▎ 摘　　要

NOVELTY - Porous silicon-carbon composite material that reduces carbon emission having a core-shell structure, comprises porous silicon composite carbon, porous silicon composite graphene or porous silicon composite carbon gel, which are respectively denoted as: carbon-encapsulated R-silicon dioxide, graphene-wrapped R-silicon dioxide, and carbon gel-encapsulated R-silicon dioxide. USE - The material is useful in preparing lithium batteries (claimed). ADVANTAGE - The material provides the space required for the volume expansion of silicon, alleviates the volume effect of silicon and significantly improves the electrical properties of the material. DETAILED DESCRIPTION - Porous silicon-carbon composite material that reduces carbon emission having a core-shell structure, comprises porous silicon composite carbon, porous silicon composite graphene or porous silicon composite carbon gel, which are respectively denoted as: carbon-encapsulated R-silicon dioxide (R-SiO2-C), graphene-wrapped R-silicon dioxide (R-SiO2-G), and carbon gel-encapsulated R-silicon dioxide (R-SiO2-CN). An INDEPENDENT CLAIM is also included for preparing the composite material, comprising (i) mixing and dissolving the nonionic surfactant and the cationic surfactant in hydrogen chloride solution according to the molar ratio of 1:(1-2), stirring until the solution is clear, adding sodium metasilicate solution while stirring, where the molar ratio of sodium metasilicate, cationic surfactant, nonionic surfactant, hydrogen chloride, and waster is 1:(0.1-0.15):(0.05-0.08):(12-15):(250-280), stirring for 0.5-1.5 hours, allowing to stand at room temperature for 8-12 hours, and separating and drying the precipitate, heating to 500-580degrees Celsius at a rate of 1-3degrees Celsius/minute in the air, and placing for 3-8 hours to obtain silicon dioxide ball, mixing and grinding the silicon oxide ball and magnesium powder according to a mass ratio of 1:1, and heating to 600-700degrees Celsius at a rate of 1-3degrees Celsius/minute under argon atmosphere containing 5% hydrogen, soaking the calcined product in hydrochloric acid solution for 8-12 hours, etching the dyeing finger with 8-12 wt.% hydrofluoric acid solution for 8-15 minutes, cleaning and drying to obtain R-silicon dioxide, and (ii) preparing carbon, graphene or carbon gel-encapsulated R-silicon dioxide.