Battery diagnostic device and method

Abstract

A battery diagnostic device according to one embodiment of the present invention includes: a profile determination unit that determines the positive electrode profile of a battery by adjusting a reference positive electrode profile and a reference negative electrode profile to fit a measurement full cell profile showing the correspondence between battery capacity and voltage; a load amount calculation unit that calculates the positive electrode load amount of a battery based on the positive electrode profile of a battery; and a condition diagnosis unit that compares the resistance of a battery with a preset resistance range, compares the positive electrode load amount of a battery with a preset load amount range, and diagnoses the state of the battery based on the resistance comparison result and the positive electrode load amount comparison result.

Description

Technical Field

[0001] The present invention relates to a battery diagnosis device and method, and more particularly, to a battery diagnosis device and method capable of diagnosing whether any one or more of an active material, a conductive material, and a binder are excessively, insufficiently, or appropriately introduced into a positive electrode of a battery.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0126639 filed on September 21, 2023, and all the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] In recent years, the demand for portable electronic products such as notebook PCs (Personal Computers), video cameras, and mobile phones has increased rapidly. As the development of electric vehicles, energy storage batteries, robots, satellites, etc. has become full-scale, research on high-performance batteries that can be repeatedly charged and discharged has been actively conducted.

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

[0005] Battery electrodes are manufactured by coating current collector plates with a slurry containing an active material, a conductive material, and a binder. The active material is a substance that generates electrical energy through chemical reactions. For example, in a lithium battery, the positive electrode active material provides lithium ions to the negative electrode during charging, and the negative electrode active material stores and releases lithium ions during discharge. Thus, the active material affects the battery's capacity and output. The conductive material is a substance that improves the electrical conductivity between active material particles or between active material particles and metal current collectors. The binder is a substance that maintains the bonding force between the active material and the conductive material, and mechanically stabilizes the electrodes.

[0006] Therefore, the composition ratio of active material, conductive material, and binder is a crucial factor in determining battery performance.

[0007] However, due to manufacturing process issues, the composition ratios of active material, conductive material, and binder may differ from the designed ratios. When the composition ratios of active material, conductive material, and binder differ from the designed ratios, the battery performance may also differ from the designed performance. In other words, in order to supply batteries with uniform performance, it is necessary to diagnose whether the composition ratios of active material, conductive material, and binder in the manufactured batteries match the designed ratios.

[0008] However, once a battery is manufactured, it is virtually impossible to accurately measure the composition ratio of the active material, conductive material, and binder without disassembling it and directly analyzing the electrodes. Therefore, there is a need for a technology that can non-destructively diagnose whether the composition ratio of the active material, conductive material, and binder in a manufactured battery matches the design ratio without disassembling the battery. In other words, there is a need for a technology that can diagnose whether one or more of the active material, conductive material, and binder have been added in excess, insufficient, or appropriate amounts to the positive electrode. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention has been made in view of the above-mentioned problems, and aims to provide a battery diagnostic device and method that can non-destructively, simply, and accurately diagnose whether one or more of the active material, conductive material, and binder have been added to the positive electrode of a battery in an excessive amount, in an insufficient amount, or in an appropriate amount.

[0010] Other objects and advantages of the present invention can be understood from the following description and will be more clearly understood from the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by the means and combinations thereof shown in the claims. [Means for solving the problem]

[0011] A battery diagnostic device according to one aspect of the present invention may include: a profile determination unit configured to determine the positive electrode profile of a battery by adjusting a reference positive electrode profile and a reference negative electrode profile to fit a measurement full cell profile showing the correspondence between battery capacity and voltage; a load amount calculation unit configured to calculate the positive electrode load amount of a battery based on the positive electrode profile of a battery; and a condition diagnosis unit configured to compare the resistance of a battery with a preset resistance range, compare the positive electrode load amount of a battery with a preset load amount range, and diagnose the state of the battery based on the resistance comparison result and the positive electrode load amount comparison result.

[0012] The status diagnosis unit may be configured to diagnose the battery state as normal when the resistance is within the resistance range and the positive electrode load amount is within the load amount range, and to diagnose the battery state as abnormal when the resistance is outside the resistance range or the positive electrode load amount is outside the load amount range.

[0013] An abnormal condition may be one in which at least one of the active material, binder, and conductive material is overfilled into the positive electrode of the battery.

[0014] The load amount calculation unit may be configured to calculate the positive electrode load amount by considering the positive electrode change ratio of the battery's positive electrode profile relative to the reference positive electrode profile.

[0015] The load amount calculation unit may be configured to calculate the positive electrode load amount considering the positive electrode change ratio, a preset reference positive electrode capacity, and a preset reference area.

[0016] The load amount calculation unit can be configured to calculate the positive electrode load amount, which represents the positive electrode capacity per unit area, by multiplying the reference positive electrode capacity by the positive electrode change ratio and dividing the result by the reference area.

[0017] The resistance range may be a range set based on the standard deviation of the resistance distribution, with the average of the resistance distributions of multiple reference batteries as the reference.

[0018] The load range may be a range set based on the standard deviation of the load distribution, with the average of the positive electrode load distributions of multiple reference batteries as the reference.

[0019] Furthermore, a battery diagnostic device according to another aspect of the present invention may further include a resistance calculation unit configured to calculate the battery resistance based on the measured full cell profile.

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

[0021] A battery pack according to yet another aspect of the present invention may include a battery diagnostic device according to one aspect of the present invention.

[0022] According to another aspect of the present invention, a battery diagnosis method may include a positive electrode profile determination step of determining a positive electrode profile of a battery by adjusting a reference positive electrode profile and a reference negative electrode profile so as to fit a measurement full cell profile indicating a correspondence relationship between the capacity and voltage of the battery, a positive electrode load amount calculation step of calculating a positive electrode load amount of the battery based on the positive electrode profile of the battery, a comparison step of comparing the resistance of the battery with a preset resistance range and comparing the positive electrode load amount of the battery with a preset load amount range, and a state diagnosis step of diagnosing the state of the battery based on the resistance comparison result and the positive electrode load amount comparison result of the comparison step.

Advantages of the Invention

[0023] According to one aspect of the present invention, it is possible to non-destructively, simply and accurately diagnose whether any one or more of an active material, a conductive material, and a binder are overcharged, undercharged, or appropriately charged in the positive electrode of a battery.

[0024] Also, according to one aspect of the present invention, since the resistance of the battery and the positive electrode load amount are used to complementarily diagnose the battery state, the accuracy of battery state diagnosis is improved.

[0025] Also, according to one aspect of the present invention, based on the resistance comparison result and the positive electrode load amount comparison result, the state of the positive electrode can be subdivided and accurately diagnosed. In addition, since the state of the positive electrode is specifically diagnosed, the cause of problems in battery manufacturing can be quickly grasped.

[0026] Also, according to one aspect of the present invention, since the state of the battery is diagnosed considering the positive electrode capacity per unit area, the state of the battery can be consistently diagnosed regardless of the total amount of the positive electrode.

[0027] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0028] The following drawings accompanying this specification illustrate preferred embodiments of the invention and, together with the detailed description of the invention, serve to further illustrate the technical idea of ​​the invention. Therefore, the invention should not be construed as being limited solely to what is shown in the drawings. [Brief explanation of the drawing]

[0029] [Figure 1] This figure schematically shows a battery diagnostic device according to one embodiment of the present invention. [Figure 2] This table explains the loading conditions of the active material, conductive material, and binder based on the resistance comparison results and the positive electrode load comparison results. [Figure 3] This table explains the loading conditions of the active material, conductive material, and binder based on the resistance comparison results and the positive electrode load comparison results. [Figure 4] These graphs illustrate examples of both the reference positive electrode profile and the reference negative electrode profile. [Figure 5] This graph illustrates an example of a measured full cell profile of the target cell. [Figure 6] This figure illustrates an example of the process for generating a comparative full-cell profile used for comparison with a measured full-cell profile according to one embodiment of the present invention. [Figure 7] This figure illustrates an example of the process for generating a comparative full-cell profile used for comparison with a measured full-cell profile according to one embodiment of the present invention. [Figure 8] This figure illustrates an example of the process for generating a comparative full-cell profile used for comparison with a measured full-cell profile according to one embodiment of the present invention. [Figure 9] This figure illustrates another example of the process for generating a comparative full-cell profile used for comparison with a measured full-cell profile according to one embodiment of the present invention. [Figure 10]This figure illustrates another example of the process for generating a comparative full-cell profile used for comparison with a measured full-cell profile according to one embodiment of the present invention. [Figure 11] This figure illustrates another example of the process for generating a comparative full-cell profile used for comparison with a measured full-cell profile according to one embodiment of the present invention. [Figure 12] This figure shows an exemplary configuration of a battery pack including a battery diagnostic device according to one embodiment of the present invention. [Figure 13] This flowchart exemplifies a battery diagnostic method according to one embodiment of the present invention. [Modes for carrying out the invention]

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their usual or dictionary meanings, but rather in a manner appropriate to the technical idea of ​​the present invention, in accordance with the principle that the inventor himself may appropriately define the concept of terms in order to best describe the invention.

