Communication—A New Additive for Increased Stabilization of Catholytes in Vanadium Flow Batteries (VFBs)

Abstract

We report a new additive, monobasic KH2AsO4, for improving the thermal stability of VFB catholytes. Using our std. accelerated testing methodol. at 30-70°, we showed that the effect increases continuously with increasing concn. of arsenate over the range studied (0-0.10 mol/dm3). In comparison to similar expts. with phosphate (H3PO4), the magnitude of the effect was greater for arsenate. A combination of arsenate and phosphate was also effective. Based on these results, we speculate that other Group-V elements in the +5 oxidn. state may also stabilize VFB catholytes. [on SciFinder(R)]