Speaker
Description
The increasing environmental pollution problem has been attributed to fossil fuels, prompting a high demand for effective replacements. Proton exchange membrane fuel cells (PEMFCs) are a crucial technology for producing electric power in many applications that utilize hydrogen to generate high-efficiency and low-emission electricity. To improve the utilization of supplied gases, dead-end operations have been employed both on the cathode and anode sides of a fuel cell system; however, in dead-end operations, impurities may accumulate and cause the catalyst layer to degrade. In this study, both the anode and cathode of an H$_2$/O$_2$ PEMFC are operated in a dead-end mode. The cell is operated at 800 mA/cm$^2$ and 70°C under various cathode gas humidifying conditions. The anode is purged at selected current integral values of 5000 As and 10000 As, whereas the cathode is purged at 1400 As. The polarization curve, impedance, and morphology of the catalyst layer are investigated after long-term operation (24 and 48 h). The results indicate that the performance of the single cell deteriorates significantly under dry cathode conditions compared to 50%RH. The minimum degradation rates observed with humidify on the cathode side were 0.059 and 0.076 V/h, respectively, with an anode current integral of 5000 As and 10000 As. Furthermore, the thickness of the cathode catalyst layer decreased by 50% after 48 hours of operation.
