Effect of PTFE on Thermal Conductivity of Gas Diffusion Layers of PEM Fuel Cells

Through-plane thermal conductivity of 14 SIGRACET gas diffusion layers (GDLs), including series 24 & 34, as well as 25 & 35, are measured under different compressive pressures, ranging from 2 to 14 bar, at the temperature of around 60 °C. The effect of compression, PTFE loadings, and micro porous layer (MPL) on thermal conductivity of the GDLs and their contact resistance with an iron clamping surface is experimentally investigated. The contact resistance of MPL coated on GDL with the substrate of that GDL is measured for the first time in this paper. A new robust mechanistic model is presented for predicting the through-plane thermal conductivity of GDLs treated with PTFE and is successfully verified with the present experimental data. The model can predict the experimentally-observed reduction in thermal conductivity as a result of PTFE treatment and provides detailed insights on performance modeling of PEMFCs.