Mo‐O Dual‐Doped Argyrodite Electrolyte Enables Stable All‐Solid‐State Lithium Batteries

Abstract Sulfide solid electrolytes are one of the most promising solid electrolytes for all‐solid‐state lithium batteries due to their relatively high ionic conductivity and favorable mechanical properties. Nevertheless, their inferior moisture stability and lithium metal compatibility hinder the practical applications. Herein, a Mo‐O dual‐doped argyrodite Li ₆ P _{1‐ x} Mo _x S _{5‐3 x} O _{3 x} Cl _{1+ x} sulfide electrolytes are synthesized to enhance both moisture stability and electrochemical characteristics. By adjusting the concentrations of dopant and annealing temperature, the optimized Li ₆ P _0.95 Mo _0.05 S _4.85 O _0.15 Cl _1.05 sintered at 570 °C exhibits enhanced room‐temperature powder cold‐pressed ionic conductivity of 3.97 mS cm ⁻¹ . Moreover, Li ₆ P _0.95 Mo _0.05 S _4.85 O _0.15 Cl _1.05 solid electrolyte produces only one‐third of H ₂ S gas with 0.58 cm ⁻³ g ⁻¹ compared to pristine Li ₆ PS ₅ Cl electrolyte and exhibits excellent structure stability after exposure to air. Benefitting from the generation of a stable Li ₃ OCl at the anode interface, Li ₆ P _0.95 Mo _0.05 S _4.85 O _0.15 Cl _1.05 solid electrolyte exhibits superior interfacial compatibility and suppression capability of lithium dendrites, realizing a high critical current density of 1.51 mA cm ⁻² and maintains stable lithium plating/stripping behavior for 5600 h at 0.1 mA cm ⁻² and 0.1 mAh cm ⁻² . In addition, the LiCoO ₂ /Li ₆ P _0.95 Mo _0.05 S _4.85 O _0.15 Cl _1.05 /Li battery presents improved cycling stability at 1C with a capacity retention of 90.3% after 1000 cycles.