JP2015046389A - Electrolytic solution for nonaqueous secondary batteries, and nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic solution for nonaqueous secondary batteries and a nonaqueous secondary battery which satisfy all of the requirements for high incombustibility, high-temperature durability and the ability to keep battery characteristics in discharge of large current at a low temperature.SOLUTION: An electrolytic solution for nonaqueous secondary batteries comprises: a nonaqueous solvent; an electrolyte; a compound described in the item (I) below; and a compound described in the item (II) below. (I) A compound expressed by the formula (1) below, and (II) at least one compound selected from the following compounds (2-1) to (2-3): (2-1) a compound expressed by a particular formula; (2-2) a compound having an alkyne structure; and (2-3) a cyclic ether compound (where Rto Reach represents a monovalent substituent group, of which at least one substituent group is -NRR, -N=Ror an azide group, and at least another substituent group is a halogen atom; and n represents an integer of 1 or larger).

Description

  The present invention relates to an electrolyte for a non-aqueous secondary battery containing a non-aqueous solvent and a non-aqueous secondary battery using the same.

  Lithium ion secondary batteries can achieve a large energy density in charge and discharge compared to lead batteries and nickel cadmium batteries. Utilizing this characteristic, application to portable electronic devices such as mobile phones and notebook personal computers is widespread. Accordingly, as a power source for portable electronic devices, development of a secondary battery that is particularly lightweight and capable of obtaining a high energy density is in progress. Furthermore, there is a strong demand for small size, light weight, long life, and reliability. High reliability is essential for applications such as electric vehicles and power storage equipment, which are expected to increase in capacity in the future, and there is a strong demand for both battery performance and reliability.

  As an electrolytic solution for a lithium ion secondary battery, a combination of a carbonate solvent such as propylene carbonate or diethyl carbonate and an electrolyte salt such as lithium hexafluorophosphate is widely used. This is because they have high conductivity and are stable in potential.

  On the other hand, since such a low molecular weight combustible organic compound is contained in the component, it is important to impart flame retardancy from the viewpoint of reliability. For the purpose of this improvement, a technique for including a phosphazene compound in an electrolytic solution has been proposed (see Patent Documents 1 to 3).

International Publication No. 2013/47342 Pamphlet JP 2012-94432 A Japanese Unexamined Patent Publication No. 2012-234771

  By the way, with the expansion of the application equipment of secondary batteries such as the above-mentioned electric vehicles, conventional mobile devices such as charging / discharging in high temperature outdoors, low temperature / high current discharge for start acceleration in midwinter as well as ensuring reliability Different performance is required. In view of such demands, the technology of the above-mentioned patent document is not yet sufficient, and it has been desired to achieve both high flame retardancy and battery performance that meets new requirements. Therefore, the present invention provides an electrolyte solution for a non-aqueous secondary battery and a non-aqueous secondary battery that simultaneously satisfy high flame retardancy, durability at high temperature, and maintenance of battery characteristics in large current discharge at low temperature. For the purpose of provision.

（式中、Ｒ^１〜Ｒ^６は１価の置換基を表す。これらの置換基の少なくとも１つは−ＮＲ^ＡＲ^Ｂ、−Ｎ＝Ｒ^Ｃ、又はアジ基であり、別の少なくとも１つはハロゲン原子である。ｎは１以上の整数を表す。Ｒ^Ａ及びＲ^Ｂはそれぞれ独立に水素原子、アルキル基、アルケニル基、アルキニル基、アリール基、ヘテロ環基、シアノ基、シリル基、または下記式（１Ａ）、（１Ｂ）、（１Ｃ）、もしくは（１Ｄ）で表される置換基である。Ｒ^Ｃは下記式（Ｃ１）〜（Ｃ６）のいずれかで表される置換基を表す。）

（式中、Ｒ^１Ａ１、Ｒ^１Ｃ１、Ｒ^１Ｄ１、Ｒ^１Ｄ２はアルキル基、アルコキシ基、アリール基、アリールオキシ基、ハロゲン原子、又はアミノ基を表す。Ｘ^Ａ１は酸素原子又は硫黄原子を表す。Ｘ^Ｄ１は酸素原子、硫黄原子、又は窒素原子を表し、Ｘ^Ｄ１が酸素原子、硫黄原子の場合、Ｒ^１Ｄ３は置換基ではない。Ｘ^Ｄ１が窒素原子の場合、Ｒ^１Ｄ３はアルキル基、アリール基、シリル基、又はホスホニル基を表す。Ｒ^１Ｂ１、Ｒ^１Ｂ２はアルキル基、アリール基、アルコキシカルボニル基、アリールオキシカルボニル基、アルキルスルホニル基、アリールスルホニル基、ホスホニル基、又はシリル基を表す。＊は結合手を表す。）

（式中、Ｒ^Ｘ１、Ｒ^Ｘ２、Ｒ^Ｘ３はアルキル基、アリール基、アルコキシ基、アリールオキシ基、アルキルチオ基、アリールチオ基、ヘテロ環基、ハロゲン原子、又はシリル基を表す。Ｒ^Ｙ１、Ｒ^Ｙ２はハロゲン原子を表す。＊は結合手を表す。）

（Ｒａ^１〜Ｒａ^３は独立に、アルキル基、アルコキシ基、アリールオキシ基、ハロゲン原子、アミノ基、または−（ＣＨ_２）_ｎＣ（＝Ｏ）−（Ｏ）_ｍＲｂ^４（ｎは０または１、ｍは０または１、Ｒｂ^４はアルキル基、アルケニル基、アリール基、またはアラルキル基である）である。Ｘは酸素原子、硫黄原子、Ｎ（Ｒａ^１２）を表す。Ｒａ^１２は水素原子または１価の置換基を表す。）
〔２〕上記化合物（２−２）が下記式（２−２ａ）〜（２−２ｇ）のいずれかの化合物である〔１〕に記載の非水二次電池用電解液。

Ｒｃ^１〜Ｒｃ^１４は水素原子、１価の基を表す。Ｒｃ^１およびＲｃ^２、Ｒｃ^３およびＲｃ^４、Ｒｃ^５およびＲｃ^６、Ｒｃ^７およびＲｃ^８、Ｒｃ^９およびＲｃ^１０、Ｒｃ^１１およびＲｃ^１２、Ｒｃ^１３およびＲｃ^１４のそれぞれのうち少なくとも一方はアルキン構造を有している。Ｌｃは炭化水素連結基を表す。
〔３〕上記化合物（２−２ａ）〜（２−２ｇ）のいずれかで表される化合物のアルキン構造が下記（Ａ１）の構造で表される〔２〕に記載の非水二次電池用電解液。

Ｌ^１は単結合または、炭化水素連結基、ヘテロ連結基、またはこれらを組み合せた連結基を表す。Ｌ^２は炭化水素連結基、ヘテロ連結基、またはこれらを組み合せた連結基を表す。ｎｌは０〜１０の整数である。Ｒ^２１はアルキル基、アリール基、アラルキル基、アミノ基、シリル基、または水素原子を表す。
〔４〕上記化合物（２−３）が環内に１又は２つの酸素原子を有する５又は６員環エーテル化合物である〔１〕に記載の非水二次電池用電解液。
〔５〕上記化合物（２−３）が下記式（Ｂ１）〜（Ｂ５）のいずれかの化合物である〔４〕に記載の非水二次電池用電解液。

Ｒ^３１〜Ｒ^３６はそれぞれ独立に置換基を表す。ｎ１は０〜８の整数を表す。ｎ２は０〜６の整数を表す。ｎ３は０〜１０の整数を表す。ｎ４は０〜８の整数を表す。ｎ５、ｎ６は０〜５の整数を表す。
〔６〕上記化合物（Ｉ）を電解液全量中０．１〜２０質量％で含有する〔１〕〜〔５〕のいずれか１つに記載の非水二次電池用電解液。
〔７〕上記化合物（ＩＩ）を電解液全量中０．０１〜１０質量％で含有する〔１〕〜〔５〕のいずれか１つに記載の非水二次電池用電解液。
〔８〕上記式（１）において、Ｒ^１〜Ｒ^６のすべてがハロゲン原子と、上記特定含窒素基とで構成されている〔１〕〜〔７〕のいずれか１つに記載の非水二次電池用電解液。
〔９〕上記化合物（Ｉ）１００質量部に対して上記化合物（ＩＩ）を１０〜１００質量部で用いる〔１〕〜〔８〕のいずれか１つに記載の非水二次電池用電解液。
〔１０〕〔１〕〜〔９〕のいずれか１つに記載の非水二次電池用電解液と、正極と、負極とを有する非水二次電池。
〔１１〕上記正極の活物質がニッケルおよび／またはマンガンを含有する材料からなる〔１０〕に記載の非水二次電池。
〔１２〕上記負極の活物質が炭素、ケイ素、チタン、およびスズから選ばれる少なくとも１種を含有する材料からなる〔１０〕または〔１１〕に記載の非水二次電池。 The above problem has been solved by the following means.
[1] An electrolyte solution for a non-aqueous secondary battery containing a non-aqueous solvent, an electrolyte, a compound of the following (I), and a compound of the following (II).
(I) Compound represented by the following formula (1) (II) At least one compound selected from the following (2-1) to (2-3) (2-1) represented by the following formula (2-1) (2-2) Compound having alkyne structure (2-3) Cyclic ether compound

(In the formula, R ^{1 to} R ⁶ each represent a monovalent substituent. At least one of these substituents is —NR ^A R ^B , —N═R ^C , or an azide group, and at least one of the other substituents. Is a halogen atom, n represents an integer of 1 or more, and R ^A and R ^B are each independently a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, silyl group, or A substituent represented by the following formula (1A), (1B), (1C), or (1D) R ^C represents a substituent represented by any of the following formulas (C1) to (C6). .)

(In the formula, R ^1A1 , R ^1C1 , R ^1D1 and R ^1D2 represent an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a halogen atom, or an amino group. X ^A1 represents an oxygen atom or a sulfur atom. X ^D1 represents an oxygen atom, a sulfur atom, or a nitrogen ^{atom, X D1} is an oxygen atom, a sulfur ^{atom, R 1D3} is not a substituent ^{.X D1} is a nitrogen ^{atom, R 1D3} is an alkyl group, an aryl group, R ^1B1 and R ^{1B2 each} represents an alkyl group, an aryl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a phosphonyl group, or a silyl group, and * represents a bond. Represents hand.)

(Wherein R ^X1 , R ^X2 and R ^X3 represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a heterocyclic group, a halogen atom, or a silyl group. R ^Y1 and R ^Y2 Represents a halogen atom, and * represents a bond.)

(Ra ^{1 to} Ra ³ are independently an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, or — (CH ₂ ) _n C (═O) — (O) _m Rb ⁴ (n is 0 or 1, m represents 0 or 1, and Rb ⁴ represents an alkyl group, an alkenyl group, an aryl group, or an aralkyl group, and X represents an oxygen atom, a sulfur atom, or N (Ra ¹² ), and Ra ¹² represents a hydrogen atom. Or represents a monovalent substituent.)
[2] The electrolyte solution for a nonaqueous secondary battery according to [1], wherein the compound (2-2) is any one of the following formulas (2-2a) to (2-2g).

Rc ^{1 to} Rc ¹⁴ represent a hydrogen atom or a monovalent group. At least ^one of Rc ¹ and Rc ² , Rc ³ and Rc ⁴ , Rc ⁵ and Rc ⁶ , Rc ⁷ and Rc ⁸ , Rc ⁹ and Rc ¹⁰ , Rc ¹¹ and Rc ¹² , Rc ¹³ and Rc ¹⁴ is an alkyne structure have. Lc represents a hydrocarbon linking group.
[3] The non-aqueous secondary battery according to [2], wherein the alkyne structure of the compound represented by any one of the compounds (2-2a) to (2-2g) is represented by the following structure (A1): Electrolytic solution.

L ¹ represents a single bond, a hydrocarbon linking group, a hetero linking group, or a linking group obtained by combining these. L ² represents a hydrocarbon linking group, a hetero linking group, or a linking group obtained by combining these. nl is an integer of 0-10. R ²¹ represents an alkyl group, an aryl group, an aralkyl group, an amino group, a silyl group, or a hydrogen atom.
[4] The electrolyte solution for a nonaqueous secondary battery according to [1], wherein the compound (2-3) is a 5- or 6-membered cyclic ether compound having 1 or 2 oxygen atoms in the ring.
[5] The electrolyte solution for a non-aqueous secondary battery according to [4], wherein the compound (2-3) is any one of the following formulas (B1) to (B5).

R ^{31 to} R ³⁶ each independently represents a substituent. n1 represents the integer of 0-8. n2 represents an integer of 0 to 6. n3 represents an integer of 0 to 10. n4 represents an integer of 0 to 8. n5 and n6 represent an integer of 0 to 5.
[6] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [5], containing the compound (I) in an amount of 0.1 to 20% by mass in the total amount of the electrolyte solution.
[7] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [5], containing the compound (II) in an amount of 0.01 to 10% by mass in the total amount of the electrolyte solution.
[8] The non-aqueous solution according to any one of [1] to [7], wherein in the formula (1), all of R ^{1 to} R ⁶ are composed of a halogen atom and the specific nitrogen-containing group. Secondary battery electrolyte.
[9] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [8], wherein the compound (II) is used in an amount of 10 to 100 parts by mass with respect to 100 parts by mass of the compound (I). .
[10] A nonaqueous secondary battery comprising the electrolyte for a nonaqueous secondary battery according to any one of [1] to [9], a positive electrode, and a negative electrode.
[11] The nonaqueous secondary battery according to [10], wherein the positive electrode active material is made of a material containing nickel and / or manganese.
[12] The nonaqueous secondary battery according to [10] or [11], wherein the negative electrode active material is made of a material containing at least one selected from carbon, silicon, titanium, and tin.

