A method for preparing a battery device, the battery device, the power consumption device, and the energy storage device.

Abstract

This application relates to the field of battery technology, and in particular to a method for preparing a battery device, a battery device, an electrical device, and an energy storage device. In the preparation process, firstly, the placement time of individual battery cells is detected, and they are classified into either a first type or a second type of battery cell. Secondly, the first type and / or second type battery cells are arranged in a tray to form a battery cell tray assembly. When the tray assembly contains only first type battery cells, the tray assembly is packaged as a first type battery cell tray assembly to obtain a battery device. When the tray assembly includes second type battery cells, the second type battery cells in the tray assembly are reworked to obtain third type battery cells. Then, the third type battery cells, or the third type battery cells and first type battery cells, are arranged in a tray to form a second type battery cell tray assembly and a third type battery cell tray assembly, respectively. Finally, the second type battery cell tray assembly and the third type battery cell tray assembly are packaged separately to obtain a battery device.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a method for preparing a battery device, a battery device, an electrical device, and an energy storage device. Background Technology

[0002] Currently, due to the excessive storage time, the capacity, internal resistance, and voltage of old batteries in the inventory cannot be matched with those of newly produced batteries. If old batteries are shipped in combination with new batteries, it will cause poor voltage difference in the battery device, thus affecting the user experience. Consequently, the old batteries have to be scrapped, resulting in excessively high production costs. Summary of the Invention

[0003] In view of this, this application provides a method for preparing a battery device, a battery device, an electrical device, and an energy storage device to solve the technical problem of old batteries affecting the overall production cost in the prior art.

[0004] This application provides a method for fabricating a battery device, the method comprising:

[0005] Provide battery cells.

[0006] The placement time of the battery cells is detected so that the battery cells include both type I and type II battery cells.

[0007] The first type of battery cells and / or the second type of battery cells are stacked together to form a battery cell stack.

[0008] When the battery cell stack only contains the first type of battery cell, the battery cell stack is packaged as the first battery cell stack to obtain a battery device.

[0009] When a battery cell assembly includes a second type of battery cell, the second type of battery cell in the battery cell assembly is reworked to obtain a third type of battery cell.

[0010] The third type of battery cell, or the third type of battery cell and the first type of battery cell, are assembled into a tray to form a second battery cell tray and a third battery cell tray, respectively. The second battery cell tray and the third battery cell tray are then packaged separately to obtain a battery device.

[0011] The placement time of the first type of battery cell is t. 01 , and t 01 Satisfying t 01 <7 days, the placement time of the second type of battery cell is t 02 , and t 02 Satisfy t 02 ≥7 days.

[0012] In one possible implementation, the steps of assembling a third type of battery cell, or a third type of battery cell and a first type of battery cell, into a tray to form a second battery cell tray group and a third battery cell tray group, and then packaging the second battery cell tray group and the third battery cell tray group separately to obtain a battery device include:

[0013] The battery cells in the second and / or third battery cell arrays are placed synchronously at the first time.

[0014] Detect the self-discharge rate of each cell in the second and / or third battery cell array.

[0015] Detect the pressure difference between individual cells within the second and / or third battery cell arrays.

[0016] The second and / or third battery cell stacks are packaged to obtain a battery device.

[0017] Among them, the self-discharge rate of each battery cell in the second battery cell array is α2, and α2 satisfies α2≤0.04% / day. The voltage difference between each battery cell in the second battery cell array is β2, and β2 satisfies β2≤0.005mV. The self-discharge rate of each battery cell in the third battery cell array is α3, and α3 satisfies α3≤0.04% / day. The voltage difference between each battery cell in the third battery cell array is β3, and β3 satisfies β3≤0.005mV.

[0018] In one possible implementation, the step of detecting the self-discharge rate of each cell in the second and / or third battery cell array includes:

[0019] The first time includes the first time detection point and the second time detection point.

[0020] The voltage of each battery cell is detected at the first and second time points.

[0021] The voltage-state-of-charge curve of the battery cell is used for querying, and the voltages at the first and second time detection points are converted into the corresponding states of charge.

[0022] The self-discharge rate of each battery cell is calculated.

[0023] Among them, the first detection point is t 11 The second time point is t. 12 , and t 11 and t 12 Satisfy t 12 >t 11 .

[0024] In one possible implementation, the step of detecting the pressure difference between individual cells within the second or third battery cell array includes:

[0025] The first time also includes the third time detection point.

