Apparatus and method for diagnosing battery

Abstract

The present invention comprises: a storage unit for storing bank information on the voltage and capacity of each of a plurality of battery banks included in a battery module; and a control unit for generating a differential profile of each of the plurality of battery banks based on the bank information, determining a target peak from each of the plurality of generated differential profiles, and diagnosing a state of the corresponding battery bank based on the determined target peak.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2023-0009769 filed in Korea on January 25, 2023, and Korean Patent Application No. 10-2023-0009770 filed in Korea on January 25, 2023, the disclosures of which are incorporated herein by reference.

[0002] The present disclosure relates to an apparatus and method for diagnosing a battery, and more particularly, to an apparatus and method for diagnosing a battery, which are capable of diagnosing the status of a battery bank and / or a battery module. Background Art

[0003] Recently, the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has increased dramatically, and electric vehicles, energy storage batteries, robots, artificial satellites, etc. have been intensively developed. Therefore, high-performance batteries that allow repeated charging and discharging are being actively studied.

[0004] Batteries currently available on the market include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among them, lithium batteries have attracted much attention because they have almost no memory effect compared to nickel-based batteries and also have very low self-discharge rate and high energy density.

[0005] Although much research is being conducted on these batteries in terms of increasing capacity and density, improvements in lifespan and safety are also important. In order to improve battery safety, a technology that accurately diagnoses the current state of the battery is needed.

[0006] In particular, it is necessary to prevent lithium precipitation (lithium plating, Li plating) on ​​the negative electrode surface. When lithium is precipitated on the negative electrode surface, it causes a side reaction with the electrolyte and causes a change in the kinetic balance of the battery, thereby causing battery degradation. In addition, because lithium metal is precipitated on the negative electrode surface, an internal short circuit of the battery may occur, and therefore there is a risk of fire or explosion due to the internal short circuit. Therefore, it is necessary to develop a technology for preventing lithium metal precipitation by diagnosing the state of the battery. Summary of the invention

[0007] Technical issues

[0008] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure is directed to providing an apparatus and method for diagnosing a battery, which diagnoses the status of a battery bank and / or a battery module.

[0009] These and other objects and advantages of the present disclosure can be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. In addition, it will be easily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the attached claims and their combinations.

[0010] Technical Solution

[0011] According to one aspect of the present disclosure, an apparatus for diagnosing a battery may include: a storage unit configured to store library information about a voltage and a capacity of each of a plurality of battery libraries included in a battery module; and a control unit configured to generate a differential profile for each of the plurality of battery libraries based on the library information, determine a target peak in each of the plurality of generated differential profiles, and diagnose a state of the corresponding battery library based on the determined target peak.

[0012] The control unit may be configured to generate a differential profile indicating a correspondence relationship between a voltage and a differential capacity of each of the plurality of battery banks, and determine a target peak included in a preset standard voltage section in each of the generated plurality of differential profiles.

[0013] The control unit may be configured to diagnose a state of a battery bank in which the number of determined target peaks is less than or equal to the number of standard peaks included in a standard voltage section of a preset standard differential profile as a normal state.

[0014] The control unit may be configured to diagnose a state of the battery bank in which the number of the determined target peaks exceeds the number of the standard peaks as an abnormal state.

[0015] A standard differential profile may be preset to show the corresponding relationship between the voltage and the differential capacity of a standard battery bank.

[0016] The control unit may be configured to diagnose the state of the corresponding battery bank as an abnormal state when the determined number of target peaks exceeds the number of standard peaks and a voltage difference between the target peaks is greater than or equal to a preset threshold voltage.

[0017] The control unit may be configured to generate a differential profile indicating a correspondence between a capacity and a differential voltage of each of the plurality of battery banks based on the bank information, and determine a target peak included in a preset standard capacity section in each of the generated plurality of differential profiles.

[0018] The control unit may be configured to diagnose a state of a battery bank in which the number of determined target peaks is less than or equal to the number of standard peaks included in a standard capacity section of a preset standard differential profile as a normal state.

[0019] The control unit may be configured to diagnose a state of the battery bank in which the number of the determined target peaks exceeds the number of the standard peaks as an abnormal state.

[0020] A standard differential profile may be preset to show the corresponding relationship between the capacity of a standard battery library and the differential voltage.

[0021] The control unit may be configured to diagnose the state of the corresponding battery bank as an abnormal state when the number of the determined target peaks exceeds the number of the standard peaks and the capacity difference between the target peaks is greater than or equal to a preset threshold.

[0022] The control unit may be configured to calculate an abnormality ratio indicating a ratio of abnormal states among the plurality of battery banks, and diagnose a state of the battery module as a normal state or an abnormal state based on the abnormality ratio.

[0023] When the abnormality ratio is less than a preset threshold ratio, the control unit may be configured to diagnose the state of the battery module as a normal state.

[0024] When the abnormality ratio is greater than or equal to a threshold ratio, the control unit may be configured to diagnose the state of the battery module as an abnormal state.

[0025] The control unit may be configured to change a charging condition preset for the battery module when the state of the battery module is diagnosed as an abnormal state.

[0026] The control unit may be configured to, when the state of the battery module is diagnosed as an abnormal state, alleviate the fast charging condition of the battery module by reducing a maximum charging C-rate preset for the battery module.

[0027] The control unit can be configured to select a standard capacity in which the corresponding differential voltage in a reference differential profile preset for a standard battery library is the minimum, select a standard voltage corresponding to the standard capacity in a standard library profile preset for the standard battery library, and set a voltage segment that is less than or equal to the standard voltage as a standard voltage segment.

[0028] The reference differential profile may be preset to represent the corresponding relationship between the capacity and the differential voltage of the standard battery library.

[0029] The standard library profile may be preset to represent the corresponding relationship between the voltage and capacity of the standard battery library.

[0030] The control unit may be configured to select a standard capacity in which a corresponding differential voltage in a preset standard differential profile is minimum, and set a capacity section less than or equal to the standard capacity as the standard capacity section.

