Method for detecting content of each substance in bis (chlorosulfonyl) imide acid synthetic liquid by ion chromatography

Abstract

The invention discloses a method for detecting the content of each substance in a bis (chlorosulfonyl) imide acid synthetic solution by ion chromatography. The method comprises the following steps: dissolving m g of a bis (chlorosulfonyl) imide acid synthetic solution obtained by reacting chlorosulfonic acid, thionyl chloride and sulfamic acid as raw materials in cold water in a closed container, fully shaking the closed container, heating to fully hydrolyze each component, detecting a sample by using ion chromatography after complete hydrolysis, and determining the content of the bis (chlorosulfonyl) imide acid. According to the contents of Cl <->, SO4 < 2-> and NH2SO3 <-> detected by ion chromatography, the mole numbers of n (A), n (B), n (C) and n (D) are calculated, and finally the proportions of the four substances in the synthetic liquid are calculated according to the mole numbers of the four substances A, B, C and D, and the calculation formula is as follows: W (A) = n (A) * 214 / m (sample), W (B) = n (B) * 116 / m (sample), W (C) = n (C) * 119 / m (sample) and W (D) = n (D) * 116 / m (sample), A represents bis (chlorosulfonyl) imide acid, B represents chlorosulfonic acid, C represents thionyl chloride, and D represents aminosulfonyl chloride.

Description

Technical Field

[0001] This invention belongs to the field of ion chromatography detection, specifically relating to a method for detecting the content of various substances in a dichlorosulfonylimine synthesis solution using ion chromatography. Background Technology

[0002] Currently, lithium bisfluorosulfonyl imide (LiFSI) is recognized as a strategic-grade electrolyte lithium salt in the field of new energy materials. Its importance lies in its comprehensive superiority over traditional lithium hexafluorophosphate (LiPF6): First, LiFSI has an ionic conductivity that is about 20%-40% higher than LiPF6, maintaining efficient ion migration over a wide temperature range of -40℃ to 60℃, enabling batteries to charge and discharge rapidly even in extremely cold or high-temperature environments. Second, its thermal decomposition temperature is higher than 200℃, far exceeding the 80℃ of LiPF6, significantly suppressing high-temperature gas expansion and side reactions, and improving the battery's thermal runaway threshold. Third, LiFSI has extremely low corrosivity to aluminum foil current collectors and is compatible with high-nickel cathodes (NCM811, NCMA), silicon-based anodes, and solid electrolytes, helping to break through the energy density barrier of 350 Wh / kg. -1 Meanwhile, its low viscosity and high solubility characteristics reduce the amount of electrolyte used, lower the internal resistance of the system, support fast charging above 4C, and extend the cycle life to more than 1,500 times. In energy storage power stations, high-end consumer electronics and next-generation solid-state batteries, LiFSI has been listed as a core supply chain material by CATL, LG New Energy, Tesla and others. The global demand is expected to grow at a compound annual growth rate of more than 50% in the next five years.

[0003] The mainstream synthesis process of LiFSI currently consists of three steps: (1) Synthesis of dichlorosulfonylimine (abbreviated as dichloro acid); (2) Using a fluorinating agent to synthesize difluorosulfonyl imide acid; (3) Use lithium hydroxide or lithium carbonate as raw materials to synthesize LiFSI.

