Metal deposition and stripping under self-supported conditions: Experiment and simulation

To what extent does the mass-transport to and from an electrochemical interface change when the dimensions of the electrode are comparable to the Debye length of the system? This work develops a theoretical model for the deposition and stripping of a metal from an electrode accounting for finite electrolyte concentrations. When the electrode is large compared to the Debye length electroneutrality holds and migration significantly influences the mass-transport of ions in the vicinity of the electrode, altering the electrochemical current. However, simulations predict that when the electrode is comparable to or smaller than the Debye length of the system then the influence of migration is minimised. In the experiment, the steady-state reductive flux for the deposition of silver to a microelectrode is shown to deviate from that expected on the basis of electroneutrality and is compared with simulation while the results also show an altered rate of metal nucleation in the absence of additional supporting electrolyte.