Heteroatoms doped holey graphene enhanced carbon frameworks with chemical pre-lithiation affording reversible lithium plating/stripping in anode-free lithium metal batteries

Abstract

The host electrode plays a pivotal role in facilitating the lithium plating and stripping in anode-free lithium metal batteries (AF-LMBs). In the work, we design and fabricate a series of hierarchical carbon frameworks composed of cellulose-derived carbon fibers, holey graphene doped with heteroatoms (B, N, F), and lithium salts, to address the challenges of low coulombic efficiency, poor lithium plating and stripping, and rapid capacity fading of AF-LMBs. The holey graphene provides abundant lithium nucleation sites, leading to uniform plating/stripping, and lower Fermi level of the host electrode, thereby helping to suppress side reactions. The pre-lithiation improves the initial coulombic efficiency to >100 % by offsetting irreversible first-cycle consumption. In parallel, heteroatom doping tends to promote a beneficial, inorganically enriched SEI, thereby reinforcing interfacial stability during lithium plating/stripping. The AF-LMBs assembled with the as-prepared hierarchical carbon frameworks as host electrodes, and NCM811 as cathodes deliver exceptional cycling stability, retaining ∼72 % and ∼67 % of capacity after 100 cycles at 1.93//1.93 mA cm⁻² and 1.93//3.86 mA cm⁻² with carbonate-based electrolyte.