Apparatus and method for diagnosing battery

Abstract

An apparatus for diagnosing a battery, according to one embodiment of the present invention, comprises: a profile acquisition unit for obtaining a battery profile that indicates a correspondence relationship between the voltage and the capacity of a battery; a profile adjustment unit for adjusting, in correspondence to the battery profile, a preset first reference profile and a preset second reference profile, and generating a first profile according to the adjustment result; and a control unit for diagnosing the state of the battery on the basis of a first feature value for a first feature point included in the first profile.

Description

Battery diagnostic device and method

[0001] This application claims priority to Korean Patent Application No. 10-2024-0006174, filed on January 15, 2024, the entire contents of which are disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0002] The present invention relates to a battery diagnostic device and method, and more particularly, to a battery diagnostic device and method for diagnosing the state of a battery.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.

[0004] Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based batteries.

[0005] While extensive research is being conducted on these batteries to improve capacity and density, improving lifespan and safety is also crucial. To improve battery safety, technology is required to accurately diagnose the current battery condition.

[0006] In particular, it is necessary to prevent lithium plating, a phenomenon in which lithium is deposited on the surface of the anode. Lithium plating on the surface of the anode can cause side reactions with the electrolyte and alter the kinetic balance of the battery, leading to battery degradation. Furthermore, the deposition of lithium metal on the surface of the anode can cause internal short circuits in the battery, posing a risk of fire or explosion due to internal short circuits. Therefore, the development of a technology capable of detecting the deposition of lithium metal on the surface of the anode is necessary.

[0007] The present invention has been devised to solve the above problems, and its purpose is to provide a battery diagnosis device and method for diagnosing the state of a battery in a non-destructive manner.

[0008] Other objects and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0009] A battery diagnosis device according to one aspect of the present invention may include a profile acquisition unit configured to acquire a battery profile indicating a correspondence between a voltage and a capacity of a battery; a profile adjustment unit configured to adjust a preset first reference profile and a second reference profile to correspond to the battery profile and generate a first profile according to the adjustment result; and a control unit configured to diagnose a state of the battery based on a first characteristic value for a first characteristic point included in the first profile.

[0010] The control unit may be configured to diagnose the state of the battery as a normal state or a state of available lithium loss.

[0011] The control unit may be configured to diagnose the state of the battery as the available lithium loss state when the first characteristic value exceeds a preset first reference value.

[0012] The control unit may be configured to diagnose the state of the battery as the normal state if the first characteristic value is less than or equal to the first reference value.

[0013] The control unit may be configured to calculate an available lithium loss rate based on preset first reference values ​​and second reference values ​​and the first characteristic value, compare the calculated available lithium loss rate with the preset second reference value, and diagnose the state of the battery based on the comparison result.

[0014] The control unit may be configured to diagnose the state of the battery as the available lithium loss state when the available lithium loss rate exceeds the second reference value.

[0015] The control unit may be configured to diagnose the state of the battery as the normal state if the available lithium loss rate is less than or equal to the second reference value.

[0016] The above first reference value may be preset as the SOC of the first reference point included in the first reference profile.

[0017] The second reference value may be preset as the SOC of the second reference point included in the first reference profile.

[0018] The above first feature value may be the SOC of the first feature point included in the first profile.

[0019] A battery pack according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0020] A vehicle according to another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0021] A battery diagnosis method according to another aspect of the present invention may include a profile acquisition step of acquiring a battery profile indicating a correspondence between a voltage and a capacity of a battery; a profile adjustment step of adjusting a preset first reference profile and a second reference profile to correspond to the battery profile and generating a first profile according to the adjustment result; and a battery diagnosis step of diagnosing the state of the battery based on a first characteristic value of a first characteristic point included in the first profile.

[0022] According to one aspect of the present invention, since the degradation pattern of the battery can be specifically diagnosed, the current state of the battery can be qualitatively diagnosed in a non-destructive manner.

[0023] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0024] The following drawings attached to this specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to the matters described in such drawings.

[0025] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.

[0026] FIG. 2 is a diagram schematically illustrating the results of adjusting a first reference profile and a second reference profile according to one embodiment of the present invention.

[0027] Figure 3 is a graph referenced to explain an example of each of the first reference profile and the second reference profile.

[0028] Figure 4 is a graph referenced to explain an example of a battery profile of a target cell.

[0029] FIGS. 5 to 7 are drawings for reference in explaining an example of a procedure for generating a comparison profile used for comparison with a battery profile according to one embodiment of the present invention.

[0030] FIGS. 8 to 10 are drawings for reference in explaining another example of a procedure for generating a comparison profile used for comparison with a battery profile according to one embodiment of the present invention.

[0031] Figure 11 is a drawing referenced to explain the difference between the first battery and the second battery.

[0032] FIG. 12 is a drawing illustrating an exemplary configuration of a battery pack including a battery diagnostic device according to one embodiment of the present invention.

[0033] FIG. 13 is a schematic drawing of a vehicle according to another embodiment of the present invention.

[0034] FIG. 14 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.

[0035] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.

[0036] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0037] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0038] Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

[0039] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0040] Additionally, throughout the specification, when we say that a part is "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

[0041]

[0042] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0043] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.

[0044] Referring to FIG. 1, the battery diagnostic device (100) may include a profile acquisition unit (110), a profile adjustment unit (120), and a control unit (130).

[0045] The profile acquisition unit (110) may be configured to acquire a battery profile indicating a correspondence between the voltage and capacity of the battery.

[0046] Here, a battery refers to a physically separate, independent cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. Furthermore, the battery may be of a cylindrical type, a prismatic type, or a pouch type. Furthermore, a battery may refer to a battery bank, a battery module, or a battery pack in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be described below as referring to a single, independent cell.

[0047] For example, a battery profile is a profile that represents the relationship between voltage (V) and capacity (Q) when the battery's SOC is charged from a preset start SOC or 0% to a preset end SOC or 100%. As another example, a battery profile may represent the relationship between voltage (V) and capacity (Q) when the battery's SOC is discharged from a preset start SOC or 100% to a preset end SOC or 0%.

[0048] For example, there are no specific restrictions on the C-rate for charging or discharging to generate a battery profile. However, to obtain a more accurate battery profile, it is preferable to charge or discharge the battery at a low rate. For example, a battery profile can be generated during the process of charging or discharging the battery at 0.05C.

[0049] For example, the profile acquisition unit (110) can directly receive a battery profile from the outside. That is, the profile acquisition unit (110) can acquire a battery profile by receiving the battery profile through a wired and / or wireless connection to the outside.

[0050] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Furthermore, the profile acquisition unit (110) may generate a battery profile based on the received battery information. In other words, the profile acquisition unit (110) may acquire a battery profile by directly generating the battery profile based on the battery information.

[0051] The profile acquisition unit (110) may be connected to the profile adjustment unit (120) so as to be able to communicate with it. For example, the profile acquisition unit (110) may be connected to the profile adjustment unit (120) via wire and / or wirelessly. The profile acquisition unit may transmit the acquired battery profile to the profile adjustment unit (120).

[0052] The profile adjustment unit (120) can be configured to adjust the preset first reference profile (Rp) and second reference profile (Rn) to correspond to the battery profile, and generate the first profile (Rp') according to the adjustment result.

[0053] Here, the first reference profile (Rp) may be a reference positive electrode profile, which may be a profile indicating a correspondence between the capacity and voltage of a reference positive electrode cell preset to correspond to the positive electrode of the battery. For example, the reference positive electrode cell may be a positive electrode of a coin half cell or a three-electrode cell. As a specific example, the first reference profile (Rp) may be preset to correspond to the positive electrode of a battery in the BOL (Beginning of Life) state. In other words, the first reference profile (Rp) may be estimated as the positive electrode profile of a battery in the BOL state.

[0054] In addition, the second reference profile (Rn) may be a reference negative electrode profile, which may be a profile indicating a correspondence between the capacity and voltage of a reference negative electrode cell preset to correspond to the negative electrode of the battery. For example, the reference negative electrode cell may be a negative electrode coin half cell or a negative electrode of a three-electrode cell. As a specific example, the second reference profile (Rn) may be preset to correspond to the negative electrode of a battery in a BOL state. In other words, the second reference profile (Rn) may be estimated as the negative electrode profile of a battery in a BOL state.

