In Situ-Formed Dual-Conductive Protecting Layer for Dendrite-Free Li Metal Anodes in All-Solid-State Batteries

Lithium metal anode is regarded as one of the most promising electrode materials for high energy-rechargeable batteries. Nevertheless, the utilization of lithium metal anode suffers from the detrimental lithium dendrite growth caused by uneven lithium deposition. Herein, a dual-conductive protecting layer is formed in situ on a lithium metal surface as an artificial solid electrolyte interface, which is composed of electronic-conductive lithiophilic lithium–gallium alloy and lithium-ion-conductive lithium nitride. The protective layer can not only ensure uniform lithium-ion diffusion but also act as a nuclear agent to lower the deposition overpotential. With this artificial solid–electrolyte interface, the dendrite growth of lithium is significantly suppressed. Symmetric half cells and full cells with a modified lithium metal anode exhibit significantly improved electrochemical performance compared with the bare lithium metal anode.