Battery diagnostic device and method

Abstract

The battery diagnostic method according to the present invention comprises the steps of: generating, for every predetermined number of charging cycles or discharging cycles, a battery profile showing the relationship between a capacity and a voltage of a target battery; obtaining, on the basis of the battery profile, a negative electrode profile in which the relationship between a negative electrode capacity and a negative electrode potential of the target battery is estimated; obtaining a diagnosis factor value indicating the available capacity per unit area of the negative electrode, on the basis of the negative electrode profile; and diagnosing the state of the negative electrode on the basis of diagnosis factor values sequentially obtained as the charging cycle or discharging cycle is repeated.

Description

Battery diagnostic device and method

[0001] This application claims priority from Korean Patent Application No. 10-2024-0011541, filed January 25, 2024, the entire disclosure of which is 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 non-destructively diagnosing the state of a rechargeable battery.

[0003] Recently, with the rapid increase in demand for portable electronic products such as laptops, digital cameras, and mobile phones, and the full-scale development of electric vehicles, energy storage systems, robots, and satellites, research on high-performance rechargeable batteries is actively being conducted.

[0004] Rechargeable batteries include lithium batteries that utilize lithium ions, such as lithium-ion batteries and lithium-ion polymer batteries, as well as nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. Among these, lithium batteries offer a relatively long lifespan due to minimal memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density. Consequently, their application scope is gradually expanding.

[0005] The positive and negative electrodes of these batteries gradually deteriorate, losing their original electrical capacity as they undergo repeated charge and discharge cycles. Therefore, accurate diagnosis of battery condition is essential to accurately predict the battery's usable lifespan, remaining service life, and replacement timing.

[0006] However, since existing technologies diagnose batteries through the State of Health (SOH) of the entire battery, if an active material that undergoes phase transformation, such as pure silicon (Pure Si), is applied to the battery's negative electrode, there is a problem in that the state of the negative electrode cannot be diagnosed separately from the state of the battery's positive electrode. This is because active materials that undergo phase transformation as charge and discharge progress do not degrade with repeated charge and discharge, but rather can provide greater usable capacity.

[0007] The technical problem to be solved by the present invention is to provide a battery diagnosis device and method capable of diagnosing the state of the negative electrode of a target battery separately from the state of the positive electrode of the target battery, even when an active material that undergoes phase transformation, such as pure silicon, is applied to the negative electrode of the target battery.

[0008] Another technical problem to be solved by the present invention is to provide a battery diagnosis device and method capable of accurately diagnosing the degree of activation or deterioration of the negative electrode of a target battery and delaying the deterioration of the negative electrode.

[0009] Another technical problem to be solved by the present invention is to provide a battery pack including the battery diagnostic device.

[0010] Another technical problem that the present invention seeks to solve is to provide a vehicle including the battery diagnostic device.

[0011] A battery diagnosis method according to one aspect of the present invention is a method for diagnosing a target battery having a negative electrode to which an active material that undergoes a phase transformation as charge and discharge proceeds is applied, the method comprising: generating a battery profile indicating a relationship between a capacity and a voltage of the target battery for each predetermined number of charge cycles or discharge cycles; obtaining a negative electrode profile that estimates a relationship between a negative electrode capacity and a negative electrode potential of the target battery based on the battery profile; obtaining a diagnostic factor value indicating an available capacity per unit area of ​​the negative electrode based on the negative electrode profile; and diagnosing a state of the negative electrode based on diagnostic factor values ​​sequentially obtained as the charge cycle or the discharge cycle is repeated.

[0012] In one embodiment, the battery diagnosis method may further include, prior to the step of generating the battery profile, a step of measuring a voltage value of the target battery using a voltage sensor while the predetermined number of charge cycles or discharge cycles are in progress.

[0013] In one embodiment, the battery diagnosis method further includes, before the step of obtaining the negative profile, a step of adjusting a reference positive profile indicating a relationship between a positive electrode capacity and a positive electrode potential of a predetermined reference battery and a reference negative profile indicating a relationship between a negative electrode capacity and a negative electrode potential of the reference battery, respectively, to generate a plurality of adjusted positive electrode profiles that are adjusted differently from each other and a plurality of adjusted negative electrode profiles that are adjusted differently from each other, and the step of obtaining the negative profile may include a step of selecting an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the battery profile from among the plurality of adjusted positive electrode profiles and the plurality of adjusted negative electrode profiles, and obtaining the selected adjusted negative electrode profile as the negative electrode profile of the target battery.

[0014] In one embodiment, the step of obtaining the diagnostic factor value may include a step of calculating the diagnostic factor value based on a negative electrode shrinkage ratio indicating a degree of shrinkage of the negative electrode profile compared to a reference negative electrode profile indicating a relationship between a negative electrode capacity and a negative electrode potential of a given reference battery, and a predetermined reference value regarding the diagnostic factor.

[0015] In one embodiment, the step of diagnosing the state of the negative electrode may include a step of diagnosing that degradation of the negative electrode is in progress when the diagnostic factor values ​​show a trend of increasing and then decreasing for a predetermined period of time as the charging cycle or the discharging cycle is repeated.

[0016] In one embodiment, the step of diagnosing the state of the cathode may include the step of determining a maximum value among the diagnostic factor values; and the step of diagnosing the state of the cathode as an abnormal state if another diagnostic factor value acquired after the time point of acquiring the diagnostic factor value corresponding to the maximum value is less than a predetermined threshold value.

[0017] In one embodiment, the battery diagnosis method may further include, after the step of diagnosing the state of the negative electrode, a step of adjusting a charging condition or a discharging condition of the target battery according to the diagnosis result of the state of the negative electrode.

[0018] In one embodiment, the active material may be silicon.

[0019] According to another aspect of the present invention, a battery diagnosis device is a device for diagnosing a target battery having a negative electrode to which an active material is applied that undergoes a phase transformation as charge and discharge are repeated, the device comprising: a battery profile generation unit for generating a battery profile indicating a relationship between a capacity and a voltage of the target battery for each predetermined number of charge cycles or discharge cycles; a negative electrode profile acquisition unit for obtaining a negative electrode profile that estimates a relationship between a negative electrode capacity and a negative electrode potential of the target battery based on the battery profile; a diagnosis factor acquisition unit for obtaining a diagnosis factor value indicating an available capacity per unit area of ​​the negative electrode based on the negative electrode profile; and a diagnosis unit for diagnosing a state of the negative electrode based on diagnosis factor values ​​sequentially obtained by the diagnosis factor acquisition unit as the charge cycle or the discharge cycle is repeated.

[0020] In one embodiment, the negative profile acquisition unit may include a first module that adjusts a reference positive profile indicating a relationship between a positive electrode capacity and a positive electrode potential of a predetermined reference battery and a reference negative electrode profile indicating a relationship between a negative electrode capacity and a negative electrode potential of the reference battery, respectively, to generate a plurality of adjusted positive electrode profiles that are adjusted differently from each other and a plurality of adjusted negative electrode profiles that are adjusted differently from each other; and a second module that selects an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the battery profile from among the plurality of adjusted positive electrode profiles and the plurality of adjusted negative electrode profiles, and acquires the selected adjusted negative electrode profile as the negative electrode profile of the target battery.

