264825 Electrolyte Optimization for Fe/V Redox Flow Battery System
Electrolyte optimization for Fe/V redox flow battery system
Bin Li, Wei Wang, Zimin Nie, Vince Sprenkle, Baowei Chen, Xiaoliang Wei, Qingtao Luo, Guanguang Xia, Liyu Li and Zhenguo Yang
Pacific Northwest National Laboratory
902 Battelle Boulevard, PO Box 999, Richland, WA 99354
Redox flow batteries (RFBs) research and development have recently enjoyed a renaissance primarily due to their ability to store large amounts of power and energy, up to multi-MW and multi-MWh, respectively, for renewable energy integration or smart-grid deployment.1 Broad market penetration, however, has not been achieved due to several limitations such as high cost, instability in long-term operation, and narrow operational temperature range, etc. Recently invented Fe/V redox flow battery (IVRFB) has attracted more and more attentions due to its long-term cycling stability and the freedom to utilize membranes other than expensive Nafion.2 In this study, extensive matrix study was performed on the Fe/V electrolyte in order to determine the relationships of the composition, state of charge (SOC), and temperature stability. As we know, the temperature stability of the RFB systems is of paramount importance for practical use. A RFB system with wider temperature stability will not only enable the RFB to be deployed with less geographical limitation, but also possibly eliminate the active temperature management system reducing parasitic loss. As previously reported, the current Fe/V electrolyte cannot be operated or stored at lower temperatures (≤ 0oC) due to the precipitations (FeCl2). In this research, factors influencing the stability of electrolytes in both positive and negative half-cells with different SOCs at different temperatures from -10oC to 40oC were systematically studied. Through the optimization of the electrolyte composition, an electrolyte stable in the temperature range from -5oC to 40oC was identified. Electrolyte stability data and IVRFB flow cell cycling performances using low-cost separators will be presented (Fig.1).
Fig.1 Cycling performances of optimized Fe/V electrolytes
See more of this Group/Topical: Sustainable Engineering Forum