Silicon spiro compound and preparation method and application thereof

Abstract

The invention discloses a silicon spiro compound as well as a preparation method and application thereof. The silicon spiro compound has the following structural formula, the X group and the Y group are respectively and independently selected from any one of an oxygen atom, a carbonyl group, a sulfinyl group, a sulfuryl group, a substituted or unsubstituted C1-C6 alkylene group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C2-C10 alkynyl group, a substituted or unsubstituted C2-C10 cyano group and an aryl group; the silicon spiro compound provided by the invention is suitable for being used as an additive of a lithium ion battery electrolyte, the stability and cycle life of a lithium ion battery can be obviously improved, the reaction condition is mild, and the product purity and yield are high.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organosilicon compounds, and particularly relates to a silicon-based spiro compound and a preparation method and application thereof. BACKGROUND

[0002] In today's highly dependent on electronic equipment era, as the core energy storage components, the performance of lithium ion batteries is crucial. As a key component of lithium ion batteries, electrolyte has a decisive influence on the energy density, charge-discharge efficiency, cycle life and safety of the battery.

[0003] In the current technology, the traditional carbonate-based electrolyte widely used in lithium ion batteries has many limitations, specifically: From the physical property aspect, its flash point is low, and in high temperature environment or battery internal short circuit and other abnormal conditions, it is easy to cause combustion or even explosion, which seriously threatens the safety of the battery and related equipment; at the same time, the viscosity of the traditional carbonate-based electrolyte is large and the ionic conductivity is low in low temperature environment (such as below-20℃), which leads to the sharp decline of the charge-discharge performance of the battery in low temperature environment, and cannot meet the use demand in cold regions or low temperature working conditions; From the chemical stability aspect, the traditional carbonate-based electrolyte is easy to decompose by oxidation under high voltage (> 4.5V vs. Li / Li⁺), and the generated gas products will cause the battery to swell, and will form an unstable passivation film on the electrode surface, increase the internal resistance of the battery, and accelerate the capacity attenuation of the battery. Moreover, the compatibility of the traditional carbonate-based electrolyte with the electrode material (especially high-nickel ternary positive electrode material and metal lithium negative electrode) is poor, which will lead to the dissolution and corrosion of the electrode material, and then affect the long-term stability and cycle life of the battery. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a silicon-based spiro compound and a preparation method and application thereof, which is suitable for being applied as an additive of lithium ion battery electrolyte, can obviously improve the stability and cycle life of the lithium ion battery, and has mild reaction conditions, high product purity and high yield.

[0005] The technical solutions adopted by the present application are as follows: A silicon-based spiro compound, containing the following structural formula: ; the X group and the Y group are independently selected from any one of an oxygen atom, a carbonyl group, a sulfinyl group, a sulfonyl group, a substituted or unsubstituted C1-C6 alkylene group, a substituted or unsubstituted C2-C 10 alkenyl group, a substituted or unsubstituted C2-C 10 alkynyl group, and a substituted or unsubstituted C2-C 10 cyano-containing group and aryl group.

[0006] Preferably, the silicon-based spiro compound comprises the following structure: , , Any one or mixture of several thereof.

[0007] Preferably, a preparation method of the silicon-based spiro compound described above, using silicon tetrahalide as raw material, reacting with nucleophilic reagent in organic solvent environment to obtain reaction product; after post-treatment of the reaction product, the silicon-based spiro compound is obtained.

[0008] Preferably, the silicon tetrahalide uses any one or mixture of several of silicon tetrachloride, silicon tetrabromide, silicon tetrafluoride.

[0009] Preferably, the nucleophilic reagent uses any one or mixture of several of methanedisulfonic acid, 2-fluoromethanedisulfonic acid, 2,2-difluoromethanedisulfonic acid.

[0010] Preferably, the organic solvent comprises any one or mixture of several of ether organic solvent, carbonate organic solvent, carboxylate organic solvent, chlorinated hydrocarbon, alkane, nitrile organic solvent.

