Apparatus and method for acquiring battery degradation indicator information, battery pack, and electric vehicle

Abstract

An apparatus and a method for acquiring degradation indicator information about a battery are provided. The apparatus comprises: a measurement unit for generating a voltage sample value and a current sample value of a battery cell; and a control unit for setting first to nth ranges of interest and first to nth sampling rates for the current charging / discharging process on the basis of previous degradation indicator information associated with the previous charging / discharging process. The control unit acquires the voltage sample value and the current sample value at one or more sampling rates selected from among a reference sampling rate and the first to nth sampling rates during the current charging / discharging process, and detects the peak of one or more of the first to nth ranges of interest from the current differential voltage profile of the battery cell generated on the basis of the voltage sample value and the current sample value acquired in the progress period of the current charging / discharging process, so as to determine the current degradation indicator information.

Description

Device and method for obtaining battery degradation indicator information, battery pack, and electric vehicle

[0001] The present invention relates to a device and method for obtaining degradation indicator information of a battery.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0107209, filed on August 16, 2023, and Korean Patent Application No. 10-2024-0095689, filed on July 19, 2024, the entire contents of which are disclosed in the specification and drawings of the above applications are incorporated herein by reference.

[0003]

[0004] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0005] Currently commercialized batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based batteries.

[0006] In general, since these batteries deteriorate as they are used, it is necessary to accurately determine the state of the battery in order to accurately estimate the state of charge (SOC) and state of health (SOH) of the deteriorated battery, or to control the battery to increase its lifespan.

[0007] Conventionally, a method has been used to detect at least two peaks from a differential voltage profile generated based on actual measured values ​​of the voltage and current of a battery, and then estimate the degree of battery deterioration by comparing the peak characteristic information of the two peaks.

[0008] However, as the battery deteriorates, the shape of the differential voltage profile gradually deforms, so that the detection accuracy for each peak of the differential voltage profile may deteriorate at a low sampling rate for voltage and current measurements.

[0009] To improve this, the applied sampling rate must be increased, but this not only requires a large amount of memory for recording battery data, but also increases the power consumed for sampling and places an excessive computational load on the processing of battery data.

[0010]

[0011] The present invention has been made to solve the above problems, and the purpose of the present invention is to provide a device and method capable of acquiring information on degradation indicators that sufficiently reflect the actual degradation state of a battery cell while reducing the computational load applied to a battery system by variably adjusting a sampling rate used to measure voltage and current that serve as the basis for generating a differential voltage profile of a battery cell, and a battery pack including the device and an electric vehicle including the battery pack.

[0012] Other objects and advantages of the present invention can be understood through the following description and will be more clearly understood through 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.

[0013]

[0014] According to one aspect of the present invention for achieving the above object, a device for obtaining battery degradation indicator information includes: a measuring unit configured to generate a voltage sample value and a current sample value of a battery cell; and a control unit configured to set first to n-th interest ranges and first to n-th sampling rates for a current charging / discharging process based on previous degradation indicator information associated with a previous charging / discharging process. n is a natural number greater than or equal to 2. The control unit is configured to obtain the voltage sample value and the current sample value of the battery cell at at least one sampling rate selected from a reference sampling rate and the first to n-th sampling rates during the progress of the current charging / discharging process. The control unit is configured to perform peak detection for at least one of the first to n-th interest ranges from a current differential voltage profile of the battery cell generated based on the voltage sample value and the current sample value acquired during the progress period of the current charging / discharging process, thereby determining current degradation indicator information.

[0015] The control unit may be configured to select an i-th sampling rate among the first to n-th sampling rates when the capacity value of the battery cell falls within an i-th interest range among the first to n-th interest ranges during the progress of the current charging and discharging process. i is a natural number less than or equal to n. The control unit may be configured to select the reference sampling rate when the capacity value of the battery cell falls outside all of the first to n-th interest ranges during the progress of the current charging and discharging process.

[0016] Each of the first to nth sampling rates may be greater than the reference sampling rate.

[0017] At least two of the first to nth sampling rates may be equal to each other.

[0018] The above-described previous degradation indicator information may include peak feature data of at least one of the first to nth peaks of interest detected from the previous differential voltage profile. The peak feature data may indicate at least one of a capacity value, a differential voltage value, or kurtosis.

[0019] The above control unit may be configured to set the size of the i-th interest range for the current charging / discharging process by applying a predetermined negative correspondence to the kurtosis of the i-th interest peak included in the previous degradation indicator information. i is a natural number less than or equal to n.

[0020] The above control unit may be configured to set an upper limit of an i-th interest range for the current charging / discharging process so as to be equal to the capacity value of an i-th interest peak among the first to n-th interest peaks included in the previous degradation indicator information. i is a natural number less than or equal to n.

[0021] The above control unit may be configured to set the i-th sampling rate for the current charging / discharging process by applying a predetermined positive correspondence to the kurtosis of the i-th peak of interest included in the previous degradation indicator information. i is a natural number less than or equal to n.

[0022] A battery pack according to another aspect of the present invention includes a device for obtaining battery degradation indicator information.

[0023] An electric vehicle according to another aspect of the present invention includes the battery pack.

[0024] According to another aspect of the present invention, a method for obtaining battery degradation indicator information includes the steps of: setting first to n-th interest ranges and first to n-th sampling rates for a current charge / discharge process based on previous degradation indicator information associated with a previous charge / discharge process; obtaining a voltage sample value and a current sample value of the battery cell at at least one sampling rate selected from a predetermined reference sampling rate and the first to n-th sampling rates during the progress of the current charge / discharge process; and performing peak detection for at least one of the first to n-th interest ranges from a current differential voltage profile of the battery cell generated based on the voltage sample value and the current sample value obtained during the progress of the current charge / discharge process, thereby determining current degradation indicator information. n is a natural number greater than or equal to 2.

[0025] The step of obtaining the voltage sample value and the current sample value of the battery cell may include the following steps that are repeatedly performed during the progress of the current charging / discharging process: when the capacity value of the battery cell falls within an i-th interest range among the first to n-th interest ranges, obtaining the voltage sample value and the current sample value of the battery cell at an i-th sampling rate among the first to n-th sampling rates; and when the capacity value of the battery cell falls outside all of the first to n-th interest ranges, obtaining the voltage sample value and the current sample value of the battery cell at the reference sampling rate. i is a natural number less than or equal to n.

