Iron electrode employing a polyvinyl alcohol binder

Patent metadata

Field	Value
Publication number	US-2018006296-A1
Application number	US-201615256886-A
Country	US
Kind code	A1
Filing date	Sep 6, 2016
Priority date	Feb 1, 2013
Publication date	Jan 4, 2018
Grant date	—

Abstract

The present invention provides one with an iron electrode employing a binder comprised of polyvinyl alcohol (PVA) binder. In one embodiment, the invention comprises an iron based electrode comprising a single layer of a conductive substrate coated on at least one side with a coating comprising an iron active material and a binder, wherein the binder is PVA. This iron based electrode is useful in alkaline rechargeable batteries, particularly as a negative electrode in a Ni—Fe battery.

First claim

1 . A method of preparing an iron electrode comprising the steps of
i) preparing a paste formulation which comprises an iron active material, sulfur and from 2 to 5 wt % of a polyvinyl alcohol binder; ii) providing a single layer substrate; and iii) coating the paste formulation on at least one side of the single layer substrate.

2 . The method of claim 1 , wherein the paste formulation further comprises a pore former, carbon, graphite or Ni powder.

3 . The method of claim 1 , wherein the single layer substrate comprises a thin conductive material.

4 . The method of claim 3 , wherein the thin conductive material comprises a perforated metal foil or sheet, metal mesh or screen, woven metal, or expanded metal.

5 . The method of claim 4 , wherein the thin conductive material comprises a nickel plated perforated foil.

6 . The method of claim 1 , wherein the single layer substrate comprises a three dimensional material.

7 . The method of claim 6 , wherein the three dimensional material comprises a metal foam or metal felt.

8 . The method of claim 1 , wherein the sulfur is present in the paste formulation in the amount of from 0.25 to 1.5% by weight.

9 . The method of claim 1 , wherein the paste formulation is coated on both sides of the substrate.

10 . The method of claim 1 , wherein the sulfur comprises elemental sulfur.

11 . The method of claim 1 , wherein the active iron material comprises iron metal, an iron oxide material, or a mixture thereof.

12 . The method of claim 11 , wherein the iron oxide material comprises Fe 3 O 4 .

13 . The method of claim 1 , wherein the polyvinyl alcohol binder comprises polyvinyl alcohol that is hydrolyzed between 98.5 and 100%.

14 . The method of claim 1 , wherein the polyvinyl alcohol binder comprises polyvinyl alcohol that is hydrolyzed between 99 and 100%.

15 . The method of claim 1 , wherein the polyvinyl alcohol binder comprises from 2.5 to 4 wt % of the iron electrode.

Assignees

• Encell Technology Inc

Inventors

• Ogg Randy Gene
• Welch Craig
• Seidel Alan

Classifications

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/622

  being polymers · CPC title

• H01M4/26

  Processes of manufacture · CPC title

• C09D129/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• H01M4/38

  of elements or alloys · CPC title