Non-aqueous electrolyte and non-aqueous electrolyte battery

Abstract

The present invention is a nonaqueous electrolytic solution characterized by containing an electrolyte, a nonaqueous solvent, and a compound represented by a general formula (A). In formula (A), R1 to R3 each independently represent a hydrogen atom or a C1-C12 hydrocarbon group, and at least one of R1 to R3 is a C1-C12 hydrocarbon group. R4 to R5 each independently represent a hydrogen atom or a C1-C5 hydrocarbon group. R6 represents a hydrogen atom, a C1-C12 hydrocarbon group, or a C1-C12 alkoxy group. One of R4 and R5 and R6 may be bonded to each other and form a ring.

Description

[Technical Field]

[0001] The present invention relates to a nonaqueous electrolyte and a nonaqueous electrolyte battery, and more particularly to a nonaqueous electrolyte containing a specific compound and a nonaqueous electrolyte battery using this nonaqueous electrolyte. [Background technology]

[0002] BACKGROUND ART Non-aqueous electrolyte batteries such as lithium secondary batteries have been put to practical use in a wide range of applications, such as power sources for so-called small consumer devices such as mobile phones such as smartphones and laptop computers, and on-board power sources for driving electric vehicles and the like.

[0003] As a means for improving the battery characteristics of non-aqueous electrolyte batteries, many studies have been conducted in the fields of active materials for positive and negative electrodes and additives for non-aqueous electrolytes.

[0004] For example, Patent Document 1 discloses a study on improving the cycle capacity retention rate and suppressing an increase in the internal resistance of the battery by adding a specific unsaturated silane compound or unsaturated siloxane compound to a non-aqueous electrolyte solution. Patent Document 2 discloses a study on improving the cycle capacity retention rate of a non-aqueous secondary battery having a rated charge voltage of more than 4.2 V by adding a silicon compound having a specific structure to a non-aqueous electrolyte solution. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-134169 [Patent Document 2] Special Publication No. 2014-522078 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, the trend toward higher-capacity lithium batteries for use as power sources in electric vehicles and mobile phones such as smartphones has accelerated, and the proportion of voids within the battery has become smaller than before. Therefore, the large amount of gas generated during initial conditioning is a fatal drawback. Although the effects disclosed in Patent Documents 1 and 2 can be obtained by using the electrolyte solutions described in those documents, there is room for improvement in gas generation during initial conditioning.

[0007] An object of the present invention is to provide a nonaqueous electrolyte that can suppress gas generation during initial conditioning of a nonaqueous electrolyte battery, and a nonaqueous electrolyte battery in which gas generation during initial conditioning is suppressed. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the present inventors have come up with the idea that gas generation during initial conditioning can be suppressed by using a nonaqueous electrolyte solution containing a silicon compound represented by general formula (A), and have completed the present invention.

[0009] <1> A non-aqueous electrolyte solution comprising an electrolyte, a non-aqueous solvent, and a compound represented by the following general formula (A): [ka] (In formula (A), R 1 ~R 3 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R 1 ~R 3 At least one of R is a hydrocarbon group having 1 to 12 carbon atoms. 4 ~R 5 R each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. 6 represents a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. 4 or R 5 Either one of the two and R6 may be bonded to each other to form a ring. <2> The content of the compound represented by the general formula (A) is 0.001% by mass or more and 10% by mass or less with respect to the total amount of the nonaqueous electrolyte solution. <1> The non-aqueous electrolyte solution according to claim 1. <3> Further, the composition contains at least one compound (I) selected from the group consisting of difluorophosphate anion-containing compounds, fluorosulfonate anion-containing compounds, sulfonylimide anion-containing compounds, alkylsulfate anion-containing compounds, and oxalate complex anion-containing compounds, <1> or <2> The non-aqueous electrolyte solution according to claim 1. <4> Further, the composition contains at least one compound (II) selected from the group consisting of a compound represented by general formula (B), a compound represented by general formula (C), a compound represented by general formula (D), and a compound represented by general formula (E), <1> ~ <3> The non-aqueous electrolyte solution according to any one of the preceding claims. [ka] (In formula (B), R 7 ~R 12 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and n represents an integer of 1 to 5. [ka] (In formula (C), R 13 ~R 14 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and k represents an integer of 3 to 6. [ka] (In formula (D), R 15 ~R 17each independently represents a hydrocarbon group having 1 to 12 carbon atoms which may have a hetero atom, or a trialkylsilyl group. 15 ~R 17 may be bonded to each other to form a ring. [ka] (In formula (E), R 21 and R 22 each independently represents an alkylene group having 1 to 10 carbon atoms which may have a substituent. m represents an integer of 0 or 1. When m is 0, the sulfur atom and the oxygen atom form a direct bond. <5> A non-aqueous electrolyte battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, wherein the non-aqueous electrolyte is <1> ~ <4> 10. A non-aqueous electrolyte battery comprising the non-aqueous electrolyte according to any one of claims 1 to 9. <6> The positive electrode has a positive electrode active material, and the positive electrode active material is a transition metal oxide represented by the following composition formula (1): <5> The non-aqueous electrolyte battery according to claim 1. Li a1 Ni b1 M c1 O2(1) (In the above formula (1), a1, b1, and c1 represent numerical values ​​within the range of 0.90≦a1≦1.10, 0.01≦b1≦0.98, and 0.01≦c1<0.50, and b1+c1=1 is satisfied. M represents at least one element selected from the group consisting of Mn, Co, Al, Mg, Zr, Fe, Ti, and Er.) <7> The positive electrode has a positive electrode active material, and the positive electrode active material is a transition metal oxide represented by the following composition formula (2): <6> The non-aqueous electrolyte battery according to claim 1. Li a2 Ni b2 Co c2 M d2 O2(2) (In the above formula (2), a2, b2, c2, and d2 represent numerical values ​​within the range of 0.90≦a2≦1.10, 0.01≦b2≦0.98, 0.01≦c2<0.50, and 0.01≦d2<0.50, and satisfy b2+c2+d2=1. M represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er.) <8> b1 in the formula (1) satisfies 0.40≦b1≦0.98. <6> The non-aqueous electrolyte battery according to claim 1. <9> b2 in the formula (2) satisfies 0.40≦b2≦0.98. <7> The non-aqueous electrolyte battery according to claim 1. <10> The negative electrode has a negative electrode active material and contains a material containing a metal element that can be alloyed with Li and / or a material containing a metalloid element that can be alloyed with Li. <5> ~ <9> 10. The non-aqueous electrolyte battery according to claim 9, <11> the material containing a metal element capable of being alloyed with Li and / or the material containing a metalloid element capable of being alloyed with Li is a material containing Si element; <10> The non-aqueous electrolyte battery according to claim 1. <12> Further, the composition contains at least one compound (III) selected from the group consisting of unsaturated cyclic carbonates and fluorine atom-containing cyclic carbonates. <1> ~ <4> The non-aqueous electrolyte solution according to any one of the preceding claims. <13> Contains an unsaturated cyclic carbonate and a fluorine atom-containing cyclic carbonate, <12> The non-aqueous electrolyte solution according to claim 1. <14> The unsaturated cyclic carbonate is vinylene carbonate. <12> or <13> The non-aqueous electrolyte solution according to claim 1. <15> The fluorine atom-containing cyclic carbonate is fluoroethylene carbonate. <12> ~ <14> The non-aqueous electrolyte solution according to any one of the preceding claims. <16> The compound (I) contains at least one compound selected from the group consisting of a fluorosulfonate anion-containing compound, a sulfonylimide anion-containing compound, an alkylsulfate anion-containing compound, and an oxalate complex anion-containing compound. <3> The non-aqueous electrolyte solution according to claim 1. <17> The compound (I) contains at least one compound selected from the group consisting of a fluorosulfonate anion-containing compound, an alkylsulfate anion-containing compound, and an oxalate complex anion-containing compound. <3> The non-aqueous electrolyte solution according to claim 1. <18> The compound (I) contains at least one compound selected from the group consisting of a fluorosulfonate anion-containing compound and an alkylsulfate anion-containing compound. <3> The non-aqueous electrolyte solution according to claim 1. <19> The compound (II) contains at least one compound selected from the group consisting of a compound represented by general formula (B), a compound represented by general formula (C), and a compound represented by general formula (D). <4> The non-aqueous electrolyte solution according to claim 1. <20> The compound (II) contains at least one compound selected from the group consisting of a compound represented by general formula (B) and a compound represented by general formula (C). <4> The non-aqueous electrolyte solution according to claim 1. <21> The content of the compound (I) is 0.001 to 8% by mass based on the total amount of the nonaqueous electrolyte solution. <3> The non-aqueous electrolyte solution according to claim 1. <22> The content of the compound (I) is 0.001 to 5% by mass based on the total amount of the nonaqueous electrolyte solution. <3> The non-aqueous electrolyte solution according to claim 1. <23> The content of the compound (II) is 0.001 to 10% by mass relative to the total amount of the nonaqueous electrolyte solution. <4> The non-aqueous electrolyte solution according to claim 1. <24> The content of the compound (III) is 0.001 to 10% by mass relative to the total amount of the non-aqueous electrolyte solution. <12> The non-aqueous electrolyte solution according to claim 1. [Effects of the Invention]

[0010] According to the present invention, it is possible to obtain a nonaqueous electrolyte that is excellent in suppressing gas generation during initial conditioning of a nonaqueous electrolyte battery, and a nonaqueous electrolyte battery in which gas generation during initial conditioning is suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples (typical examples) of the present invention, and the present invention is not limited to these. Furthermore, the present invention can be implemented with any modifications within the scope of the gist thereof.

