Synthesis, properties, and performance of nanostructured metal oxides for supercapacitors

Beyond activated carbon and other forms of high-surface area carbon operating solely as double layer storage materials in capacitors of high capacitance commonly somewhat imprecisely called supercapacitors other electrode materials storing electric charge by reversible and fast superficial redox processes are studied as active masses. The resulting devices combining double layer and Faradaic process-based charge storage - commonly called hybrid ones - show significantly higher capacitances at only marginally diminished power capability. Among the suggested materials metal oxides feature most prominently. Their formation, characterization and properties together with the performance of prepared devices are reviewed here.