物理化学学报 >> 2012, Vol. 28 >> Issue (06): 1380-1386.doi: 10.3866/PKU.WHXB201203304

电化学和新能源 上一篇    下一篇

MgO或Fe2O3掺杂Ce0.8Nd0.2O1.9固体电解质的结构和电性能

刘建伟1, 周德凤1, 杨梅1, 罗飞1, 孟健2   

  1. 1. 长春工业大学化学与生命科学学院, 长春 130012;
    2. 中国科学院长春应用化学研究所,稀土资源利用国家重点实验室, 长春 130022
  • 收稿日期:2011-12-14 修回日期:2012-03-29 发布日期:2012-05-17
  • 通讯作者: 周德凤 E-mail:defengzhou65@126.com
  • 基金资助:

    国家自然科学基金(20871023)和吉林省科技发展计划项目(20101549)资助

Structure and Electrical Properties of MgO or Fe2O3-Doped Ce0.8Nd0.2O1.9 Solid Electrolytes

LIU Jian-Wei1, ZHOU De-Feng1, YANG Mei1, LUO Fei1, MENG Jian2   

  1. 1. School of Chemistry and Life Science, Changchun University of Technology, Changchun 130012, P. R. China;
    2. State Key Laboratory of Rare Earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
  • Received:2011-12-14 Revised:2012-03-29 Published:2012-05-17
  • Contact: ZHOU De-Feng E-mail:defengzhou65@126.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20871023) and Science Research Foundation of Jilin Province, China (20101549).

摘要: 采用溶胶-凝胶法合成SiO2含量为0.05% (w, 质量分数)的Ce0.8Nd0.2O1.9 (NDC)粉体(NDCSi). 分别将0-2.0% (x, 摩尔分数)的MgO或FeO1.5添加到NDCSi粉体中, 经10 MPa压片后于1300 °C烧结6 h. 采用X射线衍射(XRD)、拉曼(Raman)光谱和场发射扫描电子显微镜(FE-SEM)对样品进行结构表征. 采用交流(AC)阻抗谱测试样品导电性能. 结果表明: 所有样品均呈现单一立方萤石结构. MgO或Fe2O3掺杂于NDCSi 体系, 均可提高材料的致密度, 降低烧结温度, 提高材料的晶界电导率和总电导率. 掺杂MgO或Fe2O3样品的相对密度(>93%) 高于NDC 或NDCSi ( 约86%), 有效促进了样品致密化. 掺杂Fe2O3 或MgO 的样品(NDCSi+0.5FeO1.5 或NDCSi+2.0MgO)具有最高电导率, 550 °C 时总电导率分别是6.3×10-3 或2.9×10-3 S·cm-1, 是NDCSi 样品总电导率(1.1×10-3 S·cm-1)的5.7 和2.6 倍. MgO或Fe2O3掺杂于NDCSi 样品对晶界电导率的影响比晶粒电导率更明显. MgO或Fe2O3掺杂于NDCSi均具有烧结助剂和晶界清除剂的双重作用, 但清除杂质SiO2的机制不同.

关键词: 固体电解质, 掺钕氧化铈, 晶界清除剂, 电导率, 烧结助剂

Abstract: A precursor powder of Ce0.8Nd0.2O1.9 (NDC) containing 0.05% (mass fraction) SiO2 as an impurity (NDCSi) was doped with 0-2.0% (molar fraction) MgO or FeO1.5 via the sol-gel method. After pressing at 10 MPa, the samples were sintered at 1300 ° C for 6 h. The structure of the pellets was characterized by X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). The electrical conductivity of the pellets was measured using AC impedance spectroscopy. All of the samples exhibited a cubic fluorite structure. Doping with MgO or Fe2O3 lowered the sintering temperature, and increased the density, grain boundaries and total conductivity of NDCSi. The relative density of the samples doped with Fe2O3 or MgO (>93%) was higher than those of NDC or NDCSi (about 86%), suggesting these dopants are effective at promoting densification. NDCSi + 0.5FeO1.5 and NDCSi + 2.0MgO samples exhibited the highest conductivities of 0.63 × 10-2 and 0.29 × 10-2 S · cm-1, respectively, which are 5.7 and 2.6 times larger than that of NDCSi (0.11×10-2 S·cm-1) at 550 °C. Doping with MgO or Fe2O3 had a larger effect on the grain boundary conductivity of SDCSi than the bulk conductivity. These results indicate that MgO and Fe2O3 are effective sintering aids as well as grain boundary scavengers with different mechanisms.

Key words: Solid electrolyte, Neodymium-doped ceria, Grain boundary scavenger, Electrical conductivity, Sintering aid

MSC2000: 

  • O649