DIFFUSION-LIMITED ADAPTIVE BATTERY CHARGING

• US 20160087461A1
• Filed: 06/22/2015
• Published: 03/24/2016
• Est. Priority Date: 04/11/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Greening, Thomas C., Athas, William C., Ungar, P. Jeffrey
• Granted Patent: US 10,044,210 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01P 15/00 Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
• CPC Class Codes: G01P 3/56 for comparing two speeds
• 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 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 2300/00 Electrolytes
• CPC Class Codes: H01M 50/00 Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• 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 governed by diffusion, an electrolyte separator and a non-transport-limiting electrode. During operation, the system determines a lithium surface concentration at an interface between the transport-limiting electrode and the electrolyte separator based on a diffusion time for lithium in the transport-limiting electrode. Next, the system calculates a charging current or a charging voltage for the battery based on the determined lithium surface concentration. Finally, the system applies the charging current or the charging voltage to the battery.

Claims

1-17. -17. (canceled)

18. A mechanism for charging a battery, the mechanism comprising:

a controller;

a voltage sensor and a current sensor coupled to the controller, and each coupleable to a battery having a first electrode, a second electrode, and at least one interface therebetween; and

at least one of a current source and a voltage source, each coupled to the controller and coupleable to the battery,

wherein the controller is configured to;

receive voltage information from the voltage sensor;

receive current information from the current sensor; and

control, based at least in part on the received voltage information and current information following a prior charging event, at least one of the current source and the voltage source to charge the battery.

19. The mechanism for charging a battery of claim 18, wherein the controller is further configured to:

determine a concentration of lithium at the interface, based at least in part, on the received voltage information and the received current information, wherein determining the concentration of lithium at the interface involves determining a potential of at least one of the first electrode and the second electrode with respect to a predetermined reference; and

control at least one of the current source and the voltage source to charge the battery, further based on the determined concentration of lithium at the interface.

20. The mechanism for charging a battery of claim 18, the mechanism further comprising:

a temperature sensor coupled to the controller and coupleable to the battery,

wherein the controller is further configured to;

receive temperature information from the temperature sensor; and

control, further based at least in part on the received temperature following a prior charging event, at least one of the current source and the voltage source to charge the battery.

21. The mechanism for charging a battery of claim 20, wherein the controller is further configured to:

determine a concentration of lithium at the interface, further based at least in part, on the received temperature information, wherein determining the concentration of lithium at the interface involves determining a potential of at least one of the first electrode and the second electrode with respect to a predetermined reference; and

control at least one of the current source and the voltage source to charge the battery, further based on the determined concentration of lithium at the interface.

22. The mechanism for charging a battery of claim 20, the mechanism further comprising:

a state of charge estimator, the state of charge estimator coupled to the voltage sensor, the current sensor, the temperature sensor and the controller,

wherein the state of charge estimator is configured to;

receive voltage information from the voltage sensor;

receive current information from the current sensor;

receive temperature information from the temperature sensor;

following a prior charging event, estimate a state of charge based on at least two of the received voltage information, the received current information and the received temperature information; and

generate state of charge information corresponding to the estimated state of charge; and

the controller is further configured to;

receive the state of charge information from the state of charge estimator; and

control, further based on the received state of charge information, at least one of the current source and the voltage source to charge the battery.

23. The mechanism for charging a battery of claim 22, wherein the controller is further configured to:

determine a concentration of lithium at the interface, further based at least in part, on the received state of charge information, wherein determining the concentration of lithium at the interface involves determining a potential of at least one of the first electrode and the second electrode with respect to a predetermined reference; and

control at least one of the current source and the voltage source to charge the battery, further based on the determined concentration of lithium at the interface.

24. The mechanism for charging a battery of claim 22, wherein the voltage sensor is a voltmeter, the current sensor is a current meter, and the temperature sensor is a thermal sensor.

25. A controller for a battery charger including a current source and a voltage source, the controller configured to:

receive voltage information from a voltage sensor after a prior charging event;

receive current information from a current sensor after the prior charging event;

control, based at least in part on the received voltage information and the received current information, at least one of the current source and the voltage source to charge the battery.

