Battery diagnosis device and battery diagnosis method

Abstract

The invention discloses a battery diagnosis apparatus and a battery diagnosis method. The battery diagnosis apparatus includes: a data obtaining unit configured to obtain a first curve representing a capacity-voltage relationship of a battery cell including an active material having a multiphase characteristic; and a processor configured to generate a plurality of comparison curves based on the plurality of electrode curves included in the electrode graph. The processor is configured to select one of the plurality of comparison curves as a second curve by comparing each of the plurality of comparison curves with the first curve, and determine a positive electrode load amount representing a degradation state of the battery cell as a diagnostic factor based on the second curve.

Description

Technical Field

[0001] This disclosure relates to techniques for non-destructively diagnosing the state of a battery.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0182340, filed on December 14, 2023, the disclosure of which is incorporated herein by reference. Background Technology

[0003] Recently, there has been a rapid increase in demand for portable electronic products such as laptops, cameras and mobile phones, and with the widespread development of electric vehicles, energy storage devices, robots and satellites, there is a lot of research being done on high-performance batteries that can be repeatedly recharged.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have little or no memory effect, so they receive more attention than nickel-based batteries because their advantages are that they can be recharged whenever convenient, have a very low self-discharge rate, and high energy density.

[0005] While much research has been conducted on these batteries in terms of increasing capacity and density, improvements in lifespan and safety are also important. To improve battery safety, it is essential to accurately diagnose the current state of the battery.

[0006] Accurate diagnosis of the internal condition of individual battery cells is crucial for safety and long lifespan. To diagnose the internal condition of individual battery cells without disassembly, relational data showing the correspondence between full-cell capacity and full-cell voltage is primarily used (which may be referred to as a full-cell profile, etc.).

[0007] Conventionally, the degradation state of each electrode in a battery cell is diagnosed by analyzing the cell's relational data. This conventional diagnostic method is only considered valid if the overall curve of each electrode in the battery cell remains almost identical to that when the battery cell was released, even if the battery cell has deteriorated since then.

[0008] However, in the case of some types of battery cells, including positive and / or negative electrodes with multiphase characteristics where at least two phases coexist, the multiphase characteristics change as the battery cell deteriorates, and therefore, the overall design of electrodes with multiphase characteristics may be significantly distorted from the time of release. Consequently, if conventional diagnostic methods are applied to battery cells with multiphase characteristics, the accuracy of diagnosing the degradation state of each electrode may be greatly degraded. Summary of the Invention

[0009] Technical issues This disclosure is designed to address problems in the related art, and therefore aims to provide a battery diagnostic apparatus and a battery diagnostic method that can determine at least one diagnostic factor related to the degradation state of a battery cell containing an active material having multiphase properties in at least one of the positive and negative electrodes.

[0010] These and other objects and advantages of this disclosure may be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of this disclosure. Moreover, it will be readily understood that the objects and advantages of this disclosure can be achieved by the means and combinations thereof shown in the appended claims.

[0011] Technical solution In one aspect of this disclosure, a battery diagnostic apparatus is provided, comprising: a data acquisition unit configured to acquire a first curve representing the capacity-voltage relationship of a single battery cell, the battery cell including an active material having multiphase characteristics; and a processor configured to generate a plurality of comparison curves based on a plurality of electrode curves included in an electrode curve plot. The processor is configured to select one comparison curve from the plurality of comparison curves as a second curve by comparing each of the plurality of comparison curves with the first curve; and to determine the positive electrode loading as a diagnostic factor representing the degradation state of the battery cell based on the second curve.

[0012] The electrode profile may include multiple reference cathode profiles associated with multiple degradation states of the cathode of a single cell. Active materials with multiphase properties may be included in the cathode of the single cell. Each of at least two of the multiple reference cathode profiles may be a degradation cathode profile representing the capacity-voltage relationship of the cathode half-cell.

[0013] The processor can be configured to determine a comparison value based on at least two reference positive electrode curves. This comparison value can be greater than a threshold.

[0014] Electrode profiles may include multiple reference negative electrode profiles associated with multiple degradation states of the negative electrode of a battery cell. Active materials with multiphase properties may be included in the negative electrode of the battery cell.

[0015] Each of at least two of the multiple reference negative electrode curves may be a degraded negative electrode curve representing the capacity-voltage relationship of the negative electrode half-cell.

[0016] The processor can be configured to determine the comparison value based on at least two reference negative pole curves. The comparison value can be greater than a threshold.

[0017] The processor can be configured to generate multiple comparison curves by performing adjustment operations for each of multiple electrode curves based on multiple adjustment levels.

[0018] The adjustment operation may include at least one of scaling or shifting operations based on the capacity relationship values ​​of individual battery cells.

[0019] The processor can be configured to determine multiple comparison values ​​by comparing each of a plurality of comparison curves with a first curve. The second curve can be associated with the minimum comparison value among the plurality of comparison values.

[0020] The processor can be configured to generate curve adjustment data associated with the second curve. The curve adjustment data may include at least one of positive electrode state data based on the adjusted positive electrode curve and negative electrode state data based on the adjusted negative electrode curve. The adjusted positive and negative electrode curves can be generated by adjusting two of a plurality of electrode curves. The adjusted positive and negative electrode curves can be used to generate the second curve.

[0021] The processor can generate a second curve based on voltage difference data representing the voltage difference between the adjusted positive curve and the adjusted negative curve.

[0022] The positive electrode state data may include the positive electrode load, and may also include at least one of the following: positive electrode participation start point, positive electrode participation end point, and positive electrode scaling factor.

[0023] Negative electrode status data may include at least one of the following: negative electrode participation start point, negative electrode participation end point, negative electrode scaling factor, and negative electrode load.

[0024] The processor can be configured to limit at least one of the voltage range and state of charge (SOC) range of a battery cell based on diagnostic factors.

[0025] In another aspect of this disclosure, a battery pack is also provided, which includes a battery diagnostic device.

[0026] In another aspect of this disclosure, a battery system is also provided, which includes a battery pack.

[0027] In another aspect of this disclosure, a remote diagnostic server is also provided, which includes a battery diagnostic device.

[0028] In another aspect of this disclosure, a battery diagnostic method is also provided, comprising: obtaining a first curve representing the capacity-voltage relationship of a battery cell, the battery cell comprising an active material having multiphase characteristics; generating a plurality of comparison curves based on a plurality of electrode curves included in an electrode curve plot; selecting one of the plurality of comparison curves as a second curve by comparing each of the plurality of comparison curves with the first curve; and determining the positive electrode loading as a diagnostic factor representing the degradation state of the battery cell based on the second curve.

[0029] In another aspect of this disclosure, a computer-readable medium is also provided for storing instructions for diagnosing a battery cell. When executed by one or more processors, the instructions cause the one or more processors to perform operations including: obtaining a first curve representing the capacity-voltage relationship of a battery cell, the battery cell comprising an active material having multiphase characteristics; generating a plurality of comparison curves based on a plurality of electrode curves included in an electrode curve plot; selecting one of the plurality of comparison curves as a second curve by comparing each of the plurality of comparison curves with the first curve; and determining the positive electrode loading as a diagnostic factor representing the degradation state of the battery cell based on the second curve.

[0030] Beneficial effects According to at least one embodiment of the present disclosure, at least one diagnostic factor related to the degradation state of a battery cell containing an active material having multiphase properties can be accurately determined.

[0031] Furthermore, according to at least one embodiment of the present disclosure, based on at least one diagnostic factor, at least one degradation parameter indicating the degradation state of the positive electrode, negative electrode, and / or available lithium of a battery cell can be determined.

[0032] Furthermore, according to at least one embodiment of this disclosure, the permissible operating conditions (e.g., voltage range, SOC range, current, etc.) of a battery cell can be adjusted (limited) based on the diagnostic results of the battery cell, thereby achieving the safety and long lifespan of the battery cell.

[0033] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand these and other effects from the appended claims. Attached Figure Description

[0034] The accompanying drawings illustrate preferred embodiments of the present disclosure and are used together with the foregoing disclosure to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings.

[0035] Figure 1 The diagram illustrates, exemplarily, a battery diagnostic device, a battery system, and a charging station according to embodiments of the present disclosure.

[0036] Figure 2 and Figure 3 This is a reference graph describing the capacity-voltage relationship of an electrode that does not have multiphase characteristics.

[0037] Figure 4 and Figure 5 This is a reference graph describing the capacity-voltage relationship of an electrode with multiphase characteristics.

[0038] Figures 6 to 9This is a graph used as a reference for the electrode curves described in the diagnosis of battery cells with multiphase characteristics.

[0039] Figure 10 This is a graph used to describe an example of each of the reference positive and reference negative electrode curves.

[0040] Figure 11 and 12 This is an exemplary diagram illustrating the measurement of the full-cell curve.

[0041] Figures 13 to 15 This is a reference diagram illustrating an example of the process of generating curve adjustment result information using curve adjustment logic.

[0042] Figures 16 to 18 The referenced diagram is another example illustrating the process of generating curve adjustment result information using curve adjustment logic.

[0043] Figure 19 This is a flowchart illustrating a battery diagnostic method according to another embodiment of the present disclosure.

[0044] Figure 20 It is a description that can be found Figure 19 The diagram referenced in the method shown shows the open-circuit voltage (OCV) estimation process performed. Detailed Implementation

[0045] The subject matter of this specification will be described more fully below with reference to the accompanying drawings, which form part of this specification and illustrate specific exemplary embodiments by way of example. The embodiments or implementations described herein as “exemplary” should not be construed as preferred or advantageous over other embodiments or implementations; rather, they are intended to reflect or indicate that the embodiments are “example” embodiments. The subject matter can be embodied in a variety of different forms, and therefore, the covered or claimed subject matter should not be construed as limited to any of the exemplary embodiments described herein; the exemplary embodiments are for illustrative purposes only. Similarly, a reasonably broad scope is contemplated for the claimed or covered subject matter. For example, the subject matter can be embodied as a method, apparatus, component, or system. Therefore, embodiments can take the form of, for example, hardware, software, firmware, or any combination thereof (other than software itself). Therefore, the following detailed description should not be considered limiting.

[0046] Throughout the specification and claims, terms may have subtle meanings implied or implied by the context, beyond their explicitly stated meaning. Similarly, the phrase "in one embodiment" as used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment" as used herein does not necessarily refer to different embodiments. For example, it is expected that the subject matter of the claims encompasses all or part of the exemplary embodiments.

[0047] The terminology used below, even when used in conjunction with the detailed description of certain specific examples of this disclosure, is to be interpreted in the broadest and most reasonable manner. In fact, certain terms may even be emphasized below; however, any term intended to be interpreted in any limiting manner will be clearly and specifically defined in this detailed description section. The foregoing general description and the following detailed description are exemplary and explanatory only and do not limit the features of the claims.

[0048] In this disclosure, the term “based on” means “at least partially based on”. Terms containing ordinal numbers (such as “first,” “second,” etc.) are used to distinguish one element from another among various elements, but are not intended to limit the elements by these terms. The singular forms “a,” “an,” and “the” include plural references unless the context otherwise indicates. The term “exemplary” means “example,” not “ideal.” The term “or” is intended to include and indicate one, any, several, or all of the listed items. The terms “including,” “comprises,” “contains,” “includes,” or variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or product that includes the list of elements does not necessarily contain only those elements, but may also include other elements not expressly listed or inherent to such a process, method, article, or apparatus. Relative terms, such as “substantially” and “generally,” are used to indicate that the stated or understood value may vary by ±5%.

[0049] Furthermore, throughout the specification, when referring to one part as being “connected” or “coupled” to another part, it is not limited to cases where they are “directly connected” or “directly coupled”, but also includes cases where they are “indirectly connected” or “indirectly coupled” by means of arranging one or more elements between them.

[0050] Additionally, as used herein, the term "...unit" refers to a processing unit that has at least one function or operation, and this can be implemented by hardware and software alone or in combination.

[0051] Figure 1 The diagram illustrates, by way of example, a battery diagnostic device, an electric vehicle battery system, and a charging station, including embodiments of the present disclosure.

[0052] refer to Figure 1 The battery system 1 includes a system controller 2, a battery pack 10, an inverter 30, and a motor 40. The charging terminal P+ and discharging terminal P- of the battery pack 10 can be electrically connected to the charging station 300 via a charging cable or the like. The battery system 1 is not particularly limited, as long as it is an electrical system (such as an electric vehicle) that uses a battery as a power source.

[0053] System controller 2 (e.g., ECU: Electronic Control Unit) is configured to send an ignition key signal to battery management system 100 in response to a user switching a start button (not shown) located in battery system 1 to the ignition position. System controller 2 is also configured to send a deactivation key signal to battery management system 100 in response to a user switching the start button to the deactivation position. Charging station 300 can communicate with system controller 2 and supply charging power selected from constant power, constant current, and constant voltage through charging terminal P+ and discharging terminal P- of battery pack 10.

[0054] The battery pack 10 includes a battery 11, a relay 20, and a battery management system 100.

[0055] Battery 11 includes at least one battery cell BC. Figure 1 In the illustration, battery 11 is exemplarily shown as comprising a plurality of battery cells (BC1 to BCN, where N is a natural number of 2 or greater) connected in series. The plurality of battery cells (BC1 to BCN) may be provided to have the same electrochemical specifications. In the following description, when describing characteristics common to the plurality of battery cells (BC1 to BCN), the reference numeral "BC" will be assigned to the battery cell. Charging station 300 can perform the charge and discharge cycles required for diagnosing battery cell BC by cooperating with inverter 30, which has a discharge function.

[0056] A single battery cell BC includes a positive electrode and a negative electrode. A single battery cell BC may include at least one unit cell that serves as an electrochemical element capable of repeated charging and discharging. The single battery cell BC is the target of diagnosis by the battery diagnostic device 302.

