Li-Ni-Co-Mn oxides powders recycled from spent lithium-ion batteries for OER electrodes in CO2 reduction

This research reports the effects of factors such as metal ratio, thermal treatment temperature, time and atmosphere in a previously developed path that recycled spent lithium-ion batteries for OER catalysts. With regards to the uncontrollable metal-ratio in recycled material, for the first time, the metal ratio of the Li-Ni-Co-Mn oxides' influence on their electrochemical performance is studied. In thermal treatment, the atmosphere is newly evaluated as a determining factor, while factors like temperature and time are also further compared. The mechanism of the lattice change resulted from the reductive decomposition reaction of LixCoO2 (x not equal 1) (alpha-NaFeO2-type), generating Co3O4 (spinel) is introduced. Finally, the recycled material is innovatively applied to CO2 electrolysis as anode OER catalyst with high current efficiency (97%) towards CO production under a total current density of 32 mA cm(-2) at 2.25 V, with an energy efficiency of 63%, which shows a promising future in the industry use. (C) 2020 Elsevier B.V. All rights reserved.