[0031] A battery pack according to another aspect of the present disclosure may include the apparatus for diagnosing a battery according to one aspect of the present disclosure.

[0032] According to another aspect of the present invention, a method for diagnosing a battery may include: a storage step, which stores library information about the voltage and capacity of each of a plurality of battery libraries included in a battery module; a differential profile generating step, which generates a differential profile for each of the plurality of battery libraries based on the library information; a target peak determining step, which determines a target peak in each of the generated plurality of differential profiles; and a diagnosis step, which diagnoses the state of the corresponding battery library based on the determined target peak.

[0033] Beneficial effects

[0034] According to one aspect of the present disclosure, an apparatus for diagnosing a battery has an advantage of accurately diagnosing a state of a battery bank and / or a battery module by considering unbalanced degradation of a plurality of battery cells.

[0035] The effects of the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the aforementioned disclosure, are used to provide a further understanding of the technical features of the present disclosure, and therefore, the present disclosure should not be construed as being limited to the accompanying drawings.

[0037] Figure 1 is a diagram schematically illustrating an apparatus for diagnosing a battery according to an embodiment of the present disclosure.

[0038] Figure 2 is a diagram schematically showing an exemplary configuration of a battery library and a battery module according to an embodiment of the present disclosure.

[0039] Figure 3 is a diagram schematically showing a differential section line according to an embodiment of the present disclosure.

[0040] Figure 4 is a diagram schematically showing a standard differential section line according to an embodiment of the present disclosure.

[0041] Figure 5 is a diagram schematically showing a reference differential section line according to an embodiment of the present disclosure.

[0042] Figure 6 is a diagram schematically showing a differential section line according to an embodiment of the present disclosure.

[0043] Figure 7 is a diagram schematically showing a standard differential section line according to an embodiment of the present disclosure.

[0044] Figure 8 is a diagram schematically showing an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0045] Fig. 9 is a diagram schematically illustrating a method for diagnosing a battery according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0046] It should be understood that the terms used in this specification and the appended claims should not be interpreted as limited to general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle allowing the inventor to appropriately define the terms to achieve the best interpretation.

[0047] Therefore, the descriptions presented herein are only preferred examples for illustrative purposes, and are not intended to limit the scope of the present disclosure, and it should be appreciated that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0048] Furthermore, in describing the present disclosure, when it is considered that the detailed description of related known elements or functions makes the key subject matter of the present disclosure unclear, the detailed description is omitted herein.

[0049] Terms including ordinal numbers such as “first,” “second,” etc. may be used to distinguish one element from another among various elements, but are not intended to limit the elements by the terms.

[0050] Throughout the specification, when a part is referred to as “comprising” or “including” any element, unless explicitly stated otherwise, it means that the part can further include other elements while not excluding other elements.

[0051] Furthermore, throughout the specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” with another element interposed therebetween.

[0052] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0053] Figure 1 is a diagram schematically illustrating an apparatus 100 for diagnosing a battery according to an embodiment of the present disclosure.

[0054] refer to Figure 1 , the apparatus 100 for diagnosing a battery according to an embodiment of the present disclosure may include a storage unit 110 and a control unit 120 .

[0055] The storage unit 110 may be configured to store bank information regarding a voltage and a capacity of each of a plurality of battery banks included in the battery module.

[0056] Figure 2 is a diagram schematically showing an exemplary configuration of a battery bank BB and a battery module BM according to an embodiment of the present disclosure.

[0057] exist Figure 2 In the embodiment of the present invention, a plurality of battery cells BC may be connected in parallel. A battery bank BB may include a plurality of battery cells BC connected in parallel. In addition, a plurality of battery banks BB may be connected in series. A battery module BM may include a plurality of battery banks BB connected in series. Figure 2 According to an embodiment of the present invention, a connection configuration of a battery cell BC, a battery bank BB, and a battery module BM will be described.

[0058] Here, a battery cell refers to an individual unit having a negative terminal and a positive terminal and being physically separable. As an example, a lithium-ion battery or a lithium-polymer battery can be regarded as a battery cell.

[0059] The storage unit 110 may store a battery library profile representing the correspondence between the voltage and the capacity of each of the plurality of battery libraries. For example, if the X-axis is set to the capacity and the Y-axis is set to the voltage, the battery library profile may be expressed as an XY graph. In addition, when the voltage is expressed as "V" and the capacity is expressed as "Q", the battery library profile may be expressed as a "QV profile". That is, the storage unit 110 may store library information, which is information representing the correspondence between the voltage and the capacity of each of the plurality of battery libraries.

[0060] The control unit 120 may be configured to generate a differential profile for each of the plurality of battery banks based on the battery bank information.

[0061] Specifically, the control unit 120 may generate at least one of a differential profile DP1 indicating a correspondence relationship between voltage and differential capacity and a differential profile DP2 indicating a correspondence relationship between capacity and differential voltage based on library information stored in the storage unit 110 .

[0062] In addition, the control unit 120 may diagnose the state of the battery module based on the generated differential profile.

[0063] Below, an embodiment will first be described in which the control unit 120 generates a differential profile DP1 representing the corresponding relationship between the voltage and the differential capacity and diagnoses the state of the battery bank based on the differential profile DP1. In addition, an embodiment will be described later in which the control unit 120 generates a differential profile DP2 and diagnoses the state of the battery bank based on the differential profile DP2.

[0064] Here, the differential capacity may refer to the rate of change of capacity relative to voltage. For example, when the voltage is expressed as "V" and the capacity is expressed as "Q", the differential capacity may be expressed as "dQ / dV".

