Investigation of Gas Diffusion Layer Degradation in Polymer Electrolyte Fuel Cell Via Chemical Oxidation

Abstract

The gas diffusion layer (GDL) enables and influences the internal transport of fuel, oxygen, electricity, heat and water. The GDL is made up of the macroporous substrate and the microporous layer. To achieve the hydrophobicity required for water management, the two layers are typically treated with polytetrafluoroethylene (PTFE). Degradation of GDL, including carbon corrosion and PTFE loss, affects water management, conductivity and mass transport. GDLs were subjected to accelerated stress tests by immersing them in Fenton's reagent for 24 hours. Analysis of hydrophobic properties through contact angle measurements, thermogravimetry, and energy dispersive X-ray spectroscopy indicated that the hydrophobicity of the GDL exposed to Fenton's reagent decreased. This loss of hydrophobicity is associated with surface oxidation and PTFE degradation.