Method and apparatus for diagnosing battery

Abstract

A method for diagnosing a battery according to an aspect of the present invention comprises: a voltage determination step of determining an open-circuit voltage of a battery; a capacity selection step of selecting a positive electrode capacity corresponding to the open-circuit voltage from a positive electrode profile showing a corresponding relationship between the positive electrode capacity and a positive electrode voltage of the battery, and selecting a negative electrode capacity corresponding to the open-circuit voltage from a negative electrode profile showing a corresponding relationship between the negative electrode capacity and a negative electrode voltage of the battery; a depth calculation step of calculating a positive electrode depth which is a ratio of the selected positive electrode capacity to a total positive electrode capacity of the battery, and a negative electrode depth which is a ratio of the selected negative electrode capacity to a total negative electrode capacity of the battery; and a diagnosis step of diagnosing the state of the battery on the basis of at least one of the positive electrode depth and the negative electrode depth.

Description

Battery diagnostic method and device

[0001] This application claims priority from Korean Patent Application No. 10-2024-0040392, filed March 25, 2024, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a technology for diagnosing the state of a battery, and more specifically, to a battery diagnosis method and device for effectively diagnosing the deterioration state of a battery that undergoes repeated charging and discharging.

[0003] As the demand for portable electronic products such as laptops, video cameras, and mobile phones that use electricity as a power source increases rapidly, and as mobile robots, electric bicycles, electric carts, electric vehicles, and ESS (Energy Storage Systems) become more widely commercialized, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0004] Currently, commercially available battery types include lithium batteries that utilize lithium ions, such as lithium-ion batteries and lithium-ion polymer batteries, as well as nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. Among these, lithium batteries offer a relatively long lifespan due to minimal memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density. Consequently, their application scope is gradually expanding.

[0005] The positive and negative electrodes of these batteries gradually deteriorate and age as they undergo repeated charge-discharge cycles, losing their performance beyond the beginning of life (BOL). Therefore, accurate diagnosis of battery condition is essential to accurately predict the battery's usable lifespan, remaining service life, and replacement timing.

[0006] However, existing technologies have the problem of not being able to diagnose the battery status for each electrode because they simply diagnose the battery through the SOH (State of Health) of the entire battery.

[0007] The present invention was created to solve the problems described above against the background described above, and the purpose of the present invention is to provide a battery diagnosis method and device that can simply and accurately diagnose the state of a battery by dividing it into electrodes by quantifying the depth and the usage area of ​​each electrode using a profile representing the open circuit voltage and electrical characteristics of the battery.

[0008] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned above will be clearly understood by those skilled in the art from the description of the invention described below.

[0009] A battery diagnosis method according to one aspect of the present invention includes a voltage determination step of determining an open circuit voltage of a battery; a capacity selection step of selecting an anode capacity corresponding to the open circuit voltage from an anode profile indicating a correspondence between a cathode capacity and a cathode voltage of the battery, and a cathode capacity corresponding to the open circuit voltage from an anode profile indicating a correspondence between a cathode capacity and a cathode voltage of the battery; a depth calculation step of calculating an anode depth, which is a ratio of the selected cathode capacity to the total cathode capacity of the battery, and a cathode depth, which is a ratio of the selected cathode capacity to the total cathode capacity of the battery; and a diagnosis step of diagnosing a state of the battery based on at least one of the anode depth and the cathode depth.

[0010] In one embodiment, the voltage determination step may include a step of determining a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery, and the capacity selection step may include a step of selecting, from the positive electrode profile, a positive electrode charge capacity, which is an positive electrode capacity corresponding to the first open circuit voltage, and a positive electrode discharge capacity, which is an positive electrode capacity corresponding to the second open circuit voltage, and the depth calculation step may include a step of calculating, as the positive electrode depth, at least one of a positive electrode charge depth, which is a ratio of the positive electrode charge capacity to the positive electrode total capacity, and a positive electrode discharge depth, which is a ratio of the positive electrode discharge capacity to the positive electrode total capacity.

[0011] In this case, the diagnosis step may include a step of diagnosing whether the positive electrode of the battery is deteriorated based on at least one of the positive electrode charge depth and the positive electrode discharge depth.

[0012] In one embodiment, the voltage determination step may include a step of determining a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery, and the capacity selection step may include a step of selecting, from the negative electrode profile, a negative electrode charge capacity, which is a negative electrode capacity corresponding to the first open circuit voltage, and a negative electrode discharge capacity, which is a negative electrode capacity corresponding to the second open circuit voltage, and the depth calculation step may include a step of calculating, as the negative electrode depth, at least one of a negative electrode charge depth, which is a ratio of the negative electrode charge capacity to the negative electrode total capacity, and a negative electrode discharge depth, which is a ratio of the negative electrode discharge capacity to the negative electrode total capacity.

[0013] In this case, the diagnosis step may include a step of diagnosing whether the negative electrode of the battery is degraded based on at least one of the negative electrode charge depth and the negative electrode discharge depth.

[0014] In one embodiment, the capacity selection step may include: obtaining a battery profile indicating a correspondence between a voltage and a capacity of the battery; adjusting a predetermined reference positive electrode profile and a reference negative electrode profile to correspond to the battery profile to determine the positive electrode profile and the negative electrode profile; and selecting a positive electrode capacity corresponding to the open-circuit voltage from the positive electrode profile and selecting a negative electrode capacity corresponding to the open-circuit voltage from the negative electrode profile.

[0015] In one embodiment, the diagnostic step may include a step of diagnosing whether the positive electrode of the battery is degraded based on the positive electrode depth; and a step of diagnosing whether the negative electrode of the battery is degraded based on the negative electrode depth.

[0016] In one embodiment, the diagnosis step may include a step of diagnosing the state of the battery as a deteriorated state when the positive electrode depth is below a predetermined first reference value, when the negative electrode depth is below a predetermined second reference value, or when the positive electrode depth is below the first reference value and the negative electrode depth is below the second reference value.

[0017] In one embodiment, the battery diagnosis method may further include a step of controlling the usage conditions of the battery when the state of the battery is diagnosed as a deteriorated state.

[0018] According to another aspect of the present invention, a battery diagnosis device includes: a voltage determination unit configured to determine an open circuit voltage of a battery; a selection unit configured to select an anode capacity corresponding to the open circuit voltage from an anode profile indicating a correspondence between a cathode capacity and a cathode voltage of the battery, and to select an anode capacity corresponding to the open circuit voltage from an anode profile indicating a correspondence between a cathode capacity and a cathode voltage of the battery; a calculation unit configured to calculate an anode depth, which is a ratio of the selected cathode capacity to the total cathode capacity of the battery, and a cathode depth, which is a ratio of the selected cathode capacity to the total cathode capacity of the battery; and a diagnosis unit configured to diagnose a state of the battery based on at least one of the anode depth and the cathode depth.

[0019] In one embodiment, the voltage determination unit is configured to determine a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery, the selection unit is configured to select, from the positive electrode profile, a positive electrode charge capacity, which is an positive electrode capacity corresponding to the first open circuit voltage, and a positive electrode discharge capacity, which is an positive electrode capacity corresponding to the second open circuit voltage, and the calculation unit may be configured to calculate, as the positive electrode depth, at least one of a positive electrode charge depth, which is a ratio of the positive electrode charge capacity to the positive electrode total capacity, and a positive electrode discharge depth, which is a ratio of the positive electrode discharge capacity to the positive electrode total capacity.

