Control, collection and use of metal-air battery pack effluent

• US 8,557,414 B2
• Filed: 02/25/2011
• Issued: 10/15/2013
• Est. Priority Date: 08/10/2010
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Hermann, Weston Arthur, Straubel, Jeffrey Brian
• Primary Examiner(s): Walls, Cynthia K.
• Application Number:
  US13/035,776
• Publication Number:
  US 20120041628A1
• Time in Patent Office: 963 Days
• Field of Search: None
• US Class Current: 429/50
• CPC Class Codes: H01M 10/445 in response to gas pressure
• 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 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/0606 with means for production of gaseous reactants
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A system and method for maintaining an ambient oxygen concentration below a preset concentration while charging a metal-air battery pack is provided, the system utilizing an on-board means for collecting and storing the oxygen-rich effluent generated during the charge cycle.

Claims

1. A battery pack control system, comprising:

a battery pack comprised of at least one metal-air cell and further comprised of a battery pack air outlet and a battery pack air inlet, wherein said battery pack is configured for use within an electric vehicle and to provide power to said electric vehicle, wherein said battery pack is coupleable to a battery pack charging system, and wherein said battery pack generates oxygen-rich effluent during charging;

at least one oxygen concentration sensor;

a gas tank mounted within said electric vehicle, wherein said battery pack air outlet is coupled to a tank inlet of said gas tank, and wherein said battery pack air inlet is coupled to a tank outlet of said gas tank;

a compressor interposed between said battery pack air outlet and said tank inlet, said compressor configured to compress said oxygen-rich effluent from said battery pack air outlet prior to filling said gas tank with said oxygen-rich effluent;

an exhaust port coupled to said battery pack air outlet; and

a system controller coupled to said at least one oxygen concentration sensor and receiving an output data signal from said at least one oxygen concentration sensor, said system controller configured to determine an oxygen concentration level based on said output data signal from said at least one oxygen concentration sensor, wherein said system controller is configured to pass said oxygen-rich effluent through said exhaust port when said oxygen concentration level is below a preset concentration level and to pass said oxygen-rich effluent to said compressor and said tank inlet when said oxygen concentration level is greater than said preset concentration level.

2. The battery pack control system of claim 1, further comprising a state-of-charge (SOC) detection system, wherein said SOC detection system monitors SOC for said battery pack, and wherein said system controller terminates operation of said battery pack charging system when said SOC for said battery pack reaches a target SOC level.

3. The battery pack control system of claim 1, wherein said at least one oxygen sensor is mounted proximate to said exhaust port.

4. The battery pack control system of claim 1, wherein said at least one oxygen sensor is mounted on said electric vehicle and monitors an external vehicle environment.

5. The battery pack control system of claim 1, wherein said system controller is configured to pass said oxygen-rich effluent through said exhaust port upon initiation of battery pack charging.

6. The battery pack control system of claim 1, wherein said system controller is configured to pass said oxygen-rich effluent to said compressor and said tank inlet upon initiation of battery pack charging, and wherein said system controller is configured to pass said oxygen-rich effluent through said exhaust port when said oxygen concentration level is below said preset concentration level and said gas tank is full.

7. The battery pack control system of claim 1, further comprising a heat exchanger interposed between said battery pack outlet and said compressor.

8. The battery pack control system of claim 1, wherein said system controller is configured to pass said oxygen-rich effluent stored in said gas tank to said battery pack air inlet during a battery pack discharge cycle.

9. A method of operating a metal-air battery pack mounted within an electric vehicle, the method comprising the steps of:

coupling said metal-air battery pack to an external charging power source via a battery charging system, wherein an oxygen-rich effluent is generated during charging of said metal-air battery pack;

coupling a battery pack air outlet to a tank inlet of a gas tank mounted within said electric vehicle, wherein a compressor is interposed between said battery pack outlet and said tank inlet;

compressing said oxygen-rich effluent passing through said battery pack air outlet with said compressor;

storing said oxygen-rich effluent compressed by said compressor within said gas tank;

monitoring a fill level corresponding to said gas tank;

comparing said fill level to a maximum tank level;

coupling said battery pack air outlet to an ambient air exhaust system when said fill level reaches said maximum tank level; and

decoupling said battery pack air outlet from said tank inlet and terminating said compressing and storing steps when said fill level reaches said maximum tank level.

