One‐Pot Direct Recycling of Spent LiCoO ₂ via Synergistic Binder Defluorination and Phase Reconstruction

ABSTRACT

Direct recycling of spent lithium‐ion battery cathodes is hindered by two interdependent challenges: persistent polyvinylidene fluoride (PVDF) binder residues that block particle surfaces and incomplete structural repair of degraded layered phases. Here, we report a one‐pot regeneration strategy based on a Li ⁺ ‐containing deep eutectic solvent (Li ⁺ ‐DES) that integrates targeted defluorination and phase reconstruction within a reusable medium. Under mild conditions, the functionalized Li ⁺ ‐DES selectively cleaves C─F bonds of PVDF, enabling complete binder removal and interface purification. Without any solvent exchange, the same Li ⁺ ‐DES serves as a lithium‐rich repair medium, in which enhanced Li ⁺ coordination and transport promote the formation of a uniform pre‐lithiation layer and facilitate the conversion of inactive spinel Co ₃ O ₄ back into well‐ordered layered LiCoO ₂ upon annealing. The regenerated LiCoO ₂ delivers a discharge capacity of 157.4 mAh g ⁻¹ at 0.1 C, retains 83.1% of its capacity after 300 cycles, and maintains stable cycling even at 4.6 V. By integrating defluorination, Li replenishment, and structural reconstruction into a single reusable system, this work provides a simplified, energy‐efficient, and sustainable route for closed‐loop recycling of degraded cathode materials.