【作者】 潮洛蒙；

【导师】 丁铁柱；

【作者基本信息】 内蒙古大学 ， 凝聚态物理， 2009， 硕士

【摘要】 固体氧化物燃料电池（SOFC）具有能源综合利用率高、运行无污染等突出优点,是一种极具发展前景的新型能源转换系统,将运行温度降低到中温范围（600-800℃）是当前SOFC的一个主要发展方向。阴极材料是SOFC的重要组件。若降低SOFC的运行温度,将引起阴极的极化过电位增加、界面电阻增大。因此,研制与电解质材料匹配性良好的新型阴极材料是发展中温SOFC的前提和基础。本文采用固相反应法合成了(La_1-xPr_x)_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ（x=0.2,0.4,0.6,0.8）钙钛矿氧化物系样品,用XRD,Raman光谱等分析手段研究了其物相结构,用电导驰豫法研究了(La_1-xPr_x)_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ系样品的氧化学扩散性能。实验结果表明:其主结构为钙钛矿结构,随着Pr含量的增加其晶胞内的CoO₆八面体发生了畸变,其结构转变为以钙钛矿结构为主的两相共存结构。(La_1-xPr_x)_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ系样品的电导率随氧分压的增大而增大;氧化学扩散系数D_chen随温度的减小、Pr含量的增加而线性下降,在高氧分压下,D_chen,随末态氧分压的变化不大;(La_0.8Pr_0.2)_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ样品的氧扩散系数最大,在600℃时达到9.41×10^-5cm²·s^-1,是比较理想的中温固体燃料电池阴极材料。更多还原

【Abstract】 Solid oxide fuel cell was a highly promising new energy conversion system which integrated with highlighting advantages such as energy-efficient, pollution-free. The operating temperature down to medium temperature range （600-800℃） are the major development direction of current study on SOFC.Cathode materials are the essential components of SOFC. It should cause the increasing of polarization overpotential and interfacial resistance If lowering the operating temperature of SOFC. Therefore, develop new type of cathode materials which good matching at electrolyte material was the premise and foundation of develop IT-SOFC.In this article, perovskite oxides of (La_1-xPr_x)_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ（x= 0.2,0.4,0.6,0.8） samples were obtained by solid state-reaction method. The phase structure was analysed by XRD and Raman spectrum, the oxygen chemical diffusion properties was determined by electrical conductivity relaxation technique. The resultes show that dominant phase structure of LPSCF systems is perovskite structure, the octahedral CoO₆ was some distorted with increasing of content Pr, It is reflections of the presence of different secondary phase. the conductivity of (La_1-xPr_x) （0.6）Sr_0.4Co_0.8Fe_0.2O_3-δincreases with increasing of oxygen partial pressure. The(La_1-xPr_x)_0.6Sr_0.4Co_0.8Fe_0.2O_3-δsamples have higher oxygen chemical diffusion coefficients, which decrease linearity with the decreasing of temperature and increasing of content Pr. The oxygen chemical diffusion coefficients D_chen remains fairly constant at high PO₂. The oxygen chemical diffusion coefficients was highest at x=0.2, which achieved 9.41×10^-5cm²·s^-1 at 700℃, is comparatively potential cathodes material for intermediate temperature solid oxide fuel cells.更多还原