Lithium-ion battery controlling apparatus and electric vehicle

• US 8,305,085 B2
• Filed: 09/30/2011
• Issued: 11/06/2012
• Est. Priority Date: 10/12/2010
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Maruno, Naoki, Kawabuchi, Yuuji
• Primary Examiner(s): Fantu, Yalkew
• Application Number:
  US13/249,860
• Publication Number:
  US 20120086368A1
• Time in Patent Office: 403 Days
• Field of Search: 324/433
• US Class Current: 324/433
• 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 2240/549 Current
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• 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

Abstract

A lithium-ion battery controlling apparatus includes a controller. The controller is configured to raise an upper-limit voltage in response to capacity degradation of a lithium-ion battery which is configured to supply power to a load and receive power from the load.

Claims

1. A lithium-ion battery controlling apparatus comprising:

a controller configured to raise an upper-limit voltage of a lithium-ion battery by increasing a potential of a positive electrode of the lithium-ion battery in response to capacity degradation occurring at a negative electrode of the lithium-ion battery, wherein the capacity degradation is defined as an increase in internal resistance within the lithium-ion battery over time that results in a reduction in charge storage capacity of the lithium-ion battery when measured by charging the lithium-ion battery at a same charging voltage for a same length of time, and wherein the lithium ion battery is configured to supply power to a load and receive power from the load.

2. The lithium-ion battery controlling apparatus according to claim 1, wherein the controller is configured to estimate a degradation state at or below a temperature at which mobility of an electrolyte of the lithium-ion battery is lowered.

3. The lithium-ion battery controlling apparatus according to claim 2, wherein the controller raises the upper-limit voltage at or below 0°

C.

4. The lithium-ion battery controlling apparatus according to claim 2, wherein the controller raises the upper-limit voltage when a lithium electrodeposition voltage is less than or equal to an upper-limit open circuit voltage.

5. The lithium-ion battery controlling apparatus according to claim 1, wherein the controller is configured to determine occurrence of the capacity degradation of the lithium-ion battery by detecting the internal resistance of the lithium-ion battery.

6. The lithium-ion battery controlling apparatus according to claim 1, wherein the load is a motor, and

the controller is configured to calculate the upper-limit voltage in accordance with the capacity degradation, to compare a voltage of the lithium-ion battery with the upper-limit voltage, and to give a charging-output limiting command in accordance with a result of the comparison.

7. The lithium-ion battery controlling apparatus according to claim 6, wherein the lithium-ion battery is a battery for vehicles.

9. The lithium-ion battery controlling apparatus according to claim 1, wherein the upper-limit voltage is a maximum voltage applied to the lithium-ion battery during charging of the lithium-ion battery.

8. An electric vehicle comprising:

a motor;

a lithium-ion battery configured to supply power to the motor and receive power from the motor;

a degradation detector configured to detect or estimate a degree of degradation of the lithium-ion battery; and

an upper-limit voltage controller configured to raise an upper-limit voltage of the lithium-ion battery during regeneration in accordance with the degree of degradation of the lithium-ion battery,

wherein the degree of degradation is defined as an increase in internal resistance within the lithium-ion battery over time that results in a reduction in charge storage capacity of the lithium-ion battery when measured by charging the lithium-ion battery at a same charging voltage for a same length of time.

10. The electric vehicle according to claim 8, wherein the upper-limit voltage is a maximum voltage applied to the lithium-ion battery during charging of the lithium-ion battery.