[0020] In one embodiment, the voltage determination unit is configured to determine a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery, the selection unit is configured to select, from the negative electrode profile, a negative electrode charge capacity, which is a negative electrode capacity corresponding to the first open circuit voltage, and a negative electrode discharge capacity, which is a negative electrode capacity corresponding to the second open circuit voltage, and the calculation unit may be configured to calculate at least one of a negative electrode charge depth, which is a ratio of the negative electrode charge capacity to the negative electrode total capacity, and a negative electrode discharge depth, which is a ratio of the negative electrode discharge capacity to the negative electrode total capacity, as the negative electrode depth.

[0021] In one embodiment, the diagnostic unit may be configured to diagnose whether the positive electrode of the battery is degraded based on the positive electrode depth, and to diagnose whether the negative electrode of the battery is degraded based on the negative electrode depth.

[0022] A battery pack according to another aspect of the present invention may include the battery diagnostic device described above.

[0023] A vehicle according to another aspect of the present invention may include the battery diagnostic device described above.

[0024] According to the present invention, the depth of charge and depth of discharge of the battery according to the progress of the charge / discharge cycle, as well as the unused area of ​​the battery, are quantified by dividing it by electrode, so that the state of deterioration of the battery can be accurately diagnosed by dividing it by electrode.

[0025] In addition, according to the present invention, by using the end-of-charge open circuit voltage (EoC OCV) and end-of-discharge open circuit voltage (EoD OCV) that change according to the deterioration of the battery as diagnostic parameters, changes in the charge characteristics and discharge characteristics of each electrode of the battery can be expressed in quantifiable numbers.

[0026] In addition, according to the present invention, by performing software processing on the cathode profile and anode profile of the battery, the state of the battery can be diagnosed quickly and accurately by providing quantified values ​​for the anode depth and cathode depth corresponding to the open circuit voltage of the battery measured in the current cycle.

[0027] In addition, according to the present invention, by controlling or adjusting the conditions or environment of use of the battery based on data regarding the positive electrode charge depth, positive electrode discharge depth, negative electrode charge depth, and negative electrode discharge depth, it is possible to delay the deterioration of the battery and improve the safety of the battery.

[0028] Furthermore, those skilled in the art will readily understand from the following description that various embodiments of the present invention can solve various technical problems not mentioned above.

[0029] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to more effectively understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to the matters described in these drawings.

[0030] FIG. 1 is a block diagram showing a battery diagnostic device according to one embodiment of the present invention.

[0031] Fig. 2 is a block diagram showing a selection unit of the battery diagnostic device illustrated in Fig. 1.

[0032] Figure 3 is a flowchart illustrating a battery diagnosis method according to one embodiment of the present invention.

[0033] FIG. 4 is a flowchart illustrating a process for determining an unused area of ​​a battery in a battery diagnosis method according to one embodiment of the present invention.

[0034] FIG. 5 is a flowchart showing a process for calculating positive electrode capacity and negative electrode capacity in a battery diagnosis method according to one embodiment of the present invention.

[0035] Figure 6 is a graph showing the change in the battery's charge termination voltage as the number of cycles increases.

[0036] Figure 7 is a graph showing the change in the discharge end voltage of a battery as the number of cycles increases.

[0037] Figure 8 is a drawing showing an example of a positive electrode profile of a battery.

[0038] Figure 9 is a drawing showing an example of a negative electrode profile of a battery.

[0039] Figure 10 is a graph showing changes in the positive charge depth and positive discharge depth of a battery according to an increase in the cumulative driving distance of an electric vehicle using the battery.

[0040] Figure 11 is a graph showing changes in the negative charge depth and negative discharge depth of a battery according to an increase in the cumulative driving distance of an electric vehicle using the battery.

[0041] Figure 12 is a drawing showing an example of a battery profile.

[0042] Figure 13 is a drawing showing an example of a reference anode profile and a reference cathode profile.

[0043] Figure 14 is a drawing showing an example of the positive electrode profile and negative electrode profile of a battery.

[0044] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings to clarify solutions addressing the technical challenges of the present invention. However, if a description of a related known technology obscures the essence of the present invention, the description thereof may be omitted.

[0045] Additionally, the terms used in this specification are defined based on their functions within the present invention, and may vary depending on the intent or custom of the designer, manufacturer, etc. Therefore, the definitions of terms described below should be based on the contents throughout this specification.

[0046] Additionally, throughout this specification, when a part "includes" a component, it does not mean that it excludes other components, but rather that it may include other components.

[0047] Additionally, terms such as processor described in the specification mean a unit that processes at least one function or operation, which may be implemented in hardware, software, or a combination of hardware and software.

[0048] Additionally, throughout the specification, when a part is said to be "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0049] FIG. 1 is a block diagram showing a battery diagnostic device (100) according to one embodiment of the present invention.

[0050] As illustrated in FIG. 1, a battery diagnostic device (100) according to an embodiment of the present invention includes a voltage determination unit (110), a selection unit (120), a calculation unit (130), and a diagnosis unit (140). Depending on the embodiment, the battery diagnostic device (100) according to the present invention may further include at least one of a management control unit (150), an information processing unit (160), an area determination unit (170), and a history information storage unit (180).

[0051] The battery (50) corresponding to the diagnostic target of the present invention may be a battery cell, which is the minimum unit of charging and discharging, or a battery bank, battery module, or battery pack in which a plurality of battery cells are connected in series and / or in parallel.

[0052] Hereinafter, to increase the efficiency of explanation and ease of understanding, the battery (50) is described as meaning a single independent battery cell having a positive electrode and a negative electrode. For example, the battery (50) may be a lithium ion battery or a lithium polymer battery.

[0053] In addition, the battery (50) can be implemented in various forms. For example, the battery (50) can be implemented in a cylindrical type, a prismatic type, or a pouch type.

[0054] Among the components of the battery diagnosis device (100) according to the present invention, the voltage determination unit (110) is configured to determine electrical characteristic values ​​including the open circuit voltage of the target battery (50) through a measuring means electrically connected to the battery to be diagnosed (hereinafter referred to as a "target battery") (50). The measuring means may be implemented as various known measuring means as long as it can measure the open circuit voltage of the target battery (50).

[0055] In order to improve the accuracy of data processing and to more precisely analyze the interrelationship between the positive electrode profile, negative electrode profile, and battery profile of the target battery (50), the voltage determination unit (110) can measure the open circuit voltage (OCV) of the target battery (50).

[0056] As will be explained again below, the above-mentioned positive electrode profile is a profile indicating the correspondence between the positive electrode capacity and the positive electrode voltage (or, positive electrode potential) of the target battery (50). The above-mentioned negative electrode profile is a profile indicating the correspondence between the negative electrode capacity and the negative electrode voltage (or, negative electrode potential) of the target battery (50). The above-mentioned battery profile is a profile indicating the correspondence between the capacity and voltage of the target battery (50).

[0057] The selection unit (120) is configured to select a positive electrode capacity corresponding to the open circuit voltage of the target battery (50) using the positive electrode profile of the target battery (50), and to select a negative electrode capacity corresponding to the open circuit voltage of the target battery (50) using the negative electrode profile of the target battery (50).

[0058] The calculation unit (130) is configured to calculate the anode depth, which is the ratio of the selected anode capacity to the total anode capacity of the target battery (50), and the cathode depth, which is the ratio of the selected cathode capacity to the total cathode capacity of the target battery (50), when the anode capacity and the cathode capacity are each selected by the selection unit (120).

[0059] The diagnostic unit (140) is configured to diagnose the state of the target battery (50) based on at least one of the positive electrode depth and the negative electrode depth.

