Efficient Direct Recycling of Spent Batteries: Integrated Lithiation and Delamination

Direct recycling offers a promising alternative for regenerating spent Li-ion batteries (LIBs); however, achieving high-purity cathode and ensuring cost-effectiveness remains challenging. Herein, we present an innovative integrated process that simultaneously enables delamination and relithiation of spent cathodes, Li_xNi_0.6Co_0.2Mn_0.2O₂ and Li_xFePO₄, under open-air conditions with minimal energy. By oxidizing diethylene glycol, a green solvent, the transition-metal oxidation state in the cathode is effectively reduced, thereby facilitating Li reinsertion into the structure. Consequently, the formation of glycol aldehyde induces 100% electrode delamination, enabling a one-pot restoration pathway. The reaction mechanism is elucidated using Proton nuclear magnetic resonance (¹H-NMR), Soft X-ray absorption spectroscopy (soft-XAS), and X-ray absorption near-edge structure spectroscopy (XANES), and the regenerated cathodes consistently recover over 99% of their electrochemical performance for both 2 and 50 Ah cells. Furthermore, the regeneration solution is reusable, requiring only Li salt supplementation. This study presents a practical, low-cost, and environmentally friendly approach for advancing the scalability and feasibility of direct LIB recycling technologies.