Hydrometallurgical recovery of critical metals from spent Li-ion batteries using simple leaching-precipitation techniques

ABSTRACT The rising demands for critical metals and the environmental impact of solid waste disposal have increased interest in recycling of spent lithium-ion batteries (LiBs). This study was focused on hydrometallurgical recycling of LCMO type cathode batteries for the recovery of critical metals (lithium, cobalt, and manganese). The process involves sulfuric acid leaching in the presence of a reducing agent (H2O2) followed by the precipitation recovery of critical metals. The influential parameters like pulp density, H2SO4 concentration, H2O2 addition, agitation time, and temperature were optimized, yielding >98% leaching in 2.0 M H2SO4 with 4 vol.% of H2O2 at a moderate temperature of 50°C. Reaction kinetics revealed that the leaching was governed by the mixed-control process. Furthermore, the separation and recovery of metals from leach liquor was conducted by simple precipitation techniques, where KMnO4, C2H2O4, and Na2CO3 were used as precipitating reagents to recover MnO2, CoC2O4, and Li2CO3, respectively.