Battery state estimation device and method

Abstract

An apparatus for estimating a state of a battery according to one embodiment of the present application includes a measurement unit configured to measure a voltage and a temperature of the battery and a charging current during a constant current charging process and a constant voltage charging process of the battery, and a control unit configured to determine whether the battery behaves abnormally according to a behavior of at least one of the voltage of the battery, the temperature of the battery, and the charging current during at least one of the constant current charging process and the constant voltage charging process, and determine whether lithium has been deposited in the battery based on a result of the determination of whether the battery behaves abnormally.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2021-0173264, filed in Korea on December 6, 2021, the disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to battery state estimation apparatus and methods, and more specifically, to battery state estimation apparatus and methods capable of determining whether lithium deposition has occurred in a battery. Background Technology

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

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

[0005] While much research has been conducted on batteries in terms of high capacity and high density, improving lifespan and safety is also important. Therefore, it is necessary to suppress the decomposition reaction of the electrolyte on the electrode surface and to prevent overcharging and over-discharging.

[0006] In particular, it is necessary to prevent lithium deposition on the surface of the negative electrode (lithium plating, Li plating). When lithium is deposited on the surface of the negative electrode, it can cause side reactions with the electrolyte and alter the battery's kinetic balance, potentially leading to battery degradation. Furthermore, since lithium metal deposition on the surface of the negative electrode can cause an internal short circuit, there is a risk of fire and explosion due to this short circuit. Therefore, it is necessary to develop a technology capable of detecting whether lithium metal has deposited on the surface of the negative electrode. Summary of the Invention

[0007] Technical issues

[0008] This disclosure aims to address the problems in the related technologies, and therefore aims to provide a battery state estimation device and method that can quickly determine whether lithium deposition has occurred by examining abnormal battery behavior.

[0009] These and other objects and advantages of this disclosure will become apparent from the following detailed description and will become more fully apparent from exemplary embodiments thereof. Likewise, it will be readily understood that the objects and advantages of this disclosure may be achieved by the means set forth in the appended claims and combinations thereof.

[0010] Technical solution

[0011] A battery state estimation device according to one aspect of the present disclosure may include: a measurement unit configured to measure battery voltage and temperature and charging current during a constant current charging process and a constant voltage charging process; and a control unit configured to determine whether abnormal behavior has occurred in the battery based on the behavior of at least one of the battery voltage, battery temperature and charging current during at least one of the constant current charging process and the constant voltage charging process, and to determine whether lithium deposition has occurred in the battery based on the determined abnormal behavior of the battery.

[0012] The control unit can be configured to determine lithium deposition in the battery when abnormal battery behavior is confirmed during either constant current charging or constant voltage charging.

[0013] The control unit can be configured to calculate the rate of change of voltage over time for each voltage of the battery measured by the measurement unit during constant current charging, and to determine that abnormal behavior is confirmed when the calculated rate of change of voltage is less than the standard rate of change of voltage.

[0014] The control unit can be configured to determine that abnormal behavior is confirmed when at least one of the voltage change rates calculated for each voltage of the battery is negative.

[0015] The control unit can be configured to calculate the rate of temperature change over time for each temperature of the battery measured by the measurement unit during constant current charging, and to determine that abnormal behavior is confirmed when the calculated rate of temperature change is equal to or greater than the standard rate of temperature change and the rate of voltage change is less than the standard rate of voltage change within a predetermined time period.

[0016] The control unit can be configured to calculate the rate of change of current over time for each current of the battery measured by the measurement unit during constant voltage charging, and to determine that abnormal behavior is confirmed when the calculated rate of change of current exceeds the standard rate of change of current.

[0017] The control unit can be configured to determine that abnormal behavior is confirmed when at least one of the current change rates calculated for each current of the battery is positive.

[0018] The control unit can be configured to calculate the rate of temperature change over time for each temperature of the battery measured by the measurement unit during constant voltage charging, and to determine that abnormal behavior is confirmed when the calculated rate of temperature change is equal to or greater than the standard rate of temperature change and the rate of current change exceeds the standard rate of current change within a predetermined time period.

[0019] The control unit can be configured to prevent the battery from charging and discharging when it is determined that lithium has deposited in the battery.

[0020] The control unit can be configured to: first determine whether abnormal behavior occurs in the battery during constant current charging, and if no abnormal behavior is confirmed in the battery during constant current charging, determine whether abnormal behavior occurs in the battery during constant voltage charging.

