Lithium oxide (Li2O) or lithia is an inorganic chemical compound. It is a white solid. Although not specifically important, many materials are assessed on the basis of their Li2O content. For example, the Li2O content of the principal lithium mineral spodumene (LiAlSi2O6) is 8.03%.
Production
Lithium oxide forms along with small amounts of lithium peroxide when lithium metal is burned in the air and combines with oxygen at temperatures above 100 °C:2
4Li + O2 → 2Li2O.Pure Li2O can be produced by the thermal decomposition of lithium peroxide, Li2O2, at 450 °C34
2Li2O2 → 2Li2O + O2Structure
Solid lithium oxide adopts an antifluorite structure with four-coordinated Li+ centers and eight-coordinated oxides.5
The ground state gas phase Li2O molecule is linear with a bond length consistent with strong ionic bonding.67 VSEPR theory would predict a bent shape similar to H2O.
Uses
Lithium oxide is used as a flux in ceramic glazes; and creates blues with copper and pinks with cobalt. Lithium oxide reacts with water and steam, forming lithium hydroxide and should be isolated from them.
Its usage is also being investigated for non-destructive emission spectroscopy evaluation and degradation monitoring within thermal barrier coating systems. It can be added as a co-dopant with yttria in the zirconia ceramic top coat, without a large decrease in expected service life of the coating. At high heat, lithium oxide emits a very detectable spectral pattern, which increases in intensity along with degradation of the coating. Implementation would allow in situ monitoring of such systems, enabling an efficient means to predict lifetime until failure or necessary maintenance.
Lithium metal might be obtained from lithium oxide by electrolysis, releasing oxygen as by-product.
Reactions
Lithium oxide absorbs carbon dioxide forming lithium carbonate:
Li2O + CO2 → Li2CO3The oxide reacts slowly with water, forming lithium hydroxide:
Li2O + H2O → 2LiOHSee also
External links
References
Wietelmann, Ulrich and Bauer, Richard J. (2005) "Lithium and Lithium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim. doi:10.1002/14356007.a15_393. /wiki/Doi_(identifier) ↩
Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. pp. 97–99. ISBN 978-0-08-022057-4. 978-0-08-022057-4 ↩
Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. pp. 97–99. ISBN 978-0-08-022057-4. 978-0-08-022057-4 ↩
Wietelmann, Ulrich and Bauer, Richard J. (2005) "Lithium and Lithium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim. doi:10.1002/14356007.a15_393. /wiki/Doi_(identifier) ↩
Zintl, Eduard; Harder, A.; Dauth, B. (1934). "Gitterstruktur der Oxyde, Sulfide, Selenide und Telluride des Lithiums, Natriums und Kaliums". Zeitschrift für Elektrochemie und Angewandte Physikalische Chemie (in German). 40 (8): 588–593. doi:10.1002/bbpc.19340400811. S2CID 94213844. /wiki/Eduard_Zintl ↩
Wells A. F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6 /wiki/ISBN_(identifier) ↩
A spectroscopic determination of the bond length of the LiOLi molecule: Strong ionic bonding, D. Bellert, W. H. Breckenridge, J. Chem. Phys. 114, 2871 (2001); doi:10.1063/1.1349424 /wiki/Doi_(identifier) ↩