Battery management device and battery management method

Abstract

The invention discloses a battery management device and a battery management method. A battery management apparatus according to the present disclosure includes: a setting control unit configured to set a reference voltage, which is a reference for determining a risk caused by a rapid increase in gas; a measurement unit configured to measure a voltage of the battery cell; and a diagnosis unit configured to diagnose the battery cell as a dangerous cell in which a degree of risk caused by a rapid increase in gas is equal to or higher than a predetermined level when a state in which a voltage of the battery cell is higher than a reference voltage lasts for a first reference time or longer.

Description

Technical Field

[0001] The present disclosure relates to battery state diagnosis and management, and more particularly to a battery management apparatus and method for diagnosing a dangerous condition caused by a rapid increase in gas in a battery using characteristics of a differential profile line.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0137997, filed in Korea on October 16, 2023, the disclosure of which is incorporated herein by reference. Background Art

[0003] In recent years, the demand for portable electronic products using electric power as a power source, such as laptop computers, cameras, and mobile phones, has increased rapidly, and with the widespread use of mobile robots, electric bicycles, electric carts, and electric vehicles, many studies are being conducted on high-performance secondary batteries that can be repeatedly charged and discharged.

[0004] Commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, etc. Among them, lithium secondary batteries have little or no memory effect compared to nickel-based batteries. Therefore, compared to other types of secondary batteries, they are attracting more in-depth research and have a wider range of applications because of their advantages of being rechargeable whenever convenient, having a very low self-discharge rate, and having a high energy density and operating voltage.

[0005] In recent years, secondary batteries have been widely used not only in small devices such as mobile electronic devices but also in medium and large-sized devices such as electric vehicles or energy storage systems (ESS).

[0006] Contrary to energy generation methods based on fossil fuels, secondary batteries generate energy through an electrochemical reaction. Therefore, secondary batteries cannot maintain their performance at the beginning of life (BOL), and gradually deteriorate or age as the charge / discharge cycle continues or repeats.

[0007] As the use (charging / discharging) of the battery continues, the usability decreases due to a decrease in capacity or output degradation, and safety also acts as a risk factor. To maintain the continuity of normal operation, control of limited use, determination of when to replace, and improvement of the efficiency of battery reuse or recycling, it is necessary to accurately diagnose the current state of the battery.

[0008] Due to battery degradation and external factors such as defects in the manufacturing process or external shocks, gas may be generated in the battery.

[0009] When gas is generated in a battery, the state of the battery becomes unstable, leading to rapid changes such as inability to operate or pressure increase, accompanied by a temperature rise, and critical safety issues of the battery itself such as fire or explosion.

[0010] A gas detection sensor or a physical sensor for detecting a volume change of a battery cell has been mainly used to detect gas in a battery.

[0011] Since these methods basically rely on gas release to the atmosphere or external changes, they cannot detect internal gas without any physical changes, and they correspond to post-event detection methods, so they may not be optimal for preliminary or preventive actions or measures or management.

[0012] On the other hand, there are some publicly disclosed methods for diagnosing gas generation by using electrical properties of a battery such as ohmic resistance, resistance change rate, or capacitance change rate, but these methods require complex processing (such as impedance calculation based on complex numbers) to use electrochemical impedance spectroscopy (EIS). Summary of the Invention

[0013] Technical Problem

[0014] The present disclosure is designed to solve the above problems under the above background art, and thus, the present disclosure aims to provide a battery management device and method for quickly and reliably diagnosing a gas generation state of a battery cell by using a differential profile of the battery cell obtained and generated by a simple method.

[0015] The technical problems to be solved by the present disclosure are not limited to the above problems, and those skilled in the art will clearly understand these and other problems from the following description.

[0016] Technical Solution

[0017] A battery management device according to an aspect of the present disclosure includes: a setting control unit configured to set a reference voltage, which is a reference for determining a risk caused by a rapid increase in gas; a measurement unit configured to measure a voltage of a battery cell; and a diagnosis unit configured to diagnose the battery cell as a dangerous cell with a risk level equal to or higher than a predetermined level caused by a rapid increase in gas when the voltage of the battery cell is higher than the reference voltage for a first reference time or longer.

[0018] The setting control unit may include: a data processing unit configured to generate a differential profile indicating the correspondence between the voltage and the differential capacity of the battery cell using a battery profile indicating the correspondence between the voltage and the capacity of the battery cell; a characteristic point selection unit configured to select a characteristic point from the differential profile at which the differential capacity is maximum in the high voltage range; and a reference setting unit configured to set a reference voltage based on the voltage of the characteristic point.

