Analytical calculation and evaluation of water transport through a proton exchange membrane fuel cell based on a one-dimensional model

摘要

A one-dimensional model accounting for chief water transport phenomena in proton exchange membrane (PEM) fuel cell is developed. The water transfer process in catalyst layers (membrane water absorption/desorption) is explicitly taken into account and the mathematical descriptions of the Schroeder's paradox are presented in this model. In addition, to solve two-phase problems in gas diffusion layers (GDLs) without using complex numerical approach, the assumption of an infinite phase change rate is applied and the analytical solutions to the two-phase model equations are derived. Based on the model and the analytical solutions, an identification procedure using the iterative approach is proposed to (1) determine the net water flux through the membrane, (2) obtain exact water profiles in all components of PEM fuel cell and (3) predict the dehydration and flooding. The AC impedance technique is used to analyze the cell performance and the predicting capability of the model-based approach is validated. The measurements and predictions both reveal the effect of electro-osmotic drag on drying the anode at high current and the trade-off between membrane dehydration and water flooding in the cell. (C) 2016 Elsevier Ltd. All rights reserved.