Charging depth setting device and method

Abstract

A charging depth setting device according to an embodiment of the present disclosure includes: a charging and discharging unit configured to charge a battery to a set target voltage and discharge the battery after charging; a profile acquisition unit configured to acquire a voltage profile of the battery's capacity and voltage while the battery is being charged and discharged, and to acquire a voltage differential profile of the battery's capacity and differential from the acquired voltage profile; and a processor electrically connected to the charging and discharging unit to sequentially select any one of a plurality of preset voltages and set the selected preset voltage as the target voltage, wherein when the profile acquisition unit acquires all of the plurality of differential profiles corresponding to the plurality of voltages, the processor is configured to acquire a feature value of a target peak value in each of the plurality of differential profiles and to set the charging depth of the battery based on the plurality of acquired feature values.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0058601, filed in Korea on May 15, 2020, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a charging depth setting device and method, and more particularly, to a DOC setting device and method capable of setting the depth of charge (DOC) of a battery. Background Technology

[0003] Recently, demand for portable electronic products (such as laptops, cameras, and mobile phones) has increased dramatically, and electric vehicles, energy storage batteries, robots, and satellites have seen significant development. Correspondingly, high-performance batteries that allow for repeated charging and discharging are being actively researched.

[0004] Currently available batteries include nickel-cadmium (NiCd), nickel-metal hydride (NiMH), nickel-zinc (NiZn), and lithium-ion batteries. Among them, lithium-ion batteries have attracted much attention because they have almost no memory effect compared to nickel-based batteries and also have a very low self-discharge rate and high energy density.

[0005] However, batteries suffer from reduced production yields due to reverse voltage faults during the manufacturing process. It has been pointed out that one cause of this reverse voltage is the presence of LiC6 and LiC in the battery's negative electrode. 12 The non-uniformity of the LiC6 and LiC6 electrodes (Non-Patent Document 1). Therefore, to prevent reverse voltage in the battery, it is necessary to address the non-uniformity of the LiC6 and LiC6 electrodes in the negative electrode. 12 Non-uniformity between them.

[0006] (Non-patent literature 1) J Wilhelm et al., In Situ Neutron Diffraction Study of Lithiation Gradients in Graphite Anodes during Discharge and Relaxation, Journal of The Electrochemical Society, 165(9)A1846-A1856 2018. Summary of the Invention

[0007] Technical issues

[0008] This disclosure is designed to solve problems in related technologies; therefore, this disclosure aims to provide a method for LiC-based... 12The device and method for setting the DOC (Depth of Charge) of a battery by using the most prominent target peak value of the behavior.

[0009] These and other objects and advantages of this disclosure will become apparent from the following detailed description and will become more fully apparent from the exemplary embodiments thereof. Moreover, it will be readily understood that the objects and advantages of this disclosure can be achieved by the means and combinations thereof shown in the appended claims.

[0010] Technical solution

[0011] In one aspect of this disclosure, a DOC (Depth of Charge) setting device is provided, comprising: a charging and discharging unit configured to charge a battery to a set target voltage and discharge the charged battery; a profile acquisition unit configured to acquire a voltage profile of the battery's capacity and voltage while the battery is being charged and discharged, and to acquire a differential profile of the battery's capacity and differential voltage from the acquired voltage profile; and a processor electrically connected to the charging and discharging unit to sequentially select any one of a plurality of preset voltages and set the selected preset voltage as the target voltage, wherein when the profile acquisition unit acquires all of the plurality of differential profiles corresponding to the plurality of voltages, the processor is configured to acquire a characteristic value of a target peak value in each of the plurality of differential profiles and set the DOC of the battery based on the acquired plurality of characteristic values.

[0012] The processor can be configured to compare the magnitudes of the acquired plurality of feature values, select any one of a plurality of target voltages corresponding to the acquired plurality of feature values ​​as a reference voltage based on the comparison result, and set the selected reference voltage as DOC.

[0013] The processor can be configured to calculate the magnitude difference between multiple characteristic values ​​that are close to each other in the corresponding target voltage, select multiple reference characteristic values ​​with the largest calculated magnitude difference, and select any one of the multiple target voltages as the reference voltage based on the magnitude difference of the selected multiple reference characteristic values.

[0014] The processor can be configured to calculate the size difference by comparing the magnitudes of two eigenvalues ​​that are close to each other based on the corresponding target voltage.

[0015] The processor can be configured to select the target voltage on the lowest potential side of the plurality of target voltages corresponding to the plurality of selected reference characteristic values ​​as the reference voltage.

[0016] The processor can be configured to select a target voltage on the low potential side as a reference voltage when the magnitude difference between the selected plurality of reference characteristic values ​​is greater than or equal to a predetermined magnitude value.

[0017] The processor can be configured to select the target voltage at the highest potential side among the plurality of target voltages as the reference voltage when the magnitude difference between the selected plurality of reference characteristic values ​​is less than a predetermined magnitude value.

[0018] The profile acquisition unit can be configured to acquire differential profiles of the battery's differential voltage and capacity, the differential voltage being obtained by differentiating the battery's voltage with respect to the capacity.

[0019] The processor can be configured to determine at least one peak pair in each of the plurality of differential profiles, select the peak pair in which the differential voltages of the plurality of peaks included in the determined peak pair are most different, and select the peak in the plurality of peaks included in the selected peak pair that is on the low-capacity side as the target peak.

[0020] The processor can be configured to identify two peaks located at the top and bottom of the region where the differential voltage increases with the increase of battery capacity as a peak pair.

[0021] In batteries that include graphite as the negative electrode active material, the target peak value can be based on the ratio of DOC to LiC. 12 The peak value associated with the behavior.

[0022] The processor can be configured to obtain multiple normal distribution profiles by normalizing each of the multiple differential profiles and to obtain the full width at half maximum (FWHM) of the target peak value corresponding to each of the multiple obtained normal distribution profiles as a feature value.

[0023] A battery manufacturing apparatus according to another aspect of this disclosure may include a DOC setting device according to aspects of this disclosure.