[0057] Relay 20 is connected in series to battery 11 via a power path connecting battery 11 and inverter 30. Figure 1 In the diagram, relay 20 is shown connected between the positive terminal of battery 11 and the charging / discharging terminal P+. Relay 20 is controlled to turn on and off in response to a switching signal from battery management system 100. Relay 20 can be a mechanical contactor that turns on and off via the magnetic force of a coil, or a semiconductor switch such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0058] Inverter 30 is provided to convert DC current from battery 11 included in battery pack 10 into AC current in response to commands from battery management system 100 or system controller 2. The AC current power from inverter 30 is used to drive motor 40. For example, a three-phase AC current motor can be used as motor 40. Components in battery system 1 that receive discharge power from battery 11 (such as inverter 30 and motor 40) can be collectively referred to as electrical loads.

[0059] The battery management system 100 includes a sensing unit 110 and a control circuit 130. The battery management system 100 may also include a communication circuit 150.

[0060] The sensing unit 110 includes a voltage sensor 111. The sensing unit 110 may also include a current sensor 112. The sensing unit 110 can generate voltage measurement information and current measurement information, which will be explained later.

[0061] Voltage sensor 111 is connected to the positive and negative terminals of battery cell BC and is configured to detect the voltage across battery cell BC (also referred to as the "full cell voltage") and generate a voltage signal representing the detected value of the voltage. Voltage sensor 111 can be implemented as one or a combination of two or more known voltage sensing elements, such as a voltage measurement IC.

[0062] A current sensor 112 is connected in series to the battery 11 via the current path between the battery 11 and the inverter 30. The current sensor 112 is configured to detect the current flowing through the battery 11 (also referred to as the "charging and discharging current") and generate a current signal representing the detected value of the current. Since multiple battery cells (BC1 to BCN) are connected in series, the current flowing in the battery 11 is the same as the current flowing in the battery cell BC. The current sensor 112 can be implemented as one or a combination of two or more known current sensing elements such as a shunt resistor, a Hall effect element, etc.

[0063] The communication circuit 150 is configured to support wired or wireless communication between the control circuit 130 and the system controller 2. Wired communication may be, for example, CAN (Controller Area Network) communication, and wireless communication may be, for example, ZigBee or Bluetooth communication. The type of communication protocol is not particularly limited, as long as it supports both wired and wireless communication between the control circuit 130 and the system controller 2. The communication circuit 150 may include an output device (e.g., a display, a speaker) that provides information received from the control circuit 130 and / or the system controller 2 in a user- (driver-readable) manner.

[0064] The control circuit 130 is operatively coupled to the relay 20, the voltage sensor 111, and the communication circuit 150. The operative coupling of the two components means that they are directly or indirectly connected to enable the transmission and reception of signals in one or both directions.

[0065] Control circuit 130 can collect voltage signals from voltage sensor 111 and current signals from current sensor 112. In this specification, the term "detection signal" can refer only to the voltage signal or to both the voltage and current signals. That is, control circuit 130 can use an ADC (analog-to-digital converter) provided therein to convert each analog signal collected from sensors 111 and 112 into a digital value and record the digital value. Alternatively, each of voltage sensor 111 and current sensor 112 may include an ADC and send the digital value to control circuit 130.

[0066] The control circuit 130 may be referred to as a "battery controller" and may be implemented in hardware using at least one of an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field-programmable gate array (FPGA), a microprocessor, or an electrical unit for performing other functions.

[0067] Memory 131 may include at least one type of storage medium, such as flash memory, hard disk, solid-state drive (SSD), silicon disk drive (SDD), multimedia card micro, random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), or programmable read-only memory (PROM). Memory 131 may store data and programs required for the computational operations of control circuitry 130. Memory 131 may also store data representing the results of computational operations performed by control circuitry 130.

[0068] When relay 20 is turned on, battery 11 enters charging or discharging mode. If relay 20 is turned off while battery 11 is being used in charging or discharging mode, battery 11 switches to idle mode.

[0069] Control circuit 130 can activate relay 20 in response to a key-on signal. Control circuit 130 can deactivate relay 20 in response to a key-off signal. The key-on signal is a signal requesting a switch from a rest mode to a charging or discharging mode. The key-off signal is a signal requesting a switch from a charging or discharging mode to a rest mode. Alternatively, system controller 2 can be responsible for activating / deactivating relay 20 instead of control circuit 130.

[0070] In this specification, measurement information for a specific parameter (e.g., time series data) indicates the parameter's history of change over time. Furthermore, a curve (or bend) representing the correspondence between any two parameters obtained at the same time point within the same time period can be a mapping of the measurements of the two parameters to each other, such that they can be expressed as a two-dimensional graph, or it can be a polynomial equation obtained by applying predetermined bend fitting logic to the set of measurements of the two mappings. Here, the degree of the highest term of the polynomial equation can be predetermined.

[0071] The battery diagnostic device 302 includes a data acquisition unit 310, a processor 320, and a memory unit 330.

[0072] Charging station 300 may include a stimulus application device 301 and a battery diagnostic device 302. Alternatively, the battery diagnostic device 302 may be configured independently of charging station 300. For example, battery diagnostic device 302 may be provided as an integral part of a remote diagnostic server (not shown), battery pack 10, or battery system 1. The remote diagnostic server may be located remotely from charging station 300. When battery diagnostic device 302 is included in a remote diagnostic server, the data acquisition unit 310 of battery diagnostic device 302 can perform diagnostic processes on individual battery cells BC through remote communication with stimulus application device 301 and / or battery system 1.

[0073] If the battery diagnostic device 302 is included in the battery pack 10 instead of the charging station 300 or remote diagnostic server, then the battery management system 100 can be omitted from the battery pack 10. In other words, the processor 320 can be responsible for all the functions of the control circuitry 130 of the battery management system 100. For example, the data acquisition unit 310 can be included as a sub-component of the processor 320 and can be responsible for all the functions of the communication circuitry 150 of the battery management system 100. Furthermore, the data acquisition unit 310 can collect voltage measurement information and current measurement information from the sensing unit 110.

[0074] The stimulation application device 301 may include a charger that provides charging power for the normal charging of the battery pack 10. The stimulation application device 301 may apply various electrical stimuli to the individual battery cells BC, either alone or in cooperation with the inverter 30, to diagnose the individual battery cells BC.

[0075] The data acquisition unit 310 is configured to support wired or wireless communication between the processor 320 and the system controller 2. The data acquisition unit 310 can send the diagnostic results of the battery cell BC executed by the processor 320 to the battery system 1.

[0076] In terms of hardware, the processor 320 can be implemented using at least one of an ASIC (Application-Specific Integrated Circuit), a DSP (Digital Signal Processor), a DSPD (Digital Signal Processing Device), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), a microprocessor, and an electrical unit for performing other functions.

[0077] Combination Figures 1 to 20 The apparatus 300 and system 1 disclosed in the embodiments, and the various elements contained therein—implemented according to the methods and processes of this disclosure—can be implemented by processor 320 using multiple microprocessors executing software or firmware, or can be implemented using one or more application-specific integrated circuits (ASICs) and related software. In other examples, in combination with Figures 1 to 20 The apparatus 300 or system 1 implementing the embodiments of the methods and processes, and the various elements contained therein, can be implemented using a combination of ASICs, discrete electronic components (e.g., transistors), and microprocessors. In some embodiments, components shown as separate parts may be replaced by a single component. Furthermore, some of the components shown may be additional or may be replaced by other components.

[0078] Memory unit 330 may include at least one type of storage medium, such as flash memory, hard disk, solid-state drive (SSD), silicon disk drive (SDD), multimedia card micro, random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), or programmable read-only memory (PROM). Memory unit 330 may store data representing the results of computational operations performed by processor 320. Memory unit 330 may store datasets and software used for diagnosing the degradation state of battery cell BC.

[0079] In one embodiment, memory cell 330 may store a set of instructions that can be executed to cause processor 320 to perform any one or more of the methods or processes based on the functionality disclosed herein. Memory cell 330 may communicate via one or more wires or buses. Similarly, although not explicitly shown, the components shown in FIG1 may be coupled to each other via one or more wires and buses in any suitable manner known to those skilled in the art to facilitate signal or data communication and operation of apparatus 300 or system 1 according to this disclosure. Memory cell 330 may be main memory, static memory, or dynamic memory. Memory cell 330 may include, but is not limited to, computer-readable storage media, such as various types of volatile and non-volatile storage media, including but not limited to random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, etc. In one embodiment, memory cell 330 may include a cache or random access memory of processor 320. Memory cell 330 may be a processor cache, system memory, or other memory. Memory cell 330 may be operable to store instructions executable by processor 320. The functions, actions, or tasks shown in the figures or described herein can be executed by processor 300 executing instructions stored in memory unit 330. These functions, actions, or tasks are independent of a specific type of instruction set, storage medium, processor, or processing strategy, and can be operated individually or in combination by software, hardware, integrated circuits, firmware, microcode, etc. Similarly, processing strategies can include multiprocessing, multitasking, etc. The computer-readable storage medium described in relation to memory unit 330 according to this disclosure can be non-transitory and can be tangible.

[0080] This document also describes a computer-readable medium having instructions stored thereon configured to cause one or more computers to perform any of the methods described herein. The computer-readable medium may be volatile or non-volatile, removable or non-removable, implemented in any method or technique capable of storing information such as computer-readable instructions, data structures, program modules, or other data. Generally, the functionality of the computing device described herein can be implemented through computational logic embodied in hardware or software instructions, which may be written in a programming language such as C, C++, COBOL, JAVA™, PHP, Perl, Python, Ruby, HTML, CSS, JavaScript, VBScript, ASPX, Microsoft .NET™ languages ​​(such as C#), etc. The computational logic may be compiled into an executable program or may be written in an interpreted programming language. Typically, the functionality described herein can be implemented as a logical module that can be replicated to provide greater processing power, merged with other modules, or divided into submodules. The computational logic can be stored in any type of computer-readable medium (e.g., non-transitory medium, such as memory or storage medium) or computer storage device, and can be stored on and executed by one or more general-purpose or special-purpose processors, thereby creating a special-purpose computing device configured to provide the functionality described herein.

[0081] The applications and functionalities disclosed in the foregoing and subsequent embodiments can be applied in combination with, for example... Figure 1 The description provided for System 1 illustrates the programming of device 300. That is, device 300 or System 1 in the foregoing and subsequent embodiments can utilize, for example, a computer-readable medium having instructions stored thereon configured to cause one or more computers or processors to perform any of the methods described herein.

[0082] In this disclosure, the target cell BC, which is the subject of diagnosis, comprises at least one active material having multiphase properties. Specifically, the target cell BC includes a positive electrode and a negative electrode, and at least one of the positive electrode active material of the positive electrode and the negative electrode active material of the negative electrode has multiphase properties.

[0083] The lack of multiphase characteristics in the positive electrode can mean that its positive electrode active material lacks multiphase characteristics. Similarly, the lack of multiphase characteristics in the negative electrode can mean that its negative electrode active material lacks multiphase characteristics. In other words, the fact that the positive electrode lacks multiphase characteristics means that it contains only a single positive electrode active material and does not possess multiphase characteristics. Multiphase characteristics will be described later.

[0084] In this specification, the new product status has the same concept as the BOL (Start of Life) status. For example, the period from the completion of manufacturing until the cumulative charge and discharge capacity reaches the predetermined set capacity can be called the BOL status; after the cumulative charge and discharge capacity reaches the set capacity, it can be called the MOL (Mid-Life) status.

[0085] Figure 2 and Figure 3 This is a reference graph describing the capacity-voltage relationship of an electrode that does not have multiphase characteristics.

[0086] First of all, Figure 2 In the figure, the curved line indicated by the reference numeral BOL represents the correspondence between the positive electrode voltage and the positive electrode capacity for a predetermined voltage range V1 to V2 when the positive electrode, which does not have multiphase characteristics, is in the BOL state. Reference numeral Q P_BOL Indicates the total positive electrode capacity in the BOL state of a positive electrode that does not exhibit multiphase characteristics. Figure 2 In the figure, the curved line indicated by the reference numeral MOL represents the relationship between the positive electrode voltage and the positive electrode capacity within a predetermined voltage range V1 to V2 when the positive electrode, which does not possess multiphase characteristics, is in the MOL (mid-life) state. The MOL state is a state that degenerates from the BOL state. Therefore, when the positive electrode voltage of the positive electrode curve MOL reaches V2, the positive electrode capacity is less than Q. P_BOL .

[0087] Next, in Figure 3 In the figure, the curved line indicated by the reference numeral BOL is... Figure 2 The positive electrode curve BOL shown is the same. Furthermore, the curved line indicated by the reference numeral MOL' is... Figure 2 The positive electrode curve MOL shown is magnified along the horizontal axis to obtain a capacity range that is consistent with the capacity range of the positive electrode curve BOL.

[0088] It should be noted that the positive electrode curve MOL' is almost identical to the positive electrode curve BOL. Specifically, across the entire capacity range (0 to Q... P_BOL Within this range, the voltage difference between the positive electrode curve MOL' and the positive electrode curve BOL remains close to 0. In other words, in the case of a positive electrode without multiphase characteristics, the overall form of the positive electrode curve in the MOL state is almost unchanged compared to that in the BOL state. Therefore, assuming V P_BOL (Q) represents the polynomial equation corresponding to the positive electrode curve under BOL conditions, V P_MOL (Q) represents the polynomial equation corresponding to the positive electrode curve under the MOL state, and can be considered to satisfy the following two relations.

[0089] [Relation 1] V P_MOL (Q) = V P_BOL (Q × QP_BOL / Q P_MOL ) [Relation 2]V P_BOL (Q) = V P_MOL (Q × Q P_MOL / Q P_BOL ) V P_MOL (Q) represents the positive voltage of the positive electrode curve MOL corresponding to the positive electrode capacity Q. V B_MOL (Q) represents the positive voltage of the positive electrode curve BOL corresponding to the positive electrode capacity Q. P_MOL This represents the positive electrode capacity when the positive electrode voltage of the positive electrode curve MOL is V2, which is the total positive electrode capacity under the MOL state.

