Battery management device and method, and battery pack including the battery management device

Abstract

A battery management device according to one embodiment of the present invention includes: a measuring unit for measuring the voltage of the battery after the discharge of the battery is terminated at a preset discharge termination voltage in each cycle; and a control unit configured to receive voltage information about the battery from the measuring unit in each cycle, calculate a first voltage deviation of the battery based on a preset first reference voltage and the voltage of the battery, calculate a second voltage deviation between the first voltage deviation and a preset second reference voltage in each cycle, and adjust the discharge termination voltage based on a reference deviation set to correspond to the current cycle and the second voltage deviation calculated in the current cycle.

Description

Technical Field

[0001] This application claims priority from Korean Patent Application No. 10-2021-0004158 filed in Korea on January 12, 2021, the disclosure of which is 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 improving the performance efficiency of a battery. Background Art

[0003] Recently, the demand for portable electronic products such as notebook computers, cameras, and portable phones has increased dramatically, and electric vehicles, energy storage batteries, robots, satellites, etc. have been developed in earnest. Therefore, high-performance batteries that allow repeated charging and discharging are being actively studied.

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

[0005] Furthermore, recent research is underway into negative electrode active materials that combine two or more materials to achieve various goals, such as high battery capacity and high output. However, because these two or more materials have different charge / discharge efficiencies and reaction voltage ranges, rapid degradation of the material with relatively low charge / discharge efficiency can lead to battery degradation. Therefore, for batteries that incorporate negative electrode active materials that combine two or more materials, it is necessary to develop methods for extending their lifespan. Summary of the Invention

[0006] Technical issues

[0007] The present disclosure aims to solve the problems of the prior art, and thus the present disclosure aims to provide a battery management device and method for improving the performance efficiency and life of a battery by adjusting the discharge termination voltage of the battery.

[0008] These and other objects and advantages of the present disclosure can be understood from the following detailed description and will become more apparent from the exemplary embodiments of the present disclosure. In addition, it will be readily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0009] Technical Solution

[0010] A battery management device according to one aspect of the present disclosure may include: a measuring unit configured to measure the voltage of the battery after the discharge of the battery is terminated at a preset discharge termination voltage in each cycle; and a control unit configured to receive voltage information of the battery from the measuring unit in each cycle, calculate a first voltage deviation of the battery based on a preset first standard voltage and the voltage of the battery, calculate a second voltage deviation between the first voltage deviation and a preset second standard voltage in each cycle, and adjust the discharge termination voltage based on a standard deviation set to correspond to a current cycle and the second voltage deviation calculated in the current cycle.

[0011] The control unit may be configured to determine a cycle interval to which a current cycle belongs among a plurality of preset cycle intervals, and adjust the discharge termination voltage based on a standard deviation set for the determined cycle interval and the calculated second voltage deviation.

[0012] The control unit may be configured to increase the discharge termination voltage when the calculated second voltage deviation is equal to or greater than the standard deviation.

[0013] A plurality of cycle intervals may be set based on a capacity retention rate per cycle of a reference cell corresponding to the battery.

[0014] The control unit may be configured to obtain a capacity curve indicating a corresponding relationship between cycles and capacities of a reference cell corresponding to the battery, and classify and set a plurality of cycles included in the capacity curve into a plurality of cycle intervals according to capacity change rates of the cycles.

[0015] The control unit may be configured to set a standard deviation for each of the plurality of loop intervals such that a standard deviation corresponding to a first loop interval among the plurality of loop intervals is lower than standard deviations corresponding to the remaining loop intervals.

[0016] After the discharge termination voltage is changed, the control unit may be configured to change the second standard voltage to a first voltage deviation corresponding to a cycle after the discharge termination voltage is changed.

[0017] The measuring unit may be configured to measure a rest voltage of the battery after a predetermined time has passed from the termination of discharge of the battery, and transmit the rest voltage as the voltage information of the battery.

[0018] The control unit may be configured to calculate the first voltage deviation by calculating a difference between the rest voltage and the first standard voltage.

[0019] A battery pack according to another aspect of the present disclosure may include the battery management apparatus according to aspects of the present disclosure.