[0031] Therefore, the embodiments and configurations shown in the drawings described herein represent only one of the most preferred embodiments of the present invention and do not represent the entirety of the technical concept of the present invention. It should be understood that there are various equivalents and modifications that can be substituted for these at the time of filing this application.

[0032] In addition, when describing the present invention, if it is determined that a specific description of a related known configuration or function would unnecessarily obscure the gist of the present invention, such description will be omitted.

[0033] Terms that include ordinal numbers, such as "1st," "2nd," etc., are used to distinguish one of the various components from the rest, and such terms do not limit the components themselves.

[0034] Throughout the specification, when a part of it "includes" a certain component, unless otherwise specified, it means that other components are not excluded and may further include other components.

[0035] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly connected" through other elements in between.

[0036] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0037] Figure 1 is a schematic diagram showing a battery diagnostic device 100 according to one embodiment of the present invention.

[0038] Referring to Figure 1, a battery diagnostic device 100 according to one embodiment of the present invention may include a profile determination unit 110, a load amount calculation unit 120, and a state diagnosis unit 130. The battery diagnostic device 100 may further include a resistance calculation unit 140. The battery diagnostic device 100 may further include a storage unit 150.

[0039] Here, a battery refers to a single, independent cell that has a negative terminal and a positive terminal and is physically separable. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery.

[0040] The profile determination unit 110 may be configured to determine the battery's positive electrode profile by adjusting the reference positive electrode profile and the reference negative electrode profile to fit a measured full cell profile that shows the correspondence between the battery's capacity and voltage.

[0041] Here, the measured full-cell profile is a profile generated based on the capacity and voltage measured during the battery's charging or discharging process. For example, the measured full-cell profile may be a profile showing the correspondence between the capacity and voltage measured during the battery's charging process. That is, the measured full-cell profile may be the battery's capacity Q-voltage V profile.

[0042] A reference positive electrode profile may be a profile showing the correspondence between the capacity and voltage of a reference positive electrode cell pre-configured to correspond to the positive electrode of a battery. For example, the reference positive electrode cell may be a positive coin half cell or the positive electrode of a 3-electrode cell. Similarly, a reference negative electrode profile may be a profile showing the correspondence between the capacity and voltage of a reference negative electrode cell pre-configured to correspond to the negative electrode of a battery. For example, the reference negative electrode cell may be a negative coin half cell or the negative electrode of a 3-electrode cell.

[0043] Specifically, the profile determination unit 110 can adjust the reference positive electrode profile and the reference negative electrode profile to fit the measured full cell profile. More specifically, the profile determination unit 110 can adjust the reference positive electrode profile and the reference negative electrode profile to generate an adjusted positive electrode profile and an adjusted negative electrode profile. The profile determination unit 110 can then generate a comparison full cell profile from the adjusted positive electrode profile and the adjusted negative electrode profile. The profile determination unit 110 can adjust the reference positive electrode profile and the reference negative electrode profile until the comparison full cell profile fits the measured full cell profile.

[0044] For example, the profile determination unit 110 can generate multiple comparison full cell profiles by shifting the reference positive electrode profile and the reference negative electrode profile, or by performing capacity scaling, and then identify one of the multiple comparison full cell profiles that minimizes the error with the measured full cell profile.

[0045] In this regard, a more specific embodiment of how the profile determination unit 110 adjusts the reference positive electrode profile and reference negative electrode profile to fit the measured full cell profile and determines the positive electrode profile of the battery will be described later with reference to Figures 4 to 8.

[0046] The load amount calculation unit 120 may be configured to calculate the positive electrode load amount of the battery based on the positive electrode profile of the battery.

[0047] Here, the positive electrode load of the battery may refer to the amount of positive electrode active material coated on the positive electrode current collector. The positive electrode profile of the battery is generated from a reference positive electrode profile and may be a profile that indicates the current state of the battery's positive electrode. This allows the load amount calculation unit 120 to calculate the positive electrode load of the battery based on the positive electrode profile. A specific embodiment of how the load amount calculation unit 120 calculates the positive electrode load from the positive electrode profile will be described later.

[0048] The status diagnosis unit 130 may be configured to compare the battery resistance with a preset resistance range.

[0049] Here, the resistance range can be predetermined based on the resistance distribution of multiple reference batteries corresponding to the target battery. Preferably, the reference battery may be a battery whose type and specifications correspond to the battery being diagnosed by the battery diagnostic device 100 (hereinafter referred to as the "target battery").

[0050] For example, the resistance range may be set based on the mean and standard deviation of the resistance distribution of multiple reference batteries. Specifically, the resistance range may be set to a range of 3 standard deviations from the mean of the resistance distribution of multiple reference batteries. That is, the lower limit of the resistance range may be set as the mean minus 3 standard deviations, and the upper limit of the resistance range may be set as the mean plus 3 standard deviations.

[0051] The status diagnosis unit 130 can compare the battery's resistance with a preset resistance range to determine whether the battery's resistance falls within that range. For example, if the battery's resistance is less than or equal to the upper limit of the resistance range and greater than or equal to the lower limit, the status diagnosis unit 130 can determine that the battery's resistance falls within the resistance range. Conversely, if the battery's resistance exceeds the upper limit or falls below the lower limit of the resistance range, the status diagnosis unit 130 can determine that the battery's resistance does not fall within the resistance range.

[0052] The status diagnosis unit 130 may be configured to compare the positive electrode load of the battery with a preset load range.

[0053] Here, the load range can be predetermined based on the positive electrode load distribution of multiple reference batteries corresponding to the target battery.

[0054] For example, the load range may be a range set based on the mean and standard deviation of the positive electrode load distribution of multiple reference batteries. Specifically, the load range may be set to a range of 3 standard deviations from the mean of the positive electrode load distribution of multiple reference batteries. That is, the lower limit of the load range may be set to the mean minus 3 standard deviations, and the upper limit of the load range may be set to the mean plus 3 standard deviations.

[0055] The status diagnosis unit 130 can compare the positive electrode load amount of the battery with a preset load amount range to determine whether or not the positive electrode load amount of the battery falls within the preset load amount range. For example, if the positive electrode load amount of the battery is less than or equal to the upper limit of the load amount range and greater than or equal to the lower limit, the status diagnosis unit 130 can determine that the positive electrode load amount of the battery falls within the load amount range. Conversely, if the positive electrode load amount of the battery exceeds the upper limit of the load amount range or falls below the lower limit, the status diagnosis unit 130 can determine that the positive electrode load amount of the battery does not fall within the load amount range.

[0056] According to one embodiment, the resistance range may be set based on the resistance distribution of a plurality of reference batteries and the target battery. The load amount range may be set based on the positive electrode load amount distribution of a plurality of reference batteries and the target battery.

[0057] The status diagnosis unit 130 may be configured to diagnose the battery status based on the resistance comparison result and the positive electrode load comparison result.

[0058] Specifically, the status diagnosis unit 130 may be configured to diagnose the battery state as normal when the resistance falls within the resistance range and the positive electrode load falls within the load range. Conversely, the status diagnosis unit 130 may be configured to diagnose the battery state as abnormal when the resistance does not fall within the resistance range or the positive electrode load does not fall within the load range.

