Effect of modification of polyacrylonitrile-based graphite felts on their performance in redox fuel cell and redox flow battery

The electrochemical behavior of nitrogen-doped polyacrylonitrile (PAN) -based graphite felt prepared by three pretreatment methods for the reaction of Fe3+/Fe2+ was investigated. Then the effects of three pretreatment, including doped nitrogen, heat treatment and acid treatment, on the 9,10-anthraquinone-2,7-disulphonic acid (AQDS) electrochemical reaction activity of the PAN-based graphite felt were investigated and compared. The crystal structure, the surface morphology, and surface chemical composition of the PAN-based graphite felt were characterized by X-ray diffraction, scanning electron microscopy and X-ray electron spectroscopy. The results of the electrochemical performance showed that the nitrogen content can influence the activity of PAN-based graphite felt in the reaction of Fe3+/Fe2+. Besides, the activity of PAN-based graphite felt in the AQDS electrochemical reaction was affected by the content of COOH group on the surface of graphite felt.