Apparatus and method for diagnosing battery

Abstract

An apparatus for diagnosing a battery, according to one embodiment of the present invention, comprises: a profile acquisition unit configured to acquire a battery profile indicating a corresponding relationship between the voltage and the capacity of a battery; and a control unit configured to divide a capacity section of the battery profile into a plurality of sections, derive, from each divided section, a target value for any one target indicator associated with a differential capacity peak or resistance among a plurality of preset diagnostic indicators, compare a corresponding relationship between the derived plurality of target values with a reference profile preset so as to indicate a corresponding relationship between the plurality of target indicators, and diagnose the state of the battery according to the comparison result.

Description

Battery diagnostic device and method

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0015281, filed January 31, 2024, the entire contents of which are incorporated herein by reference.

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

[0003] 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.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen 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.

[0005] While extensive research is being conducted on these batteries to improve capacity and density, improving lifespan and safety is also crucial. To improve battery safety, technology is required to accurately diagnose the current battery condition.

[0006] The present invention provides a battery diagnosis device and method capable of diagnosing the status of a battery and controlling the battery based on the diagnosis results.

[0007] Various aspects of the present invention can be understood through the following description and will be more clearly understood through the examples of the present invention. Furthermore, it will be readily apparent that various aspects of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0008] A battery diagnosis device according to one aspect of the present invention may include a profile acquisition unit configured to acquire a battery profile indicating a correspondence between a voltage and a capacity of a battery; and a control unit configured to divide a capacity section of the battery profile into a plurality of sections, derive a target value for any one target index related to a differential capacity peak or resistance among a plurality of preset diagnostic indices in each of the divided sections, compare a correspondence between the derived plurality of target values ​​with a preset reference profile indicating a correspondence between the plurality of target indices, and diagnose a state of the battery based on a result of the comparison.

[0009] The control unit may be configured to determine the number of a plurality of differential capacity peaks included in the differential profile representing a correspondence between voltage and differential capacity as a differential profile corresponding to the battery profile, an area of ​​the differential profile, a voltage of a main peak among the plurality of differential capacity peaks, or a differential capacity of the main peak as a target indicator corresponding to a low-capacity section among the plurality of sections.

[0010] The above control unit may be configured to determine the resistance as a target indicator corresponding to a high-capacity section among the plurality of sections.

[0011] The control unit may be configured to diagnose the state of the battery as a positive and negative deterioration state when a target point indicating a correspondence relationship between the plurality of target values ​​is included in the reference profile.

[0012] The control unit may be configured to diagnose the state of the battery as a negative deterioration state when the target point is included in the first area based on the reference profile.

[0013] The control unit may be configured to diagnose the state of the battery as a positive deterioration state when the target point is included in the second area based on the reference profile.

[0014] The control unit may be configured to diagnose the state of the battery as an EOL (End of Life) state when the target point is included in the third area.

[0015] The third region may be configured to be preset as a region exceeding a preset threshold for each of the plurality of target indicators.

[0016] The control unit may be configured to reduce at least one of an upper limit C-rate (Current-rate) and a constant voltage charging time set for the battery when the state of the battery is diagnosed as the positive deterioration state or the positive-negative deterioration state.

[0017] The control unit may be configured to reduce the upper charge limit voltage set for the battery when the state of the battery is diagnosed as the negative deterioration state or the positive deterioration state.

[0018] The above control unit may be configured to divide the capacity section into a first section and a second section based on a preset division ratio or target capacity.

[0019] The above profile acquisition unit may be configured to further acquire a differential profile corresponding to the battery profile.

[0020] The above control unit may be configured to determine a main peak in the differential profile and to divide the capacity section based on the capacity of the determined main peak.

[0021] The above differential profile can be configured to represent a correspondence between the capacity of the battery and the differential voltage.

[0022] The control unit may be configured to determine a plurality of minimum points in the differential profile, and determine a minimum point having the smallest corresponding differential voltage among the determined plurality of minimum points as the main peak.

[0023] The above differential profile can be configured to represent a correspondence between the voltage and differential capacity of the battery.

[0024] The control unit may be configured to determine a plurality of local maxima in the differential profile, and determine a local maxima having the largest corresponding differential voltage among the determined local maxima as the main peak.

[0025] 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.

[0026] A vehicle according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0027] A battery diagnosis method according to another aspect of the present invention may include a profile acquisition step of acquiring a battery profile indicating a correspondence between a voltage and a capacity of a battery; a section division step of dividing a capacity section of the battery profile into a plurality of sections; a target value derivation step of deriving a target value for any one target indicator related to a differential capacity peak or resistance among a plurality of preset diagnostic indicators in each section; a comparison step of comparing a correspondence between the plurality of derived target values ​​with a preset reference profile indicating a correspondence between the plurality of target indicators; and a diagnosis step of diagnosing a state of the battery based on a comparison result.

