Method for producing lithium bis(fluorosulfonyl)imide, method and method for producing bis(chlorosulfonyl)imide

Abstract

Lithium bis(fluorosulfonyl)imide and its preparation method and use, in which iminodisulfonic acid is synthesized using sulfur trioxide and ammonia as raw materials, iminodisulfonic acid is chlorinated with dichlorosulfoxide to obtain bischlorosulfonylimide, and then fluorinated and lithiumated to obtain lithium bis(fluorosulfonyl)imide. This method has excellent yield and purity, and compared with conventional processes, it has advantages such as simple raw materials, less waste liquid, waste gas and solid waste, environmental friendliness, fewer side reactions, low cost, etc., and is easy to industrialize.

Description

Technical Field

[0001] The present invention belongs to the field of chemical synthesis technology, and specifically relates to lithium bis(fluorosulfonyl)imide, its manufacturing method, and uses.

Background Art

[0002] In recent years, driven by products such as smartphones, mobile power supplies, and tablet PCs, the production value of the domestic lithium battery industry has been continuously increasing. At the same time, the applications of lithium-ion batteries are not limited to electronic consumer products. The two new application directions of power and energy storage have brought infinite market space to lithium batteries. Also, with the expansion of its application fields, the requirements for further improving battery characteristics are increasing. The currently most widely used electrolyte lithium salt is lithium hexafluorophosphate. Despite its excellent comprehensive performance, due to its own drawbacks such as instability, easy water absorption, short lifespan, and poor low-temperature performance, it is insufficient to meet the increasingly expanding application requirements of lithium-ion batteries.

[0003] Compared with lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide (LiFSI) has better thermal stability, chemical stability, higher conductivity, and lower corrosion rate, and has the potential to replace lithium hexafluorophosphate. It is considered to be a new generation of lithium salt and can be widely applied to lithium batteries and supercapacitors. As a lithium-ion secondary battery electrolyte, it is necessary to meet strict requirements such as high purity and anhydrous. After the introduction of moisture, it was difficult to completely remove it until it decomposed by the entrainment of water due to temperature rise and the removal of water by drying. Conventionally, when generating bis ( chlorosulfonyl ) imide, strong corrosive raw materials such as chlorosulfonic acid, sulfamic acid, and dichlorosulfoxide are often used to synthesize bis ( chlorosulfonyl ) imide, which has a low yield, many impurities, and a large impact on the environment.

[0004] Patent Document 1 discloses that a sulfonamide is reacted with thionyl dichloride and chlorosulfonic acid to obtain bis ( chlorosulfonyl ) imide, and then it is reacted with antimony trifluoride and potassium carbonate (cesium or rubidium) to obtain bis ( fluorosulfonyl ) imide potassium (cesium or rubidium), and finally bis ( fluorosulfonyl ) imide potassium (cesium or rubidium) and lithium perchlorate or lithium tetrafluoroborate are subjected to a metathesis reaction to obtain lithium bis(fluorosulfonyl)imide. However, the process is complex and the yield is low.

[0005] Patent Document 2 discloses a method for producing lithium bis(fluorosulfonyl)imide or sodium bis(fluorosulfonyl)imide, in which sulfamic acid and halosulfonic acid are reacted with triethylamine to generate bis(sulfonyl)imide, then potassium hydroxide is added to generate potassium bis(sulfonyl)imide tri-salt, then oxalyl chloride is added to generate potassium bis(chlorosulfonyl)imide, and finally hydrogen fluoride is added to obtain golden bis(fluorosulfonyl)imide. The process is relatively complex and no data regarding the yield and purity are provided.

[0006] Patent Document 3 discloses a method for producing a potassium salt of fluorosulfonylimide, in which chlorosulfonic acid is reacted with ammonia to generate imi Do disulfonic acid, which is fluorinated with nitrosyl fluoride to generate bis ( fluorosulfonyl ) imide, and then lithium hydroxide is added to generate lithium bis(fluorosulfonyl)imide. However, nitrosyl fluoride is unstable and it is necessary to use a toluene solvent, etc. When lithium hydroxide is employed in the lithiation process, water is generated and the purity of the reaction product is low.

[0007] Patent Document 4 discloses that urea is reacted with fluorosulfonic acid to produce bis ( fluorosulfonyl ) imide, and then lithiated to obtain lithium bis(fluorosulfonyl)imide. All operations also need to be carried out in a hydrofluoric acid-resistant device, resulting in high equipment investment and high operation risks.

[0008] Patent Document 5 discloses that cyanogen chloride and sulfur trioxide are used to produce chlorosulfonic acid isocyanate, and then reacted with chlorosulfonic acid to produce bis ( chlorosulfonyl ) imide. Cyanogen chloride is a highly toxic gas and has a great impact on the safety environment.

[0009] Patent Document 6 uses SO 2 F 2 and NH 3 as raw materials, tetramethylpropylenediamine (TMPDA) as a base, acetonitrile as a solvent, and reacts at 10 - 15 °C. After the reaction, the low-boiling liquid is separated under reduced pressure, and the viscous product is dissolved in methanol at 30 °C. Then, an aqueous solution of tetrabutylammonium bromide is added dropwise to the methanol solution in an amount of 1 equivalent. As a result, a white solid precipitates. After filtration, tetrabutylammonium bis ( fluorosulfonyl ) imide metal salt with a yield of 84.4% is obtained. SO 2 F 2 is highly toxic, completely colorless and odorless, and significant preventive measures must be taken.

