Separation of Cu impurities from spent lithium-ion batteries (LIBs) before precipitating other valuable metals is critical to improve the quality of final products. Currently, the main process for separating Cu impurity from spent LIBs by extraction and precipitation has the disadvantage of being high cost and complicated process. In this work, the surface characteristics of spent LIBs materials before and after thermal treatment are explored, and the effects of the concentration of ammonium salts, temperature, and pulp density on the leaching of Cu impurity are investigated. The novel process proposed in this work removes Cu impurities from spent LIBs materials using a solution of (NH₄)₂CO₃ at low concentration. The results suggest that organics on the spent LIBs surface can be effectively removed by heating at a temperature of 505 °C to avoid the influence of organics on the removal of Cu impurities. Furthermore, the results of the leaching experiment demonstrate that (NH₄)₂CO₃ displays an excellent leaching effect on Cu compared to NH₄Cl, (NH₄)₂SO₄, and NH₄HCO₃. The leaching efficiency of Cu at the concentration of 0.25 mol/L (NH₄)₂CO₃, temperature 80 °C and leaching time of 120 min reaches 99.1%. On the contrary, the leaching efficiencies of Ni, Co, and Mn are <4% on average. The thermodynamic analysis proves the potential for removing Cu impurities from spent LIBs materials using a solution of (NH₄)₂CO₃ at low concentration. The process lays the foundation for the subsequent hydrometallurgical process to recover other metals.

在沉淀其他有价值的金属之前，从废锂离子电池 (LIB) 中分离铜杂质对于提高最终产品的质量至关重要。目前，从废锂离子电池中分离Cu杂质的主要工艺是萃取沉淀法，成本高，工艺复杂。在这项工作中，探讨了废 LIBs 材料在热处理前后的表面特性，并研究了铵盐浓度、温度和矿浆密度对 Cu 杂质浸出的影响。本工作中提出的新工艺使用 (NH ₄ ) ₂ CO _{3溶液从废 LIB 材料中去除 Cu 杂质}在低浓度。结果表明，在 505 °C 的温度下加热可以有效去除废 LIBs 表面的有机物，以避免有机物对去除 Cu 杂质的影响。此外，浸出实验的结果表明，与NH ₄ Cl、(NH ₄ ) ₂ SO ₄和NH ₄ HCO _{3相比，(NH 4} ) ₂ CO ₃对Cu表现出优异的浸出效果。Cu在0.25 mol/L(NH ₄ ) ₂ CO _{3浓度下的浸出效率}, 温度 80 °C 和浸出时间 120 min 达到 99.1%。相反，Ni、Co、Mn的浸出效率平均<4%。热力学分析证明了使用低浓度(NH ₄ ) ₂ CO _{3溶液从废 LIB 材料中去除 Cu 杂质的潜力。}该工艺为后续湿法冶金工艺回收其他金属奠定了基础。