Electrochemical cell system with a progressive oxygen evolving electrode / fuel electrode

• US 9,178,207 B2
• Filed: 09/12/2011
• Issued: 11/03/2015
• Est. Priority Date: 09/16/2010
• Status: Active Grant

• Current Assignee: Form Energy, Inc.
• Original Assignee: Fluidic, Inc.
• Inventors: Friesen, Cody A., Krishnan, Ramkumar, Trimble, Todd, Puzhaev, Sergey
• Primary Examiner(s): Dunn, Drew A
• Assistant Examiner(s): Zhou, Zixuan
• Application Number:
  US13/230,549
• Publication Number:
  US 20120068667A1
• Time in Patent Office: 1,513 Days
• Field of Search: 320/122
• US Class Current: 1/1
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• 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 2004/025 with shapes other than plane or cylindrical
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/045 Electrochemical coating; Electrochemical impregnation
• CPC Class Codes: H01M 4/667 in the form of layers, e.g. coatings
• CPC Class Codes: H01M 4/70 characterised by shape or form
• CPC Class Codes: H01M 50/77 with external circulating path
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

One aspect of the present invention provides an electrochemical cell system comprising at least one electrochemical cell configured to be selectively connected to a load to discharge the cell by generating electrical current using a fuel and an oxidant. The electrochemical cell system may alternatively be connected to a power supply to recharge the cell. The electrochemical cell system comprises a plurality of electrodes and electrode bodies therein. The electrochemical cell system further comprises a switching system configured to permit progressive movement of the anodes used for charging each electrochemical cell, maintaining a minimum distance from a progressively moving cathode that is the site of fuel growth.

Claims

1. A rechargeable electrochemical cell system for generating electrical current using a metal fuel and an oxidant, the cell system comprising:

an electrochemical cell comprising;

(i) a fuel electrode comprising N permeable electrode bodies arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies;

(ii) an oxidant electrode spaced apart from the fuel electrode;

(iii) a charging electrode selected from the group consisting of (a) the oxidant electrode, and (b) a separate charging electrode spaced from the fuel and oxidant electrodes; and

(iv) an ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes;

wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load;

a plurality of switches for selectively coupling each electrode body 2 to N of the fuel electrode and the charging electrode to a power source for application of an anodic potential during a re-charging mode in which a cathodic potential is applied to electrode body 1 by the power source;

a controller configured to control the plurality of switches during the re-charging mode to manage application of the anodic potential from the power source to the permeable electrode bodies 2 to N and the charging electrode in a progressive manner so as to cause (a) electrodeposition of the metal fuel, via reduction of reducible ions of the metal fuel from the ionically conductive medium, to grow progressively from electrode body 1 towards the charging electrode with the electrodeposition progressively connecting each subsequent electrode body 2 to N to the electrode body 1 for application of the cathodic potential to each subsequently connected electrode body, (b) removal of the anodic potential from each subsequently connected electrode body, and (c) application of the anodic potential to at least the subsequent electrode body unconnected by the electrodeposition, or the charging electrode where electrode body N has been connected by the electrodeposition, for oxidation of an oxidizable species of the oxidant.

2. The electrochemical cell system according to claim 1, further comprising a plurality of the electrochemical cells assembled adjacent one another with a non-conductive barrier separating the oxidant electrode and fuel electrode of each pair of adjacent cells, such that the only permitted electrical connection therebetween is via at least one of said plurality of switches.

3. The electrochemical cell system according to claim 2, wherein said plurality of switches are switchable to a bypass mode for each cell by coupling the charging electrode, in the charge mode, or the oxidant electrode, in the discharge mode, of a previous cell to the fuel electrode of a subsequent cell.

4. The electrochemical cell system according to claim 2, wherein the cell is a metal-air cell with the fuel electrode comprising the metal fuel, the oxidant electrode comprising an air cathode for reducing oxygen, and the charging electrode being an oxygen evolving electrode for oxidizing an oxidizable oxygen species to oxygen.

5. The electrochemical cell system according to claim 4, wherein the metal fuel is selected from the group consisting of zinc, aluminum, iron, and manganese.