[0010] Patent Document 7 discloses that SO 2 F 2 , ammonia and 6-fold equivalent of fluorosalt are heated to 60 °C for reaction to directly produce bis ( fluorosulfonyl ) imide metal salt. Similarly, SO 2 F 2 is highly toxic, completely colorless and odorless, and significant preventive measures must be taken.

[0011] Patent Document 8 discloses that when the molar ratio of SO 2 F 2 , NH 3 and Et 3 N is 2:1:3, using acetonitrile as a solvent, and under an ice-water bath, triethylamine bis ( fluorosulfonyl ) imide metal salt and a small amount of by-products can be obtained. By slowly adding various metal hydroxides to the triethylamine bis ( fluorosulfonyl ) imide metal salt solution and removing triethylamine, the product bis ( fluorosulfonyl ) imide metal salt can be obtained. Using inexpensive raw materials such as SO 2 F 2 , NH 3 and Et 3 N, bis ( fluorosulfonyl ) imide triethylamine salt can be effectively synthesized, and this salt has excellent ion exchange ability and can be efficiently exchanged to obtain bis ( fluorosulfonyl ) imide metal salt. However, in this reaction, excessive triethylamine promotes the formation of triethylamine fluorosulfonate, which is a hydrolysis product of SO 2 F 2 and other by-products. When this method is directly used in the production of lithium bis(fluorosulfonyl)imide, the subsequent purification cost is high. In addition, sulfuryl fluoride is costly, difficult to manufacture, highly toxic, strongly corrosive, and has a great impact on the safety environment.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Summary of the Invention

Problems to be Solved by the Invention

[0013] The technical problems to be solved by the present invention are as follows. The raw materials used in the production of lithium bis(fluorosulfonyl)imide in the prior art are highly toxic, highly corrosive, have high production costs, low yields and purities, and have a large impact on the environment.

[0014] In view of the deficiencies of the prior art, the first object of the present invention is to provide a method for producing lithium bis(fluorosulfonyl)imide, wherein the raw materials used are simple, the production cost is low, the generation of exhaust gas is small, the impact on the environment is small, the reaction yield is high, the purity of the product is high, and industrialization is easy. The second object of the present invention is to provide lithium bis(fluorosulfonyl)imide produced by the above production method. The third object of the present invention is to provide the use of lithium bis(fluorosulfonyl)imide produced by the above production method or the above lithium bis(fluorosulfonyl)imide in a lithium-ion battery.

Means for Solving the Problems

[0015] The technical solution of the present invention is as follows.

[0016] The present invention Lithium bis(fluorosulfonyl)imideTo provide a manufacturing method of react sulfur trioxide and ammonia in a high-pressure reactor to obtain Do imide disulfonic acid in step (1), where the reaction pressure is 0.8 - 1.5 Mpa in step (1); react dichlorosulfoxide with the imide disulfonic acid obtained in step (1), and perform vacuum distillation to obtain Do bis ( chlorosulfonyl ) imide in step (2); react bis ( chlorosulfonyl ) imide obtained in step (2) with hydrogen fluoride, and perform vacuum distillation to obtain bis ( fluorosulfonyl ) imide in step (3); react bis ( fluorosulfonyl ) imide obtained in step (3) with lithium fluoride, perform solid-liquid separation, purification and drying to obtain lithium bis(fluorosulfonyl)imide in step (4), including.

[0017] Preferably, in the above manufacturing method, in step (1), the molar ratio of the ammonia to sulfur trioxide is 1:2 - 3.

[0018] Preferably, in the above manufacturing method, in step (1), the reaction pressure is 0.8 - 1.0 MPa, preferably the reaction temperature is 20 - 30 °C, and more preferably the reaction time is 4 - 6 h.

[0019] Preferably, in the above manufacturing method, in step (2), the reaction temperature is 80 - 100 °C, preferably the reaction time is 12 - 16 hours.

[0020] Preferably, in the above manufacturing method, in step (2), the molar ratio of the imide Do disulfonic acid to dichlorosulfoxide is 1:2.0 - 2.5, preferably 1:2.2 - 2.5.

[0021] Preferably, in the above manufacturing method, in step (3), the bis ( chlorosulfonyl ) The molar ratio of imide to hydrogen fluoride is 1:2.0 to 3.0.

[0022] Preferably, in the above manufacturing method, in step (3), the reaction temperature is 80 to 150 °C, preferably 90 to 120 °C, and preferably, the reaction time is 14 to 20 h.

[0023] Preferably, in the above manufacturing method, in step (4), the bis ( fluorosulfonyl ) The molar ratio of imide to lithium fluoride is 1:0.85 to 1.00.

[0024] Preferably, in the above manufacturing method, in step (4), the reaction temperature is 120 °C to 160 °C, and preferably, the reaction time is 30 to 60 minutes.

[0025] The present invention further provides lithium bis(fluorosulfonyl)imide produced by the above manufacturing method, and the purity of the lithium bis(fluorosulfonyl)imide is ≥99.6%.

[0026] The present invention further provides the use of lithium bis(fluorosulfonyl)imide produced by the above manufacturing method or the above lithium bis(fluorosulfonyl)imide in a lithium-ion battery.

[0027] The present invention ( chlorosulfonyl ) Further provides a method for producing imide, Reacting sulfur trioxide and ammonia in a high-pressure reaction kettle to obtain imi Do Step (1) of disulfonic acid, wherein the reaction pressure is 0.8 to 1.5 Mpa, and step (1), Reacting dichlorosulfoxide with the imi Do Disulfonic acid obtained in step (1), and subjecting the reaction product to vacuum distillation to obtain bis( Chlorosulfonyl ) including step (2) of obtaining imide.

