JP2005104845A - Quaternary ammonium ambient-temperature molten salt and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel quaternary ammonium ambient-temperature molten salt which is useful as an electrolyte salt and an electrolytic solution of electrochemical devices such as a secondary cell, an electrical double layer capacitor, a fuel cell, a dye sensitizing solar cell, and furthermore a solvent for organic synthesis. <P>SOLUTION: The quaternary ammonium ambient-temperature molten salt represented by formula (1) (wherein R<SB>1</SB>to R<SB>5</SB>are each independently a 1-4C alkyl group; n is an integer of 1-6; and A is an anion) is obtained by reacting a tertiary diamino compound with an alkylating agent and thereafter subjecting the product to anion exchange. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a quaternary ammonium-based room temperature molten salt and a method for producing the same. The quaternary ammonium-based room temperature molten salt of the present invention is useful as an electrolyte, an electrolyte solution, and a solvent for organic synthesis in electrochemical devices such as secondary batteries, electric double layer capacitors, fuel cells, and dye-sensitized solar cells. It is.

  Room temperature molten salt, also called ionic liquid, is liquid near room temperature, has a low vapor pressure over a wide temperature range, and is more compatible with other substances such as organic solvents than crystalline salts. Therefore, it has been developed as an electrolyte for an electrochemical device, an electrolytic solution, or a solvent for organic synthesis.

  As for the cation component of the room temperature molten salt, imidazolium-based cations such as 1-ethyl-3-methylimidazolium or pyridinium-based cations such as 1-butylpyridinium have been mainly studied so far (for example, A large number of room temperature molten salts in which various anions such as bis (trifluoromethylsulfonyl) imide (for example, see Patent Document 2) are combined are synthesized.

  On the other hand, for quaternary ammonium cations other than imidazolium and pyridinium, tetraalkyl quaternary ammonium (for example, see Patent Document 3), quaternary ammonium containing an alkoxyalkyl group (for example, see Patent Document 4), and the like. Although it has been reported, the number of reported cases is remarkably small compared to imidazolium and pyridinium systems.

JP-A-11-307121

JP-A-8-259543 Japanese Patent No. 2981545 International Publication No. 02/076924 Pamphlet

  Cyclic amidinium compounds such as imidazolium-based or pyridinium-based compounds can be made into a room temperature molten salt relatively easily by combining with an appropriate anion species, and have a characteristic of exhibiting high electrical conductivity. There is a disadvantage that the withstand voltage is low. For example, in the case of an electrolyte of a lithium secondary battery, the imidazolium salt is decomposed at a noble potential and inferior in stability to lithium, and in the case of an electrolyte of an electric double layer capacitor, the potential is low. There is a problem that the window becomes narrow and a sufficient operating voltage cannot be obtained. Furthermore, imidazolium-based and pyridinium-based cations are problematic in that the synthesis is complicated and expensive.

  In addition, quaternary ammonium compounds such as tetraethylammonium salts are often used as electrolytes for electric double layer capacitors, etc., but have sufficient solubility in organic solvents such as propylene carbonate, which exhibit suitable performance as electrochemical devices. However, the amount of addition is limited because crystals are likely to precipitate particularly at low temperatures.

  On the other hand, tetraalkyl ammonium cations can be made liquid at room temperature by a combination of specific anions such as bis (fluoroalkylsulfonyl) imide anion, but generally the melting point tends to be high.

  Furthermore, regarding organic synthesis solvents, development of low-volatile and flame-retardant solvents is desired.

  The present invention has been made in view of the above problems, and its purpose is to exhibit a liquid state at room temperature, and an electrolyte salt or electrolyte solution of an electrochemical device such as a secondary battery or an electric double layer capacitor, or an organic synthesis. It is to provide a quaternary ammonium-based room temperature molten salt useful as a solvent for the use.

  As a result of intensive studies to solve the above-described problems, the present inventors have found that the following general formula (1)

（式中、Ｒ_１〜Ｒ_５は各々独立して炭素数１〜４のアルキル基を示し、ｎは１〜６の整数を示し、Ａはアニオンである。）
で表される化合物が、室温で液状を呈し、かつ、高いイオン伝動性を示し、電気化学デバイスの電解質塩や電解液として、さらには有機合成用の溶媒として有用であることを見い出し本発明を完成させるに至った。

(Wherein R _{1 to} R ₅ each independently represents an alkyl group having 1 to 4 carbon atoms, n represents an integer of 1 to 6, and A represents an anion.)
The present invention has been found to be useful as an electrolyte salt or an electrolytic solution for electrochemical devices, and further as a solvent for organic synthesis, exhibiting a liquid state at room temperature and exhibiting high ionic conductivity. It came to complete.

