Room-Temperature Antisolvent Precipitation and Bio-Based Low-Melting Mixture Solvent Leaching for Sustainable Recycling of Solid Electrolytes.

Abstract

The precipitation of metals from leachates is a crucial step in the hydrometallurgical recycling of solid-state electrolytes (SSEs) from waste all-solid-state lithium-ion batteries (ASSLIBs). Conventional methods, such as high-temperature distillation, low-temperature crystallization, and electro-deposition are often energy-intensive and costly. Therefore, there is a strong demand for lower-energy, cost-effective strategies to precipitate valuable metals from spent batteries. Here, we employ the anti-solvent method-a low-energy approach-to precipitate precious metals from leachates at room temperature for the separation of dissolved SSEs. Among 61 anti-solvents evaluated, diisopropylamine could achieve a Li precipitation efficiency close to 100%. Additionally, bio-based low-melting mixture solvents (LoMMSs) choline chloride (ChCl):polyethylene glycol 200 (PEG) (1:10) is used as green alternatives to deep eutectic solvents and ionic liquids, offering superior performance in dissolving SSEs from ASSLIBs. This work presents an efficient, sustainable, low-energy, and economically viable strategy for the green precipitation of valuable metals from the SSEs of spent ASSLIBs.