[0055] Specifically, the profile adjustment unit (120) can adjust the first reference profile (Rp) and the second reference profile (Rn) to correspond to the battery profile. More specifically, the profile adjustment unit (120) can adjust the first reference profile (Rp) and the second reference profile (Rn) to generate an adjusted first reference profile (Rp) and an adjusted second reference profile (Rn). In addition, the profile adjustment unit (120) can generate a comparison profile from the adjusted first reference profile (Rp) and the adjusted second reference profile (Rn). The profile adjustment unit (120) can adjust the first reference profile (Rp) and the second reference profile (Rn) until the comparison profile corresponds to the battery profile.

[0056] For example, the profile adjustment unit (120) can generate a plurality of comparison profiles by shifting or capacity scaling the first reference profile (Rp) and the second reference profile (Rn), and can specify a comparison profile among the plurality of comparison profiles that has the smallest error with the battery profile. Then, the profile adjustment unit (120) can determine the adjusted first reference profile (Rp) and the adjusted second reference profile (Rn) corresponding to the specified comparison profile as the first profile (Rp') and the second profile (Rn'), respectively. That is, the positive profile indicating the current state of the battery can be estimated as the first profile (Rp'), and the negative profile can be estimated as the second profile (Rn').

[0057] FIG. 2 is a diagram schematically illustrating the results of adjusting a first reference profile (Rp) and a second reference profile (Rn) according to one embodiment of the present invention.

[0058] Specifically, in the embodiment of FIG. 2, the profile adjustment unit (120) can adjust the first reference profile (Rp) and the second reference profile (Rn) to generate the first profile (Rp') and the second profile (Rn'). That is, the first profile (Rp') and the second profile (Rn') are generated according to the organic relationship between the first reference profile (Rp) and the second reference profile (Rn).

[0059] In relation to this, a more specific embodiment in which the profile adjustment unit (120) adjusts the first reference profile (Rp) and the second reference profile (Rn) to correspond to the battery profile and determines the first profile (Rp') of the battery will be described later with reference to FIGS. 3 to 10.

[0060] The control unit (130) may be configured to diagnose the state of the battery based on the first characteristic value of the first characteristic point included in the first profile (Rp').

[0061] Specifically, the first profile (Rp') includes a first feature point corresponding to the positive electrode engagement start point (hereinafter referred to as pi) and a second feature point corresponding to the positive electrode engagement end point (hereinafter referred to as pf). Here, the positive electrode engagement start point refers to the positive electrode point where the reaction starts during the charging process or the positive electrode point where the reaction starts during the discharging process. The positive electrode engagement end point refers to the positive electrode point where the reaction ends during the charging process or the positive electrode point where the reaction ends during the discharging process.

[0062] Similarly, the second profile (Rn') includes a first feature point corresponding to the negative engagement start point (hereinafter referred to as ni) and a second feature point corresponding to the negative engagement end point (hereinafter referred to as nf). Here, the negative engagement start point refers to the negative point where the reaction starts during the charging process or the negative point where the reaction starts during the discharging process. The negative engagement end point refers to the negative point where the reaction ends during the charging process or the negative point where the reaction ends during the discharging process.

[0063] For example, in the embodiment of FIG. 2, the first profile (Rp') may include a first feature point (pi') and a second feature point (pf'). The second profile (Rn') may include a first feature point (ni') and a second feature point (nf').

[0064] The first characteristic value is a value representing at least one of the capacity, voltage, or SOC (State of Charge) of the first characteristic point included in the first profile (Rp'). Preferably, the first characteristic value is the SOC of the first characteristic point included in the first profile (Rp').

[0065] For example, the first feature value can be calculated as the SOC of the first feature point (pi') with respect to the capacity of the first profile (Rp'). Let the entire capacity range of the first profile (Rp') be Qi[Ah] to Qf[Ah], and let the capacity of the first feature point (pi') be Qt[Ah]. The first feature value can be calculated according to the formula "(Qt-Qi)÷(Qf-Qi)×100".

[0066] As another example, the first characteristic value may be calculated as the SOC of the first characteristic point (pi') with respect to the capacity of the second profile (Rn'). As another example, the first characteristic value may be calculated as the SOC of the first characteristic point (pi') with respect to the capacity of the battery profile.

[0067] Specifically, the control unit (130) may be configured to diagnose the state of the battery as a normal state or a state of available lithium loss.

[0068] Here, the "normal state" refers to a state in which battery degradation has occurred at a normal level. In other words, the "normal state" refers to a state in which the battery has deteriorated, but the degree of degradation is normal. Furthermore, the "available lithium loss state" refers to a state in which lithium plating, in which lithium metal is deposited on the surface of the battery's negative electrode, has occurred.

[0069] A battery diagnostic device (100) according to one embodiment of the present invention has the advantage of being able to specifically diagnose the state of a battery based on a first profile (Rp') derived as a result of adjusting a first reference profile (Rp) and a second reference profile (Rn). That is, according to one embodiment of the present invention, since the deterioration pattern of a battery can be specifically diagnosed, the current state of the battery can be qualitatively diagnosed in a non-destructive manner.

[0070]

[0071] Meanwhile, the control unit (130) provided in the battery diagnostic device (100) may optionally include a processor, an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a register, a communication modem, a data processing device, etc. known in the art to execute various control logics performed in the present invention. In addition, when the control logic is implemented in software, the control unit (130) may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the control unit (130). The memory may be located inside or outside the control unit (130) and may be connected to the control unit (130) by various well-known means.

[0072] In addition, the battery diagnostic device (100) may further include a storage unit (140). The storage unit (140) may store data or programs required for each component of the battery diagnostic device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (140) is not particularly limited in type as long as it is a known information storage means known to be capable of recording, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, etc. In addition, the storage unit (140) may store program codes defining processes executable by the control unit (130).

[0073]

[0074] Below, a specific embodiment in which the control unit (130) diagnoses the status of the battery is described.

[0075] In one embodiment, the control unit (130) can diagnose the condition of the battery based on the result of comparing the first characteristic value and the first reference value.

[0076] Here, the first reference value may be preset as the first characteristic value of the reference battery. The reference battery, as compared to the battery according to one embodiment of the present invention, refers to a battery that has undergone only a normal level of deterioration, either experimentally or theoretically.

[0077] Specifically, the first characteristic value can be sensitively changed when the battery's available lithium is lost. That is, whether or not available lithium is lost can be determined based on changes in the first characteristic value. Accordingly, the control unit (130) can diagnose the battery's condition by comparing the first reference value with the first characteristic value.

[0078] For example, the control unit (130) may be configured to diagnose the state of the battery as a state of available lithium loss if the first characteristic value exceeds the first reference value. Conversely, the control unit (130) may be configured to diagnose the state of the battery as a normal state if the first characteristic value is lower than the first reference value.

[0079]

[0080] In another embodiment, the control unit (130) can calculate the available lithium loss rate of the battery based on the first characteristic value, and diagnose the condition of the battery based on the calculated available lithium loss rate.

[0081] The control unit (130) may be configured to calculate an available lithium loss rate based on preset first and second reference values ​​and the first characteristic value. Here, the available lithium loss rate indicates the extent to which the amount of lithium that can be used for charging and discharging has been lost. For example, if the available lithium loss rate is 1%, it means that 1% of the lithium designed to be usable has been lost and cannot be used. In other words, 1% of the lithium designed to be usable may have been deposited as metal on the negative electrode of the battery.

[0082] In one embodiment, the first reference value may be preset as the SOC of the first reference point (pi0) included in the first reference profile (Rp). Here, the first reference point (pi0) of the first reference profile (Rp) corresponds to the first feature point (pi') of the first profile (Rp'). Specifically, since the first reference profile (Rp) corresponds to the positive profile of the battery in the BOL state, the first reference point (pi0) corresponds to the positive electrode participation start point of the battery in the BOL state.

[0083] For example, in the embodiment of FIG. 2, the first reference point (pi0) of the first reference profile (Rp) corresponds to the first feature point (pi') of the first profile (Rp'). And, the first reference value can be calculated as the SOC of the first reference point (pi0) with respect to the capacity of the first reference profile (Rp).

[0084] And, the second reference value can be preset as the SOC of the second reference point (pf0) included in the first reference profile (Rp). Here, the second reference point (pf0) of the first reference profile (Rp) corresponds to the second feature point (pf') of the first profile (Rp'). Specifically, since the first reference profile (Rp) corresponds to the positive profile of the battery in the BOL state, the second reference point (pf0) corresponds to the positive participation end point of the battery in the BOL state.

