SOH Estimation Apparatus and Method

Abstract

An SOH estimation device according to one embodiment of the present invention includes: a profile acquisition unit configured to acquire OCV profiles showing multiple OCVs of a battery measured at different time points; a profile correction unit configured to generate an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting a preset reference positive electrode profile and a reference negative electrode profile to correspond to the OCV profiles; and a control unit configured to extract diagnostic factors of the battery from at least one of the adjusted positive electrode profile and the adjusted negative electrode profile, and to estimate the SOH of the battery based on the extracted diagnostic factors.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2023-0115852 filed on August 31, 2023, and all the contents disclosed in the specification and drawings of the said application are incorporated into this application.

[0002] The present invention relates to a State of Health (SOH) estimation device and method, and more particularly, to an SOH estimation device and method for estimating the SOH of a battery using an Open Circuit Voltage (OCV).

Background Art

[0003] In recent years, with the rapid growth in the demand for portable electronic products such as notebook computers, video cameras, and mobile phones, and the full-scale development of electric vehicles, energy storage batteries, robots, artificial satellites, etc., research on high-performance rechargeable batteries has been actively conducted.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among these, lithium batteries have attracted attention because they have almost no memory effect compared to nickel-based batteries, are freely chargeable and dischargeable, have a very low self-discharge rate, and have a high energy density.

[0005] Although various studies have been conducted on such batteries from the perspectives of increasing capacity and density, the perspectives of improving lifespan and safety are also important. In order to improve the safety of the battery, the current state of the battery must be accurately diagnosed.

[0006] Conventionally, the state of a battery has been diagnosed by analyzing a battery profile showing the correspondence between the capacity and voltage of the battery. For example, during the charging process of the battery, the capacity and voltage are measured, and the state of the battery is diagnosed through analysis of the battery profile showing the correspondence between the measured capacity and voltage. As another example, the state of the battery may be diagnosed based on the capacity and voltage measured during the discharging process of the battery.

[0007] Here, in order to more accurately diagnose the current state of the battery, a battery profile that accurately reflects the current state of the battery is required. However, there is a problem that low-rate charge and discharge such as 0.05C (C-rate) is necessary to obtain such a battery profile. That is, conventionally, low-rate charge and discharge is required to diagnose the state of the battery, so there are limitations in diagnosing the state of the battery. For example, it takes about 20 hours to fully charge the battery at 0.05C. Therefore, there is a problem that a considerable amount of time is required to diagnose the state of the battery by conventional low-rate charge and discharge.

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention was devised to solve the above problems, and an object thereof is to provide a SOH estimation device and method for estimating the SOH of a battery using OCV.

[0009] Other objects and advantages of the present invention can be understood from the following description and will be more clearly understood from the embodiments of the present invention. Also, the objects and advantages of the present invention can be realized by the means and combinations thereof shown in the claims.

Means for Solving the Problems

[0011] The multiple OCVs may be configured to include the OCV measured when the battery switches from a resting state to a discharge state, and the OCV measured while the state in which the discharge current of the battery is below a preset threshold current is maintained for a preset reference time or longer.

[0012] The multiple OCVs may be configured to include multiple OCVs measured within a predetermined reference period.

[0013] The aforementioned reference period may be set to a period based on a predetermined target period, the period required to measure a predetermined number of OCVs, the period required for the SOH of the battery to decrease by a predetermined reference SOH, or a period based on a combination thereof.

[0014] The profile correction unit may be configured to generate a comparative full-cell profile based on the reference positive electrode profile and the reference negative electrode profile, and to adjust the reference positive electrode profile and the reference negative electrode profile until the generated comparative full-cell profile corresponds to the OCV profile, thereby generating the adjusted positive electrode profile and the adjusted negative electrode profile.

[0015] The profile correction unit may be configured to determine a target capacity range corresponding to the OCV profile and to compare the comparison full cell profile and the OCV profile within the target capacity range.

[0016] The control unit may be configured to estimate the State of Health (SOH) of the battery by comparing a preset reference value for the diagnostic factor with the value of the diagnostic factor.

[0017] The control unit may be configured to estimate at least one of the positive electrode SOH, negative electrode SOH, available lithium SOH, and capacity SOH of the battery, depending on the type of diagnostic factor.

[0018] The control unit may be configured to extract at least one of the positive electrode factors based on the adjusted positive electrode profile and the negative electrode factors based on the adjusted negative electrode profile as the diagnostic factor.

[0019] The positive electrode factor may be configured to include at least one of the positive electrode engagement start point, positive electrode engagement end point, and positive electrode change ratio of the battery, based on the adjusted positive electrode profile.

[0020] The negative electrode factor may be configured to include at least one of the following: the negative electrode engagement start point, the negative electrode engagement end point, and the negative electrode change ratio of the battery, based on the adjusted negative electrode profile.

[0021] The control unit may be configured to adjust the battery usage conditions based on the estimated SOH.

[0022] A battery pack according to another aspect of the present invention includes a SOH estimation device according to one aspect of the present invention.

[0023] An automobile according to yet another aspect of the present invention includes a SOH estimation device according to one aspect of the present invention.

[0024] A server according to yet another aspect of the present invention includes a SOH estimation device according to one aspect of the present invention.

[0025] A method for estimating SOH according to yet another aspect of the present invention includes: a profile acquisition step of acquiring multiple OCV profiles showing multiple OCVs of a battery measured at different time points; a profile adjustment step of adjusting a preset reference positive electrode profile and a reference negative electrode profile to correspond to the OCV profiles to generate an adjusted positive electrode profile and an adjusted negative electrode profile; a diagnostic factor extraction step of extracting diagnostic factors of the battery from at least one of the adjusted positive electrode profile and the adjusted negative electrode profile; and an SOH estimation step of estimating the SOH of the battery based on the extracted diagnostic factors. [Effects of the Invention]

[0026] A SOH estimation device according to one aspect of the present invention can quickly estimate the SOH of a battery based on the OCV profile without restricting the use of the battery.

[0027] Furthermore, the SOH estimation device according to one aspect of the present invention can diagnose the state of the battery from various perspectives based on the types of extractable diagnostic factors.

[0028] The effects of the present invention are not limited to those described above, and other effects of the present invention not mentioned herein will be clearly understood by those skilled in the art from the claims.

[0029] The drawings accompanying this specification, along with the detailed description of the invention described below, are intended to further facilitate understanding of the technical concept of the present invention, and the present invention is not to be construed as being limited only to the matters described in the drawings. [Brief explanation of the drawing]

[0030] [Figure 1] This figure schematically shows a SOH estimation device according to one embodiment of the present invention. [Figure 2] This figure schematically shows the OCV profile according to one embodiment of the present invention. [Figure 3] This figure shows the OCV of a battery measured by one embodiment of the present invention. [Figure 4] This figure schematically shows the reference positive electrode profile and reference negative electrode profile according to one embodiment of the present invention. [Figure 5] This figure schematically shows a comparative full-cell profile according to one embodiment of the present invention. [Figure 6] This figure schematically shows the comparative full-cell profile and OCV profile according to one embodiment of the present invention. [Figure 7] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 8] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 9] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 10] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 11] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 12] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 13] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 14] This figure illustrates the process by which a reference positive electrode profile and a reference negative electrode profile are adjusted according to one embodiment of the present invention. [Figure 15]This figure shows an exemplary configuration of a battery pack according to another embodiment of the present invention. [Figure 16] This figure shows an exemplary configuration of an automobile according to yet another embodiment of the present invention. [Figure 17] This figure schematically illustrates a method for estimating SOH according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0031] The terms and words used in this specification and in the claims are not to be interpreted in a manner limited to their general and dictionary meanings, but rather in a manner corresponding to the technical idea of ​​the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best describe their invention.

[0032] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the invention. It should be understood that there are various equivalents and modifications that can substitute for them at the time of filing this application.

[0033] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would obscure the gist of the present invention, such detailed description will be omitted.

[0034] Terms that include ordinal numbers, such as "1st," "2nd," etc., are used to distinguish one of several components from others, and these terms do not limit the components themselves.

[0035] Whenever a part of the specification is described as "including" or "equipping" a component, unless otherwise specified, this does not exclude other components, but rather means that other components may be included.

[0036] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only "direct connections" but also "indirect connections" that involve other elements.

[0037] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0038] Figure 1 is a schematic diagram showing a State of Health (SOH) estimation device 100 according to one embodiment of the present invention.

[0039] Referring to Figure 1, the SOH estimation device 100 includes a profile acquisition unit 110, a profile correction unit 120, and a control unit 130.

[0040] The profile acquisition unit 110 may be configured to acquire an OCV profile Rocv that shows multiple OCVs (Open Circuit Voltages) of the battery measured at different points in time.

[0041] Here, "battery" refers to a single, physically separable, independent cell equipped with a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium-polymer battery may be considered a battery. The type of battery can be cylindrical, prismatic, or pouch-type. Furthermore, "battery" may also refer to a battery bank, battery module, or battery pack in which multiple cells are connected in series and / or parallel. For the sake of explanation, in the following, "battery" will be described as referring to a single, independent cell.

[0042] Here, the OCV profile Rocv is a profile that shows the correspondence between the battery's OCV and capacity. Specifically, the battery's OCV may be measured at a point in time when certain conditions are met. More specifically, multiple OCVs may be configured to include the OCV measured when the battery switches from a dormant state to a discharge state, and the OCV measured while the battery's discharge current remains below a predetermined threshold current for a predetermined reference time or longer.

[0043] First, the OCV of a battery can be measured at the point when the battery switches from a dormant state to a discharged state. Here, the dormant state means that the battery has been kept under no load for a certain period of time and has stabilized. For example, if the battery is installed in a car, the OCV of the battery can be measured at the point when the engine of a car that has been parked for a certain period of time is turned on (key on). Then, the capacity of the battery can be determined by the capacity at the point when the car engine is turned off (key off).

