Flexible and cross-linked carbon nanofibers based on coal liquefaction residue for high rate supercapacitors.

• CLACF was obtained by controlling the stabilization parameters and carbonization. • CLACF shows good electronic conductivity due to the cross-linked structures. • It exhibits a rate capability of 65.8% as the current from 0.2 to 100 A g− 1. • It delivers a energy density of 4.20 Wh kg− 1 and a power density of 1.22 kW kg−1. • It also shows perfect cyclic stability of 97.3% after 10,000 cycles at 2 A g−1. [Display omitted] Free-standing electrospun carbon nanofibers nonwovens (CNF) with an outstanding cross-linked architecture can be successfully achieved via a simple and practicable strategy by combining electrospinning, stabilization and carbonization. In this study, the hybrids of asphaltene extracted from coal residue liquefaction, polyacrylonitril and terephthalic acid are used as precursors. Due to the synergistic effect of efficient cross-linked structures and short charge transfer channels, flexible cross-linked asphaltene-based CNF (CLACF), as the binder-free supercapacitor electrode, exhibits a high capacity of 225 F g−1 at 0.2 A g−1 and an outstanding rate capability of 148 F g−1 at 100 A g−1. The developed symmetrical supercapacitor based on CLACF has a maximum energy density of 4.20 Wh kg−1 with a power density of 1.22 kW kg−1. It also has excellent cyclic stability with 97.3% capacitance retention after 10,000 cycles at 2 A g−1. [ABSTRACT FROM AUTHOR]