Formation of Stable Mixed LiF and Li‐Al‐Alloy Reinforced Interface Film for Lithium Metal Anodes

Abstract Metallic lithium is the most promising candidate for implementation in high energy density batteries. Nevertheless, the practical application of Li anode is hindered by its uncontrollable dendrite formation and strong electrolyte reactivity. Here, the replacement and alloying reactions are employed to form in‐situ LiF and Li−Al‐alloy mixed layers that synergistically reinforces the interfacial film on a metallic lithium anode. Due to the film's high ionic conductivity and apparent chemical stability, the artificial interfacial film can inhibit the growth of lithium dendrites and improve the cycling stability of batteries.