Composition for fluoride-ion solid-state battery, and fluoride-ion solid-state battery

Abstract

The purpose of the present disclosure is to provide: a composition for a fluoride-ion solid-state battery capable of improving battery capacity; and a fluoride-ion solid-state battery in which the same is used. The present disclosure is a composition for a fluoride-ion solid-state battery, said composition containing: a fluoride-ion conductive solid electrolyte and / or an active material for a fluoride-ion solid-state battery; and a fluoropolyether compound and / or a silicone compound.

Description

Composition for fluoride ion solid battery and fluoride ion solid battery

[0001] The present disclosure relates to a composition for a fluoride ion solid state battery and a fluoride ion solid state battery.

[0002] With the recent trend toward lighter and smaller electrical appliances, electrochemical devices with high energy density have been developed.

[0003] Fluoride ion batteries, which are one type of electrochemical device, use fluoride ions (F － ) as a charge carrier and characterized by high voltage, and various studies are being conducted on this battery (see, for example, Patent Document 1). However, further improvement in battery capacity is required.

[0004] Japanese Patent Application Laid-Open No. 2023-147251

[0005] An object of the present disclosure is to provide a composition for a fluoride ion solid state battery that can improve battery capacity, and a fluoride ion solid state battery using the same.

[0006] The present disclosure (1) is a composition for a fluoride ion solid battery, which comprises a fluoride ion conductive solid electrolyte and / or an active material for a fluoride ion solid battery, and a fluoropolyether compound and / or a silicone compound.

[0007] The present disclosure (2) is the composition for a fluoride ion solid battery according to the present disclosure (1), which contains the fluoropolyether compound.

[0008] The present disclosure (3) is the composition for a fluoride ion solid battery according to the present disclosure (1) or (2), wherein the fluoropolyether compound is at least one of 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 -R３ (4) R ４ -Rb ４ -R ４ (In the formula, Ra １ ~Ra ３ are each independently a group containing a fluorine-free alkylene unit and / or a fluorine-free oxyalkylene unit, １ ~Ra ３ Each oxyalkylene unit is independently —CH ２ CH ２ O- or -CH ２ CH(J)O—, each J is independently an alkyl group or an aryl group, and Rb １ ~Rb ４ are each independently a fluoropolyether group represented by the following formula (5), 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, or a fluoroalkyl group having 1 to 3 carbon atoms, 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. １ -Rf-O-Rf ２ - (wherein, Rf １ and Rf ２ are each independently an alkylene group having 1 to 16 carbon atoms which may be substituted with a fluorine atom, and Rf is a divalent fluoropolyether group.

[0009] The present disclosure (4) is １ ~Ra ３ are each independently 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-(CH２ CH(Ph)O)u- (wherein r, s, t, and u each independently represent an integer of 0 or 1 or greater, and r+s+t+u is 4 to 50.)

[0010] The present disclosure (5) is １ ~Ra ３ The composition for a fluoride ion solid battery according to the present disclosure (3) or (4), wherein the number average molecular weight of

[0011] The present disclosure (6) is the composition for a fluoride ion solid state battery according to any one of the present disclosures (3) to (5), 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 is independently a hydrogen atom, a fluorine atom, or a chlorine atom; each a, b, c, d, e, and f is independently an integer of 0 to 200; the sum of a, b, c, d, e, and f is 1 or more; the order of the repeating units assigned with a, b, c, d, e, or f is arbitrary; and when all Rc's are hydrogen atoms or chlorine atoms, at least one of a, b, c, e, and f is 1 or more.)

[0012] The present disclosure (7) includes the fluoropolyether compound represented by the formula (4), wherein R ４ are each independently a fluorine atom, １ and Rf ２ are each independently a fluorine-substituted alkylene group having 1 to 3 carbon atoms substituted with a fluorine atom, and Rf is -(OCF(CF ３ )CF ２ )b-, wherein b is an integer of 1 to 200.

[0013] The present disclosure (8) includes the fluoropolyether compound represented by the formula (1), wherein the R １ are each independently an alkyl group having 1 to 3 carbon atoms, １ are each independently a group containing a fluorine-free oxyalkylene unit, １ Each oxyalkylene unit is independently —CH ２ CH ２ O—, and the Rf １ and Rf ２ are each independently an alkylene group having 1 to 3 carbon atoms substituted with a fluorine atom, Rf is a divalent fluoropolyether group, and Rf is -(OC ２ F ４ ) e-(OCF ２ )f-, wherein e is an integer of 5 to 200, and f is an integer of 5 to 200.

[0014] The present disclosure (9) is the composition for a fluoride ion solid battery according to any one of the present disclosures (1) to (8), wherein the content of the fluoropolyether compound is 0.1 to 30 mass %.

[0015] The present disclosure (10) is the composition for a fluoride ion solid battery according to any one of the present disclosures (1) to (9), wherein the content of the fluoropolyether compound is 1 to 10 mass %.

[0016] The present disclosure (11) is a composition for a fluoride ion solid battery according to any one of the present disclosures (1) to (10), which contains a fluoride salt.

[0017] The present disclosure (12) is the composition for a fluoride ion solid battery according to the present disclosure (11), wherein the fluoride salt is CsF.

[0018] The present disclosure (13) is a composition for a fluoride ion solid state battery according to the present disclosure (11) or (12), which contains an anion acceptor.

[0019] The present disclosure (14) is the composition for a fluoride ion solid state battery according to the present disclosure (13), wherein the anion acceptor is 2,4,6-triphenylboroxine.

[0020] The present disclosure (15) is the composition for a fluoride ion solid state battery according to the present disclosure (13) or (14), wherein the content of the fluoropolyether compound is 1 to 10 mass %, the fluoride salt is CsF, and the anion acceptor is 2,4,6-triphenylboroxine.

[0021] The present disclosure (16) is a fluoride ion solid state battery comprising the composition for a fluoride ion solid state battery according to any one of the present disclosures (1) to (15).

[0022] According to the present disclosure, it is possible to provide a composition for a fluoride ion solid state battery that can improve battery capacity, and a fluoride ion solid state battery using the same.

