Battery management apparatus and battery management method

Abstract

According to some embodiments, a battery management apparatus includes: an interface configured to obtain an open circuit voltage (OCV) value of each of battery cells of a battery; and a controller configured to calculate an OCV difference value indicating a change amount of the OCV value of each battery cell during a reference period, set a classification reference value on the basis of a distribution of the OCV difference values of the battery cells, and classify states of the battery cells on the basis of the classification reference value.

Description

Battery management device and battery management method

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0194163 filed on December 23, 2024, and includes all contents disclosed in the document of said patent application as part of this specification.

[0003] Technology field

[0004] The embodiments disclosed in this document relate to a battery management device and a battery management method.

[0005] Recently, active research and development on secondary batteries has been underway. Here, secondary batteries are rechargeable batteries and can be interpreted to encompass conventional Ni / Cd and Ni / MH batteries, as well as the more recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries can possess higher energy density compared to conventional Ni / Cd and Ni / MH batteries, and because they can be manufactured in a compact and lightweight form factor, they offer high utility as power sources for mobile devices. Recently, their scope of application has expanded to include power sources for electric vehicles, drawing attention as a next-generation energy storage medium.

[0006] If foreign substances are present inside a battery cell, micro-short circuits may be induced, which can lead to a low-voltage phenomenon where the cell voltage drops abnormally. To identify low-voltage cells, a method of tracking open circuit voltage (OCV) can be utilized, and criteria for diagnosing defects can be established through statistical methods. Near the statistically established diagnostic criteria, uninspection (misidentifying a defective cell as normal) and overinspection (misidentifying a normal cell as defective) may occur, and it may be necessary to address these issues to improve diagnostic reliability.

[0007] One of the objectives of the embodiments disclosed in this document is to provide a battery management device and a battery management method capable of diagnosing cell conditions, such as micro-short circuits, based on the distribution of the amount of change of each cell's OCV value over a certain period.

[0008] The technical objectives of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below.

[0009] According to some embodiments, the battery management device includes: an interface configured to obtain an open circuit voltage (OCV) value of each of the battery cells of the battery; and a controller configured to calculate an OCV difference value representing the amount of change of the OCV value of each battery cell during a reference period, set a classification criterion value based on the distribution of the OCV difference values ​​of the battery cells, and classify the state of the battery cells based on the classification criterion value.

[0010] According to some embodiments, the controller is configured to select a feature point based on a variation in the slope of the OCV difference value in the distribution of the OCV difference values, and to set the OCV difference value corresponding to the feature point as the classification criterion value.

[0011] According to some embodiments, the feature point includes an inflection point where the sign of the OCV difference value slope changes from positive to negative or from negative to positive.

[0012] According to some embodiments, the distribution of the OCV difference values ​​includes the log-logistic distribution of the OCV difference values.

[0013] According to some embodiments, the controller is configured to perform a heat test on reclassified cells among the battery cells that fall within a reclassification range including the classification criterion value, and to classify the state of the reclassified cells based on the result of the heat test.

[0014] According to some embodiments, it further includes a charge / discharge unit configured to apply a charge / discharge current to the reclassification cells; and a shooting unit configured to take a thermal image of the reclassification cells while the charge / discharge current is applied.

[0015] According to some embodiments, the controller is configured to diagnose the state of a reclassification cell among the reclassification cells in which a heat spot is detected in the thermal image as a defective state.

[0016] According to some embodiments, the controller is configured to perform the fever test on suspected FP (false positive) cells among the battery cells that fall within the range between the lower limit of the reclassification range and the classification criterion value.

[0017] According to some embodiments, a battery management method comprises: obtaining an open circuit voltage (OCV) value for each of the battery cells of a battery; calculating an OCV difference value representing the amount of change of the OCV value of each battery cell during a reference period; setting a classification criterion value based on the distribution of the OCV difference values ​​of the battery cells; and classifying the state of the battery cells based on the classification criterion value.

[0018] According to some embodiments, the step of setting the classification criterion value includes: selecting a feature point based on the variation of the slope of the OCV difference value in the distribution of the OCV difference values; and setting the OCV difference value corresponding to the feature point as the classification criterion value.

[0019] According to some embodiments, the feature point includes an inflection point where the sign of the OCV difference value slope changes from positive to negative or from negative to positive.

