Electrolysis is used to drive an oxidation-reduction reaction in a direction in which
it does not occur spontaneously by driving an electric current through the system while doing
work on the chemical system itself, and therefore is non-spontaneous.
Electrolytic cells, like galvanic cells, are composed of two half-cells--one is a reduction half-cell,
the other is an oxidation half-cell. The direction of electron flow in electrolytic cells, however,
may be reversed from the direction of spontaneous electron flow in galvanic cells, but the
definition of both cathode and anode remain the same, where reduction takes place at the cathode
and oxidation occurs at the anode. Because the directions of both half-reactions have been
reversed, the sign, but not the magnitude, of the cell potential has been reversed.
positive or oxidizing electrode that acquires electrons from the external circuit and is reduced during the electrochemical reaction.
medium that provides the ion transport mechanism between the cathode and anode of a cell. Electrolytes are thought of as liquids, such as water or other solvents, with dissolved salts, acids, or alkalis that are required for ionic conduction. That many batteries including the conventional (AA/AAA/D) contain solid electrolytes that act as ionic conductors at room temperature.