Battery diagnosis device and method therefor

Abstract

A battery diagnosis device according to an embodiment of the present document may comprise a memory for storing at least one instruction, and at least one processor for executing the at least one instruction, wherein the at least one processor: identifies a first temperature that is a temperature related to a battery cell in a first state of charge (SOC); identifies a second temperature that is a temperature related to the battery cell in a second SOC different from the first SOC; and diagnoses the state of the battery cell on the basis of the first temperature and the second temperature.

Description

Battery diagnostic device and method

[0001] Cross-citation with related applications

[0002] The present application claims the benefit of priority based on Korean Patent Application No. 10-2024-0157231 filed November 07, 2024, Korean Patent Application No. 10-2024-0157320 filed November 07, 2024, and Korean Patent Application No. 10-2025-0155808 filed October 24, 2025, and includes all contents disclosed in the documents of said patent applications as part of this specification.

[0003] Technology field

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

[0005] Recently, active research and development on secondary batteries has been underway. Here, secondary batteries are rechargeable batteries that can be interpreted to encompass conventional Ni / Cd and Ni / MH batteries, as well as recent lithium-ion batteries. With their scope of application expanding to include power sources for electric vehicles, they are garnering attention as a next-generation energy storage medium.

[0006] With the proliferation of various electronic devices due to the Fourth Industrial Revolution, battery usage is rapidly increasing. Batteries are gaining prominence as an essential energy source in various fields, such as electric vehicles, portable electronic devices, and renewable energy storage systems. Consequently, the importance of battery condition diagnostic technology to improve battery performance and reliability is growing.

[0007] In particular, with the increasing demand for cost-effective battery cells, technology for diagnosing the condition of such cells is attracting attention. This technology may possess unique characteristics that distinguish it from other battery cell condition diagnostic technologies. The development of cost-effective battery cell diagnostic technology can improve battery reliability.

[0008] According to the embodiments disclosed in this document, we aim to provide a battery diagnostic device and a method for identifying the degree of degradation of the positive electrode of LFP (lithium iron phosphate; LFP) through a temperature change of a battery cell.

[0009] According to the embodiments disclosed in this document, the present invention aims to provide a battery diagnostic device and a method that improve the diagnostic performance of a battery cell by identifying the degree of degradation of the positive electrode of the battery cell.

[0010] According to the embodiments disclosed in this document, the present invention aims to provide a battery diagnostic device and a method thereof that control charging and discharging speeds according to the degree of degradation by identifying the degree of degradation of the positive electrode of a battery cell.

[0011] According to the embodiments disclosed in this document, the present invention aims to provide a battery diagnostic device and a method that improve the stability of a battery cell by controlling the charging and discharging speeds according to the degree of degradation.

[0012] The technical problems of 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 descriptions below.

[0013] A battery diagnostic device according to one embodiment of the present document may include a memory for storing at least one instruction and at least one processor for executing said at least one instruction.

[0014] According to one embodiment, the at least one processor identifies a first temperature associated with a battery cell at a first state of charge (SOC), identifies a second temperature associated with the battery cell at a second SOC different from the first SOC, and can diagnose the state of the battery cell based on the first temperature and the second temperature.

[0015] According to one embodiment, the at least one processor can identify the degree of degradation of the positive electrode included in the battery cell based on the difference between the first temperature and the second temperature.

[0016] According to one embodiment, the degree of degradation of the anode may have a positive correlation with the difference between the first temperature and the second temperature.

[0017] According to one embodiment, the at least one processor can identify the degree of degradation of the anode through the loss of active material (LAM) of the anode.

[0018] According to one embodiment, the battery cell may include a battery cell comprising LFP (lithium iron phosphate; LFP) in the positive electrode.

[0019] According to one embodiment, the first SOC is a first lower SOC (state of charge; SOC) that is less than a critical SOC value, and the second SOC may be a second lower SOC that is less than the critical SOC value and is different from the first lower SOC.

[0020] According to one embodiment, the first lower SOC represents the SOC of the battery cell at the time when the discharge of the battery cell ends, and the second lower SOC may represent the SOC in which the absolute value of the value obtained by differentiating the temperature associated with the battery cell with respect to the SOC within a specified lower SOC range becomes the minimum value.

[0021] According to one embodiment, the lower SOC range may include an SOC value in which the battery cell is identified as being in a completely discharged state.

[0022] According to one embodiment, the first SOC is a first state of charge (SOC) that is greater than or equal to a critical SOC value, and the second SOC may be a second state of charge that is greater than or equal to the critical SOC value and is different from the first state of charge.

