Abstract
To alleviate membrane dryout in PEFCs under low-humidity operation, it is essential to understand and control water crossover through electrolyte membrane. This paper presented a novel method for quantitatively measuring the water vapor distribution in the gas channel of a low-humidity PEFC using humidity test paper (HTP), and investigated the effects of stoichiometry and gas humidification on the water transport in the anode. Furthermore, the flow distributions of hydrogen and water vapor on the anode side were estimated based on current distribution measurement, and the local water transport coefficient through the membrane was numerically predicted. It was found that the low stoichimetric cathode flow enhances the back-diffusion of product water across the membrane, and suppresses the membrane dehydration.
