Benchmarking Electrode Materials for Supercapacitors, Pseudocapacitors, and Hybrid Capacitors

Electrochemical supercapacitors, due to their fast charge–discharge rates, long-term cyclic stability, and higher power density (PD), are considered promising and essential energy storage devices. Still, the energy density (ED) value of supercapacitors is lower than that of batteries, which limits its application in commercial usage. To achieve high ED electrodes without compromising their stability, the designing of electrode materials with proper electrolytes is important. The electrode materials with high cyclic stability, better electrical conductivity, effective ionic transportation at the electrode–electrolyte interface, and high chemical stability act as promising supercapacitor electrodes and show great potential in commercial usage. In the present chapter, we aim to discuss benchmarking electrode materials such as transition metal oxides, chalcogenides, nitrides, carbides, and phosphides for supercapacitors, pseudocapacitors (PSCs), and hybrid capacitors. Moreover, we have provided a summary of the electrochemical supercapacitor performance of these materials. Lastly, the discussion on the benefits, challenges, and future prospects of supercapacitors is mentioned.