JP2017122058A - Aminosulfonyl imide salt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound available as an electrolyte for a nonaqueous electrolyte that can allow an electricity storage device to be driven under high voltage and allow stable capacity to be maintained for a long time.SOLUTION: An aminosulfonyl imide salt is represented by the general formula in the figure. (In the formula, Rand Rare identical or different and each represent hydrogen or an optionally substituted hydrocarbon group having 1-6 carbon atoms excluding carbon atoms in the substituents; M represents an inorganic or organic cation; and n represents an integer from 1 to 3.)SELECTED DRAWING: None

Description

  The present invention relates to an aminosulfonylimide salt useful as an electrolyte for a non-aqueous electrolyte solution used in an electricity storage device such as a lithium ion secondary battery.

Electric storage devices such as electrolytic capacitors, electric double layer capacitors, lithium ion capacitors, and lithium ion secondary batteries are used in a wide range of fields such as power supplies for mobile phones, personal computers, and automobile power supplies. In these electricity storage devices, various studies have been made on, for example, electrolytes and electrolyte additives so as to increase durability and to be used even under high voltage.
For example, in Patent Documents 1 and 2, fluorosulfonylimide ammonium salt as a production intermediate of an alkali metal salt of fluorosulfonylimide or an onium salt of fluorosulfonylimide, which is used as an electrolyte, leads to a decrease in the performance of an electricity storage device. A manufacturing method that can be manufactured while suppressing generation of impurities is disclosed. However, this method has a problem that an excessive amount of a fluorinating agent is added in order to obtain a di (fluorosulfonyl) imide salt, which makes it difficult to treat the surplus fluorinating agent.

International Publication No. 2012/108284 Pamphlet International Publication No. 2012/117916 Pamphlet

  Under the above circumstances, there is a need for a new electrolyte that can drive an electricity storage device under a high voltage and can improve cycle characteristics that can withstand long-term use.

  The present invention has been made paying attention to the above-mentioned circumstances, and is a non-aqueous electrolysis capable of driving an electric storage device under a high voltage and capable of maintaining a stable capacity over a long period of time. The challenge was to provide compounds that could be used as electrolytes for liquids.

  The present invention that has solved the above problems is an aminosulfonylimide salt represented by the following general formula.

(Wherein R ¹ and R ² are the same or different and each represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent (however, the carbon number of the substituent is not included), M Represents an inorganic or organic cation, and n represents an integer of 1 to 3.)
Here, it is preferable that R ¹ and R ² in the above formula are both hydrogen.

  The present invention also includes an electrolyte containing the aminosulfonylimide salt and a lithium ion secondary battery using the electrolyte. Moreover, the electrode film forming agent using the said aminosulfonyl imide salt is also contained in this invention.

  When the aminosulfonylimide salt of the present invention is used as an electrolyte or an electrode film forming agent, it has a low oxidation potential and decomposes at 4.2 to 5.0 V. Therefore, a film is formed on the positive electrode to decompose the electrolytic solution. Can be suppressed. Therefore, it is considered that the obtained battery can be driven under a high voltage and the cycle characteristics are also improved.

  The present invention relates to an (aminosulfonyl) (fluorosulfonyl) imide salt represented by the above general formula (simply referred to as aminosulfonylimide salt).

In the aminosulfonylimide salt according to the present invention, R ¹ and R ² constituting the amino group are the same or different, and may be hydrogen or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent (however, The carbon number of the substituent is not included). The hydrocarbon group having 1 to 6 carbon atoms may be linear or cyclic, and specifically includes a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, and an iso-butyl group. , Sec-butyl group, tert-butyl group, pentyl group, hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and other alkyl groups having 1 to 6 carbon atoms; vinyl group, propenyl group, isopropenyl group, Carbon number such as allyl group, 1-butenyl group, 2-butenyl group, pentenyl group, hexenyl group, 1-cyclohexenyl group, 2-cyclohexenyl group, 3-cyclohexenyl group, methylcyclohexenyl group, ethylcyclohexenyl group 2-6 alkenyl groups; ethynyl, 1-propynyl, 2-propynyl, 3-butynyl, pentynyl, hex An alkynyl group having 2 to 6 carbon atoms such as a cycloalkenyl group; a phenyl group and the like.

