Battery

Abstract

A battery provided with a positive electrode layer, a negative electrode layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer, the electrolyte layer containing a polymer having the ability to preferentially conduct metal ions, and the ratio of the thickness of the positive electrode layer to the thickness of the electrolyte layer being 10: 1 to 0.5: 1.

Description

Technical Field

[0001] The present disclosure relates to a battery. Background Art

[0002] Batteries such as lithium-ion batteries that charge and discharge with the movement of metal ions between the positive electrode and the negative electrode have been actively studied because of their high capacity. As electrolytes for lithium-ion batteries and the like, solutions containing lithium salts in organic solvents or ionic liquids are known, but research on solid electrolytes or polymer electrolytes has also been conducted from the viewpoints of safety and processability (Patent Documents 1 to 3).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Chinese Patent Application Specification No. 110247111

[0006] Patent Document 2: Korean Patent No. 10-2094466

[0007] Patent Document 3: Chinese Patent Application Specification No. 112397762 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, regarding solid-state batteries using polymer electrolytes, there is still room for improvement in the cycle characteristics.

[0010] The present disclosure has been made in view of the above problems, and an object thereof is to provide a battery having excellent cycle characteristics.

[0011] Means for Solving the Problems

[0012] The present disclosure includes the following embodiments [1] to [8].

[0013] [1] A battery,

[0014] which includes a positive electrode layer, a negative electrode layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer,

[0015] wherein the electrolyte layer contains a polymer having the ability to preferentially conduct metal ions,

[0016] and the ratio of the thickness of the positive electrode layer to the thickness of the electrolyte layer is 10:1 to 0.5:1.

[0017] [2] A battery,

[0018] which includes a positive electrode layer, a negative electrode layer, and an electrolyte layer,

[0019] The above electrolyte layer contains a polymer having the ability to preferentially conduct metal ions.

[0020] The ratio of the thickness of the above negative electrode layer to the above electrolyte layer is 5:1 to 0.5:1.

[0021] [3] The battery according to [1] or [2], wherein

[0022] The above polymer has at least one of an anionic functional group having an alkali metal ion as a counter cation and a functional group having an anion capturing ability.

[0023] [4] The battery according to any one of claims [1] to [3], wherein

[0024] The above positive electrode layer contains a nickel-containing lithium composite oxide as a positive electrode active material.

[0025] [5] The battery according to any one of [1] to [4], wherein

[0026] The above negative electrode layer contains at least one selected from the group consisting of an oxide containing titanium, an active material containing silicon, and a carbon material as a negative electrode active material.

[0027] [6] The battery according to any one of [1] to [5], wherein

[0028] The above electrolyte layer contains an ionic liquid.

[0029] [7] The battery according to any one of [1] to [6], wherein

[0030] The peel strength between the above positive electrode layer and the above electrolyte layer is 1 N / m or more.

[0031] [8] The battery according to any one of [1] to [7], wherein

[0032] The peel strength between the above negative electrode layer and the above electrolyte layer is 1 N / m or more.

[0033] [9] A composite film

[0034] which comprises a fibrous substrate or a porous substrate and a polymer having the ability to preferentially conduct metal ions.

[0035] Advantageous Effects of the Invention

[0036] According to the present disclosure, a battery having excellent cycle characteristics can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a graph showing the results of charge and discharge tests performed on the half-cell of Example 1.

[0038] Figure 2 This is a graph showing the results of charge-discharge tests on the half-cell of Example 2.

[0039] Figure 3 This is a graph showing the results of charge-discharge tests on the half-cell of Comparative Example 1.

[0040] Figure 4 This is a graph showing the results of charge-discharge tests on the full cell.

[0041] Figure 5 This is a graph showing the results of charge-discharge tests on the half-cell of Example 3. Detailed implementation mode

[0042] The battery of this implementation mode includes a positive electrode layer, a negative electrode layer, and an electrolyte layer. The electrolyte layer contains a polymer having the ability to preferentially conduct metal ions and satisfies at least one of the following (1) and (2).

[0043] (1) The thickness ratio of the positive electrode layer to the electrolyte layer ((thickness of the positive electrode layer):(thickness of the electrolyte layer)) is 10:1 to 0.5:1.

[0044] (2) The thickness ratio of the negative electrode layer to the electrolyte layer ((thickness of the negative electrode layer):(thickness of the electrolyte layer)) is 5:1 to 0.5:1.

[0045] Regarding (1), the thickness ratio can be 5:1 to 0.5:1, can be 3:1 to 0.5:1, can be 1:1 to 0.6:1. The thickness of the positive electrode layer can be 1 to 500 μm, can be 1 to 200 μm, can be 10 to 150 μm, can be 20 to 100 μm. The thickness of the negative electrode layer can be 1 to 500 μm, can be 1 to 200 μm, can be 10 to 150 μm, can be 20 to 100 μm.

[0046] Regarding (2), the thickness ratio can be 3:1 to 0.5:1, can be 1:1 to 0.6:1.

[0047] The electrolyte layer can be a layer formed from an electrolyte composition. The electrolyte layer and the electrolyte composition can contain a solid electrolyte material while containing a polymer having the ability to preferentially conduct metal ions.

[0048] The thickness of the electrolyte layer can be 1 to 200 μm, can be 10 to 150 μm, can be 20 to 100 μm.

[0049] [Polymer having the ability to preferentially conduct metal ions]

[0050] As a polymer having the ability to preferentially conduct metal ions (hereinafter also simply referred to as a polymer), for example, it can be a polymer in which the transference number of metal ions is 0.45 or more, 0.5 or more, 0.6 or more, or 0.7 or more when measuring the transference number of metal ions in at least one of the following compositions (A) and (B) at room temperature (25 °C).

[0051] (A) A composition containing 17% by mass of the polymer, 17% by mass of polyvinylidene fluoride (PVDF), and 66% by mass of a nonionic plasticizer.

[0052] (B) A composition containing 31.9% by mass of the polymer, the total amount of the remaining metal salt and nonionic plasticizer, and having a metal ion concentration of 0.3 mol / L.

[0053] When the polymer has an anionic functional group, the metal ions contained in the composition can be counter cations of the anionic functional group or metal ions added as a metal salt. The polymer having the ability to preferentially conduct metal ions can be a polymer having the ability to preferentially conduct alkali metal ions. As the nonionic plasticizer, organic solvents can be cited in composition (A), and at least one of other resins such as organic solvents and fluororesins can be cited in composition (B). The organic solvent can be an aprotic solvent. The aprotic solvent can be at least one selected from the group consisting of carbonate solvents, fluorinated solvents, and ether solvents. As the fluororesin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be a carbon chain formed by radical polymerization of an ethylenically unsaturated group.

[0054] As the carbonate solvent, chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate can be cited; cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate can be cited. As the ether solvent, cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, and 1,3-dioxolane can be cited; chain ethers such as 1,2-diethoxyethane and ethoxymethoxyethane can be cited. As the fluorinated solvent, hydrofluorocarbons such as perfluorooctane can be cited; hydrofluoroethers such as methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether, and hydrofluoroolefins such as 1,3,3,3-tetrafluoropropene can be cited. In addition, as the solvent, aprotic solvents such as dimethyl sulfoxide (DMSO); amide solvents such as dimethylformamide (DMF) and dimethylacetamide (DMA) can be cited. The organic solvent can be used alone or as a mixed solvent containing two or more organic solvents. The organic solvent can be a mixed solvent of ethylene carbonate:propylene carbonate = 1:1 (volume ratio).

[0055] The concentration of metal ions in the composition can be prepared by adding metal salts. For example, when the metal salt is an alkali metal salt, there is no particular limitation on the alkali metal salt. However, when the alkali metal is designated as M, examples include MF, MCl, MBr, MI, MClO 4 , MPF 6 , MBF 4 , M 2 SO 4 , M[(C h F 2h+1 )SO 3 (h is from 0 to 3), M[(C h F 2h+1 )SO 2 2 N (h is from 0 to 3), etc. When the polymer has the structural unit (A) described below, M can be the same alkali metal element as the alkali metal element contained in the structural unit (A).

[0056] Examples of the polymer having the ability to preferentially conduct metal ions include polymers containing at least one of an anionic functional group having an alkali metal ion as a counter cation (also referred to as functional group (A).) and a functional group having an anion capture ability (also referred to as functional group (B).). There is no particular limitation on the structure of the polymer, but examples include a structure having a carbon chain as the main chain, and the carbon chain can be a carbon chain formed by radical addition polymerization of a monomer having an ethylenically unsaturated group.

[0057] Examples of the alkali metal ion as the counter cation of functional group (A) include lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion, etc. It can be a lithium ion, a sodium ion, or a potassium ion, it can be a lithium ion or a sodium ion, and it can be a lithium ion. Hereinafter, the structural unit containing functional group (A) and the metal ion as the counter cation of functional group (A) is also referred to as structural unit (A). Structural unit (A) can have a structure obtained by radical addition polymerization of a monomer having an ethylenically unsaturated group. The alkali metal ion as the counter cation of functional group (A) can contain the same alkali metal ion as the alkali metal ion contained in the positive electrode active material.

