Chronopotentiometry double layer charging

This would suggest that chronopotentiometry could be a sensitive electroanalytical technique. It is rarely used in this context, however, since it is often difficult to determine the transition time accurately, because of double-layer charging at short times and competing reactions at long times. The same limitations apply when one attempts to use Eq. 49K to measure the diffusion coefficient. On the other hand this equation can be used as a quick method of obtaining n,... 

Figure 6.19 Current- and potential-time dependence in chronopotentiometry. The double-layer charging retards the potential increase and can, similar to chronoamperometry, distort the extrapolation.

In chronopotentiometry, after switching on a current, the time dependence of the potential is monitored. Potential- and current-time dependence are shown schematically in Figure 6.19. Similar to chronoamperometry, the charging of the double layer can overshadow the region of charge-controlled behavior. 

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