High-energy-density, aqueous, metal-polyiodide redox flow batteries

Patent metadata

Field	Value
Publication number	US-9748595-B2
Application number	US-201314089499-A
Country	US
Kind code	B2
Filing date	Nov 25, 2013
Priority date	Nov 25, 2013
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

Improved metal-based redox flow batteries (RFBs) can utilize a metal and a divalent cation of the metal (M 2+ ) as an active redox couple for a first electrode and electrolyte, respectively, in a first half-cell. For example, the metal can be Zn. The RFBs can also utilize a second electrolyte having I − , anions of I x (for x≧3), or both in an aqueous solution, wherein the I − and the anions of I x (for x≧3) compose an active redox couple in a second half-cell.

First claim

We claim:

1. A redox flow battery (RFB) comprising:
a first electrolyte comprising Zn 2+ in an aqueous solution and a first electrode comprising Zn, wherein the Zn and the Zn 2+ compose a first active redox couple at a first half-cell;
a second electrolyte comprising I − , anions of I x (x≧3), or both in the aqueous solution, wherein the I − and the anions of I x compose a second active redox couple at a second half-cell; and
a membrane or separator between the first and second half-cells;
wherein the RFB has an energy density (based on the positive electrolyte) greater than 60 Wh/L and the aqueous solution contains substantially no I 2 .

2. The RFB of claim 1 , wherein the aqueous solution has a pH greater than 3.

3. The RFB of claim 1 , wherein the first electrode comprises the Zn on a porous, conductive material.

4. The RFB of claim 3 , wherein the porous conductive material comprises conductive carbon, graphite fibers, graphene, or a metallic material.

5. The RFB of claim 1 , wherein the first electrode comprises M on a dense solid conductive material.

6. The RFB of claim 1 , wherein the membrane comprises an ion-exchange membrane, or a solid-state membrane.

7. The RFB of claim 1 , wherein the anions of I x comprise I 3 − .

8. The RFB of claim 1 , wherein the anions of I x comprise I 4 − .

9. The RFB of claim 1 , wherein the anions of I x comprise I 6 − .

10. The RFB of claim 1 , wherein the anions of I x comprise I − 2n+p , wherein n and p are positive integers and 1≦p≦4.

11. The RFB of claim 1 , wherein the separator comprises a microporous separator.

Assignees

• Battelle Memorial Institute

Inventors

• Li Bin
• Nie Zimin
• Wang Wei
• Liu Jun
• Sprenkle Vincent L

Classifications

• Y02E60/528

  Cross-Sectional Technologies · mapped topic

• H01M8/188 Primary

  by recharging of redox couples containing fluids; Redox flow type batteries · CPC title

• H01M8/20

  Indirect fuel cells, e.g. fuel cells with redox couple being irreversible (H01M8/18 takes precedence) · CPC title

• Y02E60/50

  Fuel cells · CPC title