A method for preparing ethylene carbonate and ethylene sulfate

Abstract

This invention provides a method for preparing ethylene carbonate and ethylene sulfate, comprising the following steps: 1) using ethylene carbonate as a raw material, reacting it with an oxidant to obtain epoxy ethylene carbonate as shown in Formula I; 2) reacting the epoxy ethylene carbonate of Formula I obtained in step 1) with aminosulfonic acid in an acidic solvent to obtain ethylene carbonate and ethylene sulfate as shown in Formula II. This method avoids the problem of poor reaction selectivity caused by using butanetetrol as a raw material in the prior art; the method described in this invention does not generate the intermediate butanetetrol carbonate ester, thus avoiding the problem of further reaction of this intermediate to generate the byproduct 2,4,7-trioxa-3-oxy-bicyclo[3.3.0]octane; in addition, this invention uses mild and non-irritating aminosulfonic acid in the synthesis of the final product sulfate, which is also clean, green, and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of electrolyte additives for new energy batteries, and specifically relates to a method for preparing ethylene carbonate and ethylene sulfate. Background Technology

[0002] With the continuous growth of global demand for clean energy, the new energy industry is experiencing rapid development. As a core pillar of the new energy industry, the market size of new energy batteries will continue to expand. Taking lithium batteries as an example, according to statistics from GGII (Gaogong Industry Research Institute), China's lithium battery shipments reached 776 GWh in the first half of 2025, a year-on-year increase of 68%. Among them, power batteries and energy storage batteries accounted for 477 GWh and 265 GWh respectively, representing year-on-year increases of 49% and 128%.

[0003] New energy batteries are mainly composed of positive electrode materials, negative electrode materials, electrolytes, and separators. The electrolyte itself consists of solvents, solutes, and additives. Among these, electrolyte additives have a significant impact on battery performance. Excellent electrolyte additives can significantly improve the battery's electrochemical performance, such as enhancing performance, safety, and cycle life, meeting the needs of different application scenarios, and are a key component of energy storage devices such as lithium-ion batteries. For example, ethylene carbonate (EC) and ethylene sulfate (DTD) additives occupy an important position in battery electrolyte additives. Ethylene carbonate (EC) is an important component of lithium battery electrolytes, possessing a high dielectric constant, which is beneficial for the dissociation of lithium salts. It has a high film-forming potential on the negative electrode, preferentially precipitating and participating in the formation of the SEI film, stabilizing the negative electrode and providing suitable impedance, playing a crucial role in improving the overall performance of the battery. Ethylene sulfate (DTD) additives can further effectively improve the stability and safety of the battery.

[0004] Studies have shown that the novel additive of ethylene carbonate and ethylene sulfate combines the excellent film-forming properties of ethylene carbonate with the stability of ethylene sulfate, thereby improving battery cycle performance and enhancing battery safety under high voltage. This additive will expand the application range of batteries, suppress the decline in initial battery capacity, increase initial discharge capacity, reduce battery expansion after high-temperature storage, reduce capacity decay and internal resistance, improve the battery's high-temperature cycle, high-temperature storage and low-temperature discharge performance, enhance the stability of graphite anodes, and improve battery cycle performance. Therefore, the novel additive of ethylene carbonate and ethylene sulfate has high application value in the field of new energy batteries, can meet the market demand for high-performance batteries, and provide a new direction for the development of the battery industry.

[0005] However, compared to its broad market prospects, there are very few reports on the synthesis and preparation methods of this additive compound, and the existing preparation methods also have obvious shortcomings:

[0006] (1) In patent CN111763200A, erythritol is used to undergo transesterification with carbonate under alkaline catalyst to obtain erythritol carbonate, which is then reacted with sulfonyl chloride to obtain ethylene carbonate disulfate. However, in actual preparation, this method is prone to side reactions as reported in the literature Green Chem., 2012, 14, 1749, resulting in low reaction yield and making it unsuitable for the synthesis of the target molecule ethylene carbonate disulfate.