[0012] <1.Non-aqueous electrolyte> The non-aqueous electrolyte solution according to the present invention contains a compound represented by the general formula (A) described below. The mechanism by which gas generation during initial conditioning is suppressed by using a nonaqueous electrolyte solution containing the specific silicon compound represented by general formula (A) is not clear, but is presumed to be as follows.

[0013] The compound represented by the general formula (A) contains a silyl group (-SiR 1 R 2 R 3 ) Generally, silicon atoms have a wide electron cloud and no steric hindrances when forming bonds, so they easily form bonds with π electrons or unpaired electrons via vacant d orbitals. Furthermore, compounds represented by general formula (A) have a carbon-carbon double bond to which a silyl group having at least one hydrocarbon group with 1 to 12 carbon atoms is bonded via an oxygen atom. The increased electron density of the carbon-carbon double bond enhances its reactivity with electrophilic compounds such as Lewis acids. As a result, during initial charging, the compound represented by general formula (A) interacts and reacts with, for example, the unpaired electron of an oxygen atom in the positive electrode active material and the Lewis acid site of a transition metal, forming a highly insulating coating. It is believed that this coating suppresses side reactions in the electrolyte during initial conditioning and reduces the amount of gas generation.

[0014] <1-1. Compound represented by general formula (A)> A non-aqueous electrolyte solution according to one embodiment of the present invention is characterized by containing a silicon compound represented by the following general formula (A): In this specification, the identification and content measurement of compounds such as the silicon compound represented by general formula (A) contained in the non-aqueous electrolyte solution are carried out by nuclear magnetic resonance (NMR) spectroscopy.

[0015] [ka]

[0016] In formula (A), R 1 ~R 3each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R 1 ~R 3 At least one of R is a hydrocarbon group having 1 to 12 carbon atoms. 4 ~R 5 R each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. 6 represents a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. 4 or R 5 Either one of the two and R 6 may be bonded to each other to form a ring.

[0017] The hydrocarbon group having 1 to 12 carbon atoms is preferably a hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 4 carbon atoms. In this specification, the hydrocarbon group may be either linear or branched, and may contain a cyclic structure and / or an unsaturated bond.

[0018] Specific examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and an aralkyl group. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. Among these, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, and a hexyl group are preferred, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, and an n-pentyl group are more preferred, and a methyl group, an ethyl group, an n-butyl group, and a tert-butyl group are particularly preferred. The above-mentioned alkyl groups are preferred because the compound represented by general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0019] Specific examples of the alkenyl group include a vinyl group, an allyl group, a methallyl group, a 2-butenyl group, a 3-methyl-2-butenyl group, a 3-butenyl group, and a 4-pentenyl group. Among these, a vinyl group, an allyl group, a methallyl group, and a 2-butenyl group are preferred, a vinyl group, an allyl group, and a methallyl group are more preferred, and a vinyl group or an allyl group is particularly preferred. The above-mentioned alkenyl groups are preferred because the compound represented by general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0020] Specific examples of the alkynyl group include an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group, and a 5-hexynyl group. Among these, an ethynyl group, a 2-propynyl group, a 2-butynyl group, and a 3-butynyl group are preferred, a 2-propynyl group and a 3-butynyl group are more preferred, and a 2-propynyl group is particularly preferred. The above-mentioned alkynyl groups are preferred because the compound represented by general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0021] Specific examples of the aryl group include a phenyl group and a tolyl group, etc. Among these, a phenyl group is preferred from the viewpoint that the compound represented by general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material. Specific examples of the aralkyl group include a phenylmethyl group (benzyl group), a phenylethyl group (phenethyl group), a phenylpropyl group, a phenylbutyl group, and a phenylisopropyl group, etc. Among these, from the viewpoint of the tendency of the compound represented by general formula (A) to be localized near the surface of the positive electrode active material and / or the negative electrode active material, a benzyl group and a phenethyl group are more preferred, and a benzyl group is particularly preferred.

[0022] The alkoxy group having 1 to 12 carbon atoms is preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably an alkoxy group having 1 to 4 carbon atoms. Specific examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isopropoxy group, etc. Among these, a methoxy group and an ethoxy group are preferred because they cause less steric hindrance to the compound represented by general formula (A) and are suitably concentrated on the surface of the active material. R 1 ~R 3 As for R, from the viewpoint of having little steric hindrance and being able to act suitably on the electrode surface, at least two of them are preferably hydrocarbon groups having 1 to 12 carbon atoms, and from the viewpoint of being able to interact suitably with the reaction points of the positive electrode active material, R 1 ~R 3 It is more preferable that all of R are hydrocarbon groups having 1 to 12 carbon atoms. 1 ~R 3 More preferably, all of R are alkyl groups having 1 to 6 carbon atoms. 1 ~R 3 It is particularly preferable that all of the groups are alkyl groups having 1 to 4 carbon atoms.

[0023] R 4 or R 5 Either one of the two and R 6 may be bonded to each other to form a ring. From the viewpoint of having little steric hindrance and being able to act favorably on the electrode surface, R 5 and R 6 In the present specification, R 4 , R 5 and R 6 is R 4 and R 6 and R bonded to each other to form a ring 5 and R 6 and a carbon-carbon bond formed by bonding together to form a ring also include a group formed when one carbon-carbon bond is broken. R 5 , R 6 and R 4 and R 5 The carbon to which the Si-O bond and R 6 Examples of alicyclic carbon rings formed by a carbon-carbon double bond with the carbon to which the carbon atom is bonded include cyclobutene, cyclohexene, and 1,3-cyclohexadiene. Among them, R is the most suitable for stability in electrolytes. 5 and R6 The divalent hydrocarbon group formed from -(CH2) n - (n is an integer of 3 to 6), that is, R 5 , R 6 is preferably an alkyl group and is bonded to form a ring. Also, R 5 and R 6 In an embodiment in which the divalent hydrocarbon group formed from 5 , R 6 It is particularly preferred that are alkyl or alkenyl groups and are bonded to form a ring. R 1 ~R 6 As a combination of 1 ~R 3 are each independently an alkyl group having 1 to 12 carbon atoms; R 4 ~R 5 are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; R 6 is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms (R 4 ~R 5 and R 6 and R may form a ring. 1 ~R 3 are each independently an alkyl group having 1 to 6 carbon atoms; R 4 ~R 5 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 6 is an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms (R 4 ~R 5 and R 6 and (may form a ring) is more preferred. From the viewpoint of compound availability, R 1 ~R 3 are each independently an alkyl group having 1 to 6 carbon atoms; R 4 ~R 5 are each independently an alkyl group having 1 to 6 carbon atoms; R 6 is preferably an alkoxy group having 1 to 6 carbon atoms. In order to suppress gas generation during initial conditioning, 1 ~R 3 are each independently an alkyl group having 1 to 6 carbon atoms; R 4 ~R 5 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 6 is preferably an alkenyl group having 2 to 6 carbon atoms. From the viewpoint of suppressing side reactions in the electrolyte, R 1 ~R 3 are each independently an alkyl group having 1 to 6 carbon atoms; R 4 ~R 5 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 6 is an alkyl group having 1 to 6 carbon atoms (R 4 ~R 5 and R 6 and R may form a ring. 1 ~R 3 are each independently an alkyl group having 1 to 6 carbon atoms; R 4 ~R 5 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 6 is an alkyl group having 1 to 6 carbon atoms, and R 4 ~R 5 and R 6 and form a ring is more preferable.

[0024] R 1 ~R 6 The combination is not particularly limited, but R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R5 is a hydrogen atom, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkoxy group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkoxy group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R5 is a hydrogen atom, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkoxy group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkoxy group; It is preferable that the combination of

[0025] Among them, R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is a hydrogen atom; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkynyl group; It is more preferable that the combination of

[0026] Among them, R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkyl group; R 1 ~R 3is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is a hydrogen atom, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is a hydrogen atom, R 5 is an alkyl group, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is a hydrogen atom, R 6 is an alkynyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkyl group; R 1 ~R3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkenyl group; R 1 ~R 3 is an alkyl group, R 4 is an alkyl group, R 5 is an alkyl group, R 6 is an alkynyl group; It is more preferable that the combination of

[0027] Specific examples of the compound represented by general formula (A) include compounds having the following structures.

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] The compound represented by formula (A) may be used alone or in combination of two or more kinds. The content of the compound represented by general formula (A) relative to the total amount of the nonaqueous electrolytic solution according to one embodiment of the present invention is not particularly limited, but is usually 0.001 to 10% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less. It is preferably 0.001 to 5.0% by mass, more preferably 0.001 to 3.0% by mass, even more preferably 0.001 to 1.0% by mass, and particularly preferably 0.001 to 0.5% by mass. When the nonaqueous electrolytic solution contains two or more compounds represented by general formula (A), the total amount of these compounds is taken as the content of compound (A). When the content of the compound represented by general formula (A) relative to the total amount of the nonaqueous electrolyte solution is within the above range, the concentration of the compound in the active material proceeds favorably, and it becomes possible to produce a battery that generates little gas during initial conditioning. The compound represented by general formula (A) may be a commercially available product or may be synthesized and used.

