Fermented Natural Edible Solvents from Vegetables and Fruits: A Sustainable Approach for Recycling Solid Electrolytes in All-Solid-State Lithium-Ion Batteries

The sustainable hydrometallurgy recovery of solid electrolytes in all-solid-state lithium-ion batteries (ASSLIBs) encounters significant challenges, as it requires solvents to be low-cost, highly degradable, efficiently processed, and abundantly available in nature. In this study, we utilize fermented natural edible solvents (NESs) derived from vegetables and fruits to enhance the recycling of solid electrolytes in ASSLIBs in comparison with pristine NESs. The results indicate that fermented NESs derived from grape, orange, hawthorn, kiwi fruit, watermelon, hami melon, pear, and persimmon demonstrate nearly a 20% improvement in lithium leaching efficiency compared to pristine NESs for the three solid electrolytes tested, namely, lithium lanthanum zirconium tantalum oxide (LLZTO), aluminum-doped lithium lanthanum zirconium oxide (ALLZO), and lithium aluminum titanium phosphate (LATP). Notably, among all of the NESs, the highest lithium recovery efficiency of 94.2% is achieved by fermented NESs derived from pears. In contrast, fermented apple-based NESs show lower lithium leaching efficiency from LLZTO, ALLZO, and LATP compared to pristine NESs. This work provides an effective, sustainable, and cost-efficient approach for recycling solid electrolytes from ASSLIBs.