Battery diagnostic device and method

Abstract

A battery diagnostic device according to an embodiment of the present invention includes: a profile acquisition unit configured to acquire a differential profile indicating a correspondence relationship between a voltage of a battery and a differential capacity with respect to the voltage; and a control unit configured to determine a target peak from the differential profile, determine a first comparison result by comparing the voltage and the differential capacity between a reference peak of a preset reference profile for the battery and the determined target peak, and determine a state of the battery based on the first comparison result and the second comparison result.

Description

[Technical Field]

[0001] The present invention relates to a battery diagnostic device and method, and more particularly to a battery diagnostic device and method for diagnosing the state of a battery in a non-destructive manner.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0143795, filed on November 1, 2022, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference. [Background technology]

[0003] Recently, as demand for portable electronic products such as notebook PCs, video cameras, and mobile phones has skyrocketed, and development of electric vehicles, energy storage batteries, robots, and satellites has gained momentum, research into high-performance batteries that can be repeatedly charged and discharged is actively underway.

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

[0005] Generally, a battery includes a positive electrode and a negative electrode and has the characteristic of deteriorating with use. The degree of deterioration of the positive electrode and the negative electrode can vary depending on various factors such as the usage environment and usage history of the battery.

[0006] In addition, disassembling a battery during operation is difficult, and accidents such as explosions can occur during the disassembly process. In other words, it is virtually impossible to directly check the status of the positive and negative electrodes by disassembling the battery. Therefore, there is a need to develop a technology that can diagnose the battery status based on battery-related information using a non-destructive method. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above problems, and has as its object to provide a battery diagnostic device and method that can diagnose the state of a battery in a non-destructive manner.

[0008] Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 2 is a block diagram of a semiconductor device according to an embodiment of the present invention; [Means for solving the problem]

[0009] A battery diagnostic device according to one aspect of the present invention may include: a profile acquisition unit configured to acquire a differential profile indicating a correspondence relationship between a voltage of a battery and a differential capacity with respect to the voltage; and a control unit configured to determine a target peak from the differential profile, determine a first comparison result by comparing the voltage and a second comparison result by comparing the differential capacity between a reference peak of a preset reference profile for the battery and the determined target peak, and determine a state of the battery based on the first comparison result and the second comparison result.

[0010] The control unit may be configured to compare the magnitude of the voltage between the reference peak and the target peak and determine the first comparison result as a first state or a second state.

[0011] The control unit may be configured to compare the magnitude of the differential capacity between the reference peak and the target peak, and determine the second comparison result as the first state or the second state.

[0012] The control unit may be configured to determine the first comparison result as the first state when the voltage of the target peak exceeds the voltage of the reference peak.

[0013] The control unit may be configured to determine the first comparison result as the second state when the voltage of the target peak is less than the voltage of the reference peak.

[0014] The controller may be configured to determine the second comparison result as the first state when a differential volume of the target peak exceeds a differential volume of the reference peak.

[0015] The controller may be configured to determine the second comparison result as the second state when the differential volume of the target peak is less than the differential volume of the reference peak.

[0016] The control unit may be configured to determine a state of the positive electrode of the battery based on the first comparison result and the second comparison result.

[0017] The control unit may be configured to determine, when the second comparison result is the second state, the state of the positive electrode of the battery as a first degraded state or a second degraded state based on the first comparison result.

[0018] The control unit may be configured to determine that the state of the positive electrode of the battery is the first deteriorated state when the second comparison result is determined to be the second state and the first comparison result is determined to be the second state.

[0019] The control unit may be configured to determine that the state of the positive electrode of the battery is the second deteriorated state when the second comparison result is determined to be the second state and the first comparison result is determined to be the first state.

[0020] The control unit may be configured to reduce at least one of an upper limit of a charge / discharge C-rate and an upper limit of a usable SOC preset for the battery when the positive electrode state is determined to be the second degraded state, or to dispose of the battery.

[0021] 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.

