Reduction Mechanism of Metal Cobalt from Cathode Material of Waste Lithium Cobalt Oxide Battery

Abstract

The electrical properties of Co(III) in LiCoO2 on Pt working electrode in 1023 K NaCl–CaCl2(1:1) molten salt are studied by cyclic voltammetry and square wave voltammetry. The reduction of Co(III) in LiCoO2 to cobalt is a two-step reduction process, Co(III) → Co(II) → Co. The cobalt of the flakes is directly prepared in 1023 K molten NaCl–CaCl2. The sheet LiCoO2 is used as a cathode, and the graphite is used as an anode. The potential of the preparation of elemental cobalt by LiCoO2 is determined by electrochemical tests. The reduced flakes are analyzed by XRD, EDS, and SEM to confirm that the reduced material is pure metallic cobalt. The production of metallic cobalt by molten chloride salt electrolysis is a green and environmentally friendly metal preparation process.