Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China.
Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China.
Waste Manag. 2019 Feb 15;85:175-185. doi: 10.1016/j.wasman.2018.12.034. Epub 2018 Dec 31.
A novel hydrometallurgical process for recycling LiNiCoMnO cathode materials harvested from spent Li-ion batteries (LIBs) is established in this work. The cathode material LiNiCoMnO is dissolved in a mixed acid containing phosphoric acid (leaching agent) and citric acid (leaching agent and reductant). Using 0.2 M phosphoric acid and 0.4 M citric acid with a solid to liquid (S/L) ratio of 20 g/L at 90 °C for 30 min, the proposed method results in a leaching efficiency of ca. 100% for Li, 93.38% for Ni, 91.63% for Co, and 92.00% for Mn, respectively. Kinetics of the leaching process is well described by the Avrami equation. It is found that the leaching process is controlled by surface chemical reactions, and the apparent activation energies (kJ/mol) are 45.83 for Li, 83.01 for Ni, 81.38 for Co and 92.35 for Mn, respectively. With aids of various advanced characterizations methods, including UV-Vis, FT-IR and TOC, we find that there are a great deal of citrates and a small amount of dihydrogen phosphates in the mixed acid leachate. This leaching method enjoys advantages of low acid consumption, short leaching time and no need to add extra reductant.
本工作建立了一种从废旧锂离子电池（LIB）中回收 LiNiCoMnO 正极材料的新型湿法冶金工艺。将正极材料 LiNiCoMnO 溶解在含有磷酸（浸出剂）和柠檬酸（浸出剂和还原剂）的混合酸中。使用 0.2 M 的磷酸和 0.4 M 的柠檬酸，固液比（S/L）为 20 g/L，温度为 90°C，反应 30 min，提出的方法分别使 Li、Ni、Co 和 Mn 的浸出效率约为 100%、93.38%、91.63%和 92.00%。浸出过程的动力学很好地符合 Avrami 方程。研究发现，浸出过程受表面化学反应控制，表观活化能（kJ/mol）分别为 45.83 用于 Li、83.01 用于 Ni、81.38 用于 Co 和 92.35 用于 Mn。通过各种先进的表征方法，包括 UV-Vis、FT-IR 和 TOC，我们发现混合酸浸出液中存在大量柠檬酸和少量磷酸二氢盐。该浸出方法具有酸耗低、浸出时间短、无需添加额外还原剂等优点。
