Battery management device, battery pack, and battery management method

Abstract

According to an embodiment of the present invention, a battery management device includes: a measuring unit configured to measure a first voltage of a battery cell at a first time point, and to measure a second voltage and a second capacity of the battery cell at a second time point after the first time point; and a control unit configured to calculate a voltage deviation between the first voltage and the second voltage, calculate a capacity deviation between a first capacity corresponding to the first voltage and the second capacity, determine a positive electrode side reaction factor and a negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation, and judge a side reaction type of the battery cell based on the positive electrode side reaction factor and the negative electrode side reaction factor.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0140726 filed in Korea on October 27, 2020, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a battery management device and a battery management method, and more particularly, to a battery management device and a battery management method capable of determining the type of side reactions generated in a battery cell and setting an operating state of the battery cell. Background Art

[0003] Recently, the demand for portable electronic products such as laptop computers, video cameras, and mobile phones has increased dramatically, and there has also been significant development of electric vehicles, energy storage batteries, robots, satellites, etc. Therefore, research is actively underway on high-performance batteries that allow repeated charge and discharge.

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

[0005] If a battery is exposed to high temperatures, side reactions may occur at the positive and negative electrodes, resulting in loss of available lithium and the generation and release of internal gases. Furthermore, prior art estimates of battery degradation rates utilize only battery capacity retention information (e.g., irreversible capacity information). However, this capacity retention information cannot specifically identify the types of side reactions occurring in the battery. Summary of the Invention

[0006] Technical issues

[0007] The present disclosure aims to solve the problems of the prior art, and therefore the present disclosure aims to provide a battery management device and method, which can determine the type of side reaction generated in the battery based on the voltage deviation and capacity deviation of the battery at different time points, and appropriately set the operating state of the battery.

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

[0009] Technical Solution

[0010] A battery management device according to one aspect of the present disclosure may include: a measuring unit configured to measure a first voltage of a battery cell at a first time point, and to measure a second voltage and a second capacity of the battery cell at a second time point later than the first time point; and a control unit configured to calculate a voltage deviation between the first voltage and the second voltage, calculate a capacity deviation between a first capacity corresponding to the first voltage and the second capacity, determine a positive electrode side reaction factor and a negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation, and judge a side reaction type of the battery cell based on the positive electrode side reaction factor and the negative electrode side reaction factor.

[0011] The control unit may be configured to calculate a voltage-based capacity corresponding to the voltage deviation based on a battery curve representing a corresponding relationship between a state of charge (SOC) and a voltage of the battery cell, and determine the positive electrode side reaction factor based on the voltage-based capacity or based on the voltage-based capacity and the capacity deviation according to the first voltage.

[0012] The control unit may be configured to estimate a first SOC corresponding to the first voltage, compare the estimated first SOC with a preset standard SOC, and determine the positive electrode side reaction factor of the battery cell corresponding to a comparison result.

[0013] When the first SOC is equal to or greater than the standard SOC, the control unit may be configured to determine the positive electrode side reaction factor based on the voltage-based capacity.

[0014] When the first SOC is less than the standard SOC, the control unit may be configured to determine the positive electrode side reaction factor based on a difference between the voltage-based capacity and the calculated capacity deviation.

[0015] The control unit may be configured to set an SOC at a starting point of a negative flat section in a difference curve representing a corresponding relationship between the SOC of the battery cell and a differential voltage with respect to the SOC as the standard SOC.

[0016] The control unit may be configured to determine a target peak value included in a predetermined SOC section in the difference curve, and set an SOC corresponding to the determined target peak value as the standard SOC.

[0017] The control unit may be configured to determine the negative electrode side reaction factor of the battery cell based on the capacity deviation.

[0018] The control unit can be configured to calculate a side reaction reference value based on the positive electrode side reaction factor and the negative electrode side reaction factor, compare the calculated side reaction reference value with a preset side reaction standard value, and determine whether the side reaction type of the battery cell is the positive electrode side reaction or the negative electrode side reaction based on the comparison result.

[0019] The control unit may be configured to set an operating condition for the battery cell based on the side reaction type determined for the battery cell.

[0020] When the type of the side reaction of the battery cell is determined to be the positive electrode side reaction, the control unit may be configured to reduce at least one of an upper limit SOC and an upper limit voltage of the battery cell.

[0021] When the type of the side reaction of the battery cell is determined to be the negative electrode side reaction, the control unit may be configured to reduce an upper limit temperature of the battery cell.

[0022] A battery management device according to another aspect of the present disclosure may further include: a discharging unit configured to discharge the battery cell at the second time point.

[0023] The measuring unit may be configured to measure the second capacity by measuring a discharge current of the battery cell when the battery cell is discharged at the second time point.

[0024] The battery cell may be configured to maintain a predetermined temperature or higher from the first time point to the second time point.

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

[0026] According to another aspect of the present disclosure, a battery management method may include: a first measurement step for measuring a first voltage of a battery cell at a first time point; a second measurement step for measuring a second voltage and a second capacity of the battery cell at a second time point later than the first time point; a voltage deviation and capacity deviation calculation step for calculating a voltage deviation between the first voltage and the second voltage, and calculating a capacity deviation between a first capacity corresponding to the first voltage and the second capacity; a side reaction factor determination step for determining a positive electrode side reaction factor and a negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation; and a side reaction type judgment step for judging the side reaction type of the battery cell based on the positive electrode side reaction factor and the negative electrode side reaction factor.

[0027] Beneficial effects

[0028] According to one aspect of the present disclosure, an advantage is that the type of side reaction generated in a battery cell can be determined based on the voltage deviation of the battery cell and the capacity deviation of the battery cell at two time points.

[0029] Furthermore, according to one aspect of the present disclosure, there is an advantage in that optimal operating conditions of a battery cell can be set to correspond to the side reaction type judged for the battery cell.

[0030] The effects of the present disclosure are not limited to the above-mentioned effects, and other unmentioned effects will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not to be construed as being limited to the drawings.

[0032] Figure 1 is a diagram schematically illustrating a battery management device according to one embodiment of the present disclosure.

