Battery management device, battery pack, and battery management method

Abstract

An embodiment of the present invention provides a battery management device and method capable of non-destructively obtaining the positive and negative electrode curves of a battery cell by appropriately adjusting a pre-configured negative electrode curve. According to one aspect of the present disclosure, the adjusted negative electrode curve and battery curve of a degraded battery cell are used to easily estimate the positive electrode curve of the degraded battery cell in a non-destructive manner.

Description

Technical Field

[0001] This application claims priority from Korean Patent Application No. 10-2020-0102644 filed in Korea on August 14, 2020, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to battery management apparatus and methods, and more particularly to battery management apparatus and methods for generating a positive curve for a battery cell in a non-destructive manner. Background Art

[0003] Recently, demand for portable electronic products such as notebook computers, cameras, and portable phones has increased dramatically, and electric vehicles, energy storage batteries, robots, satellites, etc. have been developed. Therefore, high-performance battery cells that allow repeated charge and discharge are being actively researched.

[0004] Currently commercially available battery cells include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among them, lithium batteries have attracted attention because they have almost no memory effect compared to nickel-based batteries and also have a very low self-charging rate and high energy density.

[0005] Since battery cells degrade during use, various curves are required to accurately estimate the state of charge (SOC) and / or state of health (SOH) of a degraded battery cell. For example, providing a battery cell's battery curve, positive electrode curve, and negative electrode curve can most accurately analyze the battery cell's degradation.

[0006] Conventionally, to obtain the positive and negative electrode curves of a battery cell, the positive and negative electrodes are disassembled from the battery cell, cleaned, and then the positive and negative electrode half-cells are reassembled. The positive and negative electrode curves are then obtained from the reassembled positive and negative electrode half-cells, respectively, using an experimental method such as a three-electrode system. This process takes a considerable amount of time to obtain the positive and negative electrode curves, and in particular, there is the problem that when the battery cell is disassembled, it is exposed to the risk of explosion.

[0007] Therefore, there is a need to develop a technique for obtaining the negative electrode profile and / or the positive electrode profile of a battery cell in a fast and non-destructive manner. Summary of the Invention

[0008] Technical issues

[0009] The present disclosure is designed to solve the problems of the prior art, and thus the present disclosure is directed to providing a battery management device and method, which can obtain positive and negative electrode curves of a battery cell in a non-destructive manner by appropriately adjusting a preset negative electrode curve.

[0010] These and other purposes and advantages of the present disclosure can be understood from the following detailed description and will become more apparent from the exemplary embodiments of the present disclosure. Moreover, it will be readily understood that the purposes and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0011] Technical Solution

[0012] A battery management device according to one aspect of the present disclosure may include: a measuring unit configured to measure a voltage and a capacity of a battery cell; a curve generating unit configured to receive a voltage value of a voltage and a capacity value of a capacity from the measuring unit and generate a battery curve representing a corresponding relationship between the voltage value and the capacity value; a curve converting unit configured to receive the battery curve from the curve generating unit and convert the received battery curve into a battery differential curve representing a corresponding relationship between the capacity value and a differential voltage value with respect to the capacity value; and a control unit configured to determine at least one reference peak in the battery differential curve, having a negative electrode curve and a negative electrode differential curve preset for a negative electrode of the battery cell, adjusting the negative electrode differential curve so that at least one target peak preset for the negative electrode differential curve corresponds to the determined reference peak, adjusting the negative electrode curve to correspond to the adjusted negative electrode differential curve, and generating a positive electrode curve for the battery cell based on the adjusted negative electrode curve and the battery curve.

[0013] The control unit may be configured to determine a plurality of reference peaks in the battery differential curve, and adjust the negative electrode differential curve so that capacity values of a plurality of target peaks preset in the negative electrode differential curve are equal to capacity values of corresponding reference peaks.

[0014] The control unit may be configured to adjust the negative differential curve while changing an offset corresponding to a minimum capacity value of the negative differential curve and a scale representing an entire capacity interval of the negative differential curve.

[0015] The control unit may be configured to adjust the negative polar curve to correspond to the adjusted negative polar differential curve by applying change information of the offset and scale of the adjusted negative polar differential curve to the negative polar curve.

[0016] The control unit may be configured to generate the positive electrode curve by adding a voltage value of the battery curve and a voltage value of the adjusted negative electrode curve for each identical capacity value.

[0017] The control unit may be configured to select a first capacity interval and a second capacity interval from among the entire capacity interval of the battery curve, determine a first reference peak in the first capacity interval of the battery curve, and determine a second reference peak in the second capacity interval of the battery curve.

[0018] The control unit may be configured to determine a peak having a maximum differential voltage value and an instantaneous rate of change of a differential voltage value of a capacity value in a first capacity interval of the battery curve of zero as the first reference peak.

[0019] The control unit may be configured to determine a peak having an instantaneous rate of change of a differential voltage value of a capacity value in a second capacity interval of the battery curve of zero and a maximum differential voltage value as the second reference peak.

[0020] The negative electrode curve may be a curve preset to represent a corresponding relationship between the capacity value and the negative electrode voltage value of the battery cell.

[0021] The negative electrode differential curve may be a curve preset to represent a corresponding relationship between a capacity value and a differential negative electrode voltage value of a negative electrode voltage value with respect to the capacity value.

[0022] A battery pack according to another embodiment of the present disclosure may include the battery management apparatus according to an embodiment of the present disclosure.