[0026] The voltage of each battery cell is detected at the third time point.

[0027] The maximum and minimum voltages at the third time point are selected for calculation to obtain the voltage difference between each battery cell.

[0028] The third time point is t. 13 , and t 11 t 12 and t 13 Satisfy t 13 >t 11 , t 13 >t 12 The maximum voltage of a single battery cell at the third time point is β. max The minimum voltage of a single battery cell at the third time point is β. min , and β max and β min Satisfy β max -β min ≤0.005mv.

[0029] In one possible implementation, t 11 It also satisfies 24h≤t 11 ≤72h,t 12 It also satisfies 72h < t 12 ≤120h,t 13 It also satisfies 120h < t 13 ≤168h.

[0030] In one possible implementation, the voltage difference between each battery cell in the first battery cell array is β1, and β1 satisfies β1≤0.005mV.

[0031] In one possible implementation, the preparation method further includes, prior to providing the battery cell:

[0032] Provide sample battery cells.

[0033] Establish a table of rework charge states for sample battery cells.

[0034] When a battery cell assembly includes second-type battery cells, the steps to rework the second-type battery cells within the battery cell assembly to obtain third-type battery cells include:

[0035] The rework charge state correspondence table is used to query and the second type of battery cell is reworked to the corresponding charge state to obtain the third type of battery cell.

[0036] In one possible implementation, the step of establishing a rework state-of-charge correspondence table for sample battery cells includes:

[0037] The sample battery cells were left to stand for a second time, which included multiple time sampling points.

[0038] The voltage of each individual battery cell in the sample was measured at various time points to plot a voltage-time curve.

[0039] Calculate the slope of the line connecting each time sampling point, and classify multiple time sampling points to form multiple time periods.

[0040] The rework state-of-charge curves of individual sample cells are used for lookup, and combined with voltage-time curves, to establish a table corresponding to the rework state-of-charge curves.

[0041] The second time is t2, and t2 satisfies 7 days ≤ t2 ≤ 180 days.

[0042] In one possible implementation, the slope of the line connecting the sampling points at each time point in the second time period is k, and k satisfies 0 ≤ k ≤ 0.05.

[0043] In one possible implementation, the multiple time periods include a first time period, a second time period, a third time period, a fourth time period, a fifth time period, and a sixth time period.

[0044] The first time period is t. 21 , and t 21 Satisfying 7 days ≤ t 21 <14 days, the second time period is t 22 , and t 22 Satisfying 14 days ≤ t 22 <21 days, the third time period is t 23 , and t 23 Satisfying 21 days ≤ t 23 <30 days, the fourth time period is t 24 , and t 24 Satisfying 30 days ≤ t 24 <60 days, the fifth time period is t 25 , and t 25 Satisfying 60 days ≤ t 25 <90 days, the sixth time period is t 26 , and t 26 Satisfying 90 days ≤ t 26 ≤180 days.

[0045] In one possible implementation, the rework charge state corresponding to each time period includes a first rework charge state, a second rework charge state, a third rework charge state, a fourth rework charge state, a fifth rework charge state, and a sixth rework charge state.

[0046] The first rework charge state is SOC1, and SOC1 satisfies 20% < SOC1 ≤ 21%. The second rework charge state is SOC2, and SOC2 satisfies 19.5% < SOC2 ≤ 20%. The third rework charge state is SOC3, and SOC3 satisfies 19.1% < SOC3 ≤ 19.5%. The fourth rework charge state is SOC4, and SOC4 satisfies 18.8% < SOC4 ≤ 19.1%. The fifth rework charge state is SOC5, and SOC5 satisfies 18.6% < SOC5 ≤ 18.8%. The sixth rework charge state is SOC6, and SOC6 satisfies 18.5% ≤ SOC6 ≤ 18.6%.

[0047] This application also provides a battery device, which is manufactured using the preparation method described in any of the above claims, and includes one or more of a battery module, a battery pack, and an energy storage battery.

[0048] This application also provides an electrical device, which includes a battery device as described above, the battery device being used to provide electrical energy.

[0049] This application also provides an energy storage device, which includes a battery device as described above, the battery device being used to store electrical energy.

