Surface treatment agent for electrode material, positive electrode active material, conductive foil, negative electrode active material, conductive additive, electrode, battery, method for producing positive electrode active material, method for producing conductive additive, and method for producing electrode

Abstract

The invention aims to provide a method and device. Provided are a surface treatment agent for an electrode material, a positive electrode active material, a current collector foil, a negative electrode active material, a conductive assistant, an electrode, a battery, a method for producing a positive electrode active material, a method for producing a current collector foil, and a method for producing a negative electrode active material, with which it is possible to improve the cycle characteristics of a battery and suppress corrosion of the current collector foil. A method for producing a conductive auxiliary agent and a method for producing an electrode are provided. The present disclosure is a surface treatment agent for an electrode material having a pyridine skeleton and fluorine.

Description

Technical Field

[0001] The present disclosure relates to a surface treatment agent for an electrode material, a positive electrode active material, a current collector foil, a negative electrode active material, a conductive aid, an electrode, a battery, a method for producing a positive electrode active material, a method for producing a current collector foil, a method for producing a negative electrode active material, a method for producing a conductive aid, and a method for producing an electrode. Background Art

[0002] With the recent trend of lightweight and miniaturization of electrical products, the development of electrochemical devices such as lithium-ion secondary batteries with high energy density is being promoted. In addition, as the application fields of electrochemical devices such as lithium-ion secondary batteries expand, it is expected that the characteristics will be improved. In particular, when lithium-ion secondary batteries are used in automotive applications in the future, the improvement of battery characteristics will become increasingly important.

[0003] As a method for improving battery characteristics, for example, Patent Document 1 describes an electrode current collector made of aluminum and having fluorine on the surface.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-183256 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] The purpose of the present disclosure is to provide a surface treatment agent for electrode materials, a positive electrode active material, a current collector foil, a negative electrode active material, a conductive aid, an electrode, a battery, a method for manufacturing a positive electrode active material, a method for manufacturing a current collector foil, a method for manufacturing a negative electrode active material, a method for manufacturing a conductive aid, and a method for manufacturing an electrode, which can improve the cycle characteristics of a battery and inhibit the corrosion of a current collector foil.

[0009] Technical solutions for solving technical problems

[0010] The present disclosure (1) is a surface treatment agent for an electrode material having a pyridine skeleton and fluorine.

[0011] The present disclosure (2) is the surface treatment agent for an electrode material according to the present disclosure (1), which is an N-fluoropyridinium compound or a fluorinated halogen·pyridine·HF complex.

[0012] The present disclosure (3) is a surface treatment agent for an electrode material according to the present disclosure (2), wherein the N-fluoropyridinium compound is 1,1′-difluoro-2,2′-bipyridylbis(tetrafluoroborate), and the fluorinated halogen·pyridine·HF complex is IF 5 ·Pyridine·HF complex.

[0013] The present disclosure (4) is a surface treatment agent for an electrode material according to any one of the present disclosures (1) to (3), which is used for a positive electrode active material, a current collecting foil, a negative electrode active material, a conductive aid or an electrode.

[0014] The present disclosure (5) is a positive electrode active material treated with the electrode material surface treatment agent described in any one of the present disclosures (1) to (4).

[0015] The present disclosure (6) is a current collecting foil treated with the electrode material surface treatment agent described in any one of the present disclosures (1) to (4).

[0016] The present disclosure (7) is a negative electrode active material treated with the electrode material surface treatment agent described in any one of the present disclosures (1) to (4).

[0017] The present disclosure (8) is a conductive auxiliary agent treated with the electrode material surface treatment agent described in any one of the present disclosures (1) to (4).

[0018] The present disclosure (9) is an electrode comprising at least one selected from the positive electrode active material described in the present disclosure (5), the current collecting foil described in the present disclosure (6), and the conductive auxiliary agent described in the present disclosure (8).

[0019] The present disclosure (10) is an electrode comprising at least one selected from the negative electrode active material described in the present disclosure (7), the current collecting foil described in the present disclosure (6), and the conductive auxiliary agent described in the present disclosure (8).

[0020] The present disclosure (11) is a battery comprising the electrode described in the present disclosure (9) or (10).

[0021] The present disclosure (12) is a method for producing a positive electrode active material according to the present disclosure (5), wherein a solution containing the electrode material surface treatment agent according to any one of the present disclosures (1) to (4) is brought into contact with the positive electrode active material.

[0022] The present disclosure (13) is a method for producing the current collector foil according to the present disclosure (6), wherein a solution containing the electrode material surface treatment agent according to any one of the present disclosures (1) to (4) is brought into contact with the current collector foil.

[0023] The present disclosure (14) is a method for producing the negative electrode active material according to the present disclosure (7), wherein a solution containing the electrode material surface treatment agent according to any one of the present disclosures (1) to (4) is brought into contact with the negative electrode active material.

[0024] The present disclosure (15) is a method for producing the conductive auxiliary agent according to the present disclosure (8), wherein a solution containing the electrode material surface treatment agent according to any one of the present disclosures (1) to (4) is brought into contact with the conductive auxiliary agent.

[0025] The present disclosure (16) is a method for producing an electrode, wherein a solution containing the electrode material surface treatment agent according to any one of the present disclosures (1) to (4) is brought into contact with an electrode containing a current collector foil and a positive electrode active material or a negative electrode active material.

[0026] Effects of the Invention

[0027] According to the present disclosure, it is possible to provide a surface treatment agent for electrode materials, a positive electrode active material, a current collector foil, a negative electrode active material, a conductive aid, an electrode, a battery, a method for manufacturing a positive electrode active material, a method for manufacturing a current collector foil, a method for manufacturing a negative electrode active material, a method for manufacturing a conductive aid, and a method for manufacturing an electrode, which can improve the cycle characteristics of a battery and inhibit the corrosion of a current collector foil. DETAILED DESCRIPTION

[0028] Hereinafter, the present disclosure will be described in detail.

[0029] <Surface treatment agents for electrode materials>

[0030] The present disclosure relates to a surface treatment agent for an electrode material having a pyridine skeleton and fluorine.

[0031] By treating the surface of the electrode active material, the current collector foil, etc. with the above-mentioned electrode material surface treatment agent, the surface is fluorinated. It can be inferred that by forming a stable protective film using the fluorine on the surface and the above-mentioned electrode material surface treatment agent remaining on the surface after reaction and unreacted, the cycle characteristics of the battery (such as the capacity retention rate after the cycle) can be improved, and the corrosion of the current collector foil can be inhibited.

[0032] Furthermore, by leaving the surface treatment agent for the electrode material, an effect of improving ion conductivity can be expected.

[0033] Therefore, a high-performance battery with high energy density can be provided.

[0034] In addition, compared with the method of fluorinating an object using fluorine gas as in the example of Patent Document 1, the above-mentioned surface treatment agent for an electrode material has advantages of excellent safety and handleability.

[0035] The surface treatment agent for an electrode material has a pyridine skeleton and fluorine.

[0036] In the surface treatment agent for electrode materials, the number of pyridine skeletons may be 1 or 2 or more; however, it is preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less.

[0037] In the electrode material surface treatment agent, the number of fluorine atoms may be 1 or 2 or more, preferably 2 or more, preferably 20 or less, more preferably 12 or less, and further preferably 8 or less.

[0038] As the surface treatment agent for the electrode material, an N-fluoropyridinium compound or a halogen fluoride·pyridine·HF complex can be preferably used.

[0039] The N-fluoropyridinium compound can preferably be a compound represented by the following formula (A1), or

[0040] [Chemistry 1]

[0041]

[0042] The compound represented by the following formula (A2).

[0043] [Chemistry 2]

[0044]

[0045] In the general formulas (A1) to (A2),

[0046] Adjacent R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , or R 4 and R 5 Can be linked to form -CR 6 =CR 7 -CR 8 =CR 9 -,

[0047] In addition, R 1 ′ and R 2 ′、R 2 ′ and R 3 ′、R 3 ′ and R 4 ', or R 4 ′ and R 5 ' can be linked to form -CR 6 ′=CR 7 ′-CR 8 ′=CR 9 ′-,

[0048] R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7, R 8 , R 9 , R 1 ′, R 2 ′, R 3 ′, R 4 ′, R 5 ′, R 6 ′, R 7 ′, R 8 ′ and R 9' are the same or different and are all the following structures: a hydrogen atom; a halogen atom; a nitro group; a hydroxyl group; a cyano group; a carbamoyl group; an alkyl group having 1 to 15 carbon atoms which may be substituted by at least one selected from a halogen atom, a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an acyl group having 2 to 5 carbon atoms (such as alkanoyl), an acyloxy group having 2 to 5 carbon atoms (such as alkanoyloxy) and an aryl group having 6 to 10 carbon atoms; an alkenyl group having 1 to 15 carbon atoms which may be substituted by at least one selected from a halogen atom and an aryl group having 6 to 10 carbon atoms; an alkynyl group having 1 to 15 carbon atoms which may be substituted by at least one selected from a halogen atom and an aryl group having 6 to 10 carbon atoms; an aryl group having 6 to 15 carbon atoms substituted with at least one selected from the group consisting of an alkyl group having 1 to 5 carbon atoms; an acyl group having 1 to 15 carbon atoms (such as an alkanoyl group) which may be substituted with at least one halogen atom; an alkoxycarbonyl group having 2 to 15 carbon atoms which may be substituted with at least one selected from the group consisting of a halogen atom and an aryl group having 6 to 10 carbon atoms; an aryloxycarbonyl group having 7 to 15 carbon atoms which may be substituted with at least one selected from the group consisting of a halogen atom and an alkyl group having 1 to 5 carbon atoms; an alkylsulfonyl group having 1 to 15 carbon atoms which may be substituted with at least one selected from the group consisting of a halogen atom and an aryl group having 6 to 10 carbon atoms; an arylsulfonyl group having 6 to 15 carbon atoms which may be substituted with at least one selected from the group consisting of a halogen atom and an alkyl group having 1 to 5 carbon atoms Acyl group; alkylsulfinyl group having 1 to 15 carbon atoms which may be substituted by at least one selected from halogen atoms and aryl groups having 6 to 10 carbon atoms; arylsulfinyl group having 6 to 15 carbon atoms which may be substituted by at least one selected from halogen atoms and alkyl groups having 1 to 5 carbon atoms; alkoxy group having 1 to 15 carbon atoms which may be substituted by at least one selected from halogen atoms and aryl groups having 6 to 10 carbon atoms; aryloxy group having 6 to 15 carbon atoms which may be substituted by at least one selected from halogen atoms and alkyl groups having 1 to 5 carbon atoms; acyloxy group having 1 to 15 carbon atoms (such as alkanoyloxy group) which may be substituted by at least one halogen atom; acylthio group having 1 to 15 carbon atoms which may be substituted by at least one halogen atom (alkanoylthio, etc.); alkanesulfonyloxy group having 1 to 15 carbon atoms which may be substituted by at least one selected from halogen atoms and aryl groups having 6 to 10 carbon atoms; arylsulfonyloxy group having 6 to 15 carbon atoms which may be substituted by at least one selected from halogen atoms and alkyl groups having 1 to 5 carbon atoms; carbamoyl group which may be substituted by at least one selected from alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 10 carbon atoms; amino group which may be substituted by at least one selected from acyl groups having 1 to 5 carbon atoms (alkanoyl, etc.) and halogen atoms; N-alkylpyridinium group having 6 to 15 carbon atoms which may be substituted by at least one selected from halogen atoms, aryl groups having 6 to 10 carbon atoms and alkyl groups having 1 to 5 carbon atoms;an N-arylpyridinium salt group having 11 to 15 carbon atoms which may be substituted with at least one selected from the group consisting of a halogen atom, an aryl group having 6 to 10 carbon atoms, and an alkyl group having 1 to 5 carbon atoms; or an organic polymer chain, R; 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 1 ′、R 2 ′、R 3 ′、R 4 ′、R 5 ′、R 6 ′、R 7 ′、R 8 ′ and R 9 ' can form a ring structure through various combinations with or without heteroatoms,

[0049] In the general formula (A2), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 One of them and R 1 ′、R 2 ′、R 3 ′、R 4 ′、R 5 ′、R 6 ′、R 7 ′、R 8 ′ and R 9 One of the ' is bonded with a single bond to form a bond chain.

[0050] in addition,

[0051] [Chemistry 3]

[0052]

[0053] The same or different, is the conjugate base of the Brønsted acid.

[0054] Examples of the Bronsted acid include methanesulfonic acid, butanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, nitrobenzenesulfonic acid, dinitrobenzenesulfonic acid, trinitrobenzenesulfonic acid, trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, perfluorobutanesulfonic acid, perfluorooctanesulfonic acid, perfluoro(2-ethoxyethane)sulfonic acid, perfluoro(4-ethylcyclohexane)sulfonic acid, trichloromethanesulfonic acid, difluoromethanesulfonic acid, trifluoroethanesulfonic acid, fluorosulfonic acid, chlorosulfonic acid, camphorsulfonic acid, bromocamphorsulfonic acid, Δ 4 -cholesten-3-one-6-sulfonic acid, 1-hydroxy-p-menthane-2-sulfonic acid, p-styrenesulfonic acid, β-styrenesulfonic acid, vinylsulfonic acid, perfluoro-3,6-dioxa-4-methyl-7-octenesulphonic acid and other sulfonic acids; sulfuric acid, phosphoric acid, nitric acid and other inorganic acids; perchloric acid, perbromic acid, periodic acid, chloric acid, bromic acid and other halogen acids; monomethylsulfuric acid, monoethylsulfuric acid and other monoalkylsulfuric acid; acetic acid, formic acid, trichloroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, dichloroacetic acid, acrylic acid and other carboxylic acids; HAlF 4 HBF 4 HB 2 F 7 , HPF 6 ,HSbF 4 ,HSbF 6 HSb 2 F 11 , HAsF 6 , HAlCl 4 , HAlCl 3 F; HAlF 3 Cl, HBCl 4 HBCl 3 F, HBBr 3 F、HSbCl 6 HSbCl 5 Compounds of Lewis acids such as F and hydrogen halides; HB Ph 4 (Ph is phenyl; the same below),

[0055] [Chemistry 4]

[0056]

[0057] Etc. aromatic substituted boron compounds; (FSO 2 ) 2 NH, (PhSO 2 ) 2 NH, (CF 3 SO 2 ) 2 NH, (C 2 F 5 SO 2 ) 2 NH, (C 4 F 9 SO2 ) 2 NH, (HCF 2 CF 2 SO 2 ) 2 NH, CF 3 SO 2 NHSO 2 C 6 F 13 ,

[0058] [Chemistry 5]

[0059]

[0060] Acidic amide compounds such as (FSO 2 ) 3 CH, (CF 3 SO 2 ) 3 CH, (PhOSO 2 ) 3 CH(Ph is phenyl), (CF 3 SO 2 ) 2 CH 2 ,(CF 3 SO 2 ) 3 CH, (C 4 F 9 SO 2 ) 3 CH, (C 8 F 17 SO 2 ) 3 CH and other carbon oxides, etc.

[0061] As the Bronsted acid, from the viewpoint of the stability of the compound, a Bronsted acid having stronger acidity than acetic acid (pKa: 4.56) is particularly preferred.

[0062] As the conjugate base of the Bronsted acid, for example, particularly preferred are: - BF 4 , - PF 6 , - AH 6 , - Sb 6 , - AlF 4 , - AlCl 4 , - SbCl 6 , - SbCl 5F. - Sb 2 F 11 , - B 2 F 7 , - OClO 3 , - OSO 2 F. - OSO 2 Cl, - OSO 2 OH, - OSO 2 OCH 3 , - OSO 2 CH 3 , - OSO 2 CF 3 , - OSO 2 CCl 3 , - OSO 2 C 4 F 9 , - OSO 2 C 6 H 5 , - OSO 2 C 6 H 4 CH 3 , - OSO 2 C 6 H 4 NO 2 , - N(SO 2 CF 3 ) 2 Etc. Among them, tetrafluoroborate ( - BF 4 ) or perfluoroalkyl sulfonate ( - OSO 2 CF 3 , - OSO 2 C 4 F 9 etc.), more preferably tetrafluoroborate ( - BF 4 ).

[0063] The compound represented by the above formula (A1) is preferably a compound represented by the following formula (A1a).

[0064] [Chemistry 6]

[0065]

[0066] (Where R 1a , R 2a , R 3a , R 4a and R 5a the same or different, and are all hydrogen, an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a halogen atom, a phenyl group which may be substituted with a methyl group or a halogen, an alkoxy group having 1 to 4 carbon atoms, an acyl group having 2 to 4 carbon atoms (such as an alkanoyl group), an acyloxy group having 2 to 4 carbon atoms (such as an alkanoyloxy group), an alkoxycarbonyl group having 2 to 4 carbon atoms, a cyano group, or a nitro group;

[0067] [Chemistry 7]

[0068]

[0069] It is the conjugate base of a Bronsted acid with a pKa below 4.56.

[0070] The compound represented by the above formula (A2) is preferably a compound represented by the following formula (A2a).

[0071] [Chemistry 8]

[0072]

[0073] (Where R 1a , R 2a , R 3a , R 4a , R 5a , R 1a′ , R 2a′ , R 3a′ , R 4a′ and R 5a′ are the same or different and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a halogen atom, a phenyl group which may be substituted with a methyl group or a halogen, an alkoxy group having 1 to 4 carbon atoms, an acyl group having 2 to 4 carbon atoms (such as an alkanoyl group), an acyloxy group having 2 to 4 carbon atoms (such as an alkanoyloxy group), an alkoxycarbonyl group having 2 to 4 carbon atoms, a cyano group, or a nitro group, R 1a , R 2a , R 3a , R 4a , R 5a One of them and R 1a′ , R 2a′ , R 3a′ , R 4a′ , R 5a′ One of them is bonded with a single bond to form a bond chain,

[0074] [Chemistry 9]

[0075] and / or

[0076] It is the conjugate base of a Bronsted acid with a pKa below 4.56.

[0077] In the compounds represented by the above general formulae (A1a) and (A2a), R 1a , R 2a , R 3a , R 4a , R 5a , R 1a′ , R 2a′ , R 3a′ , R 4a′ and R 5a′ The higher the electron donating property, the higher the stability; and the higher the electron withdrawing property, the higher the reactivity. From this point of view, it can be appropriately selected according to the required characteristics.

[0078] As the above-mentioned N-fluoropyridinium compound, from the perspective of improving the cycle characteristics of the battery and suppressing the corrosion of the current collector foil, the compound represented by the above-mentioned formula (A2) is preferred, the compound represented by the above-mentioned formula (A2a) is more preferred, and 1,1′-difluoro-2,2′-bipyridylbis(tetrafluoroborate) is further preferred.

[0079] In the above-mentioned halogen fluoride·pyridine·HF complex, as the halogen fluoride, for example, a compound of the formula: XF n (wherein X is chlorine, bromine or iodine, and n is a natural number of 1 to 5.) X is preferably iodine or bromine, more preferably iodine. n is preferably 3 to 5, particularly preferably 5.

[0080] In the above-mentioned halogen fluoride·pyridine·HF complex, the number of halogen fluoride may be 1 or 2 or more, and is preferably 1. The same applies to pyridine and HF.

[0081] As the above-mentioned halogen fluoride·pyridine·HF composite, IF is preferred from the viewpoint of the improvement effect of the cycle characteristics of the battery and the suppression effect of the corrosion of the current collector foil. 5 ·Pyridine·HF complex.

[0082] The above-mentioned surface treatment agents for electrode materials may be used alone or in combination of two or more.

[0083] The surface treatment agent for an electrode material can be used for a positive electrode active material, a current collecting foil, a negative electrode active material, a conductive auxiliary agent or an electrode.

[0084] The present disclosure also relates to a positive electrode active material, a current collecting foil, a negative electrode active material, a conductive aid, and an electrode treated with the surface treatment agent for the electrode material.

[0085] <Positive electrode active material>

[0086] The surface of the positive electrode active material is fluorinated by the surface treatment agent for the electrode material. The proportion of fluorine on the surface of the positive electrode active material is preferably 2.5 atomic % or more, more preferably 3.2 atomic % or more, and further preferably 3.6 atomic % or more; and is preferably 6.5 atomic % or less, more preferably 5.5 atomic % or less, and further preferably 4.5 atomic % or less.

[0087] The ratio of fluorine on the surface of the positive electrode active material can be measured by energy dispersive X-ray spectroscopy (SEM-EDX) using a scanning electron microscope.

[0088] A stable protective film can be formed by the unreacted and reacted surface treatment agent for the electrode material remaining on the surface of the positive electrode active material. The amount (total amount) of the unreacted and reacted surface treatment agent for the electrode material remaining on the surface of the positive electrode active material is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.15% by mass or more; and preferably 5.0% by mass or less, more preferably 1.0% by mass or less, and further preferably 0.3% by mass or less.

[0089] The amount of the unreacted and reacted surface treatment agent for electrode material remaining on the surface of the positive electrode active material can be calculated from the mass difference between the positive electrode active material before and after the treatment measured using a precision electronic balance.

[0090] As the positive electrode active material, there is no particular limitation as long as it is a material that can electrochemically absorb and release lithium ions, and examples thereof include: lithium-containing transition metal composite oxides, lithium-containing transition metal phosphate compounds, sulfur-based materials, conductive polymers, etc. Among them, as the positive electrode active material, preferably lithium-containing transition metal composite oxides, lithium-containing transition metal phosphate compounds, particularly preferably lithium-containing transition metal composite oxides that generate high voltage.

[0091] In the case of a high voltage system, there are concerns about the oxidative decomposition of the electrolyte, the dissolution of metal ions from the positive electrode active material, the corrosion of the current collector foil, etc., but by using the above-mentioned electrode material surface treatment agent, the occurrence of these problems can be suppressed. That is, the above-mentioned electrode material surface treatment agent is particularly suitable for materials of a high voltage system.

[0092] In addition, in this specification, "high voltage" means a voltage of 4.2V or more. In addition, the upper limit of "high voltage" is preferably 4.9V.

[0093] As the transition metal of the above-mentioned lithium-containing transition metal composite oxide, V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferred; as a specific example, LiCoO 2 Lithium-cobalt composite oxide, LiNiO 2 Lithium-nickel composite oxide, LiMnO 2 、LiMn 2 O 4 , Li 2 MnO 4 Lithium-manganese composite oxides, lithium-containing transition metal composite oxides obtained by replacing part of the transition metal atoms serving as the main components of these lithium transition metal composite oxides with other elements such as Na, K, B, F, Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, and W. Specific examples of the substituted lithium-containing transition metal composite oxides include: LiNi 0.5 Mn 0.5 O 2 、LiNi 0.85 Co 0.10 Al 0.05 O 2 、LiNi 0.5 Co 0.2 Mn 0.3 O 2 、LiNi 0.6 Co 0.2 Mn 0.2 O 2 、LiNi 0.33 Co 0.33 Mn 0.33 O 2 、LiNi 0.8 Co 0.1 Mn 0.1 O 2 、LiNi 0.45 Co 0.10 Al 0.45 O 2 、LiMn 1.8 Al 0.2 O 4 、LiNi 0.5 Mn 1.5 O 4 wait.

[0094] Among them, as the lithium-containing transition metal composite oxide, LiNi is preferably used, which has a high energy density even when a high voltage is used. 0.5 Mn 1.5 O 4 、LiNi 0.5 Co 0.2 Mn 0.3 O 2 、LiNi 0.6 Co 0.2 Mn 0.2 O 2 Among them, LiNi is preferred in the case of high voltages above 4.4V. 0.5 Mn 1.5 O 4 .

[0095] Among them, LiNi is preferred as the lithium-containing transition metal composite oxide from the viewpoint of being able to provide a high-capacity lithium-ion secondary battery. 0.6 Co 0.2 Mn 0.2 O 2 、LiNi 0.8 Co 0.1 Mn 0.1 O 2 、LiNi 0.85 Co 0.10 Al 0.05 O 2 .

[0096] As the transition metal in the lithium-containing transition metal phosphate compound, V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferred; as a specific example, LiFePO 4 , Li 3 Fe 2 (PO 4 ) 3 、LiFeP 2 O 7 Iron phosphate, LiCoPO 4 Cobalt phosphates, etc., lithium-containing transition metal phosphate compounds in which part of the transition metal atoms serving as the main body of these lithium transition metal phosphate compounds are replaced by other elements such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si, etc.

[0097] Examples of the lithium-containing transition metal composite oxide include

[0098] Formula: Li a Mn 2-b M 1 b O4 (Wherein, 0.9≤a; 0≤b≤1.5; M 1 A lithium-manganese spinel composite oxide represented by at least one metal selected from Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge,

[0099] Formula: LiNi 1-c M 2 c O 2 (Wherein, 0≤c≤0.5; M 2 A lithium-nickel composite oxide represented by at least one metal selected from Fe, Co, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge, or

[0100] Formula: LiCo 1-d M 3 d O 2 (Wherein, 0≤d≤0.5; M 3 The present invention relates to a lithium-cobalt composite oxide represented by at least one metal selected from Fe, Ni, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge.

[0101] Among them, LiCoO is preferred from the viewpoint of being able to provide a lithium ion secondary battery with high energy density and high output. 2 、LiMnO 2 、LiNiO 2 、LiMn 2 O 4 、LiNi 0.8 Co 0.15 Al 0.05 O 2 , or LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 .

[0102] As other positive electrode active materials, LiFePO 4 、LiNi 0.8 Co 0.2 O 2 , Li 1.2 Fe 0.4 Mn 0.4 O 2 、LiNi 0.5 Mn 0.5 O 2 , LiV 3O 6 , Li 2 MnO 3 wait.

[0103] As the sulfur-based material, a material containing a sulfur atom can be exemplified, preferably at least one selected from elemental sulfur, metal sulfide, and organic sulfur compound, and more preferably elemental sulfur. The metal sulfide may be a metal polysulfide. The organic sulfur compound may be an organic polysulfide.

[0104] Examples of the metal sulfide include LiS x (0<x≤8) represented by the compound; Li 2 S x (0<x≤8) represented by the compound; TiS 2 、MoS 2 Compounds with two-dimensional layered structures; general formula Me x Mo 6 S 8 (Me is various transition metals represented by Pb, Ag, and Cu) and the like having a strong three-dimensional skeleton structure represented by Chevreul phase compounds.

[0105] Examples of the organic sulfur compound include carbon sulfide compounds and the like.

[0106] The above-mentioned organic sulfur compound is sometimes supported on a material having small pores such as carbon and used as a carbon composite material. From the viewpoint of further excellent cycle performance and further reduced overvoltage, the content of sulfur contained in the carbon composite material is preferably 10 to 99% by mass, more preferably 20% by mass or more, further preferably 30% by mass or more, particularly preferably 40% by mass or more, and preferably 85% by mass or less.

[0107] When the positive electrode active material is the sulfur single substance, the content of sulfur contained in the positive electrode active material is equal to the content of the sulfur single substance.

[0108] Examples of the conductive polymer include p-doped conductive polymers and n-doped conductive polymers. Examples of the conductive polymer include polyacetylenes, polyphenylenes, heterocyclic polymers, ionic polymers, ladder polymers, and network polymers.

[0109] In addition, if lithium phosphate is included in the above-mentioned positive electrode active material, the continuous charging characteristics are improved, so it is preferred. There is no restriction on the use of lithium phosphate, and it is preferred to use the above-mentioned positive electrode active material and lithium phosphate in mixture. As the amount of lithium phosphate used, the lower limit is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more, relative to the total of the above-mentioned positive electrode active material and lithium phosphate; the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, and further preferably 5% by mass or less.

[0110] In addition, a material obtained by attaching a substance having a different composition to the surface of the above-mentioned positive electrode active material can be used. Examples of the surface-attached substance include oxides such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, and bismuth oxide; sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, and aluminum sulfate; carbonates such as lithium carbonate, calcium carbonate, and magnesium carbonate; and carbon.

[0111] These surface-attached substances can be attached to the surface of the positive electrode active material by, for example, a method of dissolving or suspending in a solvent and impregnating and adding to the positive electrode active material and then drying, a method of dissolving or suspending a surface-attached substance precursor in a solvent and impregnating and adding to the positive electrode active material and then reacting by heating, etc., a method of adding to the positive electrode active material precursor and calcining at the same time, etc. It should be noted that in the case of attaching carbon, a method of mechanically attaching the carbon in the form of, for example, activated carbon can also be used.

[0112] As the amount of the above-mentioned surface-attached substance, in terms of mass relative to the above-mentioned positive electrode active material, as the lower limit, preferably 0.1ppm or more, more preferably 1ppm or more, and further preferably 10ppm or more; as the upper limit, preferably 20% or less, more preferably 10% or less, and further preferably 5% or less. The surface-attached substance can inhibit the oxidation reaction of the electrolyte on the surface of the positive electrode active material and improve the battery life, but when the amount of its attachment is too small, its effect cannot be fully manifested; when it is too much, it hinders the entry and exit of lithium ions, so sometimes the resistance increases.

[0113] The shape of the particles of the positive electrode active material may be block, polyhedral, spherical, ellipsoidal, plate, needle, columnar, etc. Primary particles may be aggregated to form secondary particles.

[0114] The tap density of the positive electrode active material is usually 1.5 g / cm 3 Above, preferably 2.0 g / cm 3 More preferably, 2.5 g / cm 3 Above, most preferably 3.0g / cm3 If the tap density of the positive electrode active material is lower than the above lower limit, the amount of dispersion medium required when the positive electrode active material layer is formed increases, and the amount of conductive material and binder required increases. Sometimes the filling rate of the positive electrode active material into the positive electrode active material layer is restricted, and the battery capacity is limited. By using a metal composite oxide powder with a high tap density, a high-density positive electrode active material layer can be formed. The larger the tap density, the better. There is no particular upper limit, and it is usually 4.5g / cm 3 Below, preferably 4.3 g / cm 3 the following.

[0115] It should be noted that in the present disclosure, the tap density is determined as follows: 5 g to 10 g of the positive electrode active material powder is placed in a 10 ml glass measuring cylinder and tapped 200 times with an amplitude of about 20 mm. The powder packing density (tap density) at this time is g / cm 3 As the tap density.

[0116] The median diameter d50 of the above-mentioned positive electrode active material particles (secondary particle diameter when the primary particles aggregate to form secondary particles) is preferably 0.3 μm or more, more preferably 0.5 μm or more, further preferably 0.8 μm or more, and most preferably 1.0 μm or more; and preferably 30 μm or less, more preferably 27 μm or less, further preferably 25 μm or less, and most preferably 22 μm or less. If it is lower than the above lower limit, it is sometimes impossible to obtain a product with a high tap density; if it is greater than the upper limit, the diffusion of lithium in the particles will take time, so sometimes the battery performance is reduced, or when the positive electrode of the battery is made, that is, the active material and the conductive material, adhesive, etc. are slurried with a solvent and coated into a thin film, problems such as pulling out stripes sometimes occur. Here, the filling property when making the positive electrode can be further improved by mixing two or more of the above-mentioned positive electrode active materials with different median diameters d50.

[0117] It should be noted that in the present disclosure, the median diameter d50 is measured using a known laser diffraction / scattering particle size distribution measuring device. When using LA-920 manufactured by HORIBA as a particle size distribution meter, a 0.1% by mass sodium hexametaphosphate aqueous solution is used as the dispersion medium used during the measurement, and after 5 minutes of ultrasonic dispersion, the measured refractive index is set to 1.24 for measurement.

