Abstract
The increasing need for electrode materials exhibiting improved performance to meet the requirements of supercapacitors is on the rise. Hybrid electrodes, which combine reduced graphene (RGO) oxide with transition metal-based oxides such as cobalt oxide (CoO), have emerged as promising materials due to their impressive specific capacitance and cost-effectiveness, attributed to their synergistic properties. In the present study, a binder-free RGOCoO composite electrode was synthesized using a facile, fast, and simple one-step co-precipitation method. This was done to improve stability for supercapacitor applications. The synthesized composite materials underwent comprehensive characterization utilizing various surface analytical techniques, including X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FE-SEM), fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. Electrochemical measurements of the fabricated hybrid revealed at current density of 2 A cm− 2 a specific capacitance of 132.3 mF cm− 2, with an impressive 95.91% retention of capacitance after 7000 cycles. The results from electrochemical impedance spectroscopy (EIS) highlighted a meager low relaxation time constant of 0.53 s for the electrode. The reason behind this can be linked to the synergistic interactions, and minimal charge transfer resistance exhibited by the porous electrode without binders. The innovative simple synthesis of a binder-free RGOCoO composite electrode represents a significant advancement in the development of high-efficiency supercapacitors for diverse large-scale applications.