Thermal expansion and electrochemical performance of La_0.7Sr_0.3CuO_3−δ

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• 作者：Xifeng Ding ; Chong Cui ; Lucun Guo
• 关键词：SOFC ; Composite cathode ; Impedance spectroscopy ; Thermal expansion ; Electrochemical properties
• 刊名：Journal of Alloys and Compounds
• 出版年：2009
• 出版时间：29 July 2009
• 年：2009
• 卷：481
• 期：1-2
• 页码：845-850
• 全文大小：1062 K

文摘

The thermal expansion, electrical conductivity and electrochemical properties of La_0.7Sr_0.3CuO_3−δ–Sm_0.2Ce_0.8O_2−δ (LSCu–SDC) composite cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs) were investigated. The addition of SDC to LSCu matrix materials significantly reduced the thermal expansion mismatch between them. SDC also suppressed the LSCu grain growth and increased the porosity of the composite cathode. The electrochemical performance of the interfaces between the porous LSCu–SDC composite cathode and dense SDC electrolyte was examined using AC impedance spectroscopy. The polarization resistance was significantly reduced from 0.62 Ω cm² for pure LSCu to 0.29 Ω cm² for LSCu–25 wt. % SDC under open circuit condition at 800 °C, showing that the La_0.7Sr_0.3CuO_3−δ–Sm_0.2Ce_0.8O_2−δ composite cathode is very promising to be used as a new cathode for IT-SOFCs.