[0118] In the case where primary particles aggregate to form secondary particles, the average primary particle size of the above-mentioned positive electrode active material is preferably 0.05 μm or more, more preferably 0.1 μm or more, and further preferably 0.2 μm or more; the upper limit is preferably 5 μm or less, more preferably 4 μm or less, further preferably 3 μm or less, and most preferably 2 μm or less. When the above upper limit is exceeded, it is difficult to form spherical secondary particles, which sometimes has an adverse effect on the filling property of the powder; or because the specific surface area is greatly reduced, the possibility of reduced battery performance such as output characteristics increases. On the contrary, if it is lower than the above lower limit, the crystal is usually not developed, so sometimes problems such as poor reversibility of charge and discharge occur.

[0119] It should be noted that in the present disclosure, the primary particle size can be measured by observation using a scanning electron microscope (SEM). Specifically, in a photograph with a magnification of 10,000 times, for any 50 primary particles, the longest value of the line segment intercepted by the left and right boundaries of the primary particles to the straight line in the horizontal direction is obtained, and the average value is obtained.

[0120] The BET specific surface area of ​​the positive electrode active material is preferably 0.1 m 2 / g or more, more preferably 0.2m 2 / g or more, more preferably 0.3m 2 / g or more, and the upper limit is preferably 50m 2 / g or less, more preferably 40m 2 / g or less, more preferably 30m 2 If the BET specific surface area is smaller than this range, the battery performance is likely to be reduced, while if it is larger than this range, it is difficult to increase the tap density, which may easily cause problems in coating properties when forming the positive electrode active material layer.

[0121] In addition, in the present disclosure, the BET specific surface area is defined as a value measured by the following method: using a surface area meter (e.g., a fully automatic surface area measuring device manufactured by Ohkura Riken Co. Ltd.), after pre-drying the sample at 150° C. for 30 minutes under nitrogen flow, using a nitrogen-helium mixed gas in which the relative pressure value of nitrogen relative to atmospheric pressure is accurately adjusted to 0.3, the sample is measured by a nitrogen adsorption BET 1-point method based on a gas flow method.

[0122] Large lithium-ion secondary batteries used in hybrid vehicles and distributed power sources are required to have high output, and therefore the particles of the positive electrode active material are preferably mainly composed of secondary particles.

[0123] The particles of the positive electrode active material preferably have an average particle size of secondary particles of 40 μm or less and contain 0.5 to 7.0 volume % of particles with an average primary particle size of 1 μm or less. By containing particles with an average primary particle size of 1 μm or less, the contact area with the electrolyte becomes larger, which can accelerate the diffusion of lithium ions between the electrode and the electrolyte, resulting in the ability to improve the output performance of the battery.

[0124] As a method for producing the positive electrode active material, a conventional method for producing an inorganic compound is used. In particular, various methods can be considered to produce a spherical or ellipsoidal active material, for example, the following method can be cited: dissolving or crushing a transition metal raw material in a solvent such as water, adjusting the pH while stirring, producing a spherical precursor, drying it as needed, and adding LiOH, Li 2 CO 3 、LiNO 3 The active material is obtained by sintering with lithium source at high temperature.

[0125] The above-mentioned positive electrode active material may be used alone or in any combination or ratio. A preferred combination in this case is LiCoO 2 、LiNi 0.33 Co 0.33 Mn 0.33 O 2 LiMn 2 O 4 or a combination of materials in which a portion of Mn is replaced by other transition metals, or LiCoO 2 Or a combination of substances in which a part of Co is replaced with other transition metals or the like.

[0126] <Current Collector Foil>

[0127] The surface of the current collector foil is fluorinated by the surface treatment agent for the electrode material. The proportion of fluorine on the surface of the current collector foil is preferably 0.5 atomic % or more, more preferably 0.7 atomic % or more, and further preferably 0.9 atomic % or more; and is preferably 3.5 atomic % or less, more preferably 2.5 atomic % or less, and further preferably 2.0 atomic % or less.

[0128] The ratio of fluorine on the surface of the current collector foil can be measured by energy dispersive X-ray spectroscopy (SEM-EDX) using a scanning electron microscope.

[0129] The unreacted and reacted electrode material surface treatment agent remaining on the surface of the current collector foil can form a stable protective film. The amount (total amount) of the unreacted and reacted electrode material surface treatment agent remaining on the surface of the current collector foil is usually very small and difficult to measure.

[0130] As the material of the current collecting foil, there can be cited: metal materials such as aluminum, titanium, tantalum, stainless steel, nickel, copper, or their alloys; carbon materials such as carbon cloth and carbon paper. Among them, metal materials are preferred. In addition, aluminum or its alloys are preferred in the case of the positive electrode, and copper or its alloys are preferred in the case of the negative electrode.

[0131] In addition, when the material of the current collecting foil is aluminum, corrosion may occur under high voltage; however, by using the surface treatment agent for the electrode material, the corrosion of aluminum can be suppressed.

[0132] The thickness of the current collector foil is arbitrary, usually 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more; and usually 1 mm or less, preferably 100 μm or less, more preferably 50 μm or less. If the film is thinner than this range, the strength required as a current collector is sometimes insufficient. On the contrary, if the film is thicker than this range, the handling property is sometimes impaired.

[0133] In addition, from the viewpoint of reducing the electrical contact resistance between the current collecting foil and the active material layer, it is also preferred to apply a conductive additive on the surface of the current collecting foil. Examples of the conductive additive include carbon or precious metals such as gold, platinum, and silver.

[0134] The current collector foil of the present disclosure is suitable for electrodes of batteries such as lithium ion secondary batteries, but can also be used for electrodes of electrochemical devices other than batteries such as electric double layer capacitors.

[0135] <Negative electrode active material>

[0136] The surface of the negative electrode active material is fluorinated by the surface treatment agent for the electrode material. The proportion of fluorine on the surface of the negative electrode active material is preferably 2.5 atomic % or more, more preferably 3.2 atomic % or more, and further preferably 3.6 atomic % or more; and is preferably 8.5 atomic % or less, more preferably 7.5 atomic % or less, and further preferably 6.5 atomic % or less.

[0137] The ratio of fluorine on the surface of the negative electrode active material can be measured by energy dispersive X-ray spectroscopy (SEM-EDX) using a scanning electron microscope.

[0138] A stable protective film can be formed by the unreacted and reacted surface treatment agent for the electrode material remaining on the surface of the negative electrode active material. The amount (total amount) of the unreacted and reacted surface treatment agent for the electrode material remaining on the surface of the negative electrode active material is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more; and preferably 5.0% by mass or less, more preferably 2.0% by mass or less, and further preferably 0.5% by mass or less.

[0139] The amount of the unreacted and reacted electrode material surface treatment agent remaining on the surface of the negative electrode active material can be calculated from the mass difference between the negative electrode active material before and after the treatment measured using a precision electronic balance.

[0140] The negative electrode active material is not particularly limited as long as it can electrochemically absorb and release lithium ions. Specific examples include: carbonaceous materials that can absorb and release lithium, such as thermal decomposition products of organic matter under various thermal decomposition conditions, artificial graphite, natural graphite, etc.; metal oxide materials that can absorb and release lithium, such as tin oxide and silicon oxide; lithium metal; various lithium alloys; lithium-containing metal composite oxide materials; conductive polymers, etc. These negative electrode active materials can be used in combination of two or more.

[0141] The surface treatment agent for electrode material fluorinates the surface of the negative electrode active material and forms a protective film on the surface of the negative electrode active material, thereby suppressing the reduction and decomposition of the electrolyte solution during each cycle of the battery and suppressing the increase in resistance.

[0142] As a carbonaceous material capable of absorbing and releasing lithium, it is preferred that the carbonaceous material is an artificial graphite or a refined natural graphite made by high-temperature treatment of an easily graphitized pitch obtained from various raw materials, or a material obtained by carbonizing these graphite after surface treatment with organic matter such as pitch, etc., selected from natural graphite, artificial graphite, artificial carbonaceous material and artificial graphite material, which are heat-treated once or more in the range of 400 to 3200 ° C, a carbonaceous material having an interface of carbonaceous materials with different crystalline states and / or carbonaceous materials with different crystalline states in contact with each other, and a carbonaceous material having an interface of carbonaceous materials with carbonaceous materials with different orientations in contact with each other in the negative electrode active material layer. The balance of the initial irreversible capacity and high current density charge-discharge characteristics of the material is good, which is more preferred. In addition, these carbon materials can be used alone, or two or more can be used in any combination and ratio.

[0143] As the above-mentioned carbonaceous materials obtained by heat treating the artificial carbonaceous material and the artificial graphite material at a temperature in the range of 400 to 3200°C for more than one time, there can be cited: coal-based coke, petroleum-based coke, coal-based asphalt, petroleum-based asphalt and carbonaceous materials obtained by oxidation treatment of these asphalts, needle coke, asphalt coke and carbon agents obtained by partial graphitization thereof, furnace black, acetylene black, thermal decomposition products of organic substances such as asphalt-based carbon fibers, carbonizable organic substances and their carbides, or solutions obtained by dissolving carbonizable organic substances in low molecular weight organic solvents such as benzene, toluene, xylene, quinoline, n-hexane and their carbides, etc.

[0144] As the metal material used as the above-mentioned negative electrode active material (excluding lithium titanium composite oxide), as long as it can absorb and release lithium, it can be lithium alone, a single metal and alloy forming a lithium alloy, or any of their oxides, carbides, nitrides, silicides, sulfides or phosphides, etc., without special restrictions. As a single metal and alloy forming a lithium alloy, it is preferably a material containing metal and semi-metal elements of Groups 13 and 14, and more preferably a single metal of aluminum, silicon and tin (hereinafter referred to as "specific metal elements") and an alloy or compound containing these atoms. They can be used alone or in any combination and ratio.

[0145] As the negative electrode active material having at least one atom selected from the specific metal element, it can be cited: a metal single substance of any one specific metal element, an alloy containing two or more specific metal elements, an alloy containing one or more specific metal elements and other one or more metal elements, and a compound containing one or more specific metal elements, and a composite compound such as an oxide, carbide, nitride, silicide, sulfide or phosphide of the compound. By using these metal single substances, alloys or metal compounds as negative electrode active materials, the battery can be high-capacity.

[0146] In addition, compounds obtained by complex bonding of these composite compounds with a variety of elements such as metal simple substances, alloys or non-metallic elements can also be cited. Specifically, for example, in the case of silicon or tin, alloys of these elements and metals that do not function as negative electrodes can also be used. For example, in the case of tin, a complex compound containing 5 to 6 elements such as a combination of tin and a metal that functions as a negative electrode other than silicon, a metal that does not function as a negative electrode, and a non-metallic element can also be used.

[0147] Specifically, Si single substance, SiB 4 、SiB 6 Mg 2 Si、Ni 2 Si、TiSi2 、MoSi 2 、CoSi 2 、NiSi 2 、CaSi 2 ,CrSi 2 , Cu 6 Si、FeSi 2 、MnSi 2 、NbSi 2 、TaSi 2 、VSi 2 、W Si 2 、ZnSi 2 、SiC、Si 3 N 4 、Si 2 N 2 O、SiO v (0<v≤2), LiSiO or tin, SnSiO 3 、LiSnO、Mg 2 Sn、SnO w (0<w≤2).

[0148] In addition, a composite material having Si or Sn as a first constituent element and containing a second and a third constituent element in addition thereto can be mentioned. The second constituent element is, for example, at least one of cobalt, iron, magnesium, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium and zirconium. The third constituent element is, for example, at least one of boron, carbon, aluminum and phosphorus.

[0149] In particular, from the viewpoint of obtaining a high battery capacity and excellent battery characteristics, the metal material is preferably a simple substance of silicon or tin (which may contain a trace amount of impurities), SiO v (0<v≤2), SnO w (0≤w≤2), Si-Co-C composite material, Si-Ni-C composite material, Sn-Co-C composite material, Sn-N iC composite material.

[0150] As a lithium-containing metal composite oxide material used as a negative electrode active material, there is no particular restriction as long as it can absorb and release lithium. From the perspective of high current density charge and discharge characteristics, a material containing titanium and lithium is preferred, a lithium-containing composite metal oxide material containing titanium is more preferred, and a composite oxide of lithium and titanium (hereinafter referred to as "lithium-titanium composite oxide") is further preferred. That is, if a lithium-titanium composite oxide having a spinel structure is contained and used in the negative electrode active material for an electrolyte battery, the output resistance is greatly reduced, so it is particularly preferred.

[0151] As the lithium-titanium composite oxide, preferably the general formula:

[0152] Lix Ti y M z O 4

[0153] [In the formula, M represents at least one element selected from the group consisting of Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb.]

[0154] The compounds shown.

[0155] In the above composition,

[0156] (i)1.2≤x≤1.4, 1.5≤y≤1.7, z=0

[0157] (ii)0.9≤x≤1.1, 1.9≤y≤2.1, z=0

[0158] (iii)0.7≤x≤0.9, 2.1≤y≤2.3, z=0

[0159] The structure has a good balance in battery performance and is therefore particularly preferred.

[0160] A particularly preferred representative composition of the above compound is Li in (i) 4 / 3 Ti 5 / 3 O 4 , in (ii) is Li 1 Ti 2 O 4 , in (iii) is Li 4 / 5 Ti 11 / 5 O 4 In addition, regarding the structure of Z≠0, for example, Li 4 / 3 T i 4 / 3 Al 1 / 3 O 4 As a preferred structure.

[0161] <Conductive additives (conductive materials)>

[0162] The surface of the conductive aid is fluorinated by the surface treatment agent for the electrode material. The proportion of fluorine on the surface of the conductive aid is preferably 3.5 atomic % or more, more preferably 4.0 atomic % or more, and further preferably 4.5 atomic % or more; and is preferably 9.5 atomic % or less, more preferably 8.5 atomic % or less, and further preferably 7.5 atomic % or less.

[0163] The ratio of fluorine on the surface of the conductive auxiliary agent can be measured by energy dispersive X-ray spectroscopy (SEM-EDX) using a scanning electron microscope.

[0164] The unreacted and reacted surface treatment agent for the electrode material remaining on the surface of the conductive auxiliary agent can form a stable protective film. The amount (total amount) of the unreacted and reacted surface treatment agent for the electrode material remaining on the surface of the conductive auxiliary agent is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more; and preferably 5.0% by mass or less, more preferably 2.0% by mass or less, and further preferably 0.5% by mass or less.

[0165] The amount of the electrode material surface treatment agent remaining on the surface of the conductive agent and the amount of the electrode material surface treatment agent after reaction can be calculated from the difference in mass of the conductive agent before and after the treatment measured using a precision electronic balance.

[0166] Specific examples of the conductive additive include metal materials such as copper and nickel; graphites such as natural graphite and artificial graphite; carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; and carbon materials such as amorphous carbon such as needle coke, carbon nanotubes, fullerene, and VGCF. Among them, carbon materials are preferred.

[0167] In addition, these may be used individually by 1 type, and may use 2 or more types together in arbitrary combinations and ratios.

[0168] <Electrode>

[0169] As the electrode, an electrode including at least one of the positive electrode active material, the current collecting foil, the negative electrode active material, and the conductive additive can be used. However, the positive electrode active material and the negative electrode active material may include only one of them.

[0170] The surface of the electrode is fluorinated by the surface treatment agent for the electrode material. The proportion of fluorine on the surface of the electrode is preferably 2.5 atomic % or more, more preferably 3.3 atomic % or more, and further preferably 3.6 atomic % or more; and is preferably 6.5 atomic % or less, more preferably 5.5 atomic % or less, and further preferably 4.5 atomic % or less.

[0171] The ratio of fluorine on the surface of the electrode can be measured by energy dispersive X-ray spectroscopy (SEM-EDX) using a scanning electron microscope.

[0172] The unreacted and reacted surface treatment agent for electrode material remaining on the surface of the electrode can form a stable protective film. The amount (total amount) of the unreacted and reacted surface treatment agent for electrode material remaining on the surface of the electrode is usually very small and difficult to measure.

[0173] When the electrode is a positive electrode containing the positive electrode active material, the positive electrode is composed of a positive electrode active material layer containing the positive electrode active material and a current collecting foil. The current collecting foil may be the current collecting foil of the present disclosure treated with the surface treating agent for the electrode material, or may be other current collecting foils, but the current collecting foil of the present disclosure is preferred.

[0174] From the viewpoint of high battery capacity, the content of the above-mentioned positive electrode active material is preferably 50 to 99.5% by mass of the positive electrode mixture, and more preferably 80 to 99% by mass. In addition, the content of the positive electrode active material in the positive electrode active material layer is preferably 80% by mass or more, more preferably 82% by mass or more, and particularly preferably 84% by mass or more. In addition, the upper limit is preferably 99% by mass or less, and more preferably 98% by mass or less. If the content of the positive electrode active material in the positive electrode active material layer is low, the capacitance is sometimes insufficient. On the contrary, if the content is too high, the strength of the positive electrode is sometimes insufficient.

[0175] In the above-mentioned positive electrode mixture, the content of the above-mentioned surface treatment agent for the electrode material is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, and further preferably 0.1 mass% or more; and is preferably 10 mass% or less, more preferably 5 mass% or less, and further preferably 3 mass% or less.

[0176] When the electrode is a negative electrode containing the negative electrode active material, the negative electrode is composed of a negative electrode active material layer containing the negative electrode active material and a current collecting foil. The current collecting foil may be the current collecting foil of the present disclosure treated with the surface treating agent for the electrode material, or may be other current collecting foils, but the current collecting foil of the present disclosure is preferred.

[0177] From the viewpoint of high battery capacity, the content of the above-mentioned negative electrode active material is preferably 50 to 99.5% by mass of the negative electrode mixture, and more preferably 80 to 99% by mass. In addition, the content of the negative electrode active material in the negative electrode active material layer is preferably 80% by mass or more, more preferably 82% by mass or more, and particularly preferably 84% by mass or more. In addition, the upper limit is preferably 99% by mass or less, and more preferably 98% by mass or less. If the content of the negative electrode active material in the negative electrode active material layer is low, the capacity is sometimes insufficient. On the contrary, if the content is too high, the strength of the negative electrode is sometimes insufficient.

[0178] In the above-mentioned negative electrode mixture, the content of the above-mentioned surface treatment agent for the electrode material is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, and further preferably 0.1 mass% or more; and is preferably 10 mass% or less, more preferably 5 mass% or less, and further preferably 3 mass% or less.

[0179] The amount of the electrode material surface treatment agent in the electrode mixture is the total amount of the unreacted and reacted electrode material surface treatment agents, and is a value (estimated value) calculated from the input amounts of each material.

[0180] The positive electrode mixture and the negative electrode mixture preferably contain a conductive aid. The conductive aid may be the conductive aid of the present disclosure treated with the surface treatment agent for the electrode material, or may be another conductive aid, but the conductive aid of the present disclosure is preferred. It should be noted that they may be used alone or in any combination and ratio.

[0181] In the positive electrode mixture and the negative electrode mixture, the content of the conductive aid is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more; and is usually 50% by mass or less, preferably 30% by mass or less, more preferably 15% by mass or less. If the content is lower than this range, the conductivity is sometimes insufficient. On the contrary, if the content is higher than this range, the battery capacity is sometimes reduced.

[0182] The positive electrode mixture and the negative electrode mixture preferably further contain a binder and a thickener.

[0183] As the above-mentioned binder, any binder can be used as long as it is a material safe for the solvent and electrolyte used in manufacturing the electrode, for example, resin polymers such as polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, chitosan, alginic acid, polyacrylic acid, polyimide, cellulose, nitrocellulose, etc.; rubber polymers such as SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), ethylene-propylene rubber, etc.; styrene-butadiene-styrene block copolymers or its hydrogenated product; thermoplastic elastomer polymers such as EPDM (ethylene-propylene-diene terpolymer), styrene-ethylene-butadiene-styrene copolymer, styrene-isoprene-styrene block copolymer or its hydrogenated product; soft resin polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene-vinyl acetate copolymer, propylene-α-olefin copolymer; fluorine-based polymers such as polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride copolymer, tetrafluoroethylene-ethylene copolymer; polymer compositions having ion conductivity of alkali metal ions (especially lithium ions), etc. These may be used alone or in any combination and ratio.

[0184] In the above-mentioned positive electrode mixture and the above-mentioned negative electrode mixture, the content of the above-mentioned binder is usually 0.1% by mass or more, preferably 1% by mass or more, and more preferably 1.5% by mass or more; and, usually 80% by mass or less, preferably 60% by mass or less, more preferably 40% by mass or less, and most preferably 10% by mass or less. If the above-mentioned binder is too little, the electrode active material cannot be fully maintained, the mechanical strength of the electrode is insufficient, and sometimes the battery performance such as the cycle characteristics deteriorates. On the other hand, if it is too much, it sometimes leads to a decrease in battery capacity and conductivity.

[0185] Examples of the thickener include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein, polyvinyl pyrrolidone, and salts thereof. The thickener may be used alone or in any combination and ratio.

[0186] In the above-mentioned positive electrode mixture and the above-mentioned negative electrode mixture, the content of the above-mentioned thickener is usually 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass or more; and, it is usually 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less. If it is lower than this range, the coating property is sometimes significantly reduced. If it is greater than this range, the proportion of the active material in the electrode mixture is reduced, sometimes resulting in a problem of reduced battery capacity or increased resistance between electrode active materials.

[0187] In the above-mentioned electrode, the ratio of the thickness of the current collector foil to the electrode active material layer is not particularly limited, and the value of (the thickness of the electrode active material layer on one side when the electrolyte is to be injected) / (the thickness of the current collector) is preferably less than 20, more preferably less than 15, and most preferably less than 10; and preferably more than 0.5, more preferably more than 0.8, and most preferably more than 1. If it is greater than this range, the current collector sometimes generates heat due to Joule heat during high current density charging and discharging. If it is less than this range, the volume ratio of the current collector to the electrode active material increases, and sometimes the capacity of the battery decreases.

[0188] The above-mentioned electrode can be manufactured according to conventional methods. For example, a method of adding the above-mentioned binder, thickener, conductive material, solvent, etc. to the above-mentioned positive electrode active material or the above-mentioned negative electrode active material to prepare a slurry-like positive electrode mixture or negative electrode mixture, applying it on a current collector and pressing it after drying to obtain a high density can be cited.

[0189] Furthermore, when an alloy material is used, a method of forming a thin film layer (electrode active material layer) by a method such as a vapor deposition method, a sputtering method, a plating method, etc. may also be used.

[0190] As a solvent for forming the above-mentioned slurry, as long as it is a solvent that can dissolve or disperse the positive electrode active material, the negative electrode active material, the conductive auxiliary agent, the binder, and the thickener used as needed, its type is not particularly limited, and any of aqueous solvents and organic solvents can be used. As an aqueous solvent, for example, water, a mixed solvent of alcohol and water, etc. can be cited. As an organic solvent, for example, aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as benzene, toluene, xylene, methylnaphthalene; heterocyclic compounds such as quinoline and pyridine; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; esters such as methyl acetate and methyl acrylate; amines such as diethylenetriamine and N,N-dimethylaminopropylamine; ethers such as diethyl ether, propylene oxide, and tetrahydrofuran (THF); amides such as N-methylpyrrolidone (NMP), dimethylformamide, and dimethylacetamide; non-protonic polar solvents such as hexamethylphosphoramide and dimethyl sulfoxide, etc.

[0191] The density increase can be achieved by hand pressing, roll pressing, etc. The density of the positive electrode active material layer is preferably 1.5 g / cm 3 More preferably 2 g / cm 3 More preferably, 2.2 g / cm 3 More than; and, preferably 5g / cm 3 Below, more preferably 4.5g / cm 3 Below, more preferably 4g / cm 3 If the range is exceeded, the permeability of the electrolyte to the interface of the current collector / active material is reduced, and the charge and discharge characteristics at high current density are reduced, and sometimes high output cannot be obtained. In addition, if it is below this range, the conductivity between the active materials is reduced, the battery resistance is increased, and sometimes high output cannot be obtained.

[0192] The area of ​​the positive electrode active material layer is preferably larger than the surface area of ​​the battery outer casing. Specifically, the sum of the electrode areas of the positive electrode is preferably 15 times or more, more preferably 40 times or more, in terms of area ratio relative to the surface area of ​​the outer casing of the secondary battery. The surface area of ​​the battery outer casing refers to the total area calculated from the length, width and thickness of the shell portion filled with the power generation element except the protruding portion of the terminal in the case of a square shape with a bottom. In the case of a cylindrical shape with a bottom, it is the geometric surface area of ​​the shell portion filled with the power generation element except the protruding portion of the terminal, which is approximated as a cylinder. The sum of the electrode areas of the positive electrode refers to the geometric surface area of ​​the positive electrode mixture layer relative to the mixture layer containing the negative electrode active material. In a structure in which the positive electrode mixture layer is formed on both sides via a current collector foil, it refers to the sum of the areas of each face calculated separately.

[0193] The thickness of the positive electrode plate is not particularly limited, but from the perspective of high capacity and high output, the lower limit of the thickness of the composite layer obtained by deducting the thickness of the core metal foil is preferably 10 μm or more, more preferably 20 μm or more for a single side of the current collector; and preferably 500 μm or less, more preferably 450 μm or less.

[0194] In addition, a material obtained by attaching a substance having a different composition to the surface of the positive electrode plate may be used. Examples of the surface-attached substance include oxides such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, and bismuth oxide; sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, and aluminum sulfate; carbonates such as lithium carbonate, calcium carbonate, and magnesium carbonate; and carbon.

[0195] The thickness of the negative electrode plate is designed to match the positive electrode plate used, and there is no particular restriction, but the thickness of the composite layer after deducting the thickness of the core metal foil is usually 15 μm or more, preferably 20 μm or more, and more preferably 30 μm or more; and is usually 300 μm or less, preferably 280 μm or less, and more preferably 250 μm or less.

[0196] In addition, a negative electrode plate having a material having a different composition attached to the surface of the negative electrode plate may be used. Examples of the surface-attached material include oxides such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, and bismuth oxide; sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, and aluminum sulfate; and carbonates such as lithium carbonate, calcium carbonate, and magnesium carbonate.

[0197] The electrode disclosed herein is suitable for use in batteries such as lithium ion secondary batteries, but can also be used in electrochemical devices other than batteries such as electric double layer capacitors.

[0198] <Method for producing positive electrode active material, etc.>

[0199] The positive electrode active material, current collecting foil, negative electrode active material, conductive additive and electrode (collectively referred to as "positive electrode active material, etc.") of the present disclosure can be produced by treating the untreated positive electrode active material, etc. with the electrode material surface treatment agent.

[0200] In addition, the untreated state refers to a state in which the surface treatment agent for the electrode material is not used, and may be a state in which other treatments are applied.

[0201] The above treatment may be any method as long as it is a method of bringing the above electrode material surface treatment agent into contact with the untreated positive electrode active material or the like, and is preferably a method of bringing a solution (treatment solution) containing the above electrode material surface treatment agent into contact.

[0202] The method of contacting with the solution is not particularly limited, and examples thereof include a method of coating the solution on an untreated positive electrode active material or the like, a method of immersing the untreated positive electrode active material or the like in the solution, and the like.

[0203] When the untreated positive electrode active material is immersed in the above solution, the immersion time is preferably 10 hours or less, more preferably 2 hours or less; and preferably 0.01 hours or more, more preferably 0.05 hours or more. The temperature of the above solution during immersion is preferably 100°C or less, more preferably 80°C or less; and preferably 0°C or more, more preferably 5°C or more.

[0204] Furthermore, when the electrode is treated, a battery may be prepared together with an electrolyte solution containing the electrode material surface treatment agent as an additive, so that the electrode is brought into contact with the electrode material surface treatment agent.

[0205] In the solution, the content of the electrode material surface treatment agent is preferably 0.1% by mass or more, more preferably 0.3% by mass or more; and is preferably 10% by mass or less, more preferably 5% by mass or less.

[0206] As the solvent used in the above solution, as long as it is a solvent that can dissolve or disperse the above electrode material surface treatment agent, there is no particular limitation on its type. The solvents described in the above slurry can be used, and examples thereof include ester solvents such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, γ-butyrolactone and propylene carbonate;

[0207] Nitrile solvents such as acetonitrile and propionitrile;

[0208] Ether solvents such as diethyl ether, dipropyl ether, tetrahydrofuran, cyclopentyl methyl ether (CPME) and methyl tert-butyl ether (MT BE);

[0209] and acetone, etc., among which acetonitrile, acetone and tetrahydrofuran are preferred.

[0210] The positive electrode active material after contact with the above solution is preferably freed from the solvent in the above solution. The method for removing the solvent is not particularly limited, and examples thereof include methods of volatilizing the solvent by heat treatment, vacuum drying, etc. The conditions of heat treatment, vacuum drying, etc. can be appropriately adjusted according to the type and amount of the solvent.

[0211] <Battery>

[0212] The battery of the present disclosure includes the above-mentioned electrode (positive electrode and / or negative electrode).

[0213] The components other than the electrodes are not particularly limited, and may include conventional materials such as an electrolyte solution and a separator.

[0214] The battery is preferably a non-aqueous electrolyte battery, and more preferably a lithium ion secondary battery.

[0215] Furthermore, the battery is useful as a large lithium-ion secondary battery used in hybrid vehicles and distributed power sources.

[0216] <Electrolyte>

[0217] The electrolyte solution of the above-mentioned battery contains a solvent and an electrolyte salt.

[0218] The solvent of the electrolytic solution preferably contains at least one selected from the group consisting of carbonate esters and carboxylic acid esters.

[0219] The carbonate ester mentioned above may be a cyclic carbonate ester or a chain carbonate ester.

[0220] The cyclic carbonate may be a non-fluorinated cyclic carbonate or a fluorinated cyclic carbonate.

[0221] Examples of the non-fluorinated cyclic carbonate include non-fluorinated saturated cyclic carbonates, preferably non-fluorinated saturated alkylene carbonates having an alkylene group having 2 to 6 carbon atoms, and more preferably non-fluorinated saturated alkylene carbonates having an alkylene group having 2 to 4 carbon atoms.

[0222] Among them, as the above-mentioned non-fluorinated saturated cyclic carbonate, from the viewpoint of high dielectric constant and suitable viscosity, it is preferably selected from at least one of ethylene carbonate, propylene carbonate, cis-2,3-pentylene carbonate, cis-2,3-butylene carbonate, 2,3-pentylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 1,2-butylene carbonate and butylene carbonate.

[0223] The above-mentioned non-fluorinated saturated cyclic carbonate may be used alone or in combination of two or more in any ratio.

[0224] When the non-fluorinated saturated cyclic carbonate is contained, the content of the non-fluorinated saturated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, and further preferably 15 to 45% by volume based on the solvent.

[0225] The fluorinated cyclic carbonate is a cyclic carbonate having a fluorine atom. A solvent containing a fluorinated cyclic carbonate can be preferably used even at a high voltage.

[0226] The fluorinated cyclic carbonate may be a fluorinated saturated cyclic carbonate or a fluorinated unsaturated cyclic carbonate.