[0021] According to another aspect of this disclosure, a battery pack may include a battery state estimation device according to another aspect of this disclosure.

[0022] A battery state estimation method according to another aspect of this disclosure may include: a measurement step for measuring the battery voltage and temperature and charging current during a constant current charging process and a constant voltage charging process; an abnormal behavior judgment step for judging whether abnormal behavior has occurred in the battery based on the behavior of at least one of the battery voltage, battery temperature and charging current during at least one of the constant current charging process and the constant voltage charging process; and a lithium deposition judgment step for determining whether lithium deposition has occurred in the battery based on the abnormal behavior of the battery judged in the abnormal behavior judgment step.

[0023] Beneficial effects

[0024] According to one aspect of this disclosure, there are the following advantages: lithium deposition in the battery can be determined non-destructively based on measurement information during the battery charging process, and the use of the battery can be appropriately controlled based on the determination result.

[0025] Furthermore, according to one aspect of this disclosure, there is an advantage that lithium deposition in the battery can be quickly determined using only measurement information obtained during the battery charging process.

[0026] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand, based on the appended claims, other effects not mentioned herein. Attached Figure Description

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

[0028] Figure 1 This is a diagram schematically illustrating a battery state estimation device according to an embodiment of the present disclosure.

[0029] Figure 2 It is a diagram that schematically illustrates the battery charging process.

[0030] Figure 3 This is a diagram schematically illustrating the charging process of a first battery according to an embodiment of the present disclosure.

[0031] Figure 4This is a diagram schematically illustrating the charging process of a second battery according to an embodiment of the present disclosure.

[0032] Figure 5 This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0033] Figure 6 This is a diagram schematically illustrating a battery state estimation method according to yet another embodiment of the present disclosure. Detailed Implementation

[0034] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general or dictionary meanings, but rather as being interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, in accordance with the principle that inventors are permitted to appropriately define terms for best explanation.

[0035] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes only and are not intended to limit the scope of this disclosure. It should be understood that other equivalents and modifications may be made to this disclosure without departing from its scope.

[0036] In addition, when describing this disclosure, a detailed description of a relevant known element or function is omitted herein if it is considered to obscure the key subject matter of this disclosure.

[0037] Terms including ordinal numbers such as "first" and "second" can be used to distinguish one element from another among various elements, but are not intended to limit elements by these terms.

[0038] Throughout this specification, when a section is referred to as “containing” or “including” any element, unless otherwise specifically stated, this means that the section may also include other elements without excluding them.

[0039] Furthermore, throughout the specification, when one part is referred to as "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," or where another element is inserted between them.

[0040] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0041] Figure 1 This is a diagram schematically illustrating a battery state estimation device 100 according to an embodiment of the present disclosure.

[0042] Reference Figure 1 The battery state estimation device 100 according to embodiments of the present disclosure may include a measurement unit 110 and a control unit 120.

[0043] The measurement unit 110 can be configured to measure the battery voltage and temperature, as well as the charging current, during the constant current charging process and the constant voltage charging process.

[0044] Here, a battery refers to a physically separable, independent unit having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer cell can be considered a battery. Alternatively, a battery can refer to a battery module consisting of multiple units connected in series and / or parallel. In the following text, for ease of description, a battery will be described as referring to an independent unit.

[0045] Figure 2 It is a diagram that schematically illustrates the battery charging process.

[0046] Reference Figure 2 A typical battery charging process can include a constant current charging process (CC) and a constant voltage charging process (CV).

[0047] A constant current charging process can be described as charging a battery with a constant current until the battery voltage reaches a standard value. For example, in... Figure 2 In this embodiment, the battery can be charged with a constant current from time 0 to time t1. That is, from time 0 to time t1, the charging current remains constant, and the battery voltage can increase. Furthermore, at time t1, the battery voltage can reach the standard value Vth.

[0048] Constant voltage charging can be a process of charging a battery at a constant voltage after the battery voltage has reached a standard value. For example, in Figure 2 In this embodiment, the battery can be charged at a constant voltage starting from time t1. That is, starting from time t1, the battery voltage remains constant, and the charging current can be reduced. When the reduced charging current reaches a preset cutoff value, the constant voltage charging can be terminated.

[0049] The measurement unit 110 can be communicatively connected to the control unit 120. Additionally, the measurement unit 110 can send measurement information, including the measured charging current, battery voltage, and battery temperature, to the control unit 120.

[0050] The control unit 120 can be configured to determine whether abnormal behavior has occurred in the battery based on the behavior of at least one of the charging current, battery voltage, and battery temperature during at least one of the constant current charging process and the constant voltage charging process.