[0060] For example, the diagnostic unit (140) may be configured to diagnose the state of the target battery (50) as a deteriorated state when the positive electrode depth is below a predetermined first reference value, when the negative electrode depth is below a predetermined second reference value, or when both are present.

[0061] In one embodiment, the battery diagnostic device (100) may further include a management control unit (150). The management control unit (150) may be configured to control the usage conditions of the target battery (50) when the positive electrode depth is below the first reference value, when the negative electrode depth is below the second reference value, or when both are true.

[0062] For example, the management control unit (150) may control a charger that charges the target battery (50) or a discharger that discharges the target battery (50) to limit the current rate for charging or discharging the target battery (50) or reduce the voltage of the target battery (50) when fully charged. According to an embodiment, the management control unit (150) may be configured to control a predetermined cooling device to cool the target battery (50).

[0063] Fig. 2 is a block diagram showing a selection unit (120) of the battery diagnostic device illustrated in Fig. 1.

[0064] As illustrated in FIG. 2, the selection unit (120) may include, as detailed components, a profile acquisition unit (121), a reference storage unit (123), a profile determination unit (125), and a characteristic value selection unit (127).

[0065] The profile acquisition unit (121) is configured to acquire a battery profile (BP) indicating the correspondence between the voltage and capacity (or SOC) of the target battery (50).

[0066] In one embodiment, the profile acquisition unit (121) can measure electrical characteristic values, such as voltage and current, of the target battery (50) using a known measuring means before acquiring the battery profile (BP).

[0067] In this case, the profile acquisition unit (121) can acquire the battery profile (BP) by calculating the capacity or SOC (State of Charge) of the target battery (50) corresponding to the voltage of the target battery (50) based on the measured electrical characteristic values. For example, the battery profile (BP) may be a data set in which the voltage value and capacity value (or SOC) of the target battery (50) measured at the same time are mapped.

[0068] In another embodiment, the profile acquisition unit (121) may acquire the battery profile (BP) by reading out a battery profile (BP) stored in advance in a predetermined memory, or by receiving the battery profile (BP) from a separate device capable of communicating with the battery diagnosis device (100).

[0069] Meanwhile, the SOC of a battery is a parameter that represents the current capacity relative to the maximum capacity as 0 to 1, or 0% to 100%. To generate data on SOC, various techniques and technologies, such as current integration, equivalent circuit models, and Kalman filters, can be applied. Depending on the embodiment, information on SOC may be generated by further reflecting environmental information, such as temperature information.

[0070] The profile determination unit (125) can determine the positive electrode profile and negative electrode profile corresponding to the battery profile (BP) by adjusting a predetermined reference positive electrode profile and a predetermined reference negative electrode profile to correspond to the battery profile (BP).

[0071] The above reference positive electrode profile is a profile indicating the correspondence between the positive electrode capacity and the positive electrode voltage (or, positive electrode potential) of a given reference battery. The above reference negative electrode profile is a profile indicating the correspondence between the negative electrode capacity and the negative electrode voltage (or, negative electrode potential) of the reference battery.

[0072] Here, the reference battery is a battery having the same specifications as the target battery (50), and may be a battery at the beginning of life (BOL) point or an ideal battery according to the design.

[0073] The above-mentioned reference positive electrode profile and the above-mentioned reference negative electrode profile may be curves displayed on a coordinate system having a horizontal axis (X-axis) representing capacity or SOC and a vertical axis (Y-axis) representing voltage, or may be functions or data sets corresponding to these curves.

[0074] In one embodiment, the reference positive electrode profile and the reference negative electrode profile may be generated based on voltage values ​​for each capacity of the positive or negative electrode measured while charging or discharging a three-electrode cell or half-cell, respectively.

[0075] Meanwhile, the above-mentioned reference anode profile and the above-mentioned reference cathode profile may be stored in advance in the reference storage unit (123). In this case, the reference storage unit (123) may be configured to provide the previously stored reference anode profile and reference cathode profile to the profile determination unit (125).

[0076] In addition, the positive electrode profile corresponding to the battery profile (BP) is a profile indicating a correspondence between the positive electrode capacity and the positive electrode voltage (or, positive electrode potential) of the target battery (50). The negative electrode profile corresponding to the battery profile (BP) is a profile indicating a correspondence between the negative electrode capacity and the negative electrode voltage (or, negative electrode potential) of the target battery (50).

[0077] The characteristic value selection unit (127) can select an anode voltage corresponding to the open circuit voltage determined by the voltage determination unit (110) from the anode profile, and select an anode capacity corresponding to the selected anode voltage.

[0078] In addition, the characteristic value selection unit (127) can select a cathode voltage corresponding to the open circuit voltage determined by the voltage determination unit (110) from the cathode profile, and select a cathode capacity corresponding to the selected cathode voltage.

[0079] As a result, the calculation unit (130) can calculate the anode depth, which is the ratio of the selected anode capacity to the total anode capacity of the target battery (50), and the cathode depth, which is the ratio of the selected cathode capacity to the total cathode capacity of the target battery (50), as described above.

[0080] The above-described selection unit (120) can be implemented as a combination of hardware such as a processor, memory, etc., and software such as a program executed by the processor. In this case, the profile acquisition unit (121), reference storage unit (123), profile determination unit (125), and characteristic value selection unit (127) of the selection unit (120) can be considered functionally or logically distinct components rather than physically distinct components.

[0081] Referring again to FIG. 1, the voltage determining unit (110) may be configured to determine a first open voltage, which is an open voltage at the end of charging of the target battery (50), and a second open voltage, which is an open voltage at the end of discharging of the target battery (50).

[0082] After the battery discharge is complete, a rest period of several to several tens of minutes elapses, during which time the polarization within the battery stabilizes. As a result, the voltage between the battery's positive and negative electrodes increases slightly from the voltage at the end of discharge, converging to a voltage value referred to herein as the "End of Discharge OCV" (EoD OCV).

[0083] Accordingly, the voltage determination unit (110) can determine the open circuit voltage of the target battery (50) measured several tens of minutes (e.g., 30 minutes) after the discharge of the target battery (50) is terminated as the open circuit voltage at the end of discharge (EoD OCV). Depending on the embodiment, the open circuit voltage at the end of discharge (EoD OCV) may be estimated from voltage values ​​measured at other points in time based on a known estimation technique.

[0084] In addition, after the charging of the battery is completed, after a rest period of several minutes to several tens of minutes has passed, the voltage between the two terminals of the battery becomes slightly lower than the voltage at the time of completion of charging, and converges to a voltage value referred to herein as the 'end of charge OCV (EoC OCV).

[0085] Accordingly, the voltage determination unit (110) can determine the voltage measured several tens of minutes (e.g., 30 minutes) after the end of charging of the target battery (50) as the open circuit voltage at the end of charging (EoC OCV).

[0086] As will be explained further below, as the number of charge / discharge cycles increases and the battery gradually degrades, the open circuit voltage at the end of charge (EoC OCV) and the open circuit voltage at the end of discharge (EoD OCV) of the battery exhibit time-series changing behavioral characteristics. These behavioral characteristics suggest that the open circuit voltage at the end of charge (EoC OCV) and the open circuit voltage at the end of discharge (EoD OCV) are closely related to the battery degradation.

[0087] The present invention is a technical idea that takes note of such characteristic changes, and uses the open circuit voltage at the end of charging (EoC OCV) and the open circuit voltage at the end of discharging (EoD OCV) as diagnostic parameters, thereby distinguishing the state of deterioration of the battery for each electrode of the battery and accurately diagnosing it with a quantified value.

