Preparation method of high-performance composite graphite negative electrode material

The invention discloses a preparation method of a high-performance composite graphite negative electrode material, which comprises the following steps: taking natural flake graphite fine powder as a raw material, bonding and granulating the graphite fine powder under the action of a modifier and mechanical force, graphitizing at high temperature, curing and molding, and crushing to obtain the composite graphite negative electrode material. The composite graphite negative electrode material has high energy density of natural graphite, and is high in isotropy due to the fact that the interiors of particles of the composite graphite negative electrode material are composed of a plurality of layered graphite units with different orientations; the layered graphite units are coated and connected by the hard carbon layers, so that intercalation and deintercalation channels of lithium ions are increased, the charge-discharge rate of the composite graphite negative electrode material is improved, the cycle performance