Gradient-microstructural porous graphene gelatum/flexible graphite plate integrated electrode for vanadium redox flow batteries

A novel 3D electrochemically reduced graphene oxide (ERGO) porous gelatum material was self-assembled on graphite plate (GP) by the simple and controllable electrodeposition method to construct a new-type integrated electrode (ERGO-GP) for all vanadium redox flow batteries (VRFBs). Benefited from the ideal preparation method, a porous and gradient microstructure of ERGO was formed easily and facilitated the electrolyte, ions and electron transport simultaneously. Besides, the direct growth of ERGO on GP could reduce the contact resistance between the reaction layer and the conduction layer effectively. As a result, the electrochemistry and battery performance for the ERGO-GP as both negative and positive electrode of VRFBs were better than the common carbon felts (CF) and GP electrode system (CF-GP) due to the lower polarization. The obtained results also indicated the great promise of this material for application in other flow redox batteries and helped us to improve the design of carbon-based porous electrodes.