Electrolyte composition, electrolyte and battery

Abstract

An electrolyte composition containing an ion-conductive inorganic solid electrolyte, a polymer having the ability to preferentially conduct metal ions, and an organic solvent, the content of the ion-conductive inorganic solid electrolyte satisfying at least one of the following conditions: (1) 50 mass% or more with respect to the total amount of the electrolyte composition; and (2) 15 vol% or more with respect to the total amount of the electrolyte composition.

Description

Technical Field

[0001] The present disclosure relates to electrolyte compositions, electrolytes, and batteries. Background Art

[0002] Lithium ion batteries and other batteries that are charged and discharged with the migration of metal ions between the positive electrode and the negative electrode are being actively studied due to their high capacity. As electrolytes for lithium ion batteries, solutions of lithium salts containing organic solvents or ionic liquids are known, and for the sake of safety and processability, research on solid electrolytes is being promoted (Patent Documents 1 and 2 and Non-Patent Document 1). As solid electrolytes, various types of compounds such as oxide-based solid electrolytes and sulfide-based solid electrolytes are known.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Chinese Patent Application No. 112448100

[0006] Patent Document 2: Chinese Patent Application No. 110247111

[0007] Non-patent literature

[0008] Non-patent literature 1: Journal of The Electrochemical Society, 2020, 167, 070559. Summary of the invention

[0009] Problems to be solved by the invention

[0010] Here, the ion conductivity and safety of solid electrolytes are excellent, but on the other hand, there is a problem that the processability is lacking due to its rigidity and the interface resistance is also high. Therefore, for example, as described in patent documents 1 and 2 and non-patent document 1, research is being conducted on giving solid electrolytes flexibility by composite with soft polymer materials. However, the inventors have conducted in-depth research, and the results show that there is a problem that the migration number of metal ions is greatly reduced in the composite with existing polymer materials.

[0011] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide an electrolyte composition and an electrolyte having excellent transference number of metal ions, and a battery including the same.

[0012] Means used to solve problems

[0013] The present disclosure includes the following exemplary embodiments [1] to

[10] .

[0014] [1] An electrolyte composition comprising an ion-conductive inorganic solid electrolyte, a polymer having the ability to preferentially conduct metal ions, and an organic solvent, wherein the content of the ion-conductive inorganic solid electrolyte satisfies at least one of the following conditions: (1) 50% by mass or more relative to the total amount of the electrolyte composition; and (2) 15% by volume or more relative to the total amount of the electrolyte composition.

[0015] [2] The electrolyte composition according to [1], wherein the ion-conductive inorganic solid electrolyte is an oxide, a sulfide, a hydride or a halide, and contains at least one of an alkali metal element and an alkaline earth metal.

[0016] [3] The electrolyte composition according to [2], wherein the ion-conductive inorganic solid electrolyte is a perovskite-type oxide, a NASICON-type oxide, a LISICON-type oxide, or a garnet-type oxide.

[0017] [4] The electrolyte composition according to any one of [1] to [3], wherein the polymer has at least one of an anionic functional group having a metal ion as a counter cation and a functional group having an anion capturing ability.

[0018] [5] The electrolyte composition according to any one of [1] to [4], wherein the transference number of the metal ion is 0.4 or more.

[0019] [6] The electrolyte composition according to any one of [1] to [5], wherein the oxidation potential relative to Li / Li + is 4.0V or above.

[0020] [7] An electrolyte composition having a dynamic hardness DH calculated from the test results of a nanoindenter at 25°C according to the following formula of 10 3 N / mm 2 the following:

[0021] DH=α×F / h 2 ×10 3 ,

[0022] α=3.8584.

[0023] [8] The electrolyte composition according to any one of [1] to [6], wherein the dynamic hardness DH calculated from the test results using a nanoindenter at 25° C. according to the following formula is 10 3 N / mm 2 the following:

[0024] DH=α×F / h 2 ×10 3 ,

[0025] α=3.8584.

[0026] [9] An electrolyte comprising the electrolyte composition according to any one of [1] to [8].

[0027]

[10] A battery comprising the electrolyte composition according to any one of [1] to [8].

[0028] Effects of the Invention

[0029] According to the present disclosure, it is possible to provide an electrolyte composition and electrolyte having excellent transference numbers of metal ions, and a battery including the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 These are the results of the charge and discharge test of Example 2.

[0031] Figure 2 These are the results of the charge and discharge test of Comparative Example 4.

[0032] Figure 3 This is the differential capacity curve of Example 2.

[0033] Figure 4 This is the differential capacity curve of Comparative Example 4. DETAILED DESCRIPTION

[0034] The electrolyte composition of the present embodiment is an electrolyte composition comprising an ion-conductive inorganic solid electrolyte, a polymer having the ability to preferentially conduct metal ions, and an organic solvent, and the content of the ion-conductive inorganic solid electrolyte satisfies at least one of the following: (1) 50% by mass or more relative to the total amount of the aforementioned electrolyte composition; and (2) 15% by volume or more relative to the total amount of the aforementioned electrolyte composition.

[0035] [Ion-conductive inorganic solid electrolyte]

[0036] The ion-conductive inorganic solid electrolyte is not particularly limited, and may be an oxide (oxide-based solid electrolyte), a sulfide (sulfide-based solid electrolyte), a hydride (hydride-based solid electrolyte), or a halide (halide-based solid electrolyte), etc. The ion-conductive inorganic solid electrolyte may contain at least one of an alkali metal element and an alkaline earth metal element, and may also contain an alkali metal element.

[0037] (Oxide-based solid electrolyte)

[0038] As an oxide-based solid electrolyte, examples include oxides such as perovskite-type oxides, NASICON-type oxides, LISICON-type oxides, garnet-type oxides, and oxides doped with other cations or anions.

[0039] As perovskite-type oxides, examples include Li a La 1-a TiO3 (0 < a < 1) and other Li-La-Ti-based oxides, Li b La 1-b TaO3 (0 < b < 1) and other Li-La-Ta-based oxides, Li c La 1-c NbO3 (0 < c < 1) and other Li-La-Nb-based oxides.

[0040] As NASICON-type oxides, examples include Li 1+d Al d Ti 2-d (PO4)3 (0 ≤ d ≤ 1) and the like. NASICON-type oxides are oxides represented by Li m M 1 n M 2 o P p O q (wherein, 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.), examples include Li 1+x+y Al x (Ti, Ge) 2-x Si y P 3-y O 12 (0 < x < 2, 0 < y < 3) (LATP) and the like.

[0041] As LISICON-type oxides, examples include oxides represented by Li4M 3 O4 - Li3M 4 O4 (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.) and the like.

[0042] As garnet-type oxides, examples include Li7La3Zr2O 12 (LLZ), Li7-a2 La3Zr 2-a2 Ta a2 O 12 (LLZT, where 0 < a2 < 1, or 0.1 < a2 < 0.8, or 0.2 < a2 < 0.6, etc., such as Li-La-Zr series oxides, etc.)

[0043] The oxide-based solid electrolyte can be a crystalline material or an amorphous material.

[0044] As the oxide-based solid electrolyte, examples include Li 6.6 La3Zr 1.6 Ta 0.4 O 12 、Li 0.33 La 0.55 TiO3, etc.

[0045] (Sulfide-based solid electrolyte)

[0046] As the sulfide-based solid electrolyte, examples include Li2S-P2S5 series compounds, Li2S-SiS2 series compounds, Li2S-GeS2 series compounds, Li2S-B2S3 series compounds, Li2S-P2S3 series compounds, LiI-Si2S-P2S5, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 10 GeP2S 12 etc.

[0047] It should be noted that in this specification, the expression "series compound" referring to the sulfide-based solid electrolyte is used as a general term for solid electrolytes mainly containing raw materials such as "Li2S" and "P2S5" recorded before "series compound". For example, the Li2S-P2S5 series compound includes solid electrolytes that contain Li2S and P2S5 and also contain other raw materials. In addition, the Li2S-P2S5 series compound also includes solid electrolytes with different mixing ratios of Li2S and P2S5.

[0048] As the Li2S-P2S5 series compound, examples include Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-LiCl, Li2S-P2S5-LiBr, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-P2S5-Z m S n (m, n are positive numbers. Z is Ge, Zn or Ga), etc.

[0049] As Li2S-SiS2 compounds, there are Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li2SO4, Li2S-SiS2-Li x MO y (x and y are positive numbers. M is P, Si, Ge, B, Al, Ga or In), etc.

[0050] As Li2S-GeS2 series compounds, Li2S-GeS2, Li2S-GeS2-P2S5 and the like can be listed.

[0051] The sulfide-based solid electrolyte may be a crystalline material or an amorphous material.

