Porosification and Fe3+ Intercalation of Spent LiCoO2 as an Efficient Oxygen Evolution Electrocatalyst

Lots of spent Li-ion batteries have caused waste of mineral resources and environmental pollution. However, it is extremely challenging to develop more efficient recycling methods. Therefore, in this paper, the reconstitution of spent lithium cobalt oxides (LiCoO2) was achieved by delithiation and iron intercalation in an aqueous two-electrode system, which was used for the oxygen evolution reaction. The electrochemical deintercalation of Li+ promoted the formation of 3D porous LiCoO2, which exposed more active sites in contact with the electrolyte. The intercalation of Fe3+ increased the conductivity of LiCoO2 and introduced Fe3+ active sites, which were more favorable for the oxygen evolution reaction. As a result, the reconstituted Fe 0.5 h-SLCO with an intercalation time of 0.5 h exhibited an overpotential of 325 mV at a current density of 10 mA cm−2 and a Tafel slope of 57 mV decade–1 in 1 M KOH, which was even more excellent than part of synthesized LiCoO2-based catalysts reported in other literature.