Electrolyte composition, electrode composition, and battery

Abstract

This disclosure provides an electrolyte composition comprising a polymer, an organic solvent, and particles, wherein the polymer has side groups comprising one or more groups selected from alkali-metallized phenolic groups, alkali-metallized carboxylic acid groups, alkali-metallized sulfonic acid groups, and alkali-metallized sulfonylimide groups.

Description

Technical Field

[0001] This disclosure relates to electrolyte compositions, electrode compositions, and batteries. Background Technology

[0002] Lithium-ion batteries and similar batteries, which charge and discharge via the movement of metal ions between the positive and negative electrodes, are actively under research due to their high capacity. Electrolytes used in lithium-ion batteries and similar devices have previously been known to include solutions of lithium salts containing organic solvents or ionic liquids. However, from the viewpoints of safety and processability, research is underway on solid electrolytes, polymeric electrolytes, and the like (Patent Document 1 or 2). Furthermore, in addition to lithium-ion batteries, research has been conducted on batteries using other alkali metal ions such as sodium and potassium, which are present in greater quantities than lithium.

[0003] Existing technical documents Patent documents Patent Document 1: Korean Patent Publication No. 10-2016-0050870 Patent Document 2: Japanese Patent Publication No. 2023-511906 Summary of the Invention

[0004] The problem that the invention aims to solve In this context, electrolytes used in lithium-ion batteries and the like are required to have the characteristic of being able to carry a larger current with a smaller overvoltage. However, if a large current is to be carried in an electrolyte composition containing polymers, the overvoltage will rise sharply due to factors such as low ionic conductivity and electrolyte inhomogeneity, and there is room for improvement in this characteristic.

[0005] This disclosure was made in view of the above circumstances, and its purpose is to provide an electrolyte composition, an electrode composition, and a battery comprising the thereof capable of carrying a larger current with a smaller overvoltage.

[0006] Methods for solving problems This disclosure includes the following exemplary embodiments. [1] An electrolyte composition comprising a polymer, an organic solvent, and particles. The polymer described above has side groups, which contain one or more groups selected from alkali metallized phenolic groups, alkali metallized carboxylic acid groups, alkali metallized sulfonic acid groups, and alkali metallized sulfonylimide groups. [2] According to the electrolyte composition described in [1], the particles are nanoparticles. [3] According to the electrolyte composition described in [1] or [2], wherein the side groups comprise lithium ions or sodium ions. [4] The electrolyte composition according to any one of [1] to [3], wherein the organic solvent comprises one or more solvents selected from carbonate solvents, ether solvents, fluorinated solvents, nitrile solvents, lactone solvents and phosphate solvents. [5] The electrolyte composition according to any one of [1] to [4], wherein the side group comprises one or more groups selected from lithium phenol group, lithium carboxylic acid group, lithium sulfonic acid group and lithium sulfonyl imide group. [6] The electrolyte composition according to any one of [1] to [5] further comprises an alkali metal salt. [7] An electrolyte composition according to any one of [1] to [6], wherein the migration number is 0.5 or more. [8] The electrolyte composition according to any one of [1] to [7], wherein the particles comprise one or more selected from carbon particles, sulfur particles, silicon oxide particles, aluminum oxide particles, titanium oxide particles and organic particles. [9] The electrolyte composition according to any one of [1] to [8], wherein the content of the above-mentioned particles is 50% by mass or less relative to the total amount of the above-mentioned electrolyte composition.

[10] An electrode composition comprising any one of the electrolyte compositions described in [1] to [9].

[11] A battery comprising any one of the electrolyte compositions described in [1] to [9].

[0018] Invention Effects According to this disclosure, it is possible to provide electrolyte compositions, electrode compositions, and batteries comprising the same that can carry larger currents with smaller overvoltages. Attached Figure Description

[0019] Figure 1 This is a graph showing the relationship between the number of cycles and the voltage value in a lithium dissolution test. Detailed Implementation

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings as appropriate. However, the following embodiments are illustrative of the present disclosure and are not intended to limit the present disclosure to the following content.

[0021] (Electrolyte composition) The electrolyte composition of this embodiment contains a polymer, an organic solvent, and particles. The polymer has side groups, which include one or more groups selected from alkali-metallized phenolic groups, alkali-metallized carboxylic acid groups, alkali-metallized sulfonic acid groups, and alkali-metallized sulfonylimide groups. It should be noted that, in this specification, a group having one or more groups selected from alkali-metallized phenolic groups, alkali-metallized carboxylic acid groups, alkali-metallized sulfonic acid groups, and alkali-metallized sulfonylimide groups is also referred to as a functional group (A), and a polymer having a functional group (A) as a side group is also referred to as polymer (A).

[0022] In this specification, in any case, "substituent" can refer to organic groups and groups other than organic groups (inorganic groups).

[0023] In this specification, "organic group" refers to a group having a chemical structure obtained by removing at least one hydrogen atom from an organic compound. When referring to "organic group" in this specification, regardless of the valence of the organic group, examples include groups formed by replacing a portion of the carbon atom of a hydrocarbon group with a heteroatom, and groups in which at least one hydrogen atom of a hydrocarbon group is replaced by a substituent. When an organic group has a ring structure, the ring can be any of a heterocyclic ring and a carbocyclic ring, or any of a monocyclic ring and a fused ring.

[0024] In this specification, in any case, the hydrocarbon group may be exemplified as either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. In any case, the aliphatic hydrocarbon group may be exemplified as either a straight-chain hydrocarbon group, a branched hydrocarbon group, or a cyclic hydrocarbon group. Furthermore, in any case, the hydrocarbon group may be exemplified as either a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0025] In this specification, aromatic hydrocarbon groups are defined as hydrocarbon groups having an aromatic moiety such as a benzene ring, and may also have an aliphatic moiety. Furthermore, in this specification, cyclic hydrocarbon groups are defined as hydrocarbon groups having an aliphatic carbocyclic moiety, and may have a straight-chain or branched aliphatic moiety.

[0026] There are no particular limitations on the heteroatoms that replace the aforementioned carbon atoms; examples include boron, oxygen, nitrogen, silicon, phosphorus, and sulfur atoms. Specifically, the organic group can include linking groups containing heteroatoms, such as -O- (ether bond), -S- (thioether bond), sulfonyl, sulfinyl, secondary amino, and tertiary amino groups.

[0027] In this specification, in any case, as specific examples of organic groups, substituted or unsubstituted hydrocarbon groups may be listed; groups with a chemical structure formed by replacing one or more carbon atoms (methylene) of a hydrocarbon group with a linking group containing heteroatoms such as -O- (ether bond), -S- (thioether bond), -C(=O)- or -C(=O)O-, -C(=O)NR- (R is a monovalent organic group) (the linking group can be a divalent linking group), or groups formed by replacing the hydrogen atoms of such groups with substituents such as halogen atoms; groups with heterocycles, etc.

[0028] In this specification, in any case, as an inorganic group, either an electron-withdrawing group or an electron-donating group may be exemplified; specifically, halogen atoms, -NH2, and -NH3 may be listed. + -CN, sulfonic acid groups and their salts or esters, -NO2, etc.

[0029] <Polymers: Polymers with the ability to preferentially conduct alkali metal ions> Polymer (A) can be a polymer that preferentially conducts alkali metal ions. For a polymer to be considered a polymer with the ability to preferentially conduct alkali metal ions, it is sufficient to satisfy at least one of the following conditions (X) and (Y). The aforementioned polymer can be simply referred to as a polymer with the ability to conduct alkali metal ions.

[0030] Condition (X): When measuring the migration number of alkali metal ions at room temperature (25°C) for a composition containing 33% by mass of polymer and 67% by mass of nonionic plasticizer, the migration number of alkali metal ions is 0.4 or higher.

[0031] Condition (Y): When determining the migration number of alkali metal ions at room temperature (25°C) for a composition containing 31.9% by mass of polymer, alkali metal salt and the remaining total amount of nonionic plasticizer and an alkali metal ion concentration of 0.3 mol / L, the migration number of alkali metal ions is 0.4 or higher.

[0032] As polymer (A), the migration number of the alkali metal ion in conditions (X) and (Y) above can be, for example, 0.5 or more, 0.6 or more, or 0.7 or more. The alkali metal ion contained in the composition for which the migration number in conditions (X) and (Y) above is measured can be a countercation of the anionic functional group of the polymer. As a nonionic plasticizer, at least one of organic solvents and other resins such as fluorinated resins can be listed. The organic solvent can be an aprotic solvent. The aprotic solvent can be at least one selected from carbonate solvents, fluorinated solvents, and ether solvents. The organic solvent can be a mixed solvent of ethylene carbonate and propylene carbonate (in a volume ratio of 1:1). As a fluorinated resin, a resin having a carbon chain as the main chain is preferred. The carbon chain can be formed by free radical polymerization of olefinic unsaturated groups. The fluorinated resin can be PVDF-HFP.

