Three-dimensional modeling study of all-vanadium redox flow batteries with the serpentine and interdigitated flow fields

• A comprehensive 3-D VRFB model with different flow fields is proposed. • The SFF with smaller channel and rib widths enhances the mass transfer in the carbon paper electrodes. • The performance of the carbon paper-based VRFBs is more sensitive to channel width than rib width. A comprehensive three-dimensional (3-D) model is developed to study the performance of all-vanadium redox flow batteries (VRFBs) with both serpentine flow field (SFF) and interdigitated flow field (IFF) by using 9 cm 2 carbon paper electrodes. Thanks to the induced stronger electrolyte convection in the electrodes, the batteries with SFF have better performance than IFF, though SFF may cause a higher pressure drop, especially at high flow rates. The effect of flow field geometry of SFF on the battery performance is further studied. Decreasing the channel depth of SFF enhances the mass transfer of electrolytes in the electrode, and the battery performance is more sensitive to the change of channel depth at high current densities. In addition, the battery performance declines with the increase of SFF channel width and rib width, and the influence of channel width is more pronounced than that of rib width. Reducing the rib width increases the electrolyte convection in the electrode more evidently for SFF with a wider channel while avoiding an excessive increase in pressure drop. Therefore, in the case of high current density or low electrolyte flow rate, the SFF with small flow channel depth and small rib width is conducive to improving the performance of VRFBs.