[0050] The beneficial effects of this application are as follows: Classifying and screening battery cells based on placement time ensures that the performance of each battery cell within a tray is similar or completely consistent after assembly, which improves the stability and reliability of the battery device during operation and extends its service life. Simultaneously, it allows for differentiated processing of different categories of battery cells, enabling the rework of cells that do not meet the assembly criteria for recycling, thus improving resource utilization and reducing the production cost of the battery device. Furthermore, the assembly process for battery cells that meet the assembly criteria offers greater flexibility, reducing or even eliminating waiting time for assembly, thereby improving the production efficiency of the battery device.

[0051] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0052] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the structure of a single battery cell provided in this application in one embodiment;

[0054] Figure 2 This is a schematic diagram of the structure of the first battery cell disk assembly provided in this application in one embodiment;

[0055] Figure 3 This is a schematic diagram of the structure of the second battery cell disk assembly provided in this application in one embodiment;

[0056] Figure 4 This is a schematic diagram of the structure of the third battery cell array provided in this application in one embodiment;

[0057] Figure 5 This is an exploded view of one embodiment of the battery device provided in this application;

[0058] Figure 6 This is the rework charge state correspondence table provided in this application;

[0059] Figure 7 This is a flowchart of the offline battery fabrication device provided in this application;

[0060] Figure 8 This is a flowchart of the online preparation of the rework charge state correspondence table provided in this application;

[0061] Figure 9 This is a schematic diagram of the structure of the electrical device provided in this application in one embodiment;

[0062] Figure 10 This is a schematic diagram of the structure of the energy storage device provided in this application in one embodiment.

[0063] Explanation of reference numerals in the attached figures:

[0064] 1-Battery cell;

[0065] 11-First type of battery cell;

[0066] 12-Second type of battery cell;

[0067] 13-Third type of battery cell;

[0068] 2-Battery cell array;

[0069] 21-First battery cell array;

[0070] 22 - Second battery cell array;

[0071] 23 - Third battery cell array;

[0072] 3-Battery device;

[0073] 4- Electrical appliances;

[0074] 5-Energy storage device.

[0075] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0076] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0077] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0078] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0079] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0080] Embodiments of this application provide a method for manufacturing a battery device, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 7 As shown, the preparation method includes:

[0081] Provide 1 battery cell;

[0082] The placement time of battery cell 1 is detected so that battery cell 1 includes a first type of battery cell 11 and a second type of battery cell 12;

[0083] The first type of battery cell 11 and / or the second type of battery cell 12 are arranged in a tray to form a battery cell tray group 2.

[0084] When the battery cell tray 2 contains only the first type of battery cell 11, the battery cell tray 2 is packaged as the first battery cell tray 21 to obtain the battery device 3.

[0085] When the battery cell assembly 2 includes a second type of battery cell 12, the second type of battery cell 12 in the battery cell assembly 2 is reworked to obtain a third type of battery cell 13.

[0086] The third type of battery cell 13, or the third type of battery cell 13 and the first type of battery cell 11, are assembled into a tray to form a second battery cell tray 22 and a third battery cell tray 23, respectively. The second battery cell tray 22 and the third battery cell tray 23 are then packaged to obtain the battery device 3.

[0087] The placement time of the first type of battery cell 11 is t. 01 , and t 01 Satisfy t 01 <7 days, the placement time of the second type of battery cell 12 is t 02 , and t 02 Satisfy t 02 ≥7 days.

[0088] In this embodiment, the placement time of the provided battery cell 1 is detected to identify the category of the battery cell 1, so that different categories of battery cells 1 can be differentiated in the subsequent process. This helps to reduce the possibility of mixing different categories of battery cells 1, thereby ensuring the working performance and service life of the battery device 3.

[0089] Since the performance parameters of battery cell 1 (such as capacity, internal resistance, voltage, etc.) will change as the storage time increases, the battery cells 1 provided are classified by using the storage time as the classification standard (that is, battery cells 1 are divided into first-class battery cells 11 with shorter storage time and second-class battery cells 12 with longer storage time). This ensures that the performance parameters of battery cells 1 of the same category are similar or even the same. This is not only conducive to centralized and unified processing to simplify the production process and improve production efficiency, but also conducive to improving the performance consistency of battery cell array 2, thereby improving the stability and reliability of battery device 3 during operation.

[0090] Optionally, the placement time of battery cell 1 can be calculated from the moment it completes all factory inspections and is officially registered in the warehouse (i.e., enters the warehouse management system), and the calculation is based on natural days to unify the calculation standard and avoid the uncertainty caused by waiting and transfer time.