[0058] Structural unit (A) can have at least one selected from the group consisting of a conjugated anion of a sulfonylimide group, a conjugated anion of a sulfonic acid group, a conjugated anion of a carboxylic acid group, and a conjugated anion of a phenolic hydroxyl group as functional group (A). The conjugated anion of a sulfonylimide group, the conjugated anion of a sulfonic acid group, and the conjugated anion of a phenolic hydroxyl group can be contained, for example, in the groups having a conjugated anion of a sulfonylimide group, the groups having a conjugated anion of a sulfonic acid group (sulfonate group), and the groups having a conjugated anion of a phenolic hydroxyl group described below. ​

[0059] When the functional group (A) is a group of a conjugated anion having a sulfonylimide group, the structural unit (A) may be a structural unit represented by the following formula (A1).

[0060] [Chemical formula 1]

[0061]

[0062] (In formula (A1), X is a divalent organic group having 1 to 20 carbon atoms, Y is a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, M + is an alkali metal ion, and * represents the position where the structural unit (A1) is bonded to other structural units.)

[0063] There is no particular limitation on X. It may be a hydrocarbon group, a group having a heteroatom, or may have a heterocycle. More specifically, examples of X include divalent groups such as a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-. It should be noted that when there are a plurality of linking groups, the linking groups are not adjacent to each other. In addition, the above divalent group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. As the substituent, a monovalent substituent can be mentioned, for example, a halogen atom. There is no particular limitation on the above hydrocarbon group, and it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any of a saturated hydrocarbon group and an unsaturated hydrocarbon group. X may be bonded to one or both of the nitrogen atom of the maleimide group and the sulfur atom of the sulfonyl group through a carbon atom possessed by X.

[0064] The number of carbon atoms possessed by X may be 1 to 15, may be 2 to 10, or may be 3 to 8. X may be a group having an aromatic ring, or may be a group having an aromatic carbocyclic ring such as a benzene ring. Substituents such as an alkyl group, a halogen atom, and an electron-withdrawing group may also be bonded to a carbon atom that is a ring member of the carbocyclic ring. The hydrocarbon group of X is preferably a phenylene group, an alkylene group having 1 to 8 carbon atoms, a polyoxyalkylene group, or a group obtained by substituting a part or all of the hydrogen atoms bonded to the carbon atoms they possess with a halogen atom such as a fluorine atom, and more preferably a phenylene group or a substituted phenylene group substituted with an alkyl group, a halogen atom, an electron-withdrawing group, etc. As the electron-withdrawing group, a halogen atom, a sulfonic acid group or its salt, a sulfonic acid ester, a nitro group, a nitrile group, etc. can be mentioned.

[0065] In formula (A1), when Y is a monovalent organic group, there is no particular limitation on this organic group, and it may be a hydrocarbon group, a group having a heteroatom, or may have a heterocycle. More specifically, examples of Y include monovalent groups such as a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-. It should be noted that when there are multiple linking groups, the linking groups are not adjacent to each other. In addition, the above monovalent group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. As the substituent, it may be a monovalent substituent, and examples thereof include a halogen atom. There is no particular limitation on the above hydrocarbon group, and it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0066] The number of carbon atoms that Y has may be 1 to 15, may be 1 to 10, may be 1 to 8, may be 1 to 5, or may be 1 to 3. The hydrocarbon group of Y is preferably a phenyl group, an alkyl group having 1 to 5 carbon atoms, or a group obtained by substituting a part or all of the hydrogen atoms bonded to the carbon atoms of these groups with a halogen atom such as a fluorine atom, more preferably a fluoroalkyl group having 1 to 5 carbon atoms, and further preferably a fluoroalkyl group having 1 to 3 carbon atoms such as a trifluoromethyl group. The fluoroalkyl group may be a perfluoroalkyl group. When Y is a halogen atom, as the halogen atom, it is preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom.

[0067] In formula (A1), M + is preferably a lithium ion (Li + ), a sodium ion (Na + ), or a potassium ion (K + ), and more preferably a lithium ion. M + may also contain two or three kinds of ions among Li + , Na + , and K + , but preferably contains substantially only a single ion.

[0068] The group having a conjugated anion with a sulfonic acid group is a group having a group obtained by replacing the hydrogen atom of the sulfonic acid group with an alkali metal (that is, using M as the alkali metal, also called -SO 3 M group, an alkali metalated sulfonic acid group).

[0069] The group having a conjugated anion with a carboxylic acid group is a group having a group obtained by replacing the hydrogen atom of the carboxylic acid group with an alkali metal (that is, using M as the alkali metal, -COOM group, an alkali metalated carboxylic acid group).

[0070] The group of the conjugate anion having a phenolic hydroxyl group is a group having a hydroxyl group directly bonded to an aromatic ring (i.e., a phenolic hydroxyl group (-OH)) metallated with an alkali metal (i.e., an -OM group where M is an alkali metal).

[0071] The structural unit (A) may be a structural unit represented by the following formula (A2).

[0072] [Chemical formula 2]

[0073]

[0074] (In formula (A2), Y 2 is a group having a metallated sulfonimide group, a group having a metallated carboxyl group, a group having a metallated phenolic hydroxyl group, or a group having a metallated sulfonic acid group, and * represents the bonding position of the structural unit (A2) to other structural units. R 15 ~R 17 are each independently a hydrogen atom or a monovalent substituent, or R 16 is a hydrogen atom or a monovalent substituent, and R 15 and R 17 together form a divalent substituent.)

[0075] R 15 ~R 17 may be one or more hydrogen atoms, or may all be hydrogen atoms.

[0076] When R 15 ~R 17 are monovalent substituents, the monovalent substituent may also be a monovalent organic group. The number of carbon atoms in the organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3. Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and a monovalent substituent such as a group having a heterocycle. In addition, the above monovalent substituent may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, and a phenyl group.

[0077] Regarding R 15 ~R17 When the monovalent substituent can have an electron-withdrawing group or be an electron-withdrawing group itself. The electron-withdrawing group can also be bonded to the above-mentioned monovalent organic group, and the above-mentioned monovalent organic group can also be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate, a nitro group, a nitrile group, etc. As the halogen atom, it can be any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0078] In R 15 and R 17 When they together form a divalent organic group, the number of carbon atoms in the divalent organic group can be 1 to 20, can be 1 to 15, can be 1 to 10, can be 1 to 5, can be 1 to 3. Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-, and a divalent substituent such as a group having a heterocycle. In addition, the above-mentioned divalent organic group can also have a substituent that replaces a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom, etc. The above-mentioned hydrocarbon group is not particularly limited and can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group can be any one of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group can be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a propylene group, a butylene group, etc.

[0079] When Y 2 is a group having a phenolic hydroxyl group, Y 2 can be a group represented by any one of the following formulas (A21) to (A26).

[0080] [Chemical formula 3]

[0081]

[0082] (In formula (A21), at least one of the R A groups is -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which can be Li, Na or K. In formula (A22), at least one of the R B groups is -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which can be Li, Na or K. In formula (A23), at least one of the R C groups is -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which can be Li, Na or K. In formula (A24), at least one of the R DAt least one of the groups is an -OM group, and the remainder is a hydrogen atom or a monovalent substituent. M is an alkali metal element and can be Li, Na, or K. In formula (A25), R E At least one of the groups is an -OM group, and the remainder is a hydrogen atom or a monovalent substituent. M is an alkali metal element and can be Li, Na, or K. In formula (A26), R F At least one of the groups is an -OM group, and the remainder is a hydrogen atom or a monovalent substituent. M is an alkali metal element and can be Li, Na, or K.)

[0083] When the polymer has a functional group of formula (A21), in the benzene ring of formula (A21), when observed from the bonding site of the functional group of formula (A21) and the polymer, an -OM group can be bonded at the para position. When observed from the above bonding site, a hydrogen atom, an -OM group, a methyl group, an ethyl group, or a monovalent organic group having 1 to 20 carbon atoms can be independently bonded at the meta position or at the ortho and meta positions respectively (wherein, when the monovalent organic group is a saturated hydrocarbon group, it is a methyl group, an ethyl group, or a group having 6 to 20 or 6 to 15 carbon atoms, and when the monovalent organic group is an alkoxy group, it is a group having 4 to 20 or 4 to 15 carbon atoms).

[0084] The groups represented by formulas (A21) to (A26) can have 1 to 3 -OM groups, can have 1 or 2 -OM groups, and can have 1 -OM group.

[0085] In formulas (A21) to (A26), the monovalent substituent is preferably an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonic acid ester, a nitro group, a nitrile group, etc. As the halogen atom, it can be any one of F, Cl, Br, and I.

[0086] In addition, in formulas (A21) to (A26), the monovalent substituent may be an organic group having 1 to 20 carbon atoms. The number of carbon atoms in the organic group may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3. Examples of the organic group include a hydrocarbon group and a group having a heterocycle such as a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-. In addition, the above monovalent group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, and a phenyl group. It should be noted that the monovalent organic group may itself be an electron-withdrawing group.

[0087] In Y 2 is a group having a conjugate anion of sulfonic acid, as Y 2 , the groups represented by the following formula (A3) can be cited.

[0088] [Chemical formula 4]

[0089]

[0090] (In formula (A3), R 19 is a covalent bond or a divalent organic group. M is an alkali metal element and may be Li, Na, or K, or may be Li.)

[0091] In formula (A3), the number of carbon atoms in the divalent organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3. Examples of the organic group include a hydrocarbon group and a group having a heterocycle such as a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-. In addition, the above divalent organic group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methylene group and a phenylene group.

[0092] As the group having a conjugate anion of sulfonic acid, examples include -SO 3 M, -CH 2 -SO 3 M, -C 6 H 4 -SO 3 M, etc.