Advantages of the Invention

[0028] The beneficial effects of the present invention are as follows. The present invention uses sulfur trioxide and ammonia as raw materials to produce imide disulfonic acid, chlorinates thionyl dichloride to obtain bis(chlorosulfonyl)imide, and then sequentially performs fluorination and lithiation to produce lithium bis(fluorosulfonyl)imide. The raw materials used are simple, the production cost is low, the generated waste liquid, waste gas, and solid waste are less, the corrosivity is less, the process is environmentally friendly, the side reactions are less, it has an excellent yield, the purity of the product is high, and it can meet the requirements for the production volume and quality of large-scale industrial production. Do ( ( Chlorosulfonyl ) )

Modes for Carrying Out the Invention

[0029] To better understand the above technical solution, the technical solution of the present application will be described in detail with specific examples. The examples of the present application and the specific features in the examples are detailed descriptions of the technical solution of the present application, and do not limit the technical solution of the present application. It should be understood that the technical features in the examples of the present application and the examples can be combined with each other without conflict.

[0030] The method for producing lithium bis(fluorosulfonyl)imide provided by the present invention is a four-step reaction method, and the corresponding chemical reaction formula is as follows. 2SO 3 +NH 3 →HN(SO 3 H) 2 HN(SO 3 H) 2 +2SOCl 2 =HN(SO 2 Cl) 2 +2HCl↑+2SO 2 ↑ HN(SO 2 Cl) 2 + 2HF → HN(SO 2 F) 2 + 2HCl↑ HN(SO 2 F) 2 + LiF → LiN(SO 2 F) 2 + HF↑

[0031] The present invention provides a method for producing lithium bis(fluorosulfonyl)imide.

[0032] In a preferred embodiment of the present invention, specifically, the production method comprises: Step (1) of reacting sulfur trioxide and ammonia in a high-pressure reactor to obtain imidosulfonic acid, wherein the reaction pressure is 0.8 to 1.5 Mpa; Do Step (2) of reacting thionyl dichloride with the imidosulfonic acid obtained in step (1), followed by vacuum distillation to obtain bis(chlorosulfonyl)imide; Step (3) of reacting the bis(chlorosulfonyl)imide obtained in step (2) with hydrogen fluoride, followed by vacuum distillation to obtain bis(fluorosulfonyl)imide; Do Step (4) of reacting the bis(fluorosulfonyl)imide obtained in step (3) with lithium fluoride, followed by solid-liquid separation, purification and drying to obtain lithium bis(fluorosulfonyl)imide. ( chlorosulfonyl ) imide bis ( chlorosulfonyl ) imide ( fluorosulfonyl ) imide bis ( fluorosulfonyl ) imide

[0033] In step (1), the molar ratio of ammonia to sulfur trioxide is 1:2 to 3. Excessive sulfur trioxide is used to completely react ammonia. If ammonia is excessive, it will further react with imi DoReact with disulfonic acid to avoid generating unnecessary by-products. The reaction pressure is 0.8 - 1.5 Mpa. When the pressure is lower than 0.8 MPa, ammonia cannot be liquefied, and it is difficult for the reaction to proceed. When the pressure is higher than 1.5 MPa, there is no significant difference in the reaction yield and reaction rate, and it brings great safety concerns. Therefore, preferably, the reaction pressure is 0.8 - 1.0 MPa. More preferably, the reaction temperature is 20 - 30 °C. When the reaction temperature is lower than 20 °C, the reaction rate slows down and the reaction yield decreases. When the temperature is higher than 30 °C, it is necessary to liquefy ammonia at a higher pressure. Even more preferably, the reaction time is 4 - 6 h.

[0034] Step (1) is carried out in a high-pressure reactor. Specifically, first, sulfur trioxide is added to the reactor, then ammonia is flowed into it, pressurized with nitrogen gas. After the reaction is completed, the nitrogen gas is released to relieve the pressure, and the temperature is raised to 80 °C to remove the unreacted sulfur trioxide, and imi Do disulfonic acid is obtained.

[0035] In step (2), the reaction temperature is 80 - 100 °C. Preferably, the reaction time is 12 - 16 hours. The molar ratio of imi Do disulfonic acid to dichlorosulfoxide is 1:2.0 - 2.5, preferably 1:2.2 - 2.5. In this reaction, 1 equivalent of imi Do disulfonic acid reacts with 2 equivalents of dichlorosulfoxide. Since the reaction temperature is high and part of the dichlorosulfoxide is lost during the reflux process, generally the minimum usage amount of dichlorosulfoxide is 2.2 equivalents. When the dichlorosulfoxide exceeds 2.5 equivalents, it has no significant impact on the reaction yield and reaction rate. After the reaction is completed, the reaction product is subjected to vacuum distillation at 120 - 130 °C for 3 - 5 h. The vacuum degree of the vacuum distillation is -0.05 MPa - -0.09 MPa, and bis ( chlorosulfonyl ) imide is obtained.

[0036] In step (3), bis ( chlorosulfonyl )The molar ratio of imide to hydrogen fluoride is 1:2.0 to 3.0. The reaction temperature is 80 to 150 °C, preferably 90 to 120 °C, and preferably, the reaction time is 14 to 20 h. After the reaction is completed, nitrogen gas is blown into the system for 4 h to remove the generated hydrogen chloride gas and unreacted hydrogen fluoride gas.

