Battery diagnosis device and battery diagnosis method

Abstract

A battery diagnostic device according to embodiments of the present document includes a memory configured to store at least one instruction, at least one processor configured to execute the at least one instruction, and the at least one processor is configured to acquire an open-circuit voltage (OCV) for each first state of charge based on at least one of charging data of a battery cell, discharging data of the battery cell, or any combination thereof, according to a state of charge amount indicating an amount of charge charged in the battery cell, acquire a degradation index based on the OCV for each first state of charge, and diagnose a state of the battery cell based on the degradation index.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2024-0102814, filed on August 2, 2024, the disclosure of which is incorporated herein by reference. Technical Field

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

[0005] Recently, research and development of secondary batteries have been actively pursued. Here, a secondary battery is a battery that can be charged and discharged, and can be interpreted as including conventional Ni / Cd batteries, Ni / MH batteries, and more recently, lithium-ion batteries. The applications of secondary batteries have recently expanded to include power sources for electric vehicles, and they are attracting attention as a next-generation energy storage medium.

[0006] With the surge in electronic devices driven by the Fourth Industrial Revolution, battery usage is increasing dramatically. Batteries are in the spotlight as a fundamental energy source in a wide range of applications, and therefore, the importance of technologies for diagnosing battery condition to improve battery performance and reliability is growing.

[0007] In particular, technologies for improving the accuracy of degradation indicators that diagnose the degree of battery deterioration are attracting attention. Improving the accuracy of battery degradation indicators allows for the early detection and prevention of problems caused by battery degradation. Summary of the Invention

[0008] Technical issues

[0009] The embodiments disclosed in this document provide a battery diagnostic device and a battery diagnostic method that reduce the resources required for battery diagnostics by reducing the resources needed to acquire charging and discharging data for obtaining degradation indicators.

[0010] The embodiments disclosed in this document provide a battery diagnostic device and a battery diagnostic method that identify degradation indicators while reducing the resources required to acquire charging and discharging data for obtaining degradation indicators.

[0011] The embodiments disclosed in this document provide a battery diagnostic device and a battery diagnostic method that monitor potential problems due to battery degradation by identifying degradation indicators.

[0012] The technical problems of the embodiments disclosed in this document are not limited to the above-described technical problems, and those skilled in the art can clearly understand other technical problems not mentioned based on the following description.

[0013] Technical solution

[0014] A battery diagnostic device according to an embodiment of this document includes: a memory configured to store at least one instruction; and at least one processor configured to execute at least one instruction.

[0015] According to an embodiment, at least one processor is configured to: obtain the open-circuit voltage (OCV) of each first charge quantity based on at least one of the charging data of the battery cell, the discharging data of the battery cell, or any combination thereof, according to the charge quantity indicating the amount of charge charged in the battery cell, obtain a degradation index based on the open-circuit voltage of each first charge quantity, and diagnose the state of the battery cell based on the degradation index.

[0016] According to an embodiment, at least one processor can be configured to: identify the open-circuit voltage corresponding to the charge amount based on: a) a first voltage value of a battery cell corresponding to the charge amount and included in the charging data, b) a first current value of a battery cell corresponding to the charge amount and included in the charging data, c) a second voltage value of a battery cell corresponding to the charge amount and included in the discharging data, and d) a second current value of a battery cell corresponding to the charge amount and included in the discharging data, and identify the open-circuit voltage of each first charge amount based on the charge amount and the open-circuit voltage.

[0017] According to an embodiment, at least one processor can be configured to: identify the voltage value of a battery cell corresponding to the current value of the battery cell when the current value of the battery cell is less than a specified current value, based on a linear equation identified based on the relationship between a first current value and a first voltage value and the relationship between a second current value and a second voltage value, and identify the open-circuit voltage corresponding to the charge amount based on the voltage value of the battery cell.

[0018] According to an embodiment, at least one processor may be configured to: obtain parameters based on at least one of the following: i) an optimization algorithm, ii) the open-circuit voltage of each charge of a battery cell in the middle of life (MOL) state indicated by the open-circuit voltage of each first charge, iii) the open-circuit voltage of each third charge of a battery cell in the beginning of life (BOL) state, iv) the open-circuit potential (OCP) of each charge of a battery cell in the BOL state, or v) any combination thereof, and obtain a degradation index based on the parameters.

[0019] According to an embodiment, at least one processor can be configured to use a genetic algorithm (GA) to execute an optimization algorithm.

[0020] According to an embodiment, at least one processor can be configured to acquire at least one of charging data, discharging data, or any combination thereof based on charging and discharging curves. Through the charging and discharging curves, a battery cell is charged a specific number of times at a current value higher than a reference current, from a lower limit charge value higher than a first reference charge value to an upper limit charge value lower than a second reference charge value, the specific number of times being less than the reference number, and the battery cell is discharged a specific number of times at a current value, from the upper limit charge value to the lower limit charge value.

[0021] According to an embodiment, the degradation index may include: lithium inventory loss (LLI), which includes a first parameter related to lithium loss in a battery cell at mid-life (MOL) compared to the beginning of life (BOL); first active material loss (LAM), which includes a second parameter related to loss of active material in the negative electrode of a battery cell at MOL compared to BOL; or second active material loss (LAM), which includes a third parameter related to loss of active material in the positive electrode of a battery cell at MOL compared to BOL.