[0065] The control unit 120 can generate a differential profile DP1 representing the corresponding relationship between the voltage and the differential capacity based on the library information stored in the storage unit 110. For example, if the X-axis is set to the voltage and the Y-axis is set to the differential capacity, the differential profile DP1 can be expressed as an XY curve graph. In addition, when the voltage is expressed as "V" and the differential capacity is expressed as "dQ / dV", the differential profile DP1 can be expressed as a "V-dQ / dV profile". Here, the differential capacity can refer to the rate of change of the capacity relative to the voltage. For example, when the voltage is expressed as "V" and the capacity is expressed as "Q", the differential capacity can be expressed as "dQ / dV".

[0066] Figure 3 Schematically illustrates a differential profile DP1 according to an embodiment of the present disclosure. Specifically, Figure 3 The embodiment of FIG. 1 is a diagram showing a differential profile DP1 for one of a plurality of battery banks included in a battery module. Figure 3 In the embodiment of the present invention, the voltage range of the battery bank may be 3.4 [V] to 4.2 [V].

[0067] The control unit 120 may be configured to determine a target peak tp included in a preset standard voltage section RV in each of the generated plurality of differential profile lines DP1 .

[0068] Specifically, the target peak tp may refer to a peak belonging to a preset standard voltage section RV among a plurality of peaks included in a plurality of differential profiles DP1. Here, the peak may be a point where the rate of change of the differential capacity relative to the voltage is 0 and has an upwardly convex shape. Specifically, the slope of the differential profile DP1 may change from positive to negative based on the peak.

[0069] For example, in Figure 3In the embodiment, it is assumed that the standard voltage section RV is preset to 3.4 [V] to 3.6 [V]. The differential profile line DP1 may include multiple peaks p1, p2, p3, p4, p5. Here, the voltage corresponding to the first peak p1 may be 3.45 [V], and the voltage corresponding to the second peak p2 may be 3.5 [V]. That is, only the first peak p1 and the second peak p2 may belong to the standard voltage section RV, while the third peak p3, the fourth peak p4 and the fifth peak p5 may not belong to the standard voltage section RV. Therefore, the control unit 120 may determine the first peak p1 and the second peak p2 as the target peak tp. Preferably, the control unit 120 may determine the first peak p1 as the first target peak tp1, and determine the second peak p2 as the second target peak tp2.

[0070] The control unit 120 may be configured to diagnose a state of the corresponding battery bank based on the determined target peak tp.

[0071] Specifically, the control unit 120 may be configured to diagnose the state of the battery bank as a normal state or an abnormal state based on the number of the determined target peaks tp. Preferably, the control unit 120 may compare the number of the target peaks tp with the number of standard peaks rp of a preset standard differential profile RP1, and diagnose the state of the battery bank according to the comparison result.

[0072] Here, the standard differential profile RP1 may be preset to represent the corresponding relationship between the voltage and differential capacity of the standard battery bank. That is, the control unit 120 may compare the number of target peaks tp included in the standard voltage section RV of the differential profile DP1 with the number of standard peaks rp included in the standard voltage section RV of the standard differential profile RP1.

[0073] For example, the standard battery library may be a test library designed to generate a standard differential profile RP1 or a battery library in a BOL (beginning of life) state. Preferably, a standard battery library is set for each of the plurality of battery libraries, and the battery library in a BOL state may be set as the standard battery library. That is, for each of the plurality of battery libraries, the differential profile of the battery library in a BOL state (standard battery library) may be set as the standard differential profile RP1 of the battery library.

[0074] Figure 4 is a diagram schematically showing a standard differential profile RP1 according to an embodiment of the present disclosure.

[0075] Specifically, Figure 4 The embodiment of FIG. 1 is a diagram showing a standard differential profile RP1 for a standard battery library. Figure 4 In the embodiment of the present invention, the voltage range of the standard battery bank may be 3.4 [V] to 4.2 [V].

[0076] Preferably, according to Figure 4 The standard battery library of the embodiment may correspond to Figure 3 For example, according to the battery bank of the embodiment of Figure 4 The standard differential profile RP1 of the embodiment can be for Figure 3 The differential profile DP1 of the BOL state of the battery bank of the embodiment. The standard voltage section RV of the standard differential profile RP1 may include a standard peak rp.

[0077] In one embodiment, the control unit 120 may diagnose the state of the battery bank in which the number of the determined target peaks tp is less than or equal to the number of standard peaks rp included in the standard voltage section RV of the preset standard differential profile RP1 as a normal state. Conversely, the control unit 120 may diagnose the state of the battery bank in which the number of the determined target peaks tp exceeds the number of standard peaks rp as an abnormal state.

[0078] If the number of target peaks tp exceeds the number of standard peaks rp, it can be seen that unbalanced degradation of the plurality of battery cells included in the battery library has occurred.

[0079] In the BOL state, the states of multiple battery cells may be substantially the same. However, if multiple battery cells degrade unbalancedly while the battery pool is being operated, the number of target peaks tp may exceed the number of standard peaks rp. On the contrary, even if the battery pool is being operated, if multiple battery cells degrade in a balanced manner, the number of target peaks tp may be less than or equal to the number of standard peaks rp. This is because the state differences of multiple battery cells due to unbalanced degradation appear as an increased number of target peaks tp in the differential profile DP1 for the battery pool. Therefore, the control unit 120 can diagnose the state of the battery pool as a normal state or an abnormal state based on the result of comparing the determined number of target peaks tp with the preset number of standard peaks rp.

[0080] For example, in Figure 3 In the embodiment of the present invention, the differential profile DP1 may include a first target peak tp1 and a second target peak tp2. Figure 4 In the embodiment of FIG. 1 , the standard differential profile RP1 may include one standard peak rp. Since the number of target peaks tp exceeds the number of standard peaks rp, the control unit 120 may diagnose the state of the battery bank as an abnormal state.

[0081] The apparatus 100 for diagnosing a battery has an advantage of accurately diagnosing the state of a battery bank based on the number of target peaks tp, which reflects unbalanced degradation of a plurality of battery cells.

