EFFECT OF SR CONTENT ON THE MICROSTRUCTURE DEVELOPMENT AND ELECTROCHEMICAL PERFORMANCE OF LA1-XSRXMNO3 FILMS

Abstract

Strontium doped lanthanum manganite (La1-xSrxMnO3 -LSM) is the conventionally used oxygen reduction electrocatalyst in solid oxide fuel cell cathodes. In recent years, Sr-segregation at the LSM surface has been shown to occur and limit oxygen reduction performance. Therefore, the effect of Sr-doping on the microstructure development and performance of liquid precursor-derived LSM film electrodes with different Sr-contents was investigated in this study. It was found that as Sr content increased, LSM structure became amorphous, which is beneficial for the electrochemical performance. Despite this fact, the undoped LaMnO3 film performed better in comparison to heavily Sr-doped LSM, likely because of Sr-segregation at the Sr-doped electrode surface. These results suggested that trying to avoid Sr doping in LaMnO3 electrodes may be a good strategy if its microstructural instability could be addressed, to achieve high performance solid oxide fuel cell cathodes.