[0007]

[0008] (2) Patent CN118184644A reports the preparation of butylene carbonate ester by reacting butylene tert-tetraethanolamine (erythritol) with carbonyl diimidazole, followed by the reaction with thionyl chloride or thionyl diimidazole to prepare a sulfite intermediate, and finally the preparation of ethylene carbonate disulfate ester by oxidation. This route can reduce the occurrence of the above-mentioned side reactions to a certain extent, but there are other problems. For example, the reaction of butylene tert-tetraethanolamine (erythritol) with carbonyl diimidazole also has the problem of poor selectivity. In addition, the thionyl chloride used in the reaction or the preparation of thionyl diimidazole with thionyl chloride has the problems of volatilization and equipment corrosion.

[0009]

[0010] Existing methods include using erythritol as a raw material and reacting it with carbonyl compounds such as dimethyl carbonate or carbonyl diimidazole to prepare the intermediate erythritol carbonate via transesterification. This method has significant problems, such as poor selectivity. Erythritol contains four hydroxyl groups, and all four hydroxyl groups will participate in the reaction under elevated temperature and alkaline catalysis, resulting in poor reaction selectivity, numerous intermediates, and low reaction yield. The intermediate erythritol carbonate will further convert into the corresponding byproduct 2,4,7-trioxa-3-oxy-bicyclo[3.3.0]octane under elevated temperature, thus failing to obtain the target product or obtaining the product in a very low yield. Furthermore, the synthesis of sulfate or sulfite esters uses volatile and irritating reagents such as sulfonyl chloride, thionyl chloride, or thionyl diimidazole prepared from thionyl chloride, which can cause corrosion and pollution problems to the health of operators, reaction equipment, and production environment.

[0011] Therefore, developing a highly efficient synthetic method for preparing ethylene carbonate and ethylene sulfate with mild reaction conditions, environmental friendliness, and ease of production has significant application value. Summary of the Invention

[0012] In view of the shortcomings of the prior art described above, this invention proposes a new method for preparing ethylene carbonate and ethylene sulfate, taking into account factors such as reaction selectivity, reduction of side reactions, health, greenness, and environmental friendliness.

[0013] The technical solution of this invention is:

[0014] This invention provides a method for preparing ethylene carbonate and ethylene sulfate, comprising the following steps:

[0015] 1) Using ethylene carbonate as a raw material, an oxidizing agent is reacted to obtain epoxy ethylene carbonate as shown in Formula I.

[0016] 2) The epoxy ethylene carbonate ester of formula I obtained in step 1) is reacted with aminosulfonic acid in an acidic solvent and heated to obtain ethylene carbonate bisulfate ester of formula II.

[0017]

[0018] By adopting the aforementioned technical solution, the beneficial effects of the present invention are:

[0019] As described above, this invention develops a novel method for preparing ethylene carbonate and ethylene sulfate (CAS: 2507955-35-1) using ethylene ethylene carbonate (VEC) as a raw material. This method avoids the poor reaction selectivity problem caused by the use of erythritol as a raw material in existing technologies; the method described in this invention does not generate the intermediate erythritol carbonate, thus avoiding the problem of this intermediate further reacting to generate the byproduct 2,4,7-trioxa-3-oxy-bicyclo[3.3.0]octane; in addition, this invention uses mild and non-irritating aminosulfonic acid in the synthesis of the final product sulfate ester, avoiding the use of volatile, irritating, and corrosive reagents such as sulfonyl chloride and thionyl chloride, and is also clean, green, and environmentally friendly. Attached Figure Description

[0020] Figure 1 The 1H NMR spectrum of ethylene carbonate and ethylene sulfate in Example 2;

[0021] Figure 2 The carbon NMR spectrum of ethylene carbonate and ethylene sulfate in Example 2;

[0022] Figure 3 The single-crystal diffraction structure of ethylene carbonate and ethylene sulfate from Example 2 is shown. Detailed Implementation

[0023] The following describes in detail the embodiments of the preparation method of ethylene carbonate and ethylene sulfate 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] Preparation method of ethylene carbonate and ethylene sulfate

[0026] This invention provides a method for preparing ethylene carbonate and ethylene sulfate, comprising the following steps:

[0027] 1) Using ethylene carbonate as a raw material, an oxidizing agent is reacted to obtain epoxy ethylene carbonate as shown in Formula I.

