Ionic conductivity (denoted by ) is a measure of a substance's tendency towards ionic conduction. Ionic conduction is the movement of ions. The phenomenon is observed in solids and solutions. Ionic conduction is one mechanism of current.

In crystalline solids

In most solids, ions rigidly occupy fixed positions, strongly embraced by neighboring atoms or ions. In some solids, selected ions are highly mobile allowing ionic conduction. The mobility increases with temperature. Materials exhibiting this property are used in batteries. A well-known ion conductive solid is β''-alumina ("BASE"), a form of

aluminium oxide Aluminium oxide (or aluminium(III) oxide) is a chemical compound of aluminium and oxygen with the chemical formula . It is the most commonly occurring of several Aluminium oxide (compounds), aluminium oxides, and specifically identified as alum ...

that has channels through which sodium cations can hop. When this

ceramic A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcela ...

is complexed with a mobile ion, such as Na⁺, it behaves as so-called fast ion conductor. BASE is used as a

membrane A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Bi ...

in several types of molten salt

electrochemical cell An electrochemical cell is a device that either generates electrical energy from chemical reactions in a so called galvanic cell, galvanic or voltaic cell, or induces chemical reactions (electrolysis) by applying external electrical energy in an ...

History

Ionic conduction in solids has been a subject of interest since the beginning of the 19th century.

Michael Faraday Michael Faraday (; 22 September 1791 – 25 August 1867) was an English chemist and physicist who contributed to the study of electrochemistry and electromagnetism. His main discoveries include the principles underlying electromagnetic inducti ...

established in 1839 that the laws of

electrolysis In chemistry and manufacturing, electrolysis is a technique that uses Direct current, direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of c ...

are also obeyed in ionic solids like lead(II) fluoride () and silver sulfide (). In 1921, solid silver iodide () was found to have had extraordinary high ionic conductivity at temperatures above 147 °C, AgI changes into a phase that has an ionic conductivity of ~ 1 –1 cm⁻¹. This high temperature phase of AgI is an example of a superionic conductor. The disordered structure of this solid allows the Ag⁺ ions to move easily. The present record holder for ionic conductivity is the related material . β''-alumina was developed at the

Ford Motor Company Ford Motor Company (commonly known as Ford) is an American multinational corporation, multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. T ...

in the search for a storage device for

electric vehicle An electric vehicle (EV) is a motor vehicle whose propulsion is powered fully or mostly by electricity. EVs encompass a wide range of transportation modes, including road vehicle, road and rail vehicles, electric boats and Submersible, submer ...

s while developing the sodium–sulfur battery.

References

External links

J Chem Phys
Physical quantities Electrochemistry {{electrochem-stub

In crystalline solids

History

See also

References

External links