WO2005042466A1

WO2005042466A1 - Quaternary ammonium salt, electrolyte, electrolyte solution and electrochemical device

Info

Publication number: WO2005042466A1
Application number: PCT/JP2004/016018
Authority: WO
Inventors: Akihiro Nabeshima; Hiroaki Tokuda; Tetsuo Nishida; Megumi Tomisaki; Kazutaka Hirano
Original assignee: Otsuka Chemical Co., Ltd.; Stella Chemifa Corporation
Priority date: 2003-10-31
Filing date: 2004-10-28
Publication date: 2005-05-12
Also published as: JP4836578B2; TW200519068A; JPWO2005042466A1; TWI359127B

Abstract

Disclosed is a quaternary ammonium salt represented by the following general formula: (1) (wherein R1 and R2 may be the same or different and represent a C1-4 alkyl group; R1 and R2 may form a saturated heterocycle together with nitrogen atoms they respectively bonded to; R3 and R4 may be the same or different and represent a methyl group or an ethyl group; and X- represents an anion). Such a quaternary ammonium salt has a melting point not more than 10˚C, excellent solubility in nonaqueous organic solvents, and an exceptionally high electrical conductivity. This quaternary ammonium salt can be preferably used as an electrolyte.

Description

Specification

Quaternary ammonium salts, electrolytes, electrolytes and electrochemical devices

The present invention relates to a quaternary ammonium salt, an electrolyte, an electrolytic solution, and an electrochemical device.

Background art

[0002] In recent years, salts having a melting point below room temperature (room temperature molten salts) have been developed. Examples of such a room temperature molten salt include, for example, those represented by the general formula

[0003] [Formula 1] I +

R ^1A

R ^2A — W— R ^3A . Y "(A)

[Wherein, R ^1A , R ^2A , R ^3A and are the same or different and are each an alkyl group having 115 carbon atoms or R, 1 O— (CH 2) — (R ′ is a methyl group or ethyl Group, n is an integer of 1 to 4)

2 n

Represents a oxyalkyl group. Any two groups of R ^1A , R ^2A , R ^3A and R ^4A may form a ring. Provided that at least one of R ^{1A to} R ^4A is the above-mentioned alkoxyalkyl group. W represents a nitrogen atom or a phosphorus atom, and Y represents a monovalent aion. ] Is known (Patent Document 1).

[0005] The aliphatic ammonium salt disclosed in Patent Document 1 has excellent solubility in non-aqueous organic solvents and has a property that salt precipitation hardly occurs at low temperatures.

[0006] However, although the electric conductivity of a solution of the aliphatic ammonium salt dissolved in a non-aqueous organic solvent is satisfactory to some extent, the electric conductivity of the aliphatic ammonium salt itself is low and has not reached a satisfactory level. . Further, the aliphatic ammonium salt is poor in fluidity due to high viscosity, and is therefore suitable for an electrolytic solution of an electric device using a porous electrode that requires permeability. ,.

Patent document l: WO 02/076924 A1

Disclosure of the invention Problems the invention is trying to solve

An object of the present invention is to provide a quaternary ammonium salt having a melting point of 10 ° C. or less, high electric conductivity, and excellent solubility in a non-aqueous organic solvent. It is.

Means for solving the problem

[0008] The present inventors have intensively studied to develop a quaternary ammonium salt capable of solving the above problems. As a result, the specific quaternary ammonium salt represented by the following general formula (1), which has neither a specific description nor suggestion in Patent Document 1, has a low melting point of 10 ° C or less, It has been found that it has excellent solubility in organic organic solvents, has remarkably high electric conductivity, and can be suitably used as an electrolyte. The present invention has been completed based on such knowledge.

[0009] The present invention provides the following quaternary ammonium salts, electrolytes, electrolytes, and electrochemical devices.

1.general formula

[0010] [Formula 2]

―

q people, X (1)

R ³ OH ₂ C + CH ₂ or

[Wherein, R ¹ and R ² are the same or different and each represent a C alkyl group. R ¹ and R ² are

1-4

These may be bonded together with the nitrogen atom to which they are bonded to form a saturated heterocyclic ring. R ³ and R ⁴ are the same or different and represent a methyl group or an ethyl group. X— represents an anion. ]

A quaternary ammonium salt represented by

2. The quaternary ammonium salt according to 1 above, wherein the saturated heterocyclic ring formed by bonding together with the nitrogen atom to which R ¹ and R ² are bonded is a 3- to 5-membered saturated heterocyclic ring.

3. The quaternary ammonium salt according to the above 2, wherein the saturated heterocyclic ring formed by bonding together with the nitrogen atom to which R ¹ and R ² are bonded is a pyridine ring.

4. The quaternary ammonium salt according to the above 1, wherein R ¹ and R ² are both methyl groups.

5. X—force BF—, A1C1-—, Al C1-—, PF—, AsF—, N (CF SO) —, N (CF SO) — , C (CF SO)-, N (CF SO) (CF CO)-, CF SO-, CH SO-, CH CO-, CF

3 2 3 3 2 3 3 3 3 3 3 2

COO—, NO—, C H COO—or C H SO—, CF3BF3—, C2F5BF3— or I—

3 3 6 5 6 5 3

The quaternary ammonium salt according to any one of the above items 14 to 14.

6. The quaternary ammonium salt according to the above 5, which is X—force BF— or N (CF 2 SO 4) —.

7.general formula

[0012] [Formula 3]

[Wherein, R ¹ and R ² are the same or different and each represents a C alkyl group. R ¹ and R ² are

1-4

A quaternary ammonium salt represented by:

8. The electrolyte according to the above item 7, wherein the saturated heterocyclic ring formed by bonding to each other together with the nitrogen atom to which R ¹ and R ² are bonded is a quaternary ammonium salt which is a 3- to 5-membered saturated heterocyclic ring. .

9. The electrolyte according to the above item 8, wherein the saturated heterocyclic ring formed by bonding together with the nitrogen atom to which R ¹ and R ² are bonded is a quaternary ammonia salt which is a pyridine ring.

10. A quaternary ammonium salt in which both R ¹ and R ² are methyl groups.

11 · X— is BF—, A1C1-—, Al C1-—, PF—, AsF—, N (CF SO) —, N (CF SO)

4 4 2 7 6 6 3 2 2 3 CF2 2

―, C (CF SO) ―, N (CF SO) (CF CO) ―, CF SO―, CH SO―, CH CO―, C

2 3 2 3 3 2 3 3 3 3 3 3 2

F COO—, NO—, C H COO— or C H SO—, CF3BF3—, C2F5BF3— or Γ

3 3 6 5 6 5 3

11. The electrolyte according to any one of the above items 7 to 10, which also comprises a quaternary ammonium salt.

12. X-force BF- or N (CFSO) -quaternary ammonium salt power

4 3 2 2

The electrolyte as described.

13.Electrolyte containing one or more of the electrolytes described in any of 7-12 above 14. The electrolytic solution according to the above 13, comprising at least one of the electrolytes according to any of the above 7 to 12 and an organic solvent.

15. The electrolytic solution according to the above 14, wherein the organic solvent is at least one selected from the group consisting of cyclic carbonates, chain carbonates, nitrile compounds, and sulfonate compounds.

16. The electrolytic solution according to the above 15, wherein the organic solvent is at least one selected from the group consisting of propylene carbonate, ethylene carbonate, ethyl methyl carbonate and dimethyl carbonate.

17. An electrochemical device comprising the electrolytic solution according to 13 above.

18. The electrochemical device according to 17 above, wherein the electrochemical device is an electric double layer capacitor or a secondary battery.

[0014] Class W ammonium

In the present specification, examples of the C alkyl group represented by R ¹ and R ² include methyl

1-4

, Ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl and the like. Preferably, the C alkyl group is a methyl group.

1-4

[0015] Examples of the saturated heterocyclic ring formed combine with each other together with the nitrogen atom R ¹ and the R ² is bonded, for example, a saturated heterocyclic ring of 3-5 members. Preferred saturated heterocycles are pyrrolidine rings.

[0016] Specific quaternary ammonium cations include bis (methoxymethyl) dimethylammonium cation, N, N- (dimethoxymethyl) N-ethyl-N-methylammonium-dimethylcation, and N, N- (dimethoxymethyl). N-propyl N-methylammonium cation, N, N (dimethoxymethyl) N-butyl-N-methylammonium cation, bis (methoxymethyl) gethylammonium cation, N- (ethoxymethyl) N- (methoxymethyl) N, N dimethyl Ammonium cation, N- (ethoxymethyl) N- (methoxymethyl) N-ethyl-N-methylammonium cation, Bis (ethoxymethyl) dimethylammonium-cation, N, N— (Diethoxymethyl) N-ethyl-N —Methylammonium-cation, bis (methoxymethyl) pyrrolidium-cation, bis Ethoxymethyl) pyrrolidine - Umukachi on, N- (ethoxymethyl) N (methoxymethyl) pyrrolidine - Umukachion, bis (methoxide Shimechiru) aziridinyl free arm cation, bis (ethoxymethyl) aziridinyl free arm cation, N- (Ethoxymethyl) -N- (methoxymethyl) aziridium cation, bis (methoxymethyl) azetidium cation, bis (ethoxymethyl) azetidium cation, N (ethoxymethyl) N (methoxymethyl) Azetidium cation and the like.

