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, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof.

[0002] The present invention relates to a battery diagnostic device and method, and more particularly to a battery diagnostic device and method capable of diagnosing the state of a battery. [Background technology]

[0003] In recent years, the demand for portable electronic products such as laptop computers, video cameras, and mobile phones has grown rapidly, and the development of electric vehicles, energy storage batteries, robots, satellites, and other products has progressed in earnest. As a result, there has been active research into 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, and lithium batteries. Among these, lithium batteries are attracting attention due to their advantages of being able to be freely charged and discharged since they have almost no memory effect compared to nickel-based batteries, as well as their extremely low self-discharge rate and high energy density.

[0005] While active research is being conducted on these batteries from the viewpoints of increasing capacity and density, improving lifespan and safety are also important. To improve battery safety, a technology that can accurately diagnose the current state of the battery is desired. Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a battery diagnostic device and method that reflects long-term trends related to a battery and more accurately diagnoses the state of the battery.

[0007] Other objects and advantages of the present invention will become apparent from the following description and the embodiments of the present invention, and 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 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 capacity of a battery; and a control unit configured to generate a plurality of correction profiles indicating a correspondence relationship between the voltage and capacity change amount based on the plurality of battery profiles, calculate normalization values ​​for the generated plurality of correction profiles, and diagnose the state of the battery based on the calculated plurality of normalization 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, as the normalized value, a kurtosis of the preset voltage interval for the plurality of correction profiles.

[0013] The control unit may be configured to calculate standard scores of capacitance change amounts for each voltage in the predetermined voltage range from the plurality of correction profiles, and to calculate the kurtosis of each of the plurality of correction profiles based on the standard scores calculated for each of the plurality of correction profiles.

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

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

[0016] The control unit may be configured to, if a new battery profile is further stored in the storage unit, diagnose the state of the battery based on all battery profiles 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 indicating the correspondence between the voltage and the capacity of the battery; a correction profile generation step of generating a plurality of correction profiles indicating the correspondence between the voltage and the amount of capacity change based on the plurality of battery profiles; a normalization value calculation step of calculating normalization values ​​for the plurality of generated correction profiles; and a diagnosis 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 a battery state based on a normalized value for a battery profile corresponding to a plurality of cycles. That is, the battery diagnostic device can more accurately diagnose the battery state by reflecting a long-term trend of the battery.

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

[0021] The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical concepts of the present invention as well as the content of the invention, and therefore the present invention should not be interpreted as being limited to only the matters depicted in the drawings. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram illustrating a battery diagnostic device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram schematically illustrating a battery profile for each cycle of a first battery according to an embodiment of the present invention. [Figure 3] FIG. 2 is a diagram illustrating a cycle-by-cycle correction profile of a first battery according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram illustrating a standard score for each cycle of a first battery according to an embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating the kurtosis of a first battery according to an embodiment of the present invention for each cycle. [Figure 6] FIG. 10 is a diagram schematically illustrating a battery profile for each cycle of a second battery according to an embodiment of the present invention. [Figure 7] FIG. 10 is a diagram illustrating a cycle-by-cycle correction profile of a second battery according to an embodiment of the present invention. [Figure 8] FIG. 10 is a diagram illustrating a standard score for each cycle of a second battery according to an embodiment of the present invention. [Figure 9] FIG. 10 is a diagram illustrating the kurtosis of a second battery according to an embodiment of the present invention for each cycle. [Figure 10] FIG. 10 is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 11] FIG. 10 is a diagram illustrating a schematic diagram of an exemplary configuration of a vehicle according to yet another embodiment of the present invention. [Figure 12] 10 is a diagram illustrating a battery diagnostic method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventor can appropriately define the concepts of terms himself / herself in order to best explain the invention.

[0024] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalent and modified embodiments that can be substituted for them at the time of this application.

[0025] Furthermore, in describing the present invention, if it is recognized that a specific description of known technology related to the present invention may obscure the gist of the present invention, the detailed description will be omitted.

[0026] Phrases including ordinal numbers such as first and second are used to distinguish one of various components from the other components, and do not limit the components.

[0027] Throughout this specification, when a part is said to "comprise" a certain element, this does not mean that it may further include other elements, unless otherwise specified.

[0028] Furthermore, throughout this specification, when a part is said to be "connected (coupled)" to another part, this includes not only the case where it is "directly connected (coupled)" but also the case where it is "indirectly connected (coupled)" with another element in between.

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] FIG. 1 is a diagram schematically illustrating a battery diagnostic device 100 according to an embodiment of the present invention.

[0031] Referring to FIG. 1, a battery diagnostic device 100 according to an 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 can be physically separated. For example, a lithium ion battery or a lithium polymer battery can be considered a battery. For ease of explanation, the following description will be made assuming that a battery refers to a single independent cell.

