Efficient Dissolution of Lithium-Ion Batteries Cathode LiCoO₂ by Polyethylene Glycol-Based Deep Eutectic Solvents at Mild Temperature

With the increasing demand of lithium-ion batteries in recent decades, the growing waste from the electrode materials of lithium-ion batteries has become an urgent problem. Lithium cobalt oxide (LiCoO 2 ), used as the cathode materials of lithium-ion batteries, exhibits high capacity and excellent stability but also a high price. To recycle the LiCoO 2 cathode, it is desirable to develop solvents for the dissolution of LiCoO 2 . At present, the dissolution of LiCoO 2 still requires strong acid or a high temperature. Here, benign polyethylene glycol-based deep eutectic solvents (DES) were designed and further used for the dissolution of LiCoO 2 under mild conditions with high solubility. This work provides a new route for the green recovery of lithium-ion cathodes with high efficiency and low energy consumption.