[0227] The fluorinated saturated cyclic carbonate is a saturated cyclic carbonate having a fluorine atom, and specifically, the following general formula (A) can be cited:

[0228] [Chemistry 10]

[0229]

[0230] (Where X 1 ~X 4 Same or different, representing -H, -CH 3 , -C 2 H 5 , -F, a fluoroalkyl group which may have an ether bond, or a fluoroalkoxy group which may have an ether bond. 1 ~X 4 At least one of them is -F, a fluoroalkyl group which may have an ether bond, or a fluoroalkoxy group which may have an ether bond. The above-mentioned fluoroalkyl group refers to -CF 3 , -CF 2 H, -CH 2 F, etc.

[0231] When the electrolyte solution contains the fluorinated saturated cyclic carbonate, the oxidation resistance of the electrolyte solution is improved, and stable and excellent charge and discharge characteristics can be obtained.

[0232] In addition, in this specification, an "ether bond" is a bond represented by -O-.

[0233] From the viewpoint of good dielectric constant and oxidation resistance, X 1 ~X 4 One or two of them are -F, a fluoroalkyl group which may have an ether bond, or a fluoroalkoxy group which may have an ether bond.

[0234] From the perspective of being able to expect a decrease in viscosity at low temperatures, an increase in flash point, and even an improvement in the solubility of the electrolyte salt, X 1 ~X 4 Preferred are -H, -F, a fluoroalkyl group (a), a fluoroalkyl group having an ether bond (b), or a fluoroalkoxy group (c).

[0235] The fluoroalkyl group (a) is a group obtained by replacing at least one hydrogen atom of an alkyl group with a fluorine atom. The number of carbon atoms in the fluoroalkyl group (a) is preferably 1-20, more preferably 1-17, further preferably 1-7, and particularly preferably 1-5.

[0236] If the number of carbon atoms is too large, the low-temperature characteristics may be reduced or the solubility of the electrolyte salt may be reduced. If the number of carbon atoms is too small, the solubility of the electrolyte salt may be reduced, the discharge efficiency may be reduced, or even the viscosity may be increased.

[0237] In the above fluoroalkyl group (a), examples of the fluoroalkyl group having 1 carbon atom include CFH 2-、CF 2 H-, CF 3 -. In particular, CF is preferred in terms of high temperature storage characteristics. 2 H- or CF 3 -, most preferably CF 3 -.

[0238] Among the fluoroalkyl groups (a), the group having 2 or more carbon atoms preferably includes the following general formula (a-1) from the viewpoint of good solubility of the electrolyte salt:

[0239] R a1 -R a2 -(a-1)

[0240] (Where R a1 is an alkyl group having 1 or more carbon atoms which may have a fluorine atom; R a2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom; wherein R a1 and R a2 At least one of them has a fluorine atom).

[0241] It should be noted that R a1 and R a2 It may also contain atoms other than carbon atoms, hydrogen atoms and fluorine atoms.

[0242] R a1 It is an alkyl group having 1 or more carbon atoms which may have a fluorine atom. a1 , preferably a linear or branched alkyl group having 1 to 16 carbon atoms. a1 The number of carbon atoms in the moiety is more preferably 1-6, and even more preferably 1-3.

[0243] As R a1 Specifically, as a linear or branched alkyl group, CH 3 -、CH 3 CH 2 -、CH 3 CH 2 CH 2 -、CH 3 CH 2 CH 2 CH 2 -、

[0244] [Chemistry 11]

[0245]

[0246] wait.

[0247] In addition, in R a1In the case of a linear alkyl group having a fluorine atom, examples include: CF 3 -、CF 3 CH 2 -、CF 3 CF 2 -、CF 3 CH 2 CH 2 -、CF 3 CF 2 CH 2 -、CF 3 CF 2 CF 2 -、CF 3 CH 2 CF 2 -、CF 3 CH 2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 -、CF 3 CH 2 CF 2 CH 2 -、CF 3 CF 2 CF 2 CH 2 -、CF 3 CF 2 CF 2 CF 2 -、CF 3 CF 2 CH 2 CF 2 -、CF 3 CH 2 CH 2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 CH 2 -、CF 3 CH 2 CF 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CH 2 CH 2 -、CF 3 CF 2CF 2 CF 2 CH 2 -、CF 3 CF 2 CH 2 CF 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CF 2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CF 2 CH 2 CH 2 -、HCF 2 -、HCF 2 CH 2 -、HCF 2 CF 2 -、HCF 2 CH 2 CH 2 -、HCF 2 CF 2 CH 2 -、HCF 2 CH 2 CF 2 -、HCF 2 CF 2 CH 2 CH 2 -、HCF 2 CH 2 CF 2 CH 2 -、HCF 2 CF 2 CF 2 CF 2 -、HCF 2 CF 2 CH 2 CH 2 CH 2 -、HCF 2 CH 2 CF 2 CH 2 CH 2 -、HCF 2 CF2 CF 2 CF 2 CH 2 -、HCF 2 CF 2 CF 2 CF 2 CH 2 CH 2 -、FCH 2 -、FCH 2 CH 2 -、FCH 2 CF 2 -、FCH 2 CF 2 CH 2 -、FCH 2 CF 2 CF 2 -、CH 3 CF 2 CH 2 -、CH 3 CF 2 CF 2 -、CH 3 CF 2 CH 2 CF 2 -、CH 3 CF 2 CF 2 CF 2 -、CH 3 C H 2 CF 2 CF 2 -、CH 3 CF 2 CH 2 CF 2 CH 2 -、CH 3 CF 2 CF 2 CF 2 CH 2 -、CH 3 CF 2 CF 2 CH 2 CH 2 -、CH 3 CH 2 CF 2 CF 2 CH 2 -、CH 3 CF 2 CH 2 CF 2 CH 2 CH2 -、CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, HCFClCF 2 CH 2 -, HCF 2 CFClCH 2 -, HCF 2 CFClCF 2 CFClCH 2 -, HCFClCF 2 CFCl CF 2 CH 2 -wait.

[0248] In addition, in R a1 In the case of a branched alkyl group having a fluorine atom, preferably:

[0249] [Chemistry 12]

[0250]

[0251] [Chemistry 13]

[0252]

[0253] Etc. Among them, if there is CH 3 -、CF 3 - Such a branched chain tends to increase the viscosity, and therefore the number thereof is preferably small (1) or zero.

[0254] R a2 It is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom. a2 It may be linear or branched. Some examples of the minimum structural unit constituting such a linear or branched alkylene group are shown below. a2 It is composed of them individually or in combination.

[0255] (i) The smallest structural unit of a straight chain:

[0256] -CH 2 -、-CHF-、-CF 2 -、-CHCl-、-CFCl-、-CCl 2 -

[0257] (ii) The smallest structural unit of a branched chain:

[0258] [Chemistry 14]

[0259]

[0260] Among the above examples, it is preferred that the structure be composed of a structural unit containing no Cl, since the structure does not cause a dehydrochlorination reaction by a base and is more stable.

[0261] In R a2 In the case of a linear chain, it is composed only of the above-mentioned linear minimum structural unit, among which -CH 2 -、-CH 2 CH 2 -or-CF 2 From the viewpoint of further improving the solubility of the electrolyte salt, -CH 2 -or-CH 2 CH 2 -.

[0262] In R a2 In the case of a branched chain, it is a group containing at least one of the above-mentioned branched chain minimum structural units, and the general formula can be preferably exemplified as follows: -(CX a X b )-(X a H, F, CH 3 or CF 3 ;X b CH 3 or CF 3 Among them, in X b For CF 3 In the case of X a H or CH 3 These units can further improve the solubility of the electrolyte salt.

[0263] Preferred fluoroalkyl groups (a) include, for example, CF 3 CF 2 -, HCF 2 CF 2 -、H 2 CFCF 2 -、CH 3 CF 2 -、CF 3 CHF-、CH 3 CF 2 -、CF 3 CF 2 CF 2 -, HCF 2 CF 2 CF 2 -、H 2 CFCF 2 CF 2 -、CH 3 CF2 CF 2 -、

[0264] [Chemistry 15]

[0265]

[0266] [Chemistry 16]

[0267]

[0268] wait.

[0269] The above-mentioned fluoroalkyl group (b) having an ether bond is a group obtained by replacing at least one of the hydrogen atoms possessed by the alkyl group having an ether bond with a fluorine atom. The number of carbon atoms of the above-mentioned fluoroalkyl group (b) having an ether bond is preferably 2 to 17. If the number of carbon atoms is too large, the viscosity of the above-mentioned fluorinated saturated cyclic carbonate becomes higher; in addition, due to the increase in the number of fluorinated groups, it is sometimes observed that the solubility of the electrolyte salt caused by the decrease in the dielectric constant and the compatibility with other solvents are reduced. From this viewpoint, the number of carbon atoms of the above-mentioned fluoroalkyl group (b) having an ether bond is more preferably 2 to 10, and further preferably 2 to 7.

[0270] The alkylene group constituting the ether portion of the fluoroalkyl group (b) having an ether bond may be a linear or branched alkylene group. Some examples of the minimum structural unit constituting such a linear or branched alkylene group are shown below.

[0271] (i) The smallest structural unit of a straight chain:

[0272] -CH 2 -、-CHF-、-CF 2 -、-CHCl-、-CFCl-、-CCl 2 -

[0273] (ii) The smallest structural unit of a branched chain:

[0274] [Chemistry 17]

[0275]

[0276] The alkylene group may be composed of these minimum structural units alone, or may be composed of linear (i) groups, branched (ii) groups, or a combination of a linear (i) group and a branched (ii) group. Preferred specific examples are described below.

[0277] Among the above examples, it is preferred that the structure be composed of a structural unit containing no Cl, since the structure does not cause a dehydrochlorination reaction by a base and is more stable.

[0278] As further preferred fluorinated alkyl groups (b) having an ether bond, there can be mentioned general formula (b-1):

[0279] R 3 -(OR 4 ) n1 -(b-1)

[0280] (Where R 3 is an alkyl group which may have a fluorine atom and preferably has 1 to 6 carbon atoms; R 4 is an alkylene group which may have a fluorine atom and preferably has 1 to 4 carbon atoms; n1 is an integer of 1 to 3; wherein R 3 and R 4 At least one of which has a fluorine atom).

[0281] As R 3 and R 4 The following groups can be exemplified, and these groups can be appropriately combined to form the fluorinated alkyl group (b) having an ether bond represented by the above general formula (b-1), but the group is not limited to these groups.

[0282] (1) As R 3 , preferably the general formula: X c 3 C-(R 5 ) n2 -(3 X c Same or different, both H or F; R 5 is an alkylene group having 1 to 5 carbon atoms and optionally having a fluorine atom; n2 is an alkyl group represented by 0 or 1).

[0283] When n2 is 0, as R 3 , for example CH 3 -、CF 3 -, HCF 2 - and H 2 CF-.

[0284] As a specific example when n2 is 1, R 3 It is a straight chain group, and examples thereof include: CF 3 CH 2 -、CF 3 CF 2 -、CF 3 CH 2 CH 2 -、CF 3 CF 2 CH 2 -、CF 3 CF 2 CF 2 -、CF 3 CH2 CF 2 -、CF 3 CH 2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 -、CF 3 CH 2 CF 2 CH 2 -、CF 3 CF 2 CF 2 CH 2 -、CF 3 CF 2 CF 2 CF 2 -、CF 3 CF 2 CH 2 CF 2 -、CF 3 CH 2 CH 2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 CH 2 -、CF 3 CH 2 CF 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CF 2 CH 2 -、CF 3 CF 2 CH 2 CF 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CF2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CF 2 CH 2 CH 2 -、HCF 2 CH 2 -、HCF 2 CF 2 -、HCF 2 CH 2 CH 2 -、HCF 2 CF 2 CH 2 -、HCF 2 CH 2 CF 2 -、HCF 2 CF 2 CH 2 CH 2 -、HCF 2 CH 2 CF 2 CH 2 -、HCF 2 CF 2 CF 2 CF 2 -、HCF 2 CF 2 C H 2 CH 2 CH 2 -、HCF 2 CH 2 CF 2 CH 2 CH 2 -、HCF 2 CF 2 CF 2 CF 2 CH 2 -、HCF 2 CF 2 CF 2 CF 2 CH 2 CH 2 -、FCH 2 CH 2 -、FCH 2 CF 2 -、FCH 2 CF 2 CH 2 -、CH 3 CF2 -、CH 3 CH 2 -、CH 3 CF 2 CH 2 -、CH 3 CF 2 CF 2 -、CH 3 CH 2 CH 2 -、CH 3 CF 2 CH 2 CF 2 -、CH 3 CF 2 CF 2 CF 2 -、C H 3 CH 2 CF 2 CF 2 -、CH 3 CH 2 CH 2 CH 2 -、CH 3 CF 2 CH 2 CF 2 CH 2 -、CH 3 CF 2 CF 2 CF 2 CH 2 -、CH 3 CF 2 CF 2 CH 2 CH 2 -、CH 3 CH 2 CF 2 CF 2 CH 2 -、CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -、CH 3 CH 2 CF 2 CF 2 CH 2 CH 2 -、CH 3 CF 2 CH 2 CF 2 CH 2CH 2 -wait.

[0285] As n2 is 1, and R 3 The branched group includes:

[0286] [Chemistry 18]

[0287]

[0288] wait.

[0289] Among them, if there is CH 3 -、CF 3 - Such a branched chain tends to increase the viscosity, so R is more preferred 3 It is a straight chain group.

[0290] (2) In the above general formula (b-1), -(OR 4 ) n1 -, n1 is an integer of 1 to 3, preferably 1 or 2. It should be noted that when n1 = 2 or 3, R 4 Can be the same or different.

[0291] As R 4 Preferred specific examples include the following linear or branched groups.

[0292] Examples of the linear group include -CH 2 -、-CHF-、-CF 2 -、-CH 2 CH 2 -、-CF 2 CH 2 -、-CF 2 CF 2 -、-CH 2 CF 2 -、-CH 2 CH 2 CH 2 -、-CH 2 CH 2 CF 2 -、-CH 2 CF 2 CH 2 -、-CH 2 CF 2 CF 2 -、-CF 2 CH 2 CH 2 -、-CF 2 CF 2 CH 2 -、-CF 2 CH2 CF 2 -、-CF 2 CF 2 CF 2 -wait.

[0293] Examples of the branched group include:

[0294] [Chemistry 19]

[0295]

[0296] wait.

[0297] The fluoroalkoxy group (c) is a group in which at least one of the hydrogen atoms in an alkoxy group is replaced by a fluorine atom. The fluoroalkoxy group (c) preferably has 1 to 17 carbon atoms, and more preferably has 1 to 6 carbon atoms.

[0298] As the fluoroalkoxy group (c), the general formula: X d 3 C-(R 6 ) n3 -O-(3 X d Same or different, both H or F; R 6 Preferably, it is an alkylene group having 1 to 5 carbon atoms and optionally having a fluorine atom; n3 is 0 or 1; wherein 3 X d At least one of them contains a fluorine atom).

[0299] Specific examples of the fluoroalkoxy group (c) include: 1 The exemplified fluoroalkoxy group is a group in which an oxygen atom is bonded to the terminal of an alkyl group.

[0300] The fluorine content of the fluoroalkyl (a), the fluoroalkyl (b) and the fluoroalkoxy (c) in the above-mentioned fluorinated saturated cyclic carbonate is preferably more than 10 mass %. If the fluorine content is too low, then the effect of the viscosity under the low temperature, the effect of the rising flash point may not be fully obtained. From this viewpoint, the above-mentioned fluorine content is more preferably more than 12 mass %, more preferably more than 15 mass %. The upper limit is usually 76 mass %.

[0301] The fluorine content of the fluoroalkyl group (a), the fluoroalkyl group having an ether bond (b), and the fluoroalkoxy group (c) is a value calculated according to {(number of fluorine atoms×19) / formula weight of each group}×100(%) based on the structural formula of each group.

[0302] In view of good dielectric constant and oxidation resistance, the fluorine content of the fluorinated saturated cyclic carbonate as a whole is preferably 10% by mass or more, more preferably 15% by mass or more, and the upper limit is usually 76% by mass.

[0303] The fluorine content of the fluorinated saturated cyclic carbonate is a value calculated according to {(number of fluorine atoms×19) / molecular weight of fluorinated saturated cyclic carbonate}×100(%) based on the structural formula of the fluorinated saturated cyclic carbonate.

[0304] Specific examples of the fluorinated saturated cyclic carbonate include the following.

[0305] As X 1 ~X 4 Specific examples of the fluorinated saturated cyclic carbonate wherein at least one of the -F groups is:

[0306] [Chemistry 20]

[0307]

[0308] Etc. These compounds have high withstand voltage and good solubility of electrolyte salt.

[0309] In addition, you can also use

[0310] [Chemistry 21]

[0311]

[0312] wait.

[0313] As X 1 ~X 4 Specific examples of fluorinated saturated cyclic carbonates in which at least one of the fluorinated alkyl groups (a) is a fluorinated alkyl group and all the others are -H include:

[0314] [Chemistry 22]

[0315]

[0316] [Chemistry 23]

[0317]

[0318] [Chemistry 24]

[0319]

[0320] wait.

[0321] As X 1 ~X 4Specific examples of the fluorinated saturated cyclic carbonate in which at least one of the fluorinated alkyl groups (b) or the fluorinated alkoxy group (c) having an ether bond and the rest are all -H include:

[0322] [Chemistry 25]

[0323]

[0324] [Chemistry 26]

[0325]

[0326] [Chemistry 27]

[0327]

[0328] [Chemistry 28]

[0329]

[0330] [Chemistry 29]

[0331]

[0332] [Chemistry 30]

[0333]

[0334] wait.

[0335] Among them, the fluorinated saturated cyclic carbonate is preferably any one of the following compounds.

[0336] [Chemistry 31]

[0337]

[0338] [Chemistry 32]

[0339]

[0340] Examples of the fluorinated saturated cyclic carbonates include trans-4,5-difluoro-1,3-dioxolane-2-one, 5-(1,1-difluoroethyl)-4,4-difluoro-1,3-dioxolane-2-one, 4-methylene-1,3-dioxolane-2-one, 4-methyl-5-trifluoromethyl-1,3-dioxolane-2-one, 4-ethyl-5-fluoro-1,3-dioxolane-2-one, 4-ethyl-5,5-difluoro-1 ,3-dioxolane-2-one, 4-ethyl-4,5-difluoro-1,3-dioxolane-2-one, 4-ethyl-4,5,5-trifluoro-1,3-dioxolane-2-one, 4,4-difluoro-5-methyl-1,3-dioxolane-2-one, 4-fluoro-5-methyl-1,3-dioxolane-2-one, 4-fluoro-5-trifluoromethyl-1,3-dioxolane-2-one, 4,4-difluoro-1,3-dioxolane-2-one, etc.

[0341] Among these, the fluorinated saturated cyclic carbonate is more preferably fluorinated ethylene carbonate, difluoroethylene carbonate, trifluoromethylethylene carbonate (3,3,3-trifluoropropylene carbonate), or 2,2,3,3,3-pentafluoropropylethylene carbonate.

[0342] The above-mentioned fluorinated unsaturated cyclic carbonate is a cyclic carbonate having an unsaturated bond and a fluorine atom, and is preferably a fluorinated ethylene carbonate derivative obtained by being substituted with a substituent having an aromatic ring or a carbon-carbon double bond. Specifically, it can be mentioned: 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-4-phenylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4-fluoro-4-vinylethylene carbonate, 4-fluoro-4,5-diallylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-diallylethylene carbonate, etc.

[0343] The above-mentioned fluorinated cyclic carbonate may be used alone or in combination of two or more in any ratio.

[0344] When the fluorinated cyclic carbonate is contained, the content of the fluorinated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, and further preferably 15 to 45% by volume based on the volume of the solvent.

[0345] The above-mentioned chain carbonate may be a non-fluorinated chain carbonate or a fluorinated chain carbonate.

[0346] Examples of the non-fluorinated chain carbonate include: CH3 OCOOCH 3 (dimethyl carbonate: DMC), CH 3 CH 2 OCOOCH 2 CH 3 (Diethyl carbonate: DEC), CH 3 CH 2 OCOOCH 3 (ethyl methyl carbonate: EMC), CH 3 OCOOCH 2 CH 2 CH 3 The hydrocarbon chain carbonates include methyl propyl carbonate, methyl butyl carbonate, ethyl propyl carbonate, ethyl butyl carbonate, dipropyl carbonate, dibutyl carbonate, methyl isopropyl carbonate, methyl-2-phenylphenyl carbonate, phenyl-2-phenylphenyl carbonate, trans-2,3-pentylene carbonate, trans-2,3-butylene carbonate, ethyl phenyl carbonate, etc. Among them, at least one selected from ethyl methyl carbonate, diethyl carbonate and dimethyl carbonate is preferred.

[0347] The non-fluorinated chain carbonate esters may be used alone or in combination of two or more in any ratio.

[0348] When the non-fluorinated linear carbonate is contained, the content of the non-fluorinated linear carbonate is preferably 10 to 90% by volume, more preferably 40 to 85% by volume, and further preferably 50 to 80% by volume based on the solvent.

[0349] The fluorinated chain carbonate is a chain carbonate having a fluorine atom. A solvent containing a fluorinated chain carbonate can be preferably used even at a high voltage.

[0350] Examples of the fluorinated chain carbonate include general formula (B):

[0351] R a OCOOR 7 (B)

[0352] (Where Rf a is a fluoroalkyl group having 1 to 7 carbon atoms, R 7 It is an alkyl group having 1 to 7 carbon atoms and optionally containing a fluorine atom. ) is a compound represented by

[0353] R a is a fluoroalkyl group having 1 to 7 carbon atoms, R 7 It is an alkyl group having 1 to 7 carbon atoms and optionally containing a fluorine atom.

[0354] The fluorinated alkyl group is a group in which at least one of the hydrogen atoms in the alkyl group is replaced by a fluorine atom.7 In the case of an alkyl group containing a fluorine atom, it becomes a fluorinated alkyl group.

[0355] From the perspective of low viscosity, Rf a and R 7 The number of carbon atoms in is preferably 1-7, more preferably 1-2.

[0356] If the number of carbon atoms is too large, it may sometimes cause problems such as reduced low-temperature characteristics or reduced solubility of the electrolyte salt; if the number of carbon atoms is too small, it may sometimes cause reduced solubility of the electrolyte salt, reduced discharge efficiency, or even increased viscosity.

[0357] Examples of the fluoroalkyl group having 1 carbon atom include CFH 2 -、CF 2 H-, CF 3 - etc. In particular, CFH is preferred in terms of high temperature storage properties. 2 - or CF 3 -.

[0358] As the fluorinated alkyl group having 2 or more carbon atoms, the following general formula (d-1) can be preferably exemplified from the viewpoint of good solubility of the electrolyte salt:

[0359] R d1 -R d2 -(d-1)

[0360] (Where R d1 is an alkyl group having 1 or more carbon atoms which may have a fluorine atom; R d2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom; wherein R d1 and R d2 At least one of them has a fluorine atom).

[0361] It should be noted that R d1 and R d2 It may also contain atoms other than carbon atoms, hydrogen atoms and fluorine atoms.

[0362] R d1 It is an alkyl group having 1 or more carbon atoms which may have a fluorine atom. d1 , preferably a linear or branched alkyl group having 1 to 6 carbon atoms. d1 The number of carbon atoms is more preferably 1-3.

[0363] As R d1 Specifically, as a linear or branched alkyl group, CH 3 -、CF 3 -、CH 3 CH 2-、CH 3 CH 2 CH 2 -、CH 3 CH 2 CH 2 CH 2 -、

[0364] [Chemistry 33]

[0365]

[0366] wait.

[0367] In addition, in R d1 In the case of a linear alkyl group having a fluorine atom, examples include: CF 3 -、CF 3 CH 2 -、CF 3 CF 2 -、CF 3 CH 2 CH 2 -、CF 3 CF 2 CH 2 -、CF 3 CF 2 CF 2 -、CF 3 CH 2 CF 2 -、CF 3 CH 2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 -、CF 3 CH 2 CF 2 CH 2 -、CF 3 CF 2 CF 2 CH 2 -、CF 3 CF 2 CF 2 CF 2 -、CF 3 CF 2 CH 2 CF 2 -、CF 3 CH 2 CH 2 CH 2 CH 2 -、CF3 CF 2 CH 2 CH 2 CH 2 -、CF 3 CH 2 CF 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CF 2 CH 2 -、CF 3 CF 2 CH 2 CF 2 CH 2 -、CF 3 CF 2 CH 2 CH 2 CH 2 CH 2 -、CF 3 CF 2 CF 2 CF 2 CH 2 CH 2 -、CF 3 CF 2 CH 2 CF 2 CH 2 CH 2 -、HCF 2 -、HCF 2 CH 2 -、HCF 2 CF 2 -、HCF 2 CH 2 CH 2 -、HCF 2 CF 2 CH 2 -、HCF 2 CH 2 CF 2 -、HCF 2 CF 2 CH 2 CH 2 -、HCF 2 CH 2 CF 2 CH2 -、HCF 2 CF 2 CF 2 CF 2 -、HCF 2 CF 2 CH 2 CH 2 CH 2 -、HCF 2 CH 2 CF 2 CH 2 CH 2 -、HCF 2 CF 2 CF 2 CF 2 CH 2 -、HCF 2 CF 2 CF 2 CF 2 CH 2 CH 2 -、FCH 2 -、FCH 2 CH 2 -、FCH 2 CF 2 -、FCH 2 CF 2 CH 2 -、FCH 2 CF 2 CF 2 -、CH 3 CF 2 CH 2 -、CH 3 CF 2 CF 2 -、CH 3 CF 2 CH 2 CF 2 -、CH 3 CF 2 CF 2 CF 2 -、CH 3 C H 2 CF 2 CF 2 -、CH 3 CF 2 CH 2 CF 2 CH 2 -、CH 3 CF 2 CF 2 CF 2CH 2 -、CH 3 CF 2 CF 2 CH 2 CH 2 -、CH 3 CH 2 CF 2 CF 2 CH 2 -、CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -、CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, HCFClCF 2 CH 2 -, HCF 2 CFClCH 2 -, HCF 2 CFClCF 2 CFClCH 2 -, HCFClCF 2 CFCl CF 2 CH 2 -wait.

[0368] In addition, in R d1 In the case of a branched alkyl group having a fluorine atom, preferably:

[0369] [Chemistry 34]

[0370]

[0371] [Chemistry 35]

[0372]

[0373] Etc. Among them, if there is CH 3 -、CF 3 - Such a branched chain tends to increase the viscosity, and therefore the number thereof is preferably small (1) or zero.

[0374] R d2 It is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom. d2 It may be linear or branched. An example of the minimum structural unit constituting such a linear or branched alkylene group is shown below. d2 It is composed of them individually or in combination.

[0375] (i) The smallest structural unit of a straight chain:

[0376] -CH 2 -、-CHF-、-CF 2 -、-CHCl-、-CFCl-、-CCl 2 -

[0377] (ii) The smallest structural unit of a branched chain:

[0378] [Chemistry 36]

[0379]

[0380] Among the above examples, it is preferred that the structure be composed of a structural unit containing no Cl, since the structure does not cause a dehydrochlorination reaction by a base and is more stable.

[0381] In R d2 In the case of a linear group, it is a group consisting only of the above-mentioned linear minimum structural unit, among which -CH 2 -、-CH 2 CH 2 -or-CF 2 From the viewpoint of further improving the solubility of the electrolyte salt, -CH 2 -or-CH 2 CH 2 -.

[0382] In R d2 In the case of a branched chain, it is a group containing at least one of the above-mentioned branched chain minimum structural units, and the general formula can be preferably exemplified as follows: -(CX a X b )-(X a H, F, CH 3 or CF 3 ;X b CH 3 or CF 3 Among them, in X b For CF 3 In the case of X a H or CH 3 These groups can further improve the solubility of the electrolyte salt.

[0383] Preferred fluoroalkyl groups include, for example, CF 3 CF 2 -, HCF 2 CF 2 -、H 2 CFCF2 -、CH 3 CF 2 -、CF 3 CH 2 -、CF 3 CF 2 CF 2 -, HCF 2 CF 2 CF 2 -、H 2 CFCF 2 CF 2 -、CH 3 CF 2 CF 2 -、

[0384] [Chemistry 37]

[0385]

[0386] [Chemistry 38]

[0387]

[0388] wait.

[0389] Among them, as Rf 2 and R 7 A fluoroalkyl group, preferably CF 3 -、CF 3 CF 2 -、(CF 3 ) 2 CH-、CF 3 CH 2 -、C 2 F 5 CH 2 -、CF 3 CF 2 CH 2 -, HCF 2 CF 2 CH 2 -、CF 3 CFHCF 2 CH 2 -、CFH 2 -、CF 2 H-, CF is more preferred from the viewpoint of high flame retardancy, good rate characteristics, and good oxidation resistance 3 CH 2 -、CF 3 CF 2 CH 2 -, HCF 2 CF 2 CH 2-、CFH 2 -、CF 2 H-.

[0390] In R 7 In the case of an alkyl group not containing a fluorine atom, it is an alkyl group having 1 to 7 carbon atoms. 7 The number of carbon atoms is preferably 1-4, more preferably 1-3.

[0391] Examples of the alkyl group not containing a fluorine atom include CH 3 -、CH 3 CH 2 -、(CH 3 ) 2 CH-、C 3 H 7 Among them, CH 3 -、CH 3 CH 2 -.

[0392] The fluorine content of above-mentioned fluorinated linear carbonate is preferably 15~70 mass %.If fluorine content is in above-mentioned scope, then can keep the compatibility with solvent, the solubility of salt.Above-mentioned fluorine content is more preferably more than 20 mass %, further preferably more than 30 mass %, particularly preferably more than 35 mass %, more preferably below 60 mass %, further preferably below 50 mass %.

[0393] It should be noted that in the present disclosure, the fluorine content is based on the structural formula of the above-mentioned fluorinated chain carbonate.

[0394] {(number of fluorine atoms × 19) / molecular weight of fluorinated chain carbonate} × 100 (%)

[0395] Calculated value.

[0396] As the fluorinated chain carbonate, any of the following compounds is preferred from the viewpoint of low viscosity.

[0397] [Chemistry 39]

[0398]

[0399] As the fluorinated chain carbonate, methyl 2,2,2-trifluoroethyl carbonate (F 3 CH 2 C OC(=O)OCH 3 ).

[0400] The above-mentioned fluorinated chain carbonates may be used alone or in combination of two or more in any ratio.

[0401] When the non-fluorinated chain carbonate is contained, the content of the fluorinated chain carbonate is preferably 10 to 90% by volume, more preferably 40 to 85% by volume, and even more preferably 50 to 80% by volume based on the solvent.

[0402] The carboxylic acid ester may be a cyclic carboxylic acid ester or a chain carboxylic acid ester.

[0403] The cyclic carboxylic acid ester may be a non-fluorinated cyclic carboxylic acid ester or a fluorinated cyclic carboxylic acid ester.

[0404] Examples of the non-fluorinated cyclic carboxylic acid ester include non-fluorinated saturated cyclic carboxylic acid esters, and non-fluorinated saturated cyclic carboxylic acid esters having an alkylene group having 2 to 4 carbon atoms are preferred.

[0405] Specific examples of the non-fluorinated saturated cyclic carboxylic acid ester having an alkylene group having 2 to 4 carbon atoms include β-propiolactone, γ-butyrolactone, ε-caprolactone, Δ-valerolactone, and α-methyl-γ-butyrolactone. Among them, γ-butyrolactone and Δ-valerolactone are particularly preferred from the viewpoint of increasing the degree of lithium ion dissociation and improving the load characteristics.