[0052] (Hydride-based solid electrolyte)

[0053] As hydride-based solid electrolyte materials, there can be listed LiBH4, LiBH4-3KI, LiBH4-PI2, LiBH4-P2S5, LiBH4-LiNH2, 3LiBH4-LiI, LiNH2, Li2AlH6, Li(NH2)2I, Li2NH, LiGd(BH4)3Cl, Li2(BH4)(NH2), Li3(NH2)I, Li4(BH4)(NH2)3, etc.

[0054] (Halide-based solid electrolyte)

[0055] Examples of the halide solid electrolyte include compounds containing Li, a metal element, and a halogen element.

[0056] The halide solid electrolyte may be a crystalline material or an amorphous material.

[0057] As ion-conductive inorganic solid electrolytes, compounds obtained by replacing part or all of the Li in the compounds listed as specific examples of oxide-based solid electrolytes, sulfide-based solid electrolytes, hydride-based solid electrolytes or halide-based solid electrolytes with Na, K, Rb or Cs can also be listed.

[0058] Relative to the total amount of the electrolyte composition, the content of the ion-conductive inorganic solid electrolyte may be 50% by mass or more, 55% by mass or more, 60% by mass or more, 65% by mass or more, or 70% by mass or more. In addition, relative to the total amount of the electrolyte composition, the content of the ion-conductive inorganic solid electrolyte may be 95% by mass or less, 90% by mass or less, or 85% by mass or less. In addition, relative to the total amount of the electrolyte composition, the content of the ion-conductive inorganic solid electrolyte may be 50 to 95% by mass, 55 to 90% by mass, or 60 to 85% by mass.

[0059] Relative to the total amount of the electrolyte composition, the content of the ion-conductive inorganic solid electrolyte can be 15% by volume or more, 25% by volume or more, 35% by volume or more, 40% by volume or more, 45% by volume or more, or 50% by volume or more. In addition, relative to the total amount of the electrolyte composition, the content of the ion-conductive inorganic solid electrolyte can be 90% by volume or less, 80% by volume or less, 70% by volume or less, or 60% by volume or less. In addition, relative to the total amount of the electrolyte composition, the content of the ion-conductive inorganic solid electrolyte can be 15 to 90% by volume, 25 to 80% by volume, or 35 to 60% by volume. It should be noted that in this specification, unless otherwise stated, the volume % is calculated based on the volume of each component contained in the electrolyte composition before mixing. In the case of a known mass ratio of each component contained in the electrolyte composition, it can be a value obtained by dividing the mass ratio of each component by the density.

[0060] The ion-conductive inorganic solid electrolyte may be a particle surface treated. Specifically, the surface non-conductive layer may be removed by using an acid, or a covalent bond may be formed with an atom. The acid is not particularly limited, and hydrochloric acid, nitric acid, phosphoric acid, etc. may be mentioned.

[0061] [Polymer having the ability to preferentially conduct metal ions]

[0062] As a polymer having the ability to preferentially conduct metal ions (hereinafter also referred to as a polymer), for example, when the migration number of metal ions is measured at room temperature (25°C) for at least one of the following compositions (A) and (B), the polymer may have a migration number of metal ions of 0.4 or more, 0.5 or more, 0.6 or more, or 0.7 or more.

[0063] (A) A composition comprising 33% by mass of the polymer and 67% by mass of a nonionic plasticizer

[0064] (B) A composition comprising 31.9 mass % of the polymer and the remaining total amount of a metal salt and a nonionic plasticizer and having a metal ion concentration of 0.3 mol / L

[0065] Regarding the metal ions contained in the composition, when the polymer has an anionic functional group, it may be a counter cation of the anionic functional group, or it may be a substance added as a metal salt. The polymer having the ability to preferentially conduct metal ions may be a polymer having the ability to preferentially conduct alkali metal ions. As a nonionic plasticizer, at least one of other resins such as an organic solvent and a fluorine-based resin can be listed. The organic solvent may be an aprotic solvent. The aprotic solvent may be at least one selected from the group consisting of a carbonate-based solvent, a fluorine-based solvent, and an ether-based solvent. As a fluorine-based resin, a resin having a carbon chain as the main chain is preferred. The carbon chain may be formed by free radical polymerization of ethylenically unsaturated groups. The fluorine-based resin may be poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). As a specific example of an organic solvent, it may be a specific example of an organic solvent contained in the electrolyte composition described later. The organic solvent may be a mixed solvent containing ethylene carbonate and propylene carbonate in a volume ratio of 1:1.

[0066] The concentration of metal ions can be adjusted by adding metal salts. For example, when the metal salt is an alkali metal salt, the alkali metal salt is not particularly limited, and the alkali metal is denoted as M, and examples thereof include MF, MCl, MBr, MI, MClO4, MPF6, MBF4, M2SO4, M[(C h F 2h+1 )SO3](h is 0~3), M[(C h F 2h+1 )SO2]2N (h is 0 to 3), etc. When the polymer has the structural unit (A), M may be the same alkali metal element as the alkali metal element contained in the structural unit (A).

[0067] The polymer having the ability to preferentially conduct metal ions can be listed as a polymer containing at least one of an anionic functional group having a 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). The structure of the polymer is not particularly limited, and a structure having a carbon chain as a main chain can be listed, and the carbon chain can be formed by free radical addition polymerization of a monomer having an ethylenically unsaturated group.

[0068] The metal ion as the counter cation of the functional group (A) can be at least one of an alkali metal ion and an alkaline earth metal ion, or an alkali metal ion. As the alkali metal ion, lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion, etc. can be listed, which can be lithium ion, sodium ion or potassium ion, or lithium ion or sodium ion, or lithium ion. Hereinafter, the structural unit comprising the functional group (A) and the metal ion as the counter cation of the functional group (A) is also referred to as structural unit (A). The structural unit (A) can have a structure obtained by free radical addition polymerization of a monomer having an ethylenically unsaturated group. The metal ion as the counter cation of the functional group (A) can be an alkali metal ion identical to the alkali metal ion contained in the ion-conductive inorganic solid electrolyte.

[0069] The structural unit (A) may have at least one selected from the group consisting of a conjugated anion of a sulfonyl imide group, a conjugated anion of a sulfonic acid group, and a conjugated anion of a phenolic hydroxyl group as the functional group (A). The conjugated anion of a sulfonyl imide group, the conjugated anion of a sulfonic acid group, and the conjugated anion of a phenolic hydroxyl group may be included in the group having a conjugated anion of a sulfonyl imide group, the group having a conjugated anion of a sulfonic acid group (sulfonate group), and the group having a conjugated anion of a phenolic hydroxyl group described below.

[0070] The group having a sulfonimide group may be included in the structural unit (A) represented by the following formula (A1).

[0071] [Chemical formula 1]

[0072]

[0073] (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, and M + is an alkali metal ion, and * indicates the position where the structural unit (A1) is bonded to other structural units.

[0074] As X, there is no particular limitation, and it can be a hydrocarbon group, a group having a heteroatom, or a heterocycle. As X, more specifically, there can be listed divalent groups such as hydrocarbon groups, groups having a chemical structure in which one or more carbon atoms (methylene) of a hydrocarbon group are replaced by a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-. It should be noted that when there are multiple connecting groups, these connecting groups are not adjacent to each other. In addition, the above-mentioned divalent group may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As a substituent, it can be a univalent substituent, for example, a halogen atom can be listed. As the above-mentioned hydrocarbon group, there is no particular limitation, and it can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As an aliphatic hydrocarbon group, it can be any one of a straight-chain hydrocarbon group, a branched hydrocarbon group and a cyclic hydrocarbon group. In addition, the hydrocarbon group can be any one 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 via a carbon atom of X.

[0075] The number of carbon atoms possessed by X may be 1 to 15, 2 to 10, or 3 to 8. X may be a group having an aromatic ring, or a group having an aromatic carbocyclic ring such as a benzene ring. Substituents such as an alkyl group, a halogen atom, or an electron-withdrawing group may be bonded to the carbon atom that is a ring member of the carbocyclic ring. The hydrocarbon group as X is preferably a phenylene group, an alkylene group having 1 to 8 carbon atoms, a polyoxyalkylene group, or a group in which a part or all of the hydrogen atoms bonded to the carbon atoms they possess are replaced by halogen atoms such as fluorine atoms, and more preferably a phenylene group or a substituted phenylene group substituted by an alkyl group, a halogen atom, an electron-withdrawing group, or the like. As the electron-withdrawing group, halogen atoms, sulfonic acid groups or their salts, sulfonic acid esters, nitro groups, nitrile groups, etc. may be listed.

