Preparation method and application of ethylene sulfite compound

Abstract

The invention relates to a preparation method and application of an ethylene sulfite compound, and the preparation method comprises the step of reacting an epoxy compound with sulfur dioxide under the action of an immobilized organic base catalyst to obtain the ethylene sulfite compound. The immobilized organic base catalyst is formed by connecting organic base and chloromethylated resin through chemical bonds, and has good catalytic activity and chemical stability. According to the preparation method provided by the invention, the raw material cost is low, the product is easy to purify, the yield is relatively high, continuous automatic production is easy to realize, and the prepared ethylene sulfite compound is added into the lithium battery electrolyte as an additive, so that the electrochemical window of an electrolyte system can be widened, and the high-voltage interface stability and the cycle performance of the battery can be improved.

Description

Technical Field

[0001] This invention belongs to the field of new energy battery electrolyte additive synthesis technology, and particularly relates to a method for preparing and applying a vinyl sulfite compound. Background Technology

[0002] Vinyl sulfite compounds are important organic chemical raw materials, used as reducing agents in dyes and chemical reagents, and as binders. They are also widely used as hydroxyethylating agents in organic synthesis, as intermediates in pharmaceutical synthesis, and as important intermediates in the preparation of cyclic vinyl sulfate compounds. Furthermore, vinyl sulfite compounds can be used as solvents or additives in lithium-ion secondary battery electrolytes, inhibiting the decline in initial battery capacity, increasing initial discharge capacity, reducing battery swelling after high-temperature storage, and improving battery charge-discharge performance and cycle life.

[0003] Currently, the main methods for preparing vinyl sulfite compounds include the reaction of ethylene glycol with thionyl chloride, the addition of ethylene oxide with sulfur dioxide, the transesterification of ethylene glycol with sulfite, and the depolymerization of polyethylene glycol sulfite. US2413405A discloses an isomerized product of vinyl sulfite that is completely volatile at room temperature and can be used as an insecticide. GB670159A and DE888770C disclose the conversion of an intermediate oxonium compound obtained from sulfur dioxide and ethylene oxide into vinyl sulfite through isomerization and polymerization reactions under the action of amine and amide catalysts, followed by decomposition at high temperature to obtain monomeric vinyl sulfite. However, this preparation process is complex, requires cumbersome conditions, produces many byproducts, and has a low yield. GB783561A discloses the preparation of ethylene glycol sulfite from ethylene oxide and sulfur dioxide at 130–170 °C and 0.4–2.5 MPa. To further improve reaction rate and efficiency, CN101210007A discloses the use of aluminum halides as catalysts, and CN101210008A discloses the use of complexes formed from polyethylene glycol and metal halides; however, the reaction conditions are quite harsh, requiring equipment such as autoclaves. CN115745952A discloses a reaction in imidazole ionic liquids, which requires the use of metal halides as co-catalysts. CN117258838A discloses the use of a specific ratio of hydrocarbon boranes and nitrogen-containing organic compounds as catalysts. All of the above catalysts are combined catalysts, which are costly, and the separation of the final product is difficult.

[0004] Therefore, developing new catalytic reaction systems, mild reaction conditions, environmentally friendly processes, and easily automated continuous production methods for the preparation of vinyl sulfite compounds still has significant application value. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for preparing vinyl sulfite compounds and their applications. The supported organic base catalyst used in the preparation method has good chemical stability, mild reaction conditions, high catalytic activity, and is easy to recycle. The product is easy to separate and purify, and the process can be made continuous.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing vinyl sulfite compounds, the method comprising the following steps: reacting an epoxy compound and sulfur dioxide under the action of a supported organic base catalyst to obtain vinyl sulfite compounds;

[0008] The vinyl sulfite compounds have the following general structural formula:

[0009]

[0010] Among them, R 1 R 2 R 3 and R 4 Each is independently selected from hydrogen atoms, alkyl groups having 1 to 8 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8), cycloalkyl groups having 3 to 8 carbon atoms (e.g., 3, 4, 5, 6, 7, 8), alkenyl, alkynyl, aryl, substituted aryl, hydroxyl, or fluorinated alkyl groups.

