Battery diagnostic device and method

Abstract

A battery diagnostic device according to an embodiment of the present invention includes: a memory unit configured to store a plurality of battery profiles corresponding to a plurality of cycles and indicating a correspondence relationship between the voltage and the capacity of the battery; and a control unit configured to generate a plurality of correction profiles indicating a correspondence relationship between the voltage and the amount of capacity change based on the plurality of battery profiles, calculate normalization values ​​for the generated correction profiles, and diagnose a battery state based on the calculated normalization values ​​and a preset reference value.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2022-0183779 filed on December 23, 2022, and all the contents disclosed in the specification and drawings of the said application are incorporated into this application.

[0002] The present invention relates to a battery diagnosis apparatus and method, and more particularly, to a battery diagnosis apparatus and method capable of diagnosing the state of a battery.

Background Art

[0003] In recent years, with the rapid growth in the demand for portable electronic products such as notebook computers, video cameras, mobile phones, etc., and the full-scale development of electric vehicles, energy storage batteries, robots, satellites, etc., efforts have been actively made in research on high-performance secondary batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among them, lithium batteries are attracting attention for their advantages of being able to charge and discharge freely because they hardly have a memory effect compared to nickel-based batteries, having a very low self-discharge rate, and having a high energy density.

[0005] Although such batteries are actively researched in terms of increasing capacity and density, the aspects of improving lifespan and safety are also important. In order to improve the safety of batteries, a technology for accurately diagnosing the current state of batteries is desired.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a battery diagnosis apparatus and method that can more accurately diagnose the state of a battery by reflecting long-term trends related to batteries.

[0007] Other objects and advantages of the present invention can be understood from the following description and will be more clearly evident from the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0008] A battery diagnostic device according to one aspect of the present invention includes a storage unit configured to store a plurality of battery profiles corresponding to a plurality of cycles and showing the correspondence between the voltage and capacity of a battery, and a control unit configured to generate a plurality of correction profiles showing the correspondence between the voltage and the amount of change in capacity based on the plurality of battery profiles, calculate normalized values ​​for the plurality of generated correction profiles, and diagnose the state of the battery based on the calculated plurality of normalized values ​​and a preset reference value.

[0009] The control unit may be configured to diagnose the state of the battery as a lithium deposition state if at least one of the plurality of normalized values ​​is equal to or greater than the reference value.

[0010] The control unit may be configured to diagnose the battery state as normal if the plurality of normalized values ​​are less than the reference value.

[0011] The control unit may be configured to calculate a normalized value of the capacitance change amount for a preset voltage interval from each of the plurality of correction profiles.

[0012] The control unit may be configured to calculate the kurtosis of the preset voltage interval as the normalized value for the plurality of correction profiles.

[0013] The control unit may be configured to calculate a standard number of capacitance change values ​​for each voltage in the preset voltage interval from the plurality of correction profiles, and to calculate the kurtosis of each of the plurality of correction profiles based on the standard number of values ​​calculated for each of the plurality of correction profiles.

[0014] The control unit may be configured to select a capacitance change amount corresponding to each of the voltages from the plurality of correction profiles and to calculate a standard number of selected capacitance change amounts for each of the plurality of correction profiles.

[0015] The control unit may be configured to calculate the capacity difference with respect to voltage between a preset reference profile and each of the plurality of battery profiles, calculate the amount of capacity change with respect to voltage for each of the plurality of battery profiles, and generate the plurality of correction profiles according to the calculated amount of capacity change and voltage.

[0016] The control unit may be configured to diagnose the state of the battery based on all battery profiles stored in the storage unit if a new battery profile is further stored in the storage unit.

[0017] A battery pack according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0018] A battery diagnostic method according to yet another aspect of the present invention may include: a storage step of storing a plurality of battery profiles corresponding to a plurality of cycles and showing the correspondence between the voltage and capacity of the battery; a correction profile generation step of generating a plurality of correction profiles showing the correspondence between the voltage and the change in capacity based on the plurality of battery profiles; a normalization value calculation step of calculating normalization values ​​for the plurality of correction profiles that have been generated; and a diagnostic step of diagnosing the state of the battery based on the calculated plurality of normalization values ​​and a preset reference value. [Effects of the Invention]

[0019] According to one aspect of the present invention, a battery diagnostic device can diagnose the state of a battery based on a normalized value for a battery profile corresponding to a plurality of cycles. That is, the battery diagnostic device can diagnose the state of the battery more accurately by reflecting a long-term trend regarding the battery.