[0037] In step (3), the vacuum distillation is carried out at 90 to 110 °C, the degree of vacuum of the vacuum distillation is -0.05 MPa to -0.09 MPa, the vacuum distillation time is 2 to 3 h, and the fraction obtained by the vacuum distillation is bis ( fluorosulfonyl ) imide, and the distillation residue is the next bis ( fluorosulfonyl ) imide involved in the production reaction of bis

[0038] In step (4), the molar ratio of bis ( fluorosulfonyl ) imide to lithium fluoride is 1:0.85 to 1.00. In this reaction, the post-treatment of lithium fluoride is difficult, and it is difficult to remove the remaining lithium fluoride. Therefore, it is preferable to completely react lithium fluoride. The reaction temperature is 120 °C to 160 °C, and preferably, the reaction time is 30 to 60 minutes. After the reaction is completed, nitrogen gas is blown into the system for 1 h to remove the generated hydrogen fluoride gas, and then the obtained lithium bis(fluorosulfonyl)imide is purified and dried to obtain lithium bis(fluorosulfonyl)imide. The purification operation includes washing the reaction product with dichloromethane to remove the remaining bis ( fluorosulfonyl ) imide, then dissolving it in diethyl ether, removing impurities by filtration, then evaporating and concentrating, adding an organic solvent to recrystallize the concentrated solution, and finally drying to obtain lithium bis(fluorosulfonyl)imide.

[0039] The lithium bis(fluorosulfonyl)imide produced by the production method of the present invention has a purity of ≧99.6%.

[0040] The present invention further provides lithium bis(fluorosulfonyl)imide produced by the above manufacturing method or the use of the above lithium bis(fluorosulfonyl)imide in a lithium ion battery.

[0041] The present invention further provides a method for manufacturing bis ( chlorosulfonyl ) imide, comprising: Step (1) of reacting sulfur trioxide and ammonia in a high-pressure reactor to obtain imi Do disulfonic acid, wherein the reaction pressure is 0.8 to 1.5 Mpa; and Step (2) of reacting dichlorosulfoxide with the imi Do disulfonic acid obtained in Step (1), followed by vacuum distillation to obtain bis ( chlorosulfonyl ) imide.

[0042] (Example) All raw materials or reagents used in the present invention were purchased from mainstream manufacturers in the market. If the production manufacturer or concentration is not specified, they are all secondary-standard raw materials or reagents that are readily available daily and are not particularly limited as long as they can achieve the desired effect. All the instrument and equipment used in this example were purchased from major manufacturers in the market and are not particularly limited as long as they can achieve the desired role. In this example, when specific techniques or conditions are not specified, they were carried out according to the techniques or conditions described in the literature within the art or according to the product specifications. Regarding the instruments, a 2L high-pressure reactor manufactured by Weihai Huanyu Chemical Industry Machinery Co., Ltd. was adopted; a Metrohm 833 type high-pressure ion chromatography was adopted for ion chromatography; an AVANCE-400 manufactured by Bruker, Germany was adopted for the nuclear magnetic resonance analyzer.

[0043] (Example 1) (1) Add 160.0 g of sulfur trioxide (molecular weight 80.06 g / mol) to a high-pressure reactor, control the temperature at 25 °C, flow 17.0 g of ammonia (molecular weight 17.03 g / mol) into the reactor, then flow nitrogen gas until the pressure in the reactor reaches 0.8 Mpa, react at 20 °C for 6 hours, after the reaction is complete, release the nitrogen gas in the reactor, heat to 80 °C to remove the remaining sulfur trioxide, and obtain 165.3 g of the product. The product is 1 Identified as imi Do disulfonic acid (molecular weight 177.15 g / mol) by H-NMR spectrum, and the imi Do H-NMR spectrum of disulfonic acid is 1 as follows 1 H-NMR (400M, DMSO-d6): δ: 4.31 (s, 2H), δ: 6.91 (s, 1H). (2) Add 165.3 g of the imi Do disulfonic acid obtained in step (1) to the reactor, heat to 80 °C, slowly drop 245.1 g of thionyl chloride (molecular weight 118.97 g / mol) into it, absorb the off-gas generated during the reaction with potassium hydroxide alkaline solution, stir and react for 12 hours, then cool to room temperature, and perform vacuum distillation at a vacuum degree of -0.05 MPa and 120 °C for 5 h to obtain 180.5 g of the product. The product is 1 Identified as bis ( chlorosulfonyl ) imide (molecular weight 214.03 g / mol) by H-NMR spectrum. (3) Add 180.5 g of the bis ( chlorosulfonyl ) imide obtained in step (2) to the reactor, heat to 80 °C, slowly flow 33.8 g of HF (molecular weight 20.01 g / mol) gas into it, react for 14 hours, then cool to room temperature, blow nitrogen gas into the reactor for 4 hours, and then perform vacuum distillation at -0.05 MPa and 90 °C for 3 h to obtain 126.8 g of bis ( fluorosulfonyl ) imide (molecular weight 181.13 g / mol). (4) Add 18.15 g of lithium fluoride (molecular weight 25.94 g / mol) to the reactor, heat to 120 °C, and the bis (Fluorosulfonyl ) 126.8 g of imide was slowly added dropwise and reacted for 30 minutes. Then, nitrogen gas was blown into the reactor for 1 hour, and the temperature was lowered to room temperature. The filter cake obtained by filtration was washed with dichloromethane, and then the filter cake was dissolved in ethyl ether, filtered to remove impurities to obtain a filtrate, concentrated to 30% by weight using a rotary evaporator, and then the concentrated solution was recrystallized with dimethyl carbonate and finally dried under vacuum to obtain 117.8 g of lithium bis(fluorosulfonyl)imide (molecular weight 187.07 g / mol). The purity of lithium bis(fluorosulfonyl)imide was measured by Metrohm 833 type high-pressure ion chromatography. The test results of related parameters are shown in Table 1.

