Synergistic Ni-Mn ferrite/rGO nanocomposites for high-performance supercapacitors

Abstract

To address the growing demand for advanced energy storage systems, Ni-Mn ferrite (Ni-Mn(1-x)Fe2O4) nanoparticles integrated with reduced graphene oxide (rGO) were synthesized via a sol-gel-assisted co-precipitation method. Different concentration ratios of (Ni-Mn(1-x)Fe2O4)/ rGO have been tried with sample codes NMR33, NMR50, and NMR67 for optimization of supercapacitive performance. This hybrid approach aimed to synergistically enhance the electrochemical performance by improving electrical conductivity, surface area, and structural integrity. Comprehensive structural and morphological analyses, conducted using XRD, FESEM, FTIR, and TGA, confirmed the successful formation of the nanocomposites. Electrochemical evaluations, including cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) in a 6 M KOH electrolyte, revealed that the NMR50 composition exhibited the highest specific capacitance of 250 F/g at 1 A/g and retained 97% of its capacitance after 10,000 charge-discharge cycles. This superior performance is attributed to the optimized Ni/Mn ratio and the strong interfacial coupling between the redox-active ferrite phase and the conductive rGO matrix, which facilitates efficient electron transport and ion diffusion. The results underscore the potential of Ni-Mn ferrite/rGO nanocomposites as promising electrode materials for next-generation supercapacitor applications.