Apparatus and method for managing battery

Abstract

An apparatus for managing a battery according to one embodiment of the present invention comprises: a measurement unit configured to measure a voltage and a current of a battery comprising a plurality of negative electrode active materials; a discharge unit having one end connected to a positive electrode terminal of the battery and the other end connected to a negative electrode terminal of the battery and configured to discharge the battery; and a control unit configured to discharge the battery by controlling the discharge unit when the voltage of the battery corresponds to a preset reference voltage, and calculate the capacity of a target negative electrode active material among the plurality of negative electrode active materials of the battery on the basis of a current measured in a discharge process.

Description

Battery management device and method

[0001] This application claims priority to Korean Patent Application No. 10-2023-0193123, filed on December 27, 2023, the entire contents of which are disclosed in the specification and drawings of which are incorporated herein by reference.

[0002] The present invention relates to a battery management device and method, and more particularly, to a battery management device and method capable of predicting the lifespan of a battery.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based batteries.

[0005] While extensive research is being conducted on these batteries to improve capacity and density, improving lifespan and safety is also crucial. To improve battery safety, technology is required to accurately diagnose the current battery condition.

[0006] The present invention has been devised to solve the above problems, and its purpose is to provide a battery management device and method capable of diagnosing the current state of a battery and further diagnosing the expected lifespan of the battery.

[0007] Other objects and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0008] A battery management device according to one aspect of the present invention may include: a measuring unit configured to measure voltage and current of a battery including a plurality of negative electrode active materials; a discharging unit having one end connected to a positive terminal of the battery and the other end connected to a negative terminal of the battery and configured to discharge the battery; and a control unit configured to control the discharging unit to discharge the battery when the voltage of the battery corresponds to a preset reference voltage, and to calculate a capacity of a target negative electrode active material among the plurality of negative electrode active materials of the battery based on a current measured during the discharging process.

[0009] The above control unit may be configured to calculate the discharge capacity of the battery by accumulating the current measured during the discharge process, and to calculate the calculated discharge capacity as the capacity of the target negative electrode active material.

[0010] The control unit may be configured to control the discharge unit so that, when the voltage of the battery corresponds to the reference voltage, the discharge C-rate is set to be lower than a preset reference C-rate, and the battery is discharged according to the preset discharge C-rate.

[0011] The above reference voltage can be preset as a voltage at which the capacity of the target negative electrode active material begins to develop during the discharge process.

[0012] The above battery can be configured so that capacity development of the target negative electrode active material progresses at a voltage below the reference voltage, and capacity development of the non-target negative electrode active material progresses at a voltage above the reference voltage.

[0013] The above reference voltage may be preset as a voltage of a peak corresponding to the target negative electrode active material in a differential profile representing a correspondence between a voltage for the battery and a differential capacity for the voltage.

[0014] The control unit may be configured to determine a target profile corresponding to the capacity of the target negative electrode active material from among a plurality of capacity retention rate profiles preset to correspond to a plurality of capacities, and to predict the cycle-by-cycle life of the battery based on the determined target profile.

[0015] The above capacity retention rate profile can be configured to indicate a correspondence between cycles and capacity retention rate.

[0016] The control unit may be configured to predict the cycle-by-cycle life of the battery based on the capacity of the target negative electrode active material calculated when the cycle of the battery is less than or equal to a preset reference cycle.

[0017] A battery pack according to another aspect of the present invention may include a battery management device according to one aspect of the present invention.

[0018] A vehicle according to another aspect of the present invention may include a battery management device according to one aspect of the present invention.

[0019] A battery management method according to another aspect of the present invention may include a voltage measuring step of measuring a voltage of a battery including a plurality of negative electrode active materials; a discharging step of discharging the battery when the voltage of the battery corresponds to a preset reference voltage; a current measuring step of measuring a current of the battery discharged in the discharging step; and a capacity calculating step of calculating a capacity of a target negative electrode active material among the plurality of negative electrode active materials of the battery based on the current measured in the current measuring step.

[0020] According to one aspect of the present invention, a battery management device has an advantage in that it can quickly diagnose the capacity of a target negative electrode active material among a plurality of active materials included in a battery by measuring the discharge capacity of the battery for a voltage range below a reference voltage.

[0021] In addition, according to one aspect of the present invention, therefore, the battery management device has the advantage of being able to early select batteries with serious defects.