[0021] In one embodiment, the diagnostic unit may be configured to diagnose that degradation of the negative electrode is in progress when the diagnostic factor values ​​increase as the charging cycle or the discharging cycle is repeated and then decrease for a predetermined period of time or longer.

[0022] In one embodiment, the diagnostic unit may be configured to diagnose the state of the cathode as abnormal if another diagnostic factor value acquired after the time point of acquiring the diagnostic factor value corresponding to the maximum value among the diagnostic factor values ​​is less than a predetermined threshold value.

[0023] A battery pack according to another aspect of the present invention includes the battery diagnostic device described above.

[0024] A vehicle according to another aspect of the present invention includes the battery diagnostic device described above.

[0025] According to the present invention, a battery diagnosis device is configured to generate a battery profile indicating a relationship between a capacity and a voltage of a target battery for each predetermined number of charge cycles or discharge cycles, obtain a cathode profile estimating a relationship between a cathode capacity and a cathode potential of the target battery based on the generated battery profile, and diagnose a state of a cathode of the target battery based on diagnostic factor values ​​obtained from the cathode profile, so that even when an active material that undergoes a phase transformation, such as pure silicon, is applied to the cathode of the target battery, the state of the cathode can be diagnosed separately from the state of the cathode of the target battery.

[0026] In addition, the battery diagnostic device is configured to accurately diagnose the degree of activation or deterioration of the negative electrode of the target battery and adjust the charging and / or discharging conditions of the target battery according to the diagnosis result, thereby delaying the deterioration of the negative electrode of the target battery and extending its lifespan.

[0027] Furthermore, those skilled in the art will readily understand from the following description that various embodiments of the present invention can solve various technical problems not mentioned above.

[0028] FIG. 1 is a block diagram showing a battery diagnostic device according to one embodiment of the present invention.

[0029] Figure 2 is a graph showing the capacity and resistance of a battery that change according to the number of charge and discharge cycles.

[0030] Figure 3 is a drawing showing a reference positive electrode profile and a reference negative electrode profile corresponding to a predetermined reference battery profile.

[0031] Figure 4 is a drawing showing the battery profile of the target battery.

[0032] FIG. 5 is a diagram illustrating a first process of setting four points to correspond to a voltage range of interest during a combination profile generation procedure according to one embodiment of the present invention.

[0033] Figure 6 is a drawing showing a second process for performing a profile shift during the above combination profile creation procedure.

[0034] Figure 7 is a diagram showing a third process for performing capacity scaling during the above combination profile generation procedure.

[0035] FIG. 8 is a diagram illustrating a fourth process for performing capacity scaling during a combination profile generation procedure according to another embodiment of the present invention.

[0036] Figure 9 is a diagram showing the fifth process of setting four points during the above combination profile creation procedure.

[0037] Figure 10 is a drawing showing the sixth process for performing profile shift during the above combination profile creation procedure.

[0038] Fig. 11 is a flowchart illustrating a battery diagnosis method according to one embodiment of the present invention.

[0039] FIG. 12 is a drawing showing a battery pack according to one embodiment of the present invention.

[0040] Fig. 13 is a drawing showing a vehicle according to one embodiment of the present invention.

[0041] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings to clarify solutions addressing the technical challenges of the present invention. However, if a description of a related known technology obscures the essence of the present invention, the description thereof may be omitted.

[0042] Additionally, the terms used in this specification are defined based on their functions within the present invention, and may vary depending on the intent or custom of the designer, manufacturer, etc. Therefore, the definitions of terms described below should be based on the contents throughout this specification.

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

[0044] As illustrated in FIG. 1, a battery diagnostic device (100) according to one embodiment of the present invention is a device configured to diagnose the state of a rechargeable battery, and includes a battery profile generation unit (110), a negative profile acquisition unit (120), a diagnostic factor acquisition unit (130), and a diagnostic unit (140).

[0045] The battery (hereinafter, “target battery”) to be diagnosed by the battery diagnosis device (100) according to the present invention may be a battery cell corresponding to a basic unit of charging and discharging, a battery module in which multiple battery cells are connected in series and / or parallel, or a battery pack in which multiple battery cells or multiple battery modules are connected in series and / or parallel.

[0046] In this case, the target battery may include an electrode assembly in which a positive electrode and a negative electrode are mutually stacked with a separator interposed therebetween, and a case that accommodates the electrode assembly together with an electrolyte material.

[0047] Meanwhile, the positive electrode of the electrode assembly may include a positive electrode substrate made of a material including aluminum, and a positive electrode active material applied to the positive electrode substrate. The positive electrode active material may include a lithium-based oxide. The positive electrode active material may be applied to the positive electrode substrate together with a conductive material, a binder, and the like.

[0048] In addition, the negative electrode of the electrode assembly may include a negative electrode substrate made of a material including copper, and a negative electrode active material applied to the negative electrode substrate. The negative electrode active material may be silicon (Si) or silicon oxide (SiO x ) may include a silicon-based material, or may include graphite together with a silicon-based material. Such a negative electrode active material may be applied to the negative electrode substrate together with a conductive material, a binder, etc.

[0049] In particular, in one embodiment of the present invention, the negative active material may be pure silicon (Pure Si). Pure silicon is a material that undergoes a phase transformation or allotropic transformation from a crystalline state to an amorphous state during activation after the production of the target battery. This phase transformation of pure silicon can be confirmed through Electron Backscattered Diffraction (EBSD) analysis.

[0050] Batteries with pure silicon-based anodes have a relatively high NP ratio, resulting in a relatively small portion of the anode area being utilized for charge and discharge compared to the cathode. Therefore, only a portion of the anode area utilized for charge and discharge is utilized, and this area undergoes a phase transformation from crystalline to amorphous, becoming active. Furthermore, the utilization area of ​​pure silicon-based anodes gradually changes as charge and discharge cycles progress.

[0051] Thus, when an active material undergoing phase transformation is applied to the target battery's cathode, it is difficult to accurately diagnose the target battery's condition. This is because active materials undergoing phase transformation during charge / discharge cycles do not degrade with repeated charge / discharge cycles, but rather provide greater usable capacity.

[0052] Table 1 below shows the cathode loading (N loading) and available lithium loss of a battery with a pure silicon cathode according to the number of charge / discharge cycles.

[0053] Number of cycles n-loading [mAh / cm 2 ] Available Lithium Loss [%] BOL6.010.03007.921.82

[0054] In Table 1, BOL represents the beginning of life (BOL) point of the target battery, and n-loading represents the negative electrode loading of the target battery, i.e., the available capacity per unit area of ​​the negative electrode. As shown in Table 1, as the number of charge / discharge cycles of the target battery increases up to 300, the negative electrode capacity of the target battery increases, while the positive electrode capacity of the target battery may decrease due to the loss of available lithium. Therefore, the change in the overall capacity of the target battery due to the increase in charge / discharge cycles appears in a different pattern from the change in the negative electrode capacity of the target battery.

[0055] Figure 2 is a graph showing the capacity and resistance of a target battery that change according to the number of charge / discharge cycles.

