Natural SEI-Inspired Dual-Protective Layers via Atomic/Molecular Layer Deposition for Long-Life Metallic Lithium Anode

The solid electrolyte interphase (SEI) layer is one of the key factors for Li metal anode affecting the Li-deposition behavior and electrochemical performances. However, the fabrication of artificial SEI layers with precisely controlled composition, thickness, and mechanical properties is still challenging and difficult to be realized. In this study, we demonstrate an SEI-inspired dual protective layer for Li metal anode with highly controllable structures and robust mechanical properties (the organic alucone as the outer layer and inorganic Al2O3 as the inner layer), which is deposited by atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques. The dual-layer protected Li anode displays significantly enhanced electrochemical performances, suppressed mossy/dead Li formation, and robust properties during the plating/stripping process. It is believed that our design of dual-layer protected Li metal anode by ALD and MLD opens up new opportunities for the realization of next-generation high-energy-density Li metal batteries.