JP6238411B2 - Non-aqueous secondary battery electrolyte and non-aqueous secondary battery - Google Patents

Description

  The present invention relates to an electrolyte for a non-aqueous secondary battery 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. In addition, there is a strong demand for small size, light weight, long life, and reliability. High reliability is required 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 these substances 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. 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 6).

JP 2005-190873 A International Publication No. 2010/101179 Pamphlet Japanese Patent No. 4458841 JP 2006-286571 A JP 2009-161559 A International Publication No. 2013/047342 Pamphlet

In recent years, it is necessary to achieve not only flame retardancy but also various battery performances, and there has been a demand for a battery in which deterioration of battery characteristics does not occur even when charging and discharging are repeated. Furthermore, it is desired to suitably cope with the use of high-potential batteries that are increasingly used.
The present invention has been made in view of such a situation, and an object thereof is to provide a nonaqueous electrolytic solution and a secondary battery that can improve flame retardancy while suppressing deterioration in battery performance. Moreover, it aims at provision of the electrolyte solution for non-aqueous secondary batteries and a secondary battery which adapt also to the use conditions of high electric potential, high temperature, and low temperature as needed, and show said outstanding performance.

式（Ｉ）中、Ｍ^ｍは中心金属であって、遷移元素または希土類元素を表す。
Ｒ^ｍ１はアルキル基、アルキルシリル基、アルケニル基、アルキニル基、アルコキシ基、アルキルチオ基、アミノ基、アミド基、アシルオキシ基、シアノ基、カルボキシル基、カルボニル基含有基、スルホニル基含有基、ホスフィノ基またはハロゲン原子を表す。複数のＲ^ｍ１が互いに連結して、脂肪族性または芳香族性の環を形成してもよい。
ａは０〜５の整数を表す。
Ｘ^ｍおよびＹ^ｍはそれぞれ独立に水素原子、アルキル基、アルケニル基、アルコキシ基、アルキルアミノ基、シリルアミノ基、スルホン酸基、イソシアネート基、イソチオシアネート基、−（Ｓ）ｎ−Ｒａ、ホスフィニル基、カルボニル基含有基、ハロゲン原子、アリール基またはヘテロアリール基を表す。ここで、Ｒａは水素原子または置換基を表し、ｎは１〜８の整数を表す。さらに、Ｘ^ｍとＹ^ｍが互いに連結して、Ｍ^ｍを含む環を形成してもよい。
ｍ１およびｎ１は０≦ｍ１＋ｎ１≦３を満たす整数である。ｃは０〜２の整数である。
Ｔ^１は水素原子、アルキル基、アルケニル基、アルコキシ基、アルキルアミノ基、シリルアミノ基、スルホン酸基、イソシアネート基、イソチオシアネート基、スルファニル基、ホスフィニル基、カルボニル基含有基、ハロゲン原子、アリール基、ヘテロアリール基、または上記式（ＣＰ）で表される基を表す。
式（ＣＰ）中、Ｒ^ｍ２はＲ^ｍ１と同義の基を表す。＊はＭ^ｍと結合する結合手を表す。ｂは０〜５の整数を表す。Ｒ^ｍ１とＲ^ｍ２は互いに連結していてもよい。
式（ＩＩ）中、Ｍ^ｍは中心金属であって、遷移元素または希土類元素を表す。
Ｒ^ｍ３およびＲ^ｍ４は水素原子、アルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基、アルキルシリル基またはハロゲン原子を表す。Ｒ^ｍ３とＲ^ｍ４は互いに連結していてもよい。
式（１）中、Ｍは中心金属を表す。
Ａ^１は芳香族環または芳香族複素環を表す。
Ｒ^１はアルキル基、アリール基、ヘテロアリール基またはアルケニル基を表す。Ｒ^１が複数ある場合、Ｒ^１は互いに結合もしくは縮合してもよく、複数のＲ^１で環を形成してもよい。
ＸはＣＲ^２または窒素原子を表す。ここで、Ｒ^２は水素原子、アルキル基、アルケニル基、水酸基、アルコキシ基、アリールオキシ基、メルカプト基、アルキルチオ基またはアリールチオ基を表す。Ｒ^１とＲ^２は互いに結合または縮合して環を形成してもよい。
Ｙは、水素原子、アルキル基、アルケニル基、アルコキシ基、アルキルアミノ基、シリルアミノ基、スルホン酸基、イソシアン酸基、イソチオシアン酸基、−Ｓ−Ｒａ、ホスフィニル基、カルボニル基含有基およびハロゲン原子から選択される１座の配位子を表す。ここで、Ｒａは水素原子または置換基を表す。
Ｒ^３は置換基を表す。
ｋは１〜４の整数を表す。ｌは０〜３の整数を表す。ｍは０〜２の整数を表す。
式（８’）中、Ｍ^ｏは中心金属であって、遷移元素または希土類元素を表す。
Ｒ^ｏはアルキル基、アルキルシリル基、アルケニル基、アルキニル基、アルコキシ基、アルキルチオ基、アミノ基、アミド基、アシルオキシ基、シアノ基、カルボキシル基、カルボニル基含有基、スルホニル基含有基、ホスフィノ基またはハロゲン原子を表す。Ｒ^ｏｏは水素原子またはＲ^ｏで規定される基を表す。複数のＲ^ｏは互いに異なっていてもよい。
ｎｏは１〜８の整数を表す。

式（Ａ１）、（Ａ２）中、Ｒａ ^１１ 〜Ｒａ ^１３ 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 ） _ｎ３ Ｃ（＝Ｏ）−（Ｏ） _ｍ３ Ｒｂ ^４ を表す。ｎ３は０または１を表す。ｍ３は０または１を表す。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を表す。Ｘ ^ｎ は酸素原子、硫黄原子またはＮ（Ｒａ ^１４ ）を表す。Ｒａ ^１４ は水素原子または１価の置換基を表す。Ｒａ ^２１ はそれぞれ独立に１価の置換基を表す。近接のＲ ^２１ は置換基同士が環を形成していてもよい。ｎ２は２以上の整数を表し、結合端同士が結合して環を形成してもよい。
〔２〕上記金属錯体（Ｂ）の中心金属が第４〜第８族遷移元素またはランタノイドである〔１〕に記載の非水二次電池用電解液。
〔３〕上記式（１）で表される化合物が下記式（２）〜（５）のいずれかで表される〔１〕または〔２〕に記載の非水二次電池用電解液。

式（２）〜（５）中、Ｍ、Ａ^１、Ｒ^３、Ｙ、ｋ、ｌおよびｍは上記式（１）における各定義と同じである。Ａ^２は上記式（１）におけるＡ^１と同義である。Ｂ^１およびＢ^２は含窒素芳香族複素環を表す。Ｒ^４〜Ｒ^６は上記式（１）におけるＲ^３と同義である。Ｒ^４とＲ^６は、互いに結合もしくは縮合してＢ^１およびＢ^２の一部とともに環を形成してもよい。Ｒ^７およびＲ^８は、それぞれ独立に、上記式（１）におけるＲ^２と同義である。Ｌはアルキレン基、アリーレン基、ヘテロアリーレン基またはアルケニレン基を表す。ｎ、ｏおよびｐは、それぞれ独立に、０〜３の整数を表す。
〔４〕上記式（Ａ２）で表される構造を有する化合物が下記式（Ａ２−１）または（Ａ２−２）で表される〔１〕〜〔３〕のいずれか１つに記載の非水二次電池用電解液。

式（Ａ２−１）、（Ａ２−２）中、Ｒａ^３１〜Ｒａ^３６、Ｒａ^４１〜Ｒａ^４８は、上記Ｒａ^２１と同義である。
〔５〕上記式（Ａ２−１）で表される構造を有する化合物が下記式（Ａ２−１−１）または（Ａ２−１−２）のいずれかで表される〔４〕に記載の非水二次電池用電解液。

式（Ａ２−１−１）、（Ａ２−１−２）中、Ｒａ^５１〜Ｒａ^５２はそれぞれ独立にアルコキシ基またはジアルキルアミノ基を表す。
〔６〕上記Ｒａ^５１〜Ｒａ^５２がジアルキルアミノ基である〔５〕に記載の非水二次電池用電解液。
〔７〕電解液が更に、芳香族性化合物、ハロゲン含有化合物、重合性化合物、硫黄含有化合物、ケイ素含有化合物、ニトリル化合物、ホウ素含有化合物およびイミド化合物から選ばれる少なくとも１種を含有する〔１〕〜〔６〕のいずれか１つに記載の非水二次電池用電解液。
〔８〕上記リン含有化合物（Ａ）の電解液（電解質を含む全量）中の濃度が０．５質量％以上３０質量％以下である〔１〕〜〔７〕のいずれか１つに記載の非水二次電池用電解液。
〔９〕上記金属錯体（Ｂ）の電解液（電解質を含む全量）中の濃度が０．００１質量％以上１０質量％以下である〔１〕〜〔８〕のいずれか１つに記載の非水二次電池用電解液。
〔１０〕上記リン含有化合物（Ａ）の含有量（１００質量部）に対して、上記金属錯体（Ｂ）の含有量が０．０１質量部以上１０質量部以下である〔１〕〜〔９〕のいずれか１つに記載の非水二次電池用電解液。
〔１１〕上記金属錯体（Ｂ）の中心金属が、Ｔｉ、Ｚｒ、ＨｆまたはＶである〔１〕〜〔１０〕のいずれか１つに記載の非水二次電池用電解液。
〔１２〕正極、負極および〔１〕〜〔１１〕のいずれか１つに記載の非水二次電池用電解液をそれぞれ具備する非水二次電池。
〔１３〕上記正極の活物質が、Ｎｉおよび／またはＭｎ原子を含有する〔１２〕に記載の非水二次電池。
〔１４〕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〔１２〕または〔１３〕に記載の非水二次電池。
The above problem has been solved by the following means.
[1] containing a nonaqueous solvent, an electrolyte, a phosphorus-containing compound (A) and a metal complex (B),
The metal complex (B) has a compound represented by the following formula (I) and a partial structure represented by the following formula (II), and the ligand coordinated to M ^m is only NR ^m3 R ^m4 . a compound, Ri compound der represented by a compound represented by or formula by the following formula (1) (8 '),
An electrolyte solution for a non-aqueous secondary battery, wherein the phosphorus-containing compound (A) is a compound represented by the following formula (A1) or a compound having a structure represented by the following formula (A2) .

