Bis-halosulfimines, methods for their preparation, methods for preparing bis-halosulfimine salts

Abstract

The application belongs to the technical field of lithium battery materials, and discloses a dihalogen sulfoximine, a preparation method thereof, and a method for preparing a dihalogen sulfoximine salt. The preparation method comprises the following steps: performing a first reaction on ammonia and a first halogen sulfonic acid to obtain an ammonium halogen sulfonate; performing a second reaction on the ammonium halogen sulfonate and sulfur trioxide to obtain a halogen sulfonamide; and performing a third reaction on the halogen sulfonamide, the sulfur trioxide and a second halogen sulfonic acid to obtain a dihalogen sulfoximine and sulfuric acid. The preparation method is simple and environmentally friendly, the product is easy to purify, the by-product is only sulfuric acid and can be recycled, and the dihalogen sulfoximine prepared has high 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, which can be recycled, and 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:

[0008] 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 continuing to react 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.

[0009] 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 continuing to react 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.

[0010] In some embodiments, the method for synthesizing bis-halogen sulfonylimide satisfies at least one of the following conditions:

[0011] The predetermined time is 3 min to 60 min;

[0012] The temperature of the first reaction is 0°C to 40°C;

[0013] The molar ratio of the ammonia gas to the ammonium halogen sulfonate is 1-5:1;

[0014] The first halogen sulfonic acid is added dropwise to the first mixture;

[0015] The solvent includes at least one of acetonitrile, dichloromethane, dichloroethane, dimethyl carbonate, and methyl ethyl carbonate.

[0016] 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.

[0017] In some embodiments, the first halosulfonic acid and the second halosulfonic acid comprise at least one of fluorosulfonic acid and chlorosulfonic acid. Both of the above halosulfonic acids are superacids, and have high reactivity, which helps to promote the forward progress of the reaction.

[0018] In some embodiments, the second reaction and the third reaction comprise: mixing the ammonium halosulfonate salt with sulfur trioxide to perform a second reaction to obtain a second mixture; adding the second halosulfonic acid to the second mixture to perform a third reaction to obtain the bis-halosulfonyl imide and sulfuric acid. In this way, the ammonium halosulfonate salt 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. This method has simple preparation steps, fewer types of products, easy purification, and good economic benefits. In addition, no toxic and harmful substances are generated, and the post-processing is simple.

[0019] In some embodiments, the method for synthesizing bis-halosulfonyl imide satisfies at least one of the following conditions:

[0020] The temperature of the second reaction is 30-60°C;

[0021] The time of the second reaction is 1-6h;

[0022] The temperature of the third reaction is 30-150°C;

[0023] The time of the third reaction is 1-10h;

[0024] The molar ratio of the ammonium halosulfonate salt, the sulfur trioxide, and the second halosulfonic acid is 1:2:1-2:4:1.

[0025] 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.

[0026] In some embodiments, the method for synthesizing 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.

[0027] In some embodiments, when the bis-halosulfonyl imide is bis-chlorosulfonyl imide, the fraction of 140-180°C and -0.092-0.098 MPa is collected to obtain bis-chlorosulfonyl imide.

[0028] In some embodiments, when the bis-halosulfonyl imide is bis-fluorosulfonyl imide, the fraction of 80-110°C and -0.092-0.098 MPa is collected to obtain bis-fluorosulfonyl imide.

[0029] The second aspect of the present application provides a bis-halosulfimide prepared by the method for preparing bis-halosulfimide described above. The bis-halosulfimide has high purity and few impurities, can be used for lithiumation reaction to prepare bis-fluorosulfimide lithium, and can be used as a lithium salt in a lithium battery.

[0030] The third aspect of 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 performing a salt reaction between the bis-halosulfimide and 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 for preparing a battery. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a Raman spectrum of the bis-chlorosulfimide prepared in Example 1 of the present application;

[0032] Figure 2 is a nuclear magnetic F spectrum of the bis-chlorosulfimide prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0033] 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.

[0034] The present application is based on the following findings and recognitions of the inventors:

[0035] As described above, the method for preparing 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 thionyl chloride 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 bis-halosulfimide, which has simple preparation method, few by-products, can be resource utilization, and the obtained product has high purity and the preparation process is environmentally friendly.

[0036] The first aspect of the present application provides a method for synthesizing bis-halosulfimide, comprising the following steps:

[0037] S10: performing a first reaction between ammonia and a first halosulfonic acid to obtain an ammonium halosulfonate.