[0019] The diagnostic unit may be configured to apply a first reference time differently according to the magnitude of the voltage of the battery cell. The diagnostic unit may be configured that as the voltage difference between the voltage of the battery cell and the reference voltage becomes larger, a shorter time is applied as the first reference time.

[0020] The characteristic point selection unit may be configured to use the updated differential profile to select a characteristic point when the differential profile is updated. The reference setting unit may be configured to update the reference voltage using the voltage of the characteristic point.

[0021] The battery management device may further include a management control unit configured to control a discharge process to be performed on the battery cell when the battery cell is diagnosed as a dangerous cell with a risk level equal to or higher than a predetermined level caused by a rapid increase in gas.

[0022] The battery management device may further include a temperature sensor configured to measure the temperature of the battery cell. The diagnostic unit may be configured to diagnose the battery cell as a dangerous cell with a risk level equal to or higher than a predetermined level caused by a rapid increase in gas when the state where the temperature of the battery cell is higher than the reference temperature continues for a second reference time or longer.

[0023] The diagnostic unit may be configured to apply a second reference time differently according to the magnitude of the temperature of the battery cell. The diagnostic unit may be configured that as the temperature difference between the temperature of the battery cell and the reference temperature becomes larger, a shorter time is applied as the second reference time.

[0024] A battery pack according to another aspect of the present disclosure includes the battery management device.

[0025] An electric vehicle according to another aspect of the present disclosure includes the battery pack.

[0026] A battery management method according to another aspect of the present disclosure includes the following steps: setting a reference voltage, which is a reference for determining a risk caused by a rapid increase in gas; measuring the voltage of a battery cell; and diagnosing the battery cell as a dangerous cell with a risk level equal to or higher than a predetermined level caused by a rapid increase in gas when the state where the voltage of the battery cell is higher than the reference voltage continues for a first reference time or longer.

[0027] The steps of setting a reference voltage may include the following steps: generating a differential profile indicating the correspondence between the voltage and the differential capacity of a battery cell using a battery profile indicating the correspondence between the voltage and the capacity of the battery cell; selecting a characteristic point from the differential profile at which the differential capacity is the largest in a high voltage range; and setting the reference voltage based on the voltage of the characteristic point.

[0028] Advantages of the Invention

[0029] According to an embodiment of the present disclosure, gas generation in a battery cell can be effectively diagnosed by a simpler method because characteristic changes caused by gas generation can be systematically applied to the data analysis process.

[0030] In addition, according to an embodiment of the present disclosure, the current state of a battery cell, such as internal gas generation, can be more easily and quickly diagnosed by analyzing a differential profile representing the characteristics of the battery cell and using the differential profile, and the current state of the dynamically changing battery cell can be more significantly reflected by using a differential profile updated in time series.

[0031] In addition, according to an embodiment of the present disclosure, by differently applying a reference time, which is one of the parameters for determining the risk level of gas generation, according to the voltage of the battery cell or / and the temperature of the battery cell, the safety of the battery cell can be more effectively ensured.

[0032] Furthermore, the process of the present disclosure can be implemented by a software process that can be installed in a battery management system (BMS) commonly used in battery devices or systems, thereby providing higher scalability. Brief Description of the Drawings

[0033] The drawings illustrate exemplary embodiments of the present disclosure and are used in conjunction with the following detailed description to provide a more effective understanding of the technical aspects of the present disclosure, and thus the present disclosure should not be construed as being limited to the drawings.

[0034] Figure 1 is a detailed block diagram of a battery management device according to an embodiment of the present disclosure.

[0035] Figure 2 is Figure 1 a detailed block diagram of the setting control unit shown in

[0036] Figure 3 is a flowchart showing a process of diagnosing the state of a battery cell according to an embodiment of the present disclosure.

[0037] Figure 4is a flowchart showing an example of a process for setting a reference voltage, which is a reference for determining a risk caused by a rapid increase in gas.

[0038] Figure 5 is a flowchart showing a diagnostic process of a battery cell according to another embodiment of the present disclosure.

[0039] Figure 6 is a diagram showing an example of a differential profile of a battery cell.

[0040] Figure 7 is Figure 6 an enlarged view of the high voltage region shown in

[0041] Figure 8 is a diagram showing an example of a gas increase ratio according to the temperature and voltage of a battery cell.