[0091] The placement time of battery cell 1 is not included in the placement time on the day of its entry into the warehouse. That is, the placement time of battery cell 1 within 24 hours after its entry into the warehouse is counted as 0 days. Starting from 0:00 on the day following its entry into the warehouse, the placement time of battery cell 1 increases by 1 day every 24 hours. The general formula for calculating the placement time is: Placement time = Outbound date - Inbound date - 1. For example, if the inbound date of battery cell 1 is May 1 and the outbound date is May 5, then May 5 - May 1 = 4 days, 4 - 1 = 3 days. Therefore, the placement time of battery cell 1 is 3 days, which is the first type of battery cell 11.

[0092] Optionally, the provided battery cell 1 can be one or multiple.

[0093] For example, when each batch provides one battery cell 1, each battery cell 1 can be tested individually, which helps reduce testing errors and improve the accuracy of testing results, thereby ensuring the reliability of battery cell 1 classification. Alternatively, when each batch provides multiple battery cells 1, the battery cells 1 can be tested in batches, which helps improve testing efficiency and thus improves the production efficiency of battery device 3.

[0094] In the batch testing of multiple battery cells 1, the testing device can simultaneously test the placement time of multiple battery cells 1 to improve testing efficiency, or the testing device can test the placement time of each battery cell 1 one by one to reduce the feeding frequency of battery cells 1.

[0095] Optionally, the testing of individual battery cells 1 and the assembly of the battery cells can be carried out in conjunction with each other, or they can be carried out separately and independently.

[0096] For example, regardless of whether each batch provides one or more battery cells 1, after the placement time of each battery cell 1 is tested, it can be placed in the corresponding tray immediately according to its category to achieve linkage between testing and tray assembly. Alternatively, after all battery cells 1 have been tested, battery cells 1 of the same category can be placed in the same tray according to their category to achieve independence between testing and tray assembly.

[0097] In the process of assembling the first type of battery cell 11 and / or the second type of battery cell 12 into a battery cell array 2, the first type of battery cell 11 can be assembled into an array alone, the second type of battery cell 12 can be assembled into an array alone, or the first type of battery cell 11 and the second type of battery cell 12 can be assembled into an array together.

[0098] For example, when one battery cell 1 is provided in each batch, all first-type battery cells 11 and all second-type battery cells 12 can be placed in the same tray according to the placement time of each battery cell 1. After each tray is filled, multiple first-type battery cells 11 and multiple second-type battery cells 12 can be individually trayed.

[0099] For example, when multiple battery cells 1 are provided in each batch, the multiple battery cells 1 can be grouped into trays in advance before the testing placement time, so as to conduct centralized and unified testing and avoid the risk of inaccurate test results or some battery cells 1 not being detected due to scattered distribution. After the testing is completed, the battery cells 1 in the tray can be a tray group consisting entirely of first-type battery cells 11 or second-type battery cells 12, and there is no need to re-sort and re-group them in the future. It can also be a mixed tray group between first-type battery cells 11 and second-type battery cells 12, and can be re-sorted and re-grouped in the future according to the needs.

[0100] Optionally, during the process of re-sorting and repacking the mixed tray group including the first type of battery cells 11 and the second type of battery cells 12, the more numerous first type of battery cells 1 (e.g., the first type of battery cells 11) can be retained in the tray group according to the ratio of the number of the first type of battery cells 11 and the second type of battery cells 12 in the mixed tray group, while the less numerous second type of battery cells 1 (e.g., the second type of battery cells 12) can be removed from the tray group and replaced with battery cells 1 of the same type as the more numerous first type of battery cells 1 (i.e., the first type of battery cells 11). This allows for priority completion of the repacking of any type of battery cells 1, which helps to reduce waiting time, improve the efficiency of re-sorting and repacking, and thus improve the production efficiency of the battery device 3.

[0101] It should be noted that in other embodiments, the battery cells can be reclassified and reassembled according to other requirements such as assembly conditions and shipping conditions. For example, if the shipping condition is that the battery cell assembly 2 contains only first-type battery cells 11, then even if the number of first-type battery cells 11 in the mixed assembly is less than the number of second-type battery cells 12, the second-type battery cells 12 should be removed from the assembly and replaced with the same number of first-type battery cells 11 to meet the shipping conditions.

