Abstract
We demonstrate a novel method to accelerate electrode degradation in redox flow batteries and apply this method to the all-vanadium
chemistry. Electrode performance degradation occurred seven times faster than in a typical cycling experiment, enabling rapid
evaluation of materials. This method also enables the steady-state study of electrodes. In this manner, it is possible to delineate
whether specific operating conditions induce performance degradation; we found that both aggressively charging and discharging
result in performance loss. Post-mortem x-ray photoelectron spectroscopy of the degraded electrodes was used to resolve the effects
of state of charge (SoC) and current on the electrode surface chemistry. For the electrode material tested in this work, we found
evidence that a loss of oxygen content on the negative electrode cannot explain decreased cell performance. Furthermore, the effects
of decreased electrode and membrane performance on capacity fade in a typical cycling battery were decoupled from crossover;
electrode and membrane performance decay were responsible for a 22% fade in capacity, while crossover caused a 12% fade.
