Electrochemical Behavior of Porous Carbon Nanofibers Developed from Polyacrylonitrile/ Graphene Solutions Containing Zinc Chloride

Graphene-embedded porous and smaller fibrous carbon nanofibers (CNFs) were prepared by a simple electrospinning method with the help of zinc chloride (ZnCl2), and their electrochemical properties as supercapacitor electrodes were investigated. The CNFs were characterized as having a large specific surface area of up to 520 m2g-1, mesopore volume fraction up to 35%, and high electrical conductivity (over 0.45 Scm-1) and exhibited a gravimetric capacitance of 148 Fg-1 and energy densities of 9.2-20.0 Whkg-1 over a power density range of 400-30,000 Wkg-1 in 6 M potassium hydroxide electrolyte. The introduction of ZnCl2 and graphene into the polyacrylonitrile (PAN) solution induced suitable micropores to accommodate many ions for high capacitance and mesopores for smooth ion transfer. Therefore, the cooperation of micro- and mesopores in the CNF electrode materials synergistically improves the performance of electrochemical double-layer capacitors (EDLCs) because these materials have a high rate capability, high capacitance, and long cycling life.