Fundamental Research on Green and Efficiency Recovery and Regeneration of Lithium Iron Phosphate Cathode Materials

锂离子电池（LIB）由于其特定的能量密度而主导了储能电池市场，以支持车辆电气化和可再生能源的大规模收获。然而，没有有效的回收方法。因此，大量的废锂离子电池将对环境造成潜在的危害，以及高价值资源的重大损失，因此促进了锂离子电池化学和废锂离子电池回收技术的发展。本项目提出了一种从废旧动力电池中回收磷酸铁锂（LiFePO4，或LFP）电极材料的新工艺。为了实现再生LFP的可行性、成本效益、高提取效率和稳健性，将建立直接磷酸浸出的短湿法冶金再循环路线，以再生具有足够锂离子储存能力的活性LFP用于LIB组装。此外，分子设计的新型ditopic萃取剂，使绑定的两个，锂和磷酸根作为离子对，进行了研究。这种方法允许从杂质中分离出高质量的无机锂盐。中德合作项目将在已有科研成果积累的基础上，结合德方萃取技术、先进分子化学和合成化学的优势以及中方湿法冶金的专业知识，进行联合收割机的开发。研究合作将涵盖浸出动力学，新萃取剂的内在分子机理，再生LFP的尺寸控制以及整个回收过程的操作参数优化。提出的水热提取战略及其相关产品设计和产业化将有力地支持可再生能源的可持续发展和LIB的广泛使用。

Lithium-ion batteries (LIBs) have dominated energy storage battery market due to their specific energy density to support the vehicle electrification and large-scale harvesting of renewable power. However, there is no efficient recycling method available. Thus, the large amount of spent LIBs will cause potential hazardous impact to the environment as well as significant loss of high-valuable resources, and therefore promote the development of LIBs chemistry and techniques on recycling spent LIBs. In this project, novel process for the recycling of lithium iron phosphate (LiFePO4, or LFP) electrode materials from spent power battery is proposed. In order to achieve feasibility, cost effectiveness, high extraction efficiency, and robustness of regenerated LFP, short hydrometallurgical recycling-route will be established with directly phosphoric-acid leaching to regenerate active LFP with sufficient capability of Li-ion storage for LIBs assembly. Furthermore, molecular design of novel ditopic extractants, which enable the binding of both, lithium and phosphate as ion pair, are investigated. This approach allows a state-of-the-art separation from impurities to product inorganic Li salts of high quality. Based on the accumulation of scientific research achieved, this Sino-German project will combine the advantage of extraction techniques, advanced molecular and synthetic chemistry from the German side and the expertise of hydrometallurgy from the Chinese side. The research cooperation will cover the kinetics of leaching, the intrinsic molecular mechanism of new extractants, the size manipulation of regenerated LFP, and the optimization of operational parameters for the whole recycling process. The hydrometallurgy-extraction strategy proposed with related product design and industrialization will firmly support the sustainable development of renewable energy and the extensive use of LIBs.