Battery diagnosis apparatus and battery diagnosis method

Abstract

A battery diagnosis apparatus, according to one embodiment disclosed in the present document, comprises: an interface for acquiring a temperature profile (dT / dV) indicating a temperature change of a battery cell with respect to a voltage change of the battery cell; and at least one processor, wherein the at least one processor is configured to identify at least one voltage section in the temperature profile, identify a first deviation value in the at least one voltage section, and diagnose a state of the battery cell on the basis of the first deviation value.

Description

Battery diagnostic device and battery diagnostic method

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0141242 filed on October 16, 2024, and includes all contents disclosed in the document of said Korean patent application as part of this specification.

[0003] Technology field

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

[0005] High-Ni battery cells are a type of cathode material primarily used in lithium-ion batteries and refer to battery cells containing ternary materials with a high nickel (Ni) content (e.g., NCM, Lithium Nickel Cobalt Manganese Oxide). High-Ni battery cells may contain cathode materials with a nickel content of 80% or more. High-Ni battery cells are used to increase energy density and can be utilized in large-capacity energy storage devices such as electric vehicles. As the nickel content increases, the stability of the battery may decrease. In particular, high-Ni battery cells exhibit reduced chemical stability at high temperatures, which can lead to problems such as thermal runaway. Therefore, there is a need to research technologies for diagnosing the condition of the battery by utilizing temperature changes.

[0006] One objective of the embodiments disclosed in this document is to provide a battery diagnostic device and a battery diagnostic method for identifying the degree of degradation of a material within a battery cell.

[0007] One objective of the embodiments disclosed in this document is to provide a battery diagnostic device and a battery diagnostic method for identifying the degree of degradation of a battery cell using a temperature profile.

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

[0009] A battery diagnostic device according to one embodiment disclosed in this document includes an interface for obtaining a temperature profile (dT / dV) representing a temperature change of a battery cell with respect to a voltage change of a battery cell; and at least one processor, wherein the at least one processor may be configured to identify at least one voltage interval in the temperature profile, identify a first deviation value in the at least one voltage interval, and diagnose the state of the battery cell based on the first deviation value.

[0010] For example, the above at least one processor may be configured to identify a reference temperature profile associated with the battery cell in the BOL (beginning of life) state, identify a reference voltage range corresponding to the at least one voltage range in the reference temperature profile, identify a second deviation value in the reference voltage range, and diagnose the state of the battery cell using the first deviation value and the second deviation value.

[0011] For example, the at least one processor may be configured to identify the first deviation value using the first maximum value and the first minimum value identified in the at least one voltage interval of the temperature profile, and to identify the second deviation value using the second maximum value and the second minimum value identified in the reference voltage interval.

[0012] For example, the above at least one processor may be configured to diagnose that degradation has occurred in the positive electrode of the battery cell when the value obtained by dividing the first deviation value by the second deviation value is less than a threshold.

[0013] For example, the above at least one processor may be configured to change the charging upper voltage of the battery cell when it is diagnosed that degradation has occurred in the positive electrode of the battery cell.

[0014] For example, the at least one processor may be configured to identify a temperature increase section in which the temperature of the battery cell increases in the temperature profile, and to identify the at least one voltage section using the temperature increase section.

[0015] For example, the at least one processor may be configured to identify a plurality of voltage intervals in the temperature profile and to identify the at least one voltage interval corresponding to a state of charge (SOC) that exceeds a specified state of charge (SOC) among the plurality of voltage intervals.

[0016] For example, the at least one processor may be configured to identify the first deviation value generated by the positive electrode among the positive and negative electrodes included in the battery cell.

[0017] A battery diagnostic method according to one embodiment disclosed in this document may include the operation of identifying at least one voltage interval in a temperature profile (dT / dV) representing a temperature change of a battery cell relative to a voltage change of a battery cell, the operation of identifying a first deviation value in the at least one voltage interval, and the operation of diagnosing the state of the battery cell based on the first deviation value.

[0018] For example, the operation of diagnosing the state of the battery cell may include the operation of identifying a reference temperature profile associated with the battery cell in the BOL (beginning of life) state, the operation of identifying a reference voltage range corresponding to at least one voltage range in the reference temperature profile, the operation of identifying a second deviation value in the reference voltage range, and the operation of diagnosing the state of the battery cell using the first deviation value and the second deviation value.

[0019] For example, the operation of identifying the first deviation value may include the operation of identifying the first deviation value using the first maximum value and the first minimum value identified in the at least one voltage interval of the temperature profile, and the operation of identifying the second deviation value may include the operation of identifying the second deviation value using the second maximum value and the second minimum value identified in the reference voltage interval.

[0020] For example, the operation of diagnosing the condition of the battery cell may include diagnosing that degradation has occurred in the positive electrode of the battery cell when the value obtained by dividing the first deviation value by the second deviation value is less than a threshold value.

[0021] For example, the operation of diagnosing that degradation has occurred in the positive electrode of the battery cell may further include the operation of changing the upper charging voltage of the battery cell when it is diagnosed that degradation has occurred in the positive electrode of the battery cell.

