Method and system for rebalancing electrolytes in a redox flow battery system

Patent metadata

Field	Value
Publication number	US-2016293992-A1
Application number	US-201615182543-A
Country	US
Kind code	A1
Filing date	Jun 14, 2016
Priority date	Jun 7, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

A method of rebalancing electrolytes in a redox flow battery system comprises directing hydrogen gas generated on the negative side of the redox flow battery system to a catalyst surface, and fluidly contacting the hydrogen gas with an electrolyte comprising a metal ion at the catalyst surface, wherein the metal ion is chemically reduced by the hydrogen gas at the catalyst surface, and a state of charge of the electrolyte and pH of the electrolyte remain substantially balanced.

First claim

1 . A redox flow battery system, comprising:
a redox flow battery cell, and a catalyst bed fluidly connected to the battery cell, wherein
the catalyst bed includes a substrate layer and a catalyst layer coated on the substrate layer spiral wound into a jelly roll structure.

2 . The redox flow battery system of claim 1 , wherein the catalyst bed further includes a spacing layer positioned on the catalyst layer spiral wound into the jelly roll structure, wherein the spacing layer separates successive catalyst and substrate layers within the jelly roll structure.

3 . The redox flow battery system of claim 2 , wherein the catalyst layer comprises one or more of Pt, Pd, Ru or alloys thereof.

4 . The redox flow battery system of claim 2 , wherein the substrate layer comprises carbon paper or carbon cloth.

5 . The redox flow battery system of claim 2 , wherein the substrate layer comprises a membrane.

6 . The redox flow battery system of claim 2 , wherein the spacing layer comprises a plastic mesh.

7 . The redox flow battery system of claim 2 , further comprising a fluid recirculation device positioned between the redox flow battery cell and the catalyst bed, wherein the fluid recirculation device directs hydrogen gas from the battery cell to the catalyst bed, and the hydrogen gas is oxidized at the catalyst bed to form hydrogen ions.

8 . The redox flow battery system of claim 7 , wherein the fluid recirculation device directs electrolyte including metal ions from the redox flow battery cell to the catalyst bed, and the metal ions are reduced at the catalyst bed.

9 . The redox flow battery system of claim 8 , wherein the fluid recirculation device directs the hydrogen ions and the reduced metal ions from the catalyst bed to the redox flow battery cell.

10 . The redox flow battery system of claim 9 , wherein the redox battery cell further comprises an electrolyte source, wherein the fluid recirculation device directs the hydrogen ions and the reduced metal ions from the catalyst bed to the electrolyte source before directing hydrogen ions and the reduced metal ions from the catalyst bed to the redox flow battery cell.

11 . A method of rebalancing electrolytes in a redox flow battery system, comprising:
directing hydrogen gas from a redox flow battery cell to a catalyst bed, oxidizing the hydrogen gas at the catalyst bed to form hydrogen ions, and recirculating the hydrogen ions from the catalyst bed to the redox flow battery cell.

12 . The method of claim 11 , further comprising coating a substrate layer with a catalyst layer, and spiral winding the substrate layer and the catalyst layer into a jellyroll structure to form the catalyst bed.

13 . The method of claim 12 , further comprising positioning a spacing layer on the catalyst layer and spiral winding the spacing layer with the substrate layer and the catalyst layer into the jellyroll structure to form the catalyst bed.

14 . The method of claim 13 , wherein directing hydrogen gas from the redox flow battery cell to the catalyst bed comprises directing hydrogen gas axially into the jellyroll structure of the catalyst bed.

15 . The method of claim 14 , wherein directing hydrogen gas from the redox flow battery cell to the catalyst bed comprises directing hydrogen gas radially through the spiral wound substrate and catalyst layers of the jellyroll structure.

16 . The method of claim 15 , further comprising directing electrolyte comprising metal ions from the redox flow battery to the catalyst bed, oxidizing the hydrogen gas to form hydrogen ions and reducing the metal ions at the catalyst bed.

17 . The method of claim 16 , further comprising recirculating the hydrogen ions and the reduced metal ions from the catalyst bed to the redox flow battery cell.

18 . A redox flow battery system, comprising:
a redox flow battery cell, an electrolyte source supplying metal ions to the redox flow battery cell, a catalyst bed, including a catalyst layer coated on a substrate layer spiral wound into a jelly roll structure, a recirculation device fluidly connected between the redox flow battery cell and the catalyst bed, and a controller, including executable instructions stored in memory to,
operate the recirculation device to direct hydrogen gas and metal ions from the redox flow battery cell to the catalyst bed.

19 . The redox flow battery system of claim 18 , wherein
the hydrogen gas is oxidized at the catalyst layer to hydrogen ions and the metal ions are reduced at the catalyst layer, and the executable instructions further comprise operating the recirculation device to direct the hydrogen ions and the reduced metal ions from the catalyst layer to the electrolyte source.

20 . The redox flow battery system of claim 19 , further comprising a hydrogen gas source external to the redox flow battery cell, wherein the executable instructions further comprise directing hydrogen gas from the hydrogen gas source to the catalyst bed.

Assignees

• Ess Technology Inc

Inventors

• Song Yang
• Evans Craig E

Classifications

• H01M8/004

  Cylindrical, tubular or wound · CPC title

• H01M8/20

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

• H01M8/188 Primary

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

• H01M8/0693

  Treatment of the electrolyte residue, e.g. reconcentrating · CPC title

• Y02E60/50

  Fuel cells · CPC title