WO2016027583A1

WO2016027583A1 - Electrolyte solution for nonaqueous secondary batteries, nonaqueous secondary battery, and additive used for electrolyte solution for nonaqueous secondary batteries

Info

Publication number: WO2016027583A1
Application number: PCT/JP2015/069655
Authority: WO
Inventors: 吉憲金澤; 郁雄木下
Original assignee: 富士フイルム株式会社
Priority date: 2014-08-22
Filing date: 2015-07-08
Publication date: 2016-02-25
Also published as: JP6376709B2; JPWO2016027583A1

Abstract

An electrolyte solution for nonaqueous secondary batteries, which contains more than 0% by mass but 1% by mass or less of an organic metal compound represented by formula (I); an additive for electrolyte solutions; and a nonaqueous secondary battery. In formula (I), M represents a metal element; each of R¹ and R² represents a substituent; if there are a plurality of R¹ moieties and a plurality of R² moieties, the plurality of R¹ moieties or the plurality of R² moieties may combine together to form an aliphatic or aromatic ring; each of X and Y represents a hydrogen atom or a substituent; if there are a plurality of X moieties and a plurality of Y moieties, the plurality of X moieties or the plurality of Y moieties may combine together to form a ring; L represents a linking group; each of a and b represents an integer of 0-4; and m and n represent integers satisfying 0 ≤ m + n ≤ 3.

Description

Non-aqueous secondary battery electrolyte and non-aqueous secondary battery, and additives used therefor

The present invention relates to an electrolyte for a non-aqueous secondary battery, a non-aqueous secondary battery using the same, and an additive used in these.

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. Recently, development of a secondary battery that is particularly lightweight and capable of obtaining a high energy density has been underway. Further, there is a demand for miniaturization and long life.

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. These substances have high conductivity and are stable in potential. It has been attempted to improve battery performance by further adding various functional additives to the electrolytic solution (see Patent Documents 1 to 5).

In addition, since the above carbonate-based solvent contains a combustible organic solvent compound as a component, it is important to impart flame retardancy from the viewpoint of reliability. For the purpose of this improvement, a technique for containing a phosphazene compound in an electrolytic solution has been proposed (see Patent Documents 6 to 11).

JP 2003-151621 A JP 2003-031259 A Japanese Patent No. 3787923 Special table 2008-538448 JP 2014-029827 A 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

Lithium ion secondary batteries have a wide variety of applications and are increasingly expanding. Therefore, further improvement in battery performance is desired, and in particular, improvement in cycle characteristics is desired. In addition, from the diversification of applications, a battery having higher reliability and better battery performance is desired.

An object of the present invention is to provide an electrolyte for a non-aqueous secondary battery that can improve cycle characteristics in a non-aqueous secondary battery, and an additive used therefor. Furthermore, an object of the present invention is to provide an electrolyte for a non-aqueous secondary battery that can improve cycle characteristics and improve flame retardancy, and an additive used therefor. It is another object of the present invention to provide a non-aqueous secondary battery using an electrolytic solution having such excellent characteristics.

The above problem has been solved by the following means.
(1) An electrolyte solution for a non-aqueous secondary battery containing an organometallic compound represented by the following formula (I), wherein the content of the organometallic compound is more than 0% by mass and 1% by mass or less.

In the formula (I), M represents a metal element.
R ¹ and R ² each independently represents a substituent. When there are a plurality of R ¹ and R ² , a plurality of R ¹ or a plurality of R ² may be bonded to each other to form an aliphatic or aromatic ring. X and Y each independently represent a hydrogen atom or a substituent. X and Y, or a plurality of Xs or Ys in the case where a plurality exist, may be bonded to each other to form a ring. L represents a linking group.
a and b each independently represents an integer of 0 to 4.
m and n represent integers satisfying 0 ≦ m + n ≦ 3.

(2) L includes a hydrocarbon group having 1 to 20 carbon atoms, a group containing a halogen atom, a group containing a silicon atom, a group containing a nitrogen atom, a group containing a phosphorus atom, a group containing a titanium atom, or a zirconium atom Electrolyte for non-aqueous secondary batteries as described in (1) which is group.
(3) R ¹ and R ² are each independently an alkyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, aryloxy group, amino group, group containing an amide bond, group containing an ester bond, cyano group , A carboxyl group, a group containing a carbonyl bond, a group containing a sulfonyl bond, a phosphino group, or a halogen atom, (1) or (2).
(4) X and Y are each independently a hydrogen atom, alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkylamino group, silylamino group, sulfo group, isocyanate group, isothiocyanate group, sulfanyl group, The electrolyte solution for a non-aqueous secondary battery according to any one of (1) to (3), which is a phosphinyl group, a group containing a carbonyl bond, a halogen atom, an aryl group, or a heteroaryl group.
(5) The electrolyte solution for a non-aqueous secondary battery according to any one of (1) to (4), wherein M is a Group 4 to Group 8 transition element.
(6) The electrolyte solution for a nonaqueous secondary battery according to any one of (1) to (5), wherein L is any one of groups represented by the following formulas (i) to (viii): .

In the formulas (i) to (viii), R ³ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylamino group, a silylamino group, a sulfo group, an isocyanate group, an isothiocyanate group, It represents a sulfanyl group, a phosphinyl group, a group containing a carbonyl bond, a halogen atom, an aryl group or a heteroaryl group. When R ³ is more present in the linking group, the plurality of R ³ may be the same even if different from each other. A plurality of R ³ may be bonded to each other to form a ring.

(7) The electrolyte solution for a non-aqueous secondary battery according to any one of (1) to (6), further comprising at least one phosphazene compound.
(8) The electrolyte solution for nonaqueous secondary batteries according to (7), wherein the phosphazene compound is represented by the following formula (A1) or (A2).

In the formulas (A1) and (A2), Ra ¹¹ to Ra ¹⁶ and Ra ²¹ to Ra ²⁸ each independently represent a monovalent substituent. The adjacent Ra ¹¹ to Ra ¹⁶ and Ra ²¹ to Ra ²⁸ may be bonded to each other to form a ring.
(9) The electrolyte solution for a non-aqueous secondary battery according to (8), wherein the compound represented by the formula (A1) is a fluorinated phosphazene compound represented by the following formula (A1-1).

In the formula (A1-1), Ra ⁴¹ represents an alkoxy group or a dialkylamino group.

(10) The electrolyte solution for nonaqueous secondary batteries according to (9), wherein Ra ⁴¹ is a dialkylamino group.
(11) A non-aqueous secondary battery comprising the positive electrode, the negative electrode, and the electrolyte solution for a non-aqueous secondary battery according to any one of (1) to (10).
(12) The additive used for the electrolyte solution for non-aqueous secondary batteries represented by the following formula (I).

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 to form a ring. In the case of a substituent on the ring, a plurality of substituents are bonded to form a ring, and the original ring And may form a condensed ring.
Further, in the present specification, when simply referred to as a substituent, the substituent T is referred to.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

The electrolyte solution for a non-aqueous secondary battery and the additive of the present invention can improve cycle characteristics in the non-aqueous secondary battery. Moreover, cycle characteristics can be improved and flame retardancy can be improved. Thereby, the non-aqueous secondary battery of the present invention exhibits excellent cycle characteristics and reliability as well as good battery performance.
The above and other features and advantages of the present invention will become more apparent from the following description, with reference where appropriate to the accompanying drawings.

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.

Hereinafter, the present invention will be described in detail.
In addition, description of the component requirement described below may be made | formed based on typical embodiment and a specific example. However, the present invention is not limited to such an embodiment.
The electrolyte solution for non-aqueous secondary batteries of the present invention (also referred to as electrolyte solution) contains an organometallic compound represented by the following formula (I). The additive (also referred to as an electrolyte additive) used in the electrolyte solution for non-aqueous secondary batteries of the present invention is an organometallic compound represented by the following formula (I).

[Organic metal compound of the present invention]

Hereinafter, each group in formula (I) and the organometallic compound of the present invention will be described in detail.

・ M
M represents a metal element. M is preferably a transition element or a rare earth element, more preferably a transition element of Group 4 to Group 8 or a lanthanoid, still more preferably a transition element of

Group

4, 5 or 8, and a group 4 or 8 Group transition elements are particularly preferred, and Group 8 transition elements are most preferred. Specifically, M is preferably Fe, Ru, Cr, V, Ta, Mo, Ti, Zr, Hf, Y, La, Ce, Sw, Nd, Lu, Er, Yb, Gd, and Ti, Zr, Hf, V, Nb, Fe, and Ru are more preferable, Ti, Zr, Fe, and V are more preferable, Ti, Zr, and Fe are particularly preferable, and Fe is most preferable.

