Effect of cathode channel structure on the performance of open-cathode proton exchange membrane fuel cell in dry environments

Abstract

The open-cathode proton exchange membrane fuel cell (OC-PEMFC) is a promising power supply for mobile equipment and the design of the cathode channel structure has a significant effect on its water and thermal management. In this study, a three-dimensional multifield coupled OC-PEMFC single-cell model based on a graphite bipolar plate was used to investigate the performance of three types of cathode channel designs, namely, straight, divergent, and convergent channels, under dry ambient conditions. Under ambient conditions of 10 °C and 35% relative humidity, the divergent channel design exhibits the best performance, with the highest membrane water content and uniformity, even when the ambient temperature is increased. The performance of OC-PEMFCs can be improved by increasing the cathode stoichiometric ratio (CSR) under high-temperature and dry conditions. The divergent channel design has the best output performance under various CSRs. The growth percentage of the water content in the membrane ranges from 5.3 to 8.0%, and the average temperature in the membrane is reduced by 2.78–3.47 °C. Although the performance of the convergent channel design is improved, the uniformity of the water and electricity is significantly reduced. This study also provides guidance for the design of OC-PEMFC graphite bipolar plates.