The invention provides
lithium ion battery
silicon substrate composite negative
electrode materials and a preparation method of the
lithium ion battery
silicon substrate composite negative
electrode materials, and belongs to the technical field of
lithium ion batteries. The prepared
lithium ion battery silicon substrate composite negative
electrode materials comprise, 23-56 wt% of silicon, 12.1-75.4 wt% of
magnesium oxide and 2-12 wt% of
graphene. A magnesiothermic reduction method is adopted, and
magnesium powder serves as a
reducing agent for reducing
oxide of silicon (SiOx, and x is larger than 0.5 and smaller than 2) to prepare silicon /
magnesium oxide composite materials. Then, the magnesium oxide attached on a
reaction product on the surface of the silicon serves as a catalyst. A
carbon source is adopted to carry out
catalytic chemical vapor deposition so as to generate the
graphene. The silicon / magnesium /
graphene composite negative electrode materials are prepared. According to a prepared silicon substrate
lithium ion battery, after magnesiothermic reduction is carried out on the oxide of the silicon, the magnesium oxide is generated on the interior of the oxide of the silicon, a
volume effect of the silicon is relieved, the magnesium oxide generated on the interior and the exterior of the oxide of the silicon has the function of the catalyst, the graphene is catalyzed and generated, the
volume effect of the silicon can be further relieved, and electrical
conductivity of the materials is remarkably strengthened.