Method of operating electrochemical cells comprising electrodeposited fuel

• US 10,461,554 B2
• Filed: 10/28/2016
• Issued: 10/29/2019
• Est. Priority Date: 02/12/2014
• Status: Active Grant

• Current Assignee: Form Energy, Inc.
• Original Assignee: NantEnergy, Inc.
• Inventors: Friesen, Cody A., Hayes, Joel, Puzhaev, Sergey, Krishnan, Ramkumar, Trimble, Todd
• Primary Examiner(s): Isla, Richard
• Assistant Examiner(s): Hernandez, Manuel
• Application Number:
  US15/337,772
• Publication Number:
  US 20170047757A1
• Time in Patent Office: 1,096 Days
• Field of Search: 320134, 429402-407
• CPC Class Codes: H01M 10/06 Lead-acid accumulators semi-lead accumulators H01M10/20
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/4242 Regeneration of electrolyte or reactants
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/448 End of discharge regulating measures
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 12/08 composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
• CPC Class Codes: H01M 2010/4292 Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode
• CPC Class Codes: H01M 8/04895 Current
• CPC Class Codes: H01M 8/2404 Processes or apparatus for grouping fuel cells
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

An electrochemical cell system and a process for operating the same, the system having at least two fuel electrodes for receiving electrodeposited metal fuel; at least one oxidant electrode spaced apart from the fuel electrode; at least one charging electrode; an ionically conductive medium communicating the electrodes of the electrochemical cell system for conducting ions to support electrochemical reactions at the fuel, oxidant, and charging electrodes; and, one or more controllers configured to operate the cell system in discharging and charging modes and monitor a state of charge for each fuel electrode. The controllers may assign each fuel electrode in a discharging unit having a state-of-charge meeting a predetermined depletion criteria from the discharging unit to the charging unit, and each fuel electrode in the charging unit having a state-of-charge meeting a predetermined loading criteria from the charging unit to the discharging unit.

Claims

1. A process for operating an electrochemical cell system, wherein the electrochemical cell system comprises:

(i) at least two fuel electrodes for receiving electrodeposited metal fuel;

(ii) at least one oxidant electrode spaced apart from the fuel electrodes;

(iii) at least one charging electrode;

(iv) an ionically conductive medium communicating the electrodes of the electrochemical cell system for conducting ions to support electrochemical reactions at the fuel, oxidant, and charging electrodes, the ionically conductive medium comprising reducible metal fuel ions;

wherein the process comprises;

(i) assigning the fuel electrodes into units, the units comprising;

a discharging unit and a charging unit;

(ii) operating said cell system in a discharge mode wherein the metal fuel is oxidized at each fuel electrode in the discharging unit and an oxidant is reduced at the at least one oxidant electrode to generate an electrical discharge current therebetween for application to a load;

(iii) operating said cell system in a charging mode wherein a reducible species of the fuel is reduced to electrodeposit the fuel on each fuel electrode in the charging unit and oxidize an oxidizable species of the oxidant at the charging electrode by application of an electrical charge current therebetween from a power source;

(iv) monitoring each of the fuel electrodes in the discharging unit during said discharge mode, wherein each fuel electrode in the discharging unit meeting a predetermined depletion criteria is assigned from the discharging unit to the charging unit, and wherein each fuel electrode not meeting the predetermined depletion criteria remains assigned to the discharging unit including for a subsequent discharge mode; and

(v) monitoring each of the fuel electrodes in the charging unit during said charging mode, wherein each fuel electrode in the charging unit meeting a predetermined loading criteria is assigned from the charging unit to the discharging unit, and wherein each fuel electrode not meeting the predetermined loading criteria remains assigned to the charging unit including for a subsequent charge mode.

2. The process according to claim 1, wherein the charging electrode is selected from the group consisting of (a) the oxidant electrode, (b) a third electrode, and (c) part of the fuel electrode.

3. The process according to claim 1, wherein the predetermined depletion criteria is a state-of-charge below a threshold in the range of 0% to 20%.