[0042] Figure 9 is a diagram referred to in the process of differently determining a reference time according to an embodiment of the present disclosure. Detailed Description

[0043] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms or words used in the specification and the appended claims should not be construed as limited to the general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle that allows the inventor to appropriately define the terms for the best explanation.

[0044] Therefore, the embodiments described herein and the illustrations shown in the drawings are exemplary embodiments for describing the technical aspects of the present disclosure and are not intended to be restrictive. Thus, it should be understood that various other equivalents and modifications can be made thereto when submitting this application.

[0045] In addition, when determining that a specific detailed description of a related known element or function may obscure or make unclear the subject matter of the present disclosure, the detailed description is omitted.

[0046] Unless the context clearly indicates otherwise, the terms "comprising" and "including" as used in this specification specify the presence of the stated elements, but do not exclude the presence or addition of one or more other elements.

[0047] In addition, as used herein, the term "processor" refers to a processing unit having at least one function or operation, and can be implemented by hardware or software or a combination thereof.

[0048] In addition, throughout the specification, it should also be understood that when an element is referred to as being "connected to" another element, it can be directly connected to the other element or an intermediate element may be present.

[0049] Figure 1 is a detailed block diagram of a battery management device according to an embodiment of the present disclosure, and Figure 3 is a flowchart showing a process of diagnosing the state of a battery cell according to an embodiment of the present disclosure.

[0050] First, reference will be made to Figure 1 and the related drawings to describe in detail the components of the battery management device 100 of the present disclosure and the processes performed by the components.

[0051] As Figure 1 shown, the battery management device 100 of the present disclosure may include a measurement unit 110, a setting control unit 120, a diagnosis unit 130, a management control unit 140, a temperature sensor 150, and a historical information storage unit 160.

[0052] Before the detailed description of the present disclosure, it should be noted that the battery management device 100 can be implemented by various combinations of electronic elements or components such as storage devices, computing processing devices, or input / output devices (ASICs, chip sets, logic circuits, registers, communication modems, MCUs, etc.).

[0053] Therefore, Figure 1 each component of the battery management device 100 shown in Figure 3 should be understood as components that are functionally or logically rather than physically distinct.

[0054] That is, each component shown in the drawings corresponds to a logical component for effectively describing the technical aspects of the present disclosure. Therefore, it should be understood that each component falls within the scope of the present disclosure when the functions performed by the logical components of the present disclosure can be achieved even when each component is combined or separated, and it should also be understood that components performing the same or similar functions fall within the scope of the present disclosure regardless of whether the names are the same.

[0055] In addition, the battery diagnosis method or battery management method according to the present disclosure can be fully implemented as a set of processes or algorithms related to data processing, manipulation, control, calculation, or input / output, and can be implemented as Figure 1 a combination of the logical components shown in

[0056] The battery management device 100 can be configured to diagnose the current state of the battery cell 50, such as gas generation (rapid gas increase), and according to one embodiment, can be configured to generate and output diagnostic data of the battery cell 50 for system connection with other components or modules / devices. Hereinafter, the battery cell 50 for diagnosing the state may be referred to as the "target cell".

[0057] A plurality of target cells 50 diagnosed and managed by the battery management device 100 can be included in an upper layer of an assembly such as a battery cell assembly, a battery module, or a battery pack by an electrical connection method of series, parallel, or a combination thereof.

[0058] The setting control unit 120 sets a reference voltage (S300, see Figure 3 ) as a reference for gas generation or rapid gas increase.

[0059] Figure 8 is a graphical representation of data indicating a trend of the gas increase ratio, which is the ratio of the amount of gas generated when a new cell (i.e., a battery cell at BOL) is idle for a predetermined time at voltages in a high voltage region HV at two or more non-standard temperatures (e.g., 60 °C and 70 °C) to the amount of gas generated when the new cell is idle for a predetermined time at a standard voltage (e.g., 3.90 V) at a standard temperature (e.g., room temperature).

[0060] The amount of gas (or gas generation rate) generated in the target cell 50 has a close relationship with the voltage environment and / or temperature environment of the target cell 50. It can be seen from Figure 8 that as the temperature and voltage are higher, the amount of gas generated for the same time increases. In other words, under the same temperature condition, the amount of gas generated increases as the voltage of the target cell 50 increases, and under the same voltage condition, the amount of gas generated increases as the temperature of the target cell 50 increases.

