Electrolytic nickel recovery from lithium-ion batteries

Lithium/cobalt/nickel oxide (LiCoxNi1-xO2, 0 < x < 1) is one of the cathode materials currently used in commercial Li-ion batteries. The direct Ni recovery by electrochemical methods from leach liquor obtained by dissolution of this cathode is not possible because of cobalt anomalous co-deposition. After separating Ni from Co by SX methods, nickel has been recovered by means of both galvanostatic and potentiostatic electrowinning. Operative conditions such as solution pH, temperature, Ni concentration, bath agitation and, in the case of galvanostatic operation, current density have been determined for the selected cathode and anode material. The use of galvanostatic conditions enables a good Ni metal deposit to be obtained, while potentiostatic conditions result in an almost complete depletion of nickel in the electrolyte. (C) 2003 Elsevier Science Ltd. All rights reserved.