  In this specification, when there are a plurality of substituents or linking groups indicated by a specific symbol, or when a plurality of substituents etc. (same definition of the number of substituents) are specified simultaneously or alternatively, The substituents and the like may be the same as or different from each other. Further, when a plurality of substituents and the like are close to each other, they may be bonded to each other or condensed to form a ring. At this time, the hetero linking group described later may be incorporated in the ring.

  The nonaqueous electrolytic solution of the present invention can exhibit high flame retardancy while realizing durability under high temperature conditions in a secondary battery equipped with the same, and suppressing capacity deterioration in low temperature / large current discharge. Excellent effects such as. Furthermore, if necessary, the battery is adapted to a battery using a positive electrode material that can be used up to a high potential containing Ni and / or Mn, and exhibits the above-described excellent performance.

It is sectional drawing which shows typically the mechanism of the lithium secondary battery which concerns on preferable embodiment of this invention. It is sectional drawing which shows the specific structure of the lithium secondary battery which concerns on preferable embodiment of this invention.

The nonaqueous electrolytic solution of the present invention contains a nonaqueous solvent, an electrolyte, the following compound (I), and the following compound (II).
(I) Compound represented by the following formula (1) (II) At least one compound selected from the following (2-1) to (2-3) (2-1) represented by the following formula (2-1) (2-2) Compound having alkyne structure (2-3) Cyclic ether compound

[Compound represented by Formula (1)]

・ R ^{1 to} R ⁶
In the formula, R ^{1 to} R ⁶ represent a monovalent substituent. At least one of the substituents of R ^{1 to} R ⁶ is —NR ^A R ^B , —N═R ^C , or an azide group, and at least one other is a halogen atom. Among them, all of R ^{1 to} R ⁶ are a group selected from —NR ^A R ^B , —N═R ^C , and an azide group or a combination thereof (hereinafter, this may be referred to as “specific nitrogen-containing group”). , And preferably in combination with a halogen atom. As the halogen atom, fluorine is preferred. The number of the specific nitrogen-containing groups is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, particularly preferably 1 to 2, and still more preferably 1. . As a substitution position, it is preferable that one specific nitrogen-containing group is substituted on one phosphorus atom.

R ^{1 to} R ⁶ may be bonded to each other to form a ring containing a phosphorus atom. R ^{1 to} R ⁶ may be different from each other or the same. In particular, when a ring is formed, it is preferable that R ¹ and R ² , R ³ and R ⁴ , or R ⁵ and R ⁶ form a ring.

The substituents R ^{1 to} R ⁶ are preferably an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, the specific nitrogen-containing group, and a halogen atom. Particularly preferably, the alkyl group having 1 to 6 carbon atoms, the aryl group having 6 to 12 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, the aryloxy group having 6 to 12 carbon atoms, the alkylthio group having 1 to 6 carbon atoms, An arylthio group having 6 to 12 carbon atoms, a halogen atom (preferably chlorine or fluorine), and the specific nitrogen-containing group, and particularly preferably the specific nitrogen-containing group, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, or It is a C1-C6 alkoxy group. The alkyl group and aryl group may be substituted. The alkyl group may be linear or branched.

・ N
n represents an integer of 1 or more, preferably 1 to 3, more preferably 1 to 2, and still more preferably 1.

・ R ^A , R ^B
R ^A and R ^B are a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a heterocyclic group, a cyano group, a silyl group, or the following formula (1A), (1B), (1C), or (1D) It is a substituent represented by these.

Among R ^A and R ^B , an alkyl group, an aryl group, a substituent represented by Formula (1A) or Formula (1D) is preferable, and an alkyl group having 1 to 8 carbon atoms, particularly preferably 1 to 1 carbon atoms is preferable. A fluorine-substituted alkyl group having 6 carbon atoms, an alkyl group having an ether group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and a substituent represented by the formula (1A) having 1 to 7 carbon atoms. More preferably, it is a C1-C4 alkyl group and a C1-C4 fluorine-substituted alkyl group, and among them, a substituent having a total carbon number of 6 or less. The total number of carbon atoms is particularly preferably 4 or less. R ^A and R ^B may be bonded to each other or condensed to form a ring containing a nitrogen atom. The alkyl group may be linear or branched. R ^A and R ^B may be the same as or different from each other. When forming a ring with R ^A and R ^B , an aziridine ring, azetidine ring, pyrrolidine ring, pyrroline ring, piperazine ring, morpholine ring, thiomorpholine ring, oxazolidine ring, thiazolidine ring, imidazoline ring, (iso) indole ring, A carbazole ring is preferred.

・ R ^1A1 , R ^1C1 , R ^1D1 , R ^1D2
In the formula, R ^1A1 , R ^1C1 , R ^1D1 , and R ^{1D2 each} represents an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a halogen atom, or an amino group. Preferred examples of these substituents include the following examples. That is, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, a chlorine group, and a fluorine atom are preferable. -6 alkyl groups, C1-C6 alkoxy groups, chlorine groups and fluorine atoms are more preferred. These substituents may be further substituted. * Represents a bond.

・ R ^1B1 , R ^1B2
R ^1B1 and R ^1B2 are a hydrogen atom, an alkyl group, an aryl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a silyl group, or a phosphonyl group (—P (═O) (OR ^N ) _2. ) ( ^RN is as defined below). Preferred examples of these substituents include the following examples. That is, an alkyl group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 1 to 7 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aryloxycarbonyl group having 7 to 12 carbon atoms, and an alkylsulfonyl group having 1 to 6 carbon atoms An arylsulfonyl group having 6 to 12 carbon atoms, a silyl group having 1 to 6 carbon atoms, and a phosphonyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 1 to 7 carbon atoms, Particularly preferred are an alkylsulfonyl group having 1 to 6 carbon atoms, a silyl group having 1 to 6 carbon atoms, and a phosphonyl group having 1 to 12 carbon atoms.

・ X ^A1 , X ^D1 , R ^1D3
In the formula, X ^A1 represents an oxygen atom or a sulfur atom.
X ^D1 represents an oxygen atom, a sulfur atom, or a nitrogen atom. When X ^D1 is an oxygen atom or a sulfur atom, R ^1D3 is not a substituent. When X ^D1 is a nitrogen atom, R ^1D3 is an alkyl group (preferably having 1 to 4 carbon atoms), an aryl group (preferably having 6 to 12 carbon atoms), a silyl group (preferably having 1 to 6 carbon atoms), or a phosphonyl group. (Preferably having 1 to 12 carbon atoms).

・ R ^c
R ^c represents a substituent represented by any one of formulas (C1) to (C6).

R ^X1 , R ^X2 and R ^X3 are alkyl groups (preferably having 1 to 6 carbon atoms), aryl groups (preferably having 6 to 24 carbon atoms), alkoxy groups (preferably having 1 to 6 carbon atoms), aryloxy groups (preferably Has 6 to 24 carbon atoms, an alkylthio group (preferably 1 to 6 carbon atoms), an arylthio group (preferably 6 to 24 carbon atoms), a heterocyclic group (preferably 1 to 12 carbon atoms), a halogen atom, or silyl Represents a group (preferably having 1 to 6 carbon atoms).
R ^Y1 and R ^Y2 represent a halogen atom. Preferably, R ^X1 , R ^X2 and R ^X3 are each an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, a chlorine atom, a fluorine atom, or 1 to 6 carbon atoms. The silyl group of

In the present invention, in the formula (1), all of R ^{1 to} R ⁶ are composed of a halogen atom (preferably a fluorine atom) and the specific nitrogen-containing group (more preferably —NR ^A R ^B ). It is preferred that 1 to 3 of these are the specific nitrogen-containing groups, more preferably the specific nitrogen-containing group is 1 or 2, and even more preferably when the specific nitrogen-containing group is 1. is there.

  Specific examples of the compound represented by formula (1) are shown below, but the present invention is not construed as being limited thereto.

The compound represented by the above formula (1) can be synthesized by a conventional method, but for example, the method described in German Patent Publication No. 2139691 can be referred to.
Further, after introducing the same amino group as the target product into hexachlorocyclotriphosphazene, the target product can also be obtained by fluorination with a fluorinating agent such as sodium fluorinated, potassium fluorinated, or antimony fluorinated. . The amination of chlorocyclotriphosphazene and fluorocyclotriphosphazene in the above method can be used as an acid remover that produces the same amine as the target product, but the same amine, inorganic base and organic as the target product. It can be similarly synthesized by coexisting bases. The inorganic base is preferably an inorganic base composed of an anion and a metal cation, particularly preferably an anion as a hydroxide, carbonate, bicarbonate, or fluoride, and a metal cation as an alkali metal, A combination selected from alkaline earth metals is preferred. The metal cation is preferably selected from sodium, potassium, magnesium, and calcium. Preferable examples include hydroxides such as sodium hydroxide and potassium hydroxide, carbonates such as potassium carbonate, sodium carbonate and sodium hydrogen carbonate, fluorides such as sodium fluorinated and potassium fluorinated, and triethylamine as the organic base. Examples thereof include trialkylamines such as diisopropylethylamine, methylmorpholine and diazabicycloundecene, and aromatic bases such as pyridine and lutidine. The solvent used at the time of synthesis is a commonly used solvent and can be used without any problem. Preferred examples include ester solvents, ether solvents, nitrile solvents, aliphatic solvents, and organic solvent-water two-layer solvents. . Specifically, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as diethyl ether, tert-butyl methyl ether and cyclopentyl methyl ether, nitrile solvents such as acetonitrile, and aliphatic solvents such as hexane and decane. , Two-layer solvents such as toluene-water, ethyl acetate-water, and the like. Among these, ether solvents and nitrile solvents are preferable.
In addition to the above method, an amine-metal bond can be formed and synthesized by reacting it with chlorocyclotriphosphazene or fluorocyclotriphosphazene. Examples of amine-metal bonds include bonds with alkali metals such as amine-lithium and amine-sodium bonds, bonds with alkaline earth metals such as amine-calcium bonds, and bonds with silicon such as amine-trimethylsilyl bonds.

  The concentration of the compound represented by the formula (1) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1% by mass or more with respect to the total electrolyte solution (including the electrolyte). . The upper limit is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

Ｒａ^１〜Ｒａ^３は独立に、アルキル基（炭素数１〜１２が好ましく、１〜６がより好ましく、１〜４が特に好ましい）、アルコキシ基（炭素数１〜１２が好ましく、１〜８がより好ましく、１〜３が特に好ましい）、アリールオキシ基（炭素数６〜２２が好ましく、６〜１４がより好ましく、６〜１０が特に好ましい）、ハロゲン原子、アミノ基（炭素数０〜６が好ましく、０〜３がより好ましい）、または−（ＣＨ_２）_ｎＣ（＝Ｏ）−（Ｏ）_ｍＲｂ^４である。ｎは０または１、ｍは０または１である。Ｒｂ^４はアルキル基（炭素数１〜１２が好ましく、１〜６がより好ましく、１〜４が特に好ましい）、アルケニル基（炭素数２〜１２が好ましく、２〜４がより好ましい）、アリール基（炭素数６〜２２が好ましく、６〜１４がより好ましく、６〜１０が特に好ましい）、またはアラルキル基（炭素数７〜２３が好ましく、７〜１５がより好ましく、７〜１１が特に好ましい）である。
Ｘは酸素原子、硫黄原子、Ｎ（Ｒａ^１２）を表す。Ｒａ^１２は水素原子または１価の置換基を表す。
Ｒａ^１〜Ｒａ^３におけるアルキル基としては炭素数１〜４が好ましく、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基などが挙げられる。
アルコキシ基としては炭素数１〜８が好ましく、メトキシ基、エトキシ基、ブトキシ基などの無置換アルコキシ基、２、２、２−トリフロロエトキシ基、１，１，１，３，３，３−ヘキサフロロイソプロポキシ基、パーフロロブチルエチル基などのフッ素置換されたアルコキシ基が挙げられ、メトキシ基、２、２、２−トリフロロエトキシ基、１，１，１，３，３，３−ヘキサフロロイソプロポキシ基が好ましい。Ｒａ^１〜Ｒａ^３は、炭素数７〜２０のアラルキルオキシ基（−Ｏ−Ａｌｋ−Ａｒ：Ａｌｋは炭素数１〜６のアルキレン基、Ａｒが炭素数６〜１４のアリール基）であることも好ましい。
アリールオキシ基としてはフェノキシ基、フッ素置換されたフェノキシ基が好ましい。
ハロゲン原子としては塩素原子、フッ素原子が好ましく、フッ素原子がより好ましい。
アミノ基としてはジアルキルアミノ基が好ましく、ジメチルアミノ基、ジエチルアミノ基、ジブチルアミノ基など総炭素数２〜８のジアルキルアミノ基が好ましい。
−（ＣＨ_２）_ｎＣ（＝Ｏ）−（Ｏ）_ｍＲｂ^４におけるＲｂ^４としてはメチル基、エチル基が好ましい。
Ｒａ^１２における１価の置換基として好ましくはアルキル基（炭素数１〜６が好ましい）、−Ｓ（＝Ｏ）_２Ｒａ^１３（Ｒａ^１３はアルキル基（炭素数１〜６が好ましい）、アリール基（炭素数６〜１４が好ましい）、アラルキル基（炭素数７〜１５が好ましい）、アルケニル基（炭素数１〜６が好ましい））、−Ｐ（＝Ｏ）（Ｒａ^１４）_２（Ｒａ^１４はアルコキシ基（炭素数１〜６が好ましい）、アリールオキシ基（炭素数６〜１４が好ましい）、アルキル基（炭素数１〜６が好ましい）、アリール基（炭素数６〜１４が好ましい）、ハロゲン原子）を挙げることができる。
Ｒａ^１〜Ｒａ^３、Ｒａ^１２はさらに置換基Ｔを有していてもよく、中でも、ハロゲン原子（フッ素原子）、シアノ基等が挙げられる。 [Compound defined by (2-1): Compound represented by formula (2-1)]

