Production method of imidodisulfuryl fluoride and production method of lithium imidodisulfuryl fluoride

Abstract

The invention relates to a production method of imidodisulfuryl fluoride and a production method of lithium imidodisulfuryl fluoride, the production method of imidodisulfuryl fluoride takes sulfamic acid, chlorosulfonic acid and thionyl chloride as raw materials, imidodisulfuryl fluoride is obtained through chlorination reaction, imidodisulfuryl fluoride and hydrofluoric acid or imidodisulfuryl fluoride and hydrogen fluoride gas are taken as raw materials, imidodisulfuryl fluoride and hydrogen fluoride gas are subjected to chlorination reaction to obtain imidodisulfuryl fluoride. The invention discloses a method for producing bis (fluorosulfonyl) imide, which comprises the following steps: by taking bis (fluorosulfonyl) imide as a raw material, carrying out fluoridation reaction to prepare a bis (fluorosulfonyl) imide crude product, adding metal salt into the bis (fluorosulfonyl) imide crude product, and then carrying out melt crystallization and / or rectification. According to the method, the metal salt is added into the difluorosulfonyl imide crude product, so that the metal salt can react with a light component in a fluorination reaction system or a component with a boiling point similar to that of the target product difluorosulfonyl imide, and the impurities react to generate salt with a relatively high boiling point; therefore, the components can be separated from the target product imidodisulfuryl fluoride in the subsequent purification process, and the purity of imidodisulfuryl fluoride is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a production method of bisfluorosulfonyl imide and a production method of bisfluorosulfonyl imide lithium. Background Art

[0002] Lithium bis(fluorosulfonyl)imide (LiFSI) is a new type of electrolyte lithium salt with the molecular formula Li[N(SO2F)2], relative molecular mass of 187.07, and CAS number 171611-11-3. It is considered to be the most likely electrolyte lithium salt to replace lithium hexafluorophosphate. LiFSI has the following characteristics: (1) Compared with lithium hexafluorophosphate, LiFSI is easier to dissociate into lithium ions, so LiFSI has higher conductivity; (2) The decomposition temperature of LiFSI is higher than 200℃, and LiFSI has higher thermal stability and safety; (3) LiFSI has good compatibility with electrodes and has unique advantages in improving low-temperature discharge and high-temperature storage; (4) It is environmentally friendly, highly safe, and has the basic conditions for industrialization, and has gradually become the focus of attention in the battery field.

[0003] The synthesis of lithium bis(fluorosulfonyl)imide generally involves the following three steps: synthesis of bis(chlorosulfonyl)imide; preparation of bis(fluorosulfonyl)imide by fluorination of bis(chlorosulfonyl)imide; preparation of bis(fluorosulfonyl)imide alkali metal salt.

[0004] In the related art, the patent document with publication number CN101747242A discloses a method for preparing an alkali metal salt of (perfluoroalkylsulfonyl fluorosulfonyl)imide. The scheme uses sulfonamide to react with dichlorothionyl and chlorosulfonic acid to prepare bis(chlorosulfonyl)imide or (perfluoroalkylsulfonyl chlorosulfonyl)imide, and then reacts it with antimony trifluoride and potassium carbonate (rubidium or cesium) to obtain the corresponding high-purity bis(fluorosulfonyl)imide potassium (rubidium or cesium) salt or (perfluoroalkylsulfonyl fluorosulfonyl)imide potassium (rubidium or cesium) salt; the potassium (rubidium or cesium) salt is subjected to a double decomposition exchange reaction with lithium perchlorate (or sodium) or lithium tetrafluoroborate (or sodium) in a non-protonic polar solvent to obtain a high-purity corresponding lithium (or sodium) salt. However, this solution has the following defects: the reaction steps are too long, the price of antimony trifluoride is relatively high, it is difficult to achieve industrial-scale production, the raw material consumption is large, a large amount of waste is generated, the product has many impurities, and it is difficult to purify to meet the application needs of new energy devices such as lithium-ion batteries and supercapacitors.

[0005] Patent documents with publication numbers of US20120020867A1, EP2415757A1, and WO2010113835A1 use sulfuryl fluoride and ammonia to react to prepare bis(fluorosulfonyl)imide, which is then lithiated with a lithiation agent to obtain the target compound. However, this route is highly exothermic during the synthesis process, and the reactants are all in gaseous state. The reaction needs to be carried out in an autoclave, and the reaction is uncontrollable and produces a large number of by-products.

