Hierarchical Lotus-Seedpod-Derived Porous Activated Carbon Encapsulated with NiCo(2)S(4) for a High-Performance All-Solid-State Asymmetric Supercapacitor

Converting biowaste into carbon-based supercapacitor materials provides a new solution for high-performance and environmentally friendly energy storage applications. Herein, the hierarchical PAC/NiCo(2)S(4) composite structure was fabricated through the combination of activation and sulfuration treatments. The PAC/NiCo(2)S(4) electrode garnered advantages from its hierarchical structure and hollow architecture, resulting in a notable specific capacitance (1217.2 F g(−1) at 1.25 A g(−1)) and superior cycling stability. Moreover, a novel all-solid-state asymmetric supercapacitor (ASC) was successfully constructed, utilizing PAC/NiCo(2)S(4) as the cathode and PAC as the anode. The resultant device exhibited exceptionally high energy (49.7 Wh kg(−1)) and power density (4785.5 W kg(−1)), indicating the potential of this biomass-derived, hierarchical PAC/NiCo(2)S(4) composite structure for employment in high-performance supercapacitors.