Direct ink writing (DIW) of graphene aerogel composite electrode for vanadium redox flow battery

This paper proposes the reduced graphene oxide (rGO)/Super-P aerogel composite electrode with controllable porous structure based on direct ink writing (DIW). To inspect its potential in vanadium redox flow battery (VRFB), scanning electron microscope (SEM), X-ray energy dispersive spectrum (EDS), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) test and charge-discharge test are conducted. The results reveal that the composite aerogel electrode originated from GO/Super-P mass ratio of 2:1 exhibits the best cell performance. Ascribing to the high conductivity, high specific area and reasonable hierarchical porous structure, the cell with optimized rGO/Super-P aerogel electrode shows superior discharge capacity of 848.4 mA h at the current density of 80 mA cm−2, which increases by 14.9% compared to that equipped with traditional graphite felt (GF). Ascribing to the advantages of controllable porous structure, energy-saving and facile synthesis process originated from DIW, the proposed aerogel electrode may provide an alternative to GF and exhibit promising potential in VRFB. •3D printed graphene aerogel using direct ink writing technology as the electrode.•3D aerogel electrode without high temperature treatment possesses a designable shape.•The cell using the 3D aerogel electrode shows high discharge capacity.