Method and system for synthesis of ethylene sulfate, solution and electrolyte containing ethylene sulfate and battery

Abstract

The application relates to the field of batteries, and provides a method and system for synthesizing ethylene sulfate, a solution containing ethylene sulfate, an electrolyte containing ethylene sulfate, and a battery. The method for synthesizing ethylene sulfate comprises the following steps: reacting ethylene sulfite with ozone in the presence of a heterogeneous catalyst and a solvent to obtain a solution containing ethylene sulfate; wherein the solvent comprises a carbonate. The method can efficiently produce an ethylene sulfate electrolyte additive for preparing an electrolyte.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a method and system for synthesizing vinyl sulfate, a solution and electrolyte containing vinyl sulfate, and a battery. Background Technology

[0002] With the rapid development of new energy vehicles, the market demand for power batteries is also increasing. Since adding small amounts of additives to the electrolyte can significantly improve its cycle performance and safety, the research and development of electrolyte additives has attracted much attention. Ethylene sulfate, as an SEI (solid electrolyte interface) film-forming additive, can effectively suppress the decline in the initial capacity of lithium-ion batteries, increase the initial discharge capacity, improve the charge-discharge performance and cycle life of the battery, improve high and low temperature cycle performance, and reduce the thermal expansion of the battery after high-temperature storage. Ethylene sulfate is an electrolyte additive particularly suitable for the cathode material of high-power ternary lithium-ion battery systems. Based on this, the green, efficient, and large-scale synthesis process of ethylene sulfate has also received significant attention.

[0003] Currently, there are five main methods for synthesizing vinyl sulfate: ethylene glycol esterification with sulfuryl chloride or sulfuryl fluoride, dibromoethane substitution, ethylene oxide or ethylene addition with sulfur trioxide, vinyl sulfite oxidation, and synthesis from sulfur trioxide and dioxane. However, these methods all generate large amounts of waste, such as wastewater and waste salts. Furthermore, to obtain vinyl sulfate suitable as an additive in lithium-ion battery electrolytes, the reaction requires multiple refining processes, including washing, extraction, dehydration, crystallization, sublimation, filtration, and drying, to obtain a solid vinyl sulfate product. These methods involve waste treatment and complex refining procedures, leading to high costs and low product yields in the production process. The resulting vinyl sulfate also presents challenges in the complex feeding procedures for preparing electrolytes.

[0004] Therefore, the synthesis process of vinyl sulfate still needs improvement. Summary of the Invention

[0005] This application aims to at least partially address one of the technical problems in the related art.

[0006] The purpose of this application is to provide a method and system for synthesizing vinyl sulfate, a solution containing vinyl sulfate, an electrolyte, and a battery. The method of this application enables efficient and continuous synthesis of vinyl sulfate, and the obtained solution containing vinyl sulfate can be used as an electrolyte additive and directly used in the preparation of electrolytes.

[0007] The first aspect of this application provides a method for synthesizing vinyl sulfate, comprising: reacting vinyl sulfite with ozone in the presence of a heterogeneous catalyst and a solvent to obtain a solution containing vinyl sulfate; wherein the solvent comprises a carbonate. In this method, the use of carbonate as a solvent, combined with a heterogeneous catalyst, promotes the degree of oxidation reaction using vinyl sulfite as a raw material and ozone as an oxidant, thereby increasing the conversion rate of vinyl sulfite and the yield of the product vinyl sulfate. Compared with other oxidants (such as sodium hypochlorite or hydrogen peroxide), using ozone as an oxidant simplifies the product refining process, avoids impurities (such as sodium chloride or water) introduced into the reaction system due to the introduction of other oxidants, and allows the heterogeneous catalyst to directly adsorb ozone, catalyzing the generation of active free radicals, thus increasing the oxidizing activity of ozone and achieving the oxidation of vinyl sulfite. This facilitates the adsorption and desorption of the entire material on the heterogeneous catalyst, improving the degree of reaction. The method of this application produces a solution containing vinyl sulfate with high purity and low byproduct content, which can be directly used to prepare electrolytes. In addition, the method is simple and does not require complicated post-processing purification procedures.

[0008] In some embodiments of this application, the carbonate includes at least one of the chain carbonates shown in Formula 1 and the cyclic carbonates shown in Formula 2:

[0009]

[0010] R1 and R2 are each independently an alkyl group having 1 to 6 carbon atoms; R3 and R4 are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms.

[0011] Optionally, the carbonate includes at least one of dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate.

[0012] In some embodiments of this application, the mass ratio of the solvent to vinyl sulfite is (3-10):1.

[0013] Optionally, the mass ratio of the solvent to vinyl sulfite is (4-6):1. This ensures, on the one hand, that the vinyl sulfite is fully dissolved while suppressing the impact of product precipitation on the reaction apparatus, thus promoting a continuous process; on the other hand, it ensures that the solution has an appropriate DTD concentration, reducing the content of byproducts and facilitating subsequent electrolyte preparation.

