Battery management apparatus and battery management method

Abstract

This battery management apparatus comprises: an interface configured to acquire battery data of a battery to be managed which is measured at a plurality of degradation time points; and a controller configured to generate, on the basis of the battery data, a first SOC-OCV profile at a beginning-of-life (BOL) time point and voltage-capacity profiles of the battery to be managed at the plurality of degradation time points, identify, on the basis of the voltage-capacity profiles, a boundary voltage for distinguishing an upper voltage degradation characteristic having an upper capacity degradation rate and a lower voltage degradation characteristic having a lower capacity degradation rate, and estimate a second SOC-OCV profile at a middle-of-life (MOL) time point on the basis of the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

Description

Battery management device and battery management method

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2025-0001447, filed January 6, 2025, and Korean Patent Application No. 10-2024-0048834, filed April 11, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The embodiments disclosed in this document relate to a battery management device and a battery management method.

[0005] Recently, active research and development has been conducted on secondary batteries. The term "secondary battery" refers to a rechargeable battery, encompassing both conventional Ni / Cd and Ni / MH batteries, as well as recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries can boast higher energy densities than conventional Ni / Cd and Ni / MH batteries. They can be manufactured in small and lightweight designs, making them highly versatile power sources for mobile devices. Recently, their use has expanded to include power sources for electric vehicles, attracting attention as a next-generation energy storage medium.

[0006] The embodiments disclosed in this document provide a battery management device and a battery management method capable of estimating a SOC-OCV (State of Charge - Open Circuit Voltage) profile that changes due to degradation in an NCM (Nickel Cobalt Manganese) cell having an atypical composition ratio.

[0007] According to one embodiment of the present invention, a battery management device includes an interface configured to acquire battery data of a battery to be managed measured at a plurality of degradation points in time; and a controller configured to generate a first SOC-OCV profile at a beginning of life (BOL) point in time and voltage-capacity profiles of the battery to be managed at the plurality of degradation points in time based on the battery data, identify a boundary voltage that distinguishes an upper voltage degradation characteristic having an upper capacity degradation rate and a lower voltage degradation characteristic having a lower capacity degradation rate based on the voltage-capacity profiles, and estimate a second SOC-OCV profile at a middle of life (MOL) point in time based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

[0008] The battery data includes low-rate discharge data measured through low-rate discharge of about 0.1C or less of the managed battery at the plurality of degradation points, and the controller is configured to generate the voltage-capacity profiles based on the low-rate discharge data at the plurality of degradation points.

[0009] The controller is configured to generate dQ / dV profiles representing the differential value of capacity with respect to voltage (dQ / dV) at the plurality of degradation points based on the low-rate discharge data, and to generate the voltage-capacity profiles based on the dQ / dV profiles at the plurality of degradation points.

[0010] The controller is configured to identify the boundary voltage based on a pattern of the dQ / dV profiles.

[0011] The controller is configured to generate a corrected SOC-OCV profile at the MOL point in time by applying the upper capacity degradation rate to the first SOC-OCV profile at an upper portion of the boundary voltage and by applying the lower capacity degradation rate to the first SOC-OCV profile at a lower portion of the boundary voltage.

[0012] The controller is configured to generate an interpolated SOC-OCV profile by performing interpolation for SOC units on the corrected SOC-OCV profile, and to estimate the second SOC-OCV profile by applying an OCV offset to the interpolated SOC-OCV profile.

[0013] The above-mentioned battery to be managed includes an NCM battery containing nickel, cobalt and manganese, and the above-mentioned upper voltage degradation characteristics and the above-mentioned lower voltage degradation characteristics are caused by the composition components of the NCM battery.

[0014] The above upper voltage degradation characteristics are determined based on capacity degradation due to redox reactions of nickel and cobalt, and the above lower voltage degradation characteristics are determined based on capacity development due to redox reactions of manganese.

[0015] A battery management method according to one embodiment of the present invention comprises the steps of: acquiring battery data of a battery to be managed measured at a plurality of degradation points; generating a first SOC-OCV profile at a beginning of life (BOL) point and voltage-capacity profiles of the battery to be managed at the plurality of degradation points based on the battery data; identifying a boundary voltage that distinguishes an upper voltage degradation characteristic having an upper capacity degradation rate and a lower voltage degradation characteristic having a lower capacity degradation rate based on the voltage-capacity profiles; and estimating a second SOC-OCV profile at a middle of life (MOL) point based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

[0016] The battery data includes low-rate discharge data measured through low-rate discharge of about 0.1C or less of the managed battery at the plurality of degradation points, and the step of generating the voltage-capacity profiles includes the step of generating the voltage-capacity profiles based on the low-rate discharge data at the plurality of degradation points.

[0017] The step of generating the voltage-capacity profiles includes the step of generating dQ / dV profiles representing the differential value (dQ / dV) of capacity with respect to voltage at the plurality of degradation points based on the low-rate discharge data; and the step of generating the voltage-capacity profiles based on the dQ / dV profiles at the plurality of degradation points.

