JP5976490B2 - Battery electrode and battery using the same - Google Patents

Description

  The present invention relates to a battery electrode and a battery using the same.

  A battery such as a lithium ion secondary battery is used as a power source for a mobile phone, a personal computer, a power source for an automobile, and the like. In addition, in the battery used for such applications, research aimed at improving various characteristics such as ensuring safety, improving cycle characteristics and increasing output has been repeated.

  For example, in Patent Document 1, as a technique for preventing the thermal runaway from reacting with the positive / negative active material and the organic electrolyte in the battery due to the battery temperature increase due to overcharging of the nonaqueous electrolyte secondary battery, A technique is disclosed in which a reaction inhibitor composed of a redox agent or a radical scavenger is contained in the outermost periphery of the positive electrode or electrode body. Moreover, in patent document 2, the malfunction in a manufacturing process by the rise in electrolyte viscosity which is a problem at the time of improving the high output characteristic of a battery and cycling characteristics by use of a high concentration electrolyte, and the liquid permeability fall to an electrode plate. In order to suppress variation in quality, a technique in which a part of a lithium salt added to an electrolytic solution is supported on a positive electrode in advance is disclosed.

JP 2003-282063 A JP 2011-192561 A

  As described above, various studies have been made on improving battery characteristics. Further, the battery is required to have a long life and to stabilize the cycle characteristics. However, as the battery application spreads, the battery is required to have a higher energy density. In order to increase the energy density of the battery, it is necessary to drive the battery under a high voltage. However, driving of the battery under a high voltage promotes oxidative decomposition of the solvent contained in the electrolytic solution, resulting in deterioration of cycle characteristics.

  The present invention has been made by paying attention to the above-described circumstances, and its purpose is to prevent deterioration of characteristics such as discharge capacity over time, and in particular, cycle characteristics even when driven under high voltage. An object of the present invention is to provide an improved battery electrode and a battery using the same.

The battery electrode of the present invention that has achieved the above-mentioned object has a gist in that it contains a compound represented by the following general formula (1) (hereinafter referred to as compound (1)).
M ^{n +} ([B (CN) _4−m Y _m ] ⁻ ) _n (1)
(In the formula, M ^{n +} represents H ⁺ , monovalent, divalent, or trivalent organic or inorganic cation, and Y represents a halogen having 1 to 10 carbon atoms in the main chain which may have halogen. Represents a hydrocarbon group, —C (O) R ¹⁴ , —S (O) ₁ R ¹⁴ , —Z (R ¹⁴ ) ₂ , —SR ¹⁴ or —OR ¹⁵ , wherein R ¹⁴ represents H, halogen, or the main chain; Represents an organic substituent having 1 to 10 atoms, Z represents N or P, R ¹⁵ represents an alkylsilyl group having 1 to 10 carbon atoms, an alkanoyl group having 1 to 10 carbon atoms, a halosulfinyl group, a halogen atom. 1 represents an alkylsulfinyl group having 1 to 10 carbon atoms, a halosulfonyl group, or an alkylsulfonyl group having 1 to 10 carbon atoms that may have a halogen, and l is an integer of 1 to 2 M represents an integer of 1 to 3, and n represents an integer of 1 to 3.)

  The compound is preferably a compound represented by the following general formula (2) (hereinafter referred to as compound (2)).

(In the formula, M ^{n +} represents H ⁺ , monovalent, divalent, or trivalent organic or inorganic cation, and Y ′ represents carbon atoms of the main chain which may have H, halogen, or halogen. 10 represents a hydrocarbon group, a cyano group, —C (O) R ¹⁴ , —S (O) ₁ R ¹⁴ , Z (R ¹⁴ ) ₂ or —XR ¹⁴ , wherein R ¹⁴ represents H, halogen, or the main chain Represents an organic substituent having 1 to 10 atoms, Z represents N or P, X represents O or S, l represents an integer of 1 to 2, n represents an integer of 1 to 3, p represents an integer of 0 to 10.)

  The compound (1) or (2) contained in the battery electrode of the present invention is expected to be appropriately decomposed when the battery is driven, and a film is formed on the electrode surface by the decomposition products and the compounds (1) and (2). As a result, it is considered that the decomposition of the solvent, the supporting salt (electrolyte) and the like is suppressed, and a stable capacity maintaining action (high cycle characteristics) is exhibited without impairing the performance of the supporting salt.

  In the present invention, the electrode is preferably used as a positive electrode of a battery.

  The present invention also includes a battery including an electrode containing the general formula (1) or (2). The electrode is preferably a positive electrode. The battery of the present invention is preferably a lithium ion secondary battery.

  According to the present invention, since the battery electrode contains the compound represented by the general formula (1) and / or (2), the battery electrode is excellent in cycle characteristics, and in particular, even if driven at a high voltage over time. It is possible to expect a battery that does not easily deteriorate in characteristics and can be driven stably.

FIG. 1 is a graph showing the results of a cycle test (relationship between the number of cycles and discharge capacity) in Examples.

The battery electrode of the present invention is characterized in that it contains a compound represented by the following general formula (1) or (2).
M ^{n +} ([B (CN) _4−m Y _m ] ⁻ ) _n (1)
(In the formula, M ^{n +} represents H ⁺ , monovalent, divalent, or trivalent organic or inorganic cation, and Y represents a halogen having 1 to 10 carbon atoms in the main chain which may have halogen. Represents a hydrocarbon group, —C (O) R ¹⁴ , —S (O) ₁ R ¹⁴ , —Z (R ¹⁴ ) ₂ , —SR ¹⁴ or —OR ¹⁵ , wherein R ¹⁴ represents H, halogen, or the main chain; Represents an organic substituent having 1 to 10 atoms, Z represents N or P, R ¹⁵ represents an alkylsilyl group having 1 to 10 carbon atoms, an alkanoyl group having 1 to 10 carbon atoms, a halosulfinyl group, a halogen atom. 1 represents an alkylsulfinyl group having 1 to 10 carbon atoms, a halosulfonyl group, or an alkylsulfonyl group having 1 to 10 carbon atoms that may have a halogen, and l is an integer of 1 to 2 M represents an integer of 1 to 3, and n represents an integer of 1 to 3.)

(In the formula, M ^{n +} represents H ⁺ , monovalent, divalent, or trivalent organic or inorganic cation, and Y ′ represents carbon atoms of the main chain which may have H, halogen, or halogen. 10 represents a hydrocarbon group, a cyano group, —C (O) R ¹⁴ , —S (O) ₁ R ¹⁴ , Z (R ¹⁴ ) ₂ or —XR ¹⁴ , wherein R ¹⁴ represents H, halogen, or the main chain Represents an organic substituent having 1 to 10 atoms, Z represents N or P, X represents O or S, l represents an integer of 1 to 2, n represents an integer of 1 to 3, p represents an integer of 0 to 10.)

  The inventors include a compound in which the battery electrode is represented by the general formula (1) or (2) (hereinafter, the compounds (1) and (2) may be collectively referred to as a cyanoborate compound). In this case, the initial discharge capacity of the battery is increased, the discharge capacity is not easily lowered with time, and the cycle characteristics are excellent, and the present invention has been completed.

  When the battery electrode contains the compound (1) or (2), the clear reason why the above-described characteristics improvement effect is obtained has not been clarified, but the present inventors consider as follows. .

  As described above, the compound (1) or (2) contained in the battery electrode is expected to be appropriately decomposed when the battery is driven. And, by the formation of a film on the electrode surface by the decomposition products and compounds (1) and (2) generated at this time, decomposition of the solvent, supporting salt (electrolyte), etc. is suppressed, and the performance of the supporting salt is impaired. It is considered that a stable capacity maintaining action (high cycle characteristics) is exhibited.

  Moreover, it is thought that the said film contains a cyano group. Similarly to the case where the oxidation potential of the compounds (1) and (2) is increased by containing the cyano group, the film containing the cyano group is considered to have a high oxidation potential, and the compounds (1), (2) and the above-mentioned The film is difficult to oxidatively decompose even when exposed to a high voltage. As a result, the compounds (1) and (2) eluted from the electrode are stably present in the electrolytic solution. That is, the compounds (1) and (2) are gradually released from the electrode, and after being stably present in the electrolytic solution for a certain period of time, they are gradually decomposed, whereby a film is continuously formed on the electrode surface. It is expected that Thus, the film is continuously formed on the surface of the electrode, so that the stability of the electrode is improved. As a result, the positive electrode additive (for example, VC, FEC, ES, 1,3-PS, etc.) Degradation at the finest is suppressed, and further improvement in battery performance is expected. Moreover, it is thought that the oxidative decomposition of a conventionally known solvent is also suppressed for the same reason, and it has excellent characteristics such as easy dissolution of electrolyte and high dielectric constant, but is easily reduced (PC, GBL, etc.) It can also be expected that the performance of the battery will be prevented from lowering when used as an electrolyte.

