Preparation method and application of silicon-carbon-based composite material

The invention belongs to the technical field of new energy materials, and particularly relates to a preparation method and application of a silicon-carbon-based composite material. A simple method is used for preparing the silicon-carbon-based composite material, ammonium bicarbonate, a carbon source and a silicon metal compound are mixed and heated and subjected to heat preservation in an inert atmosphere furnace for a certain time, and then high-temperature pyrolysis is conducted to carbonize the mixture; and taking out, carrying out acid pickling, precipitation and water washing, removing redundant solvent, and drying to obtain a carbon-coated silicon composite material, namely the silicon-carbon-based composite material. Wherein the particle size of the used silicon metal compound is 0.05-50 [mu] m, and the prepared material is excellent in stability. According to the material, silicon particles are uniformly coated with a carbon layer, so that huge volume change of silicon during lithium ion intercalatio