[0020] According to another aspect of the present disclosure, a battery management method may include: a voltage measuring step, which measures the voltage of the battery after the discharge of the battery is terminated at a preset discharge termination voltage in each cycle; a first voltage deviation calculating step, which calculates the first voltage deviation of the battery based on a preset first standard voltage and the voltage of the battery; a second voltage deviation calculating step, which calculates the second voltage deviation between the first voltage deviation and a preset second standard voltage in each cycle; and a discharge termination voltage adjusting step, which adjusts the discharge termination voltage based on a standard deviation set to correspond to the current cycle and the second voltage deviation calculated in the current cycle.

[0021] Beneficial effects

[0022] According to one aspect of the present disclosure, a battery management apparatus has advantages of improving the performance efficiency of a battery and extending the life of the battery by adjusting a discharge termination voltage based on the voltage of the battery.

[0023] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not to be construed as being limited to the accompanying drawings.

[0025] Figure 1 is a diagram schematically illustrating a battery management apparatus according to an embodiment of the present disclosure.

[0026] Figure 2 is a diagram schematically illustrating a voltage distribution curve of a battery according to an embodiment of the present disclosure and a voltage distribution curve of a reference battery cell.

[0027] Figure 3 is a diagram schematically illustrating a capacity curve of a battery according to an embodiment of the present disclosure and a capacity curve of a reference battery cell.

[0028] Figure 4 is a diagram schematically illustrating a CE distribution curve of a battery according to an embodiment of the present disclosure and a CE distribution curve of a reference battery cell.

[0029] Figure 5 is a diagram schematically showing an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0030] Figure 6 is a diagram schematically illustrating a battery management method according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to appropriately define the terms for the best interpretation.

[0032] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes only and are not intended to limit the scope of the present disclosure, and it should be understood that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0033] Additionally, in describing the present disclosure, when a detailed description of related known elements or functions is deemed to obscure the key subject matter of the present disclosure, the detailed description is omitted herein.

[0034] Terms including ordinal numbers such as “first,” “second,” etc. may be used to distinguish one element from another among various elements, but are not intended to limit the elements by the terms.

[0035] Throughout the specification, when a part is referred to as “including” or “comprising” any elements, it means that the part may further include other elements, rather than excluding other elements, unless explicitly stated otherwise.

[0036] In addition, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” with another element interposed therebetween.

[0037] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0038] Figure 1 is a diagram schematically illustrating a battery management apparatus 100 according to an embodiment of the present disclosure.

[0039] refer to Figure 1 , the battery management device 100 according to an embodiment of the present disclosure may include a measuring unit 110 and a control unit 120 .

[0040] The measuring unit 110 may be configured to measure the voltage of the battery after discharge of the battery is terminated at a preset discharge termination voltage in each cycle.

[0041] Here, a battery means a physically separable individual cell comprising a negative terminal and a positive terminal. For example, a pouch-type lithium-ion battery can be considered a battery.

[0042] Here, a cycle may refer to the number of times a battery is fully discharged after being fully charged. For example, a process in which a battery is charged from 0% to 100% of SOC (State of Charge) and discharged from 100% to 0% of SOC may be represented as one cycle.

[0043] Specifically, the measuring unit 110 may be configured to measure the rest voltage of the battery after a predetermined time has passed since the discharge of the battery is terminated.

[0044] For example, the measurement unit 110 may measure the OCV (Open Circuit Voltage) of the battery after a predetermined time has passed from the termination of discharge of the battery.

[0045] Furthermore, the control unit 120 may be configured to receive voltage information of the battery from the measurement unit 110 in each cycle.

[0046] For example, the control unit 120 may be connected to communicate with the measurement unit 110. Therefore, the control unit 120 may receive voltage information of the battery from the measurement unit 110 in each cycle.

[0047] Specifically, the measurement unit 110 may be configured to transmit the voltage information of the battery to the control unit 120 in each cycle, so that the rest voltage is transmitted as the voltage information of the battery.

[0048] The control unit 120 may be configured to calculate a first voltage deviation of the battery based on a preset first standard voltage and the voltage of the battery.

[0049] Specifically, the control unit 120 may calculate the first voltage deviation by calculating the following formula 1.

[0050] [Formula 1]

[0051] VD1=V-VR1

[0052] Here, VD1 may be a first voltage deviation, V may be a voltage of the battery measured by the measuring unit 110 , and VR1 may be a first standard voltage.