[0020] According to some embodiments, the distribution of the OCV difference values ​​includes the log-logistic distribution of the OCV difference values.

[0021] According to some embodiments, the battery management method further comprises: a step of performing a heat test on reclassified cells among the battery cells that fall within a reclassification range including the classification criterion value; and a step of classifying the state of the reclassified cells based on the result of the heat test.

[0022] According to some embodiments, the step of performing the heat inspection includes: applying a charge / discharge current to the reclassification cells through a charge / discharge unit; and capturing a thermal image of the reclassification cells through a shooting unit while the charge / discharge current is applied.

[0023] According to some embodiments, the step of classifying the state of the reclassification cells includes the step of diagnosing the state of a reclassification cell among the reclassification cells in which a heat spot is detected in the thermal image as a defective state.

[0024] According to some embodiments, the step of performing the heat test includes the step of performing the heat test on suspected FP cells among the battery cells that fall within the range between the lower limit of the reclassification range and the classification criterion value.

[0025] According to the embodiments disclosed in this document, a battery management device and a battery management method can be provided that can diagnose cell conditions such as micro-short circuits based on the distribution of changes in the OCV value of each cell over a certain period.

[0026] The technical effects according to the embodiments disclosed in this document are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art in accordance with the disclosure of this document.

[0027] FIG. 1 illustrates elements constituting a battery system according to some embodiments.

[0028] FIG. 2 illustrates elements constituting a battery management device according to some embodiments.

[0029] FIG. 3 illustrates a process of reclassifying reclassification cells located near a classification criterion value according to some embodiments based on fever inspection.

[0030] FIG. 4 illustrates a battery management device further comprising a charging / discharging unit and a shooting unit according to some embodiments.

[0031] FIG. 5 illustrates a method for classifying the state of battery cells using a classification criterion value set based on the distribution of OCV difference values ​​according to some embodiments.

[0032] FIG. 6 illustrates steps constituting a battery management method according to some embodiments.

[0033] Hereinafter, embodiments described in this document are described with reference to the accompanying drawings. However, this is not intended to limit the disclosure of this document to specific embodiments and should be understood to include various modifications, equivalents, and / or alternatives to the embodiments described in this document.

[0034] The embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments and should be understood to include various modifications, equivalents, or substitutions of said embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of said items unless the relevant context clearly indicates otherwise.

[0035] In this document, each of the phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” “first,” “second,” “A,” “B,” “(a),” or “(b)” may be used simply to distinguish a component from another component and, unless specifically stated otherwise, do not limit the components in any other aspect (e.g., importance or order).

[0036] In this document, where it is stated that any (e.g., 1) component is "connected," "coupled," or "joined" to another (e.g., 2) component, with or without the terms "functionally" or "communicationly," or where it is stated that the component is "coupled" or "connected," it means that the component may be connected to the other component directly (e.g., by wire or wirelessly) or indirectly (e.g., through a 3) component.

[0037] Methods according to the various embodiments disclosed in this document may be provided as part of a computer program product. The computer program product may be traded between a seller and a buyer as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory, CD-ROM) or distributed online (e.g., download or upload) through an application store or directly between two driver devices. In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0038] According to the embodiments disclosed in this document, each component (e.g., module or program) of the components described above may include a singular or multiple entities, and some of the multiple entities may be separated and placed in other components. According to the embodiments disclosed in this document, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Generally or additionally, multiple components (e.g., module or program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the components of the multiple components in the same or similar manner as those performed by the corresponding components among the multiple components prior to the integration. According to the embodiments disclosed in this document, operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0039] FIG. 1 illustrates elements constituting a battery system according to some embodiments.

[0040] Referring to FIG. 1, the battery system (100) may include a power device (110), a battery (120), and a battery management device (130). However, it is not limited thereto, and some components may be omitted from the battery system (100) or other general-purpose components may be further included in the battery system (100).

[0041] A power device (110) may be configured to charge or discharge a battery (120). The power device (110) may include a power consuming device and / or a power supply device. The power device (110) may discharge the battery (120) while consuming power, or charge the battery (120) while generating power. According to an embodiment, the power consuming device may include a motor for a mobility device such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or an electric bike. The mobility device may also operate as a power supply device for charging the battery (120). The mobility device may drive the motor using the power of the battery (120) or charge the battery (120) with power generated through regenerative braking. According to an embodiment, the power supply device may include a charge / discharger for charging or discharging the battery (120). The charge / discharger may apply a charging current, a charging voltage, a discharging current, and / or a discharging voltage to the battery (120) based on a given profile or cycle.