[0020] The effects of the present invention are not limited to the above effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0021] The drawings attached to this specification illustrate desirable embodiments of the present invention and serve to further understand the technical idea of the present invention together with the content of the invention. Therefore, the present invention is not to be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0022] [Figure 1] It is a diagram schematically showing a battery diagnostic device according to an embodiment of the present invention. [Figure 2] It is a diagram schematically showing a battery profile for each cycle of a first battery according to an embodiment of the present invention. [Figure 3] It is a diagram schematically showing a correction profile for each cycle of a first battery according to an embodiment of the present invention. [Figure 4] It is a diagram schematically showing a standard score for each cycle of a first battery according to an embodiment of the present invention. [Figure 5] It is a diagram schematically showing the kurtosis for each cycle of a first battery according to an embodiment of the present invention. [Figure 6] It is a diagram schematically showing a battery profile for each cycle of a second battery according to an embodiment of the present invention. [Figure 7] It is a diagram schematically showing a correction profile for each cycle of a second battery according to an embodiment of the present invention. [Figure 8] This figure schematically shows the standard scores for each cycle of a second battery according to one embodiment of the present invention. [Figure 9] This figure schematically shows the cycle-dependent kurtosis of a second battery according to one embodiment of the present invention. [Figure 10] This figure schematically illustrates an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 11] This figure schematically illustrates an exemplary configuration of an automobile according to yet another embodiment of the present invention. [Figure 12] This figure schematically illustrates a battery diagnostic method according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0023] The terms and words used in this specification and in the claims are not to be interpreted in their ordinary or dictionary sense, but rather in a sense and concept corresponding to the technical idea of ​​the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms themselves in order to best describe the invention.

[0024] Therefore, the embodiments described herein and the configurations shown in the drawings represent only preferred embodiments of the present invention and do not represent the entire technical concept of the present invention. It should be understood that there are various equivalent and modified embodiments that can be substituted for these at the time of filing this application.

[0025] Furthermore, in explaining the present invention, if it is deemed that a specific explanation of known technologies related to the present invention may obscure the gist of the present invention, such detailed explanation will be omitted.

[0026] Phrases containing ordinal numbers such as "first," "second," etc., are used to distinguish one of the various constituent elements from the others, and these phrases do not limit the constituent elements.

[0027] When a part of the specification is said to "include" a certain component, unless otherwise specified, this means that it may include other components rather than excluding them.

[0028] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only cases where the parts are "directly connected," but also cases where they are "indirectly connected" with other elements in between.

[0029] In the following, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0030] Figure 1 is a schematic diagram showing a battery diagnostic device 100 according to one embodiment of the present invention.

[0031] Referring to Figure 1, a battery diagnostic device 100 according to one embodiment of the present invention may include a storage unit 110 and a control unit 120.

[0032] Here, a battery refers to a single, independent cell that has a negative terminal and a positive terminal and is physically separable. For example, a lithium-ion battery or a lithium polymer battery can be considered a battery. In the following explanation, for ease of explanation, we will assume that a battery refers to a single, independent cell.

[0033] The memory unit 110 may be configured to store multiple battery profiles that correspond to multiple cycles and show the relationship between the battery voltage and capacity.

[0034] Specifically, the memory unit 110 can store battery profiles acquired in each of multiple cycles. For example, if N cycles are performed, N battery profiles can be stored in the memory unit 110. Here, a cycle may mean a charge-discharge cycle. Preferably, a cycle may mean a charging cycle.

[0035] Figure 2 schematically shows the battery profile of a first battery according to one embodiment of the present invention, broken down by cycle. For example, the battery profile may be represented by an XY graph where the X axis is voltage and the Y axis is capacity.

[0036] The embodiment shown in Figure 2 illustrates multiple battery profiles obtained in each of the first to sixth cycles. For example, the first cycle is 2 cycles, the second cycle is 62 cycles, and the third cycle is 190 cycles. The fourth cycle is 329 cycles, the fifth cycle is 547 cycles, and the sixth cycle is 857 cycles. A battery profile showing the correspondence between the voltage and capacity of the first battery obtained in each cycle can be stored in the storage unit 110.

