Sol-gel法合成La_(0.8)Sr_(0.2)Co_(1-y)Fe_yO_3及其电性能研究

Study on preparation and electrical property of La_(0.8)Sr_(0.2)Co_(1-y)Fe_yO_3 by sol-gel method

采用溶胶-凝胶法合成中温固体氧化物燃料电池阴极材料La0.8Sr0.2Co1-yFeyO3,通过热重-差热分析法(TG-DTA)、X射线衍射光谱法(XRD)分析了合成过程,在800℃焙烧2h得到完整的晶体。通过直流伏安法和交流阻抗法研究了材料的电子电导率和离子电导率;在700℃时,La0.8Sr0.2Co0.5Fe0.5O3的电子电导率和离子电导率分别为386S/cm和0.0013S/cm;La0.8Sr0.2Co0.9Fe0.1O3的电子电导率和离子电导率分别为650S/cm和0.042S/cm,能够满足中温燃料电池要求。La0.8Sr0.2Co1-yFeyO3电极过程是由O2-离子界面反应所控制。

La0.8Sr0.2Co1-yFeO3 powders for IT-SOFC＇s cathode were prepared by sol-gel method. Process of perovskite phase was investigated by TG-DTA, XRD, The single phase of LSCF perovskite obtained at 800 ℃ for sintering 2 h.Electronic conductance and ionic conductance were investigated by DC volt-ampere and EIS.The results show that electronic conductance and ionic conductance of La0.8Sr0.2Co1-yFeO3 are 386 S/cm and 0.001 3 S/cm at 700 ℃, respectively.While La0.8Sr0.2Co1-yFeO3 are 650 S/cm and 0.042 S/cm .The process of La0.8Sr0.2Co1-yFeO3 electrode is controled by formation, exchange and ruduction of O^2-.