[0044] Next, the OCV of a battery can be measured while the battery's discharge current remains below a predetermined threshold current for a predetermined reference time or longer. Here, the state in which the battery's discharge current is below the threshold current means a state in which the amount of battery discharge is negligible. That is, if the battery is in a discharge state but the amount of discharge is small, the measured battery voltage can be estimated as the OCV. This is because, if the amount of battery discharge is at a negligible level, the battery is considered to be in a stable state even if it has been discharging for longer than the reference time. For example, if a battery is installed in a car and the car is parked for longer than the reference time, the battery may continuously discharge to supply power to electrical components. However, the amount of battery discharge to supply power to electrical components is at a very small level relative to the battery's capacity. Therefore, even though the battery is actually in a discharge state, the battery voltage can be estimated as the OCV.

[0045] Figure 2 is a schematic diagram of the OCV profile Rocv according to one embodiment of the present invention. Referring to Figure 2, the OCV profile Rocv shows the correspondence between the OCV and capacity of a battery in the capacity range of 10Ah to 45Ah. As mentioned above, since the conditions under which the OCV is measured are restrictive, the multiple OCVs included in the OCV profile Rocv may be discontinuous.

[0046] For example, the profile acquisition unit 110 can directly receive the OCV profile Rocv from an external source. That is, the profile acquisition unit 110 can acquire the OCV profile Rocv by receiving it via a wired and / or wireless connection to an external source.

[0047] As another example, the profile acquisition unit 110 can receive battery information regarding the battery's OCV (V) and capacity (Q). The profile acquisition unit 110 can then generate an OCV profile Rocv based on the received battery information. In other words, the profile acquisition unit 110 can acquire an OCV profile Rocv by directly generating the OCV profile Rocv based on the battery information.

[0048] The profile acquisition unit 110 may be connected to the profile correction unit 120 in a communicative manner. For example, the profile acquisition unit 110 may be connected to the profile correction unit 120 by wire and / or wirelessly. The profile acquisition unit may transmit the acquired OCV profile Rocv to the profile correction unit 120.

[0049] The profile correction unit 120 may be configured to generate an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting a preset reference positive electrode profile Rp and reference negative electrode profile Rn to correspond to the OCV profile Rocv.

[0050] The reference positive electrode profile Rp may be a profile that shows the correspondence between the capacity and OCV of a reference positive electrode cell, pre-configured to correspond to the positive electrode of the battery. For example, the reference positive electrode cell may be a positive coin half-cell or the positive electrode of a tri-electrode cell. The reference negative electrode profile Rn may be a profile that shows the correspondence between the capacity and OCV of a reference negative electrode cell, pre-configured to correspond to the negative electrode of the battery. For example, the reference negative electrode cell may be a negative coin half-cell or the negative electrode of a tri-electrode cell.

[0051] Specifically, the profile correction unit 120 can adjust the reference positive electrode profile Rp and the reference negative electrode profile Rn to correspond to the OCV profile Rocv. More specifically, the profile correction unit 120 can adjust the reference positive electrode profile Rp and the reference negative electrode profile Rn to generate an adjusted positive electrode profile and an adjusted negative electrode profile. Then, the profile correction unit 120 can generate a comparative full-cell profile S from the adjusted positive electrode profile and the adjusted negative electrode profile. The profile correction unit 120 can adjust the reference positive electrode profile Rp and the reference negative electrode profile Rn until the comparative full-cell profile S corresponds to the OCV profile Rocv. Here, the target capacity range (T) of the OCV profile Rocv may differ from the capacity range of the comparative full-cell profile S. Therefore, the reference positive electrode profile Rp and the reference negative electrode profile Rn can be adjusted depending on the correspondence between the comparative full-cell profile S and the OCV profile Rocv in the target capacity range (T).

[0052] For example, the profile correction unit 120 can generate multiple comparison full cell profiles S by shifting or capacitance scaling the reference positive electrode profile Rp and the reference negative electrode profile Rn, and identify the comparison full cell profile S from among the multiple comparison full cell profiles S that minimizes the error with the OCV profile Rocv. Then, the adjusted positive electrode profile and adjusted negative electrode profile corresponding to the identified comparison full cell profile S can be determined.

[0053] In this regard, a more specific embodiment of how the profile correction unit 120 adjusts the reference positive electrode profile Rp and reference negative electrode profile Rn to correspond to the OCV profile Rocv in order to determine the positive electrode profile of the battery will be described later with reference to Figures 7 to 14.

[0054] The control unit 130 may be configured to extract battery diagnostic factors from at least one of the regulated positive electrode profile and the regulated negative electrode profile.

[0055] Specifically, the control unit 130 can extract diagnostic factors related to the positive electrode from the adjusted positive electrode profile. Furthermore, the control unit 130 can extract diagnostic factors related to the negative electrode from the adjusted negative electrode profile. For the sake of clarity, specific embodiments of the diagnostic factors will be described later.

[0056] The control unit 130 may be configured to estimate the battery's state of health (SOH) based on the extracted diagnostic factors.

[0057] Specifically, the control unit 130 may be configured to estimate the battery's State of Health (SOH) by comparing a preset reference value for a diagnostic factor with the value of the diagnostic factor.

[0058] Here, the pre-set reference value may be a value previously obtained for a battery in the BOL (Beginning of Life) state. Preferably, the OCV profile Rocv for a battery in the BOL state may show the correspondence between OCV and capacity for the overall capacity range. The control unit 130 can determine the reference value corresponding to the extracted diagnostic factor from the OCV profile Rocv for a battery in the BOL state. That is, the reference value is the state value of the battery in the BOL state, and the diagnostic factor is the state value of the battery in its current state. Therefore, the control unit 130 can estimate the battery's SOH based on the diagnostic factor indicating the battery's current state and the reference value indicating the battery's BOL state.

[0059] An SOH estimation device 100 according to one embodiment of the present invention can estimate the SOH of a battery based on the OCV of the battery measured under predetermined conditions. In other words, according to one embodiment of the present invention, there is an advantage that low-rate charging and discharging is not forced in order to estimate the SOH.

[0060] For example, if a low-rate charge / discharge of 0.05C is required to estimate the SOH, battery use may be limited to approximately 20 hours. In contrast, the SOH estimation device 100 according to one embodiment of the present invention can estimate the battery's SOH simply by securing an OCV profile Rocv that includes multiple OCVs. Furthermore, the conditions under which the OCV is measured are those under which battery use is not forcibly restricted. Therefore, the SOH estimation device 100 can quickly estimate the battery's SOH based on the OCV profile Rocv without restricting battery use, thus solving the conventional problem of excessively restricting battery use in order to estimate the SOH.

[0061] On the other hand, the control unit 130 provided in the SOH estimation device 100 may selectively include processors, ASICs (Application-Specific Integrated Circuits), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the industry, in order to execute the various control logics performed in the present invention. Furthermore, when the control logic is implemented as software, the control unit 130 may be implemented as a collection of program modules. In this case, the program modules may be recorded in memory and executed by the control unit 130. The memory may be provided inside or outside the control unit 130 and may be connected to the control unit 130 by various well-known means.

[0062] Furthermore, the SOH estimation device 100 may further include a recording unit 140. The recording unit 140 may store data and programs necessary for each component of the SOH estimation device 100 to operate and function, or data generated during the process of operation and functioning. The type of recording unit 140 is not particularly limited, as long as it is a known information recording means that is known to be able to record, erase, update, and read data. For example, information recording means may include RAM (Random Access Memory), flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), registers, etc. The recording unit 140 may also store program code in which the process that can be executed by the control unit 130 is defined.

[0063] For example, the recording unit 140 may store the OCV profile Rocv, the reference positive electrode profile Rp, the reference negative electrode profile Rn, the adjusted positive electrode profile, the adjusted negative electrode profile, and diagnostic factors.

[0064] Multiple OCVs may be configured to include multiple OCVs measured within a predetermined reference period.

[0065] Specifically, OCV (Occurrence Computation Value) can have limiting measurement conditions. That is, the time periods over which multiple OCVs are measured may be non-periodic. For example, assume that a car engine is started once a day and the stopping time during operation is less than a baseline. In this case, the OCV is measured only when the car engine is started, so only one OCV may be measured per day. Therefore, the multiple OCVs included in the OCV profile Rocv may be values ​​measured with a time difference throughout the day.

[0066] Given these OCV measurement conditions, a grouping condition is needed for multiple OCVs used to estimate the battery's SOH. That is, if the battery's SOH is estimated using multiple OCVs acquired over an excessively long period, the estimated SOH may not be accurate because the battery may have further degraded during that period. Therefore, the OCV profile Rocv may be configured to include only multiple OCVs measured within a predetermined reference period. Preferably, the reference period can be determined experimentally or theoretically, or by considering the battery's operating pattern (e.g., driving pattern or charge / discharge pattern).

[0067] In one embodiment, the reference period may be set to a predetermined target period. For example, the OCV profile Rocv may include multiple OCVs measured within the last two weeks. Therefore, the State of Health (SOH) estimated based on the OCV profile Rocv, which includes only multiple OCVs measured within the reference period, can accurately reflect the current state of the battery.

[0068] Figure 3 shows the OCV of a battery measured by one embodiment of the present invention.

[0069] For example, in the embodiment shown in Figure 3, the first period (P1) to the fifth period (P5) may be shorter than a preset reference period. Therefore, the SOH estimation device 100 can continuously diagnose the battery's state by estimating the battery's SOH based on the OCV profile Rocv for each of the first period (P1) to the fifth period (P5).

[0070] In other embodiments, the reference period may be set to a period for measuring a predetermined number of OCVs. For example, the number of OCVs measured is proportional to the clarity or accuracy of the OCV profile Rocv. That is, the more OCVs measured, the clearer the OCV profile Rocv becomes, so that the adjustment results of the reference positive electrode profile Rp and reference negative electrode profile Rn better reflect the current state of the battery. Therefore, the reference period may be set to a period until a predetermined number of non-overlapping OCVs (e.g., 30) are measured.