[0053] Specifically, the first standard voltage is set for a battery in the BOL (Beginning of Life) state and can be set to the open circuit voltage of the battery in the BOL state. Preferably, after discharging of the battery in the BOL state is terminated, the first standard voltage can be set to the open circuit voltage. In other words, the first voltage deviation VD1 can be calculated based on the difference between the preset first standard voltage (open circuit voltage) of the battery and the measured voltage (open circuit voltage).

[0054] Figure 2Schematically illustrates a voltage distribution curve Pv of a battery according to an embodiment of the present disclosure and a voltage distribution curve Rv of a reference cell. Specifically, the voltage distribution curve Pv of the battery may be a distribution curve representing a corresponding relationship between cycles and the voltage of the battery.

[0055] For example, in Figure 2 In an embodiment, in the 0th cycle, the first voltage deviation VD1 may be preset to 0 mV. In the 19th cycle, as a result of calculating "battery voltage (V) - first standard voltage VR1" according to Formula 1, the first voltage deviation VD1 may be calculated to be -7 mV. That is, in the 19th cycle, the battery voltage (V) may be lower than the first standard voltage VR1.

[0056] The control unit 120 may be configured to calculate a second voltage deviation between the first voltage deviation and a preset second standard voltage in each cycle.

[0057] Specifically, the control unit 120 may calculate the second voltage deviation by calculating the following formula 2.

[0058] [Formula 2]

[0059] VD2=|VD1-VR2|

[0060] Here, VD2 may be the second voltage deviation, VD1 may be the first voltage deviation according to Formula 1, and VR2 may be the second standard voltage. Specifically, the second standard voltage VR2 may be the first voltage deviation VD1 in the 0th cycle or the cycle immediately after the discharge termination voltage is changed.

[0061] For example, in Figure 2 In an embodiment, the second standard voltage VR2 of the 0th to 19th cycles may be 0 mV. That is, the standard cycle in the 0th to 19th cycles may be the 0th cycle, and the second standard voltage VR2 may be 0 mV, which is the first voltage deviation VD1 of the 0th cycle. That is, in the 0th cycle, the first voltage deviation VD1 and the second standard voltage VR2 may be preset to 0 mV. In the 0th to 19th cycles, the control unit 120 may calculate the second voltage deviation VD2 by calculating the difference between the first voltage deviation VD1 and the second standard voltage VR2 of the battery according to Formula 2.

[0062] In addition, Figure 2In an embodiment, the second standard voltage VR2 of the 20th to 139th cycles may be 28 mV. That is, the standard cycle among the 20th to 139th cycles may be the 20th cycle, and the second standard voltage VR2 may be 28 mV, which is the first voltage deviation VD1 of the 20th cycle. In the 20th to 139th cycles, the control unit 120 may calculate the second voltage deviation VD2 by calculating the difference between the first voltage deviation VD1 and the second standard voltage VR2 of the battery according to Formula 2.

[0063] In addition, Figure 2 In an embodiment, the standard cycle after the 140th cycle may be the 140th cycle, and the second standard voltage VR2 may be 56 mV, which is the first voltage deviation VD1 of the 140th cycle. After the 140th cycle, the control unit 120 may calculate the second voltage deviation VD2 by calculating the difference between the first voltage deviation VD1 and the second standard voltage VR2 of the battery according to Formula 2.

[0064] The control unit 120 may be configured to adjust the discharge termination voltage based on the standard deviation set to correspond to the current cycle and the second voltage deviation calculated in the current cycle.

[0065] Specifically, the control unit 120 may be configured to determine the cycle interval to which the current cycle belongs among a plurality of preset cycle intervals.

[0066] For example, in Figure 2 In an embodiment, the plurality of loop intervals may include a first loop interval R1 and a second loop interval R2. The first loop interval R1 may include the 0th to 100th loops, and the second loop interval R2 may include the 101st to 400th loops.

[0067] Furthermore, the control unit 120 may be configured to adjust the discharge termination voltage based on the standard deviation set for the determined cycle interval and the calculated second voltage deviation.

[0068] For example, the control unit 120 may be configured to increase the discharge termination voltage when the calculated second voltage deviation is greater than or equal to the standard deviation. Conversely, if the calculated second voltage deviation is less than the standard deviation, the control unit 120 may maintain the discharge termination voltage unchanged.

