Sm_(0.5-x)Gd_xSr_(0.5)CoO_(3-δ)阴极材料的制备及其性能表征  

Preparation and Characterization of Sm_(0.5-x)Gd_xSr_(0.5)CoO_(3-δ) Cathode Materials

作　　者：郭晓燕[1,2] 周芬[1] 安胜利[1] 宋希文[1] 许贺龙[1,2] 

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]大兴安岭职业学院林业管理系,黑龙江大兴安岭165000

出　　处：《稀土》2011年第5期25-29,共5页Chinese Rare Earths

基　　金：国家自然科学基金项目(50564002);国家重点基础研究发展计划(973计划)项目(2008CB617603)

摘　　要：采用固相法制备了钙钛矿型氧化物Sm0.5-xGdxSr0.5CoO3-δ(x=0,0.1,0.2,0.3,0.4,0.5)粉体。利用XRD分析材料的物相组成,用热膨胀仪测定了材料的热膨胀系数。利用交流阻抗法测试了Sm0.5-xGdxSr0.5CoO3-δ/SDC复合阴极的极化电阻。结果表明,粉体在1200℃热处理6h后形成正交钙钛矿型结构;从室温到800℃范围内,材料的平均热膨胀系数TEC为11.43×10-6℃-1～14.35×10-6℃-1,掺杂Gd3+以后Sm0.5-x GdxSr0.5CoO3-δ样品的热膨胀系数比Sm0.5Sr0.5CoO3-δ样品的热膨胀系数略有增加。800℃时,复合阴极的极化电阻随x的增大先减小后增大,在x=0.1时,最小为0.05Ω;所有样品的极化电阻随测试温度的升高而降低。Perovskite-type oxide Sm0.5-xGdxSr0.5CoO3-δ（x=0,0.1,0.2,0.3,0.4,0.5） powders are prepared using a solid-phase synthesis method.The crystal structure is characterized by XRD.The polarization resistances of the composite cathode Sm0.5-xGdxSr0.5CoO3-δ/SDC are measured by the AC impedance.The results show that the powder has orthogonal perovskite structure after sintered for 6h at 1200℃.The thermal expansion coefficient（TEC） is 11.43×10-6℃-1~14.35×10-6℃-1 from 25℃ to 800℃ and the TEC of Sm0.5-xGdxSr0.5CoO3-δ sample is larger than the pure cathode Sm0.5Sr0.5CoO3-δ.The polarization resistance of composite cathode first decreases and then increases with increase of x at 800℃,the minimum value is 0.05Ω when x=0.1.In addition,polarization resistance decreases with temperature increasing.These results suggest that SGSC could be promising materials as the cathodes for SOFCs working at intermediate temperatures.

关 键 词：钙钛矿结构 物相组成 热膨胀系数 极化电阻 

分 类 号：TM911.4[电气工程—电力电子与电力传动] O614.33[理学—无机化学]