JP6024387B2 - Non-aqueous electrolyte and non-aqueous electrolyte battery using the same - Google Patents

Description

  The present invention relates to a non-aqueous electrolyte and a non-aqueous electrolyte battery using the same.

  Non-aqueous electrolyte batteries such as lithium secondary batteries are being put to practical use in a wide range of applications from so-called consumer power sources such as mobile phones and laptop computers to in-vehicle power sources for automobiles and the like. However, the demand for higher performance of non-aqueous electrolyte batteries in recent years has been increasing, and in particular, various battery characteristics such as high capacity, low temperature use characteristics, high temperature storage characteristics, cycle characteristics, and overcharge safety. Improvement is demanded.

  The electrolyte used for a non-aqueous electrolyte battery is usually composed mainly of an electrolyte and a non-aqueous solvent. The main components of the non-aqueous solvent include cyclic carbonates such as ethylene carbonate and propylene carbonate; chain carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate; cyclic carboxylic acid esters such as γ-butyrolactone and γ-valerolactone. It is used.

  In addition, in order to improve battery characteristics such as load characteristics, cycle characteristics, storage characteristics, etc. of such nonaqueous electrolyte batteries, and to enhance battery safety during overcharge, various nonaqueous solvents, electrolytes, and additives are used. Consideration has been made. Patent Document 1 proposes to protect the battery by increasing the internal resistance of the battery by mixing an additive that is polymerized at a battery voltage equal to or higher than the maximum operating voltage of the battery in the electrolyte. In 2 the internal electrical disconnection device provided for overcharge protection is ensured by mixing an additive that generates gas and pressure by polymerizing in the electrolyte at a battery voltage higher than the maximum operating voltage of the battery. It has been proposed to work. Moreover, aromatic compounds, such as biphenyl, thiophene, and furan, are disclosed as those additives.

Patent Documents 3 to 8 propose a method of adding various aromatics such as cyclohexylbenzene to the electrolytic solution, which has solved the problems of safety improvement and durability during overcharge to some extent.
Patent Document 9 proposes a method of adding 2,2-diphenylpropane or the like to the electrolyte in order to achieve both the cycle characteristics of the nonaqueous electrolyte secondary battery and the safety during overcharge. Yes.

Patent Document 10 proposes a method of incorporating bisphenol A diacetate or the like in a non-aqueous electrolyte in order to achieve both the cycle characteristics, high-temperature storage characteristics and overcharge safety of a non-aqueous electrolyte secondary battery. Has been.
In the non-aqueous electrolyte secondary battery using the electrolytic solution described in Patent Documents 1 to 9, although the overcharge characteristics are improved as described above, the initial capacity and the high-temperature storage characteristics are reduced and still not satisfactory. It wasn't good. Further, the non-aqueous electrolyte secondary battery using the electrolyte described in Patent Document 10 is not satisfactory in terms of improving safety during overcharging.

Japanese Unexamined Patent Publication No. 9-106835 Japanese Unexamined Patent Publication No. 9-171840 Japanese Unexamined Patent Publication No. 2001-15155 Japanese Unexamined Patent Publication No. 2002-56892 Japanese Unexamined Patent Publication No. 2003-109660 Japanese Unexamined Patent Publication No. 7-302614 Japanese Unexamined Patent Publication No. 2000-58117 Japanese Unexamined Patent Publication No. 2000-58116 Japanese Laid-Open Patent Publication No. 11-162512 Japanese Unexamined Patent Publication No. 2005-142157

  In view of the above problems, an object of the present invention is to provide a non-aqueous electrolyte battery that is excellent in safety during overcharge and high-temperature storage characteristics, and a non-aqueous electrolyte that provides the same.

As a result of various studies to achieve the above object, the present inventors have found that the above problems can be solved by including a compound having a specific structure in the electrolytic solution, thereby completing the present invention. It came to. That is, the gist of the present invention is as follows. (
1) A nonaqueous electrolytic solution containing an electrolyte and a nonaqueous solvent, wherein the nonaqueous electrolytic solution contains an aromatic compound represented by the general formula (I).

(In general formula (I),
R ¹ represents hydrogen, halogen, an optionally substituted hydrocarbon group, or an alkoxy group, and R ² represents hydrogen, halogen, an optionally substituted hydrocarbon group, an alkoxy group, an alkoxylcarbonyloxy group, or an organic sulfonate. Group, or phosphate ester group,
A represents a divalent substituent which may contain a hetero atom,
m represents an integer of 1 to 5,
n represents an integer of 0 to 5,
Furthermore, the aromatic ring in the compound may be substituted with halogen, an optionally substituted hydrocarbon group, or an alkoxy group. )
(2) The nonaqueous electrolyte solution according to (1), wherein the proportion of the compound represented by the general formula (I) in the nonaqueous electrolyte solution is 0.001 to 10% by mass.
(3) In a non-aqueous electrolyte solution containing an electrolyte and a non-aqueous solvent, a compound in which the non-aqueous electrolyte solution is dissolved by more than 0.5% by mass in the non-aqueous electrolyte solution represented by the general formula (I) and having a general composition The nonaqueous electrolytic solution according to (1), which is contained.
(4) It further contains at least one compound selected from the group consisting of a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate and a difluorophosphate. The nonaqueous electrolytic solution according to any one of (1) to (3) above,
(5) A non-aqueous electrolyte battery including a negative electrode and a positive electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is any one of the above (1) to (4) A non-aqueous electrolyte battery characterized by being the non-aqueous electrolyte solution described.

  According to the present invention, it is possible to provide a non-aqueous electrolyte battery having a high capacity and particularly excellent high-temperature storage characteristics while enhancing safety during overcharging, and reducing the size and performance of the non-aqueous electrolyte battery. Can be achieved.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist of the present invention.
<Non-aqueous electrolyte>
The nonaqueous electrolytic solution of the present invention contains an electrolyte and a nonaqueous solvent, and further contains an ester compound represented by the general formula (I).

(In general formula (I),
R ¹ represents hydrogen, halogen, an optionally substituted hydrocarbon group, or an alkoxy group, and R ² represents hydrogen, halogen, an optionally substituted hydrocarbon group, an alkoxy group, an alkoxylcarbonyloxy group, or an organic sulfonate. Group, or phosphate ester group,
A represents a divalent substituent which may contain a hetero atom,
m represents an integer of 1 to 5,
n represents an integer of 0 to 5,
Furthermore, the aromatic ring in the compound may be substituted with a halogen, an optionally substituted hydrocarbon group, an alkoxy group, or an aryl group. )

  As shown in the general formula (I), B is any one of an organic carbonyl group, an organic sulfonyl group, and a dialkoxyphosphoryl group, and is preferable from the viewpoint of improving safety during overcharge and improving high-temperature storage characteristics. Is an organic carbonyl group, an organic sulfonyl group, more preferably an organic carbonyl group.

In general formula (I), R ¹ represents hydrogen, halogen, an optionally substituted hydrocarbon group, or an alkoxy group, and is preferably substituted from the viewpoint of improving safety during overcharge and improving high-temperature storage characteristics. A hydrocarbon group and an alkoxy group which may be used, more preferably an alkoxy group. Examples of the halogen include fluorine, chlorine, bromine and iodine, and fluorine is preferred. Examples of the optionally substituted hydrocarbon group include an alkyl group, an alkenyl group, an aryl group, and an aralkyl group.

  Examples of the alkyl group include a chain alkyl group and a cyclic alkyl group. Specifically, a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec- Butyl group, t-butyl group, n-pentyl group, t-amyl group, n-hexyl group, 1,1-dimethylbutyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl Groups and the like. The carbon number of the alkyl group is usually 1 or more, and usually 12 or less, preferably 6 or less, more preferably 4 or less, and still more preferably 2 or less.

Examples of the alkenyl group include a vinyl group and a propenyl group. The carbon number is usually 2 or more, and usually 12 or less, preferably 8 or less, more preferably 4 or less.
Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a cyclohexylphenyl group, and a t-butylphenyl group, and among them, a phenyl group, a cyclohexylphenyl group, and a t-butylphenyl group are preferable. The carbon number of the aryl group is usually 6 or more and 12 or less.

Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, and a phenylpentyl group. Among them, a phenethyl group, a phenylpropyl group, and a phenylbutyl group are preferable from the viewpoint of improving overcharge characteristics. Most preferred is a phenylpropyl group. The carbon number of the aralkyl group is usually 7 or more and 12 or less.
Examples of the alkoxy group include a chain alkoxy group and a cyclic alkoxy group, and among them, a methyl alkoxy group, an ethyl alkoxy group, and a phenyl alkoxy group are preferable. Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, sec-butoxy group, t-butoxy group, n-pentoxy group, t-pentoxy group Group, n-hexyloxy group, 1,1-dimethylbutoxy group, cyclobutoxy group, cyclopentoxy group, cyclohexyloxy group, 1-methylcyclohexyloxy group, 1-ethylcyclohexyloxy group, phenoxy group, tolyloxy group, xylyloxy Group, cyclohexylphenoxy group, t-butylphenoxy group and the like. The carbon number of the alkoxy group is usually 1 or more, and usually 12 or less, preferably 6 or less, more preferably 4 or less, and still more preferably 2 or less.

  The alkyl group, alkenyl group, aryl group, aralkyl group and alkoxy group may be substituted with fluorine. Examples of the fluorine-substituted group include a trifluoromethyl group, a trifluoroethyl group and a pentafluoroethyl group. Fluorinated alkyl groups such as 2-fluorovinyl groups, 3-fluoro-2-propenyl groups, etc., fluorinated alkenyl groups, 2-fluorophenyl groups, 3-fluorophenyl groups, 4-fluorophenyl groups, etc. Groups, fluorinated aralkyl groups such as a fluorophenylpropyl group, fluorinated alkoxy groups such as a trifluoromethoxy group, a trifluoroethoxy group, and a pentafluoroethoxy group.

In general formula (I), R ² represents hydrogen, halogen, an optionally substituted hydrocarbon group, an alkoxy group, an alkoxylcarbonyloxy group, an organic sulfonate group, or a phosphate ester group, and safety during overcharge From the viewpoint of improving the high-temperature storage characteristics and the high-temperature storage characteristics, preferably an optionally substituted hydrocarbon group, alkoxy group, alkoxylcarbonyloxy group, organic sulfonate group, more preferably alkoxylcarbonyloxy group, organic sulfonate group, more preferably An alkoxylcarbonyloxy group; Examples of the halogen include fluorine, chlorine, bromine and iodine, and fluorine is preferred. Examples of the optionally substituted hydrocarbon group include an alkyl group, an alkenyl group, an aryl group, and an aralkyl group.

  Examples of the alkyl group include a chain alkyl group and a cyclic alkyl group. Specifically, a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec- Butyl group, t-butyl group, n-pentyl group, t-amyl group, n-hexyl group, 1,1-dimethylbutyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl Groups and the like. The carbon number of the alkyl group is usually 1 or more, and usually 12 or less, preferably 6 or less, more preferably 4 or less, and still more preferably 2 or less.

Examples of the alkenyl group include a vinyl group and a propenyl group. The carbon number is usually 2 or more, and usually 12 or less, preferably 8 or less, more preferably 4 or less.
Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a cyclohexylphenyl group, and a t-butylphenyl group, and among them, a phenyl group, a cyclohexylphenyl group, and a t-butylphenyl group are preferable. The carbon number of the aryl group is usually 6 or more and 12 or less.

Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, and a phenylpentyl group. Among them, a phenethyl group, a phenylpropyl group, and a phenylbutyl group are preferable from the viewpoint of improving overcharge characteristics. Most preferred is a phenylpropyl group. The carbon number of the aralkyl group is usually 7 or more and 12 or less.
Examples of the alkoxy group include a chain alkoxy group and a cyclic alkoxy group. Specifically, a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, sec- Butoxy group, t-butoxy group, n-pentoxy group, t-pentoxy group, n-hexyloxy group, 1,1-dimethylbutoxy group, cyclobutoxy group, cyclopentoxy group, cyclohexyloxy group, 1-methylcyclohexyl Examples thereof include an oxy group, 1-ethylcyclohexyloxy group, phenoxy group, tolyloxy group, xylyloxy group, cyclohexylphenynoxy group, t-butylphenoxy group and the like. The carbon number of the alkoxy group is usually 1 or more, and usually 12 or less, preferably 6 or less, more preferably 4 or less, and still more preferably 2 or less.