Ra ^{1 to} Ra ³ are independently an alkyl group (preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms), an alkoxy group (preferably 1 to 12 carbon atoms and 1 to 8 carbon atoms). More preferably, 1 to 3 is particularly preferable, an aryloxy group (preferably 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms, particularly preferably 6 to 10 carbon atoms), a halogen atom, an amino group (having 0 to 6 carbon atoms). 0 to 3 are more preferable), or — (CH ₂ ) _n C (═O) — (O) _m Rb ⁴ . n is 0 or 1, and m is 0 or 1. Rb ⁴ is an alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms), an alkenyl group (preferably having 2 to 12 carbon atoms, more preferably 2 to 4 carbon atoms), an aryl group. (C6-C22 is preferable, 6-14 is more preferable, and 6-10 are especially preferable), or an aralkyl group (C7-23 is preferable, 7-15 is more preferable, and 7-11 are especially preferable). It is.
X represents an oxygen atom, a sulfur atom, or N (Ra ¹² ). Ra ¹² represents a hydrogen atom or a monovalent substituent.
The alkyl group in Ra ^{1 to} Ra ³ preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group.
The alkoxy group preferably has 1 to 8 carbon atoms, and is an unsubstituted alkoxy group such as a methoxy group, an ethoxy group, or a butoxy group, 2,2,2-trifluoroethoxy group, 1,1,1,3,3,3- Examples include fluorine-substituted alkoxy groups such as hexafluoroisopropoxy group and perfluorobutylethyl group, methoxy group, 2,2,2-trifluoroethoxy group, 1,1,1,3,3,3-hexa A fluoroisopropoxy group is preferred. Ra ^{1 to} Ra ³ may be an aralkyloxy group having 7 to 20 carbon atoms (-O-Alk-Ar: Alk is an alkylene group having 1 to 6 carbon atoms, Ar is an aryl group having 6 to 14 carbon atoms). preferable.
The aryloxy group is preferably a phenoxy group or a fluorine-substituted phenoxy group.
As a halogen atom, a chlorine atom and a fluorine atom are preferable, and a fluorine atom is more preferable.
The amino group is preferably a dialkylamino group, and a dialkylamino group having 2 to 8 carbon atoms in total, such as a dimethylamino group, a diethylamino group, or a dibutylamino group.
_{- (CH 2) n C (} = O) - (O) m Rb methyl group as Rb ⁴ of ⁴ and an ethyl group are preferable.
The monovalent substituent in Ra ¹² is preferably an alkyl group (preferably having 1 to 6 carbon atoms), -S (= O) ₂ Ra ¹³ (Ra ¹³ is an alkyl group (preferably having 1 to 6 carbon atoms), or an aryl group. (Preferably 6 to 14 carbon atoms), aralkyl group (preferably 7 to 15 carbon atoms), alkenyl group (preferably 1 to 6 carbon atoms), -P (= O) (Ra ¹⁴ ) ₂ (Ra ¹⁴ is Alkoxy group (preferably having 1 to 6 carbon atoms), aryloxy group (preferably having 6 to 14 carbon atoms), alkyl group (preferably having 1 to 6 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), halogen Atom).
Ra ^{1 to} Ra ³ and Ra ¹² may further have a substituent T, and among them, a halogen atom (fluorine atom), a cyano group and the like can be mentioned.

Preferred specific examples of the compound represented by the formula (2-1) are shown below (Me is a methyl group and Ph is a phenyl group). However, the present invention is not construed as being limited by this illustration.

  The concentration of the compound represented by the formula (2-1) is preferably 0.01% by mass or more, and more preferably 0.5% by mass or more with respect to the total electrolytic solution. The upper limit is preferably 10% by mass or less, and more preferably 7% by mass or less.

[Compound defined by (2-2): Compound having alkyne structure]
The compound having an alkyne structure is not particularly limited, but has an alkyne bond (carbon-carbon triple bond) in the molecule. Further -C in the molecule (= O) O-bond, -O-C (= O) O- bond, -S (= _O) 2 O- _{bond, -O-S (= O)} 2 O- bond, It preferably has an aromatic ring structure. It is preferable that 1 to 3 alkyne structures are contained in the molecule.

  The compound having an alkyne structure is more preferably a compound represented by any one of the following formulas (2-2a) to (2-2g).

Rc ^{1 to} Rc ¹⁴ represent a hydrogen atom or a monovalent group. At least one of Rc ¹ and Rc ² has an alkyne structure (carbon-carbon triple bond). At least one of Rc ³ and Rc ⁴ has an alkyne structure. At least one of Rc ⁵ and Rc ⁶ has an alkyne structure. At least one of Rc ⁷ and Rc ⁸ has an alkyne structure. At least one of Rc ⁹ and Rc ¹⁰ has an alkyne structure. At least one of Rc ¹¹ and Rc ¹² has an alkyne structure. At least one of Rc ¹³ and Rc ¹⁴ has an alkyne structure.
Lc represents a hydrocarbon linking group described later, and is preferably an alkylene group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 and particularly preferably 1 to 3).
When Rc ^{1 to} Rc ¹⁴ are a monovalent group, examples of the substituent T described below are given except for a group having an alkyne structure. Among them, as an arbitrary monovalent group of Rc ^{1 to} Rc ¹⁰ , an alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), an alkenyl group (having 2 to 2 carbon atoms). 12 is preferable, and 2 to 6 are more preferable), an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14 and particularly preferably 6 to 10), and an aralkyl group (preferably having 7 to 23 carbon atoms and 7 To 15 are more preferable, and 7 to 11 are particularly preferable), and a silyl group (C1-C12 is preferable, 1 to 6 is more preferable, and 1-3 is particularly preferable) is preferable. These groups may further have a substituent T described later, and examples of the further substituent include a halogen atom (fluorine atom) and a cyano group.

  Examples of the group having an alkyne structure include the following structure (A1).

L ¹ is synonymous with a single bond or a linking group L (a hydrocarbon linking group, a hetero linking group, or a linking group obtained by combining these), and an alkylene group (preferably having 1 to 12 carbon atoms and having 1 to 6 carbon atoms). More preferably, 1 to 3 is particularly preferable, an alkenylene group (having preferably 2 to 12 carbon atoms, more preferably 2 to 6), or a single bond.
L ² has the same meaning as the linking group L (a hydrocarbon linking group, a hetero linking group, or a linking group obtained by combining these), and is preferably a hetero linking group. Of these, a linking group having 1 to 4 linking atoms composed of a combination of a carbonyl group and an oxy group is preferable.
nl is an integer of 0 to 10, preferably 0 to 4, more preferably 0 to 2, and particularly preferably 1.
Examples of the substituent T include R ²¹ , an alkyl group (preferably having 1 to 12 carbons, more preferably 1 to 6 and particularly preferably 1 to 3), an aryl group (preferably having 6 to 22 carbons, 6 To 14 are more preferable, and 6 to 10 are particularly preferable), an aralkyl group (preferably having 7 to 23 carbon atoms, more preferably 7 to 15 and particularly preferably 7 to 11), and an amino group (preferably having 0 to 6 carbon atoms). 0-3 are more preferable), a silyl group (C1-C12 is preferable, 1-6 are more preferable, and 1-3 are especially preferable), or a hydrogen atom is preferable.

  The compound having an alkyne structure may have two or more structures of 2-2a to 2-2g in one molecule.

Adjacent ones of Rc ^{1 to} Rc ¹⁴ may be bonded to each other to form a ring structure.
When there are a plurality of Rc ^{1 to} Rc ¹⁰ in one molecule, they may be different from each other.
The above ring may interpose a hetero linking group described later.

Preferred specific examples of the compound defined by (2-2) are shown below. However, the present invention is not construed as being limited by this illustration.

  The concentration of the compound having an alkyne structure is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.2% by mass or more with respect to the total electrolyte solution. The upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less.

[Compound defined by (2-3): cyclic ether compound]
As the cyclic ether compound, a 5- or 6-membered ring ether compound is preferable, and a compound having 1 or 2 oxygen atoms in the ring is preferable.
The cyclic ether compound is preferably represented by any of the following formulas (B1) to (B5).

R ^{31 to} R ³⁶ are each independently an arbitrary substituent T, and among them, an alkyl group, an alkenyl group, and an aryl group are preferable. These groups may be substituted via a hetero linking group described later, and a hetero linking group may be interposed in the substituent. As the substituent, the following (A2) is preferable.

* -L ^1- (O) _na- (CO) _nb- (O) _nc -R ³⁷ (A2)

L ¹ is synonymous with the formula (A1). na and nc are 0 or 1. nb is an integer of 0-2. na + nb + nc is 1 or more. Examples of R ³⁷ include a hydrogen atom or an arbitrary substituent T, and examples thereof include a group having the structure of the cyclic ether (B1) to (B5), an alkyl group, and a heterocyclic group (tetrahydrofuran, tetrahydropyran, etc.).
Two or more adjacent R ^{31 to} R ³⁶ may be bonded or condensed to form a ring. At this time, a hetero linking group described later may be incorporated. n1 represents the integer of 0-8. n2 represents an integer of 0 to 6. n3 represents an integer of 0 to 10. n4 represents an integer of 0 to 8. n5 and n6 represent an integer of 0 to 5. Formulas (B1) to (B5) may each be a dimer structure linked to each other.
Preferred are aliphatic cyclic ether compounds such as tetrahydrofuran, tetrahydropyran, 1,4-dioxane, 1,3-dioxolane, or derivatives thereof, and cyclic ether compounds in which an aromatic ring such as benzofuran or dibenzofuran is substituted or condensed.
Two or more cyclic ether structures may be bonded via a single bond or a linking group L described later.

Preferred specific examples of the compound defined by (2-3) are shown below. However, the present invention is not construed as being limited by this illustration.

The concentration of the cyclic ether compound is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.5% by mass or more with respect to the total electrolytic solution. The upper limit is preferably 10% by mass or less, more preferably 7% by mass or less, and particularly preferably 5% by mass or less.
When compound (II) (compound defined by any one of (2-1) to (2-3)) is defined comprehensively, its concentration is preferably 0.01% by mass or more, more preferably 0.1%. It is at least 0.5% by mass, more preferably at least 0.5% by mass. The upper limit is preferably 10% by mass or less, more preferably 7% by mass or less, and particularly preferably 5% by mass or less.

  In terms of the relationship between the compounds (I) and (II), the compound (II) is preferably used in an amount of 1 part by mass or more with respect to 100 parts by mass of the compound (I). More preferably, it is 10 parts by mass or more. As an upper limit, it is preferable that it is 200 mass parts or less, It is more preferable that it is 150 mass parts or less, It is especially preferable that it is 100 mass parts or less. It is considered that the compound (II) has a function of suppressing the influence on the battery performance while maintaining the effect of improving the flame retardancy of the compound (I). This is presumably because the decomposition product of the compound (II) formed a specific film on the positive electrode, thereby suppressing the decomposition of the compound (I) and the resulting deterioration of the positive electrode. From that point of view, as described above, the compound (II) does not need to be excessive with respect to the compounding amount of the compound (I), and a desired effect can be obtained by applying an equal amount or a small amount. .

(Electrolytes)
The electrolyte used in the electrolytic solution of the present invention is preferably a salt of a metal ion belonging to Group 1 or Group 2 of the Periodic Table. The material is appropriately selected depending on the intended use of the electrolytic solution. For example, lithium salt, potassium salt, sodium salt, calcium salt, magnesium salt and the like can be mentioned. When used in a secondary battery or the like, lithium salt is preferable from the viewpoint of output. When the electrolytic solution of the present invention is used as a non-aqueous electrolytic solution for a lithium secondary battery, a lithium salt may be selected as a metal ion salt. As a lithium salt, the lithium salt normally used for the electrolyte of the nonaqueous electrolyte solution for lithium secondary batteries is preferable, For example, what is described below is preferable.

(L-1) Inorganic lithium salts: inorganic fluoride salts such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ ; perhalogenates such as LiClO ₄ , LiBrO ₄ , LiIO ₄ ; inorganic chloride salts such as LiAlCl ₄ etc.

(L-2) Fluorine-containing organic lithium salt: Perfluoroalkane sulfonate such as LiCF ₃ SO ₃ ; LiN (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , Perfluoroalkanesulfonylimide salts such as LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ); perfluoroalkanesulfonylmethide salts such as LiC (CF ₃ SO ₂ ) ₃ ; Li [PF ₅ (CF ₂ CF ₂ CF ₃ )], Li [PF ₄ (CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF ₃ ) ₃ ], Li [PF ₅ (CF ₂ CF ₂ CF ₂ CF _{3 )], Li [PF 4 (} CF 2 CF 2 CF 2 CF 3) 2], Li [PF 3 (CF 2 CF 2 CF 2 CF 3) 3] fluoroalkyl fluoride such as potash Acid salts, and the like.

(L-3) Oxalatoborate salt: lithium bis (oxalato) borate, lithium difluorooxalatoborate and the like.
Among these, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiClO ₄ , Li (Rf ¹ SO ₃ ), LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ), preferably LiPF ₆ , LiBF ₄ , LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ) More preferred are imide salts. Here, Rf ¹ and Rf ² each represent a perfluoroalkyl group.
In addition, the electrolyte used for electrolyte solution may be used individually by 1 type, or may combine 2 or more types arbitrarily.
The electrolyte in the electrolytic solution (preferably a metal ion belonging to Group 1 or Group 2 of the periodic table or a metal salt thereof) is added in an amount so as to obtain a preferable salt concentration described in the method for preparing the electrolytic solution below. It is preferable. The salt concentration is appropriately selected depending on the purpose of use of the electrolytic solution, but is generally 10% by mass to 50% by mass, more preferably 15% by mass to 30% by mass, based on the total mass of the electrolytic solution. The molar concentration is preferably 0.5M to 1.5M. In addition, when evaluating as an ion density | concentration, what is necessary is just to calculate by salt conversion with the metal applied suitably.

(Non-aqueous solvent)
The non-aqueous solvent used in the present invention is preferably an aprotic organic solvent, and more preferably an aprotic organic solvent having 2 to 10 carbon atoms. The non-aqueous solvent is preferably a compound having an ether group, a carbonyl group, an ester group, or a carbonate group. The said compound may have a substituent and the postscript substituent T is mentioned as the example.

