Free-standing graphene films decorated with lithiophilic particles as host electrodes 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 this work, we fabricate a series of free-standing porous graphene films decorated with lithiophilic particles of AlN@Li₃N, MgF₂, Li₂CO₃, and the Mg–Li alloy foil, and systematically explore 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 during lithium plating/stripping, to elaborate on the effects of different components in the film on the lithium plating/stripping. We demonstrate that the graphene sheets serve as an optimal host for lithium plating/stripping, the AlN@Li₃N, MgF₂, and Li₂CO₃ enable the formation of an inorganic LiF- and Li₃N-rich solid electrolyte interphase, and the Mg–Li alloy foil compensates for lithium loss during long-term cycling. The anode-less lithium metal batteries with the as-obtained graphene film as the host electrode, NCM811 as the cathode, and a carbonate-based electrolyte exhibit excellent electrochemical performance, with capacity retention reaching ∼60% after 120 cycles at 1.93 mA cm⁻².