CN110407724A - A kind of double ion is to ionic liquid and preparation method thereof - Google Patents

Abstract

The invention relates to ionic liquid technology, and aims to provide a dual-ion-pair ionic liquid and a preparation method thereof. Including: taking trisubstituted amine compound and halogenated sulfonate compound, dissolving in water-ethanol mixed solvent and reflux reaction; rotary evaporation to remove water and ethanol; then adding water and extracting with dichloromethane three times, retaining the water phase; rotating After evaporating most of the water, add the salt compound; after stirring, let it stand still, take the lower layer solution and dry it under vacuum to obtain a purified double-ion counter-ionic liquid. The product of the invention can be mixed with carbonate or ether electrolytes in various proportions to prepare new electrolytes, thereby improving the thermal stability of the electrolytes and the safety of lithium-ion batteries. When used as an electrolyte, the amount of corresponding metal ions added can be reduced, or even no corresponding metal ions need to be added. The invention has the advantages of simple operation, few steps, high yield, no toxic by-products, and is suitable for large-scale production.

Description

A kind of dual ion pair ionic liquid and preparation method thereof

technical field

The invention relates to ionic liquid technology, in particular to a dual-ion pair ionic liquid and a preparation method thereof.

Background technique

Ionic liquid is an ionic compound composed of anions and cations, which is a flowable liquid at room temperature, so it is also called room temperature ionic liquid. Ionic liquids generally have the advantages of high boiling point and thermal decomposition temperature, high ionic conductivity and wide electrochemical window. The above advantages enable ionic liquids to be used in solving the safety problems of lithium-ion batteries.

Chinese invention patent CN109627227A reports a method for preparing a piperidine-type ionic liquid. The method is carried out at normal temperature, and has high yield, economy and simple operation. The synthesized ionic liquid can be applied to the electrolyte components of lithium-ion batteries, showing better non-combustibility and chemical stability as well as low electrochemical impedance. However, the reaction is carried out in an organic solution, which is not environmentally friendly enough. Chinese invention patent CN109575023A reports a matrine long-chain fatty acid ionic liquid and its preparation method. The ionic liquid has good solubility, absorption and stability, but the preparation method has harsh reaction conditions and needs to be reacted in an inert gas atmosphere. , the post-processing process requires a vacuum environment.

Therefore, inventing new ionic liquids is of great significance to the in-depth study and application of ionic liquids.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a dual-ion-pair ionic liquid and a preparation method thereof.

For solving technical problem, solution of the present invention is:

Provide a kind of double ion pair ionic liquid, this double ion pair ionic liquid has following structure:

Wherein, R ₁ is an oxyethylene chain CH ₃ (OCH ₂ CH ₂ ) _n - with a methyl terminal, n=2-6; R ₂ is an alkane chain -(CH ₂ CH ₂ ) _n -, n=2-6; R ^- is a negative monovalent anion, which is any one of perchlorate, bis(trifluoromethylsulfonyl)imide, bis(fluorosulfonyl)imide, tetrafluoroborate or dioxalate borate; M+ It is a positive monovalent metal ion, which is sodium ion (Na ⁺ ), lithium ion (Li ⁺ ) or potassium ion (K ⁺ ).

The present invention further provides a method for preparing the aforementioned dual ion-pair ionic liquid, comprising the following steps:

(1) Take the trisubstituted amine compound M1 and the halogenated sulfonate compound M2, and dissolve them in a mixed solvent of water and ethanol; reflux at 100°C for 72 hours;

(2) After the reaction finishes, rotary evaporation removes water and ethanol in the reaction solution; then add water, then extract three times with dichloromethane, retain the water phase;

(3) The water phase was removed by rotary evaporation to remove 80% of the water, and then the salt compound M3 was added; after stirring for 6 hours, it was left to stand, and after the solution was layered, the solution in the lower layer was taken; it was dried under vacuum for 24 hours to obtain Purified dual-ion pair ionic liquid;

The dosage relation of each reagent: the molar ratio of compound M1, M2, M3 is M1: M2: M3=1: 1: 1; In the mixed solvent of water and ethanol, the volume ratio of water and ethanol is 5: 1; With 1 mole Compound M1 is used as the metering basis, the volume of water in the mixed solvent of water and ethanol is 880 milliliters, the volume of water added before dichloromethane extraction is 750 milliliters, and the volume of dichloromethane used for each extraction is 750 milliliters.