[0014] In some embodiments of this application, the molar ratio of ozone to vinyl sulfite is (1-3):1. This increases the degree of reaction of vinyl sulfite and improves product quality.

[0015] In some embodiments of this application, the heterogeneous catalyst includes a supported catalyst, which comprises a support and an active component supported thereon, wherein the support includes at least one selected from γ-Al2O3 support, SiO2 support, TiO2 support and zeolite, and the active component includes a transition metal element.

[0016] In some embodiments of this application, the transition metal element includes at least one of Fe, Cu, Mn, Cr, and Ni.

[0017] In some embodiments of this application, the content of the transition metal element is 5% to 7% by weight, based on the total weight of the supported catalyst. This allows for the distribution of sufficient catalytic active sites on the support, improving reaction efficiency; and also enables control of the oxidation rate, preventing excessively high local temperatures in the reaction apparatus and reducing the possibility of coking and catalyst deactivation.

[0018] In some embodiments of this application, the supported catalyst has an average pore size of 5 nm to 20 nm and a specific surface area of ​​200 m². 2 / g~400m 2 / g. This significantly improves the oxidizing power of ozone and its selectivity for the target product, vinyl sulfate.

[0019] In some embodiments of this application, the reaction is carried out at a temperature of 20°C to 40°C.

[0020] In some embodiments of this application, the reaction is carried out in a fixed-bed reactor. This allows for the synthesis of vinyl sulfate using an efficient, continuous process.

[0021] Optionally, the method includes the following steps: in a fixed-bed reactor packed with the heterogeneous catalyst, vinyl sulfite, solvent and ozone are introduced from the bottom of the fixed-bed reactor, so that the vinyl sulfite, solvent and ozone flow from bottom to top in the reactor to contact the heterogeneous catalyst.

[0022] In some embodiments of this application, the liquid hourly space velocity (LHSV) in the fixed-bed reactor is 0.5 h⁻¹, based on the total amount of vinyl sulfite and solvent. -1 ~3h -1 Optionally, the liquid volume hourly space velocity is 0.5 h⁻¹. -1 ~2.0h -1 This allows for increased production efficiency and reduced equipment investment, while also ensuring timely discharge of products from the reactor, thus promoting the synthesis of higher quality products.

[0023] In some embodiments of this application, the method further includes the following steps: gas-liquid separation and filtration of the product obtained from the fixed-bed reactor to obtain the solution containing vinyl sulfate. This allows for the separation of unreacted gases and any potential catalyst residues, thereby further improving the purity of the target product.

[0024] In some embodiments of this application, ozone is formed by passing oxygen into an ozone generator. This further reduces costs.

[0025] A second aspect of this application provides a system for synthesizing vinyl sulfate, comprising: a fixed-bed reactor; said fixed-bed reactor is used to react vinyl sulfite with ozone in the presence of a heterogeneous catalyst and a solvent to obtain a vinyl sulfate-containing solution, said solvent comprising a carbonate. This system enables the efficient synthesis of vinyl sulfate-containing solutions meeting usage requirements in a continuous process.

[0026] In some embodiments of this application, the fixed-bed reactor has a feed inlet at the bottom and a product outlet at the top; the feed inlet is used to introduce vinyl sulfite, solvent, and ozone into the reactor. This allows the reactants to flow upwards into the reaction space filled with the heterogeneous catalyst, promoting full contact between the materials and the heterogeneous catalyst.

[0027] In some embodiments of this application, the system further includes a gas-liquid separator for separating the products obtained from the fixed-bed reactor into gas and liquid products, respectively.

[0028] In some embodiments of this application, the system further includes a filter for filtering the liquid product obtained from the gas-liquid separator.

[0029] In some embodiments of this application, the system further includes: an ozone supply device; the ozone supply device is used to supply ozone into the fixed-bed reactor.

[0030] Optionally, the ozone supply device includes an oxygen storage tank and an ozone generator, the ozone generator being used to convert oxygen from the oxygen storage tank into ozone.

[0031] A third aspect of this application provides a solution containing vinyl sulfate, prepared by the method described in the first aspect of this application or by the system described in the second aspect of this application.

[0032] In some embodiments of this application, the vinyl sulfate-containing solution has a vinyl sulfate concentration of 10%–28%, a vinyl sulfite content of ≤0.45%, a by-reaction product content of ≤0.25%, a moisture content of ≤40 ppm, an acidity of ≤50 ppm, and a vinyl sulfate purity of ≥99.5%. This further satisfies the requirements for use as an electrolyte additive.

[0033] A fourth aspect of this application provides an electrolyte comprising an electrolyte additive, wherein the electrolyte additive comprises the vinyl sulfate-containing solution described in the third aspect of this application.

[0034] The fifth aspect of this application provides a battery including the electrolyte described in the fourth aspect of this application.

[0035] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0036] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0037] Figure 1 A schematic diagram of an apparatus for synthesizing vinyl sulfate according to an embodiment of this application is shown;

[0038] Figure 2 The NMR spectrum of the product from Example 1;

[0039] Figure 3 This is the gas chromatogram of the product from Example 1.