[0022] For example, the operation of identifying the at least one voltage range may include, in the temperature profile, the operation of identifying a temperature increase range in which the temperature of the battery cell increases, and the operation of identifying the at least one voltage range using the temperature increase range.

[0023] For example, the operation of identifying at least one voltage interval may include the operation of identifying a plurality of voltage intervals in the temperature profile, and the operation of identifying the at least one voltage interval corresponding to a state of charge (SOC) exceeding a specified state of charge (SOC) among the plurality of voltage intervals.

[0024] The battery diagnostic device and battery diagnostic method disclosed in this document can identify the degree of degradation of materials within a battery cell.

[0025] The battery diagnostic device and battery diagnostic method disclosed in this document can identify the degree of degradation of a battery cell using a temperature profile.

[0026] In addition, various effects that can be identified directly or indirectly through this document may be provided.

[0027] FIG. 1 is a block diagram showing a battery pack according to one embodiment disclosed in this document.

[0028] FIG. 2 is a block diagram showing the configuration of a battery diagnostic device according to one embodiment disclosed in this document.

[0029] FIG. 3 illustrates an example of a graph showing data related to a battery cell obtained by a battery diagnostic device according to an embodiment disclosed in this document.

[0030] FIG. 4 illustrates an example of a graph showing a temperature profile obtained by a battery diagnostic device according to an embodiment disclosed in this document.

[0031] FIGS. 5A and 5B illustrate an example of a graph showing a temperature profile according to the use of a battery cell according to an embodiment disclosed in this document.

[0032] FIG. 6 illustrates an example of a flowchart showing the operation performed by a battery diagnostic device according to an embodiment disclosed in this document.

[0033] FIG. 7 shows a computing system that executes a battery diagnostic method according to one embodiment disclosed in this document.

[0034] Some embodiments disclosed herein are described below with reference to the various embodiments of the accompanying drawings. However, this is not intended to limit the technology to specific embodiments and should be understood to include various modifications, equivalents, and / or alternatives to embodiments of the technology.

[0035] It should be noted that when assigning reference numerals to the components of each drawing, the same components are assigned the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the various embodiments disclosed in this document, if it is determined that a detailed description of related known configurations or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted. The singular form of a noun corresponding to an item may include one or more items unless the relevant context clearly indicates otherwise.

[0036] In describing the components of the embodiments of this document, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are intended merely to distinguish the components from other components and do not limit the essence, order, or sequence of the components. Furthermore, unless otherwise defined, all terms used herein, 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. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0037] Additionally, in this disclosure, expressions of "greater than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled; however, this is merely for the purpose of expressing an example and does not exclude descriptions of "greater than" or "less than." Conditions described as "greater than" may be replaced with "greater than," conditions described as "less than" may be replaced with "less than," and conditions described as "greater than and less than" may be replaced with "greater than and less than." Furthermore, "A" to "B" below refer to at least one of the elements from A (including A) to B (including B).

[0038] 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.

[0039] 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., via a wire), wirelessly, or through a third component.

[0040] The term “module” as used in the various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit, for example. A module may be a component formed integrally, or a minimum unit of said component or a part thereof that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC).

[0041] Various embodiments of this document may be implemented as software (e.g., a program) comprising one or more instructions stored on a storage medium readable by a machine. For example, the processor of the machine may call at least one of the one or more instructions stored from the storage medium and execute it. This enables the machine to operate to perform at least one function according to the at least one called instruction. The one or more instructions may include code generated by a compiler or code that can be executed by an interpreter. The storage medium readable by a machine may be provided in the form of a non-transitory storage medium. Here, "non-transitory" simply means that the storage medium is a tangible device and does not contain a signal, and this term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily in the storage medium.

[0042] According to one embodiment, the method according to the various embodiments disclosed herein may be provided as included in 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 user 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.

[0043] According to various embodiments, each component (e.g., module or program) of the described components may include a singular or multiple entities, and some of the multiple entities may be separated and placed in other components. According to various embodiments, one or more of the aforementioned components or operations 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 this case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as they were performed by the corresponding component among the multiple components prior to integration.

[0044] According to various embodiments, 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.

[0045]

[0046] FIG. 1 is a block diagram showing a battery pack according to one embodiment disclosed in this document.

[0047] Referring to FIG. 1, a battery control system including a battery pack (1) and a higher controller (2) included in a higher system according to one embodiment disclosed in this document is schematically shown.

[0048] As illustrated in FIG. 1, the battery pack (1) may include a plurality of battery cells (11) (or one or more battery cells), a switching unit (14) connected in series to the first terminal side and / or second terminal side of the plurality of battery cells (11) to control the charge / discharge current flow of the plurality of battery cells (11), and a battery management system (20) that monitors the voltage, current, temperature, etc. of the battery pack (1) to prevent overcharging and over-discharging.

