| 引用本文: | 赵捷,马永昌,李晨,王志奇,刘技文.多元掺杂LaCoO3基混合导体的制备与性能研究[J].材料科学与工艺,2010,18(1):56-60,65.DOI:10.11951/j.issn.1005-0299.20100113. |
| ZHAO Jie,MA Yong-chang,LI Chen,WANG Zhi-qi,LIU Ji-wen.Preparation and properties of LaCoO3-based mixed conductors doped with multielement[J].Materials Science and Technology,2010,18(1):56-60,65.DOI:10.11951/j.issn.1005-0299.20100113. |
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| 摘要: |
| 为开发新型高性能中温固体氧化物燃料电池阴极材料,采用改进的固相法制备了Sr2+、Ca2+与Fe3+多元掺杂LaCoO3基稀土复合氧化物La0.8Sr0.1Ca0.1Co0.7Fe0.3O2.9(LSCCF81173)和La0.7Sr0.2Ca0.1Co0.8Fe0.2O2.85(LSCCF72182).利用EDS、XRD、TG-DTA、SEM及热膨胀法等技术,对制备样品的化学成分、物相结构、形成过程、显微组织及热膨胀系数等进行分析,并采用直流四端子法测量样品在25～850℃的混合电导率.XRD和SEM分析表明,经1200℃烧结,LSCCF81173和LSCCF72182样品均具有单一的菱方钙钛矿相和孔隙尺寸与分布较均匀的多孔结构;EDS结果证实,制备的样品中基本不含其他杂质元素;在25～500℃较低温度区间,混合电导率与温度的关系近似为直线,说明较低温阶段样品的导电行为符合小极化子导电机制,且具有较低的导电活化能(Ea=0.07584eV和0.07798eV);Ca2+、Fe3+的共同掺杂有利于降低其热膨胀系数,改善与电解质的热匹配性,并对其原因进行了初步分析. |
| 关键词: 钴酸镧 多元掺杂 离子-电子混合导体 钙钛矿结构 电导率 热膨胀 |
| DOI：10.11951/j.issn.1005-0299.20100113 |
| 分类号:TM911.4 |
| 基金项目:国家自然科学基金资助项目(10704054);天津市科技发展计划资助项目(06TXTJJC14600) |
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| Preparation and properties of LaCoO3-based mixed conductors doped with multielement |
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ZHAO Jie1,2, MA Yong-chang1,3, LI Chen1, WANG Zhi-qi1, LIU Ji-wen1,2
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1.School of Materials Science and Engineering,Tianjin University of Technology,Tianjin 300384,China;2.Tianjin Key Lab for Photoelectric Materials & Devices,Tianjin 300384,China;3.Key Laboratory of Display Materials & Photoelectric Devices,Ministry of Education,Tianjin University of Technology,Tianjin 300384,China
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| Abstract: |
| In order to develop novel cathode materials with high performance for intermediate temperature solid oxide fuel cells ( SOFC ),Sr2 + 、Ca2 + and Fe3 + -doping LaCoO3-based rare earth composite oxides La0.8Sr0.1Ca0.1Co0.7Fe0.3O2.9(LSCCF81173) and La0.7Sr0.2Ca0.1Co0.8Fe0.2O2.85(LSCCF72182) were prepared by improved solid reaction method. The composition,phase structure,forming process,microstructure and thermal expansion coefficient(TEC)of the samples were analyzed by means of EDS,XRD,TG-DTA,SEM and thermo-dilatometry. The electrical conductivity of the samples was measured by DC four-probe technique in the range of 25 ～ 850 ℃. The single phase materials of rhombohedral perovskite-type and porous structure are formed after sintering in air at 1200 ℃ according to XRD patterns and SEM photographs of LSCCF81173 and LSCCF72182. EDS analysis results show that the impurity elements are not found in the synthesized samples. The electrical conduction of the samples accords with a small-polaron hopping mechanism based on the facts that the temperature dependence of the conductivity is linear and the activation energies of the samples are low (Ea = 0. 07584 eV,0. 07798 eV)in the range of 25 ～500 ℃. Ca2+ and Fe3+ doping is an effective method to improve the compatibility of thermal expansion with electrolytes. The reason was analyzed. |
| Key words: LaCoO3 multielement doping ionic-electronic mixed conductor perovskite structure conductivity thermal expansion |
