Impedance analysis device and operation method thereof

Abstract

An impedance analysis device according to one embodiment disclosed in the present document may comprise: an interface for acquiring, on the basis of electrochemical impedance spectroscopy (EIS), reference impedance data including first reference impedance data and second reference impedance data corresponding, respectively, to the positive electrode and the negative electrode of a reference battery; and a controller for generating, on the basis of DRT, reference distribution of relaxation times (DRT) data by converting the first reference impedance data and the second reference impedance data into first reference DRT data and second reference DRT data, respectively, generating first unit distribution data and second unit distribution data in which each of the first reference DRT data and the second reference DRT data are represented as one or more unit distributions, and extracting one or more parameters corresponding to each of the one or more unit distributions.

Description

Impedance analysis device and method of operation thereof

[0001] Cross-citation with related applications

[0002] The present invention claims the benefit of priority based on Korean Patent Application No. 10-2024-0192414 filed on December 20, 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 an impedance analysis device and a method of operating the same.

[0005] Recently, active research and development on secondary batteries has been underway. Here, the term "secondary battery" refers to a rechargeable battery, encompassing conventional Ni / Cd and Ni / MH batteries as well as the more recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries have the advantage of significantly higher energy density compared to conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight form factor, making them suitable for use as power sources for mobile devices. Recently, their scope of application has expanded to include electric vehicles, drawing attention as a next-generation energy storage medium.

[0006] As the industrial sectors utilizing batteries expand, technologies for diagnosing battery safety are also advancing. Electrochemical Impedance Spectroscopy (EIS), one of the battery diagnostic methods, is a technique that analyzes the electrochemical characteristics of batteries and can non-destructively diagnose their condition.

[0007] To analyze the electrochemical characteristics of a battery more precisely, there is a Distribution of Relaxation Times (DRT) technique that converts impedance data obtained through EIS inspection into data regarding time constants. DRT corresponds to a mathematical transformation capable of determining the time constants of physical processes occurring within an electrochemical system. The DRT data, which is the result of performing the transformation on the impedance data obtained through EIS inspection, can include multiple peak points with different time constants; since each of these peak points corresponds to the battery's impedance, the battery's condition can be diagnosed based on these peak points.

[0008] In order to precisely analyze the electrochemical characteristics of a battery, impedance data and DRT data for each of the positive and negative electrodes included in the battery are required. To obtain data for each electrode, it was necessary to disassemble the battery, fabricate half-cells from each electrode, and perform EIS inspection. However, since the battery's structure, including the SEI layer, may be destroyed during the disassembly process, there is a problem in that the accuracy of the data obtained through this method is reduced.

[0009] 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.

[0010] An impedance analysis device according to one embodiment disclosed in this document may include: an interface for acquiring reference impedance data including first reference impedance data and second reference impedance data corresponding to each of the positive and negative electrodes of a reference battery based on electrochemical impedance spectroscopy (EIS); and a controller for generating reference DRT data by converting each of the first reference impedance data and the second reference impedance data into first reference DRT data and second reference DRT data based on a distribution of relaxation times (DRT), generating first unit distribution data and second unit distribution data representing each of the first reference DRT data and the second reference DRT data as one or more unit distributions, and extracting one or more parameters corresponding to each of the one or more unit distributions.

[0011] In one embodiment, the unit distribution includes a Gaussian distribution, the first unit distribution data is a first Gaussian distribution data including one or more Gaussian distributions, and the second unit distribution data may be a second Gaussian distribution data including one or more Gaussian distributions.

[0012] In one embodiment, the controller can generate the first Gaussian distribution data and the second Gaussian distribution data based on one or more peak points included in each of the first reference DRT data and the second reference DRT data.

[0013] In one embodiment, the one or more parameters may include at least one of the center of the peak point, maximum value, standard deviation, full width at half maximum, and area for each of the one or more Gaussian distributions.

[0014] In one embodiment, the interface may further acquire target impedance data of a target battery subject to impedance analysis, and the controller may convert the target impedance data into target DRT data and generate correction data in which at least one value of the one or more parameters is corrected so that the reference DRT data is fitted to the target DRT data.

[0015] In one embodiment, the controller can separate the target DRT data into a first target DRT data and a second target DRT data corresponding to the positive and negative electrodes of the target battery, respectively, based on the correction data.

[0016] In one embodiment, the controller can diagnose the state of the target battery based on the first target DRT data and the second target DRT data.

[0017] In one embodiment, the controller extracts the positive impedance value and the negative impedance value of the target battery based on the first target DRT data and the second target DRT data, and can diagnose the degree of degradation of the target battery based on the ratio of the positive impedance value and the negative impedance value.

[0018] In one embodiment, the controller may identify a specified frequency range based on the reference impedance data and generate the first unit distribution data and the second unit distribution data based on the specified frequency range.

