BATTERY REMAINING-LIFE ESTIMATION APPARATUS, BATTERY PACK, CAPACITOR, ELECTRIC VEHICLE, AND BATTERY REMAINING-LIFE ESTIMATION METHOD

• US 20150241516A1
• Filed: 02/16/2015
• Published: 08/27/2015
• Est. Priority Date: 02/21/2014
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: HOTTA, Shin
• Granted Patent: US 10,353,010 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• 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 10/48 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 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring 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

Abstract

There is provided a battery remaining-life estimation apparatus that includes a memory, and a circuit. The memory is configured to store information about a polarization-voltage curve of a secondary battery, the information being stored with a correlation with a current value and a temperature of the secondary battery. The circuit is configured to estimate a remaining power of the secondary battery, the remaining power being estimated based on a discharge curve of the secondary battery. The circuit obtains the polarization-voltage curve based on the information in the memory, the polarization-voltage curve being correlated with the current value and the temperature of the secondary battery. The circuit also estimates the discharge curve by subtracting the obtained polarization-voltage curve from an open-circuit voltage curve obtained for the secondary battery.

Claims

1. A battery remaining-life estimation apparatus, comprising:

a memory configured to store information about a polarization-voltage curve of a secondary battery, the information being stored with a correlation with a current value and a temperature of the secondary battery; and

a circuit configured to estimate a remaining power of the secondary battery, the remaining power being estimated based on a discharge curve of the secondary battery, and

the circuit

obtaining the polarization-voltage curve based on the information in the memory, the polarization-voltage curve being correlated with the current value and the temperature of the secondary battery, and

estimating the discharge curve by subtracting the obtained polarization-voltage curve from an open-circuit voltage curve obtained for the secondary battery.

2. The battery remaining-life estimation apparatus according to claim 1, wherein

the memory stores a plurality of typical parameters as the information about the polarization-voltage curve, the parameters defining a shape of the polarization-voltage curve, and

the circuit estimates the polarization-voltage curve based on the typical parameters, the parameters being correlated with the current value and the temperature of the secondary battery.

3. The battery remaining-life estimation apparatus according to claim 2, wherein

for a first curve portion of the polarization-voltage curve where a voltage change responding to a change in amount of charge is small, the memory stores a proportional coefficient and a constant component as the typical parameters, the proportional coefficient being of a component proportional to a discharge current, and

for a second curve portion of the polarization-voltage curve where the voltage change is large, the memory stores a parameter defining a shape of a curve as the typical parameters, the curve being obtained by differentiating the second curve portion with respect to the amount of charge.

4. The battery remaining-life estimation apparatus according to claim 3, wherein

as the parameter defining the shape of the curve obtained by differentiating the second curve portion with respect to the amount of charge, the memory stores a parameter defining a characteristic of the shape of the curve obtained by differentiating the second curve portion with respect to the amount of charge.

5. The battery remaining-life estimation apparatus according to claim 1, wherein

the memory stores the information about the polarization-voltage curve also with a correlation with a capacity retention of the secondary battery.

6. The battery remaining-life estimation apparatus according to claim 1, wherein

the circuit estimates the remaining power based on an estimated temperature change of the secondary battery.

7. The battery remaining-life estimation apparatus according to claim 1, wherein

the circuit obtains the polarization-voltage curve based on current and temperature information of the secondary battery, the information being obtained by communication.

8. A battery pack, comprising:

a secondary battery; and

a battery remaining-life estimation apparatus including

a memory configured to store information about a polarization-voltage curve of the secondary battery, the information being stored with a correlation with a current value and a temperature of the secondary battery, and

a circuit configured to estimate a remaining power of the secondary battery, the remaining power being estimated based on a discharge curve of the secondary battery, and

the circuit

obtaining the polarization-voltage curve based on the information in the memory, the polarization-voltage curve being correlated with the current value and the temperature of the secondary battery, and

estimating the discharge curve by subtracting the obtained polarization-voltage curve from an open-circuit voltage curve obtained for the secondary battery.

9. A capacitor, comprising:

a secondary battery; and

a battery remaining-life estimation apparatus including

a memory configured to store information about a polarization-voltage curve of the secondary battery, the information being stored with a correlation with a current value and a temperature of the secondary battery, and

a circuit configured to estimate a remaining power of the secondary battery, the remaining power being estimated based on a discharge curve of the secondary battery, and

the circuit

obtaining the polarization-voltage curve based on the information in the memory, the polarization-voltage curve being correlated with the current value and the temperature of the secondary battery,

estimating the discharge curve by subtracting the obtained polarization-voltage curve from an open-circuit voltage curve obtained for the secondary battery, and

supplying a power to a connected power consumption device.

10. An electric vehicle, comprising:

a secondary battery;

a battery remaining-life estimation apparatus including

a memory configured to store information about a polarization-voltage curve of the secondary battery, the information being stored with a correlation with a current value and a temperature of the secondary battery, and

a circuit configured to estimate a remaining power of the secondary battery, the remaining power being estimated based on a discharge curve of the secondary battery; and

a transducer configured to convert a power into a driving force for the vehicle, the power being supplied from the secondary battery, and

the circuit

obtaining the polarization-voltage curve based on the information in the memory, the polarization-voltage curve being correlated with the current value and the temperature of the secondary battery, and

estimating the discharge curve by subtracting the obtained polarization-voltage curve from an open-circuit voltage curve obtained for the secondary battery.

11. A battery remaining-life estimation method, comprising:

obtaining a polarization-voltage curve corresponding to a current value and a temperature of a secondary battery based on information thereabout stored in a memory, the information being stored with a correlation with the current value and the temperature of the secondary battery;

estimating a discharge curve of the secondary battery by subtracting the obtained polarization-voltage curve from an open-circuit voltage curve obtained for the secondary battery; and

estimating a remaining power of the secondary battery based on the discharge curve.

12. The battery remaining-life estimation method according to claim 11, wherein

the polarization-voltage curve of the secondary battery is actually measured,

a shape of a curve is linearly approximated, the curve being obtained by differentiating a portion of the actually-measured polarization-voltage curve with respect to an amount of charge, the portion being regarded as being large in voltage change responding to a change in amount of charge, and

a parameter typifying the linearly-approximated shape is stored in the memory as a part of the information about the polarization-voltage curve.

13. The battery remaining-life estimation method according to claim 12, wherein

as the parameter typifying the linearly-approximated shape, a parameter corresponding to an end point or a node in the linearly-approximated shape is stored.