[0082] In another embodiment, the control unit 120 may be configured to diagnose the state of the corresponding battery bank as an abnormal state when the number of determined target peaks tp exceeds the number of standard peaks rp and the voltage difference between the target peaks tp is greater than or equal to a preset threshold voltage.

[0083] The control unit 120 diagnoses the state of the battery bank by considering not only the number of target peaks tp but also the voltage difference between the target peaks tp. As previously explained, if state differences occur among a plurality of battery cells, the number of target peaks tp may exceed the number of standard peaks rp.

[0084] When the number of target peaks tp exceeds the number of standard peaks rp, the control unit 120 may calculate the voltage difference between the target peaks tp. In addition, the control unit 120 may compare a preset threshold voltage with the calculated voltage difference. Here, the threshold voltage may be preset to indicate that the degree of unbalanced deterioration between the plurality of battery cells is severe enough to determine the state of the battery bank as an abnormal state. For example, the threshold voltage may be preset to a value of 0.01 [V] or higher. Preferably, the threshold voltage may be preset to 0.02 [V].

[0085] For example, in Figure 3 In the embodiment of the present invention, the voltage of the first target peak tp1 may be 3.45 [V], and the voltage of the second target peak tp2 may be 3.5 [V]. The control unit 120 may calculate the voltage difference between the first target peak tp1 and the second target peak tp2 as 0.5 [V]. Because the calculated voltage difference (0.5 [V]) is greater than or equal to the preset threshold voltage (0.02 [V]), the control unit 120 may diagnose the state of the battery bank as an abnormal state.

[0086] The apparatus 100 for diagnosing a battery has an advantage of more accurately diagnosing the state of a battery bank based on the number of target peaks tp and the voltage difference between the target peaks tp.

[0087] In the following, reference Figures 3 to 5 , a standard voltage section RV from which the standard peak rp and the target peak tp can be determined will be described.

[0088] The control unit 120 may be configured to select a standard capacity in which a corresponding differential voltage in a reference differential profile RP2 preset for the standard battery library is minimum.

[0089] Here, the reference differential profile RP2 may be preset to represent the corresponding relationship between the capacity and the differential voltage of the standard battery library. In addition, the differential voltage may represent the rate of change of the voltage relative to the capacity. For example, when the voltage is expressed as "V" and the capacity is expressed as "Q", the differential voltage may be expressed as "dV / dQ".

[0090] Figure 5 Schematically illustrates a reference differential profile RP2 according to an embodiment of the present disclosure. Figure 5 In the embodiment of , the capacity is a capacity normalized to a range of 0 to 1. Figure 5 In the embodiment of the present invention, when the X-axis is set to capacity and the Y-axis is set to differential voltage, the reference differential profile RP2 can be expressed as an XY curve graph. In addition, when the capacity is expressed as "Q" and the differential voltage is expressed as "dV / dQ", the reference differential profile RP2 can be expressed as a "Q-dV / dQ profile".

[0091] exist Figure 5 In the embodiment of the invention, the control unit 120 may select a point (min) where the differential voltage is the minimum in the reference differential profile RP2. Here, the capacity corresponding to the point (min) may be 0.3. Therefore, the control unit 120 may select the standard capacity as 0.3.

[0092] The control unit 120 may be configured to select a standard voltage corresponding to a standard capacity in a standard library profile preset for a standard battery library.

[0093] Here, the standard library profile may be preset to represent the corresponding relationship between the voltage and capacity of the standard battery library. For example, the standard library profile may be a profile in which the corresponding voltage and capacity of the standard battery are mapped.

[0094] The control unit 120 may use the standard library profile to select a standard voltage corresponding to the standard capacity. For example, the standard voltage selected by the control unit 120 may be 3.6 [V].

[0095] The control unit 120 may be configured to set a voltage section that is less than or equal to a standard voltage as the standard voltage section RV.

[0096] For example, in Figure 3 In the embodiment of the present invention, the control unit 120 may set the voltage section of 3.6 [V] or lower as the standard voltage section RV. Specifically, because the voltage section of the battery bank is 3.4 [V] to 4.2 [V], the control unit 120 may set the voltage section of 3.4 [V] to 3.6 [V] as the standard voltage section RV.

[0097] The device 100 for diagnosing a battery can determine the peak included in the standard voltage section RV as the target peak tp, so as to diagnose the state of the battery library based on the unbalanced degradation of the negative electrode of the battery cell. That is, the standard voltage section RV can be a voltage section that reflects the degradation state of the negative electrode. In addition, this degradation state of the negative electrode can be clearly seen in the differential profile DP1. Therefore, the device 100 for diagnosing a battery can diagnose the state of the battery library based on whether the multiple battery cells included in the battery library have undergone unbalanced deterioration of the negative electrode.

[0098] Next, an embodiment will be described in which the control unit 120 generates a differential profile DP2 indicating a correspondence relationship between the capacity and the differential voltage and diagnoses the state of the battery bank based on the differential profile DP2.

[0099] Here, the differential voltage may represent a rate of change of voltage relative to capacity. For example, when the voltage is expressed as "V" and the capacity is expressed as "Q", the differential voltage may be expressed as "dV / dQ".

[0100] The control unit 120 may generate a differential profile DP2 representing the corresponding relationship between the capacity and the differential voltage based on the library information stored in the storage unit 110. For example, if the X-axis is set to the capacity and the Y-axis is set to the differential voltage, the differential profile DP2 may be expressed as an XY graph. In addition, when the capacity is expressed as "Q" and the differential voltage is expressed as "dV / dQ", the differential profile DP2 may be expressed as a "Q-dV / dQ profile".

[0101] Figure 6 is a diagram schematically showing a differential profile line DP2 according to an embodiment of the present disclosure.

[0102] Specifically, Figure 6 The embodiment of FIG. 1 is a diagram showing a differential profile DP2 for one of a plurality of battery banks included in a battery module. Figure 6 In the embodiment of the present invention, the capacity range of the battery bank can be normalized to 0 to 1. Please note that the normalization of the capacity is for the convenience of explanation, and the capacity normalization process can be omitted.