[0071] In yet another embodiment, the reference period may be set to the period it takes for the battery's SOH to decrease by a preset reference SOH. For example, if OCV measurements are performed infrequently, there is a problem that multiple OCVs included in the OCV profile Rocv are measured at different SOHs. In this case, the adjustment results of the reference positive electrode profile Rp and reference negative electrode profile Rn based on the OCV profile Rocv will reflect the battery's past state. Therefore, the reference period may be set to the period until the battery's SOH decreases by a preset reference SOH (e.g., 0.1%).

[0072] In yet another embodiment, the reference period may be set to the shortest of a preset target period, a preset period for measuring a preset number of OCVs, and a preset period for the battery's SOH to decrease by a preset reference SOH.

[0073] While the above describes a limited embodiment of the reference period, it should be noted that the reference period for generating an appropriate OCV profile (Rocv) used to diagnose the current state of the battery can be set considering a variety of factors.

[0074] An SOH estimation device 100 according to one embodiment of the present invention can more accurately estimate the SOH of a battery by limiting the measurement time points of multiple OCVs used for SOH estimation.

[0075] The following describes in detail an embodiment in which the profile correction unit 120 adjusts the reference positive electrode profile Rp and the reference negative electrode profile Rn.

[0076] The profile correction unit 120 may be configured to generate a comparative full cell profile S based on the reference positive electrode profile Rp and the reference negative electrode profile Rn.

[0077] Specifically, a comparative full-cell profile S can be generated according to the voltage difference (specifically, the difference in OCV) corresponding to the capacitance between the reference positive electrode profile Rp and the reference negative electrode profile Rn. For example, suppose the voltage of the reference positive electrode profile Rp corresponding to an arbitrary capacitance X is Vp, and the voltage of the reference negative electrode profile Rn is Vn. The voltage of the comparative full-cell profile S corresponding to capacitance X can be calculated as "Vp-Vn". The profile correction unit 120 can generate the comparative full-cell profile S by calculating the voltage difference between the reference positive electrode profile Rp and the reference negative electrode profile Rn with respect to the total capacitance.

[0078] Figure 4 is a schematic diagram showing a reference positive electrode profile Rp and a reference negative electrode profile Rn according to one embodiment of the present invention, and Figure 5 is a schematic diagram showing a comparative full cell profile S according to one embodiment of the present invention. In the embodiments of Figures 4 and 5, the comparative full cell profile S can be generated based on the voltage difference corresponding to the capacitance between the reference positive electrode profile Rp and the reference negative electrode profile Rn.

[0079] The profile correction unit 120 may be configured to generate an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting the reference positive electrode profile Rp and reference negative electrode profile Rn until the generated comparative full cell profile S corresponds to the OCV profile Rocv.

[0080] Specifically, the profile correction unit 120 can calculate the error between the comparative full cell profile S and the OCV profile Rocv. The profile correction unit 120 can then adjust the reference positive electrode profile Rp and the reference negative electrode profile Rn until the error between the comparative full cell profile S and the OCV profile Rocv is minimized. Once the comparative full cell profile S that minimizes the error with the OCV profile Rocv is determined, the adjusted positive electrode profile and adjusted negative electrode profile that form the basis of the determined comparative full cell profile S can be estimated as the positive electrode profile and negative electrode profile that indicate the current state of the battery. With current technology, there is a problem in that the positive electrode profile and negative electrode profile that indicate the current state of the battery cannot be directly obtained without directly disassembling the battery. Therefore, it can be strongly estimated that the adjusted positive electrode profile and adjusted negative electrode profile that form the basis of the comparative full cell profile S determined through the adjustment process are the positive electrode profile and negative electrode profile that reflect the current state of the battery.

[0081] Figure 6 is a schematic diagram showing a comparative full cell profile S and an OCV profile Rocv according to one embodiment of the present invention. In the embodiment of Figure 6, the profile correction unit 120 can calculate the error between the two profiles based on the voltage difference corresponding to the capacitance between the comparative full cell profile S and the OCV profile Rocv. The profile correction unit 120 can then determine the comparative full cell profile S that minimizes the calculated error.

[0082] Preferably, the profile correction unit 120 may be configured to determine a target capacitance range (T) corresponding to the OCV profile Rocv.

[0083] For example, in the embodiment shown in Figure 6, since the multiple OCVs included in the OCV profile Rocv are measured aperiodically, the correspondence between OCV and capacity may only appear in the target capacity range (T). That is, the target capacity range (T) is the capacity range of the OCV profile Rocv. Therefore, the profile correction unit 120 can first determine the target capacity range (T) based on the OCV profile Rocv. For example, in the embodiment shown in Figure 6, a capacity range of 10 Ah to 45 Ah can be determined as the target capacity range (T).

[0084] The profile correction unit 120 may be configured to compare the comparison full cell profile S and the OCV profile Rocv within the target capacity range (T).

[0085] Specifically, the comparative full-cell profile S is generated based on the reference positive electrode profile Rp and the reference negative electrode profile Rn, and can therefore show the correspondence between voltage and capacitance in the overall capacitance range. In contrast, the OCV profile Rocv shows the correspondence between OCV and capacitance in the target capacitance range (T). Therefore, the profile correction unit 120 can compare the two profiles only in the target capacitance range (T), which is the common capacitance range of the comparative full-cell profile S and the OCV profile Rocv.

[0086] For example, in the embodiment shown in Figure 6, the profile correction unit 120 can compare the comparison full cell profile S and the OCV profile Rocv within the target capacity range (T). The profile correction unit 120 can then further adjust the reference positive electrode profile Rp and the reference negative electrode profile Rn according to the comparison result.

[0087] The following describes in detail the diagnostic factors that the control unit 130 can select from the adjusted positive electrode profile and / or adjusted negative electrode profile.

[0088] The control unit 130 may be configured to extract at least one of the positive electrode factors based on the adjusted positive electrode profile and the negative electrode factors based on the adjusted negative electrode profile as a diagnostic factor.

[0089] Here, the adjusted positive electrode profile is the result of adjusting the reference positive electrode profile Rp, and the adjusted negative electrode profile is the result of adjusting the reference negative electrode profile Rn. Specifically, as described above, the profile correction unit 120 can adjust the reference positive electrode profile Rp and the reference negative electrode profile Rn so that the comparison full cell profile S corresponds to the OCV profile Rocv.

[0090] The positive electrode factor may be configured to include at least one of the battery's positive electrode engagement start point (pi), positive electrode engagement end point (pf), and positive electrode change ratio (ps), based on the adjusted positive electrode profile.

[0091] The positive electrode engagement start point (pi) may be the point in the tuned positive electrode profile that corresponds to the starting capacity (lower limit capacity) of the target capacity range (T). For example, in the embodiment shown in Figure 6, since the starting capacity of the target capacity range (T) is 10 Ah, the point in the tuned positive electrode profile where the capacity value is 10 Ah may be the positive electrode engagement start point (pi). The value of the positive electrode engagement start point (pi) may be the potential value or SOC (State of Charge) value corresponding to the positive electrode engagement start point (pi) in the tuned positive electrode profile.

[0092] The positive electrode termination point (pf) may be the point in the adjusted positive electrode profile that corresponds to the termination capacity (upper capacity) of the target capacity range (T). For example, in the embodiment shown in Figure 6, since the termination capacity of the target capacity range (T) is 45 Ah, the point in the adjusted positive electrode profile where the capacity value is 45 Ah may be the positive electrode termination point (pf). The value of the positive electrode termination point (pf) may be the potential value or SOC value corresponding to the positive electrode termination point (pf) in the adjusted positive electrode profile.

[0093] The positive electrode change ratio (ps) can refer to the percentage change in the modified positive electrode profile relative to the reference positive electrode profile Rp. Specifically, the positive electrode change ratio (ps) can be the contraction or expansion ratio of the modified positive electrode profile relative to the reference positive electrode profile Rp. For example, if the modified positive electrode profile is contracted by 10% from the reference positive electrode profile Rp, the positive electrode change ratio (ps) is 90%. Conversely, if the modified positive electrode profile is expanded by 10% from the reference positive electrode profile Rp, the positive electrode change ratio (ps) is 110%.

[0094] The negative electrode factor may be configured to include at least one of the following: the battery's negative electrode engagement start point (ni), negative electrode engagement end point (nf), and negative electrode change ratio (ns), based on the adjusted negative electrode profile.

[0095] The negative electrode involvement start point (ni) may be the point in the adjusted negative electrode profile that corresponds to the starting capacity (lower limit capacity) of the target capacity range (T). For example, in the embodiment shown in Figure 6, since the starting capacity of the target capacity range (T) is 10 Ah, the point in the adjusted negative electrode profile where the capacity value is 10 Ah may be the negative electrode involvement start point (ni). The value of the negative electrode involvement start point (ni) may be the potential value or SOC value corresponding to the negative electrode involvement start point (ni) in the adjusted negative electrode profile.

[0096] The negative electrode involvement termination point (nf) may be the point in the adjusted negative electrode profile that corresponds to the termination capacity (upper capacity) of the target capacity range (T). For example, in the embodiment shown in Figure 6, since the termination capacity of the target capacity range (T) is 45 Ah, the point in the adjusted negative electrode profile where the capacity value is 45 Ah may be the negative electrode involvement termination point (nf). The value of the negative electrode involvement termination point (nf) may be the potential value or SOC value corresponding to the negative electrode involvement termination point (nf) in the adjusted negative electrode profile.

[0097] The negative electrode change ratio (ns) can refer to the percentage change in the adjusted negative electrode profile relative to the reference negative electrode profile Rn. Specifically, the negative electrode change ratio (ns) can be the contraction or expansion ratio of the adjusted negative electrode profile relative to the reference negative electrode profile Rn. For example, if the adjusted negative electrode profile contracts by 10% from the reference negative electrode profile Rn, the negative electrode change ratio (ns) is 90%. Conversely, if the adjusted negative electrode profile expands by 10% from the reference negative electrode profile Rn, the negative electrode change ratio (ns) is 110%.