[0044] (Example 2) (1) 239 g of sulfur trioxide was added to a high-pressure reactor, the temperature was controlled at 25 °C, 17.0 g of ammonia was flowed into the reactor, and then nitrogen gas was flowed until the internal pressure of the reactor reached 1.0 Mpa, and the reaction was carried out at 30 °C for 5 hours. After the reaction was completed, the nitrogen gas in the reactor was released, heated to 80 °C to remove the remaining sulfur trioxide, and 168.3 g of the product was obtained. The product was 1 identified as imi Do disulfonic acid by 1H-NMR spectrum, and the Do 1H-NMR spectrum of the disulfonic acid 1 is 1 1H-NMR (400M, DMSO-d6): δ: 4.31 (s, 2H), δ: 6.91 (s, 1H). (2) 168.3 g of the imi Do disulfonic acid obtained in step (1) was added to a reactor, heated to 100 °C, and 282 g of dichlorosulfoxide was slowly added dropwise thereto. The off-gas generated during the reaction was absorbed with a potassium hydroxide alkaline solution, and after stirring and reacting for 16 hours, the temperature was lowered to room temperature, and vacuum distillation was carried out at a vacuum degree of -0.09 MPa and 130 °C for 3 h to obtain 189.8 g of the product. The product was 1 identified as bis ( chlorosulfonyl ) imide by 1H-NMR spectrum. (3) The bis obtained in step (2)( Chlorosulfonyl ) 189.8 g of imide was added to the reactor, heated to 90 °C, 53 g of HF gas was slowly passed through, reacted for 20 hours, then cooled to room temperature, nitrogen gas was blown into the reactor for 4 hours, and then vacuum distillation was carried out at -0.09 MPa and 110 °C for 2 h to obtain bis ( Fluorosulfonyl ) imide 141.8 g. (4) 17.28 g of lithium fluoride was added to the reactor, heated to 160 °C, and 141.8 g of bis ( Fluorosulfonyl ) imide obtained in step (3) was slowly added dropwise, reacted for 60 minutes, then nitrogen gas was blown into the reactor for 1 hour, cooled to room temperature, then the reaction product was washed with dichloromethane, the filter cake obtained by filtration was washed with dichloromethane, then the filter cake was dissolved in ethyl ether, filtered to remove impurities to obtain a filtrate, concentrated to 30% by weight with a rotary evaporator, then the concentrated solution was recrystallized with dimethyl carbonate, and finally vacuum dried to obtain 115.05 g of lithium bis(fluorosulfonyl)imide. The purity of lithium bis(fluorosulfonyl)imide was measured by Metrohm 833 type high pressure ion chromatography. The test results of related parameters are shown in Table 1.

[0045] (Example 3) (1) 200.2 g of sulfur trioxide was added to a high-pressure reactor, the temperature was controlled at 25 °C, 17.0 g of ammonia was passed through the reactor, then nitrogen gas was passed through until the internal pressure of the reactor reached 0.9 Mpa, reacted at 25 °C for 6 hours, the reaction was completed, the nitrogen gas in the reactor was released, heated to 80 °C to remove the remaining sulfur trioxide, and 166.7 g of product was obtained. The product was 1 identified as imi Do disulfonic acid by H-NMR spectrum, and the Do H-NMR spectrum of the imi 1 disulfonic acid is 1 H-NMR (400M, DMSO-d6): δ: 4.31 (s, 2H), δ: 6.91 (s, 1H). (2) The imi obtained in step (1)Do 166.7 g of disulfonic acid was added to the reactor, heated to 90 °C, and 268.9 g of thionyl dichloride was slowly added dropwise thereto. The off-gas generated during the reaction was absorbed with a potassium hydroxide alkaline solution, and after stirring and reacting for 14 hours, the temperature was lowered to room temperature, and vacuum distillation was carried out under the conditions of a vacuum degree of -0.05 MPa and 125 °C for 4 h to obtain 186.2 g of a product. The product was 1 identified as bis ( chlorosulfonyl ) imide by H-NMR spectrum. (3) 186.2 g of bis ( chlorosulfonyl ) imide was added to the reactor, heated to 100 °C, and 43.52 g of HF gas was slowly passed through. After reacting for 16 hours, the temperature was lowered to room temperature, nitrogen gas was blown into the reactor for 4 hours, and then vacuum distillation was carried out at -0.05 MPa and 100 °C for 3 h to obtain 134.4 g of bis ( fluorosulfonyl ) imide. (4) 17.3 g of lithium fluoride was added to the reactor, heated to 140 °C, and 134.4 g of bis ( fluorosulfonyl ) imide obtained in step (3) was slowly added dropwise. After reacting for 45 minutes, nitrogen gas was blown into the reactor for 1 hour, the temperature was lowered to room temperature, and then the reaction product was washed with dichloromethane. The filter cake obtained by filtration was dissolved in ethyl ether, filtered to remove impurities to obtain a filtrate, concentrated to 30% by weight with a rotary evaporator, then recrystallized with a dimethyl carbonate concentrate, and finally vacuum dried to obtain 114.1 g of lithium bis(fluorosulfonyl)imide. The purity of lithium bis(fluorosulfonyl)imide was measured by Metrohm 833 type high-pressure ion chromatography. The test results of related parameters are shown in Table 1.

