Evaluation of Membrane Electrode Assembly Materials for High-Temperature Proton Exchange Membrane Fuel Cells

摘要

The cell performances of three commercial high-temperature MEAs (membrane-electrode assemblies) based on phosphoric acid-doped polymer membranes (PBI, ABPBI, Pyridine) were studied in the temperature range of 120～190 °C without humidification. These MEAs have a five-layer structure with an active area of 25 cm~2. The results of the cell performance tests indicated that the best operating temperature was between 180 °C and 190 °C. The maximum output power density was obtained in the voltage range of 0.45～0.5 V. The cell current densities of these MEAs under the conditions of 180 °C, 0.6 V, and H_2/air, were 215 mA/cm~2, 380 mA/cm~2, and 370 mA/cm~2. From the electrochemical impedance spectroscopy (EIS) analysis, we found that the charge transfer resistance and the cell internal resistance were decreased as the cell temperature increased. These MEAs can reach steady state after a 24-hour activation process, as indicated from the current-voltage polarization curve. The best cell assembly pressure was 60 kgf-cm, which can provide good performance and sealing of the cell. The cell current-voltage curve was not affected by using gaskets of different thicknesses (300 μm and 500 μm).