High Volumetric Capacitance, Ultralong Life Supercapacitors Enabled by Waxberry-Derived Hierarchical Porous Carbon Materials

Supercapacitors with fast charge/discharge rate and long cycling stability (>50 000 cycles) are attractive for energy storage and mobile power supply. In this paper, a facile strategy is developed to fabricate an Fe2O3/FeS-decorated N, S-codoped hierarchical porous carbon hybrid. Its microstructure and compositions can be readily controlled through adjusting the hydrothermal reaction between waxberry and iron sulfate. The constructed supercapacitors with the as-prepared carbon materials from this reaction are able to exhibit outstanding capacitive performance with a superfast charge/discharge rate (<1 s), ultralong cycle life (>50 000 cycles, 80 A g(-1)), ultrahigh volumetric capacitance (1320.4 F cm(-3), 0.1 A g(-1)), and high energy density (100.9 W h kg(-1), 221.9 W h L-1). The outstanding performance makes it one of the best biomass-derived supercapacitors. The superior capacitive behavior is likely to arise from the N and S codoping on the surface/edge/skeleton of the carbon microspheres and nanosheet composites coupled with the fast redox reaction of Fe2O3/FeS. Overall, this research presents a new avenue for developing the next generation of sustainable high-performance energy storage device.