Buckwheat core derived nitrogen- and oxygen-rich controlled porous carbon for high-performance supercapacitors

We propose a simple and effective one-step activation route to prepare a hierarchically porous carbon with buckwheat core acting for precursor. The as-obtained porous carbon (BCPC-3) shows high specific surface area (805.91 m(2)/g) and high pore volume (0.60 cm(3)/g). As a supercapacitor electrode material for three-electrode, porous carbon delivers an ultrahigh capacitance of 330 F/g (at 0.5 A/g) in 6 mol/L KOH. In particular, it displays a capacitance of 140 F/g even when the current density increases to 100 A/g. In addition, in the two-electrode system, a symmetric supercapacitor based on buckwheat core with a controlled carbon structure can provide an output of 6.1 W center dot h/kg in a 6 mol/L KOH electrolyte. Therefore, this research offers a straightforward and cost-effective pathway for the fabrication of superior supercapacitor electrode materials.