Battery diagnosis device and method, battery pack, and computer-readable recording medium

Abstract

A battery diagnosis device according to an embodiment of the present application includes a measurement unit configured to measure an open-circuit voltage of a battery after completion of charging of the battery, and measure an electrical resistance of the battery when the battery is discharged for a predetermined time after the completion of the charging of the battery, and a control unit configured to receive voltage information on the open-circuit voltage and resistance information on the electrical resistance from the measurement unit, calculate a voltage deviation between the open-circuit voltage and a reference voltage set in advance for the battery, calculate an electrical resistance deviation between the electrical resistance and a reference electrical resistance set in advance for the battery, and diagnose whether or not deterioration of the battery is accelerated based on the voltage deviation and the electrical resistance deviation.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2021-0039998, filed in Korea on March 26, 2021, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a battery diagnostic device and method, and more specifically, to a battery diagnostic device and method capable of diagnosing the degradation state of a battery. Background Technology

[0003] Recently, demand for portable electronic products such as laptops, cameras, and mobile phones has surged, and electric vehicles, energy storage batteries, robots, and satellites have truly taken off. As a result, high-performance batteries that can be repeatedly charged and discharged are under active research.

[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 batteries, extremely low self-discharge rate, and high energy density.

[0005] To diagnose the degradation state of a battery, techniques have traditionally been used to analyze changes in the behavior of peaks (characteristic points) included in the differential profile.

[0006] Figure 1 It is a diagram schematically showing the differential curve representing the relationship between battery voltage and differential capacity.

[0007] For example, refer to Figure 1 Traditionally, it is possible to diagnose whether battery degradation is accelerated by generating the differential curve of the battery and examining the peak value Ec(4) included in the differential curve.

[0008] However, to diagnose whether battery degradation is accelerating in a conventional way, it is necessary to generate a differential curve. The problem with generating a differential curve is that it requires a charge-discharge process involving either a fully discharged battery being fully charged or a fully charged battery being fully discharged. Furthermore, calculating the differential capacity requires processing the battery's voltage and capacity data obtained during the charge-discharge process. Summary of the Invention

[0009] Technical issues

[0010] This disclosure aims to solve the problems in the related technology. Therefore, the purpose of this disclosure is to provide a battery diagnostic device and method that can quickly and conveniently diagnose whether the battery degradation is accelerated based on the battery voltage and resistance each time it is charged.

[0011] These and other objects and advantages of this disclosure will become clear from the following detailed description and will become even clearer through 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 shown in the appended claims and combinations thereof.

[0012] Technical solution

[0013] A battery diagnostic apparatus according to one aspect of this disclosure may include: a measurement unit configured to measure the open voltage (OCV) of the battery after charging is completed, and to measure the resistance of the battery when the battery has discharged for a predetermined time after charging is completed; and a control unit configured to receive voltage information of the OCV and resistance information of the resistance from the measurement unit, calculate the voltage deviation between the OCV and a preset standard voltage for the battery, calculate the resistance deviation between the resistance and a preset standard resistance for the battery, and diagnose whether the degradation of the battery is accelerated based on the voltage deviation and the resistance deviation.

[0014] The battery can be configured to stop charging when the SOC reaches a preset upper limit SOC.

[0015] The control unit can be configured to calculate a resistance-voltage ratio, which is the ratio of the resistance deviation to the voltage deviation, whenever the charging of the battery ends, and to diagnose whether the degradation of the battery is accelerated based on a plurality of calculated resistance-voltage ratios.

[0016] The control unit can be configured to determine an increase / decrease pattern among the plurality of resistance-voltage ratios, and diagnose whether the degradation of the battery is accelerated based on the determined increase / decrease pattern.

[0017] The control unit can be configured to diagnose accelerated battery degradation when the increase / decrease mode is determined to be an increase mode.

[0018] The control unit can be configured to reduce the preset upper limit SOC when the increase / decrease mode is determined to be an increase mode.

[0019] The control unit can be configured to compare the rate of change of the plurality of resistor-voltage ratios with a preset standard rate of change, and determine the increase / decrease mode based on the comparison results.