[0033] Figure 2 is a diagram schematically illustrating a battery curve according to one embodiment of the present disclosure.

[0034] Figure 3 is a diagram schematically illustrating a capacity change of a battery cell at each time point according to one embodiment of the present disclosure.

[0035] Figure 4 is a diagram schematically illustrating a difference curve according to one embodiment of the present disclosure.

[0036] Figure 5 is a diagram schematically illustrating side reactions that may occur in a battery cell according to one embodiment of the present disclosure.

[0037] Figure 6 is a diagram schematically showing a battery pack according to another embodiment of the present disclosure.

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

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

[0040] Therefore, the description provided herein is only for the preferred embodiment for the purpose of illustration, and is not intended to limit the scope of the disclosure. It should be understood that other equivalents and modifications may be made to the disclosure without departing from the scope of the disclosure.

[0041] Furthermore, in the description of the present disclosure, when it is deemed that a detailed description of related known elements or functions may obscure the key subject matter of the present disclosure, such detailed description is omitted herein.

[0042] 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.

[0043] Throughout the specification, when a portion is referred to as “comprising” or “including” any element, it means that the portion may further include other elements, and does not exclude other elements, unless specifically stated otherwise.

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

[0045] Furthermore, 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.

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

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

[0048] refer to Figure 1 , a battery management device 100 according to one embodiment of the present disclosure may include a measuring unit 110 and a control unit 120 .

[0049] The measuring unit 110 may be configured to measure a first voltage of the battery cell at a first time point T1 , and to measure a second voltage and a second capacity of the battery cell at a second time point T2 later than the first time point T1 .

[0050] Here, a battery is a physically separable individual cell, including a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium-polymer battery can be considered a battery.

[0051] In addition, the second time point T2 is a time point different from the first time point T1 and may be a time point after a predetermined time has passed from the first time point T1. That is, after measuring the voltage (first voltage) of the battery cell at the first time point T1, the measurement unit 110 may measure the voltage (second voltage) and capacity (second capacity) of the battery cell at the second time point T2.

[0052] For example, the first time point T1 may be the time point at which the battery cell is started to be stored, and the second time point T2 may be the time point at which the battery cell is stopped to be stored. The measurement unit 110 may measure the voltage of the battery cell at the start time point and the end time point of the storage of the battery cell, and measure the remaining capacity of the battery cell at the end time point of the storage.

[0053] Preferably, the measuring unit 110 may measure the open circuit voltage (OCV) of the battery cell at the first time point T1 and the second time point T2.

[0054] Figure 2 Schematic diagram of a battery curve BP according to one embodiment of the present disclosure. Here, the battery curve BP may include a full-battery curve FP, a positive electrode curve PP, and a negative electrode curve NP of a battery cell. The full-battery curve FP is a curve representing the relationship between the voltage and the SOC of the battery cell. The positive electrode curve PP is a curve representing the relationship between the positive electrode voltage of the battery cell and the SOC of the battery cell. The negative electrode curve NP is a curve representing the relationship between the negative electrode voltage of the battery cell and the SOC of the battery cell.

[0055] For example, in Figure 2 In the embodiment, B1 may be a battery cell at a first time point T1, and B2 may be a battery cell at a second time point T2. The measuring unit 110 may measure a first voltage of the battery cell B1 as 4.1 [V] at the first time point T1, and a second voltage of the battery cell B2 as 4.0 [V] at the second time point T2.

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

[0057] Specifically, the control unit 120 may be connected to the measuring unit 110 for wired and / or wireless communication. In addition, the control unit 120 may receive the first voltage and the second voltage from the measuring unit 110 and calculate a voltage deviation between the received first voltage and the received second voltage.

[0058] For example, the control unit 120 can calculate the voltage deviation by calculating the formula of "first voltage - second voltage". Figure 2In the embodiment, the control unit 120 can calculate the formula of "4.1[V]-4.0[V]" and calculate that the voltage deviation is 0.1[V].

[0059] The control unit 120 may be configured to calculate a capacity deviation between the first capacity and the second capacity corresponding to the first voltage.

[0060] For example, the control unit 120 may calculate the capacity deviation by calculating a formula of “first capacity−second capacity”.

[0061] Specifically, the control unit 120 can estimate the first SOC corresponding to the first voltage by using the battery curve BP. Furthermore, the control unit 120 can calculate the first capacity corresponding to the first voltage by using the capacity of the battery cell in the BOL (Beginning of Life) state (e.g., the rated capacity of the battery cell) and the estimated first SOC. For example, when the capacity of the BOL battery cell is Q0 and the estimated first SOC is 90%, the control unit 120 can calculate "Q0×0.9" as the first capacity.

[0062] In addition, the second capacity of the battery cell may be the remaining capacity of the battery cell at the second time point T2. Figure 1 , the battery management device 100 according to one embodiment of the present disclosure may further include a discharge unit 130 .

[0063] The discharge unit 130 may be provided in the battery management device 100, and its operating state may be controlled by the control unit 120. Furthermore, if the discharge unit 130 receives a discharge command for a battery cell from the control unit 120, the discharge unit 130 may be configured to form a discharge path capable of discharging the battery cell. For example, the discharge unit 130 may include a resistor (not shown) and a switch element (not shown), and if the switch element is controlled to an on state by the control unit 120, the battery cell may be discharged. Thereafter, if the switch element is controlled to a off state by the control unit 120, the discharge of the battery cell may be terminated.

[0064] Here, any device whose operation state can be controlled by the control unit 120 can be applied to the switching element without limitation. For example, a contactor, a relay, a field effect transistor (FET), or a metal oxide semiconductor field effect transistor (MOSFET) can be applied to the switching element.

[0065] The measuring unit 110 may be configured to measure the second capacity of the battery cell by measuring the discharge current of the battery cell when the battery cell is discharged at the second time point T2. For example, the measuring unit 110 may measure the second capacity of the battery cell by accumulating the discharge current output from the battery cell when the battery cell is discharged.

