Sulfide-type argyrodite solid electrolytes (SEs) with halide doping have attracted serious interest. Although other halides such as Cl and Br have been found to enhance Li-ion transport in argyrodites, the direct synthesis of efficiently conductive Li6PS5I without postprocessing has rarely been investigated. In this work, we report the one-step synthesis of highly conductive Li6PS5I with an impressive ionic conductivity of 2.5 × 10-4 S cm-1 at room temperature through a solvent-based method. Moreover, by introducing F- to partially replace I-, hybrid-doped argyrodites Li6PS5FxI1-x (x = 0.25, 0.5, 0.75) have been synthesized. Li6PS5F0.25I0.75 achieves the highest conductivity of 3.5 × 10-4 S cm-1 due to the energetic preference for anion-disordering among F-/I- and S2-, which facilitate faster Li transport as supported by density functional theory (DFT) calculations. With higher F content in argyrodites, Li6PS5F0.75I0.25 displays the best electrochemical stability toward Li metal, as evidenced by long-term stable cycling in Li symmetric cells up to 1100 h. Solid-state Li metal batteries with an active cathode of Li4Ti5O12 (LTO) display an initial specific capacity of 140 mAh g-1 and remain at 105 mAh g-1 after 200 cycles, suggesting great battery cycling performance. This research has developed new compositions in the argyrodite SE family which could lead to advancements in the development of solid-state Li metal batteries. © 2023 American Chemical Society