Device and method for diagnosing battery status, battery pack, and vehicle

Abstract

According to one embodiment of the present invention, a device for diagnosing the status of a battery includes: a curve acquisition unit, which is configured to acquire a voltage curve of the battery relative to the voltage and capacity of the battery; and a control unit, which is configured to acquire a differential curve relative to the voltage and capacity from the voltage curve acquired by the curve acquisition unit, select a plurality of peaks included in a predetermined voltage duration from the acquired differential curve, determine a first peak associated with the negative electrode and a second peak associated with the positive electrode among the selected plurality of peaks, compare the first peak and the second peak with the first reference peak and the second reference peak of a preset reference curve, respectively, and diagnose the status of the battery by considering the behavioral change of the first peak relative to the first reference peak and / or the behavioral change of the second peak relative to the second reference peak.

Description

Technical Field

[0001] This application claims priority from Korean Patent Application No. 10-2020-0058254 filed in Korea on May 15, 2020, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to an apparatus and method for diagnosing a state of a battery, and more particularly, to an apparatus and method for diagnosing a state of a battery by diagnosing degradation of the battery using real-time cycle data. Background Art

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

[0004] Currently available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among these batteries, lithium batteries have attracted much attention because they have almost no memory effect compared to nickel-based batteries and also have extremely low self-discharge rate and high energy density.

[0005] Batteries may degrade due to repeated charging or discharging. For example, at the positive electrode of a battery cell, the electrolyte may be oxidized or the crystal structure may be destroyed, causing the battery cell to degrade. At the negative electrode, metallic lithium may precipitate, causing the battery cell to degrade. In addition, generally speaking, depending on the manufacturing conditions of lithium-ion secondary batteries, the capacity degradation of secondary batteries may be accelerated. Therefore, conventionally, a technology for diagnosing battery cell degradation based on a difference curve between the voltage and capacity of the battery cell has been disclosed.

[0006] Figure 1 is a diagram schematically showing a voltage curve 10 according to the prior art.

[0007] Reference Figure 1 The voltage curve 10 is a curve showing the capacity Q and voltage of the battery cell. In the voltage curve 10, the battery curve 13 can be expressed as the difference between the positive electrode curve 11 and the negative electrode curve 12.

[0008] Figure 2 is a diagram schematically showing a differential curve 20 according to the prior art.

[0009] Reference Figure 2 , the differential curve 20 is a curve obtained by differentiating the capacity of the battery cell according to the voltage. Figure 2In the voltage curve 10 shown, battery degradation is diagnosed using at least one of the first peak 21, the second peak 22, the fourth peak 24, the fifth peak 25, and the sixth peak 26. For example, conventionally, the first peak 21 and / or the second peak 22 is used to diagnose degradation of the negative electrode of the battery, and at least one of the fourth peak 24, the fifth peak 25, and the sixth peak 26 is used to diagnose degradation of the positive electrode of the battery.

[0010] Meanwhile, third peak 23 of differential curve 20 is a mixture of the positive and negative peaks of the battery cell. In other words, conventional techniques suffer from the problem of being unable to specifically diagnose positive or negative electrode degradation of the battery based on third peak 23, a mixture of the positive and negative peaks. Therefore, conventional techniques use peaks other than third peak 23 among the multiple peaks included in differential curve 20 to diagnose positive or negative electrode degradation of the battery.

[0011] In addition, in the prior art, Figure 2 As shown, in order to obtain a differential curve 20 in which multiple peaks can be distinguished, there is a problem that the battery cell needs to be charged and / or discharged at a low rate. For example, a differential curve 20 can be obtained while charging the battery cell at 0.05C (C-rate). Figure 1 The voltage curve 10 and can be based on Figure 1 The differential curve 10 is obtained Figure 2 The differential curve 20.

[0012] That is, due to the limitation that each peak included in the differential curve 20 can be clearly expressed only when the battery cell is charged or discharged at a low rate, there is a problem in that the existing technology can be applied only in very limited cases such as a battery cell testing process. Summary of the Invention

[0013] Technical issues

[0014] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure aims to provide an apparatus and method for diagnosing the state of a battery, which can diagnose battery degradation by interpreting specific peaks included in a differential curve obtained through high-rate charging or high-rate discharging.

[0015] These and other objects and advantages of the present disclosure can be understood from the following detailed description and will become more apparent from the exemplary embodiments of the present disclosure. In addition, it will be readily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0016] Technical Solution

[0017] In one aspect of the present disclosure, a device for diagnosing a state of a battery is provided, the device comprising: a curve obtaining unit configured to obtain a voltage curve of the battery for the voltage and capacity of the battery; and a control unit configured to obtain a differential curve for the voltage and the capacity from the voltage curve obtained by the curve obtaining unit, select a plurality of peaks included in a predetermined voltage interval from the obtained differential curve, determine a first peak associated with the negative electrode and a second peak associated with the positive electrode among the plurality of selected peaks, compare the first peak and the second peak with the first reference peak and the second reference peak of a preset reference curve, respectively, and consider at least one of a behavioral change of the first peak relative to the first reference peak and a behavioral change of the second peak relative to the second reference peak to diagnose the state of the battery.

[0018] The control unit may be configured to set a largest peak in the reference curve as the first reference peak, and set a second largest peak as the second reference peak.

[0019] The peak may be a point where the slope is 0 in the reference curve and the differential curve, and refers to a point where the voltage changes from positive to negative according to the instantaneous rate of change of the voltage.

[0020] The control unit may be configured to determine a peak corresponding to a first reference peak in the differential curve as the first peak, and determine a peak corresponding to a second reference peak in the differential curve as the second peak.

[0021] The reference curve may be a curve of voltage and differential capacity for a reference cell corresponding to the battery, the voltage and differential capacity of the reference cell being measured while the reference cell is being charged within a predetermined C-rate range.

[0022] The differential curve may be a curve for the voltage and differential capacity of the battery, the voltage and differential capacity of the battery being measured while the battery is being charged within the same C-rate range as the reference cell.

[0023] The control unit may be configured to calculate a second peak variation value by comparing the second peak with a second reference peak, and diagnose whether the battery is deteriorated according to the second peak variation value.

[0024] When diagnosing battery degradation, the control unit may be configured to calculate a first peak variation value by comparing the first peak with a first reference peak, and diagnose a degradation cause of the battery based on the first peak variation value and the second peak variation value.

[0025] When the first peak variation value and the second peak variation value are equal to or greater than a predetermined size, the control unit may be configured to diagnose that the deterioration cause of the battery is negative electrode degradation and positive electrode degradation.

[0026] When the first peak variation value is smaller than a predetermined size and the second peak variation value is equal to or larger than a predetermined size, the control unit may be configured to diagnose that the deterioration cause of the battery is deterioration of the positive electrode.

