摘要
La1-xSrxCo1-yFeyO3-δ系（LSCF）钙钛矿结构复合氧化物是一类性能优异的离子-电子混合导体,同时具有良好的化学稳定性和催化活性,是很好的中低温固体氧化物燃料电池（SOFC）阴极材料的候选材料.本文测试了制备出的La1-xSrxCo0.2Fe0.8O3-δ（x=0.1~0.5）系材料电导率并探讨了它们的离子导电、电子导电的微观机制,指出除了小极化子导电机制外,还可能有以下几种机理共同作用：1）热激发引起Co^3＋离子的电荷歧化;2）高温下氧空位生成导致的离子补偿;3）Fe^4＋较Co^4＋优先进行电子补偿.
La1-xSrxCo0.2Fe0.8O3-δ（LSCF） perovskite - type composite oxide is a wonderful electronic - ionic conductor, due to its good chemical stability and catalyze activity, which make it a good candidate for Solid Oxide Fuel Cell （SOFC） operating at intermediate temperature. In this paper, researches in the microcosmic conduction mechanism of ionic conduction and electron conduction have been done. Analyses show that the electrical conduction appear to occur via a small - polaron hopping mechanism, and in addition, 1 ） the thermally activated disproportionation of Co^3＋ ions into Co^2＋ and Co^4＋ pairs; 2） the ionic compensation of oxygen vacancies formed at high temperatures; 3 ） Fe^4＋ ions electronic compensation preferential to Co^4＋, all thethree factors above contribute to electrical conduction.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2007年第4期575-578,共4页
Materials Science and Technology
基金
南京理工大学科研发展基金资助项目(AB96055)
关键词
离子电导
电子电导
小极化子
氧空位
电荷歧化
ionic conduction
electron conduction
small - polaron
oxygen vacancy
charge compensation
