The study of transient phenomena in Proton Exchange Membrane Fuel Cells (PEMFCs) is critical for enhancing their performance and longevity. This research focuses on the intricate dynamics of water management and membrane resistance, which are pivotal factors influencing both the aging process and operational efficiency of PEMFCs. As fuel cell technology continues to evolve, understanding the transient behavior during varying operational conditions becomes essential for optimizing performance and extending the lifespan of these systems.In this study, we systematically investigate the effects of humidity on the transient response of segmented PEMFCs under co- and counterflow. Humidity plays a dual role in PEMFC operation; while adequate hydration is necessary for optimal ionic conductivity and a low membrane resistance, excessive water can lead to flooding of porous media, adversely affecting performance. This effect is exacerbated by the presence of highly varying humidity levels along the channel, potentially leading to both phenomena, occurring simultaneously but at different positions within the cell. Insufficient humidity can result in membrane dehydration, increasing membrane resistance and leading to performance degradation. By analyzing these competing effects, we aim to elucidate proper operating conditions for sufficient balance of water management.
Wimmer et al. (Mon,) studied this question.