In the formula (I), M ^m is a central metal and represents a transition element or a rare earth element.
R ^m1 represents an alkyl group, alkylsilyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, amino group, amide group, acyloxy group, cyano group, carboxyl group, carbonyl group-containing group, sulfonyl group-containing group, phosphino group or Represents a halogen atom. A plurality of R ^m1 may be connected to each other to form an aliphatic or aromatic ring.
a represents an integer of 0 to 5.
X ^m and Y ^m are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkylamino group, silylamino group, a sulfonic acid group, isocyanate group, isothiocyanate group, - (S) n-Ra , phosphinyl groups, A carbonyl group-containing group, a halogen atom, an aryl group or a heteroaryl group is represented. Here, Ra represents a hydrogen atom or a substituent, and n represents an integer of 1 to 8. In addition, ^{X m} and ^{Y m} are connected to each other, they may form a ring containing ^{M m.}
m1 and n1 are integers satisfying 0 ≦ m1 + n1 ≦ 3. c is an integer of 0-2.
T ¹ is a hydrogen atom, alkyl group, alkenyl group, alkoxy group, alkylamino group, silylamino group, sulfonic acid group, isocyanate group, isothiocyanate group, sulfanyl group, phosphinyl group, carbonyl group-containing group, halogen atom, aryl group, It represents a heteroaryl group or a group represented by the above formula (C P ).
In the formula (CP), R ^m2 represents a group having the same ^meaning as R ^m1 . * Represents a bond that bonds to M ^m . b represents an integer of 0 to 5. R ^m1 and R ^m2 may be connected to each other.
In the formula (II), M ^m is a central metal and represents a transition element or a rare earth element.
R ^m3 and R ^m4 represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkylsilyl group or a halogen atom. R ^m3 and R ^m4 may be connected to each other.
In formula (1), M represents a central metal.
A ¹ represents an aromatic ring or an aromatic heterocyclic ring.
R ¹ represents an alkyl group, an aryl group, a heteroaryl group or an alkenyl group. When there are a plurality of R ^{1 s} , R ¹ may be bonded or condensed to each other, and a plurality of R ¹ may form a ring.
X represents CR ² or a nitrogen atom. Here, R ² represents a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an aryloxy group, a mercapto group, an alkylthio group, or an arylthio group. R ¹ and R ² may be bonded to each other or condensed to form a ring.
Y represents a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkylamino group, a silylamino group, a sulfonic acid group, an isocyanic acid group, an isothiocyanic acid group, -S-Ra, a phosphinyl group, a carbonyl group-containing group and a halogen atom. Represents a selected monodentate ligand. Here, Ra represents a hydrogen atom or a substituent.
R ³ represents a substituent.
k represents an integer of 1 to 4. l represents an integer of 0 to 3. m represents an integer of 0-2.
In the formula (8 ′), ^Mo is a central metal and represents a transition element or a rare earth element.
R ^o is an alkyl group, alkylsilyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, amino group, amide group, acyloxy group, cyano group, carboxyl group, carbonyl group-containing group, sulfonyl group-containing group, phosphino group or Represents a halogen atom. R ^oo represents a hydrogen atom or a group defined by R ^o . A plurality of R ^o may be different from each other.
no represents an integer of 1 to 8.

Formula (A1), (A2) ^in, to Ra 11 ^{to Ra 13} independently, an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, or _{- (CH 2) n3 C (} = O) - (O) representing the _m3 Rb ^4. n3 represents 0 or 1. m3 represents 0 or 1. Rb ⁴ represents an alkyl group, an alkenyl group, an aryl group, or an aralkyl group. X ⁿ represents an oxygen atom, a sulfur atom, or N (Ra ¹⁴ ). Ra ¹⁴ represents a hydrogen atom or a monovalent substituent. Ra ²¹ each independently represents a monovalent substituent. In the adjacent R ^21, the substituents may form a ring. n2 represents an integer of 2 or more, and bond ends may be bonded to form a ring.
[2] The electrolyte solution for a non-aqueous secondary battery according to [1], wherein the central metal of the metal complex (B) is a Group 4 to Group 8 transition element or a lanthanoid.
[3] The electrolyte solution for a non-aqueous secondary battery according to [1] or [2], wherein the compound represented by the formula (1) is represented by any one of the following formulas (2) to (5).

In the formulas (2) to (5), M, A ¹ , R ³ , Y, k, l and m are the same as the definitions in the above formula (1). A ² has the same meaning as A ¹ in the above formula (1). B ¹ and B ² represent a nitrogen-containing aromatic heterocyclic ring. R ^{4 to} R ⁶ have the same meaning as R ³ in the above formula (1). R ⁴ and R ⁶ may be bonded to each other or condensed to form a ring together with a part of B ¹ and B ² . R ⁷ and R ⁸ are each independently synonymous with R ² in the above formula (1). L represents an alkylene group, an arylene group, a heteroarylene group or an alkenylene group. n, o and p each independently represent an integer of 0 to 3.
[ 4 ] The compound having the structure represented by the formula (A2) is represented by the following formula (A2-1) or (A2-2): [ 1] to [3] Electrolyte for water secondary battery.

In formulas (A2-1) and (A2-2), Ra ^{31 to} Ra ³⁶ and Ra ^{41 to} Ra ⁴⁸ have the same meaning as Ra ²¹ described above.
[5] Non-described compound having a structure represented by the above formula (A2-1) is the following formula (a2-1-1) or (a2-l-2) represented by any one of [4] Electrolyte for water secondary battery.

In formulas (A2-1-1) and (A2-1-2), Ra ^{51 to} Ra ⁵² each independently represents an alkoxy group or a dialkylamino group.
[6] a non-aqueous liquid electrolyte for a secondary battery according to the ^Ra 51 ^{to Ra 52} is an dialkylamino group [5].
[ 7 ] The electrolytic solution further contains at least one selected from an aromatic compound, a halogen-containing compound, a polymerizable compound, a sulfur-containing compound, a silicon-containing compound, a nitrile compound, a boron-containing compound and an imide compound [1] The electrolyte solution for non-aqueous secondary batteries as described in any one of-[ 6 ].
[ 8 ] The concentration of the phosphorus-containing compound (A) in the electrolyte solution (total amount including the electrolyte) is 0.5% by mass or more and 30% by mass or less, according to any one of [1] to [ 7 ] Electrolyte for non-aqueous secondary battery.
[ 9 ] The non-concentration according to any one of [1] to [ 8 ], wherein the concentration of the metal complex (B) in the electrolytic solution (total amount including the electrolyte) is 0.001% by mass or more and 10% by mass or less. Electrolyte for water secondary battery.
[10] The content of the phosphorus-containing compound (A) with respect to (100 parts by weight), is equal to or less than 10 parts by mass or more 0.01 part by weight content of the metal complex (B) [1] to [9 ] The electrolyte solution for non-aqueous secondary batteries as described in any one of.
[ 11 ] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [ 10 ], wherein the central metal of the metal complex (B) is Ti, Zr, Hf, or V.
[ 12 ] A nonaqueous secondary battery comprising the positive electrode, the negative electrode, and the electrolyte for a nonaqueous secondary battery according to any one of [1] to [ 11 ].
[ 13 ] The nonaqueous secondary battery according to [ 12 ], wherein the positive electrode active material contains Ni and / or Mn atoms.
[ 14 ] The nonaqueous secondary battery according to [ 12 ] or [ 13 ], wherein the negative electrode active material contains 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.

  The nonaqueous electrolytic solution of the present invention can suppress capacity deterioration during charging and discharging and improve flame retardancy in a secondary battery equipped with the same. Furthermore, if necessary, it is suitable for high potential and high / low temperature use conditions and exhibits the above-mentioned 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 electrolyte solution for a non-aqueous secondary battery of the present invention contains a phosphorus-containing compound and a metal complex. Hereinafter, it demonstrates in detail centering on preferable embodiment of this invention.

[Phosphorus-containing compound (A)]
Although there is no restriction | limiting in particular as a phosphorus containing compound (A), The compound which has at least 1 sort (s) chosen from PO bond, P = O bond, PN bond, and P = N is preferable. The phosphorus-containing compound (A) is preferably a compound represented by the following formula (A1) or a compound having a structure represented by the following formula (A2).
Therefore, in the present invention, a compound represented by the following formula (A1) or a compound having a structure represented by the following formula (A2) is used as the phosphorus-containing compound (A).

