Apparatus and method for diagnosing battery

Abstract

Disclosed is an apparatus for diagnosing a battery, the apparatus including: a curve obtaining unit configured to obtain a charging curve representing a correspondence relationship between a voltage and a current of the battery measured during a charging process; and a control unit configured to calculate a first CC capacity and a first CV capacity according to a charging curve, calculate a capacity change rate of the first CC capacity and the first CV capacity based on a pre-stored second CC capacity and a pre-stored second CV capacity, diagnose a state of the battery based on the calculated capacity change rate and a preset correction coefficient, and determine a state of the battery based on the calculated capacity change rate and the preset correction coefficient. And setting the use condition of the battery according to the diagnosis result.

Description

Technical Field

[0001] This application is based on and claims priority to Korean Patent Application No. 10-2024-0014210, filed with the Korean Intellectual Property Office on January 30, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to an apparatus and method for diagnosing a battery, and more specifically, to an apparatus and method for diagnosing the state of a battery. Background Technology

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

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

[0005] Extensive research is underway on the high capacity and high density of these batteries, but improving lifespan and safety is equally important. To enhance battery safety, technologies for accurately diagnosing the current state of the battery are needed. Summary of the Invention

[0006] Technical issues

[0007] This disclosure is designed to address problems in the relevant field, and therefore, it is intended to provide an apparatus and method for diagnosing batteries that diagnoses the state of the battery based on its charge capacity.

[0008] These and other objects and advantages of this disclosure will be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of this disclosure. Furthermore, it will be readily understood that the objects and advantages of this disclosure can be achieved by the means set forth in the appended claims and combinations thereof.

[0009] Technical solution

[0010] In one aspect of this disclosure, an apparatus for diagnosing a battery is provided, the apparatus comprising: a curve acquisition unit configured to acquire a charging curve representing the correspondence between voltage and current of the battery measured during charging; and a control unit configured to calculate a first CC capacity and a first CV capacity based on the charging curve, calculate a capacity change rate of the first CC capacity and the first CV capacity based on pre-stored second CC capacity and second CV capacity, diagnose the state of the battery based on the calculated capacity change rate and a preset correction coefficient, and set battery usage conditions according to the diagnostic results.

[0011] The control unit can be configured to calculate the CC capacity difference between the first CC capacity and the second CC capacity, calculate the CV capacity difference between the first CV capacity and the second CV capacity, and calculate the capacity change rate by calculating the ratio of the CC capacity difference to the CV capacity difference.

[0012] The control unit can be configured to calculate the decrease in the first CC capacity relative to the second CC capacity as the CC capacity difference, and to calculate the increase in the first CV capacity relative to the second CV capacity as the CV capacity difference.

[0013] The control unit can be configured to calculate the corrected rate of change by multiplying the rate of change of capacity by a correction factor, compare the corrected rate of change with a preset threshold, and diagnose the state of the battery based on the comparison result.

[0014] The control unit can be configured to diagnose the battery state as normal when the correction rate of change is greater than or equal to a threshold.

[0015] The control unit can be configured to diagnose the battery state as abnormal when the correction rate of change is less than a threshold.

[0016] The control unit can be configured to output a notification signal to issue a warning of a sudden drop when the battery status is diagnosed as abnormal.

[0017] The control unit can be configured to change the preset charging current for the battery when the rate of change of correction is less than a threshold.

[0018] The control unit can be configured to change the upper limit of the charging current to a value obtained by multiplying the correction rate of change by the upper limit of the charging current.

[0019] The correction factor can be preset based on the changes in the battery's CC capacity and CV capacity during a preset number of reference cycles.

[0020] The correction factor can be preset as the ratio of the representative change in CV capacity to the representative change in CC capacity during a preset number of reference cycles.

[0021] In another aspect of this disclosure, a battery pack is provided that includes means for diagnosing the battery according to embodiments of this disclosure.

[0022] In another aspect of this disclosure, a vehicle is provided that includes means for diagnosing a battery according to embodiments of this disclosure.

[0023] In another aspect of this disclosure, a method for diagnosing a battery is provided, the method comprising: a curve acquisition step, which acquires a charging curve representing the correspondence between voltage and current of the battery measured during charging; a capacity calculation step, which calculates a first CC capacity and a first CV capacity based on the charging curve; a capacity change rate calculation step, which calculates the capacity change rate of the first CC capacity and the first CV capacity based on pre-stored second CC capacity and second CV capacity; a diagnosis step, which diagnoses the state of the battery based on the calculated capacity change rate and a preset correction coefficient; and a usage condition setting step, which sets the usage conditions of the battery based on the diagnosis results.

