With the emergence of the energy crisis and the rise of human environmental awareness, lithium-ion batteries (LIBs), as a new type of energy storage device, are widely used in electric vehicles (EVs), mobile electronic products and stationary energy storage devices. The demand for LIBs has dramatically increased in recent years, leading to a shortage of raw materials for LIBs and a large number of retired LIBs. Therefore, it is particularly important to recycle spent LIBs. Compared with pyrometallurgy and hydrometallurgy, direct recycling, as a more advanced technology, focuses on repairing of the electrodes of spent LIBs. However, direct recycling technology is still in the laboratory operation stage, and there are still many difficulties and challenges to overcome. Herein, we firstly highlight the importance of recycling spent LIBs from LIB market development, raw material supply, environmental impact, and economic benefits. Subsequently, starting from the failure forms and mechanisms of electrode materials, we provide a detailed summary of various direct recycling and upcycling processes, reaction principles, as well as advantages and disadvantages. Additionally, the technology for converting waste cathodes and graphite into new functional materials, a topic rarely addressed in previous reviews, is comprehensively detailed in this review. Lastly, we provide a summary of the current status of LIB recycling and present future challenges. This review may serve as a source of inspiration for researchers and enterprises to develop more advanced recycling methodologies.

中文翻译：

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先进的直接回收技术使废旧锂离子电池的寿命达到第二阶段


随着能源危机的出现和人类环境意识的增强，锂离子电池 （LIB） 作为一种新型的储能装置，被广泛应用于电动汽车 （EV）、移动电子产品和固定储能装置中。近年来，对 LIB 的需求急剧增加，导致 LIB 原材料短缺和大量退役 LIB。因此，回收废旧 LIB 尤为重要。与火法冶金和湿法冶金相比，直接回收作为一种更先进的技术，侧重于修复废锂离子电池的电极。但是，直接回收技术仍处于实验室运行阶段，仍有许多困难和挑战需要克服。在本文中，我们首先强调了从 LIB 市场开发、原材料供应、环境影响和经济效益中回收废 LIB 的重要性。随后，我们从电极材料的失效形式和机理开始，详细总结了各种直接回收和升级回收过程、反应原理以及优缺点。此外，本文全面介绍了将废阴极和石墨转化为新功能材料的技术，这是以前的综述中很少涉及的话题。最后，我们总结了 LIB 回收的现状和当前的未来挑战。这篇综述可以作为研究人员和企业开发更先进回收方法的灵感来源。