▎ 摘　　要

NOVELTY - Silicon-graphite composite negative electrode material comprises silicon particles and graphite particles, where the silicon particles are uniformly dispersed in a graphite phase composed of graphite particles to form composite particles. The graphite particles comprises two kinds of graphite particles with different particle size distributions. The graphite particles have a D50 of 1-100 micrometer, and the large-sized graphite particles have a D50 of 20-100 micrometer, small-sized graphite particle D50 is 1-20 micrometer. USE - Silicon-graphite composite negative electrode material used in lithium ion battery (claimed). ADVANTAGE - The silicon-graphite composite negative electrode material has high capacity, high coulomb efficiency, long cycle life, low charging and discharging direct current internal resistance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for preparing a silicon-graphite composite negative electrode material, which involves mixing silicon particles and graphite particles by mechanical mixing to obtain the silicon-graphite composite negative electrode material, where the method of mechanical mixing is selected from mechanical fusion machine, a mixer, a ball mill, a high-speed mixer, a high-speed disperser, and a jet mill; and (2) a lithium ion battery, which comprises a silicon-graphite composite negative electrode material.