Ultrasonic-assisted leaching of valuable metals from spent lithium-ion batteries using organic additives

• Published in: Separation and purification technology 2021-02, Vol.257, p.117930, Article 117930
• Main Authors: Yan, Shuxuan, Sun, Conghao, Zhou, Tao, Gao, Ruichuan, Xie, Huasheng
• Format: Article
• Language: English
• Subjects: Bagasse pith; Leaching; Organic acids; Spent lithium-ion batteries; Ultrasonic; Valuable metals
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2020.117930

•Application of mixed acids can greatly reduce acid consumption.•Bagasse pith can be used as an efficient reductant.•Ultrasonic-assisted can facilitate the leaching process.•Valuable metals can be effectively dissolved in this process. Sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) has been derived by the growing environmental issues and nonferrous metal resources scarcity. In this study, mixed organic acids (acetic and ascorbic acid) and bagasse pith were innovatively used as leachants and reductant in ultrasonic-assisted leaching of valuable metals from waste cathode materials of spent lithium-ion batteries. Based on the leaching results, over 95% of all valuable metals (Li, Ni, Co and Mn) can be dissolved under optimal leaching conditions. And leaching reactions of different metals fit well with Avrami equation with apparent energy of 40.6 kJ/mol, 42.2 kJ/mol, 42.8 kJ/mol and 43.8 kJ/mol for Li, Ni, Co and Mn, respectively, suggesting that the leaching of these metals was controlled by chemical reaction. Detailed analysis of leaching reaction mechanism indicates that the synergy of mixed acids can significantly reduce acid dosage, and bagasse pith can be hydrolyzed to reducing sugars and other soluble reductants that can be used as reductants to facilitate the leaching process in return. Ultrasonic can also promote the leaching of valuable metals. The current study can be a sustainable alternative for the efficient recycling of valuable metals from spent LIBs, featured with reduced acid consumption, mild leaching conditions and less environmental footprint.