Battery management device and battery management method, battery pack, and battery manufacturing apparatus

Abstract

A battery management device according to an embodiment of the present application includes a charging unit configured to charge a battery cell, a measuring unit configured to measure a voltage and a current of the battery cell, and a control unit configured to receive battery information including the voltage and the current from the measuring unit, estimate an SOC of the battery cell based on the received battery information, calculate an internal resistance of the battery cell based on the battery information each time the SOC of the battery cell increases by a standard amount, compare a change pattern of the calculated internal resistance with a predetermined standard pattern, and set a negative electrode capacity of the battery cell based on a comparison result.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0160345, filed in Korea on November 25, 2020, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a battery management device and method, and more specifically, to a battery management device and method capable of setting the negative electrode capacity of a battery cell. Background Technology

[0003] Recently, demand for portable electronic products such as laptops, cameras, and mobile phones has increased dramatically, and electric vehicles, energy storage batteries, robots, and satellites have seen significant development. Therefore, high-performance batteries that allow for repeated charging and discharging are being actively researched.

[0004] Currently available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. 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-charge rate and high energy density.

[0005] When such a battery is overcharged, lithium metal may deposit on the negative electrode of the battery, and there is a problem that internal short circuits may occur between the positive and negative electrodes of the battery due to the deposited lithium metal.

[0006] Typically, when designing batteries, the metric used to compare how much free space of lithium is ensured in the negative electrode compared to the positive electrode is called the N / P ratio. In other words, the N / P ratio can be considered as the ratio of the battery's negative electrode capacity to its positive electrode capacity.

[0007] To prevent lithium plating, the N / P ratio of the battery is designed to be greater than 1 (or 100%). However, even with an N / P ratio designed to be greater than 1 (or 100%), the optimal N / P ratio may deviate from the design value due to the battery activation process and degradation. Therefore, to improve battery stability, it is crucial to set the optimal N / P ratio and optimal negative electrode capacity through actual measurements. Summary of the Invention

[0008] Technical issues

[0009] This disclosure is designed to address the problems of the prior art, and therefore aims to provide a battery management device and method for setting the optimal negative electrode capacity of a battery cell.

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

[0011] Technical solution

[0012] According to one aspect of this disclosure, a battery management device may include: a charging unit configured to charge a battery cell; a measuring unit configured to measure the voltage and current of the battery cell; and a control unit configured to receive battery information including voltage and current from the measuring unit, estimate the state of charge (SOC) of the battery cell based on the received battery information, calculate the internal resistance of the battery cell based on the battery information whenever the SOC of the battery cell increases by a standard amount, compare the calculated internal resistance change pattern with a preset standard pattern, and set the negative electrode capacity of the battery cell based on the comparison result.

[0013] The control unit can be configured to generate a resistance curve representing the relationship between internal resistance and state of charge (SOC), determine the internal resistance variation pattern based on the generated resistance curve, and determine whether the determined variation pattern matches a standard pattern.

[0014] In the standard mode, the internal resistance can be preset to increase and then decrease in the reference SOC region.

[0015] The control unit can be configured to determine the variation pattern of the internal resistance in the reference SOC region in the generated resistance curve.

[0016] The control unit can be configured to determine a target peak value in the resistance curve, select a target SOC corresponding to the determined target peak value, and set the negative electrode capacity based on the selected target SOC.

[0017] The control unit can be configured to determine the negative electrode capacity ratio corresponding to the target SOC, and set the negative electrode capacity of the battery cell based on the determined negative electrode capacity ratio and a preset standard ratio.

[0018] The control unit can be configured to set the negative electrode capacity of the battery cell based on the determined negative electrode capacity ratio when the determined negative electrode capacity ratio exceeds the preset standard ratio.

[0019] The control unit can be configured to set the negative electrode capacity of the battery cell based on the standard ratio when the determined negative electrode capacity ratio is equal to or less than the preset standard ratio.

[0020] The control unit can be configured to control the charging unit to stop charging the battery cell for a predetermined time period whenever the state of charge (SOC) of the battery cell increases by a standard amount, and to calculate the internal resistance of the battery cell based on battery information during the predetermined time period.

