Interlayer Lithium Plating in Au Nanoparticles Pillared Reduced Graphene Oxide for Lithium Metal Anodes

Lithium metal anodes suffer from serious safety issues and rapid capacity fade because of nonideal plating/stripping behaviors. Lithium nucleation on undesired positions usually results from nonuniform multiphysical field distributions and the dynamically changing interface thermodynamics. In this study, a sandwich composite anode consisting of gold nanoparticles pillared reduced graphene oxide (rGO) is designed . Because gold nanoparticles preferentially induce lithium nucleation, the typically uncontrolled lithium deposition process becomes a highly nucleation‐guided process. Because the sandwich structure of the Au‐pillared rGO provides a stable anode morphology with cycling and stabilizes the solid electrolyte interface layer, the Au‐pillared rGO delivers a high Coulombic efficiency of up to 98% for at least 200 cycles for 1600 h. Using this pillared structure, an interlayer plating process is revealed in rGO‐sandwiched anodes, which differ from either conventional metallic anodes or intercalation anodes. The Au‐pillared design bridges the gap between metal and intercalation anodes, and provides a novel strategy to improve the efficiencies and cyclability of lithium anodes. An interlayer plating mechanism for metallic lithium anodes is revealed in a sandwich structure with gold nanoparticles pillared reduced graphene oxide. The layered composite anode is able to guide lithium plating and realize uniform through‐plane expansion and contraction, which stabilizes the solid electrolyte interphase and enhances the cyclability of metallic lithium anodes.