Characterization and scale-up of serpentine and interdigitated flow fields for application in commercial vanadium redox flow batteries

Abstract

Vanadium redox flow batteries constitute a promising option in the field of stationary energy storage especially with respect to long-duration and large-scale duty scenarios. Indeed, although having numerous beneficial characteristics in the design and operation of vanadium redox flow batteries, their low power density is hindering their penetration into the energy storage market. Flow-field design and flow rate optimization are effective ways to improve battery power density. There are numerous studies in published literature on serpentine and interdigitated flow fields with deeper flow channels on thick bipolar plates. This paper deliberates the characterization of laboratory cells of size 100 cm2 equipped with serpentine and interdigitated flow fields on thin bipolar plates which generally employ in commercial stacks. The experimental results of charge-discharge life cycles and polarization measurements have been interpreted with the help of computational fluid dynamics simulations. The simulations are then extended to a cell size of 625 cm2. The results revealed an interesting characteristic on the variability of geometrical scale-up in each flow-field to obtain desired electrolyte distribution at minimal pressure drop.