Facile Hydrothermal Synthesis of MnCo₂O₄/N-doped RGO Composites as Cathode Materials for Zinc-Ion Batteries

The increasing demand for sustainable and efficient energy storage systems has accelerated the development of advanced electrode materials for rechargeable batteries. Among various energy storage technologies, zinc-ion batteries (ZIBs) have attracted considerable attention owing to their low cost, high safety, environmental friendliness, and the abundant availability of zinc resources. Nevertheless, the electrochemical performance of cathode materials remains a major challenge for their practical applications. In this study, manganese cobalt oxide (MnCo₂O₄) modified with nitrogen-doped reduced graphene oxide (NRGO) was successfully synthesized via a facile hydrothermal method to improve the electrochemical performance of ZIB cathodes. The synthesized composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), while their electrochemical properties were evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The MnCo₂O₄/NRGO composite exhibited a discharge specific capacity of approximately 157 mAh/g at a current density of 0.05 A/g and maintained stable electrochemical performance over 50 charge–discharge cycles. Compared with pristine MnCo₂O₄, the composite delivered enhanced charge storage capability, prolonged charge–discharge duration, and improved current stability, which were attributed to the excellent electrical conductivity and efficient charge-transfer pathways provided by the NRGO conductive network. These findings demonstrate that the MnCo₂O₄/NRGO composite is a promising cathode material for high-performance aqueous zinc-ion batteries and provides an effective strategy for developing next-generation energy storage devices.