Apparatus and method for diagnosing secondary battery

Abstract

The present invention discloses a secondary battery diagnostic device, etc., capable of effectively diagnosing the state of a secondary battery using charge / discharge signals extracted from a secondary battery. A secondary battery diagnostic device according to one aspect of the present invention includes: a memory unit storing a positive reference profile and a negative reference profile for charging or discharging a reference battery; a voltage measuring unit configured to measure the voltage of a target battery during a charging or discharging process; and a processor configured to generate a charge / discharge measurement profile based on the voltage measured by the voltage measuring unit, and to determine a positive adjustment profile and a negative adjustment profile by comparing a simulation profile obtained from the positive reference profile and negative reference profile stored in the memory unit with the generated charge / discharge measurement profile, such that the error between the simulation profile and the charge / discharge measurement profile is within a certain level.

Description

Technology Field

[0001] The present invention relates to a secondary battery diagnostic technology, and more specifically, to a battery diagnostic technology capable of effectively diagnosing the condition of a secondary battery using the charge / discharge signal of the secondary battery. Background Technology

[0002] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0003] Moreover, recently, secondary batteries are being widely used for driving or energy storage in medium-to-large-sized devices such as electric vehicles and Energy Storage Systems (ESS). As a result, interest in secondary batteries is increasing, and related research and development is becoming more active.

[0004] Lithium secondary batteries primarily use lithium-based oxides and carbon materials as positive and negative active materials, respectively. Furthermore, the lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing, namely a battery case, that seals and houses the electrode assembly together with an electrolyte.

[0005] Rechargeable batteries generate electrical energy through electrochemical oxidation and reduction reactions. However, as charge and discharge cycles are repeated, the performance of rechargeable batteries does not remain at their initial manufacturing capacity—the BOL (Beginning Of Life) state—and can degrade over time. If this degradation state of rechargeable batteries is not properly identified, it becomes difficult to accurately predict their State of Charge (SOC), usable time, lifespan, and replacement timing. Furthermore, inaccurate predictions in this regard can result in unforeseen damage to users or managers of the rechargeable batteries.

[0006] Furthermore, defective batteries may occur during the manufacturing process of secondary batteries. For example, among the numerous batteries produced, at least some may appear that do not meet the designed capacity or operating range due to process errors or other factors. Even if such defective secondary batteries are manufactured unavoidably, it is necessary to ensure they are not shipped externally through inspection. Alternatively, even if they are shipped externally, it is advisable to diagnose the defects early in the period of use.

[0007] In this regard, various technologies have been proposed to diagnose the degree of degradation during use or the presence of manufacturing defects in secondary batteries. However, the diagnostic technologies proposed so far have several issues, such as relatively complex calculation methods or low accuracy. Therefore, there is still a need for efficient secondary battery diagnostic technologies that are simpler and more accurate. The problem to be solved

[0008] The present invention was devised to solve the above-mentioned problems and aims to provide a secondary battery diagnostic device and method capable of effectively diagnosing the state of a secondary battery using charge / discharge signals extracted from the secondary battery, as well as a battery pack including such a diagnostic device.

[0009] Other objects and advantages of the present invention may be understood from the following description and will become more clearly apparent from the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0010] A secondary battery diagnostic device according to one aspect of the present invention for achieving the above-mentioned purpose comprises: a memory unit storing a positive reference profile and a negative reference profile for charging or discharging a reference battery; a voltage measuring unit configured to measure the voltage of a target battery during a charging or discharging process; and a processor configured to generate a charge / discharge measurement profile based on the voltage measured by the voltage measuring unit, and to determine a positive adjustment profile and a negative adjustment profile by comparing a simulation profile obtained from the positive reference profile and negative reference profile stored in the memory unit with the generated charge / discharge measurement profile, such that the error between the simulation profile and the charge / discharge measurement profile is within a certain level.

[0011] Here, the processor may be configured to determine the anode adjustment profile and the cathode adjustment profile by moving at least one of the anode reference profile and the cathode reference profile in a horizontal direction.

[0012] Additionally, the processor may be configured to determine the anode adjustment profile and the cathode adjustment profile by scaling at least one of the anode reference profile and the cathode reference profile in a horizontal direction.

[0013] Additionally, the voltage measuring unit may be configured to measure the full discharge voltage and full charge voltage of the target battery, and the processor may be configured to estimate the positive initiation value of the positive adjustment profile or the negative initiation value of the negative adjustment profile based on the full discharge voltage, and to estimate the positive final value of the positive adjustment profile and the negative final value of the negative adjustment profile based on the full charge voltage.

[0014] Additionally, the processor may be configured to determine the capacity of the target battery based on the difference between the positive final value and the positive starting value or the difference between the negative final value and the negative starting value.

[0015] In addition, the processor may be configured to identify the positive unused area and the negative unused area of ​​the target battery based on the positive adjustment profile and the negative adjustment profile.

[0016] In addition, the processor may be configured to determine whether the internal resistance of the target battery increases by using the result of the parallel shift when the error with the charge / discharge measurement profile is reduced by shifting the simulation profile in the vertical direction.

[0017] In addition, a battery pack according to another aspect of the present invention for achieving the above-mentioned purpose includes a secondary battery diagnostic device according to the present invention.

[0018] In addition, an automobile according to another aspect of the present invention for achieving the above-mentioned purpose includes a secondary battery diagnostic device according to the present invention.

[0019] In addition, a secondary battery diagnostic method according to another aspect of the present invention for achieving the above-mentioned purpose comprises: storing a positive reference profile and a negative reference profile for charging or discharging a reference battery; measuring a voltage while charging or discharging a target battery; generating a charge / discharge measurement profile based on the voltage measured in the voltage measurement step; comparing a simulation profile obtained from the positive reference profile and negative reference profile stored in the storage step with the charge / discharge measurement profile generated in the generation step; and determining a positive adjustment profile and a negative adjustment profile such that the error between the simulation profile and the charge / discharge measurement profile is within a certain level. Effects of the invention

[0020] According to one aspect of the present invention, the state of a secondary battery can be accurately diagnosed in a simple manner using charge / discharge signals.

[0021] In particular, in the case of the present invention, even without disassembling the secondary battery or manufacturing it into a three-electrode cell form, the positive voltage profile and the negative voltage profile can be extracted from the charge / discharge voltage profile of the secondary battery.

[0022] According to one embodiment of the present invention, the condition of the secondary battery can be effectively diagnosed during use.

[0023] In addition, according to another embodiment of the present invention, it can be applied to a secondary battery manufacturing process, such as a secondary battery formation process, to verify whether the manufactured secondary battery properly possesses the designed specifications.

[0024] Furthermore, in the case of the present invention, since the secondary battery is diagnosed in a non-destructive manner, the secondary battery that is found to be free of defects in the diagnosis results may be continuously used, manufactured, or shipped.

[0025] In addition, according to one embodiment of the present invention, the degree of degradation of a secondary battery, furthermore, the degree of positive degradation and the degree of negative degradation can each be diagnosed.

[0026] Furthermore, according to one aspect of the present invention, there is no need to store a large number of reference data or reference values ​​in a storage device such as a memory unit. Therefore, a high-capacity memory unit is not required, and the effort, time, and cost required to secure a large number of reference data or reference values ​​can be reduced.