[0090] Figure 4 and Figure 5 This is a reference graph describing the capacity-voltage relationship of an electrode with multiphase characteristics.

[0091] first, Figure 4 In the figure, the curved line indicated by the reference numeral BOL is the positive electrode curve, which represents the relationship between the positive electrode voltage and the positive electrode capacity for a predetermined voltage range V1 to V2 when the positive electrode with multiphase characteristics is in the BOL state. Reference numeral Q P_BOL This indicates the total positive electrode capacity of a multiphase positive electrode in the BOL state. Figure 4 In the figure, the curved line indicated by the reference numeral MOL is the positive electrode curve, which represents the correspondence between the positive electrode voltage and the positive electrode capacity for a predetermined voltage range V1 to V2 when the positive electrode with multiphase characteristics is in the MOL (mid-life) state.

[0092] Next, in Figure 5 In the figure, the curved line indicated by the reference numeral BOL is consistent with the curve indicated by the reference numeral BOL. Figure 4 The indicated positive electrode curve BOL is the same. Furthermore, the curved line indicated by the reference numeral MOL' is... Figure 4 The positive electrode curve MOL shown is magnified along the horizontal axis, making the capacity range consistent with... Figure 4 The positive electrode curves BOL shown have the same capacity range.

[0093] and Figure 3 In comparison, Figure 5 In the figure, there is a significant difference between the positive electrode curve MOL' and the positive electrode curve BOL. Specifically, the section where the voltage difference between the positive electrode curve MOL' and the positive electrode curve BOL is large enough to be non-negligible is widely distributed throughout the entire capacity range (0 to Q). P_BOLIn other words, when the cathode contains at least one cathode active material with multiphase properties, the overall form of the cathode curve in the MOL state changes significantly compared to the BOL state. Therefore, the above two relational expressions have no effect on cathodes with multiphase properties.

[0094] At the same time, refer to Figures 2 to 5 The description of the positive electrode is the same as that of the negative electrode.

[0095] The following section explains the multiphase characteristics of the electrode active materials shared by both the positive and negative electrodes.

[0096] Multiphase characteristics refer to the phase change properties of specific types of electrode active materials during charging and discharging. For example, among various types of electrode active materials, so-called manganese-rich (Mn-rich, also known as "high manganese") is a representative positive electrode active material with multiphase characteristics.

[0097] Manganese-rich is a lithium transition metal oxide, which can be used as a ternary cathode material in LiNi. a Co b Mn c Positive electrode active materials in which the specific proportion (c) of manganese in O2 (a, b, c ≥ 0; a + b + c = 1) is increased to a certain value (e.g., 0.5).

[0098] Based on manganese enrichment, the multiphase characteristics of the cathode active material will be described. During charging and discharging, at least a portion of the manganese-rich material undergoes a phase transition between a first phase with a layered structure and a second phase with a spinel-like structure. The dominant reaction in the first phase is likely Ni-redox, i.e., the redox reaction of nickel. The dominant reaction in the second phase is likely M / Oredox, i.e., the redox reaction of manganese with oxygen.

[0099] The cathode profile of a manganese-rich cathode can be determined by the capacity-voltage characteristics depending on the first phase and the capacity-voltage characteristics depending on the second phase. When the manganese-rich cathode degrades from the BOL state to the MOL state, the phase transition characteristics between the first and second phases change significantly compared to the phase transition characteristics in the BOL state, and therefore, the form of the cathode profile in the MOL state (e.g., Figure 5 The form of the MOL' curve in the BOL state and the positive electrode curve in the BOL state (e.g.) Figure 5 The differences between the BOL curves in the data are clearly shown.

[0100] Anode active materials exhibiting multiphase characteristics can be silicon-based active materials (e.g., pure silicon, silicon dioxide, silicon carbide, etc.). In the case of silicon-based active materials, a phase transition occurs between the first phase of the crystalline structure and the second phase of the amorphous structure during charging and discharging in the BOL state. Furthermore, a portion of the crystalline structure of the silicon-based active material may irreversibly amorphize during charging and discharging. Therefore, as the anode, including silicon-based active materials, deteriorates, the ratio of the first phase to the second phase may gradually increase. As described above for cathode active materials, with the deterioration of the anode, the capacity-voltage characteristics of each phase of the anode active material also gradually change, thus significantly altering the form of the anode curve compared to the BOL state.

[0101] Figures 6 to 9 This is a diagram used as a reference for describing the electrode curves used in the diagnosis of individual battery cells.

[0102] An electrode profile may contain multiple electrode profiles. Each electrode profile in the electrode profile may be associated with either the positive or negative electrode of the target cell BC.

[0103] refer to Figure 8 and Figure 9 It is possible to identify m reference positive electrode curves (Rp[1] to Rp[m]) and n reference negative electrode curves (Rn[1] to Rn[n]), and these can be included as electrode curves in the electrode curve diagram. m and n are natural numbers of 2 or greater. Rp[1] can be a reference positive electrode curve representing the capacity-voltage characteristics of the positive electrode in the BOL state. Rn[1] can be a reference negative electrode curve representing the capacity-voltage characteristics of the negative electrode in the BOL state.

[0104] The electrode curve can be pre-stored in the memory unit 330, or it can be received from the outside by the data acquisition unit 310 through the communication channel.

[0105] Figure 6 The degraded positive electrode curve (Rp) is shown. _D_1 To Rp _D_a ). where a is a natural number of 2 or greater, and m or less. If the cathode of the target monomer BC contains an active material with multiphase properties, then the degradation cathode curve (Rp) _D_1 To Rp _D_a It is associated with multiple degradation states of the positive electrode of the target monomer BC.

[0106] The degradation cathode profile (Rp) can be obtained in advance based on the results of previous tests on the reference monomer. _D_1 To Rp _D_a The reference cell is manufactured to have the same level of positive and negative electrode performance as a new battery cell that has been proven to be a good product. A new battery cell refers to a battery cell that is in a new product state.

[0107] Specifically, a degradation cathode profile (Rp) can be prepared in advance based on measurement information representing the capacity-voltage relationship of a cathode half-cell that has been forcibly degraded from the BOL state through various cyclic tests. _D_1 To Rp _D_a The positive electrode half-cell can be a reference monomer manufactured to have the same electrochemical specifications as the target monomer BC.

[0108] Each cycle test may differ from other cycles in at least one aspect of temperature conditions, charge and discharge voltage range conditions, and charge and discharge current rate conditions. For example, the first degradation cathode profile (Rp) _D_1 The process can be based on capacity-voltage measurements of the positive electrode half-cell obtained by disassembling a reference cell, in which a predetermined number of charge and discharge cycles are performed, wherein temperature conditions, charge and discharge voltage range conditions, and charge and discharge current rate conditions are set to 25 [°C], 4.6 to 2.0 [V], and 2 [C], respectively. As another example, the a-th degradation positive electrode curve (Rp) _D_a Based on the capacity-voltage measurement information of the positive electrode half-cell obtained by disassembling another reference cell, a predetermined number of charge and discharge cycles can be performed in that other reference cell, with the temperature conditions, charge and discharge voltage range conditions, and charge and discharge current rate conditions set to 35 [°C], 4.5 to 2.0 [V], and 1 [C], respectively.

[0109] When the cathode of the target monomer BC contains an active material with multiphase properties, the degradation cathode curve (Rp) can be used. _D_1 To Rp _D_a At least two of them (e.g., Rp) _D_1 and Rp _D_a This is included in the electrode curve diagram as a reference positive electrode curve. For example, Rp _D_1 = Rp[2],Rp _D_a = Rp[m].

[0110] refer to Figure 7 When c is a natural number less than a, the two degenerate positive electrode curves (Rp) _D_c and Rp _D_c+1 It exhibits a significant voltage difference across the entire capacity range. Two degraded positive electrode curves (Rp) _D_c and Rp _D_c+1 The comparison value between the two curves may exceed a predetermined threshold, which may be due to the multiphase characteristics of the positive electrode active material. The comparison value between any two curves can be called the "curve error".

[0111] At least one of the reference positive electrode curves (Rp[1] to Rp[m]) can be a simulated positive electrode curve. The simulated positive electrode curve can be synthesized by synthesizing a degraded positive electrode curve (Rp[1]) at a predetermined scale. _D_1 To Rp _D_a It is obtained by simulating at least two degraded positive electrode curves. For example, in Figure 7, when d is a natural number less than or equal to b, the simulated positive electrode curve (Rp) is obtained. _S_d (Rp) is synthesized by using two degraded cathode curves (Rp) in a 0.5:0.5 ratio. _D_c Rp _D_c+1 The new positive electrode curve was obtained from this.

[0112] Of course, by synthesizing two degraded cathode curves (Rp_D_c, Rp_D_c+1) at various ratios (such as 0.1:0.9, 0.2:0.8, etc.), an additional simulated cathode curve located between the degraded cathode curves (Rp_D_c, Rp_D_c+1) can be generated. For example, when two degraded cathode curves (Rp_D_c, Rp_D_c+1) are synthesized at various ratios... p_D_c , R p_D_c+1 When this is done, a predetermined number of simulated cathode curves can be generated, which are located at equal intervals between two degraded cathode curves (Rp). _D_c Rp _D_c+1 )between.

[0113] Due to the degradation of the positive electrode curve (Rp) _D_c Rp _D_c+1 Each simulated cathode curve is associated with different degradation states, therefore each simulated cathode curve is also associated with a different degradation state than the degraded cathode curve (Rp). _D_c Rp _D_c+1 It is related to the degradation state of the positive electrode.

[0114] Each simulated positive electrode curve may already be included in the electrode plot. Alternatively, the processor 320 may generate at least one simulated positive electrode curve based on two degraded positive electrode curves included in the electrode plot, and add each generated simulated positive electrode curve to the electrode plot.

[0115] Figure 8 A set of degraded cathode curves (Rp) are shown. _D_1 To Rp _D_a ) and b simulated positive electrode curves (Rp) _S_1 To R p_S_b ) are used as m reference positive electrode curves (Rp[1] to Rp[m]). In this case, m = a+b.

[0116] When the negative electrode of the target monomer BC contains an active material with multiphase properties, Figure 9The reference negative electrode curves (Rn[1] to Rn[n]) shown can be prepared in advance by applying the method described above for the reference positive electrode curves (Rp[1] to Rp[m]) to the negative electrode of the reference cell. For example, at least two of the reference negative electrode curves (Rn[1] to Rn[n]) can be pre-prepared degraded negative electrode curves based on measurement information representing the capacity-voltage relationship of a negative electrode half-cell forcibly degraded from the BOL state through various cycle tests. This negative electrode half-cell can be the negative electrode of the reference cell. Figure 9 In the middle, Q N_BOL It indicates the total negative electrode capacity of a negative electrode with multiphase characteristics in the BOL state.

[0117] Similar to the reference positive electrode curves (Rp[1] to Rp[m]), the reference negative electrode curves (Rn[1] to Rn[n]) are associated with multiple degradation states of the negative electrode. Furthermore, due to the multiphase nature of the negative electrode active material included in the negative electrode half-cell, the comparison values ​​between at least two of the reference negative electrode curves (Rn[1] to Rn[n]) may exceed a threshold.

[0118] A threshold value becomes the standard for determining the presence of multiphase characteristics. As mentioned above, the capacity-voltage relationship of electrodes containing multiphase active materials varies significantly across multiple degradation states. Therefore, the form of the electrode curve in one degradation state differs significantly from that in another, and the comparison value is a quantification of the degree of difference between these two curves. Therefore, the fact that the comparison value between any two reference positive electrode curves included in the electrode curve diagram is greater than or equal to the threshold value indicates that the positive electrode of the target monomer BC contains active materials with multiphase characteristics. Similarly, the fact that the comparison value between any two reference negative electrode curves included in the electrode curve diagram is greater than or equal to the threshold value indicates that the negative electrode of the target monomer BC contains active materials with multiphase characteristics.

[0119] If the cathode of the target monomer BC contains an active material with multiphase properties, the processor 320 can determine the comparison value between at least two of the m reference cathode curves (Rp[1] to Rp[m]).

[0120] If the negative electrode of the target monomer BC contains an active material with multiphase properties, the processor 320 can determine a comparison value between at least two of the reference negative electrode curves (Rn[1] to Rn[n]).

[0121] Meanwhile, according to this disclosure, the positive and negative electrodes of the target monomer BC do not necessarily both contain active materials with multiphase characteristics as diagnostic targets. When only one of the positive and negative electrodes contains an active material with multiphase characteristics, the target monomer BC can be used as a diagnostic target. Therefore, if only the positive electrode of the target monomer BC has multiphase characteristics and the negative electrode does not have multiphase characteristics, then n = 1, and in this case, it is sufficient to prepare only one reference negative electrode curve (e.g., Rn[1]) representing the capacity-voltage characteristics of the negative electrode in the BOL state. Similarly, if only the negative electrode of the target monomer BC has multiphase characteristics and the positive electrode does not have multiphase characteristics, then m = 1, and in this case, it is sufficient to prepare only one reference positive electrode curve (e.g., Rp[1]) representing the capacity-voltage characteristics of the positive electrode in the BOL state.

[0122] For reference, the higher the degree of degradation of the positive or negative electrode, the greater the voltage change due to the capacity change. With this in mind, each of the reference positive electrode curves (Rp[1] to Rp[m]) can be normalized to have the positive electrode capacity range (0 to Q) of the positive electrode curve under BOL conditions. P_BOL The positive electrode capacity range is the same as that of the negative electrode. Similarly, each of the reference negative electrode curves (Rn[1] to Rn[n]) can be normalized to have the same negative electrode capacity range (0 to Q) as the negative electrode curve in the BOL state. N_BOL The same negative electrode capacity range. Figure 8 Matching of the two endpoints of the reference positive electrode curve (Rp[1] to Rp[m]) and Figure 9 The fact that the two endpoints of the reference negative electrode curve (Rn[1] to Rn[n]) match also confirms this.