[0051] Here, abnormal behavior can refer to specific behaviors of charging current and / or battery voltage and / or battery temperature that do not occur during the normal constant current charging and constant voltage charging processes of a battery.

[0052] For example, Figure 2The embodiments illustrate the charging current, battery voltage, and battery temperature during constant-current charging and constant-voltage charging processes of a normal battery. The control unit 120 can control the behavior of at least one of the charging current, battery voltage, and battery temperature. Figure 2 The embodiments do not simultaneously determine abnormal behavior in the battery. Details of how the control unit 120 determines abnormal battery behavior in each of the constant current charging and constant voltage charging processes will be described later.

[0053] The control unit 120 can be configured to determine whether lithium deposition has occurred in the battery based on the identified abnormal behavior of the battery.

[0054] Specifically, when abnormal battery behavior is confirmed, the control unit 120 can determine that lithium metal has deposited in the corresponding battery. More specifically, the control unit 120 can determine that lithium metal has deposited on the surface of the negative electrode of the corresponding battery.

[0055] Typically, because an internal short circuit can occur in a battery when lithium metal deposits on the surface of the negative electrode, there is a risk of fire and explosion due to the internal short circuit. Therefore, the control unit 120 can be configured to prevent the charging and discharging of the battery when it is determined that lithium has deposited in the battery.

[0056] In other words, the control unit 120 can determine whether lithium deposition has occurred based on the abnormal behavior of the battery during the constant current charging process and constant voltage charging process, and prevent the battery from being used when lithium deposition is detected.

[0057] According to embodiments of the present disclosure, the battery state estimation device 100 can determine in a non-destructive manner whether lithium deposition has occurred in the battery based on measurement information during the battery charging process, and control the use of the battery.

[0058] Furthermore, since the battery state estimation device 100 determines whether lithium deposition has occurred in the battery based on measurement information obtained during charging, it has the advantage of not requiring measurement information obtained during multiple charging cycles to determine whether lithium deposition has occurred. In other words, the battery state estimation device 100 has the advantage of quickly determining whether lithium deposition has occurred in the battery using only measurement information obtained in one charging cycle.

[0059] Furthermore, since the battery state estimation device 100 can determine whether lithium deposition has occurred in the battery by analyzing measurement information obtained in a charging cycle, it does not require machine learning techniques for big data processing. Therefore, the battery state estimation device 100 has the advantage of being able to determine lithium deposition in the battery even with limited system resources.

[0060] Meanwhile, the control unit 120 included in the battery state estimation device 100 may optionally include application-specific integrated circuits (ASICs), another chipset, logic circuits, registers, communication modems, and data processing devices, as known in the art, to execute the various control logics disclosed below. Furthermore, when the control logic is implemented as software, the control unit 120 may be implemented as a set of program modules. In this case, the program modules may be stored in memory and executed by the control unit 120. The memory may be internal or external to the control unit 120 and may be connected to the control unit 120 in various known ways.

[0061] Additionally, the battery state estimation device 100 may also include a storage unit 130. The storage unit 130 may store data required for the operation and function of each component of the battery state estimation device 100, data generated during the execution of operations or functions, etc. The type of storage unit 130 is not particularly limited, as long as it is a known information storage device capable of recording, erasing, updating, and retrieving data. As examples, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. Furthermore, the storage unit 130 may store program code defining processes executable by the control unit 120.

[0062] The control unit 120 can be configured to determine lithium deposition in the battery when abnormal battery behavior is confirmed during either constant current charging or constant voltage charging.

[0063] For example, when abnormal battery behavior is confirmed during constant current charging and / or constant voltage charging, the control unit 120 can determine that lithium has been deposited in the battery.

[0064] Preferably, the control unit 120 can be configured to first determine whether abnormal behavior occurs in the battery during constant current charging, and if no abnormal behavior is confirmed in the battery during constant current charging, then determine whether abnormal behavior occurs in the battery during constant voltage charging.

[0065] Reference Figure 2 When charging the battery, a constant current charging process can be performed first, followed by a constant voltage charging process. Therefore, the control unit 120 can determine whether abnormal behavior occurs in the battery during the constant current charging process and then determine whether abnormal behavior occurs in the battery during the constant voltage charging process based on the measurement information received from the measurement unit 110 and the battery charging time.

[0066] In the following text, an embodiment in which the control unit 120 determines abnormal behavior of the battery during constant current charging will be described.