As the anion represented by X—, for example, BF—, A1C1-, Al C1-, PF—, AsF—, N

4 4 2 7 6 6

(CF SO)-, N (CF SO)-, C (CF SO)-, N (CF SO) (CF CO)-, CF S

3 2 2 3 CF2 2 2 3 2 3 3 2 3 3

O-, CH SO-, CH CO-, CF COO-, NO-, CH COO-, CH SO-, CF3B

3 3 3 3 2 3 3 6 5 6 5 3

F3—, C2F5BF3—, I— and the like. Preferred anions are BF— and N (CF SO)

4 3 2 2

—

Preferred quaternary ammonium salts include, for example, bis (methoxymethyl) dimethylammoniumtetrafluoroborate, N, N— (dimethoxymethyl) N-ethyl-N-methylammonium N-N- (dimethoxymethyl) N-propyl N-methyltetrafluoroborate, N, N- (dimethoxymethyl) N-butyl-N-methyl-tetrafluoroborate Tetrafluoroborate, bis (methoxymethyl) getyl-ammonium-tetrafluoroborate, N— (ethoxymethyl) N— (methoxymethyl) N, N—dimethylammonium-dimethyltetrafluoroborate, N— (Ethoxymethyl) -N- (methoxymethyl) N-ethyl-N-methylammonium-dimethyltetrafluoroborate, bis (ethoxymethyl) dimethylammonium-dimethyltetrafluoroborate , N, N- (diethoxymethyl) N-ethyl-N-methylammonium-dimethyltetrafluoroborate, bis (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate, bis (ethoxymethyl) pyrrolidi-dimethyltetrafluoroborate , N (ethoxymethyl) N- (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate, bis (methoxymethyl) aziridi-dimethyltetrafluoroborate, N- (ethoxymethyl) N- (methoxymethyl) aziridi -Dimethyltetrafluoroborate, bis (methoxymethyl) azetidumtetrafluoroborate, N— (ethoxymethyl) N— (methoxymethyl) azetidumtetrafluoroborate, bis (methoxymethyl) Dimethylammonium-dimethylbistrifluoromethanesulfonimide, N, N- (dimethoxymethyl) N-ethyl-N Methylammo-dimethylbistrifluoromethanesulfonimide, N, N (dimethoxymethyl) N-propyl N-methylammonium-dimethylbistrifluoromethanesulfonimide, N, N— (dimethoxymethyl) N-butylammonium-dimethylbistriimide Fluoromethanesulfonimide, bis (methoxymethyl ) Jethylammo-dimethylbistrifluoromethanesulfonimide, N— (ethoxymethyl) —N— (methoxymethyl) N, N Dimethylammonium-dimethylbistrifluoromethanesulfonylimide, N- (ethoxymethyl) -N -(Methoxymethyl) N-ethyl-N-methylammonium-dimethyl bistrifluoromethanesulfonimide, bis (ethoxymethyl) dimethylammonium-dimethylbistrifluoromethanesulfonimide, N, N— (diethoxymethyl) N— Ethyl-N-methylammonium-dimethylbistrifluoromethanesulfonimide, bis (methoxymethyl) pyrrolidi-dimethylbistrifluoromethanesulfonimide, bis (ethoxymethyl) pyrrolidi-dimethylbistrifluoromethanesulfonimide, N- (Ethoxymethyl) N— (methoxymethyl) pyrrolidi-dimethylbistrifur Methanesulfonimide, bis (methoxymethyl) aziridi-dimethylbistrifluoromethanesulfonimide, N- (ethoxymethyl) N— (methoxymethyl) aziridi-dimethylbistrifluoromethanesulfonimide, bis (methoxymethyl) a Zetizum bis trifluoromethanesulfonimide, N- (ethoxymethyl) N- (methoxymethyl) azetidi-dimethylbistrifluoromethanesulfonimide and the like.

[0019] The quaternary ammonium salt of the present invention is produced by various methods. A typical method will be described using the following reaction formula.

[0020] [ _Formula 4] X _vl _

(twenty four)

_MX (5) Μχ ι

(1) (6)

[0021] [where,

R ² , R ³ , R ⁴ and X— are the same as above. X ¹ represents a halogen atom. M represents a hydrogen atom or a metal atom. ]

By reacting a tertiary amamine represented by the general formula (2) with a compound represented by the general formula (3), a quaternary ammonium salt represented by the general formula (4) is produced. By the salt exchange reaction between the quaternary ammonium salt represented by the general formula (4) and the general formula (5), the compound represented by the general formula (1) Grade ammonium salt can be produced.

In the general formula (5), M is H or an alkali metal atom such as Na, K, and Li; an alkaline earth metal atom such as Ca, Mg, and Ba; and a metal atom such as Ag. including.

[0023] The tertiary amine represented by the general formula (2) and the compound represented by the general formula (3) used as starting materials are both known substances.

[0024] The tertiary amine of the general formula (2) is synthesized according to a known method. Such methods are described, for example, in C.M.McLeod und G.M.Robinson, J.Chem.Soc, 119, 1470 (1921),

G.M.Robinson und R. Robinson, J. Chem. Soc, 123, 532 (1923), Stewert, T.D; Bradly,

W.E.J.Am.Chem.Soc, 1932, 54, 4172-4183 and the like.

[0025] The tertiary amine represented by the general formula (2) is generally a secondary amine or formaldehyde.

, Alcohol and alkali carbonate as raw materials.

[0026] These raw materials, with respect to secondary Amin 1 mol, 10 38 weight ^_0/0 formaldehyde aqueous solution or paraformaldehyde 0. 5-3 mol, preferably 0.5 6-1. 5 moles and The alcohol is used in an amount of 0.5 to 7 mol, preferably 2 to 5 mol, and the alkali carbonate is used in an amount of 0.2 to 3 mol, preferably 0.4 to 1 mol.

[0027] The reaction temperature is suitably -5 to 25 ° C when an aqueous formaldehyde solution is used, and 60 to 100 ° C when paraformaldehyde is used. The reaction is generally completed within several hours to 24 hours.

[0028] The tertiary amine represented by the general formula (2) is easily isolated from the reaction mixture by a conventional isolation means, for example, extraction, rectification and the like.

[0029] Examples of the compound represented by the general formula (3) include chloromethyl methyl ether, bromomethylinolemethynoateate, odomethinolemethynoateate, chloromethineleetinoateate, and Lomomethylethyl ether, eodomethylethyl ether and the like are included.

[0030] The reaction between the tertiary amine represented by the general formula (2) and the compound represented by the general formula (3) is performed in a solvent-free or appropriate solvent.

[0031] As the solvent to be used, known solvents can be used as long as they can dissolve the tertiary amine represented by the general formula (2) and the compound represented by the general formula (3) and do not adversely affect the reaction. Can be used widely. Such solvents include, for example, benzene, toluene, xylene and the like. Aromatic hydrocarbons; Halogenated hydrocarbons such as dichloromethane, chloroform, tetrachlorosilane, etc .; Lower alcohols such as methanol, ethanol, isopropanol, n-butanol and tert-butanol; Ketones such as acetone and methyl ethyl ketone ; Jefferies chill ether, ethers such as diisopropyl ether; _n - hexane, aliphatic hydrocarbons such as n- heptane; alicyclic hydrocarbons such as cyclohexane and the like cycloalkyl and the like. Among these, aromatic hydrocarbons such as toluene, halogenated hydrocarbons such as dichloromethane, and ketones such as acetone are preferred. Such solvents can be used alone or in combination of two or more. These solvents are preferably non-aqueous solvents.

[0032] The compound represented by the general formula (3) is generally used in an amount of 0.3 to 5 mol, preferably 0.6 to 1.2 mol, per 1 mol of the tertiary amine (2). The reaction is usually performed at −10 to 25 ° C., and is generally completed in several hours to about 24 hours.

[0033] The reaction between the quaternary ammonium salt represented by the general formula (4) obtained by the above reaction and the compound of the general formula (5) is carried out by a usual salt exchange reaction.

The compound represented by the general formula (5) used as a raw material is a known compound, for example,

CF SO H, CF SO Li ゝ CF SO Na ゝ CF SO K :, HN (CF SO), LiN (CF SO

3 3 3 3 3 3 3 3 3 2 2 3 2

), NaN (CF SO), KN (CF SO), HN (CF CF SO), LiN (CF CF SO)

2 3 2 2 3 2 2 3 2 2 2 3 2 2 2

, NaN (CF CF SO), KN (CF CF SO), HC (CF SO), LiC (CF SO),

3 2 2 2 3 2 2 2 3 2 3 3 2 3

NaC (CF SO), KC (CF SO), HN (CF SO) (CF CO), LiN (CF SO) (CF

3 2 3 3 2 3 3 2 3 3 2 3

CO), NaN (CF SO) (CF CO), KN (CF SO) (CF CO), HBF, LiBF, NaBF

3 2 3 3 2 3 4 4 4

, KBF, AgBF, HPF, LiPF, NaPF, KPF, AgPF, CF CO H, CF CO L

4 4 6 6 6 6 6 3 2 3 2 i, CF CO Na ゝ CF CO K, CH SO H, CH SO Li ゝ CH SO Na ゝ CH SO K, etc.

