Preparation of Sm_(0.5)Sr_(0.5)CoO_3-La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05)O_3 Composite Cathodes Using Wet-chemistry Method and the Characterization of Their Properties
用湿化学法制备了Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5)中温固体氧化物燃料电池复合阴极,其中SSC用甘氨酸-硝酸盐法合成,LSGMC5用柠檬酸盐法合成.XRD结果表明,甘氨酸-硝酸盐法制备的SSC在焙烧温度大于1223K即表现为单一的钙钛矿结构.随焙烧温度的升高,SSC粉末颗粒增大,导致相应电极与电解质的结合变差.复合电极的性能显著依赖于SSC粉末的焙烧温度,其中含1223K焙烧SSC粉末的电极表现出最小的欧姆电阻以及电极电阻.973K、氧气中、1A·cm-2电流密度下该电极的极化过电位仅为0.077V,远小于固相法合成的电极.Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5) composite cathodes for intermediate temperature solid oxide fuel cells were prepared using wet-chemistry method. The SSC powders were prepared using the glycine-nitrate method and the LSGMC5 powders were synthesized using the citrate method. The XRD pattern of SSC powders calcined at temperatures higher than 1223 K corresponded to a desired perovskite structure. With the increase in calcining temperature, the size of the SSC particles increased, which leaded to a weak adhesion to the electrolyte for corresponding electrodes. The performance of the SSC-LSGMC5 composite electrodes depended strongly on the calcining temperature of SSC powders, and the electrodes based on SSC calcined at 1223 K exhibited the lowest ohmic resistance and polarization resistance. The overpotential at 973 K in oxygen under 1 A· cm-2 current density was as low as 0.077 V, which was much lower than that of electrodes prepared using solid-state reaction.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资
