Electrochemical behaviour of microwave-assisted synthesized cerium oxide annealed at different temperatures

In the recent past, the electrode materials with high capacitance and excellent cycle stability have attracted the global scientific community for the development of novel advanced supercapacitors. In that context, rare earth metal oxides like Cerium Oxide (CeO 2 ) have emerged as potential electrode material due to its characteristics such as prominent valency states, eco-friendly nature, abundance, and outstanding redox properties. The current study reports about the CeO 2 nanomaterial that is synthesized by microwave-assisted method followed by post-annealing at different temperatures and thereby examined for supercapacitor applications. The crystallographic and morphological study confirms the formation of CeO 2 nanoparticles and porous nature of the prepared materials. As annealing temperature was increased, the properties of CeO 2 changed and demonstrated different performance. The maximum specific capacitance of 656 Fg −1 at 2 Ag −1 was observed for the sample annealed at 500 °C. The asymmetric supercapacitor fabricated CeO 2 //AC exhibited an energy density of 18 Wh kg −1 at a power density of 833 W kg −1 along with excellent rate capability. Further cyclic stability test conducted for 3000 cycles exhibited a capacitance retention of 93% which demonstrated the superior stability of the material. The observed electrochemical results demonstrated the potential of CeO 2 that paves way for the further involvement of these in the energy storage field.