[0011] Preferably, the molar ratio of the nucleophilic reagent to the silicon tetrahalide is 2-4:1, preferably 2-2.5:1; and / or the amount of the organic solvent added is 5-15 times, preferably 8-10 times, the weight of the nucleophilic reagent.

[0012] Preferably, the nucleophilic reagent is dispersed in the organic solvent, the temperature is controlled at 0-30℃, more preferably 0-20℃, the silicon tetrahalide is slowly added dropwise, and after the dropwise addition is completed, the reaction is continued for 5-8 hours to make the silicon-based spiro compound achieve complete ring closure.

[0013] Preferably, the post-treatment comprises cooling, filtering, washing, and drying.

[0014] Preferably, an application of the silicon-based spiro compound described above, the silicon-based spiro compound is added to the electrolyte of the battery.

[0015] The silicon-based spiro compound provided in the application has a unique ring structure, which is significantly different from the structure of traditional silicon-based compounds. Not only does it add a new member to the category of silicon-based compounds, but more importantly, the specific silicon-based spiro compound provided in the application is suitable for application as an additive for lithium ion battery electrolyte, which can significantly improve the stability and cycle life of lithium ion batteries. The application further provides a preparation method of the silicon-based spiro compound. The silicon tetrachloride is directly reacted with a suitable nucleophile to obtain a reaction product. The silicon-based spiro compound is obtained after post-treatment of the reaction product. The reaction condition is mild, and the product has high purity and yield. DETAILED DESCRIPTION

[0016] The embodiment provides a silicon-based spiro compound, which has the following structural formula. The X group and the Y group are independently selected from any one or a mixture of two or more of an oxygen atom, a carbonyl group, a sulfinyl group, a sulfonyl group, a substituted or unsubstituted C1-C6 alkylene group, a substituted or unsubstituted C2-C 10 alkenyl group, a substituted or unsubstituted C2-C 10 alkynyl group, a substituted or unsubstituted C2-C 10 cyano-containing group, and an aryl group.

[0017] Preferably, in the embodiment, the silicon-based spiro compound comprises the following structure. , , or a mixture of two or more thereof.

[0018] Preferably, the embodiment provides a preparation method of the silicon-based spiro compound. The silicon tetrachloride is used as a raw material and is reacted with a nucleophile in an organic solvent to obtain a reaction product. The silicon-based spiro compound is obtained after post-treatment of the reaction product. Preferably, in the embodiment, the nucleophile is dispersed in the organic solvent, and the temperature is controlled at 0-30°C (more preferably 0-20°C, and further more preferably 0-10°C). The silicon tetrachloride is slowly added dropwise, and the reaction is continued for 5-8 hours after the dropwise addition is completed, so that the silicon-based spiro compound is completely ring-closed.

[0019] Preferably, in the embodiment, the silicon tetrachloride is any one or a mixture of two or more of silicon tetrachloride, silicon tetrabromide, and silicon tetrafluoride. Preferably, in the embodiment, the nucleophile is any one or a mixture of two or more of methanedisulfonic acid, 2-fluoromethanedisulfonic acid, and 2,2-difluoromethanedisulfonic acid.

[0020] Preferably, in the embodiment, the organic solvent comprises any one or a mixture of two or more of an ether organic solvent, a carbonate organic solvent, a carboxylate organic solvent, a chlorinated hydrocarbon, an alkane, and a nitrile organic solvent.

[0021] Preferably, in the embodiment, the molar ratio of the nucleophile to the silicon tetrachloride is 2-4:1, and more preferably 2-2.5:1. The amount of the organic solvent added is 5-15 times the weight of the nucleophile, and more preferably 8-10 times.

[0022] Preferably, the post-treatment includes cooling (preferably cooling the reaction product to -10 to 0°C), filtration, washing with fresh organic solvent to remove byproducts, and drying (preferably vacuum drying).

