ELECTROCHEMICAL CELL WITH FLOW MANAGEMENT SYSTEM

• US 20110086278A1
• Filed: 10/08/2010
• Published: 04/14/2011
• Est. Priority Date: 10/08/2009
• Status: Active Grant

• Current Assignee: Form Energy, Inc.
• Original Assignee: Fluidic, Inc.
• Inventors: Friesen, Cody A., Friesen, Grant, Krishnan, Ramkumar
• Granted Patent: US 8,492,052 B2
• Time in Patent Office: Days
• US Class Current: 429/402
• CPC Class Codes: H01M 10/4214 Arrangements for moving electrodes or electrolyte
• 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 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 12/065 with plate-like electrodes or stacks of plate-like electrodes
• 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 50/70 Arrangements for stirring or circulating the electrolyte
• CPC Class Codes: H01M 50/77 with external circulating path
• CPC Class Codes: H01M 8/0273 with sealing or supporting means in the form of a frame
• CPC Class Codes: H01M 8/04186 of liquid-charged or electrolyte-charged reactants
• CPC Class Codes: H01M 8/188 by recharging of redox couples containing fluids; Redox flow type batteries
• CPC Class Codes: H01M 8/2455 with liquid, solid or electrolyte-charged reactants
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

An electrochemical cell includes a fuel electrode configured to operate as an anode to oxidize a fuel when connected to a load. An electrode holder includes a cavity for holding the fuel electrode, at least one inlet connected to the cavity on one side of the cavity and configured to supply an ionically conductive medium to the cavity, and at least one outlet connected to the cavity on an opposite side of the cavity and configured to allow the ionically conductive medium to flow out of the cavity. A plurality of spacers extend across the fuel electrode and the cavity in a spaced relation from each other to define a plurality of flow lanes in the cavity.

Claims

1. An electrochemical cell comprising:

a fuel electrode;

an oxidant electrode spaced from the fuel electrode;

an ionically conductive medium contacting the electrodes;

the fuel electrode and the oxidant electrode being configured to, during discharge, oxidize a metal fuel at the fuel electrode and reduce an oxidant at the oxidant electrode to generate a discharge potential difference therebetween for application to a load;

an electrode holder comprising a cavity for holding the fuel electrode, at least one inlet connected to the cavity on one side of the cavity and configured to supply the ionically conductive medium to the cavity, and at least one outlet connected to the cavity on an opposite side of the cavity as the at least one inlet and configured to allow the ionically conductive medium to flow out of the cavity; and

a plurality of spacers extending across the fuel electrode and the cavity in a spaced relation from each other to define a plurality of flow lanes in the cavity so that the ionically conductive medium flows into each flow lane via the at least one inlet, across the fuel electrode, and out of the flow lane via the at least one outlet.

2. An electrochemical cell according to claim 1, further comprising a charging electrode, wherein the fuel electrode and the charging electrode are configured to, during re-charge, reduce a reducible species of the fuel to electrodeposit the fuel on the fuel electrode and oxidize an oxidizable species of the oxidant by application of a re-charge potential difference therebetween from a power source.

3. An electrochemical cell according to claim 2, wherein the charging electrode is selected from the group consisting of (a) the oxidant electrode, (b) a third electrode spaced from the oxidant electrode, and (c) a portion of the fuel electrode.

4. An electrochemical cell according to claim 3, wherein the fuel electrode comprises a plurality of permeable electrode bodies in spaced relation, and wherein the charging electrode during re-charge is a dynamic charging electrode comprising at least some of the permeable electrode bodies.

5. An electrochemical cell according to claim 1, wherein each spacer is attached at opposite ends thereof to the electrode holder in tension to secure the fuel electrode to the electrode holder.

6. An electrochemical cell according to claim 5, wherein each spacer comprises an elongated center portion and a shaped end portion at each end of the elongated center portion, and wherein the electrode holder comprises a plurality of shaped openings that correspond to the shaped end portions of the spacers so that the ends of each spacer may be held by the shaped openings in the electrode holder.

7. An electrochemical cell according to claim 6, wherein the shaped end portions and shaped openings have a substantially triangular shape.

8. An electrochemical cell according to claim 1, wherein the at least one inlet comprises a plurality of inlets, wherein the at least one outlet comprises a plurality of outlets, and wherein one of the plurality of inlets and one of the plurality of outlets are associated with reach flow lane so that the ionically conductive medium flows into each flow lane via the associated inlet, across the fuel electrode, and out of the flow lane via the associated outlet.

