A copper-catalyzed bioleaching process was developed to recycle cobalt from spent lithium-ion batteries (mainly LiCoO2) in this paper. The influence of copper ions on bioleaching of LiCoO2 by Acidithiobacillus ferrooxidans (A.f) was investigated. It was shown that almost all cobalt (99.9%) went into solution after being bioleached for 6 days in the presence of 0.75 g/L. copper ions, while only 43.1% of cobalt dissolution was obtained after 10 days without copper ions. EDX, XRD and SEM analyses additionally confirmed that the cobalt dissolution from spent lithium-ion batteries could be improved in the presence of copper ions. The catalytic mechanism was investigated to explain the enhancement of cobalt dissolution by copper ions, in which LiCoO2 underwent a cationic interchange reaction with copper ions to form CuCo2O4 on the surface of the sample, which could be easily dissolved by Fe3+. (C) 2011 Elsevier B.V.All rights reserved.