IP Library › Granted Patent US 12,467,152
Granted Patent B2
US 12,467,152 · App. 17/795,646 · Granted Nov 11, 2025

Lithium recovery from lithium salts dissolved in ionic liquids

Inventors: David W. Hatchett (Las Vegas, NV); Cassara J. Higgins (Las Vegas, NV)
Assignee: THE BOARD OF REGENTS OF THE NEVADA SYSTEM OF HIGHER EDUCATION ON BEHALF OF THE UNIVERSITY OF NEVADA, LAS VEGAS
C25C1/22C25C7/02
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Quick Facts
Patent No.
US 12,467,152
App. No.
17/795,646
Granted
Nov 11, 2025
Kind
B2
Abstract

Described herein are methods for recovering lithium metal, lithium hydride, or lithium hydroxide from lithium salts by dissolving the lithium salt in ionic liquids and applying a current to the solution.

Claims (19)

1 . A method for recovering lithium, comprising:

combining a lithium salt and a nonaqueous acid in water and then dehydrating to form a dehydrated composition comprising the lithium salt and the nonaqueous acid;

sparging an ionic liquid with an inert gas to remove water and CO 2 and adding the sparged an ionic liquid to the dehydrated composition comprising the lithium salt and the nonaqueous acid to form an ionic liquid composition; and

applying a potential to the ionic liquid composition to deposit lithium onto an electrode.

2 . The method of claim 1 , where the inert gas is selected from argon, helium, neon, krypton, and xenon.

3 . The method of claim 1 , wherein the lithium salt is Li 2 CO 3 , LiCl, LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , or LiCF 3 SO 3 , or combinations thereof.

4 . The method of claim 1 , wherein the lithium concentration in the ionic liquid comprises about 0.1 M, 0.25 M, 0.5 M, 0.75 M, 1.0 M, 1.5 M, 2.0 M, 2.5 M, 3.0 M, 3.5 M, 4.0 M, 4.5 M, 5.0 M, 5.5 M, 6.0 M, 6.5 M, or 7.0 M.

5 . The method of claim 1 , wherein the anion of the ionic liquid and the anion of the nonaqueous acid comprise the same anionic moiety.

6 . The method of claim 1 , wherein the nonaqueous acid is n-bis(trifluoromethanesulfonylimide) acid (HTFSI).

7 . The method of claim 1 , wherein the ionic liquid comprises an n-bis(trifluoromethanesulfonylimide) (TFSI) anion.

8 . The method of claim 1 , wherein the ionic liquid comprises a cation that does not undergo reductive decomposition at a potential between −2.5 and −4.5 V.

9 . The method of claim 1 , wherein the ionic liquid comprises a cation selected from the group consisting of alkyl-substituted or unsubstituted ammonium cations; alkyl-substituted or unsubstituted piperidinium cations; or alkyl-substituted or unsubstituted pyrrolidinium cations.

10 . The method of claim 1 , wherein the ionic liquid comprises a cation selected from the group consisting of a tetraalkylammonium cation, a dialkylpiperidinium cation, and a dialkylpyrrolidinium cation.

11 . The method of claim 1 , wherein the ionic liquid comprises a cation selected from the group consisting of a butyltrimethylammonium cation; a 1-methyl-1-propylpiperidinium cation, and a 1-methyl-1-propylpyrrolidinium cation.

12 . The method of claim 1 , wherein the applied potential is between −3.2 and −4.0 volts.

13 . The method of claim 1 , wherein the applied potential is pulsed.

14 . The method of claim 1 , wherein the applied potential is constant.

15 . The method of claim 1 , wherein the lithium is deposited as lithium metal, lithium hydride, or lithium hydroxide.

16 . The method of claim 1 , wherein the electrode comprises carbon or gold.

Continuity (2)
Provisional Application 62986032 · Mar 6, 2020
Related Publication 20230072690A1 · Mar 9, 2023
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