[0022] The battery diagnostic method according to the embodiments of this document includes: an operation of obtaining the open-circuit voltage (OCV) of each first charge quantity based on at least one of the charging data of a battery cell, the discharging data of a battery cell, or any combination thereof, according to the charge quantity indicating the amount of charge charged in the battery cell; an operation of obtaining a degradation index based on the open-circuit voltage of each first charge quantity; and an operation of diagnosing the state of the battery cell based on the degradation index.

[0023] According to an embodiment, the operation of obtaining the open-circuit voltage (OCV) of each first charge quantity based on at least one of the charging data, discharging data, or any combination thereof of battery cells, and according to the charge quantity indicating the amount of charge charged in the battery cell, may include: identifying the open-circuit voltage corresponding to the charge quantity based on: a) a first voltage value of the battery cell corresponding to the charge quantity and included in the charging data, b) a first current value of the battery cell corresponding to the charge quantity and included in the charging data, c) a second voltage value of the battery cell corresponding to the charge quantity and included in the discharging data, and d) a second current value of the battery cell corresponding to the charge quantity and included in the discharging data; and identifying the open-circuit voltage of each first charge quantity based on the charge quantity and the open-circuit voltage.

[0024] According to an embodiment, the operation of identifying the open-circuit voltage corresponding to the charge amount based on the following: a) a first voltage value of a battery cell corresponding to the charge amount and included in the charging data, b) a first current value of a battery cell corresponding to the charge amount and included in the charging data, c) a second voltage value of a battery cell corresponding to the charge amount and included in the discharging data, and d) a second current value of a battery cell corresponding to the charge amount and included in the discharging data, may include: identifying the voltage value of a battery cell corresponding to the current value of a battery cell when the current value of a battery cell is less than a specified current value, based on a linear equation identified based on the relationship between the first current value and the first voltage value and the relationship between the second current value and the second voltage value; and identifying the open-circuit voltage corresponding to the charge amount based on the voltage value of the battery cell.

[0025] According to an embodiment, the operation of obtaining a degradation index based on the open-circuit voltage of each first charge may include: obtaining parameters based on at least one of the following: i) an optimization algorithm, ii) the open-circuit voltage of each charge of a battery cell in the intermediate lifetime (MOL) state indicated by the open-circuit voltage of each first charge, iii) the open-circuit voltage of each third charge of a battery cell in the beginning lifetime (BOL) state, iv) the open-circuit potential (OCP) of each charge of a battery cell in the BOL state, or v) any combination thereof; and obtaining the degradation index based on the parameters.

[0026] According to an embodiment, the operation of obtaining parameters based on at least one of the following: i) an optimization algorithm, ii) the open-circuit voltage of each charge of a battery cell in the middle of life (MOL) state indicated by the open-circuit voltage of each first charge, iii) the open-circuit voltage of each third charge of a battery cell in the beginning of life (BOL) state, iv) the open-circuit potential (OCP) of each charge of a battery cell in the BOL state, or v) any combination thereof, may include: the operation of performing an optimization algorithm using a genetic algorithm (GA).

[0027] According to an embodiment, the battery diagnostic method may further include: charging a battery cell a specific number of times at a current value higher than a reference current, from a lower limit charge value higher than a first reference charge value to an upper limit charge value lower than a second reference charge value, wherein the specific number of times is less than the reference number; and acquiring at least one of charging data, discharging data, or any combination thereof based on charging and discharging curves, wherein the battery cell is discharged a specific number of times at a current value from an upper limit charge value to a lower limit charge value, based on the charging and discharging curves.

[0028] According to an embodiment, the degradation index may include: lithium inventory loss (LLI), which includes a first parameter related to lithium loss in a battery cell at mid-life (MOL) compared to the start of life (BOL); first active material loss (LAM), which includes a second parameter related to loss of active material in the negative electrode plate of a battery cell at MOL compared to BOL; or second active material loss (LAM), which includes a third parameter related to loss of active material in the positive electrode plate of a battery cell at MOL compared to BOL.

[0029] Beneficial effects

[0030] This technology can reduce the resources required for battery diagnostics by reducing the resources needed to acquire charging and discharging data for obtaining degradation indicators.

[0031] In addition, this technology can identify degradation indicators while reducing the resources required to acquire charging and discharging data for obtaining degradation indicators.

[0032] In addition, this technology can monitor potential problems caused by battery degradation by identifying degradation indicators.

[0033] In addition, it can provide various effects that can be identified directly or indirectly through this document. Attached Figure Description

[0034] Figure 1 This is a block diagram illustrating a battery pack in a battery diagnostic device and battery diagnostic method according to embodiments of this document.

[0035] Figure 2 This is a block diagram illustrating the configuration of the battery diagnostic device in the battery diagnostic device and battery diagnostic method according to embodiments of this document.

[0036] Figure 3 Examples of charging and discharging data in a battery diagnostic device and battery diagnostic method according to embodiments of this document are illustrated.

[0037] Figure 4 An example of obtaining the open-circuit voltage for each first charge quantity is illustrated in the battery diagnostic apparatus and battery diagnostic method according to embodiments of this document.

[0038] Figure 5 An example of an optimization algorithm being executed in a battery diagnostic device and battery diagnostic method according to embodiments of this document is illustrated.

[0039] Figure 6 Examples of degradation indicators in battery diagnostic devices and battery diagnostic methods according to embodiments of this document are illustrated.

[0040] Figure 7 The illustration shows an example of the operation flow of a battery diagnostic device that diagnoses the condition of a battery cell based on degradation indicators in a battery diagnostic device and battery diagnostic method according to embodiments of this document.

