Battery diagnosis apparatus and method

Abstract

A battery diagnosis apparatus according to an embodiment of the present invention may comprise: a profile acquisition unit configured to acquire a differential profile representing a correspondence relationship between voltage and differential capacity of a battery; and a control unit configured to determine a target peak from the differential profile, calculate a rate of change in the differential capacity of the target peak on the basis of preset peak data and the target peak, compare the calculated rate of change in the differential capacity with a preset threshold, and diagnose the state of the battery on the basis of a result of the comparison.

Description

Battery diagnostic device and method

[0001] This application is a priority claim application for Korean Patent Application No. 10-2024-0197967 filed on December 27, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0002] The present invention relates to a battery diagnostic device and method capable of specifically diagnosing the condition of a battery.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated, research on high-performance batteries capable of repeated charging and discharging is actively underway.

[0004] Currently commercialized batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium batteries. Among these, lithium batteries are gaining attention for their advantages, such as having almost no memory effect compared to nickel-based batteries, allowing for free charging and discharging, a very low self-discharge rate, and high energy density.

[0005] While much research is being conducted on these batteries in terms of increasing capacity and density, improving lifespan and safety is also important. To enhance battery safety, technology capable of accurately diagnosing the battery's current state is required.

[0006] The present invention is devised to solve the above-mentioned problems and aims to provide a battery diagnostic device and method for diagnosing the degradation state of a battery in detail.

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

[0008] A battery diagnostic device according to one aspect of the present invention may include: a profile acquisition unit configured to acquire a differential profile representing a correspondence relationship between the voltage and differential capacity of a battery; and a control unit configured to determine a target peak in the differential profile, calculate a differential capacity change rate of the target peak based on preset peak data and the target peak, compare the calculated differential capacity change rate with a preset threshold value, and diagnose the state of the battery based on the comparison result.

[0009] The above peak data can be pre-set to represent the correspondence between the voltage and differential capacitance of the target peak measured at a previous point in time.

[0010] The control unit may be configured to calculate the rate of change of the differential capacity with respect to the voltage of the target peak as the rate of change of differential capacity, based on the voltage of the target peak, the differential capacity, and the peak data.

[0011] The control unit may be configured to diagnose the state of the battery as normal when the differential capacity change rate is greater than or equal to the threshold value.

[0012] The control unit may be configured to diagnose the state of the battery as abnormal when the differential capacity change rate is below the threshold value.

[0013] The control unit may be configured to compare the differential capacity change rate with a second threshold value set to a value less than the threshold value, and based on the comparison result, diagnose the state of the battery as a first abnormal state in which degradation is accelerated or a second abnormal state in which lithium is precipitated.

[0014] The control unit may be configured to diagnose the state of the battery as the first abnormal state when the differential capacity change rate is less than the threshold value and greater than or equal to the second threshold value.

[0015] The control unit may be configured to diagnose the state of the battery as the second abnormal state when the differential capacity change rate is less than the second threshold value or when it is impossible to calculate the differential capacity change rate.

[0016] The control unit may be configured to determine the peak with the lowest corresponding voltage among a plurality of peaks included in the differential profile as the target peak.

[0017] The control unit may be configured to determine a plurality of graphite-related peaks among a plurality of peaks included in the differential profile when the negative electrode of the battery includes a plurality of active materials including graphite, and to determine the target peak among the plurality of graphite-related peaks.

[0018] The above control unit may be configured to determine the peak with the lowest corresponding voltage among the plurality of graphite-related peaks as the target peak.

[0019] 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.

[0020] An automobile according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0021] A battery diagnostic method according to another aspect of the present invention may include: a profile acquisition step of acquiring a differential profile representing a correspondence relationship between the voltage and differential capacity of a battery; a target peak determination step of determining a target peak in the differential profile; a differential capacity change rate calculation step of calculating a differential capacity change rate of the target peak based on preset peak data and the target peak; a comparison step of comparing the calculated differential capacity change rate with a preset threshold value; and a diagnostic step of diagnosing the state of the battery based on the comparison result.

[0022] A computer-readable recording medium according to another aspect of the present invention may store a program for executing a battery diagnostic method.

[0023] According to one aspect of the present invention, the battery diagnostic device has the advantage of being able to diagnose the condition of a battery in a non-destructive manner by considering the target peak of the differential profile.

