Preparation method of electrolyte additive ethylene sulfate and derivative thereof
The use of isopropyl hydrogen peroxide to oxidize sulfoxide ester derivatives into sulfuric ester derivatives in a homogeneous reaction addresses the cost and waste issues of existing methods, achieving high-purity and high-yield sulfuric ester production.
Patent Information
- Application Number
- CN202510455827.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2025-07-15
AI Technical Summary
The production cost of existing vinyl sulfate and its derivatives is high, and the amount of wastewater is large. The traditional oxidation method uses precious metal catalysts and heterogeneous reactions to cause cumbersome processes.
Isopropyl hydrogen peroxide is used as an oxidant and reacts with vinyl sulfite and its derivatives in an aprotic solvent to form vinyl sulfite and its derivatives. High-purity products are prepared by distillation and concentration crystallization, avoiding the use of expensive catalysts and water extraction.
The preparation of vinyl sulfate and its derivatives with high purity and high yield is achieved, which reduces production costs, reduces waste liquid emissions, simplifies the reaction process, and is suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] This application relates to the technical field of battery electrolyte additives, and particularly to a preparation method of ethylene sulfite and its derivatives as electrolyte additives. Background Art
[0002] Ethylene sulfite and its derivatives can be used as additives for lithium-ion battery electrolytes, mainly including ethylene sulfite, 4-methyl ethylene sulfite, 4-ethyl ethylene sulfite, 4-propyl ethylene sulfite, propylene sulfite, 1,4-butanediol sulfate, etc. Currently in industry, ethylene sulfite derivatives are mainly prepared as intermediates by reacting diol compounds with thionyl chloride, and then oxidized to obtain ethylene sulfite and its derivatives. There are two commonly used oxidation methods in industry: 1. Using sodium hypochlorite as an oxidant, and ruthenium(III) chloride and other catalysts to catalyze the oxidation of ethylene sulfite and its derivatives into ethylene sulfite and its derivatives. This method will produce a large amount of saline wastewater, and the precious metal catalyst ruthenium(III) chloride used is difficult to recycle. Ruthenium is an extremely expensive rare precious metal, and its high price also makes the synthesis process cost of ethylene sulfite very high; 2. Using hydrogen peroxide as an oxidant and titanium silicalite TS-1 as a catalyst to oxidize ethylene sulfite and its derivatives to produce ethylene sulfite and its derivatives. In this reaction system, the three phases of hydrogen peroxide, catalyst, and ethylene sulfite and its derivatives are all immiscible, belonging to a heterogeneous reaction. The hydrogen peroxide content is generally 27%-30%. After the reaction, a large amount of wastewater will be generated, and the catalyst needs to be recovered by filtration. The process is cumbersome, and at the same time, the catalyst is expensive, resulting in high costs. Summary of the Invention
[0003] In order to reduce the production cost of ethylene sulfite and its derivatives and reduce the amount of wastewater, this application provides a preparation method of ethylene sulfite and its derivatives as electrolyte additives.
[0004] In the first aspect, this application provides a preparation method of ethylene sulfite and its derivatives as electrolyte additives, adopting the following technical solution: A preparation method of ethylene sulfite and its derivatives as electrolyte additives, which uses ethylene sulfite and its derivatives and cumyl hydroperoxide as reactants to generate ethylene sulfite and its derivatives and isopropanol; the reaction general formula is as follows: R1-R4 are hydrogen atoms or C 1-3 alkyl groups.
[0005] By adopting the above technical solution, compared with the prior art, the oxidation method of the present application oxidizes ethylene sulfite and its derivatives with cumyl hydroperoxide. The reaction is controllable and stable, without the need to additionally add expensive catalysts. Moreover, there is no water in the generated product, and there is no need to extract with water after the reaction. The generated isopropanol can be very well dissolved in the solvent. Through distillation, concentration and crystallization, a product with high purity and high yield can be prepared; it can save production costs, and the waste liquid discharge is greatly reduced. The reaction process is simple and easy to operate, suitable for mass production.
[0006] Preferably, it includes the following preparation steps: Dissolve the ethylene sulfite and its derivatives in an aprotic solvent, then dropwise add cumyl hydroperoxide, react at 20 - 50 °C, and after the reaction is completed, concentrate and crystallize to obtain the product, namely the ethylene sulfate and its derivatives.
[0007] By adopting the above technical solution, the oxidation reaction of cumyl hydroperoxide is relatively fast and can proceed efficiently and controllably without too high a temperature. Moreover, cumyl hydroperoxide is prone to decomposition at higher temperatures, which is not conducive to the reaction and will instead cause a decrease in the reaction yield; at this temperature, relatively high yields can be obtained, and the purity of the prepared product is also relatively high, which can meet the usage requirements.
