Carbon Nanofibers Prepared from Solar Pyrolysis of Pinewood as Binder-free Electrodes for Flexible Supercapacitors

Solar pyrolysis of renewable biomass has huge potential for sustainable production of fuel or chemical feedstock for the activated carbon materials. Here, we report a method for producing high-quality carbon nanofiber (CNF) precursor and subsequently CNFs as a low-cost and eco-friendly energy storage material. Specifically, pinewood is pyrolyzed with solar energy to generate a phenol-rich bioliquid precursor that is found to be a strong candidate for synthesizing binder-free flexible electrode materials via electrospinning. The CNFs prepared with 30% solar-driven bioliquids and 70% polyacrylonitrile have a high specific surface area and rich microstructure, which are the key to its electrochemical performance in terms of specific capacitance (349 F g⁻¹ at the current density of 0.5 A g⁻¹) with notable rate performance, reversibility, and cycling stability in 6 M KOH aqueous electrolyte. Thus, solar bioliquids are feasible CNF precursors, and such derived CNFs have potential to be applied in energy storage devices.