Unveiling the synergistic potential of LaMnO3–CeO2 composites in supercapacitor applications

Abstract

This study investigates the synthesis of LaMnO₃–CeO₂ composites with varying CeO₂ contents ((100 − x)% LaMnO₃–x% CeO₂; x = 0, 10, 30, 50, 100 wt%) via an autocombustion method to elucidate their synergistic electrochemical properties. X-ray diffraction (XRD) confirmed the presence of both LaMnO₃ (LMO) and CeO₂ phases in the anticipated stoichiometric ratios. Nitrogen adsorption–desorption isotherms revealed a mesoporous structure, with the LMO–CeO₂ (70 : 30) composite exhibiting the highest specific surface area of 14.32 m² g⁻¹, as determined by the Brunauer–Emmett–Teller (BET) method. X-ray photoelectron spectroscopy (XPS) provided insights into the ion valences and chemical composition of the composites. Electrochemical performance was evaluated in a 1 M KOH aqueous electrolyte using a three-electrode configuration. The LMO–CeO₂ (70 : 30) composite demonstrated superior performance, achieving a specific capacitance of 830.3 F g⁻¹ at a scan rate of 1 mV s⁻¹ and 637.6 F g⁻¹ at a current density of 1 A g⁻¹, corresponding to an energy density of 31.9 Wh kg⁻¹ at a power density of 357.5 W kg⁻¹. These results underscore the synergistic enhancement of electrochemical properties through the integration of LaMnO₃ and CeO₂, offering significant potential for the development of high-performance materials for energy storage applications.