[0004] In the first step of synthesis, dichlorosulfonylimide is synthesized from three substances: aminosulfonic acid, chlorosulfonic acid, and thionyl chloride. Therefore, the dichlorosulfonylimide synthesis solution contains four components: dichlorosulfonylimide, chlorosulfonic acid, thionyl chloride, and aminosulfonyl chloride. In the LiFSI synthesis process, Cl... - SO4 2- NH2SO3 - The presence of [a substance] can severely affect its performance, and in severe cases, can lead to problems such as battery fires and harm to users. Therefore, the first step in LiFSI synthesis needs to address the [issue] of Cl [substance]. - SO4 2- NH2SO3 -Strict control necessitates rigorous testing of the contents of four substances: dichlorosulfonylimide, chlorosulfonic acid, thionyl chloride, and aminosulfonyl chloride. However, current testing methods only detect the contents of dichlorosulfonylimide and chlorosulfonic acid; there is no suitable method for simultaneously detecting all four substances. Therefore, this patent provides an ion chromatography method for determining the contents of each substance in a dichlorosulfonylimide acid synthesis solution. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for detecting the content of various substances in a dichlorosulfonylimine synthesis solution by ion chromatography.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for determining the content of various substances in a dichlorosulfonylimine synthesis solution by ion chromatography, the process of which is as follows: Take mg of the dichlorosulfonylimine synthesis solution obtained from the reaction of chlorosulfonic acid, thionyl chloride, and aminosulfonic acid as raw materials, dissolve it in cold water at 0-4℃ in a sealed container, then shake the sealed container thoroughly and heat it in a water bath at 80-90℃ for 5-10 hours to ensure complete hydrolysis of each component. After complete hydrolysis, perform sample detection using ion chromatography, based on Cl... - SO4 2- NH2SO3 - Substituting the peak area into the standard curve equation yields Cl - SO4 2- NH2SO3 - The concentration (ppm) of Cl - SO4 2- NH2SO3 - Calculate n from the concentration (ppm) （ Cl - ） n （ SO4 2- ） and n （ NH2SO3 - ） n （ Cl - ） n （ SO4 2- ） and n （ NH2SO3 - ） Represents n （ Cl - ） n （ SO4 2- ） and n （NH2SO3 - ） The number of moles, in mol, is calculated using equations (1), (2), (3), and (4). （ A ） n （ B ） n （ C ） n （ D ） The value of n （ A ） n （ B ） n （ C ） n （ D ） This represents the number of moles of four substances, A, B, C, and D, in mol. n （ A ） = [113n （ SO4 2- ） +3n （ Cl - ） +113n （ NH2SO3 - ） -m] / 18 (1) n （ B ） = 2n （ SO4 2- ） - n （ Cl - ） +n （ NH2SO3 - ） - n （ A ） (2) n （ C ） = n （ Cl - ） - n （ NH2SO3 - ） - n （ SO4 2- ） (3) n （ D ） = n （ NH2SO3 - ） - n（ A ） (4) Finally, the proportion of substances A, B, C, and D in the synthesis solution is calculated based on their molar amounts, as shown in the following formula: W （A） =n （ A ） *214 / m （样） ×100% (5) W （B） =n （ B ） *116 / m （样） ×100% (6) W （C） =n （ C ） *119 / m （样） ×100% (7) W （D） =n （ D ） *116 / m （样） ×100% (8) In this context, A represents dichlorosulfonylimide acid, B represents chlorosulfonic acid, C represents thionyl chloride, and D represents aminosulfonyl chloride.

[0007] Furthermore, the conditions for ion chromatography detection are as follows: Preparation of regenerated solution: Dilute 2.27 mL of methanesulfonic acid into a 1000 mL volumetric flask, add water to make up to the final volume, and obtain the regenerated solution.

[0008] Preparation of rinsing solution: Preparation of 1000mM sodium carbonate stock solution: Weigh 10.599g of sodium carbonate, add it to a 100mL volumetric flask, and dilute to volume and shake well.

[0009] Preparation of 1000mM sodium bicarbonate stock solution: Weigh 8.401g of sodium bicarbonate, add it to a 100mL volumetric flask, and dilute to volume and shake well.

[0010] Preparation of phase A eluent: Pipette 4.5 mL of 1000 mM sodium carbonate stock solution and 1 mL of 1000 mM sodium bicarbonate stock solution into a 1000 mL volumetric flask, make up to volume and shake well to obtain phase A eluent.

[0011] Preparation of phase B eluent: Pipette 10 mL of 1000 mM sodium carbonate stock solution and 400 mL of acetonitrile into a 500 mL volumetric flask, dilute to volume and shake well to obtain phase B eluent.

[0012] The eluent phases A and B need to be degassed using filters.

[0013] Washing conditions: The chromatographic column was a Metrosep A Supp 5 type column, with a length of 250 mm and an inner diameter of 4.0 mm; During detection, the regeneration solution flow rate was 1.0~1.5 mL / min, the eluent flow rate was 0.5~1.0 mL / min, the injection volume was 200 μL, and the column temperature was 40℃.

