Layered iron electrode

Patent metadata

Field	Value
Publication number	US-9368788-B2
Application number	US-201414169405-A
Country	US
Kind code	B2
Filing date	Jan 31, 2014
Priority date	Feb 1, 2013
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

The present invention provides one with a novel coated iron electrode. Provided is an iron based electrode comprising a single layer conductive substrate coated on at least one side with a multilayered coating, with each coating layer comprising an iron active material, and preferably a binder. The coating is comprised of at least two layers. Each layer has at least a different porosity or composition than an adjacent layer. The iron based electrode is useful in alkaline rechargeable batteries, particularly as a negative electrode in a Ni—Fe battery.

First claim

What is claimed is:

1. An iron electrode which comprises a single layer of a conductive substrate coated on at least one side with a coating comprising an iron active material, with the coating comprising at least two layers.

2. The iron electrode of claim 1 , wherein the coating comprises two layers.

3. The iron electrode of claim 2 , wherein the two layers have different porosities.

4. The iron electrode of claim 2 , wherein the two layers have different compositions.

5. The iron electrode of claim 1 , wherein the coating comprises three layers.

6. The iron electrode of claim 5 , wherein at least two of the three layers have different porosities.

7. The iron electrode of claim 5 , wherein at least two of the three layers have different compositions.

8. The iron electrode of claim 1 , wherein each coating layer also comprises a binder.

9. The electrode of claim 8 , wherein the binder comprises polyvinyl alcohol.

10. The iron electrode of claim 1 , wherein at least one of the coating layers comprises a pore former.

11. The electrode of claim 1 , wherein the iron active material comprises an iron metal or iron oxide species.

12. The electrode of claim 1 , wherein at least one coating layer on at least one side comprises a sulfur, antimony, selenium, and tellurium additive, or mixture thereof.

13. The electrode of claim 1 , wherein the layered coating is on both sides of the substrate.

14. The electrode of claim 1 , wherein the substrate is a metal foil, metal sheet, metal foam, metal mesh, woven metal, or expanded metal.

15. The electrode of claim 1 , wherein the porosity of at least one layer of the coating of the electrode is in the range of about 10-50%.

16. The electrode of claim 1 , wherein each layer of coating comprising an iron active material further comprises a polyvinyl alcohol binder and sulfur.

17. A battery comprising a nickel based cathode and the electrode of claim 1 as the anode.

18. A method for preparing the electrode of claim 1 , which comprises preparing at least two coating mixtures of an iron active material, and successively coating at least one side of a substrate with the coating mixtures to create different layers of coating.

19. The method of claim 18 , wherein both sides of the substrate are coated.

20. The method of claim 18 , wherein the coating of both sides of the substrate is continuous.

21. The method of claim 18 , wherein the different layers have different properties.

22. The method of claim 18 , wherein there are three different coating layers coated on the substrate.

23. The method of claim 18 , wherein each layer is of a different density.

24. The method of claim 18 , wherein each coating mixture of an iron active material further comprises a polyvinyl alcohol binder and sulfur.

Assignees

• Encell Technology Inc

Inventors

• Ogg Randy Gene
• Welch Craig Hinton

Classifications

• H01M4/32

  Nickel oxide or hydroxide electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• Y02E60/124

  Cross-Sectional Technologies · mapped topic

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/248 Primary

  Iron electrodes · CPC title