A method for pretreating a perfluorosulfonic acid resin and a method for preparing bischlorosulfonylimide

Abstract

The present application belongs to the technical field of lithium ion battery electrolyte, and particularly relates to a pretreatment method of perfluorosulfonic acid resin and a preparation method of bischlorosulfonylimide. The pretreatment method comprises the following steps: heating the perfluorosulfonic acid resin to 90-100 DEG C under a vacuum degree of 9000-10000 Pa, first stirring, then introducing HCl gas to a certain pressure, secondly stirring under heat preservation, replacing with nitrogen, cooling to room temperature, and obtaining the pretreated perfluorosulfonic acid resin. The perfluorosulfonic acid resin is pretreated and then put into the reaction as a catalyst, so that the reaction efficiency and yield are improved, the catalyst can be recycled for at least ten times, and the cost is greatly saved.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery electrolyte technology, and particularly relates to a pretreatment method for perfluorosulfonic acid resin and a preparation method for dichlorosulfonyl imide. Background Technology

[0002] Difluorosulfonyl imide salts have important applications in various fields, including as additives in battery electrolytes and conductive coating materials. Dichlorosulfonylimide (HN(SO2Cl)2) is an important precursor for the synthesis of difluorosulfonyl imide salts. Various difluorosulfonyl imide salts can be generated through reactions with fluorinating agents or through cation exchange reactions following reactions with fluorinating agents.

[0003] The preparation of bis(chlorosulfonyl)imide from chlorosulfonate isocyanate and chlorosulfonic acid is an important route for producing lithium bis(fluorosulfonyl)imide. However, the biggest problem with this route is the long reaction time of chlorosulfonate isocyanate and chlorosulfonic acid, which severely limits production capacity. Many existing process improvements involve introducing catalysts to accelerate the reaction. However, both solid powder catalysts and liquid catalysts can only be used once, i.e., they are treated as waste, which is neither economical nor environmentally friendly. Since this reaction is a high-temperature, strongly acidic system, conventional organic supported catalysts are destroyed and poisoned after a few uses, while inorganic supported catalysts have very low catalytic efficiency.

[0004] Therefore, there is an urgent need to find a new catalyst suitable for the preparation method of dichlorosulfonylimide. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a pretreatment method for perfluorosulfonic acid resin and a preparation method for dichlorosulfonyl imide. By pretreating the perfluorosulfonic acid resin and then adding it to the reaction as a catalyst, not only can the reaction efficiency be improved and the yield increased, but the catalyst can also be reused at least ten times after recovery, which greatly saves costs.

[0006] This invention provides a pretreatment method for perfluorosulfonic acid resin, the pretreatment method comprising the following steps:

[0007] The perfluorosulfonic acid resin was heated to 90-100℃ under a vacuum of 9000-10000Pa, stirred for the first time, and then HCl gas was introduced to a certain pressure. After holding at the temperature for the second time and stirring, nitrogen was used for purging. The mixture was then cooled to room temperature to obtain the pretreated perfluorosulfonic acid resin.

[0008] In some embodiments of the present invention, the first stirring time is 1 to 2 hours.

[0009] In some embodiments of the present invention, HCl gas is introduced to a pressure of 0.01~0.1 MPa.

[0010] In some embodiments of the present invention, the second stirring time is 1-2 hours.

[0011] Another aspect of the present invention provides a method for preparing dichlorosulfonylimide, the method comprising:

[0012] Pretreated perfluorosulfonic acid resin was added to chlorosulfonyl isocyanate, heated, and then chlorosulfonic acid was added dropwise. The mixture was kept warm and stirred, and then distilled to obtain dichlorosulfonyl imide.

[0013] The pretreated perfluorosulfonic acid resin is obtained by treating it using the pretreatment method for perfluorosulfonic acid resin as described in this invention.

[0014] In some embodiments of the present invention, the mass ratio of the chlorosulfonyl isocyanate to the pretreated perfluorosulfonic acid resin is 1:(0.08~0.20).

[0015] In some embodiments of the present invention, pretreated perfluorosulfonic acid resin is added to chlorosulfonyl isocyanate at 25-30°C.

