Impedance spectra have been obtained during the cycling of a zinc electrode both in a Leclanché-cell-type electrolyte and in an alkaline zincate solution. Changes in impedance plots indicate an increase in the electrode area and a variation of the electrode kinetics with cycling. The kinetics of zinc deposition appear to be very sensitive to the contamination of electrolytes by dissolution products. The results confirm a correlation between the presence of an additive such as NBu4 Br and the increase of the cycle life of the zinc electrode.