[0040] Explanation of reference numerals in the attached figures:

[0041] 100: System for synthesizing vinyl sulfate; 1: Oxygen storage tank; 2: Ozone generator; 3: Solvent storage tank; 4: Es storage tank; 5: Fixed bed reactor; 6: Gas-liquid separator; 7: Intermediate product tank; 8: Tail gas treatment device; 9: Filter; 10: Finished product storage tank. Detailed Implementation

[0042] The embodiments of this application are described in detail below. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0043] Oxidation is currently a major method for synthesizing vinyl sulfate (DTD), involving the oxidation of vinyl sulfite (Es) to form DTD. Depending on the type of oxidant, there are six main reaction routes for oxidation: sodium hypochlorite oxidation, sodium periodate oxidation, potassium permanganate oxidation, potassium persulfate oxidation, hydrogen peroxide oxidation, and ozone oxidation. These methods generally suffer from low reactant conversion rates and low product yields. To obtain a qualified product (meeting usage requirements), a series of refining processes are required after the reaction. Taking ozone oxidation as an example, this method requires layering, washing, and drying, or concentration, crystallization, and drying to obtain solid DTD. These processes result in complex production routes and high costs for DTD. Furthermore, solid DTD complicates the subsequent electrolyte preparation process, undoubtedly increasing the electrolyte preparation cost.

[0044] Accordingly, in a first aspect, this application provides a method for synthesizing vinyl sulfate, comprising: reacting vinyl sulfite with ozone in the presence of a heterogeneous catalyst and a solvent to obtain a solution containing vinyl sulfate, wherein the solvent comprises a carbonate.

[0045] In the method of this application, carbonate is used as a solvent and combined with a heterogeneous catalyst, so that the oxidation reaction using vinyl sulfite as a raw material and ozone as an oxidant can effectively synthesize vinyl sulfate, as shown in the following reaction formula:

[0046]

[0047] The reaction has a high conversion rate of vinyl sulfite and can improve the yield of DTD; it results in a solution with high DTD purity and low by-product content, eliminating the need for complex post-processing and other purification processes; the solution containing vinyl sulfite can be directly used for electrolyte preparation.

[0048] In this application, in the presence of the heterogeneous catalyst, carbonates can be directly used as solvents in the reaction of vinyl sulfite with ozone, thereby improving the conversion rate of the reactants and the yield of the products. Specifically, the carbonate can be of a type commonly used in electrolytes. In some embodiments, the carbonate includes at least one of the chain carbonates shown in Formula 1 and the cyclic carbonates shown in Formula 2.

[0049]

[0050] In this configuration, R1 and R2 are each independently an alkyl group having 1 to 6 carbon atoms; R3 and R4 are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms. Furthermore, the number of carbon atoms in an alkyl group having 1 to 6 carbon atoms can specifically be 1, 2, 3, 4, 5, or 6; specific examples of such alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, tert-butyl, and n-pentyl.

[0051] As an example, R1 and R2 are each independently an alkyl group having 1 to 4 carbon atoms.

[0052] As an example, R3 is hydrogen and R4 is an alkyl group having 1 to 6 carbon atoms.

[0053] Optionally, the carbonate includes at least one of dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate.

[0054] In some embodiments, the mass ratio of the solvent to vinyl sulfite can be (3 to 10):1, for example, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc.

[0055] Optionally, the mass ratio of the solvent to vinyl sulfite is (4-6):1. This ensures, on the one hand, that the vinyl sulfite is fully dissolved while suppressing the effect of product precipitation on the reaction apparatus, thus promoting continuous process operation; on the other hand, it ensures that the resulting solution has an appropriate DTD concentration, facilitating subsequent electrolyte preparation.

[0056] In some embodiments, the molar ratio of ozone to vinyl sulfite is (1–3):1, for example, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, etc. Therefore, while controlling raw material costs, the degree of reaction of vinyl sulfite can be increased, thereby improving product quality.

[0057] Optionally, the molar ratio of ozone to vinyl sulfite is (1.5–3):1. This can further reduce the vinyl sulfite content in the product.

[0058] In this application, the heterogeneous catalyst may include a supported catalyst. The supported catalyst comprises a support and an active component supported thereon. Immobilizing the active component (catalyst) can increase the number of catalyst cycles and reduce the catalyst content in the product, thereby improving product quality.

[0059] In some embodiments, the support comprises at least one selected from γ-Al₂O₃, SiO₂, TiO₂, and zeolite (e.g., ZSM-5), and the active component comprises a transition metal element. The transition metal element in the supported catalyst may be present in the form of its oxide. Optionally, the transition metal element comprises at least one selected from Fe, Cu, Mn, Cr, and Ni.

