Sb and O dual doping of Chlorine-rich lithium argyrodite to improve air stability and lithium compatibility for all-solid-state batteries

Chlorine-rich lithium argyrodites with ultrahigh ionic conductivity show great potential as solid electrolytes in all-solid-state batteries, while the poor moisture and lithium metal compatibility limit their applications. Here, by tailoring Sb and O dual dopant , Li 5.5 P 0.96 Sb 0.04 S 4.40 O 0.10 Cl 1.5 electrolyte delivers a high Li-ion conductivity up to 7.20 mS cm −1 , excellent air/moisture and lithium metal endurance. The improved air stability is due to the strong Sb–S and P–O bonds in the co-doped electrolyte, inhibiting the reaction with water. While the enhanced lithium metal stability is attributed to the formation of the Li–Sb alloy layer , impeding the growth of lithium dendrites during cycling. The lithium symmetric cell using Li 5.5 P 0.96 Sb 0.04 S 4.40 O 0.10 Cl 1.5 exhibits high critical current density (1.5 mA cm −2 ) and ultralong cyclability (750 h, 0.1 mA cm −2 ). The all-solid-state lithium metal battery using LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode affords a high initial discharge capacity of 144.2 mAh g −1 at 0.1C. Moreover, the assembled battery shows a discharge capacity of 116.2 mAh g −1 at 0.5C and a capacity retention rate of 83.2% after 200 cycles. This work provides the guideline to design sulfide solid electrolytes that enable all-solid-state lithium metal batteries with high energy density and long cyclability.