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

[0024] <Composition for Fluoride Ion Solid State Battery> The present disclosure relates to a composition for a fluoride ion solid state battery, comprising a fluoride ion conductive solid electrolyte and / or an active material for a fluoride ion solid state battery, and a fluoropolyether compound and / or a silicone compound.

[0025] By using the composition of the present disclosure in the solid electrolyte layer or electrode layer of a fluoride ion solid state battery, the battery capacity of the fluoride ion solid state battery can be improved. This effect is thought to be brought about by the fluoropolyether compound and / or silicone compound in the composition functioning as a lubricant, thereby improving the packing density of the fluoride ion conductive solid electrolyte and / or the active material for a fluoride ion solid state battery and reducing the grain boundary resistance. In particular, the composition for a fluoride ion solid state battery of the present disclosure preferably contains the fluoride ion conductive solid electrolyte and / or the active material for a fluoride ion solid state battery and the fluoropolyether compound.

[0026] The fluoride ion conductive solid electrolyte is not particularly limited as long as it can be used in a fluoride ion solid battery, and examples thereof include fluorides of lanthanoid elements such as La and Ce, fluorides of alkali metal elements such as Li, Na, K, Rb, and Cs, fluorides of alkaline earth elements such as Ca, Sr, and Ba, and fluorides containing a plurality of lanthanoid elements, alkali metal elements, and alkaline earth elements. （１－ｘ） Ba ｘ F （３－ｘ） (0≦x≦2), Pb （２－ｘ） Sn ｘ F ４ (0≦x≦2), Ca （２－ｘ） Ba ｘ F ４ (0≦x≦2), Ce （１－ｘ） Ba ｘ F （３－ｘ） (0≦x≦2), Ce （１－ｘ） Sr ｘ F （３－ｘ） (0≦x≦2), etc. The x may be greater than 0, 0.3 or greater, 0.5 or greater, or 0.9 or greater. The x may be smaller than 1, 0.9 or less, 0.5 or less, or 0.3 or less.

[0027] The fluoride ion solid battery active material may be either a positive electrode active material or a negative electrode active material.

[0028] When the fluoride ion solid battery active material is a positive electrode active material, specific examples include Au, Pt, S, Ag, Fe, Co, Ni, Cu, Cr, Mo, W, V, Sb, Bi, Sn, In, Ce, and Pb. These may be used alone or in combination of two or more. Furthermore, the positive electrode active material may be an alloy of two or more metals, or a fluoride of these metals. The positive electrode active material may be, for example, a foil, a compact, or one formed by a vapor deposition method.

[0029] When the active material for a fluoride ion solid battery is a negative electrode active material, specific examples include those that occlude and release carrier ions, and may be those that adsorb and desorb carrier ions like a capacitor, or those that insert and desorb carrier ions like an ion secondary battery. Specific examples include precious metals such as Pt, Au, and Ag; lithium metal; carbonaceous materials such as 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 alloys; Li ４ Ti ５ O １２ These may be used alone or in combination of two or more.

[0030] When the composition of the present disclosure is used in a solid electrolyte layer, the content of the fluoride ion-conducting solid electrolyte is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and is preferably 99.9% by mass or less, more preferably 99% by mass or less, even more preferably 98% by mass or less.

[0031] When the composition of the present disclosure is used in an electrode layer, the content of the fluoride ion conductive solid electrolyte is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less. In this case, the content of the fluoride ion solid battery active material is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less.

[0032] As the fluoropolyether compound, at least one of the compounds represented by the following formulas (1) to (4) can be suitably used. １ ~Rb ４ Furthermore, the compounds of the following formulas (1) to (3) exhibit good lubricity.１ ~Ra ３ The portion (1) R can provide ionic conductivity and improve the solubility of fluoride salts. 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 group containing a fluorine-free alkylene unit and / or a fluorine-free oxyalkylene unit, １ ~Ra ３ Each oxyalkylene unit is independently —CH ２ CH ２ O- or -CH ２ CH(J)O—, each J is independently an alkyl group or an aryl group, and Rb １ ~Rb ４ are each independently a fluoropolyether group represented by the following formula (5), 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, or a fluoroalkyl group having 1 to 3 carbon atoms, 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. １ -Rf-O-Rf ２ - (wherein, Rf １ and Rf ２are each independently an alkylene group having 1 to 16 carbon atoms which may be substituted with a fluorine atom, and Rf is a divalent fluoropolyether group.

[0033] Ra １ ~Ra ３ The alkylene unit may be linear or branched, but is preferably linear, and preferably has 1 to 3 carbon atoms.

[0034] Ra １ ~Ra ３ The oxyalkylene unit is -CH ２ In the case of CH(J)O-, the alkyl group for J may be linear or branched, but is preferably linear. The alkyl group for 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.

[0035] Ra １ ~Ra ３ In the formula (I), the total number of fluorine-free alkylene units and fluorine-free oxyalkylene units is preferably 4 to 50.

[0036] Ra １ ~Ra ３ Each of the groups preferably independently contains at least an oxyalkylene unit, and is more preferably 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- (wherein r, s, t, and u each independently represent an integer of 0 or 1 or greater, and r+s+t+u is 4 to 50.)

[0037] In the above formula (Ra-I), r is preferably 1 or more, more preferably 2 or more, and 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 preferably 20 or less, more preferably 10 or less.

[0038] Ra １ ~Ra ３ The number average molecular weight of the polymer is preferably 40 or more, more preferably 100 or more, and is preferably 4000 or less, more preferably 1000 or less, particularly preferably 500 or less. １ ~Ra ３ The number average molecular weight of １ This is a value measured by H-NMR.

[0039] Rb １ ~Rb ４ In the formula (5), Rf １ and Rf ２ The alkylene group of Rf may be linear or branched, but is preferably linear. １ and Rf ２ The alkylene group of Rf is preferably a fluorine-substituted alkylene group substituted with a fluorine atom. １ and Rf ２ The alkylene group preferably has 1 to 3 carbon atoms.

[0040] Rb １ ~Rb ４ In the above formula (5), Rf may have a ring structure.

