Artificial LiF‐Rich Interface Enabled by In‐Situ Electrochemical Fluorination for Stable Lithium‐Metal Batteries

Lithium (Li)‐metal batteries are promising next‐generation energy storage systems. One drawback of uncontrollable electrolyte degradation causes them to form a fragile and nonuniform solid electrolyte interface (SEI). In this study, we proposed a fluorinated carbon nanotube (CNT) macrofilm (CMF) on Li metal as a hybrid anode, which can regulate the redox state at anode/electrolyte interface. Due to the favorable reaction energy between plating Li and fluorinated CNTs, the metal can be fluorinated directly to a LiF‐rich SEI during the charging process, leading to a high Young’s modulus (~2.0 GPa) and fast ionic transfer (~2.59×10–7 S cm–1). The obtained SEI can guide the homogeneous plating/stripping of Li during electrochemical processes while suppressing dendrites growth. In particular, the hybrid endowed full cells with substantially enhanced cyclability allows for high‐capacity retention (~99.3%) and remarkable rate capacity. This work can extend fluorination technology into a platform to control artificial SEI formation in Li‐metal batteries giving it stability with long‐life performance.