Electrode materials for EDLC and pseudocapacitors

In the emerging arena of renewable energy technologies, one of the highly faced challenges is the development of efficient and sustainable energy storage devices. Supercapacitor being one such potential device, widely used to tap the gap between energy and power densities of batteries and capacitors. Supercapacitors with their forefront characteristics like minimum maintenance requirement, relative energy storage along with moderate cycle life, possess high power density making them a superior storage device till date. Based on energy storage mechanisms, they are classified into two categories namely electrochemical double-layer capacitors (EDLCs) and pseudocapacitors (PCs), which are non-Faradaic and Faradaic with redox mechanisms, respectively. Hence, different electrode materials are required for different storage mechanisms. Nevertheless, performance of supercapacitor also relies on factors such as electrolyte and voltage range of electrochemical system. Materials used for EDLCs typically possess high surface area, whereas PC materials rely on charge transfer mechanism. In this chapter, we are focusing to provide an insight into different electrode materials such as carbon-based materials, conducting polymers, and metal oxide used in supercapacitors.