[0069] exist Figure 2In an embodiment of the present invention, the standard deviation set for the first cycle interval R1 may be 7 mV, and the standard deviation set for the second cycle interval R2 may be 10 mV. In addition, the second voltage deviation calculated in the 19th cycle may be 7 mV. That is, in the 19th cycle, since the second voltage deviation (7 mV) between the second standard voltage (0 mV) and the first voltage deviation (-7 mV) is greater than or equal to the standard deviation (7 mV) set for the first cycle interval R1, the control unit 120 may increase the discharge termination voltage from the 20th cycle.

[0070] In addition, the second standard voltage may be changed from 0 mV to 28 mV from cycle 20. That is, after the discharge termination voltage is changed, the control unit 120 may be configured to change the second standard voltage to the first voltage deviation corresponding to the cycle after the discharge termination voltage is changed.

[0071] In addition, the second voltage deviation calculated in the 139th cycle may be 10 mV. That is, in the 139th cycle, since the second voltage deviation (10 mV) between the second standard voltage (28 mV) and the first voltage deviation (18 mV) is greater than or equal to the standard deviation (10 mV) set for the second cycle interval R2, the control unit 120 can further increase the discharge termination voltage from the 140th cycle.

[0072] In addition, the second standard voltage can be changed from 28mV to 56mV from the 140th cycle. Figure 2 In the embodiment, since the second voltage deviation is not calculated to be equal to or greater than the standard deviation after the 140th cycle, the control unit 120 may not further increase the discharge termination voltage.

[0073] Further references Figure 2 The voltage distribution curve Rv of the reference cell may be a voltage distribution curve of a reference cell whose discharge termination voltage is not adjusted by the control unit 120. Here, the reference cell corresponds to a battery and may be a battery prepared for a comparative example that can be compared with an embodiment of the present disclosure.

[0074] Since the discharge termination voltage is not adjusted for the reference cell, the first voltage deviation of the reference cell decreases until about the 210th cycle, and thereafter, the first voltage deviation may increase.

[0075] Will refer to Figure 3 and Figure 4 Describes a detailed comparison between the battery and a reference cell.

[0076] Figure 3is a diagram schematically illustrating a capacity curve Pcr of a battery according to an embodiment of the present disclosure and a capacity curve Rcr of a reference cell.

[0077] Specifically, Figure 3 The capacity curve may be a distribution curve showing the corresponding relationship between the cycle and the capacity retention rate. Here, the capacity retention rate may be the ratio of the discharge capacity in the current cycle to the discharge capacity of the battery in the initial cycle.

[0078] Generally, since battery cells deteriorate with increasing cycles, the capacity retention rate may decrease with increasing cycles.

[0079] refer to Figure 3 , from the 0th cycle to the 19th cycle, the capacity retention rates of the battery and the reference cell can be reduced equally. On the other hand, from the 20th cycle of adjusting the discharge end voltage of the battery, the rate of decrease in the capacity retention rate of the battery can be lower than the rate of decrease in the capacity retention rate of the reference cell. In addition, from the 140th cycle of further adjusting the discharge end voltage of the battery, the rate of decrease in the capacity retention rate of the battery can be lower than the rate of decrease in the capacity retention rate of the reference cell.

[0080] That is, the battery management device 100 according to an embodiment of the present disclosure can reduce the rate of decrease in the battery's capacity retention rate by appropriately adjusting the battery's discharge termination voltage. Therefore, as the battery and the reference cell deteriorate, the battery can retain more capacity than the reference cell, thereby increasing the battery's lifespan.

[0081] Figure 4 is a diagram schematically illustrating a CE distribution curve Pce of a battery according to an embodiment of the present disclosure and a CE distribution curve Rce of a reference cell.

[0082] Specifically, Figure 4 The CE distribution curve is a distribution curve that shows the corresponding relationship between cycles and Coulombic efficiency (CE). Here, Coulombic efficiency refers to the ratio of the capacity in the current cycle to the capacity in the previous cycle.

[0083] refer to Figure 4 , the coulombic efficiency of the battery can be maintained within a predetermined level from the 0th cycle to about the 160th cycle. Figure 2 , since the discharge termination voltage is adjusted in the 20th cycle and the 140th cycle, the Coulombic efficiency in the 20th cycle and the 140th cycle may be temporarily reduced, but the Coulombic efficiency may be maintained within a specific level in other cycles.

