Influence of nano-structural feature on electrolytic properties in Y2O3 doped CeO2 system
Influence of nano-structural feature on electrolytic properties in Y2O3 doped CeO2 system
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DOI：
10.1016/s1468-6996(03)00047-0
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发表时间：
2003-01
影响因子：
5.5
通讯作者：
T. Mori;J. Drennan;Yarong Wang;G. Auchterlonie;Ji-guang Li;A. Yago
中科院分区：
文献类型：
--
作者：
T. Mori;J. Drennan;Yarong Wang;G. Auchterlonie;Ji-guang Li;A. Yago
掺杂氧化铈（CeO 2）是一种萤石型氧化物，在氧化气氛下，其氧化物离子电导率高于氧化钇稳定的氧化锆。因此，这些材料在固体氧化物燃料电池（SOFC）的“低温操作（500-650 ℃）”中的应用已经显示出相当大的兴趣。采用碳酸盐共沉淀法制备了YxCe 1− xO 2− δ（x= 0.05，0.1，0.15，0.2和0.25）超细粉体。研究了烧结体中电解质性质与纳米结构特征之间的关系。用透射电子显微镜（TEM）研究了Y0.05Ce0.95O1.975、Y0.15Ce0.85O1.925和Y0.25Ce0.75O1.875三种典型样品的显微结构。在Y0.15Ce0.85O1.925和Y0.25Ce0.75O1.875烧结体的电子衍射图背景中观察到大的漫散射。这意味着具有有序结构的共格微畴存在于微结构中。低电导率、高激活能的Y 0.2 5 Ce 0.75 O 1.875烧结体具有较大的微畴，而高电导率、低激活能的Y 0.15 Ce 0.85 O 1.92 5烧结体的微畴尺寸远小于Y 0.2 5 Ce 0.75 O 1.875烧结体。TEM观察告诉我们，具有有序结构的共格微区的大小与样品的电导率和活化能等电解质性质密切相关。研究结果表明，在纳米尺度上控制Y2 O3掺杂CeO 2体系的微区尺寸是开发高质量燃料电池固体电解质的关键。
Doped ceria (CeO 2) compounds are fluorite type oxides which show oxide ionic conductivity higher than yttria stabilized zirconia, in oxidizing atmosphere. As a consequence of this, considerable interest has been shown in application of these materials for'low temperature operation (500–650 C)'of solid oxide fuel cells (SOFCs). In this study, Y x Ce 1− x O 2− δ (x= 0.05, 0.1, 0.15, 0.2 and 0.25) fine powders were prepared using a carbonate co-precipitation method. The relationship between electrolytic properties and nano-structural features in the sintered bodies was examined. The micro-structures of Y 0.05 Ce 0.95 O 1.975, Y 0.15 Ce 0.85 O 1.925 and Y 0.25 Ce 0.75 O 1.875 as representative three specimens have been investigated in more detail with transmission electron microscopy (TEM). The big diffuse scattering was observed in the background of electron diffraction pattern recorded from Y 0.15 Ce 0.85 O 1.925 and Y 0.25 Ce 0.75 O 1.875 sintered bodies. This means that the coherent micro-domain with ordered structure is in the micro-structure. While Y 0.25 Ce 0.75 O 1.875 sintered body with low conductivity and high activation energy has big micro-domains, the micro-domain size in Y 0.15 Ce 0.85 O 1.925 with high conductivity and low activation energy was much smaller than that of Y 0.25 Ce 0.75 O 1.875. TEM observation gives us message that the size of coherent micro-domain with ordered structure would closely relate to the electrolytic properties such as conductivity and activation energy in the specimens. It was concluded that a control of micro-domain size in nano-scale in Y 2 O 3 doped CeO 2 system was a key for development of high quality solid electrolyte in fuel cell application.