Additive for non-aqueous electrolyte solution, non-aqueous electrolyte solution, and electricity storage device

Abstract

Disclosed is an additive for a non-aqueous electrolyte solution, which contains a cyclic sulfone compound represented by formula (1). X1 represents a sulfonyl group or a carbonyl group, and Z represents a monovalent group represented by formula (21), (22), (23) or (24). # imgabs0 #

Description

Technical Field

[0001] The present invention relates to an additive for non-aqueous electrolyte, non-aqueous electrolyte and power storage device. Background Art

[0002] The battery capacity of non-aqueous electrolyte secondary batteries tends to decrease with repeated charge and discharge. In order to suppress the decrease in battery capacity with repeated charge and discharge, various additives are sometimes added to the non-aqueous electrolyte (for example, Patent Documents 1 to 6). It is known that some additives undergo electrochemical decomposition on the electrode surface during initial charge and discharge, forming a film called solid electrolyte interface (SEI) on the electrode surface. It is believed that SEI inhibits the decomposition of solvent molecules on the electrode surface, thereby inhibiting the consumption of electricity with the decomposition of solvent molecules. That is, the formation of a good SEI can help suppress the degradation of power storage devices such as non-aqueous electrolyte secondary batteries.

[0003] Previous technical literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 63-102173

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 5-74486

[0007] Patent Document 3: Japanese Patent Application Laid-Open No. 2004-281368

[0008] Patent Document 4: Japanese Patent Application Laid-Open No. 2015-138597

[0009] Patent Document 5: Japanese Patent Application Laid-Open No. 2002-352852

[0010] Patent Document 6: International Publication No. 2019 / 117101 Summary of the invention

[0011] Technical issues to be solved by the invention

[0012] In recent years, there has been a demand for further improvement in the high temperature characteristics of power storage devices. The present invention relates to maintaining a high capacity even when a power storage device is exposed to a high temperature environment and suppressing the generation of gas in the power storage device.

[0013] Means for solving technical problems

[0014] The present invention comprises the following:

[0015] [1] An additive for a non-aqueous electrolyte solution, comprising a cyclic sulfone compound represented by the following formula (1):

[0016]

[0017] Q represents an optionally substituted alkylene group having 4 to 8 carbon atoms or an optionally substituted alkenylene group having 4 to 8 carbon atoms, which forms a cyclic group together with the sulfur atom of the sulfonyl group,

[0018] X 1 represents a sulfonyl or carbonyl group,

[0019] Z represents a monovalent group represented by the following formula (21), (22), (23) or (24),

[0020]

[0021] R 1 represents a directly bonded or substituted alkylene group having 1 to 6 carbon atoms,

[0022] R 11 and R 12 represents a hydrogen atom, a methyl group or an ethyl group, Q is a tetramethylene group and X 1 When it is a sulfonyl group, R 11 is methyl or ethyl,

[0023] X 2 represents a sulfonyl or carbonyl group,

[0024] Ar represents an arylene group which may be substituted.

[0025] [1'] Use of the cyclic sulfone compound represented by the above formula (1) for adding to a non-aqueous electrolyte.

[0026] [2] The additive for non-aqueous electrolyte according to [1], wherein

[0027] X 1 It is a sulfonyl group.

[0028] [3] The additive for non-aqueous electrolyte according to [1] or [2], wherein

[0029] The cyclic sulfone compound is a compound represented by the following formula (11):

[0030]

[0031] X in formula (11) 1 and Z and X in formula (1) 1 and Z have the same meaning.

[0032] [4] The additive for non-aqueous electrolyte according to [1] or [2], wherein

[0033] The cyclic sulfone compound is a compound represented by the following formula (12):

[0034]

[0035] X in formula (12) 1 and Z and X in formula (1) 1 and Z have the same meaning.

[0036] [5] The additive for a non-aqueous electrolyte according to any one of [1] to [4], wherein

[0037] R 1 is an alkylene group having 1 to 3 carbon atoms which is directly bonded or may be substituted by a fluorine atom,

[0038] Ar is an arylene group which may be substituted with a fluorine atom or a fluoroalkyl group.

[0039] [6] A non-aqueous electrolyte solution comprising the additive for a non-aqueous electrolyte solution according to any one of [1] to [5], a non-aqueous solvent, and an electrolyte.

[0040] [7] A power storage device comprising the nonaqueous electrolyte solution described in [6], a positive electrode, and a negative electrode.

[0041] [8] A lithium ion battery comprising the non-aqueous electrolyte described in [6], a positive electrode, and a negative electrode.

[0042] [9] A lithium ion capacitor comprising the nonaqueous electrolyte solution described in [6], a positive electrode, and a negative electrode.

[0043]

[10] A cyclic sulfone compound represented by the following formula (11S) or (12S):

[0044]

[0045]

[0046] Z represents a monovalent group represented by the following formula (21A) or (22A):

[0047] R 1 represents an alkylene group having 1 to 6 carbon atoms which may be substituted with a fluorine atom.

[11] The cyclic sulfone compound according to

[10] , which is represented by the following formula:

[0048]

[12] The cyclic sulfone compound according to

[10] , which is represented by the following formula:

[0049]

[13] The cyclic sulfone compound according to

[10] , which is represented by the following formula:

[0050]

[0051] Effects of the Invention

[0052] Even when the power storage device is exposed to a high temperature environment, it is possible to maintain a high capacity and suppress the generation of gas in the power storage device. The additive for non-aqueous electrolyte solution according to the present invention can also have excellent performance in terms of stability and handleability. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a cross-sectional view showing an example of an electric storage device. DETAILED DESCRIPTION

[0054] The present invention is not limited to the following examples.

[0055] One example of the additive for non-aqueous electrolyte solution contains one or more cyclic sulfone compounds represented by the following formula (1).

[0056]

[0057] In formula (1), Q is a divalent group that forms a cyclic group together with the sulfur atom of the sulfonyl group, and represents an optionally substituted alkylene group having 4 to 8 carbon atoms or an optionally substituted alkenylene group having 4 to 8 carbon atoms. 1 represents a sulfonyl group or a carbonyl group. Z is a monovalent group represented by the following formula (21), (22), (23) or (24).

[0058]

[0059] R in formula (21) and (22) 1 represents a directly bonded or substituted alkylene group having 1 to 6 carbon atoms. 11 and R 12 represents a hydrogen atom, a methyl group or an ethyl group. 1 When it is a sulfonyl group, R 11 X in formula (22) and (24) is methyl or ethyl. 2 represents a sulfonyl group or a carbonyl group. Ar in the formulae (23) and (24) represents an arylene group which may be substituted.

[0060] In the present specification, "may be substituted" means that one or more hydrogen atoms in each group may be substituted with a substituent.

[0061] It is believed that the cyclic sulfone compound represented by formula (1) undergoes electrochemical reduction during initial charge and discharge, and polymerizes on the electrode through the terminal carbon-carbon unsaturated bond to form a strong SEI. In addition, it is believed that the formed SEI contains polar groups including O, S, etc. in large quantities and at high density. It is believed that this stable SEI containing polar groups at high density can inhibit side reactions, i.e., reactions between electrode active materials and solvents, etc., for example, helping to improve the capacity retention rate during high temperature storage and inhibit gas generation.

[0062] Q in formula (1) is a divalent group constituting a cyclic sulfone, and is replaced by -OX at any position. 1 Q represents an alkylene group having 4 to 8 carbon atoms which may be substituted or an alkenylene group having 4 to 8 carbon atoms which may be substituted, which may be further substituted with -OX 1 The residue is substituted with a substituent other than -Z.

[0063] The alkylene group having 4 to 8 carbon atoms as Q in formula (1) may be a linear alkylene group or a branched alkylene group. Q may be an alkylene group having 1 to 6 carbon atoms which may be substituted by a halogen atom or an alkylene group having 1 to 6 carbon atoms which may be substituted by a fluorine atom.

