▎ 摘　　要

NOVELTY - Preparing graphene-silicon composite material involves heating substrate in vacuum reaction chamber in a protective gas and vacuum condition at 500-1300 degrees C. Vacuumizing is stopped in a reaction chamber and introduction of gaseous carbon source and silicon source gas to a reaction chamber is stopped. The protective gas is continuously introduced in a reaction chamber during heating of substrate. The substrate is cooled at room temperature to obtain graphene-silicon composite material. USE - Method for preparing graphene-silicon composite material used in lithium ion battery (claimed). ADVANTAGE - The preparing graphene-silicon composite material method is simple and improves the production efficiency. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a lithium ion battery, which comprises positive electrode, which comprises current collector, current collector is coated on the upper part of the anode material, positive electrode material comprises a conductive agent, a binder and a positive electrode active material, where positive electrode active material is graphene-silicon composite material; and (2) a method for preparing lithium ion battery, which involves mixing graphene-silicon composite material, adhesive agent and conductive agent in a mass ratio of 80-85:5-10:5-10 to obtain anode material, coating obtained anode material on copper foil, drying and slicing coated copper foil to obtain the anode sheet, sealing anode sheet and positive plate and a membrane in the battery shell, and injecting battery shell into electrolyte to obtain the lithium ion battery.