Book excerpt: New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. Supercapacitors have been widely acknowledged to be promising devices for energy storage. This book describes the latest progress in the discovery and development of nanoelectrolytes and nanoelectrodes for supercapacitor applications.