Abstract:The flow field structure of proton exchange membrane fuel cells (PEMFCs) plays a critical role in regulating reactant transport, heat dissipation, and electrochemical reactions. To address challenges commonly observed in conventional flow channels, such as non-uniform reactant distribution, insufficient liquid water management and limited output performance, three types of lattice flow fields were newly designed. Three-dimensional PEMFC models featuring both traditional parallel and lattice-type flow fields was established, and their output performance, oxygen transport resistance, oxygen molar concentration uniformity, oxygen distribution, and liquid water saturation were comparatively analyzed. Results show that, compared with the traditional parallel flow field, all three lattice designs exhibited improved performance, achieving a maximum increase of 24.74% in peak power density. The lattice flow fields also demonstrated significantly lower oxygen transport resistance, higher oxygen concentration uniformity, and enhanced internal oxygen distribution and liquid water management. These findings provides a promising direction for innovative PEMFC flow filed design.