abstract |
A conductive material includes a graphene-nanonsheet material, with charge-storage material in voids in and/or coating the graphene material. The charge-storage material may include any of a variety of types of carbon, including carbon black, acetylene black, furnace black, carbon fibers, carbon nanotubes, graphene in the form of wrinkled sheets of graphene, carbon nano-onions, or hydrothermal-synthesized nanospheres of carbon material. Alternatively, the charge-storage material may be non-carbon pseudocapacitive materials. Also, the charge-storage material may involve Faradaic processes similar to those observed with battery electrodes. The conductive material may be formed or placed on a conductive or a dielectric substrate. One or more gaps may be formed in the conductive material, with the conductive material forming two or more electrodes. The electrodes may then be covered with an electrolyte material, to produce an electric double layer capacitor. |