[0123] Although Figure 9 Not shown in the figure, but the electrode curves can contain multiple reference full cell curves. Each reference full cell curve is a composite curve of one of the m reference positive electrode curves (Rp[1] to Rp[m]) and one of the n reference negative electrode curves (Rn[1] to Rn[n]), and represents the correspondence between the full cell capacity and the full cell voltage when the reference cell is in a specific degradation state.

[0124] For example, after obtaining capacity-voltage measurement information of a forced-degrade reference cell through specific cycle testing, capacity-voltage measurement information of each of the positive and negative electrodes obtained by disassembling the corresponding reference cell can be obtained. After the specific cycle testing is completed, the electrode plots can include a reference full-cell plot determined from the capacity-voltage measurement information of the reference cell, a reference positive electrode plot determined from the capacity-voltage measurement information of the positive electrode of the reference cell, and a reference negative electrode plot determined from the capacity-voltage measurement information of the negative electrode of the reference cell.

[0125] Figure 10 This is a chart used to illustrate examples of the reference positive and negative electrode curves. Figure 10 In the chart, the horizontal axis (X-axis) represents capacity (Ah), and the vertical axis (Y-axis) represents voltage. For ease of explanation, in... Figure 10 and Figures 12 to 18 In the chart, the numbers marked on the horizontal axis (X-axis) represent the full battery capacity during the charging process.

[0126] refer to Figure 10 The memory unit 330 can store the reference positive curve (Rp[i]) and the reference negative curve (Rn[j]).

[0127] When i is a natural number less than or equal to m, the reference positive curve (Rp[i]) is: Figure 8 One of the m reference positive electrode curves (Rp[1] to Rp[m]) shown. When j is a natural number less than or equal to n, the reference negative electrode curve (Rn[j]) is Figure 9 One of the n reference negative electrode curves (Rn[1] to Rn[n]) shown.

[0128] When m reference positive electrode curves (Rp[1] to Rp[m]) and n reference negative electrode curves (Rn[1] to Rn[n]) are combined, there are a total of m×n pairs, which will be referred to as the 1st to the m×nth electrode curve pairs respectively. For example, if m=20 and n=10, the 1st to the 200th electrode curve pairs can be determined from the electrode curve diagram.

[0129] The reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]) can be two electrode curves contained in the k-th electrode curve pair among the 1st to m×n-th curve pairs. k can be a natural number less than or equal to m×n, and can be the same as i×j. For example, if i=3 and j=2, then k=6. As another example, if i=2 and j=1, then k=2.

[0130] The reference positive electrode curve (Rp[i]) can be a curve representing the relationship between the positive electrode voltage and the positive electrode capacity of a reference cell. The positive electrode voltage of the reference cell refers to the potential difference between the potential of the reference electrode (not shown) and the potential of the positive electrode of the reference cell. The positive electrode curve can also be called the positive half-cell curve.

[0131] The reference negative electrode curve (Rn[j]) can be a curve representing the relationship between the negative electrode capacity and negative electrode voltage of a reference cell. The negative electrode voltage of the reference cell refers to the potential difference between the potential of the reference electrode and the potential of the negative electrode. The negative electrode curve can also be called the negative electrode half-cell curve.

[0132] The potential of the reference electrode (not shown) can be, for example, the redox potential of lithium. The positive electrode voltage can be simply referred to as the positive electrode potential, and the negative electrode voltage can be simply referred to as the negative electrode potential.

[0133] Each of the positive and negative voltages can be either an open-circuit voltage (OCV) or a closed-circuit voltage (CCV).

[0134] In this specification, a first electrical stimulation refers to an electrical stimulation that causes the difference between OCV and CCV to be equal to or less than a reference value in the battery cell, and a second electrical stimulation refers to an electrical stimulation that causes the difference between OCV and CCV to be greater than the reference value in the battery cell. For example, the first electrical stimulation could be charging using a first current rate, and the second electrical stimulation could be charging using a second current rate greater than the first current rate. As another example, the first electrical stimulation could be discharging using a first current rate, and the second electrical stimulation could be discharging using a second current rate greater than the first current rate.

[0135] At least one of the reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]) can be aligned along the horizontal axis such that the common capacity range of the two curves (Rp[i], Rn[j]) is ( Figure 10 The synthesis results of a portion of the 5Ah to 50Ah cells matched the reference full cell curve (R[k]). Figure 10 An example is shown in which the reference negative curve (Rn[j]) is aligned to the right based on the reference positive curve (Rp[i]), which is the starting point of one of the two endpoints (corresponding to the point with capacity 0).

[0136] from Figure 10 It can be seen that the two ends of the reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]) are offset from each other. In other words, the capacity ranges of the reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]) do not match and only partially overlap. Therefore, the reference full-cell curve (R[k]) indicates the full-cell voltage of the reference cell within a portion of the common capacity range of the reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]). In other words, the reference full-cell curve (R[k]) is an example of a full-cell voltage curve obtained by directly subtracting a portion of the reference negative electrode curve (Rn[j]) from a portion of the reference positive electrode curve (Rp[i]).

[0137] The reference full-cell curve (R[k]) can represent the relationship between the full-cell voltage and the full-cell capacity when a new cell that has been verified as a good product is forced to degrade under arbitrary cycling conditions.

[0138] A reference full-cell curve (R[k]) can represent the correspondence between the voltage and capacity of a reference cell within at least the voltage range of interest (e.g., 3.0 to 4.0 V). The lower and upper limits of the voltage range of interest can be a first set voltage ( Figure 10 3.0V in the middle) and the second set voltage ( Figure 10 (4.0V in the middle).

[0139] If the total cell voltage, including the reference cell, is equal to a first set voltage, then the State of Charge (SOC) can be set to 0%. When the total cell voltage, including the reference cell, is equal to a second set voltage, the SOC can be set to 100%. Figure 10 The reference cell can be charged from a fully discharged state (SOC 0%) to a fully charged state (SOC 100%) by charging with a capacity of 45Ah.

[0140] In this specification, when the full-cell voltage of a corresponding battery cell matches the first set voltage, the positive electrode participation start point on the positive electrode curve of any battery cell represents the positive electrode voltage and positive electrode capacity (or positive electrode SOC). Furthermore, when the full-cell voltage of a corresponding battery cell matches the first set voltage, the negative electrode participation start point on the negative electrode curve of the corresponding battery cell indicates the negative electrode voltage and negative electrode capacity (or negative electrode SOC). Therefore, the voltage difference between the positive electrode participation start point and the negative electrode participation start point can be equal to the first set voltage.

[0141] Furthermore, when the full-cell voltage of the corresponding battery cell matches the second set voltage, the positive electrode participation endpoint on the positive electrode curve of any battery cell indicates the positive electrode voltage and positive electrode capacity (or positive electrode SOC). Similarly, when the full-cell voltage of the corresponding battery cell matches the second set voltage, the negative electrode participation endpoint on the negative electrode curve of the corresponding battery cell indicates the negative electrode voltage and negative electrode capacity (or negative electrode SOC). Therefore, the voltage difference between the positive electrode participation endpoint and the negative electrode participation endpoint can be equal to the second set voltage.

[0142] In this specification, at least one of the positive electrode participation start point and the positive electrode participation end point can be simply referred to as the positive electrode point, and at least one of the negative electrode participation start point or the negative electrode participation end point can be simply referred to as the negative electrode point. Furthermore, the positive electrode capacity (capacity value) at a specific point on the positive electrode curve of a given battery cell can refer to the capacity difference between either of the two endpoints of the positive electrode curve and the specific point. The positive electrode SOC at a specific point on the positive electrode curve of any battery cell can refer to the ratio of the capacity difference between either of the two endpoints of the positive electrode curve (e.g., the low capacity point) and the specific point to the capacity difference between the two endpoints of the positive electrode curve. The capacity difference between the two endpoints of the positive electrode curve can be referred to as the total positive electrode capacity.

[0143] Similarly, the negative electrode capacity (capacity value) at a specific point on the negative electrode curve of any battery cell can refer to the capacity difference between either of the two endpoints of the negative electrode curve (or positive electrode curve) and that specific point. The negative electrode SOC at a specific point on the negative electrode curve of any battery cell can refer to the ratio of the capacity difference between either of the two endpoints of the negative electrode curve (or positive electrode curve) (e.g., the low capacity point) and that specific point to the capacity difference between the two endpoints of the negative electrode curve. The capacity difference between the two endpoints of the negative electrode curve can be referred to as the total negative electrode capacity.

[0144] In memory cell 330, information indicating the voltage at each of the reference positive electrode participation start point (pi0), reference positive electrode participation end point (pf0), reference negative electrode participation start point (ni0), and reference negative electrode participation end point (nf0) can be pre-recorded. The reference positive electrode participation start point (pi0) and reference positive electrode participation end point (pf0) are the positive electrode participation start point and positive electrode participation end point on the reference positive electrode curve (Rp[i]), respectively. The reference negative electrode participation start point (ni0) and reference negative electrode participation end point (nf0) are the negative electrode participation start point and negative electrode participation end point on the reference negative electrode curve (Rn[j]), respectively.

[0145] The voltage difference between the reference positive electrode participation start point (pi0) and the reference negative electrode participation start point (ni0) can be equal to a first set voltage (e.g., 3.0V). The voltage difference between the reference positive electrode participation end point (pf0) and the reference negative electrode participation end point (nf0) can be equal to a second set voltage (e.g., 4.0V).

[0146] Figure 11 and Figure 12 This is a diagram used to illustrate the process of obtaining a full-cell measurement curve.

[0147] Figure 11 The graph depicted illustrates an example of the change in the full-cell voltage of a target cell over time due to intermittent application of a second electrical stimulus. The target cell is a battery cell undergoing diagnosis by a battery diagnostic device. The target cell can be a new battery cell requiring verification of its product quality, or a battery cell that has been verified as a product quality but is no longer considered new due to degradation.

[0148] Reference Figure 11 The processor 320 can control the stimulation application device 301 to intermittently apply a second electrical stimulus to the target monomer BC.

[0149] The process of controlling the stimulation application device 301 to diagnose the target cell BC can be performed during the state change period before the electrical state (e.g., full cell voltage) of the target cell BC is changed from an initial state (e.g., a first set voltage) to a target state (e.g., a second set voltage).

[0150] refer to Figure 11 The graph shows that the full-cell voltage of the target cell BC exhibits an upward trend while repeating a sawtooth pattern. Each sawtooth voltage rise segment is caused by the application of a second electrical stimulus, and the voltage drop segment is caused by the interruption of the second electrical stimulus. That is, each voltage drop segment represents the change in the full-cell voltage of the target cell BC during each rest period within the state-change period. During each rest period, the target cell BC is placed in an unloaded state and is neither charged nor discharged.

[0151] During the state change period, the processor 320 can repeatedly record the current measurement value of the target cell BC to generate current measurement information. The capacity of the target cell BC is based on the ampere count of the current measurement value, and therefore the current measurement information can refer to the capacity measurement information.

[0152] Whenever a predetermined rest condition is met during a state change period, the processor 320 can control the stimulation application device 301 to initiate a rest period for the second electrical stimulation. In other words, the application of the second electrical stimulation can be temporarily stopped when the rest condition is met. For example, at least one of the following can be preset as a rest condition: (i) the current integral value changes the threshold integral value, (ii) the state of charge (SOC) changes the threshold SOC, and (iii) the duration of application of the second electrical stimulation reaches a threshold time. For example, if the total current integral value during the state change period is 40 Ah and the threshold integral value is 2 Ah, a total of 20 rest periods can be permitted during the state change period.

[0153] Processor 320 can determine at least one of a threshold integral value, a threshold SOC, and a threshold time based on the full charge capacity, SOH, or previous diagnostic results of the target cell BC. At least one of the threshold integral value, threshold SOC, and threshold time can have a predetermined positive (or negative) correspondence with the full charge capacity, SOH, or previous diagnostic results, and relational data (a data table for controlling rest periods) defining this correspondence can be pre-stored in memory unit 330. Due to the predetermined positive (or negative) correspondence, as the full charge capacity, SOH, or previous diagnostic results decrease, at least one of the threshold integral value, threshold SOC, and threshold time also decreases. As a result, as the target cell BC deteriorates over time, rest periods are given at shorter intervals within the state-change period, thus preventing a reduction in the number of data points included in the voltage measurement information—which indicates the history of changes in the full cell voltage over time during the rest periods of the state-change period.

[0154] Processor 320 may obtain at least one of a threshold integral value, threshold SOC, and threshold time mapped to full charge capacity, SOH, or previous diagnostic results from a data sheet for use in rest period control. Processor 320 may use at least one of the threshold integral value, threshold SOC, and threshold time obtained from the data sheet for rest period control to control the intermittent application process of the second electrical stimulation during the state change period.

[0155] When a reference time has elapsed since the start of the rest period of the second electrical stimulation, the processor 320 can control the stimulation application device 301 to resume the application of the second electrical stimulation. The reference time can be predetermined such that the polarization caused by the second electrical stimulation can be sufficiently neutralized. For example, the reference time, which is the length of the rest period, can be the time required for the polarization at the start of the rest period to become 10% or less.

[0156] During each rest period of the second electrical stimulation, the full-cell voltage of the target cell BC is measured at least once. As an example, the processor 320 can record the measured full-cell voltage at the end of each rest period of the second electrical stimulation as the OCV of the target cell BC. As another example, the full-cell voltage can be measured at least three times during each rest period of the second electrical stimulation, and the processor 320 can estimate the OCV of the target cell BC for each rest period based on the three full-cell voltage measurements for each rest period.