[0056] As illustrated in Figure 2, the total capacity of the target battery with the pure silicon-based cathode increases up to the 100th cycle and then gradually decreases. Furthermore, the resistance of the target battery decreases up to the 100th cycle and then increases. In other words, the change in the total capacity of the target battery with increasing charge / discharge cycles exhibits a different pattern from the change in the cathode capacity of the target battery.

[0057] Therefore, in order to accurately diagnose the condition of the target battery, it is necessary to diagnose the condition of the negative electrode separately from the condition of the positive electrode.

[0058] A battery diagnostic device (100) according to the present invention is configured to diagnose a battery having a negative electrode to which an active material is applied that undergoes phase transformation as charging and discharging proceeds.

[0059] Referring again to FIG. 1, the battery profile generation unit (110) of the battery diagnosis device (100) is configured to generate a battery profile indicating the relationship between the capacity and voltage of the target battery for each predetermined number of charging or discharging cycles.

[0060] In one embodiment, the battery profile generation unit (110) may be configured to measure voltage values ​​for each capacity of the target battery using a voltage sensor (14a) while a predetermined number of charge cycles or discharge cycles are in progress, and to generate the battery profile based on the measured voltage values.

[0061] For reference, the current capacity of the target battery can be calculated by applying the current integration method to the charging or discharging current of the target battery. To this end, the battery profile generation unit (110) may be linked to or include a current sensor (12b) that senses the charging or discharging current of the target battery.

[0062] The negative profile acquisition unit (120) is configured to acquire a negative profile that estimates the relationship between the negative electrode capacity and negative electrode potential of the target battery based on the battery profile. To this end, the negative profile acquisition unit (120) may include a first module (122) and a second module (124).

[0063] In this case, the first module (122) may be configured to generate a plurality of adjusted positive electrode profiles that are adjusted differently from each other and a plurality of adjusted negative electrode profiles that are adjusted differently from each other by adjusting a reference positive electrode profile that represents a relationship between a positive electrode capacity and a positive electrode potential of a predetermined reference battery and a reference negative electrode profile that represents a relationship between a negative electrode capacity and a negative electrode potential of the reference battery, respectively. For reference, the reference battery may be a target battery at the BOL (Beginning of Life) point in time or a battery in a normal state with the same configuration as the target battery.

[0064] The second module (124) may be configured to select an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the battery profile from among the plurality of adjusted positive electrode profiles and the plurality of adjusted negative electrode profiles, and to obtain the selected adjusted negative electrode profile as the negative electrode profile of the target battery.

[0065] The above diagnostic factor acquisition unit (130) is configured to acquire a diagnostic factor value representing the available capacity per unit area of ​​the cathode based on the cathode profile.

[0066] As will be described again below, the diagnostic factor acquisition unit (130) may be configured to calculate the diagnostic factor value based on a predetermined reference value for the diagnostic factor and a negative electrode shrinkage ratio indicating the degree to which the negative electrode profile has shrunk compared to a reference negative electrode profile indicating the relationship between the negative electrode capacity and negative electrode potential of the reference battery.

[0067] For example, the above diagnostic factor value (n-loading) can be calculated as in mathematical expression 1.

[0068] [Mathematical Formula 1]

[0069] n-loading = (ns / 100) × Ln [mAh / cm 2 ]

[0070] In mathematical expression 1, n-loading is a diagnostic factor indicating the available capacity per unit area of ​​the negative electrode, ns is the negative electrode shrinkage ratio indicating the degree to which the negative electrode profile of the target battery is shrunk compared to the reference negative electrode profile, and Ln represents the reference available capacity per unit area of ​​the negative electrode.

[0071] The above diagnostic unit (140) is configured to diagnose the state of the negative electrode based on diagnostic factor values ​​sequentially acquired as the charging cycle or the discharging cycle is repeated.

[0072] In one embodiment, the diagnostic unit (140) may be configured to diagnose that degradation of the negative electrode is in progress when the diagnostic factor values ​​show a trend of increasing and then decreasing for a predetermined period of time as the charging cycle or the discharging cycle is repeated.

[0073] In addition, the diagnostic unit (140) may be configured to determine a maximum value among the diagnostic factor values, and to diagnose the state of the cathode as abnormal if another diagnostic factor value acquired after the time point of acquiring the diagnostic factor value corresponding to the determined maximum value is less than a predetermined first threshold value.

[0074] In addition, the diagnostic unit (140) may be configured to diagnose the state of the target battery as a dangerous state requiring discontinuation of use if another diagnostic factor value acquired after the time point of acquiring the diagnostic factor value corresponding to the maximum value is less than a predetermined second threshold value. In this case, the second threshold value may be determined to be a value less than the first threshold value.

[0075] In one embodiment, the battery diagnostic device (100) may further include a charge / discharge control unit (150).

[0076] In this case, the charge / discharge control unit (150) may be configured to control the voltage at full charge of the target battery and the current rate of the charge current or discharge current of the target battery and / or the discharge conditions of the target battery, according to the diagnosis result of the above-described diagnosis unit (140). For example, when the negative electrode of the target battery is diagnosed as being in an abnormal state, the charge / discharge control unit (140) may control a charge / discharge unit (not shown) that charges and discharges the target battery to lower the voltage at full charge of the target battery or reduce the current rate of the charge / discharge current.

[0077] In one embodiment, the battery diagnostic device (100) may further include an output unit (160).

[0078] In this case, the output unit (160) may be configured to output information regarding the battery diagnosis results through visual, auditory, or audiovisual means. To this end, the output unit (160) may be linked to a visual display device such as a display, a light-emitting diode, or the like, and an audio device such as a speaker, or may selectively include the visual display device and the audio device. For example, if the state of the negative electrode of the target battery is diagnosed as being abnormal or dangerous, the output unit (160) may be configured to output the diagnosis result or a predetermined alarm.

[0079] The battery profile generation unit (110), negative profile acquisition unit (120), diagnostic factor acquisition unit (130), diagnostic unit (140), charge / discharge control unit (150), and output unit (160) of the above-described battery diagnostic device (100) may be implemented as a combination of a processor and a program executed by the processor. The battery diagnostic device (100) may be implemented as a single processor, or as two or more processors that are interconnected.

[0080] In one embodiment, the battery diagnostic device (100) according to the present invention may be configured to be linked with various sensors, such as a voltage sensor (12a) that senses the voltage of the target battery, a current sensor (12b) that senses the charge / discharge current of the target battery, etc.

[0081] In addition, the battery diagnostic device (100) according to the present invention may be configured to interwork with a communication unit (14) that performs communication with another device located remotely. In this case, the communication unit (14) may be configured to receive data transmitted from a remote server or communication terminal via a wired / wireless communication network and transmit the data to the battery diagnostic device (100), or to transmit data generated by the battery diagnostic device (100) to another server or communication terminal. To this end, the communication unit (14) may include a communication modem that performs wired communication and / or wireless communication.

[0082] In addition, the battery diagnostic device (100) according to the present invention may be configured to be linked with a storage unit (16) capable of storing programs or data required for battery diagnosis. In this case, the storage unit (16) may include one or two or more types of recording media such as RAM, ROM, EEPROM, flash memory, registers, etc.