3 2 3 2 3 3 3 3 3 3 3 3

[0035] This salt exchange reaction is performed in an appropriate solvent. The solvent used is a solvent capable of dissolving the quaternary ammonium salt represented by the general formula (4) and the compound represented by the general formula (5) and having no adverse effect on the reaction. As long as it is publicly known, it can be widely used. Examples of such solvents include water; halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, etc .; lower alcohols such as methanol, ethanol, isopropanol, n-butanol, tert-butanol; acetone, methyl Ketones such as ethyl ketone; Esters such as tyl; and aprotic polar solvents such as dimethyl sulfoxide and dimethylformamide. Of these, lower alcohols such as methanol; halogenated hydrocarbons such as chloroform, and water are preferred. These solvents can be used alone or in combination of two or more.

[0036] Salt exchange can also be performed using ion exchange resin. An ion exchange resin is usually used as the ion exchange resin.

[0037] In the salt exchange, the aion in the resin is replaced with the desired aion in advance, and the salt is replaced by a general formula

This can be achieved by passing a solution in which (4) is dissolved through the resin. As the solvent used here, known solvents can be widely used as long as they can dissolve the general formula (4) and do not adversely affect the salt exchange reaction. Such solvents are generally water, alcohols and the like.

[0038] The use ratio of the quaternary ammonium salt represented by the general formula (4) and the compound represented by the general formula (5) is usually 0.5 mol per 1 mol of the former. It is good to be 5 mol, preferably 0.9 to 1.2 mol. Since the reaction usually proceeds rapidly, for example, the temperature of a solution in which both are dissolved in a solvent should be maintained near room temperature. Generally, the salt exchange reaction is completed in about 10 minutes to 12 hours.

[0039] The target compound obtained in each of the above reactions can be easily separated from the reaction mixture by a conventional separation means, for example, a conventional isolation and purification means such as concentration, washing, organic solvent extraction, chromatography, and recrystallization. It is isolated and purified.

[0040] From the quaternary ammonium salt represented by the general formula (4), X is BF.

Four

Specifically, the reaction conditions for producing a quaternary ammonium salt are as follows.A quaternary ammonium salt represented by the general formula (4) is dissolved in the lower alcohol, and a predetermined amount is added to this solution. Borofluoric acid, silver borofluoride or the like, and react at about room temperature for about 30 minutes. The target compound can be isolated by distilling off hydrogen halide formed by the reaction, filtering off halogen salts such as silver halide, and concentrating the filtrate under reduced pressure and drying. In addition, a known method, for example, N

2

Distillation by distillation, distillation under reduced pressure, and the like can be applied.

[0041] From the quaternary ammonium salt represented by the general formula (4), a general formula wherein X represents N (SO CF) (

2 3 2

When the reaction conditions for producing the quaternary ammonium salt represented by 1) are specifically shown, A quaternary ammonium represented by the general formula (4) is dissolved in water, and a predetermined amount of an alkali metal salt of pistrifluoromethanesulfonimide (a lithium salt of bistrifluoromethanesulfonimide, sodium Salt, potassium salt, etc.) and react at 0-25 ° C for 30 minutes. Extract the desired product with an appropriate solvent (e.g., dichloromethane, chloroform, ethyl acetate, etc.), wash the extract with water, concentrate under reduced pressure, and dry to isolate the desired compound. Can be.

[0042] Thunder solution and thunder solution

The quaternary ammonium salt of the present invention is a room temperature molten salt that is liquid at room temperature, has excellent solubility in non-aqueous organic solvents, and has high electric conductivity. Therefore, the quaternary ammonium salt of the present invention can be suitably used as an electrolyte.

In the present invention, the electrolyte itself that also forms the quaternary ammonium salt of the present invention can be used as the electrolytic solution. Further, the electrolyte which also forms the quaternary ammonium salt of the present invention can be used by mixing with an appropriate solvent.

[0044] Here, examples of the solvent include cyclic carbonates, chain carbonates, ester phosphates, cyclic ethers, chain ethers, ratatonyi conjugates, chain esters, nitrile compounds, amide compounds, and sulfone imides. And the like. These solvents are used alone or as a mixture of two or more.

[0045] Specific examples of the cyclic carbonate include ethylene carbonate, propylene carbonate, butylene carbonate and the like.

Specific examples of the chain carbonate include dimethyl carbonate, ethyl methyl carbonate, getyl carbonate and the like.

[0047] Specific examples of the phosphate ester include trimethyl phosphate, triethyl phosphate, ethyl dimethyl phosphate, and getyl methyl phosphate.

[0048] Specific examples of the cyclic ether include tetrahydrofuran, 2-methyltetrahydrofuran and the like.

[0049] Specific examples of the chain ether include dimethoxyethane.

[0050] Specific examples of ratatonyi ligated products include γ-petit mouth ratatones and the like.

[0051] Specific examples of the chain ester include methyl propionate, methyl acetate and ethyl acetate. Ruacetate, methyl formate and the like can be mentioned.

[0052] Specific examples of the nitrile conjugate include acetonitrile and the like.

Specific examples of the amido conjugate include dimethylformamide and the like.

[0054] Specific examples of the sulfone conjugate include sulfolane and methyl sulfolane.

When the quaternary ammonium salt of the present invention is used in combination with the above solvent, the concentration of the electrolyte is preferably 0.1 M or more, more preferably 0.5 M or more, and still more preferably 1 M or more. It is better to do the above.

[0056] Further, the electrolyte of the present invention can be used in combination with a known electrolyte.

[0057] Examples of known electrolytes to be used by mixing with the electrolyte of the present invention include alkali metal salts, quaternary ammonium salts, quaternary phosphonium salts, and the like.

[0058] Examples of the alkali metal salt include a lithium salt, a sodium salt, and a potassium salt. More specifically, lithium salts include lithium hexafluorophosphate, lithium borofluoride, lithium perchlorate, lithium trifluoromethanesulfonate, lithium sulfolimide, lithium lithium sulfolmethide, and the like. More specifically, examples of the sodium salt include sodium hexafluorophosphate, sodium borofluoride, sodium perchlorate, sodium trifluoromethanesulfonate, sodium sulfolimide, sodium sulfolmethide, and the like. Can be More specifically, potassium salts include potassium hexafluorophosphate, potassium borofluoride, potassium perchlorate, potassium trifluorosulfonate, potassium sulfolimide, potassium sulfolmethide, and the like. .

[0059] Examples of the quaternary ammonium salts include tetraalkylammonium salts, imidazole salts, virazolym salts, pyridium salts, triazolium salts, and pyridazim salts. It is. More specifically, tetraalkylammonium salts include, for example, tetraethylammoniumtetrafluoroborate, tetramethylammoniumtetrafluoroborate, and tetramethylammonium-tetrafluoroborate. , Tetrabutylammonium-tetrafluoroborate, triethylmethylammonium-tetrafluoroborate, trimethylethylammonium-tetrafluoroborate, dimethylgethylammonium-tetrafluoroborate , Trimethylpropylammonium tetrafluoroborate, trimethylbutylammonium Tetrafluoroborate, dimethylethylpropylammonium-tetrafluoroborate, methylethylpropylbutylammonium-tetrafluoroborate, N, N-dimethylpi-oligo-dimethyltetrafluoroborate , N-ethyl-N-methylpyrrolidi-dimethyltetrafluoroborate, N-methyl-N-propylpyrrolidiniumtetrafluoroborate, N-ethynole-N-propylpyrrolidi-dimethyltetrafluoroborate, N, N-dimethylbiveridi-dimethyltetrafluoroborate Roborate, N-methyl-N-ethylpibelidi-dimethyltetrafluoroborate, N-methyl-N-propylpibelidi-dimethyltetrafluoroborate, N-ethyl-N-propylpiberidi-dimethyltetrafluoroborate, N, N —Dimethylmorphodium tetrafluoroborate, N-methyl-N-ethylamine Examples thereof include rufolium tetrafluoroborate, N-methyl-N-propyl morpholium tetrafluoroborate, and N-ethyl-N-propyl morphodium tetrafluoroborate. More specifically, examples of the imidazolyl salt include 1,3 dimethylimidazolymtetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, and 1,3 ethylimidazolyltetrafluoroborate. Roborate, 1,2-dimethyl-3-ethylimidazolium tetrafluoroborate, 1,2 dimethyl-3 propylimidazolidium tetrafluoroborate and the like. More specifically, as the virazolidium salt, there are 1,2-dimethylpyrazolidium tetrafluoroborate, 1-methyl-2-ethylpyrazolidium tetrafluoroborate, 1-propyl 2-methylbirazoli Dumtetrafluoroborate, 1-methyl-2-butylbiazolidiumtetrafluoroborate and the like can be mentioned. More specifically, examples of the pyridi-pium salts include N-methylpyridi-p-tetrafluoroborate, N-ethylpyridi-p-tetrafluoroborate, N-propylpyridi-p-tetrafluoroborate, and N-butylpyridi-p-tetratetraborate Fluoroborate and the like. More specifically, triazolyl salts include 1-methyltriazolyltetrafluoroborate, 1-ethyltriazolyltetrafluoroborate, and 1-propyltriazolyltetrafluoroborate. And 1-butyltriazolyltetrafluoroborate. More specifically, pyridazim-dum salts include 1-methylpyridazim-dumtetrafluoroborate, 1-ethylpyridazi-dumtetrafluoroborate, 1-propylpyridazi-dumtetrafluoroborate, 1-butylpyridazi-dimethyltetrafluoroborate and the like.

