Topology optimization of the gas distribution zone uniformity in proton exchange membrane fuel cells

Flow uniformity in the cathode flow field is required for improving the performance of proton exchange membrane fuel cells (PEMFCs). In this study, a topology optimization (TO) model for optimizing the gas distribution zone (GDZ) of the cathode flow field is developed to achieve uniform flow distribution. Minimizing power dissipation is set as the objective and target flow rates are set as the constraints in the TO. A design variable mapping strategy is also introduced in the to obtain the symmetric GDZ structures, allowing for the coordinated optimization of the inlet GDZ and outlet GDZ. The TO GDZ structures under different current densities are obtained. As validated by three-dimensional (3D) simulations, significant improvement in flow uniformity is achieved by the optimized structures with streamlined short rib-like features, leading to higher output voltage compared to the typical GDZ designs. The TO is further applied to optimize the GDZ of a large-size commercial PEMFC with an active area of 288 cm². The results show that compared with the empty chamber distribution zone (ECDZ), the forced shunt distribution zone (FSDZ), and the dot matrix distribution zone (DMDZ), the flow uniformity of the topology-optimized distribution zone (TODZ) is increased by 73.21 %, 90.19 % and 88.56 %, respectively, while the net output power is raised by 1.19 %, 1.48 % and 1.34 %, respectively.