[0038] In this step, the equation for the reaction between ammonia and the first halosulfonic acid is as follows. In the molecule of the first halosulfonic acid, the strong electron-withdrawing property of the S=O bond makes the S atom carry a positive charge, which is easy to be attacked by the nucleophile ammonia, to obtain an ammonium halosulfonate, which is helpful to quickly build a nitrogen-containing skeleton.

[0039]

[0040] wherein X = F or CI.

[0041] 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.

[0042] 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 above solvent can dissolve the first halosulfonic acid and ammonia gas, can form a homogeneous reaction system, and can promote the forward progress of the reaction. At the same time, the above solvent has stable chemical properties and is not prone to side reactions with ammonia gas and the first halosulfonic acid. In addition, the above solvent can isolate the moisture in the system and prevent the hydrolysis of the first halosulfonic acid and the decomposition of the product.

[0043] In some embodiments, the specific manner 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 improving the yield of the product.

[0044] 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 ammonia gas can be directly introduced into the first halosulfonic acid for reaction without the need for a solvent, which is more convenient to operate.

[0045] In some embodiments, the above predetermined time can be 3 min to 60 min, and specific examples include 3 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, and 60 min. Within the above time range, the reaction can be sufficiently carried out, which is beneficial to improving the yield of the product. The yield will not be reduced due to too short a time, and the time will not be wasted due to too long a time.

[0046] In some embodiments, the temperature of the first reaction is 0°C to 40°C, and specific examples include 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, and 40°C. 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 industrialized production is easy to achieve. The reaction speed will not be too slow due to too low a temperature, and the reactants will not be decomposed, the side reactions will not be increased, or the requirement for equipment will not be high due to too high a temperature.

[0047] In some embodiments, the molar ratio of the ammonia gas to the first halogen sulfonic acid can be 1-5:1, and specifically can be 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 conducive to improving the yield of the product.

[0048] In some embodiments, the first halogen sulfonic acid includes at least one of fluorosulfonic acid and chlorosulfonic acid. Both of the above halogen sulfonic acids are superacids, and the S=O bond in the molecule has a strong electron-withdrawing effect, which makes the S atom positively charged and easy to accept the attack of the nucleophile ammonia gas. Thus, the reaction activity is high, which is conducive to promoting the forward reaction.

[0049] In some embodiments, the ammonia gas can be introduced into the solvent to obtain a first mixture, and then the first halogen sulfonic acid is added dropwise into the first mixture according to a molar ratio of 1-5:1 of the ammonia gas to the first halogen sulfonic acid, and the reaction is carried out at 0-40°C for 3 min-60 min to obtain the ammonium halogen sulfonate. In other embodiments, the ammonia gas can be introduced into the first halogen sulfonic acid according to a molar ratio of 1-5:1, and the reaction is carried out at 0-40°C for 3 min-60 min to obtain the ammonium halogen sulfonate.

[0050] S20: The second reaction is carried out between the ammonium halogen sulfonate and sulfur trioxide to obtain a halogen sulfonamide and sulfuric acid.

[0051] In some embodiments, the reaction equation of the second reaction is as follows:

[0052]

[0053] In the second reaction, sulfur trioxide acts as an electrophile and undergoes an electrophilic substitution reaction with the ammonium halogen sulfonate, so that the NH4+ in the ammonium halogen sulfonate loses a proton H + + At the same time, sulfur trioxide is combined with the O atom, and finally the halogen sulfonamide and sulfuric acid are generated.

[0054] In some embodiments, the temperature of the second reaction is 30-60°C, and specifically can be 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, etc. The above reaction temperature is conducive to the forward reaction of the second reaction, and the reaction condition is mild, the requirement for equipment is low, and industrial production is easy to realize. Thus, the problems of too low temperature affecting the reaction rate and too high temperature requiring high equipment are avoided.

[0055] In some embodiments, the time of the second reaction is 1-6h, and specifically can be 1h, 2h, 3h, 4h, 5h, 6h, etc. The above reaction time can ensure that the second reaction is completely carried out, and time waste is avoided.

[0056] ​S30: subjecting the halosulfamide to a third reaction with the sulfur trioxide and the second halosulfonic acid to obtain a bis-halosulfonylimide and sulfuric acid.

[0057] In some embodiments, the reaction equation of the third reaction is as follows:

[0058]

[0059] In the third reaction, the sulfur trioxide first attacks the hydroxyl group in the second halosulfonic acid, an electrophilic substitution occurs, the hydroxyl group in the second halosulfonic acid is lost to become an active sulfonyl group, at this time the halosulfamide starts to attack the active sulfonyl group to form a bis-halosulfonylimide, and H + and the sulfur trioxide combine to form a by-product sulfuric acid.