[0066] Figure 3 FIG. 1 is a diagram schematically illustrating a capacity change at each time point of a battery cell according to an embodiment of the present disclosure.

[0067] exist Figure 3 In an embodiment, B0 may be a battery cell in a BOL state, and Q0 may be the maximum capacity of the battery cell B0 in the BOL state. B1 may be a battery cell at a first time point T1, and Q1 may be the capacity of the battery cell B1 at the first time point T1. B2 may be a battery cell at a second time point T2, and Q2 may be the capacity of the battery cell B2 at the second time point T2. For example, the first capacity preset for the battery cell may be Q0, and the second capacity of the battery cell may be Q2. Here, the units of Q0, Q1, and Q2 may be [mAh].

[0068] In addition, the control unit 120 may be configured to calculate the capacity deviation Qi based on the difference between the first capacity and the second capacity of the battery cell. Specifically, the control unit 120 may calculate the capacity deviation Qi of the battery cell by calculating the formula of "first capacity-second capacity".

[0069] For example, in Figure 3 In the embodiment, the control unit 120 may calculate the capacity deviation Qi of the battery cell by using the formula “Q1-Q2”.

[0070] The control unit 120 may be configured to determine a positive electrode side reaction factor and a negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation.

[0071] Here, the positive electrode side reaction factor may be a numerical value of a positive electrode side reaction generated in the battery cell, and the negative electrode side reaction factor may be a numerical value of a negative electrode side reaction generated in the battery cell. Furthermore, the positive electrode side reaction factor and the negative electrode side reaction factor are values ​​related to the capacity of the battery cell, and their units may be [mAh], which is the same as the unit of the battery cell capacity.

[0072] For ease of description, a specific implementation of how the control unit 120 determines the positive electrode side reaction factor and the negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation will be described below.

[0073] Finally, the control unit 120 may be configured to determine the side reaction type of the battery cell based on the positive electrode side reaction factor and the negative electrode side reaction factor.

[0074] Specifically, the control unit 120 may determine the type of side reaction that occurs more frequently in the battery cell, taking into account the positive electrode side reaction factor and the negative electrode side reaction factor.

[0075] For example, the control unit 120 may specifically distinguish and diagnose the type of side reaction that occurs more frequently in the battery cell by comparing the calculated positive electrode side reaction factor with the calculated negative electrode side reaction factor.

[0076] Specifically, the control unit 120 may be configured to calculate the side reaction reference value based on the positive electrode side reaction factor and the negative electrode side reaction factor.

[0077] For example, the control unit 120 may calculate the side reaction reference value by using the formula “positive electrode side reaction factor ÷ negative electrode side reaction factor”.

[0078] In addition, the control unit 120 may compare the calculated side reaction reference value with a preset side reaction standard value.

[0079] Here, the side reaction standard value is a preset value and may be a value indicating a standard for distinguishing the side reaction type of the battery cell as a positive electrode side reaction or a negative electrode side reaction according to the side reaction reference value. For example, the side reaction standard value may be preset to 0.5.

[0080] Finally, the control unit 120 may be configured to determine whether the side reaction type of the battery cell is a positive electrode side reaction or a negative electrode side reaction according to the comparison result of the side reaction reference value and the side reaction standard value.

[0081] For example, if the side reaction reference value is greater than or equal to the standard value, the control unit 120 may determine that the side reaction type of the battery cell is a positive electrode side reaction. As another example, if the side reaction reference value is less than the standard value, the control unit 120 may determine that the side reaction type of the battery cell is a negative electrode side reaction.

[0082] In the previous embodiment, it has been described that the control unit 120 determines the side reaction type of the battery cell by using the ratio of the positive electrode side reaction factor to the negative electrode side reaction factor, but it should be noted that the control unit 120 can also determine the side reaction type of the battery cell based on the comparison of the difference between the positive electrode side reaction factor and the negative electrode side reaction factor with another preset standard value.

[0083] The causes of positive and negative electrode side reactions in a battery cell may differ, and the operating conditions for preventing further side reactions may also differ. Therefore, the battery management device 100 according to one embodiment of the present disclosure has the advantage of specifically determining the type of side reaction occurring in a battery cell based on the voltage deviation of the battery cell and the capacity deviation Qi of the battery cell at two time points (first time point T1 and second time point T2).

[0084] Meanwhile, 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. Furthermore, when the control logic is implemented in software, the control unit 120 may be implemented as a set of program modules. In this case, the program modules may be stored in a memory and executed by the control unit 120. The memory may be located inside or outside the control unit 120 and may be connected to the control unit 120 via various well-known means.

[0085] In addition, reference Figure 1 The battery management device 100 may further include a storage unit 140. The storage unit 140 may store data required for the operation and function of each component of the battery management device 100, data generated during the operation or function, and the like. The type of storage unit 140 is not particularly limited, as long as it is a known information storage device that can record, erase, update, and read data. As an example, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit 140 may store program code that defines the processes that can be executed by the control unit 120.

[0086] For example, the storage unit 140 may pre-store Figure 2 In addition, the storage unit 140 can be configured according to Figure 3 The embodiment stores the BOL capacity Q0 of the battery cell B0 in the BOL state, the voltage and capacity Q1 of the battery cell B1 at the first time point T1, the voltage and capacity Q2 of the battery cell B2 at the second time point T2, and the like.

[0087] Hereinafter, an embodiment will be described in which the control unit 120 calculates the voltage-based capacity according to a voltage deviation between the voltage of the battery cell B1 at the first time point T1 and the voltage of the battery cell B2 at the second time point T2 .

[0088] The control unit 120 may be configured to calculate the voltage-based capacity corresponding to the voltage deviation based on the battery curve BP representing the corresponding relationship between the SOC and the voltage of the battery cell.

[0089] First, the control unit 120 may estimate a first SOC corresponding to the voltage of the battery cell B1 at a first time point T1 and a second SOC corresponding to the voltage of the battery cell B2 at a second time point T2 based on the battery curve BP. Figure 2In the embodiment, the control unit 120 may estimate the first SOC of the first voltage (4.1 [V]) of the battery cell B1 at the first time point T1 to be 90%. In addition, the control unit 120 may estimate the second SOC of the second voltage (4.0 [V]) of the battery cell B2 at the second time point T2 to be 80%.

