Dual-Layer Multifunctional Protective Layer for Stable Lithium Anodes

Lithium metal is recognized as a promising alternative anode material for next-generation Li batteries. However, the growth of lithium dendrites due to uneven deposition of lithium and the side reactions caused by unstable solid–electrolyte interphase (SEI) films have seriously hindered the development of lithium metal batteries. Therefore, we cast a bifunctional dual-layer protective film of graphene oxide (GO) and SnF 2 onto a Li plate to address the above problems. As a result of the synergistic effect between the SnF 2 -derived LiSn alloy and GO layer, the symmetric cell with modified Li electrodes exhibited extraordinary cyclic stability close to 2900 h when cycled at 0.5 mA cm −2 and 0.5 m Ah cm −2 . Ultralow interfacial impedance of only 3.6 Ω was also obtained at the 50th cycle. This work presents a simple but effective modification strategy to improve the stability of lithium metal battery anodes.