Mixture for electrochemical device, mix sheet for electrochemical device, electrochemical device, and method for manufacturing mix sheet for electrochemical device

Abstract

To provide a mixture for an electrochemical device which can improve sheet strength, a mixture sheet for an electrochemical device, an electrochemical device, and a method for manufacturing a mixture sheet for an electrochemical device.SOLUTION: A mixture for an electrochemical device contains fluoropolyether, a fibrillable resin, and an electrochemical device material.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a mixture for an electrochemical device, a mixture sheet for an electrochemical device, an electrochemical device, and a method for producing a mixture sheet for an electrochemical device. [Background technology]

[0002] BACKGROUND ART With the recent trend toward lighter and smaller electrical appliances, the development of electrochemical devices such as lithium ion secondary batteries with high energy density has been progressing.

[0003] As technologies relating to electrochemical devices, Patent Document 1 discloses an electrode for a secondary battery using a powdered active material, a conductive material, and a fluorine-containing polymer resin, and Patent Document 2 discloses a self-supporting solid composite electrolyte membrane using solid ion-conductive inorganic particles and a tetrafluoroethylene (co)polymer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-026984 [Patent Document 2] Special Publication No. 2022-546129 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a mixture for an electrochemical device, a mixture sheet for an electrochemical device, an electrochemical device, and a method for producing a mixture sheet for an electrochemical device, which are capable of improving sheet strength. [Means for solving the problem]

[0006] The present disclosure (1) is a mixture for an electrochemical device, which contains a fluoropolyether, a fibrillar resin, and an electrochemical device material.

[0007] The present disclosure (2) is the mixture for electrochemical devices according to the present disclosure (1), wherein the fluoropolyether is at least one of the fluoropolyethers represented by the following formulae (1) to (4): (1)R 1 -O-Ra 1 -Rb 1 -O-Ra 1 -R 1 (2)R 2 -Rb 2 -O-Ra 2 -Rb 2 -R 2 (3)R 3 -Rb 3 -O-Ra 3 -R 3 (4)R 4 -Rb 4 -R 4 (In the formula, Ra 1 ~Ra 3 are each independently a polyoxyalkylene group containing 4 to 50 oxyalkylene units and not containing fluorine, Ra 1 ~Ra 3 each oxyalkylene unit is independently —CHCHO— or —CHCH(J)O—; Each J is independently an alkyl group or an aryl group; Rb 1 ~Rb 4 are each independently a fluoropolyether group represented by the following formula (5): R 1 ~R 3 are each independently a hydrogen atom, a hydroxyl group, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, an aryl group, a carboxylic acid group, or a fluoroalkyl group having 1 to 3 carbon atoms, R 4 are each independently a fluorine atom, a hydrogen atom, a hydroxyl group, an aldehyde group, a carboxylic acid group, an alkyl ester group having 1 to 10 carbon atoms, an amide group which may have a substituent, or an amino group which may have a substituent. (5)-Rf 1 -Rf-O-Rf2 - (In the formula, Rf 1 and Rf 2 each independently represents an alkylene group having 1 to 16 carbon atoms which may be substituted with a fluorine atom, Rf is a divalent fluoropolyether group.

[0008] The present disclosure (3) is 1 ~Ra 3 are each independently a polyoxyalkylene group represented by the following formula (Ra-I): (Ra-I): -(CH2CH2O)r(CH2CH(CH3)O)s(CH2CH(CH2CH3)O)t(CH2CH(Ph)O)u- (In the formula, r, s, t, and u are each independently an integer of 0 or 1 or more, and r+s+t+u is 4 to 50.)

[0009] This disclosure (4) is 1 ~Ra 3 The mixture for electrochemical devices according to the present disclosure (2) or (3), wherein the number average molecular weight of the compound is 40 to 4,000.

[0010] The present disclosure (5) is the mixture for electrochemical devices according to any one of the present disclosures (2) to (4), wherein each Rf is independently a fluoropolyether group represented by the following formula (Rf-I): Formula (Rf-I): -(OC6F 12 )a-(OC5F 10 )b-(OC4F8)c-(OC3Rc6)d-(OC2F4)e-(OCF2)f- (In the formula, each Rc independently represents a hydrogen atom, a fluorine atom, or a chlorine atom, a, b, c, d, e, and f each independently represent an integer of 0 to 200; the sum of a, b, c, d, e, and f is greater than or equal to 1; The order of the repeating units designated by a, b, c, d, e, or f is arbitrary; When all Rc's are hydrogen atoms or chlorine atoms, at least one of a, b, c, e, and f is 1 or greater.

[0011] The present disclosure (6) is the mixture for electrochemical devices according to any one of the present disclosures (2) to (5), in which the Rfs are each independently a group represented by the following formula (Rf-II) or the following formula (Rf-I-II): Formula (Rf-II): -(OC3F6)d-(OC2F4)e- (In the formula, d is an integer of 1 to 200, and e is 0 or 1.) Formula (Rf-I-II): -(OC4F8)c-(OC3F6)d-(OC2F4)e-(OCF2)f- (In the formula, c and d each independently represent an integer of 0 to 30, e and f each independently represent an integer of 1 to 200; the sum of c, d, e, and f is 2 or more; The repeating units marked with c, d, e, or f may be arranged in any order.

[0012] The present disclosure (7) relates to the R 1 ~R 3 are each independently a methyl group, an ethyl group, a trifluoromethyl group, or a pentafluoroethyl group.

[0013] The present disclosure (8) is the mixture for electrochemical devices according to any one of the present disclosures (1) to (7), wherein the fibrillar resin is polytetrafluoroethylene.

[0014] The present disclosure (9) is the mixture for an electrochemical device according to any one of the present disclosures (1) to (8), wherein the electrochemical device material is an electrode active material.

[0015] The present disclosure (10) is the mixture for electrochemical devices according to any one of the present disclosures (1) to (9), wherein the fluoropolyether is liquid at any temperature between 25°C and 80°C.

[0016] The present disclosure (11) is the mixture for electrochemical devices according to any one of the present disclosures (1) to (10), in which the content of the polyalkylene oxide represented by the following formula (6) is less than 20 mass %: (6)R 1B -(OCHR 1A (CH2)jCHR 2A )n-OR 2B (In the formula, R 1A and R 2A are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, j is 0 or an integer of 1 to 2, R 1B and R 2B are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, n is an integer from 5 to 1000.

[0017] The present disclosure (12) is a mixture for electrochemical devices according to any one of the present disclosures (1) to (11), which contains a conductive assistant.

[0018] The present disclosure (13) is a mixture sheet for an electrochemical device, including the mixture for an electrochemical device according to any one of the present disclosures (1) to (12).

[0019] The present disclosure (14) is an electrochemical device using the mixture sheet for an electrochemical device according to the present disclosure (13).

[0020] The present disclosure (15) provides a method for producing a fluoropolymer-based electrochemical device, comprising the steps of: (1) mixing a fluoropolyether, a fibrillar resin, and an electrochemical device material; and (2) rolling the mixture for electrochemical devices obtained in the step (1) into a sheet.

[0021] The present disclosure (16) is the manufacturing method according to the present disclosure (15), wherein the fibrillar resin is polytetrafluoroethylene. [Effects of the Invention]

[0022] According to the present disclosure, it is possible to provide a mixture for an electrochemical device, a mixture sheet for an electrochemical device, an electrochemical device, and a method for manufacturing a mixture sheet for an electrochemical device, which are capable of improving sheet strength. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present disclosure will be specifically described below.

[0024] <Compounds for electrochemical devices> The present disclosure relates to a mixture for an electrochemical device, which contains a fluoropolyether, a fibrillar resin, and an electrochemical device material.

[0025] The mixture for electrochemical devices according to the present disclosure has the above-described configuration, and therefore can improve the strength of electrode sheets and solid electrolyte sheets. This is thought to be because the kneading of the fluoropolyether and the fibrillar resin improves the cohesion between the powders and promotes the generation of fibrils. Furthermore, the promotion of fibril formation makes it possible to reduce the amount of binder used and improve the energy density of electrochemical devices.

[0026] As the fluoropolyether, at least one of the following formulae (1) to (4) can be suitably used. These compounds can enhance the effect of improving sheet strength, and further improve the initial discharge capacity and the amount of gas generated. This is because Rb 1 ~Rb 4 This is thought to be because the compound of formula (1) to (3) exhibits good lubricity and improves packing density. 1 ~Ra 3 The portion can also provide ionic conductivity. (1)R 1 -O-Ra 1 -Rb 1 -O-Ra 1 -R 1 (2)R 2 -Rb2 -O-Ra 2 -Rb 2 -R 2 (3)R 3 -Rb 3 -O-Ra 3 -R 3 (4)R 4 -Rb 4 -R 4 (In the formula, Ra 1 ~Ra 3 are each independently a polyoxyalkylene group containing 4 to 50 oxyalkylene units and not containing fluorine, Ra 1 ~Ra 3 each oxyalkylene unit is independently —CHCHO— or —CHCH(J)O—; Each J is independently an alkyl group or an aryl group; Rb 1 ~Rb 4 are each independently a fluoropolyether group represented by the following formula (5): R 1 ~R 3 are each independently a hydrogen atom, a hydroxyl group, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, an aryl group, a carboxylic acid group, or a fluoroalkyl group having 1 to 3 carbon atoms, R 4 are each independently a fluorine atom, a hydrogen atom, a hydroxyl group, an aldehyde group, a carboxylic acid group, an alkyl ester group having 1 to 10 carbon atoms, an amide group which may have a substituent, or an amino group which may have a substituent. (5)-Rf 1 -Rf-O-Rf 2 - (In the formula, Rf 1 and Rf 2 each independently represents an alkylene group having 1 to 16 carbon atoms which may be substituted with a fluorine atom, Rf is a divalent fluoropolyether group.

[0027] Ra 1 ~Ra3 When the oxyalkylene unit is -CHCH(J)O-, the alkyl group of J may be linear or branched, but is preferably linear. The alkyl group of J preferably has 1 to 3 carbon atoms. Examples of the aryl group for J include a phenyl group, a 4-nitrophenyl group, a 4-acetylaminophenyl group, and a 4-methanesulfonylphenyl group.

[0028] Ra 1 ~Ra 3 are preferably each independently a polyoxyalkylene group represented by the following formula (Ra-I): (Ra-I): -(CH2CH2O)r-(CH2CH(CH3)O)s-(CH2CH(CH2CH3)O)t-(CH2CH(Ph)O)u- (In the formula, r, s, t, and u are each independently an integer of 0 or 1 or more, and r+s+t+u is 4 to 50.)

[0029] In the above formula (Ra-I), r is preferably 1 or more, more preferably 2 or more, and is preferably 30 or less, more preferably 20 or less. s, t, and u are preferably 10 or less, more preferably 5 or less, and even more preferably 0. r+s+t+u is preferably 1 or more, more preferably 2 or more, and is preferably 20 or less, more preferably 10 or less.