[0022] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0023] The following drawings attached to this specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0024] FIG. 1 is a schematic diagram illustrating a battery management device according to one embodiment of the present invention.

[0025] Figure 2 is a schematic diagram illustrating the lithiation reaction of the negative electrode of a battery during the charging process.

[0026] Figure 3 is a schematic diagram illustrating the lithiation reaction of the negative electrode of a battery during the discharge process.

[0027] FIG. 4 is a diagram schematically illustrating a battery profile according to one embodiment of the present invention.

[0028] FIG. 5 is a schematic diagram illustrating a differential profile according to one embodiment of the present invention.

[0029] FIG. 6 is a diagram schematically illustrating multiple capacity retention rate profiles according to one embodiment of the present invention.

[0030] FIG. 7 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0031] FIG. 8 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0032] FIG. 9 is a diagram schematically illustrating a battery management method according to another embodiment of the present invention.

[0033] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.

[0034] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0035] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0036] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0037] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0038] Additionally, throughout the specification, when we say that a part is "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0039]

[0040] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0041] FIG. 1 is a schematic diagram illustrating a battery management device (100) according to one embodiment of the present invention.

[0042] Referring to FIG. 1, a battery management device (100) may include a measuring unit (110), a discharging unit (120), and a control unit (130).

[0043] Here, a battery refers to a physically separate, independent cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. Furthermore, the battery may be of a cylindrical type, a prismatic type, or a pouch type. Furthermore, a battery may also refer to a battery bank, a battery module, or a battery pack in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be described herein below as referring to a single, independent cell.

[0044] Additionally, the battery may include multiple different types of negative electrode active materials. For example, the negative electrode of the battery may include a blend of two or more types of negative electrode active materials. For example, the target negative electrode active material may be silicon (Si) and / or silicon oxide (SiOx), and the non-target negative electrode active material may be graphite.

[0045] In addition, at a voltage below a preset reference voltage, the capacity of the target negative electrode active material may be developed, and at a voltage exceeding the reference voltage, the capacity of the non-target negative electrode active material may be developed. More specifically, when the battery is discharged, at a voltage exceeding the reference voltage, the capacity of the non-target negative electrode active material may be developed, and at a voltage below the reference voltage, the capacity of the target negative electrode active material may be developed.

[0046] FIG. 2 is a schematic diagram illustrating a lithiation reaction of a negative electrode of a battery during a charging process. FIG. 3 is a schematic diagram illustrating a lithiation reaction of a negative electrode of a battery during a discharging process. Specifically, the battery according to the embodiments of FIGS. 2 and 3 includes a negative electrode mixed with 20% silicon (SiO) and 80% graphite. In addition, the embodiments of FIGS. 2 and 3 are two-dimensional graphs in which the X-axis is set to the SOC (state of charge) of the battery and the Y-axis is set to the lithiation of silicon and graphite.

[0047] Referring to Fig. 2, during the charging process, lithiation of silicon and graphite proceeds competitively. However, referring to Fig. 3, during the discharging process, lithiation of graphite proceeds first, and lithiation of silicon proceeds later. That is, during the discharging process, since the charge / discharge hysteresis of graphite and silicon are different, the capacity development of graphite and silicon does not proceed competitively. For example, in the embodiment of Fig. 3, the capacity development of graphite begins at the beginning of the discharge, and the capacity development of silicon begins when the SOC of the battery reaches the reference SOC (SOCr). Here, it should be noted that the capacity development amount of silicon in the SOC section exceeding the reference SOC (SOCr) and the capacity development amount of graphite in the SOC section below the reference SOC (SOCr) are very small and can be ignored.

[0048] In the above, the target negative electrode active material is described as silicon and / or silicon oxide, and the non-target negative electrode active material is described as graphite. However, it should be noted that the present invention can be applied without limitation to a battery including a plurality of active materials having different voltage ranges in which capacity is expressed.

[0049] The measuring unit (110) can be configured to measure the voltage and current of a battery including a plurality of negative active materials.

[0050] Specifically, the measuring unit (110) can be electrically connected to the positive and negative terminals of the battery. In addition, the measuring unit (110) can measure the voltage of the battery by measuring the voltage across the two terminals of the battery.