[0083] In another embodiment, the battery diagnostic device (100) according to the present invention may be configured to include one or two or more of the voltage sensor (12a), current sensor (12b), communication unit (14), and storage unit (16) described above.

[0084] FIGS. 3 to 10 are drawings illustrating a process for obtaining a negative electrode profile of a target battery according to one embodiment of the present invention.

[0085] First, Fig. 3 illustrates a reference positive electrode profile (Rp) and a reference negative electrode profile (Rn) corresponding to a predetermined reference battery profile (R). In Fig. 3, the horizontal axis represents capacity and the vertical axis represents voltage.

[0086] Figure 4 illustrates a battery profile (M) of a target battery. In Figure 4, the horizontal axis represents capacity and the vertical axis represents voltage.

[0087] The cathode profile acquisition unit (120) may be configured to compare the battery profile (M) with at least one combination profile. Here, the combination profile may be a result of combining an adjusted cathode profile and an adjusted anode profile based on each of the reference cathode profile (Rp) and the reference cathode profile (Rn) stored in the storage unit (16).

[0088] That is, when the reference battery profile (R) is the result of subtracting a portion of the reference cathode profile (Rn) from a portion of the reference anode profile (Rp), the combined profile can be said to be the result of subtracting a portion of the adjusted cathode profile from a portion of the adjusted anode profile.

[0089] The cathode profile acquisition unit (120) can generate at least one combination profile by directly adjusting the reference anode profile (Rp) and the reference cathode profile (Rn). Alternatively, at least one combination profile can be secured in advance based on the reference anode profile (Rp) and the reference cathode profile (Rn) and stored in the storage unit (16). In this case, the cathode profile acquisition unit (120) can acquire the combination profile from the storage unit (16).

[0090] The cathode profile acquisition unit (120) can generate multiple combination profiles from the reference cathode profile (Rp) and the reference positive profile (Rn) by repeating the adjustment procedure of adjusting each of the reference positive profile (Rp) and the reference negative profile (Rn) to several levels and then combining them. The combination profile may also be referred to as an 'adjusted reference battery profile'.

[0091] The negative profile acquisition unit (120) can select a combination profile among a plurality of combination profiles that has the smallest error with the battery profile (M).

[0092] Next, the negative profile acquisition unit (120) can determine the adjusted positive profile and the adjusted negative profile corresponding to the selected combination profile as the positive profile and negative profile representing the current state of the target battery. In the following, it is noted that the positive profile is the finally determined adjusted positive profile, and the negative profile is the finally determined adjusted positive profile.

[0093] 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.

[0094] According to this configuration of the present invention, various battery status information can be obtained based on the finally determined positive and negative electrode profiles. The finally determined positive and negative electrode profiles correspond to the combination profile that most closely resembles the battery profile. In other words, the combination profile generated by combining the finally determined positive and negative electrode profiles can be said to be nearly identical to the battery profile (M) in terms of shape, etc.

[0095] Therefore, according to the present invention, the positive electrode profile and negative electrode profile of the target battery can be obtained without disassembling the target battery.

[0096] If the target battery is a new battery, the positive and negative profiles of the target battery can be analyzed to diagnose whether a defect has occurred in the target battery and, if so, what type of defect it is.

[0097] Additionally, if the target battery is an already in-use battery, the positive and negative profiles of the target battery can be used to determine the extent to which the battery has deteriorated for each deterioration item.

[0098] Furthermore, according to the present invention, the positive electrode profile and the negative electrode profile of the battery can be obtained through a simple process. The present invention can be implemented even if only one reference positive electrode profile (Rp) and one reference negative electrode profile (Rn) are stored in the storage unit (16). That is, there is no need to store a plurality of reference positive electrode profiles (Rp) and / or a plurality of reference negative electrode profiles (Rn) in the storage unit (16). Accordingly, there is no need for the storage capacity of the storage unit (16) to be high, and there is no need to conduct numerous preliminary tests required to secure a plurality of reference positive electrode profiles (Rp) and / or a plurality of reference negative electrode profiles (Rn).

[0099] FIGS. 5 to 7 are drawings for reference in explaining an example of a procedure for generating a combination profile used for comparison with a battery profile (M) according to one embodiment of the present invention.

[0100] The process of generating a combination profile to be described with reference to FIGS. 5 to 7 is performed in the following order: a first process (see FIG. 5) of setting four points (positive participation start point, positive participation end point, negative participation start point, negative participation end point) to correspond to a voltage range of interest, a second process (see FIG. 6) of performing profile shifting, and a third process (see FIG. 7) of performing capacity scaling. That is, the process of generating a combination profile according to one embodiment of the present invention includes the first to third processes.

[0101] First, referring to FIG. 5, the reference anode profile (Rp) and the reference cathode profile (Rn) are the same as those shown in FIG. 3.

[0102] The cathode profile acquisition unit (120) determines the cathode participation start point (pi), the cathode participation end point (pf), the cathode participation start point (ni), and the cathode participation end point (nf) on the reference cathode profile (Rp) and the reference cathode profile (Rn).

[0103] Either the positive engagement initiation point (pi) or the negative engagement initiation point (ni) depends on the other.

[0104] For example, the cathode profile acquisition unit (120) may divide the cathode voltage range from the start point of the reference cathode profile (Rp) to the end point (or the second set voltage) 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 the cathode participation start point (pi). Each micro-voltage section may have a predetermined size (e.g., 0.01 V). Then, the cathode profile acquisition unit (120) may set a point on the reference cathode profile (Rn) that is smaller than the cathode participation start point (pi) by the first set voltage (e.g., 3 V) as the cathode participation start point (ni).

[0105] As another example, the cathode profile acquisition unit (120) may divide the cathode voltage range from the start point to the end point of the reference cathode 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 the cathode participation start point (ni). Then, the cathode profile acquisition unit (120) may search for a point that is greater than the cathode participation start point (ni) by a first set voltage from the reference anode profile (Rp), and set the searched point as the anode participation start point (pi).

[0106] Additionally, either the positive engagement end point (pf) or the negative engagement end point (nf) depends on the other.

[0107] For example, the cathode profile acquisition unit (120) may divide the voltage range from the second set voltage to the end point of the reference anode 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 anode participation end point (pf). Then, the cathode profile acquisition unit (120) may set the point on the reference cathode profile (Rn) that is smaller by the second set voltage (e.g., 4 V) than the anode participation end point (pf) as the cathode participation end point (nf).

[0108] As another example, the cathode profile acquisition unit (120) may divide the cathode voltage range from the start point to the end point of the reference cathode 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 cathode participation end point (nf). Then, the cathode profile acquisition unit (120) may search for a point that is larger than the cathode participation end point (nf) by a second set voltage from the reference anode profile (Rp), and set the searched point as the anode participation end point (pf).

[0109] In this way, 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, the negative profile acquisition unit (120) shifts at least one of the reference positive profile (Rp) and the reference negative profile (Rn) to the left or right along the horizontal axis (capacity axis).