[0064] When Q is an alkylene group having 4 to 8 carbon atoms, examples thereof include tetramethylene, pentamethylene, 1-methyltetramethylene, 2-methyltetramethylene, hexamethylene, 1-methylpentamethylene, 2-methylpentamethylene, 3-methylpentamethylene, 1-ethyltetramethylene, 1,2-dimethyltetramethylene, heptamethylene, 1-ethylpentamethylene, 1,2-dimethylpentamethylene and octamethylene.

[0065] When Q is an alkylene group having 4 to 8 carbon atoms substituted with a fluorine atom, examples thereof include 1-fluorotetramethylene, 2,3-difluorotetramethylene, 1-fluoropentamethylene, 2-(trifluoromethyl)tetramethylene, 1-fluoro-2-(trifluoromethyl)tetramethylene, 1-fluorohexamethylene, 3-(trifluoromethyl)pentamethylene, 1,2-bis(trifluoromethyl)tetramethylene, 2-(pentafluoroethyl)tetramethylene, 1-fluoroheptamethylene, 1-(trifluoromethyl)hexamethylene, 1-(hexafluoroethyl)pentamethylene, 1-fluorooctamethylene and 1,8-difluorooctamethylene.

[0066] The alkenylene group having 4 to 8 carbon atoms as Q in formula (1) may be a linear alkenylene group or a branched alkenylene group. Q may be an alkenylene group having 4 to 8 carbon atoms which may be substituted by a halogen atom or an alkenylene group having 4 to 8 carbon atoms which may be substituted by a fluorine atom.

[0067] When Q is an alkenylene group having 4 to 8 carbon atoms, examples thereof include -CH=CHCH2CH2-, -CH2CH=CHCH2-, -CH=CHCH2CH2CH2-, -CH2CH=CHCH2CH2-, -CH=C(CH3)CH2CH2-, -CH2(CH3)CH=CHCH2-, -CH=CHCH2CH2CH2-, -CH2CH=CHCH2CH2CH2-, -CH2CH=CHCH2CH2-, -CH2CH2CH=CHCH2CH2-, -C(CH3)=CHCH2CH2CH2-, -CH=C(CH3)CH2CH2CH2-, -CH(CH3)CH=CHCH2CH2-, -CH=CHCH2CH2CH2CH2CH2-, -C(CH3 )=CHCH2CH2CH2CH2-, -C(CH2CH3)=CHCH2CH2CH2, -C(CH3)=C(CH3)CH2CH2CH2- and -CH=CHCH2CH2CH2CH2CH2CH2-.

[0068] When Q is a linear or branched alkenylene group having 4 to 8 carbon atoms which may be substituted with a fluorine atom, examples thereof include -CH=CHCF2CH2-, -CH2CH=CH2CF2-, -CF=CHCH2CH2-, -CH=CFCH2CH2-, -CH=CHCHFCH2CH2-, -CF=CHCH2CH2CH2-, -CH=CH-CH(CF3)CH2-, -CF=CHCH2CH2CH2CH2-, -CH=CHCH(CF)CH2CH2-, -CF=CHCH2CH2CH2CH2CH2-, -CF=CHCH2CH2CH2CH2CH2- and -CF=CHCH2CH2CH2CH2CH2CH2-.

[0069] From the viewpoint of further improving the capacity retention rate during high temperature storage, Q may form a 5-membered ring together with the sulfur atom of the sulfonyl group. In this case, for example, Q may be an alkylene group having 4 carbon atoms which may be substituted by a halogen atom or an alkenylene group having 4 carbon atoms which may be substituted by a halogen atom. From the same viewpoint, Q may be an alkylene group having 4 carbon atoms which may be substituted by a fluorine atom or an alkenylene group having 4 carbon atoms which may be substituted by a fluorine atom.

[0070] From the viewpoint of further suppressing the generation of gas, X in formula (1) 1 It may be a sulfonyl group.

[0071] R in formula (21) and (22) 1 is an unsubstituted or substituted alkylene group having 1 to 6 carbon atoms. The alkylene group having 1 to 6 carbon atoms may be a linear alkylene group or a branched alkylene group. 1The group may be an alkylene group having 1 to 3 carbon atoms and may be substituted with a halogen atom.

[0072] In this specification, "may be substituted by a halogen atom" means that one or more of the hydrogen atoms possessed by each group may be substituted by a halogen atom. The halogen atom as a substituent may be an iodine atom, a bromine atom, a chlorine atom or a fluorine atom, and may be a fluorine atom from the viewpoint of further reducing the battery resistance.

[0073] R 1 In the case of an unsubstituted alkylene group having 1 to 6 carbon atoms, examples thereof include methylene, dimethylene (ethylene), trimethylene (propane-1,3-diyl), propylene (propane-1,2-diyl), tetramethylene (butane-1,3-diyl), 1-methyltrimethylene, 2-methyltrimethylene, 1,1-dimethyldimethylene, 1,2-dimethyldimethylene, ethyldimethylene, pentamethylene (pentane-1,5-diyl) and hexamethylene (hexane-1,6-diyl).

[0074] R 1In the case of an alkylene group having 1 to 6 carbon atoms substituted with a fluorine atom having 1 to 6 carbon atoms, examples thereof include fluoromethylene, difluoromethylene, 1-fluorodimethylene, 1,1-difluorodimethylene, 1,2-difluorodimethylene, 1,1,2-trifluorodimethylene, 1,1,2,2-tetrafluorodimethylene, trifluoromethylmethylene, 1-fluorotrimethylene, 2-fluorotrimethylene, 1,1-difluorotrimethylene, 1,2-difluorotrimethylene, 1,3-difluorotrimethylene, 2,2-difluorotrimethylene, 1,2,3-trifluorotrimethylene, 1,1,2,2,3,3-hexafluorotrimethylene, trifluoromethyldimethylene, 1 -fluorotetramethylene, 2-fluorotetramethylene, 1,1-difluorotetramethylene, 1,1,2,2-tetrafluorotetramethylene, 1,1,2,2,3,3-hexafluorotetramethylene, 1,1,2,2,3,3,4,4-octafluorotetramethylene, 1-(trifluoromethyl)trimethylene, 2-(trifluoromethyl)trimethylene, 1-fluoropentamethylene, 2-fluoropentamethylene, 3-fluoropentamethylene, 1,1-difluoropentamethylene, 1,1,2,2-tetrafluoropentamethylene, 1,1,2,2,3,3-hexafluoropentamethylene, 1,1,2,2,3,3,4,4-octafluoropentamethylene, 1,1,2,2,3,3,4,4,5 ,5-decafluoropentamethylene, 1-(trifluoromethyl)tetramethylene, 2-(trifluoromethyl)tetramethylene, 1,2-bis(trifluoromethyl)trimethylene, 2,2-bis(trifluoromethyl)trimethylene, 1-(pentafluoroethyl)trimethylene, 2-(pentafluoroethyl)trimethylene, 1-fluorohexamethylene, 2-fluorohexamethylene, 3-fluorohexamethylene, 1,1-difluorohexamethylene, 1,1,2,2-tetrafluorohexamethylene, 1,1,2,2,3,3-hexafluorohexamethylene, 1,1,2,2,3,3,4,4-octafluorohexamethylene, 1,1,2,2,3,3,4,4,5,5-decafluorohexamethylene, 1,1,2 ,2,3,3,4,4,5,5,6,6-dodecafluorohexamethylene, 1-(trifluoromethyl)pentamethylene, 2-(trifluoromethyl)pentamethylene, 3-(trifluoromethyl)pentamethylene, 1,1-bis(trifluoromethyl)tetramethylene, 1,2-bis(trifluoromethyl)tetramethylene, 1,3-bis(trifluoromethyl)tetramethylene, 1,4-bis(trifluoromethyl)tetramethylene, 2,2-bis(trifluoromethyl)tetramethylene, 2,3-bis(trifluoromethyl)tetramethylene, 1-(pentafluoroethyl)tetramethylene, 2-(pentafluoroethyl)tetramethylene, 1,2,3-tris(trifluoromethyl)trimethylene and 1-(heptafluoropropyl)trimethylene.

