Accelerated formation and increased performance in chemically pre-formed (cpf) iron negative electrodes

Patent metadata

Field	Value
Publication number	US-2018261826-A1
Application number	US-201815980088-A
Country	US
Kind code	A1
Filing date	May 15, 2018
Priority date	Sep 5, 2013
Publication date	Sep 13, 2018
Grant date	—

Abstract

Provided is a process for preparing an electrode comprising an iron active material. The process comprises first fabricating an electrode comprising an iron active material, and then treating the surface of the electrode with an oxidant to thereby create an oxidized surface. The resulting iron electrode is preconditioned prior to any charge-discharge cycle to have the assessable surface of the iron active material in the same oxidation state as in discharged iron negative electrodes active material.

First claim

What is claimed is:

1 . A process for preparing an electrode comprising an iron active material, which comprises:
i) fabricating an electrode comprising an iron active material, and ii) treating the surface of the electrode prior to a charge-discharge cycle with an oxidant to thereby create an oxidized surface, and areas of enterparticle contact that are in an oxidized state different from the oxidized iron surface.

2 . The process of claim 1 , wherein the oxidation state of the iron active material in the oxidized surface is +2, +2/+3, +3 or +4.

3 . The process electrode of claim 1 , wherein a binder is added to the electrode during the fabricating of the electrode.

4 . The process of claim 1 , wherein sulfur is added to the electrode during the fabricating of the electrode.

5 . The process of claim 1 , wherein a conductive additive is added to the electrode during the fabricating of the electrode.

6 . The process of claim 5 , wherein the conductive additive comprises nickel, or copper or carbon black.

7 . The process of claim 1 , wherein the fabricating of the electrode comprises mixing an iron active material, nickel powder, a binder and sulfur.

8 . The process of claim 7 , wherein the fabricating of the electrode results in an electrode comprising:
50-90 wt % iron powder 5-30 wt % nickel powder 0.5-5.0 w % binder, and 0.25-20 w % sulfur.

9 . The process of claim 1 , wherein the fabricating of the electrode comprises coating a single layer of the iron active material on at least one side of a conductive substrate.

10 . The process of claim 9 , wherein the substrate is comprised of nickel plated steel.

11 . The process of claim 1 , wherein the porosity of the electrode fabricated in step i) is in the range of about 15-50%.

Assignees

• Encell Technology Inc

Inventors

• Ogg Randy Gene
• Roders Michael
• Meese Michael

Classifications

• H01M4/38

  of elements or alloys · CPC title

• H01M4/26

  Processes of manufacture · CPC title

• H01M4/5815

  Sulfides · CPC title

• H01M4/624

  Electric conductive fillers · CPC title

• H01M4/248

  Iron electrodes · CPC title