Thermal conductivity and contact resistance of compressed gas diffusion layer of PEM fuel cell

Abstract

This paper discusses the effect of compression pressure on the mechanical and thermal properties of gas diffusion layers (GDL). The stress-strain curve of the GDL revealed one nonlinear and two piecewise linear regions within the compression pressure range of 0 to 5.5 MPa. The thermal conductivity of the compressed GDL was found to be independent of the compression pressure and was determined to be 1.18 ± 0.11 W m-1 K-1. The thermal contact resistance between the GDL and graphite was evaluated by augmenting experiments with computer modeling. The thermal contact resistance decreased nonlinearly with increasing compression pressure. According to results here, the thermal bulk resistance of the GDL is comparable to the thermal contact resistance between the GDL and graphite. A simple one dimensional model predicted a temperature drop of 1.7-4.4 °C across the GDL and catalyst layer depending on compression pressures.