[0093] The functional group (B) is a functional group having a function as an anion receptor. An anion receptor refers to a chemical species that captures an anion by forming an electrostatic interaction, a hydrogen bond, an acid-base complex, etc. with the anion. The functional group (B) captures the counter anion of the metal ion in the metal salt and promotes the dissociation of the counter anion from the metal ion. As a result, the mobility of the metal ion increases. On the other hand, since the counter anion is captured by the polymer via the structural unit (B), the mobility of the counter anion decreases. It is considered that in the polymer having the functional group (B), as a result, the transference number of the metal ion increases. In addition, since the mobility of the metal ion increases, the polymer having the functional group (B) tends to have an increased metal ion conductivity.

[0094] Known are low-molecular chemical species (compounds, etc.) that function as anion receptors. As such compounds, for example, the compounds described in U.S. Patent No. 6022643, U.S. Patent No. 5705689, U.S. Patent No. 6120941, etc. can be cited. The functional group (B) has a structure corresponding to the chemical species that functions as an anion receptor. Since this functional group is fixed in the polymer, it is considered that, unlike conventional low-molecular anion receptors, it can fix the captured anion to the polymer structure and can more effectively suppress the participation in current caused by the movement of this anion.

[0095] It should be noted that the counter anion of the alkali metal salt does not necessarily have to be a free anion that is completely ionized when captured by the above functional group, and can be captured by interacting with the above functional group in a state of forming an ionic bond or an ion pair with the metal ion.

[0096] The functional group having a function as an anion receptor can be a functional group having Lewis acidity. In this case, the above functional group can capture an anion by accepting the non-bonding electron pair of the anion and forming an acid-base complex. As such a functional group, a functional group having an electron-deficient atom can be cited. It should be noted that an electron-deficient atom refers to an atom that is covalently bonded to other atoms but the outermost shell electrons of this atom do not form an octet. As an electron-deficient atom, an atom belonging to Group 13 of the periodic table can be cited. More specifically, it can be at least one of aluminum and boron, and can be boron.

[0097] In addition, as a functional group having a function as an anion receptor, a group having a heteroether moiety may also be used. A group having a heteroether moiety is a group having a heteroether compound as a substituent, and the heteroether compound is a compound obtained by substituting -O- of an ether compound with -NR E -(wherein, R E is a hydrogen atom or an organic group). The heteroether moiety may be either a chain heteroether moiety or a cyclic heteroether moiety, and may have both a chain heteroether moiety and a cyclic heteroether moiety. The group having a heteroether moiety may also have an electron-withdrawing group on a hydrocarbon moiety or the like, for example.

[0098] Hereinafter, the structural unit containing the functional group (B) will also be referred to as the structural unit (B). The functional group (B) may be contained in the structural unit represented by the following formula (B), for example.

[0099] [Chemical formula 5]

[0100]

[0101] (In the formula (B), W is a functional group having a function as an anion receptor, and R 1 to R 3 are each independently a hydrogen atom or a monovalent substituent, or R 3 is a hydrogen atom or a monovalent substituent, and R 1 and R 2 together form a divalent organic group. * indicates the position where the structural unit (B) is bonded to other structural units.)

[0102] The polymer having the ability to preferentially conduct metal ions may contain one or two or more structural units represented by the formula (B).

[0103] One or more of R 1 to R 3 may be a hydrogen atom, or all may be hydrogen atoms. W may be a group represented by the following formula (B1).

[0104] Among R 1 to R 3In the case of a monovalent substituent, the monovalent substituent may also be a monovalent organic group. The number of carbon atoms in the organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3. Examples of the organic group include a hydrocarbon group, a group having a heterocycle such as a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-, and other monovalent substituents. In addition, the above monovalent substituent may also have a substituent that substitutes a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a phenyl group, etc.

[0105] It should be noted that in this specification, an aromatic hydrocarbon group is a group containing an aromatic part and may also have an aliphatic part. In addition, in this specification, a cyclic hydrocarbon group is a group containing a cyclic hydrocarbon part and may also contain a linear or branched hydrocarbon part.

[0106] The monovalent substituent may have an electron-withdrawing group or may be an electron-withdrawing group itself. The electron-withdrawing group may also be bonded to the above monovalent organic group, and the above monovalent organic group may also be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate ester, a nitro group, a nitrile group, etc. The halogen atom may be any of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0107] In R 1 and R 2 When they together form a divalent organic group, the number of carbon atoms in the divalent organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3. Examples of the organic group include a hydrocarbon group, a group having a heterocycle such as a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-, and other divalent substituents. In addition, the above divalent organic group may also have a substituent that substitutes a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a propylene group, a butylene group, etc.

[0108] W preferably has a group represented by the following formula (B1).

[0109] [Chemical formula 6]

[0110]

[0111] (In formula (B1), W B is an atom belonging to Group 13 of the periodic table, and R 5 is a covalent bond or a divalent organic group, and R 6 and R 7 are a hydrogen atom, an -OH group, a halogen atom, or a monovalent organic group, or together form a divalent organic group. R 6 and R 7 may be the same group or different groups.)

[0112] W B may be at least one of aluminum and boron, and may be boron.

[0113] When R 5 is a divalent organic group, the number of carbon atoms in the divalent organic group may be 1 to 20, may be 1 to 15, may be 1 to 10, may be 1 to 5, or may be 1 to 3. Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and a monovalent substituent such as a group having a heterocycle. In addition, the above divalent organic group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. The substituent may be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate ester, a nitro group, and a nitrile group. As the halogen atom, any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom may be used. R 5 may be a hydrocarbon group, a halogen-substituted hydrocarbon group, or a group in which a hydrocarbon group or a halogen-substituted hydrocarbon group is bonded to W B via an ether bond. The halogen-substituted hydrocarbon group may be a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group with halogen atoms, and may be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group. R 5 may also be a covalent bond.

[0114] When R 6 or R 7 is a halogen atom, it may be any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom.

[0115] When R 6 or R 7When the monovalent organic group is a monovalent organic group, the number of carbon atoms in the monovalent organic group can be 1 to 20, can be 1 to 15, can be 1 to 10, can be 1 to 5, or can be 1 to 3. Examples of the organic group include a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are replaced by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and a monovalent substituent such as a group having a heterocycle. In addition, the above monovalent organic group may also have a substituent that replaces a hydrogen atom bonded to a carbon atom. The substituent may be an electron-withdrawing group. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonate ester, a nitro group, a nitrile group, etc. As the halogen atom, any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom may be used. R 6 or R 7 can be a hydrocarbon group, a halogen-substituted hydrocarbon group, or a group in which a hydrocarbon group or a halogen-substituted hydrocarbon group is bonded to W B via an ether bond. The halogen-substituted hydrocarbon group can be a group obtained by substituting part or all of the hydrogen atoms in the hydrocarbon group with halogen atoms, and can be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group.

[0116] W can be a group represented by the following formula (B1a) or a group represented by the following formula (B1b).

[0117] [Chemical formula 7]

[0118]

[0119] (In formula (B1a), X 1 and X 2 are each an oxygen atom (ether bond) or a covalent bond, R 11 and R 12 are each a halogen atom, a monovalent hydrocarbon group, a hydrogen atom, or a monovalent halogen-substituted hydrocarbon group, and can be a halogen atom (except when X is an oxygen atom), a monovalent hydrocarbon group, or a monovalent halogen-substituted hydrocarbon group. At least one of R 11 and R 12 can be a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group. R 11 and R 12 can be the same group or different groups.)

[0120] [Chemical formula 8]

[0121]

[0122] (In formula (B1b), X 3 and X 4 are each an oxygen atom (ether bond) or a covalent bond, R 13is a divalent hydrocarbon group or a divalent halogen-substituted hydrocarbon group.)

[0123] In formula (B1a), when R 11 is a halogen atom, X 1 can be a covalent bond. When R 12 is a halogen atom, X 2 can be a covalent bond. When R 11 or R 12 is a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group, the number of carbon atoms in the monovalent hydrocarbon group or the monovalent halogen-substituted hydrocarbon group can be 1 to 20, can be 1 to 15, can be 1 to 10, can be 1 to 5, can be 1 to 3. The halogen-substituted hydrocarbon group can be a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group with halogen atoms, and can be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group.

[0124] R 11 and R 12 are each independently -F, -CH 3 , -C 2 H 5 , -C 3 H 7 , -C 6 H 5 (phenyl), -C 6 H n F 5-n (n is an integer from 0 to 4, can be an integer from 0 to 3.), -CF 3 , -CH 2 CF 3 , -CH 2 CF 3 CF 7 , -CH(CF 3 ) 2 , -C(CF 3 ) 2 -C 6 H 5 , -C(CF 3 ) 3 , -C 6 H n (CF 3 ) 5-n (n is an integer from 0 to 4, can be 1 or 2.)

[0125] In formula (B1b), the divalent hydrocarbon group or the divalent halogen-substituted hydrocarbon group may have 1 to 20 carbon atoms, may have 1 to 15 carbon atoms, may have 2 to 10 carbon atoms, or may have 3 to 8 carbon atoms. The halogen-substituted hydrocarbon group may be a group obtained by substituting part or all of the hydrogen atoms of the hydrocarbon group with halogen atoms, and may be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group.

