Synergetic effect of anode and cathode flow fields on the mass transfer of large-size PEM fuel cells

For large-size proton exchange membrane (PEM) fuel cells, the flow field design is crucial for mass transfer of reactants, removal of generated water, and distribution of current density. This study evaluates the synergetic effect of anode and cathode flow fields of PEM fuel cells with an active area of 300 cm2 based on a three-plus-one-dimensional (3D + 1D) model. The mass transfer capacities of the anode and cathode flow fields with different channel shapes, rib/channel width ratios, and repeated structure units are investigated. The results indicate that the synergetic effect is an asymmetric strategy of geometric coupling and functional complementarity, where the anode provides necessary pressure gradients via inverse-phase wavy channels to support the cathode’s intensified convective structures (narrowed-channel units). Furthermore, the Shapley value is introduced to quantify the marginal contributions, identifying the repeated structure unit as the dominant factor (70.2%) for performance improvement. The optimized flow field largely improves the uniformity of current density distribution and enhances fuel cell performance by more than 3% (12 W). The proposed performance evaluation methodology provides promising alternatives for the design of high-performance commercial large-size PEM fuel cells.