Natural Plant Template-Derived Cellular Framework Porous Carbon as a High-Rate and Long-Life Electrode Material for Energy Storage

A superb supercapacitor with high specific capacitance and high rate capacitance has been developed from taro epidermis biomass-derived carbon materials through a mild carbonizing and activation process. The taro epidermis-derived porous carbon electrodes exhibit a unique cellular frame porous structure with combined micro- and mesopores, and show excellent supercapacitance performance, achieving superior specific capacitance (466 F g(-1) at 1 A g(-1)), high energy density (17.59 to 13.97 W h kg(-1)), and excellent rate capacitance (415 F g(-1) at 5 A g(-1) and 342 F g(-1) at 50 A g(-1)) in aqueous 6 M KOH electrolyte. Meanwhile, the taro epidermis derived electrodes demonstrate excellent cycling stability: almost no fading after 40 000 cycles at 5 A g(-1) in aqueous 6 M KOH electrolyte and 10 000 cycles at 2.5 A g(-1) in organic 1 M TEABF(4)/AN electrolyte. The results demonstrate the effective use of the framework structure of plant cell walls as the highly porous carbon materials with superior supercapacitance performance.