[0008] Preferably, the molar ratio of the cumyl hydroperoxide to the ethylene sulfite and its derivatives is (1.02 - 1.1):1.
[0009] By adopting the above technical solution, when the molar amount of cumyl peroxide added is 1.02 - 1.1 times that of ethylene sulfite and its derivatives, the reaction yield can reach over 94.5%. When its addition amount is increased to more than 1.05 times that of ethylene sulfite and its derivatives, the yield and purity of the target product gradually level off. When its addition amount is higher than 1.1 times the molar amount of ethylene sulfite and its derivatives, it will cause waste of reaction raw materials.
[0010] Preferably, the mass ratio of the aprotic solvent to the ethylene sulfite and its derivatives is (8 - 15):1.
[0011] By adopting the above technical solution, under this ratio, the reaction can proceed stably and efficiently.
[0012] Preferably, the dropping time of the cumyl hydroperoxide is 1 - 3 h, and the reaction time is 0.5 - 1.5 h.
[0013] By adopting the above technical solution, ensuring sufficient dropping time can enable the reaction to proceed smoothly and will not cause decomposition of cumyl hydroperoxide due to local overheating, resulting in incomplete reaction.
[0014] Preferably, the reaction temperature is 20 - 30°C.
[0015] By adopting the above technical solution, when the cumyl hydroperoxide dropped in undergoes local reaction, the heat released raises the temperature of the local solution to a relatively high level, thereby decomposing the unreacted cumyl hydroperoxide locally. Controlling the reaction to proceed at a lower temperature can make the reaction stable and efficient. Moreover, at this temperature, the reaction time can also be completed within 1 h, and the comprehensive cost is relatively low.
[0016] Preferably, the concentration and crystallization are carried out by distillation.
[0017] By adopting the above technical solution, distillation can accelerate the rate of concentration and crystallization and improve production efficiency.
[0018] Preferably, the aprotic solvent is one or more of dichloromethane, 1,2 - dichloroethane, chloroform, carbon tetrachloride, dimethyl carbonate, and diethyl carbonate.
[0019] By adopting the above technical solution, the reaction of the present application has a high tolerance for the reaction solvent, and various aprotic solvents can well dissolve the reactants to enable them to react fully.
[0020] Preferably, the product undergoes secondary concentration and crystallization, and the operation is as follows: Dropwise add the aprotic solvent to the obtained product while stirring. Stop adding when it is just completely dissolved, and then carry out evaporation concentration and crystallization to obtain ethylene sulfate and its derivatives.
[0021] By adopting the above technical solution, through another evaporation crystallization, the purity of the product can be further improved.
[0022] Preferably, the ethylene sulfate and its derivatives are any one of ethylene sulfate, 4 - methyl ethylene sulfate, 4 - ethyl ethylene sulfate, 4 - propyl ethylene sulfate, allyl sulfate, and 1,4 - butanediol sulfate.
[0023] By adopting the above technical solution, the designed reaction route and preparation method of the present application are applicable to the preparation of various ethylene sulfates and their derivatives.
[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. Compared with the prior art, in the oxidation method of the present application, ethylenesulfite and its derivatives are oxidized by cumene hydroperoxide. The reaction is controllable and stable, without the need to additionally add expensive catalysts. Moreover, there is no water in the generated product, and there is no need to extract with water after the reaction. The generated isopropanol can be very well dissolved in the solvent. By distillation, concentration and crystallization, a product with high purity and high yield can be obtained; it can save production costs, greatly reduce the waste liquid discharge, and the reaction process is simple and easy to operate, suitable for mass production.
[0025] 2. In the preparation method of ethylenesulfate and its derivatives designed in the present application, the purity of the obtained ethylenesulfate and its derivatives is 99.90% or above, and the highest can reach 99.99%; the yields are all between 93.5 - 94.9%; and through detection, in the products of the present application, the water content is ≤20 ppm; it shows that the preparation method of the present application can obtain target products with high purity and high yield; and the preparation method of the present application is simple, a homogeneous reaction, without the need to use expensive catalysts. During the whole reaction process, no water participates in the reaction and no water is generated; it greatly reduces the production cost and reduces the waste water volume. Detailed implementation manners
[0026] The following further elaborates on the present application in conjunction with specific content.
