Blocked serpentine flow field with enhanced species transport and improved flow distribution for vanadium redox flow battery

Abstract

A blocked serpentine flow field is proposed for vanadium redox flow battery (VRFB) in order to improve electrolyte penetration and convection in the porous electrode such that the overall battery performance can be boosted. A three-dimensional mathematical model with considering non-uniform electrode structure under compression and electrode intrusion into channels was applied for simulating and comparing the VRFB performance with conventional serpentine flow field and blocked serpentine flow field. It was indicated that for blocked serpentine flow field, with increasing the block height from 0 mm to 1.5 mm, the discharge voltage of the battery is obviously boosted due to the enhanced species transport and improved flow distribution in the porous electrode. Also, it was shown that the overall battery performance in terms of net discharge power and system efficiency reaches maximum for the blocked serpentine flow field with 1.4 mm block height among different flow field designs, which is attributed to the tradeoff between the effects of increased pump loss and the improved charge-discharge performance. This study can provide beneficial advice for designing the suitable flow field for VRFB with improved mass transport performance.