用于固体氧化物燃料电池的Zn掺杂BaZr0．7Pr0．1Y0．2O3-δ质子导体电解质的制备与性能

Preparation and Properties of Zn Doped BaZr_(0.7)Pr_(0.1)Y_(0.2)O_(3-δ) Proton-Conducting Used for Solid Electrolytes Oxide Fuel Cells

采用柠檬酸–硝酸盐燃烧法制备了质子导体固体氧化物燃料电池(SOFC)电解质材料BaZr0.7Pr0.1Y0.2O3–δ(BZPY)和BaZr0.7Pr0.1Y0.16Zn0.04O3–δ(BZPYZn)。研究了Zn掺杂对材料烧结、热膨胀系数和电性能的影响;利用X射线衍射仪和扫描电子显微镜对样品物相和微观结构进行了表征。结果表明:BZPYZn经1 100℃煅烧5h后呈单一的钙钛矿结构。随烧结温度的升高(从1 300℃到1400℃),BZPYZn陶瓷体的晶粒尺寸增大,而孔隙率减小;1350℃保温5h烧结的BZPYZn陶瓷样品的相对密度达到97.3%;500～800℃范围内,离子电导率介于10–3～10–2S/cm之间。室温至1 000℃范围内,样品的热膨胀系数为9.2×10–6/K,表明其与电极材料(Ni)的热匹配性好。预示BZPYZn有望成为良好的质子传导型中温SOFC电解质材料。

BaZr0.7Pr0.1Y0.2O3-δ（BZPY） and BaZr0.7Pr0.1Y0.2O3-δ （BZPYZn） proton-conducting solid oxide fuel cells （SOFC） electrolytes were synthesized by a citrate-nitrate combustion method. The influence of Zn doped on the sintering, coefficient of thermal expansion （TEC） and electrical properties of sample were investigated. The phase and microstructure of the sintered samples were characterized by X-ray diffraction and scanning electron microscope, respectively. The results showed that BZPYZn exhibits a single perovskite structure after the calcination at 1 100 ℃ for 5 h. With increasing of sintering temperatures （from 1 300 ℃ to 1400 ℃）, the grain size of BZPYZn ceramic sample increases, and porosity decreases. The high relative density of 97.3% is obtained for the BZPYZn sample sintered at 1 350 ℃ for 5h. The BZPYZn sample exhibit a high ionic conductivity （10^（-3）to 10^（-2） S/cm） at 500-800 ℃. The average TEC of the BZPYZn is 9.2 × 10^（-6）/K from room temperature up to 1 000 ℃, which fits well with those of electrode materials （e.g. Ni）. It is indicated that BZPYZn is a promising candidate as a stable and easily sintered electrolyte for intermediate- temperature SOFC.