废旧三元锂电池正极材料葡萄糖还原磷酸浸出绿色回收技术研究

传统湿法冶金技术回收三元锂电池正极材料通常采用强酸为浸出剂,过氧化氢为还原剂。而强酸和过氧化氢均有强腐蚀性、二次气体污染及明显的细胞毒性。因此本论文采用葡萄糖还原磷酸浸出三元锂电池正极材料,研究了葡萄糖还原磷酸浸出过程中酸浓度、葡萄糖浓度、固液比、温度和时间对Li、Ni、Co和Mn浸出率的影响,在最佳条件下Li、Ni、Co和Mn的浸出率在95%以上。利用未反应收缩核模型拟合了酸浸过程的动力学数据,结果显示浸出过程由表面化学反应所控制。使用共沉淀-固相法再生了正极材料,其结晶性良好,元素分布均匀,实现了三元锂电池正极材料的闭环再生。

Green recycling technology for glucose reduction phosphoric acid leaching of waste ternary lithium battery cathode materials

In traditional hydrometallurgical technology, ternary lithium battery cathode materials are recovered using strong acid as a leaching agent and hydrogen peroxide as a reducing agent. However, the use of strong acids and hydrogen peroxide results in strong corrosive properties, secondary gas pollution, and cytotoxicity. Therefore, this thesis use glucose reduction phosphoric acid was employed to leach the ternary lithium battery cathode materials. The study evaluated the effects of acid concentration, glucose concentration, solid-liquid ratio, temperature, and time on the leaching rate of Li, Ni, Co, and Mn during the leaching process of glucose reduction phosphoric acid. Under the most favorable conditions, the leaching rates of Li, Ni, Co, and Mn exceeded 95%. The kinetic data of the acid leaching process were fitted using an unreacted shrinkage nucleation model, and the leaching processes were found to be controlled by surface chemical reactions. The cathode materials were regenerated using the co-precipitation-solid phase method, resulting in good crystallinity and uniform element distribution. As a result, the ternary lithium battery cathode materials were regenerated in a closed-loop process.