[0090] Next, the control unit 120 may calculate an SOC deviation between a first SOC corresponding to the voltage of the battery cell B1 at the first time point T1 and a second SOC corresponding to the voltage of the battery cell B2 at the second time point T2. Figure 2 In the embodiment of FIG. 5 , the control unit 120 may calculate that the SOC deviation between the first SOC (90%) and the second SOC (80%) is 10%.

[0091] Finally, the control unit 120 may calculate the voltage-based capacity corresponding to the SOC deviation based on the BOL capacity Q0 of the BOL battery cell B0. Figure 2 In the embodiment, the control unit 120 may calculate the voltage-based capacity corresponding to the SOC deviation (10%) based on the BOL capacity Q0 of the BOL battery cell B0.

[0092] Alternatively, the control unit 120 may calculate the capacity of the first SOC of the battery cell B1 at the first time point T1 and the capacity of the second SOC of the battery cell B2 at the second time point T2, respectively. In addition, the control unit 120 may calculate the voltage-based capacity by calculating the difference between the capacity corresponding to the first SOC and the capacity corresponding to the second SOC.

[0093] Hereinafter, an embodiment in which the control unit 120 determines the positive electrode side reaction factor will be described first.

[0094] The control unit 120 may be configured to determine the positive electrode side reaction factor according to the voltage-based capacity or according to the voltage-based capacity and the capacity deviation Qi, depending on the first voltage.

[0095] Specifically, the control unit 120 may estimate a first SOC corresponding to the first voltage.

[0096] For example, the first voltage may be a voltage value of the battery cell B1 at the first time point T1 measured by the measurement unit 110. In addition, the control unit 120 may estimate a first SOC corresponding to the first voltage by using the battery curve BP.

[0097] The control unit 120 may compare the estimated first SOC with a preset standard SOC.

[0098] Here, the standard SOC may be preset as the SOC that is initially unaffected by the negative electrode of the battery cell. Figure 2 In the embodiment, it can be confirmed that the negative electrode voltage has almost no change in the approximate range of the SOC section above SOC 58%. That is, SOC 58% can be preset as the standard SOC. The detailed description of the control unit 120 setting the standard SOC will be described later.

[0099] The control unit 120 may be configured to determine a positive electrode side reaction factor of the battery cell corresponding to a comparison result between the first SOC and the standard SOC.

[0100] Specifically, if the first SOC is greater than or equal to the standard SOC, the control unit 120 may be configured to determine the positive electrode side reaction factor based on the voltage-based capacity corresponding to the voltage deviation.

[0101] For example, in Figure 2 In the embodiment, in an SOC range equal to or greater than the standard SOC (SOC 58%), even if the SOC changes, the negative electrode voltage hardly changes, so it can be considered that the positive electrode side reaction factor affects the battery cell. Therefore, if the first SOC of battery cell B1 at the first time point T1 is equal to or greater than the standard SOC, the control unit 120 can determine the positive electrode side reaction factor as a voltage-based capacity corresponding to the voltage deviation between the first voltage and the second voltage.

[0102] On the other hand, if the first SOC is less than the standard SOC, the control unit 120 may determine the positive electrode side reaction factor based on the difference between the voltage-based capacity corresponding to the voltage deviation and the negative electrode side reaction factor. Specifically, the control unit 120 may be configured to determine the positive electrode side reaction factor based on the difference between the voltage-based capacity corresponding to the voltage deviation and the calculated capacity deviation Qi.

[0103] For example, in Figure 2 In the embodiment, in the SOC section less than the standard SOC (SOC 58%), since both the negative electrode voltage and the positive electrode voltage change according to the change of SOC, it can be considered that the positive electrode side reaction factor and the negative electrode side reaction factor affect the battery cell.

[0104] Therefore, when the first SOC of battery cell B1 at the first time point T1 belongs to the SOC range less than the standard SOC, in order to determine the positive electrode side reaction factor, the control unit 120 may determine the positive electrode side reaction factor by subtracting the capacity deviation Qi affected by the negative electrode side reaction from the voltage-based capacity affected by the positive electrode side reaction. For example, the control unit 120 may calculate the positive electrode side reaction factor by calculating the formula "voltage-based capacity - capacity deviation Qi".

[0105] In other words, if the first SOC of the battery cell B1 at the first time point T1 is less than the standard SOC, both the positive electrode side reaction and the negative electrode side reaction may affect the battery cell. Therefore, the control unit 120 can determine the positive electrode side reaction factor as a value obtained by subtracting the capacity deviation Qi caused by the negative electrode side reaction from the voltage-based capacity calculated based on the voltage deviation at the first time point T1 and the second time point T2.

[0106] The battery management device 100 according to one embodiment of the present disclosure has the advantage that, by using the SOC of battery cell B1 at the first time point T1 during the determination of the positive electrode side reaction factor, the positive electrode side reaction factor can more accurately represent the positive electrode side reaction. Therefore, the battery management device 100 has the advantage of more accurately determining the side reaction type of the battery cell based on the comparison result of the positive electrode side reaction factor and the negative electrode side reaction factor.

[0107] Hereinafter, the content of setting the standard SOC by the control unit 120 in the above content will be described in more detail.

[0108] Specifically, the control unit 120 may be configured to obtain a battery curve BP representing the corresponding relationship between the SOC of the battery cell and the voltage of the battery cell. For example, the control unit 120 may obtain the battery curve BP stored in the storage unit 140. As another embodiment, the control unit 120 may store the battery curve BP in its internal memory or receive the battery curve BP from an external source.

[0109] The control unit 120 may be configured to set the SOC at a point where the negative flat section F of the battery cell starts as a standard SOC in the acquired battery curve BP.

