WO2010053162A1

WO2010053162A1 - Non-aqueous electrolysis solution containing pyridyl 5-membered heterocyclic derivative, and lithium secondary battery

Info

Publication number: WO2010053162A1
Application number: PCT/JP2009/069007
Authority: WO
Inventors: 茂三尾; 光雄中村; 栄信野木; 剛史林; 秀俊角田
Original assignee: 三井化学株式会社
Priority date: 2008-11-07
Filing date: 2009-11-06
Publication date: 2010-05-14
Also published as: JP5285082B2; JPWO2010053162A1

Abstract

Disclosed is a non-aqueous electrolysis solution containing a compound represented by general formula (I). In general formula (I), Py represents a pyridyl group which may be substituted by 1 to 3 substituents; Q represents an aromatic or non-aromatic 5-membered hetero ring which may contain 1 to 4 atoms independently selected from an oxygen atom, a sulfur atom and a nitrogen atom and may be substituted by 1 to 2 substituents; and n represents 1 or 2. Py-(Q)_n (I)

Description

Non-aqueous electrolyte and lithium secondary battery containing pyridyl 5-membered heterocyclic derivative

The present invention relates to a non-aqueous electrolyte and a lithium secondary battery.

Various active materials containing lithium and a transition metal are known as positive electrode active materials for lithium secondary batteries. In many conventional lithium secondary batteries, the main component of the transition metal used as the positive electrode active material is cobalt or nickel. The reason why cobalt or nickel is frequently used is that it is easy to realize a long battery life as compared with other transition metals.

However, cobalt or nickel, which has been widely used heretofore, is expensive and has a limited amount of resources. Instead of cobalt or nickel due to the large increase in demand for lithium secondary batteries in recent years and the dramatic increase in demand for large battery applications such as automotive and new energy storage applications in the near future. Therefore, there is a strong demand for conversion to a transition metal positive electrode active material that is inexpensive and has abundant resources.

Among them, manganese, which is cheaper and richer in resources than cobalt or nickel, is one of the potential next-generation cathode active material candidates. However, in general, a battery using a manganese positive electrode has a shorter life than a battery using a cobalt or nickel positive electrode. On the other hand, the required performance in the large battery market, where a dramatic increase in demand is expected in the near future, is to extend the battery life.

Especially the problem to be solved is the deterioration of the battery performance under high temperature environment. Deterioration of a lithium secondary battery in a high temperature environment is caused by various factors. Examples of such factors include alteration of the lithium transition metal oxide, decomposition of the electrolytic solution, and destruction of the film formed on the negative electrode surface. As one method for preventing such deterioration of battery performance, attempts have been made to extend the life by adding a pyridine derivative to the electrolytic solution. For example, Japanese Patent Application Laid-Open No. 2002-83631 discloses an example of adding pyridine, Japanese Patent Application Laid-Open No. 2002-93462 is an alkylpyridine derivative, and Japanese Patent Application Laid-Open No. 2004-14352 is an example of adding a bipyridine derivative. However, improvement of capacity degradation under high temperature conditions is a situation where further improvement is required.

An object of the present invention is to use a non-aqueous electrolyte and an additive for a lithium secondary battery that can improve the storage characteristics in a high-temperature environment and realize a long life in a lithium secondary battery, and the non-aqueous electrolyte. It is to provide a lithium secondary battery.

As a result of intensive studies on the above problems, the present inventor can improve the storage characteristics in a high temperature environment and achieve a long life by adding a specific additive to the non-aqueous electrolyte of the lithium secondary battery. The present invention has been completed.

That is, the present invention is as follows.

<1> A nonaqueous electrolytic solution for a lithium secondary battery containing a compound represented by the following general formula (I).

In general formula (I), Py represents a pyridyl group which may be substituted with 1 to 3 substituents selected from group A below.

Group A includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Alkoxy group, alkenyloxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkylsulfonyl having 1 to 8 carbon atoms Group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom Or bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms to form a 3- to 7-membered ring, a phenyloxy group (halogen atom or alkyl having 1 to 6 carbon atoms) On the basis Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (carbon of the alkyl group) N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly or oxygen atoms, A sulfur atom or a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms may be bonded to each other to form a 3- to 7-membered ring), a phenyl group (halogen atom or having 1 to 6 carbon atoms) May be substituted with an alkyl group), an aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon). It is substituted with 1-6 alkyl groups a group consisting also be).

N represents 1 or 2.

Q represents an aromatic or non-aromatic 5-membered heterocyclic group which may contain 1 to 4 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom, and the heterocyclic ring is selected from the following group B May be substituted by 1 to 2 substituents.

Group B includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Alkoxy group, alkenyloxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkylsulfonyl having 1 to 8 carbon atoms Group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom Or bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms to form a 3- to 7-membered ring, a phenyloxy group (halogen atom or alkyl having 1 to 6 carbon atoms) On the basis Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (carbon of the alkyl group) N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly or oxygen atoms, A sulfur atom or a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms may be bonded to each other to form a 3- to 7-membered ring), a phenyl group (halogen atom or having 1 to 6 carbon atoms) May be substituted with an alkyl group), an aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon). It is substituted with 1-6 alkyl groups a group consisting also be).

<2> Q in the general formula (I) is a furyl group, a thienyl group, a pyrrolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an imidazolyl group, a pyrazolyl group, a 1,2,4-oxadiazolyl group, 1 The nonaqueous electrolytic solution according to <1>, which is a 1,3,4-oxadiazolyl group, an oxazolinyl group, an isoxazolinyl group, an imidazolinyl group, or a pyrazolinyl group.

<3> Q in the general formula (I) is an isoxazol-3-yl group, an isoxazolin-3-yl group, an isoxazolin-5-yl group, or a 1,2,4-oxadiazole-5- The nonaqueous electrolytic solution according to <1>, which is an yl group.

<4> The compound represented by the general formula (I) is 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylic acid, 3- (pyridin-3-yl) -4 , 5-Dihydroisoxazole-5-carboxylic acid, 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5-carboxylic acid, 3- (pyridin-2-yl) -4,5-dihydro Isoxazole-5-carboxylate methyl, 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylate, 3- (pyridin-4-yl) -4,5-dihydroisoxazole -5-carboxylate, 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carbonitrile, 3- (pyridin-3-yl) -4,5-dihydroisoxazo 5-carbonitrile, 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5-carbonitrile, 3- (pyridin-2-yl) -isoxazole-5-carbonitrile, 3 -(Pyridin-3-yl) -isoxazole-5-carbonitrile, 3- (pyridin-4-yl) -isoxazole-5-carbonitrile, 3- (pyridin-2-yl) -isoxazole-5- Carboxylic acid, 3- (pyridin-3-yl) -isoxazole-5-carboxylic acid, 3- (pyridin-4-yl) -isoxazole-5-carboxylic acid, 3- (pyridin-2-yl) -iso Methyl oxazol-5-carboxylate, 3- (pyridin-3-yl) -isoxazole-5-carboxylate, 3- (pyridin-4-yl) -isoxa Methyl 5-carboxylate, 3- (pyridin-2-yl) -isoxazole, 3- (pyridin-3-yl) -isoxazole, 3- (pyridin-4-yl) -isoxazole, 3- (Pyridin-2-yl) -1,2,4-oxadiazole, 3- (Pyridin-3-yl) -1,2,4-oxadiazole, 3- (Pyridin-4-yl) -1, 2,4-oxadiazole, 3-methyl-5- (pyridin-2-yl) -4,5-dihydroisoxazole, 5- (pyridin-2-yl) -4,5-dihydroisoxazole-3- Ethyl carboxylate, 5- (pyridin-2-yl) -4,5-dihydroisoxazole-3-carbonitrile, 3-methyl-5- (pyridin-3-yl) -4,5-dihydroisoxazole, 5 -(Piri N-yl) -4,5-dihydroisoxazole-3-carboxylate or 5- (pyridin-3-yl) -4,5-dihydroisoxazole-3-carbonitrile in <1> The non-aqueous electrolyte described.

<5> The nonaqueous electrolytic solution according to any one of <1> to <4>, further containing a compound represented by the following general formula (II).

In general formula (II), R ¹ , R ² , R ³ , and R ⁴ are each independently an alkyl group having 1 to 12 carbon atoms, a hydrogen atom, or a fluorine atom that may be substituted with a fluorine atom. M represents an integer of 0 to 3. When m is 2 or 3, a plurality of R ³ and R ⁴ may be the same or different from each other.

<6> The nonaqueous electrolytic solution according to <5>, wherein the content of the compound represented by the general formula (II) is 0.001% by mass to 10% by mass.

<7> The nonaqueous electrolytic solution according to any one of <1> to <6>, further comprising a compound represented by the following general formula (III).

In general formula (III), R ⁵ and R ⁶ each independently represent a hydrogen atom, a methyl group, an ethyl group, or a propyl group.

<8> The nonaqueous electrolytic solution according to <7>, wherein the content of the compound represented by the general formula (III) is 0.001% by mass to 10% by mass.

<9> The nonaqueous electrolytic solution according to any one of <1> to <8>, further comprising a compound represented by the following general formula (IV).

[In the general formula (IV), X ¹ , X ² , X ³ and X ⁴ are each independently an alkyl group having 1 to 3 carbon atoms which may be substituted with a fluorine atom, a hydrogen atom, a fluorine atom, or chlorine. Indicates an atom. However, the case where X ¹ , X ² , X ³ and X ⁴ are hydrogen atoms at the same time is excluded. ]

<10> The nonaqueous electrolytic solution according to <9>, wherein the content of the compound represented by the general formula (IV) is 0.001% by mass to 10% by mass.

<11> The nonaqueous electrolytic solution according to any one of <1> to <10>, wherein the content of the compound represented by the general formula (I) is 0.001% by mass to 10% by mass.

<12> a positive electrode;
Metallic lithium, lithium-containing alloys, metals that can be alloyed with lithium, alloys that can be alloyed with lithium, oxides that can be doped / undoped with lithium ions, and metals that can be doped / undoped with lithium ions A negative electrode containing, as a negative electrode active material, at least one selected from transition metal nitrides and carbon materials capable of doping and dedoping lithium ions;
<1> to the nonaqueous electrolyte solution according to any one of <11>,
A lithium secondary battery.

<13> An additive for a lithium secondary battery containing a compound represented by the following general formula (I).

N represents 1 or 2.

Q represents an aromatic or non-aromatic 5-membered heterocyclic group which may contain 1 to 4 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom, and the heterocyclic ring is selected from the following group B May be substituted by 1 to 2 substituents.
Group B includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Alkoxy group, alkenyloxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkylsulfonyl having 1 to 8 carbon atoms Group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom Or bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms to form a 3- to 7-membered ring, a phenyloxy group (halogen atom or alkyl having 1 to 6 carbon atoms) Set by group Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (the carbon number of the alkyl group) Are 1 to 8), N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly or oxygen atom, sulfur Via a nitrogen atom substituted with an atom or an alkyl group having 1 to 6 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or alkyl having 1 to 6 carbon atoms) An aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon number). It is substituted with an alkyl group having 1-6 a group consisting also be).

According to the present invention, in a lithium secondary battery, a non-aqueous electrolyte and an additive for a lithium secondary battery capable of improving storage characteristics in a high temperature environment and realizing a long life, and the non-aqueous electrolyte are used. A lithium secondary battery can be provided.

It is typical sectional drawing of the coin-type battery which shows an example of the lithium secondary battery of this invention.

The non-aqueous electrolyte of the present invention, the lithium secondary battery using this non-aqueous electrolyte, and the additive for lithium secondary battery will be specifically described.

<Non-aqueous electrolyte>
The non-aqueous electrolyte of the present invention includes, as an additive, a pyridyl 5-membered heterocyclic compound (hereinafter referred to as “pyridyl represented by the general formula (I)”, which is a compound represented by the general formula (I) described herein. And a non-aqueous electrolyte solution for use in lithium secondary batteries.
The non-aqueous electrolytic solution of the present invention further includes, as an additive, an unsaturated sultone that is a compound represented by the general formula (II) (hereinafter also referred to as “unsaturated sultone represented by the general formula (II)”). A vinylene carbonate derivative which is a compound represented by the general formula (III) (hereinafter, also referred to as “a vinylene carbonate derivative represented by the general formula (III)”), and a compound represented by the general formula (IV) It may contain at least one selected from the group consisting of halogenated cyclic carbonate derivatives (hereinafter also referred to as “halogenated cyclic carbonate derivatives represented by the general formula (IV)”).

(Pyridyl 5-membered heterocyclic compound)
The non-aqueous electrolyte of the lithium secondary battery of the present invention contains a compound represented by the following general formula (I) (hereinafter also referred to as “pyridyl 5-membered heterocyclic compound represented by the general formula (I)”). To do.

In general formula (I), Py represents a pyridyl group which may be substituted with 1 to 3 substituents selected from Group A.

