Supercapatteries with Hybrids of Redox Active Polymers and Nanostructured Carbons

This chapter considers the development and role of supercapatteries as practical energy storage devices for commercial development. Current battery technology can produce a high power density, making them ideal for performance applications; however suffer from poor specific power. Supercapacitors on the other hand can have a specific power, several times that of batteries but lack their superior energy density making them more suited to larger scale energy storage. Supercapatteries aim to bridge the void created between these energy storage devices by the use of an asymmetric cell design utilizing both double layer capacitance of supercapacitors and pseudocapacitance of batteries. A background into the theory behind these different mechanisms and how they contribute to the ability to store an electrical charge will be explained. Discussion on the recent scientific developments in interfacial chemistry of electrode materials, which contribute to the overall performance of such devices, is also present. In particular, carbon allotropes (such as nanotubes), both redox active and conductive polymers and hybrid materials are explored for their role in the future of these energy storage devices. Choice of electrolyte and separator material is also crucial for an optimized cell design and similarly, cell fabrication techniques and orientation contribute significantly to performance, all of which are reviewed herein. Environmental considerations are also presented, where novel reprocessing processes have been developed for the recovery of carbon electrodes after hybridization. Recent advances and current data on the above topics are provided from both within this research group and the wider electrochemistry field. It is anticipated that with further research and development, supercapatteries promise a new type of electrochemical energy storage technology combining the merits of both rechargeable batteries and supercapacitors.