Examples of the quaternary phospho-dimethyl salt include, for example, tetraethyl phospho-dimethyl tetrafluoroborate Rate, tetramethylphospho-dimethyltetrafluoroborate, tetrapropylphospho-dimethyltetrafluroborate, tetrabutylphospho-dimethyltetrafluoroborate, triethylmethionolephosphonium tetraphlenololoborate, trimethinole Ethynolephosphonium tetrafluorolenoborolate, dimethyl getyl phosphonium tetrafluoroborate, trimethylpropyl phosphonetetrafluoroborate, trimethylbutyl phospho-dimethyltetrafluoroborate, dimethyl ester Tylpropylphosphoniumtetrafluoroborate, methylethylpropylbutylphospho-dimethyltetrafluoroborate and the like can be mentioned.

[0061] In the present invention, these known electrolytes are used alone or as a mixture of two or more.

[0062] Lightning chemical device

Examples of the electrochemical device include an electric double layer capacitor, a secondary battery, and the like. The electrolyte or electrolyte of the present invention is used for known electric double layer capacitors and secondary batteries, and can be used in the same manner as the electrolyte or electrolyte.

The quaternary ammonium salt of the present invention—a solution in which the salt is dissolved in an organic solvent can be used as an electrolyte for an electrochemical device.

When a solution obtained by dissolving a quaternary ammonium salt in an organic solvent is used as an electrolyte for an electrochemical device, the electrolyte concentration is preferably 0.1 M or more, more preferably 0.5 M or more, particularly Preferably it is 1M or more. If the electrolyte concentration is less than 0.1 M, the electrical conductivity will be low, and the performance of the electrochemical device will be reduced. The upper limit of the electrolyte concentration is the concentration at which quaternary ammonium salts which are liquid at room temperature are separated from the organic solvent, and 100% if they are not separated from the organic solvent. For quaternary ammonium salts which are solid at room temperature, the upper limit is the concentration at which the salts are saturated with an organic solvent.

[0065] An electrolyte for an electrochemical device can be prepared using the quaternary ammonium salt of the present invention. The electrolytic solution obtained by the present invention can be used for an electrochemical device capable of storing electric energy by physical action or chemical action, and can be suitably used for, for example, an electric double layer capacitor and a lithium battery.

A method for preparing an electrolytic solution for an electric double layer capacitor using the quaternary ammonium salt of the present invention will be described below. When the quaternary ammonium salt of the present invention is a liquid, it is itself. Can be used as an electrolytic solution, and the salt can be used by mixing with an appropriate organic solvent. In preparing the electrolyte for the electric double layer capacitor, moisture may adversely affect the performance of the electric double layer capacitor, so the atmosphere is not mixed with air, for example, in a glove box in an inert atmosphere such as argon gas or nitrogen gas. It is preferable to carry out the preparation work. The moisture in the working environment can be managed with a dew point meter. It is preferable to set the working environment so that the dew point is 60 ° C or less. If the dew point is 60 ° C. or higher, it is not preferable that the working time is long because the electrolyte absorbs the moisture in the atmosphere and the water in the electrolyte rises. The water content in the electrolyte can be measured with a Karl Fischer meter.

[0067] When a solution of the quaternary ammonium salt of the present invention dissolved in an organic solvent is used as an electrolyte for an electrochemical device, the electrolyte concentration is determined from the viewpoint of the electrical conductivity of the electrolyte as described above. The concentration is preferably 0.1 M or more, more preferably 0.5 M or more, and particularly preferably 1 M or more. The upper limit of the electrolyte concentration is not limited as long as precipitation and separation of the electrolyte do not occur.

[0068] Here, as the organic solvent, the various solvents described above can be used. However, since the physical properties such as the dielectric constant, viscosity, and melting point differ depending on the type of the solvent, the type of the organic solvent used and the present invention are not limited. It is preferable to determine the mixing ratio of these according to the type of the quaternary ammonium salt. For example, in the case of an electrolyte composed of N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate and propylene carbonate, N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate in the electrolyte is The proportion is preferably 10-80% by weight, more preferably 15-70% by weight, even more preferably 20-60% by weight. In the case of an electrolyte consisting of N— (ethoxymethyl) N— (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate and dimethyl carbonate, N (ethoxymethyl) N— (methoxymethyl) pyrrolidium in the electrolyte The proportion of tetrafluoroborate is preferably 20-90% by weight, more preferably 30-80% by weight. In the case of an electrolyte consisting of N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate and ethyl methyl carbonate, N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate in the electrolyte ratio is preferably 30 to 90 weight ^_0/0, more preferably 40- 80 weight ^_0/0. It is also possible to use a mixture of two or more organic solvents.If a mixed solvent of dimethyl carbonate and ethyl methyl carbonate (mixing ratio is 1: 1) is used, the electrolyte The proportion of N- (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate therein is preferably 30-80% by weight.

[0069] The quaternary ammonium salt of the present invention can also be used for an electrolyte for a lithium battery.

As in the preparation of the electrolytic solution for the electric double layer capacitor, moisture adversely affects the characteristics of the lithium battery. Therefore, the working environment in which the preparation is performed is preferably in a glove box in which the dew point is controlled.

[0070] When the quaternary ammonium salt of the present invention is itself a liquid, an electrolytic solution can be obtained by dissolving a lithium salt in the quaternary ammonium salt. Further, the quaternary ammonium salt of the present invention is mixed with an appropriate organic solvent, and the lithium salt is dissolved in the mixture to obtain an electrolyte solution.

[0071] As the lithium salt, various salts can be used as described above. The type is not particularly limited as long as no lithium salt is precipitated.

[0072] The lithium salt concentration is usually 0.1 M or more and 2.0 M or less, preferably 0.15 M or more, 1.5 M or less, preferably 0.2 M or more, 1.2 M or less, particularly preferably 0.3 M or more, and 1.0 M or less. . When the lithium salt concentration is less than 0.1 M, when the charge / discharge rate is high, the lithium ions are depleted in the vicinity of the electrode, and the charge / discharge characteristics tend to deteriorate. When the lithium ion concentration exceeds 2.0 M, the viscosity of the electrolyte increases, and the electric conductivity tends to decrease.

[0073] In the present invention, it is preferable that one of the quaternary ammonium salt of the present invention and the ion forming the lithium salt contains BF-. The reason is certain

Four

However, it is thought that when tetrafluoroborate is contained, a passivation film is formed on the surface of aluminum used as a positive electrode current collector, which can suppress the elution of aluminum. I have. BF content The number of ions is 0.5% of the total number of ions in the electrolyte.

Four

It is preferable to adjust the amount to be at least 0.8%, and it is more preferable to adjust the amount to be 0.8% or more. The upper limit concentration is that the number of BF-containing ions is 100% of the total number of ions in the electrolyte.

Four

The

[0074] The electrolytic solution may be used after being diluted with an organic solvent. Examples of usable organic solvents include cyclic carbonates, chain carbonates, cyclic ethers and chain ethers. , Nitrile compounds, sulfonated compounds and the like.

[0075] Specific examples of the cyclic carbonate include ethylene carbonate and propylene carbonate. Specific examples of the chain carbonate include dimethyl carbonate, ethyl methyl carbonate and the like. Specific examples of the cyclic ether include tetrahydrofuran, hexahydropyran and the like. Specific examples of the chain ether include 1,2-dimethoxyethane. As a specific example of the nitrile conjugate, acetonitrile and the like can be mentioned. Specific examples of the sulfone compound include sulfolane.

[0076] These organic solvents can be used as a mixture. Examples of the combination include ethylene carbonate and dimethinole carbonate, ethylene carbonate and ethynolemethinole carbonate, ethylene carbonate and propylene carbonate, and ethylene carbonate and tetrahydrofuran.

[0077] The electrolytic solution used in the present invention preferably contains a specific organic additive.

[0078] Specific organic additives include, for example, ethylene carbonate, bi-lene carbonate, butylene carbonate, ethylene trithio carbonate, vinylene trithio carbonate, ethylene sulfide and the like. Of these, ethylene carbonate and vinylene carbonate are preferred. These organic additives are used alone or in combination of two or more.

[0079] By including the above specific organic additive, SEI (Solid)

A lithium ion selective permeable membrane known as Electrolyte Interface is formed, which can suppress the decomposition and insertion of the ammonium cation forming the molten salt at room temperature into the anode material, and as a result, provide stable charge and discharge characteristics of the lithium battery. Can be.

[0080] The organic additive includes a substance that also functions as a diluent.

[0081] The content of these organic additives is preferably such that the ratio of the organic additives to the total weight of the electrolyte is 1% by weight or more and 40% by weight or less, more preferably 1% by weight or more and 30% by weight or less. More preferably, it is 1% by weight or more and 20% by weight or less, most preferably 1% by weight or more and 10% by weight or less. When the content of the organic additive is 1% by weight or less, a sufficient film is not formed on the negative electrode surface, and there is a tendency that the decomposition of the ammonium cation forming the room temperature molten salt and the insertion into the negative electrode material cannot be suppressed. Occurs. [0082] An electric double layer capacitor can be suitably produced using the electrolytic solution of the present invention obtained as described above. As an example of this electric double layer capacitor, for example, the one shown in FIG. 1 can be mentioned. The shape of the electric double layer capacitor is not limited to the coin type as shown in Fig. 1, but it is a stacked type in which the electrodes are stacked and stored in a can body, and a wound type in which the electrodes are wound and stored. Or a laminate type packaged in an aluminum laminate. Hereinafter, the structure of a coin-type electric double layer capacitor will be described as an example.