The group A includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and 1 to 8 carbon atoms. Alkoxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkyl having 1 to 8 carbon atoms A sulfonyl group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly or oxygen atom, sulfur Via a nitrogen atom substituted with an atom or an alkyl group having 1 to 6 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring), a phenyloxy group (halogen atom or having 1 to 6 carbon atoms) Alkyl Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (of the alkyl group) Carbon number is 1 to 8), N, N-dialkylaminocarbonyl group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly or oxygen atoms) , A sulfur atom, or a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms, which may combine with each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or 1 to 6 carbon atoms) An aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or Is substituted with an alkyl group of prime 1-6 is a group consisting also be).

N represents 1 or 2.

Q represents an aromatic or non-aromatic 5-membered heterocyclic group which may contain 1 to 4 atoms selected from oxygen atom, sulfur atom and nitrogen atom, and the heterocyclic ring is selected from group B It may be substituted with 1 to 2 substituents.

The group B includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and 1 to 8 carbon atoms. Alkoxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkyl having 1 to 8 carbon atoms A sulfonyl group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly or oxygen atom, sulfur Via a nitrogen atom substituted with an atom or an alkyl group having 1 to 6 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring), a phenyloxy group (halogen atom or having 1 to 6 carbon atoms) Alkyl Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (of the alkyl group) Carbon number is 1 to 8), N, N-dialkylaminocarbonyl group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly or oxygen atoms) , A sulfur atom, or a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms, which may combine with each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or 1 to 6 carbon atoms) An aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or Is substituted with an alkyl group of prime 1-6 is a group consisting also be).

Examples of the halogen atom in the general formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Among them, preferred are a fluorine atom and a chlorine atom, and more preferred is a fluorine atom.

Examples of the alkyl group having 1 to 8 carbon atoms in the general formula (I) include methyl group, ethyl group, propyl group, 2-propyl group, butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group. Group, 1-methylethyl group, 1-methylbutyl group, 1-methylpentyl group, 1-methylhexyl group, 2,2-dimethylethyl group, 2,2-dimethylpropyl group.
Among them, preferred is a methyl group, an ethyl group, a propyl group, a 2-propyl group, a butyl group, a tert-butyl group, a pentyl group, a hexyl group, or a 2,2-dimethylethyl group, more preferably a methyl group, tert-Butyl group.

Examples of the cycloalkyl group having 3 to 6 carbon atoms in the general formula (I) include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
Among these, a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group are preferable, and a cyclohexyl group is more preferable.

Examples of the alkenyl group having 2 to 6 carbon atoms in the general formula (I) include a vinyl group, 2-propenyl group, 2-methyl-2-propenyl group, 3-methyl-2-butenyl group, 3-butenyl group, 4- Examples include a pentenyl group and a 5-hexenyl group.
Of these, 2-propenyl group, 2-methyl-2-propenyl group, 3-methyl-2-butenyl group, 3-butenyl group, 4-pentenyl group, and 5-hexenyl group are more preferable, and 2 -Propenyl group, 2-methyl-2-propenyl group.

Examples of the alkynyl group having 2 to 6 carbon atoms in the general formula (I) include ethynyl group, prop-2-ynyl group, but-3-ynyl group, pent-4-ynyl group, hexa-5-ynyl group, prop- Examples include a 1-ynyl group, a but-1-ynyl group, and a 2-but-2-ynyl group.
Among them, preferred is an ethynyl group, prop-2-ynyl group, but-3-ynyl group, pent-4-ynyl group, or hexa-5-ynyl group, and more preferred is an ethynyl group or prop-2-ynyl group. It is a group.

As the alkoxy group having 1 to 8 carbon atoms in the general formula (I), methoxy group, ethoxy group, propoxy group, iso-propoxy group, butoxy group, iso-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy Group, 2,2-dimethyl-1-propoxy group, heptyloxy group, octyloxy group.
Among them, preferably a methoxy group, an ethoxy group, a propoxy group, an iso-propoxy group, a butoxy group, an iso-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group, and more preferably a methoxy group, an iso -Propoxy group, tert-butoxy group.

Examples of the alkenyloxy group having 2 to 6 carbon atoms in the general formula (I) include vinyloxy group, allyloxy group, 2-methylallyloxy group, but-2-enyloxy group, 3-methyl-but-2-enyloxy group, buto Examples include a -3-enyloxy group, a pent-4-enyloxy group, and a hexa-5-enyloxy group.
Among them, preferred are allyloxy group, 2-methylallyloxy group, but-2-enyloxy group, 3-methyl-but-2-enyloxy group, but-3-enyloxy group, and more preferred are allyloxy group, -A methylallyloxy group.

The alkynyloxy group having 2 to 6 carbon atoms in the general formula (I) includes an ethynyloxy group, a prop-2-ynyloxy group, a but-3-ynyloxy group, a pent-4-ynyloxy group, and a hexa-5-ynyloxy group. Illustrated.
Among them, preferred is a prop-2-ynyloxy group, a but-3-ynyloxy group, and a pent-4-ynyloxy group, and more preferred is a prop-2-ynyloxy group.

Examples of the alkylthio group having 1 to 8 carbon atoms in the general formula (I) include methylthio group, ethylthio group, propylthio group, iso-propylthio group, butylthio group, iso-butylthio group, tert-butylthio group, pentylthio group, and hexylthio group. 2,2-dimethyl-1-propylthio group, heptylthio group, octylthio group.
Among them, preferably a methylthio group, an ethylthio group, a propylthio group, an iso-propylthio group, a butylthio group, an iso-butylthio group, a tert-butylthio group, a pentylthio group, and a hexylthio group, and more preferably a methylthio group, an iso- A propylthio group and a tert-butylthio group;

Examples of the alkylsulfinyl group having 1 to 8 carbon atoms in the general formula (I) include methylsulfinyl group, ethylsulfinyl group, propylsulfinyl group, iso-propylsulfinyl group, butylsulfinyl group, iso-butylsulfinyl group, tert-butylsulfinyl group Group, pentylsulfinyl group, hexylsulfinyl group, 2,2-dimethyl-1-propylsulfinyl group, heptylsulfinyl group, octylsulfinyl group.
Among them, preferred are a methylsulfinyl group, an ethylsulfinyl group, a propylsulfinyl group, an iso-propylsulfinyl group, a butylsulfinyl group, an iso-butylsulfinyl group, a tert-butylsulfinyl group, a pentylsulfinyl group, and a hexylsulfinyl group. And more preferably a methylsulfinyl group, an iso-propylsulfinyl group, or a tert-butylsulfinyl group.

Examples of the alkylsulfonyl group having 1 to 8 carbon atoms in the general formula (I) include methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, iso-propylsulfonyl group, butylsulfonyl group, iso-butylsulfonyl group, tert-butylsulfonyl Group, pentylsulfonyl group, hexylsulfonyl group, 2,2-dimethyl-1-propylsulfonyl group, heptylsulfonyl group and octylsulfonyl group.
Among them, preferred are a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, an iso-propylsulfonyl group, a butylsulfonyl group, an iso-butylsulfonyl group, a tert-butylsulfonyl group, a pentylsulfonyl group, and a hexylsulfonyl group. And more preferably a methylsulfonyl group, an iso-propylsulfonyl group, or a tert-butylsulfonyl group.

Examples of the alkylamino group having 1 to 8 carbon atoms in the general formula (I) include a methylamino group, an ethylamino group, a propylamino group, an iso-propylamino group, a butylamino group, an iso-butylamino group, and a tert-butylamino group. Group, pentylamino group, hexylamino group, 2,2-dimethyl-1-propylamino group, heptylamino group and octylamino group.
Among them, a methylamino group, an ethylamino group, a propylamino group, an iso-propylamino group, a butylamino group, an iso-butylamino group, a tert-butylamino group, a pentylamino group, a hexylamino group, and more A methylamino group, an iso-propylamino group, and a tert-butylamino group are preferable.

In the general formula (I), the dialkylamino group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom, or carbon number) A 3- to 7-membered ring may be bonded to each other via a nitrogen atom substituted with 1 to 6 alkyl groups), such as dimethylamino group, diethylamino group, dipropylamino group, di-iso- Propylamino group, dibutylamino group, di-iso-butylamino group, dipentylamino group, dihexylamino group, diheptylamino group, dioctylamino group, aziridin-1-yl group, azetidin-1-yl group, pyrrolidine-1 -Yl group, piperidin-1-yl group, 4-morpholino group, 4-thiomorpholino group, 4-methylpiperazin-1-yl group, 4-ethylpiperazine-1 -Yl group, 4-propylpiperazin-1-yl group, preferably dimethylamino group, diethylamino group, dipropylamino group, di-iso-propylamino group, pyrrolidin-1-yl group, piperidin-1- Ilyl group, 4-morpholino group, 4-thiomorpholino group and 4-methylpiperazin-1-yl group are exemplified.
Of these, a dimethylamino group, a diethylamino group, and a piperidin-1-yl group are more preferable.

In the general formula (I), the alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms) means a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an iso-propoxycarbonyl group, a butoxycarbonyl group, sec- Butoxycarbonyl group, iso-butoxycarbonyl group, tert-butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group, 2,2-dimethyl-1-propoxycarbonyl group, heptyloxycarbonyl group, octyloxycarbonyl group Illustrated.
Among them, preferably, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, iso-propoxycarbonyl group, butoxycarbonyl group, iso-butoxycarbonyl group, tert-butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group And more preferably a methoxycarbonyl group, an iso-propoxycarbonyl group, or a tert-butoxycarbonyl group.

In the general formula (I), the N-alkylaminocarbonyl group (wherein the alkyl group has 1 to 8 carbon atoms) includes a methylaminocarbonyl group, an ethylaminocarbonyl group, a propylaminocarbonyl group, and an iso-propylaminocarbonyl group. Group, butylaminocarbonyl group, iso-butylaminocarbonyl group, tert-butylaminocarbonyl group, pentylaminocarbonyl group, hexylaminocarbonyl group, 2,2-dimethyl-1-propylaminocarbonyl group, heptylaminocarbonyl group And octylaminocarbonyl group.
Among them, preferably, methylaminocarbonyl group, ethylaminocarbonyl group, propylaminocarbonyl group, iso-propylaminocarbonyl group, butylaminocarbonyl group, iso-butylaminocarbonyl group, tert-butylaminocarbonyl group, pentylamino A carbonyl group and a hexylaminocarbonyl group, more preferably a methylaminocarbonyl group, an iso-propylaminocarbonyl group, and a tert-butylaminocarbonyl group.

In the general formula (I), the N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are either directly or an oxygen atom, sulfur A 3- to 7-membered ring may be bonded to each other via an atom or a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms), such as dimethylaminocarbonyl group, diethylaminocarbonyl group, dipropyl Aminocarbonyl group, di-iso-propylaminocarbonyl group, dibutylaminocarbonyl group, di-iso-butylaminocarbonyl group, dipentylaminocarbonyl group, dihexylaminocarbonyl group, diheptylaminocarbonyl group, dioctylaminocarbonyl group, aziridine- 1-carbonyl group, azetidine-1-carbonyl group, pyrrolidine-1- Carbonyl group, piperidine-1-carbonyl group, morpholine-4-carbonyl group, thiomorpholine-4-carbonyl group, 4-methylpiperazine-1-carbonyl group, 4-ethylpiperazine-1-carbonyl group, 4-propylpiperazine- A 1-carbonyl group is exemplified.
Among them, preferably, a dimethylaminocarbonyl group, a diethylaminocarbonyl group, a dipropylaminocarbonyl group, a di-iso-propylaminocarbonyl group, a pyrrolidine-1-carbonyl group, a piperidine-1-carbonyl group, a morpholine-4-carbonyl group, A 4-methylpiperazine-1-carbonyl group, more preferably a dimethylaminocarbonyl group, a diethylaminocarbonyl group, or a piperidine-1-carbonyl group.

In the general formula (I), the phenyl group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms) includes a phenyl group, a methylphenyl group, an ethylphenyl group, a propylphenyl group, and a butylphenyl group. , Pentylphenyl group, hexylphenyl group, chlorophenyl group, fluorophenyl group and bromophenyl group.
Among these, a phenyl group, a methylphenyl group, a fluorophenyl group, and a chlorophenyl group are preferable, and a phenyl group, a methylphenyl group, and a fluorophenyl group are more preferable.

Examples of the aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms) in the general formula (I) include a furyl group, a thienyl group, a pyrrolyl group, an oxazolyl group, and an isoxazolyl group. , Thiazolyl group, isothiazolyl group, imidazolyl group, pyrazolyl group, triazolyl group or tetrazolyl group.
Among them, preferred is a pyrrolyl group, an imidazolyl group, a pyrazolyl group, a triazolyl group or a tetrazolyl group, and more preferred are a pyrrolyl group, an imidazolyl group, a pyrazolyl group or a triazolyl group.

As the aromatic 6-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms) in the general formula (I), a pyridyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group Is exemplified.
Among these, a pyridyl group, a pyrimidinyl group, and a pyrazinyl group are preferable, and a pyridyl group is more preferable.

