Electrochemical and structural characterization of cobalt recycled from cathodes of spent Li-ion batteries

In this work, cobalt from spent Li-ion batteries of cellular phones was recycled using electrochemical techniques. The efficiency, structure and morphology of deposits were influenced by the pH solution and charge density. Maximum efficiency is obtained for pH = 5.40 for all charge densities analyzed. The presence of the cobalt hcp phase for both pH solutions (5.40 and 2.70) and charge density conditions (10.0 and 50.0 C cm⁻²) used in the electrodeposition process was detected by X-ray diffraction. The growth of the cobalt deposit is favored in the crystallographic direction 002] for pH = 5.40 and in the direction 110] for pH = 2.70 when the charge density is 10.0 C cm⁻². The 100] and 101] crystallographic directions of hcp phase were detected by X-ray diffractogram for both pH conditions when the charge density was increased to 50.0 C cm⁻². The potentiodynamic dissolution of the cobalt depends on its structural composition.