摘要
通过X射线衍射(XRD)、热重、热膨胀、电导率以及电化学交流阻抗等测试技术研究了SmSr1-xAexCo2O6(x=0,0.2,0.4,0.6,0.8,1;Ae=Ca,Ba)作为中低温固体氧化物燃料电池(IT-SOFC)阴极的结构与性能.研究表明,固相法合成的SmSr0.8Ae0.2Co2O6(Ae=Ca,Sr,Ba;简写为SSAC)随着Ca、Ba掺杂量的增大晶体结构发生变化.其中,空间群为Pnma晶体结构的电极SSAC中,晶胞参数随着Sr、Ca、Ba的顺序增大;SSAC晶体中的氧空位浓度随着Ca、Sr、Ba的顺序增大,SSAC热膨胀系数与Ae元素关系不大,氧催化性能随着Ca、Sr、Ba的顺序降低.由于载流子浓度降低,使得Ba掺杂Sm0.5Sr0.5CoO3(SSC)后电极的电导率降低.由于导电活化能增大,使得Ca掺杂SSC后电极的电导率也降低.
The structure and performance of SmSr1-xAexCo2O6（x=0,0.2,0.4,0.6,0.8,1;Ae=Ca,Ba） as intermediate temperature-solid oxide fuel cell（IT-SOFC） cathodes were investigated by X-ray diffraction（XRD）,thermogravimetry（TG）,thermal expansion,electrical conductivity,and electrochemical impedance spectroscopy（EIS）.The SmSr1-xAexCo2O6 system＇s structure changes as x increases from 0 to 1.The SmSr0.8Ae0.2Co2O6（SSAC;Ae=Ca,Sr,Ba） system has an orthorhombic structure with a Pnma space group.The crystal parameter of SSAC increases in the following order：Sr〈 Ca〈Ba.The oxygen content increases in the following order：Ca〈Sr〈Ba while the electrocatalytic activity decreases.The thermal expansion coefficients of SSAC with different Ae elements are similar.The electrical conductivities of Sm0.5Sr0.5CoO3（SSC） doped with Ba and Ca decrease because of a decrease in the carrier concentration and an increase in the conduction activation energy,respectively.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2009年第11期2211-2217,共7页
Acta Physico-Chimica Sinica
