Dihalogenated sulfimide and preparation method thereof, and method for preparing dihalogenated sulfimide salt

Abstract

The invention belongs to the technical field of lithium battery materials, and discloses dihalogen sulfimide, a preparation method thereof and a method for preparing dihalogen sulfimide salt, the preparation method comprises the following steps: carrying out first reaction on ammonia gas and first halogen sulfonic acid to obtain halogen sulfonic acid ammonium salt; carrying out a second reaction on the ammonium halosulfonate and sulfur trioxide to obtain halosulfonamide; and carrying out a third reaction on the halogen sulfonamide, the sulfur trioxide and the second halogen sulfonic acid to obtain the dihalogen sulfonimide and sulfuric acid. The preparation method is simple and environment-friendly in process, the product is easy to purify, the byproduct is only sulfuric acid and can be recycled, and the prepared dihalogenated sulfimide is relatively high in purity and yield.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium battery materials, and particularly relates to a bis-halosulfimide, a preparation method thereof, and a method for preparing a bis-halosulfimide salt. BACKGROUND

[0002] With the rapid development of the markets of electronic equipment, electric vehicles, smart home, electric tools, intelligent transportation, etc., the demand for batteries is also increasing. For lithium batteries, the most widely used electrolyte lithium salt is lithium hexafluorophosphate, which has good comprehensive performance. However, due to its instability, easy water absorption, short service life, poor low-temperature performance and other shortcomings, it is not sufficient to meet the increasingly expanding application requirements of lithium-ion batteries.

[0003] Compared with lithium hexafluorophosphate, lithium bis-halosulfimide (LiXSI) has better thermal stability, chemical stability, higher conductivity and lower corrosion rate, and is considered to replace lithium hexafluorophosphate and become a new generation of lithium salt, which can be widely applied to lithium batteries and supercapacitors. At present, the preparation method of LiXSI is mostly to obtain lithium bis-halosulfimide by lithiation. However, the method for synthesizing bis-halosulfimide in the related art is complex, and the generated products are of many types, resulting in high difficulty in purification, affecting the purity and yield of bis-halosulfimide, or being not environmentally friendly. It would be of great significance to develop a method for preparing bis-halosulfimide with simple process, easy purification of product and environmental protection. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art. To this end, the present application provides a method for preparing bis-halosulfimide with simple process, easy purification and only sulfuric acid as by-product, and a bis-halosulfimide prepared by the method and a method for preparing a bis-halosulfimide salt.

[0005] The first aspect of the present application provides a method for synthesizing bis-halosulfimide, comprising: allowing ammonia gas to react with a first halosulfonic acid to obtain an ammonium halosulfonate; allowing the ammonium halosulfonate to react with sulfur trioxide to obtain a halosulfamide; and allowing the halosulfamide to react with the sulfur trioxide and a second halosulfonic acid to obtain bis-halosulfimide and sulfuric acid.

[0006] The preparation method uses halogen sulfonic acid and ammonia gas as reactants to directly provide the required skeleton structure of bis-halogen sulfonylimide, i.e., key atoms such as S, N, X, and the like, and then sulfur trioxide is introduced into the reaction system as an activating agent to accelerate the reaction, and the final product is only bis-halogen sulfonylimide and sulfuric acid. Thus, the reaction process is simple and environmentally friendly, the reaction time is short, the product is extremely easy to purify, the product purity is high (e.g., ≥ 99%), and the separated sulfuric acid can be recycled, which can reduce the waste of raw materials to some extent, save costs, and at the same time, there are no toxic and harmful by-products such as sulfur dioxide and hydrogen chloride which are difficult to handle.

[0007] In addition, the preparation method according to the above embodiments of the present application can also have the following additional technical features: In some embodiments, the first reaction of ammonia gas with the first halogen sulfonic acid includes introducing ammonia gas into a solvent to obtain a first mixture, adding the first halogen sulfonic acid to the first mixture, and continuously reacting for a predetermined time to obtain the ammonium halogen sulfonate. Thus, the ammonium halogen sulfonate can be prepared by one-step reaction, which helps to promote the subsequent reaction to generate bis-halogen sulfonylimide.

[0008] In some embodiments, the first reaction of ammonia gas with the first halogen sulfonic acid includes introducing ammonia gas into the first halogen sulfonic acid and continuously reacting for the predetermined time to obtain the ammonium halogen sulfonate. Thus, ammonia gas can be directly introduced into the first halogen sulfonic acid for reaction without the need for a solvent, which is more convenient to operate.