[0024] A DOC setting method according to another aspect of this disclosure may include: a target voltage setting step: sequentially selecting any one of a plurality of preset voltages and setting the selected preset voltage as the target voltage; a charging and discharging step: charging the battery to the target voltage and discharging the charged battery; a voltage profile acquisition step: acquiring a voltage profile of the battery's capacity and voltage while the battery is being charged and discharged; a differential profile acquisition step: acquiring a differential profile of the battery's capacity and differential voltage from the acquired voltage profile; a differential profile repetition acquisition step: acquiring all of the plurality of differential profiles corresponding to the plurality of voltages; a feature value acquisition step: acquiring a feature value of the target peak value in each of the plurality of differential profiles; and a DOC setting step: setting the DOC of the battery based on the plurality of acquired feature values.

[0025] Beneficial effects

[0026] According to one aspect of this disclosure, it is possible to effectively prevent the generation of reverse voltage in the battery.

[0027] In addition, according to one aspect of this disclosure, it has the advantage of being able to set a DOC that maximizes battery performance while suppressing the generation of reverse voltage in the battery.

[0028] The effects of this disclosure are not limited to those described above, and other effects not mentioned herein will be clearly understood by those skilled in the art from the appended claims. Attached Figure Description

[0029] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings.

[0030] Figure 1 This is a schematic diagram illustrating a DOC setting device according to an embodiment of the present disclosure.

[0031] Figure 2 This is a diagram schematically illustrating an exemplary configuration of a battery manufacturing apparatus including a DOC setting device according to embodiments of the present disclosure.

[0032] Figure 3 This is a diagram schematically illustrating an embodiment of a differential profile obtained by a DOC setting device according to an embodiment of the present disclosure.

[0033] Figure 4 This is a diagram schematically illustrating an embodiment of multiple differential profiles obtained by a DOC setting device according to an embodiment of the present disclosure.

[0034] Figure 5This is a diagram schematically illustrating an embodiment of feature points of multiple target peaks acquired by a DOC setting device according to an embodiment of the present disclosure.

[0035] Figure 6 This is a diagram schematically illustrating a DOC setting method according to another embodiment of the present disclosure. Detailed Implementation

[0036] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but rather interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of the principle that the inventors are allowed to properly define the terms for the best interpretation.

[0037] Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of this disclosure. It should be understood that other equivalents and modifications may be made thereto without departing from the scope of this disclosure.

[0038] Additionally, in describing this disclosure, detailed descriptions of known elements or functions are omitted here if they are considered to obscure the key subject matter of the disclosure.

[0039] Ordinal terms such as “first” and “second” can be used to distinguish one element from another among various elements, but are not intended to limit the elements by means of such terms.

[0040] Throughout this specification, when a section is referred to as “comprising” or “including” any element, it means that the section may further include other elements without excluding them, unless otherwise specifically stated.

[0041] Furthermore, the term "processor" as described in the specification refers to a unit that processes at least one function or operation, and can be implemented by hardware, software, or a combination of hardware and software.

[0042] Furthermore, throughout the specification, when a part is referred to as being "connected" to another part, this is not limited to the case where they are "directly connected," but also includes the case where they are "indirectly connected" with another element in between.

[0043] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0044] Figure 1 This is a schematic diagram illustrating a DOC setting device 100 according to an embodiment of the present disclosure. Figure 2 This is a diagram schematically illustrating an exemplary configuration of a battery manufacturing apparatus 1 including a DOC setting device 100 according to an embodiment of the present disclosure.

[0045] Specifically, the battery manufacturing apparatus 1 can be used in the process of manufacturing battery B. Preferably, in various processes of manufacturing battery B, the battery manufacturing apparatus 1 can be used during the activation process.

[0046] refer to Figure 1 The DOC setting device 100 may include a charging and discharging unit 110, a profile acquisition unit 120, and a processor 130.

[0047] Here, battery B can refer to a single, physically separable battery cell that includes a negative electrode terminal and a positive electrode terminal. For example, a pouch-type lithium polymer cell can be considered battery B.

[0048] The charging and discharging unit 110 can be configured to charge the battery B to a set target voltage.

[0049] Here, the target voltage for charging battery B can be set by processor 130. Additionally, charging and discharging unit 110 can obtain information about the target voltage from processor 130 and charge battery B to the target voltage.

[0050] For example, in Figure 2 In this embodiment, the charging and discharging unit 110 can be electrically connected to the battery B. Additionally, the charging and discharging unit 110 can charge the battery B until its voltage reaches a target voltage.

[0051] Additionally, the charging and discharging unit 110 can be configured to discharge the battery B after it has been fully charged.

[0052] Here, charging completion means that the voltage of battery B has reached the target voltage. That is, the charging and discharging unit 110 can charge battery B to the target voltage and then discharge battery B again. For example, before the manufactured battery B is shipped, an activation process can be performed on battery B while it is being charged and discharged by the charging and discharging unit 110.

[0053] Preferably, the charging and discharging unit 110 can discharge the battery B at a low rate. For example, the charging and discharging unit 110 can discharge the battery B at a C rate of 0.33C or lower. More preferably, the charging and discharging unit 110 can discharge the battery B at a C rate of 0.05C. Specifically, during the discharge of the battery B by the charging and discharging unit 110, the profile acquisition unit 120 can acquire a differential profile 20, and the differential profile 20 can include multiple peaks indicating the voltage behavior of the battery B. Because the peaks are displayed more accurately without distortion or omission when discharging at a low rate, the charging and discharging unit 110 can discharge the battery B at a low rate.

[0054] The profile acquisition unit 120 can be configured to acquire a voltage profile of the capacity and voltage of the battery B while the battery B is being charged or discharged.

[0055] Specifically, the profile acquisition unit 120 can measure the voltage at both ends of battery B and the current of battery B. For example, in Figure 2 In this embodiment, the profile acquisition unit 120 can measure the voltage of battery B via the first sensing line SL1 and the second sensing line SL2. Additionally, the profile acquisition unit 120 can be connected to a current measurement unit A, which is positioned on a high-current path of battery B, via a third sensing line SL3. Therefore, the profile acquisition unit 120 can measure the current of battery B via the third sensing line SL3.

[0056] For example, a voltage profile can be a profile indicating the voltage of battery B relative to the capacity of battery B. More specifically, the voltage profile can be represented as a two-dimensional graph, in which the X-axis represents the capacity of battery B and the Y-axis represents the voltage of battery B.

