An additive-free approach for restoring the performance of vanadium redox flow batteries affected by V2O5 precipitation

Vanadium redox flow batteries (VRFBs) face a significant challenge during high-temperature operation, as the precipitation of V2O5 on the positive side obstructs electrolyte flow, drastically diminishes battery capacity, and eventually leads to battery failure. While various additives have been explored to mitigate V2O5 precipitation, it continues to occur at temperatures exceeding 40 ℃. Unfortunately, there is a lack of research focused on effective methods for removing V2O5 from the battery system. The conventional approach requires disassembling the battery stacks to eliminate V2O5, a process that is not only labor-intensive and costly but also risks damaging the performance and components of the battery. In this study, we introduce an additive free strategy that enables the removal of V2O5 from the battery without the need for disassembly, thereby fully restoring battery capacity. This method is both efficient and simple, offering a cost-effective solution for V₂O₅ dissolution while potentially simplifying VRFB electrolyte manufacturing.