Apparatus and method for diagnosing battery
Patent Information
- Application Number
- PCT/KR2024/012075
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-08-31
- Filing Date
- 2024-08-13
- Publication Date
- 2025-03-06
Smart Images

Figure KR2024012075_06032025_PF_FP_ABST
Abstract
Description
Battery diagnostic device and method
[0001] This application claims priority from Korean Patent Application No. 10-2023-0115860, filed August 31, 2023, the entire disclosure of which is incorporated herein by reference.
[0002] The present invention relates to a battery diagnostic device and method, and more particularly, to a battery diagnostic device and method for diagnosing the state of a battery capable of repeated charging and discharging.
[0003] Recently, as the demand for portable electronic products such as laptops, digital cameras, and mobile phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, and satellites has been in full swing, research into high-performance batteries capable of repeated charging and discharging is actively being conducted.
[0004] Currently commercially available batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries have the advantages of having a relatively long lifespan, a very low self-discharge rate, and high energy density because they have almost no memory effect compared to nickel-based batteries.
[0005] While much research is being conducted on technologies to increase battery capacity and density, technologies to extend battery life and improve safety are also crucial. In particular, to improve battery safety, technologies that accurately diagnose the current battery condition are required.
[0006] Traditionally, battery condition has been diagnosed by analyzing a battery profile, which indicates the relationship between battery capacity and voltage. For example, the battery's capacity and voltage are measured during the charging process, and the battery's condition is diagnosed by analyzing the battery profile, which indicates the relationship between the measured capacity and voltage. Alternatively, a battery's condition can be diagnosed based on the capacity and voltage measured during the discharge process. Therefore, to accurately diagnose a battery's current condition, a battery profile that accurately reflects the battery's current condition is required.
[0007] However, existing technologies have the problem that diagnosing batteries requires a lot of time and cost because they perform low-rate charging and discharging at a low current of 0.05C (C-rate) to obtain an accurate battery profile, and that they cannot accurately and quickly diagnose a large number of batteries.
[0008] On the other hand, in order to shorten the battery diagnosis time, when charging and discharging the battery at a high current rate of 0.3C or higher, there is a problem in that the battery profile obtained includes overpotential, and due to the influence of this overpotential, the battery profile cannot accurately reflect the current state of the battery.
[0009] When using a battery profile that includes overvoltage like this, the battery condition cannot be accurately diagnosed, so low-rate charge / discharge is used, which requires a lot of time and cost to diagnose the battery condition.
[0010] The present invention has been devised to solve the above problems, and its purpose is to provide a battery diagnosis device and method capable of diagnosing the state of a battery by considering the overvoltage of the battery that occurs when charging and discharging using a high-rate current.
[0011] Other objects and advantages of the present invention will be clearly understood through the embodiments of the present invention described below. Furthermore, it will be readily understood that these objects and advantages of the present invention can be realized by the components of the present invention set forth in the claims.
[0012] According to one aspect of the present invention, a battery diagnosis device includes: a profile acquisition unit configured to acquire a battery profile indicating a correspondence between a voltage and a capacity of a diagnosis target battery that is charged or discharged at a predetermined target charge-rate (C-rate); a profile correction unit configured to generate a correction profile by correcting the battery profile based on an overvoltage profile indicating an overvoltage by capacity of a reference battery that occurs when the reference battery is charged or discharged at the target charge-rate, and to generate an adjusted negative electrode profile that is adjusted to indicate a correspondence between a negative electrode capacity and a negative electrode potential of the diagnosis target battery using the correction profile; and a control unit configured to extract a negative electrode loading value from the adjusted negative electrode profile as a diagnostic factor for the diagnosis target battery and to diagnose a state of the diagnosis target battery based on the extracted diagnostic factor.
[0013] In one embodiment, the overvoltage profile may be a profile representing a voltage difference by capacity between a first battery profile of the reference battery obtained when the reference battery is charged or discharged at a reference rate, and a second battery profile of the reference battery obtained when the reference battery is charged or discharged at the target rate.
[0014] In one embodiment, the profile correction unit may be configured to generate the correction profile by calculating a voltage difference by capacity between the battery profile and the overvoltage profile.
[0015] In one embodiment, the battery diagnostic device further includes overvoltage profiles indicating overvoltages according to the capacity of the reference battery that occur when the reference battery is charged or discharged at a rate different from the target rate, and a storage unit that stores the overvoltage profiles, and the profile correction unit may be configured to select an overvoltage profile corresponding to the target rate among the overvoltage profiles stored in the storage unit, and generate the correction profile using the selected overvoltage profile.
[0016] In one embodiment, the profile correction unit may be configured to generate a comparison full-cell profile corresponding to the correction profile by adjusting a predetermined reference positive electrode profile and a reference negative electrode profile to mutually synthesize them, and to provide the reference negative electrode profile adjusted to generate the comparison full-cell profile as the adjusted negative electrode profile.
[0017] In one embodiment, the control unit may be configured to diagnose the battery to be diagnosed as being in an abnormal state if the negative loading amount value does not fall within a predetermined threshold range.
[0018] In one embodiment, the control unit may be configured to further extract one or two or more of a negative electrode starting potential value, a negative electrode ending potential value, and a negative electrode change ratio from the adjusted negative electrode profile as diagnostic factors, and to diagnose the state of the battery to be diagnosed based on the extracted diagnostic factors.
[0019] In one embodiment, the control unit may be configured to diagnose the battery to be diagnosed as being in a normal state when the values of a predetermined number or more of the extracted diagnostic factors each fall within a corresponding threshold range.
[0020] A battery pack according to another aspect of the present invention includes a battery diagnostic device according to any one of the embodiments described above.
[0021] A battery manufacturing system according to another aspect of the present invention includes a battery diagnostic device according to any one of the embodiments described above.
[0022] According to another aspect of the present invention, a vehicle includes a battery diagnostic device according to any one of the embodiments described above.
[0023] According to another aspect of the present invention, a battery manufacturing method includes a profile acquisition step of acquiring a battery profile indicating a correspondence between a voltage and a capacity of a battery to be diagnosed when charged or discharged at a predetermined target charge-rate (C-rate); a correction profile generation step of generating a correction profile by correcting the battery profile based on an overvoltage profile indicating an overvoltage by capacity of a reference battery that occurs when the reference battery is charged or discharged at the target charge-rate; a profile adjustment step of generating an adjusted negative electrode profile adjusted to indicate a correspondence between a negative electrode capacity and a negative electrode potential of the battery to be diagnosed using the correction profile; a diagnostic factor extraction step of extracting a negative electrode loading amount value of the negative electrode profile as a diagnostic factor for the battery to be diagnosed; and a condition diagnosis step of diagnosing a condition of the battery to be diagnosed based on the negative electrode loading amount value.
[0024] The battery diagnosis device and method according to the present invention generate a correction profile by removing overvoltage from a battery profile indicating a correspondence between the capacity and voltage of the battery, and diagnose the state of the battery based on this correction profile, so there is an advantage in that the battery to be diagnosed is not forced to be charged or discharged using a low C-rate current.
[0025] In other words, according to the present invention, even when charging or discharging a battery at a current C-rate higher than the commonly used C-rate, the condition of the battery can be accurately diagnosed. As a result, the time and cost required to diagnose the condition of the battery can be reduced, and diagnosis of multiple batteries can be performed accurately and quickly.
[0026] In addition, the battery diagnosis device and method according to the present invention have the advantage of further shortening the diagnosis time by performing the diagnosis through a simplified process of extracting diagnostic factors that serve as criteria for diagnosis from a plurality of batteries, determining a critical range of values that the diagnostic factors of a normal battery can have based on the extracted diagnostic factors, and comparing the diagnostic factor values of the battery to be diagnosed with the critical range.
[0027] In addition, the battery diagnosis device and method according to the present invention can specifically diagnose the state of the battery related to the negative electrode by extracting a negative electrode-related diagnostic factor from an adjusted negative electrode profile indicating the negative electrode state of the battery and diagnosing the battery based on the extracted diagnostic factor.
[0028] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.
[0029] The following drawings attached to this specification serve to help understand the technical idea of the present invention together with the detailed description of the invention described below, and therefore the present invention should not be interpreted as being limited to matters shown in the attached drawings.
[0030] FIG. 1 is a schematic diagram illustrating a battery diagnostic device according to one embodiment of the present invention.
[0031] FIG. 2 is a diagram schematically illustrating an overvoltage profile according to one embodiment of the present invention.
[0032] FIG. 3 is a diagram schematically illustrating a battery profile according to one embodiment of the present invention.
[0033] FIG. 4 is a drawing schematically illustrating a correction profile according to one embodiment of the present invention.
[0034] FIG. 5 is a diagram schematically illustrating the distribution of diagnostic factors according to one embodiment of the present invention.
[0035] Figures 6 to 10 are diagrams illustrating the distribution of diagnostic factor values extracted from multiple batteries.
[0036] FIGS. 11 to 18 are drawings illustrating a process for adjusting a reference anode profile and a reference cathode profile according to one embodiment of the present invention.
[0037] FIG. 19 is a drawing illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention.
[0038] FIG. 20 is a drawing showing a battery manufacturing process of a battery manufacturing system according to another embodiment of the present invention.
[0039] FIG. 21 is a drawing showing an exemplary configuration of a vehicle according to another embodiment of the present invention.
[0040] FIG. 22 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.
[0041] Hereinafter, in order to clearly present a solution corresponding to the technical problem of the present invention, embodiments according to the present invention will be described in detail with reference to the attached drawings.
[0042] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner.
[0043] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.
[0044] In addition, when describing the present invention, if it is determined that a specific description of a related known configuration or air technology may obscure the gist of the present invention, a detailed description thereof will be omitted.
[0045] Additionally, terms including ordinal numbers, such as “first,” “second,” etc., used in this specification are used for the purpose of distinguishing one of the various components from the rest, and are not used to limit the components by such terms.
[0046] Throughout this specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.
[0047] Additionally, throughout this specification, when a part is said to be “connected” to another part, this includes not only cases where it is “directly connected,” but also cases where it is “indirectly connected” with another component in between.
[0048] FIG. 1 is a schematic diagram illustrating a battery diagnostic device (100) according to one embodiment of the present invention.
