Review on Transition Metal Oxides and Their Composites for Energy Storage Application

Supercapacitors evolved as a breakthrough to the existing shortages in energy resources because of its enhanced capacitive performance, long-term stability, and high power density. Transition metal oxides (TMOs), a redox active material in energy storage applications, showing high specific capacitance (100–2000 F/g) than the electrical double-layer capacitor (EDLC) material has been reviewed a lot. Among various TMOs, nickel oxide (NiO), tin oxide (SnO2), manganese dioxide (MnO2), tungsten oxide (WO3), vanadium pentoxide (V2O5) are widely used by researchers due to their high theoretical capacitance, low cost, and long cycle life. The limitations of TMO-based electrode material includes low electrical conductivity, ion mobility, and low energy density. It is thus important to develop proper combination of TMO with other transition metals, TMOs, transition metal dichalcogenides (TMDs), conducting polymers (CPs) and carbon-based materials (graphene oxide (GO), activated carbon (AC) and reduced GO (rGO)). This chapter focuses on ongoing development in six TMO-based electrode material (NiO, ZnO, MnO2, SnO2, WO3, V2O5) fabrication for the enhancement of electrochemical performance, their synthesis method and then review about the recent progress in studying the supercapacitor performance of the material. The limitations of each TMOs listed separately, providing new insights for future energy storage applications.