Dual‐functional ZnO/LiF layer protected lithium metal for stable Li10GeP2S12‐based all‐solid‐state lithium batteries

All‐solid‐state lithium battery has become one of the most promising secondary batteries due to their high energy density and excellent safety. However, the growth of lithium dendrites and side reactions between lithium metal and solid electrolytes hinder the practical application of all‐solid‐state lithium batteries. Herein, a dual‐functional layer of ZnO and LiF is fabricated at the interface between lithium metal and Li10GeP2S12 solid electrolyte by a magnetic sputtering technique. The ZnO/LiF dual‐functional layer can suppress severe Li10GeP2S12/lithium metal interface side reactions and has a high interface energy against lithium which can block the growth of lithium dendrites. The symmetric cell of Li@ZnO/LiF‐Li10GeP2S12‐Li@ZnO/LiF demonstrates stable lithium plating/striping cycling for 2000 h with a small overpotential of 200 mV at 0.1 mA cm−2 and 0.1 mAh cm−2. The full cell of Li@ZnO/LiF‐Li10GeP2S12‐LiCoO2@LiNbO3 shows stable cycling stability for 500 cycles with a high reversible specific capacity of 80 mAh g−1 at 1.0 C. A dual‐functional layer of ZnO and LiF is fabricated at the interface between lithium metal and Li10GeP2S12 solid electrolyte by a magnetic sputtering technique. The synergistic effect of ZnO and LiF can simultaneously suppress the side reactions between the lithium metal and Li10GeP2S12 as well as the growth of lithium dendrites, leading to excellent cycling stability and providing a promising strategy for the application of lithium metal in Li10GeP2S12‐based all‐solid‐state lithium batteries.