What Is Lithium Oxide?
Lithium oxide is an oxide of lithium with the composition Li2O.
It has a molecular weight of 29.881, a melting point of 1,570°C, and a boiling point of 2,600°C. It is a colorless crystal at room temperature. The CAS registration number is 12057-24-8.
Uses of Lithium Oxide
Lithium oxide is mainly used during the manufacture of conductive glass, batteries, and solid electrolytes. It is also used in glazes, where it is mixed with copper to produce blue colors and with cobalt to produce pinks.
In thermal barrier coatings (TBCs), they may be used for nondestructive emission spectrometry testing and degradation evaluation. In zirconia coatings, it is used as a doping agent together with yttrium oxide.
Properties of Lithium Oxide
Lithium oxide is an ionic crystal composed of the lithium ion Li+ and the oxide ion O2-. It has a density of 2.013 g/mL and reacts with water (exothermic reaction) to form lithium hydroxide. Lithium Oxide is thermodynamically more stable than other alkali metal oxides.
Its crystal structure is cubic, with an inverted fluorite-type structure. This structure is similar to that of potassium oxide and sodium oxide. Lithium Oxide has a lattice constant of a = 4.61 Å. The lithium ion Li+ has a tetrahedral 4-coordination and the oxide ion O2- has a cubic 8-coordination.
Types of Lithium Oxide
Lithium oxide is sold primarily as a reagent product for research and development. The types of capacities include 5g, 10g, 25g, 100g, and 500g, and it is offered in capacities that are easy to handle in the laboratory.
Although highly reactive with water and highly hygroscopic, it is stable in an appropriate storage environment and is usually treated as a reagent product that can be stored at room temperature. It is sometimes sold in an argon-filled state.
Other Information on Lithium Oxide
1. Synthesis of Lithium Oxide
Lithium oxide can be synthesized by burning metallic lithium in air or in oxygen. Lithium peroxide Li2O2 and lithium superoxide LiO2 are not produced in the reaction with oxygen, as in this reaction.
Other methods include synthesis as a decomposition product by heating anhydrous lithium hydroxide wrapped in silver foil in a nickel boat at 675°C under reduced pressure, lithium carbonate (heated at 700°C under reduced pressure for 50 hours), and anhydrous lithium peroxide (heated in helium at 450°C for 6 hours) (heated at 700°C for 50 hours under reduced pressure) or anhydrous lithium peroxide (heated at 450°C for 6 hours in helium).
2. Chemical Reaction of Lithium Oxide
Lithium oxide is a substance that easily absorbs water vapor and carbon dioxide. The reaction with carbon dioxide produces lithium carbonate. It also reacts gradually with water to give lithium hydroxide.
Since it can be altered by light, high temperatures and direct sunlight should be avoided in the storage environment. In addition, strong oxidizers are a miscibility hazard, and the hazardous decomposition products assumed are metal oxides. 3.
3. Hazardousness of Lithium Oxide and Regulatory Information
Lithium oxide is classified under the following GHS classifications:
- Acute toxicity—inhalation (dust/mist): Category 3
- Skin corrosion/irritation: Category 1
- Serious eye damage/eye irritation: Category 1
- Reproductive toxicity: Category 1A
- Specific target organ toxicity (single exposure): Category 1
As described above, this substance is highly hazardous to the human body. When handling, use appropriate personal protective equipment such as protective goggles, gloves, and dust masks, and ventilate well in the operating environment.
Wash exposed skin, including face and hands, after handling. In case of contact with the eyes, the eyes must first be carefully rinsed with water for several minutes regardless of whether contact lenses are worn or not.