Screening 100 Low-Melting Mixture Solvents for Scale-Up and Tunable Recovery of Solid Electrolytes from All-Solid-State Lithium-Ion Batteries by Tailoring Acidity

One hundred low-melting mixture solvents (LoMMSs) are utilized to systematically investigate the impact of acid–base regulation on the leaching efficiency of all-solid-state electrolytes. Results show that the acidity of LoMMSs is positively correlated with the Li leaching efficiency in the all-solid-state electrolytes aluminum-doped lithium lanthanum zirconium oxide and lithium lanthanum zirconium tantalum oxide (LLZTO); however, there is a two-piece linear fitting tendency between the acidity of LoMMSs and La leaching efficiency in the LLZTO. Furthermore, the impact of factors such as the temperature, time, and liquid-to-solid ratio on the dissolution of all-solid-state electrolytes by LoMMSs is also investigated. The leaching efficiencies of LoMMSs for recovering Li and Zr from the all-solid-state electrolytes are 99.24 and 83.74%, respectively. When LoMMSs and the all-solid-state electrolytes are scaled up 100 times to simulate industrial applications, the leaching efficiency of Li decreases only slightly (from 94.81 to 94.70%).