[0061] Therefore, based on the results of a plurality of pre-tests performed on battery cells having substantially the same specifications as the target cell 50, a reference voltage or a voltage at which gas is generated at a dangerous level can be preset. As an example, Figure 8 the two change rates of the two curves for 60 °C and 70 °C shown in

[0062] Preferably, a reference voltage is set to further reflect the safety level of the application device in which the target cell 50 is installed, the aging degree, capacity characteristics, SOH, etc. of the target cell 50. Specific embodiments of setting the reference voltage of the present disclosure will be described below.

[0063] The measurement unit 110 is electrically connected to the target cell 50 to measure the voltage across the target cell 50 (referred to as "cell voltage" or "terminal voltage") (S310) and output the measured voltage. The measurement unit 110 may include various known means for measuring the electrical characteristic values (voltage, current, etc.) of the target cell 50, and various electrical connection methods may be applied according to the type of electrical characteristic values.

[0064] When the current voltage of the target cell 50 is lower than the reference voltage (S320), the diagnosis unit 130 identifies a stable state where the risk degree of gas generation does not exceed the threshold, and diagnoses the corresponding target cell 50 as a normal cell (S345).

[0065] In addition, as a result of performing the process of comparing the current voltage of the target cell 50 with the reference voltage (S320), when the current voltage of the target cell 50 is higher than the reference voltage (hereinafter referred to as "the first event") but the first event does not last for the first reference time or longer (the value of S330 is "no"), the diagnosis unit 130 may diagnose the corresponding target cell 50 as a normal cell (S345).

[0066] Through this exemplary configuration, the present disclosure can effectively filter signal processing errors caused when the voltage of the target cell 50 is temporarily high or due to the presence of noise components.

[0067] The first reference time can be preset in the same manner as the above-mentioned reference voltage by considering the characteristics of the target cell 50 itself or various parameters of the application device to which the target cell 50 is applied.

[0068] On the contrary, when the first event (i.e., the state where the current voltage of the target cell 50 is higher than the reference voltage) lasts for the first reference time or longer (the value of S330 is "yes"), the diagnosis unit 130 diagnoses the corresponding target cell 50 as a dangerous cell with a risk degree caused by a rapid increase in gas being a predetermined level or higher (S340).

[0069] When a specific target cell 50 is diagnosed as a dangerous cell, the diagnosis unit 130 may generate diagnosis data and / or historical information and store it in the historical information storage unit 160, in which the identification information of the specific target cell 50, the time information designated as a dangerous cell, the reference voltage at the corresponding time, and the voltage information of the target cell 50 are connected to each other.

[0070] According to one embodiment, the historical information can be used for system connection with other components or modules / devices and can be used in the process of determining the deterioration time of the target cell 50 or identifying the characteristic changes of the target cell 50 in the time series.

[0071] When the diagnosis unit 130 diagnoses a specific target cell 50 as a dangerous cell, the management control unit 140 can perform control to limit the charging / discharging (capacity range, usage time range, maximum and minimum voltage ranges, etc.) of the corresponding target cell 50. Additionally, when the target cell 50 is diagnosed as a dangerous cell, the management control unit 140 can perform control to execute a discharging process (S350) on the target cell 50. The discharging process can be performed by applying a discharging pulse or by the method of electrically connecting a discharging load across the target cell 50.

[0072] In response to a high degree of safety risk determined due to gas generation or a rapid increase in gas in the target cell 50, the present disclosure can discharge the target cell 50 before a critical safety issue occurs to more effectively take preventive actions or measures.

[0073] The above process of the present disclosure can be iteratively applied until a preset termination condition such as forced termination, system shutdown, or emergency event generation is satisfied (the value of S360 is "no").

[0074] Figure 2 Yes Figure 1 is the detailed block diagram of the setting control unit 120 shown in Figure 4 is a flowchart showing an example of the process of setting a reference voltage, which is a reference for determining the risk caused by a sharp increase in gas. Hereinafter, embodiments of setting the reference voltage of the present disclosure will be described in detail with reference to the accompanying drawings.

[0075] The setting control unit 120 corresponds to the component that sets the above reference voltage, so as to fully reflect the characteristics of the target cell 50 to improve the accuracy of dangerous cell determination and the corresponding management and control processes.

[0076] Reference Figure 2 FIG., the setting control unit 120 may include a profile processing unit 121, a data processing unit 123, a characteristic point selection unit 125, a reference setting unit 127, and an information storage unit 129. Figure 2 Each component shown in FIG. may correspond to the logical components as pointed out above.

