A kind of preparation method of porous spherical silicon-based composite negative electrode material

Abstract

The invention discloses a preparation method of a porous spherical silicon-based composite negative electrode material. The method comprises steps of (1) introducing a certain amount of high-purity gaseous silicon tetrachloride into mixed solution A containing metal salt, carbon source precursor and metal-based silicon alloy, hydrolyzing silicon tetrachloride to generate hydrogen chloride and silicon dioxide, under the condition of continuous stirring, dissolving and removing the metal in the metal-based silicon alloy by hydrogen chloride to obtain a porous silicon skeleton matrix, depositingsilicon dioxide generated by hydrolyzing silicon tetrachloride to coat on the porous silicon skeleton, then carrying out hydrothermal reaction to obtain silicon / silicon dioxide particles B which aredoped with metal ions in situ and coated with the carbon source precursor; and (2) carrying out high-temperature treatment of the material B in a protective atmosphere to obtain a lithium ion batterysilicon-based composite negative electrode material with high specific capacity, good cycle performance and excellent rate capability. The method is advantaged in that the method is simple, and the prepared silicon-based composite negative electrode material is good in dispersity, uniform in surface coating, high in specific capacity and good in cycle performance.

Description

technical field

[0001] The invention relates to a method for preparing a porous spherical silicon-based composite negative electrode material, which belongs to the technical field of new energy and new materials. Background technique

[0002] Due to the advantages of high energy density and long cycle life, lithium-ion batteries are currently the most concerned energy storage devices, and have been widely used as power sources for electric vehicles and hybrid vehicles. The performance of the electrode material in the battery is the key to determine the energy density of the lithium-ion battery. Anode materials are an important part of lithium-ion batteries, and their performance directly affects the performance of lithium-ion batteries. However, the theoretical specific capacity of its commercial graphite anode of 372mAh / g is far from meeting the requirements of high energy density anode materials for power batteries. Therefore, it is of great practical significance to deve...

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