Taibai Li, Xiang Ge, and their colleagues from School of Materials and Metallurgy, Guizhou University have reported the efficient closed-loop recycling of the cathode material lithium cobalt oxide (LCO) of lithium-ion batteries employing ChCl:OA type deep eutectic solvent. The ultrafast leaching process can be achieved in 10 s at 180 ℃, and a nearly 100% leaching rate can be achieved in 2 h at 90 ℃, which meets the requirements of mild and efficient reaction process design.

Furthermore, DIW is added or evaporated into the leaching solution to achieve direct precipitation of cobalt ions and reversible recovery of the leaching solvent. The cobalt ions may be precipitated as cobalt oxalate phase, annealed, and calcined into LCO material with good crystallinity, and its electrochemical performance is comparable with the commercialized sample. The work was published as a manuscript entitled “Closed-loop cobalt recycling from spent lithium-ion batteries based on a deep eutectic solvent (DES) with easy solvent recovery” in the Journal of Energy Chemistry.