[0033] Polymer (A) contains alkali-metallized groups as side groups. Here, in this specification, alkali-metallized groups refer to groups whose acidic form of the conjugate base (i.e., anionic functional group) forms a salt with an alkali metal ion. Specifically, alkali-metallized phenolic hydroxyl groups refer to -OA groups (-O groups) obtained by replacing the H of the -OH group (which is a phenolic hydroxyl group) with the alkali metal element A. - A + (e.g., lithium-ionized phenolic groups). Alkali metallized carboxylic acid groups refer to the -COOA group ([-COO) obtained by replacing the hydrogen atom of a carboxylic acid group (-COOH group) with an alkali metal element A. - A + (e.g., lithium carboxylic acid groups). Alkali metal sulfonate groups refer to the -SO3A group ([-SO3) obtained by replacing the H atom of a sulfonate group (-SO3H group) with an alkali metal element A. - A + (e.g., lithium sulfonate groups). Alkali metal sulfonamide groups refer to the -SO2-NA-SO2- group ([-SO2-N-SO2-) obtained by replacing the hydrogen atom (H) of the sulfonamide acid group (-SO2-NH-SO2-) with an alkali metal element (A). - A + (e.g., lithium sulfonyl imide group).

[0034] There are no particular restrictions on the structure of polymer (A). Examples of polymers with a carbon chain as the main chain can be listed. This carbon chain can be formed by free radical addition polymerization of monomers with olefinic unsaturated groups.

[0035] Alkali metal element A may include at least one selected from lithium, sodium, potassium, rubidium and cesium, may include at least one selected from lithium, sodium and potassium, may include at least one of lithium and sodium, and may include lithium.

[0036] The content of one alkali metal element in polymer (A) may be 80 mol% or more, 85 mol% or more, or 90 mol% or more. This alkali metal element may be potassium, sodium, or lithium, or it may be either sodium or lithium.

[0037] Polymer (A) may have structural unit (A). Structural unit (A) is a structural unit having a functional group (A), and may include at least one of the structural units shown in formula (A1) and formula (A2). It should be noted that, except for R in formula (A1)... 1 ~R 3 and structures other than Y, and in equation (A2) excluding R 4 R 5 Structures other than Z are also referred to as ethylene units.

[0038] [Chemical Formula 1] (In formula (A1), Y is a monovalent group that has been alkali-metallated and contains the functional group (A). R) 1 ~R 3 Each is independently a hydrogen atom or a monovalent substituent, or R 1 and R 2 One of them and R 3 Together they form a ring, with the other being a hydrogen atom or a monovalent substituent. R 1 ~R 3 It can have alkali-metallated groups. R 1 ~R 3 At least one of them can be a functional group other than a hydrogen atom or a fluorine atom. [Chemical Formula 2] (In formula (A2), Z is an alkali-metallized divalent group containing the functional group (A). R) 4 and R 5 Each is independently a hydrogen atom or a monovalent substituent, or R 4 and R 5 They form a ring together. R 4 and R 5 It can have alkali-metallated groups. In formula (A1), Y contains at least a functional group (A), and the functional group (A) may contain at least one of an alkali-metallized carboxylic acid group and an alkali-metallized phenolic hydroxyl group. The polymer (A) may contain one or more structural units (A) having different functional groups as Y.

[0039] In formula (A1), R 1 ~R 3When it is a monovalent substituent, the substituent can be a monovalent organic group. The number of carbon atoms in the monovalent organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. In formula (A1), R... 1 ~R 3 At least one of them can be a hydrogen atom, or all of them can be hydrogen atoms.

[0040] In formula (A1), R 1 and R 2 One of them and R 3 When they form a ring together, R 1 Or R 2 With R 3 A divalent substituent is formed, bonded to each of the two carbons of the ethylene unit in formula (A1). In formula (A2), R 4 and R 5 When they form a ring together, R 4 and R 5 Divalent substituents are formed that are bonded to the two carbon atoms of the ethylene unit of formula (A1). These rings can be any type of carbocyclic or heterocyclic ring. The number of ring members can be, for example, 4 to 10, 5 to 8, 5, or 6. Substituents can be bonded to the carbon atom or heteroatom that is a ring member.

[0041] When Y in formula (A1) contains an alkali-metallated carboxylic acid group (-COOA group, A is an alkali metal), Y can be the -COOA group itself or a monovalent organic group having the -COOA group. When Y is a monovalent organic group having the -COOA group, the number of carbon atoms in the organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. The number of carbon atoms in the above organic group includes the carbons constituting the -COOA group. A monovalent organic group having the -COOA group can have one or more -COOA groups, or it can have one -COOA group. When Y is a monovalent organic group having the -COOA group, Y can also have electron-withdrawing groups such as halogen atoms in addition to the -COOA group.

[0042] In equation (A1), Y can be -R 9 -COOA represents the group. Here, R 9 It is a divalent organic group or a covalent bond (i.e., Y is the -COOA fundamental). The number of carbon atoms in this divalent organic group can be, for example, 1 to 19, 1 to 14, 1 to 9, 1 to 4, 1, or 2. R 9 When it contains carbon atoms, R 9 It can be except R 9 The divalent groups other than those formed by replacing all carbon atoms with fluorine atoms. R 9When it contains carbon atoms, R 9 At least one of the carbon atoms contained therein is bonded to a substituent other than a hydrogen atom or a fluorine atom.

[0043] When Y in formula (A1) has an alkali-metallated phenolic hydroxyl group, Y can be, for example, R. 10 -Y 2 The group shown. Here, R 10 It can be a divalent substituent (linking group) or a covalent bond; it can be a covalent bond. Y 2 It can be a group having one or more -OA groups (A being an alkali metal element) that are directly bonded to a carbon atom that is a ring member of an aromatic ring such as a benzene ring, naphthalene ring, or anthracene ring. Other ring structures can be fused with aromatic rings. For example, Y 2 It may have a group represented by any of the following formulas (A21) to (A26).

[0044] [Chemical Formula 3] (In formula (A21), R) A1 ~R A5 At least one of the groups is an -OA group, and the rest are hydrogen atoms or monovalent substituents. R A3 The base can be -OA base.

[0045] In equation (A22), R B1~ R B7 At least one of the groups is an -OA group, and the rest are hydrogen atoms or monovalent substituents. R B3 ~R B6 At least one of the bases can be an -OA base.

[0046] In equation (A23), R C1~ R C9 At least one of the groups is an -OA group, and the rest are hydrogen atoms or monovalent substituents. R C2 ~R C8 At least one of the bases can be an -OA base.

[0047] In formula (A24), R D1~ R D6 At least one of the groups is an -OA group, and the rest are hydrogen atoms or monovalent substituents. R D3~ R D6 At least one of the bases can be an -OA base.

[0048] In formula (A25), R E1~ R E9 At least one of the groups is an -OA group, and the rest are hydrogen atoms or monovalent substituents. R E2 ~R E8 At least one of the bases can be an -OA base.

[0049] In formula (A26), R F1~ R F9 At least one of the groups is an -OA group, and the rest are hydrogen atoms or monovalent substituents. R F1~ R F9 At least one of the bases can be an -OA base. The groups shown in formulas (A21) to (A26) have at least one -OA group. The number of -OA groups can be, for example, 1 to 3, 1 or 2, and there can be 1 -OA group.

[0050] In formulas (A21) to (A26), the monovalent substituent is preferably an electron-withdrawing group. Examples of electron-withdrawing groups include halogen atoms, sulfonic acid groups or their salts, sulfonates, nitro groups, and nitrile groups. The halogen atom can be any one of F, Cl, Br, and I.

[0051] In formulas (A21) to (A26), the monovalent substituent can be an organic group having 1 to 20 carbon atoms. The number of carbon atoms in the organic group can be, for example, 1 to 15, 1 to 10, 1 to 5, or 1 to 3.

[0052] In equation (A1), Y is R 10 -Y 2 The group shown, the R 10 When the substituent is divalent, it can be a divalent organic group. The number of carbon atoms in this divalent organic group can be, for example, 1 to 15, 1 to 10, 1 to 8, or 1 to 5. R 10 It can have heterocyclic rings or rings containing imide groups.