  The alkoxycarbonyloxy group is preferably a methylalkoxycarbonyloxy group, an ethylalkoxycarbonyloxy group, or a phenylalkoxycarbonyloxy group. Specifically, methyl carbonate group, ethyl carbonate group, n-propyl carbonate group, i-propyl carbonate group, n-butyl carbonate group, i-butyl carbonate group, sec-butyl carbonate group, t-butyl carbonate group, n -Pentyl carbonate group, t-pentyl carbonate group, n-hexyl carbonate group, 1,1-dimethylbutyl carbonate group, cyclobutyl carbonate group, cyclopentyl carbonate group, cyclohexyl carbonate group, 1-methylcyclohexyl carbonate group, 1-ethylcyclohexyl Examples thereof include a carbonate group, a phenyl carbonate group, a tolyl carbonate group, a xylyl carbonate group, a cyclohexyl phenyl carbonate group, and a t-butylphenyl carbonate group. The carbon number of the alkoxycarbonyloxy group is usually 1 or more, and usually 12 or less, preferably 10 or less, more preferably 6 or less, still more preferably 4 or less, and most preferably 2 or less.

Specific examples of the alkyl sulfonate group include methyl sulfonate group, ethyl sulfonate group, n-propyl sulfonate group, i-propyl sulfonate group, n-butyl sulfonate group, i-butyl sulfonate group, sec-butyl sulfonate group, t -Butyl sulfonate group, n-pentyl sulfonate group, t-pentyl sulfonate group, n-hexyl sulfonate group, 1,1-dimethylbutyl sulfonate group, cyclobutyl sulfonate group, cyclopentyl sulfonate group, cyclohexyl sulfonate group, 1-methylcyclohexyl sulfonate Group, 1-ethylcyclohexyl sulfonate group, phenyl sulfonate group, tolyl sulfonate group, xylyl sulfonate group, cyclohexyl phenyl sulfonate group, t-butylphenyl Sulfonate group, and the like. The carbon number of the alkyl sulfonate group is usually 1 or less, and usually 10 or less, preferably 6 or less, more preferably 4 or less, and still more preferably.

  Specific examples of the phosphate ester group include a dimethyl phosphate ester group, a diethyl phosphate ester group, a di n-propyl phosphate ester group, a di i-propyl phosphate ester group, a di n-butyl phosphate ester group, Di-butyl phosphate group, disec-butyl phosphate group, di-t-butyl phosphate group, di-n-pentyl phosphate group, di-t-pentyl phosphate group, di-n-hexyl phosphate group, di-1 , 1-dimethylbutyl phosphate group, dicyclobutyl phosphate group, dicyclopentyl phosphate group, dicyclohexyl phosphate group, di1-methylcyclohexyl phosphate group, di1-ethylcyclohexyl phosphate group , Diphenyl phosphate group, ditolyl phosphate group, dixylyl Phosphoric acid ester group, dicyclohexyl phenyl phosphate ester group, di-t- butylphenyl phosphate ester group and the like. The carbon number of the phosphate ester group is usually 1 or more, and usually 10 or less, preferably 6 or less, more preferably 4 or less, and still more preferably 2 or less.

In addition, the alkyl group, alkenyl group, aryl group, aralkyl group, alkoxy group and alkoxycarbonyloxy group, sulfonate group, and phosphate ester group may be fluorine-substituted. Examples of the fluorine-substituted group include trifluoro Fluorinated alkyl groups such as methyl group, trifluoroethyl group, pentafluoroethyl group, fluorinated alkenyl groups such as 2-fluorovinyl group, 3-fluoro-2-propenyl group, 2-fluorophenyl group, 3-fluorophenyl Group, fluorinated aryl group such as 4-fluorophenyl group, fluorinated aralkyl group such as fluorophenylpropyl group, fluorinated alkoxy group such as trifluoromethoxy group, trifluoroethoxy group, pentafluoroethoxy group, trifluoromethyl carbonate Group, pentafluoroethylcarbo Fluorinated alkoxycarbonyloxy groups such as carbonate groups, fluorophenyl carbonate groups, trifluoromethyl sulfonate groups, pentafluoroethyl sulfonate groups, fluorinated sulfonate groups such as fluorophenyl sulfonate groups, ditrifluoromethyl phosphate ester groups, dipenta Fluorophosphate groups such as a fluoroethyl phosphate ester group and a difluorophenyl phosphate group can be mentioned.
In the general formula (I), examples of the divalent substituent that may contain a hetero atom represented by A include oxygen, sulfur, a carbonyl group, a sulfonyl group, an optionally substituted alkylidene group, Examples thereof include a cycloalkylidene group, an arylene group, an arylidene group, an aralkylidene group, and the like.

  Examples of the alkylidene group and cycloalkylidene group include a methylene group, an ethylidene group, a methylmethylene group, a propylidene group, a dimethylmethylene group, a butylidene group, a methyl-ethyl-methylene group, a pentylidene group, a dimethylmethyl-methyl-methylene group, a hexylidene group, and a dimethyl group. Ethyl-methyl-methylene group, heptylidene group, octylidene group, nonanilidene group, decanylidene group, cyclopentylidene group, cyclohexylidene group, 3-methylcyclohexylidene group, 3-isopropylcyclohexylidene group, 3-dimethyl-5 -Methyl-cyclohexylidene group, bisdimethylindane group and the like. The alkylidene group may be substituted with a halogen such as fluorine, and examples thereof include a difluoromethylene group and a di-trifluoromethyl-methylene group.

As an arylene group, an arylidene group, and an aralkylidene group, a phenylene group, a phenylidene group, a phenylmethylene group, a methylphenylmethylene group, a diphenylmethylene group, a biphenylylmethylene group, a 1,4-phenylenebis (1 methylethylidene) group, 1, A 3-phenylenebis (1-methylethylidene) group, a fluorophenylmethylene group, a fluorene-ylidene group, a methoxyphenylmethylene group, and the like can be given.

From the viewpoint of solubility in the electrolytic solution, the carbon number of the optionally substituted alkylidene group, cycloalkylidene group, arylene group, arylidene group, and aralkylidene group is usually 1 or more, and usually 13 or less, preferably 8 Below, more preferably 4 or less.
Among these, A is preferably oxygen, a carbonyl group, a sulfonyl group, a methylene group, an ethylidene group, a cyclohexylidene group, 3-dimethyl-5-, from the viewpoint of improving safety during overcharge and improving high-temperature storage characteristics. Methyl-cyclohexylidene group, dimethylmethylene group, phenylene group, more preferably oxygen, carbonyl group, sulfonyl group, cyclohexylidene group, 3-dimethyl-5-methyl-cyclohexylidene group, dimethylmethylene group, phenylene group, More preferably oxygen, sulfonyl group, cyclohexylidene group, 3-dimethyl-5-methyl-cyclohexylidene group, dimethylmethylene group, phenylene group, most preferably sulfonyl group, cyclohexylidene group, 3-dimethyl-5- Methyl-cyclohexylidene group, dimethylmethylene group, phenylene group A.

In general formula (I), m represents an integer of 1 or more and 5 or less, and preferably 3 or less, more preferably 2 or less, and most preferably 1 from the viewpoint of improving safety during overcharge and improving high-temperature storage characteristics. It is.
In general formula (I), n represents an integer of 0 or more and 5 or less, and is preferably 3 or less, more preferably 2 or less, and most preferably 1 from the viewpoint of improving safety during overcharge and improving high-temperature storage characteristics. It is.

Specific examples of the compound represented by the general formula (I) include
2,2-bis (p-methoxycarbonyloxyphenyl) propane, 1,1-bis (p-methoxycarbonyloxyphenyl) cyclohexane, bis (p-methoxycarbonyloxyphenyl) sulfone, 2,2-bis (p-methoxy) Carbonyloxyphenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (p-methoxycarbonyloxyphenyl) -3-phenylethane, 2,2-bis (p-methoxycarbonyloxy) Phenyl) butane, 2,2-bis (p-methoxycarbonyloxyphenyl) -1,3
Diphenylmethane, 2,2-bis (p-methoxycarbonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-methoxycarbonyloxy-m-i-propyl-phenyl) propane, 2,2-bis (P-methoxycarbonyloxyphenyl) propane, 1,4-bis (p-methoxycarbonyloxyphenyl- (1-methylethylidene) benzene, 1,3-bis (p-methoxycarbonyloxyphenyl- (1-methylethylidene) Benzene, 2,2-bis (p-methoxycarbonyloxy-m-phenyl-phenyl) propane, 1,1-bis (p-methoxycarbonyloxyphenyl) -3,3, -dimethyl-
5-methyl-cyclohexane, 2,2-bis (p-ethoxycarbonyloxyphenyl) propane, 1,1-bis (p-ethoxycarbonyloxyphenyl) cyclohexane, bis (p-ethoxycarbonyloxyphenyl) sulfone, 2,2 -Bis (p-ethoxycarbonyloxyphenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (p-ethoxycarbonyloxyphenyl) -3-phenylethane, 2,2-bis (P-ethoxycarbonyloxyphenyl) butane, 2,2-bis (p-ethoxycarbonyloxyphenyl) -1,3-diphenylmethane, 2,2-bis (p-ethoxycarbonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-ethoxycarbonyloxy-m-i-propyl-phen Le) propane, 2,2-bis (p- ethoxycarbonyloxy) propane, 1,4-bis (p- ethoxycarbonyloxy-phenyl - (
1-methylethylidene) benzene, 1,3-bis (p-ethoxycarbonyloxyphenyl- (1-methylethylidene) benzene, 2,2-bis (p-ethoxycarbonyloxy-)
m-phenyl-phenyl) propane, 1,1-bis (p-ethoxycarbonyloxyphenyl) -3,3, -dimethyl-5-methyl-cyclohexane, 2,2-bis (p-phenoxycarbonyloxyphenyl) propane, 1,1-bis (p-phenoxycarbonyloxyphenyl) cyclohexane, bis (p-phenoxycarbonyloxyphenyl) sulfone, 2,2-bis (p-phenoxycarbonyloxyphenyl) 1,1,1,3,3,3 Hexafluoropropane, 2,2-bis (p-phenoxycarbonyloxyphenyl) -3-phenylethane, 2,2-bis (p-phenoxycarbonyloxyphenyl) butane, 2,2-bis (p-phenoxycarbonyloxy) Phenyl) -1,3-diphenylmethane, 2,2-bis (p-phenyl) Roh alkoxycarbonyloxy -m- methyl - phenyl) propane, 2,2-bis (p- phenoxycarbonyloxy -m-i-propyl-phenyl) -
Propane, 2,2-bis (p-phenoxycarbonyloxyphenyl) propane, 1,4-bis (p-phenoxycarbonyloxyphenyl- (1-methylethylidene) benzene, 1,3-bis (p-phenoxycarbonyloxyphenyl) -(1-methylethylidene) benzene, 2,2-bis (p-phenoxycarbonyloxy-m-phenyl-phenyl) propane, 1,1-bis (p-phenoxycarbonyloxyphenyl) -3,3, -dimethyl- Compounds wherein B is an organic carbonyl group, such as 5-methyl-cyclohexane;