[0076] In formula (A1), when Y is a monovalent organic group, the organic group is not particularly limited and may be a hydrocarbon group, a group having a heteroatom, or a heterocycle. More specifically, as Y, a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene) of a hydrocarbon group are replaced by a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-, etc. may be listed. It should be noted that when there are multiple connecting groups, the connecting groups are not adjacent to each other. In addition, the above-mentioned monovalent group may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As a substituent, a monovalent substituent may be listed, for example, a halogen atom may be listed. As the above-mentioned hydrocarbon group, there is no particular limitation and it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As an aliphatic hydrocarbon group, it may be any one of a straight-chain hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any one of a saturated hydrocarbon group and an unsaturated hydrocarbon group.

[0077] The number of carbon atoms possessed by Y may be 1 to 15, 1 to 10, 1 to 8, 1 to 5, or 1 to 3. The hydrocarbon group as Y is preferably a phenyl group, an alkyl group having 1 to 5 carbon atoms, or a group in which a part or all of the hydrogen atoms bonded to the carbon atoms possessed by these groups are substituted by halogen atoms such as fluorine atoms, more preferably a fluorinated alkyl group having 1 to 5 carbon atoms, and further preferably a fluorinated alkyl group having 1 to 3 carbon atoms such as a trifluoromethyl group. The fluorinated alkyl group may be a perfluoroalkyl group. When Y is a halogen atom, the halogen atom is preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom.

[0078] In formula (A1), M + Preferably, lithium ion (Li + ), sodium ion (Na + ) or potassium ion (K + ), more preferably lithium ion. + Can contain Li + 、Na + and K + The two or three ions in the mixture preferably contain substantially only a single ion.

[0079] The group having a conjugated anion of a phenolic hydroxyl group is a group having a group obtained by alkali metalizing a hydroxyl group directly bonded to an aromatic ring (ie, a phenolic hydroxyl group (-OH)) (ie, a -OM group in which M is an alkali metal).

[0080] The structural unit (A) may be a group represented by the following formula (A2).

[0081] [Chemical formula 2]

[0082]

[0083] (In formula (A2), Y 2 R is a group having an alkali-metallated phenolic hydroxyl group or a group having a conjugated anion of a sulfonic acid, and * represents the bonding position between the structural unit (A2) and other structural units. 15 ~R 17 are each independently a hydrogen atom or a monovalent substituent, or R 16 is a hydrogen atom or a monovalent substituent, R 15 and R 17 Together they form a divalent substituent. )

[0084] R 15 ~R 17 One or more atoms may be hydrogen atoms, or all of them may be hydrogen atoms.

[0085] In R 15 ~R 17In the case of a monovalent substituent, the monovalent substituent may be a monovalent organic group. The number of carbon atoms in the organic group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. As the organic group, monovalent substituents such as hydrocarbon groups, groups having a chemical structure formed by replacing one or more carbon atoms (methylene) of the hydrocarbon group with a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-, and groups having a heterocyclic ring may be cited. In addition, the above-mentioned monovalent substituent may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As a substituent, for example, a halogen atom may be cited. The above-mentioned hydrocarbon group is not particularly limited, and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As an aliphatic hydrocarbon group, it may be any one of a straight-chain hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any one of a saturated hydrocarbon group and an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, and a phenyl group.

[0086] About R 15 ~R 17 The monovalent substituent may have an electron withdrawing group or may be the electron withdrawing group itself. The electron withdrawing group may be bonded to the above-mentioned monovalent organic group or the above-mentioned monovalent organic group may be an electron withdrawing group. Examples of the electron withdrawing group include halogen atoms, sulfonic acid groups or their salts, sulfonic acid esters, nitro groups, nitrile groups, etc. Examples of the halogen atom include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0087] In R 15 and R 17 When a divalent organic group is formed together, the number of carbon atoms possessed by the divalent organic group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. As the organic group, a hydrocarbon group, a group having a chemical structure formed by replacing one or more carbon atoms (methylene) of the hydrocarbon group with a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-, a group having a heterocyclic ring, etc. can be listed. In addition, the above-mentioned divalent organic group may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As a substituent, for example, a halogen atom can be listed. The above-mentioned hydrocarbon group is not particularly limited, and it can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As an aliphatic hydrocarbon group, it can be any of a straight-chain hydrocarbon group, a branched hydrocarbon group and a cyclic hydrocarbon group. In addition, the hydrocarbon group can be any of a saturated hydrocarbon group and an unsaturated hydrocarbon group. As a hydrocarbon group, a propylene group, a butylene group, etc. can be listed.

[0088] In Y 2 In the case of a group having a phenolic hydroxyl group, Y 2The group may be a group represented by any of the following chemical formulae (A21) to (A26).

[0089] [Chemical formula 3]

[0090]

[0091] (In formula (A21), R A At least one of the groups is a -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which may be Li, Na or K. In formula (A22), R B At least one of the groups is a -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which may be Li, Na or K. In formula (A23), R C At least one of the groups is a -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which may be Li, Na or K. In formula (A24), R D At least one of the groups is a -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which may be Li, Na or K. In formula (A25), R E At least one of the groups is a -OM group, and the rest are hydrogen atoms or monovalent substituents, and M is an alkali metal element, which may be Li, Na or K. In formula (A26), R F At least one of the groups is a -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.

[0092] When the polymer has a functional group of formula (A21), a -OM group may be bonded to the benzene ring of formula (A21) at the para position from the bonding site of the functional group of formula (A21) and the polymer. A3 The group may be an -OA group. A hydrogen atom, an -OA group, a methyl group, an ethyl group, or a monovalent organic group having 1 to 20 carbon atoms may be bonded independently at the meta position or the ortho position and the meta position from the above-mentioned bonding site (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.).

[0093] The groups represented by formulae (A21) to (A26) may have 1 to 3 -OM groups, 1 or 2 -OM groups, or 1 -OM group.

[0094] In formulae (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 a salt thereof, a sulfonic acid ester, a nitro group, and a nitrile group. The halogen atom may be any one of F, Cl, Br, and I.

[0095] 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 possessed by the organic group may be 1 to 15, 1 to 10, 1 to 5, or 1 to 3. As the organic group, monovalent groups such as hydrocarbon groups, groups having a chemical structure formed by replacing one or more carbon atoms (methylene) of the hydrocarbon group with a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-, and groups having a heterocyclic ring may be listed. In addition, the above-mentioned monovalent group may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As the substituent, for example, a halogen atom may be listed. The above-mentioned hydrocarbon group is not particularly limited, and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any one of a straight-chain hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any one of a saturated hydrocarbon group and an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, and a phenyl group. The monovalent organic group may itself be an electron withdrawing group.

[0096] In Y 2 In the case of a group having a conjugated anion of a sulfonic acid, Y 2 , and examples thereof include groups represented by the following formula (A3).

[0097] [Chemical formula 4]

[0098]

[0099] (In formula (A3), R 19 is a covalent bond or a divalent organic group. M is an alkali metal element, which can be Li, Na or K, or Li. )

[0100] In formula (A3), the number of carbon atoms possessed by the divalent organic group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. As the organic group, there may be listed divalent substituents such as hydrocarbon groups, groups having a chemical structure in which one or more carbon atoms (methylene) of the hydrocarbon group are substituted by a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-, and groups having a heterocyclic ring. In addition, the above-mentioned divalent organic group may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As the substituent, for example, a halogen atom may be listed. The above-mentioned hydrocarbon group is not particularly limited, and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it may be any one of a straight-chain hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any one of a saturated hydrocarbon group and an unsaturated hydrocarbon group. As the hydrocarbon group, methylene, phenylene, etc. may be listed.

[0101] Examples of the group having a conjugated anion of sulfonic acid include -SO3M, -CH2-SO3M, and -C6H4-SO3M.

[0102] Functional group (B) is a functional group having a function as an anion receptor. Anion receptor refers to a chemical species that captures anions by forming electrostatic interactions, hydrogen bonds, acid-base complexes, etc. with anions. Functional group (B) captures the counter anion of the metal ion in the metal salt, promotes the dissociation of the counter anion and the metal ion. Thus, the mobility of the metal ion is increased. In addition, since the counter anion is captured by the polymer via the structural unit (B), the mobility of the counter anion is reduced. It is believed that the migration number of the metal ion is improved as a result. In addition, since the mobility of the metal ion increases, there is a tendency that the conductivity of the metal ion is also improved.