[0077] The profile processing unit 121 is configured to obtain the battery profile (charging / discharging profile) of the target cell 50. Here, the battery profile refers to the profile indicating the correspondence between the voltage (voltage) and capacity (or SOC) of the target cell 50.

[0078] The battery profile can be stored in the profile processing unit 121 of the present disclosure for future use by receiving an input from a separate device or module.

[0079] In addition, according to one embodiment, as Figure 1 shown, by the measurement unit 110 electrically connected to the target cell 50, the electrical characteristic values of the target cell 50 can be acquired and recorded (S400), and a battery profile of the target cell 50 can be generated based on the time series of the recorded electrical characteristic values (S410).

[0080] The SOC indicates the ratio of the current capacity to the maximum capacity and is expressed as 0 to 1 or 0% to 100%, and can be generated by various techniques and skills such as current integration, equivalent circuit models, or Kalman filters, and according to one embodiment, information about the SOC can be generated to further reflect temperature information.

[0081] Since the battery profile represents the correspondence between the voltage and the capacity (or SOC) of the target cell 50, according to one embodiment, the battery profile can be a data set in which the voltage values and the capacity values measured at the same time are mapped to each other.

[0082] The data processing unit 123 performs a function process on the battery profile to generate a differential profile (S420) indicating the correspondence between the voltage of the target cell 50 and the differential capacity corresponding to the voltage. Figure 6 Shows the differential profiles of each of two battery cells (cell A and cell B) having different states of health (SOH). The battery cell (cell A) can be a new cell with an SOH of 100%, and the battery cell (cell B) can be a degraded cell with an SOH less than 100%.

[0083] According to one embodiment, the data processing unit 123 can be configured to acquire a differential profile (hereinafter referred to as a "reference profile") indicating the correspondence between the voltage of a new battery cell at BOL corresponding to the specification or type of the target cell 50 and its differential capacity.

[0084] The differential capacity is obtained by differentiating the capacity with respect to the voltage and can be expressed as "dQ / dV", and its unit can be [Ah / V]. When the battery profile on which the differential profile is based is a profile generated during charging, where the X-axis of the two-dimensional coordinate is set to the voltage and the Y-axis is set to the differential capacity, the differential profile (differential capacity profile) can be represented in the form of a two-dimensional curve graph, as Figure 6 shown.

[0085] When function processes such as symmetric transformation or variable transformation are applied, the technical aspects of the present disclosure can also be applied when generating a differential profile based on a battery profile generated during discharging.

[0086] When gas is generated in the target cell 50, the inherent characteristics may be mainly presented in the high voltage region of the target cell 50. Therefore, in order to fully reflect these characteristics, it is preferable to use the data (a part of the differential profile) corresponding to the high voltage region HV equal to or higher than a predetermined voltage of interest (e.g., 4.00 V) in the differential profile (see Figure 6 ).

[0087] For this purpose, the characteristic point selection unit 125 can select (determine) the characteristic point (S430) of the differential voltage representing the generated gas amount of the corresponding target cell 50 by using the data (differential profile) corresponding to the high voltage region HV in the differential profile.

[0088] Specifically, the characteristic point can be the maximum point with the largest differential capacity in the voltage region equal to or greater than the voltage of interest, that is, the inflection point with the largest function value (differential capacity).

[0089] The inflection point can refer to the point where the trend of the slope changes based on the curve graph or curve shape of the cell profile, that is, the point where the sign of the slope increase ratio changes (from positive to negative or from negative to positive). For example, in the curve graph of the cell profile, the inflection point refers to the point where uneven or curved shape changes occur, that is, the shape changes of convex (upward convex) and concave (downward convex).

[0090] The inflection point is the point where the change in the inherent characteristics of the target cell 50 occurs, and can serve as an important parameter point indicating the inherent state or characteristics of the target cell 50.

[0091] The voltage of interest is the voltage used as a reference for distinguishing the high voltage region HV from the entire available voltage region, and can be variably set according to the specifications or types of the target cell 50. For example, based on a cell with a designed voltage upper limit of 4.2 V, the voltage of interest can be set to 4.0 V lower than the voltage upper limit.

[0092] Based on Figure 6 the two differential profiles shown, two characteristic points P1, P2 for two cells (Cell A, Cell B) are shown in Figure 7 . As a reference, Figure 7 is Figure 6 an enlarged view of the high voltage region HV in the differential profile shown in

[0093] When the characteristic point of the target cell 50 is selected, the reference setting unit 127 can set the reference voltage based on the voltage of the characteristic point (hereinafter referred to as "the first voltage") (S440).

