Recovery of Li, Ni, Co and Mn from spent lithium-ion batteries assisted by organic acids: Process optimization and leaching mechanism

• Published in: International journal of minerals, metallurgy and materials Vol. 31; no. 3; pp. 518 - 530
• Main Authors: Ren, Liuyi, Liu, Bo, Bao, Shenxu, Ding, Wei, Zhang, Yimin, Hou, Xiaochuan, Lin, Chao, Chen, Bo
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.03.2024; Springer Nature B.V; School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China%School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China; State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control,Wuhan University of Science and Techno-logy,Wuhan 430081,China%Zhejiang New Era Zhongneng Recycling Technology Co.,Ltd,Shaoxing 312000,China%Shenzhen Water Planning & Design Institute Co.,Ltd,Shenzhen 518000,China
• Subjects: Carbon dioxide; Ceramics; Characterization and Evaluation of Materials; Chemical reduction; Chemistry and Materials Science; Citric acid; Cobalt; Composites; Corrosion and Coatings; Dosage; Environmental effects; Glass; Hazardous materials; Leaching; Lithium; Lithium-ion batteries; Manganese; Materials recovery; Materials Science; Metal ions; Metallic Materials; Metallurgical analysis; Natural Materials; Nickel; Organic acids; Rechargeable batteries; Reducing agents; Research Article; Response surface methodology; Sulfuric acid; Surfaces and Interfaces; Thin Films; Transition metals; Tribology; citric acid; spent lithium-ion batteries; response surface methodology; leaching; sulfuric acid
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-023-2735-1

The proper recycling of spent lithium-ion batteries (LIBs) can promote the recovery and utilization of valuable resources, while also negative environmental effects resulting from the presence of toxic and hazardous substances. In this study, a new environmentally friendly hydro-metallurgical process was proposed for leaching lithium (Li), nickel (Ni), cobalt (Co), and manganese (Mn) from spent LIBs using sulfuric acid with citric acid as a reductant. The effects of the concentration of sulfuric acid, the leaching temperature, the leaching time, the solid–liquid ratio, and the reducing agent dosage on the leaching behavior of the above elements were investigated. Key parameters were optimized using response surface methodology (RSM) to maximize the recovery of metals from spent LIBs. The maximum recovery efficiencies of Li, Ni, Co, and Mn can reach 99.08%, 98.76%, 98.33%, and 97.63%. under the optimized conditions (the sulfuric acid concentration was 1.16 mol/L, the citric acid dosage was 15wt%, the solid–liquid ratio was 40 g/L, and the temperature was 83°C for 120 min), respectively. It was found that in the collaborative leaching process of sulfuric acid and citric acid, the citric acid initially provided strong reducing CO 2 ·− , and the transition metal ions in the high state underwent a reduction reaction to produce transition metal ions in the low state. Additionally, citric acid can also act as a proton donor and chelate with lower-priced transition metal ions, thus speeding up the dissolution process.