[0067] The control unit 120 can be configured to calculate the rate of change of voltage over time for each voltage of the battery measured by the measurement unit 110 during constant current charging.

[0068] Here, the rate of change of voltage can be the instantaneous rate of change of voltage over time. For example, if the voltage is expressed as V and the time as t, then the rate of change of voltage can be expressed as dV / dt.

[0069] The control unit 120 can be configured to determine that abnormal behavior is confirmed when the calculated rate of voltage change is less than the standard rate of voltage change.

[0070] Figure 3 This diagram schematically illustrates the charging process of a first battery according to an embodiment of the present disclosure. Here, the first battery may be a battery in which lithium metal is deposited on the surface of the negative electrode.

[0071] exist Figure 3 In this embodiment, the first battery can be charged with a constant current from time 0 to time t5, and then charged with a constant voltage starting from time t5. At time t2, the battery voltage can increase to Va, and at time t3, the battery voltage can decrease to Vb. After time t3, the battery voltage can increase again and reach the standard value Vth at time t5. That is, a constant current charging process CC can be performed from time 0 to time t5, and a constant voltage charging process CV can be performed after time t5.

[0072] Reference Figure 2 During normal constant-current charging of a battery, the charging current remains constant, while the voltage can increase continuously. In other words, during normal constant-current charging of a battery, the rate of voltage change can always be greater than or equal to the standard rate of voltage change. For example, the standard rate of voltage change can be 0 (V / s).

[0073] On the other hand, refer to Figure 3 In the first battery, during constant current charging, there may be a range where the voltage change rate is less than the standard voltage change rate. During time t2 to t3, the voltage change rate may be less than the standard voltage change rate. That is, the control unit 120 can be configured to determine that abnormal behavior has been confirmed when at least one of the voltage change rates calculated for each voltage of the battery is negative.

[0074] As in Figure 3In this embodiment, when a voltage change rate falls below the standard voltage change rate during constant current charging, the control unit 120 can confirm the abnormal behavior of the first battery based on the voltage change rate during constant current charging, since the first battery is not in a normal state. Furthermore, when the abnormal behavior of the first battery is confirmed, the control unit 120 can determine that lithium metal has deposited in the first battery and prevent the charging and discharging of the first battery.

[0075] More specifically, the control unit 120 can be configured to calculate the rate of temperature change over time for each temperature of the battery measured by the measurement unit 110 during constant current charging.

[0076] Here, the rate of change of temperature can be the instantaneous rate of change of temperature over time. For example, if the temperature is represented by T and the time by t, then the rate of change of temperature can be expressed as dT / dt.

[0077] The control unit 120 can be configured to determine that abnormal behavior is confirmed when the calculated rate of temperature change is greater than or equal to the standard rate of temperature change and the rate of voltage change is less than the standard rate of voltage change within a predetermined time period.

[0078] The battery voltage measured by measuring unit 110 can be the battery terminal voltage. The terminal voltage can be calculated using Ohm's law (V = IR, where V is voltage, I is current, and R is resistance). When the battery's temperature change rate is greater than or equal to the standard temperature change rate over a predetermined time period, the battery's internal resistance may decrease due to the high temperature. That is, considering Ohm's law (V = IR), since the charging current is constant during constant current charging, the battery voltage measured by measuring unit 110 may decrease when the battery's internal resistance decreases.

[0079] exist Figure 3 In this embodiment, it is assumed that the time period from t2 to t4 is greater than or equal to a predetermined time period, and the rate of temperature change during the time period from t2 to t4 is greater than or equal to a standard rate of temperature change. For example, the standard rate of temperature change is the rate of temperature change of 1°C per minute, and can be expressed as 1 (°C / minute). From time t2 to time t4, the temperature of the first battery may rise to or above the standard rate of temperature change. As the temperature of the first battery rises rapidly, the internal resistance of the first battery decreases, and as the internal resistance of the first battery decreases, the voltage of the first battery may decrease. That is, during constant current charging, as the temperature of the first battery rises rapidly, there may be a range where the rate of voltage change of the first battery is less than the standard rate of voltage change.

[0080] Therefore, the control unit 120 can determine abnormal battery behavior by considering both the battery's temperature change rate and voltage change rate. Additionally, the control unit 120 can estimate lithium metal deposition within the battery when abnormal battery behavior is confirmed.