[0126] R 13 Examples include -C 2 H 4 -, -C 3 H 6 -, -C 4 H 8 -, -C 5 H 10 -, -C 6 H 12 -, -C 7 H 14 -, -C 8 H 16 -, -C 9 H 18 -, -C 10 H 20 -, etc., and groups obtained by partially or fully substituting their hydrogen atoms with fluorine, etc. More specifically, -C(CH 3 ) 2 -C(CH 3 ) 2 - is preferred.

[0127] The molar ratio m of the structural unit (B) contained in the polymer to all the structural units may be 0.2 to 0.8, may be 0.25 to 0.75, may be 0.3 to 0.7, may be 0.35 to 0.65, or may be 0.4 to 0.6.

[0128] The molar ratio n of the structural unit (A) contained in the polymer to all the structural units may be 0.25 to 0.75, may be 0.3 to 0.7, may be 0.35 to 0.65, or may be 0.4 to 0.6.

[0129] As long as the sum of m and n is 1 or less, there is no problem, but it may also be 0.95 or less. In addition, the sum of m and n may be 0.5 or more, may be 0.6 or more, may be 0.7 or more, may be 0.8 or more, may be 0.9 or more, or may be 0.95 or more.

[0130] The content of the structural unit (A) relative to the total mass of the polymer may be 5 to 90% by mass, may be 20 to 80% by mass, may be 40 to 75% by mass, or may be 55 to 70% by mass.

[0131] The content of the structural unit (B) relative to the total mass of the polymer may be 10 to 95% by mass, may be 15 to 95% by mass, may be 20 to 95% by mass, may be 20 to 80% by mass, may be 25 to 60% by mass, may be 30 to 45% by mass.

[0132] The total content of the structural unit (A) and the structural unit (B) relative to the total mass of the polymer may be 50% by mass or more, may be 70% by mass or more, may be 90% by mass or more, may be 95% by mass or more.

[0133] The polymer may contain a structural unit (C) that is different from either the structural unit (A) or the structural unit (B). Examples of the structural unit (C) include the structural unit represented by the following structural unit (C1), the structural unit represented by the structural unit (C2), and the like.

[0134] [Chemical formula 9]

[0135]

[0136] (In formula (C1), R 21 ~R 24 are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. * represents the position where the structural unit (C1) is bonded to other structural units.)

[0137] [Chemical formula 10]

[0138]

[0139] (In formula (C2), R 25 is a divalent organic group having 1 to 20 carbon atoms, and R 26 and R 27 are each a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. R 25 may form a ring having an ethylene unit and an imide group of formula (C2) (succinimide ring or its N-derivative), or a ring having an anhydride group (succinic anhydride ring).)

[0140] R 21 ~R 24 One or more of them may be a monovalent organic group. The monovalent organic group may be a group represented by -Z 1 -R 29 The number of carbon atoms each of R 21 ~R 24 may have may be 1 to 40, may be 1 to 20, may be 2 to 15, may be 4 to 13. Among them, Z1 is a divalent linking group, which can be, for example, a covalent bond, -O-, -S-, -C(=O)-, -C(=O)O-, -OC(=O)-, -C(=O)NR 38 -, or -NR 39 group represented by -C(=O)-. When Z 1 is a covalent bond, -O-, -S-, -C(=O)-, -C(=O)O- or -OC(=O)-, R 29 is a hydrogen atom or a monovalent organic group. When Z is -C(=O)NR 38 -, R 29 , R 38 are each independently a hydrogen atom or a monovalent organic group, or R 29 and R 38 together form a ring. When it is -NR 39 C(=O)-, R 29 , and R 39 are each independently a hydrogen atom or a monovalent organic group, or R 29 and R 39 together form a ring. As the monovalent organic group of R 29 , R 38 and R 39 , it can have 1 to 20, or 1 to 10 organic groups. When R 38 is a monovalent organic group, it can be a monovalent hydrocarbon group having 1 to 20 carbon atoms. When Z1 is a covalent bond or -C(=O)O-, R 29 can be a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. When Z1 is a covalent bond and R 29 is a hydrocarbon group, the hydrocarbon group can be an aliphatic hydrocarbon group. In addition, R 29 can be a monovalent organic group other than a hydrocarbon group or a hydrocarbon group having a ring structure. When Z 1 is -O-, and W is set as an alkyl ether, it can be a monovalent organic group other than the group represented by W-H. When R 26 to R 28 are monovalent organic groups, as the monovalent organic group, the same monovalent organic groups as those listed in the examples of R 25 can be cited.

[0141] In addition, in the structural unit (C), a structural unit that is a precursor of the structural unit (A) (also referred to as the structural unit (Ap)) may be included. Examples of such a structural unit include unreacted structural units and intermediate structural units in the structural unit that is a precursor of the structural unit (A) (for example, a structural unit derived from the monomer (A2') described later) that cannot be converted into the structural unit (A). For example, a group that is a conjugate acid of the structural unit (A) (that is, a group obtained by replacing the alkali metal ion that is the counter cation of the structural unit (A) with H + and a group obtained by replacing the counter cation of the structural unit (A) with a cation other than an alkali metal ion, etc. Examples of the counter cation contained in the structural unit (Ap) include NH 4 + , organic ammonium cations, metal ions such as alkaline earth metal ions, etc. The polymer may also contain 85 mol% or more, 90 mol% or more, or 95 mol% or more of the structural unit (A) relative to the total amount of the structural unit (A) and the structural unit (Ap).

[0142] The polymer may also contain a structural unit derived from a hydrocarbon compound having a plurality of ethylenically unsaturated groups such as butadiene and isoprene.

[0143] The polymer may also have a structural unit derived from a crosslinking agent. Examples of the crosslinking agent include compounds having a plurality of ethylenically unsaturated groups in the molecule such as hexanediol diacrylate, pentaerythritol tetraacrylate, divinylbenzene, and triethylene glycol divinyl ether.

[0144] The number average molecular weight (Mn) of the polymer may be 5,000 to 200,000, may be 8,000 to 120,000, and may be 10,000 to 100,000. The weight average molecular weight (Mw) of the polymer may be 5,000 to 300,000, may be 10,000 to 250,000, and may be 20,000 to 100,000. The molecular weight distribution (Mw / Mn) of the polymer may be 1.0 to 3.5, and may be 1.3 to 2.7. The number average molecular weight and the weight average molecular weight of the polymer can be measured, for example, by gel permeation chromatography.

[0145] The content of the polymer in the electrolyte composition (electrolyte layer) may be 75% by mass or less, may be 0.5 to 60% by mass, and may be 1 to 45% by mass relative to the total amount of the electrolyte composition (electrolyte layer).

[0146] The electrolyte composition may also contain an alkali metal salt. This is particularly effective when the polymer contains the functional group (B). The alkali metal salt is not particularly limited, but when the alkali metal is M, MF, MCl, MBr, MI, MClO 4, MPF 6 , MBF 4 , M 2 SO 4 , M[(C h F 2h+1 )SO 3 (h is from 0 to 3), M[(C h F 2h+1 )SO 2 2 N (h is from 0 to 3), etc. M can be the same alkali metal element as the alkali metal element contained in the structural unit (A). M can be the same alkali metal element as the alkali metal element contained in the solid electrolyte material. M can be lithium, sodium or potassium.

[0147] As a method for producing the polymer, there is no particular limitation. For example, a method of polymerizing at least one monomer (monomer mixture) of a monomer containing an anionic functional group ionized by an alkali metal ion or a monomer having a precursor of the anionic functional group (hereinafter referred to as monomer (A')) and a monomer (B') containing a functional group having a function as an anion acceptor can be mentioned. The monomer may further contain a monomer (C') different from the monomer (A') and the monomer (B').

[0148] The monomer (A') and the monomer (B') may have an ethylenically unsaturated group. In this case, the monomer (A') and the monomer (B') can be polymerized by radical addition polymerization. In this case, the monomer can be polymerized in the presence of an initiator. That is, the polymerization reaction can be carried out in a polymerizable composition containing the monomer and the initiator.

[0149] The monomer (A') is a monomer that derives the structural unit (A) in the polymer. As the monomer (A'), the monomer (A1') represented by the following formula (A1'), the monomer (A2') represented by the formula (A2'), etc. can be mentioned.

[0150] [Chemical formula 11]

[0151]

[0152] (In the formula (A1'), X, Y and M + have the same meaning as in the formula (A).)

[0153] [Chemical formula 12]

[0154]

[0155] (In the formula (A2'), R 15 ~R 17 have the same meaning as R 15 ~R 17 ​the same meaning, and Y2’ is a group capable of derivatizing a phenolic hydroxyl group corresponding to the -OM group in formula (A2), a group having a group capable of derivatizing a sulfonic acid group corresponding to the -SO 2 M group, a group capable of derivatizing a group having an alkali metalated sulfonylimide group possessed by Y 2 or a group capable of derivatizing a group having an alkali metalated carboxylic acid possessed by Y 3 ). 2 Y 2 ’ may also be the same group as Y

[0156] but may be a group that is a precursor of Y 2 . That is, Y 2 ’ is a group having a group capable of being converted into an -OM group or an -SO 2 M group at the same position as the -OM group or -SO 2 M group possessed by the desired Y 2 . 3 As a group capable of derivatizing a phenolic hydroxyl group corresponding to the -OM group possessed by Y 3 , for example, a hydrolyzable group can be cited. By hydrolyzing this hydrolyzable group, a phenolic hydroxyl group can be introduced at the position corresponding to the -OM group possessed by Y

[0157] . As the hydrolyzable group, for example, an alkoxide group or an -OSi(R 2 ) 2 group (R k is a monovalent organic group such as a hydrocarbon group) can be cited. The phenolic hydroxyl group can be converted into an -OM group, for example, by reacting with an alkaline salt of an alkali metal such as MOH, M 3 CO k , MHCO 2 CO 3 , MHCO 3 .