[0026] The above-mentioned previous degradation indicator information may include peak characteristic data of at least one of the first to nth peaks of interest detected from the previous differential voltage profile. The peak characteristic data may indicate at least one of a capacity value, a differential voltage value, or kurtosis.

[0027] The upper limit of the i-th interest range for the charging / discharging process of the above-mentioned current may be set equal to the capacity value of the i-th interest peak included in the previous degradation indicator information. i may be a natural number less than or equal to n.

[0028] The i-th sampling rate for the charging / discharging process of the above-described current meeting can be set to have a predetermined positive correspondence to the kurtosis of the i-th peak of interest included in the above-described previous degradation index information. i is a natural number less than or equal to n.

[0029]

[0030] According to at least one of the embodiments of the present invention, when measuring the voltage and current of a battery cell that serve as the basis for generating a differential voltage profile, by dynamically changing the sampling rate, computational load can be reduced, and detection accuracy for a peak on the differential voltage profile, which is an indicator of degradation of the battery cell, can be improved.

[0031] In addition, according to at least one of the embodiments of the present invention, by distinguishing a range of interest, which is a range of capacity in which each peak is expected to appear among the entire range of capacity, and the remaining range of capacity, and setting the sampling rate applied to the range of interest to be greater than the sampling rate applied to the remaining range of capacity, it is possible to suppress an excessive increase in the amount of computation and data storage space required to obtain a differential voltage profile.

[0032] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0033]

[0034] 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 further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0035] Figure 1 is a drawing exemplarily showing the configuration of an electric vehicle according to the present invention.

[0036] Figure 2 is a graph used as a reference for comparing two voltage profiles generated by two adjacent charge / discharge processes.

[0037] Figure 3 is a graph used as a reference for comparing two differential voltage profiles corresponding one-to-one to the two voltage profiles illustrated in Figure 2.

[0038] Figure 4 is a drawing for reference in explaining a procedure for setting a range of interest for a specific round of charging / discharging process.

[0039] Figures 5a to 5c are drawings for reference in explaining changes in peak detection power according to changes in the applied sampling rate.

[0040] FIG. 6 is a flowchart for reference in exemplifying a method for obtaining battery degradation indicator information according to another embodiment of the present invention.

[0041] FIG. 7 is a flowchart referenced to exemplarily explain the subroutines of step S610 of FIG. 6.

[0042] FIG. 8 is a flowchart referenced to exemplarily explain the subroutines of step S611 of FIG. 6.

[0043]

[0044] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that conforms to the technical spirit of the present invention.

[0045] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0046] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0047] Throughout the specification, when a part is said to "include" a component, this does not exclude other components, unless otherwise stated, but rather implies the inclusion of other components. Furthermore, terms such as "control unit" described in the specification mean a unit that processes at least one function or operation, and may be implemented using hardware, software, or a combination of hardware and software.

[0048] Additionally, throughout the specification, when we say that a part is "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] Figure 1 is a drawing exemplarily showing the configuration of an electric vehicle according to the present invention.

[0050] Referring to FIG. 1, an electric vehicle (1) includes a vehicle controller (2), a battery pack (10), a switching device (20), an inverter (30), and an electric motor (40).

[0051] The charge / discharge terminals (P+, P-) of the battery pack (10) can be electrically connected to an inverter (30) and / or a charger (3) via a charging cable or the like. The charger (3) may be included in the electric vehicle (1) or provided at a charging station.

[0052] The vehicle controller (2) (e.g., ECU: Electronic Control Unit) is configured to transmit a key-on signal to the battery management system (100) in response to a start button (not shown) provided in the electric vehicle (1) being turned to the ON position by a user. The vehicle controller (2) is configured to transmit a key-off signal to the battery management system (100) in response to a start button being turned to the OFF position by a user. The charger (3) can communicate with the vehicle controller (2) and supply charging power in a constant current charging mode, a constant voltage charging mode, and / or a constant power charging mode to the battery (11) through the charge / discharge terminals (P+, P-) of the battery pack (10).

[0053] The battery pack (10) includes a battery (11) and a battery management system (100). The battery management system (100) corresponds to the 'battery degradation indicator information acquisition device' described in the claims of this specification.

[0054] The battery (11) includes a cell group (12) and a case (13). The case (13) defines the overall appearance of the battery (11) and provides an internal space in which the cell group (12) can be placed. The case (13) is fixed to a battery room provided in an electric vehicle (1) using bolts or the like.

[0055] The cell group (12) is arranged (stored) in the internal space provided from the case (13) and includes at least one battery cell (BC). The type of the battery cell (BC) is not particularly limited, as long as it is capable of repeated charging and discharging, such as a lithium ion cell.

[0056] When the cell group (12) includes multiple battery cells, these multiple battery cells may be connected in series, parallel, or in a mixed series-parallel manner.

[0057] The switching device (20) is electrically connected in series to the battery (11) via a power path connecting the battery (11) and the inverter (30). In Fig. 1, the switching device (20) is illustrated as being connected between the positive terminal of the battery (11) and the charge / discharge terminal (P+). The switching device (20) is turned on and off in response to a switching signal from the battery management system (100). The switching device (20) may be a mechanical contactor that is turned on and off by the magnetic force of a coil, or a semiconductor switch such as a MOSFET (Metal Oxide Semiconductor Field Effect transistor).

[0058] An inverter (30) is provided to convert direct current from a group of cells (12) into alternating current in response to a command from a battery management system (100) or a vehicle controller (2).

[0059] The electric motor (40) is driven using AC power from the inverter (30). For example, a three-phase AC motor (40) can be used as the electric motor (40).

[0060] The battery management system (100) includes a measurement unit, a control unit (130), and a storage unit (140). The battery management system (100) may further include an external temperature sensor (117). The battery management system (100) may further include a communication circuit (150).

[0061] The measuring unit includes a voltage sensor (111) and a current sensor (113). The measuring unit may further include a temperature sensor (115). For convenience of explanation, the following description will assume that the measuring unit includes all of the voltage sensor (111), the current sensor (113), and the temperature sensor (115).

[0062] The voltage sensor (111) is connected in parallel to the battery (11), detects the battery voltage, which is the voltage across both terminals of the battery (11), and is configured to generate a voltage signal representing the detected battery voltage.