[0006] Patent document with publication number WO2009123328A1 uses cyanogen chloride gas and sulfur trioxide to prepare chlorosulfonic acid isocyanate, which is then reacted with chlorosulfonic acid to prepare bischlorosulfonyl imide, and then fluorinated and lithium-substituted to obtain the target compound. However, this route uses highly toxic gas cyanogen chloride, which is difficult to scale up production.

[0007] In summary, most of the methods currently used are to synthesize bis(chlorosulfonyl)imide by public methods, and then fluorination, alkali metal double decomposition and other processes are used to prepare bis(fluorosulfonyl)imide and alkali metal salts. However, the production process of the above method is too long, the raw material consumption is too large, and the waste production is too much, which makes it difficult to scale up industrially and meet the application requirements of mainstream electrolyte materials in new energy devices such as lithium-ion batteries and supercapacitors. Summary of the invention

[0008] In view of this, the present invention provides a method for producing bisfluorosulfonyl imide and a method for producing lithium bisfluorosulfonyl imide to solve the technical problems that the production process of the above-mentioned lithium bisfluorosulfonyl imide is too long, the raw material consumption is too large, the waste production is too much, it is difficult to scale up industrially, and it is difficult to meet the application requirements of mainstream electrolyte materials in new energy devices such as lithium ion batteries and supercapacitors.

[0009] To achieve the above solution, the technical solution of the present invention is as follows:

[0010] The present invention provides a method for producing bisfluorosulfonyl imide, which comprises taking aminosulfonic acid, chlorosulfonic acid and thionyl chloride as raw materials, performing a chlorination reaction to obtain bischlorosulfonyl imide, and then taking bischlorosulfonyl imide and hydrofluoric acid or taking bischlorosulfonyl imide and hydrogen fluoride gas as raw materials, performing a fluorination reaction to obtain a crude bisfluorosulfonyl imide. The method for producing bisfluorosulfonyl imide further comprises:

[0011] A metal salt is added to the crude bisfluorosulfonyl imide, followed by melt crystallization and / or rectification.

[0012] Optionally, the metal salt is selected from sodium chloride, calcium chloride or a combination thereof.

[0013] Optionally, the mass ratio of the metal salt to the impurities in the crude bis(fluorosulfonyl)imide is 1:0.5-3.0.

[0014] Optionally, after adding the metal salt and before melt crystallization and / or rectification, the method for producing bisfluorosulfonyl imide further comprises: pumping gas until no gas is generated.

[0015] Optionally, the molar ratio of aminosulfonic acid, chlorosulfonic acid and thionyl chloride is 1:1:2.2-3.0.

[0016] Optionally, the temperature of the chlorination reaction is 100°C-120°C, and the duration of the chlorination reaction is 18-30h.

[0017] Optionally, if bischlorosulfonyl imide and hydrofluoric acid are used as raw materials, the temperature of the fluorination reaction is 5-20° C., and the duration of the fluorination reaction is 3-8 hours.

[0018] Optionally, if bischlorosulfonyl imide and hydrogen fluoride gas are used as raw materials, the temperature of the fluorination reaction is 100-120° C., and the duration of the fluorination reaction is 8-24 hours.

[0019] In a second aspect, the present application also provides a method for producing lithium bis(fluorosulfonyl)imide, which uses an alkaline lithium salt and lithium bis(fluorosulfonyl)imide prepared according to the method described above as raw materials, and undergoes a lithiation reaction in a solvent to obtain the lithium bis(fluorosulfonyl)imide.

[0020] Optionally, the alkaline lithium salt is selected from at least one of lithium hydroxide monohydrate, lithium carbonate and lithium bicarbonate.

[0021] Optionally, the molar ratio of the alkaline lithium salt to the target product lithium bis(fluorosulfonyl)imide is 0.95-1.1:1.

[0022] Optionally, the solvent is selected from at least one of cyclohexane, dichloromethane, dichloroethane, toluene, acetonitrile and dimethyl carbonate.

[0023] Optionally, the mass ratio of the solvent to the target product lithium bis(fluorosulfonyl)imide is 3-4:1.

[0024] Optionally, the production method of lithium bis(fluorosulfonyl)imide further comprises:

[0025] Add thionyl chloride dropwise to the system after the lithiation reaction to separate the solid and liquid.

[0026] Optionally, the molar ratio of the thionyl chloride to the target product lithium bis(fluorosulfonyl)imide is 0.5-3.5:1.

[0027] Optionally, thionyl chloride is added dropwise to the system after the lithiation reaction, and the solid-liquid separation is carried out after 10-18 hours.