[0094] Based on Figure 7In the embodiment shown, when the target cell 50 is a battery cell (Cell A), RV1 is the first voltage, and when the target cell 50 is a battery cell (Cell B), RV2 is the first voltage.

[0095] The reference voltage can be set to a value substantially the same as the voltage of the characteristic point, but for safety reasons, it can be set to a value lower or higher than the voltage of the characteristic point by adding or subtracting a predetermined weight, and according to one embodiment, it can be set within a predetermined range.

[0096] The target cell 50 cannot maintain its performance at BOL and gradually deteriorates or ages as the charge / discharge cycle continues or repeats. Due to the change in the behavior characteristics, the voltage of the characteristic point where the first voltage or differential capacity is the largest in the high-voltage region of the differential profile can change over time.

[0097] Therefore, compared with maintaining a fixed reference voltage determined through the initial setting process, the reference voltage that changes over time can preferably reflect the current state of the target cell 50 more accurately.

[0098] For this purpose, the data processing unit 123 periodically updates (generates) the above differential profile. When the differential profile is updated, the characteristic point selection unit 125 can be configured to select the characteristic point based on the current time using the latest generated differential profile.

[0099] In addition, through this process, when the characteristic point is updated in time series, the reference setting unit 127 can be configured to update the reference voltage using the first voltage that has changed due to the update of the characteristic point.

[0100] As described above, in order to effectively filter unnecessary processes, when the first event (the state where the current voltage of the target cell is higher than the reference voltage) lasts for the first reference time or longer, the present disclosure is configured to diagnose the corresponding target cell 50 as a dangerous cell and perform a discharge process.

[0101] In this regard, when the current voltage of the target cell 50 is higher than the reference voltage, the safety of the target cell 50 can be more effectively ensured by applying the first reference time differently according to the magnitude of the current voltage (instead of applying the same length of the first reference time regardless of the current voltage of the target cell 50).

[0102] As referenced Figure 8As described, the amount of gas generated (or the gas generation rate) tends to increase as the voltage of the target monomer 50 increases. Therefore, in order to more effectively reflect the behavioral characteristics of battery control, the diagnosis unit 130 may adjust the first reference time according to the magnitude of the current voltage of the target monomer 50. The diagnosis unit 130 may be configured to determine a shorter time as the first reference time as the difference between the current voltage of the target monomer 50 and the reference voltage becomes larger. That is, the diagnosis unit 130 may determine the first reference time based on relationship data defining a predetermined positive correspondence between the voltage difference between the current voltage of the target monomer 50 and the reference voltage and the first reference time.

[0103] Figure 9 is a diagram referred to in the process of differently determining the reference time according to an embodiment of the present disclosure.

[0104] Reference Figure 9 In the example shown in, as the voltage of the target monomer 50 is higher, that is, as the voltage difference between the current voltage of the target monomer 50 and the reference voltage becomes larger, the first reference time for diagnosing the risk caused by the rapid increase of gas can be shorter. From the corresponding perspective, as the voltage difference between the current voltage of the target monomer 50 and the reference voltage becomes smaller, the first reference time for diagnosing the risk caused by the rapid increase of gas can be longer.

[0105] As Figure 9 shown in, according to an embodiment, a plurality of sections (a first section to a fourth section) of voltage and / or temperature may be predefined, and first reference times with different lengths may be applied according to the section to which the current voltage of the target monomer 50 belongs.

[0106] That is, when the current voltage of the target monomer 50 is much higher than the reference voltage, a shorter time may be applied to the first reference time. On the contrary, when the current voltage of the target monomer 50 is higher than the reference voltage but their voltage difference is not too large, a longer time may be applied as the first reference time. Therefore, the efficiency of the risk diagnosis and control process can be increased, and the safety of the target monomer 50 or the assembly or module of the target monomer 50 during operation can be improved.

[0107] Information about the reference voltage set by the reference setting unit 127 may be stored in the information storage unit 129 together with the differential profile for use in subsequent processes or application processes.

[0108] Figure 5 is a flowchart showing the diagnosis process of a battery cell according to another embodiment of the present disclosure.

[0109] As referred to above Figure 8As described, since the gas in the target monomer 50 tends to increase as the temperature increases, it is preferable to perform different controls according to the temperature environment of the target monomer 50.

[0110] To this end, the control unit 120 sets a reference temperature (S500) as a reference for gas generation or rapid gas increase.

