Atomic Layer Deposition of LixAlyS Solid-State Electrolytes for Stabilizing Lithium-Metal Anodes

Increasing global demands for energy storage in electric vehicles and the grid necessitate beyond-lithium-ion batteries that simultaneously exhibit high capacity, long-term cyclability, and excellent safety. Several candidates, most notably lithium-air and lithium-sulfur batteries, utilize lithium-metal anodes. Although the specific capacity of lithium metal is unrivaled (3860 mAhg(-1)), the capacity fade and risk of catastrophic failure must be overcome. Herein, we describe ultrathin, ionically conducting lithium aluminum sulfide (LixAlyS) coatings prepared on lithium-metal anodes by using atomic layer deposition, which stabilize the Li-electrolyte interface and reduce (up to five times) the interfacial impedance of lithium-metal anodes in contact with organic electrolyte. We demonstrate that these thin films effectively suppress dendrite formation and preserve a smooth, low-surface-area morphology for electrodeposited lithium metal, thereby doubling the lifetime of Li-Cu asymmetric cells.