[0041] Figure 8 This is a block diagram illustrating the hardware configuration of the computing system executing the battery diagnostic method in a battery diagnostic device and battery diagnostic method according to embodiments of this document. Detailed Implementation

[0042] In the following description, some embodiments described in this document are illustrated with reference to the accompanying drawings. However, this is not intended to limit the technology to the specific embodiments, but should be understood to include various modifications, equivalents, and / or substitutions of the embodiments incorporating the technology.

[0043] When adding reference numerals to components in each figure, care should be taken to give the same reference numerals as much as possible, even if the same component is shown in different figures. Additionally, when describing the various embodiments disclosed in this document, detailed descriptions of related known configurations or functions are omitted if they are determined to impede understanding of the embodiments of this disclosure. Unless the relevant context clearly indicates otherwise, the singular form of the noun corresponding to an item may include one or more items.

[0044] In describing the components of the embodiments described in this document, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are intended only to distinguish components from other components, and the nature, order, or sequence of components is not limited by these terms. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments disclosed in this document pertain. Terms defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an ideal or overly formal sense unless expressly defined in this application.

[0045] Furthermore, in this disclosure, the expressions "greater than" or "less than" may be used to determine whether a particular condition is met or achieved, but this is merely a description for illustrative purposes and does not exclude descriptions of "greater than or equal to" or "less than or equal to". A condition described as "greater than or equal to" may be replaced with "more than", a condition described as "less than or equal to" may be replaced with "less than", and a condition described as "greater than or equal to and less than" may be replaced with "more than and less than or equal to". Additionally, in the following text, "A" to "B" means at least one of the elements from A (inclusive) to B (inclusive).

[0046] In this document, each of the phrases “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.

[0047] In this document, when a component (e.g., the first component) is referred to as “connected,” “coupled,” or “joined” to another component (e.g., the second component) with or without the terms “functionally” or “communically”, it means that the component can be connected to the other component directly (e.g., via a wired connection), wirelessly, or via a third component.

[0048] Methods according to various embodiments disclosed in this document can be provided by including the computer program product. The computer program product can be traded as a product between a seller and a buyer. The computer program product can be distributed in the form of a machine-readable recording medium (e.g., an optical disc read-only memory (CD-ROM)), or distributed through an app store, directly between two user devices, or online (e.g., downloaded or uploaded). In the case of online distribution, at least a portion of the computer program product can be temporarily stored or temporarily generated in a machine-readable recording medium (such as the memory of a manufacturer's server, an app store's server, or a relay server).

[0049] According to various embodiments, each of the above-described components (e.g., modules or programs) may include one or more entities, and some of the multiple entities may be separated and placed in other components. According to various embodiments, one or more of the above-described components or operations may be omitted, or one or more other components or operations may be added. Alternatively or additionally, multiple components (e.g., modules or programs) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as those functions performed by the corresponding components among the multiple components prior to integration. According to various embodiments, operations performed by modules, programs, or other components may be performed sequentially, in parallel, repeatedly, or heuristically, or one or more operations may be performed in different orders, omitted, or by adding one or more other operations.

[0050] In the following text, reference will be made to Figures 1 to 8 The embodiments described in this document are described in detail.

[0051] Figure 1 This is a block diagram illustrating a battery pack in a battery diagnostic device and battery diagnostic method according to embodiments of this document.

[0052] refer to Figure 1The battery pack 1 may include battery cells 12, sensor units 14, switching units 16, and a battery management system (BMS) 20. In this case, the battery pack 1 may be equipped with multiple battery cells 12, sensor units 14, switching units 16, and battery management systems 20.

[0053] According to an embodiment, battery cell 12 can supply power to a target device (not shown). For this purpose, battery cell 12 can be electrically connected to the target device. Here, the target device can include electrical, electronic, or mechanical devices that operate by receiving power from battery pack 1. For example, the target device can be, but is not limited to, an electric vehicle (EV) or an energy storage system (ESS).

[0054] According to an embodiment, the battery cell 12 may include at least one battery cell 10 capable of being charged and discharged. Here, the battery cell 10 may be a basic unit of a battery cell that can be used by charging and discharging energy. For example, the battery cell 10 may be a lithium-ion (Li-ion) battery, a lithium-ion polymer battery, a nickel-cadmium (Ni-Cd) battery, a nickel metal hydride (Ni-MH) battery, etc., but is not limited thereto.

[0055] According to the embodiments, multiple battery cells 12 can be connected in series or in parallel. For example, a battery cell 12 can be a battery module, a battery pack, or a group of battery cells (cell-to-pack structure).

[0056] According to an embodiment, sensor unit 14 can acquire information related to battery cell 12. According to an embodiment, sensor unit 14 can acquire values ​​(or information) related to the state of each battery cell 12 or battery unit 10. In an embodiment, the state-related values ​​may include one or more values ​​of the battery unit's voltage, current, resistance, state of charge (SOC), state of health (SOH), or temperature, or combinations thereof.

[0057] According to an embodiment, sensor unit 14 can provide information about each of the plurality of battery cells 12 to battery management system 20.

[0058] According to an embodiment, the switching unit 16 may include a device for controlling the current used to charge or discharge the battery cell 12. For example, depending on the specifications of the battery pack, the switching unit 16 may include at least one relay and / or magnetic contactor, etc.

[0059] According to an embodiment, the battery management system (BMS) 20 can control or manage the battery pack 1 to prevent overcharging and over-discharging by monitoring the voltage, current, temperature, etc. of the battery pack 1. For example, the battery management system 20 is an interface that receives values ​​obtained by measuring the various parameters mentioned above, and may include multiple terminals, circuitry connected to these terminals to process the received values, etc. In addition, the battery management system 20 can control the sensor unit 14 and / or the switching unit 16. For example, the battery management system 20 can be connected to multiple battery cells 12 to monitor the state of each of the multiple battery cells 12 and control the on / off state of relays or contactors, etc.