Aromatic or non-aromatic 5-membered heterocyclic group (containing the heterocyclic group) which may contain 1 to 4 atoms selected from oxygen, sulfur and nitrogen, which is Q in general formula (I) The ring may be substituted with one or two substituents selected from the above-mentioned group B) as furyl group, thienyl group, pyrrolyl group, pyrrolinyl group, pyrrolidinyl group, oxazolyl group, isoxazolyl group, thiazolyl group, Isothiazolyl group, imidazolyl group, pyrazolyl group, pyrazolinyl group, pyrazolidinyl group, 1,2,4-oxadiazolyl group, 1,3,4-oxadiazolyl group, oxazolinyl group, oxazolidinyl group, isoxazolinyl group, isoxazolidinyl group Group, an imidazolinyl group, and an imidazolidinyl group.
Examples of Q include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, Oxazolyl group, isoxazolinyl group, imidazolinyl group and pyrazolyl group are preferable, pyrrolyl group, oxazolyl group, isoxazolyl group, imidazolyl group, pyrazolyl group, 1,2,4-oxadiazolyl group, 1,3,4-oxadiazolyl group, An oxazolinyl group, an isoxazolidinyl group, an imidazolinyl group, and a pyrazolinyl group are more preferable.
Furthermore, an isoxazolyl group, an isoxazolinyl group, or a 1,2,4-oxadiazolyl group is preferable, and an isoxazol-3-yl group, an isoxazolin-3-yl group, or a 1,2,4-oxadiazole A -5-yl group is more preferable, and an isoxazol-3-yl group or an isoxazolin-3-yl group is particularly preferable.

In the present invention, the substituent for substituting the pyridyl group represented by Py is a fluorine atom or a chlorine atom among the substituents exemplified as the group A from the viewpoint of further improving the storage characteristics in a high temperature environment. An alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkynyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 carbon atoms An alkenyloxy group having 4 to 4 carbon atoms, an alkynyloxy group having 2 to 4 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an alkylsulfinyl group having 1 to 6 carbon atoms, an alkylsulfonyl group having 1 to 6 carbon atoms, and 1 to 6 alkylamino groups and dialkylamino groups (the number of carbons in each of the two alkyl groups is independently 1 to 6. The two alkyl groups may be directly or oxygen, sulfur, Are bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 4 carbon atoms to form a 3- to 7-membered ring), a phenyloxy group (halogen atom or an alkyl group having 1 to 4 carbon atoms) Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 6 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (of the alkyl group) Carbon number is 1-6), N, N-dialkylaminocarbonyl group (the carbon number of the two alkyl groups is each independently 1-8. The two alkyl groups are directly or oxygen atoms) , A sulfur atom or a nitrogen atom substituted with an alkyl group having 1 to 4 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or 1 to 4 carbon atoms). May be substituted with an alkyl group), an aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon). A group consisting of an optionally substituted alkyl group of 1 to 4) is preferred,

Fluorine atom, chlorine atom, methyl group, ethyl group, propyl group, butyl group, tert-butyl group, cyclohexyl group, vinyl group, propen-2-yl group, propen-1-yl group, ethynyl group, prop-2- Inyl, methoxy, ethoxy, propyloxy, butoxy, tert-butoxy, allyloxy, 2-methylallyloxy, ethynyl, prop-2-ynyl, methylthio, ethylthio, tert-butylthio Group, methylsulfinyl group, ethylsulfinyl group, tert-butylsulfinyl group, methylsulfonyl group, ethylsulfonyl group, tert-butylsulfonyl group, methylamino group, ethylamino group, propylamino group, tert-butylamino group, dimethylamino Group, diethylamino group, dipropylamino group, di-iso-propylamino group, pyrrolidine -1-yl group, piperidin-1-yl group, 4-morpholino group, 4-methylpiperazin-1-yl group, nitro group, formyl group, cyano group, carboxyl group, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl Group, tert-butoxycarbonyl group, carbamoyl group, N-methylaminocarbonyl group, N-ethylaminocarbonyl group, N-tert-butylaminocarbonyl group, piperidine-1-carbonyl group, morpholine-4-carbonyl group, 4- Methylpiperazine-1-carbonyl group, methylphenyl group, ethylphenyl group, chlorophenyl group, fluorophenyl group, pyrrol-1-yl group, pyrazol-1-yl group, imidazol-1-yl group, triazol-1-yl group , Isoxazol-3-yl group, isoxazole-5- Group, pyridin-2-yl group, pyridin-3-yl group, pyridin-4-yl group, pyrimidin-2-yl group, pyrazin-2-yl group, pyridazin-3-yl group, triazin-2-yl group The group consisting of is more preferable.

More preferably, fluorine atom, chlorine atom, methyl group, tert-butyl group, vinyl group, propen-2-yl group, propen-1-yl group, ethynyl group, prop-2-ynyl group, methoxy group, tert- Butoxy, allyloxy, 2-methylallyloxy, ethynyl, methylthio, tert-butylthio, methylsulfinyl, methylsulfonyl, tert-butylsulfonyl, methylamino, tert-butylamino, dimethylamino Group, piperidin-1-yl group, 4-morpholino group, 4-methylpiperazin-1-yl group, cyano group, carboxyl group, methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, N-methylaminocarbonyl group N-tert-butylaminocarbonyl group, piperidine-1-carbonyl group, morpholine-4 Carbonyl group, pyrrol-1-yl group, pyrazol-1-yl group, imidazol-1-yl group, a triazol-1-yl group, the group consisting of.

Further, the number of substituents selected from the group A that substitutes the pyridyl group represented by Py is preferably 0 to 2, and the pyridyl group represented by Py is more preferably monosubstituted or unsubstituted. preferable.

In the present invention, the substituent for substituting the 5-membered heterocyclic group represented by Q is a fluorine atom among the substituents exemplified as the group B from the viewpoint of further improving the storage characteristics in a high temperature environment. A chlorine atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkynyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, C2-C4 alkenyloxy group, C2-C4 alkynyloxy group, C1-C6 alkylthio group, C1-C6 alkylsulfinyl group, C1-C6 alkylsulfonyl group, carbon An alkylamino group and a dialkylamino group having a number of 1 to 6 (the number of carbon atoms of the two alkyl groups is each independently 1 to 6. The two alkyl groups may be directly or oxygen, sulfur, Are bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 4 carbon atoms to form a 3- to 7-membered ring), a phenyloxy group (halogen atom or an alkyl group having 1 to 4 carbon atoms) Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 6 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (of the alkyl group) Carbon number is 1-6), N, N-dialkylaminocarbonyl group (the carbon number of the two alkyl groups is each independently 1-8. The two alkyl groups are directly or oxygen atoms) , A sulfur atom or a nitrogen atom substituted with an alkyl group having 1 to 4 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or 1 to 4 carbon atoms). May be substituted with an alkyl group), an aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon). A group consisting of an optionally substituted alkyl group of 1 to 4) is preferred,

More preferably, fluorine atom, chlorine atom, methyl group, tert-butyl group, vinyl group, propen-2-yl group, propen-1-yl group, ethynyl group, prop-2-ynyl group, methoxy group, tert- Butoxy, allyloxy, 2-methylallyloxy, ethynyl, methylthio, tert-butylthio, methylsulfinyl, methylsulfonyl, tert-butylsulfonyl, methylamino, tert-butylamino, dimethylamino Group, piperidin-1-yl group, 4-morpholino group, 4-methylpiperazin-1-yl group, cyano group, carboxyl group, methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, N-methylaminocarbonyl group N-tert-butylaminocarbonyl group, piperidine-1-carbonyl group, morpholine-4 It is a group consisting of a carbonyl group.

In addition, the number of substituents substituting the 5-membered heterocyclic group represented by Q is preferably 1 to 2, and particularly preferably 1.

In the present invention, the Py and the Q are preferably bonded at the 2-position, 3-position, or 4-position of the Py.
In particular, when Q is an isoxazolyl group or an isoxazolinyl group, the Py and Q are the 2-position, 3-position, or 4-position of the Py, and the 3-position or 5-position of the Q, respectively. It is preferable to combine with.

In the present invention, the most preferable form of the compound represented by the general formula (I) is that the Py is an unsubstituted pyridyl group from the viewpoint of further improving the storage characteristics in a high temperature environment, and the Q Is an isoxazolyl group or isoxazolinyl group having a substituent at the 5-position, wherein n is 1, and the Py and the Q are the 2-position, 3-position, or 4-position of the Py; The form couple | bonded with 3rd-position or 5th-position of Q is mentioned.

Hereinafter, specific examples (specific examples (1) to (51)) of the compound represented by the general formula (I) will be exemplified, but the present invention is not limited to these specific examples.
Hereinafter, specific examples (1) to (51) are also referred to as exemplary compounds 1 to 51.

The compound represented by the general formula (I) in the present invention is preferably 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylic acid, 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid, 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5-carboxylic acid, 3- (pyridin-2-yl) -4,5 -Methyl dihydroisoxazole-5-carboxylate, 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylate, 3- (pyridin-4-yl) -4,5-dihydro Isoxazole-5-carboxylate methyl, 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carbonitrile, 3- (pyridin-3-yl) -4,5- Dihydroisoxazole-5-carbonitrile, 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5-carbonitrile, 3- (pyridin-2-yl) -isoxazole-5-carbonitrile, 3- (pyridin-3-yl) -isoxazole-5-carbonitrile, 3- (pyridin-4-yl) -isoxazole-5-carbonitrile, 3- (pyridin-2-yl) -isoxazole-5 -Carboxylic acid, 3- (pyridin-3-yl) -isoxazole-5-carboxylic acid, 3- (pyridin-4-yl) -isoxazole-5-carboxylic acid, 3- (pyridin-2-yl)- Methyl isoxazole-5-carboxylate, methyl 3- (pyridin-3-yl) -isoxazole-5-carboxylate, 3- (pyridine-4 Yl) -isoxazole-5-carboxylate, 3- (pyridin-2-yl) -isoxazole, 3- (pyridin-3-yl) -isoxazole, 3- (pyridin-4-yl) -isoxazole 3- (pyridin-2-yl) -1,2,4-oxadiazole, 3- (pyridin-3-yl) -1,2,4-oxadiazole, 3- (pyridin-4-yl) -1,2,4-oxadiazole, 3-methyl-5- (pyridin-2-yl) -4,5-dihydroisoxazole, 5- (pyridin-2-yl) -4,5-dihydroisoxazole -3-ethyl carboxylate, 5- (pyridin-2-yl) -4,5-dihydroisoxazole-3-carbonitrile, 3-methyl-5- (pyridin-3-yl) -4,5-dihydroiso Oki Sol, ethyl 5- (pyridin-3-yl) -4,5-dihydroisoxazole-3-carboxylate, or 5- (pyridin-3-yl) -4,5-dihydroisoxazole-3-carbonitrile is there.

The content of the compound represented by the general formula (I) in the nonaqueous electrolytic solution of the present invention is preferably 0.0001% by mass to 30% by mass, more preferably 0.001% by mass to 10% by mass. 0.1% by mass to 7% by mass is more preferable, and 0.2% by mass to 5% by mass is more preferable.
When the content of the pyridyl 5-membered heterocyclic compound in the non-aqueous electrolyte is within the above range, it is possible to provide an electrolyte that can further improve the storage characteristics in a high-temperature environment and realize a longer life.

In the compound represented by the general formula (I), the pyridylimidazole compound is produced by, for example, the method described in DE1985819 or the method described in Org. Biomol. Chem., 5 (16), 2567-2571, (2007). The

Pyridylimidazoline compounds include, for example, methods described in J. Comb. Chem., 2 (6), 675-680, (2000) 、, Synlett, (18), 2747-2750, (2005) 、, Tetrahedron Lett. 39 (5-6), 459-462, 、 (1998), or Synthetic Commun., 26 (7), 1335-1340, (1996).

Pyridylisoxazole compounds are described in, for example, Org. Lett., 3 (26), 4185-4187, (2001), J. Chem. Soc. Perkin Trans., I, (1), 67-72, ( 1986) or the method described in Synthesis-Stuttgart, (1), 20-24, (1989).

The pyridylisoxazoline compound is, for example, a method described in Synthesis-Stuttgart, (11), 1158-1162, (1994), a method described in Febs. Letters, (1994), 35 (2), 168-170, or Tetrahedron Lett., 36 (2), 327-330, (1995).

The pyridylimidazole compound is, for example, a method described in Tetrahedron Lett., 29 (39), 5013-5016, (1988), Tetrahedron Lett., 45 (47), 8687-8690, (2004) or Heterocycles, 32 (11) , 2111-2118, (1991).

The pyridylimidazoline compound is, for example, a method described in Tetrahedron Lett., 47 (13), 2129-2132, (2006), or a method described in Chem-Eur. J., 13 (6), 1863-1871, (186) Manufactured by.

Pyridylpyrazole compounds are described in, for example, TetrahedronedLett., 44 (33), 6305-6307, (2003), method described in DE 19642320, or Synthesis-Stuttgart, (1), 55-62, (2001) It is manufactured by the method.

