Cathode and interdigitated air distributor geometry optimization in polymer electrolyte membrane (PEM) fuel cells

A steady-state single-phase three-dimensional electro-chemical model is combined with a nonlinear constrained optimization procedure to maximize the performance of the cathode and the interdigitated air distributor in a polymer electrolyte membrane (PEM) fuel cell. The cathode and the interdigitated air distributor design parameters considered include: the cathode thickness, the thickness of the interdigitated air distributor channels and the width of the interdigitated air distributor channels. A statistical sensitivity analysis is used to determine robustness of the optimal PEM fuel cell design. The results of the optimization analysis show that higher current densities at the membrane/cathode interface are obtained in the PEM cathode and the interdigitated air distributor geometries that promote convective oxygen transport to the membrane/cathode interface and reduce the thickness of the boundary diffusion layer at the same interface. The statistical sensitivity analysis results show that, while the predicted average current density at the membrane/cathode interface is affected by uncertainties in a number of model parameters, the optimal designs of the PEM cathode and the interdigitated air distributor are quite robust.