[0053] When Y in formula (A1) is an alkali-metallized sulfonic acid group, the following formula (A3) can be used as Y to represent the group.

[0054] [Chemical Formula 4] (In formula (A3), R) 19 (It is a covalent bond or a divalent organic group. A is an alkali metal element.) In formula (A3), the number of carbon atoms in the above-mentioned divalent organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 6, 1 to 5, or 1 to 3. In formula (A3), R... 19 When the divalent organic group is a hydrocarbon group, at least one of the carbon atoms constituting the hydrocarbon group is bonded to a hydrogen atom. That is, the divalent organic group in formula (A3) is a group other than a perfluorinated hydrocarbon group.

[0055] Examples of alkali metal sulfonic acid groups represented by formula (A3) include -SO3A, -CH2-SO3A, and -C6H4-SO3A.

[0056] When Y in formula (A1) is an alkali-metallized sulfonylimide group, the group represented by the following formula (A4) can be listed as Y.

[0057] [Chemical Formula 5] (In formula (A4), R) 20 R is a covalent bond or a divalent organic group. 21 It can be a hydrogen atom or a monovalent substituent. A + (These are alkali metal ions.) R in equation (A4) 20 In the case of a divalent organic group, the number of carbon atoms in the divalent organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 6, 1 to 5, or 1 to 3.

[0058] When the polymer (A) has a structural unit (A) represented by formula (A2), in formula (A2), Z is bonded to two carbon atoms of the ethylene unit to form a ring. This ring can be any of a carbocyclic ring or a heterocyclic ring. Furthermore, the aforementioned ring can be any of aliphatic or aromatic. Examples of heterocyclic rings include maleimide rings and other rings containing imide groups. A functional group (A) can be bonded to this ring. The number of carbon atoms in Z can be, for example, 1 to 20, 1 to 15, 2 to 10, or 3 to 8.

[0059] As a structural unit (A2), it can be a group containing a maleimide ring with an alkali-metallized group, and the following structural units (A5) can be listed.

[0060] [Chemical Formula 6] (In formula (A5), X is a divalent organic group having 1 to 20 carbon atoms, Y) 1 A is a halogen atom or a monovalent organic group having 1 to 20 carbon atoms. + It is an alkali metal ion. This indicates the location where structural unit (A5) is bonded to other structural units. In formula (A5), X can have 1 to 15, 2 to 10, or 3 to 8 carbon atoms. When X is a hydrocarbon group, the hydrocarbon group can be, for example, a phenylene group, an alkylene group having 1 to 8 carbon atoms, a polyoxyalkylene group, or a group in which some or all of the hydrogen atoms bonded to the carbon atoms are replaced by halogen atoms such as fluorine atoms. It can also be a substituted phenylene group that is replaced by phenylene or alkyl groups, halogen atoms, electron-withdrawing groups, etc.

[0061] Y in equation (A5) 1 When Y is a monovalent organic group, 1 The number of carbon atoms it possesses can be, for example, 1 to 15, 1 to 10, 1 to 8, 1 to 5, or 1 to 3. Y in formula (A5) 1 When the group is a hydrocarbon group, it can be a phenyl group, an alkyl group having 1 to 5 carbon atoms, or a group in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are replaced by halogen atoms such as fluorine atoms. It can be a fluoroalkyl group having 1 to 5 carbon atoms, or a fluoroalkyl group having 1 to 3 carbon atoms such as trifluoromethyl. The fluoroalkyl group can be a perfluoroalkyl group. 1 In the case of halogen atoms, the halogen atom can be a fluorine atom or a chlorine atom, or it can be a fluorine atom.

[0062] In the case where the structural unit (A) of the polymer (A) has the structural unit represented by formula (A2), and in the case where formula (A2) contains an alkali-metallized sulfonic acid group, Z in formula (A2) can be, for example, the group represented by the following formula (A6).

[0063] [Chemical Formula 7] (In formula (A6), R) 18 (It is a covalent bond or a divalent organic group. A is an alkali metal element.) In formula (A6), the number of carbon atoms in the divalent organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 6, 1 to 5, or 1 to 3. R 18 When it contains carbon atoms, R 18 For R 18 The divalent groups other than those formed by replacing all carbon atoms with fluorine atoms. R 18 When it contains carbon atoms, R 18 At least one of the carbon atoms contained therein is bonded to a substituent other than a hydrogen atom or a fluorine atom.

[0064] Examples of alkali metal sulfonic acid groups represented by formula (A6) include -SO3A, -CH2-SO3A, and -C6H4-SO3A.

[0065] Polymer (A) is an alkali-metallized group other than functional group (A) (hereinafter also referred to as functional group (A')). Examples of such groups include alkali-metallized alcohol groups and alkali-metallized phosphate groups. Functional group (A') may be included in structural unit (A) or may be a structural unit different from structural unit (A) (i.e., a structural unit that does not have functional group (A) but has functional group (A'), and therefore does not belong to any of the structural units (B) described later, hereinafter also referred to as structural unit (A')). In addition, polymer (A) may contain structural units (hereinafter also referred to as structural units (B)) with functional groups that function as anion acceptors.

[0066] In addition to polymer (A), the electrolyte composition of this embodiment may also contain other polymers that do not contain functional group (A) but have the ability to preferentially conduct alkali metal ions. Examples of other polymers include polymers containing at least one of structural unit (A') and structural unit (B) (hereinafter referred to as polymer (B)). Polymer (B) does not have functional group (A).

[0067] Structural unit (B) functions as an anion acceptor. Anion acceptors are chemical species that capture anions by forming electrostatic interactions, hydrogen bonds, or acid-base complexes with them.

[0068] Structural unit (B) captures the counter anion of the alkali metal ion in the alkali metal salt, promoting the dissociation of the counter anion from the alkali metal ion. This further increases the mobility of the alkali metal ion. On the other hand, the counter anion is captured by the polymer via structural unit (B), thus reducing its mobility. As a result, the mobility of the alkali metal ion is considered to increase. Furthermore, due to the increased mobility of the alkali metal ion, its conductivity is also expected to improve. Low-molecular-weight chemical species (compounds, etc.) that function as anion acceptors are known; examples of such compounds include those described in U.S. Patent Nos. 6,022,643, 5,705,689, and 6,120,941.

[0069] Functional groups that function as anion acceptors can be functional groups with Lewis acidity. In this case, the aforementioned functional group can accept the non-covalent electron pairs of anions and capture the anions by forming acid-base complexes. Functional groups with electron-deficient atoms can be listed as such functional groups. It should be noted that an electron-deficient atom is an atom that, although covalently bonded to other atoms, does not have its outermost electrons forming an octet. Electron-deficient atoms can be listed as atoms belonging to Group 13 of the periodic table; more specifically, they can be at least one of aluminum and boron, or boron.

[0070] As a functional group that functions as an anion acceptor, it can be a group containing an azeotropic moiety. The group containing an azeotropic moiety is a group with an azeotropic ether compound as a substituent, where the -O- of the ether compound is replaced with -NR. E - (Here, R) E A compound obtained by substituting a hydrogen atom or an organic group. The azeotropic moiety can be either a chain azeotropic moiety or a cyclic azeotropic moiety, or it can have both. The group having the azeotropic moiety may, for example, have an electron-withdrawing group such as a hydrocarbon moiety.

[0071] Structural unit (B) may include at least one of the structural units shown in equation (B) below. It should be noted that, except for R in equation (B)... 11 ~R 13 Structures other than W are also referred to as ethylene units.

[0072] [Chemical Formula 8] (In formula (B), W is a functional group that functions as an anion acceptor, R) 11 ~R 13 Each is independently a hydrogen atom or a monovalent substituent, or R 11 and R 13 One of them and R 12 They form a ring together, with the other being a hydrogen atom or a monovalent substituent. Indicates the location where structural unit (B) is bonded to other structural units. R 11 ~R 13 (One or more of the atoms can be hydrogen atoms, or all of them can be hydrogen atoms.) In equation (B), in R 11 ~R 13 When the substituent is monovalent, the monovalent substituent can be a monovalent organic group. The number of carbon atoms in the organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3.

[0073] In equation (B), in R 11 ~R 13 In the case of a monovalent substituent, the monovalent substituent can be an electron-withdrawing group or the electron-withdrawing group itself. The electron-withdrawing group can bond to the aforementioned monovalent organic group, which can be an electron-withdrawing group. Examples of electron-withdrawing groups include halogen atoms, sulfonic acid groups or their salts, sulfonates, nitro groups, and nitrile groups. The halogen atom can be any one of fluorine, chlorine, bromine, and iodine atoms.

