Effects of Sodium Alginate on the Composition, Morphology, and Electrochemical Properties of Electrospun Carbon Nanofibers as Electrodes for Supercapacitors

Heteroatoms-doped porous carbon nanofibers (HPCNFs) are fabricated through electrospinning of polyacrylonitrile and poly(methyl methacrylate) in N,N-dimethylformamide with sodium alginate as additive, followed by pyrolysis. The morphology and composition of the as-fabricated HPCNFs have been characterized comprehensively by a variety of methods, including scanning and transmission electron microscopies, X-ray photoelectron spectroscopy, and other spectroscopic measurements. Supercapacitors are assembled with the as-obtained HPCNFs as electrodes, and their electric capacitance performances are investigated. The supercapacitors show high specific capacitance (253.2 F/g at 0.25 A/g in 1 M H2SO4 aqueous electrolyte), excellent rate capability, and prominent cycling durability (with capacitance maintenance of 99.8% after 10 000 cycles). It has also been illustrated that the heteroatom content and the morphology of porous carbon nanofibers can be simply tuned by varying the content of SA in the precursor solution, which determine finally the electrochemical performances of HPCNFs as the electrodes in supercapacitors.