The pyridylpyrazoline compound is produced, for example, by the method described in Collect Czech. Chem. C.

The pyridyl-1,2,4-oxadiazole compound is produced, for example, by the method described in Tetrahedron Lett., 42 (8), 1495-1498, (2001).

The pyridyl-1,3,4-oxadiazole compound is produced, for example, by the method described in J. Org. Chem., 65 (7), 2246-2248, (2000).

The pyridyl 5-membered heterocyclic compound represented by the general formula (I) is considered to have a function of trapping moisture and acid content in the electrolytic solution. It can be inferred that this trap effect mainly suppresses elution of transition metal and gas generation of the positive electrode.
Therefore, as a result of containing the compound represented by the general formula (I) in the nonaqueous electrolytic solution, metal deposition on the negative electrode, decomposition of the nonaqueous solvent on the negative electrode, and the like are suppressed. It is presumed that the storage characteristics under high temperature environment are improved.
However, the present invention is not limited by the above estimation.
As described above, the compound represented by the general formula (I) has a high effect of suppressing the reductive decomposition of the nonaqueous electrolytic solution on the negative electrode, and suppresses a decrease in battery capacity due to a high temperature storage test. Moreover, the rise of the interface impedance of the positive electrode during a high-temperature storage test or a cycle test is suppressed, and deterioration of load characteristics is suppressed.

The pyridyl 5-membered heterocyclic compound represented by the general formula (I) may be used alone, but a sultone compound represented by the following general formula (II), or a vinylene represented by the following general formula (III) You may use in combination with at least 1 sort (s) selected from the group which consists of a carbonate or its derivative (s), and the halogenated carbonate derivative represented by the following general formula (IV). By using in combination in this way, it is considered that the high-temperature cycle characteristics of the battery can be further improved.

The sultone compound represented by the general formula (II) shown below is effective as an additive for an electrolytic solution, and it is considered that reductive decomposition occurs at the negative electrode in the electrolytic solution, and the sulfur compound forms a film on the positive electrode side.
Specifically, the unsaturated bond in the unsaturated sultone compound represented by the general formula (II) reacts on the negative electrode and bonds on the negative electrode to form a stable film. On the other hand, the unsaturated sultone that did not form a film on the negative electrode decomposes the unsaturated sultone compound itself by the reductive decomposition of the sultone group on the negative electrode, and the sulfur compound produced by this decomposition is oxidized on the positive electrode. It is conceivable that a film is formed on the positive electrode by reacting. That is, it is considered that unsaturated sultone is a compound that can form a film on both the positive electrode and the negative electrode.
That is, it is considered that the unsaturated sultone represented by the following general formula (II) can suppress a decrease in cycle characteristics due to elution of manganese or the like constituting the positive electrode.

In addition, vinylene carbonate represented by the general formula (III) shown below or a derivative thereof creates a surface film on the negative electrode side and contributes to stabilization of the negative electrode.
Similarly, the halogenated cyclic carbonate derivative represented by the general formula (IV) shown below also forms a surface film on the negative electrode side and contributes to stabilization of the negative electrode.

Therefore, the non-aqueous electrolyte comprises a compound represented by the general formula (I), a compound represented by the following general formula (II), a compound represented by the following general formula (III), and the following general formula ( And at least one selected from the group consisting of the compounds represented by IV), the reductive decomposition of the non-aqueous electrolyte on the negative electrode is suppressed, and the capacity reduction of the battery in the high temperature storage test is suppressed. The generation of gas accompanying the decomposition of the non-aqueous electrolyte is suppressed. Further, an increase in the interface impedance of the positive electrode during a high-temperature storage test or a cycle test is suppressed, and deterioration of load characteristics is suppressed.

In particular, a compound represented by the general formula (II), a compound represented by the general formula (III), and a compound represented by the general formula (III) are trapped due to the presence of the compound represented by the general formula (I) on the electrode. And the formation of a film with at least one selected from the group consisting of the compounds represented by the general formula (IV) becomes more appropriate, effectively suppressing the elution of transition metal and gas generation of the positive electrode. It is presumed that side reactions at the negative electrode and the negative electrode are synergistically suppressed. The present invention is not limited by the above estimation.

(Unsaturated sultone)
The non-aqueous electrolyte of the lithium secondary battery of the present invention preferably contains a compound represented by the following general formula (II).

In the general formula (II), R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom, or fluorine that may be substituted with a fluorine atom An atom, and m represents an integer of 0 to 3. When m is 2 or 3, a plurality of R ³ and R ⁴ may be the same or different from each other.

That is, the compound represented by the general formula (II) is a sultone compound which is a cyclic sulfonic acid ester and has a carbon-carbon unsaturated bond in the ring.

In general formula (II), R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrocarbon group having 1 to 12 carbon atoms, a hydrogen atom, or a fluorine atom that may be substituted with a fluorine atom R ¹ , R ² , R ³ and R ⁴ may be the same as or different from each other. m represents an integer of 0 to 3.

In the general formula (II), the hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a fluorine atom represented by R ¹ , R ² , R ³ and R ⁴ is specifically a methyl group. , Ethyl group, vinyl group, ethynyl group, propyl group, isopropyl group, 1-propenyl group, 2-propenyl group, 1-propynyl group, 2-propynyl group, butyl group, sec-butyl group, tert-butyl group, 1 -Butenyl, 2-butenyl, 3-butenyl, 2-methyl-2-propenyl, 1-methylenepropyl, 1-methyl-2-propenyl, 1,2-dimethylvinyl, 1-butynyl 2-butynyl group, 3-butynyl group, pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-methyl-2-methylpropyl group, 2,2-dimethylpropyl group, phenyl group, Me Ruphenyl, ethylphenyl, vinylphenyl, ethynylphenyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, difluoromethyl, monofluoromethyl, trifluoro Methyl group, trifluoroethyl group, difluoroethyl group, pentafluoroethyl group, pentafluoropropyl group, tetrafluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluorocyclohexyl group, perfluoroheptyl Group, perfluorooctyl group, perfluorononyl group, perfluorodecyl group, perfluoroundecyl group, perfluorododecyl group, fluorophenyl group, difluorophenyl group, trifluorophenyl group, perfluoro group Ruorofeniru group, trifluoromethylphenyl group, a naphthyl group, and biphenyl groups.

Among those exemplified above, the hydrocarbon group represented by R ¹ , R ² , R ³ , and R ⁴ preferably has 4 or less carbon atoms, more preferably 2 or less.

In the general formula (II), it is particularly desirable that all of R ¹ , R ² , R ³ , and R ⁴ are hydrogen atoms.

In the general formula (II), m represents an integer of 0 to 3. It is preferable that m = 1 or 2, and it is more preferable that m = 1.

Of the compounds represented by the general formula (II), the most desirable compound is 1,3-prop-1-ene sultone represented by the following formula.

This compound (1,3-prop-1-ene sultone) can be synthesized by a method described in the following literature.
Angew. Chem. / 70. Jahrg. 1958 / Nr.16, Ger. Pat. 1146870 (1963) (Ca 59, 11259 (1963)), Can. J. Chem., 48, 3704 (1970), Synlett, 1411 , (1988), Chem. Commun., 611 (1997), Tetrahedron, 55, 2245 (1999).

When the non-aqueous electrolyte of the present invention contains the compound represented by the general formula (II), the content of the compound represented by the general formula (II) in the non-aqueous electrolyte of the present invention is 0. It is preferably 0001% by mass to 30% by mass, more preferably 0.001% by mass to 10% by mass, further preferably 0.1% by mass to 7% by mass, and further preferably 0.2% by mass to 5% by mass.
When the amount of unsaturated sultone added to the non-aqueous electrolyte is within the above range, the effect of the present invention is exhibited, and an increase in the interface impedance of the negative electrode is suppressed.

(Vinylene carbonate or vinylene carbonate derivative)
The non-aqueous electrolyte of the lithium secondary battery of the present invention preferably contains a compound represented by the following general formula (III).

In general formula (III), R ⁵ and R ⁶ each independently represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group. R ⁵ and R ⁶ may be the same as or different from each other. That is, the compound represented by the general formula (III) is vinylene carbonate or a vinylene carbonate derivative.

Addition of vinylene carbonate or a vinylene carbonate derivative represented by the general formula (III) is preferable in terms of improving the storage characteristics and cycle characteristics of the battery.

Examples of the vinylene carbonate or vinylene carbonate derivative represented by the general formula (III) include vinylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, propyl vinylene carbonate, dimethyl vinylene carbonate, diethyl vinylene carbonate, and dipropyl vinylene carbonate. The
Among these, as the compound represented by the general formula (III), when R ⁵ and R ⁶ are hydrogen atoms, that is, vinylene carbonate is most preferable.

When the non-aqueous electrolyte of the present invention contains the compound represented by the general formula (III), the content of the compound represented by the general formula (III) in the non-aqueous electrolyte of the present invention is Although it can be appropriately selected depending on the condition, it is preferably 0.001% by mass to 10% by mass, and more preferably 0.1% by mass to 3% by mass.

(Halogenated cyclic carbonate derivative)
The non-aqueous electrolyte of the present invention preferably contains a compound represented by the following general formula (IV), which is a halogenated cyclic carbonate derivative, from the viewpoint of more effectively achieving the effects of the present invention.

In the general formula (IV), X ¹ , X ² , X ³ and X ⁴ are each independently an alkyl group having 1 to 3 carbon atoms, a hydrogen atom, a fluorine atom or a chlorine atom which may be substituted with a fluorine atom Indicates. However, the case where X ¹ , X ² , X ³ and X ⁴ are hydrogen atoms at the same time is excluded.
That is, the compound represented by the general formula (IV) is a halogenated cyclic carbonate derivative.

Examples of the halogenated cyclic carbonate derivative represented by the general formula (IV) include 4-fluoro-1,3-dioxolan-2-one, 4-chloro-1,3-dioxolan-2-one, and 4,5-difluoro. -1,3-dioxolan-2-one, tetrafluoro-1,3-dioxolan-2-one, 4-fluoro-5-chloro-1,3-dioxolan-2-one, 4,5-dichloro-1, 3-dioxolan-2-one, tetrachloro-1,3-dioxolan-2-one, 4,5-bistrifluoromethyl-1,3-dioxolan-2-one, 4-trifluoromethyl-1,3-dioxolane -2-one, 4,5-difluoro-4,5-dimethyl-1,3-dioxolan-2-one, 4-methyl-5,5-difluoro-1,3-dioxolan-2-one, 4, Such as 5,5-difluoro-1,3-dioxolan-2-one are exemplified.

Of these, the compound represented by the general formula (IV) is most preferably 4-fluoro-1,3-dioxolan-2-one or 4,5-difluoro-1,3-dioxolan-2-one. .

When the non-aqueous electrolyte of the present invention contains the compound represented by the general formula (IV), the content of the compound represented by the general formula (IV) in the non-aqueous electrolyte of the present invention is Although it can be appropriately selected depending on the condition, it is preferably 0.001 to 10% by mass, more preferably 0.1 to 3% by mass.

(Non-aqueous solvent)
The nonaqueous electrolytic solution of the present invention contains a nonaqueous solvent.
Various known solvents can be appropriately selected as the non-aqueous solvent, and it is particularly preferable that the non-aqueous solvent comprises a cyclic aprotic solvent and / or a chain aprotic solvent.
The cyclic aprotic solvent is preferably used as a non-aqueous solvent in order to improve the flash point of the solvent in order to improve the safety of the battery. The cyclic aprotic solvent may be used alone or in combination of two or more. In addition, a cyclic aprotic solvent and a chain aprotic solvent may be used as a mixture, but when a chain aprotic solvent is used as a mixture, a chain aprotic solvent is used. The mixing ratio of the solvent is desirably limited to less than 20% by mass ratio with respect to the whole non-aqueous solvent.

-Cyclic aprotic solvent-
Examples of the cyclic aprotic solvent include cyclic carbonates such as ethylene carbonate, cyclic carboxylic acid esters such as γ-butyrolactone, cyclic sulfones such as sulfolane, and cyclic ethers such as dioxolane.

Specific examples of cyclic carbonates include ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, and the like. In particular, ethylene carbonate and propylene carbonate having a high dielectric constant are preferably used. In the case of a battery using graphite as the negative electrode active material, ethylene carbonate is particularly preferable. Moreover, you may use these cyclic carbonates in mixture of 2 or more types.

Specific examples of the cyclic carboxylic acid ester include γ-butyrolactone, δ-valerolactone, alkyl substitution products such as methyl γ-butyrolactone, ethyl γ-butyrolactone, and ethyl δ-valerolactone.

The cyclic carboxylic acid ester has a low vapor pressure, a low viscosity, and a high dielectric constant. For this reason, the viscosity of the electrolytic solution can be lowered without lowering the flash point of the electrolytic solution and the degree of dissociation of the electrolyte. For this reason, since it has the feature that the conductivity of the electrolytic solution, which is an index related to the discharge characteristics of the battery, can be increased without increasing the flammability of the electrolytic solution, when aiming to improve the flash point of the solvent, It is preferable to use a cyclic carboxylic acid ester as the cyclic aprotic solvent. In particular, γ-butyrolactone is most desirable.