[0110] Referring to FIG. 6, the cathode profile acquisition unit (120) can shift the reference cathode profile (Rp) and / or the reference cathode profile (Rn) so that the capacity values ​​of the cathode participation start point (pi) and the cathode participation start point (ni) match.

[0111] Alternatively, the cathode profile acquisition unit (120) can shift the reference anode profile (Rp) and / or the reference cathode profile (Rn) so that the voltages of the anode engagement end point (pf) and the cathode engagement end point (nf) are identical.

[0112] In Fig. 6, the reference anode profile (Rp) is shifted to the left to generate an adjusted reference anode profile (Rp'), which results in the voltage of the anode engagement initiation point (pi') matching the voltage of the cathode engagement initiation point (ni). The adjusted reference anode profile (Rp') is the result of applying an adjustment procedure to the reference anode profile (Rp) that shifts it to the left by the voltage difference between the anode engagement initiation point (pi) and the cathode engagement initiation 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.

[0113] When the adjustment result profiles (Rp', Rn) in which at least one of the reference positive profile (Rp) and the reference negative profile (Rn) is shifted are obtained, the negative profile acquisition unit (120) scales the capacity range of at least one of the adjustment result profiles (Rp', Rn).

[0114] According to the example illustrated in FIG. 6, the cathode profile acquisition unit (120) performs an additional adjustment procedure to contract or expand at least one of the adjusted reference cathode profile (Rp') and the reference cathode profile (Rn) along the horizontal axis (capacity axis).

[0115] Referring to FIG. 7, the negative profile acquisition unit (120) can generate an adjusted reference positive electrode profile (Rp') by shrinking or expanding the adjusted reference positive electrode profile (Rp') so that the size of the capacity range between two points (pi', pf') of the adjusted reference positive electrode 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 reference positive electrode profile (Rp'') can match the size of the capacity range of the battery profile (M).

[0116] In addition, the negative profile acquisition unit (120) can generate an adjusted reference negative profile (Rn') by shrinking or expanding the reference negative profile (Rn) so that the size of the capacity range between two points (ni, nf) of the reference negative 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 reference negative profile (Rn') can match the capacity range of the battery profile (M).

[0117] In Fig. 7, the adjusted reference anode profile (Rp'') is a result of shrinking the adjusted reference anode profile (Rp') shown in Fig. 6, and the adjusted reference cathode profile (Rn') is a result of expanding the reference cathode profile (Rn) shown in Fig. 6.

[0118] The positive participation endpoint (pf'') on the adjusted reference positive profile (Rp'') corresponds to the positive participation endpoint (pf) on the adjusted reference positive profile (Rp'). The negative participation endpoint (nf') on the adjusted reference negative profile (Rn') corresponds to the negative participation endpoint (nf) on the reference negative profile (Rn).

[0119] The capacity difference between the positive engagement start point (pi') and the positive engagement end point (pf'') of the adjusted reference positive 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 reference negative profile (Rn') corresponds to the size of the capacity range of the battery profile (M).

[0120] In addition, the capacity difference between the two points (pi', pf'') of the adjusted reference anode profile (Rp'') matches the capacity difference between the two points (ni, nf') of the adjusted reference cathode profile (Rn'). The cathode profile acquisition unit (120) can generate a combined profile (S) by subtracting the part between the two points (ni, nf') of the adjusted reference cathode profile (Rn') from the part between the two points (pi', pf'') of the adjusted reference anode profile (Rp'').

[0121] The cathode profile acquisition unit (120) can calculate an error (profile error) between the combination profile (S) and the battery profile (M). When the error between the combination profile (S) and the battery profile (M) is minimized, the adjusted reference cathode profile (Rp'') corresponding to the combination profile (S) can be determined as the adjusted cathode profile, and the adjusted reference cathode profile (Rn') can be determined as the adjusted cathode profile.

[0122] The cathode profile acquisition unit (120) can record in the storage unit (16) at least two of the adjusted reference cathode profile (Rp''), the adjusted reference cathode profile (Rn'), the cathode participation start point (pi'), the cathode participation end point (pf''), the cathode participation start point (ni), the cathode participation end point (nf'), the first scale factor, the second scale factor, the combined profile (S), and the profile error by mutually mapping them. Here, the first scale factor can represent the ratio of the capacity difference between the two points (pi', pf'') to the capacity difference between the two points (pi0, pf0). The second scale factor can represent the ratio of the capacity difference between the two points (ni, nf') to the capacity difference between the two points (ni0, nf0).

[0123] In addition, the cathode profile acquisition unit (120) can calculate the cathode shrinkage ratio (ps) of the adjusted reference cathode profile (Rp'') with respect to the reference cathode profile (Rp). And, the cathode profile acquisition unit (120) can calculate the cathode shrinkage ratio (ns) of the adjusted reference cathode profile (Rn') with respect to the reference cathode profile (Rn). In this case, the cathode profile acquisition unit (120) can determine the first scale factor as the cathode shrinkage ratio (ps) and the second scale factor as the cathode shrinkage ratio (ns).

[0124] Meanwhile, as described above, when the anode voltage range of the reference anode 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).

[0125] For example, if the anode voltage range of the reference anode 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 reference anode 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 combination profiles can be generated.

[0126] Of course, those skilled in the art will easily understand that as the size of the micro-voltage section decreases, the maximum number of combination profiles that can be generated increases, and conversely, as the size of the micro-voltage section increases, the maximum number of combination profiles that can be generated decreases.

[0127] The cathode profile acquisition unit (120) can identify the minimum among the profile errors of the plurality of combined profiles generated as described above, and then acquire information mapped to the minimum profile error (e.g., at least one of the cathode participation start point (pi), the cathode participation end point (pf), the cathode participation start point (ni), the cathode participation end point (nf), the cathode shrinkage ratio (ps), the cathode shrinkage ratio (ns), and the capacity ratio between the cathode and the anode) from the storage unit (16).

[0128] FIGS. 8 to 10 are drawings for reference in explaining another embodiment of a procedure for generating a combination profile used for comparison with a battery profile (M) according to one embodiment of the present invention.

[0129] For reference, the embodiments according to FIGS. 8 to 10 are independent of the embodiments according to FIGS. 5 to 7. Therefore, terms or symbols commonly described 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.

[0130] The process of generating a combination profile to be described with reference to FIGS. 8 to 10 is performed in the following order: a fourth process (see FIG. 8) for performing capacity scaling, a fifth process (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 process (see FIG. 10) for performing profile shifting. That is, the process of generating a combination profile according to another embodiment of the present invention includes the fourth to sixth processes.

[0131] First, referring to Fig. 8, the reference anode profile (Rp) and the reference cathode profile (Rn) are the same as those shown in Fig. 3.

[0132] The cathode profile acquisition unit (120) applies a first scale factor and a second scale factor selected from a scaling value range to the reference cathode profile (Rp) and the reference anode profile (Rn), respectively, to generate an adjusted reference anode profile (Rp') and an adjusted reference cathode profile (Rn').

[0133] 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 reference battery 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 91×91=8,281 adjustment levels (combinations of the first scale factor and the second scale factor). An adjusted profile pair means a combination of an adjusted reference positive electrode profile and an adjusted reference negative electrode profile.