[0060] Generally, based on the total weight of the supported catalyst, the content of the transition metal element (i.e., the "loading") is not less than 5% by weight to achieve effective catalysis. In some embodiments, based on the total weight of the supported catalyst, the content of the transition metal element is 5% to 15% by weight, for example, 5% by weight, 5.5% by weight, 6% by weight, 6.5% by weight, 6.9% by weight, 7% by weight, 7.5% by weight, 7.8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, etc. In this application, the loading can be measured by inductively coupled plasma atomic emission spectrometry (ICP). Further, based on the total weight of the supported catalyst, the content of the transition metal element is 5% to 7% by weight. Thus, on the one hand, sufficient catalytic active sites can be distributed on the support to improve reaction efficiency; on the other hand, the oxidation rate can be controlled to avoid local overheating in the reaction device, reducing the possibility of coking and catalyst deactivation in the reaction system.

[0061] Optionally, the supported catalyst has an average pore size of 5 nm to 20 nm and a specific surface area of ​​200 m². 2 / g~400m 2 / g. In this case, the supported catalyst has a rich porosity structure and a large specific surface area. When applied to the ozone oxidation of vinyl sulfite to prepare vinyl sulfate, it can significantly improve the ozone oxidation capacity and the selectivity for the target product, vinyl sulfate. In this application, the average pore size and specific surface area can be measured by an automated physicochemical adsorption analyzer. Further, the average pore size of the supported catalyst is 5nm to 12nm, and the specific surface area is 250m². 2 / g~350m 2 / g.

[0062] In this application, the supported catalyst can be spherical, cylindrical, or other shapes. From the perspective of meeting filling requirements, the particle size of the spherical catalyst can be 1 mm to 5 mm; the diameter of the cylindrical catalyst can be 1 mm to 5 mm.

[0063] As an example, the supported catalyst may include: CuO / γ-Al2O3, Fe2O3-MnO2 / γ-Al2O, Fe2O3 / zeolite, NiO / γ-Al2O3, Cr2O3 / SiO2, etc.

[0064] In this application, the supported catalyst can be commercially available or prepared by methods well known in the art, such as impregnation-calcination. As an example, the supported catalyst can be prepared by a method including the following steps: impregnating the support with a soluble salt of a transition metal, filtering, and sequentially drying and calcining the resulting solid.

[0065] The impregnation can be carried out at room temperature (20℃~35℃) and the impregnation time can be 6h~24h, for example 6h, 8h, 10h, 12h, 15h, 18h, 20h, 24h.

[0066] The drying temperature can be between 80℃ and 150℃, for example, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 135℃, 140℃, 150℃, etc.; the drying time can be between 3h and 10h, for example, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, etc. Alternatively, the drying can be carried out in an oven.

[0067] The calcination temperature can be between 400℃ and 800℃, for example, 400℃, 500℃, 550℃, 600℃, 700℃, 750℃, 800℃, etc.; the calcination time can be between 3h and 15h, for example, 3h, 4h, 5h, 6h, 8h, 9h, 10h, 12h, 15h, etc. Furthermore, the calcination can be carried out in a muffle furnace.

[0068] In some embodiments, the reaction is carried out at a temperature of 20°C to 40°C, for example, at reaction temperatures of 20°C, 25°C, 30°C, 35°C, 40°C, etc.

[0069] In some embodiments, the reaction is carried out in a fixed-bed reactor. This allows for the efficient and continuous synthesis of vinyl sulfate.

[0070] Optionally, the method includes the following steps: in a fixed-bed reactor packed with the heterogeneous catalyst, vinyl sulfite, solvent and ozone are introduced from the bottom of the fixed-bed reactor, so that vinyl sulfite, solvent and ozone flow from bottom to top in the reactor to contact the heterogeneous catalyst.

[0071] In some embodiments, the liquid hourly space velocity (LHSV) in the fixed-bed reactor is 0.5 h⁻¹, based on the total amount of vinyl sulfite and solvent. -1 ~3h -1 For example, 0.5h -1 1h -1 1.5h -1 2h -1 2.5h -1 3h -1 Etc. Optionally, the liquid volume hourly space velocity (LHSV) is 0.5 h⁻¹. -1 ~2.0h -1 This allows for increased production efficiency and reduced equipment investment, while also ensuring timely discharge of products from the reactor, thus promoting the synthesis of higher quality products.

[0072] In some embodiments, the method further includes the following steps: gas-liquid separation and filtration of the product obtained from the fixed-bed reactor to obtain the solution containing vinyl sulfate. Gas-liquid separation enables the recovery of unreacted gases, and filtration removes catalyst residues that may be carried by the material, thereby not only achieving catalyst recovery and reuse but also improving product quality.

[0073] In some implementations, ozone is generated by passing oxygen into an ozone generator. This can further reduce costs.

[0074] Secondly, this application provides a system for synthesizing vinyl sulfate, comprising: a fixed-bed reactor; the fixed-bed reactor is used to react vinyl sulfite (Es) with ozone in the presence of a heterogeneous catalyst and a solvent to obtain a vinyl sulfate-containing solution, wherein the solvent comprises a carbonate. The system of this application enables the efficient synthesis of a vinyl sulfate-containing solution that meets usage requirements using a continuous process. The vinyl sulfate-containing solution can be a carbonate solution of vinyl sulfate.

