Battery management device and method

Abstract

A battery management apparatus according to an embodiment of the present disclosure includes: a curve acquisition unit configured to acquire a differential curve indicating a correspondence relationship between a voltage of a battery and a differential capacity; and a control unit configured to determine a target peak from among a plurality of peaks included in the differential curve, determine a remaining peak other than the target peak among the plurality of peaks as a reference peak, compare a differential capacity of the target peak with a differential capacity of the reference peak, determine a voltage of interest based on a result of the differential capacity comparison, and estimating a degree of degradation of the battery based on a capacity of interest of the battery corresponding to the voltage of interest.

Description

Technical Field

[0001] The present disclosure relates to a battery management device and method, and more particularly to a battery management device and method for estimating a degree of battery degradation.

[0002] This application claims priority from Korean Patent Application No. 10-2023-0149458 filed in Korea on November 1, 2023, the disclosure of which is incorporated herein by reference. Background Art

[0003] Recently, demand for portable electronic products such as laptop computers, cameras, and mobile phones has rapidly increased, and with the widespread development of electric vehicles, accumulators for energy storage, robots, and satellites, much research is being conducted on high-performance batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc., and among them, lithium batteries have little or no memory effect, and therefore they have received more attention than nickel-based batteries because they have the advantages of being able to be recharged whenever convenient, having a very low self-discharge rate and high energy density.

[0005] Because batteries degrade during operation, much research is ongoing to more accurately estimate the condition and state of health (SOH) of batteries during operation.

[0006] Typically, the battery degradation degree can be estimated by comparing the standard capacity with the current capacity based on the time point when the battery is fully charged. However, when estimating the battery degradation degree based on the time point when the battery is fully charged, it is difficult to quickly estimate the battery degradation degree because it takes time to fully charge the battery.

[0007] At the same time, the change in capacity of the battery in the corresponding voltage range can be calculated by integrating the differential curve with respect to the voltage V, wherein the differential curve indicates the corresponding relationship between the differential capacity dQ / dV and the voltage V, and the differential capacity dQ / dV is the change in capacity Q as a function of the voltage V in the battery. When the shapes of the differential curves of two batteries are similar in a specific voltage range, it can be considered that the change in capacity between the two batteries in the corresponding voltage range is also similar.

[0008] Therefore, when estimating the degree of degradation of a battery based on the capacity of the battery, it is necessary to develop a technique for variously determining a voltage of interest for estimating the degree of degradation according to the shape of a differential curve. Summary of the Invention

[0009] Technical issues

[0010] The present disclosure is designed to solve the above-mentioned problems, and therefore the present disclosure aims to provide a battery management device and method for estimating a battery degradation degree based on a capacity of interest corresponding to each voltage of interest by differently determining the voltage of interest according to the shape of a differential curve.

[0011] These and other purposes and advantages of the present disclosure can be understood from the following description and will become apparent from the embodiments of the present disclosure. Moreover, it will be easily understood that the purposes and advantages of the present disclosure can be achieved by the means set forth in the appended claims and their combinations.

[0012] Technical Solution

[0013] A battery management device according to one aspect of the present disclosure may include: a curve acquisition unit configured to acquire a differential curve indicating a correspondence between a voltage and a differential capacity of a battery; and a control unit configured to determine a target peak from a plurality of peaks included in the differential curve, determine the remaining peaks other than the target peak in the plurality of peaks as reference peaks, compare the differential capacity of the target peak with the differential capacity of the reference peak, determine a voltage of interest based on a result of the differential capacity comparison, and estimate a degree of degradation of the battery based on the capacity of interest of the battery corresponding to the voltage of interest.

[0014] The control unit may be configured to determine a peak having a highest corresponding voltage among the plurality of peaks as the target peak.

[0015] The control unit may be configured to determine a preset standard voltage as the voltage of interest when the differential capacity of the target peak exceeds the differential capacity of the reference peak.

[0016] The standard voltage may be preset as a voltage corresponding to a standard minimum point having a highest corresponding voltage among a plurality of minimum points included in a preset standard differential curve of the battery.

[0017] The standard minimum point may be preset as a minimum point having the highest corresponding voltage on a low voltage side of a standard peak corresponding to a target peak.

[0018] The standard voltage may be preset as a voltage of a standard peak corresponding to the target peak among a plurality of peaks included in the standard differential curve.

[0019] The control unit may be configured to determine the end-of-charge voltage of the battery as the voltage of interest when the differential capacity of the target peak is equal to or smaller than the differential capacity of the reference peak.

[0020] The control unit may be configured to estimate a difference between a preset standard capacity and the capacity of interest as a degree of degradation of the battery.

[0021] The control unit may be configured to estimate a ratio of the capacity of interest to a preset standard capacity as a degree of degradation of the battery.

[0022] The standard capacity may be a preset capacity corresponding to the voltage of interest.

[0023] The control unit may be configured to set a usage condition of the battery based on the estimated degree of degradation of the battery.