[0023] According to another embodiment of the present disclosure, a battery management method may include: a measurement step of measuring the voltage and capacity of a battery cell; a battery curve generating step of generating a battery curve representing the corresponding relationship between the voltage value of the voltage measured in the measuring step and the capacity value of the capacity; a battery curve converting step of converting the battery curve into a battery differential curve representing the corresponding relationship between the capacity value and the differential voltage value with respect to the capacity value; a reference peak determining step of determining at least one reference peak in the battery differential curve; a negative electrode differential curve adjusting step of adjusting the negative electrode differential curve so that at least one target peak preset for the negative electrode differential curve of the battery cell provided in advance corresponds to the determined reference peak; a negative electrode curve adjusting step of adjusting the negative electrode curve of the battery cell provided in advance to correspond to the adjusted negative electrode differential curve; and a positive electrode curve generating step of generating a positive electrode curve of the battery cell based on the adjusted negative electrode curve and the battery curve.

[0024] Beneficial effects

[0025] According to one aspect of the present disclosure, by using the battery curve of the degraded battery cell and the adjusted negative electrode curve, there is an advantage that the positive electrode curve of the degraded battery cell can be easily estimated in a non-destructive manner.

[0026] In addition, according to one aspect of the present disclosure, since a battery curve, an adjusted negative electrode curve, and a positive electrode curve corresponding to each other can be provided, there is an advantage in that various data required for analyzing the state of a battery cell can be provided.

[0027] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not to be construed as being limited to the accompanying drawings.

[0029] Figure 1 is a diagram schematically showing a battery management apparatus according to an embodiment of the present invention.

[0030] Figure 2 is a diagram illustrating an exemplary configuration of a battery pack including a battery management apparatus according to an embodiment of the present disclosure.

[0031] Figure 3 is a diagram schematically illustrating a battery curve and a negative electrode curve according to an embodiment of the present disclosure.

[0032] Figure 4 is a diagram schematically illustrating a battery differential curve according to an embodiment of the present disclosure.

[0033] Figure 5 is a diagram schematically showing a negative electrode differential curve according to an embodiment of the present disclosure.

[0034] Figure 6 is a diagram schematically illustrating a battery curve, an adjusted negative electrode curve, and a generated positive electrode curve according to an embodiment of the present disclosure.

[0035] Figure 7 is a diagram schematically illustrating a battery differential curve and an adjusted negative electrode differential curve according to an embodiment of the present disclosure.

[0036] Figure 8 is a diagram schematically illustrating a battery management method according to another embodiment of the present invention. DETAILED DESCRIPTION

[0037] It should be understood that the terms used in the specification and the appended claims should not be interpreted 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 that the inventor is allowed to appropriately define the terms for the best interpretation.

[0038] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes only and are not intended to limit the scope of the present disclosure, and it should be understood that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0039] Additionally, in describing the present disclosure, when it is considered that the detailed description of related known elements or functions makes the key subject matter of the present disclosure unclear, the detailed description is omitted herein.

[0040] Terms including ordinal numbers such as “first,” “second,” etc. may be used to distinguish one element from another among various elements, but are not intended to limit the elements by the terms.

[0041] Throughout the specification, when a part is referred to as “including” or “comprising” any elements, it means that the part may further include other elements, but does not exclude other elements, unless explicitly stated otherwise.

[0042] In addition, the term "control unit" described in the specification refers 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.

[0043] In addition, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” with another element interposed therebetween.

[0044] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0045] Figure 1 is a schematic diagram of a battery management device 100 according to an embodiment of the present invention. Figure 2 is a diagram illustrating an exemplary configuration of a battery pack 10 including a battery management apparatus 100 according to an embodiment of the present disclosure.

[0046] Reference Figure 1 , the battery management device 100 may include a measuring unit 110 , a curve generating unit 120 , a curve converting unit 130 and a control unit 140 .

[0047] Here, the battery cell B refers to a physically separable independent unit including a negative terminal and a positive terminal. For example, a pouch-type lithium polymer battery can be regarded as a battery.

[0048] The measuring unit 110 may be configured to measure the voltage and capacity of the battery cell B.

[0049] Specifically, the measuring unit 110 may measure the voltage of the battery by respectively measuring the voltages at both ends of the battery cell B. Also, the measuring unit 110 may measure the current applied to the battery cell B and the charging time when the battery cell B is charged. Furthermore, the measuring unit 110 may measure the capacity of the battery cell B based on the measured current and charging time of the battery cell B.

[0050] For example, in Figure 2 In an embodiment, the measurement unit 110 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. The measurement unit 110 may measure the voltage of the battery cell B via the first sensing line SL1 and the second sensing line SL2. Furthermore, the measurement unit 110 may be connected to the current measurement unit A via the third sensing line SL3, and the current of the battery cell B may be measured via the current measurement unit A. Preferably, the measurement unit 110 may include a timer capable of measuring the charging time while measuring the current of the battery cell B.

[0051] The curve generating unit 120 may be configured to receive a voltage value (V) of the voltage and a capacity value (Q) of the capacity from the measuring unit 110. Here, the unit of the voltage value may be [V], and the unit of the capacity value may be [mAh].

[0052] The curve generation unit 120 may be connected to communicate with the measurement unit 110. For example, Figure 2 In the embodiment of the present invention, the curve generating unit 120 may be connected to the measuring unit 110 to receive the measured voltage value and the measured capacity value of the battery cell B from the measuring unit 110 .

[0053] In addition, the curve generating unit 120 may be configured to generate a battery curve (Pb) indicating a corresponding relationship between a voltage value and a capacity value.

[0054] Specifically, the battery curve (Pb) may be a curve configured to represent a corresponding relationship between a voltage value and a capacity value of the battery cell B simultaneously measured by the measurement unit 110 .