[0158] Similarly, as a group capable of derivatizing a sulfonic acid group corresponding to the -SO 2 M group possessed by Y 3 , for example, a group capable of derivatizing a sulfonic acid group such as a sulfonate group, -SO 2 Cl group (-SO 3 H) can be cited. The sulfonic acid group can be converted into an -OM group, for example, by reacting with a salt of an alkali metal such as MOH, M 2 CO 3 , MHCO 3 , an alkali metal halide, etc. In addition, for the -SO 2 Cl group, it can also be reacted with MOH to be converted into an -SO 3 M group. When an excessive amount of MOH is used, most of the -SO2 The Cl group is converted to -SO 3 M group. In the said reaction, there is also -SO 2 A part of the Cl group becomes -SO 3 In the case of the H group, but regarding -SO 3 For the H group, it can also be reacted with a base containing M separately to form -SO 3 M group. In addition, Y 2 ’ can also be a group having the same anionic part as Y 2 and forming a salt with a cation other than an alkali metal ion. In this case, by subjecting the obtained polymer to a cation exchange reaction, the structural unit (A2) can be derived. The reaction rate of Y2’ (the proportion of Y 2 ’ that is converted to Y 2 in the total amount of Y 2 ’) can be 85 mol% or more, 90 mol% or more, or 95 mol% or more.

[0159] Examples of the group capable of deriving an alkali-metalated sulfonylimide group include a group having an alkali-metalated sulfonylimide group or a group having a group as its conjugate acid. Examples of the group capable of deriving a group having an alkali-metalated carboxylic acid can be a group having a carboxyl group (-COOH) or its salt. When the monomer (A2’) has a group capable of deriving a group having an alkali-metalated carboxylic acid, the monomer (A2’) can be an unsaturated fatty acid or its salt. The unsaturated fatty acid can have one or more carboxyl groups or their salts.

[0160] The monomer (B') is a monomer that derives the structural unit (B) in the polymer. Examples of the monomer (B’) include the monomer (B’) represented by the following formula (B’).

[0161] [Chemical formula 13]

[0162]

[0163] (In the formula, R 1 ~R 3 and W have the same meanings as R 1 ~R 3 and W in the formula (B).)

[0164] The radical polymerization initiator can be either a thermal initiator or a photoinitiator. For example, as thermal initiators, azo initiators such as 2,2-azobis(isobutyronitrile) (AIBN); 2,2-azobis(2-methylbutyronitrile) (AMBN), 2,2-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1-azobis(1-cyclohexanecarbonitrile) (ACHN, V-40), dimethyl-2,2-azobisisobutyrate (MAIB), etc. can be cited; organic peroxides such as benzoyl peroxide, bis(2-ethylhexanoyl) peroxide, dilauroyl peroxide, didecanoyl peroxide, bis(2,4-dichlorobenzoyl) peroxide, etc. can be cited. As photoinitiators, oxime compounds, metallocene compounds, acylphosphine compounds, aminophenone compounds, etc. can be cited. One or more than two kinds of initiators can be used.

[0165] The electrolyte layer (electrolyte composition) can contain a polymer electrolyte, a binder resin, an organic solvent, an ionic liquid, etc. as required.

[0166] The binder resin contained in the electrolyte layer is not particularly limited, but fluorine-based resins, synthetic rubbers, etc. can be cited. As the fluorine-based resin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be a carbon chain formed by radical polymerization of an ethylenically unsaturated group. As the fluororesin, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyvinylidene fluoride (PVDF), etc. can be cited. As the synthetic rubber, SBR (styrene-butadiene rubber), etc. can be cited. The content of the binder resin in the electrolyte layer (electrolyte composition) can be 0.5 to 40% by mass, and can be 1 to 30% by mass.

[0167] As the organic solvent, the above-mentioned organic solvents can be cited, a carbonate-based solvent can be included, and a mixed solvent containing two or more kinds of carbonate-based solvents can be used. The content of the organic solvent in the electrolyte layer (electrolyte composition) can be 10 to 90% by mass, can be 30 to 80% by mass, and can be 50 to 75% by mass. In the electrolyte composition or the electrolyte, the polymer can be swollen by the organic solvent. The content of the organic solvent in the electrolyte composition or the electrolyte can be 10 to 500 parts by mass, can be 30 to 400 parts by mass, and can be 50 to 300 parts by mass with respect to the total 100 parts by mass of the polymer having the ability to preferentially conduct metal ions and other resins (resins other than the polymer having the ability to preferentially conduct metal ions).

[0168] The electrolyte composition may also contain a solid electrolyte material. As the solid electrolyte material, there is no particular limitation, and it may be an oxide (oxide-based solid electrolyte), a sulfide (sulfide-based solid electrolyte), a hydride (hydride-based solid electrolyte), a halide (halide-based solid electrolyte), or the like. The solid electrolyte material may contain at least one of an alkali metal element and an alkaline earth metal element, and may contain an alkali metal element.

[0169] (Oxide-based solid electrolyte)

[0170] As the oxide-based solid electrolyte, for example, perovskite-type oxides, NASICON-type oxides, LISICON-type oxides, garnet-type oxides, and the like, and substances obtained by doping other cations or anions in the oxide can be cited.

[0171] As the perovskite-type oxide, Li a La 1-a TiO 3 (0 < a < 1) and other Li-La-Ti-based oxides, Li b La 1-b TaO 3 (0 < b < 1) and other Li-La-Ta-based oxides, Li c La 1-c NbO 3 (0 < c < 1) and other Li-La-Nb-based oxides, etc.

[0172] As the NASICON-type oxide, Li 1+d Al d Ti 2-d (PO 4 ) 3 (0 ≤ d ≤ 1), etc. The NASICON-type oxide is Li m M 1 n M 2 o P p O q (In the formula, M 1 is one or more elements selected from the group consisting of B, Al, Ga, In, C, Si, Ge, Sn, Sb, and Se. M 2 is one or more elements selected from the group consisting of Ti, Zr, Ge, In, Ga, Sn, and Al. m, n, o, p, and q are arbitrary positive numbers.) The represented oxide, for example, Li 1+x+y Al x (Ti, Ge) 2-x Si y P 3-y O12 (0 < x < 2, 0 < y < 3) (LATP), etc.

[0173] As a LISICON-type oxide, Li 4 M 3 O 4 -Li 3 M 4 O 4 (M 3 is one or more elements selected from the group consisting of Si, Ge, and Ti. M 4 is one or more elements selected from the group consisting of P, As, and V.) Oxides represented by, etc.

[0174] As a garnet-type oxide, Li 7 La 3 Zr 2 O 12 (LLZ), Li 7-a2 La 3 Zr 2-a2 Ta a2 O 12 (LLZT, 0 < a2 < 1 can be, 0.1 < a2 < 0.8 can be, 0.2 < a2 < 0.6) Li-La-Zr-based oxides, etc.

[0175] The oxide-based solid electrolyte can also be a crystalline material or an amorphous material.

[0176] As an oxide-based solid electrolyte, Li 6.6 La 3 Zr 1.6 Ta 0.4 O 12 , Li 0.33 La 0.55 TiO 3 , etc.

[0177] (Sulfide-based solid electrolyte)

[0178] As a sulfide-based solid electrolyte, Li 2 S-P 2 S 5 -based compounds, Li 2 S-SiS 2 -based compounds, Li 2 S-GeS 2 -based compounds, Li 2 S-B 2 S 3 -based compounds, Li 2 S-P 2 S3 System compounds, LiI - Si 2 S - P 2 S 5 , LiI - Li 2 S - P 2 O 5 , LiI - Li 3 PO 4 -P 2 S 5 , Li 10 GeP 2 S 12 etc.

[0179] It should be noted that in this specification, the expression "system compounds" referring to sulfide - based solid electrolytes is used as a general term for solid electrolytes mainly containing the "Li 2 S", "P 2 S 5 " and other raw materials described before "system compounds". For example, for the Li 2 S - P 2 S 5 system compounds, it includes solid electrolytes containing Li 2 S and P 2 S 5 , and further containing other raw materials. In addition, for the Li 2 S - P 2 S 5 system compounds, it also includes solid electrolytes with different mixing ratios of Li 2 S and P 2 S 5 .

[0180] As Li 2 S - P 2 S 5 system compounds, examples include Li 2 S - P 2 S 5 , Li 2 S - P 2 S 5 -LiI, Li 2 S - P 2 S 5 -LiCl, Li 2 S - P 2 S 5 -LiBr, Li 2 S - P 2 S 5 -Li 2 O, Li 2 S - P 2 S 5 -Li2 O-LiI, Li 2 S-P 2 S 5 -Z m S n (m and n are positive numbers. Z is Ge, Zn or Ga) etc.

[0181] As Li 2 S-SiS 2 series compounds, examples include Li 2 S-SiS 2 , Li 2 S-SiS 2 -LiI, Li 2 S-SiS 2 -LiBr, Li 2 S-SiS 2 -LiCl, Li 2 S-SiS 2 -B 2 S 3 -LiI, Li 2 S-SiS 2 -P 2 S 5 -LiI, Li 2 S-SiS 2 -Li 3 PO 4 , Li 2 S-SiS 2 -Li 2 SO 4 , Li 2 S-SiS 2 -Li x MO y (x and y are positive numbers. M is P, Si, Ge, B, Al, Ga or In) etc.