[0051] Additionally, the measuring unit (110) may be connected to a current measuring unit included in the charge / discharge path of the battery. The measuring unit (110) may measure the charging current and discharging current of the battery using the current measuring unit. Here, the charge / discharge path is a high-current path through which the charge / discharge current of the battery flows.

[0052] For example, the measuring unit (110) can measure the voltage of the battery according to a preset voltage measurement cycle. In addition, the measuring unit (110) can measure the current of the battery according to a preset current measurement cycle. Since voltage and current are parameters that can be considered together when diagnosing the condition of the battery, it is required that the voltage and current be measured at the same or similar timing. Therefore, preferably, the voltage measurement cycle and the current measurement cycle can be set to be the same, and the voltage measurement time point and the current measurement time point can be set to be the same or within a predetermined time interval.

[0053] In addition, the measuring unit (110) can be connected to the control unit (130) so as to be able to communicate with it. For example, the measuring unit (110) can transmit information about the current and voltage of the measured battery to the control unit (130).

[0054] The discharge unit (120) can be configured so that one end is connected to the positive terminal of the battery and the other end is connected to the negative terminal of the battery.

[0055] Specifically, the discharge unit (120) may be electrically connected to the battery to form a closed circuit. For example, the discharge unit (120) may include a discharge resistor and a discharge switch connected in series with each other. In this case, the battery, the discharge resistor, and the discharge switch may be connected in series with each other to form a closed circuit.

[0056] The discharge unit (120) can be configured to discharge the battery.

[0057] Specifically, the operating state of the discharge unit (120) can be controlled by the control unit (130). More specifically, the operating state of the discharge switch included in the discharge unit (120) can be controlled by the control unit (130). For example, if the operating state of the discharge switch is controlled to a turn-on state by the control unit (130), the discharge unit (120) can discharge the battery. As another example, if the operating state of the discharge switch is controlled to a turn-off state by the control unit (130), the discharge unit (120) may not discharge the battery.

[0058] The control unit (130) may be configured to control the discharge unit (120) to discharge the battery when the voltage of the battery corresponds to a preset reference voltage (Vr).

[0059] Specifically, the control unit (130) can control the discharge unit (120) to discharge the battery when the voltage of the battery is equal to a preset reference voltage (Vr).

[0060] For example, for battery diagnosis, the battery may be charged or discharged until the voltage of the battery reaches a reference voltage (Vr). Once the voltage of the battery reaches the reference voltage (Vr) through charging or discharging, the control unit (130) may control the discharge unit (120) to discharge the battery.

[0061] FIG. 4 is a schematic diagram illustrating a battery profile (BP) according to one embodiment of the present invention. The battery profile (BP) can be expressed as a two-dimensional graph in which the X-axis is set to the SOC of the battery and the Y-axis is set to the voltage of the battery. In addition, the battery profile (BP) of FIG. 4 is a profile for a battery including a negative electrode mixed with 20% silicon and 80% graphite.

[0062] Specifically, the reference voltage (Vr) can be preset as a voltage at which the capacity development of the target negative electrode active material begins during the discharge process.

[0063] For example, in the embodiment of FIG. 4, the capacity development of graphite progresses in a voltage range exceeding the reference voltage (Vr), and the capacity development of silicon progresses in a voltage range below the reference voltage (Vr). That is, silicon is a target negative active material, and the reference voltage (Vr) can be preset as a voltage at which the capacity development of silicon begins during the discharge process of the battery. That is, when the voltage of the battery reaches the reference voltage (Vr), the control unit (130) can control the discharge unit (120) to discharge the battery. Therefore, the capacity development of silicon included in the battery can progress by the discharge unit (120).

[0064] The control unit (130) may be configured to calculate the capacity of the target negative electrode active material of the battery based on the current measured during the discharge process.

[0065] Specifically, the control unit (130) may be configured to calculate the discharge capacity of the battery by integrating the current measured during the discharge process. More specifically, the control unit (130) may calculate the discharge capacity of the battery by integrating the current measured after controlling the discharge unit (120).

[0066] For example, in the embodiment of FIG. 4, the control unit (130) can calculate the discharge capacity of the battery by accumulating the measured current until the voltage of the battery reaches a preset discharge termination voltage from the reference voltage (Vr).