[0028] According to another aspect of the present invention, a non-transitory computer-readable storage medium may store a computer program for executing a battery diagnosis method, the method comprising: a profile acquisition step of acquiring a battery profile indicating a correspondence between a voltage and a capacity of a battery; a section division step of dividing a capacity section of the battery profile into a plurality of sections; a target value derivation step of deriving a target value for any one target indicator related to a differential capacity peak or resistance among a plurality of preset diagnostic indicators in each of the divided sections; a comparison step of comparing a correspondence between the plurality of derived target values ​​with a preset reference profile indicating a correspondence between the plurality of target indicators; and a diagnosis step of diagnosing a state of the battery based on a result of the comparison.

[0029] A battery diagnostic device according to one aspect of the present invention can diagnose the status of a battery from various aspects based on a combination of various target indicators.

[0030] Since the target value for each section is a value indicating the status of the battery corresponding to the section, the status of the battery can be diagnosed more precisely based on the correspondence between multiple target values.

[0031] 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.

[0032] The following drawings attached to this specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0033] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0034] FIG. 2 is a diagram schematically illustrating a battery profile according to one embodiment of the present invention.

[0035] FIG. 3 is a diagram schematically illustrating a plurality of target indicators according to one embodiment of the present invention.

[0036] FIG. 4 is a drawing schematically illustrating a reference profile according to one embodiment of the present invention.

[0037] FIG. 5 is a schematic diagram illustrating a differential profile according to one embodiment of the present invention.

[0038] FIG. 6 is a schematic drawing of a battery pack according to another embodiment of the present invention.

[0039] Figure 7 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0040] FIG. 8 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.

[0041] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.

[0042] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely 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.

[0043] In addition, when describing the present invention, if it is determined that the description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

[0044] 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.

[0045] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0046] 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.

[0047] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings.

[0048] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0049] Referring to FIG. 1, the battery diagnostic device (100) may include a profile acquisition unit (110), a control unit (120), and a storage unit (130).

[0050] Here, a battery refers to a physically separate, independent cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. Furthermore, the battery may be of a cylindrical type, a prismatic type, or a pouch type. Furthermore, a battery may also refer to a battery bank, a battery module, or a battery pack in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be described herein below as referring to a single, independent cell.

[0051] The profile acquisition unit (110) may be configured to acquire a battery profile (BP) indicating a correspondence between the voltage and capacity of the battery.

[0052] For example, a battery profile (BP) is a profile that represents the relationship between voltage (V) and capacity (Q) when the battery's capacity is charged from a preset start charge capacity or 0% to a preset end charge capacity or 100%. As another example, a battery profile (BP) may represent the relationship between voltage (V) and capacity (Q) when the battery's capacity is discharged from a preset start discharge capacity or 100% to a preset end discharge capacity or 0%.

[0053] For example, there are no specific restrictions on the current rate (C-rate) during charging or discharging to generate a battery profile (BP). However, to obtain more accurate battery profiles (BP) and differential profiles, the battery must be charged or discharged at a low rate. For example, a battery profile (BP) can be generated during the process of charging or discharging a battery at 0.05C.

[0054] The profile acquisition unit (110) can acquire a battery profile (BP) in the following manner.

[0055] For example, the profile acquisition unit (110) can directly read or receive the battery profile (BP) of the battery from the outside. For example, the profile acquisition unit (110) can acquire the battery profile (BP) by reading or receiving the battery profile (BP) through a wired and / or wireless connection to the outside.

[0056] As another example, the profile acquisition unit (110) can directly generate a battery profile (BP) based on battery information regarding the voltage and capacity of the battery. For example, the profile acquisition unit (110) can acquire a battery profile (BP) by directly generating the battery profile (BP) based on the battery information.

[0057] FIG. 2 is a diagram schematically illustrating a battery profile (BP) according to one embodiment of the present invention. In the embodiment of FIG. 2, the battery profile (BP) can be expressed as an XY graph in which the X-axis is set to capacity (Q) and the Y-axis is set to voltage (V).

[0058] The profile acquisition unit (110) may be connected to the control unit (120) so as to be able to communicate with it. For example, the profile acquisition unit (110) may be connected to the control unit (120) by wire and / or wirelessly. As an example, the profile acquisition unit (110) may transmit the acquired battery profile (BP) to the control unit (120). As another example, the control unit (120) may read the battery profile (BP) from the profile acquisition unit (110).

[0059] According to one embodiment, the control unit (120) may be configured to divide the capacity section of the battery profile (BP) into a plurality of sections.

[0060] For example, the control unit (120) can divide the entire capacity section of the battery profile (BP) into two or more sections. For example, in the embodiment of FIG. 2, the entire capacity section of the battery profile (BP) is Qi to Qf. The control unit (120) can divide the capacity section of Qi to Qf into a first section (R1) and a second section (R2) based on Qk.

[0061] The control unit (120) may be configured to derive a target value for any one target indicator related to differential capacity peak or resistance among a plurality of preset diagnostic indicators in each section.

[0062] For example, multiple diagnostic indicators can be preset for each of multiple sections. These diagnostic indicators represent the battery's condition within that section and can be used to diagnose the battery's condition within that section. For example, since there are unique indicators that can only be derived from each of the multiple sections, some or all of the diagnostic indicators set for each of the multiple sections may be different.

