Tea waste derived microporous active carbon with enhanced double-layer supercapacitor behaviors

Abstract

Activated carbon (TC1200) is prepared from tea waste via activation and carbonization. The specific surface area of TC1200 is 911.92 m2 g−1 and N-doping is achieved simultaneously due to the existence of N-enriched components in the carbon precursor. The TC1200 exhibits superior capacitive performances on a symmetric supercapacitor in the aspects of ultralong cycle stability (96.66% capacitance retention after 16,000 cycles at 4 A g−1) and ultrahigh power density (33,494.70 W kg−1 for an energy density of 19.45 Wh kg−1). The enhanced electroconductivity and the excellent wettability provided by the N elements synergistically facilitate the diffusion of the electrolyte ion into the bulk of the carbon material, greatly contributed to the double-layer capacitive behavior and the capacitance of the carbon material. This methodology supports the high-value added utilization of the biomass and provides an opportunity for the scalable production of activated carbons for supercapacitor energy storage devices.