Abstract Scope |
To study the detrimental phases under the single or multiple gas impurities to the long-term degradation in the SOFC cathode systems, three common cathode materials, (La0.8Sr0.2)0.95MnO3 (LSM), (La0.6Sr0.4)0.95(Co0.2Fe0.8)O3 (LSCF), and La2NiO4 (LNO), were prepared, sintered, and annealed at 800, 900 and 1000 ℃ in the Sulfur, Chromium and/or water vapor-containing atmospheres, respectively. Through X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission electron microscopy (TEM), as well as the CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) methodology, the secondary phases, especially the detrimental ones, under different conditions (temperatures and the partial pressure of oxygen and impurities) were predicted and experimentally verified correspondingly, which shows considerable agreements among one another. Furthermore, sulfur poisoning results indicate that the accelerated tests might have distinct degradation mechanisms in terms of the real conditions. More importantly, comprehensive comparisons among the three candidates under different impurity-containing conditions were also made to recommend promising cathode materials. |