Experimental Study of Effects of Operating Conditions on Water Transport Phenomena in the Cathode of Polymer Electrolyte Membrane Fuel Cell

Water management in polymer electrolyte membrane fuel cells is important because fuel cell performance may be lower when flooding emerges. In addition, the proton conductivity and water transport coefficient in the membrane depend on the hydration of the membrane. In this study a water transport phenomenon in the cathode channels of a polymer electrolyte membrane fuel cell was investigated under various operating conditions. To obtain images of the water the transparent fuel cell had a polycarbonate window installed at the cathode end plate, and gold-coated stainless steel was used for the flow field and current collector of the cathode. The effects of operating conditions on water transport manipulated operating parameters such as cell temperature, cathode flow rate, and cathode backpressure. As the operating time elapsed, it was observed that water droplet formation, growth, coalescence, and removal occurred in the cathode channel. It concluded that a high cathode flow rate prevented flooding by removing water from the cathode flow channel. Also, the quantity of water droplets increased with a high cathode backpressure.