Effect of Li 2 O excess in Li 6.4 Ga 0.2 La 3 Zr 2 O 12 electrolyte for all‐solid‐state Li‐ion batteries

Abstract Li 7 La 3 Zr 2 O 12 is a promising material used as solid electrolyte in all‐solid‐state lithium batteries. However, the lithium ionic conductivity of LLZO is limited, and the cycling stability of lithium symmetric battery based on LLZO is not good. In this research, different Ga‐doped LLZO samples were prepared by adding different excess amounts of Li 2 O, and the effect of excess amount of Li 2 O on the structure and performance of LLZO have been researched. The results show that with the rise of the amount of Li 2 O, the lithium ionic concentration increases gradually, and the lithium ionic conductivity and the ratio of grain resistance to total resistance rise first and then drop. When the excess amount of Li 2 O is 10 wt.%, the sample exhibits the highest lithium ionic conductivity of 1.36 mS/cm, and the lithium symmetric battery exhibits the most stable operation.