EP-4737921-A1 - APPARATUS AND METHOD FOR MANAGING BATTERY

Abstract

A battery management apparatus according to one embodiment of the present disclosure includes a storage unit configured to store battery information including a voltage and current, and a control unit configured to calculate a capacity ratio of a battery based on the battery information, to compare the calculated capacity ratio for each of a plurality of voltage ranges with a preset reference capacity ratio, and to determine a state of the battery based on a comparison result.

Inventors

• CHOI, HYUN-JUN
• KIM, DAE-SOO
• KIM, YOUNG-DEOK

Assignees

• LG Energy Solution, Ltd.

Dates

Publication Date

20260506

Application Date

20241129

Claims (10)

1. A battery management apparatus comprising: a storage configured to store battery information including a voltage and current of a battery; and a controller configured to calculate a capacity ratio of the battery based on the battery information, compare the calculated capacity ratio for each of a plurality of voltage ranges with a preset reference capacity ratio, and determine a state of the battery based on a comparison result.
2. The battery management apparatus according to claim 1, wherein the controller is configured to calculate a capacity ratio difference between the capacity ratio for a target voltage range among the plurality of voltage ranges and the reference capacity ratio, and calculate a manifested capacity ratio due to a positive electrode of the battery based on the calculated capacity ratio difference.
3. The battery management apparatus according to claim 2, wherein the controller is configured to determine a voltage range where the capacity ratio is greater than or equal to the reference capacity ratio, among the plurality of voltage ranges, as the target voltage range.
4. The battery management apparatus according to claim 3, wherein the controller is configured to determine, among the plurality of voltage ranges, a voltage range starting from a lowest voltage range, where the capacity ratio is greater than or equal to the reference capacity ratio as the target voltage range.
5. The battery management apparatus according to claim 2, wherein the controller is configured to compare the manifested capacity ratio with a preset threshold, and, based on a comparison result, change a usage condition set for the battery.
6. The battery management apparatus according to claim 1, wherein the controller is configured to calculate a total capacity for an entire voltage range of the battery, and calculate a ratio of the calculated total capacity that corresponds to a capacity for each voltage range, so as to calculate the capacity ratio for that voltage range.
7. The battery management apparatus according to claim 1, wherein the battery is configured to contain a lithium-excess manganese-based oxide having a crystal structure where a layered LiMO 2 phase (where M is Ni, Co, or Mn) and a rock-salt structured Li 2 MnO 3 phase are mixed.
8. A battery pack comprising the battery management apparatus according to any one of claims 1 to 7.
9. A vehicle comprising the battery management apparatus according to any one of claims 1 to 7.
10. A battery management method comprising: calculating a capacity ratio of a battery based on battery information including a voltage and current of the battery; comparing the calculated capacity ratio for each of a plurality of voltage ranges with a preset reference capacity ratio; and determining a state of the battery based on a comparison result from the comparing.

Description

TECHNICAL FIELD This application is based on and claims priority from Korean Patent Application No. 10-2023-0190471, filed on December 22, 2023, 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 management apparatus and method, and more particularly, to a battery management apparatus and method for determining a state of a battery. BACKGROUND ART Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites is in full swing, research on high-performance batteries capable of repeated charging and discharging is being actively conducted. Currently commercialized batteries include nickel-cadmium batteries, nickel-hydride batteries, nickel-zinc batteries, and lithium batteries. Among these batteries, lithium batteries are gaining attention due to their advantages over the nickel-based batteries, such as minimal memory effects, which allows for more flexible charging and discharging, a very low self-discharge rate, and a high energy density. Among the electrochemical devices, interest in the development of rechargeable secondary batteries, is also emerging. In particular, the lithium secondary batteries developed in the early 1990s draw attention in that these batteries stand out for their high operating voltage and significantly superior energy density. Lithium secondary batteries that have been developed up to now mainly use lithium nickel-based oxides as a positive electrode active material, and carbon-based and/or silicon-based materials as a negative electrode active material. However, these conventional lithium secondary batteries do not sufficiently satisfy the energy density required for batteries used in, for example, electric vehicles. Therefore, in an effort to achieve a high capacity of the lithium secondary batteries, a method of applying lithium-excess manganese-based oxides as a positive electrode active material is being considered. Lithium-excess manganese-based oxides have a crystal structure where a layered phase (LiMO2) and a rock-salt phase (Li2MnO3) are mixed. A higher capacity may be activated through the activation of the rock-salt phase during charging or discharging, which leads to the manifestation of an additional capacity due to oxygen redox reactions. Specifically, since oxygen redox reactions cause manganese redox reactions, thereby further increasing the capacity of the battery. However, there is a problem in that during manganese redox reactions, the crystal structure of the positive electrode active material changes, resulting in deteriorated lifespan characteristics. DISCLOSURE Technical Problem The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery management apparatus and method for diagnosing the state of a battery based on the capacity ratio manifested by a positive electrode of the battery. These and other objects and advantages of the present disclosure may be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. Also, it will be easily understood that the objects and advantages of the present disclosure may be realized by the means shown in the appended claims and combinations thereof. Technical Solution A battery management apparatus according to an aspect of the present disclosure includes a storage unit configured to store battery information including a voltage and current, and a control unit configured to calculate a capacity ratio of a battery based on the battery information, compare the calculated capacity ratio for each of a plurality of voltage ranges with a preset reference capacity ratio, and determine a state of the battery based on a comparison result. The control unit may be configured to calculate a capacity ratio difference between the capacity ratio for a target voltage range among the plurality of voltage ranges and the reference capacity ratio, and, based on the calculated capacity ratio difference, calculate a manifested capacity ratio due to a positive electrode of the battery. The control unit may be configured to determine, among the plurality of voltage ranges, a voltage range where the capacity ratio is greater than or equal to the reference capacity ratio, as the target voltage range. The control unit may be configured to determine, among the plurality of voltage ranges, a voltage range starting from a lowest voltage range where the capacity ratio is greater than or equal to the reference capacity ratio, as the target voltage range. The control unit may be configured to compare the manifested capacity ratio with a preset threshold, and change a usage condition set for the battery based on a c