Methods for electrometallizating rare earth elements using anhydrous electrolytes comprising one or more silylamide compounds

Patent metadata

Field	Value
Publication number	US-2026043162-A1
Application number	US-202519292067-A
Country	US
Kind code	A1
Filing date	Aug 6, 2025
Priority date	Aug 6, 2024
Publication date	Feb 12, 2026
Grant date	—

Abstract

A method for electrometallizing one or more rare earth elements includes combining a rare earth element-containing compound comprising one or more rare earth elements with a silylamide-containing anhydrous electrolyte comprising one or more silylamide compounds to form a complex-containing anhydrous electrolyte comprising one or more silylamide-rare earth element complexes. The method also includes applying an electrical potential across electrodes of an electrochemical cell containing the complex-containing anhydrous electrolyte. The electrodes are disposed in the complex-containing anhydrous electrolyte. The method further includes collecting a deposit of at least one rare earth element on at least one electrode. Also disclosed is a system for electrometallizing one or more rare earth elements.

First claim

What is claimed is:

1 . A method for electrometallizing one or more rare earth elements, comprising:
combining a rare earth element-containing compound comprising one or more rare earth elements with a silylamide-containing anhydrous electrolyte comprising one or more silylamide compounds to form a complex-containing anhydrous electrolyte comprising one or more silylamide-rare earth element complexes; applying an electrical potential across electrodes of an electrochemical cell containing the complex-containing anhydrous electrolyte, the electrodes disposed in the complex-containing anhydrous electrolyte; and collecting a deposit of at least one rare earth element on at least one electrode.

2 . The method of claim 1 , wherein the one or more silylamide compounds has the following chemical formula:

wherein:
A comprises at least one of lithium, sodium, potassium, or calcium;
R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 each independently comprises hydrogen, an alkyl group, or a combination thereof; and
X is 1 or 2.

3 . The method of claim 2 , wherein A comprises lithium, calcium, or a combination thereof.

4 . The method of claim 2 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are a methyl group.

5 . The method of claim 2 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 is an alkyl group comprising from one carbon atom to six carbon atoms.

6 . The method of claim 1 , wherein the one or more silylamide compounds comprise lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, calcium bis(trimethylsilyl)amide, or a combination thereof.

7 . The method of claim 1 , wherein the rare earth element comprises lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, or a combination thereof.

8 . The method of claim 1 , wherein applying the electrical potential across the electrodes of the electrochemical cell comprises applying the electrical potential at a temperature of from about 20° C. to about 25° C.

9 . The method of claim 1 , wherein applying the electrical potential across the electrodes of the electrochemical cell comprises applying the electrical potential across at least two electrodes maintained under an inert atmosphere.

10 . The method of claim 1 , wherein applying an electrical potential across electrodes of an electrochemical cell comprises reducing the one or more silylamide-rare earth element complexes to deposit the one or more rare earth elements on the at least one electrode.

11 . A method for electrometallizing at least one rare earth element, comprising:
combining a rare earth element-containing compound comprising at least one rare earth element with a silylamide-containing anhydrous electrolyte comprising at least one silylamide compound to form a complex-containing anhydrous electrolyte comprising at least one silylamide-rare earth element complex; providing an electrochemical cell comprising the complex-containing anhydrous electrolyte, at least one cathode disposed in the complex-containing anhydrous electrolyte, and at least one anode disposed in the complex-containing anhydrous electrolyte; applying an electrical potential across the at least one cathode and the at least one anode of the electrochemical cell; collecting a deposit comprising the at least one rare earth element on the at least one cathode of the electrochemical cell; and recovering the at least one rare earth element from the collected deposit, wherein the at least one silylamide compound has the following chemical formula:

wherein:
A comprises at least one of lithium, sodium, potassium, or calcium;
R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 each independently comprises hydrogen, a C1-C6 alkyl group, or a combination thereof; and
X is 1 or 2.

12 . The method of claim 11 , wherein the rare earth element-containing compound comprises a rare earth salt, a rare earth oxide, a rare earth nitrate, a rare earth chloride, a rare earth trifluoromethanesulfanone, a rare earth carbonate, a rare earth bistriflimide, or a combination thereof.

13 . The method of claim 11 , wherein the rare earth element comprises neodymium, dysprosium, or a combination thereof.

14 . The method of claim 11 , wherein the at least one silylamide compound comprises lithium bis(trimethylsilyl)amide, calcium bis(trimethylsilyl)amide, or a combination thereof.

15 . The method of claim 11 , wherein the at least one silylamide compound is substantially free of one or more of fluorine, oxygen, sulfur, or boron atoms.

16 . A system for electrometallizing one or more rare earth elements, the system comprising:
a container configured to contain a complex-containing anhydrous electrolyte therein, the complex-containing anhydrous electrolyte comprising at least one silylamide-rare earth element complex; an electrodeposition reservoir configured to receive an amount of the complex-containing anhydrous electrolyte from the container, the electrodeposition reservoir including:
a reservoir inlet configured to facilitate an addition of the complex-containing anhydrous electrolyte into the electrodeposition reservoir; and
a reservoir outlet configured to facilitate a removal of a spent complex-containing anhydrous electrolyte from the electrodeposition reservoir, the spent complex-containing anhydrous electrolyte exhibiting a lower amount of the at least one silylamide-rare earth element complex compared to the complex-containing anhydrous electrolyte;
at least one counter-electrode and at least one working electrode disposed below a surface of the complex-containing anhydrous electrolyte in the electrodeposition reservoir,
the at least one counter-electrode configured to release electrons to the complex-containing anhydrous electrolyte upon an application of an electrical potential across the at least one counter-electrode and at least one working electrode, and
the at least one working electrode configured to receive a deposit of the at least one rare earth element from a reduction of the complex-containing anhydrous electrolyte upon the application of the electrical potential across the at least one counter-electrode and the at least one working electrode; and
a potential source configurated to apply the electrical potential across the at least one counter-electrode and the at least one working electrode.

17 . The system of claim 16 , wherein the system is configured to operate in a batch mode, a semi-batch mode, or a continuous mode.

18 . The system of claim 16 , wherein the potential source is configured to apply the electrical potential of from about +1.0V to about −4.0V across the at least one counter-electrode and at least one working electrode.

19 . The system of claim 16 , wherein the potential source is configured to generate a current density of from about 0.5 mA/cm 2 to about 5 mA/cm 2 between the at least one counter-electrode and the at least one working electrode, and through the complex-containing anhydrous electrolyte.

20 . The system of claim 16 , further comprising a controlled environment enclosure dimensioned and configured to conta

Assignees

• Battelle Energy Alliance Llc

Inventors

• Atifi Abderrahman
• Klaehn John R

Classifications

• C25C3/34

  of metals not provided for in groups C25C3/02 - C25C3/32 · CPC title

• C25D3/54

  of metals not provided for in groups C25D3/04 - C25D3/50 · CPC title

• C25C7/08

  Separating of deposited metals from the cathode · CPC title

• C25C1/22 Primary

  of metals not provided for in groups C25C1/02 - C25C1/20 · CPC title