▎ 摘　　要

NOVELTY - A negative electrode graphene sheet preparing method involves utilizing graphene as a raw material, spray drying to obtain graphene powder, and carrying out low temperature drying treatment to graphite powder. The graphene powder is utilized as negative electrode active material, polished with the binder at mass ratio of 95:50 for 30-50 seconds. N-methyl-2-pyrrolidone is added and continue to grind to uniform viscosity to obtain slurry. The slurry is evenly coated on the copper foil, vacuum dried to remove the N-methyl-2-pyrrolidone in the electrode sheet followed by punching electrode sheet. USE - Method for preparing negative electrode graphene sheet that is utilized in supercapacitors (claimed). ADVANTAGE - The negative electrode graphene sheet has high rate cycling performance, under conditions of different charge-discharge rate conversion. DETAILED DESCRIPTION - A negative electrode graphene sheet preparing method involves utilizing graphene as a raw material, spray drying to obtain graphene powder, and carrying out low temperature drying treatment to graphite powder. The graphene powder is utilized as negative electrode active material, polished with the binder at mass ratio of 95:50 for 30-50 seconds. N-methyl-2-pyrrolidone is added and continue to grind to uniform viscosity to obtain slurry. The slurry is evenly coated on the copper foil, vacuum dried to remove the N-methyl-2-pyrrolidone in the electrode sheet followed by punching electrode sheet into diameter of 16 mm original film, where the element type of the graphene is 97.78 wt.% carbon, 0.96 wt.% nitrogen and 1.26 wt.% oxygen positively correlated with the conductivity of the carbon-oxygen ratio of 77.6 mass, graphene sheets particle size is 238 nm and the sheet thickness is 1.87 nm. An INDEPENDENT CLAIM is also included for a negative electrode graphene sheet prepared by the method.