[0067] And, the control unit (130) can be configured to calculate the calculated discharge capacity as the capacity of the target negative electrode active material.

[0068] Specifically, the reference voltage (Vr) may be preset as a voltage at which the capacity development of the target negative electrode active material begins. Accordingly, the discharge capacity based on the current measured in the voltage range below the reference voltage (Vr) may correspond to the capacity resulting from the capacity development of the target negative electrode active material. Accordingly, the control unit (130) may determine the calculated discharge capacity as the capacity of the target negative electrode active material.

[0069] For example, in the embodiment of FIG. 4, the discharge capacity corresponding to a voltage range below the reference voltage (Vr) can be calculated as the capacity of silicon.

[0070] A battery management device (100) according to one embodiment of the present invention has an advantage in that it can quickly diagnose the capacity of a target negative electrode active material among a plurality of active materials included in a battery by measuring the discharge capacity of the battery for a voltage range below a reference voltage (Vr).

[0071]

[0072] Meanwhile, the control unit (130) provided in the battery management device (100) may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, etc. known in the art to execute various control logics performed in the present invention. In addition, when the control logic is implemented in software, the control unit (130) may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the control unit (130). The memory may be located inside or outside the control unit (130) and may be connected to the control unit (130) by various well-known means.

[0073] In addition, the battery management device (100) may further include a storage unit (140). The storage unit (140) may store data or programs required for each component of the battery management device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (140) is not particularly limited in type as long as it is a known information storage means known to be capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (140) may store program codes defining processes executable by the control unit (130).

[0074]

[0075] The control unit (130) may be configured to set the discharge C-rate to a preset reference C-rate or lower when the voltage of the battery corresponds to the reference voltage (Vr).

[0076] Specifically, the higher the discharge C-rate, the more noise may be included in the measured voltage and current. That is, the lower the discharge C-rate, the higher the accuracy of the measured discharge capacity. Therefore, in order to more accurately calculate the capacity of the target negative electrode active material, the control unit (130) may set the discharge C-rate below a preset reference C-rate.

[0077] For example, the reference C-rate may be preset to 0.05 C. The control unit (130) may set the discharge C-rate to a C-rate of 0.05 C or less.

[0078] The control unit (130) may be configured to control the discharge unit (120) so that the battery is discharged according to the set discharge C-rate.

[0079] For example, assume that the discharge C-rate is set to 0.05 C. It takes approximately 20 hours to completely discharge a battery at a discharge C-rate of 0.05 C. However, during this time, the target negative active material's capacity does not develop, but rather only in voltage ranges below the reference voltage (Vr).

[0080] If the battery is discharged at a discharge C-rate below the reference C-rate starting from when the battery voltage exceeds the reference voltage (Vr), it may take an unnecessarily long time to calculate the capacity of the target negative electrode active material. In addition, since the calculated discharge capacity includes both the capacity of the non-target negative electrode active material and the capacity of the target negative electrode active material, there is a problem that an additional procedure is required to separate the calculated discharge capacity into the capacity of the target negative electrode active material and the capacity of the non-target negative electrode active material.

[0081] On the other hand, if the battery is discharged at a C-rate below the reference C-rate from the time the battery voltage corresponds to the reference voltage (Vr), the discharge time can be significantly reduced compared to completely discharging the battery. Furthermore, since the battery discharge capacity corresponds to the capacity of the target negative electrode active material, the aforementioned additional procedure is not required. Therefore, the capacity of the target negative electrode active material can be quickly calculated.

[0082] The battery management device (100) can accurately and quickly calculate the discharge capacity according to the capacity development of the target negative electrode active material by setting the discharge C-rate to a level lower than the reference C-rate when the voltage of the battery corresponds to the reference voltage (Vr).

[0083]

[0084] The reference voltage (Vr) can be preset as the voltage of the peak corresponding to the target negative active material in the differential profile (DP), which represents the relationship between the voltage for the battery and the differential capacity for the voltage.

[0085] Specifically, the differential profile (DP) may be a profile obtained by differentiating the battery profile (BP) with respect to voltage. In other words, the differential profile (DP) may be a profile representing a correspondence between voltage (V) and differential capacity (dQ / dV). Here, the differential capacity refers to the value obtained by differentiating capacity with respect to voltage.