2,2-bis (p-methoxysulfonyloxyphenyl) propane, 1,1-bis (p-methoxysulfonyloxyphenyl) cyclohexane, bis (p-methoxysulfonyloxyphenyl) sulfone, 2,2-bis (p-methoxy) Sulfonyloxyphenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (p-methoxysulfonyloxyphenyl) -3-phenylethane, 2,2-bis (p-methoxysulfonyloxy) Phenyl) butane, 2,2-bis (p-methoxysulfonyloxyphenyl) -1,3
-Diphenylmethane, 2,2-bis (p-methoxysulfonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-methoxysulfonyloxy-m-i-propyl-phenyl) propane, 2,2-bis (P-methoxysulfonyloxyphenyl) propane, 1,4-bis (p-methoxysulfonyloxyphenyl- (1-methylethylidene) benzene, 1,3-bis (p-methoxysulfonyloxyphenyl- (1-methylethylidene) Benzene, 2,2-bis (p-methoxysulfonyloxy-m-phenyl-phenyl) propane, 1,1-bis (p-methoxysulfonyloxyphenyl) -3,3, -dimethyl-
5-methyl-cyclohexane, 2,2-bis (p-ethoxysulfonyloxyphenyl) propane, 1,1-bis (p-ethoxysulfonyloxyphenyl) cyclohexane, bis (p-ethoxysulfonyloxyphenyl) sulfone, 2,2 -Bis (p-ethoxysulfonyloxyphenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (p-ethoxysulfonyloxyphenyl) -3-phenylethane, 2,2-bis (P-ethoxysulfonyloxyphenyl) butane, 2,2-bis (p-ethoxysulfonyloxyphenyl) -1,3-diphenylmethane, 2,2-bis (p-ethoxysulfonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-ethoxysulfonyloxy-m-i-propyl-phen Le) propane, 2,2-bis (p- ethoxy sulfonyloxy phenyl) propane, 1,4-bis (p- ethoxy sulfonyloxy phenyl - (
1-methylethylidene) benzene, 1,3-bis (p-ethoxysulfonyloxyphenyl- (1-methylethylidene) benzene, 2,2-bis (p-ethoxysulfonyloxy-)
m-phenyl-phenyl) propane, 1,1-bis (p-ethoxysulfonyloxyphenyl) -3,3, -dimethyl-5-methyl-cyclohexane, 2,2-bis (p-phenoxysulfonyloxyphenyl) propane, 1,1-bis (p-phenoxysulfonyloxyphenyl) cyclohexane, bis (p-phenoxysulfonyloxyphenyl) sulfone, 2,2-bis (p-phenoxysulfonyloxyphenyl) 1,1,1,3,3,3 Hexafluoropropane, 2,2-bis (p-phenoxysulfonyloxyphenyl) -3-phenylethane, 2,2-bis (p-phenoxysulfonyloxyphenyl) butane, 2,2-bis (p-phenoxysulfonyloxy) Phenyl) -1,3-diphenylmethane, 2,2-bis (p-phenyl) Roh carboxymethyl sulfonyloxy -m- methyl - phenyl) propane, 2,2-bis (p- phenoxy sulfonyloxy -m-i-propyl-phenyl) -
Propane, 2,2-bis (p-phenoxysulfonyloxyphenyl) propane, 1,4-bis (p-phenoxysulfonyloxyphenyl)-(1-methylethylidene) benzene, 1,3-bis (p-phenoxysulfonyloxyphenyl) -(1-methylethylidene) benzene, 2,2-bis (p-phenoxysulfonyloxy-m-phenyl-phenyl) propane, 1,1-bis (p-phenoxysulfonyloxyphenyl) -3,3, -dimethyl- Compounds wherein B is an organic sulfonyl group, such as 5-methyl-cyclohexane;

2,2-bis (p-methoxydimethoxyphosphorylphenyl) propane, 1,1-bis (p-methoxydimethoxyphosphorylphenyl) cyclohexane, bis (p-methoxydimethoxyphosphorylphenyl) sulfone, 2,2-bis (p-methoxy) Dimethoxyphosphorylphenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (p-methoxydimethoxyphosphorylphenyl) -3-phenylethane, 2,2-bis (p-methoxydimethoxyphosphoryl) Phenyl) butane, 2,2-bis (p-methoxydimethoxyphosphorylphenyl) -1,3-diphenylmethane, 2,2-bis (p-methoxydimethoxyphosphoryl m-methyl-phenyl) propane, 2,2-bis (p -Methoxydimethoxyphosphoryl mi-propyl- Benzyl) propane, 2,2-bis (p-methoxydimethoxyphosphorylphenyl) propane, 1,4-bis (p-methoxydimethoxyphosphorylphenyl- (1-methylethylidene) benzene, 1,3-bis (p-methoxydimethoxy) Phosphorylphenyl- (1-methylethylidene) benzene, 2,2-bis (p-methoxydimethoxyphosphoryl m-phenyl-phenyl) propane, 1,1-bis (p-methoxydimethoxyphosphorylphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
2,2-bis (p-ethoxydimethoxyphosphorylphenyl) propane, 1,1-bis (p-ethoxydimethoxyphosphorylphenyl) cyclohexane, bis (p-ethoxydimethoxyphosphorylphenyl) sulfone, 2,2-bis (p-ethoxy) Dimethoxyphosphorylphenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (p-ethoxydimethoxyphosphorylphenyl) -3-phenylethane, 2,2-bis (p-ethoxydimethoxyphosphoryl) Phenyl) butane, 2,2-bis (p-ethoxydimethoxyphosphorylphenyl) -1,3-diphenylmethane, 2,2-bis (p-ethoxydimethoxyphosphoryl m-methyl-phenyl) propane, 2,2-bis (p -Ethoxydimethoxyphosphoryl mi-propyl- Enyl) propane, 2,2-bis (p-ethoxydimethoxyphosphorylphenyl) propane, 1,4-bis (p-ethoxydimethoxyphosphorylphenyl- (1-methylethylidene) benzene, 1,3-bis (p-ethoxydimethoxy) Phosphorylphenyl- (1-methylethylidene) benzene, 2,2-bis (p-ethoxydimethoxyphosphoryl m-phenyl-phenyl) propane, 1,1-bis (p-ethoxydimethoxyphosphorylphenyl) -3,3, -dimethyl -5-methyl-cyclohexane, 2
, 2-bis (p-phenoxydimethoxyphosphorylphenyl) propane, 1,1-bis (p-phenoxydimethoxyphosphorylphenyl) cyclohexane, bis (p-phenoxydimethoxyphosphorylphenyl) sulfone, 2,2-bis (p-phenoxydimethoxy) Phosphorylphenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (p-phenoxydimethoxyphosphorylphenyl) -3-phenylethane, 2,2-bis (p-phenoxydimethoxyphosphorylphenyl) ) Butane, 2,2-bis (p-phenoxydimethoxyphosphorylphenyl) -1,3-diphenylmethane, 2,2-bis (p-phenoxydimethoxyphosphoryl m-methyl-phenyl) propane, 2,2-bis (p- Phenoxydimethoxyphosphoryl m -I-propyl-phenyl) propane, 2,2-bis (p
-Phenoxydimethoxyphosphorylphenyl) propane, 1,4-bis (p-phenoxydimethoxyphosphorylphenyl- (1-methylethylidene) benzene, 1,3-bis (p-phenoxydimethoxyphosphorylphenyl)-(1-methylethylidene) benzene, 2, 2
-Bis (p-phenoxydimethoxyphosphoryl m-phenyl-phenyl) propane, 1,
1-bis (p-phenoxydimethoxyphosphorylphenyl) -3,3, -dimethyl-5
Examples include compounds in which B is a dialkoxyphosphoryl group, such as methyl-cyclohexane.

Among them, 2,2-bis (p-methoxycarbonyloxyphenyl) propane, 1,1-bis (p-methoxycarbonyloxyphenyl) cyclohexane, 2,2-bis (p-methoxycarbonyloxyphenyl) 1,1,1 , 3,3,3-hexafluoropropane, 2,2-bis (p-methoxycarbonyloxyphenyl) -3-phenylethane, 2,2-bis (p-methoxycarbonyloxyphenyl) butane, 2,2-bis (P-methoxycarbonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-methoxycarbonyloxy-mi-propyl-phenyl) propane, 2,2-bis (p-methoxycarbonyloxyphenyl) Propane, 1,1-bis (p-methoxycarbonyloxyphenyl) -3,3, -dimethyl-5 Methyl - cyclohexane,

2,2-bis (p-ethoxycarbonyloxyphenyl) propane, 1,1-bis (p-ethoxycarbonyloxyphenyl) cyclohexane, 2,2-bis (p-ethoxycarbonyloxyphenyl) 1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis (p-ethoxycarbonyloxyphenyl) -3-phenylethane, 2,2-bis (p-ethoxycarbonyloxyphenyl) butane, 2,2-bis (p -Ethoxycarbonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-ethoxycarbonyloxy-m-i-propyl-phenyl) propane, 2,2-bis (p-ethoxycarbonyloxyphenyl) propane, 1,1-bis (p-ethoxycarbonyloxyphenyl) -3,3, -dimethyl-5-methyl Cyclohexane,

2,2-bis (p-phenoxycarbonyloxyphenyl) propane, 1,1-bis (p-phenoxycarbonyloxyphenyl) cyclohexane, 2,2-bis (p-phenoxycarbonyloxyphenyl) 1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis (p-phenoxycarbonyloxyphenyl) -3-phenylethane, 2,2-bis (p-phenoxycarbonyloxyphenyl) butane, 2,2-bis (p -Phenoxycarbonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-phenoxycarbonyloxy-mi-propyl-phenyl) propane, 2,2-bis (p-phenoxycarbonyloxyphenyl) propane, 1,1-bis (p-phenoxycarbonyloxyphenyl) -3,3, -di Chill-5-methyl - cyclohexane,
A compound wherein B is an organic carbonyl group;

2,2-bis (p-methoxysulfonyloxyphenyl) propane, 1,1-bis (p-methoxysulfonyloxyphenyl) cyclohexane, 2,2-bis (p-methoxysulfonyloxyphenyl) 1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis (p-methoxysulfonyloxyphenyl) -3-phenylethane, 2,2-bis (p-methoxysulfonyloxyphenyl) butane, 2,2-bis (p -Methoxysulfonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-methoxysulfonyloxy-m-i-propyl-phenyl) propane, 2,2-bis (p-methoxysulfonyloxyphenyl) propane, 1,1-bis (p-methoxysulfonyloxyphenyl) -3,3, -dimethyl-5-methyl Cyclohexane,

2,2-bis (p-ethoxysulfonyloxyphenyl) propane, 1,1-bis (p-ethoxysulfonyloxyphenyl) cyclohexane, 2,2-bis (p-ethoxysulfonyloxyphenyl) 1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis (p-ethoxysulfonyloxyphenyl) -3-phenylethane, 2,2-bis (p-ethoxysulfonyloxyphenyl) butane, 2,2-bis (p -Ethoxysulfonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-ethoxysulfonyloxy-m-i-propyl-phenyl) propane, 2,2-bis (p-ethoxysulfonyloxyphenyl) propane, 1,1-bis (p-ethoxysulfonyloxyphenyl) -3,3, -dimethyl-5-methyl Cyclohexane,

2,2-bis (p-phenoxysulfonyloxyphenyl) propane, 1,1-bis (p-phenoxysulfonyloxyphenyl) cyclohexane, 2,2-bis (p-phenoxysulfonyloxyphenyl) 1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis (p-phenoxysulfonyloxyphenyl) -3-phenylethane, 2,2-bis (p-phenoxysulfonyloxyphenyl) butane, 2,2-bis (p -Phenoxysulfonyloxy-m-methyl-phenyl) propane, 2,2-bis (p-phenoxysulfonyloxy-mi-propyl-phenyl) propane, 2,2-bis (p-phenoxysulfonyloxyphenyl) propane, 1,1-bis (p-phenoxysulfonyloxyphenyl) -3,3, -di Chill-5-methyl - cyclohexane,
And the like, wherein B is an organic sulfonyl group,

2,2-bis (p-methoxycarbonyloxyphenyl) propane, 1,1-bis (p-methoxycarbonyloxyphenyl) cyclohexane, 1,1-bis (p-methoxycarbonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
2,2-bis (p-ethoxycarbonyloxyphenyl) propane, 1,1-bis (p-ethoxycarbonyloxyphenyl) cyclohexane, 1,1-bis (p-ethoxycarbonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
2,2-bis (p-phenoxycarbonyloxyphenyl) propane, 1,1-bis (p-phenoxycarbonyloxyphenyl) cyclohexane, 1,1-bis (p-phenoxycarbonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
A compound wherein B is an organic carbonyl group;

2,2-bis (p-methoxysulfonyloxyphenyl) propane, 1,1-bis (p-methoxysulfonyloxyphenyl) cyclohexane, 1,1-bis (p-methoxysulfonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
2,2-bis (p-ethoxysulfonyloxyphenyl) propane, 1,1-bis (p-ethoxysulfonyloxyphenyl) cyclohexane, 1,1-bis (p-ethoxysulfonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
2,2-bis (p-phenoxysulfonyloxyphenyl) propane, 1,1-bis (p-phenoxysulfonyloxyphenyl) cyclohexane, 1,1-bis (p-phenoxysulfonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
A compound in which B is an organic sulfonyl group is more preferable.