[0024] A battery pack according to another aspect of the present disclosure may include the battery management device according to an aspect of the present disclosure.

[0025] A vehicle according to still another aspect of the present disclosure may include the battery management device according to an aspect of the present disclosure.

[0026] According to another aspect of the present disclosure, a battery management method may include: a curve acquisition step of acquiring a differential curve indicating the correspondence between the voltage and differential capacity of the battery; a peak determination step of determining a target peak from a plurality of peaks included in the differential curve, and determining the remaining peaks other than the target peak among the plurality of peaks as reference peaks; a comparison step of comparing the differential capacity of the target peak with the differential capacity of the reference peak; a voltage determination step of determining a voltage of interest based on a result of the differential capacity comparison; and a degradation degree estimation step of estimating the degree of degradation of the battery based on the capacity of interest of the battery corresponding to the voltage of interest.

[0027] Beneficial effects

[0028] According to an aspect of the present disclosure, the battery management apparatus may estimate the battery degradation degree based on the capacity of interest corresponding to each voltage of interest by differently determining the voltage of interest for estimating the battery degradation degree according to the shape of a differential curve.

[0029] In addition, according to an aspect of the present disclosure, the battery management device can prevent battery degradation or accelerate degradation by setting usage conditions of the battery according to the degree of battery degradation.

[0030] In addition, according to one aspect of the present disclosure, the battery management device can quickly compare the relative degradation levels of multiple batteries in a battery module or battery pack. In addition, by setting the usage conditions of multiple batteries based on the relative degradation levels, the level of deviation in the degradation levels of multiple batteries can be reduced.

[0031] The effects of the present disclosure are not limited to the above-described effects, and those skilled in the art will clearly understand these and other effects from the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a better understanding of the technical aspects of the present disclosure together with the following detailed description, and thus the present disclosure should not be construed as being limited to the accompanying drawings.

[0033] Figure 1 is a diagram schematically illustrating a battery management device according to an embodiment of the present disclosure.

[0034] Figure 2 and Figure 3 is a diagram schematically illustrating a first differential curve according to an embodiment of the present disclosure.

[0035] Figure 4 is a diagram schematically illustrating a second differential curve according to another embodiment of the present disclosure.

[0036] Figure 5 is a diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0037] Figure 6 is a diagram schematically illustrating a vehicle according to another embodiment of the present disclosure.

[0038] Figure 7 is a diagram schematically illustrating a battery management method according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] It should be understood that the terms or words used in the specification and the appended claims should not be construed as limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concepts corresponding to the technical aspects of the present disclosure, based on the principle allowing the inventor to appropriately define the terms for the best interpretation.

[0040] Therefore, the embodiments described herein and the illustrations shown in the accompanying drawings are provided to describe the technical aspects of the present disclosure by way of example, but are not intended to be limiting, and it should be understood that various other equivalents and modifications may be made thereto upon filing of an application.

[0041] In describing the present disclosure, when it is determined that certain detailed descriptions of related known elements or functions may make the subject matter of the present disclosure obscure or unclear, the detailed descriptions are omitted.

[0042] The terms “first,” “second,” etc. are used to distinguish one element from another among various elements, and are not intended to limit the elements by the terms.

[0043] Unless the context clearly indicates otherwise, the terms “comprise” and “comprising” when used in this specification specify the presence of stated elements, but do not preclude the presence or addition of one or more other elements.

[0044] Furthermore, throughout the specification, it will be understood that when an element is referred to as being “connected to” another element, it can be directly connected to the other element or intervening elements may be present.

[0045] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0046] Figure 1 is a diagram schematically illustrating a battery management device according to an embodiment of the present disclosure.

[0047] Reference Figure 1 The battery management device 100 according to an embodiment of the present disclosure may include a curve acquisition unit 110 and a control unit 120 .

[0048] Here, a battery refers to an independent but physically separable cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery can be considered a battery. In addition, the type of battery may include cylindrical, prismatic, or pouch-shaped. In addition, a battery may refer to a battery bank, battery module, or battery pack that includes multiple battery cells connected in series and / or parallel. Hereinafter, for ease of description, a battery is described as referring to an independent cell.

[0049] The curve acquisition unit 110 may be configured to acquire a differential curve indicating a corresponding relationship between the voltage and the differential capacity of the battery.

[0050] Here, the differential capacity indicates an instantaneous change in capacity as a function of voltage. That is, the differential capacity is a value obtained by differentiating the capacity with respect to voltage and can be expressed as 'dQ / dV'.

[0051] The battery curve is a curve indicating the corresponding relationship between the voltage V and the capacity Q while the battery is charged from SOC 0% to SOC 100%. In addition, when the battery curve is differentiated with respect to the voltage, a differential curve indicating the corresponding relationship between the differential capacity dQ / dV and the voltage V can be generated. Conversely, the battery curve may indicate the corresponding relationship between the voltage V and the capacity Q while the battery is discharged from SOC 100% to SOC 0%.