[0075] R 1 It is a methylene group which may be substituted with a fluorine atom, a dimethylene group which may be substituted with a fluorine atom, or a trimethylene group which may be substituted with a fluorine atom.

[0076] Ar in formula (23) and (24) may be an unsubstituted arylene group or a substituted arylene group. Ar may be an arylene group which may be substituted by a halogen atom, a haloalkyl group, an alkyl group (e.g., a methyl group), or a combination thereof. Ar may be an arylene group substituted by a fluorine atom or a fluoroalkyl group (e.g., a fluoromethyl group), or an unsubstituted arylene group. The arylene group substituted by a fluorine atom or a fluoroalkyl group may be further substituted by an alkyl group. The number of carbon atoms in the arylene group may be 6 to 10 or 6.

[0077] When Ar is an unsubstituted arylene group, examples thereof include benzene-1,4-diyl.

[0078] When Ar is an arylene group substituted with a fluorine atom or a fluoroalkyl group, examples thereof include a 2-fluoroarylene group, a 2,3-difluoroarylene group, a 2,5-difluoroarylene group, a 2,6-difluoroarylene group, a 2,3,5-trifluoroarylene group, a 2,3,6-trifluoroarylene group, a 2,3,5,6-tetrafluoroarylene group, a 2-methyl-3-fluoroarylene group, a 2-methyl-5-fluoroarylene group, a 2-methyl-6-fluoroarylene group and a 2-trifluoromethylarylene group.

[0079] When Ar is an arylene group which may be substituted with an alkyl group, examples thereof include a 2,3-dimethylarylene group, a 2,3,5-trimethylarylene group, and a 2,3,5,6-tetramethylarylene group.

[0080] The cyclic sulfone compound represented by the formula (1) may be a compound represented by the following formula (11) or a compound represented by the following formula (12). 1 and Z is the same as X in formula (1) 1 and Z (including examples thereof). These compounds are advantageous from the viewpoint of easy availability of raw materials and simplicity of synthesis.

[0081]

[0082] In particular, the cyclic sulfone compound may be a compound represented by the following formula (11S) or a compound represented by the following formula (12S).

[0083]

[0084] Z in the formula (11S) and (12S) represents a monovalent group represented by the following formula (21A) or (22A).

[0085]

[0086] In formula (21A) and (22A), R 1represents an alkylene group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, and Ar represents an arylene group which may be substituted with a fluorine atom or a fluoroalkyl group.

[0087] Specific examples of the cyclic sulfone compound represented by the formula (1) include compounds represented by the formulae (1-1) to (1-18) shown in Tables 1 and 2 below.

[0088] [Table 1]

[0089]

[0090] [Table 2]

[0091]

[0092] The cyclic sulfone compound represented by formula (1) can be synthesized by a common method understood by those skilled in the art. For example, the cyclic sulfone compound represented by formula (1) can be synthesized by a method including a step of reacting a hydroxy sulfolane having a group corresponding to the cyclic sulfone compound and an acyl chloride compound corresponding to the cyclic sulfone compound in the presence of a base such as triethylamine.

[0093] The additive for non-aqueous electrolyte involved in the present invention may include other components different from the cyclic sulfone compound represented by formula (1) as needed. As examples of other components, negative electrode protective agents, positive electrode protective agents, flame retardants, overcharge inhibitors, cyclic carbonate compounds, nitrile compounds, isocyanate compounds, compounds having acetylene-1,2-diyl (-C≡C-), compounds having sulfonyl groups (>S(=O)2) different from the cyclic sulfone compounds of formula (1), phosphate compounds, acid anhydrides, cyclic phosphazene compounds, boroxine derivatives, compounds containing silicon atoms, and alkyl metal salt compounds (e.g., lithium salt compounds) can be cited. As additives for improving the characteristics of the storage device, these other components can be included in the non-aqueous electrolyte together with the cyclic sulfone compound represented by formula (1). In addition, the alkali metal salt compound also acts as an electrolyte in the non-aqueous electrolyte.

[0094] Examples of cyclic carbonate compounds include 4-fluoro-1,3-dioxolane-2-one (FEC), trans- or cis-4,5-difluoro-1,3-dioxolane-2-one (DFEC), vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and 4-ethynyl-1,3-dioxolane-2-one (EEC). The cyclic carbonate compound may be VC, FEC, VEC, or a combination thereof.

[0095] Examples of the nitrile compound include acetonitrile, propionitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, and sebaconitrile. The nitrile compound may be succinonitrile, adiponitrile, or a combination thereof.

[0096] Examples of the isocyanate compound include methyl isocyanate, ethyl isocyanate, butyl isocyanate, phenyl isocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 1,4-phenylene diisocyanate, 2-isocyanate ethyl acrylate, and 2-isocyanate ethyl methacrylate.

[0097] Examples of compounds having an acetylene-1,2-diyl group (-C≡C-) include 2-propynyl methyl carbonate, 2-propynyl acetate, 2-propynyl formate, 2-propynyl methacrylate, 2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, 2-propynyl 2-(methylsulfonyloxy)propionate, di(2-propynyl) oxalate, methyl-2-propynyl oxalate, ethyl-2-propynyl oxalate, di(2-propynyl) glutarate, 2-butyne-1,4-diyl dimethanesulfonate, 2-butyne-1,4-diyl dicarboxylate, and 2,4-hexadiyn-1,6-dimethylsulfonate.

[0098] Examples of compounds having a sulfonyl group (>S(=O)2) include 1,3-propane sultone (PS), 1,3-butane sultone, 2,4-butane sultone, 1,4-butane sultone, 1,3-propene sultone, 2,2-dioxy-1,2-oxathiolane-4-acetate and 5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, vinyl sulfite, vinyl sulfate, hexahydrobenzo[1,3, 2] Cyclic sulfites such as dioxathiolane-2-oxide (also known as 1,2-cyclohexanediol cyclic sulfite) and 5-vinyl-hexahydro-1,3,2-benzodioxythiol-2-oxide, sulfonates such as butane-2,3-dimethylsulfonate, butane-1,4-dimethylsulfonate, methylenemethane disulfonate and 1,3-propanedisulfonic anhydride, divinyl sulfone, 1,2-bis(vinylsulfonyl)ethane and bis(2-vinylsulfonylethyl)ether.

[0099] Examples of the phosphate ester compound include trimethyl phosphate, tributyl phosphate, trioctyl phosphate, tris(2,2,2-trifluoroethyl) phosphate, bis(2,2,2-trifluoroethyl) methyl phosphate, bis(2,2,2-trifluoroethyl) ethyl phosphate, bis(2,2,2-trifluoroethyl) 2,2-difluoroethyl phosphate, bis(2,2,2-trifluoroethyl) 2,2,3,3-tetrafluoropropyl phosphate, bis(2,2-difluoroethyl) 2,2,2-trifluoroethyl phosphate, bis(2,2,3,3-tetrafluoropropyl) 2,2,2-trifluoroethyl phosphate, (2,2,2-trifluoroethyl) (2,2,3,3-tetrafluoropropyl) methyl phosphate, tris(1,1,1,3,3,3-hexafluoropropane-2-yl) phosphate, methyl methylenebisphosphonate, and methylenebisphosphonate. 2-(dimethylphosphoryl)acetate, ethyl 2-(dimethylphosphoryl)acetate, methyl 2-(diethylphosphoryl)acetate, ethyl 2-(diethylphosphoryl)acetate, 2-propynyl 2-(dimethylphosphoryl)acetate, 2-propynyl 2-(diethylphosphoryl)acetate, methyl 2-(dimethoxyphosphoryl)acetate, ethyl 2-(dimethoxyphosphoryl)acetate, methyl 2-(diethoxyphosphoryl)acetate, ethyl 2-(diethoxyphosphoryl)acetate, 2-propynyl 2-(dimethoxyphosphoryl)acetate, 2-propynyl 2-(diethoxyphosphoryl)acetate, methyl pyrophosphate and ethyl pyrophosphate.