[0086] A differential profile (DP) may contain one or more peaks. A peak corresponds to an inflection point in the battery profile (BP). Specifically, a peak is a point with an upward convex shape where the rate of change in differential capacity with respect to voltage is zero. That is, the instantaneous rate of change (the slope of differential capacity with respect to voltage) on the low-voltage side relative to the peak is positive, while the rate of change on the high-voltage side is negative.

[0087] Peaks are important factors that indicate the state of a battery. For example, peaks representing the battery's negative and positive states may each be included in the differential profile (DP). Furthermore, if a battery contains multiple active materials, peaks corresponding to each active material may be included in the differential profile (DP).

[0088] Based on the hysteresis difference of multiple active materials, the capacity development of the target negative electrode active material and the non-target negative electrode active material alternately progresses with respect to the reference voltage (Vr). Since the alternating progress of the capacity development of the target negative electrode active material and the non-target negative electrode active material significantly affects the state of the battery, the differential profile (DP) may include a peak corresponding to the reference voltage (Vr). In other words, among the multiple peaks included in the differential profile (DP), the voltage of the peak corresponding to the target negative electrode active material may be preset as the reference voltage (Vr).

[0089] FIG. 5 is a diagram schematically illustrating a differential profile (DP) according to one embodiment of the present invention. Specifically, the differential profile (DP) of FIG. 5 is a profile in which the X-axis is set to voltage and the Y-axis is set to differential capacity. The differential profile (DP) includes a first peak (p1), a second peak (p2), a third peak (p3), a fourth peak (p4), and a fifth peak (p5). Here, based on a 4.2 V battery, the first peak (p1) appearing at about 3.4 V or lower is known as a peak corresponding to silicon. That is, when the battery is discharged, the capacity expression of silicon proceeds from Vt, which is the voltage of the first peak (p1). Therefore, the voltage that serves as a reference for calculating the capacity of silicon can be preset to the voltage of the first peak (p1).

[0090]

[0091] The control unit (130) may be configured to determine a target profile corresponding to the capacity of the target negative electrode active material among a plurality of capacity retention rate profiles preset to correspond to a plurality of capacities.

[0092] Specifically, the capacity retention profile can be configured to represent a correspondence between cycles and capacity retention. Here, capacity retention is a value representing the ratio of the maximum capacity to the design capacity of the battery. For example, capacity retention decreases with increasing cycle degradation or calendar degradation.

[0093] FIG. 6 is a diagram schematically illustrating multiple capacity retention rate profiles according to one embodiment of the present invention.

[0094] Figure 6 includes a first capacity retention rate profile (RP1), a second capacity retention rate profile (RP2), and a third capacity retention rate profile (RP3). The first capacity retention rate profile (RP1) is a profile for a preset first battery, the second capacity retention rate profile (RP2) is a profile for a preset second battery, and the third capacity retention rate profile (RP3) is a profile for a preset third battery. Specifically, each of the first to third capacity retention rate profiles (RP3) is a profile that records the capacity retention rate per cycle while charging and discharging the corresponding battery at a 1C-rate for a voltage range of 2.5 V to 4.2 V.

[0095] Here, the first to third batteries all contain anodes composed of a mixture of 20% silicon and 80% graphite. Furthermore, based on the BOL (Beginning of Life) state, the first battery has the highest silicon capacity, while the third battery has the lowest. For example, the silicon capacity of the first battery is 1.53 Ah, the silicon capacity of the second battery is 1.51 Ah, and the silicon capacity of the third battery is 0.67 Ah.

[0096] The control unit (130) may be configured to predict the cycle-by-cycle life of the battery based on the determined target profile.

[0097] Preferably, the control unit (130) may be configured to predict the cycle-by-cycle life of the battery based on the capacity of the target negative electrode active material calculated when the cycle of the battery is less than or equal to a preset reference cycle.

[0098] The reference cycle may be the maximum cycle that can be determined as a BOL state. For example, the reference cycle may be preset to the 10th cycle.

[0099] That is, the control unit (130) can calculate the initial capacity of the target negative electrode active material of the battery and determine a target profile corresponding to the calculated initial capacity from a plurality of preset capacity retention rate profiles. In addition, the control unit (130) can predict the cycle-by-cycle life of the battery based on the determined target profile.