[0074] In equation (B), R 11 and R 13 One of them and R 12 When they form a ring together, R 11 Or R 12 With R 13 Divalent substituents are formed, each bonded to one of the two carbon atoms of the ethylene unit of formula (B). These rings can be either carbocyclic or heterocyclic. The number of ring members can be, for example, 4–10, 5–8, 5, or 6. Substituents can be bonded to the carbon atom or heteroatom that is a ring member.

[0075] In formula (B), W preferably has a group represented by the following formula (B1).

[0076] [Chemical Formula 9] (In formula (B1), W) B For atoms belonging to group 13 of the periodic table, R 15 R is a covalent bond or a divalent organic group. 16 and R 17 Each can be an independent hydrogen atom, -OH group, halogen atom, or monovalent organic group, or they can form a ring together. 16 and R 17 (These can be the same group or different groups.) W in equation (B1) B It can be at least one of aluminum atoms and boron atoms, or it can be a boron atom.

[0077] In equation (B1), R is 15 In the case of a divalent organic group, the number of carbon atoms in the divalent organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. In R 15 In the case of a divalent organic group, the organic group can be, for example, a hydrocarbon group, a halogen-substituted hydrocarbon group, or a hydrocarbon group or a halogen-substituted hydrocarbon group connected to W via an ether bond. BBonded groups. The aforementioned halogen-substituted hydrocarbon groups can be groups obtained by replacing some or all of the hydrogen atoms in a hydrocarbon group with halogen atoms; they can be partially fluorinated or perfluorinated hydrocarbon groups. R 15 It can be a covalent bond.

[0078] In equation (B1) R 16 Or R 17 In the case of halogen atoms, R 16 Or R 17 It can be any one of fluorine, chlorine, bromine, and iodine atoms, or it can be a fluorine atom. R 16 Or R 17 They can be the same or different.

[0079] In equation (B1) R 16 Or R 17 In the case of a monovalent organic group, the number of carbon atoms in the monovalent organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. R 16 Or R 17 For example, it can be a hydrocarbon group, a halogen-substituted hydrocarbon group, or a hydrocarbon group or a halogen-substituted hydrocarbon group connected to W via an ether bond. B Bonded groups. The above-mentioned halogen-substituted hydrocarbon groups can be groups obtained by replacing part or all of the hydrogen atoms in the hydrocarbon group with halogen atoms, and can be partially fluorinated or perfluorinated hydrocarbon groups.

[0080] The group represented by formula (B1) can be the group represented by formula (B1a) or the group represented by formula (B1b).

[0081] [Chemical Formula 10] (In formula (B1a), R) 15 W is a covalent bond or a divalent organic group. B X is an atom belonging to group 13 of the periodic table. 11 and X 12 Each is an oxygen atom or a covalent bond. In X 11 In the case of covalent bonds, R 22 It can be a hydrogen atom, a halogen atom, or a monovalent organic group. In X 11 In the case of oxygen atoms, R 22 It can be a hydrogen atom or a monovalent organic group. In X 12 In the case of covalent bonds, R 23 It can be a hydrogen atom, a halogen atom, or a monovalent organic group. In X 12 In the case of oxygen atoms, R 23 It can be a hydrogen atom, a halogen atom, or a monovalent organic group. In X 11 and X12 If the atoms are oxygen atoms, they can be oxygen atoms that form ether bonds. [Chemical Formula 11] (In formula (B1b), R) 15 W is a covalent bond or a divalent organic group. B X is an atom belonging to group 13 of the periodic table. 13 and X 14 They are oxygen atoms or covalent bonds, R 24 (It is a divalent organic group.) In equation (B1a), in R 22 Or R 23 In the case of a monovalent organic group, the monovalent organic group can be a monovalent hydrocarbon group or a monovalent halogen-substituted hydrocarbon group. The number of carbon atoms in the monovalent organic group can be, for example, 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 3. The aforementioned halogen-substituted hydrocarbon group can be a group obtained by replacing some or all of the hydrogen atoms in the hydrocarbon group with halogen atoms; it can be a partially fluorinated hydrocarbon group or a perfluorinated hydrocarbon group. In R... 22 Or R 23 In the case of halogen atoms, the halogen atom can be a fluorine atom.

[0082] R in equation (B1a) 22 and R 23 Each can independently be -F, -CH3, -C2H5, -C3H7, -C6H5 (phenyl), -C6H n F 5-n (n is an integer from 0 to 4, and can be an integer from 0 to 3), -CF3, -CH2CF3, -CH2CF3CF7, -CH(CF3)2, -C(CF3)2-C6H5, -C(CF3)3 and -C6H n (CF3) 5-n (n is an integer from 0 to 4, and can be 1 or 2).

[0083] R in equation (B1b) 24 This is a divalent organic group, and the number of carbon atoms in this divalent organic group can be, for example, 1 to 20, 1 to 15, 2 to 10, or 3 to 8. The aforementioned divalent organic group can be a hydrocarbon group or a halogen-substituted hydrocarbon group. The aforementioned halogen-substituted hydrocarbon group can be a group obtained by replacing some or all of the hydrogen atoms in the hydrocarbon group with halogen atoms, and can be a partially fluorinated or perfluorinated hydrocarbon group.

[0084] As R in equation (B1b) 24 For example, -C2H4-, -C3H6-, -C4H8-, and -C5H can be listed.10 -、-C6H 12 -、-C7H 14 -、-C8H 16 -、-C9H 18 -、-C 10 H 20 - and groups obtained by partially or completely replacing their hydrogen atoms with fluorine, etc. More specifically, R 24 It can be -C(CH3)2-C(CH3)2-.

[0085] The polymer (A) may have a structural unit (C) that is not any of structural unit (A), structural unit (A'), or structural unit (B). The structural unit (C) may comprise the structural unit shown in the following formula (C).

[0086] [Chemical Formula 12] (In formula (C), R) 25 R is a hydrogen atom or a monovalent substituent. 26 ~R 28 Each is independently a hydrogen atom or a monovalent substituent, or R 26 and R 27 One of them is a hydrogen atom or a monovalent substituent, and the other is related to R. 28 Together they form a ring. (This refers to the bonding portion of structural unit (C) with other structural units.) R in equation (C) 25 It can be a monovalent organic group. R 25 The number of carbon atoms can be, for example, 1 to 40, 1 to 20, 2 to 15, or 4 to 13. The monovalent organic group can be -Z. 1 -R 29 The group shown. Here, Z 1 It is a divalent linker, such as a covalent bond, -O-, -S-, -C(=O)-, -C(=O)O-, -OC(=O)-, -C(=O)NR. 38 -or-NR 39 The group represented by C(=O)-.

[0087] Z, as the aforementioned divalent linker group 1 In the case of covalent bonds, -O-, -S-, -C(=O)-, -C(=O)O-, or -OC(=O)-, R 29 It can be a hydrogen atom or a monovalent organic group.

[0088] Z, as the aforementioned divalent linker group 1 -C(=O)NR38 In the case of -R 29 R 38 These are either hydrogen atoms or monovalent organic groups, or R. 29 With R 38 Together they form a ring. In the aforementioned Z... 1 For -NR 39 In the case of C(=O)-, R 29 R 39 These are either hydrogen atoms or monovalent organic groups, or R. 29 With R 39 Together they form a loop. As R 29 R 38 and R 39 The number of carbon atoms in a monovalent organic group can be 1 to 20 or 1 to 10. R 38 In the case of a monovalent organic group, it can be a monovalent hydrocarbon group having 1 to 20 carbon atoms.

[0089] Z, as the aforementioned divalent linker group 1 In the case of covalent bond or -C(=O)O-, R 29 It can be a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. Z 1 It is a covalent bond and R 29 When the group is a hydrocarbon group, it can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Additionally, R... 29 It can be a monovalent organic group other than a hydrocarbon group or a hydrocarbon group with a ring structure.

[0090] Z, which serves as the aforementioned divalent linking group 1 In the case of -O-, W can be used. 0 As an alkyl ether, W 0 Monovalent organic groups other than those indicated by -H. Regarding monovalent organic groups, in R... 26 ~R 28 In the case of a monovalent organic group, examples of monovalent organic groups that are similar to R can be listed. 25 Examples of groups that are the same as those listed.

[0091] In groups having an aromatic ring (e.g., the aromatic hydrocarbon groups mentioned above), a monovalent substituent can be bonded to the aromatic ring. Examples of monovalent substituents include monovalent organic groups, substituted or unsubstituted hydrocarbon groups, and groups with the formula: -R 61 -(W) 1 -R 62 ) n -W 2 R 63 The groups shown are, etc.

