Abstract
The durability and efficiency of proton exchange membrane (PEM) fuel cell must meet the demanding requirements before its commercialization. Based on this consideration, the chronological acidity change of proton exchange membrane fuel cell (PEMFC) water and the corrosion of aluminum bipolar plate are investigated in this paper. Two operating factors, cell temperature and fuel gas temperature, and two temperature levels, i.e., 30°C and 90°C, are designed for the experiments. The fully humidified feeding flows rates are oxygen gas (140 sccm) at the cathode side and hydrogen gas (210 sccm) at the anode side. The constant current density test is set to 1200 mA/cm2. Characteristics of product water that drained from the PEMFC cathode outlet are measured by a pH meter in a real-time process. The chronological water acidity varied case by case, and its pH value ranged from 3.5 to 7. Abundant free radicals formed easily when the cell temperature is operated at 90°C, and it enhances the acidity of PEMFC water. The microstructure of the corrosive surface is also observed by a scanning electron microscope (JSM series model number 6500F, JEOL Inc.) equipped with an energy dispersive X-ray spectroscopy (EDAX) system.