[0049] Referring to FIG. 1, the battery diagnostic device (100) may include a profile acquisition unit (110), a profile correction unit (120), and a control unit (130).
[0050] The profile acquisition unit (110) is configured to acquire a battery profile indicating a correspondence between the voltage and capacity of a battery to be diagnosed that is charged or discharged at a predetermined target C-rate. For example, the profile acquisition unit (110) may be configured to acquire a plurality of battery profiles (BP) indicating a correspondence between the voltage and capacity of each of a plurality of batteries.
[0051] Here, a battery may refer to a physically separate, independent cell having a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. Furthermore, a battery may refer to a battery bank, battery module, or battery pack in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be described hereinafter as referring to a single, independent cell.
[0052] Specifically, a battery profile (BP) is a profile that represents the relationship between the voltage (V) and the capacity (Q) of a battery when the battery's State of Charge (SOC) is charged from 0% to 100%. Alternatively, the battery profile (BP) may represent the relationship between the voltage (V) and the capacity (Q) when the battery's SOC is discharged from 100% to 0%. For example, the battery profile (BP) can be generated based on the voltage and electrical capacity of the battery measured while the battery is being charged or discharged at a predetermined C-rate (Current rate). Here, the C-rate of the charging current or discharging current can be maintained constant while the battery profile (BP) is being generated. That is, when the C-rate for charging and discharging is set, the set C-rate can be maintained constant until charging and discharging is completed.
[0053] For reference, 1C (C-rate) can mean the current that fully charges a completely discharged battery in 1 hour, or the current that can fully discharge a fully charged battery in 1 hour. As the C-rate increases, the corresponding current increases, and as the C-rate decreases, the corresponding current decreases. For example, 2C can mean the amount of current that fully charges a completely discharged battery in 0.5 hours, or the amount of current that can fully discharge a fully charged battery in 0.5 hours.
[0054] For example, the profile acquisition unit (110) can directly receive a battery profile (BP) from an external device. That is, the profile acquisition unit (110) can acquire a battery profile (BP) by being connected to an external device via wire and / or wirelessly and receiving the battery profile (BP) from the external device.
[0055] As another example, the profile acquisition unit (110) can receive battery information regarding the voltage (V) and capacity (Q) of the battery. Furthermore, the profile acquisition unit (110) can generate a battery profile (BP) based on the received battery information. That is, the profile acquisition unit (110) can acquire the battery profile (BP) by directly generating the battery profile (BP) based on the battery information.
[0056] The profile acquisition unit (110) may be connected to the profile correction unit (120) so as to be able to communicate with it. For example, the profile acquisition unit (110) may be connected to the control unit (130) via wire and / or wirelessly. The profile acquisition unit (110) may transmit the acquired battery profile (BP) to the profile correction unit (120).
[0057] The profile correction unit (120) can be configured to generate a plurality of correction profiles (CP) by correcting a plurality of battery profiles (BP) based on a preset overvoltage profile (OP).
[0058] For example, the profile correction unit (120) may be configured to correct the battery profile to generate a correction profile based on an overvoltage profile indicating an overvoltage by capacity of the reference battery that occurs when the reference battery is charged or discharged at the target C-rate, and to generate an adjusted negative electrode profile that is adjusted to indicate a correspondence between the negative electrode capacity and the negative electrode potential of the battery to be diagnosed using the correction profile.
[0059] Here, the overvoltage profile (OP) is a profile that represents the correspondence between the capacity and overvoltage of a battery charged or discharged with a current of a given C-rate. For example, the overvoltage profile (OP) is a profile that represents the voltage difference by capacity between a first battery profile of a reference battery obtained when the reference battery is charged or discharged at a reference C-rate, and a second battery profile of the reference battery obtained when the reference battery is charged or discharged at the target C-rate.
[0060] In general, when a battery is charged or discharged with a current having a C-rate higher than the reference C-rate, an overvoltage may be included in the measured voltage of the battery. Therefore, the overvoltage profile (OP) can be obtained by calculating the voltage difference by capacity between a first battery profile (BP1) of a reference battery charged or discharged with a current having a reference C-rate and a second battery profile (BP2) of a reference battery charged or discharged with a current having a C-rate equal to the target C-rate of the charge current or discharge current of the battery to be diagnosed.
[0061] For example, it is assumed that the reference C-rate is 0.05C and the target C-rate is 0.3C. When the reference battery is charged (or discharged) at 0.05C, a first battery profile (BP1) can be acquired. When the reference battery is charged (or discharged) at 0.3C, a second battery profile (BP2) can be acquired. The difference between the voltage of the first battery profile (BP1) corresponding to a specific capacity and the voltage of the second battery profile (BP2) can be calculated as the overvoltage at the specific capacity. That is, when the voltage difference (overvoltage) for each capacity between the first battery profile (BP1) and the second battery profile (BP2) is calculated, an overvoltage profile (OP) indicating the correspondence between the capacity and the overvoltage can be generated.
[0062] FIG. 2 is a diagram schematically illustrating an overvoltage profile (OP) according to one embodiment of the present invention.
[0063] Specifically, FIG. 2 is a diagram illustrating an overvoltage profile (OP) generated during the process of discharging a reference battery from a starting capacity (Qi) to an ending capacity (Qf). A first battery profile (BP1) can be generated by discharging the reference battery from a starting capacity (Qi) to an ending capacity (Qf) at a reference C-rate. In addition, a second battery profile (BP2) can be generated by discharging the reference battery from a starting capacity (Qi) to an ending capacity (Qf) at a target C-rate. An overvoltage profile (OP) can be generated by calculating a voltage difference for each discharge capacity between the first battery profile (BP1) and the second battery profile (BP2) from the starting capacity (Qi) to the ending capacity (Qf).
[0064] The profile correction unit (120) can be configured to generate a plurality of correction profiles (CP) by calculating the voltage difference by capacity between each of a plurality of battery profiles (BP) and an overvoltage profile (OP).
[0065] Specifically, the profile correction unit (120) can remove the overvoltage profile (OP) from the battery profile (BP). For example, the profile correction unit (120) can generate a correction profile (CP) by calculating the difference between the voltage of the battery profile (BP) and the overvoltage of the overvoltage profile (OP) for the same capacity, by capacity. In other words, the correction profile (CP) is a profile from which the overvoltage profile (OP) is removed from the battery profile (BP).
[0066] FIG. 3 is a schematic diagram illustrating a battery profile (BP) according to one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a correction profile (CP) according to one embodiment of the present invention.
[0067] Specifically, the battery profile (BP) of FIG. 3 is a profile obtained when the battery to be diagnosed is discharged at the target C-rate from the starting capacity (Qi) to the ending capacity (Qf).
[0068] Referring to FIGS. 2 to 4, the profile correction unit (120) can generate the correction profile (CP) of FIG. 4 by removing the overvoltage profile (OP) of FIG. 2 from the battery profile (BP) of FIG. 3. Here, the target C-rate corresponding to the battery profile (BP) of FIG. 3 and the target C-rate corresponding to the overvoltage profile (OP) of FIG. 2 are the same. That is, the correction profile (CP) can be generated based on the battery profile (BP) and the overvoltage profile (OP) for the same target C-rate.
[0069] The profile correction unit (120) can be configured to adjust a preset reference positive electrode profile and a reference negative electrode profile to correspond to each of a plurality of correction profiles (CP), thereby generating an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to each battery.
[0070] A reference anode profile is a profile that represents the correspondence between the capacity and voltage of a reference anode cell preset to correspond to the anode of a battery. For example, the reference anode cell may be the anode of a bipolar coin half cell or a three-electrode cell.
[0071] Additionally, the reference negative profile is a profile indicating the correspondence between the capacity and voltage of a reference negative cell preset to correspond to the negative electrode of a battery. For example, the reference negative cell may be the negative electrode of a coin half-cell or a three-electrode cell.
[0072] For example, the profile correction unit (120) can adjust the reference positive profile and the reference negative profile to correspond to the correction profile (CP). That is, the profile correction unit (120) can adjust the reference positive profile and the reference negative profile to generate an adjusted positive profile and an adjusted negative profile.
[0073] Next, the profile correction unit (120) can generate a comparison full-cell profile from the adjusted positive electrode profile and the adjusted negative electrode profile. The profile correction unit (120) can repeatedly adjust the reference positive electrode profile and the reference negative electrode profile until the comparison full-cell profile corresponds to the correction profile (CP).
[0074] For example, the profile correction unit (120) can generate a plurality of comparison full-cell profiles by shifting or capacity scaling the reference positive electrode profile and the reference negative electrode profile, and can specify a comparison full-cell profile among the plurality of comparison full-cell profiles that has the smallest error with respect to the correction profile (CP). Then, an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the specified comparison full-cell profile can be determined.
[0075] A specific embodiment in which the profile correction unit (120) determines the adjusted positive electrode profile and the adjusted negative electrode file of the battery to be diagnosed by adjusting the reference positive electrode profile and the reference negative electrode profile so that they correspond to the correction profile (CP) will be described again with reference to FIGS. 15 to 22 below.
[0076] The control unit (130) may be configured to extract diagnostic factors that serve as a basis for diagnosis from at least one of the adjusted positive electrode profile and the adjusted negative electrode profile of the battery to be diagnosed. For example, the control unit (130) may extract one or two or more of the negative electrode starting potential value, the negative electrode ending potential value, the negative electrode change ratio, the positive electrode loading amount, and the NP ratio from the adjusted negative electrode profile as diagnostic factors, and may diagnose the state of the battery to be diagnosed based on the extracted diagnostic factors.
[0077] As will be described further below, the control unit (130) can extract a diagnostic factor related to the positive pole from the adjusted positive pole profile. Furthermore, the control unit (130) can extract a diagnostic factor related to the negative pole from the adjusted negative pole profile. Furthermore, the control unit (130) can extract a diagnostic factor related to both the positive and negative poles by considering both the positive and negative pole diagnostic factors.
[0078] For example, the control unit (130) may extract a plurality of diagnostic factors corresponding to each of the plurality of batteries based on the adjusted positive polarity profile and / or the adjusted negative polarity profile corresponding to each of the plurality of batteries. In this case, the control unit (130) may extract the same type of diagnostic factor for each battery.