[0063] FIG. 3 is a diagram schematically illustrating a plurality of target indicators according to one embodiment of the present invention.

[0064] (1) The number of differential voltage peaks is the number of peaks included in the corresponding section of the first differential profile. For example, the number of local maxima and / or local minima included in the corresponding section of the first differential profile can be determined as the number of differential voltage peaks.

[0065] A differential voltage peak refers to a peak included in a first differential profile obtained by differentiating the battery profile (BP) with respect to capacity. For example, when the battery profile (BP) is differentiated with respect to capacity, a first differential profile representing a correspondence between the capacity (Q) and the differential voltage (dV / dQ) can be derived. Furthermore, the first differential profile may include multiple differential voltage peaks. Here, the differential voltage peaks refer to local maxima and / or local minima included in the first differential profile.

[0066] (2) The capacity of the differential voltage peak is the capacity of the target peak included in the corresponding section of the first differential profile. For example, among one or more local maxima included in the corresponding section of the first differential profile, the peak with the largest corresponding differential voltage may be determined as the target peak. The target peak may vary depending on the condition of the battery to be diagnosed.

[0067] (3) The differential voltage of the differential voltage peak is the differential voltage of the target peak included in the corresponding section of the first differential profile.

[0068] (4) The differential voltage area is the area of ​​the corresponding section of the first differential profile. The integrated value for the capacity in the corresponding section of the first differential profile can be determined as the differential voltage area.

[0069] (5) The number of differential capacity peaks is the number of peaks included in the corresponding section of the second differential profile. For example, the number of local maxima and / or local minima included in the corresponding section of the second differential profile can be determined as the number of differential voltage peaks.

[0070] Here, the differential capacity peak refers to a peak included in a second differential profile obtained by differentiating the battery profile (BP) with respect to voltage. For example, when the battery profile (BP) is differentiated with respect to voltage, a second differential profile representing a correspondence between voltage (V) and differential capacity (dQ / dV) can be derived. In addition, the second differential profile may include multiple differential capacity peaks. Here, the differential capacity peak refers to a maximum point and / or minimum point included in the second differential profile.

[0071] (6) The voltage of the differential capacity peak is the voltage of the target peak included in the corresponding section of the second differential profile. For example, among one or more local maxima included in the corresponding section of the second differential profile, the peak with the largest corresponding differential capacity may be determined as the target peak. The target peak may vary depending on the condition of the battery to be diagnosed.

[0072] (7) The differential capacity of the differential capacity peak is the differential capacity of the target peak included in the corresponding section of the second differential profile.

[0073] (8) The differential capacitance area is the area of ​​the corresponding section of the second differential profile. The integrated value for voltage in the corresponding section of the second differential profile can be determined as the differential capacitance area.

[0074] (9) The discharge termination voltage refers to the open circuit voltage (OCV) after the battery discharge is complete. Since the discharge termination voltage can only be determined after the battery discharge is complete, it is a diagnostic indicator that can only be determined in low-capacity sections. For example, the discharge termination voltage can be determined in a low-capacity section corresponding to the voltage set to terminate battery discharge.

[0075] (10) The charge termination voltage refers to the OCV after the battery's charging is complete. Since the charge termination voltage can only be determined when the battery's charging is complete, it is a diagnostic indicator that can only be determined in the high-capacity range. For example, the charge termination voltage can be determined in the high-capacity range corresponding to the voltage set to terminate battery charging.

[0076] (11) Section resistance means the ratio of voltage change to charge / discharge current of the section.

[0077] (12) Charging efficiency refers to the difference between the charging capacity and the discharging capacity. For example, the charging efficiency of the low-capacity section in the nth cycle can be calculated according to the formula “charge capacity of the nth cycle - discharge capacity of the nth cycle.” And, the charging efficiency of the high-capacity section in the nth cycle can be calculated according to the formula “discharge capacity of the nth cycle - charge capacity of the n+1th cycle.” For example, the charging efficiency is not limited to the section, but can be calculated according to the entire charge / discharge capacity of the cycle.

[0078] (13) Interval capacity refers to the capacity of the corresponding interval.

[0079] (14) The CC charge capacity ratio refers to the ratio of the CC charge capacity to the CC (constant current) charge capacity and the CV (constant voltage) charge capacity. Since CV charging occurs at the end of the charge, the CC charge capacity ratio is a diagnostic indicator that can only be derived in the high-capacity section. For example, the CC charge capacity ratio can be derived in the high-capacity section corresponding to the voltage set to terminate battery charging.

[0080] In one embodiment, the control unit (120) may determine a diagnostic indicator related to a differential capacity peak or resistance among the plurality of diagnostic indicators described above for each of the plurality of sections as a target indicator.

