中文摘要：

复合钙钛矿氧化物La0．6Sr0．4Co0．2Fe0．8O3-δ是一种适于中温固体氧化物燃料电池的阴极材料．采用柠檬酸螯合法合成了La0．6Sr0．4Co0．2Fe0．8O3-δ粉体，并通过XRD和SEM，研究了前驱体溶液pH值和煅烧温度对其粉体晶相结构的影响；同时，通过烧结体的SEM和交流阻抗分析，详细讨论了前驱体溶液pH值和烧结温度对烧结体显微结构和阻抗特性的影响．结果表明，前驱体溶液pH=4、煅烧温度为900。C的粉体，1400℃下烧结2h获得的烧结体，具有最低的阻抗．

英文摘要：

Composite perovskite oxides La0.6Sr0.4Co0.2Fe0.8O3-δ （LSCF） is an optional cathode material for the intermediate temperature solid oxide fuel cells. La0.6Sr0.4Co0.2Fe0.8O3-δ powders were synthesized by a citrate method. The effects of the precursor solution pH value and the calcining temperature on the phase structure of the LSCF powders were investigated by X-ray diffraction. Besides, the impacts of the precursor solution pH value and sintering temperature on the morphology and impedance characteristics of the LSCF sintered bodies were studied by SEM, AC impedance analysis, respectively. The alternate-current impedances of the LSCF sintered bodies were analysized based on the Voigt-type equivalent circuit model. The results show that the LSCF sintered body has the lowest impedance in the condition that the precursor solution pH is 4, the calcination temperature is 900℃, and the sintering temperature is 1400℃ for 2h, respectively.