[0110] Here, the negative electrode flat section F may refer to a section in which the negative electrode voltage of the battery cell remains the same or varies within a predetermined range even when the SOC of the battery cell increases in the negative electrode curve NP of the battery cell. In other words, the negative electrode flat section F refers to a section in which the negative electrode voltage does not change or barely changes even when the SOC of the battery cell increases. The negative electrode flat section F may occur at approximately SOC 50% or greater.

[0111] For example, in Figure 2 In the embodiment, referring to the negative electrode curve NP, the negative electrode flat section F may be SOC 58% to 100%. Therefore, the control unit 120 may set SOC 58% (ie, the point where the negative electrode flat section F starts) as the standard SOC.

[0112] Meanwhile, the control unit 120 may more accurately set the standard SOC based on the differential curve representing the corresponding relationship between the SOC and the differential voltage of the battery cell.

[0113] Here, the differential voltage can be the instantaneous rate of change of voltage relative to the SOC. That is, the differential voltage is the voltage difference relative to the SOC and can be expressed as dV / dSOC. Furthermore, the differential curve can be represented as an XY graph, where X is set to the SOC and Y is set to the differential voltage (dV / dSOC).

[0114] Figure 4 Schematically illustrates a differential curve DP according to an embodiment of the present disclosure. Specifically, Figure 4 Can be corresponding to Figure 2 The difference curve DP of the battery curve BP.

[0115] For example, reference Figure 2 and Figure 4 , the control unit 120 may generate a differential curve DP representing the corresponding relationship between the SOC and the differential voltage based on the battery curve BP. As another embodiment, the differential curve DP may be pre-stored in the storage unit 140, and the control unit 120 may access the storage unit 140 to obtain the differential curve DP. As another embodiment, the control unit 120 may obtain the differential curve DP by receiving the differential curve DP from an external source.

[0116] The control unit 120 may be configured to determine a target peak value TP included in a predetermined SOC section from the acquired difference curve DP.

[0117] Specifically, the differential curve DP may include multiple peaks. A peak is a point in the differential curve DP where the instantaneous rate of change of the differential voltage relative to the SOC is zero, and may be a point where the instantaneous rate of change of the peak changes from positive to negative. In other words, the peak may be a point in the differential curve DP that has an upward convex shape.

[0118] The control unit 120 may determine a peak value included in a predetermined SOC section among a plurality of peak values ​​included in the difference curve DP as the target peak value TP. Preferably, the predetermined SOC section may be preset as the SOC where the negative flat section F in the negative curve NP of the battery cell begins.

[0119] For example, reference Figure 2 and Figure 4 , the predetermined SOC section may be preset as a section from 50% SOC to 60% SOC. Figure 4 In the embodiment of FIG. 5 , the control unit 120 may determine a peak at 58% SOC among a plurality of peaks included in the difference curve DP as the target peak TP.

[0120] Furthermore, the control unit 120 may be configured to set the SOC corresponding to the determined target peak value TP as a standard SOC.

[0121] For example, in Figure 4 In the embodiment of FIG, the control unit 120 may set the SOC 58% corresponding to the target peak TP as the standard SOC. That is, the target peak TP may be a peak corresponding to the starting point of the negative flat section F in the negative curve NP of the battery cell.

[0122] More preferably, the control unit 120 may set the standard SOC in consideration of both the battery curve BP and the difference curve DP.

[0123] For example, the control unit 120 may determine the SOC at the starting point of the negative electrode flat section F in the negative electrode curve NP of the battery cell, and determine the SOC corresponding to the target peak TP in the difference curve DP. Furthermore, if the two determined SOCs are the same, the control unit 120 may set the determined SOC as the standard SOC. If the two SOCs determined by the control unit 120 are different, the control unit 120 may set the SOC determined based on the difference curve DP as the standard SOC.

[0124] Hereinafter, an embodiment in which the control unit 120 determines the negative electrode side reaction factor will be described.

[0125] The control unit 120 may be configured to determine a negative electrode side reaction factor of the battery cell based on the capacity deviation.

[0126] Specifically, the control unit 120 may estimate the first SOC based on the first voltage of the battery cell B1 at the first time point T1 using the battery curve BP. In addition, the control unit 120 may calculate a first capacity corresponding to the first SOC based on the BOL capacity Q0 of the BOL battery cell B0.

[0127] For example, in Figure 3 In the embodiment, the capacity of the battery cell B1 at the first time point T1 can be calculated as Q1 [mAh].

[0128] In addition, the control unit 120 can control the discharge unit 130 to discharge the battery cell B2 at the second time point T2. When the battery cell B2 is discharged by the discharge unit 130, the measurement unit 110 can measure the discharge current of the battery cell B2 to calculate the discharge capacity. Here, the discharge capacity is the remaining capacity of the battery cell B2 at the second time point T2.

[0129] For example, in Figure 3 In the embodiment, the measuring unit 110 may calculate that the capacity of the battery cell B2 at the second time point T2 is Q2 [mAh].

[0130] The control unit 120 can calculate the capacity deviation Qi by calculating the difference between the first capacity Q1 and the second capacity Q2. That is, the capacity deviation Qi can be the capacity change of the battery cell from the first time point T1 to the second time point T2. More specifically, the capacity deviation Qi can be the self-discharge amount of the battery cell from the first time point T1 to the second time point T2.

[0131] The control unit 120 may determine the calculated capacity deviation Qi as a negative electrode side reaction factor of the battery cell.

[0132] Figure 5 is a diagram schematically illustrating side reactions that may occur in a battery cell according to one embodiment of the present disclosure.

[0133] refer to Figure 5 In the negative electrode N of the battery cell, as lithium ions (Li+) and electrons (e-) are consumed, SEI (solid electrolyte interphase) S1 may be generated. Subsequently, if lithium ions (Li+) are further supplied from the electrolyte to the negative electrode N, more SEI S2 may be generated on the surface of the generated SEI S1. That is, when a side reaction occurs at the negative electrode N of the battery cell, the lithium ions (Li+) and electrons (e-) contained in the battery cell may be irreversibly reduced. Therefore, the control unit 120 can determine the negative electrode side reaction factor based on the calculated capacity deviation Qi.

