CN-116444553-B - Preparation method and application of trimethylsilyl compound

CN116444553BCN 116444553 BCN116444553 BCN 116444553BCN-116444553-B

Abstract

The invention discloses a preparation method and application of a trimethylsilyl compound, and relates to the technical field of lithium ion battery additives. The preparation method comprises the steps of adding 4-bromodiphenyl ketone, bis (triphenylphosphine) palladium chloride, triphenylphosphine and cuprous iodide into a container, adding triethylamine and tetrahydrofuran to dissolve the materials, adding trimethylethynyl silicon to react, and treating the materials to obtain a product A, adding the product A and zinc powder into the container, adding tetrahydrofuran, cooling the materials, adding titanium tetrachloride to react after cooling, and treating the reacted materials to obtain the trimethylsilyl compound. The trimethyl silicon-based compound prepared by the invention has the capability of capturing water or acid, has low density, can be used as an additive for a lithium ion battery, can improve the capacity retention rate of the battery, improve the stability of an electrode material, can reduce the charge transfer impedance of the electrode, improve the discharge capacity ratio of the electrode and improve the performance of the lithium ion battery.

Inventors

GAO QINGQING
YE PENG
ZHANG MINSHU
ZHONG XUHANG

Assignees

厦门理工学院

Dates

Publication Date: 20260508
Application Date: 20230423

Claims (7)

1. The application of the trimethylsilyl compound in the lithium ion battery is characterized in that the preparation method of the trimethylsilyl compound comprises the following steps: S1, adding 4-bromodiphenyl ketone, bis (triphenylphosphine) palladium chloride, triphenylphosphine and cuprous iodide into a dried container, pumping the container to a vacuum state, then charging nitrogen, adding triethylamine and tetrahydrofuran into the container, heating to 50 ℃ for dissolution, adding trimethylethynyl silicon into the container, and reacting for 12 hours at 50 ℃; s2, drying the solvent after the reaction in the step S1, extracting and drying the obtained reaction product, removing the extraction solvent to obtain a crude product, and separating and purifying the crude product to obtain a product A; S3, adding the product A and zinc powder obtained in the step S2 into a dried container, vacuumizing the container, filling nitrogen, adding tetrahydrofuran into the container, cooling in an ice bath, adding titanium tetrachloride into the container after cooling, removing the ice bath, reacting for half an hour, then heating to 70 ℃, and stirring for reacting for 12 hours; s4, adding dilute hydrochloric acid into a container after the reaction in the step S3, drying a solvent, extracting and drying the obtained product, removing the extraction solvent to obtain a crude product, and separating and purifying the crude product to obtain a final product trimethylsilyl compound; The synthetic route is as follows: 。
2. The application of the trimethylsilyl compound in a lithium ion battery as claimed in claim 1, wherein the molar ratio of the 4-bromobenzophenone to the trimethylethynyl silicon in the step S1 is 10:13.
3. The application of the trimethylsilyl compound in the lithium ion battery as claimed in claim 1, wherein the molar use ratio of the bis (triphenylphosphine) palladium chloride, the triphenylphosphine to the cuprous iodide in the step S1 is 1:3:2.
4. The application of the trimethylsilyl compound in the lithium ion battery as claimed in claim 1, wherein the molar ratio of the product A to the zinc powder to the titanium tetrachloride in the step S3 is 1:1:1.
5. The application of the trimethylsilyl compound in the lithium ion battery as set forth in claim 1, wherein the step S2 and the step S4 are both performed with compressed air to dry the solvent.
6. The use of a trimethylsilyl compound in a lithium ion battery according to claim 1, wherein the extraction and drying operations in step S2 and step S4 are both extraction of the reaction product with dichloromethane and water, and drying with anhydrous magnesium sulfate after combining the organic layers.
7. The method of claim 1, wherein the step S2 and the step S4 are performed with a rotary evaporator to remove the extraction solvent to obtain a crude product, and the crude product is purified by column chromatography, wherein the eluent is a mixed solvent of n-hexane/dichloromethane.

