CAPACITORS | Electrochemical Hybrid Capacitors

‘Asymmetric’ supercapacitors consist of two electrodes that differ considerably in capacitance. Hybrids of electrolytic and electrochemical capacitors have both a metal oxide electrode and a counterelectrode of aluminum or tantalum covered with a dielectric film. Such a device can operate at many hundreds of volts. The decomposition voltage of the electrolyte is no longer the limiting factor, because almost all of the cell voltage drops across the anode film. This article outlines (1) asymmetric devices – battery-type capacitors, modified carbon electrodes and (2) hybrid electrolytic capacitors.