Cotton fabrics-derived flexible nitrogen-doped activated carbon cloth for high-performance supercapacitors in organic electrolyte

Abstract Activated carbon cloth, due to its excellent flexibility, good conductivity, and high surface area, is featured as a kind of promising material for energy storage devices. However, the non-optimized pore structures limit its application as electrode material in supercapacitors with organic electrolytes, which can provide both high energy density and power density due to the high applied cell voltage. In this paper, nitrogen-doped activated carbon cloth with hollow tubular fiber units, high surface area, controllable hierarchical porous structure, and beneficial surface functional groups, is synthesized via a simple ammonia treatment of commercial cotton fabrics. The resulting organic-electrolyte supercapacitors based on this hierarchical porous hollow carbon cloth exhibit a high specific capacitance (up to 215.9 F g−1 at 1 A g−1), extremely high rate capability (89% from 1 A g−1 to 200 A g−1), small IR drop (0.23 V at 100 A g−1), outstanding cycling stability (98% capacitance retention over 20 000 cycles), as well as good flexibility. This N-doped activated carbon cloth thus overcomes the drawbacks of presently available carbon cloths and opens up a new horizon toward energy storage devices with high energy density at high power density.