[0406] The above-mentioned non-fluorinated saturated cyclic carboxylic acid ester may be used alone or in combination of two or more in any ratio.

[0407] When the non-fluorinated saturated cyclic carboxylic acid ester is contained, the content of the non-fluorinated saturated cyclic carboxylic acid ester is preferably 0 to 90% by volume, more preferably 0.001 to 90% by volume, further preferably 1 to 60% by volume, particularly preferably 5 to 40% by volume, based on the solvent.

[0408] The chain carboxylate may be a non-fluorinated chain carboxylate or a fluorinated chain carboxylate. When the solvent contains the chain carboxylate, an increase in resistance of the electrolyte after high-temperature storage can be further suppressed.

[0409] Examples of the non-fluorinated chain carboxylic acid ester include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, tert-butyl propionate, tert-butyl butyrate, sec-butyl propionate, sec-butyl butyrate, n-butyl butyrate, methyl pyrophosphate, ethyl pyrophosphate, tert-butyl formate, tert-butyl acetate, sec-butyl formate, sec-butyl acetate, n-hexyl pivalate, n-propyl formate, n-propyl acetate, methyl ethyl 2-(diethylphosphoryl)acetate, isopropyl propionate, isopropyl acetate, ethyl formate, 2-propynylethyl oxalate, isopropyl formate, isopropyl butyrate, isobutyl formate, isobutyl propionate, isobutyl butyrate, isobutyl acetate, and the like.

[0410] Among them, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate are preferred, and ethyl propionate and propyl propionate are particularly preferred.

[0411] The above-mentioned non-fluorinated chain carboxylic acid ester may be used alone or in combination of two or more in any ratio.

[0412] When the non-fluorinated chain carboxylic acid ester is contained, the content of the non-fluorinated chain carboxylic acid ester is preferably 0 to 90% by volume, more preferably 0.001 to 90% by volume, further preferably 1 to 60% by volume, particularly preferably 5 to 40% by volume, based on the solvent.

[0413] The fluorinated chain carboxylic acid ester is a chain carboxylic acid ester having a fluorine atom. A solvent containing a fluorinated chain carboxylic acid ester can be preferably used even at a high voltage.

[0414] As the fluorinated chain carboxylic acid ester, the following general formula is preferred from the viewpoint of good compatibility with other solvents and good oxidation resistance:

[0415] R 31 COOR 32

[0416] (Where R 31 and R 32 are independently an alkyl group having 1 to 4 carbon atoms and optionally containing a fluorine atom, R 31 and R 32 At least one of them contains a fluorine atom. ) is a fluorinated chain carboxylic acid ester.

[0417] As R 31 and R 32 For example, methyl (-CH 3 ), ethyl (-CH 2 CH 3) propyl (-CH 2 CH 2 CH 3 ) isopropyl (-CH(CH 3 ) 2 ) n-butyl (-CH 2 CH 2 CH 2 CH 3 ) tert-butyl (-C(CH 3 ) 3 ) and other unfluorinated alkyl groups; -CF 3 、-CF 2 H、-CFH 2 、-CF 2 CF 3 、-CF 2 CF 2 H、-CF 2 CFH 2 、-C H 2 CF 3 、-CH 2 CF 2 H、-CH 2 CFH 2 、-CF 2 CF 2 CF 3 、-CF 2 CF 2 CF 2 H、-CF 2 CF 2 CFH 2 、-CH 2 CF 2 CF 3 、-CH 2 CF 2 CF 2 H、-CH 2 CF 2 CFH 2 、-CH 2 CH 2 CF 3 、-CH 2 CH 2 CF 2 H、-CH 2 CH 2 CFH 2 、-CF(CF 3 ) 2 、-CF(CF 2 H) 2 、-CF(CFH 2 ) 2 、-CH(CF3 ) 2 、-CH(CF 2 H) 2 、-CH(CFH 2 ) 2 、-CF(OCH 3 )CF 3 、-CF 2 CF 2 CF 2 CF 3 、-CF 2 CF 2 CF 2 CF 2 H、-CF 2 C F 2 CF 2 CFH 2 、-CH 2 CF 2 CF 2 CF 3 、-CH 2 CF 2 CF 2 CF 2 H、-CH 2 CF 2 CF 2 CFH 2 、-CH 2 C H 2 CF 2 CF 3 、-CH 2 CH 2 CF 2 CF 2 H、-CH 2 CH 2 CF 2 CFH 2 、-CH 2 CH 2 CH 2 CF 3 、-CH 2 CH 2 CH 2 CF 2 H、-CH 2 CH 2 CH 2 CFH 2 、-CF(CF 3 )CF 2 CF 3 、-CF(CF 2 H)CF 2 CF 3 、-CF(CFH2 )CF 2 CF 3 、-CF(CF 3 )CF 2 CF 2 H、-CF(CF 3 )CF 2 CFH 2 、-CF(CF 3 )CH 2 CF 3 、-C F(CF 3 )CH 2 CF 2 H、-CF(CF 3 )CH 2 CFH 2 、-CH(CF 3 )CF 2 CF 3 、-CH(CF 2 H)CF 2 CF 3 、-CH(CFH 2 )CF 2 CF 3 、-CH(CF 3 )CF 2 CF 2 H、-CH(CF 3 )CF 2 CFH 2 、-CH(CF 3 )CH 2 CF 3 、-CH(CF 3 )CH 2 CF 2 H、-CH(CF 3 )CH 2 CFH 2 、-CF 2 CF(CF 3 )CF 3 、-CF 2 CF(CF 2 H)CF 3 、-CF 2 CF(CFH 2 )CF 3 、-CF 2 CF(CF 3 )CF 2 H、-CF 2 CF(CF 3 )CFH 2 、-CH 2 CF(CF3 )CF 3 、-CH 2 CF(CF 2 H)CF 3 、-CH 2 CF(CFH 2 )CF 3 、-CH 2 CF(CF 3 )CF 2 H, -CH 2 CF(CF 3 )CFH 2 、-CH 2 CH(CF 3 )CF 3 、-CH 2 CH(CF 2 H)CF 3 、-CH 2 CH(CFH 2 )CF 3 、-CH 2 CH(CF 3 )CF 2 H, -CH 2 CH(CF 3 )CFH 2 , -CF 2 CH(CF 3 )CF 3 , -CF 2 CH(CF 2 H)CF 3 , -CF 2 CH(CFH 2 )CF 3 , -CF 2 CH(CF 3 )CF 2 H, -CF 2 CH(CF 3 )CFH 2 ,-C(CF 3 ) 3 ,-C(CF 2 H) 3 ,-C(CFH 2 ) 3 Among them, methyl, ethyl, -CF 3 , -CF 2 H, -CF 2 CF 3 、-CH 2 CF 3、-CH 2 CF 2 H, -CH 2 CFH 2 、-CH 2 CH 2 CF 3 、-CH 2 CF 2 CF 3 、-CH 2 CF 2 CF 2 H, -CH 2 CF 2 CFH 2 .

[0418] Specific examples of the fluorinated chain carboxylic acid ester include: CF 3 CH 2 C(=O)OCH 3 (3,3,3-trifluoropropionic acid methyl ester), HCF 2 C(=O)OCH 3 (methyl difluoroacetate), HCF 2 C(=O)OC 2 H 5 (ethyl difluoroacetate), CF 3 C(=O)OCH 2 CH 2 CF 3 CF 3 C(=O)OCH 2 C 2 F 5 CF 3 C(=O)OCH 2 CF 2 CF 2 H(2,2,3,3-tetrafluoropropyl trifluoroacetate), CF 3 C(=O)OCH 2 CF 3 CF 3 C(=O)OCH(CF 3 ) 2 , ethyl pentafluorobutyrate, methyl pentafluoropropionate, ethyl pentafluoropropionate, methyl heptafluoroisobutyrate, isopropyl trifluorobutyrate, ethyl trifluorobutyrate, tert-butyl trifluoroacetate, n-butyl trifluoroacetate, methyl tetrafluoro-2-(methoxy)propionate, 2,2-difluoroethyl acetate, 2,2,3,3-tetrafluoropropyl acetate, CH 3 C(=O)OCH 2 CF 3One or more of (2,2,2-trifluoroethyl acetate), 2,2,3,3,4,4,4-heptafluorobutyl acetate, methyl 4,4,4-trifluorobutyrate, ethyl 4,4,4-trifluorobutyrate, ethyl 3,3,3-trifluoropropionate, 3,3,3-trifluoropropyl 3,3,3-trifluoropropionate, ethyl 3-(trifluoromethyl)butyrate, methyl 2,3,3,3-tetrafluoropropionate, butyl 2,2-difluoroacetate, methyl 2,2,3,3-tetrafluoropropionate, methyl 2-(trifluoromethyl)-3,3,3-trifluoropropionate, and methyl heptafluorobutyrate.

[0419] Among them, from the viewpoint of good compatibility with other solvents and good rate characteristics, CF 3 CH 2 C(=O)OCH 3 、HCF 2 C(=O)OCH 3 、HCF 2 C(=O)OC 2 H 5 CF 3 C(=O)OCH 2 C 2 F 5 CF 3 C(=O)OCH 2 CF 2 CF 2 H.CF 3 C(=O)OCH 2 CF 3 CF 3 C(=O)OCH(CF 3 ) 2 , ethyl pentafluorobutyrate, methyl pentafluoropropionate, ethyl pentafluoropropionate, methyl heptafluoroisobutyrate, isopropyl trifluorobutyrate, ethyl trifluoroacetate, tert-butyl trifluoroacetate, n-butyl trifluoroacetate, methyl tetrafluoro-2-(methoxy)propionate, 2,2-difluoroethyl acetate, 2,2,3,3-tetrafluoropropyl acetate, CH 3 C(=O)OCH 2 CF 3 , 2,2,3,3,4,4,4-heptafluorobutyl acetate, methyl 4,4,4-trifluorobutyrate, ethyl 4,4,4-trifluorobutyrate, ethyl 3,3,3-trifluoropropionate, 3,3,3-trifluoropropyl 3,3,3-trifluoropropionate, ethyl 3-(trifluoromethyl)butyrate, methyl 2,3,3,3-tetrafluoropropionate, butyl 2,2-difluoroacetate, methyl 2,2,3,3-tetrafluoropropionate, methyl 2-(trifluoromethyl)-3,3,3-trifluoropropionate, methyl heptafluorobutyrate, and more preferably CF 3 CH 2 C(=O)OCH 3、HCF 2 C(=O)OCH 3 、HCF 2 C(=O)OC 2 H 5 , CH 3 C(=O)OCH 2 CF 3 , HCF is particularly preferred 2 C(=O)OCH 3 、HCF 2 C(=O)OC 2 H 5 , CH 3 C(=O)OCH 2 CF 3 .

[0420] The above-mentioned fluorinated chain carboxylic acid esters may be used alone or in combination of two or more in any ratio.

[0421] When the fluorinated chain carboxylic acid ester is contained, the content of the fluorinated chain carboxylic acid ester is preferably 10 to 90% by volume, more preferably 40 to 85% by volume, and even more preferably 50 to 80% by volume based on the solvent.

[0422] The solvent preferably comprises at least one selected from the cyclic carbonate, the linear carbonate and the linear carboxylic acid ester, more preferably comprises the cyclic carbonate and at least one selected from the linear carbonate and the linear carboxylic acid ester. The cyclic carbonate is preferably a saturated cyclic carbonate.

[0423] The electrolyte solution containing the solvent of the above composition can further improve the high-temperature storage characteristics and cycle characteristics of the electrochemical device.

[0424] Under the situation that above-mentioned solvent comprises above-mentioned cyclic carbonate and at least one being selected from above-mentioned linear carbonate and above-mentioned linear carboxylate, above-mentioned cyclic carbonate and at least one being selected from above-mentioned linear carbonate and above-mentioned linear carboxylate are in total amount, preferably comprise 10~90 volume %, more preferably comprise 30~80 volume %, further preferably comprise 50~70 volume %.

[0425] In the case where the above-mentioned solvent comprises the above-mentioned cyclic carbonate and at least one selected from the above-mentioned linear carbonate and the above-mentioned linear carboxylic acid ester, the volume ratio of the above-mentioned cyclic carbonate and at least one selected from the above-mentioned linear carbonate and the above-mentioned linear carboxylic acid ester is preferably 5 / 95 to 95 / 5; more preferably more than 10 / 90, further preferably more than 15 / 85, particularly preferably more than 20 / 80; more preferably less than 90 / 10, further preferably less than 60 / 40, particularly preferably less than 50 / 50.

[0426] In addition, above-mentioned solvent is also preferably comprised and is selected from at least one of above-mentioned non-fluorinated saturated cyclic carbonate, above-mentioned non-fluorinated chain carbonate and above-mentioned non-fluorinated chain carboxylic acid ester, more preferably comprises above-mentioned non-fluorinated saturated cyclic carbonate and is selected from at least one of above-mentioned non-fluorinated chain carbonate and above-mentioned non-fluorinated chain carboxylic acid ester.The electrolyte that contains the solvent of above-mentioned composition can be suitably used for the electrochemical device that uses under lower voltage.

[0427] In the case where the above-mentioned solvent comprises the above-mentioned non-fluorinated saturated cyclic carbonate and at least one selected from the above-mentioned non-fluorinated chain carbonate and the above-mentioned non-fluorinated chain carboxylic acid ester, the above-mentioned non-fluorinated saturated cyclic carbonate and at least one selected from the above-mentioned non-fluorinated chain carbonate and the above-mentioned non-fluorinated chain carboxylic acid ester are in total amount, preferably comprise 5~90 volume %, more preferably comprise 20~80 volume %, further preferably comprise 30~70 volume %.

[0428] In the case where the above-mentioned electrolyte comprises the above-mentioned non-fluorinated saturated cyclic carbonate and at least one selected from the above-mentioned non-fluorinated chain carbonate and the above-mentioned non-fluorinated chain carboxylic acid ester, the volume ratio of the above-mentioned non-fluorinated saturated cyclic carbonate to at least one selected from the above-mentioned non-fluorinated chain carbonate and the above-mentioned non-fluorinated chain carboxylic acid ester is preferably 5 / 95 to 95 / 5; more preferably 10 / 90 or more, further preferably 15 / 85 or more, particularly preferably 20 / 80 or more; more preferably 90 / 10 or less, further preferably 60 / 40 or less, particularly preferably 50 / 50 or less.

[0429] In addition, above-mentioned solvent is also preferably comprised at least one being selected from above-mentioned fluorinated saturated cyclic carbonate, above-mentioned fluorinated chain carbonate and above-mentioned fluorinated chain carboxylic acid ester, more preferably comprised at least one being selected from above-mentioned fluorinated saturated cyclic carbonate and above-mentioned fluorinated chain carbonate and above-mentioned fluorinated chain carboxylic acid ester.The electrolyte that contains the solvent of above-mentioned composition can not only be applicable to the electrochemical device that uses under lower voltage, can also be applicable to the electrochemical device that uses under higher voltage.

[0430] In the case where the above-mentioned solvent comprises the above-mentioned fluorinated saturated cyclic carbonate and at least one selected from the above-mentioned fluorinated chain carbonate and the above-mentioned fluorinated chain carboxylic ester, the above-mentioned fluorinated saturated cyclic carbonate and at least one selected from the above-mentioned fluorinated chain carbonate and the above-mentioned fluorinated chain carboxylic ester are in total amount, preferably comprise 5~100 volume %, more preferably comprise 10~100 volume %, further preferably comprise 30~100 volume %.

[0431] In the case where the above-mentioned solvent comprises the above-mentioned fluorinated saturated cyclic carbonate and at least one selected from the above-mentioned fluorinated chain carbonate and the above-mentioned fluorinated chain carboxylic ester, the volume ratio of the above-mentioned fluorinated saturated cyclic carbonate and at least one selected from the above-mentioned fluorinated chain carbonate and the above-mentioned fluorinated chain carboxylic ester is preferably 5 / 95 to 95 / 5; more preferably more than 10 / 90, further preferably more than 15 / 85, particularly preferably more than 20 / 80; more preferably less than 90 / 10, further preferably less than 60 / 40, particularly preferably less than 50 / 50.

[0432] In addition, as the above-mentioned solvent, an ionic liquid (however, excluding compound (1)) can also be used. The "ionic liquid" refers to a liquid composed of ions composed of a combination of organic cations and anions.

[0433] The organic cation is not particularly limited, and examples thereof include imidazolium ions such as dialkylimidazolium cations and trialkylimidazolium cations; tetraalkylammonium ions; alkylpyridinium ions; dialkylpyrrolidinium ions; and dialkylpiperidinium ions.

[0434] The anions that counteract these organic cations are not particularly limited, and for example, PF 6 Anion, PF 3 (C 2 F 5 ) 3 Anion, PF 3 (CF 3 ) 3 Anion, BF 4 Anion, BF 2 (CF 3 ) 2 Anion, BF 3 (CF 3 ) anion, bis(oxalatoborate) anion, P(C 2 O 4 )F 2 anion, Tf (trifluoromethanesulfonyl) anion, Nf (nonafluorobutanesulfonyl) anion, bis (fluorosulfonyl) imide anion, bis (trifluoromethanesulfonyl) imide anion, bis (pentafluoroethanesulfonyl) imide anion, dicyanoamide anion, halide anion.

[0435] The above-mentioned solvent is preferably a non-aqueous solvent, and the composition of the present disclosure is preferably a non-aqueous electrolyte.

[0436] The content of the solvent in the electrolyte is preferably 70 to 99.999% by mass, more preferably 80% by mass or more, and more preferably 92% by mass or less.

[0437] As the electrolyte salt of the above-mentioned electrolytic solution, in addition to lithium salts, ammonium salts and metal salts, any salt that can be used for electrolytic solutions, such as liquid salts (ionic liquids), inorganic polymer salts and organic polymer salts, can be used (but excluding compound (1) described later).

[0438] As the electrolyte salt of the electrolyte solution for lithium ion secondary batteries, lithium salt is preferable.

[0439] As the lithium salt, any lithium salt can be used, and specifically, the following lithium salts can be mentioned. For example, LiPF 6 , LiBF 4 、LiClO 4 、LiAlF 4 、LiSbF 6 、LiTaF 6 ,LiWF 7 、LiAsF 6 、LiAlCl 4 、LiI、LiBr、LiCl、LiB 10 Cl 10 , Li 2 SiF 6 , Li 2 PFO 3 、LiPO 2 F 2 Other inorganic lithium salts;

[0440] LiWOF 5 Lithium tungstate and other products;

[0441] HCO 2 Li, CH 3 CO 2 Li, CH 2 FCO 2 Li, CHF 2 CO 2 Li, CF 3 CO 2 Li, CF 3 CH 2 CO 2 Li, CF 3 CF 2 CO 2 Li, CF 3 CF 2 CF 2 CO 2 Li, CF 3 CF 2 CF 2 CF 2 CO 2 Lithium carboxylates such as Li;

[0442] FSO 3 Li, CH 3 SO 3 Li, CH 2 FSO 3 Li, CHF 2 SO 3 Li, CF 3 SO 3 Li, CF 3 CF 2 SO 3 Li, CF 3 CF 2 CF 2 SO 3 Li, CF 3 CF 2 CF 2 CF 2 SO 3 Li, lithium methyl sulfate, lithium ethyl sulfate (C 2 H 5 O SO 3 Li), lithium salts with S=O groups such as lithium 2,2,2-trifluoroethyl sulfate;

[0443] LiN(FCO) 2 、LiN(FCO)(FSO 2 )、LiN(FSO 2 ) 2 、LiN(FSO 2 )(CF 3 SO 2 )、LiN(CF 3 SO 2 ) 2、 LiN(C 2 F 5 SO 2 ) 2 , Lithium bis(perfluoroethanesulfonyl imide), Lithium cyclic 1,2-perfluoroethane disulfonyl imide, Lithium cyclic 1,3-perfluoropropane disulfonyl imide, Lithium cyclic 1,2-ethane disulfonyl imide, Lithium cyclic 1,3-propane disulfonyl imide, Lithium cyclic 1,4-perfluorobutane disulfonyl imide, LiN(CF 3 SO 2 )(F SO 2 )、LiN(CF 3 SO 2 )(C 3 F 7 SO 2 )、LiN(CF 3 SO 2 )(C4 F 9 SO 2 )、LiN(POF 2 ) 2 etc. lithium imide salts;

[0444] LiC(FSO 2 ) 3 、LiC(CF 3 SO 2 ) 3 、LiC(C 2 F 5 SO 2 ) 3 Methylated lithium salts;

[0445] In addition, the formula: LiPF a (C n F 2n+1 ) 6-a (wherein a is an integer from 0 to 5, and n is an integer from 1 to 6) 3 (C 2 F 5 ) 3 、LiPF 3 (CF 3 ) 3 、LiPF 3 (iso-C 3 F 7 ) 3 、LiPF 5 (iso-C 3 F 7 )、LiPF 4 (CF 3 ) 2 、LiPF 4 (C 2 F 5 ) 2 )、LiPF 4 (CF 3 SO 2 ) 2 、LiPF 4 (C 2 F 5 SO 2 ) 2 , L iBF 3 CF 3 , LiBF 3 C 2 F 5 , LiBF 3 C 3 F 7 , LiBF2 (CF 3 ) 2 , LiBF 2 (C 2 F 5 ) 2 , LiBF 2 (CF 3 SO 2 ) 2 , LiBF 2 (C 2 F 5 SO 2 ) 2 Fluorinated organic lithium salts, LiSCN, LiB(CN) 4 、LiB(C 6 H 5 ) 4 , Li 2 (C 2 O 4 )、LiP(C 2 O 4 ) 3 , Li 2 B 12 F b H 12-b (b is an integer from 0 to 3), etc.

[0446] Among them, LiPF is particularly preferred from the viewpoint of improving output characteristics, high-rate charge and discharge characteristics, high-temperature storage characteristics, cycle characteristics, etc. 6 , LiBF 4 、LiSbF 6 、LiTaF 6 、LiPO 2 F 2 、FSO 3 Li, CF 3 SO 3 Li、LiN(FSO 2 ) 2 、LiN(FSO 2 )(CF 3 SO 2 )、LiN(CF 3 SO 2 ) 2 、L iN(C 2 F 5 SO 2 ) 2 、Cyclic 1,2-perfluoroethane disulfonyl imide lithium、Cyclic 1,3-perfluoropropane disulfonyl imide lithium、LiC(FSO 2 ) 3 、LiC(CF3 SO 2 ) 3 、LiC(C 2 F 5 SO 2 ) 3 , LiBF 3 CF 3 , LiBF 3 C 2 F 5 、L iPF 3 (CF 3 ) 3 、LiPF 3 (C 2 F 5 ) 3 etc., most preferably selected from LiPF 6 、LiN(FSO 2 ) 2 and LiBF 4 At least one lithium salt of

[0447] These electrolyte salts may be used alone or in combination of two or more. When two or more are used in combination, LiPF 6 and LiBF 4 and LiPF 6 and LiPO 2 F 2 , C 2 H 5 OSO 3 Li or FSO 3 The combined use of Li has the effect of improving high-temperature storage characteristics, load characteristics, and cycle characteristics.

[0448] In this case, the LiBF content is 100% by mass relative to the total electrolyte solution. 4 、LiPO 2 F 2 , C 2 H 5 OS O 3 Li or FSO 3 The amount of Li incorporated is not limited and is arbitrary as long as it does not significantly impair the effects of the present disclosure. It is usually 0.01% by mass or more, preferably 0.1% by mass or more, relative to the electrolyte; and is usually 30% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less.

[0449] Another example is the use of an inorganic lithium salt and an organic lithium salt. The use of these two together has the effect of inhibiting degradation caused by high-temperature storage. As the organic lithium salt, CF 3SO 3 Li、LiN(FSO 2 ) 2 、LiN(FSO 2 )(CF 3 SO 2 )、LiN(CF 3 SO 2 ) 2 、LiN(C 2 F 5 SO 2 ) 2 、Cyclic 1,2-perfluoroethane disulfonyl imide lithium、Cyclic 1,3-perfluoropropane disulfonyl imide lithium、LiC(FSO 2 ) 3 、LiC(CF 3 SO 2 ) 3 、LiC(C 2 F 5 SO 2 ) 3 , LiBF 3 CF 3 , LiBF 3 C 2 F 5 、LiPF 3 (CF 3 ) 3 、LiPF 3 (C 2 F 5 ) 3 In this case, the ratio of the organic lithium salt to 100% by mass of the entire electrolyte is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more; and is preferably 30% by mass or less, particularly preferably 20% by mass or less.

[0450] The concentration of these electrolyte salts in the electrolyte is not particularly limited as long as it does not impair the effect of the present disclosure. From the viewpoint of making the conductivity of the electrolyte in a good range and ensuring good battery performance, the total molar concentration of lithium in the electrolyte is preferably 0.3 mol / L or more, more preferably 0.4 mol / L or more, and further preferably 0.5 mol / L or more; and preferably 3.0 mol / L or less, more preferably 2.5 mol / L or less, and further preferably 2.0 mol / L or less.

[0451] If the total molar concentration of lithium is too low, the conductivity of the electrolyte may be insufficient. On the other hand, if the concentration is too high, the viscosity increases, so the conductivity may decrease, and the battery performance may decrease.

[0452] The above-mentioned electrolyte solution may further contain a compound (1) represented by the general formula (1).

[0453] General formula (1):

[0454] [Chemistry 40]

[0455]

[0456] (In the formula, A a+ is a metal ion, a hydrogen ion or an onium ion. a is an integer of 1 to 3, b is an integer of 1 to 3, p is b / a, n203 is an integer of 1 to 4, n201 is an integer of 0 to 8, n202 is 0 or 1, and Z 201 A transition metal, an element of Group III, Group IV or Group V of the periodic table.

[0457] X 201 is O, S, an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (the alkylene group, the halogenated alkylene group, the arylene group, and the halogenated arylene group may have a substituent or a heteroatom in their structure. In addition, when n202 is 1 and n203 is 2 to 4, n203 X 201 can be bonded to each other).

[0458] L 201 is a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms (the alkylene group, the halogenated alkylene group, the arylene group, and the halogenated arylene group may have a substituent or a heteroatom in their structure. In addition, when n201 is 2 to 8, n201 L 201 may be bonded to each other to form a ring) or -Z 203 Y 203 .

[0459] Y 201 , Y 202 and Z 203 Each independently is O, S, NY 204 , hydrocarbon group or fluorinated hydrocarbon group. 203 and Y 204 Each of them is independently H, F, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogenated aryl group having 6 to 20 carbon atoms (the alkyl group, the halogenated alkyl group, the aryl group, and the halogenated aryl group may have a substituent or a heteroatom in their structure. When there are multiple Y 203 or Y 204 In the case of , they may be bonded to each other to form a ring).

[0460] As A a+, examples include lithium ion, sodium ion, potassium ion, magnesium ion, calcium ion, barium ion, cesium ion, silver ion, zinc ion, copper ion, cobalt ion, iron ion, nickel ion, manganese ion, titanium ion, lead ion, chromium ion, vanadium ion, ruthenium ion, yttrium ion, lanthanide ion, actinide ion, tetrabutylammonium ion, tetraethylammonium ion, tetramethylammonium ion, triethylmethylammonium ion, triethylammonium ion, pyridinium ion, imidazolium ion, hydrogen ion, tetraethylphosphonium ion, tetramethylphosphonium ion, tetraphenylphosphonium ion, triphenylsulfonium ion, triethylsulfonium ion, etc.

[0461] In the case of electrochemical devices, A a+ Preferred are lithium ions, sodium ions, magnesium ions, tetraalkylammonium ions, and hydrogen ions, and lithium ions are particularly preferred. a+ The valence a of the cation is an integer of 1 to 3. When it is greater than 3, the lattice energy becomes large, so there will be a problem that it becomes difficult to dissolve in the solvent. Therefore, when solubility is required, it is more preferably 1. The valence b of the anion is also an integer of 1 to 3, and is particularly preferably 1. The constant p representing the ratio of the cation to the anion is necessarily determined by the ratio of the valences b / a of the two.

[0462] Next, the ligand part of the general formula (1) is described. In this specification, the ligand part of the general formula (1) and Z 201 The bonded organic or inorganic moieties are called ligands.

[0463] Z 201 Preferred are Al, B, V, Ti, Si, Zr, Ge, Sn, Cu, Y, Zn, Ga, Nb, Ta, Bi, P, As, Sc, Hf or Sb, more preferred are Al, B or P.

[0464] X 201 represents O, S, an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms. These alkylene groups and arylene groups may have substituents or heteroatoms in their structures. Specifically, instead of hydrogen on the alkylene group and the arylene group, there may be halogen atoms, chain or cyclic alkyl groups, aryl groups, alkenyl groups, alkoxy groups, aryloxy groups, sulfonyl groups, amino groups, cyano groups, carbonyl groups, acyl groups, amide groups, or hydroxyl groups as substituents. It may also be a structure in which nitrogen, sulfur, or oxygen is introduced to replace carbon on the alkylene group and the arylene group. In addition, when n202 is 1 and n203 is 2 to 4, n203 X 201 As an example, a ligand such as ethylenediaminetetraacetic acid can be mentioned.

[0465] L 201represents a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms, or -Z 203 Y 203 (About Z 203 , Y 203 The alkyl and aryl groups in this case are also related to X. 201 Similarly, the structure may have a substituent or a heteroatom. In addition, when n201 is 2 to 8, n201 L 201 They may be bonded to each other to form a ring. 201 , preferably a fluorine atom or a cyano group. This is because, in the case of a fluorine atom, the solubility and dissociation degree of the salt of the anionic compound are improved, and this is accompanied by an increase in ionic conductivity. In addition, the oxidation resistance is improved, thereby suppressing the occurrence of side reactions.

[0466] Y 201 , Y 202 and Z 203 Each independently represents O, S, NY 204 , hydrocarbon group or fluorinated hydrocarbon group. 201 and Y 202 Preferably O, S or NY 204 , more preferably O. As a feature of compound (1), there is a 201 and Y 202 and Z 201 bonding, so these ligands are bound to Z 201 The chelate structure is formed. Through the effect of the chelate, the heat resistance, chemical stability and hydrolysis resistance of the compound are improved. The constant n2O2 in the ligand is 0 or 1, but in particular, when n2O2 is 0, the chelate ring is a five-membered ring, so the chelate effect is most strongly exerted, the stability is increased, and it is preferred.

[0467] In addition, in this specification, a fluorinated hydrocarbon group is a group in which at least one hydrogen atom of a hydrocarbon group is replaced by a fluorine atom.

[0468] Y 203 and Y 204 are independently H, F, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogenated aryl group having 6 to 20 carbon atoms, wherein these alkyl groups and aryl groups may have a substituent or a heteroatom in their structure, and in Y 203 or Y 204 When there are plural groups, they may be bonded to each other to form a ring.

[0469] In addition, the constant n203 related to the number of ligands is an integer of 1 to 4, preferably 1 or 2, and more preferably 2. In addition, the constant n201 related to the number of ligands is an integer of 0 to 8, preferably an integer of 0 to 4, and more preferably 0, 2 or 4. Furthermore, when n203 is 1, n201 is 2, and when n203 is 2, n201 is 0.

[0470] In the general formula (1), the alkyl group, the halogenated alkyl group, the aryl group, and the halogenated aryl group also include groups having other functional groups such as a branched chain, a hydroxyl group, and an ether bond.