[0018] The step of identifying the boundary voltage includes the step of identifying the boundary voltage based on a pattern of the dQ / dV profiles.

[0019] The step of estimating the second SOC-OCV profile includes the step of applying the upper capacity degradation rate to the first SOC-OCV profile at the upper end of the boundary voltage and applying the lower capacity degradation rate to the first SOC-OCV profile at the lower end of the boundary voltage to generate a corrected SOC-OCV profile at the MOL point in time.

[0020] The step of estimating the second SOC-OCV profile includes a step of generating an interpolated SOC-OCV profile by performing interpolation for SOC units on the corrected SOC-OCV profile; and a step of estimating the second SOC-OCV profile by applying an OCV offset to the interpolated SOC-OCV profile.

[0021] The above-mentioned battery to be managed includes an NCM battery containing nickel, cobalt and manganese, and the above-mentioned upper voltage degradation characteristics and the above-mentioned lower voltage degradation characteristics are caused by the composition components of the NCM battery.

[0022] The above upper voltage degradation characteristics are determined based on capacity degradation due to redox reactions of nickel and cobalt, and the above lower voltage degradation characteristics are determined based on capacity development due to redox reactions of manganese.

[0023] According to one embodiment of the present invention, a non-transitory readable storage medium stores a program for executing the steps of: acquiring battery data of a target battery measured at a plurality of degradation points; generating a first SOC-OCV profile at a beginning of life (BOL) point and voltage-capacity profiles of the target battery at the plurality of degradation points based on the battery data; identifying a boundary voltage that distinguishes an upper voltage degradation characteristic having an upper capacity degradation rate and a lower voltage degradation characteristic having a lower capacity degradation rate based on the voltage-capacity profiles; and estimating a second SOC-OCV profile at a middle of life (MOL) point based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

[0024] According to the embodiments disclosed in this document, a battery management device and a battery management method can be provided that can estimate a SOC-OCV profile that changes due to degradation in an NCM cell having an atypical composition ratio.

[0025] The technical effects according to the embodiments disclosed in this document are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art according to the disclosure of this document.

[0026] The following drawings attached to this specification illustrate embodiments of the present invention and, together with the description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0027] FIG. 1 is a diagram illustrating elements constituting a battery management system according to some embodiments.

[0028] FIG. 2 is a diagram illustrating elements constituting a battery management device according to some embodiments.

[0029] Figure 3 is a graph illustrating an SOC-OCV profile that does not change even as degradation progresses in a conventional NCM battery cell.

[0030] Figure 4 is a graph illustrating capacity degradation that occurs uniformly over the entire voltage range in a conventional NCM battery cell.

[0031] FIG. 5 is a graph illustrating a SOC-OCV profile that changes due to degradation in a Mn-rich NCM battery cell according to some embodiments.

[0032] FIG. 6 is a graph illustrating capacity degradation that occurs differently in low voltage and high voltage regions in a Mn-rich NCM battery cell according to some embodiments.

[0033] FIG. 7 is a diagram illustrating how the SOC-OCV profile changes when a Mn-rich NCM battery cell degrades from the BOL point to the MOL point according to some embodiments.

[0034] FIG. 8 is a graph illustrating how the distinction between upper and lower voltages based on the boundary voltage according to some embodiments changes due to battery degradation.

[0035] FIG. 9 is a graph illustrating a comparison result between an estimated value of a second SOC-OCV profile and an actual measured value at the MOL point in time according to some embodiments.

[0036] FIG. 10 is a table illustrating a process for generating a second SOC-OCV profile according to some embodiments.

[0037] FIG. 11 is a flowchart illustrating steps of a battery management method according to some embodiments.

[0038] Hereinafter, embodiments described in this document are described with reference to the attached drawings. However, this is not intended to limit the disclosure of this document to specific embodiments, and it should be understood that various modifications, equivalents, and / or alternatives of the embodiments described in this document are included.

[0039] The embodiments and terminology used in this document are not intended to limit the technical features described in this document to a specific embodiment, but should be understood to encompass various modifications, equivalents, or alternatives of the embodiment. In connection with the description of the drawings, similar reference numerals may be used to refer to similar or related components. The singular form of a noun corresponding to an item may include one or more of the item, unless the context clearly indicates otherwise.

[0040] In this document, the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", "first", "second", "A", "B", "(a)", or "(b)" may be used merely to distinguish the corresponding component from other corresponding components, and do not limit the corresponding components in any other respect (e.g., importance or order) unless specifically stated otherwise.

[0041] In this document, when a component (e.g., a first component) is referred to as being “connected,” “coupled,” or “connected,” with or without the terms “functionally” or “communicatively,” or “coupled” or “connected,” it means that the component can be connected to the other component directly (e.g., wired or wirelessly), or indirectly (e.g., via a third component).

