Lamno3-Mn3o4 Nanocomposite: Synergetic Effect Towards High Electrochemical Performance

Metal oxides have been a focus of research for energy storage devices. Herein, xLaMnO3 – (100-x) Mn3O4 (LMO-MO) composites (xWt%: 100, 90, 70, and 50) were prepared via one-pot synthesis to elucidate the synergistic effect of the composite constituents on composite’s electrochemical performance. The X-ray diffraction analysis confirmed the presence of individual compounds in the desired ratio and phase. The X-ray photoelectron spectroscopy confirmed the presence of Mn2+ and Mn3+ oxidation states, indicating the presence of both LaMnO3 (LMO) and Mn3O4 (MO) in the composite. The electrochemical performance of composite electrodes prepared using nickel foam was assessed in 1 and 6M KOH solutions. High specific capacitance measured via cyclic voltammetry of ~ 584 Fg-1 at a scan rate of 1 mVs-1 was recorded for the composite of LMO-MO (70%: 30%) in 6M KOH. At the same time, charge-discharge curves revealed a maximum specific capacitance of around 405 Fg-1 for an x =70% sample at a current density of 0.5 Ag-1. The EIS studies show a reduction in the internal resistance of the composite due to the interconnected structure and reversible faradic process at the interface with a high degree of Coulombic efficiency. A higher overall electrochemical performance of the electrode was recorded in a 6M KOH electrolyte. The enhanced electrochemical performance of the composite is attributed to efficient charge transfer kinetics through the electrode-electrolyte interface via easy electron hopping pathways between LMO and MO in the composite. These findings suggest that the studied LMO-MO composites could be a potential material for pseudocapacitor energy devices.