Regeneration of spent graphite anode via molten salt assisted gas-phase restructuring for enhanced lithium storage

Achieving efficient closed-loop regeneration of spent graphite is crucial for energy sustainability, but it is hindered by bulk structural distortion and the loss of effective active sites, which lead to the degradation of bulk/interface transport properties. To address this challenge, this study proposes a molten salt-assisted vapor-phase reconstruction strategy, aiming to synergistically repair the bulk structure and reconstruct the interfacial active network. This strategy achieves coordinated optimization from atomic-scale lattice repair to bulk/interface transport, significantly reducing the interfacial charge transfer resistance for Li⁺ within the graphite lattice and its bulk diffusion resistance. The results demonstrate that the reconstructed G-N-K anode significantly enhances the lithium-ion diffusion coefficient and reduces the formation of irreversible dead lithium. It exhibits a high Coulombic efficiency (90.5%), outstanding rate capability (maintaining 215.7 mAh/g at 4C), and long-term cycling stability (a specific capacity of 360.7 mAh/g at 1C over 500 cycles with 100% capacity retention). In summary, this work not only accomplishes the high-value regeneration of spent graphite but also untangles the synergistic mechanism between bulk structural repair and enhanced interfacial transport, providing valuable theoretical insights for designing sustainable energy storage materials with high kinetic performance.