Ni/Ni–Al–Layered Double Hydroxide on Carbon Cloth–Based Flexible Electrode for High Performance Supercapacitor

Electrodes with high surface area, rapid charge transport, and mechanical robustness are essential for high-performance supercapacitors. In this study, a flexible Ni/Ni–Al layered double hydroxide/activated carbon cloth (Ni/Ni–Al–LDH/ACC) electrode was fabricated through a two-step process comprising potentiostatic Ni electrodeposition followed by hydrothermal growth of Ni–Al–LDH on ACC. The hybrid architecture enhanced ion diffusion and electron transport, leading to significantly improved electrochemical performance. The Ni/Ni–Al–LDH/ACC electrode delivered a high specific capacitance of 867.50 F/g@0.40 F/cm 2 at 7.00 mA/cm 2 , with an energy density of 27.00 Wh/kg and a power density of 3.33 × 10 3 W/kg, retaining 91.20% of its capacity during cycling. An aqueous asymmetric supercapacitor assembled using Ni/Ni–Al–LDH/ACC//ACC exhibited a specific capacitance of 7.68 F/g@0.74 F/cm 2 , together with an energy and power density of 1.91 Wh/kg@726.70 W/kg and a cycling stability of 86.50%. These results demonstrate the material’s strong potential as a low-cost, flexible, and high-efficiency electrode for next-generation energy-storage devices.