System and method of selective electrodeposition for metal recycling

Patent metadata

Field	Value
Publication number	US-2024426013-A1
Application number	US-202218698241-A
Country	US
Kind code	A1
Filing date	Oct 4, 2022
Priority date	Oct 7, 2021
Publication date	Dec 26, 2024
Grant date	—

Abstract

A system for selective electrodeposition for metal recycling includes an electrochemical cell comprising: a fluid including first and second transition metals and a salt at a molar concentration of greater than 1 M; a working electrode in contact with the fluid. where the working electrode has a surface coated with a positively charged polyelectrolyte: and a counter electrode in contact with the fluid and spaced apart from the working electrode. The system also includes a power supply electrically connected to the working and counter electrodes.

First claim

1 . A method of selective electrodeposition for metal recycling, the method comprising:
introducing a working fluid including first and second metal species into an electrochemical cell including: a working electrode having a surface coated with a positively charged polyelectrolyte; and a counter electrode spaced apart from the working electrode; adding a concentrated salt to the working fluid, the concentrated salt having a molar concentration in the working fluid of greater than 1 M, whereby oppositely charged complexes comprising the first and second metal species are formed; selecting one of the first and second metal species to be a targeted metal species for selective electrodeposition, the other of the first and second metal species being a non-targeted metal species; applying a cathodic potential that is more negative than a reduction potential of at least one of the first and second metal species to the working electrode; and selectively electrodepositing the targeted metal species on the working electrode, thereby producing an electrodeposit having an atomic ratio of the targeted metal species to the non-targeted metal species higher than that in the working fluid introduced into the electrochemical cell.

2 . The method of claim 1 , wherein the electrodeposit has a targeted metal purity of at least about 75%.

3 . The method of claim 1 , wherein the cathodic potential is more negative than the reduction potentials of both the first and second metal species.

4 . The method of claim 1 , wherein the cathodic potential is between the reduction potentials of the first and second metal species.

5 - 6 . (canceled)

7 . The method of claim 1 , wherein the positively charged polyelectrolyte is coated on the surface at a loading level of greater than zero and up to about 100 mg/m 3 .

8 - 10 . (canceled)

11 . The method of claim 1 , wherein the molar concentration of the concentrated salt is greater than 10 M.

12 . The method of claim 1 , wherein the concentrated salt comprises or takes the form of a halogenated salt, an ionic liquid, and/or a deep eutectic solvent.

13 . (canceled)

14 . The method of claim 1 , wherein, prior to the addition of the concentration salt, a reduction potential of the first metal species is within about 2% of a reduction potential of the second metal species.

15 . The method of claim 1 , wherein, after the addition of the concentrated salt, the reduction potentials of the first and second metal species differ by at least about 10%.

16 . The method of claim 1 , wherein each of the first metal species and the second metal species comprises a transition metal selected from the group consisting of: Ag, Au, Cd, Co, Cu, Cr, Fe, Hf, Hg, Ir, Lu, Mn, Mo, Nb, Ni, Os, Pd, Pt, Re, Rh, Ru, Sc, Ta, Tc, Ti, W, Y, Zn, and Zr.

17 - 19 . (canceled)

20 . The method of claim 1 , wherein the first metal species comprises cobalt ions and the second metal species comprises nickel ions.
wherein the second metal species is selected to be the targeted metal species, the first metal species being the non-targeted metal species, wherein the cathodic potential is between about −0.55 V and −0.60 V, and wherein the positively charged polyelectrolyte is coated on the surface at a loading level of at least 1 mg cm −2 .

21 . The method of claim 1 , wherein the first metal species comprises cobalt ions and the second metal species comprises nickel ions,
wherein the first metal species is selected to be the targeted metal species, the second metal species being the non-targeted metal species, wherein the cathodic potential is between about −0.65 V and −0.88 V, and wherein the positively charged polyelectrolyte is coated on the surface at a loading level of less than 1 mg cm −2 .

22 . The method of claim 1 , further comprising, after the selective electrodeposition, conducting a stripping or regeneration process whereby the first metal ions and the second metal ions are removed from the working electrode and captured in a stripping solution comprising an acid.

23 - 25 . (canceled)

26 . The method of claim 1 , wherein, after the selective electrodeposition, the working fluid is a depleted working fluid having a higher atomic ratio of the non-targeted metal species to the targeted metal species in comparison with the working fluid introduced into the electrochemical cell.

27 . The method of claim 26 , further comprising, after the selective electrodeposition, introducing the depleted working fluid into a second electrochemical cell for selective electrodeposition of the non-targeted metal species, the second electrochemical cell including: a second working electrode having a surface coated with a positively charged polyelectrolyte; and a second counter electrode spaced apart from the second working electrode; and
applying a cathodic potential that is more negative than a reduction potential of the non-targeted metal species to the second working electrode; and selectively electrodepositing the non-targeted metal species on the second working electrode, thereby producing a second electrodeposit having an atomic ratio of the non-targeted metal species to the targeted metal species higher than that of the depleted working fluid introduced into the second electrochemical cell.

28 - 30 . (canceled)

31 . The method of claim 1 , wherein the working fluid comprises a waste fluid derived from industrial manufacturing, spent batteries, and/or mining operations.

32 - 24 . (canceled)

35 . A system for selective electrodeposition for metal recycling, the system comprising:
an electrochemical cell including:
a fluid including first and second transition metals and a salt at a molar concentration of greater than 1 M;
a working electrode in contact with the fluid, the working electrode having a surface coated with a positively charged polyelectrolyte; and
a counter electrode in contact with the fluid and spaced apart from the working electrode; and
a power supply electrically connected to the working and counter electrodes.

36 - 38 . (canceled)

39 . The system of claim 35 , wherein the positively charged polyelectrolyte is selected from the group consisting of:
poly(diallyldimethylammonium chloride) (PDADMA), poly(vinylbenzyltrimethylammonium chloride (PVBTMAC), poly (acryloyloxyethyltrimethylammonium) (PAOEt), poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA), poly(4-N-methylvinylpyridinium chloride) (PVMPB), and poly(allylamine hydrochloride (PAH).

40 . The system of claim 35 , wherein the molar concentration of the concentrated salt is greater than 10 M.

41 . The system of claim 35 , wherein the concentrated salt comprises or takes the form of a halogenated salt, an ionic liquid, and/or a deep eutectic solvent.

42 . (canceled)

Assignees

• Univ Illinois

Inventors

• Su Xiao
• Kim Kwiyong

Classifications

• C25D3/12

  of nickel or cobalt · CPC title

• C25C7/08

  Separating of deposited metals from the cathode · CPC title

• C25C1/08 Primary

  of nickel or cobalt · CPC title

• Y02P10/20

  Recycling · CPC title

• C25C1/20

  of noble metals · CPC title