Examples of the non-aqueous solvent include ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, γ-butyrolactone, γ-valerolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2 -Methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, 1,4-dioxane, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, butyric acid Methyl, methyl isobutyrate, methyl trimethylacetate, ethyl trimethylacetate, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropionitrile, N, Examples thereof include N-dimethylformamide, N-methylpyrrolidinone, N-methyloxazolidinone, N, N′-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, dimethyl sulfoxide, and dimethyl sulfoxide phosphoric acid. These may be used alone or in combination of two or more. Among these, at least one member selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, and γ-butyrolactone is preferable. Particularly, a high viscosity (high dielectric constant) solvent such as ethylene carbonate or propylene carbonate. A combination of (for example, relative dielectric constant ε ≧ 30) and a low viscosity solvent (for example, viscosity ≦ 1 mPa · s) such as dimethyl carbonate, ethyl methyl carbonate, or diethyl carbonate is more preferable. This is because the dissociation property of the electrolyte salt and the ion mobility are improved.
However, the non-aqueous solvent used in the present invention is not limited by the above examples.

(Functional additives)
The electrolytic solution of the present invention preferably contains various functional additives. Examples of the function manifested by this additive include improved flame retardancy, improved cycle characteristics, and improved capacity characteristics. Examples of functional additives that are preferably applied to the electrolyte of the present invention are shown below.

<Aromatic compound (A)>
Examples of aromatic compounds include biphenyl compounds and alkyl-substituted benzene compounds. The biphenyl compound has a partial structure in which two benzene rings are bonded by a single bond, and the benzene ring may have a substituent, and preferred substituents are alkyl groups having 1 to 4 carbon atoms (for example, , Methyl, ethyl, propyl, t-butyl and the like) and aryl groups having 6 to 10 carbon atoms (for example, phenyl, naphthyl and the like).
Specific examples of the biphenyl compound include biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, 4-methylbiphenyl, 4-ethylbiphenyl, and 4-tert-butylbiphenyl.
The alkyl-substituted benzene compound is preferably a benzene compound substituted with an alkyl group having 1 to 10 carbon atoms. Specifically, ethylbenzene, isopropylbenzene, cyclohexylbenzene, t-amylbenzene, t-butylbenzene, and tetrahydrohydronaphthalene are used. Can be mentioned.

<Halogen-containing compound (B)>
The halogen atom contained in the halogen-containing compound is preferably a fluorine atom, a chlorine atom, or a bromine atom, and more preferably a fluorine atom. The number of halogen atoms is preferably 1 to 6, more preferably 1 to 3. The halogen-containing compound is preferably a carbonate compound substituted with a fluorine atom, a polyether compound having a fluorine atom, or a fluorine-substituted aromatic compound.
The halogen-substituted carbonate compound may be either linear or cyclic. From the viewpoint of ion conductivity, a cyclic carbonate compound having a high coordination property of an electrolyte salt (for example, lithium ion) is preferable, and a 5-membered cyclic carbonate compound is particularly preferable. preferable.
Preferred specific examples of the halogen-substituted carbonate compound are shown below. Among these, compounds of Bex1 to Bex4 are particularly preferable, and Bex1 is particularly preferable.

<Polymerizable compound (C)>
The polymerizable compound is preferably a compound having a carbon-carbon double bond, and is selected from carbonate compounds having a double bond such as vinylene carbonate and vinyl ethylene carbonate, acrylate groups, methacrylate groups, cyanoacrylate groups, and αCF ₃ acrylate groups. A compound having a group and a compound having a styryl group are preferable, and a carbonate compound having a double bond or a compound having two or more polymerizable groups in the molecule is more preferable.

<Phosphorus-containing compound (D)>
As a phosphorus containing compound, it is a phosphorus containing compound other than (1) and (2-1), and a phosphazene compound is preferable. As the phosphorus-containing compound, a compound represented by the following formula (D2) or (D3) is also preferable.

In formula, R ^<D4 > -R <^D11> represents a monovalent substituent. Among the monovalent substituents, preferred are alkyl groups, aryl groups, alkoxy groups, aryloxy groups, halogen atoms such as fluorine, chlorine, bromine and the like. At least one of the substituents R ^{D4 to} R ^D11 is preferably a fluorine atom, and more preferably an alkoxy group or a substituent composed of a fluorine atom.

<Sulfur-containing compound (E)>
As the sulfur-containing compound, compounds having —SO ₂ —, —SO ₃ —, and —OS (═O) O— bonds are preferable, and cyclic sulfur-containing compounds such as propane sultone, propene sultone, and ethylene sulfite, and sulfonic acid Esters are preferred.

  As the sulfur-containing cyclic compound, compounds represented by the following formulas (E1) and (E2) are preferable.

In the formula, X ¹ and X ² each independently represent —O— or —C (Ra) (Rb) —. Here, Ra and Rb each independently represent a hydrogen atom or a substituent. The substituent is preferably an alkyl group having 1 to 8 carbon atoms, a fluorine atom, or an aryl group having 6 to 12 carbon atoms. α represents an atomic group necessary for forming a 5- to 6-membered ring. The skeleton of α may contain a sulfur atom, an oxygen atom, etc. in addition to a carbon atom. α may be substituted, and examples of the substituent include a substituent T, preferably an alkyl group, a fluorine atom, and an aryl group.

<Silicon-containing compound (F)>
As the silicon-containing compound, a compound represented by the following formula (F1) or (F2) is preferable.

R ^F1 represents an alkyl group, an alkenyl group, an acyl group, an acyloxy group, or an alkoxycarbonyl group.
R ^F2 represents an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group.
A plurality of R ^F1 and R ^{F2 in} one formula may be different or the same.

<Nitrile compound (G)>
As the nitrile compound, a compound represented by the following formula (G) is preferable.

In the formula, R ^{G1 to} R ^G3 each independently represent a hydrogen atom, an alkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a cyano group, a carbamoyl group, a sulfonyl group, a halogen atom, or a phosphonyl group. The preferable examples of each substituent can refer to the example of the substituent T, and among them, a compound in which any one of R ^{G1 to} R ^G3 has a plurality of nitrile groups containing a cyano group is preferable.

* Ng represents the integer of 1-8.

  Specific examples of the compound represented by the formula (G) include acetonitrile, propionitrile, isobutyronitrile, succinonitrile, malononitrile, glutaronitrile, adiponitrile, 2-methylglutanonitrile, hexanetricarbonitrile, propane. Tetracarbonitrile and the like are preferable. Particularly preferred are succinonitrile, malononitrile, glutaronitrile, adiponitrile, 2-methylglutanonitrile, hexanetricarbonitrile, and propanetetracarbonitrile.

<Metal complex compound (H)>
As the metal complex compound, a transition metal complex or a rare earth complex is preferable. Especially, the complex represented by either of following formula (H-1)-(H-3) is preferable.

In the formula, X ^H and Y ^H are a methyl group, an n-butyl group, a bis (trimethylsilyl) amino group, and a thioisocyanate group, respectively, and X ^H and Y ^H are condensed to form a cyclic alkenyl group (butadiene group). (Positional metallacycle) may be formed. In the formula, ^MH represents a transition element or a rare earth element. Specifically, ^MH is preferably Fe, Ru, Cr, V, Ta, Mo, Ti, Zr, Hf, Y, La, Ce, Sw, Nd, Lu, Er, Yb, and Gd. m ^H and n ^H are integers satisfying 0 ≦ m ^H + n ^H ≦ 3. n ^H + m ^H is preferably 1 or more. When n ^H and m ^H are 2 or more, the 2 or more groups defined therein may be different from each other.

  The metal complex compound is also preferably a compound having a partial structure represented by the following formula (H-4).

^MH- (NR ^{<1 >} R ^{< 2H>} ) qH ... Formula (H-4)

In the formula, ^MH represents a transition element or a rare earth element and is synonymous with formulas (H-1) to (H-3).

R ^1H and R ^2H are hydrogen, an alkyl group (preferably having 1 to 6 carbon atoms), an alkenyl group (preferably having 2 to 6 carbon atoms), an alkynyl group (preferably having 2 to 6 carbon atoms), an aryl group (preferably having carbon numbers). Represents a heteroaryl group (preferably having a carbon number of 3 to 6), an alkylsilyl group (preferably having a carbon number of 1 to 6), or a halogen. R ^1H and R ^2H may be linked to each other. R ^1H and R ^2H may each be connected to form a ring. Preferable examples of R ^1H and R ^2H include examples of the substituent T described later. Of these, a methyl group, an ethyl group, and a trimethylsilyl group are preferable.
q ^H represents an integer of 1 to 4, and an integer of 2 to 4 is preferable. More preferably, it is 2 or 4. When q ^H is 2 or more, where a plurality of groups as defined may be the same or different from each other.

The metal complex compound is also preferably a compound represented by any of the following formulas.

・ M ^h
The central metal ^M h is, Ti, Zr, ZrO, Hf , V, Cr, Fe, Ce is particularly preferred, Ti, Zr, Hf, V , Cr is the most preferred.

・ R ^3h , R ^5h , R ^{7h to} R ^10h
These represent substituents. Among these, an alkyl group, an alkoxy group, an aryl group, an alkenyl group, and a halogen atom are preferable, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and 2 carbon atoms. -6 alkenyl groups are more preferred, preferably methyl, ethyl, propyl, isopropyl, isobutyl, t-butyl, perfluoromethyl, methoxy, phenyl, ethenyl.

・ R ^33h , R ^55h
R ^33h and R ^55h represent a hydrogen atom or a substituent of R ^3h .

・ Y ^h
Y ^h is preferably an alkyl group or a bis (trialkylsilyl) amino group having 1 to 6 carbon atoms, more preferably a methyl group or a bis (trimethylsilyl) amino group.

^{· L h, m h, o} h
l ^{h, m h, o h} represents an integer of 0 to 3, preferably an integer of 0 to 2. When l ^h , m ^h , and o ^h are 2 or more, the plurality of structural portions defined therein may be the same as or different from each other.

・ L ^h
L ^h is preferably an alkylene group or an arylene group, more preferably a cycloalkylene group having 3 to 6 carbon atoms or an arylene group having 6 to 14 carbon atoms, and further preferably cyclohexylene or phenylene.

<Imide compound (I)>
As the imide compound, a sulfonimide compound having a perfluoro group is preferable from the viewpoint of oxidation resistance, and specifically, a perfluorosulfoimide lithium compound may be mentioned.
Specific examples of the imide compound include the following structures, and Cex1 and Cex2 are more preferable.

  In addition to the above, the electrolytic solution of the present invention may contain at least one selected from a negative electrode film forming agent, a flame retardant, an overcharge preventing agent and the like. The content ratio of these functional additives in the nonaqueous electrolytic solution is not particularly limited, but is preferably 0.001% by mass to 10% by mass with respect to the entire nonaqueous electrolytic solution (including the electrolyte). By adding these compounds, it is possible to suppress battery malfunctions during abnormalities due to overcharging, or to improve capacity maintenance characteristics and cycle characteristics after high-temperature storage.