[0085] For example, in the embodiment of FIG. 2, the second reference point (pf0) of the first reference profile (Rp) corresponds to the second feature point (pf') of the first profile (Rp'). And, the second reference value can be calculated as the SOC of the second reference point (pf0) for the capacity of the first reference profile (Rp).

[0086] Specifically, the control unit (130) can calculate a first difference between a first reference value and a second reference value, calculate a second difference between a first feature value and the first reference value, and calculate a ratio of the second difference to the first difference to calculate an available lithium loss rate.

[0087] For example, the control unit (130) can calculate the available lithium loss rate using Equation 1 below.

[0088] [Formula 1]

[0089]

[0090] Here, L Li is the available lithium loss rate, and pi BOL is the first reference value of the first reference profile (Rp), and pf BOL is the second reference value of the first reference profile (Rp), and pi MOL is the first feature value of the first profile (Rp').

[0091] In another embodiment, the first reference value is the SOC of the first reference point included in the first reference profile (Rp) and the SOC of the first reference point included in the second reference profile (Rn). Specifically, since the second reference profile (Rn) corresponds to the negative profile of the battery in the BOL state, the first reference point corresponds to the negative electrode engagement start point of the battery in the BOL state.

[0092] For example, in the embodiment of FIG. 2, the first reference value can be calculated as the SOC of the first reference point (ni0) for the capacity of the second reference profile (Rn).

[0093] And, the second reference value is the SOC of the second reference point (nf0) included in the second reference profile (Rn). Specifically, since the second reference profile (Rn) corresponds to the negative profile of the battery in the BOL state, the second reference point (nf0) corresponds to the negative participation end point of the battery in the BOL state.

[0094] For example, in the embodiment of FIG. 2, the second reference value can be calculated as the SOC of the second reference point (nf0) for the capacity of the second reference profile (Rn).

[0095] Specifically, the control unit (130) can calculate a first difference between the first reference value and the second reference value of the second reference profile (Rn), calculate a second difference between the first feature value and the first reference value of the first reference profile (Rp), and calculate a ratio of the second difference to the first difference to calculate an available lithium loss rate.

[0096] For example, the control unit (130) may calculate the available lithium loss rate using Equation 2 below.

[0097] [Formula 2]

[0098]

[0099] Here, L Li is the available lithium loss rate, and pi BOL is the first reference value of the first reference profile (Rp), and ni BOL is the first reference value of the second reference profile (Rn), and nf BOL is the second reference value of the second reference profile (Rn), and pi MOL is the first feature value of the first profile (Rp').

[0100] For example, if the first reference value of the first reference profile (Rp) is set to the capacity of the first reference point (pi0) for the capacity of the first reference profile (Rp), the first reference value of the second reference profile (Rn) may also be set to the capacity of the first reference point (ni0) for the capacity of the first reference profile (Rp). As another example, if the first reference value of the first reference profile (Rp) is set to the capacity of the first reference point (pi0) for the capacity of the second reference profile (Rn), the first reference value of the second reference profile (Rn) may also be set to the capacity of the first reference point (ni0) for the capacity of the second reference profile (Rn). That is, since the capacity difference between the first reference point and the second reference point of the first reference profile (Rp) is the same as the capacity difference between the first reference point and the second reference point of the second reference profile (Rn), the difference between the first reference value and the second reference value of the first reference profile (Rp) is the same as the difference between the first reference value and the second reference value of the second reference profile (Rn). That is, in Equations 1 and 2, "pf BOL -pi BOL " is "nf BOL -ni BOL " can be replaced with.

[0101] In the embodiment of Fig. 2, the capacity difference between the first reference point (pi0) and the second reference point (pf0) of the first reference profile (Rp) is equal to the capacity difference between the first reference point (ni0) and the second reference point (nf0) of the second reference profile (Rn). Therefore, the difference (pf) between the first reference value and the second reference value of the first reference profile (Rp) BOL -pi BOL ) is the difference (nf) between the first reference value and the second reference value of the second reference profile (Rn). BOL -ni BOL ) is the same as .

[0102] The control unit (130) may be configured to compare the calculated available lithium loss rate with a preset second reference value.

[0103] Specifically, the second reference value may be preset as the available lithium loss rate of the reference battery. As described above, the reference battery is a battery that is compared with the battery according to one embodiment of the present invention, and refers to a battery that has only undergone a normal level of degradation experimentally or theoretically. For example, the available lithium loss rate of the reference battery may be calculated based on the first reference value, the second reference value, and the first characteristic value of the reference battery, and the calculated available lithium loss rate may be set as the second reference value. As another example, the available lithium loss rate of the reference battery may be calculated by directly measuring the amount of lithium metal precipitated on the negative electrode surface of the reference battery, and the calculated available lithium loss rate may be set as the second reference value.

[0104] The control unit (130) may be configured to diagnose the condition of the battery based on the comparison result.

[0105] For example, the control unit (130) may be configured to diagnose the state of the battery as an available lithium loss state if the available lithium loss rate exceeds the second reference value. Conversely, the control unit (130) may be configured to diagnose the state of the battery as a normal state if the available lithium loss rate is lower than the second reference value. That is, the control unit (130) may diagnose the state of the battery as an available lithium loss state if the available lithium loss rate of the battery is greater than the available lithium loss rate of the reference battery.

[0106]

[0107] In another embodiment, the control unit (130) may diagnose the condition of the battery by considering both the result of comparing the first characteristic value with the first reference value and the result of comparing the available lithium loss rate of the battery with the second reference value.

[0108] The control unit (130) can diagnose the state of the battery by considering the first result of comparing the first characteristic value and the first reference value and the second result of comparing the available lithium loss rate of the battery and the second reference value.

[0109] For example, if both the first result and the second result are normal, the control unit (130) can diagnose the battery status as normal.

[0110] As another example, if both the first result and the second result are available lithium loss states, the control unit (130) can diagnose the state of the battery as an available lithium loss state.

[0111] As another example, the control unit (130) can diagnose the state of the battery as an available lithium loss state if the first result and the second result are different from each other and the second result is an available lithium loss state.

[0112] As another example, if the first and second results are different and the second result is normal, the control unit (130) may diagnose the battery's condition as pending. The control unit (130) may determine that the battery's condition is not a state of loss of available lithium, but requires additional diagnosis. In this case, a diagnostic trouble code (DTC), flag, message, or log indicating that further battery diagnosis is required may be recorded.

[0113]

[0114] Fig. 3 is a graph for reference in explaining an example of each of the first reference profile and the second reference profile. In the graph of Fig. 3, the horizontal axis (X-axis) represents capacity (Ah) and the vertical axis (Y-axis) represents voltage (V).

[0115] Referring to FIG. 3, the storage unit (140) can store a first reference profile (Rp) and a second reference profile (Rn). The reference cell can be a coin-type cell including a positive half-cell and a negative half-cell, or a three-electrode cell.

[0116] The first reference profile (Rp) may be a profile representing the correspondence between the anode voltage and capacity of the reference cell. The anode voltage of the reference cell refers to the potential difference between the potential of the reference electrode (not shown) and the potential of the anode of the reference cell.

[0117] The second reference profile (Rn) may be a profile representing the correspondence between the negative voltage and capacity of the reference cell. The negative voltage of the reference cell refers to the potential difference between the potential of the reference electrode and the potential of the negative electrode of the reference cell.

[0118] Each of the positive voltage and negative voltage can be a closed circuit voltage or an open circuit voltage (OCV).

[0119] A first charging protocol or a first discharging protocol can be utilized to obtain the closed-loop voltages of the positive and negative electrodes of the reference cell, respectively. The first charging protocol can be a constant current charging method using a first current rate. The first discharging protocol can be a constant current discharging method using a first current rate. For example, while the reference cell is continuously charged by the first charging protocol or while the reference cell is continuously discharged by the first discharging protocol, the closed-loop voltages of the positive and negative electrodes of the reference cell, which are measured periodically or aperiodically, can be recorded as the positive voltage and the negative voltage of the reference cell, respectively.

[0120] A second charging protocol or a second discharging protocol may be utilized to obtain the open circuit voltages of the positive and negative electrodes of the reference cell, respectively. The second charging protocol may be an intermittent charging method in which constant current charging using a second current rate and pauses are alternately performed. The second discharging protocol may be an intermittent charging method in which constant current discharging using a second current rate and pauses are alternately performed. The second current rate (e.g., 3.0 C) may be predetermined to be greater than the first current rate (e.g., 0.05 C).