[0037] The control unit 120 may be configured to generate multiple correction profiles that show the correspondence between voltage and capacity change based on multiple battery profiles.

[0038] Here, the correction profile may be a profile that shows the correspondence between the battery voltage and the change in capacity. That is, the battery profile is a profile relating to voltage and capacity, while the correction profile may be a profile relating to voltage and the change in capacity. In other words, the control unit 120 can calculate the change in capacity from the battery profile and generate a correction profile that shows the correspondence between the calculated change in capacity and the voltage.

[0039] Specifically, the control unit 120 may be configured to calculate the capacity difference with respect to voltage between a preset reference profile and each of the multiple battery profiles, and to calculate the amount of capacity change with respect to voltage for each of the multiple battery profiles.

[0040] Here, the reference profile may be set to a battery profile relating to the battery in its initial (BOL: Beginning of Life) state. For example, the reference profile may be a battery profile theoretically set to reflect the battery's BOL state. Another example is that the reference profile may be the battery profile corresponding to the first cycle among multiple battery profiles stored in the memory unit 110. In the following explanation, we will assume that the battery profile corresponding to the first cycle in the embodiment of Figure 2 is set as the reference profile.

[0041] Specifically, the control unit 120 sets "Q" for each voltage. ij -Q 1j The change in capacitance can be calculated by performing the following calculation: where i is the cycle index and j is the voltage index. ij Q is the capacity corresponding to the voltage j of the battery profile for iCycle, and 1j This is the capacity corresponding to the voltage j of the reference profile. In other words, the control unit 120 can calculate the capacity change by calculating the difference between the capacity of the battery profile and the capacity of the reference profile for each voltage.

[0042] The control unit 120 may be configured to generate multiple correction profiles according to the calculated capacitance change and voltage.

[0043] In the embodiment shown in Figure 2, it is assumed that the battery profile corresponding to the first cycle is the reference profile. The control unit 120 can generate multiple correction profiles by calculating the voltage-dependent capacity differences between the reference profile and each of the battery profiles corresponding to the first to sixth cycles.

[0044] Figure 3 schematically shows the cycle-by-cycle correction profiles of a first battery according to one embodiment of the present invention. For example, the battery profile may be represented by an XY graph where the X axis is voltage and the Y axis is the change in capacity.

[0045] The embodiment in Figure 3 may be multiple correction profiles for multiple battery profiles according to the embodiment in Figure 2. For example, it may be multiple correction profiles generated for multiple battery profiles based on a reference profile (a battery profile corresponding to the first cycle). Here, since the reference profile is set to the battery profile corresponding to the first cycle, in the embodiment of Figure 3, the capacity change amount of the correction profile corresponding to the first cycle may be 0 [Ah].

[0046] The control unit 120 may be configured to calculate normalized values ​​for the multiple correction profiles that have been generated.

[0047] Specifically, the control unit 120 can normalize multiple correction profiles using the mean and standard deviation among the multiple correction profiles. Then, the control unit 120 can calculate a normalized value for the multiple correction profiles according to the normalization result. In other words, the normalized value may be a relative value that can be calculated from the multiple correction profiles.

[0048] Figure 4 is a schematic diagram showing the standard scores for each cycle of a first battery according to one embodiment of the present invention. For ease of explanation, the embodiment in Figure 4 shows the normalized values ​​(standard scores) calculated in a preset voltage interval RV of 3.9[V] to 4.1[V].

[0049] Specifically, the control unit 120 can calculate standard scores for multiple correction profiles. A standard score is a dimensionless numerical value that indicates the position of each case on the standard deviation in a statistically normal distribution, and can also be expressed as a standard value, Z value, or Z score.

[0050] For example, the control unit 120 can calculate a standard score for each capacitance change using the mean and standard deviation among multiple capacitance change amounts (capacitance change amounts of multiple correction profiles for that voltage) for each voltage.

[0051] Note that in the embodiment of Figure 4, the standard points corresponding to the first cycle are excluded. That is, the embodiment of Figure 4 shows the standard points corresponding to the second to sixth cycles. Referring to Figure 4, the standard points corresponding to each cycle can be calculated from each voltage.

[0052] The control unit 120 calculates standard scores for a plurality of correction profiles, and then, based on the calculated standard scores, can calculate the kurtosis for the plurality of correction profiles. Here, kurtosis is a basic statistic that indicates the shape of the distribution and can provide information about the length of the tail portion and the sharpness of the central portion of the distribution.

