Lithium nitride of increased conductivity, method for its preparation, and its use
AssigneeMax-Planck-Gesellschaft
InventorsJochen Wahl, Alfred Breitschwerdt
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Abstract
Crystalline lithium nitride of increased conductivity having a hydrogen content of 0.2 to about 8 mole percent, a sodium, potassium and calcium content each of less than 10.sup.-2 weight percent and a silicon and iron content each between 10.sup.-2 to 10.sup.-3 weight percent, the metallic lithium from which said crystalline lithium was prepared having been of at least 99.9 weight percent purity.
Claims11
Crystalline lithium nitride of increased conductivity comprising 0.2 to about 8 mole percent of hydrogen, a sodium, potassium, and calcium content each of less than 10.sup.-2 weight percent and a silicon and iron content each between 10.sup.-2 to 10.sup.-3 weight percent, the metallic lithium from which said crystalline lithium nitride was prepared having been of at least 99.9 weight percent purity.
Method of preparing crystalline lithium nitride of increased conductivity from lithium metal of at least 99.9 weight percent purity comprising the steps of heating the lithium metal to a temperature of 140.degree. C. to 180.degree. C. in an inert vessel in the presence of sufficient hydrogen for complete reaction with the lithium metal, at a nitrogen pressure of at least 250 mm Hg and, after the onset of the reaction, increasing the temperature to the melting point of lithium nitride;
- or heating said lithium metal in the presence of hydrogen at a nitrogen pressure of at least 250 mm Hg, but below atmospheric pressure to a temperature above 300.degree. C., in said inert vessel, said inert vessel being formed of tungsten, niobium, ruthenium or tantalum;
- said hydrogen being present in an amount in excess of 0.2 to about 8 moles, per mole of lithium nitride.
In a method of regulating the conductivity of crystalline lithium nitride which is obtained by the reaction of metalic lithium with nitrogen at a temperature of about 140.degree. to 180.degree. C. in an inert vessel the steps comprising adding, to the reaction, hydrogen in molecular form or in the form of a compound with one of the two reactants, in such an amount that a hydrogen content corresponding to the desired conductivity and in the range of 0.2 to 8 mole percent is put in a dopant.
Dependencies are inferred from the claim text.