Lifetime Prediction Approach Applied to the Aquivion™ Short Side Chain Perfluorosulfonic Acid Ionomer Membrane for Intermediate Temperature Proton Exchange Membrane Fuel Cell Application

Degradation and durability studies of the short side chain perfluorosulfonic acid ionomer membrane, Aquivion™, of Solvay Specialty Polymers, are described in a fuel cell operation beyond 100 °C. Specific electrochemical accelerated stress tests under a dynamic electric load cycling profile were developed to submit the membrane to hydration–dehydration cycles, while the effect of operation temperature was also investigated to reproduce typical power demands and/or thermal gradient periods likely to be encountered during seasonal variation of a micro-combined heat and power system. Aquivion™ is a high performance membrane which is shown in this study to sustain operation until 110 °C, higher than was possible with Nafion® under similar conditions. Post-test observations studies by electron microscopy and ex situ tensile measurements bring to light modifications of membrane thickness and mechanical properties that rationalize an upper operating temperature of 120 °C. Membrane thermal annealing is shown to increase lifetime with the ageing procedures used. A predictive lifetime model is proposed by correlating the estimated lifetime values and the experimental data via a lifetime coefficient.