[0030] Ra 1 ~Ra 3 The number average molecular weight of is preferably 40 or more, more preferably 100 or more, and is preferably 4000 or less, more preferably 1000 or less. In this specification, Ra 1 ~Ra 3 The number average molecular weight of 1 This is a value measured by H-NMR.

[0031] Rb 1 ~Rb 4In the above formula (5), Rf 1 and Rf 2 The alkylene group may be linear or branched, but is preferably linear. Rf 1 and Rf 2 The alkylene group is preferably a fluorine-substituted alkylene group substituted with a fluorine atom. Rf 1 and Rf 2 The alkylene group preferably has 1 to 3 carbon atoms.

[0032] Rb 1 ~Rb 4 In the above formula (5), Rf may have a ring structure.

[0033] Rb 1 ~Rb 4 In the formula (5), Rf is preferably a fluoropolyether group represented by the following formula (Rf-I): Formula (Rf-I): -(OC6F 12 )a-(OC5F 10 )b-(OC4F8)c-(OC3Rc6)d-(OC2F4)e-(OCF2)f- (In the formula, each Rc independently represents a hydrogen atom, a fluorine atom, or a chlorine atom, a, b, c, d, e, and f each independently represent an integer of 0 to 200; the sum of a, b, c, d, e, and f is greater than or equal to 1; The order of the repeating units designated by a, b, c, d, e, or f is arbitrary; When all Rc's are hydrogen atoms or chlorine atoms, at least one of a, b, c, e, and f is 1 or greater.

[0034] Rc is preferably a hydrogen atom or a fluorine atom, and more preferably a fluorine atom, That is, Rf in formula (5) is preferably a perfluoropolyether group.

[0035] It is preferred that a, b, c, d, e and f each independently represent an integer of 0 to 100.

[0036] The sum of a, b, c, d, e, and f is preferably 5 or more, more preferably 10 or more, and may be 15 or more or 20 or more. The sum of a, b, c, d, e, and f is preferably 100 or less, more preferably 60 or less, and may be 50 or less or 30 or less.

[0037] Each repeating unit denoted by a, b, c, d, e, or f may be linear or branched. -(OC6F 12 )- may be, for example, any of -(OCF2CF2CF2CF2CF2CF2CF2)-, -(OCF(CF3)CF2CF2CF2CF2)-, -(OCF2CF(CF3)CF2CF2CF2)-, -(OCF2CF2CF(CF3)CF2CF2)-, -(OCF2CF2CF2CF(CF3)CF2)-, or -(OCF2CF2CF2CF2CF(CF3))-. -(OC5F 10 )- may be, for example, any of -(OCF2CF2CF2CF2CF2)-, -(OCF(CF3)CF2CF2CF2)-, -(OCF2CF(CF3)CF2CF2)-, -(OCF2CF2CF(CF3)CF2)-, and -(OCF2CF2CF2CF(CF3))-. -(OC4F8)- may be, for example, any of -(OCF2CF2CF2CF2)-, -(OCF(CF3)CF2CF2)-, -(OCF2CF(CF3)CF2)-, -(OCF2CF2CF(CF3))-, -(OC(CF3)2CF2)-, -(OCF2C(CF3)2)-, -(OCF(CF3)CF(CF3))-, -(OCF(C2F5)CF2)-, and -(OCF2CF(C2F5))-. -(OC3F6)- (i.e., in the above formula (Rf-I), when all Rc's are fluorine atoms) may be, for example, any of -(OCF2CF2CF2)-, -(OCF(CF3)CF2)-, and -(OCF2CF(CF3))-. -(OC2F4)- may be, for example, either -(OCF2CF2)- or -(OCF(CF3))-.

[0038] Rf may be a group represented by any one of the following formulae (Rf-II) to (Rf-IV). Formula (Rf-II): -(OC3F6)d-(OC2F4)e- (In the formula, d is an integer of 1 to 200, and e is 0 or 1.) Formula (Rf-I-II): -(OC4F8)c-(OC3F6)d-(OC2F4)e-(OCF2)f- (In the formula, c and d each independently represent an integer of 0 to 30, e and f each independently represent an integer of 1 to 200; the sum of c, d, e, and f is 2 or more; The repeating units marked with c, d, e, or f may be arranged in any order. Formula (Rf-I-III): -(R 20 -R 21 )g- (In the formula, R 20 is OCF2 or OC2F4, R 21 are OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 or a combination of two or three groups selected from these groups, g is an integer from 2 to 100. Formula (Rf-I-IV): -(OC6F 12 )a-(OC5F 10 )b-(OC4F8)c-(OC3F6)d-(OC2F4)e-(OCF2)f- (In the formula, e is an integer of 1 to 200, a, b, c, d, and f each independently represent an integer of 0 to 200; The order of the repeating units marked with a, b, c, d, e, or f is arbitrary. Formula (Rf-IV): -(OC6F 12 )a-(OC5F 10 )b-(OC4F8)c-(OC3F6)d-(OC2F4)e-(OCF2)f- (wherein f is an integer of 1 to 200, a, b, c, d, and e each independently represent an integer of 0 to 200; The order of the repeating units marked with a, b, c, d, e, or f is arbitrary.

[0039] In the above formula (Rf-II), d is preferably 5 to 200, more preferably 10 to 100, and even more preferably 15 to 50, and may be 25 to 35. The above formula (Rf-II) is preferably a group represented by -(OCF2CF2CF2)d- or -(OCF(CF3)CF2)d-.

[0040] In the above formula (Rf-I-II), e and f are each independently an integer of preferably 5 to 200, more preferably 10 to 200. The sum of c, d, e and f is preferably 5 or more, more preferably 10 or more, and may be 15 or more or 20 or more. The above formula (Rf-I-II) is preferably a group represented by -(OCF2CF2CF2CF2)c-(OCF2CF2CF2)d-(OCF2CF2)e-(OCF2)f- or a group represented by -(OC2F4)e-(OCF2)f-, and more preferably a group represented by -(OC2F4)e-(OCF2)f-.

[0041] In the above formula (Rf-I-III), R 20 is preferably OC2F4, and R 21is preferably a group selected from OC2F4, OC3F6 and OC4F8, or a combination of two or three groups independently selected from these groups, more preferably a group selected from OC3F6 and OC4F8. The combination of two or three groups independently selected from OC2F4, OC3F6 and OC4F8 is not particularly limited, and examples thereof include -OC2F4OC3F6-, -OC2F4OC4F8-, -OC3F6OC2F4-, -OC3F6OC3F6-, -OC3F6OC4F8-, -OC4F8OC4F8-, -OC4F8OC3F6-, -OC4F8OC2F4-, -OC Examples include 2F4OC2F4OC3F6-, -OC2F4OC2F4OC4F8-, -OC2F4OC3F6OC2F4-, -OC2F4OC3F6OC3F6-, -OC2F4OC4F8OC2F4-, -OC3F6OC2F4OC2F4-, -OC3F6OC2F4OC3F6-, -OC3F6OC3F6OC2F4-, and -OC4F8OC2F4OC2F4-. In the above formula (Rf-I-III), g is preferably an integer of 3 or more, more preferably an integer of 5 or more. The above g is preferably an integer of 50 or less. In the above formula (Rf-I-III), OC2F4, OC3F6, OC4F8, OC5F 10 , and OC6F 12 may be either a straight chain or a branched chain, and is preferably a straight chain. In this embodiment, the above formula (Rf-I-III) is preferably -(OC2F4-OC3F6)g- or -(OC2F4-OC4F8)g-.

[0042] In the above formula (Rf-I-IV), e is preferably an integer of 1 to 100, more preferably an integer of 5 to 100. The sum of a, b, c, d, e, and f is preferably 5 or more, more preferably 10 or more, for example, 10 to 100.

[0043] In the above formula (Rf-IV), f is preferably an integer of 1 to 100, more preferably an integer of 5 to 100. The sum of a, b, c, d, e and f is preferably 5 or more, more preferably 10 or more, for example, 10 to 100.

[0044] In Rf, the ratio of e to f (hereinafter referred to as "e / f ratio") may be 0.5 to 4, preferably 0.6 to 3, more preferably 0.7 to 2, and even more preferably 0.8 to 1.4. By setting the e / f ratio to 4 or less, lubricity and chemical stability are further improved. The smaller the e / f ratio, the more improved the lubricity. On the other hand, by setting the e / f ratio to 0.5 or more, the stability of the compound can be further improved. The larger the e / f ratio, the more improved the stability of the fluoropolyether structure. In this case, the e / f ratio is preferably 0.8 or more.

[0045] Rf is represented by the following formula (Rf-I-VI): -(OCF2CF2CF2)a-(OCF(CF3)CF2)b-(OCF2CF(CF3))c-(OCF2CF2)d-(OCF(CF3))e-(OCF2)f- (In the formula, a, b, c, d, e, and f each independently represent an integer of 0 to 200, the sum of a, b, c, d, e, and f is greater than or equal to 1; The order of the repeating units marked with a, b, c, d, e, or f is arbitrary. It may be a group represented by the following formula:

[0046] Rf is represented by the following formula (Rf-I-VII): -(OCF2CF2)d-(OCF(CF3))e-(OCF2)f- (In the formula, d, e, and f each independently represent an integer of 0 to 200, the sum of d, e, and f is 1 or greater; The repeating units marked with d, e, or f may be arranged in any order. When Rf is this group, it is thought that the salt solubility will be improved because the number of ether bonds increases, which makes it easier for cations of the salt to coordinate.

[0047] In Rf, the ratio of d to f (hereinafter referred to as "d / f ratio") may be 0.5 to 4, preferably 0.6 to 3, more preferably 0.7 to 2, and even more preferably 0.8 to 1.4. By making the d / f ratio 4 or less, the lubricity and chemical stability are further improved. The smaller the d / f ratio, the more the lubricity is improved. On the other hand, by making the d / f ratio 0.5 or more, the stability of the compound can be further improved. The larger the d / f ratio, the more the stability of the fluoropolyether structure is improved. In this case, the value of the d / f ratio is preferably 0.8 or more.

[0048] Each Rf is preferably independently a group represented by the above formula (Rf-II) or (Rf-I-II), and more preferably a group represented by the above formula (Rf-I-II).

[0049] The number average molecular weight of Rf is not particularly limited, but is, for example, 500 to 30,000, preferably 1,500 to 30,000, and more preferably 2,000 to 10,000. In this specification, the number average molecular weight of Rf is 19 This is a value measured by F-NMR.

[0050] R 1 ~R 3 The alkyl group and fluoroalkyl group may be linear or branched, but are preferably linear. R 1 ~R 3 Examples of the aryl group include a phenyl group, a 4-nitrophenyl group, a 4-acetylaminophenyl group, and a 4-methanesulfonylphenyl group.

[0051] R 1 ~R 3are each independently preferably an alkyl group having 1 to 3 carbon atoms or a fluoroalkyl group having 1 to 3 carbon atoms, more preferably a methyl group, an ethyl group, a trifluoromethyl group or a pentafluoroethyl group, and even more preferably a methyl group, a trifluoromethyl group or a pentafluoroethyl group.

[0052] R 4 The alkyl ester group may be linear or branched.