In addition, the cyclic carboxylic acid ester is preferably a mixture with another cyclic aprotic solvent. For example, a mixture of a cyclic carboxylic acid ester and a cyclic carbonate and / or a chain carbonate can be considered.

Specific examples of combinations of cyclic carboxylic acid esters and cyclic carbonates and / or chain carbonates include γ-butyrolactone and ethylene carbonate, γ-butyrolactone and ethylene carbonate and dimethyl carbonate, and γ-butyrolactone and ethylene carbonate and methylethyl. Carbonate, γ-butyrolactone and ethylene carbonate and diethyl carbonate, γ-butyrolactone and propylene carbonate, γ-butyrolactone and propylene carbonate and dimethyl carbonate, γ-butyrolactone and propylene carbonate and methyl ethyl carbonate, γ-butyrolactone and propylene carbonate and diethyl carbonate, γ-butyrolactone, ethylene carbonate and propylene carbonate, γ-butyrolactone Ethylene carbonate and propylene carbonate and dimethyl carbonate, γ-butyrolactone and ethylene carbonate and propylene carbonate and methyl ethyl carbonate, γ-butyrolactone and ethylene carbonate, propylene carbonate and diethyl carbonate, γ-butyrolactone, ethylene carbonate, dimethyl carbonate and methyl ethyl carbonate, γ-butyrolactone, ethylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, ethylene carbonate, methyl ethyl carbonate, diethyl carbonate, γ-butyrolactone, ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, γ-butyrolactone, ethylene carbonate And Pyrene carbonate, dimethyl carbonate and methyl ethyl carbonate, γ-butyrolactone, ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, γ-butyrolactone, ethylene carbonate, propylene carbonate, methyl ethyl carbonate and diethyl carbonate, γ-butyrolactone and ethylene carbonate Propylene carbonate, dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate, γ-butyrolactone and sulfolane, γ-butyrolactone and ethylene carbonate and sulfolane, γ-butyrolactone and propylene carbonate and sulfolane, γ-butyrolactone, ethylene carbonate, propylene carbonate and sulfolane, γ -Butyrolactone and Su Such Horan and dimethyl carbonate.

The mixing ratio of the cyclic carboxylic acid ester in the nonaqueous solvent is 10% by mass to 100% by mass, more preferably 20% by mass to 90% by mass, and particularly preferably 30% by mass to 80% by mass. By setting it as such a ratio, the electroconductivity of the electrolyte solution relating to the charge / discharge characteristics of the battery can be increased.

Examples of cyclic sulfone include sulfolane, 2-methyl sulfolane, 3-methyl sulfolane, dimethyl sulfone, diethyl sulfone, dipropyl sulfone, methyl ethyl sulfone, methylpropyl sulfone and the like.

-Chain aprotic solvent-
Examples of the chain aprotic solvent include chain carbonates such as dimethyl carbonate, chain carboxylic acid esters such as methyl pivalate, chain ethers such as dimethoxyethane, and chain chains such as trimethyl phosphate. Examples include phosphate esters.

Specific examples of the chain carbonate include dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, ethyl propyl carbonate, dipropyl carbonate, methyl butyl carbonate, ethyl butyl carbonate, dibutyl carbonate, methyl pentyl carbonate, Examples include ethyl pentyl carbonate, dipentyl carbonate, methyl heptyl carbonate, ethyl heptyl carbonate, diheptyl carbonate, methyl hexyl carbonate, ethyl hexyl carbonate, dihexyl carbonate, methyl octyl carbonate, ethyl octyl carbonate, dioctyl carbonate, and methyltrifluoroethyl carbonate. These chain carbonates may be used in combination of two or more.

Specific examples of the chain carboxylic acid ester include methyl pivalate.
Specific examples of the chain ether include dimethoxyethane.
Specific examples of the chain phosphate ester include trimethyl phosphate.

The chain aprotic solvent can be mixed in order to improve the flash point of the solvent in order to improve the safety of the battery. Examples include chain carbonates, chain carboxylates, and chain phosphates. Particularly, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, diheptyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, methyl butyl. Chain carbonates such as carbonate and methyl heptyl carbonate are preferred.

-Combination of solvents-
The non-aqueous solvent in the present invention may be used alone or in combination. Further, only one or more types of cyclic aprotic solvents may be used, or only one or more types of chain aprotic solvents may be used, or cyclic aprotic solvents and chain proticity may be used. You may mix and use a solvent.
Among these, when it is particularly intended to improve the load characteristics and low temperature characteristics of the battery, it is desirable that the non-aqueous solvent is a combination of a cyclic aprotic solvent and a chain aprotic solvent. Furthermore, in view of the electrochemical stability of the electrolytic solution, it is most preferable to apply a cyclic carbonate to the cyclic aprotic solvent and a chain carbonate to the chain aprotic solvent. Further, the conductivity of the electrolytic solution related to the charge / discharge characteristics of the battery can be increased by a combination of the cyclic carboxylic acid ester and the cyclic carbonate and / or the chain carbonate.

As a combination of cyclic carbonate and chain carbonate, specifically, ethylene carbonate and dimethyl carbonate, ethylene carbonate and methyl ethyl carbonate, ethylene carbonate and diethyl carbonate, propylene carbonate and dimethyl carbonate, propylene carbonate and methyl ethyl carbonate, propylene carbonate and Diethyl carbonate, ethylene carbonate and propylene carbonate and methyl ethyl carbonate, ethylene carbonate and propylene carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate and methyl ethyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate, ethylene carbonate and methyl ethyl carbonate And diethyl carbonate, ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and methyl ethyl carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, ethylene carbonate, propylene carbonate and methyl ethyl Examples include carbonate and diethyl carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate.

The mixing ratio of the cyclic carbonate and the chain carbonate is expressed as a mass ratio, and cyclic carbonate: chain carbonate is 5:95 to 80 to 20, more preferably 10:90 to 70:30, and particularly preferably 15:85. ~ 55: 45. By setting it as such a ratio, since the raise of the viscosity of electrolyte solution can be suppressed and the dissociation degree of electrolyte can be raised, the conductivity of the electrolyte solution in connection with the charge / discharge characteristic of a battery can be raised. In addition, the solubility of the electrolyte can be further increased. Therefore, since it can be set as the electrolyte solution excellent in the electrical conductivity in normal temperature or low temperature, the load characteristic of the battery from normal temperature to low temperature can be improved.

-Other solvents-
The nonaqueous electrolytic solution according to the present invention may contain a solvent other than the above as a nonaqueous solvent. Specific examples of other solvents include amides such as dimethylformamide, chain carbamates such as methyl-N, N-dimethylcarbamate, cyclic amides such as N-methylpyrrolidone, N, N-dimethylimidazolidinone, and the like. Examples thereof include boron compounds such as cyclic urea, trimethyl borate, triethyl borate, tributyl borate, trioctyl borate, trimethylsilyl borate, and polyethylene glycol derivatives represented by the following general formula.
HO (CH ₂ CH ₂ O) _a H
HO [CH ₂ CH (CH ₃ ) O] _b H
CH ₃ O (CH ₂ CH ₂ O) _c H
CH ₃ O [CH ₂ CH (CH ₃ ) O] _d H
CH ₃ O (CH ₂ CH ₂ O) _e CH ₃
CH ₃ O [CH ₂ CH (CH ₃ ) O] _f CH ₃
_{_{_{_{C 9 H 19 PhO (CH 2}}}} CH 2 O) g [CH (CH 3) O] h CH 3
(Ph is a phenyl group)
CH ₃ O [CH ₂ CH (CH ₃ ) O] _i CO [OCH (CH ₃ ) CH ₂ ] _j OCH ₃

In the above formula, a to f are integers of 5 to 250, g to j are integers of 2 to 249, 5 ≦ g + h ≦ 250, and 5 ≦ i + j ≦ 250.

(Electrolytes)
The nonaqueous electrolytic solution of the present invention contains an electrolyte.
Various known electrolytes can be used as the electrolyte, and any electrolyte can be used as long as it is normally used as an electrolyte for a non-aqueous electrolyte. The electrolyte may be used alone or in combination of two or more.
Specific examples of the electrolyte include (C ₂ H ₅ ) ₄ NPF ₆ , (C ₂ H ₅ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NClO ₄ , (C ₂ H ₅ ) ₄ NAsF ₆ , (C ₂ H ₅ ) ₄ N ₂ SiF ₆ , (C ₂ H ₅ ) ₄ NOSO ₂ C _k F _{(2k + 1)} (k = 1 to 8), (C ₂ H ₅ ) ₄ NPF _n [C _k F _{(2k + 1)} ] _(6-n) Tetraalkylammonium salts such as (n = 1 to 5, k = 1 to 8), LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li ₂ SiF ₆ , LiOSO ₂ C _k F _And lithium salts such as _{(2k + 1)} (k = 1 to 8), LiPF _n [C _k F _{(2k + 1)} ] _(6-n) (n = 1 to 5, k = 1 to 8) . Moreover, the lithium salt represented by the following general formula can also be used.

LiC (SO ₂ R ⁷ ) (SO ₂ R ⁸ ) (SO ₂ R ⁹ ), LiN (SO ₂ OR ¹⁰ ) (SO ₂ OR ¹¹ ), LiN (SO ₂ R ¹² ) (SO ₂ R ¹³ ) (where R ⁷ to R ¹³ may be the same as or different from each other, and are perfluoroalkyl groups having 1 to 8 carbon atoms). These electrolytes may be used alone or in combination of two or more.

Of these, lithium salts are particularly desirable. Furthermore, LiPF ₆ , LiBF ₄ , LiOSO ₂ C _k F _{(2k + 1)} (k = 1 to 8), LiClO ₄ , LiAsF ₆ , LiNSO ₂ [C _k F _{( 2k + 1)} ] ₂ (k = 1 to 8), LiPF _n [C _k F _{(2k + 1)} ] _(6-n) (n = 1 to 5, k = 1 to 8).

The electrolyte in the present invention is usually preferably contained in the nonaqueous electrolyte at a concentration of 0.1 mol / liter to 3 mol / liter, preferably 0.5 mol / liter to 2 mol / liter.

In the nonaqueous electrolytic solution of the present invention, when a cyclic carboxylic acid ester such as γ-butyrolactone is used in combination as the nonaqueous solvent, it is particularly desirable to contain LiPF ₆ . Since LiPF ₆ has a high degree of dissociation, the conductivity of the electrolytic solution can be increased, and the reductive decomposition reaction of the electrolytic solution on the negative electrode can be suppressed. LiPF ₆ may be used alone, or LiPF ₆ and other electrolytes may be used. Any other electrolyte can be used as long as it is normally used as an electrolyte for a non-aqueous electrolyte, but lithium salts other than LiPF ₆ are preferred among the specific examples of the lithium salts described above. .
Specific examples include LiPF ₆ and LiBF ₄ , LiPF ₆ and LiN [SO ₂ C _k F _{(2k + 1)} ] ₂ (k = 1 to 8), LiPF ₆ and LiBF ₄ and LiN [SO ₂ C _k F _{( 2k + 1)} ] (k = 1 to 8).

The ratio of LiPF _{6 in} the lithium salt is 1% by mass to 100% by mass, preferably 10% by mass to 100% by mass, and more preferably 50% by mass to 100% by mass. Such an electrolyte is preferably contained in the non-aqueous electrolyte at a concentration of 0.1 mol / liter to 3 mol / liter, preferably 0.5 mol / liter to 2 mol / liter.

The non-aqueous electrolyte of the present invention is not only suitable as a non-aqueous electrolyte for a lithium secondary battery, but also a non-aqueous electrolyte for a primary battery, a non-aqueous electrolyte for an electrochemical capacitor, and an electric double layer capacitor. It can also be used as an electrolytic solution for aluminum electrolytic capacitors.

<Additive for lithium secondary battery>
The additive for lithium secondary batteries of this invention contains the compound represented by the said general formula (I).
The additive for a lithium secondary battery of the present invention suppresses an increase in battery resistance when used as an additive to be added to a non-aqueous electrolyte of a lithium secondary battery, and improves the storage characteristics of the battery in a high temperature environment. To do. Therefore, the lifetime of the lithium secondary battery can be extended by using the nonaqueous electrolytic solution containing the additive for lithium secondary battery of the present invention.

The additive for a lithium secondary battery of the present invention may be a single compound represented by the above general formula (I) or, if necessary, other components other than the compound represented by the general formula (I) May be included.
As other components, for example, from the viewpoint of obtaining the above effect more effectively, the compound represented by the general formula (II), the compound represented by the general formula (III), and the general formula (IV) At least one selected from the group consisting of compounds represented by

<Lithium secondary battery>
The lithium secondary battery of the present invention basically includes a negative electrode, a positive electrode, and the non-aqueous electrolyte, and a separator is usually provided between the negative electrode and the positive electrode.