[0081] For example, the control unit (120) may be configured to determine the number of a plurality of differential capacity peaks included in the differential profile representing the correspondence between voltage and differential capacity as a differential profile corresponding to the battery profile (BP), the area of ​​the differential profile, the voltage of a main peak among the plurality of differential capacity peaks, or the differential capacity of the main peak as a target indicator corresponding to a low-capacity section among the plurality of sections.

[0082] In this way, in the embodiment of FIG. 3, the control unit (120) can determine any one of the number of differential capacity peaks, the voltage of the differential capacity peak, the differential capacity of the differential capacity peak, and the differential capacity area as a target indicator for the low capacity section.

[0083] Additionally, the control unit (120) may be configured to determine the resistance as a target indicator corresponding to a high-capacity section among multiple sections.

[0084] In this way, in the embodiment of FIG. 3, the control unit (120) can determine the section resistance as a target indicator for the high-capacity section.

[0085] The control unit (120) may be configured to compare the correspondence between the derived plurality of target values ​​with a preset reference profile to indicate the correspondence between the plurality of target indicators.

[0086] According to one embodiment, it is assumed that the capacity section of the battery profile (BP) is divided into a first section (R1) and a second section (R2), a first target value for a target indicator is derived from the first section (R1), and a second target value for the target indicator is derived from the second section (R2). The control unit (120) can compare target points indicating a correspondence relationship between a plurality of target values ​​with a reference profile.

[0087] Fig. 4 is a schematic diagram illustrating a reference profile according to one embodiment of the present invention. In the embodiment of Fig. 4, the reference profile can be expressed as an XY graph in which the X-axis is set to a second target value and the Y-axis is set to a first target value.

[0088] For example, the control unit (120) can determine whether the target point is included in the reference profile. If the target point is not included in the reference profile, the control unit (120) can determine which of the first region (T1), the second region (T2), and the third region (T3) the target point is included in.

[0089] The first region (T1) is a region in which the first target value is greater than the reference profile. For example, in the embodiment of FIG. 4, the first region (T1) is a region in which the first target value of a target point exceeds the first target value of the reference profile based on the same second target value.

[0090] The second region (T2) is a region in which the second target value is greater than the reference profile. For example, in the embodiment of Fig. 4, the second region (T2) is a region in which the second target value of the target point exceeds the second target value of the reference profile based on the same first target value.

[0091] The third region (T3) may be configured to be preset as a region exceeding a preset threshold for each of a plurality of target indicators. The thresholds may be independently set for each of the first target value and the second target value. For example, in the embodiment of FIG. 4, the third region (T3) is a region where the first target value of the target point exceeds the first threshold value (th1) and the second target value of the target point exceeds the second threshold value (th2).

[0092] In the embodiment of FIG. 4, the target point may be included in the reference profile, the first area (T1), the second area (T2), or the third area (T3).

[0093] The control unit (120) may be configured to diagnose the status of the battery based on the comparison result.

[0094] For example, the control unit (120) may be configured to diagnose the battery's condition as a positive and negative deterioration state if a target point representing a correspondence relationship between multiple target values ​​is included in the reference profile. The positive and negative deterioration state is a state in which both the positive and negative poles of the battery are deteriorated, and the deterioration degrees of the positive and negative poles are balanced.

[0095] As another example, the control unit (120) may be configured to diagnose the battery status as a negative electrode deterioration state when the target point is included in the first region (T1) based on the reference profile. Here, the negative electrode deterioration state is a state in which the deterioration of the negative electrode of the battery is more dominant than the deterioration of the positive electrode. For example, the negative electrode deterioration state is a state in which the deterioration of the positive and negative electrodes is not balanced, and the deterioration of the negative electrode has progressed more than the deterioration of the positive electrode. For example, the negative electrode deterioration state is related to the loss of available lithium. When available lithium is lost, lithium plating, in which lithium metal is deposited on the surface of the negative electrode, may occur.

[0096] As another example, the control unit (120) may be configured to diagnose the battery status as a positive electrode deterioration state if the target point is included in the second region (T2) based on the reference profile. Here, the positive electrode deterioration state refers to a state in which the positive electrode of the battery is deteriorated, and the deterioration of the positive electrode is more dominant than the deterioration of the negative electrode. For example, the positive electrode deterioration state refers to a state in which the deterioration of the positive and negative electrodes is not balanced, and the deterioration of the positive electrode is more advanced than the deterioration of the negative electrode.

[0097] As another example, the control unit (120) may be configured to diagnose the battery's condition as end-of-life (EOL) if the target point falls within the third region (T3). The EOL condition refers to a state in which the battery's deterioration has progressed significantly, making its use undesirable. For example, the EOL condition may be a condition in which the battery is judged to be unusable.

[0098] A battery diagnostic device (100) according to one embodiment of the present invention can diagnose the condition of a battery based on the correspondence between target values ​​calculated in each of a plurality of sections. For example, according to one embodiment of the present invention, the condition of a battery can be diagnosed from various aspects based on a combination of various target indicators.

[0099] Since the target value for each section is a value indicating the status of the battery corresponding to the section, the status of the battery can be diagnosed in more detail based on the correspondence relationship between multiple target values.