[0039] <1-2. Electrolytes> The non-aqueous electrolyte solution of this embodiment, like a general non-aqueous electrolyte solution, usually contains an electrolyte as a component. The electrolyte used in the non-aqueous electrolyte solution of this embodiment is not particularly limited as long as it is an alkali metal salt, and lithium salts such as LiBF4, LiPF6, LiN(FSO2)2, LiN(CF3SO2)2, and lithium difluorooxalatoborate are preferably used, more preferably LiBF4, LiPF6, and LiN(CF3SO2)2, and more preferably LiPF6. These lithium salts can also be used alone or in combination of two or more.

[0040] The total concentration of alkali metal salts in the non-aqueous electrolyte is not particularly limited, but is usually 8% by mass or more, preferably 8.5% by mass or more, and more preferably 9% by mass or more, relative to the total amount of the non-aqueous electrolyte. It is also usually 18% by mass or less, preferably 17% by mass or less, and more preferably 16% by mass or less. It is preferably 8.5% by mass to 17% by mass, and more preferably 9% by mass to 16% by mass. When the total concentration of alkali metal salts in the electrolyte is within the above range, the electrical conductivity is appropriate for battery operation, and sufficient output characteristics tend to be obtained. However, when an electrolyte compound corresponding to <1-4. Auxiliary Agent> is contained in a non-aqueous electrolyte solution, an electrolyte other than a lithium salt corresponding to the auxiliary agent is necessarily contained. Furthermore, when the content of the electrolyte compound is 5.0 mass% or less, it is classified as an "auxiliary agent" in this specification. Therefore, even if a "compound corresponding to the auxiliary agent" corresponds to an "electrolyte" as a component of the non-aqueous electrolyte solution of this embodiment, the amount of the "electrolyte" does not include the amount of the "compound corresponding to the auxiliary agent."

[0041] <1-3. Non-aqueous solvents> The nonaqueous electrolyte solution of this embodiment, like a general nonaqueous electrolyte solution, usually contains a nonaqueous solvent as its main component that dissolves the above-mentioned electrolyte. There are no particular limitations on the nonaqueous solvent, and known organic solvents can be used. Examples of organic solvents include saturated cyclic carbonates such as ethylene carbonate, propylene carbonate, and butylene carbonate; linear carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; carboxylic acid esters such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; ether compounds such as dimethoxymethane, diethoxymethane, ethoxymethoxymethane, tetrahydrofuran, 1,3-dioxane, and 1,4-dioxane; sulfone compounds such as 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, dimethyl sulfone, ethyl methyl sulfone, and monofluoromethyl methyl sulfone; and the like. Preferred are saturated cyclic carbonates, chain carbonates, and carboxylic acid esters, and more preferred are saturated cyclic carbonates and chain carbonates. These non-aqueous solvents can be used alone or in combination of two or more.

[0042] <1-4. Auxiliaries> The nonaqueous electrolyte solution of this embodiment may contain an auxiliary agent within a range that allows the effects of the present invention to be achieved. As an auxiliary agent, Difluorophosphate anion-containing compounds; Fluorosulfonate anion-containing compounds; Sulfonylimide anion-containing compounds; Alkyl sulfate anion-containing compounds; Oxalate anion-containing compounds; Unsaturated cyclic carbonates such as vinylene carbonate, vinylethylene carbonate, and ethynylethylene carbonate; fluorinated cyclic carbonates such as monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, and 4,5-difluoro-4,5-dimethylethylene carbonate; Carbonate compounds such as methoxyethyl-methyl carbonate; Spiro compounds such as methyl-2-propynyl oxalate; Diisocyanates having a cycloalkylene group, such as 1,3-bis(isocyanatomethyl)cyclohexane; isocyanate compounds such as trimer compounds derived from compounds having at least two isocyanate groups in the molecule, such as triallyl isocyanurate, or aliphatic polyisocyanates obtained by adding a polyhydric alcohol thereto; Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone; hydrocarbon compounds such as cycloheptane; Fluorinated aromatic compounds such as fluorobenzene; Ester compounds such as 2-propynyl 2-(methanesulfonyloxy)propionate; Lithium salts such as lithium ethylmethyloxycarbonylphosphonate; A compound represented by general formula (B): [ka] (In formula (B), R 7 ~R 12 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and n represents an integer of 1 to 5. A compound represented by general formula (C): [ka] (In formula (C), R 13 ~R 14 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and k represents an integer of 3 to 6. A compound represented by general formula (D): [ka] (In formula (D), R 15 ~R 17 each independently represents a hydrocarbon group having 1 to 12 carbon atoms which may have a hetero atom, or a trialkylsilyl group. 15 ~R 17 may be bonded to each other to form a ring. A compound represented by general formula (E): [ka] (In formula (E), R 21 and R 22 each independently represents an alkylene group having 1 to 10 carbon atoms which may have a substituent. m represents an integer of 0 or 1. When m is 0, the sulfur atom and the oxygen atom form a direct bond. These may be used alone or in combination of two or more. The addition of these auxiliary agents can suppress gas generation during initial conditioning and improve capacity retention and cycle characteristics after high-temperature storage.

[0043] In particular, in the nonaqueous electrolyte solution according to one embodiment of the present invention, it is preferable to use one or more compounds selected from difluorophosphate anion-containing compounds, fluorosulfonate anion-containing compounds, oxalate complex anion-containing compounds, and sulfonylimide anion-containing compounds (hereinafter also referred to as "specific anion-containing compounds (compound (I))"), one or more compounds selected from unsaturated cyclic carbonates and fluorine atom-containing cyclic carbonates (hereinafter also referred to as "specific carbonate compounds (compound (III))"), and / or one or more compounds selected from compounds represented by general formula (B), compounds represented by general formula (C), compounds represented by general formula (D), and compounds represented by general formula (E) (hereinafter also referred to as "specific compounds (compound (II))"). The specific anion-containing compound (compound I) is preferably at least one compound selected from the group consisting of fluorosulfonate anion-containing compounds, sulfonylimide anion-containing compounds, alkylsulfate anion-containing compounds, and oxalate complex anion-containing compounds, more preferably at least one compound selected from the group consisting of fluorosulfonate anion-containing compounds, alkylsulfate anion-containing compounds, and oxalate complex anion-containing compounds, and even more preferably at least one compound selected from the group consisting of fluorosulfonate anion-containing compounds and alkylsulfate anion-containing compounds. The specific compound (compound II) is preferably at least one compound selected from the group consisting of compounds represented by general formula (B), compounds represented by general formula (C), and compounds represented by general formula (D), and more preferably at least one compound selected from the group consisting of compounds represented by general formula (B) and compounds represented by general formula (C). Furthermore, when two or more of the specific anion-containing compound, the specific carbonate compound, and the specific compound are used in combination, it is preferable to use a combination of the specific anion-containing compound and the specific carbonate compound, or a combination of the specific compound and the specific carbonate compound. The content of the auxiliary agent is usually 0.001 to 10% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, relative to 100% by mass of the nonaqueous electrolyte solution. It is usually 10% by mass or less, preferably 8% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less. It is preferably 0.001 to 8% by mass, more preferably 0.001 to 5% by mass, and even more preferably 3% by mass or less. When two or more auxiliary agents are used in combination, it is preferable that the total amount falls within the above range.

[0044] [1-4-1. Specific anion-containing compounds] The specific anion-containing compound is usually an acid or a salt, and preferably a salt. The counter cation of the salt of the specific anion-containing compound is not particularly limited, but includes lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR 23 R 24 R 25 R 26 (In the formula, R 23 ~R 26 and each independently represent a hydrogen atom or an organic group having 1 to 12 carbon atoms. Examples include ammonium represented by the following formula: Among these, lithium is preferred.

[0045] The above ammonium R 23 ~R 26 The organic group having 1 to 12 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include an alkyl group which may be substituted with a halogen atom, a cycloalkyl group which may be substituted with a halogen atom or an alkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, or a nitrogen atom-containing heterocyclic group which may have a substituent. 23 ~R 26 are each preferably independently a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group.

[0046] (difluorophosphate anion) The difluorophosphate anion may be used alone or in any combination and ratio of two or more. The content of difluorophosphate salts (the total content when two or more types are used) relative to the total amount of the nonaqueous electrolyte is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention, but is typically 0.001 to 8% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and most preferably 1.5% by mass or less. It is preferably 0.001 to 5.0% by mass, more preferably 0.001 to 3.0% by mass, even more preferably 0.001 to 2.0% by mass, and most preferably 0.001 to 1.5% by mass. If the content of difluorophosphate anions is within this range, initial gas generation can be suitably suppressed.