[0020] The control unit can be configured to generate a fluctuation curve representing the increase or decrease of the plurality of resistance-voltage ratios, and to determine the increase / decrease mode as the increase mode when the slope of the fluctuation curve is greater than or equal to the standard rate of change.

[0021] The control unit can be configured to determine that the battery contains high nickel-based positive electrode material when the increase / decrease mode is determined to be an increase mode.

[0022] According to another aspect of this disclosure, a battery pack may include a battery diagnostic device according to another aspect of this disclosure.

[0023] A battery diagnostic method according to another aspect of this disclosure may include: a voltage measurement step, wherein the voltage measurement step measures the open voltage (OCV) of the battery after the battery charging is completed; a resistance measurement step, wherein the resistance measurement step measures the resistance of the battery after the battery discharges for a predetermined time after the charging is completed; a voltage deviation and resistance deviation calculation step, wherein the voltage deviation and resistance deviation calculation step calculates the voltage deviation between the OCV and a preset standard voltage for the battery, and calculates the resistance deviation between the resistance and a preset standard resistance for the battery; and a diagnostic step, wherein the diagnostic step diagnoses whether the battery degradation is accelerated based on the voltage deviation and the resistance deviation.

[0024] According to another aspect of the present disclosure, a computer-readable recording medium may store a computer-executable program that, when executed by a processor, performs a battery diagnostic method according to another aspect of the present disclosure.

[0025] Technical effect

[0026] According to one aspect of this disclosure, whenever the battery's State of Charge (SOC) reaches its upper limit, the acceleration of battery degradation can be diagnosed based on the battery's voltage and resistance deviations. Therefore, a charge-discharge process (e.g., a full charge and full discharge process) is unnecessary for determining whether degradation is accelerated, and the advantage is that accelerated degradation can be quickly diagnosed through relatively simple calculations.

[0027] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand other unmentioned effects from the description of the claims. 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 should not be construed as being limited to the accompanying drawings.

[0029] Figure 1 It is a diagram schematically showing the differential curve representing the relationship between battery voltage and differential capacity.

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

[0031] Figure 3 This is a schematic diagram illustrating the voltage deviation of a battery calculated by a battery diagnostic device according to an embodiment of the present disclosure.

[0032] Figure 4 This is a schematic diagram illustrating the resistance deviation of a battery calculated by a battery diagnostic device according to an embodiment of the present disclosure.

[0033] Figure 5 This is a schematic diagram showing the resistance-voltage ratio of the first and second batteries calculated by a battery diagnostic device according to an embodiment of the present disclosure.

[0034] Figure 6 This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of this disclosure.

[0035] Figure 7 This is a schematic diagram illustrating a battery diagnostic method according to yet another embodiment of the present disclosure. Detailed Implementation

[0036] It should be understood that the terms used in the specification and the appended claims should not be construed as limited to their general or dictionary meanings, but rather should be interpreted in accordance with the meanings and concepts consistent with the technical aspects of this disclosure, based on the principle that the inventors are allowed to define the terms appropriately to obtain the best interpretation.

[0037] Therefore, the description presented herein is merely a preferred example for illustrative purposes only and is not intended to limit the scope of the disclosure. It should be understood that other equivalents and modifications may be made without departing from the scope of this disclosure.

[0038] Furthermore, in describing this disclosure, detailed descriptions of relevant known elements or functions are omitted here where it is believed that such detailed descriptions would obscure the key subject matter of the invention.

[0039] Ordinal terms such as “first” and “second” can be used to distinguish one element from another among various different elements, but are not intended to be restrictive through these terms.

[0040] Throughout this specification, when a section is referred to as “comprising” or “including” any element, unless otherwise specifically stated, it means that the section may include other elements rather than exclude other elements.

[0041] 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" through another element.

[0042] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0043] Figure 2 This is a schematic diagram illustrating a battery diagnostic device 100 according to an embodiment of the present disclosure.

