Self-Induced Dual-Layered Solid Electrolyte Interphase with High Toughness and High Ionic Conductivity for Ultra-Stable Lithium Metal Batteries

Lithium (Li) metal is considered as one of the most promising candidates of anode material for high-specific-energy batteries, while irreversible chemical reactions always occur on the Li surface to continuously consume active Li, electrolyte. Solid electrolyte interphase (SEI) layer has been regarded as the key component in protecting Li metal anode. Herein, a controllable dual-layered SEI for Li metal anode in a scalable, low-loss manner is constructed. The SEI is self-induced by the predeposited LiAlO₂ (LAO) layer during the initial cycles, in which the outer organic layer is produced due to the electrons tunneling through LAO, resulting in the reduction of electrolyte. The robust inner LAO layer can promote uniform Li deposition owing to its favorable mechanical strength and ionic conductivity, and the outer organic layer can further improve the stability of SEI. Benefiting from the remarkable effects of this dual-layered SEI, enhanced electrochemical performance of the LAO–Li anode is achieved. Additionally, a large-size LAO–Li sample can be easily obtained, and the preparation of the modified Li metal anode shows huge potential for large-scale production. This work highlights the tremendous potential of this self-induced dual-layered SEI for the commercialization of Li metal anode.