  Further, the oxidation potential of the compound (1) or (2) according to the present invention can be freely adjusted by appropriately selecting the substituents Y and Y ′. Therefore, if an electrode containing the above compounds (1) and (2) is used, an insulating film derived from the compounds (1), (2) and the electrolytic solution is formed on the electrode surface even under a high voltage load. It is expected that the battery will have an overcharge prevention function. In addition, the stability of the compounds (1) and (2) is increased by having a cyano group, and it is difficult for the compounds (1) and (2) to react with other components. It is thought that it contributes to improvement.

  In addition, the compounds (1) and (2) according to the present invention, in which the central element is boron and a cyano group that is a strong electron-withdrawing group is introduced, include moisture and It is also considered to have an effect of collecting lithium fluoride and hydrofluoric acid generated during charging and discharging. If the electrolytic solution contains a large amount of moisture, the supporting salt is easily decomposed, which causes a problem not only in terms of function but also in terms of safety. Moreover, the precipitation of lithium fluoride causes battery ignition and causes deterioration of the performance of the electrode surface coating. Hydrofluoric acid is toxic and is known to cause elution of the metal used for the positive electrode into the electrolyte. Therefore, it is important to collect these components present in the battery, and the battery electrode contains the compounds (1) and (2) having the above effects, thereby ensuring the safety of the battery. It is believed that the battery characteristics can be improved.

  First, the compounds (1) and (2) contained in the battery electrode of the present invention will be described.

1. Cyanoborate Compound The compounds (1) and (2) according to the present invention each comprise a cation represented by M ^{n +} and a cyanoborate anion in which a cyano group is bonded to boron. First, a cation that is a structure common to the compounds (1) and (2) will be described.

1-1. Cation; M ^{n +}
In the general formulas (1) and (2), M ^{n +} represents H ⁺ , an organic cation or an inorganic cation.

As the organic cation M ^{n +} constituting the compound according to the present invention, the general formula (3): L ⁺ -R _S
(In the formula, L represents C, Si, N, P, S or O, R is the same or different organic group, and may be bonded to each other. S represents the number of R bonded to L. And s is a value determined by the valence of the element L and the number of double bonds directly bonded to L).

  The “organic group” represented by R means a group having at least one hydrogen atom, fluorine atom, or carbon atom. The “group having at least one carbon atom” only needs to have at least one carbon atom, and may have another atom such as a halogen atom or a hetero atom, or a substituent. Good. Examples of the substituent include amino group, imino group, amide group, ether bond group, thioether bond group, ester group, hydroxyl group, alkoxy group, carboxyl group, carbamoyl group, cyano group, disulfide group, nitro group. Group, nitroso group, sulfonyl group and the like.

  Examples of the onium cation represented by the general formula (3) include those represented by the following general formula.

(R in the formula is the same as in the general formula (3))

  Among the six onium cations represented by the above general formula, those in which L is N, P, S or O are more preferable, and onium cations in which L is N are more preferable. The said onium cation may be used independently and may use 2 or more types together. Specifically, examples of the onium cation in which L is N, P, S, or O include those represented by the following general formulas (4) to (6).

  General formula (4):

At least one of 15 types of heterocyclic onium cations represented by the formula:

Examples of the organic groups R ^{1 to} R ⁸ include the same organic groups R exemplified in the general formula (3). More specifically, R ^{1 to} R ⁸ are a hydrogen atom, a fluorine atom, or an organic group. Examples of the organic group include a straight chain, a branched chain, or a ring (provided that R ^{1 to} R ⁸ are bonded to each other to form a ring). Are preferably a hydrocarbon group having 1 to 18 carbon atoms or a fluorine group, and more preferably a hydrocarbon group having 1 to 8 carbon atoms or a fluorine group. Moreover, the organic group may contain the substituent illustrated about the said General formula (3), hetero atoms, such as N, O, and S, and a halogen atom.

  General formula (5):

(In the formula, R ^{1 to} R ¹² are the same as R ^{1 to} R ^{8 in} formula (4)).
At least one of nine types of saturated ring onium cations represented by the formula:

  General formula (6):

(Wherein R ^{1 to} R ⁴ are the same as R ^{1 to} R ^{8 in} the general formula (4))
A chain onium cation represented by

For example, the chain onium cation represented by the general formula (6) includes tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, tetraheptylammonium, tetrahexylammonium, tetraoctylammonium, triethylmethylammonium, methoxy Ethyl diethylmethylammonium, trimethylphenylammonium, benzyltrimethylammonium, benzyltriethylammonium, benzyltributylammonium, dimethyldistearylammonium, diallyldimethylammonium, 2-methoxyethoxymethyltrimethylammonium and tetrakis (pentafluoroethyl) ammonium, N-methoxytrimethyl Ammonium, N-ethoxylate Quaternary ammoniums such as methylammonium and N-propoxytrimethylammonium, tertiary ammoniums such as trimethylammonium, triethylammonium, tributylammonium, diethylmethylammonium, dimethylethylammonium and dibutylmethylammonium, dimethylammonium and diethylammonium, Secondary ammoniums such as dibutylammonium, primary ammoniums such as methylammonium, ethylammonium, butylammonium, hexylammonium and octylammonium, and ammonium compounds represented by NH ₄ are included.

  Among the onium cations of the above general formulas (4) to (6), an onium cation containing a nitrogen atom is more preferable, and a more preferable one is the following general formula:

(In the formula, R ^{1 to} R ¹² are the same as R ^{1 to} R ^{8 in} the general formula (4).)
And at least one of six kinds of onium cations represented by the formula:

  Among the six kinds of onium cations, chain quaternary ammonium such as tetraethylammonium, tetrabutylammonium and triethylmethylammonium, chained tertiary ammonium such as triethylammonium, tributylammonium, dibutylmethylammonium and dimethylethylammonium, Pyrrolidiniums such as 1-ethyl-3-methylimidazolium and imidazolium such as 1,2,3-trimethylimidazolium, N, N-dimethylpyrrolidinium and N-ethyl-N-methylpyrrolidinium are readily available. It is more preferable because it exists. More preferred are quaternary ammonium and imidazolium. From the viewpoint of reduction resistance, quaternary ammonium such as tetraethylammonium, tetrabutylammonium and triethylmethylammonium classified into the chain onium cation is more preferable.

The inorganic cations ^{M n +, Li +, Na} +, K +, Cs +, 1 monovalent inorganic cations M ¹⁺ of Pb ^{+ like; Mg 2+, Ca 2+, Zn} 2+, Pd 2+, Sn 2 ^{+, Hg 2+, Rh 2+,} Cu 2+, Be 2+, Sr 2+, 2 divalent inorganic cations M ²⁺ of Ba ^2+, and the like; and trivalent inorganic cation M ³ of Ga ³⁺ etc. ⁺ . Among these, Li ⁺ , Na ⁺ , Mg ²⁺ and Ca ²⁺ are preferable because they have a small ionic radius and can be easily used for batteries and the like, and a more preferable inorganic cation M ^{n +} is Li ⁺ .

1-2. Compound (1)
The compound (1) according to the present invention is a compound represented by the general formula (1); M ^{n +} ([B (CN) _4−m Y _m ] ⁻ ) _n , H ⁺ represented by M ^{n +} , A general formula in which an organic cation or an inorganic cation and boron are bonded to a cyano group: —CN and —Y: [B (CN) _4−m Y _m ] ⁻ ([B (CN) _{4− m} Y _m ] ⁻ ) and a cyanoborate anion.

In general formula (1), Y represents halogen, a hydrocarbon group having 1 to 10 carbon atoms in the main chain which may have halogen, —C (O) R ¹⁴ , —S (O) ₁ R ^14. , -Z (R ¹⁴ ) ₂ , -SR ¹⁴ or -OR ¹⁵ , R ¹⁴ represents H, halogen, or an organic substituent having 1 to 10 atoms in the main chain, and Z represents N or P. R ¹⁵ is H, halogen, an alkylsilyl group having 1 to 10 carbon atoms, an alkanoyl group having 1 to 10 carbon atoms, a halosulfinyl group, or an alkylsulfinyl group having 1 to 10 carbon atoms which may have a halogen. , A halosulfonyl group, or an alkylsulfonyl group having 1 to 10 carbon atoms which may have a halogen, l represents an integer of 1 to 2, m represents an integer of 1 to 3, and n represents 1 Represents an integer of ~ 3.

In the above general formula (1), since m is an integer of 1 to 3, the cyanoborate anion according to the compound (1) includes a tricyanoborate anion (m = 1): [B (CN) ₃ Y] ⁻ Dicyanoborate anion (m = 2): [B (CN) ₂ Y ₂ ] ⁻ ; monocyanoborate anion (m = 3): [B (CN) Y ₃ ] ⁻ ;

  When m is 2 or 3, two or more Ys may be the same or different, and two or more Ys may be bonded to each other to form a cyclic structure containing a B atom. Examples of the cyanoborate anion having a cyclic structure include anions related to the compound (2) described later. When the substituent Y constituting the cyanoborate anion is halogen, Y includes F, Cl, Br, or I. When Y is halogen, m is preferably 2 or more. At this time, it is preferable that two or more Ys are different halogens or a substituent other than halogen and halogen.

