Cells for Cyclic Voltammetry and Chronoamperometry

As noted above, a symmetric disposition of the electrodes in the electrochemical cell considerably reduces the problems connected with the control of the potential of the working electrode. 

One must keep in mind that modern electrochemical instrumentation compensates for the potential drop i (Rn + Rnc) through the use of appropriate circuitry (positive feedback compensation). This adds a supplementary potential to the input potential of the potentiostat (equal to the ohmic drop of the potential), which is generated by taking a fraction of the faradaic current that passes through the electrochemical cell, such that in favourable cases there will be no error in the control of the potential. However, such circuitry can give rise to problems of reliability in the electrochemical response on occasions when an overcompensation is produced. 

It is often useful to carry out voltammetric measurements at low temperatures in order to evaluate both the stability of an electrogenerated species (the decrease in temperature will slow down the kinetics of any decomposition processes of the species formed in the electrode process) and the variation in formal electrode potential of a redox couple as a function of temperature. The latter point regards thermodynamic considerations of the redox processes, which will be discussed in Chapter 13, Section 3. 

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