Effect of gas pressure and clamping pressure on interfacial contact resistance of a cylindrical polymer electrolyte membrane fuel cell

ABSTRACT Cylindrical polymer electrolyte membrane fuel cells are promising energy conversion devices for next generation transportation applications because of their high volumetric and gravimetric power densities. The present study is focused to evaluate the effect of a design parameter (clamping pressure) and an operational parameter (gas pressure) on the contact resistance of the cell. The cell is modelled to visualise contact pressure at the interface of the gas diffusion layer and the current collector. It is observed that the contact pressure at the interface is dependent on both clamping as well as gas pressure. The ohmic resistance of the cell is found to decrease with increase in current, reaches a minimum and then increases owing to membrane hydration and dehydration over gradual increase in the cell temperature. The threshold contact resistance is then calculated to be 33.21 mΩ cm2 based on the minimum ohmic resistance of 100 mΩ. The study highlights the optimum zone where the combination of both clamping and gas pressures can be used to minimise the contact resistance.