[0011] The preparation method of the above-mentioned vinyl sulfite compounds can be represented by the following general reaction formula:

[0012]

[0013] This invention utilizes a specific structured supported organic base to catalyze the reaction of sulfur dioxide and epoxides to prepare cyclic vinyl sulfite compounds. The supported organic base catalyst exhibits good chemical stability, high catalytic activity, and is easy to recycle. The products are also easy to separate and purify, enabling continuous processing.

[0014] Preferably, the supported organic base catalyst comprises any one or a combination of at least two of the following: polystyrene-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (PS-TBD), polystyrene-supported dimethylaminopyridine (PS-DMAP), polystyrene-supported 1,8-diazabicyclo[5.4.0]undec-7-ene (PS-DBU), or polystyrene-supported 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphide (PS-BEMP).

[0015] Preferably, the supported organic base catalyst can be purchased commercially and used directly, or it can be prepared by amination reaction of chloromethylated polystyrene resin microspheres with organic base precursors such as aminophosphonamide derivatives, 4-methylaminopyridine, and 1,5,7-triazabicyclobenzene.

[0016] Preferably, the supported organic base catalyst is formed by chemically linking chloromethylated polystyrene resin and an organic base. The amount of organic base in the supported organic base catalyst is 1 to 5 mmol relative to 1g of polymer, for example, 1 mmol, 2 mmol, 3 mmol, 4 mmol, 5 mmol, etc. The supported organic base catalyst has good catalytic activity and chemical stability.

[0017] The reaction process was monitored by gas chromatography until the raw material epoxide (Formula I) was completely converted. After the reaction, the reaction solution was filtered to recover the supported organic base catalyst. The filtrate was concentrated, followed by concentration, distillation, and other post-processing operations. The crude product, after vacuum distillation, achieved a purity of over 94%, with an overall product yield of over 80%. Further purification can increase the purity of the product to over 99.9%. The supported organic base catalyst can be recovered and reused, or it can be used in a fixed-bed reactor for continuous flow reactions, offering high economic and environmental benefits.

[0018] Preferably, the epoxy compound includes any one or a combination of at least two of ethylene oxide, propylene oxide, 1,2-dimethylethylene oxide, 1,1,1-trifluoro-2,3-propylene oxide, vinyl ethylene oxide, or dibutyronitrile.

[0019] Preferably, the molar ratio of the epoxide, sulfur dioxide, and supported organic base catalyst is 1:(1-5):(0.05-0.5), for example, it can be 1:1:0.05, 1:2:0.05, 1:3:0.05, 1:4:0.05, 1:5:0.05, 1:1:0.1, 1:1:0.2, 1:1:0.3, 1:1:0.4, 1:1:0.5, 1:2:0.1, 1:2 :0.2, 1:2:0.3, 1:2:0.4, 1:2:0.5, 1:3:0.1, 1:3:0.2, 1:3:0.3, 1:3:0.4, 1:3:0.5, 1:4:0.1, 1:4:0.2, 1:4:0.3, 1:4:0.4, 1:4:0.5, 1:5:0.1, 1:5:0.2, 1:5:0.3, 1:5:0.4, 1:5:0.5, etc.

[0020] Preferably, the amount of sulfur dioxide used depends on the number of epoxy groups in the epoxy compound. Each epoxy group requires at least 1 mole of sulfur dioxide. Usually, an excess of sulfur dioxide is used to ensure complete reaction and conversion of the epoxy compound, which facilitates the separation and purification of cyclic vinyl sulfite compounds.

[0021] Preferably, the reaction is considered complete when the content of epoxy compounds and incompletely reacted epoxy intermediates is less than 0.1% by gas chromatography to monitor the reaction process.

[0022] Preferably, the supported organic base catalyst can be recycled and reused, or it can be filled into a fixed-bed reactor for continuous flow reaction, which has high economic and environmental benefits.