[0134] The adjusted reference anode profile (Rp') and the adjusted reference cathode profile (Rn') illustrated in FIG. 8 illustrate the results of applying a first scale factor and a second scale factor, each less than 100%, to the reference anode profile (Rp) and the reference cathode profile (Rn), respectively.

[0135] Since the first scale factor and the second scale factor are less than 100%, the adjusted reference anode profile (Rp') is the reference anode profile (Rp) shrunk along the horizontal axis, and the adjusted reference cathode profile (Rn') is also the reference cathode profile (Rn) shrunk along the horizontal axis. To facilitate understanding, the starting points of each of the anode profile (Rp) and the reference cathode profile (Rn) are fixed, and only the remaining portion is shrunk to the left along the horizontal axis.

[0136] Referring to FIG. 9, the cathode profile acquisition unit (120) determines the cathode participation start point (pi'), the cathode participation end point (pf'), the cathode participation start point (ni'), and the cathode participation end point (nf') on the adjusted reference cathode profile (Rp') and the adjusted reference cathode profile (Rn').

[0137] 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.

[0138] 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).

[0139] For example, the cathode profile acquisition unit (120) may divide the cathode voltage range from the start point to the end point (or the second set voltage) of the adjusted reference cathode 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 cathode participation start point (pi'). Then, the cathode profile acquisition unit (120) may set the point on the adjusted reference cathode profile (Rn) that is smaller by the first set voltage (e.g., 3 V) than the cathode participation start point (pi') as the cathode participation start point (ni').

[0140] As another example, the cathode profile acquisition unit (120) may divide the cathode voltage range from the start point to the end point of the adjusted reference cathode 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 cathode participation start point (ni'). Then, the cathode profile acquisition unit (120) may search for a point that is larger than the cathode participation start point (ni') by a first set voltage from the reference anode profile (Rp), and set the searched point as the anode participation start point (pi').

[0141] As another example, the cathode profile acquisition unit (120) may divide the voltage range from the second set voltage to the end point of the adjusted reference cathode 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 cathode participation end point (pf'). Then, the cathode profile acquisition unit (120) may search for a point in the adjusted reference cathode profile (Rn') that is smaller than the cathode participation end point (pf') by the second set voltage (e.g., 4 V), and set the searched point as the cathode participation end point (nf').

[0142] As another example, the cathode profile acquisition unit (120) may divide the cathode voltage range from the start point to the end point of the adjusted reference cathode 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 cathode participation end point (nf'). Then, the cathode profile acquisition unit (120) may search for a point that is larger than the cathode participation end point (nf') by a second set voltage from the adjusted reference anode profile (Rp'), and set the searched point as the anode participation end point (pf').

[0143] The cathode profile acquisition unit (120) can additionally determine the remaining three points based on the determined point when one of the cathode participation start point (pi'), the cathode participation end point (pf'), the cathode participation start point (ni'), and the cathode participation end point (nf') is determined.

[0144] For example, if the positive participation start point (pi') is first determined, the negative profile acquisition unit (120) may set a point on the adjusted reference positive 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'). In addition, the negative profile acquisition unit (120) may search for a point that is lower than the positive participation start point (pi') by a first set voltage from the adjusted reference negative profile (Rn') and set the searched point as the negative participation start point (ni'). In addition, the negative profile acquisition unit (120) may set a point on the adjusted reference negative 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').

[0145] As another example, when the positive participation end point (pf') is first determined, the negative profile acquisition unit (120) may set a point on the adjusted reference positive profile (Rp') that has a capacity value 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 negative profile acquisition unit (120) may search for a point lower by a second set voltage than the positive participation end point (pf') from the adjusted reference negative profile (Rn') and set the searched point as the negative participation end point (nf'). In addition, the negative profile acquisition unit (120) may set a point on the adjusted reference negative profile (Rn') that has a capacity value 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').

[0146] As another example, when the negative participation start point (ni') is determined, the negative profile acquisition unit (120) may set a point on the adjusted reference negative 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 negative profile acquisition unit (120) may search for a point that is higher than the negative participation start point (ni') by a first set voltage from the adjusted reference positive profile (Rp') and set the searched point as the positive participation start point (pi'). In addition, the negative profile acquisition unit (120) may set a point on the adjusted reference positive 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').

[0147] As another example, when the negative participation end point (nf') is determined, the negative profile acquisition unit (120) may set a point on the adjusted reference negative profile (Rn') that has a capacity value 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 negative profile acquisition unit (120) may search for a point higher by a second set voltage than the negative participation end point (nf') from the adjusted reference positive profile (Rp') and set the searched point as the positive participation end point (pf'). In addition, the negative profile acquisition unit (120) may set a point on the adjusted reference positive profile (Rp') that has a capacity value 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').

[0148] When the determination of the positive engagement start point (pi'), the positive engagement end point (pf'), the negative engagement start point (ni'), and the negative engagement end point (nf') is completed based on the pair of the first scale factor and the second scale factor, the negative profile acquisition unit (120) can shift at least one of the adjusted reference positive profile (Rp') and the adjusted reference negative profile (Rn') along the horizontal axis so that the capacity values ​​of the positive engagement start point (pi') and the negative engagement start point (ni') match, or so that the capacity values ​​of the positive engagement end point (pf') and the negative engagement end point (nf') match.

[0149] The adjusted reference cathode profile (Rn'') illustrated in Fig. 10 is only the adjusted reference cathode 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.

[0150] Referring to FIG. 10, the cathode profile acquisition unit (120) can generate a combined profile (U) by subtracting the partial profile between two points (pi', pf') of the adjusted reference cathode profile (Rn'') from the partial profile between two points (ni'', nf'') of the adjusted reference cathode profile (Rn'').

[0151] The cathode profile acquisition unit (120) can calculate an error (profile error) between the combination profile (U) and the battery profile (M). When the error between the combination profile (U) and the battery profile (M) is minimized, the adjusted reference cathode profile (Rp') corresponding to the combination profile (U) can be determined as the adjusted cathode profile, and the adjusted reference cathode profile (Rn'') can be determined as the adjusted cathode profile.

[0152] The cathode profile acquisition unit (120) can record in a storage unit (16) at least two of the adjusted reference cathode profile (Rp'), the adjusted reference cathode profile (Rn''), the anode participation start point (pi'), the anode participation end point (pf'), the cathode participation start point (ni''), the cathode participation end point (nf''), the anode shrinkage ratio (ps), the cathode shrinkage ratio (ns), the combined profile (U), and the profile error by mutually mapping them.

[0153] Here, the cathode profile acquisition unit (120) can calculate the cathode shrinkage ratio (ps) of the adjusted reference anode profile (Rp') with respect to the reference anode profile (Rp). In addition, the cathode profile acquisition unit (120) can calculate the cathode shrinkage ratio (ns) of the adjusted reference anode profile (Rn'') with respect to the reference cathode profile (Rn). For example, the cathode profile acquisition unit (120) can determine the first scale factor as the anode shrinkage ratio (ps) and the second scale factor as the cathode shrinkage ratio (ns).

