Battery condition diagnostic device and method

Abstract

According to an embodiment of the present invention, a battery state diagnosis device includes: a profile acquisition unit configured to acquire a plurality of differential profiles indicating a correspondence relationship between a differential capacity indicating a capacity change rate of the battery with respect to the voltage of the battery and the voltage; a peak determination unit configured to determine a target peak located in a predetermined voltage range from each of the plurality of differential profiles; and a state diagnosis unit configured to compare voltages of the plurality of target peaks determined by the peak determination unit with voltages of reference peaks preset to correspond to each of the plurality of target peaks, and to diagnose a state of the battery based on a voltage comparison result.

Description

[Technical field]

[0001] The present invention relates to a battery condition diagnosis device and method, and more particularly to a battery condition diagnosis device and method capable of diagnosing the state of a battery.

[0002] This application claims priority to Korean Patent Application No. 10-2021-0022771, filed on February 19, 2021, and all contents disclosed in the specification and drawings of the relevant application are incorporated herein by reference. [Background technology]

[0003] Recently, as the demand for portable electronic products such as notebook PCs, video cameras, and mobile phones has increased sharply and the development of electric vehicles, energy storage batteries, robots, satellites, etc. has progressed in earnest, research into high-performance batteries that can be repeatedly charged and discharged is progressing actively.

[0004] Currently, commercial batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Of these, lithium batteries are in the spotlight due to their advantages over nickel-based batteries, such as almost no memory effect, freedom to charge and discharge, a very low self-discharge rate, and high energy density.

[0005] Typically, such batteries may degrade as they are repeatedly charged and discharged. For example, the electrolyte may oxidize or the crystal structure may be destroyed on the positive electrode side of the battery, causing the battery to degrade. On the negative electrode side of the battery, metallic lithium may be precipitated, causing the battery to degrade. Therefore, there is a need to develop a technology that can non-destructively diagnose the state of a battery based on the voltage and capacity indicators of the battery. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above problems, and has an object to provide a battery condition diagnosis device and method capable of non-destructively diagnosing the state of a battery based on the voltage and capacity of the battery.

[0007] Other objects and advantages of the present invention will become apparent from the following description and the embodiments of the present invention, and can be realized by the means and combinations thereof as claimed in the appended claims. [Means for solving the problem]

[0008] According to one aspect of the present invention, a battery status diagnosis device may include: a profile acquisition unit configured to acquire a plurality of differential profiles indicating a correspondence relationship between a differential capacity indicating a capacity change rate of the battery with respect to a voltage of the battery and the voltage; a peak determination unit configured to determine a target peak located in a predetermined voltage range from each of the plurality of differential profiles; and a status diagnosis unit configured to compare voltages of the plurality of target peaks determined by the peak determination unit with voltages of reference peaks preset to correspond to each of the plurality of target peaks, and to diagnose a status of the battery based on a voltage comparison result.

[0009] The state diagnosis unit may be configured to diagnose the state of the battery as an abnormal state when a voltage of at least one of the plurality of target peaks is lower than a voltage of a corresponding reference peak.

[0010] The condition diagnosis unit may be configured to set a reference peak from among the plurality of target peaks, and calculate a voltage change rate for each of the plurality of targets based on the voltage of the set reference peak.

[0011] The condition diagnosis unit may be configured to calculate a reference rate of change for each of the plurality of reference peaks based on a voltage of a reference peak corresponding to the set reference peak among a plurality of reference peaks corresponding to the plurality of target peaks.

[0012] The condition diagnosis unit may be configured to compare corresponding voltage change rates with reference change rates based on a correspondence relationship between the multiple target peaks and the multiple reference peaks, and to diagnose the condition of the battery based on a change rate comparison result and the voltage comparison result.

[0013] The condition diagnosis unit may be configured to diagnose the condition of the battery as abnormal when the voltage and the voltage change rate of at least one of the plurality of target peaks are less than the voltage and the reference change rate of a corresponding reference peak.

[0014] The profile acquirer may be configured to acquire a differential profile for the battery at a number of different time points.

[0015] The multiple time points may be multiple cycle time points or multiple degradation time points for the battery.

