Experimental and computational investigations on the SO2 poisoning of (La0.8Sr0.2)0.95MnO3 cathode materials

To study the formation of detrimental phases under the sulfur gas impurity to the long-term degradation in the cathode material, the classic cathode material, (La_0.8Sr_0.2)_0.95MnO₃ (LSM), was prepared, sintered, and annealed at 800, 900, and 1000 ​°C in the sulfur-containing atmospheres, respectively. Through X-ray diffraction, scanning electron microscope, and transmission electron microscopy techniques, as well as the computer coupling of phase diagrams and thermochemistry methodology, the secondary phases, especially the detrimental ones, under different conditions were predicted and experimentally verified correspondingly. Furthermore, sulfur poisoning results indicate that the accelerated tests might have degradation mechanisms different from actual operation conditions. More importantly, comprehensive comparisons among various impurity-containing conditions were also made to recommend better operation parameters.