[0134] In summary, the control unit 120 can calculate the capacity deviation Qi based on the difference between the capacity Q1 of the battery cell B1 at the first time point T1 and the capacity Q2 of the battery cell B2 at the second time point T2, and determine the calculated capacity deviation Qi as the negative electrode side reaction factor. Furthermore, if the first SOC of the battery cell B1 at the first time point T1 is equal to or greater than the standard SOC, the control unit 120 can determine the voltage-based capacity calculated based on the voltage deviation of the battery cell at the first time point T1 and the second time point T2 as the positive electrode side reaction factor. Conversely, if the first SOC is less than the standard SOC, the control unit 120 can determine the value obtained by subtracting the capacity deviation Qi from the voltage-based capacity as the positive electrode side reaction factor.

[0135] The battery management device 100 according to one embodiment of the present disclosure can determine the positive electrode side reaction factor by considering the voltage of the battery cell B1 at the first time point T1 when the battery cell begins to be stored, and determine the negative electrode side reaction factor by considering the capacity change (e.g., self-discharge) of the battery cell during storage. Therefore, the battery management device 100 has the advantage of specifically distinguishing and determining the positive electrode side reaction factor of the positive electrode side reaction and the negative electrode side reaction factor of the negative electrode side reaction of the battery cell.

[0136] The control unit 120 may be configured to set operating conditions for the battery cells based on the side reaction types determined for the battery cells.

[0137] Specifically, because the conditions under which positive and negative electrode side reactions favorably occur differ, the control unit 120 can set different operating conditions for each battery cell based on the type of side reaction. That is, to effectively prevent further degradation of the battery cell, the control unit 120 can appropriately set the operating conditions for the battery cell based on the type of side reaction.

[0138] For example, when the type of the side reaction of the battery cell is determined to be a positive electrode side reaction, the control unit 120 may be configured to reduce at least one of the upper limit SOC (maximum allowable SOC) and the upper limit voltage (maximum allowable voltage) of the battery cell.

[0139] On the contrary, when the type of the side reaction of the battery cell is determined to be a negative electrode side reaction, the control unit 120 may be configured to reduce the upper limit temperature (the maximum allowable temperature) of the battery cell.

[0140] Specifically, control unit 120 can set optimal operating conditions for the battery cell based on the determined side reaction type of the battery cell. These operating conditions can be stored in storage unit 140 and / or control unit 120 and taken into account during operation of the corresponding battery cell. This prevents the battery cell from experiencing unexpected side reactions and thus rapid degradation, as the corresponding battery cell operates according to the operating conditions set by control unit 120.

[0141] In addition, the operating conditions set by the control unit 120 may be stored in an external server. The external server may transmit the set operating conditions to a device or system provided with the corresponding battery cell, thereby inducing the corresponding battery cell to operate according to the set operating conditions.

[0142] Meanwhile, the battery cell may be configured to be maintained at a predetermined temperature or higher from the first time point T1 to the second time point T2. For example, the predetermined temperature may be 40°C or higher.

[0143] Generally speaking, when a battery cell is exposed to high temperature, side reactions may occur. Specifically, when a battery cell is exposed to high temperature, the electrolyte contained in the battery cell may be decomposed, and lithium ions (Li+) contained in the electrolyte may be supplied to the positive electrode and / or the negative electrode. In this case, the high potential (high SOC) capacity of the positive electrode supplied with lithium ions (Li+) from the electrolyte may not be used. In addition, the negative electrode supplied with lithium ions (Li+) from the electrolyte may further produce Figure 5SEI described in S2.

[0144] Therefore, when a condition (e.g., a predetermined temperature maintenance condition) is met during storage of a battery cell and a side reaction condition is satisfied, the battery management device 100 according to one embodiment of the present disclosure can specifically determine whether the positive electrode side reaction is predominant or the negative electrode side reaction is predominant in the battery cell. Furthermore, the battery management device 100 can appropriately set the operating conditions of the battery cell to satisfy the temperature maintenance condition.

[0145] The battery management device 100 according to the present disclosure can be applied to a BMS (battery management system). That is, the BMS according to the present disclosure can include the battery management device 100 described above. In this configuration, at least some components of the battery management device 100 can be implemented by supplementing or adding functions to the configuration included in a conventional BMS. For example, the measurement unit 110, the control unit 120, the discharge unit 130, and the storage unit 140 can be implemented as components of the BMS.

[0146] The battery management device 100 can be applied not only to a BMS but also to a battery storage system.

[0147] Here, the battery storage system may be a system capable of storing battery cells from a first time point T1 to a second time point T2.

[0148] For example, manufactured battery cells can be loaded into a storage space such as a container and then shipped away. The battery management device 100 can be applied to a battery storage system and diagnose that the state of the battery cells stored from a first time point T1 to a second time point T2 is an empty state. Specifically, the battery management device 100 can specifically determine the type of side reaction occurring in the battery cell when the battery cell is being stored in an empty state, and set operating conditions suitable for each battery cell. Therefore, since the corresponding battery cell operates according to the operating conditions set by the battery management device 100, it is possible to effectively prevent additional side reactions from occurring. Through this, since the degradation of the battery cell can be effectively prevented, the expected life of the battery cell can be greatly increased.

[0149] Figure 6 is a diagram schematically showing a battery pack 1 according to another embodiment of the present disclosure.

[0150] Furthermore, the battery management device 100 according to the present disclosure can be provided in a battery pack 1. Specifically, the battery pack 1 according to the present disclosure can include the battery management device 100 described above and one or more battery cells B. Furthermore, the battery pack 1 can further include electrical devices (relays, fuses, etc.) and a housing. The battery pack 1 can be applied to battery storage systems, vehicles, ESS (energy storage systems), and the like.

[0151] exist Figure 6 In an embodiment, the measuring unit 110 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. The measuring unit 110 may measure the positive electrode voltage of the battery cell B via the first sensing line SL1 and the negative electrode voltage of the battery cell B via the second sensing line SL2. Furthermore, the measuring unit 110 may measure the voltage of the battery cell B by calculating the difference between the measured positive electrode voltage and the measured negative electrode voltage.