[0049] For example, at least one of the plurality of battery cells (11) may include an electrode (e.g., a positive electrode) comprising a High-Ni (high contents Ni) NCM (Lithium Nickel Cobalt Manganese Oxide) material.

[0050] In this case, the battery pack (1) may be equipped with a plurality of battery cells (11), a sensor (12), a switching unit (14), and / or a battery management system (20). For example, the first terminal may be the (+) terminal of the plurality of battery cells (11), and the second terminal may be the (-) terminal.

[0051] Here, the switching unit (14) is a device for controlling the current flow for charging or discharging a plurality of battery cells (11), and, for example, depending on the specifications of the battery pack (1), at least one relay, magnetic contactor, etc. may be used.

[0052] For example, a plurality of battery cells (11) may include a cylindrical battery. A cylindrical battery refers to a battery in which the battery material is packaged into a cylinder.

[0053] The battery management system (20) is an interface that receives values ​​of various parameters measured above, and may include a plurality of terminals and a circuit connected to these terminals to perform processing of the received values. Additionally, the battery management system (20) may control the ON / OFF of a switching unit (14), such as a relay or contactor, and may be connected to a battery cell (11) to monitor the status of each of the plurality of battery cells (11).

[0054] The upper controller (2) can transmit control signals for a plurality of battery cells (11) to the battery management system (20). Accordingly, the operation of the battery management system (20) can be controlled based on the signals applied from the upper controller (2).

[0055] According to an embodiment, the battery management system (20) may include the battery diagnostic device (100) of FIG. 2. According to another embodiment, the battery management system (20) may be a different system from the battery diagnostic device (100) of FIG. 2. That is, the battery diagnostic device (100) of FIG. 2 may be included in the battery pack (1) or may be composed of another device outside the battery pack (1). For convenience of explanation, the description is based on the premise that the battery diagnostic device (100) is composed of another device outside the battery pack (1).

[0056] FIG. 2 is a block diagram showing the configuration of a battery diagnostic device according to one embodiment disclosed in this document.

[0057] Referring to FIG. 2, a battery diagnostic device (100) according to one embodiment may include at least one of a processor (110), a memory (120), or an interface (130). The processor (110), the memory (120), and the interface (130) may be electrically and / or operably coupled with each other by an electronic component including a communication bus. Hereinafter, operably coupled hardware may mean that a direct connection or an indirect connection between the hardware is established via wired or wireless means so that a second hardware is controlled by a first hardware among the hardware. Although illustrated based on different blocks, the embodiment is not limited thereto, and some of the hardware of FIG. 2 (e.g., at least a portion of the processor (110), the memory (120), and the communication circuit (not shown)) may be included in a single integrated circuit, such as a system on a chip (SoC). Communication methods between components may include buses, GPIO (general purpose input and output), SPI (serial peripheral interface), MIPI (mobile industry processor interface), etc.

[0058] A processor (110) of a battery diagnostic device (100) according to one embodiment may include a hardware component for processing data based on one or more instructions. The hardware component for processing data may include, for example, an arithmetic and logic unit (ALU), a floating point unit (FPU), a field programmable gate array (FPGA), a central processing unit (CPU), a microcontroller unit (MCU), and / or an application processor (AP). The number of processors (110) may be one or more. For example, the processor (110) may have the structure of a multi-core processor including a dual core, a quad core, a hexa core, or an octa core.

[0059] A memory (120) of a battery diagnostic device (100) according to one embodiment may include a hardware component for storing data and / or instructions that are input and / or output to a processor (110). The memory (120) may include, for example, volatile memory such as random-access memory (RAM) and / or non-volatile memory such as read-only memory (ROM). For example, the volatile memory may include at least one of dynamic RAM (DRAM), static RAM (SRAM), cache RAM, and pseudo SRAM (PSRAM). For example, the non-volatile memory may include at least one of programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), flash memory, hard disk, compact disk, and embedded multi-media card (eMMC). For example, the memory (120) may be configured to store a voltage profile representing a voltage change with respect to a change in capacity of a battery cell comprising an LMFP (lithium manganese iron phosphate) material and / or an NCM (nickel, cobalt, manganese) material. For example, the LMFP material and / or NCM material may be included in the electrodes of the battery cell.

[0060] An interface (130) of a battery diagnostic device (100) according to one embodiment may be configured to generate various battery measurement values ​​from the battery. To this end, the interface (130) may include a measurement means such as a voltmeter, ammeter, and thermometer, and a communication circuit for establishing a communication link with an external device. As an example, the interface (130) may include a temperature sensor attached to a battery cell.

[0061] A battery diagnostic device (100) according to one embodiment can obtain a temperature profile representing the relationship between the voltage of a battery cell and the temperature of a battery cell by using an interface (130). The temperature profile may represent the change in temperature of a battery cell with respect to the change in voltage of the battery cell. In other words, the temperature profile may include dT / dV data of the battery cell. In terms of including dT / dV data of the battery cell, the temperature profile may be referred to as a differential temperature profile.