[0047] (fluorosulfonate anion) The fluorosulfonate anions may be used alone or in any combination and ratio of two or more. The content of fluorosulfonates (total content when two or more types are used) relative to the total amount of the nonaqueous electrolyte is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention, but is typically 0.001 to 8 mass%, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and preferably 5.0 mass% or less, more preferably 3.0 mass% or less, even more preferably 2.0 mass% or less, and most preferably 1.5 mass% or less. It is preferably 0.001 to 5.0 mass%, more preferably 0.001 to 3.0 mass%, even more preferably 0.001 to 2.0 mass%, and most preferably 0.001 to 1.5 mass%. If the content of the fluorosulfonate anion is within this range, the initial gas generation can be suitably suppressed.

[0048] (sulfonylimide anion) Specific examples of sulfonylimide anions include N - (FSO2)2, N - (FSO2)(CF3SO2), N - (CF3SO2)2, N - (C2F5SO2)2, cyclic 1,2-perfluoroethanedisulfonylimide anion, cyclic 1,3-perfluoropropanedisulfonylimide anion, N - (CF3SO2)(C4F9SO2), and N - (FSO2)2, N - (CF3SO2)2, N - (C2F5SO2)2 is preferred, especially N - (FSO2)2 is preferred.

[0049] The sulfonylimide anions may be used alone or in any combination and ratio of two or more. The content of sulfonylimide anions (total content when two or more types are used) relative to the total amount of the nonaqueous electrolyte is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention. It is usually 0.001 to 8% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and most preferably 1.5% by mass or less. It is preferably 0.001 to 5.0% by mass, more preferably 0.001 to 3.0% by mass, even more preferably 0.001 to 2.0% by mass, and most preferably 0.001 to 1.5% by mass. If the content of the sulfonylimide anion is within this range, the initial gas generation can be suitably suppressed.

[0050] (Alkyl sulfate anion) Specific examples of alkyl sulfate anions include C n H 2n+1 OSO3 - (1≦n≦10), and a methyl sulfate anion or an ethyl sulfate anion is preferred. The content of alkyl sulfate anions is not particularly limited and can be any amount as long as it does not significantly impair the effects of the present invention, but is usually 0.001 to 8% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and most preferably 1.5% by mass or less. Preferably, it is 0.001 to 5.0% by mass, more preferably 0.001 to 3.0% by mass, even more preferably 0.001 to 2.0% by mass, and most preferably 0.001 to 1.5% by mass. If the content of alkyl sulfate anions is within this range, initial gas generation can be suitably suppressed.

[0051] (oxalate complex anion) Specific examples of the oxalate complex anion include an (oxalate)borate anion, a bis(oxalate)borate anion, a tetrafluorooxalate phosphate anion, a difluorobis(oxalate)phosphate anion, and a tris(oxalate)phosphate anion. Bis(oxalate)borate and difluorobis(oxalate)phosphate anions are preferred, and a bis(oxalate)borate anion is particularly preferred.

[0052] The oxalate complex anions may be used alone or in any combination of two or more in any ratio. The content of the oxalate complex anions (the total content when two or more types are used) is not particularly limited and can be any content as long as it does not significantly impair the effects of the present invention, but is usually 0.001 to 8% by mass, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and most preferably 1.5% by mass or less. Preferably, it is 0.001 to 5.0% by mass, more preferably 0.001 to 3.0% by mass, even more preferably 0.001 to 2.0% by mass, and most preferably 0.001 to 1.5% by mass. If the content of the oxalate complex anion is within this range, the initial gas generation can be suppressed.

[0053] [1-4-2. Specific carbonate compounds] The non-aqueous electrolyte preferably contains at least one carbonate compound selected from the group consisting of unsaturated cyclic carbonates having a carbon-carbon unsaturated bond and cyclic carbonates having a fluorine atom. Among these, it is preferable to contain an unsaturated cyclic carbonate, and more preferable to contain vinylene carbonate. These can be used alone or in combination of two or more in any ratio. It is preferable to contain an unsaturated cyclic carbonate and a fluorinated cyclic carbonate, more preferably vinylene carbonate and a fluorinated cyclic carbonate, or an unsaturated cyclic carbonate and monofluoroethylene carbonate, and even more preferably vinylene carbonate and monofluoroethylene carbonate.

[0054] (Unsaturated cyclic carbonate) The unsaturated cyclic carbonate is not particularly limited as long as it is a cyclic carbonate having a carbon-carbon double bond or a carbon-carbon triple bond. Cyclic carbonates having an aromatic ring are also included in the unsaturated cyclic carbonate.

[0055] Examples of unsaturated cyclic carbonates include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring, a carbon-carbon double bond, or a carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, catechol carbonates, etc. Among these, vinylene carbonates and ethylene carbonates substituted with a substituent having an aromatic ring, a carbon-carbon double bond, or a carbon-carbon triple bond are preferred.

[0056] Examples of vinylene carbonates include vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, and 4,5-diallyl vinylene carbonate. Examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond include vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5-vinyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl-5-ethynyl ethylene carbonate, phenyl ethylene carbonate, 4,5-diphenyl ethylene carbonate, 4-phenyl-5-vinyl ethylene carbonate, 4-allyl-5-phenyl ethylene carbonate, allyl ethylene carbonate, 4,5-diallyl ethylene carbonate, and 4-methyl-5-allyl ethylene carbonate. Among these, vinylene carbonate, vinylethylene carbonate, and ethynylethylene carbonate are preferred because they form a more stable composite coating on the electrode, and one or more selected from vinylene carbonate and vinylethylene carbonate are more preferred, with vinylene carbonate being even more preferred. The unsaturated cyclic carbonates can be used alone or in combination of two or more kinds in any ratio.

[0057] (Fluorine atom-containing cyclic carbonate) The fluorine atom-containing cyclic carbonate is not particularly limited as long as it has a cyclic carbonate structure and contains a fluorine atom. Examples of cyclic carbonates having fluorine atoms include fluorinated cyclic carbonates having an alkylene group with 2 to 6 carbon atoms, and derivatives thereof, such as fluorinated ethylene carbonate (fluoroethylene carbonate) and derivatives thereof, and ethylene carbonate having a fluorine-containing group. Examples of derivatives of fluorinated ethylene carbonate include fluorinated ethylene carbonate substituted with an alkyl group (e.g., an alkyl group with 1 to 4 carbon atoms). Among these, fluoroethylene carbonate having 1 to 8 fluorine atoms and derivatives thereof are preferred.

[0058] Examples of fluoroethylene carbonate and derivatives thereof having 1 to 8 fluorine atoms, and ethylene carbonate having a fluorine-containing group include monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4-(fluoromethyl)-ethylene carbonate, 4-(difluoromethyl)-ethylene carbonate, 4-(trifluoromethyl)-ethylene carbonate, 4-(fluoromethyl)-4-fluoroethylene carbonate, 4-(fluoromethyl)-5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene carbonate, and 4,4-difluoro-5,5-dimethylethylene carbonate. Among these, from the viewpoint of imparting high ionic conductivity to the electrolyte and facilitating the formation of a stable interface protective coating, one or more selected from monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate are preferred. The fluorine atom-containing cyclic carbonates can be used alone or in combination of two or more kinds in any ratio.

[0059] (Content of specific carbonate compounds) The content of the specific carbonate compound (total amount when two or more types are used) in the total amount of the nonaqueous electrolyte solution is usually 0.001 to 10 mass%, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, even more preferably 0.5 mass% or more, and preferably 8.0 mass% or less, more preferably 6.0 mass% or less, even more preferably 5.0 mass% or less, preferably 0.001 to 10 mass%, more preferably 0.001 to 8.0 mass%, even more preferably 0.001 to 6.0 mass%, and most preferably 0.001 to 5.0 mass%. When the content of the specific carbonate compound is within the above range, gas generation during initial conditioning can be significantly suppressed. Although the reason for this is unclear, it is thought that the inclusion of the carbonate compound at this ratio forms a coating on the electrode, minimizing side reactions of the components of the non-aqueous electrolyte solution and thereby suppressing gas generation during initial conditioning. The identification and content of specific carbonate compounds is determined by nuclear magnetic resonance (NMR) spectroscopy.

[0060] (Mass Ratio of Compound Represented by General Formula (A) to Specific Carbonate Compound) The mass ratio of the content of the specific carbonate compound (total amount when two or more types are used) to the content of the compound represented by general formula (A) (specific carbonate compound [g] / compound represented by general formula (A) [g]) is typically 1 to 200. It is preferably 3 or more, more preferably 5 or more, and preferably 100 or less, more preferably 70 or less, and even more preferably 50 or less. It is preferably 1 to 100, more preferably 1 to 70, and even more preferably 1 to 50. When the mass ratio is within the above range, gas generation during initial conditioning can be significantly suppressed. While the reason for this is unclear, it is thought that the inclusion of the specific carbonate compound within the above mass ratio range forms a coating on the electrode, minimizing side reactions of the components of the nonaqueous electrolyte solution and thereby suppressing gas generation during initial conditioning.