[0060] 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. Therefore, problems such as too low temperature affecting the reaction rate and too high temperature requiring high equipment are not caused.

[0061] 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 completely performed, and time is not wasted.

[0062] 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 halosulfonate with the sulfur trioxide and performing the second reaction to obtain a second mixture, and then adding the second halosulfonic acid to the second mixture to perform the third reaction to obtain the bis-halosulfonylimide and the sulfuric acid. Therefore, the ammonium halosulfonate can react with the sulfur trioxide to generate the halosulfamide and the sulfuric acid, and the halosulfamide can further react with the halosulfonic acid and the sulfur trioxide to obtain the halosulfonylimide and the sulfuric acid. Not only is the preparation step simple, the types of obtained products are few, the product is easy to purify, the by-product sulfuric acid can be recycled, the economic benefit is good, and no toxic and harmful substances are generated, and the post-treatment is simple.

[0063] In some embodiments, the molar ratio of the halosulfonamide, the sulfur trioxide and the second halosulfonic 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 higher yield of the bis-halosulfonamide. Moreover, the above ratio range can make the second halosulfonic acid as complete as possible, while promoting the full progress of the reaction, and the excess halosulfonamide and sulfur trioxide can be recycled and used, which is conducive to saving raw materials and reducing costs.

[0064] In some embodiments, the method further comprises: performing vacuum distillation on the product of the third reaction to obtain the bis-halosulfonamide. After vacuum distillation, sulfuric acid can be substantially removed, and bis-halosulfonamide with a purity of ≥99% can be obtained.

[0065] In some embodiments, when the bis-halosulfonamide is bis-chlorosulfonamide, a fraction of 140-180°C and -0.092-0.098 MPa is collected to remove the by-product sulfuric acid and obtain bis-chlorosulfonamide. Specifically, the temperature of vacuum distillation can be 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, etc.; and the pressure of vacuum distillation can be -0.092 MPa, -0.093 MPa, -0.094 MPa, -0.095 MPa, -0.096 MPa, -0.097 MPa, -0.098 MPa, etc. Under the above conditions, the effect of removing sulfuric acid is better, and the purity of the obtained bis-chlorosulfonamide can be ≥99%.

[0066] In some embodiments, when the bis-halosulfonamide is bis-chlorofluorosulfonamide, a fraction of 80-110°C and -0.092-0.098 MPa is collected to remove the by-product sulfuric acid and obtain bis-fluorosulfonamide. Specifically, the temperature of vacuum distillation can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, etc.; and the pressure of vacuum distillation can be -0.092 MPa, -0.093 MPa, -0.094 MPa, -0.095 MPa, -0.096 MPa, -0.097 MPa, -0.098 MPa, etc. Under the above conditions, the effect of removing sulfuric acid is better, and the purity of the obtained bis-fluorosulfonamide can be ≥99%.

[0067] In some embodiments, the removed by-product sulfuric acid can be recycled, thereby saving resources and reducing costs.

[0068] The second aspect of the present application provides a bis-halosulfonimidate prepared by the method for preparing bis-halosulfonimidate described above. The bis-halosulfonimidate has high purity and few impurities, can be used for a lithiation reaction to prepare bis-halosulfonimidate lithium, and can be used as a lithium salt in a lithium battery.

[0069] In some embodiments, the purity of the bis-halosulfonimidate 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, the bis-halosulfonimidate can be used for a lithiation reaction to prepare bis-halosulfonimidate lithium, which can be used as a lithium salt in a lithium battery, and can improve the comprehensive performance of the battery.

[0070] The third aspect of the present application provides a method for preparing a bis-halosulfonimidate salt. According to the embodiments of the present application, the method comprises: preparing a bis-halosulfonimidate by the method described above; and performing a salt formation reaction between the bis-halosulfonimidate and a metal compound to obtain a bis-halosulfonimidate salt. The method is simple and convenient to operate, and the obtained bis-halosulfonimidate salt has high purity and good quality, and can be used for preparing a battery.

[0071] According to the embodiments of the present application, the metal compound can include at least one of an alkali metal halide, an alkali metal hydroxide, and an alkali metal carbonate. Thus, the salt formation reaction conditions are mild, the reaction proceeds smoothly, and the yield of the product is high.