[0121] For example, when the charging time by constant current charging of the second charging protocol has elapsed by a set amount of time or the charging capacity of the reference cell has increased by a set amount of time, charging of the reference cell may be stopped for a set pause time and then constant current charging may be resumed. The charging capacity may be calculated by periodically or aperiodically accumulating sample values ​​of the charging current by the first or second charging protocol.

[0122] As another example, the discharge of the reference cell may be stopped for a predetermined pause time and then the constant current discharge may be resumed whenever the discharge time by the constant current discharge of the second discharge protocol has elapsed by a set amount of time or the discharge capacity of the reference cell has decreased by a set amount of time. The discharge capacity may be calculated by periodically or aperiodically accumulating sample values ​​of the discharge current by the first discharge protocol or the second discharge protocol.

[0123] At this time, the open circuit voltages of the positive and negative electrodes of the reference cell measured at specific timings during each pause can be recorded as the positive and negative voltages of the reference cell.

[0124] For convenience of explanation, it is assumed that the horizontal axis represents the charging capacity in FIGS. 3 to 10.

[0125] At least one of the first reference profile (Rp) and the second reference profile (Rn) can be aligned along the horizontal axis so that the result of synthesizing a portion of the common capacity range of the two profiles (Rp, Rn) (5 to 50 Ah in FIG. 3) matches the third reference profile (R). FIG. 3 illustrates a case where the second reference profile (Rn) is aligned by shifting to the right, with the starting point (the point corresponding to capacity 0) of the first reference profile (Rp) as the reference point.

[0126] It can be confirmed from Fig. 3 that the ends of the first reference profile (Rp) and the second reference profile (Rn) are misaligned. That is, the capacity ranges of the first reference profile (Rp) and the second reference profile (Rn) do not match and only partially overlap. Therefore, the third reference profile (R) represents the full-cell voltage of the reference cell in a portion of the capacity range common to the first reference profile (Rp) and the second reference profile (Rn). That is, the third reference profile (R) is an example of a full-cell voltage profile obtained by directly subtracting a portion of the second reference profile (Rn) from a portion of the first reference profile (Rp).

[0127] The third reference profile (R) can represent the correspondence between the capacity and full-cell voltage of a new, qualified battery cell. In other words, the reference cell has the same positive and negative performance levels as a new, qualified battery cell.

[0128] The third reference profile (R) may represent a relationship between the voltage and capacity of the reference cell over at least a voltage range of interest (e.g., 3.0 to 4.0 V). The lower and upper limits of the voltage range of interest may be a first set voltage (3.0 V in FIG. 3) and a second set voltage (4.0 V in FIG. 3).

[0129] The SOC may be set to 0% when the full-cell voltage of any battery cell, including the reference cell, is equal to the first set voltage. The SOC may be set to 100% when the full-cell voltage of any battery cell, including the reference cell, is equal to the second set voltage. According to Fig. 3, the reference cell can reach a fully charged state (SOC 100%) from a fully discharged state (SOC 0%) with a charge capacity of 45 Ah.

[0130] In this specification, the positive engagement start point on the positive profile of any battery cell represents the positive voltage when the full-cell voltage of the battery cell matches the first set voltage. In addition, the negative engagement start point on the negative profile of the battery cell represents the negative voltage when the full-cell voltage of the battery cell matches the first set voltage. Therefore, the voltage difference between the positive engagement start point and the negative engagement start point is equal to the first set voltage.

[0131] Additionally, the positive engagement endpoint on the positive profile of any battery cell represents the positive voltage when the full-cell voltage of the battery cell matches the second set voltage. Additionally, the negative engagement endpoint on the negative profile of the battery cell represents the negative voltage when the full-cell voltage of the battery cell matches the second set voltage. Therefore, the voltage difference between the positive engagement endpoint and the negative engagement endpoint is equal to the second set voltage.

[0132]

[0133] The storage unit (140) may have information indicating the voltages of each of the reference positive electrode participation start point (pi0), the reference positive electrode participation end point (pf0), the reference negative electrode participation start point (ni0), and the reference negative electrode participation end point (nf0) pre-recorded. The reference positive electrode participation start point (pi0) and the reference positive electrode participation end point (pf0) are the positive electrode participation start point and the positive electrode participation end point on the first reference profile (Rp), respectively. The reference negative electrode participation start point (ni0) and the reference negative electrode participation end point (nf0) are the negative electrode participation start point and the negative electrode participation end point on the second reference profile (Rn), respectively.

[0134] The voltage difference between the reference positive engagement start point (pi0) and the reference negative engagement start point (ni0) may be equal to a first set voltage (e.g., 3.0 V). The voltage difference between the reference positive engagement end point (pf0) and the reference negative engagement end point (nf0) may be equal to a second set voltage (e.g., 4.0 V).

[0135] Fig. 4 is a graph used as a reference to explain an example of a battery profile of a target cell. In the graph of Fig. 4, the horizontal axis (X-axis) represents capacity (Ah) and the vertical axis (Y-axis) represents voltage.

[0136] Referring to FIG. 4, the profile adjustment unit (120) can generate a battery profile (M) indicating a correspondence between the capacity of a battery cell to be diagnosed (hereinafter, referred to as a “target cell”) and the terminal voltage (also referred to as a “full cell voltage”). Here, the terminal voltage refers to the voltage across both ends of the target cell (CCV or OCV), and is distinct from the positive voltage and negative voltage described above. In other words, the terminal voltage of the target cell can be said to be the difference between the positive voltage and negative voltage of the target cell.

[0137] The first charging protocol, the first discharging protocol, the second charging protocol, or the second discharging protocol described above may be used to generate the battery profile (M). Like the third reference profile (R), the battery profile (M) may represent a relationship between the voltage and capacity of the target cell at least over the voltage range of interest (e.g., 3.0 to 4.0 V).

[0138] If the first reference profile (Rp) and the second reference profile (Rn) are obtained by the first charging protocol (or the first discharging protocol), the battery profile (M) may also be based on the voltage time series and capacity time series collected through the charging procedure (or discharging procedure) by the first charging protocol (or the first discharging protocol).

[0139] If the first reference profile (Rp) and the second reference profile (Rn) are obtained by the second charging protocol (or the second discharging protocol), the battery profile (M) may also be based on the voltage time series and capacity time series collected through the charging procedure (or discharging procedure) by the second charging protocol (or the second discharging protocol).

[0140] The voltage time series represents the temporal change in the terminal voltage of the target cell. The capacity time series represents the temporal change in the capacity of the target cell while the target cell is being charged or discharged by the first charge protocol, the first discharge protocol, the second charge protocol, or the second discharge protocol.

[0141] When compared with the third reference profile (R) described above with reference to FIG. 3, the battery profile (M) can represent a realistic correspondence between the capacity of a target cell and the full-cell voltage. The target cell may be a new battery cell requiring verification of whether it is a good product, or a battery cell that has deteriorated after being verified as a good product and is no longer a new product.

[0142] Therefore, as illustrated in FIG. 4, there may be some difference between the battery profile (M) and the third reference profile (R). For example, the voltage of the battery profile (M) is higher than that of the third reference profile (R) at the same capacity value, which is due to a manufacturing defect of the target cell, anode capacity loss, cathode capacity loss, and / or available lithium loss. It is obvious that as the target cell deteriorates through repeated charge and discharge, the difference between the battery profile (M) and the third reference profile (R) will gradually increase. According to FIG. 4, unlike the reference cell described with reference to FIG. 3, the target cell requires a charge capacity of 40 Ah to reach a fully charged state (SOC 100%) from a fully discharged state (SOC 0%), which is 5 Ah less than the charge capacity required to fully charge the reference cell.

[0143]

[0144] Meanwhile, in the embodiments of FIGS. 3 and 4, Ah is used as the unit of the horizontal axis, but this unit may be expressed in other forms. For example, instead of Ah, a percentage % indicating SOC (State Of Charge) may be used as the unit of the horizontal axis.

[0145] When a battery profile (M) is generated, the profile adjustment unit (120) may be configured to compare the battery profile (M) with at least one comparison profile. Here, the comparison profile may be a result of generating a first adjustment profile and a second adjustment profile by adjusting each of the first reference profile (Rp) and the second reference profile (Rn) stored in the storage unit (140), and then synthesizing (combining) the first adjustment profile and the second adjustment profile. Here, the first adjustment profile is a result of adjusting the first reference profile (Rp) and is an adjusted positive profile. The second adjustment profile is a result of adjusting the second reference profile (Rn) and is an adjusted negative profile.