[0055] Figure 3 Schematically shows a battery curve (Pb) and a negative electrode curve (Pa1) according to an embodiment of the present disclosure. Figure 3 Schematically shows the battery curve (Pb) and the negative electrode curve (Pa1) in the form of a graph. Specifically, Figure 3 is a diagram schematically showing an XY graph when a capacity value is set to X and a voltage value is set to Y.

[0056] The curve conversion unit 130 may be configured to receive the battery curve (Pb) from the curve generation unit 120 .

[0057] For example, in Figure 3 In an embodiment, the curve conversion unit 130 may be communicatively connected to the curve generation unit 120 and may receive the battery curve (Pb) from the curve generation unit 120 .

[0058] Furthermore, the curve conversion unit 130 may be configured to convert the received battery curve (Pb) into a battery differential curve (Pb_d) representing a corresponding relationship between a capacity value and a differential voltage value (dV / dQ) of the capacity value. Here, the differential voltage value is a value obtained by differentiating the voltage value with respect to the capacity value of battery cell B and may be expressed as "dV / dQ" with a unit of [V / mAh]. In other words, the differential voltage value may be a value representing an instantaneous rate of change of the voltage value with respect to the capacity value of battery cell B.

[0059] Specifically, the curve conversion unit 130 may convert the battery curve (Pb) representing the correspondence between the capacity value and the voltage value of the battery cell B into a battery differential curve (Pb_d) representing the correspondence between the capacity value and the voltage difference value of the battery cell B.

[0060] Figure 4 Schematically shows a battery differential curve (Pb_d) according to an embodiment of the present disclosure. Here, Figure 4 is a graph showing the battery differential curve (Pb_d) in a graphical form. Specifically, Figure 4 is a diagram schematically showing an XY graph when the capacity value of the battery cell B is set to X and the differential voltage value of the battery cell B is set to Y.

[0061] The control unit 140 may be configured to determine at least one reference peak in the battery differential curve (Pb_d).

[0062] Preferably, the control unit 140 may be configured to determine a plurality of reference peaks in the battery differential curve (Pb_d). More preferably, the control unit 140 may be configured to determine two reference peaks in the battery differential curve (Pb_d).

[0063] First, the control unit 140 may be configured to select a first capacity interval and a second capacity interval among the entire capacity intervals of the battery curve (Pb).

[0064] Here, the first capacity interval and the second capacity interval may be preset so as not to overlap with each other. Preferably, information about the first capacity interval and the second capacity interval may be pre-stored in the control unit 140 and / or the storage unit 150 .

[0065] Specifically, the first capacity interval and the second capacity interval may be capacity intervals set in consideration of the electrochemical characteristics of the battery. That is, in a battery differential curve (Pb_d) based on the voltage value and capacity value of battery cell B obtained when battery cell B is charged, a predetermined capacity interval in which a first reference peak (RP1) may appear may be set as the first capacity interval, and a predetermined capacity interval in which a second reference peak (RP2) may appear may be set as the second capacity interval.

[0066] More specifically, in the entire capacity interval of the negative half-cell of the BOL battery unit B, the first capacity interval can be set from the lowest capacity value to a predetermined first interval so as to include the capacity value of the first reference peak (RP1). Figure 4 In an embodiment, the first capacity interval may be preset as the interval from "min" to "min+{(max1-min)×0.3}" in the entire capacity interval (min to max1 interval). Here, min may be the minimum capacity value of the entire capacity interval, and max may be the maximum capacity value of the entire capacity interval.

[0067] In the entire capacity interval of the negative half-cell of the BOL battery unit B, the second capacity interval can be set to a predetermined second interval so as to include the capacity value of the second reference peak (RP2). Figure 4 In the embodiment, the second capacity interval may be preset as an interval from "min+{(max1-min)×0.4}" to "min+{(max1-min)×0.6}" in the entire capacity interval (min to max1 interval).

[0068] Next, the control unit 140 may be configured to determine a first reference peak ( RP1 ) in a first capacity interval of the battery curve (Pb) and determine a second reference peak ( RP2 ) in a second capacity interval of the battery curve (Pb).

[0069] Specifically, the control unit 140 may be configured to determine a peak having a maximum differential voltage value and an instantaneous rate of change of the differential voltage value of the capacity value in the first capacity interval of the battery curve (Pb) as the first reference peak (RP1). Furthermore, the control unit 140 may be configured to determine a peak having a maximum differential voltage value and an instantaneous rate of change of the differential voltage value of the capacity value in the second capacity interval of the battery curve (Pb) as the second reference peak (RP2).

[0070] In summary, the reference peak may be a peak whose instantaneous rate of change of the differential voltage value of the capacity value is 0 and whose differential voltage value is the largest in each of the first capacity interval and the second capacity interval. In addition, the instantaneous rate of change of the low capacity based on the reference peak (the instantaneous rate of change of the differential voltage value of the capacity value) may be positive, and the instantaneous rate of change of the high capacity based on the reference peak may be negative. That is, the reference peak may be a point having an upward convex shape in the XY graph. For example, in Figure 4 In an embodiment of the present invention, the control unit 140 may determine a first reference peak (RP1) in the first capacity interval. In addition, the control unit 140 may determine a second reference peak (RP2) in the second capacity interval.

[0071] The control unit 140 may be configured to have a negative electrode curve ( Pa1 ) and a negative electrode differential curve ( Pa_d1 ) preset for the negative electrode of the battery cell B.