[0100] The profile acquisition unit (110) and the control unit (120) provided in the battery diagnostic device (100) may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, etc. known in the art to execute various control logics performed in the present invention. In addition, when the control logic is implemented in software, the profile acquisition unit (110) and the control unit (120) may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the profile acquisition unit (110) and the control unit (120). The memory may be located inside or outside the profile acquisition unit (110) and the control unit (120), and may be connected to the profile acquisition unit (110) and the control unit (120) by various well-known means.

[0101] The battery diagnostic device (100) may further include a storage unit (130). The storage unit (130) may store data or programs required for each component of the battery diagnostic device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (130) is not particularly limited in type as long as it is a known information storage means that is known to be able to record, erase, update, and read data. As an example, the information storage means may include a RAM (Random Access Memory), a flash memory, a ROM (Read-Only Memory), an EEPROM (Electronically Erasable Programmable Read-Only Memory), a register, etc. In addition, the storage unit (130) may store program codes defining processes that can be executed by the profile acquisition unit (110) and the control unit (120).

[0102] For example, the storage unit (130) can store battery information, a battery profile (BP), a differential profile, and battery diagnosis information by the control unit (120).

[0103] The control unit (120) may be configured to control the battery based on the diagnosis results regarding the battery's condition. For example, the control unit (120) may change the battery's usage conditions based on the diagnosis results.

[0104] For example, if the control unit (120) is diagnosed as a positive deterioration state or a positive / negative deterioration state of the battery, the control unit (120) may be configured to reduce at least one of the upper limit C-rate and the constant voltage charge time set for the battery. For example, if the control unit (120) is diagnosed as having deteriorated the positive electrode of the battery, the control unit (120) may change the usage conditions of the battery to prevent further deterioration of the positive electrode of the battery.

[0105] As another example, the control unit (120) may be configured to reduce the set upper charge limit voltage for the battery if the battery is diagnosed as a negative electrode deteriorated state or a positive electrode deteriorated state. If the negative electrode of the battery is diagnosed as deteriorated, the control unit (120) may change the usage conditions of the battery to prevent further deterioration of the negative electrode of the battery.

[0106] As the battery's usage conditions change, the battery's life expectancy may be increased because the deterioration of the battery's positive and / or negative electrodes may be slowed.

[0107] The control unit (120) can be configured to divide the capacity section into a first section (R1) and a second section (R2) based on a preset division ratio or target capacity.

[0108] In one embodiment, the control unit (120) may divide the capacity sections based on a preset ratio. For example, the control unit (120) may divide the capacity sections at a ratio of n:m (where n and m are positive numbers) to set the lower capacity section as the first section (R1) and the upper capacity section as the second section (R2).

[0109] For example, assume that the starting capacity is Qi and the ending capacity is Qf. In addition, assume that the capacity corresponding to the ratio of n:m is Qk, and Qk can be calculated according to the formula of "(Qf-Qi)÷(n+m)×n". The control unit (120) can set the capacity section of Qi to Qk as the first section (R1). In addition, the control unit (120) can set the capacity section of Qk to Qf as the second section (R2).

[0110] In another embodiment, the control unit (120) can distinguish the capacity intervals using a differential profile based on the battery profile (BP).

[0111] The profile acquisition unit (110) may be configured to further acquire a differential profile corresponding to the battery profile (BP).

[0112] For example, when the battery profile (BP) is differentiated with respect to capacity, a differential profile can be generated that represents the correspondence between the differential voltage (dV / dQ) and the capacity (Q). Furthermore, when the battery profile (BP) is differentiated with respect to voltage, a differential profile can be generated that represents the correspondence between the differential capacity (dQ / dV) and the voltage (V).

[0113] For example, the profile acquisition unit (110) can directly read or receive the differential profile of the battery from an external source. For example, the profile acquisition unit (110) can acquire the differential profile by reading or receiving the differential profile while being connected to the external source via wire and / or wirelessly.

[0114] As another example, the profile acquisition unit (110) can directly read or receive a battery profile (BP) of a battery from an external source and generate a differential profile based on the battery profile (BP). For example, the profile acquisition unit (110) can be connected to the external source via wires and / or wirelessly to read or receive a battery profile (BP) and directly generate a differential profile from the battery profile (BP), thereby acquiring a differential profile.

[0115] As another example, the profile acquisition unit (110) can generate a battery profile (BP) based on battery information regarding the voltage and capacity of the battery, and generate a differential profile based on the generated battery profile (BP). In this way, the profile acquisition unit (110) can acquire a differential profile by directly generating the differential profile based on the battery information.

[0116] The profile acquisition unit (110) may be connected to the control unit (120) so as to be able to communicate with it. For example, the profile acquisition unit (110) may be connected to the control unit (120) by wire and / or wirelessly. As an example, the profile acquisition unit (110) may transmit the acquired differential profile to the control unit (120). As another example, the control unit (120) may read the differential profile from the profile acquisition unit (110).

[0117] In one embodiment, the differential profile acquired by the profile acquisition unit (110) may be configured to indicate a correspondence between the capacity (Q) of the battery and the differential voltage (dV / dQ).

