Galvanic cell bridge zinc ions leave and anions enter the zinc half-cell. In the copper half-cell, the copper ions plate onto the copper electrode (reduction), taking up electrons that leave the external conductor. Since the Cu ions (cations) plate onto the copper electrode, the latter is called the cathode. Correspondingly the zinc electrode is the anode. The electrochemical reaction is: In addition, electrons flow through the external conductor, which is the primary application of the galvanic cell. As discussed under #Cell voltage, the emf of the cell is the difference of the half-cell potentials, a measure of the relative ease of dissolution
Electrolytic capacitor relatively high capacitance values of electrolytic capacitors compared with other capacitor families. Because the forming voltage defines the oxide layer thickness, the desired voltage rating can be produced very simply. Electrolytic capacitors have high volumetric efficiency, the so-called "CV product", defined as the product of capacitance and voltage divide by volume. Combinations of anode materials for electrolytic capacitors and the electrolytes used have given rise to wide varieties of capacitor types with different properties. An outline of the main characteristics of the different types is shown in the table below. The non-solid or so-called "wet" aluminum electrolytic capacitors were and