电解质表面微结构对固体氧化物燃料电池的阴极极化电阻的影响  

Effect of Electrolyte Surface Microstructure on Interfacial Polarization Resistances of Solid Oxide Fuel Cell Cathodes

作　　者：宋书祥[1] 王云龙[1] 夏长荣[1] 

机构地区：[1]中国科学技术大学材料科学与工程系&苏州纳米科技协同创新中心、中国科学院能量转化重点实验室,合肥230026

出　　处：《无机材料学报》2014年第12期1253-1256,共4页Journal of Inorganic Materials

基　　金：科技部973项目(2012CB215403);国家自然科学基金(51372239)~~

摘　　要：在固体氧化物燃料电池(SOFC)中,电解质对阴极界面极化电阻(Rc)有着显著影响。通过测量以Sm0.2Ce0.8O2-δ(SDC)为电解质、(La0.85Sr0.15)0.9Mn O3-δ(LSM)和La0.6Sr0.4Fe0.8Co0.2O3-δ(LSCF)为阴极的对称电池的交流阻抗谱,研究SDC电解质表面微结构(晶粒大小和晶界长度)对Rc的影响。通过改变烧结温度和时间,制备出具有不同晶粒尺寸和晶界密度的电解质。通过SEM得到微结构参数,建立Rc与这些参数的联系。结果发现,随着晶粒尺寸的减小、晶界密度的增加,Rc明显降低。此外,对于LSM电极,晶界密度的增加,促进了阴极反应的氧离子传导。The interfacial polarization resistance （Re） associated with cathode in solid oxide fuel cell （SOFC） isaffected by the electrolyte conductivity. In this work, the effect of electrolyte surface microstructure on the cathode performance was demonstrated by analyzing electrochemical impedance spectra of symmetric cells which consist of porous （La0.85Sr0.15）0.9MnO3-δ（LSM） and La0.6Sr0.4Fe0.8Co0.2O3-δ （LSCF） electrodes with Srn0.2Ce0.8O2-δ （SDC） electrolytes. The SDC electrolytes exhibited different surface microstructures, i.e. different grain sizes and grain boundary densities as a result of various sintering conditions. SEM was used to investigate the SDC surface micro- structure parameters and the relationships between these parameters and the polarization resistance ware discussed. It is found that Rc is greatly affected by the SDC surface microstructures and decreases with the decrease of grain size, or the increase of grain-boundary density. Moreover, it is demonstrated that the oxygen ion transfer is signifi- cantly increased by decreasing grain size for the oxygen reduction at the LSM cathode.

关 键 词：阴极 极化阻抗 晶界密度 电解质微结构 固体氧化物燃料电池 

分 类 号：TQ174[化学工程—陶瓷工业]