[0103] The control unit 120 may be configured to determine a target peak tp included in a preset standard capacity section RQ in each of the generated plurality of differential profiles DP2 .

[0104] Specifically, the target peak tp may refer to a peak belonging to a preset standard capacity section RQ among the multiple peaks included in the multiple differential profiles DP2. Here, the peak may be a point where the rate of change of the differential voltage relative to the capacity is 0 and has an upwardly convex shape. Specifically, the slope of the differential profile DP2 may change from positive to negative based on the peak.

[0105] For example, in Figure 6 In the embodiment of , it is assumed that the standard capacity section RQ is preset to 0 to 0.3. The differential profile DP2 may include multiple peaks p1, p2, p3, p4. Here, only the first peak p1 and the second peak p2 may belong to the standard capacity section RQ, while the third peak p3 and the fourth peak p4 may not belong to the standard capacity section RQ. Therefore, the control unit 120 may determine the first peak p1 and the second peak p2 as the target peak tp. Preferably, the control unit 120 may determine the first peak p1 as the first target peak tp1, and determine the second peak p2 as the second target peak tp2.

[0106] The control unit 120 may be configured to diagnose a state of the corresponding battery bank based on the determined target peak tp.

[0107] Specifically, the control unit 120 may be configured to diagnose the state of the battery bank as a normal state or an abnormal state based on the number of the determined target peaks tp. Preferably, the control unit 120 may compare the number of the target peaks tp with the number of standard peaks rp of a preset standard differential profile RP, and diagnose the state of the battery bank according to the comparison result.

[0108] Here, the standard differential profile RP may be preset to represent the corresponding relationship between the capacity of the standard battery bank and the differential voltage. That is, the control unit 120 may compare the number of target peaks tp included in the standard capacity segment RQ of the differential profile DP2 with the number of standard peaks rp included in the standard capacity segment RQ of the standard differential profile RP.

[0109] For example, the standard battery library may be a test library designed to generate a standard differential profile RP or a battery library in a BOL state. Preferably, a standard battery library is set for each of the plurality of battery libraries, and the battery library in the BOL state may be set as a standard battery library. That is, for each of the plurality of battery libraries, the differential profile DP2 of the battery library in the BOL state (standard battery library) may be set as the standard differential profile RP of the battery library.

[0110] Figure 7 is a diagram schematically showing a standard differential section line according to an embodiment of the present disclosure.

[0111] Specifically, Figure 7 The embodiment of FIG. 1 is a diagram showing a standard differential profile RP for a standard battery library. Figure 7 In the embodiment of the present invention, the capacity range of the standard battery library can be normalized to 0 to 1. As explained previously, the normalization of the capacity is for the convenience of explanation.

[0112] Preferably, according to Figure 7 The standard battery library of the embodiment may correspond to Figure 6 For example, according to the battery bank of the embodiment of Figure 7 The standard differential profile RP of an embodiment may be based on Figure 6 The differential profile DP2 for the BOL state of the battery bank of the embodiment of the present invention. The standard capacity section RQ of the standard differential profile RP may include a standard peak rp.

[0113] In one embodiment, the control unit 120 may diagnose the state of the battery bank in which the number of determined target peaks tp is less than or equal to the number of standard peaks rp included in the standard capacity section RQ of the preset standard differential profile RP as a normal state. Conversely, the control unit 120 may diagnose the state of the battery bank in which the number of determined target peaks tp exceeds the number of standard peaks rp as an abnormal state.

[0114] If the number of target peaks tp exceeds the number of standard peaks rp, it can be seen that unbalanced degradation has occurred in a plurality of battery cells included in the battery library.

[0115] In the BOL state, the states of multiple battery cells may be basically the same. However, if multiple battery cells deteriorate unbalancedly when the battery library is operated, the number of target peaks tp may exceed the number of standard peaks rp. On the contrary, even if the battery library is operated, if multiple battery cells deteriorate in a balanced manner, the number of target peaks tp may be less than or equal to the number of standard peaks rp. This is because the state differences of multiple battery cells due to unbalanced degradation appear as an increased number of target peaks tp in the differential profile DP2 for the battery library. Therefore, the control unit 120 can diagnose the state of the battery library as a normal state or an abnormal state based on the comparison result of the determined number of target peaks tp and the preset number of standard peaks rp.

[0116] For example, in Figure 6 In the embodiment of the present invention, the differential profile DP2 may include a first target peak tp1 and a second target peak tp2. Figure 7 In the embodiment of FIG. 1 , the standard differential profile RP may include one standard peak rp. Since the number of target peaks tp exceeds the number of standard peaks rp, the control unit 120 may diagnose the state of the battery bank as an abnormal state.

[0117] The apparatus 100 for diagnosing a battery has an advantage of accurately diagnosing the state of a battery bank based on the number of target peaks tp, which reflects unbalanced degradation of a plurality of battery cells.

[0118] In another embodiment, the control unit 120 may be configured to diagnose the state of the corresponding battery bank as an abnormal state when the number of determined target peaks tp exceeds the number of standard peaks rp and the capacity difference between the target peaks tp is greater than or equal to a preset threshold.

[0119] The control unit 120 can diagnose the state of the battery bank by considering not only the number of target peaks tp but also the capacity difference between the target peaks tp. As explained previously, if state differences occur among a plurality of battery cells, the number of target peaks tp may exceed the number of standard peaks rp.

[0120] When the number of target peaks tp exceeds the number of standard peaks rp, the control unit 120 may calculate the capacity difference between the target peaks tp. In addition, the control unit 120 may compare a preset threshold with the calculated capacity difference. Here, the threshold may be preset to indicate that the degree of deterioration of the imbalance between the plurality of battery cells is severe enough to determine the state of the battery bank as an abnormal state. For example, the threshold may be preset to 3%. When the capacity difference between the target peaks tp is greater than or equal to a preset threshold (3%), the control unit 120 may diagnose the state of the battery bank as an abnormal state. In one embodiment, the control unit 120 may calculate the capacity difference between the target peaks by calculating the formula "(capacity of the second target peak - capacity of the first target peak) ÷ capacity of the first target peak × 100". In addition, the control unit 120 may compare the calculated capacity difference with a threshold.

