Impact of the temperature variation on the thermal conductivity of gas diffusion layers for polymer electrolyte fuel cells

•The temperature-dependent heat transfer coefficients of different GDLs were determined.•The coating of GDL with electro-catalyst increases the heat transfer coefficient.•The increase in the temperature of the fuel cell positively affects the heat transfer coefficient.•Correlations for the heat transfer coefficient of GLDs have been proposed based on experiments. The purpose of this study is to evaluate the thermal conductivity of gas diffusion layers (GDLs) when subjected to different operating temperatures. The measurement apparatus is completely designed and the thermal conductivities are evaluated for five different GDL samples. The amount of catalyst material within the GDLs is also considered in the current study. Based on the obtained measurements, thermal conductivity correlations as a function of the operating temperature are proposed. The correlations consider a confidence interval of 95%, and according to the results, they show good predictivity. In this study, the GDL thermal conductivity coefficient functions are proposed. The mentioned correlations can be used to determine the thermal properties of fuel cells for a range of temperatures from 20 °C to 80 °C.