  When the substituent Y is a hydrocarbon group having 1 to 10 carbon atoms in the main chain, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, sec- C 1-10 alkyl groups such as butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl; vinyl, propenyl, isopropenyl, allyl, 1- Carbon such as butenyl group, 2-butenyl group, 3-butenyl group, 1,3-butadienyl group, 1-cyclohexenyl group, 2-cyclohexenyl group, 3-cyclohexenyl group, methylcyclohexenyl group, ethylcyclohexenyl group An alkenyl group having 1 to 10 carbon atoms; an alkynyl having 1 to 10 carbon atoms such as an ethynyl group, a propargyl group, a cyclohexylethynyl group, and a phenylethynyl group; ; Include; phenyl group, a benzyl group, a thienyl group, a pyridyl group, an aryl group or a hetero atom-containing aryl group having 6 to 10 carbon atoms such as an imidazolyl group.

  Examples of the halogenated hydrocarbon group having 1 to 10 carbon atoms in the main chain include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, a difluorochloromethyl group, and a fluorodichloromethyl group. , Fluoroethyl group, difluoroethyl group, trifluoroethyl group, tetrafluoroethyl group, perfluoroethyl group, fluorochloroethyl group, chloroethyl group, fluoropropyl group, perfluoropropyl group, fluorochloropropyl group, perfluorobutyl group Perfluorooctyl group, pentafluorocyclohexyl group, perfluorocyclohexyl group, pentafluorophenyl group, perchlorophenyl group, fluoromethylene group, fluoroethylene group, fluorocyclohexene group, etc. Some or all of the hydrogen atoms halogen (F, Cl, Br or I) a halogenated alkyl group or halogenated aryl groups substituted with the like.

The hydrocarbon group Y having 1 to 10 carbon atoms in the main chain which may have a halogen has a substituent (for example, an alkoxy group, an amino group, a cyano group, a carbonyl group, a sulfonyl group, etc.). May be. Y (except when it is halogen) may have a functional group containing a hetero atom such as Si, B, O, N, and Al. Examples of the functional group include a trimethylsilyl group, a triethylsilyl group, a dimethoxyaluminum group, —CH ₂ CH ₂ B (CN) ₃ , —C ₃ H ₆ B (CN) _{3 and the} like.

In the above -C (O) R ¹⁴ , -S (O) ₁ R ¹⁴ , -Z (R ¹⁴ ) ₂ and -SR ¹⁴ , R ¹⁴ is H, halogen, or the number of atoms of the main chain is 1-10. Represents an organic substituent. As the halogen, fluorine, chlorine, bromine, iodine or the like is preferable. The organic substituent may be linear, branched or cyclic, and may have two or more of these structures, or may have a substituent. Furthermore, the organic substituent R ¹⁴ may contain an unsaturated bond. The number of atoms in the main chain of the organic substituent R ¹⁴ is as described above, but the number of carbons (including the substituent) contained in the organic substituent R ¹⁴ is preferably in the range of 1 to 20, more preferably. Is in the range of 1-10. The valence of the organic substituent R ¹⁴ , that is, the number of bonding ends may be one or two or more. The organic substituent R ¹⁴ may contain hetero atoms other than carbon and hydrogen (O, N, Si, etc.) and halogen atoms (F, Cl, Br, etc.), and the number and position thereof are particularly limited. There is no. Therefore, for example, for Y in the general formula (1), when Y is —SR ¹⁴ , the type of atoms adjacent to S is not particularly limited to carbon, and may be, for example, a heteroatom such as Si or Al. There may be. Further, the organic substituent R ¹⁴ may be composed only of atoms other than carbon.

Specific examples of the organic substituent R ¹⁴ include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, pentyl group, Saturated hydrocarbon groups including linear, branched, cyclic, or combinations thereof, such as hexyl, heptyl, octyl, 2-ethylhexyl, cyclohexyl, methylcyclohexyl, cyclohexylmethyl, and adamantyl; vinyl Group, propenyl group, isopropenyl group, allyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1,3-butadienyl group, 1-cyclohexenyl group, 2-cyclohexenyl group, 3-cyclohexenyl group Group, methylcyclohexenyl group, ethylcyclohexenyl group, cyclohexenylmethyl group, phenyl group, tolyl (Methylphenyl group), benzyl group, phenylethyl group, methylphenylethyl group, cyclohexylphenyl group, vinylphenyl group, dimethylphenyl group, naphthyl group, methylnaphthyl group, methylene group (methylidene group), ethylene group (ethylidene group) A monovalent or divalent or higher valent group such as a propylene group (propylidene group), a cyclohexene (1,2-, 1,3-, 1,4-) group, a phenylene (o-, m-, p-) group, Unsaturated hydrocarbon group including linear, branched, cyclic or combinations thereof; fluoromethyl group, difluoromethyl group, trifluoromethyl group, chloromethyl group, bromomethyl group, iodomethyl group, difluorochloromethyl group, fluorodichloro Methyl group, fluoroethyl group, difluoroethyl group, trifluoroethyl group, tetrafluoro Til group, perfluoroethyl group, fluorochloroethyl group, chloroethyl group, fluoropropyl group, perfluoropropyl group, fluorochloropropyl group, perfluorobutyl group, perfluorooctyl group, pentafluorocyclohexyl group, perfluorocyclohexyl group, Halogen including monovalent or divalent or more, linear, branched, cyclic, or combinations thereof, such as pentafluorophenyl group, perchlorophenyl group, fluoromethylene group, fluoroethylene group, fluorocyclohexene group, fluorophenylene group, etc. Hydrocarbon group; cyanomethyl group, dicyanomethyl group, tricyanomethyl group, cyanoethyl group, dicyanoethyl group, tricyanoethyl group, tetracyanoethyl group, cyanopropyl group, cyanobutyl group, cyanooctyl group, cyano group Monovalent or divalent or higher, linear, branched, cyclic, or combinations thereof, such as cyclohexyl group, cyanophenyl group, cyanomethylene group, cyanoethylene group, dicyanoethylene group, cyanocyclohexene group, cyanophenylene group, etc. Containing cyanated hydrocarbon group: methoxymethyl group, methoxyethyl group, methoxypropyl group, methoxybutyl group, methoxycyclohexyl group, methoxyvinyl group, methoxyphenyl group, methoxynaphthyl group, ethoxymethyl group, propoxymethyl group, butoxymethyl group Pentyloxymethyl group, hexyloxymethyl group, cyclohexyloxymethyl group, phenyloxymethyl group, vinyloxymethyl group, isopropenyloxymethyl group, tert-butyloxymethyl group, naphthyloxymethyl group, methoxyethoxymethyl Group, ethoxyethoxymethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group, pentyloxyethyl group, hexyloxyethyl group, cyclohexyloxyethyl group, phenyloxyethyl group, vinyloxyethyl group, isopropenyloxyethyl group , Tert-butyloxyethyl group, naphthyloxyethyl group, methoxyethoxyethyl group, ethoxyethoxyethyl group, methyleneoxymethyl group, ethyleneoxyethyl group, phenyleneoxyphenyl group, etc. , Branched, cyclic, or alkoxylated and / or aryloxylated hydrocarbon groups; acetyl, propanoyl, butanoyl, pentanoyl, hexanoyl, heptanoyl, octanoyl, isobutanoyl , Acryloyl group, methacryloyl group, methyl oxalyl group, methyl malonyl group, methyl succinyl group, oxalyl group, malonyl group, succinyl group, etc., monovalent or divalent or more, linear, branched, cyclic or combinations thereof An alkanoyl group containing or an organic substituent containing an alkanoyl group; acetyloxymethyl group, acetyloxyethyl group, benzoyloxyethyl group, butyrolactyl group, caprolactyl group, methoxycarbonyl group, ethoxycarbonyl group, methoxyethyleneoxycarbonyl group, etc. An organic substituent having an ester bond containing a monovalent or divalent linear, branched, cyclic or combination thereof; amino group, dimethylamino group, ethylmethylamino group, methylphenylamino group, diphenylamino group , Acetylamino group, tert -Monovalent or divalent or higher valent such as butoxycarbonylamino group, benzyloxycarbonylamino group, 9-fluorenylmethyloxycarbonylamino group, dimethylaminoethyl group, pyrrolidinylethyl group, pyrrolidonylethyl group, Nitrogen-containing organic substituents including linear, branched, cyclic or combinations thereof; alkyl or arylthio groups such as methylthio group, ethylthio group, and tolylthio group; halothio groups such as fluorothio group and chlorothio group; trifluoromethylthio group; A group having a thioalkoxy structure such as a halogenated alkyl or arylthio group such as a pentafluoroethylthio group or a pentafluorophenylthio group; an alkylsulfinyl group such as a methylsulfinyl group; an arylsulfinyl group such as a tolylsulfinyl group; a fluorosulfinyl group; Organic substituents having a sulfinyl group such as a halogenated alkyl such as a halosulfinyl group such as a rosulfinyl group, a trifluoromethylsulfinyl group, a pentafluorophenylsulfinyl group or an arylsulfinyl group; a methylsulfonyl group, a tolylsulfonyl group, a fluorosulfonyl group Organic substituents having a sulfonyl group such as trifluoromethylsulfonyl group, pentafluorophenylsulfonyl group; organic substituents having a hetero atom such as trimethylsilyl group, triethylsilyl group, dimethoxyaluminum; —CH ₂ CH ₂ OB (CN ) ₃ , —C ₃ H ₆ OB (CN) ₃ ; In addition, the organic substituent R ¹⁴ may have a structure in which two or more organic substituents selected from the above-described organic substituents are connected.