[0021] A battery pack according to another aspect of this disclosure may include a battery management device according to one aspect of this disclosure.

[0022] A battery manufacturing apparatus according to another aspect of this disclosure may include a battery management device according to one aspect of this disclosure.

[0023] A battery management method according to another aspect of this disclosure may include: a charging step, wherein the charging step charges a battery cell; a measurement step, wherein while the battery cell is being charged, the measurement step measures battery information including the voltage and current of the battery cell; a SOC estimation step, wherein the SOC estimation step estimates the SOC of the battery cell based on the battery information measured in the measurement step; an internal resistance calculation step, wherein the internal resistance calculation step calculates the internal resistance of the battery cell based on the battery information whenever the SOC of the battery cell increases by a standard amount; and a negative electrode capacity setting step, wherein the negative electrode capacity setting step compares the calculated internal resistance change pattern with a preset standard pattern, and sets a negative electrode capacity corresponding to the battery cell based on the comparison result.

[0024] Beneficial effects

[0025] According to one aspect of this disclosure, an advantage is that the negative electrode capacity corresponding to the battery cell can be set based on the state of charge (SOC) of the battery cell as its internal resistance decreases. In other words, the negative electrode capacity of the battery cell is not uniformly set based on the theoretical N / P ratio, but can be set through actual verification.

[0026] The effects of this disclosure are not limited to those described above, and other unmentioned effects can be clearly understood by those skilled in the art from the description of the claims. Attached Figure Description

[0027] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings.

[0028] Figure 1 This is a schematic diagram illustrating a battery management device according to one embodiment of the present disclosure.

[0029] Figure 2 This is a schematic diagram illustrating a resistance curve according to one embodiment of the present disclosure.

[0030] Figure 3This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0031] Figure 4 This is a schematic diagram illustrating a battery management method according to yet another embodiment of the present disclosure.

[0032] (See attached image labels)

[0033] 1: Battery pack

[0034] 100: Battery Management Device

[0035] 110: Charging unit

[0036] 120: Measurement Unit

[0037] 130: Control Unit

[0038] 140: Storage unit Detailed Implementation

[0039] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general or dictionary meanings, but rather interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of the principle that the inventors are allowed to define the terms appropriately for the best interpretation.

[0040] Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of this disclosure. It should be understood that other equivalent substitutions and modifications may be made therein without departing from the scope of this disclosure.

[0041] Furthermore, in the description of this disclosure, detailed descriptions of relevant known elements or functions are omitted herein when such detailed descriptions are deemed to obscure the key subject matter of this disclosure.

[0042] Ordinal terms such as “first” and “second” can be used to distinguish one element from another among various elements, but are not intended to limit these elements by these terms.

[0043] Throughout this specification, when a section is referred to as "containing" or "including" any element, it means that the section may also include other elements without excluding them, unless otherwise specifically stated.

[0044] Furthermore, the term "control unit" described in the specification refers to a unit that processes at least one function or operation, and it may be implemented by hardware, software, or a combination of hardware and software.

[0045] Furthermore, throughout the specification, when one part is referred to as "connected" to another part, it is not limited to the case where the two are "directly connected," but also includes the case where the two are "indirectly connected," with another element inserted between them.

[0046] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0047] Figure 1 This is a schematic diagram illustrating a battery management device 100 according to one embodiment of the present disclosure.

[0048] Reference Figure 1 The battery management device 100 according to embodiments of the present disclosure may include a charging unit 110, a measuring unit 120, and a control unit 130.

[0049] The charging unit 110 can be configured to charge the battery cell.

[0050] Here, a battery cell refers to a physically separable, independent unit that includes a negative terminal and a positive terminal. For example, a pouch-type lithium polymer cell can be considered a battery cell.

[0051] Preferably, the charging unit 110 can charge the battery cell using a constant current (CC). For example, the charging unit 110 can charge the battery cell with a constant current of 0.2C (C-rate).

[0052] The measurement unit 120 can be configured to measure the voltage and current of the battery cell.

[0053] The measuring unit 120 can be connected to the positive and negative terminals of the battery cell. The measuring unit 120 can measure the positive and negative voltages of the battery cell, and measure the voltage of the battery cell based on the difference between the measured positive and negative voltages.