[0103] The low molecular chemical species (compound etc.) that known as anion receptor performs function, as this material, for example, can enumerate the compound of record in U.S. Patent No. 6022643 specification, U.S. Patent No. 5705689 specification, U.S. Patent No. 6120941 specification etc. Functional group (B) has the structure corresponding to the chemical species that performs function as anion receptor. Because this functional group is fixed on polymer, therefore different from existing low molecular anion receptor, the negatively charged ion that is caught can be fixed on the structure of polymer. Therefore, it is believed that it can more effectively suppress the electric current that its participation in the migration of this negatively charged ion is produced.

[0104] It should be noted that the counter anion of the alkali metal salt does not need to be a completely ionized free anion when captured by the functional group, and can be captured by interacting with the functional group in a state of forming an ionic bond or an ion pair with the metal ion.

[0105] The functional group having the function as an anion receptor may be Lewis acidic. In this case, the functional group can capture anions by accepting the non-shared electron pair of anions and forming an acid-base complex. As such functional groups, functional groups with electron-deficient atoms may be listed. It should be noted that electron-deficient atoms refer to atoms that have been covalently bonded to other atoms but whose outermost electrons do not form an octet. As electron-deficient atoms, atoms belonging to the 13th group of the periodic table may be listed, more specifically, at least one of aluminum and boron, or boron.

[0106] In addition, as a functional group having a function as an anion receptor, a group having an azaether moiety may be used. The group having an azaether moiety is a group having an azaether compound as a substituent, wherein the azaether compound is obtained by replacing -O- of an ether compound with -NR E -(Here, R E The azaether moiety may be any one of a chain azaether moiety and a cyclic azaether moiety, and may have both a chain azaether moiety and a cyclic azaether moiety. The group having the azaether moiety may have an electron withdrawing group in, for example, a hydrocarbon moiety.

[0107] The functional group (B) may be included in, for example, a structural unit (B) represented by the following formula (B).

[0108] [Chemical formula 5]

[0109]

[0110] (In formula (B), W is a functional group having a function as an anion receptor, R 1 ~R 3 are each independently a hydrogen atom or a monovalent substituent, or R 3 is a hydrogen atom or a monovalent substituent, R 1 and R 2 Together they form a divalent organic group. * indicates the position where the structural unit (B) is bonded to other structural units.

[0111] The polymer having an ability to preferentially conduct metal ions may contain one or two or more structural units represented by formula (B).

[0112] R 1 ~R 3 One or more of them may be hydrogen atoms, or all of them may be hydrogen atoms. W may be a group represented by formula (B1) described later.

[0113] In R 1 ~R 3In the case of a monovalent substituent, the monovalent substituent may be a monovalent organic group. The number of carbon atoms in the organic group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. As the organic group, monovalent substituents such as hydrocarbon groups, groups having a chemical structure formed by replacing one or more carbon atoms (methylene) of the hydrocarbon group with a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-, and groups having a heterocyclic ring may be cited. In addition, the above-mentioned monovalent substituent may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As a substituent, for example, a halogen atom may be cited. The above-mentioned hydrocarbon group is not particularly limited, and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As an aliphatic hydrocarbon group, it may be any one of a straight-chain hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. In addition, the hydrocarbon group may be any one of a saturated hydrocarbon group and an unsaturated hydrocarbon group. Examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, and a phenyl group.

[0114] It should be noted that, in the present specification, an aromatic hydrocarbon group is a group including an aromatic part and may have an aliphatic part. In addition, in the present specification, a cyclic hydrocarbon group is a group including a cyclic hydrocarbon part and may include a linear or branched hydrocarbon part.

[0115] The monovalent substituent may have an electron withdrawing group, or may be the electron withdrawing group itself. The electron withdrawing group may be bonded to the above-mentioned monovalent organic group, or the above-mentioned monovalent organic group may be an electron withdrawing group. 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. may be listed. As the halogen atom, any one of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom may be mentioned.

[0116] In R 1 and R 2 When forming a divalent organic group together, the number of carbon atoms possessed by the divalent organic group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. As the organic group, there can be listed divalent substituents such as hydrocarbon groups, groups having a chemical structure formed by replacing one or more carbon atoms (methylene) of the hydrocarbon group with a connecting group of -O-, -S-, -C(=O)- or -C(=O)O-, and groups having a heterocyclic ring. In addition, the above-mentioned divalent organic group may have a substituent that replaces the hydrogen atom bonded to the carbon atom. As the substituent, for example, a halogen atom can be listed. The above-mentioned hydrocarbon group is not particularly limited, and it can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, it can be any of a straight-chain hydrocarbon group, a branched hydrocarbon group and a cyclic hydrocarbon group. In addition, the hydrocarbon group can be any of a saturated hydrocarbon group and an unsaturated hydrocarbon group. As the hydrocarbon group, propylene and butylene can be listed.

[0117] W preferably has a group represented by the following formula (B1).

[0118] [Chemical formula 6]

[0119]

[0120] (In formula (B1), W B is an atom belonging to Group 13 of the periodic table, R 5 is a covalent bond or a divalent organic group, R 6 and R 7 is a hydrogen atom, an -OH group, a halogen atom or a monovalent organic group, or together forms a divalent organic group. 6 and R 7 They can be the same group or different groups.)

[0121] W B At least one of aluminum and boron may be used, or boron may be used.

[0122] In R 5 In the case of a divalent organic group, the number of carbon atoms possessed by the divalent organic group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. Examples of the organic group include monovalent substituents such as a hydrocarbon group, a group having a chemical structure in which one or more carbon atoms (methylene) of the hydrocarbon group are substituted by a connecting group such as -O-, -S-, -C(=O)- or -C(=O)O-, and a group having a heterocyclic ring. In addition, the above-mentioned divalent organic group may have a substituent that replaces the hydrogen atom bonded to the 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 a salt thereof, a sulfonic acid ester, a nitro group, a nitrile group, and the like. As the halogen atom, it may be any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 5 It may be a hydrocarbon group, a halogen-substituted hydrocarbon group, or a hydrocarbon group or a halogen-substituted hydrocarbon group connected to W by an ether bond. B The halogen-substituted hydrocarbon group may be a group in which a part or all of the hydrogen atoms in the hydrocarbon group are substituted with halogen atoms, or may be a partially fluorine-substituted hydrocarbon group or a fully fluorine-substituted hydrocarbon group. 5 It can also be a covalent bond.

[0123] In R 6 or R 7 In the case of a halogen atom, it may be any of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.

[0124] In R 6 or R 7In the case of a monovalent organic group, the number of carbon atoms possessed by the monovalent organic group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. Examples of the organic group include hydrocarbon groups, groups having a chemical structure in which one or more carbon atoms (methylene) of the hydrocarbon group are substituted by a connecting group such as -O-, -S-, -C(=O)- or -C(=O)O-, and groups having a heterocyclic ring. In addition, the above-mentioned monovalent organic group may have a substituent that replaces the hydrogen atom bonded to the carbon atom. The substituent may be an electron-withdrawing group. Examples of the electron-withdrawing group include halogen atoms, sulfonic acid groups or salts thereof, sulfonic acid esters, nitro groups, nitrile groups, and the like. As the halogen atom, it may be any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 6 or R 7 It may be a hydrocarbon group, a halogen-substituted hydrocarbon group, or a hydrocarbon group or a halogen-substituted hydrocarbon group connected to W by an ether bond. B The halogen-substituted hydrocarbon group may be a group in which a part or all of the hydrogen atoms in the hydrocarbon group are substituted with halogen atoms, or may be a partially fluorine-substituted hydrocarbon group or a fully fluorine-substituted hydrocarbon group.

[0125] W may be a group represented by the following formula (B1a) or a group represented by the following formula (B1b).

[0126] [Chemical formula 7]

[0127]

[0128] (In formula (B1a), X 1 and X 2 Each is an oxygen atom (ether bond) or a covalent bond, R 11 and R 12 Each of them is a halogen atom, a monovalent hydrocarbon group, a hydrogen atom or a monovalent halogen-substituted hydrocarbon group, and may be a halogen atom (except when X is an oxygen atom), a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group, or R 11 and R 12 At least one of them is a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group. 11 and R 12 They can be the same group or different groups.)

[0129] [Chemical formula 8]

[0130]

[0131] (In formula (B1b), X 3 and X 4 Each is an oxygen atom (ether bond) or a covalent bond, R 13 is a divalent hydrocarbon group or a divalent halogen-substituted hydrocarbon group.)

[0132] In formula (B1a), R 11 When X is a halogen atom, 1 Can be a covalent bond, in R 12 When X is a halogen atom, 2 It can be a covalent bond. 11 or R 12 In the case of a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group, the number of carbon atoms possessed by the monovalent hydrocarbon group or the monovalent halogen-substituted hydrocarbon group may be 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. The halogen-substituted hydrocarbon group may be a group obtained by replacing a part or all of the hydrogen atoms possessed by the hydrocarbon group with halogen atoms, or may be a partially fluorinated hydrocarbon group or a fully fluorinated hydrocarbon group.

