Performance analysis and experimental study of titanium GDL in proton exchange membrane fuel cell

The gas diffusion layer (GDL) plays an important role in proton exchange membrane fuel cells (PEMFC) to support the catalytic layer, collect the current, conduct the gas and discharge the reaction product water. Titanium (Ti) can be one of the choices of GDL materials due to its high strength, low density and excellent corrosion resistance. Therefore, this paper investigated Ti substrate material for GDL and comparatively analyzed the changes in the contact angle of the GDL before and after hydrophobic treatment, analyzed the changes in the performance of the cell after different treatment processes, and measured the effect of compression force on the contact resistance of the cell. The results show that, after the selection of Ti felt as the substrate and the carbon plating process, the contact angle of the substrate layer and the microporous layer increased significantly, and the hydrophobicity of the GDL surface improved after carbon plating. The contact resistance of the Ti felt substrate was significantly reduced after carbon plating and was even lower than that of the C-H-060 substrate. Considering the importance of the hydrophobicity of GDL, acetylene black microporous layer coating is also needed to increase the contact angle of the GDL interface and improve the hydrophobicity of GDL. The hydrophobic treatment of MPL using Ti felt as the substrate can significantly improve the output performance of the cell at high current density, avoid flooding inside the cell, and increase the current density operating range of the cell.