[0014] The detection system is a conductivity detector.

[0015] Furthermore, the standard curve equation is obtained through the following process: purchasing Cl with a concentration ≥200ppm. - SO4 2- NH2SO3 - The primary standard reagent is diluted with water to make Cl - SO4 2- NH2SO3 - The concentration gradient was in the range of 10-200 ppm, and ion chromatography was used to detect Cl at different concentrations. - SO4 2- NH2SO3 - The peak area of ​​Cl was used to construct a standard curve with ion concentration on the x-axis and ion peak area on the y-axis to obtain Cl. - SO4 2- NH2SO3 - The standard curve equation.

[0016] Furthermore, Cl - The standard curve equation is y = 2.6096x + 7.6317, SO4 2- The standard curve equation is y = 1.7856x + 6.0471, NH2SO3 - The equation of the standard curve is y = 0.9780x + 1.2404.

[0017] Furthermore, the concentration of the dichlorosulfonyl imide acid synthesis solution in cold water at 0-4°C is 0.1~1wt%.

[0018] Furthermore, the sealed container is a PFA bottle, a polytetrafluoroethylene bottle, a PP bottle, etc., with PFA bottles being preferred.

[0019] This application utilizes ion chromatography to determine the content of each substance in the synthesis solution of dichlorosulfonylimine, with small detection deviation and low detection limit. Attached Figure Description

[0020] Figure 1This is a chromatogram of dichlorosulfonylimide ion detection. The three chromatographic peaks from left to right are NH2SO3. - Cl - SO4 2- ; Figure 2 For Cl - The standard curve; Figure 3 SO4 2- The standard curve; Figure 4 NH2SO3 - The standard curve. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited thereto.

[0022] Note A: Dichlorosulfonylimine (molecular formula: NH(SO2Cl)2, molecular weight: 214 g / mol, anion upon complete hydrolysis is Cl-) - SO4 2- NH2SO3 - ); {A → 2 Cl - + SO4 2- + NH2SO3 -}; B: Chlorosulfonic acid (molecular formula: ClSO3H, molecular weight: 116.53 g / mol, anion upon complete hydrolysis is Cl-). - SO4 2- ) {B → Cl - + SO4 2-}; C: Thionyl chloride (molecular formula: Cl₂SO₄, molecular weight: 119 g / mol, anion is Cl₂ upon complete hydrolysis) - SO4 2- ); {C → 2 Cl - + SO4 2-}; D: Aminosulfonyl chloride (molecular formula: NH₂SO₂Cl, molecular weight: 115.55 g / mol, anion upon complete hydrolysis is Cl₂) - NH2SO3 - ) {D → Cl - + NH2SO3 -}

[0023] In a sealed container, mg of dichlorosulfonylimide acid synthesis solution sample was dissolved in water. Under sufficient time and at a specific temperature, dichlorosulfonylimide acid, chlorosulfonic acid, aminosulfonyl chloride, and sulfoxide were allowed to undergo a complete hydrolysis reaction to generate chloride ions (Cl). - ), sulfate ions (SO4) 2- ) and aminosulfonate ions (NH2SO3) - The anion content of the completely hydrolyzed dichlorosulfonylimide acid synthesis solution was detected using ion chromatography. - SO4 2- NH2SO3 - The content of Cl in ion chromatography related operations - SO4 2- NH2SO3 - The main steps for establishing the external standard curve are as follows: Purchase Cl at a concentration of 10000ppm - SO4 2- NH2SO3 - The primary standard reagent is diluted with water to a concentration that makes Cl... - SO4 2- NH2SO3 - The concentrations were 10, 20, 50, 100, and 200 ppm, and then ion chromatography was used to detect the Cl concentrations at different levels. - SO4 2- NH2SO3 - The peak area.

[0024] The conditions for ion chromatography detection are as follows: The suppressor model is the ACRS-500 chemical regenerative anion suppressor manufactured by Thermo Fisher Scientific. The chromatographic column was a Metrosep A Supp 5 type column, the stationary phase was polyvinyl alcohol-quaternary ammonium anion exchange resin, the column length was 250 mm, and the inner diameter was 4.0 mm; The detection system is a conductivity detector.