[0084] In addition, the coulombic efficiency of the battery is maintained within a predetermined level even after about the 160th cycle, and may increase after about the 300th cycle.

[0085] On the other hand, the Coulombic efficiency of the reference cell can decrease with increasing cycles and can increase after the 300th cycle.

[0086] In other words, the coulombic efficiency of the battery whose discharge end voltage is adjusted by the control unit remains within a specific range, but the coulombic efficiency of the reference cell whose discharge end voltage is not adjusted at all tends to decrease with increasing cycles (because the reference cell degrades).

[0087] Therefore, the battery management device 100 according to the embodiment of the present disclosure has the advantage of maintaining the coulombic efficiency of the battery at a specific level by adjusting the discharge end voltage based on the voltage of the battery. Therefore, the performance efficiency of the battery can be improved compared with the reference battery cell.

[0088] In addition, the control unit 120 provided in the battery management device 100 may selectively include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, etc. known in the art to execute the various control logics implemented in the present disclosure. In addition, when the control logic is implemented in software, the control unit 120 can be implemented as a set of program modules. In this case, the program modules can be stored in a memory and executed by the control unit 120. The memory can be located inside or outside the control unit 120 and can be connected to the control unit 120 in various well-known ways.

[0089] The battery management device 100 may also include a storage unit 130. The storage unit 130 can 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, and the like. The type of storage unit 130 is not particularly limited, as long as it is a known information storage device that can record, erase, update, and read data. Examples of information storage devices include RAM, flash memory, ROM, EEPROM, registers, and the like. Furthermore, the storage unit 130 can store program code that defines the processes executable by the control unit 120.

[0090] For example, the voltage distribution curve, the capacity curve, and the CE distribution curve of the reference battery cell may be pre-stored in the storage unit 130 .

[0091] A plurality of cycle intervals may be set based on a capacity retention rate per cycle of a reference cell corresponding to the battery.

[0092] Preferably, the battery and the reference cell may include a negative electrode active material manufactured by mixing two or more materials. Specifically, the battery and the reference cell may include a negative electrode active material in which two or more materials having different charge / discharge efficiencies and reaction voltage ranges are mixed.

[0093] For example, in Figures 2 to 4 In an embodiment, the battery and reference cell may include a negative electrode active material that is a mixture of SiO and graphite. In this case, SiO has a lower charge / discharge efficiency and reaction voltage range than graphite and may exhibit a greater capacity in the initial cycle.

[0094] Therefore, a plurality of cycle intervals may be classified in advance and set as a cycle interval in which a larger capacity is exhibited by SiO and a cycle interval in which a larger capacity is exhibited by graphite.

[0095] For example, in Figure 3 In an embodiment, the plurality of cycle intervals may be pre-classified and set to include a first cycle interval R1 from the 0th to the 100th cycles corresponding to SiO and a second cycle interval R2 after the 101st cycle corresponding to graphite.

[0096] Therefore, the battery management device 100 can adjust the discharge end voltage to correspond to the degradation of the battery by setting multiple cycle intervals considering the composite negative active material included in the battery and setting a standard deviation for each cycle interval. Therefore, the life of the battery including the composite negative active material can be increased.

[0097] Hereinafter, an embodiment in which a plurality of loop intervals are set by the control unit 120 will be described.

[0098] The control unit 120 may be configured to obtain a capacity curve indicating a corresponding relationship between cycles and capacities of a reference cell corresponding to the battery.

[0099] For example, in Figure 3 In an embodiment, the control unit 120 may obtain the capacity curve Rcr of the reference cell. The control unit 120 may obtain the capacity curve Rcr of the reference cell from an external server or an external device. In addition, the control unit 120 may access the storage unit 130 to obtain the capacity curve Rcr of the reference cell previously stored in the storage unit 130.

[0100] The control unit 120 may be configured to classify and set a plurality of cycles included in the capacity curve into a plurality of cycle intervals according to the capacity change rates of the cycles.

[0101] For example, the capacity change rate may be an instantaneous change rate of the cycle capacity retention rate. That is, the control unit 120 may calculate the instantaneous change rate of the cycle capacity retention rate as the capacity change rate based on the obtained capacity curve Rcr of the reference cell.

[0102] The control unit 120 may be configured to compare the calculated capacity change rate with a standard change rate, and set a plurality of cycle intervals according to the comparison result.

