If the liquid is a solution that contains a metal, electrolysis breaks up the solution so that the metal is removed. The electrolysis of metallic solutions is useful in putting metal coatings on objects, and in refining, or purifying, metals. How electrolysis works. To produce electrolysis, two solid electrical conductors, such as metal or graphite rods, are placed into a liquid. The rods are called electrodes.
Wires connect the electrodes to the terminals of a battery or to a direct current generator.
The liquid must contain a substance, called an electrolyte, that enables it to carry the current and complete the electrical circuit. For example, distilled water cannot be electrolyzed because it does not conduct electricity well. The electrodes, the liquid, and the container that holds them make up an electrolytic cell. The electrode connected to the battery's negative pole is the cathode. It carries electrons from the battery to the electrolytic cell.