[0054] Furthermore, the measurement unit 120 can be connected to a current measurement unit disposed on the charging and discharging path of the battery cell. The measurement unit 120 can measure the charging current of the battery cell through the current measurement unit. Here, the charging and discharging path can be a high-current path through which the charging current and / or discharging current of the battery cell flows. Additionally, the current measurement unit can be a galvanometer or a shunt resistor.

[0055] The control unit 130 can be configured to receive battery information, including voltage and current, from the measurement unit 120.

[0056] Specifically, the control unit 130 can be connected to the measurement unit 120 for communication. The measurement unit 120 can send battery information about the voltage and current of the measured battery cell to the control unit 130. The control unit 130 can receive battery information from the measurement unit 120 to obtain battery information.

[0057] The control unit 130 can be configured to estimate the SOC (state of charge) of the battery cell based on the received battery information.

[0058] For example, control unit 130 can estimate the state of charge (SOC) of the battery cell based on the battery cell voltage using a preset equivalent circuit model (ECM) and an extended Kalman filter (EKF). As another example, control unit 130 can estimate the SOC of the battery cell based on the battery cell current using an ampere counting method. It should be noted that since the process of estimating the SOC of the battery cell based on an extended Kalman filter or an ampere counting method is known, its detailed description will be omitted.

[0059] The control unit 130 can be configured to calculate the internal resistance of the battery cell based on battery information whenever the state of charge (SOC) of the battery cell increases by a standard amount.

[0060] Since the charging unit 110 charges the battery cell with a constant current, the control unit 130 can calculate the internal resistance of the battery cell based on the voltage change and the current whenever the state of charge (SOC) of the battery cell increases by a standard amount.

[0061] For example, the internal resistance can be calculated as the ratio of voltage change to current. In other words, the control unit 130 can calculate the internal resistance of the battery cell using the formula "voltage change ÷ current".

[0062] The control unit 130 can be configured to compare the calculated internal resistance variation pattern with a preset standard pattern.

[0063] Here, the change pattern of internal resistance can be an increase / decrease pattern of internal resistance relative to the SOC of the battery cell.

[0064] First, the control unit 130 can be configured to generate a resistance curve representing the correspondence between internal resistance and SOC.

[0065] Figure 2 This is a schematic diagram illustrating a resistance curve according to one embodiment of the present disclosure.

[0066] Reference Figure 2 The resistance curve can be a curve representing the relationship between the state of charge (SOC) and the internal resistance. Specifically, when the SOC is set to X and the internal resistance is set to Y, the resistance curve can be represented as an XY curve.

[0067] exist Figure 2 In this embodiment, the charging unit 110 can charge the battery cell from 0% to 113% SOC. Furthermore, the control unit 130 can generate a resistance curve representing the calculated relationship between the internal resistance of the battery cell and its SOC.

[0068] The control unit 130 can be configured to determine the variation pattern of internal resistance based on the generated resistance curve.

[0069] Specifically, the control unit 130 can be configured to determine the variation pattern of the internal resistance relative to the reference SOC region in the generated resistance curve.

[0070] Here, the reference SOC region can be a SOC region that exceeds the reference SOC (RSOC). That is, the control unit 130 can determine the variation pattern of the internal resistance in the region where the reference SOC (RSOC) exceeds the generated resistance curve.

[0071] For example, in Figure 2 In this implementation, the reference SOC (RSOC) can be preset to 100%, and the reference SOC region can be preset to the SOC 100% excess region. The control unit 130 can determine the change pattern of the internal resistance in the SOC 100% excess region.

[0072] Specifically, in Figure 2 In this implementation, after referencing the State of Charge (RSOC), the internal resistance can increase with the increase of the SOC. Furthermore, based on an SOC of 111%, the internal resistance can be reduced. Therefore, the control unit 130 can determine the change pattern of the battery cell's internal resistance as an "increase / decrease mode".

[0073] The control unit 130 can be configured to determine whether a determined change pattern matches a standard pattern.

[0074] Specifically, the standard mode can be preset to a mode in which the internal resistance increases and then decreases in the reference SOC region. In other words, the control unit 130 can determine whether the determined change mode is a mode in which the internal resistance increases and then decreases.

