▎ 摘　　要

NOVELTY - Carbon-silicon-tin composite cathode material comprises a carbon material particle substrate and a coating layer. The coating layer comprises a coating inner layer and a coating outer layer. The coating inner layer is mixture of silicon-tin composite material and amorphous carbon. The silicon-tin composite material is a honeycomb silicon-based material with nano-tin material deposited on the surface and in the pores. The amorphous carbon is coated on the surface of the silicon-tin composite material and is filled in the gap between the carbon material particle substrate and the silicon-tin composite material. The coating outer layer is a carbon coating layer. USE - Used as a carbon-silicon-tin composite cathode material. ADVANTAGE - The composite cathode material improves the conductivity and capacity, effectively buffers the volume expansion of the cathode material, and improves the cycle performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing carbon-silicon-tin composite cathode material comprising (i) soaking the silicon-based material in the mass concentration of 5-50% of hydrofluoric acid solution, where the mass ratio of the silicon-based material and the hydrofluoric acid solution is 1:5-30; stirring for 0.5-3 hours at room temperature, filtering, washing the filter cake by distilled water to neutral, drying at 40-100 degrees C, obtaining the honeycomb silicon-based material; where the silicon-based material is at least one of silicon oxide and nano-silicon oxide; the grain diameter D50 of the nano-silicon is 50-500 nm; the grain diameter D50 of the silicon oxide is 0.5-5 mu m; (ii) uniformly mixing the tin salt and water according to mass ratio of 1:10-100, slowly dripping 0.01 mol/l of hydrochloric acid to clear under stirring; where the tin salt is at least one of stannous chloride and tin chloride; (iii) adding the honeycomb silicon-based material obtained in the step (i) into the solution prepared in the step (ii), completely immersing, stirring for 0.5-3 hours; slowly dripping aqueous ammonia solution with mass concentration of 10-50%, the pH of the solution is 4-10, continuously stirring for 0.5-5 hours; (iv) filtering, washing the filter cake to neutral, drying at 50-100 degrees C to obtain silicon-tin composite material precursor; (v) preparing 300 pts. wt. high molecular binder solution with mass concentration of 0.01-2%: adding 1-20 pts. wt. silicon-tin composite material precursor obtained in step (iv), 70-99 pts. wt. carbon material particle substrate, and 1-20 pts. wt. organic carbon source into the polymer binder solution, and stirring 0.5-5 hours, spray-drying to obtain the black powder; where the particle size D50 of the carbon material particle substrate is 1-40 mu m; the air inlet temperature of the spray drying is 100-250 degrees C; and (vi) uniformly mixing the obtained black powder with the carbon source of 1-20 pts. wt. in a high speed mixer, treating in the inert atmosphere at 500-1100 degrees C for 2-24 hours, where the inert atmosphere is nitrogen, argon or helium gas atmosphere. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the carbon-silicon-tin composite cathode material.