ADAPTIVE SURFACE CONCENTRATION BATTERY CHARGING

• US 20090259420A1
• Filed: 09/30/2008
• Published: 10/15/2009
• Est. Priority Date: 04/11/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Ungar, P. Jeffrey, Athas, William C., Greening, Thomas C.
• Granted Patent: US 9,331,513 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• 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 10/0566 Liquid materials
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/5815 Sulfides
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Some embodiments of the present invention provide a system that adaptively charges a battery, wherein the battery is a lithium-ion battery which includes a transport-limiting electrode, an electrolyte separator and a non-transport-limiting electrode. To charge the battery, the system first determines a lithium surface concentration at an interface between the transport-limiting electrode and the electrolyte separator. Next, the system uses the determined lithium surface concentration to control a charging process for the battery so that the charging process maintains the lithium surface concentration within set limits.

Claims

9. A method for adaptively charging a battery, the method comprising:

determining a potential of an electrode in the battery with respect to a known reference; and

using the determined potential to charge the battery in a manner that maintains a lithium surface concentration at an interface between the electrode and an electrolyte separator within set limits.

10. The method of claim 9, wherein using the determined potential to charge the battery involves using the determined potential to adjust either a charging voltage or a charging current to maintain the potential of the electrode at a level which keeps the lithium surface concentration within the set limits.

11. The method of claim 9, wherein determining the potential of the electrode involves directly measuring the potential of the electrode.

12. The method of claim 9, wherein determining the potential of the electrode involves:

determining a state of charge for the battery; and

determining the potential of the electrode from the determined state of charge and other parameters related to the battery.

13. The method of claim 9, wherein determining the potential of the electrode involves:

monitoring a temperature of the battery;

monitoring a current through the battery;

monitoring a total cell voltage of the battery; and

determining the potential of the electrode based on the monitored temperature, current and total cell voltage.

14. The method of claim 9,

wherein the electrode is a transport-limiting electrode;

and

wherein the battery also includes a non-transport-limiting electrode.

15. A method for adaptively charging a battery, wherein the battery is a lithium-ion battery, the method comprising:

monitoring a current through the battery;

monitoring a voltage of the battery; and

using the monitored current and voltage to control a charging process for the battery so that the charging process maintains a lithium surface concentration at an interface between an electrode and an electrolyte separator in the battery within set limits.

16. The method of claim 15,

wherein the method further comprises monitoring a temperature of the battery;

and

wherein controlling the charging process involves using the monitored temperature in addition to the monitored current and voltage to control the charging process.

17. A computer-readable storage medium storing instructions that when executed by a controller for a battery cause the controller to perform a method for adaptively charging a battery, wherein the battery is a lithium-ion battery, the method comprising:

determining a lithium surface concentration at an interface between an electrode and an electrolyte separator in the battery; and

using the determined lithium surface concentration to control a charging process for the battery so that the charging process maintains the lithium surface concentration within set limits.

18. A computer-readable storage medium storing instructions that when executed by a controller for a battery cause the controller to perform a method for adaptively charging a battery, wherein the battery is a lithium-ion battery, the method comprising:

determining a potential of an electrode in the battery with respect to a known reference; and

using the determined potential to charge the battery in a manner that maintains a lithium surface concentration at an interface between the electrode and an electrolyte separator within set limits.

19. The computer-readable storage medium of claim 18, wherein using the determined potential to charge the battery involves using the determined potential to adjust either a charging voltage or a charging current to maintain the potential of the electrode at a level which keeps the lithium surface concentration within the set limits.

20. A computer-readable storage medium storing instructions that when executed by a controller for a battery cause the controller to perform a method for adaptively charging a battery, wherein the battery is a lithium-ion battery, the method comprising:

monitoring a current through the battery;

monitoring a voltage of the battery; and

using the monitored current and voltage to control a charging process for the battery so that the charging process maintains a lithium surface concentration at an interface between an electrode and an electrolyte separator in the battery within set limits.

21. The computer-readable storage medium of claim 20,

wherein the method further comprises monitoring a temperature of the battery;

and

wherein controlling the charging process involves using the monitored temperature in addition to the monitored current and voltage to control the charging process.

22. A battery with an adaptive charging mechanism, comprising:

a first electrode;

an electrolyte separator;

a second electrode;

a voltage sensor configured to measure a voltage for the battery;

a charging source configured to apply a charging current or a charging voltage to the battery;

a controller configured to receive an input from the voltage sensor and to send a control signal to the charging source;

wherein the controller is configured to,

determine a lithium surface concentration at an interface between the first electrode and the electrolyte separator, and

use the determined lithium surface concentration to control a charging process for the battery so that the charging process maintains the lithium surface concentration within set limits.

1. A method for adaptively charging a battery, wherein the battery is a lithium-ion battery, the method comprising:

determining a lithium surface concentration at an interface between an electrode and an electrolyte separator in the battery; and

using the determined lithium surface concentration to control a charging process for the battery so that the charging process maintains the lithium surface concentration within set limits.

2. The method of claim 1,

wherein determining the lithium surface concentration involves determining a potential of the electrode with respect to a known reference, wherein the potential is correlated with the lithium surface concentration;

and

wherein using the determined lithium surface concentration to control the charging process involves using the determined potential of the electrode to adjust either a charging voltage or a charging current, to maintain the potential of the electrode at a level which keeps the lithium surface concentration within the set limits.

3. The method of claim 2, wherein maintaining the potential of the electrode involves maintaining either a maximum potential or a minimum potential which keeps the lithium surface concentration within the set limits.

