Leaching lithium from the anode electrode materials of spent lithium-ion batteries by hydrochloric acid (HCl)

Spent lithium-ion batteries (LIBs) are considered as an important secondary resource for its high contents of valuable components, such as lithium and cobalt. Currently, studies mainly focus on the recycling of cathode electrodes. There are few studies concentrating on the recovery of anode electrodes. In this work, based on the analysis result of high amount of lithium contained in the anode electrode, the acid leaching process was applied to recycle lithium from anode electrodes of spent LIBs. Hydrochloric acid was introduced as leaching reagent, and hydrogen peroxide as reducing agent. Within the range of experiment performed, hydrogen peroxide was found to have little effect on lithium leaching process. The highest leaching recovery of 99.4 wt% Li was obtained at leaching temperature of 80 °C, 3 M hydrochloric acid and S/L ratio of 1:50 g/ml for 90 min. The graphite configuration with a better crystal structure obtained after the leaching process can also be recycled.