[0133] R 11 and R 12 Each independently represents -F, -CH3, -C2H5, -C3H7, -C6H5 (phenyl), -C6H n F 5-n (n is an integer of 0 to 4, and may be an integer of 0 to 3.), -CF3, -CH2CF3, -CH2CF3CF7, -CH(CF3)2, -C(CF3)2-C6H5, -C(CF3)3, -C6H n (CF3) 5-n (n is an integer from 0 to 4, and may be 1 or 2.)

[0134] In formula (B1b), the number of carbon atoms possessed by the divalent hydrocarbon group or the divalent halogen-substituted hydrocarbon group may be 1 to 20, 1 to 15, 2 to 10, or 3 to 8. The halogen-substituted hydrocarbon group may be a group obtained by replacing a part or all of the hydrogen atoms possessed by the hydrocarbon group with halogen atoms, or may be a partially fluorinated hydrocarbon group or a fully fluorinated hydrocarbon group.

[0135] R 13 Examples include -C2H4-, -C3H6-, -C4H8-, -C5H 10 -、-C6H 12 -、-C7H 14 -、-C8H 16 -、-C9H 18 -、-C 10 H 20 -, etc., groups obtained by replacing part or all of their hydrogen atoms with fluorine, etc. More specifically, -C(CH3)2-C(CH3)2- is preferred.

[0136] The molar ratio m of the structural unit (B) to all structural units contained in the polymer may be 0.2 to 0.8, 0.25 to 0.75, 0.3 to 0.7, 0.35 to 0.65, or 0.4 to 0.6.

[0137] The molar ratio n of the structural unit (A) to all structural units contained in the polymer may be 0.25 to 0.75, 0.3 to 0.7, 0.35 to 0.65, or 0.4 to 0.6.

[0138] There is no problem if the sum of m and n is 1 or less, and may be 0.95 or less. In addition, the sum of m and n may be 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, or 0.95 or more.

[0139] The content of the structural unit (A) may be 5 to 90% by mass, 20 to 80% by mass, 40 to 75% by mass, or 55 to 70% by mass based on the total mass of the polymer.

[0140] The content of the structural unit (B) relative to the total mass of the polymer may be 10 to 95 mass %, 15 to 95 mass %, 20 to 95 mass %, 20 to 80 mass %, 25 to 60 mass %, or 30 to 45 mass %.

[0141] The total content of the structural unit (A) and the structural unit (B) may be 50% by mass or more, 70% by mass or more, 90% by mass or more, or 95% by mass or more relative to the total mass of the polymer.

[0142] The polymer may contain a structural unit different from either the structural unit (A) or the structural unit (B), that is, a structural unit (C). Examples of the structural unit (C) include the structural unit represented by the following structural unit (C1) and the structural unit represented by the following structural unit (C2).

[0143] [Chemical formula 9]

[0144]

[0145] (In formula (C1), R 21 ~R 24 Each is independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. * indicates the position where the structural unit (C1) is bonded to another structural unit. )

[0146] [Chemical formula 10]

[0147]

[0148] (In formula (C2), R 25 is a divalent organic group having 1 to 20 carbon atoms, R 26 and R 27 Each is a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms. 25 It can form a ring having an ethylene unit of formula (C2) and an imide group (succinimide ring or its N-derivative) or a ring having an acid anhydride group (succinic anhydride ring).

[0149] R 21 ~R 24 One or more of the 1 ... 1 -R 29 The group shown. 21 ~R 24 The number of carbon atoms each has may be 1 to 40, 1 to 20, 2 to 15, or 4 to 13. 1 is a divalent linking group, for example, a covalent bond, -O-, -S-, -C(=O)-, -C(=O)O-, -OC(=O)-, -C(=O)NR 38 -or-NR 39 C(=O)-. 1 In the case of a covalent bond, -O-, -S-, -C(=O)-, -C(=O)O- or -OC(=O)-, R 29 is a hydrogen atom or a monovalent organic group. 38 -In the case of R 29 , R 38 Each is a hydrogen atom or a monovalent organic group, or R 29 With R 38 Together they form a ring. 39 In the case of C(=O)-, R 29 and R 39 are each independently a hydrogen atom or a monovalent organic group, or R 29 With R 39 Together they form a ring. As R 29 , R 38 and R 39 The monovalent organic group of R may have 1 to 20 or 1 to 10 organic groups. 38 When Z is a monovalent organic group, it may be a monovalent hydrocarbon group having 1 to 20 carbon atoms. 1 In the case of a covalent bond or -C(=O)O-, R29 It may be a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. 1 is a covalent bond and R 29 When it is a hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group. 29 It may be a monovalent organic group other than a hydrocarbon group or a hydrocarbon group having a ring structure. 1 When it is -O-, it may be a monovalent organic group other than the group represented by WH when W is an alkyl ether. 26 ~R 28 When it is a monovalent organic group, examples of the monovalent organic group include the following: 25 The same groups as those listed in the examples.

[0150] In addition, the structural unit (C) may include a structural unit that is a precursor of the structural unit (A) (also referred to as a structural unit (Ap). Such structural units include unreacted structural units that cannot be converted into the structural unit (A) among the structural units that are precursors of the structural unit (A) (for example, structural units derived from the monomer (A2') described later), and intermediate structural units, for example, groups that are conjugate acids of the structural unit (A) (i.e., groups that replace the alkali metal ions that are the counter cations of the structural unit (A) with H + The counter cation contained in the structural unit (Ap) can be NH4 + , organic ammonium cations, metal ions such as alkaline earth metal ions, etc. The polymer may 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).

[0151] The polymer may include a structural unit derived from a hydrocarbon compound having a plurality of ethylenically unsaturated groups, such as butadiene and isoprene.

[0152] The polymer may 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.

[0153] The number average molecular weight (Mn) of the polymer may be 5,000 to 200,000, 8,000 to 120,000, or 10,000 to 100,000. The weight average molecular weight (Mw) of the polymer may be 5,000 to 300,000, 10,000 to 250,000, or 20,000 to 100,000. The molecular weight distribution (Mw / Mn) of the polymer may be 1.0 to 3.5, or 1.3 to 2.7. The number average molecular weight and weight average molecular weight of the polymer may be measured, for example, by gel permeation chromatography.

[0154] The content of the polymer in the electrolyte composition may be 1 to 40% by mass, 2 to 30% by mass, or 4 to 20% by mass.

[0155] The content of the polymer in the electrolyte composition may be 1 to 50% by volume, 5 to 40% by volume, or 10 to 35% by volume.

[0156] The method for producing the polymer is not particularly limited, and examples thereof include a method of polymerizing a monomer (monomer mixture) comprising at least one of the following monomers: a monomer having an anionic functional group ionized by an alkali metal or a monomer having a precursor of the anionic functional group (hereinafter referred to as monomer (A').), and a monomer (B') having a functional group having a function as an anion receptor. The monomer may further include a monomer (C') different from the monomer (A') and the monomer (B').

[0157] Monomer (A') and monomer (B') may have an ethylenically unsaturated group. In this case, monomer (A') and monomer (B') may be polymerized by free radical addition polymerization. In this case, the monomers may be polymerized in the presence of an initiator. That is, the polymerization reaction may be carried out with a polymerizable composition comprising a monomer and an initiator.

[0158] The monomer (A') is a monomer from which the structural unit (A) is derived in the polymer. Examples of the monomer (A') include a monomer (A1') represented by the following formula (A1') and a monomer (A2') represented by the following formula (A2').

[0159] [Chemical formula 11]

[0160]

[0161] (X, Y and M of formula (A1') + Synonymous with formula (A1).

[0162] [Chemical formula 12]

[0163]

[0164] (In formula (A2'), R 15 ~R 17 R of formula (A2) 15 ~R 17 Synonymous, Y 2 ' is a compound that can be derived from Y in formula (A2) 2 The phenolic hydroxyl group corresponding to the -OM group possessed by the 2 The -SO3M group has a sulfonic acid group corresponding to the group. )

[0165] Y 2 ' can be used with Y 2 The same group may also be 2 That is, Y 2 'For the desired Y 2 A group having a group convertible into an -OM group or -SO3M group at the same position as the -OM group or -SO3M group.

[0166] As a derivative of Y 2 The group of the phenolic hydroxyl group corresponding to the -OM group possessed by the present invention may be, for example, a hydrolyzable group, which can be hydrolyzed to form a phenolic hydroxyl group with Y. 2 A phenolic hydroxyl group is introduced into the position corresponding to the -OM group. Examples of the hydrolyzable group include an alkoxide group or -OSi(R k )3 base (R k The phenolic hydroxyl group can be converted into an -OM group by reacting with a basic salt of an alkali metal such as MOH, M2CO3, or MHCO3.