In (A1), Ra ^{11 to} Ra ¹³ are each independently an alkyl group, an aralkyl group, an alkoxy group, an aryloxy group, an aralkyloxy group, a halogen atom, an amino group, or — (CH ₂ ) _n3 C (═O). -(O) _m3 Rb ⁴ (n3 = 0 or 1, m3 = 0 or 1, Rb ⁴ is an alkyl group, an alkenyl group, an aryl group, or an aralkyl group).
X ⁿ represents an oxygen atom, a sulfur atom, or N (Ra ¹⁴ ). Ra ¹⁴ represents a hydrogen atom or a monovalent substituent.
The alkyl group in Ra ^{11 to} Ra ¹³ 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 aralkyl group is preferably an aralkyl group having 7 to 20 carbon atoms, and more preferably an aralkyl group having 7 to 11 carbon atoms. Specifically, in -Alk-Ar, Alk is preferably an alkylene group having 1 to 6 carbon atoms, and Ar is preferably an aryl group having 6 to 14 carbon atoms.
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.
The aralkyloxy group is preferably an aralkyloxy group having 7 to 20 carbon atoms, and more preferably an aralkyloxy group having 7 to 11 carbon atoms. Specifically, in -O-Alk-Ar, Alk is preferably an alkylene group having 1 to 6 carbon atoms, and Ar is preferably an aryl group having 6 to 14 carbon atoms.
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) n3 C (} = O) - The Rb ⁴ in _(O) m3 Rb ^4, alkyl group (1 to 12 carbon atoms, more preferably 1-6, particularly preferably 1 to 3), An alkenyl group (preferably 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms), an aryl group (preferably 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms, particularly preferably 6 to 10 carbon atoms), an aralkyl group (carbon number) 7-23 are preferable, 7-15 are more preferable, and 7-11 are particularly preferable), and a methyl group and an ethyl group are more preferable.
The monovalent substituent in Ra ¹⁴ is preferably an alkyl group (preferably having 1 to 6 carbon atoms), -S (= O) ₂ Ra ¹⁵ (Ra ¹⁵ 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 ¹⁶ ) ₂ (Ra ¹⁶ 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).
The above alkyl group, aralkyl group, alkoxy group, aralkyloxy group, aryloxy group, amino group, Rb ⁴ , Ra ¹⁴ , Ra ¹⁵ , Ra ¹⁶ may have a substituent T, particularly a halogen atom (fluorine It is preferable to have atoms.

In (A2), Ra ²¹ each independently represents a monovalent substituent. In the adjacent R ^21, the substituents may form a ring. n2 represents an integer of 2 or more, and bond ends may be bonded to form a ring. n2 is preferably 2 or more and 6 or less, and more preferably 3 or 4.
Ra ²¹ is a halogen atom (particularly preferably a fluorine atom), an alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 3), or an alkoxy group (having 1 to 12 carbon atoms). Preferably, 1-6 are more preferable, 1-3 are especially preferable, thioalkoxy group (C1-C12 is preferable, 1-6 are more preferable, and 1-3 are especially preferable), and an aryloxy group (carbon number). 6-22 are preferred, 6-14 are more preferred), arylthio groups (preferably 6-22 carbon atoms, more preferred 6-14), aralkyl groups (preferably 7-23 carbon atoms, more preferably 7-15). ), And an amino group (having preferably 0 to 6 carbon atoms, more preferably 0 to 3 carbon atoms).
Ra ²¹ is more preferably an alkoxy group, an aryloxy group, a halogen atom, or an amino group. As alkoxy groups, unsubstituted alkoxy groups such as methoxy group, ethoxy group, butoxy group, 2,2,2-trifluoroethoxy group, 1,1,1,3,3,3-hexafluoroisopropoxy group, perfluoro group A fluorine-substituted alkoxy group such as a butylethyl group is preferred.
The aryloxy group is preferably a phenoxy group or a fluorine-substituted phenoxy group.
When Ra ²¹ is an amino group, it is preferably shown as N (Ra ²³ ) ₂ . Ra ²³ is a monovalent substituent, preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms. The two Ra ²³ may be different from each other. Ra ²³ may be bonded to each other or condensed to form a ring. At this time, a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom may be incorporated. The ring to be formed is preferably a 5-membered ring or a 6-membered ring. The 5-membered ring is preferably a compound containing a nitrogen-containing 5-membered ring, such as pyrrole, imidazole, pyrazole, indazole, indole, benzimidazole, pyrrolidine, imidazolidine, pyrazolidine, indoline, carbazole, or derivatives thereof (all N substitution). Examples of the 6-membered ring include piperidine, morpholine, piperazine, and derivatives thereof (all are N-substituted).

The compound having a structure represented by the above formula (A2) is preferably a compound represented by the following formula (A2-1) or the following formula (A2-2).

Ra ^{31 to} Ra ³⁶ have the same meaning as Ra ²¹ , preferably 3 to 6 (preferably 4 or 5, more preferably 5) of Ra ³¹ to Ra ³⁶ are fluorine atoms, and 0 to 3 (Preferably 1 or 2, more preferably 1) is any of an alkoxy group, an aryloxy group, a halogen atom, and an amino group.

Ra ^{41 to} Ra ⁴⁸ have the same meaning as Ra ²¹ , and preferably 5 to 8 (preferably 6 or 7, more preferably 7) of Ra ⁴¹ to Ra ⁴⁸ are fluorine atoms, and 0 to 3 (Preferably 1 or 2 and more preferably 1) is an alkoxy group, an aryloxy group, a halogen atom or an amino group.

Ｒａ^５１〜Ｒａ^５２はそれぞれ独立にＲａ^２１と同義であり、好ましくはアルコキシ基（炭素数１〜１２が好ましく、１〜６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６〜１４が好ましい）、アルキル基（炭素数１〜６が好ましい）、ハロゲン原子、アミノ基（炭素数０〜１２が好ましく、２〜６がより好ましい）である。電解液への難燃性付与の観点から、Ｒａ^５１〜Ｒａ^５２はそれぞれ独立にアルコキシ基（炭素数１〜１２が好ましく、１〜６がより好ましく、１〜３が特に好ましい）、又はジアルキルアミノ基（炭素数２〜１２が好ましく、２〜６がより好ましい）が好ましく、ジアルキルアミノ基（炭素数２〜１２が好ましく、２〜６がより好ましい）がさらに好ましく、ジメチルアミノ基、ジエチルアミノ基、ジプロピルアミノ基、メチルエチルアミノ基、メチルプロピルアミノ基、エチルプロピルアミノ基が特に好ましい。 The compound having the structure represented by the above formula (A2-1) is preferably a compound represented by any one of the following formulas (A2-1-1) or (A2-1-2). -1) is particularly preferable.

Ra ⁵¹ to Ra ⁵² are each independently synonymous with Ra ²¹ , preferably an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms), an aryloxy group (carbon number). 6 to 14 are preferable), an alkyl group (preferably having 1 to 6 carbon atoms), a halogen atom, and an amino group (preferably having 0 to 12 carbon atoms and more preferably 2 to 6 carbon atoms). From the viewpoint of imparting flame retardancy to the electrolytic solution, Ra ⁵¹ to Ra ⁵² are each independently an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 and particularly preferably 1 to 3), or dialkylamino. Group (C2-C12 is preferable, C2-C6 is more preferable), dialkylamino group (C2-C12 is preferable, C2-C6 is more preferable) is more preferable, dimethylamino group, diethylamino group, A dipropylamino group, a methylethylamino group, a methylpropylamino group, and an ethylpropylamino group are particularly preferable.

Ra ¹¹ to Ra ¹⁶ , Ra ²¹ to Ra ²³ , Ra ^{31 to} Ra ³⁶ , Ra ^{41 to} Ra ⁴⁸ , Ra ^{51 to} Ra ⁵² , and Rb ⁴ present in plural in one molecule may be the same or different. It may be.

Preferred specific examples of the compound represented by the formula (A1) or (A2) are shown below (Ph is a phenyl group, Me is a methyl group, Et is an ethyl group, and Bu is a butyl group).

The said phosphorus containing compound may be used individually by 1 type, or may be used in combination of 2 or more type.
The concentration of the phosphorus-containing compound in the electrolyte solution for non-aqueous secondary batteries is not particularly limited, but the total amount including the electrolyte is preferably 0.5% by mass or more, and preferably 1% by mass or more. More preferred is 3% by mass or more. The upper limit is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less. By blending the phosphorus-containing compound at the lower limit value or more, sufficient flame retardancy can be imparted, and good charge / discharge properties can be realized in battery performance.

A commercially available phosphoric acid compound or phosphazene compound can be used, or it can be modified to obtain a compound having a desired structure. As a method of introducing a specific substituent into a phosphazene compound, for example, an alkoxy-substituted fluorinated phosphazene is a compound represented by (PNF ₂ ) _n and R-OM (wherein R is an alkyl group, M is An alcoholate represented by an alkali metal) or an alcohol represented by R—OH (wherein R is as defined above) is non-catalyzed or a basic catalyst such as sodium carbonate or potassium carbonate is present. The method of making it react below is proposed (Unexamined-Japanese-Patent No. 2009-161559, Unexamined-Japanese-Patent No. 2001-335590, Unexamined-Japanese-Patent No. 2001-139484, pamphlet of international publication 03/005479, special table 2001-516492). Issue gazette). As for the synthesis of a fluorinated phosphazene substituted with an amino group, a method of reacting a compound represented by (PNF ₂ ) _n with 2 equivalents of an amine (Journal of the Chemical Society [Section] A: Inorganic, Physical , Theoretical, 1970, p.2324-2329).

