g‐C3N4 Derivative Artificial Organic/Inorganic Composite Solid Electrolyte Interphase Layer for Stable Lithium Metal Anode

Abstract Lithium metal anodes are one of the most promising anodes in “next‐generation” rechargeable batteries. However, continuous dendrite growth and interface instability of the anode have prevented practical applications. Constructing an artificial solid electrolyte interphase (SEI) is an effective way to solve these issues. Herein, an artificial organic/inorganic SEI layer (denoted as N‐organic/Li 3 N) is designed, consisting of Li 2 CN 2 and Li 3 N phases, to achieve stable cycling of Li metal electrodes. Density functional theory (DFT) results reveal that the N‐organic/Li 3 N layer with a high Li ionic conductivity can effectively facilitate the transport of Li ions across the electrode surface and lead to uniform Li ionic flux on Li electrodes via strong interactions between Li ions and N‐organic groups, resulting in dendrite‐free Li stripping/plating. The N‐organic/Li 3 N‐coated Li (denoted as N‐organic/Li 3 N@Li) anode delivers stable long‐term cycling performance over 1100 h with a fixed areal capacity of 2 mAh cm −2 under 1 mA cm −2 . A full battery assembled with a LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) cathode displays better long‐term cycle performance when the N‐organic/Li 3 N@Li composite anode is applied. The advantages of the organic/inorganic artificial SEI provide important insights into the design principles of SEI for lithium metal anodes.