[0053] The control unit 120 can calculate the kurtosis for each cycle based on a plurality of standard scores calculated for each cycle. For example, the control unit 120 can calculate the kurtosis for each cycle by calculating the average of the fourth powers of the plurality of standard scores calculated. If the standard score is denoted as Z, the kurtosis is E[Z 4 It can be represented as ].

[0054] Figure 5 is a schematic diagram showing the cycle-by-cycle kurtosis of a first battery according to one embodiment of the present invention. The embodiment in Figure 5 shows the kurtosis for all cycles performed on the first battery.

[0055] The control unit 120 may be configured to diagnose the battery status based on a plurality of calculated normalized values ​​and a preset reference value RK.

[0056] Specifically, the reference value RK is a reference value that can determine the state of the battery and can be set based on experimental results for a test cell. For example, the test cell may be a cell that has been induced to deposit lithium metal. Based on the kurtosis of such a test cell, the reference value RK can be determined.

[0057] For example, if at least one of the multiple normalized values ​​is greater than or equal to the reference value RK, the control unit 120 may be configured to diagnose the battery state as a lithium deposition state. In another example, if the multiple normalized values ​​are less than the reference value RK, the control unit 120 may be configured to diagnose the battery state as a normal state.

[0058] For example, in the embodiment shown in Figure 5, the kurtosis of the first battery may be greater than or equal to the reference value RK after approximately 200 cycles. Therefore, the battery diagnostic device 100 can diagnose the state of the first battery as a lithium deposition state.

[0059] A battery diagnostic device 100 according to one embodiment of the present invention can diagnose the state of a battery based on normalized values ​​for a battery profile corresponding to multiple cycles. In other words, the battery diagnostic device 100 can diagnose the state of a battery more accurately by reflecting long-term trends related to the battery.

[0060] On the other hand, the control unit 120 provided in the battery diagnostic device 100 may selectively include processors, application-specific integrated circuits (ASICs), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the industry, in order to activate the various control logics performed in the present invention. Furthermore, when the control logic is implemented by software, the control unit 120 may be implemented by a collection of program modules. In this case, the program modules are stored in memory and can be activated by the control unit 120. The memory may be located inside or outside the control unit 120 and may be connected to the control unit 120 by various well-known means.

[0061] Furthermore, the storage unit 110 can store data and programs necessary for each component of the battery diagnostic device 100 to operate and function, or data generated during the process of operation and functioning. The storage unit 110 is not particularly limited in type, as long as it is a known information storage means capable of recording, erasing, updating, and reading data. For example, information storage means may include random access memory (RAM), flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and registers. The storage unit 110 can also store program code that defines processes that can be executed by the control unit 120.

[0062] Figure 6 is a schematic diagram showing the battery profile of a second battery over several cycles according to one embodiment of the present invention.

[0063] Similar to the embodiment in Figure 2, in the embodiment in Figure 6, the first cycle is 2 cycles, the second cycle is 62 cycles, the third cycle is 190 cycles, the fourth cycle is 329 cycles, the fifth cycle is 547 cycles, and the sixth cycle is 857 cycles.

[0064] The memory unit 110 can store battery profiles for the first to sixth cycles for the second battery.

[0065] Figure 7 schematically shows the cycle-by-cycle correction profiles of a second battery according to one embodiment of the present invention.

[0066] The control unit 120 can generate multiple correction profiles from multiple battery profiles according to the embodiment of Figure 6. The control unit 120 can set the battery profile corresponding to the first cycle in the embodiment of Figure 6 as the reference profile, and generate correction profiles corresponding to the first to sixth cycles based on the reference profile.

[0067] Figure 8 schematically shows the standard points for each cycle of a second battery according to one embodiment of the present invention. Note that, as with the embodiment in Figure 4, the standard points corresponding to the first cycle are excluded in the embodiment in Figure 8.

[0068] The control unit 120 can calculate standard scores for each voltage corresponding to each cycle based on the correction profiles corresponding to the first to sixth cycles of the second battery.

[0069] Figure 9 is a schematic diagram showing the cycle-by-cycle kurtosis of a second battery according to one embodiment of the present invention. Specifically, the embodiment in Figure 9 shows the kurtosis for all cycles performed on the second battery.