[0028] Optionally, the method for producing lithium bis(fluorosulfonyl)imide further includes.

[0029] A slurry solvent and a metal ion remover are added to the system after the lithiation reaction, and the system is blown dry in a protective gas atmosphere.

[0030] Optionally, the pulping solvent is selected from at least one of cyclohexane, dichloromethane, dichloroethane, toluene and chlorobenzene.

[0031] Optionally, the mass ratio of the slurry solvent to the target product lithium bis(fluorosulfonyl)imide is 1.5-3.0:1.

[0032] Optionally, the metal ion remover is selected from 18-crown-6 or 15-crown-5 or a combination of the two.

[0033] Optionally, the mass ratio of the metal ion remover to the target product lithium bis(fluorosulfonyl)imide is 0.02-0.1:100.

[0034] Optionally, the duration of the blow drying is 4-10 hours.

[0035] Optionally, the production method of lithium bis(fluorosulfonyl)imide further comprises:

[0036] A recrystallization solvent is added to the system after the lithiation reaction to perform recrystallization.

[0037] Optionally, the recrystallization solvent is selected from at least one of dimethyl carbonate, diethyl carbonate, acetonitrile, ethyl acetate, dichloromethane, ethyl methyl carbonate and ethanol.

[0038] Optionally, the mass ratio of the recrystallization solvent to the target product lithium bis(fluorosulfonyl)imide is 2.0-4.0:1.

[0039] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application.

[0040] The beneficial effects of the present invention are as follows:

[0041] The present application adds a metal salt to the crude bisfluorosulfonyl imide, so that the metal salt can react with light components in the fluorination reaction system or components with a boiling point close to the target product bisfluorosulfonyl imide, so that these impurities react to generate salts with a higher boiling point, so as to separate these components from the target product bisfluorosulfonyl imide in the subsequent purification process, thereby improving the purity of the bisfluorosulfonyl imide. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] An embodiment of the present invention provides a method for producing bisfluorosulfonyl imide, wherein sulfamic acid, chlorosulfonic acid and thionyl chloride are used as raw materials, and the molar ratio of sulfamic acid, chlorosulfonic acid and thionyl chloride is 1:1:2.2-3.0, and bischlorosulfonyl imide is obtained by chlorination reaction, the temperature of the chlorination reaction is 100°C-120°C, and the duration of the chlorination reaction is 18-30 hours; then bischlorosulfonyl imide and hydrofluoric acid or bischlorosulfonyl imide and hydrogen fluoride gas are used as raw materials, and fluorination reaction is carried out to obtain a crude bisfluorosulfonyl imide, if bischlorosulfonyl imide and hydrofluoric acid are used as raw materials, the temperature of the fluorination reaction is 5-20°C, and the duration of the fluorination reaction is 3-8 hours;

[0044] If bischlorosulfonyl imide and hydrogen fluoride gas are used as raw materials, the temperature of the fluorination reaction is 100-120° C., and the duration of the fluorination reaction is 8-24 hours.

[0045] The production method of bis(fluorosulfonyl)imide also includes:

[0046] Add a metal salt to the crude bisfluorosulfonyl imide, wherein the metal salt is selected from sodium chloride, calcium chloride or a combination thereof, and the mass ratio of the metal salt to the impurities in the crude bisfluorosulfonyl imide is 1:0.5-3.0. Vacuum is pumped until no gas is generated, followed by melt crystallization and / or rectification.

[0047] Another embodiment of the present invention also provides a method for producing lithium bis(fluorosulfonyl)imide, using the lithium bis(fluorosulfonyl)imide prepared according to the above method and an alkaline lithium salt as raw materials, and subjecting the lithium bis(fluorosulfonyl)imide to a lithiation reaction in a solvent to obtain the lithium bis(fluorosulfonyl)imide, wherein the alkaline lithium salt is selected from at least one of lithium hydroxide monohydrate, lithium carbonate and lithium bicarbonate.

[0048] The molar ratio of the alkaline lithium salt to the target product lithium bis(fluorosulfonyl)imide is 0.95-1.1:1, the solvent is selected from at least one of cyclohexane, dichloromethane, dichloroethane, toluene, acetonitrile and dimethyl carbonate, and the mass ratio of the solvent to the target product lithium bis(fluorosulfonyl)imide is 3-4:1.