[0019] In one embodiment, the first reference impedance data and the second reference impedance data may each include a first reference Nyquist plot and a second reference Nyquist plot, and the controller may identify the specified frequency range based on the frequency of the impedance value corresponding to the semicircle included in the first reference Nyquist plot and the second reference Nyquist plot.

[0020] A method of operation of an impedance analysis device according to an embodiment disclosed in this document may include: acquiring reference impedance data including first reference impedance data and second reference impedance data corresponding to the positive and negative electrodes of a reference battery, respectively, based on electrochemical impedance spectroscopy (EIS); generating reference DRT data by converting each of the first reference impedance data and the second reference impedance data into first reference DRT data and second reference DRT data, respectively, based on a distribution of relaxation times (DRT); generating first unit distribution data and second unit distribution data representing each of the first reference DRT data and the second reference DRT data as one or more unit distributions; and extracting one or more parameters corresponding to each of the one or more unit distributions.

[0021] In one embodiment, the unit distribution includes a Gaussian distribution, the first unit distribution data is a first Gaussian distribution data including one or more Gaussian distributions, and the second unit distribution data may be a second Gaussian distribution data including one or more Gaussian distributions.

[0022] In one embodiment, the operation of generating the first Gaussian distribution data and the second Gaussian distribution data may include the operation of generating the first Gaussian distribution data and the second Gaussian distribution data based on one or more peak points included in each of the first reference DRT data and the second reference DRT data.

[0023] In one embodiment, the one or more parameters may include at least one of the center of the peak point, maximum value, standard deviation, full width at half maximum, and area for each of the one or more Gaussian distributions.

[0024] In one embodiment, the method of operation of the impedance analysis device may further include: acquiring target impedance data of a target battery to be analyzed for impedance; converting the target impedance data into target DRT data; and generating correction data in which at least one value of the one or more parameters is corrected so that the reference DRT data is fitted to the target DRT data.

[0025] In one embodiment, the method of operation of the impedance analysis device may further include the operation of separating the target DRT data into first target DRT data and second DRT target data corresponding to the positive and negative electrodes of the target battery, respectively, based on the correction data.

[0026] In one embodiment, the method of operation of the impedance analysis device may further include an operation of diagnosing the state of the target battery based on the first target data and the second target data.

[0027] In one embodiment, the diagnosing operation may include the operation of extracting the positive impedance and negative impedance of the target battery based on the first target DRT data and the second target DRT data, and the operation of diagnosing the degree of degradation of the target battery based on the ratio of the positive impedance and the negative impedance.

[0028] In one embodiment, the method of operation of the impedance analysis device may further include an operation of identifying a designated frequency range based on the reference impedance data, and the operation of generating the first unit distribution data and the second unit distribution data may include an operation of generating the first Gaussian distribution data and the second Gaussian distribution data based on the designated frequency range.

[0029] In one embodiment, the first reference impedance data and the second reference impedance data may each include a first reference Nyquist plot and a second reference Nyquist plot, and the operation of identifying the designated frequency range may include the operation of identifying the designated frequency range based on the frequency of the impedance value corresponding to the semicircle included in the first reference Nyquist plot and the second reference Nyquist plot.

[0030] An impedance analysis device and a method of operation thereof according to various embodiments disclosed in this document can extract one or more parameters from DRT data generated based on a 3-electrode cell corresponding to a battery subject to impedance analysis, and can correct at least one value of said parameters such that the sum of the positive DRT data of a reference battery cell and the negative DRT data of a reference battery cell fits the DRT data of the battery subject to impedance analysis. Furthermore, the impedance analysis device and a method of operation thereof can separate the DRT data of the battery subject to impedance analysis into positive and negative DRT data, respectively, based on the corrected parameters.

[0031] Accordingly, the impedance analysis device and the method of operation thereof can generate DRT data for each of the anode and cathode through a non-destructive method.

[0032] The effects of the impedance analysis device and the method of operation thereof disclosed in this document are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art in accordance with the disclosure of this document.

[0033] FIG. 1 is a block diagram of an impedance analysis device according to one embodiment disclosed in this document.

[0034] FIG. 2 illustrates second reference DRT data corresponding to the negative electrode of a reference battery according to one embodiment disclosed in this document.

[0035] FIG. 3 illustrates DRT data corresponding to a specified frequency range according to one embodiment disclosed in this document.

[0036] FIG. 4 is a diagram illustrating a method for generating Gaussian distribution data according to an embodiment disclosed in this document.

[0037] FIG. 5 illustrates parameters extracted based on Gaussian distribution data according to one embodiment disclosed in this document.

[0038] FIG. 6 is a diagram illustrating a method of fitting first reference DRT data and second reference DRT data to target DRT data according to one embodiment disclosed in this document.

[0039] FIG. 7 is a diagram illustrating a method for separating target DRT data into first target DRT data and second target DRT data according to an embodiment disclosed in this document.

