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.