The dendritic growth of Li metal leads to electrode degradation and safety concerns, impeding its application in building high energy density batteries. Forming a protective layer on the Li surface that is electron‐insulating, ion‐conducting, and maintains an intimate interface is critical. We herein demonstrate that Li plating is stabilized by a biphasic surface layer composed of a lithium‐indium alloy and a lithium halide, formed in situ by the reaction of an electrolyte additive with Li metal. This stabilization is attributed to the fast lithium migration though the alloy bulk and lithium halide surface, which is enabled by the electric field across the layer that is established owing to the electron‐insulating halide phase. A greatly stabilized Li‐electrolyte interface and dendrite‐free plating over 400 hours in Li|Li symmetric cells using an alkyl carbonate electrolyte is demonstrated. High energy efficiency operation of the Li₄Ti₅O₁₂ (LTO)|Li cell over 1000 cycles is achieved.

中文翻译：

---

通过原位形成的双相表面层稳定锂电镀

锂金属的树枝状生长会导致电极退化和安全问题，从而阻碍了其在构建高能量密度电池中的应用。在Li表面形成一层电子绝缘，离子导电并保持紧密界面的保护层至关重要。我们在这里证明锂镀层是由锂铟合金和卤化锂组成的两相表面层所稳定的，该两相表面层是通过电解质添加剂与锂金属的反应原位形成的。这种稳定作用归因于锂快速穿​​过合金块体和卤化锂表面迁移，这是由于电子绝缘的卤化物相在整个层上形成的电场所致。使用碳酸烷基酯电解质的Li | Li对称电池在400个小时内具有高度稳定的Li电解质界面和无枝晶镀层。锂高能效运行实现了1000个循环以上的₄ Ti ₅ O ₁₂（LTO）| Li电池。