[0100] For example, if the target negative active material capacity of the battery is calculated as 0.67 Ah, the cycle-by-cycle life of the battery may follow the third capacity retention rate profile (RP3). In this case, the control unit (130) may predict the cycle-by-cycle life in advance based on the third capacity retention rate profile (RP3). For example, the control unit (130) may predict the battery life at approximately 110 cycles to be approximately 90%.

[0101] The battery management device (100) has the advantage of being able to predict the cycle-by-cycle life of a battery based on the capacity of the target negative active material calculated at the beginning of the battery cycle. That is, since the cycle-by-cycle life of a battery can be predicted based on the capacity of the initial target negative active material, batteries with a high risk of sudden death, etc., can be more easily selected. Therefore, the battery management device (100) has the advantage of being able to early select batteries with significant defects.

[0102]

[0103] The battery management device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the battery management device (100) described above. In this configuration, at least some of the components of the battery management device (100) can be implemented by supplementing or adding to the functions of the components included in a conventional BMS. For example, the measurement unit, discharge unit, control unit, and storage unit of the battery management device (100) can be implemented as components of the BMS.

[0104] Additionally, the battery management device (100) according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the battery management device (100) described above and one or more battery cells. Additionally, the battery pack may further include electrical components (relays, fuses, etc.) and a case.

[0105] FIG. 7 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0106] The positive terminal of the battery (10) can be connected to the positive terminal (P+) of the battery pack (1), and the negative terminal of the battery (10) can be connected to the negative terminal (P-) of the battery pack (1).

[0107] The measuring unit (110) may be connected to a first sensing line (SL1), a second sensing line (SL2), and a third sensing line (SL3). Specifically, the measuring unit (110) may be connected to a positive terminal of the battery (10) through the first sensing line (SL1), and may be connected to a negative terminal of the battery (10) through the second sensing line (SL2). The measuring unit (110) may measure the voltage of the battery (10) based on the voltage measured at each of the first sensing line (SL1) and the second sensing line (SL2).

[0108] And, the measuring unit (110) can be connected to the current measuring unit (A) through the third sensing line (SL3). For example, the current measuring unit (A) can be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery (10). The measuring unit (110) can measure the charging current of the battery (10) through the third sensing line (SL3) to calculate the charging amount. In addition, the measuring unit (110) can measure the discharging current of the battery (10) through the third sensing line (SL3) to calculate the discharging amount.

[0109] One end of the discharge unit 120 may be connected to the positive terminal of the battery 10, and the other end may be connected to the negative terminal of the battery 10. And, the discharge unit 120 may be operated under the control of the control unit 130. For example, the discharge unit 120 may discharge the battery 10 when it receives a discharge command (or discharge command signal) from the control unit 130.

[0110] For example, the discharge unit (120) may include a discharge resistor (121) and a discharge switch (122). In addition, the control unit (130) may control the discharge unit (120) to discharge the battery (10) by controlling the operating state of the discharge switch (122).

[0111] An external device can be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (1). For example, the external device can be a charging / discharging device or a load.

[0112]

[0113] FIG. 8 is a schematic drawing of a vehicle (800) according to another embodiment of the present invention.

[0114] Referring to FIG. 8, a battery pack according to an embodiment of the present invention may be included in a vehicle (800), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (810) may drive the vehicle (800) by supplying power to a motor through an inverter provided in the vehicle (800). Here, the battery pack (810) may include a battery management device (100). That is, the vehicle (800) may include a battery management device (100). In this case, the battery management device (100) may be an on-board diagnostic device included in the vehicle (800).

[0115]

[0116] FIG. 9 is a diagram schematically illustrating a battery management method according to another embodiment of the present invention.

[0117] Preferably, each step of the battery management method can be performed by a battery management device (100). In the following, for convenience of explanation, any content that overlaps with the previously described content will be omitted or briefly described.

[0118] Referring to FIG. 9, the battery management method may include a voltage measurement step (S100), a discharge step (S200), a current measurement step (S300), and a capacity calculation step (S400).

[0119] The voltage measurement step (S100) is a step of measuring the voltage of a battery including a plurality of negative active materials, and can be performed by a measurement unit (110).

[0120] The discharge step (S200) is a step of discharging the battery when the voltage of the battery corresponds to a preset reference voltage (Vr), and can be performed by the discharge unit (120).