4. The process according to claim 1, wherein the predetermined depletion criteria is a voltage below a threshold of approximately 1.0 volts.

5. The process according to claim 1, wherein the predetermined loading criteria is state-of-charge above a threshold in the range of 90% to 100%.

6. The process according to claim 1, wherein the predetermined loading criteria is a voltage above a threshold of approximately 2.5 volts.

7. The process according to claim 1, wherein the units into which fuel electrodes are distributed further comprises a conditioning unit;

and, the process further comprises conditioning each fuel electrode within the conditioning unit.

8. The process according to claim 7, wherein the conditioning of each of the fuel electrodes within the conditioning unit comprises a resetting process configured to remove dendritic formations present at each fuel electrode in the conditioning unit.

9. The process according to claim 7, wherein the conditioning each fuel electrode within the conditioning unit comprises charge-discharge pulsing to remove dendritic formations at each fuel electrode in the conditioning unit.

10. The process according to claim 7, wherein the conditioning each fuel electrodes within the conditioning unit comprises discharging electrical discharge current from the fuel electrodes in the conditioning unit for application to the load.

11. An electrochemical cell system, wherein the electrochemical cell system comprises:

(i) at least two fuel electrodes for receiving electrodeposited metal fuel;

(ii) at least one oxidant electrode spaced apart from the fuel electrodes;

(iii) at least one charging electrode;

(iv) an ionically conductive medium communicating the electrodes of the electrochemical cell system for conducting ions to support electrochemical reactions at the fuel, oxidant, and charging electrodes, the ionically conductive medium comprising reducible metal fuel ions;

and,

one or more controllers configured to;

assign the fuel electrodes into units, the units comprising;

a discharging unit and a charging unit;

operate the cell system in a discharging mode wherein the metal fuel is oxidized at each fuel electrode in the discharging unit and an oxidant is reduced at the at least one oxidant electrode to generate an electrical discharge current therebetween for application to a load;

operate the cell system in a charging mode wherein a reducible species of the fuel is reduced to electrodeposit the fuel on each fuel electrode in the charging unit and oxidize an oxidizable species of the oxidant at the charging electrode by application of an electrical charge current therebetween from a power source;

monitor each of the fuel electrodes in the discharging unit during said discharge mode, wherein the one or more controllers is further configured to assign each fuel electrode in the discharging unit meeting a predetermined depletion criteria from the discharging unit to the charging unit and wherein each fuel electrode not meeting the predetermined depletion criteria remains assigned to the discharging unit including for a subsequent discharge mode, and

monitor each of the fuel electrodes in the charging unit during said charging mode, wherein the one or more controllers is further configured to assign each fuel electrode in the charging unit meeting a predetermined loading criteria from the charging unit to the discharging unit and wherein each fuel electrode not meeting the predetermined loading criteria remains assigned to the charging unit including for a subsequent charge mode.

12. The electrochemical cell system according to claim 11, the charging electrode being selected from the group consisting of (a) the oxidant electrode, (b) a third electrode, and (c) part of the fuel electrode.

13. The electrochemical cell system according to claim 11, wherein the fuel electrode of the first electrochemical cell comprises a series of permeable electrode bodies arranged in spaced apart relation.

14. The electrochemical cell system according to claim 11, wherein the electrochemical cell system further comprises a switching system, wherein the switching system comprises a switch associated with each fuel electrode of the electrochemical cell system.

15. The electrochemical cell system according to claim 14, wherein said switch is configured to operate as a variable resistor;

and wherein the resistance of said switch is regulated by the controller.

16. The electrochemical cell system according to claim 11, wherein the predetermined depletion criteria is a state-of-charge below a threshold.

17. The electrochemical cell system according to claim 11, wherein the predetermined depletion criteria is a voltage below a threshold.

18. The electrochemical cell system according to claim 11, wherein the predetermined loading criteria is state-of-charge above a threshold.

19. The electrochemical cell system according to claim 11, wherein the predetermined loading criteria is a voltage above a threshold.