[0027] Upon diagnosing battery degradation, the control unit may be configured to adjust at least one of an upper limit of the battery SOC, a lower limit of the battery SOC, and an upper limit of a charge / discharge C-rate of the battery.

[0028] In another aspect of the present invention, the apparatus for diagnosing a state of a battery may further include a storage unit configured to store the voltage curve obtained by the curve obtaining unit at each charging cycle of charging the battery.

[0029] The control unit may be configured to obtain a plurality of differential curves from a plurality of voltage curves stored in a storage unit, determine a plurality of first peaks and a plurality of second peaks in the plurality of differential curves, and diagnose whether the battery is degraded based on at least one of behavioral changes of the plurality of determined first peaks and behavioral changes of the plurality of determined second peaks.

[0030] The present disclosure also provides a battery pack including the apparatus for diagnosing a state of a battery according to the embodiment of the present disclosure.

[0031] The present disclosure also provides a vehicle including the apparatus for diagnosing a state of a battery according to the embodiment of the present disclosure.

[0032] In another aspect of the present disclosure, a method for diagnosing the state of a battery is provided, the method including: a voltage curve obtaining step, which obtains a voltage curve of the battery for the voltage and capacity of the battery; a differential curve obtaining step, which obtains a differential curve for the voltage and the capacity from the voltage curve obtained in the voltage curve obtaining step; a peak determination step, which selects a plurality of peaks included in a predetermined voltage interval from the differential curve obtained in the differential curve obtaining step, and determines a first peak associated with the negative electrode and a second peak associated with the positive electrode among the plurality of selected peaks; a peak comparison step, which compares the first peak and the second peak with the first reference peak and the second reference peak of a preset reference curve, respectively; and a battery state diagnosis step, which diagnoses the state of the battery by considering at least one of the behavioral changes of the first peak relative to the first reference peak and the behavioral changes of the second peak relative to the second reference peak.

[0033] Technical Effects

[0034] According to one aspect of the present disclosure, degradation of a battery may be diagnosed in consideration of behaviors of a first peak and a second peak included in a differential curve of the battery.

[0035] Furthermore, by specifically diagnosing degradation of the positive electrode or negative electrode of the battery, the cause of battery degradation can be diagnosed more accurately.

[0036] In addition, according to one aspect of the present disclosure, even if a battery is charged at a high rate of 0.1 C or more, by interpreting the differential curve, it is possible to diagnose whether the battery is deteriorated and / or what the cause of the degradation is.

[0037] The effects of the present disclosure are not limited to the above contents, and other effects not mentioned herein will be clearly understood by those skilled in the art from the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing 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 limited to the accompanying drawings.

[0039] Figure 1 is a diagram schematically showing a voltage curve according to the prior art.

[0040] Figure 2 is a diagram schematically showing a differential curve according to the prior art.

[0041] Figure 3 is a diagram schematically illustrating an apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0042] Figure 4 is a diagram schematically illustrating a reference curve of an apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0043] Figure 5 is a diagram schematically illustrating an example of a reference curve and a differential curve of an apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0044] Figure 6 is a diagram schematically illustrating another example of a reference curve and a differential curve of the apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0045] Figure 7 is a diagram schematically illustrating an example of a plurality of differential curves obtained by the apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0046] Figure 8 is a diagram schematically illustrating another example of a plurality of differential curves obtained by the apparatus for diagnosing the state of a battery according to an embodiment of the present disclosure.

[0047] Figure 9 is a diagram schematically illustrating a method for diagnosing a state of a battery according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0048] It should be understood that the terms used in the specification and the appended claims should not be interpreted as being limited to general and dictionary meanings, but should be interpreted based on 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 for the best interpretation.

[0049] Therefore, the descriptions provided herein are merely preferred examples for illustrative purposes only and are not intended to limit the scope of the present disclosure. It should be understood that other equivalent substitutions and modifications may be made thereto without departing from the scope of the present disclosure.

[0050] Additionally, in describing the present disclosure, when it is considered that a detailed description of related known elements or functions makes the key subject matter of the present disclosure unclear, the detailed description is omitted herein.

[0051] 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.

[0052] Throughout the specification, when a portion is referred to as “including” or “comprising” any element, unless explicitly mentioned otherwise, it means that the portion may further include other elements, rather than excluding other elements.

[0053] In addition, the term "control unit" described in the specification refers to a unit that processes at least one function or operation and can be implemented by hardware, software, or a combination of hardware and software.

[0054] In addition, 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.

[0055] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0056] Figure 3 is a diagram schematically illustrating an apparatus 100 for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0057] Reference Figure 3 , the apparatus 100 for diagnosing a state of a battery according to an embodiment of the present disclosure may include a curve obtaining unit 110 and a control unit 120 .

[0058] The curve obtaining unit 110 may be configured to obtain a voltage curve of the battery with respect to the voltage and capacity of the battery.

[0059] Here, a battery includes a negative terminal and a positive terminal and can refer to a physically separate individual battery cell. For example, a pouch-type lithium polymer battery can be considered a battery. Additionally, a battery can refer to a battery module in which one or more battery cells are connected in series and / or parallel.

[0060] Specifically, the curve obtaining unit 110 may obtain a voltage curve of the voltage and capacity of the battery measured while the battery is being charged and / or discharged.

[0061] For example, the curve obtaining unit 110 may obtain a voltage curve of a battery (such as Figure 1 That is, the voltage curve obtained by the curve obtaining unit 110 may represent the voltage of the battery relative to the capacity of the battery.

[0062] The control unit 120 may be configured to obtain a differential curve 300 for voltage and capacity from the voltage curve obtained by the curve obtaining unit 110 .

[0063] Specifically, the control unit 120 may be communicatively connected to the curve obtaining unit 110. For example, the curve obtaining unit 110 may send the obtained voltage curve to the control unit 120, and the control unit 120 may receive the voltage curve. As another example, the control unit 120 may obtain the voltage curve by accessing the curve obtaining unit 110.

[0064] After obtaining the voltage curve, the control unit 120 may obtain a differential curve 300 based on the voltage curve.

[0065] Specifically, the control unit 120 may calculate the differential capacity (dQ / dV) of the battery by differentiating the capacity Q of the battery from the voltage V of the battery, and obtain a differential curve 300 indicating the differential capacity of the battery with respect to the voltage of the battery.

[0066] Furthermore, the control unit 120 may be configured to select a plurality of peaks included in a predetermined voltage interval from the obtained differential curve 300 .

[0067] Here, the predetermined voltage interval is a preset voltage interval and may be the voltage interval to which the first reference peak R1 and the second reference peak R2 of the reference curve 200 belong. That is, the control unit 120 may select a plurality of peaks included in the voltage interval to which the first reference peak R1 and the second reference peak R2 of the reference curve 200 belong from the obtained differential curve 300.

