▎ 摘　　要

NOVELTY - Preparation of negative electrode material involves (s1) mixing carbon source gas, nitrogen source gas and silicon source gas under normal temperature and protective atmosphere to obtain a mixed gas, (s2) introducing the mixed gas into a pre-heated deposition furnace optionally provided with a nanocarbon substrate, performing thermal deposition at 400-550℃ for 6-10 hours, and (s3) grading obtained product, carrying out carbon coating treatment, and post-processing. The mixed gas contains 10-30 vol.% carbon source gas, 15-40 vol.% nitrogen source gas and 50-75 vol.% silicon source gas. USE - Preparation of negative electrode material (claimed) for secondary battery. ADVANTAGE - The method enables preparation of negative electrode material with high capacity, first effect and conductivity, excellent rate performance and long cycle characteristics. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the negative electrode material, which comprises a nucleation center, an intermediate layer covered on the outer surface of the nucleation center, and an outermost carbon layer. The composition of the intermediate layer comprises silicon nitride (SiNx, where x is more than 0.01 to 1.5) and silicon carbide. The nucleation center is carbon substrate and/or silicon nanoparticles.