A bifurcate interdigitated flow field with high performance but significantly reduced pumping work for scale-up of redox flow batteries

Designing flow fields that can uniformly distribute electrolytes while maintain a low pumping work is challenging for high-performance redox flow batteries, especially for scaled-up battery stacks. In this work, we propose a bifurcate interdigitated flow field, which hierarchically splits the electrolyte and transports it into branch channels, thereby lowering the pumping loss and enhancing the uniformity of electrolyte distribution. The application of the flow field to a vanadium redox flow battery reduces the pressure drop by 45%, thereby increasing the pump-based voltage efficiency from 69.95% to 73.10% compared to that with conventional interdigitated flow field at a flow rate of 2.4 mL min−1 cm−2 and current density of 250 mA cm−2. Furthermore, three-dimensional modeling reveals that the superiority of reducing the pumping loss becomes more extraordinary with the enlargement of active area, indicating that the bifurcate interdigitated flow field shows great potential for the scale-up of high-performance flow batteries with a low pumping work.