[0044] Reference Figure 2 The battery diagnostic device 100 may include a measurement unit 110 and a control unit 120.

[0045] The measurement unit 110 can be configured to measure the battery's OCV (open-circuit voltage) after the battery has finished charging.

[0046] Here, a battery refers to a single, physically separable cell with negative and positive terminals. For example, a lithium-ion battery or a lithium polymer battery can be considered a battery. Furthermore, a battery can refer to a battery module consisting of multiple cells connected in series and / or parallel. In the following text, for ease of explanation, a battery will be described as a single, independent cell.

[0047] Specifically, charging can be stopped when the battery's SOC (State of Charge) reaches a preset upper limit. After charging is complete, the measurement unit 110 can measure the battery's OCV (Open Circuit Voltage) after a preset rest period.

[0048] For example, after the battery has finished charging, the measurement unit 110 can measure the battery's OCV after a ten-minute rest period.

[0049] The measuring unit 110 can be configured to measure the resistance of the battery after the battery has finished charging and after the battery has been discharged for a predetermined time.

[0050] Preferably, after the measuring unit 110 measures the battery's OCV, the battery can be discharged for a predetermined time. The measuring unit 110 can measure the battery's resistance based on the voltage drop value of the battery during discharge and the amount of discharge output from the battery.

[0051] For example, after measuring the battery's OCV, the battery can be discharged for a predetermined time (e.g., one minute). The measurement unit 110 can measure the battery's voltage drop over one minute. Additionally, the measurement unit 110 can measure the discharge amount by accumulating the discharge current output from the battery over one minute. Furthermore, the measurement unit 110 can measure the battery's resistance based on the voltage drop and the discharge amount.

[0052] Specifically, the measuring unit 110 measures the battery resistance by taking into account the battery's ohmic resistance, charge transfer resistance, and diffusion resistance after a predetermined time has elapsed after measuring the battery's OCV.

[0053] The control unit 120 can be configured to receive voltage information of OCV and resistance information of resistance from the measurement unit 110.

[0054] For example, the measurement unit 110 and the control unit 120 can be connected to each other to communicate. The measurement unit 110 can output voltage information of the battery's OCV and resistance information, and the control unit 120 can receive the voltage information and resistance information output from the measurement unit 110.

[0055] The control unit 120 can be configured to calculate the voltage deviation between the OCV and a preset standard voltage for the battery.

[0056] Preferably, the standard voltage can be the OCV measured when the battery is in a BOL (Burning Online) state. For example, the BOL state can mean that the battery is in cycle 0. Furthermore, the control unit 120 can calculate the battery voltage deviation by calculating the difference between the standard voltage and the OCV measured by the measuring unit 110.

[0057] For example, voltage deviation can be calculated as the difference between the standard voltage and the measured OCV, or the ratio of the standard voltage to the measured OCV.

[0058] In the following text, for ease of explanation, voltage deviation will be described as the voltage difference between the standard voltage and the measured OCV. That is, voltage deviation can be calculated using the formula "OCV - Standard Voltage".

[0059] Figure 3 This is a schematic diagram showing the voltage deviation of the battery calculated by the battery diagnostic device 100 according to an embodiment of the present disclosure.

[0060] Specifically, Figure 3 This is a graph showing the calculated battery voltage deviation for each cycle. That is, in each cycle, the battery is charged until the State of Charge (SOC) reaches its upper limit, and after charging is complete, the OCV (Optical Voltage Value) can be measured by the measurement unit 110. Furthermore, the control unit 120 can calculate the battery voltage deviation for each cycle based on a standard voltage and the OCV measured in each cycle.

[0061] For example, the OCV in cycle 0, after the battery charging is complete, can be set as the standard voltage. Then, the measurement unit 110 can measure the battery's OCV in each cycle, and the control unit 120 can calculate the battery's voltage deviation using the formula "OCV - Standard Voltage".

[0062] The control unit 120 can be configured to calculate the resistance deviation between the resistor and a standard resistor preset for the battery.