FIG. 1 is a drawing showing a cross section of a coin-type electric double layer capacitor. Electrodes 1 and 2 are arranged to face each other with a separator 3 interposed therebetween, and housed in containers 4 and 5. The electrode includes a polarizable electrode portion made of a carbon material such as activated carbon and a current collector portion. The container bodies 4 and 5 are made of, for example, stainless steel, aluminum or the like which is not corroded by the electrolyte. The container bodies 4 and 5 are electrically insulated by an insulating gasket 6, and at the same time, seal the inside of the metal can body so that moisture and air from the outside of the can body do not enter. The current collector and the container body 4 of the electrode 1 and the current collector of the electrode 2 and the metal spacer 7 are in contact with each other at an appropriate pressure due to the presence of the metal spring 8, respectively. Keep in touch. In order to increase electric conductivity, the current collector may be bonded using a conductive paste such as a carbon paste.

[0084] The polarizable electrode material has a large specific surface area, a high electric conductivity, and is preferably a material, and is electrochemically stable to the electrolytic solution within the range of applied voltage to be used. It is necessary. Examples of such a material include a carbon material, a metal oxide material, and a conductive polymer material. Considering cost, the polarizable electrode material is preferably a carbon material.

[0085] As the carbon material, activated carbon materials are preferred. Specific examples thereof include sawdust activated carbon, coconut activated carbon, pitch'cotas-based activated carbon, phenol-based activated carbon, polyacrylonitrile-based activated carbon, and cellulose-based activated carbon. Forces are not limited to these.

[0086] Examples of the metal oxide-based material include, but are not limited to, ruthenium oxide, manganese oxide, manganese oxide, and the like.

[0087] Examples of the conductive polymer material include polyaline, polypyrrole film, and polythiophene. Force, such as a film and a poly (3,4-ethylenedioxythiophene) film. The present invention is not limited to these.

[0088] The electrode is formed by pressing the above-mentioned polarizable electrode material with a binder under pressure, or mixing the above-mentioned polarizable electrode material with a binder together with an organic solvent such as pyrrolidone to form a paste into an aluminum foil. Etc., and then dried after coating.

As the separator, a separator having high electronic insulation and excellent wettability of the electrolytic solution and high ion permeability is preferable, and it is necessary that the separator be electrochemically stable within an applied voltage range. The material of the separator is not particularly limited, but paper making which is strong such as rayon and manila hemp; polyolefin-based porous film; polyethylene nonwoven fabric; polypropylene nonwoven fabric and the like are preferably used.

[0090] A lithium secondary battery can be suitably prepared using the electrolyte solution of the present invention obtained as described above.

Examples of the shape of the lithium secondary battery of the present invention include a coin shape, a cylindrical shape, a square shape, and a laminate, but the shape is not limited to these shapes. As an example of the lithium secondary battery of the present invention, for example, a coin-type cell shown in FIG. 2 can be mentioned.

[0091] Hereinafter, the lithium secondary battery will be described with reference to FIG.

[0092] In an internal space formed by the positive electrode can 14 and the negative electrode can 15, a stacked body in which the positive electrode 11, the separator 13, the negative electrode 12, and the spacer 17 are stacked in this order from the positive electrode can 14 side is housed. . By interposing a spring 18 between the negative electrode can 15 and the spacer 17, the positive electrode 11 and the negative electrode 12 are appropriately crimped and fixed. The electrolyte is impregnated between the positive electrode 11, the separator 13, and the negative electrode 12. With the gasket 16 interposed between the positive electrode can 14 and the negative electrode can 15, the positive electrode can 14 and the negative electrode can 15 are crimped to join the two, thereby sealing the laminate. .

[0093] Examples of the positive electrode active material include LiCoO, LiNiO, LiNiCoO, and LiNiCoM.

2 2 1-x x 2 1-y-z y n O, LiNi Mn O, LiMnO, LiMn O, LiNi Mn O, etc.Lithium and transition z 2 0.5 0.5 2 2 2 4 0.5 1.5 4

Composite oxides with metals; oxides such as TiO and V O; sulfides such as TiS and FeS;

2 2 5 2

The power of the battery capacity and the energy density The composite oxide of lithium and a transition metal is preferable.

[0094] Here, l>x> 0, l>y> 0, 1>z> 0, and y + z <1. [0095] The positive electrode is formed by press-molding these positive electrode active materials together with a known conductive auxiliary and a binder, or by mixing the positive electrode active material together with a known conductive auxiliary and a binder with an organic solvent such as pyrrolidone. The paste can be obtained by applying a paste into a current collector, such as an aluminum foil, followed by drying.

[0096] As the negative electrode active material, lithium metal, an alloy of lithium metal and another metal, and a material into which lithium ions are inserted and desorbed are used. Examples of alloys of lithium metal and other metals include LiAl, Li—Sn, LiZn, and LiSi. Examples of the material into which lithium ions are inserted and desorbed include carbon materials obtained by firing resins and pitches, carbon materials obtained by adding a boron compound to these carbon materials, and natural graphite. These negative electrode active materials are used alone or as a mixture of two or more.

[0097] The negative electrode is formed by pressure-forming these negative electrode active materials together with a known conductive auxiliary and a binder, or by forming the negative electrode active material together with a known conductive auxiliary and a binder together with an organic solvent such as pyrrolidone. To a paste, and then apply it to a current collector such as a copper foil and then dry it.

[0098] The separator is not particularly limited as long as it is an insulator and a chemically stable material immediately after the passage of the electrolytic solution.

[0099] The quaternary ammonium salt of the present invention and an electrolytic solution containing the same are suitable as an electrolytic solution for an electrochemical device having high electric conductivity and high solubility in an organic solvent.

[0100] Examples of the electrochemical device include, but are not limited to, electric double-layer capacitors, secondary batteries, dye-sensitized solar cells, electocole chromic elements, capacitors, and the like. Particularly suitable electrochemical devices are electric double layer capacitors and secondary batteries.

The invention's effect

[0101] Since the quaternary ammonium salt of the present invention has a melting point of 10 ° C or less, it can maintain a liquid form at room temperature (25 ° C). Further, the quaternary ammonium salt of the present invention is remarkably excellent in solubility in organic solvents and has high electric conductivity.

[0102] The quaternary ammonium salt of the present invention, which is itself liquid at room temperature (25 ° C), can be used as an electrolyte as it is. This electrolyte can prevent electrolyte deposition even at low temperatures. Stable electrical conductivity can be achieved. Further, since this quaternary ammonium salt can be used as an electrolyte as it is, it is possible to increase the ion concentration of the electrolyte, and to exhibit high electrical conductivity.

[0103] The quaternary ammonium salt of the present invention, which is excellent in solubility in an organic solvent, can be dissolved in an organic solvent to form an electrolyte. The quaternary ammonium salt of the present invention does not precipitate, and there is no fear that the electric conductivity of the electrolytic solution is reduced.

[0104] The quaternary ammonium salt of the present invention is excellent in fluidity due to its low viscosity, and therefore, is suitable for use in an electrolytic solution of an electric device using a porous electrode that requires permeability. Can also be suitably used.

Brief Description of Drawings

FIG. 1 is a partial cross-sectional view of an electric double layer capacitor produced in Example 10 of the present invention.

FIG. 2 is a partial sectional view of a lithium secondary battery prepared in Example 12 of the present invention.

FIG. 3 is a graph showing the electrical conductivity of mixed solutions of various concentrations obtained in Example 6, Example 7, and Comparative Example 3 of the present invention.

Explanation of symbols

[0106] One electrode

2 electrodes

3 Separator

4 Container body

5 Container body

6 Gasket

7 Spacer

8 Spring

11 Positive electrode

12 Negative electrode

13 Porous separator

14 Positive electrode can 15 Anode can

16 Gasket

17 Spacer

18 Spring

BEST MODE FOR CARRYING OUT THE INVENTION

[0107] Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

[0108] Example 1

Synthesis of bis (methoxymethyl) dimethylammonium-tetrafluoroborate

Dimethylmethoxymethylamine 30. Og was dissolved in 120 g of toluene, and the atmosphere was replaced with nitrogen. To this solution, 16.3 g of chloromethyl methyl ether (reagent: manufactured by Tokyo Chemical Industry) was added dropwise at 5 ° C over 1 hour. The solution was stirred at 5 ° C for 10 hours to complete the reaction. The lower layer separated from the two layers was separated, washed three times with 150 g of toluene, further three times with 150 g of methyl ethyl ketone, dried under reduced pressure, and dried with 25 g of dimethyldimethoxymethylammonium. -Pemuchloride (colorless liquid) was obtained.

Next, the obtained dimethyldimethoxymethylammonium chloride was dissolved in 50 g of methanol, and 45.3 g of a 30% HBF methanol solution was added. Hydrogen chloride and excess under reduced pressure

Four

Excluding HBF, 31.9 g of the title compound (colorless liquid) was obtained.

Four

— NMR (d— CH OH) S ppm:

Three

2.98 (s, 6H), 3.65 (s, 6H), 4.59 (s, 4H).

[0110] The melting point of the quaternary ammonium salt (bis (methoxymethyl) dimethylammonium-tetrafluoroborate) obtained above was measured using a differential thermal analyzer (RIGAKU, DSC8230B) manufactured by Rigaku Corporation. Was performed using Specifically, the sample weight was 20 mg, and the sample was quenched to 150 ° C with liquid argon, and then heated at a rate of 5 ° CZ. The melting point was also determined by the intersection force between the baseline tangent and the tangent to the peak slope. The melting point of the quaternary ammonium salt obtained in Example 1 was 4 ° C.