Among the organic substituents R ¹⁴ , halogen such as fluorine and chlorine, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl Group, pentyl group, hexyl group, heptyl group, octyl group and 2-ethylhexyl group, hydrocarbon group having 1 to 10 carbon atoms such as ethylene group, propylene group; fluoromethyl group, difluoromethyl group, trifluoromethyl group, Chloromethyl group, bromomethyl group, iodomethyl group, difluorochloromethyl group, fluorodichloromethyl group, fluoroethyl group, difluoroethyl group, trifluoroethyl group, tetrafluoroethyl group, perfluoroethyl group, fluorochloroethyl group, chloroethyl group , Fluoropropyl group, perfluoropropyl group, fluoro Halogenated hydrocarbon groups having 1 to 10 carbon atoms, such as chloropropyl group, perfluorobutyl group, perfluorooctyl group, pentafluorocyclohexyl group, perfluorocyclohexyl group, fluoromethylene group, fluoroethylene group and fluorocyclohexene group; Phenyl group, tolyl group, benzyl group, phenylethyl group, methylphenylethyl group, cyclohexylphenyl group, vinylphenyl group, naphthyl group, methylnaphthyl group, phenylene (o-, m-, p-) group, pentafluorophenyl group Aryl group having 6 to 10 carbon atoms such as perchlorophenyl group or halogenated aryl group; cyanated hydrocarbon group such as cyanomethyl group, dicyanomethyl group, tricyanomethyl group, cyanoethyl group; acetyl group, propanoyl group, butanoyl group , Penta An yl group, a hexanoyl group, a heptanoyl group, an octanoyl group, an isobutanoyl group, an acryloyl group, a methacryloyl group, a methyloxalyl group, a methylmalonyl group, a methylsuccinyl group, an oxalyl group, a malonyl group, a succinyl group, etc. An alkanoyl group; an organic substituent having an ester bond having 1 to 10 carbon atoms such as a methoxycarbonyl group, an ethoxycarbonyl group, or a methoxyethyleneoxycarbonyl group, or a carbon number of 1 to 10 such as a trimethylsilyl group or a triethylsilyl group An alkylsilyl group;

More preferable organic substituent R ¹⁴ is fluorine, methyl group, ethyl group, propyl group, isopropyl group, butyl group, phenyl group, ethylene group, propylene group, trifluoromethyl group, perfluoroethyl group, cyanoethyl group, acetyl group. Group, propanoyl group, oxalyl group, methoxyethyleneoxycarbonyl group, and trimethylsilyl group.

Therefore, when the Y is represented by -C (O) R ¹⁴ is, R ¹⁴ is halogen, a hydrocarbon group or a halogenated hydrocarbon group of saturated or unsaturated, alkoxylation or aryloxy hydrocarbon group, Alternatively, those which are nitrogen-containing organic substituents are preferred, and those wherein R ¹⁴ is a methyl group, ethyl group, phenyl group, trifluoromethyl group or pentafluorophenyl group are more preferred. Therefore, as the substituent Y, acetyl group, propanoyl group, butanoyl group, pentanoyl group, hexanoyl group, heptanoyl group, octanoyl group, isobutanoyl group, trifluoroacetyl group, benzoyl group, pentafluorobenzoyl group, acryloyl group, methacryloyl group Including linear, branched, cyclic, or combinations thereof, such as methyl oxalyl group (—COCOCH ₃ ), methyl malonyl group (—COCH ₂ COCH ₃ ), methyl succinyl group (—COCH ₂ CH ₂ COCH ₃ ) Organic substituents containing alkanoyl group or alkanoyl structure, acetoxymethylcarbonyl group, acetoxyethylcarbonyl group, benzoyloxyethylcarbonyl group, methoxycarbonyl group, ethoxycarbonyl group, methoxyethyleneoxycarbonyl group, etc. Organic substituents having an ester bond including linear, branched, cyclic or combinations thereof; linear, branched, cyclic or the like such as amide group, N-alkylamide group, N-phenylamide group, etc. Nitrogen-containing organic substituents including combinations.

As the group represented by —S (O) ₁ R ¹⁴ , R ¹⁴ is preferably a halogen, a saturated or unsaturated hydrocarbon group or a halogenated hydrocarbon group. Sulfinyl group, chlorosulfinyl group, trifluoromethylsulfinyl group, pentafluoroethylsulfinyl group, phenylsulfinyl group, pentafluorophenylsulfinyl group, sulfinyl group such as tolylsulfinyl group (l = 1), fluorosulfonyl group, chlorosulfonyl group, A sulfonyl group (l = 2) such as a trifluoromethylsulfonyl group, a pentafluoroethylsulfonyl group, a tolylsulfonyl group, a phenylsulfonyl group, or a pentafluorophenylsulfonyl group is more preferable.

-C (O) R ¹⁴ and -S (O) ₁ R ¹⁴ are electron-withdrawing substituents like the cyano group and delocalize the negative charge charged in the central element. As a result, since the cyanoborate anion is stabilized, it is possible to form a salt that is difficult to decompose even when the cyanoborate compound according to the present invention is exposed to a high voltage or a high temperature.

Examples of the group represented by —Z (R ¹⁴ ) ₂ include amino groups in which Z is N such as dimethylamino group and ethylmethylamino group; phosphinos in which Z is P such as diphenylphosphino group and dicyclohexylphosphino group. Group;

The group in which Y is represented by —SR ¹⁴ is a group in which R ¹⁴ is a hydrocarbon group having 1 to 20 carbon atoms which may have a halogen (eg, methylthio group, trifluoromethylthio group, etc.); Etc. Further, when two or more —SR ¹⁴ are bonded to B, two or more R ¹⁴ may be bonded to form a ring.

Among the -OR ^15, R ¹⁵ are the same as in the above R ^14. R ¹⁵ is preferably H, halogen, an alkylsilyl group having 1 to 10 carbon atoms, an alkanoyl group having 1 to 10 carbon atoms, a halosulfinyl group, or an alkylsulfinyl group having 1 to 10 carbon atoms which may have a halogen. , A halosulfonyl group, or an alkylsulfonyl group having 1 to 10 carbon atoms which may have a halogen.

As the group in which Y is represented by —OR ¹⁵ , specifically, a group in which R ¹⁵ is an alkylsilyl group such as a trimethylsilyl group or a triethylsilyl group; an acetyl group, a propanoyl group, a butanoyl group, a pentanoyl group, Hexanoyl group, heptanoyl group, octanoyl group, isopropanoyl group, isobutanoyl group, acryloyl group, methacryloyl group, methyloxalyl group, methylmalonyl group, methylsuccinyl group, oxalyl group, malonyl group, succinyl group, etc., R ¹⁵ is monovalent Or a divalent or higher alkanoyl group or a group having an alkanoyl structure selected from linear, branched, cyclic or combinations thereof; a fluorosulfinyl group, a chlorosulfinyl group, a trifluoromethylsulfinyl group, a tolylsulfinyl group, etc. group R ¹⁵ has a sulfinyl group, Is fluoro sulfonyl group, chlorosulfonyl group, trifluoromethylsulfonyl group, tolyl sulfonyl group, R ¹⁵ is a group having a sulfonyl group; and the like. When two or more OR ¹⁵ are bonded to B, two or more R ¹⁵ may be bonded to form a ring.

When -Z (R ¹⁴ ) ₂ , -SR ^14, or -OR ¹⁵ is introduced into the cyanoborate salt, it becomes a salt excellent in solubility in a solvent as well as high withstand voltage. In this case, it is preferable that R ¹⁴ or R ¹⁵ contains an electron-withdrawing substituent because the stability of the cyanoborate anion is increased. Specifically, R ¹⁴ and R ¹⁵ preferably contain an alkanoyl group, a sulfinyl group, or a sulfonyl group, and the cyanoborate salt more preferably has a structure such as compound (2) described later. Similarly, R ¹⁴ and R ¹⁵ are preferably fluorine or a group containing fluorine such as a fluoroalkyl group.

