▎ 摘　　要

NOVELTY - Preparation of surface graphene coated high-capacity spherical hard carbon anode material, involves mixing asphalt or resin with crosslinking agent under acidic additive, and carrying out polymerization reaction to obtain a polymerization reactant, ball milling and crushing to obtain hard carbon precursor, (ii) placing hard carbon precursor into silicone oil and processing to obtain polymer microspheres, (iii) carrying out oxidative stabilization treatment, and pre-carbonization to obtain spherical hard carbon, (iv) adding into graphite oxide solution and drying. USE - Preparation of surface graphene-coated high-capacity spherical hard carbon anode material. ADVANTAGE - The spherical hard carbon anode material has uniform particle size distribution and high packing density. The surface of the spherical hard carbon is coated with graphene to form a conductive network with a core-shell structure, so that the transmission of ions and electrons is facilitated, and thus the conductivity of the anode material is improved. DETAILED DESCRIPTION - Preparation of surface graphene coated high-capacity spherical hard carbon anode material, involves (i) mixing asphalt or resin with crosslinking agent under acidic additive, and carrying out polymerization reaction at a temperature of 120-250 degrees C for 2-6 hours to obtain a polymerization reactant, subjecting the polymerization reactant to ball milling and crushing, obtaining hard carbon precursor with volume average particle size d50 of 10-15 microns through grading, where the mass ratio of asphalt or resin, crosslinking agent and acid additive is 100:10-100:1-20, the resin is coumarone resin and/or phenolic resin, the crosslinking agent is trioxymethylene, p-xylylene glycol, p-benzaldehyde and/or furfural, and the acidic additive is methanesulfonic acid or p-toluenesulfonic acid or naphthalenesulfonic acid or concentrated sulfuric acid, (ii) placing the hard carbon precursor into a silicone oil and processing into ball at 200-300 degrees C to obtain polymer microspheres, (iii) subjecting the obtained polymer microspheres into oxidative stabilization treatment in an air atmosphere at 230-280 degrees C for 0.5-4 hours, and then pre-carbonizing at 500-700 degrees C for 0.5-4 hours to obtain spherical hard carbon, (iv) adding spherical hard carbon into graphite oxide solution with concentration of 0.1-20 mg/mL, where the mass ratio of spherical hard carbon to the oxidized graphite of oxidized graphite solution is 100:1-60, then drying at 50-120 degrees C for 1-4 hours to remove solvent in the oxidized graphite solution, and obtaining spherical hard carbon powder coated with graphite oxide, and (v) protecting the spherical hard carbon powder coated with graphite oxide under an inert atmosphere, and performing heat treatment at 700-1200 degrees C for 1-6 hours and cooling to room temperature to obtain, graphene-coated spherical hard carbon anode material.