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SOFC Cathode Degradation Due to Salt Contamination

Tuesday, 25 July 2017: 16:20
Grand Ballroom West (The Diplomat Beach Resort)
N. Thambiraj, C. Suciu, I. Waernhus, A. Vik (CMR Prototech AS), and A. C. Hoffmann (University of Bergen, Dept. of Physics and Technology)
One of the fundamental impediments to the wide-spread commercialization of fuel cell technology is questions about the robustness and durability of this type of installation. In the course of a larger experimental program designed to answer these questions, specifically for operation in a marine environment, a series of tests were carried out to determine the sensitivity of SOFC cathodes to salt contamination in the gaseous feed stream. The salt content in the feed stream was varied by adding crystalline salt in the inlet piping, allowing it to sublimate at temperatures designed to give the desired salt concentration in the feed to the cathode. Both short-term and long-term degradation tests were performed, and in addition to characterizing the performance using the I-V curves, the microstructure of the cathodes were investigated using scanning electron microscopy before and after each run. The tests showed that there is degradation of the cathode due to the salt contamination, both in the short and the long term. While it was difficult to determine the reason for the short-term degradation, the long-term degradation was much more severe, and can be attributed to two effects: the salt appeared as crystals in the cathode microstructure and had a coarsening effect, and the presence of the salt gave rise to delamination of the cell at the cathode-electrolyte interface, something that was not observed under otherwise like operation conditions and -duration without salt contamination.