Moisture and carbon dioxide management system in electrochemical cells

Patent metadata

Field	Value
Publication number	US-11018387-B2
Application number	US-201716318513-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Jul 22, 2016
Publication date	May 25, 2021
Grant date	May 25, 2021

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 inlet;
iii) an air chamber outlet;
iv) an electrolyte chamber, an ionically conductive liquid electrolyte in the electrolyte chamber;

an oxidant reduction electrode for reducing a gaseous oxidant between the air chamber and the electrolyte chamber, and
a fuel electrode;
an air intake for drawing ambient air into the cell housing;
an air outflow port communicated with the air intake;
an air inflow port communicated with the air chamber inlet;
an airflow device configured to draw inlet airflow into the cell housing through the air intake;
a scrubber module configured to be connected to the inflow port and the outflow port for removing carbon dioxide from the inlet airflow, the scrubber module comprising an enclosure comprising:
i) a scrubber media;
ii) a scrubber inlet port configured to couple with the air outflow port; and
iii) a scrubber outlet port configured to couple with the air 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
wherein the airflow device is operable and configured to draw the inlet airflow into the cell housing through the air inflow port when the scrubber module is removed.

2. The electrochemical cell of claim 1 , 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.

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

4. The electrochemical cell of claim 3 , 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.

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

6. The electrochemical cell of claim 5 , wherein the reversible scrubber media comprises amine groups.

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

8. The electrochemical cell of claim 7 , wherein the heating element is a passive heating element that directs heat from the electrochemical cell to the scrubber media.

9. The electrochemical cell of claim 7 , wherein the heating element comprises an electric heating element that is controlled by a control system comprising a microprocessor.

10. The electrochemical cell of claim 1 , wherein the cell housing comprises a humidity exchange module comprising:
a) a humidity exchange membrane configured between the air intake and an exhaust airflow received from the air chamber outlet;
wherein the humidity exchange membrane comprises an inflow side exposed to the inlet airflow drawn through the air intake upstream of the air outflow port 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.

11. The electrochemical cell of claim 10 , wherein the humidity exchange membrane comprises an ionically conductive polymer.

12. The electrochemical cell of claim 10 , wherein the humidity exchange membrane comprises a perfluorosulfonic acid polymer.

13. The electrochemical cell of claim 10 , wherein the airflow flows into the scrubber module after passing through the humidity exchange module.

14. The electrochemical cell of claim 1 , further comprising a recirculation feature that transfers a portion of exhaust airflow from said air chamber outlet into the inlet airflow drawn through the air intake.

15. The electrochemical cell of claim 10 , further comprising a recirculation feature that transfers a portion of exhaust airflow from said air chamber outlet into the inlet airflow drawn through the air intake.

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

17. The electrochemical cell of claim 15 , 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.

18. The electrochemical cell of claim 15 , 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.

19. The electrochemical cell of claim 10 , wherein the airflow device is configured to draw the inlet airflow into the cell housing, through the inflow side of the humidity exchange membrane, through the scrubber, through the air chamber and through the outflow side of the humidity exchange membrane module.

20. The electrochemical cell of claim 1 , wherein the airflow device is configured to create a reduced pressure within the cell housing by drawing a flow of ambient airflow through the air inflow port when the scrubber is detached from the electrochemical cell.

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

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

23. The electrochemical cell of claim 1 , 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 through the bypass adapter and to the cell chamber without passing through the scrubber module.

24. An electrochemical cell of claim 1 , further comprising:
a) a humidity exchange module and a recirculation feature,
the humidity exchange module comprising:
a humidity exchange membrane configured between the inlet airflow to the cell housing and an exhaust airflow received from the air chamber outlet;

wherein the humidity exchange membrane comprises an inflow side exposed to the inlet airflow drawn through the air intake upstream of the air outflow port 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;
the recirculation feature being configured to transfer a portion of exhaust airflow to the inlet airflow,
whereby at least a portion of an exhaust airflow from said air chamber outlet is transferred through said recirculation feature into the inlet airflow.

25. The electrochemical cell of claim 1 , further comprising a manifold assembly,
wherein the air intake, the air inflow port, and the air outflow port are part of the manifold assembly; and wherein the airflow device is provided in the manifold assembly.

26. A method of conserving moisture within an electrochemical cell comprising the steps of:
a) providi

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

• H01M8/04104

  Regulation of differential pressures · CPC title

• H01M12/02 Primary

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

• H01M8/04141

  by water containing exhaust gases · CPC title

• H01M8/0668

  Removal of carbon monoxide or carbon dioxide · CPC title