Degradation and Deformation Patterns in Reinforced Fuel Cell Membranes Subjected to Chemo-Mechanical Stress Testing

Thin, reinforced membranes have become the norm for modern fuel cell technology due to favorable performance and durability, yet fuel cell durability studies involving such membranes are relatively scarce in the literature. The present work aims to thoroughly analyze the progressive degradation and deformation patterns of a reinforced membrane subjected to a combined chemo-mechanical accelerated stress test (AST) within a small-scale fuel cell. To achieve this, an in-house designed small-scale, X-ray transparent fuel cell is subjected to a chemo-mechanical AST and the morphology of its components is monitored in 4D using X-ray computed tomography. The findings demonstrate detectable patterns in membrane degradation and deformation that are influenced by factors such as the location of channels and distance from inlet. Additionally, it is shown how membrane creep under the lands increases the risk of failure. Compared to non-reinforced membranes, this work demonstrates that reinforced membranes can achieve very high long-term durability under intensified chemical and mechanical stress, provided that adjacent electrode components are smooth and free from irregular features and assembled in a way that the membrane has adequate mechanical support. The present results can serve as a reference to determine whether any non-uniform feature may alter the degradation.