Lattice‐Electron Synergistic Pinning Strategy for Intensified Regeneration of Spent Ternary Cathodes

Abstract

ABSTRACT The hydrometallurgical recycling of spent lithium‐ion batteries (LIBs) confronts a fundamental scientific challenge in enhancing the structure while restoring the cathode chemistry, particularly in remedying the intrinsic Ni/Li antisite disorder and lattice distortions that dictate cycling stability. Herein, we propose a synergistic lattice‐electron pinning strategy induced by localized microenvironmental reconfiguration to achieve dual‐intensification of the regenerated structure and performance of retired LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523). The constructed localized strongly correlated Na–O–Ni ionic‐covalent‐bonding network enhances the strength of Ni–O bond, anchoring the lattice oxygen and ultimately effectively suppressing planar gliding in (003) facets. Simultaneously, the enlarged electronegativity difference between Na and O elevates the local electrostatic potential of Ni site, and the consequently increased Δ t drives the spin pinning of Ni 3+ from high‐spin ( t 2g 5 e g 2 ) to low‐spin ( t 2g 6 e g 1 ), significantly suppressing the superexchange interaction along Ni–O–TM bonds. The optimized regenerated cathode delivers a remarkable capacity retention of 69.6% after 400 cycles at 0.5 C, surpassing commercial NCM523 (42.3%) and unoptimized regenerated cathode (40.3%) by 164% and 172%, respectively, and ranks among the top‐performing regenerated NCM cathodes to date. This work highlights the significance of pinning effect in hydrometallurgical and establishes a sustainable‐route for converting spent LIBs into high‐quality regenerated cathodes.