Battery diagnosis apparatus, battery diagnosis method and battery diagnosis system

Patent metadata

Field	Value
Publication number	US-12405314-B2
Application number	US-202318876648-A
Country	US
Kind code	B2
Filing date	Jun 9, 2023
Priority date	Jun 20, 2022
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A battery diagnosis apparatus, a battery diagnosis method and a battery diagnosis system are disclosed. The battery diagnosis apparatus includes a data acquisition unit configured to acquire battery information indicating a time-dependent change history of a terminal voltage and a charge current of a battery during a reference number of charge cycles performed according to a Constant Current (CC)-Constant Voltage (CV) charging protocol for the battery at beginning of life (BOL). The apparatus also includes a control unit configured to calculate an initial CC capacity ratio for each charge cycle of the reference number of charge cycles performed based on the battery information. A first initial CC capacity ratio in a first charge cycle is a ratio of a first CC charge capacity to a total charge capacity of the battery in the first charge cycle, and the first CC charge capacity is a charge capacity in a first CC charging duration according to the CC-CV charging protocol. The control unit is configured to determine a representative initial CC capacity ratio based on each initial CC capacity ratio of each charge cycle of the reference number of charge cycles; an diagnose the battery by determining an indication of accelerated degradation by comparing the representative initial CC capacity ratio with a predetermined representative reference CC capacity ratio.

First claim

What is claimed is:

1. A battery diagnosis apparatus, comprising:
a data acquisition unit configured to acquire battery information indicating a time-dependent change history of a terminal voltage and a charge current of a battery for each charge cycle performed a reference number of times for the battery at beginning of life (BOL) according to a Constant Current (CC)-Constant Voltage (CV) charging protocol; and
a control unit configured to calculate an initial CC capacity ratio for each charge cycle performed the reference number of times based on the battery information,
wherein the initial CC capacity ratio in a specific charge cycle is a ratio of a CC charge capacity to a total charge capacity of the battery in the specific charge cycle, and the CC charge capacity is a charge capacity in a CC charging duration according to the CC-CV charging protocol, and
wherein the control unit is configured to:
determine a representative initial CC capacity ratio based on the initial CC capacity ratio for each charge cycle, and
diagnose whether the battery has sign of accelerated degradation by comparing the representative initial CC capacity ratio with a predetermined representative reference CC capacity ratio.

2. The battery diagnosis apparatus according to claim 1 , wherein the control unit is configured to diagnose that the battery has sign of accelerated degradation when the representative initial CC capacity ratio is larger than the predetermined representative reference CC capacity ratio.

3. The battery diagnosis apparatus according to claim 1 , wherein the control unit is configured to adjust a cut-off voltage of the CC-CV charging protocol in response to the battery being diagnosed to have sign of accelerated degradation, and
wherein the cut-off voltage is a voltage which is a reference for a change event from a CC charging stage to a CV charging stage.

4. The battery diagnosis apparatus according to claim 3 , wherein the control unit is configured to:
in response to the battery being diagnosed to have sign of accelerated degradation, calculate a capacity ratio deviation indicating a difference between the representative initial CC capacity ratio and the representative reference CC capacity ratio, and
adjust the cut-off voltage based on the capacity ratio deviation.

5. The battery diagnosis apparatus according to claim 4 , wherein the control unit is configured to:
determine a target SOC based on a reference State Of Charge (SOC) and the capacity ratio deviation, wherein the reference SOC is mapped to a reference cut-off voltage recorded in a predetermined reference SOC profile indicating a correlation between SOC and Closed Circuit Voltage (CCV), and
adjust the cut-off voltage to be equal to the CCV mapped to the target SOC in the reference SOC profile.

6. The battery diagnosis apparatus according to claim 5 , wherein the control unit is configured to determine the target SOC by subtracting the capacity ratio deviation from the reference SOC.

7. The battery diagnosis apparatus according to claim 1 , wherein the control unit is configured to calculate the representative initial CC capacity ratio to be equal to an average or a median of a same number of initial CC capacity ratios as the reference number when the reference number is 2 or greater.

