Electrochemical Supercapacitors as Versatile Energy Stores

“Supercapacitors” are a new category of electrical condenser which are based on the properties of charge distribution at the interface of an electrode/electrolyte solution. After an introduction to the features of such devices, a brief history of their development is followed by a description of some technical details. The latter part of the paper is devoted to some specific properties of ruthenium and iridium oxides, RuO_x and IrO_x, which exhibit very interesting interfacial behaviour for their potential use in supercapacitors. In particular, these materials are very versatile in their method of preparation and in their surface properties. Prospects for changing the properties of the active layer of the superconductor by mixing two or more oxides are discussed.