[0111] As described above, based on the results of multiple pre-tests performed on battery monomers having substantially the same specifications as the target monomer 50, the reference temperature or the temperature at which gas is generated at a dangerous level can be preset.

[0112] Similar to the above reference voltage, it is preferable to set the reference temperature so as to further reflect the safety level of the application device in which the target monomer 50 is installed, the aging degree of the target monomer 50, the capacity characteristics or SOH, the temperature environment of the module or device in which the target monomer 50 is installed, and the like.

[0113] The temperature sensor 150 measures the current temperature of the target monomer 50 (S510) and outputs the measured temperature information to the diagnosis unit 130.

[0114] When the current temperature of the target monomer 50 is lower than the reference temperature (the value of S520 is "no"), the diagnosis unit 130 recognizes that the risk level of gas generation is not very high and diagnoses the corresponding target monomer 50 as a normal monomer (S545).

[0115] In addition, when it is determined in step S520 that the current temperature of the target monomer 50 is higher than the reference temperature (hereinafter referred to as "second event") but the second event does not last for a second reference time or longer (the value of S530 is "no"), the diagnosis unit

[0116] With this exemplary configuration, the present disclosure can effectively filter out risks that do not persist, for example, the temperature of the target monomer 50 is temporarily high.

[0117] The second reference time can be set in the same manner as the above first reference time or reference temperature, considering the characteristics of the target monomer 50 itself or various parameters of the application device to which the target monomer 50 is applied.

[0118] On the contrary, in the case of the second event, that is, the state where the current temperature of the target monomer 50 is higher than the reference temperature lasts for a second reference time or longer (the value of S530 is "yes"), the diagnosis unit 130 diagnoses the target monomer 50 as a dangerous monomer with a risk level equal to or higher than a predetermined level caused by rapid gas increase (S540).

[0119] When a specific target monomer 50 is diagnosed as a dangerous monomer, the diagnosis unit 130 may generate diagnosis data or historical information and store it in the historical information storage unit 160, where the identification information of the specific target monomer 50, the time information designated as a dangerous monomer, and the reference voltage information at the corresponding time are connected to each other in the diagnosis data or historical information.

[0120] When the diagnosis unit 130 diagnoses a specific target monomer 50 as a dangerous monomer, the management control unit 140 may perform control to limit the charging / discharging of the dangerous monomer (capacity range, usage time range, maximum and minimum voltage ranges, etc.). The management control unit 140 may perform a cooling process (S550) on the corresponding dangerous monomer through the operation of a cooling fan, the circulation of cooling water, or the operation of a cooling device.

[0121] As referenced Figure 8 As described, as the temperature of the target monomer 50 increases, the amount of gas generated (or the gas generation rate) tends to increase. To more effectively reflect the behavioral characteristics regarding battery control, the diagnosis unit 130 may apply a second reference time differently according to the magnitude of the current temperature of the target battery monomer 50. Specifically, when the current temperature of the target monomer 50 is higher than the reference temperature, the diagnosis unit 130 may be configured to use a shorter time as the second reference time as the temperature difference between the current temperature of the target monomer 50 and the reference temperature becomes larger.

[0122] As Figure 9 shown, as the temperature of the target monomer 50 is higher, that is, as the difference between the current temperature of the target monomer 50 and the reference temperature becomes larger, the diagnosis unit 130 may decrease the second reference time. From the corresponding perspective, as the difference between the current temperature of the target monomer 50 and the reference temperature becomes smaller, the diagnosis unit 130 may increase the second reference time.

[0123] As Figure 9 shown, according to one embodiment, multiple sections (a first section to a fourth section) may be set, and a second reference time with a different length may be applied according to the section to which the current temperature of the target monomer 50 belongs.

[0124] The above embodiments, that is, the embodiments of diagnosing the target monomer 50 using the temperature information of the target monomer 50 and the reference temperature and performing subsequent processes, may be applied independently of the above embodiments of diagnosing the target monomer 50 using the current voltage and reference voltage of the target monomer 50, and according to one embodiment, they may be applied together.

[0125] The battery management device 100 can be applied to a battery management system (BMS). That is, the BMS according to the present disclosure may include the above-mentioned 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 to components included in a conventional BMS.

[0126] In addition, the battery management device 100 can be equipped in a battery pack. That is, the battery pack according to the present disclosure may include the above-mentioned battery management device 100 and at least one battery cell, battery assembly, battery module, or battery cell group.

