Quality Implications of Foreign Metallic Particles in the Membrane Electrode Assembly of a Fuel Cell

Abstract

Foreign metallic particles unintentionally trapped within the membrane electrode assembly (MEA) may adversely affect quality and yield of high-volume fuel cell production, for instance by damaging the membrane or releasing metallic cation contaminants. The present work aims to understand the impacts of 55 ± 5 μm Fe and SS316L metallic particles present at the membrane - cathode catalyst layer (CCL) interface during fuel cell fabrication, conditioning, and diagnostics. In-situ X-ray computed tomography imaging of particle-laden MEAs within a customized small-scale fuel cell fixture reveals that Fe particles undergo complete dissolution within the first air starve cycle of the conditioning phase. After dissolution, legacy particles are observed to incur considerable damage within the MEA, including void spaces at the membrane-CCL interface, membrane thinning, CCL cracks, and membrane rupture. In stark contrast, the SS316L particles feature negligible dissolution during fuel cell conditioning and diagnostics and remain largely intact, merely causing membrane-CCL delamination in their vicinity. Post-operation chemical analysis by laser ablation inductively coupled plasma mass spectrometry indicates Fe ion concentrations in the range of 800–950 ppm and 10–25 ppm for the Fe and SS316L laden MEAs, respectively, which correlates to visual observations of particle dissolution and slight reductions in fuel cell performance.