The kinetics of electrochemical reactions is controlled by diffusion processes of charge carriers across a boundary layer
between the electrode and the electrolyte, which result in a shielding of the electric field inside the electrolyte and a
concentration gradient across this boundary layer. In accumulators the diffusion rate determines the rather long time
needed for charging, which is a major drawback for electric mobility. This diffusion boundary can be removed by
acoustic streaming in the electrolyte induced by surface acoustic waves propagating of the electrode, which results in an
increase of the charging current and thus in a reduction of the time needed for charging.
For a quantitative study of the influence of acoustic streaming on the charge transport an electropolishing cell with
vertically oriented copper electrodes and diluted H<sub>3</sub>PO<sub>4</sub>-Propanol electrolytes were used. Lamb waves with various
excitation frequencies were exited on the anode with different piezoelectric transducers, which induced acoustic
streaming in the overlaying electrolytic liquid. An increase of the polishing current of up to approximately 100 % has
been obtained with such a set-up.