[0022] According to yet another aspect of the present invention, a battery diagnosis method may include: a differential profile obtaining step of obtaining a differential profile indicating a correspondence relationship between a voltage of a battery and a differential capacity with respect to the voltage; a target peak determining step of determining a target peak from the differential profile; a comparison result determining step of determining a first comparison result by comparing the voltage and the determined target peak with a reference peak of a reference profile preset for the battery, and a second comparison result by comparing the differential capacity; and a battery state determining step of determining a state of the battery based on the first comparison result and the second comparison result. [Effects of the Invention]

[0023] According to one aspect of the present invention, a battery diagnostic device can diagnose the electrode state of a battery by taking into account peak behavior in a differential profile of the battery. That is, the battery diagnostic device can diagnose the battery state more specifically in a non-destructive manner.

[0024] Furthermore, according to one aspect of the present invention, the battery diagnostic device has an advantage in that it can set usage conditions appropriate for the current state of the battery.

[0025] 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.

[0026] 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 concept of the present invention, so the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0027] [Figure 1]1 is a diagram illustrating a battery diagnostic device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram illustrating a battery profile according to an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram illustrating a differential profile according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating a reference profile and a derivative profile according to an embodiment of the present invention. [Figure 5] FIG. 2 is a diagram illustrating a diagnostic table according to an embodiment of the present invention. [Figure 6] FIG. 10 is a diagram illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 7] 10 is a diagram illustrating a battery diagnostic method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying 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 explain the invention.

[0029] 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.

[0030] 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, that description will be omitted.

[0031] Terms including ordinal numbers such as "first," "second," etc. are used to distinguish one of various components from the rest, and do not limit the components.

[0032] Furthermore, throughout the specification, when a part is said to "include" a certain component, this does not mean that it excludes other components, but that it may further include other components, unless otherwise specified.

[0033] Furthermore, throughout this specification, when a part is said to be "coupled" to another part, this includes not only "directly coupled" but also "indirectly coupled" via another element in between.

[0034] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] FIG. 1 is a schematic diagram of a battery diagnostic device 100 according to an embodiment of the present invention. Herein, a battery refers to a single, independent cell that has a negative terminal and a positive terminal and that can be physically separated. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. A battery may also refer to a battery module in which multiple cells are connected in series and / or parallel. Hereinafter, for convenience of explanation, a battery will be referred to as a single, independent cell.

[0036] Referring to FIG. 1, a battery diagnostic device 100 according to an embodiment of the present invention may include a profile acquisition unit 110 and a control unit 120.

[0037] The profile acquisition unit 110 may be configured to acquire a differential profile that indicates a correspondence relationship between the voltage of the battery and the differential capacity with respect to the voltage.

[0038] Here, the differential capacity is a value obtained by differentiating the capacity of a battery with respect to voltage, and can be expressed as dQ / dV. That is, the differential capacity can be defined as the instantaneous rate of change of capacity with respect to voltage.

[0039] In one embodiment, the profile acquirer 110 may directly acquire the gradient profile from an external source, for example, by receiving a pre-generated gradient profile.

[0040] In another embodiment, the profile acquirer 110 may be configured to externally acquire a battery profile indicating a correspondence relationship between the voltage and capacity of a battery, and the profile acquirer 110 may acquire the differential profile by directly generating the differential profile from the battery profile.

[0041] In yet another embodiment, the profile acquirer 110 may acquire battery information including the voltage and capacity of the battery. Then, the profile acquirer 110 may generate a battery profile indicating a correspondence relationship between the voltage and the capacity based on the battery information. Here, the voltage and capacity of the battery may be measured by a measuring device, and the profile acquirer 110 may acquire the measured battery information. The profile acquirer 110 may directly generate the battery profile from the battery information.

[0042] Although the above describes a restrictive example in which the profile acquirer 110 acquires a differential profile, the profile acquirer 110 can acquire a differential profile for a battery in various ways other than the above-described restrictive example.

[0043] FIG. 2 is a diagram illustrating a battery profile according to an embodiment of the present invention.

[0044] In the embodiment of FIG. 2, the battery profile is a profile showing the correspondence relationship between the capacity and voltage of the battery. The battery profile may be represented by an XY graph where X is set to capacity and Y is set to voltage. The positive electrode profile is a profile relating to the positive electrode of the battery, and the negative electrode profile is a profile relating to the negative electrode of the battery. Preferably, the profile acquirer 110 may acquire the battery profile shown in the embodiment of FIG. 2. Depending on the embodiment, the profile acquirer 110 may acquire both the positive electrode profile and the negative electrode profile.