[0167] Similarly, as a derivative of Y 2 The group of the sulfonic acid group corresponding to the -SO3M group possessed may include, for example, a sulfonic acid ester group, a -SO2Cl group, and the like, which are groups capable of deriving a sulfonic acid group (-SO3H). The sulfonic acid group may be converted into an -OM group by, for example, reacting with a salt of an alkali metal such as MOH, M2CO3, MHCO3, or an alkali metal halide. In addition, the -SO2Cl group may also be converted into an -SO3M group by reacting with MOH. In the case of using an excess of MOH, almost all of the -SO2Cl groups may also be converted into -SO3M groups. In this reaction, there is also a case where a portion of the -SO2Cl group forms an -SO3H group. Regarding the -SO3H group, it may be separately reacted with a base containing M to form an -SO3M group. In addition, Y 2 ' can be a 2The same anion part and a group that forms a salt with a cation other than an alkali metal ion. In this case, the structural unit (A2) can be derived by subjecting the obtained polymer to a cation exchange reaction. 2 'Reaction rate (Y 2 ' is converted into Y 2 The ratio) can be 85 mol% or more, 90 mol% or more, or 95 mol% or more.

[0168] The monomer (B') is a monomer from which the structural unit (B) is derived in the polymer. Examples of the monomer (B') include monomers (B') represented by the following formula (B').

[0169] [Chemical formula 13]

[0170]

[0171] (Where R 1 ~R 3 and W and R in formula (B) 1 ~R 3 Synonymous with W. )

[0172] The free radical polymerization initiator may be any one of a thermal initiator and a photoinitiator. For example, as a thermal initiator, 2,2-azobis(isobutyronitrile) (AIBN); 2,2-azobis(2-methylbutyronitrile) (AMBN), 2,2-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1-azobis(1-cyclohexanenitrile) (ACHN, V-40), dimethyl-2,2-azobisisobutyrate (MAIB) and other azo initiators; dibenzoyl peroxide, di-8,5,5-trimethylhexanoyl peroxide, dilauroyl peroxide, didecanoyl peroxide, di(2,4-dichlorobenzoyl) and other organic peroxides may be listed. As a photoinitiator, oxime compounds, metallocene compounds, acylphosphine compounds, aminoacetophenone compounds and the like may be listed. One or more initiators may be used.

[0173] [Organic solvents]

[0174] The organic solvent may be an aprotic solvent, and for example, may be at least one selected from the group consisting of carbonate-based solvents, fluorine-based solvents, and ether-based solvents.

[0175] As carbonate solvents, chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate can be listed. As ether solvents, cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, and 1,3-dioxolane can be listed; chain ethers such as 1,2-diethoxyethane and ethoxymethoxyethane can be listed. As fluorine solvents, hydrofluorocarbons such as perfluorooctane can be listed; hydrofluoroethers such as methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether, and hydrofluoroolefins such as 1,3,3,3-tetrafluoropropylene can be listed. In addition, as solvents, aprotic solvents such as dimethyl sulfoxide (DMSO); amide solvents such as dimethylformamide (DMF) and dimethylacetamide (DMA) can be listed. The organic solvent can be used alone or as a mixed solvent containing two or more organic solvents.

[0176] When a mixed solvent is used, for example, the organic solvent may be a mixed solvent containing two or more carbonate-based solvents, a mixed solvent containing two or more cyclic carbonates, or a mixed solvent containing ethylene carbonate and propylene carbonate.

[0177] The content of the organic solvent may be 1 to 45% by mass, 4 to 40% by mass, or 7 to 30% by mass relative to the total amount of the electrolyte composition.

[0178] The content of the organic solvent may be 1 to 70% by volume, 4 to 60% by volume, or 20 to 50% by volume relative to the total amount of the electrolyte composition. The mass ratio of the polymer to the organic solvent in the electrolyte composition may be 1:0.5 to 1:3, or 1:1 to 1:2.5. In the electrolyte composition, the polymer may swell due to the solvent containing the organic solvent. The electrolyte composition may be in a gel state.

[0179] The electrolyte composition may further include a metal salt in addition to the above-mentioned polymer. The metal salt may be at least one of an alkali metal salt and an alkaline earth metal salt, or may be an alkali metal salt. The alkali metal salt is not particularly limited, and the alkali metal is denoted as M, and examples thereof include MF, MCl, MBr, MI, MClO4, MPF6, MBF4, M2SO4, M[(C h F 2h+1 )SO3](h is 0~3), M[(C h F 2h+1 )SO2]2N (h is 0 to 3), etc. In the case where the polymer has a structural unit (A), M can be an alkali metal element that is the same as the alkali metal element possessed by the structural unit (A). M can be lithium, sodium or potassium, or lithium. In addition, in the case where the polymer has a functional group (B), the electrolyte composition can contain an alkali metal salt.

[0180] The electrolyte composition can be made into a composite further comprising other resins such as fluorine resins (resins other than polymers having the ability to preferentially conduct metal ions), cloths such as non-woven fabrics, porous materials, viscosity regulating materials, etc. As a fluorine resin, it is preferably a resin having a carbon chain as a main chain. The carbon chain can be formed by free radical polymerization of ethylenically unsaturated groups. As fluororesins, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), etc. can be listed. Relative to the total amount of the electrolyte composition, the content of other resins in the electrolyte composition can be 30% by mass or less, or 0.1 to 20% by mass, or 1 to 15% by mass, or 1 to 10% by mass.

[0181] Relative to the total amount of the electrolyte composition, the total amount of the ion-conductive inorganic solid electrolyte, the polymer having the ability to preferentially conduct metal ions, and the organic solvent in the electrolyte composition can be 70% by mass or more, or 80% by mass or more, or 90% by mass or more, or 95% by mass or more, or 97% by mass or more, or 99.9% by mass or less, or 99% by mass or less. In addition, relative to the total amount of the electrolyte composition, the total amount of the ion-conductive inorganic solid electrolyte, the polymer having the ability to preferentially conduct metal ions, and the organic solvent in the electrolyte composition can be 70 to 99.9% by mass, or 80 to 99% by mass.

[0182] The total amount of the ion-conductive inorganic solid electrolyte, the polymer having the ability to preferentially conduct metal ions, and the organic solvent in the electrolyte composition may be 70% by volume or more, 80% by volume or more, 90% by volume or more, 95% by volume or more, 97% by volume or more, 99.9% by volume or less, or 99% by volume or less, relative to the total amount of the electrolyte composition. In addition, the total amount of the ion-conductive inorganic solid electrolyte, the polymer having the ability to preferentially conduct metal ions, and the organic solvent in the electrolyte composition may be 70 to 99.9% by volume, or 80 to 99% by volume, relative to the total amount of the electrolyte composition.

[0183] The migration number of the metal ions of the electrolyte composition at room temperature (25° C.) may be 0.4 or more, 0.5 or more, 0.6 or more, or 0.7 or more. The migration number may be that of an alkali metal ion or an alkaline earth metal ion, an alkali metal ion, or a lithium ion.

[0184] Relative to Li / Li +, the oxidation potential of the electrolyte composition may be 4.0 or more.

[0185] The ion conductivity of the electrolyte composition of this embodiment at 25°C can be 10 -4 S / cm or more.

[0186] The electrolyte composition of this embodiment tends to be highly flexible. For example, the dynamic hardness DH calculated from the test results of the electrolyte composition of this embodiment at 25°C using a nanoindenter according to the following formula can be 10 3 N / mm 2 Below, it can also be 8.0×10 2 N / mm 2 Below, it can also be 6.0×10 2 N / mm 2 Below, it can also be 5.0×10 2 N / mm 2 Below. The test force reaching a preset indentation depth h can be measured by the measurement of the nanoindenter, and the indentation depth based on the preset test force can also be measured. As a measurement sample of the nanoindenter, for example, a sheet sample with a diameter of 1.5 cm obtained by compression molding 150 mg of the electrolyte composition at a pressure of 200 MPa can be obtained. It should be noted that the value of the dynamic hardness DH can be obtained by taking the average value of the test results of multiple points (e.g., 5 points) measured in a non-overlapping manner.

[0187] DH=α×F / h 2 ×10 3

[0188] α=3.8584:Constant based on the shape of the indenter

[0189] F: Test force (mN)

[0190] h: Pressing depth

[0191] The electrolyte composition of this embodiment is tested using a nanoindenter at 25° C. The dynamic hardness DH calculated from the above formula is 10 3 N / mm 2 The following may contain a polymer capable of preferentially conducting metal ions and an organic solvent, and may further contain an ion-conductive inorganic solid electrolyte.