[0042] The battery (120) may include one or more battery packs. The battery pack of the battery (120) may include a plurality of battery modules, and each battery module may include a plurality of battery cells. According to an embodiment, the battery (120) may be mounted on various types of mobility devices. According to an embodiment, the battery (120) may be utilized in a battery exchange system (BSS) and / or an energy storage system (ESS).

[0043] The battery management device (130) can perform operations for diagnosing, managing, and / or controlling the battery (120). The battery management device (130) can acquire battery data of the battery (120), diagnose or manage the state of the battery (120) based thereon, and control the output or charging and discharging of the battery (120). According to an embodiment, the battery management device (130) may include a battery management system (BMS) configured with the battery (120) in an on-board manner, and / or an external device remotely positioned with the battery (120) in an off-board manner. The external device may include a charger at a battery charging station, a battery diagnostic device, a cloud computing server, etc.

[0044] The battery system (100) may further include a management server. The management server can manage the management results of the battery management device (130). The management server can exchange data with the battery management device (130) via wired or wireless communication. When a defect in the battery (120) is diagnosed or its lifespan is predicted, the results can be transmitted to the management server and recorded in a database. According to an embodiment, the battery management device (130) can perform diagnostic operations by running battery management software, and the management server can provide update information of the battery management software to the battery diagnostic device (130).

[0045] The battery management device (130) can inspect whether a defect, such as an internal short circuit, has occurred during the manufacturing process of the battery (120), or can inspect in real time whether a defect has occurred in the battery (120) while the battery (120) is being used in a mobility device, ESS, BSS, etc.

[0046] FIG. 2 illustrates elements constituting a battery management device according to some embodiments.

[0047] Referring to FIG. 2, the battery management device (130) may include an interface (131) and a controller (132). However, it is not limited thereto, and some components may be omitted from the battery management device (130), or other general-purpose components may be further included in the first battery management device (130).

[0048] The interface (131) may be configured to acquire battery data of the battery (120). According to an embodiment, the interface (131) may include a communication unit configured to receive battery data and / or a sensor unit configured to measure battery data. According to an embodiment, if the battery management device (130) is implemented in an off-board form, the communication unit may receive battery data in a manner such as wired data communication or wireless data communication. Alternatively, if the battery management device (130) is implemented in an on-board form, the sensor unit may be configured to measure values ​​such as voltage, current, temperature, and resistance from the battery (120). According to an embodiment, the battery data may include charging data related to the charging of the battery (120) and / or discharge data related to the discharging of the battery (120). For example, the charging data and / or discharge data may include current data, voltage data, temperature data, capacity data, resistance data, and / or degradation data.

[0049] According to an embodiment, the interface (131) may be configured to obtain the open circuit voltage (OCV) value of each of the battery cells of the battery (120). The OCV may be a voltage measured in an open state where no current flows through the battery (120). For example, when inspecting defects in the manufacturing process, the OCV values ​​of the cells manufactured in the manufacturing facility may be measured, and the battery management device (130) may receive the OCV values ​​through the interface (131) and manage the accumulated values. Alternatively, when inspecting defects occurring during use in a mobility device, etc., the battery management device (130) may periodically directly measure the OCV values ​​of the battery cells of the battery (120) mounted in the mobility device, etc. through a sensor unit, or periodically receive the OCV measurements through a communication unit.

[0050] The controller (132) may have a structure for executing instructions that implement the operations of the battery management device (130). The controller (132) may be implemented as an array of logic gates or a general-purpose microprocessor for processing various operations, and may be composed of a single processor or multiple processors. For example, the controller (132) may be implemented in at least one form of a microprocessor, CPU, GPU, and AP.

