基于阻抗模型解析的氧化锆固体电解质组织结构演变模型

晶界对多元多晶电解质材料电导率的影响, 已成为制约高温固体电解质材料发展的瓶颈. 传统的晶界观察方法难以将高温下材料的组织结构与电导性能相对应. 鉴于此, 本文研究了部分稳定氧化锆(PSZ) 固体电解质材料的变温交流阻抗特性, 并对交流阻抗谱进行了拟合分析, 发现等效拟合电路随温度的上升而发生变化. 通过对不同等效电路模型的物理解析, 得出PSZ电解质材料显微结构在高温下的演变模型. 经进一步分析, 演绎出一种'短程有序'的'晶界桥接'组织模型, 为改善PSZ电解质材料的晶界电导提供了参考.

Microstructure evolution model of zirconia solid electrolyte based on AC impedance model analysis

The effect of grain boundary on conductivity in multicomponent polycrystalline solid electrolyte has become a bottleneck for the development of high temperature solid electrolyte materials. The corresponding relationship between the microstructure and conductivity at high temperature is difficult to obtain based on the traditional methods of grain boundaries observation. In view of this, the variable temperature AC impedance characteristics of partially stabilized zirconia (PSZ) solid electrolyte material are investigated, and their fitting to AC impedance spectrum is analyzed. It is found that the fitting equivalent circuits varies with temperature increasing. By analyzing the physical meanings of different equivalent circuits, the microstructure evolution model of PSZ electrolyte material at elevated temperature is obtained. A microstructure model of 'short-range ordered ' with the structure of 'boundary bridge' is deduced after further analysis, which could provide the reference for improving the grain boundary conductivity in PSZ electrolyte materials.