[0102] When all battery cells 1 in the battery cell tray 2 are first-type battery cells 11, the performance parameters of each first-type battery cell 11 are relatively stable due to the short placement time of the first-type battery cells 11. As a result, the performance parameter differences between multiple first-type battery cells 11 are small. Therefore, the battery cell tray 2 can be used as the first battery cell tray 21. Moreover, the first battery cell tray 21 has high performance consistency, so the first battery cell tray 21 can be directly packaged to obtain the battery device 3.

[0103] When all the battery cells 1 in the battery cell tray 2 are second-type battery cells 12, the performance parameters of each second-type battery cell 12 are inconsistent due to the long storage time. This results in significant differences in performance parameters among multiple second-type battery cells 12. Therefore, it is necessary to first rework the second-type battery cells 12 into third-type battery cells 13 to adjust or restore their various performance parameters, thereby reducing the differences in performance parameters among multiple third-type battery cells 13. Then, the battery cell tray 2 is used as the second battery cell tray 22, which also has high performance consistency. Thus, the second battery cell tray 22 can be directly packaged to obtain the battery device 3. This helps to reduce the scrap rate of the second-type battery cells 12, increase the utilization rate of the second-type battery cells 12, and reduce the production cost of the battery device 3.

[0104] Accordingly, when the battery cell 1 in the battery cell array 2 includes both the first type of battery cell 11 and the second type of battery cell 12, the first type of battery cell 11 can be kept in the original array, and the second type of battery cell 12 can be taken out for rework. After the second type of battery cell 12 is converted into the third type of battery cell 13, it can be put back into the original array to reassemble the array.

[0105] Among them, since the third type of battery cell 13 is a reworked battery cell 1, its placement time is similar to or the same as that of the first type of battery cell 11 (i.e., the placement time of the third type of battery cell 13 is t). 03 , and t 03 Satisfy t 03 (<7 days), the performance parameters of each third type of battery cell 13 are relatively stable, so the performance parameter differences between multiple third type of battery cells 13 or between the third type of battery cell 13 and the first type of battery cell 11 are small. Therefore, the battery cell tray 2 can be used as the third battery cell tray 23, and the third battery cell tray 23 has high performance consistency. Thus, the third battery cell tray 23 can be directly packaged to obtain the battery device 3.

[0106] Optionally, when the battery cell tray 2 includes both first-type battery cells 11 and second-type battery cells 12, the first-type battery cells 11 retained in the original tray can be trayed with other first-type battery cells 11 to form a first battery cell tray 21 for packaging. Alternatively, they can be trayed with other third-type battery cells 13 to form a third battery cell tray 23 for packaging. This eliminates the need to wait for the second-type battery cells 12 in the original tray to be reworked, thereby reducing the waiting time for the first-type battery cells 11 in the original tray and improving the tray assembly efficiency of the battery cell tray 2. This, in turn, improves the production efficiency of the battery device 3 and better meets actual production needs.

[0107] Correspondingly, after the second type of battery cell 12 in the original tray is reworked into a third type of battery cell 13, it can be trayed with other first type of battery cells 11 to form a third battery cell tray 23 for packaging. Alternatively, it can be trayed with other third type of battery cells 13 to form a second battery cell tray 22 for packaging. This achieves seamless connection between the first type of battery cells 11 and the third type of battery cells 13 during the tray assembly process, which helps to improve the flexibility of assembling the battery cell tray 2 and is more in line with actual production needs.

[0108] Optionally, the placement time t of the first type of battery cell 11 01 Specifically, the placement time can be 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, etc., for the third type of battery cell 13. 03 Specifically, the placement time can be 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, etc., for the second type of battery cell 12. 02 Specifically, the duration can be 7 days, 14 days, 21 days, 30 days, 42 days, 60 days, 70 days, 80 days, 90 days, 100 days, 110 days, 120 days, 130 days, 140 days, 150 days, 160 days, 170 days, 180 days, 190 days, 200 days, etc.

[0109] Optionally, the placement time of the first type of battery cell 11 can be 3 days ≤t 01 <7 days, the placement time for the third type of battery cell 13 can be 3 days ≤t 03 <7 days. At this time, the solid electrolyte interphase (SEI) membrane of the first type of battery cell 11 and the third type of battery cell 13 has been formed, and its performance parameters such as voltage, internal resistance and capacity have been fully stabilized, so as to obtain a battery cell array 2 with smaller pressure drop and more balanced performance after assembly, thereby obtaining a battery device 3 with higher quality.