[0023] Preferably, the amount of sulfur dioxide added is controlled so that the pressure of the reaction system is 0.1 to 0.4 MPa, for example, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, etc. Increasing the pressure is beneficial to the rapid progress of the reaction.

[0024] Preferably, the reaction temperature is 20 to 120°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, etc., and preferably 40 to 80°C.

[0025] Preferably, the reaction time is 2 to 24 hours, for example, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, etc.

[0026] Preferably, the reaction is carried out in a solvent.

[0027] Preferably, the supported organic base catalytic reaction is carried out by oscillation in a solvent, which helps to dissolve and disperse the reactants and to ensure sufficient contact and reaction of the active molecules on the surface of the supported organic base catalyst.

[0028] Preferably, the solvent includes any one or a combination of at least two of the following: acetonitrile, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, dichloromethane, dichloroethane, tetrachloroethane, dimethyl carbonate, diethyl carbonate, or methyl ethyl carbonate.

[0029] Preferably, the reaction further includes post-processing and product purification after completion.

[0030] Preferably, the preparation method includes the following steps: epoxide and sulfur dioxide react at 25-120°C and 0.1-0.4 MPa for 2-24 h under the action of a supported organic base catalyst, then cool to 20-25°C, filter to recover the supported organic base catalyst, and perform vacuum distillation on the filtrate to obtain cyclic vinyl sulfite compounds, wherein the molar ratio of epoxide, sulfur dioxide and supported organic base catalyst is 1:(1-5):(0.05-0.5).

[0031] In a second aspect, the present invention provides a vinyl sulfite compound prepared by the preparation method described in the first aspect.

[0032] Preferably, the vinyl sulfite compound has any one or a combination of at least two of the structures shown in formulas II-1 to II-10:

[0033]

[0034] Preferably, since no chlorine-containing materials such as thionyl chloride are used in the reaction process, the residual chloride ions in the vinyl sulfite compounds are low and easy to control. The purity of the product can be further improved to over 99.9% after purification, which meets the high purity requirements of lithium batteries for electrolyte additives.

[0035] Thirdly, the present invention provides an electrolyte additive, which includes the vinyl sulfite compounds described in the second aspect. Adding vinyl sulfite compounds as additives to lithium battery electrolytes can broaden the electrochemical window of the electrolyte system, improve the high-voltage interface stability of the battery, and improve the high-voltage cycle performance of the battery.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] 1) This invention uses a supported organic base to catalyze the reaction of sulfur dioxide and epoxy compounds to prepare cyclic vinyl sulfite compounds. The supported organic base catalyst has good chemical stability, high catalytic activity, and is easy to recycle.

[0038] 2) The preparation method provided by the present invention has low raw material cost, easy product purification, high yield, and is easy to realize continuous automated production. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of a supported organic base catalyst. Detailed Implementation

[0040] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0041] In the following embodiments, unless otherwise specified, all raw materials used are ordinary commercially available products that can be directly purchased or can be prepared using conventional techniques in the art.

[0042] Example 1

[0043] This embodiment provides a method for preparing vinyl sulfite compounds. 1 mol of ethylene oxide, 200 mL of tetrahydrofuran, and 50 g of 3.5 mmol / g polystyrene-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (PS-TBD) are added to a reaction vessel. SO2 is slowly and continuously introduced until the pressure inside the vessel reaches 0.2 MPa. The reaction is carried out at 50°C for 8 hours, then cooled to 20°C. Nitrogen gas is slowly introduced through the exhaust valve to release excess SO2. PS-TBD is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain 99.5 g of vinyl sulfite, with a product yield of 92%. Gas chromatography (Agilent 8860) analysis shows the product purity to be 99.6%.

[0044] Spectral characterization of vinyl sulfite:

[0045]

[0046] 1 H NMR (400MHz, CDCl3) δ: 4.65-4.56(m, 2H)ppm, 4.32-4.24(m, 2H)ppm; 13 C NMR (100MHz, CDCl3) δ: 67.2ppm.