[0075] For example, in Figure 2 In this implementation, the control unit 130 can determine the change pattern of the internal resistance of the battery cell as an "increase / decrease pattern". In this case, the control unit 130 can determine that the change pattern of the internal resistance matches the standard pattern.

[0076] The control unit 130 can be configured to set the negative electrode capacity of the battery cell based on the comparison results.

[0077] Specifically, the control unit 130 can calculate the N / P ratio of the battery cell based on the SOC corresponding to the point where the internal resistance decreases in the resistance curve. Furthermore, the control unit 130 can set the negative electrode capacity of the battery cell based on the calculated N / P ratio.

[0078] Here, the N / P ratio can be the value obtained by dividing the negative electrode capacity calculated considering the area and capacity per gram (g) of the negative electrode by the positive electrode capacity obtained considering the area and capacity per gram of the positive electrode. In other words, the N / P ratio is the ratio of the negative electrode capacity of the battery cell, and can be the ratio of the negative electrode capacity to the positive electrode capacity of the battery cell. For example, the N / P ratio can be calculated using the formula "negative electrode capacity ÷ positive electrode capacity" or "negative electrode capacity ÷ positive electrode capacity × 100".

[0079] Because the N / P ratio has a significant impact on the safety and capacity of a battery cell, it is typically greater than 1 (or 100%). This means that battery cells can be manufactured such that the capacity of the negative electrode is greater than that of the positive electrode. For reference, if the N / P ratio is below 1 (or 100%), lithium plating (lithium metal deposition) may occur during the charge and discharge of the battery cell. When lithium plating occurs, it becomes a cause of rapid deterioration in battery cell safety during high-speed discharge.

[0080] For example, in Figure 2 In this implementation, the State of Charge (SOC) corresponding to the point where the internal resistance decreases can be 111%. Therefore, the control unit 130 can calculate the N / P ratio of the battery cell as 1.11 or 111%. Furthermore, the control unit 130 can set the negative electrode capacity of the battery cell based on the set N / P ratio and the positive electrode capacity of the battery cell.

[0081] Preferably, the positive electrode capacity can be preset for a battery cell in the beginning-of-life (BOL) state. Therefore, the control unit 130 can set the negative electrode capacity corresponding to the battery cell based on the preset positive electrode capacity and the calculated N / P ratio.

[0082] The battery management device 100 according to the embodiments of this disclosure has the advantage of setting the negative electrode capacity corresponding to the battery cell based on the state of charge (SOC) of the battery cell where the internal resistance decreases. That is, according to the battery management device 100, the negative electrode capacity of the battery cell is not set uniformly based on the theoretical N / P ratio, but can be set through actual verification.

[0083] For example, based on the negative electrode capacity set by the battery management device 100, the negative electrode capacity included in a cell of the same type as the battery cell can be determined. In other words, in a battery cell manufactured to correspond to the negative electrode capacity set by the battery management device 100, the possibility of lithium plating can be reduced.

[0084] Meanwhile, the control unit 130 disposed in the battery management device 100 may optionally include processors, application-specific integrated circuits (ASICs), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the art, to execute various control logics performed in this disclosure. Furthermore, when the control logic is implemented in software, the control unit 130 can be implemented as a set of program modules. In this case, the program modules can be stored in memory and executed by the control unit 130. The memory can be located internally or externally to the control unit 130 and can be connected to the control unit 130 in various known ways.

[0085] Furthermore, the battery management device 100 may also include a storage unit 140. The storage unit 140 may store data required for the operation and function of each component of the battery management device 100, data generated during the execution of operations or functions, etc. The type of storage unit 140 is not particularly limited; it can be any known information storage device capable of recording, erasing, updating, and retrieving data. For example, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit 140 may store program code that defines processes that can be executed by the control unit 130.

[0086] For example, storage unit 140 can pre-store information about the positive electrode capacity of the battery cell. Control unit 130 can access storage unit 140 to obtain information about the positive electrode capacity of the battery cell.

[0087] In the following text, reference will be made to Figure 2 The process of setting the negative electrode capacity in the control unit 130 is described in more detail.

[0088] The control unit 130 can be configured to determine the target peak value TP in the resistance curve.

