Nanostructured carbon electrodes for energy storage

Abstract

Current work on using nanostructured carbon surfaces in supercapacitors and batteries to enable enhanced performance is discussed. The emphasis is on solid electrolyte based batteries and supercapacitors which can be flexible and change form factor. This is a new concept for energy storage systems driven by the requirements of next generation mobile communication devices which will be designed to supplement regular battery power with power from harvested energy. It will be shown that a new class of flexible suprecapacitors and batteries can be realised through use of carbon electrodes with enhanced nanostructure. In particular Carbon nanohons (CNH) are considered. CNHs are formed in 'crushed' or 'origami -like' graphene sheets. They form into 10 -50 nm diameter particles with a high degree of open pores having high surface area and permeability. The variable spacing between 5nm -lnm of two graphene sheets in CNH introduces a new surface energy regime for intercollation of ions. Results from applying CNH in electrodes in supercapacitors and batteries are presented. The power density of a flexible supercapacitor, for example, can be increased very significantly by designing nanostructure into the carbon electrodes. The devices under consideration are aimed at powering mobile electronic and autonomous sensing systems. However, the potential of scaling of the technology to larger energy storage systems is viable.