In addition, in this specification, it uses for the meaning containing the salt and its ion besides the said compound itself about the display of a compound (for example, when attaching | subjecting a compound and an end). In addition, it is meant to include derivatives in which a part thereof is changed, such as introduction of a substituent, within a range where a desired effect is exhibited.
In the present specification, a substituent that does not specify substitution / non-substitution (the same applies to a linking group) means that the group may have an arbitrary substituent. This is also synonymous for compounds that do not specify substitution / non-substitution. Preferred substituents include the following substituent T.
Examples of the substituent T include the following.
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl A group (preferably an alkenyl group having 2 to 20 carbon atoms, such as vinyl, allyl, oleyl, etc.), an alkynyl group (preferably an alkynyl group having 2 to 20 carbon atoms, such as ethynyl, butadiynyl, phenylethynyl, etc.), A cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), an aryl group (preferably an aryl group having 6 to 26 carbon atoms, for example, Phenyl, 1-naphthyl, 4-methoxyphenyl, -Chlorophenyl, 3-methylphenyl, etc.), a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, preferably a 5- or 6-membered heterocycle having at least one oxygen atom, sulfur atom, nitrogen atom) A cyclic group is preferable, for example, tetrahydropyran, tetrahydrofuran, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl and the like, an alkoxy group (preferably having 1 to 20 carbon atoms) Alkoxy groups such as methoxy, ethoxy, isopropyloxy, benzyloxy and the like, aryloxy groups (preferably aryloxy groups having 6 to 26 carbon atoms, such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4- Methoxyphenoxy, etc.), alkoxycarbonyl groups (preferred Or an alkoxycarbonyl group having 2 to 20 carbon atoms such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc., an aryloxycarbonyl group (preferably an aryloxycarbonyl group having 6 to 26 carbon atoms such as phenoxycarbonyl, 1-naphthyloxycarbonyl, 3-methylphenoxycarbonyl, 4-methoxyphenoxycarbonyl, etc.), an amino group (preferably containing an amino group having 0 to 20 carbon atoms, an alkylamino group, an arylamino group, such as amino, N , N-dimethylamino, N, N-diethylamino, N-ethylamino, anilino, etc.), sulfamoyl groups (preferably sulfamoyl groups having 0 to 20 carbon atoms, such as N, N-dimethylsulfamoyl, N-phenyl) Sulfamoyl etc.), acyl group (Preferably an acyl group having 1 to 20 carbon atoms, such as acetyl, propionyl, butyryl, etc.), an aryloyl group (preferably an aryloyl group having 7 to 23 carbon atoms, such as benzoyl), an acyloxy group (preferably carbon An acyloxy group having 1 to 20 atoms, such as acetyloxy, an aryloyloxy group (preferably an aryloyloxy group having 7 to 23 carbon atoms, such as benzoyloxy), and a carbamoyl group (preferably having carbon atoms) 1-20 carbamoyl groups such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl, etc.), acylamino groups (preferably acylamino groups having 1-20 carbon atoms such as acetylamino, benzoylamino, etc.), alkylthio groups (Preferably an alkylthio group having 1 to 20 carbon atoms For example, methylthio, ethylthio, isopropylthio, benzylthio, etc.), arylthio groups (preferably arylthio groups having 6 to 26 carbon atoms, such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc.), An alkylsulfonyl group (preferably an alkylsulfonyl group having 1 to 20 carbon atoms, such as methylsulfonyl and ethylsulfonyl), an arylsulfonyl group (preferably an arylsulfonyl group having 6 to 22 carbon atoms, such as benzenesulfonyl); An alkylsilyl group (preferably an alkylsilyl group having 1 to 20 carbon atoms, such as monomethylsilyl, dimethylsilyl, trimethylsilyl, triethylsilyl, etc.), an arylsilyl group (preferably an arylsilyl group having 6 to 42 carbon atoms) For example, triphenylsilyl, etc.), a phosphoryl group (preferably a phosphate group 0-20 carbon atoms, for ^{example, -OP (= O) (R} P) 2), a phosphonyl group (preferably 0 to 20 carbon atoms the phosphonyl group, for ^{example, -P (= O) (R} P) 2), a phosphinyl group (preferably a phosphinyl group having 0 to 20 carbon atoms, for example, ^-P (R _P) 2), (meth) acryloyl groups , (Meth) acryloyloxy group, hydroxyl group, cyano group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom).
In addition, each of the groups listed as the substituent T may be further substituted with the substituent T described above.
When a compound or a substituent / linking group includes an alkyl group / alkylene group, an alkenyl group / alkenylene group, an alkynyl group / alkynylene group, etc., these may be cyclic or linear, and may be linear or branched These may be substituted as described above or may be unsubstituted.
Each substituent defined in the present specification may be substituted via the following linking group L within a range that exhibits the effects of the present invention. For example, the alkyl group / alkylene group, alkenyl group / alkenylene group and the like may further have the following hetero-linking group interposed in the structure.
Examples of the linking group L include a hydrocarbon linking group [an alkylene group having 1 to 10 carbon atoms (more preferably 1 to 6 carbon atoms, still more preferably 1 to 3), an alkenylene group having 2 to 10 carbon atoms (more preferably carbon atoms). 2 to 6, more preferably 2 to 4), an alkynylene group having 2 to 10 carbon atoms (more preferably 2 to 6, more preferably 2 to 4 carbon atoms), and an arylene group having 6 to 22 carbon atoms (more preferably). Is a carbon number 6-10)], hetero linking group [carbonyl group (—CO—), thiocarbonyl group (—CS—), ether group (—O—), thioether group (—S—), imino group (— NR ^N —), an imine linking group (R ^N —N═C <, —N═C (R ^N ) —)], or a combination of these is preferred. In addition, when condensing and forming a ring, the said hydrocarbon coupling group may form the double bond and the triple bond suitably, and may connect. The ring to be formed is preferably a 5-membered ring or a 6-membered ring. As the five-membered ring, a nitrogen-containing five-membered ring is preferable, and examples of the compound forming the ring include pyrrole, imidazole, pyrazole, indazole, indole, benzimidazole, pyrrolidine, imidazolidine, pyrazolidine, indoline, carbazole, or these And derivatives thereof. Examples of the 6-membered ring include piperidine, morpholine, piperazine, and derivatives thereof. Moreover, when an aryl group, a heterocyclic group, etc. are included, they may be monocyclic or condensed and may be similarly substituted or unsubstituted.
^RN is a hydrogen atom or a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, more preferably 1 to 6 and particularly preferably 1 to 3), and an alkenyl group (preferably having 2 to 24 carbon atoms and 2 -12 are more preferable, 2-6 are more preferable, 2-3 are particularly preferable, and an alkynyl group (C2-C24 is preferable, 2-12 are more preferable, 2-6 are more preferable, and 2-3 are Particularly preferred), an aralkyl group (preferably 7 to 22 carbon atoms, more preferably 7 to 14 carbon atoms, particularly preferably 7 to 10 carbon atoms), an aryl group (preferably 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms, and 6 to 6 carbon atoms). 10 is particularly preferred).
^RP is a hydrogen atom, a hydroxyl group, or a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, more preferably 1 to 6 and particularly preferably 1 to 3), and an alkenyl group (preferably having 2 to 24 carbon atoms and 2 -12 are more preferable, 2-6 are more preferable, 2-3 are particularly preferable, and an alkynyl group (C2-C24 is preferable, 2-12 are more preferable, 2-6 are more preferable, and 2-3 are Particularly preferred), an aralkyl group (preferably 7 to 22 carbon atoms, more preferably 7 to 14 carbon atoms, particularly preferably 7 to 10 carbon atoms), an aryl group (preferably 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms, and 6 to 6 carbon atoms). 10 is particularly preferred), an alkoxy group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, even more preferably 1 to 6 and particularly preferably 1 to 3), an alkenyloxy group (having carbon numbers). To 24, more preferably 2 to 12, more preferably 2 to 6, particularly preferably 2 to 3, and alkynyloxy group (2 to 24 carbon atoms are preferred, 2 to 12 are more preferred, and 2 to 6 are preferred). More preferably, 2 to 3 are particularly preferable), an aralkyloxy group (preferably 7 to 22 carbon atoms, more preferably 7 to 14 carbon atoms, particularly preferably 7 to 10 carbon atoms), an aryloxy group (preferably 6 to 22 carbon atoms, 6 to 14 are more preferable, and 6 to 10 are particularly preferable.
In the present specification, the number of atoms constituting the linking group is preferably 1 to 36, more preferably 1 to 24, still more preferably 1 to 12, and 1 to 6. Is particularly preferred. The number of linking atoms in the linking group is preferably 10 or less, and more preferably 8 or less. The lower limit is 1 or more. The number of connected atoms refers to the minimum number of atoms that are located in a path connecting predetermined structural portions and are involved in the connection. For example, in the case of —CH ₂ —C (═O) —O—, the number of atoms constituting the linking group is 6, but the number of linking atoms is 3.
Specific examples of combinations of linking groups include the following. Oxycarbonyl group (OCO), carbonate group (OCOO), amide group (CONH), urethane group (NHCOO), urea group (NHCONH), (poly) alkyleneoxy group (-(Lr-O) x-), carbonyl ( Poly) oxyalkylene group (—CO— (O—Lr) x —, carbonyl (poly) alkyleneoxy group (—CO— (Lr—O) x—), carbonyloxy (poly) alkyleneoxy group (—COO— ( Lr-O) x -), ( poly) alkyleneimino group ^{(- (Lr-NR N)} x), alkylene (poly) iminoalkylene group ^{(-Lr- (NR N -Lr) x-} ), carbonyl (poly) iminoalkylene group ^{(-CO- (NR N -Lr) x-} ), carbonyl (poly) alkyleneimino group ^{(-CO- (Lr-NR N)} x -), ( poly) S. Group (-(CO-O-Lr) x-,-(O-CO-Lr) x-,-(O-Lr-CO) x-,-(Lr-CO-O) x-,-(Lr -O-CO) x -), ( poly) amide group ^{(- (CO-NR N -Lr} ) x -, - (NR N -CO-Lr) x -, - (NR N -Lr-CO) x- ^{, - (Lr-CO-NR} N) x -, - (Lr-NR N -CO) x-) is located .x is an integer of 1 or more, etc., preferably 1 to 500, more preferably 1 to 100 .
Lr is preferably an alkylene group, an alkenylene group or an alkynylene group. 1-12 are preferable, as for carbon number of Lr, 1-6 are more preferable, and 1-3 are especially preferable. A plurality of Lr, R ^N , R ^P , x, etc. need not be the same. The direction of the linking group is not limited by the above description, and may be understood as appropriate according to a predetermined chemical formula.

[Method for preparing electrolytic solution]
The nonaqueous electrolytic solution of the present invention is prepared by a conventional method by dissolving each of the above components in the nonaqueous electrolytic solution solvent, including an example in which a lithium salt is used as a metal ion salt.

  In the present invention, “non-water” means that water is not substantially contained, and a trace amount of water may be contained as long as the effects of the invention are not hindered. In view of obtaining good characteristics, the concentration of water is preferably 200 ppm (mass basis) or less, more preferably 100 ppm or less, and still more preferably 20 ppm or less. Although there is no lower limit in particular, it is practical that it is 1 ppm or more considering inevitable mixing. The viscosity of the electrolytic solution of the present invention is not particularly limited, but is preferably 10 to 0.1 mPa · s, more preferably 5 to 0.5 mPa · s at 25 ° C.

<Measurement method of viscosity>
In the present specification, the viscosity is a value measured by the following method. 1 mL of a sample is put into a rheometer (CLS 500) and measured using a Steel Cone (both manufactured by TA Instruments) having a diameter of 4 cm / 2 °. The sample is kept warm in advance until the temperature becomes constant at the measurement start temperature, and the measurement starts thereafter. The measurement temperature is 25 ° C.

[Secondary battery]
In this invention, it is preferable to set it as the non-aqueous secondary battery containing the said non-aqueous electrolyte. As a preferred embodiment, a lithium ion secondary battery will be described with reference to FIG. 1 schematically showing the mechanism. The lithium ion secondary battery 10 of this embodiment includes the electrolyte solution 5 for a non-aqueous secondary battery of the present invention and a positive electrode C capable of inserting and releasing lithium ions (a positive electrode current collector 1 and a positive electrode active material layer 2). And a negative electrode A (negative electrode current collector 3, negative electrode active material layer 4) capable of inserting and releasing lithium ions or dissolving and depositing lithium ions. In addition to these essential members, considering the purpose of use of the battery, the shape of the potential, etc., a separator 9 disposed between the positive electrode and the negative electrode, a current collecting terminal (not shown), an outer case, etc. (Not shown). If necessary, a protective element may be attached to at least one of the inside of the battery and the outside of the battery. By adopting such a structure, lithium ion transfer a and b occurs in the electrolytic solution 5, charging α and discharging β can be performed, and operation or power storage is performed via the operation mechanism 6 via the circuit wiring 7. It can be performed. Hereinafter, the configuration of the lithium secondary battery which is a preferred embodiment of the present invention will be described in more detail.

(Battery shape)
The battery shape to which the lithium secondary battery of the present embodiment is applied is not particularly limited, and examples thereof include a bottomed cylindrical shape, a bottomed square shape, a thin shape, a sheet shape, and a paper shape. Any of these may be used. Further, it may be of a different shape such as a horseshoe shape or a comb shape considering the shape of the system or device to be incorporated. Among them, from the viewpoint of efficiently releasing the heat inside the battery to the outside, a square shape such as a bottomed square shape or a thin shape having at least one surface that is relatively flat and has a large area is preferable.

  In a battery having a bottomed cylindrical shape, since the outer surface area with respect to the power generating element to be filled becomes small, it is preferable to design so that Joule heat generated by the internal resistance at the time of charging and discharging efficiently escapes to the outside. Moreover, it is preferable to design so that the filling ratio of the substance having high thermal conductivity is increased and the temperature distribution inside is reduced. FIG. 2 is an example of a bottomed cylindrical lithium secondary battery 100. This battery is a bottomed cylindrical lithium secondary battery 100 in which a positive electrode sheet 14 and a negative electrode sheet 16 overlapped with a separator 12 are wound and accommodated in an outer can 18.

In the bottomed square shape, the ratio of the area S of the largest surface (the product of the width and height of the outer dimensions excluding the terminal portion, unit cm ² ) to the thickness T (unit cm) of the battery outer shape The 2S / T value is preferably 100 or more, and more preferably 200 or more. By increasing the maximum surface, it is possible to improve characteristics such as cycle performance and high-temperature storage even for high-power and large-capacity batteries, and increase the heat dissipation efficiency in the event of abnormal heat generation. It can suppress becoming a state.

(Members constituting the battery)
The lithium secondary battery according to the present embodiment is configured to include the electrolytic solution 5, the positive electrode and negative electrode electrode mixtures C and A, and the separator basic member 9, based on FIG. 1. Hereinafter, each of these members will be described.
(Electrode mixture)
The electrode mixture is obtained by applying a dispersion of an active material and a conductive agent, a binder, a filler, etc. on a current collector (electrode substrate). In a lithium battery, the active material is a positive electrode active material. It is preferable to use a negative electrode mixture in which the positive electrode mixture and the active material are a negative electrode active material. Next, each component in the dispersion (electrode composition) constituting the electrode mixture will be described.

-Positive electrode active material It is preferable to use a transition metal oxide for the positive electrode active material, and in particular, it has a transition element M ^a (one or more elements selected from Co, Ni, Fe, Mn, Cu, V). Is preferred. Further, mixed element M ^b (elements of the first (Ia) group of the metal periodic table other than lithium, elements of the second (IIa) group, Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si , P, B, etc.) may be mixed. This, for example, as a transition metal oxide, the following formula (MA) ~ certain transition metal oxides including those represented by any one of (MC), or _V 2 _O 5 as other transition metal oxides, MnO _2, etc. Is mentioned. As the positive electrode active material, a particulate positive electrode active material may be used. Specifically, a transition metal oxide capable of reversibly inserting and releasing lithium ions can be used, but the specific transition metal oxide is preferably used.

The transition metal oxides, oxides containing the above transition element M ^a is preferably exemplified. At this time, a mixed element M ^b (preferably Al) or the like may be mixed. The mixing amount is preferably 0 to 30 mol% with respect to the amount of the transition metal. That the molar ratio of li / ^{M a} is synthesized by mixing so that 0.3 to 2.2 is more preferable.

[Transition metal oxide represented by formula (MA) (layered rock salt structure)]
As the lithium-containing transition metal oxide, those represented by the following formula are preferable.
Li _a M ¹ O _b (MA)

Wherein, ^{M 1} is as defined above Ma. a represents 0 to 1.2, preferably 0.1 to 1.15, and more preferably 0.6 to 1.1. b represents 1-3 and is preferably 2. A part of M ¹ may be substituted with the mixed element M ^b . The transition metal oxide represented by the above formula (MA) typically has a layered rock salt structure.