[0089] The control unit 130 can determine a target peak value TP in the reference SOC region. Here, the target peak value TP can be a point on the resistance curve with an upward convex shape. Specifically, the target peak value TP can be a point where the instantaneous rate of change of internal resistance with respect to SOC is 0. That is, based on the target peak value TP, the instantaneous rate of change can change from positive to negative.

[0090] For example, in Figure 2 In one implementation, the control unit 130 can determine the target peak value TP in the region where the reference SOC (RSOC) exceeds the range.

[0091] Furthermore, the control unit 130 can be configured to select a target SOC (TSOC) corresponding to a determined target peak value TP.

[0092] For example, in Figure 2In one implementation, the control unit 130 may select the target SOC (TSOC) corresponding to the target peak value TP as 111%.

[0093] Furthermore, the control unit 130 can be configured to set the negative electrode capacity based on the selected target SOC (TSOC).

[0094] As described above, the control unit 130 can be configured to determine the negative electrode capacity ratio corresponding to the target SOC (TSOC).

[0095] For example, in Figure 2 In one implementation, the control unit 130 can determine the negative electrode capacity ratio as 1.11% or 111% based on the target SOC (TSOC).

[0096] If the determined negative electrode capacity ratio exceeds the preset standard ratio, the control unit 130 can be configured to set the negative electrode capacity of the battery cell based on the determined negative electrode capacity ratio.

[0097] Conversely, when the determined negative electrode capacity ratio is equal to or less than the preset standard ratio, the control unit 130 can be configured to set the negative electrode capacity of the battery cell based on the standard ratio.

[0098] Typically, charging current promotes the electrochemical reaction at the interface of the negative electrode of a battery cell, allowing lithium ions to intercalate into the negative electrode. In this case, the internal resistance of the battery cell, calculated from the redox reaction based on the lithium concentrations at the positive and negative electrodes, gradually increases. However, when metallic lithium is deposited on the negative electrode, a portion of the charging current flows through the deposited metallic lithium, thus the calculated internal resistance of the battery cell gradually decreases. This is because only a portion of the charging current promotes the redox reaction.

[0099] Therefore, the control unit 130 can set the negative electrode capacity of the battery cell to a sufficiently large capacity based on the larger value between the determined negative electrode capacity ratio and the standard ratio, in order to reduce the possibility of lithium plating.

[0100] For example, in Figure 2 In this implementation, it is assumed that the determined negative electrode capacity ratio of 1.11 (or 111%) is greater than the standard ratio. The control unit 130 can set the negative electrode capacity of the battery cell based on the determined negative electrode capacity ratio and the preset positive electrode capacity. Specifically, the control unit 130 can calculate the negative electrode capacity according to the formula "N / P ratio × positive electrode capacity" or "N / P ratio × positive electrode capacity ÷ 100".

[0101] Thus, the preset standard ratio and the calculated N / P ratio can be considered different because, at the same time the battery cell is activated, a solid electrolyte interface (SEI) layer is formed on the negative electrode through the reaction at the interface between the negative electrode and the electrolyte, and the irreversible capacity of the negative electrode increases due to the formation of the SEI layer.

[0102] Therefore, the battery management device 100 according to the embodiments of this disclosure has the advantage of setting a larger negative electrode capacity by comparing the actual measured N / P ratio of the battery cell with a preset (pre-designed) standard ratio. Thus, battery cells manufactured based on the set negative electrode capacity can be more robust to lithium plating.

[0103] Meanwhile, the control unit 130 can be configured to stop charging the battery cell by controlling the charging unit 110 at a predetermined time whenever the SOC of the battery cell increases by a standard amount.

[0104] In addition, the control unit 130 can be configured to calculate the internal resistance of the battery cell based on battery information over a predetermined period of time.

[0105] For example, the control unit 130 can stop charging for 3 seconds whenever the state of charge (SOC) of the battery cell increases by 1%. Furthermore, the control unit 130 can calculate the battery's internal resistance based on the rate of voltage change of the battery cell during the 3-second charging pause. Additionally, the control unit 130 can generate a resistance curve by mapping the 1% increase in SOC to the internal resistance calculated based on the 3-second voltage change rate.