[0040] FIG. 8 is a flowchart illustrating the operation method of an impedance analysis device for extracting parameters according to an embodiment disclosed in this document.

[0041] FIG. 9 is a flowchart illustrating the operation method of an impedance analysis device for separating target DRT data into first target DRT data and second target DRT data according to one embodiment disclosed in this document.

[0042] FIG. 10 illustrates a computing system for executing operations of an impedance analysis device according to an embodiment disclosed in this document.

[0043] In relation to the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0044] Hereinafter, embodiments of the present invention are described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments and should be understood to include various modifications, equivalents, and / or alternatives of the embodiments of the present invention.

[0045] The embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of said items unless the relevant context clearly indicates otherwise.

[0046] In this document, each of the phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” “first,” “second,” “A,” “B,” “(a),” or “(b)” may be used simply to distinguish a component from another component and, unless specifically stated otherwise, do not limit the components in any other aspect (e.g., importance or order).

[0047] In this document, where it is stated that any (e.g., 1) component is "connected," "coupled," or "joined" to another (e.g., 2) component, with or without the terms "functionally" or "communicationly," or where it is stated that the component is "coupled" or "connected," it means that the component may be connected to the other component directly (e.g., by wire or wirelessly) or indirectly (e.g., through a 3) component.

[0048] Methods according to the various embodiments disclosed in this document may be provided as part of a computer program product. The computer program product may be traded between a seller and a buyer as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory, CD-ROM) or distributed online (e.g., download or upload) through an application store or directly between two 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.

[0049] According to the embodiments disclosed in this document, each component (e.g., module or program) of the components described above may include a singular or multiple entities, and some of the multiple entities may be separated and placed in other components. According to the embodiments disclosed in this document, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Generally or additionally, multiple components (e.g., module or program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the components of the multiple components in the same or similar manner as those performed by the corresponding components among the multiple components prior to the integration. According to the embodiments disclosed in this document, operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0050] FIG. 1 is a block diagram of an impedance analysis device according to one embodiment disclosed in this document.

[0051] The impedance analysis device (10) can acquire reference impedance data of a reference battery based on electrochemical impedance spectroscopy (EIS). Here, the reference battery can be manufactured to simulate the impedance data of a target battery that is subject to impedance analysis, and can be manufactured as a 3-electrode cell corresponding to the target battery. The 3-electrode cell may include a chemical composition corresponding to the target battery and may include a working electrode, a counter electrode, and a reference electrode. Here, the counter electrode performs the role of completing the electrical circuit and maintains electrical neutrality to prevent overload or side reactions, so the 3-electrode cell can obtain more accurate electrochemical data than a 2-electrode cell. The target battery may include a cylindrical battery, a pouch battery, and a coin battery, etc. The reference impedance data may include first reference impedance data and second reference impedance data corresponding to the positive and negative electrodes of the reference battery, respectively.

[0052] The impedance analysis device (10) can generate reference DRT data by converting reference impedance data into reference DRT data based on the Distribution of Relaxation Times (DRT). The impedance analysis device (10) can convert the first reference impedance data and the second reference impedance data into the first reference DRT data and the second reference DRT data, respectively.

[0053] The impedance analysis device (10) can extract one or more parameters from reference DRT data and can generate corrected data by correcting at least one of the parameters so that the reference DRT data corresponds to the target DRT data.

[0054] The impedance analysis device (10) can generate impedance data for each of the positive and negative electrodes of the target battery without disassembling the target battery by separating the target DRT data into a first target DRT data and a second target DRT data corresponding to the positive and negative electrodes of the target battery based on correction data.

[0055] In one embodiment, operations performed by the impedance analysis device (10) may be performed on a PC or an external server for diagnosing abnormalities before shipping a battery manufactured in a battery manufacturing process. In one embodiment, the impedance analysis device (10) may be included in a BMS capable of diagnosing battery cells included in an electronic device, and operations performed by the impedance analysis device (10) may be performed in the BMS. Here, the electronic device may be a mobile device (e.g., mobile phone, laptop computer, smartphone, smart pad), an electric vehicle (e.g., EV (electric vehicle), HEV (hybrid EV), PHEV (plug-in HEV), FCEV (fuel cell EV)), an energy storage system (ESS), or a battery swapping system (BSS). In one embodiment, the impedance analysis device (10) may be included in a server or charger / discharger capable of diagnosing battery cells outside of an electronic device, and operations performed by the impedance analysis device (10) may be performed on an external server or charger / discharger.

[0056] In the following, the components included in the impedance analysis device (10) will be described separately as a method for extracting parameters based on impedance data of a reference battery, a method for fitting reference DRT data to target DRT data, a method for separating target DRT data into first target DRT data and second target DRT data corresponding to the positive and negative electrodes of the target battery, respectively, and a method for diagnosing the target battery based on the first target DRT data and the second target DRT data.