[0024] Beneficial effects

[0025] According to one aspect of this disclosure, the apparatus for diagnosing batteries has the advantage that, since the apparatus uses correction coefficients to diagnose the state of the battery based on the CC capacity and CV capacity, the state of the battery can be diagnosed in a non-destructive manner in a non-complex way.

[0026] Furthermore, according to one aspect of this disclosure, the device for diagnosing batteries has the advantage of detecting batteries with a high probability of sudden drops at an early stage.

[0027] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the description of the claims other effects not mentioned. Attached Figure Description

[0028] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve 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 these drawings.

[0029] Figure 1 This is a schematic diagram illustrating an apparatus for diagnosing a battery according to an embodiment of the present disclosure.

[0030] Figure 2 This is a schematic diagram illustrating a charging curve according to an embodiment of the present disclosure.

[0031] Figures 3 to 5 This is a diagram schematically showing the diagnostic results of the first to third batteries.

[0032] Figure 6This is a schematic diagram illustrating a battery pack according to another embodiment of the present disclosure.

[0033] Figure 7 This is a schematic diagram illustrating a vehicle according to yet another embodiment of the present disclosure.

[0034] Figure 8 This is a schematic diagram illustrating a method for diagnosing a battery according to yet another embodiment of the present disclosure. Detailed Implementation

[0035] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but rather should be described based on the meanings and concepts corresponding to the technical aspects of this disclosure, on the principle that the inventors are allowed to define the terms appropriately for the best interpretation.

[0036] Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of this disclosure. It should be understood that other equivalents and modifications may be made thereto without departing from the scope of this disclosure.

[0037] Furthermore, in describing this disclosure, detailed descriptions of relevant known elements or functions are omitted where such descriptions would obscure the key subject matter of the disclosure.

[0038] Ordinal terms, such as “first” and “second”, can be used to distinguish one element from another among various elements, but are not intended to limit these elements by the terminology.

[0039] Throughout this specification, when a section is referred to as “containing” or “including” any element, it means that the section may also include other elements, without excluding other elements, unless otherwise specifically stated.

[0040] Furthermore, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected”, but also includes the case where they are “indirectly connected” between each other with another element inserted in between.

[0041] The preferred embodiments of this disclosure will be described in detail below with reference to the accompanying drawings.

[0042] Figure 1 This is a schematic diagram illustrating a device 100 for diagnosing a battery according to an embodiment of the present disclosure.

[0043] Reference Figure 1 The device 100 for diagnosing batteries may include a curve acquisition unit 110 and a control unit 120.

[0044] Here, "battery" refers to an individual cell that has a negative terminal and a positive terminal and can be physically separated. For example, a lithium-ion battery or a lithium polymer battery can be considered a battery. Furthermore, the type of battery can be cylindrical, prismatic, or pouch. Additionally, "battery" can also refer to a battery bank, battery module, or battery pack in which multiple cells are connected in series and / or parallel. Hereafter, for ease of explanation, "battery" will be interpreted as referring to a single, independent cell.

[0045] The curve acquisition unit 110 can be configured to acquire a charging curve CP, which represents the correspondence between the battery voltage and current measured during the charging process.

[0046] For example, the charging curve CP is a curve that shows the relationship between voltage (V) and current (C) when the battery is charged from a preset start-of-charge state (SOC) or 0% to a preset end-of-charge state (SOC) or 100%. In other words, the charging curve CP represents the relationship between the battery's charging voltage and charging current.

[0047] For example, there is no particular limitation on the charging rate (C) for generating the charging curve CP. However, preferably, the battery should be charged at a low rate to obtain a more accurate charging curve CP. For example, the charging curve CP can be generated during the charging process at 0.05C.

[0048] For example, the curve acquisition unit 110 can directly receive the charging curve CP from the outside. That is, the curve acquisition unit 110 can obtain the charging curve CP by receiving the charging curve CP through a wired and / or wireless connection to the outside.

[0049] As another example, the curve acquisition unit 110 can receive battery information regarding the battery's voltage and current. Furthermore, the curve acquisition unit 110 can generate a charging curve CP based on the received battery information. In other words, the curve acquisition unit 110 can directly generate the charging curve CP based on the battery information to obtain the charging curve CP.

