Effect of interfacial phenomena at the gas diffusion layer-channel interface on the water evolution in a PEMFC

We analyze the impact of the interfacial phenomena at the macroscopic interfaces between fuel cell components on the water management and on the two-phase transport in proton exchange membrane fuel cell (PEMFC) electrodes using multiphase multifluid computational fluid dynamics. We present the physical and the mathematical models and the numerical approach used to capture multiphase phenomena at the cathode gas diffusion layer-channel interface and explain the mechanisms that trigger the phenomenon referred to as the "eruptive water ejection." Notwithstanding that they have been widely ignored, these are phenomena which ultimately control the amount and the spatiotemporal behavior of water in the fuel cell components during operation. This analysis lays the groundwork for subsequent studies of fuel cell performance variations caused by manufacturing tolerances and defects in the porous electrode at the interface with the channel. It also provides insight for designing diffusion media with controlled structural properties at the interface with the channel, such as pore-size distribution or pattern of orifices punctured during the fabrication process.