JP-2026514361-A - Battery degradation indicator information acquisition device and method, battery pack, and electric vehicle

JP2026514361AJP 2026514361 AJP2026514361 AJP 2026514361AJP-2026514361-A

Abstract

An apparatus and method for obtaining battery degradation index information are provided. The apparatus includes a measuring unit that generates voltage sample values and current sample values of a battery cell, and a control unit that sets first to n ranges of interest and first to n sampling rates for the current charge-discharge process based on previous degradation index information associated with the previous charge-discharge process. The control unit acquires the voltage sample values and current sample values at at least one sampling rate selected from a reference sampling rate and the first to n sampling rates during the current charge-discharge process. The control unit determines current degradation index information by performing peak detection for at least one of the first to n ranges of interest from the current differential voltage profile of the battery cell, which is generated based on the voltage sample values and current sample values acquired during the course of the current charge-discharge process.

Inventors

キムヤン－ジュン

Assignees

エルジーエナジーソリューションリミテッド

Dates

Publication Date: 20260511
Application Date: 20240723
Priority Date: 20230816

Claims (15)

A measuring unit configured to generate voltage and current sample values of a battery cell, Includes a control unit configured to set first to n ranges of interest and first to n sampling rates for the current charge-discharge process based on previous degradation index information associated with the previous charge-discharge process, The control unit, During the charging and discharging process described above, voltage sample values and current sample values of the battery cell are acquired at a reference sampling rate and at least one sampling rate selected from the first to n sampling rates. A battery degradation index information acquisition device configured to determine current degradation index information by detecting a peak in at least one of the first to n ranges of interest from the current differential voltage profile of the battery cell, which is generated based on the voltage sample value and current sample value acquired during the charging and discharging process, where n is a natural number of 2 or more.
The control unit, during the current charge/discharge process, If the capacity value of the battery cell falls within the i-th range of interest among the first to n-th ranges of interest, select the i-th sampling rate from the first to n-th sampling rates. The system is configured to select the reference sampling rate if the capacity value of the battery cell falls outside all of the first to nth ranges of interest. The battery degradation index information acquisition device according to claim 1, wherein i is a natural number less than or equal to n.
The battery degradation index information acquisition device according to claim 1, wherein each of the first to nth sampling rates is greater than the reference sampling rate.
The battery degradation index information acquisition device according to claim 1, wherein at least two of the first to nth sampling rates are identical to each other.
The aforementioned previous degradation indicator information is The data includes peak feature data from at least one of the first to nth peaks of interest already detected from the previous differential voltage profile, The battery degradation indicator information acquisition device according to claim 1, wherein the peak feature data represents at least one of capacity value, differential voltage value, or kurtosis.
The control unit, The battery degradation index information acquisition device according to claim 5, configured to set the size of the ith range of interest for the current charge/discharge process by applying a predetermined negative correspondence to the kurtosis of the ith peak of interest included in the aforementioned previous degradation index information, where i is a natural number less than or equal to n.
The control unit, The battery degradation index information acquisition device according to claim 5, configured to set an upper limit of the ith range of interest for the current charge/discharge process so as to be equal to the capacity value of the ith peak of interest among the first to nth peaks of interest included in the previous degradation index information, where i is a natural number less than or equal to n.
The control unit, The battery degradation index information acquisition device according to claim 5, configured to set the i-th sampling rate for the current charge/discharge process by applying a predetermined positive correspondence to the kurtosis of the i-th peak of interest included in the aforementioned previous degradation index information, wherein i is a natural number less than or equal to n.
A battery pack comprising a battery degradation indicator information acquisition device according to any one of claims 1 to 8.
An electric vehicle comprising the battery pack described in claim 9.
The steps include setting first to n ranges of interest and first to n sampling rates for the current charge-discharge process based on previous degradation index information associated with the previous charge-discharge process, During the aforementioned charging and discharging process, the steps include acquiring voltage sample values and current sample values of the battery cell at a predetermined reference sampling rate and at least one sampling rate selected from the first to n sampling rates, The steps include determining current degradation indicator information by detecting peaks in at least one of the first to n ranges of interest from the current differential voltage profile of the battery cell, which is generated based on the voltage sample values and current sample values acquired during the charging and discharging process, A method for obtaining battery degradation index information, wherein n is a natural number greater than or equal to 2.
The step of obtaining the voltage sample value and current sample value of the battery cell is: The following steps are repeated during the aforementioned charging and discharging process: If the capacity value of the battery cell falls within the i-th range of interest among the first to n-th ranges of interest, the step is to acquire the voltage sample value and current sample value of the battery cell at the i-th sampling rate among the first to n-th sampling rates, If the capacity value of the battery cell falls outside the range of interest from the first to the nth, the step is to acquire the voltage sample value and current sample value of the battery cell at the reference sampling rate. The method for obtaining battery degradation index information according to claim 11, wherein i is a natural number less than or equal to n.
The aforementioned previous degradation indicator information is The data includes peak feature data from at least one of the first to nth peaks of interest already detected from the previous differential voltage profile, The method for acquiring battery degradation index information according to claim 11, wherein the peak feature data represents at least one of capacity value, differential voltage value, or kurtosis.
The upper limit of the i-th range of interest for the aforementioned charge-discharge process is, The method for obtaining battery degradation index information according to claim 13, wherein the i is set to be equal to the capacity value of the ith peak of interest included in the aforementioned previous degradation index information, and i is a natural number less than or equal to n.
The i-th sampling rate for the charge-discharge process described above is: A method for acquiring battery degradation index information according to claim 13, wherein the kurtosis of the i-th peak of interest included in the aforementioned prior degradation index information is set to have a predetermined positive correspondence, and i is a natural number less than or equal to n.