[0049] In another embodiment of the present invention, the method for producing lithium bis(fluorosulfonyl)imide further comprises:

[0050] Sulfonyl chloride is added dropwise to the system after the lithiation reaction, wherein the molar ratio of thionyl chloride to the target product lithium bis(fluorosulfonyl)imide is 0.5-3.5:1, and solid-liquid separation is performed after 10-18 hours.

[0051] In another embodiment of the present invention, the method for producing lithium bis(fluorosulfonyl)imide further comprises:

[0052] A pulping solvent and a metal ion remover are added to the system after the lithiation reaction, wherein the pulping solvent is selected from at least one of cyclohexane, dichloromethane, dichloroethane, toluene and chlorobenzene, and the mass ratio of the pulping solvent to the target product lithium bis(fluorosulfonyl)imide is 1.5-3.0:1; the metal ion remover is selected from 18-crown ether-6 or 15-crown ether-5 or a combination of the two, and the mass ratio of the metal ion remover to the target product lithium bis(fluorosulfonyl)imide is 0.02-0.1:100; and the system is blown and dried in a protective gas atmosphere for 4-10 hours.

[0053] In another embodiment of the present invention, the method for producing lithium bis(fluorosulfonyl)imide further comprises:

[0054] A recrystallization solvent is added to the system after the lithiation reaction for recrystallization, wherein the recrystallization solvent is selected from at least one of dimethyl carbonate, diethyl carbonate, acetonitrile, ethyl acetate, dichloromethane, ethyl methyl carbonate and ethanol, and the mass ratio of the recrystallization solvent to the target product lithium bis(fluorosulfonyl)imide is 2.0-4.0:1.

[0055] The present invention is described in detail below by specific examples. It should also be understood that the following examples are only used to specifically illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values ​​​​exemplified below.

[0056] Example 1

[0057] A method for producing bisfluorosulfonyl imide, the specific steps are as follows:

[0058] S1. 194 g of sulfamic acid, 233 g of chlorosulfonic acid and 580 g of thionyl chloride were added to a dry reaction vessel to obtain a mixed solution, which was replaced with nitrogen;

[0059] The mixed solution was heated to 112°C, stirred for 22 hours, then cooled to 85°C, and the residual acid gas was pumped out by a water pump for 4 hours; short-path distillation was then performed to collect the transparent colorless liquid under the vacuum condition of 110°C / 150Pa, thus obtaining 403.2 g of bischlorosulfonyl imide, with a yield of 94.2%;

[0060] S3. At a constant temperature of 8°C, 100 g of liquid hydrogen fluoride was added to a dry container, and then 321 g of bis(chlorosulfonyl)imide was slowly added dropwise to carry out a fluorination reaction. After the addition of bis(chlorosulfonyl)imide was completed, the reaction was continued at room temperature for 5 h, and then the mixture was heated to 40°C to distill and recover hydrogen fluoride; the remaining solution was distilled under reduced pressure, and the fraction at 55-60°C / 150pa was collected to obtain 265.4 g of colorless bis(fluorosulfonyl)imide (i.e., crude bis(fluorosulfonyl)imide, the purity of which was detected by ion chromatography, and the purity of which was 94.8%);

[0061] S3. Add 8.0 g of sodium chloride to the colorless liquid of bis(fluorosulfonyl)imide and stir, remove the generated gas with a water pump, and obtain 249.6 g of bis(fluorosulfonyl)imide product by distillation. The yield is calculated to be 91.9%.

[0062] The purity of the bis(fluorosulfonyl)imide product was measured by ion chromatography, and the purity of the bis(fluorosulfonyl)imide product was 99.5%.

[0063] Example 2

[0064] Bisfluorosulfonyl imide was produced in the same manner as in Example 1 except for the following conditions:

[0065] S3. Add 17.0 g of calcium chloride to the colorless liquid of bisfluorosulfonyl imide (the purity of bisfluorosulfonyl imide was detected by ion chromatography, and the purity of bisfluorosulfonyl imide was 95.2%) and stir, remove the generated gas with a water pump, and obtain 247.3 g of bisfluorosulfonyl imide product by distillation. The yield is calculated to be 91.1%.

[0066] The purity of the bis(fluorosulfonyl)imide product was measured by ion chromatography. After testing, the purity of the bis(fluorosulfonyl)imide product was 99.3%.

[0067] Example 3

[0068] Bisfluorosulfonyl imide was produced in the same manner as in Example 1 except for the following conditions:

[0069] S3. Add 10.0 g of sodium chloride to the colorless liquid of bisfluorosulfonyl imide (the purity of bisfluorosulfonyl imide was detected by ion chromatography, and the purity of bisfluorosulfonyl imide was 93.8%) and stir, remove the generated gas with a water pump, distill and melt crystallize to obtain 246.3 g of bisfluorosulfonyl imide product, and the yield is calculated to be 90.7%.