[0045] FIG. 3 is a diagram illustrating a differential profile DP according to an embodiment of the present invention.

[0046] In the example of FIG. 3, the differential profile DP can be shown on an XY graph where X is set to voltage V and Y is set to differential capacitance dQ / dV.

[0047] The control unit 120 may be configured to determine a target peak from the differential profile DP.

[0048] Specifically, the differential profile DP may include multiple peaks. Here, a peak may be a point in the differential profile DP where the gradient is zero and the profile has an upwardly bulging shape. In other words, a peak may be a point where the instantaneous rate of change of differential capacitance with respect to voltage is zero and the gradient of the differential profile DP changes from positive to negative. In the example of FIG. 3, the differential profile DP may include a first peak p1, a second peak p2, a third peak p3, a fourth peak p4, and a fifth peak p5.

[0049] The controller 120 may determine a peak belonging to a predetermined target voltage range VR among a plurality of peaks included in the differential profile DP as a target peak. Here, the predetermined target voltage range VR may refer to the uppermost voltage range of the entire voltage range of the battery. For example, for a 4.2V battery, the target voltage range VR may be set to approximately 4V to 4.2V.

[0050] More specifically, the target voltage section VR may be preset to a voltage section in which a peak corresponding to the fifth peak p5 appears. The fifth peak p5 is a peak that appears in the differential profile DP of a nickel-containing battery. For example, the fifth peak p5 is a peak that appears in the differential profile DP of a high-nickel battery having a nickel content of 70% or more. Typically, the target voltage section VR in which the fifth peak p5 appears in the differential profile DP of a high-nickel battery is known as a voltage section corresponding to a range of 80% to 100% of the battery's State of Charge (SOC). That is, a voltage section corresponding to an SOC of 80% to 100% may be preset as the target voltage section VR. Therefore, the control unit 120 may determine, as the target peak, a peak that belongs to the preset target voltage section VR from among the multiple peaks included in the differential profile DP.

[0051] In the example of FIG. 3, the control unit 120 can determine the fifth peak p5 from among the plurality of peaks p1 to p5 as the target peak.

[0052] The control unit 120 may be configured to determine a first comparison result that compares the voltage between a reference peak of a preset reference profile for the battery and the determined target peak, and a second comparison result that compares the differential capacity between the reference peak and the determined target peak.

[0053] Specifically, the reference profile is a profile that indicates the correspondence relationship between the voltage and differential capacity of a reference battery. Here, the reference battery may be a battery in a beginning of life (BOL) state or an experimental battery corresponding to a battery in the BOL state. That is, the reference profile may be preset based on the voltage and capacity of the reference battery. Among the multiple peaks included in the reference profile, a peak that belongs to the target voltage range VR may be determined as the reference peak.

[0054] Preferably, the control unit 120 may determine a first comparison result by comparing the magnitude of the voltage between the reference peak and the target peak, and may determine a second comparison result by comparing the magnitude of the differential capacitance between the reference peak and the target peak.

[0055] FIG. 4 is a schematic diagram of a reference profile RP and a derivative profile DP according to one embodiment of the present invention.

[0056] For example, in the embodiment of FIG. 4, assume that the reference profile RP includes a reference peak rp and the differential profile DP includes a target peak tp. The reference peak rp has a voltage Vr and a differential capacitance Dr. The target peak tp has a voltage Vt and a differential capacitance Dt. The control unit 120 may determine a first comparison result by comparing the voltage Vr of the reference peak rp with the voltage Vt of the target peak tp. Then, the control unit 120 may determine a second comparison result by comparing the differential capacitance Dr of the reference peak rp with the differential capacitance Dt of the target peak tp.

[0057] 4, the control unit 120 may determine the first comparison result by taking into consideration that the voltage Vt of the target peak tp is smaller than the voltage Vr of the reference peak rp, and may determine the second comparison result by taking into consideration that the differential capacitance Dt of the target peak tp is smaller than the differential capacitance Dr of the reference peak rp.

[0058] The control unit 120 may be configured to determine the state of the battery based on the first comparison result and the second comparison result.

