Applying the Generalized Stefan-Maxwell Equations to Ion and Water Transport in the Polymer Electrolyte of a PEM Fuel Cell

Abstract

Ion and water transport phenomena in the polymer electrolyte plays a significant role in the energy conversion process of a polymer electrolyte membrane (PEM) fuel cell. A mathematical model for ion and water transport in the polymer electrolyte is presented, based on non-equilibrium thermodynamics and the Generalized Stefan-Maxwell equations. The physical constants of the model, such as the binary diffusion coefficients of the Generalized Stefan-Maxwell equations, are obtained from published, experimental data for membrane water diffusion and conductivity. The electrolyte transport model is incorporated into a model of an entire PEM fuel cell; water transport in the electrolyte and gas phase are coupled and solved in a single domain.