COMPOSITE NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION BATTERY, PREPARATION METHOD THEREOF, AND USE THEREOF IN LITHIUM ION BATTERY

The present application provides a composite negative electrode material of a lithium ion battery, a preparation method thereof and the use thereof in a lithium ion battery. The composite negative electrode material includes a SiO-based active material and a polycarbonate coating layer coated on a surface of the SiO-based active material. The method includes: (1) preparing a monomer solution of unsaturated carbonate; (2) polymerizing the monomer in presence of a polymerization catalyst to obtain a polymer solution; and (3) adding a SiO-based active material, water and a polymer catalyst to the polymer solution, and further polymerizing to coat the SiO-based active material, to obtain the composite negative electrode material.