Department of Civil Engineering, Faculty of Engineering, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
ERS International, Toronto, Ontario, M1P 2R7, Canada.
J Environ Manage. 2024 Aug;366:121862. doi: 10.1016/j.jenvman.2024.121862. Epub 2024 Jul 16.
Efficient recycling of critical metals from spent lithium-ion batteries is vital for clean energy and sustainable industry growth. Conventional methods often fail to manage large waste volumes, leading to hazardous gas emissions and dangerous materials. This study investigates innovative methods for recovering critical metals from spent LIBs using synergistic leaching. The first step optimized thermal treatment conditions (570 °C for 2 h in air) to remove binder materials while maintaining cathode material crystallinity, confirmed by X-ray diffraction (XRD) analysis. Next, response surface methodology (RSM), I-optimal, was used to examine the synergistic effects of sulfuric acid (SA) and organic acids (Org, citric and acetic acids) and their concentrations (SA: 0.5-2 M and Org: 0.1-2 M) on metal leaching for an eco-friendlier process. Results showed that adding citric acid to SA was more effective, especially at lower concentrations, than using acetic acid. The medium was tested to evaluate the impact of reductant addition. Remarkably, it was discovered that the optimized leaching mixture (1.25 M SA and 0.55 M citric acid) efficiently extracted metals without the need for any reductant like HO, highlighting its potential for a simpler and more eco-friendly recycling process. Further optimization identified the ideal solid-to-liquid ratio (62.5 g/L) to minimize acid use. Finally, RSM (D-optimal) was used to investigate the effects of time and temperature on leaching, achieving remarkable recovery rates of 99% ± 0.7 for Li, 98% ± 0.0 for Co, 90% ± 6.6 for Ni, and 92% ± 0.4 for Mn under optimized conditions at 189 min and 95 °C. Chemical cost analysis revealed this method is about 25% more cost-effective than conventional methods.
从废旧锂离子电池中高效回收关键金属对于清洁能源和可持续工业的发展至关重要。传统方法往往无法处理大量的废物，导致危险气体排放和危险材料的产生。本研究采用协同浸出法从废旧 LIB 中回收关键金属的创新方法。第一步优化了热处理条件（在空气中 570°C 处理 2 小时），以去除粘结剂材料，同时保持阴极材料的结晶度，这通过 X 射线衍射（XRD）分析得到了证实。接下来，使用响应面法（RSM）、I-最优法研究了硫酸（SA）和有机酸（Org，柠檬酸和乙酸）及其浓度（SA：0.5-2 M 和 Org：0.1-2 M）对金属浸出的协同作用，以实现更环保的工艺。结果表明，在较低浓度下，柠檬酸与 SA 混合比乙酸更有效。测试了该介质以评估还原剂添加的影响。值得注意的是，发现优化的浸出混合物（1.25 M SA 和 0.55 M 柠檬酸）无需添加任何还原剂（如 HO）即可有效地提取金属，这突出了其在更简单、更环保的回收工艺中的潜力。进一步的优化确定了理想的固液比（62.5 g/L）以最小化酸的使用。最后，使用 RSM（D-最优）研究了浸出时间和温度的影响，在 189 分钟和 95°C 的优化条件下，实现了 Li 的 99%±0.7、Co 的 98%±0.0、Ni 的 90%±6.6 和 Mn 的 92%±0.4 的显著回收率。化学成本分析表明，该方法比传统方法的成本效益高约 25%。