[0059] Specifically, the control unit 120 may determine the state of the battery based on a combination of the first comparison result and the second comparison result. For example, the control unit 120 may diagnose the state of the positive electrode of the battery based on the first comparison result and the second comparison result.

[0060] The battery diagnostic device 100 according to an embodiment of the present invention has an advantage in that it can diagnose the electrode state of a battery by taking into account peak behavior in the differential profile DP of the battery. That is, the battery diagnostic device 100 has an advantage in that it can diagnose the state of the battery more specifically by diagnosing the state of the positive electrode of the battery in a non-destructive manner.

[0061] Meanwhile, the control unit 120 included in the battery diagnostic device 100 may selectively include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, a communication modem, a data processing device, etc., known in the art, to execute various control logics performed in the present invention. When the control logic is embodied as software, the control unit 120 may be embodied as a collection of program modules. In this case, the program modules may be stored in a memory and executed by the control unit 120. The memory may be internal or external to the control unit 120 and may be connected to the control unit 120 by various known means.

[0062] The battery diagnostic device 100 may further include a storage unit 130. The storage unit 130 may store data and programs required for each component of the battery diagnostic device 100 to operate and function, or data generated during the operation and function. The storage unit 130 may be any 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 130 may also store program code defining processes executable by the control unit 120.

[0063] An embodiment in which the control unit 120 determines the first comparison result and the second comparison result will be described in detail below.

[0064] The control unit 120 may be configured to compare the voltage magnitudes of the reference peak rp and the target peak tp and determine the first comparison result as the first state or the second state.

[0065] Specifically, if the voltage of the target peak tp exceeds the voltage of the reference peak rp, the control unit 120 may determine the first comparison result as the first state. Conversely, if the voltage of the target peak tp is less than the voltage of the reference peak rp, the control unit 120 may determine the first comparison result as the second state.

[0066] In the embodiment of FIG. 4, since the voltage Vt of the target peak tp is smaller than the voltage Vr of the reference peak rp, the control unit 120 can determine the first comparison result as the second state.

[0067] The control unit 120 may be configured to compare the magnitude of the differential capacitance between the reference peak rp and the target peak tp, and determine the second comparison result as the first state or the second state.

[0068] Specifically, if the differential capacity of the target peak tp exceeds the differential capacity of the reference peak rp, the control unit 120 may determine the second comparison result as the first state. Conversely, if the differential capacity of the target peak tp is less than the differential capacity of the reference peak rp, the control unit 120 may determine the second comparison result as the second state.

[0069] In the example of FIG. 4, the differential capacity Dt of the target peak tp is smaller than the differential capacity Dr of the reference peak rp, so the control unit 120 can determine the second comparison result as the second state.

[0070] That is, in the first comparison result and the second comparison result, the first state means a state in which the current value exceeds the reference value, and the second state means a state in which the current value is less than the reference value.

[0071] Unlike the embodiment of FIG. 4, when the voltage and differential capacitance of the target peak tp exceed the voltage and differential capacitance of the reference peak rp, the first comparison result and the second comparison result may both be determined to be in the first state.

[0072] The battery diagnostic device 100 according to an embodiment of the present invention may independently determine a voltage comparison result (first comparison result) between the target peak tp and the reference peak rp and a differential capacity comparison result (second comparison result). Since the battery state is diagnosed based on the independently determined first and second comparison results, the reliability and accuracy of the state diagnosis result are increased.

[0073] Hereinafter, an embodiment in which the control unit 120 diagnoses the battery state based on the first comparison result and the second comparison result will be described in detail.

[0074] 5 is a diagram illustrating a diagnosis table according to an embodiment of the present invention. Specifically, the diagnosis table of FIG. 5 may be a table used to diagnose the state of the positive electrode of a battery based on the first comparison result and the second comparison result.

[0075] 5, if the second comparison result indicates the second state, the control unit 120 may be configured to determine the state of the battery's positive electrode. That is, if the differential capacity Dt of the target peak tp is less than the differential capacity Dr of the reference peak rp, the control unit 120 may determine the state of the battery's positive electrode based on the first comparison result. Specifically, if the second comparison result indicates the second state, the control unit 120 may be configured to determine the state of the battery's positive electrode as a first deteriorated state or a second deteriorated state based on the first comparison result.

