Flow battery with voltage-limiting device

Patent metadata

Field	Value
Publication number	US-9966618-B2
Application number	US-201214650126-A
Country	US
Kind code	B2
Filing date	Dec 9, 2012
Priority date	Dec 9, 2012
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A flow battery includes at least one cell that has a first electrode, a second electrode spaced apart from the first electrode and an electrolyte separator layer that is arranged between the first electrode and the second electrode. A storage portion is fluidly connected with the at least one cell. At least one liquid electrolyte includes an electrochemically active specie and is selectively deliverable to the at least one cell. An electric circuit is coupled with the first electrode and the second electrode. The circuit includes a voltage-limiting device that is configured to limit a voltage potential across the first electrode and the second electrode in response to a transition of the at least one cell from an inactive, shut-down mode with respect to an active, charge/discharge mode.

First claim

What is claimed is:

1. A flow battery comprising:
at least one cell including a first electrode, a second electrode spaced apart from the first electrode, and an electrolyte separator layer arranged between the first electrode and the second electrode;
a storage portion fluidly connected with the at least one cell;
at least one liquid electrolyte including an electrochemically active specie, the at least one liquid electrolyte being selectively deliverable to the at least one cell;
an electric circuit electrically coupled with the first electrode and the second electrode and capable of transmitting electrical energy to and from the at least one cell during an active, charge/discharge mode, the electric circuit including a voltage-limiting device configured to limit a voltage potential across the first electrode and the second electrode in response to a transition of the at least one cell to or from the inactive, shut-down mode with respect to an active, charge/discharge mode, wherein the voltage-limiting device has a plurality of resistors; and
a controller in communication with the voltage-limiting device, the controller being configured to individually control operation of each of the resistors between ON/OFF conditions to control an amount of electric impedance, and wherein the controller is configured to increase the impedance during transition of the at least one cell from the inactive, shut-down mode to the active, charge/discharge mode and decrease impedance during transition from the active, charge/discharge mode to the inactive, shut-down mode.

2. The flow battery as recited in claim 1 , wherein, in the inactive, shut-down mode, there is no active flow of the at least one liquid electrolyte from the storage portion to the at least one cell.

3. The flow battery as recited in claim 2 , wherein, in the inactive, shut-down mode, the at least one cell is at least partially empty of the at least one liquid electrolyte.

4. The flow battery as recited in claim 2 , wherein, in the inactive, shut-down mode, the at least one cell includes a cover gas selected from the group consisting of air, nitrogen, argon, helium, hydrogen and combinations thereof.

5. The flow battery as recited in claim 2 , wherein, in the inactive, shut-down mode, the at least one cell includes the at least one liquid electrolyte in a discharged state.

6. A method of controlling a voltage potential in a flow battery during a mode transition to control corrosion, the method comprising:
(a) transitioning a flow battery to or from an inactive, shut-down mode with respect to an active, charge/discharge mode, the flow battery including at least one cell having a first electrode, a second electrode spaced apart from the first electrode, and an electrolyte separator layer arranged between the first electrode and the second electrode; and
(b) limiting a voltage potential across the first electrode and the second electrode of the flow battery during step (a) using a voltage-limiting device arranged in an electric circuit that is electrically coupled with the first electrode and the second electrode, the electric circuit capable of transmitting electrical energy to and from the at least one cell during the active, charge/discharge mode, wherein the voltage-limiting device has a plurality of resistors, and the limiting of the voltage potential includes individually controlling operation of each of the resistors between ON/OFF conditions to control an amount of electric impedance by increasing impedance during transition from the inactive, shut-down mode to the active, charge/discharge mode and decreasing the impedance during transition from the active, charge/discharge mode to the inactive, shut-down mode.

7. The method as recited in claim 6 , including limiting the voltage potential across the first electrode and the second electrode to be below a predefined threshold voltage potential.

8. The method as recited in claim 6 , wherein, in the inactive, shut-down mode, there is no active flow of at least one liquid electrolyte of the flow battery from a storage portion of the flow battery to the at least one cell.

9. The method as recited in claim 8 , wherein the transitioning includes starting the flow battery from the inactive, shut-down mode to the active, charge/discharge mode, and during the starting of the flow battery, the at least one cell of the flow battery is partially empty of at least one liquid electrolyte.

10. The method as recited in claim 8 , wherein the transitioning includes starting the flow battery from the inactive, shut-down mode to the active, charge/discharge mode, and during the starting of the flow battery, the at least one cell includes a cover gas therein that is select from the group consisting of air, nitrogen, argon, helium, hydrogen and combinations thereof.

11. The method as recited in claim 6 , wherein the transitioning includes starting the flow battery from the inactive, shut-down mode to the active, charge/discharge mode, and during the starting of the flow battery, feeding a positive liquid electrolyte and a negative liquid electrolyte to, respectively, the first electrode and the second electrode such that the positive liquid electrolyte and the negative liquid electrolyte are fed one at a time.

12. The method as recited in claim 6 , wherein the transitioning includes starting the flow battery from the inactive, shut-down mode to the active, charge/discharge mode, and disengaging the voltage-limiting device such that the voltage-limiting device ceases to limit the voltage potential across the first electrode and the second electrode.

13. The method as recited in claim 6 , wherein the transitioning includes stopping the flow battery from the active, charge/discharge mode into the inactive, shut-down mode, and during the stopping, stopping active flow of a positive liquid electrolyte and a negative liquid electrolyte through, respectively, the first electrode and the second electrode such that active flow of the positive liquid electrolyte and the negative liquid electrolyte are stopped one at a time.

14. The method as recited in claim 13 , further including limiting the voltage potential across the first electrode and the second electrode of the flow battery after stopping flow of one of the positive liquid electrolyte and the negative liquid electrolyte and before stopping flow of the other of the negative liquid electrolyte and the positive liquid electrolyte.

15. The method as recited in claim 6 , wherein the transitioning includes stopping the flow battery from the active, charge/discharge mode into the inactive, shut-down mode, and filling the first electrode and the second electrode with a cover gas selected from the group consisting of air, nitrogen, argon, helium, hydrogen and combinations thereof.

16. The flow battery as recited in claim 1 , wherein the voltage-limiting device includes a rheostat.

17. The flow battery as recited in claim 1 , wherein the voltage-limiting device includes a rechargeable battery.

18. The flow battery as recited in claim 1 , wherein the resistors are gate transistors.

19. The flow battery as recited in claim 1 , wherein the at least one liquid electrolyte includes two liquid electrolytes, and the controller is configured to feed the two liquid electrolytes into the at least one cell one at a time during the transition.

20. The flow battery as recited in claim 1 , wherein the at least one liquid electrolyte includes two liquid electrolytes, and the controller is configured to stop feeding of the tw

Assignees

• United Technologies Corp

Inventors

• Darling Robert Mason
• Perry Michael L

Classifications

• H01M8/20

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

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M10/425

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title

• H01M8/04223

  during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells · CPC title

• H01M8/04873 Primary

  of the individual fuel cell · CPC title