[0052] For example, there are no specific restrictions on the C-rate used in charging or discharging to generate a battery curve. However, it is preferable to charge or discharge the battery at a low rate to more accurately obtain a battery curve and a differential curve. For example, a battery curve can be generated during charging or discharging of the battery at 0.05 C.

[0053] Preferably, the curve acquisition unit 110 may be configured to acquire a differential curve indicating a corresponding relationship between the differential capacity and voltage of the battery during charging. For example, a battery curve may be acquired during charging of the battery, and the differential curve may be acquired from the battery curve.

[0054] As an example, the curve acquisition unit 110 may directly receive the differential curve of the battery from the external device. That is, the curve acquisition unit 110 may acquire the differential curve of the battery by receiving the differential curve via a wired and / or wireless connection to the external device.

[0055] As another example, curve acquisition unit 110 may receive battery information associated with the voltage and capacity of the battery. Furthermore, curve acquisition unit 110 may generate a battery curve based on the received battery information, and generate a differential curve based on the generated battery curve. In other words, curve acquisition unit 110 may acquire a differential curve by directly generating the differential curve based on the battery information.

[0056] As another example, curve acquisition unit 110 can directly measure the battery's voltage and current. For example, curve acquisition unit 110 can directly measure the battery's voltage via direct connection to the battery's positive and negative terminals. Furthermore, curve acquisition unit 110 can measure the battery's charge and discharge currents and calculate the battery's capacity based on the measured currents. Furthermore, curve acquisition unit 110 can generate a differential curve based on the battery's voltage and capacity. In other words, curve acquisition unit 110 can acquire a differential curve based on the directly measured battery voltage and current.

[0057] The curve acquisition unit 110 may be connected to the control unit 120 to enable communication therebetween. For example, the curve acquisition unit 110 may be connected to the control unit 120 by wire and / or wirelessly. The curve acquisition unit may send the acquired differential curve to the control unit 120.

[0058] Figure 2 and Figure 3 is a diagram schematically illustrating a first differential curve DP1 according to an embodiment of the present disclosure.

[0059] Figure 2 1 is a diagram referred to in describing an embodiment of a battery management device 100 according to the present disclosure.

[0060] exist Figure 2 In the embodiment of FIG. 5 , the first differential curve DP1 may be represented as a two-dimensional graph in which the X-axis is set to the voltage V and the Y-axis is set to the differential capacity dQ / dV.

[0061] The control unit 120 may be configured to determine a target peak from among a plurality of peaks included in the differential curve.

[0062] refer to Figure 2 , the first differential curve DP1 may include a plurality of peaks P11 , P212 , and P13 .

[0063] Here, a peak refers to the point where the slope of a curve changes from a positive (+) value to a negative (-) value (instantaneously). That is, relative to the peak, the slope is positive on the low-voltage side, and negative on the high-voltage side. In other words, the peak is determined by the maximum point of the differential curve.

[0064] Specifically, the target peak may be determined based on its relative position to other peaks in the differential curve. More specifically, the target peak may be determined based on the corresponding voltage.

[0065] For example, the control unit 120 may determine the peak with the highest corresponding voltage among the multiple peaks as the target peak. When there is only one peak in the differential curve, the corresponding peak may be determined as the target peak.

[0066] exist Figure 2 In the embodiment of FIG. 1 , the control unit 120 may determine the peak P13 having the highest corresponding voltage among the multiple peaks P11 , P12 , and P13 as the target peak.

[0067] The control unit 120 may be configured to determine the remaining peaks except the target peak among the plurality of peaks included in the differential curve as reference peaks.

[0068] Specifically, the control unit 120 may determine the peak with the highest corresponding voltage among the multiple peaks included in the differential curve as the target peak, and determine the remaining peaks as reference peaks. In other words, the control unit 120 may determine the peak with a lower corresponding voltage than the target peak among the multiple peaks as the reference peak.

[0069] For example, in Figure 2 In the embodiment of the present invention, the control unit 120 may determine the remaining peaks P11 and P12 excluding the target peak P13 among the plurality of peaks included in the first differential curve DP1 as reference peaks.

[0070] The control unit 120 may be configured to compare the differential capacity of the target peak with the differential capacity of the reference peak.

[0071] Specifically, the control unit 120 may compare the differential capacity of the target peak with the differential capacity of the reference peak. For example, the control unit 120 may compare the differential capacity of the target peak with the differential capacity of the reference peak to determine which differential capacity is larger or smaller. In the case of multiple reference peaks, the control unit 120 may compare the differential capacity of each of the multiple reference peaks with the differential capacity of the target peak.

[0072] For example, in Figure 2 In the embodiment of FIG, due to the plurality of reference peaks, the control unit 120 may compare the differential capacity of each of the plurality of reference peaks P11 and P12 with the differential capacity of the target peak P13. That is, the control unit 120 may compare the differential capacity of the reference peak P11 with the differential capacity of the target peak P13, and compare the differential capacity of the reference peak P12 with the differential capacity of the target peak P13.

[0073] The control unit 120 may be configured to determine a voltage of interest based on the differential capacity comparison result.