[0027] In addition, according to one aspect of the present invention, differential profiles such as dV / dQ or dQ / dV may not be used when diagnosing the state of a secondary battery. Therefore, high performance or capacity of the processor, etc., is not required, and rapid computation may be possible. Brief explanation of the drawing

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention described above; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a block diagram schematically showing the functional configuration of a secondary battery diagnostic device according to one embodiment of the present invention. FIG. 2 is a graph showing an example of a positive reference profile and a negative reference profile stored in a memory unit according to an embodiment of the present invention. FIG. 3 is a graph showing an example of a charge / discharge measurement profile generated by a processor according to one embodiment of the present invention. FIG. 4 is a graph showing a comparison between a charge / discharge measurement profile and a simulation profile according to one embodiment of the present invention. FIG. 5 is a graph showing an example of a configuration in which a processor according to one embodiment of the present invention moves with respect to a reference profile. FIG. 6 is a graph showing an example of a configuration in which a processor according to one embodiment of the present invention scales with respect to a reference profile. FIG. 7 is a diagram illustrating a configuration in which an anode start value and a cathode start value are determined by a processor according to one embodiment of the present invention. FIG. 8 is a diagram illustrating a configuration in which the final anode value and the final cathode value are determined by a processor according to one embodiment of the present invention. FIG. 9 is a diagram showing a configuration for obtaining an anode adjustment profile and a cathode adjustment profile by adjusting an anode reference profile and a cathode reference profile by a processor according to one embodiment of the present invention. FIG. 10 is a graph showing the comparison of the positive reference profile and the negative reference profile with the positive adjustment profile and the negative adjustment profile by a processor according to one embodiment of the present invention. FIG. 11 is a graph schematically showing a configuration in which a simulation profile is moved in the vertical direction by a processor according to one embodiment of the present invention. Figure 12 is a graph showing an enlarged view of section B1 of Figure 11. FIG. 13 is a flowchart schematically illustrating a secondary battery diagnostic method according to one embodiment of the present invention. Specific details for implementing the invention

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0030] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0032] FIG. 1 is a block diagram schematically showing the functional configuration of a secondary battery diagnostic device according to one embodiment of the present invention.

[0033] Referring to FIG. 1, a secondary battery diagnostic device according to the present invention may include a memory unit (100), a voltage measurement unit (200), and a processor (300).

[0034] The memory unit (100) above may store a positive reference profile and a negative reference profile for the charging or discharging of a reference battery. Here, the reference battery may be a secondary battery of the same type as the secondary battery to be diagnosed, or a secondary battery designed to have the same characteristics. For such a reference battery, a positive profile and a negative profile may be extracted by undergoing a charging and / or discharging process in advance. At this time, the charging and discharging process may be performed at a C-rate identical or similar to the charging and discharging process performed by the voltage measurement unit (200) described later when measuring the voltage of the target battery. Then, the extracted profiles may be stored in the memory unit (100) as a positive reference profile and a negative reference profile. Here, to obtain the positive reference profile and the negative reference profile, the reference battery may be manufactured in a form such as a three-electrode cell or a coin half-cell, but the present invention is not necessarily limited to such a form.

[0035] FIG. 2 is a graph showing an example of a positive reference profile and a negative reference profile stored in a memory unit (100) according to an embodiment of the present invention.

[0036] Referring to FIG. 2, the memory unit (100) can store a positive reference profile (Rp) and a negative reference profile (Rn). At this time, the positive reference profile (Rp) and the negative reference profile (Rn) may be capacity-voltage graphs displayed on a coordinate system in which the horizontal axis represents capacity (Ah) and the vertical axis represents voltage (V). For example, the positive reference profile (Rp) may be a profile representing the positive voltage by capacity measured while charging a reference cell, such as a three-electrode cell or a positive half-cell. And, the negative reference profile (Rn) may be a profile representing the negative voltage by capacity measured while charging a reference cell, such as a three-electrode cell or a negative half-cell.

[0037] In particular, in the present invention, the memory unit (100) can store one positive reference profile (Rp) and one negative reference profile (Rn), respectively, as shown in FIG. 2. For example, the memory unit (100) can store one positive reference profile (Rp) and one negative reference profile (Rn) obtained while charging a reference battery. That is, the memory unit (100) may not store multiple positive reference profiles (Rp) and multiple negative reference profiles (Rn).

[0038] In addition to this, the memory unit (100) may further store data or programs necessary for other components of the secondary battery diagnostic device according to the present invention, such as a voltage measurement unit (200) or a processor (300), to perform operations or functions.

[0039] The memory unit (100) may be implemented as at least one of a flash memory type, a hard disk type, an SSD (Solid State Disk) type, an SSD (Solid Disk Drive) type, a multimedia card micro type, a RAM (Random Access Memory), a SRAM (Static RAM), a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory), and a PROM (Programmable Read Only Memory), but the present invention is not necessarily limited to the specific form of such a memory unit (100).

[0040] The voltage measuring unit (200) above may be configured to measure the voltage of the target battery during the charging or discharging process of the target battery. Here, the target battery refers to a battery that is subject to diagnosis. For example, the target battery may be a secondary battery before being shipped from a manufacturing plant, and it may be diagnosed whether there were defects during the manufacturing process or whether it was manufactured to have characteristics as designed. Alternatively, the target battery may be a secondary battery mounted in a battery pack, etc., and it may be diagnosed whether there are defects or how much degradation has occurred.

[0041] The voltage measuring unit (200) may be configured to measure the voltage while charging or discharging the target battery. In this case, the voltage measuring unit (200) may be configured to measure the charging voltage or the discharging voltage as is, rather than the Open Circuit Voltage (OCV) of the target battery. That is, the voltage measuring unit (200) may be configured to measure the Closed Circuit Voltage (CCV) of the target battery. In this case, the resistance characteristics of the target battery can be estimated more accurately. This will be described later.

[0042] The voltage measuring unit (200) above preferably measures the voltage of the target battery while performing a charge-discharge process at a C-rate that is the same or similar to the C-rate of the charge-discharge process performed to measure the positive reference profile (Rp) and negative reference profile (Rn) previously stored in the memory unit (100). In this case, misdiagnosis of the target battery due to a difference in C-rate can be prevented.

[0043] The above voltage measurement unit (200) may employ various voltage measurement technologies known at the time of filing the present invention. For example, the above voltage measurement unit (200) may be equipped with a voltage sensor known at the time of filing the present invention. In particular, when a secondary battery diagnostic device according to the present invention is applied to a battery pack, a voltage sensor already equipped in the battery pack may be used as the voltage measurement unit (200) according to the present invention.

[0044] The processor (300) can generate a charge / discharge measurement profile based on the voltage measured by the voltage measurement unit (200). That is, when the voltage is measured by the voltage measurement unit (200), the voltage measurement information can be transmitted from the voltage measurement unit (200) to the processor (300). Then, the processor (300) can generate a charge / discharge measurement profile for a target battery based on the voltage measurement information transmitted in this way. Here, the charge / discharge measurement profile may be a charge voltage profile measured during the charging process of the target battery, or a discharge voltage profile measured during the discharging process of the target battery.

[0045] FIG. 3 is a graph showing an example of a charge / discharge measurement profile generated by a processor (300) according to one embodiment of the present invention.

[0046] Referring to FIG. 3, the processor (300) can generate a graph representing the voltage by capacity of the target battery based on voltage value information measured during the charging or discharging process of the target battery. That is, the processor (300) can generate a charge / discharge profile representing the voltage change according to the capacity of the target battery on a coordinate system in which the horizontal axis (x-axis) represents the capacity of the battery and the vertical axis (y-axis) represents the voltage of the battery. For example, when the capacity of the target battery increases as 0, 5Ah, 10Ah, 15Ah, ... during the charging process of the target battery, the processor (300) can match the voltage measurement value received at each capacity to each capacity to derive a voltage change graph by capacity as indicated by M in FIG. 3. And, the voltage change graph by capacity derived in this way may be a charge / discharge measurement profile.

[0047] In particular, the charge / discharge measurement profile (M) generated by the processor (300) may be a profile that directly represents the charge voltage or discharge voltage according to the capacity of the target battery. That is, the charge / discharge measurement profile may not be an open circuit voltage (OCV) profile of the target battery, but a closed circuit voltage (CCV) profile directly measured during the charging or discharging process of the target battery.

[0048] Meanwhile, in the embodiments of FIGS. 2 and 3, the unit on the horizontal axis is indicated as Ah and the unit on the vertical axis is indicated as V, but these units may be expressed in other forms. For example, the unit of volume on the horizontal axis may be indicated as %.

[0049] In this way, when a charge / discharge measurement profile is generated, the processor (300) may be configured to compare the generated charge / discharge measurement profile with a simulation profile. Here, the simulation profile may be a full-cell voltage profile obtained from the positive reference profile and the negative reference profile stored in the memory unit (100). That is, as shown in FIG. 2, when the positive reference profile (Rp) and the negative reference profile (Rn) are stored in the memory unit (100), the difference between these positive reference profile (Rp) and the negative reference profile (Rn) may be the full-cell type charge / discharge voltage profile. And, the simulation profile may refer to the full-cell type charge / discharge voltage profile for the reference cell. Therefore, the simulation profile may appear in the form of a voltage graph by capacity, just like the positive reference profile (Rp) and the negative reference profile (Rn).