[0088] To this end, the characteristic value selection unit (127) of the selection unit (120) can select, from the anode profile, the anode charge capacity, which is the anode capacity corresponding to the first open voltage, and the anode discharge capacity, which is the anode capacity corresponding to the second open voltage.

[0089] In addition, the characteristic value selection unit (127) of the selection unit (120) can select, from the cathode profile, the cathode charge capacity, which is the cathode capacity corresponding to the first open-circuit voltage, and the cathode discharge capacity, which is the cathode capacity corresponding to the second open-circuit voltage.

[0090] Then, the calculation unit (130) can calculate at least one of the anode charge depth, which is the ratio of the anode charge capacity to the anode total capacity of the target battery (50), and the anode discharge depth, which is the ratio of the anode discharge capacity to the anode total capacity, as the anode depth.

[0091] In addition, the calculation unit (130) can calculate at least one of the negative electrode charge depth, which is the ratio of the negative electrode charge capacity to the negative electrode total capacity of the target battery (50), and the negative electrode discharge depth, which is the ratio of the negative electrode discharge capacity to the negative electrode total capacity, as the negative electrode depth.

[0092] For example, the total positive electrode capacity of the target battery (50) can be calculated as in mathematical expression 1.

[0093] [Mathematical Formula 1]

[0094] C CT = R C × ps × A C [Ah]

[0095] In the above mathematical expression 1, C CT is the total capacity of the anode, R C is the standard anode capacity per unit area, ps is the shrinkage ratio of the target battery's anode profile with respect to the standard anode profile, A C represents the positive electrode area of ​​the target battery.

[0096] Additionally, the total negative electrode capacity of the target battery (50) can be calculated as in mathematical expression 2.

[0097] [Equation 2]

[0098] C AT = R A × ns × A A [Ah]

[0099] In the above mathematical expression 2, C AT is the total cathode capacity, R A is the reference negative electrode capacity per unit area, ns is the shrinkage ratio of the target battery's negative electrode profile with respect to the reference negative electrode profile, A A represents the cathode area of ​​the target battery.

[0100] In addition, the above-mentioned positive charge depth can be calculated as in mathematical equation 3.

[0101] [Equation 3]

[0102] D CC = (C CC ÷C CT ) × 100 [%]

[0103] In the above mathematical formula 3, D CC is the positive charge depth, C CT is the total capacity of the positive electrode, C CC is the positive charge capacity.

[0104] Additionally, the bipolar discharge depth can be calculated as in mathematical equation 4.

[0105] [Equation 4]

[0106] D CD = (C CD ÷C CT ) × 100 [%]

[0107] In the above mathematical expression 4, D CD is the bipolar discharge depth, C CT is the total capacity of the positive electrode, C CD is the positive discharge capacity.

[0108] Additionally, the negative charge depth can be calculated as in mathematical equation 5.

[0109] [Equation 5]

[0110] D AC = (C AC ÷C AT) × 100 [%]

[0111] In the above mathematical expression 5, D AC is the negative depth of charge, C AT is the total cathode capacity, C AC is the negative charge capacity.

[0112] Additionally, the cathode discharge depth can be calculated as in mathematical equation 6.

[0113] [Equation 6]

[0114] D AD = (C AD ÷C AT ) × 100 [%]

[0115] In the above mathematical expression 6, D AD is the cathodic discharge depth, C AT is the total cathode capacity, C AD is the cathode discharge capacity.

[0116] The diagnostic unit (140) can diagnose the state of the target battery (50) based on at least one of the positive charge depth and positive discharge depth corresponding to the positive depth of the target battery (50) and the negative charge depth and negative discharge depth corresponding to the negative depth of the target battery (50).

[0117] In one embodiment, the diagnostic unit (140) can diagnose whether the positive electrode of the target battery (50) is degraded based on at least one of the positive electrode charge depth and the positive electrode discharge depth of the target battery (50).

[0118] For example, the diagnostic unit (140) can diagnose that the positive electrode of the target battery (50) is deteriorated when the positive electrode charging depth is below a predetermined first charging depth reference value, when the positive electrode discharge depth is below a predetermined first discharge depth reference value, or when both are true.

[0119] In addition, the diagnostic unit (140) can diagnose whether the negative electrode of the target battery (50) is degraded based on at least one of the negative electrode charge depth and negative electrode discharge depth of the target battery (50).

[0120] For example, the diagnostic unit (140) can diagnose that the negative electrode of the target battery (50) is degraded when the negative electrode charge depth is below a predetermined second charge depth reference value, when the negative electrode discharge depth is below a predetermined second discharge depth reference value, or when both are true.

[0121] In one embodiment, the diagnostic unit (140) may be configured to generate diagnostic data indicating a degradation state of the target battery (50) based on at least one of the positive charge depth, the positive discharge depth, the negative charge depth, and the negative discharge depth.

[0122] In one embodiment, the battery diagnostic device (100) according to the present invention may further include an information processing unit (160). In this case, the information processing unit (160) may be configured to provide data regarding the positive electrode total capacity and the negative electrode total capacity of the target battery (50) to the calculation unit (130). To this end, the information processing unit (160) may be configured to store data regarding the positive electrode total capacity and the negative electrode total capacity in advance.

[0123] In another embodiment, the information processing unit (160) may be configured to pre-store the values ​​of the positive electrode total capacity and the negative electrode total capacity at the BOL (Beginning Of Life) time of the target battery (50) as reference values, and to correct the reference values ​​as the number of cycles increases, thereby calculating the values ​​of the positive electrode total capacity and the negative electrode total capacity corresponding to the number of cycles in which diagnosis is performed on the target battery (50).

[0124] For example, the information processing unit (160) may be configured to update the values ​​of the positive electrode total capacity and the negative electrode total capacity of the target battery (50) using the mathematical expressions 1 and 2 when a predetermined number of cycles arrives. For reference, the values ​​of ps among the parameters of mathematical expression 1 and ns among the parameters of mathematical expression 2 may change as the number of cycles increases.

[0125] In one embodiment, the battery diagnostic device (100) according to the present invention may further include a region determination unit (170). In this case, the region determination unit (170) may be configured to determine a first region, which is a region of capacity not included in the positive electrode charge capacity and the positive electrode discharge capacity among the total positive electrode capacity, and to determine a second region, which is a region of capacity not included in the negative electrode charge capacity and the negative electrode discharge capacity among the total negative electrode capacity. In this case, the first region corresponds to an unused region of the positive electrode, and the second region corresponds to an unused region of the negative electrode.

[0126] Once the unused area is determined in this manner, the diagnostic unit (140) can determine whether the size difference between the first area and the second area is greater than or equal to a threshold value. The size difference between the first area and the second area can indicate the difference between the available capacity of the positive electrode and the available capacity of the negative electrode.

[0127] Therefore, if the size difference between the first and second regions is greater than the threshold value, the diagnostic unit (140) can diagnose that the positive and negative poles of the target battery (50) are in an unbalanced state of deterioration.

[0128] In this case, the management control unit (150) can control the usage conditions or usage environment of the target battery (50), such as lowering the current rate for charging and / or discharging the target battery (50) or limiting the upper or lower voltage limit during charging and discharging of the target battery (50).

[0129] In one embodiment, the battery diagnostic device (100) according to the present invention may further include a history information storage unit (180). In this case, the history information storage unit (180) may generate and store history information that interrelates diagnostic data generated by the diagnostic unit (140), identification information of the target battery (50), and information on the time at which the diagnostic data was generated.