・ R ¹ , R ²
R ¹ and R ² represent a substituent. Examples of these substituents include the substituent T described later. Here, among the substituents, a linear or branched substituent may be an aliphatic or aromatic ring or a group containing such a ring. Examples of such ring groups include hydrocarbon ring groups such as cycloalkyl groups, cycloalkenyl groups, cycloalkynyl groups, and aryl groups (eg, phenyl, naphthyl), and nitrogen-containing heterocycles. A heterocyclic group or a heteroaryl ring group (preferably a ring-constituting hetero atom is preferably an oxygen atom, a sulfur atom or a nitrogen atom, preferably a 5- or 6-membered ring group, and other ring (preferably a benzene ring or a hetero ring) ) May be condensed.).

R ¹ and R ² are preferably an alkyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an alkylsilyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms). ), An alkenyl group (preferably 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 carbon atoms) 1 to 6, more preferably 1 to 3 carbon atoms, an alkylthio group (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms), an aryloxy group (preferably 6 to 12 carbon atoms, more preferably Has 6 to 10 carbon atoms), an amino group (including an alkylamino group) (the carbon number is preferably 0 to 6, more preferably 1 to 6, still more preferably 2 to 6, and particularly preferably 2 to 4). Amide A group containing a group (a carbamoyl group, an acylamino group, a ureido group and a urethane group are preferred, a carbamoyl group and an acylamino group are more preferred. The number of carbon atoms is preferably 1 to 6, more preferably 1 to 3, more specifically, A group represented by C (═O) —N (Ra) ₂ , —N (Ra) —C (═O) Ra), a group containing an ester bond (acyloxy group or oxycarbonyl group is preferred, carbon The number is preferably 1 to 6, more preferably 1 to 4, and specifically, a group represented by —OC (═O) —Ra, —C (═O) —ORa is preferred), a cyano group, Carboxy group, group containing a carbonyl bond (acyl group is preferred, carbon number is preferably 2-7, more preferably 2-4, specifically, a group represented by —C (═O) —Ra is preferred. ), Including sulfonyl bonds (A sulfonyl group, a sulfonamido group, a sulfamoyl group are preferred, a sulfonyl group is more preferred. The number of carbon atoms is preferably from 1 to 6, more preferably 1 to 3, specifically, the group represented by -SO 2 _-Ra ), A phosphino group [—P (Rb) ₂ : Rb is a hydrogen atom or an alkyl group] (the carbon number is preferably 0 to 6, more preferably 1 to 6, still more preferably 1 to 3, and further preferably 2 or 3). Is particularly preferred) or a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.).
Here, Ra represents a hydrogen atom or a substituent, and examples of such a substituent include the substituent T described later. In the case of other than Ra as well, a preferable substituent of the “substituent” includes the substituent T described later.
When there are a plurality of R ¹ and R ² , a plurality of R ¹ or a plurality of R ² may be bonded to each other to form an aliphatic or aromatic ring. Examples of such a ring include an aliphatic or aromatic ring in the substituents for R ¹ and R ^2, and a ring or a cyclic group exemplified in a group containing such a ring.

R ¹ and R ² are preferably an alkyl group, an alkylsilyl group, a phosphino group, and an amino group, and particularly preferably an alkyl group. Specific preferred groups include a methyl group, an n-butyl group, a t-butyl group, a trimethylsilyl group, a dimethylphosphino group, a diethylphosphino group, a methylamino group, and an ethylamino group. Most preferred.

A and b each independently represents an integer of 0 to 4, preferably an integer of 0 to 3, and particularly preferably 0.

・ X, Y
X and Y each independently represent a hydrogen atom or a substituent. Examples of the substituent include the substituent T described later. X and Y are an alkyl group (preferably having 1 to 8 carbon atoms, more preferably 1 to 3 carbon atoms), an alkenyl group (preferably having 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), an alkynyl group ( Preferably 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), an alkoxy group (preferably 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms), an aryloxy group (preferably 6 to 12 carbon atoms). More preferably 6 to 10 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 carbon atoms). To 6), sulfo group, isocyanate group (—NCO), isothiocyanate group (—NCS), sulfanyl group (— (S) _α —Ra) (preferably having 1 to 6 carbon atoms, more preferably 1 carbon atom) -3, α represents an integer of 1-8, phosphinyl group (—P (═O) (Ra) ORa) (preferably having 0 to 10 carbon atoms, more preferably 0 to 6 carbon atoms), carbonyl bond (Preferably an acyl group, an acyloxy group or an oxycarbonyl group, more preferably an acyl group or an acyloxy group. The number of carbon atoms is preferably 1 to 6, more preferably 1 to 3. Specifically, — C (═O) —Ra, —O—C (═O) —Ra is preferred), a halogen atom, an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 10 carbon atoms), or hetero Aryl group (ring hetero atom is preferably oxygen atom, sulfur atom, nitrogen atom, ring member is preferably 5 or 6 member, and may be condensed with benzene ring or hetero ring. 2-4 are preferred There.) Is preferred.
Here, Ra represents a hydrogen atom or a substituent.

X and Y, or a plurality of Xs or Ys in the case where a plurality exist, may be bonded to each other to form a ring. Here, the ring formed when X and Y are bonded to each other is preferably a ring including an M atom.
Note that the bond forming the ring may be a single bond or a multiple bond. For example, a plurality of sulfanyl groups may be bonded and coordinated as a cyclic polysulfide. Among them, a methyl group, an n-butyl group, a dialkylamino group, a bis (trialkylsilyl) amino group, an isothiocyanate (—NCS) group, an alkoxy group, a phenoxy group, and a ring in which X and Y form a single bond to form a ring. An alkenyl group (butadiene coordination type metallacycle), a cyclic cumulene group in which a ring is formed by a double bond is preferable, an alkoxy group, a phenoxy group, and a cyclic alkenyl group in which X and Y form a ring by a single bond (butadiene coordination type) (Metallacycle), a cyclic cumulene group in which a ring is formed by a double bond is more preferable, a cyclic alkenyl group (butadiene-coordinated metallacycle) in which X and Y form a ring by a single bond, and a ring is formed by a double bond A cyclic cumulene group is particularly preferred.
X and Y may further have a substituent, and examples thereof include the following substituent T.

If X and Y are bonded to each other, ^{^{^{specifically, ** - C (R XY1)}}} = C (R XY2) -C (R XY3) = C (R XY4) - **, ** - C (R ^XY1 ) = C = C = C ( ^RXY4 )-**, **-C ( ^RXY1 ) ₂ -ethynylene-C ( ^RXY4 ) ₂ -** is preferable. Here, R ^XY1 to R ^XY4 each independently represents a hydrogen atom or a substituent, and ** represents a bonding point for bonding to M. R ^XY1 to R ^XY4 are preferably a hydrogen atom, an alkyl group, or a silyl group. In particular, R ^XY1 and R ^XY4 are preferably sterically bulky groups, and tertiary alkyl groups (preferably t-butyl groups) and silyl groups (preferably trialkylsilyl groups) are particularly preferable.

・ M, n
m and n are integers satisfying 0 ≦ m + n ≦ 3. m + n is preferably 2 or less. m = 1 and n = 1, or m + n = 0 is more preferable, and m + n = 0 is particularly preferable. When m and n are 2 or more, the plurality of groups defined therein may be the same as or different from each other.
In particular, when M is Fe, m + n = 0 is preferable, and when M is a metal element other than Fe, for example, Zr, V, and Ti, m = 1 and n = 1 are preferable.

・ L
L represents a linking group. As the linking group, a divalent hydrocarbon group having 1 to 20 carbon atoms, a group containing a halogen atom, a group containing a silicon atom, a group containing a nitrogen atom, a group containing a phosphorus atom, a group containing a titanium atom, or zirconium Groups containing atoms are preferred. A divalent hydrocarbon group having 1 to 20 carbon atoms, a group containing a silicon atom, a group containing a phosphorus atom, a group containing a titanium atom or a group containing a zirconium atom is more preferred, and a divalent group having 1 to 20 carbon atoms. More preferred are a hydrocarbon group, a group containing a silicon atom or a group containing a phosphorus atom, and a divalent hydrocarbon group having 1 to 20 carbon atoms and a group containing a silicon atom are particularly preferred.

L is preferably a group represented by any one of the following formulas (i) to (viii), and the formulas (i), (iii), (iv), (v), (vi), (vii), (viii) ) Is more preferred, and groups represented by formulas (i), (iii), (v), (vi), (vii), (viii) are more preferred, and formulas (i), (iii) ), (Vi), groups represented by (vii) are particularly preferred, and groups represented by formulas (i), (vi) are most preferred.
Here, the following * indicates the point of attachment to each of the two cyclopentadienyl rings.

