▎ 摘　　要

NOVELTY - The method comprises: performing chemical vapor deposition of graphene on a transition metal hydroxide to form a three dimensional graphene foam, and dissolving the three dimensional graphene foam in precursors; mixing a reducing agent and distilled water to prepare a mixed solution; and immersing the three dimensional graphene foam in the mixed solution by chemical bath deposition. The transition metal hydroxide is nickel-cobalt hydroxide (NixCo1-x(OH)2), where x is 0.3-0.5. The stoichiometric ratio of nickel and cobalt is 1:1-1:2, preferably 1:2. USE - The method is useful for producing a three-dimensional graphene composite, which is useful in a supercapacitor (all claimed). ADVANTAGE - The produced three-dimensional graphene composite improves power outage capability, conductivity and energy density of the supercapacitor. DETAILED DESCRIPTION - The method comprises: performing chemical vapor deposition of graphene on a transition metal hydroxide to form a three dimensional graphene foam, and dissolving the three dimensional graphene foam in precursors; mixing a reducing agent and distilled water to prepare a mixed solution; and immersing the three dimensional graphene foam in the mixed solution by chemical bath deposition. The transition metal hydroxide is nickel-cobalt hydroxide (NixCo1-x(OH)2), where x is 0.3-0.5. The stoichiometric ratio of nickel and cobalt is 1:1-1:2, preferably 1:2. The method further comprises: heat-treating the precursors and the three dimensional graphene foam at a temperature of 800-1500 degrees C; dipping the treated mixture in a methacrylic resin solution; and dissolving the mixture in iron(III) chloride/hydrochloric acid solution. The precursors have an average pore diameter of 100-200 mu m. The immersing step is accomplished at a temperature of 90-140 degrees C for 2-6 hours. INDEPENDENT CLAIMS are included for: (1) a three-dimensional graphene composite; and (2) a supercapacitor.