[0130] Meanwhile, the battery diagnostic device (100) according to the present invention can be implemented through various combinations of electronic devices and electrical components, such as storage means, operation processing means, input / output means, ASIC, chipset, register, communication modem, etc. Accordingly, the components of the battery diagnostic device (100) illustrated in FIG. 1 should be understood as functionally or logically distinct components rather than physically distinct components.

[0131] That is, since each component of the battery diagnostic device (100) illustrated in FIG. 1 corresponds to a functional configuration for effectively explaining the technical idea according to the present invention, even if each component is separated into subcomponents or integrated with other components, if the corresponding function can be realized, it should be interpreted as being within the scope of the present invention. In addition, if it is a component that performs the same or similar function as a component of the present invention, it should be interpreted as being within the scope of the present invention regardless of whether the names match.

[0132] The battery diagnostic device (100) according to the present invention is a device configured to diagnose the status of a battery (50), and may be configured to be linked with other devices, terminals, servers, etc., depending on the embodiment. In this case, the battery diagnostic device (100) according to the present invention may be configured to generate diagnostic data for a target battery (50) and transmit it to a user terminal, a control server, or an output device of a vehicle.

[0133] FIG. 3 is a flowchart illustrating a battery diagnosis method according to one embodiment of the present invention. Referring to FIG. 3, the functions and operations of the battery diagnosis device (100) described above will be described in chronological order. The battery diagnosis device according to the present invention can be implemented as a combination of a processor and a program executed by the processor. In other words, the battery diagnosis method according to the present invention can be executed by a processor.

[0134] As illustrated in FIG. 3, the voltage determination unit (110) of the battery diagnostic device (100) measures the open circuit voltage of the target battery (50) through a measuring means electrically connected to the target battery (S300).

[0135] In this case, the voltage determination unit (110) can determine the first open voltage, which is the open voltage at the end of charging of the target battery (50), and the second open voltage, which is the open voltage at the end of discharging of the target battery (50).

[0136] Next, the selection unit (120) of the battery diagnostic device (100) selects the positive electrode capacity corresponding to the open circuit voltage of the target battery (50) using the positive electrode profile of the target battery (50), and selects the negative electrode capacity corresponding to the open circuit voltage of the target battery (50) using the negative electrode profile of the target battery (50) (S310).

[0137] The above positive electrode profile is a profile that represents the correspondence between the positive electrode capacity and the positive electrode voltage (or, positive electrode potential) of the target battery (50). The above negative electrode profile is a profile that represents the correspondence between the negative electrode capacity and the negative electrode voltage (or, negative electrode potential) of the target battery (50).

[0138] For example, the selection unit (120) can select, from the anode profile, the anode charge capacity, which is the anode capacity corresponding to the first open voltage, and the anode discharge capacity, which is the anode capacity corresponding to the second open voltage.

[0139] In addition, the selection unit (120) can select, from the cathode profile, the cathode charge capacity, which is the cathode capacity corresponding to the first open-circuit voltage, and the cathode discharge capacity, which is the cathode capacity corresponding to the second open-circuit voltage.

[0140] Next, when the positive electrode capacity and the negative electrode capacity are respectively selected by the selection unit (120), the calculation unit (130) of the battery diagnosis device (100) calculates the positive electrode depth, which is the ratio of the selected positive electrode capacity to the total positive electrode capacity of the target battery (50), and the negative electrode depth, which is the ratio of the selected negative electrode capacity to the total negative electrode capacity of the target battery (50) (S320).

[0141] For example, the calculation unit (130) can calculate at least one of the anode charge depth, which is the ratio of the anode charge capacity to the anode total capacity of the target battery (50), and the anode discharge depth, which is the ratio of the anode discharge capacity to the anode total capacity, as the anode depth.

[0142] In addition, the calculation unit (130) can calculate at least one of the negative electrode charge depth, which is the ratio of the negative electrode charge capacity to the negative electrode total capacity of the target battery (50), and the negative electrode discharge depth, which is the ratio of the negative electrode discharge capacity to the negative electrode total capacity, as the negative electrode depth.

[0143] Next, the diagnostic unit (140) of the battery diagnostic device (100) diagnoses the state of the target battery (50) based on at least one of the positive electrode depth and the negative electrode depth (S330).

[0144] The above diagnostic unit (140) can diagnose the state of the target battery (50) as a deteriorated state when the positive electrode depth is below a predetermined first reference value, when the negative electrode depth is below a predetermined second reference value, or when both are present (S340).

[0145] For example, the above diagnostic unit (140) can diagnose the state of the target battery (50) based on at least one of the above-described positive charge depth, positive discharge depth, negative charge depth, and negative discharge depth.

[0146] In one embodiment, the diagnostic unit (140) can diagnose whether the positive electrode of the target battery (50) is degraded based on at least one of the positive electrode charge depth and the positive electrode discharge depth included in the positive electrode depth of the target battery (50). For example, the diagnostic unit (140) can diagnose that the positive electrode of the target battery (50) is degraded when the positive electrode charge depth is below a predetermined first charge depth reference value, when the positive electrode discharge depth is below a predetermined first discharge depth reference value, or when both are true.

[0147] In addition, the diagnostic unit (140) can diagnose whether the negative electrode of the target battery (50) is degraded based on at least one of the negative electrode depth of charge and the negative electrode depth of discharge included in the negative electrode depth of charge of the target battery (50). For example, the diagnostic unit (140) can diagnose that the negative electrode of the target battery (50) is degraded when the negative electrode depth of charge is lower than or equal to a predetermined second charging depth reference value, when the negative electrode depth of discharge is lower than or equal to a predetermined second discharge depth reference value, or when both are true.

[0148] Next, the management control unit (150) of the battery diagnosis device (100) can control the usage conditions or usage environment of the target battery (50) when the state of the target battery (50) is diagnosed as being in a deteriorated state (S350).

[0149] For example, the management control unit (150) may control a charger that charges the target battery (50) or a discharger that discharges the target battery (50) to limit the current rate for charging or discharging the target battery (50) or reduce the voltage when the target battery (50) is fully charged. Depending on the embodiment, the management control unit (150) may also control a predetermined cooling device to cool the target battery (50).

[0150] The battery diagnostic device (100) may repeat the above-described steps (S300 to S350) until a predetermined termination condition is met (S360). In this case, the termination condition may include a user's termination command, discontinuation of battery use, disconnection of electrical connection with the battery, etc.

[0151] FIG. 4 is a flowchart illustrating a process for determining an unused area of ​​a battery in a battery diagnosis method according to one embodiment of the present invention.

[0152] As illustrated in Fig. 4, the operation unit (130) of the battery diagnostic device (100) selects the positive electrode charge capacity, positive electrode discharge capacity, negative electrode charge capacity, and negative electrode discharge capacity of the target battery (50) described above (S400).

[0153] Next, the area determination unit (170) of the battery diagnostic device (100) selects a first area, which is an area of ​​capacity not included in the positive electrode charge capacity and the positive electrode discharge capacity among the total positive electrode capacity of the target battery (50) (S410).

[0154] In addition, the region determination unit (170) selects a second region, which is a region of capacity that is not included in the negative electrode charge capacity and negative electrode discharge capacity among the total negative electrode capacity of the target battery (50) (S420).

[0155] Since the first and second regions are mutually independent parameters, unlike the example shown in FIG. 4, the step of selecting the second region (S420) may precede the step of selecting the first region (S410), or these steps may be performed simultaneously.

[0156] Next, the region determination unit (170) determines the first region and the second region as unused regions of the target battery (50) (S430).