[0009] In some embodiments, the method for synthesizing bis-halogen sulfonylimide satisfies at least one of the following conditions: The predetermined time is 3 min to 60 min; The temperature of the first reaction is 0°C to 40°C; The molar ratio of the ammonia gas to the ammonium halogen sulfonate is 1-5:1; The first halogen sulfonic acid is added dropwise to the first mixture; The solvent includes at least one of acetonitrile, dichloromethane, dichloroethane, dimethyl carbonate, and methyl ethyl carbonate.

[0010] Thus, under the above reaction conditions, the reaction can proceed smoothly, and the reaction speed is fast, the reaction is sufficient, the reaction conditions are mild, and the reaction time is short.

[0011] In some embodiments, the first halogen sulfonic acid and the second halogen sulfonic acid include at least one of fluorosulfonic acid and chlorosulfonic acid. The above halogen sulfonic acids are superacids with high reactivity, which helps to promote the forward reaction.

[0012] In some embodiments, the second reaction and the third reaction comprise: mixing the ammonium halosulfonate with sulfur trioxide and performing a second reaction to obtain a second mixture; adding the second halosulfonic acid to the second mixture and performing a third reaction to obtain the bis-halosulfonyl imide and sulfuric acid. In this way, the ammonium halosulfonate can first react with sulfur trioxide to generate a halosulfonamide and sulfuric acid, and the halosulfonamide can further react with the halosulfonic acid and sulfur trioxide to obtain the bis-halosulfonyl imide and sulfuric acid. The preparation steps are simple, the types of obtained products are few, the products are easy to purify, the by-product sulfuric acid can be recycled, the economic benefits are good, no toxic and harmful substances are generated, and the post-processing is simple.

[0013] In some embodiments, the method for synthesizing the bis-halosulfonyl imide satisfies at least one of the following conditions: The temperature of the second reaction is 30-60°C; The time of the second reaction is 1-6h; The temperature of the third reaction is 30-150°C; The time of the third reaction is 1-10h; The molar ratio of the ammonium halosulfonate, the sulfur trioxide and the second halosulfonic acid is 1:2:1-2:4:1.

[0014] Under the above conditions, the second reaction and the third reaction can be carried out smoothly and efficiently, and the reaction conditions are mild and the reaction time is short.

[0015] In some embodiments, the method for synthesizing the bis-halosulfonyl imide further comprises: performing vacuum distillation on the product of the third reaction to obtain the bis-halosulfonyl imide. In this way, it is helpful to obtain bis-halosulfonyl imide with high purity.

[0016] In some embodiments, when the bis-halosulfonyl imide is bis-chlorosulfonyl imide, the fraction of 140-180°C and -0.092-0.098MPa is collected to obtain the bis-chlorosulfonyl imide.

[0017] In some embodiments, when the bis-halosulfonyl imide is bis-fluorosulfonyl imide, the fraction of 80-110°C and -0.092-0.098MPa is collected to obtain the bis-fluorosulfonyl imide.

[0018] The second aspect of the present application proposes a bis-halosulfonyl imide prepared by the method for preparing the bis-halosulfonyl imide described above. The bis-halosulfonyl imide has high purity and few impurities, can undergo a lithiation reaction to prepare bis-fluorosulfonyl imide lithium, and can be used in lithium batteries as a lithium salt.

[0019] In a third aspect, the present application provides a method for preparing a bis-halosulfimide salt. According to an embodiment of the present application, the method comprises: preparing a bis-halosulfimide by the method described above; and subjecting the bis-halosulfimide to a salt-forming reaction with a metal compound to obtain a bis-halosulfimide salt. The method is simple and convenient to operate, and the obtained bis-halosulfimide salt has high purity and good quality, and can be used to prepare a battery. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a Raman spectrum of the bis-chlorosulfimide prepared in Example 1 of the present application; Figure 2 is a nuclear magnetic F spectrum of the bis-chlorosulfimide prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, which are intended to explain the present application and cannot be understood as a limitation of the present application.