[0146] That is, when the third reference profile (R) is a result of subtracting a portion of the second reference profile (Rn) from a portion of the first reference profile (Rp), the comparison profile can be said to be a result of subtracting a portion of the second adjustment profile from a portion of the first adjustment profile.

[0147] The profile adjustment unit (120) can directly adjust the first reference profile (Rp) and the second reference profile (Rn) to generate at least one comparison profile. Alternatively, the at least one comparison profile can be pre-secured based on the first reference profile (Rp) and the second reference profile (Rn) and stored in the storage unit (140). In this case, the profile adjustment unit (120) can also acquire the comparison profile by accessing the storage unit (140) and reading it.

[0148]

[0149] The profile adjustment unit (120) can generate a plurality of comparison profiles from the first reference profile (Rp) and the second reference profile (Rn) by repeating an adjustment procedure in which each of the first reference profile (Rp) and the second reference profile (Rn) is adjusted to several levels and then synthesized.

[0150] The profile adjustment unit (120) can specify a comparison profile among a plurality of comparison profiles that has a minimum error with respect to the battery profile (M). Then, the profile adjustment unit (120) can determine that the first adjustment profile and the second adjustment profile mapped to the specified comparison profile are the first profile and the second profile of the target cell. Here, the first profile is estimated to be the positive profile of the target cell, and the second profile is estimated to be the negative profile of the target cell.

[0151] In this regard, various methods known at the time of filing of the present invention can be employed to determine the error between two profiles, each expressible in a two-dimensional coordinate system. For example, the absolute integral of the area between the two profiles or the Root Mean Square Error (RMSE) can be used as the error between the two profiles.

[0152] According to this configuration of the present invention, various status information regarding the target cell can be obtained based on the finally determined first and second profiles. The finally determined first and second profiles may be mapped to a comparison profile mapped with a minimum error. In particular, the comparison profile based on the finally determined first and second profiles can be said to be nearly identical to the battery profile (M) in terms of shape, etc.

[0153] Therefore, according to the present invention, a positive electrode profile and a negative electrode profile for a target cell can be obtained even without disassembling the target cell or manufacturing it in the form of a three-electrode battery.

[0154] If the target cell is a new battery cell, the first and second profiles can be analyzed to more easily diagnose whether a defect has occurred in the target cell and, if so, what type of defect it is.

[0155] If the target cell is a battery cell in use after being verified as good, the degree to which the target cell has deteriorated for each deterioration item can be determined through the first and second profiles.

[0156] Moreover, according to one embodiment of the present invention, the positive profile (first profile) and the negative profile (second profile) of the target cell can be obtained in a simple manner. The present invention can be implemented even if only one first reference profile (Rp) and one second reference profile (Rn) are stored in the storage unit (140). That is, there is no need to store a plurality of first reference profiles (Rp) and / or a plurality of second reference profiles (Rn) in the storage unit (140). Accordingly, there is no need for the storage capacity of the storage unit (140) to be high, and there is no need to perform numerous preliminary tests required to secure a plurality of first reference profiles (Rp) and / or a plurality of second reference profiles (Rn).

[0157]

[0158] FIGS. 5 to 7 are drawings for reference in explaining an example of a procedure for generating a comparison profile used for comparison with a battery profile according to one embodiment of the present invention.

[0159] The procedure for generating a comparison profile to be described with reference to FIGS. 5 to 7 proceeds in the following order: a first routine (see FIG. 5) for setting four points (positive engagement start point, positive engagement end point, negative engagement start point, negative engagement end point) to correspond to a voltage range of interest, a second routine (see FIG. 6) for performing profile shifting, and a third routine (see FIG. 7) for performing capacity scaling. That is, the procedure for generating a comparison profile according to one embodiment of the present invention includes the first to third routines.

[0160] First, referring to FIG. 5, the first reference profile (Rp) and the second reference profile (Rn) are the same as those shown in FIG. 3.

[0161] The profile adjustment unit (120) determines the positive participation start point (pi), the positive participation end point (pf), the negative participation start point (ni), and the negative participation end point (nf) on the first reference profile (Rp) and the second reference profile (Rn).

[0162] Either the positive engagement initiation point (pi) or the negative engagement initiation point (ni) depends on the other.

[0163] For example, the profile adjustment unit (120) may divide the positive voltage range from the start point to the end point (or the second set voltage) of the first reference profile (Rp) into a plurality of micro-voltage sections, and then set the boundary points of two adjacent micro-voltage sections among the plurality of micro-voltage sections as positive engagement start points (pi). Each micro-voltage section may have a predetermined size (e.g., 0.01 V). Then, the profile adjustment unit (120) may set a point on the second reference profile (Rn) that is smaller by the first set voltage (e.g., 3 V) than the positive engagement start point (pi) as the negative engagement start point (ni).

[0164] As another example, the profile adjustment unit (120) may divide the negative voltage range from the start point to the end point of the second reference profile (Rn) into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a negative participation start point (ni). Then, the profile adjustment unit (120) may search for a point that is greater than the negative participation start point (ni) by a first set voltage from the first reference profile (Rp), and set the searched point as the positive participation start point (pi).

[0165] Either the positive engagement end point (pf) or the negative engagement end point (nf) depends on the other.

[0166] For example, the profile adjustment unit (120) may divide the voltage range from the second set voltage to the end point of the first reference profile (Rp) into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as the positive participation end point (pf). Then, the profile adjustment unit (120) may set a point on the second reference profile (Rn) that is smaller by the second set voltage (e.g., 4 V) than the positive participation end point (pf) as the negative participation end point (nf).

[0167] As another example, the profile adjustment unit (120) may divide the negative voltage range from the start point to the end point of the second reference profile (Rn) into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a negative participation end point (nf). Then, the profile adjustment unit (120) may search for a point that is larger than the negative participation end point (nf) by a second set voltage from the first reference profile (Rp), and set the searched point as the positive participation end point (pf).

[0168] Once the determination of the positive participation start point (pi), the positive participation end point (pf), the negative participation start point (ni), and the negative participation end point (nf) is completed, the profile adjustment unit (120) shifts at least one of the first reference profile (Rp) and the second reference profile (Rn) to the left or right along the horizontal axis.

[0169] Referring to FIG. 6, the profile adjustment unit (120) can shift the first reference profile (Rp) to the left (low capacity side), shift the second reference profile (Rn) to the right (high capacity side), or both, so that the capacity values ​​of the positive participation start point (pi) and the negative participation start point (ni) match.

[0170] Alternatively, the profile adjustment unit (120) may shift the first reference profile (Rp) to the left, shift the second reference profile (Rn) to the right, or both, so that the voltages of the positive engagement end point (pf) and the negative engagement end point (nf) are identical.

[0171] Fig. 6 illustrates a situation in which only the first reference profile (Rp) is shifted to the left to generate an adjusted first reference profile (Rp'), resulting in the voltage of the positive engagement start point (pi') matching the voltage of the negative engagement start point (ni). The adjusted first reference profile (Rp') is the result of applying an adjustment procedure to the first reference profile (Rp) that shifts it to the left by the voltage difference between the positive engagement start point (pi) and the negative engagement start point (ni). Therefore, the two points (pi, pi') differ only in capacitance and have the same voltage. The two points (pf, pf') differ only in capacitance and have the same voltage.

[0172] When adjustment result profiles (Rp', Rn) shifted by at least one of the first reference profile (Rp) and the second reference profile (Rn) are secured, the profile adjustment unit (120) scales the capacity range of at least one of the adjustment result profiles (Rp', Rn).

[0173] According to the example illustrated in FIG. 6, the profile adjustment unit (120) performs an additional adjustment procedure to contract or expand at least one of the adjusted first reference profile (Rp') and the second reference profile (Rn) along the horizontal axis.

[0174] Referring to FIG. 7, the profile adjustment unit (120) can generate an adjusted first reference profile (Rp') by shrinking or expanding the adjusted first reference profile (Rp') so that the size of the capacity range between the two points (pi', pf') of the adjusted first reference profile (Rp') matches the size of the capacity range of the battery profile (M). At this time, one of the two points (pi', pf') can be fixed. Accordingly, the capacity difference between the two points (pi', pf'') of the adjusted first reference profile (Rp'') can match the capacity range of the battery profile (M).

[0175] In addition, the profile adjustment unit (120) can generate an adjusted second reference profile (Rn') by shrinking or expanding the second reference profile (Rn) so that the size of the capacity range between the two points (ni, nf) of the second reference profile (Rn) matches the size of the capacity range of the battery profile (M). At this time, one of the two points (ni, nf) can be fixed. Accordingly, the capacity difference between the two points (ni, nf') of the adjusted second reference profile (Rn') can match the capacity range of the battery profile (M).