[0118] FIG. 5 is a schematic diagram illustrating a differential profile (DP) according to one embodiment of the present invention. In the embodiment of FIG. 5, the differential profile (DP) can be expressed as an XY graph in which the X-axis is set to the capacity (Q) and the Y-axis is set to the differential voltage (dV / dQ). For example, the differential profile (DP) of FIG. 5 has the same shape as the first differential profile of FIG. 3.

[0119] The control unit (120) may be configured to determine a main peak (tp) in the differential profile (DP).

[0120] For example, the control unit (120) may be configured to determine a plurality of minimum points in the differential profile (DP). For example, in the embodiment of FIG. 5, the differential profile (DP) may include first to fifth minimum points (p1, p2, p3, p4, p5).

[0121] According to one embodiment, the control unit (120) may be configured to determine, among the plurality of determined minimum points, the minimum point with the smallest corresponding differential voltage as the main peak (tp). For example, in the embodiment of FIG. 5, since the differential voltage corresponding to the third minimum point (p3) among the plurality of minimum points (p1, p2, p3, p4, and p5) is the smallest, the control unit (120) may determine the third minimum point (p3) as the main peak (tp).

[0122] The control unit (120) may be configured to divide the capacity section based on the capacity of the determined main peak (tp). For example, in the embodiment of FIG. 5, if the capacity of the main peak (tp) is Qk, the control unit (120) may divide the capacity section into a first section (R1) of Qi to Qk and a second section (R2) of Qk to Qf.

[0123] In general, based on the minimum point where the differential voltage is the smallest, the low-capacity side reflects the state of the battery's negative pole, and the high-capacity side reflects the state of the battery's positive pole. Therefore, the control unit (120) can distinguish the battery's capacity range based not only on a certain ratio (n:m) but also on the main peak (tp).

[0124] As another example, the control unit (120) may determine the minimum point, which is included in the lower-middle capacity range of the battery and has the smallest corresponding differential voltage, as the main peak (tp).

[0125] In general, if the capacity section of a battery is divided into a low-capacity section and a high-capacity section, the minimum point with the smallest differential voltage is included in the low-capacity section. Therefore, the control unit (120) can determine the main peak (tp) in the battery's mid-capacity section (low-capacity section). For example, the control unit (120) can save the time and system resources required to determine the main peak (tp) by determining the main peak (tp) from among multiple minimum points included in the low-capacity section.

[0126] For example, in the embodiment of FIG. 5, the low-capacity section includes first to third minimum points (p1, p2, p3). The control unit (120) may determine the third minimum point (p3) with the smallest differential voltage among the first to third minimum points (p1, p2, p3) as the main peak (tp).

[0127] Thus, since the full-capacity and low-capacity sections contain different numbers of local minima, the time and system resources required to compare the differential voltages of multiple local minima may also differ. Therefore, by considering only local minima within the low-capacity section, the control unit can more quickly determine the main peak.

[0128] In another embodiment, the differential profile (DP) acquired by the profile acquisition unit (110) may be configured to indicate a correspondence between the voltage (V) and the differential capacity (dQ / dV) of the battery.

[0129] The control unit (120) may be configured to determine multiple local maxima in the differential profile (DP). Local maxima, as opposed to local minima, refer to points in the differential profile (DP) that have an upward convex shape.

[0130] In addition, the control unit (120) can be configured to determine the maximum point with the largest corresponding differential voltage among the determined multiple maximum points as the main peak.

[0131] The battery diagnosis device (100) according to the present invention can be applied to a BMS (Battery Management System). For example, the BMS according to the present invention can include the battery diagnosis device (100) described above. In this configuration, at least some of the components of the battery diagnosis device (100) can be implemented by supplementing or adding to the functions of the components included in a conventional BMS. For example, the profile acquisition unit (110), the control unit (120), and the storage unit (130) of the battery diagnosis device (100) can be implemented as components of the BMS.

[0132] Additionally, the battery diagnostic device (100) according to the present invention may be installed in a battery pack. Furthermore, the battery pack according to the present invention may include the battery diagnostic device (100) described above and one or more battery cells. Furthermore, the battery pack may further include electrical components (relays, fuses, etc.) and a case.

[0133] FIG. 6 is a schematic drawing of a battery pack (10) according to another embodiment of the present invention.

[0134] The positive terminal of the battery (11) can be connected to the positive terminal (P+) of the battery pack (10), and the negative terminal of the battery (11) can be connected to the negative terminal (P-) of the battery pack (10).

[0135] The measuring unit (12) can be connected to a first sensing line (SL1), a second sensing line (SL2), and a third sensing line (SL3). For example, the measuring unit (12) can be connected to a positive terminal of the battery (11) through the first sensing line (SL1), and can be connected to a negative terminal of the battery (11) through the second sensing line (SL2). The measuring unit (12) can measure the voltage of the battery (11) based on the voltage measured at each of the first sensing line (SL1) and the second sensing line (SL2).