[0050] Figure 2 This is a schematic diagram illustrating the charging curve CP according to an embodiment of the present disclosure.

[0051] For example, in Figure 2 In one embodiment, the battery can be charged until the voltage reaches 4.2V from 3.0V. Specifically, the battery can be charged with a constant current (CC) before the voltage reaches a preset threshold voltage (Vth) at time point t1, and can be charged with a constant voltage (CV) from time point t1 to the end time point t2. Here, the threshold voltage (Vth) is also referred to as the cutoff voltage.

[0052] The curve acquisition unit 110 can be connected to communicate with the control unit 120. For example, the curve acquisition unit 110 can be connected to the control unit 120 via wired and / or wireless means. The curve acquisition unit can send the acquired charging curve CP to the control unit 120.

[0053] The control unit 120 can be configured to calculate the first CC capacity and the first CV capacity based on the charging curve CP.

[0054] Specifically, the control unit 120 can calculate the first CC capacity and the first CV capacity of the battery based on the charging curve CP using a current counting method (ampere counting method or coulomb counting method). Here, the first CC capacity is the charging capacity of the battery while it is being CC charged, and the first CV capacity is the charging capacity of the battery while it is being CV charged.

[0055] For example, in Figure 2 In one embodiment, the control unit 120 can calculate the first CC capacity by integrating the current quantity from time point 0 to t1. Furthermore, the control unit 120 can calculate the first CV capacity by integrating the current quantity from time point t1 to t2.

[0056] The control unit 120 can be configured to calculate the capacity change rate of the first CC capacity and the first CV capacity based on the pre-stored second CC capacity and second CV capacity.

[0057] Specifically, the second CC capacity is the pre-stored CC capacity of the battery, and refers to the CC capacity of the battery calculated at a previous point in time. Similarly, the second CV capacity is the pre-stored CV capacity of the battery, and refers to the CV capacity of the battery calculated at a previous point in time. For example, suppose the current cycle is the nth cycle (where n is a natural number greater than or equal to 2). The control unit 120 can calculate the first CC capacity and the first CV capacity in the nth cycle. Furthermore, the CC capacity calculated in the (n-1)th cycle can be the pre-stored second CC capacity, and the calculated CV capacity can be the pre-stored second CV capacity. In this embodiment, although it is described that the cycle in which the second CC capacity and the second CV capacity are calculated (the (n-1)th cycle) and the cycle in which the first CC capacity and the first CV capacity are calculated (the nth cycle) are separated by one cycle, it should be noted that the cycle interval can vary depending on the battery's diagnostic cycle, diagnostic conditions, diagnostic methods, etc.

[0058] Specifically, the control unit 120 can be configured to calculate the CC capacity difference between the first CC capacity and the second CC capacity.

[0059] Preferably, the CC capacity may decrease as the battery deteriorates. Since the second CC capacity is calculated before the first CC capacity, the second CC capacity may be greater than or equal to the first CC capacity. Therefore, the control unit 120 can be configured to calculate the decrease in the first CC capacity relative to the second CC capacity as the CC capacity difference. For example, the control unit 120 can calculate the CC capacity difference using the formula "second CC capacity - first CC capacity".

[0060] In addition, the control unit 120 can be configured to calculate the CV capacity difference between the first CV capacity and the second CV capacity.

[0061] Preferably, the CV capacity may increase as the battery deteriorates. Since the second CV capacity is calculated before the first CV capacity, the second CV capacity may be less than or equal to the first CV capacity. Therefore, the control unit 120 can be configured to calculate the increase in the first CV capacity relative to the second CV capacity as the CV capacity difference. For example, the control unit 120 can calculate the CV capacity difference using the formula "first CV capacity - second CV capacity".

[0062] Finally, the control unit 120 can be configured to calculate the capacity change rate by calculating the ratio of the CC capacity difference to the CV capacity difference.

[0063] For example, the control unit 120 can calculate the capacity change rate by calculating the ratio of the CV capacity difference to the CC capacity difference. In other words, the control unit 120 can calculate the capacity change rate using the formula "CV capacity difference ÷ CC capacity difference".

[0064] As another example, the control unit 120 can calculate the capacity change rate by calculating the ratio of the CC capacity difference to the CV capacity difference. That is, the control unit 120 can calculate the capacity change rate by calculating the formula "CC capacity difference ÷ CV capacity difference".