[0041] Rb １ ~Rb ４ In the formula (5), Rf is preferably 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-(OC３ Rc ６ ) d-(OC ２ F ４ ) e-(OCF ２ )f- (In the formula, each Rc is independently a hydrogen atom, a fluorine atom, or a chlorine atom; each a, b, c, d, e, and f is independently an integer of 0 to 200; the sum of a, b, c, d, e, and f is 1 or more; the order of the repeating units assigned with a, b, c, d, e, or f is arbitrary; and when all Rc's are hydrogen atoms or chlorine atoms, at least one of a, b, c, e, and f is 1 or more.)

[0042] Rc is preferably a hydrogen atom or a fluorine atom, more preferably a fluorine atom, That is, Rf in formula (5) is preferably a perfluoropolyether group.

[0043] Preferably, a, b, c, d, e and f are each independently an integer of 0 to 100.

[0044] 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.

[0045] Each repeating unit to which a, b, c, d, e, or f is assigned may be linear or branched. ６ F １２ )- is, for example, -(OCF ２ CF ２ CF ２ CF ２ CF ２ CF ２ )-,-(OCF(CF ３ )CF ２ CF ２ CF ２ CF ２ ) -, -(OCF ２ CF (CF ３ )CF ２ CF ２ CF ２ ) -, -(OCF ２ CF２ CF (CF ３ )CF ２ CF ２ ) -, -(OCF ２ CF ２ CF ２ CF (CF ３ )CF ２ ) -, -(OCF ２ CF ２ CF ２ CF ２ CF (CF ３ ))-. ５ F １０ )- is, for example, -(OCF ２ CF ２ CF ２ CF ２ CF ２ )-,-(OCF(CF ３ )CF ２ CF ２ CF ２ ) -, -(OCF ２ CF (CF ３ )CF ２ CF ２ ) -, -(OCF ２ CF ２ CF (CF ３ )CF ２ ) -, -(OCF ２ CF ２ CF ２ CF (CF ３ ))-. ４ F ８ )- is, for example, -(OCF ２ CF ２ CF ２ CF ２ )-,-(OCF(CF ３ )CF ２ CF ２ ) -, -(OCF ２ CF (CF ３ )CF ２ ) -, -(OCF ２ CF ２ CF (CF ３ )) -, -(OC(CF ３ ) ２ CF ２ ) -, -(OCF ２C (CF ３ ) ２ )-,-(OCF(CF ３ )CF(CF ３ ))-,-(OCF(C ２ F ５ )CF ２ ) -, -(OCF ２ CF (C ２ F ５ ))-. ３ F ６ )-(that is, in the above formula (Rf-I), when all Rc's are fluorine atoms), can be represented by, for example, -(OCF ２ CF ２ CF ２ )-,-(OCF(CF ３ )CF ２ ) -, -(OCF ２ CF (CF ３ ))-. ２ F ４ )- is, for example, -(OCF ２ CF ２ )-,-(OCF(CF ３ ))-.

[0046] Rf may be a group represented by any one of the following formulae (Rf-II) to (Rf-IV): Formula (Rf-II): -(OC ３ F ６ ) d-(OC ２ F ４ )e- (wherein 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- (wherein 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, and the order of the repeating units assigned with c, d, e or f is arbitrary.) Formula (Rf-I-III): -(R ２０ -R ２１ ) g- (wherein, R２０ is OCF ２ or O.C. ２ F ４ and R ２１ is O.C. ２ F ４ , O.C. ３ F ６ , O.C. ４ F ８ , O.C. ５ F １０ and O.C. ６ F １２ or a combination of two or three groups selected from these groups, and g is an integer of 2 to 100.) Formula (Rf-I-IV): -(OC ６ F １２ ) a-(OC ５ F １０ ) b-(OC ４ F ８ ) c-(OC ３ F ６ ) d-(OC ２ F ４ ) e-(OCF ２ )f- (wherein e is an integer of 1 to 200, a, b, c, d and f each independently are an integer of 0 to 200, and the order of the repeating units to which a, b, c, d, e or f is assigned is arbitrary.) Formula (Rf-IV): -(OC ６ F １２ ) a-(OC ５ F １０ ) b-(OC ４ F ８ ) c-(OC ３ F ６ ) d-(OC ２ F ４ ) e-(OCF ２ )f- (wherein f is an integer of 1 to 200, a, b, c, d, and e each independently are an integer of 0 to 200, and the order of the repeating units assigned a, b, c, d, e, or f is arbitrary.)

[0047] In the above formula (Rf-II), d may be preferably 5 to 200, more preferably 10 to 100, and even more preferably 10 to 30. The above formula (Rf-II) is preferably -(OCF ２ CF２ CF ２ ) d- or -(OCF(CF ３ )CF ２ ) d- is a group represented by the formula:

[0048] 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 -(OCF ２ CF ２ CF ２ CF ２ )c-(OCF ２ CF ２ CF ２ ) d-(OCF ２ CF ２ ) e-(OCF ２ )f-, or a group represented by -(OC ２ F ４ ) e-(OCF ２ )f-, and more preferably, -(OC ２ F ４ ) e-(OCF ２ )f- is a group represented by the formula:

[0049] In the above formula (Rf-I-III), R ２０ is preferably OC ２ F ４ and R ２１ is preferably OC ２ F ４ , O.C. ３ F ６ and O.C. ４ F ８ or a combination of two or three groups independently selected from these groups, more preferably OC ３ F ６ and O.C. ４ F ８ is a group selected from ２ F ４ , O.C. ３ F ６ and O.C. ４ F ８Examples of the combination of two or three groups independently selected from the group consisting of, but not limited to, -OC ２ F ４ O.C. ３ F ６ -, -OC ２ F ４ O.C. ４ F ８ -, -OC ３ F ６ O.C. ２ F ４ -, -OC ３ F ６ O.C. ３ F ６ -, -OC ３ F ６ O.C. ４ F ８ -, -OC4F8OC ４ F ８ -, -OC ４ F ８ O.C. ３ F ６ -, -OC ４ F ８ O.C. ２ F ４ -, -OC ２ F ４ OC2F4OC ３ F ６ -, -OC ２ F ４ O.C. ２ F ４ O.C. ４ F ８ -, -OC ２ F ４ O.C. ３ F ６ OC2F4-, -OC ２ F ４ O.C. ３ F ６ O.C. ３ F ６ -, -OC ２ F ４ O.C. ４ F ８ O.C. ２ F ４ -, -OC ３ F ６ O.C. ２ F ４ O.C. ２ F ４-, -OC ３ F ６ O.C. ２ F ４ O.C. ３ F ６ -, -OC ３ F ６ OC3F6OC ２ F ４ - and -OC ４ F ８ O.C. ２ F ４ O.C. ２ F ４ 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), OC ２ F ４ , O.C. ３ F ６ , O.C. ４ F ８ , O.C. ５ F １０ , and O.C. ６ F 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 —(OC ２ F ４ -OC ３ F ６ ) g- or -(OC ２ F ４ -OC ４ F ８ ) g-.