[0022] The present application is based on the following findings and recognitions of the inventors: As described above, the method for preparing a bis-halosulfimide in the related art is complex, and the obtained product is complex to purify, resulting in low purity of the prepared bis-halosulfimide. For example, in the related art, sulfur trioxide, ammonia and dichlorosulfoxide are used for reaction, and the product is bis-chlorosulfimide, hydrochloric acid and sulfur dioxide. The direct discharge of sulfur dioxide causes a certain degree of pollution to the environment, and the hydrochloric acid in the product also needs to be removed by vacuum distillation to obtain bis-chlorosulfimide, so the preparation process is relatively complex. In order to solve the above problems to some extent, the inventors have developed a new method for preparing a bis-halosulfimide, which is simple in preparation method, has few by-products, can be resourceized, and has high purity of the obtained product and is environmentally friendly in the preparation process.

[0023] In a first aspect, the present application provides a method for synthesizing a bis-halosulfimide, comprising the following steps: S10: subjecting ammonia gas to a first reaction with a first halosulfonic acid to obtain an ammonium halosulfonate.

[0024] In this step, the equation for the reaction of ammonia gas with the first halosulfonic acid is as follows. In the first halosulfonic acid molecule, the strong electron-withdrawing property of the S=O bond makes the S atom positively charged, which is easily attacked by the nucleophile ammonia gas to obtain an ammonium halosulfonate, which helps to quickly build a nitrogen-containing skeleton.

[0025]

[0026] wherein X is F or Cl.

[0027] In some embodiments, the ammonia gas can be introduced into the solvent to obtain a first mixture, and then the first halosulfonic acid is added to the first mixture, and the reaction is continued for a predetermined time to obtain the ammonium halosulfonate salt.

[0028] In some embodiments, the solvent that can be used includes at least one of acetonitrile, dichloromethane, dichloroethane, dimethyl carbonate, and methyl ethyl carbonate. Thus, the solvent can dissolve the first halosulfonic acid and the ammonia gas to form a homogeneous reaction system, which promotes the forward reaction, and the solvent is chemically stable and less likely to have side reactions with the ammonia gas and the first halosulfonic acid. In addition, the solvent can isolate the moisture in the system to prevent the hydrolysis of the first halosulfonic acid and the decomposition of the product.

[0029] In some embodiments, the specific method of adding the first halosulfonic acid to the obtained first mixture is not particularly limited. For example, the first halosulfonic acid can be added dropwise to the first mixture. Thus, the reaction can be effectively promoted to proceed in the forward direction, which is beneficial to improve the yield of the product.

[0030] In some embodiments, the ammonia gas can be directly introduced into the first halosulfonic acid, and the reaction can be continued for the predetermined time to obtain the ammonium halosulfonate salt. Thus, the solvent can not be needed, and the ammonia gas can be directly introduced into the first halosulfonic acid for reaction, which is more convenient to operate.

[0031] In some embodiments, the predetermined time can be 3 min to 60 min, specifically, 3 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc. Within the above time range, the reaction can be sufficiently carried out, which is beneficial to improve the yield of the product, and the yield will not be reduced due to too short time, and the time will not be wasted due to too long time.

[0032] In some embodiments, the temperature of the first reaction can be 0°C to 40°C, specifically, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc. Within the above temperature range, the first reaction can be smoothly carried out, and the reaction speed is relatively fast, the reaction conditions are mild, the requirement for equipment is relatively low, and the industrial production is easy to realize. The reaction speed will not be too slow due to too low temperature, and the reactants will not be decomposed, the side reactions will not be increased, or the requirement for equipment will be high due to too high temperature.

[0033] In some embodiments, the molar ratio of the ammonia gas to the first halosulfonic acid can be 1 to 5:1, specifically, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, etc. Within the above ratio range, the reaction can be sufficiently carried out, which is beneficial to improve the yield of the product.

[0034] In some embodiments, the first halosulfonic acid comprises at least one of fluorosulfonic acid and chlorosulfonic acid. Both of the above halosulfonic acids are superacids, and the S=O bond in the molecule has a strong electron-withdrawing effect, making the S atom positively charged and easily accepting the attack of the nucleophile ammonia, thereby having high reactivity and helping to promote the forward progress of the reaction.

[0035] In some embodiments, ammonia can be introduced into the solvent to obtain a first mixture, and then the first halosulfonic acid is added dropwise into the first mixture in a molar ratio of 1-5:1 of ammonia to the first halosulfonic acid, and reacted at 0-40°C for 3-60 minutes to obtain the ammonium halosulfonate. In other embodiments, ammonia can be introduced into the first halosulfonic acid in a molar ratio of 1-5:1, and reacted at 0-40°C for 3-60 minutes to obtain the ammonium halosulfonate.