[0060] According to an embodiment, the operation of the battery management system 20 can be performed by the battery management system (BMS) in the vehicle, and can also be performed in various devices such as servers, cloud, chargers, or chargers / dischargers.

[0061] The upper-level controller 2 can transmit control signals for the multiple battery cells 12 to the battery management system 20. Therefore, the operation of the battery management system 20 can be controlled based on the signals applied from the upper-level controller 2.

[0062] According to an embodiment, the battery management system 20 may include Figure 2 The battery diagnostic device 201. According to another embodiment, the battery management system 20 can be integrated with... Figure 2 Battery diagnostic equipment 201 different systems. That is to say, Figure 2 The battery diagnostic device 201 can be included in the battery pack 1, or it can be configured as another device outside the battery pack 1. In the following description, for ease of description, it will be based on the assumption that the battery diagnostic device 201 is composed of another device outside the battery pack 1. Furthermore, the operation of the battery diagnostic device 201 described below can be performed by the BMS in the vehicle, and can be performed by various devices such as servers, cloud, chargers, or dischargers.

[0063] Figure 2 This is a block diagram illustrating the configuration of the battery diagnostic device in the battery diagnostic device and battery diagnostic method according to embodiments of this document.

[0064] refer to Figure 2 The battery diagnostic device 201 may include a memory 203 and at least one processor 205. The memory 203 may store at least one instruction. The at least one processor 205 may execute at least one instruction.

[0065] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can perform a reference performance test (RPT) to diagnose... Figure 1 The state of the individual battery cell (e.g., battery cell 10).

[0066] According to an embodiment, during a reference performance test (RPT), at least one processor 205 of the battery diagnostic device 201 can charge or discharge a battery cell and acquire electrical parameter values ​​(e.g., current, voltage, and SOC) of the battery cell. SOC can indicate the amount of charge being charged into the battery cell.

[0067] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can acquire at least one of charging data and discharging data based on charging and discharging curves. Using these charging and discharging curves, the battery cell is charged a specific number of times with a current value higher than a reference current, from a lower limit charge value higher than a first reference charge value to an upper limit charge value lower than a second reference charge value, where the specific number of times is less than the reference number. The battery cell is also discharged a specific number of times with a current value from the upper limit charge value to the lower limit charge value. The at least one processor 205 of the battery diagnostic device 201 can diagnose the state of the battery cell based on the charging and discharging data. Furthermore, the at least one processor 205 of the battery diagnostic device 201 can even measure the open-circuit voltage using a current value greater than or equal to a specified current value. According to the embodiment, the time and electrical resources consumed by the battery diagnostic device 201 to diagnose the state of the battery cell can be less than those consumed by existing battery diagnostic devices.

[0068] Open-circuit voltage indicates the voltage in a state where a single cell is not connected to an external circuit and no current flows.

[0069] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can obtain the open-circuit voltage of each charge of a battery cell in the mid-life (MOL) state based on charging data and discharging data.

[0070] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can obtain degradation indicators (e.g., first LAM as active material loss (LAM) of the negative electrode plate, second LAM as LAM of the positive electrode plate, and lithium inventory loss (LLI)) based on the open circuit voltage of each SOC of the battery cell in the MOL state, the open circuit voltage of each SOC of the battery cell in the BOL state, and the open circuit potential (OCP) of the battery cell in the BOL state.

[0071] The first LAM may include a second parameter related to the loss of active material in the negative electrode of the battery cell at MOL, compared to BOL. The second LAM may include a third parameter related to the loss of active material in the positive electrode of the battery cell at MOL, compared to BOL. LLI may include a first parameter related to lithium loss in the battery cell at MOL, compared to BOL.

[0072] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can obtain a final degradation index by correcting the acquired degradation index.

[0073] The following will be Figures 3 to 6 The description covers obtaining final degradation indicators by efficiently utilizing the time and electrical resources of the battery diagnostic device 201.

[0074] Figure 3 Examples of charging and discharging data in a battery diagnostic device and battery diagnostic method according to embodiments of this document are illustrated.

[0075] refer to Figure 3 Table 301 may represent the data obtained by the battery diagnostic device 201 according to the embodiment. Figure 1 The charging and discharging data of the individual battery cells (e.g., battery cell 10). Graph 311 can represent the open-circuit voltage based on the SOC identified according to Table 301. The first line 313 of graph 311 can represent the open-circuit voltage identified based on the charging data. The second line 315 can represent the open-circuit voltage identified based on the discharging data.

[0076] According to an embodiment, the first line 313, which represents the open-circuit voltage identified based on charging data, and the second line 315, which represents the open-circuit voltage identified based on discharging data, may not be matched.

[0077] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can separate charging data and discharging data included in Table 301 based on the State of Charge (SOC) in order to identify a single open-circuit voltage based on the SOC.

[0078] For example, when at least one processor 205 of the battery diagnostic device 201 can identify charging and discharging data based on a curve, it can acquire two voltage values ​​and two current values ​​according to a specific SOC and perform a charging and discharging operation through the curve.

[0079] Figure 4 An example of obtaining the open-circuit voltage for each first SOC is illustrated in a battery diagnostic device and battery diagnostic method according to embodiments of this document.