[0063] Of course, the voltage sensor (111) is connected to the positive terminal and negative terminal of each battery cell (BC) included in the battery (11), detects the cell voltage, which is the voltage across both ends of each battery cell (BC), and may output an additional voltage signal representing the cell voltage to the control unit (130).

[0064] The current sensor (113) is connected in series to the battery (11) via a current path between the battery (11) and the inverter (30). The current sensor (113) is configured to detect battery current, which is a current flowing through the battery (11), and generate a current signal representing the detected battery current. The current sensor (113) may be implemented using one or a combination of two or more of known current detection elements, such as a shunt resistor, a Hall effect element, etc.

[0065] The temperature sensor (115) is configured to detect the battery temperature and generate a temperature signal representing the detected battery temperature. The temperature sensor (115) may be placed within the case (13) so as to detect a temperature close to the actual temperature of the battery (11). For example, the temperature sensor (115) may be attached to the surface of at least one battery cell (BC) included in the cell group (12) and may detect the surface temperature of the battery cell (BC) as the battery temperature. For reference, the term "temperature detection value" simply described herein may refer to a battery temperature detection value.

[0066] The outside temperature sensor (117) is configured to detect the outside temperature (ambient temperature), which is the temperature at a predetermined location away from the battery (11), and generate a temperature signal representing the detected outside temperature. The outside temperature sensor (117) can be placed at a predetermined location outside the case (13) where heat exchange between the battery (11) and the outside air takes place.

[0067] Each of the temperature sensor (115) and the outside temperature sensor (117) can be implemented as a combination of one or two or more of known temperature detection elements such as a thermocouple, a thermistor, a bimetal, etc.

[0068] The communication circuit (150) is configured to support wired or wireless communication between the control unit (130) and the vehicle controller (2). The wired communication may be, for example, CAN (controller area network) communication, and the wireless communication may be, for example, Zigbee or Bluetooth communication. Of course, as long as it supports wired or wireless communication between the control unit (130) and the vehicle controller (2), the type of communication protocol is not particularly limited. The communication circuit (150) may include an output device (e.g., a display, a speaker) that provides information received from the control unit (130) and / or the vehicle controller (2) in a form recognizable to a user.

[0069] The control unit (130) is operably coupled to at least one of the switching device (20), the voltage sensor (111), the current sensor (113), the temperature sensor (115), the outside temperature sensor (117), and the communication circuit (150). The fact that the two components are operably coupled means that the two components are directly or indirectly connected so as to be capable of transmitting and receiving signals in one direction or both directions.

[0070] The control unit (130) can collect a voltage signal from a voltage sensor (111), a current signal from a current sensor (113), a temperature signal from a temperature sensor (115) (which may be referred to as a 'battery temperature signal'), and / or a temperature signal from an outside temperature sensor (117) (which may be referred to as a 'outside temperature signal'). The control unit (130) can convert and record each analog signal collected from the sensors (111, 113, 115, 117) into a digital value using an ADC (Analog to Digital Converter) provided therein.

[0071] The control unit (130) may be referred to as a 'control circuit' or a 'battery controller', and may be implemented in hardware using at least one of ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), microprocessors, and other electrical units for performing functions.

[0072] The storage unit (140) may include at least one type of storage medium, for example, a flash memory type, a hard disk type, an SSD (Solid State Disk type), an SDD (Silicon Disk Drive type), a multimedia card micro type, a RAM (random access memory), a SRAM (static random access memory), a ROM (read-only memory), an EEPROM (electrically erasable programmable read-only memory), and a PROM (programmable read-only memory). The storage unit (140) may store data and a program required for an operation by the control unit (130). The storage unit (140) may store data representing a result of an operation by the control unit (130). In FIG. 1, the storage unit (140) is illustrated as being physically independent from the control unit (130), but may also be built into the control unit (130).

[0073] The control unit (130) can turn on the switching device (20) in response to a key-on signal. The control unit (130) can turn off the switching device (20) in response to a key-off signal. The key-off signal is a signal that induces a transition from a cycle state to an idle state. Alternatively, the on / off control of the switching device (20) may be performed by the vehicle controller (2) instead of the control unit (130).

[0074] When the inverter (30) or the charger (3) operates while the switching device (20) is turned on, the battery (11) enters a cycle state. Conversely, when the switching device (20) is turned off or the operation of the inverter (30) and the charger (3) is stopped, the battery (11) enters a rest state.

[0075] The cycle state refers to a state in which the battery (11) is being charged and discharged, and the rest state refers to a state in which the charging and discharging of the battery (11) has stopped. The fact that the battery (11) is in a cycle state or rest state means that each battery cell (BC) included in the battery (11) is also in a cycle state or rest state.

[0076] For reference, the charge / discharge process described herein refers to a procedure according to a protocol for charging and / or discharging a battery cell (BC) over a predetermined voltage range. The charge / discharge process includes at least one of a charge procedure and a discharge procedure for the battery cell (BC), and may further include a rest procedure. For example, the charge / discharge process may be a procedure for charging the battery cell (BC) with a constant current until the voltage of the battery cell (BC) reaches a lower voltage limit to an upper voltage limit within a predetermined voltage range. For another example, the charge / discharge process may be a procedure for discharging the battery cell (BC) with a constant current until the voltage of the battery cell (BC) reaches a lower voltage limit to a lower voltage limit within a predetermined voltage range. Of course, the charge / discharge process may include only one of the constant current discharge function and the constant current charge function.

[0077] While the charging / discharging process is in progress, the control unit (130) can periodically or aperiodically collect voltage signals and current signals representing the voltage and current of the battery cell (BC). The control unit (130) determines voltage sample values ​​and current sample values ​​based on the collected voltage signals and current signals, and integrates the current sample values ​​over time to determine the capacity value of the battery cell (BC) at each sampling timing during the progress of the charging / discharging process. Accordingly, a voltage time series and a capacity time series reflecting temporal changes in the voltage sample values ​​and the capacity values, respectively, can be updated in accordance with the sampling timing of the voltage signals and the current signals.