[0068] Here, the reference curve 200 is a differential curve 300 of the reference cell and may be a curve indicating a differential of a capacity of the reference cell with respect to a voltage of the reference cell. In addition, the reference cell may be a cell corresponding to a battery.

[0069] For example, the reference cell may be the battery itself in the BOL (Beginning of Life) state, or may be a separate battery having the same specifications as the battery. Furthermore, the reference curve 200 may be an initial differential curve 300 obtained from the reference cell. As another example, the reference curve 200 may be a differential curve 300 of a battery previously obtained at a previous point in time. That is, the reference curve 200 is a reference curve for comparison with the differential curve 300 of the battery. As long as the curve is previously obtained before the control unit 120 obtains the differential curve 300 for diagnosing the battery's state, the curve may be considered as the reference curve 200 relative to the differential curve 300.

[0070] Preferably, the reference cell may be the target battery's BOL state, and the reference curve 200 may be the initial differential curve 300 of the reference cell. If the reference curve 200 is used to diagnose the battery's state, the control unit 120 can more accurately diagnose the difference between the battery's BOL state and the current state. Therefore, hereinafter, for ease of explanation and improved accuracy of battery state diagnosis, the reference cell will be described as referring to the target battery in the BOL state, and the reference curve 200 will be described as the initial differential curve 300 of the reference cell.

[0071] In addition, the control unit 120 may be configured to determine a first peak 310 associated with a negative pole and a second peak 320 associated with a positive pole among the plurality of selected peaks.

[0072] Preferably, in the differential curve 300 , the plurality of peaks included in the predetermined voltage interval may include a first peak 310 associated with the negative pole and a second peak 320 associated with the positive pole.

[0073] For example, the predetermined voltage interval may include two peaks. In this case, the control unit 120 may determine the low potential side peak as the first peak 310 and the high potential side peak as the second peak 320 .

[0074] The control unit 120 may be configured to compare the first peak 310 and the second peak 320 with the first reference peak R1 and the second reference peak R2 of the preset reference curve 200 , respectively.

[0075] Figure 4 is a diagram schematically illustrating a reference curve 200 of the apparatus 100 for diagnosing a state of a battery according to an embodiment of the present disclosure. Figure 5 is a diagram schematically illustrating an example of a reference curve 200 and a differential curve 300 of the apparatus 100 for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0076] Reference Figure 4 and Figure 5 , the first reference peak R1 and the second reference peak R2 may be included in the voltage interval of 3.6 [V] to 3.8 [V]. Figure 5 , the first peak 310 and the second peak 320 may be included in a voltage interval of 3.6 [V] to 3.8 [V].

[0077] Here, the peak is a point where the slope is 0 in the reference curve 200 and the differential curve 300 , and refers to a point where the voltage changes from positive to negative according to the instantaneous rate of change of the voltage.

[0078] For example, in Figure 5 In the embodiment, the slopes of the first reference peak R1, the second reference peak R2, the first peak 310, and the second peak 320 may be 0. That is, the first reference peak R1, the second reference peak R2, the first peak 310, and the second peak 320 may be upwardly convex points.

[0079] Preferably, the first peak 310 is a peak corresponding to the first reference peak R1, and the second peak 320 is a peak corresponding to the second reference peak R2. To this end, the control unit 120 can be configured to determine the peak corresponding to the first reference peak R1 in the differential curve 300 as the first peak 310, and determine the peak corresponding to the second reference peak R2 in the differential curve 300 as the second peak 320.

[0080] The control unit 120 may be configured to diagnose the state of the battery considering at least one of a behavior change of the first peak 310 relative to the first reference peak R1 and a behavior change of the second peak 320 relative to the second reference peak R2 .

[0081] Here, the behavior change may refer to a change from the differential capacity values ​​of the reference peaks R1 and R2 to the differential capacity values ​​of the peaks 310 and 320. For example, the behavior change of the peaks 310 and 320 may be determined by comparing the differential capacity values ​​of the reference peaks R1 and R2 with the differential capacity values ​​of the peaks 310 and 320 and calculating the difference. Figure 5 In the embodiment, since the differential capacity value of the first peak 310 is smaller than the differential capacity value of the first reference peak R1, the behavior change of the first peak 310 can be determined as having a reduced differential capacity value. In addition, since the differential capacity value of the second peak 320 is smaller than the differential capacity value of the second reference peak R2, the behavior change of the second peak 320 can be determined as having a reduced differential capacity value.

[0082] For example, the control unit 120 may diagnose whether the battery is degraded based on at least one of the behavior changes of the first peak 310 and the second peak 320. In addition, the control unit 120 may specifically diagnose whether the positive electrode of the battery is degraded and / or whether the negative electrode of the battery is degraded.

[0083] The apparatus 100 for diagnosing the state of a battery according to an embodiment of the present disclosure can diagnose whether the battery is deteriorating by considering the behavior of the first peak 310 and the second peak 320 included in the battery differential curve 300. Specifically, the apparatus 100 for diagnosing the state of a battery can more accurately diagnose the cause of battery deterioration by specifically diagnosing whether the positive electrode of the battery is deteriorating or the negative electrode of the battery is deteriorating.

[0084] In addition, the control unit 120 included in the device 100 for diagnosing the state of a battery according to an embodiment of the present disclosure may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, and a data processing device, etc., known in the art, to execute the various control logics disclosed below. In addition, when the control logic is implemented in software, the control unit 120 can be implemented as a set of program modules. In this case, the program modules can be stored in a memory and executed by the control unit 120. The memory can be provided inside or outside the control unit 120 and can be connected to the control unit 120 in various well-known ways.

[0085] The control unit 120 may be configured to set the largest peak in the reference curve 200 as the first reference peak R1, and the second largest peak as the second reference peak R2. Specifically, the control unit 120 may be configured to set the peak with the largest differential capacity value in the reference curve 200 as the first reference peak R1, and the peak with the second largest differential capacity value as the second reference peak R2.

[0086] For example, in Figure 4 In the reference curve 200, the maximum peak can be set as the first reference peak R1. Figure 4 In the reference curve 200, the second largest peak can be set as the second reference peak R2.

[0087] In addition, the control unit 120 may be configured to determine a peak corresponding to the first reference peak R1 in the differential curve 300 as the first peak 310 , and a peak corresponding to the second reference peak R2 in the differential curve 300 as the second peak 320 .

[0088] For example, the control unit 120 may determine a peak having a voltage value closest to the voltage value of the first reference peak R1 in the differential curve 300 as the first peak 310. Similarly, the control unit 120 may determine a peak having a voltage value closest to the voltage value of the second reference peak R2 in the differential curve 300 as the second peak 320.

[0089] That is, the apparatus 100 for diagnosing the state of a battery according to an embodiment of the present disclosure can more accurately diagnose the state of the battery based on the behavior changes between the reference peaks R1 and R2 of the reference curve 200 and the peaks 310 and 320 of the differential curve 300 corresponding to each other.

