Apparatus and method for diagnosing battery

Patent metadata

Field	Value
Publication number	US-2025290995-A1
Application number	US-202519042665-A
Country	US
Kind code	A1
Filing date	Jan 31, 2025
Priority date	Jan 31, 2024
Publication date	Sep 18, 2025
Grant date	—

Abstract

A battery diagnosing apparatus according to one embodiment of the present disclosure includes: a profile acquisition unit that acquires a battery profile representing a correspondence between a voltage and a capacity of a battery; and a control unit that divides a capacity section of the battery profile into a plurality of sections, derives a target value for one target index related to charging efficiency among a plurality of diagnosis indices set in advance, from each of the divided sections, compares a correspondence between the derived plurality of target values with a preset reference profile that represents a correspondence between a plurality of target indices, and diagnoses a state of the battery based on a result of the comparison.

First claim

What is claimed is:

1 . A battery diagnosing apparatus comprising:
a profile acquisition unit configured to acquire a battery profile representing a correspondence between a voltage and a capacity of a battery: and a control unit configured to divide a capacity section of the battery profile into a plurality of sections, derive a target value for one target index related to charging efficiency among a plurality of diagnosis indices set in advance, from each of the divided sections, compare a correspondence between the derived plurality of target values with a preset reference profile that represents a correspondence between a plurality of target indices, and diagnose a state of the battery based on a result of the comparison.

2 . The battery diagnosing apparatus according to claim 1 , wherein the control unit is configured to determine a difference between a charging capacity of a nth cycle (where n is a natural number) and a discharge capacity of the nth cycle, as a target index corresponding to a low-capacity section among the plurality of sections, and determine a difference between the discharging capacity of the nth cycle and a charging capacity of a (n+1)th cycle, as a target index corresponding to a high-capacity section among the plurality of sections.

3 . The battery diagnosing apparatus according to claim 1 , wherein the control unit is configured to:
diagnose the state of the battery as a positive negative electrode deterioration state when a target point indicating the correspondence between the plurality of target values is included in the reference profile, diagnose the state of the battery as a negative electrode deterioration state when the target point is included in a first region based on the reference profile, and diagnose the state of the battery as a positive electrode deterioration state when the target point is included in a second region based on the reference profile.

4 . The battery diagnosing apparatus according to claim 3 , wherein the control unit is configured to diagnose the state of the battery as an end of life (EOL) state when the target point is included in a third region, and
the third region is configured to be preset as a region that exceeds a preset threshold value for each of the plurality of target indices.

5 . The battery diagnosing apparatus according to claim 3 , wherein the control unit is configured to reduce at least one of an upper limit current-rate (C-rate) and a constant voltage charging time set for the battery when the state of the battery is diagnosed as the positive electrode deterioration state or the positive negative electrode deterioration state.

6 . The battery diagnosing apparatus according to claim 3 , wherein the control unit is configured to reduce an upper charge limit voltage set for the battery when the state of the battery is diagnosed as the negative electrode deterioration state or the positive negative electrode deterioration state.

7 . The battery diagnosing apparatus according to claim 1 , wherein the control unit is configured to divide the capacity section into a first section and a second section based on a division ratio or a target capacity set in advance.

8 . The battery diagnosing apparatus according to claim 7 , wherein the profile acquisition unit is configured to further acquire a differential profile corresponding to the battery profile, and
the control unit is configured to determine a main peak from the differential profile and divide the capacity section based on a capacity of the determined main peak.

9 . The battery diagnosing apparatus according to claim 8 , wherein the differential profile is configured to represent a correspondence between a capacity of the battery and a differential voltage, and
the control unit is configured to determine a plurality of local minimum points in the differential profile, and determine a local minimum point with a smallest corresponding differential voltage among the determined plurality of local minimum points, as the main peak.

10 . The battery diagnosing apparatus according to claim 8 , wherein the differential profile is configured to represent a correspondence between a voltage and a differential capacity of the battery, and
the control unit is configured to determine a plurality of local maximum points in the differential profile, and determine a local maximum point with a largest corresponding differential voltage among the determined plurality of local maximum points, as the main peak.

11 . A battery pack comprising the battery diagnosing apparatus according to claim 1 .

12 . An automobile comprising the battery diagnosing apparatus according to claim 1 .

13 . A battery diagnosing method comprising:
a profile acquisition step of acquiring a battery profile representing a correspondence between a voltage and a capacity of a battery; a section division step of dividing a capacity section of the battery profile into a plurality of sections; a target value derivation step of deriving a target value for one target index related to charging efficiency among a plurality of diagnosis indices set in advance, from each of the divided sections; a comparison step of comparing a correspondence between the derived plurality of target values with a preset reference profile that represents a correspondence between a plurality of target indices; and a diagnosis step of diagnosing a state of the battery based on a result of the comparison.

14 . The battery diagnosing method according to claim 13 , further comprising:
a target index determination step of determining a difference between a charging capacity of a nth cycle (where n is a natural number) and a discharge capacity of the nth cycle, as a target index corresponding to a low-capacity section among the plurality of sections; and determining a difference between the discharging capacity of the nth cycle and a charging capacity of a (n+1)th cycle, as a target index corresponding to a high-capacity section among the plurality of sections.

15 . The battery diagnosing method according to claim 13 , wherein the diagnosis step includes:
diagnosing the state of the battery as a positive negative electrode deterioration state when a target point indicating the correspondence between the plurality of target values is included in the reference profile, diagnosing the state of the battery as a negative electrode deterioration state when the target point is included in a first region based on the reference profile, and diagnosing the state of the battery as a positive electrode deterioration state when the target point is included in a second region based on the reference profile.

16 . The battery diagnosing method according to claim 15 , wherein the diagnosis step includes diagnosing the state of the battery as an end of life (EOL) state when the target point is included in a third region, and
the third region is preset as a region that exceeds a preset threshold value for each of the plurality of target indices.

17 . The battery diagnosing method according to claim 15 , further comprising:
a battery control step of reducing at least one of an upper limit current-rate (C-rate) and a constant voltage charging time set for the battery when the state of the battery is diagnosed as the positive electrode deterioration state or the positive negative electrode deterioration state.

18 . The battery diagnosing method according to claim 15 , further comprising:
a battery control step of reducing an upper charge limit voltage set for the battery when t

Assignees

• Lg Energy Solution Ltd

Inventors

• Bae Yoon-Jung
• Kim Ju-Ri
• Kim Tae-In
• Pak Seon-Ho
• Sun Kyung-Eun
• Jeong Hee-Seok

Classifications

• H01M2010/4271

  Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing · CPC title

• H01M10/48

  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 title

• H01M10/44

  Methods for charging or discharging (circuits for charging H02J7/00) · CPC title

• G01R31/367

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

• G01R31/387

  Determining ampere-hour charge capacity or SoC · CPC title