That is, the present invention
1. A quaternary ammonium-based room temperature molten salt represented by the following general formula (1):

（式中、Ｒ_１〜Ｒ_５は各々独立して炭素数１〜４のアルキル基を示し、ｎは１〜６の整数を示し、Ａはアニオンである。）
２．下記一般式（９）

(Wherein R _{1 to} R ₅ each independently represents an alkyl group having 1 to 4 carbon atoms, n represents an integer of 1 to 6, and A represents an anion.)
2. The following general formula (9)

（式中、Ｒ_１〜Ｒ_４は各々独立して炭素数１〜４のアルキル基を示し、ｎは１〜６の整数である。）
で表される３級ジアミノ化合物とアルキル化剤を反応させ、その後、生成物をアニオン交換することを特徴とする上記一般式（１）で表される４級アンモニウム系常温溶融塩の製造法、
３．上記一般式（１）で表される４級アンモニウム系常温溶融塩からなる電気化学デバイス用電解質塩、並びに
４．上記一般式（１）で表される４級アンモニウム系常温溶融塩からなる電気化学デバイス用電解液、
である。

_(Wherein, R 1 to R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, n represents an integer from 1 to 6.)
A method for producing a quaternary ammonium-based room-temperature molten salt represented by the above general formula (1), characterized in that a tertiary diamino compound represented by the formula (I) is reacted with an alkylating agent, and then the product is subjected to anion exchange,
3. 3. an electrolyte salt for an electrochemical device composed of a quaternary ammonium-based room temperature molten salt represented by the general formula (1), and An electrolytic solution for an electrochemical device comprising a quaternary ammonium-based room temperature molten salt represented by the general formula (1),
It is.

  Hereinafter, the present invention will be described in detail.

The quaternary ammonium-based room temperature molten salt of the present invention is a compound represented by the above general formula (1). In the general formula (1), each of the substituents R _{1 to} R ₅ independently represents an alkyl group having 1 to 4 carbon atoms, and specifically includes a methyl group, an ethyl group, an n-propyl group, and i-propyl. Group, n-butyl group, i-butyl group and the like. n represents an integer of 1 to 6, and A is an anion.

  Although it does not specifically limit as a quaternary ammonium cation used for the quaternary ammonium type normal temperature molten salt of this invention, For example, (2-dimethylaminoethyl) trimethylammonium, (2-dimethylaminoethyl) ethyldimethyl Ammonium, (2-diethylaminoethyl) triethylammonium, (2-diethylaminoethyl) diethylmethylammonium, (3-dimethylaminopropyl) trimethylammonium, (3-dimethylaminopropyl) ethyldimethylammonium, (3-diethylaminopropyl) triethylammonium , (3-diethylaminopropyl) diethylmethylammonium, (4-dimethylaminobutyl) trimethylammonium, (4-dimethylaminobutyl) ethyldimethylammonium, 4-diethylaminobutyl) triethylammonium, (4-diethylaminobutyl) diethylmethylammonium, (6-dimethylaminohexyl) trimethylammonium, (6-dimethylaminohexyl) ethyldimethylammonium, (6-diethylaminohexyl) triethylammonium, (6 -Diethylaminohexyl) diethylmethylammonium and the like are preferable. By applying such a quaternary ammonium cation, in the combination with a wide range of counter anions, the melting point is 50 ° C. or lower, and a molten salt can be formed in a low temperature region of 50 ° C. or lower.

