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.