[0024] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0025] The following drawings attached to this specification serve to further enhance understanding of the technical concept of the invention in conjunction with the detailed description of the invention set forth below; therefore, the invention should not be interpreted as being limited only to the matters described in such drawings.

[0026] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0027] FIG. 2 is a schematic diagram illustrating a battery profile according to one embodiment of the present invention.

[0028] FIG. 3 is a schematic diagram illustrating a differential profile according to one embodiment of the present invention.

[0029] FIG. 4 is a diagram schematically illustrating peak data according to one embodiment of the present invention.

[0030] FIG. 5 is a schematic diagram illustrating a target peak profile according to one embodiment of the present invention.

[0031] FIG. 6 is a schematic diagram illustrating a battery pack according to another embodiment of the present invention.

[0032] FIG. 7 is a schematic drawing illustrating an automobile according to another embodiment of the present invention.

[0033] FIG. 8 is a schematic diagram illustrating a battery diagnostic method according to another embodiment of the present invention.

[0034] Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0035] Therefore, 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; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0036] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0037] Terms including ordinal numbers, such as first, second, etc., are used for the purpose of distinguishing one of the various components from the rest, and are not used to limit the components by such terms.

[0038] Throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0039] Additionally, throughout the specification, when it is said that a part is "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other components in between.

[0040]

[0041] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0042] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0043] Referring to FIG. 1, the battery diagnostic device (100) may include a profile acquisition unit (110) and a control unit (120).

[0044] The profile acquisition unit (110) can be configured to acquire a differential profile (DP) that represents the corresponding relationship between the voltage and differential capacity of the battery.

[0045] Here, a battery refers to a single, independent cell that is physically separable and equipped with a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium-polymer battery may be considered a battery. Additionally, the battery may be of the cylindrical, prismatic, or pouch type. Furthermore, a battery may refer to a battery bank, battery module, or battery pack in which multiple cells are connected in series and / or parallel. For the sake of convenience of explanation, the term "battery" below is described as referring to a single, independent cell.

[0046] For example, a battery profile (BP) is a profile that represents the correspondence between voltage (V) and capacity (Q) when the battery's SOC is charged from a preset charge start SOC or 0% to a preset charge end SOC or 100%. As another example, a battery profile (BP) may also represent the correspondence between voltage (V) and capacity (Q) when the battery's SOC is discharged from a preset discharge start SOC or 100% to a preset discharge end SOC or 0%.

[0047] FIG. 2 is a schematic diagram illustrating a battery profile (BP) according to an embodiment of the present invention. In the embodiment of FIG. 2, the battery profile (BP) may be represented as an XY graph in which the X-axis is set as capacity (Q) and the Y-axis is set as voltage (V). However, it should be noted that the battery profile (BP) of FIG. 2 is represented in the form of a graph only for convenience of explanation, and there are no restrictions on the format in which the battery profile (BP) is represented as long as a corresponding relationship between the battery capacity and voltage is shown.

[0048] Furthermore, differentiating the battery profile (BP) with respect to voltage can generate a differential profile (DP) that represents the corresponding relationship between the differential capacity (dQ / dV) and the voltage (V). Here, the differential capacity (dQ / dV) refers to the value obtained by differentiating the capacity (Q) with respect to the voltage (V). In other words, the differential profile (DP) can be described as the profile obtained by differentiating the battery profile (BP) with respect to voltage.

[0049] FIG. 3 is a schematic diagram illustrating a differential profile (DP) according to an embodiment of the present invention. In the embodiment of FIG. 3, the differential profile (DP) can be represented as an XY graph in which the X-axis is set as voltage (V) and the Y-axis is set as differential capacity (dQ / dV). It should be noted that, similar to the battery profile (BP), there are no restrictions on the format in which the differential profile (DP) is represented as long as a corresponding relationship between the differential capacity and voltage of the battery is shown.

[0050] For example, there is no specific limit on the C-rate during charging or discharging for generating a battery profile (BP). However, preferably, to obtain a more accurate battery profile (BP) and differential profile (DP), 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 the battery at 0.05C.

[0051] For example, the profile acquisition unit (110) may be connected via wired and / or wireless means to enable communication with the outside. And, the profile acquisition unit (110) can acquire the differential profile (DP) by directly receiving the differential profile (DP) from the outside.

[0052] As another example, the profile acquisition unit (110) can directly receive a battery profile (BP) from the outside. Then, the profile acquisition unit (110) can acquire a differential profile (DP) by differentiating the battery profile (BP) with respect to voltage to generate a differential profile (DP).

