Recovery of organic electrolyte solvents from spent perforated Li-ion cells using a low-temperature vacuum-assisted distillation process

• -Electrolyte solvent recovery is often overlooked in Li-ion battery recycling, with solvents usually lost through evaporation or decomposition during pre-treatment stages such as shredding. • -Controlled removal is essential due to the flammable, toxic, and hazardous nature of electrolyte components. • -Organic electrolyte solvents recovered from perforated, not shredded, spent Li-ion cells via mild-temperature vacuum distillation. • -Process conditions: 110°C, 80 mBar vacuum, 300 minutes treatment time. • -FT-IR, TGA, XRD, and IC used for analysis of recovered products and scrubbed solutions. • -Achieved ∼84% recovery of DMC, EMC, and EC. • -No HF or POF₃ detected in exhaust gas; scrubber solution remained neutral during operation. • -Thermal treatment below 110°C offers a simple, feasible, and environmentally beneficial method for electrolyte recovery before metal recovery. Electrolyte solvent recovery is rarely addressed in current state-of-the-art lithium-ion battery (LiB) recycling processes, even though electrolytes are flammable, toxic, and hazardous. In conventional recycling processes, electrolytes typically evaporate or decompose uncontrollably during pre-treatment steps such as shredding, leading to both safety risks and environmental damage. To overcome these limitations, we investigated a controlled electrolyte solvent recovery process using mild-temperature vacuum distillation on perforated, intact batteries rather than shredded material. This method enabled safe handling and minimised uncontrolled emissions during pre-treatment. Analysis results demonstrate a successful 84 % recovery of the major electrolyte solvents, dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and ethylene carbonate (EC), after 300 minutes of thermal-vacuum treatment at 110 °C and 80 mBar vacuum pressure. Decomposition products of Lithium Hexafluorophosphate (LiPF₆), which include hydrogen fluoride (HF) and phosphoryl fluoride (POF₃), were not identified in the exhaust gas, and the scrubber solution remained neutral during operation. These results demonstrate that thermal treatment below 110°C is a simple, feasible, and environmentally beneficial method for recovering electrolyte solvents prior to metal recovery, addressing a major gap in current LiB recycling processes.