[0028] 2) The epoxy ethylene carbonate ester of formula I obtained in step 1) is reacted with aminosulfonic acid in an acidic solvent and heated to obtain ethylene carbonate bisulfate ester of formula II.

[0029] The preparation method can be represented by the following reaction formula:

[0030]

[0031] In the preparation method provided by this invention, step 1) uses ethylene carbonate as a raw material and reacts it with an oxidant to obtain epoxy ethylene carbonate as shown in Formula I. Specifically:

[0032] In step 1) of this invention, the ethylene ethylene carbonate raw material can be purchased commercially or prepared by existing known methods, such as detailed preparation methods in patents CN105566279 and CN116496243.

[0033] In step 1) of the present invention, an organic solvent is also included, wherein the organic solvent is one or more of ethyl acetate, dimethyl carbonate, diethyl carbonate, tetrahydrofuran, dioxane, dichloromethane, dichloroethane, chloroform, toluene or xylene; in step 1), the volume of the organic solvent is 2 to 10 times that of ethylene ethylene carbonate and any value between them or any two values, and may be selected as 2 to 5 times, 5 to 8 times, or 8 to 10 times.

[0034] In step 1) of this invention, the oxidant is one or more of peracetic acid, perbenzoic acid, m-chloroperbenzoic acid, hydrogen peroxide, or pertrifluoroacetic acid.

[0035] In step 1) of the present invention, the molar ratio of the oxidant to ethylene carbonate is 1 to 3:1 and any value between them or any range between two values, and can be selected as 1 to 2:1 or 2 to 3:1.

[0036] In step 1) of the present invention, the oxidation reaction temperature is 0 to 100 ℃ and any value between them or any two values; preferably, the oxidation reaction temperature is 10 to 60 ℃, and more preferably, the oxidation reaction temperature is 10 to 30 ℃.

[0037] In step 1) of the present invention, the oxidation reaction time is 1h to 16h and any value between them or any two values, and can be selected as 1h to 8h, 8h to 16h, 1h to 4h, 4h to 8h, 8h to 12h, or 12h to 16h.

[0038] In step 1) of this invention, the structure of the epoxy ethylene carbonate represented by Formula I is as follows: Formula I represents ethylene oxide carbonate, which includes all its monomer configurations or mixtures thereof, such as monomers IA, IB, IC, ID, or mixtures of at least two thereof.

[0039] .

[0040] Step 1) of the present invention further includes the following post-processing: the post-processing includes quenching the residual oxidant in step 1) with a saturated sodium bisulfite solution, washing the organic phase with saturated sodium bicarbonate water, drying with anhydrous sodium sulfate, and concentrating it to obtain the epoxy ethylene carbonate ester shown in Formula I.

[0041] In the preparation method provided by this invention, step 2) involves reacting the epoxy ethylene carbonate of formula I obtained in step 1) with aminosulfonic acid in an acidic solvent at elevated temperature to obtain ethylene carbonate bisulfate of formula II. Specifically:

[0042] In step 2) of this invention, the acidic solvent is a combination solvent of organic acid and auxiliary organic solvent.

[0043] In step 2) of this invention, the auxiliary organic solvent is selected from one or more of dichloromethane, 1,2-dichloroethane, tetrahydrofuran, methyltetrahydrofuran, ethyl acetate, dimethyl carbonate, diethyl carbonate, dioxane, toluene, or xylene.

[0044] In step 2) of this invention, the organic acid is selected from one or more of acetic acid, formic acid, or trifluoroacetic acid.

