Doping of nitrogen into biomass-derived porous carbon with large surface area using N2 non-thermal plasma technique for high-performance supercapacitor

Abstract

A novel and facile modified method using non-thermal plasma is proposed to insert N active sites into biomass-derived porous carbon as high-performance electrode materials for supercapacitor. Large surface areas up to 3040.3 and 2662.5 m2/g with mesopore-dominant hierarchical porous carbons are produced from biomass of lilac and lotus seedpods via KOH activation, respectively. The lilac and lotus seedpods derived porous carbon electrodes present good specific capacitances of 214.5 and 201.1 F/g, respectively. N2 non-thermal plasma modification successfully increases N-containing groups on lilac and lotus seedpods derived porous carbons, where the corresponding N atomic contents are increased by 10.2 and 3.6 times, respectively. As supercapacitor electrodes, their specific capacitances are improved greatly after plasma modification and up to 342.5 F/g (increased by 59.7%) and to 332.1 F/g (increased by 65.2%) at 0.5 A/g in 6 M KOH electrolyte with excellent cycling stability of 85.2% and 95.4% at 10 A/g after 5000 cycles, respectively.