Charge Rate Modulation of Metal-Air Cells as a Function of Ambient Oxygen Concentration

• US 20120041622A1
• Filed: 09/22/2010
• Published: 02/16/2012
• 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, Beck, David G.
• Granted Patent: US 8,423,215 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/14 Acceleration
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2250/12 by confirmation, e.g. of the input
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0061 relating to electrical machines
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/20 : having different nominal voltages
• CPC Class Codes: B60L 58/21 : having the same nominal voltage
• CPC Class Codes: B60L 58/24 : for controlling the temperature of batteries
• CPC Class Codes: B60L 58/26 : by cooling
• CPC Class Codes: B60L 58/27 : by heating
• CPC Class Codes: H01M 10/0525 : Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/30 : Nickel accumulators H01M10/34 takes precedence
• CPC Class Codes: H01M 10/32 : Silver accumulators H01M10/34 takes precedence
• CPC Class Codes: H01M 10/345 : Gastight metal hydride accumulators
• CPC Class Codes: H01M 10/443 : in response to temperature
• CPC Class Codes: H01M 10/486 : for measuring temperature
• CPC Class Codes: H01M 10/613 : Cooling or keeping cold
• CPC Class Codes: H01M 10/633 : characterised by algorithms, flow charts, software details or the like
• CPC Class Codes: H01M 10/6561 : Gases
• CPC Class Codes: H01M 10/6567 : Liquids
• CPC Class Codes: H01M 12/06 : with one metallic and one gaseous electrode
• 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 16/00 : Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 16/006 : of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2200/10 : Temperature sensitive devices
• CPC Class Codes: H01M 2200/20 : Pressure-sensitive devices
• CPC Class Codes: H01M 2220/20 : Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 50/204 : Racks, modules or packs for multiple batteries or multiple cells
• CPC Class Codes: H01M 50/253 : adapted for specific cells, e.g. electrochemical cells operating at high temperature
• CPC Class Codes: H01M 50/317 : Re-sealable arrangements
• CPC Class Codes: H01M 50/375 : Vent means sensitive to or responsive to temperature
• CPC Class Codes: H02J 7/0029 : with safety or protection devices or circuits
• CPC Class Codes: H02J 7/14 : for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

A system and method for charging a metal-air battery pack at the maximum possible rate while maintaining an ambient oxygen concentration below a preset concentration is provided, thereby minimizing the risks associated with generating oxygen during the charging cycle.

Claims

1. An electric vehicle battery charging system, comprising:

a battery pack, wherein said battery pack is configured for use within an electric vehicle and to provide power to said electric vehicle, and wherein said battery pack is comprised of at least one metal-air cell;

at least one oxygen concentration sensor;

a charging 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 charging 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 charging system controller is configured to set battery pack charging conditions based on said oxygen concentration level, wherein said battery pack charging conditions include suspension of charging system operation when said oxygen concentration level exceeds a preset level and resumption of charging system operation when said oxygen concentration level falls below said preset level; and

a battery pack charging system coupleable to said battery pack and to an external power source, wherein said battery pack charging system charges said battery pack in accordance with said battery pack charging conditions set by said charging system controller.

2. The electric vehicle battery charging system of claim 1, wherein said at least one oxygen sensor is mounted proximate to an oxygen outlet corresponding to said battery pack.

3. The electric vehicle battery charging system of claim 1, wherein said at least one oxygen sensor is mounted proximate to an oxygen inlet corresponding to said battery pack.

4. The electric vehicle battery charging system of claim 1, wherein said at least one oxygen sensor is mounted within a passenger compartment corresponding to said electric vehicle.

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

6. The electric vehicle battery charging system of claim 1, wherein said at least one oxygen sensor is mounted at a location within an electric vehicle charging bay, and wherein said location is external to said electric vehicle, and wherein said at least one oxygen sensor is detachably coupleable to said charging system controller and monitors an external vehicle environment.