[0072] As an example, the metal compound can include lithium fluoride. The bis-halosulfonimidate can react with the lithium fluoride to obtain bis-halosulfonimidate lithium.

[0073] The embodiments of the present application are described in detail below.

[0074] Embodiment 1

[0075] 500 g of acetonitrile was added to a three-necked flask, 1.05 mol of ammonia gas was dissolved by bubbling, and 1 mol of chlorosulfonic acid was slowly added dropwise while controlling the reaction temperature to be 20°C. After the bubbling was completed, the reaction was continued for 45 min, and then filtration and drying were performed to obtain ammonium chlorosulfonate solid, with a yield of 92.6%.

[0076] The above-mentioned ammonium chlorosulfonate solid was added to 2 mol of sulfur trioxide, and the reaction was performed at a reaction temperature of 45°C for 3 h. Then, 1 mol of chlorosulfonic acid was continuously added dropwise to the obtained reaction solution, and the reaction was performed at a reaction temperature of 90°C for 5 h. Finally, vacuum distillation was performed, and the fraction collected at 160°C and -0.095 MPa was obtained to obtain bis-chlorosulfonimidate with a purity of ≥ 99%.

[0077] Embodiments 2-35

[0078] The method was the same as that in Embodiment 1, and the specific parameters were different, as shown in Table 1.

[0079] Comparative Example 1

[0080] Sulfur trioxide and ammonia gas were reacted in a high-pressure reactor to obtain imino disulfonic acid;

[0081] Dichlorosulfoxide was then reacted with the obtained imino disulfonic acid, and the product was distilled under reduced pressure to obtain bischlorosulfonylimide.

[0082] The purity of the obtained bischlorosulfonylimide was 78.5%, and the yield was 42.6%.

[0083] The specific reaction equation is as follows:

[0084]

[0085] Performance detection:

[0086] 1. Bis-halosulfonylimide structure test: Raman spectrum and nuclear magnetic resonance test. The Raman spectrum of the bischlorosulfonylimide obtained in the example is shown in

[0087] , and the nuclear magnetic F spectrum is shown in Figure 1 . As can be seen from Figure 2 and Figure 1 , the target product bischlorosulfonylimide is obtained. Figure 2

[0088] 2. Bis-halosulfonylimide yield:

[0089] Yield = 2 x molar mass of halosulfonic acid x mass of product / (amount of halosulfonic acid charged x molar mass of bis-halosulfonylimide) x 100%.

[0090] 3. Bis-halosulfonylimide purity:

[0091] 3-1. Purity analysis of bischlorosulfonylimide:

[0092] First step, determination of nitrogen content in bischlorosulfonylimide:

[0093] A certain amount of bischlorosulfonylimide was weighed and hydrolyzed with water, a certain volume of nitric acid was added to the hydrolyzed solution, and water was added to constant volume. Titration was performed with sodium nitrite solution, starch potassium iodide test paper was used as an external indicator, and the titration end point was reached when purple spots appeared on the test paper. The volume of sodium nitrite solution consumed was recorded, and the calculation formula was as follows:

[0094] Formula 1

[0095] In formula 1, n(N): nitrogen content in bischlorosulfonylimide, mol / g;

[0096] c1: concentration of sodium nitrite solution, mol / L;

[0097] V1: volume of sodium nitrite solution consumed, mL;​

[0098] m1: the sample weight of the bischlorosulfonamide, g;

[0099] Second step, determination of the chlorine content in the bischlorosulfonamide:

[0100] A certain amount of bischlorosulfonamide 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 a silver nitrate solution as the titrant to obtain the chlorine ion content by potentiometric titration (the present application uses a silver nitrate solution as the titrant to obtain the chlorine ion content by potentiometric titration, which is a known technology, and its specific operation process and principle are known, and will not be described here).

[0101] The calculation formula of the chlorine ion content is as follows:

[0102] Formula 2

[0103] In formula 2, n(Cl): chlorine content in bischlorosulfonamide, mol / g;

[0104] c2: concentration of silver nitrate solution, mol / L;

[0105] V2: volume of consumed silver nitrate solution, mL;

[0106] m2: the sample weight of the bischlorosulfonamide, g;

[0107] Third step, calculation of the purity of bischlorosulfonamide:

[0108] (1) If , the purity of bischlorosulfonamide is calculated according to the nitrogen content, and the formula is as follows:

[0109] Formula 3

[0110] In formula 3, w1: the purity of bischlorosulfonamide calculated according to the nitrogen content, %;