[0072] Here, the negative electrode curve (Pa1) may be a curve preset to represent the corresponding relationship between the capacity value and the negative electrode voltage value of the battery cell B. Specifically, the negative electrode curve (Pa1) may represent the corresponding relationship between the capacity value of the battery cell B and the negative electrode voltage value of the battery cell B measured during the charging process of the battery cell B in the BOL state. In other words, the negative electrode curve (Pa1) may be a curve of the negative electrode battery in the BOL state.

[0073] For example, in Figure 3 In the embodiment of the present invention, the negative electrode curve Pa1 is a curve showing the corresponding relationship between the capacity value and the voltage value of the negative electrode half-cell. In contrast, the battery curve (Pb) is a curve showing the corresponding relationship between the capacity value and the voltage value of the full battery unit.

[0074] Figure 5 is a diagram schematically illustrating a negative electrode differential curve (Pa_d1) according to an embodiment of the present disclosure.

[0075] In addition, the negative electrode differential curve (Pa_d1) may be a curve that is preset to represent the corresponding relationship between the capacity value and the negative electrode voltage value that is a differential of the negative electrode voltage value with respect to the capacity value.

[0076] Specifically, Figure 5 The negative differential curve (Pa_d1) is obtained by converting Figure 3 The negative electrode curve (Pa1) is a curve obtained by expressing the correspondence between the capacity value and the differential voltage value. More specifically, as Figure 5The negative differential curve (Pa_d1) of the battery cell B in the BOL state is a diagram schematically showing an XY graph when the capacity value is set to X and the differential voltage value is set to Y. That is, the negative differential curve (Pa_d1) may be a differential curve of the negative battery in the BOL state.

[0077] For example, the negative polarity curve (Pa1) and the negative polarity differential curve (Pa_d1) may be pre-stored in the storage unit 150, and the control unit 140 may access the storage unit 150 to obtain the negative polarity curve (Pa1) and the negative polarity differential curve (Pa_d1). As another example, the negative polarity curve (Pa1) and the negative polarity differential curve (Pa_d1) may be pre-set and stored in the internal memory of the control unit 140.

[0078] The control unit 140 may be configured to adjust the negative polar differential curve ( Pa_d1 ) so that at least one target peak preset for the negative polar differential curve ( Pa_d1 ) corresponds to the determined reference peak.

[0079] For example, in Figure 5 In an embodiment, the first target peak (TP1) and the second target peak (TP2) may be preset in the negative electrode differential curve (Pa_d1). In addition, the control unit 140 may adjust the negative electrode differential curve (Pa_d1) so that the first target peak (TP1) and the second target peak (TP2) correspond to the first reference peak (RP1) and the second reference peak (RP2) of the battery differential curve (Pb_d), respectively.

[0080] The control unit 140 may be configured to adjust the negative electrode curve Pa1 to correspond to the adjusted negative electrode differential curve.

[0081] Specifically, the control unit 140 may adjust the negative polarity curve (Pa1) by applying the conversion information of the adjusted negative polarity differential curve to the negative polarity curve (Pa1).

[0082] The control unit 140 may be configured to generate a positive electrode profile of the battery cell B based on the adjusted negative electrode profile (Pa2) and the battery profile (Pb).

[0083] Figure 6 Schematically illustrates a battery curve (Pb), an adjusted negative electrode curve (Pa2), and a generated positive electrode curve (Pc) according to an embodiment of the present disclosure. Figure 6 The graph shows the battery curve (Pb), the adjusted negative electrode curve (Pa2), and the generated positive electrode curve (Pc) in a graphical form. Specifically, Figure 6 is a diagram schematically showing an XY graph when a capacity value is set to X and a voltage value is set to Y.

[0084] When battery cell B is degraded, the battery curve (Pb) may be the degradation curve of the degraded battery cell B. By adjusting the negative differential curve (Pa_d1) of battery cell B in the BOL state by the control unit 140, the negative differential curve (Pa1) may be adjusted to correspond to the degradation curve. Therefore, the control unit 140 may generate a positive differential curve (Pc) corresponding to the current state of battery cell B based on the battery curve (Pb) of the degraded battery cell B and the adjusted negative differential curve (Pa2).

[0085] For example, assume that battery cell B has deteriorated by 10% compared to the BOL state. The battery curve (Pb) generated by the curve generation unit 120 may be a curve for battery cell B that has deteriorated by 10%. Furthermore, the negative electrode curve (Pa2) adjusted by the control unit 140 may be a negative electrode curve for battery cell B that has deteriorated by 10%. Therefore, the control unit 140 may generate a positive electrode curve (Pc) for the battery cell that has deteriorated by 10% based on the battery curve (Pb) and the adjusted negative electrode curve (Pa2).

[0086] Specifically, as described above, in the prior art, the positive and negative electrodes are disassembled from battery cell B, the positive and negative electrodes are reassembled for sampling, and the positive and negative electrode curves are obtained based on the reassembled positive and negative electrodes, respectively. This process takes a considerable amount of time and poses a risk of explosion of battery cell B while it is disassembled.

[0087] At the same time, considering that the shape of the negative electrode curve (Pa1) remains constant even if the battery cell B deteriorates, the battery management device 100 according to the embodiment of the present disclosure has the advantage of easily estimating the positive electrode curve (Pc) of the deteriorated battery cell B by using the battery curve (Pb) of the deteriorated battery cell B and the adjusted negative electrode curve (Pa2).

[0088] That is, even if battery cell B degrades, the negative electrode curve (Pa1) can maintain a constant graph shape. However, since the graph shape changes as battery cell B degrades, there is a problem in that the positive electrode curve (Pc) may not be easily estimated using only the battery curve (Pb). Therefore, the battery management device 100 can easily estimate the positive electrode curve (Pc) by using the battery curve (Pb) and the adjusted negative electrode curve (Pa2).

