Metal Recovery of LiCoO2/LiNiO2 Cathode Materials by Hydrothermal Leaching and Precipitation Separation
Metal Recovery of LiCoO2/LiNiO2 Cathode Materials by Hydrothermal Leaching and Precipitation Separation
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DOI：
10.1021/acssuschemeng.2c04259
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发表时间：
2022-09
期刊：
影响因子：
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通讯作者：
Akitoshi Nakajima;Qingxin Zheng;Tetsufumi Ogawa;Seiya Hirama;Masaru Watanabe
中科院分区：
文献类型：
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作者：
Akitoshi Nakajima;Qingxin Zheng;Tetsufumi Ogawa;Seiya Hirama;Masaru Watanabe
在此，使用一系列沉淀剂，二甲基乙二肟（DMG）、（NH4）2C2O4和Na3PO4，分别沉淀和分离商业LiCoO2/LiNiO2正极材料通过柠檬酸水热浸出获得的浸出液中的Ni、Co和Li离子。在金属分离步骤中对 pH 值、沉淀剂用量和反应温度等参数进行了优化。最终，Ni、Co和Li的回收率分别为97.2、96.1和94.1%，相应沉淀物中Ni、Co和Li的纯度分别为96.3、96.2和99.9%。比较了水热浸出方法与传统浸出方法的浸出机理以及所得浸出液的金属分离性能。与传统的还原剂（如H2O2）浸出相比，水热浸出温度较高，需要耐压反应器，但可以减少还原剂等化学品的消耗，促进反应速率，提高工业适用性。尽管浸出机理不同，但水热浸出和传统浸出获得的浸出液在金属分离步骤中表现出相当的性能，表明水热浸出有资格生产用于锂离子电池（LIB）回收的浸出液。随着从水热浸出获得的浸出液中成功分离出金属成分，由水热浸出和沉淀分离步骤组成的升级湿法冶金方法正式启动用于锂离子电池回收，并有待进一步开发。
Here, Ni, Co, and Li ions in the leachate obtained from commercial LiCoO2/LiNiO2cathode materials by hydrothermal leaching with citric acid were precipitated and separated in order using a series of precipitants, dimethylglyoxime (DMG), (NH4)2C2O4, and Na3PO4, respectively. The parameters including the pH value, precipitant amount, and reaction temperature were optimized during the metal separation step. Finally, the recovery rates of Ni, Co, and Li were 97.2, 96.1, and 94.1%, respectively, with the purities of Ni, Co, and Li in the corresponding precipitate being 96.3, 96.2, and 99.9%, respectively. The method of hydrothermal leaching was compared with the method of traditional leaching in terms of the leaching mechanism and the metal separation performance of the obtained leachates. Compared with the traditional leaching with a reductant (e.g., H2O2), hydrothermal leaching is performed at higher temperatures and requires pressure-resistant reactors, but it can reduce the consumption of chemicals such as reductants, promote the reaction rate, and improve industrial applicability. Even though the leaching mechanisms were different, the leachates obtained by hydrothermal and traditional leaching showed comparable performance in the metal separation step, indicating hydrothermal leaching is qualified to produce leachates for lithium-ion battery (LIB) recycling. With the success of isolating metal components from the leachate obtained by hydrothermal leaching, an upgraded hydrometallurgical method, composed of hydrothermal leaching and precipitation separation steps, was officially launched for LIB recycling and is subject to further development.