[0050] 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.

[0051] 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.

[0052] In Rf, the ratio of e to f (hereinafter referred to as the "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 increased. 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.

[0053] Rf is represented by the following formula (Rf-I-VI): -(OCF ２ CF ２ CF ２ )a-(OCF(CF ３ )CF ２ ) b-(OCF ２ CF(CF3))c-(OCF ２ CF ２ )d-(OCF(CF ３ ))e-(OCF ２ )f- (wherein 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 1 or more, and the order of the repeating units assigned with a, b, c, d, e, or f is arbitrary).

[0054] Rf is represented by the following formula (Rf-I-VII): -(OCF ２ CF ２ )d-(OCF(CF ３ ))e-(OCF ２ )f- (wherein d, e, and f each independently represent an integer of 0 to 200, the sum of d, e, and f is 1 or more, and the order of the repeating units to which d, e, or f is added is arbitrary.) When Rf is this group, it is thought that an increase in the number of ether bonds facilitates coordination of salt cations, thereby improving salt solubility.

[0055] In Rf, the ratio of d to f (hereinafter referred to as the "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 setting the d / f ratio to 4 or less, lubricity and chemical stability are further improved. The smaller the d / f ratio, the more improved the lubricity. On the other hand, by setting the d / f ratio to 0.5 or more, the stability of the compound can be further increased. The larger the d / f ratio, the more improved the stability of the fluoropolyether structure. In this case, the d / f ratio is preferably 0.8 or more.

[0056] Each Rf is preferably 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). Each Rf is also preferably a group represented by the above formula (Rf-I-VI). In this case, it is more preferable that b is an integer of 1 to 200, and a, c, d, e, and f are 0. That is, Rf is -(OCF(CF ３ )CF ２ ) b-, where b is preferably an integer of 1 to 200.

[0057] 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, more preferably 2,000 to 10,000, and even more preferably 2,000 to 5,000. １９ This is a value measured by F-NMR.

[0058] R １ ~R ３ The alkyl group and fluoroalkyl group of R may be linear or branched, but is preferably linear. 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.

[0059] 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.

[0060] R ４ The alkyl ester group may be linear or branched.

[0061] 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.

[0062] 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. ４ is a fluorine atom, R ４ -Rb ４ and Rb ４ -R ４ , that is, R ４ -Rf １ and Rf ２ -R ４ are each independently -CF ３ , -CF ２ CF ３ , and -CF ２ CF ２ CF ３ It may be a group selected from the group consisting of:

[0063] The fluoropolyether compound is particularly preferably the compound represented by formula (1) or (4) because of its good ionic conductivity.

[0064] The silicone compound is not particularly limited as long as it has a siloxane bond, but it is preferable that it has a polyoxyalkylene chain together with the siloxane bond. Examples of the constituent units of the polyoxyalkylene chain include oxyethylene, oxypropylene, oxybutylene, etc. The proportions thereof are not particularly limited.

[0065] The silicone compound preferably has a kinematic viscosity at 25°C of 5 cSt to 60,000 cSt. If the kinematic viscosity is too low, the silicone compound may flow out during pressure molding, and if it is too high, the compound may not function sufficiently as a lubricant. The kinematic viscosity is preferably 10 cSt or more, more preferably 100 cSt or more, and is preferably 20,000 cSt or less, more preferably 10,000 cSt or less. In this specification, the kinematic viscosity is a value determined using an Ubbelohde viscometer at 25°C in accordance with ASTM D445-46T.

[0066] The higher the affinity of the silicone compound with water molecules, i.e., the greater the saturated water content, the higher its polarity tends to be. Furthermore, when the polarity of the silicone compound is high, electrochemical properties such as discharge capacity tend not to deteriorate. This is thought to be due to the ability of ions to move within the silicone compound. From this perspective, the silicone compound preferably has a saturated water content of more than 30 ppm at 25°C, more preferably 50 ppm or more, and even more preferably 100 ppm or more. There is no particular upper limit, but when the silicone compound does not have a polyoxyalkylene chain, it is usually 1000 ppm or less. In this specification, the saturated water content is measured by the following method. A mixture is obtained by adding water in an amount five times the volume of the silicone compound, stirring the mixture, and allowing it to stand at 25°C for 24 hours. The mixture is then centrifuged to separate it into an aqueous phase and a silicone compound-rich phase, and the concentrated phase is measured using Karl Fischer titration. The moisture content was measured using a Karl Fischer moisture meter (MKC-610, manufactured by Kyoto Electronics Manufacturing Co., Ltd.) and Aquamicron AX (manufactured by Mitsubishi Chemical Corporation) as the Karl Fischer reagent, and the sample amount was 1 g. When the silicone compound has a polyalkylene chain, it is miscible with water, and therefore the saturated moisture content is considered to be infinite.

[0067] If the silicone compound has a high water content, the battery material may be deteriorated by the water, and the battery characteristics may be impaired. Therefore, it is preferable to use the silicone compound after dehydration treatment. The dehydration treatment is not particularly limited, but for example, the silicone compound is placed in an evaporator and 1.0 × 10 ２ An example of a method is to dry the silicone compound for 3 to 6 hours while heating in an oil bath or the like at 80 to 150°C at 100 Pa. The moisture content of the silicone compound after drying is preferably 150 ppm or less, and more preferably 100 ppm or less. There is no particular lower limit, and the lower limit may be 0 ppm, but it is usually 10 ppm or more. In this specification, the moisture content is measured using Karl Fischer titration.