[0016] In some embodiments of the present invention, the molar ratio of chlorosulfonyl isocyanate to chlorosulfonic acid is 1:(1~1.02).

[0017] In some embodiments of the present invention, the dripping rate is 100~200g / h and the dripping time is 0.5~1h.

[0018] In some embodiments of the present invention, the heating temperature is 90~110°C.

[0019] In some embodiments of the present invention, the temperature of the heat-preserving stirring is 90~110°C.

[0020] In some embodiments of the present invention, the heat preservation and stirring time is 7 to 9 hours.

[0021] By adopting the aforementioned technical solution, the beneficial effects of the present invention are:

[0022] This invention pretreats the perfluorosulfonic acid resin to obtain the pretreated perfluorosulfonic acid resin, and then uses the pretreated perfluorosulfonic acid resin as a catalyst in the preparation method of dichlorosulfonylimide. This not only improves the reaction efficiency and increases the yield (which is above 94%), but also allows the catalyst to be reused at least ten times after recovery, greatly saving costs. The yield after reuse is still above 94%. Detailed Implementation

[0023] The following describes in detail the embodiments of the preparation method of dichlorosulfonylimide provided by the present invention.

[0024] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0025] Nafion-H, a perfluorosulfonic acid resin, is an ionomer with a perfluorocarbon backbone and sulfonic acid side chains, belonging to the category of the strongest known solid superacid materials. It possesses excellent heat resistance, chemical stability, and mechanical strength. This invention unexpectedly discovered that perfluorinated compounds, due to their stability against strong acids and high temperatures, can maintain their activity well in the reaction between chlorosulfonic acid isocyanate and chlorosulfonic acid. Therefore, when using perfluorosulfonic acid resin as a catalyst, it can effectively catalyze the reaction, accelerating the reaction rate; it can also be repeatedly reused without deactivation, greatly reducing production costs and being environmentally friendly. However, conventional perfluorosulfonic acid resins require high-temperature dehydration and high-pressure acidification for efficient catalytic reaction because: 1. The resin contains a large amount of water, which destroys chlorosulfonic acid isocyanate, leading to a reduced yield; 2. The high fluorine content in the perfluoro resin makes hydrogen bonding significant, making water removal difficult; 3. Hydrogen atoms in chlorosulfonic acid also form hydrogen bonds with fluorine in the perfluorosulfonic acid resin, which reduces catalytic efficiency and affects the conversion of chlorosulfonic acid. Through further extensive research and exploration, the inventors of this invention discovered that by pretreating perfluorosulfonic acid resin before adding it to the reaction as a catalyst, not only can the reaction efficiency and yield be improved, but the catalyst can also be reused at least ten times after recovery, greatly saving costs. Based on this, this application was completed.

[0026] Pretreatment methods for perfluorosulfonic acid resins

[0027] This invention provides a pretreatment method for perfluorosulfonic acid resin, the pretreatment method comprising the following steps:

[0028] The perfluorosulfonic acid resin was heated to 90-100℃ under a vacuum of 9000-10000Pa, stirred for the first time, and then HCl gas was introduced to a certain pressure. After holding at the temperature for the second time and stirring, nitrogen was used for purging. The mixture was then cooled to room temperature to obtain the pretreated perfluorosulfonic acid resin.

[0029] In the pretreatment method for perfluorosulfonic acid resin provided by the present invention, the perfluorosulfonic acid resin is selected from one or more of Nafion NR50, Nafion SAC-13, and Aquivion P98.

[0030] In the pretreatment method for perfluorosulfonic acid resin provided by this invention, the vacuum degree is 9000~10000 Pa and any value between them or any two values. It can be selected as 9000~9500 Pa, 9500~10000 Pa, 9000~9300 Pa, 9300~9500 Pa, 9500~9800 Pa, or 9800~10000 Pa. If the vacuum degree is less than 9000 Pa, water removal will be slower.

[0031] In the pretreatment method for perfluorosulfonic acid resin provided by this invention, the temperature is heated to 90-100°C or any value between these values, or any two of these values. 90-95°C or 95-100°C can be selected. If the temperature is too low, the dehydration process slows down.