The transition metal oxide is more preferably one represented by the following formulas.
_{(MA-1) Li g CoO} k
_{(MA-2) Li g NiO} k
_{(MA-3) Li g MnO} k
_{(MA-4) Li g Co} j Ni 1-j O k
_{(MA-5) Li g Ni} j Mn 1-j O k
_{(MA-6) Li g Co} j Ni i Al 1-j-i O k
_{(MA-7) Li g Co} j Ni i Mn 1-j-i O k

Here, g has the same meaning as a. j represents 0.1 to 0.9. i represents 0 to 1; However, 1-j-i is 0 or more. k has the same meaning as b above. Specific examples of the transition metal compound include LiCoO ₂ (lithium cobaltate [LCO]), LiNi ₂ O ₂ (lithium nickelate) LiNi _0.85 Co _0.01 Al _0.05 O ₂ (nickel cobalt aluminum acid Lithium [NCA]), LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (lithium nickel manganese cobaltate [NMC]), LiNi _0.5 Mn _0.5 O ₂ (lithium manganese nickelate).

The transition metal oxide represented by the formula (MA) partially overlaps, but when represented by changing the notation, those represented by the following are also preferable examples.
_{(I) Li g Ni x Mn} y Co z O 2 (x> 0.2, y> 0.2, z ≧ 0, x + y + z = 1)
Representative:
_{Li g Ni 1/3 Mn 1/3 Co 1/3} O 2
Li _g Ni _1/2 Mn _1/2 O _{2
(Ii) Li g Ni x Co} y Al z O 2 (x> 0.7, y>0.1,0.1> z ≧ 0.05, x + y + z = 1)
Representative:
_{Li g Ni 0.8 Co 0.15 Al 0.05} O 2

[Transition metal oxide represented by formula (MB) (spinel structure)]
Among the lithium-containing transition metal oxides, those represented by the following formula (MB) are also preferable.
Li _c M ² ₂ O _d (MB)

Wherein, ^{M 2} is as defined above Ma. c represents 0 to 2, preferably 0.1 to 1.15, and more preferably 0.6 to 1.5. d represents 3 to 5 and is preferably 4.

The transition metal oxide represented by the formula (MB) is more preferably one represented by the following formulas.
_{(MB-1) Li m Mn} 2 O n
_{(MB-2) Li m Mn} p Al 2-p O n
_{(MB-3) Li m Mn} p Ni 2-p O n

m is synonymous with c. n is synonymous with d. p represents 0-2. Specific examples of the transition metal compound are LiMn ₂ O ₄ and LiMn _1.5 Ni _0.5 O ₄ .

Preferred examples of the transition metal oxide represented by the formula (MB) include those represented by the following.
(A) LiCoMnO ₄
(B) Li ₂ FeMn ₃ O ₈
(C) Li ₂ CuMn ₃ O ₈
(D) Li ₂ CrMn ₃ O ₈
(E) Li ₂ NiMn ₃ O ₈
Of these, an electrode containing Ni is more preferable from the viewpoint of high capacity and high output.

[Transition metal oxide represented by formula (MC)]
As the lithium-containing transition metal oxide, it is also preferable to use a lithium-containing transition metal phosphor oxide, and among them, one represented by the following formula (MC) is also preferable.
Li _e M ³ (PO ₄ ) _f ... (MC)

  In the formula, e represents 0 to 2, preferably 0.1 to 1.15, and more preferably 0.5 to 1.5. f represents 1 to 5 and is preferably 0.5 to 2.

The M ³ represents one or more elements selected from V, Ti, Cr, Mn, Fe, Co, Ni, and Cu. The ^{M 3} are, in addition to the mixing element ^{M b} above, Ti, Cr, Zn, Zr, may be substituted by other metals such as Nb. Specific examples include, for example, olivine-type iron phosphates such as LiFePO ₄ and Li ₃ Fe ₂ (PO ₄ ) ₃ , iron pyrophosphates such as LiFeP ₂ O ₇ , cobalt phosphates such as LiCoPO ₄ , and Li _3. Monoclinic Nasicon type vanadium phosphate salts such as V ₂ (PO ₄ ) ₃ (lithium vanadium phosphate) can be mentioned.
The a, c, g, m, and e values representing the composition of Li are values that change due to charging and discharging, and are typically evaluated as values in a stable state when Li is contained. In the above formulas (a) to (e), the composition of Li is shown as a specific value, but this also varies depending on the operation of the battery.
In particular, in the present invention, a positive electrode active material containing nickel and / or manganese atoms is preferably used, and a positive electrode active material containing both nickel and manganese atoms is more preferably used.
Specific examples of particularly preferable positive electrode active materials include the following.
LiNi _0.33 Co _0.33 Mn _0.33 O ₂
LiNi _0.6 Co _0.2 Mn _0.2 O ₂
LiNi _0.8 Co _0.1 Mn _0.1 O ₂
LiNi _0.5 Co _0.3 Mn _0.2 O ₂
LiNi _0.5 Mn _0.5 O ₂
LiNi _0.5 Mn _1.5 O ₄
Since these can be used at a high potential, the battery capacity can be increased, and even when used at a high potential, the capacity retention rate is high, which is particularly preferable.

In the present invention, the positive electrode active material is preferably a material that can maintain normal use at a positive electrode potential (Li / Li ⁺ standard) of 3.5 V or higher, more preferably 3.8 V or higher, and more preferably 4 V or higher. More preferably, it is more preferably 4.25V or more, and further preferably 4.3V or more. Although there is no upper limit in particular, it is practical that it is 5V or less. By setting it as the above range, cycle characteristics and high rate discharge characteristics can be improved.
Here, being able to maintain normal use means that even when charging is performed at that voltage, the electrode material does not deteriorate and cannot be used, and this potential is also referred to as a normal usable potential.
The positive electrode potential during charging / discharging (Li / Li ⁺ reference) is (positive electrode potential) = (negative electrode potential) + (battery voltage). When lithium titanate is used as the negative electrode, the negative electrode potential is 1.55V. When graphite is used as the negative electrode, the negative electrode potential is 0.1V. The battery voltage is observed during charging and the positive electrode potential is calculated.

  The nonaqueous electrolytic solution of the present invention is particularly preferably used in combination with a positive electrode that can be used up to a high potential. When a positive electrode having a high potential is used, the cycle characteristics tend to be greatly deteriorated. However, the nonaqueous electrolytic solution of the present invention can maintain good performance with this decrease suppressed. This is also an advantage and feature of the preferred embodiment of the present invention.

In the non-aqueous secondary battery of the present invention, the average particle size of the positive electrode active material used is not particularly limited, but is preferably 0.1 μm to 50 μm. No particular limitation is imposed on the specific surface area, preferably from 0.01m ² / g~50m ² / g by the BET method. Further, the pH of the supernatant when 5 g of the positive electrode active material is dissolved in 100 ml of distilled water is preferably 7 or more and 12 or less.

  To make the positive electrode active material have a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a vibration ball mill, a vibration mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill, a sieve, or the like is used. The positive electrode active material obtained by the above firing method may be used after washing with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

Although the compounding quantity of a positive electrode active material is not specifically limited, In the dispersion (mixture) for comprising an active material layer, it is preferable that it is 60-98 mass% in 100 mass% of solid components, and is 70-95 mass. % Is more preferable.
・ Negative electrode active material As the negative electrode active material, those capable of reversibly inserting and releasing lithium ions are preferable, and there is no particular limitation. Carbonaceous materials, metal oxides such as tin oxide and silicon oxide, metal composite oxides, lithium Examples thereof include a single alloy and a lithium alloy such as a lithium aluminum alloy, and a metal capable of forming an alloy with lithium such as Sn and Si.
These may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Of these, carbonaceous materials or lithium composite oxides are preferably used from the viewpoint of reliability.
Further, the metal composite oxide is preferably capable of occluding and releasing lithium, and preferably contains titanium and / or lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics.

  The carbonaceous material used as the negative electrode active material is a material substantially made of carbon. Examples thereof include carbonaceous materials obtained by baking various synthetic resins such as artificial pitches such as petroleum pitch, natural graphite, and vapor-grown graphite, and PAN-based resins and furfuryl alcohol resins. Furthermore, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA-based carbon fiber, lignin carbon fiber, glassy carbon fiber, activated carbon fiber, mesophase micro Examples thereof include spheres, graphite whiskers, and flat graphite.

  These carbonaceous materials can be divided into non-graphitizable carbon materials and graphite-based carbon materials depending on the degree of graphitization. Further, the carbonaceous material preferably has the surface spacing, density, and crystallite size described in JP-A-62-222066, JP-A-2-6856, and 3-45473. The carbonaceous material does not need to be a single material, and a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, or the like is used. You can also.

  It is preferable that the metal oxide and metal composite oxide which are negative electrode active materials used in the non-aqueous secondary battery of the present invention contain at least one of them. As the metal oxide and metal complex oxide, amorphous oxide is particularly preferable, and chalcogenite, which is a reaction product of a metal element and an element of Group 16 of the periodic table, is also preferably used. The term “amorphous” as used herein means an X-ray diffraction method using CuKα rays, which has a broad scattering band having an apex in the region of 20 ° to 40 ° in terms of 2θ values, and is a crystalline diffraction line. You may have. The strongest intensity of crystalline diffraction lines seen from 2 ° to 40 ° to 70 ° is 100 times the diffraction line intensity at the peak of the broad scattering band seen from 2 ° to 20 °. It is preferable that it is 5 times or less, and it is particularly preferable not to have a crystalline diffraction line.

Among the group of compounds consisting of the above amorphous oxide and chalcogenide, amorphous metal oxides and chalcogenides are more preferable, and elements in Groups 13 (IIIB) to 15 (VB) of the periodic table, Particularly preferred are oxides and chalcogenides composed of one kind of Al, Ga, Si, Sn, Ge, Pb, Sb, Bi or a combination of two or more kinds thereof. Specific examples of preferable amorphous oxides and chalcogenides include, for example, Ga ₂ O ₃ , SiO, GeO, SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ O ₄ , SnSiO ₃ , GeS, SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ , such as SnSiS ₃ may preferably be mentioned. Moreover, these may be a complex oxide with lithium oxide, for example, Li ₂ SnO ₂ .

  In the nonaqueous secondary battery of the present invention, the average particle size of the negative electrode active material used is preferably 0.1 μm to 60 μm. To obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill or a sieve is preferably used. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle size, classification is preferably performed. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be used both dry and wet.

  The chemical formula of the compound obtained by the above firing method can be calculated from an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method, and from a mass difference between powders before and after firing as a simple method.

  In the present invention, as the negative electrode active material that can be used in combination with the amorphous oxide negative electrode active material centering on Sn, Si, Ge, a carbon material capable of inserting and extracting lithium ions or lithium metal, lithium, Preferred examples include lithium alloys and metals that can be alloyed with lithium.

The electrolyte of the present invention is preferably combined with a high potential negative electrode (preferably lithium / titanium oxide, a potential of 1.55 V vs. Li metal) and a low potential negative electrode (preferably a carbon material, a silicon-containing material, a potential of about 0). Excellent properties are exhibited in any combination with .1V vs. Li metal. Further, metal or metal oxide negative electrodes (preferably Si, Si oxide, Si / Si oxide, Sn, Sn oxide, SnB _x P _y O _z , Cu, which can be alloyed with lithium, which are being developed for higher capacity) / Sn and a plurality of these composites), and a battery using a composite of these metals or metal oxides and a carbon material as a negative electrode.
In the present invention, it is particularly preferable to use a negative electrode active material containing at least one selected from carbon, silicon, titanium, and tin.
The nonaqueous electrolytic solution of the present invention is particularly preferably used in combination with a high potential negative electrode. The high potential negative electrode is often used in combination with the above high potential positive electrode, and can suitably cope with charge and discharge of a large capacity. Under such conditions, the above conditions (I) to (III) It is the same as that described in the section of the positive electrode active material that exhibits the advantages according to the preferred embodiment of the present invention having the specific composition set in the above.

-Conductive material The conductive material is preferably an electron conductive material that does not cause a chemical change in the configured secondary battery, and a known conductive material can be arbitrarily used. Usually, natural graphite (scale-like graphite, scale-like graphite, earth-like graphite, etc.), artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber and metal powder (copper, nickel, aluminum, silver (Japanese Patent Laid-Open No. Sho 63- 10148,554)), metal fibers or polyphenylene derivatives (described in JP-A-59-20971) can be contained as a single type or a mixture thereof. Among these, the combined use of graphite and acetylene black is particularly preferable. As addition amount of the said electrically conductive agent, 11-50 mass% is preferable and 2-30 mass% is more preferable. In the case of carbon or graphite, 2 to 15% by mass is particularly preferable.

-Binders Examples of binders include polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Among them, for example, starch, carboxymethyl cellulose, cellulose, diacetyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose. , Sodium alginate, polyacrylic acid, sodium polyacrylate, polyvinyl phenol, polyvinyl methyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylonitrile, polyacrylamide, polyhydroxy (meth) acrylate, styrene-maleic acid copolymer, etc. Polymer, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinyl (Meta) such as redene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate (Meth) acrylic ester copolymer containing acrylic ester, (meth) acrylic ester-acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene-butadiene copolymer, Acrylonitrile-butadiene copolymer, polybutadiene, neoprene rubber, fluororubber, polyethylene oxide, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polymer Urethane resins, polyester resins, phenolic resins, emulsion (latex) or a suspension such as an epoxy resin is preferable, a latex of polyacrylate, carboxymethyl cellulose, polytetrafluoroethylene, polyvinylidene fluoride is more preferable.

  A binder can be used individually by 1 type or in mixture of 2 or more types. When the amount of the binder added is small, the holding power and cohesive force of the electrode mixture are weakened. If the amount is too large, the electrode volume increases and the capacity per electrode unit volume or unit mass decreases. For this reason, the addition amount of the binder is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass.