[0065] In the following text, for ease of explanation, it is assumed that the rate of change of capacity is the ratio of the CV capacity difference to the CC capacity difference.

[0066] The control unit 120 can be configured to diagnose the state of the battery based on the calculated rate of capacity change and a preset correction factor.

[0067] Specifically, the control unit 120 can be configured to calculate the corrected rate of change by multiplying the capacity change rate by a correction factor. In other words, the corrected rate of change is the value obtained by multiplying the capacity change rate by a correction factor.

[0068] For example, the control unit 120 can use the following formula 1 to calculate the correction rate of change.

[0069] [Formula 1]

[0070]

[0071] Here, n is a natural number greater than or equal to 2, and is a factor representing the time point of the cycle. CC n QV is the rate of change of correction for the nth cycle. n Let QV be the first CV capacity of the nth cycle. n-1 This is the capacity of the second CV in the nth cycle. QC n QC is the capacity of the first CC in the nth cycle. n-1 Let be the capacity of the second CC in the (n-1)th cycle, and α be the correction factor. Furthermore, the capacity change rate is "(QV)". n - QV n-1 ) ÷ (QC n-1 - QC n )".

[0072] In addition, correction coefficients can be preset based on the changes in the battery's CC capacity and CV capacity during a preset number of reference cycles.

[0073] Specifically, the correction factor can be preset as the ratio of the representative change in CV capacity to the representative change in CC capacity during the reference cycle number.

[0074] Preferably, a correction factor can be set for the battery in the BOL (Burning End of Life) state. That is, the correction factor can be set based on the representative changes in CV capacity and CC capacity during a reference number of cycles from the first cycle of the battery. Here, the representative changes can be the minimum change, the maximum change, the average change, or the intermediate change.

[0075] For example, assuming a preset reference cycle count of 10 and the representative change is the average change, the changes in CV capacity and CC capacity of the battery from the first cycle to the tenth cycle can be calculated. Since the changes in CV capacity and CC capacity are calculated for each cycle starting from the second cycle, a total of nine changes in CV capacity and CC capacity can be calculated. The average of the nine changes in CV capacity can be set as the representative change in CV capacity, and the average of the nine changes in CC capacity can be set as the representative change in CC capacity. Furthermore, a correction factor can be set based on the ratio of the average change in CV capacity to the average change in CC capacity.

[0076] For example, the correction factor can be preset according to the following formula 2.

[0077] [Formula 2]

[0078]

[0079] Here, α is the correction coefficient, dQC ref Let dQV be a representative change in CC capacity. ref This represents the representative change in CV capacity.

[0080] The control unit 120 can be configured to compare the corrected rate of change with a preset threshold (th) and diagnose the state of the battery based on the comparison result.

[0081] Specifically, the control unit 120 can compare the magnitude of the correction rate of change with a threshold (th). Here, the threshold (th) is a measure to distinguish the state of the battery as normal or abnormal based on the correction rate of change.

[0082] For example, if the correction rate of change is greater than or equal to a threshold (th), the control unit 120 can diagnose the battery state as normal. As another example, if the correction rate of change is less than the threshold (th), the control unit 120 can be configured to diagnose the battery state as abnormal.

[0083] Theoretically, when the CC capacity decreases as the battery deteriorates, the CV capacity should increase by the amount of decrease. However, if the battery actually deteriorates, the CV capacity will not increase by the amount of decrease in CC capacity. Therefore, the control unit 120 uses a correction factor to correct the rate of capacity change calculated for the nth and (n-1)th cycles, and determines whether the battery deterioration is normal or abnormal based on the corrected rate of change.

[0084] For example, suppose the average change (average decrease) in CC capacity is 1, the average change (average increase) in CV capacity is 0.5, and the threshold (th) is set to 1. In this case, according to Formula 2, the correction coefficient can be preset to 2. If the correction rate of change, calculated by multiplying the capacity change rate by the correction coefficient, is 1 or greater, the control unit 120 can diagnose the battery state as normal. Conversely, if the correction rate of change is less than 1, the control unit 120 can diagnose the battery state as abnormal.

[0085] In other words, if the corrected rate of change, calculated by multiplying the capacity change rate by the correction coefficient, is less than the threshold (th), the balance between the decrease in CC capacity and the increase in CV capacity is significantly disrupted. Therefore, in this situation, the control unit 120 can diagnose the battery state as abnormal.