[0075] In some embodiments, the fixed-bed reactor has a feed inlet at the bottom and a product outlet at the top. The feed inlet is used to introduce Es, solvent, and ozone. This allows the reactants to flow upwards into the reaction space filled with the heterogeneous catalyst, promoting sufficient contact between the materials and the catalyst. It is understood that the reactor can have one, two, or three feed inlets; that is, Es, solvent, and ozone can enter the reactor through the same feed inlet; or two of the materials can be combined and enter the reactor through the same feed inlet, while the remaining material enters the reactor through another feed inlet; or the three materials can enter the reactor through separate feed inlets.

[0076] In some embodiments, the system further includes a gas-liquid separator for separating the gas and liquid products obtained from the fixed-bed reactor to obtain gaseous and liquid products respectively.

[0077] Optionally, the system further includes a filter for filtering the liquid product obtained from the gas-liquid separator.

[0078] In some embodiments, the system further includes an ozone supply device for supplying ozone into the fixed-bed reactor.

[0079] Optionally, the ozone supply device includes an oxygen storage tank and an ozone generator, the ozone generator being used to convert oxygen from the oxygen storage tank into ozone.

[0080] Additionally, the system may optionally include an exhaust gas treatment device. This device allows for the recycling of solvents, oxygen, and ozone carried in the exhaust gas. This application does not specifically limit the exhaust gas treatment device, as long as it achieves the aforementioned functions. For example, it may include, but is not limited to, one or more combinations of membrane absorption devices, resin adsorption devices, and activated carbon adsorption devices.

[0081] The method described in the first aspect of this application can be performed in the system provided in the second aspect of this application.

[0082] According to a specific implementation method, such as Figure 1 As shown, the system 100 for synthesizing vinyl sulfate includes: an oxygen storage tank 1, an ozone generator 2, a solvent storage tank 3, an ES storage tank 4, a fixed-bed reactor 5, a gas-liquid separator 6, an intermediate product tank 7, a tail gas treatment device 8, a filter 9, and a finished product storage tank 10. Among these,

[0083] Oxygen storage tank 1 is connected to ozone generator 2 to supply oxygen to ozone generator 2;

[0084] The fixed-bed reactor 5 has a reaction space inside that can be filled with a heterogeneous catalyst. The lower part of the fixed-bed reactor 5 is provided with a first feed inlet and a second feed inlet, and the upper part is provided with a product outlet. The first feed inlet is connected to the ozone generator 2 and the solvent storage tank 3 respectively, and the second feed inlet is connected to the Es storage tank 4, so that ozone and solvent enter the reactor through the first feed inlet and Es through the second feed inlet respectively, and flow from bottom to top to contact the heterogeneous catalyst to synthesize vinyl sulfate. The product outlet of the reactor is connected to the tank body of the gas-liquid separator 6 to transport the product (gas-liquid mixture) from the fixed-bed reactor 5 to the gas-liquid separator 6 for gas-liquid separation.

[0085] The gas-liquid separator 6 has a gas outlet at the top and a liquid outlet at the bottom. The gas outlet is connected to the tail gas treatment device 8, and the liquid outlet is connected to the top of the intermediate product tank 7, so that after the product (from the fixed bed reactor 5) is separated by gas and liquid, the resulting liquid (intermediate product) is discharged from the bottom and enters the intermediate product tank 7, and the resulting gas is discharged from the top and enters the tail gas treatment device 8.

[0086] The bottom of the intermediate product tank 7 is connected to the top of the filter 9 so that the intermediate product is discharged from the bottom of the tank and passes through the inside of the filter 9 from top to bottom for filtration;

[0087] The lower part of the filter 9 is connected to the finished product storage tank 10 so that the filtered product (a solution containing vinyl sulfate) is discharged from the lower part and enters the finished product storage tank 10.

[0088] It is understood that in this system, the devices can be connected by conveying pipelines, which may include gas conveying pipelines (e.g., the pipeline between ozone generator 2 and oxygen storage tank 1 and the first raw material inlet), and may also include liquid conveying pipelines (e.g., but not limited to, the pipeline between solvent storage tank 3 and the first raw material inlet, the pipeline between Es storage tank 4 and the second raw material inlet, etc.); at least some of the liquid conveying pipelines may be equipped with conveying pumps.

[0089] As an example, adopt Figure 1 The method for synthesizing vinyl sulfate in the system shown includes the following process flow: A supported catalyst is loaded into a fixed-bed reactor 5, and the reactor is kept at normal temperature and pressure. Ozone, carbonate, and es are introduced into the reactor. The mixture of ozone, carbonate, and es flows from bottom to top and contacts the supported catalyst, so that ozone and es undergo a catalytic oxidation reaction to form a gas-liquid mixture containing vinyl sulfate. The gas-liquid mixture enters a gas-liquid separator 6 to complete the gas-liquid separation. The separated liquid product enters an intermediate product tank 7 and then enters a filter 9 for filtration. The resulting carbonate solution of vinyl sulfate (finished product) is stored in a finished product storage tank 10.