7. The electric vehicle battery charging system of claim 1, wherein said battery pack charging conditions set by said charging system controller further include a plurality of charge rates, wherein said charging system controller selects one of said plurality of charge rates based on said oxygen concentration level for use by said battery pack charging system during charging of said battery pack.

8. The electric vehicle battery charging system of claim 1, further comprising a warning system coupled to and controlled by said charging system controller, wherein said warning system is activated by said charging system controller when said oxygen concentration exceeds said preset level.

9. The electric vehicle battery charging system of claim 8, wherein said warning system is comprised of at least one of a visual warning system, an auditory warning system, an automated text messaging system, and an automated telephone calling system.

10. The electric vehicle battery charging system of claim 1, wherein said charging system controller and said battery pack charging system are mounted within said electric vehicle.

11. The electric vehicle battery charging 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 charging system controller terminates operation of said battery pack charging system when said SOC for said battery pack reaches a target SOC level.

12. The electric vehicle battery charging system of claim 1, further comprising:

means for determining a set of initial charging conditions;

means for determining a charging location; and

a memory for storing at least one charging profile.

13. The electric vehicle battery charging system of claim 12, wherein said means for determining said set of initial charging conditions includes at least one of a battery temperature sensor, an ambient environment temperature sensor, and a state-of-charge (SOC) detection system.

14. The electric vehicle battery charging system of claim 12, wherein said means for determining said charging location includes at least one of a user input interface and a GPS system.

15. The electric vehicle battery charging system of claim 12, wherein said battery pack charging conditions set by said charging system controller and used by said battery pack charging system includes one of said at least one charging profile.

16. A method of charging 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;

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;

initiating charging of said metal-air battery pack if said oxygen concentration level is less than said 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.

17. The method of claim 16, 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.

18. The method of claim 16, further comprising the steps of:

comparing said oxygen concentration level to a second preset oxygen concentration level, wherein said second preset oxygen concentration level is lower than said preset oxygen concentration level;

charging said metal-air battery pack at a first charge rate if said oxygen concentration level is less than said second preset oxygen concentration level; and

charging said metal-air battery pack at a second charge rate if said oxygen concentration level is greater than said second preset oxygen concentration level and less than said preset oxygen concentration level.

19. The method of claim 16, further comprising the step of activating an auditory warning system if said oxygen concentration level exceeds said preset oxygen concentration level.

20. The method of claim 16, further comprising the step of activating a visual warning system if said oxygen concentration level exceeds said preset oxygen concentration level.

21. The method of claim 16, further comprising the step of activating a notification warning system if said oxygen concentration level exceeds said preset oxygen concentration level.

22. The method of claim 16, further comprising the steps of:

determining a second oxygen concentration level corresponding to a second region, wherein said first region corresponds to a metal-air battery pack oxygen outlet and said second region corresponds to an external vehicle sensing location;

comparing said second oxygen concentration level to said preset oxygen concentration level; and

suspending charging of said metal-air battery pack if said second oxygen concentration level exceeds said preset oxygen concentration level.

23. The method of claim 16, further comprising the steps of:

determining a second oxygen concentration level corresponding to a second region, wherein said first region corresponds to a metal-air battery pack oxygen outlet and said second region corresponds to an external vehicle sensing location;

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

suspending charging of said metal-air battery pack if said second oxygen concentration level exceeds said second preset oxygen concentration level.

24. The method of claim 23, wherein said second preset oxygen concentration level is less than said preset oxygen concentration level.

25. The method of claim 16, wherein said step of determining said oxygen concentration level within said first region further comprises the steps of monitoring a plurality of oxygen concentration levels at a plurality of locations and averaging said plurality of oxygen concentration levels to obtain said oxygen concentration level.

26. The method of claim 16, wherein said step of initiating charging of said metal-air battery pack further comprises the step of applying a charging profile.

27. The method of claim 26, further comprising the step of determining a set of initial charging conditions, wherein said step of applying said charging profile further comprises the step of selecting said charging profile from a plurality of stored charging profiles based on said set of initial charging conditions.