Contact resistance between bipolar plate and gas diffusion layer in high temperature polymer electrolyte fuel cells

• The influence of temperatures on contact resistance between BPP and GDL is studied.
• Model used to predict contact resistance between BPP and two different types of GDL.
• Higher temperature operation is found effective in lowering contact resistance values.
• Profound influence of fractional contact area of the GDL on contact resistance is found.

One of the major contributors to the ohmic loss in fuel cells originates at the interface between adjacent cell components. The compressive pressure used to achieve contact in cells should be carefully estimated to ensure that resistive losses arising from contact behavior remain minimal. In present work, a generic model is developed, capable of estimating contact resistance as a function contact pressure at the interface of graphite bipolar plate and carbon fiber based gas diffusion layer at different temperatures. A good agreement is observed between the results obtained from the model and experiments. Compressive pressure in the ranges of 3–4 MPa is found optimum for achieving low contact resistance. The contact resistance obtained for carbon paper and BPP while using recommended pressure lies between ∼9 and 4 mΩ cm2 considering the operating regime of HT-PEMFC (120–180 °C). Operating under similar conditions, the contact resistance values for carbon cloth and BPP is ∼13 to 7 mΩ cm2.