• Ihonen, J.
• Sousa, Jm
• Perez, Lc
• Mendes, Adélio

Abstract

Adequate water management is crucial to increase stability and durability of Polymer Electrolyte Membrane Fuel Cells. In this paper, a test rig suitable for water balance and nitrogen crossover studies was built around a hydrogen-air segmented cell and used to indirectly assess flooding or drying conditions in specific zones of the active cell area. In particular, the anode of the segmented cell was operated in recirculation mode with continuous water removal. Current density distribution (CDD) diagrams were obtained for different anode operating parameters, namely, the recirculated gas flow rate, anode pressure, and time between purges. Water accumulation at the electrodes was assessed from CDD diagrams and confirmed using water balance and flow-patterns calculations. It was concluded that lower recirculation flow rates led to flooding due to decreased water removal capabilities at the anode. For higher recirculation flow rates, drying was observed in one zone of the cell but homogeneous CDD in the other. Finally, the use of partially segment bipolar plates was proposed to increase the in-plane electrical resistance between adjacent segments. The partial segmentation increased the segment to segment in-plane electrical resistance between 14 and 21% and decreased the through-plane to in-plane resistance ratio by 17%.

Topics

• density
• impedance spectroscopy
• polymer
• Nitrogen
• Hydrogen
• current density
• durability
• drying