[0046] (Example 4) (1) Add 183.8 g of sulfur trioxide to a high-pressure reactor, control the temperature at 25 °C, flow 17.0 g of ammonia into the reactor, then flow nitrogen gas until the pressure in the reactor reaches 1.5 Mpa, react at 30 °C for 4 hours. After the reaction is completed, release the nitrogen gas in the reactor, heat to 80 °C to remove the remaining sulfur trioxide, and obtain 164.9 g of the product. The product is 1 identified as imi Do disulfonic acid by H-NMR spectrum, and the Do H-NMR spectrum of the disulfonic acid is 1 as follows, 1 H-NMR (400M, DMSO-d6): δ: 4.31 (s, 2H), δ: 6.91 (s, 1H). (2) Add 164.9 g of the imi Do disulfonic acid obtained in step (1) to a reactor, heat to 90 °C, slowly drop 222.63 g of thionyl chloride into it, absorb the off-gas generated during the reaction with a potassium hydroxide alkaline solution, stir and react for 13 hours, then cool to room temperature, and perform vacuum distillation at a vacuum degree of -0.05 MPa and 125 °C for 4 h to obtain 181.73 g of the product. The product is 1 identified as bis ( chlorosulfonyl ) imide by H-NMR spectrum. (3) Add 181.73 g of the bis ( chlorosulfonyl ) imide obtained in step (2) to a reactor, heat to 150 °C, slowly flow 47.57 g of HF gas into it, react for 18 hours, then cool to room temperature, blow nitrogen gas into the reactor for 4 hours, and then perform vacuum distillation at -0.05 MPa and 100 °C for 3 h to obtain 127.96 g of bis ( fluorosulfonyl ) imide. (4) Add 17.41 g of lithium fluoride to a reactor, heat to 150 °C, and the bis ( fluorosulfonyl )127.96 g of imide was slowly added dropwise and reacted for 40 minutes. Then, nitrogen gas was blown into the reactor for 1 hour, and the temperature was lowered to room temperature. The filter cake obtained by filtration was washed with dichloromethane, and then the filter cake was dissolved in ethyl ether, filtered to remove impurities to obtain a filtrate, concentrated to 30% by weight using a rotary evaporator, and then the dimethyl carbonate concentrate was recrystallized and finally dried under vacuum to obtain 115.0 g of lithium bis(fluorosulfonyl)imide. The purity of lithium bis(fluorosulfonyl)imide was measured by Metrohm 833 type high-pressure ion chromatography. The test results of related parameters are shown in Table 1.

[0047] (Comparative Example 1) (1) Under a nitrogen gas atmosphere, 97.09 g (97.09 g / mol) of sulfamic acid, 116.53 g (molecular weight 116.53 g / mol) of chlorosulfonic acid, and 261.7 g of dichlorosulfoxide were sequentially added to the reactor, heated to 130 °C and reacted for 24 hours. After the reaction was completed, low-boiling compounds were removed by atmospheric distillation, and then vacuum distillation was performed to collect the fraction at 112 - 114 °C / 2 mmHg, cooled to room temperature to obtain 175.1 g of bis ( chlorosulfonyl ) imide. The reaction formula is as follows. NH 2 SO 3 H+ClSO 3 H+2SOCl 2 →Cl 2 HNO 4 S 2 +3HCl↑+SO 2 ↑ (2) 175.1 g of bis ( chlorosulfonyl ) imide obtained in step (1) was added to the reactor, heated to 80 °C, and 32.78 g of HF gas was slowly passed through and reacted for 14 hours. Then, the temperature was lowered to room temperature, nitrogen gas was blown into the reactor for 4 hours, and then vacuum distillation was performed at -0.05 MPa and 90 °C for 3 hours to obtain 120.20 g of bis ( fluorosulfonyl ) imide. (3) Add 5.0 g of lithium fluoride to the reactor, heat it to 120 °C, and slowly add dropwise 34.91 g of bis ( fluorosulfonyl ) imide. After reacting for 30 minutes, blow nitrogen gas into the reactor for 1 hour, cool it to room temperature, then wash the reaction product with dichloromethane. Dissolve the filter cake obtained by filtration in ethyl ether, filter to remove impurities to obtain a filtrate, concentrate it to 30% by weight using a rotary evaporator, then recrystallize the dimethyl carbonate concentrate, and finally dry it under vacuum to obtain 31.92 g of lithium bis(fluorosulfonyl)imide. The purity of lithium bis(fluorosulfonyl)imide was measured by Metrohm 833 type high-pressure ion chromatography. The test results of related parameters are shown in Table 1.

[0048] (Comparative Example 2) Steps (1) and (2) are the same as those in Comparative Example 1. (3) Add 5.0 g of lithium fluoride to the reactor, heat it to 70 °C, and slowly add dropwise 34.91 g of bis ( fluorosulfonyl ) imide. After reacting for 12 hours, blow nitrogen gas into the reactor for 1 hour, cool it to room temperature, then wash the reaction product with dichloromethane. Dissolve the filter cake obtained by filtration in ethyl ether, filter to remove impurities to obtain a filtrate, concentrate it to 30% by weight using a rotary evaporator, then recrystallize the dimethyl carbonate concentrate, and finally dry it under vacuum to obtain 30.04 g of lithium bis(fluorosulfonyl)imide. The purity of lithium bis(fluorosulfonyl)imide was measured by Metrohm 833 type high-pressure ion chromatography. The test results of related parameters are shown in Table 1.