[0033] The storage unit 110 may be configured to store a plurality of battery profiles corresponding to a plurality of cycles and indicating a correspondence between the voltage and capacity of the battery.

[0034] Specifically, the storage unit 110 may store battery profiles acquired in each of a plurality of cycles. For example, if N cycles have been performed, N battery profiles may be stored in the storage unit 110. Here, a cycle may refer to a charge / discharge cycle. Preferably, a cycle may refer to a charge cycle.

[0035] 2 is a diagram illustrating a battery profile for each cycle of a first battery according to an embodiment of the present invention. For example, the battery profile may be represented by an XY graph in which the X axis represents voltage and the Y axis represents capacity.

[0036] 2 shows a plurality of battery profiles acquired in each of the first to sixth cycles. For example, 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. The battery profiles indicating the correspondence between the voltage and capacity of the first battery acquired in each cycle can be stored in the memory unit 110.

[0037] The control unit 120 can be configured to generate a plurality of correction profiles that indicate the correspondence between voltage and capacity change amount based on a plurality of battery profiles.

[0038] Here, the correction profile may be a profile indicating the correspondence relationship between the voltage and the capacity change of the battery. That is, the battery profile is a profile relating to the voltage and the capacity, while the correction profile may be a profile relating to the voltage and the capacity change. That is, the control unit 120 may calculate the capacity change from the battery profile and generate a correction profile indicating the correspondence relationship between the calculated capacity change and the voltage.

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

[0040] Here, the reference profile may be set to a battery profile related to a battery in a beginning of life (BOL) state. For example, the reference profile may be a battery profile theoretically set to reflect the BOL state of the battery. As another example, the reference profile may be a battery profile corresponding to the first cycle among a plurality of battery profiles stored in the storage unit 110. In the following description, it is assumed that the battery profile corresponding to the first cycle in the embodiment of FIG. 2 is set to the reference profile.

[0041] Specifically, the control unit 120 calculates "Q ij -Q 1j The capacitance change can be calculated by calculating the equation: where i is the cycle index and j is the voltage index. Q ij is the capacity corresponding to voltage j of the battery profile corresponding to cycle i, and Q 1j is the capacity corresponding to the voltage j of the reference profile. That is, the control unit 120 may calculate the difference between the capacity of the battery profile and the capacity of the reference profile for each voltage to calculate the amount of capacity change.

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

[0043] 2, it is assumed that the battery profile corresponding to the first cycle is the reference profile. The control unit 120 may calculate the difference in capacity for each voltage between the reference profile and each of the battery profiles corresponding to the first to sixth cycles to generate a plurality of correction profiles.

[0044] 3 is a diagram illustrating a cycle-by-cycle correction profile of a first battery according to an embodiment of the present invention. For example, the battery profile may be represented by an XY graph in which the X axis represents voltage and the Y axis represents capacity change.

[0045] The embodiment of Fig. 3 may be a plurality of correction profiles for a plurality of battery profiles according to the embodiment of Fig. 2. For example, the embodiment may be a plurality of correction profiles generated for a plurality of battery profiles using a reference profile (a battery profile corresponding to the first cycle) as a reference. Here, since the reference profile is set to the battery profile corresponding to the first cycle, in the embodiment of Fig. 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 normalization values ​​for the generated correction profiles.

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

[0048] 4 is a diagram illustrating the standard score for each cycle of a first battery according to an embodiment of the present invention. For ease of explanation, the embodiment of FIG. 4 illustrates normalized values ​​(standard scores) calculated in a preset voltage range RV of 3.9 V to 4.1 V.

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

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

[0051] It should be noted that the standard score corresponding to the first cycle is excluded in the embodiment of Figure 4. That is, the embodiment of Figure 4 shows the standard scores corresponding to the second to sixth cycles. Referring to Figure 4, the standard score corresponding to each cycle can be calculated from each voltage.

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

[0053] The control unit 120 may calculate the kurtosis for each cycle based on the multiple standard scores calculated for each cycle. For example, the control unit 120 may calculate the kurtosis by calculating the average of the fourth power of the multiple standard scores calculated for each cycle. If the standard score is denoted as Z, the kurtosis is expressed as E[Z 4 ] can be expressed as:

[0054] 5 is a diagram illustrating the kurtosis for each cycle of a first battery according to an embodiment of the present invention, which shows the kurtosis for all cycles performed on the first battery.

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

[0056] Specifically, the reference value R 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 can be a cell induced to deposit lithium metal. The reference value R can be determined based on the kurtosis of such a test cell.

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

[0058] 5, the kurtosis for the first battery may be equal to or greater than the reference value R K after about 200 cycles, and therefore the battery diagnostic device 100 may diagnose the state of the first battery as a lithium deposition state.

