Engineering asymmetric hybrid supercapacitor electrode ACB/g-C₃N₄/NiO nanocomposite for high-performance energy storage

As appetite steadily grows for sustainable in the same vein high-performance need for better energy storage has sparked a surge of research into activated carbon-based supercapacitor electrodes derived from biomass. They have attracted immense interest due to its cost-effectiveness, natural abundance, eco-friendly synthesis, from agricultural waste, fruit peels, and plant residues exhibits tunable porosity, a substantial surface area-rich surface and active sites, making it highly suitable for electrochemical applications. The synthesis of ACB/g-C₃N₄/NiO nanocomposite involved the use of Ni(NO₃)₂, NaOH, melamine, banana peel waste, HCl, KOH, PVDF, − (C₂H₂F₂)_n −), carbon black, and N-methyl-2-pyrrolidone. Banana peel waste as a cost-effective and eco-friendly precursor was used to synthesize activated carbon (ACB) and was subsequently combined with g-C₃N₄ and NiO to form a hybrid nanocomposite with enhanced electrochemical performance. Electrochemical performance of ACB/g-C₃N₄/NiO shows a high specific capacitance of 883.26 Fg⁻¹ at 1 Ag⁻¹, excellent cycling stability with 94.21% retention over 5000 cycles in three-electrode system. ACB/g-C₃N₄/NiO device demonstrated an energy density of 57.84 Wh kg⁻¹ and power density of 3838.87 Wkg⁻¹, highlighting its excellent charge storage capability. The electrode maintains exceptional cycling stability, a remarkable 92.82% capacitance retention was observed after 10,000 cycles, confirming the long term.