[0016] Furthermore, a battery pack according to another aspect of the present invention may include a battery condition diagnosis device according to the one aspect of the present invention.

[0017] According to yet another aspect of the present invention, a battery status diagnosis method may include: a profile acquiring step of acquiring a plurality of differential profiles indicating a correspondence relationship between a differential capacity indicating a capacity change rate of the battery with respect to a voltage of the battery and the voltage; a peak determining step of determining a target peak located in a predetermined voltage range from each of the plurality of differential profiles; a comparing step of comparing voltages of the plurality of target peaks determined in the peak determining step with voltages of reference peaks preset to correspond to each of the plurality of target peaks; and a status diagnosing step of diagnosing a status of the battery based on a voltage comparison result in the comparing step. Effect of the Invention

[0018] According to one aspect of the present invention, it is possible to diagnose the state of a battery based on a differential profile of the battery, and in particular, it is possible to diagnose a battery that may experience a sudden drop in state of health (SOH) based on a target peak voltage and / or a voltage change rate included in the differential profile.

[0019] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0020] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic diagram of a battery state diagnosis device according to an embodiment of the present invention; [Diagram 2] 2 is a diagram illustrating the SOH of a first battery and a second battery according to an embodiment of the present invention; [Diagram 3] FIG. 4 is a diagram showing differential profiles for a first battery and a second battery according to an embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing differential profiles for a first battery and a second battery according to an embodiment of the present invention. [Diagram 5] FIG. 4 is a diagram showing differential profiles for a first battery and a second battery according to an embodiment of the present invention. [Figure 6] FIG. 4 is a diagram showing differential profiles for a first battery and a second battery according to an embodiment of the present invention. [Figure 7] FIG. 2 is a schematic diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 8]13 is a diagram illustrating a battery state diagnosis method according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best describe the invention.

[0023] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0024] Furthermore, if a detailed description of known functions or configurations related to the present invention is deemed to obscure the gist of the present invention, the description will be omitted.

[0025] Terms including ordinal numbers such as "first", "second", etc. are used for the purpose of distinguishing one of various components from the rest, and are not intended to limit the components.

[0026] In addition, throughout the specification, when a part "includes" a certain component, this does not mean excluding other components, but means that it may further include other components, unless specifically stated to the contrary.

[0027] Furthermore, throughout this specification, when a part is said to be "connected" to another part, this includes not only when it is "directly connected" to another part, but also when it is "indirectly connected" through another element in between.

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0029] FIG. 1 is a diagram illustrating a battery condition diagnosis device 100 according to an embodiment of the present invention.

[0030] Referring to FIG. 1, a battery status diagnosis device 100 according to an embodiment of the present invention may include a profile acquisition unit 110, a peak determination unit 120, and a status diagnosis unit .

[0031] Here, a battery refers to a single independent cell that has a negative terminal and a positive terminal and can be physically separated. As an example, a lithium ion battery or a lithium polymer battery can be considered as a battery.

[0032] The profile acquisition unit 110 may be configured to acquire a plurality of differential profiles indicating a correspondence relationship between a differential capacity indicating a capacity change rate of the battery with respect to the voltage of the battery and the voltage.

[0033] Here, the differential capacity is a value indicating the rate of change in the capacity of the battery relative to the voltage of the battery, and can be expressed as dQ / dV.

[0034] For example, the profile acquirer 110 may acquire a plurality of differential profiles indicating a correspondence relationship between a differential capacity and a voltage of the battery. In another example, the profile acquirer 110 may acquire a plurality of battery profiles indicating a correspondence relationship between a voltage and a capacity of the battery, and may acquire the differential profile by calculating the differential capacity of the battery based on each of the acquired plurality of battery profiles.

[0035] Preferably, the profile acquirer 110 may be configured to acquire a differential profile for the battery at a number of different time points.

[0036] For example, the multiple time points may be multiple cycle time points or multiple degradation time points for the battery. That is, the profile acquirer 110 may acquire differential profiles for multiple SOH (State of health) of the battery. Here, SOH is an index indicating the health state of the battery, and the SOH of a beginning of life (BOL) battery may be 1. And, the more the battery degrades, the lower the SOH of the battery may be.