[0025] During detection, the regeneration solution flow rate was 1.2 mL / min, the eluent flow rate was 0.7 mL / min, the injection volume was 200 μL, the column temperature was 40℃, and the conductivity cell temperature was 35℃.

[0026] Preparation of regenerated solution: Dilute 2.27 mL of methanesulfonic acid into a 1000 mL volumetric flask, add water to make up to the final volume, and obtain the regenerated solution.

[0027] Preparation of rinsing solution: Preparation of 1000mM sodium carbonate stock solution: Weigh 10.599g of sodium carbonate, add it to a 100mL volumetric flask, and dilute to volume and shake well.

[0028] Preparation of 1000mM sodium bicarbonate stock solution: Weigh 8.401g of sodium bicarbonate, add it to a 100mL volumetric flask, and dilute to volume and shake well.

[0029] Preparation of phase A eluent: Pipette 4.5 mL of 1000 mM sodium carbonate stock solution and 1 mL of 1000 mM sodium bicarbonate stock solution into a 1000 mL volumetric flask, make up to volume and shake well to obtain phase A eluent.

[0030] Preparation of phase B eluent: Pipette 10 mL of 1000 mM sodium carbonate stock solution and 400 mL of acetonitrile into a 500 mL volumetric flask, dilute to volume and shake well to obtain phase B eluent.

[0031] The eluent phases A and B need to be degassed using filters.

[0032] Washing conditions: A standard curve was plotted with ion concentration on the x-axis and ion peak area on the y-axis to obtain Cl. - SO4 2- NH2SO3 - The standard curve equation is given. See the results for details. Figures 2 to 4 Used to detect Cl in unknown substances - SO4 2- NH2SO3 - The concentration of Cl - The standard curve equation is y = 2.6096x + 7.6317, R0 2 =0.9994, SO4 2- The standard curve equation is y = 1.7856x + 6.0471, R0 2 =0.9992, NH2SO3 - The standard curve equation is y = 0.9780x + 1.2404, R0 2 =1.0000.

[0033] Limit of detection: The detection limits for each ion were calculated using the 3σ method. For chloride ions, the intercept of 7.6317 was used as the blank response value, the slope was 2.6096, and the relative standard deviation (RSD) was calculated with 5% as follows: 3σ≈3×7.6317×5%÷2.6096≈0.44ppm, indicating that the detection limit of chloride ions is 0.44ppm. For sulfate ions, the intercept of 6.0471 was used as the blank response value, the slope was 1.7856, and the relative standard deviation (RSD) was calculated with 5% as follows: 3σ≈3×6.0471×5%÷1.7856≈0.51ppm, indicating that the detection limit of sulfate ions is 0.51ppm. For aminosulfonate, using an intercept of 1.2404 as the blank response value and a slope of 0.9780, the relative standard deviation (RSD) was calculated with 5% as follows: 3σ≈3×1.2404×5%÷0.9780≈0.19ppm, indicating that the detection limit for aminosulfonate ions is 0.19ppm.

[0034] When the concentration of each ion entering the chromatographic column is greater than its corresponding detection limit, it indicates that the ion can be detected under the corresponding detection conditions.

[0035] When all substances in the sample are completely hydrolyzed, the following relationship exists: For compound A: n （ Cl - ） = 2n （ A ） n （ SO4 2- ） = n （ A ） n （ NH2SO3 - ） = n （ A ） For compound B: n （ Cl - ） = n （ B ） n （ SO4 2- ） = n （ B ） For compound C: n （ Cl - ） = 2n （ C ） n （ SO4 2- ） = n （ C） For compound D: n （ Cl - ） = n （ D ） n （ NH2SO3 - ） = n （ D ） When compounds A, B, C, and D are completely hydrolyzed, the following four equations can be written: ①n （ Cl - ） = 2n （ A ） + n （ B ） + 2n （ C ） + n （ D ） ②n （ SO4 2- ） = n （ A ） + n （ B ） + n （ C ） ③n （ NH2SO3 - ） = n （ A ） + n （ D ） ④m = 214n （ A ） + 116n （ B ） + 119n （ C ） + 116n （ D ） To simplify the calculation process, the molecular weights of compounds B and D are both calculated as "116 g / mol".