[0090] Thirdly, this application provides a vinyl sulfate-containing solution, prepared by the method described in the first aspect of this application or by the system described in the second aspect of this application. The vinyl sulfate-containing solution meets the requirements for use as an electrolyte additive and can be directly used to prepare an electrolyte. Generally, the solution contains ≤40 ppm water, ≤50 ppm acidity, and ≥99.5% purity of vinyl sulfate.

[0091] In some specific embodiments, the vinyl sulfate-containing solution has a vinyl sulfate concentration of 10%–28%, a vinyl sulfite content of ≤0.45%, a by-reaction product content of ≤0.25%, a moisture content of ≤40 ppm, an acidity of ≤50 ppm, and a vinyl sulfate purity of ≥99.5%. In this embodiment, controlling the vinyl sulfate concentration within a suitable range improves the convenience of electrolyte preparation. For example, according to electrolyte preparation requirements, there is no need to remove excess solvent from the additives, avoiding the complex operation of existing solid DTDs requiring air isolation and manual feeding. It is understood that by-reaction products typically include products that did not participate in the oxidation reaction, such as the decomposition products of the raw material Es and the product DTD.

[0092] Optionally, in the vinyl sulfate-containing solution, the mass concentration of vinyl sulfate is 15% to 23%, the content of vinyl sulfite is ≤0.20%, the content of by-reaction products is ≤0.12%, the moisture content is ≤30ppm, the acidity is ≤20ppm, and the purity of vinyl sulfate is ≥99.6%.

[0093] Fourthly, this application provides an electrolyte comprising an electrolyte additive, wherein the electrolyte additive comprises the vinyl sulfate-containing solution described in the third aspect of this application.

[0094] In this application, the electrolyte may also contain other commonly used components, such as lithium salts, other additives, and optional solvents. This application does not specifically limit the lithium salts; selection can be made by referring to existing lithium-ion electrolytes. Specific examples of lithium salts include, but are not limited to, lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium dioxalatoborate (LiBOB), lithium difluorooxalatoborate (LiDFOB), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium difluorophosphate (LiPO2F2). Other additives include, but are not limited to, film-forming additives and overcharge protection additives; the specific types and amounts can be selected according to the battery application and will not be elaborated here. Furthermore, the amount of solvent added can be selected according to the required concentration of components in the electrolyte. Typically, the DTD content in the electrolyte can be 0.1% to 2% by weight, and the lithium salt concentration can be 0.6 mol / L to 1.5 mol / L.

[0095] In this application, the vinyl sulfate-containing solution can be used directly as an electrolyte additive product, for example, it can be directly mixed with lithium salts, optional other additives, and optional solvents to prepare an electrolyte. The electrolyte can also be efficiently and massively produced through a continuous process. For example, it can be directly produced in… Figure 1 In the system shown, other material metering tanks are connected to the finished product storage tank 10, so that after obtaining the vinyl sulfate electrolyte additive, it can be directly used for the preparation of the electrolyte.

[0096] Fifthly, this application provides a battery including the electrolyte described in the fourth aspect of this application.

[0097] The following specific embodiments illustrate the solution of this application. It should be noted that these embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0098] The following preparation examples illustrate the preparation method of the supported catalyst used in this application.

[0099] The catalyst loading was determined by ICP, and the average pore size and specific surface area were determined by an automated physicochemical adsorption analyzer.

[0100] Preparation Example 1

[0101] 300 g of γ-Al₂O₃ support (Aladdin Biotechnology Co., Ltd.) was weighed and added to a 0.05 mol / L copper acetate aqueous solution at room temperature for 12 h. The sample was filtered, dried at 120 °C for 6 h, and then calcined in a muffle furnace at 500 °C for 6 h. After cooling to room temperature, a spherical CuO / γ-Al₂O₃ supported catalyst was obtained, designated Cat-1. Catalyst Cat-1 has a Cu loading of 6.9 wt%, an average pore size of 6.07 nm, and a specific surface area of ​​304.8 m². 2 / g, with a particle size of 3mm.

[0102] Preparation Example 2

[0103] 300 g of SiO2 support (Aladdin Biotechnology Co., Ltd.) was weighed and added to a 0.06 mol / L chromium sulfate aqueous solution at room temperature for 24 h. The sample was filtered, dried at 110 °C for 8 h, and then calcined in a muffle furnace at 600 °C for 5 h. After cooling to room temperature, a spherical Cr2O3 / SiO2 supported catalyst was obtained, designated Cat-2. Catalyst Cat-2 has a Cr loading of 5.6 wt%, an average pore size of 5.78 nm, and a specific surface area of ​​315.7 m². 2 / g, with a particle size of 3mm.