[0086] The advantage of the device 100 for diagnosing batteries is that it diagnoses the state of the battery non-destructively using a simple method, because the device uses correction factors to diagnose the state of the battery based on the CC capacity and CV capacity.

[0087] Meanwhile, the curve acquisition unit 110 and control unit 120 included in the battery diagnostic device 100 include processors, application-specific integrated circuits (ASICs), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the art, for executing various control logics performed in this disclosure. Furthermore, when the control logic is implemented as software, the curve acquisition unit 110 and control unit 120 can be implemented as a set of program modules. In this case, the program modules can be stored in memory and executed by the curve acquisition unit 110 and control unit 120. The memory can be internal or external to the curve acquisition unit 110 and control unit 120, and can be connected to the curve acquisition unit 110 and control unit 120 in various known ways.

[0088] Furthermore, the device 100 for diagnosing the battery 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 device 100 for diagnosing the battery, as well as data generated during the execution of operations or functions, etc. The storage unit 130 is not particularly limited in type, as long as it is a known information storage device capable of recording, erasing, updating, and retrieving data. For example, the information storage device may include RAM (Random Access Memory), flash memory, ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, etc. Furthermore, the storage unit 130 may store program code defining the processes that can be executed by the curve acquisition unit 110 and the control unit 120.

[0089] If the battery condition is diagnosed as abnormal, the control unit 120 can be configured to output a notification signal to issue a warning of a sudden drop.

[0090] Specifically, in batteries diagnosed as being in an abnormal state, the rate of decrease in CC capacity is greater than the rate of increase in CV capacity. In other words, batteries diagnosed as being in an abnormal state may be in a state where their lifespan is rapidly degrading. Therefore, batteries diagnosed as being in an abnormal state have a very high probability of experiencing a sudden drop in capacity at an unexpected time.

[0091] If a battery is installed and used in a device such as a bicycle, motorcycle, vehicle, drone, or ESS, the device may shut down in the event of a sudden drop in the battery. For example, if a sudden drop occurs in the battery, the vehicle or other transportation equipment may shut down, potentially resulting in injury or death. Similarly, if a device such as a drone shuts down, property damage such as damage to the equipment and / or loss may occur. Furthermore, damage to the equipment itself can also lead to injury or death.

[0092] Therefore, the advantage of the battery diagnostic device 100 is that it prevents accidents caused by sudden drops in the battery by determining the likelihood of a sudden drop in capacity based on the CC capacity and CV capacity, which can be easily obtained from the charging curve CP. Furthermore, the battery diagnostic device 100 can provide a warning for batteries with a high likelihood of sudden drops by outputting a notification signal about the diagnostic results to the outside.

[0093] Figures 3 to 5 A diagram illustrating the diagnostic results for the first through third batteries.

[0094] Specifically, the first battery is designed to degrade slowly with increasing cycle life, the second battery is designed to degrade at a normal level with increasing cycle life, and the third battery is designed to degrade rapidly with increasing cycle life.

[0095] exist Figure 3 In one embodiment, the first curve P1 is a curve representing the corrected rate of change of the first battery per cycle, the second curve P2 is a curve representing the corrected rate of change of the second battery per cycle, and the third curve P3 is a curve representing the corrected rate of change of the third battery per cycle.

[0096] The control unit 120 can diagnose the state of the batteries by comparing the corrected rate of change of the first to third batteries in each cycle with a preset threshold (th). The first battery can be diagnosed as being in a normal state throughout the entire cycle, the second battery can be diagnosed as being in an abnormal state for the first time at the 350th cycle, and the third battery can be diagnosed as being in an abnormal state for the first time at the 200th cycle.

[0097] exist Figure 4 In one embodiment, the fourth curve P4 is a curve showing the SOH (state of health) of the first battery for each cycle, the fifth curve P5 is a curve showing the SOH of the second battery for each cycle, and the sixth curve P6 is a curve showing the SOH of the third battery for each cycle.

[0098] The control unit 120 can diagnose the state of the batteries by comparing the state of harm (SOH) of the first to third batteries in each cycle with a preset first threshold (th1). Here, the first threshold (th1) can be preset as a reference SOH value, which can distinguish the battery state as a normal state or an abnormal state. The first battery can be diagnosed as being in a normal state throughout the entire cycle, the second battery can be diagnosed as being in an abnormal state for the first time at the 400th cycle, and the third battery can be diagnosed as being in an abnormal state for the first time at the 300th cycle.