[0062] A battery diagnostic device (100) according to one embodiment may include a capacity profile (e.g., dQ / dV data) that indicates the relationship between the capacity of a battery cell and the voltage of a battery cell using an interface (130). For example, the capacity profile may indicate a change in the capacity of a battery cell with respect to a change in the voltage of a battery cell.

[0063] A battery diagnostic device (100) according to one embodiment can identify at least one voltage range in a temperature profile.

[0064] In one embodiment, the battery diagnostic device (100) can identify a temperature increase section in the temperature profile where the temperature of the battery cell increases. For example, the battery diagnostic device (100) can identify at least one voltage section using the temperature increase section.

[0065] In one embodiment, the battery diagnostic device (100) can identify a plurality of voltage ranges in a temperature profile. For example, the battery diagnostic device (100) can identify at least one voltage range among the plurality of voltage ranges that corresponds to a state of charge (SOC) exceeding a specified state of charge (SOC).

[0066] A battery diagnostic device (100) according to one embodiment can identify a first deviation value in at least one voltage range.

[0067] In one embodiment, the battery diagnostic device (100) can identify a first maximum value and a first minimum value in at least one voltage interval of the temperature profile. For example, the battery diagnostic device (100) can identify a first deviation value using the first maximum value and the first minimum value identified in at least one voltage interval of the temperature profile. For example, the battery diagnostic device (100) can identify the difference between the first maximum value and the first minimum value as the first deviation value.

[0068] In one embodiment, the battery diagnostic device (100) can identify a first deviation value generated by the positive electrode among the positive electrode and the negative electrode included in the battery cell.

[0069] A battery diagnostic device (100) according to one embodiment can identify a reference temperature profile associated with a battery cell in the BOL (beginning of life) state. For example, the battery diagnostic device (100) can identify a reference voltage range corresponding to at least one voltage range in the reference temperature profile. For example, the battery diagnostic device (100) can identify a second deviation value in the reference voltage range.

[0070] In one embodiment, the battery diagnostic device (100) can identify a second maximum value and a second minimum value in a reference voltage range. For example, the battery diagnostic device (100) can identify (or obtain) a second deviation value using the second maximum value and the second minimum value identified in the reference voltage range. For example, the battery diagnostic device (100) can identify the difference between the second maximum value and the second minimum value as the second deviation value.

[0071] A battery diagnostic device (100) according to one embodiment can diagnose the condition of a battery cell based on a first deviation value. For example, if the battery diagnostic device (100) diagnoses the condition of the battery cell as abnormal, it can perform an operation to mitigate the degradation of the battery cell.

[0072] In one embodiment, the battery diagnostic device (100) can diagnose that degradation has occurred in the positive electrode of the battery cell when the value obtained by dividing the first deviation value by the second deviation value is less than a threshold value.

[0073] In one embodiment, the battery diagnostic device (100) may change the upper charging voltage of the battery cell when it diagnoses that degradation has occurred in the positive electrode of the battery cell. For example, the battery diagnostic device (100) may limit the upper charging voltage of the battery cell. For example, the upper charging voltage may represent the maximum voltage of the battery cell.

[0074] In one embodiment, when the battery diagnostic device (100) diagnoses that degradation has occurred in the positive electrode of the battery cell, it can change the charging speed for charging the battery cell (or the discharge speed at which the battery cell is discharged).

[0075] A battery diagnostic device (100) according to one embodiment as described above can determine the degree of degradation of a battery cell by using the temperature profile of the battery cell. By diagnosing the battery cell using the temperature profile of the battery cell, the battery diagnostic device (100) can improve the usability of the temperature profile of the battery cell.

[0076] FIG. 3 illustrates an example of a graph showing data related to a battery cell obtained by a battery diagnostic device according to an embodiment disclosed in this document. The battery diagnostic device (100) of FIG. 3 may be referenced to the battery diagnostic device (100) of FIG. 2.

[0077] The graph (300) of FIG. 3 may include a temperature profile (301) representing the relationship between the capacity of the battery cell and the temperature of the battery cell, and a voltage profile (302) representing the relationship between the capacity of the battery cell and the voltage of the battery cell.

[0078] Referring to the graph (300), the battery diagnostic device (100) according to one embodiment can identify the section where the temperature of the battery cell changes in the temperature profile (301).

[0079] For example, the battery diagnostic device (100) can identify a first temperature reduction section (307) caused by a phase transition of the negative electrode.

[0080] For example, the battery diagnostic device (100) can identify a temperature increase section (305) in which the temperature of the battery cell increases.

[0081] In one embodiment, the section after the temperature increase section (305) may include a second temperature decrease section (309) in which the temperature of the battery cell is reduced. The second temperature decrease section (309) may correspond to a constant voltage (CV) charging section of the battery cell.

[0082] In one embodiment, the temperature increase interval (305) may correspond to a state of charge (SOC) exceeding a specified state of charge (e.g., about 80%). For example, by using the temperature increase interval (305), the battery diagnostic device (100) can identify a phase transition of at least one material (e.g., High-Ni) within the battery cell.