[0104] Preparation Example 3

[0105] 300 g of zeolite support (ZSM-5, Aladdin Biotechnology Co., Ltd.) was weighed and added to a 0.05 mol / L ferric nitrate aqueous solution at room temperature for 12 h. The sample was filtered, dried at 110 °C for 7 h, and then calcined in a muffle furnace at 550 °C for 12 h. After cooling to room temperature, a spherical Fe₂O₃ / zeolite supported catalyst was obtained, designated Cat-3. The catalyst Cat-3 had an Fe loading of 5.1 wt%, an average pore size of 11.90 nm, and a specific surface area of ​​297.2 m². 2 / g, with a particle size of 3mm.

[0106] The following examples are combined Figure 1 This describes a method for synthesizing vinyl sulfate. Unless otherwise stated, the fixed-bed reactor used is a tubular reactor, and the filter is equipped with a 0.22μm sintered PP filter element.

[0107] Example 1

[0108] Catalyst Cat-1 was loaded into a fixed-bed reactor, maintaining a pressure of 1 atm and a temperature of room temperature. Ozone, Es, and methyl ethyl carbonate were introduced into the fixed-bed reactor to bring them into contact with the catalyst Cat-1. The mass ratio of methyl ethyl carbonate to Es was controlled at 5:1, the molar ratio of ozone to Es at 1.5:1, and the liquid hourly space velocity at 1.0 h⁻¹. -1 The product obtained from the reactor enters a gas-liquid separator for gas-liquid separation at room temperature, causing the gas to overflow from the liquid and enter the tail gas treatment device until the separator returns to atmospheric pressure. At the same time, the liquid enters a filter through an intermediate product tank, and after filtration by the filter element, a methyl ethyl carbonate solution of ethylene sulfate is obtained, which is then sent to the finished product storage tank for storage.

[0109] Example 2-11

[0110] Vinyl sulfate was continuously synthesized according to the method of Example 1, except that the amount of materials and / or liquid hourly space velocity were adjusted (as shown in Table 1) to obtain methyl ethyl carbonate solutions of vinyl sulfate.

[0111] Example 12

[0112] Vinyl sulfate was continuously synthesized according to the method of Example 1, except that the solvent was replaced with dimethyl carbonate to obtain a dimethyl carbonate solution of vinyl sulfate.

[0113] Example 13

[0114] Vinyl sulfate was continuously synthesized according to the method of Example 1, except that the solvent was replaced with diethyl carbonate to obtain a diethyl carbonate solution of vinyl sulfate.

[0115] Example 14

[0116] Vinyl sulfate was continuously synthesized according to the method of Example 1, except that the solvent was replaced with propylene carbonate to obtain a propylene carbonate solution of vinyl sulfate.

[0117] Example 15

[0118] Vinyl sulfate was synthesized continuously according to the method of Example 1, except that catalyst Cat-1 was replaced with catalyst Cat-2.

[0119] Example 16

[0120] Vinyl sulfate was synthesized continuously according to the method of Example 1, except that catalyst Cat-1 was replaced with catalyst Cat-3.

[0121] Comparative Example 1

[0122] Vinyl sulfate was prepared according to the method of Example 1, except that methyl ethyl carbonate was replaced with dichloroethane.

[0123] Comparative Example 2

[0124] Vinyl sulfate was prepared according to the method of Example 1, except that methyl ethyl carbonate was replaced with water.

[0125] Table 1

[0126]

[0127]

[0128] Test case

[0129] The composition of the solutions obtained in the examples and comparative examples was analyzed using the following methods.

[0130] 1) The main components of the solution were analyzed by gas chromatography (GC-2010 gas chromatograph (FID detector)). The contents of vinyl sulfite and by-reaction products were obtained by gas phase area normalization method, and the contents of vinyl sulfate were determined by gas phase external standard method.

[0131] 2) Acidity test: Triethylamine potentiometric titration method;

[0132] 3) Moisture test: Karl Fischer coulometric method;

[0133] 3) Purity test of vinyl sulfate: The purity was tested using a gas chromatograph with the gas phase area normalization method.

[0134] 4) Nuclear magnetic resonance (1HMNR) characterization: frequency 400MHz, solvent CDCl3.

[0135] The test conditions for the gas chromatography analysis are shown in Table 2. The test results are shown in Table 3.

[0136] Table 2

[0137]

[0138] Table 3

[0139]

[0140]

[0141] Note: In Table 3, " / " indicates that it cannot be measured.

[0142] Referring to Tables 1 and 3, compared with the solutions obtained in Examples 1-16 and Comparative Example 1, the method in Examples 1-16 significantly improved the Es conversion rate and the yield of the product DTD: the carbonate solutions of DTD prepared in Examples 1-16 had much lower Es and byproduct contents than those in Comparative Example 1, and the DTD purity was much higher than that in Comparative Example 1. Comparative Example 1 had a low Es conversion rate, and the final product contained excessively high Es content and dichloroethane, making it unsuitable for direct preparation of electrolytes. Furthermore, the reaction in Comparative Example 2, using water as a solvent in the presence of a heterogeneous catalyst, caused hydrolysis of Es and DTD, resulting in a very low product yield (<10%) and the production of a large amount of acidic water.

