Exploring the synergistic potential of cerium and lanthanum oxides prepared via microwave assisted sol-gel for energy storage applications

Rare-earth metal oxides have gained significant attention as promising electrode materials for energy storage due to their exceptional electrochemical properties. In this study, a nanocomposite comprising cerium oxide (CeO₂) and lanthanum oxide (La₂O₃) was synthesized via a microwave-assisted sol-gel method, followed by post-annealing, tailored for supercapacitor applications. Structural and morphological analyses confirmed the successful formation of nanocomposites with beneficial characteristics. Further investigations into surface area and pore structure revealed that the incorporation of lanthanum oxide greatly enhanced the material’s electrochemical activity. Electrochemical evaluations revealed a specific capacitance of 1038 Fg⁻¹ at 1 Ag⁻¹ and 994 Fg⁻¹ at 1 mV s⁻¹, obtained from galvanostatic charge-discharge and cyclic voltammetry, respectively. These results demonstrate superior electrochemical performance compared to pristine CeO₂, highlighting the enhanced charge storage capability and excellent rate performance of the CeO₂-La₂O₃ composite. An asymmetric all-solid-state supercapacitor, utilizing the CeO₂-La₂O₃ composite as the positive electrode and activated carbon as the negative electrode, achieved an energy density of 18 Whkg⁻¹ and a power density of 1500 Wkg⁻¹. Additionally, the device showcased remarkable cyclic stability, retaining 98% of its capacitance over 10,000 cycles. These findings underscore the significance of lanthanum oxide in enhancing cerium-based systems, presenting promising opportunities for next-generation energy storage technologies.