[0050] This simulation profile may be obtained in the form of being directly generated by the processor (300) using the positive reference profile (Rp) and the negative reference profile (Rn) stored in the memory unit (100). Alternatively, the simulation profile may be pre-calculated based on the positive reference profile (Rp) and the negative reference profile (Rn) and stored in the memory unit (100). In this case, the processor (300) may also obtain the simulation profile by accessing the memory unit (100) and reading it.

[0051] When a simulation profile is obtained in this manner, the processor (300) can compare the obtained simulation profile with the generated charge / discharge measurement profile. This will be explained in more detail with reference to FIG. 4.

[0052] FIG. 4 is a graph showing a comparison between a charge / discharge measurement profile (M) and a simulation profile (R) according to one embodiment of the present invention.

[0053] Referring to FIG. 4, a charge / discharge measurement profile generated by a processor (300) based on information transmitted by a voltage measurement unit (200) is indicated as M. And, a simulation profile obtained from a positive reference profile (Rp) and a negative reference profile (Rn) stored in a memory unit (100) is indicated as R. Here, the charge / discharge measurement profile (M) is a voltage profile by capacity measured from a secondary battery, i.e., a target battery, that is being diagnosed, and the simulation profile (R) can be said to be a profile of a reference battery that is stored in advance or obtained therefrom to be compared with the profile of the target battery.

[0054] Meanwhile, in FIG. 4, the positive reference profile (Rp) and the negative reference profile (Rn) are as shown in the embodiment of FIG. 2, and the simulation profile (R) can be obtained from the difference between these positive reference profile (Rp) and the negative reference profile (Rn). Also, the charge / discharge measurement profile (M) of FIG. 4 can be said to be as shown in FIG. 3.

[0055] As illustrated in FIG. 4, there may be a difference between the charge / discharge measurement profile (M) measured from the target battery and the previously acquired simulation profile (R). For example, the simulation profile (R) may be a form in which the charge or discharge curve of the secondary battery appears ideally as originally designed. And, the charge / discharge measurement profile (M) may be a form in which the charge or discharge curve of the secondary battery being manufactured or in use actually appears. The processor (300) may be configured to check for a difference between such a simulation profile (R) and a charge / discharge measurement profile (M).

[0056] In particular, if a secondary battery is used beyond a certain level, it may degrade, which may cause a change in the charge-discharge curve. Additionally, if defects occur during the manufacturing process of the secondary battery due to process errors, the charge-discharge curve may not appear as designed. The processor (300) can compare the charge-discharge measurement profile (M) with the simulation profile (R) to determine whether there is a difference between them, specifically whether it is within a certain error range.

[0057] Furthermore, the processor (300) may be configured to determine an anode adjustment profile and a cathode adjustment profile such that the error between the simulation profile (R) and the charge / discharge measurement profile (M) is within a certain level. As previously explained, the simulation profile (R) can first be obtained based on the anode reference profile (Rp) and the cathode reference profile (Rn). Therefore, adjusting the anode reference profile (Rp) and / or the cathode reference profile (Rp) can result in the simulation profile (R) also being adjusted. Thus, as shown in FIG. 4, if there is an error greater than a certain level between the simulation profile (R) and the charge / discharge measurement profile (M), the processor (300) can adjust the anode reference profile (Rp) and / or the cathode reference profile (Rn) so that this error is within a certain level. And, the finally adjusted anode reference profile (Rp) and cathode reference profile (Rp) can become the anode adjustment profile and the cathode adjustment profile. In particular, the processor (300) can determine the adjustment value of the positive reference profile (Rp) and the adjustment value of the negative reference profile (Rp) as the positive adjustment profile and the negative adjustment profile, respectively, in the case where the error between the simulation profile (R) and the charge / discharge measurement profile (M) is the smallest value among a plurality of cases in which the positive reference profile (Rp) and the negative reference profile (Rp) are adjusted.

[0058] Here, various methods known at the time of filing the present invention may be employed to determine whether the error between the simulation profile (R) and the charge / discharge measurement profile (M) is the smallest value by comparing the errors for the two graphs. In particular, the simulation profile (R) and the charge / discharge measurement profile (M) may be in the form of curves. Therefore, whether the error between the simulation profile (R) and the charge / discharge measurement profile (M) is the smallest value can be determined by, for example, by calculating the integral of the absolute value over the area between the two curves.

[0059] According to this configuration of the present invention, various state information regarding the target battery can be obtained based on the finally determined positive adjustment profile and negative adjustment profile. In particular, the simulation profile based on the finally determined positive adjustment profile and negative adjustment profile can be said to be almost identical in shape and other characteristics to the charge / discharge measurement profile (M). For convenience of explanation, the full cell voltage profile obtained by the positive adjustment profile and the negative adjustment profile is referred to as the simulation adjustment profile in order to compare it with the simulation profile (R), which is the full cell voltage profile obtained by the initial positive reference profile (Rp) and the negative reference profile (Rp).

[0060] Since the simulation adjustment profile may match or be similar to the charge / discharge measurement profile (M), the positive adjustment profile and the negative adjustment profile forming the simulation adjustment profile can be said to be the positive profile and the negative profile for the charge / discharge measurement profile (M). Therefore, according to the present invention, the positive profile and the negative profile for the target battery can be obtained without disassembling the target battery or without manufacturing it in the form of a three-electrode battery. Furthermore, when the positive profile and the negative profile are obtained in this way from the charge / discharge signal of the target battery, the state of the target battery can be more easily predicted using the positive profile and the negative profile.

[0061] In particular, according to one aspect of the present invention, the positive electrode adjustment profile and the negative electrode adjustment profile can be more easily utilized to predict whether a defect has occurred in a manufactured secondary battery, and if so, what type of defect it is. Furthermore, according to one aspect of the present invention, the positive electrode adjustment profile and the negative electrode adjustment profile can be easily utilized to estimate information regarding whether degradation has occurred in a secondary battery in use, and if so, to what extent or what type of degradation it is.

[0062] Furthermore, according to one embodiment of the present invention, the positive profile and the negative profile can be obtained in a simple manner. In particular, the present invention can be implemented even if only one positive reference profile (Rp) and one negative reference profile (Rn) are stored in the memory unit (100). That is, there is no need to store multiple positive reference profiles (Rp) and / or multiple negative reference profiles (Rn) in the memory unit (100). Therefore, the capacity of the memory unit (100) does not need to be high, and there is no need to conduct many preliminary tests to store the reference profiles.

[0063] Furthermore, according to one embodiment of the present invention, a closed voltage profile (CCV) is used instead of an open voltage profile (OCV). Accordingly, it becomes possible to measure changes in resistance during a continuous charging or discharging process. In particular, the open voltage profile may be obtained in the form of an intermediate value between the charging voltage profile and the discharging voltage profile, or it may be obtained by stopping the charging or discharging process and measuring the voltage after a certain period of time has elapsed with the battery terminals open. Therefore, in the case of such an open voltage profile, it may be difficult to accurately measure changes in resistance during a continuous charging or discharging process. However, according to the above embodiment of the present invention, by using a charging voltage profile or a discharging voltage profile measured while the charging or discharging current is flowing, rather than an open voltage profile, it becomes possible to accurately measure changes in resistance during a continuous charging or discharging process.

[0064] The above processor (300) is known in the art for executing various control logics performed in the present invention and may optionally include or be expressed by terms such as a central processing unit (CPU), an application-specific integrated circuit (ASIC), a chipset, a logic circuit, a register, a communication modem, a data processing device, etc. Additionally, when the control logic is implemented in software, the above processor (300) may be implemented as a set of program modules. In this case, the program modules may be stored in an internal memory or an external memory unit (100), etc., and may be executed by the processor (300). The above memory unit (100) may be located inside or outside the processor (300) and may be connected to the processor (300) by various well-known means.

[0065] In particular, when the secondary battery diagnostic device according to the present invention is implemented in a form included in a battery pack, the battery pack may include a control device referred to by terms such as an MCU (Micro Controller Unit) or a BMS (Battery Management System). In this case, the processor (300) may be implemented by a component such as an MCU or BMS provided in such a general battery pack.