8. The battery diagnosis apparatus according to claim 1 , wherein the control unit is configured to, for each charge cycle,
determine the CC charge capacity by accumulating a current value of the charge current for the CC charging duration according to the CC-CV charging protocol,
determine a CV charge capacity by accumulating a current value of the charge current for a CV charging duration according to the CC-CV charging protocol, and
determine the total charge capacity by summing the CC charge capacity and the CV charge capacity.

9. The battery diagnosis apparatus according to claim 1 , wherein the control unit is configured to:
in response to the battery being diagnosed to have sign of accelerated degradation, calculate a capacity ratio deviation indicating a difference between the representative initial CC capacity ratio and the representative reference CC capacity ratio,
select any one voltage adjustment scheduling curve associated with the calculated capacity ratio deviation from a plurality of preset voltage adjustment scheduling curves associated with a plurality of capacity ratio deviations in a one-to-one relationship, wherein each voltage adjustment scheduling curve defines a change in voltage adjustment value with increasing cycle count, and
determine the cut-off voltage of the CC-CV charging protocol using the selected voltage adjustment scheduling curve each time the cycle count of the charge cycle increases, and
wherein the cut-off voltage is a voltage which is a reference for a change event from a CC charging stage to a CV charging stage.

10. A battery diagnosis system comprising the battery diagnosis apparatus according to claim 1 .

11. A battery diagnosis method, comprising:
acquiring battery information indicating a time-dependent change history of a terminal voltage and a charge current of a battery for each charge cycle performed a reference number of times for the battery at beginning of life (BOL) according to a Constant Current (CC)-Constant Voltage (CV) charging protocol;
calculating an initial CC capacity ratio for each charge cycle performed the reference number of times based on the battery information, wherein the initial CC capacity ratio in a specific charge cycle is a ratio of a CC charge capacity to a total charge capacity of the battery in the specific charge cycle, and the CC charge capacity is a charge capacity in a CC charging duration according to the CC-CV charging protocol;
determining a representative initial CC capacity ratio based on the initial CC capacity ratio for each charge cycle; and
diagnosing whether the battery has sign of accelerated degradation by comparing the representative initial CC capacity ratio with a predetermined representative reference CC capacity ratio.

12. The battery diagnosis method according to claim 11 , wherein the diagnosing whether the battery has sign of accelerated degradation comprises diagnosing that the battery has sign of accelerated degradation when the representative initial CC capacity ratio is larger than the predetermined representative reference CC capacity ratio.

13. The battery diagnosis method according to claim 11 , further comprising:
adjusting a cut-off voltage of the CC-CV charging protocol in response to the battery being diagnosed to have sign of accelerated degradation,
wherein the cut-off voltage is a voltage which is a reference for a change event from a CC charging stage to a CV charging stage.

14. The battery diagnosis method according to claim 13 , wherein the adjusting of the cut-off voltage of the CC-CV charging protocol comprises:
in response to the battery being diagnosed to have sign of accelerated degradation, calculating a capacity ratio deviation indicating a difference between the representative initial CC capacity ratio and the representative reference CC capacity ratio; and
adjusting the cut-off voltage based on the capacity ratio deviation.

15. The battery diagnosis method according to claim 14 , wherein the adjusting of the cut-off voltage based on the capacity ratio deviation comprises:
determining a target SOC based on a reference State Of Charge (SOC) and the capacity ratio deviation, wherein the reference SOC is mapped to a reference cut-off voltage recorded in a predetermined reference SOC profile indicating a correlation between

Assignees

• Lg Energy Solution Ltd

Inventors

• Jeong Hee-Seok
• Bae Yoon-Jung

Classifications

• G01R31/3842

  combining voltage and current measurements · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• G01R31/392 Primary

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• G01R31/367

  Software therefor, e.g. for battery testing using modelling or look-up tables · CPC title

• G01R19/10

  Measuring sum, difference or ratio · CPC title