Misconception in the analysis of Tetragonal Li sub(7)La sub(3)Zr sub(2)O sub(12) Garnet

Abstract

Li sub(7)La sub(3)Zr sub(2)O sub(12) (LLZO) is a fascinating solid electrolyte material that is widely preferred for solid-state batteries. LLZO exists in two crystal polymorphs, namely, tetragonal and cubic. The analysis of the reported tetragonal crystal structure, where the third Li atom is described as "distorted octahedra", is found to be erroneous, and the corresponding bond lengths of Li-O are unrealistic in the literature. These inaccuracies could lead to misconceptions about LLZO's ionic conduction behavior. To rectify this misconception, a correct analysis of the tetragonal LLZO crystal structure has been conducted. The corrected analysis provides a more accurate understanding of the coordination of Li and the corresponding bond lengths. Furthermore, a bond valence site energy analysis has been performed to understand the Li-ion migration pathway in LLZO. This analysis helps to elucidate the energies of Li-ion migration within the crystal lattice, providing valuable insights into the mechanisms underlying the ionic conduction process. This correction is of significant technological importance as it helps to establish a reliable foundation for studying the Li-ion migration pathways.