-Filler The electrode compound material may contain the filler. The material forming the filler is preferably a fibrous material that does not cause a chemical change in the secondary battery of the present invention. Usually, fibrous fillers made of materials such as olefin polymers such as polypropylene and polyethylene, glass, and carbon are used. Although the addition amount of a filler is not specifically limited, 0-30 mass% is preferable in a dispersion.

-Current collector As the positive / negative electrode current collector, an electron conductor that does not cause a chemical change in the nonaqueous electrolyte secondary battery of the present invention is used. As the current collector of the positive electrode, in addition to aluminum, stainless steel, nickel, titanium, etc., the surface of aluminum or stainless steel is preferably treated with carbon, nickel, titanium, or silver. Among them, aluminum and aluminum alloys are preferable. More preferred.

  As the negative electrode current collector, aluminum, copper, stainless steel, nickel, and titanium are preferable, and aluminum, copper, and a copper alloy are more preferable.

As the shape of the current collector, a film sheet shape is usually used, but a net, a punched material, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like can also be used. Although it does not specifically limit as thickness of the said electrical power collector, 1 micrometer-500 micrometers are preferable. Moreover, it is also preferable that the current collector surface is roughened by surface treatment.
An electrode mixture of the lithium secondary battery is formed by a member appropriately selected from these materials.

(Separator)
The separator used in the non-aqueous secondary battery of the present invention is made of a material that mechanically insulates the positive electrode and the negative electrode, has ion permeability, and has oxidation / reduction resistance at the contact surface between the positive electrode and the negative electrode. Preferably it is. As such a material, a porous polymer material, an inorganic material, an organic-inorganic hybrid material, glass fiber, or the like is used. These separators preferably have a shutdown function for ensuring reliability, that is, a function of closing a gap at 80 ° C. or higher to increase resistance and blocking current, and a closing temperature is 90 ° C. or higher and 180 ° C. or lower. It is preferable.

  The shape of the holes of the separator is usually a circle or an ellipse, and the size is 0.05 μm to 30 μm, preferably 0.1 μm to 20 μm. Furthermore, it may be a rod-like or irregular-shaped hole as in the case of making by a stretching method or a phase separation method. The ratio of these gaps, that is, the porosity, is 20% to 90%, preferably 35% to 80%.

  As said polymer material, the thing using a single material, such as a cellulose nonwoven fabric, polyethylene, a polypropylene, or a composite material of 2 or more types may be used. What laminated | stacked the 2 or more types of microporous film which changed the hole diameter, the porosity, the obstruction | occlusion temperature of a hole, etc. is preferable.

  Examples of the inorganic material include oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate, and those having a particle shape or fiber shape are used. As the form, a thin film shape such as a non-woven fabric, a woven fabric, or a microporous film is used. In the thin film shape, those having a pore diameter of 0.01 μm to 1 μm and a thickness of 5 μm to 50 μm are preferably used. In addition to the above-described independent thin film shape, a separator formed by forming a composite porous layer containing the inorganic particles on the surface layer of the positive electrode and / or the negative electrode using a resin binder can be used. For example, alumina particles having a 90% particle diameter of less than 1 μm are formed on both surfaces of the positive electrode as a porous layer using a fluororesin binder.

(Production of non-aqueous secondary battery)
As described above, the shape of the nonaqueous secondary battery of the present invention can be applied to any shape such as a sheet shape, a square shape, and a cylinder shape. A positive electrode active material or a mixture of negative electrode active materials is mainly used after being applied (coated), dried and compressed on a current collector.

  Hereinafter, with reference to FIG. 2, a configuration and a manufacturing method thereof will be described using the bottomed cylindrical lithium secondary battery 100 as an example. In a battery having a bottomed cylindrical shape, since the outer surface area with respect to the power generating element to be filled becomes small, it is preferable to design so that Joule heat generated by the internal resistance at the time of charging and discharging efficiently escapes to the outside. Moreover, it is preferable to design so that the filling ratio of the substance having high thermal conductivity is increased and the temperature distribution inside is reduced. FIG. 2 shows an example of a bottomed cylindrical lithium secondary battery 100. This battery is a bottomed cylindrical lithium secondary battery 100 in which a positive electrode sheet 14 and a negative electrode sheet 16 overlapped with a separator 12 are wound and accommodated in an outer can 18. In addition, in the figure, 20 is an insulating plate, 22 is a sealing plate, 24 is a positive electrode current collector, 26 is a gasket, 28 is a pressure sensitive valve body, and 30 is a current interruption element. In addition, although the illustration in the enlarged circle has changed hatching in consideration of visibility, each member corresponds to the whole drawing by reference numerals.

  First, a negative electrode active material is mixed with a binder or filler used as desired in an organic solvent to prepare a slurry-like or paste-like negative electrode mixture. The obtained negative electrode mixture is uniformly applied over the entire surface of both surfaces of the metal core as a current collector, and then the organic solvent is removed to form a negative electrode mixture layer. Further, the laminate of the current collector and the negative electrode composite material layer is rolled with a roll press or the like to prepare a predetermined thickness to obtain a negative electrode sheet (electrode sheet). At this time, the coating method of each agent, the drying of the coated material, and the method of forming the positive and negative electrodes may be in accordance with conventional methods.

  In the present embodiment, a cylindrical battery is taken as an example, but the present invention is not limited to this, for example, after the positive and negative electrode sheets produced by the above method are overlapped via a separator, After processing into a sheet battery as it is, or inserting it into a rectangular can after being folded and electrically connecting the can and the sheet, injecting an electrolyte and sealing the opening using a sealing plate A square battery may be formed.

  In any embodiment, the safety valve can be used as a sealing plate for sealing the opening. In addition to the safety valve, the sealing member may be provided with various conventionally known safety elements. For example, a fuse, bimetal, PTC element, or the like is preferably used as the overcurrent prevention element.

  In addition to the safety valve, as a countermeasure against the increase in internal pressure of the battery can, a method of cutting the battery can, a method of cracking the gasket, a method of cracking the sealing plate, or a method of cutting the lead plate can be used. Further, the charger may be provided with a protection circuit incorporating measures against overcharge and overdischarge, or may be connected independently.

  For the can and lead plate, a metal or alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper, and aluminum, or alloys thereof are preferably used.

  As a method for welding the cap, the can, the sheet, and the lead plate, a known method (eg, direct current or alternating current electric welding, laser welding, ultrasonic welding) can be used. As the sealing agent for sealing, a conventionally known compound or mixture such as asphalt can be used.

[Applications of non-aqueous secondary batteries]

Secondary batteries called lithium batteries are secondary batteries that use the insertion and extraction of lithium for charge / discharge reactions (lithium ion secondary batteries), and secondary batteries that use precipitation and dissolution of lithium (lithium metal secondary batteries). ). In the present invention, application as a lithium ion secondary battery is preferable.
Since the nonaqueous secondary battery of the present invention can produce a secondary battery with good cycle performance, it is applied to various applications. Although there is no particular limitation on the application mode, for example, when installed in an electronic device, a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone, a pager, a handy terminal, a mobile fax machine, a mobile phone Copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, minidisc, electric shaver, walkie-talkie, electronic notebook, calculator, memory card, portable tape recorder, radio, backup power supply, memory card, etc. It is done. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, and shoulder grinders). Furthermore, it can be used for various military use and space use. Moreover, it can also combine with a solar cell.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited thereto. In the following examples, “parts” and “%” are based on mass unless otherwise specified.
<Example 1 and Comparative Example 1>
Preparation of Electrolytic Solution Compounds (1) and (2) are added to the solvents S1 to S3 of the electrolytic solution in Table 1 so as to have the amounts shown in the table, and vinylene carbonate is 1% by mass with respect to the total electrolytic solution. Thus, an electrolytic solution for each test was prepared. All the prepared electrolyte solutions had a viscosity at 25 ° C. of 5 mPa · s or less, and the moisture content measured by the Karl Fischer method (JISK0113) was 20 ppm (mass basis) or less.

<Flame retardance>
The flame retardancy of the prepared electrolyte was evaluated as follows at 25 ° C. in the atmosphere.
The following test system was used for evaluation with reference to the UL-94HB horizontal combustion test. A glass filter paper (ADVANTEC GA-100) having a width of 13 mm and a length of 110 mm was cut out, and 1.5 ml of the prepared electrolyte was evenly dropped onto the glass filter paper. After the electrolyte solution was sufficiently infiltrated into the glass filter paper, the excess electrolyte solution was wiped and hung so as to be horizontal. The butane gas burner adjusted to a total flame length of 2 cm ignites for 3 seconds from the position where it touches the tip of the glass filter paper. The arrival time was evaluated as follows. The time for the flame to reach from the ignition point to the other end of the electrolyte solution to which no additive was added was less than 5 seconds.
5 ... Ignition was not seen and it was nonflammable.
4 ... I ignited but immediately extinguished 3 ... I ignited but extinguished before the flame reached from the ignition point to the other end 2 ... Time to reach the flame from the ignition point to the other end 10 seconds In the above, the combustion suppression effect is seen, but the level which does not lead to non-flammability and flame extinguishing 1... The flame reaches from the ignition point to the other end in less than 10 seconds and there is no combustion suppression effect.

<Production of battery (1)>
The positive electrode is made of active material: LiNi _1/3 Mn _1/3 Co _1/3 O ₂ (NMC) 85% by mass, conductive auxiliary agent: carbon black 7.5% by mass, binder: PVDF 7.5% by mass, The negative electrode was made of active material: 85% by mass of graphite, conductive auxiliary agent: 7.5% by mass of carbon black, and binder: 7.5% by mass of PVDF. The separator is a polypropylene porous membrane having a thickness of 24 μm. Using the above positive and negative electrodes and separator, a 2032 type coin battery (1) was prepared using the above electrolytic solution.

<Battery initialization>
Charged at a constant current of 0.2 C until the battery voltage reaches 4.3 V (positive electrode potential 4.4 V) in a thermostat at 30 ° C., and then charged until the battery voltage reaches a current value of 0.12 mA at a constant voltage of 4.3 V. Went. However, the upper limit of the time was 2 hours. Next, 0.2 C constant current discharge was performed until the battery voltage became 2.75 V in a 30 ° C. constant temperature bath. This operation was repeated twice. The following items were evaluated using the 2032 type battery produced by the above method. The results are shown in Table 1.
Here, 1C represents a current value for discharging or charging the battery capacity in one hour, 0.2C represents 0.2 times, 0.5C represents 0.5 times, and 2C represents twice the current value. . As charging / discharging with a large current is more likely to be affected by an increase in resistance, the capacity is likely to deteriorate. Similarly, since it is easy to be affected by an increase in resistance when discharged at a low temperature, the capacity is likely to deteriorate, and a low temperature large current discharge combining the two becomes a more severe condition.
In addition, the temperature in the cycle test is also important. When charging and discharging are repeated at a high temperature, the oxidation-reduction decomposition of the electrolytic solution component is accelerated and the resistance is likely to increase.

(First discharge capacity)
This battery was charged at a constant current of 0.7 C in a thermostat at 30 ° C. until the battery voltage became 4.3 V, and then charged at a constant voltage of the battery voltage of 4.3 V until the current value reached 0.12 mA. However, the upper limit of the time was 2 hours. This battery was subjected to 0.5C constant current discharge in a thermostatic chamber at 30 ° C. until the battery voltage reached 2.75 V, and the initial 30 ° C./0.5C discharge capacity (I) was measured.
(High temperature cycle test)
This battery was charged at a constant current of 0.7 C in a 45 ° C. constant temperature bath until the battery voltage reached 4.3 V, and then charged at a constant voltage of 4.3 V until the current value reached 0.12 mA. However, the upper limit of the time was 2 hours. A cycle of performing 0.5C constant current discharge of this battery in a thermostat at 45 ° C. until the battery voltage reached 2.75 V was repeated 300 times.
(Discharge capacity after cycle test)
The battery after the high-temperature cycle test was charged and discharged under the same conditions as the initial discharge capacity measurement, and the discharge capacity (II) after the cycle test was measured.
(Low temperature, large current discharge capacity after cycle test)
The battery after the high-temperature cycle test was charged at a constant current of 0.7 C in a thermostat bath at 30 ° C. until the battery voltage reached 4.3 V, and then charged until the current value reached 0.12 mA at a constant voltage of 4.3 V. Went. However, the upper limit of the time was 2 hours. The battery was subjected to 2C constant current discharge in a 10 ° C constant temperature bath until the battery voltage reached 2.75 V, and the 10 ° C / 2C discharge capacity (III) after the cycle test was measured.

From the obtained results, the discharge capacity retention rate after the cycle test and the low temperature high current discharge capacity retention rate after the cycle test were calculated according to the following equations.
Discharge capacity maintenance ratio after cycle test = (II) / (I)
Low-temperature, large-current discharge capacity retention rate after cycle test = (III) / (I)

The obtained discharge capacity retention rate was evaluated as follows. The larger the value, the higher the capacity is maintained even under severe test conditions.
A: 0.8 or more B: 0.7 or more and less than 0.8 C: 0.6 or more and less than 0.7 D: 0.5 or more and less than 0.6 E: 0.3 or more and less than 0.5 F: 0. Less than 3

試験Ｎｏ．：ｃで始まるものが比較例
ｃｏｍｐ：例示化合物
ｃｏｎｃ：濃度（質量％）

Test No. : Starting with c is a comparative example comp: Exemplified compound conc: Concentration (mass%)

溶剤
ＥＣ：エチレンカーボネート
ＥＭＣ：エチルメチルカーボネート
ＤＭＣ：ジメチルカーボネート
ＧＢＬ：γブチロラクトン
ＰＣ：プロピレンカーボネート

Solvent EC: Ethylene carbonate EMC: Ethyl methyl carbonate DMC: Dimethyl carbonate GBL: γ-Butyrolactone PC: Propylene carbonate

Other additives BP: biphenyl CHB: cyclohexylbenzene TAB: t-amylbenzene

  As can be seen from the above results, according to the nonaqueous electrolytic solution of the present invention, it is understood that a high discharge capacity retention rate can be achieved even under severe use conditions with different temperature conditions while realizing high flame retardancy.

