From the analysis of the impedance of nickel deposition, the electrode kinetics is shown to be dependent on the type of anion. In chloride electrolytes a slow electrode activation with cathodic polarization is predominant. In sulfate solutions a low-frequency capacitive feature, favored by a pH decrease, appears to result from interactions between the nickel and hydrogen discharges. An interpretation is proposed where the ad-ion NiadsI acts as both a reaction intermediate and a catalyst associated with a propagating kink site, and where the adsorbed species Hads*, generated by the presence of NiadsI, inhibit the hydrogen evolution. It is concluded that the active area is closely connected to the coverages by adsorbates.