锂离子电池正极材料回收与再生的相关机理研究

With the increasing markets of lithium-ion batteries(LIBs), serious resource shortages and environmental problems are arising rapidly for spent LIBs, such as low leaching efficiency and secondary environmental pollution. Based on these technic problems, hydrometallurgical recycling technology using natural organic acid was introduced to study optimal conditions for higher leaching efficiency of valuable metal ions for cathode materials of spent LIBs.Through geometry optimization, spectral analysis, energy calculations and solvation analysis for structural models of the various chelate systems, the effect of the metal ion chelates microstructure on the macroscopic properties of leaching system was studied from the level of atoms, molecules, molecular clusters, as well as the extraction mechanism and kinetic properties. Using the above leaching solution as raw materials, cathode materials are prepared by co-precipitation method and will exhibit much higher reversible capacity（≥200mAh/g）, good cycling performance (capacity retention≥90% over 50 cycles and perfect rate performance. This technology will not only provide a strong support to improve the production-recycling industry of lithium-ion batteries, but also will offer a key common technology for its assoicated industrial applications.

随着锂离子电池市场份额逐步提升，所引发的资源短缺和环境问题日趋严重，目前废旧锂离子电池存在处理效率低,并对环境造成二次污染等亟待解决的难题。本项目采用天然有机酸湿法绿色回收技术，研究废旧锂离子电池正极材料中金属离子高效溶出的优化条件及关键技术，通过对各类螯合物体系的结构模型几何优化、频谱分析、能量计算及溶剂化作用等研究，从原子、分子、分子团簇等层次分析金属离子螯合物的微观结构对浸出体系宏观性质的影响，诠释天然有机酸的作用机制、浸提机理和动力学性质；以浸出溶液为原料，采用共沉淀法，重新合成可作为新电极材料使用的高性能正极材料，使材料可逆脱嵌锂容量高（≥200mAh/g），循环稳定性好（50周后容量保持率≥90%），同时具有良好倍率性能。该技术的研究将为实现锂离子电池的生产－回收的循环产业提供有力支撑，并为其工业化应用提供关键共性技术。

本项目采用琥珀酸、草酸等天然有机酸湿法绿色回收技术，研究废旧锂离子电池正极材料中金属离子高效溶出的优化条件及关键技术，并对各类螯合物体系的结构模型几何优化、频谱分析、能量计算及溶剂化作用等研究，阐述了天然有机酸的作用机制、浸提机理和动力学性质；以浸出溶液为原料，采用辅助溶胶凝胶法重新合成高性能正极材料，材料可逆脱嵌锂容量大于200mAh/g，循环50周后容量保持率≥90%。