[0053] As another example, the profile acquisition unit (110) can receive battery information regarding the voltage and capacity of the battery. Then, the profile acquisition unit (110) can generate a battery profile (BP) based on the received battery information and generate a differential profile (DP) based on the generated battery profile (BP). That is, the profile acquisition unit (110) can acquire the differential profile (DP) by directly generating the battery profile (BP) and the differential profile (DP) based on the battery information.

[0054] The profile acquisition unit (110) can be connected to communicate with the control unit (120). For example, the profile acquisition unit (110) can be connected to the control unit (120) via wired and / or wireless connections. The profile acquisition unit can transmit the acquired differential profile (DP) to the control unit (120).

[0055] The control unit (120) can be configured to determine the target peak (t) in the differential profile (DP).

[0056] Specifically, the differential profile (DP) may include multiple peaks. Here, a peak represents a point that is convex upward and has an instantaneous rate of change of differential capacitance with respect to voltage. That is, with respect to the peak, the instantaneous rate of change on the low voltage side is positive, and the instantaneous rate of change on the high voltage side is negative. For example, the peak may be a maximum point of the differential profile (DP). In the embodiment of FIG. 3, the differential profile (DP) may include a first peak (p1), a second peak (p2), a third peak (p3), and a fourth peak (p4).

[0057] The control unit (120) can be configured to determine the peak with the lowest corresponding voltage among a plurality of peaks included in the differential profile (DP) as the target peak (t).

[0058] Specifically, the explanation assumes a battery containing graphite as the negative electrode material. Among the multiple peaks, the peak with the lowest corresponding voltage is the peak associated with the initial lithium insertion reaction during the charging process or the later lithium desorption reaction during the discharging process. That is, in the case of the differential profile (DP) obtained during the charging process, the target peak (t) is the peak that appears as lithium ions are inserted into the graphite structure at the beginning of charging. Conversely, in the case of the differential profile (DP) obtained during the discharging process, the target peak (t) is the peak that appears as lithium ions are desorbed from the graphite structure at the end of discharging. That is, the target peak (t) that appears during the insertion and desorption of lithium ions in the graphite is a peak formed by a single phase transition or a change in lithium concentration, and can be referred to as the Ea (1) peak.

[0059] In the embodiment of FIG. 3, the control unit (120) can determine the first peak (p1) among the first to fourth peaks (p1, p2, p3 and p4) as the target peak (t).

[0060] The control unit (120) may be configured to calculate the differential capacity change rate of the target peak (t) based on preset peak data (PD) and the target peak (t).

[0061] Here, the peak data (PD) can be pre-set to represent the correspondence between the voltage and differential capacitance of the target peak (t) measured at the previous time point.

[0062] For example, assuming the present is the nth time point, the peak data (PD) can represent the correspondence between the voltage and differential capacitance of the target peak (t) determined at each of the 1st to the n-1th time points. That is, the peak data (PD) is data regarding multiple target peaks (t) measured in the past.

[0063] FIG. 4 is a schematic diagram illustrating peak data (PD) according to an embodiment of the present invention. In the embodiment of FIG. 4, the peak data (PD) may be represented as an XY graph in which the X-axis is set as voltage (V) and the Y-axis is set as differential capacitance (dQ / dV). However, it should be noted that there are no restrictions on the format for representing the peak data (PD) as long as a corresponding relationship between the differential capacitance and voltage of the target peak (t) is shown.

[0064] The control unit (120) may be configured to calculate the rate of change of the differential capacity with respect to the voltage of the target peak (t) as the rate of change of the differential capacity based on the voltage and differential capacity of the target peak (t) and the peak data (PD).

[0065] Specifically, the differential capacity change rate can be calculated based on data for a past target peak (t) included in the peak data (PD) and data for a current target peak (t) included in the differential profile (DP) acquired by the profile acquisition unit (110).

[0066] To calculate the differential capacity change rate, the control unit (120) can generate a target peak profile (TP) based on the determined target peak (t) and peak data (PD). For example, the control unit (120) can generate the target peak profile (TP) using polynomial fitting methods such as the least squares method (LSM), spline interpolation, trend line fitting, and polynomial regression.

[0067] And, the control unit (120) can calculate a differential capacitance change rate corresponding to the voltage of the current target peak (t) in the target peak profile (TP). For example, the control unit (120) can calculate a slope corresponding to the voltage of the current target peak (t) in the target peak profile (TP).

