TY  - JOUR
AU  - Yin, Xiaoyan
AU  - Bencze, Laszlo
AU  - Motalov, Vladimir
AU  - Spatschek, Robert
AU  - Singheiser, Lorenz
TI  - Thermodynamic Perspective of Sr-Related Degradation Issues in SOFCs
JO  - International journal of applied ceramic technology
VL  - 15
SN  - 1546-542X
CY  - Westerville, Ohio
PB  - Wiley-Blackwell
M1  - FZJ-2017-07080
SP  - 380–390
PY  - 2018
AB  - (La,Sr)(Co,Fe)O3-δ is very common as cathode material in SOFC applications. Sr in this type of cathode material is very reactive to form secondary phases with other oxides, which affect micro-structures and properties of the cathode materials, GDC layers and ZrO2-based electrolytes. The Sr-related degradation issues, Cr poisoning and volatile Sr species formation, are studied. As supplement to existing experimental knowledge on Cr poisoning, specific thermodynamic aspects for Cr poisoning are discussed. The thermodynamic calculations show that the partial pressure pCrO3 has a stronger temperature dependence than pCrO2(OH)2, and when considering the reaction between SrO and CrO3(g), dependent on different pCrO3 and pO2, different Sr–Cr–O compounds SrCrO4, SrCrO3, Sr3Cr2O8 or Sr2CrO4 could be formed. In addition, thermodynamic calculations show that in the presence of water vapor, formation of volatile Sr(OH)2 is possible as well. pSr(OH)2 depends on temperature, pH2O and SrO activity and can be of the same order of magnitude as pCrO2(OH)2. Volatile Sr(OH)2 can diffuse through the porous GDC layer and react with ZrO2-based electrolytes to form SrZrO3 precipitates. The reaction between gaseous Sr species and 8YSZ sheet is studied experimentally. The surface of the 8YSZ sheet is investigated by SEM coupled with EDS, confirming the deposition of Sr.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000424816400013
DO  - DOI:10.1111/ijac.12809
UR  - https://juser.fz-juelich.de/record/838483
ER  -