Influence of Convection and Material Properties in Vanadium Redox Flow Batteries

Substantial work has been done recently to improve performance of all-vanadium redox flow batteries (VRFB) as a viable large scale energy storage system1. Prototype systems have been installed in small numbers to demonstrate their feasibility. There still exists a lack of understanding of the processes and design tradeoffs which exist in these systems, particularly regarding the relationship between mass transport, performance, realized capacity accessed, and parasitic pressure losses through the system. Despite the literature available regarding this particular chemistry, a thorough analysis of the design tradeoffs and their impact on system optimization is still lacking. Flow field design is one such area where an opportunity for optimization exists for mass transport and system pressure drop. Such optimization can be experimentally explored, as well as computationally2. This combined experimental and computational study that will be presented will show that optimal flow field design is not simply related to the architecture, but is instead a more complex interplay between architecture, electrode properties, electrolyte properties, and operating conditions. The results of this study should be useful to design engineers seeking to optimize VRB systems through enhanced performance and reduced pressure drop. 1. D.S. Aaron, Q. Liu, Z. Tang, G.M. Grim, A.B. Papandrew, A. Turhan, T.A. Zawodzinski, M.M. Mench, Journal of Power Sources, 206 450-453 (2012). 2. T. Jyothi Latha and S. Jayanti, J. Appl. Electrochem., 44, 995 (2014). Figure 1