Effects Due to Capacity and Resistance

Cyclic voltammetric data, even when using a three-electrode potentiostat form of instrumentation, can be affected by the presence of uncompensated resistance in the solution phase between the reference and the working electrode and of the working electrode itself, and by the capacity of the working electrode. A simple electrochemical cell may be described by an equivalent circuit, in which electronic components are used to describe the behaviour of the cell [58]. In Fig. II. 1.11 the uncompensated solution resistance and the double-layer capacity at the working electrode are represented by and respectively. More complex, but more realistic, equivalent circuits have been proposed [59] (see also Chap. II.5). 

In Fig. II. 1.12, cyclic voltammograms incorporating both IRu drop and capacitance effects are shown. Effects for the ideal case of a potential independent 

---