In situ investigation of proton exchange membrane fuel cell performance with novel segmented cell design and a two-phase flow model

A novel segmented fuel cell device based on the multi-layered printed circuit board (PCB) flow field plates is designed to study the localized fuel cell performance with various operation conditions. With embedded sensors, distributions of current density, relative humidity (RH) and temperature for both anode and cathode are measured simultaneously along the direction of straight parallel flow channels. Meanwhile, a stationary two-phase flow fuel cell model is developed to study the internal reaction parameter distributions and the results are compared with the in situ experimental measurements. In the co-flow operation mode of hydrogen and air, current density and reactants' RH distributions are sensitive to the stoichiometry of air but the effect from hydrogen is minor. Water transfer behavior, local reactants' RH status, temperature gradients and their impacts on current distributions are analyzed based on the in situ measurements and the coupled model analysis. The segmented cell device discussed in this paper, as well as the experimental and modeling results can be employed to optimize stack design and operating parameters with “visible” internal distributions of water, RH and temperature inside membrane electrode assembly (MEA). Further investigation on fuel cell performance and lifetime with different reactant flow directions is also suggested.