[0098] The control unit 130 may be configured to estimate at least one of the battery's positive electrode SOH, negative electrode SOH, available lithium SOH, and capacity SOH depending on the type of diagnostic factor. In the following explanation, the values ​​of the positive electrode involvement start point (pi) and positive electrode involvement end point (pf) refer to the corresponding SOC in the adjusted positive electrode profile, and the values ​​of the negative electrode involvement start point (ni) and negative electrode involvement end point (nf) refer to the corresponding SOC in the adjusted negative electrode profile.

[0099] Positive electrode SOH indicates the degree of degradation of the battery's positive electrode. In other words, positive electrode SOH is an indicator of the extent to which the battery's positive electrode has deteriorated. As the battery deteriorates, the reaction area of ​​the positive electrode decreases due to reasons such as the occurrence of side reactions, which can reduce the positive electrode capacity involved in the reaction. Therefore, the control unit 130 can estimate the degree of degradation due to capacity loss of the positive electrode by calculating positive electrode SOH.

[0100] Specifically, when the control unit 130 extracts the positive electrode involvement termination point (pf) as a diagnostic factor, it can calculate the positive electrode SOH using the following formula 1 or formula 2.

[0101] [Formula 1]

number

[0102] Here, SOH P The positive electrode SOH is pf MOLis the value of the positive electrode involvement end point corresponding to the battery in the current state, pf BOL is the value of the positive electrode involvement end point corresponding to the battery in the BOL state, pi BOL is the value of the positive electrode involvement start point corresponding to the battery in the BOL state. Here, pf BOL , pi BOL , and pf MOL can be the SOC value corresponding to the corresponding point.

[0103] [Formula 2] [Number]

[0104] Here, nf BOL is the value of the negative electrode involvement end point corresponding to the battery in the BOL state, ni BOL is the value of the negative electrode involvement start point corresponding to the battery in the BOL state. Here, ni BOL and nf MOL can be the SOC value corresponding to the corresponding point.

[0105] For example, if pi BOL and pf BOL are set based on the positive electrode capacity in the BOL state, ni BOL and nf BOL can also be set based on the positive electrode capacity in the BOL state. As another example, if pi BOL and pf BOL are set based on the negative electrode capacity in the BOL state, ni BOL and nf BOL can also be set based on the negative electrode capacity in the BOL state. That is, the reference capacity (the positive electrode capacity or the negative electrode capacity in the BOL state) used as the calculation standard for pi<> BOL , pf BOL , ni BOL and nf BOL can be the same. Therefore, referring to Formula 1 and Formula 2, "pf BOL -pi BOL " can be replaced by "nf BOL -ni BOL ".

[0106] Furthermore, if the control unit 130 extracts the positive electrode change ratio (ps) as a diagnostic factor, it can calculate the positive electrode SOH using the following formula 3.

[0107] [Formula 3]

number

[0108] Here, ps BOL This is the positive electrode change ratio corresponding to the battery in the BOL state, and ps MOL This is the positive electrode change ratio corresponding to the current state of the battery. Specifically, ps BOL This represents the ratio of the change in the reference positive electrode profile Rp relative to the initial positive electrode profile. Here, if the initial positive electrode profile and the reference positive electrode profile Rp are the same, ps BOL This can be 1 or 100%. For the sake of explanation, the initial positive electrode profile and the reference positive electrode profile Rp are assumed to be identical. Then, ps MOL This represents the ratio of the change in the adjusted cathode profile relative to the reference cathode profile Rp.

[0109] The negative electrode SOH indicates the degree of degradation of the battery's negative electrode. In other words, the negative electrode SOH is an indicator of the extent to which the battery's negative electrode has deteriorated. Similar to the capacity loss of the positive electrode, as the battery deteriorates, the reaction area of ​​the negative electrode decreases due to reasons such as the occurrence of side reactions, which can reduce the negative electrode capacity involved in the reaction. Therefore, the control unit 130 can estimate the degree of degradation due to capacity loss of the negative electrode by calculating the negative electrode SOH.

[0110] Specifically, if the control unit 130 extracts the negative electrode change ratio (ns) as a diagnostic factor, it can calculate the negative electrode SOH using the following formula 4.

[0111] [Equation 4]

number

[0112] Here, SOH N The negative electrode is SOH, and ns BOL This is the negative electrode change ratio corresponding to the battery in the BOL state, and ns MOL This is the negative electrode change ratio corresponding to the current state of the battery. Specifically, ns BOL This represents the ratio of the change in the reference negative electrode profile Rn relative to the initial negative electrode profile. Here, if the initial negative electrode profile and the reference negative electrode profile Rn are the same, then p nBOL This can be 1 or 100%. For the sake of explanation, the initial negative electrode profile and the reference negative electrode profile Rn are assumed to be identical. Then, ps MOL This represents the ratio of the change in the adjusted negative electrode profile relative to the reference negative electrode profile Rn.

[0113] Available lithium SOH indicates the degree of degradation of the available lithium in the battery. In other words, available lithium SOH is an indicator of the degree of degradation of lithium ions involved in the reaction. When the lithium plating phenomenon occurs, lithium metal may be deposited on the surface of the negative electrode. As the lithium plating phenomenon progresses, the amount of deposited lithium metal increases, and therefore the number of lithium ions involved in the reaction may decrease. Accordingly, the control unit 130 can estimate the degree of degradation of the number of lithium ions involved in the reaction compared to the initial level by calculating the available lithium SOH.

[0114] Specifically, when the control unit 130 extracts the positive electrode involvement start point (pi) as a diagnostic factor, it can calculate the available lithium SOH using the following formula 5 or formula 6.

[0115] [Formula 5]

number

[0116] [Formula 6]

number

[0117] Here, SOH Li This is available lithium SOH. MOL is the value of the positive electrode engagement start point corresponding to the current state of the battery. Here, pi MOL This could be the SOC value corresponding to the relevant point. And, as with equations 1 and 2, referring to equations 5 and 6, "pf BOL -pi BOL " is "nf BOL -ni BOL It can be replaced with ".

[0118] The Capacity SOH indicates the degree of capacity degradation of the battery. In other words, Capacity SOH is an index that shows the degree of degradation of the current usable capacity relative to the battery's initial capacity. As the battery degrades, the usable capacity of the battery may naturally decrease. Therefore, the control unit 130 can estimate the degree of degradation of the current capacity compared to the initial capacity by calculating the Capacity SOH.

[0119] Specifically, when the control unit 130 extracts the positive electrode involvement termination point (pf) and the positive electrode involvement start point (pi) as diagnostic factors, it can calculate the volume SOH using the following formula 7.

[0120] [Equation 7]

number

[0121] Here, SOH Q pf is the volume SOH. BOL pi BOL , pf MOL , and pi MOL As stated above, and "pf BOL -pi BOL " is "nf BOL -ni BOL It can be replaced with ".

[0122] Furthermore, when the control unit 130 extracts the negative electrode involvement termination point (nf) and the negative electrode involvement start point (ni) as diagnostic factors, it can calculate the volume SOH using the following formula 8.

[0123] [Equation 8]

number

[0124] Here, SOH Q This is the capacity SOH. MOL is the value of the negative electrode involvement termination point corresponding to the current state of the battery, and ni MOL This is the value of the negative electrode involvement start point corresponding to the current state of the battery. That is, referring to equations 7 and 8, "pf BOL -pi BOL " is "nf BOL -ni BOL It can be replaced with "pf MOL -pi MOL " is "nf MOL -ni MOL It can be replaced with ".

[0125] As described above, the control unit 130 controls the positive electrode SOH (SOH P ), negative electrode SOH (SOH N ), usable lithium SOH (SOH) Li ), and capacity SOH (SOH Q An embodiment for estimating the following has been described. However, the control unit 130 may calculate the complement of 1 (or 100%) of SOH to estimate the positive electrode degradation rate, negative electrode degradation rate, available lithium degradation rate, and capacity degradation rate. For example, the control unit 130 may calculate "1 - positive electrode SOH" to estimate the positive electrode degradation rate.

[0126] An SOH estimation device 100 according to one embodiment of the present invention can estimate the SOH of a battery from various aspects depending on the extracted diagnostic factors. For example, it can estimate the positive electrode SOH, negative electrode SOH, available lithium SOH, and capacity SOH depending on the extracted diagnostic factors, making it possible to specifically diagnose the degree of degradation for each item of the battery.

[0127] The control unit 130 may be configured to adjust the battery usage conditions based on the estimated SOH.

[0128] Specifically, the control unit 130 can adjust the battery's usable SOC range based on the estimated SOH. For example, the control unit 130 may decrease the upper limit of the battery's usable SOC range. As another example, the control unit 130 may increase the lower limit of the battery's usable SOC range. As yet another example, the control unit 130 may decrease the upper limit of the battery's usable SOC range and increase the lower limit of the usable SOC range.

[0129] By adjusting the available SOC range in this way, it is possible to prevent the loss of reaction area in both the positive and negative electrodes. Furthermore, since the loss of available lithium is prevented, the deposition of lithium metal can be prevented. In addition, the generation of gas inside the battery can be suppressed.

[0130] Hereinafter, with reference to Figures 7 to 14, an embodiment in which the profile correction unit 120 adjusts the reference positive electrode profile Rp and the reference negative electrode profile Rn will be described in more detail.

[0131] Figures 7 to 14 illustrate the process by which the reference positive electrode profile Rp and the reference negative electrode profile Rn are adjusted according to one embodiment of the present invention.

[0132] Figure 7 is a graph used to illustrate an example of a reference positive electrode profile Rp and a reference negative electrode profile Rn. In the graph of Figure 7, the horizontal axis (X axis) represents capacitance (Ah) and the vertical axis (Y axis) represents voltage (V).

