The Very Edge Ohmic Resistance

This consideration of the very edge current density can be elaborated mathematically in the following way [5] assuming the total ohmic control, the voltage drop in the solution between the electrodes inside the homogeneous field is given by 

The difference in the current lines outside the homogeneous field is given by 

When Eq. (3.16) is integrated from the inter-electrode distance I to the maximum length of the current line, I, the maximum contribution to the edge current density due to current line propagation between the electrode edges and the side walls of the cell, is obtained as 

Combining Eqs. (3.19) and (3.20), the maximum edge current density can be given as 

This means that the very edge resistance is lower than in the homogeneous field and that the minimum effective inter-electrode distance, /eff.e.mim between the edges of the anode and cathode will be 

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