4. The method of claim 2, wherein determining the potential of the electrode involves directly measuring the potential of the electrode.

5. The method of claim 2, wherein determining the potential the electrode involves:

determining a state of charge for the battery; and

determining the potential of the electrode from the determined state of charge and other parameters related to the battery.

6. The method of claim 2,

wherein the electrode is a transport-limiting electrode;

and

wherein the battery also includes a non-transport-limiting electrode.

7. The method of claim 6,

wherein the transport-limiting electrode is a negative electrode;

and

wherein the non-transport-limiting electrode is a positive electrode.

8. The method of claim 7,

wherein the negative electrode is comprised of graphite and/or TiS₂;

wherein the electrolyte separator is a liquid electrolyte comprised of LiPF₆, LiBF₄ and/or LiClO₄ and an organic solvent; and

wherein the positive electrode is comprised of LiCoO₂, LiMnO₂, LiFePO₄ and/or Li₂FePO₄F.

23. The battery of claim 22,

wherein while determining the lithium surface concentration, the controller is configured to determine a potential of the first electrode with respect to a known reference, wherein the potential is correlated with the lithium surface concentration;

and

wherein while using the determined lithium surface concentration to control the charging process, the controller is configured to use the determined potential of the first electrode to adjust either a charging voltage or a charging current to maintain the potential of the first electrode at a level which keeps the lithium surface concentration within the set limits.

24. The battery of claim 23, wherein while maintaining the potential of the first electrode, the controller is configured to maintain either a minimum or a maximum potential which keeps the lithium surface concentration within the set limits.

25. The battery of claim 23, wherein while determining the potential of the first electrode, the controller is configured to use the voltage sensor to directly measure the potential of the first electrode.

26. The battery of claim 23, wherein while determining the potential of the first electrode, the controller is configured to:

determine a state of charge for the battery; and

determine the potential of the first electrode from the determined state of charge and other parameters related to the battery.

27. The battery of claim 26,

wherein the transport-limiting electrode is a negative electrode;

and

wherein the non-transport-limiting electrode is a positive electrode.

28. The battery of claim 27,

wherein the negative electrode is comprised of graphite and/or TiS₂;

wherein the electrolyte separator is a liquid electrolyte comprised of LiPF₆, LiBF₄ and/or LiClO₄ and an organic solvent; and

wherein the positive electrode is comprised of LiCoO₂, LiMnO₂, LiFePO₄ and/or Li₂FePO₄F.

26-1. The battery of claim 23,

wherein the first electrode is a transport-limiting electrode;

and

wherein the second electrode is a non-transport-limiting electrode.

30. A battery with an adaptive charging mechanism, comprising:

a first electrode;

an electrolyte separator;

a second electrode;

a voltage sensor configured to measure a voltage for the battery;

a charging source configured to apply a charging current or a charging voltage to the battery;

a controller configured to receive an input from the voltage sensor, and to send a control signal to the charging source;

wherein the controller is configured to,

determine a potential of the first electrode with respect to a known reference, and

use the determined potential to charge the battery in a manner that maintains a lithium surface concentration at an interface between the first electrode and the electrolyte separator within set limits.

31. The battery of claim 30, wherein while using the determined potential to charge the battery, the controller is configured to use the determined potential to adjust either a charging voltage or a charging current to maintain the potential of the first electrode at a level which keeps the lithium surface concentration within the set limits.

32. The battery of claim 30, wherein while determining the potential of the first electrode, the controller is configured to use the voltage sensor to directly measure the potential of the first electrode.

33. The battery of claim 30,

wherein the battery includes a thermal sensor configured to measure a temperature of the battery;

wherein the battery includes a current sensor configured to measure a charging current for the battery;

wherein while determining the potential of the first electrode, the controller is configured to;

use the thermal sensor to monitor a temperature of the battery,

use the current sensor to monitor a current through the battery,

use the voltage sensor to monitor a total cell voltage of the battery, and

determine the potential of the first electrode based on the monitored temperature, current and total cell voltage.

34. A battery with an adaptive charging mechanism, comprising:

a first electrode;

an electrolyte separator;

a second electrode;

a voltage sensor configured to measure a voltage for the battery;

a charging source configured to apply a charging current or a charging voltage to the battery;

a controller configured to receive an input from the voltage sensor, and to send a control signal to the charging source;

wherein the controller is configured to;

determine a potential of the first electrode with respect to a known reference; and

use the determined potential to charge the battery in a manner that maintains a lithium surface concentration at an interface between the first electrode and the electrolyte separator within set limits.

35. A battery with an adaptive charging mechanism, the battery comprising:

a first electrode;

an electrolyte separator;

a second electrode;

a voltage sensor configured to measure a voltage for the battery;

a current sensor configured to measure a charging current for the battery

a charging source configured to apply a charging current or a charging voltage to the battery;

a controller configured to receive inputs from the voltage sensor and the current sensor and to send a control signal to the charging source;

wherein the controller is configured to;

use the current sensor to monitor a current through the battery;

use the voltage sensor to monitor a voltage of the battery; and

use the monitored current and voltage to control a charging process for the battery so that the charging process maintains a lithium surface concentration at an interface between the first electrode and the electrolyte separator within set limits.

36. The battery of claim 35,

wherein the battery further comprises a thermal sensor configured to measure a temperature of the battery;

and

wherein the controller is configured to;

use the thermal sensor to monitor a temperature of the battery; and

use monitored temperature in addition to the monitored current and

voltage to control the charging process.