellulose, cyanoethyl sucrose, pullulan, carboxymethylcellulose, acrylonitrile styrene butadiene copolymer, and polyimide.

[0101] The binder resin content is, for example, in the range of 10 to 50 parts by mass per 100 parts by mass of inorganic particles, preferably in the range of 15 to 45 parts by mass, and more preferably in the range of 20 to 40 parts by mass.

[0102] (solvent) The solvent is used to ensure the coating properties of the secondary battery separator coating composition of the present invention, and is not particularly limited as long as it is a solvent that can dissolve inorganic particles and binder resin to a certain level or higher.

[0103] As a solvent, one or more selected from the group consisting of acetone, tetrahydrofuran, acetonitrile, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrole, and water can be used.

[0104] The solvent content should be set so that the coating composition for secondary battery separators becomes, for example, a slurry. For example, if the coating composition for secondary battery separators is 100 parts by mass, the solvent content should be in the range of 30 to 90 parts by mass, preferably in the range of 40 to 90 parts by mass, and more preferably in the range of 50 to 85 parts by mass.

[0105] The coating composition for secondary battery separators may contain, for example, inorganic particles, a binder resin, a solvent, and any dispersant of the present invention, and may also contain other components. Examples of such other components include thickeners, defoamers, pH adjusters, viscosity modifiers, and redox shuttle agents.

[0106] The coating composition for secondary battery separators may substantially consist of inorganic particles, a binder resin, a solvent, and any dispersant of the present invention. Herein, "substantially" means that the total of the inorganic particles, the binder resin, the solvent, and any dispersant of the present invention constitutes 80% or more by mass, 90% or more by mass, 95% or more by mass, 99% or more by mass, or 100% by mass of the coating composition for secondary battery separators.

[0107] The secondary battery separator is a laminate having a substrate and a coating layer formed from a coating composition for secondary battery separators, wherein the coating layer may be arranged on at least one surface of the substrate.

[0108] The substrate serves to prevent physical contact between the negative and positive electrodes, while also allowing metal ions, such as lithium ions, to pass through its pores. As a base material, a porous polymer film made from one or more resins selected from the group consisting of polyolefin resin, fluororesin, polyester resin, polyacrylonitrile resin, and cellulose resin can be used.

[0109] The substrate is preferably a porous polymer film made of one or more materials selected from the group consisting of polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene terephthalate, and polybutylene terephthalate.

[0110] The lower limit of the substrate thickness is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. Similarly, the upper limit of the substrate thickness is preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less.

[0111] The coating layer is formed, for example, by applying and drying a coating composition for secondary battery separators onto a substrate, and can be formed by known methods. The lower limit of the coating layer thickness is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 3 μm or more. The upper limit of the coating layer thickness is preferably 10 μm or less, more preferably 8 μm or less.

[0112] As the electrolyte, an organic electrolyte containing a dissolved supporting electrolyte can be used. Examples of the above-mentioned supporting electrolytes include LiPF6, LiAsF6, LiBF4, LiSbF6, LiAlCl4, LiClO4, CF3SO3Li, C4F9SO3Li, CF3COOLi, (CF3CO)2NLi, (CF3SO2)2NLi, and (C2F5SO2)NLi.

[0113] Examples of organic solvents for dissolving the supporting electrolyte include carbonates such as dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), butylene carbonate (BC), ethyl methyl carbonate (EMC), and vinylene carbonate (VC); esters such as γ-butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane and tetrahydrofuran; and sulfur-containing compounds such as sulfolane and dimethyl sulfoxide.

[0114] The positive and negative electrodes of a lithium-ion battery can be those of known type, and it is preferable to use the same type as those used in all-solid-state batteries.

[0115] Lithium-ion batteries can be manufactured, for example, by stacking a positive electrode and a negative electrode with a separator in between, winding or folding them as needed, placing them in a battery container, and then injecting an electrolyte into the battery container and sealing it. The battery container may also contain, as needed, expanded metal, fuses, overcurrent protection elements such as PTC elements, lead plates, etc., to prevent pressure buildup and overcharging / discharging inside the battery. Examples of rechargeable battery shapes include coin-type, button-type, sheet-type, cylindrical, rectangular, and flat-type batteries. [Examples]

[0116] The present invention will be specifically described below with reference to examples and comparative examples. Furthermore, the present invention is not limited to the following embodiments.

[0117] In the embodiments of this application, the acid value and hydroxyl value are values ​​evaluated by the following method. [Method for measuring acid value] Measurements were taken according to the method compliant with JIS K0070-1992. [Method for measuring hydroxyl value] Measurements were taken according to the method compliant with JIS K0070-1992.