[0471] The preferred general formula of compound (1) is:

[0472] [Chemistry 41]

[0473]

[0474] (In the formula, A a+ ,a,b,p,n201,Z 201 and L 201 As described above), or the compound of the general formula:

[0475] [Chemistry 42]

[0476]

[0477] (In the formula, A a+ ,a,b,p,n201,Z 201 and L 201 As described above), the compound shown. As compound (1), lithium oxalato borate salts can be mentioned, and the following formula can be mentioned:

[0478] [Chemistry 43]

[0479]

[0480] The lithium bis(oxalato)borate (LIBOB) shown in FIG. 1 has the following formula:

[0481] [Chemistry 44]

[0482]

[0483] The lithium difluorooxalatoborate (LIDFOB) shown in FIG. 1 has the following formula:

[0484] [Chemistry 45]

[0485]

[0486] The lithium difluorooxalato phosphate (LIDFOP) shown in the formula is as follows:

[0487] [Chemistry 46]

[0488]

[0489] The lithium tetrafluorooxalato phosphate (LITFOP) shown in the following formula:

[0490] [Chemistry 47]

[0491]

[0492] The lithium difluorobisoxalato phosphate shown.

[0493] In addition, examples of compound (1) include dicarboxylic acid complex salts in which the central element of the complex is boron, such as lithium bis(malonate)borate, lithium difluoro(malonate)borate, lithium bis(methylmalonate)borate, lithium difluoro(methylmalonate)borate, lithium bis(dimethylmalonate)borate, and lithium difluoro(dimethylmalonate)borate.

[0494] In addition, examples of compound (1) include dicarboxylic acid complex salts in which the central element of the complex is phosphorus, such as lithium tris(oxalato)phosphate, lithium tris(malonate)phosphate, lithium difluorobis(malonate)phosphate, lithium tetrafluoro(malonate)phosphate, lithium tris(methylmalonate)phosphate, lithium difluorobis(methylmalonate)phosphate, lithium tetrafluoro(methylmalonate)phosphate, lithium tris(dimethylmalonate)phosphate, lithium difluorobis(dimethylmalonate)phosphate, and lithium tetrafluoro(dimethylmalonate)phosphate.

[0495] In addition, examples of the compound (1) include LiAl(C 2 O 4 ) 2 、LiAlF 2 (C 2 O 4 ) and other dicarboxylic acid complex salts whose central element is aluminum.

[0496] Among them, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tri(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate are more preferably used from the viewpoint of easy availability and contribution to the formation of a stable film-like structure.

[0497] As the compound (1), lithium bis(oxalato)borate is particularly preferred.

[0498] From the viewpoint of obtaining further excellent cycle characteristics, the content of the compound (1) is preferably 0.001 mass % or more, more preferably 0.01 mass % or more, and preferably 10 mass % or less, more preferably 3 mass % or less, based on the above-mentioned solvent.

[0499] The above electrolyte preferably further comprises general formula (2):

[0500] [Chemistry 48]

[0501]

[0502] (Where X 21 is a group containing at least H or C; n21 is an integer from 1 to 3; Y 21 and Z 21 are the same or different and are groups containing at least H, C, O or F; n22 is 0 or 1; Y 21 and Z 21 The electrolyte solution containing the compound (2) is unlikely to further decrease the capacity retention rate and further increase the amount of gas generated even when stored at high temperatures.

[0503] When n21 is 2 or 3, 2 or 3 X 21 Can be the same or different.

[0504] In the presence of multiple Y 21 and Z 21 In the case of multiple Y 21 and Z 21 Can be the same or different.

[0505] As X 21 , preferably -CY 21 Z 21 -(where Y 21 and Z 21 as above) or -CY 21 =CZ 21 -(where Y 21 and Z 21 As described above).

[0506] As Y 21 , preferably selected from H-, F-, CH 3 -、CH 3 CH 2 -、CH 3 CH 2 CH 2 -、CF 3 -、CF 3 CF 2 -、CH 2 FCH 2 - and CF 3 CF 2 CF 2 -At least one of the following.

[0507] As Z 21 , preferably selected from H-, F-, CH 3 -、CH 3 CH 2 -、CH 3 CH 2 CH 2 -、CF 3 -、CF 3 CF 2 -、CH 2 FCH 2 - and CF 3 CF 2 CF 2 -At least one of the following.

[0508] Or, Y 21 and Z 21 They may be bonded to each other to include an unsaturated bond, and may form a carbocyclic ring or a heterocyclic ring which may have aromaticity. The number of carbon atoms in the ring is preferably 3 to 20.

[0509] Next, a specific example of compound (2) is described. It should be noted that in the following examples, "analogs" refer to an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure within the scope of the present disclosure, for example, dimers, trimers and tetramers composed of multiple acid anhydrides; or substances with the same number of carbon atoms in the substituent but with structural isomers such as branching, substances with different positions of the substituent bonded to the acid anhydride, etc.

[0510] Specific examples of the acid anhydride forming a five-membered ring structure include succinic anhydride, methylsuccinic anhydride (4-methylsuccinic anhydride), dimethylsuccinic anhydride (4,4-dimethylsuccinic anhydride, 4,5-dimethylsuccinic anhydride, etc.), 4,4,5-trimethylsuccinic anhydride, 4,4,5,5-tetramethylsuccinic anhydride, 4-vinylsuccinic anhydride, 4,5-divinylsuccinic anhydride, phenylsuccinic anhydride (4-phenylsuccinic anhydride), 4,5 -diphenylsuccinic anhydride, 4,4-diphenylsuccinic anhydride, citraconic anhydride, maleic anhydride, methylmaleic anhydride (4-methylmaleic anhydride), 4,5-dimethylmaleic anhydride, phenylmaleic anhydride (4-phenylmaleic anhydride), 4,5-diphenylmaleic anhydride, itaconic anhydride, 5-methylitaconic anhydride, 5,5-dimethylitaconic anhydride, phthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, and the like, and the like.

[0511] Specific examples of the acid anhydride forming a six-membered ring structure include cyclohexanedicarboxylic anhydride (cyclohexane-1,2-dicarboxylic anhydride, etc.), 4-cyclohexene-1,2-dicarboxylic anhydride, glutaric anhydride, glutaconic anhydride, 2-phenylglutaric anhydride, and the like, and analogs thereof.

[0512] Specific examples of other acid anhydrides forming a ring structure include 5-norbornene-2,3-dicarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, pyromellitic anhydride, diglycolic anhydride, and analogs thereof.

[0513] Specific examples of the acid anhydride forming a ring structure and substituted with a halogen atom include monofluorosuccinic anhydride (such as 4-fluorosuccinic anhydride), 4,4-difluorosuccinic anhydride, 4,5-difluorosuccinic anhydride, 4,4,5-trifluorosuccinic anhydride, trifluoromethylsuccinic anhydride, tetrafluorosuccinic anhydride (4,4,5,5-tetrafluorosuccinic anhydride), 4-fluoromaleic anhydride, 4,5-difluoromaleic anhydride, trifluoromethylmaleic anhydride, 5-fluoroitaconic anhydride, 5,5-difluoroitaconic anhydride, and analogs thereof.

[0514] Among them, preferred compounds (2) are glutaric anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic anhydride, cyclopentanetetracarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, phenylsuccinic anhydride, 2-phenylglutaric anhydride, maleic anhydride, methylmaleic anhydride, trifluoromethylmaleic anhydride, phenylmaleic anhydride, succinic anhydride, methylsuccinic anhydride, dimethylsuccinic anhydride, trifluoromethylsuccinic anhydride, monofluorosuccinic anhydride, and tetrafluorosuccinic anhydride; more preferred are maleic anhydride, methylmaleic anhydride, trifluoromethylmaleic anhydride, succinic anhydride, methylsuccinic anhydride, trifluoromethylsuccinic anhydride, and tetrafluorosuccinic anhydride; and even more preferred are maleic anhydride and succinic anhydride.

[0515] Compound (2) is preferably selected from the general formula (3):

[0516] [Chemistry 49]

[0517]

[0518] (Where X 31 ~X 34 The same or different, being a group containing at least H, C, O or F) and the general formula (4):

[0519] [Chemistry 50]

[0520]

[0521] (Where X 41 and X 42 The compound (4) is a group which is the same or different and contains at least H, C, O or F.

[0522] As X 31 ~X34 , which are the same or different, are preferably at least one selected from an alkyl group, a fluoroalkyl group, an alkenyl group and a fluoroalkenyl group. 31 ~X 34 The number of carbon atoms in is preferably 1-10, more preferably 1-3.

[0523] As X 31 ~X 34 , the same or different, more preferably selected from H-, F-, CH 3 -、CH 3 CH 2 -、CH 3 CH 2 CH 2 -、CF 3 -、CF 3 CF 2 -、CH 2 FCH 2 - and CF 3 CF 2 CF 2 -At least one of the following.

[0524] As X 41 and X 42 , which are the same or different, are preferably at least one selected from an alkyl group, a fluoroalkyl group, an alkenyl group and a fluoroalkenyl group. 41 and X 42 The number of carbon atoms in is preferably 1-10, more preferably 1-3.

[0525] As X 41 and X 42 , the same or different, more preferably selected from H-, F-, CH 3 -、CH 3 CH 2 -、CH 3 CH 2 CH 2 -、CF 3 -、CF 3 CF 2 -、CH 2 FCH 2 - and CF 3 CF 2 CF 2 -At least one of the following.

[0526] The compound (3) is preferably any one of the following compounds.

[0527] [Chemistry 51]

[0528]

[0529] The compound (4) is preferably any one of the following compounds.

[0530] [Chemistry 52]

[0531]

[0532] The electrolyte preferably contains 0.0001 to 15% by mass of compound (4) relative to the electrolyte, from the viewpoint that the capacity retention rate is not likely to be further reduced and the amount of gas generated is not likely to be further increased even when stored at high temperatures. The content of compound (4) is more preferably 0.01 to 10% by mass, further preferably 0.1 to 3% by mass, and particularly preferably 0.1 to 1.0% by mass.

[0533] In the case where the above-mentioned electrolyte contains both compounds (3) and (4), from the viewpoint that the capacity retention rate is not likely to be further reduced and the amount of gas generated is not likely to be further increased when stored at high temperatures, the above-mentioned electrolyte preferably contains 0.08 to 2.50 mass % of compound (3) and 0.02 to 1.50 mass % of compound (4), and more preferably contains 0.80 to 2.50 mass % of compound (3) and 0.08 to 1.50 mass % of compound (4) relative to the above-mentioned electrolyte.

[0534] The electrolyte solution may contain at least one selected from the group consisting of nitrile compounds represented by the following general formulae (1a), (1b), and (1c).

[0535] [Chemistry 53]

[0536]

[0537] (Where R a and R b Each independently represents a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of an alkyl group are replaced by halogen atoms. n represents an integer of 1 to 10.

[0538] [Chemistry 54]

[0539]

[0540] (Where R c represents a hydrogen atom, a halogen atom, an alkyl group, a group in which at least a part of the hydrogen atoms of an alkyl group are replaced by halogen atoms, or NC-R c1 -X c1 -(R c1 represents an alkylene group, X c1 represents an oxygen atom or a sulfur atom. d and R eEach independently represents a hydrogen atom, a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of an alkyl group are replaced by halogen atoms. m represents an integer of 1 to 10.

[0541] [Chemistry 55]

[0542]

[0543] (Where R f , R g , R h and R i Each independently represents a group containing a cyano group (CN), a hydrogen atom (H), a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of an alkyl group are replaced by halogen atoms. f , R g , R h and R i At least one of the groups is a group containing a cyano group. l represents an integer of 1 to 3.)

[0544] This can improve the high temperature storage characteristics of the electrochemical device. The above-mentioned nitrile compounds may be used alone or in any combination and ratio.

[0545] In the above general formula (1a), R a and R b Each is independently a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of an alkyl group are substituted with a halogen atom.

[0546] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, among which a fluorine atom is preferred.

[0547] The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a tert-butyl group.

[0548] Examples of the group in which at least a part of hydrogen atoms of an alkyl group are substituted with halogen atoms include groups in which at least a part of hydrogen atoms of the above-mentioned alkyl group are substituted with the above-mentioned halogen atoms.

[0549] In R a and R b In the case of an alkyl group or a group in which at least a part of the hydrogen atoms of an alkyl group are replaced by halogen atoms, R a and R b They may be bonded to each other to form a ring structure (for example, a cyclohexane ring).

[0550] R a and R b A hydrogen atom or an alkyl group is preferred.

[0551] In the above general formula (1a), n is an integer of 1 to 10. When n is 2 or more, n R a They may all be the same or at least partly different. b The same is true. n is preferably an integer of 1-7, and more preferably an integer of 2-5.

[0552] As the nitrile compound represented by the general formula (1a), dinitriles and trinitriles are preferred.

[0553] Specific examples of dinitriles include malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, octanonitrile, azelaic acid, sebacononitrile, undecane dicarbonitrile, dodecane dicarbonitrile, methyl malononitrile, ethyl malononitrile, isopropyl malononitrile, tert-butyl malononitrile, methyl succinonitrile, 2,2-dimethyl succinonitrile, 2,3-dimethyl succinonitrile, 2,3,3-trimethyl succinonitrile, 2,2,3,3-tetramethyl succinonitrile, 2,3-diethyl-2,3-dimethyl succinonitrile, 2,2-diethyl-3,3-dimethyl succinonitrile, dicyclohexane-1,1-dicarbonitrile, dicyclohexane-2,2-dicarbonitrile, dicyclohexane-3,3-dicarbonitrile, 2,5-dimethyl-2,5-hexane dicarbonitrile, 2,3-diisobutyl-2,3-dimethyl succinonitrile, 2,2-diisobutyl-2,3-dimethyl succinonitrile, Butyl-3,3-dimethylsuccinonitrile, 2-methylglutaronitrile, 2,3-dimethylglutaronitrile, 2,4-dimethylglutaronitrile, 2,2,3,3-tetramethylglutaronitrile, 2,2,4,4-tetramethylglutaronitrile, 2,2,3,4-tetramethylglutaronitrile, 2,3,3,4-tetramethylglutaronitrile, 1,4-dicyanopentane, 2,6-dicyanoheptane, 2,7-dicyano octane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-dicyanobenzene, 1,3-dicyanobenzene, 1,4-dicyanobenzene, 3,3′-(ethylenedioxy)dipropionitrile, 3,3′-(ethylenedisulfide)dipropionitrile, 3,9-bis(2-cyanoethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, butyronitrile, phthalonitrile, etc. Among these, succinonitrile, glutaronitrile, and adiponitrile are particularly preferred.

[0554] Specific examples of the trinitriles include pentaerythritol, propane tricarbonitrile, 1,3,5-hexane tricarbonitrile, 1,3,6-hexane tricarbonitrile, heptane tricarbonitrile, 1,2,3-propane tricarbonitrile, 1,3,5-pentane tricarbonitrile, cyclohexane tricarbonitrile, tricyanoethylamine, tricyanoethoxypropane, tricyanoethylene, tris(2-cyanoethyl)amine, and the like. 1,3,6-hexane tricarbonitrile and cyclohexane tricarbonitrile are particularly preferred, and cyclohexane tricarbonitrile is most preferred.

[0555] In the above general formula (1b), R cis a hydrogen atom, a halogen atom, an alkyl group, a group in which at least a part of the hydrogen atoms of an alkyl group are replaced by halogen atoms, or NC-R c1 -X c1 -(R c1 represents an alkylene group, X c1 represents an oxygen atom or a sulfur atom. ) represented by a group, R d and R e Each is independently a hydrogen atom, a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of an alkyl group are substituted with halogen atoms.

[0556] Examples of the halogen atom, the alkyl group, and the group in which at least a part of hydrogen atoms of the alkyl group is substituted with a halogen atom include the groups exemplified for the above-mentioned general formula (1a).

[0557] The above NC-R c1 -X c1 -R in c1 The alkylene group is preferably an alkylene group having 1 to 3 carbon atoms.

[0558] R c , R d and R e Each of them is independently preferably a hydrogen atom, a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of an alkyl group are substituted with halogen atoms.

[0559] R c , R d and R e At least one of them is preferably a halogen atom or a group in which at least a part of hydrogen atoms of an alkyl group are substituted with a halogen atom, and more preferably a fluorine atom or a group in which at least a part of hydrogen atoms of an alkyl group are substituted with a fluorine atom.

[0560] In R d and R e In the case of an alkyl group or a group in which at least a part of the hydrogen atoms of an alkyl group are replaced by halogen atoms, R d and R e They may be bonded to each other to form a ring structure (for example, a cyclohexane ring).

[0561] In the above general formula (1b), m is an integer of 1 to 10. When m is 2 or more, m R d They may all be the same or at least partly different. e m is preferably an integer of 2-7, and more preferably an integer of 2-5.

[0562] Examples of the nitrile compound represented by the general formula (1b) include acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 3-methoxypropionitrile, 2-methylbutyronitrile, trimethylacetonitrile, hexanecarbonitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-difluoropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3,3′-oxydipropionitrile, 3,3′-thiodipropionitrile, pentafluoropropionitrile, methoxyacetonitrile, and benzonitrile. Among them, 3,3,3-trifluoropropionitrile is particularly preferred.

[0563] In the above general formula (1c), R f , R g , R h and R i Each is independently a group containing a cyano group (CN), a hydrogen atom, a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of an alkyl group are substituted with a halogen atom.

[0564] Examples of the halogen atom, the alkyl group, and the group in which at least a part of hydrogen atoms of the alkyl group is substituted with a halogen atom include the groups exemplified for the above general formula (1a).

[0565] Examples of the group containing a cyano group include, in addition to a cyano group, a group in which at least a part of hydrogen atoms of an alkyl group is replaced by a cyano group. Examples of the alkyl group in this case include the groups exemplified for the above general formula (1a).

[0566] R f , R g , R h and R i At least one of them is a group containing a cyano group. f , R g , R h and R i At least two of them are groups containing a cyano group, and more preferably R h and R i is a group containing a cyano group. h and R i In the case of a group containing a cyano group, R f and R g Preferred is a hydrogen atom.

[0567] In the above general formula (1c), l is an integer of 1 to 3. When l is 2 or more, one R f They may all be the same or at least partly different. g The same is true. l is preferably an integer of 1-2.

[0568] Examples of the nitrile compound represented by the general formula (1c) include 3-hexenedinitrile, 2,4-mucononitrile, maleonitrile, fumaric acid nitrile, acrylonitrile, methacrylonitrile, crotononitrile, 3-methylcrotononitrile, 2-methyl-2-butenenitrile, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, and 2-hexenenitrile. Preferably, 3-hexenedinitrile and 2,4-hexenedinitrile are used, and 3-hexenedinitrile is particularly preferred.

[0569] The content of the nitrile compound is preferably 0.2 to 7% by mass relative to the electrolyte. Thus, the high-temperature storage characteristics and safety of the electrochemical device under high voltage can be further improved. The lower limit of the total content of the nitrile compound is more preferably 0.3% by mass, more preferably 0.5% by mass. The upper limit is more preferably 5% by mass, more preferably 2% by mass, and particularly preferably 0.5% by mass.

[0570] The electrolyte may contain a compound having an isocyanate group (hereinafter, sometimes referred to as "isocyanate"). The isocyanate is not particularly limited, and any isocyanate may be used. Examples of isocyanates include monoisocyanates, diisocyanates, triisocyanates, and the like.

[0571] Specific examples of the monoisocyanates include isocyanatomethane, isocyanatoethane, 1-isocyanatopropane, 1-isocyanatobutane, 1-isocyanatopentane, 1-isocyanatohexane, 1-isocyanatoheptane, 1-isocyanatooctane, 1-isocyanatononane, 1-isocyanatodecane, isocyanatocyclohexane, methoxycarbonyl isocyanate, ethoxycarbonyl isocyanate, propoxycarbonyl isocyanate, butoxycarbonyl isocyanate, methoxysulfonyl isocyanate, ethoxysulfonyl isocyanate, propoxysulfonyl isocyanate, butoxysulfonyl isocyanate, fluorosulfonyl isocyanate, methyl isocyanate, butyl isocyanate, phenyl isocyanate, 2-isocyanoethyl acrylate, 2-isocyanoethyl methacrylate, and ethyl isocyanate.

[0572] Specific examples of diisocyanates include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1,7-diisocyanatoheptane, 1,8-diisocyanatooctane, 1,9-diisocyanatononane, 1,10-diisocyanatodecane, 1,3-diisocyanatopropylene, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-propene, 1,4-diisocyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5-diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato-3-hexene, 1,6-diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluorohexane, toluene diisocyanate (toluene d iisocyanate), xylene diisocyanate, tolylenediisocyanate, 1,2-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1′-diisocyanate, dicyclohexylmethane-2,2′-diisocyanate ester, dicyclohexylmethane-3,3′-diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, isophorone diisocyanate, 2,5-bis(isocyanatemethyl)bicyclo[2.2.1]heptane, 2,6-bis(isocyanatemethyl)bicyclo[2.2.1]heptane, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, 1,4-phenylene diisocyanate, octamethylene diisocyanate, tetramethylene diisocyanate, and the like.

[0573] Specific examples of triisocyanates include 1,6,11-triisocyanatoundecane, 4-isocyanatomethyl-1,8-octamethylene diisocyanate, 1,3,5-triisocyanatomethylbenzene, 1,3,5-tris(6-isocyanatohexane-1-yl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 4-(isocyanatomethyl)octamethylene diisocyanate.

[0574] Among them, 1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,3,5-tris(6-isocyanatohexane-1-yl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,4,4-trimethylhexamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate are industrially readily available and can suppress the manufacturing cost of the electrolyte to a low level, so they are preferred. In addition, from a technical point of view, they can also contribute to the formation of a stable film-like structure and are more preferably used.

[0575] The content of isocyanate is not particularly limited, and can be arbitrary as long as it does not significantly damage the effect of the present disclosure. It is preferably 0.001% by mass or more and 1.0% by mass or less relative to the electrolyte. If the content of isocyanate is above the lower limit, it is possible to bring a sufficient effect of improving the cycle characteristics of the non-aqueous electrolyte secondary battery. In addition, if it is below the upper limit, the initial resistance increase of the non-aqueous electrolyte secondary battery can be avoided. The content of isocyanate is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more; and, more preferably 0.8% by mass or less, further preferably 0.7% by mass or less, and particularly preferably 0.6% by mass or less.

[0576] The electrolyte may contain a cyclic sulfonic acid ester. The cyclic sulfonic acid ester is not particularly limited, and any cyclic sulfonic acid ester may be used. Examples of the cyclic sulfonic acid ester include saturated cyclic sulfonic acid esters, unsaturated cyclic sulfonic acid esters, saturated cyclic disulfonic acid esters, and unsaturated cyclic disulfonic acid esters.

[0577] Specific examples of the saturated cyclic sulfonic acid esters include 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-methyl-1,3-propane sultone, 2-methyl-1,3-propane sultone, 3-methyl-1,3-propane sultone, 1,3-butane sultone, 1,4-butane sultone, Sultone, 1-fluoro-1,4-butane sultone, 2-fluoro-1,4-butane sultone, 3-fluoro-1,4-butane sultone, 4-fluoro-1,4-butane sultone, 1-methyl-1,4-butane sultone, 2-methyl-1,4-butane sultone, 3-methyl-1,4-butane sultone, 4-methyl-1,4-butane sultone, 2,4-butane sultone, etc.

[0578] Specific examples of the unsaturated cyclic sulfonic acid ester include 1-propylene-1,3-sultone, 2-propylene-1,3-sultone, 1-fluoro-1-propylene-1,3-sultone, 2-fluoro-1-propylene-1,3-sultone, 3-fluoro-1-propylene-1,3-sultone, 1-fluoro-2-propylene-1,3-sultone, 2-fluoro-2-propylene-1,3-sultone, 3-fluoro-2-propylene-1,3-sultone, 1-methyl-1-propylene-1,3-sultone, 2-methyl-1-propylene-1,3-sultone, Esters, 3-methyl-1-propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-methyl-2-propene-1,3-sultone, 1-butene-1,4-sultone, 2-butene-1,4-sultone, 3-butene-1,4-sultone, 1-fluoro-1-butene-1,4-sultone, 2-fluoro-1-butene-1,4-sultone, 3-fluoro-1-butene-1,4-sultone, 4-fluoro-1-butene-1,4-sultone, 1-Fluoro-2-butene-1,4-sultone, 2-Fluoro-2-butene-1,4-sultone, 3-Fluoro-2-butene-1,4-sultone, 4-Fluoro-2-butene-1,4-sultone, 1,3-Propene sultone, 1-Fluoro-3-butene-1,4-sultone, 2-Fluoro-3-butene-1,4-sultone, 3-Fluoro-3-butene-1,4-sultone, 4-Fluoro-3-butene-1,4-sultone, 1-Methyl-1-butene-1,4-sultone, 2-Methyl-1-butene-1,4-sultone , 3-methyl-1-butene-1,4-sultone, 4-methyl-1-butene-1,4-sultone, 1-methyl-2-butene-1,4-sultone, 2-methyl-2-butene-1,4-sultone, 3-methyl-2-butene-1,4-sultone, 4-methyl-2-butene-1,4-sultone, 1-methyl-3-butene-1,4-sultone, 2-methyl-3-butene-1,4-sultone, 3-methyl-3-butene-1,4-sultone, 4-methyl-3-butene-1,4-sultone, etc.

[0579] Among them, from the viewpoint of being easy to obtain and contributing to forming a stable film-like structure, 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, and 1-propylene-1,3-sultone are more preferably used. The content of the cyclic sulfonic acid ester is not particularly limited and may be any content as long as the effect of the present disclosure is not significantly impaired, but is preferably 0.001 mass % or more and 3.0 mass % or less relative to the electrolyte.

[0580] If the content of the cyclic sulfonate is above the lower limit, the non-aqueous electrolyte secondary battery can be sufficiently improved in terms of cycle characteristics. If it is below the upper limit, the increase in the manufacturing cost of the non-aqueous electrolyte secondary battery can be avoided. The content of the cyclic sulfonate is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more; and more preferably 2.5% by mass or less, further preferably 2.0% by mass or less, and particularly preferably 1.8% by mass or less.

[0581] The electrolyte solution may further contain polyoxyethylene having a weight average molecular weight of 2,000 to 4,000 and having -OH, -OC OOH or -COOH at the terminal.

[0582] By including such a compound, the stability of the electrode interface is improved, and the characteristics of the electrochemical device can be improved.

[0583] Examples of the polyoxyethylene include polyoxyethylene monool, polyoxyethylene formic acid, polyoxyethylene diol, polyoxyethylene dicarboxylic acid, polyoxyethylene triol, polyoxyethylene trimaric acid, etc. These may be used alone or in combination of two or more.

[0584] Among them, a mixture of polyoxyethylene monoalcohol and polyoxyethylene diol, and a mixture of polyvinyl formic acid and polyethylene dicarboxylic acid are preferred in terms of better battery characteristics.

[0585] If the weight average molecular weight of the polyoxyethylene is too small, it may be easily oxidatively decomposed. The weight average molecular weight is more preferably 3,000 to 4,000.

[0586] The weight average molecular weight can be measured in terms of polystyrene by gel permeation chromatography (GPC).

[0587] The content of the above-mentioned polyoxyethylene in the electrolyte is preferably 1×10 -6 ~1×10 -2 If the content of the above-mentioned polyoxyethylene is too high, the characteristics of the electrochemical device may be impaired.

[0588] The content of the polyoxyethylene is more preferably 5×10 -6 mol / kg or more.

[0589] The electrolyte solution may further contain a fluorinated saturated cyclic carbonate, an unsaturated cyclic carbonate, an overcharge preventer, other known auxiliary agents, etc. as additives, thereby suppressing the degradation of the characteristics of the electrochemical device.

[0590] As the fluorinated saturated cyclic carbonate, the compound shown in the above-mentioned general formula (A) can be cited. Among them, preferably fluorinated ethylene carbonate, difluoroethylene carbonate, monofluoromethyl ethylene carbonate, trifluoromethyl ethylene carbonate, 2,2,3,3,3-pentafluoropropyl ethylene carbonate (4-(2,2,3,3,3-pentafluoropropyl)-[1,3]dioxolane-2-one). The fluorinated saturated cyclic carbonate can be used alone or in any combination and ratio.

[0591] The content of the fluorinated saturated cyclic carbonate is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and even more preferably 0.1 to 3% by mass, based on the electrolytic solution.

[0592] Examples of the unsaturated cyclic carbonate include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, and catechol carbonates.

[0593] Examples of the vinylene carbonates include vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, 4,5-divinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, 4-fluorovinylene carbonate, 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-phenyl vinylene carbonate, 4-fluoro-5-vinyl vinylene carbonate, 4-allyl-5-fluorovinylene carbonate, ethynyl ethylene carbonate, propargyl ethylene carbonate, methyl vinylene carbonate, and dimethyl vinylene carbonate.

[0594] Specific examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond include vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5-vinyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate. 5-ethynylethylene carbonate, phenylethylene carbonate, 4,5-diphenylethylene carbonate, 4-phenyl-5-vinylethylene carbonate, 4-allyl-5-phenylethylene carbonate, allylethylene carbonate, 4,5-diallylethylene carbonate, 4-methyl-5-allylethylene carbonate, 4-methylene-1,3-dioxolane-2-one, 4,5-dimethylene-1,3-dioxolane-2-one, 4-methyl-5-allylethylene carbonate, and the like.

[0595] Wherein, as unsaturated cyclic carbonate, preferably: vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5-vinyl ethylene carbonate, allyl ethylene carbonate, 4,5-diallyl ethylene carbonate, 4-methyl-5-allyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate. In addition, vinylene carbonate, vinyl ethylene carbonate, and ethynyl ethylene carbonate can form a more stable interface protection film, so it is particularly preferred, and vinylene carbonate is most preferably used.

[0596] The molecular weight of unsaturated cyclic carbonate is not particularly limited, as long as the effect of the present disclosure is not significantly damaged, then it can be any molecular weight.Molecular weight is preferably more than 50 and below 250.If within the scope, then easily ensure that the unsaturated cyclic carbonate is relative to the solubility of electrolyte, easily give full play to the effect of the present disclosure.The molecular weight of unsaturated cyclic carbonate is more preferably more than 80, in addition, more preferably below 150.

[0597] The method for producing the unsaturated cyclic carbonate is not particularly limited, and the unsaturated cyclic carbonate can be produced by arbitrarily selecting a known method.

[0598] The unsaturated cyclic carbonate may be used alone or in combination of two or more in any ratio.

[0599] The content of the above-mentioned unsaturated cyclic carbonate is not particularly limited, as long as the effect of the present disclosure is not significantly damaged, then it can be any content. The content of the above-mentioned unsaturated cyclic carbonate is preferably more than 0.001 mass % in 100 mass % of electrolyte, more preferably more than 0.01 mass %, and further preferably more than 0.1 mass %. In addition, the above-mentioned content is preferably less than 5 mass %, more preferably less than 4 mass %, and further preferably less than 3 mass %. As long as it is within the above scope, the electrochemical device using the electrolyte is easy to show sufficient cycle characteristics to improve the effect, in addition, it is easy to avoid the high temperature storage characteristics to reduce, the gas generation amount to become more, and the discharge capacity retention rate to reduce such a situation.