[0133] Figure 8 is a graph referenced to illustrate an example of the OCV profile Rocv for the target battery. In the graph in Figure 8, the horizontal axis (X axis) represents capacity (Ah), and the vertical axis (Y axis) represents voltage (V). Referring to Figure 8, we assume that the target capacity range (T) is between 5Ah and 45Ah.

[0134] The profile correction unit 120 may be configured to compare the OCV profile Rocv with at least one comparison full cell profile. Here, the comparison full cell profile may be the result of combining (combining) the adjusted positive electrode profile and the adjusted negative electrode profile based on the reference positive electrode profile Rp and the reference negative electrode profile Rn, respectively, recorded in the recording unit 140.

[0135] In other words, if the reference full cell profile R is the result of subtracting a portion of the reference negative electrode profile Rn from a portion of the reference positive electrode profile Rp, then the comparative full cell profile can be said to be the result of subtracting a portion of the adjusted negative electrode profile from a portion of the adjusted positive electrode profile.

[0136] The profile correction unit 120 can generate at least one comparative full cell profile by directly adjusting the reference positive electrode profile Rp and the reference negative electrode profile Rn. Alternatively, at least one comparative full cell profile can be pre-allocated based on the reference positive electrode profile Rp and the reference negative electrode profile Rn and recorded in the recording unit 140. In this case, the profile correction unit 120 can acquire the comparative full cell profile by accessing the recording unit 140 and reading it.

[0137] The profile correction unit 120 can generate multiple comparison full cell profiles from the reference positive electrode profile Rp and the reference negative electrode profile Rn by repeating an adjustment process in which the reference positive electrode profile Rp and the reference negative electrode profile Rn are each adjusted to many levels and then combined. The comparison full cell profiles may also be referred to as "adjusted reference full cell profiles".

[0138] The profile correction unit 120 can identify one comparison full cell profile from among multiple comparison full cell profiles that minimizes the error with the OCV profile Rocv.

[0139] Subsequently, the profile correction unit 120 may determine that the adjusted positive electrode profile and adjusted negative electrode profile mapped to the identified comparison full cell profile are the positive electrode profile and negative electrode profile of the battery. Note that, below, the positive electrode profile is the finally determined adjusted positive electrode profile, and the negative electrode profile is the finally determined adjusted positive electrode profile.

[0140] In this regard, various methods known at the time of filing of the present invention can be used to determine the error between two profiles that can each be represented in a two-dimensional coordinate system. For example, the integral of the absolute value over the region between the two profiles or the RMSE (Root Mean Square Error) can be used as the error between the two profiles.

[0141] According to this configuration of the present invention, various state information for the battery can be obtained based on the finally determined positive electrode profile and negative electrode profile. The finally determined positive electrode profile and negative electrode profile may be mapped to a comparative full cell profile mapped to the minimum error. In particular, the comparative full cell profile obtained from the finally determined positive electrode profile and negative electrode profile can be said to be in close agreement with the OCV profile Rocv in terms of its general shape and other characteristics.

[0142] Therefore, according to the present invention, the positive electrode profile and negative electrode profile of a battery can be obtained without disassembling the battery.

[0143] If the battery is new, analyzing the positive and negative electrode profiles of the battery makes it easier to diagnose whether or not a defect has occurred in the battery, and if so, what type of defect it is.

[0144] For batteries that have been verified as good quality and are currently in use, the degree of degradation of each degradation item can be determined through the battery's positive and negative electrode profiles.

[0145] Furthermore, according to one embodiment of the present invention, the positive electrode profile and negative electrode profile of the battery can be obtained in a simple manner. The present invention can be realized even if only one reference positive electrode profile Rp and one reference negative electrode profile Rn are recorded in the recording unit 140. In other words, it is not necessary for a large number of reference positive electrode profiles Rp and / or a large number of reference negative electrode profiles Rn to be recorded in the recording unit 140. Therefore, there is no need for a large recording capacity of the recording unit 140, and there is no need to perform many preliminary tests required to secure a large number of reference positive electrode profiles Rp and / or a large number of reference negative electrode profiles Rn.

[0146] Figures 9 to 11 are reference diagrams illustrating an example of the process for generating a comparative full-cell profile used for comparison with the OCV profile Rocv, according to one embodiment of the present invention.

[0147] The comparative full-cell profile generation process, as described with reference to Figures 9 to 11, is performed in the following order: a first routine (see Figure 9) to set four points (positive electrode involvement start point, positive electrode involvement end point, negative electrode involvement start point, and negative electrode involvement end point) corresponding to the voltage range of interest; a second routine (see Figure 10) to perform profile shifting; and a third routine (see Figure 11) to perform capacitance scaling. In other words, the comparative full-cell profile generation process according to one embodiment of the present invention includes the first to third routines.

[0148] First, referring to Figure 9, the reference positive electrode profile Rp and the reference negative electrode profile Rn are the same as those shown in Figure 7.

[0149] The profile correction unit 120 determines the positive electrode involvement start point (pi), positive electrode involvement end point (pf), negative electrode involvement start point (ni), and negative electrode involvement end point (nf) on the reference positive electrode profile Rp and reference negative electrode profile Rn.

[0150] Either the positive electrode involvement start point (pi) or the negative electrode involvement start point (ni) depends on the other.

[0151] As an example, the profile correction unit 120 can divide the positive electrode voltage range from the start point to the end point (or second set voltage) of the reference positive electrode profile Rp into a plurality of minute voltage intervals, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement start point (pi). Each minute voltage interval may have a predetermined size (e.g., 0.01V). Subsequently, the profile correction unit 120 can set a point on the reference negative electrode profile Rn that is smaller than the positive electrode involvement start point (pi) by a first set voltage (e.g., 3V) as the negative electrode involvement start point (ni).

[0152] As another example, the profile correction unit 120 may divide the negative voltage range from the start point to the end point of the reference negative electrode profile Rn into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement start point (ni). Subsequently, the profile correction unit 120 may search for a point in the reference positive electrode profile Rp that is greater than the negative electrode involvement start point (ni) by a first set voltage, and set the searched point as the positive electrode involvement start point (pi).

[0153] Either the positive electrode-involved termination point (pf) or the negative electrode-involved termination point (nf) depends on the other.

[0154] As an example, the profile correction unit 120 may divide the voltage range from the second set voltage to the end point of the reference positive electrode profile Rp into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement termination point (pf). Subsequently, the profile correction unit 120 may set a point on the reference negative electrode profile Rn that is smaller than the positive electrode involvement termination point (pf) by the second set voltage (for example, 4V) as the negative electrode involvement termination point (nf).

[0155] As another example, the profile correction unit 120 may divide the negative voltage range from the start point to the end point of the reference negative electrode profile Rn into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement termination point (nf). Subsequently, the profile correction unit 120 may search for a point in the reference positive electrode profile Rp that is greater than the negative electrode involvement termination point (nf) by a second set voltage, and set the found point as the positive electrode involvement termination point (pf).

[0156] Once the determination of the positive electrode involvement start point (pi), positive electrode involvement end point (pf), negative electrode involvement start point (ni), and negative electrode involvement end point (nf) is complete, the profile correction unit 120 shifts at least one of the reference positive electrode profile Rp and reference negative electrode profile Rn to the left or right along the horizontal axis.

[0157] Referring to Figure 10, the profile correction unit 120 can shift the reference positive electrode profile Rp and / or reference negative electrode profile Rn so that the capacitance value at the positive electrode involvement start point (pi) matches the capacitance value at the negative electrode involvement start point (ni).

[0158] Alternatively, the profile correction unit 120 may shift the reference positive electrode profile Rp and / or reference negative electrode profile Rn so that the voltage at the positive electrode termination point (pf) matches the voltage at the negative electrode termination point (nf).

[0159] Figure 10 illustrates a situation where only the reference positive electrode profile Rp is shifted to the left to generate the adjusted reference positive electrode profile Rp', resulting in the voltage at the positive electrode engagement start point (pi') matching the voltage at the negative electrode engagement start point (ni). The adjusted reference positive electrode profile Rp' is the result of applying an adjustment process to the reference positive electrode profile Rp that shifts it to the left by the voltage difference between the positive electrode engagement start point (pi) and the negative electrode engagement start point (ni). Therefore, the two points (pi, pi') differ only in capacitance value, but have equal voltages. The two points (pf, pf') differ only in capacitance value, but have equal voltages.

[0160] Once an adjusted profile (Rp', Rn) is obtained in which at least one of the reference positive electrode profile Rp and the reference negative electrode profile Rn is shifted, the profile correction unit 120 scales at least one capacitance range of the adjusted profile (Rp', Rn).

[0161] In the example shown in Figure 10, the profile correction unit 120 performs an additional adjustment process to contract or expand at least one of the adjusted reference positive electrode profile Rp' and reference negative electrode profile Rn along the horizontal axis.

[0162] Referring to Figure 11, the profile correction unit 120 can generate an adjusted reference positive electrode profile Rp'' by contracting or expanding the adjusted reference positive electrode profile Rp' so that the size of the capacitance range between two points (pi', pf') in the adjusted reference positive electrode profile Rp' matches the size of the target capacitance range (T) of the OCV profile Rocv. In this case, one of the two points (pi', pf') can be fixed. This ensures that the capacitance difference between the two points (pi', pf) in the adjusted reference positive electrode profile Rp'' matches the target capacitance range (T) of the OCV profile Rocv.

[0163] Furthermore, the profile correction unit 120 can generate an adjusted reference negative electrode profile Rn' by contracting or expanding the reference negative electrode profile Rn so that the size of the capacitance range between two points (ni, nf) in the reference negative electrode profile Rn also matches the size of the target capacitance range (T) of the OCV profile Rocv. In this case, one of the two points (ni, nf) can be fixed. As a result, the capacitance difference between the two points (ni, nf') in the adjusted reference negative electrode profile Rn' will match the target capacitance range (T) of the OCV profile Rocv.