[0047] Example 2

[0048] This embodiment provides a method for preparing vinyl sulfite compounds. 1.43 mol of ethylene oxide, 200 mL of tetrachloroethane, and 60 g of 3.5 mmol / g polystyrene-supported 1,8-diazabicyclo[5.4.0]undec-7-ene (PS-DBU) are added to a reaction vessel. SO2 is slowly and continuously introduced until the pressure inside the vessel reaches 0.3 MPa. The reaction is carried out at 60°C for 12 h, then cooled to 22°C. Nitrogen gas is slowly introduced through the exhaust valve to release excess SO2. PS-DBU is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain 165.5 g of 4-methylvinyl sulfite, with a product yield of 95%. Gas chromatography (Agilent 8860) analysis shows the product purity to be 99.4%.

[0049] Spectral characterization of 4-methylvinyl sulfite:

[0050]

[0051] 1 ¹H NMR (400MHz, CDCl₃) δ: The molar ratio of major to minor isomers was 1.74:1.00. Major isomer δ: 5.16-5.08 (m, 1H) ppm, 4.73-4.69 (dd, J = 8.4, 6.0 Hz, 1H) ppm, 3.90-3.86 (dd, J = 8.4, 7.2 Hz, 1H) ppm, 1.44 (d, J = 6.4 Hz, 3H) ppm; Minor isomer δ: 4.66-4.59 (m, 1H) ppm, 4.54-4.50 (dd, J = 8.0, 6.0 Hz, 1H) ppm, 4.31-4.27 (dd, J = 8.8, 8.4 Hz, 1H) ppm, 1.61 (dd, J = 6.4 Hz, 3H) ppm.

[0052] 13 C NMR (100MHz, CDCl3) Major isomers δ: 80.20, 72.76, 17.53 ppm; Minor isomers δ: 76.43, 71.20, 18.64 ppm.

[0053] Example 3

[0054] This embodiment provides a method for preparing vinyl sulfite compounds. 1.38 mol of 2,3-epoxybutane, 200 mL of tetrahydrofuran, and 50 g of 4 mmol / g polystyrene-supported dimethylaminopyridine (PS-DMAP) are added to a reaction vessel. SO2 is slowly and continuously introduced until the pressure inside the vessel reaches 0.4 MPa. The reaction is carried out at 80°C for 18 h, then cooled to 22°C. Nitrogen gas is slowly introduced through the exhaust valve to release excess SO2. PS-DMAP is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain 170 g of 4,5-dimethylvinyl sulfite, with a product yield of 90%. Gas chromatography (Agilent 8860) analysis shows the product purity to be 99.2%.

[0055] Spectral characterization of 4,5-dimethylvinyl sulfite:

[0056]

[0057] 1 ¹H NMR (400MHz, CDCl₃) showed a molar ratio of major to minor isomers of 3.0:1.7. Major isomer, δ: 4.99–4.92 (m, 2H) ppm, 1.25–1.21 (m, 6H) ppm; minor isomer, δ: 4.62–4.54 (m, 1H) ppm, 4.07–3.99 (m, 1H) ppm, 1.48–1.38 (m, 6H) ppm.

[0058] 13 C NMR (100MHz, CDCl3) major isomers, δ: 85.1, 78.4, 17.7, 14.1 ppm; minor isomers, δ: 80.9, 80.1, 15.9, 15.6 ppm.

[0059] Example 4

[0060] This embodiment provides a method for preparing vinyl sulfite compounds. 100g of 2,3-epoxypropanol, 200mL of acetonitrile, and 50g of 5.0mmol / g polystyrene-supported dimethylaminopyridine (PS-DMAP) are added to a reaction vessel. SO2 is slowly and continuously introduced until the pressure inside the vessel reaches 0.3MPa. The reaction is carried out at 70°C for 20h, then cooled to 25°C. Nitrogen gas is slowly introduced through the exhaust valve to release excess SO2. PS-DMAP is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain 150g of 4-hydroxymethyl vinyl sulfite, with a product yield of 80%. Gas chromatography (Agilent 8860) analysis shows the product purity to be 98.4%.