[0106] Typically, when current is applied to a battery cell, a transient voltage drop may occur due to electrical and electrolytic ion resistance (Ro, ohmic resistance). For example, a voltage drop based on ohmic resistance (Ro) can occur within approximately 0.1 seconds after current is applied.

[0107] Subsequently, based on the charge transfer reaction between the electrode and electrolyte surfaces, it can be determined through resistance (R... CT This generates a voltage drop. For example, a charge transfer reaction of approximately 3 seconds can be observed through a resistor (R). CT This causes a voltage drop.

[0108] Furthermore, the polarization resistance (R) caused by ion diffusion to the solid surface P This can cause a voltage drop. For example, while applying current, a voltage drop can be linearly generated based on the polarization resistance (R). P The voltage drop.

[0109] When lithium metal is deposited on the negative electrode, a portion of the charging current flows through the lithium metal. Therefore, according to the resistance (R) of the charge transfer reaction... CTThe resistance (R0) may decrease. This is because the insertion and extraction of lithium ions, based on the redox reactions at the positive and negative electrodes, occurs only with a portion of the charging current, while the remaining charging current flows through the metallic lithium. In other words, when lithium plating occurs on the negative electrode, the resistance (R0) decreases due to the ohmic resistance (Ro) and the resistance (R0) based on the charge transfer reaction. CT ) and polarization resistance (R P In ), based on the resistance (R) of the charge transfer reaction CT This may be affected.

[0110] Therefore, in order to calculate the resistance (R) of a battery cell based on the charge transfer reaction... CT Whenever the SOC of the battery cell increases by a standard amount, the control unit 130 can stop charging and calculate the internal resistance of the battery cell based on the rate of change of the battery cell's voltage over a predetermined time period (specifically, based on the resistance of the charge transfer reaction (R)). CT )).

[0111] For example, whenever the SOC of the battery cell increases by 1%, the control unit 130 can stop charging and calculate the internal resistance of the battery cell based on the rate of voltage change of the battery cell within 3 seconds. Afterward, the control unit 130 can control the charging unit 110 to resume charging of the battery cell.

[0112] Furthermore, the battery management device 100 according to this disclosure can be disposed in the battery pack 1. That is, the battery pack 1 according to this disclosure may include the aforementioned battery management device 100 and one or more battery cells B. In addition, the battery pack 1 may also include electrical equipment (relays, fuses, etc.) and a housing.

[0113] Figure 3 This is a diagram schematically illustrating an exemplary configuration of a battery pack 1 according to another embodiment of the present disclosure.

[0114] exist Figure 3 In this embodiment, the measurement unit 120 can be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. The measurement unit 120 can measure the positive electrode voltage of the battery cell B through the first sensing line SL1 and the negative electrode voltage of the battery cell B through the second sensing line SL2. Furthermore, the measurement unit 120 can measure the voltage of the battery cell B by calculating the difference between the measured positive electrode voltage and the measured negative electrode voltage.

[0115] Furthermore, the measurement unit 120 can be connected to the current measurement unit A via the third sensing line SL3. The current measurement unit A can be located on the charging and discharging path of the battery unit B. For example, the current measurement unit A can be a galvanometer or a shunt resistor.

[0116] Furthermore, the charging and discharging path can be a high-current path through which the charging current and discharging current of battery cell B flow. Therefore, the measurement unit 120 can measure the current of battery cell B by connecting the third sensing line SL3 to the current measurement unit A, and measure the capacity of battery cell B based on the measured current.

[0117] Furthermore, both ends of the charging unit 110 can be connected to the charging and discharging path of the battery cell B. For example, one end of the charging unit 110 can be connected to the positive terminal of the battery cell B in the charging and discharging path. The other end of the charging unit 110 can be connected to the negative terminal of the battery cell B in the charging and discharging path. Additionally, the charging unit 110 can charge the battery cell B under the control of the control unit 130.

[0118] For example, in Figure 3 In this embodiment, during the charging of battery cell B with a constant current, the charging unit 110 may stop charging for a predetermined time whenever the state of charge (SOC) of battery cell B increases by a standard amount. After the predetermined time has elapsed, the charging unit 110 may then recharge battery cell B with a constant current.

