Effect of Operating Conditions on the Capacity of Vanadium Redox Flow Batteries

Abstract

Vanadium redox flow batteries (VRFBs) present a viable solution to address the intermittent power output challenge associated with wind and solar energy generation. However, their development is impeded by their low energy density and high cost. To achieve the objective of cost reduction, it is crucial to optimize operating conditions, minimize capacity loss, and enhance battery performance. Through meticulous experimental analysis, this study thoroughly examines the impact of membrane thickness, current density, flow rate, and self-discharge on battery capacity. The experimental findings reveal that an increase in membrane thickness results in elevated resistance to proton transport, thereby weakening electrochemical reactions. Moreover, surpassing critical values for current density and flow rate also leads to a decrease in capacity. Prolonged shelving induces severe self-discharge reactions that accelerate deterioration of capacity fade. This research suggests that obtaining optimal operational parameters can effectively mitigate battery capacity fade.