Strontium doping effect on phase homogeneity and conductivity of Ba1-xSrxCe0.6Zr0.2Y0.2O3-delta proton-conducting oxides

作者：Lee Kan Rong; Tseng Chung Jen; Chang Jeng Kuei; Hung I Ming; Lin Jing Chie; Lee Sheng Wei^*

来源：International Journal of Hydrogen Energy, 2013, 38(25): 11097-11103.

DOI：10.1016/j.ijhydene.2013.01.043

• Proton-conducting electrolyte
• Solid oxide fuel cells
• Ba1-xSrxCe0.6Zr0.2Y0.2O3-delta
• Chemical stability
• Ionic conductivity

Ba1-xSrxCe0.6Zr0.2Y0.2O3-delta (0.0 %26lt;= x %26lt;= 1.0) proton-conducting oxides have been prepared using a citrate-EDTA complexing sol-gel method. In this study, the relationship between the Sr doping content and microstructure, chemical stability against CO2, and conductivity of the sintered Ba1-xSrxCe0.6Zr0.2Y0.2O3-delta pallets are systematically investigated using XRD, SEM, micro-Raman spectroscopy, and dc two-probe measurements. All sintered Ba1-xSrxCe0.6Zr0.2Y0.2O3-delta oxides exhibit excellent chemical stability after being exposed to the CO2 ambient at 600 degrees C for a long duration; nevertheless, their microstructures and conductivities are very sensitive to the Sr doping amount. The Sr incorporation is found to apparently suppress the formation of CeO2-like second phase, and enhance the grain growth in sintered oxides. Among all sintered samples, the Ba0.8Sr0.2Ce0.6Zr0.2Y0.2O3-delta pallet has the highest conductivity, 0.009 S/cm at 800 degrees C. This result can be attributed to the competition between the elimination of CeO2- or (Zr,Ce,Y)O-2-like phase inhomogeneity and enhanced grain growth in sintered oxides, both of which adversely influence the ionic conductivity. This work demonstrates that Ba1-xSrxCe0.6Zr0.2Y0.2O3-delta would be a promising electrolyte for H+-SOFC applications if the Sr doping is well controlled.

• 出版日期2013-8-21
• 单位中央民族大学