[0076] For example, when the voltage Vt of the target peak tp is smaller than the voltage Vr of the reference peak rp (when the first comparison result is the second state), the control unit 120 can diagnose the state of the positive electrode as the first deteriorated state.

[0077] Here, the first deterioration state indicates a state in which cracks occur between active material particles inside the battery, and may indicate a normal battery deterioration state (for example, linear deterioration).

[0078] In another example, when the voltage Vt of the target peak tp exceeds the voltage Vr of the reference peak rp (when the first comparison result is the first state), the control unit 120 may diagnose the state of the positive electrode as the second deteriorated state.

[0079] The second degradation state may indicate a state in which cracks occur inside the active material particles, accelerating the degradation of the battery, which may result in a sudden increase in gas generation inside the battery or a decrease in capacity.

[0080] Therefore, the battery diagnostic device 100 can quickly and non-destructively diagnose the state of the battery based on the differential capacity comparison result (second comparison result) and voltage comparison result (first comparison result) between the target peak tp and the reference peak rp.

[0081] In the following, an embodiment will be described in which the control unit 120 controls the conditions for using the battery based on the determined battery state.

[0082] Specifically, the control unit 120 may set the usage conditions for the battery based on the state of the positive electrode of the battery. Here, the initial usage conditions for the battery may be set in advance. Then, the control unit 120 may change the usage conditions depending on the determined state of the positive electrode.

[0083] If the positive electrode state is determined to be in the second degradation state, the control unit 120 may reduce at least one of the upper limit of the charge / discharge C-rate and the upper limit of the available SOC preset for the battery. In some embodiments, the control unit 120 may be configured to dispose of the battery.

[0084] For example, if the state of the positive electrode of the battery is in the second degradation state, the control unit 120 may reduce the upper limit of the charge C-rate to prevent further degradation of the positive electrode. That is, the control unit 120 may relax the conditions for fast charging the battery. Therefore, fast charging of the battery may be prevented or the fast charging level (e.g., fast charging intensity) may be adjusted downward.

[0085] In another example, when the state of the positive electrode of the battery is in the second degraded state, the control unit 120 may reduce the upper limit of the available SOC to prevent further degradation of the positive electrode. That is, when the positive electrode state is in the degraded state, the use of the positive electrode on the SOC side (i.e., the high potential side) may be limited.

[0086] In yet another example, if the state of the positive electrode of the battery is in the second deteriorated state, the control unit 120 may be configured to dispose of the battery. That is, if the state of the positive electrode of the battery is diagnosed as being in the second deteriorated state, cracks inside the active material particles may cause gas generation and / or capacity reduction inside the battery. Internal gas generation may cause battery venting, which may lead to accidents such as fire and / or explosion. Therefore, the control unit 120 may be configured to dispose of the battery to prevent such accidents in advance.

[0087] 4, the control unit 120 may diagnose the state of the positive electrode of the battery as the first deteriorated state, and therefore the control unit 120 does not need to change the usage conditions preset for the battery.

[0088] The battery diagnostic device 100 according to an embodiment of the present invention has an advantage in that it can appropriately set the usage conditions of the battery based on the state of the positive electrode. Since the usage conditions are appropriately set based on the current state of the battery, further deterioration of the battery can be prevented or delayed. In other words, the battery diagnostic device 100 can improve the expected lifespan of the battery.

[0089] The battery diagnostic device 100 according to the present invention may be applied to a BMS (Battery Management System). 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 complementing or adding functions of components included in a conventional BMS. For example, the profile acquisition unit 110, the control unit 120, and the storage unit 130 of the battery diagnostic device 100 may be implemented as components of the BMS.

[0090] The battery diagnostic device 100 according to the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the battery diagnostic device 100 and one or more battery cells. The battery pack may further include electrical components (relays, fuses, etc.), a case, etc.

[0091] FIG. 6 is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention.

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

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

[0094] The measurement unit 20 may be connected to the current measurement unit A via a third sensing line SL3. For example, the current measurement unit A may be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery 10. The measurement unit 20 may measure the charging current of the battery 10 via the third sensing line SL3 to calculate the charged amount. The measurement unit 20 may also measure the discharging current of the battery 10 via the third sensing line SL3 to calculate the discharged amount.