[0032] In the pretreatment method for perfluorosulfonic acid resin provided by this invention, the first stirring time is 1 to 2 hours or any value between them, or a range between any two values. It can be selected as 1 to 1.5 hours or 1.5 to 2 hours.

[0033] In the pretreatment method for perfluorosulfonic acid resin provided by this invention, HCl gas is introduced to a pressure of 0.01~0.1 MPa and any value or any two values ​​therebetween. Optional pressures include 0.01~0.05 MPa, 0.05~0.1 MPa, 0.01~0.03 MPa, 0.03~0.05 MPa, 0.05~0.08 MPa, and 0.08~0.1 MPa. Too low a pressure results in poor activation.

[0034] In the pretreatment method for perfluorosulfonic acid resin provided by this invention, the second stirring time is 1 to 2 hours, or any value between them, or any two values. It can be selected as 1 to 1.5 hours or 1.5 to 2 hours.

[0035] Preparation method of dichlorosulfonyl imide

[0036] This invention also provides a method for preparing dichlorosulfonylimide, the method comprising:

[0037] Pretreated perfluorosulfonic acid resin was added to chlorosulfonyl isocyanate, heated, and then chlorosulfonic acid was added dropwise. The mixture was kept warm and stirred, and then distilled to obtain dichlorosulfonylimide.

[0038] .

[0039] The pretreated perfluorosulfonic acid resin is obtained by treating it using the pretreatment method for perfluorosulfonic acid resin described in this invention.

[0040] In the preparation method of bischlorosulfonylimide provided by the present invention, the mass ratio of chlorosulfonyl isocyanate to pretreated perfluorosulfonic acid resin is 1:(0.08~0.20) and any value between them or any range between any two values. Options include 1:(0.08~0.10), 1:(0.1~0.15), and 1:(0.15~0.20).

[0041] In the preparation method of dichlorosulfonyl imide provided by the present invention, chlorosulfonyl isocyanate is added at 25~30 o Pretreated perfluorosulfonic acid resin is added at C.

[0042] In the preparation method of dichlorosulfonylimide provided by the present invention, the molar ratio of chlorosulfonyl isocyanate and chlorosulfonic acid is 1:(1~1.02) and any value between them or any range between any two values. It can be selected as 1:(1~1.01) or 1:(1.01~1.02).

[0043] In the preparation method of bischlorosulfonylimide provided by this invention, the dropping rate is 100-200 g / h or any value between these values, or any two values ​​thereof. The dropping rate can be selected as 100-150 g / h, 150-200 g / h, 100-130 g / h, 130-150 g / h, 150-180 g / h, or 180-200 g / h. The dropping time is 0.5-1 h or any value between these values, or any two values ​​thereof. The dropping time can be selected as 0.5-0.8 h or 0.8-1 h. Dropping too slowly results in low efficiency. Dropping too quickly leads to severe gas release and poses a safety hazard.

[0044] In the preparation method of bischlorosulfonylimide provided by the present invention, the heating temperature is 90~110℃ and any value between them or any two values. It can be selected as 90~100℃, 100~110℃, or 95~105℃.

[0045] In the preparation method of bischlorosulfonylimide provided by the present invention, the temperature of the heat-preserving stirring is 90~110℃ and any value between them or any two values. It can be selected as 90~100℃, 100~110℃, or 95~105℃.

[0046] In the preparation method of dichlorosulfonylimide provided by this invention, the incubation and stirring time is 7 to 9 hours, or any value between them, or any two values. It can be selected as 7 to 8 hours or 8 to 9 hours.

[0047] The reactor residue (including the pretreated perfluorosulfonic acid resin catalyst) of the present invention can be reused, for example:

[0048] When reusing the catalyst, add the residue from the reactor to ethanol and stir for 1 to 2 hours. After drying the catalyst, it can be reused in the above-mentioned preparation method of dichlorosulfonylimide. It can be reused at least 10 times.

