Scaling factors for channel width variations in tree-like flow field patterns for polymer electrolyte membrane fuel cells - An experimental study

To have a uniform distribution of reactants is an advantage to fuel cell. We report results for such distributor with tree-like flow field plates (FFP). Numerical simulations shown that the width scaling parameters patterns in FFPs used polymer electrolyte membrane cells (PEMFC) reduces viscous dissipation channels. In this study, experimental investigations were conducted on 2-layer FF plate possessing pattern which was CNC milled high-quality graphite. Three designs different employed. I–V curves, power curves and impedance spectra generated at 70%, 60% 50% relative humidity (25 cm2 active area), compared those obtained from conventional 1-channel serpentine FF. It found design, factor 0.917 inlet 0.925 outlet pattern, exhibited best peak out three (only 11% - 0.08 W/cm2 lower than reference FF). Results showed reduction not directly linked PEMFC performance increase. water accumulation, together slight increase single resistance, main reasons reduced density. As further improvements, number branching generation levels recommended.