Here, in the formula (vi) or (vii), the bond between Ti or Zr and R ³ may be a single bond, an ionic bond, or a coordination bond via a π electron, but may be coordinated via a π electron. A coordinate bond is preferred.

In the formulas (i) to (viii), R ³ is a hydrogen atom, an alkyl group (preferably having 1 to 8 carbon atoms, more preferably 1 to 3 carbon atoms), an alkenyl group (preferably having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), an alkynyl group (preferably 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms), an alkoxy group (preferably 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms), An aryloxy group (preferably having 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms), an alkylamino group (preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), a silylamino group (preferably carbon atoms) having 0 to 10, more preferably 2 to 6 carbon atoms), a sulfo group, an isocyanate group (-NCO), isothiocyanate group (-NCS), sulfanyl group _{(- (S) α -Ra)} ( preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, α represents an integer of 1 to 8), a phosphinyl group (—P (═O) (Ra) ORa) (preferably having 0 to 10 carbon atoms, More preferably, it has 0 to 6 carbon atoms, and a group containing a carbonyl bond (—C (═O) —Ra, —O—C (═O) —Ra) (preferably having 1 to 6 carbon atoms, more preferably carbon 1 to 3), a halogen atom, an aryl group (preferably 5 to 22 carbon atoms, more preferably 5 to 10 carbon atoms) or a heteroaryl group (the ring-forming hetero atom is preferably an oxygen atom, a sulfur atom, or a nitrogen atom) The number of ring members is preferably 5 or 6. The ring may be condensed with a benzene ring or a hetero ring, and the number of carbon atoms is preferably 2 to 8, more preferably 2 to 4.
The aryl group in R ³ includes an aryl ring, and the heteroaryl group includes a heteroaryl ring. Preferred ranges thereof are also the same as the aryl group and heteroaryl group, respectively. The aryl group herein includes a cyclopentadienyl group.
Here, Ra represents a hydrogen atom or a substituent.
Each group of R ³ may further have a substituent, and examples of such a substituent include the substituent T described later.
Among these, R ³ is preferably a hydrogen atom, an alkyl group, an aryl group, an aryl ring, an alkoxy group, an aryloxy group, a heteroaryl group or a heteroaryl ring, and a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a phenyl group, A methoxy group, an ethoxy group, an isopropoxy group, a phenoxy group, a cyclopentadienyl group, or a cyclopentadiene ring is more preferable.

A plurality of R ³ present in the linking group may be different from each other or the same. A plurality of R ³ may be bonded to each other to form a ring.

Specific examples of the organometallic compound represented by the general formula (I) of the present invention are given below. In addition, this invention is limited to these and is not interpreted.
Here, TMS is a trimethylsilyl group [—Si (CH ₃ ) ₃ ], t-Bu is a t-butyl group [—C ₄ H ₉ ^-t ], and Et is an ethyl group [—C ₂ H ₅ ].

The method for producing the organometallic compound represented by the general formula (I) of the present invention is not particularly limited. For example, International Publication No. 2009/066669, Organometallics, 1982, 1,1275-1282, 1984, 3, 1470-1478, 1999, 18, 2491-2496, J. Am. Am. Chem. Soc. , 1998, 120, 9533-9540, and the like.

The organometallic compound represented by the formula (I) of the present invention may be used alone or in combination of two or more.

Content in the electrolyte solution for non-aqueous secondary batteries of the organometallic compound represented by Formula (I) is more than 0 mass% and 1 mass% or less with respect to the whole quantity containing an electrolyte.
By making it in such a range, the effect of improving battery characteristics is effectively exhibited. In particular, 1% by mass or less is preferable because battery performance is not impaired.
The content of the organometallic compound represented by the formula (I) is preferably 0.001% by mass or more and 1% by mass or less, more preferably 0.005% by mass or more and 1% by mass or less, and still more preferably. Is preferably 0.01% by mass or more and 1% by mass or less, particularly preferably. It is 0.01 mass% or more and 0.5 mass% or less, Most preferably, it is 0.01 mass% or more and 0.2 mass% or less.

The organometallic compound represented by the formula (I) of the present invention crosslinks the cyclopentadiene ring of the metallocene, thereby giving distortion and destabilizing the compound itself, thereby oxidatively decomposing the metal compound of the present invention. Is promoted. As a result, even a battery with a low driving voltage could form a film on the positive electrode, and it seems that the cycle characteristics were greatly improved and the resistance was reduced.

In addition to the organometallic compound, the electrolyte for a non-aqueous secondary battery of the present invention preferably further contains a phosphazene compound.

[Phosphazene compounds]
The phosphazene compound used in the electrolyte solution for a non-aqueous secondary battery of the present invention is preferably a compound represented by the following formula (A1) or the following formula (A2).

In the formulas (A1) and (A2), Ra ¹¹ to Ra ¹⁶ and Ra ²¹ to Ra ²⁸ each independently represent a monovalent substituent. The adjacent Ra ¹¹ to Ra ¹⁶ and Ra ²¹ to Ra ²⁸ may be bonded to each other to form a ring.

Ra ¹¹ to Ra ¹⁶ and Ra ²¹ to Ra ²⁸ include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, particularly preferably a fluorine atom), an alkyl group (preferably having 1 to 12 carbon atoms, 1 to 6 are more preferable, and 1 to 3 are particularly preferable), an alkoxy group (including an alkoxy group substituted with an aryl group, an alkoxy group substituted with a fluorine atom, preferably having 1 to 12 carbon atoms, and preferably having 1 to 6 carbon atoms) More preferably, 1 to 3 is particularly preferable, an alkylthio group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 and particularly preferably 1 to 3), an aryloxy group (preferably having 6 to 22 carbon atoms, 6 To 14 are more preferred), an arylthio group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14 carbon atoms), an aralkyl group (preferably having 7 to 23 carbon atoms, To 15 is more preferable), an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14), an amino group (including an amino group substituted with an amino group, an alkyl group or an aryl group, and having 0 to 24 is preferable, 0 to 12 is more preferable, 0 to 6 is further preferable, and 0 to 3 is particularly preferable.) And an acylamino group (1 to 12 carbon atoms are preferable, 1 to 6 are more preferable, and 1 to 3 are particularly preferable) ).

Ra ¹¹ to Ra ¹⁶ and Ra ²¹ to Ra ²⁸ are preferably a halogen atom, an alkyl group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an aralkyl group or an amino group, and a halogen atom, an alkoxy group, an aryloxy group or An amino group is more preferable.
As the alkoxy group, an unsubstituted alkoxy group such as a methoxy group, an ethoxy group, or a butoxy group, or a 2,2,2-trifluoroethoxy group, a 1,1,1,3,3,3-hexafluoroisopropoxy group, An alkoxy group substituted with a fluorine atom such as a perfluorobutylethyl group is preferred. The aryloxy group is preferably a phenoxy group or a phenoxy group substituted with a fluorine atom.

In the compound represented by the formula (A1), 3 to 6 (preferably 4 or 5, more preferably 5) of Ra ¹¹ to Ra ¹⁶ are fluorine atoms, and 0 to 3 (preferably 1 Or two, more preferably one) is preferably an alkoxy group, an aryloxy group or an amino group.
In the compound represented by the formula (A2), 5 to 8 (preferably 6 or 7, more preferably 7) of Ra ²¹ to Ra ²⁸ are fluorine atoms, and 0 to 3 (preferably 1 Or two, more preferably one) is preferably an alkoxy group, an aryloxy group or an amino group.

The amino group in Ra ¹¹ to Ra ¹⁶ and Ra ²¹ to Ra ²⁸ preferably has a structure represented by the following formula (N1).

In the formula (N1), Ra ³¹ and Ra ³² are each independently a monovalent substituent, an alkyl group (preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, An alkyl group having 1 to 3 carbon atoms, an acyl group (an acyl group having 1 to 12 carbon atoms is preferable, an acyl group having 1 to 6 carbon atoms is more preferable, and an acyl group having 1 to 3 carbon atoms is particularly preferable) Or an aryl group (an aryl group having 6 to 22 carbon atoms is preferable, an aryl group having 6 to 14 carbon atoms is more preferable, and an aryl group having 6 to 10 carbon atoms is particularly preferable). Ra ³¹ and Ra ³² 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 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). Preferred examples of the 6-membered ring include piperidine, morpholine, piperazine, and derivatives thereof (all are N-substituted).