[0090] In addition, reference curve 200 may be a curve of the voltage and differential capacity of a reference cell measured while the reference cell corresponding to the battery is being charged within a predetermined C-rate range. Furthermore, differential curve 300 may be a curve of the voltage and differential capacity of the battery measured while the battery is being charged within the same C-rate range as the reference cell.

[0091] Here, the predetermined C-rate range may be a range of 0.1C or more. That is, the reference curve 200 may be a curve obtained while the reference cell is being charged at a high rate within a C-rate range of 0.1C or more. Preferably, the reference curve 200 may be a curve obtained while the reference cell is being charged at a C-rate of 0.2C or more and 1C or less. More preferably, the reference curve 200 may be a curve obtained while the reference cell is being charged at a C-rate of 0.33C or more and 1C or less. Hereinafter, for ease of description, the reference curve 200 and the differential curve 300 obtained while the reference cell and the battery, respectively, are being charged at a C-rate of 0.33C will be described.

[0092] at the same time, Figure 2 The differential curve 20 of may be a curve obtained while the battery cell is being charged at a C-rate of 0.05C. In the following, Figure 2 The differential curve 20 will be described as a curve obtained while the reference cell is being charged at a C-rate of 0.05C.

[0093] That is to say, Figure 2 The differential curve 20 of is a curve obtained while the reference cell is being charged at a low rate of a C-rate of about 0.05C, so that the first peak 21 to the sixth peak 26 can be clearly included. Figure 2 The differential curve 20 may include the first peak 21 to the sixth peak 26 to clearly distinguish them.

[0094] on the contrary, Figure 4 The reference curve 200 is obtained while the reference cell is being charged at a high rate with a C-rate of 0.33C. Figure 2 The first peak 21 to the sixth peak 26 included in the differential curve 20 of cannot be clearly distinguished. Specifically, if the reference cell is charged at a high rate of 0.33C, then Figure 2 The third peak 23 included in the differential curve 20 is divided into Figure 4The reference curve 200 includes a first reference peak R1 and a second reference peak R2. This is because, in the case of low-rate charging, the positive peak and the negative peak are mixed to form the third peak 23, but in the case of high-rate charging, the behavior of the positive and negative electrodes changes to change the potential bands forming the positive peak and the negative peak. Therefore, if the reference cell is charged at a high rate (for example, at a C-rate of 0.33C), then Figure 2 The third peak 23 included in the differential curve 20 can be divided into Figure 4 The reference curve 200 includes a first reference peak R1 and a second reference peak R2.

[0095] In addition, Figure 5 In the differential curve 300 of the embodiment of FIG, the control unit 120 may determine the peak corresponding to the first reference peak R1 as the first peak 310, and determine the peak corresponding to the second reference peak R2 as the second peak 320. Thereafter, the control unit 120 may diagnose the battery status based on the behavior change of the first peak 310 and / or the behavior change of the second peak 320.

[0096] Therefore, unlike the prior art that uses the differential curve 20 obtained by low-rate charging to diagnose the battery status, the device 100 for diagnosing the battery status according to an embodiment of the present disclosure has the advantage of diagnosing the battery status using the differential curve 300 obtained by high-rate charging. Specifically, since the battery status can be diagnosed even when the battery is charged at a high rate, there is an advantage that the battery status can be diagnosed more quickly.

[0097] In addition, the apparatus 100 for diagnosing the state of a battery according to an embodiment of the present disclosure has an advantage of providing a new peak interpretation capable of diagnosing the state of a battery through the behavior of the plurality of peaks 310 , 320 included in the differential curve 300 obtained by high-rate charging.

[0098] That is, the apparatus 100 for diagnosing the state of a battery may diagnose the state of the battery using the first reference peak R1 and the second reference peak R2 , which have not been used for diagnosing the state of the battery in the related art.

[0099] For example, in the prior art, due to the need for low-rate charging, there is a limitation: the battery status can only be diagnosed in limited situations where low-rate charging is possible (such as during a battery test phase). However, since the device 100 for diagnosing the battery status according to the present disclosure can diagnose the battery status even during high-rate charging, it is advantageous in that the battery status can be diagnosed even in various situations (such as when the battery is operating) in electronic devices (electronic products, vehicles, energy storage systems (ESS), etc.).

[0100] The control unit 120 may be configured to calculate a second peak variation value by comparing the second peak 320 with the second reference peak R2. In addition, the control unit 120 may be configured to diagnose whether the battery is deteriorated based on the second peak variation value.

[0101] For example, the control unit 120 may calculate the second peak variation value based on the value between the differential capacity of the second peak 320 and the differential capacity of the second reference peak R2. Specifically, the control unit 120 may calculate a value obtained by subtracting the differential capacity value of the second peak 320 from the differential capacity value of the second reference peak R2 as the second peak variation value.

[0102] In addition, if the calculated second peak change value is greater than or equal to a predetermined value, the control unit 120 may diagnose that the battery is deteriorating. Conversely, if the calculated second peak change value is less than the predetermined value, the control unit 120 may diagnose that the battery is not deteriorating. In this case, the predetermined value may preferably be a value fixed to an initial setting value.

[0103] Specifically, since the predetermined size is a reference value compared with the peak change value (the difference between the differential capacity value of the reference peak and the differential capacity value of the peak) in order to diagnose whether the battery is degraded, the predetermined size can be a fixed setting value regardless of the degree of battery degradation.

[0104] Therefore, the apparatus 100 for diagnosing the state of a battery according to an embodiment of the present disclosure has the advantage of quickly diagnosing whether the battery is deteriorated considering only the peak variation value between the second reference peak R2 and the second peak 320 .

[0105] If battery degradation is diagnosed, the control unit 120 may be configured to calculate a first peak variation value by comparing the first peak 310 with the first reference peak R1. Specifically, the control unit 120 may calculate a value obtained by subtracting the differential capacity value of the first peak 310 from the differential capacity value of the first reference peak R1 as the first peak variation value.

[0106] In addition, the control unit 120 may be configured to diagnose a degradation cause of the battery based on the first peak variation value and the second peak variation value.

[0107] Specifically, the control unit 120 can diagnose the cause of battery degradation as positive electrode degradation and / or negative electrode degradation based on the first peak change value and the second peak change value. Here, negative electrode degradation indicates loss of available lithium, thus degrading the negative electrode of the battery. Additionally, positive electrode degradation indicates loss of positive electrode reaction area, thus degrading the positive electrode of the battery.

[0108] For example, after diagnosing battery degradation based on the second peak variation value, control unit 120 may calculate a first peak variation value based on the difference between the differential capacity value of first peak 310 and the differential capacity value of first reference peak R1 to diagnose the cause of battery degradation. Furthermore, if the calculated first peak variation value is greater than or equal to a predetermined value, control unit 120 may diagnose that the cause of battery degradation is negative electrode degradation and positive electrode degradation. Conversely, if the calculated first peak variation value is less than the predetermined value, control unit 120 may diagnose that the cause of battery degradation is positive electrode degradation.