[0042] The methods according to various embodiments disclosed in this document may be provided as a computer program product. The computer program product may be traded as a commodity between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory, CD-ROM), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two driver devices. In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0043] According to the embodiments disclosed in this document, each component (e.g., a module or a program) of the above-described components may include a single or multiple entities, and some of the multiple entities may be separately arranged in other components. According to the embodiments disclosed in this document, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each component of the plurality of components in a manner identical to or similar to that performed by the corresponding component among the plurality of components prior to the integration.

[0044] According to embodiments disclosed in this document, operations performed by a module, program or other component may be performed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be performed in a different order, omitted, or one or more other operations may be added.

[0045] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0046] As used herein, the terms "about," "approximately," and "substantially" are used to mean a range of or near a numerical value or degree, taking into account inherent manufacturing and material tolerances.

[0047] An NCM battery cell may include nickel, cobalt, and manganese as cathode materials. For example, the cathode of an NCM cell may include LiNi x Mn n y Co z O 2 , where x + y + z = 1. Unlike such conventional NCM cells, a manganese (Mn)-rich cell may be utilized that additionally includes Li2MnO3 as a cathode material while having a higher Mn content. That is, the Mn-rich cell may include Li2MnO 3 -LiNi x Mn n y Co z O 2 , where x' + y' + z' = 1, and the Mn ratio may be high and the Co ratio may be extremely low.

[0048] In conventional NCM cells, the mapping relationship between the state of charge (SOC) and the open circuit voltage (OCV) may not be significantly affected by cell degradation. Therefore, in the case of conventional NCM cells, even if the SOC-OCV profile established at the beginning of life (BOL) is applied to the middle of life (MOL), the control algorithm of the battery management system (BMS) can operate normally. However, in the case of Mn-rich cells, changes in the SOC-OCV mapping relationship may occur due to cell degradation, and thus, the utilization of the SOC-OCV profile at the BOL may affect the control algorithm of the BMS, which may be problematic. In view of such problems, the present invention provides, for example, a battery management device and a battery management method capable of estimating a SOC-OCV profile that changes due to degradation in a Mn-rich NCM battery cell.

[0049] FIG. 1 may illustrate elements constituting a battery management system according to some embodiments.

[0050] Referring to FIG. 1, the system (100) may include a power usage device (110), a managed battery (120), and a battery management device (130). However, the present invention is not limited thereto, and some components may be omitted from the system (100) or other general-purpose components may be further included in the system (100).

[0051] The power usage device (110) may be configured to charge or discharge the managed battery (120). The power usage device (110) may discharge the managed battery (120) while consuming power, and may charge the managed battery (120) while generating power. According to an embodiment, the power usage device (110) may include a mobility device such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or an electric bike. The mobility device may drive a motor based on the power of the managed battery (120) or charge the managed battery (120) with power generated through regenerative braking.

[0052] The battery to be managed (120) may include a battery pack, etc., which is a diagnostic target of the system (100). The battery pack of the battery to be managed (120) may include a plurality of battery modules, and each battery module may include a plurality of battery cells. According to an embodiment, the battery to be managed (120) may be mounted on various types of mobility devices.

[0053] The battery management device (130) can perform operations for diagnosing or managing the battery (120) to be managed. The battery management device (130) can acquire battery data of the battery (120) to be managed and, based on the data, diagnose or manage the status of the battery (120) to be diagnosed. According to an embodiment, the battery management device (130) can include a battery management system (BMS) configured together with the battery (120) to be managed in an on-board manner, and / or an external device remotely placed from the battery (120) to be managed in an off-board manner. The external device can include a charger of a battery charging station, a battery diagnostic device, a cloud computing server, etc.

[0054] The system (100) may further include a management server (140). The management server (140) may manage the management results of the battery management device (130). The management server (140) may exchange data with the battery management device (130) via wired / wireless communication. When a defect of the managed battery (120) is diagnosed or its lifespan is predicted, the results may be transmitted to the management server (140) and recorded in a database. According to an embodiment, the battery management device (130) may perform diagnostic operations by executing battery management software, and the management server (140) may provide update information of the battery management software to the battery diagnosis device (130).

[0055] FIG. 2 may illustrate elements constituting a battery management device according to some embodiments.

[0056] Referring to FIG. 2, the battery management device (130) may include an interface (131) and a controller (132). However, the present invention is not limited thereto, and some components may be omitted from the battery management device (130), or other general-purpose components may be further included in the battery management device (130).

[0057] The interface (131) can obtain battery data of the battery to be managed (120). According to an embodiment, the interface (131) may include a communication unit (131-1) configured to receive battery data and / or a sensor unit (131-2) configured to measure battery data. According to an embodiment, when the battery management device (130) is implemented in an off-board form, the communication unit (131-1) can receive battery data in a wired data communication, wireless data communication, or the like. Alternatively, when the battery management device (130) is implemented in an on-board form, the sensor unit (131-2) can be configured to measure values ​​such as voltage, current, temperature, and resistance from the battery to be managed (120).