[0059] A battery diagnostic device 100 according to one embodiment of the present invention has the advantage of diagnosing the battery condition by considering both the battery resistance and the positive electrode load. In other words, with the battery diagnostic device 100, the battery resistance and the positive electrode load are used in a complementary manner to diagnose the battery condition, thus improving the accuracy of the battery condition diagnosis.

[0060] On the other hand, the profile determination unit 110, load amount calculation unit 120, state diagnosis unit 130, and resistance calculation unit 140 provided in the battery diagnostic device 100 may selectively include known processors, ASICs (application-specific integrated circuits), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., in order to execute the various control logics performed in the present invention. Furthermore, when the control logic is implemented as software, each component of the battery diagnostic device 100 may be implemented as a collection of program modules.

[0061] On the other hand, the battery diagnostic device 100 may further include a storage unit 150. The storage unit 150 may store data and programs necessary for each component of the battery diagnostic device 100 to operate and function, or data generated during the process of operation and functioning. The type of storage unit 150 is not particularly limited, as long as it is a known information storage means capable of recording, erasing, updating, and reading data. Examples of information storage means include RAM (Random Access Memory), flash memory (registered trademark), ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), and registers. The storage unit 150 may also store program code that defines the processes that can be executed by each component of the battery diagnostic device 100.

[0062] The condition diagnosis unit 130 can diagnose the battery's condition as normal or abnormal based on the resistance comparison result and the positive electrode load amount comparison result. Here, an abnormal condition may be a state in which at least one of the active material, conductive material, and binder is overfilled into the battery's positive electrode.

[0063] Typically, the positive electrode of a battery is manufactured by coating a current collector plate with a slurry containing a mixture of active material, conductive material, and binder. Therefore, a battery in an abnormal state may have an over-filled positive electrode with at least one of the active material, conductive material, and binder.

[0064] Figures 2 and 3 are diagrams illustrating the loading state of the active material, conductive material, and binder based on the resistance comparison results and positive electrode load comparison results.

[0065] Referring to Figure 2, the state in which the conductive material is inserted can be determined by the resistance comparison result, and the state in which the active material is inserted can be determined by the positive electrode load comparison result.

[0066] Specifically, the state diagnosis unit 130 can diagnose whether the conductive material is in an over-filled state, an under-filled state, or an appropriate amount based on the result of comparing the resistance with the resistance range. For example, if the resistance falls within the resistance range, the state diagnosis unit 130 can diagnose that the conductive material is in an appropriate amount. If the resistance exceeds the upper limit of the resistance range, the state diagnosis unit 130 can diagnose that the conductive material is in an over-filled state. If the resistance is below the lower limit of the resistance range, the state diagnosis unit 130 can diagnose that the conductive material is in an under-filled state.

[0067] Conductive materials are substances that improve the electronic conductivity between active material particles or between active material particles and metal current collectors. In other words, conductive materials are substances that allow current to flow well through the electrodes of a battery. Therefore, if the proportion of conductive material decreases relatively, the battery resistance increases, and if the proportion of conductive material increases relatively, the battery resistance decreases.

[0068] Specifically, the state diagnosis unit 130 can diagnose whether the active material is being overloaded, underloaded, or in the correct amount state based on a comparison of the positive electrode load amount with the load amount range. For example, if the positive electrode load amount falls within the load amount range, the state diagnosis unit 130 can diagnose that the active material is being in the correct amount state. If the positive electrode load amount exceeds the upper limit of the load amount range, the state diagnosis unit 130 can diagnose that the active material is being overloaded. If the positive electrode load amount is below the lower limit of the load amount range, the state diagnosis unit 130 can diagnose that the active material is being underloaded.

[0069] Active materials are substances that generate electrical energy through chemical reactions. For example, in a lithium battery, the positive electrode active material provides lithium ions to the negative electrode during charging, and the negative electrode active material stores and releases lithium ions during discharge. Therefore, the active material affects the battery's capacity and output. Specifically, the more positive electrode active material there is, the greater the positive electrode capacity. That is, the more positive electrode active material there is, the greater the positive electrode load, which is the positive electrode capacity per unit area.

[0070] Referring to Figure 3, the binder injection state can be indirectly determined by the injection state of the active material and the conductive material. That is, assuming that the amount of slurry mixed with the active material, conductive material, and binder is constant, the binder injection state can be determined by the injection state of the conductive material and the active material. For example, the state diagnosis unit 130 can diagnose the binder injection state as an over-injection state, an under-injection state, or an appropriate injection state.

[0071] There are a total of nine possible embodiments depending on the state in which the active material, conductive material, and binder are added. There is one embodiment in which the active material, conductive material, and binder are all added in appropriate amounts. There are a total of eight embodiments in which at least one of the active material, conductive material, and binder is added in an excessive or insufficient amount.

[0072] If the resistance exceeds the upper limit of the resistance range and the positive electrode load exceeds the upper limit of the load range, the state diagnosis unit 130 may diagnose that the conductive material is in a small amount state and the active material is in an over-fill state. The binder may then be in an over-fill state, a small amount state, or an appropriate amount state. Here, the binder filling state can be determined based on the amount of conductive material and the amount of active material.

[0073] If the resistance exceeds the upper limit of the resistance range and the positive electrode load is less than the lower limit of the load range, the state diagnosis unit 130 can diagnose that the conductive material is in a small amount state, the active material is in a small amount state, and the binder is in an over-load state.

[0074] If the resistance exceeds the upper limit of the resistance range and the positive electrode load falls within the load range, the state diagnosis unit 130 can diagnose that the conductive material is in a small amount state, the active material is in an appropriate amount state, and the binder is in an over-added state.

[0075] If the resistance is below the lower limit of the resistance range and the positive electrode load exceeds the upper limit of the load range, the state diagnosis unit 130 can diagnose that the conductive material is in an overload state, the active material is in an overload state, and the binder is in an underload state.

[0076] If the resistance is below the lower limit of the resistance range and the positive electrode load is below the lower limit of the load range, the state diagnosis unit 130 can diagnose that the conductive material is in an overload state and the active material is in an underload state. The binder may then be in an overload state, an underload state, or an appropriate load state. Here, the binder loading state can be determined based on the amount of conductive material and the amount of active material loaded.

[0077] If the resistance is below the lower limit of the resistance range and the positive electrode load falls within the load range, the state diagnosis unit 130 can diagnose that the conductive material is in an overload state, the active material is in an appropriate amount state, and the binder is in a small amount state.

[0078] If the resistance falls within the resistance range and the positive electrode load exceeds the upper limit of the load range, the state diagnosis unit 130 can diagnose that the conductive material is in an appropriate amount, the active material is in an over-filled state, and the binder is in a small amount.

[0079] If the resistance is within the resistance range and the positive electrode load is less than the lower limit of the load range, the state diagnosis unit 130 can diagnose that the conductive material is in the correct amount, the active material is in the small amount, and the binder is in the excessive amount.

[0080] The condition diagnosis unit 130 can diagnose that the active material, conductive material, and binder are in an appropriate amount state if the resistance is within the resistance range and the positive electrode load amount is within the load amount range.

[0081] A battery diagnostic device 100 according to one embodiment of the present invention has the advantage of being able to accurately diagnose the state of the positive electrode by subdividing it based on the resistance comparison results and the positive electrode load comparison results. Furthermore, because the state of the positive electrode is diagnosed in detail, the cause of manufacturing problems in the battery can be quickly identified.

[0082] The following describes in detail an embodiment in which the load amount calculation unit 120 calculates the positive electrode load amount from the positive electrode profile.

[0083] The load amount calculation unit 120 may be configured to calculate the positive electrode load amount by considering the positive electrode change ratio of the battery's positive electrode profile relative to the reference positive electrode profile.

[0084] Here, the positive electrode change percentage may mean the percentage change in the battery's positive electrode profile relative to the reference positive electrode profile. Specifically, the positive electrode change percentage may be the percentage contraction or expansion of the battery's positive electrode profile relative to the reference positive electrode profile.