[0049] Dichlorosulfonamide

[0050] This invention also provides the use of bischlorosulfonylimide in the preparation of bisfluorosulfonylimide salts. The prepared bisfluorosulfonylimide salts can be used, for example, as additives in battery electrolytes and conductive coating materials.

[0051]

application

[0052] This invention also provides the use of bischlorosulfonylimide in the preparation of bisfluorosulfonylimide salts. The prepared bisfluorosulfonylimide salts can be used, for example, as additives in battery electrolytes and conductive coating materials.

[0053] The beneficial effects of the present invention will be further illustrated below with reference to the embodiments.

[0054] To make the inventive objectives, technical solutions, and beneficial effects of this invention clearer, the invention is further described in detail below with reference to embodiments. However, it should be understood that the embodiments of this invention are merely for illustrative purposes and not for limiting the invention, and the embodiments are not limited to those given in the specification. Unless otherwise specified, specific experimental or operational conditions in the embodiments were prepared under conventional conditions or according to the conditions recommended by the material supplier.

[0055] Furthermore, it should be understood that the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, does not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise stated. It should also be understood that the combined connection relationship between one or more devices / apparatus mentioned in this invention does not preclude the existence of other devices / apparatus before or after the combined devices / apparatus, or the insertion of other devices / apparatus between these explicitly mentioned devices / apparatus, unless otherwise stated. Moreover, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or limiting the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0056] In the following embodiments, unless otherwise specified, all the raw materials of the present invention are commercially available or prepared according to conventional methods in the art.

[0057] Example

[0058] Example 1

[0059] Example 1 provides a method for preparing dichlorosulfonylimide by reacting chlorosulfonyl isocyanate and chlorosulfonic acid with Nafion NR50 as an additive. The synthetic reaction formula is as follows:

[0060]

[0061] The preparation steps of dichlorosulfonylimide include:

[0062] Weigh 100g of Nafion NR50 and add it to a 200ml reaction flask. Add the solution under a vacuum of 9000-10000Pa until the volume reaches 90-100ml. o C. Stir for 1 hour. Introduce HCl gas until the pressure reaches 0.1 MPa. Maintain the temperature and stir for 1 hour. After purging with nitrogen, cool to room temperature. Set aside for later use.

[0063] Accurately weigh 143g of chlorosulfonyl isocyanate into a four-necked flask, 25-30 o Add 11.5g of processed Nafion NR50 to C and heat to 95-105°C. o C. 116.5 g of chlorosulfonic acid was slowly added dropwise (at a rate of 120 g / h and a time of 0.98 h) into the reaction flask. After stirring at the temperature for 8 hours, the product was distilled to obtain 204.1 g of product, with a yield of 95.4%.

[0064] Example 2

[0065] Example 2 provides a method for preparing dichlorosulfonylimide by reacting chlorosulfonyl isocyanate and chlorosulfonic acid with Nafion SAC-13 as an additive. The synthetic reaction formula is as follows:

[0066]

[0067] The preparation steps of dichlorosulfonylimide include:

[0068] Weigh 100g of Nafion SAC-13 and add it to a 200ml reaction flask. Add the solution under a vacuum of 9000-10000Pa until the volume reaches 90-100ml. o C. Stir for 1 hour. Introduce HCl gas until the pressure reaches 0.1 MPa. Maintain the temperature and stir for 1 hour. After purging with nitrogen, cool to room temperature. Set aside for later use.

[0069] Accurately weigh 143g of chlorosulfonyl isocyanate into a reaction flask, and heat for 25-30 minutes. o Add 23.3g of processed Nafion SAC-13 to temperature C and heat to 100-110°C. o C. Slowly add 116.5 g of chlorosulfonic acid dropwise (at a rate of 150 g / h and a time of 0.78 h) into the reaction flask. After stirring and maintaining the temperature for 8 hours, distill to obtain 203.8 g of the product, with a yield of 95.2%.

