Synergetic effect towards high electrochemical performance in LaMnO3–Co3O4 composites

Abstract

Electrochemical energy storage devices, especially supercapacitors, require electrode materials with high specific capacitance, excellent stability, and efficient charge transfer kinetics. This study presents LaMnO₃(LMO)–Co₃O₄ composites as advanced electrode materials designed to enhance specific capacitance for electrochemical applications. The xLMO–(100% − x) Co₃O₄ composites (with wt% x values of 100%, 90%, 70%, 50%, and 0%) were synthesized using an auto-combustion method followed by calcination at 900 °C. X-ray diffraction analysis confirmed the presence of the individual compounds in the intended ratios. N₂ adsorption/desorption measurements revealed that the LMO–Co₃O₄ composites have a mesoporous structure with a high surface area, with the LMO–Co₃O₄ (70%:30%) composites achieving the highest specific surface area of 6.78 m² g⁻¹. The electrochemical performance of these composites was evaluated using cyclic voltammetry, charge–discharge, and electrochemical impedance spectroscopy in a three-electrode system with a 1 M KOH electrolyte. The battery-type LMO–Co₃O₄ (70%:30%) composites exhibited outstanding electrochemical performance, showing a specific capacitance of 1614 F g⁻¹ at a scan rate of 1 mV s⁻¹ and 660 F g⁻¹ at a current density of 0.5 A g⁻¹, along with energy and power densities of 33 W h kg⁻¹ and 203 W kg⁻¹, respectively. This hybridization approach leverages the strengths of each material to enhance overall electrochemical performance.