[0083] In one embodiment, at least one phase transition may indicate a change from the H2 phase (Hexagonal 2 phase) to the H3 phase.

[0084] For example, the H2 phase can represent a specific layered structure of the cathode material. The H2 phase can represent a hexagonal structure. In the state having a hexagonal structure, the H2 phase can represent the arrangement of ions.

[0085] For example, the H3 phase may represent a state in which the layered structure corresponding to the H2 phase changes and transitions into a new form of hexagonal structure. The H3 phase may represent a relatively unstable state compared to the H2 phase. Since the H3 phase represents a relatively unstable state compared to the H2 phase, the degree of positive degradation of the battery cell can be identified based on the extent to which at least one phase of the material transitions from the H2 phase to the H3 phase.

[0086] For example, by referring to the temperature profile (301) and voltage profile (302), it can be seen that in the region corresponding to an SOC exceeding a specified SOC (e.g., the region exceeding 100 Ah in FIG. 3), the temperature of the battery cell increases due to a phase transition of at least one material within the battery cell.

[0087] A battery diagnostic device (100) according to an embodiment as described above can infer a phase transition of at least one material within a battery cell by using the temperature profile (301) of the battery cell. The battery diagnostic device (100) can diagnose the degree of degradation of the battery cell according to the degree of change in the phase transition.

[0088] FIG. 4 illustrates an example of a graph showing a temperature profile obtained by a battery diagnostic device according to an embodiment disclosed in this document. The battery diagnostic device (100) of FIG. 4 may be referenced to the battery diagnostic device (100) of FIG. 2.

[0089] Referring to FIG. 4, the graph (400) may include a capacity profile (402) representing a change in capacity with respect to a change in voltage of the battery cell. The graph (400) may include a temperature profile (401) representing a change in temperature with respect to a change in voltage of the battery cell. Referring to FIG. 4, the graph (400) may represent a relationship between a phase transition of at least one material within the battery cell and the temperature of the battery cell.

[0090] A battery diagnostic device (100) according to one embodiment can identify at least one voltage range (405) in a temperature profile (401).

[0091] In one embodiment, at least one voltage interval (405) may correspond to an SOC exceeding a specified SOC. At least one voltage interval (405) may be related to a change in the positive electrode among the positive and negative electrodes of the battery cell.

[0092] For example, the battery diagnostic device (100) can identify a temperature increase section (403) in which the temperature of the battery cell increases in the temperature profile (401). The temperature increase section (403) may correspond to the temperature increase section (305) of FIG. 3. For example, the battery diagnostic device (100) can identify at least one voltage section (405) using the temperature increase section (403).

[0093] In one embodiment, at least one voltage interval (405) may include a peak value (407) indicating a phase transition of the battery cell. For example, the peak value (407) may indicate that at least one material of the battery cell undergoes a phase transition from the H2 phase to the H3 phase. That is, the battery diagnostic device (100) can obtain the peak value (407) indicating a phase transition of the battery cell by identifying a temperature increase interval (403) using a temperature profile (401). The battery diagnostic device (100) can infer the degree of phase transition of the battery cell using the temperature values ​​included in the temperature increase interval (403). Hereinafter, with reference to FIGS. 5A and 5B, the operation of the battery diagnostic device (100) diagnosing the degree of positive degradation of the battery cell using a temperature profile (401) will be described in more detail.

[0094] FIGS. 5A and 5B illustrate an example of a graph showing a temperature profile according to the use of a battery cell according to an embodiment disclosed in this document. The battery diagnostic device (100) of FIGS. 5A and 5B may be referenced to the battery diagnostic device (100) of FIG. 2.

[0095] Referring to FIG. 5a, the graph (500) may include data related to a battery cell in the middle of life (MOL) state. A battery cell in the MOL state may be included in a state that is relatively degraded compared to a battery cell in the beginning of life (BOL) state.

[0096] For example, the graph (500) may include a temperature profile (501) representing a change in temperature with respect to a change in voltage of a battery cell in the MOL state. The graph (500) may include a capacity profile (501) representing a change in capacity with respect to a change in voltage of a battery cell in the MOL state.

[0097] A battery diagnostic device (100) according to one embodiment can identify a plurality of voltage intervals in a temperature profile (501). The battery diagnostic device (100) can identify at least one voltage interval (504) corresponding to a SOC that exceeds a specified SOC among the plurality of voltage intervals. The battery diagnostic device (100) can identify at least one voltage interval (504) corresponding to a voltage that exceeds a specified voltage (503) that corresponds to a specified SOC (e.g., about 80%).

[0098] A battery diagnostic device (100) according to one embodiment can identify a temperature reduction section (505). The temperature reduction section (505) may be referenced to the first temperature reduction section (307) of FIG. 3. The temperature reduction section (505) may be generated by a phase transition of the negative electrode of the battery cell.