[0080] refer to Figure 4The first curve 401 may include a voltage curve of the current corresponding to the first SOC. The second curve 409 may include a voltage curve of the current corresponding to the second SOC. The third curve 411 may include a voltage curve of the current corresponding to the third SOC. The fourth curve 413 may include a voltage curve of the current corresponding to the fourth SOC. The fifth curve 421 may include an open-circuit voltage curve based on the SOC. The first line 423 of the fifth curve 421 may represent the open-circuit voltage identified based on charging data. The second line 425 of the fifth curve 421 may represent the open-circuit voltage identified based on charging and discharging data. The third line 427 of the fifth curve 421 may represent the open-circuit voltage identified based on discharging data.

[0081] According to the embodiment, the first curve 401 can correspond to the first SOC, the second curve 409 can correspond to the second SOC, the third curve 411 can correspond to the third SOC, and the fourth curve 413 can correspond to the fourth SOC.

[0082] According to an embodiment, at least one processor can be configured to identify the open-circuit voltage corresponding to the SOC based on: a) a first voltage value of a battery cell corresponding to the SOC (e.g., the voltage value corresponding to the second point 407) and included in the charging data; b) a first current value of a battery cell corresponding to the SOC and included in the charging data (e.g., the current value corresponding to the second point 407); c) a second voltage value of a battery cell corresponding to the SOC and included in the discharging data (e.g., the voltage value corresponding to the first point 403); and d) a second current value of a battery cell corresponding to the SOC and included in the discharging data (e.g., the current value corresponding to the first point 403), and to identify the open-circuit voltage of each SOC based on the SOC and the open-circuit voltage.

[0083] According to an embodiment, in the first graph 401, the first point 403 can be correlated with a single battery cell (e.g., Figure 1 The second current value of the battery cell 10) corresponds to the second voltage value of the battery cell. The second current value corresponds to the first SOC and is included in the discharge data. The second voltage value corresponds to the first SOC and is included in the discharge data.

[0084] According to an embodiment, in the first graph 401, the second point 407 may correspond to the first current value and the first voltage value of the battery cell. The first current value corresponds to the first SOC and is included in the charging data, and the first voltage value corresponds to the first SOC and is included in the discharging data.

[0085] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can identify a regression equation based on a first point 403 and a second point 407. The at least one processor 205 of the battery diagnostic device 201 can identify a regression line 405 based on a linear equation, which is a regression equation. In other words, the regression line 405 can represent a linear equation identified based on the relationship between a first current value and a first voltage value, and the relationship between a second current value and a second voltage value.

[0086] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can identify the voltage value of a battery cell corresponding to a situation where the current value of the battery cell is less than a specified current value (e.g., the current value of the battery cell is approximately 0A (Amperes)) based on a regression line 405. At least one processor 205 of the battery diagnostic device 201 can identify the open-circuit voltage based on the voltage value of the battery cell corresponding to the situation where the current value of the battery cell is less than the specified current value, according to a first SOC.

[0087] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can identify the open-circuit voltage based on the second SOC according to the second curve 409.

[0088] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can identify the open-circuit voltage based on a third SOC according to a third curve 411.

[0089] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can identify the open-circuit voltage based on the fourth SOC according to the fourth curve 413.

[0090] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can identify the open-circuit voltage of each SOC based on the open-circuit voltage of the first SOC, the open-circuit voltage of the second SOC, the open-circuit voltage of the third SOC, and the open-circuit voltage of the fourth SOC, as shown in the second row 425 of the fifth graph 421.

[0091] Figure 5 An example of an optimization algorithm being executed in a battery diagnostic device and battery diagnostic method according to embodiments of this document is illustrated.

[0092] refer to Figure 5 Graph 501 can represent the effect on a single battery cell (e.g., Figure 1The voltage of the state of charge (SOC) of the battery cell 10. The positive electrode potential 503 may include the positive electrode potential of the battery cell estimated at the MOL time point. The negative electrode potential 505 may include the negative electrode potential of the battery cell estimated at the MOL time point. The first open-circuit voltage 507 may include the open-circuit voltage of the battery cell identified at the MOL time point. The second open-circuit voltage 509 may represent the open-circuit voltage of the battery cell identified based on the positive electrode potential 503 and the negative electrode potential 505. For example, the second open-circuit voltage 509 may represent the difference between the positive electrode potential 503 and the negative electrode potential 505.

[0093] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 may acquire parameters based on at least one of the following: i) an optimization algorithm (e.g., a genetic algorithm (GA)), ii) the open-circuit voltage of each second SOC of a battery cell in the middle of life (MOL) state indicated by the open-circuit voltage of each first SOC, iii) the open-circuit voltage of each third SOC of a battery cell in the beginning of life (BOL) state, iv) the open-circuit potential (OCP) of each SOC of a battery cell in the BOL state, or v) any combination thereof, and acquire degradation indices based on the parameters.

[0094] At least one processor 205 of the battery diagnostic device 201 according to the embodiment can obtain a positive electrode potential 503 and a negative electrode potential 505 using the positive electrode potential at the BOL time point and the negative electrode potential at the BOL time point, respectively. For example, at least one processor 205 of the battery diagnostic device 201 can obtain the positive electrode potential 503 and the negative electrode potential 505 by applying different shrinkage rates to the SOC region. That is, at least one processor 205 of the battery diagnostic device 201 can obtain parameters corresponding to each SOC region.

[0095] At least one processor 205 of the battery diagnostic device 201 according to an embodiment can calculate the deviation between the second open-circuit voltage 509 in the BOL state and the first open-circuit voltage 507 in the MOL state in each SOC range of a battery cell. The processor according to an embodiment can calculate a parameter that minimizes the deviation across the entire SOC range.