[0078] The control unit (130) can generate a voltage profile indicating a correspondence between the voltage and capacity of the battery cell (BC) based on a voltage time series and a capacity time series from a start point of the charge / discharge process to a specific point in time during the charge / discharge process or to the completion point of the charge / discharge process. The control unit (130) can generate a differential voltage profile indicating a correspondence between the capacity of the battery cell (BC) and a differential voltage from the voltage profile of the battery cell (BC). The voltage time series, current time series, and capacity time series may be referred to as voltage history, current history, and capacity history, respectively.

[0079] FIG. 2 is a graph used as a reference for comparing two voltage profiles generated by two adjacent charge / discharge processes. In FIG. 2, the X-axis (horizontal axis) represents charge / discharge capacity, and the Y-axis (vertical axis) represents voltage. In the present invention, it is assumed that the symbol m used as an ordinal number is a natural number greater than or equal to 1 indicating the number of times of the previous charge / discharge process. For example, if a total of 99 charge / discharge processes have been completed from the time the battery cell (BC) was shipped to the present, m is 99. The m-th charge / discharge process may be referred to as the 'previous charge / discharge process' or the 'previous charge / discharge process', and the (m+1)-th charge / discharge process may be referred to as the 'current charge / discharge process' or the 'current charge / discharge process'. For reference, the voltage profile may also be referred to as a voltage curve, a QV profile, or a QV curve.

[0080] The m voltage profile (201) represents the correspondence between the capacity and voltage of the battery cell (BC) based on the capacity history and voltage history of the battery cell (BC) during the progress of the m charge / discharge process.

[0081] Similarly, the (m+1) voltage profile (202) represents the correspondence between the capacity and voltage of the battery cell (BC) based on the capacity history and voltage history of the battery cell (BC) during the progress of the (m+1) charge / discharge process.

[0082] For reference, a capacity history can represent a time-series change in the charge or discharge capacity of a battery cell (BC) from the start of a charge or discharge event to its end. Similarly, a voltage history can represent a time-series change in the voltage of a battery cell (BC) from the start of a charge or discharge event to its end.

[0083] Referring to Fig. 2, when comparing the m-th voltage profile (201) and the (m+1)-th voltage profile (202), in the same capacity range, the voltage change of the (m+1)-th voltage profile (202) is greater than the voltage change of the m-th voltage profile (201). This difference may be due to an increased degree of degradation of the battery cell (BC) due to capacity loss of the positive and / or negative electrodes, lithium deposition, etc. that may occur as the charge / discharge process for the battery cell (BC) progresses.

[0084] Figure 3 is a graph used as a reference for comparing two differential voltage profiles corresponding one-to-one to the two voltage profiles illustrated in Figure 2.

[0085] In Fig. 3, the X-axis (horizontal axis) represents the same charge / discharge capacity as in Fig. 2, and the Y-axis (vertical axis) represents the differential voltage. The differential voltage dV / dQ represents the ratio of the change in voltage dV to the change in charge or discharge capacity dQ.

[0086] Referring to FIGS. 2 and 3, the control unit (130) can obtain the m-th differential voltage profile (301) by differentiating the voltage history of the battery cell (BC), acquired during the progress period of the m-th charge / discharge process, with respect to the corresponding capacity history. That is, the m-th voltage profile (201) can be viewed as a function of either the capacity or the voltage, and the m-th differential voltage profile (301) can be a result of first differentiating the voltage of the m-th voltage profile (201) with respect to the capacity. The m-th differential voltage profile (301) can also be referred to as a ‘previous differential voltage profile’ or a ‘previous differential voltage profile’.

[0087] Likewise, the control unit (130) can obtain the (m+1) differential voltage profile (302) by differentiating the voltage history of the battery cell (BC) acquired during the progress period of the (m+1)th charge / discharge process with respect to the corresponding capacity history. The (m+1) differential voltage profile (302) can be a result of first differentiating the voltage of the (m+1)th voltage profile (202) with respect to the capacity.

[0088] Referring to FIG. 3, the (m+1)-th differential voltage profile (302) is in the form of the m-th differential voltage profile (301) contracted to the left along the X-axis, and even if the m-th differential voltage profile (301) and the (m+1)-th differential voltage profile (302) have the same voltage range, the capacity history of the m-th differential voltage profile (301) and the capacity history of the (m+1)-th differential voltage profile (302) do not have the same capacity range. The (m+1)-th differential voltage profile (302) may also be referred to as the 'current differential voltage profile' or the 'current differential voltage profile'.

[0089] For reference, the (m+1)-th charge / discharge process performed to obtain the (m+1)-th differential voltage profile (302) may be performed after the battery cell (BC) has been additionally charged / discharged to some extent from the end of the m-th charge / discharge process performed to obtain the m-th differential voltage profile (301). Accordingly, the degradation index of the battery cell (BC) reflected in the (m+1)-th differential voltage profile (302) may be more severe than the degradation index of the battery cell (BC) reflected in the m-th differential voltage profile (301).

[0090] Compared to the two voltage profiles (201, 202) of FIG. 2, the two differential voltage profiles (301, 302) illustrated in FIG. 3 have multiple peaks. The multiple peaks can be distinguished from each other by the order and / or position (capacity value) of each peak. For example, the multiple peaks can be ranked (in descending or ascending order) by their respective capacities. In this regard, the total number of peaks located in the differential voltage profile for a specific voltage range and / or a specific capacity range can be determined by the types of the positive active material and the negative active material of the battery cell (BC), etc.

[0091] The peak of any profile may be a general term for either or both of the maximum and minimum points appearing on the profile.

[0092] In the present invention, the peak characteristic information may include at least one peak parameter representing the characteristic of at least one peak appearing in the differential voltage profile.

[0093] For example, peak characteristic information of an arbitrary peak includes at least one peak parameter. Here, the capacity and differential voltage as location information (i.e., two-dimensional coordinates) of the peak, and kurtosis, etc. may be included in the peak characteristic information as individual peak parameters.

[0094] In the present invention, the degradation indicator information of a battery cell (BC) may include peak characteristic information of each of the first to nth peaks of interest located on a differential voltage profile. n is a natural number greater than or equal to 2.

[0095] In the present invention, the "peak of interest" may refer to two or more predetermined peaks among a plurality of peaks located on a differential voltage profile. Each of the plurality of peaks, either alone or in comparison with other peaks, may indicate a specific type of deterioration condition. Accordingly, each peak associated with the deterioration condition being diagnosed may be pre-programmed to be designated as a peak of interest.