[0111] Example 2

Synthesis of bis (methoxymethyl) pyrrolidi-dimethylbistrifluoromethanesulfonimide 300 g of methoxymethylpyrrolidine and 89.9 g of lithium bistrifluoromethanesulfonimide were dissolved in 300 g of dichloromethane, and the mixture was replaced with nitrogen. To this solution, 21. Og of chloromethyl methyl ether (reagent: manufactured by Tokyo Kasei) was added dropwise at 5 ° C for 1 hour. The temperature of the solution was gradually raised and stirred at room temperature for 4 hours to complete the reaction. 200 ml of water was added to the reaction solution, and the lower layer was separated. The obtained organic layer was washed 10 times with 50 ml of water. The organic layer was concentrated and dried under reduced pressure to obtain 97.6 g of the title compound (colorless liquid).

— NMR (CDC1) δ ppm:

Three

2.17 (m, 4H), 3.47 (m, 4H), 3.60 (s, 6H), 4.53 (s, 4H).

[0112] The melting point of the quaternary ammonium salt (bis (methoxymethyl) pyrrolidi-dimethylbistrifluoromethanesulfonylimide) obtained above was measured in the same manner as in Example 1. The melting point of the quaternary ammonium salt obtained in Example 2 could not be clearly determined. The glass transition temperature (Tg) was -90 ° C.

[0113] Comparative Example 1

N (methoxyethyl) N methylpyrrolidi-dimethyltetrafluoroborate was synthesized according to WO 02/0 76924 AU.

[0114] That is, 68.77 g of pyrrolidine and 88.02 g of 2-methoxyethyl chloride were placed in an autoclave and reacted at 90 ° C for 24 hours. After completion of the reaction, 200 ml of an aqueous solution in which 56 g of potassium hydroxide was dissolved was added, and the organic layer was separated and extracted. The aqueous layer was extracted with dichloromethane 100 (repeated twice: a total of 200 ml) and washed with saturated saline. The organic layer was dried over anhydrous potassium carbonate. After the organic layer was filtered and dichloromethane was distilled off under reduced pressure, the residue was subjected to distillation treatment to isolate 24.02 g of N (methoxyethyl) pyrrolidine.

[0115] 10.00 g of the obtained N- (methoxyethyl) pyrrolidine was dissolved in 12 ml of tetrahydrofuran, and 11.22 g of methyl iodide was added at 0 ° C. The temperature was gradually raised, and the reaction was carried out at room temperature for 24 hours. After completion of the reaction, tetrahydrofuran was distilled off under reduced pressure, and the residue was recrystallized with a mixed solvent of tetrahydrofuran Z-ethanol to obtain 17.22 g of N (methoxyethyl) N-methylpyrrolidium-dimethyl iodide.

[0116] N (methoxyethyl) N-methylpyrrolidium-dimethiodide 10.00 was dissolved in 67 ml of ultrapure water, 4.27 g of silver oxide was added, and the mixture was stirred for 3 hours. The reaction solution was filtered to completely remove the precipitate. After removal, 42% tetrafluoroboric acid was added in small portions until the pH reached 5-6. The reaction solution was freeze-dried and further dried under reduced pressure to obtain 8.26 g of N (methoxyethyl) N-methylpyrrolidi-dimethyltetrafluoroborate, which was the target substance.

The melting point of N (methoxyethyl) N-methylpyrrolidi-dimethyltetrafluoroborate obtained above was measured in the same manner as in Example 1. Melting point was 15 ° C.

[0118] Comparative Example 2

N (methoxyethyl) N, N getyl-N-methylammonium tetrafluoroborate was synthesized according to WO 02/076924 A 1 (Patent Document 1).

[0119] 35.35 g of getylamine and 43.99 g of 2-methoxyethyl chloride were placed in an autoclave and reacted at 100 ° C for 24 hours. After completion of the reaction, 100 ml of an aqueous solution in which 56 g of potassium hydroxide was dissolved was dried and the organic layer was separated and extracted. The aqueous layer was extracted with 50 ml of dichloromethane (repeated twice: 100 ml in total) and washed with saturated saline. The organic layer was dried over anhydrous potassium carbonate. After the organic layer was filtered and dichloromethane was distilled off under reduced pressure, the residue was subjected to a distillation treatment to obtain 9.20 g of 2-methoxyethylethylylamine.

[0120] N (Methoxyethyl) N, N Jethyl-N-methylammonium (9.20 g) was dissolved in tetrahydrofuran (11 ml), and methyl iodide (10.18 g) was added at 0 ° C. The temperature was gradually raised, and the reaction was carried out at room temperature for 24 hours. After completion of the reaction, tetrahydrofuran was distilled off under reduced pressure, and the residue was recrystallized with a mixed solvent of tetrahydrofuran / ethanol to obtain 17.52 g of N (methoxyethyl) N, N getyl-N-methylammonium iodide.

[0121] N (Methoxyethyl) N, N Jethyl-N-methylammonium iodide 10.OOg was dissolved in 67 ml of ultrapure water, 4.25 g of silver oxide was added, and the mixture was stirred for 3 hours. After the reaction solution was filtered to completely remove the precipitate, 42% tetrafluoroboric acid was added little by little until the pH reached 5-6. The reaction solution was freeze-dried and further dried under reduced pressure to obtain 8.20 g of N (methoxyethyl) N, N getyl-N-methylammonium tetrafluoroborate, which was the target substance.

[0122] The melting point of N (methoxyethyl) N, N getyl-N-methylammonium tetrafluoroborate obtained above was measured in the same manner as in Example 1. Melting point was 8 ° C.

[0123] Example 3

Of bis (methoxymethyl) dimethylammonium-dimethylbistrifluoromethanesulfonimide Composition

To 108.7 g of N (methoxymethyl) N, N-dimethylamine, 31.4 g of lithium bistrifluoromethanesulfonimide (reagent: manufactured by ALDRICH) was added, and the mixture was cooled to 5 ° C. To this solution, 7.8 g of chloromethyl methyl ether (reagent: manufactured by Tokyo Chemical Industry) was added dropwise over 1 hour. The reaction temperature was set to 10 ° C or less. After completion of the dropwise addition, the temperature was gradually raised, and the reaction was carried out at room temperature for 16 hours. After completion of the reaction, the mixture was concentrated and dried with a vacuum pump. Extraction was carried out with 500 g of dichloromethane and 50 Og of water. The organic layer was washed four times with 300 g of water, concentrated, and dried under reduced pressure to obtain 30.2 g of the desired product.

— NMR (d— CH OH) S ppm:

Three

2.98 (s, 6H), 3.65 (s, 6H), 4.59 (s, 4H).

[0124] The melting point of bis (methoxymethyl) dimethylammonium bistrifluoromethanesulfonimide obtained above was measured in the same manner as in Example 1.

[0125] Synthesis example 1

Synthesis of N-ethoxymethylpyrrolidine

Paraformaldehyde (reagent: manufactured by MERK) 101.2 g, potassium carbonate (reagent: manufactured by Wako Pure Chemical) 234. Og and ethyl alcohol (reagent: manufactured by Wako Pure Chemical) 971.3 g were charged, and pyrrolidine (reagent: Tokyo Chemical Industry) Og was dropped at 10 ° C or lower. It took 2 hours for the dripping. After completion of the dropwise addition, the mixture was reacted under reflux for 7 hours. Ethyl alcohol was distilled off, and the residue was distilled under reduced pressure (70 mmHg) to obtain 148.4 g of ethoxymethylpyrrolidine.

— NMR (CDC1) δ ppm:

Three

1.17 (t 3H), 1.75 (m 4H), 2.73 (m 4H), 3.49 (q 2H), 4.16 (s 2H).

[0126] Synthesis example 2

Synthesis of N- (ethoxymethyl) N- (methoxymethyl) pyrrolidi-demipark mouthrate

To 147.9 g of N ethoxymethylpyrrolidine produced in Synthesis Example 1, 59.18 g of sodium perchloride (reagent; manufactured by Wako Pure Chemical Industries) was added, and the mixture was cooled to 5 ° C. To this solution, 36.93 g of chloromethyl methyl ether (reagent: manufactured by Tokyo Chemical Industry) was added dropwise over 1 hour. The reaction temperature was lower than 10 ° C. After completion of the dropwise addition, the temperature of the reaction mixture was gradually raised, and the reaction was performed at room temperature for 12 hours. After the completion of the reaction, the mixture was filtered and washed with 100 ml of ethyl alcohol. After concentration, dichloromethane Extracted with Z water. The organic layer was washed three times with a small amount of water and concentrated. The concentrate was dissolved in ethyl alcohol and recrystallized at 50 ° C. Recrystallization was repeated 5 times. The obtained crystals were dried under reduced pressure to obtain the desired product, 83. Og.

— NMR (d— CH OH) S ppm:

Three

1.28 (t 3H), 2.16 (m 4H), 3.49 (m 4H), 3.62 (s 3H), 3.84 (q 2H), 4.61 (s 2H), 4. 66 (s 2H).