[0063] Preferably, the standard resistor can be the resistance measured when the battery is in a BOL state. That is, the control unit 120 can calculate the battery resistance deviation based on the difference between the standard resistor and the resistance measured by the measuring unit 110.

[0064] For example, resistance deviation can be calculated as the difference between the standard resistance and the measured resistance, or the ratio of the standard resistance to the measured resistance.

[0065] In the following text, for ease of explanation, resistance deviation will be described as the ratio of the resistance to the standard resistance. That is, the resistance deviation can be calculated using the formula "(resistance ÷ standard resistance) × 100".

[0066] Figure 4 This is a schematic diagram showing the resistance deviation of the battery calculated by the battery diagnostic device 100 according to an embodiment of the present disclosure.

[0067] Specifically, Figure 4 This is a graph showing the battery resistance deviation calculated in each cycle. That is, in each cycle, the battery is charged until the State of Charge (SOC) reaches its upper limit, and after charging is complete, the resistance can be measured by the measurement unit 110. Furthermore, the control unit 120 can calculate the battery resistance deviation in each cycle based on a standard resistance and the resistance measured in each cycle.

[0068] The control unit 120 can be configured to diagnose whether battery degradation is accelerating based on voltage and resistance deviations.

[0069] Here, accelerated battery degradation means that battery degradation does not proceed linearly but accelerates as cycling progresses. In other words, the control unit 120 can non-destructively diagnose whether battery degradation is accelerating by using calculated voltage deviations and calculated resistance deviations.

[0070] For example, refer to Figure 1 Traditionally, the acceleration of battery degradation can be diagnosed by generating a differential curve of the battery and examining the behavior of the peaks included in the curve. In this conventional approach, generating the differential curve requires either fully charging a fully discharged battery or fully discharging a fully charged battery. Furthermore, calculating the differential capacity requires processing the battery's voltage and capacity data obtained during the charge-discharge process.

[0071] On the other hand, the battery diagnostic device 100 according to the embodiments of the present disclosure can diagnose whether the battery degradation is accelerated based on the battery voltage deviation and resistance deviation whenever the battery's SOC reaches the upper limit SOC, without having to fully discharge the battery.

[0072] Therefore, according to the battery diagnostic device 100, a charging and discharging process (e.g., a full charge and a full discharge process) is not required, as this process is unnecessary for determining whether degradation is accelerated. The advantage is that whether degradation is accelerated can be quickly diagnosed through relatively simple calculations.

[0073] Additionally, the control unit 120 disposed in the battery diagnostic device 100 may optionally include processors, application-specific integrated circuits (ASICs), another chipset, logic circuits, registers, communication modems, and data processing devices known in the art to execute the various control logics performed in this disclosure. 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 a memory and executed by the control unit 120. The memory may be disposed within or outside the control unit 120 and may be connected to the control unit 120 by known means.

[0074] In addition, the battery diagnostic device 100 may also include a storage unit 130. The storage unit 130 may store data or programs required for the operation and function of the various components of the battery diagnostic device 100, as well as data generated during the execution of operations or functions. There are no particular limitations on the type of storage unit 130; it can be any known information storage device capable of recording, erasing, updating, and retrieving data. As an example, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. Furthermore, the storage unit 130 may store program code defining processes that can be executed by the control unit 120.

[0075] For example, storage unit 130 can store battery voltage and resistance information. Furthermore, storage unit 130 can store the voltage and resistance deviations for each battery cycle.

[0076] The following text will describe in detail how the control unit 120 diagnoses whether battery degradation is accelerating.

[0077] The control unit 120 can be configured to calculate the resistance-voltage ratio as the ratio of resistance deviation to voltage deviation whenever the battery charging ends.

[0078] Specifically, the resistance-voltage ratio can mean the ratio of the resistance deviation to the voltage deviation calculated in the same cycle. For example, the resistance-voltage ratio can be calculated using the formula "(resistance deviation - 100) ÷ |voltage deviation|". Here, |voltage deviation| means the absolute value of the voltage deviation.

