Improved interfacial compatibility and ionic conductivity of SnI4 Co-doping Li-argyrodite sulfide electrolyte for all-solid-state lithium batteries

Despite lithium-argyrodite electrolytes have attracted great attention due to the high ionic conductivity and relatively lower cost, their applications are hindered by the inferior air stability and poor Li compatibility. Herein, we report a Sn/I co-doping the Li ₆PS ₅Cl strategy to overcome above obstacles. The optimized LPSC-0.05SnI ₄ exhibits high ionic conductivity of 3.9 × 10 ⁻³ S cm ⁻¹ at room temperature, and improved air stability. More importantly, an in situ formed LiI-rich interface on the lithium anode is introduced through the LPSC-0.05SnI ₄. As a result, the Li/LPSC-0.05SnI ₄/Li symmetric batteries deliver high critical current density of 1.45 mA cm ⁻² and a remarkable steady Li plating/stripping performance over 6000 h at 0.1 mA cm ⁻². The assembled LNO@NMC811/LPSC-0.05SnI ₄ /Li all-solid-state batteries display prominent capacity and cycling stability. This work provides a practical and effective method for designing versatile and high-performance sulfide-based solid electrolytes.