中温SOFC用LaGaO_3基固体电解质的制备

Preparation of LaGaO_3 based electrolyte for intermediate temperature SOFC

采用固相反应法成功制备了镓酸镧基固体电解质粉体(La0.9Sr0.1Ga0.8Mg0.2O3-δ),X射线衍射分析表明,经1 500 ℃煅烧24 h合成粉体为单相结构,并讨论了煅烧时间、煅烧温度对粉体物相的影响。测试结果表明,粉体的平均粒径为1 μm;粉体经过1 500 ℃下烧结15 h,得到相对密度为99%的陶瓷,采用交流阻抗测试电导率,800 ℃时离子电导率为0.12 S/cm,且高温下(≥650 ℃)活化能为0.8 eV,低温下(≤650 ℃)为1.09 eV。

The electrolyte La0.9Sr0.1Ga0.8Mg0.2O3-δ was prepared by the method of solid-state reaction. X-ray diffraction was used to characterize phase transition with the temperature. Test results show that the pure phase is formed by sintering 24 h at 1 500 ℃. The effect of calcine temperature and time were discussed. The powder granularity is 1 μm; and after sintering 15 h at1 500 ℃, the relative density of ceramic can reach 99%. The conductivity was measured by AC impedance. The result was 0.12 S/cm at 800 ℃. The active energy was 0.8 eV at high temperature (≥650 ℃) and 1.09 eV at lower temperature (≤650 ℃) respectively .