[0037] FIG. 2 is a diagram illustrating the SOH of a first battery B1 and a second battery B2 according to an embodiment of the present invention.

[0038] 2, the first battery B1 and the second battery B2 may degrade and have a reduced SOH as the charge and discharge cycles are repeated, i.e., the first battery B1 and the second battery B2 may degrade as the charge and discharge cycles are repeated.

[0039] However, the first battery B1 may have a gradual decrease in SOH as the number of cycles increases, whereas the second battery B2 may have a rapid decrease in SOH as the number of cycles increases. That is, the first battery B1 may be a reference battery that does not experience a sudden drop in SOH. The second battery B2 may be an abnormal battery that is the subject of a status diagnosis and experiences a sudden drop in SOH around 150 cycles.

[0040] 2, the profile acquirer 110 may acquire differential profiles at times when the SOH of the second battery B2 is 0.99, 0.97, 0.95, and 0.92. That is, the profile acquirer 110 may acquire differential profiles for the second battery B2 at multiple times according to the SOH of the second battery B2.

[0041] Preferably, a differential profile for the first battery B1, which is a reference battery, is stored in advance in the storage unit 140, and the profile acquisition unit 110 may acquire a differential profile for the second battery B2, which is a target of the state diagnosis.

[0042] 3 to 6 are diagrams illustrating differential profiles for a first battery B1 and a second battery B2 according to an embodiment of the present invention. Specifically, Fig. 3 to Fig. 6 are diagrams illustrating differential profiles at first to fourth time points according to SOH of the first battery B1 and the second battery B2.

[0043] FIG. 3 is a diagram showing a first differential profile RP1 for the first battery B1 and a first differential profile DP1 for the second battery B2 at a first time point when the SOH of the first battery B1 and the second battery B2 is 0.99.

[0044] FIG. 4 is a diagram showing a second differential profile RP2 for the first battery B1 and a second differential profile DP2 for the second battery B2 at a second time point when the SOH of the first battery B1 and the second battery B2 is 0.97.

[0045] FIG. 5 is a diagram showing a third differential profile RP3 for the first battery B1 and a third differential profile DP3 for the second battery B2 at a third time point when the SOH of the first battery B1 and the second battery B2 is 0.95.

[0046] FIG. 4 is a diagram showing a fourth differential profile RP4 for the first battery B1 and a fourth differential profile DP4 for the second battery B2 at a fourth time point when the SOH of the first battery B1 and the second battery B2 is 0.92.

[0047] That is, referring to the embodiment of FIG. 2, the differential profile of the first battery B1 and the differential profile of the second battery B2 may be obtained when the SOH of the first battery B1 and the second battery B2 are obtained at the same time.

[0048] The peak determining unit 120 may be configured to determine a target peak located in a predetermined voltage interval from each of the plurality of differential profiles.

[0049] Specifically, the predetermined voltage range may be a part located in the center of a voltage range set to be operable for the battery. For example, assume that the entire voltage range set to be operable for the battery is 3.3V to 4.2V. In this case, the predetermined voltage range may be a range from 3.6V to 3.9V in the entire voltage range.

[0050] For example, the peak determining section 120 may determine, among the points where the differential capacitance is zero in a predetermined voltage section, the point where the differential capacitance is maximum as the peak of the differential profile.

[0051] 3, the peak determiner 120 may determine a first target peak TP1 from the first differential profile DP1 for the second battery B2. A voltage corresponding to the first target peak TP1 may be Vtp1. Meanwhile, the first differential profile RP1 of the first battery B1 may include a first reference peak P1 corresponding to the first target peak TP1. And, a voltage corresponding to the first reference peak P1 may be Vp1.

[0052] 4, the peak determiner 120 may determine a second target peak TP2 from the second differential profile DP2 for the second battery B2. The voltage corresponding to the second target peak TP2 may be Vtp2. Meanwhile, the second differential profile RP2 of the first battery B1 may include a second reference peak P2 corresponding to the second target peak TP2. And, the voltage corresponding to the second reference peak P2 may be Vp2.