[0164] In Figure 11, the adjusted reference positive electrode profile Rp'' is the result of contracting the adjusted reference positive electrode profile Rp' shown in Figure 8, and the adjusted reference negative electrode profile Rn' is the result of expanding the reference negative electrode profile Rn shown in Figure 10.

[0165] The positive electrode involvement endpoint (pf) on the adjusted reference positive electrode profile Rp'' corresponds to the positive electrode involvement endpoint (pf) on the adjusted reference positive electrode profile Rp'. The negative electrode involvement endpoint (nf') on the adjusted reference negative electrode profile Rn' corresponds to the negative electrode involvement endpoint (nf) on the reference negative electrode profile Rn.

[0166] The volume difference between the positive electrode involvement start point (pi') and the positive electrode involvement end point (pf) of the adjusted reference positive electrode profile Rp'' corresponds to the size of the target volume range (T) of the OCV profile Rocv. Similarly, the volume difference between the negative electrode involvement start point (ni) and the negative electrode involvement end point (nf') of the adjusted reference negative electrode profile Rn' corresponds to the size of the target volume range (T) of the OCV profile Rocv.

[0167] Furthermore, the capacitance range between two points (pi', pf') of the adjusted reference positive electrode profile Rp'' matches the capacitance range between two points (ni, nf') of the adjusted reference negative electrode profile Rn'. The profile correction unit 120 can generate a comparative full cell profile S by subtracting the profile between two points (pi, pf') of the adjusted reference positive electrode profile Rp'' from the profile between two points (ni, nf') of the adjusted reference negative electrode profile Rn'.

[0168] The profile correction unit 120 can calculate the error (profile error) between the comparison full cell profile S and the OCV profile Rocv. If the error between the comparison full cell profile S and the OCV profile Rocv is minimized, the adjusted reference positive electrode profile Rp'' corresponding to the comparison full cell profile S can be determined as the adjusted positive electrode profile, and the adjusted reference negative electrode profile Rn' can be determined as the adjusted negative electrode profile.

[0169] The profile correction unit 120 can map at least two of the following to each other and record them in the recording unit 140: the adjusted reference positive electrode profile Rp'', the adjusted reference negative electrode profile Rn', the positive electrode involvement start point (pi'), the positive electrode involvement end point (pf''), the negative electrode involvement start point (ni), the negative electrode involvement end point (nf'), the first scale factor, the second scale factor, the comparison full cell profile S, and the profile error. The first scale factor may represent the ratio of the capacitance difference between two points (pi', pf'') to the capacitance difference between two points (pi0, pf0). The second scale factor may represent the ratio of the capacitance difference between two points (ni, nf') to the capacitance difference between two points (ni0, nf0).

[0170] Here, the profile correction unit 120 can calculate the positive electrode change ratio (ps) of the adjusted reference positive electrode profile Rp'' with respect to the reference positive electrode profile Rp. The profile correction unit 120 can also calculate the negative electrode change ratio (ns) of the adjusted reference negative electrode profile Rn' with respect to the reference negative electrode profile Rn. For example, the profile correction unit 120 can determine the first scale factor as the positive electrode change ratio (ps) and the second scale factor as the negative electrode change ratio (ns).

[0171] On the other hand, as described above, when the positive electrode voltage range of the reference positive electrode profile Rp is divided into multiple minute voltage intervals, the boundary point between two adjacent minute voltage intervals can be set as the positive electrode involvement start point (pi).

[0172] For example, if the positive electrode voltage range of the reference positive electrode profile Rp is divided into 100 minute voltage ranges, there may be 100 boundary points that can be set as the positive electrode involvement start point (pi). Also, if the voltage range above the second set voltage in the reference positive electrode profile Rp is divided into 40 minute voltage ranges, there may be 40 boundary points that can be set as the positive electrode involvement end point (pf). In this case, up to 4000 different comparison full cell profiles can be generated.

[0173] Of course, it is easily understood by those skilled in the art that the number of comparative full-cell profiles that can be generated increases as the size of the minute voltage interval decreases, and conversely, the number of comparative full-cell profiles that can be generated decreases as the size of the minute voltage interval increases.

[0174] The profile correction unit 120 identifies the minimum value from among the multiple comparison full cell profiles generated as described above, and then may obtain information mapped to the minimum profile error (for example, at least one of the following: positive electrode involvement start point (pi), positive electrode involvement end point (pf), negative electrode involvement start point (ni), negative electrode involvement end point (nf), positive electrode change ratio (ps), negative electrode change ratio (ns)) from the recording unit 140.

[0175] Figures 12-14 are reference diagrams illustrating another example of the process for generating a comparative full-cell profile used for comparison with the OCV profile Rocv according to one embodiment of the present invention. For reference, the embodiments in Figures 12-14 are independent of the embodiments in Figures 9-11. Therefore, terms and reference numerals used in common in the descriptions of the embodiments in Figures 9-11 and Figures 12-14 should be understood as being limited to each respective embodiment.

[0176] The comparative full-cell profile generation process, as described with reference to Figures 12 to 14, is performed in the following order: a fourth routine for capacity scaling (see Figure 12), a fifth routine for setting four points (positive electrode involvement start point, positive electrode involvement end point, negative electrode involvement start point, negative electrode involvement end point) (see Figure 13), and a sixth routine for profile shifting (see Figure 14). That is, the comparative full-cell profile generation process according to other embodiments of the present invention includes the fourth to sixth routines.

[0177] Referring to Figure 12, the reference positive electrode profile Rp and the reference negative electrode profile Rn are the same as those shown in Figure 7.

[0178] The profile correction unit 120 applies a first scale factor and a second scale factor selected from the scaling numerical range to the reference positive electrode profile Rp and the reference negative electrode profile Rn, respectively, to generate an adjusted reference positive electrode profile Rp' and an adjusted reference negative electrode profile Rn'.

[0179] The scaling numerical range is either predetermined or can vary depending on the ratio of the size of the target capacity range (T) of the OCV profile Rocv to the size of the capacity range of the reference full-cell profile R. For example, if the first and second scale factors can be selected from values ​​spaced 0.1% apart within the scaling numerical range (e.g., 90% to 99%) (i.e., 90%, 90.1%, 90.2%, ..., 98.9%, 99%), then 91 values ​​can be selected as the first and second scale factors, respectively. In this case, 91 × 91 = 8,281 adjustment levels (combinations of the first and second scale factors) can generate up to 8,281 adjusted profile pairs. An adjusted profile pair means a combination of an adjusted reference positive electrode profile and an adjusted reference negative electrode profile.

[0180] The adjusted reference positive electrode profile Rp' and adjusted reference negative electrode profile Rn' shown in Figure 12 illustrate the results of applying a first scale factor and a second scale factor of less than 100%, respectively, to the reference positive electrode profile Rp and the reference negative electrode profile Rn.

[0181] Since the first and second scale factors are less than 100%, the adjusted reference positive electrode profile Rp' is the reference positive electrode profile Rp contracted along the horizontal axis, and the adjusted reference negative electrode profile Rn' is the reference negative electrode profile Rn contracted along the horizontal axis. For ease of understanding, the starting points of the reference positive electrode profile Rp and the reference negative electrode profile Rn are fixed, and only the remaining parts are shown as a schematic representation contracted to the left along the horizontal axis.

[0182] Referring to Figure 13, the profile correction unit 120 determines the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement end point (nf') on the adjusted reference positive electrode profile Rp' and the adjusted reference negative electrode profile Rn'.

[0183] Either the positive electrode involvement start point (pi') or the negative electrode involvement start point (ni') may depend on the other. Similarly, either the positive electrode involvement end point (pf') or the negative electrode involvement end point (nf') may depend on the other. Furthermore, either the positive electrode involvement start point (pi') or the positive electrode involvement end point (pf') may be set based on the other.

[0184] In other words, if any one of the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement 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 size of the target capacitance range (T) of the OCV profile Rocv (e.g., the charging capacity of capacitance values ​​from 0 to 100%).

[0185] As an example, the profile correction unit 120 may divide the positive electrode voltage range from the start point to the end point (or second set voltage) of the adjusted reference positive electrode profile Rp' into a plurality of minute voltage intervals, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement start point (pi'). Subsequently, the profile correction unit 120 may set a point on the adjusted reference negative electrode profile Rn that is smaller than the positive electrode involvement start point (pi') by a first set voltage (e.g., 3V) as the negative electrode involvement start point (ni').

[0186] As another example, the profile correction unit 120 may divide the negative voltage range from the start point to the end point of the adjusted reference negative electrode profile Rn' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement start point (ni'). Subsequently, the profile correction unit 120 may search for a point in the reference positive electrode profile Rp that is greater than the negative electrode involvement start point (ni') by a first set voltage, and set the found point as the positive electrode involvement start point (pi').

[0187] As yet another example, the profile correction unit 120 may divide the voltage range from the second set voltage to the end point of the adjusted reference positive electrode profile Rp' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the positive electrode involvement termination point (pf'). Subsequently, the profile correction unit 120 may search for a point in the adjusted reference negative electrode profile Rn' that is smaller than the positive electrode involvement termination point (pf') by the second set voltage (e.g., 4V), and set the found point as the negative electrode involvement termination point (nf').

[0188] As yet another example, the profile correction unit 120 may divide the negative voltage range from the start point to the end point of the adjusted reference negative electrode profile Rn' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point between two adjacent minute voltage intervals as the negative electrode involvement termination point (nf'). Subsequently, the profile correction unit 120 may search for a point in the adjusted reference positive electrode profile Rp' that is greater than the negative electrode involvement termination point (nf') by a second set voltage, and set the found point as the positive electrode involvement termination point (pf').

[0189] The profile correction unit 120 can determine the remaining three points based on the determined point once one of the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement end point (nf') has been determined.

