Energy Storage Science and Technology ›› 2016, Vol. 5 ›› Issue (5): 745-753.doi: 10.12028/j.issn.2095-4239.2016.0035

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Point defects in solid-state lithium ion conducting oxides

Wu Jianfang, Guo Xin   

  • Received:2016-07-01 Revised:2016-07-27 Online:2016-09-01 Published:2016-09-01

Abstract: 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x□1/3-2xTiO3 (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.

Key words: solid electrolyte, defects, lithium ion conductivity, oxygen ion conductivity, electronic conductivity