[0182] As Li 2 S-GeS 2 series compounds, examples include Li 2 S-GeS 2 , Li 2 S-GeS 2 -P 2 S 5 etc.

[0183] The sulfide-based solid electrolyte can be a crystalline material or an amorphous material.

[0184] (Hydride-based solid electrolyte)

[0185] As a hydride-based solid electrolyte material, examples include LiBH4 , LiBH 4 -3KI, LiBH 4 -PI 2 , LiBH 4 -P 2 S 5 , LiBH 4 -LiNH 2 , 3LiBH 4 -LiI, LiNH 2 , Li 2 AlH 6 , Li(NH 2 ) 2 , I, Li 2 , NH, LiGd(BH 4 ) 3 , Cl, Li 2 (BH 4 )(NH 2 ), Li 3 (NH 2 )I, Li 4 (BH 4 )(NH 2 ) 3 etc.

[0186] (Halide-based solid electrolyte)

[0187] As the halide solid electrolyte, compounds containing Li, a metal element, and a halogen element, etc., can be cited.

[0188] The halide solid electrolyte can be a crystalline material or an amorphous material.

[0189] As the solid electrolyte material, compounds obtained by substituting part or all of Li in the compounds cited as specific examples of an oxide-based solid electrolyte, a sulfide-based solid electrolyte, a hydride-based solid electrolyte, or a halide-based solid electrolyte with Na, K, Rb, or Cs can also be cited.

[0190] The positive electrode layer can be a layer formed of a positive electrode material. The positive electrode material (positive electrode layer) can contain a positive electrode active material and, if necessary, a polymer electrolyte, a binder resin, a conductive aid, an organic solvent, an ionic liquid, etc. The positive electrode layer can also be formed on a current collector.

[0191] As the positive electrode active material, there is no particular limitation. For example, alkali metal composite oxides containing an alkali metal element and at least one metal element selected from the group consisting of transition metal elements and Al can be cited. The transition metal element can be at least one selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, and Cu, and Ni can be included. For example, when the alkali metal element is lithium (i.e., in the case of lithium composite oxide), as the lithium composite oxide, for example, LiCoO 2 、LiNiO 2 、LiMn 2 O 4 、Li 2 MnO 3 、LiNi x Mn y Co 1-x-y O 2 [0 < x + y < 1], LiNi x Co y Al 1-x-y O 2 [0 < x + y < 1], LiCr 0.5 Mn 0.5 O 2 、LiFePO 4 、Li 2 FeP 2 O 7 、LiMnPO 4 、LiFeBO 3 、Li 3 V 2 (PO 4 ) 3 、Li 2 CuO 2 、Li 2 FeSiO 4 、Li 2 MnSiO 4 etc. When the positive electrode active material contains an alkali metal element other than Li, as a specific example thereof, a substance obtained by replacing Li in the above specific example with another alkali metal can be cited. As the alkali metal other than Li, Na or K can be cited.

[0192] The binder resin contained in the positive electrode layer (positive electrode material) of the present embodiment is not particularly limited, but fluororesins can be mentioned. As the fluororesin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be a carbon chain formed by radical polymerization of an ethylenically unsaturated group. As the fluororesin, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyvinylidene fluoride (PVDF), etc. can be mentioned. The content of the binder resin in the positive electrode layer can be 0.5 to 15% by mass, and can be 1 to 10% by mass.

[0193] As the conductive additive, carbon nanotubes can be mentioned; graphite materials such as natural graphite (flaky graphite, etc.), artificial graphite, etc.; carbon black materials such as acetylene black, Ketjen black, channel black, furnace black, lamp black, pyrolytic carbon black, etc.; carbon fibers; and other carbon materials. The carbon nanotubes can be either single-layer or multi-layer, and can be multi-layer. The average length of the carbon nanotubes can be 1 μm or more, and can be 5 μm or more. The conductivity of the carbon nanotubes can be metallic. The average diameter of the carbon nanotubes can be 0.4 nm to 100 nm. The BET specific surface area of the carbon nanotubes can be 400 m 2 / g or less. The G / D ratio of the carbon nanotubes can be 10 or less. The tensile strength of the carbon nanotubes can be 50 to 70 MPa. The content of the conductive additive in the positive electrode layer can be 0.05 to 15% by mass, can be 0.1 to 10% by mass, can be 0.5 to 10% by mass, and can be 1 to 7% by mass.

[0194] The solid electrolyte materials contained in the positive electrode can include the above-mentioned solid electrolyte materials.

[0195] The content of the positive electrode active material in the positive electrode material can be 50% by mass or more, can be 60% by mass or more, and can be 70% by mass or more with respect to the total amount of the positive electrode material. The content of the positive electrode active material in the positive electrode material can be 99% by mass or less, can be 95% by mass or less, and can be 90% by mass or less with respect to the total amount of the positive electrode material. In addition, the content of the positive electrode active material in the positive electrode material can be 50 to 99% by mass, can be 60 to 95% by mass, and can be 70 to 90% by mass with respect to the total amount of the positive electrode material.

[0196] The positive electrode material (positive electrode layer) can also contain the above-mentioned polymer having the ability to preferentially conduct metal ions. The content of the polymer in the positive electrode material (positive electrode layer) can be 15% by mass or less, can be 0.5 to 10% by mass, and can be 1 to 7% by mass with respect to the total amount of the electrolyte composition (electrolyte layer).

[0197] The thickness of the positive electrode layer can be 1 to 200 μm, can be 10 to 150 μm, and can be 20 to 100 μm.

[0198] The negative electrode layer can be a layer formed of a negative electrode material. The negative electrode material can include a negative electrode active material and, as needed, a polymer electrolyte, a binder resin, a conductive aid, an organic solvent, an ionic liquid, etc. The negative electrode material (negative electrode layer) can also contain the above polymer having the ability to preferentially conduct metal ions. The negative electrode layer can also be formed on a current collector.

[0199] Examples of the negative electrode active material include monomers of alkali metal elements, Si, P, Sn, Si-Mn, Si-Co, Si-Ni, In, Au, etc., alloys or composites containing these elements, carbon materials such as graphite, substances obtained by intercalating alkali metal ions between the layers of the carbon material, and oxides containing titanium, etc. Specifically, the negative electrode active material can include at least one selected from the group consisting of oxides containing titanium, active materials containing silicon, and carbon materials. Examples of the active material containing silicon include silicon, silicon oxides (SiOx, 1≤x≤2), silicon-containing alloys, etc. Examples of the carbon material include graphite, hard carbon, etc. The alkali metal element can be Li, Na, or K, can be Li or Na, and can be Li.

[0200] Examples of the oxide containing titanium can be a compound represented by the compositional formula: A s TiO t (where A is an alkali metal element, s≥0.). Among them, the alkali metal element A can be Li, Na, or K, can be Li or Na, and can be Li. In the above compositional formula, s can be 0.1 to 2, can be 0.3 to 1.5, and can be 0.5 to 1. In the above compositional formula, t can be 2 to 3, can be 2.2 to 2.8. Specifically, examples of the oxide containing titanium include A 4 Ti 5 O 12 (A is an alkali metal, and can be Li.).

[0201] The binder resin contained in the negative electrode layer (negative electrode material) of the present embodiment is not particularly limited, but examples include fluororesins. As the fluororesin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be a carbon chain formed by radical polymerization of an ethylenically unsaturated group. Examples of the fluororesin include poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyvinylidene fluoride (PVDF), etc. The content of the binder resin in the negative electrode layer can be 0.5 to 10% by mass, and can be 1 to 7% by mass.

[0202] Examples of the conductive aid include carbon materials such as natural graphite (flake graphite, etc.), artificial graphite, etc.; carbon blacks such as acetylene black, Ketjen black, channel black, furnace black, lamp black, pyrolytic carbon black, etc.; carbon fibers; etc. The content of the conductive aid in the negative electrode layer can be 0.5 to 10% by mass, and can be 1 to 7% by mass.

[0203] Examples of the solid electrolyte material contained in the negative electrode include the above-described solid electrolyte materials.

[0204] The content of the negative electrode active material in the negative electrode material (or negative electrode layer) may be 50% by mass or more, may be 60% by mass or more, may be 70% by mass or more, may be 99% by mass or less, may be 95% by mass or less, or may be 90% by mass or less with respect to the total amount of the negative electrode material.

[0205] The negative electrode material (negative electrode layer) may also contain the above-described polymer having the ability to preferentially conduct metal ions. The content of the polymer in the negative electrode material (negative electrode layer) may be 15% by mass or less, may be 0.5 to 10% by mass, or may be 1 to 7% by mass with respect to the total amount of the electrolyte composition (electrolyte layer).

[0206] The thickness of the negative electrode layer may be 1 to 200 μm, may be 10 to 150 μm, or may be 20 to 100 μm.

[0207] The peel strength between the positive electrode layer and the electrolyte layer may be 1 N / m or more.

[0208] The peel strength between the negative electrode layer and the electrolyte layer may be 1 N / m or more.

[0209] Examples of the battery of the present embodiment include batteries that are charged and discharged by the movement of alkali metal ions, such as lithium ion batteries and sodium ion batteries. The battery may be a primary battery, a secondary battery, or a solid battery.

