AbstractGraphite felt (GF) with numerous merits has been widely used as electrode in all-vanadium redox flow batteries (VRFB), but its further application is still hindered by its intrinsically poor electrocatalytic activity. Herein, we propose a three-dimensional (3D) conducting network constructed with reduced graphene oxide (rGO) in the GF electrode via a two-step method. The 3D conducting network with abundant oxygen-containing functional groups in the GF is conducive to the transport of electrons between GF fibers and the electrochemical charge transfer to vanadium ions in the composite electrode; it can enhance the electrocatalytic activity and conductivity of GF. The VRFB using 3D rGO modified GF (mGF) electrode exhibited outstanding energy efficiency of 73.4% at a current density of 100 mA·cm−2, which is much higher than that with pristine GF (pGF) (65.4%); and better rate capability. These first results reveal that GF with 3D conducting network shows promising opportunities for the VRFB and other electrochemical flow systems
Enhanced electrochemical performance of modified thin carbon electrodes for all-vanadium redox flow batteries