[0157] When the unused area is determined in this way, the diagnostic unit (140) can determine whether the size difference between the first area and the second area is greater than a predetermined threshold value (S440).

[0158] The size difference between the first and second regions may indicate the difference between the available capacity of the positive electrode and the available capacity of the negative electrode. Accordingly, if the size difference between the first and second regions is greater than a threshold value, the diagnostic unit (140) may diagnose the state of the target battery (50) as a state in which the positive and negative electrodes are unbalanced and deteriorated (S450).

[0159] In this case, the management control unit (150) of the battery diagnostic device (100) can control the usage conditions or usage environment of the target battery (50), such as lowering the current rate for charging and / or discharging the target battery (50) or limiting the voltage when the target battery (50) is fully charged.

[0160] In addition, the history information storage unit (180) of the battery diagnostic device (100) can generate and store history information that interrelates the diagnostic data generated by the diagnostic unit (140), the identification information of the target battery (50), and the time information at which the diagnostic data was generated.

[0161] FIG. 5 is a flowchart showing a process for calculating positive electrode capacity and negative electrode capacity in a battery diagnosis method according to one embodiment of the present invention.

[0162] As illustrated in FIG. 5, the selection unit (120) of the battery diagnostic device (100) measures electrical characteristic values, such as voltage and current, of the target battery (50) using a known measuring means to determine the positive and negative electrode profiles of the target battery (50) (S500).

[0163] Next, the selection unit (120) generates a battery profile indicating a correspondence between the capacity (or SOC) and voltage of the target battery (50) based on the measured electrical characteristic values ​​(S510). In this case, the battery profile may be a data set in which the voltage value and capacity value (or SOC value) of the target battery (50) measured at the same time are mapped.

[0164] Next, the selection unit (120) adjusts a predetermined reference positive electrode profile and a predetermined reference negative electrode profile to correspond to the battery profile, thereby determining the positive electrode profile and negative electrode profile of the target battery (50) (S520).

[0165] As previously explained, the reference positive electrode profile is a profile indicating the correspondence between the positive electrode capacity and the positive electrode voltage (or, positive electrode potential) of a given reference battery. The reference negative electrode profile is a profile indicating the correspondence between the negative electrode capacity and the negative electrode voltage (or, negative electrode potential) of the reference battery.

[0166] Here, the reference battery is a battery having the same specifications as the target battery (50), and may be a battery at the beginning of life (BOL) point or an ideal battery according to the design.

[0167] The above-mentioned reference positive electrode profile and the above-mentioned reference negative electrode profile may be curves displayed on a coordinate system having a horizontal axis (X-axis) representing capacity or SOC and a vertical axis (Y-axis) representing voltage, or may be functions or data sets corresponding to these curves.

[0168] In addition, the positive electrode profile of the target battery (50) is a profile that represents the correspondence between the positive electrode capacity and the positive electrode voltage (or, positive electrode potential) of the target battery (50). The negative electrode profile of the target battery (50) is a profile that represents the correspondence between the negative electrode capacity and the negative electrode voltage (or, negative electrode potential) of the target battery (50).

[0169] Next, the selection unit (120) selects, from the positive electrode profile, the positive electrode capacity corresponding to the first open circuit voltage, which is the open circuit voltage after the charge type of the target battery (50), as the positive electrode charge capacity, and selects, from the positive electrode profile, the positive electrode capacity corresponding to the second open circuit voltage, which is the open circuit voltage after the determined discharge type of the target battery (50), as the positive electrode discharge capacity (S530).

[0170] In addition, the selection unit (120) selects the negative electrode capacity corresponding to the first open-circuit voltage as the negative electrode charge capacity in the negative electrode profile, and selects the negative electrode capacity corresponding to the second open-circuit voltage as the negative electrode discharge capacity (S530).

[0171] As a result, the calculation unit (130) of the battery diagnosis device (100) can calculate the positive electrode depth, which is the ratio of the selected positive electrode capacity to the total positive electrode capacity of the target battery (50), and the negative electrode depth, which is the ratio of the selected negative electrode capacity to the total negative electrode capacity of the target battery (50), as described above.

[0172] Meanwhile, embodiments according to the present invention can be implemented as a computer system and a computer program that drives such a computer system. When embodiments of the present invention are implemented as a computer program, the components of the present invention may include program segments that execute corresponding operations or tasks through the computer system. Such computer programs or program segments may be stored on various computer-readable recording media. Computer-readable recording media may include any type of media that records data that can be read by a computer system. For example, computer-readable recording media may include ROM, RAM, EEPROM, registers, flash memory, CD-ROM, magnetic tape, hard disk, floppy disk, or optical data recording devices. Furthermore, such recording media may be distributed across computer systems connected via various communication networks to store or execute program codes in a distributed manner.

[0173] Figure 6 is a graph showing the change in the battery's charge termination voltage as the number of cycles increases.

[0174] Figure 6 shows the change characteristics of the open circuit voltage at the end of charging (EoC OCV) in the first case where the charge / discharge SOC range is set to 0 to 100 (%), the second case where it is set to 20 to 100 (%), and the third case where it is set to 40 to 100 (%).

[0175] Also, in Fig. 6, V1 represents the open circuit voltage (EoC OCV) at the end of charging of the target battery (50) that has undergone 100 cycles.

[0176] Figure 7 is a graph showing the change in the discharge end voltage of a battery as the number of cycles increases.

[0177] Figure 7 shows the change characteristics of the open circuit voltage at the end of discharge (EoD OCV) in the first case where the charge / discharge SOC range is set to 0 to 100 (%), the second case where it is set to 20 to 100 (%), and the third case where it is set to 40 to 100 (%).

[0178] Also, in Fig. 7, V2 represents the open circuit voltage (EoD OCV) at the end of discharge of the target battery (50) that has undergone 100 cycles.

[0179] As illustrated in FIGS. 6 and 7, the open circuit voltage at the end of charge (EoC OCV) and the open circuit voltage at the end of discharge (EoD OCV) of the battery have behavioral characteristics that change over time as the number of cycles increases and the battery deteriorates. These behavioral characteristics suggest that the open circuit voltage at the end of charge (EoC OCV) and the open circuit voltage at the end of discharge (EoD OCV) are closely related to the deterioration of the battery.

[0180] The present invention is a technical idea that takes note of such characteristic changes, and by using the open circuit voltage at the end of charge (EoC OCV) and the open circuit voltage at the end of discharge (EoD OCV) as parameters, the degradation of the battery, specifically the degradation of the charging characteristics and the degradation of the discharge characteristics of each electrode of the battery, can be accurately diagnosed by separating them into quantifiable figures.

[0181] Figure 8 is a drawing showing an example of a positive electrode profile of a battery.

[0182] In Fig. 8, the voltage indicated as V1p is the voltage of the positive electrode corresponding to the first open circuit voltage (V1) (hereinafter referred to as the 'first positive electrode voltage'), and the capacity of the positive electrode corresponding to the first positive electrode voltage (V1p) in the positive electrode profile of the target battery (50) is the positive electrode charge capacity (C CC ) corresponds to.

[0183] In addition, in Fig. 8, the voltage indicated as V2p is the voltage of the positive electrode corresponding to the second open circuit voltage (V2) (hereinafter referred to as the 'second positive electrode voltage'), and the capacity of the positive electrode corresponding to the second positive electrode voltage (V2p) in the positive electrode profile of the target battery (50) is the positive electrode discharge capacity (C CD ) corresponds to.

[0184] Figure 9 is a drawing showing an example of a negative electrode profile of a battery.