[0154] Fig. 11 is a flowchart illustrating a battery diagnosis method according to one embodiment of the present invention.

[0155] As illustrated in FIG. 11, a battery diagnosis method according to the present invention is a method for non-destructively diagnosing a target battery having a negative electrode to which an active material that undergoes phase transformation as charging and discharging proceeds, and can be performed by a processor.

[0156] First, the processor measures voltage values ​​according to the capacity of the target battery using a voltage sensor (14a) while a predetermined number of charge cycles or discharge cycles are in progress (S10).

[0157] The processor then generates the battery profile based on the measured voltage values ​​(S20). For reference, the current capacity of the target battery can be calculated by applying a current integration method to the target battery's charging or discharging current. To this end, the processor can be linked to a current sensor (12b) that senses the target battery's charging or discharging current.

[0158] Next, the processor obtains a negative electrode profile that estimates the relationship between the negative electrode capacity and the negative electrode potential of the target battery based on the battery profile (S30).

[0159] In this case, the processor can generate a plurality of adjusted positive electrode profiles that are adjusted differently from each other and a plurality of adjusted negative electrode profiles that are adjusted differently from each other by adjusting a reference positive electrode profile that represents the relationship between the positive electrode capacity and the positive electrode potential of a given reference battery and a reference negative electrode profile that represents the relationship between the negative electrode capacity and the negative electrode potential of the reference battery, respectively. For reference, the reference battery may be a target battery at the beginning of life (BOL) point in time or a battery in a normal state with the same configuration as the target battery.

[0160] And the processor can select an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the battery profile from among the plurality of adjusted positive electrode profiles and the plurality of adjusted negative electrode profiles, and obtain the selected adjusted negative electrode profile as the negative electrode profile of the target battery.

[0161] Next, the processor obtains and stores a diagnostic factor value indicating the available capacity per unit area of ​​the cathode based on the cathode profile (S40).

[0162] In this case, the processor may be configured to calculate the diagnostic factor value based on a predetermined reference value for the diagnostic factor and a negative electrode shrinkage ratio indicating the degree to which the negative electrode profile has shrunk compared to a reference negative electrode profile indicating the relationship between the negative electrode capacity and the negative electrode potential of the reference battery. For example, the processor may calculate the diagnostic factor value by applying the above-described mathematical expression 1.

[0163] Next, the processor diagnoses the state of the cathode based on diagnostic factor values ​​sequentially acquired as the charging cycle or the discharging cycle is repeated (S50).

[0164] In one embodiment, the processor can diagnose that degradation of the negative electrode is in progress when the diagnostic factor values ​​show a trend of increasing and then decreasing for a predetermined period of time as the charging cycle or the discharging cycle is repeated.

[0165] In addition, the processor may be configured to determine a maximum value among the diagnostic factor values, and to diagnose the state of the cathode as abnormal if another diagnostic factor value acquired after the acquisition time of the diagnostic factor value corresponding to the determined maximum value is less than a predetermined first threshold value (S60).

[0166] Additionally, the processor may be configured to diagnose the state of the target battery as a dangerous state requiring discontinuation of use if another diagnostic factor value acquired after the time point of acquiring the diagnostic factor value corresponding to the maximum value is less than a predetermined second threshold value. In this case, the second threshold value may be determined to be a value less than the first threshold value.

[0167] Next, the processor, based on the diagnosis result of the target battery, adjusts the charging conditions and / or discharging conditions of the target battery, such as the voltage at full charge of the target battery and the current rate of the charging current or discharging current of the target battery (S70). For example, if the negative electrode of the target battery is diagnosed as being in an abnormal state, the processor can control a charging / discharging unit (not shown) that charges / discharges the target battery to lower the voltage at full charge of the target battery or reduce the current rate of the charging / discharging current.

[0168] In one embodiment, the processor may output information regarding the diagnostic results of the target battery through visual, auditory, or audiovisual means. To this end, the processor may be linked to a visual display device, such as a display or light-emitting diode, and / or an audio device, such as a speaker. For example, if the condition of the negative electrode of the target battery is diagnosed as abnormal or dangerous, the processor may output the diagnostic results or a predetermined alarm.

[0169] The above processor can repeat the above-described steps (S10 to S70) until the use of the target battery is stopped (S80).

[0170] FIG. 12 is a drawing showing a battery pack (10) according to one embodiment of the present invention.

[0171] As illustrated in FIG. 12, the battery pack (10) includes a rechargeable battery (B) and a battery diagnostic device (100) according to the present invention. In one embodiment, the battery pack (10) may optionally further include a measuring unit (12), a communication unit (14), a storage unit (16), and a charging / discharging unit (18).

[0172] The above measurement unit (12) may be configured to measure the voltage and / or current of the battery (B). To this end, the measurement unit (12) may include a voltage sensor (12a) and a current sensor (12b) described with reference to FIG. 1.

[0173] This measuring unit (12) can measure the voltage of the battery (B) through the first sensing line (SL1) and the second sensing line (SL2). In addition, the measuring unit (12) can measure the current of the battery (B) through the third sensing line (SL3) connected to the current measuring circuit (A). The current measuring circuit (A) may include a shunt resistor.

[0174] A battery diagnostic device (100) according to one embodiment of the present invention can obtain voltage values ​​of a battery (B) through the measuring unit (12).

[0175] The above communication unit (14) may be configured to perform communication with another device located remotely. For example, the communication unit (14) may be configured to receive data transmitted from a remote server or communication terminal via a wired and / or wireless communication network and transmit the data to the battery diagnosis device (100), or to transmit data generated in the battery diagnosis device (100) to another server or communication terminal. To this end, the communication unit (14) may include a communication modem that performs wired and / or wireless communication.

[0176] The above storage unit (16) may be configured to store programs or data required for battery diagnosis. In this case, the storage unit (16) may include one or more of various types of recording media, such as RAM, ROM, EEPROM, flash memory, registers, etc.

[0177] The above charging and discharging unit (18) may be configured to charge and / or discharge the battery (B). To this end, the charging and discharging unit (18) may include a charger for charging the battery (B), a discharger for discharging the battery (B), at least one switch for electrically connecting the battery (B) to terminals (T1, T2) of the battery pack (10), etc.

[0178] The battery diagnostic standby (100) according to one embodiment of the present invention can control the charging / discharging unit (18) to proceed or stop charging or discharging of the battery (B), set charging / discharging conditions, or change the set charging / discharging conditions.

[0179] Fig. 13 is a drawing showing a vehicle (2) according to one embodiment of the present invention.

[0180] As illustrated in FIG. 13, a vehicle (2) according to one embodiment of the present invention may include a battery pack (10) that provides electric energy required for the operation of the vehicle, and a battery diagnostic device (100) according to the present invention.

[0181] In this case, the battery diagnostic device (100) may be configured to be linked with an ECU (Electronic Control Unit) that controls the operation of the vehicle (2) or a BMS (Battery Management System) of the battery pack (10).

[0182] Additionally, the battery diagnostic device (100) may be configured to receive data transmitted from a remote server (4) via a wired and / or wireless communication network, or to transmit data generated in the battery diagnostic device (100) to the server (4).