[0079] The control unit (130) may be configured to diagnose the status of multiple batteries based on the extracted multiple diagnostic factors.
[0080] Specifically, since multiple diagnostic factors can be represented by values of the same type, the control unit (130) can generate a distribution diagram representing the distribution of diagnostic factor values of the multiple diagnostic factors. Furthermore, the control unit (130) can determine a critical range of values that the diagnostic factors of a normal battery can have based on the generated distribution diagram.
[0081] As a result, the control unit (130) can further shorten the diagnosis time by performing the diagnosis through a simplified process of comparing the diagnostic factor value of the battery to be diagnosed with the above-mentioned critical range.
[0082] FIG. 5 is a diagram schematically illustrating the distribution of diagnostic factors according to one embodiment of the present invention. Specifically, FIG. 5 is a diagram illustrating an embodiment in which the distribution of multiple diagnostic factors follows a normal distribution.
[0083] As illustrated in FIG. 5, the control unit (130) determines a critical range (TH) of values that a diagnostic factor of a normal battery can have by using a statistical analysis method, compares the diagnostic factor value of the battery to be diagnosed with the critical range (TH), and diagnoses the state of the battery to be diagnosed as normal or abnormal based on the comparison result.
[0084] For example, the control unit (130) may be configured to select a diagnostic factor that falls outside the critical range (TH) among the plurality of diagnostic factors by considering the distribution of the plurality of diagnostic factors, and to diagnose the state of the battery corresponding to the selected diagnostic factor as abnormal. Conversely, the control unit (130) may be configured to select a diagnostic factor that falls within the critical range (TH) among the plurality of diagnostic factors, and to diagnose the state of the battery corresponding to the selected diagnostic factor as normal.
[0085] For example, if the mean value of the diagnostic factor is m and the standard deviation is σ, the critical range (TH) can be determined as a range greater than or equal to m-2σ and less than or equal to m+2σ. The control unit (130) can divide a plurality of diagnostic factors into diagnostic factors that fall within the critical range (TH) and diagnostic factors that do not fall within the critical range (TH).
[0086] Next, the control unit (130) can diagnose the state of the battery corresponding to a diagnostic factor belonging to the critical range (TH) as normal, and can diagnose the state of the battery corresponding to a diagnostic factor not belonging to the critical range (TH) as abnormal.
[0087] In the above, for the convenience of explanation, an example of a critical range (TH) set based on 2σ has been described, but it should be noted that the critical range (TH) is not limited to a range of m-2σ or more and m+2σ or less.
[0088] As described above, when a diagnosis is performed on new batteries after the critical range (TH) of values that the diagnostic factors of a normal battery can have is determined, the control unit (130) can quickly diagnose the status of the new batteries through a simplified process of comparing the diagnostic factor values of the new batteries with the critical range (TH).
[0089] Since the battery diagnosis device (100) according to the present invention diagnoses the state of the battery based on the correction profile (CP) in which the overvoltage is removed from the battery profile (BP), it has the advantage that charging and discharging by the current of the reference C-rate is not forced in order to diagnose the state of the battery. That is, since the state of the battery can be diagnosed even when the battery is charged and discharged by the current of the C-rate different from the reference C-rate, for example, the current of the C-rate higher than the reference C-rate, the state of the battery can be quickly diagnosed without restrictions on the charge and discharge conditions.
[0090] In addition, the battery diagnostic device (100) has the advantage of being able to quickly distinguish between normal batteries and abnormal batteries by relatively comparing the states of multiple batteries based on the distribution of multiple diagnostic factors.
[0091] Meanwhile, the control unit (130) included in the battery diagnostic device (100) may include a general-purpose processor or an ASIC (Application-Specific Integrated Circuit) known in the art to execute various control logics performed in the present invention, and may optionally further include a chipset, a logic circuit, a register, a memory, a communication modem, etc. In addition, when the control logic is implemented in software, the control unit (130) may be implemented as a set of program modules. At this time, the program modules may be stored in a memory and executed by the control unit (130). The memory may be included in the control unit (130) or may be located outside the control unit (130) and connected to the control unit (130) by wire and / or wirelessly.
[0092] In addition, the battery diagnostic device (100) may further include a storage unit (140). The storage unit (140) may store data or programs required for each component of the battery diagnostic device (100) to perform operations and functions, or data generated in the process of performing operations and functions. The storage unit (140) is not particularly limited in type as long as it is a known information storage means known to be capable of recording, deleting, updating, and reading data. As an example, the information storage means may optionally include RAM, ROM, EEPROM, flash memory, registers, etc. In addition, the storage unit (140) may store program codes defining processes executable by the control unit (130).
[0093] For example, the storage unit (140) can store a plurality of battery profiles (BP), an overvoltage profile (OP), a plurality of correction profiles (CP), a reference positive profile, a reference negative profile, an adjusted positive profile, an adjusted negative profile, and a plurality of diagnostic factor values.
[0094] In one embodiment, the storage unit (140) may store overvoltage profiles (OP) that represent overvoltages by capacity of the reference battery that occur when the reference battery is charged or discharged at a C-rate different from the target C-rate.
[0095] That is, the storage unit (140) can store a plurality of overvoltage profiles (OP) each corresponding to various C-rates that can be applied to charging or discharging of the battery to be diagnosed. For example, the plurality of overvoltage profiles (OP) can include a first overvoltage profile (OP1) that can be used to correct a first battery profile obtained while the battery to be diagnosed is charged or discharged with a current of a first C-rate, and a second overvoltage profile (OP1) that can be used to correct a second battery profile obtained while the battery to be diagnosed is charged or discharged with a current of a second C-rate.
[0096] Additionally, overvoltage profiles (OP) for C-rates that were not experimentally obtained can be obtained and stored through interpolation or extrapolation between similar overvoltage profiles (OP). For example, if an overvoltage profile (OP) corresponding to 1C and an overvoltage profile (OP) corresponding to 1.2C are stored in advance, an overvoltage profile (OP) corresponding to 1.1C can be further obtained based on the difference between the two overvoltage profiles (OP).
[0097] In this case, the profile correction unit (120) may be configured to select an overvoltage profile (OP) corresponding to the target C-rate from among a plurality of pre-stored overvoltage profiles (OP) and generate the correction profile using the selected overvoltage profile.
[0098] Here, the target C-rate is the C-rate of the charge current or discharge current of the battery to be diagnosed. For example, if multiple battery profiles (BP) are acquired during the process of charging multiple batteries at 0.3C, the target C-rate is 0.3C. The profile correction unit (120) can select an overvoltage profile (OP) corresponding to 0.3C from among the multiple overvoltage profiles (OP).
[0099] The profile correction unit (120) can be configured to generate a plurality of correction profiles (CP) using the selected overvoltage profile (OP).
[0100] For example, the profile correction unit (120) can generate a plurality of correction profiles (CP) by calculating the difference between each of a plurality of battery profiles (BP) and a selected overvoltage profile (OP). That is, the profile correction unit (120) can obtain a plurality of correction profiles (CP) from which overvoltage is commonly removed.
[0101] Since overvoltage corresponds to noise, the current state of the battery may not be accurately reflected in the battery profile (BP) including the overvoltage. Therefore, the battery management device according to one embodiment of the present invention can remove the overvoltage included in the battery profile (BP) using the overvoltage profile (OP) corresponding to the target C-rate. In other words, the battery management device has the advantage of being able to more accurately diagnose the state of the battery based on the compensation profile (CP) from which the overvoltage has been removed.
[0102] In one embodiment, the storage unit (140) may store in advance a plurality of overvoltage profiles (OPa) corresponding to the C-rate of the charging current (hereinafter, charging overvoltage profiles (OPa)) and a plurality of overvoltage profiles (OPb) corresponding to the C-rate of the discharging current (hereinafter, discharging overvoltage profiles (OPb)). In this case, the plurality of charging overvoltage profiles (OPa) and the plurality of discharging overvoltage profiles (OPb) may be stored independently.
[0103] Typically, batteries exhibit hysteresis during charge and discharge, so even at the same voltage, the charge and discharge capacities can differ. Therefore, to more accurately diagnose a battery's condition, it is desirable to store the overvoltage profile corresponding to the charge current C-rate and the overvoltage profile corresponding to the discharge current C-rate separately.
[0104] Meanwhile, the control unit (130) can determine a charge / discharge process (charge process or discharge process) corresponding to the battery profile (BP). For example, the control unit (130) can determine the charge / discharge process of the battery profile (BP) by comparing the size of the start capacity and the end capacity. In addition, the control unit (130) can select a corresponding overvoltage profile (OP) based on the determined charge / discharge process and the target C-rate.
[0105] A battery diagnosis device (100) according to one embodiment of the present invention can more accurately diagnose the status of multiple batteries by selecting an overvoltage profile (OP) considering a target C-rate and a charge / discharge process.
[0106] Meanwhile, the profile correction unit (120) can generate a comparison full-cell profile corresponding to the correction profile by adjusting a predetermined reference positive electrode profile and a reference negative electrode profile to mutually synthesize them, and can provide the reference negative electrode profile adjusted to generate the comparison full-cell profile to the control unit (130) as the adjusted negative electrode profile.
[0107] Below, the diagnostic factors that the control unit (130) can extract from the adjusted positive electrode profile and / or the adjusted negative electrode profile are specifically described.
[0108] The control unit (130) may be configured to extract at least one of a positive electrode-related diagnostic factor based on an adjusted positive electrode profile, a negative electrode-related diagnostic factor based on an adjusted negative electrode profile, and a positive electrode-related diagnostic factor based on both an adjusted positive electrode profile and an adjusted negative electrode profile as a diagnostic factor.
[0109] Here, the adjusted positive electrode profile is the result of adjusting the reference positive electrode profile, and the adjusted negative electrode profile is the result of adjusting the reference negative electrode profile. As described above, the profile correction unit (120) can adjust the reference positive electrode profile and the reference negative electrode profile so that the comparative full-cell profile generated based on the reference positive electrode profile and the reference negative electrode profile corresponds to the correction profile (CP).
[0110] The cathode-related factors may include at least one of cathode starting potential, cathode ending potential, cathode change ratio and cathode loading of the battery based on the adjusted cathode profile.