The compound represented by the above formula (A1) is preferably a fluorinated phosphazene compound represented by the following formula (A1-1) or the following formula (A1-2).

In the formulas (A1-1) and (A1-2), Ra ⁴¹ and Ra ⁴² have the same meaning as Ra ¹¹ and are preferably an alkoxy group, an aryloxy group, a fluorine atom or an amino group. From the viewpoint of imparting flame retardancy to the electrolytic solution, Ra ⁴¹ and Ra ⁴² are preferably an alkoxy group or a dialkylamino group, and more preferably a dialkylamino group.
As the dialkylamino group, an amino group represented by the above formula (N1) is preferably applied.

The phosphazene compound represented by the above formula (A1) is more preferably a fluorinated phosphazene compound represented by the above formula (A1-1) from the viewpoint of imparting flame retardancy to the electrolytic solution.

Preferred specific examples of the phosphazene compound used in the present invention are shown below, but the present invention is not construed as being limited thereto.

Me is a methyl group, Et is an ethyl group, Bu is a butyl group, and Ph is a phenyl group.

The phosphazene compounds used in the present invention may be used singly or in combination of two or more.
Further, the concentration of the phosphazene 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 phosphazene compound at the lower limit value or more, sufficient flame retardancy can be imparted, and good charge / discharge performance can be realized in battery performance.

As the phosphazene compound used in the present invention, a commercially available compound can be used, or a compound obtained by modifying it can be used.
As a method for introducing a specific substituent into the phosphazene compound, for example, a fluorinated phosphazene compound substituted with an alkoxy group is a fluorinated phosphazene compound represented by (PNF ₂ ) na (na represents 3 or 4). When, ^R-OM r (R is an alkyl group, ^{M r} in. which an alkali metal) alcoholate represented by, or an alcohol (R in which the alcoholate synonymous.) R-OH represented by the absence of a catalyst Or a method of reacting in the presence of a basic catalyst such as sodium carbonate or potassium carbonate (JP 2009-161559 A, JP 2001-335590 A, JP 2001-139854 A, (International Publication No. 03/005479 pamphlet, JP 2001-516492 A). Further, the method for the synthesis of fluorinated phosphazene compounds substituted by an amino group, is reacted with (PNF 2) fluorinated phosphazene compound represented by _na and (na represents 3 or 4.), 2 equivalents of an amine (Journal of the Chemical Society [Section] A: Inorganic, Physical, Theoretical, 1970, p. 2324-2329) is known.

(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 metal ion salt to be used 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 salt, etc.

(L-3) Oxalatoborate salt: lithium bis (oxalato) borate, lithium difluorooxalatoborate, etc.

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 ) are preferred, and lithium imides such as 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 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 such an amount that a preferable salt concentration described below in the method for preparing the electrolytic solution is obtained. It is preferable. The salt concentration is appropriately selected depending on the intended use of the electrolytic solution, but is generally 10% to 50% by mass, more preferably 15% 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 a density | concentration of ion, what is necessary is just to calculate by salt conversion with the metal applied suitably.

(Non-aqueous solvent)
As the non-aqueous solvent used in the present invention, an aprotic organic solvent is preferable, and an aprotic organic solvent having 2 to 10 carbon atoms is particularly preferable.
Such non-aqueous solvents include carbonate compounds, lactone compounds, chain or cyclic ether compounds, ester compounds, nitrile compounds, amide compounds, oxazolidinone compounds, nitro compounds, chain or cyclic sulfone or sulfoxide compounds, phosphoric acid. Examples include esters.
In addition, as a preferable bond, a compound having an ether bond, a carbonyl bond, an ester bond or a carbonate bond is preferable. These compounds may have a substituent, for example, the below-mentioned substituent T is mentioned.

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. 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, high viscosity (high dielectric constant) such as ethylene carbonate or propylene carbonate. A combination of a solvent (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. By using a mixed solvent of such a combination, the dissociation property of the electrolyte salt and the ion mobility are improved.
The nonaqueous solvent used in the present invention is not limited to these.

(Functional additives)
The electrolyte solution of the present invention preferably contains various functional additives in order to improve flame retardancy, improve cycle characteristics, improve capacity characteristics, and the like.
Examples of functional additives that are preferably applied to the electrolytic solution of the present invention are shown below.

<Aromatic compounds>
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. Preferred substituents are alkyl groups having 1 to 4 carbon atoms (for example, Methyl, ethyl, propyl, t-butyl, etc.) and aryl groups having 6 to 10 carbon atoms (eg, phenyl, naphthyl, etc.).
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, and specifically includes ethylbenzene, isopropylbenzene, cyclohexylbenzene, t-amylbenzene, t-butylbenzene, and tetrahydrohydronaphthalene. Can be mentioned.

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

<Polymerizable compound>
As the polymerizable compound, a compound having a carbon-carbon double bond is preferable. A carbonate compound having a double bond such as vinylene carbonate or vinyl ethylene carbonate, an acryloyloxy group, a methacryloyloxy group, a cyanoacryloyloxy group, α-CF ₃ A compound having a group selected from an acryloyloxy group and a compound having a styryl group are preferred, and a carbonate compound having a double bond or a compound having two or more polymerizable groups in the molecule is more preferred.

<Compound having a sulfur atom>
The compound having a sulfur atom is preferably a compound containing a sulfur atom and having a —SO ₂ —, —SO ₃ —, —OS (═O) O— bond, such as propane sultone, propene sultone, and ethylene sulfite. Cyclic sulfur-containing compounds and sulfonic acid esters are preferred.

As the sulfur-containing cyclic compound, a compound represented by the following formula (E1) or (E2) is preferable.

In the formulas (E1) and (E2), X ¹ and X ² each independently represent —O— or —C (Ra1) (Rb1) —. Here, Ra1 and Rb1 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.

<Compound having a silicon atom>
As the compound having a silicon atom, a compound represented by the following formula (F1) or (F2) is preferable.

In the formulas (F1) and (F2), 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 from each other or the same.

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

In the formula (G), 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. Preferred examples of each substituent can refer to the examples described in the corresponding group of the substituent T described later. Among them, a nitrile compound in which any one of R ^G1 to R ^G3 contains a cyano group can be used. preferable.

Ng represents an integer from 1 to 8.

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

<Compound having boron atom>
The compound having a boron atom is preferably a compound represented by the following formulas (H1) to (H3).

In the formulas (H1) to (H3), R ^H1 and R ^H4 to R ^H11 are each independently 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; Here, a plurality of groups may be bonded to each other to form a ring. R ^H2 and 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. Here, a plurality of groups may be bonded 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 compound having a boron atom include the following structures, more preferably Hex1, Hex2 or Hex10, and further preferably Hex10.

<Metal complex compound>
In this invention, you may contain the metal complex compound different from the organometallic compound represented by Formula (I) with the organometallic compound represented by Formula (I) of this invention.
As such a metal complex compound, a transition metal complex or a rare earth complex is preferable. Of these, complexes represented by any of the following formulas (H-1) to (H-3) are preferred.

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

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

M ^H — (NR ^1H R ^2H ) q ^H Formula (H-4)

In the formula (H-4), ^MH represents a transition element or a rare earth element, and is synonymous with the formulas (H-1) to (H-3), and the preferred range is also the same.

R ^1H and R ^2H are each a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms), an alkenyl group (preferably having 2 to 6 carbon atoms), an alkynyl group (preferably having 2 to 6 carbon atoms), an aryl group (preferably carbon atoms). The number represents 6 to 14), a heteroaryl group (preferably 3 to 6 carbon atoms), an alkylsilyl group (preferably 1 to 6 carbon atoms) or a halogen atom. R ^1H and R ^2H may be bonded to each other to form a ring. Such a ring is preferably a 5- to 6-membered ring, and examples thereof include a pyrrolidine ring, a piperidine ring, a piperazine ring, a morpholine ring, and a thiomorpholine ring. Preferable examples of R ^1H and R ^2H include examples of the substituent T described later. Of these, a methyl group, an ethyl group, and a trimethylsilyl group are preferable.
q ^H represents an integer of 1 to 4, preferably an integer of 2 to 4. More preferably, it is 2 or 4. When q ^H is 2 or more, where a plurality of groups as defined may be the same or different from each other.

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

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

・ R ^3h , R ^5h and R ^7h to R ^10h
R ^3h , R ^5h and R ^7h to R ^10h represent a substituent. Of these, an alkyl group, an alkoxy group, an aryl group, an alkenyl group, and a halogen atom are preferable. An alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and 2 carbon atoms. More preferred are alkenyl groups of 6 to 6 and methyl, ethyl, propyl, isopropyl, isobutyl, t-butyl, perfluoromethyl, methoxy, phenyl and ethenyl are further preferred.