[0600] As the unsaturated cyclic carbonate, in addition to the above-mentioned non-fluorinated unsaturated cyclic carbonate, a fluorinated unsaturated cyclic carbonate can also be preferably used.

[0601] Fluorinated unsaturated cyclic carbonate is a cyclic carbonate with unsaturated bonds and fluorine atoms. As long as the quantity of the fluorine atoms possessed by the fluorinated unsaturated cyclic carbonate is more than 1, there is no particular restriction. Wherein, the fluorine atoms are generally below 6, preferably below 4, most preferably 1 or 2.

[0602] Examples of the fluorinated unsaturated cyclic carbonate include fluorinated vinylene carbonate derivatives and fluorinated ethylene carbonate derivatives substituted with a substituent having an aromatic ring or a carbon-carbon double bond.

[0603] Examples of the fluorinated vinylene carbonate derivatives include 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, and 4-fluoro-5-vinylvinylene carbonate.

[0604] Examples of the fluoroethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond include 4-fluoro-4-vinylethylene carbonate, 4-fluoro-4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5- Difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-diallylethylene carbonate, 4-fluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate, and the like.

[0605] Among them, as the fluorinated unsaturated cyclic carbonate, the following compounds are more preferably used because they form a stable interface protective film: 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, 4-fluoro-4-vinylethylene carbonate, 4-fluoro-4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylcarbonate Ethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-diallylethylene carbonate.

[0606] The molecular weight of fluorinated unsaturated cyclic carbonate is not particularly limited, and can be any molecular weight as long as the effect of the present disclosure is not significantly damaged. The molecular weight is preferably more than 50, and is below 500. As long as it is the scope, it is easy to ensure the solubility of fluorinated unsaturated cyclic carbonate relative to electrolyte.

[0607] The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production. The molecular weight is more preferably 100 or more, and more preferably 200 or less.

[0608] Fluorinated unsaturated cyclic carbonate can be used alone as one, or in any combination and ratio and in combination with more than two. In addition, the content of fluorinated unsaturated cyclic carbonate is not particularly limited, as long as the effect of the present disclosure is not significantly damaged, it is any content. The content of fluorinated unsaturated cyclic carbonate is usually in 100% by mass of electrolyte, preferably more than 0.001% by mass, more preferably more than 0.01% by mass, more preferably more than 0.1% by mass, and preferably less than 5% by mass, more preferably less than 4% by mass, more preferably less than 3% by mass. As long as it is within the scope, the electrochemical device using the electrolyte is easy to show sufficient cycle characteristics to improve the effect, in addition, it is easy to avoid the reduction of high temperature storage characteristics, the increase of gas generation, and the reduction of discharge capacity retention rate.

[0609] The electrolyte solution may contain a compound having a triple bond. The compound may be any compound as long as it has one or more triple bonds in the molecule, and the type thereof is not particularly limited.

[0610] Specific examples of the compound having a triple bond include the following compounds.

[0611] 1-pentyne, 2-pentyne, 1-hexyne, 2-hexyne, 3-hexyne, 1-heptyne, 2-heptyne, 3-heptyne, 1-octyne, 2-octyne, 3-octyne, 4-octyne, 1-nonyne, 2-nonyne, 3-nonyne, 4-nonyne, 1-dodecyne, 2-dodecyne, 3-dodecyne, 4-dodecyne, 5-dodecyne, phenylacetylene, 1-phenyl-1-propyne, 1-phenyl-2-propyne, 1-phenyl-1-butyne, 4-phenyl-1-butyne, 4-phenyl-1-butyne, 1-phenyl-1-pentyne, 5-phenyl-1-pentyne, 1-phenyl-1-hexyne, 6-phenyl-1-hexyne, diphenylacetylene, 4-ethynyltoluene, dicyclohexylacetylene and the like hydrocarbon compounds;

[0612] 2-propynyl methyl carbonate, 2-propynyl ethyl carbonate, 2-propynyl propyl carbonate, 2-propynyl butyl carbonate, 2-propynyl phenyl carbonate, 2-propynyl cyclohexyl carbonate, di(2-propynyl) carbonate, 1-methyl-2-propynyl methyl carbonate, 1,1-dimethyl-2-propynyl methyl carbonate, 2-butynyl methyl carbonate, 3-butynyl methyl carbonate, 2-pentynyl methyl carbonate, Monocarbonates such as 3-pentynyl methyl carbonate and 4-pentynyl methyl carbonate; dicarbonates such as 2-butyne-1,4-diol dimethyl dicarbonate, 2-butyne-1,4-diol diethyl dicarbonate, 2-butyne-1,4-diol dipropyl dicarbonate, 2-butyne-1,4-diol dibutyl dicarbonate, 2-butyne-1,4-diol diphenyl dicarbonate and 2-butyne-1,4-diol dicyclohexyl dicarbonate;

[0613] 2-Propynyl acetate, 2-propynyl propionate, 2-propynyl butyrate, 2-propynyl benzoate, 2-propynyl cyclohexanecarboxylate, 1,1-dimethyl-2-propynyl acetate, 1,1-dimethyl-2-propynyl propionate, 1,1-dimethyl-2-propynyl butyrate, 1,1-dimethyl-2-propynyl benzoate, 1,1-dimethyl-2-propynyl cyclohexanecarboxylate, 2-butynyl acetate, 3-butynyl acetate, 2-pentynyl acetate, 3-pentynyl acetate, 4-pentynyl acetate, methyl acrylate, ethyl acrylate Ester, propyl acrylate, vinyl acrylate, 2-propylene acrylate, 2-butylene acrylate, 3-butylene acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, vinyl methacrylate, 2-propylene methacrylate, 2-butylene methacrylate, 3-butylene methacrylate, methyl 2-propiolate, ethyl 2-propiolate, propyl 2-propiolate, vinyl 2-propiolate, 2-propylene 2-propiolate, 2-butylene 2-propiolate, 3-butylene 2-propiolate, 2-butylene 2-Butynoic acid methyl ester, 2-butynoic acid ethyl ester, 2-butynoic acid propyl ester, 2-butynoic acid vinyl ester, 2-butynoic acid 2-propenyl ester, 2-butynoic acid 2-butenyl ester, 2-butynoic acid 3-butynoic acid methyl ester, 3-butynoic acid ethyl ester, 3-butynoic acid propyl ester, 3-butynoic acid vinyl ester, 3-butynoic acid 2-propenyl ester, 3-butynoic acid 2-butenyl ester, 3-butynoic acid 3-butynoic acid methyl ester, 2-pentynoic acid ethyl ester, 2-pentynoic acid propyl ester, 2-pentynoic acid vinyl ester, 2-pentynoic acid 2-propenyl ester, 2-pentynoic acid Monocarboxylic acid esters such as 2-butenyl pentynoate, 3-butenyl pentynoate, methyl 3-pentynoate, ethyl 3-pentynoate, propyl 3-pentynoate, vinyl 3-pentynoate, 2-propenyl pentynoate, 2-butenyl pentynoate, 3-butenyl pentynoate, methyl 4-pentynoate, ethyl 4-pentynoate, propyl 4-pentynoate, vinyl 4-pentynoate, 2-propenyl pentynoate, 2-butenyl pentynoate, and 3-butenyl pentynoate, fumarate esters, methyl pivalate, and ethyl pivalate;

[0614] dicarboxylic acid esters such as 2-butyne-1,4-diol diacetate, 2-butyne-1,4-diol dipropionate, 2-butyne-1,4-diol dibutyrate, 2-butyne-1,4-diol dibenzoate, 2-butyne-1,4-diol dicyclohexanecarboxylate, hexahydrobenzo[1,3,2]dioxathiolane-2-oxide (1,2-cyclohexanediol, 2,2-dioxo-1,2-oxathiolane-4-yl acetate, 2,2-dioxo-1,2-oxathiolane-4-yl acetate;

[0615] Oxalic acid diesters such as 2-propynyl methyl oxalate, 2-propynyl ethyl oxalate, 2-propynyl propyl oxalate, 2-propynyl vinyl oxalate, 2-propynyl allyl oxalate, di(2-propynyl) oxalate, 2-butynyl methyl oxalate, 2-butynyl ethyl oxalate, 2-butynyl propyl oxalate, 2-butynyl vinyl oxalate, 2-butynyl allyl oxalate, di(2-butynyl) oxalate, 3-butynyl methyl oxalate, 3-butynyl ethyl oxalate, 3-butynyl propyl oxalate, 3-butynyl vinyl oxalate, 3-butynyl allyl oxalate, and di(3-butynyl) oxalate;

[0616] Phosphine oxides such as methyl(2-propynyl)(vinyl)phosphine oxide, divinyl(2-propynyl)phosphine oxide, di(2-propynyl)(vinyl)phosphine oxide, di(2-propenyl)(2-propynyl)phosphine oxide, di(2-propenyl)(2-propynyl)phosphine oxide, di(3-butenyl)(2-propynyl)phosphine oxide, and di(2-propynyl)(3-butenyl)phosphine oxide;

[0617] 2-propynyl methyl (2-propenyl) phosphinate, 2-propynyl 2-butenyl (methyl) phosphinate, 2-propynyl di(2-propenyl) phosphinate, 2-propynyl di(3-butenyl) phosphinate, 1,1-dimethyl-2-propynyl methyl (2-propenyl) phosphinate, 1,1-dimethyl-2-propynyl 2-butenyl (methyl) phosphinate, 1,1-dimethyl-2-propynyl di(2-propenyl) phosphinate, and 1,1-dimethyl-2-propynyl di(3-butenyl) phosphinate.

[0618] Phosphinates such as 2-propynyl phosphite, 2-propenyl methyl (2-propynyl) phosphite, 3-butenyl methyl (2-propynyl) phosphite, 2-propenyl di (2-propynyl) phosphite, 3-butenyl di (2-propynyl) phosphite, 2-propenyl 2-propynyl (2-propenyl) phosphite, and 3-butenyl 2-propynyl (2-propenyl) phosphite;

[0619] 2-propenylphosphonic acid (methyl) (2-propynyl) ester, 2-butenylphosphonic acid (methyl) (2-propynyl) ester, 2-propenylphosphonic acid (2-propynyl) (2-propenyl) ester, 3-butenylphosphonic acid (3-butenyl) (2-propynyl) ester, 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl) ester, 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl) ester, 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl) ester, and 3-butenylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl) (2-propenyl) ester. Phosphonic acid esters such as (1,1-dimethyl-2-propynyl) (2-propenyl) methylphosphonate, (3-butenyl) (2-propenyl) (1,1-dimethyl-2-propynyl) (2-propenyl) methylphosphonate, (3-butenyl) (1,1-dimethyl-2-propynyl) (1,1-dimethyl-2-propynyl) methylphosphonate, (2-propynyl) (2-propenyl) ethylphosphonate, (3-butenyl) (2-propenyl) (1,1-dimethyl-2-propynyl) (2-propenyl) ethylphosphonate, (1,1-dimethyl-2-propynyl) (2-propenyl) ethylphosphonate and (3-butenyl) (1,1-dimethyl-2-propynyl) (1,1-dimethyl-2-propynyl) ethylphosphonate;

[0620] Phosphoric acid esters such as (methyl)(2-propenyl)(2-propynyl) phosphate, (ethyl)(2-propenyl)(2-propynyl) phosphate, (2-butenyl)(methyl)(2-propynyl) phosphate, (2-butenyl)(ethyl)(2-propynyl) phosphate, (1,1-dimethyl-2-propynyl)(methyl)(2-propenyl) phosphate, (1,1-dimethyl-2-propynyl)(ethyl)(2-propenyl) phosphate, (2-butenyl)(1,1-dimethyl-2-propynyl)(methyl) phosphate, and (2-butenyl)(ethyl)(1,1-dimethyl-2-propynyl) phosphate;

[0621] Among these, compounds having an alkynyloxy group are preferred because they can form a negative electrode coating more stably in an electrolyte solution.

[0622] Furthermore, from the viewpoint of improving storage characteristics, compounds such as 2-propynyl methyl carbonate, di(2-propynyl) carbonate, 2-butyne-1,4-diol dimethyl dicarbonate, 2-propynyl acetate, 2-butyne-1,4-diol diacetate, 2-propynyl methyl oxalate, and di(2-propynyl) oxalate are particularly preferred.

[0623] The above-mentioned compound with triple bond can be used alone as one, or in any combination and ratio and in combination with two or more. The compound with triple bond is not limited in the amount of the electrolyte as a whole, as long as it does not significantly damage the effect of the present disclosure, and is generally 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and generally 5% by mass or less, preferably 3% by mass or less, and more preferably 1% by mass or less. When the above range is met, the effects of output characteristics, load characteristics, cycle characteristics, high temperature storage characteristics, etc. are further improved.

[0624] In order to effectively suppress battery rupture and fire when an electrochemical device using the electrolyte is overcharged or the like, an overcharge prevention agent may be used in the electrolyte.

[0625] Examples of the overcharge prevention agent include unsubstituted or alkyl-substituted terphenyl derivatives such as biphenyl, o-terphenyl, m-terphenyl, and p-terphenyl, partially hydrogenated products of unsubstituted or alkyl-substituted terphenyl derivatives, cyclohexylbenzene, tert-butylbenzene, tert-amylbenzene, diphenyl ether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindane, cyclopentylbenzene, cyclohexylbenzene, isopropylbenzene, 1,3-diisopropylbenzene, 1,4-diisopropylbenzene, tert-butylbenzene, tert-amylbenzene, tert-hexylbenzene, and anisole; aromatic compounds such as 2-fluorobiphenyl, 4-fluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene, o-cyclohexylfluorobenzene, and p-cyclohexylfluorobenzene; Benzene, fluorotoluene, trifluorotoluene and other partially fluorinated aromatic compounds; 2,4-difluoroanisole, 2,5-difluoroanisole, 1,6-difluoroanisole, 2,6-difluoroanisole, 3,5-difluoroanisole and other fluorinated anisole compounds; 3-propylphenyl acetate, 2-ethylphenyl acetate, benzylphenyl acetate, methylphenyl acetate, benzyl acetate, phenethylphenyl acetate and other aromatic acetates; diphenyl carbonate, methylphenyl carbonate and other aromatic carbonates; toluene, xylene and other toluene derivatives; 2-methylbiphenyl, 3-methylbiphenyl, 4-methylbiphenyl, o-cyclohexylbiphenyl and other unsubstituted or alkyl-substituted biphenyl derivatives; Among them, preferred are aromatic compounds such as biphenyl, alkylbiphenyl, terphenyl, partial hydrogenation of terphenyl, cyclohexylbenzene, tert-butylbenzene, tert-amylbenzene, diphenyl ether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindane, 3-propylphenyl acetate, 2-ethylphenyl acetate, benzylphenyl acetate, methylphenyl acetate, benzyl acetate, diphenyl carbonate, methyl benzene carbonate, etc. They can be used alone or in combination of two or more. In the case of using two or more kinds in combination, in particular, from the viewpoint of the balance between the overcharge prevention characteristic and the high temperature storage characteristic, a combination of cyclohexylbenzene and tert-butylbenzene or tert-amylbenzene is preferred; or at least one of oxygen-free aromatic compounds selected from biphenyl, alkylbiphenyl, terphenyl, partial hydrogenation of terphenyl, cyclohexylbenzene, tert-butylbenzene, tert-amylbenzene, etc. and at least one of oxygen-containing aromatic compounds selected from diphenyl ether, dibenzofuran, etc. are used in combination.

[0626] In the electrolyte used in the present disclosure, carboxylic acid anhydride (but excluding compound (2)) may also be used. As the carboxylic acid anhydride, a compound represented by the following general formula (6) is preferred. The method for producing the carboxylic acid anhydride is not particularly limited, and any known method can be selected for production.

[0627] [Chemistry 56]

[0628]

[0629] (In general formula (6), R 61 , R 62Each independently represents a hydrocarbon group having 1 to 15 carbon atoms which may have a substituent.

[0630] R 61 , R 62 As long as it is a monovalent hydrocarbon group, its type is not particularly limited. For example, it can be an aliphatic hydrocarbon group, it can also be an aromatic hydrocarbon group, and it can also be a group formed by bonding an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group can be a saturated hydrocarbon group, and it can also contain an unsaturated bond (carbon-carbon double bond or carbon-carbon triple bond). In addition, the aliphatic hydrocarbon group can be chain-shaped or cyclic, and in the case of a chain-shaped group, it can be straight-chain or branched. In addition, it can also be a group formed by bonding a chain-shaped group and a ring-shaped group. It should be noted that R 61 and R 62 They can be the same or different.

[0631] In addition, in R 61 , R 62 When the hydrocarbon group has a substituent, the type of the substituent is not particularly limited as long as it does not violate the main purpose of the present disclosure. Examples include halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, preferably fluorine atoms. Alternatively, as substituents other than halogen atoms, substituents having functional groups such as ester groups, cyano groups, carbonyl groups, and ether groups may be mentioned, preferably cyano groups and carbonyl groups. 61 , R 62 The hydrocarbon group may have only one of the above-mentioned substituents, or may have two or more. When having two or more substituents, these substituents may be the same or different from each other.

[0632] R 61 , R 62 The number of carbon atoms of each hydrocarbon group is usually 1 or more and usually 15 or less, preferably 12 or less, more preferably 10 or less, and further preferably 9 or less. 61 With R 62 When the two hydrocarbon groups are bonded to each other to form a divalent hydrocarbon group, the number of carbon atoms in the divalent hydrocarbon group is usually 1 or more and usually 15 or less, preferably 13 or less, more preferably 10 or less, and further preferably 8 or less. 61 , R 62 When the hydrocarbon group has a substituent containing a carbon atom, it is preferred that R including the substituent 61 , R 62 The total number of carbon atoms satisfies the above range.

[0633] Next, specific examples of the acid anhydride represented by the above general formula (6) are described. It should be noted that in the following examples, "analogs" refer to acid anhydrides obtained by replacing a part of the structure of the exemplified acid anhydride with other structures within the scope of the present disclosure, for example, dimers, trimers and tetramers composed of multiple acid anhydrides, or substances with the same number of carbon atoms of the substituent but with structural isomers such as branched chains, substances with different positions of the substituent bonded to the acid anhydride, etc.

[0634] First, the following is an example of R 61 , R 62 Specific examples of the same acid anhydride.

[0635] As R 61 , R 62 Specific examples of the acid anhydride having a chain alkyl group include acetic anhydride, propionic anhydride, butyric anhydride, 2-methylpropionic anhydride, 2,2-dimethylpropionic anhydride, 2-methylbutyric anhydride, 3-methylbutyric anhydride, 2,2-dimethylbutyric anhydride, 2,3-dimethylbutyric anhydride, 3,3-dimethylbutyric anhydride, 2,2,3-trimethylbutyric anhydride, 2,3,3-trimethylbutyric anhydride, 2,2,3,3-tetramethylbutyric anhydride, 2-ethylbutyric anhydride, and the like, and analogs thereof.

[0636] As R 61 , R 62 Specific examples of the acid anhydride having a cyclic alkyl group include cyclopropanecarboxylic anhydride, cyclopentanecarboxylic anhydride, cyclohexanecarboxylic anhydride, and the like, and analogs thereof.

[0637] As R 61 , R 62 Specific examples of the acid anhydride which is an alkenyl group include acrylic anhydride, 2-methacrylic anhydride, 3-methacrylic anhydride, 2,3-dimethylacrylic anhydride, 3,3-dimethylacrylic anhydride, 2,3,3-trimethylacrylic anhydride, 2-phenylacrylic anhydride, 3-phenylacrylic anhydride, 2,3-diphenylacrylic anhydride, 3,3-diphenylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, 2,2-dimethyl-3-butenoic anhydride, 3-methyl-3-butenoic anhydride, 2-methyl-3-methyl-3-butenoic anhydride, 2,2-dimethyl-3-methyl-3-butenoic anhydride, 3-pentenoic anhydride, 4-pentenoic anhydride, 2-cyclopentenecarboxylic anhydride, 3-cyclopentenecarboxylic anhydride, 4-cyclopentenecarboxylic anhydride, and analogs thereof.

[0638] As R 61 , R 62 Specific examples of the acid anhydride which is an alkynyl group include propiolic anhydride, 3-phenylpropiolic anhydride, 2-butynoic anhydride, 2-pentynoic anhydride, 3-butynoic anhydride, 3-pentynoic anhydride, 4-pentynoic anhydride and the like, and analogs thereof.

[0639] As R 61 , R 62 Specific examples of the acid anhydride which is an aryl group include benzoic anhydride, 4-methylbenzoic anhydride, 4-ethylbenzoic anhydride, 4-tert-butylbenzoic anhydride, 2-methylbenzoic anhydride, 2,4,6-trimethylbenzoic anhydride, 1-naphthoic anhydride, 2-naphthoic anhydride, and the like, and analogs thereof.

[0640] In addition, as R 61 , R 62 Examples of acid anhydrides substituted with halogen atoms include acid anhydrides mainly substituted with fluorine atoms. However, acid anhydrides obtained by replacing part or all of these fluorine atoms with chlorine atoms, bromine atoms or iodine atoms are also included in the exemplified compounds.

[0641] As R 61 , R 62 Examples of the acid anhydride of the chain alkyl group substituted with a halogen atom include fluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, 2-fluoropropionic anhydride, 2,2-difluoropropionic anhydride, 2,3-difluoropropionic anhydride, 2,2,3-trifluoropropionic anhydride, 2,3,3-trifluoropropionic anhydride, 2,2,3,3-tetrapropionic anhydride, 2,3,3,3-tetrapropionic anhydride, 3-fluoropropionic anhydride, 3,3-difluoropropionic anhydride, 3,3,3-trifluoropropionic anhydride, perfluoropropionic anhydride, and the like, and analogs thereof.

[0642] As R 61 , R 62 Examples of the acid anhydride of a cyclic alkyl group substituted with a halogen atom include 2-fluorocyclopentanecarboxylic anhydride, 3-fluorocyclopentanecarboxylic anhydride, 4-fluorocyclopentanecarboxylic anhydride, and the like, and analogs thereof.

[0643] As R 61 , R 62 Examples of the acid anhydride of the alkenyl group substituted with a halogen atom include 2-fluoroacrylic anhydride, 3-fluoroacrylic anhydride, 2,3-difluoroacrylic anhydride, 3,3-difluoroacrylic anhydride, 2,3,3-trifluoroacrylic anhydride, 2-(trifluoromethyl)acrylic anhydride, 3-(trifluoromethyl)acrylic anhydride, 2,3-bis(trifluoromethyl)acrylic anhydride, 2,3,3-tri(trifluoromethyl)acrylic anhydride, 2-(4-fluorophenyl)acrylic anhydride, 3-(4-fluorophenyl)acrylic anhydride, 2,3-bis(4-fluorophenyl)acrylic anhydride, 3,3-bis(4-fluorophenyl)acrylic anhydride, 2-fluoro-3-butenoic anhydride, 2,2-difluoro-3-butenoic anhydride, 3-fluoro-2-butenoic anhydride, 4-fluoro-3-butenoic anhydride, 3,4-difluoro-3-butenoic anhydride, 3,3,4-trifluoro-3-butenoic anhydride, and analogs thereof.

[0644] As R 61, R 62 Examples of the anhydride of the alkynyl group substituted with a halogen atom include 3-fluoro-2-propiolic anhydride, 3-(4-fluorophenyl)-2-propiolic anhydride, 3-(2,3,4,5,6-pentafluorophenyl)-2-propiolic anhydride, 4-fluoro-2-butynoic anhydride, 4,4-difluoro-2-butynoic anhydride, 4,4,4-trifluoro-2-butynoic anhydride, and the like, and analogs thereof.

[0645] As R 61 , R 62 Examples of the acid anhydride of the aryl group substituted with a halogen atom include 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, 4-trifluoromethylbenzoic anhydride, and the like, and analogs thereof.

[0646] As R 61 , R 62 Examples of acid anhydrides containing a substituent having a functional group such as an ester, nitrile, ketone, or ether include methoxyformic anhydride, ethoxyformic anhydride, methyl oxalic anhydride, ethyl oxalic anhydride, 2-cyanoacetic anhydride, 2-oxopropionic anhydride, 3-oxobutyric anhydride, 4-acetylbenzoic anhydride, methoxyacetic anhydride, 4-methoxybenzoic anhydride, and analogs thereof.

[0647] Next, the following is an example of R 61 , R 62 Specific examples of acid anhydrides that are different from each other.

[0648] As R 61 , R 62 , all combinations of the above-mentioned examples and their analogs can be considered, and representative examples are given below.

[0649] Examples of combinations of chain alkyl groups include acetic propionic anhydride, acetic butyric anhydride, butyric propionic anhydride, and acetic 2-methylpropionic anhydride.

[0650] Examples of the combination of a chain alkyl group and a cyclic alkyl group include acetic cyclopentane anhydride, acetic cyclohexane anhydride, and cyclopentane propionic anhydride.

[0651] Examples of the combination of a chain alkyl group and an alkenyl group include acetic anhydride, acetic anhydride-3-methacrylic anhydride, acetic anhydride-3-butenoic anhydride, and acrylic anhydride-propionic anhydride.

[0652] Examples of the combination of a chain alkyl group and an alkynyl group include acetic anhydride propiolic acid, acetic anhydride 2-butiolic acid, acetic anhydride 3-butiolic acid, acetic anhydride 3-phenylpropiolic acid, and propiolic anhydride.

[0653] Examples of the combination of a chain alkyl group and an aryl group include acetic anhydride benzoic acid, acetic 4-methylbenzoic acid, acetic 1-naphthoic acid, and benzoic acid propionic anhydride.

[0654] Examples of the combination of a chain alkyl group and a hydrocarbon group having a functional group include acetic fluoroacetic anhydride, acetic trifluoroacetic anhydride, acetic 4-fluorobenzoic anhydride, acetic fluoropropionic anhydride, acetic alkyl oxalic anhydride, acetic 2-cyanoacetic anhydride, acetic 2-oxopropionic anhydride, acetic methoxyacetic anhydride, methoxyacetic propionic anhydride, and the like.

[0655] Examples of combinations of cyclic alkyl groups include cyclopentanecarboxylic acid and cyclohexanecarboxylic anhydride.

[0656] Examples of the combination of a cyclic alkyl group and an alkenyl group include cyclopentane acrylic acid anhydride, 3-cyclopentane methacrylic acid anhydride, 3-cyclopentane butylene acrylic acid anhydride, and cyclohexane acrylic acid anhydride.

[0657] Examples of the combination of a cyclic alkyl group and an alkynyl group include propiolic acid cyclopentane anhydride, 2-butynoic acid cyclopentane anhydride, and propiolic acid cyclohexane anhydride.

[0658] Examples of the combination of a cyclic alkyl group and an aryl group include benzoic acid cyclopentane anhydride, 4-methylbenzoic acid cyclopentane anhydride, and benzoic acid cyclohexane anhydride.

[0659] Examples of the combination of a cyclic alkyl group and a hydrocarbon group having a functional group include fluoroacetic cyclopentanecarboxylic anhydride, cyclopentanecarboxylic trifluoroacetic anhydride, cyclopentanecarboxylic 2-cyanoacetic anhydride, cyclopentanecarboxylic methoxyacetic anhydride, and cyclohexanecarboxylic fluoroacetic anhydride.

[0660] Examples of combinations of alkenyl groups include acrylic acid 2-methacrylic anhydride, acrylic acid 3-methacrylic anhydride, acrylic acid 3-butenoic anhydride, and 2-methacrylic acid 3-methacrylic anhydride.

[0661] Examples of the combination of an alkenyl group and an alkynyl group include acrylic acid propiolic anhydride, acrylic acid 2-butynic anhydride, and 2-methacrylic acid propiolic anhydride.

[0662] Examples of the combination of an alkenyl group and an aryl group include acrylic acid benzoic anhydride, acrylic acid 4-methylbenzoic anhydride, and 2-methacrylic acid benzoic anhydride.

[0663] Examples of the combination of an alkenyl group and a hydrocarbon group having a functional group include acrylic acid fluoroacetic anhydride, acrylic acid trifluoroacetic anhydride, acrylic acid 2-cyanoacetic anhydride, acrylic acid methoxyacetic anhydride, and 2-methacrylic acid fluoroacetic anhydride.

[0664] Examples of combinations of alkynyl groups include propiolic acid 2-butynoic anhydride, propiolic acid 3-butynoic anhydride, and 2-butynoic acid 3-butynoic anhydride.

[0665] Examples of the combination of an alkynyl group and an aryl group include benzoic acid propiolic anhydride, 4-methylbenzoic acid propiolic anhydride, and benzoic acid 2-butynoic anhydride.

[0666] Examples of the combination of an alkynyl group and a hydrocarbon group having a functional group include propiolic acid fluoroacetic anhydride, propiolic acid trifluoroacetic anhydride, propiolic acid 2-cyanoacetic anhydride, propiolic acid methoxyacetic anhydride, and 2-butynoic acid fluoroacetic anhydride.

[0667] Examples of combinations of aryl groups include 4-methylbenzoic anhydride benzoic acid, 1-naphthoic anhydride benzoic acid, and 1-naphthoic anhydride 4-methylbenzoic acid.

[0668] Examples of the combination of an aryl group and a hydrocarbon group having a functional group include benzoic acid fluoroacetic anhydride, benzoic acid trifluoroacetic anhydride, benzoic acid 2-cyanoacetic anhydride, benzoic acid methoxyacetic anhydride, and 4-methylbenzoic acid fluoroacetic anhydride.

[0669] Examples of combinations of hydrocarbon groups having a functional group include fluoroacetic acid trifluoroacetic anhydride, fluoroacetic acid 2-cyanoacetic anhydride, fluoroacetic acid methoxyacetic anhydride, trifluoroacetic acid 2-cyanoacetic anhydride, and the like.

[0670] Among the acid anhydrides forming a chain structure, acetic anhydride, propionic anhydride, 2-methylpropionic anhydride, cyclopentanecarboxylic anhydride, cyclohexanecarboxylic anhydride, acrylic anhydride, 2-methacrylic anhydride, 3-methacrylic anhydride, 2,3-dimethylacrylic anhydride, 3,3-dimethylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, propiolic anhydride, 2-butynoic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, trifluoroacetic anhydride, 3,3,3 -trifluoropropionic anhydride, 2-(trifluoromethyl)acrylic anhydride, 2-(4-fluorophenyl)acrylic anhydride, 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, ethoxyformic anhydride; more preferably acrylic anhydride, 2-methacrylic anhydride, 3-methacrylic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, ethoxyformic anhydride.

[0671] These compounds form a film having excellent durability by appropriately forming a bond with lithium oxalate salt, and are particularly preferred from the viewpoint of being able to improve charge and discharge rate characteristics, input and output characteristics, and impedance characteristics after a durability test.

[0672] It should be noted that the molecular weight of the carboxylic anhydride is not limited and can be any as long as the effect of the present disclosure is not significantly impaired, and is usually 90 or more, preferably 95 or more; on the other hand, it is usually 300 or less, preferably 200 or less. If the molecular weight of the carboxylic anhydride is within the above range, the viscosity of the electrolyte can be suppressed from increasing, and the film density is optimized, so that the durability can be appropriately improved.

[0673] The method for producing the carboxylic anhydride is not particularly limited, and any known method can be selected to produce the carboxylic anhydride. The non-aqueous electrolyte solution of the present disclosure may contain any one of the carboxylic anhydrides described above, or two or more of them may be contained in any combination and ratio.