In the present invention, the chemical structural formula of the trisubstituted amine compound M1 is:

Wherein R ₁ is an oxyethylene chain CH ₃ (OCH ₂ CH ₂ ) _n - with a terminal methyl group, n=2-6.

In the present invention, the trisubstituted amine compound M1 is tris(3,6-dioxaheptyl)amine (that is, preferably n=2), tris(3,6,9,12-tetraoxatridecane base) amine (ie n=4), or tris(3,6,9,12,15,18-hexaoxanonadecyl)amine (ie n=6).

In the present invention, the chemical structural formula of the halogenated sulfonate compound M2 is:

XR ₂ -SO ₃ ^{-M +}

Where X is a chlorine atom (Cl), bromine atom (Br) or iodine atom (I), R ₂ is an alkane chain -(CH ₂ CH ₂ ) _n -, n=2~6; M ⁺ is a positive monovalent metal ion , is a sodium ion (Na ⁺ ), lithium ion (Li ⁺ ) or potassium ion (K ⁺ ).

In the present invention, the halogenated sulfonate compound M2 is sodium 2-bromoethylsulfonate, lithium 2-bromoethylsulfonate or potassium 2-bromoethylsulfonate (that is, preferably n=2 and X is bromine atom Br; particularly preferably lithium 2-bromoethanesulfonate).

In the present invention, the chemical structural formula of the salt compound M3 is:

M ⁺ R ^-

Among them, M ⁺ is a positive monovalent metal ion, which is sodium ion (Na ⁺ ), lithium ion (Li ⁺ ) or potassium ion (K ⁺ ); R ^- is a negative monovalent anion, which is perchlorate, bis(trifluoro Methylsulfonyl)imide, bis(fluorosulfonyl)imide, tetrafluoroborate or dioxalatoborate.

In the present invention, the salt compound M3 is sodium perchlorate, sodium bis(trifluoromethylsulfonyl)imide, sodium bis(fluorosulfonyl)imide, sodium tetrafluoroborate, sodium dioxalate borate, high Lithium chlorate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, lithium dioxalate borate, potassium perchlorate, bis(trifluoromethylsulfonyl)imide Any one of potassium amide, potassium bis(fluorosulfonyl)imide, potassium tetrafluoroborate or potassium dioxalate borate. Among them, lithium bis(trifluoromethylsulfonyl)imide is particularly preferable.

Description of invention principle:

In the present invention, a quaternary ammonium salt is obtained through a quaternization reaction between the trisubstituted amine compound M1 and the halogenated sulfonate compound M2, and the halogen anion is replaced by a larger anion through subsequent reaction with the salt compound M3, such as high Chlorate, bis(trifluoromethylsulfonyl)imide, bis(fluorosulfonyl)imide, tetrafluoroborate, or dioxalate borate; due to the large volume of anion and cation, the resulting product can In liquid state, the double-ion-pair ionic liquid is obtained.

Compared with prior art, the beneficial effect of the present invention is:

1. The product of the present invention can be mixed with carbonate or ether electrolytes in various proportions to prepare new electrolytes, improving the thermal stability of the electrolytes and the safety of lithium-ion batteries.

2. The dual-ion pair ionic liquid of the present invention itself contains sodium ions, lithium ions or potassium ions. There is no similar report at present. When used as an electrolyte, the amount of the corresponding metal ions added can be reduced, or even the corresponding metal ions do not need to be added. ion.

3. The invention has simple operation, few steps, high yield, no toxic by-products, and is suitable for large-scale production.

Description of drawings

Fig. 1 is the NMR spectrum of the dual ion-pair ionic liquid obtained in Example 8.

Fig. 2 is a relationship curve between the discharge specific capacity and the number of charge and discharge cycles of the lithium/lithium iron phosphate battery in application examples 1 and 2.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The following examples can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way.

Example 1

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of sodium 2-bromoethylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation of the water phase product removes dichloromethane and 80% water, then adds 1 mole of bis(trifluoromethylsulfonyl)imide lithium, stirs for 6 hours, filters after standing, and removes water by rotary evaporation, and then removes water in a vacuum oven. Dry in medium for 24 hours to obtain the double ion-pair ionic liquid.