[0118] In the embodiments of this invention, the number-average molecular weight of polyester is a value converted to polystyrene based on GPC measurement, and the measurement conditions are as follows. [GPC measurement conditions] Measurement device: Tosoh Corporation high-speed GPC system "HLC-8320GPC" Columns: Tosoh Corporation's "TSKGURDCOLUMNSuperHZ-L" + Tosoh Corporation's "TSKgelSuperHZM-M" + Tosoh Corporation's "TSKgelSuperHZM-M" + Tosoh Corporation's "TSKgelSuperHZ-2000" + Tosoh Corporation's "TSKgelSuperHZ-2000" Detector: RI (Differential Refractometer) Data processing: EcoSEC Data Analysis version 1.07 manufactured by Tosoh Corporation. Column temperature: 40℃ Developing solvent: tetrahydrofuran Flow rate: 0.35mL / min Measurement sample: 7.5 mg of the sample was dissolved in 10 ml of tetrahydrofuran, and the resulting solution was filtered through a microfilter to be used as the measurement sample. Sample injection volume: 20 μl Standard sample: In accordance with the measurement manual for "HLC-8320GPC" mentioned above, the following monodisperse polystyrenes with known molecular weights were used.

[0119] (Monodisperse polystyrene) "A-300" manufactured by Tosoh Corporation "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation Tosoh Corporation's "F-10" F-20 manufactured by Tosoh Corporation Tosoh Corporation's "F-40" Tosoh Corporation's "F-80" Tosoh Corporation's "F-128" Tosoh Corporation's "F-288"

[0120] (Synthesis Example 1: Preparation of Dispersant A) A 5-liter four-neck flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with 676.3 g of 1,4-butylene glycol and 781.3 g of neopentyl glycol as glycol components, 2456.4 g of adipic acid as a dicarboxylic acid component, 259.7 g of isononyl alcohol as a monoalcohol component, and 0.13 g of tetra-isopropyl titanate as a catalyst. Under a nitrogen stream, the temperature was gradually raised to 220°C over 5 hours and a condensation reaction was carried out at 220°C for 8 hours. After the reaction, unreacted raw materials and low-volatile components were removed under reduced pressure at 200°C to obtain a polyester-based dispersant A. The obtained dispersant A was a viscous liquid at room temperature, with an acid value of 35.5 mgKOH / g, a hydroxyl value of 1.4 mgKOH / g, and a number-average molecular weight of 2,320.

[0121] (Examples 1-4 and Comparative Examples 1-3: Preparation and Evaluation of Electrode Composite Materials) The dispersant, cathode active material, and solvent shown in Table 1 were blended at the ratios shown in Table 1 and stirred for 2 minutes at 1,000 rpm and 0.2 Pa using a planetary stirring device (THINKY ARV-310) to obtain a paste-like electrode composite material.

[0122] The cathode active materials used are as follows. NCM622: LiNi 0.6 Mn 0.2 Co 0.2 O2 NCM811: LiNi 0.8 Co 0.1 Mn 0.1 O2 LFP: LiFePO4

[0123] (Viscosity) For the prepared electrode composite material, the viscosity of the electrode composite material at a predetermined shear rate [1 / S] was measured using a rotational viscometer (RST-CPS manufactured by Eiko Seiki Co., Ltd.). Specifically, the electrode composite material was measured at a measurement temperature of 25°C and a shear rate of 50 [1 / S], and the value was read. The results are shown in Table 1.

[0124]

Table 1

[0125] The results in Table 1 show that the viscosity of the electrode mixture was significantly reduced by adding a dispersant, indicating that the positive electrode active material was well dispersed.

[0126] (Example 6: Manufacturing of an all-solid-state battery) Cathode active material LiNi 0.6 Mn 0.2 Co 0.2 6.7g of O2 (NCM622), 0.1g of dispersant A, and solid electrolyte Li 6.6 La3Zr 1.6 Ta 0.4 O 12 A positive electrode slurry was prepared by mixing 3.0 g of [substance name], 0.2 g of acetylene black, and 1 g of a 10% by mass butyl butyrate solution of styrene-butadiene rubber binder with butyl butyrate as a solvent. This positive electrode slurry was coated onto aluminum foil, which served as the current collector, using an automatic bar coater and dried to produce a positive electrode layer containing dispersant A.

[0127] Solid electrolyte Li 6.6 La3Zr 1.6 Ta 0.4 O 12 A solid electrolyte slurry was prepared by mixing 9.9 g of [the substance] with 1 g of a 10% by mass butyl butyrate solution of styrene-butadiene rubber binder, adding butyl butyrate as a solvent. The obtained solid electrolyte slurry was coated onto a PET film using an automatic bar coater, and after drying, the PET film was peeled off to obtain a solid electrolyte layer.

