Membrane conformity assessment for Zinc-Bromine flow Batteries

Abstract

The aim of this paper is to evaluate membrane conformity assessment in determining a membrane employed in the Zinc-Bromine flow Battery (ZBB). For this purpose, two different types of membranes are used in 25 cm(2) ZBB cell operations: one is SF600, which is a porous membrane based on a hydrocarbon, and the other is Nafion 115, which is a cation-ion exchange membrane based on a sulfonated tetrafluoroethylene. Performance comparisons are carried out using a 2.0 M ZnBr2 electrolyte solution with or without a bromine-complexing agent (Methyl-Ethyl-Pyrrolidinium bromide, MEP). The experimental results indicate that in the case without MEP, Nafion 115 allows higher performance of ZBB cells than SF600, while in the case with MEP, SF600 results in higher stability and durability than Nafion 115. In conclusion, the intrinsic chemical properties of the bromine-complexing agent as well as membrane material have a significant effect on the membrane performance.