Example 2

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of sodium 2-bromoethylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation water phase product removes methylene chloride and 80% water, then adds 1 mole of lithium perchlorate, stirs for 6 hours, filters after standing, removes water by rotary evaporation, and dries in a vacuum oven for 24 hours to obtain bis Ionic versus ionic liquid.

Example 3

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of lithium 2-bromohexylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol. Stir and reflux in an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. The water phase product was rotary evaporated to remove dichloromethane and 80% of water, then 1 mole of lithium tetrafluoroborate was added, stirred for 6 hours, filtered after standing, and the water was removed by rotary evaporation, and dried in a vacuum oven for 24 hours to obtain bis Ionic versus ionic liquid.

Example 4

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of sodium 2-bromoethylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation of the aqueous phase product to remove dichloromethane and 80% of water, then add 1 mole of sodium tetrafluoroborate, stir for 6 hours, filter after standing, remove water by rotary evaporation, and dry in a vacuum oven for 24 hours to obtain bis Ionic versus ionic liquid.

Example 5

Dissolve 0.5 moles of tris(3,6-dioxaheptyl)amine and 0.5 moles of sodium 2-bromoethylsulfonate in a mixed solvent made of 440 milliliters of deionized water and 88 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 375 ml of water were added, followed by three extractions with 375 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation of the aqueous phase product to remove dichloromethane and 80% of water, then add 0.5 mole potassium bis(fluorosulfonyl)imide, stir for 6 hours, filter after standing, remove water by rotary evaporation, and dry in a vacuum oven for 24 hours, the double ion-pair ionic liquid is obtained.

Example 6

Dissolve 2 moles of tris(3,6-dioxaheptyl)amine and 2 moles of sodium bromohexylsulfonate in a mixed solvent made of 1760 milliliters of deionized water and 352 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. Add 1500 ml of water, then extract three times with 1500 ml of dichloromethane each time, leaving the aqueous phase product. Rotary evaporation of the water phase product to remove dichloromethane and 80% of water, then add 2 moles of sodium bis(fluorosulfonyl)imide, stir for 6 hours, filter after standing, remove water by rotary evaporation, dry in a vacuum oven for 24 hours, the double ion-pair ionic liquid is obtained.

Example 7

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of potassium 2-bromobutylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation of the water phase product to remove dichloromethane and 80% of water, then add 1 mole of potassium dioxalate borate, stir for 6 hours, filter after standing, remove water by rotary evaporation, and dry in a vacuum oven for 24 hours to obtain bis Ionic versus ionic liquid.

Example 8

Dissolve 0.25 moles of tris(3,6-dioxaheptyl)amine and 0.25 moles of lithium 2-bromoethylsulfonate in a mixed solvent made of 220 milliliters of deionized water and 44 milliliters of absolute ethanol, at 100 °C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 187.5 ml of water were added, followed by three extractions with 187.5 ml of dichloromethane each time, leaving the aqueous phase product. Rotary evaporation water phase product removes dichloromethane and 80% water, then adds 0.25 moles of lithium perchlorate, stirs for 6 hours, filters after standing, rotary evaporation removes water, and dries in a vacuum oven for 24 hours to obtain bis Ionic versus ionic liquid. The NMR spectrum of the obtained dual ion pair ionic liquid is shown in FIG. 1 .

Example 9

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of potassium 2-bromoethylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation of the water phase product removes dichloromethane and 80% of water, then adds 1 mole of potassium bis(trifluoromethylsulfonyl)imide, stirs for 6 hours, filters after standing, removes water by rotary evaporation, and removes water in a vacuum oven Dry in medium for 24 hours to obtain the double ion-pair ionic liquid.

Example 10

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of sodium 2-bromoethylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation of the aqueous phase product removes dichloromethane and 80% of water, then adds 1 mole of bis(trifluoromethylsulfonyl)imide sodium, stirs for 6 hours, filters after standing, removes water by rotary evaporation, and removes water in a vacuum oven Dry in medium for 24 hours to obtain the double ion-pair ionic liquid.

Example 11

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of sodium 2-chloroethylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100 ° C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation of the aqueous phase product removes dichloromethane and 80% of water, then adds 1 mole of bis(trifluoromethylsulfonyl)imide sodium, stirs for 6 hours, filters after standing, removes water by rotary evaporation, and removes water in a vacuum oven Dry in medium for 24 hours to obtain the double ion-pair ionic liquid.