[0053] R 4 Examples of the substituent that the amide group or amino group may have include an alkyl group, an alkoxy group, and a hydroxy group.

[0054] R 4 are each independently preferably a fluorine atom, a hydrogen atom, a hydroxyl group, an aldehyde group, a carboxylic acid group, an alkyl ester group having 1 to 10 carbon atoms, an amide group which may have a substituent, or an amino group which may have a substituent, and more preferably a fluorine atom. R 4 is a fluorine atom, R 4 -Rb 4 and Rb 4 -R 4 , i.e., R 4 -Rf 1 and Rf 2 -R 4 may each independently be a group selected from the group consisting of -CF3, -CF2CF3, and -CF2CF2CF3.

[0055] The fluoropolyether is particularly preferably the fluoropolyether represented by the formula (1) above, since it has good sheet strength and the like.

[0056] The above fluoropolyether is preferably liquid at any temperature between 25°C and 80°C in view of good sheet strength and the like. Examples of a form that is "liquid at any temperature between 25°C and 80°C" include a form that is solid at 25°C and liquid at 50°C, and a form that is solid at 50°C and liquid at 80°C. A form that is liquid at low temperatures and solid at high temperatures does not normally exist, and therefore is not included in the form that is "liquid at any temperature between 25°C and 80°C".

[0057] In the mixture for electrochemical devices of the present disclosure, the content of the fluoropolyether is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less.

[0058] The fibrillating resin is a resin that easily fibrillates when shear stress is applied, and examples thereof include liquid crystal polymer (LCP), cellulose, acrylic resin, ultra-high molecular weight polyethylene, polytetrafluoroethylene (PTFE), etc. These may be used alone or in combination of two or more. Among these, PTFE is preferred from the viewpoints of chemical stability, thermal stability, and processability.

[0059] The PTFE may be a homopolymer of tetrafluoroethylene (TFE), or may be a modified PTFE containing polymerized units based on TFE (TFE units) and polymerized units based on a modified monomer (hereinafter also referred to as "modified monomer units"). The modified PTFE may contain 99.0% by mass or more of TFE units and 1.0% by mass or less of modified monomer units. Alternatively, the modified PTFE may consist only of TFE units and modified monomer units. The PTFE is preferably the modified PTFE, as it improves the binding force, sheet strength, and flexibility.

[0060] The modified PTFE preferably has a modified monomer unit content of 0.00001 to 1.0% by mass relative to the total polymerized units, in terms of improving binding strength, sheet strength, and flexibility. The lower limit of the modified monomer unit content is more preferably 0.0001% by mass, even more preferably 0.001% by mass, even more preferably 0.005% by mass, and especially preferably 0.010% by mass. The upper limit of the modified monomer unit content is preferably 0.90% by mass, more preferably 0.80% by mass, more preferably 0.50% by mass, even more preferably 0.40% by mass, and even more preferably 0.30% by mass. In this specification, the modified monomer unit means a part of the molecular structure of PTFE that is derived from the modified monomer.

[0061] The content of each of the above-mentioned polymer units can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis depending on the type of monomer.

[0062] The modifying monomer is not particularly limited as long as it is copolymerizable with TFE, and examples thereof include perfluoroolefins such as hexafluoropropylene (HFP), hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride (VDF), perhaloolefins such as chlorotrifluoroethylene (CTFE), perfluorovinyl ether, perfluoroallyl ether, (perfluoroalkyl)ethylene, ethylene, etc. The modifying monomer used may be one type or multiple types.

[0063] The perfluorovinyl ether is not particularly limited, and examples thereof include perfluorovinyl ethers represented by the following general formula (A): CF2=CF-ORff (A) (wherein Rff represents a perfluoroorganic group). In this specification, the term "perfluoroorganic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. The perfluoroorganic group may have an ether oxygen.

[0064] An example of the perfluorovinyl ether is perfluoro(alkyl vinyl ether) [PAVE], where Rff in the general formula (A) is a perfluoroalkyl group having 1 to 10 carbon atoms. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 5.

[0065] Examples of the perfluoroalkyl group in the PAVE include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group.

[0066] The perfluorovinyl ether further includes those in which Rff in the general formula (A) is a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms, and those in which Rff ...

[0067] [ka]

[0068] (wherein m represents 0 or an integer of 1 to 4), and Rff is a group represented by the following formula:

[0069] [ka]

[0070] (wherein n represents an integer of 1 to 4).

[0071] The (perfluoroalkyl)ethylene [PFAE] is not particularly limited, and examples thereof include (perfluorobutyl)ethylene [PFBE] and (perfluorohexyl)ethylene.

[0072] Examples of perfluoroallyl ethers include those represented by the general formula (B): CF2=CF-CF2-ORff 1 (B) (In the formula, Rff1 represents a perfluoroorganic group.

[0073] Above Rff 1 is preferably a perfluoroalkyl group having 1 to 10 carbon atoms or a perfluoroalkoxyalkyl group having 1 to 10 carbon atoms. The perfluoroallyl ether is preferably at least one selected from the group consisting of CF2=CF-CF2-O-CF3, CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9, more preferably at least one selected from the group consisting of CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9, and even more preferably CF2=CF-CF2-O-CF2CF2CF3.

[0074] The modified monomer is preferably at least one selected from the group consisting of PAVE, HFP, VDF, and CTFE, and more preferably at least one selected from the group consisting of perfluoro(methyl vinyl ether) [PMVE], HFP, VDF, and CTFE, in terms of improving the stretchability, binding strength, and flexibility of the composite sheet.

[0075] The PTFE may have a core-shell structure. Examples of PTFE having a core-shell structure include modified PTFE particles containing a core of high molecular weight PTFE and a shell of lower molecular weight PTFE or modified PTFE. Examples of such modified PTFE include the PTFE described in JP-A-2005-527652.

[0076] Examples of commonly available PTFE include F-104, F-106, F-107, F-104C, F-121, F-201, F-205, F-208, and F-302 manufactured by Daikin Industries, Ltd.; 60X, 601X, 602X, 605XTX, 613AX, 62X, 62NX, 62XTX, 640XTX, 641XTX, 650XTX, 669X, 669NX, 6CX, 6CNX, CFP6000X, 6J, 6CJ, 62J, 640J, and 641J manufactured by Chemours; and T manufactured by 3M. F2029, TF2025Z, TF2053Z, TF2073Z, TF2001Z, TF2071USZ, TF2072Z, etc.; CD145, CD123, CD126E, CD097, CD084E, CD086EL, CD086EH, CD090E, CD122E, CD141E, CD127E, etc. manufactured by AGC; and DF681F, DF680F, DF330F, DF291F, DF230F, DF210F, DF132F, DF130F, DF120F manufactured by Solvay.

[0077] The PTFE preferably has an endothermic peak temperature of 320° C. or higher, more preferably 325° C. or higher, even more preferably 330° C. or higher, even more preferably 335° C. or higher, even more preferably 340° C. or higher, even more preferably 342° C. or higher, and particularly preferably 344° C. or higher, in that a mixture sheet having even greater strength can be formed. The endothermic peak temperature is also preferably 350° C. or lower. The endothermic peak temperature is the temperature corresponding to the minimum point in the heat of fusion curve obtained by performing differential scanning calorimetry (DSC) at a heating rate of 10°C / min on PTFE that has not been heated to a temperature of 300°C or higher. When there are two or more minimum points in one melting peak, each of them is regarded as an endothermic peak temperature.

[0078] The above-mentioned PTFE preferably exhibits one or more endothermic peaks in the range of 333 to 347°C in a heat of fusion curve when heated at a rate of 10°C / min using a differential scanning calorimeter (DSC), and the heat of fusion between 290 and 350°C calculated from the heat of fusion curve is 62 mJ / mg or more.

[0079] In the mixture for electrochemical devices of the present disclosure, the content of the fibrillar resin is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0080] The electrochemical device material may be, for example, an electrode active material. That is, the mixture for electrochemical devices according to the present disclosure may be an electrode mixture containing an electrode active material.

[0081] The electrode active material may be a positive electrode active material or a negative electrode active material.

[0082] The positive electrode active material is not particularly limited as long as it can electrochemically absorb and release alkali metal ions, but for example, a material containing an alkali metal and at least one transition metal is preferred. Specific examples include alkali metal-containing transition metal composite oxides and alkali metal-containing transition metal phosphate compounds. Of these, alkali metal-containing transition metal composite oxides that generate high voltage are particularly preferred as the positive electrode active material. Examples of the alkali metal ions include lithium ions, sodium ions, and potassium ions, with lithium ions being preferred.

[0083] Examples of the alkali metal-containing transition metal composite oxide include: Formula: M a Mn 2-b M 1 b O4 (Wherein, M is at least one metal selected from the group consisting of Li, Na, and K; 0.9≦a; 0≦b≦1.5; M 1 and (wherein at least one metal is selected from the group consisting of Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si, and Ge), a lithium-manganese spinel composite oxide represented by the formula (I). Formula:MNi 1-c M2 c O2 (Wherein, M is at least one metal selected from the group consisting of Li, Na, and K; 0≦c≦0.5; M 2 is at least one metal selected from the group consisting of Fe, Co, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si, and Ge), or Formula:MCo 1-d M 3 d O2 (Wherein, M is at least one metal selected from the group consisting of Li, Na, and K; 0≦d≦0.5; M 3 is at least one metal selected from the group consisting of Fe, Ni, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si, and Ge. In the above, M is preferably one metal selected from the group consisting of Li, Na, and K, more preferably Li or Na, and even more preferably Li.

[0084] Among these, MCoO2, MMnO2, MNiO2, MMn2O4, and MNi are the most popular because they can provide high energy density and high output secondary batteries. 0.8 Mn 0.1 Co 0.1 O2, MNi 0.8 Co 0.15 Al 0.05 O2 or MNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, etc. are preferred, and compounds represented by the following general formula are preferred. 0.8 Mn 0.1 Co 0.1 O2 is particularly preferred. MNi h Co i Mn j M 5 k O2 (In the formula, M is at least one metal selected from the group consisting of Li, Na, and K, and M5 represents at least one element selected from the group consisting of Fe, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si, and Ge, and (h+i+j+k)=1.0, 0≦h≦1.0, 0≦i≦1.0, 0≦j≦1.5, and 0≦k≦0.2.

[0085] Examples of the alkali metal-containing transition metal phosphate compound include compounds represented by the following general formula: M e M 4 f (PO4) g (In the formula, M is at least one metal selected from the group consisting of Li, Na, and K, and M 4 represents at least one selected from the group consisting of V, Ti, Cr, Mn, Fe, Co, Ni, and Cu, and 0.5≦e≦3, 1≦f≦2, and 1≦g≦3. In the above, M is preferably one metal selected from the group consisting of Li, Na, and K, more preferably Li or Na, and even more preferably Li.

[0086] The transition metal in the alkali metal-containing transition metal phosphate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. Specific examples include iron phosphates such as LiFePO4, Li3Fe2(PO4)3, and LiFeP2O7, cobalt phosphates such as LiCoPO4, and lithium transition metal phosphate compounds in which a portion of the main transition metal atoms is substituted with other elements such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, and Si. The lithium-containing transition metal phosphate compound is preferably one having an olivine structure, with LiFePO4 being particularly preferred.