[0036] S20: The ammonium halosulfonate is subjected to a second reaction with sulfur trioxide to obtain a halosulfonamide and sulfuric acid.

[0037] In some embodiments, the reaction equation of the second reaction is as follows:

[0038] In the second reaction, sulfur trioxide acts as an electrophile and undergoes an electrophilic substitution reaction with the ammonium halosulfonate, causing the NH4 + loses a proton H + , and at the same time, sulfur trioxide combines with the O atom to ultimately generate a halosulfonamide and sulfuric acid.

[0039] In some embodiments, the temperature of the second reaction is 30-60°C, and can be specifically 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, etc. The above reaction temperature helps the forward progress of the second reaction, and the reaction conditions are mild, the requirements for equipment are low, and industrial production is easy to realize, thereby avoiding problems such as too low temperature affecting the reaction rate and too high temperature requiring high equipment requirements.

[0040] In some embodiments, the time of the second reaction is 1-6 hours, and can be specifically 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, etc. The above reaction time can ensure that the second reaction is complete and does not cause time waste.

[0041] S30: The halosulfonamide is subjected to a third reaction with the sulfur trioxide and a second halosulfonic acid to obtain a bis-halosulfonimide and sulfuric acid.

[0042] In some embodiments, the reaction equation of the third reaction is as follows:

[0043] In the third reaction, the sulfur trioxide first attacks the hydroxyl group in the second halogen sulfonic acid to cause an electrophilic substitution, so that the second halogen sulfonic acid loses the hydroxyl group to become an active sulfonyl group. At this time, the halogen sulfonamide starts to attack the active sulfonyl group to form a bis-halogen sulfonimide. The H + and the sulfur trioxide combine to form a by-product sulfuric acid.

[0044] In some embodiments, the temperature of the third reaction is 30-150°C, and can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc. The above reaction temperature is conducive to the forward progress of the third reaction, and the reaction conditions are relatively mild, the requirement for equipment is low, and industrial production is easy to realize. Thus, the problems of low temperature affecting the reaction rate and high temperature requiring high equipment are avoided.

[0045] In some embodiments, the time of the third reaction is 1-10h, and can be 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, etc. The above reaction time can ensure that the third reaction is complete and time is not wasted.

[0046] In some embodiments, the second reaction and the third reaction can be continuously performed. Specifically, the second reaction and the third reaction can include: mixing the ammonium halogen sulfonate with sulfur trioxide and performing the second reaction to obtain a second mixture, and then adding the second halogen sulfonic acid to the second mixture to perform the third reaction to obtain the bis-halogen sulfonimide and sulfuric acid. Thus, the ammonium halogen sulfonate can react with sulfur trioxide to generate a halogen sulfonamide and sulfuric acid, and the halogen sulfonamide can further react with the halogen sulfonic acid and sulfur trioxide to obtain a halogen sulfonamide and sulfuric acid. The preparation steps are simple, the types of obtained products are few, the products are easy to purify, the by-product sulfuric acid can be recycled and used, the economic benefits are good, no toxic and harmful substances are generated, and the post-processing is simple.

[0047] In some embodiments, the molar ratio of the halogen sulfonamide, the sulfur trioxide and the second halogen sulfonic acid is 1:2:1-2:4:1, and can be 1:2:1, 1:3:1, 1:4:1, 2:2:1, 2:3:1, 2:4:1, etc. The above range is conducive to the full progress of the second reaction and the third reaction, promotes the reaction to proceed in the forward direction, and obtains a bis-halogen sulfonimide with high yield. In addition, the above ratio range can make the second halogen sulfonic acid react as completely as possible, promote the full progress of the reaction, and recycle and use the excess halogen sulfonamide and sulfur trioxide, which is beneficial to saving raw materials and reducing costs.

[0048] In some embodiments, the method further comprises: subjecting the product of the third reaction to vacuum distillation to collect the bis-halosulfinyl compound. By vacuum distillation, sulfuric acid can be removed substantially, and the purity of the bis-halosulfinyl compound can be ≥99%.