[0066] Meanwhile, in this specification, terms such as ‘~does’ or ‘~is configured to’ regarding the operation or function of the processor (300), etc., may include the meaning of ‘~is programmed to’.

[0067] Preferably, the processor (300) may be configured to determine the anode adjustment profile and the cathode adjustment profile by moving the anode reference profile (Rp) and / or the cathode reference profile (Rn) on the coordinate axes. This will be explained in more detail with reference to FIG. 5.

[0068] FIG. 5 is a graph showing an example of a configuration in which a processor (300) according to one embodiment of the present invention moves with respect to a reference profile. The present embodiment and other embodiments below are described mainly with respect to parts that differ from the previously described embodiments, and detailed descriptions are omitted for parts to which the same or similar descriptions can be applied.

[0069] Referring to FIG. 5, as in FIG. 2, the positive reference profile and the negative reference profile stored in the memory unit (100) are labeled as Rp and Rn, respectively. Here, the positive reference profile (Rp) and the negative reference profile (Rn) may be represented in the form of voltages according to capacity.

[0070] The processor (300) can move horizontally with respect to at least one of the positive reference profile (Rp) and the negative reference profile (Rn). For example, the processor (300) can move the positive reference profile, indicated by Rp, in the direction of the -x axis as indicated by arrow A1. In this case, the positive reference profile can be displayed on the coordinate plane in a position and shape as indicated by Rp'. Additionally, the processor (300) can move the negative reference profile, indicated by Rn, in the direction of the -x axis as indicated by arrow A2. In this case, the negative reference profile can be displayed on the coordinate axis in a position and shape as indicated by Rn'.

[0071] In this way, when the processor (300) moves at least one of the positive reference profile (Rp) and the negative reference profile (Rn), the position and / or shape of the simulation profile indicated by R may change. Accordingly, the processor (300) may move the positive reference profile (Rp) and the negative reference profile (Rn) so that the position and / or shape of the adjusted simulation profile, i.e., the simulation adjustment profile, matches as closely as possible to the position and / or shape of the charge / discharge measurement profile (M). In FIG. 5, the shape of the positive reference profile before moving is indicated as Rp, and the shape after moving is indicated as Rp'. Also, the shape of the negative reference profile before moving is indicated as Rn, and the shape after moving is indicated as Rn'. And, if the simulation profile (R) is adjusted through the movement of these positive reference profile and negative reference profile so that it matches the charge / discharge measurement profile (M) or has an error within a certain level, the positive profile labeled Rp' and the negative profile labeled Rn' can be determined as the positive adjustment profile and the negative adjustment profile, respectively.

[0072] And, the positive adjustment profile (Rp') and negative adjustment profile (Rn') determined in this way can be said to represent the positive profile and negative profile for the charge / discharge measurement profile (M) of the target battery.

[0073] Meanwhile, in FIG. 5, the positive reference profile (Rp) and the negative reference profile (Rn) are described as moving in a horizontal direction (x-axis direction), but the positive adjustment profile (Rp') and the negative adjustment profile (Rn') may also be obtained by moving the positive reference profile (Rp) and the negative reference profile (Rn) in a vertical direction (y-axis direction) or a diagonal direction.

[0075] Additionally, the processor (300) may be configured to determine an anode adjustment profile (Rp') and a cathode adjustment profile (Rn') by scaling the anode reference profile (Rp) and / or cathode reference profile (Rn) in a coordinate system. This will be explained in more detail with reference to FIG. 6.

[0076] FIG. 6 is a graph showing an example of a configuration in which a processor (300) according to one embodiment of the present invention scales a reference profile.

[0077] Referring to FIG. 6, the processor (300) may be configured to scale the positive reference profile (Rp) stored in the memory unit (100) in a horizontal direction, that is, in the x-axis direction. In particular, the processor (300) may scale the positive reference profile (Rp) in a way that causes it to shrink, as indicated by arrow A3. Alternatively, the processor (300) may scale the positive reference profile (Rp) in a way that causes it to expand in the opposite direction of arrow A3. Such scaling can be described as horizontal scaling. In particular, since the positive profile (Rp) and / or negative profile (Rn) often shrink when the secondary battery degrades or is defective, the processor (300) may scale the positive reference profile (Rp) and / or negative reference profile (Rn) in a way that causes them to shrink.

[0078] More specifically, the processor (300) can move the point where the capacity is at maximum and the charge is at maximum in the horizontal direction A3, while keeping the point where the capacity is at maximum and the charge is at maximum in the positive reference profile indicated by Rp fixed. That is, the processor (300) can move the point (P1) corresponding to the charge end voltage (4.3V in the drawing) in the -x-axis direction while keeping the point corresponding to the charge start voltage (3.5 V in the drawing) fixed. And, through this end-part movement, the positive reference profile (Rp) can be contracted.

[0079] For example, if the anode reference profile Rp is contracted by 6%, the full charge voltage capacity can shift from point P1 to point P2. In this case, an anode adjustment profile Rp1' can be formed. Additionally, if the anode reference profile Rp is to be contracted by 8%, point P1 can be shifted to point P3. In this case, the anode adjustment profile can be formed as Rp2'. That is, based on Rp, Rp2' can be described as a profile that is more contracted than Rp1'.

[0080] The processor (300) may determine that the Rp1' profile is an anode adjustment profile if the error between the adjusted simulation profile (R) and the charge / discharge measurement profile (M), which are in a contracted state with respect to the anode reference profile Rp as Rp1', is within a certain level. On the other hand, the processor (300) may determine that the Rp2' profile is an anode adjustment profile if the error between the adjusted simulation profile (R) and the charge / discharge measurement profile (M), which are in a contracted state with respect to the anode reference profile Rp as Rp2', is within a certain level.

[0081] Meanwhile, in the embodiment of FIG. 6, a configuration for scaling the anode reference profile (Rp) is described, but the cathode reference profile (Rn) can also be scaled in a similar manner. Here, the scaling ratio of the cathode reference profile (Rn) can be configured to be the same as or different from the scaling ratio of the anode reference profile (Rp).

[0082] In particular, in the secondary battery diagnostic device according to the present invention, the processor (300) can determine the positive adjustment profile (Rp') and the negative adjustment profile (Rn') by performing a horizontal movement of the positive reference profile (Rp) and / or the negative reference profile (Rn) as shown in FIG. 5 and a horizontal scale adjustment of the positive reference profile (Rp) and / or the negative reference profile (Rn) as shown in FIG. 6, such as a reduction adjustment.

[0083] According to this embodiment of the present invention, a positive electrode profile and a negative electrode profile for a charge / discharge measurement profile (M) of a target battery can be obtained in a simple manner. In particular, according to the above embodiment of the present invention, there is no need to store a large amount of data for a positive electrode reference profile (Rp) and a negative electrode reference profile (Rn). Therefore, according to this aspect of the present invention, a high-capacity to high-performance memory unit (100) and a processor (300) may not be provided.

[0084] As in the above embodiment, when horizontal scaling of the positive reference profile (Rp) and / or negative reference profile (Rn), particularly shrinkage adjustment, is performed to minimize the error between the charge / discharge measurement profile (M) and the simulation profile (R), the processor (300) can estimate the positive degradation rate and / or negative degradation rate through these shrinkage values.

[0085] For example, to minimize the error between the charge / discharge measurement profile (M) and the simulation profile (R), if the anode reference profile (Rp) has a capacitance value of 100 [Ah] at the end-of-charge voltage and the anode adjustment profile (Rp') is obtained by shrinking the anode reference profile (Rp) by 3%, the capacitance value of the anode adjustment profile (Rp') at the end-of-charge voltage can be 97 [Ah]. In this case, the shrinkage value for the anode reference profile (Rp) can be said to be 3%. Therefore, the processor (300) can determine that the anode degradation rate is 3%.

