The interplay between the electromagnetism and chemistry within an electrochemical cell (a
‘battery’) is modelled in such a way so as to describe both open and closed circuit conditions. It
is found that a classical field theory coupled with a generic model of the chemistry can
consistently explain the behaviour of the cell and reproduce standard results. But this model also
reveals an interesting interplay between time scales (field and chemical) that leads to a capacitive
impedance within the cell. The assumption that the stasis associated with the emf results from the
inability of ions to overcome the potential barriers near each electrode is abandoned. Rather, the
equilibrium is viewed as dynamic and results from a balance between forward and reverse chemical
reactions. Ions are able borrow enough energy to overcome the barriers as predicted by quantum
theory to fuel the forward reactions. The probability of transmission (i.e. ‘tunnelling’) is
calculated using a method based…