Redox flow batteries (RFBs) are the most preferred technology for primary grid-scale storage systems, as their power and energy can be decoupled. Unlike conventional battery, RFBs can store energy for a longer duration (say for months), and it has the ability to respond fast in the event of destabilization of grid1. Over the past forty years, various RFBs such as the Fe-Cr, Zn-Br2, soluble lead-acid, all vanadium etc., have been the subject of extensive research2. Among the RFBs, vanadium redox flow battery (VRFB) can be a favorable for stationary energy storage applications owing to additional advantage of having a single element in four oxidation states. Single element-based electrolyte makes the cross-contamination a less of a concern3. However, VRFB uses an cation ion exchange membrane which cost around 30-35% of overall cost and pricing of vanadium is highly volatile, which makes its future uncertain in the energy storage domain4. In this context, improving the performance of the VRFB modifying electrode and membrane have been explored. Besides, a cost-effective, membrane-less soluble lead acid redox flow battery (SLRFB) has been explored. In SLRFB, Pb and PbO2 get deposited on the anode and cathode respectively during charging and during discharge both Pb and PbO2 dissolve back as Pb2+ ions. Although it is a membrane-less technology, the system is not yet commercialized due to limited cycle life. The performance of SLRFB is hindered due to various reasons such as Pb dendrites growth, sluggish kinetics of Pb2+/PbO2 redox couple, partial reversibility of PbO2 and O2 evolution at cathode5.
This research colloquium seminar will be focusing on electrode and membrane modification to achieve higher performance of VRFB. Besides, new electrolyte formulation based on cationic surfactant is introduced to improve the cycle life of SLRFB. Also, multicell stack performance of VRFB and SLRFB will be discussed.
References
1. A. A. Kebede, T. Kalogiannis, J. Van Mierlo, and M. Berecibar, Renew. Sustain. Energy Rev., 159, 112213 (2022).
2. M. Bartolozzi, J Power Sources, 27, 219–234 (1989).
3. M. Raja, H. Khan, S. Sankarasubramanian, D. Sonawat, and V. Ramani, Catal. Today, 15, 181–188 (2021)
4. H. Khan, R. Murugan, and K. Ramanujam, J. Electrochem. Soc., 168, 100542–100552 (2021)
5. N. Jaiswal, H. Khan, and R. Kothandaraman, J. Electrochem. Soc., 169, 040543 (2022).