[0070] The control unit 120 can compare the reference value RK with multiple kurtosis values ​​of the second battery. Since the kurtosis of the second battery is less than the reference value RK in all cycles, the control unit 120 can diagnose the state of the second battery as normal.

[0071] The control unit 120 may be configured to calculate a normalized value of the capacitance change amount for a preset voltage interval RV from each of the multiple correction profiles. For example, the control unit 120 may be configured to calculate the kurtosis of a preset voltage interval RV as the normalized value for the multiple correction profiles.

[0072] Specifically, the control unit 120 may be configured to calculate the standard score only within a preset voltage interval RV.

[0073] For example, referring to the embodiments in Figures 3 and 7, the first battery, which is in a lithium deposition state, shows an increase in capacity change within a preset voltage interval RV, while the second battery, which is in a normal state, does not show an increase in capacity change within a preset voltage interval RV. In other words, if lithium metal is deposited on the surface of the negative electrode, an abnormal phenomenon occurs in which the capacity change increases within a preset voltage interval RV. Therefore, the control unit 120 can calculate a normalized value for the preset voltage interval RV from the battery profile, taking into account the characteristics of the battery in the lithium deposition state.

[0074] Specifically, the control unit 120 can calculate standard points for each voltage in a preset voltage interval RV of a plurality of correction profiles, and calculate cycle-specific kurtosis according to the calculated standard points.

[0075] The battery diagnostic device 100 has the advantage of efficiently utilizing system resources and quickly diagnosing the battery's condition by diagnosing the battery based on voltage intervals that can distinguish between lithium deposition states and normal states.

[0076] The following describes a specific embodiment in which the control unit 120 calculates kurtosis from each of the multiple correction profiles.

[0077] First, the control unit 120 may be configured to calculate a standard number of capacitance change values ​​for each voltage in a preset voltage interval RV from a plurality of correction profiles.

[0078] Specifically, the control unit 120 may be configured to select a capacitance change amount corresponding to each voltage from a plurality of correction profiles.

[0079] For example, suppose the target voltage is Vj, and the capacitance change rate corresponding to the target voltage is ΔQij, where i is the cycle index and j is the voltage index. In the embodiment shown in Figure 3, the control unit 120 may select ΔQ1j, ΔQ2j, ΔQ3j, ΔQ4j, ΔQ5j, and ΔQ6j from the first to sixth correction profiles.

[0080] The control unit 120 may be configured to calculate standard points for each of the selected capacitance change amounts for each of the multiple correction profiles.

[0081] For example, the control unit 120 can calculate standard scores for the selected ΔQ1j, ΔQ2j, ΔQ3j, ΔQ4j, ΔQ5j, and ΔQ6j. That is, the control unit 120 can calculate standard scores for multiple capacitance change rates at each voltage. Here, a known method is used to calculate the standard scores, so detailed formulas and explanations are omitted here.

[0082] Next, the control unit 120 may be configured to calculate the kurtosis of each of the multiple correction profiles based on the standard score calculated for each of the multiple correction profiles.

[0083] For example, once the calculation of standard points in a preset voltage interval RV for multiple correction profiles is complete, voltage-specific standard points can be set for each cycle. The control unit 120 can calculate the kurtosis of each cycle based on the multiple standard points corresponding to each cycle.

[0084] In the embodiment shown in Figure 4, the control unit 120 can calculate the kurtosis of the fourth cycle based on a plurality of standard points corresponding to the fourth cycle.

[0085] In other words, each standard score is calculated based on the volume change of multiple correction profiles, while kurtosis can be calculated based on the standard score of the relevant cycle.

[0086] The control unit 120 may be configured to diagnose the battery status based on all battery profiles stored in the storage unit 110 if a new battery profile is stored in the storage unit 110.

[0087] The standard score can be calculated based on the capacity changes of multiple correction profiles. That is, if multiple correction profiles are added, the capacity changes that form the basis for calculating the standard score can also be added. In this case, since the cycle-specific standard score for the voltage is calculated based on all the capacity changes, the control unit 120 can re-diagnose the battery state to take into account the trend of changes in the battery state.

[0088] In other words, the battery diagnostic device 100 can more accurately diagnose the battery condition by reflecting long-term trends in the battery, by re-diagnosing the battery condition each time a new battery profile is stored.