[0057] Method to extract parameters

[0058] Referring to FIG. 1, the impedance analysis device (10) may include an interface (100) and a controller (102). According to an embodiment, the impedance analysis device (10) illustrated in FIG. 1 may further include at least one component (e.g., a display, an input device, or an output device) in addition to the components illustrated in FIG. 1.

[0059] The interface (100) can acquire reference impedance data of a reference battery (e.g., a 3-electrode mono cell corresponding to a target battery) based on electrochemical impedance spectroscopy. The interface (100) can acquire reference impedance data including first reference impedance data and second reference impedance data corresponding to the positive and negative electrodes of the reference battery, respectively. Here, the impedance data may include a Nyquist plot. According to various embodiments, the interface (100) may include various interface circuits for acquiring signals, information, and / or data, such as sensors and communication circuits. For example, the interface (100) may include a communication circuit and receive the reference impedance data through communication with an EIS measuring device (not shown).

[0060] The controller (102) can generate reference DRT data by performing DRT conversion on reference impedance data based on relaxation time distribution. The controller (102) can generate reference DRT data by converting the first reference impedance data and the second reference impedance data, respectively, into the first reference DRT data and the second reference DRT data.

[0061] The controller (102) can generate unit distribution data including first unit distribution data and second unit distribution data, each representing the first reference DRT data and the second reference DRT data as one or more unit distributions. Here, the unit distribution may be a unit for representing the reference DRT data as the sum of one or more distributions. For example, the unit distribution may include a Gaussian distribution, a Voigt profile, and a Lorentzian function. For convenience of explanation, the following description assumes that the unit distribution is a Gaussian distribution.

[0062] In one embodiment, the controller (102) may generate Gaussian distribution data including first Gaussian distribution data and second Gaussian distribution data, each of which represents first reference DRT data and second reference DRT data as one or more Gaussian distributions. Here, the Gaussian distribution may be a continuous probability distribution that is symmetric with respect to the mean based on the mean and standard deviation of the collected data.

[0063] In one embodiment, the controller (102) can identify a specified frequency range based on reference impedance data. Here, the specified frequency range may correspond to a range excluding frequencies corresponding to a range with low accuracy during DRT transformation (e.g., diffusion range) among the frequency ranges included in the impedance data (e.g., Nyquist plot). For example, the specified frequency range may include a range corresponding to a semicircle range included in the Nyquist plot. The controller (102) can generate first Gaussian distribution data and second Gaussian distribution data based on the specified frequency range.

[0064] In one embodiment, the controller (102) can identify one or more peak points included in each of the first reference DRT data and the second reference DRT data. Here, a peak point may refer to a point corresponding to a maximum value among the values ​​included in the DRT data. The maximum value may be identified based on the first derivative or the second derivative value of the values ​​included in the DRT data. The controller (102) can generate first Gaussian distribution data and second Gaussian distribution data based on the peak points included in the first reference DRT data and the peak points included in the second reference DRT data. A method for generating Gaussian distribution data based on peak points is described later in FIG. 3.

[0065] The controller (102) can extract one or more parameters corresponding to each of one or more Gaussian distributions included in the Gaussian distribution data. The controller (102) can extract one or more parameters (hereinafter referred to as first parameters) corresponding to each of one or more Gaussian distributions (hereinafter referred to as first Gaussian distributions) included in the first Gaussian distribution data, and can extract one or more parameters (hereinafter referred to as second parameters) corresponding to each of one or more Gaussian distributions (hereinafter referred to as second Gaussian distributions) included in the second Gaussian distribution data. Here, the parameters may include at least one of the center of the peak, the maximum value, the standard deviation, the Full Width at Half Maximum (FWHM), and the area for each Gaussian distribution. Here, the center of the peak may include the median value or the mean value of the peak. In the following description, it is assumed that the center of the peak is the median value of the peak, but this is merely for convenience of explanation and the center of the peak is not limited to the median value.

[0066] In another embodiment, when the unit distribution is a Lorentz function, the parameters corresponding to the Lorentz function may include an area (amplitude), a peak center, gamma (corresponding to the standard deviation in a Gaussian distribution), FWMH, and a maximum value. Additionally, when the unit distribution is a Vogt profile, the parameters corresponding to the Vogt profile may include an area (amplitude), a peak center, sigma (a parameter in a Gaussian distribution), gamma (a parameter in a Lorentz function), FWHM, and a maximum value.

[0067] In the above, it was assumed that the unit distribution is a Gaussian distribution, a Lorenz function, or a Vogt profile, but this is for convenience of explanation only and the embodiments of the present invention are not limited thereto. For example, the unit distribution may be a combination of one or more of a Gaussian distribution, a Lorenz function, and a Vogt profile.