[0100] Examples of the acid anhydride include acetic anhydride, propionic anhydride, succinic anhydride, maleic anhydride, 3-allylsuccinic anhydride, glutaric anhydride, itaconic anhydride and 3-sulfo-propionic anhydride.

[0101] Examples of the cyclic phosphazene compound include methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, and ethoxyheptafluorocyclotetraphosphazene.

[0102] Examples of compounds containing a boron atom include boroxine, trimethylboroxine, trimethoxyboroxine, triethylboroxine, triethoxyboroxine, triisopropoxyboroxine, triisopropoxyboroxine, tri-n-propylboroxine, tri-n-propoxyboroxine, tri-n-butylboroxine, tri-n-butoxyboroxine, triphenylboroxine, triphenoxyboroxine, tricyclohexylboroxine and tricyclohexyloxyboroxine.

[0103] Examples of compounds containing silicon atoms include hexamethylcyclotrisiloxane, hexaethylcyclotrisiloxane, hexaphenylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, trimethylfluorosiloxane, triethylfluorosiloxane, tripropylfluorosiloxane, phenyldimethylfluorosiloxane, triphenylfluorosiloxane, vinyldimethylfluorosiloxane, vinyldiethylfluorosiloxane, vinyldiphenylfluorosiloxane, divinyldifluorosilane, divinyldimethylsilane, trimethoxyfluorosiloxane, triethoxyfluorosiloxane, dimethyldifluorosiloxane, trivinylfluorosilane, trivinylmethylsilane, diethyldifluorosiloxane, divinyldifluorosiloxane, divinyldifluorosiloxane, ethylvinyldifluorosiloxane, methyltrifluorosiloxane, ethyltrifluorosiloxane, hexamethylcyclotetrasiloxane, trimethyl-1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, trimethylfluorosiloxane, triethylfluorosiloxane, triethylfluorosiloxane, divinyldifluorosiloxane, divinyldifluorosiloxane, ethylvinyldifluorosiloxane, methyltrifluorosiloxane, ethyltrifluorosiloxane, hexamethylcyclotetrasiloxane, trimethyl-1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopenta ... Methyldisiloxane, 1,3-diethyltetramethyldisiloxane, hexaethyldisiloxane, octamethyltrisiloxane, methoxytrimethylsiloxane, ethoxytrimethylsiloxane, dimethoxydimethylsilane, trimethoxymethylsiloxane, tetramethoxysilane, tetravinylsilane, tetraallylsilane, tetrabutenylsilane, bis(trimethylsilyl)peroxide, trimethylsilyl acetate, triethylsilyl acetate, trimethylsilyl propionate, trimethylsilyl methacrylate, trimethylsilyl trifluoroacetate, trimethylsilyl methanesulfonate, trimethylsilyl ethanesulfonate, triethylsilyl methanesulfonate, trimethylsilyl fluoromethanesulfonate, bis(trimethylsilyl)sulfate, tris(trimethylsilyl)boron, tris(trimethylsilyl)phosphate, and tris(trimethylsilyl)phosphite.

[0104] Examples of lithium salt compounds include lithium salts having a phosphate skeleton such as lithium difluorophosphate, lithium bis(oxalato)borate (LiBOB), lithium tetrafluoro(oxalate)phosphate (LiTFOP), lithium difluorooxalatoborate (LiDFOB), lithium difluorobis(oxalate)phosphate (LiDFOP), lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, lithium tetrafluoro(oxalate)phosphate and Li2PO3F, and lithium salts having an S(=O) group such as lithium trifluoro((methylsulfonyl)oxy)borate, lithium pentafluoro((methylsulfonyl)oxy)phosphate, lithium methyl sulfate, lithium ethyl sulfate, 2,2,2-trifluoroethyl lithium sulfate and lithium fluorosulfonate.

[0105] Other examples of the alkali metal salt compound include sodium difluorophosphate, potassium difluorophosphate, sodium bisoxalatoborate, potassium bisoxalatoborate, sodium tetrafluoro(oxalato)phosphate, potassium tetrafluoro(oxalato)phosphate, sodium difluorobis(oxalato)phosphate, potassium difluorobis(oxalato)phosphate, sodium difluorooxalatoborate, and potassium difluorooxalatoborate.

[0106] One example of the non-aqueous electrolyte solution contains an additive including a cyclic sulfone compound represented by the formula (1), a non-aqueous solvent, and an electrolyte.

[0107] The content of the cyclic sulfone compound represented by formula (1) in the non-aqueous electrolyte can be appropriately determined in consideration of the effect as an additive, for example, it can be in the range of 0.001 to 10% by mass based on the total mass of the non-aqueous electrolyte. When the content of the cyclic sulfone compound represented by formula (1) is 0.001% by mass or more and 10% by mass or less based on the total mass of the non-aqueous electrolyte, a film (SEI) of appropriate thickness is formed on the electrode, which has a tendency to be particularly effective in suppressing resistance increase. From the same point of view, the content of the cyclic sulfone compound represented by formula (1) can be 0.05% by mass or more and 8% by mass or less, 0.05% by mass or more and 5% by mass or less, 0.05% by mass or more and 4% by mass or less, 0.05% by mass or more and 3% by mass or less, 0.1% by mass or more and 8% by mass or less, 0.1% by mass or more and 5% by mass or less, 0.1% by mass or more and 4% by mass or less, based on the total mass of the non-aqueous electrolyte.

[0108] When the non-aqueous electrolyte further contains other compounds different from the cyclic sulfone compound represented by formula (1) as additives, the content of the other compounds can be 0.001 mass % or more, 10 mass % or less, or 0.001 to 10 mass % based on the total mass of the non-aqueous electrolyte.

[0109] From the viewpoint that the viscosity of the nonaqueous electrolyte is suppressed to be lower, the nonaqueous solvent can be an aprotic solvent. The aprotic solvent can include at least one selected from the group consisting of cyclic carbonate, linear carbonate, aliphatic carboxylic acid ester, lactone, lactam, cyclic ether, linear ether, sulfone, nitrile and their halogen derivatives. The aprotic solvent can include cyclic carbonate or linear carbonate, and can include a combination of cyclic carbonate and linear carbonate.

[0110] Examples of cyclic carbonates include ethylene carbonate, propylene carbonate, butylene carbonate, and fluoroethylene carbonate. Examples of chain carbonates include dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. Examples of aliphatic carboxylic acid esters include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, and methyl trimethylacetate. Examples of lactones include γ-butyrolactone. Examples of lactams include ε-caprolactam and N-methylpyrrolidone. Examples of cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, and 1,3-dioxolane. Examples of chain ethers include 1,2-diethoxyethane and ethoxymethoxyethane. Examples of sulfones include sulfolane. Examples of nitrites include acetonitrile. As examples of halogen derivatives, halogen derivatives of cyclic carbonates such as 4-fluoro-1,3-dioxolane-2-one, 4-chloro-1,3-dioxolane-2-one, and 4,5-difluoro-1,3-dioxolane-2-one can be cited. These can be used alone or in combination of two or more. These non-aqueous solvents are particularly suitable for use in secondary batteries such as lithium ion batteries.

[0111] The content of the nonaqueous solvent in the nonaqueous electrolyte solution may be, for example, 70 to 99% by mass based on the total mass of the nonaqueous electrolyte solution.

[0112] The electrolyte may be a lithium salt that is an ion source of lithium ions or a sodium salt that is an ion source of sodium ions. The electrolyte may include at least one selected from the group consisting of LiAlCl4, LiBF4, LiPF6, LiClO4, LiTFSI (lithium bistrifluoromethanesulfonyl imide), LiFSI (lithium bisfluorosulfonyl imide), LiAsF6 and LiSbF6. As examples of sodium salts, NaPF6, NaBF4, NaClO4, NaAsF, NaCF3SO3, NaN(CF3SO2)2, NaN(C2F5SO2)2 and NaC(CF3SO2)3 may be cited. From the viewpoint of having a high degree of dissociation and being able to improve the ionic conductivity of the electrolyte and further having the effect of suppressing the performance degradation of the storage device caused by long-term use through anti-oxidation-reduction properties, the electrolyte may include LiBF4, LiPF6 or a combination thereof.