[0068] FIG. 5 is a schematic diagram illustrating a target peak profile (TP) according to an embodiment of the present invention. In the embodiment of FIG. 5, the target peak profile (TP) may be represented as an XY graph in which the X-axis is set as voltage (V) and the Y-axis is set as differential capacitance (dQ / dV). However, it should be noted that there are no restrictions on the format in which the target peak profile (TP) is represented as long as a correspondence relationship between differential capacitance and voltage is shown.

[0069] For example, the target peak profile (TP) of FIG. 5 is a profile approximated through polynomial fitting of the peak data (PD) of FIG. 4 and the data of the target peak (t) set by the control unit (120). The control unit (120) can calculate the differential capacity change rate corresponding to the target peak (t) determined from the differential profile in the target peak profile (TP).

[0070] The control unit (120) may be configured to compare the calculated differential capacity change rate with a preset threshold value.

[0071] Specifically, the control unit (120) can compare the magnitude between the differential capacity change rate and the threshold value. That is, the control unit (120) can determine whether the differential capacity change rate is greater than or less than the threshold value.

[0072] A threshold is a value that is experimentally or theoretically preset to distinguish the state of a battery from a normal or abnormal state. For example, the threshold can be preset to 0.

[0073] The control unit (120) can be configured to diagnose the state of the battery based on the comparison result.

[0074] Specifically, as the battery degrades, its resistance (internal resistance) increases, and based on the rate of increase in resistance, the battery's state can be classified as normal or abnormal. In particular, since the behavior of the target peak (t) is affected by the change in the negative resistance of the battery, the control unit (120) can diagnose the battery's state by considering the battery's state based on the result of comparing the differential capacity change rate and the threshold value.

[0075] Here, the steady state is a state in which the increase in resistance of the battery is not accelerated. Specifically, the steady state means a state in which resistance increases with the degradation of the battery, but the trend of the increase in resistance is maintained at a normal level. That is, if the degradation of the battery proceeds at a normal level, the state of the battery can be diagnosed as a steady state. For example, the control unit (120) may be configured to diagnose the state of the battery as a steady state when the differential capacity change rate is above a threshold value.

[0076] Conversely, an abnormal state is a state in which the increase in resistance of the battery is accelerated. Specifically, an abnormal state refers to a state in which the resistance increases rapidly as the trend of increasing resistance due to battery degradation exceeds a normal level. That is, if the degradation of the battery is abnormally accelerated, the state of the battery can be diagnosed as an abnormal state. For example, the control unit (120) may be configured to diagnose the state of the battery as an abnormal state when the differential capacity change rate is below a threshold value.

[0077] In the embodiment of FIG. 5, it is assumed that the threshold value is preset to 0.

[0078] For example, when the voltage of the target peak (t) is between V1 and V2, the differential capacity change rate is greater than 0. Therefore, since the differential capacity change rate is greater than the threshold value, the control unit can diagnose the battery's condition as normal.

[0079] As another example, when the voltage of the target peak (t) exceeds V2, the differential capacity change rate is less than 0. Therefore, since the differential capacity change rate is below the threshold value, the control unit can diagnose the battery condition as abnormal.

[0080] A battery diagnostic device (100) according to one embodiment of the present invention has the advantage of being able to diagnose the condition of a battery in a non-destructive manner by considering the target peak (t) of the differential profile (DP).

[0081] In particular, according to the battery diagnostic device (100), the rate of degradation of the battery can be diagnosed by considering the increasing trend of the internal resistance of the battery. Therefore, by considering the diagnostic results of the battery diagnostic device (100), battery management can be performed to extend the lifespan of the battery and improve the safety of the battery.

[0082] For example, when a battery management system (BMS) obtains a diagnosis result from a battery diagnostic device (100), the BMS can determine whether the battery is accelerating degradation based on the diagnosis result. Then, the BMS can effectively manage the battery by appropriately setting the battery usage conditions (e.g., upper voltage limit, lower voltage limit, upper temperature limit, etc.) corresponding to the diagnosis result and appropriately controlling the charging and discharging of the battery. That is, since the battery diagnostic device (100) can provide information on whether the battery is accelerating degradation, it has the advantage of helping to accurately monitor the state of the battery.

