Recycling metals from lithium ion battery by mechanical separation and vacuum metallurgy

Abstract

The large-batch application of lithium ion batteries leads to the mass production of spent batteries. So the enhancement of disposal ability of spent lithium ion batteries is becoming very urgent. This study proposes an integrated process to handle bulk spent lithium manganese (LiMn₂O₄) batteries to in situ recycle high value-added products without any additives. By mechanical separation, the mixed electrode materials mainly including binder, graphite and LiMn₂O₄ are firstly obtained from spent batteries. Then, the reaction characteristics for the oxygen-free roasting of mixed electrode materials are analyzed. And the results show that mixed electrode materials can be in situ converted into manganese oxide (MnO) and lithium carbonate (Li₂CO₃) at 1073K for 45min. In this process, the binder is evaporated and decomposed into gaseous products which can be collected to avoid disposal cost. Finally, 91.30% of Li resource as Li₂CO₃ is leached from roasted powders by water and then high value-added Li₂CO₃ crystals are further gained by evaporating the filter liquid. The filter residues are burned in air to remove the graphite and the final residues as manganous-manganic oxide (Mn₃O₄) is obtained.

Keywords: In situ recovery; Lithium ion battery; Mechanical separation; Vacuum metallurgy.