[0092] Formula: -R61 -(W) 1 -R 62 ) n -W 2 R 63 The shown group can be bonded to the para position of the benzene ring. W 1 It can be a divalent group such as -O-, -S-, -C(=O)-, or -C(=O)O-, and can be -O-. W 2 It can be a divalent group such as -O-, -S-, -C(=O)- or -C(=O)O-, and can be -O-.

[0093] R in the above monovalent organic groups 61 It is a covalent bond or a divalent organic group. The divalent organic group can be a divalent hydrocarbon group. The number of carbon atoms in the divalent hydrocarbon group can be, for example, 1 to 8, 1 to 5, or 1 to 3. The hydrogen atom bonded to the above-mentioned divalent hydrocarbon group can be replaced by a substituent such as a monovalent substituent (i.e., it can be a substituted hydrocarbon group). Examples of substituents include halogen atoms such as fluorine atoms. Specifically, the above-mentioned divalent hydrocarbon group can be methylene, ethylene, 1,2-propylene, 1,3-propylene, or a group obtained by replacing some or all of their hydrogen atoms with halogen atoms such as fluorine atoms. Methylene is an example of such a group.

[0094] R in the above monovalent organic groups 62 It is a divalent organic group, which can be a divalent hydrocarbon group. The number of carbon atoms in the divalent hydrocarbon group can be, for example, 1 to 8, 1 to 5, or 1 to 3. The hydrogen atom bonded to the above-mentioned divalent hydrocarbon group can be replaced by a substituent such as a monovalent substituent (i.e., it can be a substituted hydrocarbon group). Examples of such substituents include halogen atoms such as fluorine atoms. Specifically, the divalent hydrocarbon group can be methylene, ethylene, 1,2-propylene, 1,3-propylene, or a group in which some or all of their hydrogen atoms are replaced by halogen atoms such as fluorine atoms, or it can be ethylene.

[0095] The above formula: -R 61 -(W) 1 -R 62 ) n -W 2 R 63 The 'n' in the represented group can be, for example, 1~10, 1~5, or 1~3. The 'n' mentioned above can be an integer or a rational number (e.g., the case where 'n' is the average value of the structural units (B) possessed by the polymer). Multiple 'R' groups exist within a single structural unit. 62 In certain circumstances, they can be different or the same.

[0096] R in the above monovalent organic groups 63The group can be a hydrogen atom or a monovalent hydrocarbon group. The monovalent hydrocarbon group can have, for example, 1 to 8, 1 to 5, or 1 to 3 carbon atoms. The hydrogen atom bonded to the monovalent hydrocarbon group can be replaced by a substituent such as a monovalent substituent (i.e., it can be a substituted hydrocarbon group). Examples of substituents include halogen atoms such as fluorine atoms. The monovalent hydrocarbon group can be methyl, ethyl, isopropyl, n-propyl, or a group obtained by replacing some or all of their hydrogen atoms with halogen atoms such as fluorine atoms, or it can be methyl.

[0097] In the case where the polymer (A) has a structural unit (C), the structural unit (C) may contain structural units from the monomer represented by the following formula (C1).

[0098] [Chemical Formula 13] (In formula (C1), m is 0~4 and n is 0~10. R) 31 It can be an alkyl group having 1 to 4 carbon atoms or hydrogen atoms. The alkyl group can be methyl or ethyl, or it can be methyl. In equation (C1), m can be, for example, 1 to 3, 1 to 2, or 1. m can be an integer, or it can be the average value of the total number of structural units from the monomers shown in equation (C1) contained in the polymer (in which case m is a rational number). In equation (C1), n ​​can be, for example, 1 to 4 or 1 to 3. n can be an integer, or it can be the average value of the total number of structural units from the monomers shown in equation (C1) contained in the polymer (in which case n is a rational number).

[0099] In the case where polymer (A) has structural unit (C), R in structural unit (C) 26 and R 27 One of them and R 28 When they form a ring, the ring members can be, for example, 4~10, 4~8, or 5~7. In structural unit (C), R... 27 With R 28 When they form a ring together, the structural unit (C) can be the following structural unit (C2).

[0100] [Chemical Formula 14] (In formula (C2), X is an oxygen atom or -NR) 31 -The tertiary amino group shown, R 31 R is a monovalent organic group. 25 and R 26 Each can be an independent hydrogen atom or a monovalent substituent. In equation (C2), X is -NR 31 In the case of the tertiary amine shown, R31 The number of carbon atoms it contains can be, for example, 1 to 20, 1 to 15, or 2 to 10. The above R... 31 It can be a hydrocarbon group or a fluorinated hydrocarbon group, and can be ethyl, 2,2,2-trifluoroethyl, n-dodecyl, cyclohexyl or benzyl.

[0101] The ratio of structural unit (A) to all structural units contained in polymer (A) can be 0.2 to 0.95, 0.2 to 0.8, 0.3 to 0.7, or 0.4 to 0.6.

[0102] The ratio of structural unit (C) to all structural units contained in polymer (A) can be, for example, 0.05 to 0.8, 0.2 to 0.8, 0.3 to 0.7, or 0.4 to 0.6. The ratio of structural unit (C) to all structural units contained in polymer (A) can be less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, or less than 0.3.

[0103] The ratio of structural unit (A) and structural unit (C) to the total number of structural units contained in polymer (A) can be, for example, 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.

[0104] The content of structural unit (A) relative to the total mass of polymer (A) can be, for example, 25-95% by mass, 40-90% by mass, or 50-90% by mass.

[0105] The content of structural unit (C) relative to the total mass of polymer (A) can be, for example, 5 to 75% by mass, 10 to 60% by mass, or 10 to 50% by mass. The content of structural unit (C) relative to the total mass of polymer (A) can be, for example, less than 75% by mass, less than 60% by mass, less than 50% by mass, or less than 25% by mass.

[0106] The combined content of structural unit (A) and structural unit (C) relative to the total mass of polymer (A) can be, for example, 90% or more by mass, 95% or more by mass, or 98% or more by mass.

[0107] When polymer (A) contains structural unit (B), the molar ratio m of structural unit (B) to all structural units contained in polymer (A) can be, for example, 0.2~0.8, 0.25~0.75, 0.3~0.7, 0.35~0.65 or 0.4~0.6.

[0108] The content of the structural unit (B) based on the total mass of the polymer (A) may be, for example, more than 10 mass% and 95 mass% or less, 15 to 95 mass%, 20 to 80 mass%, 25 to 60 mass%, or 30 to 45 mass%.

[0109] The number average molecular weight (Mn) of the polymer (A) may be, for example, 5000 to 400000, 8000 to 200000, 10000 to 150000, or 10000 to 100000. The weight average molecular weight (Mw) of the polymer (A) may be, for example, 5000 to 600000, 10000 to 450000, 20000 to 200000, or 20000 to 100000. The molecular weight distribution (Mw / Mn) of the polymer (A) may be, for example, 1.0 to 5.0, 1.2 to 3.0, or 1.3 to 2.5.

[0110] In the present specification, the number average molecular weight and weight average molecular weight of the polymer (A) can be measured by gel permeation chromatography (GPC) performed under the following conditions. It should be noted that, in the preparation of the standard curve, a standard sample of polymethyl methacrylate (manufactured by Polymer Laboratories, with Mn of 800 to 2200000) is used as the standard substance.

[0111] <GPC Measurement Conditions> Apparatus: High-performance liquid chromatography manufactured by JASCO Corporation PU-2080 precision pump RI-2031 refractive-index detector UV-2075 UV / vis detector Column: Shodex KF-805L (exclusion limit: 4×10 6 , particle size: 10μm, pore size: 5000Å, inner diameter: 0.8cm, length: 30cm) Temperature: 40°C Solvent: N,N-Dimethylformamide (DMF) Flow rate: 1.0mL / min Back pressure: 3.0MPa Detection: RI Sample concentration: 0.5 mass% DMF solution Injection volume: 10μL The content of polymer (A) in the electrolyte composition of this embodiment may be, for example, 1 to 80% by mass, 3 to 70% by mass, 5 to 60% by mass, or 10 to 40% by mass relative to the total amount of the electrolyte composition.

[0112] There are no particular limitations on the manufacturing methods of polymer (A) and polymer (B). For example, they can be manufactured by polymerization reactions such as free radical addition polymerization of the corresponding monomers.

