Carbon black-based porous sub-micron carbon fibers for flexible supercapacitors

[Display omitted] •Carbon black (CB) is constructed into carbon fibers with pyrolytic carbon as binder.•The CB-based carbon fibers inherit abundant surface area from porous CB.•Increasing CB content enhances the flexibility and conductivity of the carbon fibers.•The CB-based carbon fiber is a candidate electrode for flexible supercapacitors. Construction of functional materials using low-dimensional carbons has attracted tremendous attention in the field of energy storage devices. Herein, porous carbon black (CB) is used as the dominant building unit to construct porous sub-micron carbon fibers by electrospinning and pyrolysis with polyacrylonitrile (PAN)-based pyrolytic carbon as the binder. Inheriting abundant pores and surface area from the porous CB, the resultant CB-based sub-micron fibers present considerable porosity and specific surface area. The PAN-based pyrolytic carbon endows the CB-based sub-micron carbon fibers with a considerable quantity of N/O-containing surface. CB content plays a crucial role in improving thermal stability, flexibility, and conductivity of the resultant sub-micron carbon fibers. The CB-based sub-micron carbon fibers present a considerable specific capacitance, excellent cycling stability and can be used electrodes for flexible supercapacitors.