[0085] For example, if the battery's positive electrode profile shrinks by 10% from the reference positive electrode profile, the positive electrode change rate can be said to be 90%. If the battery's positive electrode profile expands by 10% from the reference positive electrode profile, the positive electrode change rate will be 110%.

[0086] In other words, if the positive electrode change rate is less than 100%, the battery's positive electrode profile is generated by shrinking the reference positive electrode profile. If the positive electrode change rate is greater than 100%, the battery's positive electrode profile is generated by expanding the reference positive electrode profile. And if the positive electrode change rate is 100%, the battery's positive electrode profile is the reference positive electrode profile that has not been shrunk or expanded.

[0087] Specifically, the load amount calculation unit 120 may be configured to calculate the positive electrode load amount considering the positive electrode change ratio, a preset reference positive electrode capacity, and a preset reference area.

[0088] Here, the reference positive electrode capacity may refer to the capacity of a pre-set reference positive electrode cell. The reference area may refer to the area of ​​a pre-set reference positive electrode cell.

[0089] Specifically, the load amount calculation unit 120 can be configured to calculate the positive electrode load amount as the positive electrode capacity per unit area by multiplying the reference positive electrode capacity by the positive electrode change ratio and dividing the result by the reference area.

[0090] The positive electrode change ratio is the percentage by which the battery's positive electrode profile is changed relative to the reference positive electrode profile. Therefore, multiplying the reference positive electrode capacity by the positive electrode change ratio can calculate the battery's positive electrode capacity. Dividing the calculated battery's positive electrode capacity by the reference area allows us to calculate the positive electrode load, which indicates the positive electrode capacity per unit area of ​​the battery.

[0091] In other words, dividing the standard positive electrode capacity by the standard area can yield the standard positive electrode capacity per unit area. Multiplying the standard positive electrode capacity per unit area by the positive electrode change ratio can yield the positive electrode capacity per unit area of ​​the battery.

[0092] Specifically, the load amount calculation unit 120 can calculate the positive electrode load amount based on the positive electrode change ratio, reference positive electrode capacity, and reference area using the following formula 1.

[0093]

number

[0094] In the formula, P-loading represents the positive electrode load amount, and ps represents the positive electrode change rate. Q r This indicates the reference positive electrode capacity, A pc This indicates the standard area.

[0095] For example, if the area of ​​the battery is the same as the reference area, the battery area can be replaced with the reference area in the diagram.

[0096]

number

[0097] In the formula, A fc represents the area of ​​the battery. In equation 2, A fc is A pc Since it can be replaced by , Equation 1 can be derived from Equation 2. For example, the positive electrode load amount calculated by multiplying the reference positive electrode capacity by the positive electrode change ratio and dividing by the battery area may be the same as the positive electrode load amount calculated by Equation 1.

[0098] In other cases, if the battery area differs from the reference area, scaling adjustments for the area are necessary. Specifically, the value obtained by multiplying the reference positive electrode capacity by the positive electrode change ratio, dividing by the battery area, and then multiplying the result by the area ratio is used. Here, the area ratio can refer to the ratio of the battery area to the area of ​​the reference positive electrode cell. For example, the area ratio can be calculated as the ratio of the battery area to the reference area.

[0099] For example, the load amount calculation unit 120 can calculate the positive electrode load amount when the battery area differs from the standard area using the following formula 3.

[0100]

number

[0101] In equation 3, A fc When this is erased, equation 1 can be derived as a result. That is, the positive electrode capacity per unit area (positive electrode load, P-loading) can be calculated using equation 1, both when the battery area is the same as the reference area and when it is not the same.

[0102] The battery diagnostic device 100 has the advantage of being able to consistently diagnose the battery condition regardless of the total positive electrode capacity, because it diagnoses the battery condition by taking into account the positive electrode capacity per unit area.

[0103] A battery diagnostic device 100 according to one embodiment of the present invention may further include a resistance calculation unit 140 configured to calculate the resistance of a battery based on a measured full cell profile M.

[0104] Specifically, the resistance calculation unit 140 may be configured to calculate the battery resistance by calculating the voltage difference between the first voltage at the first time point and the second voltage at the second time point, and the ratio of the amount of current from the first time point to the second time point. Here, the first time point and the second time point are different time points.

[0105] For example, if the second time point is 10 seconds after the first time point, the resistance calculated by the resistance calculation unit 140 may be the 10-second resistance R10 of the battery. That is, the resistance calculation unit 140 can calculate the battery's resistance based on the voltage change over a predetermined time (e.g., 10 seconds).

[0106] Typically, the resistance of a battery can be calculated using Ohm's law, which expresses the resistance as the ratio of the voltage to the current. Therefore, the resistance calculation unit 140 can calculate the battery's resistance by performing the calculation using the formula "(second voltage - first voltage) ÷ current".

[0107] The following describes a specific embodiment in which the profile determination unit 110 adjusts the reference positive electrode profile and reference negative electrode profile to fit the measured full cell profile in order to determine the positive electrode profile of the battery.

[0108] Figure 4 is a graph illustrating an example of a reference positive electrode profile Rp and a reference negative electrode profile Rn. In the graph in Figure 4, the horizontal axis (X axis) represents capacitance (Ah), and the vertical axis (Y axis) represents voltage (V).

[0109] Figure 5 is a graph referenced to illustrate an example of a measured full cell profile M of the target cell. In the graph of Figure 5, the horizontal axis (X axis) represents capacity (Ah), and the vertical axis (Y axis) represents voltage (V).

[0110] The profile determination unit 110 may be configured to compare the measured full cell profile M with at least one comparison full cell profile. Here, the comparison full cell profile may be the result of generating an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting the reference positive electrode profile Rp and the reference negative electrode profile Rn stored in the storage unit 150, and then combining (combining) the adjusted positive electrode profile and the adjusted negative electrode profile.

[0111] In other words, if the reference full cell profile R is the result of subtracting a portion of the reference negative electrode profile Rn from a portion of the reference positive electrode profile Rp, then the comparative full cell profile can be said to be the result of subtracting a portion of the adjusted negative electrode profile from a portion of the adjusted positive electrode profile.

[0112] The profile determination unit 110 can generate at least one comparative full cell profile by directly adjusting the reference positive electrode profile Rp and the reference negative electrode profile Rn. Alternatively, at least one comparative full cell profile may be pre-allocated based on the reference positive electrode profile Rp and the reference negative electrode profile Rn and stored in the storage unit 150. In this case, the profile determination unit 110 can also obtain the comparative full cell profile by accessing the storage unit 150 and reading it.

[0113] The profile determination unit 110 can generate multiple comparative full-cell profiles from the reference positive electrode profile Rp and the reference negative electrode profile Rn by repeatedly performing an adjustment process in which the reference positive electrode profile Rp and the reference negative electrode profile Rn are each adjusted to various levels and then combined. These comparative full-cell profiles may be referred to as "adjusted reference full-cell profiles".

[0114] The profile determination unit 110 can identify one of the multiple comparison full cell profiles that minimizes the error with the measured full cell profile M.

[0115] Subsequently, the profile determination unit 110 can determine the adjusted positive electrode profile and adjusted negative electrode profile mapped to the identified comparative full cell profile as the positive electrode profile and negative electrode profile of the battery.

[0116] In this regard, various known methods available at the time of filing of the present invention can be used to determine the error between two profiles that can each be represented by a two-dimensional coordinate system. For example, the integral of the absolute value over the region between the two profiles or the root mean square error (RMSE) can be used as the error between the two profiles.

[0117] According to this configuration of the present invention, various state information for the battery can be obtained based on the finally determined positive and negative electrode profiles. The finally determined positive and negative electrode profiles may be mapped to a comparative full cell profile mapped to the minimum error. In particular, the comparative full cell profile obtained from the finally determined positive and negative electrode profiles can be said to have almost identical shape and other characteristics to the measured full cell profile M.

[0118] Therefore, according to the present invention, the positive electrode profile and negative electrode profile of the battery can be obtained non-destructively.

[0119] If the battery is new, analyzing the positive and negative electrode profiles of the battery makes it easier to diagnose whether or not a defect has occurred in the battery, and if so, what type of defect it is.

