Silver Oxide‐Reduced Graphene Oxide Nanocomposite Electrodes for High‐Performance Alkaline Supercapacitors

Abstract

Silver oxide‐reduced graphene oxide (Ag 2 O/rGO) nanocomposites were synthesized and investigated as high‐performance electrode materials for alkaline supercapacitors. The incorporation of reduced graphene oxide significantly enhanced the electrical conductivity and, based on the observed sheet‐like morphology (SEM), is expected to provide a favorable electroactive surface area, facilitating efficient electron transport and ion diffusion. Structural and morphological characterization using X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy, scanning electron microscopy (SEM), and energy‐dispersive spectroscopy (EDS) confirmed the successful formation of Ag 2 O/rGO nanocomposite. Electrochemical performance was evaluated using cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurements. The Ag 2 O/rGO electrode delivered a high specific capacitance of 1422 F g −1 at a scan rate of 1 mV s −1 and ⁓169 F g −1 at 3.5 A g −1 . The electrode also exhibited excellent cycling stability with ⁓90% capacitance retention after 1000 cycles and a coulombic efficiency of approximately 99%. Kinetic analysis revealed a b value of ⁓0.48 and m exponent of ⁓0.5, indicating a predominantly diffusion‐controlled Faradaic charge storage mechanism. Furthermore, energy–power scaling yielded an α value of ⁓0.5, suggesting stable rate capability and hybrid electrochemical behavior. These results demonstrate that Ag 2 O/rGO nanocomposites are promising electrode materials for next‐generation high‐performance supercapacitors.