[0185] In Fig. 9, the voltage indicated as V1n is the voltage of the negative electrode corresponding to the first open circuit voltage (V1) (hereinafter referred to as the 'first negative electrode voltage'), and the capacity of the negative electrode corresponding to the first negative electrode voltage (V1n) in the negative electrode profile of the target battery (50) is the negative electrode charge capacity (C AC ) corresponds to.

[0186] In addition, in Fig. 9, the voltage indicated as V2n is the voltage of the cathode corresponding to the second open circuit voltage (V2) (hereinafter referred to as the 'second cathode voltage'), and the capacity of the cathode corresponding to the second cathode voltage (V2n) in the cathode profile of the target battery (50) is the cathode discharge capacity (C AD ) corresponds to.

[0187] Figure 10 is a graph showing changes in the positive charge depth and positive discharge depth of a battery according to an increase in the cumulative driving distance of an electric vehicle using the battery.

[0188] In Fig. 10, three lines (Lc1 to Lc3) shown in a mutually overlapping form in the upper part represent the anode charge depth, and three lines (Lc4 to Lc6) shown in the lower part represent the anode discharge depth.

[0189] In addition, among the above lines (Lc1 to Lc6), Lc1 and Lc4 are cases where the charge / discharge SOC range is set to 40 to 100 (%), Lc2 and Lc4 are cases where the charge / discharge SOC range is set to 20 to 100 (%), and Lc3 and Lc6 are cases where the charge / discharge SOC range is set to 0 to 100 (%).

[0190] Figure 11 is a diagram showing changes in the negative electrode charge depth and negative electrode discharge depth of a battery according to an increase in the cumulative driving distance of an electric vehicle using the battery.

[0191] In Fig. 11, three lines (La1 to La3) shown in a mutually overlapping form in the upper part represent the negative electrode charge depth, and three lines (La4 to La6) shown in the lower part represent the negative electrode discharge depth.

[0192] Among the above lines (La1 to La6), La1 and La4 are cases in which the charge / discharge SOC range is set to 40 to 100 (%), La2 and La4 are cases in which the charge / discharge SOC range is set to 20 to 100 (%), and La3 and La6 are cases in which the charge / discharge SOC range is set to 0 to 100 (%).

[0193] The horizontal axis of FIGS. 10 and 11 represents the cumulative capacity provided by the battery as the number of charge / discharge cycles of the battery increases, converted into a cumulative driving distance of the electric vehicle.

[0194] As shown in FIGS. 10 and 11, the positive electrode depth of charge, positive electrode depth of discharge, negative electrode depth of charge, and negative electrode depth of discharge of the battery generally show a decreasing trend as the number of cycles increases.

[0195] However, as illustrated in Fig. 11, the negative discharge depth (La6) may exhibit an increasing trend as the number of cycles increases. In this case, the diagnostic unit (140) of the battery diagnostic device (100) may diagnose the state of the battery based on whether the negative discharge depth (La6) exceeds a predetermined reference value or is correlated with the negative charge depth (La3).

[0196] Figure 12 is a diagram showing an example of a battery profile (BP).

[0197] In Fig. 12, the horizontal axis (X-axis) represents the capacity of the target battery (50), and the vertical axis (Y-axis) represents the voltage of the target battery (50).

[0198] As described with reference to FIG. 2, the profile determination unit (125) of the selection unit (120) can determine the positive electrode profile and negative electrode profile of the target battery (50) by adjusting a predetermined reference positive electrode profile and a predetermined reference negative electrode profile to correspond to the battery profile (BP).

[0199] Figure 13 is a drawing showing an example of a reference positive electrode profile (Rp) and a reference negative electrode profile (Rn).

[0200] As illustrated in Figure 13, the reference positive electrode profile (Rp) is a profile indicating the correspondence between the positive electrode capacity and the positive electrode voltage (or, positive electrode potential) of a given reference battery. In addition, the reference negative electrode profile (Rn) is a profile indicating the correspondence between the negative electrode capacity and the negative electrode voltage (or, negative electrode potential) of a given reference battery.

[0201] In this case, when the reference positive electrode profile (Rp) and the reference negative electrode profile (Rn) are combined, a reference battery profile (R) representing the correspondence between the capacity and voltage of the reference battery can be generated. That is, the reference battery profile (R) can be generated by calculating the voltage difference for each capacity between the reference positive electrode profile (Rp) and the reference negative electrode profile (Rn) in a capacity range corresponding to the SOC range from 0(%) to 100(%).

[0202] Meanwhile, the profile determination unit (125) can generate an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting the position or shape of the reference positive electrode profile (Rp) and the reference negative electrode profile (Rn), and can generate a comparison profile corresponding to the battery profile (BP) of the target battery (50) by mutually combining the adjusted positive electrode profile and the adjusted negative electrode profile.

[0203] For example, the profile determination unit (125) can generate a plurality of comparison profiles of different shapes by repeating the adjustment process and combination process for the reference positive electrode profile (Rp) and the reference negative electrode profile (Rn).

[0204] The above adjustment process may include at least one of shift, scaling, shrinkage and offset adjustment with respect to a reference anode profile (Rp) and / or a reference cathode profile (Rn).

[0205] Next, the profile determination unit (125) selects a comparison profile among the plurality of comparison profiles that has the smallest error with the battery profile (BP), and determines the adjusted positive electrode profile and the adjusted negative electrode profile used to generate the selected comparison profile as the positive electrode profile (PP) and negative electrode profile (NP) of the target battery (50) (S520).

[0206] In this way, the present invention can diagnose a target battery in a non-destructive manner by generating an anode profile and a cathode profile that estimate the current state of the target battery based on a reference anode profile and a reference cathode profile.

[0207] Figure 14 is a drawing showing an example of a positive electrode profile (PP) and a negative electrode profile (NP) of a battery.

[0208] As illustrated in Fig. 14, the positive electrode profile (PP) and negative electrode profile (NP) of the target battery (50) can be determined by the profile determination unit (125) (S520).

[0209] Then, the characteristic value selection unit (127) of the selection unit (120) selects the first positive electrode voltage (V1p) and the second positive electrode voltage (V2p) corresponding to the first open circuit voltage (V1) and the second open circuit voltage (V2) of the battery profile (BP) from the positive electrode profile (PP) of the target battery (50), and selects the positive electrode charge capacity (C) corresponding to the first positive electrode voltage (V1p). CC ) and the anode discharge capacity (C), which is the capacity corresponding to the second anode voltage (V2p). CD ) can be selected.

[0210] In addition, the characteristic value selection unit (127) selects the first negative voltage (V1n) and the second negative voltage (V2n) corresponding to the first open voltage (V1) and the second open voltage (V2) of the battery profile (BP) from the negative profile (NP) of the target battery (50), and selects the negative charge capacity (C) corresponding to the first negative voltage (V1n). AC ) and the cathode discharge capacity (C), which is the capacity corresponding to the second cathode voltage (V2n). AD ) can be selected.

[0211] In one embodiment, the battery diagnostic device according to the present invention may be included in a Battery Management System (BMS) that manages a battery module or battery pack. That is, a BMS according to another aspect of the present invention includes the battery diagnostic device according to the present invention.

[0212] According to another aspect of the present invention, a battery pack comprises at least one battery and a battery diagnostic device according to the present invention. In this case, each battery included in the battery pack may be a battery cell, which is a basic unit of charging and discharging, or a battery module comprising multiple battery cells connected in series and / or parallel.