[0111] The anode start potential is the starting potential of the adjusted anode profile, and the anode end potential is the ending potential of the adjusted anode profile. Specifically, the anode start potential is the potential value of the anode participation initiation point (pi) of the adjusted anode profile. The anode end potential is the potential value of the anode participation end point (pf) of the adjusted anode profile.
[0112] The anode change ratio (ps) may refer to the change ratio [%] of the adjusted anode profile with respect to the reference anode profile. Specifically, the anode change ratio (ps) may be the contraction ratio or expansion ratio of the adjusted anode profile with respect to the reference anode profile. For example, if the adjusted anode profile is contracted by 10% from the reference anode profile, the anode change ratio (ps) is 90%. Conversely, if the adjusted anode profile is expanded by 10% from the reference anode profile, the anode change ratio (ps) is 110%.
[0113] The anode loading refers to the amount of anode active material coated on the anode current collector. Since the adjusted anode profile is a profile indicating the current state of the battery's anode, the control unit (130) can calculate the anode loading based on the adjusted anode profile.
[0114] For example, the control unit (130) can calculate the anode loading amount by considering the anode change rate (ps), the preset reference anode capacity, and the preset reference area. Here, the reference anode capacity may refer to the capacity of the preset reference anode cell. In addition, the reference area may refer to the area of the preset reference anode cell. Specifically, the control unit (130) can calculate the anode loading amount using the following equation 1.
[0115] [Formula 1]
[0116] p_loading = (ps × Q rc ) / A pc
[0117] Here, p_loading represents the anode loading amount, and ps represents the anode change rate. Q rc represents the reference anode capacity, and A pc represents the reference area.
[0118] The cathode-related diagnostic factors may include at least one of the cathode starting potential, the cathode ending potential, the cathode change rate (ns) and the cathode loading of the battery based on the adjusted cathode profile.
[0119] The cathode start potential is the start potential of the adjusted cathode profile, and the cathode end potential is the end potential of the adjusted cathode profile. Specifically, the cathode start potential is the potential value of the cathode participation initiation point (ni) of the adjusted cathode profile. The cathode end potential is the potential value of the cathode participation end point (nf) of the adjusted cathode profile.
[0120] The cathode change ratio (ns) may refer to the change ratio [%] of the adjusted cathode profile with respect to the reference cathode profile. Specifically, the cathode change ratio (ns) may be a shrinkage ratio or an expansion ratio of the adjusted cathode profile with respect to the reference cathode profile. For example, if the adjusted cathode profile is contracted by 10% from the reference cathode profile, the cathode change ratio (ns) is 90%. Conversely, if the adjusted cathode profile is expanded by 10% from the reference cathode profile, the cathode change ratio (ns) is 110%.
[0121] The negative electrode loading refers to the amount of negative electrode active material coated on the negative electrode current collector. Since the corrected negative electrode profile is a profile indicating the current state of the negative electrode of the battery, the control unit (130) can calculate the negative electrode loading based on the corrected negative electrode profile. Specifically, the control unit (130) can calculate the negative electrode loading by considering the negative electrode change ratio, the preset reference negative electrode capacity, and the preset reference area. Here, the reference negative electrode capacity may refer to the capacity of the preset reference negative electrode cell. The reference area may refer to the area of the preset reference negative electrode cell. Specifically, the control unit (130) can calculate the negative electrode loading based on the negative electrode change ratio, the reference negative electrode capacity, and the reference area using the following Equation 2.
[0122] [Formula 2]
[0123] n_loading = (ns × Q ra ) / A pa
[0124] Here, n_loading represents the cathode loading amount, and ns represents the cathode change rate. Q ra represents the reference cathode capacity, and A pa represents the reference area.
[0125] The anode-cathode related factors may include the NP ratio, which can be calculated based on the anode loading and cathode loading.
[0126] Specifically, the NP ratio refers to the ratio of the cathode capacity to the anode capacity. For example, the control unit (130) can calculate the NP ratio using Equation 3 below.
[0127] [Formula 3]
[0128] np ratio = n-loading / p-loading
[0129] Here, np ratio is the NP ratio, p-loading is the anode loading according to Equation 1, and n-loading is the cathode loading according to Equation 2.
[0130] The battery diagnostic device (100) can extract at least one of the positive starting potential, positive ending potential, positive change ratio, positive loading amount, negative starting potential, negative ending potential, negative change ratio, and NP ratio as a diagnostic factor. In addition, the battery diagnostic device (100) can diagnose the state of multiple batteries as a normal state or an abnormal state based on the distribution map of each extracted diagnostic factor.
[0131] For example, a battery diagnostic device (100) according to one embodiment of the present invention can extract a cathode-related diagnostic factor or a positive cathode-related diagnostic factor from the above-described adjusted cathode profile to diagnose the state of the cathode, such as the manufacturing quality or capacity loss of the cathode among the electrodes of the battery, and perform a diagnosis based on the extracted diagnostic factor.
[0132] Figures 6 to 10 are diagrams showing the distribution of diagnostic factor values extracted from multiple batteries.
[0133] Specifically, Fig. 6 is a graph showing the distribution of negative starting potential values extracted from multiple batteries. Fig. 7 is a graph showing the distribution of negative ending potential values extracted from multiple batteries. Fig. 8 is a graph showing the distribution of negative change ratio values extracted from multiple batteries. Fig. 9 is a graph showing the distribution of negative loading values extracted from multiple batteries. Fig. 10 is a graph showing the distribution of NP ratio values extracted from multiple batteries. As explained above, when the mean value is m and the standard deviation is σ in each of Figs. 6 to 10, it is assumed that the critical range (TH) of the normal diagnosis factor value is determined as m±2σ.
[0134] The control unit (130) can diagnose the status of the plurality of batteries based on the distribution of the extracted diagnostic factors when specific types of diagnostic factors are extracted from the plurality of batteries.
[0135] Specifically, the control unit (130) can extract diagnostic factors related to items of interest from among predetermined battery diagnostic items from the batteries and diagnose the status of the batteries based on the extracted diagnostic factors. The items of interest are selected by a user or a preset program, and the control unit (130) can be configured to obtain information about the selected items of interest.
[0136] For example, if the item of interest is related to the state of the negative electrode, the control unit (130) can extract negative starting potential values from a plurality of adjusted negative electrode profiles for a plurality of batteries, respectively. Then, the control unit (130) can select a negative starting potential that falls outside the threshold range (TH) among the extracted negative starting potential values. That is, as illustrated in FIG. 6, the control unit (130) can select a negative starting potential that exceeds the upper limit (m+2σ) of the threshold range (TH) or is lower than the lower limit (m-2σ) of the threshold range (TH). Then, the control unit (130) can diagnose the state of the battery corresponding to the selected negative starting potential as an abnormal state. On the other hand, the control unit (130) can diagnose the states of the remaining batteries as normal states.
[0137] In this way, the battery diagnostic device (100) according to one embodiment of the present invention can extract diagnostic factors related to diagnostic items of interest and diagnose the state of the battery based on the extracted diagnostic factors. Therefore, the battery diagnostic device (100) can accurately diagnose the state of the battery based on a correction profile (CP) with overvoltage removed, and has the advantage of being able to diagnose the state of the battery for each detailed diagnostic item.
[0138] Below, an embodiment in which the profile correction unit (120) adjusts the reference positive electrode profile and the reference negative electrode profile is specifically described.
[0139] The profile correction unit (120) can be configured to generate a comparison full-cell profile based on a reference anode profile and a reference cathode profile.
[0140] Specifically, a comparison full-cell profile can be generated based on the voltage difference between the reference positive electrode profile and the reference negative electrode profile for each capacity. For example, it is assumed that the voltage of the reference positive electrode profile corresponding to any capacity x is Vp, and the voltage of the reference negative electrode profile is Vn. The voltage of the comparison full-cell profile corresponding to the capacity x can be calculated as "Vp-Vn". The profile correction unit (120) can generate the comparison full-cell profile by calculating the voltage difference between the reference positive electrode profile and the reference negative electrode profile for the entire capacity.
[0141] The profile correction unit (120) can be configured to generate an adjusted anode profile and an adjusted cathode profile by adjusting the reference anode profile and the reference cathode profile until the generated comparison full-cell profile corresponds to the correction profile (CP).
[0142] Specifically, the profile correction unit (120) can calculate the error between the comparison full-cell profile and the correction profile (CP). In addition, the profile correction unit (120) can adjust the reference positive electrode profile and the reference negative electrode profile until the error between the comparison full-cell profile and the correction profile (CP) becomes minimal. When the comparison full-cell profile that minimizes the error with the correction profile (CP) is determined, the adjusted positive electrode profile and the adjusted negative electrode profile, which are the basis of the determined comparison full-cell profile, can be estimated as the positive electrode profile and the negative electrode profile that represent the current state of the battery.
[0143] Current technology has a problem in that it is impossible to directly obtain the positive and negative profiles representing the current state of a battery without disassembling the battery. Therefore, the present invention uses the adjusted positive and negative profiles, which serve as the basis for the comparative full-cell profile determined through the aforementioned adjustment process, as the positive and negative profiles that reflect the current state of the battery.
[0144] Hereinafter, with reference to FIGS. 11 to 18, an embodiment in which the profile correction unit (120) adjusts the reference positive electrode profile and the reference negative electrode profile will be described in more detail.
[0145] Figures 11 to 18 are diagrams illustrating a process for adjusting a reference anode profile and a reference cathode profile according to one embodiment of the present invention. Hereinafter, for convenience of explanation, a correction profile (CP) according to one embodiment of the present invention is referred to as a measurement full-cell profile (M).
[0146] Fig. 11 is a graph for reference in explaining an example of each of a reference positive electrode profile (Rp) and a reference negative electrode profile (Rn). In the graph of Fig. 15, the horizontal axis (X-axis) represents capacity (Ah) and the vertical axis (Y-axis) represents voltage (V).
[0147] Fig. 12 is a graph used as a reference to explain an example of a measured full cell profile (M) of a target battery. In the graph of Fig. 12, the horizontal axis (X-axis) represents capacity (capacity, Ah) and the vertical axis (Y-axis) represents voltage (voltage, V).
[0148] The profile correction unit (120) 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 a result of synthesizing an adjusted positive electrode profile and an adjusted negative electrode profile based on each of the reference positive electrode profile (Rp) and the reference negative electrode profile (Rn) stored in the storage unit (140).
