Effective protonic and electronic conductivity of the catalyst layers in proton exchange membrane fuel cells

The effective protonic and electronic conductivity of the catalyst layers in proton exchange membrane fuel cells has been investigated using a numerical model derived from the random packed spheres with simple cubic, body-centered cubic and face-centered cubic structures. A correlation equation of the effective conductivity is obtained. The model has been validated by the agreement between the simulation and the experimental. The relationships between porosity and the effective conductivity and influences of temperature and water activity on the effective protonic conductivity of the catalyst layers are presented which demonstrate the broad applicability of this model. (C) 2004 Elsevier B.V. All rights reserved.