[0113] When the electrolyte is LiBF4, LiPF6 or a combination thereof, the non-aqueous solvent may include cyclic carbonate and chain carbonate. LiBF4 and / or LiPF6 may be combined. 6、 Ethylene carbonate and diethyl carbonate.

[0114] The concentration of the electrolyte in the nonaqueous electrolyte is based on the total volume of the nonaqueous electrolyte, and can be more than 0.1mol / L, or can be less than 2.0mol / L. When the concentration of the electrolyte based on the total volume of the nonaqueous electrolyte is more than 0.1mol / L, it is easy to obtain the good conductivity of the nonaqueous electrolyte. When the concentration of the electrolyte based on the total volume of the nonaqueous electrolyte is less than 2.0mol / L, it is particularly easy to ensure the mobility of ions by suppressing the viscosity of the nonaqueous electrolyte. Consider from the same viewpoint, the concentration of the electrolyte based on the total volume of the nonaqueous electrolyte can be more than 0.5mol / L, or can be less than 1.5mol / L.

[0115] The non-aqueous electrolyte may include one or more lithium salts (first lithium salt) selected from the group consisting of LiAlCl4, LiBF4, LiPF6, LiClO4, LiTFSI (lithium bistrifluoromethanesulfonyl imide), LiFSI (lithium bisfluorosulfonyl imide), LiAsF6 and LiSbF6 and one or more second lithium salts different from the first lithium salt. As an example of the second lithium salt, lithium salts having a phosphate skeleton such as lithium difluorophosphate, lithium bisoxalatoborate (LiBOB), lithium tetrafluoro(oxalate)phosphate (LiTFOP), lithium difluorooxalatoborate (LiDFOB), lithium difluorobisoxalatephosphate (LiDFOP), lithium tetrafluoroborate, lithium bisfluorosulfonyl imide, lithium tetrafluoro(oxalate)phosphate, and Li2PO3F, and lithium salts having a S(=O) group such as lithium trifluoro((methylsulfonyl)oxy)borate, lithium pentafluoro((methylsulfonyl)oxy)phosphate, lithium methyl sulfate, lithium ethyl sulfate, 2,2,2-trifluoroethylsulfate, and lithium fluorosulfonate can be cited. The second lithium salt may include one or more lithium salts selected from the group consisting of lithium difluorophosphate, lithium bisoxalatoborate, lithium tetrafluoro(oxalate)phosphate, lithium difluorooxalatoborate, lithium difluorobisoxalatephosphate, lithium methyl sulfate, lithium ethyl sulfate, and lithium fluorosulfonate.

[0116] The concentration of the second lithium salt in the nonaqueous electrolyte may be 1.0 mol / L or less based on the volume of the nonaqueous electrolyte. When the concentration of the second lithium salt is 1.0 mol / L or less, the mobility of the ions can be fully ensured because the viscosity of the nonaqueous electrolyte is not easy to increase. From the same viewpoint, the concentration of the second lithium salt may be 0.8 mol / L or less or 0.5 mol / L or less.

[0117] The non-aqueous electrolyte solution is prepared by, for example, dissolving an additive for a non-aqueous electrolyte solution containing a compound represented by formula (1) together with an electrolyte and other components added as necessary in a non-aqueous solvent.

[0118] The power storage device is mainly composed of the above-mentioned non-aqueous electrolyte, a positive electrode and a negative electrode. Specific examples of the power storage device include non-aqueous electrolyte secondary batteries (lithium ion batteries, sodium ion batteries, lithium sulfur batteries) and electric double layer capacitors (lithium ion capacitors, sodium ion capacitors). The non-aqueous electrolyte involved in the present invention is particularly useful in the use of lithium ion batteries and lithium ion capacitors.

[0119] Figure 1 It is a cross-sectional view schematically showing an example of a non-aqueous electrolyte secondary battery (for example, a lithium ion battery) which is an electricity storage device. Figure 1 The nonaqueous electrolyte secondary battery 1 shown in FIG. 1 includes alternately stacked negative electrodes 4 and positive electrodes 9, a nonaqueous electrolyte 5 disposed between the negative electrodes 4 and the positive electrodes 9, and a separator 6 disposed in the nonaqueous electrolyte 5. The plurality of negative electrodes 4 and positive electrodes 9 are stacked in such a manner that the main surface of the negative electrode 4 and the main surface of the positive electrode 9 face each other via the separator 6. The nonaqueous electrolyte secondary battery 1 includes 7 layers of negative electrodes 4 and 6 layers of positive electrodes 9. Figure 1 In the figure, a part of the repeated structure is omitted. The negative electrode 4 has a negative electrode collector 3 and a negative electrode active material layer 2 provided on both sides of the negative electrode collector 3. The positive electrode 9 has a positive electrode collector 8 and a positive electrode active material layer 7 provided on both sides of the positive electrode collector 8. The non-aqueous electrolyte 5 is the above-mentioned non-aqueous electrolyte for secondary batteries.

[0120] The positive electrode current collector 8 and the negative electrode current collector 3 may be metal foils made of metal such as aluminum, copper, nickel, and stainless steel.

[0121] The positive electrode active material layer 7 contains a positive electrode active material. The positive electrode active material may be a composite oxide containing lithium or a phosphate compound containing lithium. Examples of composite oxides containing lithium include LiMnO2, LiFeO2, LiCoO2, LiMn2O4, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi x Co y M z O2 (wherein 0.01<x<1, 0≤y≤1, 0≤z≤1 and x+y+z=1, M is at least one element selected from the group consisting of Mn, V, Mg, Mo, Nb, Fe, Cu and Al.), Li z Ni (1-x-y) Cox M y O2 (wherein 0≤x≤0.40, 0≤y≤0.40 and 0.90≤z≤1.20, M is at least one element selected from the group consisting of Mn, V, Mg, Mo, Nb and Al.) and Li z Co (1-x) M x O2 (wherein 0≤x≤0.1 and 0.97≤z≤1.20, M is at least one element selected from the group consisting of Mn, Ni, V, Mg, Mo, Nb and Al.) Examples of lithium-containing phosphate compounds include LiFePO4, LiCoPO4, LiMnPO4, LiNiPO4 and composites thereof. When the lithium-containing phosphate compound contains a transition element (Fe, Co, Mn and Ni, etc.), the transition element may be substituted or doped with other elements.

[0122] The positive electrode active material may be Li z Ni (1-x-y) Co x M y O2 (wherein 0.01≤x≤0.20, 0≤y≤0.30 and 0.90≤z≤1.20, M is at least one element selected from the group consisting of Mn, V, Mg, Mo, Nb and Al), Li z Ni (1-x-y) Co x M y O2 (wherein 0.01≤x≤0.15, 0≤y≤0.15 and 0.97≤z≤1.20, M is at least one element selected from Mn, V, Mg, Mo, Nb and Al.) or Li z Co (1-x) M x O2 (wherein 0≤x≤0.1 and 0.97≤z≤1.20, and M is at least one element selected from the group consisting of Mn, Ni, V, Mg, Mo, Nb, and Al.) In this case, SEI is easily formed on the electrode surface, and as a result, the battery performance can be further improved.

[0123] The negative electrode active material layer 2 contains a negative electrode active material. The negative electrode active material is, for example, a material that can absorb and release lithium. Examples of negative electrode active materials include carbon materials such as graphite and amorphous carbon, and oxide materials such as indium oxide, silicon oxide, tin oxide, lithium titanate, zinc oxide and lithium oxide. The negative electrode active material can be lithium metal or a metal material that can form an alloy with lithium. Examples of metals that can form an alloy with lithium include Cu, Sn, Si, Co, Mn, Fe, Sb and Ag. The negative electrode active material may include an alloy containing two or three metals including these metals and lithium. These exemplified negative electrode active materials may be used alone or in combination of two or more.

