S, N co-doped porous carbon materials for high performance supercapacitor

Herein, the porous carbon material co-doped with nitrogen and sulfur was prepared by one-step activation carbonization method. Porous carbon materials were synthesized with polyimide as carbon source, urea as nitrogen source and KOH as activator. The S, N-PIC-1-based electrode achieves ultra-high specific capacity of 235.3 F g−1 at 0.5 A g−1, and the 96.00 % capacitance can be maintained for 10,000 cycles at 10 A g−1. The symmetrical supercapacitor (S, N-PIC-1//S, N-PIC-1) based on polyimide derived carbon in the electrolyte of 2 M KOH, 0.5 M Na2SO4 and 1-Butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) have been studied. More important, S, N-PIC-1//S, N-PIC-1 in BMIMBF4 electrolyte has a wide working voltage of 0–3.0 V and the high energy density of 40.95 Wh kg−1 at 749.2 W kg−1.