Nitrogen-doped carbonized cotton for highly flexible supercapacitors

A facile and cost-effective approach to electrodes made from nitrogen-doped carbonized cotton is disclosed. These are further used in flexible supercapacitors. The resulting supercapacitors have a specific capacitance of 207 F/g at 1.0 A/g, high energy density of 7.2 Wh/kg at 1.0 A/g, and power density of 3823 W/kg at 14 A/g. The composite also demonstrates excellent long-term cycling stability with 34% capacitance increase after 10,000 cycles and mechanical flexibility with 40% capacitance increase after 4000 bending cycles. The synergistic combination of the microporous structure and N-doping leads to the improved electrochemical performance in this cotton-derived system.