[0124] From the viewpoint of high energy density, the negative electrode active material may include a carbon material such as graphite and a Si-based active material selected from Si, Si alloys and Si oxides. From the viewpoint of both cycle characteristics and high energy density, the negative electrode active material may include graphite and Si-based active materials. In these cases, the mass ratio of the Si-based active material to the total mass of the carbon material and the Si-based active material may be 0.5 mass %, 1 mass % or more, or 2 mass %, or less than 95 mass %, less than 50 mass % or less than 40 mass %.

[0125] The positive electrode active material layer 7 and the negative electrode active material layer 2 may further include a binder. Examples of binders include polyvinylidene fluoride (PVdF), vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene-butadiene copolymer rubber, carboxymethyl cellulose, polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamide-imide, polyacrylic acid, polyvinyl alcohol, polyacrylic acid metal salt, acrylic acid-polyacrylonitrile, polyacrylamide, polymethacrylic acid and copolymers thereof. The positive electrode active material layer and the negative electrode active material layer may include the same or different binders.

[0126] In order to reduce the resistance, the positive electrode active material layer 7 and the negative electrode active material layer 2 may further contain a conductive auxiliary material. Examples of the conductive auxiliary material include carbon fine particles such as carbon, carbon black, acetylene black, and ketjen black, and carbon fibers.

[0127] The separator 6 may be, for example, a porous film. The porous film may be a film containing a resin selected from polyethylene, polypropylene, fluororesin, etc. The porous film may be a single layer or may have a plurality of layers.

[0128] The specific configurations of the shapes and thicknesses of the components constituting the power storage device can be appropriately set by a person skilled in the art. Figure 1 The implementation methods can be changed appropriately.

[0129] Example

[0130] The present invention will be described in further detail below with reference to Examples. The present invention is not limited to the following Examples.

[0131] 1. Non-aqueous electrolyte

[0132] (Example 1)

[0133] Synthesis of compound (1-1) (compound represented by formula (1-1))

[0134]

[0135] 3-Sulfolane (236.3 g, 2.0 mol) and 500 mL of water were added to a 2L four-necked flask equipped with a stirrer, a condenser, and a thermometer. The reaction solution in the flask was heated to 40°C, and 3-sulfolane was dissolved in water until it became uniform. Sodium hydroxide (104.0 g, 2.6 mol) was added to the reaction solution, and the reaction solution was stirred for 10 hours while maintaining 40°C. Thereafter, the flask was cooled in an ice bath, and concentrated sulfuric acid (130.1 g, 1.3 mol) was added dropwise to the reaction solution over 30 minutes. Thereafter, the solid precipitated by concentrating the reaction solution was filtered out, and 3-hydroxysulfolane (250.59 g, a yield of 92% relative to 3-sulfolane) was obtained by concentrating the obtained filtrate.

[0136] In a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, sodium 2-methyl-2-propene-1-sulfonate (8.04 g, 50 mmol), N,N-dimethylformamide (0.37 g, 5 mmol) and 30 mL of dichloromethane were added. The reaction solution in the flask was stirred at room temperature (25°C), and thionyl chloride (7.14 g, 60 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 20 to 25°C, and the reaction solution was stirred for 24 hours. Thereafter, 2-methyl-2-propene-1-sulfonyl chloride (7.73 g, 100% yield relative to sodium 2-methyl-2-propene-1-sulfonate) was obtained by adding water to the reaction solution, separating the mixed solution, and concentrating the oil layer.

[0137] Next, 3-hydroxycyclopentane sulfone (5.45 g, 40 mmol) obtained above, 2-methyl-2-propylene-1-sulfonyl chloride (6.80 g, 44 mmol) obtained above and acetonitrile 20 mL were added to a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. The flask was cooled in an ice bath, the reaction solution in the flask was stirred, and triethylamine (4.05 g, 40 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 0 to 5° C., and the reaction solution was stirred for 1 hour. Thereafter, water was added and the precipitated white solid was filtered out. After washing the obtained solid with methanol, the compound (1-1) (5.84 g, the yield relative to 3-hydroxycyclopentane sulfone was 50%) was obtained by drying under reduced pressure.

[0138] 1 H-NMR (400MHz, CD3CN), δ (ppm): 1.93 (m, 3H), 2.53 (m, 2H), 3.18 (m, 2H), 3.3 6(dd, 1H), 3.41(dd, 1H), 3.97(s, 2H), 5.15(s, 1H), 5.22(s, 1H), 5.42(m, 1H)

[0139] 13 C-NMR (100MHz, CD3CN) δ (ppm): 22.4, 30.9, 50.0, 57.7, 59.5, 78.0, 121.5, 134.7

[0140] Adjustment of non-aqueous electrolyte

[0141] A mixed non-aqueous solvent was obtained by mixing ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in a volume ratio of EC:EMC=30:70. LiPF6 as an electrolyte was dissolved in the obtained mixed non-aqueous solvent to obtain a LiPF6 solution with a concentration of 1.0 mol / L. Compound (1-1) was added to the obtained LiPF6 solution as an additive for a non-aqueous electrolyte to prepare a non-aqueous electrolyte. The content ratio of the additive for the non-aqueous electrolyte (compound (1-1)) was 1.0 mass % based on the total mass of the non-aqueous electrolyte.

[0142] (Example 2)

[0143] Synthesis of compound (1-5) (compound represented by formula (1-5))

[0144]

[0145] 4-Hydroxy-2-cyclobutane sulfone (5.37 g, 40 mmol), 2-methyl-2-propylene-1-sulfonyl chloride (6.80 g, 44 mmol) obtained in the same manner as in Example 1 and 20 mL of acetonitrile were added to a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. The flask was cooled in an ice bath, the reaction solution in the flask was stirred, and triethylamine (4.05 g, 40 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 0 to 5°C, and the reaction solution was stirred for 1 hour. Thereafter, water was added to the reaction solution, and the precipitated white solid was filtered out. The obtained solid was washed with methanol, and then dried under reduced pressure to obtain compound (1-5) as a white solid (6.98 g, a yield of 69% relative to 4-hydroxy-2-cyclobutane sulfone).

[0146] 1 H-NMR (400MHz, CD3CN) δ (ppm): 1.93 (m, 3H), 3.37 (dd, 1H), 3.70 (dd, 1H), 4.02 (s, 2H), 5.15 (s, 1H), 5.24 (s, 1H), 5.84 (m1H), 6.84 (d, 1H), 7.04 (d, 1H)

[0147] 13 C-NMR (100MHz, CD3CN) δ (ppm): 22.4, 54.8, 59.6, 75.9, 121.8, 134.4, 137.0, 137.8

[0148] Preparation of non-aqueous electrolyte

[0149] A non-aqueous electrolyte solution was prepared in the same manner as in Example 1 except that the compound (1-5) was used as the non-aqueous electrolyte solution additive instead of the compound (1-1).

[0150] (Example 3)

[0151] Synthesis of compound (1-7) (compound represented by formula (1-7))

[0152]

[0153] Potassium 3-(methacryloyloxy)propanesulfonate (24.63 g, 100 mmol), N,N-dimethylformamide (2.19 g, 30 mmol) and 60 mL of tetrahydrofuran were added to a 500 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. The reaction solution in the flask was stirred at room temperature, and thionyl chloride (65.43 g, 550 mmol) was added dropwise over 30 minutes. After the addition was completed, the reaction solution was stirred for 24 hours while maintaining at 20 to 25°C. Thereafter, water was added to the reaction solution and the mixed solution was separated. 3-(methacryloyloxy)propanesulfonyl chloride (22.67 g, 100% yield relative to potassium 3-(methacryloyloxy)propanesulfonate) was obtained by concentrating the oil layer.

