All-solid-state lithium metal batteries (ASSLMBs) show great potential for high energy density as well as enhanced safety. However, the practical application is still hampered by uncontrollable dendrite growth and limited cycling stability. Herein, a stable Li₃N-LiF-enriched interface is in-situ induced between poly (ethylene oxide) (PEO)-based solid electrolyte and Li anode by introducing lithium nitrate (LiNO₃). Combining surface characterizations and molecular dynamics simulations, firstly, it reveals that the addition of LiNO₃ facilitates the decomposition of lithium bis(trifluoromethylsulfonyl) imide (LiTFSI) to preferentially form LiF. The Li₃N-LiF-enriched interface greatly improves interface contact between solid electrolyte and Li anode, leading to homogenous Li deposition. With LiNO₃ addition, the critical current density of PEO-based electrolyte can be enhanced to high value of > 0.9 mA cm^–2. Meanwhile, all-solid-state LMBs coupled with LiFePO₄ cathode show superior cycling stability and Coulombic efficiency (CE), especially, the initial CE is up to 94.12 % at 0.5 C. Even paired with high-potential NCM cathode, promoted electrochemical performances can be achieved, with 91.4 % capacity retention after 200 cycles at 0.3 C. What's more, this work illustrates the importance of interface modification in ASSLMBs from the perspective of the relationship between impedances and overpotentials.

全固态锂金属电池 (ASSLMB) 在高能量密度和增强安全性方面显示出巨大潜力。然而，无法控制的枝晶生长和有限的循环稳定性仍然阻碍了实际应用。在此，通过引入硝酸锂（LiNO ₃）在聚（环氧乙烷）（PEO）基固体电解质和锂负极之间原位诱导了稳定的富含Li ₃ N-LiF 的界面。结合表面表征和分子动力学模拟，首先，它揭示了 LiNO _{3 的添加}促进了双（三氟甲基磺酰基）亚胺锂（LiTFSI）的分解，以优先形成 LiF。李_三富含 N-LiF 的界面极大地改善了固体电解质和锂负极之间的界面接触，从而实现了均匀的锂沉积。添加LiNO _{3 后}，PEO 基电解质的临界电流密度可以提高到 > 0.9 mA cm ^{–2 的}高值。同时，全固态LMBs与LiFePO ₄正极结合显示出优异的循环稳定性和库仑效率（CE），尤其是在0.5 C时初始CE高达94.12 %。即使与高电位NCM正极配合，也提高了电化学性能可以实现，在 0.3 C 下 200 次循环后容量保持率为 91.4%。此外，这项工作从阻抗和过电位之间的关系的角度说明了 ASSLMB 中界面修饰的重要性。