Flexible All-Solid-State Supercapacitor Fabricated with Nitrogen-Doped Carbon Nanofiber Electrode Material Derived from Polyacrylonitrile Copolymer

Carbon nanofibers (CNFs) with one-dimensional nanostructures are a promising material for energy storage. However, the development of all-solid CNF-based energy storage materials with excellent energy storage properties is still a challenge. In this study, oxygen-containing monomers were copolymerized with acrylonitrile (AN) for preparing a polyacrylonitrile (PAN) copolymer. CNFs with a tunable micropore amount and nitrogen doping were obtained from poly(acrylonitrile-co-itaconic acid) (P(AN-co-IA)) nanofibers. When used as supercapacitors, P(AN-co-IA)-derived CNFs (C-CNFs) exhibit a high specific capacitance of 347 F g–1 (0.5 A g–1), a high area specific capacitance of 84 μF cm–2, and good cyclic stability. In addition, CNFs can be assembled to prepare all-solid supercapacitor devices possessing excellent flexibility and energy storage performance. The C-CNFs show promising applications for high-performance supercapacitors.