[0113] <particles> The particles contained in the electrolyte composition of this embodiment are not particularly limited and can be either inorganic or organic particles. The particles can be non-conductive. Preferably, the particle material has a conductivity measured at 25°C that is below a certain value, for example, 1.0 × 10⁻⁶. -6 Sm -1 Below, 1.0×10 -7 Sm -1 Below or 1.0×10 -10 Sm -1 the following.

[0114] Examples of inorganic particles include oxide particles, nitride particles, carbide particles, carbon particles, sulfur particles, and silicate mineral particles. Examples of oxide particles include silicon dioxide particles, aluminum oxide particles, and titanium dioxide particles. Examples of nitride particles include boron nitride particles and aluminum nitride particles. Examples of carbide particles include silicon carbide particles. Examples of silicate mineral particles include mica. Examples of organic particles include acrylic acid particles and melamine particles.

[0115] The aforementioned particles can be nanoparticles. The average particle size can be, for example, below 500 nm, below 300 nm, below 200 nm, below 150 nm, below 100 nm, or below 80 nm, or above 1 nm, above 3 nm, or above 5 nm. Alternatively, the average particle size can be below 1–500 nm, 1–300 nm, 3–200 nm, 3–150 nm, 5–100 nm, 5–80 nm, or 5–50 nm.

[0116] The average particle size in this specification refers to the particle size (D50) at which the cumulative value from the smallest particle size reaches 50% in a volume-based particle size distribution measured using a laser diffraction particle size distribution meter. For example, the laser diffraction particle size distribution system described above can be represented by products such as Shimadzu's "SALD2200" (trade name) and "SALD2300" (trade name).

[0117] Regarding the primary particles mentioned above, their maximum particle size can be, for example, less than 500nm, less than 300nm, less than 200nm, less than 150nm, less than 100nm, or less than 80nm, or more than 1nm, more than 3nm, or more than 5nm.

[0118] The maximum value of the primary particle size (maximum particle size) of the aforementioned particles can be determined by analyzing images obtained using a scanning electron microscope or a transmission electron microscope. More specifically, from the images obtained by a scanning electron microscope or a transmission electron microscope, from the primary particles of the particles being measured, 100 particles that are visually judged to be large in the images are selected, the particle size of the selected particles is measured, and the maximum value of this selected particle size is taken as the aforementioned maximum particle size.

[0119] The particle content in the electrolyte composition, relative to the total amount of the electrolyte composition, can be, for example, less than 50% by mass, less than 40% by mass, less than 35% by mass, or less than 30% by mass, or more than 0.1% by mass, more than 1% by mass, more than 5% by mass, more than 10% by mass, or more than 15% by mass. The particle content in the electrolyte composition, relative to the total amount of the electrolyte composition, can be 0.1 to 50% by mass, 1 to 40% by mass, 5 to 35% by mass, 10 to 30% by mass, or 15 to 25% by mass.

[0120] <Organic solvents> As organic solvents, aprotic solvents can be listed. The organic solvent may contain one or more solvents selected from carbonate solvents, ether solvents, fluorinated solvents, nitrile solvents, phosphate solvents, and sulfone solvents, and may include carbonate solvents. In the electrolyte composition, polymer (A) can be swollen by the organic solvent.

[0121] Examples of carbonate solvents include chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; and cyclic carbonates such as ethylene carbonate, propylene carbonate, butyl carbonate, and vinylene carbonate. The organic solvent can be a mixture of two or more carbonate solvents, a mixture of one or more cyclic carbonate solvents and one or more chain carbonate solvents, or a mixture of two or more cyclic carbonate solvents.

[0122] Examples of ether solvents include cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, and 1,3-dioxane; and chain ethers such as 1,2-diethoxyethane and ethoxymethoxyethane.

[0123] Examples of fluorinated solvents include hydrofluorocarbons such as perfluorooctane; hydrofluoroethers such as methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether; hydrofluoroolefins such as 1,3,3,3-tetrafluoropropene; and 2,2,2-trifluoro-N,N-dimethylacetamide.

[0124] Examples of nitrile solvents include acetonitrile and succinic anhydride. Examples of lactone solvents include γ-butyrolactone.

[0125] Examples of phosphate ester solvents include trimethyl phosphate (TMP), triethyl phosphate (TEP), and tri(2,2,2-trifluoroethyl) phosphate (TFEP).

[0126] Examples of sulfonic acid solvents include sulfolane and 3-methylsulfolane.

[0127] In addition to the solvents mentioned above, organic solvents that can be listed as organic solvents include sulfonyl solvents such as dimethyl sulfoxide (DMSO); amide solvents such as dimethylformamide (DMF) and dimethylacetamide (DMA); organic solvents that contain carbonyl groups such as acetone (referring to carbonyl compounds other than amide compounds such as -C(=O)-, esters, ketones, and aldehydes); and nitrogen-containing aromatic compounds such as pyridine (compounds containing nitrogen as a ring member, which can be either monocyclic or fused-ring). Organic solvents can be used alone or as a mixture containing two or more organic solvents.

[0128] The content of organic solvent in the electrolyte composition may be, for example, 10-1000 parts by mass, 50-800 parts by mass, 100-600 parts by mass, 150-600 parts by mass, or 200-500 parts by mass relative to 100 parts by mass of polymer contained in the electrolyte composition.

[0129] The migration number of the alkali metal ions in the electrolyte composition can be, for example, 0.5 or more, 0.6 or more, or 0.7 or more. The migration number is set as the migration number measured at room temperature (25°C).

[0130] In addition to the components described above, the electrolyte composition involved in this embodiment may also include, for example, other resins such as fluorinated resins (resins other than polymers (A) and (B) mentioned above, such as adhesive resins), porous materials, alkali metal salts, film-forming additives, nonwoven fabrics, viscosity modifiers, and anion acceptors.

[0131] <Other Resins> Fluorinated resins can include resins with carbon chains as the main chain. These carbon chains can be formed by free radical polymerization of olefinically unsaturated groups. Examples of fluorinated resins include polytetrafluoroethylene (PTFE), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and polyvinylidene fluoride (PVDF).

[0132] The content of other resins in the electrolyte composition may be, for example, 0.1 to 20% by mass, 0.5 to 10% by mass, or 1 to 5% by mass relative to the total amount of the electrolyte composition. The content of other resins may be 10 to 200 parts by mass or 50 to 150 parts by mass relative to 100 parts by mass of polymer (A).

[0133] <Porous Materials> Porous materials can be resin-based porous materials. Specifically, examples of porous materials include porous polyolefin membranes and porous ceramic membranes.

[0134] Alkali metal salts As alkali metal salts, the alkali metal is designated as M, and examples include MF, MCl, MBr, MI, MNO3, MClO4, MPF6, MBF4, M2SO4, and M[(C h F 2h+1 SO3] (h is 0~3), M[(C h F 2h+1 SO2]2N (h is 0~3), M{[(C h F 2h+1 SO2]N[(C i F 2i+1 Alkali metal salts can be one type or in combination of multiple types, such as SO2 (h, i = 0~3) and MBOB (BOB = bis(oxalato)borate). There are no particular restrictions on the alkali metal M as long as it is an element classified as an alkali metal; for example, it can contain lithium, sodium, or potassium. The alkali metal element contained in the alkali metal salt can be the same alkali metal element as that present in structural unit (A) and structural unit (A').

[0135] The content of alkali metal salt in the electrolyte composition, relative to the total amount of structural units (A) of the polymer (A), is calculated in terms of the alkali metal ions contained in the alkali metal salt, for example, 0.1 to 200 mol%, 2.5 to 150 mol%, 5 to 100 mol%, or 10 to 60 mol%.

[0136] <Additives for film formation> Film-forming additives are compounds capable of forming a film (solid electrolyte interface, SEI) on the electrode surface through an electrolytic reaction. Therefore, film-forming additives can also be SEI forming agents. As film-forming additives, they can be at least one of electrolytically oxidatively polymerizable compounds and electrolytically reductively polymerizable compounds, or they can be electrolytically reductively polymerizable compounds. By using electrolytically reductively polymerizable compounds, a film can be formed on the negative electrode.

[0137] The content of the film-forming additive in the electrolyte composition relative to 100 parts by weight of polymer (A) can be, for example, 0.01 to 100 parts by weight, 0.1 to 80 parts by weight, 1 to 50 parts by weight, 1 to 30 parts by weight, 3 to 25 parts by weight, or 5 to 20 parts by weight.

[0138] There are no particular limitations on the method for manufacturing the electrolyte composition; it can be obtained by mixing a polymer, an organic solvent, and particles. Alkali metal salts and film-forming additives can be added at this time. The electrolyte composition can be molded into a film or granules for use as a molded body.