[0051] The controller (132) can operate with memory configured to store various data, instructions, mobile applications, computer programs, etc. The memory may be configured separately from or integrally with the controller (132). The controller (132) can process various operations by executing instructions stored in the memory. For example, the memory may be implemented as a non-volatile device such as ROM, PROM, EPROM, EEPROM, flash memory, PRAM, MRAM, RRAM, FRAM, etc., or as a volatile device such as DRAM, SRAM, SDRAM, PRAM, etc., and may be implemented in the form of an HDD, SSD, SD, Micro-SD, etc., or a combination thereof.

[0052] The controller (132) may be configured to calculate an OCV difference value representing the amount of change in the OCV value of each battery cell during a reference period. The reference period may be pre-set for the calculation of the OCV difference value (dOCV). For example, when inspecting the manufacturing state after the completion of manufacturing of the battery (120), or when inspecting the state of the battery (120) after the end of operation of the electric vehicle, the amount of change in the OCV value during the reference period may be calculated to detect the amount of self-discharge. For example, the reference period may be 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, 3 days, 7 days, or other appropriate period. According to an embodiment, the reference period may be newly set for each inspection based on the manufacturing environment or operating environment of the battery (120) instead of a pre-set fixed value. For example, the reference period for calculating the OCV difference value (dOCV) may be determined based on the operating time, driving distance, average speed, battery consumption, etc. of the electric vehicle.

[0053] The controller (132) may be configured to set a classification criterion value based on the distribution of OCV difference values ​​of the battery cells. For example, when inspecting defects during the manufacturing process, the OCV difference values ​​of the completed cells may be collected cumulatively, and the distribution of OCV difference values ​​may be analyzed based on the cumulative data. When inspecting defects that occur while the battery (120) is used in a mobility device, the OCV difference values ​​of the cells constituting the battery (120) may be collected. For example, OCV difference values ​​may be collected whenever the operation of the electric vehicle ends or whenever it is not operated for a long period, and the distribution of OCV difference values ​​may be analyzed based on the data collected n times. For example, the distribution of OCV difference values ​​may be plotted in the form of a two-dimensional graph, a curve, etc., and a classification criterion value for the dOCV value may be set based on the characteristics appearing in the two-dimensional graph, the curve, etc.

[0054] The controller (132) may be configured to classify the state of the battery cells based on a classification criterion value. For example, a cell whose dOCV value exceeds the classification criterion value may be classified as a defective cell having an internal short circuit, a high self-discharge rate, a low voltage phenomenon, etc., and a cell whose dOCV value falls below the classification criterion value may be classified as a normal cell. Various additional actions may be performed depending on the diagnosis results. For example, the battery management device (130) may provide the diagnosis results to a manager of the manufacturing process, or to a user of the battery (120) and / or power device (110) in the form of a warning or notification. Alternatively, if the battery (120) is mounted on a mobility device, etc., the battery management device (130) may control output limitation, performance limitation, open circuit, short circuit, etc., for the cells classified as defective.

[0055] According to an embodiment, the controller (132) may be configured to select feature points based on variations in the slope of the OCV difference value in the distribution of OCV difference values, and to set the OCV difference value corresponding to the feature point as a classification criterion value. For example, the feature point may include a point where the trend of the slope of the OCV difference value changes. The trend change point may be identified by comparing the amount or ratio of slope variation with a threshold. For example, a point where the slope in the initial part of the distribution of OCV difference values ​​transitions to the slope in the latter part may be identified as a feature point. The feature point may be used as a classification criterion value to classify whether the battery cells are defective. For example, a cell having an OCV difference value (dOCV) higher than the classification criterion value may be classified as a defective cell.

[0056] According to the embodiment, the feature point may include an inflection point where the sign of the OCV difference value slope changes from positive to negative or from negative to positive. Among the various types of feature points, the inflection point may be used as a classification criterion value. At the inflection point, the increasing trend of the OCV difference value slope may switch to a decreasing trend, or the decreasing trend may switch to an increasing trend.

[0057] According to the embodiment, the distribution of OCV difference values ​​may include a log-logistic distribution of OCV difference values. For example, the distribution of OCV difference values ​​can be analyzed in the form of various logistic distributions, among which a log-logistic distribution may be utilized. According to the logistic distribution, the OCV difference values ​​of battery cells can be plotted in order from 0% to 100%, and in the case of the log-logistic distribution, the log values ​​of the OCV difference values ​​(dOCV) can be plotted in order from 0% to 100%. When a log-logistic distribution is utilized, the characteristic point where the trend of the dOCV slope changes can be identified more clearly.

