Effects of fabrication parameters of membrane–electrode assembly for high-performance anion exchange membrane fuel cells

Abstract

High-performance membrane–electrode assemblies (MEAs) are required for anion exchange membrane fuel cells (AEMFCs). In this study, we investigated different electrode coating methods and the effect of the ionomer/carbon (I/C) ratio to determine a suitable method for use with different anion exchange membranes (AEMs). The MEAs were manufactured by spray coating using catalyst-coated substrate (CCS) and catalyst-coated membrane (CCM) methods. By controlling the I/C ratio in the electrode, a reduction in the ohmic resistance was possible due to changes in the ionic path at the membrane–electrode interface, which affected the electrode morphology. In particular, for the CCS method, the ohmic resistance can be reduced by increasing the I/C ratio, whereas, for the CCM method, which yields a relatively low ohmic resistance, the I/C ratio has a greater effect on the electrode morphology than the resistance at the membrane/electrode interface, thus improving AEMFC performance. Finally, MEAs were fabricated from four commercially available AEMs using CCS and CCM, and the choice of method was found to be dependent on the properties of the AEMs. Overall, selecting a fabrication method optimized for the MEA requires understanding the electrode and AEM properties.