[0674] The content of the above-mentioned carboxylic anhydride relative to the electrolyte is not particularly limited, and can be arbitrary as long as it does not significantly damage the effect of the present disclosure. It is expected to contain a concentration of usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less relative to the electrolyte. If the content of the carboxylic anhydride is within the above range, it is easy to play the effect of improving the cycle characteristics, and the reactivity is good, therefore, it is easy to improve the battery characteristics.

[0675] The electrolyte may contain other known additives. Examples of other additives include hydrocarbon compounds such as pentane, heptane, octane, nonane, decane, cycloheptane, benzene, furan, naphthalene, 2-phenylbicyclohexane, cyclohexane, 2,4,8,10-tetraoxaspiro[5.5]undecane, and 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane;

[0676] Fluorinated aromatic compounds such as fluorobenzene, difluorobenzene, hexafluorobenzene, trifluorotoluene, monofluorobenzene, 1-fluoro-2-cyclohexylbenzene, 1-fluoro-4-tert-butylbenzene, 1-fluoro-3-cyclohexylbenzene, 1-fluoro-2-cyclohexylbenzene, and fluorobiphenyl;

[0677] Carbonate compounds such as erythritan carbonate, spirobis-dimethylene carbonate, and methoxyethyl-methyl carbonate;

[0678] Ether compounds such as dioxolane, dioxane, 2,5,8,11-tetraoxadodecane, 2,5,8,11,14-pentaoxapentadecane, ethoxymethoxyethane, trimethoxymethane, glyme, and ethyl monoglyme;

[0679] Ketone compounds such as dimethyl ketone, diethyl ketone, 3-pentanone, etc.

[0680] Anhydrides such as 2-allylsuccinic anhydride;

[0681] Ester compounds such as dimethyl oxalate, diethyl oxalate, ethyl methyl oxalate, di(2-propynyl) oxalate, methyl 2-propynyl oxalate, dimethyl succinate, di(2-propynyl) glutarate, methyl formate, ethyl formate, 2-propynyl formate, 2-butyne-1,4-diyl dicarboxylate, 2-propynyl methacrylate, and dimethyl malonate;

[0682] Acetamide, N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide and other amide compounds;

[0683] Ethylene sulfate, vinylene sulfate, ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, cyclobutene sulfone, diphenyl sulfone, N,N-dimethyl methanesulfonamide, N,N-diethyl methanesulfonamide, methyl vinylsulfonate, ethyl vinylsulfonate, allyl vinylsulfonate, propargyl vinylsulfonate, methyl allylsulfonate, ethyl allylsulfonate, allylsulfonate, propargyl allylsulfonate, 1,2-bis(vinylsulfonyloxy)ethane, propanedisulfonic anhydride, sulfobutyric anhydride, sulfobenzoic anhydride, sulfopropionic anhydride, ethanedisulfonic anhydride, methylene methanedisulfonate, 2-propynyl methanesulfonate, amyl sulfite, pentafluorophenyl methanesulfonate, propylene sulfate, propylene sulfite, propane sultone, butylene sulfite, (butylenesulfonate sulfur-containing compounds such as 2-(2-(methylsulfonyloxy)propionic acid 2-propynyl ester, 5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, 3-sulfo-propionic anhydride methanedisulfonic acid trimethylene ester 2-methyltetrahydrofuran, methanedisulfonic acid trimethylene ester, tetramethylene sulfoxide, methanedisulfonic acid dimethylene ester, difluoroethyl methyl sulfone, divinyl sulfone, 1,2-bis(vinylsulfonyl)ethane, methyl ethanedisulfonate, ethyl ethanedisulfonate, ethylene sulfate, thiophene-1-oxide, etc.;

[0684] Nitrogen-containing compounds such as 1-methyl-2-pyrrolidone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone, N-methylsuccinimide, nitromethane, nitroethane, and ethylenediamine;

[0685] Trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, dimethyl vinylphosphonate, diethyl vinylphosphonate, ethyl diethylphosphonoacetate, methyl dimethylphosphinate, ethyl diethylphosphinate, trimethylphosphine oxide, triethylphosphine oxide, bis(2,2-difluoroethyl) 2,2,2-trifluoroethyl phosphate, bis(2,2,3,3-tetrafluoropropyl) 2,2,2-trifluoroethyl phosphate Fluoroethyl ester, 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, tributyl phosphate, tri(2,2,2-trifluoroethyl) phosphate, tri(1,1,1,3,3,3-hexafluoropropane-2-yl) phosphate, trioctyl phosphate, 2-phenylphenyl dimethyl phosphate , 2-phenylphenyl diethyl phosphate, (2,2,2-trifluoroethyl) (2,2,3,3-tetrafluoropropyl) methyl phosphate, 2-(dimethoxyphosphoryl) methyl acetate, 2-(dimethylphosphoryl) methyl acetate, 2-(diethoxyphosphoryl) methyl acetate, 2-(diethylphosphoryl) methyl acetate, methylene bisphosphonic acid methyl, methylene bisphosphonic acid ethyl, ethylene bisphosphonic acid methyl, ethylene bisphosphonic acid ethyl, butylene bisphosphonic acid methyl, butylene bisphosphonic acid ethyl, 2- Phosphorus-containing compounds such as (dimethoxyphosphoryl)acetate 2-propynyl, 2-(dimethylphosphoryl)acetate 2-propynyl, 2-(diethoxyphosphoryl)acetate 2-propynyl, 2-(diethylphosphoryl)acetate 2-propynyl, tris(trimethylsilyl)phosphate, tris(triethylsilyl)phosphate, tris(trimethoxysilyl)phosphate, tris(trimethylsilyl)phosphite, tris(triethylsilyl)phosphite, tris(trimethoxysilyl)phosphite, and trimethylsilyl polyphosphate;

[0686] Boron-containing compounds such as tris(trimethylsilyl) borate and tris(trimethoxysilyl) borate;

[0687] Silane compounds such as bis(trimethyl)aluminum orthosilicate, bis(triethyl)aluminum orthosilicate, bis(propanol)triethylaluminum orthosilicate, bis(butanol)trimethylaluminum orthosilicate, bis(trimethylsiloxy)titanium, tetra(triethylsiloxy)titanium, and tetramethylsilane;

[0688] Etc. These may be used alone or in combination of two or more. By adding these auxiliary agents, the capacity retention characteristics after high temperature storage and the cycle characteristics can be improved.

[0689] As the above-mentioned other auxiliary agents, phosphorus-containing compounds are preferred, and tris(trimethylsilyl) phosphate and tris(trimethylsilyl) phosphite are preferred.

[0690] The amount of other auxiliary agents is not particularly limited, and any amount can be used as long as the effect of the present disclosure is not significantly impaired. The amount of other auxiliary agents in 100% by mass of the electrolyte is preferably 0.01% by mass or more, and 5% by mass or less. As long as it is within this range, it is easy to fully demonstrate the effects of other auxiliary agents, and it is also easy to avoid situations such as reduced battery characteristics such as high-load discharge characteristics. The amount of other auxiliary agents is more preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and more preferably 3% by mass or less, and more preferably 1% by mass or less.

[0691] Without prejudice to the effects of the present invention, the electrolyte may further contain cyclic and chain carboxylates, ether compounds (excluding compounds (1) and (2)), nitrogen-containing compounds, boron-containing compounds, organic silicon compounds, non-flammable (flame retardant) agents, surfactants, high dielectric constant additives, cycle characteristics and rate characteristics improvers, sulfone compounds, etc. as additives.

[0692] Examples of the cyclic carboxylic acid ester include cyclic carboxylic acid esters having a total carbon atom count of 3 to 12 in the structural formula. Specifically, examples include γ-butyrolactone, γ-valerolactone, γ-caprolactone, ε-caprolactone, and 3-methyl-γ-butyrolactone. Among them, γ-butyrolactone is particularly preferred from the viewpoint of improving the characteristics of the electrochemical device due to an increase in the degree of lithium ion dissociation.

[0693] As the amount of the cyclic carboxylic acid ester of the additive, it is usually preferably 0.1% by mass or more in 100% by mass of the solvent, more preferably 1% by mass or more. If it is within this range, it is easy to improve the conductivity of the electrolyte and improve the large current discharge characteristics of the electrochemical device. In addition, the amount of the cyclic carboxylic acid ester is preferably 10% by mass or less, more preferably 5% by mass or less. By setting the upper limit like this, it is easy to make the viscosity of the electrolyte within an appropriate range, avoid the reduction of conductivity, suppress the increase of the negative electrode resistance, and make the large current discharge characteristics of the electrochemical device within a good range.

[0694] In addition, as the above-mentioned cyclic carboxylic acid ester, a fluorinated cyclic carboxylic acid ester (fluorinated lactone) can also be used appropriately. As the fluorinated lactone, for example, the following formula (C) can be mentioned:

[0695] [Chemistry 57]

[0696]

[0697] (Where X 15 ~X 20 The same or different, all are -H, -F, -Cl, -CH 3 or a fluoroalkyl group; wherein X 15 ~X20 At least one of which is a fluorinated alkyl group)

[0698] The fluorinated lactones shown.

[0699] As X 15 ~X 20 The fluoroalkyl group in the formula (a) includes, for example, -CFH 2 , -CF 2 H, -CF 3 、-CH 2 CF 3 , -CF 2 CF 3 、-CH 2 CF 2 CF 3 ,-CF(CF 3 ) 2 From the viewpoint of high oxidation resistance and improved safety, -CH 2 CF 3 、-CH 2 CF 2 CF 3 .

[0700] If X 15 ~X 20 At least one of -H, -F, -Cl, -CH 3 Or fluoroalkyl can be 15 ~X 20 The substitution may be performed at only one site or at multiple sites. From the viewpoint of good solubility of the electrolyte salt, the substitution is preferably performed at 1 to 3 sites, and more preferably at 1 to 2 sites.

[0701] The substitution position of the fluoroalkyl group is not particularly limited, but from the viewpoint of good synthesis yield, X 17 and / or X 18 , especially X 17 or X 18 is a fluoroalkyl group, preferably -CH 2 CF 3 、-CH 2 CF 2 CF 3 . X other than fluoroalkyl 15 ~X 20 is -H, -F, -Cl or CH 3 In particular, from the viewpoint of good solubility of the electrolyte salt, -H is preferred.

[0702] As the fluorine-containing lactone, in addition to the fluorine-containing lactone represented by the above formula, for example, the following formula (D) can also be mentioned:

[0703] [Chemistry 58]

[0704]

[0705] (In the formula, either A or B is CX 226 X 227 (X 226 and X 227 The same or different, all are -H, -F, -Cl, -CF 3 、-CH 3 or an alkylene group which may contain heteroatoms in the chain and in which the hydrogen atom may be replaced by a halogen atom), and the other is an oxygen atom; Rf 12 is a fluorinated alkyl or fluorinated alkoxy group which may have an ether bond; X 221 and X 222 The same or different, all are -H, -F, -Cl, -CF 3 or CH 3 ;X 223 ~X 225 The same or different, all are -H, -F, -Cl or an alkyl group in which the hydrogen atom may be replaced by a halogen atom and may contain a heteroatom in the chain; n = 0 or 1)

[0706] The fluorinated lactones shown.

[0707] As the fluorine-containing lactone represented by formula (D), the following formula (E) is preferably mentioned from the viewpoint of easy synthesis and good chemical stability:

[0708] [Chemistry 59]

[0709]

[0710] (In the formula, A, B, Rf 12 , X 221 , X 222 and X 223 Same as formula (D)

[0711] The 5-membered ring structure shown; further, according to the combination of A and B, there is the following formula (F):

[0712] [Chemistry 60]

[0713]

[0714] (Where Rf 12 , X 221 , X 222 , X 223 , X 226 and X 227 Same as formula (D)

[0715] The fluorinated lactone shown, and the following formula (G):

[0716] [Chemistry 61]

[0717]

[0718] (Where Rf 12 , X 221 , X 222 , X 223 , X 226 and X 227 Same as formula (D)

[0719] The fluorinated lactones shown.

[0720] Among these substances, from the viewpoint of being able to exert excellent properties such as high dielectric constant and high withstand voltage, and improving the properties of the electrolyte solution in the present disclosure in terms of good solubility of the electrolyte salt and effective reduction of the internal resistance, the following can be cited:

[0721] [Chemistry 62]

[0722]

[0723] wait.

[0724] By containing a fluorinated cyclic carboxylic acid ester, effects such as improvement in ion conductivity, improvement in safety, and improvement in stability at high temperatures can be obtained.

[0725] Examples of the chain carboxylic acid ester include chain carboxylic acid esters having a total carbon atom count of 3 to 7 in the structural formula. Specifically, examples include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isobutyl propionate, n-butyl propionate, methyl butyrate, isobutyl propionate, tert-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, n-propyl isobutyrate, isopropyl isobutyrate, and the like.

[0726] Among them, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, methyl butyrate, ethyl butyrate, and the like are preferred from the viewpoint of improving ion conductivity by reducing viscosity.

[0727] As the ether compound, chain ethers having 2 to 10 carbon atoms and cyclic ethers having 3 to 6 carbon atoms are preferred.

[0728] Examples of the chain ether having 2 to 10 carbon atoms include dimethyl ether, diethyl ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, diethoxymethane, dimethoxyethane, methoxyethoxyethane, diethoxyethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol, diethylene glycol dimethyl ether, pentaethylene glycol, triethylene glycol dimethyl ether, triethylene glycol, tetraethylene glycol, tetraethylene glycol dimethyl ether, and diisopropyl ether.

[0729] Examples of the cyclic ether having 3 to 6 carbon atoms include 1,2-dioxane, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1,4-dioxane, trioxane, 2-methyl-1,3-dioxolane, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 2-(trifluoroethyl)dioxolane, 2,2-bis(trifluoromethyl)-1,3-dioxolane, and fluorinated compounds thereof. Among them, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether, and crown ether are preferred in terms of high solvating ability for lithium ions and improved ion dissociation degree; dimethoxymethane, diethoxymethane, and ethoxymethoxymethane are particularly preferred in terms of low viscosity and providing high ion conductivity.

[0730] Examples of the nitrogen-containing compound include nitrile, fluorine-containing nitrile, carboxylic acid amide, fluorine-containing carboxylic acid amide, sulfonic acid amide, fluorine-containing sulfonic acid amide, acetamide, formamide, etc. In addition, 1-methyl-2-pyrrolidone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone, and N-methylsuccinimide, etc., can also be used. However, the nitrile compounds represented by the general formulas (1a), (1b), and (1c) are not included in the nitrogen-containing compound.

[0731] Examples of the boron-containing compound include boric acid esters such as trimethyl borate and triethyl borate, boric acid ethers, and alkylboranes.

[0732] Examples of the organic silicon-containing compound include (CH 3 ) 4 -Si, (CH 3 ) 3 -Si-Si(CH 3 ) 3 , silicone oil, etc.

[0733] As the above-mentioned incombustible (flame retardant) agent, phosphate ester or phosphazene compound can be cited. As the above-mentioned phosphate ester, for example, fluorine-containing alkyl phosphate, non-fluorine-based alkyl phosphate, aryl phosphate, etc. can be cited. Among them, fluorine-containing alkyl phosphate is preferred in terms of being able to exert a non-combustible effect in a small amount.

[0734] Examples of the phosphazene compounds include methoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, dimethylaminopentafluorocyclotriphosphazene, diethylaminopentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, and ethoxyheptafluorocyclotetraphosphazene.

[0735] Specific examples of the fluorine-containing alkyl phosphate include fluorine-containing dialkyl phosphate disclosed in Japanese Patent Application Laid-Open No. 11-233141, cyclic alkyl phosphate disclosed in Japanese Patent Application Laid-Open No. 11-283669, and fluorine-containing trialkyl phosphate.

[0736] As the above-mentioned flame retardant, preferably (CH 3 O) 3 P=O、(CF 3 CH 2 O) 3 P=O、(HCF 2 CH 2 O) 3 P=O、(CF 3 CF 2 CH 2 ) 3 P=O、(HCF 2 CF 2 CH 2 ) 3 P=O, etc.

[0737] The surfactant may be any of a cationic surfactant, anionic surfactant, nonionic surfactant, and amphoteric surfactant. From the viewpoint of good cycle characteristics and rate characteristics, a surfactant containing a fluorine atom is preferred.

[0738] As such a fluorine atom-containing surfactant, for example, the following formula (30) is preferred:

[0739] R 5 COO - M + (30)

[0740] (Where Rf 5 M is a fluorinated alkyl group having 3 to 10 carbon atoms and may contain an ether bond; + For Li + 、N a + , K + or NHR′ 3 + (R' is the same or different, and is H or an alkyl group with 1 to 3 carbon atoms))

[0741] The fluorinated carboxylate shown in the following formula (40):

[0742] R 6 SO 3 - M + (40)

[0743] (Where Rf 6 M is a fluorinated alkyl group having 3 to 10 carbon atoms and may contain an ether bond; + For Li + 、N a + , K + or NHR′ 3 + (R' is the same or different, and is H or an alkyl group with 1 to 3 carbon atoms))

[0744] Fluorinated sulfonates, etc.

[0745] The content of the surfactant in the electrolyte is preferably 0.01 to 2% by mass from the viewpoint of being able to reduce the surface tension of the electrolyte without reducing the charge-discharge cycle characteristics.

[0746] Examples of the dielectric constant-enhancing additive include sulfolane, methyl sulfolane, γ-butyrolactone, and γ-valerolactone.

[0747] Examples of the cycle characteristics and rate characteristics improving agent include methyl acetate, ethyl acetate, tetrahydrofuran, and 1,4-dioxane.

[0748] In addition, the above electrolyte solution may be further combined with a polymer material to form a gel electrolyte solution in a gel state (plasticized).

[0749] As such polymer materials, there can be cited conventionally known polyoxyethylene, polyoxypropylene, and their modified bodies (Japanese Patent Publication No. 8-222270, Japanese Patent Publication No. 2002-100405); polyacrylate polymers, polyacrylonitrile, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer and other fluororesins (Japanese Patent Publication No. 4-506726, Japanese Patent Publication No. 8-507407, Japanese Patent Publication No. 10-294131); composites of these fluororesins and hydrocarbon resins (Japanese Patent Publication No. 11-35765, Japanese Patent Publication No. 11-86630), etc. In particular, polyvinylidene fluoride and vinylidene fluoride-hexafluoropropylene copolymer are preferably used as polymer materials for gel electrolytes.

[0750] The above-mentioned electrolyte solution may contain an ion-conductive compound described in Japanese Patent Application No. 2004-301934.

[0751] The ion-conductive compound is an amorphous fluorinated polyether compound having a fluorinated group in a side chain represented by formula (101):

[0752] A-(D)-B(101)

[0753] [Wherein, D is formula (201):

[0754] -(D1) n -(FAE) m -(AE) p -(Y) q -(201)

[0755] (wherein D1 is an ether unit having a fluorine-containing ether group in the side chain represented by formula (2a):

[0756] [Chemistry 63]

[0757]

[0758] (wherein, Rf is a fluorinated ether group that may have a crosslinkable functional group, R 10 is a group or bond that bonds Rf to the main chain);

[0759] FAE is an ether unit having a fluorinated alkyl group in the side chain represented by formula (2b):

[0760] [Chemistry 64]

[0761]

[0762] (wherein, Rfa is a hydrogen atom or a fluoroalkyl group which may have a crosslinkable functional group; R 11 is a group or bond that bonds Rfa to the main chain);

[0763] AE is an ether unit represented by formula (2c):

[0764] [Chemistry 65]

[0765]

[0766] (Where R 13 is a hydrogen atom, an alkyl group which may have a crosslinkable functional group, an aliphatic cyclic hydrocarbon group which may have a crosslinkable functional group, or an aromatic hydrocarbon group which may have a crosslinkable functional group; R 12 To R 13 Groups or bonds bonded to the main chain);

[0767] Y is a unit comprising at least one of the formulae (2d-1) to (2d-3):

[0768] [Chemistry 66]

[0769]

[0770] n is an integer of 0 to 200; m is an integer of 0 to 200; p is an integer of 0 to 10000; q is an integer of 1 to 100; wherein n+m is not 0, and the bonding order of D1, FAE, AE and Y is not particularly specified);

[0771] A and B are the same or different and are a hydrogen atom, an alkyl group which may contain a fluorine atom and / or a crosslinking functional group, a phenyl group which may contain a fluorine atom and / or a crosslinking functional group, a -COOH group, -OR (R is a hydrogen atom or an alkyl group which may contain a fluorine atom and / or a crosslinking functional group), an ester group or a carbonate group (wherein, when the end of D is an oxygen atom, A and B are not -COOH groups, -OR, ester groups and carbonate groups)].

[0772] The electrolyte solution may contain a sulfone compound. The sulfone compound is preferably a cyclic sulfone having 3 to 6 carbon atoms and a chain sulfone having 2 to 6 carbon atoms. The number of sulfonyl groups in one molecule is preferably 1 or 2.

[0773] Examples of the cyclic sulfone include trimethylene sulfones, tetramethylene sulfones, and hexamethylene sulfones as monosulfone compounds, and trimethylene disulfones, tetramethylene disulfones, and hexamethylene disulfones as disulfone compounds. Among them, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones, and hexamethylene disulfones are more preferred from the viewpoint of dielectric constant and viscosity, and tetramethylene sulfones (sulfolanes) are particularly preferred.

[0774] As sulfolanes, sulfolane and / or sulfolane derivatives (hereinafter, including sulfolane, sometimes referred to as "sulfolanes") are preferred. As sulfolane derivatives, substances in which one or more of the hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are replaced by fluorine atoms or alkyl groups are preferred.

[0775] Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3-methylsulfolane, 4 -fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoromethylsulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethylsulfolane, 2-fluoro-3-(trifluoromethyl)sulfolane, 3-fluoro-3-(trifluoromethyl)sulfolane, 4-fluoro-3-(trifluoromethyl)sulfolane, 3-cyclobutene sulfolane, 5-fluoro-3-(trifluoromethyl)sulfolane, and the like.

[0776] Examples of the chain sulfone include dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, n-butyl methyl sulfone, n-butyl ethyl sulfone, tert-butyl methyl sulfone, tert-butyl ethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl Trifluoromethyl sulfone, perfluoroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, bis(trifluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl n-propyl sulfone, difluoromethyl n-propyl sulfone, trifluoromethyl n-propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl n-propyl sulfone, pentafluoroethyl isopropyl sulfone, trifluoroethyl n-butyl sulfone, trifluoroethyl tert-butyl sulfone, pentafluoroethyl n-butyl sulfone, pentafluoroethyl tert-butyl sulfone, etc.

[0777] Among them, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, tert-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, trifluoromethyl n-propyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl n-butyl sulfone, trifluoroethyl tert-butyl sulfone, trifluoromethyl n-butyl sulfone, trifluoromethyl tert-butyl sulfone and the like are preferred from the viewpoint of high ion conductivity and high input and output.

[0778] The content of the sulfone compound is not particularly limited, and can be any value as long as it does not significantly damage the effect of the present disclosure. In 100% by volume of the above-mentioned solvent, it is usually 0.3% by volume or more, preferably 0.5% by volume or more, and more preferably 1% by volume or more; and it is usually 40% by volume or less, preferably 35% by volume or less, and more preferably 30% by volume or less. If the content of the sulfone compound is within the above range, it is easy to obtain the effect of improving the durability such as the cycle characteristics and storage characteristics. In addition, the viscosity of the non-aqueous electrolyte can be within an appropriate range, the conductivity can be avoided from being reduced, and the input and output characteristics and the charge and discharge rate characteristics of the non-aqueous electrolyte secondary battery can be within an appropriate range.

[0779] From the viewpoint of improving output characteristics, the above-mentioned electrolyte preferably further comprises a lithium fluorophosphate salt selected from the group consisting of lithium fluorophosphate salts (excluding LiPF 6 ) and at least one compound (7) selected from lithium salts having an S═O group as an additive.

[0780] When the compound (7) is used as an additive, it is preferable to use a compound other than the compound (7) as the electrolyte salt.

[0781] Examples of the lithium fluorophosphate salts include lithium monofluorophosphate (LiPO 3 F), lithium difluorophosphate (LiPO 2 F 2 )wait.

[0782] Examples of the lithium salts having an S═O group include lithium monofluorosulfonate (FSO 3 Li), lithium methyl sulfate (CH 3 OSO 3 Li), lithium ethyl sulfate (C 2 H 5 OSO 3 Li), 2,2,2-trifluoroethyl lithium sulfate, etc.

[0783] Among the compounds (7), LiPO is preferred. 2 F 2 、FSO 3 Li, C 2 H 5 OSO 3 Li.

[0784] The content of the compound (7) is preferably 0.001 to 20% by mass, more preferably 0.01 to 15% by mass, further preferably 0.1 to 10% by mass, and particularly preferably 0.1 to 7% by mass, based on the above-mentioned electrolyte.

[0785] The electrolyte solution may further contain other additives as required. Examples of other additives include metal oxides and glass.

[0786] The electrolyte preferably contains 1 to 1000 ppm of hydrogen fluoride (HF). By containing HF, the film formation of the additive can be promoted. If the HF content is too little, the film forming ability on the negative electrode is reduced, and there is a tendency for the characteristics of the electrochemical device to be reduced. In addition, if the HF content is too much, there is a tendency for the oxidation resistance of the electrolyte to be reduced due to the influence of HF. Even if the composition disclosed herein contains HF in the above range, it will not reduce the high temperature storage capacity recovery rate of the electrochemical device.

[0787] The HF content is more preferably 5 ppm or more, further preferably 10 ppm or more, and particularly preferably 20 ppm or more. In addition, the HF content is more preferably 200 ppm or less, further preferably 100 ppm or less, further more preferably 80 ppm or less, and particularly preferably 50 ppm or less.

[0788] The HF content can be determined by neutralization titration.

[0789] The above-mentioned electrolyte solution can be prepared by any method using the above-mentioned components.

[0790] <Isolator>

[0791] The material and shape of the above-mentioned separator are not particularly limited as long as they are stable in the electrolyte and have excellent liquid retention, and known materials or shapes can be used. Among them, it is preferred that the separator is formed of a material that is stable to the composition (electrolyte) disclosed herein, and can use a porous sheet or non-woven fabric-like article with excellent liquid retention, such as resin, glass fiber, inorganic material, etc.

[0792] As materials for resin and glass fiber separators, polyolefins such as polyethylene and polypropylene, aromatic polyamides, polytetrafluoroethylene, polyethersulfone, glass filters, etc. can be used. Polypropylene / polyethylene double-layer membranes, polypropylene / polyethylene / polypropylene three-layer membranes, etc., these materials can be used alone or in any combination and ratio. Among them, considering the permeability of the electrolyte or the good shutdown effect, the above-mentioned separator is preferably a porous sheet or non-woven fabric made of polyolefins such as polyethylene and polypropylene as a raw material.

[0793] The thickness of the separator is arbitrary, but is usually 1 μm or more, preferably 5 μm or more, and more preferably 8 μm or more; and is usually 50 μm or less, preferably 40 μm or less, and more preferably 30 μm or less. If the separator is too thinner than the above range, the insulation and mechanical strength may be reduced. In addition, if it is too thicker than the above range, not only the battery performance such as rate characteristics may be reduced, but also the energy density of the electrolyte battery as a whole may be reduced.

[0794] Furthermore, when a porous material such as a porous sheet or nonwoven fabric is used as a separator, the porosity of the separator is arbitrary, but is usually 20% or more, preferably 35% or more, and more preferably 45% or more; and is usually 90% or less, preferably 85% or less, and more preferably 75% or less. If the porosity is too small than the above range, there is a tendency for the membrane resistance to increase and the rate characteristics to deteriorate. In addition, if it is too large than the above range, there is a tendency for the mechanical strength of the separator to decrease and the insulation to decrease.

[0795] In addition, the average pore size of the separator is also arbitrary, but is usually less than 0.5 μm, preferably less than 0.2 μm; and is usually greater than 0.05 μm. If the average pore size is larger than the above range, short circuits are likely to occur. In addition, if it is lower than the above range, the membrane resistance sometimes increases and the rate characteristics decrease.

[0796] On the other hand, as inorganic materials, for example, oxides such as aluminum oxide and silicon dioxide; nitrides such as aluminum nitride and silicon nitride; sulfates such as barium sulfate and calcium sulfate can be used, and materials in the form of particles or fibers can be used.

[0797] As the form, a non-woven fabric, a woven fabric, a microporous membrane or other thin film shape can be used. In the case of a thin film shape, a material with a pore size of 0.01 to 1 μm and a thickness of 5 to 50 μm is suitable. In addition to the above-mentioned independent thin film shape, a separator formed by forming a composite porous layer containing the above-mentioned inorganic particles on the surface of the positive electrode and / or the negative electrode using a resin binder can also be used. For example, a porous layer can be formed on both sides of the positive electrode using fluororesin as a binder to form aluminum oxide particles with a particle size of 90% less than 1 μm.

[0798] <Battery Design>

[0799] The electrode group may be any one of a stacked structure formed by sandwiching the positive electrode plate and the negative electrode plate with the separator, and a spirally wound structure formed by sandwiching the positive electrode plate and the negative electrode plate with the separator. The proportion of the volume of the electrode group in the internal volume of the battery (hereinafter referred to as the electrode group occupancy) is usually 40% or more, preferably 50% or more; and is usually 90% or less, preferably 80% or less.

[0800] If the occupancy rate of the electrode group is lower than the above range, the battery capacity becomes smaller. Additionally, if it is higher than the above range, the void space is less, and the components may expand due to the battery reaching a high temperature, or the vapor pressure of the liquid component of the electrolyte may become high, resulting in an increase in the internal pressure, reducing various characteristics such as the repeated charge-discharge performance and high-temperature storage of the battery, and sometimes even causing the vent valve used to release the internal pressure to operate.

[0801] The current collector structure is not particularly limited, but in order to more effectively achieve the effect of improving the charge-discharge characteristics at a high current density, a structure that reduces the resistance of the wiring part and the bonding part is preferably used.

[0802] In the case where the electrode group has the above-mentioned laminated structure, a structure formed by bundling the metal core parts of each electrode layer and welding them to the terminals is suitable. When the single-piece electrode area becomes larger, since the internal resistance becomes larger, it is also suitable to use a structure with multiple terminals provided inside the electrode to reduce the resistance. In the case where the electrode group has the above-mentioned wound structure, multiple lead structures are respectively provided on the positive electrode and the negative electrode, and the internal resistance can be reduced by bundling them to the terminals.

[0803] The material of the outer package case is not particularly limited as long as it is a substance stable with respect to the electrolyte used. Specifically, metal materials such as nickel-plated steel sheets, stainless steel, aluminum or aluminum alloys, and magnesium alloys can be used, or a laminated film (laminated film) of resin and aluminum foil. From the perspective of weight reduction, metals such as aluminum or aluminum alloys and laminated films are suitable.

[0804] In the case of using a metal outer package case, examples include an outer package case formed by laser welding, resistance welding, or ultrasonic welding to melt the metals together to form a sealed and airtight structure; or an outer package case formed by using the above-mentioned metal materials via a resin sealing gasket to form a caulking structure. In the case of using the above-mentioned laminated film as the outer package case, examples include an outer package case formed by heat-sealing the resin layers together to form a sealed and airtight structure. In order to improve the sealing performance, a resin different from the resin used in the laminated film can be sandwiched between the above-mentioned resin layers. In particular, when the resin layers are heat-sealed via the current collector terminal to form a sealed structure, a metal-resin joint is formed, so a resin having a polar group or a modified resin into which a polar group is introduced is suitable as the spacer resin.