[0057] The profile acquisition unit 120 can acquire the voltage profile while the battery B is being charged and / or discharged. However, for ease of explanation, it is assumed in the following text that the voltage profile is acquired while the battery B is being discharged.

[0058] The profile acquisition unit 120 can be configured to acquire a differential profile 20 relating to the capacity and differential voltage of battery B from the acquired voltage profile. Specifically, the profile acquisition unit 120 can be configured to acquire a differential profile 20 relating to the differential voltage and capacity of battery B, wherein the differential voltage is acquired by differentiating the voltage of battery B with respect to capacity.

[0059] For example, the differential profile 20 can be a profile indicating the differential voltage of battery B relative to its capacity. Here, the differential voltage can be a value (dV / dQ) obtained by differentiating the voltage of battery B with respect to its capacity. More specifically, the differential profile 20 can be expressed as a two-dimensional graph where the X-axis represents the capacity of battery B and the Y-axis represents the differential voltage of battery B.

[0060] Figure 3 This is a diagram schematically illustrating an embodiment of a differential profile 20 acquired by a DOC setting device 100 according to an embodiment of the present disclosure.

[0061] Specifically, Figure 3 The differential profile 20 is shown as the battery B, charged to 4.3V, is discharged to 2.0V, while being obtained by the profile acquisition unit 120. The target voltage of the battery B corresponding to the differential profile 20 is 4.3V.

[0062] exist Figure 3 In this embodiment, the differential profile 20 includes multiple peaks, and to clearly illustrate the multiple peaks, the battery B is discharged at a C rate of 0.05C. Here, a peak is a point corresponding to an inflection point in the voltage profile, and can mean a point in the differential profile 20 where the instantaneous slope is 0. For example, Figure 3 The differential profile 20 of the embodiment may include a first peak P1, a second peak P2, a third peak P3, a fourth peak P4, a fifth peak P5, a sixth peak P6, and a seventh peak P7.

[0063] The processor 130 can be electrically connected to the charging and discharging unit 110 and can be configured to sequentially select any one of a plurality of preset voltages and set the selected preset voltage as the target voltage.

[0064] Specifically, multiple preset voltages can be set according to the maximum available voltage of battery B. For example, for battery B, the multiple preset voltages can be a first target voltage of 4.0 [V], a second target voltage of 4.1 [V], a third target voltage of 4.2 [V], and a fourth target voltage of 4.3 [V]. In the following description, multiple voltages will be set to four voltages according to voltage intervals of 0.1 [V]. However, it should be understood that in order to more accurately set the DOC (depth of charge) of battery B, the voltage intervals between the multiple voltages become narrower, and the number of multiple preset voltages can be increased.

[0065] For example, in Figure 3 In this embodiment, the processor 130 can set a target voltage of 4.3V and transmit the set target voltage (4.3V) to the charging and discharging unit 110. After this, the charging and discharging unit 110 can charge the battery B until its voltage reaches 4.3V, and then discharge the battery B until its voltage reaches 2.0V. During the discharge of the battery B, the profile acquisition unit 120 can measure the voltage and current of the battery B and acquire a differential profile 20 based on the measured voltage and current.

[0066] Furthermore, if the profile acquisition unit 120 acquires all the multiple differential profiles corresponding to multiple voltages, the processor 130 can be configured to acquire the characteristic value of the target peak in each of the multiple differential profiles.

[0067] exist Figure 2In this embodiment, the processor 130 can be electrically connected to the profile acquisition unit 120. That is, the processor 130 can determine whether the profile acquisition unit 120 has acquired a differential profile 20 corresponding to any target voltage. In addition, when the profile acquisition unit 120 acquires a differential profile 20 corresponding to any target voltage, the processor 130 can set a voltage that does not overlap with the corresponding target voltage from a plurality of preset voltages as the target voltage.

[0068] Figure 4 This is a diagram schematically illustrating an embodiment of multiple differential profiles 21, 22, 23, 24 acquired by a DOC setting device 100 according to an embodiment of the present disclosure.

[0069] exist Figure 4 In one embodiment, it is assumed that multiple voltages are preset as a first target voltage of 4.0 [V], a second target voltage of 4.1 [V], a third target voltage of 4.2 [V], and a fourth target voltage of 4.3 [V].

[0070] First, the processor 130 can set 4.0 [V] as a first target voltage among multiple voltages and transmit the set first target voltage to the charging and discharging unit 110. Additionally, the profile acquisition unit 120 can acquire the first differential profile 21 while the battery B, charged to the first target voltage, is being discharged.

[0071] Next, the processor 130 can set 4.1 [V] as the second target voltage among multiple voltages, and transmit the set second target voltage to the charging and discharging unit 110. In addition, the profile acquisition unit 120 can acquire the second differential profile 22 while the battery B, which is charged to the second target voltage, is being discharged.

[0072] Next, the processor 130 can set 4.2 [V] as the third target voltage among multiple voltages, and transmit the set third target voltage to the charging and discharging unit 110. In addition, the profile acquisition unit 120 can acquire the third differential profile 23 while the battery B, which is charged to the third target voltage, is being discharged.

[0073] Finally, the processor 130 can set 4.3 [V] as the fourth target voltage among multiple voltages and transmit the set fourth target voltage to the charging and discharging unit 110. In addition, the profile acquisition unit 120 can acquire the fourth differential profile 24 while the battery B, which is charged to the fourth target voltage, is being discharged.

[0074] After that, the processor 130 can select target peaks Tp1, Tp2, Tp3, and Tp4 in each of the first differential profiles 21 to the fourth differential profiles 24, and calculate the eigenvalues ​​of the selected target peaks.

[0075] Here, the target peak value can be any one of the multiple peak values ​​included in the differential profile. Specifically, in battery B, which includes graphite as the negative electrode active material, the target peak value can be based on the ratio of DOC to LiC. 12 The peak value associated with the behavior.

[0076] For example, in Figure 3 In this embodiment, among the multiple peaks P1 to P7, the fourth peak P4 can be selected as the target peak. The process by which the processor 130 selects the target peak will be described in detail later.

