In recent years, cubic lithium garnets, Li7La3Zr2O12 (LLZO) in particular, have attracted much attention due to reasonable ionic conductivity (>10-4 S cm-1 at room temperature), good chemical stability with lithium metal, and near-to-unit transference number. It has been reported that small amount of Al2O3 dopant can act as sinter aid to yield dense and cubic phase, the fast Li-ion conducting phase. This talk first introduces our efforts to synthesize such lithium garnets. We investigated the effect of preparation parameters including Al2O3 doping amount, crucibles, and heating schedule on the materials properties such as ionic conductivity and air stability, using various characterization techniques such as XRD, ICP-OES, SEM-EDS, NMR, Raman and EIS. We optimized the preparation process and obtained lithium garnets with good air stability and room-temperature conductivity in the range of 4~6 x 10-4 S cm-1 . Then the reaction mechanisms of LLZO in ambient air are discussed [2,3,4]. This talk ends with the applications of LLZO in novel lithium batteries such as solid lithium batteries, hybrid lithium battery and Li-S batteries [5,6].
 Biyi Xu, Huanan Duan, Wenhao Xia, Yiping Guo, Hongmei Kang, Hua Li, Hezhou Liu, Journal of Power Sources, 302 (2016) 291-297.
 Wenhao Xia, Biyi Xu, Huanan Duan, Yiping Guo, Hongmei Kang, Hua Li, Hezhou Liu, ACS Appl. Mater. & Interfaces, 8 (2016) 5335-5342.
 Wenhao Xia, Biyi Xu, Huanan Duan, Xiaoyi Tang, Yiping Guo, Hongmei Kang, Hua Li, Hezhou Liu, Journal of the American Ceramic Society (2017) 1-8.
 Huanan Duan, Hongpeng Zheng, Ying Zhou, Biyi Xu, Hezhou Liu, accepted by Solid State Ionics.
 Biyi Xu, Wenlong Li, Huanan Duan, Haojing Wang, Yiping, Guo, Hua Li, Hezhou Liu, Journal of Power Sources 354 (2017) 68-73.
 Biyi Xu, Huanan Duan, Hezhou Liu, Chang-An Wang, Shengwen Zhong, ACS Applied Materials & Interfaces 9 (2017) 21077-21082.