Polyacrylonitrile-based electrospun carbon paper for electrode applications

Abstract

Polyacrylonitrile (PAN)-based carbon paper with fiber diameters of 200–300 nm was developed through hot-pressing, pre-oxidation, and carbonization of electrospun fiber mats. Changes in morphology, crystallinity, and surface chemistry of the hot-pressed carbon paper were investigated. More junctions between fibers were formed with increasing hot-press time, which is attributed to melting and bonding of fibers. The bulk density increased to 0.5–0.6 g/cm[superscript 3], which could help to improve the volume energy density for electrode applications. The conductivity of the carbon paper was found to be about 40 S/cm when the surface area was ∼ 2 m[superscript 2]/g, and depends not only on the conductivity of the individual nanofibers but also on the contacts between the nanofibers. The performance of the electrospun carbon paper as an electrode for electrochemical reactions involving ferrocene molecules was affected by the preparation protocol: the higher surface area of the electrodes formed with shorter hot-press times provided a higher current generated per unit mass than that obtained with electrodes prepared using longer hot-press time, but electrodes prepared with longer hot-press times exhibited higher electrical conductivity and faster electron transfer kinetics.