[0058] The controller (132) may have a structure for executing commands that implement the operations of the battery management device (130). The controller (132) may be implemented as an array of multiple logic gates for processing various operations or as a general-purpose microprocessor, and may be composed of a single processor or multiple processors. For example, the controller (132) may be implemented in the form of at least one of a microprocessor, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and an AP (Access Point).

[0059] The controller (132) can operate with a memory configured to store various data, commands, mobile applications, computer programs, etc. The memory can store operation data of various programs related to the operation of the system (100) for the operation of the controller (132). A plurality of such memories may be provided as needed. The memories may be configured separately from or integral with the controller (132). The controller (132) can process various operations by executing commands stored in the memory. For example, the memory may be implemented as a non-volatile device such as ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electronically Erasable Programmable Read-Only Memory), flash memory, PRAM (Phase-change Random Access Memory), MRAM (Magnetoresistive Random Access Memory), RRAM (Resistive Random Access Memory), FRAM (Ferroelectric Random Access Memory), or a volatile device such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), SDRAM (Synchronous Dynamic Random Access Memory), or may be implemented in the form of a HDD (Hard Disk Drive), SSD (Solid State Disk), SD (Secure Digital), Micro-SD, or a combination thereof.

[0060] The interface (131) may be configured to acquire battery data of a managed battery (120) measured at a plurality of degradation points. The plurality of degradation points may include points having a constant time interval and / or a constant charge / discharge cycle from a BOL point. The plurality of degradation points may include a MOL point, and the MOL point may be a point after, for example, 100 charge / discharge cycles. The battery data may include voltage, current, temperature, resistance, etc. of the managed battery (120). The interface (131) may include a communication unit (131-1) and / or a sensor unit (131-2), and the battery data may be received via the communication unit (131-1) or measured via the sensor unit (131-2).

[0061] The controller (132) may be configured to generate a first SOC-OCV profile at the beginning of life (BOL) based on battery data and voltage-capacity profiles of the managed battery (120) at multiple degradation points. The first SOC-OCV profile at the BOL may be generated in the form of a table, a curve, or the like based on a mapping relationship of SOC values ​​corresponding to each unit OCV value. For example, the unit OCV values ​​may be formed at 10% intervals, such as 100%, 90%, 80%, etc., and the specific numerical values ​​may be changed as needed. The voltage-capacity profile may include a graph, a curve, or the like showing how the capacity (Q) and / or the rate of change of capacity with respect to voltage (dQ / dV) changes when the cell voltage (V) changes. Refer to FIG. 6, which will be described later, for the voltage-capacity profile.

[0062] The controller (132) may be configured to identify a boundary voltage that distinguishes an upper voltage degradation characteristic with an upper capacity degradation rate and a lower voltage degradation characteristic with a lower capacity degradation rate based on voltage-capacity profiles. When voltage-capacity profiles at multiple degradation points are displayed together, the tendency of the degradation characteristic may vary based on a specific voltage, and that voltage may be selected as the boundary voltage. An upper voltage degradation characteristic may appear in an upper voltage region higher than the boundary voltage, and a lower voltage degradation characteristic may appear in a lower voltage region lower than the boundary voltage. When battery degradation progresses from the BOL point to the MOL point, the upper voltage region may degrade by the upper capacity degradation rate, and the lower voltage region may degrade by the lower capacity degradation rate. With respect to the boundary voltage, reference may be made to FIG. 6, which will be described later.

[0063] The controller (132) may be configured to estimate a second SOC-OCV profile at the mid-life (MOL) point in time based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile. Since different degradation characteristics appear in the upper voltage region and the lower voltage region, in order to estimate the second SOC-OCV profile at the MOL point in time, it may be necessary to separately apply the upper capacity degradation rate and the lower capacity degradation rate to the upper voltage region and the lower voltage region. After applying the upper capacity degradation rate and the lower capacity degradation rate to the first SOC-OCV profile and then performing an additional correction process, the second SOC-OCV profile at the MOL point in time can be generated.

[0064] According to an embodiment, the battery data may include low-rate discharge data measured through low-rate discharge of about 0.1 C or less of the managed battery (100) at a plurality of degradation points, and the controller (132) may be configured to generate voltage-capacity profiles based on the low-rate discharge data at the plurality of degradation points. For example, the voltage-capacity profiles illustrated in FIG. 6 may be measured based on low-rate discharge, and the low-rate discharge may be performed with a discharge current of about 0.1 C or less. For example, the low-rate discharge current may be about 0.5 C, about 0.33 C, etc. Voltage, current, temperature, resistance, etc. according to low-rate discharge at a plurality of degradation points may be measured, and based on these, capacity (Q) and dQ / dV, etc. may be calculated.