[Metal Complex (B)]
Metallic complexes refers other atoms to the metal atom or ion, molecule, chemical species ions are bound. Examples of the type of bond include a covalent bond, an ionic bond, and a coordination bond. Among these, at least selected from metal-carbon bonds (including metal-carbon π bonds such as alkene complexes and cyclopentadienyl complexes), metal-nitrogen bonds, metal-oxygen bonds, metal-sulfur bonds, and metal-phosphorus bonds. It is preferable to contain 1 type. In addition, it is preferable that at least one of other atoms, molecules, and ions (sometimes referred to as a ligand) bonded to a metal is an organometallic complex having a carbon atom.
In the present invention, the “center metal” includes a metal oxide as well as a metal element. Central metals include Group 4 transition elements (eg, Ti, Zr, Hf, etc.), Group 5 transition elements (eg, V, Nb, Ta, etc.), Group 6 transition elements (eg, Cr, Mo, etc.), Group 7 transition elements (eg, Mn, etc.), Group 8 transition elements (eg, Fe, Ru, etc.), Group 11 transition elements (eg, Cu, etc.), Group 12 transition elements (eg, Zn, etc.), etc. Is mentioned. Among them, the Group 4 to Group 8 transition elements are preferable, Ti, Zr, Hf, and V are more preferable, and Ti and Zr are most preferable. Specific examples of rare earth metal elements include lanthanoids (eg, Y, La, Ce, Sw, Nd, Lu, Er, Yb, Gd, etc.). Of these, Ce, Cd, and Er are preferable. As the non-transition metal, Al, Si, Sn , and Sb are preferable. Examples of the metal oxide include oxides of the metal elements exemplified above, and oxides of the metal elements exemplified in the preferred range are preferable.
Examples of the ligand that forms a metal-carbon bond include an alkyl group, an aralkyl group, an alkenyl group, and an aryl group. Examples of the ligand that forms a metal-carbon π bond include an alkene ligand, an allyl ligand, and a ligand having a cyclopentadienyl structure.
Metal - as ligands forming nitrogen bonds * -NR - * (R is a monovalent organic ^{group), * - N - - *} , * - C (= O) -N - - *, * - N = Ligand having a structure selected from * is fried (* is a bond). Nitrogen-containing heterocyclic structures such as a pyridine structure, an imidazole structure, and a phenanthroline structure are also preferable.
Examples of the ligand that forms a metal-oxygen bond include alkoxides, aryloxides, carbonyl groups, carboxylate groups, ether groups, and the like. Metal alkoxide, metal acetylacetonate complex, metal carboxylate complex and the like are preferable.
Examples of the ligand that forms a metal-sulfur bond include thiocarboxylate and thiolate.
A phosphine derivative is mentioned as a ligand which forms a metal- phosphorus bond.

  Specific examples of preferred ligands include ethylenediamine, propylenediamine, trimethylenediamine, diethylenetriamine, triethylenetetramine, pyridine, 2,2′-bipyridyl, 1,10-phenanthroline, imidazole, dimethylglyoximato, 1,2 -Bis (diphenylphosphino) ethane, 1,2-bis (diphenylphosphino) propane, oxalato, acetylacetonate, glycinato, alaninato, ethylenediaminetetraacetate, tetraphenylporphinelate, N, N'-disalicylideneethylenediamine , Cyclopentadienyl, pentamethylcyclopentadienyl, indanyl, 1,5-cyclooctadiene, norbornadiene and the like.

  The metal complex is preferably a metal metallocene, and more preferably represented by the following formula (I).

In the formula, M ^m represents a transition element or a rare earth element. Preferred transition elements are Group 4 to Group 8 transition elements or lanthanoids, and more preferably Group 4 to Group 6 transition elements or lanthanoids. Specifically, M ^m is preferably Fe, Ru, Cr, V, Ta, Mo, Ti, Zr, Hf, Y, La, Ce, Sw, Nd, Lu, Er, Yb, Gd, Ti, Zr, Hf, V, Nb, FeEr, and Gd are more preferable, and Ti, Zr, Hf, V, and Er are most preferable.

・ R ^m1
R ^m1 is an alkyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an alkylsilyl group (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an alkenyl group (preferably Has 2 to 6 carbon atoms, more preferably 2 or 3 carbon atoms, an alkynyl group (preferably 2 to 6 carbon atoms, more preferably 2 or 3 carbon atoms), an alkoxy group (preferably 1 to 6 carbon atoms, more Preferably 1 to 3 carbon atoms, an alkylthio group (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an amino group (preferably 0 to 6 carbon atoms, more preferably 1 to 4 carbon atoms). An amide group (carbamoyl group) (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an acyloxy group (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), a cyano group, Carboxyl Group, a carbonyl group-containing group (Ra-CO -) (preferably having from 2 to 7 carbon atoms, more preferably 2 to 4 carbon atoms), a sulfonyl group-containing group _(Ra-SO 2 -), a phosphino group _[PR 2 -: R represents a hydrogen atom or an alkyl group] (preferably 0 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), or a halogen atom. A plurality of R ^m1 may be connected to each other to form an aliphatic or aromatic ring.

Preferable examples of R ^m1 include the examples of substituent T described below within the range of the exemplified substituents. Among them, a methyl group, an n-butyl group, a t-butyl group, a trimethylsilyl group, a phosphino group (preferably having 2 to 6 carbon atoms, more preferably 2 or 3 carbon atoms), an alkylamino group (preferably having 2 to 2 carbon atoms). 6, more preferably 2 to 4 carbon atoms. In addition, said Ra represents a hydrogen atom or a substituent, The example of the postscript substituent T is mentioned as a preferable thing of a substituent. Among them, Ra is a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group), an alkoxy group (preferably having 1 to 6 carbon atoms, more preferably a methoxy group or an ethoxy group), amino Group (preferably having 0 to 6 carbon atoms, more preferably 2 to 4 carbon atoms), halogen atom (preferably fluorine atom), aryl group (preferably having 6 to 12 carbon atoms, more preferably phenyl group), perfluoro An alkyl group (preferably having 1 to 4 carbon atoms, more preferably a trifluoromethyl group) is preferred. The same applies to Ra. A plurality of R ^{m1 's} may be bonded to each other or condensed to form a ring.

・ A
a represents an integer of 0 to 5. Among these, 0 to 4 is preferable, and 0 or 1 is most preferable. When a is 2 or more, the plurality of groups defined therein may be the same as or different from each other.

・ X ^m , Y ^m
X ^m and Y ^m are each independently a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), and an alkenyl group (preferably having 2 to 6 carbon atoms, more preferably 2 carbon atoms). Or 3), an alkoxy group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an alkylamino group (preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), a silylamino group ( Preferably 0 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), sulfonic acid group, isocyanate group (NCO), isothiocyanate group (NCS), sulfanyl group (Ra- (S) n-) (preferably carbon 1 to 6, more preferably 1 to 3 carbon atoms, and n represents an integer of 1 to 8.), phosphinyl group ((Ra) ₂ (O =) P-) (preferably 0 to 10 carbon atoms, more Preferably charcoal Number 0 to 6), a carbonyl group-containing group (Ra-CO-) (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), a halogen atom, an aryl group (preferably 6 to 22 carbon atoms). , More preferably 6 to 10 carbon atoms) or a heteroaryl group (preferably 2 to 8 carbon atoms, more preferably 2 to 4 carbon atoms). X ^m and Y ^m may be bonded to each other or condensed to form a ring containing M ^m . For example, a plurality of sulfanyl groups may be bonded and coordinated as a cyclic polysulfide. Among them, methyl group, n- butyl group, a dialkylamino group, bis (trialkylsilyl) amino group, isothiocyanate (NCS) ^groups, X m, ^{Y m} cyclic alkenyl group containing M ^m which is condensed (butadiene Coordination type metallacycle) is preferred. X ^m and Y ^m may further have a substituent, and preferred examples thereof include the substituent T described later. Among these, a heterocyclic group, a halogen atom, a silyl group, an alkyl group, and the like are preferable.

・ M1, n1
m1 and n1 are integers satisfying 0 ≦ m1 + n1 ≦ 3. n1 + m1 is preferably 1 or more. When m1 and n1 are 2 or more, a plurality of groups defined therein may be the same as or different from each other.

・ T ¹
T ¹ is a hydrogen atom, an alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), and an alkenyl group (preferably having 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms). ), Alkoxy groups (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), alkylamino groups (preferably having 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms), silylamino groups (Preferably having 1 to 12 carbon atoms, more preferably 1 to 6), sulfonic acid group, isocyanate group (NCO), isothiocyanate group (NCS), sulfanyl group (SH), phosphinyl group, carbonyl group-containing group, halogen atom An aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms, particularly preferably 6 to 10 carbon atoms), a heteroaryl group (preferably having 1 to 12 carbon atoms, 2 to 5 are more preferable), or a group represented by the formula ( CP) . Among these, a hydrogen atom, a methyl group, an n-butyl group, an alkylamino group (preferably having 1 to 6 carbon atoms), or a group represented by the formula (CP) is preferable.

R ^m2 represents a group having the same ^meaning as R ^m1 . * Represents a bond bonded to the metal atom M. b represents an integer of 0 to 5. When b is 2 or more, the plurality of groups defined therein may be the same as or different from each other. R ^m2 may be linked to each other. Preferred examples of the ring formed by bonding or condensation of R ^m2 are the same as those for R ^m1 .

When T ¹ is an alkylamino group, an alkylamino group having 1 to 6 carbon atoms is preferable, and among them, a dimethylamino group and a diethylamino group are preferable.

  c is an integer of 0-2. When c is 2 or more, the plurality of groups defined therein may be the same as or different from each other.

  The above formula (I) is preferably represented by any of the following formulas (Icp-1) to (Icp-3).

式中、Ｍ^ｍ、Ｒ^ｍ１、Ｒ^ｍ２、ａ、ｂ、Ｘ^ｍ、Ｙ^ｍ、ｍ１、ｎ１は上記式（Ｉ）と同義である。

In the formula, M ^m , R ^m1 , R ^m2 , a, b, X ^m , Y ^m , m1, and n1 have the same meanings as the above formula (I).

  The above formulas (Icp-1) to (Icp-3) are preferably any of the following formulas (Ia-1) to (Ia-3), respectively.

In the formula, X ^m1 and Y ^m1 have the same ^{meanings as} X ^m and Y ^m and are preferably a methyl group, an n-butyl group, a bis (trimethylsilyl) amino group, and an isothiocyanate group, respectively. X ^m1 and Y ^m1 may be condensed to form a cyclic alkenyl group (butadiene coordinated metallacycle). M ^m , m 1 and n 1 have the same meaning as in formula (I).

  It is also preferable that the metal complex has a partial structure represented by the following formula (II).

M ^m -NR ^m3 R ^m4 ··· formula (II)

In the formula, M ^m represents a transition element or a rare earth element. The preferable thing is synonymous with the said formula (I).