[0096] When the deviation is minimized, at least one processor 205 of the battery diagnostic device 201 can obtain a second open-circuit voltage 509 that is substantially equal to the first open-circuit voltage 507. That is, at least one processor 205 of the battery diagnostic device 201 can perform parameter optimization by identifying the positive electrode potential 503 and the negative electrode potential 505 used to match the first open-circuit voltage 507 and the second open-circuit voltage 509.

[0097] In an embodiment, at least one processor 205 of the battery diagnostic device 201 can acquire a positive electrode potential 503 and a negative electrode potential 505 corresponding to the second open circuit voltage 509 acquired at the MOL time point by acquiring a second open circuit voltage 509 that is substantially equal to the first open circuit voltage 507.

[0098] For example, at least one processor 205 of the battery diagnostic device 201 can compare the positive electrode potential 503 and the negative electrode potential 505 with the positive electrode potential and the negative electrode potential obtained at the BOL time point, respectively, to obtain the shrinkage rate of the positive electrode potential, the offset of the positive electrode potential, the shrinkage rate of the negative electrode potential and / or the offset of the negative electrode potential.

[0099] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can use parameters to diagnose the state of a single battery cell. For example, at least one processor 205 of the battery diagnostic device 201 can use Equations 1 to 3 to obtain degradation indicators.

[0100] [Equation 1]

[0101] Referring to Equation 1, the loss of active material (LAMn) can represent the degree of loss of active material in the battery contained in the negative electrode. This can represent the rate of contraction of the negative electrode potential measured at the BOL time point. As an example, It can be 1, but is not limited to this. This can represent the shrinkage rate of the negative electrode potential estimated at the MOL time point. The shrinkage rate of the negative electrode potential estimated at the MOL time point can be included in the parameters optimized by a specified algorithm.

[0102] [Equation 2]

[0103] Referring to Equation 2, the loss of active material potential (LAMp) can represent the degree of loss of active material in the battery contained in the positive electrode. This can represent the rate of contraction of the positive electrode potential measured at the BOL time point. As an example, It can be 1, but is not limited to this. This can represent the rate of contraction of the cathode potential estimated at the MOL time point. The rate of contraction of the cathode potential estimated at the MOL time point can be included in the parameters optimized by a specified algorithm.

[0104] [Equation 3]

[0105] Referring to Equation 3, LLI can represent the capacity loss of lithium contained in a single battery cell. It can represent the offset of the negative electrode potential estimated at the MOL time point. It can represent the offset of the positive electrode potential estimated at the MOL time point. It can represent the offset of the negative electrode potential obtained at the BOL time point. It can represent the offset of the positive potential obtained at the BOL time point.

[0106] For example, and It can be included in the parameters optimized by the specified algorithm. and It can be included in the battery data in BOL state.

[0107] At least one processor 205 of the battery diagnostic device 201 according to an embodiment can use LAMn, LAMp, and / or LLI to diagnose the state of a single battery cell. For example, at least one processor 205 of the battery diagnostic device 201 can provide diagnostic results of the state of the single battery cell. For example, at least one processor 205 of the battery diagnostic device 201 can provide diagnostic results to a user by transmitting the diagnostic results to an external electronic device (e.g., a server). However, this is not the only limitation.

[0108] Figure 6 Examples of degradation indicators in battery diagnostic devices and battery diagnostic methods according to embodiments of this document are illustrated.

[0109] refer to Figure 6 The first graph 601 may include points 603 representing the relationship between experimentally acquired LAM (e.g., LAMn2) of the negative electrode and LAM (e.g., LAMn1) of the negative electrode identified by an optimization algorithm, and a first line 605 representing the regression equation based on points 603.

[0110] The second graph 611 may include points 613 representing the relationship between the experimentally obtained LAM (e.g., LAMp2) of the positive electrode and the LAM (e.g., LAMp1) of the positive electrode identified by an optimization algorithm, and a second line 615 representing the regression equation based on points 613.

[0111] The third graph 621 may include a point 623 representing the relationship between the experimentally obtained LLI (e.g., LLI2) of the positive electrode and the LLI (e.g., LLI1) of the positive electrode identified by an optimization algorithm, and a third line 625 representing the regression equation based on point 623.

[0112] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can correct the LAM of the negative electrode plate identified by the optimization algorithm to the final LAM (e.g., the first LAM) of the negative electrode plate based on a preset relational expression identified according to the first line 605.

[0113] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can correct the LAM of the positive plate identified by the optimization algorithm to the final LAM of the positive plate (e.g., the second LAM) based on a preset relational expression identified according to the second line 615.

[0114] According to an embodiment, at least one processor 205 of the battery diagnostic device 201 can correct the final LLI of the LLI identified by the optimization algorithm to the negative plate based on the relational formula identified according to the third line 625.

[0115] Figure 7 The illustration shows an example of the operation flow of a battery diagnostic device that diagnoses the condition of a single battery cell based on degradation indicators in the battery diagnostic device, according to embodiments of this document.

[0116] In the following text, it is assumed that... Figure 2 Battery diagnostic equipment 201 Figure 7 The process. Furthermore, in Figure 7 In the description, the operations described as being performed by the battery diagnostic equipment can be understood as being performed by... Figure 2 At least one processor 205 of the battery diagnostic device 201 performs the operation.

