Xiao Jiefeng, Niu Bo, Xu Zhenming
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, People's Republic of China.
J Hazard Mater. 2021 Sep 15;418:126319. doi: 10.1016/j.jhazmat.2021.126319. Epub 2021 Jun 5.
The rapid development of new energy technology leads to explosive growth of lithium-ion batteries (LIBs) industry which greatly alleviates the problems of environmental pollution and energy shortage. However, how to realize resource circulation of critical metals including lithium (Li) and cobalt (Co) becomes the new problem of LIBs industry. This paper proposes an improved thermal reduction technology to efficiently recycle Li and Co from spent LIBs, where cheap urea is applied as the only additive to provide ammonia (NH). By thermal reduction, LiCoO was thermally reduced into water-soluble lithium carbonate and water-insoluble cobalt metal Under the optimal conditions, 99.96% Li with nearly 100% selectivity was obtained by water leaching. More importantly, the concept of "oxygen elements removal (OER)" was proposed to explain the metal extraction from spent LIBs, which could help to describe the reaction mechanism as O-cage digestion mechanism. Furthermore, metal extraction from spent LIBs was re-understood as "seeking an applicable reductant", which provided a fresh perspective for understanding Li selective recovery. These concepts and findings can provide some inspiration for metal recovery from spent LIBs.
新能源技术的快速发展促使锂离子电池（LIBs）产业呈爆发式增长，这极大地缓解了环境污染和能源短缺问题。然而，如何实现包括锂（Li）和钴（Co）在内的关键金属的资源循环利用成为了LIBs产业面临的新问题。本文提出了一种改进的热还原技术，以有效地从废旧LIBs中回收Li和Co，其中使用廉价的尿素作为唯一添加剂来提供氨（NH₃）。通过热还原，LiCoO₂被热还原为水溶性碳酸锂和水不溶性钴金属。在最佳条件下，通过水浸出可获得选择性近100%的99.96%的Li。更重要的是，提出了“氧元素去除（OER）”的概念来解释从废旧LIBs中提取金属的过程，这有助于将反应机理描述为O-笼消解机理。此外，将从废旧LIBs中提取金属重新理解为“寻找适用的还原剂”，这为理解Li的选择性回收提供了新的视角。这些概念和发现可为从废旧LIBs中回收金属提供一些启示。
