Adapting serpentine flow fields for application in large-scale vanadium redox flow battery cells through marginal design modifications

Abstract

Vanadium redox flow batteries are promising devices for large-scale and long duration energy storage. The independent rating of power and energy of these batteries enable customized scalability. Nevertheless; the low energy density of these systems hampering their penetration into energy market. Flow field on bipolar plate enable efficient transportation of electrolyte through electrode and increases degree of utilization of electrolyte leading to enhanced extraction of its intrinsic energy. Serpentine flow field is well-known for uniform flow distribution, however on lab-scale cells of size up to 100 cm2. In view of stack-scale requirement, the features of serpentine are explored in the cell size window of 100–2025 cm2. Studies revealed that the uniform distribution feature is retained over the cell size, however with increase in substrate flow and residence time of electrolyte species leading to reduced electrochemical performance. The proposed marginal design modifications, in the form of alternate wide and narrow channels and segmenting traverse distance of electrolyte in electrode, produced 17 % and 3 % higher energy density and energy efficiency, respectively compared to conventional serpentine. These marginal design modifications enable the translation of beneficial features of serpentine flow field in the scale-up of redox flow batteries. © 2025 Elsevier B.V.