[0149] That is, when the reference full-cell profile (R) is the result of subtracting a portion of the reference cathode profile (Rn) from a portion of the reference anode profile (Rp), the comparison full-cell profile can be said to be the result of subtracting a portion of the adjusted cathode profile from a portion of the adjusted anode profile.
[0150] The profile correction unit (120) can generate at least one comparative full-cell profile by directly adjusting the reference anode profile (Rp) and the reference cathode profile (Rn). Alternatively, at least one comparative full-cell profile can be secured in advance based on the reference anode profile (Rp) and the reference cathode profile (Rn) and stored in the storage unit (140). In this case, the profile correction unit (120) can obtain the comparative full-cell profile from the storage unit (140).
[0151] The profile correction unit (120) can generate multiple comparison full-cell profiles from the reference anode profile (Rp) and the reference cathode profile (Rn) by repeating the adjustment procedure of adjusting each of the reference anode profile (Rp) and the reference cathode profile (Rn) to several levels and then synthesizing them. The comparison full-cell profile may also be referred to as an 'adjusted reference full-cell profile'.
[0152] The profile correction unit (120) can specify a specific comparison full-cell profile among a plurality of comparison full-cell profiles that has the smallest error with respect to the measured full-cell profile (M).
[0153] Next, the profile correction unit (120) can determine an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to a specified comparison full-cell profile, as a positive electrode profile and a negative electrode profile representing the current state of the battery. In the following, it is noted that the positive electrode profile is the finally determined adjusted positive electrode profile, and the negative electrode profile is the finally determined adjusted positive electrode profile.
[0154] In this regard, various methods known at the time of filing of the present invention can be employed to determine the error between two profiles, each expressible in a two-dimensional coordinate system. For example, the absolute integral of the area between the two profiles or the Root Mean Square Error (RMSE) can be used as the error between the two profiles.
[0155] According to this configuration of the present invention, various state information about the battery can be obtained based on the finally determined positive and negative electrode profiles. The finally determined positive and negative electrode profiles correspond to a comparative full-cell profile that most closely resembles the measured full-cell profile. In other words, the comparative full-cell profile generated by synthesizing the finally determined positive and negative electrode profiles can be said to be nearly identical to the measured full-cell profile (M) in terms of shape, etc.
[0156] Therefore, according to the present invention, the positive electrode profile and negative electrode profile of the battery can be obtained without disassembling the battery.
[0157] If the battery is new, the battery's positive and negative profiles can be analyzed to diagnose whether the battery is defective and, if so, what type of defect it is.
[0158] Additionally, if the battery is already in use, the battery's positive and negative profiles can be used to determine the extent to which the battery has deteriorated for each deterioration item.
[0159] Furthermore, according to the present invention, the positive electrode profile and the negative electrode profile of the battery can be obtained through a simple process. The present invention can be implemented even if only one reference positive electrode profile (Rp) and one reference negative electrode profile (Rn) are stored in the storage unit (140). That is, there is no need to store multiple reference positive electrode profiles (Rp) and / or multiple reference negative electrode profiles (Rn) in the storage unit (140). Accordingly, there is no need for the storage capacity of the storage unit (140) to be high, and there is no need to conduct numerous preliminary tests required to secure multiple reference positive electrode profiles (Rp) and / or multiple reference negative electrode profiles (Rn).
[0160] FIGS. 13 to 15 are drawings for reference in explaining an example of a procedure for generating a comparison full-cell profile used for comparison with a measurement full-cell profile (M) according to one embodiment of the present invention.
[0161] The procedure for generating a comparative full-cell profile, which will be described with reference to FIGS. 13 to 15, proceeds in the following order: a first process (see FIG. 17) for setting four points (positive participation start point, positive participation end point, negative participation start point, negative participation end point) to correspond to a voltage range of interest, a second process (see FIG. 18) for performing a profile shift, and a third process (see FIG. 19) for performing capacity scaling. That is, the procedure for generating a comparative full-cell profile according to one embodiment of the present invention includes the first to third processes.
[0162] First, referring to Fig. 13, the reference anode profile (Rp) and the reference cathode profile (Rn) are the same as those shown in Fig. 11.
[0163] The profile correction unit (120) determines the positive participation start point (pi), the positive participation end point (pf), the negative participation start point (ni), and the negative participation end point (nf) on the reference positive profile (Rp) and the reference negative profile (Rn).
[0164] Either the positive engagement initiation point (pi) or the negative engagement initiation point (ni) depends on the other.
[0165] For example, the profile correction unit (120) may divide the anode voltage range from the starting point to the ending point (or the second set voltage) of the reference anode profile (Rp) into a plurality of micro-voltage sections, and then set the boundary points of two adjacent micro-voltage sections among the plurality of micro-voltage sections as anode participation start point (pi). Each micro-voltage section may have a predetermined size (e.g., 0.01 V). Then, the profile correction unit (120) may set a point on the reference cathode profile (Rn) that is smaller than the anode participation start point (pi) by the first set voltage (e.g., 3 V) as a cathode participation start point (ni).
[0166] As another example, the profile correction unit (120) may divide the negative voltage range from the start point to the end point of the reference negative profile (Rn) into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as the negative participation start point (ni). Then, the profile correction unit (120) may search for a point that is greater than the negative participation start point (ni) by a first set voltage from the reference positive profile (Rp), and set the searched point as the positive participation start point (pi).
[0167] Additionally, either the positive engagement end point (pf) or the negative engagement end point (nf) depends on the other.
[0168] For example, the profile correction unit (120) may divide the voltage range from the second set voltage to the end point of the reference positive electrode profile (Rp) into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as the positive electrode participation end point (pf). Then, the profile correction unit (120) may set the point on the reference negative electrode profile (Rn) that is smaller by the second set voltage (e.g., 4 V) than the positive electrode participation end point (pf) as the negative electrode participation end point (nf).
[0169] As another example, the profile correction unit (120) may divide the negative voltage range from the start point to the end point of the reference negative profile (Rn) into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a negative participation end point (nf). Then, the profile correction unit (120) may search for a point from the reference positive profile (Rp) that is greater than the negative participation end point (nf) by a second set voltage, and set the searched point as the positive participation end point (pf).
[0170] In this way, when the determination of the positive participation start point (pi), the positive participation end point (pf), the negative participation start point (ni), and the negative participation end point (nf) is completed, the profile correction unit (120) shifts at least one of the reference positive profile (Rp) and the reference negative profile (Rn) to the left or right along the horizontal axis (capacity axis).
[0171] Referring to FIG. 14, the profile correction unit (120) can shift the reference anode profile (Rp) and / or the reference cathode profile (Rn) so that the capacitance values of the anode participation start point (pi) and the cathode participation start point (ni) match.
[0172] Alternatively, the profile correction unit (120) can shift the reference anode profile (Rp) and / or the reference cathode profile (Rn) so that the voltages of the anode participation end point (pf) and the cathode participation end point (nf) match.
[0173] Figure 14 illustrates a situation where only the reference anode profile (Rp) is shifted to the left to generate an adjusted reference anode profile (Rp'), resulting in the voltage of the anode engagement initiation point (pi') matching the voltage of the cathode engagement initiation point (ni). The adjusted reference anode profile (Rp') is the result of applying an adjustment procedure to the reference anode profile (Rp) that shifts to the left by the voltage difference between the anode engagement initiation point (pi) and the cathode engagement initiation point (ni). Therefore, the two points (pi, pi') differ only in capacitance and have the same voltage. The two points (pf, pf') differ only in capacitance and have the same voltage.
[0174] When the adjustment result profiles (Rp', Rn) in which at least one of the reference positive profile (Rp) and the reference negative profile (Rn) is shifted are secured, the profile correction unit (120) scales the capacity range of at least one of the adjustment result profiles (Rp', Rn).
[0175] According to the example illustrated in FIG. 14, the profile correction unit (120) performs an additional adjustment procedure to contract or expand at least one of the adjusted reference anode profile (Rp') and the reference cathode profile (Rn) along the horizontal axis (capacity axis).
[0176] Referring to FIG. 15, the profile correction unit (120) can generate an adjusted reference anode profile (Rp') by shrinking or expanding the adjusted reference anode profile (Rp') so that the size of the capacity range between two points (pi', pf') of the adjusted reference anode profile (Rp') matches the size of the capacity range of the measured full-cell profile (M). At this time, one of the two points (pi', pf') can be fixed. Accordingly, the capacity difference between the two points (pi', pf'') of the adjusted reference anode profile (Rp'') can match the size of the capacity range of the measured full-cell profile (M).
[0177] In addition, the profile correction unit (120) can generate an adjusted reference cathode profile (Rn') by shrinking or expanding the reference cathode profile (Rn) so that the size of the capacity range between two points (ni, nf) of the reference cathode profile (Rn) matches the size of the capacity range of the measured full-cell profile (M). At this time, one of the two points (ni, nf) can be fixed. Accordingly, the capacity difference between the two points (ni, nf') of the adjusted reference cathode profile (Rn') can match the capacity range of the measured full-cell profile (M).
[0178] In Fig. 15, the adjusted reference anode profile (Rp'') is a result of shrinking the adjusted reference anode profile (Rp') shown in Fig. 14, and the adjusted reference cathode profile (Rn') is a result of expanding the reference cathode profile (Rn) shown in Fig. 14.
[0179] The positive participation endpoint (pf'') on the adjusted reference positive profile (Rp'') corresponds to the positive participation endpoint (pf) on the adjusted reference positive profile (Rp'). The negative participation endpoint (nf') on the adjusted reference negative profile (Rn') corresponds to the negative participation endpoint (nf) on the reference negative profile (Rn).
[0180] The capacity difference between the positive engagement start point (pi') and the positive engagement end point (pf'') of the adjusted reference positive electrode profile (Rp'') corresponds to the size of the capacity range of the measured full-cell profile (M). Similarly, the capacity difference between the negative engagement start point (ni) and the negative engagement end point (nf') of the adjusted reference negative electrode profile (Rn') corresponds to the size of the capacity range of the measured full-cell profile (M).
