Flexible and cross-linked N, S co-doped carbon nanofiber nonwovens derived from coal liquefaction residue for high performance supercapacitors

Flexible, appropriate N, S co-doped electrospinning carbon nanofiber nonwovens with amazing cross-linked architecture (N, S-CLPACF) are successfully achieved in a simple and practicable approach involving the electrospinning of preasphaltene derived from the coal liquefaction residue/polyacrylonitrile/terephthalic acid composite precursor, followed by stabilization, (NH4)2SO4 soaking and carbonation. The degree of cross-link in the structures could be easily adjusted by modulating the temperature during the stabilization. Due to the synergistic action of efficient inter-bonded structures, short charge transfer channels and heteroatom doping, the N, S-CLPACF electrode exhibits a high capacity of 267 F g−1 at 0.2 A g−1 and an outstanding rate capacity of 178 F g−1 at 100 A g−1. A symmetrical supercapacitor assembled using the N, S-CLPACF electrode delivers a high energy density of 4.7 Wh kg−1 at a power density of 1.2 kW kg−1 and shows a capacitance retention rate of 98% after 10000 cycles at 2 A g−1. N, S-CLPACF were successfully achieved in a simple and practicable way through electrospinning preasphaltene derived from coal residue liquefaction/polyacrylonitrile/terephthalic acid composite precursor, followed by stabilization, (NH4)2SO4 soaking and carbonation. The N, S-CLPACF electrode exhibits a high capacity of 267 F g−1 at the current density of 0.2 A g−1 and outstanding rate capacity (178 F g−1 at 100 A g−1).