・ R ^33h and R ^55h
R ^33h and R ^55h represent a hydrogen atom or a substituent of R ^3h . ^Examples of the substituent for R ^3h include the substituent T described later.

・ Y ^h
Y ^h 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.

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

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

<Imide compound>
As the imide compound, from the viewpoint of oxidation resistance, an imide compound in which all of the hydrogen atoms on the carbon atom are fluorinated is preferable, and a perfluorinated sulfonimide compound is preferable, specifically, perfluorinated. A sulfoimide lithium compound is mentioned.
Specific examples of the imide compound include the following structures, and Cex1 and Cex2 are more preferable.

The electrolytic solution of the present invention may contain at least one selected from the above, 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, and 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.

In addition, in the present specification, regarding the indication of a compound (for example, when referring to a compound with a suffix), in addition to the compound itself, when the compound has a dissociable group, it is used to mean its salt and its ion. .
In the present specification, a substituent that does not specify substitution / non-substitution (the same applies to a linking group) means that the group may have an arbitrary substituent. This is also synonymous for compounds that do not specify substitution / non-substitution. Preferred substituents include the following substituent T.

Examples of the substituent T include the following.
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl A group (preferably an alkenyl group having 2 to 20 carbon atoms such as vinyl, allyl, oleyl and the like), an alkynyl group (preferably an alkynyl group having 2 to 20 carbon atoms such as ethynyl, butynediynyl, phenylethynyl and the like), 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 2-chlorophenyl, 3-methylphenyl and the like), a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, preferably a 5- or 6-membered ring having at least one oxygen atom, sulfur atom or nitrogen atom) A heterocyclic group is preferable, for example, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl, etc., an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, 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-methoxyphenoxy, etc.) An alkoxycarbonyl group (preferably an alkoxy group having 2 to 20 carbon atoms) Bonyl groups such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl and the like, amino groups (preferably including amino groups having 0 to 20 carbon atoms, alkylamino groups and arylamino groups such as amino, N, N-dimethyl) Amino, N, N-diethylamino, N-ethylamino, anilino, etc.), sulfamoyl groups (preferably sulfamoyl groups having 0 to 20 carbon atoms, such as N, N-dimethylsulfamoyl, N-phenylsulfamoyl, etc.) ), An acyl group (preferably an acyl group having 1 to 20 carbon atoms, such as acetyl, propionyl, butyryl, benzoyl, etc.), an acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms, such as acetyloxy, benzoyl) Oxy and the like), a carbamoyl group (preferably having 1 to 20 carbon atoms) A carbamoyl group such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl, etc., an acylamino group (preferably an acylamino group having 1 to 20 carbon atoms such as acetylamino, benzoylamino, etc.), an alkylthio group (preferably carbon An alkylthio group having 1 to 20 atoms such as methylthio, ethylthio, isopropylthio, benzylthio, etc., an arylthio group (preferably an arylthio group having 6 to 26 carbon atoms such as phenylthio, 1-naphthylthio, 3-methylphenylthio) 4-methoxyphenylthio, etc.), an alkyl or arylsulfonyl group (preferably an alkyl or arylsulfonyl group having 1 to 20 carbon atoms, such as methylsulfonyl, ethylsulfonyl, benzenesulfonyl, etc.), a hydroxy group, Anomoto, halogen atom (e.g. fluorine atom, a chlorine atom, a bromine atom, an iodine atom) and the like.
Each group may be further substituted with the above-described substituent T. For example, an aralkyl group in which an aryl group is substituted for an alkyl group.

When a compound or a substituent / linking group includes an alkyl group / alkylene group, an alkenyl group / alkenylene group, an alkynyl group / alkynylene group, etc., these may be cyclic or linear, and may be linear or branched These may be substituted as described above or may be unsubstituted.

[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 effect of the invention is not hindered. Here, substantially not containing means that the concentration of water is 200 ppm (mass basis) or less, preferably 100 ppm or less, more preferably 20 ppm or less.
Actually, it is difficult to make it completely anhydrous, and 1 ppm or more is included.

<Viscosity of electrolyte>
The viscosity of the electrolytic solution of the present invention is not particularly limited. At 25 ° C., 10 to 0.1 mPa · s is preferable, and 5 to 0.5 mPa · s is more preferable.

The viscosity of the electrolytic solution is measured using 1 mL of a sample in a rheometer (for example, CLS 500 manufactured by TA Instruments) and using Steel Cone (for example, 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.

[Non-aqueous secondary battery]
The nonaqueous secondary battery of the present invention uses the above-described nonaqueous electrolyte of the present invention.
As a preferred embodiment of a non-aqueous secondary battery, a lithium ion secondary battery will be described with reference to FIG.
The lithium ion secondary battery 10 of the present 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 exchanges a and b are generated in the electrolytic solution 5, charging α and discharging β can be performed, and operation or storage 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 the case of 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 or 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 cycleability and high-temperature storage even for high-power and large-capacity batteries, as well as increase the heat dissipation efficiency during heat generation. Can be suppressed.

(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 mixture 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 negative electrode active materials.
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 such transition metal oxides 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 , MnO _2. Etc. 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 above-described 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. Further, it is more preferable that the molar ratio of Li / ^{M a} was synthesized were mixed so that 0.3 to 2.2.

[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 _aa M ¹ O _bb ... (MA)

In formula (MA), ^{M 1} are as defined above ^{M a,} and the preferred range is also the same. aa represents 0 to 1.2, preferably 0.1 to 1.15, more preferably 0.6 to 1.1. bb represents 1 to 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 formula (MA) typically has a layered rock salt structure.

The transition metal oxide is more preferably 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

In the formulas (MA-1) to (MA-7), g has the same meaning as the above aa, and the preferred range is also the same. j represents 0.1 to 0.9. i represents 0 to 1; However, 1-ji is 0 or more. k has the same meaning as the above bb, and the preferred range is also the same.
Specific examples of the transition metal compounds represented by the formulas (MA-1) to (MA-7) include LiCoO ₂ (lithium cobaltate [LCO]), LiNi ₂ O ₂ (lithium nickelate) LiNi _0.85 Co _0.1 Al _0.05 O ₂ (nickel cobalt lithium aluminum oxide [NCA]), LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (nickel manganese lithium cobalt oxide [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 expressed in different notations, 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)]
As the lithium-containing transition metal oxide, those represented by the following formula (MB) are particularly preferable.

Li _c M ² ₂ O _d (MB)

In the formula (MB), ^{M 2} are as defined above ^{M a,} and their preferable ranges are also the same. 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 represented by the following formulas.

(MB-1) Li _mm Mn ₂ O _nn
(MB-2) Li _mm Mn _p Al _2-p _Onn
(MB-3) Li _mm Mn _p Ni _2-p _Onn

In the formulas (MB-1) to (MB-3), mm is synonymous with c, and the preferred range is also the same. nn has the same meaning as d, and the preferred range is also the same. p represents 0-2. Specific examples of the transition metal compound include LiMn ₂ O ₄ and LiMn _1.5 Ni _0.5 O ₄ .

As the transition metal oxide represented by the formula (MB), those represented by the following are also preferable examples.

(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 the above, 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 (MC), e represents 0 to 2, preferably 0.1 to 1.15, and more preferably 0.5 to 1.5. f represents 1 to 5, preferably 0.5 to 2.

M ³ represents one or more elements selected from V, Ti, Cr, Mn, Fe, Co, Ni, and Cu. M ³ represents, 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.
In addition, said aa, c, g, mm, and e value showing the composition of Li are the values which change by charging / discharging, and are typically evaluated by the value of the stable state when Li is contained. In the formulas (a) to (e), the composition of Li is shown as a specific value, but this also varies depending on the operation of the battery.
In particular, in the present invention, a positive electrode active material containing Ni and / or Mn atoms is preferably used, and a positive electrode active material containing both Ni and Mn atoms is more preferably used.
Specific examples of particularly preferable positive electrode active materials include the following.

