Sustainable electrospun carbon fibre electrodes from dealkaline lignin: Towards enhanced energy storage in supercapacitors

Pursuing advanced materials from renewable sources is critical to achieving sustainable development goals. In this study, we report, for the first time, the use of dealkaline lignin as a precursor for electrospun carbon nanofibers, addressing the challenges posed by the variability of lignin sources and extraction methods on carbon fibre properties. High-surface-area carbon nanofibers were synthesised via electrospinning a dealkaline lignin and cellulose acetate solution in a binary solvent system (dimethylformamide and methanol), followed by controlled thermal treatment. The structural evolution of the fibres under varying heat treatment conditions was systematically investigated using electron microscopy, electron diffraction, and Raman spectroscopy, revealing the gradual transition from amorphous carbon to a turbostratic structure. By tuning annealing temperatures, the surface area of the carbon fibres was optimised within the range of 222–405.8 m 2 g −1 . The resulting non-activated carbon fibre electrodes demonstrated superior rate capability (86 F g −1 over a current density range of 1–10 A g −1 ). The electrodes delivered desirable energy, power densities, and robust cycling stability over 10,000 cycles when assembled into a symmetric supercapacitor. This work highlights the potential of lignin-derived carbon fibres as sustainable and efficient energy storage materials, addressing the growing global demand for renewable energy technologies. • Dealkaline lignin was used as a precursor for electrospun carbon nanofibers. • Optimised electrospinning solution enabled fibre formation and improved spinnability. • Electrodes exhibited superior rate capability, energy density, and cycling stability.