Lithium sulfide production method

Patent metadata

Field	Value
Publication number	US-2023150819-A1
Application number	US-202217988677-A
Country	US
Kind code	A1
Filing date	Nov 16, 2022
Priority date	Nov 16, 2021
Publication date	May 18, 2023
Grant date	—

Abstract

A process for producing a low-cost water-reactive sulfide material includes reacting a substantially anhydrous first alkali metal salt, a substantially anhydrous first sulfide compound, and a substantially anhydrous first alkali metal hydrosulfide compound in a substantially anhydrous polar solvent, providing differential solubility for a substantially high solubility second sulfide and a substantially low solubility second alkali metal salt, and forming a mixture of the high solubility second sulfide, a second alkali metal hydrosulfide, and the low solubility second alkali metal salt; removing the low solubility second alkali metal salt to isolate the supernatant including the second sulfide, and separating the polar solvent from the second sulfide and the second alkali metal hydrosulfide followed by heating to produce the second sulfide. The present disclosure provides a scalable process for production of a high purity alkali metal sulfide that is essentially free of undesired contaminants.

First claim

We claim:

1 . A method for producing a water-reactive alkali metal sulfide comprising:
(a) reacting a first alkali metal salt and a first alkali metal hydrosulfide and optionally a first sulfide in a polar solvent to produce a mixture comprising a second sulfide and a second alkali metal salt precipitate; (b) removing the precipitated second alkali metal salt from the mixture to produce a supernatant comprising the second sulfide and the polar solvent; and, (c) removing the polar solvent from the supernatant.

2 . The method of claim 1 , wherein the removing the polar solvent from the supernatant comprises evaporating the polar solvent to produce a powder.

3 . The method of claim 2 , wherein the evaporating comprises drying the powder to remove substantially all of the polar solvent.

4 . The method of claim 2 , wherein over 99% by weight of the polar solvent from the powder is removed.

5 . The method of claim 1 , wherein the removing the polar solvent from the supernatant comprises spray drying, rotary drying, tray drying, fluidized bed drying, vacuum drying, or a combination thereof.

6 . The method of claim 1 , further comprising adding a sulfur source to increase the purity of the second sulfide.

7 . The method of claim 6 , wherein the sulfur source comprises one or more of elemental sulfur and H 2 S.

8 . The method of claim 6 , wherein the sulfur source is added at any step of the method prior to or during the removing of the polar solvent from the supernatant.

9 . The method of claim 6 , wherein the second sulfide is at least 95% free by weight from Li 3 OCl contaminant.

10 . The method of claim 1 , wherein the supernatant further comprises a second alkali metal hydrosulfide.

11 . The method of claim 10 , comprising heating the second alkali metal hydrosulfide to produce the second sulfide and hydrogen sulfide.

12 . The method of claim 10 , wherein the second alkali metal hydrosulfide comprises LiHS.

13 . The method of claim 1 , further comprising introducing an anti-solvent compound to the supernatant prior to or directly following the precipitation of the second alkali metal salt.

14 . The method of claim 13 , wherein the anti-solvent is selected from the group consisting of hydrocarbon-based solvents, non-polar solvents, solvents with substantial miscibility in the polar solvent, solvents that increase the differential solubility of one or more of the second sulfide and second alkali metal hydrosulfide in the polar solvent in comparison to the second alkali metal salt, and combinations thereof.

15 . The method of claim 1 , wherein removing the second alkali metal salt from the supernatant comprises at least one of centrifuging, filtering, gravity settling, and cooling.

16 . The method of claim 1 further comprising reducing an amount of the polar solvent from the supernatant, wherein reducing comprises at least one of evaporating the polar solvent, heating the polar solvent, or reducing atmospheric pressure surrounding the supernatant.

17 . The method of claim 1 further comprising increasing the relative amount of the first alkali metal salt, the first sulfide compound, or the first alkali metal hydrosulfide compound to increase purity of the second sulfide to greater than 95% by weight.