[0109] Specifically, if the calculated first peak change value is greater than or equal to a predetermined value, the control unit 120 can diagnose the primary cause of battery degradation by comparing the first peak change value with the second peak change value. For example, if the first peak change value is greater than the second peak change value, the control unit 120 can diagnose that the primary cause of battery degradation is negative electrode degradation. Conversely, if the first peak change value is less than the second peak change value, the control unit 120 can diagnose that the primary cause of battery degradation is positive electrode degradation.

[0110] Figure 6 is a diagram schematically illustrating another example of a reference curve 200 and a differential curve 300 of the apparatus 100 for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0111] Specifically, Figure 5 is a diagram schematically showing a differential curve 300 of a battery with degraded negative and positive electrodes, and Figure 6 FIG3 is a diagram schematically showing a differential curve 300 of a battery with degraded positive electrodes.

[0112] Reference Figure 5 and Figure 6 If the positive electrode of the battery degrades, the second peak variation between the second reference peak R2 and the second peak 320 may be greater than or equal to a predetermined value. In other words, if the positive electrode of the battery degrades, the differential capacity value of the second peak 320 may be smaller than the differential capacity value of the second reference peak R2 by at least a predetermined value.

[0113] In addition, refer again Figure 5 and Figure 6 If the negative electrode of the battery degrades, the first peak variation between the first reference peak R1 and the first peak 310 may be greater than or equal to a predetermined value. In other words, if the negative electrode of the battery degrades, the differential capacity value of the first peak 310 may be smaller than the differential capacity value of the first reference peak R1 by at least a predetermined value.

[0114] That is, the control unit 120 may be configured to diagnose a loss of the negative and positive electrodes of the battery if the first peak change value and the second peak change value are equal to or greater than a predetermined value. Alternatively, if the first peak change value is less than a predetermined value and the second peak change value is greater than or equal to a predetermined value, the control unit 120 may be configured to diagnose a loss of the positive electrode of the battery.

[0115] Therefore, the apparatus 100 for diagnosing the state of a battery according to an embodiment of the present disclosure has the advantages of quickly diagnosing whether the battery is deteriorated based on the second peak variation value and specifically determining the degradation cause of the battery based on the first peak variation value.

[0116] As another example, multiple reference ranges may be preset for the first peak variation value and the second peak variation value of the battery. For example, the multiple reference ranges may include a first reference range, a second reference range, and a third reference range. However, it should be noted that the multiple reference ranges may be divided more finely, rather than being divided into only three ranges as described below.

[0117] The control unit 120 may compare the first peak variation value and the second peak variation value with a plurality of reference ranges, and diagnose whether the battery is deteriorated according to the comparison result.

[0118] After calculating the second peak change value, the control unit 120 can determine the second target range to which the second peak change value belongs from among the multiple reference ranges. Furthermore, the control unit 120 can diagnose whether the battery is deteriorating based on the content set in the second target range. For example, if the second target range is the first reference range, the control unit 120 can diagnose that the battery is not deteriorating. Conversely, if the second target range is the second reference range or the third reference range, the control unit 120 can diagnose that the battery is deteriorating.

[0119] If battery degradation is diagnosed, the control unit 120 may calculate a first peak variation value between the first reference peak R1 and the first peak 310. Furthermore, the control unit 120 may determine a first target range to which the first peak variation value belongs from among a plurality of reference ranges. Furthermore, the control unit 120 may diagnose the cause of battery degradation based on the content set in the first target range.

[0120] For example, if the first target range is the first reference range, control unit 120 may diagnose that the cause of battery degradation is positive electrode degradation. Conversely, if the first target range is the second reference range or the third reference range, control unit 120 may diagnose that the cause of battery degradation is positive electrode degradation and negative electrode degradation. The following details the results of control unit 120's determination based on the combination of the first target range and the second target range, based on Table 1.

[0121] More specifically, the control unit 120 may compare the first peak variation value and the second peak variation value with a plurality of reference ranges, and diagnose the degree of battery degradation according to the comparison result.

[0122] As described above, the first reference range can be set to an allowable error range. That is, the first reference range can represent a normal range. The second reference range can represent a warning range indicating that the battery has degraded to the point where the battery state is in a warning state. The third reference range can represent a danger range indicating that the battery has degraded to the point where the battery state is in a dangerous state.

[0123] Table 1 below shows the diagnosis results of the control unit 120 according to which range the first peak change value and the second peak change value belong to among a plurality of reference ranges.

[0124] [Table 1]

[0125]

[0126] As described above, the first target range refers to the range of the first peak change value within the multiple reference ranges. Similarly, the second target range refers to the range of the second peak change value within the multiple reference ranges. In addition, the contents in brackets in Table 1 indicate the above-mentioned warning state or danger state.

[0127] Specifically, if the second target range is the first reference range, the control unit 120 may diagnose that the battery is not deteriorated.

[0128] Furthermore, if the first target range is the first reference range, control unit 120 can diagnose that the cause of battery degradation is not negative electrode degradation. In other words, control unit 120 can diagnose that the battery is not degraded or that the positive electrode of the battery is degraded. Preferably, since control unit 120 determines the first target range after first determining the second target range, if the first target range is the first reference range, control unit 120 can diagnose that the cause of battery degradation is positive electrode degradation.

[0129] If the second target range is the second reference range, the control unit 120 may diagnose that the battery is degraded and the degradation cause is positive electrode degradation. In addition, the control unit 120 may diagnose the degree of degradation of the battery positive electrode as a warning state.

[0130] In addition, if the second target range is the third reference range, the control unit 120 may diagnose that the battery is degraded and the cause of the degradation is positive electrode degradation. In addition, the control unit 120 may diagnose that the degree of degradation of the positive electrode of the battery is a dangerous state.

[0131] If the second target range is the second reference range or the third reference range and the first target range is the second reference range, the control unit 120 may diagnose that the battery is degraded and the cause of the degradation is negative electrode degradation. In addition, the control unit 120 may diagnose the degree of degradation of the battery negative electrode as a warning state.

[0132] In addition, if the second target range is the second reference range or the third reference range and the first target range is the third reference range, the control unit 120 can diagnose battery degradation and determine whether the degradation is caused by negative electrode degradation. In addition, the control unit 120 can diagnose the degree of degradation of the battery negative electrode as a dangerous state.

[0133] That is, referring to Table 1, the control unit 120 can diagnose whether the battery is degraded, the cause of the degradation, and the degree of the degradation based on a combination of the first target range and the second target range.

