Lithium metal batteries (such as lithium–sulfur, lithium–air, solid state batteries with lithium metal anode) are highly considered as promising candidates for next‐generation energy storage systems. However, the unstable interfaces between lithium anode and electrolyte definitely induce the undesired and uncontrollable growth of lithium dendrites, which results in the short‐circuit and thermal runaway of the rechargeable batteries. Herein, a dual‐layered film is built on a Li metal anode by the immersion of lithium plates into the fluoroethylene carbonate solvent. The ionic conductive film exhibits a compact dual‐layered feature with organic components (ROCO₂Li and ROLi) on the top and abundant inorganic components (Li₂CO₃ and LiF) in the bottom. The dual‐layered interface can protect the Li metal anode from the corrosion of electrolytes and regulate the uniform deposition of Li to achieve a dendrite‐free Li metal anode. This work demonstrates the concept of rational construction of dual‐layered structured interfaces for safe rechargeable batteries through facile surface modification of Li metal anodes. This not only is critically helpful to comprehensively understand the functional mechanism of fluoroethylene carbonate but also affords a facile and efficient method to protect Li metal anodes.

中文翻译：

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双层膜保护锂金属阳极，可实现无枝晶锂沉积

锂金属电池（例如锂硫，锂空气，带有锂金属阳极的固态电池）被认为是下一代储能系统的有希望的候选者。但是，锂阳极和电解质之间的不稳定界面无疑会引起锂枝晶的不希望的和不可控制的增长，从而导致可再充电电池的短路和热失控。在此，通过将锂板浸入碳酸氟代亚乙酯溶剂中，在锂金属阳极上构建双层膜。离子导电膜具有紧凑的双层结构，顶部具有有机成分（ROCO ₂ Li和ROLi），而无机成分丰富（Li ₂ CO ₃和LiF）。双层界面可以保护锂金属阳极免受电解质腐蚀，并调节锂的均匀沉积，从而实现无枝晶的锂金属阳极。这项工作展示了通过对锂金属阳极进行简单的表面改性，合理构造双层结构化界面的概念，从而构建安全的可充电电池。这不仅对全面了解碳酸氟亚乙酯的功能机理至关重要，而且为保护锂金属阳极提供了一种简便而有效的方法。