[0103] For example, the control unit 120 may compare the capacity change rate with a standard change rate while increasing the cycle count by 1 from cycle 0. Furthermore, the control unit 120 may determine cycles where the capacity change rate is equal to or less than the standard change rate, and may categorize the multiple cycle intervals based on the determined cycles. That is, the control unit 120 may be configured to categorize the multiple cycle intervals based on cycles where degradation of the reference cell is accelerated.

[0104] exist Figure 3 In the embodiment, the capacity change rate in the 100th cycle may be less than or equal to the standard change rate. Therefore, the control unit 120 may set the previous cycle as the first cycle interval R1 and the subsequent cycle as the second cycle interval R2 based on the 100th cycle.

[0105] Therefore, the battery management device 100 has the following advantages: by setting multiple cycle intervals based on the capacity curve Rcr of a reference battery cell including a composite negative electrode active material mixed with two or more materials, and setting a standard deviation corresponding to each of the multiple cycles, the discharge termination voltage of the battery can be appropriately adjusted.

[0106] The control unit 120 may be configured to set a standard deviation for each of the plurality of loop intervals such that a standard deviation corresponding to a first loop interval among the plurality of loop intervals is set lower than standard deviations corresponding to the remaining loop intervals.

[0107] For example, in Figures 2 to 4 In an embodiment, the standard deviation set in the first cycle interval R1 may be set to be smaller than the standard deviation set in the second cycle interval R2.

[0108] Specifically, in a battery including two or more types of composite negative electrode active materials, since the capacity is shown such that the use area of the active material with low charge / discharge efficiency and reaction voltage range is expanded in the initial cycle, the reduction amount of the capacity change rate in the initial cycle can be smaller.

[0109] However, when the capacity of an active material having low charge / discharge efficiency and a reaction voltage range is exhibited, degradation of the battery may be accelerated even though the total capacity of the battery seems to be maintained.

[0110] For example, reference Figure 3 With reference to the capacity curve Rcr of the reference cell, due to the capacity performance of SiO, the rate of change of the capacity retention rate in the first cycle interval R1 can be lower than the rate of change of the capacity retention rate in the second cycle interval R2. However, because the reference cell deteriorates due to the capacity performance of SiO, the control unit 120 can set the standard deviation of the first cycle interval R1 to be lower than the standard deviation of the second cycle interval R2. In addition, the control unit 120 can also suppress the capacity performance of SiO included in the battery by adjusting the discharge termination voltage of the battery based on the standard deviations set differently in the first cycle interval R1 and the second cycle interval R2. Therefore, since the capacity performance of SiO in the battery can be effectively reduced in the initial cycle, the life of the battery can be increased and the performance efficiency can be improved.

[0111] The battery management device 100 according to the present disclosure can be applied to a BMS (battery management system). That is, the BMS according to the present disclosure can include the above-described battery management device 100. In this configuration, at least some components of the battery management device 100 can be implemented by supplementing or adding functions included in the configuration of a conventional BMS. For example, the measurement unit 110, the control unit 120, and the storage unit 130 can be implemented as components of the BMS.

[0112] Figure 5 is a diagram schematically showing an exemplary configuration of a battery pack 1 according to another embodiment of the present disclosure.

[0113] The battery management device 100 according to the present disclosure may be provided in a battery pack 1. That is, the battery pack 1 according to the present disclosure may include the battery management device 100 and one or more battery cells B. In addition, the battery pack 1 may further include electrical devices (relays, fuses, etc.) and a housing.

[0114] refer to Figure 5 , load 2 can be connected to battery B through the positive terminal P+ and the negative terminal P- of the battery pack 1. Load 2 can be configured to charge and discharge battery B. Preferably, load 2 can discharge battery B to a discharge termination voltage. In addition, load 2 can discharge battery B to correspond to a discharge termination voltage changed by the control unit 120.

[0115] The measuring unit 110 may be connected to the battery B through a first sensing line SL1 and a second sensing line SL2. The measuring unit 110 may measure the positive electrode voltage of the battery B through the first sensing line SL1 and the negative electrode voltage of the battery B through the second sensing line SL2. In addition, the measuring unit 110 may measure the voltage of the battery B by calculating the difference between the measured positive electrode voltage and the measured negative electrode voltage.

[0116] If the reference battery cell RB is included in the battery pack 1 , the measurement unit 110 measures the voltage of the reference battery cell RB, but the control unit 120 may not adjust the discharge termination voltage of the reference battery cell RB.