[0181] In addition, the capacity difference between the two points (pi', pf'') of the adjusted reference positive electrode profile (Rp'') matches the capacity difference between the two points (ni, nf') of the adjusted reference negative electrode profile (Rn'). The profile correction unit (120) can generate a comparison full-cell profile (S) by subtracting the part between the two points (ni, nf') of the adjusted reference negative electrode profile (Rn') from the part between the two points (pi', pf'') of the adjusted reference positive electrode profile (Rp'').
[0182] The profile correction unit (120) can calculate the error (profile error) between the comparison full-cell profile (S) and the measurement full-cell profile (M). When the error between the comparison full-cell profile (S) and the measurement full-cell profile (M) is minimized, the adjusted reference anode profile (Rp'') corresponding to the comparison full-cell profile (S) can be determined as the adjusted anode profile, and the adjusted reference cathode profile (Rn') can be determined as the adjusted cathode profile.
[0183] The profile correction unit (120) can record in the storage unit (140) at least two of the adjusted reference positive electrode profile (Rp''), the adjusted reference negative electrode profile (Rn'), the positive electrode participation start point (pi'), the positive electrode participation end point (pf''), the negative electrode participation start point (ni), the negative electrode participation end point (nf'), the first scale factor, the second scale factor, the comparison full-cell profile (S), and the profile error by mutually mapping them. Here, the first scale factor can represent the ratio of the capacity difference between two points (pi', pf'') to the capacity difference between two points (pi0, pf0). The second scale factor can represent the ratio of the capacity difference between two points (ni, nf') to the capacity difference between two points (ni0, nf0).
[0184] In addition, the profile correction unit (120) can calculate the positive change ratio (ps) of the adjusted reference positive profile (Rp'') with respect to the reference positive profile (Rp). And, the profile correction unit (120) can calculate the negative change ratio (ns) of the adjusted reference positive profile (Rn') with respect to the reference negative profile (Rn). In this case, the profile correction unit (120) can determine the first scale factor as the positive change ratio (ps) and the second scale factor as the negative change ratio (ns).
[0185] Meanwhile, as described above, when the anode voltage range of the reference anode profile (Rp) is divided into a plurality of micro-voltage sections, the boundary points of two adjacent micro-voltage sections among the plurality of micro-voltage sections can be set as the anode participation start point (pi).
[0186] For example, if the anode voltage range of the reference anode profile (Rp) is divided into 100 microvoltage ranges, there may be 100 boundary points that can be set as anode participation start points (pi). Furthermore, if the voltage range that is higher than the second set voltage in the reference anode profile (Rp) is divided into 40 microvoltage ranges, there may be 40 boundary points that can be set as anode participation end points (pf). In this case, up to 4,000 different comparison full-cell profiles can be generated.
[0187] Of course, those skilled in the art will easily understand that as the size of the micro-voltage section decreases, the number of comparative full-cell profiles that can be generated at maximum increases, and conversely, as the size of the micro-voltage section increases, the number of comparative full-cell profiles that can be generated at maximum decreases.
[0188] The profile correction unit (120) can identify the minimum value among the profile errors of the plurality of comparative full-cell profiles generated as described above, and then obtain information mapped to the minimum profile error (e.g., at least one of the positive engagement start point (pi), the positive engagement end point (pf), the negative engagement start point (ni), the negative engagement end point (nf), the positive change rate (ps), the negative change rate (ns), and the capacity ratio between the positive and negative electrodes) from the storage unit (140).
[0189] FIGS. 16 to 18 are drawings for reference in explaining another example of a procedure for generating a comparison full-cell profile used for comparison with a measurement full-cell profile (M) according to one embodiment of the present invention.
[0190] For reference, the embodiments according to FIGS. 16 to 18 are independent of the embodiments according to FIGS. 13 to 15. Therefore, terms or symbols commonly described in describing the embodiments according to FIGS. 13 to 15 and the embodiments according to FIGS. 16 to 18 should be understood as being limited to each embodiment.
[0191] The procedure for generating a comparative full-cell profile, which will be described with reference to FIGS. 16 to 18, proceeds in the following order: a fourth process for performing capacity scaling (see FIG. 16), a fifth process for setting four points (positive electrode participation start point, positive electrode participation end point, negative electrode participation start point, negative electrode participation end point), and a sixth process for performing profile shifting (see FIG. 18). That is, the procedure for generating a comparative full-cell profile according to another embodiment of the present invention includes the fourth to sixth processes.
[0192] First, referring to Fig. 16, the reference anode profile (Rp) and the reference cathode profile (Rn) are the same as those shown in Fig. 11.
[0193] The profile correction unit (120) applies a first scale factor and a second scale factor selected from a scaling value range to the reference anode profile (Rp) and the reference cathode profile (Rn), respectively, to generate an adjusted reference anode profile (Rp') and an adjusted reference cathode profile (Rn').
[0194] The scaling value range may be predetermined or may vary depending on the ratio of the size of the capacity range of the measured full-cell profile (M) to the size of the capacity range of the reference full-cell profile (R). For example, when values spaced by 0.1% of the scaling value range (e.g., 90-99%) (i.e., 90%, 90.1%, 90.2%, … 98.9%, 99%) can be selected as the first scale factor and the second scale factor, 91 values can be selected as the first scale factor and the second scale factor, respectively. In this case, a maximum of 8,281 adjusted profile pairs can be generated according to 91×91=8,281 adjustment levels (combinations of the first scale factor and the second scale factor). An adjusted profile pair means a combination of an adjusted reference positive profile and an adjusted reference negative profile.
[0195] The adjusted reference anode profile (Rp') and the adjusted reference cathode profile (Rn') illustrated in FIG. 16 illustrate the results of applying a first scale factor and a second scale factor, which are less than 100%, to the reference anode profile (Rp) and the reference cathode profile (Rn), respectively.
[0196] Since the first scale factor and the second scale factor are less than 100%, the adjusted reference anode profile (Rp') is the reference anode profile (Rp) shrunk along the horizontal axis, and the adjusted reference cathode profile (Rn') is also the reference cathode profile (Rn) shrunk along the horizontal axis. To facilitate understanding, the starting points of each of the anode profile (Rp) and the reference cathode profile (Rn) are fixed, and only the remaining portion is shrunk to the left along the horizontal axis.
[0197] Referring to FIG. 17, the profile correction unit (120) determines the positive participation start point (pi'), the positive participation end point (pf'), the negative participation start point (ni'), and the negative participation end point (nf') on the adjusted reference positive profile (Rp') and the adjusted reference negative profile (Rn').
[0198] Either the positive engagement start point (pi') or the negative engagement start point (ni') may depend on the other. Furthermore, either the positive engagement end point (pf') or the negative engagement end point (nf') may depend on the other. Furthermore, either the positive engagement start point (pi') or the positive engagement end point (pf') may be set based on the other.
[0199] That is, when any one of the positive engagement start point (pi'), positive engagement end point (pf'), negative engagement start point (ni') and negative engagement end point (nf') is set, the remaining three points can be automatically set by the size of the capacity range of the first set voltage, the second set voltage and / or the measured full cell profile (M) (e.g., charge capacity of 0 to 100% of SOC).
[0200] For example, the profile correction unit (120) may divide the anode voltage range from the starting point to the ending point (or the second set voltage) of the adjusted reference anode profile (Rp') into a plurality of micro-voltage sections, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as the anode participation start point (pi'). Then, the profile correction unit (120) may set the point on the adjusted reference cathode profile (Rn) that is smaller by the first set voltage (e.g., 3 V) than the anode participation start point (pi') as the cathode participation start point (ni').
[0201] As another example, the profile correction unit (120) may divide the negative voltage range from the start point to the end point of the adjusted reference negative profile (Rn') into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a negative participation start point (ni'). Then, the profile correction unit (120) may search for a point from the reference positive profile (Rp) that is larger by a first set voltage than the negative participation start point (ni'), and set the searched point as the positive participation start point (pi').
[0202] As another example, the profile correction unit (120) may divide the voltage range from the second set voltage to the end point of the adjusted reference positive profile (Rp') into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as the positive participation end point (pf'). Then, the profile correction unit (120) may search for a point in the adjusted reference negative profile (Rn') that is smaller than the positive participation end point (pf') by the second set voltage (e.g., 4 V), and set the searched point as the negative participation end point (nf').
[0203] As another example, the profile correction unit (120) may divide the negative voltage range from the start point to the end point of the adjusted reference negative profile (Rn') into a plurality of micro-voltage sections of a predetermined size, and then set the boundary point of two adjacent micro-voltage sections among the plurality of micro-voltage sections as a negative participation end point (nf'). Then, the profile correction unit (120) may search for a point that is larger than the negative participation end point (nf') by a second set voltage from the adjusted reference positive profile (Rp'), and set the searched point as the positive participation end point (pf').
[0204] The profile correction unit (120) can additionally determine the remaining three points based on the determined point when one of the positive participation start point (pi'), positive participation end point (pf'), negative participation start point (ni'), and negative participation end point (nf') is determined.
[0205] For example, if the positive participation start point (pi') is first determined, the profile correction unit (120) can set a point on the adjusted reference positive profile (Rp') that has a capacity value that is greater than the capacity value of the positive participation start point (pi') by the size of the capacity range of the measured full-cell profile (M) as the positive participation end point (pf'). In addition, the profile correction unit (120) can search for a point that is lower than the positive participation start point (pi') by a first set voltage from the adjusted reference negative profile (Rn') and set the searched point as the negative participation start point (ni'). In addition, the profile correction unit (120) can set a point on the adjusted reference negative profile (Rn') that has a capacity value that is greater than the capacity value of the negative participation start point (ni') by the size of the capacity range of the measured full-cell profile (M) as the negative participation end point (nf').
[0206] As another example, the profile correction unit (120) may set a point on the adjusted reference positive electrode profile (Rp') that has a capacity value that is smaller by the size of the capacity range of the measured full-cell profile (M) than the capacity value of the positive electrode participation end point (pf') when the positive electrode participation end point (pf') is first determined, as the positive electrode participation start point (pi'). In addition, the profile correction unit (120) may search for a point that is lower by a second set voltage than the positive electrode participation end point (pf') from the adjusted reference negative electrode profile (Rn'), and set the searched point as the negative electrode participation end point (nf'). In addition, the profile correction unit (120) may set a point on the adjusted reference negative electrode profile (Rn') that has a capacity value that is smaller by the size of the capacity range of the measured full-cell profile (M) than the capacity value of the negative electrode participation end point (nf') as the negative electrode participation start point (ni').