The anion A used in the quaternary ammonium-based room temperature molten salt of the present invention is not particularly limited, but an anion having a low melting point in combination with the cation of the present invention is preferably used. As such an anion, for example, the following general formula (2)
RfSO ₃ ⁻ (2)
(Wherein Rf represents a fluoroalkyl group)
A fluoroalkylsulfonate anion represented by the general formula (3):
(RfSO ₂ ) ₂ N ⁻ (3)
(Wherein Rf has the same definition as above)
A bis (fluoroalkylsulfonyl) imide anion represented by the following general formula (4):
(RfSO ₂ ) ₃ C ⁻ (4)
(Wherein Rf has the same definition as above)
Tris (fluoroalkylsulfonyl) carbanion represented by the following general formula (5)
(FSO ₂ ) ₂ N ⁻ (5)
Bis (fluorosulfonyl) imide anion represented by the following general formula (6)
(RfCO) ₂ N ⁻ (6)
(Wherein Rf has the same definition as above)
Bis (fluoroalkylcarbonyl) imide anion represented by the following general formula (7)
^{_{(RfSO 2) N - (CORf}} ) (7)
(Wherein Rf has the same definition as above)
A (fluoroalkylsulfonyl) (fluoroalkylcarbonyl) imide anion represented by the general formula (8):
RfCOO ⁻ (8)
(Wherein Rf has the same definition as above)
And the like, and the like. Specifically, trifluoromethanesulfonate, bis (trifluoromethylsulfonyl) imide, bis (pentafluoroethylsulfonyl) imide, tris (trifluoromethylsulfonyl) carbanion, bis (fluorosulfonyl) imide, bis (trifluoromethylcarbonyl) Preferable examples include anions such as imide, (trifluoromethylsulfonyl) (trifluoromethylcarbonyl) imide, and trifluoroacetic acid. These anions may be used alone or in combination of two or more.

  There is no restriction | limiting in particular about the manufacturing method of the quaternary ammonium salt of this invention, Various methods can be used. For example, the N, N, N ′, N′-tetraalkylalkylenediamine compound represented by the above general formula (9) is subjected to monoalkyl quaternary chlorination, and then the product is subjected to anion exchange so that the quaternary ammonium of the present invention A normal temperature molten salt can be produced.

In the general formula (9), each of the substituents R _{1 to} R ₄ independently represents an alkyl group having 1 to 4 carbon atoms, specifically, methyl group, ethyl group, n-propyl group, i-propyl. Group, n-butyl group, i-butyl group and the like. Moreover, n shows the integer of 1-6. In the method of the present invention, the compound represented by the general formula (9) is not particularly limited. For example, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N ′, N′-tetramethyl-1,3-propanediamine, N, N, N ′, N′-tetraethyl-1,3-propanediamine, N, N, N ', N'-tetramethyl-1,4-butanediamine, N, N, N', N'-tetraethyl-1,4-butanediamine, ethylethylenediamine, N, N, N ', N'-tetramethyl- Examples include 1,6-hexanediamine, N, N, N ′, N′-tetraethyl-1,6-hexanediamine, and the like.

  In the method of the present invention, for monoalkyl quaternary chlorination, a method using a dialkyl carbonate, a method using an alkyl halide, a method using a sulfuric acid alkyl ester, a carboxylic acid alkyl ester, or the like can be employed.

  Although it does not specifically limit as a monoalkyl quaternary chlorination reaction by a dialkyl carbonate, For example, the following methods can be taken. That is, with respect to the compound represented by the general formula (9), usually 0.1 to 3 times the molar amount, more preferably 0.5 to 1.2 times the molar amount of the dialkyl carbonate is used without solvent or methanol, In the presence of an organic solvent such as ethanol, n-propanol, i-propanol, ethylene glycol, diethylene glycol, ethylene carbonate, propylene carbonate, acetonitrile, tetrahydrofuran, dioxane, toluene, xylene and the like, usually at a temperature of 80 to 150 ° C. under normal pressure or The alkyl carbonate salt of the ammonium cation represented by the general formula (1) can be obtained by carrying out the reaction under a pressure of 1 to 100 hours under pressure using an autoclave. Examples of the dialkyl carbonate include dimethyl carbonate, diethyl carbonate, and di-n-propyl carbonate.

  Further, when alkyl halide is used as a quaternizing agent, the reaction can be carried out by, for example, the following method, although not particularly limited. That is, with respect to the compound represented by the general formula (9), the alkyl halide is usually reacted in an amount of 0.1 to 3 times mol, more preferably 0.5 to 1.2 times mol. Although it does not specifically limit as a reaction solvent, Ether solvents, such as a solvent from which a halogen salt precipitates by monoalkyl quaternary chloride, for example, diethyl ether, dibutyl ether, tetrahydrofuran, a dioxane, are used suitably. The reaction usually proceeds at a temperature of 0 to 120 ° C. under normal pressure or under pressure for 0.5 to 50 hours, and the halogen of the quaternary ammonium cation used in the quaternary ammonium room temperature molten salt of the present invention. A salt can be obtained. Examples of the alkyl halide used in the reaction include iodomethane, bromomethane, chloromethane, iodoethane, bromoethane, chloroethane, 1-iodopropane, 1-bromopropane, 1-chloropropane, 2-iodopropane, 2- Examples include bromopropane, 2-chloropropane, 1-iodobutane, 1-bromobutane, and 1-chlorobutane.

