Effect of Stress State on Phase Stability and Ionic Transport in the Solid Electrolyte Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub>
Scott Monismith, Jianmin Qu
Abstract
In recent years, Li7La3Zr2O12(LLZO), a garnet-type solid oxide, has gained considerable attention as an alternative electrolyte material to conventional liquid electrolytes due to its high ionic conductivity (10–4 S cm–1) and stability with respect to metallic lithium. This study employs classical molecular dynamics simulations to probe the relationship between the applied stress state and lithium ion dynamics in single-crystal LLZO. It is found that the activation energy experiences a decrease under hydrostatic tension and an increase under hydrostatic compression. When the crystal is mechanically distorted under a uniaxial load in the x-direction, the material exhibits a cubic-to-tetragonal phase change; this change occurs at 1000 K tested under tension and at most temperatures tested under compression.