Effects of electrode compression on the water droplet removal from proton exchange membrane fuel cells

摘要

Proton-exchange membrane (PEM) fuel cells are one of the main candidates for propulsion systems of modern electric vehicles. However, appropriate water management is crucial to performance. Cell compression can affect the performance and water management of PEM fuel cells. Although the influence of cell compression on the transport of continuous water flow through the porous electrodes has been investigated, the influence of cell compression on the droplet dynamic behavior through these electrodes is not investigated thoroughly. Employing a pore-scale simulation method such as lattice Boltzmann method (LBM) is an excellent means for such investigation. In this study, LBM was applied to investigate the influence of compression of gas diffusion layer (GDL) on the removal of a water droplet from an electrode of a cell with interdigitated flow field. During removal process the droplet dynamic movement through five different GDLs (one without compression and the other four with four different levels of compression) was depicted and analyzed. The results reveal that the droplet experiences a faster removal process when the GDL is compressed. However, more increasing of compression does not result in a faster removal process, which indicates the existence of an optimum compression level for which the fastest removal process occurs.