Proton Exchange Membrane Fuel Cell Degradation Study for Stationary Application

Kurzfassung

Proton Exchange Membrane Fuel Cells, PEMFC, are a promising technology for stationary power generation due to their high efficiency and low environmental impact. However, their widespread adoption is limited by durability issues and performance degradation over time. This dissertation, conducted in collaboration with the Deutsches Zentrum für Luft- und Raumfahrt, DLR, investigated degradation mechanisms in single-cell and stack PEMFC configurations and evaluated the use of Accelerated Stress Tests, AST, to support the development of longer-lasting fuel cells for stationary applications. The study evaluated the degradation of a commercial of a Membrane ElectrodeAssembly, MEA, in single-cell and short-stack configurations, with the aim of separating the intrinsic degradation of the MEA from that caused by system components. Load cycling tests and electrochemical techniques showed that degradation in the single cell configuration was significantly lower than in stack cell, highlighting the strong influence of system components on performance losses. No silicon contamination was observed, confirming the isolation of external contamination sources. Although a significant reduction in the electrochemically active surface area, ECSA, was detected, this loss did not fully explain the observed voltage decay, indicating the presence of additional degradation mechanisms. The study showed that the investigated AST protocol could reproduce some degradation effects but did not meaningfully accelerate the main long term degradation mechanisms under realistic conditions, so no reliable acceleration factor could be determined. This suggests the protocol is not fully representative of real ageing behavior. The results also emphasized the role of catalyst surface processes, reversible degradation, and shutdown strategies. Controlled cooling and hydrogen soaking enabled partial voltage recovery and helped reduce catalyst degradation, highlighting their potential for practical system integration. Overall, the work improves understanding of PEMFC degradation and supports the development of better durability testing methods and lifetime extension strategies for stationary applications.