[0128] Using the manufactured positive electrode layer and solid electrolyte layer, a positive electrode half-cell 1 was fabricated by placing the positive electrode layer, solid electrolyte layer, and indium-lithium alloy counter electrode, each punched out in a 10 mm diameter circle, into a ceramic tube with an inner diameter of 10 mm, and then press-molding the tube.

[0129] (Example 7: Manufacturing of an all-solid-state battery) Cathode active material LiNi 0.6 Mn 0.2 Co 0.26.7g of O2 (NCM622), solid electrolyte Li 6.6 La3Zr 1.6 Ta 0.4 O 12 A positive electrode slurry was prepared by mixing 3.0 g of [material name], 0.2 g of acetylene black, and 1 g of a 10% by mass butyl butyrate solution of styrene-butadiene rubber binder with butyl butyrate as a solvent. This positive electrode slurry was coated onto aluminum foil, which served as the current collector, using an automatic bar coater and dried to produce the positive electrode layer.

[0130] Solid electrolyte Li 6.6 La3Zr 1.6 Ta 0.4 O 12 A solid electrolyte slurry was prepared by mixing 9.9 g of [component name], 0.1 g of dispersant A, and 1 g of a 10% by mass butyl butyrate solution of styrene-butadiene rubber binder with butyl butyrate as a solvent. The obtained solid electrolyte slurry was coated onto a PET film using an automatic bar coater, and after drying, the PET film was peeled off to obtain a solid electrolyte layer containing dispersant A.

[0131] Using the manufactured positive electrode layer and solid electrolyte layer, a positive electrode half-cell 2 was fabricated by placing the positive electrode layer, solid electrolyte layer, and indium-lithium alloy counter electrode, each punched out in a 10 mm diameter circle, into a ceramic tube with an inner diameter of 10 mm, and then press-molding the tube.

[0132] (Comparative Example 5: Manufacturing of All-Solid-State Batteries) Cathode active material LiNi 0.6 Mn 0.2 Co 0.2 6.7g of O2 (NCM622), solid electrolyte Li 6.6 La3Zr 1.6 Ta 0.4 O 12 A positive electrode slurry was prepared by mixing 3.0 g of [material name], 0.2 g of acetylene black, and 1 g of a 10% by mass butyl butyrate solution of styrene-butadiene rubber binder with butyl butyrate as a solvent. This positive electrode slurry was coated onto aluminum foil, which served as the current collector, using an automatic bar coater and dried to produce the positive electrode layer.

[0133] Solid electrolyte Li6.6 La3Zr 1.6 Ta 0.4 O 12 A solid electrolyte slurry was prepared by mixing 9.9 g of [the substance] with 1 g of a 10% by mass butyl butyrate solution of styrene-butadiene rubber binder, adding butyl butyrate as a solvent. The obtained solid electrolyte slurry was coated onto a PET film using an automatic bar coater, and after drying, the PET film was peeled off to obtain a solid electrolyte layer containing dispersant A.

[0134] Using the manufactured positive electrode layer and solid electrolyte layer, a positive electrode half-cell 1' was fabricated by placing the positive electrode layer, solid electrolyte layer, and indium-lithium alloy counter electrode, each punched out in a 10 mm diameter circle, into a ceramic tube with an inner diameter of 10 mm, and then press-molding the tube.

[0135] (Evaluation of all-solid-state batteries) The battery capacity [mAh / g] was measured for each of the manufactured positive electrode half-cells 1, 2, and 1'. The battery charge / discharge conditions were 25°C and a charge / discharge rate of 0.1c. Charge / discharge cycles were repeated, and the discharge capacity after the 5th cycle was defined as the battery capacity. When the battery capacity of positive electrode half cell 1', which does not contain dispersant A in either the positive electrode layer or the solid electrolyte layer, is set to 100, both positive electrode half cell 1, which contains dispersant A in the positive electrode layer, and positive electrode half cell 2, which contains dispersant A in the solid electrolyte layer, showed an improvement in battery capacity of 20% or more.

Claims

1. An electrode mixture containing an electrode active material and / or a solid electrolyte and a dispersant, An electrode mixture in which the dispersant is a polyester represented by the following general formula (1-1) or (1-2). 【Chemistry 1】 (In the above general formulas (1-1) and (1-2), G is an aliphatic diol residue with 2 to 20 carbon atoms. A is an aliphatic dicarboxylic acid residue having 2 to 10 carbon atoms. X １ and X ２ Each of these is independently an aliphatic polybasic acid residue having 2 to 10 carbon atoms or an aromatic polybasic acid residue having 6 to 15 carbon atoms. Y is a monocarboxylic acid residue with 1 to 20 carbon atoms. Z is a monoalcohol residue with 2 to 30 carbon atoms. p is X １ It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. q is X ２ It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. n represents the number of repetitions.

