Add bubbling at the electrolyte-cathode-anode interfaces to random thermal motion
plus Seebeck-Peltier-Thomson, and Contact Potential Effects, there are
plenty of "Over-Unity" artifacts to consider.
This excellent 44 page pdf covers Electrokinetic Phenomena, nicely.
Fred
http://www.era.lib.ed.ac.uk/bitstream/1842/286/3/grant90-3.pdf
An ion or charged particle in an electrolyte exerts an influence on its immediate
environment by virtue of its electric field. This electric field causes dipolar
molecules in the immediate vicinity to orientate themselves according to the sign
of the charge, like charged ions (co-ions) to be repelled from the area whereas
oppositely charge ions (counter-ions) experience an attractive potential. As a
consequence of the attractive potential counter ions would be expected to
approach the charge until the smallest possible distance was achieved. However,
the random thermal motion of ions in solution acts against this tendency. This
combination of electrical potential energy and thermal energy gives rise to a
locally organised region of electrolyte, whereby the ionic distribution in the
vicinity of the charge results from the relative magnitudes of the two opposing
factors. The resulting locally modified region is referred to, in the case of an ion,
as the ionic atmosphere of the ion. Many solid surfaces, such as glass or most
metals, acquire a charge through self ionisation when in contact with an
electrolyte. In this case the surface together with its associated structured region
of electrolyte is known as the electrical double layer. The latter is largely
responsible for many of the observed electrokinetic effects and therefore merits
some consideration. Here, the term electrokinetic effects is used as a
Stem-Gouy-Chapman Model of the Electrical Double Layer
In this model, which is depicted graphically by figure 3.1, the electrical double
layer is viewed as consisting of two distinct regions, whereby the excess charges in
the electrolyte are distributed between a layer of counter ions (the rigid layer)
situated at the shortest possible distance from the charged surface and a diffuse
layer.
Diffuse Layer
In this model of the diffuse part of the double layer the surface is considered to
be flat and of infinite area. For such a hypothetical surface, in a vacuum, the
electric field at any distance would be constant and thus the potential at any
point would be infinite. Here, the potential is defined as the work done, per unit
charge, in bringing a point charge dq from an infinite distance to its present
position. In an electrolyte however, the presence of excess counter ions in the
electrical double layer causes the field to drop with distance from the surface and
thus the potential has a finite value.