[0074] Specifically, when the differential capacity of the target peak exceeds the differential capacity of the reference peak, the control unit 120 may determine a preset standard voltage as the voltage of interest. Here, the standard voltage may be preset as a voltage lower than the charge end voltage set for the battery.

[0075] More specifically, the standard voltage refers to the voltage of a standard battery. Here, the standard battery can be a reference battery corresponding to a battery or a battery at the battery end-of-line (BOL). However, for ease of description, the standard battery will be described below as being at the battery end-of-line (BOL). The standard voltage can be preset based on the shape of a standard differential curve, which is a differential curve obtained from a standard battery. In other words, the standard voltage can be preset based on the relationship between the voltage and differential capacity of the standard battery.

[0076] For example, the standard voltage can be preset to the voltage of the standard minimum point with the highest corresponding voltage among the multiple minimum points included in the standard differential curve. Preferably, the standard minimum point can be preset to the minimum point with the highest corresponding voltage on the low voltage side of the standard peak corresponding to the target peak. Here, the standard peak can refer to the peak with the highest corresponding voltage among the multiple peaks included in the standard differential curve. That is, the target peak is the peak with the highest corresponding voltage among the multiple peaks included in the differential curve of the battery, and the standard peak is the peak with the highest corresponding voltage among the multiple peaks included in the standard differential curve. Therefore, the standard peak and the target peak can correspond to each other.

[0077] For example, in Figure 2In the embodiment, the differential capacity of target peak P13 exceeds the differential capacity of the reference peaks P11 and P12. That is, the differential capacity of target peak P13 exceeds the differential capacity of reference peak P11 and the differential capacity of reference peak P12. Therefore, control unit 120 can determine preset standard voltage RV1 as the voltage of interest.

[0078] Specifically, the voltage of the standard minimum point M12 having the highest corresponding voltage on the low-voltage side of the standard peak R_pe corresponding to the target peak P13 among the multiple minimum points M11, M12, and M13 included in the standard differential curve R_DP can be preset as the standard voltage RV1. In other words, the voltage of the standard peak R_pe having the highest corresponding voltage among the multiple peaks included in the standard differential curve R_DP is determined, and the minimum point M12 having the highest corresponding voltage among the multiple minimum points M11 and M12 on the lower voltage side than the voltage of the standard peak R_pe in the first differential curve DP1 can be determined as the standard minimum point. Therefore, the voltage of the standard minimum point M12 can be preset as the standard voltage RV1.

[0079] As another example, the standard voltage may be preset as a voltage of a standard peak corresponding to the target peak among a plurality of peaks included in the standard differential curve.

[0080] Figure 3 FIG. 2 is a schematic diagram for describing another embodiment of a battery management device 100 according to the present disclosure.

[0081] exist Figure 3 In the embodiment of FIG. 5 , the first differential curve DP1 may be represented as a two-dimensional graph in which the X-axis is set to the voltage V and the Y-axis is set to the differential capacity dQ / dV.

[0082] Figure 3 The standard differential curve R_DP and the first differential curve DP1 are Figure 2 The standard differential curve R_DP shown is the same as the first differential curve DP1. Figure 2 The target peak P13, the reference peak P11, the reference peak P12 and the standard peak R_pe are determined in the same manner as in the embodiment.

[0083] For example, in Figure 3 In the embodiment, the differential capacity of target peak P13 exceeds the differential capacity of the reference peaks P11 and P12. That is, the differential capacity of target peak P13 exceeds the differential capacity of reference peak P11 and the differential capacity of reference peak P12. Therefore, control unit 120 can determine preset standard voltage RV2 as the voltage of interest.

[0084] Specifically, the standard voltage RV2 may be preset as the voltage of the standard peak R_pe corresponding to the target peak P13 among the multiple peaks included in the standard differential curve R_DP. In other words, the voltage of the peak with the highest corresponding voltage among the multiple peaks included in the standard differential curve R_DP may be preset as the standard voltage RV2.

[0085] In contrast, when the differential capacity of the target peak is equal to or smaller than the differential capacity of the reference peak, the control unit 120 may determine the charge end voltage set for the battery as the voltage of interest.

[0086] In the case of multiple reference peaks, the differential capacity of the target peak being equal to or less than the differential capacity of the reference peaks means that the differential capacity of the target peak is equal to or less than the differential capacity of at least one of the multiple reference peaks. In other words, when the differential capacity of at least one reference peak is equal to or greater than the differential capacity of the target peak, it can be considered that the differential capacity of the target peak is equal to or less than the differential capacity of the reference peaks.

[0087] Figure 4 FIG. 4 is a schematic diagram of a second differential curve DP2 according to another embodiment of the present disclosure.

[0088] Figure 4 FIG. 2 is a schematic diagram for describing another embodiment of a battery management device 100 according to the present disclosure.

[0089] exist Figure 4 In the embodiment of FIG. 5 , the second differential curve DP2 may be represented as a two-dimensional graph in which the X-axis is set to the voltage V and the Y-axis is set to the differential capacity dQ / dV.

