Recycling of LiCoO2 cathode material from spent lithium ion batteries by ultrasonic enhanced leaching and one-step regeneration.

A novel process for recycling of spent LiCoO 2 cathode materials has been developed. The novel process comprises an ultrasonic enhanced leaching and one-step regeneration of LiCoO 2 materials with spray drying method. The ultrasonic is novelly applied for effectively improving leaching process of spent LiCoO 2 materials in the system of DL-malic acid and H 2 O 2. The leaching efficiencies of 98.13% for Li and 98.86% for Co were presented under the optimal condition of 1.5 mol/L DL-malic acid with 3 vol% H 2 O 2 , the solid/liquid ratio of 4 g/L, ultrasonic power of 95 W, temperature of 80 °C and leaching time of 25 min. Based on kinetic analysis, the ultrasonic enhanced leaching process is mainly controlled by the diffusion control model. Meanwhile, the product of Co(C 4 O 5 O 5) 2 formed on particles surface of spent LiCoO 2 materials during ultrasonic enhanced leaching process, which is provided from reaction mechanism analysis of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Finally, the regenerated LiCoO 2 materials are regenerated in one step by spray drying from leaching solution, which present good electrochemical performance. A green sustainable process of recycling spent LiCoO 2 by ultrasonic enhanced leaching and one-step regeneration is developed. Image 1 • The sustainable closure process for recycling of spent LiCoO 2 materials is developed. • Waste acid would not be output during the whole green process. • Ultrasonic is applied to improving the leaching of spent LiCoO 2 materials. • One-step regeneration of leachate is proposed for preparing new cathode materials. [ABSTRACT FROM AUTHOR]