[0210] In the present embodiment, a composite film including a fibrous substrate or a porous substrate and the above-described polymer having the ability to preferentially conduct metal ions is also provided. Such a composite film can be used, for example, as an electrolyte of a battery. In addition, the composite film can also be disposed between the positive electrode and another electrolyte, or between the negative electrode and another electrolyte as a short-circuit prevention film.

[0211] As the material of the fibrous substrate or the porous substrate (hereinafter also referred to as the substrate), there is no particular limitation. It can be an organic substance, an inorganic substance, a natural substance, or a synthetic resin. The substrate can be in the form of a sheet. Examples of the substrate include fabrics, polymer films, inorganic porous films, etc. The fabric can be a woven fabric or a non-woven fabric. In addition, the fibers contained in the fabric can be at least one of polymer fibers and inorganic fibers. Examples of the substrate containing natural substances include substrates containing vegetable fibers such as paper, and substrates containing animal fibers such as wool. There is no particular limitation on the synthetic resin, and examples thereof include polyolefins, polyamides, polyimides, polyamideimides, polyacetals, polyacrylic acids, polyesters, polycarbonates, polysulfones, polyphenylene sulfides, polyether ether ketones, polyether sulfone polyetherimides, cellulose ethers, polybenzimidazoles, polyurethanes, melamine resins, or copolymers or mixtures thereof. The substrate can be a substrate obtained by laminating a porous film of a polyolefin (e.g., polyethylene) and an aromatic polyamide (aramid), or can contain a polyolefin porous film. There is no particular limitation on the inorganic substance, and examples thereof include glass, etc. Examples of the substrate of the inorganic substance include glass wool, porous glass films, etc. In addition, the inorganic substance can also have ionic conductivity. The substrate can contain one or more materials.

[0212] The thickness of the substrate can be 1 to 20 μm, can be 5 to 15 μm, or can be 9 to 15 μm. If the film thickness is 1 μm or more, the functions required for the substrate (such as strength) can be sufficiently obtained.

[0213] The pore diameter of the pores of the substrate can be 1.0 μm or less, can be 0.5 μm or less, or can be 0.1 μm or less. Thereby, sufficient ion permeability can be obtained, and the entry of the particles constituting the electrode can be further prevented.

[0214] In order to improve the weight energy density and volume energy density of the battery, the weight per unit area of the substrate, that is, the unit area weight, can generally be 1 to 20 g / m 2 , and can be 3 to 12 g / m 2 .

[0215] The air permeability of the substrate can be 1 to 500 s / 100 mL in Gurley value, or can be 30 to 300 s / 100 mL. Thereby, the composite film can obtain sufficient ion permeability.

[0216] The porosity of the substrate can be 20 to 90% by volume, or can be 30 to 75% by volume. Thereby, the retention amount of the electrolyte can be increased, and an excessive current can be reliably blocked (shutdown) at a lower temperature.

[0217] The puncture strength of the base material can be 0.5 N or more, and can be 2 N or more. If the puncture strength is in such a range, there is a tendency to suppress the composite film from being punctured by the positive and negative active material particles and short-circuiting between the positive and negative electrodes in the case of the lamination and winding operation in the battery assembly process, the mold closing operation of the wound coil, or applying pressure to the battery from the outside, etc.

[0218] Among them, the "polyolefin porous membrane" is a porous membrane mainly composed of a polyolefin resin. In addition, the so-called "mainly composed of a polyolefin resin" means that the proportion of the polyolefin resin in the porous membrane is 50% by volume or more, preferably 90% by volume or more, and more preferably 95% by volume or more of the entire material constituting the porous membrane.

[0219] The polyolefin resin that is the main component of the polyolefin porous membrane is not particularly limited, and examples thereof include homopolymers and copolymers formed by polymerizing monomers such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, and / or 1-hexene as thermoplastic resins. That is, as homopolymers, polyethylene, polypropylene, polybutene, etc. can be cited, and as copolymers, ethylene-propylene copolymers, etc. can be cited. The polyolefin porous membrane can be a layer containing only these polyolefin resins or a layer containing two or more of these polyolefin resins.

[0220] As polyethylene, low-density polyethylene, high-density polyethylene, linear polyethylene (ethylene-α-olefin copolymer), ultra-high molecular weight polyethylene, etc. can be cited. The polyethylene can be ultra-high molecular weight polyethylene and can contain a high molecular weight component with a weight average molecular weight of 5×10 5 ~15×10 6 .

[0221] The manufacturing method of the polyolefin porous membrane can use a known method and is not particularly limited. For example, a method of adding a filler to a thermoplastic resin, forming a film, and then removing the filler as described in Japanese Patent No. 5476844 can be cited.

[0222] Specifically, for example, when the polyolefin porous membrane is formed from a polyolefin resin containing ultra-high molecular weight polyethylene and a low molecular weight polyolefin with a weight average molecular weight of 10,000 or less, from the viewpoint of manufacturing cost, it is preferably manufactured by a method including the following steps (1) to (4).

[0223] (1) A step of kneading 100 parts by mass of ultra-high molecular weight polyethylene, 5 parts by mass to 200 parts by mass of a low molecular weight polyolefin with a weight average molecular weight of 10,000 or less, and 100 parts by mass to 400 parts by mass of an inorganic filler such as calcium carbonate to obtain a polyolefin resin composition;

[0224] (2) A step of forming a sheet using the polyolefin resin composition;

[0225] (3) Step of removing the inorganic filler from the sheet obtained in step (2);

[0226] (4) Step of stretching the sheet obtained in step (3).

[0227] In addition, the methods described in the above-mentioned patent documents can also be used.

[0228] As a method for manufacturing the composite film, there is no particular limitation, but examples include a method of impregnating a substrate with a polymer having the ability to preferentially conduct metal ions and drying it, etc. When impregnating the polymer into the substrate, it can also be impregnated into the substrate as the above-mentioned electrolyte composition. The composite film can also be manufactured by a roll-to-roll method.

[0229] Examples

[0230] [Manufacture of Polymer Having the Ability to Preferentially Conduct Metal Ions]

[0231] As follows, a copolymer of monomer A1 represented by the following formula and styrene (molar ratio: 54:46) was manufactured.

[0232] [Chemical Formula 14]

[0233]

[0234] First, monomer A1 was manufactured as follows.

[0235] (Synthesis of Monomer A1)

[0236] Under a nitrogen atmosphere, trifluoromethanesulfonamide (52.5 mmol, 7.83 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated acetonitrile (150 mL, manufactured by Kanto Chemical Co., Inc.). Lithium hydroxide (105 mmol, 2.51 g, manufactured by Tokyo Chemical Industry Co., Ltd.) and 4-acetamidobenzenesulfonyl chloride (50 mmol, 11.68 g, manufactured by Tokyo Chemical Industry Co., Ltd.) were successively added to this solution and heated under reflux for 5 hours. After cooling to room temperature, an excess of acetonitrile (700 mL) was added to precipitate a solid, which was separated by filtration and then washed with dichloromethane (manufactured by Kanto Chemical Co., Inc.) to obtain Intermediate 1. The yield was 97.1%.

[0237] · Structural formula of Intermediate 1:

[0238] [Chemical Formula 15]

[0239]

[0240] 5% hydrochloric acid (22.5 mL) was added to Intermediate 1 (15 mmol, 5.28 g) under a nitrogen atmosphere, and the mixture was stirred at 90 °C for 2 hours. After cooling to room temperature, an aqueous lithium hydroxide solution was added until the pH reached 7 or higher based on confirmation using pH test paper, etc., and the solid was obtained by drying under reduced pressure. The obtained solid was extracted with an acetonitrile solution, and Intermediate 2 was obtained by drying under reduced pressure. The yield was 92.6% based on the raw material of the above Intermediate 1.

[0241] · Structural formula of Intermediate 2:

[0242] [Chemical formula 16]

[0243]

[0244] Maleic anhydride (13.3 mmol, 1.30 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated 1,4-dioxane (manufactured by Kanto Chemical Co., Inc.) under a nitrogen atmosphere. A solution of Intermediate 2 (13.2 mmol, 4.09 g) adjusted under a nitrogen atmosphere in dehydrated tetrahydrofuran (26.4 mL, manufactured by Kanto Chemical Co., Inc.) was added dropwise to this solution in total amount, and the mixture was stirred at room temperature for 12 hours. After the reaction, the precipitate was filtered, and vacuum dried at 60 °C for 4 hours to obtain a solid containing Intermediate 3.

[0245] · Structural formula of Intermediate 3:

[0246] [Chemical formula 17]

[0247]

[0248] A solid containing Intermediate 3 (14.0 mmol, 5.70 g) and an aqueous sodium acetate solution (13.3 mmol, 1.09 g, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to acetic anhydride (12.3 mL, manufactured by Tokyo Chemical Industry Co., Ltd.) under a nitrogen atmosphere, and the mixture was stirred at 70 °C for 3 hours. The total amount of the reaction solution was added dropwise to an excess of diethyl ether (manufactured by Kanto Chemical Co., Inc.) at 0 °C, and the precipitate was recovered by filtration. The precipitate was extracted with dehydrated acetonitrile (manufactured by Kanto Chemical Co., Inc.) under an inert atmosphere and dried under reduced pressure to obtain Monomer A1. The yield via all processes was 72.8%.

