High ion conductive Sb2O5-doped β-Li3PS4 with excellent stability against Li for all-solid-state lithium batteries

The combination of high conductivity and good stability against Li is not easy to achieve for solid electrolytes , hindering the development of high energy solid-state batteries . In this study, doped electrolytes of Li 3 P 1- x Sb x S 4-2.5 x O 2.5 x are successfully prepared via the high energy ball milling and subsequent heat treatment . Plenty of techniques like XRD , Raman, SEM, EDS and TEM are utilized to characterize the crystal structures, particle sizes, and morphologies of the glass-ceramic electrolytes. Among them, the Li 3 P 0.98 Sb 0.02 S 3.95 O 0.05 ( x  = 0.02) exhibits the highest ionic conductivity (∼1.08 mS cm −1 ) at room temperature with an excellent stability against lithium. In addition, all-solid-state lithium batteries are assembled with LiCoO 2 as cathode, Li 10 GeP 2 S 12 /Li 3 P 0.98 Sb 0.02 S 3.95 O 0.05 as the bi-layer electrolyte, and lithium as anode. The constructed solid-state batteries delivers a high initial discharge capacity of 133 mAh g −1 at 0.1C in the range of 3.0–4.3 V vs. Li/Li + at room temperature, and shows a capacity retention of 78.6% after 50 cycles. Most importantly, the all-solid-state lithium batteries with the Li 10 GeP 2 S 12 /Li 3 P 0.98 Sb 0.02 S 3.95 O 0.05 electrolyte can be workable even at −10 °C. This study provides a promising electrolyte with the improved conductivity and stability against Li for the application of all-solid-state lithium batteries.