Impedance measurements during the cycling of a zinc electrode

Electrodeposition of Zinc and Zinc Alloys

“…From a more practical point of view, it was shown in a flowthrough channel cell that various types of deposits (flat, bulbous, or dendritic) could be obtained as a function of current density and Reynolds number [16]. Further research on the subject concentrated on the deposit morphology [15][16][17][18][19][20][21][22][23], with the aim to improve the control of surfaces with powdery deposits, and also on the quality of dense deposits made, first, by pulsated current or by superimposing alternating current (ac) on direct current (dc) and, second, with organic additives or on the electrode mechanism [24][25][26][27][28][29][30][31][32]. To summarize, because of the high value of the exchange current density (see [30, p. 2657]; values in the literature are between 2 and 31 A dm À2 ), surface diffusion should not be rate determining; diffusion in solution is more likely to play this role [18].…”

Effects of Organic Additives on Initial Stages of Zinc Electroplating on Iron

“…The current decay beyond the peak potential at around Ϫ0.85 V indicates how well hydrogen evolution is suppressed due to zinc electrodeposition at the iron electrode surface. 9,13 When the organic additives were added to the solution, the currents were generally depressed except for BA. The presence of PEGs apparently reduced both hydrogen evolution and zinc electrodeposition, whereas BA controlled only the zinc reduction process in the UPD region.…”

“…[6][7][8][9] The effects of the organic molecules on the bulk electrodeposition process itself and the physical characteristics of the electrodeposited layers have been examined by voltammetric, radiometric, and electrochemical impedance spectroscopic studies. [10][11][12][13][14][15][16] The initial electrodeposition process was reported to affect the mechanical properties of electrodeposits. 1,7 When the work function of a metal being electrodeposited is lower than that of the substrate metal, the electrodeposition may occur at a potential more positive than the equilibrium potential, a phenomenon called underpotential deposition ͑UPD͒.…”

Zinc regeneration in rechargeable zinc-air fuel cells—A review

“…After that they act as physical crosslinks into the electrode material and eventually affect the kinetics of zinc deposition, resulting in mitigating the shape change of the zinc electrode. Regarding the solution additives, tetrabutyl ammonium bromide (TBAB) has also shown promise for limiting dendrite formation in repeated charge/discharge cycles at lower cathodic over-potentials [21,67,71,72]. Its large organic cationic species were suggested to undergo specific adsorption at high-charge-density sites of the electrode where zinc-dendrite growth centers were active.…”

“…Its large organic cationic species were suggested to undergo specific adsorption at high-charge-density sites of the electrode where zinc-dendrite growth centers were active. This blocked the deposition at such sites, while it continued at other, less favorable, sites with lower and more even surface charge densities, thereby producing a smoother distribution of coherent Zn deposits [28,67,71,72]. The solution additives, e.g., fluorinated surfactants such as Atochem…”