固态锂离子传导氧化物中的点缺陷  

Point defects in solid-state lithium ion conducting oxides

作　　者：吴剑芳[1] 郭新[1] 

机构地区：[1]华中科技大学材料科学与工程学院固态离子学实验室,湖北武汉430074

出　　处：《储能科学与技术》2016年第5期745-753,共9页Energy Storage Science and Technology

摘　　要：固态电解质能有效地解决液态电解质存在的易燃、易泄漏及化学稳定性差等问题,然而,固态电解质的锂离子电导率（10-5~10-3 S/cm）显著低于液态电解质电导率（10-2 S/cm）,导致全固态锂离子电池的充放电性能比液态电池差。因此,进一步提高固态电解质的锂离子电导率成为改善全固态电池性能的关键,认知并调控材料中的点缺陷对于改善锂离子电导具有重要意义。本研究团队选用两种重要的固态锂离子传导氧化物材料：具有钙钛矿结构的Li3xLa（2/3-x1/3-2x）TiO3（0.04≤x≤0.16）和具有石榴石结构的Li7La3Zr2O12为研究对象,对其中存在的点缺陷及缺陷反应进行分析,并进一步阐述各种点缺陷对材料锂离子、氧离子和电子电导率的影响。Solid electrolytes do not have the common shortcomings of liquid electrolytes, such as flammability, leakage and low chemical stability. However, solid electrolytes also have a big disadvantage of relatively low lithium ion conductivity of 10^-5~10^-3 S/cm, as compared with the conductivity of liquid electrolytes （10^-2 S/cm）. Therefore, the properties of all-solid-state lithium ion batteries based on solid electrolytes are normally rather poor. To increase the lithium ion conductivity of solid electrolytes is a key issue for improving the performance of all-solid-state lithium ion batteries As a matter of fact, point defects determine the lithium ion conductivity of oxides. To modulate the defect structure of lithium ion conducting oxides is an effective way to enhance the lithium ion conductivity. In this work, two oxides, i.e. perovskite Li3xLa2/3-x1/3-2xTi03 （0.04≤x≤0.16） and garnet Li7La3Zr2O12 are evaluated from the point of view of defect chemistry, and the contributions of various defects to the lithium ion conductivity, the oxygen ion conductivity and the electronic conductivity are elucidated.

关 键 词：固态电解质 缺陷 锂离子电导率 氧离子电导率 电子电导率 

分 类 号：TM912[电气工程—电力电子与电力传动]