[0023] According to one embodiment, the first upper SOC represents the SOC of the battery cell at the time when the discharge of the battery cell begins, and the second upper SOC may represent the SOC at which the temperature associated with the battery cell becomes the maximum value within a specified upper SOC range.

[0024] According to one embodiment, the upper SOC range may include an SOC value in which the battery cell is identified as being in a fully charged state.

[0025] A battery diagnostic method according to another embodiment of the present document may include an operation of identifying a first temperature, which is a temperature associated with a battery cell at a first state of charge (SOC); an operation of identifying a second temperature, which is a temperature associated with the battery cell at a second SOC different from the first SOC; and an operation of diagnosing the state of the battery cell based on the first temperature and the second temperature.

[0026] According to one embodiment, the operation of diagnosing the state of the battery cell based on the first temperature and the second temperature may include the operation of identifying the degree of degradation of the positive electrode included in the battery cell based on the difference between the first temperature and the second temperature.

[0027] According to one embodiment, the degree of degradation of the anode may have a positive correlation with the difference between the first temperature and the second temperature.

[0028] According to one embodiment, the operation of identifying the degree of degradation of a positive electrode included in the battery cell based on the difference between the first temperature and the second temperature may include the operation of identifying the degree of degradation of the positive electrode through the LAM (loss of active material, LAM) of the positive electrode.

[0029] According to one embodiment, the battery cell may include LFP (lithium iron phosphate, LFP) in the positive electrode.

[0030] According to one embodiment, the first SOC is a first lower SOC (state of charge, SOC) that is less than a critical SOC value, and the second SOC may be a second lower SOC that is less than the critical SOC value and is different from the first lower SOC.

[0031] According to one embodiment, the first lower SOC represents the SOC of the battery cell at the time when the discharge of the battery cell ends, and the second lower SOC may represent the SOC in which the absolute value of the value obtained by differentiating the temperature associated with the battery cell with respect to the SOC within a specified lower SOC range becomes the minimum value.

[0032] According to one embodiment, the lower SOC range may include an SOC value in which the battery cell is identified as being in a completely discharged state.

[0033] According to one embodiment, the first SOC is a first state of charge (SOC) that is greater than or equal to a critical SOC value, and the second SOC may be a second state of charge that is greater than or equal to the critical SOC value and is different from the first state of charge.

[0034] According to one embodiment, the first upper SOC represents the SOC of the battery cell at the time when the discharge of the battery cell begins, and the second upper SOC may represent the SOC at which the temperature associated with the battery cell becomes the maximum value within a specified upper SOC range.

[0035] According to one embodiment, the upper SOC range may include an SOC value in which the battery cell is identified as being in a fully charged state.

[0036] This technology can identify the degree of degradation of the positive electrode of LFP (lithium iron phosphate, LFP) through changes in the temperature of the battery cell.

[0037] In addition, this technology can improve the diagnostic performance of a battery cell by identifying the degree of degradation of the positive electrode of the battery cell.

[0038] In addition, the present technology can control the charging and discharging speeds according to the degree of degradation by identifying the degree of degradation of the positive electrode of the battery cell.

[0039] In addition, this technology can improve the stability of battery cells by controlling the charging and discharging speeds according to the degree of degradation.

[0040] In addition, various effects that can be identified directly or indirectly through this document may be provided.

[0041] FIG. 1 is a block diagram showing a battery pack in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0042] FIG. 2 is a block diagram showing the configuration of a battery diagnostic device in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0043] FIG. 3 illustrates an example of a graph showing the temperature according to the capacity of a battery cell in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0044] FIG. 4 illustrates an example of a diagram showing the degree of degradation in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0045] FIG. 5 illustrates an example of a graph showing the temperature according to the capacity of a first cell in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0046] FIG. 6 illustrates an example of a graph showing the temperature according to the capacity of the second cell in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0047] FIG. 7 illustrates the flow of operation of a battery diagnostic device that diagnoses the state of a battery cell based on the temperature of a battery cell having an upper SOC, in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0048] FIG. 8 illustrates the flow of operation of a battery diagnostic device that diagnoses the state of a battery cell based on the temperature of a battery cell having a lower SOC, in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0049] FIG. 9 is a block diagram showing the hardware configuration of a computing system performing a battery diagnostic method in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] In this document, where any component (e.g., 1) is referred to as being “connected,” “coupled,” or “joined” to another component (e.g., 2), with or without the terms “functionally” or “communicationally,” or where it is referred to as “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.

[0056] 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.

[0057] 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, at least one of the aforementioned components or operations may be omitted, or at least one other component or operation 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 at least one function of each of the multiple components in the same or similar manner as it was performed by the corresponding component among the multiple components prior to integration. 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 at least one other operation may be added.