[0077] Moreover, in Figure 4 In this embodiment, the processor 130 can select a first target peak Tp1 in the first differential profile 21 and can select a second target peak Tp2 in the second differential profile 22. Additionally, the processor 130 can select a third target peak Tp3 in the third differential profile 23 and can select a fourth target peak Tp4 in the fourth differential profile 24.

[0078] Furthermore, the characteristic value of the target peak can be a value selected to obtain the difference between the target peaks Tp1, Tp2, Tp3, and Tp4 selected in each of the multiple differential profiles 21, 22, 23, and 24. For example, the characteristic value of the target peak can include a capacitance value, a differential voltage value, or the half-maximum full width (FWHM) of the target peak. Preferably, the characteristic value of the target peak can be FWHM. Here, FWHM can also be translated into various terms.

[0079] Figure 5 This is a diagram schematically illustrating an embodiment of feature points of multiple target peaks Tp1, Tp2, Tp3, Tp4 acquired by a DOC setting device 100 according to an embodiment of the present disclosure.

[0080] refer to Figure 5 The processor 130 can calculate the feature value of each of the first target peak Tp1, the second target peak Tp2, the third target peak Tp3, and the fourth target peak Tp4. Specifically, in Figure 5 In the embodiments, the calculated feature value can be the FWHM of the target peak.

[0081] Additionally, the processor 130 can be configured to set the DOC for battery B based on multiple acquired feature values.

[0082] Here, DOC is a value set during the activation process of battery B, and can mean the maximum permissible charging voltage for battery B, which is set to prevent reverse voltage from being generated in battery B.

[0083] For example, even if batteries B are manufactured in the same production line, reverse voltage may still occur in some batteries B due to various reasons. Because batteries B that generate reverse voltage have a problem of voltage increasing over time, unlike batteries B that do not experience reverse voltage, it is important to set the DOC (Diesel Occurrence Cost) low during the processing stage (especially the activation process). Furthermore, since it is necessary to experimentally check whether reverse voltage occurs in battery B, the processor 130 can determine whether reverse voltage is likely to occur in battery B based on the characteristic values ​​of multiple target peaks of battery B, and appropriately set the DOC of battery B according to the determination result.

[0084] For example, in Figure 5 In one embodiment, the processor 130 can compare the feature values ​​of the first target peak Tp1, the second target peak Tp2, the third target peak Tp3, and the fourth target peak Tp4, and based on the comparison results, set 4.2 [V], which is the target voltage corresponding to the third differential profile 23, as the DOC for the battery B.

[0085] Therefore, the DOC setting device 100 according to an embodiment of this disclosure can prevent the generation of reverse voltage in battery B in advance by setting the DOC corresponding to battery B during the activation process. Thus, because the degradation rate of battery B is slowed down, battery B can be used for a longer period of time, ensuring economic efficiency and eco-friendliness. Furthermore, because an appropriate DOC is set for each battery B, accidents that may occur due to reverse voltage in battery B can be prevented in advance.

[0086] Meanwhile, the processor 130 included in the DOC setting device 100 according to embodiments of this disclosure may optionally include processors 130 known in the art, application-specific integrated circuits (ASICs), another chipset, logic circuits, registers, communication modems, and data processing devices, etc., to execute the various control logics disclosed below. Additionally, when the control logic is implemented in software, the processor 130 may be implemented as a set of program modules. In this case, the program modules may be stored in memory and executed by the processor 130. The memory may be located inside or outside the processor 130 and may be connected to the processor 130 by various well-known means.

[0087] Furthermore, the DOC setting device 100 may further include a storage unit 140. The storage unit 140 may store programs, data, etc., required by the processor 130 to set the DOC of the battery B. That is, the storage unit 140 may store data required for the operation and function of each component of the DOC setting device 100, data generated during the execution of operations or functions, etc. The storage unit 140 is not particularly limited in its type, as long as it is a known information storage device capable of recording, erasing, updating, and retrieving data. As examples, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. Additionally, the storage unit 140 may store program code defining processes that can be executed by the processor 130.

[0088] For example, multiple voltage profiles and multiple differential profiles 21, 22, 23, and 24 acquired by the profile acquisition unit 120 can be stored in the storage unit 140. Alternatively, the processor 130 can directly acquire the differential profiles 21, 22, 23, and 24 from the profile acquisition unit 120, or acquire the stored differential profiles 21, 22, 23, and 24 by accessing the storage unit 140.

[0089] Furthermore, the DOC of battery B set by processor 130 can be stored in storage unit 140. For example, the DOC set by processor 130 can be stored in storage unit 140 for each battery B. After that, the DOC of battery B stored in storage unit 140 can be stored in battery management system (BMS) configured to manage battery B, or stored in storage unit connected to battery management system.

[0090] That is, the DOC setting device 100 according to the embodiments of this disclosure can set a DOC corresponding to a single battery B and provide the set DOC to a battery management system configured to manage the single battery B. Accordingly, when the battery B is shipped and used, reverse voltage can be prevented from being generated in the battery B according to the DOC set by the DOC setting device 100. In addition, the battery B can degrade slowly, thereby increasing the lifespan of the battery B.

[0091] The process by which the processor 130 selects the target peak will be described in more detail below.

[0092] The processor 130 can be configured to compare the magnitudes of multiple acquired feature values.

[0093] Specifically, processor 130 can calculate the magnitude difference between multiple characteristic values ​​whose corresponding target voltages are close to each other. More specifically, processor 130 can calculate the magnitude difference by comparing the magnitudes of two characteristic values ​​whose corresponding target voltages are close to each other.

[0094] For example, in Figure 5 In this embodiment, the characteristic values ​​of the corresponding target voltages that are close to each other are the characteristic values ​​of the first target peak value Tp1 and the second target peak value Tp2, the characteristic values ​​of the second target peak value Tp2 and the third target peak value Tp3, and the characteristic values ​​of the third target peak value Tp3 and the fourth target peak value Tp4. The processor 130 can calculate a first magnitude difference D1 between the characteristic values ​​of the first target peak value Tp1 and the second target peak value Tp2. Additionally, the processor 130 can calculate a second magnitude difference D2 between the characteristic values ​​of the second target peak value Tp2 and the third target peak value Tp3. Furthermore, the processor 130 can calculate a third magnitude difference D3 between the characteristic values ​​of the third target peak value Tp3 and the fourth target peak value Tp4.