9. An electrochemical cell according to claim 8, wherein the cavity comprises diverging surfaces at the inlet of each flow lane, the diverging surfaces partially defining a volume in which particulates in the flow lane are fluidized with the ionically conductive medium flowing into the flow lane.

10. An electrochemical cell according to claim 1, wherein the inlets are configured to provide a pressure drop between an inlet channel in the electrode holder and the flow lanes.

11. An electrochemical cell according to claim 1, wherein the fuel electrode comprises a plurality of permeable bodies in spaced relation, and wherein the plurality of spacers are provided in between the permeable bodies to allow the ionically conductive medium to permeate through the permeable bodies and to flow across the permeable bodies in the flow lanes.

12. An electrochemical cell according to claim 1, wherein each flow lane is three-dimensional and has a height substantially equal to the spacers that define the flow lane.

13. An electrochemical cell according to claim 1, wherein the fuel when oxidized during discharge forms an oxide in the ionically conductive medium.

14. An electrochemical cell according to claim 1, wherein each spacer is molded into or onto the fuel electrode.

15. An electrochemical cell according to claim 14, wherein the fuel electrode comprises a plurality of permeable bodies in spaced relation, and wherein the plurality of spacers are molded into or onto the permeable bodies to hold the permeable bodies in a spaced relation and allow the ionically conductive medium to permeate through the permeable bodies and to flow across the permeable bodies in the flow lanes.

16. A method for manufacturing a fuel electrode for an electrochemical cell, the fuel electrode comprising a plurality of permeable electrode bodies and a plurality of substantially parallel spacers extending between the permeable electrode bodies, the method comprising:

injecting a material into a plurality of cavities, each cavity being defined by two manufacturing spacers, the adjacent permeable electrode bodies being held substantially parallel to and spaced from each other with the manufacturing spacers therebetween so that the electrode bodies extend into the cavities, the manufacturing spacers being substantially parallel to each other;

hardening the material to form the substantially parallel spacers of the fuel electrode; and

separating the permeable electrode bodies from the manufacturing spacers so that the permeable electrode bodies and the substantially parallel spacers formed from the material are a single integral unit.

17. A method for manufacturing according to claim 16, wherein the plurality of cavities are formed in a mold.

18. A method for manufacturing according to claim 17, wherein the manufacturing spacers are integral parts of the mold.

19. A method for manufacturing according to claim 16, wherein the manufacturing spacers are individual parts.

20. A method for charging an electrochemical cell, the electrochemical cell comprising

a fuel electrode;

an oxidant electrode spaced from the fuel electrode;

a charging electrode;

an ionically conductive medium contacting the electrodes;

the fuel electrode and the oxidant electrode being configured to, during discharge, oxidize a metal fuel at the fuel electrode and reduce an oxidant at the oxidant electrode to generate a discharge potential difference therebetween for application to a load;

the fuel electrode and the charging electrode being configured to, during re-charge, reduce a reducible species of the fuel to electrodeposit the fuel on the fuel electrode and oxidize an oxidizable species of the oxidant by application of a re-charge potential difference therebetween from a power source;

an electrode holder comprising a cavity for holding the fuel electrode, at least one inlet connected to the cavity on one side of the cavity and configured to supply the ionically conductive medium to the cavity, and at least one outlet connected to the cavity on an opposite side of the cavity as the at least one inlet and configured to allow the ionically conductive medium to flow out of the cavity; and

a plurality of spacers extending across the fuel electrode and the cavity in a spaced relation from each other to define a plurality of flow lanes in the cavity so that the ionically conductive medium flows into each flow lane via the at least one inlet, across the fuel electrode, and out of the flow lane via the at least one outlet,

the method comprising;

flowing the ionically conductive medium comprising reducible fuel species through the at least one inlet and into the flow lanes;

applying an electrical current between the charging electrode and the fuel electrode with the charging electrode functioning as an anode and the fuel electrode functioning as a cathode, such that the reducible fuel species are reduced and electrodeposited as fuel in oxidizable form on the fuel electrode; and

removing the electrical current to discontinue the charging.

21. A method for charging according to claim 20, wherein the charging electrode is selected from the group consisting of (a) the oxidant electrode, (b) a third electrode spaced from the oxidant electrode, and (c) a portion of the fuel electrode.

22. An electrochemical cell according to claim 21, wherein the fuel electrode comprises a plurality of permeable electrode bodies in spaced relation, and wherein the charging electrode is a dynamic charging electrode and comprises at least some of the permeable electrode bodies during re-charge.