[0087] Other examples of the positive electrode active material include lithium-nickel composite oxides. The lithium-nickel composite oxides are represented by the following general formula: Li y Ni 1-x M x O2 (wherein x is 0.01≦x≦0.7, y is 0.9≦y≦2.0, and M is a metal atom (excluding Li and Ni)) is preferred.

[0088] Other positive electrode active materials include MFePO4 and MNi 0.8 Co 0.2 O2, M 1.2 Fe 0.4 Mn 0.4 O2, MNi 0.5 Mn 1.5 O2, MV3O6, M2MnO3, etc. In particular, M2MnO3, MNi 0.5 Mn 1.5 A positive electrode active material such as O2 is preferable because the crystal structure does not collapse even when the secondary battery is operated at a voltage exceeding 4.4 V or at a voltage of 4.6 V or higher. Therefore, an electrochemical device such as a secondary battery using a positive electrode material containing the above-mentioned positive electrode active material is preferable because the remaining capacity is less likely to decrease and the rate of increase in resistance is less likely to change even when stored at high temperatures, and the battery performance does not deteriorate even when operated at high voltages.

[0089] Other positive electrode active materials include M2MnO3 and MM 6 O2 (wherein M is at least one metal selected from the group consisting of Li, Na, and K, and M 6 Examples of the material include solid solution materials with transition metals such as Co, Ni, Mn, and Fe.

[0090] The solid solution material may be, for example, a material represented by the general formula M x [Mn (1-y) M 7 y ]O z In the formula, M is at least one metal selected from the group consisting of Li, Na, and K, and M 7It consists of at least one metal element other than M and Mn, and contains, for example, one or more elements selected from the group consisting of Co, Ni, Fe, Ti, Mo, W, Cr, Zr, and Sn. Also, the values of x, y, and z in the formula are in the range of 1 < x < 2, 0 ≤ y < 1, and 1.5 < z < 3. Among them, Li 1.2 Mn 0.5 Co 0.14 Ni 0.14 A manganese-containing solid solution material in which LiNiO2 or LiCoO2 is solid-solved based on Li2MnO3 such as Li 0.33 Mn 0.33 Co 0.33 O2 is preferable because it can provide an alkali metal ion secondary battery having a high energy density.

[0091] Also, it is preferable to include lithium phosphate in the positive electrode active material because the continuous charging characteristics are improved. There is no limitation on the use of lithium phosphate, but it is preferable to mix and use the above-mentioned positive electrode active material and lithium phosphate. The amount of lithium phosphate used is preferably at least 0.1% by mass, more preferably at least 0.3% by mass, and still more preferably at least 0.5% by mass, and the upper limit is preferably at most 10% by mass, more preferably at most 8% by mass, and still more preferably at most 5% by mass, based on the total of the above-mentioned positive electrode active material and lithium phosphate.

[0092] Also, a material in which a substance having a different composition adheres to the surface of the above-mentioned positive electrode active material may be used. Examples of the surface adherent substance include oxides such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, and bismuth oxide; sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, and aluminum sulfate; carbonates such as lithium carbonate, calcium carbonate, and magnesium carbonate; and carbon.

[0093] The above-mentioned positive electrode active material may be used alone, or two or more kinds having different compositions may be used in combination in any combination or ratio. Preferred combinations in this case include LiCoO2 and LiNi 0.33 Co 0.33 Mn 0.33Examples of such a combination include a combination with a ternary system such as O2, a combination of LiCoO2 and LiMn2O4 or a combination in which part of the Mn has been replaced with another transition metal, or a combination of LiFePO4 and LiCoO2 or a combination in which part of the Co has been replaced with another transition metal.

[0094] The content of the positive electrode active material is preferably 50 to 90% by mass of the positive electrode mixture in terms of high battery capacity. The content in the positive electrode active material layer is preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 75% by mass or more. The upper limit is preferably 88% by mass or less, more preferably 86% by mass or less. If the content of the positive electrode active material in the positive electrode active material layer is low, the electrical capacity may be insufficient. Conversely, if the content is too high, the ionic conductivity, electronic conductivity, and electrode strength may be insufficient.

[0095] The negative electrode active material is not particularly limited, and examples thereof include carbonaceous materials such as lithium metal, artificial graphite, graphite carbon fiber, resin-baked carbon, pyrolytic vapor-grown carbon, coke, mesocarbon microbeads (MCMB), furfuryl alcohol resin-baked carbon, polyacene, pitch-based carbon fiber, vapor-grown carbon fiber, natural graphite, and non-graphitizable carbon; silicon-containing compounds such as silicon and silicon alloys; and Li4Ti5O 12 Among them, those containing at least a carbonaceous material and silicon-containing compounds are particularly suitable.

[0096] The negative electrode active material used in the present disclosure preferably contains silicon as a constituent element, which allows the production of a high-capacity battery.

[0097] The silicon-containing material includes silicon particles, particles having a structure in which silicon particles are dispersed in a silicon-based compound, and silicon-based particles having the general formula SiO xSilicon oxide particles represented by the formula (0.5≦x≦1.6), or a mixture thereof, are preferred. By using these, a negative electrode mixture for a lithium ion secondary battery having higher initial charge / discharge efficiency, high capacity, and excellent cycle characteristics can be obtained.

[0098] Silicon oxide in the present disclosure is a general term for amorphous silicon oxide, and silicon oxide before disproportionation has the general formula SiO x (0.5≦x≦1.6), where x is preferably 0.8≦x<1.6, and more preferably 0.8≦x<1.3. This silicon oxide can be obtained, for example, by heating a mixture of silicon dioxide and metallic silicon to produce silicon monoxide gas, and then cooling and precipitating the gas.

[0099] The content of the negative electrode active material is preferably 50 to 90% by mass of the negative electrode mixture in terms of high battery capacity. The content in the negative electrode active material layer is preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 75% by mass or more. The upper limit is preferably 88% by mass or less, more preferably 86% by mass or less. If the content of the negative electrode active material in the negative electrode active material layer is low, the electrical capacity may be insufficient. Conversely, if the content is too high, the ionic conductivity, electronic conductivity, and electrode strength may be insufficient.

[0100] The electrochemical device material may be a solid electrolyte. That is, the mixture for an electrochemical device according to the present disclosure may be a solid electrolyte mixture containing a solid electrolyte.

[0101] The solid electrolyte may be a sulfide-based solid electrolyte or an oxide-based solid electrolyte. In particular, when a sulfide-based solid electrolyte is used, it has the advantage of being flexible.

[0102] The sulfide-based solid electrolyte is not particularly limited and may be Li2S-P2S5, Li2S-P2S3, Li2S-P2S3-P2S5, Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, LiI-Li2S-SiS2-P2S5, Li2S-SiS2-Li4SiO4, Li2S-SiS2-Li3PO4, Li3PS4-Li4GeS4, Li 3.4 P 0.6 Si 0.4 S4, Li 3.25 P 0.25 Ge 0.76 S4, Li 4-x Ge 1-x P x S4(x=0.6~0.8), Li 4+y Ge 1-y Ga y S4(y=0.2~0.3), LiPSCl, LiCl, Li 7-x-2y PS 6-x-y Cl x (0.8≦x≦1.7, 0 <y≦-0.25x+0.5)、Li 10 SnP2S 12 Any one selected from the above, or a mixture of two or more thereof, can be used.

[0103] The sulfide-based solid electrolyte preferably contains lithium. Sulfide-based solid electrolytes containing lithium are used in solid-state batteries that use lithium ions as a carrier, and are particularly preferred in terms of electrochemical devices having high energy density.

[0104] In the mixture for electrochemical devices according to the present disclosure, the content of the solid electrolyte is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, and is preferably 99% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0105] The mixture for electrochemical devices according to the present disclosure may be an electrode mixture for a solid battery containing an electrode active material and a solid electrolyte.

[0106] In the electrochemical device mixture of the present disclosure, the content of the electrochemical device material is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and is preferably 99.5% by mass or less, more preferably 98.5% by mass or less, and even more preferably 97.5% by mass or less.

[0107] In the mixture for electrochemical devices of the present disclosure, the content of the polyalkylene oxide represented by the following formula (6) is preferably less than 20% by mass. This ensures good ionic conductivity. If the content is 20% by mass or more, the viscosity of the composition increases, the ionic conductivity decreases, and the electrochemical stability tends to decrease. (6)R 1B -(OCHR 1A (CH2)jCHR 2A )n-OR 2B (In the formula, R 1A and R 2A are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, j is 0 or an integer of 1 to 2, R 1B and R 2B are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, n is an integer from 5 to 1000.

[0108] In the mixture for electrochemical devices of the present disclosure, the content of the polyalkylene oxide represented by the above formula (6) is more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 1% by mass or less. The lower limit is not particularly limited, and may be 0% by mass.

[0109] The mixture for electrochemical devices of the present disclosure may contain a lithium salt. By containing a lithium salt, the conductivity of lithium ions is improved.

[0110] Any lithium salt can be used, and specific examples include the following: LiPF6, LiBF4, LiClO4, LiAlF4, LiSbF6, LiTaF6, LiWF7, LiAsF6, LiAlCl4, LiI, LiBr, LiCl, LiB 10 Cl 10 Inorganic lithium salts such as Li2SiF6, Li2PFO3, LiPO2F2, etc.; Lithium tungstates such as LiWOF5; Lithium carboxylates such as HCO2Li, CH3CO2Li, CH2FCO2Li, CHF2CO2Li, CF3CO2Li, CF3CH2CO2Li, CF3CF2CO2Li, CF3CF2CF2CO2Li, CF3CF2CF2CF2CO2Li; Lithium salts having an S=O group, such as FSO3Li, CH3SO3Li, CH2FSO3Li, CHF2SO3Li, CF3SO3Li, CF3CF2SO3Li, CF3CF2CF2SO3Li, CF3CF2CF2CF2SO3Li, lithium methyl sulfate, lithium ethyl sulfate (C2H5OSO3Li), and lithium 2,2,2-trifluoroethyl sulfate; Lithium imide salts such as lithium bis(trifluoromethanesulfonimide) (LiTFSI), lithium bis(monofluorosulfonimide) (LiFSI), LiN(FCO)2, LiN(FCO)(FSO2), LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2)2, lithium bisperfluoroethanesulfonylimide, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide, lithium cyclic 1,2-ethanedisulfonylimide, lithium cyclic 1,3-propanedisulfonylimide, lithium cyclic 1,4-perfluorobutanedisulfonylimide, LiN(CF3SO2)(FSO2), LiN(CF3SO2)(C3F7SO2), LiN(CF3SO2)(C4F9SO2), and LiN(POF2)2; Lithium methide salts such as LiC(FSO2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3; Other, formula: LiPF a (C n F 2n+1 ) 6-a (wherein a is an integer of 0 to 5, and n is an integer of 1 to 6) (for example, fluorine-containing organic lithium salts such as LiPF3(C2F5)3, LiPF3(CF3)3, LiPF3(iso-C3F7)3, LiPF5(iso-C3F7), LiPF4(CF3)2, LiPF4(C2F5)2), LiPF4(CF3SO2)2, LiPF4(C2F5SO2)2, LiBF3CF3, LiBF3C2F5, LiBF3C3F7, LiBF2(CF3)2, LiBF2(C2F5)2, LiBF2(CF3SO2)2, and LiBF2(C2F5SO2)2, LiSCN, LiB(CN)4, LiB(C6H5)4, Li2(C2O4), LiP(C2O4)3, Li2B 12 F b H 12-b (b is an integer of 0 to 3), etc.