[0176] In Fig. 7, the adjusted first reference profile (Rp'') is a result of contracting the adjusted first reference profile (Rp') illustrated in Fig. 6, and the adjusted second reference profile (Rn') is a result of expanding the second reference profile (Rn) illustrated in Fig. 6.

[0177] The positive participation end point (pf'') on the adjusted first reference profile (Rp'') corresponds to the positive participation end point (pf') on the adjusted first reference profile (Rp'). The negative participation end point (nf') on the adjusted second reference profile (Rn') corresponds to the negative participation end point (nf) on the second reference profile (Rn).

[0178] The capacity difference between the positive engagement start point (pi') and the positive engagement end point (pf'') of the adjusted first reference profile (Rp'') corresponds to the size of the capacity range of the battery profile (M). Similarly, the capacity difference between the negative engagement start point (ni) and the negative engagement end point (nf') of the adjusted second reference profile (Rn') corresponds to the size of the capacity range of the battery profile (M).

[0179] In addition, the capacity range by the two points (pi', pf'') of the adjusted first reference profile (Rp'') matches the capacity range by the two points (ni, nf') of the adjusted second reference profile (Rn'). The profile adjustment unit (120) can generate a comparison profile (S) by subtracting the profile between the two points (pi', pf'') of the adjusted first reference profile (Rp'') from the profile between the two points (ni, nf') of the adjusted second reference profile (Rn').

[0180] The profile adjustment unit (120) can calculate the error (profile error) between the comparison profile (S) and the third reference profile (R).

[0181] The profile adjustment unit (120) can mutually map at least two of the adjusted first reference profile (Rp''), the adjusted second reference profile (Rn'), the positive participation start point (pi'), the positive participation end point (pf''), the negative participation start point (ni), the negative participation end point (nf'), the first scale factor, the second scale factor, the comparison profile (S), and the profile error, and record them in the storage unit (140).

[0182] The first scale factor may represent the ratio of the capacity difference between two points (pi', pf'') to the capacity difference between two points (pi0, pf0). The second scale factor may represent the ratio of the capacity difference between two points (ni, nf') to the capacity difference between two points (ni0, nf0). That is, the first scale factor is a change ratio of the adjusted first reference profile (Rp'') to the first reference profile (Rp), which is a positive change ratio. The second scale factor is a change ratio of the adjusted second reference profile (Rn') to the second reference profile (Rn), which is a negative change ratio.

[0183]

[0184] Meanwhile, as described above, when the anode voltage range of the first reference profile (Rp) is divided into a plurality of micro-voltage sections, the boundary points of two adjacent micro-voltage sections among the plurality of micro-voltage sections can be set as the anode participation start point (pi).

[0185] For example, if the anode voltage range of the first reference profile (Rp) is divided into 100 microvoltage ranges, there may be 100 boundary points that can be set as anode participation start points (pi). Furthermore, if the voltage range that is higher than the second set voltage in the first reference profile (Rp) is divided into 40 microvoltage ranges, there may be 40 boundary points that can be set as anode participation end points (pf). In this case, up to 4,000 different comparison profiles can be generated.

[0186] Of course, those skilled in the art will easily understand that as the size of the micro-voltage section decreases, the maximum number of comparison profiles that can be generated increases, and conversely, as the size of the micro-voltage section increases, the maximum number of comparison profiles that can be generated decreases.

[0187] The profile adjustment unit (120) can identify the minimum among the profile errors of the plurality of comparison profiles generated as described above, and then obtain information mapped to the minimum profile error (e.g., at least one of the positive participation start point, positive participation end point, negative participation start point, negative participation end point, first scale factor, and second scale factor) from the storage unit (140).

[0188]

[0189] FIGS. 8 to 10 are diagrams that are referenced to explain another example of a procedure for generating a comparison profile used for comparison with a battery profile according to one embodiment of the present invention. Note that the embodiments according to FIGS. 8 to 10 are independent of the embodiments according to FIGS. 5 to 7 . Therefore, terms or symbols commonly used in describing the embodiments according to FIGS. 5 to 7 and the embodiments according to FIGS. 8 to 10 should be understood as being limited to each embodiment.

[0190] The procedure for generating a comparison profile to be described with reference to FIGS. 8 to 10 proceeds in the order of a fourth routine (see FIG. 8) for performing capacity scaling, a fifth routine (see FIG. 9) for setting four points (positive participation start point, positive participation end point, negative participation start point, negative participation end point), and a sixth routine (see FIG. 10) for performing profile shifting. That is, the procedure for generating a comparison profile according to another embodiment of the present invention includes the fourth to sixth routines.

[0191] Referring to FIG. 8, the first reference profile (Rp) and the second reference profile (Rn) are the same as those illustrated in FIG. 3.

[0192] The profile adjustment unit (120) applies a first scale factor and a second scale factor selected from a scaling value range to a first reference profile (Rp) and a second reference profile (Rn), respectively, to generate an adjusted first reference profile (Rp') and an adjusted second reference profile (Rn').

[0193] The scaling value range may be predetermined or may vary depending on the ratio of the size of the capacity range of the battery profile (M) to the size of the capacity range of the third reference profile (R). For example, when values ​​spaced by 0.1% of the scaling value range (e.g., 90-99%) (i.e., 90%, 90.1%, 90.2%, 98.9%, 99%) can be selected as the first scale factor and the second scale factor, 91 values ​​can be selected as the first scale factor and the second scale factor, respectively. In this case, a maximum of 8,281 adjusted profile pairs can be generated according to 8,281 (91×91) adjustment levels (combinations of the first scale factor and the second scale factor). An adjusted profile pair means a combination of the first adjusted profile and the second adjusted profile.

[0194] The adjusted first reference profile (Rp') and the adjusted second reference profile (Rn') illustrated in FIG. 8 illustrate the results of applying a first scale factor and a second scale factor less than 100% to the first reference profile (Rp) and the second reference profile (Rn), respectively.

[0195] Since the first scale factor and the second scale factor are less than 100%, the adjusted first reference profile (Rp') is the first reference profile (Rp) contracted along the horizontal axis, and the adjusted second reference profile (Rn') is also the second reference profile (Rn) contracted along the horizontal axis. To facilitate understanding, the starting points of each of the bipolar profile (Rp) and the second reference profile (Rn) are fixed, and only the remaining portion is contracted to the left along the horizontal axis.

[0196] Although the above examples only describe scale factors less than 100%, the scale factor may be greater than 100%.

[0197]

[0198] Referring to FIG. 9, the profile adjustment unit (120) determines the positive participation start point (pi'), the positive participation end point (pf'), the negative participation start point (ni'), and the negative participation end point (nf') on the adjusted first reference profile (Rp') and the adjusted second reference profile (Rn').

[0199] Either the positive engagement start point (pi') or the negative engagement start point (ni') may depend on the other. Furthermore, either the positive engagement end point (pf') or the negative engagement end point (nf') may depend on the other. Furthermore, either the positive engagement start point (pi') or the positive engagement end point (pf') may be set based on the other.

[0200] That is, when any one of the positive engagement start point (pi'), positive engagement end point (pf'), negative engagement start point (ni') and negative engagement end point (nf') is set, the remaining three points can be automatically set by the size of the first set voltage, the second set voltage and / or the capacity range of the battery profile (M) (e.g., a charge capacity of 0 to 100% of SOC).

[0201] For example, the profile adjustment unit (120) may divide the positive voltage range from the starting point to the ending point (or the second set voltage) of the adjusted first reference profile (Rp') into a plurality of micro-voltage sections, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as the positive participation start point (pi'). Then, the profile adjustment unit (120) may set the point on the adjusted second reference profile (Rn) that is smaller by the first set voltage (e.g., 3 V) than the positive participation start point (pi') as the negative participation start point (ni').

[0202] As another example, the profile adjustment unit (120) may divide the negative voltage range from the start point to the end point of the adjusted second reference profile (Rn') into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a negative participation start point (ni'). Then, the profile adjustment unit (120) may search for a point from the first reference profile (Rp) that is larger by a first set voltage than the negative participation start point (ni'), and set the searched point as a positive participation start point (pi').