[0136] And, the measuring unit (12) can be connected to the current measuring unit (A) through the third sensing line (SL3). For example, the current measuring unit (A) can be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery (11). The measuring unit (12) can measure the charging current of the battery (11) through the third sensing line (SL3) to calculate the charging amount. In addition, the measuring unit (12) can measure the discharging current of the battery (11) through the third sensing line (SL3) to calculate the discharging amount.

[0137] For example, the profile acquisition unit (110) can read or receive battery information about the voltage and current of the battery from the measurement unit (12) and generate a battery profile (BP) and a differential profile (DP) based on the battery information.

[0138] As another example, the profile acquisition unit (110) can read or receive a battery profile (BP) from the measurement unit (12) and generate a differential profile (DP) based on the battery profile (BP).

[0139] As another example, the profile acquisition unit (110) can read or receive a differential profile (DP) from the measurement unit (12).

[0140] An external device may be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (10). For example, the external device may be a charging device or a load. In addition, the positive terminal of the battery (11), the positive terminal (P+) of the battery pack (10), the external device, the negative terminal (P-) of the battery pack (10), and the negative terminal of the battery (11) may be electrically connected.

[0141] FIG. 7 is a schematic drawing of a vehicle (700) according to another embodiment of the present invention.

[0142] Referring to FIG. 7, a battery pack (710) according to an embodiment of the present invention may be included in a vehicle (700), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (710) may drive the vehicle (700) by supplying power to a motor through an inverter provided in the vehicle (700). Here, the battery pack (710) provided in the vehicle may include a battery diagnostic device (100) according to an embodiment of the present invention. In this case, the battery diagnostic device (100) may be an onboard device included in the vehicle (700).

[0143] FIG. 8 is a schematic diagram illustrating a battery diagnosis method according to another embodiment of the present invention.

[0144] Referring to FIG. 8, the battery diagnosis method may include a profile acquisition step (S100), an interval division step (S200), a target value derivation step (S300), a comparison step (S400), and a diagnosis step (S500).

[0145] Each step of the battery diagnosis method can be performed by the battery diagnosis device (100). In the following, for convenience of explanation, any content that overlaps with the previously described content will be omitted or briefly described.

[0146] The profile acquisition step (S100) is a step of acquiring a battery profile (BP) indicating a correspondence between the voltage and capacity of the battery, and can be performed by the profile acquisition unit (110).

[0147] For example, the profile acquisition unit (110) can directly read or receive the battery profile (BP) of the battery from the outside. For example, the profile acquisition unit (110) can acquire the battery profile (BP) by reading or receiving the battery profile (BP) through a wired and / or wireless connection to the outside.

[0148] As another example, the profile acquisition unit (110) can generate a battery profile (BP) based on battery information regarding the voltage and capacity of the battery. In this way, the profile acquisition unit (110) can acquire a battery profile (BP) by directly generating the battery profile (BP) based on read or received battery information.

[0149] The section division step (S200) is a step of dividing the capacity section of the battery profile (BP) into multiple sections, and can be performed by the control unit (120).

[0150] According to one embodiment, the control unit (120) may divide the entire capacity range of the battery profile (BP) into two or more ranges. For example, in the embodiment of FIG. 2, the entire capacity range of the battery profile (BP) is Qi to Qf. The control unit (120) may divide the capacity range of Qi to Qf into a first range (R1) and a second range (R2) based on Qk.

[0151] The target value derivation step (S300) is a step of deriving a target value for one target indicator related to differential capacity peak or resistance among a plurality of diagnostic indicators preset in each section, and can be performed by the control unit (120).

[0152] For example, in the embodiment of FIG. 3, the control unit (120) can select a target indicator for each of the first section (R1) and the second section (R2). Then, the control unit (120) can derive a target value corresponding to the selected target indicator.

[0153] The comparison step (S400) is a step of comparing the correspondence between the derived plurality of target values ​​with a preset reference profile to indicate the correspondence between the plurality of target indicators, and can be performed by the control unit (120).

[0154] According to one embodiment, when a capacity section of a battery profile (BP) is divided into a first section (R1) and a second section (R2), and a first target value for a target indicator is derived in the first section (R1) and a second target value for the target indicator is derived in the second section (R2), the control unit (120) can compare target points indicating a correspondence relationship between a plurality of target values ​​with a reference profile.

[0155] For example, in the embodiment of FIG. 4, the control unit (120) can determine whether the target point is included in the reference profile. If the target point is not included in the reference profile, the control unit (120) can determine which of the first region (T1), the second region (T2), and the third region (T3) the target point is included in.

[0156] The diagnosis step (S500) is a step for diagnosing the status of the battery based on the comparison result, and can be performed by the control unit (120).

[0157] For example, in the embodiment of FIG. 4, the control unit (120) can diagnose the state of the battery as a positive and negative deterioration state if the target point is included in the reference profile.

[0158] As another example, the control unit (120) can diagnose the state of the battery as a negative deterioration state when the target point is included in the first area (T1).

