PREPARATION METHOD FOR SILICON-BASED COMPOSITE NEGATIVE ELECTRODE MATERIAL FOR LITHIUM BATTERY

摘要

The present invention provides a preparation method for a silicon-based composite negative electrode material for a lithium battery. The method comprises: forming steam under vacuum and heating conditions from a raw material A containing Si and a reducing raw material B capable of reacting to generate silicate; performing condensation deposition in a deposition system after the reaction; and then performing carbon coating to obtain a silicon-based composite material. The inventors have surprisingly discovered that adding a certain amount of alloy into the raw material B can reduce the proportion of crystal regions in the silicon-based composite material, thereby improving an initial coulomb efficiency and cycle stability of the negative electrode material. The preparation method provided by the present invention also has the advantages of simple process, cheap and easily available raw materials, being suitable for large-scale production, and having a high degree of practicability.