Eco-friendly closed-loop recycling of nickel, cobalt, manganese, and lithium from spent lithium-ion battery cathodes

Abstract

Recycling technology is essential for managing waste and addressing environmental issues related to scrapping power lithium batteries. A closed-loop recycling technique was proposed in this work for maximizing usage of lithium (Li), manganese (Mn), cobalt (Co), and nickel (Ni) resources in spent ternary lithium battery (SNCMB) cathodes. A green and sustainable leaching process utilizes citric acid (CA) and hydrogen peroxide (HP) to efficiently extract Ni, Co, Mn, and Li from SNCMB cathodes. Maximizing leaching rates for Ni (96.69 %), Co (95.38 %), Mn (97.64 %), and Li (98.72 %) under optimal conditions (80 ℃, 4 mol/L CA, 20 g/L solid to liquid (S/L) ratio, 2 vol% HP, 70 min). The Avrami equation models leaching kinetics, requiring a temperature of 80 ℃ to accelerate the process. Hydrogen-type strong acidic cation exchange resin (HR) effectively adsorbs Ni, Co, Mn, and Li ions from leachates through ion exchange under optimal conditions, reducing costs and eliminating the need for separating metals with similar chemical properties. This multi-stage adsorption recycling process renders leachates both economical and eco-friendly. The metal-enriched HR composite (HRC) from the ion-exchange process prepares ternary lithium battery (NCMB) cathodes to maximize metal usage. Microwave heating achieves excellent structure and electrochemical performance of regenerated ternary lithium battery (RNCM) cathodes, with 153.81 mAh/g discharge capacity at 0.1C rate and 90.92 % capacity retention after 50 cycles at 900 ℃ for 4 h. This innovative, efficient, and eco-friendly technique allows for closed-loop recycling of Ni, Co, Mn, and Li from SCNMB cathodes, providing new avenues for lithium battery recycling