Porous silicon/carbon composite material, and preparation method and application thereof

The invention relates to a porous silicon/carbon composite material, and a preparation method and an application thereof, and belongs to the technical field of lithium ion battery. The composite material comprises the specific components by mass percentage: 0-80% of carbon, and 20-100% of silicon; the pore size of porous silicon is 0.01 nm-10 [mu]m, and the particle size of the porous silicon/carbon composite material is 10 nm-50 [mu]m. Rice hulls are used as raw material, the silicon/carbon composite material having a porous structure is obtained by adopting a metal thermal reduction and purification method. The composite material can be directly used as a negative electrode material of the lithium ion battery, and can also be mixed with other negative electrode materials to be used as a negative electrode material. Compared with non-porous silicon negative electrode materials, the material has greatly improved cycle stability. The biological substance which is rich in sources, low in price and easy to obtain is used as the raw material, the cost is low, and the preparation method is simple.