[0095] The processor 130 can be configured to select, based on the comparison result, any one of a plurality of target voltages corresponding to each of the plurality of acquired feature values ​​as a reference voltage. Additionally, the processor 130 can be configured to set the selected reference voltage as DOC.

[0096] In one embodiment, the processor 130 may be configured to select a plurality of reference feature values ​​with the largest calculated magnitude difference. Alternatively, the processor 130 may be configured to select any one of a plurality of target voltages as a reference voltage based on the magnitude difference between the plurality of selected reference feature values.

[0097] For example, in Figure 5 In this embodiment, the processor 130 can compare a first size difference D1, a second size difference D2, and a third size difference D3. Because the third size difference D3 is greater than the first size difference D1 and the second size difference D2, the processor 130 can select the characteristic values ​​of the third target peak Tp3 and the fourth target peak Tp4 as reference characteristic values. Additionally, the processor 130 can select either the third target voltage corresponding to the third target peak Tp3 or the fourth target voltage corresponding to the fourth target peak Tp4 as the reference voltage.

[0098] Specifically, the processor 130 can be configured to select the target voltage at the lowest potential side among a plurality of target voltages corresponding to a plurality of selected reference characteristic values ​​as the reference voltage.

[0099] For example, in Figure 5In this embodiment, the processor 130 can select the third target voltage, which is on the lower potential side of the third target voltage and the fourth target voltage, as the reference voltage. That is, the processor 130 can select the two reference characteristic values ​​with the largest difference in magnitude, and set the lower target voltage of the two target voltages corresponding to the two selected reference characteristic values ​​as the DOC of battery B.

[0100] That is, because the DOC of battery B is set low, the generation of reverse voltage in battery B can be suppressed. Furthermore, because the DOC of battery B is set based on two reference characteristic values ​​having the largest difference between the characteristic values ​​of multiple target peaks, it is possible to prevent the DOC of battery B from being set too low. Therefore, the DOC setting device 100 according to the embodiment of this disclosure has the advantage of setting the DOC such that the performance of battery B can be maximized while suppressing the occurrence of reverse voltage in battery B.

[0101] In another embodiment, the processor 130 may be configured to select a target voltage on the low potential side as a reference voltage when the magnitude difference between a plurality of selected reference feature values ​​is equal to or greater than a predetermined magnitude value.

[0102] For example, a predetermined size value can be set to a predetermined value. Figure 5 In some embodiments, the predetermined size value can be set to any size value that is 0.5 or greater and less than 1.

[0103] As another example, the predetermined size value can be set to be twice the size of the second largest size difference among multiple size differences. Figure 5 In this embodiment, the multiple size differences are a first size difference D1, a second size difference D2, and a third size difference D3. Furthermore, among the multiple size differences, the third size difference D3 is the largest, and the first size difference D1 is the second largest. Accordingly, the predetermined size value can be set to a value that is twice the size of the first size difference D1.

[0104] When the magnitude difference between multiple reference feature values ​​is significantly different from the magnitude difference between the remaining feature values, the processor 130 can set a predetermined magnitude value in a manner that appropriately sets the DOC of the battery B.

[0105] Unlike the embodiments described above, the processor 130 can set the target voltage on the low potential side among the multiple target voltages corresponding to the multiple reference characteristic values ​​as the DOC of battery B only when the magnitude difference between the multiple reference characteristic values ​​is equal to or greater than a predetermined magnitude value. Conversely, when the magnitude difference between the multiple selected reference characteristic values ​​is less than a predetermined magnitude value, the processor 130 can be configured to select the target voltage on the highest potential side among the multiple target voltages as the reference voltage.

[0106] For example, in Figure 5 In this embodiment, because the third size difference D3 is greater than the first size difference D1 and the second size difference D2, the characteristic values ​​of the third target peak Tp3 and the fourth target peak Tp4 can be selected as multiple reference characteristic values. Furthermore, the processor 130 can compare the third size difference D3 with a predetermined size value. If the third size difference D3 is greater than or equal to the predetermined size value, the processor 130 can set the third target voltage, which is the target voltage on the low potential side among the third target voltage and the fourth target voltage corresponding to the multiple reference characteristic values, as the DOC of battery B.

[0107] That is, if the magnitude difference between the multiple reference characteristic values ​​is equal to or greater than a predetermined magnitude value, then when the DOC of battery B is set to a target voltage on the high potential side among the multiple target voltages corresponding to the multiple reference characteristic values, processor 130 can determine that a reverse voltage has occurred in battery B. Accordingly, in order to prevent the generation of a reverse voltage in battery B, processor 130 can set the DOC of battery B to a target voltage on the low potential side among the multiple target voltages corresponding to the multiple reference characteristic values.

[0108] On the contrary, Figure 5 In one embodiment, if the third size difference D3 is less than a predetermined size value, the processor 130 can set the fourth target voltage, which is the target voltage at the highest potential side among the first target voltage, second target voltage, third target voltage and fourth target voltage, as the DOC of battery B.

[0109] That is, if the magnitude difference between the characteristic values ​​of multiple target peaks is all less than a predetermined value, the processor 130 can determine that no reverse voltage is generated in the battery B. Accordingly, in order to maximize the performance of the battery B, the processor 130 can set the DOC of the battery B to the target voltage on the highest potential side among multiple target voltages.

[0110] Therefore, by setting the DOC of battery B based on the result of comparing the magnitude difference between a predetermined magnitude value and a reference characteristic value, the DOC setting device 100 according to the embodiments of the present disclosure has the advantage of maximizing the performance of battery B and harmoniously suppressing the reverse voltage of battery B.

[0111] The process by which the processor 130 selects the target peak value in each of the multiple differential profiles 21, 22, 23, and 24 will be described in detail below.

[0112] The processor 130 can be configured to determine at least one pair of peaks in each of the plurality of differential profiles 21, 22, 23, 24. For example, in Figure 3In one embodiment, the processor 130 may select a first peak P1, a second peak P2, a third peak P3, a fourth peak P4, a fifth peak P5, a sixth peak P6, and a seventh peak P7.

[0113] Specifically, the processor 130 can be configured to identify two of the multiple peaks as a peak pair, the two peaks being located at the top and bottom of the region where the differential voltage increases with the increase of the capacity of the battery B.