[0061] Spectral characterization of 4-hydroxymethyl vinyl sulfite:

[0062]

[0063] 1 H NMR (400MHz, CDCl3) δ: 4.75-4.69(m, 1H)ppm, 4.64-4.60(m, 1H)ppm, 4.49-4.46(m, 1H)ppm, 3.98-3.94(m, 1H)ppm, 3.78-3.74, 3.06(s, 1H)ppm.

[0064] Example 5

[0065] This embodiment provides a method for preparing vinyl sulfite compounds. 100g of 3,4-epoxy-1-butene, 150mL of dimethyl sulfoxide, and 60g of 4.5mmol / g polystyrene-supported dimethylaminopyridine (PS-DMAP) are added to a reaction vessel. SO2 is slowly and continuously introduced until the pressure inside the vessel reaches 0.5MPa. The reaction is carried out at 90°C for 5 hours, then cooled to 21°C. Nitrogen gas is slowly introduced through the exhaust valve to release excess SO2. PS-DMAP is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain 135g of 4-vinylvinyl sulfite, with a product yield of 86%. Gas chromatography (Agilent 8860) analysis shows the product purity to be 94%.

[0066] Spectral characterization of 4-vinylvinylsulfite:

[0067]

[0068] 1 The molar ratio of the major to minor isomers in ¹H NMR (400MHz, CDCl₃) was 1.0:0.7. The major isomers had the following δ values: 5.79-5.70 (m, 1H), 5.47-5.46 (m, 1H), 5.39-5.34 (m, 2H), 4.69-4.66 (m, 1H), and 3.97-3.93 (m, 1H); the minor isomers had the following δ values: 5.95-5.87 (m, 1H), 5.43-5.42 (m, 1H), 5.34-5.29 (m, 1H), 4.86-4.80 (m, 1H), 4.50-4.47 (m, 1H), and 4.32-4.28 (m, 1H). 13 C NMR (100MHz, CDCl3) Major isomers δ: 130.9, 121.3, 80.4, 71.2; Minor isomers δ: 132.2, 122.1, 84.3, 69.3.

[0069] Example 6

[0070] This embodiment provides a method for preparing vinyl sulfite compounds. 100g of trifluoromethyl propylene oxide, 150mL of dioxane, and 50g of 5mmol / g polystyrene-supported 1,8-diazabicyclo[5.4.0]undec-7-ene (PS-DBU) are added to a reaction vessel. SO2 is slowly and continuously introduced until the pressure inside the vessel reaches 0.5MPa. The reaction is carried out at 90°C for 10h, then cooled to 25°C. Nitrogen gas is slowly introduced through the exhaust valve to release excess SO2. PS-DBU is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain 135g of trifluoromethyl vinyl sulfite, with a yield of 86%. Gas chromatography (Agilent 8860) analysis shows the product purity to be 98.8%.

[0071] Spectral characterization of 4-trifluoromethyl vinyl sulfite:

[0072]

[0073] 1 H NMR (400MHz, CDCl3) δ: 5.10-5.03 (m, 1H)ppm, 4.87-4.82 (m, 1H)ppm, 4.69-4.66 (dd, J=9.6, 2.8Hz, 1H); 13 C NMR (100MHz, CDCl3) δ: 126.4-118.1(q, 1C)ppm, 76.5-75.5(q, 1C)ppm, 66.9-66.8(q, 1C)ppm; 19F NMR (376MHz, CDCl3) δ: -78.7 (s, CF3) ppm, isomer (-75.3, s, CF3) ppm.