[0099] A battery diagnostic device (100) according to one embodiment can identify a temperature increase section (510). The temperature increase section (510) may be referenced to the temperature increase section (305) of FIG. 3. The temperature increase section (510) may be generated by a phase transition of at least one material (or positive electrode) within the battery cell. The temperature increase section (510) may be generated by a change in the crystal structure corresponding to at least one material within the battery cell.

[0100] A battery diagnostic device (100) according to one embodiment can identify a first maximum value (511) and a first minimum value (506) in at least one voltage range (504).

[0101] For example, the first maximum value (511) may be included in the temperature increase section (510). The first minimum value (506) may be included in the temperature decrease section (505).

[0102] A battery diagnostic device (100) according to one embodiment can identify a first deviation value (515) using a first maximum value (511) and a first minimum value (506) identified in at least one voltage range (504). The first deviation value (515) may represent the difference between the first maximum value (511) and the first minimum value (505).

[0103] Referring to FIG. 5b, the graph (550) may include data related to the battery cell in the BOL state. The graph (550) may include a reference temperature profile (551) related to the battery cell in the BOL state. The graph (550) may include a reference capacity profile (552) related to the battery cell in the BOL state. For example, the reference temperature profile (551) may represent a temperature change with respect to a voltage change of the battery cell in the BOL state. The reference capacity profile may represent a capacity change with respect to a voltage change of the battery cell in the BOL state. However, it is not limited thereto.

[0104] A battery diagnostic device (100) according to one embodiment can identify a reference voltage section (554) corresponding to at least one voltage section (e.g., at least one voltage section (504) of FIG. 5a) in a reference temperature profile (551).

[0105] A battery diagnostic device (100) according to one embodiment can identify a plurality of voltage intervals in a reference temperature profile (551). The battery diagnostic device (100) can identify at least one voltage interval (554) corresponding to a SOC that exceeds a specified SOC among the plurality of voltage intervals. The battery diagnostic device (100) can identify at least one voltage interval (554) corresponding to a voltage that exceeds a specified voltage (553) that corresponds to a specified SOC (e.g., about 80%).

[0106] A battery diagnostic device (100) according to one embodiment can identify a temperature reduction section (555). The temperature reduction section (555) can be referenced to the first temperature reduction section (307) of FIG. 3.

[0107] A battery diagnostic device (100) according to one embodiment can identify a temperature increase section (560). The temperature increase section (560) can be referenced to the temperature increase section (305) of FIG. 3.

[0108] A battery diagnostic device (100) according to one embodiment can identify a second maximum value (561) and a first minimum value (556) in a reference voltage range (554). A battery diagnostic device (100) according to one embodiment can identify a second deviation value (565) in a reference voltage range (554).

[0109] For example, the battery diagnostic device (100) can identify a second deviation value (565) using a second maximum value (561) and a second minimum value (556). The second deviation value (565) may represent the difference between the second maximum value (561) and the second minimum value (556).

[0110] A battery diagnostic device (100) according to one embodiment can determine the degree of degradation of a battery cell using a first deviation value (515) and a second deviation value (565). The battery diagnostic device (100) can control the battery cell based on the first deviation value (515) and the second deviation value (565).

[0111] A battery diagnostic device (100) according to one embodiment can diagnose that degradation has occurred in the positive electrode of a battery cell when the value obtained by dividing the first deviation value (515) by the second deviation value (565) is less than a threshold value. The battery diagnostic device (100) can change the threshold value.

[0112] A battery diagnostic device (100) according to one embodiment may change the upper charging voltage of a battery cell when it diagnoses that degradation has occurred in the positive electrode of a battery cell. For example, the battery diagnostic device (100) may lower the upper charging voltage representing the maximum voltage at which the battery cell can be used.

[0113] In one embodiment, the battery diagnostic device (100) can change the discharge lower voltage of the battery cell. For example, the battery diagnostic device (100) can increase the discharge lower voltage representing the usable minimum voltage of the battery cell.

[0114] A battery diagnostic device (100) according to an embodiment as described above can diagnose the condition of a battery cell using a reference temperature profile (551) and a temperature profile (501). The battery diagnostic device (100) can determine the degree of phase transition of the positive electrode using the temperature profile (501). By determining the degree of phase transition of the positive electrode, the battery diagnostic device (100) can diagnose the condition of the battery cell. If the battery diagnostic device (100) diagnoses the condition of the battery cell as abnormal, it can lower the charging upper voltage of the battery cell. The battery diagnostic device (100) can qualitatively determine the degree of degradation of at least one material of the battery cell using the temperature profile (501). By diagnosing the condition of the battery cell using the temperature profile (501), the battery diagnostic device (100) can improve the usability of the temperature profile (501).

[0115] FIG. 6 illustrates an example of a flowchart showing operations performed by a battery diagnostic device according to an embodiment disclosed in this document. Hereinafter, it is assumed that the battery diagnostic device (100) of FIG. 2 performs the process of FIG. 6. Furthermore, the operations described as being performed by the device can be understood as being controlled by the processor (110) of the battery diagnostic device (100). Each of the operations of FIG. 6 may be performed sequentially, but is not necessarily performed sequentially. For example, the order of each of the operations may be changed, and at least two operations may be performed in parallel. In addition, the operation of the battery diagnostic device (100) may be performed by a Battery Management System (BMS) in a vehicle, as well as by various devices such as a server, cloud, charger, or charge / discharger.