[0068] When the composition of the present disclosure is used in a solid electrolyte layer or an electrode layer of a fluoride ion solid state battery, the battery may be manufactured through a process involving heating, such as hot molding. However, if the silicone compound volatilizes due to heating, sufficient improvement effects may not be achieved. Furthermore, if the silicone compound volatilizes, bubbles may form in the solid electrolyte layer or the electrode layer, potentially resulting in a defective product. Therefore, it is preferable that the silicone compound is less likely to volatilize. From this perspective, the silicone compound preferably exhibits a mass loss rate of 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, when heated at 150°C for 24 hours. The lower limit is not particularly limited and may be 0% by mass, but is typically 0.5% by mass or more. In this specification, the mass loss rate is measured by the following method. 5 g of the silicone compound is weighed into an aluminum cup (diameter 50 mm, height 12 mm), and the mass is measured before and after heating in a hot air circulation oven at 150°C for 24 hours. The mass loss rate is calculated according to the following formula. A sample is taken three times, and the values ​​are calculated for each, and the average value is calculated and used. Mass reduction rate (mass %) = [(mass (g) of silicone compound before heating) - (mass (g) of silicone compound after heating)] / (mass (g) of silicone compound before heating) x 100

[0069] The fluoropolyether compound and the silicone compound are preferably liquid at any temperature between 25° C. and 80° C. because they have good ionic conductivity, etc. Examples of a form "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. Normally, there is no form that is liquid at low temperatures and solid at high temperatures, and therefore this is not included in the form "liquid at any temperature between 25° C. and 80° C.."

[0070] The composition of the present disclosure may contain either the fluoropolyether compound or the silicone compound, or may contain both, but preferably contains the fluoropolyether compound.

[0071] In the composition of the present disclosure, the content of the fluoropolyether compound is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less.

[0072] In the composition of the present disclosure, the content of the silicone compound is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less.

[0073] In the composition of the present disclosure, the total content of the fluoropolyether compound and the silicone compound is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0074] The composition of the present disclosure preferably contains a fluoride salt, which is believed to dissolve in the fluoropolyether compound and the silicone compound, thereby improving ionic conductivity.

[0075] The fluoride salt is not particularly limited as long as it generates fluoride ions, and may be an organic fluoride salt or an inorganic fluoride salt. The fluoride salt may also be an ionic liquid. More specifically, ammonium fluoride, metal fluorides, etc. may be used. These may be used alone or in combination of two or more. Ammonium fluoride is preferred because of its good solubility.

[0076] Specific examples of the metal fluorides include alkali or alkaline earth fluorides (e.g., LiF, NaF, KF, CsF, MgF ２ , BaF ２ ), transition metal fluorides (e.g., VF ４ , FeF ３ , MoF ６ , PdF ２ , AgF), main group metal fluorides (e.g., AlF３ , PbF ４ , BiF ３ ), lanthanide or actinide fluorides (e.g., LaF ３ , YbF ３ , U.F. ５ ) can be mentioned, and among them, CsF is preferable.

[0077] Examples of the ammonium fluoride include ammonium hydrogen fluoride, alkyl ammonium fluoride, etc. Alkyl ammonium fluoride is preferred because of its good solubility.

[0078] The alkylammonium fluoride is N ＋ -Rx ４ Preferably, Rx has a cation represented by the formula: Each Rx is independently an alkyl group or a fluoroalkyl group, and an alkyl group is preferred. The number of carbon atoms in Rx is, for example, 1 to 10, and may be 5 or less, or 3 or less. The alkyl ammonium fluoride is preferably tetramethylammonium fluoride or tetrabutylammonium fluoride.

[0079] The alkyl group and fluoroalkyl group in the alkylammonium fluoride may be linear or branched, but preferably at least one is branched, and more preferably both branched and linear. The number of carbon atoms in the alkyl group and fluoroalkyl group is preferably 1 or more, and preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. The number of carbon atoms in the linear alkyl group and linear fluoroalkyl group is preferably 1 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. The number of carbon atoms in the branched alkyl group and branched fluoroalkyl group is preferably 1 or more, more preferably 3 or more, and even more preferably 4 or more, and preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

[0080] The alkylammonium fluoride is preferably an alkylammonium fluoride having a branched alkyl group having 5 carbon atoms, more preferably an alkylammonium fluoride having a neopentyl group, and further preferably trimethylneopentylammonium fluoride or dimethyldineopentylammonium fluoride.

[0081] In the composition of the present disclosure, the content of the fluoride salt is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, relative to the total content of the fluoropolyether compound and the silicone compound, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less.

[0082] The composition of the present disclosure preferably contains an anion acceptor together with the fluoride salt. The incorporation of the anion acceptor is believed to increase the amount of the fluoride salt dissolved, improving ionic conductivity. Furthermore, the amount of free fluoride ions in the solution is believed to decrease, improving the stability of cycle characteristics.

[0083] Examples of the anion acceptor include tris(hexafluoroisopropyl)borate, tris(pentafluorophenyl)borane, difluorophenylboroxine, trifluorophenylboroxine, bis(trifluoromethyl)phenylboroxine, trifluoromethylphenylboroxine, 2,4,6-triphenylboroxine, trimethoxyboroxine, fluorobis(2,4,6-trimethylphenyl)borane, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine, N,N-diethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline, and fluoro(trifluoromethyl)phenylboroxine, with 2,4,6-triphenylboroxine being preferred. These may be used alone or in combination of two or more.

[0084] In the composition of the present disclosure, the content of the anion acceptor is preferably 0.5 mol % or more, more preferably 0.7 mol % or more, even more preferably 0.9 mol % or more, and is preferably 2.0 mol % or less, more preferably 1.5 mol % or less, even more preferably 1.2 mol % or less, relative to the total substance amount of the fluoride salt.