[0121] The apparatus 100 for diagnosing a battery has an advantage of more accurately diagnosing the state of the battery bank based on the number of target peaks tp and the capacity difference between the target peaks tp.

[0122] In the following, reference will be made to Figure 6 and 7 A standard volume section RQ is described from which the standard peak rp and the target peak tp can be determined.

[0123] The control unit 120 may be configured to select a standard capacity in which a corresponding differential voltage in a standard differential profile RP preset for the standard battery library is minimum.

[0124] Here, the standard differential profile RP may be preset to represent the corresponding relationship between the capacity and the differential voltage of the standard battery bank. In addition, the differential voltage may represent the rate of change of the voltage relative to the capacity. For example, when the voltage is expressed as "V" and the capacity is expressed as "Q", the differential voltage may be expressed as "dV / dQ".

[0125] exist Figure 7 In the embodiment of the invention, the control unit 120 may select a point (min) where the differential voltage is the minimum in the standard differential profile RP. Here, the capacity corresponding to the point (min) may be 0.3. Therefore, the control unit 120 may select the standard capacity as 0.3.

[0126] The control unit 120 may be configured to set a capacity section that is less than or equal to the standard capacity as the standard capacity section RQ.

[0127] For example, in Figure 6 In the embodiment of the present invention, the control unit 120 may set a capacity segment of 0.3 or less as the standard capacity segment RQ. Specifically, because the capacity segment of the battery bank is 0 to 1, the control unit 120 may set a capacity segment of 0 to 0.3 as the standard capacity segment RQ. Here, please note that the capacity segment of 0 to 0.3 is a normalized capacity segment for the actual capacity segment of the battery bank.

[0128] The device 100 for diagnosing a battery can determine the peak included in the standard capacity section RQ as the target peak tp, so as to diagnose the state of the battery library based on the unbalanced degradation of the negative electrode of the battery cell. That is, the standard capacity section RQ can be a capacity section that reflects the degradation state of the negative electrode. In addition, this degradation state of the negative electrode can be clearly seen in the differential profile DP2. Therefore, the device 100 for diagnosing can diagnose the state of the battery library based on whether unbalanced degradation of the negative electrode has occurred in the multiple battery cells included in the battery library.

[0129] Meanwhile, the control unit 120 included in the apparatus 100 for diagnosing a battery may optionally 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 executed in the present disclosure. In addition, when the control logic is implemented as software, the control unit 120 may be implemented as a collection of program modules. At this time, the program modules may be stored in a 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.

[0130] Here, the storage unit 110 may store data necessary for the operation and function of each component of the device 100 for diagnosing a battery, data generated in the process of performing an operation or function, etc. The type of the storage unit 110 is not particularly limited as long as it is a known information storage device capable of recording, erasing, updating, and reading data. As an example, the information storage device may include a RAM, a flash memory, a ROM, an EEPROM, a register, etc. In addition, the storage unit 110 may store a program code in which a process executable by the control unit 120 is defined.

[0131] Hereinafter, an embodiment in which the control unit 120 diagnoses the state of the battery module will be described in detail.

[0132] The control unit 120 may be configured to calculate an abnormality ratio indicating a ratio of abnormal states among the plurality of battery banks.

[0133] Specifically, the control unit 120 may calculate a ratio of the number of battery banks diagnosed as being in an abnormal state to the number of the plurality of battery banks.

[0134] In one embodiment, it is assumed that the number of the plurality of battery banks included in the battery module is N, and the number of the battery banks diagnosed as being in an abnormal state is M. The control unit 120 may calculate the abnormality ratio by a calculation formula “M÷N” or “M÷N×100”. The formula for calculating the abnormality ratio may be appropriately selected depending on the unit of the abnormality ratio to be calculated.

[0135] The control unit 120 may be configured to diagnose the state of the battery module as a normal state or an abnormal state based on the abnormality ratio.

[0136] For example, if the abnormality ratio is less than a preset threshold ratio, the control unit 120 may diagnose the state of the battery module as a normal state. Conversely, if the abnormality ratio is greater than or equal to the threshold ratio, the control unit 120 may diagnose the state of the battery module as an abnormal state.

[0137] The apparatus 100 for diagnosing a battery may further diagnose the state of the battery module based on the states of the plurality of battery banks. In other words, the apparatus 100 for diagnosing a battery may diagnose the state of the battery module as well as the state of each of the plurality of battery banks.

[0138] The control unit 120 may be configured to change a charging condition preset for the battery module when the state of the battery module is diagnosed as an abnormal state.

[0139] Specifically, when the state of the battery module is diagnosed as an abnormal state, the control unit 120 may be configured to alleviate the fast charging condition of the battery module by reducing the maximum charging C rate preset for the battery module.

[0140] Here, the fast charging condition refers to a charging C-rate (current rate) condition that can be applied to the battery module.

[0141] If the battery module diagnosed as being in an abnormal state continues to be fast charged, a lithium plating (Li plating) phenomenon in which lithium metal is precipitated on the negative electrode surface of the battery cell may occur, and the degradation of the battery cell may be accelerated. Therefore, the control unit 120 may ease the fast charging condition to increase the life of the battery module.

[0142] exist Figure 3In an embodiment, when the control unit 120 diagnoses the state of the battery bank based on the differential profile line DP1, the control unit 120 may be configured to reduce the maximum charge C rate set for the remaining voltage sections excluding the standard voltage section RV among all voltage sections of the battery module.

[0143] exist Figure 6 In an embodiment, when the control unit 120 diagnoses the state of the battery library based on the differential profile line DP2, the control unit 120 may be configured to reduce the maximum charging C rate set for the remaining capacity segments excluding the standard capacity segment RQ among all capacity segments of the battery module.