[0053] 5, the peak determiner 120 may determine a third target peak TP3 from the third differential profile DP3 for the second battery B2. A voltage corresponding to the third target peak TP3 may be Vtp3. Meanwhile, the third differential profile RP3 for the first battery B1 may include a third reference peak P3 corresponding to the third target peak TP3. And, a voltage corresponding to the third reference peak P3 may be Vp3.

[0054] 6, the peak determiner 120 may determine a fourth target peak TP4 from the fourth differential profile DP4 for the second battery B2. A voltage corresponding to the fourth target peak TP4 may be Vtp4. Meanwhile, the fourth differential profile RP4 of the first battery B1 may include a fourth reference peak P4 corresponding to the fourth target peak TP4. And, a voltage corresponding to the fourth reference peak P4 may be Vp4.

[0055] The condition diagnosis unit 130 may be configured to compare the voltages of the target peaks determined by the peak determination unit 120 with the voltages of reference peaks that are preset to correspond to the target peaks, respectively.

[0056] Specifically, the condition diagnosis section 130 may directly compare the magnitude of the voltages of the multiple target peaks with the voltages of the corresponding reference peaks.

[0057] For example, the condition diagnosis unit 130 may compare the voltage magnitudes of the first target peak TP1 and the first reference peak P1, and the voltage magnitudes of the second target peak TP2 and the second reference peak P2, and may compare the voltage magnitudes of the third target peak TP3 and the third reference peak P3, and may compare the voltage magnitudes of the fourth target peak TP4 and the fourth reference peak P4.

[0058] The status diagnosis unit 130 may be configured to diagnose the status of the battery based on the voltage comparison result.

[0059] Specifically, the state diagnosis unit 130 may be configured to diagnose the state of the battery as an abnormal state when the voltage of at least one of the plurality of target peaks is lower than the voltage of the corresponding reference peak.

[0060] As described above, an abnormal state refers to a state in which the SOH of a battery decreases rapidly as the battery deteriorates. For example, when a battery is diagnosed as being in an abnormal state, it means that the SOH of the battery may drop rapidly.

[0061] For example, in the embodiment of Figure 3, the voltage Vtp1 of the first target peak TP1 may be less than the voltage Vp1 of the first reference peak P1. Similarly, in the embodiment of Figure 4, the voltage Vtp2 of the second target peak TP2 may be less than the voltage Vp2 of the second reference peak P2. Also, in the embodiment of Figure 5, the voltage Vtp3 of the third target peak TP3 may be less than the voltage Vp3 of the third reference peak P3. Also, in the embodiment of Figure 6, the voltage Vtp4 of the fourth target peak TP4 may be less than the voltage Vp4 of the fourth reference peak P4.

[0062] Therefore, the condition diagnosis unit 130 may diagnose the condition of the second battery B2 as an abnormal condition. That is, the condition diagnosis unit 130 may diagnose the condition of the second battery B2 as an abnormal condition in which there is a possibility of a sudden drop in SOH because the target peak voltage corresponding to the second battery B2 is lower than the reference peak voltage corresponding to the first battery B1.

[0063] That is, the battery status diagnosis device 100 according to an embodiment of the present invention has an advantage of being able to quickly diagnose the battery status by comparing a voltage corresponding to a target peak of the battery with a voltage corresponding to a reference peak of the reference battery. In particular, the battery status diagnosis device 100 has an advantage of being able to quickly diagnose a battery that is at risk of a sudden drop based on the result of comparing the reference peak voltage with the target peak voltage.

[0064] Meanwhile, the battery status diagnosis device 100 may selectively include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the art, to execute various control logics performed in the present invention. Also, when the control logic is embodied in software, the battery status diagnosis device 100 may be embodied as a collection of program modules.

[0065] The battery state diagnosis device 100 may further include a storage unit 140. The storage unit 140 may store data and programs required for each component of the battery state diagnosis device 100 to operate and function, or data generated in the process of operating and functioning. The type of the storage unit 140 is not particularly limited as long as it is a known information storage means capable of recording, erasing, updating and reading data. Examples of the information storage means include RAM, flash memory, ROM, EEPROM, and registers. The storage unit 140 may also store program code that defines processes that can be executed by each component of the battery state diagnosis device 100.

