Synergistic enhancement of borophosphate glasses - halides in Li+ ionic conductivity of LLTO

Li 0.5 La 0.5 TiO 3 (LLTO) is a promising solid-state electrolyte material due to its excellent chemical stability, wide electrochemical window, and relatively high ionic conductivity. This work aims to further improve the ionic conductivity of LLTO via modification with borophosphate glasses containing lithium halides. The underlying rationale is that the unique mixed network structure of borophosphate glass can provide additional pathways for lithium ion (Li + ) transport. Furthermore, the incorporation of halogenated borosilicate glass (especially LiI) is expected not only to supply extra Li + , but also to improve the solid electrolyte interface by filling the voids among LLTO pellets, thus enhancing the overall electrochemical performance. The results demonstrate that the sample with 2 wt.% Li 2 O-B 2 O 3 -P 2 O 5 -LiI (LBPI) glass achieves a favorable room temperature ionic conductivity of 1.03 × 10 –3 S·cm –1 , which is approximately double that of the pristine LLTO. Our findings confirm the synergistic modification effect of borophosphate glass and lithium halides in improving Li + transport and present a strategic approach for developing advanced solid-state electrolytes with satisfactory electrochemical performance.