[0058] Hereinafter, embodiments of the present document will be described in detail with reference to FIGS. 1 to 9.

[0059] FIG. 1 is a block diagram showing a battery pack in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0060] Referring to FIG. 1, the battery pack (1) may include a battery unit (12), a sensor unit (14), a switching unit (16), and a battery management system (BMS) (20). At this time, the battery pack (1) may be equipped with a plurality of battery units (12), sensor units (14), switching units (16), and battery management systems (20).

[0061] According to one embodiment, the battery unit (12) can supply power to a target device (not shown). To this end, the battery unit (12) may be electrically connected to the target device. Here, the target device may include an electrical, electronic, or mechanical device that operates by receiving power from the battery pack (1). For example, the target device may be an electric vehicle (EV) or an energy storage system (ESS), but is not limited thereto.

[0062] According to one embodiment, the battery unit (12) may include at least one battery cell (10) capable of charging and discharging. Here, the battery cell (10) may be a basic unit of a battery cell capable of charging and discharging electrical energy. For example, the battery cell (10) may be a lithium-ion (Li-ion) battery, a lithium-ion polymer (Li-ion polymer) battery, a nickel-cadmium (Ni-Cd) battery, a nickel-hydrogen (Ni-MH) battery, etc., but is not limited thereto.

[0063] According to one embodiment, a plurality of battery units (12) may be connected in series or in parallel. For example, a battery unit (12) may be a battery module, a battery bank, or a set of battery cells (cell-to-pack structure).

[0064] According to one embodiment, the sensor unit (14) can obtain information related to the battery unit (12). According to one embodiment, the sensor unit (14) can obtain values ​​(or information) related to the state of each of the battery unit (12) or battery cells (10). In one embodiment, the values ​​related to the state may include at least one value for the voltage, current, resistance, state of charge (SOC), state of health (SOH), or temperature of the battery cell, or a combination thereof.

[0065] According to one embodiment, the sensor unit (14) can provide information of each of the plurality of battery units (12) to the battery management system (20).

[0066] According to one embodiment, the switching unit (16) may include an element for controlling the current flow for charging or discharging the battery unit (12). For example, the switching unit (16) may include at least one relay and / or magnetic contactor, etc., depending on the specifications of the battery pack (1).

[0067] According to one embodiment, a battery management system (BMS) (20) can monitor the voltage, current, temperature, etc. of a battery pack (1) and control or manage the battery pack (1) to prevent overcharging and over-discharging. For example, the battery management system (20) may include a plurality of terminals as an interface for receiving values ​​of the various parameters described above, and a circuit connected to these terminals to perform processing of the received values. Additionally, the battery management system (20) may control a sensor unit (14) and / or a switching unit (16). For example, the battery management system (20) may be connected to a plurality of battery units (12) to monitor the status of each of the plurality of battery units (12) and control the ON / OFF of relays or contactors.

[0068] According to one embodiment, the operation of the battery management system (20) can be performed by a battery management system (BMS) in the vehicle, as well as by various devices such as a server, cloud, charger, or discharger.

[0069] The upper controller (2) can transmit control signals for a plurality of battery units (12) 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).

[0070] According to one embodiment, the battery management system (20) may include the battery diagnostic device (201) of FIG. 2. According to another embodiment, the battery management system (20) may be a different system from the battery diagnostic device (201) of FIG. 2. That is, the battery diagnostic device (201) of FIG. 2 may be included in the battery pack (1) or may be configured as another device outside the battery pack (1). For convenience of explanation, the following description assumes that the battery diagnostic device (201) is configured as another device outside the battery pack (1). Furthermore, the operation of the battery diagnostic device (201) below may be performed by a battery management system (BMS) within the vehicle, as well as by various devices such as a server, cloud, charger, or discharger.

[0071] FIG. 2 is a block diagram showing the configuration of a battery diagnostic device in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0072] FIG. 3 illustrates an example of a graph showing the temperature according to the capacity of a battery cell in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0073] Referring to FIGS. 2 and FIGS. 3, a 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.

[0074] The graph (301) may indicate a change in the measured value of the battery cell according to the discharge capacity of the battery cell. The first line (303) may indicate the voltage of the battery cell according to the discharge capacity. The second line (305) may indicate the temperature of the battery cell according to the discharge capacity. The first range (311) may be referred to as the upper state of charge (SOC) range. The first range (311) may include the SOC value of the battery cell at the time when the discharge of the battery cell begins. The second range (321) may be referred to as the lower SOC range. The second range (321) may include the SOC value of the battery cell at the time when the discharge of the battery cell is completed. The first temperature difference (313) may indicate the difference between the temperature of the battery cell at the first upper SOC and the temperature of the battery cell at the second upper SOC. The second temperature difference (323) may represent the difference between the temperature of the battery cell at the first lower SOC and the temperature of the battery cell at the second lower SOC.