[0061] (mass ratio of electrolyte to specific carbonate compound) In the nonaqueous electrolyte solution, the mass ratio (g of specific carbonate compound / g of electrolyte) of the content of the specific carbonate compound (total amount when two or more types are used) to the content of the electrolyte (preferably LiPF6) is typically 0.001 to 0.8. It is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, and is preferably 0.5 or less, more preferably 0.4 or less, and even more preferably 0.35 or less. It is preferably 0.001 to 0.5, more preferably 0.001 to 0.4, and even more preferably 0.001 to 0.35. When the mass ratio is within the above range, gas generation during initial conditioning can be significantly suppressed. While the reason for this is unclear, it is thought that by including the specific carbonate compound and electrolyte within the above mass ratio range, a coating is formed on the electrode, minimizing side reactions of the electrolyte within the battery system and thereby suppressing gas generation during initial conditioning.

[0062] [1-4-3. Specific Compounds] (Compound represented by general formula (B)) [ka] In formula (B), R 7 ~R 12 each independently represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. n represents an integer of 1 to 5.

[0063] R 7 ~R 12 is preferably a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and more preferably a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. When the hydrocarbon group has a substituent, the number of carbon atoms contained in the substituent is determined by R 7 ~R 12The number of carbon atoms in the hydrocarbon group is not included in the number of carbon atoms in the hydrocarbon group. Examples of halogen atoms include fluorine atoms, chlorine atoms, and bromine atoms. A fluorine atom is preferred in view of the reduced occurrence of electrochemical side reactions. Specific examples of the unsubstituted hydrocarbon group and alkoxy group include R 1 ~R 6 Examples of such examples include: R 7 ~R 12 At least one of the groups is preferably a hydrocarbon group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond, from the viewpoint that the compound represented by general formula (B) tends to be suitably localized on the electrode surface. Specific examples of the hydrocarbon group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond include the above-mentioned alkenyl group having 2 to 12 carbon atoms, alkynyl group having 2 to 12 carbon atoms, and aryl group having 6 to 12 carbon atoms. Among these, an alkenyl group having 2 to 12 carbon atoms or an alkynyl group having 2 to 12 carbon atoms is preferred, from the viewpoint that the compound represented by general formula (B) tends to be suitably localized on the electrode surface, and an alkenyl group having 2 to 12 carbon atoms is particularly preferred. R 7 ~R 12 may be the same or different, but it is preferable that at least two or more are the same in terms of ease of compound synthesis, and it is more preferable that three or more are the same in terms of the above.

[0064] Here, the substituents include a cyano group, an isocyanato group, an acyl group (—(C═O)—R a ), acyloxy group (-O(C=O)-R a ), alkoxycarbonyl group (-(C=O)OR a ), sulfonyl group (-SO2-R a ), sulfonyloxy group (-O(SO2)-R a ), alkoxysulfonyl group (-(SO2)-OR a ), alkoxysulfonyloxy group (-O-(SO2)-OR a ), alkoxycarbonyloxy group (-O-(C=O)-OR a ), ether group (-OR a), halogen (preferably fluorine), trifluoromethyl group, etc. a represents an alkyl group having 1 to 10 carbon atoms, an alkylene group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. Among these substituents, a cyano group, an isocyanato group, an acyloxy group (—O(C═O)—R a ), halogen (preferably fluorine), trifluoromethyl group, and more preferably isocyanato group, acyloxy group (—O(C═O)—R a ), halogen (preferably fluorine), trifluoromethyl group, and particularly preferably an acyloxy group (—O(C═O)—R a ), halogen (preferably fluorine), trifluoromethyl group.

[0065] In formula (B), n is preferably an integer of 1 to 3, more preferably 1 or 2. When n is within this range, the molecular size of the compound represented by general formula (B) is appropriate, and it becomes easier to favorably interact with the electrode.

[0066] (Compound represented by general formula (C)) [ka] In formula (C), R 13 ~R 14 each independently represents a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group of 1 to 12 carbon atoms, or an optionally substituted alkoxy group of 1 to 12 carbon atoms. k represents an integer of 3 to 6.

[0067] R 13 ~R 14is preferably a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and particularly preferably a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. When the hydrocarbon group has a substituent, the number of carbon atoms contained in the substituent is determined by R 13 ~R 14 The carbon number of the hydrocarbon group is not included in the carbon number of the hydrocarbon group. Also, R 13 ~R 14 At least one of the groups is preferably a hydrocarbon group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond, from the viewpoint that the compound represented by general formula (C) tends to be suitably localized on the electrode surface. Examples of the hydrocarbon group having 2 to 12 carbon atoms and a carbon-carbon unsaturated bond include an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms, which will be described later. Of these, an alkenyl group having 2 to 12 carbon atoms or an alkynyl group having 2 to 12 carbon atoms is preferred, from the viewpoint that the compound represented by general formula (C) tends to be suitably localized on the electrode surface, and an alkenyl group having 2 to 12 carbon atoms is particularly preferred. R 13 ~R 14 may be the same or different, but it is preferable that they are both the same in terms of ease of compound synthesis. Here, examples of the halogen atom, the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and the alkoxy group having 1 to 12 carbon atoms which may have a substituent include R 7 ~R 12 Examples of such examples include:

[0068] In formula (C), k is preferably 3 to 5, and more preferably 3 or 4.

[0069] Specific examples of the compounds represented by general formula (B) or (C) include compounds having the following structures.

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] Preferred examples of the compound represented by general formula (B) or (C) include the following compounds. [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] More preferred compounds include the following: [ka]

[0080] [ka]

[0081] Particularly preferred are the following compounds: [ka]

[0082] The content of the compound represented by general formula (B) and / or (C) relative to the total amount of the nonaqueous electrolyte solution according to one embodiment of the present invention is typically 0.001 to 10% by mass. It is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more. It is also preferably 8.0% by mass or less, more preferably 6.0% by mass or less, even more preferably 4.0% by mass or less, particularly preferably 3.0% by mass or less, particularly preferably 2.5% by mass or less, and most preferably 2.0% by mass or less. It is preferably 0.001 to 3.0% by mass, more preferably 0.001 to 2.5% by mass, and even more preferably 0.001 to 2.0% by mass. When the nonaqueous electrolyte solution contains two or more compounds represented by general formula (B) and / or (C), the total amount of these compounds is taken as the content of the compound represented by general formula (B) and / or (C). When the content of the compound represented by general formula (B) and / or (C) relative to the total amount of the nonaqueous electrolyte solution is within the above range, the concentration of the compound represented by general formula (B) and / or (C) in the active material proceeds favorably, and it becomes possible to produce a battery that generates little gas during initial conditioning.

[0083] (Compound represented by general formula (D)) The non-aqueous electrolyte solution according to one embodiment of the present invention may contain a compound represented by the following general formula (D).

[0084] [ka] In general formula (D), R 15 ~R 17each independently represents a hydrocarbon group having 1 to 12 carbon atoms which may have a hetero atom, or a trialkylsilyl group. 15 ~R 17 may be bonded to each other to form a ring.

[0085] R 15 ~R 17 When the hydrocarbon group represented by R 15 ~R 17 The hydrocarbon group which may have a hetero atom is not included in the number of carbon atoms of the hydrocarbon group as defined above. The hydrocarbon group which may have a hetero atom means that the hydrocarbon group may have a substituent containing a monovalent hetero atom substituting a hydrogen atom, or may have a divalent substituent containing a hetero atom substituting a group containing a carbon atom (e.g., a methylene group) in the hydrocarbon group. The hydrocarbon group having 1 to 12 carbon atoms is preferably a hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 4 carbon atoms.

[0086] Specific examples of the hydrocarbon group include R 1 ~R 3 Examples of such examples include:

[0087] Examples of the heteroatom include an oxygen atom, a sulfur atom, a nitrogen atom, a phosphorus atom, and a halogen atom. Examples of monovalent substituents containing heteroatoms include cyano groups, isocyanato groups, and acyl groups (-(C=O)-R a ), acyloxy group (-O(C=O)-R a ), alkoxycarbonyl group (-(C=O)OR a ), sulfonyl group (-SO2-R a ), sulfonyloxy group (-O(SO2)-R a ), alkoxysulfonyl group (-(SO2)-OR a ), alkoxysulfonyloxy group (-O-(SO2)-OR a ), alkoxycarbonyloxy group (-O-(C=O)-OR a ), ether group (-OR a), halogen (preferably fluorine), trifluoromethyl group, etc. a represents an alkyl group having 1 to 10 carbon atoms, an alkylene group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. Among these substituents, a cyano group, an isocyanato group, an acyloxy group (—O(C═O)—R a ), halogen (preferably fluorine), trifluoromethyl group, and more preferably isocyanato group, acyloxy group (—O(C═O)—R a ), halogen (preferably fluorine), trifluoromethyl group, and particularly preferably an acyloxy group (—O(C═O)—R a ), halogen (preferably fluorine), trifluoromethyl group. Examples of the heteroatom of the divalent substituent containing a heteroatom substituting a group containing a carbon atom (e.g., a methylene group) in the hydrocarbon group include an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom. From the viewpoint of strengthening the interaction with the compound represented by general formula (A), a phosphorus atom or a nitrogen atom is preferred, and a nitrogen atom is particularly preferred. Note that R 15 ~R 17 When any one of the above has a heteroatom, the lone electron pair of the heteroatom may be coordinated to the boron atom.

