4D in situ visualization of chemo-mechanical membrane degradation in fuel cells: Understanding and mitigating edge failures

Fuel cell is a zero-emission energy conversion device using hydrogen and oxygen to generate power with water as the only by-product. Membrane electrode assembly (MEA) edges are sensitive regions that could influence the overall durability of fuel cells, where membrane degradation at poorly designed edges may lead to premature cell failures. In this work, two MEA edge designs were implemented to study their robustness during combined chemical and mechanical accelerated stress testing. Four-dimensional in situ visualization, enabled by X-ray computed tomography, was performed to understand and mitigate the edge failure issue. Interaction of adhesive-containing polyimide gasket with catalyst coated membrane (CCM) was identified as the key contributor to premature edge failures, which was mitigated by using a non-adhesive inert frame at the CCM interface, thus enabling a robust MEA edge wherein the failures were shifted into the active area. Overall, findings of this research may contribute to robust fuel cell manufacturing and enhanced membrane durability.