[0045] In step 2) of the present invention, the acidic solvent is 3 to 5 times the weight of the epoxy ethylene carbonate shown in Formula I, or any value between them or any range between any two values, and can be selected as 3 to 4 times or 4 to 5 times.

[0046] In step 2) of this invention, the volume ratio of the organic acid to the auxiliary organic solvent is 1 to 10:1, or any value between them or any range between any two values, and can be selected as 1 to 5:1, 5 to 10:1, 1 to 3:1, 3 to 5:1, 5 to 8:1, or 8 to 10:1. For example, the volume ratio of acetic acid to the auxiliary organic solvent is 1 to 10:1, the volume ratio of formic acid to the auxiliary organic solvent is 1 to 10:1, and the volume ratio of trifluoroacetic acid to the auxiliary organic solvent is 1 to 10:1, etc.

[0047] In step 2) of the present invention, the molar ratio of aminosulfonic acid to ethylene carbonate is 1.0 to 3.0:1.0 and any value between them or any range between any two values, and can be selected as 1.0 to 2.0:1.0 or 2.0 to 3.0:1.0.

[0048] In step 2) of the present invention, the heating reaction temperature is 40 ℃~110 ℃ and any value between them or any two values, and can be selected as 40 ℃~70 ℃, 70 ℃~110 ℃, 40 ℃~60 ℃, 60 ℃~80 ℃, 80 ℃~110 ℃.

[0049] In step 2) of the present invention, the heating reaction time is 1h to 24h and any value between them or any two values, and can be selected as 1h to 8h, 8h to 16h, or 16h to 24h.

[0050] In step 2) of this invention, a crude product is obtained by reaction. The crude product is then purified to obtain ethylene carbonate and ethylene sulfate as shown in Formula II. The purification process includes dilution, filtration, crystallization, and drying.

[0051] In the purification process, the dilution is achieved by adding an aqueous solvent. The volume of the aqueous solvent used is 1 to 3 times the amount of acidic solvent in step 2), or any value between them or any two values, and can be selected as 1 to 2 times or 2 to 3 times.

[0052] In the purification process, the solvent used for crystallization is selected from one or more of methanol, ethanol, and acetonitrile.

[0053] In the purification process, the drying temperature is 40–80 °C or any value between them or any two values, and can be selected as 40–60 °C or 60–80 °C.

[0054] In the purification process, the drying time is 2h to 24h and any value between them or any two values, and can be selected as 2h to 12h, 12h to 24h, 2h to 6h, 6h to 12h, 12h to 18h, or 18h to 24h.

[0055] In step 2) of this invention, the structure of ethylene carbonate and ethylene sulfate represented by formula II is as follows: (CAS: 2507955-35-1). Ethylene carbonate disulfate of Formula II includes all its configuration monomers or mixtures thereof, such as monomers II-A, II-B, II-C, II-D, or at least two mixtures thereof;

[0056] .

[0057] The beneficial effects of the present invention will be further illustrated below with reference to the embodiments.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Example 1: Preparation of 4-(ethylene oxide-2-yl)-1,3-dioxolane-2-one (Formula I)

[0062] Add ethylene carbonate (10 g, 87.6 mmol) to a 250 mL reaction flask, add dichloromethane (30 mL) and stir to dissolve. Cool the system to 10 °C in an ice bath, and slowly add a dichloromethane (40 mL) solution containing 80% m-chloroperoxybenzoic acid (18.9 g, 87.6 mmol). Then react at room temperature for 4 h. After the reaction is complete, quench the residual peroxy acid with saturated sodium bisulfite solution, wash the organic phase twice with saturated sodium bicarbonate aqueous solution, dry and concentrate to obtain 4-(ethylene oxide-2-yl)-1,3-dioxolane-2-one (10.2 g, 88%) as a colorless oil.

