CeO2基-非化学计量LaGaO3基复合电解质的界面调控及导电性能

项目名称： CeO2基-非化学计量LaGaO3基复合电解质的界面调控及导电性能

项目编号： No.21471022

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 周德凤

作者单位： 长春工业大学

项目金额： 85万元

中文摘要： 界面结构影响氧离子的输运与存储。利用多晶材料的晶界特性和复合材料的界面效应，控制晶界/界面的组成、结构和缺陷，探索其构效关系是材料科学研究的重要课题。本项目针对钙钛矿LaGaO3材料中A位和B位的非化学计量对晶体结构、能带及缺陷的影响，利用第一性原理进行计算。采用多种方法将不同颗粒尺寸、不同质量比及不同非化学计量LaGaO3基材料引入CeO2基电解质，考察其对高纯/非纯CeO2基电解质的晶界相、空间电荷层效应、烧结致密化和电性能的影响。利用LaGaO3基非化学计量对微结构的调变、CeO2和LaGaO3两相结构的差异及纳米复合的理念调控复合电解质的界面结构；明确异质界面离子单/双向扩散的驱动因素及杂质离子在晶界或晶粒内分布；控制界面化合物及缺陷的形成与演变规律。探索改进和优化实验条件及材料的烧结工艺，制备纳米化致密复合陶瓷。旨在降低材料的晶界/界面电阻，获得高性能的复合氧化物电解质材料。

中文关键词： 非化学计量；界面调控；固体电解质；晶界

英文摘要： Interfacial structure has an significant influence on oxygen-ion transport and storage. To manipulate the compositions, structures and chemical defects of grain boundary/interface by using grain-boundary effect of the polycrystalline materials and interfacial effect of the composite materials, and explore its structure-activity relationships are important subjects in material area. In this project, we perform the first principles calculations of the effects of A- and B-site non-stoichiometry on crystal structures, bands and oxygen defects in LaGaO3(ABO3) perovskite materials. The LaGaO3 based materials with different particle sizes, contents and non-stoichiometries are introduced into CeO2 based electrolytes by several approaches, and its effects on grain boundary phases, space charge layers, sintering densification and electrical properties of the high-pure/impure CeO2 based electrolytes are investigated. Our efforts are manipulate the interfacial structure of composite electrolyte from three aspects that including the nonstoichiometry modulation to microstructure in LaGaO3, the structure differences between the CeO2 and LaGaO3 phases, and the concept of nanocomposite electrolyte. We clarify the driving factors of the ionic single/double diffusion by hetero-interfaces, and the impurity ionic distribution among the the grain boundary or grain interior. We attempt to manipulate the formation and evolution processes of the compounds and defects in interfaces. The optimum experimental condition and sintering process are explored to prepare the nano dense composite ceramics. Our ultimate aim is to effectively reduce the grain boundary/interface resistances, and obtain high performance composite oxide electrolyte materials.

英文关键词： Nonstoichiometry;Interface manipulation;Solid electrolyte;Grain boundary