[0157] Therefore, voltage measurement information can be generated by recording the OCV and time difference multiple times during the state change period. Figure 11 Each OCV point (D) marked in the middle OCV () is an example of an OCV measurement value representing voltage measurement information.

[0158] The inventors of this disclosure have realized through multiple experiments that the voltage measurement information generated by using the second electrical stimulation in the manner described above has a high degree of consistency with the voltage measurement information generated when the first electrical stimulation is actually applied to the target monomer BC.

[0159] From this point onward, the advantages of diagnostic methods based on the intermittent application of a second electrical stimulus rather than the continuous application of a first electrical stimulus will be described.

[0160] The following conditions are assumed to be relevant to the diagnosis of the target monomer BC.

[0161] (i) First electrical stimulation = charging at 0.05C (ii) Second electrical stimulation = charging at 3.0C (iii) The length of the rest period after the second electrical stimulation = 12 minutes (iv) Total capacity change during the state change period = 80% of the full charge capacity (FCC) of the target cell BC. (v) Threshold integral value = 3% of the full charge capacity of the target cell BC Then, by continuously applying the first electrical stimulation, the time taken for the target monomer BC to change from the initial state to the target state is 1 / 0.05*80%=16 hours.

[0162] In contrast, the time taken for the target cell BC to increase its charging capacity by the threshold integral value through the second electrical stimulation is 0.03 / 3 * 80% = 0.008 hours. Furthermore, since a rest period is permitted whenever the charging capacity increases by 3%, a total of 26 rest periods are permitted during the state-changing period. Therefore, the time taken for the target cell BC to change from its initial state to its target state through intermittent application of the second electrical stimulation is (0.008 hours + 0.2 hours) * 26 = 5.4 hours.

[0163] In other words, compared with the method of continuously applying the first electrical stimulation, the method of intermittently applying the second electrical stimulation is beneficial to shortening the time to obtain the full cell curve.

[0164] exist Figure 12 In the graph, the horizontal axis (X-axis) represents capacity (Ah), and the vertical axis (Y-axis) represents voltage.

[0165] refer to Figure 12 The processor 320 can generate a measured full-cell curve M representing the correspondence between the capacity and voltage (also known as the full-cell voltage) of the target cell BC based on the capacity measurement information and voltage measurement information of the target cell BC. The measured full-cell curve M can also be referred to as the QV curve or Q-OCV curve. The measured full-cell curve M can be used as the "first curve" in the claims.

[0166] Here, the full-cell voltage is the voltage across the target cell BC, and it differs from the positive and negative electrode voltages mentioned above. In other words, the full-cell voltage of the target cell BC can be considered as the difference between the positive and negative electrode voltages of the target cell BC.

[0167] To generate the full-cell measurement curve M, current and voltage measurement information mapped to the state change period can be used.

[0168] In detail, each data point of the current measurement information and voltage measurement information is indexed in chronological order. Therefore, the processor 320 can generate capacity measurement information by sequentially integrating the data points of the current measurement information. Furthermore, the processor 320 can generate a full-cell measurement curve M by applying a curved line fitting algorithm to a set of multiple Q-OCV pairs included in the capacity-voltage measurement information, which is a dataset to which the capacity measurement information and voltage measurement information are mapped. The reference full-cell curve (R[k]), reference positive electrode curve (Rp[i]), reference negative electrode curve (Rn[j]), and the full-cell measurement curve M can be polynomial equations, where the order of the highest term is predetermined.

[0169] Similar to the reference full cell curve (R[k]), the measured full cell curve M can represent the correspondence between the capacity of the target cell BC in at least the voltage range of interest (e.g., 3.0 to 4.0 V) and the full cell voltage (e.g., OCV).

[0170] like Figure 12 As shown, there is a certain degree of difference between the measured full-cell curve M and the reference full-cell curve (R[k]). If the reference full-cell curve (R[k]) is adjusted appropriately, the difference between it and the measured full-cell curve M can be reduced.

[0171] At the same time, Figure 10 and Figure 12 In the graph, Ah is used as the unit on the horizontal axis, but this unit can be expressed in other forms. For example, the unit on the horizontal axis could be a percentage (%), which represents SOC (State of Charge) instead of Ah.

[0172] The processor 320 can generate multiple comparison curves based on multiple electrode curves included in the electrode curve diagram. Specifically, the processor 320 can generate multiple comparison curves by performing an adjustment operation (also known as "curve adjustment logic") on each of the multiple electrode curves included in the electrode curve diagram according to multiple adjustment levels.

[0173] The curve adjustment logic may include at least one of scaling and shifting operations. When the curve adjustment logic is executed, the processor 320 can generate multiple comparison curves by repeating adjustment and synthesis processes for each of the two electrode curves (Rp[i], Rn[j]) of the k-th electrode curve pair according to multiple adjustment levels. The comparison curves may also be referred to as "comparison full-cell curves". Here, each comparison curve generated from the k-th electrode curve pair may be a full-cell curve in which the two adjusted electrode curves are synthesized (combined) as the adjustment result of each of the reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]). In other words, when the reference full-cell curve (R[k]) is the result of subtracting a portion of the reference negative electrode curve (Rn[j]) from a portion of the reference positive electrode curve (Rp[i]), the comparison curve can be considered as the result of subtracting a portion of the adjusted negative electrode curve from a portion of the adjusted positive electrode curve. Each comparison curve may be referred to as an "adjusted reference full-cell curve".

[0174] The processor 320 can be configured to generate k-th curve adjustment data by comparing each of a plurality of comparison curves generated from the k-th electrode curve pair with the measured full-cell curve M.

[0175] Processor 320 can select any one of the multiple comparison curves generated from the k-th electrode curve pair (Rp[i], Rn[j]) that has the smallest comparison value with the measured full-cell curve M. Processor 320 can determine the comparison value of each of the multiple comparison curves for measuring the full-cell curve M, and determine that the k-th comparison value is equal to the minimum of the multiple comparison values.

[0176] In this regard, various methods known at the time of filing of this application can be used to determine the comparison value between two curves. For example, the integral value of the absolute value of the area between the two curves, MSE (mean square error) or RMSE (root mean square error), can be used as the comparison value.

[0177] Processor 320 can generate k-th curve adjustment data related to the k-th electrode curve pair (Rp[i], Rn[j]). The k-th curve adjustment data may include information representing at least one of the k-th comparison value, the k-th representative curve, the k-th adjusted positive electrode curve, and the k-th adjusted negative electrode curve. The k-th representative curve is a comparison curve mapped to the minimum comparison value among the multiple comparison curves generated from the k-th electrode curve pair (Rp[i], Rn[j]).

[0178] The k-th adjusted positive electrode curve and the k-th adjusted negative electrode curve are two adjusted electrode curves used to synthesize the k-th representative curve. Information representing the k-th adjusted positive electrode curve includes the k-th adjusted positive electrode curve itself and / or at least one diagnostic factor that can be confirmed from the k-th adjusted positive electrode curve. Information representing the k-th adjusted negative electrode curve includes the k-th adjusted negative electrode curve itself and / or at least one diagnostic factor that can be confirmed from the k-th adjusted negative electrode curve.

[0179] When each natural number from 1 to m×n is set to k and the above process is performed a total of m×n times, first to m×n curve adjustment data are generated. Processor 320 can select any one of the first to m×n curve adjustment data as the information that most closely represents the current charge and discharge performance (current degradation state) of the target cell BC. If the kth comparison value among the first to m×n comparison values ​​is the smallest, then the kth representative curve among the first to m×n representative curves can be used as the "second curve" in the claim.

[0180] According to this configuration, even if the target cell BC is not disassembled or manufactured in the form of a 3-electrode battery, information about the positive and negative electrode curves of the target cell BC can be estimated accurately and independently.

[0181] If the target cell BC is a new battery cell, it is easier to analyze and use the adjusted positive and negative electrode curves to diagnose whether defects have occurred in the target cell BC, and if so, to diagnose what type of defect it is.

[0182] If the battery cell is used after verifying that the target cell BC is a good product, the degree of degradation of the target cell BC, which indicates the degradation status of each diagnostic item, can be determined by adjusting the positive and negative electrode curves.

[0183] The following is for reference Figures 13 to 18 This describes the curve adjustment logic for one of the parameters (diagnostic factors) involved in estimating the current charge and discharge performance of the target cell BC.

[0184] Figures 13 to 15 This is a diagram illustrating an example of the process of generating a comparison curve from the k-th electrode curve pair (Rp[i], Rn[j]) for comparison with the measured full-cell curve M.

[0185] Reference Figures 13 to 15 The curve adjustment logic described is used to set four points (positive participation start point, positive participation end point, negative participation start point, negative participation end point) to the first routine corresponding to the voltage range of interest (see [link]). Figure 13 The second routine used to perform shift operations (see...) Figure 14 ) and a third routine for performing scaling operations (see Figure 15 The curve adjustment logic according to embodiments of this disclosure is performed in the following order. That is, the curve adjustment logic according to embodiments of this disclosure includes a first routine to a third routine.

[0186] First, refer to Figure 13 The reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]) are compared with Figure 10 The same as those shown.

[0187] The processor 320 determines the positive electrode participation start point (pi), positive electrode participation end point (pf), negative electrode participation start point (ni), and negative electrode participation end point (nf) on the reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]).

[0188] One of the positive participation start point (pi) or the negative participation start point (ni) depends on the other. As an example, processor 320 can divide the positive voltage range from the start point to the end point (or a second set voltage) of the two endpoints of a reference positive curve (Rp[i]) into multiple small voltage segments, and then set the boundary point of two adjacent small voltage segments among the multiple small voltage segments as the positive participation start point (pi). Each small voltage segment can have a predetermined size (e.g., 0.01V). Next, processor 320 can set a point on the reference negative curve (Rn[j]) that is smaller than the positive participation start point (pi) by a first set voltage (e.g., 3V) as the negative participation start point (ni). As another example, processor 320 can divide the negative voltage range from the start point to the end point of the reference negative curve (Rn[j]) into multiple small voltage segments of a predetermined size, and then set the boundary point of two adjacent small voltage portions among the multiple small voltage segments as the negative participation start point (ni). Next, the processor 320 can search from the reference positive curve (Rp[i]) for a point that is larger than the negative participation start point (ni) by a first set voltage, and set the searched point as the positive participation start point (pi).

[0189] The positive terminal participation endpoint (pf) or the negative terminal participation endpoint (nf) depends on the other. As an example, processor 320 can divide the voltage range from the second set voltage to the endpoint of the reference positive curve (Rp[i]) into multiple small voltage segments of a predetermined size, and then set the boundary point between two adjacent small voltage segments as the positive terminal participation endpoint (pf). Next, processor 320 can set a point on the reference negative curve (Rn[j]) that is lower than the positive terminal participation endpoint (pf) by the second set voltage (e.g., 4V) as the negative terminal participation endpoint (nf). As another example, processor 320 can divide the negative voltage range from the start point to the end point of the reference negative curve (Rn[j]) into multiple small voltage segments of a predetermined size, and then set the boundary point between two adjacent small voltage segments as the negative terminal participation endpoint (nf). Next, the processor 320 can search from the reference positive curve (Rp[i]) for a point that is larger than the negative participation endpoint (nf) by a second set voltage, and set the searched point as the positive participation endpoint (pf).

[0190] If the positive electrode participation start point (pi), positive electrode participation end point (pf), negative electrode participation start point (ni), and negative electrode participation end point (nf) are completely determined, then the processor 320 will shift at least one of the reference positive electrode curve (Rp[i]) and the reference negative electrode curve (Rn[j]) to the left or right along the horizontal axis.

[0191] refer to Figure 14 The processor 320 can shift the reference positive curve (Rp[i]) to the left (towards low capacity) or shift the reference negative curve (Rn[j]) to the right (towards high capacity), or both, so that the capacity values ​​of the positive participation start point (pi) and the negative participation start point (ni) on the horizontal axis are matched.

[0192] Alternatively, the processor 320 may shift the reference positive curve (Rp[i]) to the left or shift the reference negative curve (Rn[j]) to the right or both, so that the capacity values ​​of the positive participation endpoint (pf) and the negative participation endpoint (nf) on the horizontal axis are matched.

[0193] and Figure 13 compared to, Figure 14This illustrates the case where only the reference positive curve (Rp[i]) is shifted to the left to generate the adjusted positive curve (Rp[i]'), and thus, the capacity value at the positive participation start point (pi') matches the capacity value at the negative participation start point (ni). The adjusted positive curve (Rp[i]') is the result of applying an adjustment process to the reference positive curve (Rp[i]), which is shifting the voltage difference between the positive participation start point (pi) and the negative participation start point (ni) to the left. Therefore, the two points (pi, pi') differ only in capacity value and have the same voltage. The two points (pf, pf') also differ only in capacity value and have the same voltage.

[0194] If at least one of the reference positive curve (Rp[i]) and the reference negative curve (Rn[j]) is shifted, the adjusted result curve (Rp[i]', Rn) is ensured, then the processor 320 scales the capacity range of at least one of the adjusted result curves (Rp[i]', Rn).

[0195] according to Figure 14 In the example shown, processor 320 performs an additional adjustment process to shrink or expand at least one of the adjusted positive curve (Rp[i]') and the reference negative curve (Rn[j]) along the horizontal axis.

[0196] refer to Figure 15 The processor 320 can generate an adjusted positive electrode curve (Rp[i]") by shrinking or expanding the adjusted positive electrode curve (Rp[i]'), such that the capacity range between two points (pi', pf') of the adjusted positive electrode curve (Rp[i]') matches the capacity range of the measured full-cell curve M. In this case, either point (pi') can be fixed. Therefore, the capacity difference between the two points (pi', pf") of the adjusted positive electrode curve (Rp[i]") can match the capacity range of the measured full-cell curve M.