R ^m3 and R ^m4 are a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), and an alkenyl group (preferably having 2 to 6 carbon atoms, more preferably 2 or 3 carbon atoms). , An alkynyl group (preferably having 2 to 6 carbon atoms, more preferably 2 or 3 carbon atoms), an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 10 carbon atoms), a heteroaryl group (preferably having carbon numbers) Represents 2 to 6, more preferably 2 to 4 carbon atoms), an alkylsilyl group (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), or a halogen atom. R ^m3 and R ^m4 may be connected to each other. R ^m3 and R ^m4 may be combined or condensed to form a ring. Preferable examples of R ^m3 and R ^m4 include the examples of the substituent T described later. Of these, a methyl group, an ethyl group, and a trimethylsilyl group are preferable.

  The formula (II) is preferably represented by the following formula (IIa).

M ^m- (NR ^m3 R ^m4 ) q Formula (IIa)

^{Wherein, M m, R m3, R} m4 has the same meaning as in formula (II). q 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 is 2 or more, the plurality of groups defined therein may be the same as or different from each other.

Although the specific example of the said metal complex is given to the following, this invention is limited to this and is not interpreted. TMS represents a trimethylsilyl group.

It is also preferable that the metal complex has a polydentate ligand having a structural part represented by the following formula (L). Here, the multidentate ligand is preferably a bidentate to tetradentate ligand.

* −E−A ¹ −X = N (R ¹ ) − * (L)

For A ^1, X, R ¹ of formula (L) is the same as that described in the section mentioned formula (1), which is also the same that preferred. * Indicates a bonding position with the central metal. E represents an oxygen atom or a sulfur atom.

  The specific metal complex is also preferably a compound represented by the following formula (1).

・ M
In formula (1), M represents a central metal. Specific examples of the transition element forming the central metal include a Group 4 transition element (eg, Ti, Zr, Hf, etc.), a Group 5 transition element (eg, V, Nb, Ta, etc.), and a Group 6 transition element. (Eg, Cr, Mo, etc.), Group 7 transition elements (eg, Mn, etc.), Group 8 transition elements (eg, Fe, Ru, etc.), Group 11 transition elements (eg, Cu, etc.), Group 12 Transition elements (for example, Zn etc.) etc. are mentioned. Among these, a Group 4 to Group 8 transition element is preferable, and Ti, Zr, Hf, V, and Cr are more preferable. Specific examples of rare earth metal elements include lanthanoids (eg, Y, La, Ce, Sw, Nd, Lu, Er, Yb, Gd, etc.). Of these, Ce, Gd, and Er are preferable. Examples of the metal oxide include oxides of the metal elements exemplified above, and oxides of the metal elements exemplified in the preferred range are preferable.
The central metal is more preferably a Group 4 to Group 8 transition element or a lanthanoid, and Ti, Zr, ZrO, Hf, HfO, V, Nb, NbO, Ta, Cr, Mo, MoO, Mn, Fe, Ru, Cu, Zn, Ce, Gd, Er are more preferable, Ti, Zr, ZrO, Hf, V, Cr, Fe, and Ce are particularly preferable, and Ti, Zr, Hf, V, and Cr are most preferable. .

・ A ¹
In formula (1), A ¹ represents an aromatic ring or an aromatic heterocyclic ring. The aromatic ring is preferably an aromatic ring having 6 to 14 carbon atoms, and specifically includes a benzene ring, a naphthalene ring, an anthracene ring, etc. Among them, a benzene ring is more preferable. The aromatic heterocycle is preferably an aromatic heterocycle having 2 to 12 carbon atoms, specifically, a pyrrole ring, a thiophene ring, a thiazole ring, an oxazole ring, a thiadiazole ring, an oxadiazole ring, an imidazole ring, a pyrazole ring, Examples include triazole ring, tetrazole ring, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzopyrazole ring, among them pyrazole ring, (imidazole ring, oxazole ring, Pyridine ring) is more preferable, and pyrazole ring is more preferable. A ¹ is preferably a benzene ring or a pyrazole ring, and more preferably a benzene ring.

ここで、＊はＸまたは酸素原子との結合手を表す。このとき、ピラゾール環又はベンゼン環は置換基Ｔを有していてもよい。 Preferred specific examples of A ¹ are shown below.

Here, * represents a bond with X or an oxygen atom. At this time, the pyrazole ring or the benzene ring may have a substituent T.

・ R ¹
In formula (1), R ¹ represents an alkyl group, an aryl group, a heteroaryl group, or an alkenyl group. The alkyl group may be a straight chain structure, a branched structure or a cyclic structure, and is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl, and the like. Among them, methyl and ethyl are preferable. Specific examples of the cycloalkyl group having 3 to 6 carbon atoms include cyclopropyl, cyclopentyl, cyclohexyl, etc. Among them, cyclohexyl is preferable. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, specifically, phenyl, naphthyl, anthracenyl, etc., among which phenyl is more preferable. The heteroaryl group is preferably a heteroaryl group having 1 to 12 carbon atoms. Specifically, in terms of the compound name constituting the ring, pyrrole, thiophene, thiazole, oxazole, thiadiazole, oxadiazole, imidazole, pyrazole, Examples include triazole, tetrazole, pyridine, pyrimidine, pyrazine, triazine, benzoxazole, benzothiazole, benzimidazole, and benzopyrazole, among which triazine and pyrazine are more preferable. The alkenyl group is preferably an alkenyl group having 2 to 6 carbon atoms, specifically, ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 1-pentenyl, 2-pentenyl, 1-hexenyl, 3-hexenyl and the like can be mentioned, among which ethenyl is more preferable. Each of the above groups may further have a substituent, an alkyl group (preferably methyl, ethyl, isopropyl, cyclohexyl), an alkoxy group (preferably methoxy, ethoxy), an aryl group (preferably phenyl), A halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom) may be mentioned. When there are a plurality of R ¹ in the molecule, R ¹ may be bonded or condensed to each other. At this time, a plurality of R ¹ may form a ring. R ¹ is preferably an alkyl group, an aryl group, or an alkenyl group, including a form in which R ¹ is bonded or condensed between adjacent ligands, and is a cycloalkyl group having 3 to 6 carbon atoms or a 6 to 14 carbon atoms. Are more preferable, and a cyclohexyl group, a phenyl group, and an ethenyl group are more preferable.

・ X
X represents CR ² or a nitrogen atom, and CR ² is preferable.

・ R ²
R ² represents a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an aryloxy group, a mercapto group ( thiol group ) , an alkylthio group, or an arylthio group. The alkyl group may be a straight chain structure, a branched structure or a cyclic structure, and is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl, and the like. Among them, methyl and ethyl are preferable. Specific examples of the cycloalkyl group having 3 to 6 carbon atoms include cyclopropyl, cyclopentyl, cyclohexyl, etc. Among them, cyclohexyl is preferable. The alkenyl group is preferably an alkenyl group having 2 to 6 carbon atoms, specifically, ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 1-pentenyl, 2-pentenyl, 1-hexenyl, 3-hexenyl and the like can be mentioned, among which ethenyl is more preferable. The alkoxy group is preferably an alkoxy group having 1 to 6 carbon atoms, and specifically includes methoxy, ethoxy, propyloxy, isopropyloxy, cyclohexyloxy, etc. Among them, methoxy and ethoxy are more preferable. The aryloxy group is preferably an aryloxy group having 6 to 14 carbon atoms, and specific examples include phenoxy and naphthoxy, with phenoxy being more preferable. The alkylthio group is preferably an alkylthio group having 1 to 6 carbon atoms, specifically, methylthio, ethylthio, propylthio, isopropylthio, butylthio, t-butylthio, pentylthio, hexylthio, etc., among which methylthio and ethylthio are preferable. . The arylthio group is preferably an arylthio group having 6 to 14 carbon atoms, and specifically includes phenylthio, naphthylthio, etc. Among them, phenylthio is more preferable. R ² is preferably a hydrogen atom, a hydroxyl group or a mercapto group, more preferably a hydrogen atom.

R ² may be bonded to or condensed with R ¹ to form a ring. The ring preferably forms a heterocycle and forms a nitrogen-containing aromatic heterocycle. Preferred rings formed are pyrrole ring, pyrazole ring, imidazole ring, thiazole ring, oxazole ring, thiadiazole ring, oxadiazole ring, triazole ring, tetrazole ring, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, benzoxazole A ring, a benzothiazole ring, a benzimidazole ring, a benzopyrazole ring, a quinoline ring and an isoquinoline ring, and more preferably a pyridine ring, a benzoxazole ring and a benzothiazole ring.

・ R ³
R ³ represents a substituent. R ³ is preferably an alkyl group, an alkoxy group, an aryl group, an alkenyl group, or a halogen atom, 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, or a carbon number 2 to 6 alkenyl groups are more preferable, and methyl, ethyl, propyl, isopropyl, isobutyl, t-butyl, perfluoromethyl, methoxy, phenyl and ethenyl are further preferable. Each of the above groups may further have a substituent, an alkyl group (preferably methyl, ethyl, isopropyl, cyclohexyl), an alkoxy group (preferably methoxy, ethoxy), an aryl group (preferably phenyl), A halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom) may be mentioned. When a plurality of R ³ are present, they may be bonded to each other or condensed to form a ring.

・ Y
Y represents a monodentate ligand. Specifically, Y is a hydrogen atom, an alkyl group (preferably 1 to 6 carbon atoms), an alkenyl group (preferably 2 to 6 carbon atoms), an alkoxy group (preferably 1 to 6 carbon atoms), Alkylamino groups (preferably having 2 to 10 carbon atoms), silylamino groups (preferably having 0 to 10 carbon atoms), sulfonic acid groups, isocyanate groups (NCO), isothiocyanate groups (NCS), sulfanyl groups (Ra- S-) (preferably 1 to 6 carbon atoms), phosphinyl group (RaO (Ra) PO-) (preferably 0 to 10 carbon atoms), carbonyl group-containing group (Ra-CO-) (preferably carbon Number 1-6), a halogen atom, an aryl group (preferably having 6 to 22 carbon atoms), or a heteroaryl group (preferably having 3 to 8 carbon atoms). Here, Ra represents an alkyl group (preferably having 1 to 6 carbon atoms). Y is preferably an alkyl group having 1 to 6 carbon atoms or a bis (trialkylsilyl) amino group, and more preferably a methyl group or a bis (trimethylsilyl) amino group.