  The quaternary ammonium salt thus obtained can be easily exchanged for a desired anion, and in particular the product salt has a hydrophobic fluoroalkanesulfonate anion, fluoroalkanesulfonylimide anion, fluoroalkanesulfonylcarboanion, trifluoroalkyl. With a carboxylate anion or the like, the by-product salt can be easily removed by washing with water. For example, the conversion from an alkyl carbonate salt to a bis (fluoroalkanesulfonyl) imide salt is performed using an equimolar amount of quaternary ammonium methyl carbonate salt and an alkali metal salt of bis (fluoroalkanesulfonyl) imide at room temperature, water, or The reaction proceeds immediately by mixing in the presence of an organic solvent miscible with water, and carbon dioxide gas is generated. The alkali metal carbonate by-produced can be easily removed by washing with water. Anion exchange from halogen salts and sulfates can also be performed in the same manner.

  The quaternary ammonium-based room temperature molten salt of the present invention shows a liquid state in the room temperature region and exhibits high ionic conductivity, so that it can be used for secondary batteries, electric double layer capacitors, fuel cells, dye-sensitized solar cells, etc. In an electrochemical device, it can be used as an electrolyte salt or an electrolytic solution. In addition, for use as an electrolytic solution, it can be used in a state dissolved in an organic solvent in addition to a room temperature molten salt alone.

  The solvent constituting the electrolytic solution is not particularly limited as long as it can dissolve the quaternary ammonium-based room temperature molten salt of the present invention and is stable in the operating voltage range of the electrochemical device, In general, a solvent that dissolves the electrolyte well, has a high dielectric constant, has a low viscosity, and has a high boiling point is preferable. Specific examples include ethylene carbonate, propylene carbonate, γ-butyrolactone, N-methylpyrrolidone, dimethyl carbonate, diethyl carbonate, ethylene glycol, propylene glycol, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, and sulfolane. These solvents may be used alone or in combination of two or more.

  Although it does not specifically limit about the density | concentration of the quaternary ammonium salt at the time of using as electrolyte solution, Preferably it is 0.1 mol / l or more from a performance surface, More preferably, it uses as 0.5 mol / l or more.

  In the electrolytic solution of the present invention, an electrolyte other than the quaternary ammonium-based room temperature molten salt of the present invention may be used in combination. Such an electrolyte is not particularly limited as long as it can be used for an electrochemical device such as a secondary battery, an electric double layer capacitor, a fuel cell, and a dye-sensitized solar cell. In addition, when the quaternary ammonium-based room temperature molten salt of the present invention is used as an electrolyte for a lithium secondary battery, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium bis (trifluoromethylsulfonyl) imide, perchloric acid It is preferable to add a lithium salt such as lithium.

  Further, the quaternary ammonium-based room temperature molten salt of the present invention has high polarity and dissolves many substances such as organic compounds and polymer compounds, and is therefore useful as a reaction solvent, extraction, and separation solvent for organic synthesis. Applicable reactions include, for example, olefin polymerization / dimerization, hydrogenation, oxidation, aromatic alkylation, metathesis reaction, carbonylation reaction, Heck reaction, hydroformylation, disproportionation, Friedel-Craft reaction, Diess Alder reaction , Telomerization, Wittig reaction, Billis-Hillman reaction and the like.

  As described above, the quaternary ammonium-based room temperature molten salt of the present invention is liquid near room temperature, exhibits high electrical conductivity, and exhibits high solubility in an organic solvent for an electrolytic solution. It is extremely useful as an electrochemical device such as an electric double layer capacitor, a fuel cell, and a dye-sensitized solar cell, and further as a solvent for organic synthesis.

  Hereinafter, although it demonstrates concretely based on an Example and a comparative example, this invention is not limited only to these Examples.