[0197] Furthermore, the processor 320 can generate an adjusted negative electrode curve (Rn[j]') by shrinking or expanding the reference negative electrode curve (Rn[j]) such that the capacity range between the two points (ni, nf) of the reference negative electrode curve (Rn[j]) matches the capacity range of the measured full-cell curve M. In this case, either point (ni) can be fixed. Therefore, the capacity difference between the two points (ni, nf') of the adjusted negative electrode curve (Rn[j]') can match the capacity range of the measured full-cell curve M.

[0198] exist Figure 15 In the middle, the adjusted positive curve (Rp[i]") is the contraction curve. Figure 14The results shown are the adjusted positive electrode curve (Rp[i]') and the adjusted negative electrode curve (Rn[j]') are extended. Figure 14 The results of the reference negative electrode curve (Rn[j]) are shown.

[0199] The positive electrode participation endpoint (pf") on the adjusted positive electrode curve (Rp[i]") corresponds to the positive electrode participation endpoint (pf) on the adjusted positive electrode curve (Rp[i]'). The negative electrode participation endpoint (nf') on the adjusted negative electrode curve (Rn[j]') corresponds to the negative electrode participation endpoint (nf) on the reference negative electrode curve (Rn[j]).

[0200] The capacity difference between the positive electrode participation start point (pi') and the positive electrode participation end point (pf") of the adjusted positive electrode curve (Rp[i]") corresponds to the size of the capacity range of the full-cell curve M. Similarly, the capacity difference between the negative electrode participation start point (ni) and the negative electrode participation end point (nf') of the adjusted negative electrode curve (Rn[j]') corresponds to the size of the capacity range of the full-cell curve M.

[0201] Furthermore, the capacity range of the two points (pi', pf") of the adjusted positive electrode curve (Rp[i]") matches the capacity range of the two points (ni, nf') of the adjusted negative electrode curve (Rn[j]').

[0202] Processor 320 can generate a comparison curve S using an adjusted positive curve (Rp[i]") and an adjusted negative curve (Rn[j]'). Processor 320 can generate the comparison curve S based on the voltage difference data between the adjusted positive curve (Rp[i]") and the adjusted negative curve (Rn[j]'). The voltage difference data can represent the capacity-voltage difference relationship within the common capacity range of the two curves (Rp[i]"), Rn[j]'. In other words, processor 320 can generate the comparison curve S by subtracting the curve between two points (ni, nf') of the adjusted positive curve (Rp[i]") from the curve between two points (ni, nf') of the adjusted negative curve (Rn[j]').

[0203] The processor 320 can calculate the comparison value between the comparison curve S and the full-cell measurement curve M.

[0204] The processor 320 can map at least two of the adjusted positive curve (Rp[i]"), adjusted negative curve (Rn[j]'), positive participation start point (pi'), positive participation end point (pf"), negative participation start point (ni), negative participation end point (nf'), positive scaling factor, negative scaling factor, comparison curve S and comparison value to each other, and record them in the memory unit 330.

[0205] The positive electrode scaling factor can represent the ratio of the capacity difference between the two ends of the adjusted positive electrode curve (Rp[i]") to the capacity difference between the two ends of the reference positive electrode curve (Rp[i]). The positive electrode scaling factor can also represent the ratio of the capacity difference between two points (pi', pf") to the capacity difference between two points (pi0, pf0). Alternatively, the positive electrode scaling factor can represent the ratio of the positive electrode capacity difference between two points (pi', pf") to the positive electrode capacity difference between two points (pi0, pf0). Alternatively, the positive electrode scaling factor can represent the ratio of the positive electrode SOC difference between two points (pi', pf") to the positive electrode SOC difference between two points (pi0, pf0).

[0206] The negative electrode scaling factor can represent the ratio of the capacity difference between the two ends of the adjusted negative electrode curve (Rn[j]') to the capacity difference between the two ends of the reference negative electrode curve (Rn[j]). Alternatively, the negative electrode scaling factor can represent the ratio of the capacity difference between two points (ni, nf') to the capacity difference between two points (ni0, nf0). Alternatively, the negative electrode scaling factor can represent the ratio of the negative electrode capacity difference between two points (ni, nf') to the negative electrode capacity difference between two points (ni0, nf0). Alternatively, the negative electrode scaling factor can represent the ratio of the negative electrode SOC difference between two points (ni, nf') to the negative electrode SOC difference between two points (ni0, nf0).

[0207] Meanwhile, as mentioned above, when the positive voltage range of the reference positive curve (Rp[i]) is divided into multiple small voltage segments, the boundary point of two adjacent small voltage segments among the multiple small voltage segments can be set as the positive participation starting point (pi).

[0208] For example, if the positive voltage range of the reference positive electrode curve (Rp[i]) is divided into 100 smaller voltage ranges, then 100 boundary points can be set as the positive electrode participation start point (pi). Furthermore, if the voltage range in the reference positive electrode curve (Rp[i]) that is greater than or equal to the second set voltage is divided into 40 smaller voltage ranges, then 40 boundary points can be set as the positive electrode participation end point (pf). In this case, at least 4,000 different comparison curves can be generated from the k-th electrode curve pair (Rp[i], Rn[j]).

[0209] Of course, those skilled in the art will readily understand that as the size of the small voltage segment decreases, the maximum number of comparison curves that can be generated increases, and conversely, as the size of the small voltage segment increases, the maximum number of comparison curves that can be generated decreases.

[0210] As described above, processor 320 can generate k-th curve adjustment data, which is associated with the k-th representative curve that has the smallest k-th comparison value among multiple comparison curves generated based on the k-th electrode curve pair (Rp[i], Rn[j]). The k-th curve adjustment data can be recorded in memory unit 330.

[0211] Figures 16 to 18 This is a diagram referenced as another example illustrating the process of generating a comparison curve from the k-th electrode curve pair (Rp[i], Rn[j]) for comparison with the measured full-cell curve M. For reference, Figures 16 to 18 The embodiments shown are independent of Figures 13 to 15 The illustrated embodiment. Therefore, it is commonly used to describe Figures 13 to 15 The illustrated embodiments and Figures 16 to 18 The terminology or reference numerals in the embodiments shown should be understood to be limited to each embodiment.

[0212] Reference Figures 16 to 18 Another example of the curve adjustment logic can be found in the fourth routine that performs the scaling operation (see [link]). Figure 16 The fifth routine sets four points (positive electrode participation start point, positive electrode participation end point, negative electrode participation start point, and negative electrode participation end point) (see...). Figure 17 ) and the sixth routine that performs the shift operation (see Figure 18 The curve adjustment logic according to another embodiment of this disclosure includes the fourth to sixth routines.

[0213] refer to Figure 16 The processor 320 generates an adjusted reference positive curve (Rp[i]') and an adjusted reference negative curve (Rn[j]') by applying the positive and negative scaling factors selected from the scaling value range to the reference positive curve (Rp[i]) and the reference negative curve (Rn[j]), respectively.

[0214] The scaling range can be predetermined or can vary depending on the ratio of the capacity range of the measured full-cell curve M to the capacity range of the reference full-cell curve (R[k]). As an example, suppose the positive and negative scaling factors can be selected from values ​​at intervals of 0.1% within the scaling range (e.g., 90% to 99%) (i.e., 90%, 90.1%, 90.2%, ... 98.9%, 99%), and 91 values ​​can be selected as the positive and negative scaling factors, respectively. In this case, based on 91 × 91 = 8,281 adjustment levels (combinations of the positive and negative scaling factors), up to 8,281 adjusted curve pairs can be generated from the k-th electrode curve pair (Rp[i], Rn[j]). An adjusted curve pair refers to a combination of an adjusted positive curve and an adjusted negative curve.

[0215] refer to Figure 16 The adjusted positive curve (Rp[i]') and the adjusted negative curve (Rn[j]') show the results of applying the positive scaling factor and the negative scaling factor, which are one of multiple adjustment levels, to the reference positive curve Rp[i] and the reference negative curve Rn[j], respectively.

[0216] When the positive and negative scaling factors are less than 100%, the adjusted positive curve (Rp[i]') is obtained by shrinking the reference positive curve (Rp[i]) along the horizontal axis, and the adjusted negative curve (Rn[j]') is also obtained by shrinking the reference negative curve (Rn[j]) along the horizontal axis. For ease of understanding, the reference positive curve (Rp[i]) and the reference negative curve (Rn[j]) are shown with their starting points fixed and the remaining portions shrunk to the left along the horizontal axis.

[0217] refer to Figure 17 The processor 320 determines the positive participation start point (pi'), positive participation end point (pf'), negative participation start point (ni'), and negative participation end point (nf') on the adjusted positive curve (Rp[i]') and the adjusted reference negative curve (Rn[j]').

[0218] One of the positive electrode participation start point (pi') or the negative electrode participation start point (ni') can depend on the other. Furthermore, one of the positive electrode participation end point (pf') or the negative electrode participation end point (nf') can depend on the other. Moreover, one of the positive electrode participation start point (pi') or the positive electrode participation end point (pf') can be set based on the other.

[0219] In other words, if any one of the positive electrode participation start point (pi'), positive electrode participation end point (pf'), negative electrode participation start point (ni'), and negative electrode participation end point (nf') is set, the remaining three points can be automatically set by the first set voltage, the second set voltage, and / or the capacity range of the measured full-cell curve M (e.g., Figure 12 (45Ah - 5Ah = 40Ah).

[0220] As an example, processor 320 can divide the positive voltage range from the start point to the end point (or the second set voltage) of the adjusted positive curve (Rp[i]') into multiple small voltage segments, and then set the boundary point of two adjacent small voltage segments among the multiple small voltage segments as the positive participation start point (pi'). Next, processor 320 can set the point on the adjusted negative curve (Rn[j]') that is smaller than the positive participation start point (pi') by a first set voltage (e.g., 3V) as the negative participation start point (ni').

[0221] As another example, processor 320 can divide the negative voltage range from the start point to the end point of the adjusted negative voltage curve (Rn[j]') into multiple small voltage segments of a predetermined size, and then set the boundary point of two adjacent small voltage segments among the multiple small voltage segments as the negative participation start point (ni'). Next, processor 320 can search from the reference positive curve (Rp[i]) for a point that is larger than the negative participation start point (ni') by a first predetermined voltage, and select the searched point as the positive participation start point (pi').

[0222] As another example, processor 320 can divide the voltage range from the second set voltage to the endpoint of the adjusted positive curve (Rp[i]') into multiple small voltage segments of a predetermined size, and then set the boundary point of two adjacent small voltage segments among the multiple small voltage segments as the positive participation endpoint (pf'). Next, processor 320 can search for a point in the adjusted negative curve (Rn[j]') that is smaller than the second set voltage (e.g., 4V) than the positive participation endpoint (pf'), and set the searched point as the negative participation endpoint (nf').

[0223] As another example, processor 320 can divide the negative voltage range from the start point to the end point of the adjusted negative voltage curve (Rn[j]') into multiple small voltage segments of a predetermined size, and then set the boundary point of two adjacent small voltage segments among the multiple small voltage segments as the negative participation endpoint (nf'). Next, processor 320 can search from the adjusted positive voltage curve (Rp[i]') for a point that is larger than the negative participation endpoint (nf') by a second predetermined voltage, and set the searched point as the positive participation endpoint (pf').

[0224] If any one of the positive electrode participation start point (pi'), positive electrode participation end point (pf'), negative electrode participation start point (ni'), and negative electrode participation end point (nf') is determined, the processor 320 can additionally determine the remaining three points based on the determined point.

[0225] For example, if the positive electrode participation start point (pi') is determined first, the processor 320 can set the point on the adjusted positive electrode curve (Rp[i]') with a capacity value that is larger than the capacity range of the full-cell curve M by which the positive electrode participation start point (pi') is measured, as the positive electrode participation end point (pf'). Furthermore, the processor 320 can search for a point on the adjusted negative electrode curve (Rn[j]') with a voltage lower than the positive electrode participation start point (pi'), and set the searched point as the negative electrode participation start point (ni'). Additionally, the processor 320 can set the point on the adjusted negative electrode curve (Rn[j]') with a capacity value that is larger than the capacity range of the full-cell curve M by which the negative electrode participation start point (ni') is measured, as the negative electrode participation end point (nf').

[0226] As another example, when first determining the positive electrode participation endpoint (pf'), the processor 320 can set a point on the adjusted positive electrode curve (Rp[i]') with a capacity value smaller than the capacity value of the full-cell curve M that measures the capacity range of the positive electrode participation endpoint (pf') as the positive electrode participation start point (pi'). Furthermore, the processor 320 can search for a point on the adjusted negative electrode curve (Rn[j]') with a voltage lower than the positive electrode participation endpoint (pf') and set the searched point as the negative electrode participation endpoint (nf'). Additionally, the processor 320 can set a point on the adjusted negative electrode curve (Rn[j]') with a capacity value smaller than the capacity value of the full-cell curve M that measures the capacity range of the negative electrode participation endpoint (nf') as the negative electrode participation start point (ni').

[0227] As another example, when determining the negative electrode participation start point (ni'), the processor 320 can set the point on the adjusted negative electrode curve (Rn[j]') whose capacity value is greater than the capacity value of the negative electrode participation start point (ni') by the size of the capacity range of the measured full-cell curve M as the negative electrode participation end point (nf'). Furthermore, the processor 320 can search for a point on the adjusted positive electrode curve (Rp[i]') that is higher than the negative electrode participation start point (ni') by a first set voltage, and set the searched point as the positive electrode participation start point (pi'). Additionally, the processor 320 can set the point on the adjusted positive electrode curve (Rp[i]') whose capacity value is greater than the capacity value of the measured full-cell curve M by the size of the capacity range of the positive electrode participation start point (pi') as the positive electrode participation end point (pf').

