Impedance measurements of zinc and amalgamated zinc electrodes in alkaline electrolyte

Abstract

The behaviour of zinc and amalgamated zinc electrodes in alkaline zincate electrolytes was studied with the impedance technique in the frequency range 0.01–65,000 Hz. The impedance spectra of the amalgamated zinc electrode can be adequately described with a kinetic and diffusion controlled reaction. The results are not affected by the method of amalgamation. The zinc electrode shows a different impedance spectrum indicating that surface processes in which intermediate species such as Zn(OH), Zn(OH) − 2, Zn(OH) − 3 are involved, play a more important role. The i o-values that can be derived from the impedance data were found to be in good agreement with the values obtained with the galvanostatic pulse technique.