[0111] Among these, LiTFSI, LiFSI, LiPF6, LiBF4, LiSbF6, LiTaF6, LiPO2F2, FSO3Li, CF3SO3Li, LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2)2, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide, LiC(FSO2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3, LiBF3CF3, LiBF3C2F5, LiPF3(CF3)3, LiPF3(C2F5)3, and the like are preferred, with LiTFSI, LiFSI, and LiPF6 being particularly preferred.

[0112] These lithium salts may be used alone or in combination of two or more. A preferred example of a combination of two or more is a combination of LiPF6 and LiBF4, or a combination of LiPF6 and LiPO2F2, C2H5OSO3Li or FSO3Li, which has the effect of improving high-temperature storage characteristics, load characteristics and cycle characteristics.

[0113] Another example is the combined use of an inorganic lithium salt and an organic lithium salt, which has the effect of suppressing deterioration due to high-temperature storage. Preferred organic lithium salts include CF3SO3Li, LiN(FSO2), LiN(FSO2)(CF3SO2), LiN(CF3SO2), LiN(C2F5SO2), lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide, LiC(FSO2), LiC(CF3SO2), LiC(C2F5SO2), LiBF3CF3, LiBF3C2F5, LiPF3(CF3), and LiPF3(C2F5)3.

[0114] In the mixture for electrochemical devices of the present disclosure, the content of the lithium salt is preferably 0.1% by mass or more, more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less.

[0115] The mixture for electrochemical devices of the present disclosure may contain a conductive assistant. The conductive additive is not particularly limited, but examples thereof include metal materials such as copper, nickel, gold, etc., graphite such as natural graphite and artificial graphite, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, etc., and carbon materials such as needle coke, carbon nanotubes, fullerene, and amorphous carbon such as VGCF, etc. These may be used alone or in any combination and ratio of two or more.

[0116] In the mixture for electrochemical devices of the present disclosure, the content of the conductive auxiliary is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, and is preferably 30% by mass or less, more preferably 15% by mass or less, even more preferably 5% by mass or less.

[0117] In the mixture for electrochemical devices of the present disclosure, the fibrillar resin acts as a binder, but the mixture may further contain other binders. The other binders are not particularly limited, but examples thereof include resin polymers such as polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, chitosan, alginic acid, polyacrylic acid, polyimide, cellulose, and nitrocellulose; rubber-like polymers such as SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), and ethylene-propylene rubber; styrene-butadiene-styrene block copolymers or hydrogenated products thereof; and EPDM (ethylene-propylene copolymer). Examples of suitable polymers include thermoplastic elastomeric polymers such as styrene-ethylene-butadiene terpolymers, styrene-isoprene-styrene block copolymers, and hydrogenated products thereof; soft resinous polymers such as syndiotactic 1,2-polybutadiene, polyvinyl acetate, ethylene-vinyl acetate copolymers, and propylene-α-olefin copolymers; fluorinated polymers such as polyvinylidene fluoride, vinylidene fluoride copolymers, and tetrafluoroethylene-ethylene copolymers; and polymer compositions having ionic conductivity for alkali metal ions (especially lithium ions). These may be used alone or in any combination and ratio of two or more.

[0118] In the mixture for electrochemical devices of the present disclosure, the content of the other binder is usually 0.01 to 3 mass %.

[0119] <Compound sheet for electrochemical devices> The mixture for electrochemical devices of the present disclosure is preferably in the form of a sheet. The present disclosure also relates to a mixture sheet for an electrochemical device, which includes the mixture for an electrochemical device of the present disclosure.

[0120] The thickness of the composite sheet for electrochemical devices of the present disclosure is preferably 300 μm or less, more preferably 250 μm or less, even more preferably 200 μm or less, even more preferably 180 μm or less, particularly preferably 150 μm or less, and is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more.

[0121] The mixture sheet for electrochemical devices according to the present disclosure can be used as a solid electrolyte mixture sheet or an electrode mixture sheet.

[0122] <Method of manufacturing a composite sheet for electrochemical devices> The electrochemical device mixture sheet of the present disclosure can be obtained, for example, by a production method including a step (1) of mixing a fluoropolyether, a fibrillar resin, and a material for an electrochemical device, and a step (2) of rolling the electrochemical device mixture obtained in the step (1) into a sheet. The present disclosure also relates to such a manufacturing method.

[0123] The fluoropolyether, fibrillar resin, and material for electrochemical devices in the above step (1) are the same as those described for the mixture for electrochemical devices of the present disclosure.

[0124] In the above step (1), the mixing conditions are preferably 3000 rpm or less. The speed is preferably 10 rpm or more, more preferably 15 rpm or more, and even more preferably 20 rpm or more, and is preferably 2000 rpm or less, more preferably 1500 rpm or less, and even more preferably 1000 rpm or less. Mixing below this range takes a long time, affecting productivity. Furthermore, exceeding this range may result in excessive fibrillation, resulting in a mixture sheet with poor strength and flexibility.

[0125] In the above step (1), the materials may be mixed and then shaped into a bulk form. Specific methods for shaping into a bulk form include extrusion molding, press molding, and the like. The term "bulk form" does not specify a specific shape, and may refer to a single mass, including rods, sheets, spheres, cubes, and the like.

[0126] Specific examples of the rolling method in the above step (2) include rolling methods using a roll press, a plate press, a calender roll, or the like.

[0127] Furthermore, after the above step (2), step (3) may be carried out in which a larger load is applied to the obtained rolled sheet to roll it into an even thinner sheet, or step (3) may be carried out repeatedly. In this way, by rolling the rolled sheet little by little in stages rather than thinning it all at once, flexibility is improved. The number of times step (3) is carried out is preferably from 2 to 10 times, and more preferably from 3 to 9 times. Specific rolling methods include, for example, a method in which two or more rolls are rotated and the rolled sheet is passed between them to process it into an even thinner sheet.

[0128] It is also preferable to include a step (4) after the step (2) or the step (3) in which the rolled sheet is crushed, re-formed into a bulk form, and rolled into a sheet. It is also preferable to repeat the step (4). The number of times of the step (4) is preferably from 1 to 12 times, more preferably from 2 to 11 times.

[0129] In the above step (4), specific methods for roughly crushing the rolled sheet and forming it into a bulk form include folding the sheet, forming it into a rod or thin film sheet, chipping, etc. In the present disclosure, "rough crushing" means changing the form of the rolled sheet obtained in step (2) or (3) into a different form so that it can be rolled into a sheet in the next step, and also includes simply folding the rolled sheet.

[0130] Furthermore, step (4) may be followed by step (3) or may be repeated. Furthermore, uniaxial or biaxial stretching may be performed in steps (2), (3), and (4).

[0131] In the above steps (2), (3), and (4), the rolling ratio is preferably 10% or more, more preferably 20% or more, and preferably 80% or less, more preferably 65% ​​or less, and even more preferably 50% or less. If the rolling ratio is below the above range, the number of rolling operations increases, which takes more time and affects productivity. If the rolling ratio is above the above range, fibrillation may proceed excessively, resulting in a mixture sheet with poor strength and flexibility. The rolling ratio here refers to the reduction in thickness of the sample after rolling relative to the thickness before rolling. The sample before rolling may be a bulk raw material composition or a sheet-like raw material composition. The thickness of the sample refers to the thickness in the direction in which a load is applied during rolling.

[0132] <Electrochemical devices> The present disclosure also relates to an electrochemical device using the mixture sheet for an electrochemical device of the present disclosure.

[0133] The electrochemical device of the present disclosure may use the mixture sheet for electrochemical device of the present disclosure as an electrode mixture sheet, may use the mixture sheet for electrochemical device of the present disclosure as a solid electrolyte mixture sheet, or may use the mixture sheet as both an electrode mixture sheet and a solid electrolyte mixture sheet.

[0134] The electrochemical device of the present disclosure preferably comprises a positive electrode, a negative electrode, etc., and more specifically, is preferably a secondary battery comprising these, and particularly preferably a lithium ion secondary battery.

[0135] The positive electrode is preferably composed of a current collector and an electrode mixture sheet containing the positive electrode active material. Examples of materials for the positive electrode current collector include metals such as aluminum, titanium, tantalum, stainless steel, and nickel, or alloys thereof; and carbon materials such as carbon cloth and carbon paper. Among these, metal materials, particularly aluminum or its alloys, are preferred.

[0136] Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, expanded metal, punched metal, and foam metal for metal materials, and carbon plate, carbon thin film, and carbon cylinder for carbon materials. Of these, metal foil is preferred. The metal foil may be formed into a mesh shape as appropriate. The thickness of the metal foil is optional, but is usually 1 μm or more, preferably 3 μm or more, and more preferably 5 μm or more, and is usually 1 mm or less, preferably 100 μm or less, and more preferably 50 μm or less. If the metal foil is thinner than this range, the strength required as a current collector may be insufficient. Conversely, if the metal foil is thicker than this range, handling may be impaired.

[0137] In addition, it is also preferable that the surface of the current collector is coated with a conductive additive, from the viewpoint of reducing the electrical contact resistance between the current collector and the positive electrode active material layer. Examples of the conductive additive include carbon and precious metals such as gold, platinum, and silver.

[0138] The positive electrode may be manufactured by a conventional method, for example, by laminating an electrode mixture sheet and a current collector with an adhesive therebetween, followed by vacuum drying.

[0139] The density of the positive electrode mixture sheet is preferably 2.80 g / cm 3 More preferably, 3.00 g / cm 3 More preferably, 3.20 g / cm 3 or more, and preferably 3.80 g / cm 3 or less, more preferably 3.75 g / cm 3 More preferably, 3.70 g / cm or less 3The range is as follows. If the temperature exceeds this range, the permeability of the electrolyte near the current collector / active material interface will decrease, which may result in a decrease in charge / discharge characteristics, especially at high current densities, and high output may not be obtained. If the temperature falls below this range, the conductivity between the active materials will decrease, which may increase the battery resistance and prevent high output.

[0140] The negative electrode is preferably composed of a current collector and an electrode mixture sheet containing the negative electrode active material. Examples of materials for the negative electrode current collector include metals such as copper, nickel, titanium, tantalum, and stainless steel, or alloys thereof; and carbon materials such as carbon cloth and carbon paper. Among these, metal materials, particularly copper, nickel, and alloys thereof, are preferred.

