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Gas diffusion layers (GDLs) coated with a hydrophobic microporous layer (MPL) have been commonly used to improve the water management properties of polymer electrolyte fuel cells (PEFCs). In the present study, a new hydrophilic and hydrophobic double MPL coated GDL was developed to achieve further enhancement of PEFC performance under both low and high humidity conditions. For the double MPL coated GDLs, the hydrophilic layers using either PVA (polyvinyl alcohol) or TiO 2 were coated on the hydrophobic MPL coated GDL. Under low humidity, the double MPLs with the hydrophilic layers using both PVA and TiO 2 are effective for conserving humidity at the catalyst layer, thereby enhancing PEFC performance. Under high humidity, because hydrophilicity of the hydrophilic layer using PVA is too high, PEFC performance is deteriorated due to flooding. However, the appropriate hydrophilic layer using TiO 2 is effective for reducing flooding, thereby enhancing PEFC performance.

No abstract

Gas diffusion layers (GDLs) coated with a hydrophobic microporous layer (MPL) have been commonly used to improve water management properties of polymer electrolyte fuel cells (PEFCs). In the present study, a novel hydrophilic and hydrophobic double MPL coated GDL was developed to further enhance the PEFC performance under both low and high humidity conditions. Under low humidity conditions, a thin hydrophilic layer using titanium dioxide coated on the hydrophobic MPL is effective to conserve the humidity of the MEA, while a hydrophobic intermediate MPL between the hydrophilic layer and the GDL substrate prevents the removal of water in the hydrophilic layer. Under high humidity conditions, a double MPL coated GDL is also effective to reduce flooding on the cathode catalyst layer, which results in a higher PEFC performance compared with that for a conventional hydrophobic MPL coated GDL.

No abstract