[0023] Preferably, this embodiment proposes an application of the silicon-based spirocyclic compound described above, in which the silicon-based spirocyclic compound is added to the electrolyte of a battery.

[0024] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0025] Based on the above-described implementation schemes, this application further proposes the following specific embodiments: First, it should be noted that the reagent raw materials used in the following specific embodiments and comparative examples of the present invention are sourced from the following: Unless otherwise specified, all raw materials are ordinary commercially available products.

[0026] The test methods used in the specific embodiments and comparative examples of this invention are as follows: Nuclear magnetic resonance (NMR) analysis was performed using a Bruker AVANCE II 400 MHz spectrometer. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] Example 1: A certain amount of methanedisulfonic acid (as a nucleophile) was dispersed in acetonitrile (as an organic solvent), and silicon tetrachloride was slowly added dropwise while maintaining the temperature at 0°C. After the addition was completed, the reaction was continued at this temperature for 6 hours to achieve complete ring closure of the silicon-based spirocyclic compound. The molar ratio of methanedisulfonic acid to silicon tetrachloride was 2.1:1, and the weight ratio of acetonitrile to methanedisulfonic acid was 10:1. After the reaction was completed, the reaction product was cooled to -5°C and washed multiple times with fresh acetonitrile and dichloromethane during filtration to remove byproducts. The filter cake was then vacuum dried at 30°C to obtain a silicon-based spirocyclic compound with the following structural formula: ; The silicon-based spirocyclic compounds synthesized above were characterized by NMR (1H, 13C): 1H NMR: δ 6.32 (4H, s); 13C NMR: δ 45.5 (2C, s).

[0028] Example 2: A certain amount of 2-fluoromethyldisulfonic acid (as a nucleophile) was dispersed in acetonitrile (as an organic solvent), and silicon tetrachloride was slowly added dropwise while maintaining the temperature at 0°C. After the addition was completed, the reaction was continued at this temperature for 7 hours to achieve complete cyclization of the silicon-based spirocyclic compound. The molar ratio of 2-fluoromethyldisulfonic acid to silicon tetrachloride was 2.0:1, and the weight ratio of acetonitrile to 2-fluoromethyldisulfonic acid was 10:1. After the reaction was completed, the reaction product was cooled to -5°C and washed multiple times with fresh acetonitrile and dichloromethane during filtration to remove byproducts. The filter cake was then vacuum dried at 30°C to obtain a silicon-based spirocyclic compound with the following structural formula: ; The silicon-based spirocyclic compounds synthesized above were characterized by NMR (1H, 13C): 1 ¹H NMR: δ 7.89 (2H, s); 13 C NMR: δ 73.2 (2C, s).

[0029] Example 3: A certain amount of 2,2-difluoromethyldisulfonic acid (as a nucleophile) was dispersed in acetonitrile (as an organic solvent), and silicon tetrachloride was slowly added dropwise while maintaining the temperature at 20°C. After the addition was completed, the reaction was continued at this temperature for 5 hours to achieve complete cyclization of the silicon-based spirocyclic compound. The molar ratio of 2,2-difluoromethyldisulfonic acid to silicon tetrachloride was 2.0:1, and the weight ratio of acetonitrile to 2,2-difluoromethyldisulfonic acid was 10:1. After the reaction was completed, the reaction product was cooled to -10°C. During filtration, the product was washed multiple times with fresh acetonitrile and dichloromethane to remove byproducts. The filter cake was then vacuum dried at 30°C to obtain a silicon-based spirocyclic compound with the following structural formula: ; The silicon-based spirocyclic compounds synthesized above were characterized by NMR (13C): 13 C NMR: δ 150.5 (2C,s), no H signal.

[0030] Example 4: The remaining technical solutions of Example 4 are the same as those of Example 1, except that in Example 4, the temperature is controlled at 5°C and the heat preservation reaction time is 9 hours.