[0075] In the following, the temperature associated with the battery cell is described as the temperature of the battery cell, but the embodiments of this document are not limited thereto. This is because the temperature may not be measured at the battery cell level, but at the battery unit level (e.g., battery module, battery pack, battery). Therefore, according to one embodiment, the temperature associated with the battery cell may be understood as the temperature of the battery unit, which is the unit in which the temperature is measured and which includes the battery cell in which the temperature is measured.

[0076] According to one embodiment, at least one processor of a battery diagnostic device can measure the degree of degradation of a battery cell through a graph showing the voltage according to the SOC of the battery cell.

[0077] However, in the case of battery cells containing LFP (lithium iron phosphate; LFP) as the cathode material, it may be difficult to measure the degree of degradation of the battery cell through a graph showing the voltage according to the SOC of the battery cell.

[0078] For example, in the case of battery cells containing cathode materials other than LFP, the graph representing voltage versus SOC generally has a constant slope; therefore, the line obtained by differentiating voltage with respect to SOC can exhibit a characteristic peak depending on the degree of cathode degradation. However, in the case of battery cells containing LFP as the cathode material, the line obtained by differentiating voltage with respect to SOC does not exhibit a characteristic peak, making it impossible to measure the degree of cathode degradation of the battery cell.

[0079] Therefore, at least one processor (205) of the battery diagnostic device (201) can identify the degree of deterioration of the positive electrode of the battery cell based on a graph showing the temperature according to the SOC, rather than a graph showing the voltage according to the SOC. This is because the graph showing the temperature according to the SOC of the battery cell changes depending on the degree of deterioration of the positive electrode.

[0080] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify the temperature of the battery cell while discharging the battery cell.

[0081] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify a first temperature including the temperature of a battery cell at a first upper SOC that is greater than or equal to a threshold SOC value (e.g., about 50%). The first upper SOC may be included in a first range (311). The first upper SOC may represent the SOC of the battery cell at the time when the discharge of the battery cell begins.

[0082] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify a second temperature including the temperature of a battery cell at a second upper SOC that is greater than or equal to a threshold SOC value. The second upper SOC may represent an SOC where the temperature of the battery cell reaches a maximum value in an upper SOC range (e.g., a first range (311)).

[0083] The upper SOC range (e.g., the first range (311)) may include an SOC value at which the battery cell is identified as being in a fully charged state. Since the X-axis of the graph (301) is the discharge capacity, the SOC of the battery cell in the first range (311) may be higher than the SOC of the battery cell in the second range (321).

[0084] According to one embodiment, the degree of degradation of the positive electrode included in the battery cell can be identified based on the difference between the first temperature and the second temperature (e.g., the first temperature difference (313)). This is because, in the case of a battery cell containing LFP as the positive electrode material, the degree of degradation of the positive electrode and the difference between the first temperature and the second temperature (e.g., the first temperature difference (313)) have a positive correlation.

[0085] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify a third temperature including the temperature of the battery cell at a first lower SOC that is less than a threshold SOC value (e.g., about 50%). The first lower SOC may be included in a second range (321). The first lower SOC may represent the SOC of the battery cell at the time when the discharge of the battery cell ends.

[0086] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify a fourth temperature including the temperature of a battery cell at a second lower SOC that is less than a threshold SOC value. The second upper SOC may represent an SOC where the absolute value of the value obtained by differentiating the temperature of the battery cell with respect to SOC in the lower SOC range (e.g., second range (321)) becomes the minimum value.

[0087] The lower SOC range (e.g., the second range (321)) may include an SOC value in which the battery cell is identified as being in a fully discharged state.

[0088] According to one embodiment, the degree of degradation of the positive electrode included in the battery cell can be identified based on the difference between the third temperature and the fourth temperature (e.g., the second temperature difference (323)). This is because, in the case of a battery cell containing LFP as the positive electrode material, the degree of degradation of the positive electrode and the difference between the third temperature and the fourth temperature (e.g., the second temperature difference (323)) have a positive correlation.

[0089] The degree of degradation of the anode may include the anode's LAM (loss of active material).

[0090] According to one embodiment, the negative electrode material of the battery cell in which the graph (301) is obtained may be graphite, and the positive electrode material may be LFP. The current of the battery cell may be approximately 0.33C (charge)-rate.