[0139] The electrolyte composition of this embodiment can be used, for example, as a composition for forming electrolytes in electrode compositions, batteries, and capacitors. That is, one embodiment of the electrode composition includes an electrolyte, which may contain the electrolyte composition. Similarly, one embodiment of the battery and capacitor includes an electrolyte, which may contain the electrolyte composition. Examples of batteries include lithium-ion batteries and sodium-ion batteries, which are charged and discharged by the movement of alkali metal ions. The battery can be a primary battery, a secondary battery, or a solid-state battery. The electrolyte composition of this embodiment can be used as an electrode composition or may be included in at least one of a positive electrode and a negative electrode. That is, the electrolyte composition is suitable as an electrode material. An electrode formed from the electrode composition can become an electrode with excellent ion conductivity.

[0140] (Battery) The battery of this embodiment includes a positive electrode, a negative electrode, and an electrolyte disposed between the positive and negative electrodes. The electrolyte can be formed by disposing the electrolyte composition of this embodiment between the positive and negative electrodes. Alternatively, the battery may also include an electrolyte other than the electrolyte formed by the electrolyte composition of this embodiment (such as a solid electrolyte layer). The positive electrode may be a positive electrode on which a layer containing a positive electrode material is formed. The negative electrode may be a negative electrode on which a layer containing a negative electrode material is formed. Furthermore, when the electrolyte composition includes an organic solvent, it is easier to form an interface between the electrodes (positive and negative electrodes) and the electrolyte. In other words, the electrolyte composition may include an organic solvent in order to form an interface between at least one of the positive electrode and the electrolyte, and between the negative electrode and the electrolyte. It should be noted that the organic solvent can be added to the electrolyte composition either during battery assembly or when the electrolyte composition is disposed between the electrodes. Hereinafter, a lithium-ion battery will be used as an example to describe the battery of this embodiment.

[0141] There are no particular limitations on the negative electrode of a lithium-ion battery. It can be a negative electrode containing a negative electrode active material and, as needed, conductive additives, binders, etc. Examples of negative electrode active materials include elemental forms of Li, Si, P, Sn, Si-Mn, Si-Co, Si-Ni, In, Au, and alloys or composites containing these elements; carbon materials such as graphite; materials in which lithium ions are intercalated between the layers of the carbon material; and oxides containing titanium.

[0142] The cathode material of a lithium-ion battery is not particularly limited and can be any cathode containing a cathode active material and, if necessary, conductive additives, binders, etc. The cathode active material is also not particularly limited; examples include lithium composite metal oxides containing lithium and transition metal elements. The transition metal element can be at least one selected from V, Cr, Mn, Fe, Co, Ni, Cu, and Al, and may include Ni. Examples of lithium composite metal oxides include LiCoO2, LiNiO2, LiMn2O4, and LiNiO2. 0.5 Mn 1.5 O4, 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 0.5O2, LiFePO4, Li2FeP2O7, LiMnPO4, LiFeBO3, Li3V2(PO4)3, Li2CuO2, Li2FeSiO4, and Li2MnSiO4, etc. When the positive electrode active material contains an alkali metal element other than Li, examples can be given of replacing Li with other alkali metals in the above examples.

[0143] The negative electrode (negative electrode material) and positive electrode (positive electrode material) in this embodiment may further include solid electrolyte material, adhesive resin (binder) and conductive additives, etc.

[0144] The battery of this embodiment may have a separator. The separator may be a porous material or a porous material made of resin. Specifically, examples of porous materials include porous polyolefin membranes and porous ceramic membranes.

[0145] Example The present disclosure will now be described in more detail using examples and comparative examples. It should be noted that the present disclosure is not limited to the following examples.

[0146] Synthesis of Monomer X The monomer X shown in the following formula was synthesized using the following method.

[0147] [Chemical Formula 15] First, chlorosulfonic acid (69 mL, 1.04 mol) was added to N-phenylmaleimide (30 g, 0.17 mol) at 0 °C, and the mixture was stirred at 45–50 °C for 1 hour. The resulting product was cooled to room temperature and injected onto ice. After stirring for a short time, the precipitated crystals were filtered off, and the crystals were purified by silica gel column chromatography. The eluent used was a solution of hexane and ethyl acetate mixed in a volume ratio of 2 / 1 to 1 / 1. The purification yielded 34 g (73% yield) of the intermediate shown in the following formula. The obtained intermediate was a pale yellow solid.

[0148] [Chemical Formula 16] Next, a solution was prepared by dissolving trifluoromethanesulfonamide (manufactured by Tokyo Chemical Industry Co., Ltd.) (4.22 g, 28.3 mmol) in dehydrated acetonitrile (160 mL, manufactured by Kanto Chemical Co., Ltd.) under a nitrogen atmosphere. Lithium carbonate (1.0 equivalent relative to trifluoromethanesulfonamide), lithium hydroxide (2.0 equivalent relative to trifluoromethanesulfonamide), and the intermediate synthesized as described above (6.9 g, 25.5 mmol) were added sequentially to this solution, and the reaction was carried out at 0°C for 4.5 hours. After the reaction solution was cooled to room temperature, it was filtered, and the solvent was removed from the filtrate by distillation under reduced pressure. The residue was decanted with diethyl ether and dried under reduced pressure, yielding 10.5 g of a light brown solid monomer.

[0149] Synthesis of Copolymers Monomer X (0.558 g), styrene (0.149 g), and azobisisobutyronitrile (11.7 mg) obtained as described above were dissolved in 6.7 mL of dehydrated acetonitrile. Tetrahydronaphthalene was added as an internal standard, and the reaction was carried out at 60 °C for 24 hours under a nitrogen atmosphere while confirming the monomer consumption rate. The polymerization solution was dialyzed in acetonitrile and dried under vacuum at 120 °C to obtain 0.640 g of copolymer (yield 87%). The monomer induction ratio was monomer X:styrene = 52:48. The monomer induction ratio was determined by the copolymer... 1 The number-average molecular weight of the copolymer, Mn, was calculated by H-NMR to be 9.4 × 10⁻⁶. 4 Weight-average molecular weight Mw = 4.2 × 10⁻⁶ 5 The molecular weight distribution Mw / Mn = 4.45. It should be noted that the number-average molecular weight and weight-average molecular weight were determined by gel permeation chromatography.

[0150] (Example 1) [Preparation of the Electrolyte Composition] A gel-like polymer composition 1 (gel polymer 1) is prepared by mixing 100 parts by weight of the above copolymer and 50 parts by weight of PVdF-HFP (poly(vinylidene fluoride-co-hexafluoropropylene)) with 450 parts by weight of organic solvent.

[0151] The components were weighed and mixed in a mortar using 80 parts by weight of the gel polymer 1 prepared as described above, 20 parts by weight of pyrolytic silica (average particle size: 7 nm), and 3 parts by weight of polytetrafluoroethylene (PTFE) to obtain an electrolyte composition. It should be noted that the organic solvent used was obtained by mixing a mixture of ethylene carbonate (EC) and propylene carbonate (PC) (volume ratio 1:1) with fluoroethylene carbonate (FEC) at a mass ratio of 95:5.

[0152] (Example 2) The electrolyte composition was obtained in the same manner as in Example 1, except that aluminum oxide A (average particle size: 13 nm) was used instead of pyrolytic silicon dioxide.

[0153] (Example 3) The electrolyte composition was obtained in the same manner as in Example 1, except that aluminum oxide B (average particle size: 10 nm) was used instead of pyrolytic silicon dioxide.

[0154] (Example 4) In a resin formed by mixing 100 parts by weight of the above copolymer and 50 parts by weight of PVdF-HFP, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 450 parts by weight of organic solvent were mixed in an amount of 25 mol% relative to 100 mol% of the structural unit (A) of the above copolymer to prepare a gel-like polymer composition 2 (gel polymer 2).

[0155] The components, namely 80 parts by weight of the gel polymer 2 prepared as described above, 20 parts by weight of pyrolytic silica (average particle size: 7 nm), and 3 parts by weight of polytetrafluoroethylene (PTFE), were measured and mixed in a mortar to obtain an electrolyte composition. It should be noted that the organic solvent used was obtained by mixing a mixture of ethylene carbonate (EC) and propylene carbonate (PC) (volume ratio 1:1) with fluoroethylene carbonate (FEC) at a mass ratio of 95:5.

[0156] (Example 5) In a resin formed by mixing 100 parts by weight of the above copolymer and 50 parts by weight of PVdF-HFP, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 600 parts by weight of organic solvent were mixed in an amount of 25 mol% relative to 100 mol% of the structural unit (A) of the above copolymer to prepare a gel-like polymer composition 3 (gel polymer 3).