[0031] Example 5: The remaining technical solutions of Example 5 are the same as those of Example 1, except that in Example 5, the temperature is controlled at 10°C and the heat preservation reaction time is 4 hours.

[0032] Comparative Example 1: The rest of the technical solutions of Comparative Example 1 are the same as those of Example 1, except that in Comparative Example 1, the temperature is controlled at 25°C and the heat preservation reaction time is 10 hours.

[0033] Comparative Example 2: The rest of the technical solutions of Comparative Example 2 are the same as those of Example 1, except that in Comparative Example 2, the temperature is controlled at 30°C and the heat preservation reaction time is 10 hours.

[0034] Comparative Example 3: Using the spirocyclic organosilicon compound 1 provided in Example 1 of patent CN106220667B: .

[0035] The purity and yield of the products from Examples 1-5 and Comparative Examples 1-2 are shown in Table 1 below:

[0036] As can be seen from Table 1 above, the reaction conditions proposed in the embodiments of this application are mild, and the product purity and yield are high.

[0037] To further verify the application effects achieved in Embodiments 1-3 of this application, the following comparative application experiments were conducted on the products provided in Embodiments 1-3 and Comparative Example 3 respectively: The pouch cells corresponding to Examples 1-3 and Comparative Example 3 were fabricated according to the following steps: Electrolyte preparation: Prepared in a glove box under N2 atmosphere; the water content of the organic solvent system is <10 ppm; the electrolyte includes: The organic solvent system with a mass fraction of 84.5% is specifically composed of diethyl carbonate (DEC): ethyl methyl carbonate (EMC): dimethyl carbonate (DMC) in a mass ratio of 1:1:1 (wt%). The lithium salt system uses 1.0 mol·L⁻¹ -1 Lithium hexafluorophosphate (LiPF6); The products provided in Examples 1-3 and Comparative Example 3 were selected respectively, and the product accounted for 2% of the electrolyte by mass. The rest are other additives, specifically composed of ethylene carbonate (VC): fluoroethylene carbonate (FEC): propanesulfonate lactone (PS): methylene dimethyl sulfonate (MMDS) = 2:1:1:1 (wt%). After the raw materials of the organic solvent system are mixed evenly in a fixed ratio, the mixture is frozen and cooled for 1.5-2 hours to obtain an organic solvent mixture. The lithium salt system is added and mixed evenly. Finally, the products provided in Examples 1-3 and Comparative Example 3, as well as other additives, are added and mixed evenly for later use.

[0038] Preparation of the battery positive electrode: Using methylpyrrolidone (NMP) as a solvent, 2% (w / w) of polyvinylidene fluoride (PVDF) was uniformly dispersed to obtain a mixture. Then, 2% (w / w) of carbon nanotubes (CNTs) were added and uniformly mixed. Next, 96% (w / w) of the positive electrode active material (lithium cobalt oxide, LiCoO2) was added and mixed uniformly. The mixture was then uniformly coated onto aluminum foil using a coating machine. After drying, rolling, and cutting, the positive electrode sheet was formed with an areal density ranging from 350-450 g / cm³. 2 (Double-sided); Preparation of the battery negative electrode: Using deionized water as a solvent, 1% by mass of carboxymethyl cellulose (CMC) is uniformly dispersed to obtain a mixture. Then, 2% by mass of conductive carbon black (SP) and 96% by mass of negative electrode active material (specifically, vapor-deposited silicon carbon, material type SH-SO2) are added and uniformly mixed. Finally, 1% by mass of styrene-butadiene rubber (SBR) is added and uniformly mixed. After uniform mixing, the mixture is evenly coated onto copper foil using a coating machine. After drying, rolling, and cutting, the negative electrode sheet is formed with an areal density ranging from 200-350 g / cm³. 2 (Double-sided); To further demonstrate the effectiveness of the implementation, this application also includes the following comparative examples 4, 5, and 6: Comparative Example 4: The soft-pack battery solution prepared in Comparative Example 4 is the same as that in Example 1, except that the product in Example 1 is replaced with the additive methyl methyl disulfonate (MMDS) in Comparative Example 4.

