Annealing optimization of graphitized Co₃O₄@CuO@NiO composite electrodes for supercapacitor applications

In recent times, carbon‐based material has received a keen interest in the fabrication of electrodes because it enhances the performance of energy storage devices. Amalgamated composites of three transition metals (Co 3 O 4 @CuO@NiO) and graphene oxide (GO) were fabricated employing the hydrothermal method. The performance of some fabricated electrodes was optimized by annealing using various temperatures, examined for supercapacitor application using a three‐electrode system. Our results indicate that Co 3 O 4 @CuO@NiO‐amalgamated electrode optimized using 100°C temperature shows enhanced features compared to deposited and other samples annealed at various temperatures. These discoveries also showed that Co 3 O 4 @CuO@NiO‐amalgamated electrode optimized using 100°C temperature delivered a specific capacitance of 1312 F/g from cyclic voltammetry analysis using 10.0 mV/s scan rate and 1258 F/g from galvanostatic charge–discharge analysis using 1.0 A/g current density. The cycling stability of electrodes annealed at 100°C was 92.5% after 10 000 cycles, indicating that annealing at 100°C enriched electrode characteristics.