▎ 摘　　要

NOVELTY - Energy device comprises a porous metal substrate; graphene layer deposited onto a surface of the porous metal substrate; carbon nanotubes grown onto a surface of the graphene layer; and metal oxide nanostructures deposited onto a surface of the carbon nanotubes and the surface of the graphene layer. USE - The energy device is useful in supercapacitor application. ADVANTAGE - When used in a supercapacitor application, the hybrid foam can demonstrate increased gravimetric capacitance and area capacitance. The hybrid foam can provide an increased surface area for the loading of the ruthenium dioxide (RuO2) nanoparticles and can facilitate electrolyte infiltration. For example, the hybrid foam can allow an electrolyte to access active materials. The carbon nanotubes can act as a conductive framework such that the seamless connections at the interface between the graphene layer and the carbon nanotubes can increase the conductivity and charge transport. Increased electrolyte access, increased conductivity, and increased charge transport can provide a high active material utilization, decreased internal resistance, increased rate handleability, and increased cycling stability. The supercapacitors based on the hybrid foam can increase specific capacitance and extend the operational voltage window. The supercapacitors based on the hybrid foam can increase a maximum energy density and a power density. Further, supercapacitors based on the hybrid foam can show an increase in cycling stability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a supercapacitor comprising a first electrode including a first porous metal substrate, graphene layer deposited onto a surface of the first porous metal substrate, carbon nanotubes grown onto a surface of the graphene layer, and metal oxide nanostructures deposited onto a surface of the carbon nanotubes and the surface of the graphene layer; a second electrode, including a second porous metal substrate, graphene layer deposited onto a surface of the second porous metal substrate, carbon nanotubes grown onto a surface of the graphene layer, and metal oxide nanostructures deposited onto a surface of the carbon nanotubes and the surface of the graphene layer; an electrolyte; and a separator positioned between the first electrode and the second electrode; and (2) a method which involves growing graphene layer onto a surface of a porous metal substrate using chemical vapor deposition; growing carbon nanotubes onto a surface of the graphene layer using chemical vapor deposition to form a coated porous metal substrate; and depositing metal oxide nanostructures onto a surface of the coated porous metal substrate to form a hybrid foam.