Repair and regeneration of waste ternary LiNi0.5Co0.2Mn0.3O2 materials to single crystal particles

The rapid expansion of the lithium-ion battery market has intensified the need for recycling and regeneration of used lithium-ion batteries. The present research aimed to directly regenerate secondary agglomerated particles derived from spent lithium nickel cobalt manganese oxide (LiN 0.5 Co 0.2 Mn 0.3 O 2 ) cathode materials into single-crystal particles by employing a ternary molten salt mixture composed of lithium hydroxide, lithium carbonate, and sodium sulfate. The effects of calcination temperature (800 ℃, 850 ℃, and 900 ℃) and calcination duration (10, 12, and 14 h) on the electrochemical performance of the regenerated materials were investigated. Electrochemical evaluation indicated that calcination at 850 °C for 12 h yielded a discharge-specific capacity of 116.7 mAh g⁻¹ during the first cycle at a rate of 1 C (1 C = 160 mAh g⁻¹) and maintained a capacity retention of 84.4% after 400 cycles at 1 C. The regeneration process effectively restored the layered crystal structure of the cathode material, and the regenerated samples exhibited electrochemical properties comparable to those of commercial single-crystal counterparts, confirming the feasibility of using ternary molten salts for direct regeneration of spent lithium nickel cobalt manganese oxide cathodes. Graphical