▎ 摘　　要

NOVELTY - A composite graphite sheet preparing method involves mixing carbon microsphere, spherical natural graphite, artificial graphite powder, and grinding to obtain mixture. The mixture is heated and kneaded with modified asphalt. The powder is subjected to cold isostatic pressing. The molding body is carbonized and cooled, followed by carrying out impregnation treatment by using modified asphalt, performing carbonization treatment in tunnel kiln and cooling. The graphite-based embryo body is subjected to mechanical section pretreatment. The graphene oxide is mechanically coated on a graphene base. USE - Method for preparing a composite graphite sheet that is utilized in a lithium battery. ADVANTAGE - The method enables preparing the composite graphite sheet with high energy density and better stability of product quality. DETAILED DESCRIPTION - A composite graphite sheet preparing method involves mixing 30-40 pts. wt. carbon microsphere, 20-30 pts. wt. spherical natural graphite and 30-50 pts. wt. artificial graphite powder, and grinding to obtain mixture. The mixture is heated and kneaded with 20-30 pts. wt. modified asphalt for 1-2 hours and secondary ground to obtain secondary powder. The powder is subjected to cold isostatic pressing at normal temperature such that the total pressure is 10000 tons and the pressure is 50-200Mpa to obtain a molding body. The molding body is carbonized at 1200-1300 degrees C for 258-368- hours under protection of inert gas and cooled to room temperature, followed by carrying out impregnation treatment by using the modified asphalt at 180-230 degrees C with pressure of 0.5-3 MPa, performing secondary carbonization treatment in a tunnel kiln and cooling to room temperature to obtain product. The product is placed in an induction graphite furnace under the protection of inert gas at 2800-3200 degrees C for high temperature graphite processing to obtain a graphite-based embryo body. The graphite-based embryo body is subjected to mechanical section pretreatment to obtain graphene oxide. The graphene oxide is mechanically coated on a graphene base to obtain finished product.