[0065] According to an embodiment, the controller (132) may be configured to generate dQ / dV profiles representing the derivative of capacity with respect to voltage (dQ / dV) at a plurality of degradation points based on low-rate discharge data, and to generate voltage-capacity profiles based on the dQ / dV profiles at the plurality of degradation points. Voltage, current, temperature, resistance, etc. at a plurality of degradation points may be measured through low-rate discharge, and a capacity (Q) value may be calculated based on these through a calculation algorithm. A dQ / dV value may be calculated by differentiating the capacity (Q) value with respect to voltage, and a dQ / dV profile may be generated by plotting the dQ / dV value with respect to voltage (V). The voltage-capacity profiles may include the dQ / dV profiles at the plurality of degradation points.

[0066] In an embodiment, the controller (132) may be configured to identify a boundary voltage based on a pattern of dQ / dV profiles. For example, a region in which the dQ / dV profiles exhibit an increasing pattern for multiple degeneration points and a region in which the dQ / dV profiles exhibit a decreasing pattern for multiple degeneration points may be distinguished, and a voltage value near a location where such distinction occurs may be set as a boundary voltage.

[0067] According to an embodiment, the controller (132) may be configured to generate a corrected SOC-OCV profile at the MOL point by applying an upper capacity degradation rate to the first SOC-OCV profile at an upper portion of the boundary voltage and applying a lower capacity degradation rate to the first SOC-OCV profile at a lower portion of the boundary voltage. If the NCM cell is a Mn-rich cell, applying the SOC-OCV profile at the BOL point to the MOL point may cause distortion. Therefore, the correction may be performed by applying the capacity degradation rates to the first SOC-OCV profile at the BOL point, and the correction may be performed independently for the upper and lower portions based on the boundary voltage.

[0068] According to an embodiment, the controller (132) may be configured to generate an interpolated SOC-OCV profile by performing interpolation on the SOC unit of the corrected SOC-OCV profile, and to estimate a second SOC-OCV profile by applying an OCV offset to the interpolated SOC-OCV profile. Interpolation and offset may be referred to FIG. 11, which will be described later. The interpolation operation may resolve mismatching caused by correction of reference SOC values ​​at the BOL point in time. The offset operation may increase the accuracy of the second SOC-OCV profile by adjusting all values ​​at once.

[0069] According to an embodiment, the battery to be managed (120) may include an NCM battery including nickel, cobalt, and manganese, and the upper voltage degradation characteristics and the lower voltage degradation characteristics may be caused by the composition components of the NCM battery. For example, the voltage range-specific degradation characteristics of the NCM battery may be determined based on the voltage range in which the oxidation and reduction of nickel primarily occurs, the voltage range in which the oxidation and reduction of cobalt primarily occurs, and the voltage range in which the oxidation and reduction of manganese primarily occurs.

[0070] In an embodiment, the upper voltage degradation characteristic may be determined based on capacity degradation due to redox reactions of nickel and cobalt, and the lower voltage degradation characteristic may be determined based on capacity development due to redox reactions of manganese. In an embodiment, the NCM battery may be a manganese-rich NCM battery, and the oxidation and reduction of a high content of manganese may have a main effect on the lower part of the boundary voltage, and the oxidation / reduction of nickel and cobalt may have a main effect on the upper part of the boundary voltage.

[0071] Figure 3 illustrates an SOC-OCV profile that does not change even as degradation progresses in a conventional NCM battery cell.

[0072] Referring to FIG. 3, a graph (300) can be illustrated illustrating a SOC-OCV profile that does not change even as degradation progresses in a conventional NCM battery cell.

[0073] In the graph (300), the closed circuit voltage (CCV) at approximately 1C may have different profiles at the BOL and MOL points, which may be due to increased resistance caused by battery degradation. On the other hand, in conventional NCM battery cells that do not contain a high manganese content, the SOC-OCV profile may not change even if battery degradation progresses.

[0074] Figure 4 illustrates capacity degradation that occurs uniformly over the entire voltage range in a conventional NCM battery cell.

[0075] Referring to FIG. 4, a graph (400) illustrating capacity degradation that occurs uniformly over the entire voltage range in a conventional NCM battery cell can be illustrated.

[0076] In graph (400), capacity degradation may occur relatively uniformly over the entire voltage range, and thus the SOC-OCV profile may not have a large difference between the BOL and MOL points.

[0077] FIG. 5 illustrates the SOC-OCV profiles that change due to degradation in a Mn-rich NCM battery cell according to some embodiments.

[0078] Referring to FIG. 5, a graph (500) illustrating a SOC-OCV profile that changes due to degradation in a Mn-rich NCM battery cell may be illustrated. The graph (500) may represent a Mn-rich NCM cell.

[0079] In the Mn-rich NCM cell of graph (500), the closed circuit voltage (CCV) of about 0.33 C may degrade at the MOL point compared to the BOL point. In addition, the OCV may also degrade at the MOL point compared to the BOL point. Therefore, in the case of the Mn-rich NCM cell, it may be difficult to directly utilize the SOC-OCV profile generated at the BOL point at the MOL point.