[0110] Optionally, the placement time of the second type of battery cell 12 can be 7 days ≤t 02<180 days. At this time, the SEI film of the second type of battery cell 12 continues to grow, and its performance parameters such as voltage, internal resistance, and capacity begin to decay. This not only avoids the risk of wasting rework resources by reworking the battery cell 1 which is in the stable period, but also avoids the risk of reduced rework effect and increased rework cost due to excessive degradation of the second type of battery cell 12. This helps to achieve a balance between scrap cost and rework cost, which is more in line with actual production needs.

[0111] In summary, the preparation method of this embodiment can classify battery cells 1 according to their storage time, thereby reducing the possibility of mixing battery cells 1 with different performance parameters. This ensures the performance consistency of each battery cell 1 within the battery cell array 2, which in turn improves the stability and reliability of the battery device 3 during operation and extends its service life. Furthermore, classifying the battery cells 1 allows for differentiated processing of different categories. Not only can non-compliant battery cells 1 (i.e., second-category battery cells 12) be reworked for recycling, reducing the scrap rate of such cells and thus lowering the production cost of the battery device 3 and improving resource utilization, but it can also be integrated with warehouse management processes for more precise storage management of battery cells 1, improving the turnover rate of stored battery cells 1 and achieving automated management. In addition, compliant battery cells 1 (i.e., first-category battery cells 11 and third-category battery cells 13) have high flexibility in the array assembly process, reducing or even eliminating waiting time, thereby improving the production efficiency of the battery device 3.

[0112] In one specific implementation, such as Figure 3 , Figure 4 and Figure 7 As shown, the steps of assembling the third type of battery cell 13, or the third type of battery cell 13 and the first type of battery cell 11 into a tray to form a second battery cell tray group 22 and a third battery cell tray group 23 respectively, and packaging the second battery cell tray group 22 and the third battery cell tray group 23 respectively to obtain the battery device 3 include:

[0113] The battery cells 1 in the second battery cell array 22 and / or the third battery cell array 23 are placed synchronously at the first time.

[0114] The self-discharge rate of each battery cell 1 in the second battery cell array 22 and / or the third battery cell array 23 is detected.

[0115] Detect the pressure difference between each battery cell 1 in the second battery cell array 22 and / or the third battery cell array 23;

[0116] The second battery cell array 22 and / or the third battery cell array 23 are packaged to obtain the battery device 3.

[0117] Among them, the self-discharge rate of each battery cell 1 in the second battery cell array 22 is α2, and α2 satisfies α2≤0.04% / day. The voltage difference between each battery cell 1 in the second battery cell array 22 is β2, and β2 satisfies β2≤0.005mV. The self-discharge rate of each battery cell 1 in the third battery cell array 23 is α3, and α3 satisfies α3≤0.04% / day. The voltage difference between each battery cell 1 in the third battery cell array 23 is β3, and β3 satisfies β3≤0.005mV.

[0118] In this embodiment of the application, during the process of assembling the third type of battery cell 13, multiple third type of battery cells 13 can be assembled into a second battery cell assembly 22. After the second battery cell assembly 22 is packaged, the battery device 3 can be obtained. Alternatively, the third type of battery cells 13 and the first type of battery cells 11 can be mixed and assembled into a third battery cell assembly 23. After the third battery cell assembly 23 is packaged, the battery device 3 can be obtained.

[0119] First, since both the second battery cell array 22 and the third battery cell array 23 contain reworked third-type battery cells 13, by placing the entire battery cell array 2 synchronously at the first moment, not only can the residual effects of the third-type battery cells 13 caused by the difference in placement conditions before rework be reduced or even eliminated, but the electrochemical state of each battery cell 1 in the same battery cell array 2 can also be ensured to reach a new equilibrium under the same placement conditions, so as to provide a more accurate benchmark for subsequent testing, which is conducive to improving the accuracy of subsequent testing, thereby improving the production quality of the battery device 3 to meet the needs of customers.