[0116] In operation S610, a battery diagnostic device according to one embodiment can identify at least one voltage interval (e.g., at least one voltage interval (504) of FIG. 5a) in a temperature profile (e.g., temperature profile (501) of FIG. 5a). For example, the battery diagnostic device (100) can identify at least one voltage interval corresponding to an SOC that exceeds a specified SOC. The region corresponding to an SOC that exceeds a specified SOC may represent a region where the temperature changes due to a phase transition of the positive electrode of the battery cell.

[0117] In operation S620, a battery diagnostic device according to one embodiment can identify a first deviation value in at least one voltage range. For example, the battery diagnostic device can identify a first minimum value (e.g., the first minimum value (506) in FIG. 5A) in a temperature decrease range (e.g., the temperature decrease range (505) in FIG. 5A) where the temperature is reduced due to a phase transition of the negative electrode of the battery cell. For example, the battery diagnostic device can identify a first maximum value (e.g., the first maximum value (511) in FIG. 5A) in a temperature increase range (e.g., the temperature increase range (510) in FIG. 5A) where the temperature is increased due to a phase transition of the positive electrode of the battery cell.

[0118] For example, a battery diagnostic device can obtain a first deviation value using a first maximum value and a first minimum value.

[0119] In operation S630, a battery diagnostic device according to one embodiment can diagnose the condition of a battery cell based on a first deviation value.

[0120] For example, a battery diagnostic device can obtain a second deviation value (e.g., a second deviation value (565) in FIG. 5b) using a reference temperature profile associated with a battery cell in BOL state (e.g., the reference temperature profile (551) in FIG. 5b).

[0121] For example, a battery diagnostic device can diagnose the condition of a battery cell using the difference between a first deviation value and a second deviation value. For example, a battery diagnostic device can diagnose the condition of a battery cell based on the ratio of the first deviation value to the second deviation value.

[0122] For example, a battery diagnostic device may diagnose that degradation has occurred in the positive electrode of a battery cell if the value obtained by dividing a first deviation value by a second deviation value falls below a threshold. For example, the occurrence of degradation in the positive electrode of a battery cell may include cases where the degree of degradation of the positive electrode of the battery cell exceeds a specified degree of degradation. In other words, the battery diagnostic device may diagnose that the degree of degradation of the positive electrode of the battery cell exceeds a specified degree of degradation if the value obtained by dividing a first deviation value by a second deviation value falls below a threshold.

[0123] For example, if a battery diagnostic device diagnoses that degradation has occurred in the positive electrode of a battery cell, it may change the upper charging voltage of the battery cell to mitigate (or slow down) the degradation of the battery cell. However, it is not limited to this.

[0124] FIG. 7 shows a computing system that executes a battery diagnostic method according to one embodiment disclosed in this document.

[0125] Referring to FIG. 7, a computing system (1000) according to one embodiment disclosed in this document may include an MCU (1010), a memory (1020), an input / output I / F (1030), and a communication I / F (1040).

[0126] The MCU (1010) may be a processor that executes various programs stored in memory (1020) (e.g., SOH calculation program, cell balancing target determination program, etc.), processes various data including SOC (state of charge), SOH (state of health), etc. of multiple battery cells through these programs, and performs the functions of the battery diagnostic device (100) described above. The MCU (1010) may be a BMS, a separate PC, or a cloud, but is not limited thereto.

[0127] The memory (1020) can store various programs regarding the calculation of the battery cell's SOH and the determination of the target for cell balancing. Additionally, the memory (1020) can store various data such as SOC data and SOH data for each battery cell.

[0128] These memories (1020) may be provided in multiple quantities as needed. The memories (1020) may be volatile memories or non-volatile memories. As volatile memories, the memory (1020) may use RAM, DRAM, SRAM, etc. As non-volatile memories, the memory (1020) may use ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc. The examples of the memories (1020) listed above are merely examples and are not limited to these examples.

[0129] The input / output I / F (1030) can provide an interface that enables data transmission and reception between an input device (not shown), such as a keyboard, mouse, or touch panel, an output device (not shown), and an MCU (1010).

[0130] The communication I / F (1040) is configured to transmit and receive various data to and from a server and may be various devices capable of supporting wired or wireless communication. For example, through the communication I / F (1040), programs for calculating the SOH of a battery cell or determining a balancing target, or various data, can be transmitted and received from an external server provided separately.

[0131] As such, a battery diagnostic method according to one embodiment disclosed in this document can be recorded in memory (1020) and executed by an MCU (1010).

