# US 2016/0252586 A1 · Inspection method of secondary battery

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- Number: US 2016/0252586 A1
- Document ID: US20160252586A1
- Status: Published application
- Kind: A1
- Application number: 15/053,525
- Filed: 2016-02-25
- Published: 2016-09-01
- Earliest claimed: 2015-02-27
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Yosuke SHIMURA; Tomohide SUMI; Yoshio MATSUYAMA
- Web page: https://patentgrep.com/patent/US20160252586A1

## CPC

- G01R 31/374: with means for correcting the measurement for temperature or ageing
- G01R 19/16542: {for batteries (charge condition monitoring in G01R31/36)}
- G01R 31/3648: {comprising digital calculation means, e.g. for performing an algorithm}
- G01R 31/3865: {related to manufacture, e.g. testing after manufacture}
- G01R 31/388: involving voltage measurements
- G01R 31/389: Measuring internal impedance, internal conductance or related variables
- H01M 10/446: {Initial charging measures}
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

An inspection method of a secondary battery according to the present invention includes: a charging step of charging an inspection target cell to a predetermined voltage set in advance; a voltage drop amount calculation step of calculating an amount of a voltage drop due to discharge by discharging the inspection target cell at a voltage of not more than the predetermined voltage; a non-defective product determination step of determining that the inspection target cell is a non-defective product, when the voltage drop amount is a threshold or less; and an aging step of performing aging after the non-defective product determination step.

## Claims

### Claim 1

An inspection method of a secondary battery, comprising:
a charging step of charging an inspection target cell to a predetermined voltage set in advance;
a voltage drop amount calculation step of calculating an amount of a voltage drop due to discharge by discharging the inspection target cell at a voltage of not more than the predetermined voltage;
a non-defective product determination step of determining that the inspection target cell is a non-defective product, when the voltage drop amount is a threshold or less; and
an aging step of performing aging after the non-defective product determination step.

### Claim 2 (depends on 1)

The inspection method according to claim 1, further comprising:
an inspection target value calculation step of calculating a value of an inspection target item of the inspection target cell, the value being obtained by performing a multiple regression analysis by use of the voltage drop amount and at least one of an aging temperature and an aging time,
wherein, in the non-defective product determination step, it is determined that the inspection target cell is the non-defective product when the calculated value of the inspection target item falls within a standard range.

### Claim 3 (depends on 1)

The inspection method according to claim 1, wherein:
the predetermined voltage is determined based on a voltage of the secondary battery at which a correlation coefficient between a low-temperature output of the secondary battery and the voltage drop amount is 0.8 or more, or a state of charge of the secondary battery at which the correlation coefficient between the low-temperature output of the secondary battery and the voltage drop amount is 0.7 or more.

### Claim 4 (depends on 1)

The inspection method according to claim 1, wherein
in the aging step, a temperature control is performed so that a temperature difference between a plurality of inspection target cells falls within a temperature range set in advance.

### Claim 5 (depends on 4)

The inspection method according to claim 4, wherein
the temperature range is set within a range from −3° C. to +3° C. relative to a reference temperature.

### Claim 6 (depends on 1)

The inspection method according to claim 1, further comprising:
a capacity check step of checking a capacity of the secondary battery performed between the non-defective product determination step and the aging step.