Description

This invention relates to an apparatus and method for acquiring battery degradation indicator information. This application claims priority under Korean Patent Application No. 10-2023-0107209, filed on August 16, 2023, and Korean Patent Application No. 10-2024-0095689, filed on July 19, 2024. All information disclosed in the specifications and drawings of said applications is incorporated herein. Recently, the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased dramatically, and with the full-scale development of electric vehicles, energy storage batteries, robots, and satellites, research into high-performance batteries capable of repeated charging and discharging is becoming increasingly active. Currently available commercially include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are gaining attention due to their advantages over nickel-based batteries, including virtually no memory effect, allowing for flexible charging and discharging, extremely low self-discharge rates, and high energy density. Generally, such batteries degrade with use. Therefore, accurately estimating the charge state (SOC) and health state (SOH) of a degraded battery, or controlling its operation to extend its lifespan, requires accurately assessing the battery's condition. Conventionally, a method has been used to estimate the degree of battery degradation by detecting at least two peaks from a differential voltage profile generated based on measured values of the battery's voltage and current, and then comparing the peak characteristic information of the two peaks. However, as the battery degrades, the shape of the differential voltage profile gradually changes. Therefore, if the sampling rate for voltage and current measurements is low, the accuracy of detecting each peak in the differential voltage profile may decrease. To improve this, it would be necessary to increase the applied sampling rate. However, this would not only require a large amount of memory to record battery data, but also increase power consumption during sampling, leading to an excessive computational load on battery data processing. This diagram illustrates the configuration of an electric vehicle according to the present invention.This graph is used to compare two voltage profiles generated by two adjacent charge/discharge processes.This graph is referenced to compare two differential voltage profiles that have a one-to-one correspondence with the two voltage profiles shown in Figure 2.This is a diagram referenced to illustrate the procedure for defining the scope of interest for a specific charge-discharge process.This figure is referenced to illustrate the change in peak detection power in response to changes in the applied sampling rate.This figure is referenced to illustrate the change in peak detection power in response to changes in the applied sampling rate.This figure is referenced to illustrate the change in peak detection power in response to changes in the applied sampling rate.This flowchart is used to illustrate, in part, a method for obtaining battery degradation indicator information according to another embodiment of the present invention.This is a flowchart referenced to illustrate the subroutine in step S610 of Figure 6.This flowchart is referenced to illustrate the subroutine in step S611 of Figure 6. The following describes preferred embodiments of the present invention in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims are not to be interpreted in their usual and dictionary sense, but rather in accordance with the technical ideas of the present invention, in accordance with the principle that the inventor can appropriately define the concepts of terms in order to best describe the invention. Therefore, the configurations shown in the embodiments described herein represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the invention. It should be understood that, at the time of this application, there may be a variety of equivalents and modifications that can be substituted therewith. Terms including ordinal numbers, such as "first," "second," etc., are used to distinguish one component from the others, and are not used to limit the components themselves. Throughout the specification, when a part "includes" a certain component, this means, unless otherwise stated, that it may include other components rather than excluding them. Furthermore, terms such as "control unit" in the specification refer to a unit that processes at least one function or operation, and can be implemented by hardware, software, or a combination of hardware and software. Furthermore, throughout the specification, when one part is described as being "connected" to another part, thi