Examples of the substituent that R ¹ and R ² may have include, for example, an amino group, an imino group, an amide group, a group having an ether bond, a group having a thioether bond, an ester group, a hydroxyl group, an alkyl group, and an alkoxy group. Group, carboxyl group, carbamoyl group, cyano group, disulfide group, nitro group, nitroso group, sulfonyl group and the like.

R ¹ and R ² are preferably both hydrogen, and aminosulfonylimide salts in which R ¹ and R ² are both hydrogen are easy to produce. n represents an integer of 1 to 3.

M is an inorganic or organic cation. Examples of the inorganic cation include monovalent inorganic cations such as Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ and Pb ⁺ ; Mg ²⁺ , Ca ²⁺ , Zn ²⁺ , Pd ²⁺ , Sn ²⁺ , And divalent inorganic cations such as Hg ²⁺ , Rh ²⁺ , Cu ²⁺ , Be ²⁺ , Sr ²⁺ , and Ba ²⁺ ; and trivalent inorganic cations such as Ga ³⁺ . Among these, an alkali metal cation and an alkaline earth metal cation are preferable, and Li ⁺ , Na ⁺ , Mg ²⁺ and Ca ²⁺ are more preferable because they have a small ionic radius and can be easily used for batteries and the like, and Li ⁺ is particularly preferable.

The organic cation has a general formula: L ⁺ -R _s (wherein L represents C, Si, N, P, S, or O, R is the same or different organic group, and they are bonded to each other). S represents the number of R bonded to L, and is 3 or 4. Note that s is a value determined by the valence of the element L and the number of double bonds directly bonded to L). Preferred are onium cations.

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

  Specific examples of the onium cation include those represented by the following general formula.

(Wherein, R is as defined above) is preferred. These onium cations may be used alone or in combination of two or more. Among these, the following onium cations are preferable.

  (1) The following general formula:

One of nine heterocyclic onium cations represented by

(2) The following general formula:

One of five types of unsaturated onium cations represented by

(3) The following general formula:

1 type of 10 types of saturated ring onium cations represented by these.

In said general formula, R < ⁶ > -R < ¹⁷ > is the same or different, is an organic group, and may couple | bond together.

(4) R is hydrogen, or, chain onium cation is an alkyl group of C ₁ -C _8. Among them, those in which L is N in the general formula: L ⁺ -R _s are preferable. For example, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, tetraheptylammonium, tetrahexylammonium, tetraoctylammonium, triethylmethylammonium, methoxyethyldiethylmethylammonium, trimethylphenylammonium, benzyltrimethylammonium, benzyltributylammonium Quaternary ammoniums such as benzyltriethylammonium, dimethyldistearylammonium, diallyldimethylammonium, 2-methoxyethoxymethyltrimethylammonium, tetrakis (pentafluoroethyl) ammonium, trimethylammonium, triethylammonium, tributylammonium, Tertiary ammonium such as ruammonium, dimethylethylammonium and dibutylmethylammonium, secondary ammoniums such as dimethylammonium, diethylammonium and dibutylammonium, methylammonium, ethylammonium, butylammonium, hexylammonium and octylammonium Examples include primary ammoniums, N-methoxytrimethylammonium, N-ethoxytrimethylammonium, N-propoxytrimethylammonium, and ammonium compounds such as NH ₄ . Among these exemplified chain onium cations, preferred chain onium cations are ammonium, trimethylammonium, triethylammonium, tributylammonium, triethylmethylammonium, tetraethylammonium and diethylmethyl (2-methoxyethyl) ammonium.

