Abstract The influence of Ni 2 + on the cathode polarization process and the kinetics equation and its parameters in zinc electrowinning has been investigated in this paper. When [Ni 2 + ] − 1 , the limiting current density increases with increasing Ni 2 + concentration up to a maximum where [Ni 2 + ] = 4 mg L − 1 . This indicates the depolarization of nickel in zinc electrowinning. The limiting current density decreases and the passivation point gradually disappears owing to the polarization function of nickel when [Ni 2 + ] > 4 mg L − 1 . In addition, the presence of Ni 2 + decreases the current efficiency and worsens the surface morphology in the zinc electrowinning process.