LiNi _0.33 Co _0.33 Mn _0.33 O ₂
LiNi _0.6 Co _0.2 Mn _0.2 O ₂
LiNi _0.5 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, it is preferable to use a positive electrode active material having a charging region capable of oxidizing the organometallic compound represented by the formula (I) of the present invention. Specifically, it is preferable to use a material that can maintain normal use at a positive electrode potential (Li / Li ⁺ reference) of 3.5 V or higher. The positive potential is more preferably 3.8 V or more, further preferably 3.9 V or more, and particularly preferably 4 V or more. In particular, the positive potential is preferably 4.1 V or higher, and most preferably 4.2 V or higher. The upper limit is not particularly limited. However, 5V or less is practical. By setting it as such a range, cycling characteristics and high-rate discharge characteristics can be improved.
Here, being able to maintain normal use means that the electrode material does not deteriorate and become unusable even when charged at that voltage, and this potential is also referred to as a normal usable potential.
The positive electrode potential (Li / Li ⁺ reference) at the time of charging / discharging is represented by the following formula.

(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 non-aqueous electrolyte 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 nonaqueous secondary battery of the present invention, the average particle diameter of the positive electrode active material used is not particularly limited, but is preferably 0.1 μm to 50 μm. The specific surface area is not particularly limited, but is preferably 0.01 m ² / g to 50 m 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.

In order to make the positive electrode active material have a predetermined particle size, a well-known grinder 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. You may use the positive electrode active material obtained by the baking method, after wash | cleaning with water, acidic aqueous solution, alkaline aqueous solution, and an organic solvent.

The blending amount of the positive electrode active material is not particularly limited, but is preferably 60 to 98% by mass, more preferably 70 to 95% by mass in 100% by mass of the solid component in the dispersion (mixture) for constituting the active material layer. preferable.

-Negative electrode active material As a negative electrode active material, what can insert and discharge | release lithium ion reversibly is preferable. There is no particular limitation as long as these conditions are satisfied. Examples thereof include carbonaceous materials, metal oxides such as tin oxide and silicon oxide, metal composite oxides, lithium alloys such as lithium alone and lithium aluminum alloys, and metals capable of forming an alloy with lithium such as Sn or Si.

These may be used alone or in any combination of two or more, and the ratio in this case may be any ratio. Among these, a carbonaceous material or a lithium composite oxide is preferable from the viewpoint of reliability.
The metal composite oxide is preferably one that can occlude and release lithium, and preferably contains titanium and / or lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics.

The carbonaceous material used as the negative electrode active material is a material substantially made of carbon. Examples thereof include carbonaceous materials obtained by firing artificial graphite such as petroleum pitch, natural graphite, and vapor-grown graphite, and various synthetic resins such as 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 may have an interplanar spacing, density, and crystallite size as described in JP-A-62-222066, JP-A-2-6856, and 3-45473. preferable. 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, and the like. It can also be used.

The metal oxide and metal composite oxide, which are negative electrode active materials used in the nonaqueous secondary battery of the present invention, preferably contain at least one of these. Among these metal oxides and metal composite oxides, amorphous oxides are 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 a peak in the region of 20 ° to 40 ° in terms of 2θ, and is a crystalline diffraction line. You may have. The strongest intensity of the 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 °. Is preferably 5 times or less, and particularly preferably has no crystalline diffraction line.

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

The average particle diameter 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.

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 includes carbon materials that can occlude and release lithium ions or lithium metal, lithium, lithium alloy, lithium, and the like. An alloyable metal is preferable.

The electrolytic 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 non-aqueous electrolyte 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.

-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 63-63)) , Etc.), etc.), metal fibers or polyphenylene derivatives (described in JP-A-59-20971) can be contained as one kind or a mixture thereof. Among these, the combined use of graphite and acetylene black is particularly preferable. The addition amount of the conductive agent is preferably 11 to 50% by mass, and more preferably 2 to 30% by mass. In the case of carbon black or graphite, 2 to 15% by mass is particularly preferable.

-Binder The binder (hereinafter also referred to as a binder) includes polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Among them, for example, starch, carboxymethylcellulose, cellulose, diacetylcellulose, Methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium alginate, polyacrylic acid, sodium polyacrylate, polyvinylphenol, polyvinylmethylether, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylonitrile, polyacrylamide, polyhydroxy (meth) acrylate, styrene-maleine Water-soluble polymers such as acid copolymers, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hex Safluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl (meth) acrylate, (Meth) acrylic acid ester copolymer containing (meth) acrylic acid ester such as 2-ethylhexyl acrylate, (meth) acrylic acid ester-acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate Polymer, Styrene-butadiene copolymer, Acrylonitrile-butadiene copolymer, Polybutadiene, Neoprene rubber, Fluoro rubber, Polyethylene oxide, Polyester polyurethane resin, Polyethylene Ether polyurethane resins, polycarbonate polyurethane 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. It is also preferable to use a styrene-butadiene copolymer as a binder and to use sodium carboxymethyl cellulose as a thickener.

Binders can be used alone or in combination of two or more. 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 non-aqueous 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. The addition amount of the filler is not particularly limited, but is preferably 0 to 30% by mass in the 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 copper alloy are more preferable.

As the shape of the current collector, a film sheet is usually used, but a net, a punched one, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like can also be used. The thickness of the current collector is not particularly limited. 1 μm to 500 μm is 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 shut-down function for ensuring reliability, that is, a function of closing a gap at 80 ° C. or higher to increase resistance and interrupting current, and the plugging temperature is preferably 90 ° C. or higher and 180 ° C. or lower. .

The shape of the separator holes is usually circular or elliptical, and the size is preferably 0.05 μm to 30 μm, more 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 preferably 20% to 90%, and more preferably 35% to 80%.

The polymer material may be a single material such as a cellulose nonwoven fabric, polyethylene, or polypropylene, or may be a material using two or more composite materials. 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.

As the inorganic substance, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used, 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. As 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 such an independent thin film shape, a separator formed by forming a composite porous layer containing 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 or paste 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 this embodiment, a cylindrical battery is taken as an example, but the present invention is not limited to this. For example, the positive and negative electrode sheets produced by the above method are overlapped with a separator and then processed into a sheet battery as it is, or after being folded and inserted into a rectangular can, the can and the sheet After the electrical connection, the electrolyte may be injected, and the opening may be sealed using a sealing plate to produce a square battery.

In any of the embodiments, 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 above 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.

A known method (for example, direct current or alternating current electric welding, laser welding, or ultrasonic welding) can be used for welding the cap, can, sheet, and lead plate. 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 non-aqueous 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 purposes and space. 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. Unless otherwise specified, parts and% are based on mass.

<Synthesis of Organometallic Compound I (2) of the Present Invention>
Organometallic compound I (2) was synthesized by the following synthesis scheme.

To a 500 ml three-necked flask, 36 g of cyclopentadienyl lithium (manufactured by Aldrich) and 300 ml of hexane were added. Next, after cooling to 0 ° C. with an ice bath, 32.5 g of dimethyldichlorosilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred at room temperature for 1 hour. After treatment with 4N aqueous hydrochloric acid, the residue was purified by distillation to obtain 28.7 g of dicyclopentadienyldimethylsilane.

To the 500 ml three-necked flask, 18.8 g of dicyclopentadienyldimethylsilane synthesized above and 120 ml of THF (tetrahydrofuran) were added. Next, after cooling to 0 ° C. in an ice bath, 125 ml of n-butyllithium (1.6 M: manufactured by Kanto Chemical Co., Inc.) was added dropwise, and the reaction solution was stirred at room temperature for 2 hours. Thereafter, a suspension obtained by adding 18.6 g of tetrachlorozirconium to 60 ml of a THF / toluene 1/1 solution was added dropwise to the reaction solution at 0 ° C. After reacting at room temperature for 2 hours, the mixture was concentrated and extracted with chloroform: 500 ml. The mixture was cooled to −20 ° C. with a methanol-ice bath, and the precipitated recrystallized product was separated by filtration to obtain 12.55 g of Compound X (1).

In a 200 ml three-necked flask, 5.77 g of 4,4-dimethyl-2-pentyne (Alfa Aesar) was mixed with 40 ml of THF. Next, after cooling to −70 ° C. or lower with a dry ice-methanol bath, 10.45 g of X (1) was added. After confirming cooling at −70 ° C. or lower, 37.5 ml of n-butyllithium (1.6M, manufactured by Kanto Chemical Co., Inc.) was added dropwise, and the reaction solution was stirred for 1 hour after the completion of the dropwise addition. Next, the reaction solution was warmed to room temperature and further reacted for 2 hours. The reaction solution was concentrated, 40 ml of toluene was added, and the mixture was stirred for 5 minutes. The obtained suspension was filtered through Celite, and then toluene was distilled off again with an evaporator. The obtained crude product is dissolved in 200 ml of hexane, cooled to −70 ° C. or lower with a dry ice-methanol bath, the precipitated recrystallized product is filtered off, and the organometallic compound I (2) of the present invention: 9.1 g was obtained.

