Effective Transport Properties Accounting for Electrochemical Reactions of Proton-Exchange Membrane Fuel Cell Catalyst Layers

Abstract

There has been a rapidly growing interest in three-dimensional microstructural reconstruction of fuel cell electrodes so as to derive more accurate descriptors of the pertinent geometric and effective transport properties. Due to the limited accessibility of experiments based reconstruction techniques, such as dual-beam focused ion beamscanning electro microscopy or micro X-Ray computed tomography, within sample micro-structures of the catalyst layers in polymer electrolyte membrane fuel cells (PEMFCs), a particle based numerical model is used in this study to reconstruct sample microstructure of the catalyst layers in PEMFCs. Then the reconstructed sample structure is converted into the computational grid using body-fitted/cut-cell based unstructured meshing technique. Finally, finite volume methods (FVM) are applied to calculate effective properties on computational sample domains.

Investigating the Performance of Catalyst Layer Micro-Structures with Different Platinum Loadings

“…The CL micro-structure was reconstructed by pseudo-randomly placing spheres of constituents phases; carbon, platinum and ionomer (6). Spheres of one constituent are overlapped so that a percolating phase is formed for the sake of transport throughout the micro-structure.…”