[0095] A charge / discharge device or a load may be connected to the positive terminal P+ and the negative terminal P- of the battery pack 1. One end of the load may be connected to the positive terminal P+ of the battery pack 1, and the other end may be connected to the negative terminal P- of the battery pack 1. This allows electrical connections to be made between the positive terminal of the battery 10, the positive terminal P+ of the battery pack 1, the load, the negative terminal P- of the battery pack 1, and the negative terminal of the battery 10.

[0096] The profile acquisition unit 110 may acquire a battery profile by receiving the voltage and capacity related to the battery 10 from the measurement unit 20. The profile acquisition unit 110 may then generate a differential profile DP from the acquired battery profile.

[0097] For example, battery information including the voltage and capacity of the battery 10 measured by the measurement unit 20 may be stored in the storage unit 130. The battery profile and differential profile DP may also be stored in the storage unit 130.

[0098] FIG. 7 is a diagram illustrating a battery diagnostic method according to another embodiment of the present invention.

[0099] Preferably, each step of the battery diagnostic method may be performed by the battery diagnostic device 100. Hereinafter, for the sake of convenience, the overlapping content with the above content will be omitted or will be briefly described.

[0100] Referring to FIG. 7, the battery diagnostic method may include a differential profile obtaining step S100, a target peak determining step S200, a comparison result determining step S300, and a battery state determining step S400.

[0101] The differential profile obtaining step S100 is a step of obtaining a differential profile DP indicating a correspondence relationship between the voltage of the battery and the differential capacity with respect to the voltage, and can be performed by the profile obtaining unit 110.

[0102] For example, the profile acquirer 110 may directly receive the differential profile DP for the battery or generate it based on the battery profile.

[0103] The target peak determination step S200 is a step of determining a target peak tp from the differential profile DP, and can be performed by the control unit 120.

[0104] For example, the control unit 120 may determine a peak that belongs to the target voltage range VR among a plurality of peaks included in the differential profile DP as the target peak tp.

[0105] In the embodiment of FIG. 3, the control unit 120 may determine the fifth peak p5 among the plurality of peaks p1 to p5 included in the differential profile DP as the target peak tp.

[0106] The comparison result determination step S300 is a step of determining a first comparison result of comparing the voltage between a reference peak rp of a reference profile RP preset for the battery and the determined target peak tp, and a second comparison result of comparing the differential capacity, and can be performed by the control unit 120.

[0107] The control unit 120 may determine a first comparison result by comparing the magnitude of the voltage of the target peak tp with the magnitude of the voltage of the reference peak rp, and may determine a second comparison result by comparing the magnitude of the differential capacity of the target peak tp with the magnitude of the differential capacity of the reference peak rp.

[0108] For example, if the voltage of the target peak tp exceeds the voltage of the reference peak rp, the first comparison result may be determined to be in the first state. Conversely, if the voltage of the target peak tp is less than the voltage of the reference peak rp, the first comparison result may be determined to be in the second state.

[0109] In another example, if the differential capacity of the target peak tp exceeds the differential capacity of the reference peak rp, the second comparison result may be determined to be the first state. Conversely, if the differential capacity of the target peak tp is less than the differential capacity of the reference peak rp, the second comparison result may be determined to be the second state.

[0110] Here, the first state is a state in which the current value (e.g., the value of the target peak tp) exceeds a reference value (e.g., the value of the reference peak rp), and the second state is a state in which the current value is less than the reference value.

[0111] 4, the voltage Vt of the target peak tp is less than the voltage Vr of the reference peak rp, so the first comparison result can be determined to be the second state. And the differential capacitance Dt of the target peak tp is less than the differential capacitance Dr of the reference peak rp, so the second comparison result can be determined to be the second state.

[0112] The battery state determination step S400 is a step of determining the state of the battery based on the first comparison result and the second comparison result, and may be performed by the control unit 120.

[0113] Specifically, the control unit 120 may determine the state of the positive electrode of the battery based on the first comparison result and the second comparison result.

