Electrolysis

Electrolysis is a chemical process that uses a direct electric current passed through an electrolyte, a substance containing free-moving ions, to drive a chemical reaction that would not occur on its own, separating a compound into its constituent elements at two electrodes connected to an external power source. The English scientists William Nicholson and Anthony Carlisle carried out the first sustained electrolysis in 1800, splitting water into hydrogen and oxygen using a voltaic pile, and Humphry Davy used electrolysis between 1807 and 1808 to discover the elements potassium, sodium, barium, calcium, and magnesium; Michael Faraday coined the term electrolysis itself in 1834. The technique became industrially transformative with the 1886 development of the Hall-Heroult process for producing aluminum by electrolysis, which cut the metal's price from roughly four dollars to thirty cents a pound, and electrolysis remains central to metal refining and the industrial production of many chemical compounds.