[0096] In Fig. 3, symbols P11 to P17 represent multiple peaks located on the m-th differential voltage profile (301). In addition, symbols P21 to P27 represent multiple peaks located on the (m+1)-th differential voltage profile (302). When k is a natural number less than or equal to the total number of peaks, the peak (P2k) of the (m+1)-th differential voltage profile (302) is the peak (P1k) of the m-th differential voltage profile (301) shifted to the left. Therefore, it can be said that the two peaks (P1k, P2k) are associated with the same type of deterioration state.

[0097] In addition, k corresponds to the order of appearance of each of the plurality of peaks of a specific differential voltage profile. For example, assuming that the m voltage profile (201) is acquired by constant current discharge, P11 is the peak with the lowest capacity that appears first in the m differential voltage profile (301), and P17 is the peak with the highest capacity that appears last (seventh) in the m differential voltage profile (301).

[0098] Among multiple peaks for each differential voltage profile, n peaks located in specific orders can be set as the first to nth peaks of interest for the corresponding differential voltage profile.

[0099] In Fig. 3, among the plurality of peaks (P11 to P17) appearing on the m-th differential voltage profile (301), four peaks (P12, P13, P14, P16) are sequentially set as the first to fourth peaks of interest (P[1] to P[4]). Therefore, in the following, it is assumed that n = 4.

[0100] Assuming that multiple peaks (P11 to P17) are ranked in descending order based on their capacity values, the peak of interest (P[1]) is the second peak (first local maximum), the peak of interest (P[2]) is the third peak (second local minimum), the peak of interest (P[3]) is the fourth peak (second local maximum), and the peak of interest (P[4]) is the sixth peak (third local maximum).

[0101] The peaks (P22, P23, P24, P26) on the (m+1)th differential voltage profile (302) correspond in order to the peaks of interest (P[1] to P[4]) on the mth differential voltage profile (301), and each of the peaks (P22, P23, P24, P26) is a peak of interest to be detected from the (m+1)th differential voltage profile (302).

[0102] Hereinafter, let us assume that i is a natural number less than or equal to n. The control unit (130) can set a specific capacity range including the capacity value of the ith peak of interest on the differential voltage profile (301) associated with the mth charge / discharge cycle as the ith range of interest associated with the (m+1)th charge / discharge cycle. That is, each time a charge / discharge process is performed, the first to nth ranges of interest individually associated with the first to nth peaks of interest can be set. The ith range of interest is for detecting the ith peak of interest.

[0103] Figure 4 is a drawing for reference in explaining a procedure for setting a range of interest for a specific round of charging / discharging process.

[0104] The first to fourth interest ranges (R#1 to R#4) illustrated in Fig. 4 are for the (m+1)th charge / discharge process.

[0105] In setting the range of interest for the (m+1)th charge / discharge process, the updated degradation indicator information of the battery cell (BC) based on the result of the previously completed mth charge / discharge process (which may be referred to as 'previous degradation indicator information', 'previous degradation indicator information', or 'mth degradation indicator information') may be utilized.

[0106] Referring to FIG. 4, prior to the start of the (m+1)th charge / discharge process, the control unit (130) can set the first to fourth interest ranges (R#1 to R#4) corresponding one-to-one to the first to fourth interest peaks (P[1] to P[4]) based on the peak characteristic information for the first to fourth interest peaks (P[1] to P[4]) acquired through the mth charge / discharge process.

[0107] The control unit (130) can determine the size and / or upper and lower limits of the interest range corresponding to each interest peak based on peak characteristic information for each of the first to nth interest peaks (P[1] to P[4]).

[0108] The control unit (130) can set the size of the ith interest range (R#i) by applying a predetermined negative correspondence to the kurtosis of the ith interest peak (P[i]) obtained in the mth charge / discharge process. That is, as the kurtosis of the ith interest peak (P[i]) increases, the size of the ith interest range (R#i) can decrease. Here, the kurtosis of any peak means the degree of sharpness of the peak. For example, the kurtosis of a specific peak can be determined as the same as the difference between the average differential voltage in a certain capacity range with the capacity value of the specific peak as the median value and the differential voltage of the specific peak.

[0109] For example, referring to FIG. 4, the size of the fourth interest range (R#4) may be the result of applying a predetermined negative correspondence to the kurtosis of the fourth interest peak (P[4]) obtained through the m-th charge / discharge process.

[0110] In setting the i-th interest range (R#i), the control unit (130) can set the upper limit of the i-th interest range (R#i) so that it is equal to the capacity value of the i-th interest peak (P[i]) included in the degradation indicator information of the battery cell (BC) acquired in the m-th charge / discharge process. For example, it can be confirmed from FIG. 4 that the upper limit of the second interest range (R#2) matches the capacity value of the second interest peak (P[2]) of the m-th differential voltage profile (301).

[0111] This is because, as the battery cell (BC) degrades, the differential voltage profile has the characteristic of shrinking to the left (low capacity side) along the X-axis.

[0112] When setting the i-th interest range (R#i) for the (m+1)-th charge / discharge process, the control unit (130) may set the capacity value of the i-th interest peak (P[i]) acquired in the m-th charge / discharge process as the upper limit of the i-th interest range (R#i), and may set the size of the i-th interest range (R#i) so that it has a predetermined negative correspondence with the kurtosis of the i-th interest peak (P[i]). Referring to FIG. 4, for example, the control unit (130) may set the upper limit of the second interest range (R#2) to be equal to the capacity value of the second interest peak (P[2]) acquired in the m-th charge / discharge process, and may set the size of the second interest range (R#2) to be equal to the result of applying a predetermined negative correspondence to the kurtosis of the second interest peak (P[2]).

[0113] In the (m+1)th charge / discharge process, the control unit (130) can determine the first to nth sampling rates to be individually utilized for the first to nth interest ranges (R#1 to R#4) based on the degradation index information of the battery cell (BC) obtained in the mth charge / discharge process.

[0114] The control unit (130) may select one of the reference sampling rate and the first to nth sampling rates at each sampling timing during the (m+1)th charge / discharge process, and sample the voltage and current of the battery cell (BC) at the selected sampling rate. The selected sampling rate may be referred to as a 'representative sampling rate'.

