Flexural Wave Assisted Electropolishing

Oles Dubrovski, Chemical Engineering, Technion, Haifa, Israel
Ofer Manor, Chemical Engineering, Technion, Haifa, Israel

Increasing the efficiency of electrochemical cells has been stimulating much research. One of the main physical mechanisms found to hinder efficiency is the viscous layer, appearing adjacent to the anode due to the complexation of metallic ions, leaving the anode, and the electrolyte. The viscous layer is one of the main diffusive barriers to the transfer of ions in the cell. In this study, we use theory to explore previous experimental findings where the excitation of a high frequency acoustic wave in the solid anode was found to increase the efficiency of a model system for the process of electro-polishing. The efficiency was measured in terms of the electron current produced in the electrochemical cell which was found to increase by up to a factor of two under the influence of the acoustic wave. However, the increase in efficiency appears to come together with a semi periodic deformation at the surface of the anode. In this presentation, we will discuss the mechanism by which the acoustic wave deforms the diffusive barrier layer near the anode, observed in experiment. We will further show that the deformation of the diffusive barrier supports spatial variations in the rate of diffusion of ions along the diffusive barrier and discuss the convective transfer of ions at low Peclet numbers.