[0228] As another example, when determining the negative electrode participation endpoint (nf'), the processor 320 can set a point on the adjusted negative electrode curve (Rn[j]') whose capacity value is smaller than the capacity value of the negative electrode participation endpoint (nf') within the capacity range of the measured full-cell curve M as the negative electrode participation start point (ni'). Furthermore, the processor 320 can search for a point on the adjusted positive electrode curve (Rp[i]') that is higher than the negative electrode participation endpoint (nf') by a second set voltage, and set the searched point as the positive electrode participation endpoint (pf'). Additionally, the processor 320 can set a point on the adjusted positive electrode curve (Rp[i]') with a capacity value smaller than the capacity value of the measured full-cell curve M within the capacity range of the measured full-cell curve M as the positive electrode participation start point (pi').

[0229] If the positive electrode participation start point (pi'), positive electrode participation end point (pf'), negative electrode participation start point (ni'), and negative electrode participation end point (nf') are determined entirely based on the pairing of positive and negative electrode scaling factors, then the processor 320 may shift at least one of the adjusted positive electrode curve (Rp[i]') and the adjusted negative electrode curve (Rn[j]') to the left or right along the horizontal axis, such that the capacity values ​​of the positive electrode participation start point (pi') and the negative electrode participation start point (ni') match or the capacity values ​​of the positive electrode participation end point (pf') and the negative electrode participation end point (nf') match.

[0230] Figure 18 The adjusted negative electrode curve (Rn[j]") shown is obtained by only using Figure 17 The adjusted negative electrode curve (Rn[j]') shown is obtained by shifting it to the right. Therefore, the capacity values ​​of the positive electrode participation start point (pi') and the negative electrode participation start point (ni") are matched on the horizontal axis. Correspondingly, the capacity difference between the positive electrode participation start point (pi') and the positive electrode participation end point (pf') is equal to the capacity difference between the negative electrode participation start point (ni') and the negative electrode participation end point (nf'). Therefore, if the capacity values ​​of the positive electrode participation start point (pi') and the negative electrode participation start point (ni'') are matched, then the capacity values ​​of the positive electrode participation end point (pf') and the negative electrode participation end point (nf') are also matched on the horizontal axis.

[0231] refer to Figure 18The processor 320 can generate a comparison curve U using the adjusted positive curve (Rp[i]') and the adjusted negative curve (Rn[j]"). The processor 320 can generate the comparison curve U based on the voltage difference data between the adjusted positive curve (Rp[i]') and the adjusted negative curve (Rn[j]"). The voltage difference data can represent the capacitance-voltage difference relationship within the common capacitance range of the two curves (Rp[i]', Rn[j]"). In other words, the processor 320 can generate the comparison curve U by subtracting the curve (pi', pf') between two points (ni", nf") of the adjusted negative curve (Rn[j]"). The processor 320 can generate the comparison curve U by subtracting the curve between two points (ni", nf") of the adjusted positive curve (Rp[i]') from the curve between two points (ni" and nf") of the adjusted negative curve (Rn[j]").

[0232] The processor 320 can calculate the comparison value between the comparison curve U and the full-cell measurement curve M.

[0233] The processor 320 can map at least two of the following: positive curve (Rp[i]'), adjusted negative curve (Rn[j]"), positive participation start point (pi'), positive participation end point (pf'), negative participation start point (ni"), negative participation end point (nf"), positive scaling factor, negative scaling factor, comparison curve U, and comparison value, and record them in the memory unit 330.

[0234] As described above, processor 320 can generate a comparison curve corresponding to each pair of positive and negative scaling factors selected from the scaling value range. Since the pairing of positive and negative scaling factors is complex, it is obvious that the comparison curve will also be generated as a complex number.

[0235] Processor 320 can generate k-th curve adjustment data, which is associated with the k-th representative curve that has the smallest k-th comparison value among multiple comparison curves generated based on the k-th electrode curve pair (Rp[i], Rn[j]). The k-th curve adjustment data can be recorded in memory unit 330.

[0236] The processor 320 can obtain at least one diagnostic factor from any of the curve adjustment data (associated with the second curve) that is mapped to the minimum comparison value among the first to m×n curve adjustment data.

[0237] In detail, the curve adjustment data associated with the second curve includes at least one of the positive electrode state data and the negative electrode state data.

[0238] The positive electrode state data is based on an adjusted positive electrode curve, which is used to generate the second curve. For example, when Figure 15 When the comparison curve S shown is determined as the second curve, at least one of the positive pole (pi'), positive pole (pf"), positive scaling factor, and positive load of the adjusted positive curve (Rp[i]") can be included as a diagnostic factor in the positive state data. As another example, when Figure 18 When the comparison curve U shown is determined as the second curve, at least one of the positive pole (pi'), positive pole (pf'), positive scaling factor, and positive load of the adjusted positive curve (Rp[i]') can be included as a diagnostic factor in the positive state data.

[0239] The negative electrode state data is based on an adjusted negative electrode curve, which is used to generate the second curve. For example, when Figure 15 When the comparison curve S shown is determined as the second curve, at least one of the following: the negative pole (ni), the negative pole (nf'), the negative pole scaling factor, and the negative pole load of the adjusted negative pole curve (Rn[i]') can be included as a diagnostic factor in the negative pole state data. As another example, when Figure 18 When the comparison curve U shown is determined as the second curve, at least one of the negative pole (ni"), negative pole (nf"), negative pole ratio factor and negative pole load of the adjusted negative pole curve (Rn[j]") can be included as a diagnostic factor in the negative pole state data.

[0240] For reference, when the target unit BC is in the new product state, as the above curve adjustment logic is executed, the value of at least one of the positive electrode participation start point, positive electrode participation end point, negative electrode participation start point, negative electrode participation end point, positive electrode scaling factor and negative electrode scaling factor in the BOL state may have been recorded in the memory unit 330.

[0241] Figure 19 This is a flowchart illustrating a battery diagnostic method according to another embodiment of the present disclosure. Figure 19 The battery diagnostic method can be performed by the battery diagnostic device 302.

[0242] In step S1910, the processor 320 obtains, through the data acquisition unit 310, a first curve representing the capacity-voltage relationship of the target monomer BC containing an active material with multiphase properties (see...). Figure 12 (M in the attached figure).

[0243] For example, a first curve M can be generated in battery system 1 and then sent to battery diagnostic device 302, and data acquisition unit 310 can receive the first curve M via a communication channel. Alternatively, data acquisition unit 310 can generate the first curve M by processing capacity-voltage measurement information of target cell BC collected from battery system 1.

[0244] In step S1920, the processor 320 generates multiple comparison curves based on the multiple electrode curves included in the electrode curve diagram. That is, as described above... Figures 1 to 18 The processor 320 generates multiple comparison curves from each of the first to m×n electrode curve pairs by combining m reference positive electrode curves (Rp[1] to Rp[m]) and n reference negative electrode curves (Rn[1] to Rn[n]). Therefore, the number of comparison curves generated in step S1920 can be at least twice m×n.

[0245] In step S1930, the processor 320 compares each of the multiple comparison curves generated in step S1920 with the first curve, and selects one of the multiple comparison curves as the second curve.

[0246] Specifically, the processor 320 generates adjustment data for the first to m×n curves from the first to the m×n electrode curves (see...). Figures 13 to 15 and / or Figures 16 to 18 Next, the processor 320 can select any one of the comparison curves with the smallest comparison value from the first to the m×n comparison values ​​indicated by the first to m×n curve adjustment data as the second curve.

[0247] In step S1940, the processor 320 determines at least one diagnostic factor indicating the degradation state of the target monomer BC based on the second curve. In step S1940, the positive electrode loading is determined as a diagnostic factor, and another diagnostic factor may also be determined.

[0248] Specifically, processor 320 can determine at least one diagnostic factor indicative of the current degradation state of the target monomer BC from curve adjustment data associated with the second curve. For example, if Figure 15 If the comparison curve S shown has the minimum comparison value of the first curve M, then in step S1940, it can be... Figure 15 The pi', pf", ni, nf', etc. shown are identified as additional diagnostic factors. As another example, if Figure 18 The comparison curve U shown has Figure 18 The minimum comparison value of the first curve M shown in the figure can be used to identify pi', pf', ni", nf", etc. as additional diagnostic factors.

[0249] In step S1950, processor 320 estimates at least one degradation parameter based on at least one diagnostic factor determined in step S1940. For reference, at least one degradation parameter may be included as a diagnostic factor in the curve adjustment data.

[0250] In step S1960, processor 320 limits at least one of the permissible voltage range and SOC range for the target cell BC based on at least one diagnostic factor determined in step S1940. In conjunction with or alternatively to this, the permissible current for the target cell BC can be limited (e.g., adjusted downwards).

[0251] In memory unit 330, predetermined positive or negative correlation data indicating the change level (e.g., increase, decrease, rate of increase, rate of decrease) of at least one diagnostic factor from the BOL state can be pre-stored with respect to a limit level. That is, as the change level of at least one diagnostic factor increases, at least one of the allowable voltage range and SOC range for the target cell BC can gradually decrease. Decreasing the range means increasing at least one of the lower limit of the range and decreasing the upper limit of the range. For example, when the positive electrode capacity (or positive electrode SOC) at the endpoint of positive electrode participation decreases from its value in the BOL state, the upper limit of the allowable voltage range and / or SOC range for the target cell BC can be limited to a specific level.

[0252] In step S1970, processor 320 may use data acquisition unit 310 to send the diagnostic results of the target cell BC to battery system 1. The diagnostic results include at least one of the following: at least one diagnostic factor obtained in step S1940, at least one degradation parameter estimated in step S1950, and the voltage range and SOC range limited in step S1960. Visual and / or auditory information indicating the diagnostic results may be output to the user through battery system 1.

[0253] At least one of steps S1950, S1960, and S1970 can be derived from... Figure 19 The method is omitted.

[0254] In a computer-readable medium according to this disclosure, information for reference may be stored. Figures 1 to 19 Instructions describing a diagnostic process. When executed by processor 320, the instructions in the computer-readable medium cause processor 320 to perform at least one part of the diagnostic process.

[0255] Figure 20 It is a description that can be found Figure 19 The diagram shown refers to the open-circuit voltage (OCV) estimation process performed in the method illustrated. (Reference) Figure 11 as well as Figure 20The processor 320 can estimate the OCV for each voltage drop segment based on voltage measurement information for the state change period.

[0256] Figure 20 The figure reference 2000 is Figure 11 The image shows a magnified example of one of the voltage drop segments. Voltage measurement information corresponding to a specific voltage drop segment within a specific rest period includes measurements of the full cell voltage taken three or more times during that specific rest period. One of the measurements of the full cell voltage taken three or more times can be D... OCV . t R This indicates the point in time that has elapsed since the start of the rest period, up to the reference time. R The portion is shown with a solid line, and in t R The following section is shown with dashed lines.

[0257] Processor 320 can determine the OCV estimate of the target cell BC for each rest period by applying OCV estimation logic to the measured full-cell voltage for each rest period, which differs from D. OCV Therefore, if a total of X rest periods are granted during the state change period and the full cell voltage is measured three times for each rest period, those skilled in the art will readily understand that the voltage measurement information obtained in step S1910 includes 3X full cell voltage measurements, and X OCV estimates can be determined based on the 3X full cell voltage measurements.

[0258] During the rest period, the full-cell voltage of the target cell BC gradually converges toward the OCV corresponding to the SOC of the target cell BC. The behavior of the full-cell voltage of the target cell BC during a specific rest period can be equivalent to the voltage response of the primary RC circuit, as shown in Equation 1 below.

[0259] <Formula 1> In Formula 1, t is the time elapsed since the start of a specific rest period, and V is the time elapsed from the beginning of that rest period. full (t) is the full cell voltage at point t, V. OCV It is the actual OCV, V S It is the full cell voltage at the start of a specific rest period, and τ is a time constant determined by the internal resistance and capacity of the target cell BC.

[0260] In Formula 1, V full (t) is measurable, therefore V OCV V S And τ are unknown. Since there are three unknowns, V can be determined based on measurements taken at three different timing points during a specific rest period.full The OCV is estimated using (t). Formula 2 below can be used to estimate the OCV for each rest period.

[0261] <Formula 2> In Formula 2, t1, t2, and t3 are the timing parameters for the sequential measurement of the full-cell voltage. The time difference between t1 and t2 can be the same as the time difference between t2 and t3. Meanwhile, in Figure 20 In the middle, t R t3 is shown differently from t3, but t R =t3 is also possible. In this case, V full (t3)=D OCV .

[0262] Processor 320 can be coupled with V calculated by Formula 2 OCV Determine D in the same way OCV_C .

[0263] Processor 320 can repeatedly measure three full-cell voltage values ​​(V) for each rest period. full (t1), V full (t2), V full (t3) is replaced with a single OCV value (D) for all rest periods. OCV_C The process of determining X OCV estimates is as follows.

[0264] For reference, D OCV It is the measured value of the full cell voltage at the end of the resting period (before the polarization is completely resolved), while D OCV_C The full cell voltage (i.e., V) is the voltage when polarization is completely resolved. OCV The estimated value of D. Therefore, it can be considered that D... OCV_C D OCV The actual OCV is closer to that of the target monomer BC.

[0265] In step S1910, the processor 320 can extract voltage measurement information from the capacity-voltage measurement information, and then by using the D value of each rest period indicated by the voltage measurement information. OCV Change (correct) to D OCV_C To generate calibrated voltage measurement information. Processor 320 can apply curve fitting logic to X OCV estimates (i.e., D values) included in the calibrated voltage measurement information. OCV_C The full-cell measurement curve M is generated using data points based on capacity measurement information.

[0266] From now on, the description can be found Figure 19The degradation parameters estimated in step S1950. Table 1 below summarizes the degradation parameters and the formulas that can be used to determine each degradation parameter.

[0267] Each variable listed in Table 1 is a diagnostic factor that can be obtained in step S2140. The definitions of the degradation parameters and variables in Table 1 can be as follows.