[0088] Specific examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a tributylsilyl group, a triisopropylsilyl group, and a tert-butyldimethylsilyl group. From the viewpoint of less steric hindrance and favorable interaction with the compound represented by general formula (A), a trimethylsilyl group and a triethylsilyl group are preferred.

[0089] Also, R 15 ~R 17 may be bonded to each other to form a ring. 15 ~R 17 are bonded to each other to form a ring, R 15 ~R 17Two of R may be bonded to each other to form a ring, 15 ~R 17 All combinations of may be linked together.

[0090] R according to general formula (D) 15 ~R 17 may be the same or different, but it is preferable that at least two or more are the same in terms of ease of compound synthesis, and it is more preferable that all three are the same from the above-mentioned viewpoint. In addition, from the viewpoint that the compound represented by general formula (D) easily interacts sterically with the compound represented by general formula (A), R 15 ~R 17 are preferably bonded to each other to form a ring, and R 15 ~R 17 More preferably, are bonded to each other via a heteroatom to form a ring.

[0091] In the compound represented by general formula (D), R 15 ~R 17 A specific example of a boron-containing cyclic compound in which all of the above are bonded to each other via a heteroatom to form a ring is a compound represented by general formula (D'). [ka]

[0092] R according to general formula (D') 18 ~R 20 are each independently an alkylene group having 1 to 12 carbon atoms which may have a substituent, preferably an alkylene group having 1 to 6 carbon atoms, and particularly preferably an alkylene group having 2 to 4 carbon atoms. 1 ~R 6Examples of the substituent include alkylene groups obtained by removing one hydrogen atom from the alkyl groups exemplified above. Examples include methylene, methylmethylene, ethylmethylene, dimethylmethylene, diethylmethylene, methylethylene, dimethylene (ethylene), trimethylene (propylene), and tetramethylene (butylene). Specific examples of the substituent include the groups exemplified as monovalent substituents containing heteroatoms.

[0093] X contains at least a trivalent or pentavalent heteroatom, such as a phosphorus atom (P), P=O, or a nitrogen atom (N). A nitrogen atom is particularly preferred. The lone electron pair of the heteroatom X may be coordinated to boron. R according to general formula (D') 18 ~R 20 may be the same or different, but it is preferable that at least two of them are the same in terms of ease of compound synthesis, and it is more preferable that all three of them are the same in terms of the above.

[0094] Specific examples of the compound represented by general formula (D) include compounds having the following structures.

[0095] [ka]

[0096] Preferred examples of the compounds include the following: [ka]

[0097] More preferred compounds include the following: [ka]

[0098] More preferred compounds include the following: [ka]

[0099] Particularly preferred are boron-containing cyclic compounds such as triethanolamine borate and / or trimethylsilyl borate.

[0100] The compound represented by general formula (D) may be used alone or in combination of two or more. The content of the compound represented by general formula (D) relative to the total amount of the nonaqueous electrolytic solution according to one embodiment of the present invention is usually 0.001 to 10% by mass. It is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.5% by mass or less. It is preferably 0.001 to 3.0% by mass, more preferably 0.001 to 2.0% by mass, and even more preferably 0.01 to 1.5% by mass. When the nonaqueous electrolytic solution contains two or more compounds represented by general formula (D), the total amount thereof is the content of the compound represented by general formula (D). When the content of the compound represented by general formula (D) relative to the total amount of the nonaqueous electrolyte solution is within the above range, the concentration of the compound in the active material proceeds favorably, and it becomes possible to produce a battery that generates little gas during initial conditioning.

[0101] (Compound represented by general formula (E)) [ka] In formula (E), R 21 and R 22 each independently represents an alkylene group having 1 to 10 carbon atoms which may have a substituent, and m represents an integer of 0 or 1. When m is 0, the sulfur atom and the oxygen atom form a direct bond.

[0102] R 21 When m=0, is preferably an alkylene group having 1 to 5 carbon atoms which may have a substituent, more preferably an alkylene group having 1 to 3 carbon atoms which may have a substituent, and particularly preferably an alkylene group having 2 to 3 carbon atoms which may have a substituent. Also, R 21 When m=1, is preferably an alkylene group having 1 to 5 carbon atoms which may have a substituent, more preferably an alkylene group having 1 to 3 carbon atoms which may have a substituent, and particularly preferably a methylene group which may have a substituent. R 22 As the alkylene group, an alkylene group having 1 to 5 carbon atoms which may have a substituent is preferred, an alkylene group having 1 to 3 carbon atoms which may have a substituent is more preferred, and an optionally substituted methylene group is particularly preferred. When the hydrocarbon group has a substituent, the number of carbon atoms contained in the substituent is R 21 ~R 22 The carbon number of the hydrocarbon group is not included in the carbon number of the hydrocarbon group.

[0103] Specific examples of the alkylene group include a methylene group, an ethylene group, an n-propylene group, a butylene group, and a hexylene group.

[0104] Here, the substituents include hydrocarbon groups having 1 to 12 carbon atoms, cyano groups, isocyanato groups, and acyl groups (-(C=O)-R a ), acyloxy group (-O(C=O)-R a ), alkoxycarbonyl group (-(C=O)OR a ), sulfonyl group (-SO2-R a ), sulfonyloxy group (-O(SO2)-R a ), alkoxysulfonyl group (-(SO2)-OR a ), alkoxysulfonyloxy group (-O-(SO2)-OR a ), alkoxycarbonyloxy group (-O-(C=O)-OR a ), alkoxy group (-OR a ), a halogen atom (preferably a fluorine atom), a trifluoromethyl group, etc. a represents an alkyl group having 1 to 12 carbon atoms, an alkylene group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkynyl group having 2 to 12 carbon atoms. Among these substituents, preferred are hydrocarbon groups having 1 to 12 carbon atoms, cyano groups, isocyanato groups, and acyloxy groups (—O(C═O)—R a ), alkoxycarbonyl group (-(C=O)OR a ), sulfonyloxy group (-O(SO2)-R a ), a halogen atom (preferably a fluorine atom), or a trifluoromethyl group, and more preferably a hydrocarbon group having 1 to 12 carbon atoms, an isocyanato group, or an alkoxycarbonyl group (-(C=O)OR a ), sulfonyloxy group (-O(SO2)-R a ), acyloxy group (-O(C=O)-R a ), a halogen atom (preferably a fluorine atom), or a trifluoromethyl group, and particularly preferably a hydrocarbon group having 1 to 10 carbon atoms, or an alkoxycarbonyl group (—(C═O)OR a ), sulfonyloxy group (-O(SO2)-R a ), a halogen atom (preferably a fluorine atom), or a trifluoromethyl group.

[0105] Specific examples of the hydrocarbon group include R 1 ~R 3 Examples of such examples include:

[0106] Specific examples of the compound represented by formula (E) include the following compounds. [ka]

[0107] Preferred are the following compounds: [ka]

[0108] More preferably, the following compounds are used: [ka]

[0109] Particularly preferred are the following compounds: [ka]

[0110] The content of the compound represented by general formula (E) relative to the total amount of the nonaqueous electrolytic solution according to one embodiment of the present invention is usually 0.001 to 10% by mass. It is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.5% by mass or less. It is preferably 0.001 to 3.0% by mass, even more preferably 0.001 to 2.0% by mass, and particularly preferably 0.001 to 1.5% by mass. When the nonaqueous electrolytic solution contains two or more compounds represented by general formula (E), the total amount thereof is taken as the content of the compound represented by general formula (E). When the content of the compound represented by general formula (E) relative to the total amount of the nonaqueous electrolyte solution is within the above range, the concentration of the compound in the active material proceeds favorably, and it becomes possible to produce a battery that generates little gas during initial conditioning.

[0111] <2.Nonaqueous electrolyte battery> A nonaqueous electrolyte battery according to one embodiment of the present invention is a nonaqueous electrolyte battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte solution, the nonaqueous electrolyte solution being the nonaqueous electrolyte solution according to the embodiment described above. More specifically, the battery comprises a current collector and a positive electrode having a positive electrode active material layer on at least a portion of the current collector surface and capable of absorbing and releasing metal ions, a current collector and a negative electrode having a negative electrode active material layer on at least a portion of the current collector surface and capable of absorbing and releasing metal ions, and a nonaqueous electrolyte solution containing a compound represented by the general formula (A) above together with an alkali metal salt and a nonaqueous solvent.

[0112] [2-1. Battery configuration] The nonaqueous electrolyte battery of this embodiment is similar to conventional nonaqueous electrolyte batteries in terms of configuration other than the nonaqueous electrolyte. Typically, a positive electrode and a negative electrode are stacked via a porous membrane (separator) impregnated with the nonaqueous electrolyte, and these are housed in a case (exterior body). The shape of the nonaqueous electrolyte battery of this embodiment is not particularly limited, and may be any of cylindrical, rectangular, laminated, coin, large, etc. However, since laminated batteries are particularly susceptible to swelling due to gas generation, laminated batteries are preferred.

[0113] [2-2. Non-aqueous electrolyte] As the nonaqueous electrolyte solution, the nonaqueous electrolyte solution according to one embodiment of the present invention is used. Note that, within the scope of the present invention, other nonaqueous electrolyte solutions may be blended with the nonaqueous electrolyte solution.