[0089] The battery diagnostic device 100 according to the present invention is applicable to a battery management system (BMS). That is, the battery management system (BMS) according to the present invention may include the battery diagnostic device 100 described above. In such a configuration, at least some of the components of the battery diagnostic device 100 can be realized by complementing or adding to the functions of components included in a conventional battery management system (BMS). For example, the storage unit 110 and the control unit 120 of the battery diagnostic device 100 can be realized as components of a battery management system (BMS).

[0090] Furthermore, the battery diagnostic device 100 according to the present invention may be provided on a battery pack. That is, the battery pack according to the present invention may include the above-described battery diagnostic device 100 and one or more battery cells. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a case.

[0091] Figure 10 is a schematic diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention.

[0092] The positive terminal of battery 10 may be connected to the positive terminal P+ of battery pack 1, and the negative terminal of battery 10 may be connected to the negative terminal P- of battery pack 1.

[0093] The measuring unit 20 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measuring unit 20 may be connected to the positive terminal of the battery 10 via the first sensing line SL1 and to the negative terminal of the battery 10 via the second sensing line SL2. The measuring unit 20 may measure the voltage of the battery 10 based on the voltages measured in the first sensing line SL1 and the second sensing line SL2, respectively.

[0094] The measurement unit 20 may be connected to the current measurement unit A via the third sensing line SL3. For example, the current measurement unit A may be an ammeter or shunt resistor capable of measuring the charging current and discharging current of the battery 10. The measurement unit 20 may measure the charging current of the battery 10 via the third sensing line SL3 and calculate the charge amount. The measurement unit 20 may also measure the discharging current of the battery 10 via the third sensing line SL3 and calculate the discharge amount.

[0095] External devices may be connected to the positive terminal P+ and negative terminal P- of the battery pack 1. Here, the external device may be a charging device capable of charging the battery 10, or it may be a load that receives power from the battery 10.

[0096] Figure 11 is a schematic diagram illustrating an exemplary configuration of an automobile 1100 according to yet another embodiment of the present invention.

[0097] Referring to Figure 11, the battery pack 1110 according to an embodiment of the present invention may be included in an automobile 1100 such as an electric vehicle (EV) or a hybrid vehicle (HV). The battery pack 1110 can drive the automobile 1100 by supplying power to a motor via an inverter provided in the automobile 1100. The battery pack 1110 may also include a battery diagnostic device 100.

[0098] Figure 12 is a schematic diagram illustrating a battery diagnostic method according to yet another embodiment of the present invention.

[0099] Preferably, each step of the battery diagnostic method can be performed by the battery diagnostic device 100. For the sake of clarity, the following explanation will omit or simplify any content that overlaps with the above explanation.

[0100] The battery diagnostic method may include a memory step (S100), a correction profile generation step (S200), a normalized value calculation step (S300), and a diagnostic step (S400).

[0101] The memory step (S100) is a step of storing multiple battery profiles that correspond to multiple cycles and show the correspondence between the battery voltage and capacity, and can be performed by the memory unit 110.

[0102] Specifically, the storage unit 110 can store battery profiles acquired in each of multiple cycles. For example, if N cycles are completed, N battery profiles can be stored in the storage unit 110.

[0103] For example, in the embodiment shown in Figure 2, six battery profiles corresponding to the first to sixth cycles can be stored in the storage unit 110.

[0104] The correction profile generation step (S200) is a step of generating multiple correction profiles that show the correspondence between voltage and capacity change based on multiple battery profiles, and can be performed by the control unit 120.

[0105] For example, the control unit 120 may be configured to calculate the capacity difference with respect to voltage between a preset reference profile and each of the multiple battery profiles, and to calculate the amount of capacity change with respect to voltage for each of the multiple battery profiles.

[0106] In the embodiment shown in Figure 2, it is assumed that the battery profile corresponding to the first cycle is the reference profile. The control unit 120 can calculate the voltage-dependent capacity difference between the reference profile and each of the battery profiles corresponding to the first to sixth cycles and generate a plurality of correction profiles. The plurality of generated correction profiles are shown in the embodiment shown in Figure 3.

[0107] The normalization value calculation step (S300) is a step of calculating normalization values ​​for the multiple correction profiles that have been generated, and may be performed by the control unit 120.

[0108] For example, the control unit 120 can normalize multiple correction profiles using the mean and standard deviation among the multiple correction profiles. Then, the control unit 120 can calculate normalized values ​​for the multiple correction profiles according to the normalization results.