Examples of the cyanoborate anion related to the compound (1) include thioalkoxytricyanoborate anions such as [B (CN) ₃ (SMe)] ⁻ ; [B (CN) ₃ (CF ₃ )] ⁻ , [B ( Halogenated or halogenated alkyl cyanoborate anions such as (CN) ₃ (C ₂ F ₅ )] ^- ; [B (CN) ₃ (Ph)] ^- , [B (CN) ₃ (Me)] ^- , [B Alkylated or arylated cyanoborate anions such as (CN) ₃ (CH ₂ ) ₆ B (CN) ₃ ] ²⁻ , etc .; [B (CN) ₃ (OCOCH ₃ )] ⁻ , [B (CN) ₃ ( OCOCF ₃ )] ⁻ , [B (CN) ₃ (OCOC ₂ H ₅ )] ⁻ , [B (CN) ₃ (OCOOCH ₃ )] ⁻ , [B (CN) ₃ (OCOOC ₂ H ₅ )] ⁻ , etc. ester cyano anions _{such; [B (CN) 3 (} OSO 2 F) _{^{-, [B (CN) 3}} (OSO 2 CF 3)] -, [B (CN) 3 (OSO 2 CH 3)] -, [B (CN) 3 (OSO 2 C 6 H 4 CH 3)] - [B (CN) ₃ (SO ₂ F)] ⁻ , [B (CN) ₃ (SO ₂ CF ₃ )] ⁻ , [B (CN) ₃ (SO ₂ CH ₃ )] −, [B (CN) Cyanoborate anions having a sulfonyl group such as ₃ (SO ₂ C ₆ H ₄ CH ₃ )] ^- ; [B (CN) ₃ (COCH ₃ )] ^- , [B (CN) ₃ (COCF ₃ )] ^{-and the} like And acylsilanated cyanoborate anions such as [B (CN) ₃ (OSiCH ₃ )] ⁻ , and the like.

  The compound (1) according to the present invention includes all compounds composed of combinations of the above cations and anions. Specific compounds (1) include triethylmethylammonium tricyanophenylborate, triethylmethylammonium tricyano (trifluoromethyl) borate, triethylmethylammonium tricyano (cyanoethoxy) borate, 1-ethyl-3-methylimidazolium. Salts of organic cations such as tricyanophenylborate; lithium tricyanomethylthioborate, lithium tricyano (trifluoromethyl) borate, lithium tricyanophenylborate, lithium tricyanomethylborate, lithium tricyanoacetoxyborate, lithium tricyano (tri Fluoroacetoxy) borate, lithium tricyano ((methoxycarbonyl) oxo) borate, lithium tricyano (fluorosulfonate) borate Lithium tricyano (trifluoromethanesulfonate) borate, lithium tricyano (methanesulfonate) borate, lithium tricyano (p-toluenesulfonate) borate, lithium tricyano (fluorosulfonyl) borate, lithium tricyanoacetyl borate, lithium tricia And salts of inorganic cations such as lithium (trifluoroacetyl) borate and lithium tricyano (trimethylsiloxy) borate.

1-3. Compound (2)
The compound (2) according to the present invention is a compound represented by the following general formula (2). As shown in the following general formula (2), the cyanoborate anion constituting the compound (2) has a cyclic structure containing a boron atom. That is, in the general formula (1) representing the above compound (1), the compound (2) is a compound in which m is 2 or 3, and two Ys are bonded to each other to form a cyclic structure containing a boron atom. It corresponds to.

In general formula (2), M ^{n +} represents H ⁺ , a monovalent, divalent, or trivalent organic or inorganic cation, and Y ′ represents the carbon number of the main chain which may have H, halogen, or halogen. Represents a hydrocarbon group of 1 to 10, a cyano group, —C (O) R ¹⁴ , —S (O) ₁ R ¹⁴ , —Z (R ¹⁴ ) ₂ or —XR ¹⁴ , wherein R ¹⁴ represents H, halogen Or an organic substituent having 1 to 10 atoms in the main chain, Z represents N or P, X represents O or S, l represents an integer of 1 to 2, and n represents 1 to 3. An integer is represented, and p represents an integer of 0 to 10. Y ′ in the general formula (2) is a substituent selected from the group consisting of halogen, a hydrocarbon group having 1 to 10 carbon atoms in the main chain which may have halogen, and a cyano group. preferable.

  In the cyanoborate anion represented by the general formula (2), p represents the carbon number of a direct bond or a methylene group in which two ester bonds bonded to boron are bonded to each other. p is preferably 0-4, more preferably 0-2.

In the general formula (2), since p is an integer of 0 to 10, the cyanoborate anion according to the compound (2) includes cyanooxalatoborate (p = 0) and cyanomalonatoborate (p = 1). , Cyanosuccinate borate (p = 2), cyanoglutaratoborate (
p = 3), cyano adipolato borate (p = 4) and the like.

Among the substituents Y ′ constituting the cyanoborate anion, halogen, a hydrocarbon group having 1 to 10 carbon atoms in the main chain which may have halogen, a cyano group, —C (O) R ¹⁴ , — S (O) ₁ R ¹⁴ , —Z (R ¹⁴ ) ₂ and R ¹⁴ are the same as in the compound (1).

Examples of the substituent in which Y ′ is represented by —XR ¹⁴ include a hydrocarbon group having 1 to 20 carbon atoms in which X is O and R ¹⁴ may have a halogen (for example, methyl group, ethyl group, Group, a phenyl group, a pentafluorophenyl group, a trifluoromethyl group, a saturated hydrocarbon group such as a pentafluoroethyl group or an unsaturated hydrocarbon group); X is O, and R ¹⁴ is an alkylsilyl group ( An alkanoyl group or an alkanoyl structure selected from linear, branched, cyclic, or combinations thereof, wherein X is O and R ¹⁴ is monovalent, for example, a trimethylsilyl group, triethylsilyl group, etc. A group (for example, acetyl group, trifluoroacetyl group, propanoyl group, butanoyl group, pentanoyl group, hexanoyl group, heptanoyl group, octanoyl group, isopropanoyl group) Isobutanoyl group, a benzoyl group, pentafluorobenzoyl group, an acryloyl group, a methacryloyl group, methyl oxalyl group, methylmalonyl group, group a Mechirusukushiniru group); a is X O, R ¹⁴ is a sulfinyl group (e.g., fluoro A group having a sulfinyl group, a chlorosulfinyl group, a trifluoromethylsulfinyl group, a tolylsulfinyl group, etc.) or a sulfonyl group (a fluorosulfonyl group, a chlorosulfonyl group, a trifluoromethylsulfonyl group, a tolylsulfonyl group, etc.); And a group in which R ¹⁴ is a hydrocarbon group having 1 to 20 carbon atoms which may have a halogen (for example, a methylthio group, a trifluoromethylthio group, etc.); and the like. X is O or S, but X is preferably O from the viewpoint of easy availability of raw materials and cost.

  More specific anions related to the compound (2) include those represented by the following formulas (2-1) to (2-14) (p is preferably an integer of 0 to 2, Or 1 is more preferable, and 0 is more preferable. Preferred anions include (2-1), (2-2), (2-3), (2-4), (2-7), (2-9) and (2-10).

  The compound (2) according to the present invention includes all compounds composed of combinations of the above cations and anions. Specific compounds (2) include triethylmethylammonium cyanofluorooxalatoborate, triethylammonium dicyanooxalatoborate, tributylammonium dicyanooxalatoborate, triethylammonium dicyanomalonatoborate, 1-ethyl-3-methylimidazolium dicyano. Oxalatoborate, triethylmethylammonium dicyanosuccinateborate, triethylmethylammonium dicyanooxalateborate (triethylmethylammonium dicyanooxalylborate), triethylmethylammoniummethylcyanooxalateborate, triethylmethylammonium trifluoromethylcyanooxalateborate, 1- Ethyl-3-methylimidazolium cyanophenylmalonatobo Salts of organic cations such as lithium salt; lithium cyanophenyl oxalate borate, sodium dicyano oxalate borate, magnesium bis (dicyano oxalate borate), lithium trifluoromethyl cyanosuccinate borate, lithium cyanophenyl oxalate ethoxyborate, lithium cyano Pentafluorophenoxyoxalatobutoxyborate, lithium trifluoromethoxycyanomalonatoborate, lithium cyano (pentafluorophenoxy) succinateborate, lithium cyano (acetoxy) oxalatoborate, lithium cyano (trifluoroacetoxy) malonatoborate, lithium cyano (( Methoxycarbonyl) oxo) oxalatoborate, lithium cyano (fluorosulfonate) oxalatoborate Lithium cyano (trifluoromethanesulfonate) oxalatoborate, lithium cyano (methanesulfonate) oxalatoborate, lithium cyano (p-toluenesulfonate) oxalatoborate, lithium cyano (fluorosulfonyl) oxalatoborate, lithium cyano (acetyl) ) Oxalatoborate, lithium cyano (trifluoroacetyl) oxalatoborate, lithium cyano (trimethylsiloxy) oxalatoborate, lithium dicyanooxalatoborate (lithium dicyanooxalylborate), lithium cyanofluorooxalatoborate (lithium cyanofluorooxalylborate) ) And the like.

