Synergistic Fe2O3-catalyzed roasting-leaching strategy for green and efficient recovery of metals from spent lithium batteries

Abstract

The rapid expansion of lithium-ion batteries (LIBs) consumption has intensified global concerns regarding resource depletion and environmental risks associated with their disposal. To promote the sustainable development of the new energy industry, this study presents a green, acid-free, and economically viable process for recovering valuable metals from spent LIBs BM through synergistic sulfation roasting coupled with water leaching. Under optimized experimental conditions (gas flow rate of 400 mL•min⁻¹, roasting atmosphere of 5 % SO 2 -20 %O 2 , temperature of 650 °C, Fe 2 O 3 -to-black-mass mass ratio of 1.6, and roasting duration of 90 min), the recycling efficiencies of Li, Co, Cu, and Ni reached 89.65 %, 89.18 %, 91.05 %, and 62.35 %, respectively. Moreover, Thermodynamic analysis and experimental observations revealed that Fe 2 O 3 functions as an effective solid-phase catalyst by maintaining porous reaction interfaces and facilitating multiple sulfation pathways, which significantly enhanced the conversion of metal oxides into water-soluble sulfates. Building on these findings, a novel recycling route was developed by integrating industrial SO₂ emissions, Fe 2 O 3 -containing metallurgical residues, and spent LIBs, achieving simultaneous pollutant mitigation and resource recovery. Finally, comprehensive techno-economic and environmental assessments verified that the proposed process is low-energy, acid-free, and environmentally benign, providing a scalable and circular pathway for LIBs recycling. This work offers a new strategy for coupling metallurgical innovation with waste-to-resource utilization in the context of green and sustainable manufacturing.