摘要
采用柠檬酸-硝酸盐自蔓延燃烧法合成了中温固体氧化物燃料电池阴极材料La_(1-x)Ba_(x)FeO_(3-δ)(LBF)(x=0,0.1,0.2,0.3,0.4,0.5)。通过X射线衍射(XRD)、直流四端引线法和热膨胀仪分别对LBF的晶体结构、电导率和热膨胀系数进行了研究,分析了Ba掺杂量对材料性能的影响。同时制备了电解质Gd_(0.1)Ce_(0.9)O_(2-δ)(GDC),构建对称电池LBF/GDC/LBF并进行了电化学性能测试,用扫描电子显微镜观察(SEM)对称电池的断面微结构,交流阻抗谱测试极化阻抗。结果表明,合成的阴极材料LBF均为钙钛矿结构,A位Ba掺杂提高了材料的电导率,同时增大了材料的热膨胀系数,改善了阴极材料与电解质GDC的热膨胀匹配性。SEM结果显示对称电池具有理想的微观结构,阴极与电解质之间的界面展现出良好的烧结结合;电化学交流阻抗分析结果表明,A位Ba掺杂可以降低阴极的极化电阻,当Ba^(2+)掺杂量为x=0.4时,LBF-0.4具有最小的极化电阻,在800℃空气气氛下极化电阻为0.127Ω·cm^(2),电荷转移阻抗是电池极化阻抗的主要来源。实验结果表明LBF材料是一种电化学性能较为优良的中温固体氧化物燃料电池(IT-SOFC)阴极材料。
As a promising energy conversion device,solid oxide fuel cell(SOFC)has become one of the most promising green energy sources in the future due to its high efficiency,low pollution,high energy conversion rate,strong fuel adaptability and environmental friendliness.The traditional SOFC operated at 800~1000℃,which lead to the problems of unsuitable thermal matching between mate‐rials and instability of electrode.At the same time,the cost of battery operating at high temperature is high and the material selection was difficult.The exploration of cathode materials with good electrocatalytic activity and low-cost at intermediate temperature(600~800℃)is crucial for improving the performance of solid oxide fuel cells(SOFC).LaFeO_(3)with perovskite structure as cathodes have at‐tracted researchers’interest due to the advantages of high ionic conductivity,good chemical and thermal stability and low cost.In this paper,LaFeO_(3)(LF)was used as the research object,which was modified by single doping of A-sites.Cathode materials La_(1-x)Ba_(x )FeO_(3-δ)(LBF)(x=0,0.1,0.2,0.3,0.4,0.5)of medium-temperature solid oxide fuel cell were synthesized by a citric acid-nitrates self-prop‐agating combustion method.The crystal structure,electrical conductivity and thermal expansion coefficient of the LBF cathode materi‐al were studied by X-ray diffraction(XRD),direct current four-terminal method and thermal dilatometer,respectively.And the ef‐fects of Ba-doping on performance and properties of materials were analyzed.The solid electrolyte Gd_(0.1)Ce_(0.9)O_(2-δ)(GDC)was prepared using the same method simultaneously,and a symmetrical cell of LBF/GDC/LBF was fabricated and the electrochemical performance of the cell was analyzed.The cross-section microstructure and polarization of the symmetrical cell were detected using a scanning elec‐tron microscope(SEM)and AC impedance spectroscopy.XRD results showed that the undoped LaFeO_(3)was judged to have formed a single orthorhombic perovskite structure.Two phases of LaFeO_(3)a
作者
王竹梅
冯晓霞
谢志翔
李月明
Wang Zhumei;Feng Xiaoxia;Xie Zhixiang;Li Yueming(School of Materials Science and Engineering,Jingdezhen Ceramic Institute,Jingdezhen 333403,China;China National Light Industry Key Laboratory of Functional Ceramic Materials,Jingdezhen 333403,China;Energy Storage and Conversion Ceramic Materials Engineering Laboratory of Jiangxi Province,Jingdezhen 333403,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2021年第10期1192-1199,共8页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51402136)
江西省自然科学基金项目(20171BAB216008)
江西省教育厅项目(GJJ180707)资助。