[0080] FIG. 6 illustrates capacity degradation that occurs differently in low voltage and high voltage regions in a Mn-rich NCM battery cell according to some embodiments.

[0081] Referring to FIG. 6, a graph (600) can be illustrated illustrating capacity degradation that occurs differently in low voltage and high voltage regions in a Mn-rich NCM battery cell.

[0082] In the graph (600), about 3 V can be selected as a boundary voltage, and a lower voltage region and an upper voltage region can be distinguished through the boundary voltage. In the lower voltage region, dQ / dV values ​​may decrease as degradation progresses, whereas in the upper voltage region, dQ / dV values ​​may increase as degradation progresses. In the lower voltage region, manganese redox may have a major influence due to the high manganese content, and in the upper voltage region, nickel and cobalt redox may have a major influence.

[0083] FIG. 7 illustrates how the SOC-OCV profile changes when a Mn-rich NCM battery cell is degraded from the BOL point to the MOL point according to some embodiments.

[0084] Referring to FIG. 7, the mapping relationship between OCV and SOC can be illustrated at the BOL point (710) and the MOL point (720). At the BOL point (710) and the MOL point (720), the OCV can be divided into an upper voltage region and a lower voltage region based on a boundary voltage of 3 V. For example, the MOL point (720) can be a point after 100 charge / discharge cycles have been performed.

[0085] First, the full capacity of the NCM cell at the BOL time point (710) may be 38.68 Ah, and the degraded full capacity of the NCM cell at the MOL time point (720) may be 34.55 Ah. Second, the boundary voltage of 3 V at the BOL time point (710) may correspond to 5.05 Ah and a SOC of 13%, and the boundary voltage of 3 V at the MOL time point (720) may correspond to 5.5 Ah and a SOC of 16%. Third, the upper voltage region at the BOL time point (710) may correspond to 33.63 Ah, and the upper voltage region at the MOL time point (720) may correspond to 29.05 Ah.

[0086] The total capacity of 34.55 Ah at the MOL point (720) may be 89.3% of the total capacity of 38.68 Ah at the BOL point (710). The capacity of 29.05 Ah at the upper voltage region at the MOL point (720) may be 86.4% of 33.63 Ah at the upper voltage region at the BOL point (710). The capacity of 5.5 Ah at the lower voltage region at the MOL point (720) may be 108.9% of 5.05 Ah at the lower voltage region at the BOL point (710).

[0087] In this case, the upper capacity degradation rate of the upper voltage region may be 89.3 / 86.4 = 1.034, and the lower capacity degradation rate of the lower voltage region may be 89.3 / 108.9 = 0.819. Therefore, the OCV value corresponding to SOC 90% (=DOD 10%) at the BOL time point (710) may correspond to DOD (Depth of Discharge) 10% * 1.034 = DOD 10.34% (=SOC 89.66%) at the MOL time point (720). In this manner, the SOC-OCV profile at the MOL time point (720) can be reconstructed using the SOC-OCV profile at the BOL time point (710).

[0088] FIG. 8 illustrates a form in which the distinction between upper and lower voltages based on the boundary voltage according to some embodiments changes due to battery degradation.

[0089] Referring to FIG. 8, a graph (800) representing a first SOC-OCV profile at the BOL point and a second SOC-OCV profile at the MOL point can be illustrated.

[0090] Graph (800) may indicate that the SOC-OCV profile may change as degradation progresses from the BOL point to the MOL point. The upper voltage region and the lower voltage region may be distinguished based on a boundary voltage of 3 V. The ratio of the distinction between the upper voltage region and the lower voltage region may change due to degradation from the BOL point to the MOL point.

[0091] FIG. 9 illustrates a comparison result between an estimated value of a second SOC-OCV profile and an actual measured value at the MOL point in time according to some embodiments.

[0092] Referring to FIG. 9, a graph (900) illustrating a comparison result between an estimated value of a second SOC-OCV profile and an actual measured value at the MOL point in time can be illustrated.

[0093] In the graph (900), BOL_EXP may represent a first SOC-OCV profile measured at the BOL point, and 100Cycle_EXP may represent a measured SOC-OCV profile measured at the MOL point. As illustrated, it can be confirmed that there is a difference between the two in the Mn-rich NCM cell. However, since it takes a lot of time and cost to generate the SOC-OCV profile at the MOL point through actual measurement every time, a technique that can estimate it instead of actual measurement may be needed.

[0094] By applying the upper capacity degradation rate and the lower capacity degradation rate to the first SOC-OCV profile (BOL_EXP), a corrected SOC-OCV profile (BOL_CorrectionDODApplied) can be generated, and a second SOC-OCV profile (BOL_2ndCorrection) can be generated by a second correction that collectively applies an offset to the generated corrected SOC-OCV profile. As illustrated, it can be confirmed that there is no significant difference between the second SOC-OCV profile (BOL_2ndCorrection) and the actually measured SOC-OCV profile (100Cycle_EXP).