[0117] Figure 6 is a diagram schematically illustrating a battery management method according to yet another embodiment of the present disclosure.

[0118] Preferably, each step of the battery management method may be performed by the battery management device 100. Hereinafter, it should be noted that contents repeated with those previously described will be omitted or briefly described.

[0119] refer to Figure 6 The battery management method may include a voltage measuring step (S100), a first voltage deviation calculating step (S200), a second voltage deviation calculating step (S300), and a discharge termination voltage adjusting step (S400).

[0120] The voltage measuring step ( S100 ) is a step of measuring the voltage of the battery B after the discharge of the battery B is terminated at a preset discharge termination voltage in each cycle, and may be performed by the measuring unit 110 .

[0121] The first voltage deviation calculating step ( S200 ) is a step of calculating a first voltage deviation of the battery B based on a preset first standard voltage and the voltage of the battery B, and may be performed by the control unit 120 .

[0122] For example, the control unit 120 may calculate a first voltage deviation of the battery B in each cycle based on the measured voltage of the battery B and a preset first standard voltage.

[0123] The second voltage deviation calculating step ( S300 ) is a step of calculating a second voltage deviation between the first voltage deviation and a preset second standard voltage in each cycle, and may be performed by the control unit 120 .

[0124] For example, in Figure 2In the 0th to 19th cycles of the embodiment, the control unit 120 may calculate the second voltage deviation VD2 by calculating the difference between the first voltage deviation VD1 and the second standard voltage VR2 of the battery according to Formula 2. The second standard voltage VR2 in the 0th to 19th cycles may be 0 mV, which is the first voltage deviation VD1 in the 0th cycle.

[0125] In addition, Figure 2 In the 20th to 139th cycles of the embodiment, the control unit 120 may calculate the second voltage deviation VD2 by calculating the difference between the first voltage deviation VD1 and the second standard voltage VR2 of the battery according to Formula 2. The second standard voltage VR2 in the 20th to 139th cycles may be 28 mV, which is the first voltage deviation VD1 in the 20th cycle.

[0126] in addition, Figure 2 The standard cycle after the 140th cycle of the embodiment may be the 140th cycle, and the second standard voltage VR2 may be 56 mV, which is the first voltage deviation VD1 of the 140th cycle.

[0127] The discharge end voltage adjustment step ( S400 ) is a step of adjusting the discharge end voltage based on a standard deviation set to correspond to the current cycle and a second voltage deviation calculated from the current cycle, and may be performed by the control unit 120 .

[0128] exist Figure 2 In an embodiment of the present invention, the standard deviation set for the first cycle interval R1 may be 7 mV, and the standard deviation set for the second cycle interval R2 may be 10 mV. In addition, the second voltage deviation calculated in the 19th cycle may be 7 mV. That is, in the 19th cycle, since the second voltage deviation (7 mV) between the second standard voltage (0 mV) and the first voltage deviation (-7 mV) is greater than or equal to the standard deviation (7 mV) set for the first cycle interval R1, the control unit 120 may increase the discharge termination voltage from the 20th cycle.

[0129] In addition, the second standard voltage may be changed from 0 mV to 28 mV from cycle 20. That is, after changing the discharge termination voltage, the control unit 120 may be configured to change the second standard voltage to the first voltage deviation corresponding to the cycle after changing the discharge termination voltage.

[0130] In addition, the second voltage deviation calculated in the 139th cycle may be 10 mV. That is, in the 139th cycle, since the second voltage deviation (10 mV) between the second standard voltage (28 mV) and the first voltage deviation (18 mV) is greater than or equal to the standard deviation (10 mV) set for the second cycle interval R2, the control unit 120 may further increase the discharge termination voltage from the 140th cycle.

[0131] In addition, the second standard voltage can be changed from 28mV to 56mV from the 140th cycle. Figure 2 In the embodiment, since the second voltage deviation is not calculated to be equal to or greater than the standard deviation after the 140th cycle, the control unit 120 may not further increase the discharge termination voltage.

[0132] The embodiments of the present disclosure described above can be implemented not only by devices and methods, but also by programs that implement functions corresponding to the configurations of the embodiments of the present disclosure or recording media that record the programs. Based on the above description of the embodiments, those skilled in the art can easily implement the programs or recording media.

