▎ 摘　　要

NOVELTY - Cathode material comprises a silicon-based material, where the particles of the silicon-based material have at least one concave part with width of 50 nm to 20 mu m, and depth of 50 nm to 10 mu m. The cathode material further comprises graphite and a conductive agent, where at least part of the graphite is located in the concave part of the silicon-based material, and the average width of the concave portion is a, the average particle size D50 of graphite is b, and the average minimum particle width of graphite is c, and c not less than a, b not less than 3a. The silicon-based material includes at least one of silicon, silicon oxide, silicon carbon or silicon-oxy-carbon ceramic material (SiOC). The conductive agent comprises conductive carbon black, Ketjen black, acetylene black, carbon nanotubes or graphene. USE - The cathode material is useful for cathode pole piece in electrochemical device of electronic device (all claimed). ADVANTAGE - The cathode material overcomes the problem of low compaction density of the silicon-based cathode material having the concave structure, and overcomes the defect of low volume energy density of the concave structure; having silicon-based material particles with recesses improves the volume expansion of the silicon-based material, enhances the interface contact between different materials, thus improving the interface conductivity; and is utilized as next generation high specific capacity cathode material, which can improve the energy density of the electrode assembly; and promotes electrolyte diffusion and penetration, improves the liquid holding capacity of the cathode pole piece, reduces the transmission impedance, so as to improve the multiplying power performance and cycle performance of the corresponding electrochemical device.