[0039] Comparative Example 5: The soft-pack battery solution prepared in Comparative Example 5 is the same as that in Example 1, except that the product in Example 1 is replaced with the additive propanesulfonate lactone (PS) in Comparative Example 5.

[0040] Comparative Example 6: The soft-pack battery solution prepared in Comparative Example 6 is the same as that in Example 1, except that the product in Example 1 is replaced with the additive lithium difluorophosphate LiPO2F2.

[0041] Therefore, we obtained pouch cells assembled from electrolytes provided in Examples 1-3 and Comparative Examples 3-6 as specific additives, with each pouch cell using 25g of electrolyte. Then, we conducted the following performance comparison tests on each pouch cell: Four groups of each soft-pack battery corresponding to Examples 1-3 and Comparative Examples 3-6 were prepared. Each group was subjected to a 500-cycle test at 25°C and 45°C, and a 35-day storage test at -20°C and 55°C, respectively. The charge and discharge conditions used in each cycle test were: a charge / discharge rate of 1C / 1C and a voltage range of 3.0V-4.5V. The measured capacity retention rates of the lithium-ion batteries are shown in Table 2 below:

[0042] To further enhance the effectiveness of the silicon-based spirocyclic compounds provided in the above embodiments of this application in lithium-ion batteries, this embodiment also proposes a lithium-ion battery electrolyte based on silicon-based spirocyclic compounds, including an organic solvent system, a lithium salt system, and an additive system; the organic solvent system includes at least one cyclic carbonate and at least one chain carbonate; the additive system includes a silicon-based spirocyclic compound, wherein the silicon-based spirocyclic compound is the silicon-based spirocyclic compound provided in the above embodiments of this application.

[0043] Preferably, in this embodiment, the silicon-based spirocyclic compound accounts for 0.5-5% of the electrolyte mass fraction of the lithium-ion battery; more preferably, it is 1-4%.

[0044] Preferably, in this embodiment, the cyclic carbonate accounts for 15-35% of the mass fraction of the electrolyte in the lithium-ion battery; the chain carbonate accounts for 55-75% of the mass fraction of the electrolyte in the lithium-ion battery; preferably, in this embodiment, the cyclic carbonate is ethylene carbonate EC and / or propylene carbonate PC; the chain carbonate is ethyl methyl carbonate EMC and / or dimethyl carbonate DMC and / or diethyl carbonate DEC.

[0045] Preferably, in this embodiment, the lithium salt system includes any one or a mixture of several of lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(oxalateborate)borate (LiBOB), and lithium tetrafluoroborate (LiBF4); preferably, in this embodiment, the concentration of the lithium salt system in the lithium-ion battery electrolyte is 0.8-1 mol·L⁻¹. -1 .

[0046] Preferably, in this embodiment, the additive system further includes the combined use of at least two of the following: lithium difluorooxalate borate (LiODFB), ethylene carbonate (VC), fluoroethylene carbonate (FEC), ethylene sulfate (DTD), propanesulfonate lactone (PS), lithium difluorophosphate (LiPO2F2), and methylene disulfonate (MMDS), which account for 0.5-5% of the mass fraction of the lithium-ion battery electrolyte.

[0047] Preferably, this embodiment proposes a method for preparing a lithium-ion battery electrolyte based on silicon-based spirocyclic compounds as described above. The method involves mixing the raw materials of an organic solvent system to obtain an organic solvent mixture, freezing the organic solvent mixture for 1-3 hours, adding a lithium salt system to the organic solvent mixture for mixing, and finally adding an additive system for mixing to obtain the lithium-ion battery electrolyte.