・ K
k represents an integer of 1 to 4, and an integer of 2 to 4 is preferable. When k is 2 or more, the plurality of structural portions defined therein may be the same as or different from each other.

・ L
l represents an integer of 0 to 3, and an integer of 0 to 2 is preferable. When l is 2 or more, the plurality of structural portions defined therein may be the same as or different from each other.

・ M
m represents an integer of 0-2. When m is 2 or more, the plurality of structural portions defined therein may be the same as or different from each other.

式中、Ｍ、Ａ^１、Ｒ^３、Ｙ、ｋ、ｌ、およびｍは、式（１）における各定義と同じであり、好ましい範囲も同じである。 The formula (1) is preferably represented by any of the following formulas (2) to (5).

In the formula, M, A ¹ , R ³ , Y, k, l, and m are the same as the definitions in formula (1), and preferred ranges are also the same.

・ A ²
A ² has the same meaning as ^{A 1} in formula (1), and preferred ranges are also the same.

· ^B 1, ^{B 2}
B ¹ and B ² each independently represent a nitrogen-containing aromatic heterocycle. The nitrogen-containing aromatic heterocyclic ring may contain a hetero atom such as an oxygen atom or a sulfur atom in addition to the nitrogen atom in the ring structure. The nitrogen-containing aromatic heterocycle is preferably a nitrogen-containing aromatic heterocycle having 1 to 12 carbon atoms, specifically, a pyrrole ring, a pyrazole ring, an imidazole ring, a thiazole ring, an oxazole ring, a thiadiazole ring, or an oxadiazole ring. , Triazole ring, tetrazole ring, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzopyrazole ring, quinoline ring, isoquinoline ring, etc. A benzoxazole ring, a benzothiazole ring, and a quinoline ring are more preferable, and a pyridine ring is more preferable.

ここで、＊はＡ^１またはＡ^２との結合手、＃は中心金属との配位結合を示す。このとき、ピリジン環又はベンゼン環は置換基Ｔを有していてもよい。 Preferred specific examples of B ¹ and B ² are shown below.

Here, * indicates a bond with A ¹ or A ^2, and # indicates a coordinate bond with the central metal. At this time, the pyridine ring or the benzene ring may have a substituent T.

・ R ^{4 to} R ⁶
R ⁴ to R ⁶ has the same meaning as ^{R 3} in Formula (1), and preferred ranges are also the same. R ⁴ and R ⁶ may be bonded to each other or condensed to form a ring together with a part of B ¹ and B ² . The ring formed is preferably an aromatic ring and more preferably a benzene ring.

・ R ⁷ , R ⁸
R ⁷ and R ⁸ are each independently synonymous with R ² in Formula (1), and the preferred range is also the same.

・ L
L represents an alkylene group, an arylene group, a heteroarylene group, or an alkenylene group. The alkylene group may be a straight chain structure, a branched structure or a cyclic structure, and is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms or a cycloalkylene group having 3 to 6 carbon atoms. Specific examples of the alkylene group having 1 to 6 carbon atoms include methylene, ethylene, propylene, isopropylene, butylene, pentylene, hexylene and the like. Among these, methylene and ethylene are preferable. Specific examples of the cycloalkylene group having 3 to 6 carbon atoms include cyclopropylene, cyclopentylene, cyclohexylene and the like, and among them, cyclohexylene is preferable. The arylene group is preferably an arylene group having 6 to 14 carbon atoms, and specifically includes phenylene, naphthylene, anthracenylene, etc. Among them, phenylene is more preferable. The heteroaryl group is preferably a heteroarylene group having 1 to 12 carbon atoms. Specifically, a linking group having a structure in which two hydrogen atoms are removed from pyrrole, thiophene, thiazole, oxazole, imidazole, pyrazole, pyridine, pyrimidine, pyrazine, triazine, benzoxazole, benzothiazole, benzimidazole, and benzopyrazole. Among them, triazine and pyrazine are more preferable. The alkenylene group is preferably an alkenylene group having 2 to 6 carbon atoms, specifically, ethenylene, 1-propenylene, 2-propenylene, 1-butenylene, 2-butenylene, 1-pentenylene, 2-pentenylene, 1-hexenylene, Examples include 3-hexenylene, among which ethenylene is more preferable. Each of the above groups may further have a substituent, an alkyl group (preferably methyl, ethyl, isopropyl, cyclohexyl), an alkoxy group (preferably methoxy, ethoxy), an aryl group (preferably phenyl), A halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom) may be mentioned. L 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.

・ N, o, p
n, o, and p each independently represent an integer of 0 to 3, and an integer of 0 to 2 is preferable. When n, o, and p are 2 or more, the plurality of structural portions defined therein may be the same as or different from each other.

Formula (2) is preferably a compound represented by the following formula (2-1) or formula (2-2).

In formulas (2-1) and (2-2), M, B ¹ , R ³ , R ⁴ , Y, k, l, m, and n are the same as those defined in formula (2), and are preferable. The range is the same. R ³¹ is a hydrogen atom or a substituent of R ³ in formula (1). At this time, the preferred range of the substituent is also the same as the preferred substituent of R ³ above.

・ R ⁹
R ⁹ is 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 aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms), or A heteroaryl group (C1-C12 is preferable and 2-5 is more preferable) is represented. R ⁹ is preferably an alkyl group or an aryl group, and more preferably methyl or phenyl.

Formula (3) is preferably represented by the following formula (3-1) or formula (3-2).

In formula (3-1) and formula (3-2), M, B ¹ , B ² , R ³ , R ⁴ , R ⁵ , R ⁶ , Y, l, m, n, o, p are represented by the formula ( It is the same as each definition in 3), and a preferable range is also the same. R ⁹ and R ¹⁰ are each independently the same definition as R ⁹ in formula (2-2), and the preferred range is also the same. R ³¹ and R ⁵¹ are each independently the same definition as R ³¹ in Formula (2-2), and the preferred range is also the same.

式（４−１）、式（４−２）中、Ｍ、Ｒ^３、Ｒ^５、Ｒ^７、Ｒ^８、Ｌ、Ｙ、ｌ、ｍ、ｏは、式（４）における各定義と同じであり、好ましい範囲も同じである。Ｒ^９およびＲ^１０は、それぞれ独立に、式（２−２）におけるＲ^９と同じ定義であり、好ましい範囲も同じである。Ｒ^３１およびＲ^５１は、それぞれ独立に、式（２−２）におけるＲ^３１と同じ定義であり、好ましい範囲も同じである。 Formula (4) is preferably represented by the following formula (4-1) or formula (4-2).

In formula (4-1) and formula (4-2), M, R ³ , R ⁵ , R ⁷ , R ⁸ , L, Y, l, m, and o are the same as the definitions in formula (4). And the preferred range is also the same. R ⁹ and R ¹⁰ are each independently the same definition as R ⁹ in formula (2-2), and the preferred range is also the same. R ³¹ and R ⁵¹ are each independently the same definition as R ³¹ in Formula (2-2), and the preferred range is also the same.

式中、Ｍ、Ｒ^３、Ｒ^５、Ｒ^７、Ｒ^８、Ｌ、Ｙ、ｌ、ｍ、ｏは、式（５）における各定義と同じであり、好ましい範囲も同じである。Ｒ^９およびＲ^１０は、それぞれ独立に、式（２−２）におけるＲ^９と同じ定義であり、好ましい範囲も同じである。Ｒ^３１およびＲ^５１は、それぞれ独立に、式（２−２）におけるＲ^３１と同じ定義であり、好ましい範囲も同じである。 Formula (5) is preferably represented by the following formula (5-1) or formula (5-2).

In the formula, M, R ³ , R ⁵ , R ⁷ , R ⁸ , L, Y, 1, m, and o are the same as the definitions in formula (5), and the preferred ranges are also the same. R ⁹ and R ¹⁰ are each independently the same definition as R ⁹ in formula (2-2), and the preferred range is also the same. R ³¹ and R ⁵¹ are each independently the same definition as R ³¹ in Formula (2-2), and the preferred range is also the same.

Specific examples of the specific metal complex are listed below, but the present invention is not construed as being limited thereto.

The metallic complexes, metal as coordination bonds - having only oxygen bond (MO type complex) is also preferred. The MO complex is preferably a compound having a partial structure represented by the following formula (6).
^Mo- O (6)
^Mo is a transition element or a rare earth element. M ^o has the same meaning as M ^m described above. Zr, Ti, Hf, Al, and Fe are preferable, and Zr, Ti, and Al are more preferable.

Ｍ^ｏは上記と同義である。Ｒ^ｏはＲ^ｍ１と同義である。Ｒ^ｏは互いに連結していてもよい。連結してなる構造部は炭素数３〜１２のジエン構造であることが好ましく、例えばブタジエン構造が挙げられる。複数のＲ^Ｏは互いに異なっていてもよい。ｎｏは１〜８の整数であり、１〜４の整数が好ましい。 The formula (6) is preferably the following formula (7).

^Mo is as defined above. R ^o is synonymous with R ^m1 . R ^o may be linked to each other. The linked structure is preferably a diene structure having 3 to 12 carbon atoms, and examples thereof include a butadiene structure. The plurality of R ^O may be different from each other. no is an integer of 1 to 8, and an integer of 1 to 4 is preferable.

Ｍ^ｏ、ｎｏ、及びＲ^ｏは上記と同義である。複数のＲ^ｏは互いに異なっていてもよい。
以下に、配位結合として金属−酸素結合を有するもの（ＭＯ型錯体）の例を参考例とともに挙げるが、本発明がこれらに限定して解釈されるものではない。
The formula (7) is preferably the following formula (8).