(Negative electrode)
Examples of the negative electrode active material constituting the negative electrode include metallic lithium, lithium-containing alloys, metals that can be alloyed with lithium, alloys that can be alloyed with lithium, and oxides that can be doped / undoped with lithium ions. Further, at least one selected from transition metal nitrides capable of being doped / undoped with lithium ions and carbon materials capable of being doped / undoped with lithium ions can be used. Examples of metals or alloys that can be alloyed with lithium ions include silicon, silicon alloys, tin, and tin alloys.
Among these, a carbon material that can be doped / undoped with lithium ions is preferable as the negative electrode active material.
Examples of such carbon materials include carbon black, activated carbon, graphite materials (for example, artificial graphite, natural graphite, etc.), amorphous carbon materials, and the like.
Moreover, the form of the carbon material may be any of a fibrous form, a spherical form, a potato form, and a flake form.

Specific examples of the amorphous carbon material include hard carbon, coke, mesocarbon microbeads (MCMB) fired at 1500 ° C. or less, and mesopause bitch carbon fiber (MCF).
Examples of the graphite material include natural graphite and artificial graphite.
As the artificial graphite, graphitized MCMB, graphitized MCF, or the like is used. Further, as the graphite material, a graphite material containing boron can be used.
In addition, as the carbon material, a graphite material coated with a metal such as gold, platinum, silver, copper, or tin, or a graphite material coated with amorphous carbon can be used.
As the carbon material, a mixture of an amorphous carbon material and a graphite material can also be used.

These carbon materials may be used alone or in combination of two or more. The carbon material is particularly preferably a carbon material having a (002) plane spacing d (002) of 0.340 nm or less as measured by X-ray analysis, and a true density of 1.70 g / cm ³ or more or close to it. A highly crystalline carbon material having properties is preferred. When such a carbon material is used, the energy density of the battery can be increased.

(Positive electrode)
The positive electrode active material constituting the positive electrode in the present invention is a substance containing a transition metal that can be electrochemically doped / undoped with lithium ions, and a substance containing manganese as at least a part of the transition metal is used. It is done. Manganese is preferable as a positive electrode active material because it is inexpensive, easily available, and highly safe.
The positive electrode active material in the present invention is preferably a composite oxide in which 35 mol% or more of the contained transition metal is manganese.
The content of manganese in the transition metal is more preferably 50 mol% or more, and most preferably 80 mol or more. Thus, when there are many ratios of manganese to the transition metal in a positive electrode active material, it is preferable at the point which is economically low-cost.
Further, the composite oxide preferably contains lithium. Furthermore, the composite oxide is more preferably a composite oxide containing lithium and manganese.

Although there is no restriction | limiting in particular in the positive electrode active material containing said manganese, For example, the complex oxide represented by the following compositional formula (V) is preferable.
Li _x Mn _(1-y) M ¹ _y O ₂ composition formula (V)

In the composition formula (V), x is a number satisfying 0 <x ≦ 1.2, y is a number satisfying 0 ≦ y ≦ 0.65, M ¹ is Ni, Co, Al, Fe, Ti, Mg, Cr, At least one element selected from the group consisting of Ga, Cu, Zn, and Nb is shown.
In the composition formula (V), M ¹ is particularly preferably Ni, Co, or Fe, x is particularly preferably 0.2 ≦ x ≦ 1.15, and y is 0 ≦ y ≦ 0. 5 is particularly preferable, and y is most preferably 0 ≦ y ≦ 0.2.

Moreover, as said positive electrode active material containing manganese, the complex oxide represented by the following compositional formula (VI) is also preferable.
Li _x Mn _(2-y) M ² _y O ₄ composition formula (VI)

In the composition formula (VI), x is a number satisfying 0 <x ≦ 1.2, y is a number satisfying 0 ≦ y ≦ 1.3, M ² is Ni, Co, Al, Fe, Ti, Mg, Cr, At least one element selected from the group consisting of Ga, Cu, Zn, and Nb is shown.
In the composition formula (VI), M ² is particularly preferably Ni, Co, Al, Mg, x is particularly preferably 0.05 ≦ x ≦ 1.15, and y is 0 ≦ y ≦. 1 is particularly preferable, and y is most preferably 0 ≦ y ≦ 0.4.

Specific examples of the composite oxide represented by the composition formula (VI) include LiMn _1.8 Al _0.2 O ₄ and LiMn _1.5 Ni _0.5 O ₄ .

Said positive electrode active material may be used by 1 type, and may mix and use 2 or more types. When the positive electrode active material has insufficient conductivity, it can be used together with a conductive auxiliary agent to constitute a positive electrode.
Examples of the conductive assistant include carbon materials such as carbon black, amorphous whiskers, and graphite.

(Description of separator)
The separator in the present invention is a film that electrically insulates the positive electrode and the negative electrode and transmits lithium ions, and examples thereof include a porous film and a polymer electrolyte. A microporous polymer film is preferably used as the porous film, and examples of the material include polyolefin, polyimide, polyvinylidene fluoride, and polyester.
As the porous film, porous polyolefin is particularly preferable, and specific examples include a porous polyethylene film, a porous polypropylene film, or a multilayer film of a porous polyethylene film and a polypropylene film. On the porous polyolefin film, other resin excellent in thermal stability may be coated.
Examples of the polymer electrolyte include a polymer in which a lithium salt is dissolved, a polymer swollen with an electrolytic solution, and the like.
The nonaqueous electrolytic solution of the present invention may be used for the purpose of obtaining a polymer electrolyte by swelling a polymer.

(Battery configuration)
The lithium secondary battery of this invention contains the said negative electrode active material, a positive electrode active material, and a separator. The lithium secondary battery of the present invention can take various known shapes, and can be formed into a cylindrical shape, a coin shape, a square shape, a film shape, or any other shape. However, the basic structure of the battery is the same regardless of the shape, and the design can be changed according to the purpose.

An example of the lithium secondary battery of the present invention is a coin-type battery shown in FIG.
For example, in the coin-type battery shown in FIG. 1, a disc-shaped negative electrode 2, a separator 5 into which a non-aqueous electrolyte is injected, a disc-shaped positive electrode 1, and spacer plates 7 and 8 such as stainless steel or aluminum, if necessary, It is accommodated between the positive electrode can 3 and the sealing plate 4 in a state of being laminated in order. The positive electrode can 3 and the sealing plate 4 are caulked and sealed via a gasket 6.

The uses of the non-aqueous electrolyte, lithium secondary battery, and lithium secondary battery additive of the present invention are not particularly limited, and can be used for various known uses. For example, notebook computers, mobile computers, mobile phones, headphone stereos, video movies, LCD TVs, handy cleaners, electronic notebooks, calculators, radios, backup power applications, motors, automobiles, electric cars, motorcycles, electric bikes, bicycles, electric bicycles It can be widely used for lighting equipment, game machines, watches, electric tools, cameras, and the like.

Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples.

<Synthesis of Compound Represented by General Formula (I)>
Hereinafter, synthesis examples of the compound represented by the general formula (I) will be shown.
[Synthesis Example 1]
<Synthesis of methyl 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylate (Exemplary Compound 15)>
N-chlorosuccinimide (16.02 g, 0.120 mol) and pyridine (0.6 ml, 7.6 mmol) were dissolved in chloroform (108 ml), and 3-pyridinealdoxime (14.65 g, 81.2 mmol) was dissolved at room temperature. added. Although the temperature of the reaction liquid rose, it was heated to maintain 60 ° C. and stirred for 30 minutes. Thereafter, the temperature was kept at 45 ° C., methyl acrylate (12.91 g, 0.150 mol) was added dropwise, followed by triethylamine (12.74 g, 0.126 mol), and the mixture was stirred at 45 ° C. for 20 minutes. The reaction mixture was diluted with chloroform (72 ml), washed twice with water (180 ml), dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (eluent: hexane / ethyl acetate = 4/1) to give Exemplary Compound 15 (13.50 g, yield 55%). The results of NMR measurement of Exemplary Compound 15 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.84 (1H, d, J = 2.3), 8.68 (1H, dd, J = 2.0, 4.6), 8 .07 (1H, dt, J = 2.0, 7.9), 7.35 (1H, dd, J = 7.9, 4.6), 5.25 (1H, dd, J = 7.9) , 10.6), 3.84 (3H, s), 3.74-3.60 (2H, m)

[Synthesis Example 2]
<Synthesis of 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (Exemplary Compound 14)>
The methyl 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylate (8.45 g, 41 mmol) obtained above was dissolved in methanol (45 ml), and 1N NaOH was added at 30 ° C. Aqueous solution (45 ml, 45 mmol) was added and stirred for 30 minutes. After neutralizing with 1N aqueous hydrochloric acid (45 ml, 45 mmol) at room temperature, the reaction mixture was concentrated under reduced pressure. Water was added to the residue to make 52.5 g, heated to 80 ° C., and then gradually cooled to 15 ° C. The slurry-like product was filtered off, and the solid was washed twice with water (8 ml) and then dried under reduced pressure to give Exemplified Compound 14 (5.70 g, yield 72%) as pale yellow crystals. The results of NMR measurement of Exemplified Compound 14 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 13.20 (1H, brd.s), 8.88 (1H, d, J = 2.0), 8.66 (1H, dd, J = 1.6, 4.9), 8.10 (1H, dt, J = 7.9, 2.0), 7.50 (1H, dd, J = 7.9, 4.6), 5. 23 (1H, dd, J = 11.5, 7.2), 3.78 (1H, dd, J = 17.5, 11.5), 3.67 (1H, dd, J = 17.5, 6.9)

[Synthesis Example 3]
<Synthesis of methyl 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylate (Exemplary Compound 2)>
Exemplified compound 2 (6.24 g, 76%) was obtained in the same manner as in Synthesis Example 1, except that 3-pyridinealdoxime was changed to 2-pyridinealdoxime in Synthesis Example 1. The results of NMR measurement of Example Compound 2 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.62-8.60 (1H, m), 8.03 (1H, dt, J = 2.3, 1.4), 7.74 (1H, td, J = 7.9, 1.6), 7.35-7.28 (1H, m), 5.23 (1H, dd, J = 10.2, 8.9), 82 (3H, s), 3.84-3.78 (2H, m)

[Synthesis Example 4]
<Synthesis of 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylic acid (Exemplary Compound 1)>
In Synthesis Example 2, methyl 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylate was converted to 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylate. Exemplified Compound 1 (4.47 g, 78%) was obtained in the same manner as in Synthesis Example 2 except that the acid was changed to methyl acid. The results of NMR measurement of Exemplary Compound 1 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 13.26 (1H, brd.s), 8.66 (1H, dt, J = 4.9, 1.3), 7.96-7 .86 (2H, m), 7.51-7.46 (1H, m), 5.23 (1H, dd, J = 11.9, 6.9), 3.77 (1H, dd, 17. 8, 11.9), 3.61 (1H, dd, J = 17.8, 6.9)

[Synthesis Example 5]
<Synthesis of 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carbonitrile (Exemplary Compound 3)>
Exemplified Compound 3 (5.15 g, 74%) was synthesized in the same manner as in Synthesis Example 1 except that 3-pyridinealdoxime was changed to 2-pyridinealdoxime and methyl acrylate was changed to acrylonitrile in Synthesis Example 1. Obtained. The results of NMR measurement of Exemplary Compound 3 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.63 (1H, dd, J = 4.9, 1.0), 8.04-8.01 (1H, m), 7.78 (1H, dt, J = 1.6, 7.9), 7.39-7.35 (1H, m), 5.40 (1H, dd, J = 9.9, 7.2), 4. 02-3.85 (2H, m)

[Synthesis Example 6]
<Synthesis of 3-methyl-5- (pyridin-2-yl) -4,5-dihydroisoxazole (Exemplary Compound 28)>
Exemplified compound 28 (4.48 g, 55%) was synthesized in the same manner as in Synthesis Example 1 except that 3-pyridinealdoxime was changed to acetoaldoxime and methyl acrylate was changed to 2-vinylpyridine in Synthesis Example 1. Got. The results of NMR measurement of Exemplary Compound 28 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.57 (1H, ddd, J = 4.9, 1.6, 1.0), 7.71 (1H, dt, J = 1. 6, 7.6), 7.52 (1H, d, J = 7.9), 7.24-7.19 (1H, m), 5.65 (1H, dd, J = 10.9, 6 .6), 3.49-3.38 (1H, m), 3.25 (1H, ddd, J = 17.1, 6.9, 1.0), 2.02 (3H, d, 1. 0)

[Synthesis Example 7]
<Synthesis of 3-methyl-5- (pyridin-3-yl) -4,5-dihydroisoxazole (Exemplary Compound 31)>
Exemplified compound 31 (4.14 g, 64%) was prepared in the same manner as in Synthesis Example 1 except that 3-pyridinealdoxime was changed to acetoaldoxime and methyl acrylate was changed to 3-vinylpyridine in Synthesis Example 1. Got. The results of NMR measurement of Exemplary Compound 31 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.58-8.55 (2H, m), 7.69 (1H, dt, J = 7.9, 2.0), 7.30 (1H, ddd, 7.9, 4.9, 0.7), 5.59 (1H, dd, J = 10.6, 7.9), 3.49-3.38 (1H, m), 2.96-2.86 (1H, m), 2.04 (3H, d, J = 1.0)

