Electrical properties of grain boundaries and size effects in samarium-doped ceria

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• 作者：Duanting Yan ; Xiaomei Liu ; Xinyu Bai ; Li Pei ; Minzhang Zheng ; Chengjun Zhu ; Dejun Wang ; Wenhui Su
• 关键词：Doped ceria ; Apparent specific grain-boundary conductivity ; Siliceous phase ; Space-charge potential ; Solid oxide fuel cells
• 刊名：Journal of Power Sources
• 出版年：2010
• 出版时间：1 October 2010
• 年：2010
• 卷：195
• 期：19
• 页码：6486-6490
• 全文大小：1040 K

文摘

Ce_0.85Sm_0.15O_1.925 samples have been prepared using the glycine-nitrate process. The effects of microstructure on their electrical properties were investigated by X-ray diffraction, density measurements, scanning electron microscopy and AC impedance spectroscopy. The grain-boundary conductivities and total conductivities increase with decreasing grain size for sintered densities of 95 % or greater. The bulk conductivities are nearly independent of grain size for sintered densities of 95 % or greater. It is found that the space-charge potential is nearly independent of grain size and the increase of the conduction path width is responsible for the increase of the apparent specific grain-boundary conductivity. The power densities and current densities of single cells based on Ce_0.85Sm_0.15O_1.925 electrolytes with different grain size are evaluated.