Recovery of Nickel and Cobalt from Spent NiMH Batteries by Electrowinning

For nickel and cobalt recovery from spent NiMH batteries by electrowinning, the effect of different electrowinning parameters as boric acid concentration, temperature, current density, and pH were studied using different synthetic solutions. The optimized operational parameters were applied in an electrowinning test with a solution achieved by leaching the electrodes of NiMH batteries. The electrowinning tests were performed galvanostatically in a two-compartment cell separated by an anionic membrane. A platinum/iridium-coated titanium anode and a stainless-steel cathode were used. A sodium sulfate solution served as anolyte. The results demonstrate the technical viability of nickel and cobalt recovery. The chemical composition of the obtained deposit presented high nickel and cobalt concentrations.