[0114] For example, in Figure 3 In this embodiment, the second peak P2 and the third peak P3 can be included in the region where the differential voltage increases with the increase of capacitance. Furthermore, because the second peak P2 and the third peak P3 are located at the bottom and top of the region where the differential voltage increases, respectively, the second peak P2 and the third peak P3 can be identified as a peak pair.

[0115] Furthermore, the fourth peak P4 and the fifth peak P5 can also be included in the region where the differential voltage increases with the increase of capacitance. Additionally, since the fourth peak P4 and the fifth peak P5 are located at the bottom and top of the region where the differential voltage increases, respectively, they can be identified as a peak pair.

[0116] Additionally, the sixth peak P6 and the seventh peak P7 can also be included in the region where the differential voltage increases with increasing capacitance. Furthermore, since the sixth peak P6 and the seventh peak P7 are located at the bottom and top of the region where the differential voltage increases, respectively, the sixth peak P6 and the seventh peak P7 can be identified as a peak pair.

[0117] That is, the processor 130 can determine a first peak pair including a second peak P2 and a third peak P3, a second peak pair including a fourth peak P4 and a fifth peak P5, and a third peak pair including a sixth peak P6 and a seventh peak P7.

[0118] The processor 130 can be configured to select the peak pair from the determined peak pairs whose differential voltages are most different.

[0119] For example, in Figure 3In one embodiment, the processor 130 can calculate the difference between the differential voltages of the second peak P2 and the third peak P3 included in the first peak pair. Furthermore, the processor 130 can calculate the difference between the differential voltages of the fourth peak P4 and the fifth peak P5 included in the second peak pair. Moreover, the processor 130 can calculate the difference between the differential voltages of the sixth peak P6 and the seventh peak P7 included in the third peak pair. Additionally, the processor 130 can select the second peak pair from the first, second, and third peak pairs as the peak pair with the most distinct differential voltages among the included peaks.

[0120] Additionally, the processor 130 can be configured to select the peak on the low-capacity side of a plurality of peaks included in the selected peak pair as the target peak.

[0121] For example, in Figure 3 In one embodiment, the processor 130 can select the fourth peak P4 from the fourth peak P4 and the fifth peak P5 included in the second peak pair as the target peak. Specifically, in battery B, which includes graphite as the negative electrode active material, the peak can be determined based on the ratio of DOC to LiC. 12 The peak value associated with the behavior.

[0122] Referring back to non-patent literature 1, one possible reason for the reverse voltage of battery B is the difference between LiC6 and LiC. 12 Non-uniformity between them.

[0123] To prevent this non-uniformity, the processor 130 can select the LiC shown in each differential profile 20 in the manner described above. 12 The optimal behavior of the target peak is determined, and the characteristic values ​​of multiple target peaks are compared to set the DOC of battery B. That is, in battery B, where the DOC is set by processor 130, LiC6 and LiC 12 It can be maintained evenly.

[0124] Specifically, in LiC6 and LiC 12 The phase transition between them may occur abruptly within a predetermined voltage range, and if in LiC6 and LiC 12 This non-uniformity can lead to a reverse voltage in battery B. For example, in... Figure 5 In one embodiment, the predetermined voltage range may be between 4.2 [V] and 4.3 [V].

[0125] Therefore, the DOC setting device 100 according to an embodiment of the present disclosure can prevent LiC6 and LiC by comparing the characteristic values ​​of multiple target peaks of battery B and setting an appropriate DOC for battery B. 12The rapid phase transition occurs. Therefore, it effectively prevents the generation of reverse voltage in battery B.

[0126] The processor 130 can be configured to obtain multiple normally distributed profiles by normalizing each of the multiple differential profiles 21, 22, 23, 24.

[0127] For example, in Figure 4 In this embodiment, each differential profile 20 may not follow a normal distribution. Accordingly, the processor 130 can normalize each of the multiple differential profiles 21, 22, 23, 24 to calculate the target peak value (FWHM) of each of the multiple differential profiles 21, 22, 23, 24. Through this process, the processor 130 can obtain multiple normally distributed profiles based on the multiple differential profiles 21, 22, 23, 24.

[0128] Additionally, the processor 130 can be configured to acquire the target peak value FWHM corresponding to each of the multiple acquired normal distribution profiles as a feature value.

[0129] Here, FWHM can be defined as the difference between the values ​​of two independent variables that are half the maximum value of the function. That is, suppose the function F(X) has a maximum value F(Xmax) at Xmax and the values ​​of the function F(X) at X1 and X2 decrease to half the maximum value F(Xmax). That is, F(X1) and F(X2) can be equivalently expressed as "F(Xmax) ÷ 2". In this case, FWHM is the absolute value of the difference between X1 and X2.

[0130] Generally, calculating the difference between multiple FWHMs to calculate the difference between multiple peaks is considered a more stable method than directly comparing the magnitudes of multiple peaks.

[0131] For example, in Figure 4 In the embodiments, the differential voltages of the first target peak value Tp1, the second target peak value Tp2, the third target peak value Tp3, and the fourth target peak value Tp4 appear to increase gradually. Similarly, in Figure 5 In the embodiments, the feature values ​​of the first target peak Tp1, the second target peak Tp2, the third target peak Tp3, and the fourth target peak Tp4 also appear to gradually increase.

[0132] However, in Figure 4 In the embodiment, the differential voltages from the first target peak Tp1 to the fourth target peak Tp4 appear to increase linearly, therefore it can be determined that the differential difference between the third target peak Tp3 and the fourth target peak Tp4 is not significantly different from the differential differences between the remaining target peaks. Meanwhile, in Figure 5In one embodiment, the third size difference D3 appears to show a significant difference from the first size difference D1 and the second size difference D2.

[0133] That is, in order to more accurately compare multiple target peaks, the processor 130 can normalize multiple differential profiles 21, 22, 23, 24 and calculate the FWHM of each of the multiple target peaks as a characteristic value of each of the multiple target peaks. Therefore, the DOC setting device 100 according to the embodiments of the present disclosure has the advantage of setting an optimal DOC to prevent reverse voltage of battery B.