Example 12

Dissolve 0.25 moles of tris(3,6-dioxaheptyl)amine and 0.25 moles of lithium 2-iodoethylsulfonate in a mixed solvent made of 220 milliliters of deionized water and 44 milliliters of absolute ethanol, at 100 ° C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 187.5 ml of water were added, followed by three extractions with 187.5 ml of dichloromethane each time, leaving the aqueous phase product. Rotary evaporation of the aqueous phase product removes dichloromethane and 80% of water, then adds 0.25 mole of bis(trifluoromethylsulfonyl)imide lithium, stirs for 6 hours, filters after standing, removes water by rotary evaporation, and removes water in a vacuum oven Dry in medium for 24 hours to obtain the double ion-pair ionic liquid.

Example 13

A mixture prepared by dissolving 0.25 mol of tris(3,6,9,12-tetraoxatridecyl)amine and 0.25 mol of lithium 2-iodoethylsulfonate in 220 ml of deionized water and 44 ml of absolute ethanol solvent, stirred and refluxed for 72 hours in an oil bath at 100°C. Then the water and absolute ethanol were removed by rotary evaporation. 187.5 ml of water were added, followed by three extractions with 187.5 ml of dichloromethane each time, leaving the aqueous phase product. Rotary evaporation of the aqueous phase product removes dichloromethane and 80% of water, then adds 0.25 mole of bis(trifluoromethylsulfonyl)imide lithium, stirs for 6 hours, filters after standing, removes water by rotary evaporation, and removes water in a vacuum oven Dry in medium for 24 hours to obtain the double ion-pair ionic liquid.

Example 14

Dissolve 1 mole of tris(3,6,9,12,15,18-hexaoxanonadecyl)amine and 1 mole of lithium 2-bromohexylsulfonate in 880 ml of deionized water and 176 ml of absolute ethanol The resulting mixed solvent was stirred and refluxed for 72 hours in an oil bath at 100°C. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. Rotary evaporation water phase product removes methylene chloride and 80% water, then adds 1 mole of lithium perchlorate, stirs for 6 hours, filters after standing, removes water by rotary evaporation, and dries in a vacuum oven for 24 hours to obtain bis Ionic versus ionic liquid.

Example 15

Dissolve 1 mole of tris(3,6-dioxaheptyl)amine and 1 mole of lithium 2-bromobutylsulfonate in a mixed solvent made of 880 milliliters of deionized water and 176 milliliters of absolute ethanol, at 100°C Stir and reflux under an oil bath for 72 hours. Then the water and absolute ethanol were removed by rotary evaporation. 750 ml of water were added, followed by three extractions with 750 ml of dichloromethane each time, leaving the aqueous product. The water phase product was rotary evaporated to remove dichloromethane and 80% of water, then 1 mole of lithium borate dioxalate was added, stirred for 6 hours, filtered after standing, and the water was removed by rotary evaporation, and dried in a vacuum oven for 24 hours to obtain bis Ionic versus ionic liquid.

Product application examples:

Application example 1

Mix 9.0 milliliters of the dual ion-pair ionic liquid prepared in Example 8, 0.5 milliliters of ethylene carbonate and 0.5 milliliters of propylene carbonate in an anhydrous and oxygen-free glove box to prepare an electrolyte. The electrolyte solution was used to assemble a lithium/lithium iron phosphate battery, and the resulting battery was subjected to a charge-discharge test at 0.5C.

In the electrolytic solution obtained in this embodiment, the volume fraction of propylene carbonate is 5%, the volume fraction of ethylene carbonate is 5%, and the volume fraction of the double ion-pair ionic liquid is 90%.

Application example 2

Mix 8.5 milliliters of the dual ion-pair ionic liquid prepared in Example 8, 0.5 milliliters of ethylene carbonate and 1.0 milliliters of propylene carbonate in an anhydrous and oxygen-free glove box to prepare an electrolyte. The electrolyte solution was used to assemble a lithium/lithium iron phosphate battery, and the resulting battery was subjected to a charge-discharge test at 0.5C.

In the electrolytic solution obtained in this embodiment, the volume fraction of propylene carbonate is 10%, the volume fraction of ethylene carbonate is 5%, and the volume fraction of the double ion-pair ionic liquid is 85%.

The relationship curves between the specific discharge capacity and the number of charge and discharge cycles of the lithium/lithium iron phosphate batteries in application examples 1 and 2 are shown in Fig. 2 .

