Tunable N-F-O tri-doped flexible hierarchical porous carbon nanofibers derived from electrospun PVP/PTFE nanofibers towards high electrochemical performance for energy storage

Porous carbon nanofibers (PCNFs) offer the advantage of abundant pathways for ion, molecule, and nanoparticle transport, but controlling their porous structure remains a significant challenge. This study employed polytetrafluoroethylene (PTFE) as a pore-forming agent and polyvinylpyrrolidone (PVP) as a carbon precursor to prepare flexible, geometrically adjustable PCNFs with a hierarchical pore structure using a macro-micro dual-phase separation method. The negatively charged PTFE template crosslinks with positively charged PVP carbon precursor, forming stable electrospinning solution. By varying the mass ratio of PVP to PTFE, the pore structure and pore size distribution of PCNFs can be adjusted. 1–2 PCNFs (1PVP/2PTFE) exhibit high capacitance of 397.14 F/g at a current density of 1 A/g due to their higher specific surface area and reasonable pore structure and distribution. Additionally, it has excellent rate capability and cyclic stability at a current density of 10 A/g with a capacitance retention exceeding 100 % and coulombic efficiency remaining above 96.5 % after 5000 cycles. The hierarchical porous structure, N-F-O ternary doping, and high conductivity network proposed in this paper effectively enhance the electrochemical performance of PCNFs films. The method employed in this study can effectively realize high-performance electrode materials, with promising prospects for potential applications in energy storage.