[0049] In some embodiments, when the bis-halosulfinyl compound is bis-chlorosulfinyl compound, a fraction of 140℃-180℃ and -0.092MPa--0.098MPa is collected to remove the by-product sulfuric acid, and the bis-chlorosulfinyl compound is obtained. Specifically, the temperature of vacuum distillation can be 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, etc.; and the pressure of vacuum distillation can be -0.092MPa, -0.093MPa, -0.094MPa, -0.095MPa, -0.096MPa, -0.097MPa, -0.098MPa, etc. Under the above conditions, the effect of removing sulfuric acid is better, and the purity of the obtained bis-chlorosulfinyl compound can be ≥99%.

[0050] In some embodiments, when the bis-halosulfinyl compound is bis-chlorofluorosulfinyl compound, a fraction of 80℃-110℃ and -0.092MPa--0.098MPa is collected to remove the by-product sulfuric acid, and the bis-fluorosulfinyl compound is obtained. Specifically, the temperature of vacuum distillation can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, etc.; and the pressure of vacuum distillation can be -0.092MPa, -0.093MPa, -0.094MPa, -0.095MPa, -0.096MPa, -0.097MPa, -0.098MPa, etc. Under the above conditions, the effect of removing sulfuric acid is better, and the purity of the obtained bis-fluorosulfinyl compound can be ≥99%.

[0051] In some embodiments, the removed by-product sulfuric acid can be recycled, thereby saving resources and reducing costs.

[0052] The second aspect of the present application provides a bis-halosulfinyl compound prepared by the method described above. The bis-halosulfinyl compound has high purity and few impurities, can be used for lithiation reaction to prepare bis-halosulfinyl lithium, and can be used as a lithium salt in lithium batteries.

[0053] In some embodiments, the purity of the bis-halosulfinyl compound is ≥99%, and can be 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, 100%, etc. Thus, it can be used for lithiation reaction to prepare bis-halosulfinyl lithium, which can be used as a lithium salt in lithium batteries to improve the overall performance of the battery.

[0054] In a third aspect, the present application provides a method for preparing a bis-halosulfimide salt. According to an embodiment of the present application, the method comprises: preparing a bis-halosulfimide by the method described above; and reacting the bis-halosulfimide with a metal compound to obtain a bis-halosulfimide salt. The method is simple and convenient, and the bis-halosulfimide salt obtained has high purity and good quality, and can be used to prepare a battery.

[0055] According to an embodiment of the present application, the metal compound can comprise at least one of an alkali metal halide, an alkali metal hydroxide, and an alkali metal carbonate. Thus, the salt formation reaction condition is mild, the reaction proceeds smoothly, and the product yield is high.

[0056] As an example, the metal compound can comprise lithium fluoride. The bis-halosulfimide can react with the lithium fluoride to obtain a lithium bis-halosulfimide.

[0057] Embodiments of the present application are described in detail below.

[0058] Example 1 A three-necked flask was charged with 500 g of acetonitrile, and 1.05 mol of ammonia gas was dissolved therein. 1 mol of chlorosulfonic acid was slowly added dropwise while controlling the reaction temperature at 20°C. After the gas was passed, the reaction was continued for 45 min. Filtration and drying were performed to obtain an ammonium chlorosulfonate solid, with a yield of 92.6%.

[0059] The above-obtained ammonium chlorosulfonate solid was added to 2 mol of sulfur trioxide, and the reaction was performed at a temperature of 45°C for 3 h. 1 mol of chlorosulfonic acid was further added dropwise to the above-obtained reaction solution, and the reaction was performed at a temperature of 90°C for 5 h. Vacuum distillation was performed to collect a fraction at 160°C and -0.095 MPa, to obtain a bis-chlorosulfimide with a purity of ≥99%.

[0060] Examples 2-35 The same method as in Example 1 was used, and the specific parameters are shown in Table 1.

[0061] Comparative Example 1 Sulfur trioxide and ammonia gas were reacted in a high-pressure reaction kettle to obtain imino disulfonic acid; Dichlorosulfoxide and the obtained imino disulfonic acid were further reacted, and vacuum distillation was performed to obtain bis-chlorosulfimide. The purity of the obtained bis-chlorosulfimide was 78.5%, and the yield was 42.6%.

[0062] The specific reaction equation is as follows:

[0063] Performance detection: 1. Bis-halosulfimide structure test: Raman spectrum and nuclear magnetic resonance test. The Raman spectrum of the bis-chlorosulfimide obtained in the example is shown in FIG. 1. The Raman spectrum of the bis-chlorosulfimide obtained in the example is shown in FIG. 1.Figure 1 The nuclear magnetic F spectrum is shown in Figure 1. Figure 2 It can be seen that the target product bischlorosulfonyl imide is obtained. Figure 1 It can be seen that the target product bischlorosulfonyl imide is obtained. Figure 2

[0064] 2. Bis-halosulfonyl imide yield: Yield = 2 x molar mass of halosulfonic acid x mass of product / (amount of halosulfonic acid charged x molar mass of bis-halosulfonyl imide) x 100%.