[0049]

Table 1

[0050] As is apparent from Table 1, the purity of the examples of the present invention is superior to that of Comparative Examples 1 and 2, and the total yields of Examples 1 to 4 are 63.11% to 72.4%, all of which are superior to those of the comparative examples.

[0051] Compared with Example 1, Comparative Example 1 used sulfamic acid, chlorosulfonic acid and dichlorosulfoxide to produce bis ( chlorosulfonyl ) imide, and the yield of bis ( chlorosulfonyl ) imide was 81.8%, which was lower than the total yield of 84.48% of bis ( chlorosulfonyl ) imide in Example 1. Therefore, the total yield of lithium bis(fluorosulfonyl)imide was also lower than that in Example 1. As can be seen from the synthesis route, 1 mol of bis ( chlorosulfonyl ) imide was produced by the method of Comparative Example 1, generating 2 mol of sulfur dioxide gas and 3 mol of hydrogen chloride gas. However, when the present invention was adopted, only 2 mol of hydrogen chloride gas and 2 mol of sulfur dioxide gas were generated, reducing the amount of exhaust gas generated. Moreover, the raw materials of the present invention are simple, the manufacturing cost is low, the corrosiveness is small, and the impact on the environment is small. In Comparative Example 1, impurities such as lithium fluorosulfonate remained, resulting in a decrease in purity.

[0052] Comparative Example 2 used sulfamic acid, chlorosulfonic acid and dichlorosulfoxide to produce bis ( chlorosulfonyl ) imide, and the synthesis of lithium bis(fluorosulfonyl)imide adopted a process with a low reaction temperature and a long reaction time, resulting in lower yields and purity.

[0053] As described above, the present invention uses sulfur trioxide and ammonia as raw materials to produce imi Do disulfonic acid, and chlorinates dichlorosulfoxide to produce bis ( chlorosulfonyl )An imide is obtained, and then fluorination and lithiation are sequentially performed to produce lithium bis(fluorosulfonyl)imide. The raw materials used are simple, the production cost is low, the generated waste liquid, waste gas, and solid waste are few, the process is environmentally friendly, the side reactions are few, it has an excellent yield, the purity of the product is high, and it can meet the requirements for the production volume and quality of large-scale industrial production.

[0054] The above are only preferred embodiments of the present invention and do not limit the present invention in any way. Modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention must all be included in the protection scope of the present invention.

[0055] (Appendix) (Appendix 1) A method for producing lithium bis(fluorosulfonyl)imide, comprising: reacting sulfur trioxide and ammonia in a high-pressure reactor to obtain imidodisulfonic acid in step (1), wherein the reaction pressure in step (1) is 0.8 to 1.5 Mpa; Do reacting thionyl dichloride with the imidodisulfonic acid obtained in step (1), and performing vacuum distillation to obtain bis(chlorosulfonyl)imide in step (2); reacting the bis(chlorosulfonyl)imide obtained in step (2) with hydrogen fluoride, and performing vacuum distillation to obtain bis(fluorosulfonyl)imide in step (3); Do reacting the bis(fluorosulfonyl)imide obtained in step (3) with lithium fluoride, performing solid-liquid separation, purification, and drying to obtain lithium bis(fluorosulfonyl)imide in step (4). ( chlorosulfonyl ) imidodisulfonic acid bis(chlorosulfonyl) ( imide ) reacting the bis(chlorosulfonyl)imide obtained in step (2) with hydrogen fluoride, and performing vacuum distillation to obtain bis(fluorosulfonyl)imide in step (3); ( fluorosulfonyl ) imide bis(fluorosulfonyl) ( imide ) reacting the bis(fluorosulfonyl)imide obtained in step (3) with lithium fluoride, performing solid-liquid separation, purification, and drying to obtain lithium bis(fluorosulfonyl)imide in step (4). A method for producing lithium bis(fluorosulfonyl)imide, characterized by the above.

[0056] (Appendix 2) In step (1), the molar ratio of the ammonia to sulfur trioxide is 1:2 to 3. The method for producing lithium bis(fluorosulfonyl)imide according to Supplementary Note 1, characterized by this.

[0057] (Supplementary Note 3) In step (1), the reaction pressure is 0.8 to 1.0 MPa. The method for producing lithium bis(fluorosulfonyl)imide according to Supplementary Note 1 or 2, characterized by this.

[0058] (Supplementary Note 4) In step (1), the reaction temperature is 20 to 30 °C. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Supplementary Notes 1 to 3, characterized by this.

[0059] (Supplementary Note 5) In step (1), the reaction time is 4 to 6 h. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Supplementary Notes 1 to 4, characterized by this.

[0060] (Supplementary Note 6) In step (2), the reaction temperature is 80 to 100 °C. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Supplementary Notes 1 to 5, characterized by this.

[0061] (Supplementary Note 7) In step (2), the reaction time is 12 to 16 hours. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Supplementary Notes 1 to 6, characterized by this.

[0062] (Supplementary Note 8) In step (2), the Do molar ratio of the imid disulfonic acid to dichlorosulfoxide is 1:2.0 to 2.5, preferably 1:2.2 to 2.5. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Appendices 1 to 7, characterized in that...

[0063] (Appendix 9) In step (3), bis ( chlorosulfonyl ) The molar ratio of imide to hydrogen fluoride is 1:2.0 to 3.0. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Appendices 1 to 8, characterized in that...