[0134] Therefore, the device 100 for diagnosing the state of a battery according to an embodiment of the present disclosure can diagnose the state of the battery in detail in various aspects. In addition, since the state of the battery can be diagnosed even when the battery is charged at a high rate, the state of the battery can be diagnosed faster.

[0135] In addition, as described above, the plurality of reference ranges may be divided not only into the three ranges in Table 1 but also into finer ranges. In this case, the control unit 120 may diagnose the degree of degradation of the battery more specifically.

[0136] If battery degradation is diagnosed, the control unit 120 may be configured to adjust at least one of an upper limit of an SOC (State of Charge) of the battery, a lower limit of the SOC, and an upper limit of a charge / discharge C-rate.

[0137] In order to slow down the degradation rate of the battery, the control unit 120 may be configured to adjust at least one of an upper limit of the SOC at which the battery can be maximally charged, a lower limit of the SOC at which the battery can be maximally discharged, an upper limit of the battery charge C-rate, and a lower limit of the battery discharge C-rate.

[0138] Specifically, the control unit 120 may lower the upper limit of the battery's SOC. The control unit 120 may increase the lower limit of the battery's SOC. The control unit 120 may lower the upper limit of the charge C-rate. The control unit 120 may lower the upper limit of the discharge C-rate.

[0139] That is, the apparatus 100 for diagnosing the state of a battery according to an embodiment of the present disclosure has an advantage of taking measures for slowing down the degradation rate of the battery according to the diagnosis result after diagnosing whether the battery is deteriorated.

[0140] The apparatus 100 for diagnosing a state of a battery according to an embodiment of the present disclosure may further include a storage unit 130 .

[0141] Here, the storage unit 130 can store programs, data, and the like required for the control unit 120 to diagnose the battery's condition. Specifically, the storage unit 130 can store data required for the operation and function of each component of the device 100 for diagnosing the battery's condition, data generated during the execution of operations or functions, and the like. The storage unit 130 is not particularly limited in type, as long as it is a known information storage device that can record, erase, update, and read data. Examples of information storage devices include RAM, flash memory, ROM, EEPROM, registers, and the like. Furthermore, the storage unit 130 can store program code that defines the processes that the control unit 120 can execute.

[0142] The storage unit 130 may be configured to store the voltage curve obtained by the curve obtaining unit 110 at each charging cycle of charging the battery.

[0143] Preferably, the storage unit 130 may store the voltage curve of each charging cycle for differentiation. For example, the storage unit 130 may set the index of the charging cycle to the voltage curve stored therein.

[0144] The control unit 120 may be configured to obtain multiple differential curves 300 from the multiple voltage curves stored in the storage unit 130. That is, the control unit 120 and the storage unit 130 may be communicatively connected. The control unit 120 may obtain at least one voltage curve stored in the storage unit 130 by accessing the storage unit 130. Preferably, the control unit 120 may obtain multiple voltage curves stored in the storage unit 130.

[0145] In addition, the control unit 120 may selectively obtain a portion of the plurality of voltage curves stored in the storage unit 130. In this case, the control unit 120 may select a voltage curve to be obtained by an index set for the voltage curve.

[0146] Figure 7 FIG. 1 is a diagram schematically illustrating an example of a plurality of differential curves 300 obtained by the apparatus 100 for diagnosing a battery state according to an embodiment of the present disclosure. Figure 8 FIG. 1 is a diagram schematically illustrating another example of a plurality of differential curves 300 obtained by the apparatus 100 for diagnosing a state of a battery according to an embodiment of the present disclosure.

[0147] Preferably, the reference curve 200 , the first differential curve 300 a , the second differential curve 300 b , the third differential curve 300 c , the fourth differential curve 300 d , and the fifth differential curve 300 e may be stored in the storage unit 130 .

[0148] For example, in Figure 7 In the embodiment of the present invention, the control unit 120 can selectively obtain the first differential curve 300a, the second differential curve 300b and the third differential curve 300c from the storage unit 130. As another example, in Figure 8 In the embodiment of the present invention, the control unit 120 may selectively obtain the fourth differential curve 300d and the fifth differential curve 300e from the storage unit 130.

[0149] For ease of description, it is assumed that the number of charge / discharge cycles of a battery increases in the order of first differential curve 300a, second differential curve 300b, and third differential curve 300c. For example, first differential curve 300a is a differential curve 300 for a battery with 100 charge / discharge cycles, second differential curve 300b is a differential curve 300 for a battery with 200 charge / discharge cycles, and third differential curve 300c is a differential curve 300 for a battery with 300 charge / discharge cycles. Furthermore, it is assumed that the number of charge / discharge cycles of a battery shown in fourth differential curve 300d is less than the number of charge / discharge cycles of a battery shown in fifth differential curve 300e.

[0150] Additionally, the control unit 120 may be configured to determine a plurality of first peaks 310 and a plurality of second peaks 320 among the plurality of differential curves 300 .

[0151] In each of the plurality of differential curves 300 , the control unit 120 may determine a peak corresponding to the first reference peak R1 of the reference curve 200 as a first peak 310 and a peak corresponding to the second reference peak R2 as a second peak 320 .

[0152] Reference Figure 7 , the control unit 120 may determine the first peaks 310a, 310b, 310c and the second peaks 320a, 320b, 320c in the first differential curve 300a, the second differential curve 300b and the third differential curve 300c. Figure 8 , the control unit 120 may determine first peaks 310d, 310e and second peaks 320d, 320e in the fourth differential curve 300d and the fifth differential curve 300e, respectively.

[0153] That is, the first peak 310a of the first differential curve 300a, the first peak 310b of the second differential curve 300b, the first peak 310c of the third differential curve 300c, the first peak 310d of the fourth differential curve 300d, and the first peak 310e of the fifth differential curve 300e may all be peaks corresponding to the first reference peak R1 of the reference curve 200.

[0154] Similarly, the second peak 320a of the first differential curve 300a, the second peak 320b of the second differential curve 300b, the second peak 320c of the third differential curve 300c, the second peak 320d of the fourth differential curve 300d, and the second peak 320e of the fifth differential curve 300e may all be peaks corresponding to the second reference peak R2 of the reference curve 200.

[0155] The control unit 120 may be configured to diagnose whether the battery is degraded based on at least one of the plurality of determined behavior changes of the first peaks 310 and the plurality of determined behavior changes of the second peaks 320 .

[0156] For example, in Figure 7 In an embodiment, the control unit 120 may calculate the difference in differential capacity of the plurality of second peaks 320 based on the number of charge / discharge cycles of the battery. Specifically, the control unit 120 may calculate the peak variation value based on the difference between the differential capacity value of the second peak 320a of the first differential curve 300a and the differential capacity value of the second peak 320b of the second differential curve 300b. Furthermore, the control unit 120 may calculate the peak variation value based on the difference between the differential capacity value of the second peak 320b of the second differential curve 300b and the differential capacity value of the second peak 320c of the third differential curve 300c.