[0058] According to an embodiment, the controller (132) may be configured to perform a heat test on reclassified cells that fall within a reclassification range including a classification criterion value among the battery cells, and to classify the state of the reclassified cells based on the result of the heat test. Since the classification criterion value is identified through a statistical method that checks the point of change of the slope trend through a log-logistic distribution, etc., a classification error may occur near the classification criterion value. A heat test may be performed to re-examine whether the cells susceptible to classification errors are defective. The heat test may check whether a heat spot formed at a micro-short circuit site existing inside the cell is detected.

[0059] According to an embodiment, the battery management device (130) may further include a charging / discharging unit configured to apply a charging / discharging current to the reclassified cells; and a shooting unit configured to take a thermal image of the reclassified cells while the charging / discharging current is applied. For example, when inspecting defects occurring during the manufacturing process, the charging / discharging device of the power device (110) may operate as the charging / discharging unit. Alternatively, when inspecting real-time defects of a battery (120) mounted on a mobility device such as an electric vehicle, the charging / discharging current may be applied to the reclassified cells using other cells different from the reclassified cells and / or an electric vehicle motor.

[0060] According to an embodiment, the controller (132) may be configured to diagnose the state of a reclassification cell in which a heat spot is detected in a thermal image among the reclassification cells as a defective state. The shooting unit may include a thermal imaging camera, and based on the thermal imaging camera image, it may be determined whether a heat spot occurs in the reclassification cells due to the charge / discharge current.

[0061] According to an embodiment, the controller (132) may be configured to perform a heat test on suspected FP (false positive) cells among the battery cells that fall within a range between the lower limit of the reclassification range and the classification criterion value. The reclassification range may have an upper limit and a lower limit, and the classification criterion value may be located between the upper limit and the lower limit. Battery cells that fall within a range between the lower limit of the reclassification range and the classification criterion value may be classified as normal cells, but cells located close to the classification criterion value may be FP cells that are actually defective cells but are incorrectly classified as normal cells. Cells that fall within a range between the lower limit of the reclassification range and the classification criterion value may be defined as suspected FP cells, and reclassification through a heat test may be performed on the suspected FP cells. Classification errors may be reduced through reclassification of the suspected FP cells. According to the embodiment, a fever inspection can be performed on suspected FN (false negative) cells that fall within the range between the upper limit of the reclassification range and the classification criterion value, and through this, FN cells that are actually normal cells but are incorrectly classified as defective cells can be detected.

[0062] FIG. 3 illustrates a process of reclassifying reclassification cells located near a classification criterion value according to some embodiments based on fever inspection.

[0063] Referring to FIG. 3, a flow (300) illustrating a process of reclassifying reclassification cells located near a classification criterion value based on fever inspection can be illustrated.

[0064] When a classification criterion value is set in step (310), a fever check may be additionally performed on reclassified cells belonging to the reclassification range in step (320). For example, a fever check may be performed on suspected FP cells belonging to the range between the lower limit value of the reclassification range and the classification criterion value, and / or suspected FN cells belonging to the range between the upper limit value of the reclassification range and the classification criterion value.

[0065] In step (330), the battery management device (130) can analyze a thermal camera image to detect whether a heat spot is detected, and can reclassify cells having a heat spot as defective cells and cells not having a heat spot as normal cells. In step (340), when inspecting for defects during the manufacturing process, defective cells may be transferred to procedures such as disposal or analysis, and normal cells may be transferred to a shipping procedure. Alternatively, when inspecting for defects while mounted on a mobility device such as an electric vehicle, controls such as performance limitation or output limitation on defective cells may be performed, and notifications or warnings regarding defective cells may be provided to the user's registered terminal.

[0066] FIG. 4 illustrates a battery management device further comprising a charging / discharging unit and a shooting unit according to some embodiments.

[0067] Referring to FIG. 4, the battery management device (130) may further include a charging / discharging unit (133) and a shooting unit (134).