[0141] Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, expanded metal, punched metal, and foam metal for metal materials, and carbon plate, carbon thin film, and carbon cylinder for carbon materials. Of these, metal foil is preferred. The metal foil may be formed into a mesh shape as appropriate. The thickness of the metal foil is optional, but is usually 1 μm or more, preferably 3 μm or more, and more preferably 5 μm or more, and is usually 1 mm or less, preferably 100 μm or less, and more preferably 50 μm or less. If the metal foil is thinner than this range, the strength required as a current collector may be insufficient. Conversely, if the metal foil is thicker than this range, handling may be impaired.

[0142] The negative electrode may be produced by a conventional method, for example, by laminating the electrode mixture sheet and a current collector with an adhesive therebetween, followed by vacuum drying.

[0143] The density of the negative electrode mixture is preferably 1.3 g / cm 3 More preferably, 1.4 g / cm 3 More preferably, 1.5 g / cm 3 or more, and preferably 2.0 g / cm 3 or less, more preferably 1.9 g / cm 3 More preferably 1.8 g / cm or less 3The range is as follows. If the temperature exceeds this range, the permeability of the electrolyte near the current collector / active material interface will decrease, which may result in a decrease in charge / discharge characteristics, especially at high current densities, and high output may not be obtained. If the temperature falls below this range, the conductivity between the active materials will decrease, which may increase the battery resistance and prevent high output.

[0144] The secondary battery may be a secondary battery that uses an electrolytic solution or a solid secondary battery. In this specification, the solid-state secondary battery may be a secondary battery containing a solid electrolyte, and may be a semi-solid-state secondary battery containing a solid electrolyte and a liquid component as the electrolyte, or an all-solid-state secondary battery containing only a solid electrolyte as the electrolyte.

[0145] The secondary battery using the above-mentioned electrolyte solution can use the electrolyte solution, separator, etc. used in known secondary batteries, which will be described in detail below.

[0146] The electrolyte is preferably a non-aqueous electrolyte, which may be prepared by dissolving a known electrolyte salt in a known organic solvent for dissolving electrolyte salts.

[0147] The organic solvent for dissolving the electrolyte salt is not particularly limited, and one or more of known hydrocarbon solvents such as propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, 1,2-dimethoxyethane, 1,2-diethoxyethane, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; and fluorine-containing solvents such as fluoroethylene carbonate, fluoroethers, and fluorinated carbonates can be used.

[0148] As the electrolyte salt, the above-mentioned lithium salt can be used.

[0149] The concentration of the electrolyte salt is preferably 0.8 mol / L or more, more preferably 1.0 mol / L or more, and the upper limit is usually 1.5 mol / L or less, although it depends on the organic solvent used to dissolve the electrolyte salt.

[0150] A secondary battery using the above-mentioned electrolyte solution preferably further includes a separator. The material and shape of the separator are not particularly limited as long as it is stable to the electrolyte solution and has excellent liquid retention properties, and any known separator can be used. Among them, it is preferable to use a material that is stable to the electrolyte solution, such as resin, glass fiber, or inorganic material, and that is in the form of a porous sheet or nonwoven fabric with excellent liquid retention properties.

[0151] Examples of materials that can be used for the resin or glass fiber separator include polyolefins such as polyethylene and polypropylene, aromatic polyamides, polytetrafluoroethylene, polyethersulfone, and glass filters. These materials may be used alone or in any combination and ratio, such as polypropylene / polyethylene two-layer films and polypropylene / polyethylene / polypropylene three-layer films. Among these, porous sheets or nonwoven fabrics made from polyolefins such as polyethylene and polypropylene are preferred for the separator, due to their excellent electrolyte permeability and shutdown effect.

[0152] The thickness of the separator is optional, but is usually 1 μm or more, preferably 5 μm or more, more preferably 8 μm or more, and usually 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. If the separator is thinner than the above range, the insulating properties and mechanical strength may be reduced. On the other hand, if the separator is thicker than the above range, not only may the battery performance such as rate characteristics be reduced, but also the energy density of the entire electrolyte battery may be reduced.

[0153] On the other hand, inorganic materials include, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate, and these are used in particulate or fibrous form.

[0154] As for the form, a thin film such as a nonwoven fabric, a woven fabric, or a microporous film is used. A thin film with a pore size of 0.01 to 1 μm and a thickness of 5 to 50 μm is preferably used. In addition to the above-mentioned independent thin film, a separator can be used in which a composite porous layer containing the above-mentioned inorganic particles is formed on the surface layer of the positive electrode and / or negative electrode using a resin binder. For example, a porous layer can be formed on both sides of the positive electrode using alumina particles with a 90% particle size of less than 1 μm and a fibrillar resin as a binder.

[0155] The material of the outer case is not particularly limited as long as it is stable against the electrolyte used. Specifically, metals such as nickel-plated steel sheet, stainless steel, aluminum or aluminum alloy, magnesium alloy, or a laminate film of resin and aluminum foil (laminate film) can be used. From the viewpoint of weight reduction, metals such as aluminum or aluminum alloy and laminate film are preferably used.

[0156] Examples of exterior cases using metals include those in which metals are welded together to form a sealed, airtight structure by laser welding, resistance welding, or ultrasonic welding, or those in which the metals are used via a resin gasket to form a crimped structure. Examples of exterior cases using the above-mentioned laminate film include those in which resin layers are heat-sealed to form a sealed, airtight structure. In order to improve sealing properties, a resin different from the resin used in the laminate film may be interposed between the resin layers. In particular, when a sealed structure is formed by heat-sealing the resin layers via a current collecting terminal, a resin having a polar group or a modified resin into which a polar group has been introduced is preferably used as the interposed resin, since the metal and the resin are bonded together.

[0157] The shape of the secondary battery using the above-mentioned electrolyte solution is arbitrary, and examples thereof include cylindrical, prismatic, laminated, coin, large, etc. The shapes and configurations of the positive electrode, negative electrode, and separator can be changed according to the shape of each battery.

[0158] The solid-state secondary battery is preferably an all-solid-state secondary battery, and is preferably a lithium-ion battery, and is also preferably a sulfide-based all-solid-state secondary battery.

[0159] The solid secondary battery preferably includes a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode.

[0160] The solid secondary battery may include a separator between the positive electrode and the negative electrode, such as a porous membrane of polyethylene or polypropylene, or a nonwoven fabric made of a resin such as polypropylene, or a glass fiber nonwoven fabric.

[0161] The solid secondary battery may further include a battery case. The shape of the battery case is not particularly limited as long as it can accommodate the above-mentioned positive electrode, negative electrode, solid electrolyte layer, etc., but specific examples include a cylindrical shape, a square shape, a coin shape, and a laminate shape.

[0162] The solid secondary battery can be produced, for example, by stacking a positive electrode, a solid electrolyte layer sheet, and a negative electrode in this order and pressing them together.

[0163] Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims. [Example]

[0164] Next, the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[0165] The following compounds were used: Compounds 1-1 to 1-7 were liquids at 25°C. <Compound 1-1> CH3O(CH2CH2O) x1 CH2CF2(OCF2CF2) y (OCF2) z OCF2CH2O(CH2CH2O)x2 CH3 (x1: 4, y: average 12.3, z: average 10.2, x2: 4, (CH2CH2O)x1 number average molecular weight: 176, (CH2CH2O) x2 Number average molecular weight: 176 <Compound 1-2> Compound with the same structure as compound 1-1 (x1: average 8.4, y: average 12.3, z: average 10.2, x2: average 8.4, (CH2CH2O) x1 Number average molecular weight: 400, (CH2CH2O) x2 Number average molecular weight: 400 <Compound 1-3> CF2(CF3)CF2(OCF(CF3)CF2) x OCF(CF3)CH2O(CH2CH2O) y CH3 (x: average 9.4, y: 4, (CH2CH2O) y Number average molecular weight: 176 <Compound 1-4> Compounds with the same structure as compounds 1-3 (x: average 14.3, y: 4, (CH2CH2O) y Number average molecular weight: 176 <Compound 1-5> Fluorolink E10H (Solvay) HO(CH2CH2O) x1 CH2CF2O(CF2CF2O) x2 (CF2O) y CF2CH2O(CH2CH2O) x3 H (x1: average 1.27, y: average 8.16, x2: average 7.09, x3: average 1.27) <Compound 1-6> CF3CF2(OCF2CF2) x1 (OCF2) y1 OCF2CH2O(CH2CH2O) z CH2CF2(OCF2CF2) x2 (OCF2) y2 OCF2CF3 (x1: average 15.5, y1: average 13.0, z: average 4.1, x2: average 15.5, y2: average 13.0, (CH2CH2O) z Number average molecular weight: 200 <Compound 1-7> A compound with the chemical structure represented by the following formula (I) (m: average 29.5, n: average 24.6, terminal R is CF3 and CF2CF3 in an average ratio of 1:0.17, number average molecular weight 5120)

[0166] [ka]

[0167] <Compound 2-1> Ethyl methyl carbonate (EMC, manufactured by Kishida Chemical Co., Ltd.) <Compound 2-2> Polyethylene glycol 200 (Tokyo Chemical Industry Co., Ltd.)

[0168] (Synthesis Example 1) Synthesis of Compound 1-1 A nitrogen-purged reaction vessel was charged with 600 mg of sodium hydroxide (Fujifilm Wako Pure Chemical Industries, Ltd., 15.3 mmol), 30 g of 1,3-bis(trifluoromethyl)benzene (Tokyo Chemical Industry Co., Ltd.), and 10 g of fluoropolyether-terminated alcohol (Solvay, Fomblin D2, 5.1 mmol) and heated and stirred at 70 °C for 3 hours. The internal temperature was raised to 65 °C, and 5.5 g of triethylene glycol-2-bromoethyl methyl ether (Tokyo Chemical Industry Co., Ltd., 20.4 mmol) was added dropwise over 10 minutes using a dropping funnel. The mixture was then heated and stirred for 6 hours. After returning to room temperature, 5 mL of 1N hydrochloric acid was added to the reaction solution and stirred for 3 hours. This solution was washed four times with pure water, and the separated organic layer was dried by adding 2 g of magnesium sulfate. The magnesium sulfate was removed by filtration, and the volatiles were removed from the treated solution by distillation. The mixture was then further dried at 100 °C for 3 hours to obtain compound 1-1.

[0169] (Synthesis Example 2) Synthesis of tosylated polyethylene glycol monomethyl ether A nitrogen-purged reaction vessel was charged with 8.0 g of polyethylene glycol monomethyl ether 400 (Tokyo Chemical Industry Co., Ltd., average molecular weight 380-420, 20.0 mmol), 25 mL of tetrahydrofuran (Tokyo Chemical Industry Co., Ltd.), and 4.7 g of p-toluenesulfonyl chloride (Tokyo Chemical Industry Co., Ltd., 25 mmol) and stirred until homogeneous. A solution of 3.4 g of potassium hydroxide (Fujifilm Wako Pure Chemical Industries, Ltd., 60 mmol) in 10 mL of pure water was added to the reaction vessel in an ice-water bath. After stirring for 10 minutes, the ice-water bath was removed and the mixture was stirred at room temperature for 12 hours. The reaction solution was poured into a mixture of 30 mL of ice water and 60 mL of methylene chloride, and the aqueous layer was extracted three times with methylene chloride. The separated organic layer was dried with 8 g of magnesium sulfate. The magnesium sulfate was removed by filtration, and the volatiles were evaporated to obtain the tosylated polyethylene glycol monomethyl ether.