[0213] According to another aspect of the present invention, a vehicle includes at least one battery and a battery diagnostic device according to the present invention. In this case, each battery included in the vehicle may be a battery module comprising multiple battery cells connected in series and / or parallel, or a battery pack comprising multiple battery cells or multiple battery modules connected in series and / or parallel. The vehicle may further include an electric motor, an electronic control unit (ECU) for controlling the electric motor, and the like.

[0214] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0215] The drawings attached for the purpose of explaining the present invention and illustrating embodiments thereof may be illustrated in a somewhat exaggerated form to emphasize or highlight the technical contents according to the present invention. However, it should be interpreted that it is obvious that various modified application examples may be possible at the level of a person skilled in the art in consideration of the contents described above and matters illustrated in the drawings.

[0216] In addition, terms such as 'first', 'second', etc. used in describing the present invention are merely terms used to relatively distinguish components, and are not terms used to limit the order between components.

[0217] [Explanation of symbols]

[0218] 50: Battery 100: Battery Diagnostic Device

[0219] 110: Voltage determination unit 120: Selection unit

[0220] 121: Profile acquisition section 123: Reference storage section

[0221] 125: Profile determination unit 127: Feature value selection unit

[0222] 130: Operation section 140: Diagnostic section

[0223] 150: Management Control Unit 160: Information Processing Unit

[0224] 170: Area determination unit 180: History information storage unit

Claims

1. Voltage determination step that determines the open circuit voltage of the battery; A capacity selection step of selecting a positive electrode capacity corresponding to the open-circuit voltage from a positive electrode profile showing a correspondence between the positive electrode capacity and the positive electrode voltage of the battery, and selecting a negative electrode capacity corresponding to the open-circuit voltage from a negative electrode profile showing a correspondence between the negative electrode capacity and the negative electrode voltage of the battery; A depth calculation step for calculating the anode depth, which is the ratio of the selected anode capacity to the total anode capacity of the battery, and the cathode depth, which is the ratio of the selected cathode capacity to the total cathode capacity of the battery; and A battery diagnosis method, characterized in that it includes a diagnosis step of diagnosing the state of the battery based on at least one of the positive electrode depth and the negative electrode depth.

2. In paragraph 1, The above voltage determination step is, It includes a step of determining a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery. The above capacity selection step is, In the above bipolar profile, a step of selecting a bipolar charge capacity corresponding to the first open-circuit voltage and a bipolar discharge capacity corresponding to the second open-circuit voltage is included, The above depth calculation step is, A battery diagnosis method characterized by including a step of calculating at least one of the anode charge depth, which is a ratio of the anode charge capacity to the anode total capacity, and the anode discharge depth, which is a ratio of the anode discharge capacity to the anode total capacity, as the anode depth.

3. In paragraph 2, The above diagnostic steps are: A battery diagnosis method, characterized in that it includes a step of diagnosing whether the positive electrode of the battery is deteriorated based on at least one of the positive electrode charge depth and the positive electrode discharge depth.

4. In paragraph 1, The above voltage determination step is, It includes a step of determining a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery. The above capacity selection step is, In the above cathode profile, a step of selecting a cathode charge capacity corresponding to the first open-circuit voltage and a cathode discharge capacity corresponding to the second open-circuit voltage is included, The above depth calculation step is, A battery diagnosis method characterized by including a step of calculating at least one of a negative electrode charge depth, which is a ratio of the negative electrode charge capacity to the negative electrode total capacity, and a negative electrode discharge depth, which is a ratio of the negative electrode discharge capacity to the negative electrode total capacity, as the negative electrode depth.

5. In paragraph 4, The above diagnostic steps are: A battery diagnosis method, characterized in that it includes a step of diagnosing whether the negative electrode of the battery is degraded based on at least one of the negative electrode charge depth and the negative electrode discharge depth.

6. In paragraph 1, The above capacity selection step is, A step of obtaining a battery profile indicating a correspondence between the voltage and capacity of the battery; A step of determining the positive electrode profile and the negative electrode profile by adjusting a predetermined reference positive electrode profile and a reference negative electrode profile to correspond to the above battery profile; and A battery diagnosis method characterized by including a step of selecting a positive electrode capacity corresponding to the open-circuit voltage from the positive electrode profile and selecting a negative electrode capacity corresponding to the open-circuit voltage from the negative electrode profile.

7. In paragraph 1, The above diagnostic steps are: A step of diagnosing whether the positive electrode of the battery is deteriorated based on the above-mentioned bipolar depth; and A battery diagnosis method, characterized in that it includes a step of diagnosing whether the negative electrode of the battery is degraded based on the negative electrode depth.

8. In paragraph 1, The above diagnostic steps are: A battery diagnosis method characterized by comprising a step of diagnosing the state of the battery as a deteriorated state when the positive electrode depth is below a first predetermined reference value, when the negative electrode depth is below a second predetermined reference value, or when the positive electrode depth is below the first reference value and the negative electrode depth is below the second reference value.

9. In paragraph 1, A battery diagnosis method characterized in that it further includes a step of controlling the usage conditions of the battery when the state of the battery is diagnosed as a deteriorated state.

10. A voltage determining unit configured to determine the open circuit voltage of the battery; A selection unit configured to select a positive electrode capacity corresponding to the open-circuit voltage from a positive electrode profile showing a correspondence between a positive electrode capacity and a positive electrode voltage of the battery, and to select a negative electrode capacity corresponding to the open-circuit voltage from a negative electrode profile showing a correspondence between a negative electrode capacity and a negative electrode voltage of the battery; A calculation unit configured to calculate the anode depth, which is the ratio of the selected anode capacity to the total anode capacity of the battery, and the cathode depth, which is the ratio of the selected cathode capacity to the total cathode capacity of the battery; and A battery diagnostic device characterized by including a diagnostic unit configured to diagnose the state of the battery based on at least one of the positive electrode depth and the negative electrode depth.

11. In paragraph 10, The above voltage determining unit, It is configured to determine a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery. The above selection section, In the above bipolar profile, it is configured to select the bipolar charge capacity, which is the bipolar capacity corresponding to the first open-circuit voltage, and the bipolar discharge capacity, which is the bipolar capacity corresponding to the second open-circuit voltage, The above operation unit, A battery diagnostic device characterized in that it is configured to calculate at least one of the anode charge depth, which is the ratio of the anode charge capacity to the anode total capacity, and the anode discharge depth, which is the ratio of the anode discharge capacity to the anode total capacity, as the anode depth.

12. In paragraph 10, The above voltage determining unit, It is configured to determine a first open circuit voltage, which is an open circuit voltage at the end of charging of the battery, and a second open circuit voltage, which is an open circuit voltage at the end of discharging of the battery. The above selection section, In the above cathode profile, the cathode charge capacity corresponding to the first open-circuit voltage and the cathode discharge capacity corresponding to the second open-circuit voltage are selected, The above operation unit, A battery diagnostic device characterized in that it is configured to calculate at least one of a negative electrode charge depth, which is a ratio of the negative electrode charge capacity to the negative electrode total capacity, and a negative electrode discharge depth, which is a ratio of the negative electrode discharge capacity to the negative electrode total capacity, as the negative electrode depth.

13. In paragraph 10, The above diagnostic section, A battery diagnostic device characterized in that it is configured to diagnose whether the positive electrode of the battery is deteriorated based on the positive electrode depth, and to diagnose whether the negative electrode of the battery is deteriorated based on the negative electrode depth.

14. A battery pack comprising a battery diagnostic device according to any one of claims 10 to 13.

15. A vehicle comprising a battery diagnostic device according to any one of claims 10 to 13.

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