[0081] The battery state estimation device 100 according to embodiments of the present disclosure has the advantage of rapidly estimating whether lithium deposition has occurred in the battery based on measurement information obtained during the battery charging process. Therefore, since the battery state estimation device 100 can quickly stop the operation of the battery in which lithium deposition has occurred, accidents such as fires or explosions can be prevented in advance.

[0082] The following describes an embodiment in which the control unit 120 determines abnormal behavior of the battery during constant voltage charging.

[0083] The control unit 120 can be configured to calculate the rate of change of current over time for each charging current measured by the measurement unit 110 during constant voltage charging.

[0084] Here, the rate of change of current can be the instantaneous rate of change of the charging current over time. For example, if the charging current is denoted as I and the time is denoted as t, then the rate of change of current can be expressed as dI / dt.

[0085] The control unit 120 can be configured to determine that abnormal behavior is confirmed when the calculated rate of change of current exceeds the standard rate of change of current.

[0086] Figure 4 This is a diagram schematically illustrating the charging process of a second battery according to an embodiment of the present disclosure. Here, the second battery may be a battery in which lithium metal is deposited on the surface of the negative electrode.

[0087] exist Figure 4 In this embodiment, the second battery can be charged with a constant current from time 0 to time t6 (constant current charging process CC), and then charged with a constant voltage from time t6 onwards (constant voltage charging process CV). From time 0 to time t6, the charging current can remain constant, and the voltage of the second battery can increase. At time t6, the voltage of the second battery reaches the standard value Vth, and from time t6 onwards, the voltage of the second battery can remain constant. During the period from time t6 to time t8, the charging current can decrease to Ia. Additionally, the charging current can increase from time t8, and the charging current can increase to Ib at time t9. After time t9, the charging current can decrease again.

[0088] Reference Figure 2During constant-voltage charging of a normal battery, the battery voltage remains unchanged, and the charging current can continuously decrease. Furthermore, charging can be terminated when the charging current reaches its cutoff value. In other words, during constant-voltage charging of a normal battery, the rate of change of current can always be less than or equal to the standard rate of change of current. For example, the standard rate of change of current can be 0 (mA / s).

[0089] On the other hand, refer to Figure 4 In the second battery, during constant-voltage charging, there may be a range where the rate of change of the charging current exceeds the standard rate of change of the current. During time t8 to t9, the rate of change of the current may exceed the standard rate of change of the current. That is, the control unit 120 can be configured to determine that abnormal behavior has been confirmed when at least one of the rates of change of current calculated for each charging current is positive.

[0090] As in Figure 4 In this embodiment, when the rate of change of current exceeds the standard rate of change of current during constant voltage charging, the control unit 120 can confirm the abnormal behavior of the second battery based on the rate of change of current during constant voltage charging, since the state of the second battery is not normal. Furthermore, when the abnormal behavior of the second battery is confirmed, the control unit 120 can determine that lithium metal has deposited in the second battery and prevent the charging and discharging of the second battery.

[0091] More specifically, the control unit 120 can determine abnormal battery behavior by further considering the rate of temperature change during constant-voltage charging. Here, since the rate of temperature change has already been described above, its redundant description will be omitted.

[0092] The control unit 120 can be configured to calculate the rate of temperature change over time for each temperature of the battery measured by the measurement unit 110 during constant voltage charging. Additionally, the control unit 120 can be configured to determine that abnormal behavior is confirmed when the calculated rate of temperature change is greater than or equal to a standard rate of temperature change within a predetermined time period and the rate of current change exceeds a standard rate of current change.

[0093] When the rate of temperature change of the battery is greater than or equal to the standard rate of temperature change within a predetermined time period, the internal resistance of the battery may decrease due to the high temperature. That is, considering Ohm's law (V=IR), since the battery voltage remains constant during constant voltage charging, the charging current measured by the measuring unit 110 may increase when the internal resistance of the battery decreases.

[0094] exist Figure 4In this embodiment, it is assumed that the time period from t7 to t10 is greater than or equal to a predetermined time period, and the rate of temperature change during the time period from t7 to t10 is greater than or equal to a standard rate of temperature change. For example, the standard rate of temperature change is the rate of temperature change of 1°C per minute, and can be expressed as 1 (°C / minute). From time t7 to time t10, the temperature of the second battery may rise to or exceed the standard rate of temperature change. As the temperature of the second battery rises rapidly, the internal resistance of the second battery decreases, and as the internal resistance of the second battery decreases, the charging current may increase. That is, during constant voltage charging, as the temperature of the second battery rises rapidly, there may be a range where the rate of current change exceeds the standard rate of current change.

