LAUSR

Abstract Naturally nitrogen-doped porous carbon is acquired from the fruit of Metasequoia (dawn redwood cone) by two facile steps of pre-carbonization and chemical activation. Current collectors coated with the porous carbon as electrodes are evaluated in 6.0 M basic electrolyte for the application of electrochemical capacitors. Results show that the porous carbon obtained with an activated temperature of 700 °C keeps the highest specific surface area (1,831 m2 g−1) and the largest pore volume (0.92 cm3 g−1). In three-electrode test, the carbon based electrode not only possesses an outstanding capacitive performance up to 326 F g−1 and 236 F g−1 at current densities of 0.5 A g−1 and 10 A g−1, respectively, but also shows a stable cycling characteristic. The two-electrode symmetric device also harvests a specific capacitance of 197 F g−1 at a current density of 1.0 A g−1 and an excellent energy density as high as 7.6 W h kg−1. Our study suggests that the cone can be applied as a promising and almost zero-cost precursor in fabricating porous carbon samples for supercapacitor, thanks to the abundance of resources.