Full Component Utilization: Targeted Separation of Mn/Li From Spent LiMn₂O₄ for Reconstructing High-Performance Single-Crystal Cathode Materials

Developing green and sustainable regeneration technologies for spent lithium-ion battery cathode materials is of great significance for establishing a self-sufficient and sustainable production model. In this study, full utilization of all metal components in spent LiMn₂O₄ cathode materials is achieved through a strategy involving the directional separation of manganese and lithium. Based on the Ostwald ripening principle, spent LiMn₂O₄ is regenerated into high-performance single-crystal cathodes. The recycled single-crystal lithium manganate (R-LMO) cathode mitigates lattice strain, suppresses Jahn-Teller effect-driven irreversible phase transitions, and enhances structural integrity. Simultaneously, the introduction of oxygen vacancies (OVs) lowers the Li⁺ diffusion energy barrier, thereby improving lithium storage performance in R-LMO. Compared to commercial LiMn₂O₄ (LMO), the R-LMO cathode exhibits superior electrochemical performance at both ambient and elevated temperatures (55°C). After 1000 cycles at 1C, the capacity retention rate of recycled R-LMO reached 81.2%, surpassing that of LMO (68.6%). Moreover, this method avoids the introduction of external ions that could contaminate the final product and generates no chemical waste during the recycling process, eliminating the need for post-treatment of waste streams or effluents. This work provides new insights into component separation from spent cathodes and lays the foundation for sustainable, cobalt-free cathode production.