[0207] As another example, when the negative participation start point (ni') is determined, the profile correction unit (120) can set a point on the adjusted reference negative profile (Rn') that has a capacity value that is greater than the capacity value of the negative participation start point (ni') by the size of the capacity range of the measured full-cell profile (M) as the negative participation end point (nf'). In addition, the profile correction unit (120) can search for a point higher than the negative participation start point (ni') by a first set voltage from the adjusted reference positive profile (Rp') and set the searched point as the positive participation start point (pi'). In addition, the profile correction unit (120) can set a point on the adjusted reference positive profile (Rp') that has a capacity value that is greater than the capacity value of the positive participation start point (pi') by the size of the capacity range of the measured full-cell profile (M) as the positive participation end point (pf').
[0208] As another example, when the negative participation end point (nf') is determined, the profile correction unit (120) may set a point on the adjusted reference negative profile (Rn') that has a capacity value that is smaller by the size of the capacity range of the measured full-cell profile (M) than the capacity value of the negative participation end point (nf') as the negative participation start point (ni'). In addition, the profile correction unit (120) may search for a point higher by a second set voltage than the negative participation end point (nf') from the adjusted reference positive profile (Rp') and set the searched point as the positive participation end point (pf'). In addition, the profile correction unit (120) may set a point on the adjusted reference positive profile (Rp') that has a capacity value that is smaller by the size of the capacity range of the measured full-cell profile (M) than the capacity value of the positive participation end point (pf') as the positive participation start point (pi').
[0209] When the determination of the positive participation start point (pi'), the positive participation end point (pf'), the negative participation start point (ni'), and the negative participation end point (nf') is completed based on the pair of the first scale factor and the second scale factor, the profile correction unit (120) can shift at least one of the adjusted reference positive profile (Rp') and the adjusted reference negative profile (Rn') along the horizontal axis so that the capacity values of the positive participation start point (pi') and the negative participation start point (ni') match, or so that the capacity values of the positive participation end point (pf') and the negative participation end point (nf') match.
[0210] The adjusted reference cathode profile (Rn'') illustrated in Fig. 18 is only the adjusted reference cathode profile (Rn') illustrated in Fig. 17 shifted to the right. Accordingly, the capacity values of the positive participation start point (pi') and the negative participation start point (ni'') are matched with each other. In this regard, since the capacity difference between the positive participation start point (pi') and the positive participation end point (pf') is the same as the capacity difference between the negative participation start point (ni') and the negative participation end point (nf'), when the capacity values of the positive participation start point (pi') and the negative participation start point (ni'') are matched with each other, the capacity values of the positive participation end point (pf') and the negative participation end point (nf') also become matched with each other.
[0211] Referring to FIG. 18, the profile correction unit (120) can generate a comparison full-cell profile (U) by subtracting the partial profile between two points (pi', pf') of the adjusted reference positive profile (Rp') from the partial profile between two points (ni'', nf'') of the adjusted reference negative profile (Rn'').
[0212] The profile correction unit (120) can calculate the error (profile error) between the comparison full-cell profile (U) and the measurement full-cell profile (M). When the error between the comparison full-cell profile (U) and the measurement full-cell profile (M) is minimized, the adjusted reference anode profile (Rp') corresponding to the comparison full-cell profile (U) can be determined as the adjusted anode profile, and the adjusted reference cathode profile (Rn'') can be determined as the adjusted cathode profile.
[0213] The profile correction unit (120) can mutually map at least two of the adjusted reference positive profile (Rp'), the adjusted reference negative profile (Rn''), the positive participation start point (pi'), the positive participation end point (pf'), the negative participation start point (ni''), the negative participation end point (nf''), the positive change rate (ps), the negative change rate (ns), the comparison full-cell profile (U), and the profile error, and record them in the storage unit (140).
[0214] Here, the profile correction unit (120) can calculate the positive change ratio (ps) of the adjusted reference positive profile (Rp') with respect to the reference positive profile (Rp). In addition, the profile correction unit (120) can calculate the negative change ratio (ns) of the adjusted reference positive profile (Rn'') with respect to the reference negative profile (Rn). For example, the profile correction unit (120) can determine the first scale factor as the positive change ratio (ps) and the second scale factor as the negative change ratio (ns).
[0215] As described above, the profile correction unit (120) can generate a comparison full-cell profile corresponding to each pair of the first scale factor and the second scale factor selected from the scaling value range. Since there are multiple pairs of the first scale factor and the second scale factor, it is obvious that a plurality of comparison full-cell profiles will also be generated. The profile correction unit (120) can identify a minimum value among the profile errors of the multiple comparison full-cell profiles, and then obtain information mapped to the minimum profile error from the storage unit (140).
[0216] The battery diagnostic device (100) according to the present invention is connected to a display device (not shown) and can output information about a battery diagnosed as being in an abnormal state. This allows information about a battery diagnosed as being in an abnormal state to be displayed on the display device.
[0217] The battery diagnostic device (100) according to the present invention is connected to an alarm device (not shown) and can output information on a battery diagnosed as being in an abnormal state, thereby operating the alarm device.
[0218] The battery diagnosis device (100) according to the present invention can be applied to a BMS (Battery Management System). That is, the BMS according to the present invention can include the battery diagnosis device (100) described above. In this configuration, at least some of the components of the battery diagnosis device (100) can be implemented by supplementing or adding functions of the components included in a conventional BMS. For example, the profile acquisition unit (110), the profile correction unit (120), the control unit (130), and the storage unit (140) of the battery diagnosis device (100) can be implemented as components of the BMS.
[0219] In addition, the battery diagnostic device (100) according to the present invention may be installed in a battery pack. That is, the battery pack according to the present invention may include the battery diagnostic device (100) described above and one or more battery cells. In addition, the battery pack may further include electrical components (relays, fuses, etc.) and a case, etc.
[0220] FIG. 19 is a drawing illustrating an exemplary configuration of a battery pack according to another embodiment of the present invention.
[0221] As illustrated in FIG. 19, a battery pack (1) according to the present invention may include at least one battery (10), a measuring unit (20), and a battery diagnostic device (100) according to the present invention.
[0222] The positive terminal of the battery (10) can be connected to the positive terminal (P+) of the battery pack (1), and the negative terminal of the battery (10) can be connected to the negative terminal (P-) of the battery pack (1).
[0223] The measuring unit (20) can be connected to the positive terminal and negative terminal of the battery (10). In addition, the measuring unit (20) can measure the positive potential and negative potential of the battery (10) and calculate the difference between the positive potential and negative potential to measure the voltage of the battery (10).
[0224] And, the measuring unit (20) can be connected to a current measuring unit (A). For example, the current measuring unit (A) can be an ammeter or a shunt resistor capable of measuring the charging current and discharging current of the battery (10). The measuring unit (20) can measure the charging current of the battery (10) using the current measuring unit (A) to calculate the charging amount. In addition, the measuring unit (20) can measure the discharging current of the battery (10) through the third sensing line (SL3) to calculate the discharging amount.
[0225] For example, information about the voltage and capacity of the battery (10) measured by the measuring unit (20) can be transmitted to the profile acquisition unit (110). Then, the profile acquisition unit (110) can directly generate a battery profile (BP) based on the received information about the voltage and capacity.
[0226] As another example, information about the voltage and capacity of the battery (10) measured by the measuring unit (20) can be stored in the storage unit (140). When charging or discharging of the battery (10) is completed, the profile acquisition unit (110) can access the storage unit (140) to acquire the battery profile (BP).
[0227] As another example, the measuring unit (20) may directly generate a battery profile (BP) based on information regarding the voltage and capacity of the measured battery (10). In this case, the generated battery profile (BP) may be transmitted to the profile acquisition unit (110) and also stored in the storage unit (140).
[0228] A charging / discharging device or load can be connected to the positive terminal (P+) and negative terminal (P-) of the battery pack (1).
[0229] Figure 20 is a diagram illustrating a battery cell manufacturing process of a battery manufacturing system according to another embodiment of the present invention. Specifically, Figure 20 is a diagram schematically illustrating the activation process of a manufactured battery cell over time.
[0230] Referring to Figure 20, the aging process is performed in the first stage from time t0 to time t1. Here, the aging process refers to a process in which battery cells are left under specific conditions. In the first stage, an electrolyte may be impregnated into the battery electrodes.
[0231] The first charge is performed in the second stage from time t1 to time t2. In the second stage, a solid electrolyte interphase (SEI) layer can be formed on the cathode.
[0232] In the third stage, from time point t2 to time point t3, a high-temperature aging process is performed. For example, in the third stage, aging is performed at a high temperature of 60°C, and the film layer formed in the second stage can be stabilized.
[0233] The degasing process takes place in the fourth stage, from time t3 to time t4. During this stage, gases contained within the battery cells can be removed.
[0234] In the fifth stage, from time t4 to time t5, a charging process of the battery cell is performed. In the sixth stage, from time t5 to time t6, a discharging process of the battery cell is performed. Here, the fifth and sixth stages can be collectively referred to as a capacity inspection process of the battery cell. Generally, the sixth stage is a stage for detecting defects in a battery cell while discharging a fully charged battery cell, and is a process stage for discharging the battery cell at a discharge C-rate determined in consideration of the inspection time and inspection accuracy. For example, in the sixth stage, the battery cell is discharged at 0.3C, and a battery profile (BP) for capacity and voltage can be acquired during the discharge process. In addition, based on the acquired battery profile (BP), whether the battery cell is defective can be detected as described above.
[0235] In the 7th stage from time point t6 to time point t7, the shipping charging process for shipping the battery cells is carried out.
[0236] A battery diagnosis device (100) according to an embodiment of the present invention can obtain a battery profile (BP) generated in the discharge process of the sixth step. In addition, by removing the overvoltage included in the battery profile (BP) using the overvoltage profile (OP) corresponding to the target C-rate set in the discharge process, a correction profile (CP) for a plurality of battery cells can be obtained. In addition, the battery diagnosis device (100) can diagnose the status of a plurality of battery cells based on the plurality of correction profiles (CP). That is, the battery diagnosis device (100) can be used in the activation process step of the battery cell, thereby quickly and accurately diagnosing whether the manufactured battery cell is defective. In particular, since the battery diagnosis device (100) diagnoses the status of the battery cell after removing the overvoltage that may be included in the battery profile (BP) obtained in the capacity inspection process, it has the advantage of being able to detect defective battery cells more accurately.
