DFT Electronic Properties and Synthesis Thermodynamics of Li <sub> <i>x</i> </sub> La <sub> 1− <i>x</i> </sub> TiO <sub>3</sub> Electrolytes for Li-Ion Batteries
J. M. Cervantes, J. Pilo, J.L. Rosas-Huerta, J. E. Antonio, H. Muñoz, Raúl Oviedo‐Roa, E. Carvajal
Abstract
Lithium lanthanum titanate perovskites Li x La 1− x TiO 3 (LLTO) are promising solid-electrolytes for Li-ion batteries. We studied, in the Density-Functional-Theory framework, the thermodynamic stability and the electronic and magnetic properties of LLTO, as bulk materials and as thin slabs with (001) exposed surfaces. Results show that LaTiO 3 (LTO) exhibits semiconductor behavior and G-type antiferromagnetic order (AFM G ), whereas the TiO 2 -terminated LTO slab is a semiconductor with ferromagnetic (FM) order. Contrasting, the LTO slab exposing a LaO-terminated surface is a conductor with AFM G ordered Ti cations' magnetic moments (MMs), but at the surface there are some FM ordered MMs (La atoms). LLTO bulk electrolyte is a semiconductor ( x = 0.25) or insulator ( x = 0.50). The LLTO slab is a FM (non-magnetic) conductor (TiO 2 (LiO)-terminated surface) or a FM semiconductor (LaO-terminated). Besides, the stability of the LLTO bulk and slabs structures was analyzed, as well as the slabs’ preferences for LiO, LaO or TiO 2 ends.