Electrolytic cell electrons from the cathode and deposits on the cathode as sodium metal. NaCl dissolved in water can also be electrolyzed. The anode oxidizes chloride ions (Cl), and Cl gas is produced. However, at the cathode, instead of sodium ions being reduced to sodium metal, water molecules are reduced to hydroxide ions (OH) and hydrogen gas (H). The overall result of the electrolysis is the production of chlorine gas and aqueous sodium hydroxide (NaOH) solution. Commercially, electrolytic cells are used in electrorefining and electrowinning of several non-ferrous metals. Almost all high-purity aluminium, copper, zinc and lead is produced industrially in electrolytic
Electrochemical cell market will reach 50 GW by 2020. An electrochemical cell consists of two half-cells. Each "half-cell" consists of an electrode and an electrolyte. The two half-cells may use the same electrolyte, or they may use different electrolytes. The chemical reactions in the cell may involve the electrolyte, the electrodes, or an external substance (as in fuel cells that may use hydrogen gas as a reactant). In a full electrochemical cell, species from one half-cell lose electrons (oxidation) to their electrode while species from the other half-cell gain electrons (reduction) from their electrode. A "salt bridge" (e.g., filter paper soaked in