[0068] When inspecting defects during the manufacturing process, the charge / discharge unit (133) may be a charge / discharger equipped for charge / discharge testing of the manufactured cells. When inspecting defects during the operation process after being mounted on an electric vehicle, etc., the charge / discharge unit (133) may be a normal cell different from the cell subject to re-inspection, or an electric vehicle motor, etc. The imaging unit (134) may include a thermal imaging camera. The imaging unit (134) may be installed to photograph the battery cells during the cell manufacturing process, or may be installed in a form that can photograph the battery cells during the operation process of the cells mounted on the electric vehicle, etc.

[0069] FIG. 5 illustrates a method for classifying the state of battery cells using a classification criterion value set based on the distribution of OCV difference values ​​according to some embodiments.

[0070] Referring to FIG. 5, a graph (500) illustrating a method of classifying the state of battery cells using a classification criterion value set based on the distribution of OCV difference values ​​may be shown.

[0071] The graph (500) may represent the log-logistic distribution of the OCV difference values ​​of the battery cells. For example, in the graph (500), the horizontal axis may represent the log value of the OCV difference value (dOCV), and the vertical axis may represent the cumulative distribution of the battery cells in the range from 0% to 100%.

[0072] Feature points can be selected based on the variation in the slope of the OCV difference value (dOCV) in the log-logistic distribution of the graph (500). Feature points can be selected based on the trend variation of the dOCV slope. For example, feature points can be selected at the point where the initial slope transitions to the later slope.

[0073] The feature point can be treated as a classification criterion value (510). Cells having a dOCV higher than the classification criterion value (510) can be classified as defective cells. For example, as illustrated, about 1% of the cells among the battery cells constituting the accumulated finished cells, electric vehicle battery packs, ESS, etc. can be classified as primary defective cells.

[0074] A range of approximately 5% before and after the classification standard value (510) can be set as the reclassification range. For example, for a classification standard value (510) of 1.16 mV, a range of 1.11 mV to 1.21 mV can be set as the reclassification range. According to the embodiment, the reclassification range can be newly set for each inspection based on the manufacturing environment of the battery cell or the operating environment of the cells installed in the electric vehicle.

[0075] The range between the classification threshold value (510) and the lower limit value (520) of the reclassification range may include suspected FP cells that are actually defective cells but are classified as normal cells. Additional fever checks may be performed on the suspected FP cells, and based on this, the classification accuracy may be improved.

[0076] FIG. 6 illustrates steps constituting a battery management method according to some embodiments.

[0077] Referring to FIG. 6, the battery management method (600) may include steps (610) through (640). However, it is not limited thereto, some steps may be omitted or other general steps may be added, and the steps of the battery management method (600) may be executed in a different order than the illustrated order.

[0078] The battery management method (600) may consist of steps processed sequentially in the battery management device (130). Therefore, even if the details are omitted below, the description of the battery management device (130) above may be equally applicable to the battery management method (600).

[0079] Steps (610) to (640) of the battery management method (600) can be performed by the interface (131) and controller (132) of the battery management device (130).

[0080] In step (610), the battery management device (130) can perform the step of obtaining the open circuit voltage (OCV) value of each of the battery cells of the battery.

[0081] In step (620), the battery management device (130) may perform the step of calculating an OCV difference value representing the amount of change in the OCV value of each battery cell during a reference period.

[0082] In step (630), the battery management device (130) may perform the step of setting a classification criterion value based on the distribution of OCV difference values ​​of the battery cells.

[0083] In step (640), the battery management device (130) can perform the step of classifying the state of the battery cells based on a classification criterion value.

[0084] According to an embodiment, the battery management method (600) may be implemented in the form of a computer program stored on a computer-readable storage medium. That is, the computer program may include instructions for implementing the battery management method (600), and the instructions of the program may be stored on a computer-readable storage medium. The computer program may include a mobile application.

[0085] According to an embodiment, a computer-readable storage medium may include magnetic media such as a hard disk, a floppy disk, and a magnetic tape, optical media such as a CD-ROM and a DVD, magneto-optical media such as a floptical disk, and a hardware device specifically configured to store and execute computer program instructions such as ROM, RAM, and flash memory. Computer program instructions may include machine code generated by a compiler and high-level language code that can be executed by a computer using an interpreter, etc.

[0086] Terms such as "include," "compose," or "have" as used above, unless specifically stated otherwise, mean that the relevant component may be inherent; therefore, they should be interpreted as allowing for the inclusion of additional components rather than excluding them. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments disclosed in this document pertain, unless otherwise defined. Commonly used terms, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and, unless explicitly defined in this document, should not be interpreted in an ideal or overly formal sense.