[0120] For batteries that have been verified as good quality and are currently in use, the degree of degradation in each degradation category can be determined from the battery's positive and negative electrode profiles.

[0121] Furthermore, according to one embodiment of the present invention, the positive electrode profile and negative electrode profile of a battery can be obtained in a simple manner. 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 150. That is, it is not necessary for multiple reference positive electrode profiles Rp and / or multiple reference negative electrode profiles Rn to be stored in the storage unit 150. Therefore, the storage capacity of the storage unit 150 does not need to be large, and it is not necessary to perform many prior tests required to secure multiple reference positive electrode profiles Rp and / or multiple reference negative electrode profiles Rn.

[0122] Figures 6 to 8 illustrate an example of the process for generating a comparative full-cell profile used for comparison with a measured full-cell profile M according to one embodiment of the present invention.

[0123] The process of generating a comparative full-cell profile, as described with reference to Figures 6 to 8, is performed in the following order: a first routine (see Figure 4) to set four points (positive electrode involvement start point, positive electrode involvement end point, negative electrode involvement start point, and negative electrode involvement end point) corresponding to the voltage range of interest; a second routine (see Figure 5) to perform profile shifting; and a third routine (see Figure 6) to perform capacitance scaling. That is, the process of generating a comparative full-cell profile according to one embodiment of the present invention includes the first to third routines.

[0124] First, referring to Figure 6, the reference positive electrode profile Rp and the reference negative electrode profile Rn are the same as those shown in Figure 4.

[0125] The profile determination unit 110 determines the positive electrode involvement start point pi, positive electrode involvement end point pf, negative electrode involvement start point ni, and negative electrode involvement end point nf in the reference positive electrode profile Rp and reference negative electrode profile Rn.

[0126] Either the positive electrode involvement start point pi or the negative electrode involvement start point ni depends on the other.

[0127] For example, the profile determination unit 110 may divide the positive electrode voltage range from the start point to the end point (or second set voltage) of the reference positive electrode profile Rp into a plurality of minute voltage intervals, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the positive electrode involvement start point pi. Each minute voltage interval may have a predetermined size (e.g., 0.01V). Subsequently, the profile determination unit 110 may set a point in the reference negative electrode profile Rn that is smaller by a first set voltage (e.g., 3V) than the positive electrode involvement start point pi as the negative electrode involvement start point ni.

[0128] In another example, the profile determination unit 110 may divide the negative electrode voltage range from the start point to the end point of the reference negative electrode profile Rn into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the negative electrode involvement start point ni. Subsequently, the profile determination unit 110 may search for a point in the reference positive electrode profile Rp that is greater than the negative electrode involvement start point ni by a first set voltage, and set the searched point as the positive electrode involvement start point pi.

[0129] Either the positive electrode-involved termination point pf or the negative electrode-involved termination point nf depends on the other.

[0130] For example, the profile determination unit 110 may divide the voltage range from the second set voltage to the end point of the reference positive electrode profile Rp into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the positive electrode involvement termination point pf. Subsequently, the profile determination unit 110 may set a point in the reference negative electrode profile Rn that is smaller than the positive electrode involvement termination point pf by a second set voltage (e.g., 4V) as the negative electrode involvement termination point nf.

[0131] In another example, the profile determination unit 110 may divide the negative voltage range of the reference negative electrode profile Rn from the start point to the end point into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the negative electrode involvement termination point nf. Subsequently, the profile determination unit 110 may search for a point in the reference positive electrode profile Rp that is greater than the negative electrode involvement termination point nf by a second set voltage, and set the searched point as the positive electrode involvement termination point pf.

[0132] Once the determination of the positive electrode involvement start point pi, positive electrode involvement end point pf, negative electrode involvement start point ni, and negative electrode involvement end point nf is complete, the profile determination unit 110 shifts at least one of the reference positive electrode profile Rp and reference negative electrode profile Rn to the left or right along the horizontal axis.

[0133] Referring to Figure 7, the profile determination unit 110 may shift the reference positive electrode profile Rp to the left, or shift the reference negative electrode profile Rn to the right (towards higher capacity), or both, so that the capacitance values ​​of the positive electrode involvement start point pi and the negative electrode involvement start point ni match.

[0134] Alternatively, the profile determination unit 110 may shift the reference positive electrode profile Rp to the left, or shift the reference negative electrode profile Rn to the right, or both, so that the capacitance values ​​of the positive electrode involvement termination point pf and the negative electrode involvement termination point nf match.

[0135] Figure 7 shows the result of generating an adjusted reference positive electrode profile Rp' by shifting only the reference positive electrode profile Rp to the left, where the capacitance value at the positive electrode involvement start point pi' matches the capacitance value at the negative electrode involvement start point ni. The adjusted reference positive electrode profile Rp' is the result of applying an adjustment to the reference positive electrode profile Rp that shifts it to the left by the difference in capacitance values ​​between the positive electrode involvement start point pi and the negative electrode involvement start point ni. Therefore, the two points pi and pi' differ only in capacitance value, but have the same voltage. The two points pf and pf' differ only in capacitance value, but have the same voltage.

[0136] Once adjusted profiles Rp' and Rn are secured, obtained by shifting at least one of the reference positive electrode profile Rp and the reference negative electrode profile Rn, the profile determination unit 110 scales at least one capacitance range of the adjusted profiles Rp' and Rn.

[0137] Referring to Figure 7, the profile determination unit 110 further performs an adjustment process on at least one of the adjusted reference positive electrode profile Rp' and reference negative electrode profile Rn, which involves shrinking or expanding it along the horizontal axis.

[0138] Referring to Figure 8, the profile determination unit 110 can generate an adjusted reference positive electrode profile Rp'' by reducing or expanding the adjusted reference positive electrode profile Rp' so that the capacitance range between two points pi' and pf' in the adjusted reference positive electrode profile Rp' matches the capacitance range of the measured full cell profile M. In this case, one of the two points pi' and pf', pi', can be fixed. This ensures that the capacitance range between the two points pi' and pf'' in the adjusted reference positive electrode profile Rp'' matches the capacitance range of the measured full cell profile M.

[0139] Furthermore, the profile determination unit 110 can generate an adjusted reference negative electrode profile Rn' by reducing or expanding the reference negative electrode profile Rn so that the capacity range between the two points ni and nf of the reference negative electrode profile Rn also matches the capacity range of the measured full cell profile M. In this case, one of the two points ni and nf, point ni, can be fixed. As a result, the capacity range between the two points ni and nf' of the adjusted reference negative electrode profile Rn' will match the capacity range of the measured full cell profile M.

[0140] In Figure 8, the adjusted reference positive electrode profile Rp'' is the result of reducing the adjusted reference positive electrode profile Rp' shown in Figure 7, and the adjusted reference negative electrode profile Rn' is the result of expanding the reference negative electrode profile Rn shown in Figure 7.

[0141] The positive electrode involvement endpoint pf in the adjusted reference positive electrode profile Rp'' corresponds to the positive electrode involvement endpoint pf' in the adjusted reference positive electrode profile Rp'. The negative electrode involvement endpoint nf' in the adjusted reference negative electrode profile Rn' corresponds to the negative electrode involvement endpoint nf in the reference negative electrode profile Rn.

[0142] The volume range between the positive electrode involvement start point pi' and the positive electrode involvement end point pf'' of the adjusted reference positive electrode profile Rp'' matches the volume range of the measured full cell profile M. Similarly, the volume range between the negative electrode involvement start point ni and the negative electrode involvement end point nf'' of the adjusted reference negative electrode profile Rn'' matches the volume range of the measured full cell profile M.

[0143] Furthermore, the capacitance range between two points pi' and pf'' of the adjusted reference positive electrode profile Rp'' matches the capacitance range between two points ni and nf' of the adjusted reference negative electrode profile Rn'. The profile determination unit 110 can generate a comparative full cell profile S by subtracting the profile between the two points pi' and pf'' of the adjusted reference positive electrode profile Rp'' from the profile between the two points ni and nf' of the adjusted reference negative electrode profile Rn'.

[0144] The profile determination unit 110 can calculate the error (profile error) between the comparison full cell profile S and the measured full cell profile M.

