Effect of Li3BO3 Additive on Densification and Ion Conductivity of Garnet-Type Li7La3Zr2O12 Solid Electrolytes of All-Solid-State Lithium-Ion Batteries

In this study, we investigate the effect of the Li₃BO₃ additive on the densification and ionic conductivity of garnet-type Li 7 -La₃Zr₂O 12 solid electrolytes for all-solid-state lithium batteries. We analyze their densification behavior with the addition of Li₃-BO₃ in the range of 2-10 wt.% by dilatometer measurements and isothermal sintering. Dilatometry analysis reveals that the sintering of Li 7 La₃Zr₂O 12 -Li₃BO₃ composites is characterized by two stages, resulting in two peaks, which show a significant dependence on the Li₃BO₃ additive content, in the shrinkage rate curves. Sintered density and total ion conductivity of the system increases with increasing Li₃BO₃ content. After sintering at 1100℃ for 8 h, the Li 7 La₃Zr₂O 12 -8 wt.% Li₃BO₃ composite shows a total ionic conductivity of 1.61 × 10 −5 Scm −1 , while that of the pure Li 7 La₃Zr₂O 12 is only 5.98 × 10 −6 Scm −1 .