[0048] Preferably, this embodiment also proposes a ternary lithium-ion battery, employing a lithium-ion battery electrolyte based on a silicon-based spirocyclic compound as described above; its positive electrode active material includes a nickel-cobalt-manganese ternary material (LiNi) as the ternary positive electrode material. x Co y Mn 1-x-y O2, NCM); More preferably, in this embodiment, the nickel-cobalt-manganese ternary material is NCM811, which means that the ratio between N (representing nickel), C (representing cobalt), and M (representing manganese) is 8:1:1.

[0049] To further verify the effectiveness of the electrolyte for ternary lithium-ion batteries proposed in the above embodiments of this application, this application further provides the following embodiments and comparative examples: Example 6: An electrolyte for a ternary lithium-ion battery, comprising: The organic solvent system with a mass fraction of 84.5% is specifically composed of ethylene carbonate EC: ethyl methyl carbonate EMC: dimethyl carbonate DMC = 3:3:4 (wt%). The lithium salt system uses 1.0 mol·L⁻¹ -1 Lithium hexafluorophosphate (LiPF6); Example 1 provides a product with a mass fraction of 2%; The remainder consists of other additives, specifically composed of ethylene carbonate (VC): fluoroethylene carbonate (FEC): propanesulfonate lactone (PS): methylene dimethyl sulfonate (MMDS) = 2:1:1:1 (wt%). The electrolyte is prepared in a glove box under N2 atmosphere, ensuring that the water content of the solvent system is <10ppm. During preparation, the raw materials of the organic solvent system are first mixed evenly in a fixed ratio, and then the mixture is cooled to a freezing temperature of 1.5-2 hours to obtain an organic solvent mixture. The lithium salt system is then added and mixed evenly. Finally, the product provided in Example 1 and other additives are added and mixed evenly before use.

[0050] Example 7: The remaining technical solutions of Example 7 are the same as those of Example 6, except that in Example 7, the product provided in Example 2 is used instead of the product provided in Example 1.

[0051] Example 8: The remaining technical solutions of Example 8 are the same as those of Example 6, except that in Example 8, the product provided in Example 3 is used instead of the product provided in Example 1.

[0052] Comparative Example 7: The remaining technical solutions of Comparative Example 7 are the same as those of Example 6, except that in Comparative Example 7, the product provided by Comparative Example 3 is used instead of the product provided by Example 1.

[0053] Comparative Example 8: The remaining technical solutions of Comparative Example 8 are the same as those of Example 6, except that in Comparative Example 8, the organic solvent system is specifically composed of ethylene carbonate EC: propylene carbonate PC = 1:1 (wt%).

[0054] Then, the pouch cells corresponding to Examples 6-8 and Comparative Examples 7-8 were fabricated according to the following steps: Preparation of the battery positive electrode: Using methylpyrrolidone (NMP) as a solvent, 2% (w / w) of polyvinylidene fluoride (PVDF) was uniformly dispersed to obtain a mixture. Then, 2% (w / w) of carbon nanotubes (CNTs) were added and uniformly mixed. Next, 96% (w / w) of the positive electrode active material (using a ternary system NCM811) was added and mixed evenly. The mixture was then uniformly coated onto aluminum foil using a coating machine. After drying, rolling, and cutting, the positive electrode sheet was formed with an areal density ranging from 350-450 g / cm³. 2 (Double-sided); Preparation of the battery negative electrode: Using deionized water as a solvent, 1% by mass of carboxymethyl cellulose (CMC) is uniformly dispersed to obtain a mixture. Then, 2% by mass of conductive carbon black (SP) and 96% by mass of negative electrode active material (specifically graphite) are added and uniformly mixed. Finally, 1% by mass of styrene-butadiene rubber (SBR) is added and uniformly mixed. After uniform mixing, the mixture is evenly coated onto copper foil using a coating machine. After drying, rolling, and cutting, the negative electrode sheet is formed with an areal density ranging from 200-350 g / cm³. 2 (Double-sided); Therefore, we obtained: NCM811|| graphite pouch batteries assembled from electrolytes provided by Examples 6-8 and Comparative Examples 7-8 respectively as specific additives, with each pouch battery using 25g of electrolyte. To further demonstrate the application effect of the embodiments of this application in a specific ternary system of NCM811, this application also provides the following embodiment 9: Example 9: The remaining technical solutions of Example 9 are the same as those of Example 6, except that in the soft-pack battery of Example 9, the positive electrode active material is a ternary system NCM622, and the corresponding NCM622||graphite soft-pack battery is assembled.