18 . The method of claim 1 , wherein the polar solvent is substantially anhydrous.

19 . The method of claim 1 , wherein the first alkali metal hydrosulfide is substantially anhydrous.

20 . The method of claim 1 , wherein the ratio of masses of the first alkali metal hydrosulfide and the water incorporated therein is greater than 2:1.

21 . The method of claim 1 , wherein the ratio of masses of the first alkali metal hydrosulfide and the water incorporated therein is greater than 3:1.

22 . The method of claim 1 , wherein the ratio of masses of the first alkali metal hydrosulfide and the water incorporated therein is greater than 4:1.

23 . The method of claim 1 , wherein the polar solvent comprises at least one alcohol selected from the group consisting of ethanol, 1-propanol, 1-butanol, and mixtures thereof.

24 . The method of claim 1 , wherein the first alkali metal salt comprises LiCl, the first alkali metal hydrosulfide comprises NaHS, and the first sulfide comprises Na 2 S.

25 . The method of claim 1 , wherein the second alkali metal salt comprises NaCl and the second sulfide comprises Li 2 S.

26 . The method of claim 1 , wherein the first alkali metal salt and the first sulfide are separately dissolved in aliquots of the polar solvent, which separate aliquots are then combined to form a mixture prior to adding the first alkali metal hydrogen sulfide.

27 . The method of claim 1 , wherein the first alkali metal salt, the first sulfide compound, and the first alkali metal hydrosulfide are independently dissolved in the polar solvent prior to reacting them together.

28 . The method of claim 1 , wherein the first alkali metal salt or the first sulfide is first dissolved in the polar solvent then the other is added in solid form.

29 . The method of claim 1 , wherein one of the first alkali metal salt, the first sulfide, and the first alkali metal hydrosulfide is dissolved in the polar solvent and the others are added to the solution in solid form.

30 . The method of claim 1 , wherein the ratio of the solubility of the second sulfide to the solubility of the second alkali metal salt in the polar solvent is at least 90:10.

31 . The method of claim 1 , wherein the ratio of the solubility of the second sulfide to the solubility of the second alkali metal salt in the polar solvent is at least 97:3.

32 . The method of claim 1 , wherein the ratio of the solubility of the second sulfide to the solubility of the second alkali metal salt in the polar solvent is at least 99:1.

33 . The method of claim 1 , wherein the ratio of the solubility of the second sulfide to the solubility of the second alkali metal salt in the polar solvent is at least 99.9:0.1.

34 . The method of claim 1 , wherein the first sulfide compound is selected from the group consisting of K 2 S, Na 2 S, (NH 4 ) 2 S, and mixtures thereof.

35 . The method of claim 1 , wherein the first alkali metal hydrosulfide compound is selected from the group consisting of KHS, NaHS, LiHS, and mixtures thereof.

36 . The method of claim 1 , wherein the second sulfide comprises Li 2 S.

37 . The method of claim 1 , wherein the second sulfide comprises a purity of 95% or greater.

38 . The method of claim 1 , wherein the second sulfide has a mass loss of less than 10% when heated above 100° C.

39 . The method of claim 1 , wherein the second sulfide has a mass loss of less than 13% when heated above 340° C.

40 . A solid state electrolyte comprising the second sulfide produced by the method of claim 1 .

41 . The method of claim 1 , wherein the produced mixture further comprises LiNaS.

42 . The method of claim 1 , wherein the produced mixture further comprises Li 2 MgS 2 .

43 . The method of claim 1 , wherein the produced mixture further comprises Li 2 CaS

Assignees

• Solid Power Operating Inc

Inventors

• Francisco Brian E
• Oberwetter Samuel
• Culver Sean P
• Lisenker Ilya

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• C01P2006/80

  Compositional purity · CPC title

• H01M2300/0068

  inorganic · CPC title

• H01M10/0562

  Solid materials · CPC title

• C01D15/00

  Lithium compounds · CPC title