[0091] Temperature changes in a battery cell are caused by changes in the entropy of the cathode or anode material and can be related to the battery cell's resistance and current intensity. In the upper SOC range, the stagging reaction, which is a phase change of the cathode, ends, and a temperature change may occur due to the LFP anode material. In the lower SOC range as well, the stagging reaction of the cathode ends, and a temperature change may occur due to the LFP anode material.

[0092] Therefore, at least one processor (205) of the battery diagnostic device (201) can diagnose the condition of the LFP through the temperature change of the battery cell in the upper SOC range and the lower SOC range where the stagging reaction of the negative electrode occurs below a reference value.

[0093] At least one processor (205) of the battery diagnostic device (201) can mitigate uneven degradation within the battery cell by reducing the charging or discharging speed to less than the reference speed when it is confirmed that the degree of degradation of the positive electrode is greater than the reference level.

[0094] According to one embodiment, at least one processor of a battery diagnostic device (201) can identify a first temperature associated with a battery cell at a first state of charge (SOC), identify a second temperature associated with a battery cell at a second SOC different from the first SOC, and diagnose the state of the battery cell based on the first temperature and the second temperature.

[0095] FIG. 4 illustrates an example of a diagram showing the degree of degradation in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0096] FIG. 5 illustrates an example of a graph showing the temperature according to the capacity of a first cell in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0097] FIG. 6 illustrates an example of a graph showing the temperature according to the capacity of the second cell in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0098] Referring to FIGS. 4, 5, and 6, graph (401) can show the degree of degradation of the first cell and the second cell. As shown by graph (401), the degree of degradation of the first cell may be about 9.8%, and the degree of degradation of the second cell may be about 9.8%.

[0099] The graph (501) may indicate a change in the measured value of the battery cell according to the discharge capacity of the first cell. The first line (505) may indicate the temperature of the first cell according to the discharge capacity. The first upper range (511) may be referred to as the upper state of charge (SOC) range. The first lower range (513) may be referred to as the lower SOC range.

[0100] The graph (601) may indicate a change in the measured value of the battery cell according to the discharge capacity of the second cell. The second line (605) may indicate the temperature of the second cell according to the discharge capacity. The second upper range (611) may be referred to as the upper state of charge (SOC) range. The second lower range (621) may be referred to as the lower SOC range.

[0101] According to graph (401), the degree of degradation of the first cell and the second cell is the same, but the ratio of the degree of degradation due to available lithium loss and the degree of degradation due to anode capacity loss may be different. For example, the degree of degradation due to available lithium loss of the first cell may be about 9.5%, and the degree of degradation due to anode capacity loss of the first cell may be about 0.3%. For example, the degree of degradation due to available lithium loss of the second cell may be about 7.9%, and the degree of degradation due to anode capacity loss of the second cell may be about 1.9%.

[0102] At least one processor (205) of the battery diagnostic device (201) can identify the degree of positive capacity loss of the first cell and the degree of positive capacity loss of the second cell through a temperature change according to the SOC of the first cell and the second cell. The degree of positive capacity loss can indicate the degree of degradation of the positive.

[0103] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify the degree of deterioration of the positive electrode of the first cell based on the difference between the first temperature of the first cell at the first upper SOC and the second temperature of the second cell at the second upper SOC in the upper SOC range of the first cell (e.g., the first upper range (511)) of the first line (505) of the graph (501). In the upper SOC range of the first cell of the first line (505), the difference between the first temperature and the second temperature may be about 0.41°C.

[0104] According to one embodiment, in the upper SOC range of the second cell (e.g., second upper range (611)) of the second line (605) of the graph (601), the degree of deterioration of the anode of the second cell can be identified based on the difference between the third temperature of the second cell at the third upper SOC and the fourth temperature of the second cell at the fourth upper SOC. In the upper SOC range of the second cell of the second line (605), the difference between the third temperature and the fourth temperature may be about 0.61°C.

[0105] At least one processor (205) of the battery diagnostic device (201) can identify that, in the upper SOC range, the temperature difference of the second cell (e.g., about 0.61°C) is greater than the temperature difference of the first cell (e.g., about 0.41°C), so the degree of deterioration of the positive electrode of the second cell is greater than the degree of deterioration of the positive electrode of the first cell.