[0127] Example 4

Synthesis of N- (ethoxymethyl) N- (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate

N (Ethoxymethyl) N (methoxymethyl) pyrrolidi-pampark Molerate 30. Og prepared in Synthesis Example 2 was dissolved in 250 ml of methyl alcohol, and ion-exchange resin was used. Replaced with fluoroborate). Confirmation of the ion exchange was performed by ion chromatography (TOSOH CM-8020). After confirming the ion exchange, the methyl alcohol solution was concentrated and dried under reduced pressure to obtain 26.lg of the desired product. — NMR (d— CH OH) S ppm:

Three

1.28 (t 3H), 2.15 (m 4H), 3.48 (m 4H), 3.62 (s 3H), 3.84 (q 2H),

4.60 (s 2H), 4.65 (s 2H).

The melting point of N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate obtained as described above was measured in the same manner as in Example 1.

[0129] Example 5

Synthesis of N- (ethoxymethyl) N- (methoxymethyl) pyrrolidi-dimethylbistrifluoromethanesulfonimide

To 50.0 g of N-ethoxymethylpyrrolidine produced in Synthesis Example 1, 48.9 g of lithium bistrifluoromethanesulfonimide (reagent: manufactured by ALDRICH) was added, and the mixture was cooled to 5 ° C. To this solution, 12.5 g of chloromethyl methyl ether (reagent: manufactured by Tokyo Chemical Industry) was dropped over 1 hour. The reaction temperature was set to 10 ° C or less. After completion of the dropwise addition, the temperature of the reaction mixture was gradually raised, and the reaction was carried out at room temperature for 5 hours. After completion of the reaction, the reaction mixture was concentrated, dried with a vacuum pump, and extracted with 1300 g of dichloromethane and 1000 g of water. Wash the organic layer four times with 1000 g of water It was concentrated and dried under reduced pressure to obtain 65.9 g of the desired product.

— NMR (d— CH OH) S ppm:

Three

1.28 (t 3H), 2.15 (m 4H), 3.46 (m 4H), 3.62 (s 3H), 3.83 (q 2H), 4.59 (s 2H), 4. 64 (s2H).

[0130] The melting point of N (ethoxymethyl) N- (methoxymethyl) pyrrolidi-dimethylbistrifluoromethanesulfonylimide obtained above was measured in the same manner as in Example 1.

[0131] Test example 1

The electrical conductivity of the quaternary ammonium salts obtained in Example 15 and Comparative Examples 1 and 2 was measured.

[0132] For the measurement of electric conductivity, an electric conductivity meter manufactured by Radiometer was used. Radiometer CDC641T was used for the measurement cell at 25 ° C.

[0133] The viscosity of the quaternary ammonium salt obtained in Example 15 and Comparative Example 1 and Comparative Example 2 was measured. The viscosity was measured at 25 ° C. using a vibrating viscometer (VM-1G, manufactured by CBC Materials Co., Ltd.).

Table 1 shows the results.

[0135] [Table 1]

Quaternary ammonium salt Melting point Electrical conductivity

Anion (.c) (mS / cm) Example 1 BF4—4 6.2 96

Example 3 TFSI "8 4.8 56 Example 2 H _{3 Co.} , TFS Factory -90 (Tg) 5.4 54 Example 4 BF4"-11 5.8 74

o

Example 5 TFSI--90 (Tg) 4.9 40 Comparative Example 1 BF4 "15 2.8 258

Comparative Example 2 BF4—8 1.2 645

To CH ₃

[0136] Example 6

N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate and propylene carbonate (PC) (reagent: manufactured by Kishidai-Dogaku Co., Ltd., lithium nottery grade) produced in Example 4 were added to various concentrations. Mixing was carried out in a dry box under a nitrogen atmosphere with a dew point of 60 ° C or less. The water content of the mixed solution was measured with a Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and found to be 30 ppm or less. The concentration of N (ethoxymethyl) N (methoxymethyl) pyrrolidinium tetrafluoroborate in the mixed solution was as shown in Table 2.

[0137] Mixed solutions of various concentrations were transferred to a glass container equipped with a screw stopper in a dry box at 4ml intervals and taken out of the dry box. The glass containers containing the various solutions were immersed in a thermostat and kept at 25 ° C for 5 hours. [0138] Example 7

The bis (methoxymethyl) dimethylammoniumtetrafluoroborate produced in Example 1 and propylene carbonate (PC) (reagent: manufactured by Kishida Chemical Co., Ltd., lithium battery grade) at various concentrations. As described above, mixing was performed in a dry bot- tom in a nitrogen atmosphere having a dew point of 60 ° C or less. The water content of the mixed solution was measured with a Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and confirmed to be 30 ppm or less. The concentration of bis (methoxymethyl) dimethylammonium-tetrafluoroborate in the mixed solution was as shown in Table 3.

[0139] The mixed solutions having various concentrations were transferred to a glass container provided with a screw stopper in a dry box in an amount of 4 ml each and taken out of the dry box. The glass containers containing the various solutions were immersed in a thermostat and kept at 25 ° C for 5 hours.

[0140] Comparative Example 3

N- (methoxyethyl) N, N getyl-N-methylammonium-tetrafluoroborate and propylene carbonate (PC) (Liquid nottery grade, manufactured by Kishidai Tangaku Co., Ltd.) produced in Comparative Example 2 Was mixed in a dry box in a nitrogen atmosphere with a dew point of 60 ° C or less. The water content of the mixed solution was measured with a Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and found to be 30 ppm or less. The concentration of N (methoxyethyl) N, N getyl-N-methylammonium-tetrafluoroborate in the mixed solution was as shown in Table 4.

[0141] The mixed solutions having various concentrations were transferred to a glass container equipped with a screw stopper in a dry box in an amount of 4 ml, and taken out of the dry box. The glass containers containing the various solutions were immersed in a thermostat and kept at 25 ° C for 5 hours each.

After observing the mixed state of the various solutions, the various solutions were again taken out of the dry box, and the electric conductivity was measured. For the measurement of electric conductivity, a conductivity meter (manufactured by CDM210 Radiometer) was used. XE-100 (manufactured by Radiometer) was used as a measurement cell. The results are shown in Tables 2, 3, 4 and 3.

[0142] [Table 2] N— (ethoxydimethyl) N— (methoxymeth

Chill) pyrrolidinium tetrafluorobo conductivity

Rate (, mS / cm)

0.5 8.1

1 12.4

1.5 14.1

2 14.6

2.5 13.3

3 12.4

[Table 3] Bis (methoxymethyl) dimethylammonium

Conductivity

Mutetrafluoroborate

(mSZ cm)

; Tatsunari (Μ)

0.5 8.8

1 12.7

1.5 13.9

2 14.3

2.5 13.6

3 1 1.9

[0144] [Table 4]

Ν— (Methoxyethyl) Ν—Jetil

Ν—methylammonium tetrafluorobo conductance

(mS / cm)

Rate Concentration (Μ)

0.6 8.5

1.1 1 1.8

1.7 12.6

2.2 12.0

2.8 10.4

3.3 8.5 Example 8

N (ethoxymethyl) N (methoxymethyl) pyrrolidinium tetrafluoroborate and ethyl methyl carbonate (EMC) (reagent: manufactured by Kishida Chemical Co., Ltd., lithium battery grade) produced in Example 4 were prepared at various concentrations. The dew point is 60 ° C or less. The mixture was mixed in a dry box under an atmosphere. The water content of the mixed solution was measured with a Karl Fischer water meter (manufactured by Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and found to be 30 ppm or less. The concentration of N (ethoxymethyl) N (methoxymethyl) piperidiniumtetrafluoroborate in the mixed solution was as shown in Table 5.

[0146] Each mixed solution was transferred to a glass container provided with a screw stopper in an amount of 4 ml each in a dry box, and was taken out of the dry box. The glass containers containing the various solutions were immersed in a thermostat and kept at 25 ° C for 5 hours.

[0147] Comparative Example 4

N- (methoxyethyl) N, N getyl-N-methylammonium tetrafluoroborate and ethyl methyl carbonate (EMC) (reagent: manufactured by Kishidai-Dogaku Co., Ltd., lithium nottery grade) produced in Comparative Example 2 were Mixing was performed in a nitrogen atmosphere dry box with a dew point of 60 ° C or less to obtain various concentrations. The water content of the mixed solution was measured with a Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and confirmed to be 30 ppm or less. The concentration of N (methoxyethyl) N, N getyl-N-methylammonium tetrafluoroborate in the mixed solution was as shown in Table 6.

[0148] Comparative Example 5

N (methoxyethyl) N methylpyrrolidi-dimethyltetrafluoroborate and ethyl methyl carbonate (EMC) (reagent: manufactured by Kishida Chemical Co., Ltd., lithium nottery grade) produced in Comparative Example 1 were prepared at various concentrations. Mixing was performed in a nitrogen atmosphere dry box with a dew point of 60 ° C or less. The water content of the mixed solution was measured with a Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and confirmed to be 30 ppm or less. The concentration of N (methoxyethyl) N methylpyrrolidi-dimethyltetrafluoroborate in the mixed solution was as shown in Table 7.

[0149] Each mixed solution was transferred to a glass container provided with a screw stopper in an amount of 4 ml in a dry box and taken out of the dry box. The glass containers containing the various solutions were immersed in a thermostat and kept at 25 ° C for 5 hours.

Observe the mixed state of the various solutions. The electric conductivity was measured in the same manner as described above. The results are shown in Table 5-7.

[0150] [Table 5]

[0151] [Table 6]

[0152] [Table 7]

Example 9

To N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethylbis (trifluoromethanesulfol) imide obtained in Example 5, lithium bis (trifluoromethanesulfol) imide (LiTFSI) was added at 0.5 M or 1. Mix to OM concentration. If the dew point is below 60 ° C The mixture was mixed in a dry box under an atmosphere. The water content of the mixed solution was measured with a Karl Fischer water meter (manufactured by Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and found to be 30 ppm or less.

