Sustainable Tandem Strategy for Recycling the Lithium-Ion Battery Cathode and Treating Waste by Cheap and Biocompatible Deep Eutectic Solvents

Dissolution of the cathode by deep eutectic solvents (DESs) is the key and green step to recycle spent lithium-ion batteries (LIBs); moreover, pollutant removal by adsorbents is the efficient route for environment protection. However, the couple of dissolving the LIB cathode and pollutant removal with high sustainability and low cost has not been reported up to now. Here, we for the first time use cheap and green DESs to dissolve LIBs for the preparation of magnetic adsorbents for wastewater treatment and engine oil removal. Results show that the removal efficiency of wastewater could reach as much as 94.5%. More importantly, the magnetic adsorbents after removing pollutants could be easily regenerated by a magnet. In addition to organic dye removal, the magnetic adsorbent could adsorb 576.75% engine oil. This work would provide a novel sustainable and cheap strategy for achieving spent LIB recycle and pollutant removal subsequently with high efficiency.