[0099] Furthermore, the control unit 120 can diagnose the state of the batteries by comparing the SOH change rate of the first to third batteries in each cycle with a preset second threshold (th2). Here, the second threshold (th2) can be preset as a reference SOH change rate that can distinguish the battery state into a normal state or an abnormal state. The first battery can be diagnosed as being in a normal state throughout the entire cycle, the second battery can be diagnosed as being in an abnormal state for the first time at cycle 370, and the third battery can be diagnosed as being in an abnormal state for the first time at cycle 250.

[0100] refer to Figure 5 When diagnosing the battery state based on the corrected change rate, SOH, and the corrected change rate among the SOH change rates, it can be confirmed that the cycle first diagnosed as abnormal is the earliest. Therefore, according to embodiments of this disclosure, there is the advantage of early detection of batteries with a high probability of sudden drops.

[0101] The control unit 120 can be configured to set battery usage conditions based on diagnostic results. Here, usage conditions refer to the conditions used to operate the battery and may include charging current, permissible temperature, available voltage, available state of charge (SOC), etc.

[0102] Specifically, if the correction rate of change is less than a threshold, the control unit 120 can be configured to change the preset charging current for the battery. Since the correction rate of change is a value related to the decrease in CC capacity and the increase in CV capacity when the battery is charged, charging-related usage conditions should be controlled to reduce the possibility of sudden battery degradation. In particular, among charging-related usage conditions, changing usage conditions directly related to CC capacity and CV capacity is an appropriate measure for the battery. Therefore, if the battery state is diagnosed as abnormal, the control unit 120 can change the preset charging current for the battery.

[0103] Preferably, the control unit 120 can reduce the preset charging current for the battery. If the charging current is reduced, the overvoltage is reduced, which increases the time it takes for the battery voltage to reach the threshold voltage (Vth). In other words, if the charging current is reduced, the CC capacity can be increased more than before due to the reduction in overvoltage.

[0104] To reduce the preset charging current, the control unit 120 can change the upper limit of the charging current based on a correction rate of change. For example, the control unit 120 can be configured to change the upper limit of the charging current to a value obtained by multiplying the correction rate of change by the upper limit of the charging current. That is, since the correction rate of change is a value less than a threshold (e.g., 1), the value obtained by multiplying the preset upper limit of the charging current by the correction rate of change can be less than the preset upper limit of the charging current.

[0105] Furthermore, the correction rate of change is a factor reflecting the battery's capacity change behavior. Therefore, by lowering the preset upper limit of the charging current using the correction rate of change, the control unit 120 can change the upper limit of the charging current set for the battery to correspond to the battery's capacity change behavior.

[0106] In other words, the device 100 for diagnosing batteries can quickly diagnose the state of the battery based on the correction rate of change, and significantly reduce the possibility of a sudden drop in the battery's charging current by changing the upper limit of the charging current from the diagnosis time point. Therefore, the device 100 for diagnosing batteries can increase the expected lifespan of the battery.

[0107] The battery diagnostic apparatus 100 according to this disclosure can be applied to a battery management system (BMS). In other words, a BMS according to this disclosure may include the battery diagnostic apparatus 100 described above. In this configuration, at least some of the components of the battery diagnostic apparatus 100 can be implemented by supplementing or adding the functionality of components included in a conventional BMS. For example, the curve acquisition unit 110, control unit 120, and storage unit 130 of the battery diagnostic apparatus 100 can be implemented as components of a BMS.

[0108] Furthermore, the battery diagnostic device 100 according to this disclosure can be disposed in the battery pack. That is, the battery pack according to this disclosure may include the aforementioned battery diagnostic device 100 and at least one battery cell. In addition, the battery pack may also include electrical components (relays, fuses, etc.) and a housing.

[0109] Figure 6 This is a schematic diagram illustrating a battery pack 10 according to another embodiment of the present disclosure.

[0110] The positive electrode terminal of battery 11 can be connected to the positive electrode terminal P+ of battery pack 10, and the negative electrode terminal of battery 11 can be connected to the negative electrode terminal P- of battery pack 10.

[0111] The measuring unit 12 can be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measuring unit 12 can be connected to the positive terminal of the battery 11 via the first sensing line SL1 and to the negative terminal of the battery 11 via the second sensing line SL2. The measuring unit 12 can measure the voltage of the battery 11 based on the voltage measured at each sensing line in the first sensing line SL1 and the second sensing line SL2.