[0115] In the present invention, the sampling rate is a term referring to the number of samples (sampling count) per unit time (e.g., 1 second) taken from a continuous signal to create a discrete signal.

[0116] In the present invention, the reference sampling rate is a sampling rate separate from the first to nth sampling rates, and may be a default value of a sampling rate applicable to sampling timings to which the first to nth sampling rates are not applied. The reference sampling rate may be a predetermined constant.

[0117] Alternatively, the reference sampling rate may be a variable dependent on the State of Health (SOH) of the battery cell (BC). The SOH of the battery cell (BC) can be estimated using various known logics, and a detailed description thereof will be omitted.

[0118] The relationship data between the SOH and the reference sampling rate may be pre-recorded in the storage unit (140) in the form of a lookup table or a function (e.g., an SOH-sampling rate relationship curve). For example, the relationship data between the SOH and the reference sampling rate defines a negative correspondence in which the reference sampling rate increases as the SOH decreases, which reflects the characteristic of a battery cell (BC) in which the voltage change rate increases as the SOH increases.

[0119] In the present invention, a representative sampling rate can be used to collect voltage signals and current signals representing the voltage and current of a battery cell (BC) during the progress of the (m+1)th charge / discharge process.

[0120] At each sampling timing during the (m+1)th charge / discharge process, the control unit (130) can determine whether there is a range of interest to which the capacity value of the battery cell (BC) belongs among the first to nth ranges of interest (e.g., R#1 to R#4 in FIG. 4). If the capacity value of the battery cell (BC) belongs to the i-th range of interest (R#i), the control unit (130) can set the i-th sampling rate as the representative sampling rate. On the other hand, if the capacity value of the battery cell (BC) is outside the first to n-th ranges of interest (R#1 to R#4), the control unit (130) can set the reference sampling rate as the representative sampling rate.

[0121] The control unit (130) can set at least one of the first to nth sampling rates to be greater than the reference sampling rate. This is to precisely detect the ith peak of interest (P[i]) from a portion of the (m+1)th differential voltage profile (302) corresponding to the ith range of interest (R#i).

[0122] The control unit (130) can set at least two of the first to nth sampling rates to be the same. That is, the same size of sampling rate can be applied to at least two or more of the first to nth interest ranges (R#1 to R#4).

[0123] In the (m+1)th charge / discharge process, the control unit (130) can set the ith sampling rate by applying a predetermined positive correspondence to the kurtosis of the ith peak of interest (P[i]) included in the previous degradation index information. For example, the control unit (130) can determine the fourth sampling rate by multiplying the kurtosis of the fourth peak of interest (P[4]) by a predetermined positive coefficient.

[0124] Figures 5a to 5c are diagrams that are referenced to explain changes in peak detection power according to changes in representative sampling rates. In each of Figures 5a, 5b, and 5c, the X-axis represents time, and the Y-axis represents amplitude.

[0125] Specifically, Fig. 5a is a graph exemplifying a raw signal that is the target of sampling. The raw signal may, for example, represent an analog signal representing a temporal change in the voltage, current, or differential voltage of a battery cell (BC). In Fig. 5a, symbols P1a to P7a represent actual peaks of the raw signal.

[0126] Fig. 5b is a graph showing a plurality of discrete signal value(s) obtained by applying a low sampling rate (1 time / second) to the low signal illustrated in Fig. 5a. In Fig. 5b, the plurality of peaks indicated by symbols P1b to P7b are peaks appearing on a curve connecting the plurality of discrete signal value(s).

[0127] Comparing FIGS. 5A and 5B, it can be confirmed that it is difficult to accurately obtain peak characteristic information of the low signal illustrated in FIG. 5A based on the plurality of discrete signal value(s) illustrated in FIG. 5B. Specifically, not a single one of the plurality of peaks (P1b to P7b) in FIG. 5B matches the peaks (P1a to P7a) in FIG. 5A. That is, referring to FIGS. 5A and 5B, when a low sampling rate is applied, it is difficult to sufficiently precisely obtain peak characteristic information of the actual peak of the low signal. In addition, as in the case of FIG. 5B, the peak characteristic information of the curve (P1b to P7b in the case of FIG. 5B) obtained by applying a low sampling rate cannot properly reflect the degradation index information of the battery cell (BC).

[0128] On the other hand, Fig. 5c is a graph exemplarily showing multiple discrete signal value(s) obtained by applying a high sampling rate (2.5 times / second) to the low signal illustrated in Fig. 5a. In Fig. 5c, symbols P1c to P7c represent peaks appearing on a curve connecting multiple discrete signal value(s) obtained with a high sampling rate (2.5 times / second).

[0129] Comparing FIG. 5a and FIG. 5c, when the X-axis values ​​corresponding to the plurality of peaks (P1a to P7a) shown in FIG. 5a and the X-axis values ​​corresponding to the plurality of peaks (P1c to P7c) shown in FIG. 5c are matched one-to-one, the difference in the X-axis values ​​between the corresponding peaks becomes smaller as the applied sampling rate increases. That is, by applying a high number of sampling times per unit time, it is confirmed that signal values ​​in which the peak characteristic information of the continuous low signal shown in FIG. 5a is relatively more faithfully reflected are acquired in FIG. 5c.

[0130] Referring to the above FIGS. 5a, 5b and 5c, it can be seen that it is advantageous to apply a high sampling rate in order to obtain discrete signal value(s) including peak characteristic information of the low signal at each sampling timing.

[0131] FIG. 6 is a flowchart exemplarily illustrating a method for obtaining battery degradation indicator information according to another embodiment of the present invention. The method of FIG. 6 can be used to execute a new charge / discharge process after the first charge / discharge process for a battery cell (BC) is completed.

[0132] In performing the (m+1)th charge / discharge process, which is the current charge / discharge process, the control unit (130) can utilize the degradation index information of the battery cell (BC) updated in the mth charge / discharge process, which is the previous charge / discharge process that has been completed.

[0133] Before the current charge / discharge process is executed, the previous degradation indicator information stored in the storage unit (140) may include peak characteristic information of each of the first to nth peaks of interest (P[1] to P[4]) located on the differential voltage profile (301 in FIG. 4) obtained through the mth charge / discharge process.

