Reuse of Ni-Co-Mn oxides from spent Li-ion batteries to prepare bifunctional air electrodes

Spent lithium ion batteries are potential environmental hazards and if not re-cycled waste natural resources. One of the difficulties for recovery is the recycling cost high and restricting the economic drivers. In this research, a process is developed to directly reuse nickel-manganese-cobalt oxides from spent lithium ion batteries to prepare air electrodes based on a simple thermal treatment method. 100% value metals (cobalt, nickel and manganese) were regenerated from the cathode. By heated at 600 degrees C, the Ni-Co-Mn oxides experienced a significant phase change from an alpha-NaFeO2-type structure to spinel structure. Electrochemical tests revealed that the regenerated nickel-manganese-cobalt oxides exhibited remarkable bifunctional catalytic activities towards the oxygen evolution and oxygen reduction reactions in aqueous KOH electrolyte. The nickel-manganese-cobalt oxide powders were applied in an air battery, the energy efficiency was 75% at a current density of 10 mA cm(-2), which was better than commercal zinc-air batteries.