2. Battery Electrode The battery electrode of the present invention contains a cyanoborate compound represented by the general formula (1) or (2). When the electrode contains a cyanoborate compound, it is preferable because the concentration of the cyanoborate compound in the vicinity of the electrode can be easily improved and a film can be rapidly formed on the electrode surface. Further, since the cyanoborate compound is gradually released from the electrode, the discharge capacity and cycle characteristics are more unlikely to deteriorate over time. The electrode containing the cyanoborate compound is preferably a positive electrode. In addition, although the electrode of this invention should just contain the said compound (1) or (2), it may contain both a compound (1) and (2).

  In the electrode of the present invention, 0.01 mass part to 10 mass parts of the cyanoborate compound represented by the compound (1) or (2) with respect to 100 mass parts of the positive electrode mixture composed of an active material, a conductive additive, and a binder. It is preferable to contain a mass part, More preferably, it is 0.05 mass part-5 mass parts, More preferably, it is 0.1 mass part-3 mass parts. If the content of the cyanoborate compound is too small, it may be difficult to obtain the effect of inhibiting electrode corrosion and solvent decomposition, while it is difficult to obtain an effect proportional to the amount of use even if it is used in a large amount. There is a possibility that the ratio of the cyanoborate compound in the constituent material becomes large, making it difficult to manufacture the electrode. In addition, when the electrode of this invention contains compound (1) and (2), it is preferable that the total amount of compound (1) and (2) is the said range.

  The method for supporting (holding) the cyanoborate compound on the electrode is not particularly limited. For example, when a cyanoborate compound is used as a part of the electrode constituent material and the electrode is produced by a conventionally known production method, an electrode carrying the cyanoborate compound can be obtained. Specifically, a cyanoborate compound is mixed with an electrode material such as an electrode active material to be described later, a conductive additive, and a binder to prepare an electrode material composition, which is applied to a current collector and dried. Method: A method in which a sheet obtained by kneading, molding and drying an electrode material composition containing a cyanoborate compound is bonded to a current collector through a conductive adhesive, and pressed and dried; the electrode material composition is collected into a current collector A method of applying or spraying a solution containing a cyanoborate compound to a sheet-like electrode obtained by coating and drying, and drying; a liquid or slurry-like electrode material composition to which a liquid lubricant is added (cyanoborate compound) Are applied or cast on a positive electrode current collector to form a desired shape, and then the liquid lubricant is removed, and then the film is stretched in a uniaxial or multiaxial direction. Since the compounds (1) and (2) include those having hygroscopicity, the production of the electrode is preferably performed in an atmosphere having a dew point of −20 ° C. or lower.

3. Battery The battery of the present invention is not particularly limited as long as it uses an electrode containing a compound represented by the above general formula (1) or (2), but as a specific battery, For example, a lithium ion secondary battery, a lithium ion polymer secondary battery, a lithium primary battery, a multivalent cation secondary battery, and the like can be given. Also, the configuration of these batteries is not particularly limited, and conventionally known battery configurations such as an electrolytic solution, an electrode, and a separator can be employed in the present invention. In addition, it is preferable to manufacture any battery in an atmosphere with a dew point of −20 ° C. or lower. This is because the compounds (1) and (2) include those having hygroscopicity.

  An electrolyte solution having a configuration common to the batteries will be described.

3-1. Electrolytic Solution The electrolytic solution used for the battery usually includes an electrolyte and a medium. First, the electrolyte will be described.

3-1-1. Electrolyte In the present invention, a conventionally known electrolyte can be used. As the electrolyte, those having a large dissociation constant in the electrolytic solution and having an anion that is difficult to solvate with a non-aqueous solvent described later are preferable. Specific examples of the electrolyte include alkali metal salts and alkaline earth metal salts of trifluoromethanesulfonic acid such as LiCF ₃ SO ₃ , NaCF ₃ SO ₃ , KCF ₃ SO ₃ ; LiC (CF ₃ SO ₂ ) ₃ , LiN ( Perfluoroalkanesulfonic acid imide such as CF ₃ CF ₂ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ or alkali metal salt or alkaline earth metal salt of fluorosulfonyl imide; hexafluoro such as LiPF ₆ , NaPF ₆ , KPF ₆ Alkali metal salts and alkaline earth metal salts of phosphoric acid; alkali metal salts and alkaline earth metal salts of perchloric acid such as LiClO ₄ and NaClO ₄ ; tetrafluoroborate salts such as LiBF ₄ and NaBF ₄ ; lithium tetracyanoborate; Lithium tricyanomethoxyborate, sodium tricyanomethoxyborate, magnesium bis Anomethoxyborate), lithium tricyanoisopropoxyborate, lithium tricyanobutoxyborate, lithium tricyanophenoxyborate, lithium tricyano (pentafluorophenoxy) borate, lithium tricyano (trimethylsiloxy) borate, lithium tricyano (hexafluoroiso) propoxy) borate, lithium tricyanomethylphosphine thio borate, lithium dicyano-dimethoxy borate, lithium cyano trimethoxy borate, lithium dicyano-dimethoxy-borate, alkali metal salts of cyanoborohydride acids such as lithium cyano trimethoxy _{borate; LiAsF 6, LiI, LiSbF 6} , LiAlO 4 _{, LiAlCl 4, LiCl, NaI,} NaAsF 6, alkali metal salts of KI and the like; perchlorate tetraethylammonium en Quaternary ammonium salts of perchloric acid bromide, _{etc.; (C 2 H 5) 4} NBF 4, (C 2 H 5) 3 (CH 3) quaternary ammonium salts of tetrafluoroborate of ₄ such NBF; tetraethylammonium Tetracyanoborate, 1-ethyl-3-methylimidazolium tetracyanoborate, triethylmethylammonium tetracyanoborate, tetraethylammonium tetracyanoborate, tetraethylammonium tricyanomethoxyborate, triethylmethylammonium tricyanomethoxyborate, triethylmethylammonium tricyano Isopropoxyborate, triethylmethylammonium tricyanobutoxyborate, triethylmethylammonium tricyanophenoxyborate, triethylmethylammonium tricyano (Pentafluorophenoxy) borate, triethylmethylammonium tricyano (trimethylsiloxy) borate, triethylmethylammonium tricyanomethylthioborate, triethylmethylammonium tricyano (hexafluoroisopropoxy) borate, 1-ethyl-3-methylimidazolium tricyano Cyanoborates, triethylammonium tricyanomethoxyborate, tributylammonium tricyanomethoxyborate, ammonium salts of cyanoboric acid such as triethylmethylammonium dicyanodimethoxyborate, triethylmethylammonium cyanotrimethoxyborate; (C ₂ H ₅ ) ₄ NPF ₆ Quaternary ammonium salts; quaternary ammonium salts such as (CH ₃ ) ₄ P · BF ₄ and (C ₂ H ₅ ) ₄ P · BF ₄ Um salt; and the like. These electrolytes may be used individually by 1 type, and may be used in combination of 2 or more type.

Among the electrolytes, alkali metal salts and / or alkaline earth metal salts are preferable. Further, from the viewpoint of solubility in a non-aqueous solvent and ion conductivity, LiPF ₆ , LiBF ₄ , LiAsF ₆ , alkali metal salts or alkaline earth metal salts of perfluoroalkanesulfonic acid imide, chain quaternary quaternary Ammonium salts are preferred, and chain quaternary ammonium salts are preferred from the viewpoint of reduction resistance. As the alkali metal salt, a lithium salt, a sodium salt, and a potassium salt are preferable, and as the alkaline earth metal salt, a calcium salt and a magnesium salt are preferable. More preferred is a lithium salt.

  The electrolyte concentration is preferably used in the electrolytic solution according to the present invention so as to be 0.1 mol / L or more and a saturation concentration or less. More preferably, it is 0.2 mol / L to 2.5 mol / L, still more preferably 0.3 mol / L to 2 mol / L, still more preferably 0.6 mol / L to 1.8 mol / L, Still more preferably, it is 0.8 mol / L-1.4 mol / L. If the electrolytic mass is too small, it may be difficult to obtain a desired conductivity. On the other hand, if the electrolytic mass is too large, ion migration may be hindered.

3-1-2. Medium The medium is not particularly limited as long as it can dissolve the electrolyte, and any conventionally known medium used for batteries, such as a non-aqueous solvent, a polymer, and a polymer gel, can be used.