[0203] As another example, the profile adjustment unit (120) may divide the voltage range from the second set voltage to the end point of the adjusted first reference profile (Rp') into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a positive participation end point (pf'). Then, the profile adjustment unit (120) may search for a point in the adjusted second reference profile (Rn') that is smaller than the positive participation end point (pf') by the second set voltage (e.g., 4 V), and set the searched point as a negative participation end point (nf').

[0204] As another example, the profile adjustment unit (120) may divide the negative voltage range from the start point to the end point of the adjusted second reference profile (Rn') into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a negative participation end point (nf'). Then, the profile adjustment unit (120) may search for a point that is larger than the negative participation end point (nf') by a second set voltage from the adjusted first reference profile (Rp'), and set the searched point as a positive participation end point (pf').

[0205]

[0206] The profile adjustment unit (120) can additionally determine the remaining three points based on the determined point when one of the positive participation start point (pi'), positive participation end point (pf'), negative participation start point (ni'), and negative participation end point (nf') is determined.

[0207] For example, if the positive participation start point (pi') is first determined, the profile adjustment unit (120) may set a point on the adjusted first reference profile (Rp') that has a capacity value greater than the capacity value of the positive participation start point (pi') by the size of the capacity range of the battery profile (M) as the positive participation end point (pf'). In addition, the profile adjustment unit (120) may search for a point lower than the positive participation start point (pi') by the first set voltage from the adjusted second reference profile (Rn') and set the searched point as the negative participation start point (ni'). In addition, the profile adjustment unit (120) may set a point on the adjusted second reference profile (Rn') that has a capacity value greater than the capacity value of the negative participation start point (ni') by the size of the capacity range of the battery profile (M) as the negative participation end point (nf').

[0208] As another example, if the positive participation end point (pf') is first determined, the profile adjustment unit (120) may set a point on the adjusted first reference profile (Rp') that has a capacity value that is smaller by the size of the capacity range of the battery profile (M) than the capacity value of the positive participation end point (pf') as the positive participation start point (pi'). In addition, the profile adjustment unit (120) may search for a point that is lower by a second set voltage than the positive participation end point (pf') from the adjusted second reference profile (Rn') and set the searched point as the negative participation end point (nf'). In addition, the profile adjustment unit (120) may set a point on the adjusted second reference profile (Rn') that has a capacity value that is smaller by the size of the capacity range of the battery profile (M) than the capacity value of the negative participation end point (nf') as the negative participation start point (ni').

[0209] As another example, when the negative participation start point (ni') is determined, the profile adjustment unit (120) may set a point on the adjusted second reference profile (Rn') that has a capacity value that is greater than the capacity value of the negative participation start point (ni') by the size of the capacity range of the battery profile (M) as the negative participation end point (nf'). In addition, the profile adjustment unit (120) may search for a point that is higher than the negative participation start point (ni') by the first set voltage from the adjusted first reference profile (Rp') and set the searched point as the positive participation start point (pi'). In addition, the profile adjustment unit (120) may set a point on the adjusted first reference profile (Rp') that has a capacity value that is greater than the capacity value of the positive participation start point (pi') by the size of the capacity range of the battery profile (M) as the positive participation end point (pf').

[0210] As another example, when the negative participation end point (nf') is determined, the profile adjustment unit (120) may set a point on the adjusted second reference profile (Rn') that has a capacity value that is smaller by the size of the capacity range of the battery profile (M) than the capacity value of the negative participation end point (nf') as the negative participation start point (ni'). In addition, the profile adjustment unit (120) may search for a point higher by the second set voltage than the negative participation end point (nf') from the adjusted first reference profile (Rp') and set the searched point as the positive participation end point (pf'). In addition, the profile adjustment unit (120) may set a point on the adjusted first reference profile (Rp') that has a capacity value that is smaller by the size of the capacity range of the battery profile (M) than the capacity value of the positive participation end point (pf') as the positive participation start point (pi').

[0211]

[0212] When the determination of the positive participation start point (pi'), the positive participation end point (pf'), the negative participation start point (ni'), and the negative participation end point (nf') is completed based on the pair of the first scale factor and the second scale factor, the profile adjustment unit (120) can shift at least one of the adjusted first reference profile (Rp') and the adjusted second reference profile (Rn') to the left or right along the horizontal axis so that the capacity values ​​of the positive participation start point (pi') and the negative participation start point (ni') match, or so that the capacity values ​​of the positive participation end point (pf') and the negative participation end point (nf') match.

[0213] The adjusted second reference profile (Rn'') illustrated in Fig. 10 is only the adjusted second reference profile (Rn') illustrated in Fig. 9 shifted to the right. Accordingly, the capacity values ​​of the positive participation start point (pi') and the negative participation start point (ni'') are matched with each other. In this regard, since the capacity difference between the positive participation start point (pi') and the positive participation end point (pf') is the same as the capacity difference between the negative participation start point (ni') and the negative participation end point (nf'), when the capacity values ​​of the positive participation start point (pi') and the negative participation start point (ni'') are matched with each other, the capacity values ​​of the positive participation end point (pf') and the negative participation end point (nf') are also matched with each other.

[0214] Referring to FIG. 10, the profile adjustment unit (120) can generate a comparison profile (U) by subtracting a partial profile between two points (pi', pf') of the adjusted first reference profile (Rp') from a partial profile between two points (ni'', nf'') of the adjusted second reference profile (Rn'').

[0215] The profile adjustment unit (120) can calculate the error (profile error) between the comparison profile (U) and the third reference profile (R).

[0216] The profile adjustment unit (120) can map at least two of the adjusted first reference profile (Rp'), the adjusted second reference profile (Rn''), the positive participation start point (pi'), the positive participation end point (pf'), the negative participation start point (ni''), the negative participation end point (nf''), the first scale factor, the second scale factor, the comparison profile (U), and the profile error to each other, and record them in the storage unit (140).

[0217]

[0218] As described above, the profile adjustment unit (120) can generate a comparison profile corresponding to each pair of the first scale factor and the second scale factor selected from the scaling value range. Since there are multiple pairs of the first scale factor and the second scale factor, it is obvious that multiple comparison profiles will also be generated. The profile adjustment unit (120) can identify the minimum value among the profile errors of the multiple comparison profiles, and then obtain information mapped to the minimum profile error from the storage unit (140).

[0219]

[0220] Figure 11 is a drawing referenced to explain the difference between the first battery and the second battery.

[0221] The first battery is a reference battery, and the second battery is a battery that has lost available lithium. Specifically, the second battery is a battery that has lost available lithium due to an overhang defect.

[0222] Here, "overhang" refers to a condition in which the battery's negative electrode area is larger than the positive electrode area. In other words, an overhang defect refers to a defect in which the negative electrode area is smaller than the positive electrode area. Overhang defects can occur due to manufacturing issues or battery damage. In particular, batteries with overhang defects are known to exhibit more lithium metal precipitation in the edge region of the negative electrode than in the center region.

[0223] For example, when analyzing a battery with an overhang defect using Raman spectroscopy, the central I D / I G I of the periphery than the ratio D / I G The ratio appears higher. Therefore, overhang defects may be one cause of available lithium loss.

[0224] In the embodiment of Fig. 11, the first characteristic value (pi) of the first battery in the BOL state BOL ) and the first characteristic value (pi) of the second battery in BOL state BOL ) is the same at 6.7%.

[0225] The first characteristic value (pi) of the first battery in the middle of life (MOL) state MOL ) is 6.9%, and the first characteristic value (pi) of the second battery in MOL state MOL ) is 7.8%. That is, the first characteristic value (pi) of the second battery with overhang defect MOL ) is the first characteristic value (pi) of the reference battery MOL ) is greater than. Here, the first characteristic value (pi) of the first battery in the MOL state MOL ) can be set as a first reference value. Accordingly, the control unit (130) can diagnose the state of the battery based on the result of comparing the first characteristic value of the battery with the preset first reference value.

[0226] Available lithium loss rate (L) of the first battery in MOL state Li ) is 0.2%, and the available lithium loss rate in the MOL state (L Li ) is 1.4%. That is, the available lithium loss rate (L) of the second battery with overhang defect Li ) is the available lithium loss rate (L) of the reference battery Li ) is greater than that of the first battery in the MOL state. Here, the available lithium loss rate (L Li ) can be set as a second reference value. Accordingly, the control unit (130) can diagnose the state of the battery based on the result of comparing the available lithium loss rate of the battery with the preset second reference value.

