▎ 摘　　要

NOVELTY - Preparing porous silicon/aluminum oxide/amorphous carbon composite material comprises: (1) uniformly dispersing aluminum-silicon (Al-Si) alloy in the diluted acid solution under the action of stirring, performing incomplete etching reaction by controlling the reaction time; realizing not completely removing aluminum, then filtering, cleaning, and vacuum drying to obtain the porous silicon powder containing aluminum; (2) paving the porous silicon containing aluminum on the bottom of the porcelain boat, placing in a tubular furnace, heating to the reaction temperature in the protective gas atmosphere, then closing the protective gas, introducing carbon dioxide gas, converting aluminum of aluminum-containing porous silicon to aluminum oxide, after finishing the reaction, closing carbon dioxide gas, introducing protective gas, and cooling to room temperature. USE - The method is useful for preparing porous silicon/aluminum oxide/amorphous carbon composite material, which is used in lithium-ion battery cathode material (claimed). ADVANTAGE - The produced aluminum oxide has high hardness, high mechanical strength and good chemical stability, so it can stabilize and reinforce the three-dimensional micro/nano grading structure characteristic of porous silicon, improve the circulation stability of the porous silicon in the charging process, and the coated carbon layer on the surface can greatly improve the conductivity of the composite material, which greatly improves the electrochemical performance of the porous silicon. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: porous silicon/aluminum oxide/amorphous carbon composite material, prepared by using aluminum-containing porous silicon as the raw material, carbon dioxide as the oxidant and carbon source, using carbon dioxide to oxidize aluminum in porous silicon to convert it into aluminum oxide under high temperature conditions, at the same time, carbon dioxide itself is reduced to amorphous carbon coated on the surface of porous silicon; lithium of the ion battery electrode, comprising an active material, a conductive agent and agglomerant, where the active material is the porous silicon/aluminum oxide/amorphous carbon composite material; and lithium ion battery, comprising lithium ion battery cathode.