[0065] 3. Bis-halosulfonyl imide purity: 3-1. Bis-chlorosulfonyl imide purity analysis: First step, determination of nitrogen content in bis-chlorosulfonyl imide: A certain amount of bis-chlorosulfonyl imide is weighed and hydrolyzed with water, a certain volume of nitric acid is added to the hydrolyzed solution, and water is added to constant volume. Titration is performed with sodium nitrite solution, starch potassium iodide test paper is used as an external indicator, and the titration end point is reached when purple spots appear on the test paper. The volume of sodium nitrite solution consumed is recorded, and the calculation formula is as follows: Formula 1 In formula 1, n(N): nitrogen content in bis-chlorosulfonyl imide, mol / g; c1: concentration of sodium nitrite solution, mol / L; V1: volume of sodium nitrite solution consumed, mL; m1: sample weight of bis-chlorosulfonyl imide, g; Second step, determination of chlorine content in bis-chlorosulfonyl imide: A certain amount of bis-chlorosulfonyl imide is taken in a sodium hydroxide solution containing ice water, heated and boiled on an electric stove for a period of time, acidified with nitric acid, and titrated with silver nitrate solution as the titrant using potentiometric titration to obtain the chlorine ion content. The present application uses silver nitrate solution as the titrant and obtains the chlorine ion content by potentiometric titration, which is a known technology. The specific operation process and principle are known in the art and will not be described here. The calculation formula of chlorine ion content is as follows: Formula 2 In formula 2, n(Cl): chlorine content in bis-chlorosulfonyl imide, mol / g; c2: concentration of silver nitrate solution, mol / L; V2: volume of silver nitrate solution consumed, mL; m2: sample weight of bis-chlorosulfonyl imide, g; Third step, calculation of bis-chlorosulfonyl imide purity: (1) If The purity of bis-chlorosulfonyl imide is calculated according to the nitrogen content, and the formula is as follows:​ Formula 3 In formula 3: w1: the purity of bis-chlorosulfonyl imide calculated according to the nitrogen content, %; c1: the concentration of sodium nitrite solution, mol / L; V1: the volume of consumed sodium nitrite solution, mL; m1: the sample weight of bis-chlorosulfonyl imide, g; M: the numerical value of the molar mass of bis-chlorosulfonyl imide, g / mol (M = 214.03); (2) If , the purity of bis-chlorosulfonyl imide is calculated according to the chlorine content, and the formula is as follows: Formula 4 In formula 4: w2: the purity of bis-chlorosulfonyl imide calculated according to the chlorine content, %; c2: the concentration of silver nitrate solution, mol / L; V2: the volume of consumed silver nitrate solution, mL; m2: the sample weight, g; M: the numerical value of the molar mass of bis-chlorosulfonyl imide, g / mol (M = 214.03). 3-2, Bis-fluorosulfonyl imide purity analysis: First step, determination of free fluoride ion content: After adding a certain amount of ice water to a polytetrafluoroethylene beaker, adding the sample bis-fluorosulfonyl imide, through the bis-fluorosulfonyl imide not decomposed in ice water, the free fluoride ion can be accurately determined, the free fluoride ion (w 11 ) is determined by ion chromatography; Second step, determination of fluoride ion content after hydrolysis: A certain amount of ice water and sodium hydroxide solution is added to a platinum gold crucible, and a certain amount of bis-fluorosulfonyl imide is added, then the platinum gold crucible is placed in a constant temperature water bath heater for heating and hydrolysis, the heating temperature of the constant temperature water bath heater is 80-95℃, and then the sample is washed into a polytetrafluoroethylene bottle and diluted with water to constant volume. The fluoride ion content (w 21 ) after hydrolysis is determined by ion chromatography; Third step, calculation of bis-fluorosulfonyl imide purity: The purity of bis-fluorosulfonyl imide is calculated by the difference between the fluoride ion content after complete hydrolysis and the free fluoride ion content. The specific calculation formula is as follows: the content of sample bis-fluorosulfonyl imide (w3) is expressed by % and calculated according to the following formula: Formula 5 In formula 5: w3: the purity of bis-fluorosulfonyl imide, %; w 21: content of fluoride ion after hydrolysis, ppm; w 11 : content of free fluoride ion, ppm; 9.0574: ratio of mass fraction of bisfluorosulfonylimide to mass fraction of fluoride ion. The ice water in the above first step and second step is high-purity water with conductivity of 18.25 us / cm and ice frozen from high-purity water, and the temperature of the ice water is 0-7℃.