[0066] For example, the storage unit 140 may store a plurality of differential profiles for the battery. In this case, the profile acquiring unit 110 may access the storage unit 140 to acquire the plurality of differential profiles for the battery.

[0067] In another example, the storage unit 140 may store a plurality of battery profiles for the battery. In this case, the profile acquirer 110 may access the storage unit 140 to acquire a plurality of battery profiles for the battery, and acquire a plurality of differential profiles based on the acquired plurality of battery profiles.

[0068] In another embodiment, the condition diagnosis unit 130 may be configured to set a reference peak among the plurality of target peaks.

[0069] For example, the status diagnosis unit 130 may set a target peak having the lowest degree of degradation of a corresponding battery as a reference peak among the plurality of target peaks. Specifically, the status diagnosis unit 130 may set a target peak having the lowest voltage as a reference peak.

[0070] For example, referring to Figures 3 to 6, the condition diagnosis unit 130 may set the first target peak TP1, which has the lowest corresponding voltage among the first target peak TP1, the second target peak TP2, the third target peak TP3, and the fourth target peak TP4, as the reference peak.

[0071] The condition diagnosis unit 130 may be configured to calculate a voltage change rate for each of the multiple targets based on a set reference peak voltage.

[0072] For example, the condition diagnosis unit 130 may calculate the voltage change rate for each of the second target peak TP2, the third target peak TP3, and the fourth target peak TP4 based on the voltage of the reference peak TP1. Here, it is assumed that the voltage change rate for the first target peak TP1 is 0 and can be omitted. Specifically, the condition diagnosis unit 130 may calculate the voltage change rate using the formula "(voltage of the nth target peak-voltage of the reference peak)÷voltage of the reference peak" or "voltage of the nth target peak-voltage of the reference peak", where n is a positive number.

[0073] In addition, the condition diagnosis unit 130 may be configured to calculate a reference change rate for each of the plurality of reference peaks based on the voltage of a reference peak corresponding to the set reference peak among a plurality of reference peaks corresponding to the plurality of target peaks.

[0074] For example, the condition diagnosis unit 130 may calculate a reference rate of change for each of the second reference peak P2, the third reference peak P3, and the fourth reference peak P4 based on the voltage of the first reference peak P1 corresponding to the base peak TP1. Here, it is assumed that the reference rate of change for the first reference peak P1 is 0 and therefore can be omitted. Here, the condition diagnosis unit 130 may apply the method for calculating the voltage rate of change of the target peak to the multiple reference peaks to calculate the reference rate of change for each of the reference peaks.

[0075] Meanwhile, since the reference peaks are preset, the reference change rates for the multiple reference peaks can also be preset.

[0076] The condition diagnosis unit 130 may be configured to compare the corresponding voltage change rates with the reference change rates based on the correspondence between the plurality of target peaks and the plurality of reference peaks.

[0077] For example, the condition diagnosis unit 130 may compare the second voltage change rate for the second target peak TP2 with the second reference change rate for the second reference peak P2. The condition diagnosis unit 130 may also compare the third voltage change rate for the third target peak TP3 with the third reference change rate for the third reference peak P3. The condition diagnosis unit 130 may also compare the fourth voltage change rate for the fourth target peak TP4 with the fourth reference change rate for the fourth reference peak P4.

[0078] The status diagnosis unit 130 may be configured to diagnose the status of the battery based on a result of the change rate comparison and a result of the voltage comparison.

[0079] Specifically, the condition diagnosis unit 130 may be configured to diagnose the battery condition as abnormal if the voltage and the voltage change rate of at least one of the multiple target peaks are less than the voltage and the reference change rate of the corresponding reference peak.

[0080] That is, the state diagnosis unit 130 may diagnose the state of the battery by taking into consideration not only the voltages of the target peaks and the reference peaks but also the voltage change rate.

[0081] Specifically, the status diagnosis unit 130 may diagnose the status of the second battery B2 as abnormal if the voltage change rate of the second battery B2 relative to the target peak is less than the reference change rate of the corresponding reference peak of the first battery B1, and the voltage of the target peak of the second battery B2 is less than the voltage of the corresponding reference peak of the first battery B1.