  Among the onium cations of the above (1) to (4), preferred are the following general formulas:

(Wherein R ^{6 to} R ¹⁷ are the same as above), and the chain onium cation of (4) above. The organic group of R ^{6 to} R ¹⁷ is preferably a linear, branched, or cyclic saturated or unsaturated hydrocarbon group having 1 to 18 carbon atoms, a fluorine group, or the like, more preferably 1 to 8 carbon atoms. A saturated or unsaturated hydrocarbon group or a fluorocarbon group. These organic groups are hydrogen atom, fluorine atom, amino group, imino group, amide group, ether group, ester group, hydroxyl group, carboxyl group, carbamoyl group, cyano group, sulfone group, sulfide group, nitrogen atom, oxygen An atom, a sulfur atom, etc. may be included. More preferably, it has any one or more of a hydrogen atom, a fluorine atom, a cyano group and a sulfone group. In addition, when two or more organic groups are bonded, the bond may be formed between the main skeleton of the organic group, or between the main skeleton of the organic group and the above-described substituent, or It may be formed between the above substituents.

The onium cation is made from a salt composed of the onium cation and an anion. Examples of the anion of the salt containing the onium cation include fluorine, chlorine, bromine, iodine, hydroxide ion (OH ⁻ ), carbonate ion and bicarbonate ion.

Next, an example of a method for producing an aminosulfonylimide salt will be described. The starting material is preferably di (chlorosulfonyl) imide. First, ammonium chloride is reacted with di (chlorosulfonyl) imide in a proton form to obtain a di (chlorosulfonyl) imide ammonium salt (cation exchange reaction). Then, here, the addition of acidic NH ₄ F (HF) is a fluorinating agent, reacted both (fluorination reaction). At this time, the reaction ratio of di (chlorosulfonyl) imidoammonium salt to NH ₄ F (HF) is di (chlorosulfonyl) imidoammonium salt: NH ₄ F (HF) = 1: 0.4 to 0.6 (equivalent Ratio). By using a small amount of fluorinating agent, an ammonium salt of (chlorosulfonyl) (fluorosulfonyl) imide can be obtained. By supplying a nitrogen source to the ammonium salt of (chlorosulfonyl) (fluorosulfonyl) imide, (aminosulfonyl) (fluorosulfonyl) imide ammonium salt is obtained (amination reaction). The obtained (aminosulfonyl) (fluorosulfonyl) imidoammonium salt solution was filtered to remove solids, and then the solvent was distilled off to obtain (aminosulfonyl) (fluorosulfonyl) imidoammonium salt (solid). Can be obtained.

As di (chlorosulfonyl) imide, a commercially available product or a synthesized product may be used. In the case of synthesis, sulfuric acid anhydride is reacted with cyanogen chloride to obtain chlorosulfonyl isocyanate, and chlorosulfonic acid is reacted with this to obtain di (chlorosulfonyl) imide. As the fluorinating agent, in addition to NH ₄ F (HF), NH ₄ F, NH ₄ F (HF) ₂ , NH ₄ F (HF) ₃ , NH ₄ F (HF) ₄ , HF, MF _x (M Can also be used, such as 1 to 3 metal elements, and x is an integer of 1 to 3). The fluorinating agent is preferably 0.1 to 1.0 equivalent relative to 1 equivalent of di (chlorosulfonyl) imidoammonium salt.

As a nitrogen source, in addition to ammonia gas and aqueous ammonia, primary amines such as ethylamine, propylamine, isopropylamine, butylamine, isobutylamine, tert-butylamine, cyclohexylamine, aniline, dimethylamine, diethylamine, dipropylamine, Secondary amines such as diisopropylamine, dibutylamine, diisobutylamine, di-tert-butylamine, dicyclohexylamine, piperidine, pyrrolidine and the like can be mentioned. These nitrogen sources are preferably excessive with respect to the ammonium salt of (chlorosulfonyl) (fluorosulfonyl) imide.
When ammonia gas is used as the nitrogen source, the amination reaction proceeds only by bubbling, which is convenient and preferable. The aminosulfonylimide salt produced at this time is a compound in which R ¹ and R ² are both hydrogen.

