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[18p-432-2] First Principles Analysis of Li diffusion in Li₇TaO₆ Solid State Electrolytes

〇Minoru Ikeda¹, Takahisa Ohno¹, Kazutaka Mitsuishi¹, Yosuke Hamasaki², Koichiro Ueda², Yoshiyuki Inaguma² (1.NIMS, 2.Gakusyuin Univ.)

Keywords:Solid state electrolyte, First principles calculations, all solid state Li ion secondary battery

Hexaoxomentalates Li₇MO₆ (M=Nb, Ta, Sb, Bi) solid state electrolytes show different conductivity dependig on the Low temperature phase (LT) and High temperature phase (HT). These crystal strucures are mainly composed of isolated octahedrons which include Ta and surrounding many Li atoms. As these systems contain quite rich concentrations, it is interesting materials from application side. According to the experiments, its space group symmetry is Rhombohedral R-3 for HT, whereas Triclinic P-1 for LT phase. In this report, we investigate the Li₇TaO₆ system using the first principles calculations. We analyzed the thermal properties and Li diffusion process for both LT and HT phases.