Fast ion conductor
（重定向自Superionic conductor）
![Classification of solid-state ionic conductors by the lg (electronic conductivity, Ωe) – lg (ionic conductivity, Ωi) diagram. 2, 4, and 6 – known solid electrolytes (SEs), materials with Ωi >> Ωe; 1, 3, and 5 – known mixed ion-electron conductors; 3 and 4 – superionic conductors (SICs), i.e. materials with Ωi > 0.001 Ohm−1cm−1, Ωe – arbitrary value; 4 – SIC and simultaneously SE, Ωi > 0.001 Ohm−1cm−1, Ωi >>Ωe; 5 and 6 – advanced superionic conductors (AdSICs), where Ωi > 10−1 Ohm−1cm−1 (300 K), energy activation Ei about 0.1 eV, Ωe – arbitrary value; 6 – AdSIC and simultaneously SE, Ωi > 10−1 Ohm−1cm−1,
Ei about 0.1 eV, Ωi >>Ωe; 7 and 8 – hypothetical AdSIC with Ei ≈ kBT ≈0.03 eV (300 К); 8 – hypothetical AdSIC and simultaneously SE.](/Images/godic/202502/14/Electronic_ionic_conductivity_diagram2255.JPG")
In materials science, fast ion conductors are solids in which ions are highly mobile. These materials are important in the area of solid-state ionics, and are also known as solid electrolytes and superionic conductors. These materials are useful in batteries and various sensors. Fast ion conductors are used primarily in solid oxide fuel cells. As solid electrolytes they allow the movement of ions without the need for a liquid or soft membrane separating the electrodes. The phenomenon relies on the hopping of ions through an otherwise rigid crystal structure.