Bamboo-derived porous carbons for Zn-ion hybrid supercapacitors

A simple one-step combustion reaction between 2-methylimidazole (C₄H₆N₂) and sodium nitrate (NaNO₃) is employed to convert bamboo powder to produce an N, O co-doped porous carbon (BC-CNa) for usage as a zinc-ion hybrid supercapacitor (ZnHS) cathode material. The as-prepared BC-CNa owns proper N, O co-doping, diverse carbon defects, and high specific surface area and pore volume. Owing to the combined effect of these features, the ZnHS fabricated with this BC-CNa as the cathode material exhibits much higher specific capacities and energy densities than the ZnHSs based on pristine bamboo-derived carbon (BC), bamboo plus C₄H₆N₂ derived carbon (BC-C), and bamboo plus NaNO₃ derived carbon (BC-Na). The maximum specific capacity and energy density of BC-CNa based ZnHS can reach 51.4 mA h g^–1 and 48.3 Wh kg^–1, respectively. And this ZnHS also exhibits superb cycle stability with 96 % capacity retention after 90,000 cycles.