[0095] Figure 10 illustrates a process for generating a second SOC-OCV profile according to some embodiments.

[0096] Referring to FIG. 10, a table (1000) illustrating a process for generating a second SOC-OCV profile may be illustrated.

[0097] The first and second columns of the table (1000) may represent a first SOC-OCV profile at the BOL point of time. The first SOC-OCV profile is generated in units of 10% SOC, but may be generated in units different from this, if necessary. The third column of the table (1000) may represent a SOC-OCV profile actually measured at the MOL point of time, and generating an estimated profile similar to this may be one of the purposes of the present invention.

[0098] The fifth column of the table (1000) may represent a corrected SOC-OCV profile generated by applying the upper capacity degradation rate and the lower capacity degradation rate to the first SOC-OCV profile. The upper capacity degradation rate and the lower capacity degradation rate of the fourth column may be utilized to generate the corrected SOC-OCV profile of the fifth column.

[0099] The 6th column of the table (1000) may represent an interpolated SOC-OCV profile generated by performing interpolation on the corrected SOC-OCV profile. The 7th column of the table (1000) may represent a second SOC-OCV profile generated by uniformly shifting the interpolated SOC-OCV profile by a specific offset value. As illustrated, it can be confirmed that there is not a large difference between the second SOC-OCV profile of the 7th column and the actually measured SOC-OCV profile of the 3rd column.

[0100] FIG. 11 illustrates steps of a battery management method according to some embodiments.

[0101] Referring to FIG. 11, the battery management method (1100) may include steps (1110) to (1140). However, the present invention is not limited thereto, and some steps may be omitted or other general steps may be added, and the steps of the battery management method (1100) may be executed in a different order than the illustrated order.

[0102] The battery management method (1100) may be composed of steps that are processed in a time-series manner in the battery management device (130). Therefore, even if the content is omitted below, the content described above for the battery management device (130) may be equally applied to the battery management method (1100).

[0103] Steps (1110) to (1140) of the battery management method (1100) can be performed by the interface (131) and controller (132) of the battery management device (130).

[0104] In step (1110), the battery management device (130) may perform a step of acquiring battery data of a battery to be managed measured at multiple degradation points.

[0105] In step (1120), the battery management device (130) may perform a step of generating a first SOC-OCV profile at the beginning of life (BOL) and voltage-capacity profiles of the managed battery at multiple degradation points based on battery data.

[0106] In step (1130), the battery management device (130) may perform a step of identifying a boundary voltage that distinguishes an upper voltage degradation characteristic having an upper capacity degradation rate and a lower voltage degradation characteristic having a lower capacity degradation rate based on voltage-capacity profiles.

[0107] In step (1140), the battery management device (130) may perform a step of estimating a second SOC-OCV profile at the mid-life (MOL) point in time based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

[0108] According to an embodiment, the battery management method (1100) may be implemented in the form of a computer program stored on a computer-readable storage medium. That is, the computer program may include instructions for implementing the battery management method (1100), and the program instructions may be stored on the computer-readable storage medium. The computer program may include a mobile application.

[0109] According to an embodiment, the computer-readable storage medium may include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs, DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute computer program instructions such as ROMs, RAMs, flash memories, and the like. The computer program instructions may include machine language codes generated by a compiler and high-level language codes that can be executed by a computer using an interpreter, etc.

[0110] The terms "include," "comprise," or "have" used herein, unless otherwise specifically stated, imply that the corresponding component may be included, and therefore should be interpreted to include other components rather than to exclude other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments disclosed in this document pertain, unless otherwise defined. Commonly used terms, such as terms defined in dictionaries, should be interpreted to be consistent with their contextual meaning in the relevant art, and shall not be interpreted in an idealized or overly formal sense, unless explicitly defined in this document.

[0111] The above description is merely an illustrative description of the technical idea disclosed in this document, and those skilled in the art to which the embodiments disclosed in this document pertain may make various modifications and variations without departing from the essential characteristics of the embodiments disclosed in this document. Therefore, the embodiments disclosed in this document are not intended to limit the technical idea of ​​the embodiments disclosed in this document, but to explain it, and the scope of the technical idea disclosed in this document is not limited by these embodiments. The protection scope of the technical idea disclosed in this document should be interpreted by the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the rights of this document. Therefore, the technical scope of the various embodiments of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Claims

1. An interface configured to obtain battery data of a managed battery measured at multiple degradation points; and Generating a first SOC-OCV profile at the beginning of life (BOL) and voltage-capacity profiles of the managed battery at the plurality of degradation points based on the battery data, Based on the above voltage-capacity profiles, a boundary voltage is identified that distinguishes an upper voltage degradation characteristic with an upper capacity degradation rate and a lower voltage degradation characteristic with a lower capacity degradation rate, A battery management device comprising a controller configured to estimate a second SOC-OCV profile at a mid-life (MOL) point in time based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

2. In paragraph 1, The above battery data includes low-rate discharge data measured through low-rate discharge of 0.1C or less of the managed battery at the plurality of degradation points, A battery management device, wherein the controller is configured to generate the voltage-capacity profiles based on the low-rate discharge data at the plurality of degradation points.