[0132] As described above, even though all components constituting the embodiments disclosed in this document have been described as being combined or operating in combination, the embodiments disclosed in this document are not necessarily limited to such embodiments. That is, within the scope of the purposes of the embodiments disclosed in this document, all components may be selectively combined in one or more ways to operate.

[0133] Furthermore, terms such as "include," "compose," or "have" as described above, unless specifically stated otherwise, mean that the relevant component may be inherent; thus, 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 contextual meanings in the relevant technology and, unless explicitly defined in this document, should not be interpreted in an ideal or overly formal sense.

[0134] The above 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 belong may 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 for obtaining a temperature profile (dT / dV) representing a temperature change of the battery cell with respect to a voltage change of the battery cell; and It includes at least one processor, The above-mentioned at least one processor is, Identify at least one voltage interval in the above temperature profile, and Identifying a first deviation value in at least one voltage interval above, and Configured to diagnose the state of the battery cell based on the above first deviation value, Battery diagnostic device.

2. In Paragraph 1, The above-mentioned at least one processor is, Identify a reference temperature profile associated with the battery cell in the BOL (beginning of life) state, and Identifying a reference voltage interval corresponding to at least one voltage interval in the above reference temperature profile, and Identifying a second deviation value in the above reference voltage range, Configured to diagnose the state of the battery cell using the first deviation value and the second deviation value. Battery diagnostic device.

3. In Paragraph 2, The above-mentioned at least one processor is, Identifying the first deviation value using the first maximum value and the first minimum value identified in the at least one voltage interval of the temperature profile, and Configured to identify the second deviation value using the second maximum value and the second minimum value identified in the above reference voltage range, Battery diagnostic device.

4. In Paragraph 2, The above-mentioned at least one processor is, A configuration configured to diagnose that degradation has occurred in the positive electrode of the battery cell when the value obtained by dividing the first deviation value by the second deviation value falls below a threshold value. Battery diagnostic device.

5. In Paragraph 4, The above-mentioned at least one processor is, When it is diagnosed that degradation has occurred in the positive electrode of the battery cell, the above battery cell is configured to change the upper charging voltage of the battery cell, Battery diagnostic device.

6. In Paragraph 1, The above-mentioned at least one processor is, In the above temperature profile, identify the temperature increase section where the temperature of the battery cell increases, and Configured to identify the at least one voltage section using the above temperature increase section, Battery diagnostic device.

7. In Paragraph 1, The above-mentioned at least one processor is, Identifying multiple voltage intervals in the above temperature profile, and Configured to identify at least one voltage interval corresponding to a state of charge (SOC) exceeding a designated state of charge (SOC) among the plurality of voltage intervals. Battery diagnostic device.

8. In Paragraph 1, The above-mentioned at least one processor is, A configuration for identifying the first deviation value generated by the positive electrode among the positive and negative electrodes included in the battery cell, Battery diagnostic device.

9. An operation of identifying at least one voltage interval in a temperature profile (dT / dV) representing a temperature change of the battery cell with respect to a voltage change of the battery cell, The operation of identifying a first deviation value in at least one voltage interval, and A method including an operation to diagnose the state of the battery cell based on the first deviation value. Battery diagnostic method.

10. In Paragraph 9, The operation of diagnosing the condition of the above battery cell is, An operation to identify a reference temperature profile associated with the battery cell in the BOL (beginning of life) state, The operation of identifying a reference voltage interval corresponding to at least one voltage interval in the above reference temperature profile, An operation to identify a second deviation value in the above reference voltage range, and A method comprising diagnosing the state of the battery cell using the first deviation value and the second deviation value. Battery diagnostic method.

11. In Paragraph 10, The operation of identifying the above first deviation value is, The operation of identifying the first deviation value using the first maximum value and the first minimum value identified in the at least one voltage interval of the temperature profile, and The operation of identifying the above second deviation value is, The method includes an operation of identifying the second deviation value using the second maximum value and the second minimum value identified in the reference voltage range. Battery diagnostic method.

12. In Paragraph 10, The operation of diagnosing the condition of the above battery cell is, A method comprising diagnosing that degradation has occurred in the positive electrode of the battery cell when the value obtained by dividing the first deviation value by the second deviation value is less than a threshold value. Battery diagnostic method.

13. In Paragraph 12, The operation of diagnosing that degradation has occurred in the positive electrode of the above battery cell is, If it is diagnosed that degradation has occurred in the positive electrode of the battery cell, the operation of changing the upper charging voltage of the battery cell is further included. Battery diagnostic method.

14. In Paragraph 9, The operation of identifying at least one voltage interval above is, In the above temperature profile, the operation of identifying a temperature increase section in which the temperature of the battery cell increases, and The operation of identifying the at least one voltage range using the above temperature increase range, Battery diagnostic method.

15. In Paragraph 9, The operation of identifying at least one voltage interval above is, An operation of identifying a plurality of voltage intervals in the above temperature profile, and The method includes the operation of identifying at least one voltage interval corresponding to a state of charge (SOC) exceeding a designated state of charge (SOC) among the plurality of voltage intervals. Battery diagnostic method.

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