Monoclinic Sr1鈥?i>xNaxSiO3鈥?.5x: New Superior Oxide Ion Electrolytes

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• 作者：Preetam Singh ; John B. Goodenough
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：July 10, 2013
• 年：2013
• 卷：135
• 期：27
• 页码：10149-10154
• 全文大小：464K
• 年卷期：v.135,no.27(July 10, 2013)
• ISSN：1520-5126

文摘

Oxide ion electrolytes determine the temperature of operation of solid oxide fuel cells, oxygen separation membranes, and oxygen sensors. There is a strong incentive to lower their operating temperatures, in a solid oxide fuel cell, for example, from T_op > 800 掳C to T_op 鈮?500 掳C. The use of low-cost Na⁺ rather than K⁺ as the dopant in monoclinic SrSiO₃ (C12/C1) is shown to provide a larger solid solution range (0 < x 鈮?0.45) in Sr_1鈥?i>xNa_xSiO_3鈥?.5x and to achieve an oxide ion conductivity 蟽_o 鈮?10^鈥? S路cm^鈥? by 525 掳C as a result of lowering the temperature of a smooth transition to full disorder of the mobile oxide ions. The Sr_1鈥?i>xNa_xSiO_3鈥?.5x electrolytes are much less hygroscopic than Sr_1鈥?i>xK_xSiO_3鈥?.5x and are stable with a nickel composite anode in 5% H₂/Ar as well as with cathodes such as La_1鈥?i>xSr_xMnO_{3鈭捨?/sub> and Sr0.7Y0.3CoO3鈭捨?/sub> in air, which makes them candidate electrolytes for intermediate-temperature solid oxide fuel cells or for other applications of oxide ion electrolytes.}