Electrolyte health management for redox flow battery

Patent metadata

Field	Value
Publication number	US-2023378505-A1
Application number	US-202318361626-A
Country	US
Kind code	A1
Filing date	Jul 28, 2023
Priority date	Nov 20, 2018
Publication date	Nov 23, 2023
Grant date	—

Abstract

Methods and systems are provided for a rebalancing reactor of a flow battery system. In one example, a pH of a battery electrolyte may be maintained by the rebalancing reactor by applying a negative potential to a catalyst bed of the rebalancing reactor. A performance of the rebalancing reactor may further be maintained by treating the catalyst bed with deionized water.

First claim

1 . A redox flow battery system, comprising:
a cell receiving electrolyte and hydrogen gas; a rebalancing reactor fluidly coupled to the cell and configured to also receive the electrolyte and the hydrogen gas; and a conductive wire embedded in a catalyst bed of the rebalancing reactor, the conductive wire configured to apply a negative potential to the catalyst bed to impede formation of a double diffusion layer and increase a ferrous iron reduction rate at the catalyst bed.

2 . The redox flow battery system of claim 1 , wherein the catalyst bed is formed of a substrate layer coated with at least one catalyst layer and a spacing layer arranged over the at least one catalyst layer and wherein the catalyst bed is coiled into a cylindrical shape.

3 . The redox flow battery system of claim 2 , wherein the conductive wire is woven in the catalyst layer along a plane of the catalyst layer and wherein the conductive wire is connected to an electrical storage device enabling generation of the negative potential.

4 . The redox flow battery system of claim 1 , wherein ends of the conductive wire extend out of the catalyst bed, the catalyst bed comprising a jelly roll structure.

5 . The redox flow battery system of claim 4 , wherein the conductive wire is coupled to a battery.

6 . The redox flow battery system of claim 1 , further comprising a controller with computer-readable instructions stored on non-transitory that when executed enable the controller to supply a voltage to the conductive wire in response to the ferric iron reduction rate decreasing below a threshold rate.

7 . A system for a redox flow battery, comprising:
a rebalancing cell configured to receive electrolyte and hydrogen; a catalyst bed arranged in the rebalancing cell; a conductive wire coupled to the catalyst bed and to a battery external to the rebalancing cell; and a controller with computer-readable instructions stored on non-transitory that when executed enable the controller to supply a voltage to the conductive wire in response to a ferric iron reduction rate decreasing below a threshold rate.

8 . The system of claim 7 , wherein the instructions further enable the controller to flow deionized water to the rebalancing cell in response to the ferric iron reduction rate decreasing below the threshold rate.

9 . The system of claim 7 , wherein the instructions further enable the controller to soak the catalyst bed in deionized water following a threshold interval of operating the rebalancing cell.

10 . The system of claim 7 , wherein the catalyst bed further comprises an anode embedded therein, wherein the anode is separate from a cathode via a membrane separator.

11 . The system of claim 7 , wherein the conductive wire is woven into a spacing layer of the catalyst bed.

12 . The system of claim 7 , wherein the conductive wire is arranged between a spacing layer and a catalyst layer of the catalyst bed.

13 . The system of claim 7 , wherein the instructions further comprise soaking the catalyst bed with deionized water based on a ratio greater than a threshold ratio, the threshold ratio based on a comparison of a deionized water volume to a catalyst surface area.

14 . The system of claim 13 , wherein the ratio is greater than 10,000 mL/m 2 .

15 . The system of claim 13 , wherein the ratio is greater than or equal to 20,000 mL/m 2 .

16 . A method, comprising:
activating a conductive wire coupled to a catalyst bed in response to a ferric iron reduction rate decreasing below a threshold rate, wherein the catalyst bed is arranged in a cell balancing reactor of a redox flow battery system.

17 . The method of claim 16 , wherein activating the conductive wire comprises supplying a voltage from a battery to the conductive wire.

18 . The method of claim 16 , further comprising soaking the catalyst bed with a threshold volume of deionized water, the threshold volume proportional to an area of the catalyst bed.

19 . The method of claim 16 , wherein the catalyst bed further comprises a hydrogen oxidation catalyst embedded therein.

20 . The method of claim 16 , further comprising flowing deionized water to the catalyst bad and blocking the flow of hydrogen and electrolyte to the cell balancing reactor following a threshold interval.

Assignees

• Ess Technology Inc

Inventors

• Song Yang
• Mcdonald Timothy J
• Behr Alexandria

Classifications

• H01M8/0693 Primary

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

• H01M8/188 Primary

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

• H01M8/0444

  Concentration; Density (H01M8/04492 takes precedence) · CPC title

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M8/04186

  of liquid-charged or electrolyte-charged reactants · CPC title