Electrochemistry in the Electrochemical Cells: There is More than Just the Working Electrode

The tacit assumption in an electrochemical experiment is that a properly set up electrochemical cell, working electrode, counter electrode, reference electrode and a potentiostat, will perform an experiment by "applying potential on the working electrode" without any need to consider the properties of the reference electrodes, the effect of electrochemistry on the counter electrode and the real properties of the potentiostat. While this is in first approximation a valid assumption, in the extremes it is also necessary to consider the other parts of the system. In this work we visit two interesting cases that may lead to experimental artifacts. The first is the effect of electrochemical solution changes during impedance measurement. The second is effect of the time constant of a reference electrode on an impedance measurement in an electrochemical cell.