Supercapacitive composite metal oxide electrodes formed with carbon, metal oxides and conducting polymers

Supercapacitors have garnered much attention as energy storage devices. In this article review of most popularly studied metal oxide electrode materials are reviewed with the recent developments. The metal oxides in pristine form have not been able to achieve performance characteristics required for practical applications therefore, composite electrode are also studied. The composite electrode works mainly on the synergistic properties of two or more materials which complement each other and consequently perform better than one electrode. Carbon and carbon derivatives are the most popular option for the composite electrodes. The nanostructuring of the electrode materials has a positive effect on the electrode performance. Understanding of charge storage mechanism is important and needs to be considered while working on nanoscale. The review focuses on the charge storage mechanism, composite electrodes and nanostructuring of the electrodes which ultimately result in better supercapacitive performance. (C) 2016 Elsevier B.V. All rights reserved.