[0036] Solve equations ①, ②, ③, and ④ simultaneously, and then, based on the Cl detected by ion chromatography... - SO4 2- NH2SO3 - The content of n is calculated.（ A ） n （ B ） n （ C ） n （ D ） The value of is calculated as follows: n （ A ） = [113n （ SO4 2- ） +3n （ Cl - ） +113n （ NH2SO3 - ） -m] / 18 (1) n （ B ） = 2n （ SO4 2- ） - n （ Cl - ） +n （ NH2SO3 - ） - n （ A ） (2) n （ C ） = n （ Cl - ） - n （ NH2SO3 - ） - n （ SO4 2- ） (3) n （ D ） = n （ NH2SO3 - ） - n （ A ） (4) Finally, the proportion of substances A, B, C, and D in the synthesis solution is calculated based on their molar amounts, as shown in the following formula: W （A） =n （ A ） *214 / m （样） (5) W （B） =n （B ） *116 / m （样） (6) W （C） =n （ C ） *119 / m （样） (7) W （D） =n （ D ） *116 / m （样） (8) Finally, based on the above calculation formula and the Cl measured by ion chromatography, - SO4 2- NH2SO3 - The data can be used to calculate the content of dichlorosulfonamide, chlorosulfonic acid, thionyl chloride, and aminosulfonic acid.

[0037] 1. Prepare a standard solution 1 (5g by mass) containing 5% chlorosulfonic acid, 10% thionyl chloride, 2% aminosulfonyl chloride, and 83% dichlorosulfonylimide acid. Divide the standard solution 1 into five equal portions, each weighing 1g, and label them R1, R2, R3, R4, and R5. Dissolve each portion in 500g of cold water at 0-4℃ in a sealed container (the purpose of using cold water is to minimize the amount of HCl gas generated upon initial contact with the water, thus reducing the chloride concentration). - (Detection error), then shake the sealed container thoroughly to ensure the small amount of HCl gas generated is fully absorbed, and heat in a water bath at 80-90℃ for 5-10 hours to fully hydrolyze each component. After complete hydrolysis, the sample is detected using ion chromatography, and calculations are performed according to the above formula. The calculation results are summarized in Table 1.

[0038] 2. Prepare a standard solution 2 containing 5g of 10% chlorosulfonic acid, 8% thionyl chloride, 2% aminosulfonic acid, and 80% dichlorosulfonylimide. Divide the standard solution 2 into five equal portions, each weighing 1g, and label them Q1, Q2, Q3, Q4, and Q5. Dissolve each portion in 500g of cold water at 0-4℃ in a sealed container (the purpose of using cold water is to minimize the amount of HCl gas generated upon initial contact with the water, thus reducing the Cl- concentration). - (Detection error), then shake the sealed container thoroughly to ensure the small amount of HCl gas generated is fully absorbed, and heat in a water bath at 80-90℃ for 5-10 hours to fully hydrolyze each component. After complete hydrolysis, the sample is detected using ion chromatography, and calculations are performed according to the above formula. The calculation results are summarized in Table 1.

[0039] 3. Prepare a 5g standard solution containing 15% chlorosulfonic acid, 15% thionyl chloride, 1% aminosulfonic acid, and 69% dichlorosulfonylimide. Divide the standard solution into five equal portions, each weighing 1g, and label them Y1, Y2, Y3, Y4, and Y5. Dissolve each portion in 500g of cold water at 0-4℃ in a sealed container (the purpose of using cold water is to minimize the amount of HCl gas generated upon initial contact with the water, thus reducing the Cl- concentration). - (Detection error), then shake the sealed container thoroughly to ensure the small amount of HCl gas generated is fully absorbed, and heat in a water bath at 80-90℃ for 5-10 hours to fully hydrolyze each component. After complete hydrolysis, the sample is detected using ion chromatography, and calculations are performed according to the above formula. The calculation results are summarized in Table 1.