[0114] [2-3. Positive electrode] The positive electrode has a current collector and a positive electrode active material on at least a part of the surface of the current collector. The other components can be those known in the art.

[0115] The positive electrode active material is not particularly limited as long as it can electrochemically absorb and release metal ions, but specific examples include lithium cobalt oxide and transition metal oxides containing at least Ni and Co, with Ni and Co accounting for 50 mol % or more of the transition metals, and materials capable of electrochemically absorbing and releasing lithium ions are preferred, for example, transition metal oxides containing lithium, at least Ni, and Co, with Ni and Co accounting for 60 mol % or more of the transition metals are preferred. This is because Ni and Co have oxidation-reduction potentials suitable for use as positive electrode materials for secondary batteries and are suitable for high-capacity applications.

[0116] Among the transition metal oxides, a transition metal oxide represented by the following composition formula (1) is preferred. Li a1 Ni b1 M C1 O2(1) In the above formula (1), a1, b1, and c1 represent numerical values ​​within the range of 0.90≦a1≦1.10, 0.02≦b1≦0.98, and 0.01≦c1<0.50, and satisfy b1+c1=1. M represents at least one element selected from the group consisting of Mn, Co, Al, Mg, Zr, Fe, Ti, and Er. From the viewpoint of increasing capacity, an embodiment in which 0.40≦b1≦0.98 is preferable, and an embodiment in which 0.50≦b1≦0.98 is more preferable. Moreover, a more preferred embodiment is a transition metal oxide represented by the following composition formula (2). Li a2 Ni b2 Co c2 M d2 O2(2) In the above formula (2), a2, b2, c2, and d2 represent numerical values ​​within the range of 0.90≦a2≦1.10, 0.02≦b2≦0.98, 0.01≦c2<0.50, and 0.01≦d2<0.50, and satisfy b2+c2+d2=1. M represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er. From the viewpoint of increasing capacity, an embodiment in which 0.40≦b2≦0.98 is preferred, and an embodiment in which 0.50≦b2≦0.98 is more preferred. In the composition formula (2), it is preferable that the value d2 satisfies 0.1≦d2<0.5. By setting the composition ratios of Ni and Co and other metal species within the above ranges, there are advantages in that transition metals are less likely to be eluted from the positive electrode, and even if they are eluted, Ni and Co have little adverse effect on the non-aqueous secondary battery. A specific example of a suitable material is LiNi 0.85 Co 0.10 Al 0.05 O2, LiNi 0.80 Co 0.15 Al 0.05 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, Li 1.05 Ni 0.50 Co 0.20 Mn 0.30 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi0.8 Co 0.1 Mn 0.1 Examples include O2.

[0117] [2-4. Negative electrode] The negative electrode has a current collector and a negative electrode active material on at least a part of the surface of the current collector. Other components may be those known in the art.

[0118] The negative electrode active material is not particularly limited as long as it can electrochemically absorb and release metal ions. Specific examples include carbon-based materials, materials containing a metal element capable of alloying with Li, materials containing a metalloid element capable of alloying with Li, lithium-containing metal composite oxide materials, and mixtures thereof. These materials may be used alone or in any combination of two or more. In terms of excellent cycle characteristics, safety, and continuous charge characteristics, negative electrode active materials containing carbon-based materials or materials containing a metal element capable of alloying with Li and / or materials containing a metalloid element capable of alloying with Li are preferred. Negative electrode active materials containing carbon-based materials and materials containing a metal element capable of alloying with Li and / or materials containing a metalloid element capable of alloying with Li are more preferred. Negative electrode active materials containing graphite and materials containing a metal element capable of alloying with Li and / or materials containing a metalloid element capable of alloying with Li are even more preferred.

[0119] Examples of carbonaceous materials include natural graphite, artificial graphite, amorphous carbon, carbon-coated graphite, graphite-coated graphite, and resin-coated graphite, with natural graphite being preferred.

[0120] Examples of natural graphite include scaly graphite, flake graphite, and / or graphite particles obtained by subjecting such graphite to spheroidization or densification. Among these, spherical or ellipsoidal graphite particles that have been subjected to spheroidization are particularly preferred from the viewpoint of particle packing and charge / discharge rate characteristics. The average particle diameter (d50) of the graphite particles is usually 1 μm or more and 100 μm or less.

[0121] Any conventionally known material containing a metal element and / or a metalloid element that can be alloyed with Li can be used, but from the viewpoint of capacity and cycle life, a simple substance of an element selected from the group consisting of Sb, Si, Sn, Al, As, and Zn, or an oxide, nitride, or carbide thereof, for example, is preferred, and a material containing Si element is more preferred. Furthermore, when the material containing a metal element and / or a metalloid element that can be alloyed with Li contains two or more elements, the material may be an alloy material made of an alloy of these elements.

[0122] In this specification, Si or Si-containing compounds are collectively referred to as Si compounds. Specific examples of Si compounds include SiO x ,SiN x ,SiC x , SiZ y O z (Z=C, N), etc. Examples of Si compounds include Si oxides (SiO x ) is preferred because it has a larger theoretical capacity than graphite, and amorphous Si or nano-sized Si crystals are preferred because they allow alkali ions such as lithium ions to easily enter and exit, making it possible to obtain a high capacity. This general formula SiO x is obtained from silicon dioxide (SiO2) and Si as raw materials, and the value of x is usually 0 <x<2である。 Among these, metal Si (hereinafter sometimes referred to as Si) or a Si-containing compound is preferred in terms of increasing capacity, and Si or Si oxide is more preferred. When the material containing a metal element and / or a material containing a metalloid element that can be alloyed with Li is in the form of particles, the average particle diameter (d50) of the particles is usually 0.01 μm or more and 10 μm or less from the viewpoint of cycle life. The mixture of graphite and particles of a material containing a metal element that can be alloyed with Li and / or a material containing a semi-metal element that can be alloyed with Li, used as the negative electrode active material, may be a mixture in which the particles of the material containing a metal element that can be alloyed with Li and / or a material containing a semi-metal element that can be alloyed with Li and the graphite are mixed in the form of particles that are independent of each other, or may be a composite in which the material containing a metal element that can be alloyed with Li and / or a material containing a semi-metal element that can be alloyed with Li is present on the surface or inside of the graphite. The content of the material containing a metal element capable of being alloyed with Li and / or the particles ...

[0123] [2-5. Separator] A separator is usually interposed between the positive electrode and the negative electrode to prevent short circuiting. In this case, the nonaqueous electrolyte solution according to one embodiment of the present invention is usually impregnated into the separator before use. Any conventional separator can be used. [Example]

[0124] Below are examples , reference example, The present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples as long as it does not depart from the gist of the invention.

[0125] This Example , reference example,The compounds used in the comparative examples are shown below.

[0126] [ka] Compound 1 (E-1-methoxy-1-trimethylsilyloxy-1-propene: A-40)

[0127] [ka] Compound 2 (2-trimethylsilyloxy-1-propene: A-1)

[0128] [ka] Compound 3 (2-trimethylsilyloxy-1,3-butadiene: A-6)

[0129] [ka] Compound 4 (1-trimethylsilyloxy-1-cyclohexene: A-36)

[0130] [ka] Compound 5 (Tris(trimethylsilane) phosphate)

[0131] [ka] Compound 6 (bis(dimethylvinyl)silyl ether)

[0132] [ka] Compound 7 (trimethylvinylsilane)

[0133] [ka] Compound 8 (trimethoxyvinylsilane)

[0134] [ka] Compound 9 (1,1,1,3,3,3-hexamethyldisilazane)

[0135] [ka] Compound 10 (N,O-(bistrimethylsilyl)trifluoroacetamide)

[0136] [ka] Compound 11 (ethoxydimethylvinylsilane)

[0137] [ka] Compound 12 (methanesulfonic acid trimethylsilyl ester)

[0138] [ka] Compound 13 (N-methyl-N-trimethylsilyltrifluoroacetamide)

[0139] [ka] Compound 14 (Triethanolamine borate)

[0140] [ka] Compound 15 (Lithium difluorophosphate)

[0141] [ka] Compound 16 (Lithium fluorosulfonate)

[0142] [ka] Compound 17 (Lithium bis(fluorosulfonyl)imide)

[0143] [ka] Compound 18 (Lithium bis(oxalato)borate)

[0144] [ka] Compound 19 (1-t-butyldimethylsilyloxy-1-cyclohexene: A-122)

[0145] [ka] Compound 20 (Ethylene sulfate)

[0146] < Reference example 1~ 7 and 14, Examples 8 to 13 and 15-16 , Comparative Examples 1 to 12> [Preparation of positive electrode] The positive electrode active material was lithium-nickel-cobalt-manganese composite oxide (Li 1.0 Ni 0.5 Co 0.2 Mn 0.390 parts by mass of O2), 7 parts by mass of acetylene black as a conductive material, and 3 parts by mass of polyvinylidene fluoride (PVdF) as a binder were mixed in N-methylpyrrolidone solvent using a disperser to form a slurry. This slurry was evenly applied to both sides of a 15 μm thick aluminum foil, dried, and then pressed to form a positive electrode.

