Abstract:
Disclosed herein is an electrode for energy devices such as electric double layer capacitors, which includes conductive fibers made of carbon, such as carbon nanotubes, as an electrode active material and has a high capacitance. The electrode for energy devices includes a current collector and a plurality of conductive fibers (e.g., carbon nanotubes) provided to stand on a surface of the current collector so that their one ends are electrically connected to the surface of the current collector, wherein the conductive fibers are made of carbon and have carboxyl group-containing functional groups or oxo group-containing functional groups and hydroxyl group-containing functional groups attached thereto. The conductive fibers preferably carry a quinone group-containing compound.