[0170] (Synthesis Example 3) Synthesis of Compound 1-2 Compound 1-2 was obtained by reacting the tosylated polyethylene glycol monomethyl ether synthesized in Synthesis Example 2 under the reaction conditions of Synthesis Example 1, instead of triethylene glycol-2-bromoethyl methyl ether.

[0171] (Synthesis Example 4) Synthesis of Compound 1-3 A nitrogen-purged reaction vessel was charged with 600 mg of sodium hydroxide (Fujifilm Wako Pure Chemical Industries, Ltd., 15.3 mmol), 30 g of 1,3-bis(trifluoromethyl)benzene (Tokyo Chemical Industry Co., Ltd.), and 10.2 g of fluoropolyether monoterminated alcohol (Unichem Co., Ltd., perfluoropolyether modified, molecular weight 2000, 5.1 mmol) and heated and stirred at 70 °C for 3 hours. The internal temperature was raised to 65 °C, and 2.8 g of triethylene glycol-2-bromoethyl methyl ether (Tokyo Chemical Industry Co., Ltd., 10.0 mmol) was added dropwise over 10 minutes using a dropping funnel. The mixture was then heated and stirred for 6 hours. After returning to room temperature, 5 ml of 1N hydrochloric acid was added to the reaction solution and stirred for 3 hours. This solution was washed four times with pure water, and the separated organic layer was dried with 2 g of magnesium sulfate. The magnesium sulfate was removed by filtration, and the volatile matter was distilled off from the treated solution. The residue was then dried at 100°C for 3 hours to obtain compound 1-3.

[0172] (Synthesis Example 5) Synthesis of Compound 1-4 Compound 1-4 was obtained by carrying out the same reaction as in Synthesis Example 4, except that the fluoropolyether monoterminated alcohol was replaced with a perfluoropolyether modified product with a molecular weight of 3,000 manufactured by Unichem Co., Ltd.

[0173] (Synthesis Example 6) Synthesis of Compound 1-6 A nitrogen-purged reaction vessel was charged with 600 mg of sodium hydroxide (Fujifilm Wako Pure Chemical Industries, Ltd., 15.3 mmol), 30 g of 1,3-bis(trifluoromethyl)benzene (Tokyo Chemical Industry Co., Ltd.), and 20.4 g of a fluoropolyether mono-terminated alcohol (Fluorolink ZMF-402, Solvay, 5.1 mmol), followed by heating and stirring at 70°C for 3 hours. The internal temperature was raised to 65°C, and 1.3 g (2.5 mmol) of the polyethylene glycol (prepared in Synthesis Example 9) with both terminal tosylation was dissolved in 5 g of 1,3-bis(trifluoromethyl)benzene. This solution was then added dropwise over 10 minutes via a dropping funnel, followed by heating and stirring for 6 hours. After returning to room temperature, 5 ml of 1N hydrochloric acid was added to the reaction solution, followed by stirring for 3 hours. This solution was washed four times with pure water, and the separated organic layer was dried with 2 g of magnesium sulfate. The magnesium sulfate was removed by filtration, and the volatile matter was distilled off from the treated solution. The residue was then dried at 100°C for 3 hours to obtain compound 1-6.

[0174] PTFE-1 to PTFE-3 were prepared and analyzed by the following method.

[0175] <Average primary particle diameter> The PTFE aqueous dispersion was diluted with water to a solid content of 0.15% by mass, and the transmittance of the 550 nm incident light per unit length of the diluted latex obtained and the number-average primary particle diameter determined by measuring the unidirectional diameter using a transmission electron microscope photograph were measured to prepare a calibration curve. Using this calibration curve, the average primary particle diameter was determined from the measured transmittance of the 550 nm incident light of each sample.

[0176] <Polymer solids concentration> 1 g of the aqueous PTFE dispersion is dried in a blower dryer at 150°C for 60 minutes, and the ratio of the mass of the heating residue to the mass (1 g) of the aqueous dispersion is expressed as a percentage and used as the value.

[0177] <Modified Monomer Content> The CTFE content was determined by press-molding PTFE powder to produce a thin film disk, and measuring the infrared absorbance of the thin film disk using FT-IR. -1 Absorbance at / 2360cm-1 The absorbance ratio was calculated by multiplying the absorbance ratio at 0.58. The HFP content was determined by press-molding the PTFE composition to produce a thin film disk, and measuring the infrared absorbance of the thin film disk by FT-IR. -1 Absorbance at / 935cm -1 The absorbance ratio was calculated by multiplying the absorbance ratio by 0.3.

[0178] <Standard specific gravity (SSG)> Using samples molded in accordance with ASTM D4895 89, measurements were made by the water displacement method in accordance with ASTM D 792.

[0179] A white solid A was obtained by the method described in Synthesis Example 1 of WO 2021 / 045228.

[0180] (Production Example 1) A 6-liter stainless steel autoclave equipped with a stirring blade and a temperature-control jacket was charged with 3,480 g of deionized water, 100 g of paraffin wax, and 5.3 g of white solid A. The autoclave was heated to 70°C and the atmosphere was purged with nitrogen gas to remove oxygen. TFE was injected to adjust the system pressure to 0.78 MPaG, and the system temperature was maintained at 70°C while stirring. Next, an aqueous solution containing 15.0 mg of ammonium persulfate dissolved in 20 g of water was injected with TFE to initiate the polymerization reaction. As the polymerization reaction progressed, the system pressure decreased, but TFE was added to maintain the system temperature at 70°C and the system pressure at 0.78 MPaG. When 400 g of TFE had been consumed from the start of polymerization, an aqueous solution of 18.0 mg of hydroquinone as a radical scavenger dissolved in 20 g of water was injected with TFE. The polymerization continued, and when the amount of TFE polymerized reached approximately 1,200 g from the start of polymerization, stirring and the supply of TFE were stopped, and the gas in the system was immediately released to normal pressure, terminating the polymerization reaction. The aqueous dispersion was removed and cooled, and the paraffin wax was separated to obtain an aqueous PTFE dispersion. The average primary particle size of the resulting aqueous PTFE dispersion was 310 nm, and the solids concentration was 25.3 mass%.

[0181] The resulting aqueous PTFE dispersion was diluted to a solids concentration of 13% by mass, and the PTFE was solidified while being stirred in a container, and then the water was filtered off to obtain a wet PTFE powder. The obtained wet PTFE powder was dried at 180°C for 18 hours to obtain PTFE-1. The SSG of the resulting PTFE-1 was 2.156.

[0182] (Production Example 2) A 6-liter stainless steel autoclave equipped with a stirring blade and a temperature-control jacket was charged with 3580 g of deionized water, 100 g of paraffin wax, and 5.4 g of white solid A. The autoclave was heated to 80°C and the atmosphere was purged with nitrogen gas to remove oxygen. After adding 1.20 g of CTFE, additional TFE was added to bring the system pressure to 0.78 MPaG. The system temperature was maintained at 80°C while stirring. Next, an aqueous solution of 360 mg of disuccinic acid peroxide in 20 g of water and an aqueous solution of 10 mg of ammonium persulfate in 20 g of water were added with TFE to initiate the polymerization reaction. As the polymerization reaction progressed, the system pressure decreased, but additional TFE was added to maintain the system temperature at 80°C and the system pressure at 0.78 MPaG. When 1530 g of TFE had been consumed (90% conversion) since the start of polymerization, 4.2 g of CTFE was added with TFE. The polymerization continued, and when the amount of TFE polymerization reached approximately 1700 g from the start of polymerization, the stirring and TFE supply were stopped, and the gas in the system was immediately released to return to normal pressure, thereby terminating the polymerization reaction. The aqueous dispersion was removed and cooled, and the paraffin wax was separated to obtain an aqueous PTFE dispersion. The average primary particle size of the resulting aqueous PTFE dispersion was 241 nm, and the solids concentration was 32.0 mass%.

[0183] The resulting aqueous PTFE dispersion was diluted to a solids concentration of 13% by mass, and the mixture was vigorously stirred in a vessel equipped with a stirrer to solidify, and then the water was separated by filtration to obtain a wet PTFE powder. The resulting wet PTFE powder was dried at 145°C for 18 hours to obtain PTFE-2. The CTFE content of the obtained PTFE-2 was 0.23 mass %, and the SSG was 2.170.

[0184] (Preparation Example 1) 0.273 g of lauric acid was added to 16 g of deionized water, and 2.77 g of a 2.8% aqueous solution of ammonia was gradually added thereto while stirring, to obtain aqueous solution C. 10 g of lauric acid was added to 100 g of deionized water, and 25 g of a 10% aqueous solution of ammonia was gradually added while stirring to obtain aqueous solution D. The pH at this time was 9.6.

[0185] (Production Example 3) A 3-liter stainless steel autoclave equipped with a stirring blade and a temperature-controlling jacket was charged with 1748 g of deionized water, 90 g of paraffin wax, the aqueous solution C obtained in Preparation Example 1, and 0.5 g of ammonium oxalate. The pH of the aqueous dispersion was 9.0. The autoclave was sealed and heated to 70°C, while the system was purged with nitrogen to remove oxygen. While stirring, the system temperature was maintained at 70°C, and 2.0 g of HFP was added. The pressure was then increased to 2.70 MPaG with TFE. Continuously charging a 0.5% by mass aqueous potassium permanganate solution as a polymerization initiator into the autoclave began, at which point the pressure decreased and the reaction began. TFE was charged to maintain a constant system pressure of 2.70 MPaG. When 80 g of TFE had been charged, stirring was stopped, and the system was depressurized until atmospheric pressure was reached. The autoclave was immediately filled with TFE, the system pressure was adjusted to 2.70 MPaG, stirring was resumed, and the reaction was continued. At the same time, the continuous addition of Aqueous Solution D obtained in Preparation Example 1 to the autoclave was started. When 680 g of TFE had been added, stirring was stopped, and the system was depressurized to atmospheric pressure. By the end of the reaction, 56.0 g of an aqueous potassium permanganate solution and 26.2 g of Aqueous Solution D had been added. The aqueous dispersion was removed and cooled, and the paraffin wax was separated to obtain an aqueous PTFE dispersion. The resulting aqueous PTFE dispersion had a pH of 8.8, a solids concentration of 27.1 mass%, and a primary particle size of 220 nm.

[0186] The resulting PTFE aqueous dispersion was diluted with deionized water to a solids concentration of 13% by mass, and the mixture was vigorously stirred in a container equipped with a stirrer to solidify, and then filtered to separate the water, yielding a wet powder. The obtained wet powder was dried at 240°C for 18 hours to obtain PTFE-3. The resulting PTFE-3 had an HFP content of 0.002% by mass and a standard specific gravity of 2.170.