[0145] The profile determination unit 110 can map at least two of the following to each other and record them in the storage unit 150: the adjusted reference positive electrode profile Rp'', the adjusted reference negative electrode profile Rn', the positive electrode involvement start point pi', the positive electrode involvement end point pf'', the negative electrode involvement start point ni, the negative electrode involvement end point nf', the first scale factor, the second scale factor, the comparison full cell profile S, and the profile error. The first scale factor may represent the ratio of the capacity difference between two points pi' and pf'' to the capacity difference between two points pi0 and pf0. The second scale factor may represent the ratio of the capacity difference between two points ni and nf' to the capacity difference between two points ni0 and nf0.

[0146] Here, the profile determination unit 110 can calculate the positive electrode change ratio ps of the adjusted reference positive electrode profile Rp'' relative to the reference positive electrode profile Rp. The profile determination unit 110 can also calculate the negative electrode change ratio ns of the adjusted reference positive electrode profile Rn' relative to the reference negative electrode profile Rn. For example, the profile determination unit 110 can determine the first scale factor as the positive electrode change ratio ps and the second scale factor as the negative electrode change ratio ns.

[0147] On the other hand, as mentioned above, if the positive electrode voltage range of the reference positive electrode profile Rp is divided into multiple minute voltage intervals, the boundary point between two adjacent minute voltage intervals can be set as the positive electrode involvement start point pi.

[0148] For example, if the positive electrode voltage range of the reference positive electrode profile Rp is divided into 100 minute voltage ranges, there may be 100 boundary points that can be set as the positive electrode involvement start point pi. Also, if the voltage range of the reference positive electrode profile Rp above the second set voltage is divided into 40 minute voltage ranges, there may be 40 boundary points that can be set as the positive electrode involvement end point pf. In this case, up to 4,000 distinct comparison full cell profiles can be generated.

[0149] Of course, it will be easily understood by those skilled in the art that the number of comparative full-cell profiles that can be generated increases as the size of the minute voltage interval decreases, and conversely, the number of comparative full-cell profiles that can be generated decreases as the size of the minute voltage interval increases.

[0150] After identifying the minimum profile error among the multiple comparison full-cell profiles generated as described above, the profile determination unit 110 may retrieve information mapped to the minimum profile error (for example, at least one of the following: positive electrode involvement start point, positive electrode involvement end point, negative electrode involvement start point, negative electrode involvement end point, first scale factor, and second scale factor) from the storage unit 150.

[0151] Figures 9 to 11 illustrate another example of the process of generating a comparative full-cell profile used for comparison with the measured full-cell profile M by one embodiment of the present invention. For reference, the embodiments shown in Figures 9 to 11 are independent of the embodiments shown in Figures 6 to 8. Therefore, terms and reference numerals common to the embodiments shown in Figures 6 to 8 and Figures 9 to 11 are limited to those of each respective embodiment.

[0152] The process for generating a comparative full-cell profile, as described with reference to Figures 9 to 11, is performed in the following order: a fourth routine (see Figure 9) for performing capacity scaling, a fifth routine (see Figure 10) for setting four points (positive electrode involvement start point, positive electrode involvement end point, negative electrode involvement start point, negative electrode involvement end point), and a sixth routine (see Figure 11) for performing profile shifting. That is, the process for generating a comparative full-cell profile according to other embodiments of the present invention includes routines 4 to 6.

[0153] Referring to Figure 9, the reference positive electrode profile Rp and the reference negative electrode profile Rn are identical to those shown in Figure 4.

[0154] The profile determination unit 110 applies the first scale factor and the second scale factor selected from the scaling numerical range to the reference positive electrode profile Rp and the reference negative electrode profile Rn, respectively, to generate the adjusted reference positive electrode profile Rp' and the adjusted reference negative electrode profile Rn'.

[0155] The scaling numerical range is predetermined or can vary depending on the ratio of the size of the volume range of the measured full-cell profile M to the size of the volume range of the reference full-cell profile R. For example, if values ​​with 0.1% intervals (i.e., 90%, 90.1%, 90.2%, ..., 98.9%, 99%) are selectable as the first and second scale factors within the scaling numerical range (e.g., 90-99%), then 91 values ​​can be selected as the first and second scale factors, respectively. In this case, 91 × 91 = 8,281 adjustment levels (combinations of the first and second scale factors) can generate up to 8,281 adjusted profile pairs. An adjusted profile pair means a combination of an adjusted positive electrode profile and an adjusted negative electrode profile.

[0156] The adjusted reference positive electrode profile Rp' and adjusted reference negative electrode profile Rn' shown in Figure 9 represent the results of applying a first scale factor and a second scale factor, respectively, that are less than 100%, to the reference positive electrode profile Rp and the reference negative electrode profile Rn.

[0157] Because the first and second scale factors are less than 100%, the adjusted reference positive electrode profile Rp' is the reference positive electrode profile Rp scaled down along the horizontal axis, and the adjusted reference negative electrode profile Rn' is the reference negative electrode profile Rn scaled down along the horizontal axis. For the sake of understanding, the starting points of the reference positive electrode profile Rp and the reference negative electrode profile Rn are fixed, and only the remaining portions are shown scaled down to the left along the horizontal axis.

[0158] Referring to Figure 10, the profile determination unit 110 determines the positive electrode involvement start point pi', positive electrode involvement end point pf', negative electrode involvement start point ni', and negative electrode involvement end point nf' in the adjusted reference positive electrode profile Rp' and the adjusted reference negative electrode profile Rn'.

[0159] Either the positive electrode involvement start point pi' or the negative electrode involvement start point ni' may depend on the other. Similarly, either the positive electrode involvement end point pf' or the negative electrode involvement end point nf' may depend on the other. Furthermore, either the positive electrode involvement start point pi' or the positive electrode involvement end point pf' may be set based on the other.

[0160] That is, once one of the positive electrode involvement start point pi', positive electrode involvement end point pf', negative electrode involvement start point ni', and negative electrode involvement end point nf' is set, the remaining three points can be automatically set by the first set voltage, the second set voltage, and / or the size of the capacity range of the measured full cell profile M (e.g., the charge capacity from SOC (State of Charge) 0 to 100%).

[0161] For example, the profile determination unit 110 may divide the positive electrode voltage range from the start point to the end point (or second set voltage) of the adjusted reference positive electrode profile Rp' into a plurality of minute voltage intervals, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the positive electrode involvement start point pi'. Subsequently, the profile determination unit 110 may set a point in the adjusted reference negative electrode profile Rn that is smaller by a first set voltage (e.g., 3V) than the positive electrode involvement start point pi' as the negative electrode involvement start point ni'.

[0162] In another example, the profile determination unit 110 may divide the negative voltage range from the start point to the end point of the adjusted reference negative electrode profile Rn' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the negative electrode involvement start point ni'. Subsequently, the profile determination unit 110 may search for a point in the adjusted reference positive electrode profile Rp' that is greater than the negative electrode involvement start point ni' by a first set voltage, and set the searched point as the positive electrode involvement start point pi'.

[0163] In yet another example, the profile determination unit 110 may divide the voltage range from the second set voltage to the end point of the adjusted reference positive electrode profile Rp' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the positive electrode involvement end point pf'. Subsequently, the profile determination unit 110 may search for a point in the adjusted reference negative electrode profile Rn' that is smaller than the positive electrode involvement end point pf' by the second set voltage (e.g., 4V), and set the searched point as the negative electrode involvement end point nf'.

[0164] In yet another example, the profile determination unit 110 may divide the negative voltage range from the start to the end point of the adjusted reference negative electrode profile Rn' into a plurality of minute voltage intervals of a predetermined size, and then set the boundary point of two adjacent minute voltage intervals among the plurality of minute voltage intervals as the negative electrode involvement termination point nf'. Subsequently, the profile determination unit 110 may search for a point in the adjusted reference positive electrode profile Rp' that is greater than the negative electrode involvement termination point nf' by a second set voltage, and set the searched point as the positive electrode involvement termination point pf'.

[0165] Once one of the positive electrode involvement start point pi', positive electrode involvement end point pf', negative electrode involvement start point ni', and negative electrode involvement end point nf' is determined, the profile determination unit 110 may further determine the remaining three points based on the determined point.

