Ultrathin Coating of Metal Nitride as a Robust and Efficient Artificial Solid Electrolyte Interphase Using Atomic Layer Deposition

Abstract

The lithium metal anode (LiMA) is considered promising that can achieve high specific energy > 500 Wh kg-1 for future electric vehicles. Despite attractive features, Li-metal-based anode integration still faces barriers such as lithium dendrite growth, unstable solid electrolyte interphase (SEI) formation, and continuous side reactions, limiting its use in the practical application. Here, metal nitride-based artificial SEI is designed to enhance the stability of LiMA under the synergic effect guidance provided by the SEI. During the ALD coating of MNx (where M=metal), the metal nitride reacts with Li to form Li-metal alloy and lithium nitride (Li3N). The Li-metal alloy and Li3N provide high Li-ion conductivity, lithiophilicity, and a physical barrier between the liquid electrolyte and LiMA, stabilizing the interface and suppressing the Li dendrite growth. As a result, metal nitride deposited Li, compared to bare Li, demonstrates significantly improved electrochemical cell performance with longer cycling stability and lower overpotential. This work will provide an insight on stabilizing SEI for dendrite-free Li deposition to develop long-term cycling stability and safer lithium metal batteries.