[0114] Preferably, when the second comparison result indicates the second state, the control unit 120 may determine the state of the positive electrode of the battery as the first degraded state or the second degraded state based on the first comparison result. That is, when the differential capacity Dt of the target peak tp is less than the differential capacity Dr of the reference peak rp, the control unit 120 may diagnose the state of the positive electrode based on the result of comparing the voltage Vt of the target peak tp with the voltage Vr of the reference peak rp.

[0115] For example, if the second comparison result is the second state and the first comparison result is the second state, the control unit 120 may determine that the state of the battery's positive electrode is the first degraded state. Conversely, if the second comparison result is the second state and the first comparison result is the first state, the control unit 120 may determine that the state of the battery's positive electrode is the second degraded state.

[0116] 4, the first comparison result is the second state, and the second comparison result is the second state, so that the control unit 120 can diagnose the state of the positive electrode of the battery as the first deteriorated state.

[0117] According to an embodiment, the control unit 120 may set usage conditions for the battery based on the diagnosis result, thereby preventing further deterioration of the battery.

[0118] The embodiments of the present invention described above are not necessarily embodied through devices and methods, 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.

[0119] 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 a person having ordinary skill in the art to which the present invention pertains within the technical spirit of the present invention and the scope of the claims.

[0120] Furthermore, since the above-mentioned present invention can be variously replaced, modified, and changed by a person having ordinary knowledge in the technical field to which the present invention belongs without departing from the technical concept of the present 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]

[0121] 1 battery pack 10 Battery 100 Battery diagnostic device 110 Profile Acquisition Unit 120 control section 130 Preservation Department

Claims

1. a profile acquisition unit configured to acquire a differential profile indicating a correspondence relationship between a voltage of the battery and a differential capacity with respect to the voltage; a control unit configured to determine a target peak from the differential profile, determine a first comparison result by comparing the voltage and the differential capacity between a reference peak of a reference profile preset for the battery and the determined target peak, and determine a state of the battery based on the first comparison result and the second comparison result.

2. The control unit comparing the magnitude of the voltage between the reference peak and the target peak to determine the first comparison result as a first state or a second state; 2. The battery diagnostic device according to claim 1, further comprising: a second comparison unit configured to compare the magnitude of the differential capacity between the reference peak and the target peak, and determine the second comparison result as the first state or the second state.

3. The control unit If the voltage of the target peak exceeds the voltage of the reference peak, the first comparison result is determined to be the first state; The battery diagnostic device according to claim 2 , further comprising: a first comparison result determining the second state when the target peak voltage is lower than the reference peak voltage.

4. The control unit If the differential volume of the target peak exceeds the differential volume of the reference peak, the second comparison result is determined to be the first state; The battery diagnostic device according to claim 2 , wherein the second comparison result is determined to be the second state when the differential capacity of the target peak is less than the differential capacity of the reference peak.

5. The control unit The battery diagnostic device according to claim 2 , further comprising: determining a state of the positive electrode of the battery based on the first comparison result and the second comparison result.

6. The control unit 6. The battery diagnostic device according to claim 5, wherein, when the second comparison result is the second state, the state of the positive electrode of the battery is determined to be a first deterioration state or a second deterioration state based on the first comparison result.

7. The control unit If the second comparison result is determined to be the second state and the first comparison result is determined to be the second state, the state of the positive electrode of the battery is determined to be the first deteriorated state; 7. The battery diagnostic device according to claim 6, wherein when the second comparison result is determined to be the second state and the first comparison result is determined to be the first state, the state of the positive electrode of the battery is determined to be the second deteriorated state.

8. The control unit 8. The battery diagnostic device of claim 7, further comprising: when the state of the positive electrode is determined to be in the second deteriorated state, the battery diagnostic device is configured to reduce at least one of an upper limit of a charge / discharge C-rate and an upper limit of a usable SOC preset for the battery, or to dispose of the battery.

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

10. a differential profile acquiring step of acquiring a differential profile indicating a correspondence relationship between a voltage of the battery and a differential capacity with respect to the voltage; a target peak determination step of determining a target peak from the differential profile; a comparison result determining step of determining a first comparison result obtained by comparing the voltage between a reference peak of a preset reference profile for the battery and the determined target peak, and a second comparison result obtained by comparing the differential capacity between the reference peak and the determined target peak; determining a battery state based on the first comparison result and the second comparison result.

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