[0040] 4. Prepare a 5g standard solution containing 30% chlorosulfonic acid, 40% thionyl chloride, 1% aminosulfonic acid, and 29% dichlorosulfonylimide. Divide the standard solution into five equal portions, each weighing 1g, and label them M1, M2, M3, M4, and M5. Dissolve each portion in 500g of cold water at 0-4℃ in a sealed container (the purpose of using cold water is to minimize the amount of HCl gas generated upon initial contact with the water, thus reducing the Cl- concentration). - (Detection error), then shake the sealed container thoroughly to ensure the small amount of HCl gas generated is fully absorbed, and heat in a water bath at 80-90℃ for 5-10 hours to fully hydrolyze each component. After complete hydrolysis, the sample is detected using ion chromatography, and calculations are performed according to the above formula. The calculation results are summarized in Table 1.

[0041] 5. Take 1g of the dichlorosulfonylimine synthesis solution obtained from the reaction of chlorosulfonic acid, thionyl chloride, and aminosulfonic acid as raw materials, dissolve it in 500g of cold water at 0-4℃ in a sealed container, then shake the sealed container thoroughly to ensure that the small amount of HCl gas generated is fully absorbed, and heat in a water bath at 80-90℃ for 5-10 hours to fully hydrolyze each component. After complete hydrolysis, perform sample detection using ion chromatography, substitute the corresponding ion peak areas into the standard curve equation to obtain the concentration of each ion, and the detection results are as follows: The chloride ion concentration was 358,791 ppm (μg / g), the sulfate ion concentration was 510,698 ppm (μg / g), and the aminosulfonate ion concentration was 368,555 ppm (μg / g).

[0042] The molar amount of each ion is calculated by dividing the ion concentration by its relative molecular weight. The molar amount of chloride ion is 10.11 × 10⁻⁶. -3 The molar amount of sulfate ions is 5.32 × 10⁻⁶ mol. -3 The molar amount of aminosulfonate ions is 3.84 × 10⁻⁶ mol. -3mol.

[0043] The molar amount of dichlorosulfonylimide acid calculated from equations (1), (2), (3), and (4) is 3.63 × 10⁻⁶. -3 The molar amount of chlorosulfonic acid is 0.74 × 10⁻⁶ mol. -3 The molar amount of thionyl chloride is 0.95 × 10⁻⁶ mol. -3 The molar amount of aminosulfonyl chloride is 0.21 × 10⁻⁶ mol. -3 mol.

[0044] Finally, based on equations (5), (6), (7) and (8), the proportions of each substance were calculated as follows: dichlorosulfonyl imide acid accounted for 77.68%, chlorosulfonic acid accounted for 8.58%, thionyl chloride accounted for 11.3%, and aminosulfonyl chloride accounted for 2.44%.

[0045] Table 1 Test Results of Standard Solution 1 Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the specific implementation of the present invention and not to limit it. Those skilled in the art should understand that any equivalent substitutions or obvious modifications made to the implementation of the present invention without changing its performance or use, without departing from the spirit of the present invention, should be covered within the scope of protection claimed by the present invention.

Claims

1. A method for determining the content of various substances in a dichlorosulfonylimine synthesis solution by ion chromatography, characterized in that, The process is as follows: Take mg of the dichlorosulfonylimine synthesis solution obtained from the reaction of chlorosulfonic acid, thionyl chloride, and aminosulfonic acid as raw materials, dissolve it in cold water at 0-4℃ in a sealed container, then shake the sealed container thoroughly and heat it in a water bath at 80-90℃ for 5-10 hours to ensure complete hydrolysis of each component. After complete hydrolysis, perform sample detection using ion chromatography, based on Cl... - SO4 2- NH2SO3 - Substituting the peak area into the standard curve equation yields Cl - SO4 2- NH2SO3 - The concentration (ppm) of Cl - SO4 2- NH2SO3 - Calculate n from the concentration (ppm) （ Cl - ） n （ SO4 2- ） and n （ NH2SO3 - ） n （ Cl - ） n （ SO4 2- ） and n （ NH2SO3 - ） Represents n （ Cl - ） n （ SO4 2- ） and n （ NH2SO3 - ） The number of moles, in mol, is calculated using equations (1), (2), (3), and (4). （ A ） n （ B ） n （ C ） n （ D ） The value of n （ A ） n （ B ） n （ C ） n （ D ） This represents the number of moles of four substances, A, B, C, and D, in mol. n （ A ） = [113n （ SO4 2- ） +3n （ Cl - ） +113n （ NH2SO3 - ） -m] / 18 (1) n （ B ） = 2n （ SO4 2- ） - n （ Cl - ） +n （ NH2SO3 - ） - n （ A ） (2) n （ C ） = n （ Cl - ） - n （ NH2SO3 - ） - n （ SO4 2- ） (3) n （ D ） = n （ NH2SO3 - ） - n （ A ） (4) Finally, the proportion of substances A, B, C, and D in the synthesis solution is calculated based on their molar amounts, as shown in the following formula: W （A） =n （ A ） *214 / m （样） ×100% (5) W （B） =n （ B ） *116 / m （样） ×100% (6) W （C） =n （ C ） *119 / m （样） ×100% (7) W （D） =n （ D ） *116 / m （样） ×100% (8) In this context, A represents dichlorosulfonylimide acid, B represents chlorosulfonic acid, C represents thionyl chloride, and D represents aminosulfonyl chloride.