[0119] Furthermore, the battery management device 100 according to this disclosure can be installed in a battery manufacturing equipment.

[0120] For example, the battery manufacturing equipment can set the negative electrode capacity of a standard battery cell and mass-produce the same type of battery cells based on the set negative electrode capacity. In other words, the negative electrode capacity of the standard battery cell can be set by the battery management device 100, and the battery cells can be manufactured according to the set negative electrode capacity.

[0121] Therefore, since the battery cells manufactured by the battery manufacturing equipment include a negative electrode capacity that is sufficiently large compared to the positive electrode capacity, the possibility of lithium plating can be significantly reduced. Furthermore, since the negative electrode capacity of the battery cells manufactured by the battery manufacturing equipment is set to correspond to the N / P ratio at which lithium plating begins to occur in overcharged standard battery cells, an optimal capacity that is not excessive can be set.

[0122] As a result, since the battery cells manufactured by the battery manufacturing equipment have optimal negative electrode capacity, the battery cells can be manufactured with optimal volume, in which the possibility of lithium plating is significantly reduced. Therefore, the volume of the battery module, battery pack 1, and / or battery rack, including the battery cells manufactured by the battery manufacturing equipment, can also be reasonably reduced.

[0123] Figure 4 This is a schematic diagram illustrating a battery management method according to yet another embodiment of the present disclosure.

[0124] Specifically, each step of the battery management method can be performed by the battery management device 100. In the following text, for ease of description, content that overlaps with the previously described content will be omitted or briefly described.

[0125] Reference Figure 4 The battery management method may include a charging step (S100), a measurement step (S200), a SOC estimation step (S300), an internal resistance calculation step (S400), and a negative electrode capacity setting step (S500).

[0126] The charging step (S100) is a step of charging the battery cell B, and can be performed by the charging unit 110.

[0127] For example, in Figure 3 In one embodiment, the charging unit 110 can charge the battery unit B with a constant current.

[0128] The measurement step (S200) is a step of measuring battery information, including the voltage and current of battery cell B, while charging battery cell B, and can be performed by the measurement unit 120.

[0129] For example, in Figure 3 In this embodiment, the measurement unit 120 can measure the voltage of the battery cell B through the first sensing line SL1 and the second sensing line SL2, and measure the current of the battery cell B through the third sensing line SL3.

[0130] The SOC estimation step (S300) is a step of estimating the SOC of battery cell B based on the battery information measured in the measurement step (S200), and can be executed by the control unit 130.

[0131] For example, control unit 130 can estimate the SOC of battery cell B based on battery information by using an extended Kalman filter or ampere counting.

[0132] The internal resistance calculation step (S400) is a step that calculates the internal resistance of battery cell B based on battery information whenever the SOC of battery cell B increases by a standard amount, and can be executed by control unit 130.

[0133] For example, whenever the state of charge (SOC) of battery cell B increases by a standard amount, the control unit 130 can calculate the internal resistance of battery cell B based on the voltage change and current of battery cell B within a predetermined time period. Specifically, the control unit 130 can calculate the internal resistance of battery cell B using the formula "voltage change ÷ current".

[0134] The negative electrode capacity setting step (S500) is a step of comparing the calculated internal resistance change pattern with a preset standard pattern and setting the negative electrode capacity corresponding to the battery cell B based on the comparison result, and can be executed by the control unit 130.

[0135] For example, in Figure 2 In this implementation, the control unit 130 can generate a resistance curve representing the correspondence between the state of charge (SOC) and the internal resistance of the battery cell B. Furthermore, the control unit 130 can determine a target peak value (TP) in the resistance curve and determine the negative electrode capacity ratio (e.g., N / P ratio) of the battery cell B based on the target SOC (TSOC) corresponding to the determined target peak value (TP). Finally, the control unit 130 can set the optimal negative electrode capacity of the battery cell B based on a comparison between the determined negative electrode capacity ratio and a standard ratio.

[0136] The embodiments of this disclosure described above can be implemented not only by apparatus and methods, but also by a program that implements functions corresponding to the configuration of the embodiments of this disclosure, or a recording medium that records the program. Based on the description of the embodiments above, those skilled in the art can easily implement the program or the recording medium.

