Enhancing Vanadium Redox Flow Battery Performance through Optimized Flow Field with Rib-Induced Forced Convection: A Numerical Investigation

The flow field is an essential component of the vanadium redox flow battery (VRFB), and its reasonable dimensions critically impact the cell’s performance. Therefore, this work innovatively investigates the effects of uniformly varying the width and depth of the flow channel while keeping the cross-sectional area constant on the performance of the cell. The study examines the influence of different geometries on electrolyte flow uniformity, concentration gradient, and under-rib convection. The results show that the best cell performance, the lowest pump power, and the highest power-based voltage efficiency are achieved when the channel width was 1.2 mm and the diagonal is 1.46 mm. Under a current density of 80 mA cm-2 and flow rates of 120 mL min-1 and 180 mL min-1, the voltage efficiency reaches a maximum of 91.53% and 92.34%. Additionally, this work proposes an empirical formula that combines geometrical parameters and performance indices to describe the intrinsic reasons for the performance variations. This formula can predict and optimize the flow field design, and its validity is verified by experimental data. The study provides a theoretical reference for the optimization of VRFB flow field structures.