Direct Regeneration of Spent Li-Ion Battery Cathodes via Chemical Relithiation Reaction

Sustainable recycling of spent Li-ion batteries (LIBs) has provoked widespread public concern, considering the limited resources and environmental sustainability. Currently, industrial-scale reclamation of spent LIBs based on pyrometallurgy and hydrometallurgy only recovers valuable metal elements, accompanied by intense energy consumption. Herein, a closed-loop LIB cathode regeneration chain with high atomic utilization and minimal energy consumption is demonstrated. We designed a thermodynamically spontaneous Li+-electron concerted radical redox process, in which polycyclic aryl-lithium compounds served as both the reducing agent and Li+ donor to heal the Li loss in degraded cathodes. This chemical relithiation process takes only 10 min, but can easily extend the lifetime of the valuable cathodes. Most notably, the Li-donating aromatics and residual solvent can be recirculated for multiple utilizations, thus enabling a closed-loop recycling process with minimal emission of chemical waste. Our efficient and green chemical lithiation strategy provides a new perspective for LIB regeneration and can be extended to more advanced battery systems in the future.