[0192] The electrolyte composition of the present embodiment can be used as a constituent material of electrochemical devices such as capacitors and batteries, for example, it can be used as a material for the electrolyte of a battery. The electrolyte can be formed by press-molding the electrolyte composition. As batteries, batteries such as lithium ion batteries and sodium ion batteries that are charged and discharged by the migration of alkali metal ions can be listed. The battery can be a primary battery, a secondary battery, or an all-solid-state battery. The electrolyte composition of the present embodiment can be a non-liquid electrolyte composition such as a solid electrolyte composition.

[0193] The battery of the present embodiment comprises a positive electrode, a negative electrode, and an electrolyte disposed between the positive electrode and the negative electrode. The electrolyte may comprise an electrolyte composition of the present embodiment. For example, in the case of a lithium ion battery, the positive electrode is not particularly limited and may be a positive electrode comprising a positive electrode active material and, as required, a conductive aid, a binder, etc.

[0194] The positive electrode may be formed by forming a layer containing these materials on the current collector. Examples of positive electrode active materials include lithium (Li) and at least one transition metal selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, Cu, and Al. Examples of such lithium composite metal oxides include LiCoO2, LiNiO2, LiMn2O4, Li2MnO3, LiNi x Mn y Co 1-x-y O2[0 <x+y<1])、LiNi x Co y Al 1-x-y O2[0 <x+y<1])、LiCr 0.5 Mn 0.5 O2, LiFePO4, Li2FeP2O7, LiMnPO4, LiFeBO3, Li3V2(PO4)3, Li2CuO2, Li2FeSiO4, Li2MnSiO4, etc.

[0195] The negative electrode of the lithium ion battery is not particularly limited, and may be a negative electrode containing a negative electrode active material and, if necessary, a conductive auxiliary agent, a binder, etc. For example, single substances of elements such as Li, Si, P, Sn, Si-Mn, Si-Co, Si-Ni, In, Au, and alloys or composites containing these elements, carbon materials such as graphite, and materials with lithium ions inserted between the layers of the carbon materials, etc. may be cited.

[0196] The lithium ion battery may have a separator. The separator may be a porous material or a porous material made of resin. Specifically, porous polyolefin membranes, porous ceramic membranes, etc. may be mentioned.

[0197] As a manufacturing method of the battery of this embodiment, for example, there may be a process of preparing an electrolyte composition (battery coating agent) and a process of pressurizing the electrolyte composition to manufacture an electrolyte. The manufactured electrolyte is arranged between the positive electrode and the negative electrode. Pressurization can be performed by placing the electrolyte composition on the negative electrode or the positive electrode or between the positive electrode and the negative electrode. Since pressurization inhibits the evaporation of the organic solvent, it is preferably performed at a temperature lower than the boiling point of the organic solvent used (the lowest boiling point of the component solvents in the case of a mixed solvent), and can be performed below 50°C or at room temperature (25°C). The pressure during pressurization can be, for example, 10 to 300 MPa or 100 to 250 MPa. Pressurization can be performed at 10°C to 60°C, 20°C to 50°C. The process of preparing the electrolyte composition can be performed by mixing the raw materials of the electrolyte composition, i.e., the ion-conductive inorganic solid electrolyte, the polymer having the ability to preferentially conduct metal ions, and the organic solvent, and each component of the optional components as required, with a mortar or the like. The ion-conductive inorganic solid electrolyte may be subjected to an acid treatment before being mixed with other components.

[0198] Example

[0199] [Manufacturing of polymers having the ability to preferentially conduct metal ions]

[0200] A copolymer of the monomer A1 represented by the following formula and styrene (in a molar ratio of 54:46) was produced as follows.

[0201] [Chemical formula 14]

[0202]

[0203] First, monomer A1 was produced as follows.

[0204] (Synthesis of Monomer A1)

[0205] Under 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., Ltd.). To the solution, 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 added in sequence 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 washed with dichloromethane (manufactured by Kanto Chemical Co., Ltd.) to obtain Intermediate 1. The yield was 97.1%.

[0206] The structural formula of intermediate 1:

[0207] [Chemical formula 15]

[0208]

[0209] Under nitrogen atmosphere, 5% hydrochloric acid (22.5 mL) was added to intermediate 1 (15 mmol, 5.28 g), and stirred at 90°C for 2 hours. After cooling to room temperature, lithium hydroxide aqueous solution was added until the pH reached 7 or above based on the confirmation of pH test paper, and then a solid was obtained by drying under reduced pressure. The obtained solid was extracted with acetonitrile solution and dried under reduced pressure to obtain intermediate 2. The yield was 92.6% based on the raw material of the above intermediate 1.

[0210] The structural formula of intermediate 2:

[0211] [Chemical formula 16]

[0212]

[0213] 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., Ltd.) under a nitrogen atmosphere. A solution of all intermediate 2 (13.2 mmol, 4.09 g) prepared under a nitrogen atmosphere in dehydrated tetrahydrofuran (26.4 mL, manufactured by Kanto Chemical Co., Ltd.) was added dropwise to the solution, and 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.

[0214] The structural formula of intermediate 3:

[0215] [Chemical formula 17]

[0216]

[0217] Under nitrogen atmosphere, 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 anhydrous acetic acid (12.3 mL, manufactured by Tokyo Chemical Industry Co., Ltd.) and stirred at 70°C for 3 hours. The entire solution after the reaction was added dropwise to an excess of diethyl ether (manufactured by Kanto Chemical Co., Ltd.) at 0°C, and the precipitate was recovered by filtration. Under an inert atmosphere, the precipitate was extracted with dehydrated acetonitrile (manufactured by Kanto Chemical Co., Ltd.) and dried under reduced pressure to obtain monomer A1. The overall yield of all steps was 72.8%.

[0218] The monomer A1: 3.121 g, styrene: 0.833 g, and AIBN: 57.5 mg were dissolved in 70 mL of dehydrated acetonitrile, and tetralin was added as an internal standard substance. The reaction was carried out at 60°C under a nitrogen atmosphere for 24 hours while confirming the monomer consumption rate. The polymerization solution was dialyzed in acetonitrile and vacuum dried at 120°C to obtain 3.50 g (yield 89%) of polymer. The monomer introduction ratio was A1: styrene = 54:46. The monomer introduction ratio was adjusted by the copolymer 1 H-NMR was calculated. Styrene was used by sealing a commercial reagent with a purity of >98% manufactured by Sigma-Aldrich Co. LLC with CaCl2 and drying overnight, and then adding CaH2 and performing vacuum distillation to increase the purity.

[0219] The number average molecular weight of the copolymer is Mn = 9.3 × 10 4 , weight average molecular weight Mw = 3.0 × 10 5 , molecular weight distribution Mw / Mn=3.19.

[0220] [Ion-conductive inorganic solid electrolyte]

[0221] As the ion-conductive inorganic solid electrolyte, the following was used.

[0222] LLZT powder: Li made by Toyoshima Manufacturing Co., Ltd. 6.6 Ln3Z 1.6 Ta 0.4 O 12

[0223] LATP powder: LICGC PW-01Powder manufactured by Ohara Co., Ltd.

[0224] [Manufacturing of Electrolyte Composition]

[0225] (Example 1)

[0226] The polymer having the ability to preferentially conduct metal ions manufactured as described above is mixed with an organic solvent (ethylene carbonate: propylene carbonate = 1: 1 (volume ratio)) (KISHIDA CHEMICAL Co., Ltd.) to manufacture a gel polymer composition. Next, the gel polymer composition is mixed with LLZT powder using a mortar in such a way that the content of LLZT in the electrolyte composition reaches 77% by mass, and 150 mg of the mixture is pressed and molded at a pressure of 200 MPa to obtain an electrolyte composition with a diameter of 1.5 cm. It should be noted that, with respect to LLZT powder, a substance obtained by dispersing in 2% by mass hydrochloric acid for 30 seconds before mixing with the polymer composition, filtering and drying is used.

[0227] (Example 2)

[0228] The gel polymer composition and LATP powder were mixed so that the content of LATP in the electrolyte composition was 70 mass %, and 150 mg of the mixture was press-molded at a pressure of 200 MPa to obtain an electrolyte composition having a diameter of 1.5 cm.