[0089] In addition, according to an embodiment of the present disclosure, the positive electrode curve (Pc) of the battery cell B can be estimated in a non-destructive manner. Therefore, the battery management device 100 has the advantage of estimating the positive electrode curve (Pc) of the battery cell B installed in the battery pack 10, electric vehicle, energy storage device, etc. in a non-destructive manner.

[0090] Meanwhile, the control unit 140 provided to the battery management device 100 may selectively include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the art, to execute the various control logics implemented in the present disclosure. Moreover, when the control logic is implemented in software, the control unit 140 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 140. The memory may be located inside or outside the control unit 140 and may be connected to the control unit 140 in various well-known ways.

[0091] Furthermore, the storage unit 150 can store programs and data required for the battery management device 100 to generate the positive electrode curve Pc. Specifically, the storage unit 150 can store data required for the operation and function of each component of the battery management device 100, as well as data generated during the execution of operations or functions. The type of storage unit 150 is not particularly limited, as long as it is a known information storage device that can record, erase, update, and read data. Examples of information storage devices include RAM, flash memory, ROM, EEPROM, registers, and the like. Furthermore, the storage unit 150 can store program code that defines the processes executable by the curve generation unit 120, curve conversion unit 130, and control unit 140.

[0092] For example, the storage unit 150 may store a preset negative electrode curve (Pa1) and a negative electrode differential curve (Pa_d1). In this case, the control unit 140 may access the storage unit 150 and obtain the negative electrode curve (Pa1) and the negative electrode differential curve (Pa_d1) to generate the positive electrode curve (Pc). In addition, the battery curve (Pb) generated by the curve generation unit 120, the negative electrode curve (Pa2) adjusted by the control unit 140, and the positive electrode curve (Pc) generated by the control unit 140 may be mapped to each other and stored in the storage unit 150. Therefore, the battery management device 100 has the advantage of providing the battery curve (Pb), the adjusted negative electrode curve (Pa2), and the positive electrode curve (Pc) that correspond to each other.

[0093] Hereinafter, more specific embodiments of the first capacity interval and the second capacity interval will be described in consideration of the characteristics of the battery cell B.

[0094] Specifically, in Figure 5 In an embodiment, the first target peak (TP1) and the second target peak (TP2) included in the negative electrode differential curve (Pa_d1) may be related to a step-forming phenomenon of extracting lithium ions during a discharge process.

[0095] Typically, when battery cell B is discharged, a generation process is performed to extract lithium ions contained between graphite layers. The generation process during discharge progresses from a high stage to a low stage according to the lithium ion extraction reaction. For example, during discharge, the generation process proceeds in the order of Stage IV, Stage III, Stage II, and Stage I.

[0096] For example, in Figure 5 In an embodiment, the capacity (b1) of the first target peak (TP1) included in the negative electrode differential curve (Pa_d1) may correspond to the negative electrode capacity when the stage III state is progressing. Specifically, when the coexisting stage II and stage III states are converted to the stage III state, the capacity (b1) of the first target peak (TP1) may correspond to the negative electrode capacity.

[0097] In addition, Figure 5 In an embodiment, the capacity (b2) of the second target peak (TP2) included in the negative electrode differential curve (Pa_d1) may correspond to the negative electrode capacity when the stage II state is progressing. Specifically, when the coexisting stage I and stage II states are converted to the stage II state, the capacity (b2) of the second target peak (TP2) may correspond to the negative electrode capacity.

[0098] Furthermore, due to the characteristics of battery cell B, even if battery cell B degrades, the capacities corresponding to the first target peak (TP1) and the second target peak (TP2) may not change significantly. Furthermore, depending on the degree of degradation of battery cell B, the capacity of each of the first reference peak (RP1) and the second reference peak (RP2) may be the same as or similar to the capacity of the first target peak (TP1) and the second target peak (TP2).

[0099] Therefore, the first capacity interval is the capacity interval in which the first reference peak (RP1) is expected to appear, and can be set to take into account the capacity of the first target peak (TP1). Similarly, the second capacity interval is the capacity interval in which the second reference peak (RP2) is expected to appear, and can be set to take into account the capacity of the second target peak (TP2).

[0100] For example, in Figure 4 In an embodiment, the first capacity interval may be set to a capacity interval of 0Q to 30Q within the entire capacity interval (min to max1 interval) of the negative half-cell of the BOL battery cell B. Furthermore, the second capacity interval may be set to a capacity interval of 40Q to 60Q within the entire capacity interval (min to max1 interval) of the negative half-cell of the BOL battery cell B. Here, the unit of capacity (Q) may be [mAh], for example.

[0101] Figure 72 is a diagram schematically illustrating a battery differential curve (Pb_d) and an adjusted negative electrode differential curve (Pa_d2) according to an embodiment of the present disclosure.

[0102] The control unit 140 may be configured to determine a plurality of reference peaks in the battery differential curve (Pb_d).

[0103] For example, the control unit 140 may determine two reference peaks in the battery differential curve (Pb_d). In this case, the control unit 140 may determine a first reference peak (RP1) in a first capacity interval of the battery differential curve (Pb_d) and a second reference peak (RP2) in a second capacity interval.

[0104] In addition, the control unit 140 may be configured to adjust the negative differential curve ( Pa_d1 ) so that the capacity values of the plurality of target peaks preset in the negative differential curve ( Pa_d1 ) are equal to the capacity values of the corresponding reference peaks.

