Measurements of Water Vapor and Current Distributions and Prediction of Water Crossover in PEMFC under Low-Humidity Conditions

Abstract

In order to alleviate membrane dryout in proton exchange membrane fuel cells (PEMFCs) under low-humidity conditions, it is necessary to understand water transport between anode and cathode. In this study, the water vapor distribution within the anode gas channel of a low-humidity PEMFC was quantitatively evaluated by using humidity test paper (HTP), and the effects of inlet gas humidification and micro-porous layer (MPL) addition were investigated. In addition, the distribution of the hydrogen flow rate was calculated based on the current distribution measurement, and the local water crossover in the PEM was numerically predicted. It was noted that the MPL addition on the cathode side promotes the back-diffusion of product water at the low-humidity anode inlet of the co-flow serpentine flow field.