[0086] In addition, to minimize the error between the charge / discharge measurement profile (M) and the simulation profile (R), if the cathode reference profile (Rn) is contracted by 0.1% to obtain a cathode adjustment profile (Rn') while the capacitance value at the charge end voltage of the cathode reference profile (Rn) is 100 [Ah], the capacitance value at the charge end voltage of the cathode adjustment profile (Rn') can be 99.9 [Ah]. In this case, the contraction value for the cathode reference profile (Rn) can be said to be 0.1%. Therefore, the processor (300) can determine that the cathode degradation rate is 0.1%.

[0087] Furthermore, the capacitance axis unit of the coordinate system showing the charge / discharge measurement profile (M) and the simulation profile (R) can be expressed in [%] units instead of [Ah]. In this case, the shrinkage value can be obtained more easily.

[0088] According to this embodiment of the present invention, the positive electrode degradation rate / negative electrode degradation rate can be obtained more clearly and simply through the degree of scaling, particularly the degree of shrinkage, of the positive electrode reference profile (Rp) and the negative electrode reference profile (Rn). In particular, during the manufacturing or use process, the capacity of a secondary battery may not be properly utilized due to the formation of a conductive path at a certain point, gas generation, or degradation of the active material. According to the above embodiment, through the adjustment of the shrinkage of the profile, positive electrode profiles and negative electrode profiles that substantially reflect such degradation can be obtained.

[0089] The voltage measuring unit (200) above may be configured to measure the full discharge voltage and full charge voltage of the target battery. Here, the full discharge voltage may refer to the voltage when the target battery is in a completely discharged state, that is, when the state of charge (SOC) of the target battery is 0. In particular, the full discharge voltage may be the open circuit voltage (OCV) when the SOC is 0. And, the full charge voltage may refer to the voltage when the target battery is in a fully charged state, that is, when the SOC of the target battery is 100%. In particular, the full charge voltage may be the open circuit voltage when the SOC is 100%.

[0090] The above processor (300) can estimate the positive initiation value of the positive adjustment profile or the negative initiation value of the negative adjustment profile based on the full discharge voltage. Here, the positive initiation value may be a point where the capacity is zero on the positive adjustment profile when the positive adjustment profile is determined by adjusting the positive reference profile. Also, the negative initiation value may be a point where the capacity is zero on the negative adjustment profile when the negative adjustment profile is determined by adjusting the negative reference profile. That is, the positive initiation value and the negative initiation value may be the starting point of the positive profile and the starting point of the negative profile when charging is started (full discharge) for the current target battery.

[0091] The above processor (300) arbitrarily sets at least one of the positive initiation value and the negative initiation value, and the other one can be obtained from the full discharge voltage. This will be explained in more detail with reference to FIG. 7.

[0092] FIG. 7 is a diagram illustrating a configuration in which an anode start value and a cathode start value are determined by a processor (300) according to one embodiment of the present invention.

[0093] The positive reference profile (Rp) and the negative reference profile (Rn) may be stored in the memory unit (100) in the form shown in FIG. 7. Alternatively, the positive reference profile (Rp) and the negative reference profile (Rn) of FIG. 7 may be adjusted reference profiles after a movement as in FIG. 5 and / or a contraction as in FIG. 6 have been performed with respect to the profiles stored in the memory unit (100).

[0094] And, the processor (300) may set any point on the positive reference profile (Rp), such as pi, as the positive start value. At this time, the positive start value may be stored in advance in the memory unit (100) or configured to be calculated by the processor (300) through a certain calculation method. For example, the positive start value may be configured to have a predetermined value by distinguishing whether the target battery is in a manufacturing state or in a usage state. Alternatively, the positive start value may be configured to have a predetermined value distinguished for each charge / discharge cycle for a battery in a usage state.

[0095] In this way, when the positive initiation value pi is set, the processor (300) can determine the negative initiation value based on the full discharge voltage measured by the voltage measurement unit (200). For example, when the full discharge voltage, i.e., the voltage when the SOC of the target battery is 0, is measured as V1, the processor (300) can search for a point on the negative reference profile (Rn) that has a difference from the positive initiation value and V1. In FIG. 7, the point that has a difference from the positive initiation value and V1 is indicated as ni. Then, the processor (300) can determine the point ni thus searched as the negative initiation value.

[0096] Additionally, the processor (300) may be configured to estimate the final positive value of the positive adjustment profile and the final negative value of the negative adjustment profile based on the full charge voltage. Here, the final positive value may be the point where the capacity is 100% on the positive adjustment profile when the positive adjustment profile is determined by adjusting the positive reference profile. Additionally, the final negative value may be the point where the capacity is 100% on the negative adjustment profile when the negative adjustment profile is determined by adjusting the negative reference profile. That is, the final positive value and the final negative value may be the end value of the positive profile and the end value of the negative profile when charging is terminated (fully charged) for the current target battery. This will be explained in more detail with reference to FIG. 8.

[0097] FIG. 8 is a diagram illustrating a configuration in which the final positive value and the final negative value are determined by a processor (300) according to one embodiment of the present invention.

[0098] Referring to FIG. 8, an anode reference profile (Rp) and a cathode reference profile (Rn) are shown. These anode reference profiles (Rp) and cathode reference profiles (Rn) may be profiles that are pre-stored in a memory unit, as described in FIG. 7, or profiles that have been moved and / or scaled from therein. Additionally, an anode start value (pi) and a cathode start value (ni) are respectively indicated on each reference profile. These anode start values ​​(pi) and cathode start values ​​(ni) can be obtained as described in FIG. 7. Once the anode start value (pi) and cathode start value (ni) are determined in this way, the processor (300) can obtain a straight line L1 connecting the anode start value (pi) and the cathode start value (ni).

[0099] And, the processor (300) can obtain another straight line L2 that is parallel to straight line L1 and whose two ends move along the positive reference profile (Rp) and the negative reference profile (Rn). The processor (300) can move this L2 in the left and right directions as indicated by A4 in the drawing. Here, when the full charge voltage of the target battery is transmitted as V2 from the voltage measuring unit (200), the processor (300) can move L2 as indicated by arrow A4 and search for a point where the voltage difference between the two ends is V2.

[0100] At this time, the processor (300) can maintain the parallel state with line L1 when line L2 moves. Also, the processor (300) can make both ends of line L2 move only on the positive reference profile (Rp) and the negative reference profile (Rn). That is, the processor (300) can make one end of line L2 move only on the positive reference profile (Rp), as indicated by arrow A5 in FIG. 8. Also, the processor (300) can make the other end of line L2 move only on the negative reference profile (Rn), as indicated by arrow A6 in FIG. 8. And, when the final position of a straight line L2 parallel to L1 and having a voltage difference of V2 at both ends is determined, the processor (300) can determine the end on the positive reference profile (Rp) as the positive final value (pf) and the end on the negative reference profile (Rn) as the negative final value (nf) for the straight line L2 at the final position.

[0101] And, once the anode starting value (pi), cathode starting value (ni), anode final value (pf), and cathode final value (nf) are determined in this manner, an anode adjustment profile and a cathode adjustment profile can be determined using the determined anode starting value (pi), cathode starting value (ni), anode final value (pf), and cathode final value (nf). This will be explained in more detail with reference to FIG. 9.

[0102] FIG. 9 is a diagram showing a configuration in which an anode reference profile (Rp) and a cathode reference profile (Rn) are adjusted by a processor (300) according to one embodiment of the present invention to obtain an anode adjustment profile (Rp') and a cathode adjustment profile (Rn').

[0103] Referring to FIG. 9, when the positive initiation value (pi), negative initiation value (ni), positive final value (pf), and negative final value (nf) are determined as described in the embodiments of FIG. 7 and FIG. 8, the positive adjustment profile (Rp') and negative adjustment profile (Rn') can be obtained based on these values.

[0104] More specifically, the positive adjustment profile (Rp') and the negative adjustment profile (Rn') can be displayed on a coordinate plane representing voltage by capacity, just like the positive reference profile (Rp) and the negative reference profile (Rn). And, the processor (300) can obtain the positive adjustment profile (Rp') by moving the positive reference profile (Rp) in a horizontal direction, particularly in the -x-axis direction, so that the positive initiation value (pi) is located on the y-axis. In addition, the processor (300) can obtain the negative adjustment profile (Rn') by adjusting the negative reference profile (Rn) in a similar manner. That is, the negative adjustment profile (Rn') can be obtained by moving the negative reference profile (Rn) in a horizontal direction, particularly in the -x-axis direction, so that the negative initiation value (ni) is located on the y-axis, that is, by moving the x-coordinate value of the negative initiation value (ni) so that the capacity becomes 0.

