The Current Density Distribution in Homogeneous Fields

The current density distribution between parts of the electrode surface with smaller and larger distance between cathode and anode can be calculated using the following procedure [1]  

It follows from Eq. (3.3) that the dominant effect on current distribution is the effect of the resistivity of the solution. 

On the other hand, if the electrochemical part of Eqs. (3.1) and (3.2) can be neglected relative to the ohmic voltage drop, complete ohmic control appears and the relation  

An estimation of the effect of different parameters on the current density distribution can be made from Fig. 3.2, which shows the dependencies of the current densities at the closer, / and further, if, part of the cathode from the anode on the cell voltage, (/, for different solution resistivity. As can be seen, the increase of the conductivity of the electrolyte leads to the more uniform current density distribution of deposits at the electrode surface. A similar but less pronounced effect of the increase of the cathodic Tafel slope can be seen, while the change of /q does not affect the current density distribution. It is necessary to note that a soluble anode is considered in this case and, hence, the anodic and cathodic exchange current densities are the same. 

Finally, the effect of the hjl ratio will be discussed. As expected, for hjl 0, the current density distribution approaches to a uniform one, while for /i// 1, it is similar to the primary current distribution. Based on the above results, it follows that the ohmic resistance of the solution is the most important parameter producing 

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