[0027] Raw materials The raw materials of the present application are all purchased commercially, and the purity is analytical pure. Examples
[0028] Example 1 A preparation method of an electrolyte additive, ethylenesulfate and its derivatives, the reaction general formula of which is shown in Formula 1, and it includes the following preparation steps: S1. Weigh 3000 g of aprotic solvent and add it to a 5000 mL four-neck reaction flask. While stirring, add 3 mol (324 g) of ethylenesulfite to make it completely dissolve; among them, the aprotic solvent is dichloromethane; S2. While stirring, uniformly add cumene hydroperoxide with a molar amount 1.05 times that of ethylenesulfite (239 g). The reaction temperature is controlled at 20 - 30 °C, and the dropping time is 2 hours. After the dropping is completed, keep the temperature at 20 - 30 °C and continue to react for 1 hour; S3. Distill the reaction solution after the reaction ends: under normal pressure conditions, the temperature is controlled at 40 - 50 °C. After concentration and crystallization, 352.3 g of ethylenesulfate with a purity of 99.93% is obtained, and the yield is 94.7%.
[0029] Formula 1 (R1 - R4 are hydrogen atoms or C 1-3(alkyl) Example 2 A preparation method of ethylene sulfate and its derivatives as an electrolyte additive, which is different from Example 1 in that the obtained ethylene sulfate is subjected to secondary concentration crystallization. Dichloromethane is added dropwise to the obtained ethylene sulfate while stirring until it is just completely dissolved, and then evaporation concentration crystallization is carried out again to obtain ethylene sulfate. The remaining steps are the same as those in Example 1.
[0030] Example 3 A preparation method of ethylene sulfate and its derivatives as an electrolyte additive, which is different from Example 1 in that the molar amount of isopropyl hydroperoxide added dropwise is 1.02 times that of vinyl sulfite, and the remaining steps are the same as those in Example 1.
[0031] Example 4 A preparation method of ethylene sulfate and its derivatives as an electrolyte additive, which is different from Example 1 in that the molar amount of isopropyl hydroperoxide added dropwise is 1.1 times that of vinyl sulfite, and the remaining steps are the same as those in Example 1.
[0032] Example 5 A preparation method of ethylene sulfate and its derivatives as an electrolyte additive, which is different from Example 1 in that the aprotic solvent is chloroform of equal mass, and the remaining steps are the same as those in Example 1.
[0033] Example 6 A preparation method of ethylene sulfate and its derivatives as an electrolyte additive, the reaction general formula of which is shown in Formula 1, and it includes the following preparation steps: S1. Weigh 3000 g of aprotic solvent and add it to a 5000 mL four-neck reaction flask. While stirring, add isopropyl hydroperoxide with a molar amount 1.05 times that of vinyl sulfite (239 g) to make it completely dissolve; among them, the aprotic solvent is dichloromethane; S2. While stirring, uniformly add 3 mol (324 g) of vinyl sulfite dropwise, control the reaction temperature at 20 - 30 °C, the dropping time is 2 hours, and after the dropping is completed, keep the temperature at 20 - 30 °C and continue to react for 1 hour; S3. Distill the reaction solution after the reaction is completed: under normal pressure conditions, control the temperature at 40 - 50 °C, and ethylene sulfate is obtained after concentration crystallization.
[0034] Example 7 A preparation method of ethylene sulfate and its derivatives as an electrolyte additive, the reaction general formula of which is shown in Formula 1, and it includes the following preparation steps: S1. Weigh 4000 g of an aprotic solvent and add it to a 5000 mL four-neck reaction flask. While stirring, add 366 g of vinyl methyl sulfite and stir until completely dissolved. Here, the aprotic solvent is 1,2-dichloroethane; S2. While stirring, uniformly add isopropyl hydroperoxide in an amount 1.05 times the molar amount of vinyl sulfite. Control the reaction temperature at 20 - 30 °C. The addition takes 2 hours. After the addition is completed, keep the temperature at 20 - 30 °C and continue to stir and react for 1 hour; S3. Distill the reaction solution after the reaction ends: Under atmospheric pressure, control the temperature at 40 - 50 °C. After concentration and crystallization, 392.4 g of vinyl methyl sulfite is obtained, with a yield of 94.6% and a purity of 99.94%.
[0035] Comparative Example Comparative Example 1 A preparation method of ethylene sulfite and its derivatives as an electrolyte additive is different from that of Example 1 in that the reaction temperature in S2 is controlled at 60 - 70 °C, and the other steps are the same as those in Example 1.
[0036] Performance Detection Test Detection Method / Test Method Prepare ethylene sulfite and its derivatives according to the preparation methods of Examples 1 - 7 and Comparative Example 1 respectively, and detect the purity and calculate the yield of their products. The results are shown in Table 1.
