Free-standing graphene films decorated with lithiophilic particles as host electrode for lithium plating/stripping in anode-less lithium metal batteries

Abstract

The host electrode is key to the lithium plating and stripping in anode-less lithium metal batteries. In the work, we fabricate a series of free-standing porous graphene films decorated with the lithiophilic particles of AlN@Li3N, MgF2, Li2CO3, and the Mg-Li alloy foil, and explore systematically their electrochemical properties as lithium-host materials in anode-less lithium metal batteries. We characterize the structures and morphologies of the multifunctional graphene films before, after, and in the course of the lithium plating/stripping, to elaborate the effects of different components in the film on the lithium plating/stripping. We demonstrate that the graphene sheets serve as optimal host for lithium plating/stripping, the AlN@Li3N, MgF2, and Li2CO3 enable the formation of inorganic LiF and Li3N-rich solid electrolyte interphase, and the Mg-Li alloy foil makes up for the lithium loss during the long-term cycling. The anode-less lithium metal batteries with the as-obtained graphene film as host electrode, NCM811 as cathode, and carbonate-based electrolyte exhibit excellent electrochemical performances, which capacity retention can reach to ~ 60 % after 120 cycles at 1.93 mA cm-2.