摘要
以碳酸盐和氧化物为原料，采用微波固相烧结法制备了La0.7Sr0．2Ca0.1CO1-yFeyO3-δ（简称：LSCCF，y=0．1，0．2，和0．4）粉料。借助差示扫描量热-热重分析（DSC-TG）、X射线衍射分析（XRD）和扫描电子显微镜（SEM）对LSCCF粉料的形成过程、晶体结构和粒度形貌进行了研究。实验结果表明，LSCCF粉料的形成过程分为3个阶段——反应原料的变化阶段、LaCoO3基氧化物形成阶段和LSCCF固溶体形成阶段；适宜热处理制度为1200℃下保温30min，且制备出的LSCCF粉料为均一的钙钛矿结构。使用直流四极探针法测定了LSCCF样品在空气气氛下的电导率，发现该体系材料的电导率随着烧结温度的升高和Fe2＋含量的减少而变大，在500-800℃范围内，大于500S／cm，高于固相合成法的电导率最大值100S／cm。LSCCF粉料与Ce0.8Sm0.2O2电解质的混合物在800℃下烧结10h后没有新相生成，表明LSCCF粉料与Ce0.8Sm0.2O2电解质具有良好的化学相容性。
The powders of La0.7Sr0.2Ca0.1CO1-yFeyO3-δ （LSCCF , y = 0.1,0. 2, ana 0. 4 ） as a cathode materials for intermediate temperature solid oxide fuel cells were synthesized by using a microwave sintering method with carbonates and oxides. The formation process, crystal structure and particle size micrograph of LSCCF powders, were investigated with DSC-TG, XRD and SEM. The experimental results show that the formation process of LSCCF powders can be divided into three stages： change of raw materials, formation of LaCoO3 based oxides and formation of LSCCF solid solution, and that the calcined powders at 1 200 ℃ for 30 min are all of single perovskite phase. The electrical conductivity of LSCCF sample increased with the increasing of sintering temperature and decreasing of the content of Fe2＋, higher than 500 S/cm and bigger than maximum 100 S/ cm from conventional sintering method in the range of 500 - 800 ℃ by four--probe DC method. Heating the mixture of La0.7 Sr0.2 Ca0.1Co1-y FeyO3-δ and Ce0.8 Sm0.2 O2 at 800℃ for 10 h in air, no occur solid reaction and new phase between the two materials. So, LSCCF electrode material possesses goodchemical compatibility with Ce0.8 Sm0.2 O2 electrolyte.
出处
《有色矿冶》
2008年第1期36-39,43,共5页
Non-Ferrous Mining and Metallurgy