[0068] How to fit reference DRT data to target DRT data

[0069] The interface (100) can further acquire target impedance data of the target battery that is the subject of impedance analysis.

[0070] The controller (102) can convert target impedance data into target DRT data. The controller (102) can generate target DRT data by performing DRT conversion on the target impedance data.

[0071] The controller (102) can fit reference DRT data to target DRT data. The controller (102) can fit reference DRT data to target DRT data by correcting at least one of the first reference DRT data and the second reference data. For example, the controller (102) can generate a virtual interpolation distribution between reference DRT data and target DRT data, and can specify initial parameters required for performing fitting by shifting the positive and negative peak points based on the interpolation distribution.

[0072] In one embodiment, the controller (102) can generate correction data by correcting at least one value of one or more parameters so that the reference DRT data is fitted to the target DRT data. The controller (102) can generate correction data by correcting at least one of the first parameter and the second parameter so that the sum of the first reference DRT data and the second reference DRT data corresponds to the target DRT data. The controller (102) can fit the first reference DRT data and the second reference DRT data to the target DRT data by correcting at least one value of the first parameter extracted from the first Gaussian distribution and correcting at least one value of the second parameter extracted from the second Gaussian distribution. Here, the correction data may include a value corrected by correcting at least one value among the median, maximum value, standard deviation, full width at half maximum, and area included in the first parameter and the second parameter. In one embodiment, the controller (102) can correct the median value included in the first parameter and the median value included in the second parameter to correspond the median value of the first Gaussian distribution and the median value of the second Gaussian distribution to the frequency value (log(frequency) / Hz) of the first peak point. In another embodiment, the controller (102) can generate correction data by setting a boundary condition for at least one of the width, height, and area of ​​the Gaussian distribution and applying the least squares method.

[0073] Method to separate target DRT data

[0074] The controller (102) can separate the target DRT data into a first target DRT data and a second target DRT data corresponding to the positive and negative electrodes of the target battery, respectively, based on the correction data.

[0075] In one embodiment, the controller (102) can extract a first target DRT data corresponding to the positive electrode of the target battery among the target DRT data based on the correction data, and can separate the target DRT data into the first target DRT data and the second target DRT data by extracting a second target DRT data corresponding to the negative electrode of the target battery among the target DRT data.

[0076] How to diagnose a target battery

[0077] The controller (102) can diagnose the condition of the target battery based on the first target DRT data and the second target DRT data. The controller (102) can diagnose whether there is an abnormality in the positive electrode of the target battery based on the first target DRT data. The controller (102) can diagnose whether there is an abnormality in the negative electrode of the target battery based on the second target DRT data.

[0078] In one embodiment, the controller (102) can diagnose the degree of degradation of each electrode by distinguishing between cases where it is confirmed that the positive impedance tends to change rapidly based on first target DRT data and cases where it is confirmed that the negative impedance tends to change rapidly based on second target DRT data for target cells with different degradation patterns at different temperatures. For example, if battery capacity degradation occurs at high temperatures through an experiment, the controller (102) can diagnose the degree of degradation of the positive electrode by confirming the tendency of the amount of change in positive impedance to change rapidly based on first target DRT data. Similarly, the controller (102) can diagnose the degree of degradation of the negative electrode based on second target DRT data. For example, if it is confirmed through an experiment that the amount of change in negative impedance (e.g., the amount of change in charge transfer resistance according to charge-discharge cycles) of the negative electrode of the battery tends to change rapidly at 25 degrees Celsius, the controller (102) can diagnose the degree of degradation of the negative electrode based on second target DRT data. Likewise, if it is confirmed through experiments that the positive electrode of the battery tends to change rapidly in the amount of change in positive electrode impedance at 45 degrees Celsius, the controller (102) can diagnose the degree of degradation of the positive electrode based on the first target DRT data.

[0079] In one embodiment, the controller (102) can extract the positive impedance value and the negative impedance value of the target battery based on the first target DRT data and the second target DRT data. The controller (102) can diagnose the degree of degradation of the target battery based on the ratio of the positive impedance value and the negative impedance value.

[0080] FIG. 2 illustrates second reference DRT data corresponding to the negative electrode of a reference battery according to one embodiment disclosed in this document. FIG. 3 illustrates DRT data corresponding to a specified frequency range according to one embodiment disclosed in this document. FIG. 4 is a diagram illustrating a method for generating Gaussian distribution data according to one embodiment disclosed in this document. FIG. 5 illustrates parameters extracted based on Gaussian distribution data according to one embodiment disclosed in this document.

[0081] Referring to FIG. 2, the second reference DRT data (20) can be generated based on the second reference impedance data corresponding to the negative electrode of the reference battery.

[0082] Referring to FIGS. 2 to 4, the impedance analysis device (10) can generate second Gaussian distribution data including one or more Gaussian distributions (400, 402, 404, 406, 408) based on second reference DRT data (30) corresponding to a specified frequency range (200) included in second reference DRT data (20).