[0090] The control unit 120 may determine the peak P23 having the highest corresponding voltage among the plurality of peaks P21, P22, and P23 included in the second differential curve DP2 as the target peak. In addition, the control unit 120 may determine the remaining peaks P21 and P22 among the plurality of peaks P21, P22, and P23 except the target peak P23 as reference peaks.

[0091] The differential capacity of target peak P23 exceeds the differential capacity of reference peak P21 but is equal to or less than the differential capacity of reference peak P22. In other words, the differential capacity of target peak P23 is equal to or less than the differential capacity of the reference peak. Therefore, control unit 120 can determine the end-of-charge voltage EoC (e.g., 4.2 V) set for the battery as the voltage of interest.

[0092] The control unit 120 may be configured to estimate the degree of degradation of the battery based on the capacity of interest of the battery corresponding to the voltage of interest.

[0093] Specifically, the control unit 120 may calculate a capacity of interest of the battery corresponding to a voltage of interest.

[0094] For example, when the voltage of interest is set to a preset standard voltage, the control unit 120 may calculate the capacity of the battery corresponding to the standard voltage as the capacity of interest. As another example, when the voltage of interest is set to the charge end voltage, the control unit 120 may calculate the battery capacity corresponding to the charge end voltage as the capacity of interest. Figure 2 In the embodiment of , the control unit 120 can calculate the capacity of interest of the battery by integrating the first differential curve DP1 with respect to the voltage up to the standard voltage RV1. As another example, in Figure 3 In the embodiment of , the control unit 120 can calculate the capacity of interest of the battery by integrating the first differential curve DP1 with respect to the voltage up to the standard voltage RV2. As another example, in Figure 4 In the embodiment of FIG. 5 , the control unit 120 may calculate the capacity of interest of the battery by integrating the second differential curve DP2 with respect to the voltage up to the end-of-charge voltage EoC.

[0095] In addition, the control unit 120 may estimate the degree of degradation of the battery through comparison between the capacity of interest and the standard capacity.

[0096] Here, the degree of degradation of the battery may refer to the difference between the standard capacity of the battery and the capacity of interest. Alternatively, the degree of degradation of the battery may refer to the ratio of the capacity of interest to the standard capacity of the battery. Here, the standard capacity of the battery is the capacity of a standard battery corresponding to the voltage of interest. For example, when the voltage of interest is the end-of-charge voltage, the standard capacity may be the fully charged capacity (e.g., total capacity) of the battery at BOL. As another example, when the voltage of interest is a preset standard voltage, the standard capacity may be the partial capacity of the battery at BOL corresponding to the standard voltage. For example, at Figure 2 In the embodiment of , the standard capacity is a value obtained by integrating the standard differential curve R_DP with respect to the voltage up to the standard voltage RV1. As another example, in Figure 3 In the embodiment of , the standard capacity is a value obtained by integrating the standard differential curve R_DP with respect to the voltage up to the standard voltage RV2. As another example, in Figure 4 In the embodiment of FIG. 5 , the standard capacity is a value obtained by integrating the standard differential curve R_DP with respect to the voltage up to the end-of-charge voltage EoC.

[0097] For example, control unit 120 can estimate the battery degradation by calculating the ratio of the capacity of interest to the standard capacity. Specifically, control unit 120 can estimate the battery degradation by calculating the formula "capacity of interest ÷ standard capacity × 100." In this equation, 100 is a constant used to keep the battery degradation within the range of 0 (%) to 100 (%) and can be omitted.

[0098] The battery management device 100 according to an embodiment of the present disclosure may estimate the degradation degree of the battery based on the capacity of interest corresponding to each voltage of interest by differently determining the voltage of interest for estimating the degradation degree of the battery according to the shape of the differential curve.

[0099] Generally, the degree of degradation of a battery can be estimated by comparing the standard capacity with the current capacity based on the time point when the battery is fully charged. However, when the shape of the differential curve is a specific shape, even if the degree of degradation of the battery is estimated based on the time point before the battery is fully charged, the error in the estimated degree of degradation may not be significant. For example, as in Figure 2 In an embodiment, when the voltage of target peak P13 is the highest among the multiple peaks P11, P12, and P13, the capacity difference between the capacity after the standard voltage RV1 of the standard differential curve R_DP and the capacity after the standard voltage RV1 of the first differential curve DP1 can be negligible. Therefore, even if the battery is charged to the standard voltage RV1, the degree of battery degradation can be quickly estimated simply by comparing the standard capacity and the capacity of interest.

[0100] Meanwhile, the control unit 120 of the battery management device 100 may selectively include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, or a data processing device known in the art to execute the various control logics implemented in the present disclosure. Furthermore, when the control logic is implemented as software, the control unit 120 may be implemented as a set of program modules. In this case, the program modules may be stored in a memory and executed by the control unit 120. The memory may be internal or external to the control unit 120 and may be connected to the control unit 120 via various well-known means.