[0083]

[0084] Meanwhile, the control unit (120) provided in the battery diagnostic device (100) may optionally include a processor, an ASIC (application-specific integrated circuit), 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. Additionally, when the control logic is implemented in software, the control unit (120) may be implemented as a set of program modules. At this time, the program modules may be stored in memory and executed by the control unit (120). The memory may be located inside or outside the control unit (120) and may be connected to the control unit (120) by various well-known means.

[0085] Additionally, the battery diagnostic device (100) may further include a storage unit (130). The storage unit (130) may store data or programs necessary for each component of the battery diagnostic device (100) to perform operations and functions, or data generated during the process of performing operations and functions. The storage unit (130) is not subject to any special restrictions on its type as long as it is a known information storage means capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. Additionally, the storage unit (130) may store program codes that define processes executable by each component of the battery diagnostic device (100).

[0086] For example, the storage unit (130) can store a differential profile (DP) and peak data (PD). The control unit (120) can access the storage unit (130) to obtain the peak data (PD) and diagnose the state of the battery based on the peak data (PD). Then, the control unit (120) can update the peak data (PD) by storing information about the target peak (t) at the current time point in the peak data (PD).

[0087]

[0088] The control unit (120) may be configured to compare the differential capacity change rate with a second threshold value set to a value less than the threshold value.

[0089] Specifically, the control unit (120) can diagnose the state of the battery in more detail when the differential capacity change rate is below a threshold value. To do this, the control unit (120) can compare the differential capacity change rate with a second threshold value that is preset to a value below the threshold value.

[0090] The control unit (120) may be configured to diagnose the state of the battery as a first abnormal state in which degradation is accelerated or a second abnormal state in which lithium is precipitated, based on the comparison result.

[0091] Here, the first abnormal state refers to a state in which the degradation of the battery is accelerated, but the battery can be used by adjusting only the usage conditions for the battery. That is, the first abnormal state is a state in which the degradation of the battery is accelerated, but the battery can be continuously used through temperature and / or C-rate control. For example, the control unit (120) may be configured to diagnose the state of the battery as the first abnormal state when the differential capacity change rate is below a threshold value and above a second threshold value.

[0092] Next, the second abnormal state refers to a state in which the use of the battery is not recommended. That is, the second abnormal state may be a state in which lithium metal is precipitated in the battery, making the use of the battery inappropriate. For example, the control unit (120) may be configured to diagnose the state of the battery as the second abnormal state when the differential capacity change rate is less than the second threshold value or when it is impossible to calculate the differential capacity change rate.

[0093] In the embodiment of FIG. 5, it is assumed that the threshold value is 0 and the second threshold value is preset as the differential capacitance change rate corresponding to the V3 voltage.

[0094] For example, if the voltage of the target peak (t) falls between V1 and V2, the differential capacity change rate is above the threshold value. Therefore, the control unit can diagnose the battery state as normal.

[0095] As another example, when the voltage of the target peak (t) falls within the range of greater than V2 and less than V3, the differential capacity change rate is below the threshold value but above the second threshold value. Therefore, the control unit can diagnose the battery state as the first abnormal state.

[0096] As another example, when the voltage of the target peak (t) exceeds V3, the differential capacity change rate is less than the second threshold. Therefore, the control unit can diagnose the battery state as a second abnormal state.

[0097] The battery diagnostic device (100) can diagnose the abnormal state of the battery by further subdividing it into a first abnormal state and a second abnormal state. That is, according to the battery diagnostic device (100), the first abnormal state, in which degradation is simply accelerated, and the second abnormal state, which has a high risk of fire, explosion, etc., can be further distinguished. Therefore, the battery diagnostic device (100) has the advantage of being able to diagnose the current state of the battery more specifically.

[0098]

[0099] The control unit (120) may be configured to determine a plurality of graphite-related peaks among a plurality of peaks included in the differential profile (DP) when the negative electrode of the battery includes a plurality of active materials including graphite.

[0100] Specifically, the control unit (120) can determine a graphite-related peak among a plurality of peaks included in the differential profile (DP) by using peak information for the negative electrode active material. For example, the peak information may be information about the voltage range in which the peak of each negative electrode active material appears.

[0101] For example, the control unit (120) can obtain information regarding the voltage range in which a peak appears for each cathode material from a database in which electrochemical reaction characteristics for each cathode material are stored. Then, based on the obtained information, the control unit (120) can determine the graphite-related peak among a plurality of peaks included in the differential profile (DP).

