Free-standing 3D Co₃O₄@NF micro-flowers composed of porous ultra-long nanowires as an advanced cathode material for supercapacitor

The development of smart structured cathode materials for supercapacitors (SCs) has sparked tremendous interest. However, the appropriate design to achieve high capacitance and energy density-based cathode materials remains a major problem for energy storage systems. This article describes the effective synthesis of self-supported 3D micro-flowers composed of ultrathin nanowires array of Co₃O₄ on Ni foam (NF) using hydrothermal conditions (Co₃O₄@NF). The mesoporous Co₃O₄@NF with a high surface area, providing a rich active state for the Faraday redox reaction and increasing the diffusion rate of the electrolyte ions. The optimized Co₃O₄@NF-16h electrode exhibited supreme electrochemical performance by delivering a high specific capacitance of 1878, (1127) and 1200 (720 C g⁻¹) F g⁻¹ at 1.0 and 20 A g⁻¹, respectively. The Co₃O₄@NF electrode retained good capacitance stability of 91% over 10000 cycles at 20 A g⁻¹ with excellent rate-performance of 67% at 20 folded high current values. The obtained results for the Co₃O₄@NF electrode are presented the enhanced pseudocapacitive performance, indicating the substantial potential for high-performance supercapacitor applications.