2. The electrode composite material according to claim 1, wherein the acid value of the polyester is in the range of 3 to 400 mgKOH / g.

3. The electrode composite material according to claim 1, wherein G is an aliphatic diol residue having a branched structure with 3 to 20 carbon atoms.

4. The electrode composite material according to claim 1, wherein A is an aliphatic dicarboxylic acid residue having 4 to 10 carbon atoms.

5. X １ and X ２ The electrode composite material according to claim 1, wherein each is independently an aliphatic dicarboxylic acid residue having 2 to 10 carbon atoms.

6. The electrode composite material according to claim 1, wherein the polyester is a polyester represented by the general formula (1-2) in which Z is an aliphatic monoalcohol residue having 2 to 30 carbon atoms.

7. The electrode composite material according to claim 1, wherein the number average molecular weight of the polyester is in the range of 1,500 to 5,000.

8. The electrode mixture according to claim 1, wherein the polyester is a liquid at room temperature.

9. The electrode composite material according to claim 1, wherein the electrode active material is one or more positive electrode active materials selected from lithium manganate, lithium cobaltate, lithium nickel manganese cobaltate, lithium nickel cobalt aluminate, lithium nickel cobaltate, lithium-containing olivine-type phosphate, titanium sulfide, molybdenum sulfide, iron sulfide, copper sulfide, nickel sulfide, niobium selenide, lithium iron phosphate, lithium manganese phosphate, lithium iron manganese phosphate, lithium cobalt phosphate, and lithium nickel phosphate.

10. The electrode composite material according to claim 1, wherein the electrode active material is one or more negative electrode active materials selected from lithium, indium, aluminum, silicon, tin, lithium oxide, indium oxide, aluminum oxide, silicon oxide, and tin oxide.

11. The electrode composite material according to claim 1, wherein the solid electrolyte is an oxide solid electrolyte containing lithium and oxygen and / or a sulfide solid electrolyte containing lithium and sulfur.

12. The electrode composite material according to claim 1, wherein the dispersant is contained in an amount of 0.05 to 10 parts by mass with respect to 100 parts by mass of the total of the electrode active material and the solid electrolyte.

13. A secondary battery using the electrode composite material according to any one of claims 1 to 12.

14. An all-solid-state battery having a positive electrode layer, a solid electrolyte layer, and a negative electrode layer in this order, An all-solid-state battery containing a dispersant in which one or more of the positive electrode layer, the solid electrolyte layer, and the negative electrode layer is a polyester represented by the following general formula (1-1) or (1-2). 【Chemistry 2】 (In the above general formulas (1-1) and (1-2), G is an aliphatic diol residue with 2 to 20 carbon atoms. A is an aliphatic dicarboxylic acid residue having 2 to 10 carbon atoms. X １ and X ２ Each of these is independently an aliphatic polybasic acid residue having 2 to 10 carbon atoms or an aromatic polybasic acid residue having 6 to 15 carbon atoms. Y is a monocarboxylic acid residue with 1 to 20 carbon atoms. Z is a monoalcohol residue with 2 to 30 carbon atoms. p is an integer obtained by subtracting one from the number of basic acid functional groups of an aliphatic polybasic acid residue or an aromatic polybasic acid residue of X １ and is an integer obtained by subtracting one from the number of basic acid functional groups of an aliphatic polybasic acid residue or an aromatic polybasic acid residue of q is X ２ It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. n represents the number of repetitions.

15. A secondary battery having a positive electrode, a separator, and a negative electrode in this order, The separator is a laminate in which the surface of the substrate is covered with a coating layer containing inorganic particles. A secondary battery containing a dispersant in which one or more of the positive electrode, the coating layer, and the negative electrode is a polyester represented by the following general formula (1-1) or (1-2). 【Transformation 3】 (In the above general formulas (1-1) and (1-2), G is an aliphatic diol residue with 2 to 20 carbon atoms. A is an aliphatic dicarboxylic acid residue having 2 to 10 carbon atoms. X １ and X ２ Each of these is independently an aliphatic polybasic acid residue having 2 to 10 carbon atoms or an aromatic polybasic acid residue having 6 to 15 carbon atoms. Y is a monocarboxylic acid residue with 1 to 20 carbon atoms. Z is a monoalcohol residue with 2 to 30 carbon atoms. p is X １ It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. q is X ２ It is an integer obtained by subtracting one from the number of basic acid functional groups of the aliphatic polybasic acid residue or aromatic polybasic acid residue. n represents the number of repetitions.

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