[0102] It is assumed that the battery contains a negative electrode active material mixed with graphite and silicon (Six). The differential profile (DP) of the battery may include a graphite-related peak and a silicon-related peak. Here, the silicon-related peak is a peak that appears due to the reaction between silicon and lithium, and appears at a lower voltage side than the voltage corresponding to the graphite-related peak. Therefore, the control unit (120) can determine the peak with the lowest corresponding voltage as the silicon-related peak and determine the remaining peaks as the graphite-related peaks.

[0103] The control unit (120) may be configured to determine a target peak (t) among a plurality of graphite-related peaks.

[0104] Specifically, the control unit (120) may be configured to determine the peak with the lowest corresponding voltage among a plurality of graphite-related peaks as the target peak (t). Here, the peak with the lowest corresponding voltage among the plurality of graphite-related peaks corresponds to peak Ea (1).

[0105] More specifically, the Ea (1) peak is a peak that reflects 1) the formation and re-formation of the SEI (solid electrolyte interphase) and 2) the interfacial reaction occurring during the insertion and extraction of lithium. Therefore, the battery diagnostic device (100) has the advantage of being able to diagnose the state of the battery by comprehensively considering the interfacial reactivity of the battery and the stability of the SEI, etc., even for a battery containing multiple active materials, based on the behavior of the Ea (1) peak.

[0106]

[0107] The battery diagnostic device (100) according to the present invention may be applied to a Battery Management System (BMS). That is, the BMS according to the present invention may include the battery diagnostic device (100) described above. In this configuration, at least some of the components of the battery diagnostic device (100) may be implemented by supplementing or adding the functions of the components included in a conventional BMS. For example, the profile acquisition unit (110), control unit (120), and storage unit (130) of the battery diagnostic device (100) may be implemented as components of the BMS.

[0108] In addition, the battery diagnostic device (100) according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the battery diagnostic device (100) described above and one or more battery cells. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0109] FIG. 6 is a schematic diagram illustrating a battery pack according to another embodiment of the present invention.

[0110] 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).

[0111] The measuring unit (12) can be connected to the first sensing line (SL1), the second sensing line (SL2), and the third sensing line (SL3). Specifically, the measuring unit (12) can be connected to the positive terminal of the battery (11) through the first sensing line (SL1) and to the 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).

[0112] Additionally, the measuring unit (12) can be connected to a current measuring unit (A) through a third sensing line (SL3). For example, the current measuring unit (A) may 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 calculate the charging amount by measuring the charging current of the battery (11) through the third sensing line (SL3). Furthermore, the measuring unit (12) can calculate the discharging amount by measuring the discharging current of the battery (11) through the third sensing line (SL3).

[0113] For example, the profile acquisition unit (110) can receive battery information regarding the voltage and current of the battery from the measurement unit (12). Then, the profile acquisition unit (110) can generate a battery profile (BP) and a differential profile (DP) based on the battery information.

[0114] As another example, the profile acquisition unit (110) can receive a battery profile (BP) from the measurement unit (12). Then, the profile acquisition unit (110) can generate a differential profile (DP) based on the battery profile (BP).

[0115] As another example, the profile acquisition unit (110) can receive a differential profile (DP) from the measurement unit (12).

[0116] An external device may be connected to the positive terminal (P+) and the negative terminal (P-) of the battery pack (10). For example, the external device may be a charging device or a load. Also, 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.

[0117]

[0118] FIG. 7 is a schematic drawing illustrating a vehicle (700) according to another embodiment of the present invention.

[0119] 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). The battery pack (710) can drive the vehicle (700) by supplying power to a motor through an inverter provided in the vehicle (700). Here, the battery pack (710) may include a battery diagnostic device (100). That is, the vehicle (700) may include a battery diagnostic device (100). In this case, the battery diagnostic device (100) may be an on-board device included in the vehicle (700).

[0120]

[0121] FIG. 8 is a schematic diagram illustrating a battery diagnostic method according to another embodiment of the present invention.

[0122] Referring to FIG. 8, the battery diagnostic method may include a profile acquisition step (S100), a target peak determination step (S200), a differential capacity change rate calculation step (S300), a comparison step (S400), and a diagnostic step (S500).

[0123] Preferably, each step of the battery diagnostic method can be performed by a battery diagnostic device (100). For convenience of explanation, details that overlap with previously described content will be omitted or briefly explained below.

[0124] The profile acquisition step (S100) is a step of acquiring a differential profile (DP) representing the corresponding relationship between the voltage and differential capacity of the battery, and can be performed by the profile acquisition unit (110).

