Chemo-mechanical durability of reinforced fuel cell membranes in the presence of metallic foreign particles: Part 1 – effect of chemical composition

This work is the first part of a three-part article series investigating the impact of incidentally deposited metallic foreign particles within the membrane electrode assembly (MEA), which could originate from industrial machinery used in the production processes. It is hypothesized that such metallic particles may reduce the fuel cell durability by releasing contaminants and/or inflicting physical damage. The present work (Part 1) therefore focuses on understanding the impact of Fe and stainless steel 316L (SS316L) particles of nominal size (55 ± 5 μm) on the chemo-mechanical membrane durability in fuel cells. In-situ morphological characterization using X-ray computed tomography of a miniaturized fuel cell with Fe particle-laden MEA reveals complete particle dissolution, ∼90% global membrane thinning, and hydrogen crossover failure after accelerated stress testing. Additionally, post-mortem chemical quantification by laser ablation inductively coupled plasma mass spectrometry reveals a uniform Fe ion concentration of 40-190 ppm across the active area, indicating a catalytic effect for chemical membrane degradation. In contrast, the corresponding test of an SS316L particle-laden MEA shows merely partial dissolution and local membrane thinning near the particles without failure, accompanied by high local Fe ion concentration of 350 ppm near the particles and low 25 ppm concentration elsewhere, suggesting more benign impact. • The impact of metallic particles on reinforced membrane durability is evaluated. • 4D in-situ XCT reveals rapid Fe particle dissolution and global membrane thinning. • SS316L particles exhibit slow, partial dissolution and local membrane thinning. • Dissolved Fe cations are responsible for elevated chemical membrane degradation.