[0112] Furthermore, the measurement unit 12 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 current and discharging current of the battery 11. The measurement unit 12 can calculate the amount of charge by measuring the charging current of the battery 11 via the third sensing line SL3. Furthermore, the measurement unit 12 can calculate the amount of discharge by measuring the discharging current of the battery 11 via the third sensing line SL3.

[0113] For example, the curve acquisition unit 110 can receive battery information about the voltage and current of the battery 11 from the measurement unit 12. Then, the curve acquisition unit 110 can generate a charging curve CP based on the battery information.

[0114] As another example, curve acquisition unit 110 can receive the charging curve CP from measurement unit 12.

[0115] An external device can be connected to the positive terminal P+ and the negative terminal P- of the battery pack 10. For example, the external device can be a charging device or a load. In addition, the positive terminal of the battery 11, the positive terminal P+ of the battery pack 10, the external device, the negative terminal P- of the battery pack 10, and the negative terminal of the battery 11 can be electrically connected.

[0116] Figure 7 This is a schematic diagram illustrating a vehicle 700 according to yet another embodiment of the present disclosure.

[0117] refer to Figure 7 The battery pack 710 according to embodiments of this disclosure can be included in a vehicle 700 such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack 710 can drive the vehicle 700 by supplying power to a motor via an inverter included in the vehicle 700. Here, the battery pack 710 may include a device 100 for diagnosing the battery. That is, the vehicle 700 may include a device 100 for diagnosing the battery. In this case, the device 100 for diagnosing the battery may be an on-board device included in the vehicle 700.

[0118] Figure 8 The diagram is intended to schematically illustrate a method for diagnosing a battery according to yet another embodiment of the present disclosure.

[0119] refer to Figure 8 The method for diagnosing a battery may include a curve acquisition step (S100), a capacity calculation step (S200), a capacity change rate calculation step (S300), a diagnosis step (S400), and a usage condition setting step (S500).

[0120] Preferably, each step of the method for diagnosing the battery can be performed by the device 100 for diagnosing the battery. Hereinafter, for ease of explanation, content repeated above will be omitted or briefly described.

[0121] The curve acquisition step (S100) is the step of acquiring the charging curve CP, which represents the correspondence between the battery voltage and current measured during the charging process, and the curve acquisition step (S100) can be executed by the curve acquisition unit 110.

[0122] For example, the curve acquisition unit 110 can directly receive the charging curve CP from the outside. That is, the curve acquisition unit 110 can obtain the charging curve CP by receiving the charging curve CP through a wired and / or wireless connection to the outside.

[0123] As another example, the curve acquisition unit 110 can receive battery information regarding the battery's voltage and current. Furthermore, the curve acquisition unit 110 can generate a charging curve CP based on the received battery information. In other words, the curve acquisition unit 110 can obtain the charging curve CP by directly generating it based on the battery information.

[0124] The capacity calculation step (S200) is a step of calculating the first CC capacity and the first CV capacity based on the charging curve CP, and can be executed by the control unit 120.

[0125] For example, the control unit 120 can use the current counting method (ampere counting method or coulomb counting method) to calculate the first CC capacity and the first CV capacity of the battery based on the charging curve CP.

[0126] The capacity change rate calculation step (S300) is a step of calculating the capacity change rate of the first CC capacity and the first CV capacity based on the pre-stored second CC capacity and second CV capacity, and can be executed by the control unit 120.

[0127] For example, the control unit 120 can calculate the CC capacity difference between the first CC capacity and the second CC capacity, calculate the CV capacity difference between the first CV capacity and the second CV capacity, and calculate the capacity change rate by calculating the ratio of the CC capacity difference to the CV capacity difference.

[0128] The diagnostic step (S400) is a step to diagnose the state of the battery based on the calculated capacity change rate and the preset correction coefficient, and can be executed by the control unit 120.

[0129] For example, the control unit 120 can calculate the correction rate of change by multiplying the rate of capacity change by a correction coefficient. Furthermore, if the correction rate of change is greater than or equal to a threshold (th), the control unit 120 can diagnose the battery state as normal. Conversely, if the correction rate of change is less than the threshold (th), the control unit 120 can diagnose the battery state as abnormal.

[0130] The usage condition setting step (S500) is a step of setting the battery usage conditions based on the diagnostic results, and can be executed by the control unit 120.

