Carbon-coated silicon phosphide carbon composite material as well as preparation method and application thereof

The invention relates to a carbon-coated silicon phosphide carbon composite material and a preparation method and application thereof.The preparation method of the composite material comprises the following steps that S1, phosphorus powder and silicon powder serve as raw materials, iodine serves as a transport agent, the raw materials and the transport agent are added into a reaction container together, a high-temperature reaction is conducted after vacuum sealing is conducted, cooling is conducted to the room temperature after the reaction is finished, and strip-shaped silicon phosphide crystals are obtained; s2, mixing the silicon phosphide crystals, a carbon material and an organic carbon source, and performing ball milling treatment to obtain an organic carbon source coated silicon phosphide carbon composite material; s3, putting the silicon phosphide carbon composite material coated with the organic carbon source into a quartz boat of a single-temperature-zone tubular furnace, performing high-temperature