Low‐Carbon and Eco‐Friendly Direct Regeneration of Retired LiFePO ₄ for Sustainable Lithium‐Ion Batteries

ABSTRACT

Retired LiFePO ₄ batteries have posed a significant threat to environmental protection and resource conservation. Efficient, economical and green regeneration of retired LiFePO ₄ is crucial to minimizing environmental impact and fostering a true recycling of battery materials. Direct regeneration is an effective strategy, with the principal aspect being the selection of Li ⁺ sources and reductants. Here, we report a soft‐chemical method to achieve direct regeneration of retired LiFePO ₄ . One‐step lithiation using lithium carbonate and vitamin C is introduced for efficient Li ⁺ compensation and structural repair in aqueous solution. Systematic studies reveal phase transformation from FePO ₄ to LiFePO ₄ during regeneration and demonstrate excellent property recovery accompanied by high structural reversibility of repaired LiFePO ₄ . Repaired LiFePO ₄ from a retired 37 Ah pouch‐cell (76.1% capacity retention after 2000 cycles) re‐delivers 156.9 mAh g ⁻¹ and keeps 81.1% capacity retention after 1000 cycles. 2.1 Ah repaired‐LiFePO ₄ //graphite pouch‐cell has 89.5% capacity retention after 500 cycles at 2 C. Furthermore, a comprehensive life‐cycle assessment confirms significantly lower energy consumption and environmental footprint through life‐cycle compared with Pyro‐ and Hydro‐recycling methods. This method utilizes readily available, low‐cost and environmental‐friendly reagents, offering substantial advantages over traditional techniques, representing an efficient and economical route for sustainable recycling of retired Li‐ion batteries.