[0095] Therefore, the control unit 120 can determine abnormal battery behavior by considering both the battery's temperature change rate and current change rate. Additionally, the control unit 120 can estimate lithium metal deposition within the battery when abnormal battery behavior is confirmed.

[0096] The battery state estimation device 100 according to embodiments of the present disclosure has the advantage of rapidly estimating whether lithium deposition has occurred in the battery based on measurement information obtained during the battery charging process. Therefore, since the battery state estimation device 100 can quickly stop the operation of the battery in which lithium deposition has occurred, accidents such as fires or explosions can be prevented in advance.

[0097] The battery state estimation device 100 according to this disclosure can be applied to a battery management system (BMS). That is, a BMS according to this disclosure may include the aforementioned battery state estimation device 100. In this configuration, at least some of the components of the battery state estimation device 100 can be implemented by supplementing or adding the functionality of components included in a conventional BMS. For example, the measurement unit 110, control unit 120, and storage unit 130 of the battery state estimation device 100 can be implemented as components of a BMS.

[0098] Furthermore, the battery state estimation device 100 according to this disclosure can be provided to a battery pack. That is, a battery pack according to this disclosure may include the aforementioned battery state estimation device 100 and one or more battery cells. In addition, the battery pack may also include electrical components (relays, fuses, etc.) and a housing.

[0099] Figure 5 This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0100] The positive terminal of battery 10 can be connected to the positive terminal P+ of battery pack 1, and the negative terminal of battery 10 can be connected to the negative terminal P- of battery pack 1.

[0101] The measurement unit 110 can be connected to a first sensing line SL1, a second sensing line SL2, a third sensing line SL3, and a fourth sensing line SL4. Specifically, the measurement unit 110 can be connected to the positive terminal of the battery 10 via the first sensing line SL1, and to the negative terminal of the battery 10 via the second sensing line SL2. The measurement unit 110 can measure the voltage of the battery 10 based on the voltage measured at each of the first sensing line SL1 and the second sensing line SL2.

[0102] Additionally, the measurement unit 110 can be connected to the current measurement unit A via the third sensing line SL3. For example, the current measurement unit A can be an ammeter or a shunt resistor capable of measuring the charging and discharging currents of the battery 10. The measurement unit 110 can measure the charging current of the battery 10 via the third sensing line SL3. Furthermore, the measurement unit 110 can measure the discharging current of the battery 10 via the third sensing line SL3.

[0103] In addition, the measurement unit 110 can measure the temperature of the battery 10 via the fourth sensing line SL4.

[0104] Preferably, the measuring unit 110 can measure the voltage, current and temperature of the battery 10 in the same cycle.

[0105] The charging and discharging device 2 may have one end connected to the positive terminal P+ of the battery pack 1 and the other end connected to the negative terminal P- of the battery pack 1. Therefore, the positive terminal of the battery 10, the positive terminal P+ of the battery pack 1, the charging and discharging device 2, the negative terminal P- of the battery pack 1, and the negative terminal of the battery 10 can be electrically connected.

[0106] For example, the charging and discharging device 2 can be electrically connected to the positive terminal P+ and the negative terminal P- of the battery pack 1 to charge and / or discharge the battery 10.

[0107] Figure 6 This is a diagram schematically illustrating a battery state estimation method according to yet another embodiment of the present disclosure.

[0108] Preferably, each step of the battery state estimation method can be performed by the battery state estimation device 100. In the following text, for ease of explanation, content overlapping with the previously described content will be omitted or briefly described.

[0109] Reference Figure 6 The battery state estimation method may include a measurement step (S100), an abnormal behavior judgment step (S200), and a lithium deposition judgment step (S300).

[0110] The measurement step (S100) is a step of measuring the battery voltage, temperature and charging current during the constant current charging process and constant voltage charging process, and can be executed by the measurement unit 110.

[0111] The abnormal behavior judgment step (S200) is a step to determine whether abnormal behavior has occurred in the battery based on the behavior of at least one of the battery voltage, battery temperature and charging current in at least one of the constant current charging process and the constant voltage charging process, and can be executed by the control unit 120.

[0112] The control unit 120 can determine whether abnormal behavior occurs in the battery during constant current charging and / or constant voltage charging.

[0113] Specifically, during constant current charging, the control unit 120 can determine whether abnormal behavior has occurred in the battery based on the battery voltage and temperature. Similarly, during constant voltage charging, the control unit 120 can determine whether abnormal behavior has occurred in the battery based on the charging current and battery temperature. This is because the charging current remains constant during constant current charging, and the battery voltage remains constant during constant voltage charging.