[0117] refer to Figure 7 In the first operation 701, at least one processor 205 of the battery diagnostic device 201 according to the embodiment can obtain the open-circuit voltage of each first SOC based on at least one of the charging data of the battery cell, the discharging data of the battery cell, or a combination thereof, according to the SOC representing the amount of charge charged in the battery cell.

[0118] In the second operation 703, at least one processor 205 of the battery diagnostic device 201 according to the embodiment can obtain degradation indicators based on the open-circuit voltage of each first SOC.

[0119] In the third operation 705, at least one processor 205 of the battery diagnostic device 201 according to the embodiment can diagnose the state of a single battery cell based on degradation indicators.

[0120] Figure 8 This is a block diagram illustrating the hardware configuration of the computing system executing the battery diagnostic method in a battery diagnostic device and battery diagnostic method according to embodiments of this document.

[0121] refer to Figure 8The computing system 800 according to the embodiments disclosed in this document may include an MCU 810, a memory 820, an input / output I / F 830, and a communication I / F 840.

[0122] The MCU 810 can be one or more processors that execute various programs stored in the memory 1220 (e.g., battery cell data collection programs, graph generation programs, data analysis programs, data decomposition algorithms, normalization programs, and battery cell diagnostic programs, etc.). These programs process various information, including battery cell characteristic data and potential variables, and execute the aforementioned... Figures 2 to 5 The battery diagnostic device 201 shown has the following functions.

[0123] The memory 820 can store various programs, such as battery cell data acquisition programs, curve generation programs, data analysis programs, data decomposition algorithms, normalization programs, and battery cell diagnostic programs.

[0124] Multiple such memories 820 can be provided as needed. Memory 820 can be volatile or non-volatile memory. Memory 820 used as volatile memory can be RAM, DRAM, SRAM, etc. Memory 820 used as non-volatile memory can be ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc. The examples of memory 820 listed above are merely examples, but are not limited to these examples.

[0125] The Input / Output I / F 830 can provide an interface that allows data to be sent and received by connecting input devices (not shown) such as a keyboard, mouse, or touch panel and output devices (not shown) such as a display with an MCU 810.

[0126] The Communication I / F 840 is configured to send and receive various data with a server and can be various devices that support wired or wireless communication. For example, the battery diagnostic device 201 can send and receive various information, including the shape model of a battery cell, to and from a separately provided external server via the Communication I / F 840.

[0127] In this way, a computer program according to the embodiments disclosed in this document can be implemented to execute, for example, by being recorded in memory 820 and processed by MCU 810. Figure 2 The module for each function shown.

[0128] Even though all components constituting the embodiments disclosed in this document have been described as being combined as one or operating in combination, the embodiments disclosed in this document are not necessarily limited to such embodiments. That is, within the scope of the embodiments disclosed in this document, all components may be selectively combined and operated in one or more combinations.

[0129] Furthermore, the terms "comprising," "configuration," or "having," unless specifically stated otherwise, mean that they may include the corresponding components and should therefore be interpreted as capable of further including rather than excluding other components. Unless otherwise defined, all terms including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments disclosed in this document pertain. Commonly used terms, such as those defined in dictionaries, should be interpreted as consistent with the meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless clearly defined in this document.

[0130] The foregoing disclosure outlines features of several embodiments, enabling those skilled in the art to better understand various aspects of this disclosure. Those skilled in the art will understand that this disclosure can readily serve as a basis for designing or modifying different structures to perform the same purpose or achieve the same advantages of the embodiments described in this document. Furthermore, those skilled in the art will recognize that such equivalent configurations do not depart from the scope of this disclosure, and that various changes, substitutions, and modifications can be made in this specification without departing from the scope of this disclosure.

Claims

1. A battery diagnostic device, comprising: A memory configured to store at least one instruction; as well as At least one processor, the at least one processor being configured to execute the at least one instruction; Wherein, the at least one processor is configured to: Based on at least one of the charging data of the battery cell, the discharging data of the battery cell, or any combination thereof, the open-circuit voltage (OCV) of each first charge amount is obtained according to the charge amount indicating the amount of charge charged in the battery cell. The degradation index is obtained based on the open-circuit voltage of each first charge; and The condition of the battery cell is diagnosed based on the aforementioned degradation indicators.

2. The battery diagnostic device according to claim 1, wherein, The at least one processor is configured to: The open-circuit voltage corresponding to the charge amount is identified based on the following: a) a first voltage value of the battery cell corresponding to the charge amount and included in the charging data; b) a first current value of the battery cell corresponding to the charge amount and included in the charging data; c) a second voltage value of the battery cell corresponding to the charge amount and included in the discharging data; and d) a second current value of the battery cell corresponding to the charge amount and included in the discharging data. and The open-circuit voltage of each first charge is identified based on the charge amount and the open-circuit voltage.

3. The battery diagnostic device according to claim 2, wherein, The at least one processor is configured to: Based on a linear equation identified according to the relationship between the first current value and the first voltage value, and the relationship between the second current value and the second voltage value, when the current value of the battery cell is less than a specified current value, the voltage value of the battery cell corresponding to the current value of the battery cell is identified; and The open-circuit voltage corresponding to the charge amount is identified based on the voltage value of the individual battery cells.

4. The battery diagnostic device according to claim 1, wherein, The at least one processor is configured to: The parameters are obtained based on at least one of the following: i) an optimization algorithm, ii) the open-circuit voltage of each charge of the battery cell in the mid-life (MOL) state indicated by the open-circuit voltage of each first charge, iii) the open-circuit voltage of each third charge of the battery cell in the beginning-life (BOL) state, iv) the open-circuit potential (OCP) of each charge of the battery cell in the beginning-life state, or v) any combination thereof; and The degradation index is obtained based on the parameters.

