溶胶凝胶法合成La0.7Sr0.3Fe0.8Co0.2O3影响因素的研究

摘要

In this study, La0.7Sr0.3Fe0.8Co0.2O3(LSFC)powder was synthesized as the intermediate-temperature solid oxide fuel cell cathode material. The factors influencing the PVA-modified powder synthesized by sol-gel method were analyzed, and the optimal experimental conditions were determined: when pH=7, the mass ratio of the PVA to nitrate was 1:4, and the molar ratio of citric acid to metal ion was 1.6:1, good transparent sol could be obtained. The sol was gelatinized after 12 h aging, and turned into LSFC precursors after being treated at 155℃in an oven. The LSFC precursors formed the powders with the single and stable perovskite structure and good particle size distribution after being calcined at 900℃ for 2 h.%以合成中温固体氧化物燃料电池阴极La0.7Sr0.3Fe0.8Co0.2O3(LSFC)粉体为研究对象，探讨了PVA改进的溶胶凝胶法合成粉体的影响因素，获得最优实验条件。当pH值=7，柠檬酸与金属离子摩尔比为1.6∶1；PVA与硝酸盐质量比为1∶4时，能够形成形态良好且透明澄清的溶胶，再经12 h的陈化形成凝胶，然后在155℃烘箱中使凝胶膨化制得LSFC前驱体。LSFC前躯体在900℃煅烧2 h后形成晶体结构稳定、粒径分布均匀、具有单一钙钛矿结构的粉体。