[0166] For example, if the positive electrode involvement start point pi' is determined first, the profile determination unit 110 may set a point in the adjusted reference positive electrode profile Rp' that has a capacitance value larger by the size of the capacitance range of the measured full cell profile M than the capacitance value of the positive electrode involvement start point pi' as the positive electrode involvement end point pf'. Alternatively, the profile determination unit 110 may search for a point in the adjusted reference negative electrode profile Rn' that is lower by a first set voltage than the voltage of the positive electrode involvement start point pi', and set the found point as the negative electrode involvement start point ni'. Furthermore, the profile determination unit 110 may set a point in the adjusted reference negative electrode profile Rn' that has a capacitance value larger by the size of the capacitance range of the measured full cell profile M than the capacitance value of the negative electrode involvement start point ni' as the negative electrode involvement end point nf'.

[0167] In another example, if the positive electrode involvement termination point pf' is determined first, the profile determination unit 110 may set a point in the adjusted reference positive electrode profile Rp' that has a capacitance value smaller by the size of the capacitance range of the measured full cell profile M than the capacitance value of the positive electrode involvement termination point pf' as the positive electrode involvement start point pi'. Alternatively, the profile determination unit 110 may search for a point in the adjusted reference negative electrode profile Rn' that is lower by a second set voltage than the voltage of the positive electrode involvement termination point pf', and set the found point as the negative electrode involvement termination point nf'. Furthermore, the profile determination unit 110 may set a point in the adjusted reference negative electrode profile Rn' that has a capacitance value smaller by the size of the capacitance range of the measured full cell profile M than the capacitance value of the negative electrode involvement termination point nf' as the negative electrode involvement start point ni'.

[0168] In another example, once the negative electrode involvement start point ni' is determined, the profile determination unit 110 may set a point in the adjusted reference negative electrode profile Rn' that has a capacitance value greater than the capacitance value of the negative electrode involvement start point ni' by the size of the capacitance range of the measured full cell profile M as the negative electrode involvement end point nf'. The profile determination unit 110 may also search for a point in the adjusted reference positive electrode profile Rp' that is higher than the voltage of the negative electrode involvement start point ni' by a first set voltage, and set the searched point as the positive electrode involvement start point pi'. The profile determination unit 110 may also set a point in the adjusted reference positive electrode profile Rp' that has a capacitance value greater than the capacitance value of the positive electrode involvement start point pi' by the size of the capacitance range of the measured full cell profile M as the positive electrode involvement end point pf'.

[0169] In another example, once the negative electrode involvement termination point nf' is determined, the profile determination unit 110 may set a point in the adjusted reference negative electrode profile Rn' that has a capacitance value smaller by the size of the capacitance range of the measured full cell profile M than the capacitance value of the negative electrode involvement termination point nf' as the negative electrode involvement start point ni'. The profile determination unit 110 may also search for a point in the adjusted reference positive electrode profile Rp' that is higher by a second set voltage than the voltage of the negative electrode involvement termination point nf', and set the found point as the positive electrode involvement termination point pf'. Furthermore, the profile determination unit 110 may set a point in the adjusted reference positive electrode profile Rp' that has a capacitance value smaller by the size of the capacitance range of the measured full cell profile M than the capacitance value of the positive electrode involvement termination point pf' as the positive electrode involvement start point pi'.

[0170] Once the determination of the positive electrode involvement start point pi', positive electrode involvement end point pf', negative electrode involvement start point ni', and negative electrode involvement end point nf' is complete based on the pair of first and second scale factors, the profile determination unit 110 may shift at least one of the adjusted reference positive electrode profile Rp' and adjusted reference negative electrode profile Rn' to the left or right along the horizontal axis so that the capacitance values ​​of the positive electrode involvement start point pi' and negative electrode involvement start point ni' match, or so that the capacitance values ​​of the positive electrode involvement end point pf' and negative electrode involvement end point nf' match.

[0171] The adjusted reference negative electrode profile Rn'' shown in Figure 11 is obtained by shifting only the adjusted reference negative electrode profile Rn' shown in Figure 10 to the right. As a result, the capacitance values ​​at the positive electrode involvement start point pi' and the negative electrode involvement start point ni' match. In relation to this, the capacitance difference between the positive electrode involvement start point pi' and the positive electrode involvement end point pf' is the same as the capacitance difference between the negative electrode involvement start point ni' and the negative electrode involvement end point nf. Therefore, when the capacitance values ​​at the positive electrode involvement start point pi' and the negative electrode involvement start point ni'' match, the capacitance values ​​at the positive electrode involvement end point pf' and the negative electrode involvement end point nf'' also match.

[0172] Referring to Figure 11, the profile determination unit 110 can generate a comparative full cell profile U by subtracting the partial profile between two points pi' and pf' of the adjusted reference positive electrode profile Rp' from the partial profile between two points ni'' and nf'' of the adjusted reference negative electrode profile Rn''.

[0173] The profile determination unit 110 can calculate the error (profile error) between the comparison full cell profile U and the measured full cell profile M.

[0174] The profile determination unit 110 can map at least two of the following to each other and record them in the storage unit 150: the adjusted reference positive electrode profile Rp', the adjusted reference negative electrode profile Rn'', the positive electrode involvement start point pi', the positive electrode involvement end point pf', the negative electrode involvement start point ni'', the negative electrode involvement end point nf'', the first scale factor, the second scale factor, the comparison full cell profile U, and the profile error.

[0175] Here, the profile determination unit 110 can calculate the positive electrode change ratio ps of the adjusted reference positive electrode profile Rp' relative to the reference positive electrode profile Rp. The profile determination unit 110 can also calculate the negative electrode change ratio ns of the adjusted reference positive electrode profile Rn'' relative to the reference negative electrode profile Rn. For example, the profile determination unit 110 may determine the first scale factor as the positive electrode change ratio ps and the second scale factor as the negative electrode change ratio ns.

[0176] As described above, the profile determination unit 110 can generate a corresponding comparison full cell profile for each pair of first and second scale factors selected from the scaling numerical range. Since there are multiple pairs of first and second scale factors, it is obvious that multiple comparison full cell profiles will also be generated. After identifying the minimum profile error among the multiple comparison full cell profiles, the profile determination unit 110 can obtain information mapped to the minimum profile error from the storage unit 150.

[0177] The battery diagnostic device 100 according to the present invention is connected to a display device (not shown) and can output information about batteries diagnosed as being in an abnormal state. This allows the information about batteries diagnosed as being in an abnormal state to be displayed on the display device.

[0178] The battery diagnostic device 100 according to the present invention is connected to an alarm device (not shown) and can output information about a battery diagnosed as being in an abnormal state, thereby activating the alarm device.

[0179] The battery diagnostic device 100 according to the present invention is applicable to a BMS (Battery Management System). That is, the BMS according to the present invention may include the battery diagnostic device 100 described above. In such a configuration, at least some of the components of the battery diagnostic device 100 can be implemented by complementing or adding to the functions of components included in a conventional BMS. For example, the profile determination unit 110, load amount calculation unit 120, state diagnosis unit 130, resistance calculation unit 140, and storage unit 150 of the battery diagnostic device 100 can be implemented as components of a BMS.

[0180] Furthermore, the battery diagnostic device 100 according to the present invention may be provided in the battery pack 1. That is, the battery pack 1 according to the present invention may include the aforementioned battery diagnostic device 100 and one or more battery cells. The battery pack 1 may further include electrical components (relays, fuses, etc.) and a case.

[0181] Figure 12 shows an exemplary configuration of a battery pack 1 including a battery diagnostic device 100 according to one embodiment of the present invention.

[0182] The positive terminal of battery 10 may be connected to the positive terminal P+ of battery pack 1, and the negative terminal of battery 10 may be connected to the negative terminal P- of battery pack 1.

[0183] The measurement unit 20 may be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. Specifically, the measurement unit 20 may be connected to the positive terminal of the battery 10 via the first sensing line SL1 and to the negative terminal of the battery 10 via the second sensing line SL2. The measurement unit 20 may measure the voltage of the battery 10 based on the voltages measured by the first sensing line SL1 and the second sensing line SL2, respectively.