[0154] 3-Hydroxycyclopentanesulfone (5.45 g, 40 mmol), 3-(methacryloyloxy)propanesulfonyl chloride (10.86 g, 48 mmol) and 20 mL of acetonitrile obtained in the same manner as in Example 1 were added to a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. The flask was cooled in an ice bath, the reaction solution in the flask was stirred, and triethylamine (4.45 g, 44 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 0 to 5° C., and the reaction solution was stirred for 1 hour. Thereafter, water was added to the reaction solution, and the precipitated white solid was filtered out. The obtained solid was washed with methanol, and then dried under reduced pressure to obtain compound (1-7) as a white solid (4.02 g, a yield of 31% relative to 3-hydroxycyclopentanesulfone).

[0155] 1 H-NMR (400MHz, CD3CN) δ (ppm): 1.93 (m, 3H), 2.15 (m, 2H), 2.54 (m, 2H), 3.17 (m, 2H) ), 3.33(t, 2H), 3.37(ddd, 2H), 4.21(t, 2H), 5.42(m, 1H), 5.63(s, 1H), 6.08(s, 1H)

[0156] 13 C-NMR (100MHz, CD3CN) δ (ppm): 18.5, 24.1, 30.9, 48.9, 50.0, 57.7, 63.0, 77.6, 126.3, 137.5, 167.9

[0157] Preparation of non-aqueous electrolyte

[0158] A non-aqueous electrolyte was prepared in the same manner as in Example 1 except that the compound (1-7) was used as the non-aqueous electrolyte additive instead of the compound (1-1).

[0159] (Example 4)

[0160] Synthesis of compound (1-12) (compound represented by formula (1-12))

[0161]

[0162] Sodium 4-vinylbenzenesulfonate (24.74 g, 120 mmol) and N,N-dimethylformamide (66.00 g, 90 mmol) were added to a 500 mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel. The reaction solution in the flask was stirred at room temperature, and thionyl chloride (92.79 g, 780 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 20 to 25°C, and the reaction solution was stirred for 24 hours. Thereafter, water was added to the reaction solution, and the mixed solution was separated. 4-vinylbenzenesulfonyl chloride (18.00 g, a yield of 74% relative to sodium 4-vinylbenzenesulfonate) was obtained by concentrating the oil layer.

[0163] In a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, 3-hydroxycyclopentane sulfone (4.77 g, 35 mmol) obtained in the same manner as in Example 1, 4-vinylbenzenesulfonyl chloride (10.86 g, 42 mmol) obtained above and 17.5 mL of acetonitrile were added. The flask was cooled in an ice bath, the reaction solution in the flask was stirred, and triethylamine (4.45 g, 44 mmol) was added dropwise. After the addition was completed, the reaction solution was maintained at 0-5°C and stirred for 1 hour. Thereafter, water was added and the precipitated white solid was filtered out. After washing the obtained solid with methanol, compound (1-12) (5.21 g, 49.2% yield relative to 3-hydroxycyclopentane sulfone) was obtained by drying under reduced pressure.

[0164] 1 H-NMR (400MHz, CD3CN) δ (ppm): 2.39 (m, 2H), 3.12 (m, 4H), 5.24 (m, 1H), 5.50 (d, 1H), 6.02 (d, 1H), 6.85 (dd, 1H), 7.70 (d, 2H), 7.90 (d, 2H)

[0165] 13 C-NMR (100MHz, CD3CN) δ (ppm): 30.5, 49.9, 57.3, 78.2, 119.4, 128.3, 129.3, 135.6, 136.1, 144.6

[0166] Preparation of non-aqueous electrolyte

[0167] A non-aqueous electrolyte solution was prepared in the same manner as in Example 1 except that the compound (1-12) was used as the non-aqueous electrolyte solution additive instead of the compound (1-1).

[0168] (Example 5)

[0169] Synthesis of compound (1-15) (compound represented by formula (1-15))

[0170]

[0171] In a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, 3-hydroxycyclopentane sulfone (5.45 g, 40 mmol), methacryloyl chloride (5.44 g, 52 mmol) and acetonitrile 20 mL obtained in the same manner as in Example 1 were added. The flask was cooled in an ice bath, the reaction solution was stirred in the flask, and triethylamine (4.86 g, 48 mmol) was added dropwise. After the addition was completed, the reaction solution was maintained at 0-5°C and stirred for 1 hour. Thereafter, water was added and the precipitated white solid was filtered out. After washing the obtained solid with methanol, compound (1-15) (1.96 g, the yield relative to 3-hydroxycyclopentane sulfone was 24.0%) was obtained by drying under reduced pressure.

[0172] 1 H-NMR (400MHz, CD3CN) δ (ppm): 1.92 (m, 3H), 2.48 (m, 2H), 3.14 (m, 3H), 3.37 (dd, 1H), 5.51 (m, 1H), 5.68 (s, 1H), 6.11 (s, 1H)

[0173] 13 C-NMR (100MHz, CD3CN) δ (ppm): 18.3, 29.7, 50.4, 57.4, 71.4, 127.1, 137.2, 167.1

[0174] Preparation of non-aqueous electrolyte

[0175] A non-aqueous electrolyte solution was prepared in the same manner as in Example 1 except that the compound (1-15) was used as the non-aqueous electrolyte solution additive instead of the compound (1-1).

[0176] (Comparative Example 1)

[0177] In Example 1, the LiPF6 solution (concentration 1.0 mol / L) before adding compound (1-1) was used as the non-aqueous electrolyte solution of Comparative Example 1.

[0178] (Comparative Example 2)

[0179] A nonaqueous electrolyte was prepared in the same manner as in Example 1 except that 1,3-propanesultone (PS, manufactured by Tokyo Chemical Industry Co., Ltd.) was used as a nonaqueous electrolyte additive instead of compound (1-1).

[0180] (Comparative Example 3)

[0181] Synthesis of Compound (A) (3-isopropylsulfonyltetrahydrothiophene-1,1-oxide)

[0182]

[0183] 3-Hydroxycyclopentanesulfone (6.81 g, 50 mmol), isopropylsulfonyl chloride (8.56 g, 60 mmol) and acetonitrile 25 mL obtained in the same manner as in Example 1 were added to a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. The flask was cooled in an ice bath, the reaction solution in the flask was stirred, and triethylamine (5.06 g, 50 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 0 to 5°C, and the reaction solution was stirred for 1 hour. Thereafter, water was added and the precipitated solid was filtered out. The obtained solid was washed with methanol, and then compound (A) (2.31 g, the yield relative to 3-hydroxycyclopentanesulfone was 19%) was obtained by drying under reduced pressure.

[0184] Preparation of non-aqueous electrolyte

[0185] A non-aqueous electrolyte solution was prepared in the same manner as in Example 1 except that the compound (A) was used as the non-aqueous electrolyte solution additive instead of the compound (1-1).

[0186] (Comparative Example 4)

[0187] Synthesis of Compound (B) (3-(4-methylbenzenesulfonyl)tetrahydrothiophene-1,1-dioxide)

[0188]

[0189] 3-Hydroxycyclopentanesulfone (8.17 g, 60 mmol), 4-methylbenzenesulfonyl chloride (13.73 g, 72 mmol) and 30 mL of acetonitrile obtained in the same manner as in Example 1 were added to a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. The flask was cooled in an ice bath, the reaction solution in the flask was stirred, and N,N,N',N'-tetramethylpropylenediamine (3.91 g, 30 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 0-5°C, and the reaction solution was stirred for 1 hour. Thereafter, water was added and the precipitated white solid was filtered out. After washing the obtained white solid with methanol, it was dried under reduced pressure to obtain compound (B) (3.84 g, with a yield of 22% relative to 3-hydroxycyclopentanesulfone).

[0190] Preparation of non-aqueous electrolyte

[0191] A non-aqueous electrolyte was prepared in the same manner as in Example 1, except that the compound (B) was used instead of the compound (1-1).

