Microwave irradiation effect of La₂O₃-CeO₂ nanocomposites as a potential electrode material for asymmetric supercapacitor

Exploration and synthesis of nanomaterials have been crucial in recent years for the advancement of energy storage research, especially in the development of supercapacitors. Scientists have employed a variety of materials to improve energy and power density, such as metal oxides, rare earth metals, and composites. It is still difficult to balance energy density with cyclic stability, which is motivating further attempts to develop electrode materials. This work deals with a rare earth metal (La₂O₃-CeO₂) bimetallic nanocomposite that has been synthesized from the microwave irradiation method. In supercapacitor behaviour like cyclic voltammetry (CV), analysis results revealed a specific capacitance of 410 F/g at 5 mV/s. Likewise, the galvanostatic charge/discharge study described (La₂O₃, CeO₂) electrodes have less discharge time when compared to La₂O₃-CeO₂ electrodes, which have a prolonged discharge time and enhanced specific capacitance of 1005 F/g at 0.5 A/g. Furthermore, activated charcoal anode and cathode La₂O₃-CeO₂ are used to develop the asymmetric supercapacitor device in a 3 M KOH electrolytic medium. These results obtained a maximum energy density of around 39.65 Wh/kg and a maximum power density of 1200 W/kg. The asymmetric device exhibits cyclic stability of 82.13% even after a continuous 5000 charge–discharge cycle and its columbic efficiency is 102%. This work offers novel insights into the processing of rare-earth metal to prepare supercapacitor electrode materials for energy storage applications.