[0083] In one embodiment, the impedance analysis device (10) can identify one or more peak points included in the second reference DRT data (30) corresponding to a specified frequency range (200). The impedance analysis device (10) can generate second Gaussian distribution data including one or more Gaussian distributions (400, 402, 404, 406, 408) based on each of the one or more peak points. For example, the impedance analysis device (10) can generate the first Gaussian distribution (400) such that the x value of the first peak point (P1, 42) matches the median value of the first Gaussian distribution (400).

[0084] Referring to FIG. 5, the impedance analysis device (10) can extract a second parameter for each of the Gaussian distributions (400, 402, 404, 406, 408) included in the second Gaussian distribution data, and the table (50) illustrates the extracted second parameter. Referring to the table (50), the second parameter may include at least one of the median, maximum value, standard deviation, full width at half maximum (FWHM), and area for the second Gaussian distribution (400, 402, 404, 406, 408) corresponding to each of the plurality of peak points (P1, P2, P3, P4, P5).

[0085] In FIGS. 2 to 5, only the method of the impedance analysis device (10) extracting a second parameter based on second reference impedance data corresponding to the negative electrode of the reference battery is described, but this is merely to prevent duplication of description, and the method of the impedance analysis device (10) extracting a first parameter based on first reference impedance data corresponding to the positive electrode of the reference battery may also be the same as the method of extracting the second parameter.

[0086] FIG. 6 is a diagram illustrating a method of fitting first reference DRT data and second reference DRT data to target DRT data according to one embodiment disclosed in this document.

[0087] Referring to FIG. 6, the graph (60) may include first Gaussian distribution data (600) and second Gaussian distribution data (602). Referring to the graph (60), the impedance analysis device (10) can correct at least one of the first parameter and the second parameter corresponding to each of the first Gaussian distribution data (600) and the second Gaussian distribution data (602) to fit the reference DRT data so that it corresponds to the target DRT data (610). The impedance analysis device (10) can generate corrected data by correcting at least one of the first parameter and the second parameter so that the reference DRT data corresponds to the target DRT data (610).

[0088] FIG. 7 is a diagram illustrating a method for separating target DRT data into first target DRT data and second target DRT data according to an embodiment disclosed in this document.

[0089] Referring to FIG. 7, the graph (70) may include target DRT data (610) and fitted reference DRT data (700). Referring to the graph (70), the impedance analysis device (10) may separate the target DRT data (610) into first target DRT data (702) and second target DRT data (704) based on the correction data.

[0090] The impedance analysis device (10) can generate DRT data for each of the positive and negative electrodes of the target battery in a non-destructive manner by using correction data. Additionally, the impedance analysis device (10) can perform a diagnosis for each of the positive and negative electrodes of the target battery by separating the target DRT data (610) into a first target DRT data (702) and a second target DRT data (704), and can diagnose the degree of degradation of the target battery by utilizing the positive impedance and negative impedance.

[0091] FIG. 8 is a flowchart illustrating the operation method of an impedance analysis device for extracting parameters according to an embodiment disclosed in this document.

[0092] Referring to FIG. 8, in operation 800, the impedance analysis device (10) can obtain reference impedance data of a reference battery. The impedance analysis device (10) can obtain reference impedance data including first reference impedance data and second reference impedance data corresponding to each of the positive and negative electrodes of the reference battery.

[0093] In operation 802, the impedance analysis device (10) can convert reference impedance data into reference DRT data. The impedance analysis device (10) can generate reference DRT data by performing DRT conversion on the reference impedance data based on the relaxation time distribution. The impedance analysis device (10) can generate reference DRT data by converting the first reference impedance data and the second reference impedance data, respectively, into the first reference DRT data and the second reference DRT data.

[0094] In operation 804, the impedance analysis device (10) can generate first Gaussian distribution data and second Gaussian distribution data. The impedance analysis device (10) can generate Gaussian distribution data including first Gaussian distribution data including one or more Gaussian distributions and second Gaussian distribution data including one or more Gaussian distributions from first reference DRT data and second reference DRT data.

[0095] In one embodiment, the impedance analysis device (10) can identify a specified frequency range based on reference impedance data. The impedance analysis device (10) can generate first Gaussian distribution data and second Gaussian distribution data based on the specified frequency range.

[0096] In one embodiment, the impedance analysis device (10) can identify one or more peak points included in each of the first reference DRT data and the second reference DRT data. The impedance analysis device (10) can generate first Gaussian distribution data and second Gaussian distribution data based on the peak points included in the first reference DRT data and the peak points included in the second reference DRT data.