[0079] Figure 5 This is a schematic diagram showing the resistance-voltage ratio of the first battery B1 and the second battery B2 calculated by the battery diagnostic device 100 according to an embodiment of the present disclosure.

[0080] Here, the first battery B1 is an NCM622 battery with a nickel content of 60% in the positive electrode material, and the second battery B2 is an NCMA battery with a nickel content of 83% in the positive electrode material.

[0081] For example, in Figure 5 In this implementation, for the first battery B1, the resistance-voltage ratio is measured from cycle 100 to cycle 670, and for the second battery B2, the resistance-voltage ratio is measured from cycle 0 to cycle 600.

[0082] Furthermore, in each cycle, the first battery B1 and the second battery B2 are charged to the same upper limit SOC at the same C rate. That is to say, it should be noted that, apart from the nickel content in the positive electrode materials of the first battery B1 and the second battery B2, conditions such as charging and discharging temperatures, charging C rate, discharging C rate, and upper limit SOC are all the same.

[0083] The control unit 120 can be configured to diagnose whether battery degradation is accelerating based on multiple calculated resistance-voltage ratios.

[0084] Specifically, the control unit 120 can be configured to determine an increase / decrease pattern among multiple resistor-voltage ratios.

[0085] Here, the increase / decrease mode can include an increase mode, a decrease mode, and a hold mode. An increase mode means that the resistance-voltage ratio increases as the cycle progresses, a decrease mode means that the resistance-voltage ratio decreases as the cycle progresses, and a hold mode means that the resistance-voltage ratio remains constant within a predetermined range.

[0086] The control unit 120 can be configured to diagnose whether battery degradation is accelerated based on a determined increase / decrease pattern.

[0087] Specifically, the control unit 120 can be configured to diagnose accelerated battery degradation when the increase / decrease mode is determined to be the increase mode.

[0088] For example, in Figure 5In this embodiment, the resistance-voltage ratio of the first battery B1 increases as cycling progresses, while the resistance-voltage ratio of the second battery B2 remains constant within a predetermined range even as cycling progresses. Therefore, the control unit 120 can determine the increase / decrease pattern of the resistance-voltage ratio of the first battery B1 as an increasing mode and the increase / decrease pattern of the resistance-voltage ratio of the second battery B2 as a maintaining mode. Furthermore, the control unit 120 can diagnose accelerated degradation of the first battery B1, where the increase / decrease pattern is determined to be in the increasing mode.

[0089] More specifically, the control unit 120 can be configured to compare the rate of change of multiple resistor-voltage ratios with a preset standard rate of change, and determine an increase / decrease mode based on the comparison results.

[0090] Specifically, when the slope of the fluctuation curve is greater than or equal to the standard rate of change, the control unit 120 can be configured to determine the increase / decrease mode as the increase mode.

[0091] Here, the standard rate of change can be a standard rate of change used to determine the increase / decrease mode as an increase mode. For example, if the rate of change of the resistance-voltage ratio is greater than or equal to the standard rate of change, the control unit 120 can determine the increase / decrease mode of the battery's resistance-voltage ratio as an increase mode.

[0092] Preferably, in order to compare the standard rate of change with the rate of change of the resistance-voltage ratio, the control unit 120 can be configured to generate multiple fluctuation curves of the resistance-voltage ratio.

[0093] For example, the control unit 120 can generate a fluctuation curve by calculating the median between two consecutive cycles of the resistance-voltage ratio and connecting multiple calculated medians. However, it should be noted that the fluctuation curve can simply represent the increase or decrease of multiple resistance-voltage ratios, and is not limited to generating it using the median value as described in the above embodiment.

[0094] exist Figure 5 In this implementation, line segment C1 can be used to represent the fluctuation curve generated for the first battery B1, and line segment C2 can be used to represent the fluctuation curve generated for the second battery B2.