  Although it does not specifically limit as reaction conditions, It is preferable to perform all cation exchange reaction, fluorination reaction, and amination reaction at -20-100 degreeC. The fluorination reaction is preferably carried out at about 40 to 100 ° C., since the reaction proceeds faster when heated. The pressure may be normal pressure, increased pressure, or reduced pressure. The cation exchange reaction and the fluorination reaction are preferably performed in a dry air atmosphere or an inert gas atmosphere.

  The above reaction is preferably performed in the presence of a solvent. Examples of the solvent include ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 4-methyl. -1,3-dioxolane, methyl formate, methyl acetate, methyl propionate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, sulfolane, 3-methyl sulfolane, dimethyl sulfoxide, N, N-dimethylformamide, N-methyloxazolidinone , Acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, benzonitrile, ethyl acetate, isopropyl acetate, butyl acetate, nito Aprotic solvents such as rhomethane and nitrobenzene are preferably used. Of the above exemplified solvents, acetonitrile is preferred.

  Moreover, the di (chlorosulfonyl) imide in the proton form, which is a starting material, can be replaced not only with an ammonium salt but also with the above-described organic cation. Furthermore, the obtained ammonium salt of (aminosulfonyl) (fluorosulfonyl) imide, which is the target product, can be exchanged with an alkali metal by reacting with an alkali metal compound. As a cation exchange reaction to an alkali metal, a method of reacting a salt containing a desired alkali metal ion with an ammonium salt of (aminosulfonyl) (fluorosulfonyl) imide, an ammonium salt of (aminosulfonyl) (fluorosulfonyl) imide And the like.

Examples of compounds (salts) that can be used for cation exchange with alkali metals include hydroxides such as LiOH, NaOH, KOH, RbOH, and CsOH, Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , and Rb ₂ CO _3. , Carbonates such as Cs ₂ CO ₃ , hydrocarbons such as LiHCO ₃ , NaHCO ₃ , KHCO ₃ , RbHCO ₃ , CsHCO ₃ , chlorides such as LiCl, NaCl, KCl, RbCl, CsCl, LiF, NaF, KF, Fluorides such as RbF and CsF, alkoxide compounds such as CH ₃ OLi and Et ₂ OLi, and alkyllithium compounds such as EtLi, BuLi and t-BuLi (Et represents an ethyl group and Bu represents a butyl group) Is mentioned.

  After the exchange reaction with an alkali metal cation, purification may be performed to increase the purity of the product. In the present invention, the target product can be easily purified by a liquid separation extraction method using water, an organic solvent, and a mixed solvent thereof. Examples of the organic solvent that can be used at this time include ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3- Dioxane, 4-methyl-1,3-dioxolane, methyl formate, methyl acetate, methyl propionate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, acetonitrile, sulfolane, 3-methyl sulfolane, dimethyl sulfoxide, N, N- Dimethylformamide, N-methyloxazolidinone, butyronitrile, isobutyronitrile, valeronitrile, benzonitrile, ethyl acetate, isopropyl acetate, butyl acetate, Examples include aprotic solvents such as nitromethane and nitrobenzene. Of course, conventionally known methods such as washing with the above solvent, reprecipitation method, liquid separation extraction method, recrystallization method, crystallization method, and purification method by chromatography may be employed.

  The aminosulfonylimide salt of the present invention is useful as an electrolyte that is dissolved in an electrolytic solution such as a lithium ion secondary battery, a capacitor, or an ionic liquid. The concentration in the electrolytic solution is preferably 0.1 mol / L or more and saturated concentration or less. More preferably, they are 0.1 mol / L or more and 3 mol / L or less, More preferably, they are 0.3 mol / L or more and 2 mol / L or less, Especially preferably, they are 0.5 mol / L or more and 1.5 mol / L or less.

