Moisture and carbon dioxide management system in electrochemical cells

Patent metadata

Field	Value
Publication number	US-11664547-B2
Application number	US-202117245614-A
Country	US
Kind code	B2
Filing date	Apr 30, 2021
Priority date	Jul 22, 2016
Publication date	May 30, 2023
Grant date	May 30, 2023

Abstract

An electrochemical cell utilizes an air flow device that draws air through the cell from a scrubber that may be removed while the system is operating. The negative pressure generated by the air flow device allows ambient air to enter the cell housing when the scrubber is removed, thereby enabling continued operation without the scrubber. A moisture management system passes outflow air from the cell through a humidity exchange module that transfers moisture to the air inflow, thereby increasing the humidity of the air inflow. A recirculation feature comprising a valve allow a controller to recirculate at least a portion of the outflow air back into the inflow air. The system may comprise an inflow bypass conduit and valve that allows the humidified inflow air to pass into the cell inlet without passing through the scrubber. The scrubber may contain reversible or irreversible scrubber media.

First claim

What is claimed is:

1. An electrochemical cell comprising:
a cell housing comprising:
i) an air chamber;
ii) an air chamber inflow port;
iii) an air chamber outlet;
iv) an electrolyte chamber for retaining a volume of an electrolyte;

an oxidant reduction electrode for reducing a gaseous oxidant configured between the air chamber and the electrolyte chamber;
a fuel electrode;
wherein a fuel is reacted at the fuel electrode and wherein the fuel electrode is positioned apart from the oxidant reduction electrode, thereby defining a gap, and wherein said electrolyte is in the gap;

a scrubber module comprising an enclosure comprising:
i) a scrubber media;
ii) a scrubber inlet port configured to couple with an inlet air outflow port; and
iii) a scrubber outlet port configured to couple with the air chamber inflow port;

wherein the scrubber module is detachably attachable to said cell housing, and whereby the electrochemical cell operates when the scrubber module is removed, and a recirculation feature that transfers a portion of exhaust airflow to the inlet airflow,
whereby at least a portion of an exhaust airflow from said air chamber is transferred through said recirculation feature into the inlet airflow.

2. The electrochemical cell of claim 1 , wherein the electrolyte is an ionically conductive liquid electrolyte.

3. The electrochemical cell of claim 2 , wherein the fuel electrode comprises a metal fuel and is configured at least partially within the electrolyte wherein the fuel electrode is positioned apart from the oxidant reduction electrode, thereby defining a gap, and wherein said ionically conductive liquid electrolyte is in the gap.

4. The electrochemical cell of claim 1 , wherein a flow of air entering the cell housing through the air chamber inflow port and from the scrubber module has less carbon dioxide than a flow of air entering the scrubber module through the outflow port from the cell housing.

5. The electrochemical cell of claim 1 , wherein the scrubber media is irreversible scrubber media.

6. The electrochemical cell of claim 5 , wherein the irreversible scrubber media is selected from the group of consisting of: soda lime, sodium hydroxide, potassium hydroxide, and lithium hydroxide, lithium peroxide, calcium oxide, calcium carbonate, serpentinite, magnesium silicate, magnesium hydroxide, olivine, molecular sieves, amines, and monoethanolamine, and/or derivatives and/or combinations thereof.

7. The electrochemical cell of claim 1 , wherein the scrubber media comprises a reversible scrubber media.

8. The electrochemical cell of claim 7 , wherein the reversible scrubber media comprises amine groups.

9. The electrochemical cell of claim 1 , wherein the scrubber module comprises a heating element.

10. The electrochemical cell of claim 9 , wherein the heating element is a passive heating element that directs heat from the electrochemical cell to the scrubber media.

11. The electrochemical cell of claim 9 , wherein the heating element comprises an electric heating element that is controlled by a control system comprising a microprocessor.

12. The electrochemical cell of claim 1 , wherein the housing comprises a humidity exchange module comprising:
a) a humidity exchange membrane configured between the inlet airflow to the cell housing and an exhaust airflow received from the air chamber;
wherein the humidity exchange membrane comprises an inflow side exposed to the inlet airflow and an outflow side exposed to the exhaust airflow; and
wherein the exhaust airflow comprises moisture and wherein said moisture is transferred through said humidity exchange membrane to the inlet airflow.

13. The electrochemical cell of claim 12 , wherein the humidity exchange membrane comprises an ionically conductive polymer or a perfluorosulfonic acid polymer.

14. The electrochemical cell of claim 12 , wherein the inlet airflow flows into the scrubber module after passing through the humidity exchange module.

15. The electrochemical cell of claim 1 , wherein the recirculation feature is a valve and wherein the valve is controlled by the control system.

16. The electrochemical cell of claim 1 , wherein the recirculation feature is a baffle and wherein the baffle is passively controlled by a pressure differential between the exhaust airflow and the inlet airflow.

17. The electrochemical cell of claim 1 , wherein recirculation feature is configured upstream of the humidity exchange membrane module, wherein a portion of the exhaust airflow is recirculated into the inlet airflow after passing through the humidity exchange module.

18. The electrochemical cell of claim 12 , comprising an airflow device configured to expel exhaust airflow from the cell housing;
wherein the airflow device creates a reduced pressure within the cell housing that draws the inlet airflow into the cell housing, through the inflow side of the humidity exchange membrane module, through the scrubber module, through the air chamber and through the outflow side of the humidity exchange membrane module.

19. The electrochemical cell of claim 12 , wherein the reduced pressure within the cell housing by drawing a flow of ambient airflow through the inflow port to the scrubber module when the scrubber is detached from the electrochemical cell.

20. The electrochemical cell of claim 1 , further comprising an inflow bypass valve and inflow bypass conduit, wherein the inflow bypass conduit diverts inlet airflow to the cell chamber without passing through the scrubber module.

21. The electrochemical cell of claim 20 , wherein the inflow bypass valve is controlled by the control system.

22. An electrochemical cell comprising:
a cell housing comprising:
v) an air chamber;
vi) an air chamber inflow port;
vii) an air chamber outlet;
viii) an electrolyte chamber for retaining a volume of an electrolyte;

an oxidant reduction electrode for reducing a gaseous oxidant configured between the air chamber and the electrolyte chamber;
a fuel electrode;
wherein a fuel is reacted at the fuel electrode and wherein the fuel electrode is positioned apart from the oxidant reduction electrode, thereby defining a gap, and wherein said electrolyte is in the gap;

a scrubber module comprising an enclosure comprising:
i) a scrubber media;
ii) a scrubber inlet port configured to couple with an inlet air outflow port; and
iii) a scrubber outlet port configured to couple with the air chamber inflow port;

wherein the scrubber module is detachably attachable to said cell housing, and whereby the electrochemical cell operates when the scrubber module is removed, and further comprising a bypass adapter that comprises a conduit that couples the outflow port to the inflow port, wherein the bypass adapter diverts inlet airflow to the cell chamber without passing through the scrubber module.

Assignees

• Form Energy Inc

Inventors

• Krishnan Ramkumar
• Hayes Joel
• Fink Shawn
• Klug Scott
• Samuelson Patrick

Classifications

• H01M8/04149

  by diffusion, e.g. making use of membranes · CPC title

• H01M8/04179

  by purging or increasing flow or pressure of reactants · CPC title

• H01M12/02 Primary

  Details (of electrodes H01M4/00; of non-active parts H01M50/00) · CPC title

• H01M4/38 Primary

  of elements or alloys · CPC title

• H01M12/06

  with one metallic and one gaseous electrode · CPC title