Current Distribution, Porous and Rough Electrodes— the Effect of Geometry

6 Current Distribution, Porous and Rough Electrodes—the Effect of Geometry 

It was pointed out in Section 2.1.2.4 that in most electrochemical systems, including those situations in which there is a concentration gradient but in which regions close to interfaces between different phases are excluded, electroneutrality is a reasonable assumption. Under these circumstances, the potential variation is given by Laplace s equation 

In principle, this equation may be solved subject to the following boundary conditions  

4 = constant (conducting boundary) d /dn = constant (insulating boundary) 

The potential and current distributions derived from these boundary conditions are called the primary distribution. They depend only on the geometry of the system. For very simple geometries, analytical solutions to Laplace s equation have been 

---