[0106] Therefore, it can be confirmed that the greater the temperature difference within the upper SOC range of the battery cell, the stronger the correlation with the degree of battery cell degradation. This is because the temperature difference differs even though the overall degradation levels of the first and second cells are identical. Specifically, as the degree of degradation of the anode increases, the resistance of the anode increases, and as the resistance of the anode increases, the temperature increases. For example, since the anode of the second cell is more degraded than that of the first cell, the resistance of the second cell may be greater than that of the first cell. Therefore, even if current is supplied to the first and second cells at the same current density, the temperature difference within the upper SOC range of the second cell may be greater than the temperature difference within the upper SOC range of the first cell.

[0107] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify the degree of deterioration of the positive electrode of the first cell based on the difference between the fifth temperature of the first cell at the first lower SOC and the sixth temperature of the first cell at the second lower SOC in the lower SOC range of the first cell (e.g., first lower range (513)) of the first line (505) of the graph (501). In the lower SOC range of the first cell of the first line (505), the difference between the fifth temperature and the sixth temperature may be about 0.46°C.

[0108] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify the degree of deterioration of the positive electrode of the second cell based on the difference between the seventh temperature of the second cell at the third lower SOC and the eighth temperature of the second cell at the fourth lower SOC in the lower SOC range of the second cell of the second line (605) of the graph (601). In the lower SOC range of the second cell of the second line (605), the difference between the seventh temperature and the eighth temperature may be about 0.8°C.

[0109] At least one processor (205) of the battery diagnostic device (201) can identify that, in the lower SOC range, the temperature difference of the second cell (e.g., about 0.8°C) is greater than the temperature difference of the first cell (e.g., about 0.46°C), so the degree of degradation of the positive electrode of the second cell is greater than the degree of degradation of the positive electrode of the first cell.

[0110] As with the upper SOC range, it can be confirmed that the greater the temperature difference in the lower SOC range of the battery cell, the greater the correlation with the degree of battery cell degradation. This is because the temperature difference differs, even though the overall degree of degradation of the first and second cells is consistent. Specifically, as with the upper SOC range, since the positive electrode of the second cell is more degraded than the positive electrode of the first cell, the resistance of the second cell may be greater than that of the first cell. Therefore, even if current is supplied to the first and second cells through the same current density, the temperature difference in the lower SOC range of the second cell may be greater than the temperature difference in the lower SOC range of the first cell.

[0111] The temperature measurement method shown in FIGS. 4 and FIGS. 5 may be a method of attaching a temperature measuring device to a metal plate after compressing a pouch-type first cell or second cell. However, the embodiments of this document are not limited thereto. As the accuracy of the method for measuring the temperature of a battery cell improves, the accuracy of the method for measuring the degree of degradation of the positive electrode through the temperature difference may improve.

[0112] FIG. 7 illustrates the flow of operation of a battery diagnostic device that diagnoses the state of a battery cell based on the temperature of a battery cell having an upper SOC, in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0113] In the following, it is assumed that at least one processor (205) included in the battery diagnostic device (201) of FIG. 2 performs the process of FIG. 7. Additionally, in the description of FIG. 7, the operation described as being performed by the battery diagnostic device (201) can be understood as being controlled by at least one processor (205) included in the battery diagnostic device (201).

[0114] Referring to FIG. 7, in the first operation (701), at least one processor (205) of the battery diagnostic device (201) according to one embodiment can identify a first temperature, which is a temperature associated with a battery cell at a first upper SOC that is greater than or equal to a threshold SOC value.

[0115] According to one embodiment, the temperature associated with the battery cell may be understood as the temperature of the battery cell or the temperature of the battery unit, which includes the battery cell whose temperature is being measured and is the unit in which the temperature is being measured. According to one embodiment, the first upper SOC may represent the SOC of the battery cell at the time when the discharge of the battery cell begins.

[0116] In the second operation (703), at least one processor (205) of the battery diagnostic device (201) according to one embodiment can identify a second temperature, which is a temperature associated with a battery cell at a second upper SOC that is different from the first upper SOC.

[0117] According to one embodiment, the second upper SOC may represent an SOC in which the temperature of the battery cell or the temperature of the battery becomes a maximum value within a specified upper SOC range.

[0118] In the third operation (705), at least one processor (205) of the battery diagnostic device (201) according to one embodiment can diagnose the state of the battery cell based on the first temperature and the second temperature.

[0119] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify the degree of degradation of the positive electrode of a battery cell, which has a positive correlation with the difference between the first temperature and the second temperature, based on the difference between the first temperature and the second temperature.

[0120] FIG. 8 illustrates the flow of operation of a battery diagnostic device that diagnoses the state of a battery cell based on the temperature of a battery cell having a lower SOC, in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0121] In the following, it is assumed that at least one processor (205) included in the battery diagnostic device (201) of FIG. 2 performs the process of FIG. 8. Additionally, in the description of FIG. 8, the operation described as being performed by the battery diagnostic device (201) can be understood as being controlled by at least one processor (205) included in the battery diagnostic device (201).

