Non-steady State Electrodeposition Processes and Electrochemical Methods

Abstract

In the absence of faradaic processes the concentration of reacting species in the electrochemical cell is uniform, and no diffusion layer is formed at the electrode . After imposing an applied potential or a current to the electrode of interest, the concentration profile of the various electroactive species changes with time until it is stabilized by the balance of faradaic, diffusional and convective processes. A stationary diffusion layer with a definite thickness is eventually set up when the applied potential or current is constant in time; this situation was discussed in the previous chapter. Under non-steady state electrochemical conditions, which include in particular those cases where the current or potential vary with time, also the diffusion layer evolves with time. In this chapter, various time-dependent electrochemical phenomena will be considered, focusing particularly on their influence on metal electrodeposition. The concepts thus developed will also be applied to the study of electrode kinetics.