[0066] Table 1

[0067] From the data in Table 1, it can be seen that the purity and yield of bis-halosulfonylimide prepared by the method of the present application are obviously improved, and the reaction condition is mild and easy to scale up.

[0068] In the description of the present application, it should be understood that the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0069] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present description, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the different embodiments or examples described in the present description and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0070] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method of synthesizing a bis-halogenosulfimide, characterized by, The method comprises: carrying out a first reaction of ammonia gas with a first halosulfonic acid to obtain a halosulfonic acid ammonium salt; carrying out a second reaction of the halosulfonic acid ammonium salt with sulfur trioxide to obtain a halosulfonamide; carrying out a third reaction of the halosulfonamide with the sulfur trioxide and a second halosulfonic acid to obtain a bis-halosulfonimide and sulfuric acid.

2. The method of synthesizing bis-halogen sulfoximines according to claim 1, wherein, The first reaction of the ammonia gas with the first halosulfonic acid comprises any one of the following: passing the ammonia gas into a solvent to obtain a first mixture; adding the first halosulfonic acid into the first mixture and continuously reacting for a predetermined time to obtain the halosulfonic acid ammonium salt; passing the ammonia gas into the first halosulfonic acid and continuously reacting for the predetermined time to obtain the halosulfonic acid ammonium salt.

3. The method of synthesizing bis-halogen sulfoximines according to claim 2, wherein, At least one of the following conditions is met: the predetermined time is 3 min to 60 min; the temperature of the first reaction is 0°C to 40°C; the molar ratio of the ammonia gas to the first halosulfonic acid is 1 to 5:1; the first halosulfonic acid is added dropwise into the first mixture; the solvent comprises at least one of acetonitrile, dichloromethane, dichloroethane, dimethyl carbonate, and methyl ethyl carbonate.

4. The method of synthesizing bis-halogen sulfoximines according to claim 1, wherein, The first halosulfonic acid and the second halosulfonic acid comprise at least one of fluorosulfonic acid and chlorosulfonic acid.

5. The method of synthesizing bis-halogen sulfoximines according to claim 1, wherein, The second reaction and the third reaction comprise: mixing the halosulfonic acid ammonium salt with sulfur trioxide and carrying out the second reaction to obtain a second mixture; adding the second halosulfonic acid into the second mixture and carrying out the third reaction to obtain the bis-halosulfonimide and sulfuric acid.

6. The method of synthesizing bis-halogen sulfoximines according to claim 5, wherein, At least one of the following conditions is met: the temperature of the second reaction is 30°C to 60°C; the time of the second reaction is 1 h to 6 h; the temperature of the third reaction is 30°C to 150°C; the time of the third reaction is 1 h to 10 h; the molar ratio of the halosulfonic acid ammonium salt, the sulfur trioxide, and the second halosulfonic acid is 1:2:1 to 2:4:

1.

7. The method of synthesizing bis-halogen sulfoximines according to claim 1, wherein, Further comprising: carrying out vacuum distillation on the product of the third reaction to obtain the bis-halosulfonimide.

8. The method of synthesizing bis-halogen sulfoximines according to claim 7, wherein, when the bis-halosulfonimide is bis-chlorosulfonimide, collecting a fraction of 140°C to 180°C at -0.092 MPa to -0.098 MPa to obtain the bis-chlorosulfonimide; when the bis-halosulfonimide is bis-fluorosulfonimide, collecting a fraction of 80°C to 110°C at -0.092 MPa to -0.098 MPa to obtain the bis-fluorosulfonimide.

9. A bis-halogenosulfimide characterized in that, The bis-halosulfonimide is prepared by the method of any one of claims 1 to 8.

10. A method of preparing a bis-halogenosulfimide salt, characterized in that, The method comprises: preparing a bis-halosulfonimide by the method of any one of claims 1 to 8; carrying out a salt formation reaction of the bis-halosulfonimide with a metal compound to obtain a bis-halosulfonimide salt.

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