[0122] In the first operation (801), at least one processor (205) of the battery diagnostic device (201) according to one embodiment can identify a first temperature, which is a temperature associated with a battery cell at a first lower SOC that is less than a threshold SOC value.

[0123] According to one embodiment, the temperature associated with the battery cell can be understood as the temperature of the battery cell or the temperature of the battery unit, which includes the battery cell in which the temperature is measured and is the unit in which the temperature is measured.

[0124]

[0125] According to the 105-day embodiment, the first lower SOC may represent the SOC of the battery cell at the time when the discharge of the battery cell ends.

[0126] In the second operation (803), at least one processor (205) of the battery diagnostic device (201) according to one embodiment can identify a second temperature, which is a temperature associated with a battery cell at a second lower SOC that is different from a first lower SOC.

[0127] According to one embodiment, the second lower SOC may represent an SOC in which the absolute value of the value obtained by differentiating the temperature of the battery cell or the temperature of the battery with respect to the SOC is at its minimum within a specified lower SOC range.

[0128] In the third operation (805), at least one processor (205) of the battery diagnostic device (201) according to one embodiment can diagnose the state of the battery cell based on the first temperature and the second temperature.

[0129] According to one embodiment, at least one processor (205) of the battery diagnostic device (201) can identify the degree of degradation of the positive electrode of a battery cell, which has a positive correlation with the difference between the first temperature and the second temperature, based on the difference between the first temperature and the second temperature.

[0130] FIG. 9 is a block diagram showing the hardware configuration of a computing system performing a battery diagnostic method in a battery diagnostic device and a battery diagnostic method according to one embodiment of the present document.

[0131] Referring to FIG. 9, a computing system (900) according to one embodiment disclosed in this document may include an MCU (910), memory (920), an input / output I / F (930), and a communication I / F (940).

[0132] The MCU (910) may be one or more processors that execute various programs stored in memory (920) (e.g., battery cell data collection program, graph generation program, data analysis program, data decomposition algorithm, normalization program, battery cell diagnosis program, etc.), process various information including characteristic data of the battery cell, potential variables, etc. through these programs, and perform the functions of the battery diagnosis device (201) shown in FIGS. 2 to 8.

[0133] The memory (920) can store various programs such as a battery cell data collection program, a graph generation program, a data analysis program, a data decomposition algorithm, a normalization program, and a battery cell diagnosis program.

[0134] These memories (920) may be provided in multiple quantities as needed. The memories (920) may be volatile memories or non-volatile memories. As volatile memories, the memory (920) may use RAM, DRAM, SRAM, etc. As non-volatile memories, the memory (920) may use ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc. The examples of the listed memories (920) are merely examples and are not limited to these examples.

[0135] The input / output I / F (930) can provide an interface that enables data transmission and reception between an input device (not shown), such as a keyboard, mouse, or touch panel, and an output device (not shown), such as a display, and the MCU (910).

[0136] The communication I / F (940) is configured to transmit and receive various data with a server and may be various devices capable of supporting wired or wireless communication. For example, the battery diagnostic device (201) can transmit and receive various information, including the shape model of a battery cell, from a separately provided external server via the communication I / F (940).

[0137] In this way, a computer program according to one embodiment disclosed in this document may be implemented as a module that performs, for example, the functions illustrated in FIG. 2, by being recorded in memory (920) and processed by an MCU (910).

[0138] 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.

[0139] 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.

[0140] The foregoing disclosure outlines the features of several embodiments to enable those skilled in the art to better understand the aspects of the present disclosure. Those skilled in the art will understand that the present disclosure can be readily used as a basis for designing or modifying other structures to perform the same purpose or achieve the same advantages as the embodiments introduced herein. Furthermore, those skilled in the art will recognize that such equivalent configurations do not depart from the scope of the present disclosure and that various changes, substitutions, and modifications may be made in the present specification without departing from the scope of the present disclosure.

Claims

1. Memory storing at least one instruction; and It includes at least one processor that executes the above at least one instruction, and The above at least one processor is, Identifying a first temperature associated with a battery cell at a first state of charge (SOC), and identifying a second temperature associated with the battery cell at a second SOC that is different from the first SOC. Configured to diagnose the state of the battery cell based on the first temperature and the second temperature. Battery diagnostic device.

2. In Claim 1, The above at least one processor is, A configuration configured to identify the degree of degradation of the positive electrode included in the battery cell based on the difference between the first temperature and the second temperature. Battery diagnostic device.