[0147] [Preparation of negative electrode] 98 parts by mass of natural graphite as the negative electrode active material was mixed with 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of sodium carboxymethylcellulose: 1% by mass) as a thickener and 1 part by mass of an aqueous dispersion of styrene-butadiene rubber (concentration of styrene-butadiene rubber: 50% by mass) as a binder, and the mixture was mixed in a disperser to form a slurry. The resulting slurry was applied to one side of a 10 μm thick copper foil, dried, and then pressed to form a negative electrode.

[0148] [Preparation of non-aqueous electrolyte] In a dry argon atmosphere, 1.2 mol / L (14.8 mass% as concentration in the non-aqueous electrolyte) of LiPF6 was dissolved as an electrolyte in a mixture of ethylene carbonate (EC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC) (volume ratio EC:DEC:EMC = 3:3:4). Vinylene carbonate (VC) and fluoroethylene carbonate (FEC) were added to the non-aqueous electrolyte to give a concentration of 2.0 mass%, respectively, to prepare reference electrolyte 1. Compounds 1 to 20 were added to reference electrolyte 1 in the amounts shown in Table 1 below. Reference example 1~ 7 and 14, Examples 8 to 13 and 15 16 ,and Non-aqueous electrolyte solutions were prepared for Comparative Examples 2 to 15. Reference electrolyte solution 1 was used as the non-aqueous electrolyte solution for Comparative Example 1. Note that the "content (mass %)" in the table is the content when the total amount of each non-aqueous electrolyte solution is taken as 100 mass %.

[0149] [Manufacturing non-aqueous electrolyte batteries] The positive electrode, negative electrode, and polyethylene separator were stacked in this order to prepare a battery element. This battery element was inserted into a bag made of a laminate film of aluminum (40 μm thick) coated on both sides with a resin layer so that the positive and negative electrode terminals protruded. The prepared nonaqueous electrolyte solution was then poured into the bag, which was then vacuum-sealed to prepare a laminated nonaqueous electrolyte battery.

[0150] [Evaluation of non-aqueous electrolyte batteries] (Initial conditioning) The battery was charged at a constant current of 0.05 C for 6 hours in a thermostatic chamber at 25°C, then discharged at 0.2 C to 3.0 V. It was then charged at 0.2 C with constant current and constant voltage (CC-CV) to 4.1 V. It was then aged at 45°C for 72 hours. It was then discharged at 0.2 C to 3.0 V to stabilize the laminated battery. It was then charged at 0.2 C with CC-CV to 4.2 V, and then discharged at 0.2 C to 3.0 V for initial conditioning. (Initial conditioning gas generation volume measurement) Before and after the initial conditioning, the battery was immersed in an ethanol bath and the volume was measured, and the amount of gas generated was calculated from the change in volume before and after the initial conditioning, and this was taken as the "initial gas amount." Table 1 below shows the initial gas amounts when the initial gas amount in Comparative Example 1 is set to 100.

[0151] [Table 1]

[0152] From Table 1, Reference example 1~ 7 and 14, Example 8~13 and 15~ It can be seen that the battery produced in 16 had a smaller initial gas amount than the batteries produced in Comparative Examples 1 to 15. It can be seen that the nonaqueous electrolyte batteries using nonaqueous electrolytes containing silicon compounds that have a trialkylsiloxy group but do not fall under the category of compounds represented by formula (A) (e.g., Comparative Examples 2 and 10) have a larger initial gas amount than Comparative Example 1. It can also be seen that Comparative Example 8, which used a nonaqueous electrolyte containing a silicon compound that has neither a trialkylsiloxy group nor a carbon-carbon double bond, has a significantly larger initial gas amount than Comparative Example 1. This is presumably because silicon compounds that do not fall under the category of compounds represented by formula (A) do not effectively form an insulating coating on the surfaces of the positive electrode active material and / or negative electrode active material. Furthermore, the results of Examples 8 to 13 and 15 to 16 show that by using the compound represented by formula (A) in combination with the compound represented by formula (B), the compound represented by formula (D), the difluorophosphate anion-containing compound, the fluorosulfonate anion-containing compound, the oxalate anion-containing compound, or the sulfonylimide anion-containing compound, an insulating coating is more suitably formed on the surface of the positive electrode active material and / or the negative electrode active material, and gas generation during initial conditioning is further suppressed. These results show that by using the compound represented by general formula (A), the adsorption of the compounds contained in the electrolyte to the electrode can be controlled, and gas generation during initial conditioning can be suitably suppressed.

Claims

1. A non-aqueous electrolytic solution comprising an electrolyte, a non-aqueous solvent, a compound represented by the following general formula (A), and at least one compound selected from the group consisting of a compound represented by general formula (B), a compound represented by general formula (C), a compound represented by general formula (D), and a compound represented by general formula (E): the content of the compound represented by the general formula (A) is 0.001% by mass or more and 1% by mass or less with respect to the total amount of the nonaqueous electrolyte solution, The non-aqueous electrolyte solution is characterized in that the contents of the compound represented by general formula (B), the compound represented by general formula (C), the compound represented by general formula (D), and the compound represented by general formula (E) are 0.001% by mass or more and 3% by mass or less in 100% by mass of the non-aqueous electrolyte solution. 【Chemistry 1】 (In formula (A), R １ ~R ３ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R １ ~R ３ At least one of R is a hydrocarbon group having 1 to 12 carbon atoms. ４ ~R ５ R each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. ６ represents a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ４ or R ５ Either one of the two and R ６ may be bonded to each other to form a ring.) 【Chemistry 2】 (In formula (B), R 7 to R 12 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent; and n represents an integer of 1 to 5.) 【Transformation 3】 (In formula (C), R 13 and R 14 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and k represents an integer of 3 to 6.) 【Chemistry 4】 (In formula (D), R 15 to R 17 each independently represent a hydrocarbon group having 1 to 12 carbon atoms which may have a heteroatom, or a trialkylsilyl group. R 15 to R 17 may be bonded to each other to form a ring.) 【Transformation 5】 (In formula (E), R 21 and R 22 each independently represent an alkylene group having 1 to 10 carbon atoms which may have a substituent. m represents an integer of 0 or 1. When m is 0, the sulfur atom and the oxygen atom form a direct bond.)

2. The non-aqueous electrolyte solution according to claim 1, wherein the non-aqueous solvent is at least one selected from saturated cyclic carbonates, chain carbonates, carboxylic acid esters, ether-based compounds, and sulfone-based compounds.

3. 3. The nonaqueous electrolyte solution according to claim 1, further comprising at least one compound selected from the group consisting of a difluorophosphate anion-containing compound, a fluorosulfonate anion-containing compound, a sulfonylimide anion-containing compound, an alkylsulfate anion-containing compound, and an oxalate complex anion-containing compound.

4. The nonaqueous electrolyte solution according to any one of claims 1 to 3, further comprising at least one carbonate compound selected from the group consisting of unsaturated cyclic carbonates having a carbon-carbon unsaturated bond and cyclic carbonates having a fluorine atom.

5. The non-aqueous electrolyte solution according to claim 1, wherein the electrolyte is an alkali metal salt.

6. A non-aqueous electrolyte battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, A non-aqueous electrolyte battery, wherein the non-aqueous electrolyte is the non-aqueous electrolyte according to any one of claims 1 to 5.

7. 7. The nonaqueous electrolyte battery according to claim 6, wherein the positive electrode comprises a positive electrode active material, and the positive electrode active material is a transition metal oxide represented by the following composition formula (1): Li ａ１ Ni ｂ１ M ｃ１ O ２ (1) (In the above formula (1), a1, b1, and c1 represent numerical values ​​within the ranges 0.90≦a1≦1.10, 0.01≦b1≦0.98, and 0.01≦c1<0.50, and satisfy b1+c1=1. M represents at least one element selected from the group consisting of Mn, Co, Al, Mg, Zr, Fe, Ti, and Er.)

8. 8. The nonaqueous electrolyte battery according to claim 7, wherein the positive electrode comprises a positive electrode active material, and the positive electrode active material is a transition metal oxide represented by the following composition formula (2): Li ａ２ Ni ｂ２ Co ｃ２ M ｄ２ O ２ (2) (In the above formula (2), a2, b2, c2, and d2 represent numerical values ​​within the ranges 0.90≦a2≦1.10, 0.01≦b2≦0.98, 0.01≦c2<0.50, and 0.01≦d2<0.50, and satisfy b2+c2+d2=1. M represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er.)

9. 8. The nonaqueous electrolyte battery according to claim 7, wherein b1 in the formula (1) satisfies 0.40≦b1≦0.

98.

10. 9. The nonaqueous electrolyte battery according to claim 8, wherein b2 in the formula (2) satisfies 0.40≦b2≦0.

98.

11. The nonaqueous electrolyte battery according to any one of claims 6 to 10, wherein the negative electrode has a negative electrode active material and contains a material containing a metal element that can be alloyed with Li and / or a material containing a metalloid element that can be alloyed with Li.

12. 12. The nonaqueous electrolyte battery according to claim 11, wherein the material containing a metal element capable of forming an alloy with Li and / or the material containing a metalloid element capable of forming an alloy with Li is a material containing Si element.

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