[0070] The purity of the bis(fluorosulfonyl)imide product was tested by ion chromatography, and the purity of the bis(fluorosulfonyl)imide product was 99.95%.

[0071] Example 4

[0072] A method for producing lithium bis(fluorosulfonyl)imide, comprising the following steps:

[0073] A. Add 22.8g Li2CO3 and 393g dichloromethane to the reaction flask, cool to 3°C, and add 115g of the bis(fluorosulfonyl)imide product obtained in Example 1 dropwise under stirring. The addition is completed within about 1h. After the addition is completed, keep the temperature and continue the reaction for 2h;

[0074] B. Raise the temperature to 25°C, drop 60 g SOCl2 into the reaction flask, stir for 18 h, filter, add 150 g anhydrous dichloroethane and 0.05 g 18-crown ether-6 to the filter cake for pulping, filter, blow nitrogen for 8 h, and obtain 107.5 g lithium bis(fluorosulfonyl)imide product with a yield of 93.1%.

[0075] The purity of the lithium bis(fluorosulfonyl)imide product was detected by ion chromatography. The purity of the lithium bis(fluorosulfonyl)imide product was found to be 99.96%.

[0076] Example 5

[0077] A method for producing lithium bis(fluorosulfonyl)imide, comprising the following steps:

[0078] A. Add 28.8g LiOH·H2O and 480g dichloromethane to the reaction flask, cool to 8°C, and drop 127g of the bis(fluorosulfonyl)imide product obtained in Example 2 under stirring. The dropwise addition is controlled to be completed within about 1 hour. After the dropwise addition is completed, the reaction is continued for 2 hours under heat preservation;

[0079] B. Raise the temperature to 20°C, drop 240 g SOCl2 into the reaction flask, stir for 16 h, filter, add 210.0 g anhydrous dichloromethane and 0.08 g 15-crown ether-6 to the filter cake for pulping, filter, blow nitrogen for 8 h, and obtain 104.2 g lithium bis(fluorosulfonyl)imide product with a yield of 90.3%.

[0080] The purity of the lithium bis(fluorosulfonyl)imide product was detected by ion chromatography. After detection, the purity of the lithium bis(fluorosulfonyl)imide product was 99.93%.

[0081] Example 6

[0082] Lithium bis(fluorosulfonyl)imide was produced in the same manner as in Example 5 except for the following conditions:

[0083] B. Raise the temperature to 20°C, drop 240g SOCl2 into the reaction flask, stir for 16h, filter, add 360g anhydrous dichloromethane to the filter cake for recrystallization, and obtain 102.9g lithium bis(fluorosulfonyl)imide product with a yield of 89.2%.

[0084] The purity of the lithium bis(fluorosulfonyl)imide product was detected by ion chromatography. The purity of the lithium bis(fluorosulfonyl)imide product was found to be 99.97%.

[0085] Comparative Example 1

[0086] Bisfluorosulfonyl imide was produced in the same manner as in Example 1 except for the following conditions:

[0087] S3. The colorless liquid bisfluorosulfonyl imide (the purity of bisfluorosulfonyl imide was detected by ion chromatography, and the purity of bisfluorosulfonyl imide was 94.3%) was distilled to obtain 250.1 g of bisfluorosulfonyl imide product with a yield of 92.1%.

[0088] The purity of the bis(fluorosulfonyl)imide product was tested by ion chromatography, and the purity of the bis(fluorosulfonyl)imide product was 95.6%.

[0089] From the above content, it can be seen that compared with Comparative Example 1 (sodium chloride is not added to the fluorination reaction system), the purity of the bisfluorosulfonyl imide prepared in Example 1 (sodium chloride is added to the fluorination reaction system) is significantly increased. This result shows that the present application, by adding metal salts such as sodium chloride to the fluorination reaction system, can react these metal salts with light components in the fluorination reaction system or components with a boiling point close to the target product bisfluorosulfonyl imide so that these impurities react to generate salts with higher boiling points, so as to separate these components from the target product bisfluorosulfonyl imide in the subsequent purification process, thereby improving the purity of the bisfluorosulfonyl imide.