3. In Claim 2, The degree of degeneration of the above-mentioned anode is, Having a positive correlation with the difference between the first temperature and the second temperature, Battery diagnostic device.

4. In Claim 2, The above at least one processor is, Configured to identify the degree of degradation of the anode through the LAM (loss of active material; LAM) of the anode, Battery diagnostic device.

5. In Claim 1, The above battery cell is, A battery cell comprising LFP (lithium iron phosphate; LFP) in the positive electrode, Battery diagnostic device.

6. In Claim 1, The above-mentioned first SOC is, It is a first lower SOC (state of charge; SOC) less than the critical SOC value, and The above 2 SOC is, A second lower SOC that is less than the above threshold SOC value and is different from the first lower SOC, Battery diagnostic device.

7. In Claim 6, The above-mentioned first lower SOC is, Indicates the SOC of the battery cell at the point when the discharge of the battery cell ends, and The above second lower SOC is, Representing the SOC where the absolute value of the derivative of the temperature associated with the battery cell with respect to SOC becomes the minimum value within a specified lower SOC range, Battery diagnostic device.

8. In Claim 7, The above lower SOC range is, The above battery cell includes an SOC value identified as being in a completely discharged state, Battery diagnostic device.

9. In Claim 1, The above-mentioned first SOC is, It is a first upper SOC (state of charge; SOC) greater than or equal to a critical SOC value, and The above 2 SOC is, A second upper SOC that is greater than or equal to the above threshold SOC value and is different from the first upper SOC, Battery diagnostic device.

10. In Claim 9, The above first upper SOC is, Indicates the SOC of the battery cell at the point when the discharge of the battery cell begins, and The above second upper SOC is, Indicating the SOC where the temperature associated with the battery cell becomes the maximum value within a specified upper SOC range, Battery diagnostic device.

11. In Claim 10, The above upper SOC range is, The above battery cell includes an SOC value identified as being in a fully charged state, Battery diagnostic device.

12. An operation to identify a first temperature, which is a temperature associated with a battery cell at a first state of charge (SOC); An operation to identify a second temperature, which is a temperature associated with the battery cell at a second SOC different from the first SOC; and A method including an operation to diagnose the state of the battery cell based on the first temperature and the second temperature. Battery diagnostic method.

13. In Claim 12, The operation of diagnosing the state of the battery cell based on the first temperature and the second temperature is, A method comprising identifying the degree of degradation of a positive electrode included in the battery cell based on the difference between the first temperature and the second temperature. Battery diagnostic method.

14. In Claim 13, The degree of degeneration of the above-mentioned anode is, Having a positive correlation with the difference between the first temperature and the second temperature, Battery diagnostic method.

15. In Claim 13, The operation of identifying the degree of degradation of the positive electrode included in the battery cell based on the difference between the first temperature and the second temperature is, A method comprising identifying the degree of degradation of the anode through the LAM (loss of active material) of the anode. Battery diagnostic method.

16. In Claim 12, The above battery cell is, A battery cell comprising LFP (lithium iron phosphate; LFP) in the positive electrode, Battery diagnostic method.

17. In Claim 12, The above-mentioned first SOC is, It is a first lower SOC (state of charge; SOC) less than the critical SOC value, and The above 2 SOC is, A second lower SOC that is less than the above threshold SOC value and is different from the first lower SOC, Battery diagnostic method.

18. In Claim 17, The above-mentioned first lower SOC is, Indicates the SOC of the battery cell at the point when the discharge of the battery cell ends, and The above second lower SOC is, Representing the SOC where the absolute value of the derivative of the temperature associated with the battery cell with respect to SOC becomes the minimum value within a specified lower SOC range, Battery diagnostic method.

19. In Claim 18, The above lower SOC range is, The above battery cell includes an SOC value identified as being in a completely discharged state, Battery diagnostic method.

20. In Claim 12, The above-mentioned first SOC is, It is a first upper SOC (state of charge; SOC) greater than or equal to a critical SOC value, and The above 2 SOC is, A second upper SOC that is greater than or equal to the above threshold SOC value and is different from the first upper SOC, Battery diagnostic method.

21. In claim 20, The above first upper SOC is, Indicates the SOC of the battery cell at the point when the discharge of the battery cell begins, and The above second upper SOC is, Indicating the SOC where the temperature associated with the battery cell becomes the maximum value within a specified upper SOC range, Battery diagnostic method.

22. In Claim 21, The above upper SOC range is, The above battery cell includes an SOC value identified as being in a fully charged state, Battery diagnostic method.

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