[0063] Spectral characterization of 4-(ethylene oxide-2-yl)-1,3-dioxolane-2-one (Formula I):

[0064] 1H NMR (400 MHz, Chloroform-d) δ: 4.80 – 4.70 (m, 2H), 4.58 (t, J =8.5 Hz, 1H), 4.47 (t, J = 8.5 Hz, 1H), 4.39 (dd, J = 8.6, 6.1 Hz, 1H), 4.20(dd, J = 8.6, 6.3 Hz, 1H), 3.28 (td, J = 4.0, 2.6 Hz, 1H), 3.20 (td, J = 3.9,2.6 Hz, 1H), 2.92 (t, J = 4.2 Hz, 1H), 2.86 (t, J = 4.4 Hz, 1H), 2.83 (dd, J= 4.8, 2.6 Hz, 1H), 2.63 (dd, J = 4.3, 2.6 Hz, 1H).

[0065] Example 2: Preparation of ethylene carbonate and ethylene sulfate (Formula II)

[0066] Add 10 g (76.8 mmol) of 4-(ethylene oxide-2-yl)-1,3-dioxolane-2-one to a 250 mL reaction flask, along with 10 mL of 1,4-dioxane solvent and 20 mL of acetic acid at room temperature. After stirring at room temperature for 30 minutes, slowly add 9.0 g (92.2 mmol) of aminosulfonic acid. Then, raise the temperature to 60 °C and react for 3 h. After the reaction is complete, cool to room temperature and slowly add 60 mL of water dropwise while stirring. An insoluble substance precipitates out of the system. Filter and collect the pale yellow solid. Crystallize the solid with methanol to obtain a white solid. Filter and collect the solid, then dry it under vacuum at 50 °C for 4 h to obtain ethylene carbonate diethylene sulfate (13 g, 80%) as a white solid.

[0067] Spectral characterization of ethylene carbonate and ethylene sulfate (Formula II):

[0068] 1 H NMR (400 MHz, Acetonitrile-d 3 ) δ: 5.34 (ddd, J = 6.8, 6.1, 4.1 Hz, 1H), 5.07 (ddd, J = 8.6, 5.7, 4.2 Hz, 1H), 4.93 (dd, J = 9.9, 6.8 Hz, 1H), 4.73 – 4.60 (m, 2H), 4.42 (dd, J = 9.3, 5.7 Hz, 1H).

[0069] Example 3: Preparation of ethylene carbonate and ethylene sulfate (Formula II)

[0070] The starting material 4-(ethylene oxide-2-yl)-1,3-dioxolane-2-one (10 g, 76.8 mmol) was added to the reaction flask, followed by 1,4-dioxane solvent (10 mL) and formic acid (20 mL) at room temperature. After stirring at room temperature for 30 minutes, aminosulfonic acid (9.0 g, 92.2 mmol) was slowly added. The temperature was then raised to 60 °C and reacted for 3 h. After the reaction was completed, the temperature was lowered to room temperature, and water (60 mL) was slowly added dropwise with stirring. An insoluble substance precipitated from the system. The pale yellow solid was collected by filtration. The solid was crystallized from methanol to obtain a pure white solid. The solid was collected by filtration and dried under vacuum at 50 °C for 4 h to obtain the target ethylene carbonate disulfate pure product (12.2 g, 76%) as a white solid.

[0071] Example 4: Preparation of ethylene carbonate and ethylene sulfate (Formula II)

[0072] 4-(ethylene oxide-2-yl)-1,3-dioxolane-2-one (10 g, 76.8 mmol) was added to the reaction flask, followed by 1,4-dioxane solvent (10 mL) and trifluoroacetic acid (10 mL) at room temperature. After stirring at room temperature for 30 minutes, aminosulfonic acid (9.0 g, 92.2 mmol) was slowly added. The temperature was then raised to 60 °C and reacted for 3 hours. After the reaction was completed, the temperature was lowered to room temperature, and water (60 mL) was slowly added dropwise with stirring. An insoluble substance precipitated from the system. The pale yellow solid was collected by filtration and purified by methanol crystallization to obtain a white solid. The solid was collected by filtration and dried under vacuum at 50 °C for 4 hours to obtain ethylene carbonate and ethylene sulfate (13.5 g, 84%).