[0805] The shape of the lithium-ion secondary battery is arbitrary, and examples include cylindrical, square, laminated, coin-shaped, and large-sized shapes. It should be noted that the shapes and configurations of the positive electrode, negative electrode, and separator can be changed according to the shape of each battery.

[0806] In addition, a lithium ion secondary battery having the following characteristics is also a preferred mode: having a positive electrode, a negative electrode, and the above-mentioned electrolyte, the above-mentioned positive electrode having a positive electrode current collector and a positive electrode active material layer containing a positive electrode active material, and the above-mentioned positive electrode active material contains Mn. Since it has a positive electrode active material layer containing a positive electrode active material containing Mn, the high temperature storage characteristics of the above-mentioned lithium ion secondary battery are further excellent.

[0807] As the Mn-containing positive electrode active material, LiMn is preferred from the viewpoint of being able to provide a lithium ion secondary battery with high energy density and high output. 1.5 Ni 0.5 O 4 、LiNi 0.5 Co 0.2 Mn 0.3 O 2 、LiNi 0.6 Co 0.2 Mn 0.2 O 2 .

[0808] In addition, as the above-mentioned Mn-containing positive electrode active material, LiNi is preferably used from the viewpoint of being able to provide a high-capacity lithium-ion secondary battery. 0.6 Co 0.2 Mn 0.2 O 2 、LiNi 0.8 Co 0.1 Mn 0.1 O 2 .

[0809] From the viewpoint of further improving the high temperature storage characteristics, the part of the lithium ion secondary battery electrically connected to the positive electrode current collector and in contact with the electrolyte is also preferably composed of a valve metal or its alloy. It is particularly preferred that the battery outer casing and the lead wire, safety valve, etc. contained in the battery outer casing are electrically connected to the positive electrode current collector and in contact with the non-aqueous electrolyte. Stainless steel coated with a valve metal or its alloy can be used.

[0810] The manufacturing method of the above-mentioned positive electrode is as described above, for example, the following method can be cited: adding the above-mentioned binder, thickener, conductive material, solvent, etc. to the above-mentioned positive electrode active material to prepare a slurry-like positive electrode mixture, applying it on the above-mentioned positive electrode collector, and pressing it after drying to achieve high density.

[0811] The negative electrode has the same structure as described above.

[0812] The above-mentioned lithium ion secondary battery can also be used as a module.

[0813] <Electric Double Layer Capacitor>

[0814] As described above, the current collecting foil and electrode disclosed in the present invention can also be used in an electric double layer capacitor.

[0815] The electric double layer capacitor may include a positive electrode, a negative electrode, and an electrolyte.

[0816] The electrolytic solution of the electric double layer capacitor contains a solvent and an electrolyte salt and may contain additives other than these.

[0817] The solvent and additives that can be used in the electrolyte for an electric double layer capacitor are the same as those described for the electrolyte for a battery.

[0818] As the electrolyte salt of the electrolytic solution for an electric double layer capacitor, an ammonium salt is preferable.

[0819] Examples of the ammonium salt include the following (IIa) to (IIe).

[0820] (IIa) Tetraalkyl quaternary ammonium salt

[0821] Preferred examples include general formula (IIa):

[0822] [Chemistry 67]

[0823]

[0824] (Where R 1a , R 2a , R 3a and R 4a The same or different, all of which are alkyl groups having 1 to 6 carbon atoms and may contain ether bonds; X - for anions)

[0825] In addition, from the viewpoint of improving oxidation resistance, an ammonium salt in which a part or all of the hydrogen atoms of the ammonium salt are replaced by fluorine atoms and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms is preferred.

[0826] As a specific example, general formula (IIa-1) can be cited:

[0827] [Chemistry 68]

[0828]

[0829] (Where R 1a , R 2a and X - Same as above; x and y are the same or different, and are integers from 0 to 4, and x+y=4)

[0830] The tetraalkyl quaternary ammonium salt shown, general formula (IIa-2):

[0831] [Chemistry 69]

[0832]

[0833] (Where R 5a is an alkyl group having 1 to 6 carbon atoms; R 6a is a divalent hydrocarbon group having 1 to 6 carbon atoms; R 7a is an alkyl group having 1 to 4 carbon atoms; z is 1 or 2; X - for anions)

[0834] The trialkylammonium salts containing an alkyl ether group shown above, etc.

[0835] By introducing an alkyl ether group, the viscosity can be reduced.

[0836] Anion X - It may be an inorganic anion or an organic anion. Examples of inorganic anions include AlCl 4 - , BF 4 - PF 6 - , AsF 6 - 、TaF 6 - ,I - , SbF 6 - Examples of the organic anion include bisoxalatoborate anion, difluorooxalatoborate anion, tetrafluorooxalatophosphate anion, difluorobisoxalatophosphate anion, CF 3 COO - CF 3 SO 3 - ,(CF 3 SO 2 ) 2 N - , (C 2 F 5 SO 2 ) 2 N - wait.

[0837] Among them, BF is preferred from the viewpoint of good oxidation resistance and ion dissociation property. 4 - PF 6 - , AsF 6 - , SbF 6 - .

[0838] As a preferred specific example of the tetraalkylammonium salt, Et 4 NBF 4 , Et 4 NClO 4 , Et 4 NPF 6 , Et 4 NAS 6 , Et 4 Nb 6 , Et 4 NCF 3 SO 3 , Et 4 N(CF 3 SO 2 ) 2 N、Et 4 NC 4 F 9 SO 3 , Et 3 M E 4 , Et 3 MeNC10 4 , Et 3 MeNPF 6 , Et 3 Mef 6 , Et 3 FWf 6 , Et 3 MeNCF 3 SO 3 , Et 3 MeN(CF 3 SO 2 ) 2 N、Et 3 MeNC 4 F 9 SO 3 , in particular Et 4 NBF 4 , Et 4 NPF 6 , Et 4 Nb 6 , Et 4 NAS 6 , Et 3 M E 4 , N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium salt, etc.

[0839] (IIb) Spirocyclic Bispyrrolidinium Salt

[0840] Preferably, the general formula (IIb-1) is:

[0841] [Chemistry 70]

[0842]

[0843] (Where R 8a and R 9a are the same or different and are all alkyl groups with 1 to 4 carbon atoms; - is an anion; n1 is an integer from 0 to 5; n2 is an integer from 0 to 5)

[0844] The spirocyclic bispyrrolidinium salt shown has the general formula (IIb-2):

[0845] [Chemistry 71]

[0846]

[0847] (Where R 10a and R 11a are the same or different and are all alkyl groups with 1 to 4 carbon atoms; - is an anion; n3 is an integer from 0 to 5; n4 is an integer from 0 to 5)

[0848] The spirocyclic bipyrrolidinium salt shown, or general formula (IIb-3):

[0849] [Chemistry 72]

[0850]

[0851] (Where R 12a and R 13a are the same or different and are all alkyl groups with 1 to 4 carbon atoms; - is an anion; n5 is an integer from 0 to 5; n6 is an integer from 0 to 5)

[0852] In addition, from the viewpoint of improving oxidation resistance, a spirobispyrrolidinium salt in which a part or all of the hydrogen atoms of the spirobispyrrolidinium salt are replaced by fluorine atoms and / or a fluorinated alkyl group having 1 to 4 carbon atoms is preferred.

[0853] Anion X - The preferred specific examples are the same as those of (IIa). Among them, BF is preferred from the viewpoint of high dissociation and low internal resistance at high voltage. 4 -PF 6 -、(CF 3 SO 2 ) 2 N-or (C 2 F 5 SO 2 ) 2 N-.

[0854] Preferred specific examples of the spirocyclic bispyrrolidinium salt include:

[0855] [Chemistry 73]

[0856]

[0857] wait.

[0858] The spirobispyrrolidinium salt is excellent in solubility in solvents, oxidation resistance, and ion conductivity.

[0859] (IIc) Imidazolium salt

[0860] Preferred examples include general formula (IIc):

[0861] [Chemistry 74]

[0862]

[0863] (Where R 14a and R 15a are the same or different and are all alkyl groups with 1 to 6 carbon atoms; - for anions)

[0864] In addition, from the viewpoint of improving oxidation resistance, an imidazolium salt in which a part or all of the hydrogen atoms of the imidazolium salt are replaced by fluorine atoms and / or a fluorinated alkyl group having 1 to 4 carbon atoms is preferred.

[0865] Anion X - Preferred specific examples are the same as those for (IIa).

[0866] As a preferred specific example, for example,

[0867] [Chemistry 75]

[0868]

[0869] wait.

[0870] This imidazolium salt is excellent in that it has low viscosity and good solubility.

[0871] (IId): N-alkylpyridinium salt

[0872] Preferred examples include general formula (IId):

[0873] [Chemistry 76]

[0874]

[0875] (Where R 16a is an alkyl group having 1 to 6 carbon atoms;- for anions)

[0876] In addition, from the viewpoint of improving oxidation resistance, N-alkylpyridinium salts in which a part or all of hydrogen atoms are replaced by fluorine atoms and / or fluorinated alkyl groups having 1 to 4 carbon atoms are preferred.

[0877] Anion X - Preferred specific examples are the same as those for (IIa).

[0878] As a preferred specific example, for example,

[0879] [Chemistry 77]

[0880]

[0881] wait.

[0882] This N-alkylpyridinium salt is excellent in that it has low viscosity and good solubility.

[0883] (IIe) N,N-Dialkylpyrrolidinium salt

[0884] Preferred examples include general formula (IIe):

[0885] [Chemistry 78]

[0886]

[0887] (Where R 17a and R 18a are the same or different and are all alkyl groups with 1 to 6 carbon atoms; - for anions)

[0888] In addition, from the viewpoint of improving oxidation resistance, N,N-dialkylpyrrolidinium salts in which a part or all of the hydrogen atoms of the N,N-dialkylpyrrolidinium salt are replaced by fluorine atoms and / or a fluorinated alkyl group having 1 to 4 carbon atoms are preferred.

[0889] Anion X - Preferred specific examples are the same as those for (IIa).

[0890] As a preferred specific example, for example,

[0891] [Chemistry 79]

[0892]

[0893] [Chemistry 80]

[0894]

[0895] wait.

[0896] The N,N-dialkylpyrrolidinium salt is excellent in terms of low viscosity and good solubility. Among these ammonium salts, (IIa), (IIb) and (IIc) are preferred from the perspective of good solubility, oxidation resistance and ion conductivity, and

[0897] [Chemistry 81]

[0898]

[0899] (wherein, Me is methyl; Et is ethyl; X - , x, y are the same as in formula (IIa-1)).

[0900] In addition, as the electrolyte salt for the electric double layer capacitor, a lithium salt can be used. As the lithium salt, for example, LiPF 6 , LiBF 4 、LiN(FSO 2 ) 2 、LiAsF 6 、LiSbF 6 、LiN(SO 2 C 2 H 5 ) 2 .

[0901] In order to further increase the capacity, magnesium salts may be used. As magnesium salts, for example, Mg(ClO 4 ) 2 Mg(OOC 2 H 5 ) 2 wait.

[0902] When the electrolyte salt is the above-mentioned ammonium salt, the concentration is preferably 0.7 mol / L or more. If it is less than 0.7 mol / L, not only the low temperature characteristics deteriorate, but also the initial internal resistance becomes high. The concentration of the above-mentioned electrolyte salt is more preferably 0.9 mol / L or more.

[0903] The upper limit of the concentration is preferably 2.0 mol / L or less, more preferably 1.5 mol / L or less, from the viewpoint of low-temperature characteristics.

[0904] In the case where the ammonium salt is triethylmethylammonium tetrafluoroborate (TEMABF 4 ), the concentration is preferably 0.7 to 1.5 mol / L from the viewpoint of excellent low temperature characteristics.

[0905] In addition, in the presence of spirobipyrrolidinium tetrafluoroborate (SBPBF 4), preferably 0.7 to 2.0 mol / L.

[0906] In the electric double layer capacitor, at least one of the positive electrode and the negative electrode is a polarizable electrode, and as the polarizable electrode and the unpolarized electrode, the following electrodes described in detail in Japanese Patent Application Laid-Open No. 9-7896 can be used.

[0907] The polarized electrode mainly composed of activated carbon used in the present invention preferably contains non-activated carbon with a large specific surface area and a conductive agent such as carbon black that imparts electronic conductivity. The polarized electrode can be formed by various methods. For example, activated carbon powder, carbon black and phenolic resin are mixed, and after compression molding, they are fired and activated in an inert gas atmosphere and a water vapor atmosphere, thereby forming a polarized electrode containing activated carbon and carbon black. Preferably, the polarized electrode is bonded to the current collector by a conductive adhesive or the like.

[0908] In addition, activated carbon powder, carbon black and a binder may be kneaded in the presence of alcohol to form a sheet, and dried to form a polarized electrode. The binder may be, for example, polytetrafluoroethylene. In addition, activated carbon powder, carbon black, a binder and a solvent may be mixed to form a slurry, and the slurry may be applied to a metal foil of a current collector, and dried to form a polarized electrode integrated with the current collector.

[0909] Polarized electrodes with activated carbon as the main body can be used for both poles to make a double-layer capacitor, or a non-polarized electrode can be used on one side, for example: a positive electrode with a battery active material such as a metal oxide as the main body and a negative electrode with activated carbon as the main body The polarized electrode is combined; a negative electrode with a carbon material that can reversibly absorb and release lithium ions as the main body, or a negative electrode of lithium metal or lithium alloy is combined with a polarized positive electrode with activated carbon as the main body.

[0910] In addition, carbonaceous materials such as carbon black, graphite, expanded graphite, porous carbon, carbon nanotubes, carbon nanohorns, and Ketjen black may be used in place of activated carbon or in combination with the activated carbon.

[0911] As the unpolarized electrode, it is preferred to use a carbon material that can reversibly absorb and release lithium ions as the main body, and the substance that absorbs lithium ions in the carbon material is used as the electrode. In this case, a lithium salt can be used as the electrolyte. According to the double-layer capacitor of this structure, a higher withstand voltage of more than 4V can be obtained.

[0912] The solvent used in the preparation of the slurry in the production of the electrode is preferably a solvent that can dissolve the binder, and N-methylpyrrolidone, dimethylformamide, toluene, xylene, isophorone, methyl ethyl ketone, ethyl acetate, methyl acetate, dimethyl phthalate, ethanol, methanol, butanol or water is appropriately selected to match the type of binder.

[0913] As the activated carbon used in the polarized electrode, there are phenolic resin activated carbon, coconut shell activated carbon, petroleum coke activated carbon, etc. Among these, from the viewpoint of being able to obtain a large capacity, preferably use petroleum coke activated carbon or phenolic resin activated carbon. In addition, among the activation treatment methods of activated carbon, there are steam activation treatment method, molten KOH activation treatment method, etc., and in terms of being able to obtain a larger capacity, preferably use the activated carbon obtained by the molten KOH activation treatment method.

[0914] As the preferred conductive agent used in the polarized electrode, carbon black, Ketjen black, acetylene black, natural graphite, artificial graphite, metal fiber, conductive titanium oxide, ruthenium oxide can be cited. Regarding the mixing amount of the conductive agent such as carbon black used in the polarized electrode, in order to obtain good conductivity (low internal resistance), and considering that if too much is mixed, the product capacity will decrease, it is preferably 1 to 50 mass % in the total amount with the activated carbon.

[0915] In order to obtain an electric double layer capacitor with a large capacity and low internal resistance, it is preferable to use activated carbon having an average particle size of 20 μm or less and a specific surface area of ​​1500 to 3000 m 2 / g of activated carbon. In addition, preferred carbon materials for forming electrodes based on carbon materials that can reversibly absorb and release lithium ions include natural graphite, artificial graphite, graphitized mesophase carbon spheres, graphitized whiskers, vapor-grown carbon fibers, sintered products of furfuryl alcohol resins, or sintered products of Novolak resins.

[0916] The current collector only needs to have chemical corrosion resistance and electrochemical corrosion resistance. As the current collector of the polarized electrode with activated carbon as the main body, stainless steel, aluminum, titanium or tantalum can be preferably used. Among these, stainless steel or aluminum is a particularly preferred material in terms of the characteristics and price of the obtained double-layer capacitor. As the current collector of the electrode with a carbon material that can reversibly absorb and detach lithium ions as the main body, stainless steel, copper or nickel is preferably used.

[0917] In addition, in order to allow a carbon material that can reversibly absorb and desorb lithium ions to absorb lithium ions in advance, the following methods exist: (1) a method of pre-mixing powdered lithium with a carbon material that can reversibly absorb and desorb lithium ions; (2) a method of placing a lithium foil on an electrode formed by a carbon material that can reversibly absorb and desorb lithium ions and a binder so that the lithium foil is in electrical contact with the electrode, and in this state, immersing the electrode in an electrolyte solution in which a lithium salt is dissolved to ionize the lithium and absorb the lithium ions into the carbon material; (3) a method of placing an electrode formed by a carbon material that can reversibly absorb and desorb lithium ions and a binder on the negative electrode side, placing lithium metal on the positive electrode side, immersing the electrodes in a non-aqueous electrolyte solution containing a lithium salt as an electrolyte, and passing a current to electrochemically absorb lithium in an ionized state into the carbon material.

[0918] As electric double layer capacitors, generally known are wound electric double layer capacitors, laminated electric double layer capacitors, coin-type electric double layer capacitors, etc., and the electric double layer capacitor may be in these forms.

[0919] For example, a wound electric double-layer capacitor is assembled by winding a positive electrode and a negative electrode consisting of a stack (electrode) of a current collector and an electrode layer through an insulator to form a wound element, placing the wound element in a casing made of aluminum or the like, filling it with an electrolyte, preferably a non-aqueous electrolyte, and then sealing it with a rubber sealing body.

[0920] As the separator, a conventionally known material and structure can be used, for example, a polyethylene porous film, polytetrafluoroethylene, a nonwoven fabric of polypropylene fiber, glass fiber, or cellulose fiber, etc. can be cited.

[0921] In addition, by known methods, a laminated double-layer capacitor can be made by stacking sheet-shaped positive and negative electrodes with an electrolyte and an isolator in between; or a coin-type double-layer capacitor can be made by fixing the positive and negative electrodes with a sealing gasket and with an electrolyte and an isolator in between so that the positive and negative electrodes are formed into a coin shape.

[0922] Example

[0923] Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

[0924] <Preparation of treatment solution>

[0925] The surface treatment agent A: 1,1′-difluoro-2,2′-bipyridylbis(tetrafluoroborate) or the surface treatment agent B: IF 5 A mixture of a pyridine-HF complex and acetonitrile as a solvent was used as the treatment liquid. The mixing ratio was 3 mg of the surface treatment agent per 1 ml (786 mg) of acetonitrile.

[0926] In addition, in the table|surface mentioned later, the process liquid containing the process agent A is described as the process agent A solution, and the process liquid containing the process agent B is described as the process agent B solution.

[0927] <Production of positive electrode>

[0928] LiNi as the positive electrode active material 0.5 Mn 1.5 O 485 mass % of (LNMO), 10 mass % of SuperC45 (carbon black) as a conductive aid, and 5 mass % of carboxymethyl cellulose (CMC) as a binder were mixed in distilled water to form a slurry. The obtained slurry was applied to one side of an aluminum foil with a thickness of 20 μm pre-coated with a conductive aid, dried, and rolled with a press. The obtained material was cut into a circular shape with an active material layer having a diameter of 12 mm as a positive electrode.

[0929] <Production of negative electrode>

[0930] In 97.3 parts by mass of carbonaceous material (graphite) as negative electrode active material, 1.2 parts by mass of aqueous dispersion of sodium carboxymethylcellulose (concentration of sodium carboxymethylcellulose 1% by mass) and 1.5 parts by mass of aqueous dispersion of styrene-butadiene rubber (concentration of styrene-butadiene rubber 50% by mass) as thickener and binder were added, and mixed with a disperser to form slurry. The obtained slurry was coated on a copper foil with a thickness of 10 μm and dried, rolled with a press, and the obtained material was cut into a circle with a diameter of 12 mm for the active material layer as a negative electrode.

[0931] <Preparation of electrolyte>

[0932] LiN (CF) was added to a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio 50:50) at a concentration of 1.0 mol / L. 3 SO 2 ) 2 (LiTFSI), as the electrolyte.

[0933] <Manufacturing of coin-type lithium-ion secondary batteries>

[0934] The positive electrode and the negative electrode were placed opposite to each other via a 20 μm thick microporous polyethylene film (separator), and an electrolyte was injected. After the electrolyte fully permeated the separator, etc., the battery was sealed, pre-charged, and aged to produce a lithium-ion secondary battery.

[0935] <EDX measurement>

[0936] The ratio (atomic %) of fluorine and the like was measured by energy dispersive X-ray spectroscopy (SEM-EDX) using a scanning electron microscope.

[0937] <Cyclic characteristics test>

[0938] After the coin-type lithium-ion secondary battery is charged with a constant current-constant voltage (hereinafter referred to as CC / CV charging) (0.1C cutoff) to 4.95V at a current equivalent to 1C at 20°C, it is discharged to 3.5V at a constant current of 1C. This is regarded as one cycle, and the initial discharge capacity is calculated from the discharge capacity of the third cycle. Here, 1C represents the current value for discharging the battery's reference capacity for 1 hour, for example, 0.2C represents 1 / 5 of its current value. The cycle is repeated again, and the discharge capacity after 1000 cycles is measured. The ratio of the discharge capacity after 1000 cycles to the initial discharge capacity is calculated and used as the cycle retention rate (%).

[0939] (Discharge capacity after 1000 cycles) ÷ (initial discharge capacity) × 100 = cycle retention rate (%)

[0940] <Experimental example of positive electrode active material>

[0941] (Examples A1 to A4)

[0942] After LNMO was immersed in the treatment solution at 25°C under the conditions of Table 1, it was taken out from the treatment solution and vacuum dried. Then, the ratio of fluorine on the surface of LNMO was measured by EDX measurement (atomic %), and the amount of unreacted and reacted surface treatment agent remaining on the surface of LNMO was calculated based on the mass difference of the active material before and after the treatment (mass %).

[0943] In addition, except that the treated LNMO was used as the positive electrode active material, a positive electrode was prepared by the above method, combined with a lithium metal foil to prepare a coin-type lithium ion secondary battery, and a cycle characteristic test was performed. The amount (mass %) of the surface treatment agent in the positive electrode mixture was calculated from the input amount of each material.

[0944] (Comparative Example A1)

[0945] The preparation and evaluation were carried out in the same manner as in Examples A1 to A4 except that LNMO was treated with fluorine gas. The treatment with fluorine gas was carried out in the same manner as in "(3) Fluorination of positive electrode active material" in Example 3 of Patent Document 1.

[0946] (Comparative Example A2)

[0947] Except that the positive electrode active material was not treated, the same procedures as in Examples A1 to A4 were carried out to prepare and evaluate.

[0948] [Table 1]

[0949]

[0950] <Experimental example of current collector foil>

[0951] (Examples B1 to B2)

[0952] The aluminum foil was immersed in a treatment liquid at 25° C. under the conditions of Table 2, then taken out of the treatment liquid and vacuum dried. Then, the ratio (atomic %) of fluorine and aluminum on the surface of the aluminum foil was measured by EDX measurement.

[0953] In addition, the treated aluminum foil was used for CV measurement. In the CV measurement, the aluminum foil was used as the working electrode, and metal lithium was used as the reference electrode and the counter electrode to prepare a three-electrode battery containing an electrolyte, and the measurement was performed 10 times at 20°C with a scan rate of 0.1 mV / sec and a scan range of 3.5V to 5V.

[0954] The aluminum foil after the CV measurement was subjected to EDX measurement to measure the ratio (atomic %) of fluorine and aluminum on the surface of the aluminum foil.

[0955] (Comparative Example B1)

[0956] The same procedures as in Examples B1 to B2 were followed to produce and evaluate the aluminum foil except that the aluminum foil was treated with fluorine gas. The fluorine gas treatment was carried out in the same manner as in "(1) Production of fluorinated aluminum foil" in Example 1 of Patent Document 1.

[0957] (Comparative Example B2)

[0958] Except that the aluminum foil was not treated, the same procedures as in Examples B1 to B2 were carried out and the evaluation was performed.

[0959] [Table 2]

[0960]

[0961] <Positive electrode experimental example>

[0962] (Examples C1 to C6)

[0963] The positive electrode was immersed in the treatment solution under the conditions of Table 3, then taken out from the treatment solution and vacuum dried. Then, the ratio (atomic %) of fluorine on the surface of the positive electrode was measured by EDX measurement.

[0964] Furthermore, a coin-type lithium ion secondary battery was produced by combining with lithium metal foil, and a cycle characteristic test was conducted.

[0965] (Comparative Example C1)

[0966] The positive electrodes were prepared and evaluated in the same manner as in Examples C1 to C6 except that the positive electrodes were treated with fluorine gas. The fluorine gas treatment was carried out in the same manner as in "(1) Preparation of fluorinated aluminum foil" in Example 1 of Patent Document 1.

[0967] (Comparative Example C2)

[0968] Except that the positive electrode was not treated, the same procedures as in Examples C1 to C6 were carried out to produce and evaluate.

[0969] [Table 3]

[0970] Treatment Fluorine ratio Cycle retention rate Example C1 Treatment agent A solution 10 minutes 3.47％ 55％ Example C2 Treatment agent A solution 30 minutes 3.86％ 60％ Example C3 Treatment agent A solution 60 minutes 4.20％ 68％ Example C4 Treatment agent B solution 10 minutes 3.45％ 52％ Example C5 Treatment agent B solution 30 minutes 3.82％ 58％ Example C6 Treatment agent B solution 60 minutes 4.18％ 66％ Comparative Example C1 Fluorine 4.12％ 50％ Comparative Example C2 -(Unprocessed) 0％ 49％

[0971] <Experimental example of negative electrode active material>

[0972] (Examples D1 to D4)

[0973] After the graphite was immersed in the treatment solution at 25°C under the conditions of Table 4, it was taken out from the treatment solution and vacuum dried. Then, the proportion of fluorine on the graphite surface (atomic %) was measured by EDX measurement, and the amount of unreacted and reacted surface treatment agent remaining on the graphite surface (mass %) was calculated based on the mass difference between the graphite before treatment and the graphite after treatment.

[0974] In addition, except that the treated graphite was used as the negative electrode active material, the negative electrode was prepared by the above method, combined with the positive electrode to prepare a coin-type lithium ion secondary battery, and the cycle characteristics test was carried out. The amount (mass %) of the surface treatment agent in the negative electrode mixture was calculated from the input amount of each material.

[0975] (Comparative Example D1)

[0976] The same method as in Examples D1 to D4 was used to prepare and evaluate the graphite except that the graphite was treated with fluorine gas. The fluorine gas treatment was carried out in the same manner as in "(3) Fluorination of positive electrode active material" in Example 3 of Patent Document 1 except that the graphite was used as the treatment object.

[0977] (Comparative Example D2)

[0978] Except that the graphite was not treated, the same procedures as in Examples D1 to D4 were carried out and the evaluation was performed.

[0979] [Table 4]

[0980]

[0981] < Experimental example of conductive additive >

[0982] (Examples E1 to E4)

[0983] After immersing the multilayer carbon nanotubes (CNT) in a treatment solution at 25°C under the conditions of Table 5, the multilayer carbon nanotubes were taken out from the treatment solution and vacuum dried. Then, the ratio of fluorine on the surface of the multilayer carbon nanotubes (atomic %) was measured by EDX measurement, and the amount of unreacted and reacted surface treatment agents remaining on the surface of the multilayer carbon nanotubes (mass %) was calculated based on the mass difference between the multilayer carbon nanotubes before and after the treatment.

[0984] In addition, a positive electrode was prepared by the above method except that the treated multi-walled carbon nanotubes were used as a conductive auxiliary agent, and a coin-type lithium ion secondary battery was prepared by combining it with a negative electrode and a cycle characteristic test was performed. The amount (mass %) of the surface treatment agent in the positive electrode mixture was calculated from the input amount of each material.

[0985] (Comparative Example E1)

[0986] The preparation and evaluation were carried out in the same manner as in Examples E1 to E4 except that the multiwalled carbon nanotubes were treated with fluorine gas. The fluorine gas treatment was carried out in the same manner as in "(3) Fluorination of positive electrode active material" in Example 3 of Patent Document 1 except that the multiwalled carbon nanotubes were used as the treatment objects.

[0987] (Comparative Example E2)

[0988] Except that the multiwalled carbon nanotubes were not treated, the same procedures as in Examples E1 to E4 were carried out for production and evaluation.

[0989] [Table 5]

[0990]

Claims

1. A surface treatment agent for an electrode material, characterized in that: It has a pyridine skeleton and fluorine.

2. The surface treatment agent for electrode material according to claim 1, wherein The surface treatment agent for the electrode material is an N-fluoropyridinium compound or a fluorinated halogen·pyridine·HF complex.

3. The surface treatment agent for electrode material according to claim 2, wherein The N-fluoropyridinium compound is 1,1′-difluoro-2,2′-bipyridylbis(tetrafluoroborate), and the fluorinated halogen·pyridine·HF complex is an IF5·pyridine·HF complex.

4. The surface treatment agent for an electrode material according to any one of claims 1 to 3, wherein The surface treatment agent for electrode material is used for positive electrode active material, current collecting foil, negative electrode active material, conductive auxiliary agent or electrode. 5 . A positive electrode active material treated with the surface treatment agent for an electrode material according to claim 1 . 6 . A current collecting foil treated with the surface treating agent for an electrode material according to claim 1 . 7 . A negative electrode active material treated with the electrode material surface treatment agent according to claim 1 . 8 . A conductive auxiliary agent treated with the surface treating agent for an electrode material according to claim 1 .

9. An electrode, characterized in that: The positive electrode active material according to claim 5 , the current collecting foil according to claim 6 , and the conductive auxiliary agent according to claim 8 are contained.

10. An electrode, characterized in that: The negative electrode active material according to claim 7 , the current collecting foil according to claim 6 , and the conductive auxiliary agent according to claim 8 are included.

11. A battery, characterized in that: Comprising the electrode according to claim 9 or 10.

12. The method for producing a positive electrode active material according to claim 5, characterized in that: A solution containing the electrode material surface treatment agent according to any one of claims 1 to 4 is brought into contact with a positive electrode active material.

13. The method for manufacturing the current collector foil according to claim 6, characterized in that: A solution containing the electrode material surface treatment agent according to any one of claims 1 to 4 is brought into contact with a current collecting foil.

14. The method for producing a negative electrode active material according to claim 7, characterized in that: A solution containing the electrode material surface treatment agent according to any one of claims 1 to 4 is brought into contact with a negative electrode active material.

15. The method for producing a conductive auxiliary agent according to claim 8, characterized in that: A solution containing the electrode material surface treatment agent according to any one of claims 1 to 4 is brought into contact with a conductive auxiliary agent.

16. A method for manufacturing an electrode, characterized in that: A solution containing the electrode material surface treatment agent according to any one of claims 1 to 4 is brought into contact with an electrode comprising a current collecting foil and a positive electrode active material or a negative electrode active material.

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