[0143] The NMR characterization results of the solution in Example 1 are as follows: Figure 2 As shown, the hydrogen at chemical shift 4.76 ppm represents the two hydrogen atoms of the product vinyl sulfate, the hydrogen at chemical shift 4.21 ppm represents the two hydrogen atoms of the methylene group of methyl ethyl carbonate, and the hydrogen atoms at chemical shifts 3.77 ppm and 1.31 ppm represent the two hydrogen atoms of the methyl groups of methyl ethyl carbonate; the gas chromatography results are as follows: Figure 3 As shown, by Figure 3 It can be seen that, apart from the solvent methyl ethyl carbonate (5.177 min) and the product DTD (9.813 min), the product contains only very small amounts of impurities (5.591 min) and Es (6.816 min).

[0144] As can be seen, in the method provided in this application, in the presence of a heterogeneous catalyst, using carbonate as a solvent to react Es and O3 results in a higher conversion rate of Es. The obtained DTD has a purity greater than 99.5%, and no subsequent purification process is required. This solution can be directly used to prepare electrolyte.

[0145] Unless otherwise stated, all technical terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All patents and publications referenced in this application are incorporated herein by reference in their entirety. The terms "comprising" or "including" are open-ended expressions, meaning they include the contents specified in this application but do not exclude other contents.

[0146] In the description of this specification, the reference to terms such as "one embodiment," "another embodiment," etc., means that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0147] Additionally, it should be noted that in this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0148] In the description of this application, it should be understood that the terms "upper part", "lower part", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0149] In this application, unless otherwise expressly specified and limited, the terms "provided with," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0150] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for synthesizing vinyl sulfate, characterized in that, include: In the presence of a heterogeneous catalyst and solvent, vinyl sulfite is reacted with ozone to obtain a solution containing vinyl sulfite; wherein the solvent is a carbonate. The mass ratio of the solvent to vinyl sulfite is (3~10):1; The molar ratio of ozone to vinyl sulfite is (1~3):1; The heterogeneous catalyst is a supported catalyst, comprising a support and an active component supported thereon, wherein the support is selected from... γ -At least one of Al2O3 support, SiO2 support, TiO2 support and zeolite, wherein the active component is a transition metal element; The reaction is carried out in a fixed-bed reactor; The carbonate is selected from at least one of the chain carbonates shown in Formula 1 and the cyclic carbonates shown in Formula 2: Formula 1, Formula 2; R1 and R2 are each independently an alkyl group having 1 to 6 carbon atoms; R3 and R4 are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms. The transition metal element is selected from at least one of Fe, Cu and Cr.

2. The method according to claim 1, characterized in that, The carbonate is selected from at least one of dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate.

3. The method according to claim 1, characterized in that, The mass ratio of the solvent to vinyl sulfite is (4~6):

1.

4. The method according to claim 1, characterized in that, The supported catalyst satisfies at least one of the following conditions: Based on the total weight of the supported catalyst, the content of the transition metal element is 5% to 7% by weight. The supported catalyst has an average pore size of 5 nm to 20 nm and a specific surface area of ​​200 m². 2 / g~400m 2 / g.

5. The method according to claim 1, characterized in that, The reaction was carried out at a temperature of 20°C to 40°C.

6. The method according to claim 5, characterized in that, The method includes the following steps: in a fixed-bed reactor packed with the heterogeneous catalyst, vinyl sulfite, solvent and ozone are introduced from the bottom of the fixed-bed reactor to bring the vinyl sulfite, solvent and ozone into contact with the heterogeneous catalyst.

7. The method according to claim 5, characterized in that, In the fixed-bed reactor, the liquid hourly space velocity (LHSV) is 0.5 h⁻¹, based on the total amount of vinyl sulfite and solvent. -1 ~3 h -1 .

8. The method according to claim 7, characterized in that, In the fixed-bed reactor, the liquid hourly space velocity (LHSV) is 0.5 h⁻¹, based on the total amount of vinyl sulfite and solvent. -1 ~2.0 h -1 .

9. The method according to claim 5, characterized in that, The method also includes the following steps: gas-liquid separation and filtration of the product obtained from the fixed-bed reactor to obtain the solution containing vinyl sulfate.

10. The method according to claim 6, characterized in that, The ozone is formed by passing oxygen into an ozone generator.

11. The method according to claim 1, characterized in that, The fixed-bed reactor has a raw material inlet at the bottom and a product outlet at the top. The raw material inlet is used to introduce vinyl sulfite, solvent and ozone into the reactor.

12. The method according to claim 11, characterized in that, It also includes a gas-liquid separator for separating the gas and liquid products obtained from the fixed-bed reactor to obtain gaseous and liquid products respectively.

13. The method according to claim 12, characterized in that, It also includes a filter for filtering the liquid product obtained from the gas-liquid separator.

14. The method according to claim 11, characterized in that, It also includes an ozone supply device for supplying ozone into the fixed-bed reactor; The ozone supply device includes an oxygen storage tank and an ozone generator, wherein the ozone generator is used to convert oxygen from the oxygen storage tank into ozone.

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