[0090] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for producing bisfluorosulfonyl imide, comprising: using aminosulfonic acid, chlorosulfonic acid and thionyl chloride as raw materials, subjecting bischlorosulfonyl imide to chlorination reaction, and then using bischlorosulfonyl imide and hydrofluoric acid or bischlorosulfonyl imide and hydrogen fluoride gas as raw materials, subjecting fluorination reaction to obtain a crude bisfluorosulfonyl imide, characterized in that: The production method of the bisfluorosulfonyl imide also includes: A metal salt is added to the crude bisfluorosulfonyl imide, followed by melt crystallization and / or rectification.

2. The method for producing bis(fluorosulfonyl)imide according to claim 1, characterized in that: The metal salt is selected from sodium chloride, calcium chloride or a combination thereof.

3. The method for producing bisfluorosulfonyl imide according to claim 1, characterized in that: The mass ratio of the metal salt to the impurities in the crude bis(fluorosulfonyl)imide is 1:0.5-1:3.

0.

4. The method for producing bis(fluorosulfonyl)imide according to claim 1, characterized in that: After adding the metal salt and before melt crystallization and / or rectification, the method for producing bisfluorosulfonyl imide further comprises: pumping gas until no gas is generated.

5. The method for producing bis(fluorosulfonyl)imide according to claim 1, characterized in that: The molar ratio of aminosulfonic acid, chlorosulfonic acid and thionyl chloride is 1:1:2.2-3.0; And / or, the temperature of the chlorination reaction is 100° C.-120° C., and the duration of the chlorination reaction is 18-30 hours; And / or, if bischlorosulfonyl imide and hydrofluoric acid are used as raw materials, the temperature of the fluorination reaction is 5-20° C., and the duration of the fluorination reaction is 3-8 hours; Alternatively, if bischlorosulfonyl imide and hydrogen fluoride gas are used as raw materials, the temperature of the fluorination reaction is 100-120° C., and the duration of the fluorination reaction is 8-24 hours.

6. A method for producing lithium bis(fluorosulfonyl)imide, characterized in that: The lithium bis(fluorosulfonyl)imide is prepared by using an alkaline lithium salt and the lithium bis(fluorosulfonyl)imide prepared by the method according to any one of claims 1 to 5 as raw materials and undergoing a lithiation reaction in a solvent to prepare the lithium bis(fluorosulfonyl)imide.

7. The method for producing lithium bis(fluorosulfonyl)imide according to claim 6, characterized in that: The alkaline lithium salt is selected from at least one of lithium hydroxide monohydrate, lithium carbonate and lithium bicarbonate; And / or, the solvent is selected from at least one of cyclohexane, dichloromethane, dichloroethane, toluene, acetonitrile and dimethyl carbonate.

8. The method for producing lithium bis(fluorosulfonyl)imide according to claim 6, characterized in that: The molar ratio of the alkaline lithium salt to the target product lithium bis(fluorosulfonyl)imide is 0.95-1.1:1; And / or, the mass ratio of the solvent to the target product lithium bis(fluorosulfonyl)imide is 3-4:

1.

9. The method for producing lithium bis(fluorosulfonyl)imide according to claim 6, characterized in that: The production method of lithium bis(fluorosulfonyl)imide further comprises: Add thionyl chloride dropwise to the system after the lithiation reaction to separate the solid and the liquid; Alternatively, the production method of lithium bis(fluorosulfonyl)imide further comprises: Adding a slurry solvent and a metal ion remover to the system after the lithiation reaction, and performing blowing drying in a protective gas atmosphere; Alternatively, the production method of lithium bis(fluorosulfonyl)imide further comprises: A recrystallization solvent is added to the system after the lithiation reaction to perform recrystallization.

10. The method for producing lithium bis(fluorosulfonyl)imide according to claim 9, characterized in that: The molar ratio of thionyl chloride to the target product lithium bis(fluorosulfonyl)imide is 0.5-3.5:1; and / or, adding thionyl chloride dropwise to the system after the lithiation reaction, and performing solid-liquid separation after 10-18 hours; Or, the pulping solvent is selected from at least one of cyclohexane, dichloromethane, dichloroethane, toluene and chlorobenzene; And / or, the metal ion remover is selected from 18-crown-6 or 15-crown-5 or a combination of the two; and / or, the mass ratio of the metal ion remover to the target product lithium bis(fluorosulfonyl)imide is 0.02-0.1:100; And / or, the duration of the blow drying is 4-10 hours; Alternatively, the recrystallization solvent is selected from at least one of dimethyl carbonate, diethyl carbonate, acetonitrile, ethyl acetate, dichloromethane, ethyl methyl carbonate and ethanol.