Electrolysis in a closed electrochemical cell with a small inter-electrode distance. Metal dissolution/deposition in plain electrolytes

The present paper focuses on the specificity of electrolysis during metal dissolution/deposition in a closed electrochemical cell with a small inter-electrode distance. A mathematical model for the electrochemical process in such a cell has been developed. We give an analytical and a numerical solution to the system of mass transfer equations for such a cell, in binary solutions and solutions with supporting electrolyte. The dependence of metal deposition rate on the voltage applied to the cell and on the electrolysis time has been studied by numerical simulation. We also present the results of the experimental study of the rate of silver electrodeposition from an acid solution of AgClO4 in a cell of size 1 mm × 1 mm. Metal deposition rate in a closed electrochemical cell with a small inter-electrode distance has been demonstrated to be at least three times higher than that at recessed electrodes. The results obtained may be used in the LIGA processes for accelerating the filling of photoresist cavities with metal.