[0133] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, as various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

[0134] In addition, without departing from the technical aspects of the present disclosure, those skilled in the art may make many substitutions, modifications and changes to the present disclosure, and the present disclosure is not limited to the above-mentioned embodiments and drawings, and each embodiment may be selectively combined in part or in whole to allow various modifications.

[0135] (reference numerals)

[0136] 1: Battery pack

[0137] 2: Load

[0138] 100: Battery management equipment

[0139] 110: Measurement unit

[0140] 120: Control unit

[0141] 130: Storage unit

Claims

1. A battery management device, comprising: a measuring unit configured to measure the voltage of the battery after discharge of the battery is terminated at a preset discharge termination voltage in each cycle; as well as a control unit configured to receive voltage information of the battery from the measuring unit in each cycle, calculate a first voltage deviation of the battery based on a preset first standard voltage and the voltage of the battery, calculate a second voltage deviation between the first voltage deviation and a preset second standard voltage in each cycle, and adjust a discharge termination voltage based on a standard deviation set to correspond to a current cycle and the second voltage deviation calculated in the current cycle, wherein the control unit is configured to increase the discharge termination voltage when the calculated second voltage deviation is equal to or greater than the standard deviation, wherein the battery comprises a negative electrode active material manufactured by mixing two or more materials, The first standard voltage is set to be the open circuit voltage of the battery at the beginning of its life. The second standard voltage is the first voltage deviation in the 0th cycle or in a cycle immediately after the discharge termination voltage is changed.

2. The battery management device according to claim 1, in, The control unit is configured to determine a cycle interval to which the current cycle belongs among a plurality of preset cycle intervals, and adjust the discharge termination voltage based on a standard deviation set for the determined cycle interval and the calculated second voltage deviation.

3. The battery management device according to claim 2, in, The control unit is configured to maintain the discharge termination voltage unchanged when the calculated second voltage deviation is smaller than the standard deviation.

4. The battery management device according to claim 2, in, A plurality of cycle intervals are set based on a capacity retention rate per cycle of a reference cell corresponding to the battery. The battery management device according to claim 1 , wherein: The battery includes a negative electrode active material mixed with SiO and graphite.

6. The battery management device according to claim 2, in, The control unit is configured to obtain a capacity curve indicating a corresponding relationship between cycles and capacities of a reference cell corresponding to the battery, and classify and set a plurality of cycles included in the capacity curve into a plurality of cycle intervals according to capacity change rates of the cycles.

7. The battery management device according to claim 6, in, The control unit is configured to set a standard deviation for each of the plurality of loop intervals so that a standard deviation corresponding to a first loop interval among the plurality of loop intervals is lower than standard deviations corresponding to the remaining loop intervals.

8. The battery management device according to claim 1, in, After the discharge end voltage is changed, the control unit is configured to change the second standard voltage to a first voltage deviation corresponding to a cycle after the discharge end voltage is changed.

9. The battery management device according to claim 1, in, The measuring unit is configured to measure a rest voltage of the battery after a predetermined time has passed since the discharge of the battery is terminated, and transmit the rest voltage as voltage information of the battery, and The control unit is configured to calculate the first voltage deviation by calculating a difference between the rest voltage and the first standard voltage. 10 . A battery pack comprising the battery management device according to claim 1 .

11. A battery management method, comprising: a voltage measuring step of measuring the voltage of the battery after discharge of the battery is terminated at a preset discharge termination voltage in each cycle; a first voltage deviation calculating step, wherein the first voltage deviation calculating step calculates a first voltage deviation of the battery based on a preset first standard voltage and the voltage of the battery; a second voltage deviation calculating step, wherein the second voltage deviation calculating step calculates a second voltage deviation between the first voltage deviation and a preset second standard voltage in each cycle; as well as a discharge end voltage adjusting step of adjusting the discharge end voltage based on a standard deviation set to correspond to a current cycle and the second voltage deviation calculated in the current cycle, When the calculated second voltage deviation is equal to or greater than the standard deviation, the discharge termination voltage is increased. wherein the battery comprises a negative electrode active material manufactured by mixing two or more materials, The first standard voltage is set to be the open circuit voltage of the battery at the beginning of its life. The second standard voltage is the first voltage deviation in the 0th cycle or in a cycle immediately after the discharge termination voltage is changed.

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