[0192] (Comparative Example 5)

[0193] Synthesis of Compound (C) (3-acetoxytetrahydrothiophene-1,1-dioxide)

[0194]

[0195] 3-Hydroxycyclopentane sulfone (13.62 g, 100 mmol), acetic anhydride (11.23 g, 110 mmol) and 10 mL of acetonitrile obtained in the same manner as in Example 1 were added to a 200 mL four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel. The flask was cooled in an ice bath, the reaction solution in the flask was stirred, and pyridine (15.82 g, 200 mmol) was added dropwise. After the addition was completed, the temperature was maintained at 0 to 5 ° C, and the reaction solution was stirred for 1 hour. Thereafter, water and dichloromethane were added to the reaction solution, and the mixed solution was separated. Compound (C) (3.97 g, with a yield of 22% relative to 3-hydroxycyclopentane sulfone) was obtained by concentrating the oil layer containing dichloromethane.

[0196] Preparation of non-aqueous electrolyte

[0197] A non-aqueous electrolyte solution was prepared in the same manner as in Example 1 except that the compound (C) was used as the non-aqueous electrolyte solution additive instead of the compound (1-1).

[0198] 2. Fabrication of non-aqueous electrolyte secondary batteries

[0199] A positive electrode sheet (manufactured by Yamaya Co., Ltd.) containing a composite oxide containing lithium and a negative electrode sheet (manufactured by Yamaya Co., Ltd.) containing graphite were prepared. The positive electrode sheet has an aluminum foil (thickness 20 μm) as a positive electrode current collector and a positive electrode active material layer formed on both sides thereof. The positive electrode active material layer contains a composite oxide (LiNi 0.5 Co 0.2 Mn 0.3 O2), carbon black (CB) and carbon (KS) as conductive aids, and polyvinylidene fluoride (PVDF) as a binder. Their mass ratio is lithium-containing composite oxide: CB:KS:PVDF=92:2.5:2.5:3. The negative electrode sheet has a copper foil (thickness 10μm) as a negative electrode collector and a negative electrode active material layer formed on both sides thereof. The negative electrode active material layer contains graphite (Gr) as a negative electrode active material and sodium carboxymethyl cellulose (CMC) and styrene butadiene rubber (SBR) as a binder. Their mass ratio is Gr:CMC:SBR=98:1:1. The negative electrode sheets and the positive electrode sheets are alternately stacked via a separator formed of propylene to produce a battery element with a total of 13 layers, including 7 layers of negative electrode sheets and 6 layers of positive electrode sheets as electrodes.

[0200] The produced battery element is inserted into a bag formed by a laminated film having aluminum (thickness 40 μm) and a resin layer covering both sides thereof, so that the ends of the positive electrode sheet and the negative electrode sheet protrude from the bag. Each non-aqueous electrolyte obtained in the embodiment or the comparative example is added to the bag, and the bag is vacuum-sealed to obtain a sheet-like non-aqueous electrolyte secondary battery. In order to improve the adhesion between the electrodes, the sheet-like non-aqueous electrolyte secondary battery is clamped with a glass plate for pressurization.

[0201] 3. Evaluation

[0202] (Determination of initial capacity)

[0203] After charging each non-aqueous electrolyte secondary battery at 25°C for 1 hour with a current equivalent to 0.1C, it was kept at 25°C for 10 hours. Next, each non-aqueous electrolyte secondary battery was charged for 5 hours with a current equivalent to 0.1C and kept at 45°C for 24 hours. Thereafter, at 25°C, after discharging to 3V with a current equivalent to 0.1C, degassing was performed. After degassing, each non-aqueous electrolyte secondary battery was aged by performing the following operations on each non-aqueous electrolyte secondary battery to stabilize each non-aqueous electrolyte secondary battery: charging to 4.2V with a current equivalent to 0.2C and discharging to 3V with a current equivalent to 0.2C for 3 cycles, charging to 4.2V with a current equivalent to 0.5C and discharging to 3.0V with a current equivalent to 0.5C for 3 cycles, charging to 4.2V with a current equivalent to 1C and discharging to 3.0V with a current equivalent to 1C for 3 cycles. Thereafter, as initial charge and discharge, charge and discharge were performed at a current corresponding to 2.0 C. The discharge capacity observed during the initial charge and discharge was defined as “initial capacity”.

[0204] (Remaining capacity and gas generation rate)

[0205] The volume of each non-aqueous electrolyte secondary battery after the initial capacity measurement was measured by the Archimedes method, and this was taken as the "initial volume" of the battery. At 25°C, each non-aqueous electrolyte secondary battery after the initial charge and discharge was charged to 4.2V at 1C, and then kept at 60°C for 30 hours. Thereafter, each non-aqueous electrolyte secondary battery was cooled to 25°C and discharged to 3V at a current equivalent to 1C. The discharge capacity at this time was set as the "remaining capacity". The volume of each non-aqueous electrolyte secondary battery after being stored at 60°C for 30 days was measured by the Archimedes method, and this was set as the "volume after high-temperature storage". The remaining capacity maintenance rate and gas generation after high-temperature storage were calculated by the following formula. The results are shown in Table 3.

[0206] Remaining capacity maintenance rate (%) = (remaining capacity / initial capacity) × 100

[0207] Gas generation (cm 3 ) = volume after high temperature storage - initial volume

[0208] [Table 3]

[0209]

[0210] Description of Reference Numerals

[0211] 1-lithium-ion battery, 2-negative electrode active material layer, 3-negative electrode collector, 4-negative electrode, 5-nonaqueous electrolyte, 6-separator, 7-positive electrode active material layer, 8-positive electrode collector, 9-positive electrode.

Claims

1. An additive for a non-aqueous electrolyte, comprising a cyclic sulfone compound represented by the following formula (1), Q represents an optionally substituted alkylene group having 4 to 8 carbon atoms or an optionally substituted alkenylene group having 4 to 8 carbon atoms, which forms a cyclic group together with the sulfur atom of the sulfonyl group, X 1 represents a sulfonyl or carbonyl group, Z represents a monovalent group represented by the following formula (21), (22), (23) or (24), R 1 represents a directly bonded or substituted alkylene group having 1 to 6 carbon atoms, R 11 and R 12 represents a hydrogen atom, a methyl group or an ethyl group, Q is tetramethylene and X 1 When it is a sulfonyl group, R 11 is methyl or ethyl, X 2 represents a sulfonyl or carbonyl group, Ar represents an arylene group which may be substituted.

2. The additive for non-aqueous electrolyte according to claim 1, wherein X 1 It is a sulfonyl group.

3. The additive for non-aqueous electrolyte according to claim 1 or 2, wherein The cyclic sulfone compound is a compound represented by the following formula (11): X in formula (11) 1 and Z and X in formula (1) 1 and Z have the same meaning.

4. The additive for non-aqueous electrolyte according to claim 1 or 2, wherein The cyclic sulfone compound is a compound represented by the following formula (12): X in formula (12) 1 and Z and X in formula (1) 1 and Z have the same meaning.

5. The additive for non-aqueous electrolyte according to claim 1 or 2, wherein R 1 is an alkylene group having 1 to 3 carbon atoms which is directly bonded or may be substituted by a fluorine atom, Ar is an arylene group which may be substituted with a fluorine atom or a fluoroalkyl group. 6 . A non-aqueous electrolyte solution comprising the additive for a non-aqueous electrolyte solution according to claim 1 or 2 , a non-aqueous solvent and an electrolyte. 7 . An electricity storage device comprising the nonaqueous electrolyte according to claim 6 , a positive electrode, and a negative electrode.

8. A lithium ion battery comprising the nonaqueous electrolyte according to claim 6, a positive electrode and a negative electrode. 9 . A lithium ion capacitor comprising the nonaqueous electrolyte according to claim 6 , a positive electrode and a negative electrode.

10. A cyclic sulfone compound represented by the following formula (11S) or (12S): Z represents a monovalent group represented by the following formula (21A) or (22A): R 1 It represents an alkylene group having 1 to 6 carbon atoms which may be substituted with a fluorine atom.

11. The cyclic sulfone compound according to claim 10, which is represented by the following formula:

12. The cyclic sulfone compound according to claim 10, which is represented by the following formula:

13. The cyclic sulfone compound according to claim 10, which is represented by the following formula: 。

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