[0085] The composition of the present disclosure may contain a binder. The binder is not particularly limited, and examples thereof include resin-based polymers such as polytetrafluoroethylene, 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; EPDM (ethylene propylene glycol dimethyl ether (EPDM)); Examples of suitable polymers include thermoplastic elastomers such as propylene-diene terpolymers, styrene-ethylene-butadiene-styrene copolymers, 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; fluorine-containing polymers such as polyvinylidene fluoride, vinylidene fluoride copolymers, and tetrafluoroethylene-ethylene copolymers; and polymer compositions having ionic conductivity for alkali metal ions (particularly lithium ions). These may be used alone or in any combination and ratio of two or more.

[0086] In the composition of the present disclosure, the content of the binder is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, and is preferably 10% by mass or less, more preferably 7% by mass or less, even more preferably 4% by mass or less.

[0087] In addition to the above-mentioned components, the composition of the present disclosure may further contain materials (such as conductive additives) that are generally used in solid electrolyte layers and electrode layers of solid fluoride ion batteries.

[0088] The conductive additive is not particularly limited, and examples thereof include carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black, and carbon materials such as amorphous carbon such as fullerene and VGCF. These may be used alone or in any combination and ratio of two or more.

[0089] The content of the conductive additive is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1% by mass or more, and is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 15% by mass or less.

[0090] The method for producing the composition of the present disclosure is not particularly limited, and the composition can be produced by mixing the respective materials by a conventional method. When mixing the respective materials, all of the materials may be mixed together. However, if the fluoropolyether compound and / or the silicone compound are liquid, other materials may be mixed and then added dropwise to the resulting mixture, either sequentially or in admixture. Alternatively, after preparing an electrode layer or a solid electrolyte layer using the composition of the present disclosure, the liquid fluoropolyether compound and / or the silicone compound may be added dropwise or impregnated therein.

[0091] Fluoride-Ion Solid-State Battery The present disclosure also relates to a fluoride-ion solid-state battery comprising the composition of the present disclosure.

[0092] The fluoride ion solid state battery of the present disclosure includes at least an electrode layer and a solid electrolyte layer. The composition of the present disclosure may be used in either the electrode layer or the solid electrolyte layer, or in both. Furthermore, when used in the electrode layer, the composition may be used in either the positive electrode layer or the negative electrode layer, or in both.

[0093] The electrode layer and the solid electrolyte layer may be produced by a conventional method. For example, the electrode layer may be produced by preparing a slurry containing an electrode active material and the like, applying the slurry to a substrate such as a current collector, and drying the slurry. The same applies to the solid electrolyte layer.

[0094] Examples of materials for the positive electrode current collector include metal materials such as aluminum, titanium, tantalum, stainless steel, nickel, gold, and other metals or alloys thereof; and carbon materials such as carbon cloth and carbon paper. Of these, metal materials, particularly aluminum, gold, and alloys thereof, are preferred. Examples of materials for the negative electrode current collector include metal materials such as copper, nickel, titanium, tantalum, stainless steel, gold, and other metals or alloys thereof; and carbon materials such as carbon cloth and carbon paper. Of these, metal materials, particularly copper, nickel, gold, and alloys thereof are preferred.

[0095] Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, expanded metal, punched metal, and foam metal in the case of a metal material, and carbon plate, carbon thin film, and carbon cylinder in the case of a carbon material. Of these, metal foil is preferred. The metal foil may be appropriately formed into a mesh shape. 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.

[0096] The thickness of the electrode layer is not particularly limited, but from the viewpoint of high capacity and high output, the thickness of the mixture layer minus the thickness of the current collector is preferably 10 μm or more, more preferably 20 μm or more, and preferably 500 μm or less, more preferably 450 μm or less, as a lower limit for one surface of the current collector. The thickness of the solid electrolyte layer is also not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and preferably 80 μm or less, more preferably 50 μm or less.

[0097] From the viewpoint of high capacity and high output, the density of the positive electrode mixture in the electrode layer is preferably 2.80 g / cm３ 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 ３ 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 ３ The range is as follows:

[0098] The solid state fluoride ion battery of the present disclosure may include a separator between the positive electrode layer and the negative electrode layer. Examples of the separator include porous membranes such as polyethylene and polypropylene; nonwoven fabrics made of resins such as polypropylene; and nonwoven fabrics such as glass fiber nonwoven fabrics.

[0099] The fluoride ion solid state battery of the present disclosure 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, a laminate shape, etc.

[0100] The fluoride ion solid state battery of the present disclosure 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.

[0101] 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.

[0102] Next, the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[0103] Comparative Example 1 An all-solid-state fluoride ion secondary battery was fabricated by the following method. Unless otherwise specified, each step was carried out in a purged glove box DBO-1.5B (manufactured by Miwa Seisakusho) equipped with an argon gas circulation purification device.

[0104] [Powder for solid electrolyte layer (Ce ０．９５ Sr ０．０５ F ２．９５ (First Step) Preparation of CeF ３ powder (Sigma-Aldrich; purity 99.99%), 19.351 g, and SrF ２ 0.649 g of powder (Sigma-Aldrich; purity 99.9%) was weighed and mixed for 5 to 10 minutes using an agate mortar and pestle to obtain CeF ３ -SrF ２ A mixed powder was obtained.

[0105] CeF ３ -SrF ２ The mixed powder and 20 silicon nitride milling balls (manufactured by Fritsch) with a diameter of 10 mm were placed in an 80 cc silicon nitride ball mill pot, a Premium Line PL-7 dedicated container (manufactured by Fritsch), and then sealed.

[0106] The sealed ball mill pot was taken out of the glove box, and then the powder was ground using a ball mill under the following conditions: Rotation speed: 600 rpm, Grinding time: 60 minutes, Number of grinding cycles: 40, Rest time between grinding cycles: 5 minutes, Rotation reverse: ON

[0107] After the ball mill pot was carried into the glove box, CeF ３ -SrF ２ The mixed powder was collected.

