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

Abstract

In this study, we investigate the effect of the Li3BO3 additive on the densification and ionic conductivity of garnet-type Li7-La3Zr2O12 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 Li7La3Zr2O12-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 1100oC for 8 h, the Li7La3Zr2O12-8 wt.% Li3BO3 composite shows a total ionic conductivity of 1.61 × 10−5 Scm−1, while that of the pure Li7La3Zr2O12 is only 5.98 × 10−6 Scm−1.