锰离子氧化沉淀法实现锂离子电池LiNi0.8Co0.05Mn0.15O2材料的回收和利用

以浓盐酸为浸出剂，以NaOH和NH₄HCO₃为沉淀剂，利用Mn²⁺在碱性条件下的氧化反应改变离子的沉淀次序进而分步回收的方案，探究了浓盐酸酸浸处理三元正极材料LiNi_0.8Co_0.05Mn_0.15O₂的最佳条件。在分步沉淀过程中，Mn²⁺被氧化为不溶于非还原性酸的MnO （OH）₂，并在酸性条件下回收。Ni、Co则在碱性条件下利用NaOH回收，而Li则利用NH₄HCO₃回收。该方法中Mn的回收率达到85.1%，产品纯度达到98.6%； Li的回收率达到95.0%，产品纯度达到99.3%。由回收材料重新合成的三元正极组装的软包电池的首圈放电比容量达到了175 mAh·g^-1，可以以超过99.5%的库仑效率稳定循环50圈。

Manganese ion oxidation precipitation method for the recycling and reusing of LiNi0.8Co0.05Mn0.15O2 materials for lithium-ion batteries

This paper proposes a scheme of recycling spent batteries, using concentrated hydrochloric acid as leaching agent, NaOH and NH₄HCO₃ as precipitating agents. The oxidation reaction of Mn²⁺ under alkaline conditions was included to change the precipitation order of ions, thus recovered ions in steps. The optimal conditions for acid leaching of concentrated hydrochloric acid to treat the ternary cathode material LiNi_0.8Co_0.05Mn_0.15O₂ were studied. In the stepwise precipitation process, Mn²⁺ was oxidized to MnO(OH)₂, which is insoluble in non-reducing acids, and then Mn was recovered under acidic conditions. While Ni and Co were recovered under alkaline conditions by using NaOH. Li was recovered by using NH₄HCO₃. Using this method, the recovery of Mn reached 85.1% and the product purity reached 98.6%; the recovery of Li reached 95.0% and the product purity reached 99.3%. The pouch cell assembled with the re-synthesized ternary cathode using the recovered material reached a discharge specific capacity of 175 mAh·g^-1 in the first cycle. It could stably cycle for 50 cycles with Coulombic efficiency of over 99.5%.