Numerical Study of Electrochemical Kinetics and Mass Transport inside Nano-Structural Catalyst Layer of PEMFC Using Lattice Boltzmann Agglomeration Method

The direct modeling-based Lattice Boltzmann Agglomeration Method (LBAM) is used to explore the electrochemical kinetics and multi-scalar/multi-physics transport inside the detailed structure of the porous and catalyst layers inside polymer electrolytemembrane fuel cells (PEMFCs). The complete structure of the samples is obtained by both micro- and nano-X-ray computed tomography (CT). LBAM is able to predict the electrochemical kinetics in the nanoscale catalyst layer and investigate the electrochemical variables during cell operation. This work shows success in integrating the lattice elements into an agglomerate structure in the catalyst layer. The predictions of LBAM were compared with a macro-kinetics model and experimental data. The overall predictions reveal that the local saturation of liquid water, distributions of electrochemical variables, and mass fraction across the samples can be controlled by the regulation of operating conditions. LBAM is a highly effective method of predicting the partial flooding issue, understanding the transport resistance, and investigating transport inside the porous transport layer that affects the overall cell performance in the PEMFC. The outcome of this work will be used for the optimization of porous structure design, durability, and water management improvement, for novel porous materials, particularly in the catalyst layer. (C) The Author(s) 2019. Published by ECS.