Hierarchical nanoporous activated carbon as potential electrode materials for high performance electrochemical supercapacitor

Recently, biomass-derived activated carbon nanomaterials represent a potential candidate in achieving sustainable and low-cost energy storage devices. Herein, we report a facile synthesis of hierarchical nanoporous activated carbon (NAC) by template-free and cost effective approach using bio-derived food waste namely Indian Cake Rusk (ICR) and its application in high performance supercapacitors for the first time. The influence of carbon activation process over the physicochemical properties, morphological structure, as well as supercapacitive performance was systematically studied. When used as an electrode in a supercapacitor, the as-synthesized NAC material offered a high specific capacitance of 381.0 F g(-1) at a current density of 1.7 A g(-1) with an impressive 95% capacity retention even after 6000 cycles using 1.0 M H2SO4 electrolyte. The NAC material also furnished a maximum energy density of 47.1 Wh kg(-1) and power density of 22644.0 W kg(-1) which is higher than the existing carbon based electrode using 1.0 M LiPF6 electrolyte in symmetric supercapacitor. The superior electrochemical performance of NAC material is ascribed to huge BET surface area (1413.0 m(2) g(-1)), hierarchical micro/nanoporosity, and good electrical conductivity which could serve as a promising carbon material for advanced applications in energy, environmental, and biomedical fields.