<Synthesis of Organometallic Compound I (4) of the Present Invention>
Organometallic compound I (4) was synthesized by the following synthesis scheme.

Compound X (1): 10.45 g and dehydrated toluene: 100 ml were added to a 200 ml three-necked flask. Next, after cooling to −70 ° C. or less with a dry ice-methanol bath, 37.5 ml of n-butyllithium (1.6M: manufactured by Kanto Chemical Co., Inc.) was added dropwise over 30 minutes. Stir. 2,2,7,7-Tetramethylocta-3,5-diyne: 4.87 g (manufactured by ALDRICH) was added, and the reaction solution was warmed to room temperature and further reacted for 3 hours. After completion of the reaction, 200 ml of water was added, and the mixture was extracted with diethyl ether. The extract was washed with water and brine and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the resulting crude product was dissolved in 200 ml of hexane, cooled to −70 ° C. or lower with a dry ice-methanol bath, and the precipitated recrystallized product was filtered off to obtain the organic of the present invention. Metal compound I (4): 8.2g was obtained.

<Synthesis of Organometallic Compound I (7) of the Present Invention>
Organometallic compound I (7) was synthesized according to the following synthesis scheme.

To a 500 ml three-necked flask, ferrocene: 30 g (manufactured by Tokyo Chemical Industry Co., Ltd.) and hexane: 200 ml were added. After cooling to 0 ° C. in an ice bath, 160 ml of n-butyllithium (2.3 M: manufactured by Kanto Chemical Co.) was added dropwise, and then 30 ml of tetramethylethylenediamine (manufactured by Aldrich) was added dropwise, and the reaction solution was allowed to rise to room temperature. Warmed and allowed to react for another 5 hours. The precipitate was filtered, washed with hexane, and dried to obtain 44.9 g of Compound X (2).

Compound X (2): 5.03 g and dehydrated diethyl ether: 100 ml (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a 200 ml three-necked flask. Next, after cooling to −70 ° C. or lower with a dry ice-methanol bath, 2.4 ml of dimethyldichlorosilane (manufactured by Tokyo Chemical Industry Co., Ltd.) is added dropwise over 10 minutes, and the reaction solution is warmed to room temperature and heated for 10 hours. Reacted. The reaction solution was concentrated, 100 ml of hexane was added, the suspension was filtered, and then concentrated again. The obtained crude crystals were purified by sublimation to obtain 2.2 g of the organometallic compound I (7) of the present invention.

<Synthesis of Organometallic Compound I (8) of the Present Invention>
Organometallic compound I (8) was synthesized by the following synthesis scheme.

Compound X (2): 6.0 g and dehydrated hexane: 200 ml (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a 500 ml three-necked flask. Next, after cooling to −70 ° C. or less with a dry ice-methanol bath, a solution of dichlorophenylphosphine: 2.58 ml of hexane: 25 ml was added dropwise over 20 minutes. After dropping, the reaction solution was warmed to room temperature and reacted for 10 hours.
After quenching by adding 5 ml of saturated aqueous ammonium chloride solution to the reaction solution, the aqueous layer was removed and concentrated. Next, the residue was extracted four times with 50 ml of hexane, about 180 ml of this hexane extract solution was concentrated and removed, and recrystallized at −30 ° C. to obtain 1.9 g of the organometallic compound I (8) of the present invention. .

<Synthesis of other organometallic compounds>
Organometallic compounds I (1), (9) to (12) and (14) were synthesized by the same synthesis method as the organometallic compound of the present invention synthesized above.

<Example 1 and Comparative Example 1>
-Preparation of electrolyte solution To 1M LiPF ₆ ethylene carbonate / ethyl methyl carbonate (volume ratio 1 to 2) electrolyte solution, an organometallic compound shown in Table 1 below was added in the amount shown in Table 1, and a test electrolyte solution was added. Prepared.

-Preparation of 2032 type coin battery The positive electrode is composed of 85% by mass of active material: lithium manganate (LiMn ₂ O ₄ ), conductive auxiliary agent: 7% by mass of carbon black, binder: 8% by mass of PVDF (polyvinylidene fluoride). It was made with.
A negative electrode was produced with a composition of 92% by mass of active material: Gr (natural graphite) and 8% by mass of binder: PVDF.
As the separator, a polypropylene separator having a thickness of 25 μm was prepared.
Using the positive and negative electrodes and separators described above, each test electrolyte solution prepared was used to produce a 2032 type coin battery.

About each produced battery, the capacity maintenance rate after 300 cycles was evaluated as follows.

<Capacity maintenance rate-300 cycles>
Each of the produced 2032 type coin batteries was charged in a constant current of 1 C in a constant temperature bath at 60 ° C. until the battery voltage reached 4.05 V at 4.0 mA, and then the current value at a constant voltage of 4.15 V. Until 0.02 mA. However, the upper limit of the charging time was 2 hours. Next, constant current discharge at 1 C was performed until the battery voltage became 2.75 V at 4.0 mA. This was one cycle. This was repeated until 300 cycles were reached, and the discharge capacity (mAh) at the 300th cycle was measured.
Here, 1C represents a current value for discharging or charging the battery capacity in one hour.
Based on the obtained value, the discharge capacity retention rate (%) was calculated based on the following formula.
In Table 1, the discharge capacity maintenance rate is abbreviated as the capacity maintenance rate.

Discharge capacity maintenance rate (%) =
(Discharge capacity at the 300th cycle / discharge capacity at the first cycle) × 100

The obtained results are shown in Table 1 below.
In addition, the organometallic compound in following Table 1 shows the specific example of the organometallic compound represented by Formula (I) described in the specification.

From Table 1 above, the 2032 type coin battery (101 to 114) of the present invention has a discharge capacity maintenance rate of 76 to 95%. By using the organometallic compound of the present invention, the comparison without using the organometallic compound is performed. Compared to the 2032 type coin battery (c01) of the example, the discharge capacity retention rate is improved by 11% or more.
On the other hand, in the 2032 type coin battery (c02) using the ferrocene of the comparative example, it is presumed that the self-discharge progresses due to the redox shuttle and the capacity maintenance rate is lowered. It seems that ferrocene cannot form a film on the positive electrode in a battery having a low driving voltage, and the capacity retention rate is lowered.
As a result, it can be seen that the present invention can achieve high cycle characteristics in the lithium ion secondary battery.

<Example 2 and Comparative Example 2>
Preparation of electrolyte solution 1.1M LiPF ₆ ethylene carbonate / ethyl methyl carbonate (volume ratio 1 to 2) To the electrolyte solution, an organometallic compound and a phosphazene compound were added in amounts shown in Table 2, and further vinylene was added. An electrolytic solution for each test was prepared by adding 1% by mass of carbonate to the total electrolytic solution and 1% by mass of lithium bisoxalate borate with respect to the total electrolytic solution. All the prepared electrolyte solutions had a viscosity at 25 ° C. of 5 mPa · s or less, and the water content measured by the Karl Fischer method (JIS K0113) was 20 ppm or less.

<Flame retardance>
The 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 2 cm in total flame length ignites for 3 seconds at the position where it touches the tip of the glass filter paper, and the behavior after releasing the flame (ignition / non-ignition, extinguishing after ignition, flame from ignition point to the other end) Was evaluated as follows. Test No. with no additive added. In the glass filter paper using the electrolytic solution of C201, the time for the flame to reach from the ignition point to the other end was less than 5 seconds.

[Evaluation criteria]
A: Ignition was not seen and it was nonflammable.
B: Fire was ignited but extinguished immediately.
C: Fired, but extinguished before the flame reached from the ignition point to the other end.
D: The time for the flame to reach from the ignition point to the other end is 10 seconds or more, and the combustion suppressing effect is seen, but the level does not lead to non-flammability and extinction.
E: The time for the flame to reach from the ignition point to the other end is less than 10 seconds, and there is no combustion suppression effect.

-Production of 2032 type coin battery The positive electrode is made of active material: lithium nickel manganese cobaltate (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ ) 95% by mass, conductive auxiliary agent: carbon black 2% by mass, binder: PVDF (polyvinylidene fluoride) was prepared with a composition of 3% by mass.
A negative electrode was prepared with a composition of 97% by mass of active material: graphite, 2% by mass of binder: styrene butadiene rubber (SBR), and 1% by mass of thickener: sodium carboxymethylcellulose (CMC).
As the separator, a polypropylene separator having a thickness of 25 μm was prepared.
Using the positive and negative electrodes and separators described above, each test electrolyte solution prepared was used to produce a 2032 type coin battery.