[0059] The battery diagnostic device 100 according to an embodiment of the present invention may diagnose the battery state based on normalized values ​​for a battery profile corresponding to multiple cycles. That is, the battery diagnostic device 100 may reflect a long-term trend of the battery and more accurately diagnose the battery state.

[0060] Meanwhile, the control unit 120 provided in the battery diagnostic device 100 may optionally include a processor, an application specific integrated circuit (ASIC), other chipsets, logic circuits, registers, a communication modem, a data processing device, etc., known in the art, to execute various control logics performed in the present invention. 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 executed by the control unit 120. The memory may be internal or external to the control unit 120 and may be connected to the control unit 120 by various well-known means.

[0061] The memory unit 110 may also store data and programs required for each component of the battery diagnostic device 100 to operate and function, or data generated during the operation and function. The memory unit 110 may be any known information storage means known to be capable of recording, erasing, updating, and reading data. For example, the information storage means may include random access memory (RAM), flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), registers, etc. The memory unit 110 may also store program code defining processes executable by the control unit 120.

[0062] FIG. 6 is a diagram schematically illustrating a battery profile for each cycle of a second battery according to an embodiment of the present invention.

[0063] As with the embodiment of Figure 2, in the embodiment of 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 storage unit 110 may store the battery profiles of the first to sixth cycles for the second battery.

[0065] FIG. 7 is a diagram schematically illustrating a correction profile for each cycle of a second battery according to an embodiment of the present invention.

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

[0067] 8 is a diagram illustrating the standard score for each cycle of a second battery according to an embodiment of the present invention. Note that, like the embodiment of FIG. 4, the standard score corresponding to the first cycle is omitted in the embodiment of FIG. 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] 9 is a schematic diagram illustrating the kurtosis by cycle of a second battery according to an embodiment of the present invention. Specifically, the embodiment of FIG. 9 illustrates the kurtosis for all cycles performed on the second battery.

[0070] The control unit 120 can compare the multiple kurtosis values ​​of the second battery with the reference value R. Since the kurtosis of the second battery is less than the reference value R 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 section RV from each of the multiple correction profiles. For example, the control unit 120 may be configured to calculate the kurtosis of the preset voltage section RV for each of the multiple correction profiles as the normalized value.

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

[0073] 3 and 7, the first battery in a lithium deposition state exhibits an increased capacity change in a predetermined voltage section RV, whereas the second battery in a normal state exhibits no increased capacity change in the predetermined voltage section RV. That is, if lithium metal is deposited on the surface of the negative electrode, an abnormal phenomenon occurs in which the capacity change increases in the predetermined voltage section RV. Therefore, the control unit 120 may calculate a normalized value for the predetermined voltage section RV from the battery profile, taking into account the characteristics of the battery in a lithium deposition state.

[0074] Specifically, the control unit 120 may calculate a standard score for each voltage in a predetermined voltage section RV of a plurality of correction profiles, and calculate the kurtosis for each cycle according to the calculated standard score.

[0075] The battery diagnostic device 100 has the advantage of efficiently utilizing system resources and quickly diagnosing the battery state by diagnosing the battery based on a voltage range that can distinguish between a lithium deposition state and a normal state.

[0076] A specific embodiment in which the control unit 120 calculates the kurtosis from each of a plurality of correction profiles will be described below.

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

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

[0079] For example, assume that the target voltage is Vj and the capacitance change rate corresponding to the target voltage is ΔQij, where i is a cycle index and j is a voltage index. In the embodiment of Fig. 3, the control unit 120 can 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 scores for the selected plurality of capacitance changes for each of the plurality of correction profiles.

[0081] For example, the control unit 120 may calculate standard scores for the selected ΔQ1j, ΔQ2j, ΔQ3j, ΔQ4j, ΔQ5j, and ΔQ6j. That is, the control unit 120 may calculate standard scores for a plurality of 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] The control unit 120 may then be configured to calculate the kurtosis of each of the plurality of correction profiles based on the standard score calculated for each of the plurality of correction profiles.

[0083] For example, after the calculation of the standard scores in the preset voltage ranges RV of the plurality of correction profiles is completed, the standard scores for each voltage may be set for each cycle. The control unit 120 may calculate the kurtosis of each cycle based on the plurality of standard scores corresponding to each cycle.

[0084] In the embodiment of FIG. 4, the control unit 120 may calculate the kurtosis of the fourth cycle based on a plurality of standard scores corresponding to the fourth cycle.

[0085] That is, each standard score is calculated based on the amount of capacitance change of a plurality of correction profiles, but the kurtosis can be calculated based on the standard score of the corresponding cycle.