[0101] The battery management device 100 may also include a storage unit 130. The storage unit 130 may store data or programs required for each component of the battery management device 100 to perform operations and functions, or data created during the execution of operations and functions. The storage unit 130 is not limited to a specific type and may include any known information storage device capable of recording, erasing, updating, and exporting data. As examples, the information storage device may include RAM, flash memory, ROM, EEPROM, or registers. Furthermore, the storage unit 130 may store program code that defines processes executable by the control unit 120.

[0102] Specifically, storage unit 130 may store information necessary for control unit 120 to estimate the degree of battery degradation. For example, storage unit 130 may store a standard voltage, a battery differential curve, a voltage of interest, and a capacity of interest. Furthermore, control unit 120 may access storage unit 130 to obtain the information necessary to estimate the degree of battery degradation.

[0103] The control unit 120 may be configured to set a usage condition of the battery based on the estimated degree of degradation of the battery.

[0104] When the battery's charge end voltage is determined to be the voltage of interest, the control unit 120 can estimate the battery's degradation degree based on the full charge capacity. The control unit 120 can set a battery usage condition according to the estimated degradation degree based on the full charge capacity.

[0105] Specifically, control unit 120 may adjust the upper limit of the battery's charge / discharge rate (C-rate) range. For example, control unit 120 may reduce the upper limit of the battery's charge / discharge rate range. For another example, control unit 120 may increase the lower limit of the battery's charge / discharge rate range. For yet another example, control unit 120 may reduce the upper limit of the battery's charge / discharge rate range and increase the lower limit of the battery's charge / discharge rate range.

[0106] Alternatively, the control unit 120 may adjust the battery's available SOC range. As an example, the control unit 120 may reduce the upper limit of the battery's available SOC range. As another example, the control unit 120 may increase the lower limit of the battery's available SOC range. As yet another example, the control unit 120 may reduce the upper limit of the battery's available SOC range and increase the lower limit of the available SOC range.

[0107] That is, the battery management device 100 according to an embodiment of the present disclosure can prevent battery degradation or accelerate degradation by adjusting the charge / discharge rate range or the available SOC range according to the degree of degradation of the battery.

[0108] In addition, when the standard voltage is determined to be the voltage of interest, the control unit 120 can estimate the degree of degradation of the battery based on the capacity of interest. In this case, when the battery is only charged to the standard voltage, the degree of degradation of the battery can be quickly estimated. The degree of degradation estimated based on the standard voltage is an approximation of the degree of degradation estimated based on the end-of-charge voltage, and can be used to compare the relative degrees of degradation between multiple batteries in a battery module or battery pack. The control unit 120 can set the use conditions of multiple batteries based on the relative degrees of degradation between the multiple batteries. As an example, the control unit 120 can reduce the upper limit of the charge / discharge rate range of a battery with a larger relative degree of degradation among the multiple batteries, or increase the lower limit of the charge / discharge rate range, or both. As another example, the control unit 120 can increase the upper limit of the charge / discharge rate range of a battery with a small relative degree of degradation among the multiple batteries, or increase the lower limit of the charge / discharge rate range, or both.

[0109] That is, the battery management device 100 according to an embodiment of the present disclosure can quickly compare the relative degradation levels of multiple batteries in a battery module or battery pack. In addition, by setting the usage conditions of multiple batteries based on the relative degradation levels, the deviation level of the degradation levels among the multiple batteries can be reduced.

[0110] The battery management device 100 according to the present disclosure can be applied to a battery management system (BMS). That is, the BMS according to the present disclosure can include the battery management device 100. In this configuration, at least some of the components of the battery management device 100 can be implemented by supplementing or adding functionality to components typically included in a BMS. For example, the curve acquisition unit 110, control unit 120, and storage unit 130 of the battery management device 100 can be implemented as components of the BMS.

[0111] Furthermore, the battery management device 100 according to the present disclosure may be assembled in a battery pack. That is, the battery pack according to the present disclosure may include the battery management device 100 and at least one battery cell. Furthermore, the battery pack may further include electrical components (relays, fuses) and a housing.

[0112] Figure 5 is a diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0113] The positive terminal of the battery 11 may be connected to the positive terminal (P+) of the battery pack 10 , and the negative terminal of the battery 11 may be connected to the negative terminal (P−) of the battery pack 10 .

[0114] The measuring unit 20 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measuring unit 20 may be connected to the positive terminal of the battery 11 through the first sensing line SL1 and to the negative terminal of the battery 11 through the second sensing line SL2. The measuring unit 20 may measure the voltage of the battery 11 based on the voltage measured at each of the first sensing line SL1 and the second sensing line SL2.

[0115] In addition, the measurement unit 20 can be connected to the current measurement unit A via the third sensing line SL3. For example, the current measurement unit A can be an ammeter or a shunt resistor for measuring the charging current and discharging current of the battery 11. The measurement unit 20 can measure the charging current of the battery 11 via the third sensing line SL3 and calculate the charge capacity. In addition, the measurement unit 20 can measure the discharge current of the battery 11 via the third sensing line SL3 and calculate the discharge capacity.