The compounds represented by formula (I) may be used alone or in combination of two or more. The proportion of the compound represented by formula (I) in the non-aqueous electrolyte is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably. It is 0.1% by mass or more, usually 10% by mass or less, preferably 8% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, and particularly preferably 2.5% by mass or less.
By being in the said range, the effect of this invention is easy to express and the fall of the capacity | capacitance of a battery is prevented.

The compound represented by the general formula (I) is arbitrary as long as the above conditions are satisfied. However, the solubility in the electrolytic solution is preferably higher from the viewpoint of improving the rate characteristics and low-temperature characteristics of the battery. For example, a test to confirm the presence or absence of phase separation by mixing a compound at room temperature with a general electrolyte composition mixture in which 1.0 M LiPF6 is dissolved in a solvent in which ethylene carbonate and ethylmethyl carbonate are mixed at a volume ratio of 3: 7. Is used, the solubility of the compound represented by the general formula (I) is usually more than 0.5% by mass, preferably 0.7% by mass or more, more preferably 1.0% by mass or more, most preferably 1. .5% by mass or more.

Specific examples of the compound represented by the general formula (I) satisfying the solubility include 2,2-bis (p-methoxycarbonyloxyphenyl) propane and 1,1-bis (p-methoxycarbonyloxyphenyl) cyclohexane. 1,1-bis (p-methoxycarbonyloxyphenyl) -3,3, -dimethyl-5-methyl-cyclohexane,
2,2-bis (p-ethoxycarbonyloxyphenyl) propane, 1,1-bis (p-ethoxycarbonyloxyphenyl) cyclohexane, 1,1-bis (p-ethoxycarbonyloxyphenyl) -3,3, -dimethyl A compound wherein B is an organic carbonyl group, such as -5-methyl-cyclohexane;

2,2-bis (p-methoxysulfonyloxyphenyl) propane, 1,1-bis (p-methoxysulfonyloxyphenyl) cyclohexane, 1,1-bis (p-methoxysulfonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
2,2-bis (p-ethoxysulfonyloxyphenyl) propane, 1,1-bis (p-ethoxysulfonyloxyphenyl) cyclohexane, 1,1-bis (p-ethoxysulfonyloxyphenyl) -3,3, -dimethyl -5-methyl-cyclohexane,
And compounds in which B is an organic sulfonyl group.

The reason why the non-aqueous electrolyte according to the present invention is excellent in safety during overcharge and excellent in high-temperature storage characteristics is not clear, and the present invention is not limited to the following operation principle, It is guessed as follows.
The compound represented by the general formula (I) has two benzene rings, a divalent group connecting the two benzene rings, and a substituent on the benzene ring. In general, a compound with two or more benzene rings linked is π-electron conjugated, has a low oxidation potential, and is highly reactive. Can increase the sex. However, compounds having conjugation usually have a low activation energy for the oxidation reaction and react at a site where the activity of the electrode is high even during high temperature storage, thereby degrading battery characteristics after high temperature storage. Moreover, since it is easy to reduce | restore on a battery negative electrode, there exists a tendency to degrade a negative electrode membrane | film | coat. By connecting two benzene rings through a divalent group, the storage characteristics are improved, but the reactivity during overcharge is also lowered, and sufficient safety is not ensured.

However, in the present invention, the activation energy of the oxidation reaction is increased by passing an appropriately sized divalent substituent between the two benzene rings, and the secondary electrode on the electrode is used during a battery durability test such as high-temperature storage. It is thought that the reactivity at the time of overcharge is raised by suppressing reaction and having a substituent in each benzene ring. In addition, by reducing the balance between the electron donating and attractive properties of the divalent substituent connecting the two benzene rings and the substituents on each benzene ring, the reduction on the negative electrode in the battery is suppressed and the storage characteristics are improved. I guess. Further, when m = 1 or more and n = 0 or more, there is an effect that the solubility in the electrolytic solution is increased.

  In particular, a compound having two benzene rings bonded via a divalent substituent and having a substituent on the benzene ring, as in the present invention, has a high stabilizing effect on the benzene ring and a high activity of the positive electrode. The reaction can be further suppressed, and at the same time, by appropriately setting the characteristics of the divalent substituent, two benzene rings that do not react during storage can react in a high energy state such as overcharge. Therefore, it is considered that the effect of suppressing deterioration of battery characteristics after high-temperature storage is high while enhancing safety during overcharge.

(Electrolytes)
There is no restriction | limiting in the electrolyte used for the non-aqueous electrolyte solution of this invention, A well-known thing can be used arbitrarily if it is used as an electrolyte for the target non-aqueous electrolyte secondary battery.
When the nonaqueous electrolytic solution of the present invention is used for a lithium secondary battery, a lithium salt is usually used as an electrolyte.

Specific examples of the electrolyte include LiClO ₄ , LiAsF ₆ , LiPF ₆ , and LiBF _4.
Inorganic lithium salts such as LiFSO ₃ ; LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , lithium cyclic 1,2-tetrafluoroethanedisulfonylimide, lithium cyclic 1 , 3-hexafluoropropanedisulfonylimide, LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiC (CF ₃ SO ₂ ) ₃ , 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 , LiBF ₂ (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
Fluorine-containing organic lithium salts such as lithium bis (oxalato) borate, lithium difluorooxalatoborate, lithium tris (oxalato) phosphate, lithium difluorobis (oxalato) phosphate, lithium tetrafluorooxalatophosphate and the like; Etc.

Among these, LiPF ₆ , LiBF ₄ , LiFSO ₃ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , lithium cyclic 1,2-tetrafluoroethanedisulfonylimide , Lithium cyclic 1,3-hexafluoropropane disulfonylimide, lithium bis (oxalato) borate, lithium difluorooxalatoborate, lithium tris (oxalato) phosphate, lithium difluorobis (oxalato) phosphate, lithium tetrafluorooxalatophosphate In particular, LiPF ₆ and LiBF ₄ are preferable.

Moreover, these lithium salts may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. In particular, the combined use of specific inorganic lithium salts and the combined use of inorganic lithium salts with fluorine-containing organic lithium salts and carboxylic acid complex lithium salts suppresses gas generation during high-temperature storage or suppresses deterioration after high-temperature storage. Therefore, it is preferable.
In particular, the combination and the LiPF ₆ and LiBF _4, and an inorganic lithium salt such as _{LiPF 6, LiBF 4, LiCF 3} SO 3, LiN (CF 3 SO 2) 2, LiN (C 2 F 5 SO 2) 2, lithium Fluorine-containing organic lithium salts such as cyclic 1,2-tetrafluoroethanedisulfonylimide and lithium cyclic 1,3-hexafluoropropanedisulfonylimide, lithium bis (oxalato) borate, lithium difluorooxalatoborate, lithium tris ( Oxalato) phosphate, lithium difluorobis (oxalato) phosphate, dicarboxylic acid complex lithium salt such as lithium tetrafluorooxalatophosphate is preferably used in combination.

When used in combination LiPF ₆ and LiBF ₄ are the content of LiBF ₄ to the total of LiPF ₆ and LiBF ₄ is preferably 0.01 mass% or more, more preferably 0.0
5 mass% or more, more preferably 0.1 mass% or more, preferably 20 mass% or less, more preferably 10 mass% or less, still more preferably 5 mass% or less, and particularly preferably 3 mass% or less.
By being in the above range, desired effects can be easily obtained, and deterioration of battery characteristics such as high load discharge characteristics can be prevented.

On the other hand, inorganic lithium salts such as LiPF ₆ and LiBF ₄ and LiCF ₃ SO ₃ and LiN
Fluorine-containing organic materials such as (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , lithium cyclic 1,2-tetrafluoroethanedisulfonylimide, and lithium cyclic 1,3-hexafluoropropane disulfonylimide When using lithium salt or lithium salt of dicarboxylic acid complex such as lithium bis (oxalato) borate, lithium difluorooxalatoborate, lithium tris (oxalato) phosphate, lithium difluorobis (oxalato) phosphate, lithium tetrafluorooxalatophosphate The content of the inorganic lithium salt in the total of both is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 85% by mass or more, preferably 99% by mass or less, more preferably 95% by mass. % Or less

  The concentration of these electrolytes in the non-aqueous electrolyte solution is not particularly limited in order to exhibit the effects of the present invention, but is preferably 0.5 mol / liter or more, more preferably 0.8 mol / liter or more. More preferably, it is 1.0 mol / liter or more. Further, it is preferably 3 mol / liter or less, more preferably 2 mol / liter or less, still more preferably 1.8 mol / liter or less, and particularly preferably 1.6 mol / liter or less. By being in the said range, the electrical conductivity of electrolyte solution becomes enough, and the fall of the electrical conductivity by a viscosity rise and the fall of battery performance are prevented.

(Non-aqueous solvent)
The non-aqueous solvent can also be appropriately selected from conventionally known solvents for non-aqueous electrolyte solutions. For example, cyclic carbonates, chain carbonates, cyclic carboxylic acid esters, chain carboxylic acid esters, cyclic ethers, chain ethers, sulfur-containing organic solvents, phosphorus-containing organic solvents, aromatic fluorine-containing solvents, etc. Can be mentioned.

  Examples of the cyclic carbonates include alkylene carbonates having an alkylene group having 2 to 4 carbon atoms such as ethylene carbonate, propylene carbonate, and butylene carbonate. Among these, ethylene carbonate and propylene carbonate are preferable from the viewpoint of improving battery characteristics. In particular, ethylene carbonate is preferred. Further, a part of hydrogen of these compounds may be substituted with fluorine.

  Examples of cyclic carbonates substituted with fluorine include fluoroethylene carbonate, 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, tetrafluoroethylene carbonate, 1-fluoro- Such as 2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, etc. Examples include alkylene carbonates having an alkylene group substituted with fluorine having 2 to 4 carbon atoms. Among these, fluoroethylene carbonate, 1,2-difluoroethylene carbonate, trifluoromethyl Ethylene carbonate is preferred.

As the chain carbonates, dialkyl carbonates are preferable, and the number of carbon atoms of the alkyl group constituting each is preferably 1 to 5, particularly preferably 1 to 4. Specifically, for example, symmetric chain alkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-n-propyl carbonate; asymmetric chain alkyls such as ethyl methyl carbonate, methyl-n-propyl carbonate, and ethyl-n-propyl carbonate Examples include carbonates, and among them, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are preferable from the viewpoint of improving battery characteristics. Further, a part of hydrogen of the alkyl group may be substituted with fluorine. Examples of chain carbonates substituted with fluorine include bis (fluoromethyl) carbonate, bis (difluoromethyl) carbonate, bis (trifluoromethyl) carbonate, bis (2-fluoroethyl) carbonate, and bis (2,2-difluoroethyl). ) Carbonate, bis (2,2,2-trifluoroethyl) carbonate, 2-fluoroethyl methyl carbonate, 2,2-difluoroethyl methyl carbonate,
Examples include 2,2,2-trifluoroethyl methyl carbonate.