[0095] For example, in the fluctuation curve C1 for the first battery B1, the rate of change of the resistance-voltage ratio around cycle 300 can be greater than or equal to the standard rate of change. Therefore, the control unit 120 can determine the increase / decrease pattern of the resistance-voltage ratio of the first battery B1 as an increasing pattern and diagnose that the degradation of the first battery B1 accelerates from approximately cycle 300. In this case, the control unit 120 can prevent the degradation of the first battery B1 from accelerating more and more after approximately cycle 300 by reducing the preset upper limit SOC for the first battery B1.

[0096] Conversely, in the fluctuation curve C2 for the second battery B2, the rate of change of the resistance-voltage ratio can be less than the standard rate of change during the period from cycle 0 to cycle 600. Therefore, the control unit 120 can diagnose that the degradation of the second battery B2 has not accelerated.

[0097] The battery diagnostic apparatus 100 according to embodiments of this disclosure can quickly diagnose whether battery degradation is accelerated based on the voltage and resistance measured each time the battery charging ends. In other words, since the battery diagnostic apparatus 100 can diagnose whether battery degradation is accelerated as soon as the battery's SOC reaches the upper limit and charging ends, it has a practical advantage: compared to conventional methods for determining whether battery degradation is accelerated, it can diagnose whether battery degradation is accelerated more quickly.

[0098] In addition, the control unit 120 can be configured to determine that the battery contains high-nickel-based cathode material when the increase / decrease mode is determined to be an increase mode.

[0099] In other words, the control unit 120 can classify battery types based on multiple increasing / decreasing patterns of resistance-voltage ratios. Specifically, the control unit 120 can classify batteries as low-nickel batteries (batteries with a nickel content of less than 80% in the positive electrode material) or high-nickel batteries (batteries with a nickel content of greater than or equal to 80% in the positive electrode material).

[0100] For example, in the case of batteries where the composition of the positive electrode material is uncertain, a problem with the prior art is that the composition of the positive electrode material must be inspected by disassembling the battery. However, according to embodiments of the present disclosure, the composition of the positive electrode material of the battery can be easily inspected based on multiple increasing / decreasing patterns of resistance-voltage ratios.

[0101] exist Figure 5 In the implementation, it can be observed that the first battery B1, being a high-nickel-based battery, clearly exhibits an increasing resistance-voltage ratio increase / decrease pattern, while the second battery B2, being a low-nickel-based battery, does not exhibit an increasing resistance-voltage ratio increase / decrease pattern. Since this can be attributed to the difference in nickel content contained in the positive electrode materials of the first battery B1 and the second battery B2, the battery diagnostic device 100 has the advantage of distinguishing the type of battery based on the composition of the positive electrode material during the diagnosis of whether battery degradation is accelerating.

[0102] Additionally, the control unit 120 can be configured to reduce a preset upper limit SOC when the increase / decrease mode is determined to be an increase mode.

[0103] For example, when the increase / decrease mode is determined to be the increase mode, battery degradation may be accelerated. In this case, to prevent accelerated battery degradation, the control unit 120 can reduce the upper limit SOC set for the battery. That is, by reducing the upper limit SOC, the use of the SOC segment where the battery degrades rapidly is limited, thereby extending the battery's lifespan.

[0104] Therefore, the battery diagnostic device 100 not only diagnoses whether battery degradation is accelerating in a non-destructive manner based on voltage and resistance deviations, but also has the advantage of extending battery life by adjusting the upper limit SOC set for the battery.

[0105] The battery diagnostic device 100 according to this disclosure can be applied to a BMS (Battery Management System). That is, a BMS according to this disclosure may include the battery diagnostic device 100 described above. In this configuration, at least some components of the battery diagnostic device 100 can be implemented by supplementing or adding functionality to a conventional BMS configuration. For example, the voltage measurement unit 110, control unit 120, and storage unit 130 of the battery diagnostic device 100 can be implemented as components of a BMS.

[0106] Figure 6 This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of this disclosure.

[0107] The battery diagnostic device 100 according to this disclosure can be installed in a 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 devices (relays, fuses, etc.) and a housing.

