All-solid-state lithium metal batteries have attracted much attention for their high energy density and safety. Lithium argyrodite is an attractive solid-state electrolyte (SSE) due to its high ionic conductivity and excellent processability at room temperature. However, the poor interfacial contact and side reactions between Li metal and lithium argyrodite seriously hinder its practical applications. In this work, we prepared the lithium argyrodite Li_5.5PS_4.5Cl_1.5 (LPSCl) with room temperature lithium ion conductivity up to 11.2 mS/cm, and improved the interfacial stability between Li metal and LPSCl by introducing a Li₃N interlayer with high ionic conductivity. As a result, the interfacial resistance can be reduced to as low as 1.4 Ω cm² in symmetric cells. The symmetrical cells can be stably cycled for >650 h at a current density of 0.5 mA cm⁻², with a critical current density as high as 1.9 mA cm⁻². Moreover, a Li/Li₃N-LPSCl/NCM811 all-solid-state lithium battery also displays high cycling efficiency and stability over 260 cycles at 50 °C. This work provides a new idea for further optimizing the interface of all-solid-state lithium metal batteries.

全固态锂金属电池因其高能量密度和安全性而备受关注。锂银矿由于其高离子电导率和优异的室温加工性能而成为一种颇具吸引力的固态电解质（SSE）。然而，锂金属与锂银矿之间的不良界面接触和副反应严重阻碍了其实际应用。在这项工作中，我们制备了室温锂离子电导率高达11.2 mS/cm的锂银矿Li _5.5 PS _4.5 Cl _1.5 (LPSCl)，并通过引入高密度_{Li 3} N中间层提高了锂金属和LPSCl之间的界面稳定性。离子电导率。结果，对称电池中的界面电阻可以降低至低至1.4Ωcm ^{2 。对称电池在0.5 mA cm -2}的电流密度下可以稳定循环>650 h ，临界电流密度高达1.9 mA cm ^-2。此外，Li/Li ₃ N-LPSCl/NCM811全固态锂电池在50°C下也表现出高循环效率和超过260次循环的稳定性。该工作为进一步优化全固态锂金属电池界面提供了新思路。