  Examples of the cyclic carboxylic acid esters include γ-butyrolactone, γ-valerolactone, and the like, and compounds obtained by substituting a part of hydrogen of these compounds with fluorine. Examples of chain carboxylates include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, sec-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, propion Examples include isopropyl acid, methyl butyrate, ethyl butyrate, propyl butyrate, methyl valerate, ethyl valerate, etc., and compounds in which part of hydrogen of these compounds such as propyl trifluoroacetate and butyl trifluoroacetate is substituted with fluorine. Methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, and methyl valerate are more preferred.

Examples of the cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran and the like, and compounds obtained by substituting a part of hydrogen of these compounds with fluorine.
Examples of the chain ethers include dimethoxyethane, diethoxyethane, and the like, and compounds obtained by substituting a part of hydrogen of these compounds with fluorine. 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane, 1,1,1,2,2,3,4,5 , 5,5-decafluoro-3-ethoxy-4-trifluoromethyl-pentane, 1,1,1,2,2,3,4,5,5,5-decafluoro-3-propoxy-4-tri Fluoromethyl-pentane, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 2,2-difluoroethyl-2,2,3,3- Tiger fluoropropyl ether.

Examples of the sulfur-containing organic solvent include sulfolane, 2-methylsulfolane, 3-methylsulfolane, diethylsulfone, ethylmethylsulfone, methylpropylsulfone, and the like, and compounds in which part of hydrogen of these compounds is substituted with fluorine.
Examples of the phosphorus-containing organic solvent include trimethyl phosphate, triethyl phosphate, dimethyl ethyl phosphate, methyl diethyl phosphate, ethylene methyl phosphate, ethylene ethyl phosphate, etc., and compounds in which part of hydrogen of these compounds is substituted with fluorine Is mentioned.

Examples of the aromatic fluorine-containing solvent include fluorobenzene, difluorobenzene, trifluorobenzene, tetrafluorobenzene, pentafluorobenzene, hexafluorobenzene, benzotrifluoride and the like.
These may be used alone or in combination of two or more, but it is preferable to use in combination of two or more. For example, it is preferable to use a high dielectric constant solvent such as cyclic carbonates or cyclic carboxylic acid esters in combination with a low viscosity solvent such as chain carbonates or chain carboxylic acid esters.

  One preferable combination of the non-aqueous solvents is a combination mainly composed of alkylene carbonate and dialkyl carbonate. Among them, the total of alkylene carbonate and dialkyl carbonate in the non-aqueous solvent is preferably 70% by volume or more, more preferably 80% by volume or more, still more preferably 90% by volume or more, and alkylene carbonate and dialkyl carbonate. The proportion of the alkylene carbonate with respect to the total of is preferably 5% by volume or more, more preferably 10% by volume or more, still more preferably 15% by volume or more, preferably 50% by volume or less, more preferably 35% by volume or less, still more preferably Is 30% by volume or less, particularly preferably 25% by volume or less. When a combination of these non-aqueous solvents is used, the balance between the cycle characteristics and high-temperature storage characteristics (particularly, the remaining capacity and high-load discharge capacity after high-temperature storage) of a battery manufactured using the non-aqueous solvent may be improved.

As the alkylene carbonate, ethylene carbonate, propylene carbonate, and fluoroethylene carbonate are preferable from the viewpoint of improving the cycle characteristics and high-temperature storage characteristics of the battery.
Specific examples of preferred combinations of ethylene carbonate and dialkyl carbonate include ethylene carbonate and dimethyl carbonate, ethylene carbonate and diethyl carbonate, ethylene carbonate and ethyl methyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate and ethyl methyl. Examples thereof include carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

A combination in which propylene carbonate is further added to a combination of these ethylene carbonate and dialkyl carbonates is also mentioned as a preferable combination.
In the case of containing propylene carbonate, the volume ratio of ethylene carbonate to propylene carbonate is preferably 99: 1 to 40:60, particularly preferably 95: 5 to 50:50. Furthermore, the proportion of propylene carbonate in the whole non-aqueous solvent is preferably 0.1% by volume or more, more preferably 1% by volume or more, still more preferably 2% by volume or more, and preferably 20% by volume or less, more preferably Is 8% by volume or less, more preferably 5% by volume or less. It is preferable to contain propylene carbonate in this concentration range because the low temperature characteristics may be further improved while maintaining the combination characteristics of ethylene carbonate and dialkyl carbonate.

  Among the combinations of ethylene carbonate and dialkyl carbonate, those containing asymmetrical chain alkyl carbonates as dialkyl carbonate are more preferred, especially ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate. Those containing ethylene carbonate, symmetric chain alkyl carbonates and asymmetric chain alkyl carbonates, such as ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, are preferable because of a good balance between cycle characteristics and large current discharge characteristics. Among them, the asymmetric chain alkyl carbonate is preferably ethyl methyl carbonate, and the alkyl group of the alkyl carbonate preferably has 1 to 2 carbon atoms.

  Specific examples of preferred combinations of fluoroethylene carbonate and dialkyl carbonate include fluoroethylene carbonate and dimethyl carbonate, fluoroethylene carbonate and diethyl carbonate, fluoroethylene carbonate and ethyl methyl carbonate, fluoroethylene carbonate and dimethyl carbonate and diethyl carbonate, and fluoroethylene carbonate. And dimethyl carbonate and ethyl methyl carbonate, fluoroethylene carbonate, diethyl carbonate and ethyl methyl carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

A combination obtained by further adding ethylene carbonate and / or propylene carbonate to the combination of these fluoroethylene carbonate and dialkyl carbonate is also mentioned as a preferable combination.
When diethyl carbonate is contained in the non-aqueous solvent, the proportion of diethyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, and further preferably 25% by volume or more. It is particularly preferably 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, still more preferably 75% by volume or less, and particularly preferably 70% by volume or less. And gas generation during high temperature storage may be suppressed.

  When dimethyl carbonate is contained in the non-aqueous solvent, the proportion of dimethyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, and further preferably 25% by volume or more. It is particularly preferably 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, still more preferably 75% by volume or less, and particularly preferably 70% by volume or less. As a result, the load characteristics of the battery may be improved.

  Further, in the combination mainly composed of the alkylene carbonates and dialkyl carbonates, cyclic carbonates other than the alkylene carbonates and dialkyl carbonates, chain carbonates, cyclic carboxylic acid esters, chain carboxylic acid esters, Other solvents such as cyclic ethers, chain ethers, sulfur-containing organic solvents, phosphorus-containing organic solvents, and aromatic fluorine-containing solvents may be mixed.

Another example of the preferred non-aqueous solvent is an organic solvent selected from the group consisting of ethylene carbonate, propylene carbonate and butylene carbonate, or a mixed solvent consisting of two or more organic solvents selected from the group. It occupies 60% by volume or more. A non-aqueous electrolyte using this mixed solvent may reduce solvent evaporation and liquid leakage even when used at high temperatures. Among them, the total of ethylene carbonate and propylene carbonate in the non-aqueous solvent is preferably 70% by volume or more, more preferably 80% by volume or more, still more preferably 90% by volume or more, and the capacity of ethylene carbonate and propylene carbonate. When the ratio is preferably 30:70 to 60:40, the balance between cycle characteristics and high-temperature storage characteristics may be improved.
In the present specification, the capacity of the non-aqueous solvent is a measured value at 25 ° C., but a measured value at the melting point is used for a solid at 25 ° C. such as ethylene carbonate.

(Other compounds)
The nonaqueous electrolytic solution according to the present invention is a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate, and a difluorophosphate within a range not impairing the effects of the present invention. Various other compounds such as at least one compound selected from the group consisting of and a conventionally known overcharge inhibitor may be contained as an auxiliary agent.
Among these, when containing at least one compound selected from the group consisting of a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate, and a difluorophosphate, a negative electrode In order to form a highly stable film, cycle characteristics and battery characteristics after high-temperature storage may be improved, which is preferable.

((Cyclic carbonate compound having a carbon-carbon unsaturated bond))
Examples of the cyclic carbonate compound having a carbon-carbon unsaturated bond include vinylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 1,2-dimethyl vinylene carbonate, 1,2-diethyl vinylene carbonate, fluoro vinylene carbonate, trifluoromethyl. Vinylene carbonate compounds such as vinylene carbonate; vinyl ethylene carbonate, 1-methyl-2-vinylethylene carbonate, 1-ethyl-2-vinylethylene carbonate, 1-n-propyl-2-vinylethylene carbonate, 1-methyl-2- Vinyl ethylene carbonate compounds such as vinyl ethylene carbonate, 1,1-divinyl ethylene carbonate, 1,2-divinyl ethylene carbonate; 1,1-dimethyl-2- Chi Ren ethylene carbonate, methylene ethylene carbonate compounds such as 1,1-diethyl-2-methylene-ethylene carbonate. Among these, vinylene carbonate, vinyl ethylene carbonate, and 1,2-divinyl ethylene carbonate are preferable from the viewpoint of improving cycle characteristics and capacity maintenance characteristics after high-temperature storage, among which vinylene carbonate or vinyl ethylene carbonate is more preferable, and vinylene carbonate is particularly preferable. preferable. These may be used alone or in combination of two or more.
When using 2 or more types together, it is preferable to use together vinylene carbonate and vinyl ethylene carbonate.

((Cyclic carbonate compound having fluorine atom))
Examples of the cyclic carbonate compound having a fluorine atom include fluoroethylene carbonate, 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, tetrafluoroethylene carbonate, 1- Fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate Etc. Of these, fluoroethylene carbonate, 1,2-difluoroethylene carbonate, and 1-fluoro-2-methylethylene carbonate are preferable from the viewpoint of improving cycle characteristics and high-temperature storage characteristics. These may be used alone or in combination of two or more.
In addition, it may be used in combination with a cyclic carbonate compound having a carbon-carbon unsaturated bond and the monofluorophosphate and difluorophosphate described below, and is used in combination from the viewpoint of improving cycle characteristics and high-temperature storage characteristics. Is preferred.

((Monofluorophosphate and difluorophosphate))
The counter cation of monofluorophosphate and difluorophosphate is not particularly limited, but lithium, sodium, potassium, magnesium, calcium, and NR ¹ R ² R ³ R ⁴ (wherein R ^{1 to} R ⁴ Are each independently a hydrogen atom or carbon number 1-12.
Represents an organic group of An ammonium etc. which are represented by this is mentioned as an example.

Although there is no particular limitation on the organic group having 1 to 12 carbon atoms represented by R ¹ to R ⁴ of the above ammonium, for example, which may be substituted with a halogen atom an alkyl group, substituted with a halogen atom or an alkyl group Examples thereof include an cycloalkyl group which may be substituted, an aryl group which may be substituted with a halogen atom or an alkyl group, and a nitrogen atom-containing heterocyclic group which may have a substituent. Among these, as R ^{1 to} R ⁴ , a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group is preferable.

Specific examples of monofluorophosphate and difluorophosphate include lithium monofluorophosphate, sodium monofluorophosphate, potassium monofluorophosphate, tetramethylammonium monofluorophosphate, tetraethylammonium monofluorophosphate, difluoro Examples include lithium phosphate, sodium difluorophosphate, potassium difluorophosphate, tetramethylammonium difluorophosphate, tetraethylammonium difluorophosphate, etc., preferably lithium monofluorophosphate and lithium difluorophosphate, more preferably lithium difluorophosphate. preferable.
These may be used alone or in combination of two or more. Moreover, you may use together with the cyclic carbonate compound which has a carbon-carbon unsaturated bond, and the cyclic carbonate compound which has a fluorine atom, and it is preferable to use together from the point of a cycling characteristic improvement or the characteristic improvement after high temperature storage.