Example 1 Synthesis of (2-dimethylaminoethyl) trimethylammonium bis (trifluoromethylsulfonyl) imide A 200 ml flask equipped with a stirrer, condenser and thermometer was charged with N, N, N ′, N′-tetramethylethylenediamine. 29.1 g (0.25 mol), 22.6 g (0.25 mol) of dimethyl carbonate, and 30 ml of n-propanol were charged, and the reaction was performed under reflux conditions for 23 hours. During this period, the temperature of the reaction solution gradually increased from 90 to 100 ° C. Thereafter, unreacted dimethyl carbonate and n-propanol were distilled off, and further, a washing operation was performed in diethyl ether to remove impurities, followed by drying to obtain 26.8 g of (2-dimethylaminoethyl) trimethylammonium methyl carbonate salt. Obtained.

Next, 10.0 g of the obtained (2-dimethylaminoethyl) trimethylammonium methyl carbonate was dissolved in 30 g of water, and a 30% aqueous solution of 14.1 g of an equimolar amount of lithium bis (trifluoromethylsulfonyl) imide was stirred. While dripping. After completion of the dropwise addition, the mixture is further stirred and aged for 30 minutes, allowed to stand to separate into two phases, an aqueous phase and an organic phase (target product), the organic phase is washed with water, dried, and liquid (2- 13.3 g of (dimethylaminoethyl) trimethylammonium bis (trifluoromethylsulfonyl) imide was obtained. The product was confirmed by ¹ H-NMR (see FIG. 1).
Example 2 Synthesis of (2-dimethylaminoethyl) ethyldimethylammonium bis (trifluoromethylsulfonyl) imide In the same apparatus as in Example 1, 11.6 g of N, N, N ′, N′-tetramethylethylenediamine ( 0.10 mol) was dissolved in 100 ml of tetrahydrofuran, and 15.6 g (0.10 mol) of iodoethane was added dropwise over 30 minutes. After completion of the addition, the mixture was aged at room temperature for 1 hour, and then reacted at 60 ° C. for 4 hours. The product was filtered and dried to obtain 25.6 g of (2-dimethylaminoethyl) ethyldimethylammonium iodide.

  Next, 10.0 g of the obtained (2-dimethylaminoethyl) ethyldimethylammonium iodide was dissolved in 10 g of water, and a 50% aqueous solution of 10.6 g of an equimolar amount of lithium bis (trifluoromethylsulfonyl) imide was stirred. While dripping. Thereafter, the same operation as in Example 1 was performed to obtain 12.4 g of (2-dimethylaminoethyl) ethyldimethylammonium bis (trifluoromethylsulfonyl) imide.

Example 3 Synthesis of (2-dimethylaminoethyl) trimethylammonium trifluoromethanesulfonate 10.0 g of (2-dimethylaminoethyl) trimethylammonium methylcarbonate obtained by the method of Example 1 was dissolved in 30 g of water and stirred. Then, an equimolar amount of 8.45 g of a sodium trifluoromethanesulfonate 30% aqueous solution was added dropwise with stirring. After completion of the dropwise addition, the mixture is further stirred and aged for 30 minutes, allowed to stand to separate into two phases, an aqueous phase and an organic phase (target product), the organic phase is washed with water, dried, and liquid (2- 12.9 g of dimethylaminoethyl) trimethylammonium trifluoromethanesulfonate was obtained.

Example 4 Synthesis of (3-dimethylaminopropyl) trimethylammonium bis (trifluoromethylsulfonyl) imide 13.0 g (0.10 mol) of N, N, N ′, N′-tetramethyl-1,3-propanediamine 25.0 g of (3-dimethylaminopropyl) trimethylammonium iodide was obtained in the same manner as in Example 2 except that was used.

  Subsequently, salt exchange and treatment were performed in the same manner as in Example 2 except that 10.0 g of the obtained (3-dimethylaminopropyl) ethyldimethylammonium iodide was used, and (3-dimethylaminopropyl) trimethylammonium bis ( 12.7 g of (trifluoromethylsulfonyl) imide was obtained.

Examples 5 to 8 (Evaluation of electrical conductivity)
The electrical conductivity at 25 ° C. of the room temperature molten salt obtained in Examples 1 to 4 was measured. The results are shown in Table 1.

