High-value utilization of lignin to fabricate carbon nanofibers for supercapacitors has drawn much attention due to its sustainability. However, the heterogeneity of crude lignin structure led to the comparatively poor performance of lignin-based carbon nanofibers (LCNF) as electrodes in supercapacitors. Herein, flexible and porous LCNF simultaneously doped with N, S and Zn were firstly synthesized by electrostatic spinning followed by carbonization. The obtained L-NS20-Zn15 fibers showed optimum specific capacitance of 328.6 F g