[0082] For example, referring to the embodiment of Figures 3 and 4, the voltage Vtp2 for the second target peak TP2 may be less than the voltage Vp2 for the second reference peak P2. However, the voltage change rate for the second target peak TP2 may be greater than the reference change rate for the second reference peak P2. As a result, the status diagnosis unit 130 may not diagnose the status of the second battery B2 as an abnormal status based on the embodiment of Figures 3 and 4.

[0083] In another example, referring to the embodiment of FIG. 3 and FIG. 5, the voltage Vtp3 for the third target peak TP3 may be less than the voltage Vp3 for the third reference peak P3. Also, the voltage change rate for the third target peak TP3 may be less than the reference change rate for the third reference peak P3. Similarly, referring to the embodiment of FIG. 3 and FIG. 6, the voltage Vtp4 for the fourth target peak TP4 may be less than the voltage Vp4 for the fourth reference peak P4. Also, the voltage change rate for the fourth target peak TP4 may be less than the reference change rate for the fourth reference peak P4. Thus, the state diagnosis unit 130 may diagnose the state of the second battery B2 as an abnormal state based on the embodiment of FIG. 3, FIG. 5, and FIG. 6.

[0084] The battery status diagnosis device 100 according to an embodiment of the present invention has an advantage that it can diagnose the battery status more accurately by considering not only the battery voltage but also the voltage change rate. In particular, the battery status diagnosis device 100 has an advantage that it can specifically diagnose the abnormal battery status that may have a sudden drop in SOH based on the battery voltage and voltage change rate. This makes it possible to easily select batteries that are at risk of a sudden drop in SOH without continuously tracking the SOH of the battery during the battery life cycle.

[0085] More specifically, the condition diagnosis unit 130 may determine an increase / decrease pattern of the voltage change rate corresponding to the multiple target peaks, and may be configured to diagnose the battery state as abnormal when the determined increase / decrease pattern is an increase pattern and the voltage and voltage change rate of at least one of the multiple target peaks are lower than the voltage and reference change rate of the corresponding reference peak.

[0086] 3 to 6, the voltages corresponding to the first to fourth target peaks TP1 to TP4 may increase as the second battery B2 degenerates. That is, the voltage change rate of the second battery B2 may gradually increase as time passes from the second point (SOH 0.97), to the third point (SOH 0.95), and to the fourth point (SOH 0.92). Thus, the condition diagnosis unit 130 may determine the increase / decrease pattern of the voltage change rate for the second battery B2 to be an increase pattern.

[0087] Thereafter, the status diagnosis unit 130 may compare the voltage and the reference change rate of a reference peak corresponding to at least one voltage and a voltage change rate of the plurality of target peaks for the second battery B2, and diagnose the status of the second battery B2 based on the comparison result.

[0088] As in the above example, the voltage Vtp3 for the third target peak TP3 may be less than the voltage Vp3 for the third reference peak P3, and the voltage Vtp4 for the fourth target peak TP4 may be less than the voltage Vp4 for the fourth reference peak P4. Also, the voltage change rate for the third target peak TP3 may be less than the reference change rate for the third reference peak P3, and the voltage change rate for the fourth target peak TP4 may be less than the reference change rate for the fourth reference peak P4.

[0089] Therefore, the state diagnosis unit 130 can diagnose the state of the second battery B2 as an abnormal state.

[0090] That is, the battery status diagnosis device 100 according to an embodiment of the present invention has an advantage in that it can diagnose the battery status more quickly by specifically comparing the target peak with the reference peak after first considering the increase / decrease pattern of the voltage change rate of the battery. In particular, when the battery status diagnosis device 100 determines that the voltage change rate of the battery is an increasing pattern, it can determine that the deterioration of the battery is gradually accelerating, and only in this case can it diagnose whether the battery is likely to suddenly drop, thereby more quickly and accurately diagnosing the battery status.

