Sodium cobalt oxide

Sodium cobalt oxide, also called sodium cobaltate, is any of a range of compounds of <a href="/facts/Sodium/eYuSPu2V">sodium</a>, <a href="/facts/Cobalt/gqhScEw4">cobalt</a>, and <a href="/facts/Oxygen/acyn6o8r">oxygen</a> with the general formula NaxCoO2 for 0 < x ≤ 1. The name is also used for <a href="/facts/Hydrate/dev82l69">hydrated</a> forms of those compounds, NaxCoO2·yH2O.
The anhydrous compound was first synthesized in the 1970s. It conducts like a metal, and has exceptional <a href="/facts/Thermoelectric_effect/GbRYmwIG">thermoelectric</a> properties (for 0.5 ≤ x ≤ 0.75) combining a large <a href="/facts/Seebeck_coefficient/UCMAJLku">Seebeck coefficient</a> with low <a href="/facts/Resistivity/akyCKvMy">resistivity</a>, as discovered in 1997 by Ichiro Terasaki's research group. A hydrate form was found to be <a href="/facts/Superconductor/pqQAlSzJ">superconducting</a> below 5 <a href="/facts/Kelvin/E3trzC4C">K</a>. The compound, and its manganese analog, could be a cheaper alternative to the analogous <a href="/facts/Lithium/7vXX6BWA">lithium</a> compounds.

Sodium cobalt oxide open-in-new

Sodium cobalt oxide