[0097] In operation 806, the impedance analysis device (10) can extract one or more parameters corresponding to each of one or more Gaussian distributions included in the first Gaussian distribution data and the second Gaussian distribution data. The impedance analysis device (10) can extract a first parameter corresponding to each of one or more first Gaussian distributions included in the first Gaussian distribution data, and can extract a second parameter corresponding to each of one or more second Gaussian distributions included in the second Gaussian distribution data.

[0098] FIG. 9 is a flowchart illustrating the operation method of an impedance analysis device for separating target DRT data into first target DRT data and second target DRT data according to one embodiment disclosed in this document.

[0099] Referring to FIG. 9, operation 900 may be an operation performed after operation 806 of FIG. 8. However, this is merely for convenience of explanation, and depending on the embodiment, operation 900 may be performed simultaneously with operations 800 to 806 or individually therefrom.

[0100] In operation 900, the impedance analysis device (10) can acquire impedance data of the target battery.

[0101] In operation 902, the impedance analysis device (10) can convert target impedance data into target DRT data. The impedance analysis device (10) can generate target DRT data by performing DRT conversion on the target impedance data.

[0102] In operation 904, the impedance analysis device (10) can generate correction data by correcting at least one value of one or more parameters so that the reference DRT data is fitted to the target DRT data. The impedance analysis device (10) can generate correction data by correcting at least one of the first parameter and the second parameter so that the sum of the first reference DRT data and the second reference DRT data corresponds to the target DRT data. The impedance analysis device (10) can fit the first reference DRT data and the second reference DRT data to the target DRT data by correcting at least one value of the first parameter extracted from the first Gaussian distribution and correcting at least one value of the second parameter extracted from the second Gaussian distribution.

[0103] In operation 906, the impedance analysis device (10) can separate the target DRT data into a first target DRT data and a second target DRT data corresponding to the positive and negative electrodes of the target battery, respectively, based on the correction data.

[0104] In one embodiment, the impedance analysis device (10) can extract a first target DRT data corresponding to the positive electrode of the target battery among the target DRT data based on the correction data, and can separate the target DRT data into the first target DRT data and the second target DRT data by extracting a second target DRT data corresponding to the negative electrode of the target battery among the target DRT data.

[0105] According to an embodiment, after operation 906, the impedance analysis device (10) can diagnose the condition of the target battery based on the first target DRT data and the second target DRT data.

[0106] FIG. 10 illustrates a computing system that performs operations of an impedance analysis device according to an embodiment disclosed in this document.

[0107] Referring to FIG. 10, 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).

[0108] The MCU (1010) may be a processor that executes various programs (e.g., battery diagnostic programs) stored in memory (1020), processes various data from these programs, and performs the functions of the impedance analysis device (10) described in FIGS. 1 to 9.

[0109] The memory (1020) can store various programs regarding the operation of the impedance analysis device (10). In addition, the memory (1020) can store operation data of the impedance analysis device (10).

[0110] 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 memories (1020) listed above are merely examples and are not limited to these examples.

[0111] 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).

[0112] The communication I / F (1040) 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, through the communication I / F (1040), a program for diagnosing abnormalities or various data (e.g., status values) can be transmitted and received from a separately provided external server.

[0113] Terms such as "include," "compose," or "have" as used above, unless specifically stated otherwise, mean that the relevant component may be inherent; therefore, they should be interpreted as allowing for the inclusion of additional components rather than excluding them. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments disclosed in this document pertain, unless otherwise defined. Commonly used terms, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and, unless explicitly defined in this document, should not be interpreted in an ideal or overly formal sense.

[0114] The foregoing description is merely an illustrative explanation of the technical concept disclosed in this document, and a person skilled in the art to which the embodiments disclosed in this document pertain can make various modifications and variations within the scope of the essential characteristics of the embodiments disclosed in this document. Accordingly, the embodiments disclosed in this document are intended to explain, not limit, the technical concept of the embodiments disclosed in this document, and the scope of the technical concept disclosed in this document is not limited by these embodiments. The scope of protection of the technical concept disclosed in this document shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of this document.

Claims

1. An interface for acquiring reference impedance data including first reference impedance data and second reference impedance data corresponding to the positive and negative electrodes of a reference battery, respectively, based on electrochemical impedance spectroscopy (EIS); and Based on the Distribution of Relaxation Times (DRT), reference DRT data is generated by converting the first reference impedance data and the second reference impedance data, respectively, into the first reference DRT data and the second reference DRT data, and Generating first unit distribution data and second unit distribution data that represent each of the above first reference DRT data and the above second reference DRT data as one or more unit distributions, and A controller comprising extracting one or more parameters corresponding to each of the above one or more unit distributions, Impedance analysis device.

2. In Claim 1, The above unit distribution includes a Gaussian distribution, and The above first unit distribution data is first Gaussian distribution data including one or more Gaussian distributions, and The above second unit distribution data is second Gaussian distribution data including one or more Gaussian distributions, Impedance analysis device.