[0091] The battery state diagnosis device 100 according to the present invention is applicable to a BMS (Battery Management System). That is, the BMS according to the present invention may include the above-mentioned battery state diagnosis device 100. In this configuration, at least a part of the components of the battery state diagnosis device 100 may be implemented by complementing or adding functions of components included in a conventional BMS. For example, the profile acquisition unit 110, the peak determination unit 120, the state diagnosis unit 130, and the storage unit 140 of the battery state diagnosis device 100 may be implemented as components of a BMS.

[0092] Also, the battery state diagnosis device 100 according to the present invention may be provided in a battery pack 1. That is, the battery pack 1 according to the present invention may include the battery state diagnosis device 100, a measuring unit 200, and one or more batteries B. Also, the battery pack 1 may further include electrical components (relays, fuses, etc.), a case, etc.

[0093] FIG. 7 is a diagram illustrating an exemplary configuration of a battery pack 1 according to another embodiment of the present invention.

[0094] The measurement unit 200 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3.

[0095] Specifically, the first sensing line SL1 may be connected to the positive electrode of the battery B and the measurement unit 200. Also, the second sensing line SL2 may be connected to the negative electrode of the battery B and the measurement unit 200. The measurement unit 200 may measure the voltage of the battery B by calculating a difference between the positive electrode voltage of the battery B measured by the first sensing line SL1 and the negative electrode voltage of the battery B measured by the second sensing line SL2.

[0096] Furthermore, the measurement unit 200 may measure the charging current and / or discharging current of the battery B through a current measurement unit A connected to the third sensing line SL3. For example, the current measurement unit A may be a shunt resistor or an ammeter.

[0097] The voltage and current of battery B measured by the measurement unit 200 can be transmitted to the battery condition diagnosis device 100.

[0098] For example, the profile acquiring unit 110 may receive the voltage and current of battery B from the measuring unit 200. The profile acquiring unit 110 may generate a differential profile indicating a correspondence relationship between the voltage and differential capacity of battery B based on the received voltage and current of battery B.

[0099] In another example, the storage unit 140 may receive and store the voltage and current of battery B from the measurement unit 200. The profile acquisition unit 110 may access the storage unit 140 to acquire a battery profile for the voltage and current of battery B, and generate a differential profile based on the acquired battery profile.

[0100] In still another example, the profile acquiring unit 110 may directly receive and acquire the differential profile indicating the correspondence between the differential capacity and voltage of the battery B from the measuring unit 200 .

[0101] FIG. 8 is a diagram illustrating a battery state diagnosis method according to still another embodiment of the present invention.

[0102] Preferably, each step of the battery state diagnosis method may be performed by the battery state diagnosis device 100. In the following, the contents overlapping with those described above will be omitted or will be briefly described.

[0103] Referring to FIG. 8, a battery state diagnosis method according to still another embodiment of the present invention may include a profile acquisition step S100, a peak determination step S200, a comparison step S300, and a state diagnosis step S400.

[0104] The profile acquiring step S100 is a step of acquiring a plurality of differential profiles indicating a correspondence relationship between a differential capacity indicating a capacity change rate of the battery with respect to a voltage of the battery and the voltage, and may be performed by the profile acquiring unit 110.

[0105] For example, in the embodiment of FIGS. 3 to 6, the profile acquirer 110 may acquire a plurality of differential profiles for the second battery B2.

[0106] The peak determining step S200 may be performed by the peak determining unit 120 as a step of determining a target peak located in a predetermined voltage section in each of the plurality of differential profiles.

[0107] For example, in the embodiment of Fig. 3 to Fig. 6, the peak determination unit 120 may determine a target peak from each of the multiple derivative profiles for the second battery B2. Specifically, the peak determination unit 120 may determine a first target peak TP1 from the first derivative profile DP, and a second target peak TP2 from the second derivative profile DP2. The peak determination unit 120 may also determine a third target peak TP3 from the third derivative profile DP3, and a fourth target peak TP4 from the fourth derivative profile DP4.

[0108] The comparing step S300 is a step of comparing the voltages of the plurality of target peaks determined in the peak determining step S200 with the voltages of reference peaks preset to correspond to the plurality of target peaks, and may be performed by the status diagnosis unit 130.