[0074] Example 7

[0075] This embodiment provides a method for preparing a vinyl sulfite compound. 50g of butadiene diepoxide, 200mL of acetonitrile, and 30g of polystyrene-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene are added to a reaction vessel. SO2 is slowly and continuously introduced until the pressure inside the vessel reaches 0.2MPa. The reaction is carried out at 80°C for 3 hours, then cooled to 25°C. Nitrogen gas is slowly introduced through the exhaust valve to release excess SO2. PS-BEMP is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain 115g of 4,4'-bi(1,3,2-dioxothiacyclopentane)-2,2'-dioxide, with a yield of 93%. Gas chromatography (Agilent 8860) analysis showed the product purity to be 99.7%.

[0076] Spectral characterization of 4,4'-bi(1,3,2-dioxothiacyclopentane)-2,2'-dioxide:

[0077]

[0078] 1 H NMR (400MHz, CDCl3) δ: 4.86 (m, 2H), 4.76 (m, 2H), 4.58 (m, 2H) ppm.

[0079] This invention utilizes a specific structured supported organic base to catalyze the reaction of sulfur dioxide and epoxides to prepare cyclic vinyl sulfite compounds. The product is easy to purify, has a high yield, and is easily produced in a continuous and automated manner.

[0080] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a vinyl sulfite compound, characterized in that, The preparation method includes the following steps: under the action of a supported organic base catalyst, an epoxy compound and sulfur dioxide undergo an addition cyclization reaction to obtain a vinyl sulfite ester compound; The vinyl sulfite compounds have the following general structural formula: Among them, R 1 R 2 R 3 and R 4 Each is independently selected from hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, alkenyl, alkynyl, aryl, substituted aryl, hydroxyl, fluorinated alkyl, or vinyl sulfite.

2. The preparation method according to claim 1, characterized in that, The supported organic base catalyst comprises any one or a combination of at least two of the following: 1,5,7-triazabicyclo[4.4.0]dec-5-ene supported on polystyrene, dimethylaminopyridine supported on polystyrene, 1,8-diazabicyclo[5.4.0]undec-7-ene supported on polystyrene, or 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphide supported on polystyrene.

3. The preparation method according to claim 1 or 2, characterized in that, The epoxy compound includes any one or a combination of at least two of the following: ethylene oxide, propylene oxide, 1,2-dimethylethylene oxide, 1,1,1-trifluoro-2,3-propylene oxide, vinyl ethylene oxide, or dibutyronitrile.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The molar ratio of the epoxy compound, sulfur dioxide, and supported organic base catalyst is 1:(1-5):(0.05-0.5).

5. The preparation method according to any one of claims 1 to 4, characterized in that, The amount of sulfur dioxide added is controlled so that the pressure of the reaction system is 0.1–0.4 MPa; Preferably, the reaction temperature is 20–120°C, more preferably 40–80°C; Preferably, the reaction time is 2 to 24 hours; Preferably, the reaction is carried out in a solvent; Preferably, the solvent includes any one or a combination of at least two of the following: acetonitrile, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, dichloromethane, dichloroethane, tetrachloroethane, dimethyl carbonate, diethyl carbonate, or methyl ethyl carbonate.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The reaction process also includes post-processing and product purification.

7. The preparation method according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: epoxide and sulfur dioxide are reacted at 25-120°C and 0.1-0.4 MPa for 2-24 h under the action of a supported organic base catalyst, then cooled to 20-25°C, the supported organic base catalyst is recovered by filtration, and the filtrate is subjected to vacuum distillation to obtain cyclic vinyl sulfite compounds, wherein the molar ratio of epoxide, sulfur dioxide and supported organic base catalyst is 1:(1-5):(0.05-0.5).

8. A vinyl sulfite compound, characterized in that, The vinyl sulfite compound is prepared by the preparation method according to any one of claims 1 to 7.

9. The vinyl sulfite compound according to claim 8, characterized in that, The vinyl sulfite compounds have any one or a combination of at least two of the structures shown in formulas II-1 to II-10:

10. An electrolyte additive, characterized in that, The electrolyte additive includes the vinyl sulfite compounds as described in claim 8 or 9.

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