<p>Supercapacitors are conventional high-performance energy storage devices that boast numerous advantages, including rapid charging and discharging, as well as excellent cycle stability. The performance of these devices is contingent on the structure and composition of the electrode materials utilized. Cobalt–nickel-based bimetallic oxides have garnered significant attention as promising electrode materials due to their unique properties. In this study, we present a straightforward and cost-effective method for the synthesis of NiCo₂O₄ nanowire arrays (NWAs) on nickel foam through a single-step controlled hydrothermal and annealing process. The resulting NiCo₂O₄ NWAs electrodes demonstrate exceptional electrochemical properties, attaining a specific capacitance of 3194 F g⁻¹ at a current density of 1 A g⁻¹. The asymmetric supercapacitor assembled with NiCo₂O₄ NWAs and biomass porous carbon materials electrodes exhibited a high energy density of 16.2 Wh kg⁻¹ at a power density of 375 W kg⁻¹ and maintained approximately 97.16% of the maximum capacitance after 10000 cycles. The NiCo₂O₄ NWAs electrode materials prepared in this study demonstrated reliable electrochemical performance, underscoring their promising potential for high-performance supercapacitor applications.</p> Graphical abstract <p></p>