[0144] For example, when the battery module is fully discharged, it is assumed that the fast charging condition for the battery module is set to 2C in order to fully charge the battery module within 30 minutes. In other words, it is assumed that the maximum charge C rate for the battery module is set to 2C. If the state of the battery module is diagnosed as an abnormal state, the control unit 120 may reduce the maximum charge C rate set in the battery module from 2C to 1C.

[0145] The apparatus 100 for diagnosing a battery can prevent the battery module diagnosed as being in an abnormal state from accelerating deterioration by reducing the maximum charge C rate set for the battery module. In addition, by reducing the maximum charge C rate, the precipitation of lithium metal due to rapid charging can be prevented. Therefore, the occurrence of various problems due to the lithium plating phenomenon can be prevented in advance.

[0146] The apparatus 100 for diagnosing a battery according to the present disclosure may be applied to a battery management system (BMS). That is, the BMS according to the present disclosure may include the above-mentioned apparatus 100 for diagnosing a battery. In this configuration, at least some components of the apparatus 100 for diagnosing a battery may be implemented by supplementing or adding functions of components included in a conventional BMS. For example, the storage unit 110 and the control unit 120 of the apparatus 100 for diagnosing a battery may be implemented as components of the BMS.

[0147] In addition, the device 100 for diagnosing a battery according to the present disclosure may be provided in a battery pack. That is, the battery pack according to the present disclosure may include the above-mentioned device 100 for diagnosing a battery and at least one battery cell. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a housing.

[0148] Figure 8 is a diagram schematically showing an exemplary configuration of a battery pack 1 according to another embodiment of the present disclosure.

[0149] The battery module 10 may include a plurality of battery banks 11, 12, 13. Figure 8In the embodiment, a plurality of battery banks 11, 12, 13 may be connected in series with each other.

[0150] The measuring unit 20 may measure the voltage of each of the plurality of battery banks 11, 12, 13. In addition, the measuring unit 20 may measure the voltage of the battery module 10.

[0151] In addition, the measuring unit 20 may be connected to the current measuring unit A. For example, the current measuring unit A may be an ammeter or a shunt resistor, which is capable of measuring the charging current and the discharging current of the battery module 10. The measuring unit 20 may calculate the charging amount by measuring the charging current of the battery module 10 by the current measuring unit A. In addition, the measuring unit 20 may calculate the discharging amount by measuring the discharging current of the battery module 10 by the current measuring unit A.

[0152] An external device may be connected to the positive terminal P+ and the negative terminal P− of the battery pack 1. For example, the external device may be a charging / discharging device or a motor of an electric vehicle that receives power from the battery pack 1.

[0153] Fig. 9 is a diagram schematically illustrating a method for diagnosing a battery according to yet another embodiment of the present disclosure.

[0154] Preferably, each step of the method for diagnosing a battery may be performed by the apparatus for diagnosing a battery 100. Hereinafter, for the convenience of explanation, contents overlapping with the previously described contents will be briefly described or omitted.

[0155] The storing step ( S100 ) is a step of storing bank information regarding a voltage and a capacity of each of a plurality of battery banks included in the battery module, and may be performed by the storage unit 110 .

[0156] For example, the storage unit 110 may store a battery bank profile indicating a corresponding relationship between a voltage and a capacity of each of a plurality of battery banks.

[0157] The differential section line generating step ( S200 ) is a step of generating a differential section line for each of the plurality of battery libraries based on the library information, and may be performed by the control unit 120 .

[0158] For example, in Figure 3 In the embodiment of the present invention, the control unit 120 may generate a differential profile DP1 indicating a corresponding relationship between a voltage and a differential capacity based on the library information stored in the storage unit 110 .

[0159] As another example, in Figure 6 In the embodiment of the present invention, the control unit 120 may generate a differential profile DP2 indicating a corresponding relationship between the capacity and the differential voltage based on the library information stored in the storage unit 110.

[0160] The target peak determination step ( S300 ) is a step of determining a target peak tp in each of the generated plurality of differential profiles, and may be performed by the control unit 120 .

[0161] For example, in Figure 3 In the embodiment, it is assumed that the standard voltage section RV is preset to 3.4 [V] to 3.6 [V]. The control unit 120 may determine the first peak p1 as the first target peak tp1 and the second peak p2 as the second target peak tp2 among the plurality of peaks p1, p2, p3, p4, p5 included in the differential profile line DP1.

[0162] For example, in Figure 6 In the embodiment of , it is assumed that the standard capacity section RQ is preset to 0 to 0.3. The control unit 120 may determine the first peak p1 as the first target peak tp1 and the second peak p2 as the second target peak tp2 among the plurality of peaks p1, p2, p3, p4 included in the differential profile DP2.

[0163] The diagnosis step ( S400 ) is a step of diagnosing the state of the corresponding battery bank based on the determined target peak tp, and may be performed by the control unit 120 .

[0164] exist Figures 3 to 5 In an embodiment, the control unit 120 may diagnose the state of a battery bank in which the number of determined target peaks tp is less than or equal to the number of standard peaks rp included in the standard voltage section RV of the preset standard differential profile RP1 as a normal state. Conversely, the control unit 120 may diagnose the state of a battery bank in which the number of determined target peaks tp exceeds the number of standard peaks rp as an abnormal state. In addition, the control unit 120 may be configured to diagnose the state of the corresponding battery bank as an abnormal state when the number of determined target peaks tp exceeds the number of standard peaks rp and the voltage difference between the target peaks tp is greater than or equal to a preset threshold voltage.

