Measurement Technique of Effective Oxygen Diffusion-Coefficient of Water-Containing Gas Diffusion Layers

An effective oxygen diffusion-coefficient in gas diffusion layer (GDL) is critical for improving the performance of polymer electrolyte fuel cell (PEFC). Effective oxygen diffusion-coefficient of GDL decreases with increasing water saturation, and it leads to a drop in performance. Therefore, we developed a measuring technique for effective oxygen diffusion- coefficient of water-containing GDL. Saturation was measured through a sample weight change in the drying process. Using this technique we elucidated the relationship between effective oxygen diffusion-coefficient and water saturation in GDL. As a result, it was verified that the amount of decrease in effective oxygen diffusion-coefficient with water saturation is based on GDL hydrophobicity.