Chemo-mechanical durability of reinforced fuel cell membranes in the presence of foreign metallic particles: Part 3 – Mitigation strategy

This article is the third and final part of a three-part series examining the fuel cell membrane durability impacts of foreign metallic particles within the membrane electrode assembly (MEA), which may originate from industrial production machinery. Parts 1 and 2 investigated the respective effects of particle chemical composition and physical geometry, whereas the present work, Part 3, examines the mitigation capabilities of a robust, thin membrane that is both mechanically and chemically reinforced in order to neutralize the mechanical and chemical stressors associated with the particles. Using chemo-mechanical accelerated stress testing and 4D in-situ X-ray computed tomography of particle-laden MEAs, the mitigated membrane shows suppressed local and global thinning with 55 ± 5 μm Fe particles amenable to complete dissolution. Furthermore, the mitigated membrane demonstrates excellent integrity and stress relaxation behaviour, accommodating larger 500 μm geometrically distinct stainless steel 316L particles with complex 3D features. However, it failed to mitigate the synergistic fabrication and operational impact arising from 500 μm soluble Fe particles, deemed to be the most severe. Moreover, a fuel cell performance tradeoff is identified with the mitigated membrane MEA when the Fe ion contamination exceeds 100 ppm, as quantified by laser ablation inductively coupled plasma mass spectrometry.