M ^o , no, and R ^o are as defined above. A plurality of R ^o may be different from each other.
Although the example of what has a metal-oxygen bond (MO type complex) as a coordination bond is given with a reference example below, this invention is limited to these and is not interpreted.

The said metal complex may be used individually by 1 type, or may be used in combination of 2 or more type.
Here, the metal complex (B) used in the present invention has a compound represented by the above formula (I), a ligand having a partial structure represented by the above formula (II) and coordinated to M ^m Is a compound represented only by NR ^m3 R ^m4 , a compound represented by the above formula (1) or a compound represented by the following formula (8).
However, Y in the above formula (1) is a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkylamino group, a silylamino group, a sulfonic acid group, an isocyanic acid group, an isothiocyanic acid group, -S-Ra, a phosphinyl group, A monodentate ligand selected from a carbonyl group-containing group and a halogen atom. Here, Ra represents a hydrogen atom or a substituent.
In addition, the central R ^o in —OC (R ^o ) = C (R ^o ) C (R ^o ) = O... In the formula (8) is a hydrogen atom in addition to the group defined by R ^m1. Also good.

  In terms of the relationship with the phosphorus-containing compound, it is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and 0.1 parts by mass with respect to 100 parts by mass of the phosphorus-containing compound. Part or more is particularly preferable. The upper limit is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably 2 parts by mass or less. The metal complex functions to maintain the effect of improving the flame retardancy of the phosphorus-containing compound and suppress the influence on the battery performance. This is considered to be because the reaction product of the metal complex formed a specific film on the positive electrode, and the effect of suppressing the decomposition of the phosphorus-containing compound and the deterioration of the positive electrode was achieved. From that point of view, as described above, the desired effect can be obtained by applying a small amount of the metal complex with respect to the compounding amount of the phosphorus-containing compound.

(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 compounds>
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 compounds>
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, but 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>
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.

<Sulfur-containing compound>
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>
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>
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 examples 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.

<Boron-containing compound>
As the boron-containing compound, compounds represented by the following formulas (H1) to (H3) are preferable.

In the formula, R ^H1 and R ^{H4 to} R ^H11 are an alkyl group, an alkoxy group, an alkylcarbonyloxy group, an aryl group, an aryloxy group, an arylcarbonyloxy group, a heteroaryl group, a heteroaryloxy group, a heteroarylcarbonyloxy group, An alkylamino group, an arylamino group, a cyano group, a carbamoyl group, or a halogen atom may be represented and linked together to form a ring. R ^{H2 to} R ^H3 each independently represents an alkyl group, an alkylcarbonyl group, an aryl group, an arylcarbonyl group, a heteroaryl group, a heteroarylcarbonyl group, or a boron atom, and may be connected to each other to form a ring. Z ⁺ represents an inorganic or organic cation, and is preferably an ammonium cation, Li ⁺ , Na ⁺ , or K ⁺ . Specific examples of the boron-containing compound include the following structures, and more preferably Hex1 to Hex2.

<Imide compound>
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 the rupture of the battery at the time of abnormality due to overcharge, or to improve the capacity maintenance characteristic and cycle characteristic after high temperature storage.

The above exemplary compounds may have an arbitrary 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, 1-pyrrolyl, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzoimidazolyl, 2-thiazolyl, 2-oxazolyl, etc.), an alkoxy group (preferably an alkoxy having 1 to 20 carbon atoms) Groups such as methoxy, ethoxy, isopropyloxy, benzyloxy, etc., aryloxy groups (preferably aryloxy groups having 6 to 26 carbon atoms, such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxy Phenoxy and the like), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms) Including a alkoxy group, such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc., an amino group (preferably 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-phenylsulfa Moyl, etc.), acyl groups (preferably acyl groups having 1 to 20 carbon atoms such as acetyl, propionyl, butyryl, benzoyl etc.), acyloxy groups (preferably acyloxy groups having 1 to 20 carbon atoms, such as acetyloxy , Benzoyloxy, etc.), carbamoyl groups (preferably carbon atoms) A carbamoyl group having 1 to 20 carbon atoms such as N, N-dimethylcarbamoyl and N-phenylcarbamoyl), an acylamino group (preferably an acylamino group having 1 to 20 carbon atoms such as acetylamino and benzoylamino), sulfone An amide group (preferably a sulfamoyl group having 0 to 20 carbon atoms, such as methanesulfonamide, benzenesulfonamide, N-methylmethanesulfonamide, N-ethylbenzenesulfonamide, etc.), an alkylthio group (preferably having a carbon number of 1 to 20 alkylthio groups such as methylthio, ethylthio, isopropylthio, benzylthio, etc., arylthio groups (preferably arylthio groups having 6 to 26 carbon atoms such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphene) Ruthio, etc.), alkyl or arylsulfonyl groups (preferably alkyl or arylsulfonyl groups having 1 to 20 carbon atoms, such as methylsulfonyl, ethylsulfonyl, benzenesulfonyl, etc.), silyl groups (preferably alkyl having 1 to 20 carbon atoms) A silyl group, such as a trimethylsilyl group, a triethylsilyl group, a triphenylsilyl group, etc.), a hydroxyl group, a cyano group, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), more preferably an alkyl group , Alkenyl group, aryl group, heterocyclic group, alkoxy group, aryloxy group, alkoxycarbonyl group, amino group, acylamino group, hydroxyl group or halogen atom, particularly preferably alkyl group, alkenyl group, heterocyclic group, alkoxy group Base An alkoxycarbonyl group, an amino group, an acylamino group or a hydroxyl group.
In addition, each of the groups listed as the substituent T may be further substituted with the substituent T described above.

When the compound or substituent / linking group contains an alkyl group / alkylene group, alkenyl group / alkenylene group, etc., these may be cyclic or chain-like, and may be linear or branched, and substituted as described above. It may be substituted or unsubstituted. Moreover, when an aryl group, a heterocyclic group, etc. are included, they may be monocyclic or condensed and may be similarly substituted or unsubstituted.
[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 placed in 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 members, the separator 9 disposed between the positive electrode and the negative electrode, a current collecting terminal (not shown), an outer case, etc. ). 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 during 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. Examples of the transition metal oxide include specific transition metal oxides including those represented by any of the following formulas (MA) to (MC), or other transition metal oxides such as V ₂ O ₅ and MnO _2. 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 charge and discharge, 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, it is preferable to use a positive electrode active material containing Ni and / or Mn atoms, and it is more preferable to use a positive electrode active material containing both Ni and Mn atoms.
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 _0.5 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 high potential positive electrode. When a positive electrode with a high potential is used, the cycle characteristics tend to be greatly reduced. However, according to a preferred embodiment of the present invention, the nonaqueous electrolyte can maintain good performance with this decrease suppressed. .

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.
Moreover, as a metal complex oxide, what can occlude and discharge | release lithium is preferable, and it is preferable from a viewpoint of a high current density charge / discharge characteristic that it contains titanium and / or lithium as a structural component.

  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. Preferred examples of the amorphous oxide and chalcogenide _{include, 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 .

  The average particle size of the negative electrode active material 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.

  Examples of the negative electrode active material that can be used in combination with the amorphous oxide negative electrode active material centering on Sn, Si, and Ge include carbon materials that can occlude and release lithium ions or lithium metal, lithium, lithium alloys, lithium A metal that can be alloyed with is preferable.

The electrolyte solution 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, Excellent characteristics are exhibited in any combination with a potential of about 0.1 V 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 (Si), 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 large capacity charge / discharge. Under such conditions, the electrolyte solution for a non-aqueous secondary battery according to a preferred embodiment of the present invention is preferable because it exhibits excellent performance.

-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 current collector, an electron conductor that does not cause a chemical change is preferably 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.
The nonaqueous secondary battery of the present invention can be applied to various uses. 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, transceiver, 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.
<Example 1 and Comparative Example 1>
Preparation of Electrolytic Solution Compounds (A) and (B) were added to the solvents S1 to S3 of the electrolytic solution in Table A so as to have the amounts shown in Table 1, and vinylene carbonate was further added in an amount of 1% by mass based on the total electrolytic solution, An electrolyte solution for each test was prepared by adding t-amylbenzene at 1% by mass with respect to the total electrolyte solution and succinonitrile at 1% by mass with respect to the total electrolyte 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 flame retardancy of the prepared electrolyte was evaluated as follows at 25 ° C. in the atmosphere.
The evaluation was carried out under the following test conditions 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 off and suspended so that the minor axis was vertical. The butane gas burner adjusted to a total flame length of 2cm ignites for 3 seconds at the position where it touches the tip of the glass filter paper. The time to reach 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 ignited but immediately extinguished 3 ignited but extinguished before the flame reached from the ignition point to the other end 2 ... time for the flame to reach from the ignition point to the other end for 10 seconds In the above, although the combustion suppression effect is seen, it does not lead to incombustibility and flame extinction. Level 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 electrolytic solution shown in Table 1.

<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.
In addition, since the electrolyte viscosity becomes high in the low temperature environment, the movement of lithium ions is inhibited, the resistance becomes high, and the environment becomes severe when driving the battery.

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

  According to the nonaqueous electrolytic solution of the present invention, it is understood that a high discharge capacity maintenance rate can be achieved even under severe use 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>
The compounds (A) and (B) were added to the solvents S1 to S3 of the electrolytic solution of Table A so as to have the amounts shown in Table 2, and further 1% by mass of fluoroethylene carbonate with respect to the total electrolytic solution, t-amyl. Benzene was added at 1% by mass with respect to the total electrolytic solution, and succinonitrile was added at 1% by mass with respect to the total electrolytic solution to prepare electrolytic solutions for each test. 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.