[0108] Reference Figure 6 The charging / discharging device 2 can be connected to the battery B via the positive terminal (P+) and negative terminal (P-) of the battery pack 1. The charging / discharging device 2 can be configured to charge and discharge the battery B. Preferably, the charging / discharging device 2 can charge the battery B until the state of charge (SOC) of the battery B reaches the upper limit SOC. Additionally, when the upper limit SOC is changed by the control unit 120, the charging / discharging device 2 can charge the battery B until the SOC of the battery B reaches the changed upper limit SOC.

[0109] The measurement unit 110 can be connected to the battery B via a first sensing line SL1 and a second sensing line SL2. The measurement unit 110 can measure the positive terminal voltage of the battery B via the first sensing line SL1 and the negative terminal voltage of the battery B via the second sensing line SL2. Furthermore, the measurement unit 110 can measure the voltage of the battery B by calculating the difference between the measured positive terminal voltage and the measured negative terminal voltage.

[0110] Furthermore, the measurement unit 110 can be connected to the current measurement unit A via the third sensing line SL3. The measurement unit 110 can measure the charging current and discharging current of the battery B via the current measurement unit A. For example, the measurement unit 110 can measure the discharging current of the battery B via the current measurement unit A, and measure the discharge amount of the battery B by accumulating the measured discharging current.

[0111] Figure 7 This is a schematic diagram illustrating a battery diagnostic method according to yet another embodiment of the present disclosure.

[0112] Preferably, the battery diagnostic device 100 can perform the various steps of the battery diagnostic method. In the following text, content that is repeated in the previous description will be omitted or briefly described.

[0113] Reference Figure 7 The battery diagnostic method may include a voltage measurement step S100, a resistance measurement step S200, a voltage deviation and resistance deviation calculation step S300, and a diagnostic step S400.

[0114] The voltage measurement step S100 is the step of measuring the battery's OCV after the battery charging is completed, and it can be executed by the measurement unit 110.

[0115] For example, after charging the battery until it reaches the set upper limit of SOC, the measurement unit 110 can measure the battery's OCV.

[0116] The resistance measurement step S200 is a step of measuring the resistance of the battery after the battery charging is completed and the battery has been discharged for a predetermined time. It can be executed by the measurement unit 110.

[0117] For example, after charging the battery until it reaches a set upper limit of SOC, the measurement unit 110 can measure the battery's resistance after discharging the battery for approximately one minute. Specifically, the measurement unit 110 can first measure the battery's OCV, and then measure the battery's resistance based on the voltage drop and discharge amount while the battery is discharging.

[0118] The voltage deviation and resistance deviation calculation step S300 is a step of calculating the voltage deviation between OCV and a preset standard voltage for the battery and calculating the resistance deviation between the resistance and a preset standard resistance for the battery, which can be executed by the control unit 120.

[0119] For example, the control unit 120 can calculate the voltage deviation for each cycle according to the formula "OCV - standard voltage". Furthermore, the control unit 120 can calculate the resistance deviation for each cycle according to the formula "(resistance ÷ standard resistance) × 100".

[0120] Diagnostic step S400 is a step that diagnoses whether battery degradation is accelerating based on voltage and resistance deviations, and can be executed by control unit 120.

[0121] For example, the control unit 120 can calculate the resistance-voltage ratio for each cycle according to the formula "(resistance deviation - 100) ÷ |voltage deviation|" and generate a fluctuation curve to represent the increase or decrease of the calculated resistance-voltage ratio.

[0122] Furthermore, if the slope of the fluctuation curve is greater than or equal to the standard rate of change, the control unit 120 can determine that the increase / decrease mode is the increase mode and diagnose the accelerated degradation of the battery.

[0123] For example, in Figure 5 In this implementation, the slope of the first fluctuation curve C1 at approximately 300 cycles can be greater than or equal to the standard rate of change. That is, since the first fluctuation curve C1 rises rapidly from approximately 300 cycles, the control unit 120 can diagnose that the degradation of the first battery B1 accelerates from approximately 300 cycles.

[0124] Conversely, in the second fluctuation curve C2, the slope can be less than the standard rate of change throughout the entire cycle period (cycle 0 to cycle 600). The control unit 120 can diagnose that the degradation of the second battery B2 is not accelerated throughout the entire cycle period.