[0037] Table 1 Detection Results of Examples 1 - 7 and Comparative Example 1 It can be seen from Examples 1 - 7, Comparative Example 1, and the detection data in Table 1 that for the preparation method of ethylene sulfite and its derivatives designed in this application, the purity of the prepared ethylene sulfite and its derivatives is 99.90% or above, and the highest can reach 99.99%; the yields are all between 93.5 - 94.9%; and through detection, the water content in the products of this application is all ≤ 20 ppm; indicating that the preparation methods of this application can all prepare target products with high purity and high yield; and the preparation methods of this application are simple, are homogeneous reactions, do not require the use of expensive catalysts, and there is no water participating in the reaction and no water generated during the entire reaction process; greatly reducing the production cost and reducing the amount of wastewater.
[0038] By using vinyl sulfite and its derivatives as substrates and oxidizing them with isopropyl hydrogen peroxide, vinyl sulfate and its derivatives are obtained, the product does not contain water, and the unreacted isopropyl hydrogen peroxide and the isopropanol generated by the reaction can be well dissolved in an aprotic solvent, so that the purity and yield of the obtained product are both high. This can be verified by the test data of Example 1. In combination with Example 2, the purity of the product can be further improved by evaporating and crystallizing again.
[0039] It can be seen from the test data of Example 1 and Examples 3-4 that when the molar amount of isopropyl peroxide added is 1.02 times that of vinyl sulfite, the reaction is not sufficient, and the purity and yield of the target product are reduced; when the addition amount is increased to more than 1.05 times that of vinyl sulfite, the yield and purity of the target product gradually become equal.
[0040] It can be seen from Example 1 and Examples 5-6 that the reaction of the present application has a high tolerance for reaction solvents, and a variety of aprotic solvents can dissolve the reactants well to allow them to react fully. Compared with Example 1, in Example 6, vinyl sulfite is added dropwise to the isopropyl hydroperoxide solution, and the purity and yield of the obtained target product are both reduced. It is speculated that the reaction is an exothermic reaction, and when the dripped isopropyl hydroperoxide reacts locally, the heat released causes the local solution to heat up, thereby decomposing the local unreacted isopropyl hydroperoxide, thereby reducing the yield and purity of vinyl sulfate. Combined with Comparative Example 1, when the reaction temperature is increased to 60-70°C, the purity and yield of the vinyl sulfate obtained are both low, which can also be further verified.
[0041] Through Example 1 and Example 7, the reaction route and preparation method designed in the present application are applicable to the preparation of various vinyl sulfates and their derivatives.
[0042] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.
Claims
1. A preparation method of ethylene sulfate and its derivatives as electrolyte additives, characterized in that: The preparation method uses ethylene sulfite and its derivatives, and cumyl hydroperoxide as reactants to produce ethylene sulfate and its derivatives and isopropyl alcohol; the reaction general formula is as follows: R1-R4 are hydrogen atoms or C 1-3 alkyl groups .
2. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 1, characterized in that: It includes the following preparation steps: Dissolve the ethylene sulfite and its derivatives in an aprotic solvent, then dropwise add cumyl hydroperoxide, react at 20 - 50 °C, after the reaction ends, concentrate and crystallize to obtain the product, namely the ethylene sulfate and its derivatives.
3. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 2, characterized in that: The molar ratio of the cumyl hydroperoxide to the ethylene sulfite and its derivatives is (1.02 - 1.1):
1.
4. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 2, characterized in that: The mass ratio of the aprotic solvent to the ethylene sulfite and its derivatives is (8 - 15):
1.
5. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 2, characterized in that: The dropping time of the cumyl hydroperoxide is 1 - 3 h, and the reaction time is 0.5 - 1.5 h.
6. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 2, characterized in that: The reaction temperature is 20 - 30 °C.
7. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 2, characterized in that: The concentration and crystallization are carried out by distillation.
8. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 2, characterized in that: The aprotic solvent is one or more of dichloromethane, 1,2 - dichloroethane, chloroform, carbon tetrachloride, dimethyl carbonate, and diethyl carbonate.
9. The preparation method of an electrolyte additive vinylene sulfate and its derivatives according to claim 2, characterized in that: The product is subjected to secondary concentration and crystallization, and the operation is as follows: Dropwise add an aprotic solvent to the obtained product, stir while dropping, dropwise add until it is just completely dissolved, and then carry out evaporation concentration and crystallization to obtain ethylene sulfate and its derivatives.
10. The preparation method of ethylene sulfate and its derivatives as an electrolyte additive according to claim 2, characterized in that: The ethylene sulfate and its ethylene sulfate derivatives are any one of ethylene sulfate, 4 - methyl ethylene sulfate, 4 - ethyl ethylene sulfate, 4 - propyl ethylene sulfate, allyl sulfate, and 1,4 - butanediol sulfate.