26. The controller of claim 25, the controller further configured to:

determine a concentration of lithium at an interface between two electrodes of a battery, based at least in part, on the received voltage information and the received current information, wherein determining the concentration of lithium at the interface involves determining a potential of at least one of the electrodes with respect to a predetermined reference

further control, based at least in part on the determined lithium concentration at the interface, at least one of the current source and the voltage source to charge the battery.

27. The controller of claim 25, the controller further configured to:

receive temperature information from a temperature sensor after a prior charging event; and

control, further based at least in part on the received temperature information, at least one of the current source and the voltage source to charge the battery.

28. The controller of claim 27, the controller further configured to:

determine the concentration of lithium at the interface, further based on the received temperature information, wherein determining the concentration of lithium at the interface involves determining a potential of at least one of the electrodes with respect to a predetermined reference; and

control, further based at least in part on the determined concentration of lithium at the interface, at least one of the current source and the voltage source to charge the battery.

29. The controller of claim 27, wherein the voltage sensor is a voltmeter, the current sensor is a current meter, and the temperature sensor is a thermal sensor.

30. The controller of claim 27, the controller further configured to:

receive state of charge information from a state of charge estimator after a prior charging event; and

control, further based at least in part on the received state of charge information, at least one of the current source and the voltage source to charge the battery.

31. The controller of claim 30, the controller further configured to:

determine the concentration of lithium at the interface, further based on the received state of charge information, wherein determining the concentration of lithium at the interface further involves determining a potential of at least one of the electrodes with respect to a predetermined reference; and

control, further based at least in part on the determined concentration of lithium at the interface, at least one of the current source and the voltage source to charge the battery.

32. A non-transitory computer readable storage medium storing instructions which, when executed by a controller, cause the controller to:

receive voltage information from a voltage sensor following a prior charging event;

receive current information from a current sensor following the prior charging event; and

control, based at least in part on the received voltage information and the received current information, at least one of a current source and a voltage source to charge the battery.

33. The non-transitory computer readable storage medium of claim 32, further storing instructions which, when executed by the controller, cause the controller to:

determine a concentration of lithium at an interface between two electrodes of a battery, based at least in part, on the received voltage information and the received current information, wherein determining the concentration of lithium at the interface involves determining a potential of at least one of the electrodes with respect to a predetermined reference; and

control, further based at least in part on the determined lithium concentration, at least one of a current source and a voltage source to charge the battery.

34. The non-transitory computer readable storage medium of claim 32, further storing instructions which, when executed by the controller, cause the controller to:

receive temperature information from a temperature sensor following the prior charging event; and

control, further based at least in part on the received temperature information, at least one of a current source and a voltage source to charge the battery.

35. The non-transitory computer readable storage medium of claim 34, further storing instructions which, when executed by the controller, cause the controller to:

determine the concentration of lithium at the interface, further based on the received temperature information, wherein determining the concentration of lithium at the interface involves determining a potential of at least one of the electrodes with respect to a predetermined reference; and

control, further based at least in part on the determined concentration of lithium at the interface, at least one of a current source and a voltage source to charge the battery.

36. The non-transitory computer readable storage medium of claim 34, wherein the voltage sensor is a voltmeter, the current sensor is a current meter, and the temperature sensor is a thermal sensor.

37. The non-transitory computer readable storage medium of claim 34, further storing instructions which, when executed by the controller, cause the controller to:

receive state of charge information from a state of charge estimator after a prior charging event; and

control, further based at least in part on the received state of charge information, at least one of a current source and a voltage source to charge the battery.

38. The non-transitory computer readable storage medium of claim 37, further storing instructions which, when executed by the controller, cause the controller to:

determine the concentration of lithium at the interface, further based on the received state of charge information, wherein determining the concentration of lithium at the interface further involves determining a potential of at least one of the electrodes with respect to a predetermined reference; and

control, further based at least in part on the determined concentration of lithium at the interface, at least one of a current source and a voltage source to charge the battery.