[0105] In this way, when the positive reference profile (Rp) and the negative reference profile (Rn) are changed, the full cell voltage profile obtained from the difference between the positive reference profile (Rp) and the negative reference profile (Rn) may also be changed. For example, when the full cell voltage profile appears as indicated by R in FIG. 8 before the positive reference profile and the negative reference profile are adjusted, if the positive reference profile and the negative reference profile are adjusted and their position and / or shape are changed, the full cell voltage profile may also be obtained in a different position and / or shape from the existing R, as indicated by R' in FIG. 9. And, if the full cell voltage profile obtained in this way matches the charge / discharge measurement profile (M) of the target battery or is within a certain error range, the processor (300) may determine the adjusted positive reference profile (Rp') as the positive adjustment profile and the adjusted negative reference profile (Rn') as the negative adjustment profile.

[0106] If, even after adjusting the positive reference profile and the negative reference profile in this manner, the full cell voltage profile (R') does not match the charge / discharge measurement profile (M) or falls outside the error range, the processor (300) may repeatedly perform the process described above with reference to the embodiments of FIGS. 7 to 9 with the positive initiation value (pi) changed to a different value. Alternatively, the processor (300) may additionally perform adjustments such as horizontal movement and / or shrinkage described above in FIGS. 5 and 6 on the adjusted positive profile (Rp') and the adjusted negative profile (Rn') obtained in FIG. 9.

[0107] And, by identifying the shape that most matches the charge / discharge measurement profile (M) among the full cell voltage profiles obtained through this iterative adjustment, the final positive adjustment profile and the final negative adjustment profile can be determined.

[0108] Additionally, the processor (300) can perform at least one of scale adjustment in the interval between the anode starting value (pi) and the anode final value (pf) for the anode adjustment profile and scale adjustment in the interval between the cathode starting value (ni) and the cathode final value (nf) for the cathode adjustment profile. And, through this, the processor (300) can be configured so that the error between the simulation profile (R) and the charge / discharge measurement profile (M) is within a certain level.

[0109] For example, the processor (300) can perform horizontal scale adjustment on the anode adjustment profile (Rp') shown in FIG. 9 in a manner such as shrinking it in the horizontal direction as described in FIG. 6. More specifically, the processor (300) can shrink or expand the anode adjustment profile (Rp') shown in FIG. 9 by moving the anode final value (pf) in the ±x-axis direction while keeping the anode starting value (pi) fixed on the voltage coordinate axis. In addition, the processor (300) can perform horizontal scale adjustment on the cathode adjustment profile (Rn') in a similar manner. That is, the processor (300) can shrink or expand the cathode adjustment profile (Rn') shown in FIG. 9 by moving the cathode final value (nf) in the ±x-axis direction while keeping the cathode starting value (ni) fixed on the voltage coordinate axis.

[0110] In addition, through such scaling, the simulation adjustment profile (R') and the charge / discharge measurement profile (M) can be made to match more closely. In particular, this scaling can be performed when a sufficiently satisfactory simulation adjustment profile is not obtained even through the horizontal movement of the anode reference profile and / or cathode reference profile described above, or when one wishes to obtain a simulation adjustment profile (R') that has higher agreement with the charge / discharge measurement profile (M).

[0111] Meanwhile, such scale adjustment may be performed without being limited to the interval between the anode start value (pi), anode end value (pf), cathode start value (ni), and cathode end value (nf). In particular, the processor (300) may perform scale adjustment first before determining the anode start value (pi), anode end value (pf), cathode start value (ni), and cathode end value (nf). For example, the processor (300) may scale the anode reference profile and / or cathode adjustment profile first before determining the anode start value (pi) and cathode start value (ni) in the embodiment graph of FIG. 7. Then, the processor (300) may determine the anode start value (pi), anode end value (pf), cathode start value (ni), and cathode end value (nf) for the profile that has undergone such scale adjustment.

[0112] According to this embodiment of the present invention, by obtaining only the charge / discharge measurement profile (M) of the target battery, the positive and negative profiles for the charge / discharge of the target battery can be obtained through a relatively simple process of shifting and / or scaling one previously stored positive reference profile and one negative reference profile. Furthermore, through these positive and negative profiles, various information regarding the state of the target battery can be obtained.

[0113] In particular, in the case of this embodiment, when obtaining the positive and negative profiles, complex calculations or operations are not required with capacitance-derivative curves such as dV / dQ or dQ / dV (where Q is capacitance and V is voltage).

[0114] Furthermore, in the case of the present invention, it may be possible to determine the state and characteristics of the secondary battery at a specific point in time, particularly in the BOL state. In addition, in the case of the present invention, it may be possible to determine the state and characteristics of the secondary battery during the manufacturing process or in use.

[0115] The above processor (300) may be configured to determine the capacity of the target battery based on the difference between the positive final value (pf) and the positive initial value (pi). Here, the difference between the positive final value and the positive initial value (pf-pi) may be equal to the difference between the negative final value and the negative initial value (nf-ni). Therefore, it may be said that the above processor (300) determines the capacity of the target battery based on the difference between the negative final value and the negative initial value (nf-ni).

[0116] In particular, the processor (300) can obtain the difference between the final anode value and the anode start value (pf-pi), or the difference between the cathode start value and the cathode start value (nf-ni), as a percentage. For example, the difference between the final estimated anode value and the anode start value (pf-pi) can be expressed as a percentage when compared to a reference capacity. Here, the reference capacity may be a value stored in advance in a memory unit (100), etc., as a value to be compared with the difference between the final estimated anode value and the anode start value (pf-pi).

[0117] As a more specific example, if the reference capacity is 60 Ah and the difference (pf-pi) between the finally estimated anode final value and the anode initial value is 55 Ah, to express this as a percentage, it can be calculated as (55 / 60)×100 = 92. In this case, the difference (pf-pi) between the anode final value and the anode initial value can be said to be 92%.

[0118] As another example, in a voltage graph by capacity that is used or generated by the processor (300), if the unit of the capacity axis is %, the processor (300) can calculate the difference (pf-pi) between the final anode value and the initial anode value from the finally obtained anode adjustment profile. For instance, in FIG. 9, when the capacity axis is displayed in % units rather than Ah units, the x-coordinate value of the final anode value (pf) can be said to be a value expressed as a percentage of the difference (pf-pi) between the final anode value and the initial anode value. That is, if the x-coordinate value of the final anode value (pf) in FIG. 9 is 91%, the processor (300) can obtain the difference (pf-pi) between the final anode value and the initial anode value as 91%.

[0119] In this way, when the difference between the final positive value and the initial positive value (pf-pi), or the difference between the final negative value and the initial negative value (nf-ni), is obtained, the processor (300) can calculate the capacity of the electrode based on these difference values. In particular, the influence on the capacity of the battery may be greater for the positive electrode than for the negative electrode. Accordingly, the processor (300) can calculate the capacity of the target battery in its current state using the following formula based on the difference between the final positive value and the initial positive value.

[0120] Capacity = a × PL × PA

[0121] Here, a is a value representing the difference (pf-pi) between the final anode value and the initial anode value, and can be expressed as a percentage (%) converted to a decimal unit. For example, if the difference between the final anode value and the initial anode value is 90%, a can be substituted as 0.9 into the above formula.

[0122] And, PL represents the loading value of the active material for the anode, 3 [mAh / cm² 2 It can be expressed in units representing the capacity-to-area ratio, such as ]. In addition, PA represents the total area of ​​the positive electrode included in a single battery, [cm 2 It can be expressed in units such as ].

[0123] These PL and PA values ​​may be values ​​that are stored in advance in the memory unit (100). Accordingly, the processor (300) can access the memory unit (100) to read the PL and PA values. And, as previously described, a can be obtained by the processor (300). Therefore, when the values ​​of a, PL, and PA are obtained in this way, the processor (300) can calculate the capacity of the target battery in its current state based on these values.

[0124] For example, a is 0.9 and PL is 3 [mAh / cm 2 ] and PA is 20000 [cm 2 In the case of ], the processor (300) can estimate the capacity of the target battery through the following calculation formula.