実施例９〜実施例１２
実施例１〜実施例３で得られた常温溶融塩をプロピレンカーボネートに溶解した電解液の、電気伝導率の測定結果を表１にあわせて示す。

Example 9 to Example 12
Table 1 shows the measurement results of the electrical conductivity of the electrolytic solutions obtained by dissolving the room temperature molten salts obtained in Examples 1 to 3 in propylene carbonate.

Comparative Example 1 and Comparative Example 2
Table 1 shows the measurement results of the electrical conductivity of tetraethylammonium tetrafluoroborate (reagent) when propylene carbonate is used as the solvent.

  Tetraethylammonium tetrafluoroborate had low solubility in propylene carbonate, and a salt was precipitated at a concentration of 1.5 mol / l, and the electrical conductivity could not be measured.

1 is a ¹ H-NMR spectrum diagram of (2-dimethylaminoethyl) trimethylammonium bis (trifluoromethylsulfonyl) imide obtained in Example 1. FIG.

Claims (9)

A quaternary ammonium-based room temperature molten salt represented by the following general formula (1).

(Wherein R _{1 to} R ₅ each independently represents an alkyl group having 1 to 4 carbon atoms, n represents an integer of 1 to 6, and A represents an anion.) The quaternary ammonium-based room temperature molten salt according to claim 1, having a melting point of 50 ° C or lower. In the quaternary ammonium-based room temperature molten salt represented by the general formula (1), the anion A is represented by the following general formula (2).
RfSO ₃ ⁻ (2)
(Wherein Rf represents a fluoroalkyl group)
A fluoroalkylsulfonate anion represented by the general formula (3):
(RfSO ₂ ) ₂ N ⁻ (3)
(Wherein Rf has the same definition as above)
A bis (fluoroalkylsulfonyl) imide anion represented by the following general formula (4):
(RfSO ₂ ) ₃ C ⁻ (4)
(Wherein Rf has the same definition as above)
Tris (fluoroalkylsulfonyl) carbanion represented by the following general formula (5)
(FSO ₂ ) ₂ N ⁻ (5)
Bis (fluorosulfonyl) imide anion represented by the following general formula (6)
(RfCO) ₂ N ⁻ (6)
(Wherein Rf has the same definition as above)
Bis (fluoroalkylcarbonyl) imide anion represented by the following general formula (7)
^{_{(RfSO 2) N - (CORf}} ) (7)
(Wherein Rf has the same definition as above)
A (fluoroalkylsulfonyl) (fluoroalkylcarbonyl) imide anion represented by the general formula (8):
RfCOO ⁻ (8)
(Wherein Rf has the same definition as above)
The quaternary ammonium-based room temperature molten salt according to claim 1 or 2, which is one or more anions selected from the group consisting of fluoroalkylcarboxy anions represented by formula (1). In the quaternary ammonium room temperature molten salt represented by the general formula (1), the anion A is trifluoromethanesulfonate, bis (trifluoromethylsulfonyl) imide, bis (pentafluoroethylsulfonyl) imide, tris (trifluoromethyl). One or more selected from the group consisting of (sulfonyl) carbanion, bis (fluorosulfonyl) imide, bis (trifluoromethylcarbonyl) imide, (trifluoromethylsulfonyl) (trifluoromethylcarbonyl) imide, and trifluoroacetic acid The quaternary ammonium-based room temperature molten salt according to claim 1 or 2, wherein The following general formula (9)

_(Wherein, R 1 to R ₄ each independently represents an alkyl group having 1 to 4 carbon atoms, n represents an integer from 1 to 6.)
A quaternary ammonium-based room temperature molten salt according to any one of claims 1 to 4, characterized in that a tertiary diamino compound represented by the formula (I) is reacted with an alkylating agent, and then the product is subjected to anion exchange. Manufacturing method. The method for producing a quaternary ammonium-based room temperature molten salt according to claim 5, wherein the alkylating agent is a dialkyl carbonate or an alkyl halide. 6. The method for producing a quaternary ammonium-based room temperature molten salt according to claim 5, wherein anion exchange is performed with the anion according to claim 3 or 4. An electrolyte salt for an electrochemical device comprising the quaternary ammonium-based ambient temperature molten salt according to any one of claims 1 to 4. An electrolytic solution for an electrochemical device comprising the quaternary ammonium-based room temperature molten salt according to any one of claims 1 to 4.

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