[0157] If the peak variation value between the plurality of second peaks 320 increases as the number of charge / discharge cycles of the battery increases, the control unit 120 can diagnose that the degradation of the battery is accelerating. Conversely, if the peak variation value between the plurality of second peaks 320 decreases as the number of charge / discharge cycles of the battery increases, the control unit 120 can diagnose that the degradation of the battery is decelerating.

[0158] For example, if the peak change value between second peak 320b of second differential curve 300b and second peak 320c of third differential curve 300c is greater than the peak change value between second peak 320a of first differential curve 300a and second peak 320b of second differential curve 300b, control unit 120 may diagnose accelerated battery degradation. In this case, at least one of the second peak change value between second reference peak R2 of reference curve 200 and second peak 320a of first differential curve 300a, the second peak change value between second reference peak R2 and second peak 320b of second differential curve 300b, and the second peak change value between second reference peak R2 and second peak 320c of third differential curve 300c may be greater than or equal to a predetermined value. In other words, if battery degradation is diagnosed based on at least one of the plurality of obtained differential curves 300a, 300b, and 300c, control unit 120 may diagnose whether the battery is deteriorating.

[0159] In the above, refer to Figure 7The embodiment in which the control unit 120 diagnoses whether the battery is deteriorated based on the first differential curve 300a, the second differential curve 300b, and the third differential curve 300c has been described. However, unlike Figure 7 In the embodiment of the present invention, the control unit 120 can diagnose whether the battery is deteriorated based on a larger number of differential curves 300. In this case, the degradation of the battery can be diagnosed more accurately.

[0160] Hereinafter, an embodiment will be described in which control unit 120 diagnoses the cause of battery degradation based on at least one of the behavioral changes of first peak 310 and the behavioral changes of multiple second peaks 320. However, for ease of explanation, it should be noted that a repetitive description of the above content is not included. Furthermore, the behavioral changes of multiple first peaks 310 described below can be described based on the behavioral changes of multiple second peaks 320 described above.

[0161] The control unit 120 may be configured to diagnose a degradation cause of the battery based on at least one of the plurality of determined behavior changes of the first peaks 310 and the plurality of determined behavior changes of the second peaks 320 .

[0162] For example, it is assumed that the control unit 120 diagnoses that the degradation of the battery is accelerated based on the behavioral changes of the plurality of second peaks 320. That is, it is assumed that the peak variation values ​​between the plurality of second peaks 320 increase as the number of charge / discharge cycles of the battery increases, so that the control unit 120 diagnoses that the degradation of the battery is accelerated. Figure 7 In the embodiment of FIG, if the peak variation value between the plurality of first peaks 310 increases with the increase in the number of charge / discharge cycles of the battery, the control unit 120 can diagnose that the cause of the accelerated degradation of the battery is the degradation of the positive electrode and the negative electrode. Figure 8 In the embodiment, if the peak variation value between the plurality of first peaks 310 does not increase even if the number of charge / discharge cycles of the battery increases, the control unit 120 may diagnose that the cause of the accelerated degradation of the battery is degradation of the positive electrode.

[0163] The apparatus 100 for diagnosing the state of a battery according to an embodiment of the present disclosure has an advantage in diagnosing not only whether the battery is deteriorated but also the cause of the deterioration of the battery, thereby diagnosing the state of the battery more specifically.

[0164] The device 100 for diagnosing the state of a battery according to an embodiment of the present disclosure can be applied to a BMS (battery management system). That is, the BMS according to the present disclosure may include the device 100 for diagnosing the state of a battery. In this configuration, at least some components of the device 100 for diagnosing the state of a battery can be implemented by supplementing or increasing the functions of components included in a traditional BMS. For example, the curve obtaining unit 110, the control unit 120, and the storage unit 130 of the device 100 for diagnosing the state of a battery can be implemented as components of the BMS.

[0165] In addition, the device 100 for diagnosing the status of a battery according to an embodiment of the present disclosure can be provided to a battery pack. For example, the battery pack according to the present disclosure may include the device 100 for diagnosing the status of a battery and at least one battery cell. In addition, the battery pack may also include electrical equipment (relays, fuses, etc.), a housing, etc.

[0166] Figure 9 FIG2 is a diagram schematically illustrating a method for diagnosing a battery status according to another embodiment of the present disclosure. Each step of the method for diagnosing a battery status may be performed by the apparatus 100 for diagnosing a battery status.

[0167] Reference Figure 9 , a method for diagnosing a battery state may include a voltage curve obtaining step (S100), a differential curve obtaining step (S200), a peak determining step (S300), a peak comparing step (S400) and a battery state diagnosing step (S500).

[0168] The voltage curve obtaining step (S100) is a step of obtaining a voltage curve of the battery with respect to the voltage and capacity of the battery, and may be performed by the curve obtaining unit 110. For example, while the battery is being charged at a C-rate of 0.33C, the voltage curve may be obtained.

[0169] The differential curve obtaining step ( S200 ) is a step of obtaining the differential curve 300 for voltage and capacity from the voltage curve obtained in the voltage curve obtaining step ( S100 ), and may be performed by the control unit 120 .

[0170] Here, the voltage curve is a curve of capacity Q and voltage V, and the differential curve 300 is a curve of voltage V and differential capacity (dQ / dV).

[0171] The peak determination step (S300) is a step of selecting a plurality of peaks included in a predetermined voltage interval from the differential curve 300 obtained in the differential curve acquisition step (S200), and determining a first peak 310 associated with the negative pole and a second peak 320 associated with the positive pole among the plurality of selected peaks, and can be performed by the control unit 120.

[0172] The predetermined voltage interval may be a preset voltage interval to which the first reference peak R1 and the second reference peak R2 of the reference curve 200 belong. Figure 5 and Figure 6 In an embodiment, the control unit 120 may determine a first reference peak R1 and a second reference peak R2 in the reference curve 200. Preferably, the first reference peak R1 is a peak having a maximum differential capacity value in the reference curve 200, and the second reference peak R2 is a peak having a second maximum differential capacity value in the reference curve 200. In addition, the control unit 120 may determine the peak corresponding to the first reference peak R1 as a first peak 310 in the differential curve 300, and determine the peak corresponding to the second reference peak R2 as a second peak 320.

[0173] The peak comparison step ( S400 ) is a step of comparing the first peak 310 and the second peak 320 with the first reference peak R1 and the second reference peak R2 of the preset reference curve 200 , respectively, and may be performed by the control unit 120 .

[0174] Specifically, based on the change in the differential capacity value, the control unit 120 may determine a behavior change of the first peak 310 relative to the first reference peak R1 and determine a behavior change of the second peak 320 relative to the second reference peak R2.

