Sustainable Recycling and Regeneration of Cathode Scraps from Industrial Production of Lithium-Ion Batteries

The burst demand of lithium-ion batteries (LIBs) for energy storage leads to an increasing production of LIBs. The huge amount of electrode scraps produced during the industrial production cannot be overlooked. A sustainable and simple method was developed to regenerate Li(Ni_1/3Co_1/3Mn_1/3)O₂ electrode scraps as new cathodes for LIBs. Three different separation processes, including direct calcination, solvent dissolution, and basic solution dissolution, were applied to obtain the active materials. Then, a heat treatment was used to regenerate the scraps. The effects of separation methods and heat treatment temperatures were systematically investigated. The results show that the scraps regenerated with solvent dissolution and heat treatment at 800 °C deliver the highest reversible discharge capacities of 150.2 mA h g^-1 at 0.2C after 100 cycles with capacity retention of 95.1%, which is comparable with commercial Li(Ni_1/3Co_1/3Mn_1/3)O₂ cathodes. When cycled at 1C, a highly reversible discharge capacity of 128.1 mA h g^-1 can be obtained after 200 cycles. By contrast, scraps regenerated through a direct calcination method at 600 °C exhibit the best cycling performances, with the highest capacity retention of 96.7% after 100 cycles at 0.2C and 90.5% after 200 cycles at 1C. By characterizations of XRD, SEM, XPS, and particle size distribution analysis, the improved electrochemical performances of regenerated cathodes can be attributed to the uniform particle morphology and newly formed protective LiF composite. The simple and green regeneration process provides a novel perspective of recycling scraps from industrial production of LIBs.