[0134] Furthermore, the DOC setting device 100 according to this disclosure can be installed in the battery manufacturing apparatus 1. That is, the battery manufacturing apparatus 1 according to this disclosure may include the aforementioned DOC setting device 100 and at least one battery B. In addition, the battery manufacturing apparatus 1 may further include electronic components (relays, fuses, etc.) and a housing.

[0135] For example, in Figure 2 In one embodiment, the DOC setting device 100 may be set to the battery manufacturing apparatus 1 and electrically connected to the battery B.

[0136] Preferably, the battery manufacturing apparatus 1 can be constructed during the activation process of the battery B. That is, the DOC setting device 100 according to the embodiment of the present disclosure can be electrically connected to the battery B during the activation process of the battery B to construct the battery manufacturing apparatus 1. In addition, during the activation process, the DOC setting device 100 can set the optimal DOC of the battery B.

[0137] Figure 6 This is a diagram schematically illustrating a DOC setting method according to another embodiment of the present disclosure.

[0138] Each step of the DOC setting method can be performed by the DOC setting device 100 according to an embodiment of the present disclosure. In the following, content repeated from the foregoing will be briefly described.

[0139] refer to Figure 6 The DOC setting method may include a target voltage setting step (S100), a charging and discharging step (S200), a voltage profile acquisition step (S300), a differential profile acquisition step (S400), a differential profile repeated acquisition step (S500), an eigenvalue acquisition step (S600), and a DOC setting step (S700).

[0140] The target voltage setting step (S100) is a step of sequentially selecting any one of a plurality of preset voltages and setting the selected preset voltage as the target voltage, and can be executed by the processor 130.

[0141] For example, multiple voltages can be preset to 4.0 [V], 4.1 [V], 4.2 [V], and 4.3 [V]. The processor 130 can first set 4.0 [V] as the first target voltage.

[0142] The charging and discharging step (S200) is the step of charging the battery B to the target voltage and discharging the battery B after it has been charged, and can be performed by the charging and discharging unit 110.

[0143] For example, the charging and discharging unit 110 can charge the battery B to a first target voltage (4.0 [V]) set by the processor 130. Additionally, the charging and discharging unit 110 can discharge the battery B at a low rate of 0.05C until the voltage of the battery B reaches 2.0 [V].

[0144] The voltage profile acquisition step (S300) is a step of acquiring a voltage profile of the capacity and voltage of the battery B while the battery B is being charged and discharged, and can be performed by the profile acquisition unit 120.

[0145] The profile acquisition unit 120 can measure the voltage and current of battery B while battery B is being discharged. Additionally, the profile acquisition unit 120 can acquire voltage profiles relating to the capacity and voltage of battery B.

[0146] The differential profile acquisition step (S400) is a step of acquiring a differential profile 20 about the capacity and differential voltage of battery B from the acquired voltage profile, and can be executed by the profile acquisition unit 120.

[0147] The profile acquisition unit 120 can differentiate the voltage of battery B with the capacity of battery B from the voltage profile acquired in the voltage profile acquisition step (S300). That is, the profile acquisition unit 120 can acquire a differential profile 20 with respect to the capacity of battery B and the differential voltage of battery B (the value obtained by differentiating the voltage of battery B with the capacity of battery B).

[0148] The differential profile repetition acquisition step (S500) is a step of acquiring all the multiple differential profiles 21, 22, 23, and 24 corresponding to multiple voltages, which can be executed by the processor 130, the charging and discharging unit 110, and the profile acquisition unit 120.

[0149] That is, the differential profile acquisition step (S500) can be a step of repeatedly executing the target voltage setting step (S100), the charging and discharging step (S200), the voltage profile acquisition step (S300), and the differential profile acquisition step (S400) until all differential profiles 20 have been acquired for multiple preset voltages.

[0150] Specifically, when all the differential profiles 21, 22, 23, and 24 corresponding to multiple voltages are acquired in the differential profile acquisition step (S500), the feature value acquisition step (S600) can be executed. Alternatively, when any one of the differential profiles 21, 22, 23, and 24 corresponding to multiple voltages is not acquired, the target voltage setting step (S100) can be executed.

[0151] For example, when the profile acquisition unit 120 acquires only the first differential profile 21 of the first target voltage, the processor 130 can set 4.1 [V] as the second target voltage. Additionally, the charging and discharging unit 110 can charge the battery B until its voltage reaches the second target voltage. After this, the charging and discharging unit 110 can discharge the battery B at a low rate of 0.05C until its voltage reaches 2.0 [V]. The profile acquisition unit 120 can acquire the second differential profile 22 corresponding to the second target voltage while the battery B is being discharged. Similarly, the profile acquisition unit 120 can acquire the third differential profile 23 corresponding to the third target voltage (4.2 [V]) and the fourth differential profile 24 corresponding to the fourth target voltage (4.3 [V]).

[0152] The eigenvalue acquisition step (S600) is a step of acquiring the eigenvalue of the target peak in each of the multiple differential profiles 21, 22, 23, 24, and can be executed by the processor 130.

[0153] The processor 130 can select a target peak value from each of the multiple differential profiles 21, 22, 23, and 24. Specifically, the target peak value can be determined based on the DOC and LiC. 12 The peak value associated with the behavior.

[0154] Furthermore, the processor 130 can calculate the FWHM as a feature value for each of the multiple target peaks. For this purpose, the processor 130 can obtain multiple normally distributed profiles by normalizing each of the multiple differential profiles 21, 22, 23, 24, and can separately calculate the FWHM of the target peak in each of the multiple obtained normally distributed profiles.

[0155] The DOC setting step (S700) is a step of setting the DOC of battery B based on multiple acquired feature values, and can be executed by processor 130.

[0156] For example, in Figure 5In this embodiment, the processor 130 can calculate a first magnitude difference D1 between the characteristic values ​​of the first target peak Tp1 and the second target peak Tp2. Additionally, the processor 130 can calculate a second magnitude difference D2 between the characteristic values ​​of the second target peak Tp2 and the third target peak Tp3. Furthermore, the processor 130 can calculate a third magnitude difference D3 between the characteristic values ​​of the third target peak Tp3 and the fourth target peak Tp4. Furthermore, the processor 130 can select the characteristic values ​​of the third target peak Tp3 and the fourth target peak Tp4 as reference characteristic values ​​based on the first magnitude difference D1, the second magnitude difference D2, and the third magnitude difference D3. Additionally, the processor 130 can select one of a third target voltage corresponding to the third target peak Tp3 and a fourth target voltage corresponding to the fourth target peak Tp4 as a reference voltage.

