Selective Recycling of Spent Lithium-Ion Batteries Enables Toward Aqueous Zn-Ion Batteries Cathode

Effective selective recycling of spent lithium-ion batteries (S-LIBs) and giving recycled products a “second life” are crucial for advancing energy supply circularity, environmental and economic sustainability development. However, separating metal compounds with similar charge differences requires substantial energy, water, and chemical inputs. Herein, an innovative strategy is present for selective recycling S-LIBs by photoexcitation inspired by the Hard Soft Acid Base (HSAB) principle. Theoretical calculations and experimental results show that photoexcitation drives charge transfer and modulates subtle charge density differences among metal components, thereby enhancing their solubility disparity and facilitating metal separation. Remarkably, the photoexcitation-induced metal separation factor reaches 46900 and the metal recovery efficiency approaches 100%, representing a significant improvement over non-photoexcitation separation with a separation factor of non-photoexcitation of merely 2.7. Through techno-economic analysis, the viability of photoexcitation selective recycling technology has been confirmed as an eco-friendly and economical approach for battery recycling. Furthermore, high-value reuse of recovered Mn components is implemented. The Recycled Mn components are treated by calcination to obtain porous, defect-rich Mn₂O₃, which showed a specific capacity of 613 mAh g⁻¹ at 0.1 A g⁻¹) in aqueous Zn-ion batteries (AZIBs). This work provides fresh insight into recycling S-LIBs and moving toward more sustainable storage technologies.