Radical-driven graphene exfoliation: Upcycling spent graphite anode to high-quality graphene via suspension...

The scalable production of high-quality graphene is hindered by the inevitable trade-off between exfoliation efficiency and structural integrity. By revealing the radical driven wedge cleavage (RDWC) mechanism at the graphene interface, this study achieves the non-destructive exfoliation of graphene. During the RDWC process, the ^•OH acts as a wedge tip, leveraging its high reactivity to selectively oxidize the exposed highly energetic active sites at the graphite edges. This process induces local structural relaxation, thereby initially opening the interlayer channels. Subsequently, the SO₄^•- serves as the wedge body. Driven by its potent electrophilicity, it intercalates into the graphite layers along the previously expanded channels. By extracting π- electrons and generating dipole repulsion between the layers, it weakens the van der Waals forces maintaining the layered structure, ultimately achieving interlayer exfoliation. Thus, the defects of graphene are confined to the edges, and its sp²-hybridized structure remains. The RDWC process, initiated via graphite-suspension electrolysis, can could directly upcycle spent graphite from lithium-ion batteries to almost the best reported, waste originated high-quality graphene (I_D/I_G ≈ 0.04, 98% ≤ 10 layers, ∼2.43 μm). Life cycle assessment shows that this approach could significantly reduce greenhouse gases emissions, especially waste acids since the electrolyte is recyclable. RDWC is also proved by commercial graphite and mechanically triggered ^•OH and SO₄^•-. Therefore, this research advances the understanding of graphene exfoliation driven by radicals and broadens the exfoliation pathways toward high quality graphene with scalable potential and confined edge defects.