[Synthesis Example 8]
<Synthesis of methyl 5-methyl-3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylate (Exemplary Compound 8)>
In the same manner as in Synthesis Example 1 except that 3-pyridinealdoxime was changed to 2-pyridinealdoxime and methyl acrylate was changed to methyl methacrylate in Synthesis Example 1, Exemplified Compound 8 (7.39 g, 84% ) The results of NMR measurement of Exemplified Compound 8 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.60 (1H, ddd, J = 4.9, 1.6, 1.0), 8.01 (1H, d, J = 7. 9), 7.73 (1H, dt, J = 1.6, 7.6), 7.32-7.28 (1H, m), 4.00 (1H, d, J = 17.8), 3.81 (3H, s), 3.40 (1H, d, J = 17.8), 1.73 (3H, s)

[Synthesis Example 9]
<Synthesis of methyl 5-phenyl-3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylate (Exemplary Compound 11)>
Exemplified compound 11 (2.34 g, 52%) was synthesized in the same manner as in Synthesis Example 1 except that 3-pyridinealdoxime was changed to 2-pyridinealdoxime and methyl acrylate was changed to styrene in Synthesis Example 1. Obtained. The result of NMR measurement of Exemplified Compound 11 is shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.59 (1H, ddd, J = 4.9, 2.0, 1.0), 8.07 (1H, dt, J = 7. 9, 1.0), 7.73 (1H, dt, J = 1.6, 7.6), 7.43-7.26 (6H, m), 5.79 (1H, dd, J = 11 .2, 8.2), 3.93 (1H, dd, J = 17.5, 10.9), 3.53 (1H, dd, J = 17.5, 8.6)

[Synthesis Example 10]
<Synthesis of 5-butoxy-3- (pyridin-3-yl) -4,5-dihydroisoxazole (Exemplary Compound 16)>
Exemplified compound 16 (14.76 g, 67%) was obtained in the same manner as in Synthesis Example 1 except that methyl acrylate was changed to butyl vinyl ether in Synthesis Example 1. The results of NMR measurement of Exemplified Compound 16 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.84 (1H, d, J = 2.0), 8.65 (1H, dd, J = 4.6, 1.6), 8 .08 (1H, dt, J = 7.9, 2.0), 7.35 (1H, dd, J = 8.2, 4.9), 5.72 (1H, dd, J = 6.6) 1.6, 3.92-3.84 (1H, m), 3.60-3.52 (1H, m), 3.40 (1H, dd, J = 17.1, 6.1) , 3.23 (1H, dd, J = 17.1, 2.0), 1.63-1.53 (2H, m), 1.44-1.30 (2H, m), 0.92 ( 3H, t, J = 7.2)

[Synthesis Example 11]
<Synthesis of 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carbonitrile (Exemplary Compound 21)>
Exemplified compound 21 (4.78 g, 46%) was obtained in the same manner as in Synthetic Example 1, except that methyl acrylate was changed to acrylonitrile in Synthetic Example 1. The results of NMR measurement of Exemplary Compound 21 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.83 (1H, d, J = 2.0), 8.72 (1H, dd, J = 4.9, 1.6), 8 .06 (1H, dt, J = 7.9, 1.6), 7.41 (1H, dd, J = 8.2, 4.9), 5.44 (1H, dd, J = 10.2) 6.9), 3.88-3.73 (2H, m)

[Synthesis Example 12]
<Synthesis of methyl 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5-carboxylate (Exemplary Compound 23)>
Exemplified compound 23 (1.20 g, 29%) was obtained in the same manner as in Synthesis Example 1 except that 3-pyridinealdoxime was changed to 4-pyridinealdoxime in Synthesis Example 1. The results of NMR measurement of Exemplary Compound 23 are shown below.

¹ H-NMR (270 MHz, CDCl ₃ ) δ (ppm): 8.70 (1H, dd, J = 4.6, 1.6), 7.54 (1H, dd, J = 4.6) 6), 5.27 (1H, dd, J = 10.6, 7.9), 3.84 (3H, s), 3.89-3.60 (2H, m)

As described above, as examples of synthesis of the compound represented by the general formula (I), Exemplified Compound 15, Exemplified Compound 14, Exemplified Compound 2, Exemplified Compound 1, Exemplified Compound 3, Exemplified Compound 28, Exemplified Compound 31, Exemplified Compound 8, Exemplified Although the synthesis example of the compound 11, the example compound 16, the example compound 21, and the example compound 23 was demonstrated, it can synthesize | combine by the method similar to the said synthesis example also about the compound represented with general formula (I) other than the above.

[Evaluation methods]
<Initial characteristic evaluation>
The produced test battery was charged at a constant current of 1 mA and a constant voltage of 4.2 V, and discharged to 2.85 V at a constant current of 1 mA for 10 cycles.
At that time, the first charge / discharge efficiency was calculated by the following equation from the charge capacity [mAH] and discharge capacity [mAH] of the first cycle.

Initial charge / discharge efficiency [%]
= 1st cycle discharge capacity [mAH] / 1st cycle charge capacity [mAH] x 100 [%]

Further, the battery was charged with a constant voltage of 4.0 V, and the battery was cooled to −10 ° C. in a thermostat using a Solartron, and impedance measurement was performed.
The initial charge / discharge efficiency and impedance measurement were used as initial characteristic evaluation.
In Examples 1 to 25 and Comparative Examples 1 to 7 described below, the evaluation results were omitted because the evaluation results had no practical problems with respect to the initial characteristic evaluation.

<High temperature storage test>
After the impedance measurement, the test battery was charged at a constant current of 1 mA and a constant voltage of 4.2 V in a constant temperature bath at 25 ° C., and discharged to 2.85 V at a constant current of 1 mA in the constant temperature bath at 25 ° C. The discharge capacity [mAh] before storage was measured.
Next, the test battery was charged with a constant current of 1 mA and a constant voltage of 4.2 V in a thermostatic bath at 25 ° C., and then the temperature of the thermostatic bath was raised to 80 ° C. The test battery was stored for 2 days (high temperature storage).
After the high-temperature storage, the temperature of the thermostat is returned to 25 ° C., and the test battery is discharged to 2.85 V at a constant current of 1 mA in the thermostatic bath at 25 ° C., and the remaining discharge capacity [mAh] ( That is, the discharge capacity [mAh] after storage at high temperature was measured.
And the capacity | capacitance maintenance factor before and behind high temperature storage was computed with the following formula.

Capacity maintenance rate before and after high temperature storage [%]
= (Discharge capacity after storage at high temperature [mAh] / Discharge capacity before storage at high temperature [mAh]) × 100 [%]

[Example 1]
<Production of negative electrode>
20 parts by mass of artificial graphite, 80 parts by mass of natural graphite, 1 part by mass of carboxymethyl cellulose and 2 parts by mass of SBR latex were kneaded with an aqueous solvent to prepare a paste-like negative electrode mixture slurry.
Next, this negative electrode mixture slurry was applied to a negative electrode current collector made of a strip-shaped copper foil having a thickness of 18 μm, dried, and then compressed by a roll press to form a sheet-like material comprising a negative electrode current collector and a negative electrode active material layer. A negative electrode was obtained. The coating density of the negative electrode active material layer at this time was 10 mg / cm ² , and the packing density was 1.5 g / ml.

<Preparation of positive electrode>
90 parts by mass of LiMn ₂ O ₄ , 5 parts by mass of acetylene black and 5 parts by mass of polyvinylidene fluoride were kneaded using N-methylpyrrolidinone as a solvent to prepare a paste-like positive electrode mixture slurry.
Next, this positive electrode mixture slurry is applied to a positive electrode current collector made of a strip-shaped aluminum foil having a thickness of 20 μm, dried, and then compressed by a roll press to form a sheet-like positive electrode comprising a positive electrode current collector and a positive electrode active material. Obtained. The coating density of the positive electrode active material layer at this time was 30 mg / cm ² , and the packing density was 2.5 g / ml.

<Preparation of non-aqueous electrolyte>
As a non-aqueous solvent, ethylene carbonate (EC), dimethyl carbonate (DMC), and methyl ethyl carbonate (EMC) were mixed at a ratio of 34:33:33 (mass ratio), respectively.
In the obtained mixed solvent, LiPF ₆ as an electrolyte was dissolved so that the electrolyte concentration in the total amount of the non-aqueous electrolyte finally prepared was 1 mol / liter.
With respect to the solution obtained above, 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (addition) which is a compound represented by the general formula (I) is used as an additive. Agent A (Exemplary Compound 14)) was added so that the content in the total amount of the nonaqueous electrolyte finally prepared was 0.5% by mass to obtain a nonaqueous electrolyte.
The 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid is a compound in which Q in the general formula (I) corresponds to an isoxazolinyl group.

<Production of coin-type battery>
The above-mentioned negative electrode was 14 mm in diameter and the above-mentioned positive electrode was 13 mm in diameter, and each was punched into a disk shape to obtain coin-shaped electrodes (negative electrode and positive electrode). Further, a microporous polyethylene film having a thickness of 20 μm was punched into a disk shape having a diameter of 17 mm to obtain a separator.
The obtained coin-shaped negative electrode, separator, and coin-shaped positive electrode were laminated in this order in a stainless steel battery can (2032 size), and 20 μl of the non-aqueous electrolyte obtained above was injected to separate the separator and the positive electrode. And the negative electrode.
Further, an aluminum plate (thickness 1.2 mm, diameter 16 mm) and a spring are placed on the positive electrode, and the battery is sealed by caulking the battery can lid through a polypropylene gasket, and the diameter is 20 mm, height. A 3.2 mm coin-type battery (test battery) was produced.
The obtained coin-type battery (test battery) was subjected to initial characteristic evaluation and a high-temperature storage test.

[Example 2]
Instead of 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A), 3- (pyridin-2-yl) -isoxazole-5-carbonitrile ( Coin type in the same manner as in Example 1 except that Additive B (Exemplary Compound 3)) was added so that the content in the total amount of the non-aqueous electrolyte finally prepared was 0.5% by mass. A battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.
The above 3- (pyridin-2-yl) -isoxazole-5-carbonitrile has the same meaning as 3- (pyridin-2-yl) -5-cyano-isoxazole.

[Example 3]
Instead of 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A), 3- (pyridin-2-yl) -isoxazole (additive C (example) A coin-type battery was obtained in the same manner as in Example 1 except that the compound 34)) was added so that the content in the total amount of the non-aqueous electrolyte finally prepared was 0.5% by mass.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 4]
Instead of 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A), 3- (pyridin-3-yl) -isoxazole (additive D (example) A coin-type battery was obtained in the same manner as in Example 1 except that the compound 37)) was added so that the content in the total amount of the non-aqueous electrolyte finally prepared was 0.5% by mass.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 5]
Instead of the 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A), 3- (pyridin-4-yl) -isoxazole (additive E (example) A coin-type battery was obtained in the same manner as in Example 1 except that the compound 42)) was added so that the content in the total amount of the non-aqueous electrolyte finally prepared was 0.5% by mass.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 6]
As additives, 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A) and 1,3-prop-1-ene sultone (PRS) are finally added. A coin-type battery was obtained in the same manner as in Example 1, except that each content was 0.5% by mass in the total amount of the prepared non-aqueous electrolyte.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 7]
As additives, 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A), 1,3-prop-1-ene sultone (PRS), and vinylene carbonate (VC ) Was added in the same manner as in Example 1 except that each content was 0.5% by mass in the total amount of the non-aqueous electrolyte finally prepared.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Comparative Example 1]
A coin-type battery was obtained in the same manner as in Example 1 except that no additive was added as the non-aqueous electrolyte.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Comparative Example 2]
In place of the 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (Additive A), the content of pyridine in the total amount of the non-aqueous electrolyte finally prepared A coin-type battery was obtained in the same manner as in Example 1 except that the amount was 0.5% by mass.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Comparative Example 3]
Instead of the 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A), 2-chloro-pyridine was used as the total amount of the non-aqueous electrolyte finally prepared. A coin-type battery was obtained in the same manner as in Example 1 except that the content was 0.5% by mass.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Comparative Example 4]
Content of bipyridine instead of 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A) in the total amount of the non-aqueous electrolyte finally prepared A coin-type battery was obtained in the same manner as in Example 1 except that the amount was 0.5% by mass.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Comparative Example 5]
Instead of the 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-carboxylic acid (additive A), 2,6-di-tert-butyl-4-methylpyridine is used as a final product. A coin-type battery was obtained in the same manner as in Example 1 except that the content was 0.5% by mass in the total amount of the non-aqueous electrolyte prepared.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

Table 1 shows the evaluation results of the high temperature storage tests of Examples 1 to 7 and Comparative Examples 1 to 5.