When the non-aqueous electrolyte contains a cyclic carbonate compound having a carbon-carbon unsaturated bond, the proportion in the non-aqueous electrolyte is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, More preferably 0.1% by mass or more, particularly preferably 0.3% by mass or more, preferably 8% by mass or less, more preferably 4% by mass or less, and further preferably 3% by mass.
It is below mass%. When the ratio of the cyclic carbonate compound having a carbon-carbon unsaturated bond is within the above range, the effect of improving the cycle characteristics of the battery and the capacity maintenance characteristics after high temperature storage can be sufficiently exhibited. This prevents an increase in the amount of gas generated and a decrease in discharge characteristics at low temperatures.

  When the non-aqueous electrolyte contains a cyclic carbonate compound having a fluorine atom as an auxiliary agent, the proportion in the non-aqueous electrolyte is preferably 0.001% by mass or more, more preferably 0.1% by mass or more, and further Preferably it is 0.3% by mass or more, particularly preferably 0.5% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 4% by mass or less, particularly preferably 3% by mass. It is as follows.

When the ratio of the cyclic carbonate compound having a fluorine atom is within the above range, the effect of improving the cycle characteristics and high-temperature storage characteristics of the battery can be sufficiently exerted, the amount of gas generation increases during high-temperature storage, and discharge at low temperatures. Prevents deterioration of properties.
When the non-aqueous electrolyte contains a monofluorophosphate and / or difluorophosphate, the proportion in the non-aqueous electrolyte is preferably 0.001% by mass or more, more preferably 0.01% by mass or more. More preferably, it is 0.1% by mass or more, particularly preferably 0.2% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 2% by mass or less.
When the ratio of monofluorophosphate and / or difluorophosphate is within the above range, the effect of improving the cycle characteristics and high-temperature storage characteristics of the battery can be sufficiently exerted, and it becomes difficult to dissolve in the electrolyte. Prevent the tendency of the effect to saturate.

  Conventionally known overcharge inhibitors include alkylbiphenyls such as biphenyl, 2-methylbiphenyl, 2-ethylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclopentylbenzene, cyclohexylbenzene, cis-1-propyl-4 -Phenylcyclohexane, trans-1-propyl-4-phenylcyclohexane, cis-1-butyl-4-phenylcyclohexane, trans-1-butyl-4-phenylcyclohexane, toluene, ethylbenzene, t-butylbenzene, t-amylbenzene , Diphenyl ether, dibenzofuran, methyl phenyl sulfonate, ethyl phenyl sulfonate, diphenyl sulfonate, triphenyl phosphate, tris (2-t-butylphenyl) phosphate, tris (3-t- Tilphenyl) phosphate, tris (4-t-butylphenyl) phosphate, tris (2-t-amylphenyl) phosphate, tris (3-t-amylphenyl) phosphate, tris (4-t-amylphenyl) phosphate, tris ( Aromatic compounds such as 2-cyclohexylphenyl) phosphate, tris (3-cyclohexylphenyl) phosphate, tris (4-cyclohexylphenyl) phosphate; 2-fluorobiphenyl, 3-fluorobiphenyl, 4-fluorobiphenyl, 4,4′- Partially fluorinated products of the above aromatic compounds such as difluorobiphenyl, 2,4-difluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene; 2,4-difluoroanisole, 2,5-difur Roanisoru, 2,6-difluoro anisole, 3,5-difluoro anisole, etc. fluorinated anisole compound of the like.

Among these, alkylbiphenyl such as biphenyl and 2-methylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclopentylbenzene, cyclohexylbenzene, cis-1-propyl-4-phenylcyclohexane, trans-1-propyl-4- Phenylcyclohexane, cis-1-butyl-4-phenylcyclohexane, trans-1-butyl-4-phenylcyclohexane, toluene, ethylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, methylphenylsulfonate, diphenylsulfonate, Aromatic compounds such as triphenyl phosphate, tris (4-t-butylphenyl) phosphate, tris (4-cyclohexylphenyl) phosphate; Preferred are partial fluorinated products of the above aromatic compounds such as benzene, 3-fluorobiphenyl, 4-fluorobiphenyl, 4,4′-difluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene, and partial hydrogenation of terphenyl. , Cyclopentylbenzene, cyclohexylbenzene, cis-1-propyl-4-phenylcyclohexane, trans-1-propyl-4-phenylcyclohexane, cis-1-butyl-4-phenylcyclohexane, trans-1-butyl-4-phenyl Cyclohexane, t-butylbenzene, t-amylbenzene, methylphenylsulfonate, diphenylsulfonate, triphenylphosphate, tris (4-t-butylphenyl) phosphate, tris (4-cyclohexylsulfate) Yl) phosphate, o- cyclohexyl fluorobenzene, p- cyclohexyl fluorobenzene more preferably, partially hydrogenated member and cyclohexylbenzene terphenyl is particularly preferred.

  Two or more of these may be used in combination. When two or more types are used in combination, in particular, a partially hydrogenated terphenyl, a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, or a partially hydrogenated biphenyl, alkylbiphenyl, terphenyl or terphenyl. It is overcharged to use together those selected from oxygen-free aromatic compounds such as cyclohexylbenzene, t-butylbenzene, t-amylbenzene and those selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran. This is preferable from the viewpoint of the balance between prevention characteristics and high-temperature storage characteristics.

  The content ratio of these overcharge inhibitors in the non-aqueous electrolyte is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, still more preferably 0.3% by mass or more, and particularly preferably 0%. 0.5% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 2% by mass or less. By being in the said range, the effect of the desired overcharge inhibiting agent will fully express, and the fall of the characteristics of a battery, such as a high temperature storage characteristic, will be prevented.

Other auxiliaries include carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate, methoxyethyl-ethyl carbonate, ethoxyethyl-methyl carbonate, ethoxyethyl-ethyl carbonate; succinic anhydride Carboxylic acids such as glutaric anhydride, maleic anhydride, itaconic anhydride, citraconic anhydride, glutaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic anhydride, cyclopentanetetracarboxylic dianhydride and phenylsuccinic anhydride Anhydride: dimethyl succinate, diethyl succinate, diallyl succinate, dimethyl maleate, diethyl maleate, diallyl maleate, dipropyl maleate, dibutyl maleate, bis maleate (trifluoro Dicarboxylic acid diester compounds such as bis (pentafluoroethyl) maleate, bis (2,2,2-trifluoroethyl) maleate; 2,4,8,10-tetraoxaspiro [5.5] undecane Spiro compounds such as 3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane; ethylene sulfite, propylene sulfite, 1,3-propane sultone, 1,4-butane sultone, 1,3-propene sultone, 1,4-butene sultone, methyl methanesulfonate, ethyl methanesulfonate, methyl-methoxymethanesulfonate, methyl-2-methoxyethanesulfonate, busulfan, diethylene glycol dimethanesulfonate, 1,2-ethanediol bis ( 2,2,2-Trifluo Ethanesulfonate), 1,4-butanediol bis (2,2,2-trifluoroethanesulfonate), sulfolane, 3-sulfolene, 2-sulfolene, dimethylsulfone, diethylsulfone, divinylsulfone, diphenylsulfone, bis (methylsulfonyl) ) Methane, bis (methylsulfonyl) ethane, bis (ethylsulfonyl) methane, bis (ethylsulfonyl) ethane, bis (vinylsulfonyl) methane, bis (vinylsulfonyl) ethane, N, N-dimethylmethanesulfonamide, N, N -Sulfur-containing compounds such as diethylmethanesulfonamide, N, N-dimethyltrifluoromethanesulfonamide, N, N-diethyltrifluoromethanesulfonamide; 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl Nitrogen-containing compounds such as 2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide; heptane, octane, nonane, decane, cycloheptane, methylcyclohexane, ethylcyclohexane, propylcyclohexane, n -Hydrocarbon compounds such as butylcyclohexane, t-butylcyclohexane, dicyclohexyl; fluorinated benzenes such as fluorobenzene, difluorobenzene, pentafluorobenzene, hexafluorobenzene; 2-fluorotoluene, 3-fluorotoluene, 4-fluorotoluene, Fluorinated toluene such as benzotrifluoride; Nitto such as acetonitrile, propionitrile, butyronitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, etc. Methyl dimethyl phosphinate, ethyl dimethyl phosphinate, ethyl diethyl phosphinate, trimethylphosphonoformate, triethylphosphonoformate, trimethylphosphonoacetate, triethylphosphonoacetate, trimethyl-3-phosphonopropionate, Examples thereof include phosphorus-containing compounds such as triethyl-3-phosphonopropionate. Among these, ethylene sulfite, 1,3-propane sultone, 1,4-butane sultone, 1,3-propene sultone, 1,4-butene sultone, busulfan, 1,4 in terms of improving battery characteristics after high-temperature storage -Sulfur-containing compounds such as butanediol bis (2,2,2-trifluoroethanesulfonate); nitrile compounds such as acetonitrile, propionitrile, butyronitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, and pimelonitrile are preferable.

  Two or more of these may be used in combination. The content ratio of these auxiliaries in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.2% by mass or more. Yes, preferably 8% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, and particularly preferably 1% by mass or less. The addition of these auxiliaries is preferable in terms of improving capacity maintenance characteristics and cycle characteristics after high-temperature storage. When the content ratio is within the above range, the effect of the auxiliary agent is sufficiently exhibited, and deterioration of battery characteristics such as high load discharge characteristics is prevented.

(Preparation of electrolyte)
The nonaqueous electrolytic solution according to the present invention can be prepared by dissolving an electrolyte, a compound represented by the general formula (I), and, if necessary, other compounds in a nonaqueous solvent. In preparing the non-aqueous electrolyte solution, each raw material is preferably dehydrated in advance in order to reduce the water content when the electrolyte solution is used. The dehydration is preferably performed to 50 ppm or less, more preferably 30 ppm or less, and even more preferably 10 ppm or less. Moreover, you may implement dehydration, a deoxidation process, etc. after electrolyte solution preparation.
The non-aqueous electrolyte solution of the present invention is suitable for use as a non-aqueous electrolyte solution for a secondary battery, that is, a non-aqueous electrolyte secondary battery, for example, a lithium secondary battery, among non-aqueous electrolyte batteries. Hereinafter, a non-aqueous electrolyte secondary battery using the non-aqueous electrolyte of the present invention will be described.

<Non-aqueous electrolyte secondary battery>
The non-aqueous electrolyte secondary battery of the present invention is a non-aqueous electrolyte battery including a negative electrode and a positive electrode capable of occluding and releasing lithium ions, and a non-aqueous electrolyte, and the non-aqueous electrolyte is a non-aqueous electrolyte of the present invention. It is an aqueous electrolyte solution.

(Battery configuration)
The non-aqueous electrolyte secondary battery according to the present invention can occlude and release lithium ions as in the case of a conventionally known non-aqueous electrolyte secondary battery except that it is produced using the non-aqueous electrolyte of the present invention. A non-aqueous electrolyte battery including a negative electrode and a positive electrode and a non-aqueous electrolyte solution. Usually, the positive electrode and the negative electrode are accommodated in a case through a porous film impregnated with the non-aqueous electrolyte solution of the present invention. can get. Therefore, the shape of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and may be any of a cylindrical shape, a square shape, a laminate shape, a coin shape, a large size, and the like.

(Negative electrode active material)
The negative electrode active material is not particularly limited as long as it can occlude and release lithium ions. Specific examples thereof include carbonaceous materials, alloy-based materials, lithium-containing metal composite oxide materials, and the like.
These negative electrode active materials may be used alone or in combination of two or more. Of these, carbonaceous materials and alloy materials are preferred.

Among the carbonaceous materials, amorphous carbon materials, graphite, and those in which the surface of graphite is coated with amorphous carbon compared to graphite are preferred, and in particular, the surface of graphite or graphite is amorphous compared to graphite. Those coated with carbon are generally preferred because of their high energy density.
Graphite preferably has a lattice plane (002 plane) d value (interlayer distance) of 0.335 to 0.338 nm, particularly 0.335 to 0.337 nm, as determined by X-ray diffraction using the Gakushin method. The crystallite size (Lc) determined by X-ray diffraction by the Gakushin method is preferably 10 nm or more, more preferably 50 nm or more, and still more preferably 100 nm or more. The ash content is preferably 1% by mass or less, more preferably 0.5% by mass or less, and still more preferably 0.1% by mass or less.

