Pursuing green and efficient process towards recycling of different metals from spent lithium-ion batteries through Ferro-chemistry

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 426; p. 131637
• Main Authors: Jiang, Youzhou, Chen, Xiangping, Yan, Shuxuan, Li, Shuzhen, Zhou, Tao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2021
• Subjects: Different metals; Ferro-chemistry; Recycling; Spent lithium-ion batteries; Spent lithium-ion batteries; Recycling; Ferro-chemistry; Different metals
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.131637

[Display omitted] •Simultaneous recycling multiple cathode materials by their own intrinsic properties.•Usage of oxidant/reductant can be avoided in mild vitriolic medium.•High-purity FePO4 can be directly obtained by selective precipitation.•Synergistic recycling of different metals was achieved by Ferro-chemistry approach. Sustainable recycling of different value-added metals from spent lithium-ion batteries (LIBs) can expect significant environmental and economic benefits for the fulfillment of resources utilization. During the separation and recovery of different metals, excessive chemical consumption caused by prolonged processes may eventually spoil the environmentally soundness recycling of spent LIBs. Here, Ferro-chemistry was innovatively proposed towards the recycling of different metals based on transformation of iron morphology from different types of spent LIBs (LiCoO2 and LiFePO4). It can be concluded from the thermodynamic results that redox reaction will take place in dilute sulfuric acid medium without addition of reductant/oxidant, indicating that Fe(II) in LFP can be used as reductant for the direct leaching of LiCoO2. Leaching results indicate that 99.9% Li, Fe, P and 92.4% Co can be dissolved and existed as Fe3+, Li+, PO43− and Co2+ under the optimized conditions, with a decline of over 80% acid consumption. The leaching kinetics of different metals and reaction mechanism suggest that Fe(II) will be promptly liberated to lixivium and then slowly oxidized into Fe(III) with the existence of Co(III), resulting in a synergetic leaching of Co and Fe. Then, Fe(III) can be precipitated as FePO4 at pH of 2.5, which can remove PO43− with the direct generation of LiFePO4 precursors. This above ferro-chemistry strategy can effectively reduce the consumption of chemicals with reduced environmental footprint.