[0165] exist Figure 6 and Figure 7 In the embodiment of the present invention, the control unit 120 may diagnose the state of a battery pool in which the number of determined target peaks tp is less than or equal to the number of standard peaks rp included in the standard capacity section RQ of the preset standard differential profile RP as a normal state. On the contrary, the control unit 120 may diagnose the state of a battery pool in which the number of determined target peaks tp exceeds the number of standard peaks rp as an abnormal state. In addition, the control unit 120 may be configured to diagnose the state of the corresponding battery pool as an abnormal state when the number of determined target peaks tp exceeds the number of standard peaks rp and the capacity difference between the target peaks tp is greater than or equal to a preset threshold value.

[0166] The embodiments of the present disclosure described above may be implemented not only by devices and methods, but may be implemented by a program that implements functions corresponding to the configuration of the embodiments of the present disclosure or a recording medium on which the program is recorded. Based on the above description of the embodiments, those skilled in the art may easily implement the program or recording medium.

[0167] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

[0168] In addition, without departing from the technical aspects of the present disclosure, those skilled in the art may make many substitutions, modifications and changes to the present disclosure, and the present disclosure is not limited to the above-mentioned embodiments and drawings, and each embodiment may be selectively combined in part or as a whole to allow various modifications.

[0169] (Explanation of Reference Numerals)

[0170] 1: Battery Pack

[0171] 10: Battery module

[0172] 11, 12, 13: Battery Library

[0173] 20: Measurement unit

[0174] 100: Device for diagnosing batteries

[0175] 110: Storage unit

[0176] 120: Control unit

Claims

1. A device for diagnosing a battery, comprising: a storage unit configured to store bank information regarding a voltage and a capacity of each of a plurality of battery banks included in the battery module; as well as A control unit is configured to generate a differential profile for each of the plurality of battery libraries based on the library information, determine a target peak in each of the generated plurality of differential profiles, and diagnose a state of the corresponding battery library based on the determined target peak.

2. The device for diagnosing a battery according to claim 1, in, The control unit is configured to generate a differential profile indicating a correspondence relationship between the voltage and differential capacity of each of the plurality of battery banks, and determine the target peak included in a preset standard voltage section in each of the generated plurality of differential profiles.

3. The device for diagnosing a battery according to claim 2, in, The control unit is configured to diagnose a state of a battery bank in which the number of determined target peaks is less than or equal to the number of standard peaks included in the standard voltage section of a preset standard differential profile as a normal state, wherein the control unit is configured to diagnose a state of a battery bank in which the number of determined target peaks exceeds the number of standard peaks as an abnormal state, and The standard differential profile is preset to show the corresponding relationship between the voltage and the differential capacity of the standard battery library.

4. The device for diagnosing a battery according to claim 3, in, The control unit is configured to diagnose a state of a corresponding battery bank as an abnormal state when the number of the determined target peaks exceeds the number of the standard peaks and a voltage difference between the target peaks is greater than or equal to a preset threshold voltage.

5. The device for diagnosing a battery according to claim 1, in, The control unit is configured to generate a differential profile indicating a correspondence relationship between the capacity and a differential voltage of each of the plurality of battery banks based on the bank information, and determine a target peak included in a preset standard capacity section in each of the generated plurality of differential profiles.

6. The device for diagnosing a battery according to claim 5, in, The control unit is configured to diagnose a state of a battery bank in which the number of determined target peaks is less than or equal to the number of standard peaks included in the standard capacity section of a preset standard differential profile as a normal state, wherein the control unit is configured to diagnose a state of a battery bank in which the number of determined target peaks exceeds the number of standard peaks as an abnormal state, and The standard differential profile is preset to show the corresponding relationship between the capacity of the standard battery library and the differential voltage.

7. The device for diagnosing a battery according to claim 6, in, The control unit is configured to diagnose the state of the corresponding battery bank as an abnormal state when the number of the determined target peaks exceeds the number of the standard peaks and the capacity difference between the target peaks is greater than or equal to a preset threshold.

8. The device for diagnosing a battery according to claim 1, in, The control unit is configured to calculate an abnormality ratio indicating a ratio of abnormal states among the plurality of battery banks, and diagnose a state of the battery module as a normal state or an abnormal state based on the abnormality ratio.

9. The device for diagnosing a battery according to claim 8, in, When the abnormal ratio is less than a preset threshold ratio, the control unit is configured to diagnose the state of the battery module as the normal state, and When the abnormality ratio is greater than or equal to the threshold ratio, the control unit is configured to diagnose the state of the battery module as the abnormal state.

10. The device for diagnosing a battery according to claim 8, in, The control unit is configured to change a charging condition preset for the battery module when the state of the battery module is diagnosed as an abnormal state.

11. The device for diagnosing a battery according to claim 10, in, The control unit is configured to, when the state of the battery module is diagnosed as an abnormal state, alleviate a fast charging condition of the battery module by reducing a maximum charging C-rate preset for the battery module.

12. The device for diagnosing a battery according to claim 2, in, The control unit is configured to select a standard capacity in which the corresponding differential voltage in a reference differential section line preset for a standard battery library is the smallest, select a standard voltage corresponding to the standard capacity in a standard library section line preset for the standard battery library, and set a voltage section less than or equal to the standard voltage as the standard voltage section, The reference differential profile is preset to represent the corresponding relationship between the capacity of the standard battery library and the differential voltage, and The standard library profile is preset to represent the corresponding relationship between the voltage and the capacity of the standard battery library.

13. The device for diagnosing a battery according to claim 5, in, The control unit is configured to select a standard capacity in which a corresponding differential voltage in the standard differential profile is the smallest, and set a capacity section that is less than or equal to the standard capacity as the standard capacity section.

14. A battery pack comprising the device for diagnosing a battery according to any one of claims 1 to 13.

15. A method for diagnosing a battery, comprising: a storing step of storing library information on a voltage and a capacity of each of a plurality of battery libraries included in the battery module; a differential section line generating step of generating a differential section line for each of the plurality of battery libraries based on the library information; a target peak determining step of determining a target peak in each of the generated plurality of differential profiles; and A diagnosis step is performed to diagnose a state of a corresponding battery bank based on the determined target peak.

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