When the aminosulfonylimide salt of the present invention is used as an electrolyte, it may be used in combination with another electrolyte. Other electrolytes include, for example, lithium di (fluorosulfonyl) imide salts and lithium N- (fluorosulfonyl) -N- (fluoroalkylsulfonyl) imide salts described in numerous applications by the present applicant, Examples include LiPF ₆ , LiPF ₃ (C ₂ F ₅ ) ₃ , LiBF ₄ , LiBF (CF ₃ ) _{3 and the} like. A battery using the aminosulfonylimide salt of the present invention as an electrolyte can be used under a high voltage of 4.2 V or higher.

  The electrolyte containing the aminosulfonylimide salt of the present invention includes a primary battery, a battery having a charging / discharging mechanism such as a lithium (ion) secondary battery and a fuel cell, an electrolytic capacitor, an electric double layer capacitor, a solar cell and an electrochromic display element. It is suitably used as an ion conductor material constituting an electrochemical device such as

  The aminosulfonylimide salt of the present invention can also be used as an additive for an electrolytic solution as an electrode film forming agent. Since the aminosulfonylimide salt is decomposed at a low oxidation potential, a film can be formed on the surface of the positive electrode to suppress decomposition of the electrolytic solution. Therefore, it is considered that the obtained battery can be driven under a high voltage and the cycle characteristics are also improved.

  When the aminosulfonylimide salt of the present invention is used as an electrode film forming agent, the concentration in the electrolytic solution is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and 0.1 to 2% by mass. % Is more preferable.

  The aminosulfonylimide salt of the present invention can also be used as a synthetic intermediate of a compound, a polymer modifier, an antistatic agent and the like.

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

Example 1 Synthesis of (aminosulfonyl) (fluorosulfonyl) imidoammonium salt In a reaction vessel made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), 12.6 g (235. 9 mmol) and 75 mL of acetonitrile were added, 50 g (233.6 mmol) of di (chlorosulfonyl) imide (proton) was added, and the mixture was stirred at room temperature (25 ° C.) for 1 hour.

Next, after adding 6.66 g (116.8 mmol) of acidic ammonium fluoride (NH ₄ F (HF)) to the mixed solution, a tetrafluoroethylene cooler and a glass connecting tube were attached to the reaction vessel, and the reaction was performed. The temperature of the solution was raised to 60 ° C., and stirring was continued at this temperature for 12 hours.

Next, after the reaction vessel was cooled to room temperature (25 ° C.), bubbling of ammonia gas into the reaction solution was started. Bubbling of ammonia gas continued for 4 hours. The supply amount (stoichiometric amount) of ammonia gas per unit time with respect to di (chlorosulfonyl) imide as a starting material was 8.8 equivalent / hour. The total amount of ammonia gas used was 35 equivalents relative to the starting di (chlorosulfonyl) imide. After completion of the reaction, the reaction solution was filtered to remove solids, and then the solvent was distilled off to obtain (aminosulfonyl) (fluorosulfonyl) imidoammonium salt (210.2 mmol, conversion 90%). The obtained sample was measured by ¹⁹ F-NMR (solvent: deuterated acetonitrile, internal standard substance: benzenesulfonyl fluoride).
¹⁹ F-NMR: δ 54.8

The above reaction was carried out according to the following scheme.

Example 2 Synthesis of (aminosulfonyl) (fluorosulfonyl) imidoammonium salt A tetrafluoroethylene cooler and a glass connecting tube were attached to a reaction vessel made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA). Under a dry air atmosphere, 6.66 g (116.8 mmol) of acidic ammonium fluoride (NH ₄ F (HF)) and 75 mL of acetonitrile were added, the temperature of the reaction solution was raised to 60 ° C., and di (chlorosulfonyl) imide ( (Proton) (50 g, 233.6 mmol) was added and stirred for 24 hours.

