Numerical simulation of liquid water transport in ordered microstructures gas diffusion layer of proton exchange membrane fuel cell

The performance of the gas diffusion layer (GDL) plays a pivotal role in ensuring the efficient and stable operation of proton exchange membrane fuel cells (PEMFCs). Microstructure of the GDL significantly influences its internal water transport capabilities. In this article, the lattice array method is employed to construct ordered microstructures within GDLs, followed by the utilization of phase field method to numerically simulate water transport among these structures. The effects of lattice edge length, lattice height, and lattice shape on water transport throughout the GDL are investigated. The results reveal that excessively large or small lattice edge lengths detrimentally affect effective water transport within the GDL. Additionally, a smaller lattice height can accelerate the breakthrough of liquid water through the GDL. Notably, when the lattice height is smaller than the lattice edge length, it enhances the mass transfer. Moreover, the triangular lattice impedes the water flow, while the rectangular structure diminishes the transmission efficiency of liquid water. In contrast, hexagonal and octagonal structures exhibit the ability to alleviate the transport resistance of liquid water, with the octagonal lattice demonstrating superior mass transfer effectiveness. These findings underscore the paramount importance of meticulous structural design in further augmenting the mass transfer performance of ordered GDLs. The research provides meaningful guidance for the design of GDL structures.