Oxide-Based Nanoporous Interlayer for Durable Anodic Interface in All-Solid-State Lithium Metal Batteries

Highly promising Li metal all-solid-state batteries (ASSBs) with enhanced safety and energy density have been plagued by interfacial degradation caused by the high reactivity and dendritic growth of Li at the anodic interface. Herein, a structurally immutable nanoporous oxide material, specifically Li4Ti5O12 (LTO), is proposed as a protective shield to ensure interfacial stability in the Li metal anode. The LTO interlayer at the anodic interface exhibits sufficient electronic and ionic transfer kinetics upon lithiation to 0 V, enabling the Li deposit to penetrate through the LTO interlayer to the Li anode. The separation of Li from the solid electrolyte (SE) suppresses the increase in interfacial resistance caused by voids, dead Li, and SE decomposition, while the structural stability of the LTO ensures long-term cycling. Leveraging the physical and electrochemical robustness of LTO, this protection persists for over 300 cycles in full-cells at a substantial current density of 4.275 mA cm–2 and a capacity of 3 mAh cm–2.