Impact of PTFE distribution across the GDL on the water droplet removal from a PEM fuel cell electrode containing binder

By progress of the new generation of electrical powertrains and reducing of the fossil fuel resources, vehicle industry becomes more interested in utilizing proton exchange membrane (PEM) fuel cells. However, practical utilization of them is faced with some challenges including liquid water accumulation in the porous electrodes. The common belief for mitigating this issue is the treatment of electrodes' gas diffusion layers (such as carbon papers consisting of carbon fibers and binder for binding fibers) with a highly hydrophobic material such as poly-tetra-fluoro-ethylene (PTFE). In the current investigation, 3D stochastic reconstructions and 3D lattice Boltzmann simulations are employed to discover the impact of PTFE distribution as well as the role of binder content on the removal process of a water droplet from a PEM fuel cell electrode for the first time. Nine different simulations with three dissimilar PTFE distributions and three dissimilar binder contents are implemented. The results demonstrate that the PTFE distribution and the existence of binder can greatly affect the removal efficiency of water droplet from gas diffusion layer. Unexpectedly, for higher binder contents, the uniform distribution of PTFE is less effective. Besides, for a specific PTFE distribution adding binder can effectively hinder the removal process of droplet. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.