  The graphite surface coated with amorphous carbon is preferably graphite having a d-value of 0.335 to 0.338 nm on the lattice plane (002 plane) in X-ray diffraction as a core material. A carbonaceous material having a larger d-value on the lattice plane (002 plane) in X-ray diffraction than the core material is attached, and the d-value on the lattice plane (002 plane) in X-ray diffraction is greater than that of the core material and the core material. The ratio with respect to the carbonaceous material having a large is 99/1 to 80/20 in mass ratio. When this is used, a negative electrode having a high capacity and hardly reacting with the electrolytic solution can be produced.

The particle size of the carbonaceous material is a median diameter by a laser diffraction / scattering method, preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, particularly preferably 7 μm or more, preferably 100 μm or less, more preferably Is 50 μm or less, more preferably 40 μm or less, and particularly preferably 30 μm or less.
The specific surface area of the carbonaceous material by the BET method is preferably 0.3 m ² / g or more, more preferably 0.5 m ² / g or more, still more preferably 0.7 m ² / g or more, and particularly preferably 0.00.
8 m ² / g or more, preferably 25.0 m ² / g or less, more preferably 20.0 m
² / g or less, more preferably 15.0 m ² / g or less, and particularly preferably 10.0 m ² / g or less.

Further, the carbonaceous material is analyzed by Raman spectrum using argon ion laser light, the peak is the peak intensity of the peak _{P A} in the range of 1570~1620cm ^-1 _I A, in the range of 1300~140cm ^-1 P If the peak intensity of the _B was _{I B,} R value represented by the ratio of _{I B} and _{I a (= I B / I} a) is what is preferably in the range of 0.01 to 0.7. Further, the half width of the peak in the range of 1570～1620Cm ^-1 is, 26cm ^-1 or less, are preferred in particular 25 cm ^-1 or less.

The alloy material is not particularly limited as long as it can occlude / release lithium, and single metals and alloys forming lithium alloys, or oxides, carbides, nitrides, silicides, sulfides, and phosphides thereof. Any of these compounds may be used. Preferably, it is a material containing a single metal and an alloy forming a lithium alloy, more preferably a material containing a group 13 and group 14 metal / metalloid element (that is, excluding carbon), and further, aluminum, silicon, and It is preferably a simple metal of tin (which may be hereinafter referred to as “specific metal element”), and an alloy or compound containing these elements.

  Examples of the negative electrode active material having at least one element selected from specific metal elements include a single metal element of any one specific metal element, an alloy composed of two or more specific metal elements, one type, or two or more types An alloy composed of the specific metal element and one or more other metal elements, a compound containing one or more specific metal elements, and oxides, carbides, nitrides of the compounds, Examples include composite compounds such as silicides, sulfides, and phosphides. By using these simple metals, alloys or metal compounds as the negative electrode active material, the capacity of the battery can be increased.

  Moreover, the compound which these complex compounds combined with several elements, such as a metal simple substance, an alloy, or a nonmetallic element, can also be mentioned as an example. More specifically, for example, in silicon and tin, an alloy of these elements and a metal that does not operate as a negative electrode can be used. In addition, for example, in the case of tin, a complex compound containing 5 to 6 kinds of elements in combination with a metal that acts as a negative electrode other than tin and silicon, a metal that does not operate as a negative electrode, and a nonmetallic element can also be used. .

Among these negative electrode active materials, since the capacity per unit mass is large when a battery is formed, any one metal element of a specific metal element, an alloy of two or more specific metal elements, oxidation of a specific metal element A material, carbide, nitride or the like is preferable, and silicon and / or tin metal alone, an alloy, an oxide, carbide, nitride, or the like is particularly preferable because of its large capacity per unit mass.
In addition, although the capacity per unit mass is inferior to that of using a single metal or an alloy, the following compounds containing silicon and / or tin are also preferred because of excellent cycle characteristics.

The element ratio of silicon and / or tin to oxygen is preferably 0.5 or more, more preferably 0.7 or more, still more preferably 0.9 or more, and preferably 1.5 or less, more preferably Silicon and / or tin oxides of 1.3 or less, more preferably 1.1 or less.
The element ratio of silicon and / or tin and nitrogen is preferably 0.5 or more, more preferably 0.7 or more, still more preferably 0.9 or more, and preferably 1.5 or less, more preferably Silicon and / or tin nitride of 1.3 or less, more preferably 1.1 or less.

The element ratio of silicon and / or tin to carbon is preferably 0.5 or more, more preferably 0.7 or more, still more preferably 0.9 or more, and preferably 1.5 or less, more preferably Silicon and / or tin carbides of 1.3 or less, more preferably 1.1 or less.
These alloy materials may be in the form of powder or thin film, and may be crystalline or amorphous.

  The average particle size of the alloy-based material is not particularly limited in order to exhibit the effects of the present invention, but is preferably 50 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less, preferably 0.1 μm or more, More preferably, it is 1 micrometer or more, More preferably, it is 2 micrometers or more. If the particle size is too large, the expansion of the electrode is increased, and the cycle characteristics may be deteriorated. Moreover, when too small, it will become difficult to collect current, and capacity | capacitance may not fully express.

The lithium-containing metal composite oxide material used as the negative electrode active material is not particularly limited as long as it can occlude and release lithium. However, a lithium-titanium composite oxide (hereinafter referred to as “lithium-titanium composite oxide”) (Abbreviated) is preferred.
In addition, a part of lithium or titanium in the lithium titanium composite oxide is selected from the group consisting of other metal elements such as Na, K, Co, Al, Fe, Mg, Cr, Ga, Cu, Zn, and Nb. Those substituted with at least one element are also preferred.

Furthermore, it is a lithium titanium composite oxide represented by Li _x Ti _y M _z O ₄ , and 0.7 ≦ x ≦ 1.5, 1.5 ≦ y ≦ 2.3, and 0 ≦ z ≦ 1.6. It is preferable that the structure at the time of occlusion / release of lithium ions is stable (M is a group consisting of Na, K, Co, Al, Fe, Mg, Cr, Ga, Cu, Zn, and Nb). Represents at least one element selected).

Among them, when Z = 0 of the lithium titanium composite oxide represented by Li _x Ti _y M _z O ₄ , the structure in the case where x and y satisfy any of the following (a) to (c): This is preferable because of a good balance of battery performance.
(A) 1.2 ≦ x ≦ 1.4, 1.5 ≦ y ≦ 1.7, z = 0
(B) 0.9 ≦ x ≦ 1.1, 1.9 ≦ y ≦ 2.1, z = 0
(C) 0.7 ≦ x ≦ 0.9, 2.1 ≦ y ≦ 2.3, z = 0
More preferred representative compositions are Li _4/3 Ti _5/3 O ₄ in (a), Li ₁ Ti ₂ O ₄ in (b), and Li _4/5 Ti _11/5 O ₄ in (c). .
As for the structure when Z ≠ 0, for example, Li _4/3 Ti _4/3 Al _1/3 O ₄ is preferable.

(Positive electrode active material)
The positive electrode active material is not particularly limited as long as it can occlude and release lithium ions. A substance containing lithium and at least one transition metal is preferable, and examples thereof include a lithium transition metal composite oxide and a lithium-containing transition metal phosphate compound.

V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferable as the transition metal of the lithium transition metal composite oxide. Specific examples include lithium-cobalt composite oxides such as LiCoO ₂ and LiNiO ₂ . Examples of the lithium / nickel composite oxide include lithium / manganese composite oxides such as LiMnO ₂ , LiMn ₂ O ₄ , and Li ₂ MnO ₃ . In addition, a part of the transition metal atom that is the main component of the lithium transition metal composite oxide is replaced with another metal, that is, a part of Co in the lithium-cobalt composite oxide is replaced with Al, Ti, V, Cr. , Mn, Fe, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si substituted with other metals, part of Ni in the lithium-nickel composite oxide is Al, Ti, V, Cr, Substituted with other metals such as Mn, Fe, Co, Li, Cu, Zn, Mg, Ga, Zr, Si, and a part of Mn of the lithium-manganese composite oxide Al, Ti, V, Cr, Fe , Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si substituted with other metals, and the like. Among those in which a part of the transition metal atom that is the main component of the lithium transition metal composite oxide is substituted with another metal, LiNi _1-ab Mn _a Co _b O ₂ (a and b are 0 or more and less than 1) Li, except for the case where a and b are both 0), LiNi _1-c- De Co _C Al _d Mg _e O ₂ (c, d, e represents a number from 0 to less than 1, , D, and e are preferably 0), and LiNi _{1 -ab} Mn _a Co _b O ₂ (0 ≦ a <0.4, 0 ≦ b <0.4), LiNi _{1− c-d-e Co c Al} d Mg e O 2 (0 ≦ c <0.3,0 ≦ d <0.1,0 ≦ e <0.05) are preferred, in _{particular, LiNi} 1/3 _{Co 1 / 3} Mn _1/3 O ₂ , LiNi _0.
5 Co _0.3 Mn _0.2 O ₂ , LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.85 Co _0.10 Al _0.03 Mg _0.02 O ₂ is preferred.

As the transition metal of the lithium-containing transition metal phosphate compound, V, Ti, Cr, Mn, Fe, Co, Ni, Cu and the like are preferable. Specific examples include, for example, LiFePO ₄ , Li _3.
Examples thereof include iron phosphates such as F ₂ (PO ₄ ) ₃ and LiFeP ₂ O _{7 and} cobalt phosphates such as LiCoPO ₄ . In addition, a part of the transition metal atom that is the main component of the lithium transition metal phosphate compound is substituted with another metal, that is, a part of Fe of iron phosphates is Al, Ti, V, Cr, Mn, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si and other metals substituted, Co cobalt phosphates part of Co Al, Ti, V, Cr, Mn, Fe , Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si substituted with other metals, and the like.

These positive electrode active materials may be used alone or in combination.
In addition, a material in which a substance (surface adhering substance) having a composition different from that of the substance constituting the main cathode active material is attached to the surface of the cathode active material can be used. Surface adhering substances include aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate and carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate.

  The amount of the surface adhering substance is not particularly limited in order to exhibit the effect of the present invention, but is preferably 0.1 ppm or more, more preferably 1 ppm or more, and still more preferably, by mass with respect to the positive electrode active material. It is used at 10 ppm or more, preferably 20% or less, more preferably 10% or less, and still more preferably 5% or less. The surface adhering substance can suppress the oxidation reaction of the non-aqueous electrolyte solution on the surface of the positive electrode active material, and can improve the battery life. However, when the amount of the adhering quantity is too small, the effect is not sufficiently exhibited. If the amount is too large, the resistance may increase in order to inhibit the entry and exit of lithium ions.

(Manufacture of electrodes)
As the binder for binding the active material, any material can be used as long as it is a material that is stable with respect to the solvent and the electrolytic solution used during electrode production. For example, fluorine resins such as polyvinylidene fluoride and polytetrafluoroethylene, polyolefins such as polyethylene and polypropylene, polymers having unsaturated bonds such as styrene / butadiene rubber, isoprene rubber and butadiene rubber, ethylene-acrylic acid copolymers, An acrylic acid polymer such as an ethylene-methacrylic acid copolymer may be used.

The electrode may contain a thickener, a conductive material, a filler and the like in order to increase mechanical strength and electrical conductivity.
Examples of the thickener include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, and casein.

Examples of the conductive material include metal materials such as copper and nickel, and carbon materials such as graphite and carbon black.
The electrode may be manufactured by a conventional method. For example, it can be formed by adding a binder, a thickener, a conductive material, a solvent or the like to a negative electrode or a positive electrode active material to form a slurry, applying the slurry to a current collector, drying it, and then pressing it.