[0114] The lithium deposition determination step (S300) is a step used to determine whether lithium deposition has occurred in the battery based on the abnormal behavior of the battery determined in the abnormal behavior determination step (S200), and can be executed by the control unit 120.

[0115] When abnormal behavior is confirmed in the battery during the abnormal behavior judgment step (S200), the control unit 120 can determine that lithium metal has deposited in the battery. Subsequently, the control unit 120 can prevent the charging and discharging of the corresponding battery to stop its use. Therefore, since the use of the battery in which lithium metal has deposited can be stopped immediately, accidents such as fires or explosions can be prevented in advance.

[0116] Furthermore, since the battery state estimation method can be applied directly during battery charging, it is possible to quickly determine whether lithium deposition has occurred in the battery based on measurement information during the charging process. Preferably, since it is possible to determine whether lithium deposition has occurred in the battery during each charge, accidents caused by batteries with lithium deposition can be prevented in advance.

[0117] The embodiments of this disclosure described above can be implemented not only by devices and methods, but also by a program for implementing functions corresponding to the configurations of the embodiments of this disclosure, or by a recording medium on which the program is recorded. Based on the above description of the embodiments, those skilled in the art can readily implement the program or recording medium.

[0118] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific examples indicate preferred embodiments of this disclosure, they are given by way of illustration only, as various changes and modifications within the scope of this disclosure will become apparent to those skilled in the art based on the detailed description.

[0119] Furthermore, since those skilled in the art can substitute, modify, and change the above-described disclosure in various ways without departing from the technical concept of the disclosure, the disclosure is not limited to the above embodiments and drawings, and all or some embodiments can be selectively combined to enable various modifications.

[0120] (Explanation of reference numerals in the attached diagram)

[0121] 1: Battery pack

[0122] 2: Charging and discharging device

[0123] 10: Battery

[0124] 100: Battery state estimation device; 110: Measurement unit

[0125] 120: Control Unit

[0126] 130: Storage unit

Claims

1. A battery state estimation device, comprising: A measurement unit configured to measure the voltage and temperature of the battery and the charging current during constant current charging and constant voltage charging processes. as well as A control unit is configured to: determine whether abnormal behavior occurs in the battery based on the behavior of at least one of the battery voltage and the charging current during at least one of the constant current charging process and the constant voltage charging process, as well as the behavior of the battery temperature; and determine whether lithium deposition has occurred in the battery based on the determined abnormal behavior of the battery, wherein... The control unit is further configured to: first determine whether abnormal behavior occurs in the battery during the constant current charging process, and if no abnormal behavior is confirmed in the battery during the constant current charging process, determine whether abnormal behavior occurs in the battery during the constant voltage charging process.

2. The battery state estimation device according to claim 1, in, The control unit is configured to determine lithium deposition in the battery when abnormal behavior of the battery is confirmed during either the constant current charging process or the constant voltage charging process. Furthermore, the control unit is configured to: calculate the rate of change of voltage over time for each voltage of the battery measured by the measurement unit during the constant current charging process, and determine that the abnormal behavior is confirmed when the calculated rate of change of voltage is less than the standard rate of change of voltage.

3. The battery state estimation device according to claim 2, in, The control unit is configured to determine that the abnormal behavior is confirmed when at least one of the voltage change rates calculated for each voltage of the battery is negative.

4. The battery state estimation device according to claim 1, in, The control unit is configured to determine lithium deposition in the battery when abnormal behavior of the battery is confirmed during either the constant current charging process or the constant voltage charging process. Furthermore, the control unit is configured to: calculate the rate of change of current over time for each current of the battery measured by the measurement unit during the constant voltage charging process, and determine that the abnormal behavior is confirmed when the calculated rate of change of current exceeds the standard rate of change of current.

5. The battery state estimation device according to claim 4, in, The control unit is configured to determine that the abnormal behavior is confirmed when at least one of the current change rates calculated for each current of the battery is positive.

6. A battery state estimation device, comprising: A measurement unit configured to measure the voltage and temperature of the battery and the charging current during constant current charging and constant voltage charging processes. as well as A control unit is configured to: determine whether abnormal behavior occurs in the battery based on the behavior of at least one of the battery voltage and the charging current during at least one of the constant current charging process and the constant voltage charging process, as well as the behavior of the battery temperature; and determine whether lithium deposition has occurred in the battery based on the determined abnormal behavior of the battery, wherein... The control unit is further configured to: calculate the rate of change of voltage over time for each voltage of the battery measured by the measurement unit during the constant current charging process; calculate the rate of change of temperature over time for each temperature of the battery measured by the measurement unit during the constant current charging process; and determine that the abnormal behavior is confirmed when the calculated rate of change of temperature is equal to or greater than the standard rate of change of temperature within a predetermined time period and the calculated rate of change of voltage is less than the standard rate of change of voltage.