[0108] (Second step) CeF ３ -SrF ２ The mixed powder was transferred to an alumina crucible and then fired using a small electric furnace KSL-1100X (manufactured by MTI Co., Ltd.) to obtain Ce. ０．９５ Sr ０．０５ F ２．９５The firing conditions were as follows: Argon gas flow rate: 300 cc / min Temperature increase rate: 184°C / h Maximum temperature reached: 1100°C Holding time at maximum temperature reached: 1 hour Temperature decrease rate: not controlled Cooling method: natural cooling

[0109] From the inside of the alumina crucible, Ce ０．９５ Sr ０．０５ F ２．９５ After collection, the powder was ground for 5 to 10 minutes using an agate mortar and pestle.

[0110] [Powder composition for positive electrode layer (Bi / Ce ０．９５ Sr ０．０５ F ２．９５ Preparation of Bi (Sigma-Aldrich Co.) / AB) ０．９５ Sr ０．０５ F ２．９５ 0.700 g of the powder, 0.05 g of acetylene black (AB) (manufactured by Denki Kagaku Kogyo Co., Ltd.), and 40 g of silicon nitride milling balls (manufactured by Fritsch) having a diameter of 2 mm were placed in a 45 cc silicon nitride ball mill pot, a Premium Line PL-7 dedicated container (manufactured by Fritsch), and then sealed.

[0111] The sealed ball mill pot was taken out of the glove box, and then the powder was ground using a ball mill under the following conditions: Rotation speed: 200 rpm, Grinding time: 15 minutes, Number of grinding cycles: 40, Pause time between grinding cycles: 5 minutes, Reverse rotation: ON

[0112] The contents of the ball mill pot were dried under vacuum and then carried into a glove box, where the powder composition for the positive electrode layer was recovered.

[0113] [Powder composition for negative electrode layer (PbSnF ４ Preparation of PbF ２ (manufactured by Kojundo Chemical Laboratory Co., Ltd.) 6.0 g, and SnF ２ 2.8 g of zirconia powder (manufactured by Kojundo Chemical Laboratory Co., Ltd.) and 45 mL of zirconia grinding balls (manufactured by Fritsch) with a diameter of 10 mm were placed in a 45 cc zirconia ball mill pot, a Premium Line PL-7 dedicated container (manufactured by Fritsch), and then the container was sealed.

[0114] The sealed ball mill pot was taken out of the glove box, and then the powder was ground using a ball mill under the following conditions: Rotation speed: 600 rpm, Grinding time: 180 minutes, Number of grinding treatments: 8, Rest time between grinding treatments: 5 minutes, Rotation reverse: ON

[0115] After the ball mill pot was carried into the glove box, PbF ２ -SnF ２ The mixed powder was collected.

[0116] Further, 0.619 g of AB (manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to the mixed powder, and 45 mL of zirconia grinding balls (manufactured by Fritsch) having a diameter of 10 mm were added to a 45 cc zirconia ball mill pot, a Premium Line PL-7 dedicated container (manufactured by Fritsch), and then the container was sealed.

[0117] The sealed ball mill pot was taken out of the glove box, and then the powder was ground using a ball mill under the following conditions: Rotation speed: 600 rpm, Grinding time: 180 minutes, Number of grinding treatments: 8, Rest time between grinding treatments: 5 minutes, Rotation reverse: ON

[0118] The ball mill pot was carried into a glove box, and then the powder composition for the negative electrode layer was recovered from inside the ball mill pot.

[0119] [Production of all-solid-state fluoride ion secondary battery] A cylindrical pellet-type cell was produced by pressing a 20 μm thick gold foil (manufactured by Nilaco Corporation; purity 99.99%) as a negative electrode current collector, 20 mg of a powder composition for a negative electrode layer, 150 mg of powder for a solid electrolyte layer, 10 mg of powder composition for a positive electrode layer, and a 20 μm thick gold foil (manufactured by Nilaco Corporation; purity 99.99%) as a positive electrode current collector were placed in the 20 μm thick gold foil (manufactured by Nilaco Corporation; purity 99.99%) in this order into a 20 μm thick gold foil pellet press, and the cells were pressed at a pressure of 740 MPa to produce a pellet-type cell.

[0120] [Charge-Discharge Test] A constant current charge-discharge test was carried out on the all-solid-state fluoride ion secondary battery. Specifically, a potentiogalvanostat SI1287 / 1255B (manufactured by Solartron) was used to charge and discharge the battery at a constant current of 10 －２ In a Pa vacuum environment, a constant current charge / discharge test was carried out at temperatures of 40, 80, and 140° C. with a charge / discharge current of 0.12 mA, an upper limit voltage of 0.9 V, and a lower limit voltage of −0.5 V. From this test, the charge capacity and discharge capacity in the first and second cycles were calculated.

[0121] Example 1 Similar to Comparative Example 1, a powder composition for the anode layer, a powder composition for the solid electrolyte layer, and a powder composition for the cathode layer were prepared, and then pressed at a pressure of 740 MPa using a tablet press to produce a compacted cylindrical pellet-type cell. Specifically, a 20 μm-thick gold foil (manufactured by Nilaco Corporation; purity 99.99%) serving as an anode current collector, 20 mg of the powder composition for the anode layer, 150 mg of powder for the solid electrolyte layer, and 10 mg of the powder composition for the cathode layer were placed in the tablet press in this order and pressed at a pressure of 740 MPa. Thereafter, 10 μL of the following perfluoropolyether was dropped from the cathode side, and the mixture was held under a reduced pressure of −50 kPa in the side box of an argon glove box for 3 minutes to promote impregnation with the liquid. This operation was performed three times. Finally, a 20 μm thick gold foil (manufactured by Nilaco Corporation; purity 99.99%) was attached as a positive electrode current collector, and the resulting mixture was placed in a tablet molding machine in this order to prepare a pellet-type cell. The amount of perfluoropolyether contained in the powder composition for the positive electrode layer was 2.1 mass%. [Perfluoropolyether] CF ３ CF ２ CF ２ -(OCF(CF ３ )CF ２ ) n-O-CF ２ CF ３ (n: 25.3, -(OCF(CF ３ )CF ２ ) n-Average molecular weight: 4196, liquid at 25°C)