[0237] FIG. 21 is a drawing showing an exemplary configuration of a vehicle according to another embodiment of the present invention.
[0238] Referring to FIG. 21, a battery pack according to an embodiment of the present invention may be included in a vehicle (1700), such as an electric vehicle (EV) or a hybrid vehicle (HV). Furthermore, the battery pack (1710) may drive the vehicle (1700) by supplying power to a motor via an inverter provided in the vehicle (1700). Here, the battery pack (1710) may include a battery management device (100). That is, the vehicle (1700) may include a battery management device (100).
[0239] FIG. 22 is a diagram schematically illustrating a battery diagnosis method according to another embodiment of the present invention.
[0240] The battery diagnosis method may include a profile acquisition step (S100), a correction profile generation step (S200), a profile adjustment step (S300), a diagnostic factor extraction step (S400), and a status diagnosis step (S500).
[0241] Preferably, each step of the battery diagnosis method can be performed by a battery diagnosis device (100). In the following, for convenience of explanation, any content that overlaps with the previously described content will be omitted or briefly described.
[0242] The profile acquisition step (S100) is a step of acquiring each of a plurality of battery profiles (BP) indicating the correspondence between the voltage and capacity of each of a plurality of batteries, and can be performed by the profile acquisition unit (110).
[0243] For example, the profile acquisition unit (110) can directly receive a battery profile (BP) from the outside. That is, the profile acquisition unit (110) can acquire a battery profile (BP) by being connected to the outside via wire and / or wirelessly and receiving the battery profile (BP).
[0244] As another example, the profile acquisition unit (110) can receive battery information regarding the voltage (V) and capacity (Q) of the battery. Furthermore, the profile acquisition unit (110) can generate a battery profile (BP) based on the received battery information. That is, the profile acquisition unit (110) can acquire the battery profile (BP) by directly generating the battery profile (BP) based on the battery information.
[0245] The correction profile generation step (S200) is a step of generating a plurality of correction profiles (CP) by correcting a plurality of battery profiles (BP) based on a preset overvoltage profile (OP), and can be performed by the profile correction unit (120).
[0246] Specifically, the profile correction unit (120) can remove the overvoltage profile (OP) from the battery profile (BP). For example, the profile correction unit (120) can calculate the difference between the voltage of the battery profile (BP) and the overvoltage of the overvoltage profile (OP) for the same capacity. The profile correction unit (120) can generate a correction profile (CP) by calculating the difference between the voltage of the battery profile (BP) and the overvoltage of the overvoltage profile (OP) at the full capacity.
[0247] The profile adjustment step (S300) is a step of adjusting a predetermined reference positive electrode profile and a reference negative electrode profile to correspond to each of a plurality of correction profiles (CP) to generate an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to each battery, and can be performed by the profile correction unit (120).
[0248] For example, the profile correction unit (120) can generate a plurality of comparison full-cell profiles by shifting or capacity scaling the reference positive electrode profile and the reference negative electrode profile, and can specify a comparison full-cell profile among the plurality of comparison full-cell profiles that has the smallest error with respect to the correction profile (CP). In addition, an adjusted positive electrode profile and an adjusted negative electrode profile corresponding to the specified comparison full-cell profile can be determined.
[0249] The diagnostic factor extraction step (S400) is a step of extracting a diagnostic factor for each battery from at least one of the adjusted positive electrode profile and the adjusted negative electrode profile, and can be performed by the control unit (130).
[0250] Specifically, when the control unit (130) wants to diagnose a battery condition related to the positive electrode, it can extract a diagnostic factor related to the positive electrode from the adjusted positive electrode profile. In addition, when the control unit (130) wants to diagnose a battery condition related to the negative electrode, it can extract a diagnostic factor related to the negative electrode from the adjusted negative electrode profile. In addition, when the control unit (130) wants to diagnose a battery condition related to both the positive and negative electrodes, it can extract a diagnostic factor related to the positive electrode from the adjusted positive electrode profile, and extract a diagnostic factor related to the negative electrode from the adjusted negative electrode profile.
[0251] In this case, the positive electrode-related factor may include at least one of the positive electrode starting potential, the positive electrode ending potential, the positive electrode change ratio, and the positive electrode loading amount of the battery based on the adjusted positive electrode profile. In addition, the negative electrode-related factor may include at least one of the negative electrode starting potential, the negative electrode ending potential, the negative electrode change ratio, and the negative electrode loading amount of the battery based on the adjusted negative electrode profile. The factor related to both the positive and negative electrodes may include the positive electrode loading amount and the NP ratio based on the negative electrode loading amount.
[0252] The status diagnosis step (S500) is a step of diagnosing the status of multiple batteries based on multiple extracted diagnostic factors, and can be performed by the control unit (130).
[0253] For example, the control unit (130) may be configured to select a diagnostic factor that falls outside the critical range (TH) among the plurality of diagnostic factors by considering the distribution of the plurality of diagnostic factors, and to diagnose the state of the battery corresponding to the selected diagnostic factor as abnormal. On the other hand, the control unit (130) may be configured to select a diagnostic factor that falls within the critical range (TH) among the plurality of diagnostic factors, and to diagnose the state of the battery corresponding to the selected diagnostic factor as normal.
[0254] Additionally, after the critical range (TH) of the diagnostic factor values of a normal battery is determined for each diagnostic factor, diagnosis of a new battery can be performed through a simplified process of determining whether the value of the diagnostic factor of the battery falls within the critical range.
[0255] The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.
[0256] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.
[0257] In addition, the present invention described above is not limited to the above-described embodiments and the attached drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications can be made, as those skilled in the art can make various substitutions, modifications, and changes within the scope of the technical idea of the present invention.
[0258] [Explanation of symbols]
[0259] 1: Battery pack
[0260] 10: Battery
[0261] 20: Measurement section
[0262] 100: Battery Diagnostic Device
[0263] 110: Profile acquisition section
[0264] 120: Profile correction section
[0265] 130: Control unit
[0266] 140: Storage
[0267] 1700: Automobile
[0268] 1710: Battery Pack
Claims
1. A profile acquisition unit configured to acquire a battery profile indicating a correspondence between the voltage and capacity of a diagnostic target battery charged or discharged at a predetermined target C-rate; A profile correction unit configured to generate a correction profile by correcting the battery profile based on an overvoltage profile indicating an overvoltage by capacity of the reference battery that occurs when the reference battery is charged or discharged at the target seal rate, and to generate an adjusted negative electrode profile that is adjusted to indicate a correspondence between the negative electrode capacity and the negative electrode potential of the battery to be diagnosed using the correction profile; and A battery diagnostic device characterized by including a control unit configured to extract a negative electrode loading value from the above-described adjusted negative electrode profile as a diagnostic factor for the battery to be diagnosed, and to diagnose the state of the battery to be diagnosed based on the extracted diagnostic factor.
2. In paragraph 1, The above overvoltage profile is, A battery diagnostic device characterized in that the profile represents a voltage difference by capacity between a first battery profile of the reference battery obtained when the reference battery is charged or discharged at a reference rate, and a second battery profile of the reference battery obtained when the reference battery is charged or discharged at the target rate.
3. In paragraph 2, The above profile correction part, A battery diagnostic device characterized in that it is configured to generate the correction profile by calculating the voltage difference by capacity between the battery profile and the overvoltage profile.
4. In paragraph 2, It further includes overvoltage profiles indicating overvoltage by capacity of the reference battery that occurs when the reference battery is charged or discharged at a rate different from the target rate, and a storage unit that stores the overvoltage profile. The above profile correction part, A battery diagnostic device characterized in that it is configured to select an overvoltage profile corresponding to the target rate among the overvoltage profiles stored in the storage unit, and to generate the correction profile using the selected overvoltage profile.
5. In paragraph 1, The above profile correction part, A battery diagnostic device characterized in that it is configured to generate a comparison full-cell profile corresponding to the correction profile by mutually synthesizing a predetermined reference positive electrode profile and a reference negative electrode profile, and to provide a reference negative electrode profile adjusted to generate the comparison full-cell profile as the adjusted negative electrode profile.
6. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to diagnose the battery to be diagnosed as being in an abnormal state when the negative loading value does not fall within a predetermined threshold range.
7. In paragraph 1, The above control unit, A battery diagnostic device characterized in that it is configured to further extract one or two or more of the negative electrode starting potential value, the negative electrode ending potential value, and the negative electrode change ratio from the above-mentioned adjusted negative electrode profile as diagnostic factors, and to diagnose the state of the battery to be diagnosed based on the extracted diagnostic factors.
8. In paragraph 7, The above control unit, A battery diagnostic device characterized in that it is configured to diagnose the battery to be diagnosed as being in a normal state when the values of a predetermined number or more of the above-mentioned extracted diagnostic factors fall within a corresponding critical range.
9. A battery pack comprising a battery diagnostic device according to any one of claims 1 to 8.
10. A battery manufacturing system including a battery diagnostic device according to any one of claims 1 to 8.
11. A vehicle including a battery diagnostic device according to any one of claims 1 to 8.
12. A profile acquisition step for acquiring a battery profile indicating a correspondence between the voltage and capacity of a diagnostic target battery charged or discharged at a predetermined target C-rate; A correction profile generation step for generating a correction profile by correcting the battery profile based on an overvoltage profile indicating an overvoltage by capacity of the reference battery that occurs when the reference battery is charged or discharged at the target rate; A profile adjustment step of generating an adjusted negative electrode profile adjusted to represent a correspondence between the negative electrode capacity and the negative electrode potential of the battery to be diagnosed using the above correction profile; A diagnostic factor extraction step for extracting a negative loading amount value from the above-mentioned adjusted negative profile as a diagnostic factor for the battery to be diagnosed; and A battery diagnosis method characterized by including a status diagnosis step of diagnosing the status of the battery to be diagnosed based on the negative loading value.
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