  As the non-aqueous solvent, a solvent having a large dielectric constant, high electrolyte solubility, a boiling point of 60 ° C. or higher, and a wide electrochemical stability range is preferable. More preferably, it is an organic solvent (non-aqueous solvent) having a low water content. Examples of such organic solvents include ethylene glycol dimethyl ether (1,2-dimethoxyethane), ethylene glycol diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2,6-dimethyltetrahydrofuran, tetrahydropyran, crown ether, triethylene glycol dimethyl ether, Ethers such as tetraethylene glycol dimethyl ether, 1,4-dioxane, 1,3-dioxolane; dimethyl carbonate, ethyl methyl carbonate (methyl ethyl carbonate), diethyl carbonate (diethyl carbonate), diphenyl carbonate, methyl phenyl carbonate, etc. Chain carbonates of ethylene carbonate (ethylene carbonate), propylene carbonate (propylene carbonate), 2,3-dimethylethylene carbonate, butyrate , Cyclic carbonates such as vinylene carbonate and 2-vinylethylene carbonate; aliphatic carboxylic acid esters such as methyl formate, methyl acetate, propionic acid, methyl propionate, ethyl acetate, propyl acetate, butyl acetate, amyl acetate; Aromatic carboxylic acid esters such as methyl acid and ethyl benzoate; Lactones such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone; trimethyl phosphate, ethyldimethyl phosphate, diethylmethyl phosphate, triethyl phosphate Phosphate esters such as acetonitrile, nitriles such as propionitrile, methoxypropionitrile, glutaronitrile, adiponitrile, 2-methylglutaronitrile, valeronitrile, butyronitrile, isobutylnitrile; N-methylformamide, N- Ethylforma Amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidinone, N-vinylpyrrolidone; dimethylsulfone, ethylmethylsulfone, diethylsulfone, sulfolane, 3-methylsulfolane, 2,4 -Sulfur compounds such as dimethylsulfolane: alcohols such as ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether; sulfoxides such as dimethyl sulfoxide, methyl ethyl sulfoxide, diethyl sulfoxide; Aromatic nitriles; nitromethane, 1,3-dimethyl-2-imidazolidinone, 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone, 3-methyl And ru-2-oxazolidinone.

  Among these, chain carbonic acid esters, cyclic carbonic acid esters, aliphatic carboxylic acid esters, lactones, ethers are preferable, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, γ-butyrolactone, γ-valerolactone and the like are more preferable. The said non-aqueous solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

  As a polymer used as a medium, an epoxy compound (polyethylene oxide (PEO), which is a homopolymer or copolymer of ethylene oxide, propylene oxide, butylene oxide, allyl glycidyl ether, etc.) or a polyether polymer such as polypropylene oxide), Methacrylic polymers such as polymethyl methacrylate (PMMA), nitrile polymers such as polyacrylonitrile (PAN), fluoropolymers such as polyvinylidene fluoride (PVdF), polyvinylidene fluoride-hexafluoropropylene, and copolymers thereof Etc. In addition, a polymer gel obtained by mixing these polymers with another organic solvent can also be used as the medium according to the present invention. Examples of the other organic solvent include the aprotic solvents described above.

  When the polymer gel is used as a medium, a solution in which an electrolyte is dissolved in the above-mentioned aprotic solvent is dropped onto a polymer formed by a conventionally known method, and the electrolyte and the aprotic solvent are impregnated and supported. Method: A method in which a polymer and an electrolyte are melted and mixed at a temperature equal to or higher than the melting point of the polymer and then formed into a film and impregnated with an aprotic solvent; an electrolytic solution in which an electrolyte is previously dissolved in an organic solvent and the polymer A method of forming a film by casting or coating after mixing and volatilizing an organic solvent (above, gel electrolyte); a method of melting and mixing a polymer and an electrolyte at a temperature equal to or higher than the melting point of the polymer and molding (Intrinsic polymer electrolyte);

3-1-3. Additive The electrolyte solution according to the present invention may contain an additive for the purpose of improving various characteristics of the battery.

  As additives, cyclic carbonates having unsaturated bonds such as vinylene carbonate (VC), vinyl ethylene carbonate (VEC), methyl vinylene carbonate (MVC), ethyl vinylene carbonate (EVC); fluoroethylene carbonate, trifluoropropylene carbonate, Carbonate compounds such as phenylethylene carbonate and erythritan carbonate; succinic anhydride, glutaric anhydride, maleic anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic anhydride, cyclopentanetetra Carboxylic anhydrides such as carboxylic dianhydride and phenyl succinic anhydride; ethylene sulfite, 1,3-propane sultone, 1,4-butane sultone, methane sulfone Sulfur-containing compounds such as methyl, busulfan, sulfolane, sulfolene, dimethyl sulfone, tetramethylthiuram monosulfide; 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3- Nitrogen-containing compounds such as dimethyl-2-imidazolidinone and N-methylsuccinimide; phosphates such as monofluorophosphate and difluorophosphate; saturated hydrocarbon compounds such as heptane, octane and cycloheptane; biphenyl and alkyl Biphenyl, terphenyl, partially hydrogenated terphenyl, unsaturated hydrocarbon compounds such as cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, and the like.

  The additive is preferably used in a concentration of 0.1% by mass to 10% by mass in the electrolytic solution of the present invention (more preferably 0.2% by mass to 8% by mass, and still more preferably 0.3% by mass). Mass% to 5 mass%). When the amount of the additive used is too small, it may be difficult to obtain an effect derived from the additive.On the other hand, even if another additive is used in a large amount, it is difficult to obtain an effect commensurate with the added amount. There is a possibility that the viscosity of the electrolytic solution increases and the conductivity decreases.

  In the battery of the present invention, the positive electrode potential when fully charged is preferably 4.0 V or more, more preferably 4.3 V or more, based on lithium. In addition, although the positive electrode potential at the time of a full charge is so preferable that it is high, it is preferable that it is 5.5 V or less from a safety viewpoint. More preferably, it is 5.0 V or less.

  The rated charging voltage of the battery of the present invention is not particularly limited, but is preferably 2.5 V or more, more preferably 3.5 V or more, still more preferably 4.0 V or more, and even more preferably 4. 3V or more. In addition, although an energy density can be raised, so that a rated charge voltage is high, when too high, it may be difficult to ensure safety. Therefore, it is preferable that the rated charging voltage is 5.5 V or less. More preferably, it is 5.0 V or less.

4). Lithium Ion Secondary Battery Among the above exemplified batteries, the lithium ion secondary battery will be described in more detail. A lithium ion battery has a positive electrode, a negative electrode, and an electrolytic solution. More specifically, a separator is provided between the positive electrode and the negative electrode, and the electrolytic solution is impregnated in the separator. In this state, it is housed in an outer case together with a positive electrode, a negative electrode, and the like.

  The lithium ion secondary battery of this invention has an electrode containing the said compound (1) or (2).

  The shape of the lithium ion secondary battery according to the present invention is not particularly limited, and any conventionally known shape can be used as the shape of the lithium ion secondary battery, such as a cylindrical shape, a square shape, a laminate shape, a coin shape, and a large size. Can do. Further, when used as a high voltage power source (several tens of volts to several hundreds of volts) for mounting on an electric vehicle, a hybrid electric vehicle, etc., a battery module configured by connecting individual batteries in series can be used. .

4-1. The positive electrode is a positive electrode active material composition containing a positive electrode active material, a conductive additive, a binder, a dispersion solvent and the like supported on a positive electrode current collector, and is usually formed into a sheet shape. .

  As a method for producing the positive electrode, for example, a method in which the positive electrode active material composition is applied to the positive electrode current collector by the doctor blade method or the like and dried after being immersed; the positive electrode active material composition is kneaded and dried. A method in which the obtained sheet is bonded to the positive electrode current collector via a conductive adhesive, pressed, and dried; a positive electrode active material composition to which a liquid lubricant is added is applied or cast on the positive electrode current collector; Examples include a method in which after forming into a desired shape, the liquid lubricant is removed, and then the film is stretched in a uniaxial or multiaxial direction. When it is desired to carry the compound (1) or (2) on the positive electrode, the compound (1) or (2) may be used as a material constituting the positive electrode active material composition. The positive electrode is preferably produced in an atmosphere having a dew point of −20 ° C. or lower.

4-1-1. Positive electrode current collector The material of the positive electrode current collector is not particularly limited, and for example, conductive metals such as aluminum, aluminum alloy, SUS (stainless steel), and titanium can be used. Among these, aluminum is preferable because it is easy to process into a thin film and is inexpensive.

4-1-2. Positive Electrode Active Material As the positive electrode active material, any known positive electrode active material used in lithium secondary batteries may be used as long as it can occlude and release lithium ions.

Specifically, lithium cobalt acid, lithium nickel acid, lithium manganese acid, LiNi was replaced partially Ni in LiMn ₂ O ₄ system _{0.5 Mn 1.5 O 4, LiNi 1} -xy Co x Mn y O 2 or LiNi _{1- xy Co x Al y O 2 (} 0 ≦ x ≦ 1,0 ≦ y ≦ 1) a transition metal oxide such as ternary oxide represented _{by, LiAPO 4 (a = Fe,} Mn, Ni, Co) and the like A compound having an olivine structure, a solid solution material incorporating a plurality of transition metals (an electrochemically inactive layered Li ₂ MnO ₃ and an electrochemically active layered LiM ″ O [M ″ = Co And a solid solution with a transition metal such as Ni] can be exemplified as the positive electrode active material. These positive electrode active materials may be used individually by 1 type, or may be used in combination of multiple.