[0183] For reference, the battery diagnostic device (100) according to the present invention can be applied to various electrical devices or electrical systems other than vehicles, and can also be applied to ESS (Energy Storage System).

[0184] As described above, according to the present invention, the battery diagnosis device is configured to generate a battery profile indicating a relationship between the capacity and voltage of the target battery for each predetermined number of charge cycles or discharge cycles, obtain a cathode profile estimating a relationship between the cathode capacity and cathode potential of the target battery based on the generated battery profile, and diagnose the state of the cathode of the target battery based on diagnostic factor values ​​obtained from the cathode profile, so that even when an active material that undergoes phase transformation, such as pure silicon, is applied to the cathode of the target battery, the state of the cathode can be diagnosed separately from the state of the cathode of the target battery.

[0185] In addition, the battery diagnostic device is configured to accurately diagnose the degree of activation or deterioration of the negative electrode of the target battery and adjust the charging and / or discharging conditions of the target battery according to the diagnosis result, thereby delaying the deterioration of the negative electrode of the target battery and extending its lifespan.

[0186] Furthermore, it goes without saying that embodiments according to the present invention can solve various technical problems other than those mentioned in the present specification, not only in the relevant technical field but also in related technical fields.

[0187] The present invention has been described with reference to specific embodiments. However, those skilled in the art will clearly understand that various modifications can be implemented within the technical scope of the present invention. Therefore, the embodiments disclosed above should be considered illustrative rather than limiting. In other words, the true scope of the present invention is set forth in the claims, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

[0188] [Explanation of symbols]

[0189] 2: Vehicle

[0190] 10: Battery pack

[0191] 100: Battery Diagnostic Device

[0192] 110: Battery profile generation unit

[0193] 120: Negative profile acquisition unit

[0194] 130: Diagnostic factor acquisition unit

[0195] 140: Diagnostic Department

[0196] 150: Charge / discharge control unit

[0197] 160: Output section

Claims

1. A battery diagnosis method for diagnosing a target battery having a negative electrode to which an active material that undergoes phase transformation as charging and discharging proceeds is applied. A step of generating a battery profile showing the relationship between the capacity and voltage of the target battery for each predetermined number of charge cycles or discharge cycles; A step of obtaining a negative electrode profile that estimates the relationship between the negative electrode capacity and negative electrode potential of the target battery based on the above battery profile; A step of obtaining a diagnostic factor value representing the available capacity per unit area of the cathode based on the cathode profile; and A battery diagnosis method comprising a step of diagnosing the state of the negative electrode based on diagnostic factor values sequentially acquired as the charging cycle or the discharging cycle is repeated.

2. In paragraph 1, Before the step of creating the above battery profile, A battery diagnosis method, characterized in that it further comprises a step of measuring the voltage value of the target battery using a voltage sensor while the predetermined number of charge cycles or discharge cycles are in progress.

3. In paragraph 1, Before the step of obtaining the above negative profile, Further comprising a step of generating a plurality of differently adjusted positive electrode profiles and a plurality of differently adjusted negative electrode profiles by adjusting a reference positive electrode profile representing a relationship between a positive electrode capacity and a positive electrode potential of a given reference battery and a reference negative electrode profile representing a relationship between a negative electrode capacity and a negative electrode potential of the reference battery, respectively. A battery diagnosis method characterized in that the step of obtaining the negative profile includes the step of selecting an adjusted positive profile and an adjusted negative profile corresponding to the battery profile from among the plurality of adjusted positive profiles and the plurality of adjusted negative profiles, and obtaining the selected adjusted negative profile as the negative profile of the target battery.

4. In paragraph 1, The step of obtaining the above diagnostic factor value is: A battery diagnosis method characterized by comprising a step of calculating a diagnosis factor value based on a cathode shrinkage ratio indicating the degree to which the cathode profile has shrunk compared to a reference cathode profile indicating the relationship between the cathode capacity and the cathode potential of a given reference battery, and a predetermined reference value for the diagnosis factor.

5. In paragraph 1, The step of diagnosing the state of the above cathode is: A battery diagnosis method characterized by including a step of diagnosing that degradation of the negative electrode is in progress when the diagnostic factor values increase and then decrease for a predetermined period of time as the charging cycle or the discharging cycle is repeated.

6. In paragraph 1, The step of diagnosing the state of the above cathode is: A step of determining the maximum value among the above diagnostic factor values; and A battery diagnosis method characterized by including a step of diagnosing the state of the negative electrode as abnormal if another diagnostic factor value acquired after the time point of acquiring the diagnostic factor value corresponding to the maximum value is smaller than a predetermined threshold value.

7. In paragraph 1, After the step of diagnosing the state of the above cathode, A battery diagnosis method characterized in that it further includes a step of adjusting the charging condition or the discharging condition of the target battery according to the diagnosis result of the state of the negative electrode.

8. In any one of paragraphs 1 to 7, A battery diagnostic method, characterized in that the above active material is silicon.

9. A battery diagnostic device that diagnoses a target battery having a negative electrode to which an active material is applied that undergoes phase transformation as charge and discharge are repeated. A battery profile generation unit that generates a battery profile indicating the relationship between the capacity and voltage of the target battery for each predetermined number of charge or discharge cycles; A cathode profile acquisition unit that acquires a cathode profile by estimating the relationship between the cathode capacity and cathode potential of the target battery based on the above battery profile; A diagnostic factor acquisition unit that acquires a diagnostic factor value representing the available capacity per unit area of the cathode based on the cathode profile; and A battery diagnostic device including a diagnostic unit that diagnoses the state of the negative electrode based on diagnostic factor values sequentially acquired by the diagnostic factor acquisition unit as the charging cycle or the discharging cycle is repeated.

10. In paragraph 9, The above negative profile acquisition unit, A first module that adjusts a reference positive electrode profile representing a relationship between a positive electrode capacity and a positive electrode potential of a given reference battery, and a reference negative electrode profile representing a relationship between a negative electrode capacity and a negative electrode potential of the reference battery, respectively, to generate a plurality of adjusted positive electrode profiles that are adjusted differently from each other and a plurality of adjusted negative electrode profiles that are adjusted differently from each other; and A battery diagnostic device characterized in that it includes a second module for selecting an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the battery profile from among the plurality of adjusted positive electrode profiles and the plurality of adjusted negative electrode profiles, and obtaining the selected adjusted negative electrode profile as the negative electrode profile of the target battery.

11. In paragraph 9, A battery diagnostic device characterized in that the diagnostic unit is configured to diagnose that degradation of the negative electrode is in progress when the diagnostic factor values increase and then decrease for a predetermined period of time as the charging cycle or the discharging cycle is repeated.

12. In paragraph 9, A battery diagnostic device characterized in that the diagnostic unit is configured to diagnose the state of the negative electrode as abnormal if another diagnostic factor value acquired after the time point of acquiring the diagnostic factor value corresponding to the maximum value among the diagnostic factor values is less than a predetermined threshold value.

13. A battery pack comprising a battery diagnostic device according to any one of claims 9 to 12.

14. A vehicle including a battery diagnostic device according to any one of paragraphs 9 to 12.

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