Analytical model for PEM fuel cells including water transport and implications for improving the MEA structure

摘要

This paper presents a method for calculating the relative effectiveness of each mass transfer processes in the PEM fuel cell electrode. Such a method is useful for improving the existing design of an MEA and for determining the feasibility of a new electrode material or design. The method was applied to MEAs fabricated in our laboratory and found ionic conductivity in the membrane and electrode dominating the transport losses in the cell. Since conductivity is a function of the water content in the electrolyte, MBA structures fabricated in our laboratory with substrate layers designed to increase the water content in the electrolyte showed significant improvement. These new MEA structures not only improved performance while operating humidified, but also while operating with a dry gas feed.