▎ 摘　　要

NOVELTY - A hierarchical composite structure comprises an open-cell graphene foam or graphene-like foam coated with a conductive nanoporous spongy structure and 10 (v/v)% of hollow of the pores of the graphene foam or graphene-like foam is filled with the conductive nanoporous spongy structure. USE - Hierarchical composite structure used as electrode and in electrochemical-energy-storage device e.g. super capacitor (all claimed). Can also be used in hybrid and electric vehicles or portable electronics. ADVANTAGE - The hierarchical composite structure has high conductivity, porosity, lightness, large specific surface area, high specific and volumetric capacitance and exhibits excellent interfacial properties, flexibility and cycling stability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of hierarchical composite structure, which involves providing a graphene foam or graphene-like foam having an open-cell structure, immersing the graphene foam or graphene-like foam in a electrolyte solution, comprising conductive material or their precursor thereof, removing the air trapped in the graphene foam or graphene-like foam immersed in the electrolyte solution, electrodepositing the conductive material, or the conductive material formed from the their precursor, on the graphene foam or graphene-like foam in the electrolyte solution, so as a conductive nanoporous spongy structure is formed coating the graphene foam or graphene-like foam and partially filling the hollow of the pores of the graphene foam or graphene-like foam; (2) electrode, which comprises hierarchical composite structure; and (3) electrochemical-energy-storage device, which comprises electrode (a), separated from electrode (b) by a separator and immersed in an electrolyte.