[0152] In addition, the measuring unit 110 may be connected to a current measuring unit A via a third sensing line SL3. The current measuring unit A may be provided on a charge and discharge path of the battery cell B. For example, the current measuring unit A may be an ammeter or a shunt resistor.

[0153] In addition, the charging and discharging path may be a large current path through which the charging current and the discharging current of the battery cell B flow. Therefore, the measuring unit 110 may measure the current of the battery cell B via the third sensing line SL3 connected to the current measuring unit A, and measure the capacity of the battery cell B based on the measured current.

[0154] In addition, the discharge unit 130 may include a switching element and a discharge resistor constituting a discharge path of the battery cell B. Both ends of the discharge unit 130 may be connected to the charge and discharge path of the battery cell B.

[0155] For example, one end of the discharge unit 130 can be connected to the positive electrode of the battery cell B in the charge and discharge path. In addition, the other end of the discharge unit 130 can be connected to the negative electrode of the battery cell B in the charge and discharge path. In addition, the switching element included in the discharge unit 130 can open or close the discharge path of the battery cell B when its operating state is controlled by the control unit 120.

[0156] For example, in Figure 3 In the embodiment of the present invention, the discharge unit 130 can completely discharge the battery cell B2 to SOC 0% at the second time point T2. During this discharge process, the measurement unit 110 can measure the second capacity Q2 of the battery cell B.

[0157] Figure 7 is a diagram schematically illustrating a battery management method according to another embodiment of the present disclosure.

[0158] Preferably, each step of the battery management method can be performed by the battery management device 100. Hereinafter, for the convenience of description, the contents overlapping with the above description will be omitted or briefly described.

[0159] refer to Figure 7The battery management method includes a first measuring step (S100), a second measuring step (S200), a voltage deviation and capacity deviation calculating step (S300), a side reaction factor determining step (S400) and a side reaction type judging step (S500).

[0160] The first measurement step ( S100 ) is a step of measuring a first voltage of the battery cell B1 at a first time point T1 and may be performed by the measurement unit 110 .

[0161] For example, the first time point T1 may be a time point before the battery cell B1 is stored. That is, the measurement unit 110 may measure the first voltage of the battery cell B1 at the first time point T1 when the battery cell B1 starts to be stored.

[0162] The second measurement step ( S200 ) is a step of measuring the second voltage and the second capacity of the battery cell at a second time point T2 later than the first time point T1 , and may be performed by the measurement unit 110 .

[0163] For example, the second time point T2 may be a time point when the battery cell B2 is completely stored. Similar to the process of measuring the voltage of the battery cell B1 at the first time point T1, the measuring unit 110 may measure the voltage of the battery cell B2 at the second time point T2.

[0164] In addition, the control unit 120 may control the discharge unit 130 to discharge the battery cell B2. During the discharge of the battery cell B2, the measurement unit 110 may measure the discharge current of the battery cell B2 and accumulate the measured discharge current to measure a second capacity corresponding to the discharge amount of the battery cell B2.

[0165] The voltage deviation and capacity deviation calculating step ( S300 ) is a step in which a voltage deviation between a first voltage and a second voltage is calculated, and a capacity deviation between a first capacity corresponding to the first voltage and a second capacity is calculated, and may be performed by the control unit 120 .

[0166] The control unit 120 may calculate the voltage deviation by calculating the difference between the first voltage of the battery cell B1 at the first time point T1 and the second voltage of the battery cell B2 at the second time point T2. For example, the control unit 120 may calculate the voltage deviation by calculating the formula "first voltage - second voltage".

[0167] The control unit 120 can calculate the capacity deviation by calculating the difference between the first capacity of the battery cell B1 at the first time point T1 and the second capacity of the battery cell B2 at the second time point T2. For example, the control unit 120 can calculate the capacity deviation by calculating the formula "first capacity-second capacity".

[0168] Here, the control unit 120 may calculate the first capacity based on the first voltage. Specifically, the control unit 120 may estimate the first SOC corresponding to the first voltage using the battery curve BP. In addition, the control unit 120 may calculate the first capacity corresponding to the first voltage using the capacity Q0 of the BOL battery cell B0 and the estimated first SOC.

[0169] The side reaction factor determining step ( S400 ) is a step of determining a positive electrode side reaction factor and a negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation, and may be performed by the control unit 120 .

[0170] Specifically, the control unit 120 may calculate the capacity deviation Qi based on the difference between the capacity Q1 of the battery cell B1 at the first time point T1 and the capacity Q2 of the battery cell B2 at the second time point T2, and convert the calculated capacity deviation Qi into a negative electrode side reaction factor.

[0171] Furthermore, if the first SOC of battery cell B1 at the first time point T1 is greater than or equal to the standard SOC, the control unit 120 may determine the voltage-based capacity of the battery cell as the positive electrode side reaction factor based on the voltage deviation between the first time point T1 and the second time point T2. Here, the voltage deviation refers to the deviation between the first voltage of battery cell B1 at the first time point T1 and the second voltage of battery cell B2 at the second time point T2. The control unit 120 may calculate the voltage-based capacity by converting the voltage deviation into a capacity-based value using the battery curve BP.

[0172] Conversely, if the first SOC is less than the standard SOC, the control unit 120 may determine the value obtained by subtracting the capacity deviation Qi from the voltage-based capacity as the positive electrode side reaction factor. As described above, if the first SOC is less than the standard SOC, the capacity deviation Qi corresponding to the negative electrode side reaction may be included in the voltage-based capacity. Therefore, to accurately determine the positive electrode side reaction factor, the control unit 120 may determine the value obtained by subtracting the capacity deviation Qi from the voltage-based capacity as the positive electrode side reaction factor.

[0173] The side reaction type determination step ( S500 ) is a step of determining the side reaction type of the battery cell based on the positive electrode side reaction factor and the negative electrode side reaction factor, and may be performed by the control unit 120 .

