氧化钇掺杂锆铈酸钡质子导体的制备及性能研究

采用高温固相法制备了钇掺杂锆铈酸钡(BaZr_0.90-xCe_xY_0.10O_3-δ, x=0.09、0.18、0.27)(即BZCY系列)前驱体粉末, 研究了烧结性能和电导率. 结果表明, 在所研究的组成范围内, x=0.27(即C3)试样为最佳. 再进一步通过优化烧结助剂ZnO添加量以提高试样的烧结性能及电化学性能. 实验表明, ZnO能够与前驱体发生固溶取代反应, 有效地提高了样品烧结性能. 随着ZnO添加量的增加, 试样烧结致密度提高, 但直流电导率先增大后减小. 当ZnO添加量为2mol%(C3-Z2)时, 试样具有最高的直流电导率, 800℃在湿H₂中电导率可达9.27 mS/cm. C3-Z2试样的XRD衍射峰与BaCeO₃、BaZrO₃标准衍射峰相比出现一定角度的偏移, 而与BaCe_0.4Zr_0.6O₃的标准图谱相对吻合较好.

Preparation and Properties of Yttrium Doped Barium Zirconate-cerate Proton Conductors

Yttrium doped barium zirconate-cerate (BaZr_0.90-xCe_xY_0.10O_3-δ, x=0.09, 0.18, 0.27, BZCY) powders were synthesized by the conventional solid state reaction route. The x value was optimized to be 0.27 in the composition range. That is to say, the sample with x=0.27 had the best sinterability and conductivity among the three composites. The sintering behavior and electrical conductivity could be further improved by optimizing the addition content of ZnO sintering aid. ZnO was able to form a solid solution with BZCY, resulting in the enhancement of sinterability. As increasing the amount of ZnO, density of the sintered samples increased. However, conductivity did not increase monotonously with the addition of ZnO. When the content of ZnO was 2mol% (C3-Z2), the sample had the highest DC conductivity, reaching 9.27 mS/cm at 800℃ in wet H₂ atmosphere. A small shift of the main peaks of the XRD pattern for the sample C3-Z2 was clearly observed compared with the standard patterns for BaCeO₃ and BaZrO₃. The XRD pattern of the sample C3-Z2 was in a good agreement with that of BaCe_0.4Zr_0.6O₃ sample.