[0175] The battery state diagnosis step ( S500 ) is a step of diagnosing the state of the battery considering at least one of the behavior change of the first peak 310 relative to the first reference peak R1 and the behavior change of the second peak 320 relative to the second reference peak R2 , and may be performed by the control unit 120 .

[0176] For example, the control unit 120 may diagnose whether the battery is degraded based on at least one of the behavior changes of the first peak 310 and the second peak 320. In addition, the control unit 120 may specifically diagnose whether the battery positive electrode is degraded and / or whether the battery negative electrode is degraded.

[0177] The method for diagnosing the state of a battery according to an embodiment of the present disclosure can diagnose whether the battery is deteriorating by considering the behavior of the first peak 310 and the second peak 320 included in the battery differential curve 300. Specifically, the method for diagnosing the state of a battery can more accurately diagnose the cause of battery deterioration by specifically diagnosing whether the positive electrode of the battery is deteriorating or whether the negative electrode of the battery is deteriorating.

[0178] The embodiments of the present disclosure described above are not necessarily implemented by devices and methods, but may also be implemented by a program for implementing functions corresponding to the configurations of the present disclosure or a recording medium having the program recorded thereon. Those skilled in the art can easily perform such implementation from the above description of the embodiments.

[0179] 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 example only, as various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art based on this detailed description.

[0180] Additionally, those skilled in the art may make many substitutions, modifications and changes to the disclosure described above without departing from the technical aspects of the disclosure, and the disclosure is not limited to the above-described embodiments and drawings, and each embodiment may be selectively combined in part or in whole to allow various modifications.

[0181] (List of Reference Signs)

[0182] 10: Voltage curve

[0183] 20: Differential Curve

[0184] 100: Device for diagnosing the status of the battery

[0185] 110: Curve acquisition unit

[0186] 120: Control unit

[0187] 130: Storage unit

[0188] 200: Reference curve

[0189] 300: Differential Curve

[0190] 310: First Peak

[0191] 320: Second Peak

[0192] R1, R2: reference peaks

Claims

1. A device for diagnosing a battery condition, the device comprising: a curve obtaining unit configured to obtain a voltage curve of a battery corresponding to voltage and capacity of the battery; as well as a control unit configured to obtain a differential curve for the voltage and the capacity from the voltage curve obtained by the curve obtaining unit, select a plurality of peaks included in a predetermined voltage interval from the obtained differential curve, determine a first peak associated with the negative electrode and a second peak associated with the positive electrode among the plurality of selected peaks, compare the first peak and the second peak with a first reference peak and a second reference peak of a preset reference curve, respectively, and diagnose the state of the battery by taking into account at least one of a change in behavior of the first peak relative to the first reference peak and a change in behavior of the second peak relative to the second reference peak, The control unit is configured to set the largest peak in the reference curve as the first reference peak, and set the second largest peak as the second reference peak.

2. The device according to claim 1, in, The peak is a point where the slope is 0 in the reference curve and the differential curve, and refers to a point where the voltage changes from positive to negative according to the instantaneous rate of change of the voltage.

3. The device according to claim 1, in, The control unit is configured to determine a peak corresponding to the first reference peak in the differential curve as the first peak, and determine a peak corresponding to the second reference peak in the differential curve as the second peak.

4. The device according to claim 1, in, The reference curve is a curve of voltage and differential capacity for a reference cell corresponding to the battery, the voltage and differential capacity of the reference cell being measured while the reference cell is being charged within a predetermined C-rate range.

5. The device according to claim 4, in, The differential curve is a curve for the voltage and differential capacity of the battery, which are measured while the battery is being charged in the same C-rate range as the reference cell.

6. The device according to claim 1, in, The control unit is configured to calculate a second peak variation value by comparing the second peak with the second reference peak, and diagnose whether the battery is deteriorated according to the second peak variation value.

7. The device according to claim 6, in, When diagnosing degradation of the battery, the control unit is configured to calculate a first peak variation value by comparing the first peak with the first reference peak, and diagnose a degradation cause of the battery based on the first peak variation value and the second peak variation value.

8. The device according to claim 7, in, When the first peak variation value and the second peak variation value are equal to or greater than a predetermined size, the control unit is configured to diagnose that the deterioration cause of the battery is negative electrode degradation and positive electrode degradation.

9. The apparatus according to claim 8, wherein The negative electrode degradation refers to the loss of available lithium and thus the degradation of the negative electrode of the battery, and the positive electrode degradation refers to the loss of positive electrode reaction area and thus the degradation of the positive electrode of the battery.

10. The apparatus according to claim 9, wherein If the first peak change value is greater than the second peak change value, the control unit is configured to diagnose that the cause of degradation of the battery is degradation of the negative electrode, and if the first peak change value is less than the second peak change value, the control unit is configured to diagnose that the cause of degradation of the battery is degradation of the positive electrode.

11. The device according to claim 7, in, When the first peak variation value is smaller than a predetermined size and the second peak variation value is equal to or larger than the predetermined size, the control unit is configured to diagnose that a cause of deterioration of the battery is positive electrode deterioration.

12. The apparatus according to claim 6, in, Upon diagnosing degradation of the battery, the control unit is configured to adjust at least one of an upper limit of a state of charge (SOC) of the battery, a lower limit of the SOC of the battery, and an upper limit of a charge / discharge C-rate of the battery.

13. The apparatus according to claim 1, further comprising: a storage unit configured to store the voltage curve obtained by the curve obtaining unit in each charging cycle of charging the battery, The control unit is configured to obtain a plurality of differential curves from the plurality of voltage curves stored in the storage unit, determine a plurality of first peaks and a plurality of second peaks in the plurality of differential curves, and diagnose whether the battery is degraded based on at least one of the behavioral changes of the plurality of determined first peaks and the behavioral changes of the plurality of determined second peaks.

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

15. A vehicle comprising an apparatus according to any one of claims 1 to 13.

16. A method for diagnosing a battery status, the method comprising: a voltage curve obtaining step, wherein the voltage curve obtaining step obtains a voltage curve of a battery corresponding to the voltage and capacity of the battery; a differential curve obtaining step of obtaining a differential curve with respect to the voltage and the capacity from the voltage curve obtained in the voltage curve obtaining step; a peak determining step of selecting a plurality of peaks included in a predetermined voltage interval from the differential curve obtained in the differential curve obtaining step, and determining a first peak associated with a negative electrode and a second peak associated with a positive electrode among the plurality of selected peaks; a peak comparison step of comparing the first peak and the second peak with a first reference peak and a second reference peak of a preset reference curve, respectively; and a battery state diagnosing step of diagnosing the state of the battery by taking into account at least one of a behavior change of the first peak relative to the first reference peak and a behavior change of the second peak relative to the second reference peak, Wherein, the peak determination step comprises the following steps: The largest peak in the reference curve is set as the first reference peak, and the second largest peak is set as the second reference peak.

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