Low cycling reversibility and safety concerns are hindering the practical application of high-energy lithium metal batteries. Rational design of an artificial electrode/electrolyte interface is regarded as an effective way to circumvent the above problems. Herein, a phosphating–nitriding method is developed through the reaction between lithium metal and a PCl5–LiNO3 complex. An as-formed hybrid interface, consisting of Li3N, Li3PO4, and nanocrystalline LiCl, offers high ionic conductivity and strong mechanical stability for uniform lithium electrodeposition. The dendrite-free behavior is further investigated through ex situ and in situ techniques. Accordingly, the modified 50 μm Li anode exhibits a high-current-density durability of 10 mA cm–2 and a long-term cycling performance of greater than 300 h at a high Li-metal utilization of 30.6% under a conventional EC/DEC electrolyte. A full cell paired with a high-voltage cathode LiNi0.5Co0.2Mn0.3O2 (NCM523) displays a 4-fold improvement in cell lifetime under a low negative to positive electrode capacity ratio (N/P ratio) of 3.92. This work paves a new way to construct an advanced artificial interface for next-generation high-capacity/high-voltage Li-metal-based batteries.