[0227] On the other hand, the positive electrode capacity loss rate (L) of the first battery in the MOL state Q ) is 6.8%, and the cathode capacity loss rate (L) of the second battery in MOL state Q) is 6.6%. That is, since the positive electrode capacity loss rates of the first and second batteries show a difference within a certain level, the degree of loss of the positive electrode capacity of the second battery is normal.

[0228] In summary of Fig. 11, the first reference value (the first characteristic value (pi) of the first battery MOL )) and the first characteristic value (pi) of the second battery MOL ) based on the first result compared, the control unit (130) can diagnose the state of the battery as a state of available lithium loss.

[0229] In addition, the second reference value (available lithium loss rate of the first battery (L Li )) and the available lithium loss rate of the second battery (L Li ) based on the second result compared, the control unit (130) can diagnose the state of the battery as a state of available lithium loss.

[0230] Preferably, since the first result and the second result are the same, the control unit (130) can diagnose the state of the battery as a state of available lithium loss.

[0231]

[0232] The battery diagnosis device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the above-described battery diagnosis device (100). In this configuration, at least some of the components of the battery diagnosis device (100) can be implemented by supplementing or adding functions of the components included in a conventional BMS. For example, the profile acquisition unit (110), the profile adjustment unit (120), and the control unit (130) of the battery diagnosis device (100) can be implemented as components of the BMS.

[0233] Additionally, the battery diagnostic device (100) according to the present invention may be installed in a battery pack. That is, the battery pack according to the present invention may include the battery diagnostic device (100) described above and one or more battery cells. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.

[0234] FIG. 12 is a drawing showing an exemplary configuration of a battery pack (10) including a battery diagnostic device (100) (100) according to one embodiment of the present invention.

[0235] The positive terminal of the battery (11) can be connected to the positive terminal (P+) of the battery pack (10), and the negative terminal of the battery (11) can be connected to the negative terminal (P-) of the battery pack (10).

[0236] The measuring unit (12) can be connected to a first sensing line (SL1), a second sensing line (SL2), and a third sensing line (SL3). Specifically, the measuring unit (12) can be connected to a positive terminal of the battery (11) through the first sensing line (SL1), and can be connected to a negative terminal of the battery (11) through the second sensing line (SL2). The measuring unit (12) can measure the voltage of the battery (11) based on the voltage measured at each of the first sensing line (SL1) and the second sensing line (SL2).

[0237] And, the measuring unit (12) can be connected to the current measuring unit (A) through the third sensing line (SL3). For example, the current measuring unit (A) can be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery (11). The measuring unit (12) can measure the charging current of the battery (11) through the third sensing line (SL3) to calculate the charging amount. In addition, the measuring unit (12) can measure the discharging current of the battery (11) through the third sensing line (SL3) to calculate the discharging amount.

[0238] An external device may be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (10). For example, the external device may be a charging device or a load. In addition, the positive terminal of the battery (11), the positive terminal (P+) of the battery pack (10), the external device, the negative terminal (P-) of the battery pack (10), and the negative terminal of the battery (11) may be electrically connected.

[0239]

[0240] FIG. 13 is a schematic drawing of a vehicle (1200) according to another embodiment of the present invention.

[0241] Referring to FIG. 13, a battery pack according to an embodiment of the present invention may be included in a vehicle (1200), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (1210) may drive the vehicle (1200) by supplying power to a motor through an inverter provided in the vehicle (1200). Here, the battery pack (1210) may include a battery diagnostic device (100). That is, the vehicle (1200) may include a battery diagnostic device (100). In this case, the battery diagnostic device (100) may be an onboard device included in the vehicle (1200).

[0242]

[0243] FIG. 14 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.

[0244] Referring to FIG. 14, the battery diagnosis method may include a profile acquisition step (S100), a profile adjustment step (S200), and a battery diagnosis step (S300).

[0245] Preferably, each step of the battery diagnosis method can be performed by a battery diagnosis device (100). For convenience of explanation, any content that overlaps with the previously described content will be omitted or briefly described below.

[0246] The profile acquisition step (S100) is a step of acquiring a battery profile indicating a correspondence between the voltage and capacity of the battery, and can be performed by the profile acquisition unit (110).

[0247] For example, the profile acquisition unit (110) can directly receive a battery profile from the outside. That is, the profile acquisition unit (110) can acquire a battery profile by receiving the battery profile through a wired and / or wireless connection to the outside.

[0248] As another example, the profile acquisition unit (110) may receive battery information regarding the voltage and capacity of the battery. Furthermore, the profile acquisition unit (110) may generate a battery profile based on the received battery information. In other words, the profile acquisition unit (110) may acquire a battery profile by directly generating the battery profile based on the battery information.

[0249] The profile adjustment step (S200) is a step of adjusting the preset first reference profile and second reference profile to correspond to the battery profile and generating the first profile according to the adjustment result, and can be performed by the profile adjustment unit (120).

[0250] For example, the profile adjustment unit (120) can generate a plurality of comparison profiles by shifting or capacity scaling the first reference profile and the second reference profile, and can specify a comparison profile among the plurality of comparison profiles that has the smallest error with the battery profile. In addition, the profile adjustment unit (120) can determine the adjusted first reference profile and the adjusted second reference profile corresponding to the specified comparison profile as the first profile and the second profile, respectively.

[0251] The battery diagnosis step (S300) is a step of diagnosing the state of the battery based on the first characteristic value of the first characteristic point included in the first profile, and can be performed by the control unit (130).

[0252] In one embodiment, the control unit (130) can diagnose the condition of the battery based on the result of comparing the first characteristic value and the first reference value.

[0253] In another embodiment, the control unit (130) can calculate the available lithium loss rate of the battery based on the first characteristic value, and diagnose the condition of the battery based on the calculated available lithium loss rate.

[0254] In another embodiment, the control unit (130) may diagnose the condition of the battery by considering both the result of comparing the first characteristic value with the first reference value and the result of comparing the available lithium loss rate of the battery with the second reference value.

[0255]

[0256] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

[0257] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0258] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of ​​the present invention.

[0259] (Explanation of symbols)

[0260] 10: Battery pack

[0261] 11: Battery

[0262] 12: Measurement section

[0263] 100: Battery Diagnostic Device

[0264] 110: Profile acquisition section

[0265] 120: Profile Adjustment Section

[0266] 130: Control unit

[0267] 140: Storage

[0268] 1300: Car

[0269] 1310: Battery Pack

Claims

1. A profile acquisition unit configured to acquire a battery profile indicating a correspondence between the voltage and capacity of the battery; A profile adjustment unit configured to adjust the preset first reference profile and second reference profile to correspond to the battery profile and generate the first profile according to the adjustment result; and A battery diagnosis device characterized by including a control unit configured to diagnose the state of the battery based on a first characteristic value for a first characteristic point included in the first profile.

2. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to diagnose the state of the battery as a normal state or an available lithium loss state.

3. In paragraph 2, The above control unit, If the above first characteristic value exceeds the preset first reference value, the state of the battery is diagnosed as the available lithium loss state, A battery diagnosis device characterized in that it is configured to diagnose the state of the battery as the normal state when the first characteristic value is less than or equal to the first reference value.

4. In paragraph 2, The above control unit, A battery diagnosis device characterized in that it is configured to calculate an available lithium loss rate based on preset first reference values and second reference values and the first characteristic value, compare the calculated available lithium loss rate with the preset second reference value, and diagnose the state of the battery based on the comparison result.

5. In paragraph 4, The above control unit, If the above available lithium loss rate exceeds the above second reference value, the state of the battery is diagnosed as the available lithium loss state, A battery diagnostic device characterized in that it is configured to diagnose the state of the battery as the normal state when the available lithium loss rate is less than or equal to the second reference value.

6. In paragraph 4, The above first reference value is, Pre-set to the SOC of the first reference point included in the above first reference profile, The above second reference value is, A battery diagnostic device characterized in that the SOC of the second reference point included in the first reference profile is preset.

7. In paragraph 1, The above first feature value is, A battery diagnostic device characterized in that the SOC of the first characteristic point included in the first profile is.

8. A battery pack including a battery diagnostic device according to any one of claims 1 to 7.

9. A vehicle including a battery diagnostic device according to any one of claims 1 to 7.

10. A profile acquisition step for acquiring a battery profile indicating the correspondence between the voltage and capacity of the battery; A profile adjustment step for adjusting the preset first reference profile and second reference profile to correspond to the battery profile and generating the first profile according to the adjustment result; and A battery diagnosis method, characterized by including a battery diagnosis step of diagnosing the state of the battery based on a first characteristic value of a first characteristic point included in the first profile.

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