In addition, a material obtained by adding a binder or a conductive material to an active material is roll-formed as it is to form a sheet electrode, a pellet electrode is formed by compression molding, and an electrode is formed on the current collector by techniques such as vapor deposition, sputtering, or plating. A thin film of material can also be formed.
When graphite is used for the negative electrode active material, the density of the negative electrode active material layer after drying and pressing is preferably 1.45 g / cm ³ or more, more preferably 1.55 g / cm ³ or more, and still more preferably 1.
. 60 g / cm ³ or more, particularly preferably 1.65 g / cm ³ or more, it is.

The density after drying and pressing of the positive electrode active material layer is preferably 2.0 g / cm ³ or more,
More preferably, it is 2.5 g / cm ³ or more, and further preferably 3.0 g / cm ³ or more.
Various types of current collectors can be used, but metals and alloys are usually used. Examples of the current collector for the negative electrode include copper, nickel, and stainless steel, and copper is preferred. Examples of the positive electrode current collector include metals such as aluminum, titanium, and tantalum, and alloys thereof, and aluminum or an alloy thereof is preferable.

(Separator, exterior body)
A porous film (separator) is interposed between the positive electrode and the negative electrode to prevent a short circuit. In this case, the electrolytic solution is used by impregnating the porous membrane. The material and shape of the porous film are not particularly limited as long as it is stable to the electrolytic solution and excellent in liquid retention, and a porous sheet or nonwoven fabric made of a polyolefin such as polyethylene or polypropylene is preferable.

The material of the battery casing used in the battery according to the present invention is also arbitrary, and nickel-plated iron, stainless steel, aluminum or an alloy thereof, nickel, titanium, a laminate film, or the like is used.
The operating voltage of the above-described non-aqueous electrolyte secondary battery of the present invention is usually in the range of 2V to 4.9V.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.
In addition, each evaluation method of the battery obtained by the following Example and the comparative example is shown below.
[Capacity evaluation]
The sheet-like non-aqueous electrolyte secondary battery is charged to 4.1 V with a constant current corresponding to 0.3 C at 25 ° C. in a state of being sandwiched between glass plates in order to improve the adhesion between the electrodes. The battery was discharged to 3V with a constant current of 3C. This is done for 5 cycles to stabilize the battery. In the 4th cycle, after charging to 4.1 V with a constant current of 0.3 C, charging is performed until the current value reaches 0.05 C with a constant voltage of 4.1 V. The initial discharge capacity was determined by discharging to 3 V with a constant current of 0.3C. Here, 1C represents a current value for discharging the reference capacity of the battery in one hour, and, for example, 0.3C represents a current value that is 0.3 times that value.

[Output evaluation]
The battery prepared as described above is charged at a constant current of 0.3C at room temperature from 3V to half the standard capacity of the battery (50% of full charge), and kept in a -30 ° C constant temperature bath for 2 hours or more. After being allowed to stand, the output was measured.
[Overcharge characteristics evaluation]
The battery for which the capacity and output evaluation tests were completed was charged to 4.1 V at a constant current of 0.3 C at 25 ° C., and then charged to a current value of 0.05 C at a constant voltage of 4.1 V. After immersion in a bath and measuring the volume, a current of 0.5 C was applied at 45 ° C., and the current was cut when SOC 180 was reached, and the open circuit voltage (OCV) of the battery after the overcharge test was measured. Next, the volume was measured by immersion in an ethanol bath, and the amount of gas generated from the volume change before and after overcharging was determined.

The lower the OCV of the battery after the overcharge test, the lower the overcharge depth and the higher the safety during overcharge. Further, the larger the amount of gas generated after overcharging, the more preferable the battery that senses this when the internal pressure rises abnormally due to an abnormality such as overcharging and operates the safety valve because the safety valve can be activated earlier. .
In addition, the greater the difference between the amount of gas generated after overcharging and the amount of gas generated during high-temperature storage, etc., prevents the safety valve from malfunctioning during high-temperature storage, etc., while reliably operating the safety valve during overcharging. Is preferable.

[Evaluation of high-temperature storage characteristics]
The battery for which the capacity and output evaluation tests were completed was charged to 4.1 V at a constant current of 0.3 C at 25 ° C., and then charged to a current value of 0.05 C at a constant voltage of 4.1 V. After immersing in a bath and measuring the volume, a high temperature storage test was conducted at 75 ° C. for 72 hours (3 days).

After the high temperature storage test, the battery was cooled to 25 ° C. and then immersed in an ethanol bath to measure the volume, and the amount of gas generated from the volume change before and after high temperature storage was determined.
After the amount of generated gas was measured, it was discharged to 3 V at a constant current of 0.3 C at 25 ° C., and the remaining capacity after the high temperature storage test was measured.
Next, at 25 ° C., after charging to 4.1 V with a constant current of 0.3 C, charging is performed until the current value becomes 0.05 C with a constant voltage of 4.1 V, and 3 V with a constant current of 0.3 C. The 0.3 C discharge capacity after the high temperature storage test was measured. Furthermore, the battery charged to SOC50 is -30 ℃
The output was measured in a constant temperature bath.

Example 1
[Production of positive electrode]
90% by mass of lithium cobalt nickel manganese oxide (LiNi _1/3 Co _1/3 Mn _1/3 O ₂ ) as a positive electrode active material, 7% by mass of acetylene black as a conductive material, and polyvinylidene fluoride as a binder (PVdF) 3% by mass was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of the aluminum foil, dried, and then pressed to obtain a positive electrode.

[Manufacture of negative electrode]
A negative electrode was obtained by mixing 98 parts by mass of graphite powder as a negative electrode active material and 2 parts by mass of PVdF, adding N-methylpyrrolidone into a slurry, and applying and drying on one side of a current collector made of copper. .
[Manufacture of electrolyte]
Under a dry argon atmosphere, vinylene carbonate was added to a mixture of ethylene carbonate, ethyl methyl carbonate and dimethyl carbonate (volume ratio 3: 4: 3) so that the content in the non-aqueous electrolyte solution was 0.5% by mass, Further, 2,2-bis (p-methoxycarbonyloxyphenyl) propane was added so as to be 2.2% by mass, and then sufficiently dried LiPF ₆ was dissolved at a rate of 1.0 mol / liter. The electrolyte was used.

[Manufacture of non-aqueous electrolyte secondary batteries]
The positive electrode, the negative electrode, and the polyethylene separator were laminated in the order of the negative electrode, the separator, the positive electrode, the separator, and the negative electrode to produce a battery element. The battery element was inserted into a bag made of a laminate film in which both surfaces of aluminum (thickness: 40 μm) were coated with a resin layer while projecting positive and negative terminals, and then the electrolyte was poured into the bag and vacuum sealed. The sheet-like battery was manufactured and the overcharge characteristics and the high temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.

(Example 2)
A sheet battery was prepared in the same manner as in Example 1 except that 1.1% by mass of 2,2-bis (p-methoxycarbonyloxyphenyl) propane was added to the electrolyte solution of Example 1, and the overcharge characteristics and The high temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.
(Example 3)
In the electrolytic solution of Example 1, except that 2.4% by mass of 1,1-bis (p-methoxycarbonyloxyphenyl) cyclohexane was added instead of 2,2-bis (p-methoxycarbonyloxyphenyl) propane A sheet battery was prepared in the same manner as in Example 1, and overcharge characteristics and high temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.

Example 4
In the electrolytic solution of Example 1, except that 1.2% by mass of 1,1-bis (p-methoxycarbonyloxyphenyl) cyclohexane was added instead of 2,2-bis (p-methoxycarbonyloxyphenyl) propane A sheet battery was prepared in the same manner as in Example 1, and overcharge characteristics and high temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 1)
A sheet-like battery was produced in the same manner as in Example 1 except that 2,2-bis (p-methoxycarbonyloxyphenyl) propane was not mixed in the electrolyte solution of Example 1, and the overcharge characteristics and the high temperature storage characteristics were obtained. Was evaluated. The evaluation results are shown in Table 1.
(Comparative Example 2)
A sheet-like battery was prepared in the same manner as in Example 1 except that 2% by mass of cyclohexylbenzene was added in place of 2,2-bis (p-methoxycarbonyloxyphenyl) propane in the electrolyte solution of Example 1. Charging characteristics and high temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 3)
A sheet-like battery was prepared in the same manner as in Example 1 except that 1% by mass of cyclohexylbenzene was added in place of 2,2-bis (p-methoxycarbonyloxyphenyl) propane in the electrolyte solution of Example 1. Charging characteristics and high temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.

* Initial capacity, remaining capacity after high-temperature storage, and amount of overcharged gas were normalized with the value of Comparative Example 1 as 1.
As is clear from Table 1, the batteries of Comparative Examples 2 and 3 have a larger amount of gas generated during overcharge than the battery of Comparative Example 1 in which no overcharge additive is added, and the OCV after overcharge is higher. However, the initial output decreased as the amount added increased, and the remaining capacity and output after storage decreased significantly. The batteries of Examples 1 and 3 are inferior in the amount of gas generated after overcharging as compared with Comparative Examples 2 and 3, and the OCV after overcharging is low, so it can be said that the safety during overcharging is high. Further, comparing Examples 1 to 4 with Comparative Examples 2 and 3, even when the addition amount was increased, the initial output was high, the remaining capacity after storage was high, and Comparative Example 1 in which no overcharge additive was added. Not inferior. Therefore, it can be seen that the battery using the non-aqueous electrolyte according to the present invention has high safety during overcharge and excellent high-temperature storage characteristics.

  The non-aqueous electrolyte battery using the non-aqueous electrolyte of the present invention has high capacity and excellent high-temperature continuous charge characteristics while improving safety during overcharge, and therefore can be used for various known applications. Is possible. Specific examples include notebook computers, pen input computers, mobile computers, electronic book players, mobile phones, mobile faxes, mobile copy, mobile printers, headphone stereos, video movies, LCD TVs, handy cleaners, portable CDs, minidiscs, etc. , Walkie Talkie, Electronic Notebook, Calculator, Memory Card, Portable Tape Recorder, Radio, Backup Power Supply, Motor, Automobile, Motorcycle, Motorbike, Bicycle, Lighting Equipment, Toy, Game Equipment, Clock, Electric Tool, Strobe, Camera, Load A power source for leveling, a natural energy storage power source, and the like can be given.

Claims (5)

A non-aqueous electrolytic solution containing an electrolyte and a non-aqueous solvent, wherein the non-aqueous electrolytic solution contains an aromatic compound represented by the general formula (I).

(In general formula (I) ,
R ² represents hydrogen, halogen, an optionally substituted hydrocarbon group, an alkoxy group, an alkoxylcarbonyloxy group, an organic sulfonate group, or a phosphate ester group,
A is an optionally substituted alkylidene group or cycloalkylidene group,
B is an organic carbonyl group, an organic sulfonyl group, or a dialkoxyphosphoryl group,
m represents an integer of 1 to 5,
n represents an integer of 0 to 5,
Further, the aromatic ring in the compound may be substituted with a halogen, an optionally substituted hydrocarbon group, or an alkoxy group. )   The ratio of the compound represented by general formula (I) to a non-aqueous electrolyte solution is 0.001-10 mass%, The non-aqueous electrolyte solution of Claim 1 characterized by the above-mentioned.   In a non-aqueous electrolyte solution containing an electrolyte and a non-aqueous solvent, the non-aqueous electrolyte solution contains a compound that is represented by the general formula (I) and is dissolved in a non-aqueous electrolyte solution having a general composition by more than 0.5% by mass. The non-aqueous electrolyte solution according to claim 1, wherein   Furthermore, it contains at least one compound selected from the group consisting of a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate and a difluorophosphate. The non-aqueous electrolyte solution according to any one of claims 1 to 3.   A non-aqueous electrolyte battery comprising a negative electrode and a positive electrode capable of occluding and releasing lithium ions, and a non-aqueous electrolyte, wherein the non-aqueous electrolyte is a non-aqueous electrolyte according to any one of claims 1 to 4. A non-aqueous electrolyte battery characterized by being an aqueous electrolyte.