5. The battery diagnostic device according to claim 4, wherein, The at least one processor is configured to execute the optimization algorithm using a genetic algorithm (GA).

6. The battery diagnostic device according to claim 1, wherein, The at least one processor is configured to acquire at least one of the charging data, the discharging data, or any combination thereof based on charging and discharging curves, wherein the battery cell is charged a specific number of times at a current value higher than a reference current, from a lower limit charge value higher than a first reference charge value to an upper limit charge value lower than a second reference charge value, the specific number of times being less than the reference number, and the battery cell is discharged a specific number of times at a current value, from the upper limit charge value to the lower limit charge value.

7. The battery diagnostic device according to claim 1, wherein, The degradation indicators include: Lithium inventory loss (LLI), which includes a first parameter related to the lithium loss of the battery cell at the middle of its life (MOL) compared to the start of life (BOL); First active material loss (LAM), the first active material loss including a second parameter related to the loss of active material in the negative plate of a battery cell at the middle of its lifespan, compared to the start of the lifespan; or The second active material loss (LAM) includes a third parameter related to the loss of active material in the positive plate of the battery cell at the middle of the lifetime, compared to the start of the lifetime.

8. A battery diagnostic method, comprising: Based on at least one of the charging data of the battery cell, the discharging data of the battery cell, or any combination thereof, the operation of obtaining the open circuit voltage (OCV) of each first charge amount according to the charge amount indicating the amount of charge charged in the battery cell. The operation of obtaining degradation indicators based on the open-circuit voltage of each first charge quantity; as well as The operation of diagnosing the condition of the battery cell based on the aforementioned degradation index.

9. The battery diagnostic method according to claim 8, wherein, The operation of obtaining the open-circuit voltage (OCV) of each first charge amount based on at least one of the charging data of the battery cell, the discharging data of the battery cell, or any combination thereof, according to the charge amount indicating the amount of charge charged in the battery cell, includes: The operation of identifying the open-circuit voltage corresponding to the charge amount is based on the following: a) a first voltage value of the battery cell corresponding to the charge amount and included in the charging data; b) a first current value of the battery cell corresponding to the charge amount and included in the charging data; c) a second voltage value of the battery cell corresponding to the charge amount and included in the discharging data; and d) a second current value of the battery cell corresponding to the charge amount and included in the discharging data; and The operation of identifying the open-circuit voltage of each first charge based on the charge amount and the open-circuit voltage.

10. The battery diagnostic method according to claim 9, wherein, The operation of identifying the open-circuit voltage corresponding to the charge amount is based on the following: a) a first voltage value of the battery cell corresponding to the charge amount and included in the charging data, b) a first current value of the battery cell corresponding to the charge amount and included in the charging data, c) a second voltage value of the battery cell corresponding to the charge amount and included in the discharging data, and d) a second current value of the battery cell corresponding to the charge amount and included in the discharging data, including: Based on a linear equation identified according to the relationship between the first current value and the first voltage value, and the relationship between the second current value and the second voltage value, the operation of identifying the voltage value of the battery cell corresponding to the current value of the battery cell when the current value of the battery cell is less than a specified current value; and The operation of identifying the open-circuit voltage corresponding to the charge amount based on the voltage value of the individual battery cells.

11. The battery diagnostic method according to claim 8, wherein, The operation of obtaining the degradation index based on the open-circuit voltage of each first charge quantity includes: The operation of obtaining parameters is based on at least one of the following: i) an optimization algorithm, ii) the open-circuit voltage of each charge of the battery cell in the mid-life (MOL) state indicated by the open-circuit voltage of each first charge, iii) the open-circuit voltage of each third charge of the battery cell in the beginning-life (BOL) state, iv) the open-circuit potential (OCP) of each charge of the battery cell in the beginning-life state, or v) any combination thereof; and The operation of obtaining the degradation index based on the parameters.

12. The battery diagnostic method according to claim 11, wherein, Operations that obtain parameters based on at least one of the following: i) an optimization algorithm, ii) the open-circuit voltage of each charge of the battery cell in the intermediate lifetime (MOL) state indicated by the open-circuit voltage of each first charge, iii) the open-circuit voltage of each third charge of the battery cell in the beginning lifetime state, iv) the open-circuit potential (OCP) of each charge of the battery cell in the beginning lifetime state, or v) any combination thereof including: operations that execute the optimization algorithm using a genetic algorithm (GA).

13. The battery diagnostic method according to claim 8, further comprising: The operation of charging the battery cell a specific number of times with a current value higher than the reference current, from a lower limit charge value higher than the first reference charge value to an upper limit charge value lower than the second reference charge value, wherein the specific number of times is less than the reference number; as well as Based on the charging and discharging curves, at least one of the charging data, the discharging data, or any combination thereof is obtained. Through the charging and discharging curves, the battery cell is discharged a specific number of times from the upper limit charge to the lower limit charge with a current value.

14. The battery diagnostic method according to claim 8, wherein the degradation indicators include: Lithium inventory loss (LLI), which includes a first parameter related to the lithium loss of the battery cell at the middle of its life (MOL) compared to the start of life (BOL); First active material loss (LAM), which includes a second parameter related to the loss of active material in the negative plate of a battery cell at the middle of its lifespan, compared to the start of the lifespan; or The second active material loss (LAM) includes a third parameter related to the loss of active material in the positive plate of the battery cell at the middle of the lifetime, compared to the start of the lifetime.

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