[0073] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0074] 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 method for preparing ethylene carbonate and ethylene sulfate, characterized in that, Includes the following steps: 1) Using ethylene carbonate as a raw material, an oxidizing agent is reacted to obtain epoxy ethylene carbonate as shown in Formula I. 2) The epoxy ethylene carbonate ester of formula I obtained in step 1) is reacted with aminosulfonic acid in an acidic solvent and heated to obtain ethylene carbonate bisulfate ester of formula II. In step 1), the oxidation reaction time is 1 h to 16 h; In step 2), the acidic solvent is a combination solvent of an organic acid and an auxiliary organic solvent, the heating reaction temperature is 40 ℃~60 ℃, and the heating reaction time is 1h~8h; the organic acid is selected from one or more of acetic acid, formic acid or trifluoroacetic acid, and the auxiliary organic solvent is 1,4-dioxane; 。 2. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 1, characterized in that, Step 1) also includes one or more of the following conditions: A1) Step 1) further includes an organic solvent, wherein the organic solvent is one or more of ethyl acetate, dimethyl carbonate, diethyl carbonate, tetrahydrofuran, dioxane, dichloromethane, dichloroethane, chloroform, toluene, or xylene; A2) In step 1), the oxidant is selected from one or more of peracetic acid, perbenzoic acid, m-chloroperbenzoic acid, hydrogen peroxide or pertrifluoroacetic acid; A3) In step 1), the molar ratio of the oxidant to ethylene carbonate is 1 to 3:1; In step 1) of A4), the oxidation reaction temperature is 0 to 100 °C.

3. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 2, characterized in that, It also includes one or more of the following conditions: A11) In feature A1), the volume of the organic solvent is 2 to 10 times that of ethylene carbonate; In step 1) of A41, the temperature of the oxidation reaction is 10–60 °C.

4. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 3, characterized in that, The oxidation reaction temperature is 10–30 °C.

5. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 1, characterized in that, The epoxy ethylene carbonate shown in Formula I includes monomers IA, IB, IC, ID, or a mixture of at least two of them; 。 6. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 1, characterized in that, Step 1) also includes the following post-processing, which includes quenching the residual oxidant in step 1) with a saturated sodium bisulfite solution, washing the organic phase with saturated sodium bicarbonate water, drying with anhydrous sodium sulfate, and concentrating it to obtain the epoxy ethylene carbonate ester shown in Formula I.

7. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 1, characterized in that, In step 2), the molar ratio of aminosulfonic acid to ethylene carbonate is 1.0 to 3.0:1.

0.

8. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 1, characterized in that, Step 2) also includes one or more of the following conditions: In step 2) of B11), the acidic solvent is 3 to 5 times the weight of the epoxy ethylene carbonate shown in Formula I; In step 2) of B12, the volume ratio of the organic acid to the auxiliary organic solvent is 1 to 10:

1.

9. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 1, characterized in that, Step 2) The reaction yields a crude product, which is then purified to obtain ethylene carbonate and ethylene sulfate as shown in Formula II. The purification process includes dilution, filtration, crystallization, and drying.

10. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 9, characterized in that, It also includes one or more of the following conditions: In the purification process described in C1), the dilution is performed by adding an aqueous solvent, and the volume of the aqueous solvent used is 1 to 3 times the amount of acidic solvent used in step 2). In the purification process described in C2), the solvent used for crystallization is selected from one or more of methanol, ethanol, and acetonitrile. In the purification process described in C3), the drying temperature is 40–80 °C; In the purification process described in C4), the drying time is 2h to 24h.

11. The method for preparing ethylene carbonate and ethylene sulfate as described in claim 1, characterized in that, In step 2), the ethylene carbonate disulfate of formula II includes monomers II-A, II-B, II-C, II-D, or at least two mixtures thereof; 。

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