[0105] Specifically, the control unit 140 may adjust the negative electrode differential curve (Pa_d1) so that the capacity values of the corresponding reference peak and target peak become the same. In other words, the control unit 140 may adjust the negative electrode differential curve (Pa_d1) according to the battery differential curve (Pb_d).

[0106] Preferably, the control unit 140 may be configured to adjust the negative differential curve ( Pa_d1 ) while changing an offset corresponding to a minimum capacity value of the negative differential curve ( Pa_d1 ) and a scale representing the entire capacity range of the negative differential curve ( Pa_d1 ).

[0107] refer to Figure 5 The offset can represent the minimum capacity value (min) at the beginning of the negative differential curve (Pa_d1). In addition, the scale can represent the entire capacity range (min to max1 range) of the negative differential curve (Pa_d1).

[0108] For example, refer to Figure 5 and Figure 7 , the control unit 140 can adjust Figure 5 The scale of the negative differential curve (Pa_d1) is used to generate Figure 7negative electrode differential curve (Pa_d2). That is, the capacity value of the first target peak (TP1) included in the negative electrode differential curve (Pa_d1) may be b1 [mAh], the capacity value of the second target peak (TP2) may be b2 [mAh], the minimum capacity value may be min [mAh], and the maximum capacity value may be max1 [mAh]. The capacity value of the first target peak (TP1) included in the adjusted negative electrode differential curve (Pa_d2) may be a1 [mAh], the capacity value of the second target peak (TP2) may be a2 [mAh], the minimum capacity value may be min [mAh], and the maximum capacity value may be max2 [mAh]. Here, assuming that a1 [mAh] and b1 [mAh] are different values and a2 [mAh] and b2 [mAh] are different values, max1 [mAh] and max2 [mAh] may also be different values.

[0109] As described above, even if the battery cell B degrades, the shape of the negative electrode curve (Pa1) of the battery cell B can be maintained. That is, the scale and offset of the negative electrode curve of the degraded battery cell B can be changed compared to the negative electrode curve (Pa1) of the battery cell B in the BOL state, but the original shape can be maintained.

[0110] For example, since the negative electrode curve of the degraded battery cell B can change in terms of the minimum capacity value and / or size of the entire capacity interval in the negative electrode curve (Pa1) of the battery cell B in the BOL state, the shape of the negative electrode curve (Pa1) can be maintained even if the battery cell B degrades. In other words, even if the battery cell B degrades, only the scale of a portion of the entire capacity interval of the negative electrode curve (Pa1) does not change, and the scale of the entire capacity interval of the negative electrode curve (Pa1) as a whole changes, so that even if the battery cell B degrades, the shape of the negative electrode curve (Pa1) can be maintained.

[0111] Therefore, the control unit 140 may adjust the negative differential curve ( Pa_d1 ) by adjusting the offset and scale of the negative differential curve ( Pa_d1 ) so that the capacity value of the target peak becomes equal to the capacity value of the corresponding reference peak.

[0112] Then, the control unit 140 may be configured to adjust the negative polarity curve (Pa1) to correspond to the adjusted negative polarity differential curve (Pa_d2) by applying the change information of the offset and scale of the adjusted negative polarity differential curve (Pa_d2) to the negative polarity curve (Pa1). In other words, the adjusted negative polarity curve (Pa2) may be generated by adjusting the offset and scale of the negative polarity curve (Pa1) to correspond to the offset and scale of the adjusted negative polarity differential curve (Pa_d2) by the control unit 140.

[0113] The control unit 140 may be configured to generate the positive electrode curve (Pc) by adding the voltage value of the battery curve (Pb) and the voltage value of the adjusted negative electrode curve (Pa2) for each identical capacity value.

[0114] Typically, a battery curve can be generated based on the difference between the positive and negative curves. By applying this in reverse, the control unit 140 can generate a positive curve (Pc) by adding the battery curve (Pb) and the adjusted negative curve (Pa2).

[0115] For example, in Figure 6 In an embodiment, when the capacity value is S [mAh], the voltage value of the battery curve (Pb) may be Vb [V], and the voltage value of the adjusted negative electrode curve (Pa2) may be Va [V]. The control unit 140 may generate a positive electrode curve (Pc) having a voltage value of Vc [V] at a capacity value of S [mAh] by calculating the formula "Vb + Va". In this manner, the control unit 140 may generate the positive electrode curve (Pc) by adding the voltage value of the battery curve (Pb) and the voltage value of the adjusted negative electrode curve (Pa2) for the entire capacity range of the battery curve (Pb).

[0116] The battery management device 100 according to an embodiment of the present disclosure has the advantage of non-destructively estimating the adjusted negative electrode curve (Pa2) and positive electrode curve (Pc) corresponding to the current state of the battery cell B. That is, even when the battery cell B is installed in the battery pack 10 or the like, the battery curve (Pb), the adjusted negative electrode curve (Pa2), and the positive electrode curve (Pc) can be generated separately and non-destructively. Therefore, the battery management device 100 has the advantage of providing various information for analyzing the cause and degree of degradation of the battery cell B.

[0117] The battery management device 100 according to the present disclosure can be applied to a BMS (battery management system). That is, the BMS according to the present disclosure can include the battery management device 100. In this configuration, at least some components of the battery management device 100 can be implemented by supplementing or adding the functions of components included in a conventional BMS. For example, the measurement unit 110, curve generation unit 120, curve conversion unit 130, control unit 140, and storage unit 150 of the battery management device 100 can be implemented as components of the BMS.

[0118] In addition, the battery management device 100 may be provided to the battery pack 10. That is, the battery pack 10 according to the present disclosure may include the battery management device 100 described above and at least one battery cell B. In addition, the battery pack 10 may further include electrical devices (relays, fuses, etc.), a housing, etc.

