摘要
固体氧化物燃料电池 (SOFC)是一种先进的能量转换装置 ,具有高效、无污染、环境友好等优点 ,阴极材料是它的重要组件。La1 -xSrxCo0 2 Fe0 8O3钙钛矿结构氧化物是一类性能优异的离子 电子混合导体 ,可作为其阴极材料。本文采用固相反应法制备出固体氧化物燃料电池的多孔阴极材料La1 -xSrxCo0 2 Fe0 8O3(LSCF ,x =0 1～ 0 6 ) ,通过XRD ,TG DTA等测试技术研究了LSCF的结构与制备过程 ,采用直流四探针法测试了样品的电导率 ,同时测定了这类组成样品的热膨胀系数。结果表明 ,制备的样品为单一钙钛矿相 ,随着Sr含量增加 ,XRD衍射峰值向高角度方向稍有偏移。电导率随着温度及Sr含量的变化出现极大值 ,其导电机理在低温下是以小极化子跃迁机理为主 ,高温下则是氧空位的电荷补偿占主导地位。
Solid Oxide Fuel Cells(SOFC) is an advanced energy-conversion device which has characteristics of high efficiency,non-pollution,good to environment advantages,etc.Cathode material is an important part.La_ 1-x Sr -xCo_ 0.2 Fe_ 0.8 O -3(ABO_3) perovskite-type composite oxides are a wonderful electronic-ionic conductor,which makes it be a potential candidate for SOFC.In this paper,La_ 1-x Sr_xCo_ 0.2 Fe_ 0.8 O_3(LSCF,x 0.1～0.6) cathode materials are prepared by solid phase reaction technique,and the structure and preparation process are studied by modern test technique,such as XRD,TG/DTA.The electrical conductivities of samples are determined by DC four probes.Furthermore,thermal expansion coefficients of these compositions are measured.The results indicate that the synthesized samples are single perovskite phase,the diffraction peak shifts towards high angle as Sr content increases.The electrical conductivity reaches a maximum value as increasing temperature and Sr content,according to analysis,the reason is that small polaron hopping mechanism dominates the electron conduction at low temperature,while the charge compensation of oxygen vacancies at thigh temperature.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2004年第3期382-385,共4页
Journal of Materials Science and Engineering
基金
南京理工大学科研发展基金项目 :AB960 55