10. The method of claim 9, further comprising the steps of:

determining a present metal-air battery pack state-of-charge (SOC);

comparing said present metal-air battery pack SOC with a target SOC; and

terminating charging of said metal-air battery pack when said present metal-air battery pack SOC reaches or exceeds said target SOC.

11. The method of claim 9, further comprising the steps of:

determining an oxygen concentration level within a first region corresponding to said electric vehicle;

comparing said oxygen concentration level to a preset oxygen concentration level;

suspending charging of said metal-air battery pack if said oxygen concentration level exceeds said preset oxygen concentration level; and

resuming charging of said metal-air battery pack when said oxygen concentration level falls below said preset oxygen concentration level.

12. The method of claim 9, further comprising the steps of decoupling said battery pack air outlet from said ambient air exhaust system and opening an ambient air battery pack inlet during a battery pack discharge cycle.

13. The method of claim 9, further comprising the steps of:

decoupling said battery pack air outlet from said ambient air exhaust system during a battery pack discharge cycle;

coupling a tank outlet to a battery pack air inlet during said battery pack discharge cycle; and

transferring said oxygen-rich effluent through said tank outlet of said gas tank to said battery pack inlet of said metal-air battery pack during said battery pack discharge cycle.

14. A method of operating a metal-air battery pack mounted within an electric vehicle, the method comprising the steps of:

coupling said metal-air battery pack to an external charging power source via a battery charging system, wherein an oxygen-rich effluent is generated during charging of said metal-air battery pack;

coupling a battery pack air outlet to an ambient air exhaust system;

exhausting said oxygen-rich effluent through said ambient air exhaust system;

determining an oxygen concentration level within a first region corresponding to said electric vehicle;

comparing said oxygen concentration level to a preset oxygen concentration level;

decoupling said battery pack air outlet from said ambient air exhaust system and coupling said battery pack air outlet to a tank inlet of a gas tank mounted within said electric vehicle if said oxygen concentration level exceeds said preset oxygen concentration level, wherein a compressor is interposed between said battery pack outlet and said tank inlet; and

compressing said oxygen-rich effluent passing through said battery pack air outlet with said compressor and storing said oxygen-rich effluent compressed by said compressor within said gas tank.

15. The method of claim 14, further comprising the steps of:

comparing said oxygen concentration level to a second preset oxygen concentration level, wherein if said oxygen concentration level falls below said second preset oxygen concentration level said method further comprises the steps of;

decoupling said battery pack air outlet from said tank inlet;

terminating said compressing and storing steps;

coupling said battery pack air outlet to said ambient air exhaust system; and

exhausting said oxygen-rich effluent through said ambient air exhaust system.

16. The method of claim 15, wherein said second preset oxygen concentration level is less than said preset oxygen concentration level.

17. The method of claim 15, wherein said second preset oxygen concentration level is equivalent to said preset oxygen concentration level.

18. The method of claim 14, further comprising the steps of:

determining a present metal-air battery pack state-of-charge (SOC);

comparing said present metal-air battery pack SOC with a target SOC; and

terminating charging of said metal-air battery pack when said present metal-air battery pack SOC reaches or exceeds said target SOC.

19. The method of claim 14, wherein during a battery pack discharge cycle said method further comprises the steps of:

decoupling said battery pack air outlet from said ambient air exhaust system;

decoupling said battery pack air outlet from said tank inlet; and

opening an ambient air battery pack inlet.

20. The method of claim 14, wherein during a battery pack discharge cycle said method further comprises the steps of:

decoupling said battery pack air outlet from said ambient air exhaust system;

decoupling said battery pack air outlet from said tank inlet;

coupling a tank outlet of said gas tank to a battery pack air inlet; and

transferring said oxygen-rich effluent through said tank outlet of said gas tank to said battery pack inlet of said metal-air battery pack.