[0119] For example, in Figure 2 In an embodiment, the battery pack 10 may include a battery cell B and a battery management device 100. In addition, the charge and discharge unit 200 may be connected to the positive terminal (P+) and the negative terminal (P-) of the battery pack 10 to charge or discharge the battery cell B. As another example, in Figure 2 In the embodiment, the battery cell B, the battery management device 100 , and the charge and discharge unit 200 may all be included in the battery pack 10 .

[0120] Figure 8 is a schematic diagram of a battery management method according to another embodiment of the present invention.

[0121] Each step of the battery management method may be performed by the battery management apparatus 100. Hereinafter, for the convenience of description, it should be noted that contents overlapping with previously described contents will be briefly described or omitted.

[0122] Reference Figure 8 According to another embodiment of the present disclosure, a battery management method may include a measuring step (S100), a battery curve generating step (S200), a battery curve converting step (S300), a reference peak determining step (S400), a negative electrode differential curve adjusting step (S500), a negative electrode curve adjusting step (S600), and a positive electrode curve generating step (S700).

[0123] The measuring step ( S100 ) is a step of measuring the voltage and capacity of the battery cell B, and may be performed by the measuring unit 110 .

[0124] For example, in Figure 2 In an embodiment, the measuring unit 110 may use the first sensing line SL1 and the second sensing line SL2 to measure the voltage of the battery cell B. In addition, the measuring unit 110 may use the third sensing line SL3 to measure the current of the battery cell B, and may measure the capacity of the battery cell B based on the measurement time and the measured current.

[0125] The battery curve generating step ( S200 ) is a step of generating a battery curve (Pb) indicating a corresponding relationship between a voltage value of the voltage measured in the measuring step ( S100 ) and a capacity value of the capacity measured in the measuring step ( S100 ), and may be performed by the curve generating unit 120 .

[0126] For example, in Figure 3 In an embodiment, the curve generating unit 120 may receive the voltage value and the capacity value of the battery cell B from the measuring unit 110 and generate a battery curve (Pb) indicating a corresponding relationship between the voltage value and the capacity value corresponding to each other.

[0127] The battery curve conversion step ( S300 ) is a step of converting the battery curve (Pb) into a battery differential curve (Pb_d) representing a correspondence relationship between a capacity value and a differential voltage value with respect to the capacity value, and may be performed by the curve conversion unit 130 .

[0128] For example, refer to Figure 3 and Figure 4 The curve conversion unit 130 can convert the curve generated by the curve generation unit 120 into Figure 3 The battery curve (Pb) is converted into Figure 4 Battery differential curve (Pb_d).

[0129] The reference peak determining step ( S400 ) is a step of determining at least one reference peak in the battery differential curve (Pb_d), and may be performed by the control unit 140 .

[0130] Specifically, the control unit 140 may determine a plurality of reference peaks in the battery differential curve (Pb_d).

[0131] For example, when the control unit 140 determines two reference peaks, the control unit 140 may determine a first reference peak ( RP1 ) in a first capacity interval of the battery differential curve (Pb_d) and determine a second reference peak ( RP2 ) in a second capacity interval.

[0132] The negative differential curve adjustment step ( S500 ) is a step of adjusting the negative differential curve ( Pa_d1 ) so that at least one target peak preset for the negative differential curve ( Pa_d1 ) of the battery cell B provided in advance corresponds to the determined reference peak, and can be performed by the control unit 140 .

[0133] Reference Figure 5 and Figure 7 , the control unit 140 can be adjusted by including Figure 5 The first target peak (TP1) and the second target peak (TP2) in the negative differential curve (Pa_d1) are generated by corresponding to the first reference peak (RP1) and the second reference peak (RP2) respectively. Figure 7 The adjusted negative electrode differential curve (Pa_d2) is shown in FIG. That is, the capacity value of the first target peak (TP1) can be changed from b1 [mAh] to a1 [mAh], and the capacity value of the second target peak (TP2) can be changed from b2 [mAh] to a2 [mAh]. In addition, the maximum capacity value of the adjusted negative electrode differential curve (Pa_d2) can be max2 [mAh]. Here, assuming that a1 [mAh] and b1 [mAh] are different and a2 [mAh] and b2 [mAh] are different, max1 [mAh] and max2 [mAh] can also be different values.

[0134] The negative electrode curve adjustment step ( S600 ) is a step of adjusting the previously provided negative electrode curve ( Pa1 ) of the battery cell B to correspond to the adjusted negative electrode differential curve ( Pa_d2 ), and may be performed by the control unit 140 .

[0135] The control unit 140 may adjust the negative polarity curve (Pa1) to correspond to the adjusted negative polarity differential curve (Pa_d2) by applying the offset change information and scale change information of the adjusted negative polarity differential curve (Pa_d2) to the negative polarity curve (Pa1). Thus, the adjusted negative polarity curve (Pa2) corresponding to the negative polarity differential curve (Pa_d2) may be generated.

[0136] The positive electrode curve generating step ( S700 ) is a step of generating a positive electrode curve (Pc) of the battery cell B based on the adjusted negative electrode curve ( Pa2 ) and the battery curve (Pb), and may be performed by the control unit 140 .

[0137] The control unit 140 may generate the positive electrode curve (Pc) by adding voltage values of the battery curve (Pb) and the adjusted negative electrode curve (Pa2) having the same capacity value.

