Thermal Contact Resistance Between Gas Diffusion Layer and Graphite Bipolar Plate: Modeling and Experiments

An analytic, mechanistic robust model is developed to predict the thermal contact resistance (TCR) between fibrous porous media such as GDLs and flat surfaces. The model, which accounts for the salient and realistic geometrical parameters, mechanical deformation, and thermal spreading/constriction resistances, is successfully validated with new experimental data of the TCR between GDLs and graphite bipolar plates. Several parametric studies are performed to reveal the effect of fiber specifications such waviness and also GDL properties on the TCR. For instance, it is found that, interestingly enough, fiber length does not have any effect on TCR at constant porosity. From the parametric studies, the critical values of key parameters effective on TCR are also identified, which can be very useful in GDL manufacturing and fuel cell design in viewpoint of heat management. The presented model can be readily plugged into fuel cell models for simulations and modeling purposes. Overall, the model is developed in a general form to be also applicable, with only minor modifications, to other fibrous media such as fibrous catalyst layers, metal foams, and heat exchangers.