中文摘要：

采用络合燃烧法制备了两种组成不同的阴极材料La0.6Sr0.4Co0.2Fe0.8O3-δ和La0.54Sr0.44Co0.2Fe0.8-O3-δ,并组装成单元电池,研究了阴极材料A位组成变化对其离子导电能力和固体氧化物燃料电池电性能的影响。研究结果表明增加A位的Sr含量并降低La含量,同时使A位缺位可显著提高其氧离子电导率,从而降低阴极的极化电阻,提升电池的电性能。其机理在于A位组成发生上述变化可以在材料中引入更多的氧空位,同时由于晶胞体积增大,氧空位的活动能力增强,从而使得氧离子在材料内部更容易迁移。

英文摘要：

The cathode materials with two different compositions as La0.6Sr0.4Co0.2Fe0.8O3-δ and La0.54Sr0.44Co0.2Fe0.8-O3-δ were prepared by Pechini method and the unit cells with these two different compositions of cathode materials were assembled. The influence of composition change of A-site of LSCF on its ion conductivity and e- lectrical performance of SOFC was investigated. It has shown that the oxygen ion conductivity can be remark ably enhanced （5 to 6 times） by increasing the concentration of Sr and decreasing the concentration of La in A- site together with slight shortage of stoichiometry in A-site with a result of quite smaller cathode polarization resistance and higher cell electrical performance, whose reason lies in more oxygen vacancy in La0.54Sr0.44Co0.2Fe0.8-O3-δ and bigger crystal cell volume which allow the oxygen ion to move more quickly and freely.