[0154] Comparative Example 6

N (Methoxyethyl) N, N Jethyl-N-methylammonium-dimethylbis (trifluoromethylsulfonyl) imide (reagent: Kanto-Danigaku Co., Ltd. for material research) is dried under reduced pressure (water content: 20 ppm or less), and lithium bis (trifluoromethyl) Lomethanesulfol) imide (LiTFSI) was added to a concentration of 0.5M or 1.OM, and mixed in a nitrogen atmosphere dry box with a dew point of 60 ° C or less. The water content of the mixed solution was measured with a Karl Fischer moisture meter (Hiranuma Sangyo Co., Ltd., Hiranuma Trace Moisture Analyzer AQ-7) and confirmed to be 30 ppm or less.

After observing the mixed state of the various solutions, the solutions were again taken out of the dry box, and the electric conductivity was measured in the same manner as described above. Table 8 shows the results.

[Table 8]

Example 10 (Production of Electric Double Layer Capacitor)

From the mixed solution (electrolyte solution) produced in Example 6, the following electric double layer capacitor was prepared using a mixed solution of N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethyltetrafluoroborate at a concentration of 2M. did.

[0157] Electrode 1 and electrode 2 are made of a conductive material mainly composed of activated carbon, a binder, and N-methylbiphenyl. A paste obtained by kneading with mouth lidone was coated on an aluminum foil to a thickness of 150 μm, and then dried, and the obtained sheet electrode was cut into a disk shape.

[0158] The container body 4, the container body 5, the spacer 7, and the spring 8 are all made of stainless steel, and the separator 7 is a polypropylene non-woven fabric.

[0159] The electric double layer capacitor was assembled in a glove box filled with argon gas. The electrode 1, the electrode 2, the container 4, the container 5, the spring 8, and the spacer 7 were vacuum-dried under heating at 120 ° C. for 24 hours, and then taken into a glove box. Electrode 1, electrode 2 and separator 3 were impregnated with the mixed solution (electrolyte solution for electric double layer capacitor) obtained in Example 6. The electrode separator 3, the electrode 2, the spacer 7, and the spring 8 are placed in this order on the container 4 so that the configuration shown in FIG. 1 is obtained, and the gasket 6 is inserted. The container body 5 was placed on the top. The opening of the container body 4 was sealed by bending inward to form an electric double layer capacitor.

[0160] After the coin-type electric double layer capacitor prepared above was set in a dedicated holder, charging and discharging of the electric double layer capacitor were started. The constant current charging was performed at a current density of 2.0 mA, and the voltage was switched to the constant voltage charging when the voltage reached 2.5 V. After holding at 2.5 V for 120 minutes, a constant current discharge of 2.0 mA was performed, and when the voltage reached OV, switching to low-voltage discharge was performed and the charge and discharge characteristics were examined by holding at 0 V for 120 minutes. As a result, the electric double layer capacitor of the present invention prepared in Example 10 exhibited good charge / discharge characteristics.

Example 11 (Preparation of electrolyte solution for lithium secondary battery)

5% by weight of N (ethoxymethyl) N (methoxymethyl) pyrrolidi-dimethylbis (trifluoromethanesulfonyl) imide prepared in Example 5, lithium bistrifluoromethanesulfonimide (LiTFSI) O.5M as lithium salt A non-aqueous electrolyte is prepared by using 5wt% of bi-lene carbonate (VC) as a non-aqueous solvent and ethylene carbonate (EC) Z-ethyl methyl carbonate (EMC) = 1,3 (V / V) did.

Example 12 (Production of lithium secondary battery)

A coin-type nonaqueous electrolyte lithium secondary battery as shown in FIG. 2 was produced. In FIG. 2, 11 is a positive electrode, 12 is a negative electrode, 13 is a porous separator, 14 is a positive electrode can, 15 is a negative electrode can, 16 is a gasket, 17 is a spacer, and 18 is a spring. [0163] The nonaqueous electrolyte lithium secondary battery shown in Fig. 2 was prepared in the following procedure.

[0164] Preparation of negative electrode 12:

Natural graphite and polyvinylidene fluoride (PVdF) as a binder were mixed at a weight ratio of 9: 1, and N-methylpyrrolidone was added thereto to obtain a paste. This paste was uniformly applied on a 22-m-thick copper foil using an applicator for electrode application. This was vacuum-dried at 120 ° C. for 8 hours, and a negative electrode 12 having a diameter of 16 mm was obtained using an electrode punching machine.

[0165] Preparation of positive electrode 11:

LiCoO powder, conductive additive acetylene black and binder PVdF 90: 5: 5 weight

2

And N-methylpyrrolidone was added to the mixture to obtain a paste. This paste was vacuum dried at 120 ° C. for 8 hours, and a positive electrode 11 having a diameter of 16 mm was obtained with an electrode punching machine.

[0166] The positive electrode 11 was placed on the bottom surface of the positive electrode can 14, and the porous separator 13 was placed thereon. Then, the non-aqueous electrolyte prepared in Example 11 was injected, and the gasket 16 was inserted. Thereafter, the negative electrode 12, the spacer 17, the spring 18, and the negative electrode can 15 are sequentially placed on the separator 13, and the positive electrode can 14 is removed using a coin crimper machine. The opening was closed by bending inward to form a non-aqueous electrolyte lithium secondary battery.

[0167] The battery prepared as described above was evaluated as follows. The battery was charged at a constant current of 0.4 mA, and when the voltage reached 4. IV, the battery was charged at a constant voltage of 4. IV for 1 hour. Discharging was performed at a constant current of 1. OmA until the voltage reached 3V. When the voltage reached 3V, it was held at 3V for 1 hour, and the charge / discharge characteristics were examined. As a result, the secondary battery of the present invention prepared in Example 11 showed good cycle characteristics.

Claims

Claims [1] General formula

[Chemical 1]

_

roH ₂ c + c strike ⁴

1-4

A quaternary ammonium salt represented by

[2] A saturated heterocyclic ring formed by bonding together with the nitrogen atom to which R ¹ and R ² are bonded is 3—

2. The quaternary ammonium salt according to claim 1, which is a 5-membered saturated heterocycle.

[3] The quaternary ammonium salt according to claim 2, wherein the saturated heterocyclic ring formed by bonding together with the nitrogen atom to which R ¹ and R ² are bonded is a pyrrolidine ring.

[4] The quaternary ammonium salt according to claim ^1, wherein R ¹ and R ² are both methyl groups.

[5] X—force BF—, A1C1-—, Al C1-—, PF—, AsF—, N (CF SO) —, N (CF SO) —,

4 4 2 7 6 6 3 2 2 3 CF2 2 2

C (CF SO)-, N (CF SO) (CF CO)-, CF SO-, CH SO-, CH CO-, CF

3 2 3 3 2 3 3 3 3 3 3 2 3

COO—, NO—, C H COO—or C H SO—, CF3BF3—, C2F5BF3— or I—

3 6 5 6 5 3

15. The quaternary ammonium salt according to claim 14.

[6] The quaternary ammonium salt according to claim 5, which is X—force BF— or N (CF 2 SO 4) —.

4 3 2 2

[7] General formula

[Chemical 2]

1-4

A quaternary ammonium salt represented by:

[8] A saturated heterocyclic ring formed by bonding together with the nitrogen atom to which R ¹ and R ² are bonded is 3—

The electrolyte according to claim 7, which is a quaternary ammonium salt which is a 5-membered saturated heterocycle.

[9] The electrolyte according to claim 8, wherein the saturated heterocyclic ring formed by bonding to each other together with the nitrogen atom to which R ¹ and R ² are bonded is a quaternary ammonium salt which is a pyrrolidine ring.

[10] The electrolyte according to claim 7, wherein R ¹ and R ² are both methyl groups.

[11] X—force BF—, A1C1-—, Al C1-—, PF—, AsF—, N (CF SO) —, N (CF SO) —,

4 4 2 7 6 6 3 2 2 3 CF2 2 2

C (CF SO)-, N (CF SO) (CF CO)-, CF SO-, CH SO-, CH CO-, CF

3 2 3 3 2 3 3 3 3 3 3 2 3

COO—, NO—, C H COO—or C H SO—, CF3BF3—, C2F5BF3— or I—

3 6 5 6 5 3

The electrolyte according to any one of claims 7 to 10, which also comprises a quaternary ammonium salt.

[12] A quaternary ammonium salt which is X—force BF— or N (CF SO) — according to claim 11,

4 3 2 2

The electrolyte as described.

[13] An electrolytic solution containing one or more of the electrolytes according to any one of claims 7 to 12.

[14] The electrolytic solution according to claim 13, comprising at least one of the electrolytes according to any of claims 7 to 12 and an organic solvent.

[15] The electrolytic solution according to claim 14, wherein the organic solvent is at least one selected from the group consisting of cyclic carbonates, chain carbonates, nitrile compounds and sulfone compounds.

[16] The electrolytic solution according to claim 15, wherein the organic solvent is at least one selected from the group consisting of propylene carbonate, ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate.

[17] An electrochemical device comprising the electrolytic solution according to claim 13.

[18] The electrochemical device according to claim 17, which is an electric double layer capacitor or a secondary battery.