4-1-3. Conductive aid Examples of the conductive aid include acetylene black, carbon black, graphite, metal powder material, single-walled carbon nanotube, multi-walled carbon nanotube, and vapor grown carbon fiber.

4-1-4. Binders As binders, fluorine resins such as polyvinylidene fluoride and polytetrafluoroethylene; synthetic rubbers such as styrene-butadiene rubber and nitrile butadiene rubber; polyamide resins such as polyamideimide; polyethylene, polypropylene and the like Polyolefin resin; poly (meth) acrylic resin; polyacrylic acid; cellulose resin such as carboxymethylcellulose; These binders may be used alone or in combination of two or more. These binders may be dissolved in a solvent at the time of use or dispersed in a solvent.

  The blending amounts of the conductive auxiliary agent and the binder can be appropriately adjusted in consideration of the intended use of the battery (emphasis on output, importance on energy, etc.), ion conductivity and the like.

  In producing the positive electrode, examples of the solvent used in the positive electrode active material composition include N-methylpyrrolidone, dimethylformamide, dimethylacetamide, methyl ethyl ketone, tetrahydrofuran, acetone, ethanol, ethyl acetate, and water. These solvents may be used in combination. The amount of the solvent used is not particularly limited, and may be appropriately determined according to the production method and the material to be used.

4-2. Negative electrode A negative electrode is a negative electrode active material composition containing a negative electrode active material, a dispersing solvent, a binder and, if necessary, a conductive additive, etc. supported on a negative electrode current collector. Molded.

4-2-1. Negative Electrode Current Collector As a material for the negative electrode current collector, a conductive metal such as copper, iron, nickel, silver, stainless steel (SUS) can be used. From the viewpoint of easy processing into a thin film, copper is preferable.

4-2-2. Negative electrode active material As the negative electrode active material, a conventionally known negative electrode active material used in lithium ion secondary batteries can be used as long as it can occlude and release lithium ions. Specifically, graphite materials such as artificial graphite and natural graphite, mesophase fired bodies made from coal / petroleum pitch, carbon materials such as non-graphitizable carbon, Si, Si alloys, Si-based negative electrode materials such as SiO, Sn An Sn-based negative electrode material such as an alloy, or a lithium alloy such as lithium metal or a lithium-aluminum alloy can be used.

  As a manufacturing method of the negative electrode, a method similar to the manufacturing method of the positive electrode can be employed. In addition, the same conductive auxiliary agent, binder, and material dispersing solvent as used in the positive electrode are used in the production of the negative electrode.

4-3. Separator The separator is disposed so as to separate the positive electrode and the negative electrode. There is no restriction | limiting in particular in a separator, In this invention, all the conventionally well-known separators can be used. Specific examples of the separator include a porous sheet made of a polymer that absorbs and retains a nonaqueous electrolytic solution (for example, a polyolefin microporous separator or a cellulose separator), a nonwoven fabric separator, a porous metal body, and the like. It is done. Among these, a polyolefin-based microporous separator is preferable because it has a property of being chemically stable to an organic solvent.

  Examples of the material for the porous sheet include polyethylene, polypropylene, and a laminate having a three-layer structure of polypropylene / polyethylene / polypropylene.

  Examples of the material of the nonwoven fabric separator include cotton, rayon, acetate, nylon, polyester, polypropylene, polyethylene, polyimide, aramid, glass, etc., depending on the mechanical strength required for the non-aqueous electrolyte layer, etc. The above-exemplified materials can be used alone or in combination.

4-4. Battery exterior material A battery element equipped with a positive electrode, a negative electrode, a separator, and the electrolyte solution of the present invention is housed in a battery exterior material to protect the battery element from external impact and environmental degradation when using a lithium ion secondary battery. Is done. In the present invention, the material of the battery exterior material is not particularly limited, and any conventionally known exterior material can be used. In addition, when the said compounds (1) and (2) have a hygroscopic property, it is preferable to manufacture a lithium secondary battery in an atmosphere with a dew point of -20 degrees C or less.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

Experimental example Battery characteristics evaluation Production of positive electrode sheet LiNi _1/3 Co _1/3 Mn _1/3 O ₂ (LNMC), acetylene black (AB, conductive auxiliary agent 1, manufactured by Denki Kagaku Kogyo Co., Ltd.), graphite ( Conductive aid 2, particle size D50 = 3.2 μm, specific surface area 245 m ² / g), polyvinylidene fluoride (PVdF, “KF1120”, manufactured by Kureha Corporation) in N-methyl-2-pyrrolidone (NMP) solution Mix uniformly to prepare a paste-like positive electrode mixture A (solid content ratio (mass ratio), positive electrode active material: AB: graphite: PVdF = 92: 2: 2: 4) having a solid content concentration of 67%. did.

Next, lithium dicyanooxalatoborate (LiB (CN) ₂ (C ₂ O ₄ ), the following general formula (2-2-1)) or lithium cyano (fluoro) oxalatoborate (LiBFCN) with respect to the positive electrode mixture A (C ₂ O ₄ ), the following general formula (2-1-1)) in solid content ratio (mass ratio), positive electrode active material: AB: graphite: PVdF: LiBFCN (C ₂ O ₄ ) or LiB (CN) ₂ (C ₂ O ₄ ) = 91.6: 2: 2: 4: 0.4 Kneaded to prepare paste-like positive electrode mixtures B and C. Table 1 shows the composition (solid content ratio) of the positive electrode mixtures A to C.

The obtained paste-like positive electrode mixtures A, B and C were each coated on an aluminum current collector and dried to prepare a positive electrode sheet (initial charge capacity: 2.3 mAh / cm ² ).

2. Preparation of non-aqueous electrolyte Lithium hexafluorophosphate (LiPF ₆ , manufactured by Kishida Chemical Co., Ltd., LBG grade) as an electrolyte was mixed with a mixed solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (EC: EMC = 3: 7 (volume ratio), all were dissolved in Kishida Chemical Co., Ltd., LBG grade) to prepare a 1.0 mol / L non-aqueous electrolyte.

3. Production of coin-type lithium battery Positive electrode sheet obtained by producing the positive electrode, a commercially available negative electrode sheet (negative electrode current collector: copper foil, negative electrode active material: graphite, discharge capacity: 2.4 mAh / cm ² ), and polyethylene Each made separator was punched into a circular shape (positive electrode φ12 mm, negative electrode φ14 mm). CR2032 coin-type battery parts purchased from Hosen Co., Ltd. (positive electrode case (made of aluminum clad SUS304L), negative electrode cap (made of SUS316L), spacer (1 mm thickness, made of SUS316L), wave washer (made of SUS316L), gasket (made of polypropylene) )) To produce a coin-type lithium battery. Specifically, a negative electrode cap equipped with a gasket, a wave washer, a spacer, a negative electrode sheet (installed so that the copper foil side of the negative electrode faces the spacer), and a separator are stacked in this order, and then 70 μL of the nonaqueous electrolyte solution is added. The separator was impregnated. Next, a positive electrode sheet was placed so that the surface coated with the positive electrode mixture was opposite to the negative electrode active material layer side, a positive electrode case was stacked on the sheet, and caulking was performed to produce a coin-type lithium battery.

4). Cycle characteristic test About the obtained coin-type lithium battery, using a charge / discharge test apparatus (manufactured by Instrument Center Co., Ltd.), a charge / discharge rate of 1.0 C (constant current mode), a condition of 2.75 V to 4.4 V In each charge / discharge, a cycle test was conducted with a charge / discharge pause time of 10 minutes. The results are shown in FIG.

From FIG. 1, the coin type of the present invention in which the positive electrode contains (LiB (CN) ₂ (C ₂ O ₄ )) (positive electrode mixture B), (LiBFCN (C ₂ O ₄ )) (positive electrode mixture C). The lithium battery has a high initial capacity compared to the example using the positive electrode not including any of the above compounds (1) and (2) (positive electrode mixture A), and in addition, the capacity deterioration with time is suppressed, Good cycle characteristics were exhibited.

Claims (3)

0.1 to 3 parts by mass of a compound represented by the following general formula (2) with respect to 100 parts by mass of a positive electrode mixture composed of an active material, a conductive additive, and a binder, which is a positive electrode for a battery. A positive electrode for a battery, comprising:
(Wherein, M n ⁺ represents a lithium cation, Y 'is C androgenic, hydrocarbon group having a carbon number of halogens may have a main chain having 1 to 10, or a cyano radical, n and 1 And p represents an integer of 0 to 4. ) A battery comprising the positive electrode according to claim 1 . The battery according to claim 2, which is a lithium ion secondary battery.