[0137] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific examples indicate preferred embodiments of this disclosure, they are given by way of illustration only, as various modifications and variations within the scope of this disclosure will become apparent to those skilled in the art based on the detailed description.

[0138] Furthermore, without departing from the technical aspects of this disclosure, those skilled in the art can make various substitutions, modifications and alterations to the disclosure described above, and this disclosure is not limited to the above embodiments and drawings, and each embodiment can be selectively combined in part or in whole to allow for various modifications.

Claims

1. A battery management device, the battery management device comprising: A charging unit configured to charge a battery cell; A measuring unit configured to measure the voltage and current of the battery cell; as well as A control unit is configured to receive battery information, including the voltage and the current, from the measurement unit; estimate the state of charge (SOC) of the battery cell based on the received battery information; calculate the internal resistance of the battery cell based on the battery information whenever the SOC of the battery cell increases by a standard amount; compare the calculated change pattern of the internal resistance with a preset standard pattern; and set the negative electrode capacity for the battery cell based on the comparison result. The control unit is configured to generate a resistance curve representing the correspondence between the internal resistance and the state of charge (SOC), determine the variation pattern of the internal resistance based on the generated resistance curve, and determine whether the determined variation pattern matches the standard pattern. Wherein, when the determined variation mode matches the standard mode, the control unit is configured to determine the target peak value in the resistance curve, select the target SOC corresponding to the determined target peak value, and set the negative electrode capacity based on the selected target SOC.

2. The battery management device according to claim 1, in, The standard mode is preset in the reference SOC region as a mode in which the internal resistance increases and then decreases.

3. The battery management device according to claim 2, in, The control unit is configured to determine the variation pattern of the internal resistance for the reference SOC region in the generated resistance curve.

4. The battery management device according to claim 1, in, The target peak value is the point in the resistance curve that has an upward convex shape.

5. The battery management device according to claim 4, in, The target peak value is the point where the instantaneous rate of change of the internal resistance with respect to the SOC is 0.

6. The battery management device according to claim 1, in, The battery cell is charged by the charging unit with a constant current.

7. The battery management device according to claim 1, in, The control unit is configured to determine the negative electrode capacity ratio corresponding to the target SOC, and to set the negative electrode capacity for the battery cell based on the determined negative electrode capacity ratio and a preset standard ratio.

8. The battery management device according to claim 7, in, The control unit is configured to set the negative electrode capacity for the battery cell based on the determined negative electrode capacity ratio when the determined negative electrode capacity ratio exceeds the preset standard ratio. The control unit is configured to set the negative electrode capacity of the battery cell based on the standard ratio when the determined negative electrode capacity ratio is equal to or less than the preset standard ratio.

9. The battery management device according to claim 1, in, The control unit is configured to control the charging unit to stop charging the battery cell for a predetermined time period whenever the state of charge (SOC) of the battery cell increases by a standard amount, and to calculate the internal resistance of the battery cell based on the battery information during the predetermined time period.

10. A battery pack comprising a battery management device according to any one of claims 1 to 9.

11. A battery manufacturing apparatus, the battery manufacturing apparatus comprising a battery management device according to any one of claims 1 to 9.

12. A battery management method, the battery management method comprising the following steps: The charging step charges the battery cells. The measurement step measures battery information, including the voltage and current of the battery cell, while the battery cell is being charged. A State of Charge (SOC) estimation step, which estimates the SOC of the battery cell based on the battery information measured in the measurement step; The internal resistance calculation step calculates the internal resistance of the battery cell based on the battery information whenever the SOC of the battery cell increases by a standard amount. as well as The negative electrode capacity setting step compares the calculated internal resistance variation pattern with a preset standard pattern, and sets the negative electrode capacity corresponding to the battery cell based on the comparison result. The calculated variation pattern of the internal resistance is determined by the following method: generating a resistance curve representing the correspondence between the internal resistance and the state of charge (SOC); determining the variation pattern of the internal resistance based on the generated resistance curve; and determining whether the determined variation pattern matches the standard pattern. When the determined change pattern matches the standard pattern, the preset standard pattern is determined by: determining the target peak value in the resistance curve, selecting the target SOC corresponding to the determined target peak value, and setting the negative electrode capacity based on the selected target SOC.

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