Steady-state and dynamic performance characteristics of proton exchange membrane fuel cell with dual-gradient platinum distribution in the catalyst layer

Enhancing steady-state and dynamic response performance is crucial for vehicle-mounted Proton Exchange Membrane Fuel Cell (PEMFC) durability applications. In this study, a three-dimensional, two-phase, non-isothermal, transient multi-physics PEMFC model is developed incorporating an agglomerate sub-model for cathode catalyst layer (CCL). The goal is to examine the tailored gradient CCL design on steady-state and dynamic characteristic of PEMFC with different platinum (Pt) gradient distribution in through-plane and in-plane directions. The results indicate that the maximum output power density is, respectively, improved by 5.04 %, 3.06 %, and 3.96 % with increasing Pt-loading near the membrane side, near the channel outlet side and the dual-gradient distribution compared with uniform Pt distribution, whereas the configuration increasing Pt-loading near the membrane side exhibits poor local current density uniformity. Moreover, when the load is abruptly increased under dynamic conditions, the voltage undershoot is decreased by 2.3 % and 1.84 % for increasing Pt-loading near the membrane side and the dual-gradient distribution, respectively. Besides, it is indicated that the dual-gradient Pt-loading distribution can achieve 42.4 % improvement in local current density uniformity index after loading as compared with increasing Pt-loading near the membrane side configuration. This implies that the dual-gradient Pt-loading design has significant potential to enhance dynamic response performance of PEMFC.