电解加工

The rapidly increasing production of lithium-ion batteries (LIBs) and their limited service time increases the number of spent LIBs, eventually causing serious environmental issues and resource wastage. From the perspectives of clean production and the development of the LIB industry, the effective recovery and recycling of spent LIBs require urgent solutions. This study provides an overview of the current hydrometallurgical processes employed in the recycling of spent cathode materials, focusing on the leaching of valuable metals and their postprocessing. In particular, this research reviews the various leaching systems (inorganic acid, organic acid, and ammonia) and the separation of valuable metals, and then, recommendations for subsequent study are offered in an attempt to contribute to the development of highly efficient methods for recycling spent cathode materials. In addition, a range of existing technologies, such as solvent extraction, chemical precipitation, electrochemical deposition, and regeneration, for the postprocessing of leaching solutions are summarized. Finally, the promising technologies, existing challenges and suggestions with respect to the development of effective and environmentally friendly recycling methods for handling spent cathode materials are identified. Graphical abstract 近年来, 锂离子电池产量增长迅速及其有限的服役寿命导致了废弃锂离子电池量的急剧增加, 从而造成了严重的环境问题和资源浪费。从清洁生产和产业可持续发展的角度来看, 废弃锂离子电池的高效回收和再利用是亟待解决的问题。本文概述了目前用于回收废弃锂离子电池正极材料的湿法冶金工艺, 特别是有价金属的浸出及其后处理。同时回顾了各种浸出系统(无机酸、有机酸和氨基体系)和有价金属的分离提纯过程, 为后续研究提供参考, 为开发废弃正极材料的高效回收方法提供参考。此外, 总结了包括溶剂萃取、化学沉淀、电化学沉积和再生等在内的现有浸出液后处理技术的特点。最后，指出了发展高效和环境友好型的废弃正极材料回收方法存在的挑战和建议。

研究了铝电解中的阳极反应、阳极过电压、电解质对炭电极的湿润性、双电层电容、交流阻抗、阳极效应等阳极过程，得出了可以相互证明的结论。①在阳极区可发生5个电化学电化学反应，阳极产物分别是CO，CO2，COF2，CF4和F2；②在电流密度为0．02－1．2A／cm^2范围内符合Tafel方程，反应控制步骤为化学反应CxO．O分解反应的迟滞，反应级数为0．5级；③测量了冰晶石－氧化铝溶体在石墨电极上的性和双电层电容，发现在1．0V左右，湿润角有一最大值，双电层电[容有一最小值，因此认为此电位为零电荷电位；④提出了发生阳有效应的新机理，认为当电质中Al2O3质量分数＜2％时，是F^-离子放电引起的阳极效应，而当Al2O3质量分数＞2％时，阳极效应的发生是因为阳极气体的阻塞。