[0184] The measurement unit 20 may be connected to the current measurement unit A via the third sensing line SL3. For example, the current measurement unit A may be an ammeter or shunt resistor that measures the charging and discharging currents of the battery 10. The measurement unit 20 may measure the charging current of the battery 10 via the third sensing line SL3 and calculate the charge amount. The measurement unit 20 may also measure the discharging current of the battery 10 via the third sensing line SL3 and calculate the discharge amount.

[0185] The load may be connected at one end to the positive terminal P+ of the battery pack 1 and at the other end to the negative terminal P- of the battery pack 1. In this way, the positive terminal of the battery 10, the positive terminal P+ of the battery pack 1, the load, the negative terminal P- of the battery pack 1, and the negative terminal of the battery 10 can be electrically connected.

[0186] For example, the load could be a charge / discharge device, or a motor of an electric vehicle powered by the battery 10.

[0187] A battery diagnostic device 100 according to one embodiment of the present invention may be included in a battery manufacturing system (not shown).

[0188] Here, the battery manufacturing system may be a system applied to the process by which a battery is manufactured. For example, a battery may be manufactured to include an electrode assembly, an enclosure, and an electrolyte. The enclosure provides a space in which the electrode assembly is housed, and the electrode assembly can be at least partially impregnated by injecting the electrolyte into this space. The manufacturing of the battery may then be completed by finally sealing the enclosure. The battery may then be completed through activation and degassing processes, etc.

[0189] The manufactured battery can then be diagnosed by a battery diagnostic device 100. Preferably, the condition of the battery in question can be diagnosed based on the resistance distribution and positive electrode load distribution of multiple reference batteries manufactured by the same process.

[0190] A battery manufacturing system according to one embodiment of the present invention can diagnose whether a manufactured battery is good or bad by diagnosing whether at least one of the active material, binder, and conductive material is in an over-filled state in the positive electrode of the manufactured battery.

[0191] Figure 13 is a flowchart illustrating a battery diagnostic method according to one embodiment of the present invention.

[0192] Preferably, each step of the battery diagnostic method may be performed by the battery diagnostic device 100. For the sake of clarity, the following will either omit or briefly explain any content that overlaps with what has been described above.

[0193] Referring to Figure 13, the battery diagnostic method may include a positive electrode profile determination step S100, a positive electrode load amount calculation step S200, a comparison step S300, and a state diagnosis step S400.

[0194] The positive electrode profile determination step S100 is a step in which the positive electrode profile of the battery is determined by adjusting the reference positive electrode profile and the reference negative electrode profile to fit the measurement full cell profile that shows the correspondence between the battery capacity and voltage, and this step can be performed by the profile determination unit 110.

[0195] For example, the profile determination unit 110 may shift the reference positive electrode profile and the reference negative electrode profile to fit the full cell profile being measured, or perform capacity scaling.

[0196] The positive electrode load calculation step S200 is a step in which the positive electrode load of the battery is calculated based on the positive electrode profile of the battery, and can be performed by the load calculation unit 120.

[0197] For example, the load amount calculation unit 120 can calculate the positive electrode load amount by considering the positive electrode change ratio, a preset reference positive electrode capacity, and a preset reference area.

[0198] The comparison step S300 is a step in which the battery resistance is compared with a preset resistance range and the battery's positive electrode load is compared with a preset load range, and can be performed by the condition diagnosis unit 130.

[0199] For example, if the positive electrode load of the battery is less than or equal to the upper limit and greater than or equal to the lower limit of the load range, the status diagnosis unit 130 can determine that the positive electrode load of the battery falls within the load range.

[0200] Conversely, if the positive electrode load of the battery exceeds the upper limit of the load range or falls below the lower limit, the status diagnosis unit 130 may determine that the positive electrode load of the battery does not fall within the load range.

[0201] The status diagnosis stage S400 is a stage in which the status of the battery is diagnosed based on the resistance comparison result and the positive electrode load amount comparison result, and can be performed by the status diagnosis unit 130.

[0202] For example, the status diagnosis unit 130 can diagnose the battery as being in a normal state if the resistance falls within the resistance range and the positive electrode load falls within the load range.

[0203] Conversely, the condition diagnosis unit 130 may diagnose the battery condition as abnormal if the resistance does not fall within the resistance range or the positive electrode load does not fall within the load range.

[0204] The embodiments of the present invention described above are not necessarily carried out through apparatus and methods, but may also be carried out through a program that performs functions corresponding to the configuration of the embodiments of the present invention, or through a recording medium on which such a program is recorded. Such implementation should be easily carried out by experts in the art to which the present invention belongs, based on the above-described embodiments.

[0205] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that a wide range of modifications and variations are possible within the equivalent scope of the technical idea and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains.

[0206] Furthermore, since the present invention described above can be substituted, modified, and altered in various ways by a person with ordinary skill in the art to which the present invention belongs, without departing from the technical spirit of the invention, it is not limited by the embodiments described above and the accompanying drawings, and all or part of each embodiment can be selectively combined to form a variety of modifications. [Explanation of Symbols]

[0207] 100 Battery diagnostic device 110 Profile determination unit 120 Load Amount Calculation Unit 130 Condition Diagnosis Department 140 Resistance Calculation Section 150 Preservation Department

Claims

1. A profile determination unit that determines the positive electrode profile of a battery by adjusting the reference positive electrode profile and reference negative electrode profile to fit a measurement full cell profile that shows the correspondence between battery capacity and voltage, A load amount calculation unit that calculates the positive electrode load amount of the battery based on the positive electrode profile of the battery, A battery diagnostic device comprising: a condition diagnostic unit that compares the resistance of the battery with a preset resistance range, compares the positive electrode load of the battery with a preset load range, and diagnoses the state of the battery based on the resistance comparison result and the positive electrode load comparison result.

2. The aforementioned condition diagnosis unit is When the resistance falls within the resistance range and the positive electrode load falls within the load range, the state of the battery is diagnosed as normal. The battery diagnostic device according to claim 1, characterized in that it diagnoses the state of the battery as abnormal when the resistance does not fall within the resistance range or the positive electrode load does not fall within the load range.

3. The battery diagnostic device according to claim 2, characterized in that the abnormal condition is a state in which at least one of the active material, binder, and conductive material is overfilled into the positive electrode of the battery.

4. The battery diagnostic device according to claim 1, characterized in that the load amount calculation unit calculates the positive electrode load amount considering the positive electrode change ratio of the battery's positive electrode profile with respect to the reference positive electrode profile.

5. The battery diagnostic device according to claim 4, characterized in that the load amount calculation unit calculates the positive electrode load amount considering the positive electrode change ratio, a preset reference positive electrode capacity, and a preset reference area.

6. The battery diagnostic device according to claim 5, characterized in that the load amount calculation unit calculates the positive electrode load amount, which indicates the positive electrode capacity per unit area, by multiplying the reference positive electrode capacity by the positive electrode change ratio and dividing the result by the reference area.

7. The aforementioned resistance range is a range set based on the resistance distribution of multiple reference batteries. The battery diagnostic device according to claim 1, characterized in that the load amount range is a range set based on the positive electrode load amount distribution of the plurality of reference batteries.

8. The battery diagnostic device according to claim 1, further comprising a resistance calculation unit that calculates the resistance of the battery based on the measured full cell profile.

9. A battery manufacturing system characterized by including a battery diagnostic device according to any one of claims 1 to 8.

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

11. A positive electrode profile determination step involves adjusting the reference positive electrode profile and reference negative electrode profile to fit a measured full cell profile that shows the correspondence between battery capacity and voltage, thereby determining the positive electrode profile of the battery. A positive electrode load calculation step, which calculates the positive electrode load amount of the battery based on the positive electrode profile of the battery, A comparison step in which the resistance of the battery is compared with a preset resistance range and the positive electrode load of the battery is compared with a preset load range, A battery diagnostic method characterized by including a state diagnostic step of diagnosing the state of the battery based on the resistance comparison results and positive electrode load comparison results of the comparison step.

Images