[0127] In addition, the battery management device 100 can be equipped in an electric vehicle such as a hybrid electric vehicle. That is, the electric vehicle according to the present disclosure may include the battery management device 100 or the battery pack according to the present disclosure. In addition, in addition to the battery management device or the battery pack, the electric vehicle according to the present disclosure may further include any other components included in the electric vehicle. For example, in addition to the device according to the present disclosure, the electric vehicle according to the present disclosure may further include a vehicle body, a motor, or a controller such as an electronic control unit (ECU).

[0128] Although the present disclosure has been described above with respect to a limited number of embodiments and drawings, the present disclosure is not limited thereto, and those skilled in the art can make various modifications and changes within the scope of the technical aspects of the present disclosure and the appended claims and their equivalents.

[0129] To emphasize the technical aspects of the present disclosure, the drawings used for the description of the present disclosure and the illustration of the embodiments of the present disclosure may be shown in an exaggerated form, but it should be understood that obviously, those of ordinary skill in the art can make various modifications and changes with respect to the foregoing description and the illustration in the drawings.

[0130] In addition, as used herein, the terms first, second, upper, lower, and top-bottom are terms of the concept of tools for distinguishing each component (element) from each other, and they are not terms for indicating a specific priority order or sequence or physically distinguishing each component (element) according to an absolute standard.

Claims

1. A battery management device, comprising: A setting control unit configured to set a reference voltage, which is a reference for determining a risk caused by a rapid increase in gas; A measurement unit configured to measure the voltage of a battery cell; And A diagnosis unit configured to diagnose the battery cell as a dangerous cell with a risk level equal to or higher than a predetermined level caused by the rapid increase in gas when the voltage of the battery cell is higher than the reference voltage for a first reference time or longer.

2. The battery management device according to claim 1, Among them, The setting control unit includes: A data processing unit configured to generate a differential profile indicating the correspondence between the voltage and the differential capacity of the battery cell using a battery profile indicating the correspondence between the voltage and the capacity of the battery cell; A characteristic point selection unit configured to select a characteristic point from the differential profile at which the differential capacity is the largest; and A reference setting unit configured to set the reference voltage based on the voltage of the characteristic point.

3. The battery management device according to claim 1, Among them, The diagnosis unit is configured to: Apply the first reference time differently according to the magnitude of the voltage of the battery cell, Wherein, the larger the voltage difference between the voltage of the battery cell and the reference voltage, the shorter the time is applied as the first reference time.

4. The battery management device according to claim 2, Among them, The characteristic point selection unit uses the updated differential profile to select the characteristic point when the differential profile is updated, and Wherein, the reference setting unit uses the voltage of the characteristic point to update the reference voltage.

5. The battery management device according to claim 1, further comprising: A management control unit configured to control a discharge process to be performed on the battery cell when the battery cell is diagnosed as the dangerous cell with a risk level equal to or higher than the predetermined level caused by the rapid increase in gas.

6. The battery management device according to claim 1, further comprising: A temperature sensor configured to measure the temperature of the battery cell, Wherein, the diagnosis unit is configured to: Diagnose the battery cell as the dangerous cell with a risk level equal to or higher than the predetermined level caused by the rapid increase in gas when the state where the temperature of the battery cell is higher than the reference temperature lasts for a second reference time or longer.

7. The battery management device according to claim 6, Among them, The diagnosis unit is configured to: Apply the second reference time differently according to the magnitude of the temperature of the battery cell, Wherein, the larger the temperature difference between the temperature of the battery cell and the reference temperature, the shorter the time is applied as the second reference time.

8. A battery pack, comprising the battery management device according to any one of claims 1 to 7.

9. An electric vehicle, comprising the battery pack according to claim 8.

10. A battery management method, comprising the following steps: Setting a reference voltage, which is a reference for determining the risk caused by a rapid increase in gas; Measuring the voltage of a battery cell; And When the state where the voltage of the battery cell is higher than the reference voltage lasts for a first reference time or longer, diagnosing the battery cell as a dangerous cell with a risk level equal to or higher than a predetermined level caused by the rapid increase in gas.

11. The battery management method according to claim 10, Among them, The step of setting the reference voltage comprises the following steps: Using a battery profile indicating the correspondence between the voltage and the capacity of the battery cell to generate a differential profile indicating the correspondence between the voltage and the differential capacity of the battery cell; Selecting a characteristic point from the differential profile, at which the differential capacity is the largest; and Setting the reference voltage based on the voltage of the characteristic point.

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