6. The electrochemical cell system according to claim 4, wherein each non-conductive barrier includes one or more ports for enabling oxygen to flow to the air cathode.

7. The electrochemical cell system according to claim 1, wherein the plurality of switches includes a switch switchable between coupling the cell to the load and coupling the cell to a power supply.

8. The electrochemical cell system according to claim 1, wherein each of said plurality of switches are associated with one of each of the plurality of permeable electrode bodies, the charging electrode, and the oxidant electrode.

9. The electrochemical cell system according to claim 1, wherein said plurality of switches are switchable to progressively connect permeable electrode body 1 through permeable electrode body N to the charging electrode.

10. The electrochemical cell system according to claim 1, wherein said plurality of switches are switchable to selectively connect each of permeable electrode bodies 1 through permeable electrode body N to the charging electrode.

11. The electrochemical cell system according to claim 1, wherein said plurality of switches are switchable to selectively connect each of permeable electrode bodies 1 through permeable electrode body N to the fuel electrode.

12. The electrochemical cell system according to claim 1, further comprising a controller configured to selectively open and close at least one of the plurality of switches.

13. The electrochemical cell system according to claim 12, wherein the controller is configured to be respondent to one or more sensors associated with the cell.

14. The electrochemical cell system according to claim 13, wherein the one or more sensors are configured to measure at least one of an increase in current above a threshold value or a decrease in potential difference above a threshold value between at least two of the permeable electrode bodies.

15. The electrochemical cell system according to claim 12, wherein the controller is further configured to selectively open and close at least one of the plurality of switches to apply the anodic potential to all of permeable electrode bodies 2-N that do not have the cathodic potential.

16. The electrochemical cell system according to claim 12, wherein the controller is further configured to selectively open and close at least one of the plurality of switches to apply the anodic potential to only one of permeable electrode bodies 2-N or the charging electrode, that is adjacent to at least one of permeable electrode bodies 1-N that have the cathodic potential.

17. A method for charging an electrochemical cell, wherein the electrochemical cell comprises:

(i) a fuel electrode comprising N permeable electrode bodies arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies;

(ii) an oxidant electrode spaced apart from the fuel electrode;

(iii) a charging electrode selected from the group consisting of (a) the oxidant electrode, and (b) a separate charging electrode spaced from the fuel and oxidant electrodes; and

(iv) an ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes;

wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load;

the method comprising;

applying a cathodic potential to electrode body 1 by coupling electrode body 1 to a power source;

managing application of an anodic potential to electrode bodies 2 to N by selectively coupling electrode bodies 2 to N to the power source for application of the anodic potential, so as to cause

(a) electrodeposition of the metal fuel, via reduction of reducible ions of the metal fuel from the ionically conductive medium, to grow progressively from electrode body 1 towards the charging electrode with the electrodeposition progressively connecting each subsequent electrode body 2 to N to the electrode body 1 for application of the cathodic potential to each subsequently connected electrode body,

(b) removal of the anodic potential from each subsequently connected electrode body, and

(c) application of the anodic potential to at least the subsequent electrode body unconnected by the electrodeposition, or the charging electrode where electrode body N has been connected by the electrodeposition, for oxidation of an oxidizable species of the oxidant; and

decoupling the power source to discontinue the charging.

18. The method of claim 17, wherein applying the cathodic potential comprises controlling an open/closed state of a plurality of switches associated with the cell.

19. The method of claim 17, wherein managing application of the anodic potential comprises controlling an open/closed state of a plurality of switches associated with the cell.

20. The method of claim 19, wherein controlling an open/closed state of the plurality of switches comprises connecting permeable electrode body 2 through permeable electrode body N to the charging electrode, and progressively disconnecting permeable electrode body 2 through N from the charging electrode as fuel growth electrically connects and applies a cathodic potential from permeable electrode body 1 through N.

21. The method of claim 17, wherein managing application of the anodic potential comprises controlling a plurality of switches by a controller, the controller responsive to at least one sensor associated with the cell.

22. The method of claim 21, wherein the at least one sensor is configured to measure an increase in current above a threshold value or a decrease in potential difference above a threshold value between at least two of the permeable electrode bodies.