[0121] Specifically, the reference voltage (Vr) may be preset as a voltage at which the capacity development of the target negative electrode active material begins during the discharge process. When the voltage of the battery reaches the reference voltage (Vr), the control unit (130) may control the discharge unit (120) to discharge the battery.

[0122] The current measurement step (S300) is a step of measuring the current of the battery being discharged in the discharge step (S200), and can be performed by the measurement unit (110).

[0123] For example, the measuring unit (110) can measure the discharge current of the battery when the discharge unit (120) discharges the battery under the control of the control unit (130).

[0124] The control unit (130) may perform a step of calculating the capacity of a target negative electrode active material among multiple negative electrode active materials of the battery based on the current measured in the current measurement step (S300).

[0125] Specifically, the control unit (130) can calculate the capacity of the target negative electrode active material of the battery by integrating the discharge current of the battery measured by the measurement unit (110). That is, in the voltage range below the reference voltage (Vr), the capacity of the target negative electrode active material is developed, and the capacity of the non-target negative electrode active material does not develop or is at a level that can be ignored. Therefore, the control unit (130) can determine the calculated capacity of the battery as the capacity of the target negative electrode active material.

[0126]

[0127] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

[0128] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0129] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

[0130] (Explanation of symbols)

[0131] 1: Battery pack

[0132] 10: Battery

[0133] 100: Battery management device

[0134] 110: Measurement section

[0135] 120: Discharge unit

[0136] 130: Control unit

[0137] 140: Storage

[0138] 800: car

[0139] 810: Battery Pack

Claims

1. A measuring unit configured to measure voltage and current of a battery including a plurality of negative active materials; A discharge unit having one end connected to the positive terminal of the battery and the other end connected to the negative terminal of the battery and configured to discharge the battery; and A battery management device characterized by including a control unit configured to control the discharge unit to discharge the battery when the voltage of the battery corresponds to a preset reference voltage, and to calculate the capacity of a target negative electrode active material among the plurality of negative electrode active materials of the battery based on the current measured during the discharge process.

2. In paragraph 1, The above control unit, A battery management device characterized in that it is configured to calculate the discharge capacity of the battery by accumulating the current measured during the above discharge process, and to calculate the calculated discharge capacity as the capacity of the target negative electrode active material.

3. In paragraph 1, The above control unit, A battery management device characterized in that, when the voltage of the battery corresponds to the reference voltage, the discharge C-rate is set to be lower than a preset reference C-rate, and the discharge unit is controlled so that the battery is discharged according to the preset discharge C-rate.

4. In paragraph 1, The above reference voltage is, A battery management device characterized in that the voltage is preset at which the capacity expression of the target negative electrode active material begins during the discharge process.

5. In paragraph 4, The above battery, A battery management device characterized in that it is configured such that capacity development of the target negative electrode active material progresses at a voltage below the reference voltage, and capacity development of a non-target negative electrode active material progresses at a voltage exceeding the reference voltage.

6. In paragraph 1, The above reference voltage is, A battery management device characterized in that the voltage of the peak corresponding to the target negative electrode active material is preset in a differential profile showing the relationship between the voltage and the differential capacity for the voltage for the battery.

7. In paragraph 1, The above control unit, It is configured to determine a target profile corresponding to the capacity of the target negative electrode active material among a plurality of capacity retention rate profiles preset to correspond to a plurality of capacities, and to predict the cycle-by-cycle life of the battery based on the determined target profile. The above capacity retention profile is, A battery management device characterized by being configured to exhibit a correspondence between cycles and capacity retention rates.

8. In paragraph 7, The above control unit, A battery management device characterized in that it is configured to predict the cycle-by-cycle life of the battery based on the capacity of the target negative active material calculated when the cycle of the battery is below a preset reference cycle.

9. A battery pack comprising a battery management device according to any one of claims 1 to 8.

10. A vehicle including a battery management device according to any one of claims 1 to 8.

11. A voltage measuring step for measuring the voltage of a battery containing a plurality of negative electrode active materials; A discharge step for discharging the battery when the voltage of the battery corresponds to a preset reference voltage; A current measuring step for measuring the current of the battery being discharged in the above discharge step; and A battery management method, characterized by including a capacity calculation step of calculating the capacity of a target negative electrode active material among the plurality of negative electrode active materials of the battery based on the current measured in the current measurement step.

Images