[0087] The foregoing description is merely an illustrative explanation of the technical concept disclosed in this document, and a person skilled in the art to which the embodiments disclosed in this document pertain can make various modifications and variations within the scope of the essential characteristics of the embodiments disclosed in this document. Accordingly, the embodiments disclosed in this document are intended to explain, not limit, the technical concept of the embodiments disclosed in this document, and the scope of the technical concept disclosed in this document is not limited by these embodiments. The scope of protection of the technical concept disclosed in this document shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of this document.

Claims

1. An interface configured to acquire the open circuit voltage (OCV) value of each of the battery cells of the battery; and Calculate an OCV difference value representing the amount of change in the OCV value of each battery cell during a reference period, and A classification criterion value is set based on the distribution of OCV difference values ​​of the above battery cells, and A battery management device comprising a controller configured to classify the state of the battery cells based on the above classification criteria value.

2. In Paragraph 1, The above controller selects feature points based on variations in the slope of the OCV difference values ​​in the distribution of the OCV difference values, and A battery management device configured to set an OCV difference value corresponding to the above feature point as the above classification criterion value.

3. In Paragraph 2, A battery management device comprising a feature point including an inflection point where the sign of the slope of the OCV difference value changes from positive to negative or from negative to positive.

4. In Paragraph 2, A battery management device wherein the distribution of the above OCV difference values ​​includes the log-logistic distribution of the above OCV difference values.

5. In Paragraph 1, The above controller performs a heat test on the reclassified cells among the battery cells that fall within a reclassification range including the classification criterion value, and A battery management device configured to classify the status of the reclassification cells based on the results of the above-mentioned heat inspection.

6. In Paragraph 5, A charge / discharge unit configured to apply a charge / discharge current to the above-mentioned reclassification cells; and A battery management device further comprising a shooting unit configured to capture a thermal image of the reclassification cells while the above-mentioned charging and discharging current is applied.

7. In Paragraph 5, A battery management device configured such that the controller above diagnoses the state of a reclassification cell among the reclassification cells in which a heat spot is detected in the thermal image as a defective state.

8. In Paragraph 5, A battery management device configured such that the controller performs the heat test on suspected FP (false positive) cells among the battery cells that fall within the range between the lower limit of the reclassification range and the classification criterion value.

9. A step of obtaining the open circuit voltage (OCV) value of each of the battery cells of the battery; A step of calculating an OCV difference value representing the amount of change in the OCV value of each battery cell during a reference period; A step of setting a classification criterion value based on the distribution of OCV difference values ​​of the battery cells; and A battery management method comprising the step of classifying the state of the battery cells based on the above classification criteria value.

10. In Paragraph 9, The step of setting the above classification criteria value is, A step of selecting feature points based on the variation of the slope of the OCV difference values ​​in the distribution of the above OCV difference values; and A battery management method comprising the step of setting an OCV difference value corresponding to the above feature point as the above classification criterion value.

11. In Paragraph 10, A battery management method comprising the above feature point including an inflection point where the sign of the slope of the OCV difference value changes from positive to negative or from negative to positive.

12. In Paragraph 10, A battery management method wherein the distribution of the above OCV difference values ​​includes the log-logistic distribution of the above OCV difference values.

13. In Paragraph 9, A step of performing a heat test on reclassified cells among the battery cells that fall within a reclassification range including the classification criterion value; and A battery management method further comprising the step of classifying the state of the reclassified cells based on the result of the above-mentioned heat test.

14. In Paragraph 13, The step of performing the above fever check is, A step of applying a charge / discharge current to the reclassification cells through a charge / discharge unit; and A battery management method comprising the step of capturing a thermal image of the reclassification cells while the charge / discharge current is applied through a shooting unit.

15. In Paragraph 13, The step of classifying the status of the above-mentioned reclassification cells is, A battery management method comprising the step of diagnosing the state of a reclassification cell in which a heat spot is detected in the thermal image among the reclassification cells as a defective state.

16. In Paragraph 13, The step of performing the above fever check is, A battery management method comprising the step of performing the heat test on suspected FP cells among the battery cells that fall within the range between the lower limit of the reclassification range and the classification criterion value.

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