Abstract
The addition of bromine complexing agent (BCA) to bromine electrolyte is an accepted method to reduce bromine vapor pressure making bromine-based flow batteries inherently safer. It is well-known that the amine functional group of the BCAs interact with Nafion membranes. The novelty of the current work is that it investigates how this interaction of BCA with the four different membrane chemistries impacts the membrane characteristics and performance of hydrogen bromine flow batteries (HBFBs). The impact of BCA 13 on the system performance is determined by the membrane chemistry. Exposure of Nafion membranes to BCA leads to 60% higher cell resistance, and 55% lower cell power density at 0.5 V at 50% state-of-charge (SOC). This decrease is caused by the strong interaction between the negatively charged sulfonic acid groups in the membrane and the positively charged BCA. Lower SOC, lower bromine concentration and a higher free BCA concentration is detrimental in the cell operation. The use of LC PFSA membranes in the presence of BCA ions should be avoided. while BCA in combination with grafted sulfonated polyvinylidene fluoride (SPVDF) or grafted sulfonated polyethylene (SPE) membranes promising HBFB results are obtained.
Original language | English |
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Pages (from-to) | A3004-A3010 |
Number of pages | 7 |
Journal | Journal of the Electrochemical Society |
Volume | 166 |
Issue number | 13 |
DOIs | |
Publication status | Published - 3 Sept 2019 |
Funding
The research leading to these results has received funding from EFRO/OP-Oost (project Hydrous II), funding from European Union Interreg program Deutschland-Nederland (project CEC) and funding from the European Union’s Horizon 2020 Research and Innovation Program (project GIFT). The authors also would like to thank ICL Industrial Products for supplying BCA 13 and Dr. Ran Elazari for the fruitful discussions and support.