3D-printed graded graphene aerogel electrode for vanadium redox flow battery

In this paper, the performance of 3D-printed graphene aerogel composite electrodes with different pore structure for vanadium redox flow battery (VRFB) application were simulated and experimentally verified. The influence of pore structure of electrode on the distribution of vanadium ions concentration, electrode potential, electrolyte potential and electrode overpotential during galvanostatic discharge was analyzed. The results revealed that the 3D-printed graphene aerogel composite electrode with 2–3 mm graded structure has the lowest overpotential, resulting in the highest discharge capacity and energy efficiency. The reasonably designed 3D printed graphene aerogel electrode with graded structure effectively minimizes electrolyte transfer resistance, while ensuring sufficient reaction sites near the membrane side. Furthermore, 3D printing technology provides a promising method for the synergistic optimization of mass transfer and electrochemical kinetics in porous electrode, which may promote the research of porous electrode design in VRFB. [Display omitted] •A 3D printed graphene aerogel electrode with graded pore structure was developed.•The electrode balances the mass transfer resistance and increases the reaction surface area.•The electrode has the lowest overpotential and concentrated reaction on the membrane side.•The electrode has the largest discharge capacity of 714.9 mA·h and the highest energy efficiency.