[0159] As another example, the control unit (120) can diagnose the state of the battery as a positive deterioration state when the target point is included in the second area (T2).

[0160] As another example, the control unit (120) can diagnose the battery status as an EOL status when the target point is included in the third area (T3).

[0161] 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.

[0162] 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.

[0163] 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.

[0164] (Explanation of symbols)

[0165] 10: Battery pack

[0166] 11: Battery

[0167] 12: Measurement section

[0168] 100: Battery Diagnostic Device

[0169] 110: Profile acquisition section

[0170] 120: Control unit

[0171] 130: Storage

[0172] 700: Car

[0173] 710: Battery Pack

Claims

1. A profile acquisition unit configured to acquire a battery profile indicating a correspondence between the voltage and capacity of the battery; and A battery diagnostic device comprising a control unit configured to divide the capacity section of the above battery profile into a plurality of sections, derive a target value for one target indicator related to a differential capacity peak or resistance among a plurality of preset diagnostic indicators in each of the divided sections, compare the correspondence between the derived plurality of target values with a preset reference profile that indicates the correspondence between the plurality of target indicators, and diagnose the state of the battery based on the comparison result.

2. In paragraph 1, The above control unit, The number of a plurality of differential capacity peaks included in the differential profile representing the correspondence between voltage and differential capacity as a differential profile corresponding to the battery profile, the area of the differential profile, the voltage of the main peak among the plurality of differential capacity peaks or the differential capacity of the main peak are determined as target indicators corresponding to the low-capacity section among the plurality of sections, A battery diagnostic device configured to determine the above resistance as a target indicator corresponding to a high-capacity section among the plurality of sections.

3. In paragraph 1, The above control unit, If a target point indicating a correspondence relationship between the plurality of target values is included in the reference profile, the state of the battery is diagnosed as a positive and negative deterioration state, If the target point is included in the first area based on the reference profile, the state of the battery is diagnosed as a negative deterioration state, A battery diagnostic device configured to diagnose the state of the battery as a bipolar deterioration state when the target point is included in the second area based on the reference profile.

4. In paragraph 3, The above control unit, If the target point is included in the third area, the state of the battery is configured to be diagnosed as EOL (End of Life) state, The third area above is, A battery diagnostic device configured to be preset to an area exceeding a preset threshold value for each of the plurality of target indicators.

5. In paragraph 3, The above control unit, A battery diagnostic device configured to reduce at least one of an upper limit C-rate (Current-rate) and a constant voltage charging time set for the battery when the state of the battery is diagnosed as the positive deterioration state or the positive-negative deterioration state.

6. In paragraph 3, The above control unit, A battery diagnostic device configured to reduce the upper charge limit voltage set for the battery when the state of the battery is diagnosed as the negative electrode deterioration state or the positive electrode deterioration state.

7. In paragraph 1, The above control unit, A battery diagnostic device configured to divide the capacity section into a first section and a second section based on a preset division ratio or target capacity.

8. In paragraph 7, The above profile acquisition unit, It is configured to further obtain a differential profile corresponding to the above battery profile, The above control unit, A battery diagnostic device configured to determine a main peak from the above differential profile and to divide the capacity section based on the capacity of the determined main peak.

9. In paragraph 8, The above differential profile is, It is configured to represent the correspondence between the capacity and differential voltage of the above battery, The above control unit, A battery diagnostic device configured to determine a plurality of minimum points in the above differential profile, and to determine a minimum point having the smallest corresponding differential voltage among the determined plurality of minimum points as the main peak.

10. In paragraph 8, The above differential profile is, It is configured to represent the correspondence between the voltage and differential capacity of the above battery, The above control unit, A battery diagnostic device configured to determine a plurality of local maxima in the above differential profile, and to determine a local maxima having the largest corresponding differential voltage among the determined local maxima as the main peak.

11. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 10.

12. A vehicle including a battery diagnostic device according to any one of claims 1 to 10.

13. A profile acquisition step for acquiring a battery profile indicating the correspondence between the voltage and capacity of the battery; A section division step for dividing the capacity section of the above battery profile into multiple sections; A target value derivation step for deriving a target value for any one target indicator related to differential capacity peak or resistance among a plurality of preset diagnostic indicators in each separated section; A comparison step for comparing the correspondence between the derived multiple target values with a preset reference profile to indicate the correspondence between the multiple target indicators; and A battery diagnosis method comprising a diagnosis step of diagnosing the condition of a battery based on a comparison result.

14. A profile acquisition step for acquiring a battery profile indicating the correspondence between the voltage and capacity of the battery; A section division step for dividing the capacity section of the above battery profile into multiple sections; A target value derivation step for deriving a target value for any one target indicator related to differential capacity peak or resistance among a plurality of preset diagnostic indicators in each separated section; A comparison step for comparing the correspondence between the derived multiple target values with a preset reference profile to indicate the correspondence between the multiple target indicators; and A non-transitory computer-readable storage medium storing a computer program for executing a battery diagnosis method including a diagnosis step of diagnosing the condition of a battery based on a comparison result.

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