[0268] <Degradation Parameters> P SOH : The positive electrode SOH (health status) of the target monomer BC N SOH : The negative electrode SOH of the target monomer BC L SOH Available lithium SOH for target monomer BC F SOH : Full cell SOH of target single cell BC P LOSS : Cathode loss rate of target single cell BC N LOSS Negative electrode loss rate of target monomer BC L LOSS Available lithium loss rate of target monomer BC F LOSS : Total cell loss rate of target single cell BC P loading_MOL : Positive electrode loading of target cell BC N loading_MOL The negative electrode loading of the target single cell BC As any battery cell deteriorates, at least one of the corresponding cell's total positive electrode capacity, total negative electrode capacity, available lithium, and total full cell capacity will gradually decrease from its value in the BOL state. Total full cell capacity can be represented as the capacity difference between the two endpoints of the full cell curve. For example, total full cell capacity can refer to the fully charged capacity (FCC). Available lithium can represent the total amount of lithium that can contribute to the charging and discharging of the battery cell. P SOH It can represent the retention rate of the total positive electrode capacity. N SOH It can represent the retention rate of the total negative electrode capacity. L SOH It can represent the retention rate of available lithium. F SOH It can represent the retention rate of the total full battery capacity.

[0269] P SOH With P LOSS sum, N SOH With N LOSS The sum of L SOH With L LOSS The sum of, and F SOH With FLOSS The sum of each can be equal to 1. F LOSS It can be equal to P LOSS With L LOSS sum.

[0270] The positive electrode loading of a specific battery cell represents the amount of positive electrode active material per unit area of ​​the positive electrode of that battery cell. The negative electrode loading of a specific battery cell represents the amount of negative electrode active material per unit area of ​​the negative electrode of that battery cell. The unit of loading can be mAh / cm². 2 or mg / cm 2 In Table 1, P loading_ref This indicates the reference positive electrode load, and N loading_ref This indicates the reference negative electrode load. The reference positive electrode load is intended to represent the positive electrode load when the battery cell is manufactured normally. The reference negative electrode load is intended to represent the negative electrode load when the battery cell is manufactured normally.

[0271] <variable> pi BOL When the target single cell BC is in the BOL state, the positive electrode capacity (positive electrode SOC) at the starting point of the positive electrode participation. pi MOL The current positive electrode participation starting point of the target monomer BC (e.g., Figure 15 The positive electrode capacity (positive electrode SOC) of pi' is shown in the figure. pf BOL When the target single cell BC is in the BOL state, the positive electrode participates in the final positive electrode capacity (positive electrode SOC). pf MOL The current positive electrode of the target cell BC participates in the endpoint (e.g., Figure 15 The positive electrode capacity (positive electrode SOC) shown in the figure is pf". ni BOL When the target monomer BC is in the BOL state, the negative electrode participates in the starting point of the negative electrode capacity (negative electrode SOC). ni MOL The current negative electrode participation starting point of the target monomer BC (e.g., Figure 15 The negative electrode capacity (negative electrode SOC) of ni is shown in the figure. nf BOL When the target monomer BC is in the BOL state, the negative electrode participates in the final negative electrode capacity (negative electrode SOC). nf MOL The current negative electrode of the target monomer BC participates in the endpoint (e.g., Figure 15 The negative electrode capacity (negative electrode SOC) of nf' is shown in the figure. ps BOL : Positive scaling factor when the target single cell BC is in the BOL state ps MOL : Current positive scaling factor of target cell BC ns BOL Negative scaling factor when the target single unit BC is in the BOL state. ns MOL : Current negative pole scaling factor of target single cell BC The process of determining diagnostic factors using the above curve adjustment logic can be repeated periodically or non-periodically throughout the entire lifetime of the target monomer BC. Therefore, when the target monomer BC is in the MOL state, the diagnostic factor (pi) is determined when it is in the BOL state. BOL , pf BOL , ni BOL nf BOL ps BOL ns BOL ) and degradation parameter (P SOH N SOH L SOH F SOH P LOSS N LOSS L LOSS F LOSS P loading N loading At least one of the following may have already been recorded in memory unit 330, etc. For example, diagnostic factors (pi) BOL , pf BOL , ni BOL nf BOL ps BOL ns BOL The value can be the value at the time the target unit BC leaves the factory. Furthermore, throughout the entire lifespan of the target unit BC, the processor 320 can output diagnostic factors (pi). MOL , pf MOL , ni MOL nf MOL ps MOL ns MOL At least one and / or degradation parameter (P) in ) SOH N SOH L SOH F SOH P LOSS N LOSS L LOSS F LOSS P loading_MOL N loading_MOL The change history of at least one of them is stored in memory cell 330.

[0272] With PS MOL proportional P loading_MOLIt can be included in the curve adjustment data associated with the second curve as a diagnostic factor rather than as a degradation parameter. Similarly, with ns... MOL proportional N loading_MOL It can be included in the curve adjustment data associated with the second curve as a diagnostic factor rather than as a degradation parameter.

[0273] The degradation characteristics of each diagnostic factor based on a battery cell containing a positive electrode active material with multiphase properties (such as manganese-rich material) will be further described.

[0274] With P LOSS Increase, oxygen redox reactions (oxygen-redox) increase and pf MOL Possibly from pf BOL Decrease. pf MOL The reduction in [the concentration of the positive electrode] can promote an increase in the positive electrode voltage at the endpoint of the positive electrode participation, thereby further increasing the oxygen-redox reaction. Therefore, the processor 320 can be based on [the technology / mechanism]. Figure 19 The method identifies pf MOL The reduction of P in the target monomer BC is used to diagnose the P of the target monomer BC. LOSS It is increasing. Furthermore, processor 320 can respond to pf MOL The reduction in the upper limit of the allowable voltage range for the target monomer BC is reduced to suppress the increase in the positive electrode voltage at the endpoint of participation at the positive electrode, which can slow down the oxygen-redox reaction.

[0275] In the early portion of the BOL state, the manganese redox reaction (Mn-redox) increases, thus the available lithium quantity may increase compared to the factory setting, and each of the positive electrode capacity (or positive SOC) at the positive electrode participation start point and the negative electrode capacity (or negative electrode SOC) at the negative electrode participation start point may decrease compared to the factory setting. The increase in available lithium quantity can lead to an increase in the total full cell capacity. After the early portion of the BOL state, the available lithium quantity stops increasing. Thereafter, each of the positive electrode capacity (or positive electrode SOC) at the positive electrode participation start point and the negative electrode capacity (or negative electrode SOC) at the negative electrode participation start point gradually increases, which is an indicator of degradation indicating a decreasing available lithium quantity. Therefore, the processor 320 can diagnose the L of the target cell BC. LOSS and N LOSS At least one of them is based on the Figure 19 The method for identifying pi MOL The increase and / or ni MOL The number increases with the increase in pi. Furthermore, the processor 320 can respond to pi MOL The increase and / or ni MOL The increase reduces the upper limit of the voltage range allowed for the target cell BC.

[0276] The redox reactions of oxygen (oxygen-redox) and manganese (Mn-redox) tend to increase together, and as a result, pi MOL With pf MOL The gap between them narrows, and as P... LOSS Add, ps MOL and / or P loading_MOL It may be reduced. The processor 320 can be based on... Figure 19 The method of identifying ps MOL and / or P loading_MOL The reduction of P in the target monomer BC is used to diagnose the P of the target monomer BC. LOSS It's increasing. Furthermore, the processor 320 can respond to ps... MOL and / or P loading_MOL The reduction in voltage range and / or SOC range for the target cell BC is reduced.

[0277] When the negative electrode is exposed to a low potential region by charging and discharging the target monomer BC, the crystal structure of the negative electrode changes, and byproducts of side reactions (e.g., SEI, solid electrolyte interface) accumulate on the surface of the negative electrode, resulting in a decrease in the reactivity of the negative electrode. In other words, N LOSS Decrease, and nf MOL Accordingly, it decreases. MOL The increase and nf MOL The reduction means ns MOL and / or N loading_MOL The reduction. Processor 320 can be based on... Figure 19 The method for identifying nf MOL ns MOL and / or N loading_MOL The reduction of N in the target monomer BC is used to diagnose the N LOSS It is increasing. Furthermore, the processor 320 can respond to NF... MOL ns MOL and / or N loading_MOL The reduction in voltage range and / or SOC range for the target cell BC is reduced.

[0278] The embodiments of this disclosure described above can be implemented not only by the apparatus and method, but also by a program that performs functions corresponding to the configuration of the embodiments of this disclosure or a recording medium having a program recorded thereon. Based on the disclosure of the previously described embodiments, those skilled in the art can readily implement such implementations.

[0279] While this disclosure has been described above with respect to a limited number of embodiments and accompanying drawings, this disclosure is not limited thereto, and it will be apparent to those skilled in the art that various modifications and changes can be made to it within the technical aspects of this disclosure and within the equivalent scope of the appended claims.

[0280] Furthermore, since those skilled in the art can make many substitutions, modifications and changes to this disclosure without departing from its technical aspects, this disclosure is not limited to the above embodiments and drawings, and some or all of the embodiments can be selectively combined to allow for various modifications.

Claims

1. A battery diagnostic device, comprising: A data acquisition unit is configured to acquire a first curve representing the capacity-voltage relationship of a single battery cell, the single battery cell comprising an active material having multiphase characteristics; as well as A processor configured to generate multiple comparison curves based on multiple electrode curves included in an electrode profile. The processor is configured as follows: A comparison curve is selected as the second curve from the plurality of comparison curves by comparing each of the plurality of comparison curves with the first curve. as well as The positive electrode load is determined based on the second curve as a diagnostic factor representing the degradation state of the battery cell.

2. The battery diagnostic device according to claim 1, wherein, The electrode curves include multiple reference positive electrode curves associated with multiple degradation states of the positive electrode of the battery cell, and The active material, which has multiphase properties, is included in the positive electrode of the battery cell.

3. The battery diagnostic device according to claim 2, wherein, Each of at least two of the plurality of reference positive electrode curves is a degraded positive electrode curve representing the capacity-voltage relationship of the positive electrode half-cell.

4. The battery diagnostic device according to claim 3, wherein, The processor is configured to determine the comparison value based on the at least two reference positive electrode curves, and Wherein, the comparison value is greater than the threshold.

5. The battery diagnostic device according to claim 1, wherein, The electrode profile includes multiple reference negative electrode profiles associated with multiple degradation states of the negative electrode of the battery cell, and The active material, which has multiphase properties, is included in the negative electrode of the battery cell.

6. The battery diagnostic device according to claim 5, wherein, Each of at least two of the plurality of reference negative electrode curves is a degraded negative electrode curve representing the capacity-voltage relationship of the negative electrode half-cell.

7. The battery diagnostic device according to claim 6, wherein, The processor is configured to determine the comparison value based on the at least two reference negative electrode curves, and Wherein, the comparison value is greater than the threshold.

8. The battery diagnostic device according to claim 1, wherein, The processor is configured to generate the plurality of comparison curves by performing an adjustment operation on each of the plurality of electrode curves according to a plurality of adjustment levels.

9. The battery diagnostic device according to claim 8, wherein, The adjustment operation includes at least one of a scaling operation or a shift operation based on the capacity relationship value of the individual battery cells.

10. The battery diagnostic device according to claim 8, wherein, The processor is configured to determine a plurality of comparison values ​​by comparing each of the plurality of comparison curves with the first curve, and The second curve is associated with the smallest comparison value among the plurality of comparison values.

11. The battery diagnostic device according to claim 10, wherein, The processor is configured to generate curve adjustment data associated with the second curve. The curve adjustment data includes at least one of positive electrode state data associated with the adjusted positive electrode curve and negative electrode state data associated with the adjusted negative electrode curve. The adjusted positive electrode curve and the adjusted negative electrode curve are generated by adjusting two of the plurality of electrode curves, and The adjusted positive electrode curve and the adjusted negative electrode curve are used to generate the second curve.

12. The battery diagnostic device according to claim 11, wherein, The processor is configured to generate the second curve based on voltage difference data representing the voltage difference between the adjusted positive curve and the adjusted negative curve.

13. The battery diagnostic device according to claim 11, wherein, The positive electrode state data includes the positive electrode load, and also includes at least one of the positive electrode participation start point, positive electrode participation end point, and positive electrode scaling factor.

14. The battery diagnostic device according to claim 11, wherein, The negative electrode status data includes at least one of the following: negative electrode participation start point, negative electrode participation end point, negative electrode scaling factor, and negative electrode load.

15. The battery diagnostic device according to claim 1, wherein, The processor is configured to limit at least one of the voltage range and state of charge range of the battery cell based on the diagnostic factors.

16. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 15.

17. A battery system comprising a battery diagnostic device according to any one of claims 1 to 15.

18. A remote diagnostic server comprising a battery diagnostic apparatus according to any one of claims 1 to 15.

19. A battery diagnostic method, comprising: A first curve representing the capacity-voltage relationship of a single battery cell is obtained, wherein the battery cell comprises an active material having multiphase characteristics; Multiple comparison curves are generated based on multiple electrode curves included in the electrode curve plot; A comparison curve is selected as the second curve from the plurality of comparison curves by comparing each of the plurality of comparison curves with the first curve. as well as The positive electrode load is determined based on the second curve as at least one diagnostic factor representing the degradation state of the battery cell.

20. A computer-readable medium storing instructions for diagnosing a battery cell, the instructions, when executed by one or more processors, causing the one or more processors to perform operations, the operations including: A first curve representing the capacity-voltage relationship of the battery cell is obtained, wherein the battery cell comprises an active material having multiphase characteristics; Multiple comparison curves are generated based on multiple electrode curves included in the electrode curve plot; A comparison curve is selected as the second curve from the plurality of comparison curves by comparing each of the plurality of comparison curves with the first curve. as well as The positive electrode load is determined based on the second curve as a diagnostic factor representing the degradation state of the battery cell.

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