Hydrothermally synthesized MnCo2O4 nanoparticles for advanced energy storage applications

•The Hydrothermal reaction time affects the electrochemical performance of the MnCo2O4 electrode.•MnCo2O4 electrode shows the areal capacitance of 144 mF/cm2.•The MnCo2O4//AC asymmetric supercapacitor (ASC) shows an energy density of 4.1 μWh/cm2. We observed the impact of reaction time on the electrochemical performance of MnCo2O4 nanoparticles, specifically focusing on the overgrowth of nanoparticles over the nanostructure. We characterized the synthesized nanomaterial using XRD, SEM, and XPS techniques to analyze its crystal structure, surface microstructure, and chemical states, respectively. The electrode prepared via a 5-hour hydrothermal reaction exhibited an outstanding areal capacitance of 144 mF/cm2 at a current density of 1A/g. Furthermore, it demonstrated an areal energy density of 4.1 μWh/cm2 at a power density of 0.225 mW/cm2. We assembled an asymmetric supercapacitor (ASC) configuration, MCO-5 h//AC, using MCO-5 h and activated carbon (AC), which showcased exceptional areal capacitance, areal energy density, and power density. These characteristics make it highly suitable for practical applications in energy storage. Overall, our findings highlight MCO-5 h as a promising electrode for energy storage applications.