2026-10-13T16:10:56Z https://www.scidb.cn/oai

10.57760/sciencedb.0144e 2026-09-29T15:55:03Z

2026-09-29 Breaking the Superexchange Interlock for High-Performance Regeneration of Degraded Single-Crystal Cathodes doi:10.57760/sciencedb.0144e en The accumulation of spent Li-ion batteries necessitates sustainable recycling. However, regenerating high-performance cathodes remains challenging due to severe surface rock-salt phase accumulation and poorly understood regeneration mechanisms. This study elucidates the superexchange interaction–driven failure mechanism of Li1−xNi0.6Co0.1Mn0.3O2 cathodes via magnetic atomic force microscopy and X-ray absorption spectroscopy and unveils the associated regeneration processes through in situ structural, morphological, and surface chemical characterizations. By introducing a medium-temperature preoxidation mechanism, the strongly electron-withdrawing NO3- ligand field extract electrons directly from the localized Ni–O network, effectively oxidizing Ni2+ to Ni3+. This charge depletion substantially downshifts unoccupied antibonding orbitals, decoupling the rigid Ni–O–Ni superexchange network and thermodynamically unlatches the magnetic pinning of the rock-salt phase. Consequently, the decoupled lattice structurally relaxes in situ to form a highly reactive layered NiOOH intermediate. This profound electronic reconfiguration drastically alleviates the electrostatic barrier for rapid Li+ insertion, enabling complete phase reconstruction while eliminating conventional reliance on high Li-salt concentration gradients. Moreover, the specific adsorption of free Cl− in the molten salt regulates isotropic crystal growth, thereby exposing abundant active facets that accelerate Li+ migration. The developed one-pot, dual-temperature-zone, bifunctional molten-salt strategy regenerates spent single-crystal Li1−xNi0.6Co0.1Mn0.3O2 into submicron, pillow-like single crystals. Benefiting from this unique architecture, the regenerated cathode delivers a high reversible capacity (177.7 mAh g−1) and exceptional rate capability (121.1 mAh g−1 at 10C, with 84.1% retention after 100 cycles), outperforming commercial counterparts. This study simultaneously achieves direct regeneration and morphological engineering of spent materials, providing a commercially viable, closed-loop recycling strategy for degraded single-crystal cathodes.  Direct regeneration; Superexchange interaction; Molten-salt chemistry; Facet engineering; Spent lithium-ion batteries 王裕民 王童彤 李翔 RESTRICTED dataset Science Data Bank