23. The method of claim 21, wherein the at least one sensor is configured to measure a passage of an interval of time.

24. An electrochemical cell system for generating electrical current using a metal fuel and an oxidant, the cell system comprising:

an electrochemical cell comprising;

(i) a fuel electrode comprising N permeable electrode bodies arranged in spaced apart relation in order 1 to N, wherein N is an integer greater than or equal to two, the fuel electrode comprising metal fuel on the permeable electrode bodies;

(ii) an oxidant electrode spaced apart from the fuel electrode; and

(iii) an ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes;

wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load;

a plurality of switches for selectively coupling each electrode body 2 to N of the fuel electrode to the load;

one or more sensors associated with the electrode bodies 2 to N, configured to determine the presence of consumable fuel on each electrode body 2 to N; and

a controller configured to control the plurality of switches during the discharging mode so as to disconnect from the load each of the electrode bodies 2 to N which the one or more sensors detect has the fuel depleted therefrom.

25. The electrochemical cell system according to claim 24, wherein the cell is a metal-air cell with the fuel electrode comprising the metal fuel, and the oxidant electrode comprising an air cathode for reducing oxygen.

26. The electrochemical cell system according to claim 24, wherein the metal fuel is selected from the group consisting of zinc, aluminum, iron, and manganese.

27. The electrochemical cell system according to claim 24, wherein the plurality of switches includes a switch switchable between coupling the cell to the load and coupling the cell to a power supply.

28. The electrochemical cell system according to claim 24, wherein each of said plurality of switches are associated with one of the plurality of permeable electrode bodies, and the oxidant electrode.

29. The electrochemical cell system according to claim 24, wherein the controller is configured to be respondent to the one or more sensors associated with the cell.

30. The electrochemical cell system according to claim 24, wherein the one or more sensors is configured to measure one or more of current, resistance, and voltage.

31. The electrochemical cell system according to claim 24, wherein the electrochemical cell system is rechargeable, and wherein the electrochemical cell further comprises:

(iv) a charging electrode selected from the group consisting of (a) the oxidant electrode, (b) a separate charging electrode spaced from the fuel and oxidant electrodes, and (c) a portion of the fuel electrode.

32. The electrochemical cell system according to claim 31, wherein the charging electrode is an oxygen evolving electrode for oxidizing an oxidizable oxygen species to oxygen.

33. The electrochemical cell system according to claim 31, wherein each of said plurality of switches are associated with one of the plurality of permeable electrode bodies, the charging electrode, and the oxidant electrode.

34. A method for discharging an electrochemical cell system, wherein the electrochemical cell system comprises:

an electrochemical cell comprising;

(i) a fuel electrode comprising a plurality of permeable electrode bodies arranged in spaced apart relation, the fuel electrode comprising metal fuel on the permeable electrode bodies;

(ii) an oxidant electrode spaced apart from the fuel electrode; and

(iii) an ionically conductive medium communicating the electrodes for conducting ions to support electrochemical reactions at the electrodes;

wherein the fuel and oxidant electrodes are configured to, during a discharging mode, oxidize the metal fuel on the permeable electrode bodies and reduce the oxidant at the oxidant electrode, thus generating a potential difference for application to a load;

a plurality of switches for selectively coupling each electrode body of the fuel electrode to the load;

one or more sensors associated with the permeable electrode bodies, configured to determine the presence of consumable fuel on each of the permeable electrode bodies; and

a controller configured to control the plurality of switches during the discharging mode so as to disconnect from the load each of the permeable electrode bodies which the one or more sensors detect has fuel depleted therefrom;

the method comprising;

discharging the electrochemical cell as connected to the load, so as to consume metal fuel from the permeable electrode bodies;

sensing, with the one or more sensors, depletion of the metal fuel from the one or more of the permeable electrode bodies;

disconnecting from the load, using the plurality of switches, each of the one or more of the permeable electrode bodies depleted of metal fuel; and

continuing said discharging, sensing, and disconnecting until all metal fuel is depleted from the fuel electrode, or no further discharging is desired.

35. The method according to claim 34, wherein said sensing is controlled by the controller.

36. The method according to according to claim 34, wherein said sensing comprises measuring one or more of current, resistance, and voltage.