La掺杂SrTiO_3阳极材料性能研究

Properties of La-doped SrTiO_3 anode materials for solid oxide fuel cells

以碳氢化合物为燃料直接电化学氧化是目前固体氧化物燃料电池(SOFC)的发展方向,寻求新的阳极材料是其发展的关键。采用固相法合成了La掺杂的钛酸锶Sr1-1.5xLaxTiO3(x=0.1,0.2,0.3,0.4,0.5)钙钛矿复合体系氧化物,对合成产物的结构、烧结性能、高温电导性能进行了测定,研究了不同La掺杂量对阳极材料电导率的影响,通过X射线衍射(XRD)分析研究了掺杂钛酸锶阳极材料与YSZ电解质的相容性。研究结果表明,从600～800℃,Sr1-1.5xLaxTiO3电导率随温度的升高呈现单调降低趋势,当x=0.3时电导率最高,在800℃时达到103.5S/cm,在1400℃下和YSZ电解质有良好的化学相容性。

Direct electrochemical oxidation of hydrocarbon fuels is the current development trend of the solid oxide fuel cells （SOFCs） and it is a key issue to find a new kind of anode materials for this usage. In this work, the La2O3 doped SrTiO3 perovskite compounds Sr1-1.5xTiO3 （x=0.1, 0.2, 0.3, 0.4, 0.5） were synthesized by solid-state reaction. The structure of the calcined powders was examined. The sinterability of the anode materials was detected by Archimedes principle and high temperature conductivity was measured via 4-probe DC method. The influences of different La2O3 contents on the electrical conductivities were determined and the conductance mechanism was discussed. The chemical compatibility of the anode materials with YSZ electrolyte was examined by XRD analysis. The results indicated that from 400 ℃ to 1 000 ℃, the conductivity decreased with increasing temperature. The highest conductivity appeared at 800℃, reaching 103.5 S/cm when x=0.3; and the materials had good chemical compatibility with YSZ electrolyte when sintered at 1 400 ℃.