SYNTHESIS AND CHARACTERIZATION OF rGO AND NICKEL-COBALT OXALATE COMPOSITE MATERIALS FOR SUPERCAPACITOR ELECTRODE APPLICATIONS

Abstract

In this work, a composite material comprising nickel-cobalt oxalate and graphene (rGO@NiCo-Ox) was synthesized via a hydrothermal method for application as a supercapacitor electrode. Comprehensive characterizations of the structural and compositional properties were conducted using X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and thermogravimetric analysis (TGA). The electrochemical behavior was systematically evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The experimental results reveal that the incorporation of graphene significantly reduces both the electrical resistance and particle size of the nickel-cobalt oxalate component, resulting in the rGO@NiCo-Ox composite demonstrating markedly improved electrochemical performance compared to pristine NiCo-Ox. Notably, the rGO@NiCo-Ox electrode achieves a maximum specific capacity of 652.65 C g^-1 at a current density of 1 A g^-1, representing an enhancement of 123% over the capacity of NiCo-Ox. In addition, the composite exhibits superior cycling stability relative to the pure NiCo-Ox electrode. These findings suggest that the integration of battery-type active materials with graphene offers a compelling strategy for augmenting the electrochemical properties of single-component systems, and highlight the rGO@NiCo-Ox composite as a highly promising electrode material for high-performance supercapacitors.