Fabrication of electrospun n, p-doped carbon nanofiber mat using polyacrylonitrile (PAN) and polyacrylonitrile-co-vinyl imidazole blend precursor for supercapacitor applications

Carbon-based electrode materials are still a challenge when it comes to achieving high volumetric capacitance and cyclic performance to meet the needs of the new generation supercapacitors. In this study, free-standing binder-free heteroatoms-doped carbon nanofiber (CNF) mats were prepared via electrospinning of a precursor polymeric blend of polyacrylonitrile (PAN) and polyacrylonitrile-co-vinylimidazole (PAN-co-VIM) containing varying concentrations of ammonium dihydrogen phosphate (NH₄H₂PO₄) as a dopant source, followed by carbonization and optimizing their textural and electrochemical properties as a function of dopant concentration. The as-prepared doped CNFs were further characterized with various spectroscopic techniques, and the results were corelated with their capacitive performances. The N, P-doped CNFs (NP-CNFs) obtained from blend precursor with 5 Wt% NH₄H₂PO₄ (NP-CNF 5) demonstrated a maximum specific surface area of 1.552 m²/g with a mesopore volume of 3.5404 × 10^–4 cm³/g. The NP-CNF 5 delivered a highest gravimetric capacitance of 384.58 F/g, volumetric capacitance of 768.86 F/cm³ and an excellent cycling stability.