Finally, it should be noted that what is listed above are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many modifications are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (8)

1. a kind of double ion is to ionic liquid, which is characterized in that the double ion has the following structure ionic liquid:

Wherein, R₁For the ethylene oxide chain CH of terminal methyl₃(OCH₂CH₂)_n, n=2~6；R₂For alkane chain-(CH₂CH₂)_n, n=2 ~6；R^-Be negative univalent anion, is perchlorate, two (trimethyl fluoride sulfonyl) imines, bis- (fluorine sulphonyl) imines, tetrafluoro boric acid Any one in root or dioxalic acid borate；M+ is positive monovalent metallic ion, is sodium ion, lithium ion or potassium ion.

2. double ion described in claims 1 is to the preparation method of ionic liquid, which comprises the following steps:

(1) three substitutional amine-group compound M1 and halogenosulfonic acid salt compound M2 are taken, water-ethanol in the mixed solvent is dissolved in；100 Back flow reaction 72 hours under the conditions of DEG C；

(2) after reaction, rotary evaporation removes the water and ethyl alcohol in reaction solution；Then water is added, then is extracted with methylene chloride It takes three times, retains water phase；

(3) water phase after removing 80% water, is added into salt compounds M3 by rotary evaporation；Stirring is stood after 6 hours, After solution layering, lower layer's solution is taken；It is dried under vacuum 24 hours, the double ion of purifying is made to ionic liquid；

The dosage relation of each reagent: the molar ratio of compound M1, M2, M3 are M1: M2: M3=1: 1: 1；In water-ethanol mixed solvent In, the volume ratio of water and ethyl alcohol is 5: 1；Using 1 mole of compound M1 as mete-wand, the volume of water-ethanol in the mixed solvent water It is 880 milliliters, the volume that water is added before methylene chloride extraction is 750 milliliters, and methylene chloride volume used is 750 when extraction every time Milliliter.

3. method according to claim 2, which is characterized in that the chemical structural formula of the three substitutional amine-group compounds M1 Are as follows:

Wherein R₁For the ethylene oxide chain CH of terminal methyl₃(OCH₂CH₂)_n, n=2~6.

4. method according to claim 2, which is characterized in that the three substitutional amine-group compounds M1 is three (3,6- bis- Oxa- heptyl) amine, three (3,6,9,12- tetra- oxa- tridecyl) amine or three (3,6,9,12,15,18- six oxa- nonadecyls) Amine.

5. method according to claim 2, which is characterized in that the chemical structural formula of the halogenosulfonic acid salt compound M2 Are as follows:

X-R₂-SO₃ ^-M⁺

Wherein X is chlorine atom, bromine atom or iodine atom, R₂For alkane chain-(CH₂CH₂)_n, n=2~6；M⁺Be positive monovalent metal Ion is sodium ion, lithium ion or potassium ion.

6. method according to claim 2, which is characterized in that the halogenosulfonic acid salt compound M2 is 2- bromoethyl sulphur Sour sodium, 2- bromoethyl Sulfonic Lithium or 2- bromoethyl potassium sulfonate, 2- iodine ethylsulfonic acid lithium, 2- chloroethyl sodium sulfonate, 2- brombutyl sulphur Sour potassium, 2- bromine hexyl Sulfonic Lithium.

7. method according to claim 2, which is characterized in that the chemical structural formula of the salt compounds M3 are as follows:

M⁺R^-

Wherein, M⁺Be positive monovalent metallic ion, is sodium ion, lithium ion or potassium ion；R^-Be negative univalent anion, is perchloric acid Root, two (trimethyl fluoride sulfonyl) imines, bis- (fluorine sulphonyl) imines, tetrafluoroborate or dioxalic acid borate.

8. compound M3 according to claim 2, which is characterized in that the salt compounds M3 is sodium perchlorate, two (trimethyl fluoride sulfonyl) imines sodium, bis- (fluorine sulphonyl) imines sodium, sodium tetrafluoroborate, dioxalic acid Boratex, lithium perchlorate, two (three Methyl fluoride sulphonyl) imine lithium, bis- (fluorine sulphonyl) imine lithiums, LiBF4, dioxalic acid lithium borate, potassium hyperchlorate, two (fluoroforms Base sulphonyl) any one in imines potassium, bis- (fluorine sulphonyl) imines potassium, potassium tetrafluoroborate or dioxalic acid potassium borate.