Adaptive Electrochemical Self-Cleaning via Surface Reconstruction Enables Fluoride-Free and Batch-Consistent Cathode Regeneration.

Direct recycling of spent lithium-ion battery (LIB) cathodes holds great promise for sustainable materials recovery. However, residual fluorinated impurities, including inorganic fluoride species and polyvinylidene fluoride (PVDF), remain a persistent challenge due to their chemical persistence and heterogeneous distribution. Here, we report an electrochemically driven self-cleaning strategy that enables fluoride-free adaptive direct recycling of spent cathodes. Using LiNi0.5Co0.2Mn0.3O2 (NMC532) as a model system, anodic polarization activates oxygen-evolution-driven surface reconstruction, generating hydroxylated transition metal (TM) interfaces that trigger the cooperative elimination of fluorinated contaminants. Specifically, the reconstruction promotes proton-assisted dissolution of LiF and related inorganic fluoride species, while simultaneously inducing a hydrophobic-to-hydrophilic interfacial transition that weakens PVDF adhesion and facilitates its removal. These coupled redox-hydrolysis-interfacial processes synergistically eradicate fluorinated residues while preserving the bulk composition and structural integrity of the cathode. The regenerated NMC532 delivers a high discharge capacity of 145.1 mAh·g-1, comparable to commercial material. When implemented in pouch cells, this strategy achieves an inter‑batch capacity variation of less than 1.3%, dramatically outperforming the ∼24.1% variation typical of conventional recycling and meeting commercial consistency standards (± 3%-5%). This reconstruction-enabled self-cleaning strategy is broadly applicable across diverse cathode chemistries, providing a scalable and chemically selective pathway toward impurity‑free, high‑performance battery material regeneration.