[0125] For example, the profile acquisition unit (110) may be connected via wired and / or wireless means to enable communication with the outside. And, the profile acquisition unit (110) can acquire the differential profile (DP) by directly receiving the differential profile (DP) from the outside.

[0126] As another example, the profile acquisition unit (110) can directly receive a battery profile (BP) from the outside. Then, the profile acquisition unit (110) can acquire a differential profile (DP) by differentiating the battery profile (BP) with respect to voltage to generate a differential profile (DP).

[0127] As another example, the profile acquisition unit (110) can receive battery information regarding the voltage and capacity of the battery. Then, the profile acquisition unit (110) can generate a battery profile (BP) based on the received battery information and generate a differential profile (DP) based on the generated battery profile (BP). That is, the profile acquisition unit (110) can acquire the differential profile (DP) by directly generating the battery profile (BP) and the differential profile (DP) based on the battery information.

[0128] The target peak determination step (S200) is a step of determining the target peak (t) in the differential profile (DP), and can be performed by the control unit (120).

[0129] For example, the control unit (120) may be configured to determine the peak with the lowest corresponding voltage among a plurality of peaks included in the differential profile (DP) as the target peak (t).

[0130] As another example, the control unit (120) may be configured to determine a plurality of graphite-related peaks among a plurality of peaks included in the differential profile (DP) when the negative electrode of the battery includes a plurality of active materials including graphite. And, the control unit (120) may be configured to determine the peak with the lowest corresponding voltage among the plurality of graphite-related peaks as the target peak (t).

[0131] The differential capacity change rate calculation step (S300) is a step of calculating the differential capacity change rate of a target peak (t) based on preset peak data (PD) and a target peak (t), and can be performed by a control unit (120).

[0132] For example, the control unit (120) may be configured to calculate the rate of change of the differential capacity with respect to the voltage of the target peak (t) as the rate of change of the differential capacity based on the voltage and differential capacity of the target peak (t) and the peak data (PD).

[0133] The comparison step (S400) is a step of comparing the calculated differential capacity change rate with a preset threshold value, and can be performed by the control unit (120).

[0134] For example, the control unit (120) can compare the magnitude between the differential capacity change rate and the threshold value. That is, the control unit (120) can determine whether the differential capacity change rate is greater than or less than the threshold value.

[0135] The diagnosis step (S500) is a step of diagnosing the state of the battery based on the comparison result, and can be performed by the control unit (120).

[0136] For example, the control unit (120) may be configured to diagnose the state of the battery as normal when the differential capacity change rate is greater than or equal to a threshold value. The control unit (120) may be configured to diagnose the state of the battery as abnormal when the differential capacity change rate is less than a threshold value.

[0137] As another example, the control unit (120) may be configured to diagnose the state of the battery as a first abnormal state when the differential capacity change rate is below a threshold value and above a second threshold value. Conversely, the control unit (120) may be configured to diagnose the state of the battery as a second abnormal state when the differential capacity change rate is below a second threshold value or when it is impossible to calculate the differential capacity change rate.

[0138]

[0139] The embodiments of the present invention described above are not limited to implementation 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 such a program is recorded. Such implementation can be easily achieved by a person skilled in the art to which the present invention pertains, based on the description of the embodiments described above.

[0140] Another embodiment of the present invention may provide a computer-readable recording medium having a program recorded thereon for executing the various embodiments described above on a computer.

[0141] A program may be implemented as hardware components, software components, and / or a combination of hardware and software components. A program may be executed by any system capable of executing computer-readable instructions.

[0142] Software may include computer programs, code, instructions, or a combination thereof, and may configure a processing unit to operate as desired or command the processing unit independently or collectively.

[0143] Software can be implemented as a computer program containing instructions stored on a computer-readable storage medium. Examples of computer-readable storage media include magnetic storage media (e.g., ROM (read-only memory), RAM (random-access memory), floppy disks, hard disks, etc.) and optical reading media (e.g., CD-ROMs, DVDs (Digital Versatile Discs)). Computer-readable storage media can be distributed across networked computer systems, allowing computer-readable code to be stored and executed in a distributed manner. The storage medium is readable by a computer, stored in memory, and can be executed by a processor.

[0144] Computer-readable recording media may be provided in the form of non-transitory recording media. Here, 'non-transitory storage media' simply means that it is a tangible device and does not contain a signal (e.g., electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily. For example, 'non-transitory storage media' may include a buffer in which data is stored temporarily.

