M. Gao, H. L. Wang, School of Materials Science and Engineering, Xi’an Jiaotong University, Xi'an, China; C. X. Li, G. J. Yang, C. J. Li, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, China
Strontium-doped lanthanum cobaltite (LSCO) is a potential perovskite oxide material for application to solid oxide fuel cell (SOFC) due to its high electronic conductivity. However, high thermal expansion coefficient of LSCO limits its direct application as a cathode layer in SOFC. In this study, cordierite was employed to produce a composite coating with LSCO by flame spray. The composite powder was prepared through blending LSCO and cordierite powders in different contents of cordierite. The microstructure, thermal expansion coefficient (TEC) and electronic conductivity of the coatings were characterized by SEM, dilatometer and four-probe DC measurement. The results indicate that the addition of cordierite to LSCO leads to significant reduction of the thermal expansion coefficient of composite coatings. Moreover, with the increase of cordierite content in the composite coating both the electrical conductivity and the thermal expansion coefficient is decreased. Through controlling of composite powder composition and structure, the properties of the LSCO-cordierite composite coating can be optimized in terms of application to SOFC.
Summary: Strontium-doped lanthanum cobaltite (LSCO) is a potential perovskite oxide material for application to solid oxide fuel cell (SOFC) due to its high electronic conductivity. However, high thermal expansion coefficient of LSCO limits its direct application as a cathode layer in SOFC. In this study, cordierite was employed to produce a composite coating with LSCO by flame spray. The composite powder was prepared through blending LSCO and cordierite powders in different contents of cordierite. The microstructure, thermal expansion coefficient (TEC) and electronic conductivity of the coatings were characterized by SEM, dilatometer and four-probe DC measurement. The results indicate that the addition of cordierite to LSCO leads to significant reduction of the thermal expansion coefficient of composite coatings. Moreover, with the increase of cordierite content in the composite coating both the electrical conductivity and the thermal expansion coefficient is decreased. Through controlling of composite powder composition and structure, the properties of the LSCO-cordierite composite coating can be optimized in terms of application to SOFC.