[0109] In the embodiment shown in Figure 4, the control unit 120 can calculate standard points for each voltage in each cycle based on a plurality of correction profiles. The control unit 120 can also calculate kurtosis for each cycle, where kurtosis may be a normalized value for each cycle.

[0110] The diagnostic step (S400) is a step of diagnosing the battery status based on a plurality of calculated normalized values ​​and a preset reference value RK, and may be performed by the control unit 120.

[0111] For example, if at least one of the multiple normalized values ​​is greater than or equal to the reference value RK, the control unit 120 may be configured to diagnose the battery state as a lithium deposition state. In another example, if the multiple normalized values ​​are less than the reference value RK, the control unit 120 may be configured to diagnose the battery state as a normal state.

[0112] The embodiments of the present invention described above are not limited to apparatus and methods, but can also be realized through a program that implements the functions corresponding to the configuration of the embodiments of the present invention, or through a recording medium on which such a program is recorded. Such implementation can be easily achieved by experts in the technical field to which the present invention belongs, based on the above-described embodiments.

[0113] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that various modifications and variations can be made by persons with ordinary skill in the art to which the present invention pertains, within the equivalent scope of the technical concept of the present invention and the appended claims.

[0114] Furthermore, the present invention described above can be modified and altered in various ways by a person with ordinary skill in the art to which the present invention belongs, without departing from the technical spirit of the invention. Therefore, it is not limited by the embodiments described above and the accompanying drawings, but rather can be constructed by selectively combining all or part of each embodiment for various modifications. [Explanation of Symbols]

[0115] 1 Battery Pack 10 batteries 20 Measuring part 100 Battery Diagnostic Device 110 Storage section 120 Control Unit 1100 automobile 1110 Battery Pack

Claims

1. A storage unit configured to store multiple battery profiles that correspond to multiple cycles and show the relationship between battery voltage and capacity, A control unit configured to calculate the capacity difference with respect to voltage between a preset reference profile and each of the plurality of battery profiles, calculate the capacity change amount with respect to voltage for each of the plurality of battery profiles, generate a plurality of correction profiles showing the correspondence between voltage and capacity change amount according to the calculated capacity change amount and voltage, calculate normalized values ​​for the generated plurality of correction profiles, and diagnose the state of the battery based on the calculated plurality of normalized values ​​and a preset reference value, Battery diagnostic device, including

2. The control unit, If at least one of the aforementioned normalized values ​​is equal to or greater than the aforementioned reference value, the state of the battery is diagnosed as a lithium deposition state. The battery diagnostic device according to claim 1, wherein the device is configured to diagnose the state of the battery as normal if the plurality of normalized values ​​are less than the reference value.

3. The control unit, The battery diagnostic device according to claim 1, configured to calculate a normalized value of the capacity change amount for a preset voltage interval from each of the plurality of correction profiles.

4. The control unit, The battery diagnostic device according to claim 3, configured to calculate the kurtosis of the preset voltage interval as the normalized value for the plurality of correction profiles.

5. The control unit, The battery diagnostic device according to claim 4, configured to calculate standard points for the amount of change in capacity for each voltage in the preset voltage interval from the plurality of correction profiles, and to calculate the kurtosis of each of the plurality of correction profiles based on the standard points calculated for each of the plurality of correction profiles.

6. The control unit, The battery diagnostic device according to claim 5, configured to select a capacity change amount corresponding to each of the voltages from the plurality of correction profiles and to calculate a standard number of selected capacity change amounts for each of the plurality of correction profiles.

7. The control unit, The battery diagnostic device according to claim 1, further configured to diagnose the state of the battery based on all battery profiles stored in the storage unit when a new battery profile is further stored in the storage unit.

8. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 7.

9. A storage step that stores multiple battery profiles that correspond to multiple cycles and show the relationship between battery voltage and capacity, A correction profile generation step involves calculating the capacity difference with respect to voltage between a pre-set reference profile and each of the multiple battery profiles, calculating the capacity change amount with respect to voltage for each of the multiple battery profiles, and generating multiple correction profiles that show the correspondence between voltage and capacity change amount according to the calculated capacity change amount and voltage. A normalization value calculation step that calculates normalization values ​​for multiple correction profiles generated, A diagnostic step that diagnoses the battery status based on multiple calculated normalized values ​​and pre-set reference values, Battery diagnostic methods, including those mentioned above.

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