Upcycling highly degraded Ni-rich cathodes for high performance lithium-ion batteries via microstructure engineering

The efficient recycling of Ni-rich layered oxide cathodes from spent lithium-ion batteries is crucial for sustainable battery technologies. Although direct regeneration methods have been developed, most of them merely restore materials to or below their original state, failing to satisfy the growing industrial demand for cathodes that deliver both high energy and high power densities. Here, we propose a sustainable upcycling strategy that converts highly degraded LiNi_0.83Co_0.11Mn_0.06O₂ into a high-performance cathode through wet-chemical reconstruction and tailored microstructure engineering. This approach can simultaneously eliminate various defects and endow the regenerated material with specific structures, including larger interlayer spacing and robust lattice frameworks, thus enables prolonged cycle stability under extreme operation conditions. The regenerated cathode can deliver a capacity of 221.8 mAh g⁻¹, and exhibits exceptional cycling stability at 4.5 V under different C-rates. When configured in a pouch-type full cell, it retains 93.25% of its initial capacity after 400 cycles at 1C. This work establishes a scalable pathway to bridge sustainable recycling with the escalating requirements for next-generation lithium-ion batteries.