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

[0087] The standard score may be calculated based on the amount of capacity change of multiple correction profiles. That is, if multiple correction profiles are added, the amount of capacity change that serves as the basis for calculating the standard score may also be added. In this case, the standard score for each cycle for the voltage is calculated based on all the amount of capacity change, so the control unit 120 may re-diagnose the battery state to take into account the change trend of the battery state.

[0088] That is, the battery diagnostic device 100 re-diagnoses the battery state every time a new battery profile is stored, thereby reflecting the long-term trend of the battery and enabling a more accurate diagnosis of the battery state.

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

[0090] The battery diagnostic device 100 according to the present invention may be provided in 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. Furthermore, the battery pack may further include electrical components (relays, fuses, etc.), a case, etc.

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

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

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

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

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

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

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

[0098] FIG. 12 is a 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. In the following, for ease of explanation, the overlapping content with the content explained above will be omitted or explained briefly.

[0100] The battery diagnostic method may include a storing step (S100), a correction profile generating step (S200), a normalization value calculating step (S300), and a diagnosis step (S400).

[0101] The storage step (S100) is a step of storing a plurality of battery profiles corresponding to a plurality of cycles and indicating the correspondence between the voltage and capacity of the battery, and can be performed by the storage unit 110.

[0102] Specifically, the battery profile acquired in each of the multiple cycles may be stored in the storage unit 110. For example, if N cycles have been performed, N battery profiles may be stored in the storage unit 110.

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

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

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

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

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

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

[0109] 4, the control unit 120 may calculate a standard score for each voltage in each cycle based on the multiple correction profiles. The control unit 120 may then calculate a kurtosis for each cycle. Here, the kurtosis may be a normalized value for each cycle.

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

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

[0112] The above-described embodiments of the present invention can be realized not only by the apparatus and method but also by a program that realizes the functions corresponding to the configurations of the embodiments of the present invention or a recording medium on which the program is recorded. Such realization can be easily achieved by a person skilled in the technical field to which the present invention pertains from the description of the above-described embodiments.

[0113] Although the present invention has been described above using limited embodiments and drawings, it goes without saying that the present invention is not limited to these, and that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the appended claims.

[0114] Furthermore, the present invention described above is susceptible to various substitutions, modifications, and alterations by a person having ordinary knowledge in the technical field to which the present invention pertains, within the scope of the technical concept of the present invention. Therefore, the present invention is not limited to the above-described embodiments and the accompanying drawings, but may be configured by selectively combining all or part of each embodiment for various modifications. [Explanation of symbols]

[0115] 1 battery pack 10 Battery 20 Measuring part 100 Battery diagnostic device 110 Storage section 120 control section 1100 Automobiles 1110 Battery Pack

Claims

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

2. The control unit If at least one of the plurality of normalized values ​​is equal to or greater than the 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 battery as being in a normal state if the normalized values ​​are less than the reference value.

3. The control unit The battery diagnostic device according to claim 1 , wherein the device is configured to calculate a normalized value of the amount of change in capacity 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 , wherein the device is configured to calculate, as the normalized value, a kurtosis of the predetermined voltage interval for the plurality of correction profiles.

5. The control unit 5. The battery diagnostic device according to claim 4, wherein the battery diagnostic device is configured to calculate a standard score of the amount of capacity change for each voltage in the predetermined voltage range from the plurality of correction profiles, and to calculate the kurtosis of each of the plurality of correction profiles based on the standard score calculated for each of the plurality of correction profiles.

6. The control unit 6. The battery diagnostic device according to claim 5, further comprising: a capacitance change amount corresponding to each of the voltages selected from the plurality of correction profiles; and a standard score for each of the selected capacitance change amounts calculated for each of the plurality of correction profiles.

7. The control unit 2. The battery diagnostic device according to claim 1, wherein the battery diagnostic device is configured to calculate a capacity change amount for each voltage of the plurality of battery profiles by calculating a capacity difference for each voltage between a preset reference profile and each of the plurality of battery profiles, and to generate the plurality of correction profiles according to the calculated capacity change amount and the voltage.

8. The control unit 2. The battery diagnostic device according to claim 1, wherein, if a new battery profile is further stored in the storage unit, the battery state is diagnosed based on all of the battery profiles stored in the storage unit.

9. A battery pack comprising the battery diagnostic device according to any one of claims 1 to 8.

10. a storing step of storing 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; a correction profile generating step of generating a plurality of correction profiles indicating a correspondence relationship between voltage and capacity change amount based on the plurality of battery profiles; a normalization value calculation step of calculating normalization values ​​for the generated plurality of correction profiles; a diagnosis step of diagnosing the state of the battery based on the calculated normalized values ​​and a preset reference value; A battery diagnostic method comprising:

Images