[0145] In addition, the program may be provided as part of a computer program product. Computer program products may be traded between a seller and a buyer as goods.

[0146] A computer program product may include a software program or a computer-readable recording medium on which the software program is stored. For example, a computer program product may include a product in the form of a software program that is distributed electronically through a manufacturer of an electronic device or an electronic market (e.g., a downloadable application). For electronic distribution, at least a portion of the software program may be stored on a recording medium or temporarily created. In this case, the recording medium may be a server of the manufacturer of the electronic device, a server of the electronic market, or a recording medium of a relay server that temporarily stores the software program.

[0147] Although the present invention has been described above by 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 spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0148] Furthermore, since the present invention described above allows for various substitutions, modifications, and changes within the scope of the technical concept of the present invention to those skilled in the art without departing from the technical spirit of the present invention, it is not limited by the aforementioned embodiments and attached drawings, but rather all or part of each embodiment may be selectively combined to allow for various modifications.

[0149] (Explanation of symbols)

[0150] 10: Battery pack

[0151] 11: Battery

[0152] 12: Measurement section

[0153] 100: Battery Diagnostic Device

[0154] 110: Profile Acquisition Section

[0155] 120: Control unit

[0156] 130: Storage section

[0157] 700: Car

[0158] 710: Battery pack

Claims

1. A profile acquisition unit configured to acquire a differential profile representing the corresponding relationship between the voltage and differential capacity of a battery; and A battery diagnostic device comprising a control unit configured to determine a target peak in the above differential profile, calculate a differential capacity change rate of the target peak based on preset peak data and the target peak, compare the calculated differential capacity change rate with a preset threshold value, and diagnose the state of the battery based on the comparison result.

2. In Paragraph 1, The above peak data is, A battery diagnostic device pre-configured to indicate the correspondence between the voltage of the target peak and the differential capacity measured at a previous point in time.

3. In Paragraph 1, The above control unit is, A battery diagnostic device configured to calculate the rate of change of the differential capacity with respect to the voltage of the target peak as the rate of change of differential capacity, based on the voltage of the target peak, the differential capacity, and the peak data.

4. In Paragraph 1, The above control unit is, A battery diagnostic device configured to diagnose the state of the battery as normal when the differential capacity change rate is greater than or equal to the threshold value.

5. In Paragraph 1, The above control unit is, A battery diagnostic device configured to diagnose the state of the battery as abnormal when the differential capacity change rate is below the threshold value.

6. In Paragraph 5, The above control unit is, A battery diagnostic device configured to compare the differential capacity change rate with a second threshold value set below the threshold value, and based on the comparison result, diagnose the state of the battery as a first abnormal state in which degradation is accelerated or a second abnormal state in which lithium is precipitated.

7. In Paragraph 6, The above control unit is, If the differential capacity change rate is less than the threshold value and greater than or equal to the second threshold value, the state of the battery is diagnosed as the first abnormal state, and A battery diagnostic device configured to diagnose the state of the battery as the second abnormal state when the differential capacity change rate is less than the second threshold value or when it is impossible to calculate the differential capacity change rate.

8. In Paragraph 1, The above control unit is, A battery diagnostic device configured to determine the peak with the lowest corresponding voltage among a plurality of peaks included in the above differential profile as the target peak.

9. In Paragraph 1, The above control unit is, A battery diagnostic device configured to determine a plurality of graphite-related peaks among a plurality of peaks included in the differential profile when the negative electrode of the battery includes a plurality of active materials including graphite, and to determine the target peak among the plurality of graphite-related peaks.

10. In Paragraph 9, The above control unit is, A battery diagnostic device configured to determine the peak with the lowest corresponding voltage among the plurality of graphite-related peaks as the target peak.

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

12. An automobile comprising a battery diagnostic device according to any one of paragraphs 1 through 10.

13. A profile acquisition step for acquiring a differential profile representing the correspondence relationship between the voltage and differential capacity of a battery; A target peak determination step for determining a target peak in the above differential profile; A step for calculating the differential capacity change rate based on preset peak data and the target peak to calculate the differential capacity change rate of the target peak; A comparison step for comparing the calculated differential capacity change rate with a preset threshold; and A battery diagnostic method comprising a diagnostic step for diagnosing the condition of the battery based on a comparison result.

14. A computer-readable recording medium storing a program for executing the battery diagnostic method according to paragraph 13.

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