Description

Preparation method and application of trimethylsilyl compound Technical Field The invention relates to the technical field of lithium ion battery additives, in particular to a preparation method and application of a trimethylsilyl compound. Background Lithium ion batteries with layered transition metal oxide cathodes and graphite anodes are ubiquitous in portable electronics and electric vehicles due to their excellent cycling stability and high energy, and during electrochemical cycling of such batteries, lithium ions are deintercalated from one electrode and then inserted into the other electrode with high efficiency and reversibility. Lithium ion batteries have been commercialized since 1991, layered oxides such as LiMO 2 (where m=co, ni, mn) are the cathode material of choice in commercial batteries, but to further increase energy density, the cathode material needs to operate at voltages exceeding 4.0V without performance degradation during battery aging. Li Ni xMnyCozO2 (x+y+z=1) cathode is of great interest because of its adjustable nature, sufficient to balance the energy density, safety and cycling stability of the cell, the cathode-electrolyte interface contributing most to the cathode impedance, which in turn is a major component of the full cell impedance. As the battery ages, the cathode and full cell impedance gradually increases, eventually reaching a value at which the charge and discharge of the battery becomes extremely slow, a phenomenon known as "impedance rise". In order to increase the energy density of a lithium ion battery, it is necessary to operate the layered lithiated oxide cathode at a potential of Li/Li + exceeding 4V. However, when continuously exposed to such high potentials, the battery materials gradually age, requiring protection by electrolyte additives. In order to strengthen the surface protection of the battery and improve the battery performance, the invention provides a preparation method and application of a trimethylsilyl compound. Disclosure of Invention The invention aims to provide a preparation method and application of a trimethylsilyl compound, wherein the prepared trimethylsilyl compound has the capability of capturing moisture or acid and lower density, and can be used as an additive for a lithium ion battery, so that the capacity retention rate of the battery can be improved, the stability of an electrode material can be improved, the charge transfer impedance of the electrode can be reduced, the discharge capacity ratio of the electrode can be improved, and the performance of the lithium ion battery can be improved. In order to achieve the above object, the present invention provides a method for preparing a trimethylsilyl compound, comprising the steps of: S1, adding 4-bromodiphenyl ketone, bis (triphenylphosphine) palladium chloride, triphenylphosphine and cuprous iodide into a dried container, pumping the container to a vacuum state, then charging nitrogen, adding triethylamine and tetrahydrofuran into the container, heating to 50 ℃ for dissolution, adding trimethylethynyl silicon into the container, and reacting for 12 hours at 50 ℃; s2, drying the solvent after the reaction in the step S1, extracting and drying the obtained reaction product, removing the extraction solvent to obtain a crude product, and separating and purifying the crude product to obtain a product A; S3, adding the product A and zinc powder obtained in the step S2 into a dried container, vacuumizing the container, filling nitrogen, adding tetrahydrofuran into the container, cooling in an ice bath, adding titanium tetrachloride into the container after cooling, removing the ice bath, reacting for half an hour, then heating to 70 ℃, and stirring for reacting for 12 hours; s4, adding dilute hydrochloric acid into a container after the reaction in the step S3, drying a solvent, extracting and drying the obtained product, removing the extraction solvent to obtain a crude product, and separating and purifying the crude product to obtain a final product trimethylsilyl compound; The synthetic route is as follows: preferably, the molar usage ratio of the 4-bromobenzophenone to the trimethylethynyl silicon in the step S1 is 10:13. Preferably, in the step S1, the molar use ratio of the bis (triphenylphosphine) palladium chloride, the triphenylphosphine and the cuprous iodide is 1:3:2. Preferably, the molar ratio of the product A, zinc powder and titanium tetrachloride in the step S3 is 1:1:1. Preferably, both the step S2 and the step S4 are performed by drying the solvent with compressed air. Preferably, the extraction and drying operations in the step S2 and the step S4 are both extraction of the reaction product with dichloromethane and water, and drying of the combined organic layers with anhydrous magnesium sulfate. Preferably, in both the step S2 and the step S4, the extraction solvent is removed by using a rotary evaporator to obtain a crude product, and the crude product is purified by