【摘要】 以Sm0.2Ce0.8O1.90(SDC)为电解质,用交流阻抗谱研究了烧结温度和原料粉体制备过程等因素对复合阴极[50wt％(La0.85Sr0.15)0.9MnO3-δ(LSM)+50wt％SDC]的界面电阻的影响. LSM+甘氨酸法制备的SDC和LSM+共沉淀法制备的SDC的复合阴极对应界面电阻最小时的烧结温度分别为1200和1250℃;800℃时,它们的最小界面电阻分别为0.78和0.35Ω·cm2.用扫描电子显微镜观察两种不同复合阴极微结构,发现其微结构与原料粉体的形貌有着密切的关系,而微结构又同时决定了阴极的界面电阻和电导率.更多还原

【Abstract】 Microstructures, interfacial resistances, and activation energy of the symmetrical composite cathodes [50wt%(La0.85Sr0.15)0.9MnO3-δ(LSM)+50wt% Sm0.2Ce0.8O1.90] were studied for intermediate temperature (550-800℃) solid oxide fuel cells (IT-SOFCs) based on Sm0.2Ce0.8O1.90 (SDC) electrolytes. The optimum sintering temperatures for LSM+GNP-SDC and LSM+OCP-SDC composite cathodes are 1200℃and 1250℃, respectively. The interfacial resistances at 800℃are 0.78 and 0.35Ω·cm2, respectively, for LSM+GNP-SDC and LSM+OCP-SDC, as determined using AC impedance spectroscopy. The electrical conductivity of composite electrodes depends on the electrodes microstructures, which are greatly influenced by starting powder characteristics and sintering temperatures.更多还原