废旧三元锂离子电池正极材料回收技术研究进展

Research Progress on Recycling Technology of Cathode Materials for Spent Ternary Lithium-ion Batteries

三元锂离子电池因其性能优越,在国内外便携式电子设备和新能源汽车中得到广泛应用。随着对锂离子电池需求量的不断增大,大量的锂离子电池将迎来"退役"高峰期。为实现有价金属资源的循环利用,降低固体废物处理对环境的影响,废旧锂离子电池的回收利用受到了广泛的关注。通过对三元锂离子电池进行资源化回收利用,可以获得有价金属或直接制备电池材料。为了提高物料的有效回收率,通常采用预处理的方法来分离集流体和正极活性材料,实现物料的有效分离及进一步的后处理。然后,采用冶金处理的方法从正极活性材料中提取金属和分离杂质,其包括高温冶金和湿法冶金处理工艺。最后,结合材料合成的方法进一步制备得到电池材料或化合物。在现阶段的研究中,高温冶金过程面临着物料损耗大、能耗高、环境不友好等问题;湿法冶金过程存在酸耗大、除杂效率低、工艺流程长等问题。正极材料的再生过程、回收成本以及再合成材料的性能是限制其应用的重要因素。本文主要介绍了废旧三元锂离子电池回收过程及方法,包括预处理、高温冶金、湿法冶金、正极材料再生等,分析比较了其存在的主要问题,为废旧三元锂离子电池的资源化技术发展提供参考。最后,提出了废旧三元锂离子电池正极材料的回收应向绿色环保、短流程和低能耗的方向发展。

Lithium-ion batteries are widely used in new energy vehicles at home and abroad due to superior performance.With the increasing demand forlithium-ion batteries,a large number of lithium-ion batteries will inevitably be retired in the near future.In order to realize the recycling of valuable metal resources and reduce potential environmental impacts of solid waste disposal,a great deal of attention has been paid to the development of an efficient process for recycling spent ternary lithium-ion batteries.Valuable metals or battery materials can be obtained by recycling ternary lithium-ion batteries.In order to improve the recovery rate of materials,a pretreatment method is usually used to separate the current collectors and the cathode materials to achieve effective separation of materials and the further post-processing.Then,metallurgical treatment is used to extract metals and separate impurities from the cathode materials,which includes high temperature metallurgical and hydrometallurgical treatment processes.Finally,battery materials or compounds are further prepared by using the synthesis methods of materials.At the current stage of research,high-temperature metallurgical processes have the problems such as large material loss,high energy consumption,and unfriendly environment;hydrometallurgical processes have the problems such as large acid consumption,low impurity removal efficiency,and long process flows.The regeneration process of cathode materials,the cost of recycling,and the performances of resynthesized materials are the important factors that limit the application.In this paper,we review the recycling technologies of spent ternary lithium-ion batteries,including pretreatment,pyrometallurgy,hydrometallurgy,and cathode material regeneration.We compare the merit and demerit of the above methods,providing references for the development of cathode material recovery technologies in the future and putting forward the prospects and direction of the recycling of spent lithium-ion batteries.