Water and hydrogen transport modelling through the membrane-electrode assembly of a PEM fuel cell

Membrane electrode assembly (MEA) formed by a proton exchange membrane (PEM), two catalyst layers and two gas diffusion layers represent the heart of the PEM fuel cell system, being the place where the electrochemical reactions are developed in order to generate electrical power. Due to a complex water production and transportation process through the porous media of MEA, the water management represents one of the most critical issues for the low temperature PEM fuel cell systems, working at 30 degrees C-80 degrees C. In the present paper, a one-dimensional mass transport PEMFC model for evaluation of net water flux across the Nafion type membrane was implemented with the Comsol Multiphysis software, based on the finite element method. Hydrogen crossover phenomenon, which may cause a degradation of the reaction sites inside MEA, was also included in the model. The numerical model offered a reasonable prediction of the fuel cell electrical performance in the form of current-voltage characteristic after validation with experimental data from the literature. Fuel cell performance was investigated by modifying the temperature and pressure inside the cell, along with the relative humidity for reactant gases.