Next, after the reaction vessel was cooled to room temperature (25 ° C.), bubbling of ammonia gas into the reaction solution was started. Bubbling of ammonia gas continued for 4 hours. The supply amount (stoichiometric amount) of ammonia gas per unit time with respect to di (chlorosulfonyl) imide as a starting material was 8.8 equivalent / hour. The total amount of ammonia gas used was 35 equivalents relative to the starting di (chlorosulfonyl) imide. After completion of the reaction, the reaction solution was filtered to remove solids, and then the solvent was distilled off to obtain (aminosulfonyl) (fluorosulfonyl) imidoammonium salt (198.5 mmol, conversion rate 85%). The obtained sample was measured by ¹⁹ F-NMR (solvent: deuterated acetonitrile, internal standard substance: benzenesulfonyl fluoride).
¹⁹ F-NMR: δ 54.8
The above reaction was carried out according to the following scheme.

LSV measurement In an acetonitrile solution of 1 mol / L di (fluorosulfonyl) imide ammonium salt (NH ₄ FSI), (aminosulfonyl) (fluorosulfonyl) imide ammonium salt (NH ₄ NFSI) is 0.1% by mass. In addition, LSV (linear sweep voltammetry) measurement was performed on the obtained electrolytic solution. Glassy carbon was used for the working electrode, platinum was used for the counter electrode, and lithium foil was used for the reference electrode. The sweep rate was 5 mV / s, and the measurement was performed from the natural potential to 10 V. The upper limit value of the current was 100 μA.
As a comparative example, LSV measurement was also performed on a 1 mol / L NH ₄ FSI acetonitrile solution.

In the comparative example, rising of the current value was confirmed between 5.5 and 6.0V. On the other hand, in the system to which NH ₄ NFSI was added, a rise in current value was confirmed between 4.2 and 5.0V. Since the oxidation potential of the NFSI anion is lower than that of the FSI anion, the battery decomposes at a lower voltage before the electrolyte such as FSI to form a film on the surface of the positive electrode. It is expected to suppress the decomposition and improve the battery performance.

Example 3 Synthesis of (aminosulfonyl) (fluorosulfonyl) imide potassium salt 10 g (51.2 mmol) of (aminosulfonyl) (fluorosulfonyl) imidoammonium salt and 100 mL of butyl acetate were added to a separating funnel to obtain a solution. After adding 30 mL of a mass% aqueous potassium hydroxide solution and stirring well, a liquid separation operation was performed. After removing the aqueous layer, 30 mL of a 10% by mass aqueous potassium hydroxide solution was added again and stirred well to carry out a liquid separation operation. After removing the aqueous layer, the solvent was distilled off to obtain (aminosulfonyl) (fluorosulfonyl) imide potassium salt (43.5 mmol, conversion: 85%). The obtained sample was measured by ¹⁹ F-NMR (solvent: deuterated acetonitrile, internal standard substance: benzenesulfonyl fluoride).
¹⁹ F-NMR: δ 54.8

Since the aminosulfonylimide salt of the present invention is decomposed at a low oxidation potential, when it is contained in the battery electrolyte, it can form a film on the surface of the positive electrode and suppress decomposition of the electrolyte. Therefore, it is considered that the obtained battery can be driven under a high voltage and the cycle characteristics are also improved.
The aminosulfonylimide salt of the present invention can also be used as a synthetic intermediate of a compound, a polymer modifier, an antistatic agent and the like.

Claims (5)

An aminosulfonylimide salt represented by the following general formula:
(Wherein R ¹ and R ² are the same or different and each represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent (however, the carbon number of the substituent is not included), M Represents an inorganic or organic cation, and n represents an integer of 1 to 3.) The aminosulfonylimide salt according to claim 1, wherein R ¹ and R ² in the above formula are both hydrogen.   An electrolyte comprising the aminosulfonylimide salt according to claim 1 or 2.   A lithium ion secondary battery using the electrolyte according to claim 3.   An electrode film-forming agent using the aminosulfonylimide salt according to claim 1 or 2.