[0174] For example, the control unit 120 may calculate the side reaction reference value using the formula "positive electrode side reaction factor ÷ negative electrode side reaction factor." Furthermore, if the side reaction reference value is equal to or greater than the standard value, the control unit 120 may determine that the side reaction type of the battery cell is a positive electrode side reaction. As another example, if the side reaction reference value is less than the standard value, the control unit 120 may determine that the side reaction type of the battery cell is a negative electrode side reaction.

[0175] The battery management method according to yet another embodiment of the present disclosure may further include an operation condition setting step (not shown).

[0176] The operating condition setting step is a step of setting operating conditions of the battery cell based on the side reaction type determined for the battery cell after the side reaction type determining step ( S500 ), and may be performed by the control unit 120 .

[0177] Specifically, because the conditions under which positive and negative electrode side reactions favorably occur differ, the control unit 120 can set different operating conditions for the battery cells based on the type of side reaction in the battery cells. In other words, to effectively prevent further degradation of the battery cells, the control unit 120 can appropriately set the operating conditions for the battery cells based on the type of side reaction in the battery cells.

[0178] For example, when the type of the side reaction of the battery cell is determined to be a positive electrode side reaction, the control unit 120 may be configured to reduce at least one of the upper limit SOC (maximum allowable SOC) and the upper limit voltage (maximum allowable voltage) of the battery cell.

[0179] On the contrary, when the type of the side reaction of the battery cell is determined to be a negative electrode side reaction, the control unit 120 may be configured to reduce the upper limit temperature (the maximum allowable temperature) of the battery cell.

[0180] The embodiments of the present disclosure described above cannot be implemented only by devices and methods, but can also be implemented by a program that implements functions corresponding to the configurations of the embodiments of the present disclosure or a recording medium that records the program. This program or recording medium can be easily implemented by a person skilled in the art based on the description of the embodiments described above.

[0181] 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.

[0182] In addition, those skilled in the art may make many substitutions, modifications and changes to the present disclosure described above without departing from the technical aspects of 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 achieve various variations.

[0183] (reference numerals)

[0184] 1: Battery pack

[0185] 100: Battery management equipment

[0186] 110: Measurement unit

[0187] 120: Control unit

[0188] 130: Discharge unit

[0189] 140: Storage unit

Claims

1. A battery management device, comprising: a measuring unit configured to measure a first voltage of a battery cell at a first time point, and to measure a second voltage and a second capacity of the battery cell at a second time point later than the first time point; as well as A control unit is configured to calculate a voltage deviation between the first voltage and the second voltage, calculate a capacity deviation between a first capacity corresponding to the first voltage and the second capacity, determine a positive electrode side reaction factor and a negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation, and determine a side reaction type of the battery cell based on the positive electrode side reaction factor and the negative electrode side reaction factor.

2. The battery management device according to claim 1, in, The control unit is configured to calculate a voltage-based capacity corresponding to the voltage deviation based on a battery curve representing a corresponding relationship between the state of charge (SOC) and voltage of the battery cell, and determine the positive electrode side reaction factor based on the voltage-based capacity or based on the voltage-based capacity and the capacity deviation according to the first voltage.

3. The battery management device according to claim 2, in, The control unit is configured to estimate a first SOC corresponding to the first voltage, compare the estimated first SOC with a preset standard SOC, and determine the positive electrode side reaction factor of the battery cell corresponding to a comparison result.

4. The battery management device according to claim 3, in, When the first SOC is equal to or greater than the standard SOC, the control unit is configured to determine the positive electrode side reaction factor based on the voltage-based capacity, and When the first SOC is less than the standard SOC, the control unit is configured to determine the positive electrode side reaction factor based on a difference between the voltage-based capacity and the calculated capacity deviation.

5. The battery management device according to claim 3, in, The control unit is configured to set an SOC at a starting point of a negative flat section in a difference curve representing a corresponding relationship between an SOC of the battery cell and a differential voltage with respect to the SOC as the standard SOC.

6. The battery management device according to claim 5, in, The control unit is configured to determine a target peak value included in a predetermined SOC section in the difference curve, and set an SOC corresponding to the determined target peak value as the standard SOC.

7. The battery management device according to claim 1, in, The control unit is configured to determine the negative electrode side reaction factor of the battery cell based on the capacity deviation.

8. The battery management device according to claim 1, in, The control unit is configured to calculate a side reaction reference value based on the positive electrode side reaction factor and the negative electrode side reaction factor, compare the calculated side reaction reference value with a preset side reaction standard value, and determine whether the side reaction type of the battery cell is the positive electrode side reaction or the negative electrode side reaction based on the comparison result.

9. The battery management device according to claim 1, in, The control unit is configured to set an operating condition for the battery cell based on the side reaction type determined for the battery cell.

10. The battery management device according to claim 9, in, When the side reaction type of the battery cell is determined to be the positive electrode side reaction, the control unit is configured to reduce at least one of an upper limit SOC and an upper limit voltage of the battery cell, and When the side reaction type of the battery cell is determined to be the negative electrode side reaction, the control unit is configured to reduce the upper limit temperature of the battery cell.

11. The battery management device according to claim 1 , further comprising: a discharging unit configured to discharge the battery cell at the second time point, The measuring unit is configured to measure the second capacity by measuring a discharge current of the battery cell when the battery cell is discharged at the second time point.

12. The battery management device according to claim 1, in, The battery cell is configured to maintain a predetermined temperature or higher from the first time point to the second time point. 13 . A battery pack comprising the battery management device according to claim 1 .

14. A battery management method, comprising: A first measurement step is used to measure a first voltage of the battery cell at a first time point; A second measuring step, for measuring a second voltage and a second capacity of the battery cell at a second time point later than the first time point; a voltage deviation and capacity deviation calculating step, for calculating a voltage deviation between the first voltage and the second voltage, and calculating a capacity deviation between a first capacity corresponding to the first voltage and the second capacity; a side reaction factor determining step for determining a positive electrode side reaction factor and a negative electrode side reaction factor of the battery cell based on the voltage deviation and the capacity deviation; as well as The side reaction type determination step is used to determine the side reaction type of the battery cell based on the positive electrode side reaction factor and the negative electrode side reaction factor.

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