MEA FABRICATION USED IN PROTON EXCHANGE MEMBRANE FUEL CELL FUELED BY HYDROGEN

摘要

MEA (Membrane Electrode Assembly) is a heart of the PEMFC (Proton Exchange Membrane Fuel Cell) fueled by hydrogen gas. MEA generally made by hot pressing method was the main focus of this research. The hotpressing parameters involved with pressure, time and temperature are key parameters for MEA fabrication since it can minimize the main losses along the MEA components and interfaces. Screening significant factors in the method done by full factorial design under fixed conditions of 500 and 1500 psi., 2 and 5 min. and 100 and 160 ℃ was selected. The PEMFC made of these MEAs were tested under atmospheric pressure at 70 ℃ and 150 ml.min-1 each for hydrogen gas at anode and oxygen gas at cathode. Hot-pressing conditions affected the cell performance in terms of current density and power density. Sequentially, temperature, pressure and time are significant parameters. Excess hot-pressing temperature decreased the exchange current density, io because the active layer was extremely embedded into the electrolyte membrane. The values of io of eight MEAs fabricated was varied in a wide range between 0.1×10-3 and 0.011 mA.cm-2. A high hot-pressing temperature and pressure condition significantly influenced the ohmic which is caused by high internal resistance. The average internal resistance was 1.325 and 2.581 Ω.cm2 for 500 and 1500 psi., respectively.