3. In Claim 2, The above controller is, Generating the first Gaussian distribution data and the second Gaussian distribution data based on one or more peak points included in each of the first reference DRT data and the second reference DRT data, Impedance analysis device.

4. In Claim 3, The above one or more parameters include at least one of the center of the peak point, maximum value, standard deviation, full width at half maximum, and area for each of the above one or more Gaussian distributions. Impedance analysis device.

5. In Claim 1, The above interface is, Further acquire target impedance data of the target battery subject to impedance analysis, and The above controller is, Convert the above target impedance data into target DRT data, and Generating correction data by correcting at least one value of the one or more parameters so that the above reference DRT data is fitted to the above target DRT data, Impedance analysis device.

6. In Claim 5, The above controller is, Separating the target DRT data into first target DRT data and second target DRT data corresponding to the positive and negative electrodes of the target battery, respectively, based on the above correction data. Impedance analysis device.

7. In Claim 6, The above controller is, Diagnosing the state of the target battery based on the first target DRT data and the second target DRT data. Impedance analysis device.

8. In Claim 7, The above controller is, Based on the first target DRT data and the second target DRT data, the positive impedance value and the negative impedance value of the target battery are extracted, and Diagnosing the degree of degradation of the target battery based on the ratio of the positive impedance value and the negative impedance value. Impedance analysis device.

9. In Claim 1, The above controller is, Identify a designated frequency range based on the above reference impedance data, and Generating the first unit distribution data and the second unit distribution data based on the specified frequency range, Impedance analysis device.

10. In Claim 9, Each of the above first reference impedance data and the above second reference impedance data includes a first reference Nyquist plot and a second reference Nyquist plot, and The above controller is, Identifying the specified frequency range based on the frequency of the impedance value corresponding to the semicircle included in the first reference Nyquist plot and the second reference Nyquist plot, Impedance analysis device.

11. An operation of acquiring reference impedance data including first reference impedance data and second reference impedance data corresponding to the positive and negative electrodes of a reference battery, respectively, based on electrochemical impedance spectroscopy (EIS); An operation to generate reference DRT data by converting the first reference impedance data and the second reference impedance data, respectively, into the first reference DRT data and the second reference DRT data based on the Distribution of Relaxation Times (DRT); The operation of generating first unit distribution data and second unit distribution data representing each of the first reference DRT data and the second reference DRT data as one or more unit distributions; and The operation of extracting one or more parameters corresponding to each of the above one or more unit distributions, Method of operation of an impedance analysis device.

12. In Claim 11, The above unit distribution includes a Gaussian distribution, and The above first unit distribution data is first Gaussian distribution data including one or more Gaussian distributions, and The above second unit distribution data is second Gaussian distribution data including one or more Gaussian distributions, Method of operation of an impedance analysis device.

13. In Claim 12, The operation of generating the first unit distribution data and the second unit distribution data is, The operation of generating the first Gaussian distribution data and the second Gaussian distribution data based on one or more peak points included in each of the first reference DRT data and the second reference DRT data, Method of operation of an impedance analysis device.

14. In Claim 13, The above one or more parameters include at least one of the center of the peak point, maximum value, standard deviation, full width at half maximum, and area for each of the above one or more Gaussian distributions. Method of operation of an impedance analysis device.

15. In Claim 11, An operation to acquire target impedance data of a target battery subject to impedance analysis; The operation of converting the above target impedance data into target DRT data; and The operation further includes generating correction data by correcting at least one value of the one or more parameters so that the reference DRT data is fitted to the target DRT data. Method of operation of an impedance analysis device.

16. In Claim 15, The operation of further separating the target DRT data into first target data and second target data corresponding to the positive and negative electrodes of the target battery, respectively, based on the correction data above, Method of operation of an impedance analysis device.

17. In Claim 16, A method further comprising diagnosing the state of the target battery based on the first target data and the second target data. Method of operation of an impedance analysis device.

18. In Claim 17, The above-mentioned diagnostic operation is, The operation of extracting the positive impedance and negative impedance of the target battery based on the first target DRT data and the second target DRT data, and A method comprising diagnosing the degree of degradation of the target battery based on the ratio of the positive impedance and the negative impedance. Method of operation of an impedance analysis device.

19. In Claim 12, It further includes an operation to identify a designated frequency range based on the above reference impedance data, and The operation of generating the first unit distribution data and the second unit distribution data is, The operation of generating the first unit distribution data and the second unit distribution data based on the specified frequency range, Method of operation of an impedance analysis device.

20. In Claim 19, Each of the above first reference impedance data and the above second reference impedance data includes a first reference Nyquist plot and a second reference Nyquist plot, and The operation of identifying the above-mentioned specified frequency range is, The method includes an operation of identifying the specified frequency range based on the frequency of the impedance value corresponding to the semicircle included in the first reference Nyquist plot and the second reference Nyquist plot. Method of operation of an impedance analysis device.

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