[0190] As an example, once the positive electrode involvement start point (pi') is determined, the profile correction unit 120 may set a point on the adjusted reference positive electrode profile Rp' having a capacitance value that is larger than the capacitance value of the positive electrode involvement start point (pi') by the size of the target capacitance range (T) of the OCV profile Rocv as the positive electrode involvement end point (pf'). Alternatively, the profile correction unit 120 may search for a point on the adjusted reference negative electrode profile Rn' that is lower than the positive electrode involvement start point (pi') by a first set voltage, and set the found point as the negative electrode involvement start point (ni'). Furthermore, the profile correction unit 120 may set a point on the adjusted reference negative electrode profile Rn' having a capacitance value that is larger than the capacitance value of the negative electrode involvement start point (ni') by the size of the target capacitance range (T) of the OCV profile Rocv as the negative electrode involvement end point (nf').

[0191] As another example, once the positive electrode involvement termination point (pf') is determined, the profile correction unit 120 may set a point on the adjusted reference positive electrode profile Rp' having a capacitance value smaller by the size of the target capacitance range (T) of the OCV profile Rocv than the capacitance value of the positive electrode involvement termination point (pf') as the positive electrode involvement start point (pi'). Alternatively, the profile correction unit 120 may search for a point on the adjusted reference negative electrode profile Rn' that is lower by a second set voltage than the positive electrode involvement termination point (pf') and set the found point as the negative electrode involvement termination point (nf'). Furthermore, the profile correction unit 120 may set a point on the adjusted reference negative electrode profile Rn' having a capacitance value smaller by the size of the target capacitance range (T) of the OCV profile Rocv than the capacitance value of the negative electrode involvement termination point (nf') as the negative electrode involvement start point (ni').

[0192] As yet another example, once the negative electrode involvement start point (ni') is determined, the profile correction unit 120 may set a point on the adjusted reference negative electrode profile Rn' having a capacitance value that is larger than the capacitance value of the negative electrode involvement start point (ni') by the size of the target capacitance range (T) of the OCV profile Rocv as the negative electrode involvement end point (nf'). Alternatively, the profile correction unit 120 may search for a point on the adjusted reference positive electrode profile Rp' that is higher than the negative electrode involvement start point (ni') by the first set voltage, and set the found point as the positive electrode involvement start point (pi'). Furthermore, the profile correction unit 120 may set a point on the adjusted reference positive electrode profile Rp' having a capacitance value that is larger than the capacitance value of the positive electrode involvement start point (pi') by the size of the target capacitance range (T) of the OCV profile Rocv as the positive electrode involvement end point (pf').

[0193] As yet another example, once the negative electrode involvement termination point (nf') is determined, the profile correction unit 120 may set a point on the adjusted reference negative electrode profile Rn' having a capacitance value smaller by the size of the target capacitance range (T) of the OCV profile Rocv than the capacitance value of the negative electrode involvement termination point (nf') as the negative electrode involvement start point (ni'). Alternatively, the profile correction unit 120 may search for a point on the adjusted reference positive electrode profile Rp' that is higher by a second set voltage than the negative electrode involvement termination point (nf') and set the found point as the positive electrode involvement termination point (pf'). Furthermore, the profile correction unit 120 may set a point on the adjusted reference positive electrode profile Rp' having a capacitance value smaller by the size of the target capacitance range (T) of the OCV profile Rocv than the capacitance value of the positive electrode involvement termination point (pf') as the positive electrode involvement start point (pi').

[0194] Once the determination of the positive electrode involvement start point (pi'), positive electrode involvement end point (pf'), negative electrode involvement start point (ni'), and negative electrode involvement end point (nf') is complete based on the pair of the first scale factor and the second scale factor, the profile correction unit 120 may shift at least one of the adjusted reference positive electrode profile Rp' and adjusted reference negative electrode profile Rn' along the horizontal axis so that the capacity value of the positive electrode involvement start point (pi') matches the capacity value of the negative electrode involvement start point (ni'), or so that the capacity value of the positive electrode involvement end point (pf') matches the capacity value of the negative electrode involvement end point (nf').

[0195] The adjusted reference negative electrode profile Rn'' shown in Figure 14 is obtained by shifting only the adjusted reference negative electrode profile Rn' shown in Figure 13 to the right. As a result, the capacitance value at the positive electrode engagement start point (pi') matches the capacitance value at the negative electrode engagement start point (ni''). In relation to this, since the capacitance difference between the positive electrode engagement start point (pi') and the positive electrode engagement end point (pf') is equal to the capacitance difference between the negative electrode engagement start point (ni') and the negative electrode engagement end point (nf'), if the capacitance value at the positive electrode engagement start point (pi') matches the capacitance value at the negative electrode engagement start point (ni''), then the capacitance value at the positive electrode engagement end point (pf') will also match the capacitance value at the negative electrode engagement end point (nf'').

[0196] Referring to Figure 14, the profile correction unit 120 can generate a comparative full cell profile U by subtracting the partial profile between two points (pi', pf') of the adjusted reference positive electrode profile Rp' from the partial profile between two points (ni'', nf'') of the adjusted reference negative electrode profile Rn''.

[0197] The profile correction unit 120 can calculate the error (profile error) between the comparison full cell profile U and the OCV profile Rocv. If the error between the comparison full cell profile U and the OCV profile Rocv is minimized, the adjusted reference positive electrode profile Rp' corresponding to the comparison full cell profile U can be determined as the adjusted positive electrode profile, and the adjusted reference negative electrode profile Rn'' can be determined as the adjusted negative electrode profile.

[0198] The profile correction unit 120 can map at least two of the following to each other and record them in the recording unit 140: the adjusted reference positive electrode profile Rp', the adjusted reference negative electrode profile Rn'', the positive electrode involvement start point (pi'), the positive electrode involvement end point (pf'), the negative electrode involvement start point (ni"), the negative electrode involvement end point (nf"), the positive electrode change ratio (ps), the negative electrode change ratio (ns), the comparison full cell profile U, and the profile error.

[0199] Here, the profile correction unit 120 can calculate the positive electrode change ratio (ps) of the adjusted reference positive electrode profile Rp' with respect to the reference positive electrode profile Rp. The profile correction unit 120 can also calculate the negative electrode change ratio (ns) of the adjusted reference positive electrode profile Rn'' with respect to the reference negative electrode profile Rn. For example, the profile correction unit 120 can determine the first scale factor as the positive electrode change ratio (ps) and the second scale factor as the negative electrode change ratio (ns).

[0200] As described above, the profile correction unit 120 can generate a corresponding comparison full cell profile for each pair of first and second scale factors selected from the scaling numerical range. Since there are multiple pairs of first and second scale factors, it is obvious that multiple comparison full cell profiles will also be generated. After identifying the minimum value from among the profile errors of the multiple comparison full cell profiles, the profile correction unit 120 can obtain information mapped to the minimum profile error from the recording unit 140.

[0201] An SOH estimation device 100 according to one embodiment of the present invention is connected to a display device (not shown) and can output information about the battery's SOH. As a result, information about the battery's SOH can be displayed on the display device.

[0202] An SOH estimation device 100 according to one embodiment of the present invention can be connected to an alarm device (not shown) and output information about the battery's SOH to activate the alarm device.

[0203] An SOH estimation device 100 according to one embodiment of the present invention may be applied to a battery management system (BMS). That is, the BMS according to the present invention may include the above-described SOH estimation device 100. In such a configuration, at least some of the components of the SOH estimation device 100 may be implemented by complementing or adding to the functions of components included in a conventional BMS. For example, the profile acquisition unit 110, profile correction unit 120, control unit 130, and recording unit 140 of the SOH estimation device 100 may be implemented as components of a BMS.

[0204] Furthermore, the SOH estimation device 100 according to one embodiment of the present invention may be provided in a battery pack. That is, the battery pack according to the present invention may include the above-described SOH estimation device 100 and one or more battery cells. The battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0205] Figure 15 shows an exemplary configuration of a battery pack 1 according to another embodiment of the present invention.

[0206] The positive terminal of battery 10 may be connected to the positive terminal P+ of battery pack 1, and the negative terminal of battery 10 may be connected to the negative terminal P- of battery pack 1.

[0207] The measuring unit 20 can be connected to the positive and negative terminals of the battery 10. The measuring unit 20 can also measure the positive and negative potentials of the battery 10 and calculate the voltage of the battery 10 by calculating the difference between the positive and negative potentials. Preferably, the measuring unit 20 can measure the OCV of the battery 10.

[0208] Furthermore, the measurement unit 20 can be connected to the current measurement unit A. For example, the current measurement unit A may be an ammeter or shunt resistor capable of measuring the charging current and discharging current of the battery 10. The measurement unit 20 can measure the charging current of the battery 10 using the current measurement unit A and calculate the charge amount. The measurement unit 20 can also measure the discharging current of the battery 10 through the third sensing line SL3 and calculate the discharge amount.

[0209] For example, information about the voltage and capacity of the battery 10 measured by the measurement unit 20 can be transmitted to the profile acquisition unit 110. The profile acquisition unit 110 can then directly generate an OCV profile Rocv based on the received voltage and capacity information.

[0210] As another example, information about the voltage and capacity of the battery 10 measured by the measurement unit 20 can be recorded in the recording unit 140. Once the charging or discharging of the battery 10 is complete, the profile acquisition unit 110 can access the recording unit 140 to acquire the OCV profile Rocv.

[0211] As yet another example, the measurement unit 20 may directly generate an OCV profile Rocv based on the measured information about the voltage and capacity of the battery 10. In this case, the generated OCV profile Rocv is transmitted to the profile acquisition unit 110 and can also be recorded in the recording unit 140.

[0212] A charge / discharge device or load can be connected to the positive terminal P+ and negative terminal P- of the battery pack 1.

[0213] Figure 16 is a diagram illustrating an exemplary configuration of an automobile according to yet another embodiment of the present invention.

