Unveiling water drainage through microporous layer with laser-ablated open furrows in proton exchange membrane fuel cells

摘要

The microporous layer (MPL) in proton exchange membrane fuel cells (PEMFCs) improves the fuel cell performance remarkably. However, PEMFCs suffer from local oxygen starvation at high current densities because of the accumulation of water at the cathode. This paper presents a novel water management technique that uses open furrows with serpentine patterns in the MPL. The laser ablation technique is used to carve open furrows in the MPL, and the various properties of the furrowed MPL are characterized. To examine the effects of the furrowed MPL on water management, the polarization behavior, impedance response, and potential variation under dynamic load tests are studied experimentally and theoretically for PEMFCs with three different gas diffusion layers. The results indicate that open furrows in the MPL reduce the water saturation in the catalyst layer and increase the water discharge to the gas flow channel, thereby promoting oxygen transport to the catalyst sites.