[0157] The embodiments of this disclosure described above are not necessarily to be implemented by devices and methods, but can also be implemented by a program for implementing functions corresponding to the configuration of this disclosure or a recording medium for recording the program. Based on the above description of the embodiments, such implementation can be readily performed by those skilled in the art.

[0158] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific examples indicate preferred embodiments of this disclosure, they are given by way of illustration only, as various changes and modifications within the scope of this disclosure will become apparent to those skilled in the art based on this detailed description.

[0159] Furthermore, without departing from the technical aspects of this disclosure, those skilled in the art can make many substitutions, modifications and changes to the disclosure described above, and this disclosure is not limited to the above embodiments and drawings, and each embodiment can be selectively combined in part or in whole to allow for various modifications.

[0160] (See attached image labels)

[0161] 1: Battery manufacturing equipment

[0162] 20: Differential Profile

[0163] 21: First Differential Profile

[0164] 22: Second Differential Profile

[0165] 23: Third Differential Profile

[0166] 24: Fourth Differential Profile

[0167] 100: DOC setting device

[0168] 110: Charging and discharging unit

[0169] 120: Profile Acquisition Unit

[0170] 130: Processor

[0171] 140: Storage unit

[0172] B: Battery

Claims

1. A charging depth setting device, comprising: A charging and discharging unit configured to charge a battery to a set target voltage and discharge the battery after it has been charged; A profile acquisition unit is configured to acquire a voltage profile of the battery’s capacity and voltage while the battery is being charged and discharged, and to acquire a differential profile of the battery’s capacity and differential voltage from the acquired voltage profile. and A processor, electrically connected to the charging and discharging unit, is configured to sequentially select any one of a plurality of preset voltages and set the selected preset voltage as the target voltage. When the profile acquisition unit acquires all of the plurality of differential profiles corresponding to the plurality of preset voltages, the processor is configured to acquire a feature value of the target peak value in each of the plurality of differential profiles and set the depth of charge for the battery based on the acquired feature values. The characteristic values ​​of the target peak include the capacity value, the differential voltage value, or the full width of the half maximum of the target peak, wherein the full width of the half maximum is defined as the difference between the values ​​of two independent variables that are half the maximum value of a function.

2. The charging depth setting device according to claim 1, in, The processor is configured to compare the magnitudes of the plurality of acquired feature values, select any one of a plurality of target voltages corresponding to the plurality of acquired feature values ​​as a reference voltage based on the comparison result, and set the selected reference voltage as the charging depth.

3. The charging depth setting device according to claim 2, in, The processor is configured to calculate the magnitude difference between multiple characteristic values ​​that are close to each other in the corresponding target voltage, select multiple reference characteristic values ​​with the largest calculated magnitude difference, and select any one of the multiple target voltages as the reference voltage based on the magnitude difference of the selected multiple reference characteristic values.

4. The charging depth setting device according to claim 3, in, The processor is configured to calculate the magnitude difference by comparing the magnitudes of two feature values ​​that are close to each other based on the corresponding target voltage.

5. The charging depth setting device according to claim 3, in, The processor is configured to select the target voltage on the lowest potential side of the plurality of target voltages corresponding to the selected plurality of reference feature values ​​as the reference voltage.

6. The charging depth setting device according to claim 5, in, The processor is configured to select the target voltage on the low potential side as the reference voltage when the magnitude difference between the selected plurality of reference feature values ​​is greater than or equal to a predetermined magnitude value.

7. The charging depth setting device according to claim 3, in, The processor is configured to select the target voltage at the highest potential side among the plurality of target voltages as the reference voltage when the magnitude difference between the selected plurality of reference feature values ​​is less than a predetermined magnitude value.

8. The charging depth setting device according to claim 1, in, The profile acquisition unit is configured to acquire a differential profile of the differential voltage and the capacity of the battery, wherein the differential voltage is acquired by differentiating the voltage of the battery with respect to the capacity.

9. The charging depth setting device according to claim 8, in, The processor is configured to determine at least one peak pair in each of the plurality of differential profiles, select the peak pair in which the magnitude difference between the differential voltages of the plurality of peaks included in the determined peak pair is the largest, and select the peak on the low-capacity side among the plurality of peaks included in the selected peak pair as the target peak.

10. The charging depth setting device according to claim 9, in, The processor is configured to identify two peaks located at the top and bottom of the region where the differential voltage increases with the increase of the battery capacity as a peak pair.

11. The charging depth setting device according to claim 9, in, In batteries that include graphite as the negative electrode active material, the target peak value is based on the depth of charge and LiC. 12 The peak value associated with the behavior.

12. The charging depth setting device according to claim 9, in, The processor is configured to obtain multiple normally distributed profiles by normalizing each of the multiple differential profiles and to obtain the full width at half maximum of the target peak value corresponding to each of the multiple normally distributed profiles as the feature value.

13. A battery manufacturing apparatus comprising a depth of charge setting device according to any one of claims 1 to 12.

14. A method for setting charging depth, comprising: Target voltage setting steps: sequentially select any one of a plurality of preset voltages and set the selected preset voltage as the target voltage; Charging and discharging steps: Charge the battery to the target voltage and discharge the battery after charging is complete; Voltage profile acquisition steps: Acquire voltage profiles regarding the capacity and voltage of the battery while it is being charged and discharged; Differential profile acquisition steps: Obtain a differential profile of the battery capacity and differential voltage from the obtained voltage profile; Differential profile acquisition step: Acquire all the multiple differential profiles corresponding to the multiple preset voltages; Feature value acquisition steps: Obtain the feature value of the target peak value in each of the multiple differential profiles; and Charging depth setting steps: Based on multiple acquired feature values, the charging depth of the battery is set. The characteristic values ​​of the target peak include the capacity value, the differential voltage value, or the full width of the half maximum of the target peak, wherein the full width of the half maximum is defined as the difference between the values ​​of two independent variables that are half the maximum value of a function.

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