[0134] Referring to FIGS. 1 to 4 along with FIG. 6, in step S610, the control unit (130) can set the first to nth interest ranges (R#1 to R#4 in FIG. 4) for the current charging / discharging process based on previous degradation indicator information associated with the previous charging / discharging process.

[0135] In step S611, the control unit (130) can set the first to nth sampling rates based on the previous degradation index information.

[0136] Steps S610 and S611 may be procedures executed to precisely detect the first to nth peaks of interest (P22, P23, P24, P26 in FIG. 4) from the differential voltage profile (302) to be acquired through the current charging / discharging process before the current charging / discharging process is initiated.

[0137] Specific details regarding the setting of the i-th interest range (R#i) and the i-th sampling rate will be described separately later with reference to FIGS. 7 and 8.

[0138] In step S612, the control unit (130) may initiate the current charging / discharging process. For example, the control unit (130) may request the charger (3) to initiate a charging procedure according to a predetermined charging protocol, or may request the inverter (30) or a separately provided discharging circuit (not shown) to initiate a discharging procedure according to a predetermined discharging protocol. For reference, the capacity value of the battery cell (BC) when step S612 is executed may be initialized to 0 [Ah].

[0139] In step S613, the control unit (130) can determine a representative sampling rate equal to the reference sampling rate.

[0140] In step S614, the control unit (130) can acquire voltage sample values ​​and current sample values ​​of the battery cell (BC) according to a representative sampling rate. Each time step S614 is executed, a current integration method or the like can be utilized to additionally acquire a capacity value of the battery cell (BC) based on the current sample value.

[0141] In step S615, the control unit (130) can determine whether the capacity value of the battery cell (BC) belongs to any one of the first to nth interest ranges (R#1 to R#4). That is, in step S615, it is determined whether there is a range of interest to which the capacity value of the battery cell (BC) belongs among the first to nth interest ranges (R#1 to R#4).

[0142] If the capacity value acquired in step S614 belongs to the i-th interest range (R#i) which is one of the first to n-th interest ranges (R#1 to R#4), the method of FIG. 6 may proceed to step S617. On the other hand, if the capacity value acquired in step S614 does not belong to any of the first to n-th interest ranges (R#1 to R#4), the method of FIG. 6 may proceed to step S616.

[0143] In step S617, the control unit (130) can determine a representative sampling rate equal to the i-th sampling rate. After step S617, the method according to FIG. 6 can proceed to step S614.

[0144] In step S616, the control unit (130) can determine whether the termination condition of the current charge / discharge process is satisfied. For example, if the current charge / discharge process is a constant current charging procedure, the termination condition of the charge / discharge process can be satisfied when the voltage sample value obtained in step S614 is equal to or higher than the upper limit voltage (charge termination voltage) of the predetermined voltage range. As another example, if the current charge / discharge process is a constant current discharging procedure, the termination condition of the charge / discharge process can be satisfied when the voltage sample value obtained in step S614 is equal to or lower than the lower limit voltage (discharge termination voltage) of the predetermined voltage range.

[0145] If the value of step S616 is “No”, the method of FIG. 6 can return to step S613.

[0146] The output value of step S616 being "Yes" indicates that the voltage of the battery cell (BC) has changed from one of the upper limit voltage and the lower limit voltage of a predetermined voltage range to the other due to the current charge / discharge process. If the output value of step S616 is "Yes", the method of FIG. 6 can proceed to step S618.

[0147] In step S618, the control unit (130) can generate a current differential voltage profile (302 in FIG. 4) for the current charge / discharge process. The current differential voltage profile represents a correspondence between the capacity of the battery cell (BC) and the differential voltage during the progress period of the current charge / discharge process.

[0148] In step S619, the control unit (130) performs peak detection for at least one of the first to nth interest ranges for the current differential voltage profile (302 in FIG. 4) to determine current degradation index information. For example, based on the first to nth interest peaks (P22, P23, P24, P26 in FIG. 4) detected from the current differential voltage profile, previous degradation index information may be updated to current degradation index information. The current degradation index information obtained as a result of step S619 may include a capacity value, a differential voltage value, and / or a kurtosis, etc., of at least one of the newly detected interest peaks (P22, P23, P24, P26) from the current differential voltage profile (302).

[0149] FIG. 7 is a flowchart referenced to exemplarily explain the subroutines of step S610 of FIG. 6.

[0150] In step S710, the control unit (130) can obtain the capacity value and kurtosis of the ith peak of interest (P[i]) from the previous degradation index information.

[0151] In step S711, the control unit (130) can set the upper limit of the ith interest range (R#i) based on the capacity value of the ith interest peak (P[i]).

[0152] It is obvious that the degradation of the battery cell (BC) will be more advanced during the execution period of the current charge / discharge process compared to the execution period of the previous charge / discharge process, and as the battery cell (BC) degrades, the differential capacity profile has the characteristic of shrinking to the left along the X-axis (horizontal axis), as described above. Therefore, considering that the capacity values ​​of the peaks of interest (P22, P23, P24, P26) to be detected from the differential voltage profile (302) to be obtained as a result of the (m+1) charge / discharge process are expected to be smaller than the capacity values ​​of the peaks of interest (P[1] to P[4]) previously detected through the previous charge / discharge process, the upper limit of the i-th range of interest (R#i) may be set equal to the capacity value of the i-th peak of interest (P[i]) previously detected through the previous charge / discharge process. Of course, the control unit (130) can variably set the first to nth interest ranges (R#1 to R#4 in FIG. 4), and can also set a capacity value greater than the capacity value of the i-th interest peak (P[i]) as the upper limit of the i-th interest range (R#i).

[0153] In step S712, the control unit (130) can determine the size of the ith interest range (R#i) based on the kurtosis of the ith interest peak (P[i]). For example, the control unit (130) can set the size of the ith interest range (R#i) based on the kurtosis of the ith interest peak (P[i]) by using a predetermined negative correspondence.

[0154] In steps S711 and S712, when the size and upper limit of the i-th interest range (R#i) among the first to n-th interest ranges (R#1 to R#4) are determined, the lower limit of the i-th interest range (R#i) is equal to a value obtained by subtracting the size from the upper limit.

[0155] FIG. 8 is a flowchart referenced to exemplarily explain the subroutines of step S611 of FIG. 6.

