To enhance the output performance of proton exchange membrane fuel cells (PEMFCs), the design parameters of the cathode catalyst layer were optimized using an improved agglomerate model integrated into a three-dimensional, two-phase PEMFC simulation model. The model accounts for localized oxygen and proton transport resistances, enabling a more accurate evaluation of mass transport phenomena. Initially, the effects of overall Pt loading and ionomer content on cell performance were systematically investigated. Subsequently, the impact of gradient distributions of Pt loading and ionomer content along the primary flow direction, as well as their synergistic effects, was examined. Simulation results indicate that beyond a certain threshold, further increases in Pt loading do not yield performance gains, and that an optimal ionomer content exists to balance local oxygen and proton transport. Gradient distributions of Pt loading and ionomer content were found to enhance performance and improve spatial uniformity of reaction rates. When these gradients were synergistically optimized, the peak power output for PEMFC was improved by over 10% compared to uniform designs. These findings provide design guidelines for catalyst layer architecture to achieve higher performance in PEMFC applications.
 

Proton exchange membrane fuel cell, Catalyst layer, Oxygen transport, Gradient distribution