Simulation of a three-dimensional PEM fuel cell cathode using a catalyst agglomerate model

'Full text:' The catalyst layer is the heart of a fuel cell, however, a majority of three-dimensional (3-D) computational fluid dynamics (CFD) models for PEM fuel cells treat the catalyst layer simplistically using a thin-layer approximation. A 2-D agglomerate-type catalyst layer model developed in our group has shown that both electron and oxygen transport within the catalyst layer play an important role in determining the location and the rate at which reaction occurs. However, this model does not fully account for transport processes. A comprehensive 3-D CFD-based model framework for PEMFCs is also being developed in our group. In this work, the 2-D agglomerate model is combined with the 3-D PEMFC model to simulate the physico-electro-chemical processes occurring in the cathode half cell of a PEMFC. The transport of both the charged (electron and ions) and chemical species is considered in the catalyst layer. The computational domain includes a single-serpentine channel, the gas diffusion layer and the catalyst layer. The 3-D model allows simulation of convective and diffusive transport in the porous GDL and catalyst layer. A key objective of the study is to compare simulation results for the catalyst layer treated as a thin-film and as an agglomerate. (author)