Li metal batteries (LMBs) have been widely studied due to the unprecedented theoretical specific capacity and ultralow redox potential of Li metal anode (LMA). Nevertheless, out-of-control growth of lithium dendrite and fragile solid-electrolyte interphase (SEI) seriously limit their practical applications. Herein, 2D sp²-carbon-linked covalent organic framework (sp²c-COF) is prepared and constructed as artificial SEI film on the surface of LMA for impeding the formation of Li dendrite and regulating the interface stability. The sp²c-COF is designed to be fully π-conjugated along both the x and y orientations with high conductivity, which can reduce interface impedance and facilitate the uniform distribution of Li⁺ flux. Consequently, the sp²c-COF-modified symmetric batteries exhibit high Li⁺ transference number (t_Li+) of 0.85, excellent cycle life (4000 h) and extremely low over-potential (10 mV) at a current density of 5 mA cm⁻² with 5 mA h cm⁻². Meanwhile, the Li deposition behavior is analyzed by in-situ light microscopy, indicating sp²c-COF significantly enhances interfacial stability of LMA. This strategy possesses potential value for restraining Li dendrite formation and promoting the progress of COF artificial SEI film.

由于锂金属负极（LMA）前所未有的理论比容量和超低氧化还原电位，锂金属电池（LMB）得到了广泛研究。然而，锂枝晶的失控生长和脆弱的固体电解质界面（SEI）严重限制了它们的实际应用。在此，制备了二维 sp ² -碳连接的共价有机骨架 (sp ² c-COF) 并将其构建为 LMA 表面的人工 SEI 膜，以阻止锂枝晶的形成并调节界面稳定性。sp ² c-COF 设计为沿x和y方向完全 π 共轭^{具有高电导率的取向，可以降低界面阻抗并促进Li +}通量的均匀分布。因此，sp ² c-COF 修饰的对称电池在 5 mA 的电流密度下表现出 0.85 的高 Li ⁺转移数 ( t _Li + )、出色的循环寿命 (4000 h) 和极低的过电位 (10 mV) cm ^-2 5 mA h cm ^-2。同时，通过原位光学显微镜分析Li沉积行为，表明sp ²c-COF 显着增强了 LMA 的界面稳定性。该策略对于抑制锂枝晶的形成和促进COF人工SEI膜的发展具有潜在价值。