[0125] Capacity = 0.9 × 3 × 20000 = 54000 [mAh] = 54 [Ah]

[0126] In this case, the processor (300) can estimate that the current capacity of the target battery is 54 [Ah].

[0127] And, when the capacity of the target battery is calculated in this manner, the processor (300) can compare the calculated capacity with a reference capacity stored in the memory unit (100), etc. In particular, when diagnosing the state of a battery in a BOL state, the processor (300) can check whether the calculated capacity has a value similar to the designed capacity. And, through this check, the processor (300) can determine whether the target battery or the batteries currently being manufactured have been manufactured to have the designed performance.

[0128] That is, the processor (300) can determine whether the target battery is defective or the degree of degradation by comparing the estimated capacity in this way with the design capacity stored in advance. For example, if the design capacity stored in the memory unit (100) is 54 Ah, the processor (300) can determine that the target battery is in good condition because it has obtained a calculated capacity value that matches the design capacity. On the other hand, if the design capacity stored in the memory unit (100) is 60 Ah, there is a difference from the calculated capacity of 54 Ah, so the processor (300) can determine that the target battery is defective or has undergone significant degradation. According to this configuration of the present invention, verification of the capacity of the target battery can be performed easily and simply.

[0129] The above processor (300) may be configured to identify an anode unused area and / or cathode unused area of ​​a target battery based on an anode adjustment profile and a cathode adjustment profile. This will be explained in more detail with reference to FIG. 10.

[0130] FIG. 10 is a graph showing the comparison of the positive reference profile and the negative reference profile with the positive adjustment profile and the negative adjustment profile by a processor (300) according to one embodiment of the present invention.

[0131] Referring to FIG. 10, profile Rp represents an anode reference profile stored in the memory unit (100), and profile Rn represents a cathode reference profile stored in the memory unit (100). Additionally, profile Rp' can be described as an anode adjustment profile obtained during the process of matching the simulation profile (R) to the charge / discharge measurement profile (M) as much as possible by the processor (300). Furthermore, profile Rn' can be described as a cathode adjustment profile obtained during the process of matching the simulation profile (R) to the charge / discharge measurement profile (M) as much as possible by the processor (300).

[0132] The processor (300) can identify an anode unused area by checking how much a point with a capacitance of 0 in the anode reference profile (Rp) has moved in the direction of the capacitance axis (-x axis) in the anode adjustment profile (Rp'). Additionally, the processor (300) can identify a cathode unused area by checking how much a point with a capacitance of 0 in the cathode reference profile (Rn) has moved in the direction of the capacitance axis (-x axis) in the cathode adjustment profile (Rn').

[0133] More specifically, in FIG. 10, it can be confirmed that the point where the capacity is 0 in the positive reference profile (Rp) has moved to the left (-x-axis direction) by Gp in the positive adjustment profile (Rp'). In this case, the processor (300) can determine that an unused positive region of Gp [Ah] has occurred for the target battery. Additionally, it can be confirmed that the point where the capacity is 0 in the negative reference profile (Rn) has moved to the left by Gn in the negative adjustment profile (Rn'). In this case, the processor (300) can determine that an unused negative region of Gn [Ah] has occurred for the target battery.

[0134] According to this configuration of the present invention, the unused positive and negative regions of the target battery can be simply and accurately identified through a comparison between a reference profile and an adjustment profile. Furthermore, according to this aspect, the usage region of the target battery can be easily identified.

[0135] The processor (300) may be configured to reduce the error with the charge / discharge measurement profile (M) by moving the simulation profile (R) in the vertical direction. That is, as previously described, even after performing adjustments such as movement and / or contraction with respect to the positive reference profile and / or negative reference profile so that the adjusted simulation profile (R') has a small error with respect to the charge / discharge measurement profile (M), the processor (300) may move the adjusted simulation profile (R) in the vertical direction to further reduce the error. That is, the processor (300) may perform a secondary adjustment process of moving the simulation profile, which has been primarily adjusted through the movement and / or scale adjustment of the reference profile, again in the vertical direction. This will be explained in more detail with reference to FIG. 11.

[0136] FIG. 11 is a graph schematically showing a configuration in which a simulation profile (R) is moved in the up and down direction by a processor (300) according to one embodiment of the present invention.

[0137] Referring to FIG. 11, as previously explained, a simulation profile can be primarily obtained based on the anode adjustment profile and the cathode adjustment profile. This is indicated as R1' in FIG. 11 and is referred to as the simulation primary adjustment profile. This simulation primary adjustment profile (R1') can be obtained from the anode primary adjustment profile and the cathode primary adjustment profile obtained through the processes described previously, such as horizontal shifting, scaling (shrinking), and determining pi, pf, ni, and nf, with respect to the anode reference profile and / or the cathode reference profile. More specifically, the simulation primary adjustment profile (R1') may be a full cell voltage profile obtained from the difference between the anode primary adjustment profile and the cathode primary adjustment profile.

[0138] That is, this simulation primary adjustment profile (R1') can be said to be a value in which the error with the charge / discharge measurement profile (M) is minimized through the adjustment of the positive reference profile and / or the negative reference profile. However, there may be cases in which the error with the charge / discharge measurement profile (M) is further reduced by moving the simulation primary adjustment profile (R1') in an upward or downward direction (movement in the y-axis direction). The processor (300) may be configured to search for cases in which the error with the charge / discharge measurement profile (M) is further reduced by moving the simulation primary adjustment profile (R1') in the up and down direction.

[0139] For example, the processor (300) can obtain a profile as indicated by R2' by moving the simulation primary adjustment profile (R1') in the configuration of FIG. 11 parallel in the upward direction. If the error between this profile R2' and the charge / discharge measurement profile (M) is lower than that between this profile R1' and the processor (300), then this profile R2' can be referred to as a secondary adjusted simulation profile, i.e., a simulation secondary adjustment profile.

[0140] In this way, when a simulation second adjustment profile (R2') is detected by shifting the simulation first adjustment profile (R1') in the y-axis direction to further reduce the error with the charge / discharge measurement profile (M), the processor (300) may be configured to determine whether the internal resistance of the target battery has increased by considering the result of this shift. That is, the processor (300) can determine the change in the internal resistance of the target battery based on how much the simulation second adjustment profile (R2') has shifted in the upward direction from the simulation first adjustment profile (R1'). This will be explained in more detail with reference to FIG. 12.

[0141] FIG. 12 is a graph showing an enlarged view of section B1 of FIG. 11. However, for the convenience of explanation, FIG. 12 shows the capacitance axis and voltage axis corresponding to section B1 of FIG. 11 together.

[0142] Referring to FIG. 12, a simulation second adjustment profile (R2') can be obtained by moving the simulation first adjustment profile (R1') parallel to the direction of arrow A7, that is, the upward direction. At this time, the degree of movement in the upward direction is calculated as 4.120 - 4.104 = 0.016, and 0.016 [V] can be obtained. Therefore, it can be said that the processor (300) obtained the simulation second adjustment profile (R2') by moving the simulation first adjustment profile (R1') in the upward direction by 0.016 V, that is, 16 mV.

[0143] In this case, the processor (300) can determine that the magnitude of the voltage increase due to the increase in the internal resistance of the target battery is 16 mV, which is the magnitude of the upward shift. That is, if the internal resistance of the secondary battery increases, it can lead to an increase in overvoltage, and the processor (300) can determine how much the overvoltage of the target battery has increased through the parallel shift adjustment value of the simulation profile. That is, in the above embodiment, the processor (300) can determine that the internal resistance of the target battery has increased to the extent that the overvoltage increases by 16 mV. In particular, the processor (300) can determine that the internal resistance of the target battery has increased when the simulation first adjustment profile (R1') is shifted upward to obtain the simulation second adjustment profile (R2'). On the other hand, if the simulation first adjustment profile (R1') is moved downward to obtain the simulation second adjustment profile (R2'), the processor (300) can determine that the internal resistance of the target battery has decreased.

[0144] Furthermore, the processor (300) can easily determine the extent of capacity loss when the voltage rises due to this increase in internal resistance. In particular, the processor (300) can determine the capacity loss of the target battery through the difference in capacity at the point where the simulation first adjustment profile (R1') and the simulation second adjustment profile (R2') reach a preset charging end voltage.