[0157] The components were weighed and mixed in a mortar using 80 parts by weight of the gel polymer 3 prepared as described above, 20 parts by weight of pyrolytic silica (average particle size: 7 nm), and 3 parts by weight of polytetrafluoroethylene (PTFE) to obtain an electrolyte composition. It should be noted that the organic solvent used was obtained by mixing a mixture of ethylene carbonate (EC) and propylene carbonate (PC) (volume ratio 1:1) with fluoroethylene carbonate (FEC) at a mass ratio of 95:5.

[0158] (Example 6) In a resin formed by mixing 100 parts by weight of the above copolymer and 50 parts by weight of PVdF-HFP, 450 parts by weight of bis(trifluoromethanesulfonylimide)lithium (LiTFSI) and 450 parts by weight of organic solvent were mixed in an amount of 50 mol% relative to 100 mol% of the structural unit (A) of the above copolymer to prepare a gel-like polymer composition 4 (gel polymer 4).

[0159] The components were measured and mixed in a mortar with 80 parts by weight of gel polymer 4, 20 parts by weight of pyrolytic silica (average particle size: 7 nm), and 3 parts by weight of polytetrafluoroethylene (PTFE) to obtain an electrolyte composition. It should be noted that the organic solvent used was obtained by mixing a mixture of ethylene carbonate (EC) and propylene carbonate (PC) (volume ratio 1:1) with fluoroethylene carbonate (FEC) at a mass ratio of 95:5.

[0160] (Example 7) Mix 100 parts by weight of the above copolymer with 300 parts by weight of organic solvent to prepare a gel-like polymer composition 5 (gel polymer 5).

[0161] The components were measured and mixed in a mortar using 80 parts by weight of the gel polymer 5 prepared as described above, 20 parts by weight of pyrolytic silica (average particle size: 7 nm), and 3 parts by weight of polytetrafluoroethylene (PTFE) to obtain an electrolyte composition. It should be noted that the organic solvent used was obtained by mixing a mixture of ethylene carbonate (EC) and propylene carbonate (PC) (volume ratio 1:1) with fluoroethylene carbonate (FEC) at a mass ratio of 95:5.

[0162] (Comparative Example 1) The gel polymer 1 prepared in Example 1 was used directly as the electrolyte composition of Comparative Example 1.

[0163] (Comparative Example 2) The gel polymer 4 prepared in Example 6 was used directly as the electrolyte composition of Comparative Example 2.

[0164] (Comparative Example 3) The gel polymer 5 manufactured in Example 5 was used directly as the electrolyte composition of Comparative Example 3.

[0165] <Determination of Maximum Direct Current Density> Evaluation cells for the coin-shaped CR2032 battery were assembled inside a glove box under a dry argon atmosphere. Specifically, the test stack was first fabricated by stacking the layers in the order of lithium / electrolyte composition / lithium within evaluation cell A.

[0166] The aforementioned evaluation battery was subjected to alternating cycles of 0.2 mA / cm² in both the positive and negative directions, with one cycle applied each time. 2 0.4mA / cm 2 0.8mA / cm 2 1.2mA / cm 2 1.6mA / cm 2 2.0mA / cm 2 2.4mA / cm 2 2.8mA / cm 2 3.2mA / cm 2 3.6mA / cm 2 4.0 mA / cm 2 and 4.4 mA / cm 2 A constant current test was conducted on the current density, and the test ended when the voltage reached 2V. The maximum current density that could flow before reaching 2V was defined as the maximum DC current density. The results are shown in Table 1.

[0167] <Determination of Ionic Conductivity> Evaluation cells for the coin-shaped CR2032 battery were assembled inside a glove box under a dry argon atmosphere. Specifically, the test stack was first fabricated by stacking layers in the order of stainless steel plate / electrolyte composition / stainless steel plate inside evaluation cell B.

[0168] The impedance was measured using an impedance measuring device at 25°C, with a frequency range of 0.1 Hz to 1 MHz and an applied voltage of 10 mV (vs. open circuit voltage). The ionic conductivity σ was calculated using the following formula: where R represents the impedance value, A represents the sample area, and t represents the sample thickness. The results are shown in Table 1.

[0169] σ(S·cm) -1 )=t(cm) / (R(Ω)×A(cm) 2 )) <Determination of activation energy> The ionic conductivity of the aforementioned evaluation battery B was also measured at 30℃, 40℃, 50℃, 60℃, and 70℃, and the change in ionic conductivity relative to temperature was measured. The activation energy was calculated using the Ariane formula (logk = logA - Ea / RT, k: reaction rate constant, A: frequency factor, Ea: activation energy, R: gas constant, T: absolute temperature) based on the slope of the graph of the common logarithm of ionic conductivity versus the reciprocal of temperature. The results are shown in Table 1.

[0170] Measurement of DC Current Density The DC current density was measured using the evaluation battery A (a test laminate made by stacking layers in the order of lithium / electrolyte composition / lithium) of the coin-shaped battery CR2032 described above, in the same manner as described in "Determination of Maximum DC Current Density".

[0171] <Determination of Lithium-ion Transference Number> The lithium-ion transference number was determined using evaluation cell A (a test laminate made by stacking layers in the order of lithium / electrolyte composition / lithium) of the above-mentioned coin-shaped battery CR2032.

[0172] The lithium-ion transport number was determined under the following conditions. At room temperature (25°C), a 10mV was applied to the test laminate, and the initial current (I0) and steady-state current (I0) were measured. ss Then, the obtained value is imported into the following formula to calculate the lithium-ion transference number (t). Li+ The results are shown in Table 1.

[0173] t Li+ =I ss / I0 (Lithium dissolution test) The following lithium dissolution test was conducted on the evaluation battery A (a test laminate made by stacking layers in the order of lithium / electrolyte composition / lithium) of the coin-shaped battery CR2032 prepared using the electrolyte compositions of Example 6 and Comparative Example 2, respectively.

[0174] That is, for the above-mentioned evaluated battery, at +400μA / cm 2 and -400μA / cm 2 A current density was alternately applied for 1 hour at different times, constituting one cycle. This cycle was repeated for evaluation battery A. In each cycle, the voltage value just before the current reversed from the positive to the negative direction was measured as the voltage value of that cycle. The relationship between the number of cycles and the voltage value of each cycle is shown in the figure. Figure 1 middle. Figure 1 In this study, the measurement results when the electrolyte composition of Example 6 was used were labeled as "combined with pyrolytic silica", and the measurement results when the electrolyte composition of Comparative Example 2 was used were labeled as "without pyrolytic silica".

[0175] The results shown in Table 1 confirm that by satisfying the requirements of the electrolyte composition involved in this disclosure, a larger current can be carried out at a lower voltage compared to an electrolyte composition that does not satisfy the requirements. For example, taking the same gel polymer as an example, it was confirmed that the electrolyte composition containing particles exhibits superior performance compared to the electrolyte composition without particles.

Claims

1. An electrolyte composition comprising a polymer, an organic solvent, and particles, The polymer has side groups, which contain one or more groups selected from alkali metallized phenolic groups, alkali metallized carboxylic acid groups, alkali metallized sulfonic acid groups, and alkali metallized sulfonylimide groups.

2. The electrolyte composition according to claim 1, wherein, The particles are nanoparticles.

3. The electrolyte composition according to claim 1 or 2, wherein, The side groups contain lithium ions or sodium ions.

4. The electrolyte composition according to claim 1 or 2, wherein, The organic solvent comprises one or more solvents selected from carbonate solvents, ether solvents, fluorinated solvents, nitrile solvents, lactone solvents, phosphate solvents, and sulfone solvents.

5. The electrolyte composition according to claim 1 or 2, wherein, The side group comprises one or more groups selected from lithium phenol, lithium carboxylic acid, lithium sulfonic acid, and lithium sulfonyl imide.

6. The electrolyte composition according to claim 1 or 2, wherein, It also contains alkali metal salts.

7. The electrolyte composition according to claim 1 or 2, wherein, The migration count is 0.5 or higher.

8. The electrolyte composition according to claim 1 or 2, wherein, The particles include one or more selected from carbon particles, sulfur particles, silicon oxide particles, aluminum oxide particles, titanium oxide particles, and organic particles.

9. The electrolyte composition according to claim 1 or 2, wherein, The content of the particles is less than 50% by mass relative to the total amount of the electrolyte composition.

10. An electrode composition comprising the electrolyte composition of claim 1 or 2.

11. A battery comprising the electrolyte composition of claim 1 or 2.

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