[0229] (Example 3)

[0230] The polymer having the ability to preferentially conduct metal ions produced as described above was mixed in an amount of 16 mass %, the LATP powder in an amount of 79 mass %, and the polytetrafluoroethylene (PTFE) in an amount of 5 mass %, and 150 mg of the mixture was compression molded at a pressure of 200 MPa to obtain a pellet molded body having a diameter of 1.5 cm. 32 mass % of an organic solvent (ethylene carbonate:propylene carbonate=1:1 (volume ratio)) (KISHIDA CHEMICAL Co., Ltd.) was infiltrated into the pellet molded body relative to 100 mass % of the pellet molded body to obtain an electrolyte composition.

[0231] (Comparative Example 1)

[0232] As the electrolyte composition of Comparative Example 1, 150 mg of LLZT powder was compacted at a pressure of 200 MPa to prepare pellets having a diameter of 1.5 cm and used.

[0233] (Comparative Example 2)

[0234] As the electrolyte composition of Comparative Example 2, 150 mg of LATP powder was compression-molded at a pressure of 200 MPa to prepare pellets having a diameter of 1.5 cm and used.

[0235] (Comparative Example 3)

[0236] A mixture of polyethylene oxide (Poly (ethylene oxide) average Mv 600000, powder) manufactured by Aldrich and lithium bis(fluorosulfonyl)imide (LiFSI) (mol ratio O atom: Li atom = 20: 1), and an organic solvent (ethylene carbonate: propylene carbonate = 1: 1 (volume ratio)) (KISHIDA CHEMICAL Co., Ltd.) was mixed to produce a gel polymer composition. Next, the gel polymer composition and LLZT powder were mixed using a mortar in such a way that the content of LLZT in the electrolyte composition reached 58% by mass, and 150 mg of the mixture was pressed and molded at a pressure of 200 MPa to obtain an electrolyte composition with a diameter of 1.5 cm.

[0237] (Comparative Example 4)

[0238] The gel polymer composition and LATP powder were mixed so that the content of LATP in the electrolyte composition was 70 mass %, and 150 mg of the mixture was press-molded at a pressure of 200 MPa to obtain an electrolyte composition having a diameter of 1.5 cm.

[0239] The ionic conductivity, direct current density, and lithium ion transference number (Li + The results are shown in Tables 1 and 2.

[0240] <Measurement of ion conductivity>

[0241] An evaluation cell of a coin-shaped battery CR2032 was assembled in a glove box under a dry argon atmosphere. Specifically, each layer was stacked in the evaluation cell in the following order to produce a test stack.

[0242] (Stainless steel plate / electrolyte composition / stainless steel plate)

[0243] The measurement was performed using an impedance measuring device at 25°C, a frequency range of 0.1 Hz to 1 MHz, and an applied voltage of 10 mV (vs. open circuit voltage). The ion conductivity σ can be calculated using the following formula.

[0244] σ(S·cm -1 )=t(cm) / (R(Ω)×A(cm 2 ))

[0245] Where R represents the impedance value, A represents the area of ​​the sample, and t represents the thickness of the sample.

[0246] <Determination of Maximum DC Current Density>

[0247] An evaluation cell of a coin-shaped battery CR2032 was assembled in a glove box under a dry argon atmosphere. Specifically, each layer was stacked in the evaluation cell in the following order to produce a test stack.

[0248] (lithium / electrolyte composition / lithium)

[0249] For the evaluation cell, 10, 20, 30, 40, 50, 100, 200, 300, and 400 μA / cm2 were applied alternately in the positive and negative directions for 10 cycles in the following order: 2 In the constant current test of the current density, the point where the voltage reaches 2V is defined as the maximum DC current density.

[0250] <Determination of lithium ion migration number>

[0251] An evaluation cell of a coin-shaped lithium battery CR2032 was assembled in a glove box under a dry argon atmosphere. Specifically, each layer was stacked in the evaluation cell in the following order to produce a test stack.

[0252] (lithium / electrolyte composition / lithium)

[0253] The method for measuring the lithium ion transference number is introduced in Polymer, 28, 2324 (1987). That is, at room temperature (25°C), 10 mV is applied to the test stack, and the initial current value (I0) and the steady-state current value (I ss ), and then the interface resistance value R0 before voltage application and the interface resistance value R after voltage application were obtained by complex impedance method. SS Then, the obtained value is introduced into the following formula to calculate the lithium ion migration number (t Li+ ). Where V is the applied voltage.

[0254] t Li+ =I ss (V-I0R0) / I0(VI SS R SS )

[0255] <Determination of Cycle Maintenance Rate>

[0256] LiNi was used in a glove box under dry argon atmosphere. 1 / 3 Co 1 / 3 Mn 1 / 3 An evaluation cell of a coin-type battery CR2032 was assembled using O2 as a positive electrode active material. Specifically, each layer was stacked in the following order in the evaluation cell to produce a test stack.

[0257] (Positive electrode / electrolyte composition / lithium)

[0258] The above evaluation cell was used at 2.5-4.3V (vs. Li / Li + ) were performed within the range of 10 cycles, and the cycle retention rate after 10 cycles was measured.

[0259] Figure 1 The results of the charge and discharge test of Example 2 are shown. Figure 2 The results of the charge and discharge test of Comparative Example 4 are shown. Figure 1 and 2 In the figure, the solid line curve is the result of the first cycle, and the dotted line curve is the result of the tenth cycle.

[0260] The capacity retention rate after 10 cycles in Example 2 is 98%, while the capacity retention rate after 10 cycles in Comparative Example 4 is 9%.

[0261] <Determination of decomposition potential>

[0262] Using the single cell used for measuring the cycle characteristics, the onset of a peak other than the charge peak is measured using a differential capacity curve.

[0263] Figure 3 is the differential capacity curve for Example 2. In addition, Figure 4 This is a differential capacity curve for Comparative Example 4. Figure 3 and Figure 4 The differential capacity curves are obtained by differentiating the capacity with respect to the curve on the charge side of the charge-discharge curve of the third cycle with respect to the voltage as a function of the voltage.

[0264] Figure 3 is the differential capacity curve of Example 2. In addition, Figure 4 This is the differential capacity curve of Comparative Example 4. In Example 2, no peak other than charging was observed in the range of 2.5-4.3V used for the cycle retention rate determination. In the differential capacity curve obtained by charging to 5.0V, since the voltage at the start of charging is around 4.0V, it was confirmed that no decomposition reaction occurred at a potential below this value, and a new peak starting from 4.5V was obtained. From the above, the decomposition potential of the electrolyte was estimated to be 4.5V.

[0265] On the other hand, Comparative Example 4 appears to have a single peak at first glance, but although the same positive electrode material is used, the peak starting position is shifted to the low potential side and the peak width increases, based on which it is judged that a peak based on component decomposition is generated, and the decomposition potential of the electrolyte is estimated to be 3.8 V. This is consistent with the reported decomposition potential of PEO.

[0266] Table 1

[0267]

[0268] Table 2

[0269]

[0270] <Determination of dynamic hardness>

[0271] The mechanical properties of the electrolyte composition were measured using a nanoindenter DUH-211 manufactured by Shimadzu Corporation. The dynamic hardness was calculated as follows based on the value of the test force F when the indentation depth h was 3 μm. The same measurement was performed at 5 discontinuous points on each sample, and the average value was calculated. The results are shown in Table 3. It should be noted that the test was performed at 25°C.

[0272] Dynamic hardness DH (N / mm 2 )

[0273] DH=α×F / h 2 ×103

[0274] α=3.8584:Constant based on the shape of the indenter

[0275] F: Test force (mN)

[0276] h: Pressing depth

[0277] Table 3

[0278]

Claims

1. An electrolyte composition, comprising: Ion-conductive inorganic solid electrolytes, A polymer having the ability to preferentially conduct metal ions, and Organic solvents, and The content of the ion-conductive inorganic solid electrolyte satisfies at least one of the following conditions: (1) 50% by mass or more relative to the total amount of the electrolyte composition; and (2) 15% by volume or more relative to the total amount of the electrolyte composition.

2. The electrolyte composition according to claim 1, wherein The ion-conductive inorganic solid electrolyte is an oxide, a sulfide, a hydride, or a halide, and contains at least one of an alkali metal element and an alkaline earth metal element.

3. The electrolyte composition according to claim 2, wherein The ion-conductive inorganic solid electrolyte is a perovskite-type oxide, a NASICON-type oxide, a LISICON-type oxide or a garnet-type oxide.

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

5. The electrolyte composition according to claim 1 or 2, wherein The transference number of the metal ion is 0.4 or more.

6. The electrolyte composition according to claim 1 or 2, wherein Oxidation potential relative to Li / Li + is 4.0V or above.

7. An electrolyte comprising the electrolyte composition according to claim 1 or 2.

8. A battery comprising the electrolyte composition according to claim 1 or 2.

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