[0120] Optionally, within the third battery cell array 23, the placement time of the first type of battery cell 11 can be 0 days ≤ t. 01 Within 3 days, the electrochemical state of the first type of battery cell 11 and the reworked third type of battery cell 13 is similar. Neither has formed an SEI film, and their performance parameters, such as voltage, internal resistance, and capacity, are not yet fully stable. Therefore, by simultaneously placing the battery cells 1 within the third battery cell array 23 for the first time, it is possible to ensure a smaller voltage difference and more balanced performance among the battery cells 1 within the array. This also reduces the likelihood of lithium plating, thus facilitating the acquisition of a higher-quality battery device 3.

[0121] Secondly, the self-discharge rate of each battery cell 1 in the battery cell array 2 can be detected in the first time, so as to further screen out battery cells 1 with similar self-discharge rates, reduce the possibility of voltage imbalance in the entire battery device 3 caused by excessively fast discharge of individual battery cells 1, thereby avoiding the risk of overcharging or over-discharging of the battery device 3 during use, which is conducive to extending the service life of the battery device 3 and improving the safety of the battery device 3 during use.

[0122] Optionally, the self-discharge rate of each battery cell 1 in the second battery cell array 22 can be 0.01% / day, 0.012% / day, 0.014% / day, 0.016% / day, 0.018% / day, 0.02% / day, 0.022% / day, 0.024% / day, 0.026% / day, 0.028% / day, 0.03% / day, 0.032% / day, 0.034% / day, 0.036% / day, 0.038% / day, 0.04% / day, etc.

[0123] Optionally, the self-discharge rate of each battery cell 1 in the third battery cell array 23 can be 0.01% / day, 0.011% / day, 0.013% / day, 0.015% / day, 0.017% / day, 0.019% / day, 0.021% / day, 0.023% / day, 0.025% / day, 0.027% / day, 0.029% / day, 0.031% / day, 0.033% / day, 0.035% / day, 0.037% / day, 0.039% / day, 0.04% / day, etc.

[0124] Therefore, by setting α2 to satisfy α2≤0.04% / day and α3 to satisfy α3≤0.04% / day, this embodiment can ensure that the battery device 3 has the ability to store for a long time and extend the service life of the battery device 3.

[0125] Then, in the first instance, the voltage difference between each battery cell 1 in the battery cell array 2 can be detected, so as to further screen out battery cells 1 with similar open circuit voltages, which is beneficial to improve the overall usable capacity and charging efficiency of the battery device 3, so as to ensure the stability and reliability of the battery device 3 during operation.

[0126] Optionally, the voltage difference between each battery cell 1 in the second battery cell array 22 can be 0.001mV, 0.002mV, 0.003mV, 0.004mV, 0.005mV, etc.

[0127] Optionally, the voltage difference between each battery cell 1 in the third battery cell array 23 can be 0.001mV, 0.002mV, 0.003mV, 0.004mV, 0.005mV, etc.

[0128] Therefore, by setting β2 to satisfy β2≤0.005mv and β3 to satisfy β3≤0.005mv, this embodiment can ensure that the battery device 3 has high consistency and improve the working reliability of the battery device 3.

[0129] Optionally, the voltage range of each third-type battery cell 13 can be 3.262mV, 3.263mV, 3.264mV, 3.265mV, 3.266mV, 3.267mV, etc.

[0130] In one specific implementation, such as Figure 3 , Figure 4 and Figure 7 As shown, the steps for detecting the self-discharge rate of each battery cell 1 within the second battery cell array 22 and / or the third battery cell array 23 include:

[0131] The first time includes the first-time detection point and the second-time detection point;

[0132] The voltage of each battery cell 1 is detected at the first and second time points.

[0133] Based on the voltage-state-of-charge curve corresponding to battery cell 1, the voltages at the first and second time detection points will be converted into the corresponding states of charge.

[0134] The self-discharge rate of each battery cell 1 is calculated.

[0135] Among them, the first detection point is t 11 The second time point is t. 12 , and t 11 and t 12 Satisfy t 12 >t11.

[0136] In this embodiment of the application, the first time may include multiple time detection points. The following description uses the first time detection point and the second time detection point as examples.

[0137] First, a first time detection point and a second time detection point are selected within the first time period so that a time period can be formed between the two time detection points. This is used to calculate the performance change trend of each battery cell 1 within this time period, so as to accurately reflect the self-discharge rate of each battery cell 1 and thus ensure the accuracy when the third type of battery cells 13 are stacked together.

