▎ 摘　　要

NOVELTY - Silicon anode material of lithium ion battery comprises silicon-based cathode active material, graphite anode composite active material, composite conductive agent and composite binder. The graphite cathode composite active material includes primary particles and secondary particles, where the median diameter D50 of the primary particles is 3-6 mu m, the median diameter D50 of the secondary particles is 8-20 mu m, the mass of the graphite cathode composite active material is 100%, the mass fraction of the primary particles is 10-25% and the mass fraction of the secondary particles is 75-90%. USE - Used as silicon anode material of lithium ion battery. ADVANTAGE - The battery improves compaction through the blending of synthetic graphite particles, energy density of the battery, conductivity of the material and cycle performance of the battery; and reduces the electrical performance degradation caused by the large expansion of the material. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for (1) preparing silicon anode material of lithium ion battery comprising (i) dissolving binder A and stir once to obtain a glue solution, adding the conductive agent A and the conductive agent B into the glue solution and stirring for the second time to obtain a conductive glue solution, and (ii) mixing silicon-based cathode active material and the graphite cathode composite active material, adding the conductive glue in three times, and then adding the binder B, stirring to obtain slurry and then filtering and demagnetizing; (2) cathode pole piece of lithium ion battery comprising silicon cathode material of lithium ion battery; and (3) lithium ion battery comprising the cathode pole piece of lithium ion battery.