[0116] An external device (not shown) may be connected to the positive terminal (P+) of the battery pack 10 at one end and to the negative terminal (P-) of the battery pack 10 at the other end. Thus, the positive terminal of the battery 11, the positive terminal (P+) of the battery pack 10, the external device, the negative terminal (P-) of the battery pack 10, and the negative terminal of the battery 11 may be electrically connected.

[0117] For example, the external device may be a charger or a load such as a motor of an electric vehicle supplied with power from the battery 11 .

[0118] Figure 6 A vehicle 1 according to another embodiment of the present disclosure is schematically shown.

[0119] refer to Figure 6 The battery pack 10 according to an embodiment of the present disclosure may be included in a vehicle 1 such as an electric vehicle (EV) or a hybrid electric vehicle (HV). Here, the battery pack 10 described above may be used as the battery pack 10 . Furthermore, the battery pack 10 may drive the vehicle 1 by supplying power to a motor via an inverter of the vehicle 1 . Here, the battery pack 10 may include a battery management device 100 according to an embodiment of the present disclosure. That is, the vehicle 1 may include the battery management device 100.

[0120] Figure 7 is a diagram schematically illustrating a battery management method according to another embodiment of the present disclosure.

[0121] refer to Figure 7 , the battery management method may include a curve acquiring step ( S100 ), a peak determining step ( S200 ), a comparing step ( S300 ), a voltage determining step ( S400 ), and a degradation degree estimating step ( S500 ).

[0122] Preferably, each step of the battery management method may be performed by the battery management device 100. Hereinafter, for the convenience of description, descriptions shared with the aforementioned descriptions are omitted or briefly described.

[0123] The curve acquisition step ( S100 ) is a step of acquiring a differential curve indicating a corresponding relationship between the voltage and the differential capacity of the battery, and may be performed by the curve acquisition unit 110 .

[0124] The peak determination step ( S200 ) is a step of determining a target peak from among a plurality of peaks included in the differential curve and determining the remaining peaks except the target peak among the plurality of peaks as reference peaks, and may be performed by the control unit 120 .

[0125] For example, the control unit 120 may determine a peak having the highest corresponding voltage among a plurality of peaks included in the differential curve as the target peak.

[0126] For example, in Figure 2 In the embodiment, the control unit 120 may determine the peak P13 having the highest corresponding voltage among the multiple peaks P11, P12, P13 included in the first differential curve DP1 as the target peak, and determine the remaining peaks P11, P12 as reference peaks.

[0127] The comparison step ( S300 ) is a step of comparing the differential capacity of the target peak with the differential capacity of the reference peak, and may be performed by the control unit 120 .

[0128] Specifically, the control unit 120 may compare the differential capacity of the target peak with the differential capacity of the reference peak to determine which differential capacity is larger.

[0129] For example, in Figure 2 In the embodiment, the control unit 120 may compare the differential capacity of the target peak P13 with the differential capacities of the plurality of reference peaks P11 and P12 to determine which differential capacity is greater.

[0130] The voltage determination step ( S400 ) is a step of determining a voltage of interest based on the differential capacity comparison result, and may be performed by the control unit 120 .

[0131] Specifically, when the differential capacity of the target peak exceeds the differential capacity of the reference peak, the control unit 120 may determine the standard voltage as the voltage of interest. Conversely, when the differential capacity of the target peak is equal to or less than the differential capacity of the reference peak, the control unit 120 may determine the end-of-charge voltage set for the battery as the voltage of interest. Here, the standard voltage may be preset to a voltage lower than the end-of-charge voltage set for the battery.

[0132] More specifically, the standard voltage refers to the voltage of a standard battery. Here, the standard battery can be a reference battery corresponding to the battery or a battery at BOL. The standard differential curve is a differential curve obtained from the standard battery.

[0133] For example, the standard voltage may be preset as the voltage of the standard minimum point having the highest corresponding voltage among the plurality of minimum points included in the standard differential curve. Preferably, the standard minimum point may be preset as the minimum point having the highest corresponding voltage on the low voltage side of the standard peak corresponding to the target peak. Here, the standard peak may refer to the peak having the highest corresponding voltage among the plurality of peaks included in the standard differential curve.

[0134] For example, in Figure 2 In the embodiment, the differential capacity of target peak P13 exceeds the differential capacity of each of the multiple reference peaks P11 and P12. Therefore, control unit 120 may determine a preset standard voltage RV1 as the voltage of interest. Here, standard voltage RV1 may be preset to the voltage of the standard minimum point M12 having the highest corresponding voltage on the low voltage side of the standard peak R_pe corresponding to target peak P13 among the multiple minimum points M11, M12, and M13 included in the standard differential curve R_DP.

[0135] The degradation degree estimation step ( S500 ) is a step of estimating the degradation degree of the battery based on the capacity of interest corresponding to the voltage of interest of the battery, and may be performed by the control unit 120 .