[0125] The embodiments of this disclosure described above can be implemented not only by apparatus and methods, but also by a program for implementing functions corresponding to the configuration of the embodiments of this disclosure, or by a recording medium on which the program is recorded. Those skilled in the art can readily implement the program or recording medium based on the above description of the embodiments.

[0126] 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 modifications and adjustments within the scope of this disclosure will become apparent to those skilled in the art from this detailed description.

[0127] Furthermore, those skilled in the art can make many substitutions, adjustments and modifications to the present disclosure without departing from the technical aspects of the present disclosure. The present disclosure is not limited to the above-described embodiments and drawings, and the various embodiments can be selectively combined in part or in whole to achieve various adjustments.

[0128] (See attached image labels)

[0129] 1: Battery pack

[0130] 100: Battery diagnostic device

[0131] 110: Measurement Unit

[0132] 120: Control Unit

[0133] 130: Storage unit

Claims

1. A battery diagnostic device, the battery diagnostic device comprising: A measurement unit configured to measure the open-circuit voltage (OCV) of the battery after charging has ended, and to measure the resistance of the battery after discharging for a predetermined time after charging has ended; as well as A control unit is configured to receive voltage information of the OCV and resistance information of the resistor from the measurement unit, calculate the voltage deviation between the OCV and a preset standard voltage for the battery, calculate the resistance deviation between the resistor and a preset standard resistor for the battery, and diagnose whether the battery degradation is accelerated based on the resistance-voltage ratio, which is the ratio of the resistance deviation to the voltage deviation.

2. The battery diagnostic device according to claim 1, wherein The battery is configured to stop charging when the State of Charge (SOC) reaches a preset upper limit SOC, and The control unit is configured to calculate the resistance-voltage ratio whenever the battery charging ends, and to diagnose whether the battery degradation is accelerated based on the calculated resistance-voltage ratios.

3. The battery diagnostic device according to claim 2, wherein The control unit is configured to determine an increase / decrease pattern among the plurality of resistance-voltage ratios, and to diagnose whether the degradation of the battery is accelerated based on the determined increase / decrease pattern.

4. The battery diagnostic device according to claim 3, wherein, The control unit is configured to diagnose accelerated battery degradation when the increase / decrease mode is determined to be an increase mode.

5. The battery diagnostic device according to claim 3, wherein The control unit is configured to reduce the preset upper limit SOC when the increase / decrease mode is determined to be an increase mode.

6. The battery diagnostic device according to claim 3, wherein The control unit is configured to compare the rate of change of the plurality of resistor-voltage ratios with a preset standard rate of change, and determine the increase / decrease mode based on the comparison results.

7. The battery diagnostic device according to claim 6, in, The control unit is configured to generate a fluctuation curve representing the increase or decrease of the plurality of resistance-voltage ratios, and to determine the increase / decrease mode as an increase mode when the slope of the fluctuation curve is greater than or equal to the standard rate of change.

8. The battery diagnostic device according to claim 3, in, The control unit is configured to determine that the battery contains a high-nickel-based cathode material when the increase / decrease mode is determined to be an increase mode.

9. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 8.

10. A battery diagnostic method, the battery diagnostic method comprising: The voltage measurement step is performed after the battery charging is completed, by measuring the open-circuit voltage OCV of the battery. The resistance measurement step involves measuring the resistance of the battery after the charging of the battery has ended and after the battery has discharged for a predetermined time. The voltage deviation and resistance deviation calculation steps calculate the voltage deviation between the OCV and a preset standard voltage for the battery, and calculate the resistance deviation between the resistance and a preset standard resistance for the battery. as well as The diagnostic step diagnoses whether the battery degradation is accelerated based on the resistance-voltage ratio, which is the ratio of the resistance deviation to the voltage deviation.

11. A computer-readable recording medium storing a computer-executable program that, when executed by a processor, performs the battery diagnostic method according to claim 10.

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