2. The method for detecting the content of various substances in the synthesis solution of dichlorosulfonylimide acid by ion chromatography according to claim 1, characterized in that, The conditions for ion chromatography detection are as follows: Preparation of regenerated solution: Dilute 2.27 mL of methanesulfonic acid to a 1000 mL volumetric flask, add water to make up to volume, and obtain the regeneration solution; Preparation of rinsing solution: Preparation of 1000mM sodium carbonate stock solution: Weigh 10.599g of sodium carbonate, add it to a 100mL volumetric flask, dilute to volume and shake well. Preparation of 1000mM sodium bicarbonate stock solution: Weigh 8.401g of sodium bicarbonate, add it to a 100mL volumetric flask, dilute to volume and shake well. Preparation of phase A eluent: Pipette 4.5 mL of 1000 mM sodium carbonate stock solution and 1 mL of 1000 mM sodium bicarbonate stock solution into a 1000 mL volumetric flask, make up to volume and shake well to obtain phase A eluent. Preparation of phase B eluent: Pipette 10 mL of 1000 mM sodium carbonate stock solution and 400 mL of acetonitrile into a 500 mL volumetric flask, dilute to volume and shake well to obtain phase B eluent; Both phases A and B of the eluent need to be degassed using filters; Washing conditions: 。 3. The method for detecting the content of various substances in the synthesis solution of dichlorosulfonylimide acid by ion chromatography according to claim 2, characterized in that, The conditions for ion chromatography detection are as follows: The chromatographic column was a Metrosep A Supp 5 type column, with a length of 250 mm and an inner diameter of 4.0 mm; During detection, the regeneration solution flow rate is 1.0~1.5 mL / min, the eluent flow rate is 0.5~1.0 mL / min, the injection volume is 150~250 μL, and the column temperature is 35~45℃.

4. The method for detecting the content of various substances in the synthesis solution of dichlorosulfonylimide acid by ion chromatography according to claim 1, characterized in that, The standard curve equation is obtained through the following process: Purchase Cl with a concentration ≥200ppm. - SO4 2- NH2SO3 - The primary standard reagent is diluted with water to make Cl - SO4 2- NH2SO3 - The concentration gradient was in the range of 10-200 ppm, and ion chromatography was used to detect Cl at different concentrations. - SO4 2- NH2SO3 - The peak area of ​​Cl was used to construct a standard curve with ion concentration on the x-axis and ion peak area on the y-axis to obtain Cl. - SO4 2- NH2SO3 - The standard curve equation.

5. The method for detecting the content of various substances in the synthesis solution of dichlorosulfonylimide acid by ion chromatography according to claim 4, characterized in that, Cl - The standard curve equation is y = 2.6096x + 7.6317, SO4 2- The standard curve equation is y = 1.7856x + 6.0471, NH2SO3 - The equation of the standard curve is y = 0.9780x + 1.2404.

6. The method for detecting the content of various substances in the synthesis solution of dichlorosulfonylimide acid by ion chromatography according to claim 1, characterized in that, The concentration of the dichlorosulfonyl imide synthesis solution in cold water at 0-4℃ is 0.1-1wt%.

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