Enhanced supercapacitor dynamics mediated by systematic incorporation of rGO in Mn3O4 matrix

The escalating need for effective energy storage systems, driven by the pursuit of sustainable and clean energy sources, has prompted a focused exploration in this study. This research centers on the utilization of Mn3O4 nanostructures to create composites with varying wt% (3 %, 6 %, and 9 %) of reduced graphene oxide (rGO) as electrode materials for supercapacitors, aiming to address the rising demands for energy. To achieve this a costeffective sol-gel auto-combustion method was employed to synthesize Mn3O4 and subsequently, Mn3O4/rGO composites were prepared using the solvothermal method. X-ray diffraction results confirmed the tetragonal structure of Mn3O4. Morphological features, observed through field emission scanning electron microscopy, revealed highly porous surfaces with small grain sizes, directly influenced by increasing rGO contents. Moreover, an energy-dispersive X-ray confirmed that no impurity was present in the synthesized composition. A detailed electrochemical study demonstrated distinctive redox peaks in cyclic voltammetry curves, signifying pseudocapacitive behaviour. At the same time, the galvanostatic charge-discharge test depicted the improved specific capacitance and discharging time with increased rGO concentration. Power and energy densities highlighted the enhanced performance of MO-3 among all samples. Likewise, electrochemical impedance spectroscopy validated the reduced resistance with rGO incorporation. In conclusion, MO-3 showed superior performance with (P = 0.47 kW/kg), (Cs = 427 F/g), and (E = 34.3 W h/kg) at 5 mA.