[0070] Example 3

[0071] Example 3 provides a method for preparing dichlorosulfonylimide by reacting chlorosulfonyl isocyanate and chlorosulfonic acid with Aquivion P98 as an additive. The synthetic reaction formula is as follows:

[0072]

[0073] The preparation steps of dichlorosulfonylimide include:

[0074] Weigh 100g of Nafion SAC-13 and add it to a 200ml reaction flask. Add the solution under a vacuum of 9000-10000Pa until the volume reaches 90-100ml. o C. Stir for 1 hour. Introduce HCl gas until the pressure reaches 0.1 MPa. Maintain the temperature and stir for 1 hour. After purging with nitrogen, cool to room temperature. Set aside for later use.

[0075] Accurately weigh 143g of chlorosulfonyl isocyanate into a four-necked flask, 25-30 o Add 17g of processed Aquivion P98 to temperature C, and heat to 90-100°C. oC. Slowly add 116.5 g of chlorosulfonic acid dropwise (at a rate of 200 g / h and a time of 0.58 h) into the reaction flask. After stirring at the temperature for 8 hours, distill to obtain 202.6 g of product, with a yield of 94.7%.

[0076] Example 4

[0077] Example 4 provides a catalyst reuse scheme for preparing dichlorosulfonylimide by reacting chlorosulfonyl isocyanate and chlorosulfonic acid with Nafion NR50 as an additive.

[0078] The plan is as follows:

[0079] Accurately weigh 143g of chlorosulfonyl isocyanate into a four-necked flask, 25-30 o Add 11.5g of processed Nafion NR50 to C and heat to 95-105°C. o C. Slowly add 116.5 g of chlorosulfonic acid dropwise (at a rate of 120 g / h and a time of 0.98 h) into the reaction flask. After stirring at the temperature for 8 hours, distill to obtain 204.0 g of product, with a yield of 95.3%.

[0080] After distillation, the mixture was cooled to room temperature, and the residue was added to 20g of ethanol and stirred for 1 hour, then filtered. The catalyst was dried, and the experiment was repeated 10 times. The results are as follows:

[0081] Table 1

[0082] Number of passes Chlorosulfonic acid isocyanate Chlorosulfonic acid Product amount Yield 1 143g 116.5g 204.1 95.4% 2 143g 116.5g 203.8 95.2% 3 143g 116.5g 203.6 95.1% 4 143g 116.5g 203.7 95.2% 5 143g 116.5g 203.9 95.3% 6 143g 116.5g 203.5 95.1% 7 143g 116.5g 203.9 95.3% 8 143g 116.5g 204.0 95.3% 9 143g 116.5g 204.2 95.4% 10 143g 116.5g 204.0 95.3%

[0083] Example 5

[0084] Example 5 provides a catalyst reuse scheme for preparing dichlorosulfonylimide by reacting chlorosulfonyl isocyanate and chlorosulfonic acid with Nafion SAC-13 as an additive.

[0085] The plan is as follows:

[0086] Accurately weigh 143g of chlorosulfonyl isocyanate into a reaction flask, and heat for 25-30 minutes. o Add 23.3g of processed Nafion SAC-13 to temperature C and heat to 100-110°C. o C. Slowly add 116.5 g of chlorosulfonic acid dropwise (at a rate of 150 g / h and a time of 0.78 h) into the reaction flask. After stirring and maintaining the temperature for 8 hours, distill to obtain 203.8 g of the product, with a yield of 95.2%.

[0087] After distillation and cooling to room temperature, the residue in the still was added to 40g of ethanol and stirred for 1 hour, then filtered. The catalyst was dried, and the experiment was repeated 10 times. The results are as follows:

[0088] Table 2

[0089] Number of passes Chlorosulfonic acid isocyanate Chlorosulfonic acid Product amount Yield 1 143g 116.5g 203.5 95.0% 2 143g 116.5g 203.8 95.2% 3 143g 116.5g 203.5 95.0% 4 143g 116.5g 203.6 95.1% 5 143g 116.5g 203.9 95.3% 6 143g 116.5g 203.7 95.2% 7 143g 116.5g 203.6 95.1% 8 143g 116.5g 203.4 95.0% 9 143g 116.5g 204.0 95.3% 10 143g 116.5g 203.8 95.2%

[0090] Example 6

[0091] Example 6 provides a catalyst reuse scheme for preparing dichlorosulfonylimide by reacting chlorosulfonyl isocyanate and chlorosulfonic acid with Aquivion P98 as an additive.