[0138] In other words, the battery management method according to another embodiment of the present disclosure can obtain the adjusted negative electrode curve (Pa2) and positive electrode curve (Pc) for the current state of the battery cell B based on the battery curve (Pb) without disassembling the battery cell B. Therefore, according to the battery management method, since the battery curve (Pb), the adjusted negative electrode curve (Pa2), and the positive electrode curve (Pc) can all be provided, various analysis data of the battery cell B can be provided.

[0139] The embodiments of the present disclosure described above may be implemented not only by devices and methods, but also by programs that implement functions corresponding to the configurations of the embodiments of the present disclosure or recording media that record the programs. Based on the above description of the embodiments, those skilled in the art can easily implement the programs or recording media.

[0140] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, as various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

[0141] In addition, without departing from the technical aspects of the present disclosure, those skilled in the art may make many substitutions, modifications and changes to the present disclosure, and the present disclosure is not limited to the above-mentioned embodiments and drawings, and each embodiment may be selectively combined in part or in whole to allow various modifications.

[0142] (reference numerals)

[0143] 10: Battery pack

[0144] 100: Battery management equipment

[0145] 110: Measurement unit

[0146] 120: Curve generation unit

[0147] 130: Curve conversion unit

[0148] 140: Control unit

[0149] 150: Storage unit

[0150] 200: Charge and discharge unit

[0151] B: Battery cell

Claims

1. A battery management device, comprising: a measuring unit configured to measure a voltage and a capacity of a battery cell; a curve generating unit configured to receive the voltage value of the voltage and the capacity value of the capacity from the measuring unit, and generate a battery curve indicating a corresponding relationship between the voltage value and the capacity value; a curve conversion unit configured to receive the battery curve from the curve generation unit and convert the received battery curve into a battery differential curve representing a corresponding relationship between the capacity value and a differential voltage value with respect to the capacity value; as well as A control unit is configured to determine at least one reference peak in the battery differential curve, having a negative electrode curve and a negative electrode differential curve preset for the negative electrode of the battery cell, adjust the negative electrode differential curve so that at least one target peak preset for the negative electrode differential curve corresponds to the determined reference peak, adjust the negative electrode curve to correspond to the adjusted negative electrode differential curve, and generate a positive electrode curve for the battery cell based on the adjusted negative electrode curve and the battery curve.

2. The battery management device according to claim 1, wherein: The control unit is configured to determine a plurality of reference peaks in the battery differential curve and adjust the negative electrode differential curve so that capacity values of a plurality of target peaks preset in the negative electrode differential curve are equal to capacity values of corresponding reference peaks.

3. The battery management device according to claim 2, wherein: The control unit is configured to adjust the negative differential curve while changing an offset corresponding to a minimum capacity value of the negative differential curve and a scale representing an entire capacity interval of the negative differential curve.

4. The battery management device according to claim 3, wherein: The control unit is configured to adjust the negative polar curve to correspond to the adjusted negative polar differential curve by applying change information of the offset and scale of the adjusted negative polar differential curve to the negative polar curve. The battery management device according to claim 1 , wherein: The control unit is configured to generate the positive electrode curve by adding a voltage value of the battery curve and a voltage value of the adjusted negative electrode curve for each identical capacity value. The battery management device according to claim 1 , wherein: The control unit is configured to select a first capacity interval and a second capacity interval in the entire capacity interval of the battery curve, determine a first reference peak in the first capacity interval of the battery curve, and determine a second reference peak in the second capacity interval of the battery curve.

7. The battery management device according to claim 6, wherein: The first capacity interval and the second capacity interval are preset to not overlap with each other.

8. The battery management device according to claim 7, wherein: The first capacity interval is preset as the interval from min to min+{(max1-min)×0.3} in the entire capacity interval, and the second capacity interval is preset as the interval from min+{(max1-min)×0.4} to min+{(max1-min)×0.6} in the entire capacity interval. Wherein, min is the minimum capacity value of the entire capacity interval, and max is the maximum capacity value of the entire capacity interval.

9. The battery management device according to claim 8, wherein: The control unit is configured to determine a peak whose instantaneous rate of change of the differential voltage value of the capacity value in the first capacity interval of the battery curve is 0 and whose differential voltage value is the largest as the first reference peak, The control unit is configured to determine a peak whose instantaneous rate of change of the differential voltage value of the capacity value in the second capacity interval of the battery curve is 0 and whose differential voltage value is the largest as the second reference peak.

10. The battery management device according to claim 1, wherein: The negative electrode curve is a curve preset to represent the corresponding relationship between the capacity value and the negative electrode voltage value of the battery cell. The negative electrode differential curve is a curve preset to represent a corresponding relationship between a capacity value and a differential negative electrode voltage value of a negative electrode voltage value with respect to the capacity value. 11 . A battery pack comprising the battery management device according to claim 1 .

12. A battery management method, comprising: A measurement step for measuring the voltage and capacity of a battery cell; a battery curve generating step of generating a battery curve indicating a corresponding relationship between the voltage value of the voltage measured in the measuring step and the capacity value of the capacity; a battery curve conversion step of converting the battery curve into a battery differential curve representing a corresponding relationship between the capacity value and a differential voltage value with respect to the capacity value; a reference peak determining step of determining at least one reference peak in the battery differential curve; a negative electrode differential curve adjusting step of adjusting the negative electrode differential curve so that at least one target peak preset for the negative electrode differential curve of the battery cell provided in advance corresponds to the determined reference peak; a negative electrode curve adjustment step of adjusting a pre-provided negative electrode curve of the battery cell to correspond to the adjusted negative electrode differential curve; and A positive electrode curve generating step is performed to generate a positive electrode curve of the battery cell based on the adjusted negative electrode curve and the battery curve.

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