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%)

  The same operation as in Example 1 was performed except that the negative electrode active material was lithium titanate (LTO) and the voltage at the cycle test charge was 2.85 V. The results are shown in Table 2. The electrolytic solution of the present application had an excellent result that the capacity retention rate at low temperature / large current discharge was high even after the high temperature cycle test.

<Example 5>
Preparation of Electrolytic Solution Compounds (A) and (B) were added to the solvents S1 to S3 of the electrolytic solution in Table A so as to have the amounts shown in Table 3, and vinylethylene carbonate was further added in an amount of 1% by mass with respect to the total electrolytic solution. , Except that ethylbenzene was added in an amount of 1.5% by mass with respect to the total electrolytic solution and diethylborylpyrazole dimer (Hex5) was added in an amount of 0.5% by mass with respect to the total electrolytic solution to prepare an electrolytic solution for each test. The same operation as in Example 1 was performed.

ｃｏｍｐ：例示化合物
ｃｏｎｃ：濃度（質量％）

comp: exemplary compound conc: concentration (mass%)

<Example 6>
Preparation of Electrolytic Solution Compounds (A) and (B) were added to the solvents S1 to S3 of the electrolytic solution in Table A so as to have the amounts shown in Table 4, and further fluoroethylene carbonate (Bex1) was added to the total electrolytic solution. 1% by mass, 1.5% by mass of cycloalkylbenzene with respect to the total electrolyte, and lithium tetracyanoborate (Hex11) at 0.5% by mass with respect to the total electrolyte, The same operation as in Example 1 was performed except for the preparation.

ｃｏｍｐ：例示化合物
ｃｏｎｃ：濃度（質量％）
上記実施例５、６の結果より機能性添加剤を配合した場合にも、本発明の非水二次電池用電解液は良好な性能を発揮することが分かる。

comp: exemplary compound conc: concentration (mass%)
It can be seen from the results of Examples 5 and 6 that even when a functional additive is blended, the electrolyte solution for a non-aqueous secondary battery of the present invention exhibits 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.

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 (14)

Containing a non-aqueous solvent, an electrolyte, a phosphorus-containing compound (A) and a metal complex (B),
The metal complex (B) has a compound represented by the following formula (I) and a partial structure represented by the following formula (II), and the ligand coordinated to M ^m is only NR ^m3 R ^m4 . a compound, Ri compound der represented by a compound represented by or formula by the following formula (1) (8 '),
An electrolyte solution for a nonaqueous secondary battery, wherein the phosphorus-containing compound (A) is a compound represented by the following formula (A1) or a compound having a structure represented by the following formula (A2) .

In the formula (I), M ^m is a central metal and represents a transition element or a rare earth element.
R ^m1 represents an alkyl group, alkylsilyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, amino group, amide group, acyloxy group, cyano group, carboxyl group, carbonyl group-containing group, sulfonyl group-containing group, phosphino group or Represents a halogen atom. A plurality of R ^m1 may be connected to each other to form an aliphatic or aromatic ring.
a represents an integer of 0 to 5.
X ^m and Y ^m are each independently a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkylamino group, silylamino group, a sulfonic acid group, isocyanate group, isothiocyanate group, - (S) n-Ra , phosphinyl groups, A carbonyl group-containing group, a halogen atom, an aryl group or a heteroaryl group is represented. Here, Ra represents a hydrogen atom or a substituent, and n represents an integer of 1 to 8. In addition, ^{X m} and ^{Y m} are connected to each other, they may form a ring containing ^{M m.}
m1 and n1 are integers satisfying 0 ≦ m1 + n1 ≦ 3. c is an integer of 0-2.
T ¹ is a hydrogen atom, alkyl group, alkenyl group, alkoxy group, alkylamino group, silylamino group, sulfonic acid group, isocyanate group, isothiocyanate group, sulfanyl group, phosphinyl group, carbonyl group-containing group, halogen atom, aryl group, It represents a heteroaryl group or a group represented by the above formula (C P ).
In the formula (CP), R ^m2 represents a group having the same ^meaning as R ^m1 . * Represents a bond that bonds to M ^m . b represents an integer of 0 to 5. R ^m1 and R ^m2 may be connected to each other.
In the formula (II), M ^m is a central metal and represents a transition element or a rare earth element.
R ^m3 and R ^m4 represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkylsilyl group or a halogen atom. R ^m3 and R ^m4 may be connected to each other.
In formula (1), M represents a central metal.
A ¹ represents an aromatic ring or an aromatic heterocyclic ring.
R ¹ represents an alkyl group, an aryl group, a heteroaryl group or an alkenyl group. When there are a plurality of R ^{1 s} , R ¹ may be bonded or condensed to each other, and a plurality of R ¹ may form a ring.
X represents CR ² or a nitrogen atom. Here, R ² represents a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an aryloxy group, a mercapto group, an alkylthio group, or an arylthio group. R ¹ and R ² may be bonded to each other or condensed to form a ring.
Y represents a hydrogen atom, an alkyl group, an alkenyl group, an alkoxy group, an alkylamino group, a silylamino group, a sulfonic acid group, an isocyanic acid group, an isothiocyanic acid group, -S-Ra, a phosphinyl group, a carbonyl group-containing group and a halogen atom. Represents a selected monodentate ligand. Here, Ra represents a hydrogen atom or a substituent.
R ³ represents a substituent.
k represents an integer of 1 to 4. l represents an integer of 0 to 3. m represents an integer of 0-2.
In the formula (8 ′), ^Mo is a central metal and represents a transition element or a rare earth element.
R ^o is an alkyl group, alkylsilyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, amino group, amide group, acyloxy group, cyano group, carboxyl group, carbonyl group-containing group, sulfonyl group-containing group, phosphino group or Represents a halogen atom. R ^oo represents a hydrogen atom or a group defined by R ^o . A plurality of R ^o may be different from each other.
no represents an integer of 1 to 8.

Formula (A1), (A2) ^in, to Ra 11 ^{to Ra 13} independently, an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, or _{- (CH 2) n3 C (} = O) - (O) representing the _m3 Rb ^4. n3 represents 0 or 1. m3 represents 0 or 1. Rb ⁴ represents an alkyl group, an alkenyl group, an aryl group, or an aralkyl group. X ⁿ represents an oxygen atom, a sulfur atom, or N (Ra ¹⁴ ). Ra ¹⁴ represents a hydrogen atom or a monovalent substituent. Ra ²¹ each independently represents a monovalent substituent. In the adjacent R ^21, the substituents may form a ring. n2 represents an integer of 2 or more, and bond ends may be bonded to form a ring.   The electrolyte solution for a non-aqueous secondary battery according to claim 1, wherein a central metal of the metal complex (B) is a Group 4 to Group 8 transition element or a lanthanoid. The electrolyte solution for non-aqueous secondary batteries according to claim 1 or 2, wherein the compound represented by the formula (1) is represented by any one of the following formulas (2) to (5).

In the formulas (2) to (5), M, A ¹ , R ³ , Y, k, l and m are the same as the definitions in the formula (1). A ² has the same meaning as A ¹ in the formula (1). B ¹ and B ² represent a nitrogen-containing aromatic heterocyclic ring. R ^{4 to} R ⁶ have the same meaning as R ³ in the formula (1). R ⁴ and R ⁶ may be bonded to each other or condensed to form a ring together with a part of B ¹ and B ² . R ⁷ and R ⁸ are each independently synonymous with R ² in the formula (1). L represents an alkylene group, an arylene group, a heteroarylene group or an alkenylene group. n, o and p each independently represent an integer of 0 to 3. The compound having a structure represented by the formula (A2) is represented by the following formula (A2-1) or (A2-2), for a non-aqueous secondary battery according to any one of claims 1 to 3 . Electrolytic solution.

In formulas (A2-1) and (A2-2), Ra ^{31 to} Ra ³⁶ and Ra ^{41 to} Ra ⁴⁸ have the same meaning as Ra ²¹ described above. The non-aqueous secondary according to claim 4 , wherein the compound having a structure represented by the formula (A2-1) is represented by any one of the following formulas (A2-1-1) or (A2-1-2). Battery electrolyte.

In formulas (A2-1-1) and (A2-1-2), Ra ^{51 to} Ra ⁵² each independently represents an alkoxy group or a dialkylamino group. The electrolyte solution for a non-aqueous secondary battery according to claim 5 , wherein the Ra ^{51 to} Ra ⁵² are dialkylamino groups. Electrolyte further aromatic compound, a halogen-containing compound, a polymerizable compound, a sulfur-containing compounds, silicon-containing compounds, nitrile compounds, according to claim 1 to 6 containing at least one selected from a boron-containing compound and imide compound The electrolyte solution for non-aqueous secondary batteries of any one of Claims. The nonaqueous secondary battery according to any one of claims 1 to 7 , wherein a concentration of the phosphorus-containing compound (A) in the electrolytic solution (total amount including the electrolyte) is 0.5 mass% or more and 30 mass% or less. Electrolyte. For a non-aqueous secondary battery according to any one of the metal complex (B) of the electrolytic solution according to claim concentration in (total volume including the electrolyte) is 10 wt% or less than 0.001 wt% 1-8 Electrolytic solution. The content of the phosphorus-containing compound (A) with respect to (100 parts by weight), claim 1-9 content is less than 10 parts by mass or more 0.01 part by weight of the metal complex (B) 1 The electrolyte solution for non-aqueous secondary batteries as described in the item. The central metal of the metal complex (B) is, Ti, Zr, non-aqueous liquid electrolyte for a secondary battery according to any one of claims 1 to 10, which is Hf or V. A nonaqueous secondary battery comprising the positive electrode, the negative electrode, and the electrolyte for a nonaqueous secondary battery according to any one of claims 1 to 11 . The nonaqueous secondary battery according to claim 12 , wherein the positive electrode active material contains Ni and / or Mn atoms. The nonaqueous secondary battery according to claim 12 or 13 , wherein the negative electrode active material contains at least one selected from carbon, silicon, titanium, and tin.

Images