Synthesis Characteristics of Garnet-Llzo Materials By Modified Co-Precipitation

Abstract

Recently, many sorts of lithium batteries have been studied such as all solid and lithium-air batteries etc., for EV and ESS applications. Especially, all solid battery is one of the candidates for a large-sized battery in regard of the safety problem. Garnet-type LLZO electrolyte has good advantages with a high ionic conductivity and electrochemical potential window. However, it is reported that there are difficulties to prepare LLZO(Li7La3Zr2O12) pellets with high relative density. In this study, LLZO material was doped by the different elements of Al by co-precipitation process. Furthermore, we studied the effects of lithium excess concentration of Al-doped LLZO. We investigated not only the change of cubic and tetragonal structure but also electrochemical properties according to the synthesis conditions. As a result, ionic conductivity of Al-doped LLZO material was about 3.1x10-4 S/cm at room temperature, indicating a wide electrochemical window of 0~5.5V. Furthermore, we will introduce the electrochemical properties of unit cell using LLZO material in more detail.