Copper Electrodeposition Dynamics at a Porous Flow-through Electrode

Abstract

The dynamics of the copper electrodeposition out of a dilute sulfuric acid solution of copper sulfate (straight-through regime, solution supplied from the rear at a velocity of ~1 cm s -1 ) onto preliminarily metallized carbonaceous felt of the VINN-250 brand is studied. The profile, which describes the final deposit distribution, qualitatively conforms to predictions made in terms of a dynamic model for a porous electrode described previously, as does the nonmonotonic variation of the gain in the copper weight and the current efficiency for copper with time in the first half of the deposition process. At later stages of the process, along with the enhancement of the tendency towards the forcing of the copper electrodeposition process towards the front end of the electrode, there appears a new factor, which is not taken into account by the method. This factor is the deposition of a loose rough copper layer outside the porous electrode at its front side.

Dynamics of two-metal codeposition inside a flow-through porous electrode at a high solution flow rate

“…The results obtained with the help of this model revealed some peculiarities of the dynamics of PE filling with metal, which are in qualitative agreement with the experimental data [10,11]. Taking this into account, it appears reasonable to expand the dynamic model to the discharge of several metals and to use the model for revealing more realistic regularities of the simultaneous deposition of metals inside the PE, which is the major goal of the present work.…”

“…Changes in PE parameters during metal deposition were taken into account in the dynamic model of the PE [8,9]. The results obtained with the help of this model revealed some peculiarities of the dynamics of PE filling with metal, which are in qualitative agreement with the experimental data [10,11].…”

“…The working solution was prepared from reagents pure for analysis and triply distilled water, and the cylindrical flow-through electrochemical cell with the electrode spaces separated by a cation-exchange membrane MK-40 was used as an electrolyzer [10]. This allowed us to avoid the transfer of sulfite and thiosulfate anions into the anolyte and their subsequent oxidation.…”

“…The dynamic model describing the deposition of a single metal inside the PE [8,9] is based on a unidimensional representation of the PE as a system of parallel cylindrical filaments. The model takes into account an increase in the local filament radius r f (x) during metal electrodeposition as well as the consequent changes in local porosity, linear solution flow rate, mass transfer coefficient of the discharging ions, and the effective conductivity of the solid phase.…”

“…The model takes into account an increase in the local filament radius r f (x) during metal electrodeposition as well as the consequent changes in local porosity, linear solution flow rate, mass transfer coefficient of the discharging ions, and the effective conductivity of the solid phase. A more detailed description of the model is presented in Appendix A -Supplementary data associated with [12] (can be found in the online version at doi: 10.1016/j.jelechem.2008.07.006). When correcting the dynamic model with respect to the process of the codeposition of several (two, for simplicity) metals, we made changes to the equation of the total cathode polarization curve.…”