[0156] In step S810, the control unit (130) can obtain the kurtosis of the ith peak of interest (P[i]) from the previous degradation index information.

[0157] In step S812, the control unit (130) may determine the ith sampling rate based on the kurtosis of the ith peak of interest (P[i]). For example, the control unit (130) may obtain a reference coefficient (which may be greater than 1) corresponding to the kurtosis of the ith peak of interest (P[i]) from the storage unit (140), and then multiply the obtained reference coefficient by the reference sampling rate to determine the ith sampling rate. There may be a positive correspondence between the kurtosis of the peak and the reference coefficient, and relationship data defining this correspondence may be stored in advance in the storage unit (140).

[0158] In this regard, at least two of the first to nth sampling rates may be set to be equal to each other. For example, at least two of the first to nth sampling rates may be set to be equal to a value that is greater by a predetermined value or a predetermined ratio than the reference sampling rate. As another example, at least two of the first to nth sampling rates may be equal to a value obtained by multiplying the reference coefficient corresponding to the kurtosis of any one of the first to fourth peaks of interest (P[1] to P[4]) by the reference sampling rate.

[0159] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

[0160] 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.

[0161] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

Claims

1. A measuring unit configured to generate voltage sample values ​​and current sample values ​​of a battery cell; and A control unit configured to set first to nth interest ranges and first to nth sampling rates for the current charging and discharging process based on previous degradation indicator information associated with the previous charging and discharging process, The above control unit, During the progress of the above charging / discharging process, the voltage sample value and the current sample value of the battery cell are acquired at at least one sampling rate selected from the reference sampling rate and the first to nth sampling rates, A battery degradation indicator information acquisition device configured to perform peak detection for at least one of the first to nth ranges of interest from the current differential voltage profile of the battery cell generated based on the voltage sample value and the current sample value acquired during the progress period of the current charging and discharging process, thereby determining current degradation indicator information, wherein n is a natural number equal to or greater than 2.

2. In paragraph 1, The above control unit, during the progress of the charging and discharging process of the above-mentioned current assembly, If the capacity value of the battery cell falls within the i-th interest range among the first to n-th interest ranges, the i-th sampling rate is selected among the first to n-th sampling rates, When the capacity value of the battery cell is outside the first to nth interest ranges, the reference sampling rate is selected, A device for acquiring battery degradation indicator information, where i is a natural number less than or equal to n.

3. In paragraph 1, A device for acquiring battery degradation indicator information, wherein each of the first to nth sampling rates is greater than the reference sampling rate.

4. In paragraph 1, A device for acquiring battery degradation indicator information, wherein at least two of the first to nth sampling rates are identical to each other.

5. In paragraph 1, The above previous deterioration indicator information is, Containing peak feature data of at least one of the first to nth peaks of interest detected from the previous differential voltage profile, A device for acquiring battery degradation indicator information, wherein the above peak characteristic data represents at least one of a capacity value, a differential voltage value, or a kurtosis.

6. In paragraph 5, The above control unit, A battery degradation indicator information acquisition device configured to set the size of the ith interest range for the current charging / discharging process by applying a predetermined negative correspondence to the kurtosis of the ith interest peak included in the above-mentioned previous degradation indicator information, wherein i is a natural number less than or equal to n.

7. In paragraph 5, The above control unit, A battery degradation indicator information acquisition device configured to set an upper limit of an i-th interest range for the current charging / discharging process so as to be equal to a capacity value of an i-th interest peak among the first to n-th interest peaks included in the above-described previous degradation indicator information, wherein i is a natural number less than or equal to n.

8. In paragraph 5, The above control unit, A battery degradation indicator information acquisition device configured to set an ith sampling rate for the current charging / discharging process by applying a predetermined positive correspondence to the kurtosis of the ith peak of interest included in the above-mentioned previous degradation indicator information, wherein i is a natural number less than or equal to n.

9. A battery pack including a device for obtaining battery degradation indicator information according to any one of claims 1 to 8.

10. An electric vehicle comprising a battery pack according to Article 9.

11. A step of setting first to nth interest ranges and first to nth sampling rates for the current charging and discharging process based on previous degradation indicator information associated with the previous charging and discharging process; During the progress of the charging / discharging process of the above-described current assembly, a step of obtaining a voltage sample value and a current sample value of the battery cell at a predetermined reference sampling rate and at least one sampling rate selected from the first to nth sampling rates; A step of performing peak detection for at least one of the first to nth ranges of interest from the current differential voltage profile of the battery cell generated based on the voltage sample value and the current sample value acquired during the progress period of the current charging and discharging process, thereby determining current degradation index information; A method for obtaining battery degradation indicator information, wherein n is a natural number greater than or equal to 2.

12. In paragraph 11, The step of obtaining the voltage sample value and current sample value of the above battery cell is: During the charging and discharging process of the above-mentioned current meeting, the following steps are repeated: A step of obtaining a voltage sample value and a current sample value of the battery cell at an i-th sampling rate among the first to n-th sampling rates when the capacity value of the battery cell falls within an i-th interest range among the first to n-th interest ranges; and A step of obtaining a voltage sample value and a current sample value of the battery cell at the reference sampling rate when the capacity value of the battery cell is out of all of the first to nth interest ranges; A method for obtaining battery degradation indicator information, wherein i is a natural number less than or equal to n.

13. In paragraph 11, The above previous deterioration indicator information is, Containing peak feature data of at least one of the first to nth peaks of interest detected from the previous differential voltage profile, A method for obtaining battery degradation indicator information, wherein the above peak characteristic data represents at least one of a capacity value, a differential voltage value, or a kurtosis.

14. In paragraph 13, The upper limit of the i-th interest range for the charging / discharging process of the above-mentioned current meeting is A method for obtaining battery degradation indicator information, wherein the capacity value of the i-th peak of interest included in the above-mentioned previous degradation indicator information is set to be the same as that of the i-th peak of interest, wherein i is a natural number less than or equal to n.

15. In paragraph 13, The i-th sampling rate for the charging / discharging process of the above-mentioned present case is, A method for obtaining battery degradation indicator information, wherein the method is set to have a predetermined positive correspondence to the kurtosis of the i-th peak of interest included in the above-mentioned previous degradation indicator information, wherein i is a natural number less than or equal to n.

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