Experimental Validation of Side Reaction on Capacity Fade of Vanadium Redox Flow Battery

Abstract

The all-vanadium redox flow battery (VRFB) is widely regarded as the most effective solution for mitigating the intermittent nature of renewable energy sources and simultaneously achieving “carbon neutrality goals.” Nevertheless, the battery’s overall performance is adversely affected by capacity loss resulting from side reactions, hence constraining its viability for usage in large-scale energy storage systems. This study proposes a novel approach that aims to minimize side reactions and mitigate capacity fade by employing an appropriate charge cut-off voltage mechanism. The experiment centers around the examination of performance indicators, including battery charge/discharge capabilities, internal resistance, capacity retention rate, and efficiency, for analytical purposes. The findings indicate that by setting the charge cut-off reference voltage at 1.65 V, the battery’s capacity can be sustained at 61.76% after 60 cycles. When the charge cut-off voltage is raised by increments of 0.1 V and 0.15 V, the corresponding reductions in battery capacity amount to 1.74% and 5.16% respectively. The aforementioned findings emphasize the significance of considering the effect of side reactions on battery capacity and implement that mechanism can significantly enhance the battery’s overall performance.