Identifying Contributing Degradation Phenomena in PEM Fuel Cell Membrane Electride Assemblies Via Electron Microscopy

Abstract

Advanced electron microscopy and ultramicrotomy specimen preparation techniques have been used to characterize the microstructural changes within PEM fuel cell membrane electrode assemblies (MEAs) that contribute to performance loss. Atomic- level structural and compositional analyses have been conducted on intact 3-layer MEAs before and after life-testing to identify the microstructural degradation of individual constituents comprising the MEA, i.e., carbon support, electrocatalyst, polymer membrane, and recast ionomer. Analyses conducted in this way are required to correlate observed microstructural changes with durability and fuel cell performance.