Performance Enhancement of Reduced Graphene Oxide‐Modified Carbon Electrodes for Vanadium Redox‐Flow Systems

Reduced graphene oxide (rGO) suspended in an N,N′‐dimethylformamide (DMF) solvent underwent electrophoretic deposition (EPD) on carbon paper (CP) electrodes. X‐ray computed micro‐tomography (XMT) indicates a 24 % increase in the specific surface area of CP modified with rGO in comparison to the untreated sample. Furthermore, XMT confirms that the deposition also penetrates into the substrate. Raman analysis shows that the rGO deposited is more amorphous than the CP electrode. A significant reduction in charge‐transfer resistance of the VO2+/VO2+ reaction is also observed (from impedance measurements) in modified samples in comparison to untreated CP electrodes. X‐ray vision: Carbon paper (CP) electrodes are modified with reduced graphene oxide (rGO) by using electrophoretic deposition. X‐ray tomography is used for the first time to characterize the deposits that result in enhanced charge‐transfer performance for the VO2+/VO2+ redox couple.