7. A battery state estimation device, comprising: A measurement unit configured to measure the voltage and temperature of the battery and the charging current during constant current charging and constant voltage charging processes. as well as A control unit is configured to: determine whether abnormal behavior occurs in the battery based on the behavior of at least one of the battery voltage and the charging current during at least one of the constant current charging process and the constant voltage charging process, as well as the behavior of the battery temperature; and determine whether lithium deposition has occurred in the battery based on the determined abnormal behavior of the battery, wherein... The control unit is further configured to: calculate the rate of change of current over time for each current of the battery measured by the measurement unit during the constant voltage charging process; calculate the rate of change of temperature over time for each temperature of the battery measured by the measurement unit during the constant voltage charging process; and determine that the abnormal behavior is confirmed when the calculated rate of change of temperature is equal to or greater than the standard rate of change of temperature within a predetermined time period and the calculated rate of change of current exceeds the standard rate of change of current.

8. The battery state estimation device according to any one of claims 1, 6, and 7, in, The control unit is configured to determine lithium deposition in the battery when abnormal behavior of the battery is confirmed during either the constant current charging process or the constant voltage charging process.

9. The battery state estimation device according to claim 8, in, The control unit is configured to prevent the charging and discharging of the battery when it is determined that lithium has deposited in the battery.

10. A battery pack comprising a battery state estimation device according to any one of claims 1, 6 and 7.

11. A battery state estimation method, comprising: Measurement steps are used to measure the voltage and temperature of the battery and the charging current during the constant current charging process and the constant voltage charging process of the battery. The abnormal behavior judgment step is used to determine whether abnormal behavior has occurred in the battery based on the behavior of at least one of the battery voltage and the charging current during at least one of the constant current charging process and the constant voltage charging process, as well as the behavior of the battery temperature. First, determine whether any abnormal behavior occurs in the battery during the constant current charging process. If no abnormal behavior is confirmed in the battery during the constant current charging process, then determine whether any abnormal behavior occurs in the battery during the constant voltage charging process. as well as The lithium deposition determination step is used to determine whether lithium deposition has occurred in the battery based on the abnormal behavior of the battery determined in the abnormal behavior determination step.

12. A battery state estimation method, comprising: Measurement steps are used to measure the voltage and temperature of the battery and the charging current during the constant current charging process and the constant voltage charging process of the battery. The abnormal behavior judgment step is used to determine whether abnormal behavior has occurred in the battery based on the behavior of at least one of the battery voltage and the charging current during at least one of the constant current charging process and the constant voltage charging process, as well as the behavior of the battery temperature. For each voltage of the battery measured during the constant current charging process, calculate the rate of change of voltage over time; for each temperature of the battery measured during the constant current charging process, calculate the rate of change of temperature over time; and when the calculated rate of change of temperature is equal to or greater than the standard rate of change of temperature within a predetermined time period and the calculated rate of change of voltage is less than the standard rate of change of voltage, determine that the abnormal behavior is confirmed. as well as The lithium deposition determination step is used to determine whether lithium deposition has occurred in the battery based on the abnormal behavior of the battery determined in the abnormal behavior determination step.

13. A battery state estimation method, comprising: Measurement steps are used to measure the voltage and temperature of the battery and the charging current during the constant current charging process and the constant voltage charging process of the battery. The abnormal behavior judgment step is used to determine whether abnormal behavior has occurred in the battery based on the behavior of at least one of the battery voltage and the charging current during at least one of the constant current charging process and the constant voltage charging process, as well as the behavior of the battery temperature. For each current measured during the constant voltage charging process, the rate of change of current over time is calculated; for each temperature measured during the constant voltage charging process, the rate of change of temperature over time is calculated; and when the calculated rate of change of temperature is equal to or greater than the standard rate of change of temperature within a predetermined time period and the calculated rate of change of current exceeds the standard rate of change of current, the abnormal behavior is determined to be confirmed. as well as The lithium deposition determination step is used to determine whether lithium deposition has occurred in the battery based on the abnormal behavior of the battery determined in the abnormal behavior determination step.

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