[0214] Referring to Figure 16, the battery pack 1610 according to an embodiment of the present invention can be installed in an automobile 1600 such as an electric vehicle (EV) or a hybrid vehicle (HV). The battery pack 1610 can drive the automobile 1600 by supplying power to the motor through an inverter provided in the automobile 1600. Here, the battery pack 1610 may include a State of Health (SOH) estimation device 100. That is, the automobile 1600 may include a State of Health (SOH) estimation device 100.

[0215] In this case, the SOH estimation device 100 may be an onboard diagnostic device included in the automobile 1600. That is, the SOH estimation device 100 can estimate the battery's SOH from various aspects based on the OCV profile of the battery installed in the automobile 1600. The SOH estimation device 100 can then provide the user with information about the estimated SOH.

[0216] A server according to yet another embodiment of the present invention may include a SOH estimation device 100. For example, the server may receive an OCV profile Rocv from a BMS connected to the battery. In another example, the server may receive information about the battery capacity and OCV from the BMS and directly generate an OCV profile Rocv based on the received information.

[0217] The server can generate a modified positive electrode profile and a modified negative electrode profile by adjusting the reference positive electrode profile Rp and reference negative electrode profile Rn to correspond to the OCV profile Rocv. The server can then extract diagnostic factors from the modified positive electrode profile and / or modified negative electrode profile and estimate the battery's State of Health (SOH) based on the extracted diagnostic factors. The server can then provide battery status information by transmitting information about the estimated SOH to the BMS.

[0218] Figure 17 is a schematic diagram illustrating a method for estimating SOH according to yet another embodiment of the present invention.

[0219] Referring to Figure 17, the SOH estimation method includes a profile acquisition step S100, a profile adjustment step S200, a diagnostic factor extraction step S300, and an SOH estimation step S400.

[0220] Preferably, each step of the SOH estimation method can be performed by the SOH estimation device 100. For the sake of clarity, the following will either omit or briefly explain any content that overlaps with the above.

[0221] The profile acquisition step S100 is a step of acquiring an OCV profile Rocv showing multiple OCVs of a battery measured at different points in time, which may be performed by the profile acquisition unit 110.

[0222] For example, the profile acquisition unit 110 can directly receive the OCV profile Rocv from an external source. That is, the profile acquisition unit 110 can acquire the OCV profile Rocv by receiving it via a wired and / or wireless connection to an external source.

[0223] As another example, the profile acquisition unit 110 can receive battery information regarding the battery's OCV and capacity. The profile acquisition unit 110 can then generate an OCV profile Rocv based on the received battery information. In other words, the profile acquisition unit 110 can acquire an OCV profile Rocv by directly generating the OCV profile Rocv based on the battery information.

[0224] The profile adjustment step S200 is a step of adjusting a preset reference positive electrode profile and a reference negative electrode profile to correspond to the OCV profile Rocv, in order to generate an adjusted positive electrode profile and an adjusted negative electrode profile, which may be performed by the profile correction unit 120.

[0225] For example, the profile correction unit 120 can generate multiple comparison full cell profiles by shifting or capacitance scaling the reference positive electrode profile and the reference negative electrode profile, and can identify the comparison full cell profile from among the multiple comparison full cell profiles that minimizes the error with the OCV profile Rocv. Then, the adjusted positive electrode profile and adjusted negative electrode profile corresponding to the identified comparison full cell profile can be determined.

[0226] The diagnostic factor extraction step S300 is a step of extracting a diagnostic factor of the battery from at least one of the regulated positive electrode profile and the regulated negative electrode profile, and can be performed by the control unit 130.

[0227] Specifically, the control unit 130 can extract diagnostic factors related to the positive electrode from the adjusted positive electrode profile. Furthermore, the control unit 130 can extract diagnostic factors related to the negative electrode from the adjusted negative electrode profile.

[0228] For example, the positive electrode factor may include at least one of the values ​​for the battery's positive electrode engagement start point (pi) and positive electrode engagement end point (pf) based on the tuned positive electrode profile. The negative electrode factor may include at least one of the values ​​for the battery's negative electrode engagement start point (ni), negative electrode engagement end point (nf), and negative electrode change ratio (ns) based on the tuned negative electrode profile.

[0229] The SOH estimation step S400 is a step of estimating the SOH of the battery based on the extracted diagnostic factors, and can be performed by the control unit 130.

[0230] Specifically, the control unit 130 can estimate the battery's State of Health (SOH) by comparing a preset reference value for a diagnostic factor with the value of the diagnostic factor. For example, the control unit 130 can estimate at least one of the following: the positive electrode SOH, negative electrode SOH, available lithium SOH, and capacity SOH of the battery, depending on the type of diagnostic factor.

[0231] For example, the control unit 130 refers to at least one of the above formulas 1 to 3 to determine the positive electrode SOH(SOH P ) can be estimated. Then, the control unit 130 refers to the above formula 4 and estimates the negative electrode SOH (SOH N ) can be estimated. Then, the control unit 130 refers to the above formula 5 or formula 6 to estimate the available lithium SOH (SOH). Li ) can be estimated. Finally, the control unit 130 can estimate the capacity SOH (SOH) by referring to the above formula 7 or formula 8. Q ) can be estimated.

[0232] The embodiments of the present invention described above are not limited to apparatus and methods, but can also be implemented through a program that realizes the functions corresponding to the configuration of the embodiments of the present invention, or through a recording medium on which such program is recorded. The program or recording medium can be easily implemented by those skilled in the art based on the description of the embodiments described above.

[0233] As described above, the present invention has been explained with limited embodiments and drawings, but it goes without saying that the present invention is not limited thereto, and that various modifications and variations are possible within the equivalent scope of the technical idea and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains.

[0234] Furthermore, the present invention described above can be substituted, modified, and altered in various ways by a person with ordinary skill in the art to which the present invention pertains, without departing from the technical spirit of the invention, and is not limited by the embodiments described above and the accompanying drawings. For diverse modifications, all or part of each embodiment may be selectively combined to form the present invention. [Explanation of Symbols]

[0235] 1: Battery pack 10: Battery 20: Measuring part 100:SOH estimation device 110: Profile acquisition unit 120: Profile Correction Section 130: Control Unit 140: Records Department 1600: Automobile 1610: Battery Pack

Claims

1. A profile acquisition unit is configured to acquire OCV profiles showing multiple OCVs of a battery measured at different points in time, A profile correction unit is configured to generate an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting a preset reference positive electrode profile and a reference negative electrode profile to correspond to the OCV profile. An SOH estimation device comprising: a control unit configured to extract diagnostic factors of the battery from at least one of the adjusted positive electrode profile and the adjusted negative electrode profile, and to estimate the SOH of the battery based on the extracted diagnostic factors.

2. The SOH estimation device according to claim 1, wherein the plurality of OCVs are configured to include an OCV measured at the time the battery switches from a resting state to a discharge state, and an OCV measured while the state in which the discharge current of the battery is below a preset threshold current is maintained for a preset reference time or longer.

3. The SOH estimation device according to claim 2, wherein the plurality of OCVs are configured to include a plurality of OCVs measured within a predetermined reference period.

4. The SOH estimation device according to claim 3, wherein the reference period is set to a preset target period, a period required to measure a preset number of OCVs, a period required for the SOH of the battery to decrease by a preset reference SOH, or a period based on a combination thereof.

5. The SOH estimation apparatus according to claim 1, wherein the profile correction unit is configured to generate a comparative full cell profile based on the reference positive electrode profile and the reference negative electrode profile, and to adjust the reference positive electrode profile and the reference negative electrode profile until the generated comparative full cell profile corresponds to the OCV profile, thereby generating the adjusted positive electrode profile and the adjusted negative electrode profile.

6. The SOH estimation apparatus according to claim 5, wherein the profile correction unit is configured to determine a target capacity range corresponding to the OCV profile and to compare the comparison full cell profile with the OCV profile within the target capacity range.

7. The SOH estimation device according to claim 1, wherein the control unit is configured to estimate the SOH of the battery by comparing a preset reference value for the diagnostic factor with the value of the diagnostic factor.

8. The SOH estimation device according to claim 7, wherein the control unit is configured to estimate at least one of the positive electrode SOH, negative electrode SOH, available lithium SOH, and capacity SOH of the battery according to the type of diagnostic factor.

9. The SOH estimation device according to claim 1, wherein the control unit is configured to extract at least one of the positive electrode factors based on the adjusted positive electrode profile and the negative electrode factors based on the adjusted negative electrode profile as the diagnostic factor.

10. The positive electrode factor is configured to include at least one of the positive electrode engagement start point, positive electrode engagement end point, and positive electrode change ratio of the battery based on the adjusted positive electrode profile. The SOH estimation device according to claim 9, wherein the negative electrode factor is configured to include at least one of the negative electrode involvement start point, negative electrode involvement end point, and negative electrode change ratio of the battery based on the adjusted negative electrode profile.

11. The SOH estimation device according to claim 1, wherein the control unit is configured to adjust the battery usage conditions based on the estimated SOH.

12. A battery pack comprising the SOH estimation device according to any one of claims 1 to 11.

13. An automobile comprising the SOH estimation device according to any one of claims 1 to 11.

14. A server comprising the SOH estimation device according to any one of claims 1 to 11.

15. A profiling step to obtain an OCV profile showing multiple OCVs of the battery measured at different points in time, A profile adjustment step involves adjusting a pre-set reference positive electrode profile and reference negative electrode profile to correspond to the OCV profile, thereby generating an adjusted positive electrode profile and an adjusted negative electrode profile. A diagnostic factor extraction step of extracting a diagnostic factor of the battery from at least one of the adjusted positive electrode profile and the adjusted negative electrode profile, A method for estimating the state of health (SOH) of a battery, comprising: an SOH estimation step of estimating the SOH of the battery based on extracted diagnostic factors.

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