Garnet-type Li_6.75La₃Zr_1.75Ta_0.25O₁₂ (LLZTO) is a promising solid electrolyte due to its high ionic conductivity and good stability to Li. However, poor wettability of LLZTO|Li interface causes huge contact impedance and easily inclined formation of Li dendrites. Herein, a 700 nm-thick MgF₂ sol film is constructed on the LLZTO pellet by a spin coating method, then an all-inorganic mixed conductive layer of Li-Mg alloy/LiF (LMF) is firstly obtained by the conversion reaction with molten Li, without adding any binder or filmogen with high resistance and low migration rate. Density functional theory (DFT) calculation results show that LMF layer has perfect interfacial contact with LLZTO and Li metal, as well as excellent electronic insulativity and ionic conductivity to prevent electron tunneling and attacking the LLZTO. The interface impedance of Li|LMF@LLZTO|Li symmetrical battery is significantly reduced from 1850 to 25 Ω cm², and an excellent cycle stability over 1000 h is obtained at 0.3 mA cm⁻² with a low overpotential of 62 mV. Moreover, the Li|LMF@LLZTO|LiFePO₄ full battery shows outstanding rate capacity and cycle performance, revealing the practical feasibility of the interface modification strategy for all-solid-state Li metal battery.

石榴石型 Li _6.75 La ₃ Zr _1.75 Ta _0.25 O ₁₂ (LLZTO) 因其高离子电导率和对锂的良好稳定性而成为一种很有前途的固体电解质。然而，LLZTO|Li界面润湿性差，导致接触阻抗大，容易倾斜形成锂枝晶。在此，700 nm 厚的 MgF ₂采用旋涂法在LLZTO颗粒上构建溶胶薄膜，首先通过与熔融Li的转化反应得到Li-Mg合金/LiF（LMF）全无机混合导电层，无需添加任何粘合剂或成膜剂。高抗性和低迁移率。密度泛函理论（DFT）计算结果表明，LMF层与LLZTO和锂金属具有完美的界面接触，以及优异的电子绝缘性和离子电导率，可以防止电子隧穿和攻击LLZTO。Li|LMF@LLZTO|Li对称电池的界面阻抗从1850 Ω cm 2 显着降低到25 Ω cm ^{2 ，在0.3 mA cm -2}下获得了1000 h以上的优异循环稳定性，具有62 mV的低过电位。此外，Li|LMF@LLZTO|LiFePO₄全电池表现出优异的倍率容量和循环性能，揭示了全固态锂金属电池界面修饰策略的实际可行性。