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.