EP-4737922-A1 - APPARATUS AND METHOD FOR DIAGNOSING BATTERY

EP4737922A1EP 4737922 A1EP4737922 A1EP 4737922A1EP-4737922-A1

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.

Inventors

BAE, YOON-JUNG
KIM, JU-RI
KIM, TAE-IN
PAK, SEON-HO
SUN, Kyung-Eun
JEONG, HEE-SEOK

Assignees

LG Energy Solution, Ltd.

Dates

Publication Date: 20260506
Application Date: 20250131

Claims (14)

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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
A battery pack comprising the battery diagnosing apparatus according to claim 1.
An automobile comprising the battery diagnosing apparatus according to claim 1.
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.
A non-transitory computer-readable storage medium having stored therein a program that, when executed, causes a computer to perform 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.

Description

TECHNICAL FIELD This application is based on and claims priority from Korean Patent Application No. 10-2024-0014970 filed on January 31, 2024, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. The present disclosure relates to a battery diagnosing apparatus and method, and more specifically, to a battery diagnosing apparatus and method for diagnosing the state of a battery. BACKGROUND Recently, as the demand for portable electronic products such as notebook computers, video cameras, and portable telephones has rapidly increased, and as the development of electric vehicles, energy storage batteries, robots, and satellites has begun in earnest, researches on high-performance batteries allowing repeated charging and discharging are actively underway. Currently, commercialized batteries include, for example, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Of these batteries, lithium batteries are gaining considerable attention due to their advantages including a substantially low memory effect to allow a high degree of freedom in charging and discharging, a very low self-discharging rate, and high energy density, as compared to nickel-based batteries. While many studies are being conducted on the batteries focusing on the high-capacity and the high-density, it is also important to improve the lifespan and the safety of the batteries. In order to enhance the safety of batteries, a technology is necessary, which may accurately diagnose the current state of batteries. DISCLOSURE Technical Problem The present disclosure provides a battery diagnosing apparatus and method capable of diagnosing the state of a battery and controlling the battery based on the diagnosis result. Various aspects of the present disclosure may be understood through the following description and will become more apparent from the embodiments of the present disclosure. In addition, it will be readily understood that various aspects of the present disclosure may be implemented by the means and combinations thereof as described in the claims. Technical Solution A battery diagnosing apparatus according to one aspect of the present disclosure may include: 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. The control unit may be 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. The control unit may be 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. The control unit may be configured to 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. The control unit may be configured to 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. The control unit may be 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. 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. The control unit may be 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. The control unit may be 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. The control unit may be configured to divide the capacity section into a first section and a second