Failure Analysis of Garnet-Type Solid State Electrolyte LLZO by Electrochemical Method

摘要

Garnet-type Li_7La_3Zr_2O_(12) (LLZO) is one of the most attractive candidates for achieving solid state lithium batteries. LLZO pellet is preferred due to its potential to prevent dendritic lithium growth and penetration. However, lithium dendrite can penetrate the LLZO pellets in a low current density, resulting in short circuit of the cell. In this work, we study the failure behavior of LLZO electrolyte through electrochemical method. Meanwhile, we also study the growth of lithium inside the LLZO pellet after failure. The results show that the reason for failure of LLZO is related to the contact between lithium and LLZO, and lithium dendrite may grow from one to another electrode.