[0122] Example 2 A pellet-type cell was prepared in the same manner as in Example 1, except that a fluoropolyether containing oxyalkylene units synthesized according to the following procedure was used instead of the perfluoropolyether used in Example 1. (Synthesis of fluoropolyether containing oxyalkylene units) 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 terminal alcohol (Solvay, Fomblin D2, 5.1 mmol) were added to a nitrogen-purged reaction vessel 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 from the dropping funnel over 10 minutes, 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 and stirred for 3 hours. This solution was washed four times with pure water, and 2 g of magnesium sulfate was added to the separated organic layer, followed by drying. After removing the magnesium sulfate by filtration, the volatile matter was distilled off from the treated solution, which was then further dried at 100°C for 3 hours to obtain the following fluoropolyethers containing oxyalkylene units. [Fluoropolyethers containing oxyalkylene units] CH ３ O (CH ２ CH ２ O) x 1CH ２ CF ２ (OCF ２ CF ２ ) y(OCF ２ ) zOCF ２ CH ２ O (CH ２ CH ２ O) x 2CH ３ (x1:4, y: average 12.3, z: average 10.2, x2:4, (CH ２ CH ２ Number average molecular weight of (CH ２ CH ２ Number average molecular weight of O) x2: 176)

[0123] Example 3 A pellet-type cell was produced in the same manner as in Example 1, except that a composition prepared by the following procedure was used instead of the perfluoropolyether used in Example 1. (Preparation of fluoropolyether containing oxyalkylene units / salt / anion acceptor composition) A composition was prepared by adding cesium fluoride (CsF) (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) to the fluoropolyether containing oxyalkylene units used in Example 2 so that the concentration was 1 mass %, and further adding 2,4,6-triphenylboroxine (manufactured by Tokyo Chemical Industry Co., Ltd.) in an amount equimolar to the added cesium fluoride.

[0124] Evaluation Results The results of the charge / discharge test are shown in Table 1 below.

[0125] From Table 1, it can be seen that the battery capacity increased in the examples in which perfluoropolyether was added.

Claims

1. A composition for a fluoride ion solid battery, comprising a fluoride ion conductive solid electrolyte and / or an active material for a fluoride ion solid battery, and a fluoropolyether compound and / or a silicone compound.

2. The composition for a fluoride ion solid battery according to claim 1, which contains the fluoropolyether compound.

3. The composition for a fluoride ion solid battery according to claim 1 or 2, wherein the fluoropolyether compound is at least one of 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 group containing a fluorine-free alkylene unit and / or a fluorine-free oxyalkylene unit, １ ~Ra ３ Each oxyalkylene unit is independently —CH ２ CH ２ O- or -CH ２ CH(J)O—, each J is independently an alkyl group or an aryl group, and Rb １ ~Rb ４ are each independently a fluoropolyether group represented by the following formula (5), 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, or a fluoroalkyl group having 1 to 3 carbon atoms, 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. １ -Rf-O-Rf ２ - (wherein, Rf １ and Rf ２ are each independently an alkylene group having 1 to 16 carbon atoms which may be substituted with a fluorine atom, and Rf is a divalent fluoropolyether group.

4. The above Ra １ ~Ra ３ are each independently a polyoxyalkylene group represented by the following formula (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- (wherein r, s, t, and u each independently represent an integer of 0 or 1 or greater, and r+s+t+u is 4 to 50.) 5. The above Ra １ ~Ra ３ The composition for a fluoride ion solid battery according to claim 3 or 4, wherein the number average molecular weight of the compound is 40 to 4,000.

6. The composition for a fluoride ion solid battery according to any one of claims 3 to 5, 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 is independently a hydrogen atom, a fluorine atom, or a chlorine atom; each a, b, c, d, e, and f is independently an integer of 0 to 200; the sum of a, b, c, d, e, and f is 1 or more; the order of the repeating units assigned with a, b, c, d, e, or f is arbitrary; and when all Rc's are hydrogen atoms or chlorine atoms, at least one of a, b, c, e, and f is 1 or more.) 7. The fluoropolyether compound represented by the formula (4) is contained, and the R ４ are each independently a fluorine atom, １ and Rf ２ are each independently a fluorine-substituted alkylene group having 1 to 3 carbon atoms substituted with a fluorine atom, and Rf is -(OCF(CF ３ )CF ２ 7. The composition for a fluoride ion solid battery according to claim 3, wherein the fluoride ion solid battery composition is a group represented by: )b-; and b is an integer of 1 to 200.

8. The fluoropolyether compound represented by the formula (1) is contained, and the R １ are each independently an alkyl group having 1 to 3 carbon atoms, １ are each independently a group containing a fluorine-free oxyalkylene unit, １ Each oxyalkylene unit is independently —CH ２ CH ２ O—, and the Rf １ and Rf ２ are each independently an alkylene group having 1 to 3 carbon atoms substituted with a fluorine atom, Rf is a divalent fluoropolyether group, and Rf is -(OC ２ F ４ ) e-(OCF ２ )f-, wherein e is an integer of 5 to 200, and f is an integer of 5 to 200. The composition for a fluoride ion solid battery according to any one of claims 3 to 6.

9. The composition for a fluoride ion solid battery according to any one of claims 1 to 8, wherein the content of the fluoropolyether compound is 0.1 to 30 mass %.

10. The composition for a fluoride ion solid battery according to any one of claims 1 to 9, wherein the content of the fluoropolyether compound is 1 to 10 mass %.

11. The composition for a fluoride ion solid battery according to any one of claims 1 to 10, which contains a fluoride salt.

12. The composition for a fluoride ion solid battery according to claim 11, wherein the fluoride salt is CsF.

13. The composition for a fluoride ion solid battery according to claim 11 or 12, which contains an anion acceptor.

14. The composition for a fluoride ion solid battery according to claim 13, wherein the anion acceptor is 2,4,6-triphenylboroxine.

15. The composition for a fluoride ion solid battery according to claim 13 or 14, wherein the content of the fluoropolyether compound is 1 to 10 mass %, the fluoride salt is CsF, and the anion acceptor is 2,4,6-triphenylboroxine.

16. A fluoride ion solid state battery comprising the composition for a fluoride ion solid state battery according to any one of claims 1 to 15.

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