[0187] Preparation of mixture sheets and evaluation of the mixture sheets and battery evaluation of the examples and comparative examples were carried out according to the following procedures. (Preparation of positive electrode mixture sheet) The active material and the conductive additive were weighed, put into a V-type mixer, and mixed at 37 rpm for 10 minutes to obtain a mixture of the active material and the conductive additive. Next, the mixture and a compound (any of Compounds 1-1 to 1-7, 2-1, and 2-2) were added to a high-speed fluid mixer and processed at 200 rpm for 1 minute to disperse the mixture. Thereafter, a weighed binder (fibrillar resin: PTFE powder) was added to the mixture, and it was thoroughly cooled in a thermostatic bath at 5°C. The mixture consisting of the active material, conductive additive, binder, and compound was added to a high-speed fluid mixer, and the mixture was homogenized by processing at 1500 rpm for 3 minutes. Thereafter, the mixture was sufficiently heated in a thermostatic bath at 80°C, and then treated in a high-speed fluid mixer at 2500 rpm for 8 minutes to promote fibrillation, thereby obtaining an electrode mixture. The electrode mixture was fed into a rolling mill in which metal rolls were arranged in parallel and could rotate at different peripheral speeds, to obtain an electrode mixture sheet (temperature: 60°C, left roll rotation speed: 1 m / min, right roll rotation speed: 0.8 m / min). The obtained mixture sheet was again put into the rolling mill and rolled to obtain an electrode mixture sheet with higher sheet strength. The electrode mixture sheet was then placed in a roll press and the gap was adjusted to a final thickness of 80 μm. Table 1 shows the material types and composition ratios (mass ratios). Furthermore, all of the obtained electrode mixture sheets were self-supporting films.

[0188] (Measurement of the strength of the positive electrode mixture sheet) The positive electrode mixture sheet was cut out to prepare 4 mm wide strip-shaped test pieces. Measurements were performed using a tensile tester (Shimadzu Corporation AGS-100NX) at a rate of 100 mm / min. The chuck distance was 40 mm. Displacement was applied until fracture, and the maximum stress measured was used as the strength of each sample. Comparative Example A-1 was used in Table 2, Comparative Example B-1 in Table 3, and Comparative Example C-1 in Table 4, all of which were set to 100 for comparison. The samples were ranked from A to E, with the highest tensile strength and the best electrode strength. A: 150 or more B:130~149 C:110~129 D:95~109 E: Under 95

[0189] (Preparation of positive electrode) The positive electrode mixture sheet was adhered to a 20 μm aluminum foil in the following manner. The adhesive used was a slurry of polyvinylidene fluoride (PVDF) dissolved in N-methylpyrrolidone (NMP) and carbon black dispersed in a ratio of 80:20. The adhesive was applied to aluminum foil and dried on a hot plate at 120°C for 15 minutes to form a current collector with an adhesive layer. Thereafter, the positive electrode mixture sheet was placed on a current collector with an adhesive layer, and the positive electrode mixture sheet and the current collector were bonded together using a roll press heated to 100°C. The sheet was then cut to the desired size and tabbed to form a positive electrode.

[0190] (Preparation of negative electrode) To 98 parts by mass of a carbonaceous material (graphite), 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of sodium carboxymethylcellulose: 1% by mass) and 1 part by mass of an aqueous dispersion of styrene-butadiene rubber (concentration of styrene-butadiene rubber: 50% by mass) were added as thickeners and binders, and the mixture was mixed in a disperser to form a slurry. The resulting slurry was applied to a 10 μm thick copper foil, dried, rolled in a press, cut to the desired size, and tabbed to form a negative electrode.

[0191] (Preparation of electrolyte) A mixed solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (EC:EMC = 30:70 (volume ratio)) was weighed into a sample bottle as an organic solvent, and 1 mass% each of fluoroethylene carbonate (FEC) and vinylene carbonate (VC) was dissolved therein to prepare a mixed solution. LiPF6 salt was mixed with this mixed solution at 23°C so that the concentration in the electrolyte solution became 1.1 mol / L, to obtain a nonaqueous electrolyte solution.

[0192] (Fabrication of aluminum laminated cells) The positive electrode was placed opposite the negative electrode via a 20 μm-thick microporous polyethylene film (separator), and the nonaqueous electrolyte solution obtained above was poured into the battery. After the nonaqueous electrolyte solution had sufficiently permeated the separator and other components, the battery was sealed, pre-charged, and aged to prepare a lithium ion secondary battery.

[0193] <Battery evaluation> The lithium ion secondary battery produced above was charged at a constant current and constant voltage (hereinafter referred to as CC / CV charging) (0.1C cut) at 45°C to 4.25V at a current equivalent to 0.33C, and then discharged to 3V at a constant current of 0.33C. This was counted as one cycle, and the initial discharge capacity was calculated from the discharge capacity at the third cycle. The obtained initial discharge capacities (initial capacities) were ranked by relative evaluation, with Comparative Example A-1 in Table 2, Comparative Example B-1 in Table 3, and Comparative Example C-1 in Table 4 being set at 100 for comparison. ◎: 110 or more ○:105~109 △:95~104 ×: Less than 95 Next, the batteries for which the initial discharge capacity evaluation had been completed were again CC / CV charged (0.1C cut) to 4.3 V at 45°C, and the battery volume was determined by the Archimedes method. After determining the battery volume, the batteries were stored at high temperature at 60°C for 30 days. After high-temperature storage, the batteries were sufficiently cooled and then the volume of the batteries was determined at 25°C. The amount of gas generated was calculated from the difference in volume between the batteries before and after the storage test. The gas generation amounts obtained were ranked by relative evaluation, with Comparative Example A-1 in Table 2, Comparative Example B-1 in Table 3, and Comparative Example C-1 in Table 4 being set at 100 for comparison. ◎: Less than 80 ○:80~89 △:90~109 ×: 110 or more

[0194] [Table 1]

[0195] [Table 2]

[0196] [Table 3]

[0197] [Table 4]

Claims

1. Fluoropolyether, fibrillar resin and electrochemical device material, the electrochemical device material is an electrode active material capable of electrochemically absorbing and desorbing alkali metal ions, The mixture for an electrochemical device, wherein the fibrillar resin is polytetrafluoroethylene.

2. 2. The mixture for electrochemical devices according to claim 1, wherein the fluoropolyether is at least one of the fluoropolyethers represented by the following formulas (1) to (4): (1) R １ -O-Ra １ -Rb １ -O-Ra １ -R １ (2) R ２ -Rb ２ -O-Ra ２ -Rb ２ -R ２ (3) R ３ -Rb ３ -O-Ra ３ -R ３ (4)R ４ -Rb ４ -R ４ (In the formula, Ra １ ~Ra ３ are each independently a polyoxyalkylene group containing 4 to 50 oxyalkylene units and containing no fluorine; Ra １ ~Ra ３ Each oxyalkylene unit is independently —CH ２ CH ２ O- or -CH ２ CH(J)O—, J's are each independently an alkyl group or an aryl group; Rb １ ~Rb ４ are each independently a fluoropolyether group represented by the following formula (5): R １ ~R ３ are each independently a hydrogen atom, a hydroxyl group, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, an aryl group, a carboxylic acid group, or a fluoroalkyl group having 1 to 3 carbon atoms, R ４ are each independently a fluorine atom, a hydrogen atom, a hydroxyl group, an aldehyde group, a carboxylic acid group, an alkyl ester group having 1 to 10 carbon atoms, an amide group which may have a substituent, or an amino group which may have a substituent. (5)-Rf １ -Rf-O-Rf ２ - (wherein, Rf １ and Rf ２ each independently represents an alkylene group having 1 to 16 carbon atoms which may be substituted with a fluorine atom, Rf is a divalent fluoropolyether group.

3. The Ra １ ~Ra ３ and each independently represent a polyoxyalkylene group represented by the following formula (Ra-I): (Ra-I): -(CH ２ CH ２ O)r(CH ２ CH(CH ３ )O)s(CH ２ CH(CH ２ CH ３ )O)t(CH ２ CH(Ph)O)u- (In the formula, r, s, t, and u are each independently an integer of 0 or 1 or more, and r+s+t+u is 4 to 50.)

4. The Ra １ ~Ra ３ 4. The mixture for electrochemical devices according to claim 2, wherein the number average molecular weight of the mixture is 40 to 4,000.

5. 4. The mixture for electrochemical devices according to claim 2, wherein each Rf is independently a fluoropolyether group represented by the following formula (Rf-I): Formula (Rf-I): -(OC ６ F １２ )a-(OC ５ F １０ )b-(OC ４ F ８ )c-(OC ３ Rc ６ )d-(OC ２ F ４ )e-(OCF ２ )f- (In the formula, each Rc independently represents a hydrogen atom, a fluorine atom, or a chlorine atom, a, b, c, d, e, and f each independently represent an integer of 0 to 200; the sum of a, b, c, d, e, and f is greater than or equal to 1; The order of the repeating units assigned with a, b, c, d, e, or f is arbitrary; When all Rc's are hydrogen atoms or chlorine atoms, at least one of a, b, c, e, and f is 1 or more.

6. 4. The mixture for electrochemical devices according to claim 2, wherein each Rf is independently a group represented by the following formula (Rf-II) or the following formula (Rf-I-II): Formula (Rf-II): -(OC ３ F ６ )d-(OC ２ F ４ )e- (In the formula, d is an integer of 1 to 200, and e is 0 or 1.) Formula (Rf-I-II): -(OC ４ F ８ )c-(OC ３ F ６ )d-(OC ２ F ４ )e-(OCF ２ )f- (In the formula, c and d each independently represent an integer of 0 to 30, e and f each independently represent an integer of 1 to 200; the sum of c, d, e, and f is 2 or more; The order of the repeating units marked with c, d, e, or f is arbitrary.

7. The R １ ~R ３ 4. The mixture for an electrochemical device according to claim 2 or 3, wherein each of the groups independently represents a methyl group, an ethyl group, a trifluoromethyl group, or a pentafluoroethyl group.

8. 4. The mixture for electrochemical devices according to claim 1, wherein the fluoropolyether is liquid at any temperature between 25°C and 80°C.

9. 4. The mixture for electrochemical devices according to claim 1, wherein the content of the polyalkylene oxide represented by the following formula (6) is less than 20 mass %: (6)R １Ｂ -(OCHR １Ａ (CH ２ )jCHR ２Ａ )n-OR ２Ｂ (In the formula, R １Ａ and R ２Ａ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, j is 0 or an integer of 1 to 2; R １Ｂ and R ２Ｂ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, n is an integer from 5 to 1000.

10. The mixture for electrochemical devices according to any one of claims 1 to 3, further comprising a conductive assistant.

11. A mixture sheet for electrochemical devices, comprising the mixture for electrochemical devices according to any one of claims 1 to 3.

12. An electrochemical device using the mixture sheet for electrochemical devices according to claim 11.

13. (1) a step of mixing a fluoropolyether, a fibrillar resin, and an electrochemical device material; and step (2) of rolling the mixture for electrochemical devices obtained in step (1) into a sheet shape, The method for producing a mixture sheet for an electrochemical device, wherein the fibrillar resin is polytetrafluoroethylene.

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