[0111] c1: concentration of sodium nitrite solution, mol / L;

[0112] V1: volume of consumed sodium nitrite solution, mL;

[0113] m1: the sample weight of the bischlorosulfonamide, g;

[0114] M: the numerical value of the molar mass of bischlorosulfonamide, g / mol (M = 214.03);

[0115] (2) If , the purity of bischlorosulfonamide is calculated according to the chlorine content, and the formula is as follows:

[0116] Formula 4

[0117] In formula 4: w2: the purity of bis-chlorosulfonyl imide calculated according to the chlorine content, %;

[0118] c2: the concentration of silver nitrate solution, mol / L;

[0119] V2: the volume of consumed silver nitrate solution, mL;

[0120] m2: the sample weighing amount, g;

[0121] M: the numerical value of the molar mass of bis-chlorosulfonyl imide, g / mol (M = 214.03).

[0122] 3-2, bis-fluorosulfonyl imide purity analysis:

[0123] Step 1, determination of free fluoride ion content:

[0124] A certain amount of ice water is added to a polytetrafluoroethylene beaker, then the sample bis-fluorosulfonyl imide is added. The bis-fluorosulfonyl imide does not decompose in ice water, which can accurately determine the free fluoride ion, and the free fluoride ion (w 11 ) is determined by ion chromatography;

[0125] Step 2, determination of fluoride ion content after hydrolysis:

[0126] A certain amount of ice water and sodium hydroxide solution is added to a platinum gold crucible, then a certain amount of bis-fluorosulfonyl imide is added, and then the platinum gold crucible is placed in a constant temperature water bath oven for heating and hydrolysis. The heating temperature of the constant temperature water bath oven is 80-95℃, and then it is taken out and cooled. 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;

[0127] Step 3, calculation of bis-fluorosulfonyl imide purity:

[0128] 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 sample bis-fluorosulfonyl imide content (w3) is expressed by % and calculated according to the following formula:

[0129] Formula 5

[0130] In formula 5: w3: the purity of bis-fluorosulfonyl imide, %;

[0131] w 21 : the content of fluoride ion after hydrolysis, ppm;

[0132] w 11 : the content of free fluoride ion, ppm;

[0133] 9.0574: ratio of mass fraction of bisfluorosulfonylimide to mass fraction of fluoride ion.

[0134] 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℃.

[0135] Table 1

[0136]

[0137] 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 conditions are mild and easy to scale up.

[0138] In the description of the present application, it should be understood that the terms "first", "second" are 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.

[0139] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like 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 skilled in the art can combine and combine the different embodiments or examples described in the present description and the features of the different embodiments or examples without contradiction.

[0140] 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 and a first halosulfonic acid to obtain a halosulfonic acid ammonium salt; carrying out a second reaction of the halosulfonic acid ammonium salt and sulfur trioxide to obtain a halosulfonamide; carrying out a third reaction of the halosulfonamide, the sulfur trioxide and a second halosulfonic acid to obtain a bis-halosulfonimide and sulfuric acid; wherein the first halosulfonic acid and the second halosulfonic acid comprise at least one of fluorosulfonic acid and chlorosulfonic acid.

2. The method of synthesizing bis-halogen sulfoximines according to claim 1, wherein, The first reaction of the ammonia gas and 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 ℃ to 40 ℃; 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 second reaction and the third reaction comprise: mixing the halosulfonic acid ammonium salt and 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.

5. The method of synthesizing bis-halogen sulfoximines according to claim 4, wherein, At least one of the following conditions is met: the temperature of the second reaction is 30 ℃ to 60 ℃; the time of the second reaction is 1 h to 6 h; the temperature of the third reaction is 30 ℃ to 150 ℃; 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.

6. 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.

7. The method of synthesizing bis-halogen sulfoximines according to claim 6, wherein, when the bis-halosulfonimide is bis-chlorosulfonimide, collecting a fraction of 140 ℃ to 180 ℃ and -0.092 MPa to -0.098 MPa to obtain the bis-chlorosulfonimide; when the bis-halosulfonimide is bis-fluorosulfonimide, collecting a fraction of 80 ℃ to 110 ℃ and -0.092 MPa to -0.098 MPa to obtain the bis-fluorosulfonimide.

8. A process for the preparation of a bis-halogenosulfimide salt, characterized in that, The method comprises: preparing the bis-halosulfonimide by the method according to any one of claims 1 to 7; carrying out a salt formation reaction of the bis-halosulfonimide and a metal compound to obtain a bis-halosulfonimide salt.

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