<Battery initialization>
The 2032 type coin battery produced above was charged at a constant current of 0.2 C in a thermostat bath at 30 ° C. until the battery voltage reached 4.3 V, and then the current value was 0.12 mA at a constant voltage of 4.3 V. The battery was charged until 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 initialized by the above method. The results are shown in Table 2.
Here, 1C represents a current value for discharging or charging the battery capacity in one hour, 0.2C is 0.2 times, 0.5C is 0.5 times, and 2C is twice the current value. Represents.

(First discharge capacity)
The battery initialized by the above method was charged at a constant current of 0.7 C in a thermostatic chamber at 30 ° C. until the battery voltage reached 4.35 V, and then the current value at a constant voltage of 4.35 V was 0.03 C. The battery was charged until However, the upper limit of the time was 2 hours. This battery was subjected to 0.5C constant current discharge in a constant temperature bath at 30 ° C. until the battery voltage reached 2.75V, and the initial discharge capacity (W ₁ ) at 30 ° C. and 0.5C was measured.

(Cycle test)
The battery whose discharge capacity (W ₁ ) was measured was charged at a constant current of 0.7 C in a constant temperature bath at 45 ° C. until the battery voltage reached 4.35 V, and then the current value was 0 at a constant voltage of 4.35 V. The battery was charged until it reached 0.03C. However, the upper limit of the time was 2 hours. A cycle of performing 0.5C constant current discharge in a 45 ° C. thermostat until the battery voltage reached 2.75 V was repeated 300 times.

(Discharge capacity after cycle test)
The battery after the cycle test was charged and discharged under the same conditions as those for the initial discharge capacity (W ₁ ), and the discharge capacity after the cycle test (W ₃₀₀ ) was measured.

<Discharge capacity maintenance rate after cycle test>
From the obtained results, the discharge capacity retention rate after the cycle test was calculated by the following formula.

Discharge capacity maintenance rate after cycle test =
Discharge capacity after cycle test (W ₃₀₀ ) / initial discharge capacity (W ₁ )

The obtained discharge capacity maintenance rate was evaluated as follows. The larger the value, the higher the capacity is maintained even under severe test conditions.

[Evaluation criteria]
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

The obtained results are shown in Table 2 below.
In Tables 2 to 5 below, the organometallic compound and the phosphazene compound are specific examples of the organometallic compound represented by the formula (I) and the phosphazene compound described in the specification. Further, the discharge capacity maintenance rate after the cycle test is abbreviated as “discharge capacity maintenance rate”.

<Example 3 and Comparative Example 3>
The electrolyte was changed to 1M LiPF ₆ ethylene carbonate / ethyl methyl carbonate / dimethyl carbonate (volume ratio 1: 1 to 1: 1), the positive electrode active material was changed to lithium cobaltate (LiCoO ₂ ), and the lithium bisoxalate borate was changed to succinonitrile. Then, the same operations as in Example 2 and Comparative Example 2 were carried out except that the organometallic compounds and phosphazene compounds shown in Table 3 below were added in the amounts shown in Table 3. The results are shown in Table 3.

<Example 4 and Comparative Example 4>
The electrolyte solution was changed to 1.1M LiPF ₆ ethylene carbonate / dimethyl carbonate (volume ratio 1 to 2), and the organometallic compounds and phosphazene compounds shown in Table 4 below were added in the amounts shown in Table 4. The same operations as in Example 2 and Comparative Example 2 were performed. The results are shown in Table 4.

<Example 5 and Comparative Example 5>
The electrolyte is 0.9M LiBF ₄ ethylene carbonate / diethyl carbonate (volume ratio 1: 1), the positive electrode active material is nickel cobalt lithium aluminumate (LiNi _0.8 Co _0.15 Al _0.05 O ₂ ), vinylene carbonate Was changed to fluoroethylene carbonate, and the same operations as in Example 2 and Comparative Example 2 were carried out except that the organometallic compounds and phosphazene compounds shown in Table 5 below were added in the amounts shown in Table 5. The results are shown in Table 5.

From the results shown in Tables 2 to 5, the lithium ion secondary battery using the organometallic compound of the present invention shows a good discharge capacity retention rate. It can also be seen that by using the phosphazene compound represented by the formula (A1) or (A2) in combination, a high discharge capacity retention rate can be achieved even under severe use conditions while realizing high flame retardancy.

While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

This application claims priority based on Japanese Patent Application No. 2014-169910 filed in Japan on August 22, 2014 and Japanese Patent Application No. 2015-034908 filed on February 25, 2015 in Japan. Which is hereby incorporated by reference herein as part of its description.

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

The electrolyte solution for non-aqueous secondary batteries containing the organometallic compound represented by following formula (I), and content of this organometallic compound is more than 0 mass% and 1 mass% or less.

In the formula (I), M represents a metal element.
R 1 and R 2 each independently represents a substituent. When there are a plurality of R 1 and R 2 , a plurality of R 1 or a plurality of R 2 may be bonded to each other to form an aliphatic or aromatic ring. X and Y each independently represent a hydrogen atom or a substituent. X and Y, or a plurality of Xs or Ys in the case where a plurality exist, may be bonded to each other to form a ring. L represents a linking group.
a and b each independently represents an integer of 0 to 4.
m and n represent integers satisfying 0 ≦ m + n ≦ 3.
L is a hydrocarbon group having 1 to 20 carbon atoms, a group containing a halogen atom, a group containing a silicon atom, a group containing a nitrogen atom, a group containing a phosphorus atom, a group containing a titanium atom, or a group containing a zirconium atom The electrolyte solution for non-aqueous secondary batteries according to claim 1.
R 1 and R 2 are each independently an alkyl group, alkenyl group, alkynyl group, alkoxy group, alkylthio group, aryloxy group, amino group, group containing an amide bond, group containing an ester bond, cyano group, carboxy group The electrolyte solution for a non-aqueous secondary battery according to claim 1 or 2, which is a group, a group containing a carbonyl bond, a group containing a sulfonyl bond, a phosphino group or a halogen atom.
X and Y are each independently a hydrogen atom, alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkylamino group, silylamino group, sulfo group, isocyanate group, isothiocyanate group, sulfanyl group, phosphinyl group. The electrolyte solution for a nonaqueous secondary battery according to any one of claims 1 to 3, which is a group containing a carbonyl bond, a halogen atom, an aryl group, or a heteroaryl group.
The electrolyte for a non-aqueous secondary battery according to any one of claims 1 to 4, wherein the M is a transition element of Group 4 to Group 8.
The electrolyte for a non-aqueous secondary battery according to any one of claims 1 to 5, wherein L is any one of groups represented by the following formulas (i) to (viii).

In the formulas (i) to (viii), R 3 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylamino group, a silylamino group, a sulfo group, an isocyanate group, an isothiocyanate group, It represents a sulfanyl group, a phosphinyl group, a group containing a carbonyl bond, a halogen atom, an aryl group or a heteroaryl group. When R 3 is more present in the linking group, the plurality of R 3 may be the same even if different from each other. A plurality of R 3 may be bonded to each other to form a ring.
The electrolyte solution for a non-aqueous secondary battery according to any one of claims 1 to 6, further comprising at least one phosphazene compound.
The electrolyte solution for a non-aqueous secondary battery according to claim 7, wherein the phosphazene compound is represented by the following formula (A1) or (A2).

In the formulas (A1) and (A2), Ra 11 to Ra 16 and Ra 21 to Ra 28 each independently represent a monovalent substituent. The adjacent Ra 11 to Ra 16 and Ra 21 to Ra 28 may be bonded to each other to form a ring.
The electrolyte solution for a non-aqueous secondary battery according to claim 8, wherein the compound represented by the formula (A1) is a fluorinated phosphazene compound represented by the following formula (A1-1).

In the formula (A1-1), Ra 41 represents an alkoxy group or a dialkylamino group.
The electrolyte for a non-aqueous secondary battery according to claim 9, wherein the Ra 41 is a dialkylamino group.
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 10.
The additive used for the electrolyte solution for non-aqueous secondary batteries represented by following formula (I).

In the formula (I), M represents a metal element.
R 1 and R 2 each independently represents a substituent. When there are a plurality of R 1 and R 2 , a plurality of R 1 or a plurality of R 2 may be bonded to each other to form an aliphatic or aromatic ring. X and Y each independently represent a hydrogen atom or a substituent. X and Y, or a plurality of Xs or Ys in the case where a plurality exist, may be bonded to each other to form a ring. L represents a linking group.
a and b each independently represents an integer of 0 to 4.
m and n represent integers satisfying 0 ≦ m + n ≦ 3.