Effect of micro-cracks on the in-plane electronic conductivity of proton exchange membrane fuel cell catalyst layers based on lattice Boltzmann method

Micro-cracks commonly occur on the catalyst layers (CLs) during the manufacturing of catalyst coated membranes (CCMs). However, the crack shape parameters effect on CLs in -plane (IP) electronic conductivity As is not clear. In this work, the relationship between crack parameters and the As is obtained based on the two-dimensional (2D) multiple -relaxation time (MRT) lattice Boltzmann method (LBM). The LBM numerical model is validated by the normalized As experiment applied on three different home-made cracked CLs, and the parameter study focus on crack width, length, quantity and phase angle are carried out. The results show that the decrease of As has different sensitivity |k| to the parameters above. The crack width has little effect on As decrease, and the |kw| is 0.038. However, crack arm length and quantity show more significant impact, which |kl| and |kN| are 0.753 and 0.725, respectively. The CLs with different crack propagation directions show significant anisotropy on As, and a 53.53% decrease in As is observed between 0 degrees and 90 degrees crack phase angle change. To manufacture a high electronic conductivity CL, crack initi-ation and migration mitigation are highly encouraged.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.