3. In paragraph 2, The controller generates dQ / dV profiles representing the differential value of capacity with respect to voltage (dQ / dV) at the plurality of degradation points based on the low-rate discharge data, A battery management device configured to generate the voltage-capacity profiles based on the dQ / dV profiles at the plurality of degradation points.

4. In paragraph 3, A battery management device, wherein the controller is configured to identify the boundary voltage based on a pattern of the dQ / dV profiles.

5. In paragraph 1, A battery management device, wherein the controller is configured to generate a corrected SOC-OCV profile at the MOL point in time by applying the upper capacity degradation rate to the first SOC-OCV profile at an upper portion of the boundary voltage and applying the lower capacity degradation rate to the first SOC-OCV profile at a lower portion of the boundary voltage.

6. In paragraph 5, The above controller generates an interpolated SOC-OCV profile by performing interpolation for SOC units on the above corrected SOC-OCV profile, A battery management device configured to estimate the second SOC-OCV profile by applying an OCV offset to the interpolated SOC-OCV profile.

7. In paragraph 1, The above-mentioned managed battery includes an NCM battery containing nickel, cobalt and manganese, A battery management device in which the above upper voltage degradation characteristics and the above lower voltage degradation characteristics are caused by the composition components of the NCM battery.

8. In paragraph 7, A battery management device, wherein the upper voltage degradation characteristic is determined based on capacity degradation due to redox of nickel and cobalt, and the lower voltage degradation characteristic is determined based on capacity development due to redox of manganese.

9. A step of acquiring battery data of a battery to be managed measured at multiple degradation points; A step of generating a first SOC-OCV profile at the beginning of life (BOL) and voltage-capacity profiles of the managed battery at the plurality of degradation points based on the battery data; A step of identifying a boundary voltage that distinguishes an upper voltage degradation characteristic having an upper capacity degradation rate and a lower voltage degradation characteristic having a lower capacity degradation rate based on the voltage-capacity profiles; and A battery management method, comprising the step of estimating a second SOC-OCV profile at the mid-life (MOL) point in time based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

10. In paragraph 9, The above battery data includes low-rate discharge data measured through low-rate discharge of 0.1C or less of the managed battery at the plurality of degradation points, The step of generating the above voltage-capacity profiles is: A battery management method comprising the step of generating the voltage-capacity profiles based on the low-rate discharge data at the plurality of degradation points.

11. In paragraph 10, The step of generating the above voltage-capacity profiles is: A step of generating dQ / dV profiles representing the differential value of capacity with respect to voltage (dQ / dV) at the plurality of degradation points based on the low-rate discharge data; and A battery management method comprising the step of generating the voltage-capacity profiles based on the dQ / dV profiles at the plurality of degradation points.

12. In paragraph 11, The step of identifying the above boundary voltage is: A battery management method comprising a step of identifying the boundary voltage based on a pattern of the dQ / dV profiles.

13. In paragraph 9, The step of estimating the second SOC-OCV profile is: A battery management method, wherein the controller includes a step of applying the upper capacity degradation rate to the first SOC-OCV profile at an upper portion of the boundary voltage and applying the lower capacity degradation rate to the first SOC-OCV profile at a lower portion of the boundary voltage to generate a corrected SOC-OCV profile at the MOL point in time.

14. In paragraph 13, The step of estimating the second SOC-OCV profile is: A step of generating an interpolated SOC-OCV profile by performing interpolation for SOC units on the above-mentioned corrected SOC-OCV profile; and A battery management method comprising a step of estimating the second SOC-OCV profile by applying an OCV offset to the interpolated SOC-OCV profile.

15. In paragraph 9, The above-mentioned managed battery includes an NCM battery containing nickel, cobalt and manganese, A battery management method wherein the above upper voltage degradation characteristics and the above lower voltage degradation characteristics are caused by the composition components of the NCM battery.

16. In paragraph 15, A battery management method, wherein the upper voltage degradation characteristic is determined based on capacity degradation due to redox of nickel and cobalt, and the lower voltage degradation characteristic is determined based on capacity development due to redox of manganese.

17. A step of acquiring battery data of a battery to be managed measured at multiple degradation points; A step of generating a first SOC-OCV profile at the beginning of life (BOL) and voltage-capacity profiles of the managed battery at the plurality of degradation points based on the battery data; A step of identifying a boundary voltage that distinguishes an upper voltage degradation characteristic having an upper capacity degradation rate and a lower voltage degradation characteristic having a lower capacity degradation rate based on the voltage-capacity profiles; and A non-transitory readable storage medium storing a program for executing a step of estimating a second SOC-OCV profile at a mid-life (MOL) point in time based on the upper capacity degradation rate, the lower capacity degradation rate, and the first SOC-OCV profile.

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