Nanosheet Arrays of NiS/Ni ₃ S ₄ Supported on Thermally Activated Carbon Cloth for High‐Performance Hybrid Supercapacitor Electrodes

Abstract Transition metal sulfides are promising candidates for energy storage applications due to their rich Faradaic activity and high theoretical specific capacities. However, their practical performance is often hindered by intrinsically low electrical conductivity and degradation from prolonged cycling. In this study, a binder‐free composite electrode was fabricated by directly growing NiS/Ni 3 S 4 nanosheet arrays onto thermally activated carbon cloth through a facile one‐step hydrothermal method. The conductive and robust substrate facilitates efficient charge transport while maintaining structural integrity during operation. The optimized NiS/Ni 3 S 4 @TACC‐10 electrode delivers a high specific capacity of 285 mAh g −1 at 2 A g −1 and retains 63.1% of its capacity at 10 A g −1 . The corresponding hybrid supercapacitor exhibits an impressive energy density of 97.4 Wh kg −1 and maintains 102.6% of its initial capacitance after 3000 cycles at 20 A g −1 . Moreover, three such devices connected in series successfully powered red LEDs for over 20 min, highlighting their potential for real‐world energy storage applications. These results offer a scalable and effective strategy for the development of high‐performance electrochemical energy storage systems.