US-12618912-B2 - Apparatus and method for diagnosing battery

US12618912B2US 12618912 B2US12618912 B2US 12618912B2US-12618912-B2

Abstract

A battery diagnosing apparatus according to an embodiment of the present disclosure includes: a profile acquisition unit that acquires a differential profile representing a correspondence between a voltage and a differential capacity of a battery; a profile correction unit that determines a target C-rate corresponding to the differential profile, and corrects the differential profile based on an overvoltage profile corresponding to the target C-rate, thereby generating a corrected profile; and a control unit that determines a first target peak and a second target peak in the corrected profile, and diagnoses a state of the battery based on a behavior of the first target peak and a behavior of the second target peak.

Inventors

Soon-Hyung Choi
Dong-Hyun Kim
Young-Deok Kim

Assignees

LG ENERGY SOLUTION, LTD.

Dates

Publication Date: 20260505
Application Date: 20250124
Priority Date: 20240126

Claims (11)

1 . A battery diagnosing apparatus comprising: a profile acquisition unit configured to acquire a differential profile representing a correspondence between a voltage and a differential capacity of a battery; a profile correction unit configured to determine a target C-rate corresponding to the differential profile, and correct the differential profile based on an overvoltage profile corresponding to the target C-rate, thereby generating a corrected profile; and a control unit configured to determine a first target peak and a second target peak in the corrected profile, and diagnose a state of the battery based on a behavior of the first target peak and a behavior of the second target peak, wherein the overvoltage profile is based on a reference differential profile of a reference battery for a reference C-rate and a target differential profile of the reference battery for the target C-rate.
2 . The battery diagnosing apparatus according to claim 1 , wherein the control unit is configured to determine, as the first target peak, a minimum point with a lowest corresponding voltage in a voltage range including medium and higher voltages of the battery among minimum points included in the corrected profile.
3 . The battery diagnosing apparatus according to claim 1 , wherein the control unit is configured to determine, as the second target peak, a maximum point with a highest corresponding voltage among maximum points included in the corrected profile.
4 . The battery diagnosing apparatus according to claim 1 , wherein the control unit is configured to diagnose that the state of the battery is a positive electrode capacity loss state, when a voltage corresponding to the first target peak increases as a charging and discharging cycle of the battery progresses, and a differential capacity corresponding to the second target peak decreases as the charging and discharging cycle of the battery progresses.
5 . The battery diagnosing apparatus according to claim 1 , wherein the profile correction unit is configured to calculate a difference between the differential profile and the overvoltage profile to generate the corrected profile.
6 . The battery diagnosing apparatus according to claim 1 , wherein the overvoltage profile is pre-stored for each of a plurality of C-rates, and the profile correction unit is configured to select the overvoltage profile corresponding to the target C-rate from a plurality of pre-stored overvoltage profiles.
7 . The battery diagnosing apparatus according to claim 1 , wherein the overvoltage profile is preset to represent a difference between the reference differential profile and the target differential profile.
8 . A battery pack comprising the battery diagnosing apparatus according to claim 1 .
9 . A vehicle comprising the battery diagnosing apparatus according to claim 1 .
10 . A battery diagnosing method comprising: a profile acquisition step of acquiring a differential profile representing a correspondence between a voltage and a differential capacity of a battery; a target determination step of determining a target C-rate corresponding to the differential profile; a corrected profile generation step of correcting the differential profile based on an overvoltage profile corresponding to the target C-rate to generate a corrected profile; a target peak determination step of determining a first target peak and a second target peak in the corrected profile; and a battery diagnosis step of diagnosing a state of the battery based on a behavior of the first target peak and a behavior of the second target peak, wherein the overvoltage profile is based on a reference differential profile of a reference battery for a reference C-rate and a target differential profile of the reference battery for the target C-rate.
11 . A non-transitory computer-readable storage medium having stored therein a program for performing a battery diagnosing method, the method comprising: a profile acquisition step of acquiring a differential profile representing a correspondence between a voltage and a differential capacity of a battery; a target determination step of determining a target C-rate corresponding to the differential profile; a corrected profile generation step of correcting the differential profile based on an overvoltage profile corresponding to the target C-rate to generate a corrected profile; a target peak determination step of determining a first target peak and a second target peak in the corrected profile; and a battery diagnosis step of diagnosing a state of the battery based on a behavior of the first target peak and a behavior of the second target peak, wherein the overvoltage profile is based on a reference differential profile of a reference battery for a reference C-rate and a target differential profile of the reference battery for the target C-rate.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of KR Patent Application No. 10-2024-0012286 filed on Jan. 26, 2024, the contents of which are all hereby incorporated by reference herein in their entirety. TECHNICAL FIELD The present disclosure relates to a battery diagnosing apparatus and method, more particularly, an apparatus and method for diagnosing the state of a battery. BACKGROUND Recently, with the rapidly increasing demand for portable electronic products such as notebook computers, video cameras, and portable telephones, and the accelerating development of electric vehicles, energy storage batteries, robots, and satellites, researches on the high-performance batteries allowing repeated charging and discharging are actively underway. Currently, commercially available 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. SUMMARY An embodiment of the present disclosure provides a battery diagnosing apparatus and method, which may diagnose the current state of a battery relatively quickly. Various aspects of the present disclosure may be understood from the descriptions herein below, and may be more clearly understood from embodiments of the present disclosure. Further, it is readily apparent that various aspects of the present disclosure may be implemented by elements described in the claims and combinations thereof. A battery diagnosing apparatus according to an aspect of the present disclosure may include: a profile acquisition unit that acquires a differential profile representing a correspondence between a voltage and a differential capacity of a battery: a profile correction unit that determines a target C-rate corresponding to the differential profile, and corrects the differential profile based on an overvoltage profile corresponding to the target C-rate, thereby generating a corrected profile; and a control unit that determines a first target peak and a second target peak in the corrected profile, and diagnoses a state of the battery based on a behavior of the first target peak and a behavior of the second target peak. The control unit may be configured to determine, as the first target peak, a minimum point with a smallest corresponding voltage in a voltage range including medium and higher voltages of the battery among minimum points included in the corrected profile. The control unit may be configured to determine, as the second target peak, a maximum point with a largest corresponding voltage among maximum points included in the corrected profile. The control unit may be configured to diagnose that the state of the battery is a positive electrode capacity loss state, when a voltage corresponding to the first target peak increases as a charging and discharging cycle of the battery progresses, and a differential capacity corresponding to the second target peak decreases as the charging and discharging cycle of the battery progresses. The profile correction unit may be configured to calculate a difference between the differential profile and the overvoltage profile to generate the corrected profile. The overvoltage profile may be pre-stored for each of a plurality of C-rates. The profile correction unit may be configured to select the overvoltage profile corresponding to the target C-rate from a plurality of pre-stored overvoltage profiles. The overvoltage profile may be preset based on a reference differential profile of a reference battery for a reference C-rate and a target differential profile of the reference battery for the target C-rate. The overvoltage profile may be preset to represent a difference between the reference differential profile and the target differential profile. A battery pack according to another aspect of the present disclosure may include the battery diagnosing apparatus according to an aspect of the present disclosure. A vehicle according to yet another aspect of the present disclosure may include the battery diagnosing apparatus according to an aspect of the present disclosure. A battery diagnosing method according to still yet another aspect of the present disclosure may include: a profile acquisition step of acquiring a differential profile representing a correspondence between a voltage and a differential capacity of a battery: a target determinat