[0109] For example, the condition diagnosis unit 130 may compare the voltages and / or voltage change rates of corresponding target peaks and reference peaks.

[0110] The state diagnosis step S400 is a step of diagnosing the state of the battery based on the voltage comparison result in the comparison step S300, and may be performed by the state diagnosis unit 130.

[0111] For example, the condition diagnosis unit 130 may diagnose the battery condition, which may be abruptly reduced in SOH, as an abnormal condition based on the comparison result.

[0112] The embodiments of the present invention described above may not necessarily be embodied through an apparatus and method, but may be embodied through a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation should be easily embodied by a person skilled in the art to which the present invention pertains from the description of the above-mentioned embodiments.

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

[0114] Furthermore, since the above-mentioned invention can be variously replaced, modified, and altered by a person having ordinary knowledge in the technical field to which the invention belongs without departing from the technical concept of the invention, it is not limited to the above-mentioned embodiments and the attached drawings, and can be configured by selectively combining all or part of each embodiment to make various modifications. [Explanation of symbols]

[0115] 1 Battery Pack 100 Battery condition diagnostic device 110 Profile Acquisition Department 120 Peak determination unit 130 Condition Diagnosis Unit 140 Preservation Department 200 Measuring section B. Battery

Claims

1. a profile acquisition unit that acquires a plurality of differential profiles that indicate a correspondence relationship between a differential capacity indicating a rate of change in capacity of the battery relative to a voltage of the battery and the voltage; a peak determiner for determining a target peak located in a predetermined voltage range from each of the plurality of differential profiles of the battery; a condition diagnosis unit that compares voltages of a plurality of target peaks determined from each of the plurality of differential profiles of the battery by the peak determination unit with voltages of reference peaks that are preset to correspond to each of the plurality of target peaks, and diagnoses a condition of the battery using each of the plurality of voltage comparison results.

2. The condition diagnosis unit is The battery condition diagnosis device according to claim 1 , wherein when the voltage of at least one of the plurality of target peaks is lower than the voltage of the corresponding reference peak, the battery condition is diagnosed as being abnormal.

3. The condition diagnosis unit is 3. The battery state diagnosis device according to claim 1, further comprising: a reference peak is set among the plurality of target peaks; and a voltage change rate for each of the plurality of target peaks is calculated based on the voltage of the set reference peak.

4. The condition diagnosis unit is 4. The battery state diagnosis device according to claim 3, further comprising: a reference change rate for each of a plurality of reference peaks corresponding to the plurality of target peaks, the reference change rate being calculated based on a voltage of a reference peak corresponding to the set reference peak among a plurality of reference peaks corresponding to the plurality of target peaks.

5. The condition diagnosis unit is 5. The battery condition diagnosis device according to claim 4, further comprising: a voltage change rate and a reference change rate are compared based on a correspondence relationship between the plurality of target peaks and the plurality of reference peaks; and a state of the battery is diagnosed based on a change rate comparison result and the plurality of voltage comparison results.

6. The condition diagnosis unit is 6. The battery condition diagnosis device according to claim 4, wherein when the voltage and the voltage change rate of at least one of the plurality of target peaks are lower than the voltage and the reference change rate of a corresponding one of the reference peaks, the battery condition is diagnosed as being abnormal.

7. The profile acquisition unit includes:

7. The battery condition diagnostic device according to claim 1, further comprising: obtaining differential profiles for the battery at different times.

8. The plurality of time points are 8. The battery condition diagnostic device of claim 7, wherein the battery is at multiple cycle or degradation time points.

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

10. A profile acquisition step of acquiring a plurality of differential profiles showing a correspondence relationship between a differential capacity indicating a capacity change rate of the battery with respect to a voltage of the battery and the voltage; determining a target peak located in a predetermined voltage range from each of the plurality of differential profiles of the battery; a comparing step of comparing voltages of a plurality of target peaks determined from each of the plurality of differential profiles of the battery in the peak determining step with voltages of reference peaks preset to correspond to each of the plurality of target peaks; a state diagnosis step of diagnosing a state of the battery using each of the plurality of voltage comparison results compared in the comparison step.

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