A review of the electrochemical activity of carbon materials in vanadium redox flow batteries

Carbon materials mainly act as the electrode in a vanadium redox flow battery (VRFB). Due to the poor electrochemical activity of traditional carbon materials for vanadium redox reactions, a comprehensive study of the electrochemical activity of carbon materials, especially graphite felt (GF), is greatly needed and has become an important feature of electrode research. This paper presents research progress on carbon materials for use in a VRFB, focusing on modifying the GF and new carbons as catalysts for vanadium redox reactions. The electrocatalytic influence of surface oxygen and nitrogen functional groups on vanadium redox reactions is introduced. The use of carbon nanotubes and graphene in a VRFB is discussed and future trends to improve the electrochemical activity of carbon materials are highlighted.