Negative electrolyte management system

Patent metadata

Field	Value
Publication number	US-2024055642-A1
Application number	US-202318358874-A
Country	US
Kind code	A1
Filing date	Jul 25, 2023
Priority date	Aug 9, 2022
Publication date	Feb 15, 2024
Grant date	—

Abstract

Systems and methods are provided for managing health of electrolytes of redox flow battery system. Components of the system may include a redox rebalancing cells and a gas storage system. The redox rebalancing cell may be operated by plating iron on a plating electrode, treating a negative electrolyte of the redox flow battery system with the plated iron and returning the negative electrolyte to an electrolyte tank. The gas storage system may include a set of expandable gas storage tanks coupled to at least one electrolyte storage tank and an electrolyte rebalancing system of the redox flow battery system.

First claim

1 . A method for a redox rebalancing cell of a redox flow battery, comprising:
plating iron on a plating electrode of the redox rebalancing cell; treating a negative electrolyte of the redox flow battery by reducing Fe 3+ to Fe 2+ with the plated iron; and returning the negative electrolyte to an electrolyte tank.

2 . The method of claim 1 , wherein plating iron includes operating the redox flow battery in a charging mode and the plating electrode is a negative electrode of the redox flow battery.

3 . The method of claim 1 , wherein plating iron includes flowing positive electrolyte to the redox rebalancing cell and applying a potential across the redox rebalancing cell.

4 . The method of claim 3 , wherein flowing the positive electrolyte to the redox rebalancing cell occurs during operation of the redox flow battery is in a substantially discharged state.

5 . The method of claim 3 , wherein treating the negative electrolyte includes flowing the negative electrolyte to the redox rebalancing cell after the positive electrolyte is completely drained from the redox rebalancing cell.

6 . The method of claim 1 , where treating the negative electrolyte includes applying a voltage to drive the reducing of Fe 3+ to Fe 2+ with the plated iron to increase a rate of the reducing of Fe 3+ to Fe 2+ .

7 . An electrolyte management system for a redox flow battery cell, comprising:
a battery cell with a positive electrode compartment and a negative electrode compartment; a redox rebalancing cell arranged between the redox flow battery cell and an electrolyte storage tank, the redox rebalancing cell including an electrode electrically shorted to a negative electrode of the battery cell; and a negative electrolyte circulated through the negative electrode compartment, the redox rebalancing cell, and the electrolyte storage tank.

8 . The electrolyte management system of claim 7 , wherein the electrode of the redox rebalancing cell is formed from a large surface area material.

9 . The electrolyte management system of claim 7 , wherein the electrode of the redox rebalancing cell is formed of activated carbon.

10 . The electrolyte management system of claim 7 , wherein the electrode of the redox rebalancing cell is electrically shorted to the negative electrode by a wire electrically coupling the electrode of the redox rebalancing cell to the negative electrode, and wherein a reverse voltage potential is applied to the wire by a power supply and configured to increase a rate of reaction at the redox rebalancing cell.

11 . The electrolyte management system of claim 7 , wherein the redox rebalancing cell is positioned proximate to the negative electrode of the redox flow battery cell to reduce ionic and electrical resistance between the negative electrode and the redox rebalancing cell.

12 . The electrolyte management system of claim 7 , wherein the redox flow battery cell is one of an electrode stack and the negative electrode of the redox flow battery cell is a negative endplate electrode.

13 . The electrolyte management system of claim 7 , wherein the negative electrode is configured to plate Fe 0 and the Fe 0 is configured to reduce Fe 3+ to Fe 2+ in the negative electrolyte in the redox rebalancing cell.

14 . An electrolyte management system for a redox flow battery cell, comprising:
a battery cell with a positive electrode compartment and a negative electrode compartment; a redox rebalancing cell arranged between the redox flow battery cell and an electrolyte storage tank, the redox rebalancing cell including; a plating electrode, a positive electrode, and a separator positioned between the plating electrode and positive electrode; and a conductor coupled to a power source configured to apply a first voltage and a second voltage between the plating electrode and the positive electrode.

15 . The electrolyte management system of claim 14 , wherein the plating electrode of the redox rebalancing cell is a porous and conductive material configured to plate a layer of iron.

16 . The electrolyte management system of claim 14 , wherein the separator is ion conductive and electrically insulating.

17 . The electrolyte management system of claim 14 , wherein the redox rebalancing cell is configured to receive an electrolyte from the positive electrode compartment or the negative electrode compartment, and the electrolyte received by the redox rebalancing cell contacts both the plating electrode and the positive electrode.

18 . The electrolyte management system of claim 14 , further comprising a controller including executable instructions stored in non-transitory memory thereon to:
circulate positive electrolyte through the positive electrode compartment, redox rebalancing cell, and electrolyte tank when the redox flow battery cell is substantially discharged; empty the redox rebalancing cell of positive electrolyte; circulate negative electrolyte through the negative electrode compartment, redox rebalancing cell, and electrolyte tank.

19 . The electrolyte management system of claim 18 , wherein the executable instructions further include to:
apply the first voltage between the positive electrode and the plating electrode to drive reduction of Fe 2+ to Fe 0 at the plating electrode while positive electrolyte is circulated.

20 . The electrolyte management system of claim 19 , wherein the executable instructions further include to:
apply the second voltage between the positive electrode and the plating electrode to increase a rate of reduction of Fe 3+ by Fe 0 at the plating electrode while negative electrolyte is circulated, wherein the second voltage is opposite polarity of the first voltage.

Assignees

• Ess Technology Inc

Inventors

• Kissick Sean
• Mcdonald Timothy J
• Song Yang

Classifications

• H01M8/188 Primary

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

• H01M8/04276

  Arrangements for managing the electrolyte stream, e.g. heat exchange · CPC title

• H01M4/96

  Carbon-based electrodes · CPC title

• H01M8/04746

  Pressure; Flow · CPC title

• H01M8/04865 Primary

  Voltage · CPC title