Eucalyptus derived heteroatom-doped hierarchical porous carbons as electrode materials in supercapacitors

Carbon-based supercapacitors have aroused ever-increasing attention in the energy storage field due to high conductivity, chemical stability, and large surface area of the investigated carbon active materials. Herein, eucalyptus-derived nitrogen/oxygen doped hierarchical porous carbons (NHPCs) are prepared by the synergistic action of the ZnCl2 activation and the NH4Cl blowing. They feature superiorities such as high specific surface area, rational porosity, and sufficient N/O doping. These excellent physicochemical characteristics endow them excellent electrochemical performances in supercapacitors: 359 F g(-1) at 0.5 A g(-1) in a three-electrode system and 234 F g(-1) at 0.5 A g(-1) in a two-electrode system, and a high energy density of 48 Wh kg(-1) at a power density of 750 W kg(-1) accompanied by high durability of 92% capacitance retention through 10,000 cycles test at a high current density of 10 A g(-1) in an organic electrolyte. This low-cost and facile strategy provides a novel route to transform biomass into high value-added electrode materials in energy storage fields.