[0136] Specifically, the control unit 120 may calculate the battery capacity of interest corresponding to the voltage of interest. Furthermore, the control unit 120 may estimate the degree of battery degradation by comparing the capacity of interest with a standard capacity. Here, the degree of battery degradation may refer to the difference between the standard capacity of the battery and the capacity of interest. Alternatively, the degree of battery degradation may refer to the ratio of the capacity of interest to the standard capacity of the battery. Here, the standard capacity of the battery is the capacity of a standard battery corresponding to the voltage of interest.

[0137] For example, in Figure 2 In the embodiment of the present invention, the control unit 120 can calculate the battery capacity of interest by integrating the first differential curve DP1 with respect to voltage up to the standard voltage RV1. The standard capacity is the value obtained by integrating the standard differential curve R_DP with respect to voltage up to the standard voltage RV. The control unit 120 can estimate the degree of battery degradation by comparing the capacity of interest obtained by integrating the first differential curve DP1 and the standard differential curve D_DP up to the standard voltage RV1 with the standard capacity.

[0138] The embodiments of the present disclosure as described herein are not only embodied by devices and methods, but can also be implemented by programs that execute functions corresponding to the exemplary configurations of the present disclosure or a recording medium on which the programs are recorded, and those skilled in the art can easily reach such implementation from the disclosure of the previously described embodiments.

[0139] Although the present disclosure has been described above with respect to a limited number of embodiments and drawings, the present disclosure is not limited thereto, and it will be apparent to those skilled in the art that various modifications and changes may be made thereto within the technical aspects of the present disclosure and the scope of the appended claims and their equivalents.

[0140] In addition, since those skilled in the art can make many substitutions, modifications and changes to the present disclosure as described above without departing from the technical aspects of the present disclosure, the present disclosure is not limited to the above-mentioned embodiments and drawings, and some or all of the embodiments can be selectively combined to allow various modifications.

[0141] [Reference Signs List]

[0142] 1: Vehicle

[0143] 10: Battery pack

[0144] 100: Battery management device

[0145] 110: Curve acquisition unit

[0146] 120: Control unit

[0147] 130: Storage unit

Claims

1. A battery management device, comprising: a curve acquiring unit configured to acquire a differential curve indicating a corresponding relationship between a voltage and a differential capacity of the battery; as well as A control unit configured to determine a target peak from among a plurality of peaks included in the differential curve, determine remaining peaks other than the target peak among the plurality of peaks as reference peaks, compare a differential capacity of the target peak with a differential capacity of the reference peak, determine a voltage of interest based on a result of the differential capacity comparison, and estimate a degree of degradation of the battery based on a capacity of interest of the battery corresponding to the voltage of interest.

2. The battery management device according to claim 1, in, The control unit is configured to: A peak having a highest corresponding voltage among the plurality of peaks is determined as the target peak.

3. The battery management device according to claim 1, in, The control unit is configured to: When the differential capacity of the target peak exceeds the differential capacity of the reference peak, a preset standard voltage is determined as the voltage of interest.

4. The battery management device according to claim 3, in, The standard voltage is preset as a voltage corresponding to a standard minimum point having a highest corresponding voltage among a plurality of minimum points included in a preset standard differential curve of the battery.

5. The battery management device according to claim 4, in, The standard minimum point is preset as a minimum point having the highest corresponding voltage on a low voltage side of a standard peak corresponding to the target peak.

6. The battery management device according to claim 4, in, The standard voltage is preset as a voltage of a standard peak corresponding to the target peak among the plurality of peaks included in the standard differential curve.

7. The battery management device according to claim 1, in, The control unit is configured to: When the differential capacity of the target peak is equal to or smaller than the differential capacity of the reference peak, the end-of-charge voltage of the battery is determined as the voltage of interest.

8. The battery management device according to claim 1, in, The control unit is configured to: estimating a difference between a preset standard capacity and the capacity of interest as the degree of degradation of the battery, and The standard capacity is a preset capacity corresponding to the voltage of interest.

9. The battery management device according to claim 1, in, The control unit is configured to: estimating a ratio of the capacity of interest to a preset standard capacity as the degree of degradation of the battery, and The standard capacity is a preset capacity corresponding to the voltage of interest.

10. The battery management device according to claim 1, in, The control unit is configured to: A usage condition of the battery is set based on the estimated degree of degradation of the battery.

11. A battery pack comprising the battery management device according to any one of claims 1 to 10.

12. A vehicle comprising the battery management device according to any one of claims 1-10.

13. A battery management method, comprising: a curve acquiring step of acquiring a differential curve indicating a corresponding relationship between a voltage and a differential capacity of the battery; a peak determining step of determining a target peak from among a plurality of peaks included in the differential curve, and determining remaining peaks other than the target peak among the plurality of peaks as reference peaks; a comparing step of comparing the differential capacity of the target peak with the differential capacity of the reference peak; a voltage determining step of determining a voltage of interest based on a result of the differential capacity comparison; as well as A degradation degree estimating step of estimating a degradation degree of the battery based on a capacity of interest of the battery corresponding to the voltage of interest.

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