<Example 2>
The same operation as in Example 1 was performed except that the positive electrode active material was lithium manganate (LiMn ₂ O ₄ ) and the voltage at the cycle test charge was 4.2 V. As a result, the electrolytic solution of the present application obtained excellent results with a high capacity retention rate at low temperature / large current discharge even after the high temperature cycle test, whereas the electrolyte of the comparative example had a low temperature / high capacity at the time of cycle test charging. The capacity retention rate in current discharge was inferior. When the voltage at the time of cycle test charging was set to 4.3 V, the capacity retention rate at low temperature / large current discharge after the cycle test was lowered by using any of the electrolyte solutions of the examples and comparative examples. It was enough to meet practical requirements.
<Example 3>
The same operation as in Example 2 was performed except that the positive electrode active material was lithium cobalt oxide (LiCoO ₂ ) and the voltage at the cycle test charge was 4.0 V or 4.1 V. As a result, the electrolytic solution of the present application had an excellent result that the capacity retention ratio at low temperature / large current discharge was high even after the high temperature cycle test at any voltage of 4.0V and 4.1V. On the other hand, the electrolytic solution of the comparative example was equivalent to the electrolytic solution of the present application at the voltage 4.0 V during the cycle test charge, but the capacity at the low temperature / large current discharge after the cycle test at the voltage 4.1 V during the charge. The maintenance rate was inferior. When the voltage at the time of the cycle test was set to 4.2 V, the capacity retention rate at low temperature / high current discharge after the cycle test was lowered by using any of the electrolyte solutions of the example and the comparative example. It was enough to meet practical requirements.

<Example 4 and Comparative Example 2>
Preparation of electrolyte solution Compound (1) (2) was added to the electrolyte solution of Table 2 so that it might become the quantity shown in the table | surface, and also fluoroethylene carbonate was 1 mass% with respect to the total electrolyte solution, and succinonitrile was made into all. Electrolytic solutions for each test were prepared by adding 1% by mass to the electrolytic solution and 2% by mass of t-amylbenzene with respect to the total electrolytic solution. All the prepared electrolyte solutions had a viscosity at 25 ° C. of 5 mPa · s or less, and the water content measured by the Karl Fischer method (JIS K0113) was 20 ppm or less.
<Flame retardance>
The prepared electrolyte solution was evaluated for flame retardancy using the method of Example 1.
<Production of battery (2)>
The positive electrode is made of active material: nickel manganese lithium cobaltate (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ ) 85% by mass, conductive auxiliary agent: carbon black 7% by mass, binder: PVDF 8% by mass, The negative electrode was prepared with 94% by mass of active material: lithium titanate (Li ₄ Ti ₅ O ₁₂ ), conductive auxiliary agent: 3% by mass of carbon black, and binder: 3% by mass of PVDF. The separator is made of polypropylene and has a thickness of 25 μm. Using the positive and negative electrodes and the separator, a 2032 type coin battery (2) was produced.

<Battery initialization>
Charged at a constant current of 0.2 C until the battery voltage reaches 2.85 V (positive electrode potential 4.4 V) in a constant temperature bath at 30 ° C., and then charged until the battery voltage reaches a current value of 0.12 mA at a constant voltage of 2.85 V. Went. However, the upper limit of the time was 2 hours. Next, 0.2 C constant current discharge was performed in a thermostat at 30 ° C. until the battery voltage reached 1.2 V (positive electrode potential (2.75 V). This operation was repeated twice. The following items were evaluated using a 2032 type battery, and the results are shown in Table 2.
(First discharge capacity)
The battery was charged at a constant current of 1 C in a thermostat at 30 ° C. until the battery voltage reached 2.85 V, and then charged until the current value reached 0.12 mA at a constant voltage of the battery voltage of 2.85 V. However, the upper limit of the time was 2 hours. This battery was subjected to 1C constant current discharge in a thermostatic chamber at 30 ° C. until the battery voltage became 1.2 VV, and the initial 30 ° C./1C discharge capacity (IV) was measured.
(High temperature cycle test)
This battery was charged at a constant current of 1 C in a 45 ° C. thermostat until the battery voltage reached 2.85 V, and then charged at a constant voltage of 2.85 V until the current value was 0.12 mA. However, the upper limit of the time was 2 hours. A cycle in which 1C constant current discharge was performed on this battery in a 45 ° C. thermostat until the battery voltage reached 2.75 V was repeated 300 times.
(Discharge capacity after cycle test)
The battery after the high-temperature cycle test was charged and discharged under the same conditions as the initial discharge capacity measurement, and the discharge capacity (V) after the cycle test was measured.
(Low temperature, large current discharge capacity after cycle test)
The battery after the high-temperature cycle test was charged at a constant current of 1 C in a thermostatic chamber at 30 ° C. until the battery voltage reached 2.85 V, and then charged until the current value reached 0.12 mA at a constant voltage of the battery voltage of 2.85 V. It was. However, the upper limit of the time was 2 hours. This battery was subjected to 4C constant current discharge in a 10 ° C constant temperature bath until the battery voltage became 1.2V, and the 10 ° C / 4C discharge capacity (VI) after the cycle test was measured.

From the obtained results, the discharge capacity retention rate after the cycle test and the low temperature high current discharge capacity retention rate after the cycle test were calculated according to the following equations.
Discharge capacity maintenance ratio after cycle test = (V) / (IV)
Low-temperature, large-current discharge capacity retention ratio after cycle test = (VI) / (IV)

The obtained discharge capacity retention rate was evaluated as follows. The larger the value, the higher the capacity is maintained even under severe test conditions.
A: 0.8 or more B: 0.7 or more and less than 0.8 C: 0.6 or more and less than 0.7 D: 0.5 or more and less than 0.6 E: 0.3 or more and less than 0.5 F: 0. Less than 3

試験Ｎｏ．：ｃで始まるものが比較例
ｃｏｍｐ：例示化合物
ｃｏｎｃ：濃度（質量％）

Test No. : Starting with c is a comparative example comp: Exemplified compound conc: Concentration (mass%)

  By using the electrolytic solution of the present invention, it is possible to obtain an excellent effect that capacity deterioration can be suppressed even under severe conditions such as low temperature and large current discharge, and further a combustion suppression effect can be achieved. In particular, it can be seen that the secondary battery in which LTO suitable for large current discharge is applied to the negative electrode active material also shows good performance.

  In the above embodiment, the battery of the present invention exhibits excellent characteristics in combination with a lithium / titanium oxide negative electrode as a negative electrode, a carbon negative electrode, and nickel manganese lithium cobaltate, lithium manganate, lithium cobaltate as a positive electrode. Showed that. If the present invention is used, the same applies to a positive electrode used at a potential of 4.5 V or more, such as lithium nickel manganate, or a battery using a Si-containing negative electrode or a tin-containing negative electrode expected to have a higher capacity than a carbon negative electrode. It can be assumed that an excellent effect is exhibited.

  PN1 of Test 101 was converted to the above exemplary compounds (1-6), (1-10), (1-14), (1-22), (1-25), (1-30), (1-46) , (1-62) and (1-67), each test was carried out in the same manner except that each was replaced. As a result, it was confirmed that good performance was exhibited with respect to flame retardancy, durability at high temperatures and low temperature discharge properties.

  Each test was carried out in the same manner except that the compound 2-1-1 of Test 101 was replaced with the exemplified compounds a19, a24 and a27, respectively. As a result, it was confirmed that good performance was exhibited with respect to flame retardancy, durability at high temperatures and low temperature discharge properties.

  Each test was performed in the same manner except that the compound 2-2-1 in Test 104 was replaced with the exemplified compounds b7, b9, b10, and b18, respectively. As a result, it was confirmed that good performance was exhibited with respect to flame retardancy, durability at high temperatures and low temperature discharge properties.

  Each test was conducted in the same manner except that the compound 2-3-1 of Test 110 was replaced with the exemplified compounds c6 and c10, respectively. As a result, it was confirmed that good performance was exhibited with respect to durability at high temperatures and low temperature discharge properties.

C positive electrode (positive electrode composite)
1 Positive electrode conductive material (current collector)
2 Positive electrode active material layer A Negative electrode (negative electrode composite)
3 Negative electrode conductive material (current collector)
4 Negative electrode active material layer 5 Nonaqueous electrolyte 6 Operating means 7 Wiring 9 Separator 10 Lithium ion secondary battery 12 Separator 14 Positive electrode sheet 16 Negative electrode sheet 18 Exterior can 20 also serving as negative electrode Insulating plate 22 Sealing plate 24 Positive electrode current collector 26 Gasket 28 Pressure sensitive valve body 30 Current interrupting element 100 Bottomed cylindrical shape lithium secondary battery

Claims (12)

An electrolyte solution for a non-aqueous secondary battery containing a non-aqueous solvent, an electrolyte, a compound (I) below, and a compound (II) below.
(I) Compound represented by the following formula (1) (II) At least one compound selected from the following (2-1) to (2-3) (2-1) represented by the following formula (2-1) (2-2) Compound having alkyne structure (2-3) Cyclic ether compound

(In the formula, R ^{1 to} R ⁶ each represent a monovalent substituent. At least one of these substituents is —NR ^A R ^B , —N═R ^C , or an azide group, and at least one of the other substituents. Is a halogen atom, n represents an integer of 1 or more, and R ^A and R ^B are each independently a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, silyl group, or A substituent represented by the following formula (1A), (1B), (1C), or (1D) R ^C represents a substituent represented by any of the following formulas (C1) to (C6). .)

(In the formula, R ^1A1 , R ^1C1 , R ^1D1 and R ^1D2 represent an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a halogen atom, or an amino group. X ^A1 represents an oxygen atom or a sulfur atom. X ^D1 represents an oxygen atom, a sulfur atom, or a nitrogen ^{atom, X D1} is an oxygen atom, a sulfur ^{atom, R 1D3} is not a substituent ^{.X D1} is a nitrogen ^{atom, R 1D3} is an alkyl group, an aryl group, R ^1B1 and R ^{1B2 each} represents an alkyl group, an aryl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a phosphonyl group, or a silyl group, and * represents a bond. Represents hand.)

(Wherein R ^X1 , R ^X2 and R ^X3 represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a heterocyclic group, a halogen atom, or a silyl group. R ^Y1 and R ^Y2 Represents a halogen atom, and * represents a bond.)

(Ra ^{1 to} Ra ³ are independently an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, or — (CH ₂ ) _n C (═O) — (O) _m Rb ⁴ (n is 0 or 1, m represents 0 or 1, and Rb ⁴ represents an alkyl group, an alkenyl group, an aryl group, or an aralkyl group, and X represents an oxygen atom, a sulfur atom, or N (Ra ¹² ), and Ra ¹² represents a hydrogen atom. Or represents a monovalent substituent.) The electrolyte solution for a non-aqueous secondary battery according to claim 1, wherein the compound (2-2) is any one of the following formulas (2-2a) to (2-2g).

Rc ^{1 to} Rc ¹⁴ represent a hydrogen atom or a monovalent group. At least ^one of Rc ¹ and Rc ² , Rc ³ and Rc ⁴ , Rc ⁵ and Rc ⁶ , Rc ⁷ and Rc ⁸ , Rc ⁹ and Rc ¹⁰ , Rc ¹¹ and Rc ¹² , Rc ¹³ and Rc ¹⁴ is an alkyne structure have. Lc represents a hydrocarbon linking group. The electrolyte solution for non-aqueous secondary batteries according to claim 2, wherein the alkyne structure of the compound represented by any one of the compounds (2-2a) to (2-2g) is represented by the following structure (A1).

L ¹ represents a single bond, a hydrocarbon linking group, a hetero linking group, or a linking group obtained by combining these. L ² represents a hydrocarbon linking group, a hetero linking group, or a linking group obtained by combining these. nl is an integer of 0-10. R ²¹ represents an alkyl group, an aryl group, an aralkyl group, an amino group, a silyl group, or a hydrogen atom.   The electrolyte solution for a non-aqueous secondary battery according to claim 1, wherein the compound (2-3) is a 5- or 6-membered ring ether compound having 1 or 2 oxygen atoms in the ring. The electrolyte solution for a non-aqueous secondary battery according to claim 4, wherein the compound (2-3) is any one of the following formulas (B1) to (B5).

R ^{31 to} R ³⁶ each independently represents a substituent. n1 represents the integer of 0-8. n2 represents an integer of 0 to 6. n3 represents an integer of 0 to 10. n4 represents an integer of 0 to 8. n5 and n6 represent an integer of 0 to 5.   The electrolyte solution for nonaqueous secondary batteries according to any one of claims 1 to 5, wherein the compound (I) is contained in an amount of 0.1 to 20% by mass in the total amount of the electrolyte solution.   The electrolyte solution for nonaqueous secondary batteries according to any one of claims 1 to 5, wherein the compound (II) is contained in an amount of 0.01 to 10% by mass in the total amount of the electrolyte solution. In said Formula (1), all of R < ¹ > -R < ⁶ > is comprised with the halogen atom and the said specific nitrogen-containing group, Electrolysis for nonaqueous secondary batteries of any one of Claims 1-7 liquid.   The electrolyte solution for nonaqueous secondary batteries according to any one of claims 1 to 8, wherein the compound (II) is used in an amount of 10 to 100 parts by mass with respect to 100 parts by mass of the compound (I).   The non-aqueous secondary battery which has the electrolyte solution for non-aqueous secondary batteries of any one of Claims 1-9, a positive electrode, and a negative electrode.   The non-aqueous secondary battery according to claim 10, wherein the positive electrode active material is made of a material containing nickel and / or manganese.   The nonaqueous secondary battery according to claim 10 or 11, wherein the negative electrode active material is made of a material containing at least one selected from carbon, silicon, titanium, and tin.

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