[17p-419-1~10] 6.3 Oxide electronics

[17p-419-10] First Principles Analysis of Li Diffusion in LiZr₂(PO₄)₃ Solid State Electrolytes

〇Minoru Ikeda¹, Takahisa Ohno¹, Kazutaka Mitsuishi¹, Yoshiyuki Inaguma², Koki Funayama², Daisuke Mori² (1.NIMS, 2.Gakusyuin Univ.)

Keywords:Solid State Electrolyte, First principles calculations, Li ion secondary battery

We studied LiZr2(PO4)3 solid state electrolyte with a NASICON type which was used as the Li ion secondary battery. LZPO has two crystal structures such as alpha' phase (Low temperaure) and alpha phase (High temperature). LZPO shows phase transition from alpha' to alpha phase at 300K. The alpha phase takes R-3c space group symmetry and shows high ion conductivity. However, its Li ion propagation path was not reported clearly. Therefore we investigated Li ion propagation path and its activation energy for alpha-LZPO using the first principles calculations. By analyzing the trajectories of Li generated by the molecular dynamics simulations during 300 ps at 1600K, Li ion exists one 36 f site and moved to the nearest neighbour 36 f site by hopping. The maximum number of one 36 f site occupacy is 2. According to our NEB calculation, its activation energy is 0.64 eV.