[0145] For example, in the embodiment of FIG. 12, when the charging end voltage of the target battery is 4.2 V, the processor (300) can search for points where the charging end voltage is 4.2 V in the simulation first adjustment profile (R1') and the simulation second adjustment profile (R2'), respectively. In FIG. 12, these points are labeled as Pr1 and Pr2, respectively. Then, the processor (300) can check the capacity values ​​of these points Pr1 and Pr2, respectively. In FIG. 12, the capacity value of Pr1 can be confirmed as 58 Ah, and the capacity value of Pr2 can be confirmed as 56 Ah. In this case, the processor (300) can determine that the difference of 2 Ah between Pr1 and Pr2 is a capacity loss value due to an increase in internal resistance of the target battery.

[0146] If, in the embodiment of FIG. 12, the capacity axis (x-axis) is displayed in % units, the processor (300) can immediately extract the capacity loss value due to the increase in internal resistance in % units. For example, if the x-coordinate value of Pr1 is 94% and the x-coordinate value of Pr2 is 93%, the processor (300) can determine the capacity loss value due to the increase in internal resistance of the target battery as 1% by calculating it as 94 - 93 = 1. In this case, the processor (300) can predict that the target battery will terminate 1% earlier due to the increase in internal resistance.

[0147] According to this embodiment of the present invention, by adjusting the simulation profile, it is possible to easily determine whether the internal resistance of the target battery increases and the resulting degree of overvoltage increase or capacity loss.

[0148] The secondary battery diagnostic device according to the present invention may be applied to a battery pack. That is, the battery pack according to the present invention may include the secondary battery diagnostic device according to the present invention described above. In addition, the battery pack according to the present invention may further include components typically included in a battery pack, such as one or more secondary batteries, a Battery Management System (BMS), a current sensor, a relay, a fuse, a pack case, etc., in addition to the secondary battery diagnostic device according to the present invention. In this case, the secondary battery included in the battery pack may be the target, i.e., the target battery, that is, the secondary battery being diagnosed by the secondary battery diagnostic device according to the present invention. Furthermore, at least some components of the secondary battery diagnostic device according to the present invention may be implemented by conventional components included in the battery pack. For example, the voltage measurement unit (200) of the secondary battery diagnostic device according to the present invention may be implemented by a voltage sensor included in the battery pack. In addition, at least some functions or operations of the processor (300) of the secondary battery diagnostic device according to the present invention may be implemented by a BMS included in the battery pack.

[0149] Furthermore, the secondary battery diagnostic device according to the present invention may be applied to an automobile. That is, the automobile according to the present invention may include the secondary battery diagnostic device according to the present invention described above. In particular, in the case of an electric vehicle, since the battery pack is a very important component as a driving source, the secondary battery diagnostic device according to the present invention may be applied more usefully. In addition, the automobile according to the present invention may further include various other devices in addition to this secondary battery diagnostic device, such as a vehicle body, a vehicle control unit such as an ECU, a motor, a connection terminal, a DC-DC converter, etc. Furthermore, it goes without saying that the automobile according to the present invention may further employ components that are conventionally included in an automobile.

[0150] FIG. 13 is a flowchart schematically illustrating a secondary battery diagnostic method according to an embodiment of the present invention. In FIG. 13, the subject of each step may be each component of the secondary battery diagnostic device according to the present invention described above.

[0151] Referring to FIG. 13, the secondary battery diagnostic method according to the present invention may include a reference profile storage step (S110), a charge / discharge voltage measurement step (S120), a charge / discharge measurement profile generation step (S130), a simulation profile and a charge / discharge measurement profile comparison step (S140); and a positive adjustment profile and a negative adjustment profile determination step (S150).

[0152] The above step S110 is a step of storing a positive reference profile and a negative reference profile for charging or discharging a reference cell.

[0153] The above step S120 is a step of measuring the voltage while charging or discharging the target battery.

[0154] The above step S130 is a step of generating a charge / discharge measurement profile (M) based on the voltage measured in the above step S120.

[0155] The above step S140 is a step of comparing the simulation profile obtained from the positive reference profile and the negative reference profile stored in the above step S110 with the charge / discharge measurement profile generated in the above step S130.

[0156] The above step S150 is a step of determining an anode adjustment profile and a cathode adjustment profile such that the error between the simulation profile and the charge / discharge measurement profile is within a certain level, if it is determined through the comparison in the above step S140 that an error of more than a certain level exists between the simulation profile and the charge / discharge measurement profile.

[0157] For these steps S110 through S150, the contents of the secondary battery diagnostic device according to the present invention described above may be applied in the same or similar manner. Therefore, a more detailed description of each step of the secondary battery diagnostic method according to the present invention is omitted.

[0159] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0160] 100: Memory Unit 200: Voltage measuring unit 300: Processor Rp: Anode reference profile Rn: Cathode reference profile Rp': Bipolar adjustment profile Rn': Cathode adjustment profile

Claims

Claim 1 A secondary battery diagnostic device characterized by comprising: a memory unit storing a positive reference profile and a negative reference profile for charging or discharging a reference battery; and a processor configured to generate a charge / discharge measurement profile based on a voltage measured for a target battery during a charging or discharging process, compare a simulation profile obtained from the positive reference profile and negative reference profile stored in the memory unit with the generated charge / discharge measurement profile, and determine a positive adjustment profile and a negative adjustment profile such that the error between the simulation profile and the charge / discharge measurement profile is within a certain level by adjusting at least one of the positive reference profile and the negative reference profile, and to diagnose the target battery based on the determined positive adjustment profile and negative adjustment profile. Claim 2 A secondary battery diagnostic device according to claim 1, wherein the processor is configured to determine the positive adjustment profile and the negative adjustment profile by moving at least one of the positive reference profile and the negative reference profile in a horizontal direction. Claim 3 A secondary battery diagnostic device according to claim 1, wherein the processor is configured to determine the positive adjustment profile and the negative adjustment profile by scaling at least one of the positive reference profile and the negative reference profile in a horizontal direction. Claim 4 The secondary battery diagnostic device according to claim 1 further comprises a voltage measuring unit configured to measure the voltage of the target battery during a charging or discharging process, wherein the voltage measuring unit is configured to measure the full discharge voltage and full charge voltage of the target battery, and wherein the processor is configured to estimate the positive initiation value of the positive adjustment profile or the negative initiation value of the negative adjustment profile based on the full discharge voltage measured by the voltage measuring unit, and to estimate the positive final value of the positive adjustment profile and the negative final value of the negative adjustment profile based on the full charge voltage measured by the voltage measuring unit. Claim 5 A secondary battery diagnostic device according to claim 4, characterized in that the processor is configured to determine the capacity of the target battery based on the difference between the positive final value and the positive starting value or the difference between the negative final value and the negative starting value. Claim 6 A secondary battery diagnostic device according to claim 1, characterized in that the processor is configured to identify the positive unused area and the negative unused area of ​​the target battery based on the positive adjustment profile and the negative adjustment profile. Claim 7 A secondary battery diagnostic device according to claim 1, characterized in that the processor is configured to determine whether the internal resistance of the target battery increases by using the result of the parallel shift when the error with the charge / discharge measurement profile is reduced by moving the simulation profile in the vertical direction. Claim 8 A battery pack comprising a secondary battery diagnostic device according to any one of claims 1 to 7. Claim 9 An automobile comprising a secondary battery diagnostic device according to any one of paragraphs 1 through 7. Claim 10 A secondary battery diagnostic method characterized by comprising: a step of storing a positive reference profile and a negative reference profile for charging or discharging a reference battery; a step of generating a charge / discharge measurement profile based on a voltage measured for a target battery during a charging or discharging process; a step of comparing a simulation profile obtained from the positive reference profile and negative reference profile stored in the storage step with the charge / discharge measurement profile generated in the generation step; a step of determining a positive adjustment profile and a negative adjustment profile by adjusting at least one of the positive reference profile and the negative reference profile so that the error between the simulation profile and the charge / discharge measurement profile is within a certain level; and a step of diagnosing the target battery based on the positive adjustment profile and the negative adjustment profile determined in the determination step.

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