[0092] The plan is as follows:

[0093] Accurately weigh 143g of chlorosulfonyl isocyanate into a four-necked flask, 25-30 o Add 17g of processed Aquivion P98 to temperature C, and heat to 90-100°C. o C. Slowly add 116.5 g of chlorosulfonic acid dropwise (at a rate of 200 g / h and a time of 0.58 h) into the reaction flask. After stirring at the temperature for 8 hours, distill to obtain 202.6 g of product, with a yield of 94.7%.

[0094] After distillation, the mixture was cooled to room temperature, and the residue was added to 30g of ethanol and stirred for 1 hour, then filtered. The catalyst was dried, and the experiment was repeated 10 times. The results are as follows:

[0095] Table 3

[0096] Number of passes Chlorosulfonic acid isocyanate Chlorosulfonic acid Product amount Yield 1 143g 116.5g 202.5 94.6% 2 143g 116.5g 202.8 94.8% 3 143g 116.5g 202.3 94.5% 4 143g 116.5g 202.6 94.7% 5 143g 116.5g 202.7 94.7% 6 143g 116.5g 202.4 94.6% 7 143g 116.5g 202.6 94.7% 8 143g 116.5g 202.5 94.6% 9 143g 116.5g 202.2 94.5% 10 143g 116.5g 202.3 94.5%

[0097] Comparative Example 1

[0098] Comparative Example 1 is basically the same as Example 1, except that Nafion NR50 was not treated. Under the same conditions, 150.3g of product was obtained, with a yield of 70.2%.

[0099] Comparative Example 2

[0100] Comparative Example 2 is basically the same as Example 2, except that Nafion SAC-13 was not treated. Under the same conditions, 149.5g of product was obtained, with a yield of 69.9%.

[0101] Comparative Example 3

[0102] Comparative Example 3 is basically the same as Example 3, except that Aquivion P98 was not treated. Under the same conditions, 147.9g of product was obtained, with a yield of 69.1%.

[0103] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A pretreatment method for perfluorosulfonic acid resin, characterized in that, The preprocessing method includes the following steps: The perfluorosulfonic acid resin was heated to 90-100℃ under a vacuum of 9000-10000Pa, stirred for the first time, and then HCl gas was introduced to a certain pressure. After holding at the temperature for the second time and stirring, nitrogen was used to replace the resin, and then the resin was cooled to room temperature to obtain the pretreated perfluorosulfonic acid resin. The first stirring time is 1-2 hours; HCl gas is introduced to 0.01-0.1 MPa; the second stirring time is 1-2 hours after keeping warm.

2. A method for preparing dichlorosulfonylimide, characterized in that, The preparation method includes: Pretreated perfluorosulfonic acid resin was added to chlorosulfonyl isocyanate, heated, and then chlorosulfonic acid was added dropwise. The mixture was kept warm and stirred, and then distilled to obtain dichlorosulfonyl imide. The pretreated perfluorosulfonic acid resin is obtained by treating it using the pretreatment method for perfluorosulfonic acid resin as described in claim 1. The mass ratio of the chlorosulfonyl isocyanate to the pretreated perfluorosulfonic acid resin is 1:(0.08~0.20). The heating temperature is 90~110℃; the temperature for heat preservation and stirring is 90~110℃; and the heat preservation and stirring time is 7~9 hours.

3. The method for preparing dichlorosulfonylimide according to claim 2, characterized in that, Pretreated perfluorosulfonic acid resin is added to chlorosulfonyl isocyanate at 25~30℃.

4. The method for preparing dichlorosulfonylimide according to claim 2, characterized in that, The molar ratio of chlorosulfonyl isocyanate to chlorosulfonic acid is 1:(1~1.02).

5. The method for preparing dichlorosulfonylimide according to claim 2, characterized in that, The dropping rate is 100~200g / h, and the dropping time is 0.5~1h.

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