[0064] (Appendix 10) In step (3), the reaction temperature is 80 to 150 °C, preferably 90 to 120 °C, and preferably, the reaction time is 14 to 20 h. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Appendices 1 to 9, characterized in that...

[0065] (Appendix 11) In step (4), bis ( fluorosulfonyl ) The molar ratio of imide to lithium fluoride is 1:0.85 to 1.00. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Appendices 1 to 10, characterized in that...

[0066] (Appendix 12) In step (4), the reaction temperature is 120 °C to 160 °C, and preferably, the reaction time is 30 to 60 minutes. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Appendices 1 to 11, characterized in that...

[0067] (Appendix 13) Lithium bis(fluorosulfonyl)imide produced by the production method according to any one of Appendices 1 to 12, wherein the purity of the lithium bis(fluorosulfonyl)imide is ≧99.6%. Lithium bis(fluorosulfonyl)imide, characterized by the following.

[0068] (Appendix 14) Use of lithium bis(fluorosulfonyl)imide produced by the production method described in any one of Appendices 1 to 12 or lithium bis(fluorosulfonyl)imide described in Appendix 13 in a lithium-ion battery.

[0069] (Appendix 15) Bis ( Chlorosulfonyl ) A method for producing imide, comprising: Reacting sulfur trioxide and ammonia in a high-pressure reactor to obtain imi Do Step (1) of obtaining disulfonic acid, wherein the reaction pressure is 0.8 to 1.5 Mpa; Reacting dichlorosulfoxide with the imi Do Disulfonic acid obtained in step (1), followed by vacuum distillation to obtain bis ( Chlorosulfonyl ) Step (2) of obtaining imide. Characterized by the following. ( Chlorosulfonyl ) A method for producing imide.

Claims

1. A method for producing lithium bis(fluorosulfonyl)imide, comprising: Step (1) of reacting sulfur trioxide and ammonia in a high-pressure reactor to obtain imidodisulfonic acid (HN(SO₃H)₂), wherein the reaction pressure is 0.8 to 1.5 MPa, the reaction temperature is 20 to 30 °C, and the molar ratio of the ammonia to sulfur trioxide is 1:2 to 3; Step (2) of reacting thionyl dichloride with the imidodisulfonic acid obtained in Step (1) and performing vacuum distillation to obtain bis(chlorosulfonyl)imide, wherein the reaction temperature is 80 to 100 °C, and the molar ratio of the imidodisulfonic acid to thionyl dichloride is 1:2.0 to 2.5; Step (3) of reacting the bis(chlorosulfonyl)imide obtained in Step (2) with hydrogen fluoride and performing vacuum distillation to obtain bis(fluorosulfonyl)imide, wherein the reaction temperature is 80 to 150 °C, and the molar ratio of the bis(chlorosulfonyl)imide to hydrogen fluoride is 1:2.0 to 3.0; Step (4) of reacting the bis(fluorosulfonyl)imide obtained in Step (3) with lithium fluoride, performing solid-liquid separation, purification, and drying to obtain lithium bis(fluorosulfonyl)imide, wherein the reaction temperature is 120 °C to 160 °C, and the molar ratio of the bis(fluorosulfonyl)imide to lithium fluoride is 1:0.85 to 1.

00. A method for producing lithium bis(fluorosulfonyl)imide, characterized by the above.

2. In Step (1), the reaction pressure is 0.8 to 1.0 MPa. The method for producing lithium bis(fluorosulfonyl)imide according to Claim 1, characterized by the above.

3. In Step (1), the reaction time is 4 to 6 h. The method for producing lithium bis(fluorosulfonyl)imide according to Claim 1 or 2, characterized by the above.

4. In Step (2), the reaction time is 12 to 16 h. The method for producing lithium bis(fluorosulfonyl)imide according to any one of Claims 1 to 3, characterized by the above.

5. In Step (2), the molar ratio of the imidodisulfonic acid to thionyl dichloride is 1:2.2 to 2.

5. The method for producing lithium bis(fluorosulfonyl)imide according to any one of claims 1 to 4, characterized in that...

6. In step (3), the reaction temperature is 90 to 120 °C, The method for producing lithium bis(fluorosulfonyl)imide according to any one of claims 1 to 5, characterized in that...

7. In step (3), the reaction time is 14 to 20 h, and / or in step (4), the reaction time is 30 to 60 minutes, The method for producing lithium bis(fluorosulfonyl)imide according to any one of claims 1 to 6, characterized in that...

8. A method of using lithium bis(fluorosulfonyl)imide produced by the production method according to any one of claims 1 to 7 in a lithium-ion battery.

9. A method for producing bis(chlorosulfonyl)imide, Step (1) of reacting sulfur trioxide and ammonia in a high-pressure reactor to obtain imidodisulfonic acid (HN(SO₃H)₂), wherein the reaction pressure is 0.8 to 1.5 MPa, the reaction temperature is 20 to 30 °C, and the molar ratio of ammonia to sulfur trioxide is 1:2 to 3, Step (2) of reacting dichlorosulfoxide with the imidodisulfonic acid obtained in step (1) and performing vacuum distillation to obtain bis(chlorosulfonyl)imide, wherein the reaction temperature is 80 to 100 °C, and the molar ratio of the imidodisulfonic acid to dichlorosulfoxide is 1:2.0 to 2.5, including... The method for producing bis(chlorosulfonyl)imide, characterized in that...

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