A porous silicon / carbon composite material, preparation method and use thereof

The present invention relates to a porous silicon / carbon composite material, preparation method and application, technical field belonging to the lithium ion battery. Specific components and weight percents of the composite material: a carbon content representing 0% to 80%, a silicon content representing 20 to 100%, a pore size of porous silicon is 0.01nm ~ 10μm, the particle size of the porous silicon / carbon composite material is 10 nm ~ 50μm. Rice husk as the raw material, the metal thermal reduction method and purified to obtain a silicon / carbon composite having a porous structure. The composite material may be directly used as the negative electrode material a lithium ion battery, the negative electrode may be mixed with other materials used as the anode material. The material is non-porous silicon as compared with the negative electrode material, has greatly improved cycling stability. The present invention utilizes a rich source of inexpensive, readily available biomass as a feedstock, a low cost and simple preparation method.