[0055] Then, the following performance comparison tests were conducted on each pouch battery: Four groups of each soft-pack battery corresponding to Examples 6-9 and Comparative Examples 7-8 were prepared. Each group was subjected to a 500-cycle test at 25°C and 45°C, and a 35-day storage test at -20°C and 55°C, respectively. The charge and discharge conditions used in each cycle test were: a charge / discharge rate of 1C / 1C. The voltage range of the NCM811|| graphite soft-pack battery was 2.75V-4.2V, and the voltage range of the NCM622|| graphite soft-pack battery was 2.75V-4.4V. The measured capacity retention rates of lithium-ion batteries are shown in Table 3 below:

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A silicon-based spirocyclic compound, characterized in that, It contains the following structural formula: The X and Y groups are independently selected from oxygen, carbonyl, thionyl, thionyl, substituted or unsubstituted C1-C6 alkylene, substituted or unsubstituted C2-C6 alkylene, respectively. 10 alkenyl, substituted or unsubstituted C2-C 10 Alkyne group, substituted or unsubstituted C2-C 10 Contains either a cyano group or an aryl group.

2. The silicon-based spirocyclic compound according to claim 1, characterized in that, The silicon-based spirocyclic compound has the following structure: , , Any one or a mixture of several of them.

3. A method for preparing a silicon-based spirocyclic compound according to claim 1 or 2, characterized in that, Silicon tetrahalide was used as a raw material and reacted with a nucleophile in an organic solvent environment to obtain the reaction product; the reaction product was then post-treated to obtain the silicon-based spirocyclic compound.

4. The method for preparing the silicon-based spirocyclic compound according to claim 3, characterized in that, The silicon tetrahalide is any one or a mixture of silicon tetrachloride, silicon tetrabromide, and silicon tetrafluoride.

5. The method for preparing the silicon-based spirocyclic compound according to claim 3, characterized in that, The nucleophile is any one or a mixture of several of methyl disulfonic acid, 2-fluoromethyl disulfonic acid, and 2,2-difluoromethyl disulfonic acid.

6. The method for preparing the silicon-based spirocyclic compound according to claim 5, characterized in that, The organic solvent includes any one or a mixture of several of the following: ether organic solvents, carbonate organic solvents, carboxylic acid ester organic solvents, chlorinated hydrocarbons, alkanes, and nitrile organic solvents.

7. The method for preparing the silicon-based spirocyclic compound according to claim 3, characterized in that, The molar ratio of the nucleophile to the silicon tetrahalide is 2-4:1, preferably 2-2.5:1; and / or the amount of the organic solvent added is 5-15 times the weight of the nucleophile, preferably 8-10 times.

8. The method for preparing the silicon-based spirocyclic compound according to claim 3, characterized in that, The nucleophile is dispersed in an organic solvent, and the temperature is controlled at 0-30℃. Silicon tetrahalide is slowly added dropwise. After the addition is complete, the reaction is continued at this temperature for 5-8 hours to achieve complete cyclization of the silicon-based spirocyclic compound.

9. The method for preparing the silicon-based spirocyclic compound according to claim 3, characterized in that, The post-processing includes cooling, filtration, washing, and drying.

10. The application of a silicon-based spirocyclic compound according to any one of claims 1-2, characterized in that, The silicon-based spirocyclic compound is added to the electrolyte of the battery.

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