When Examples 1 to 7 and Comparative Example 1 are compared, the high temperature storage characteristics of the lithium secondary battery can be improved by adding the compound represented by the general formula (I) as an additive to the non-aqueous electrolyte. You can see that
Further, when Examples 1 to 7 and Comparative Examples 2 to 5 are compared, the addition of the compound represented by the general formula (I) as an additive is compared with the case of adding another additive having a pyridine skeleton. It can be seen that the high-temperature storage characteristics can be improved.
Further, Examples 6 and 7 in which the compound represented by the general formula (I) and the compound represented by the general formula (II) were used in combination as an additive (particularly, in addition to these, the general formula (III) In Example 7) using the compound represented by), it was revealed that the high-temperature storage characteristics can be further improved.

Next, a coin-type battery was produced in the same manner as in Example 1 except that the type of additive was changed as shown in Table 2 or Table 3 described later, and the same evaluation as in Example 1 was performed (implementation). Examples 8 to 25, comparative examples 6 to 7).
Details of Examples 8 to 25 and Comparative Examples 6 to 7 will be described below.

[Example 8]
Except that Exemplified Compound 14 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 9]
Except that Exemplified Compound 15 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 10]
Example Except that Exemplified Compound 21 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5 mass%. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 11]
Except that Exemplified Compound 41 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 12]
Example Except that Exemplified Compound 37 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5 mass%. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 13]
Except that Exemplified Compound 1 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5 mass%, Examples In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 14]
Except that Exemplified Compound 38 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5 mass%, Examples In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 15]
Except that Exemplified Compound 23 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 16]
Example Except that Exemplified Compound 16 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5 mass%. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 17]
Example Except that Exemplified Compound 6 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5 mass%. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 18]
Except that Exemplified Compound 8 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 19]
Except that Exemplified Compound 11 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 20]
Example Except that Exemplified Compound 28 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5 mass%. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 21]
Except that Exemplified Compound 31 and vinylene carbonate (VC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. In the same manner as in Example 1, a coin-type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 22]
As an additive, except that Exemplified Compound 14 and 4-fluoroethylene carbonate (FEC) were added so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. Obtained a coin-type battery in the same manner as in Example 1.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 23]
As an additive, Example Compound 14 and 4,5-difluoroethylene carbonate (DFEC) were added so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. A coin-type battery was obtained in the same manner as in Example 1 except that.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 24]
Except that Exemplified Compound 15 and 4-fluoroethylene carbonate (FEC) were added as additives so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. Obtained a coin-type battery in the same manner as in Example 1.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Example 25]
As an additive, Exemplified Compound 15 and 4,5-difluoroethylene carbonate (DFEC) were added so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. A coin-type battery was obtained in the same manner as in Example 1 except that.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Comparative Example 6]
As an additive, vinylene carbonate (VC) was coin-shaped in the same manner as in Example 1 except that vinylene carbonate (VC) was added so that the content in the final amount of the non-aqueous electrolyte was 0.5% by mass. A battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

[Comparative Example 7]
A coin was formed in the same manner as in Example 1 except that bipyridine and vinylene carbonate (VC) were added so that the respective contents in the total amount of the non-aqueous electrolyte finally prepared were 0.5% by mass. A type battery was obtained.
About the obtained coin-type battery, initial characteristic evaluation and a high temperature storage test were implemented.

Tables 2 and 3 show the evaluation results of the high temperature storage tests of Examples 8 to 25 and Comparative Examples 6 to 7.
Further, for comparison, the evaluation results of Comparative Example 1 shown in Table 1 are shown in Table 3 again.

As shown in Tables 2 and 3, also in Examples 8 to 25, the capacity retention rate before and after high temperature storage was higher than in each comparative example, and the storage characteristics of the battery in a high temperature environment were excellent.

The disclosure of Japanese application 2008-287055 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims

A nonaqueous electrolytic solution for a lithium secondary battery containing a compound represented by the following general formula (I).

[In general formula (I), Py represents a pyridyl group which may be substituted with 1 to 3 substituents selected from Group A below.
Group A includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Alkoxy group, alkenyloxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkylsulfonyl having 1 to 8 carbon atoms Group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom Or bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms to form a 3- to 7-membered ring, a phenyloxy group (halogen atom or alkyl having 1 to 6 carbon atoms) Set by group Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (the carbon number of the alkyl group) Are 1 to 8), N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly or oxygen atom, sulfur Via a nitrogen atom substituted with an atom or an alkyl group having 1 to 6 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or alkyl having 1 to 6 carbon atoms) An aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon number). It is substituted with an alkyl group having 1-6 a group consisting also be).
n represents 1 or 2.
Q represents an aromatic or non-aromatic 5-membered heterocyclic group which may contain 1 to 4 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom, and the heterocyclic ring is selected from the following group B May be substituted by 1 to 2 substituents.
Group B includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Alkoxy group, alkenyloxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkylsulfonyl having 1 to 8 carbon atoms Group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom Or bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms to form a 3- to 7-membered ring, a phenyloxy group (halogen atom or alkyl having 1 to 6 carbon atoms) Set by group Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (the carbon number of the alkyl group) Are 1 to 8), N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly or oxygen atom, sulfur Via a nitrogen atom substituted with an atom or an alkyl group having 1 to 6 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or alkyl having 1 to 6 carbon atoms) An aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon number). It is substituted with an alkyl group having 1-6 a group consisting also be). ]
Q in the general formula (I) is a furyl group, thienyl group, pyrrolyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, pyrazolyl group, 1,2,4-oxadiazolyl group, 1,3, The nonaqueous electrolytic solution according to claim 1, which is a 4-oxadiazolyl group, an oxazolinyl group, an isoxazolinyl group, an imidazolinyl group, or a pyrazolinyl group.
Q in the general formula (I) is an isoxazol-3-yl group, an isoxazolin-3-yl group, an isoxazolin-5-yl group, or a 1,2,4-oxadiazol-5-yl group. The nonaqueous electrolytic solution according to claim 1.
The compound represented by the general formula (I) is 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carboxylic acid, 3- (pyridin-3-yl) -4,5- Dihydroisoxazole-5-carboxylic acid, 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5-carboxylic acid, 3- (pyridin-2-yl) -4,5-dihydroisoxazole- Methyl 5-carboxylate, 3- (pyridin-3-yl) -4,5-dihydroisoxazole-5-methyl carboxylate, 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5- Methyl carboxylate, 3- (pyridin-2-yl) -4,5-dihydroisoxazole-5-carbonitrile, 3- (pyridin-3-yl) -4,5-dihydroisoxazole- 5-carbonitrile, 3- (pyridin-4-yl) -4,5-dihydroisoxazole-5-carbonitrile, 3- (pyridin-2-yl) -isoxazole-5-carbonitrile, 3- (pyridine -3-yl) -isoxazole-5-carbonitrile, 3- (pyridin-4-yl) -isoxazole-5-carbonitrile, 3- (pyridin-2-yl) -isoxazole-5-carboxylic acid, 3- (pyridin-3-yl) -isoxazole-5-carboxylic acid, 3- (pyridin-4-yl) -isoxazole-5-carboxylic acid, 3- (pyridin-2-yl) -isoxazole-5 -Methyl carboxylate, 3- (pyridin-3-yl) -isoxazole-5-carboxylate, 3- (pyridin-4-yl) -isoxazole Methyl 5-carboxylate, 3- (pyridin-2-yl) -isoxazole, 3- (pyridin-3-yl) -isoxazole, 3- (pyridin-4-yl) -isoxazole, 3- (pyridine- 2-yl) -1,2,4-oxadiazole, 3- (pyridin-3-yl) -1,2,4-oxadiazole, 3- (pyridin-4-yl) -1,2,4 -Oxadiazole, 3-methyl-5- (pyridin-2-yl) -4,5-dihydroisoxazole, ethyl 5- (pyridin-2-yl) -4,5-dihydroisoxazole-3-carboxylate 5- (pyridin-2-yl) -4,5-dihydroisoxazole-3-carbonitrile, 3-methyl-5- (pyridin-3-yl) -4,5-dihydroisoxazole, 5- (pyridine - The non-ethylated group according to claim 1, which is ethyl-yl) -4,5-dihydroisoxazole-3-carboxylate or 5- (pyridin-3-yl) -4,5-dihydroisoxazole-3-carbonitrile. Water electrolyte.
Furthermore, the non-aqueous electrolyte of Claim 1 containing the compound represented with the following general formula (II).

[In General Formula (II), R 1 , R 2 , R 3 , and R 4 are each independently an alkyl group having 1 to 12 carbon atoms, a hydrogen atom, or a fluorine atom that may be substituted with a fluorine atom. And m represents an integer of 0 to 3. When m is 2 or 3, a plurality of R 3 and R 4 may be the same or different from each other. ]
The nonaqueous electrolytic solution according to claim 5, wherein the content of the compound represented by the general formula (II) is 0.001 mass% to 10 mass%.
Furthermore, the non-aqueous electrolyte of Claim 1 containing the compound represented by the following general formula (III).

[In General Formula (III), R 5 and R 6 each independently represent a hydrogen atom, a methyl group, an ethyl group, or a propyl group. ]
The nonaqueous electrolytic solution according to claim 7, wherein the content of the compound represented by the general formula (III) is 0.001% by mass to 10% by mass.
Furthermore, the non-aqueous electrolyte of Claim 1 containing the compound represented by the following general formula (IV).

[In the general formula (IV), X 1 , X 2 , X 3 and X 4 are each independently an alkyl group having 1 to 3 carbon atoms which may be substituted with a fluorine atom, a hydrogen atom, a fluorine atom, or chlorine. Indicates an atom. However, the case where X 1 , X 2 , X 3 and X 4 are hydrogen atoms at the same time is excluded. ]
The nonaqueous electrolytic solution according to claim 9, wherein the content of the compound represented by the general formula (IV) is 0.001% by mass to 10% by mass.
The nonaqueous electrolytic solution according to claim 1, wherein the content of the compound represented by the general formula (I) is 0.001 mass% to 10 mass%.
A positive electrode;
Metallic lithium, lithium-containing alloys, metals that can be alloyed with lithium, alloys that can be alloyed with lithium, oxides that can be doped / undoped with lithium ions, and metals that can be doped / undoped with lithium ions A negative electrode containing, as a negative electrode active material, at least one selected from transition metal nitrides and carbon materials capable of doping and dedoping lithium ions;
A non-aqueous electrolyte according to claim 1;
A lithium secondary battery.
The additive for lithium secondary batteries containing the compound represented by the following general formula (I).

[In general formula (I), Py represents a pyridyl group which may be substituted with 1 to 3 substituents selected from Group A below.
Group A includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Alkoxy group, alkenyloxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkylsulfonyl having 1 to 8 carbon atoms Group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom Or bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms to form a 3- to 7-membered ring, a phenyloxy group (halogen atom or alkyl having 1 to 6 carbon atoms) Set by group Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (the carbon number of the alkyl group) Are 1 to 8), N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly or oxygen atom, sulfur Via a nitrogen atom substituted with an atom or an alkyl group having 1 to 6 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or alkyl having 1 to 6 carbon atoms) An aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon number). It is substituted with an alkyl group having 1-6 a group consisting also be).
n represents 1 or 2.
Q represents an aromatic or non-aromatic 5-membered heterocyclic group which may contain 1 to 4 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom, and the heterocyclic ring is selected from the following group B May be substituted by 1 to 2 substituents.
Group B includes a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an alkyl group having 1 to 8 carbon atoms. Alkoxy group, alkenyloxy group having 2 to 6 carbon atoms, alkynyloxy group having 2 to 6 carbon atoms, alkylthio group having 1 to 8 carbon atoms, alkylsulfinyl group having 1 to 8 carbon atoms, alkylsulfonyl having 1 to 8 carbon atoms Group, an alkylamino group having 1 to 8 carbon atoms, and a dialkylamino group (the carbon numbers of the two alkyl groups are each independently 1 to 8. The two alkyl groups are directly, oxygen atom, sulfur atom Or bonded to each other through a nitrogen atom substituted with an alkyl group having 1 to 6 carbon atoms to form a 3- to 7-membered ring, a phenyloxy group (halogen atom or alkyl having 1 to 6 carbon atoms) Set by group Nitro group, formyl group, cyano group, carboxyl group, alkoxycarbonyl group (the alkyl group has 1 to 8 carbon atoms), carbamoyl group, N-alkylaminocarbonyl group (the carbon number of the alkyl group) Are 1 to 8), N, N-dialkylaminocarbonyl group (the number of carbon atoms of the two alkyl groups is each independently 1 to 8. The two alkyl groups are directly or oxygen atom, sulfur Via a nitrogen atom substituted with an atom or an alkyl group having 1 to 6 carbon atoms, which may be bonded to each other to form a 3- to 7-membered ring, a phenyl group (halogen atom or alkyl having 1 to 6 carbon atoms) An aromatic 5-membered heterocyclic group (which may be substituted with a halogen atom or an alkyl group having 1 to 6 carbon atoms), and an aromatic 6-membered heterocyclic group (a halogen atom or carbon number). It is substituted with an alkyl group having 1-6 a group consisting also be). ]