[0249] Dissolve 3.121 g of monomer A1, 0.833 g of styrene, and 57.5 mg of AIBN in 70 mL of dehydrated acetonitrile. Add tetralin as an internal standard substance, and while confirming the monomer consumption rate, react at 60 °C for 24 hours under a nitrogen atmosphere. By dialyzing the polymerization solution in acetonitrile and performing vacuum drying at 120 °C, 3.50 g of polymer (yield 89%) was obtained. The monomer feed ratio was A1:styrene = 54:46. The monomer feed ratio was calculated by 1 1H-NMR of the copolymer. It should be noted that as styrene, a commercially available reagent with a purity > 98% manufactured by Aldrich was sealed and dried overnight with CaCl 2 and then CaH was added 2 for vacuum distillation to increase the purity before use.

[0250] The copolymer had a number-average molecular weight Mn = 9.3×10 4 and a weight-average molecular weight Mw = 3.0×10 5 with a molecular weight distribution Mw / Mn = 3.19.

[0251] [Manufacture of Electrode Material]

[0252] (Positive Electrode Material 1)

[0253] Mix LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 used as the positive electrode active material, acetylene black, and polyvinylidene fluoride (PVDF) in a mass ratio of 87:4.3:8.7 to obtain Positive Electrode Material 1. The details of the positive electrode active material are as follows.

[0254] Nominal: LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2

[0255] Composition analysis by ICP: Li 1.05 Ni 0.33 Co 0.33 Mn 0.34 O 2

[0256] Crystal structure: R-3m

[0257] Average particle size: 10 μm

[0258] (Positive Electrode Material 2)

[0259] Mix LiFePO 4(LFP), a polymer having the ability to preferentially conduct metal ions manufactured as described above, carbon nanotubes, and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were mixed at a mass ratio of 93.5:3:0.5:3 to obtain a positive electrode material 2. The details of the positive electrode active material are as follows. It should be noted that the carbon nanotubes are multi-layered and have an average diameter of 10 nm.

[0260] Nominal: LiFePO 4

[0261] Crystal structure: Pnma

[0262] Average particle size: 1.0 μm

[0263] (Negative electrode material 1)

[0264] Lithium titanate (Li 4 Ti 5 O 12 ), a polymer having the ability to preferentially conduct metal ions manufactured as described above, acetylene black, and polyvinylidene fluoride (PVDF) were mixed at a mass ratio of 87:4.3:4.3:4.3 to obtain a negative electrode material 1. The details of the negative electrode active material are as follows.

[0265] Li 4 Ti 5 O 12

[0266] Crystal structure: Spinel structure

[0267] Average particle size: 10 μm

[0268] [Manufacture of electrolyte]

[0269] (Electrolyte 1)

[0270] A polymer having the ability to preferentially conduct metal ions manufactured as described above and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were compounded and dissolved in DMF in a mass ratio of 50:50. By impregnating this solution into a polyethylene film and drying it, a composite film was obtained. In this composite film, an organic solvent (ethylene carbonate: propylene carbonate = 1:1 (volume ratio)) (KISHIDA CHEMICAL CO., LTD.) was compounded in such a way that it became 200 parts by mass with respect to 100 parts by mass of the total mass of the polymer having the ability to preferentially conduct metal ions and PVDF-HFP, and an electrolyte composition (electrolyte 1) was manufactured.

[0271] (Electrolyte 2)

[0272] In a 10% by mass aqueous solution of poly(ethylene oxide) (Poly(ethylene oxide) average Mv 600,000, powder) manufactured by Aldrich, lithium bis(fluorosulfonyl)imide (LiFSI) manufactured by KISHIDA CHEMICAL CO., LTD. was mixed at a molar ratio of O atom:Li atom = 20:1 with respect to poly(ethylene oxide) to obtain Electrolyte 2.

[0273] (Electrolyte 3)

[0274] The polymer having the ability to preferentially conduct metal ions manufactured as described above and poly(vinylidene fluoride - co - hexafluoropropylene) (PVDF - HFP) were blended in a mass ratio of 100:50 and dissolved in DMF. By impregnating this solution into a polyethylene membrane and drying it, a composite membrane was obtained. In this composite membrane, an organic solvent (ethylene carbonate:propylene carbonate = 1:1 (volume ratio)) (KISHIDA CHEMICAL CO., LTD.) was blended in such a manner that it became 100 parts by mass with respect to 100 parts by mass of the total mass of the polymer having the ability to preferentially conduct metal ions and PVDF - HFP to manufacture an electrolyte composition (Electrolyte 3).

[0275] (Charge - discharge test)

[0276] Inside a glove box, under a dry argon atmosphere, an evaluation cell (half - cell) of a coin - type battery CR2032 was assembled using the electrode material and electrolyte composition manufactured with the combinations of materials shown in Table 1. Specifically, in the evaluation cell, each layer was stacked in the following order to fabricate a test laminate.

[0277] (Electrode / Electrolyte composition / Lithium)

[0278] Using the above - mentioned evaluation cell, charge - discharge measurements were carried out in the range of 2.5 - 4.3 V (vs. Li / Li + )). The number of cycles was 5 times in Example 1 and Comparative Example 1, and 10 times in Example 2 and Example 3.

[0279] Table 1

[0280]

[0281] * Thickness of working electrode / Thickness of electrolyte layer

[0282] In Figures 1 to 5The results of charge-discharge tests on the half-cells of Example 1, Example 2, Example 3, and Comparative Example 1 are shown respectively. For the battery of Example 1, the cycle capacity retention rate after 5 cycles was 97%. On the other hand, for the battery of Comparative Example 1, the cycle capacity retention rate after 5 cycles was 70%. The batteries of Example 2 and Example 3 also worked properly.

[0283] <Evaluation Using a Full Cell>

[0284] An evaluation battery (full cell) of a coin-type battery CR2032 was fabricated in the same manner as in Example 1, except that the negative electrode material of Example 2 was used for the negative electrode. Using the above evaluation battery, 10-cycle charge-discharge measurements were performed in the range of 0.5 - 3.3 V (vs. Li / Li + ). Figure 4 It is a graph showing the results of the charge-discharge test of the full cell.

[0285] <Measurement of Lithium Ion Transference Number>

[0286] (Reference Example 1)

[0287] An electrolyte composition was prepared that contained a polymer having the ability to preferentially conduct metal ions, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and an organic solvent (ethylene carbonate:propylene carbonate = 1:1 (volume ratio)) (KISHIDA CHEMICAL CO., LTD.) in a mass ratio of 17:17:66.

[0288] (Reference Comparative Example 1)

[0289] An electrolyte composition was prepared that contained a mixture of poly(ethylene oxide) (average Mv 600,000, powder) manufactured by Aldrich and lithium bis(fluorosulfonyl)imide (LiFSI) manufactured by Kanto Chemical Co., Inc. (in a mol ratio of O atoms:Li atoms = 20:1).

[0290] The transference number of the above electrolyte composition was measured by the following method. The results are shown in Table 2.

[0291] Lithium ion transference number:

[0292] Inside a glove box, under a dry argon atmosphere, an evaluation battery of a coin-type lithium battery CR2032 was assembled. Specifically, inside the evaluation battery, each layer was stacked in the following order to fabricate a test laminate. (Li / electrolyte composition / Li)

[0293] The method for measuring the lithium ion transference number is the method described in Polymer, 28, 2324 (1987). That is, at room temperature (25 °C), a voltage of 10 mV is applied to the test laminate, and the initial current value (I 0 ) and the steady current value (I ss ) are measured. Further, the measured value of the interfacial resistance R 0 before voltage application and the measured value of the interfacial resistance R SS after voltage application are obtained by the complex impedance method. Then, the obtained values are substituted into the following formula to calculate the lithium ion transference number (t Li+ ). V in the formula is the applied voltage.

[0294] t Li+ = I ss (V - I 0 R 0 ) / I 0 (V - I SS R SS )

[0295] Table 2

[0296] Lithium ion transference number (-) Reference Example 1 0.91 Reference Comparative Example 1 0.40

Claims

1. A battery comprising a positive electrode layer, a negative electrode layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer. The electrolyte layer contains a polymer having the ability to preferentially conduct metal ions. The thickness ratio of the positive electrode layer to the electrolyte layer is from 10:1 to 0.5:

1.

2. A battery comprising a positive electrode layer, a negative electrode layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer. The electrolyte layer contains a polymer having the ability to preferentially conduct metal ions. The thickness ratio of the negative electrode layer to the electrolyte layer is from 5:1 to 0.5:

1.

3. The battery according to claim 1 or 2, wherein, the polymer has at least one of an anionic functional group having an alkali metal ion as a counter cation and a functional group having an anion capturing ability.

4. The battery according to claim 1 or 2, wherein, the positive electrode layer contains a nickel-containing lithium composite oxide as a positive electrode active material.

5. The battery according to claim 1 or 2, wherein, the negative electrode layer contains at least one selected from the group consisting of an oxide containing titanium, an active material containing silicon, and a carbon material as a negative electrode active material.

6. The battery according to claim 1 or 2, wherein, the electrolyte layer contains an ionic liquid.

7. The battery according to claim 1, wherein, the peel strength between the positive electrode layer and the electrolyte layer is 1 N / m or more.

8. The battery according to claim 2, wherein, the peel strength between the negative electrode layer and the electrolyte layer is 1 N / m or more.

9. A composite film comprising a fibrous substrate or a porous substrate and a polymer having the ability to preferentially conduct metal ions.

Images