[0131] For example, the control unit 120 can be configured to change the upper limit of the charging current to a value obtained by multiplying the correction rate of change by the upper limit of the charging current.

[0132] The embodiments of this disclosure described above can be implemented not only by apparatus and methods, but also by a program that implements functions corresponding to the configuration of the embodiments of this disclosure, or by a recording medium containing such a program. Based on the description of the above embodiments, those skilled in the art can readily implement the program or recording medium.

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

[0134] Furthermore, without departing from the technical aspects of this disclosure, those skilled in the art can make various substitutions, modifications, and variations to the disclosure described above, and this disclosure is not limited to the above embodiments and drawings, and each embodiment can be selectively combined in part or in whole to allow for various modifications.

[0135] (See attached image labels)

[0136] 10: Battery Pack

[0137] 11: Battery

[0138] 12: Measurement Unit

[0139] 100: Devices for diagnosing batteries

[0140] 110: Curve Acquisition Unit

[0141] 120: Control Unit

[0142] 130: Storage unit

[0143] 400: Vehicles

[0144] 410: Battery Pack

Claims

1. A device for diagnosing a battery, comprising: A curve acquisition unit is configured to acquire a charging curve, which represents the relationship between the voltage and current of the battery measured during the charging process. as well as The control unit is configured to calculate a first CC capacity and a first CV capacity based on the charging curve, calculate the capacity change rate of the first CC capacity and the first CV capacity based on a pre-stored second CC capacity and a second CV capacity, diagnose the state of the battery based on the calculated capacity change rate and a preset correction coefficient, and set the usage conditions of the battery based on the diagnosis results.

2. The device for diagnosing batteries according to claim 1, in, The control unit is configured to calculate the CC capacity difference between the first CC capacity and the second CC capacity, calculate the CV capacity difference between the first CV capacity and the second CV capacity, and calculate the capacity change rate by calculating the ratio of the CC capacity difference to the CV capacity difference.

3. The device for diagnosing batteries according to claim 2, in, The control unit is configured to: calculate the decrease in the first CC capacity relative to the second CC capacity as the CC capacity difference; and calculate the increase in the first CV capacity relative to the second CV capacity as the CV capacity difference.

4. The device for diagnosing batteries according to claim 1, in, The control unit is configured to calculate a corrected rate of change by multiplying the rate of change of capacity by the correction coefficient, compare the corrected rate of change with a preset threshold, and diagnose the state of the battery based on the comparison result.

5. The device for diagnosing batteries according to claim 4, in, The control unit is configured to diagnose the battery's state as normal when the correction rate of change is greater than or equal to the threshold, and The control unit is configured to diagnose the state of the battery as an abnormal state when the correction rate of change is less than the threshold.

6. The apparatus for diagnosing batteries according to claim 5, in, The control unit is configured to output a notification signal to issue a warning of a sudden drop when the state of the battery is diagnosed as the abnormal state.

7. The apparatus for diagnosing batteries according to claim 4, in, The control unit is configured to change the preset charging current for the battery when the correction rate of change is less than the threshold.

8. The apparatus for diagnosing batteries according to claim 7, in, The control unit is configured to change the upper limit of the charging current to a value obtained by multiplying the correction rate of change by the upper limit of the charging current.

9. The apparatus for diagnosing batteries according to claim 1, in, The correction coefficient is preset based on the change in the CC capacity and the change in the CV capacity of the battery during a preset reference number of cycles.

10. The apparatus for diagnosing batteries according to claim 9, in, The correction factor is preset as the ratio of the representative change in CV capacity to the representative change in CC capacity during the preset reference number of cycles.

11. A battery pack comprising the means for diagnosing the battery according to any one of claims 1 to 10.

12. A vehicle comprising a device for diagnosing a battery according to any one of claims 1 to 10.

13. A method for diagnosing a battery, comprising: The curve acquisition step obtains a charging curve, which represents the relationship between the battery voltage and current measured during the charging process. The capacity calculation step calculates the first CC capacity and the first CV capacity based on the charging curve. The capacity change rate calculation step calculates the capacity change rate of the first CC capacity and the first CV capacity based on the pre-stored second CC capacity and second CV capacity. The diagnostic step diagnoses the state of the battery based on the calculated capacity change rate and a preset correction coefficient. as well as The usage condition setting step sets the usage conditions of the battery based on the diagnostic results.

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