[0138] Among them, the first time detection point and the second time detection point satisfy t 12 >t 11This allows for a time difference between the first and second time detection points, ensuring that the performance parameters of each battery cell 1 show a clear trend between the two time detection points. It also avoids frequent testing of each battery cell 1 by staff within the first time period, thus optimizing testing efficiency and improving the accuracy of test results.

[0139] Optionally, the first detection point can be the time when each battery cell 1 just enters a stable state, and the second detection point can be the time when each battery cell 1 has entered a stable state for a period of time, so as to detect the degradation process of various performance parameters of each battery cell 1 after entering a stable state, which is beneficial to screen out battery cells 1 with longer service life, so as to extend the service life of battery device 3.

[0140] Secondly, performing voltage detection on all battery cells 1 within the same battery cell array 2 at the same time (or within a very short time) helps to reduce or even eliminate errors that may be introduced due to asynchronous detection times, thereby improving the accuracy of subsequent calculation results.

[0141] Then, based on the voltage of each battery cell 1 at the first and second time detection points, the voltage-state-of-charge curve of that model of battery cell 1 is queried, so that the state of charge of each battery cell 1 at the first and second time detection points can be obtained. In order to calculate the self-discharge rate of each battery cell 1 in that time period through the state of charge, it is convenient for the staff to screen according to the self-discharge rate, thereby ensuring the product quality of the battery device.

[0142] In one specific implementation, such as Figure 3 , Figure 4 and Figure 7 As shown, the steps for detecting the pressure difference between individual battery cells 1 within the second battery cell array 22 and / or the third battery cell array 23 include:

[0143] The first time also includes the third time detection point;

[0144] Detect the voltage of each battery cell 1 at the third time point;

[0145] The maximum and minimum voltages at the third time detection point are selected for calculation to obtain the voltage difference between each battery cell 1.

[0146] The third time point is t. 13 , and t 11 t 12 and t 13 Satisfy t 13 >t 11 , t 13 >t 12The maximum voltage of battery cell 1 at the third time point is β. max The minimum voltage of battery cell 1 at the third time point is β. min , and β max and β min Satisfy β max -β min ≤0.005mv.

[0147] In this embodiment, the first time also includes a third time detection point, and the first time detection point, the second time detection point, and the third time detection point respectively satisfy t 12 >t 11 , t 13 >t 11 , t 13 >t 12 That is, the third time detection point is located after the second time detection point, so that the step of detecting the voltage difference between each battery cell 1 is located after the step of detecting the self-discharge rate of each battery cell 1. This ensures that the battery cells 1 participating in the voltage detection are all high-quality battery cells 1, so as to avoid the risk of discovering low-quality battery cells 1 after voltage detection and reworking them. This reduces the possibility of repeatedly detecting the voltage difference of the same battery cell array 2, which helps to reduce unnecessary repetitions and improve detection efficiency and production efficiency.

[0148] Since each battery cell 1 in the second battery cell array 22 and the third battery cell array 23 has been stationary from the first time detection point to the second time detection point and then to the third time detection point, the voltage detected at the third time detection point has high stability, which is beneficial to improving the accuracy of subsequent voltage difference calculation.

[0149] Simultaneously, by selecting the maximum and minimum voltages from multiple detection results for calculation, the maximum voltage difference range of the second battery cell array 22 or the third battery cell array 23 can be obtained, and when this range satisfies β... max -β min When the voltage is ≤0.005mV, it can ensure that the voltage difference between each battery cell 1 is small, which is conducive to improving the voltage consistency of the battery device 3, thereby improving the safety and reliability of the battery device 3 during operation.

[0150] Optionally, the voltage difference between the maximum and minimum voltages can be 0.001mV, 0.002mV, 0.003mV, 0.004mV, 0.005mV, etc.

[0151] In addition, the self-discharge rate and voltage difference of each battery cell 1 are tested sequentially, so that the two test results can be mutually verified, which helps to improve the accuracy and reliability of the test results. That is, if the voltage difference between a group of battery cells 1 is small, then the self-discharge rate of each battery cell 1 in the group is also low, and the self-discharge rates of each battery cell 1 are similar. Therefore, it can be inferred that the group of battery cells 1 has a long service life and high working reliability, and thus it can be inferred that the battery device 3 composed of the group of battery cells 1 has good working performance.

[0152] In one specific implementation, t11 also satisfies 24h≤t 11 ≤72h, t12 also satisfies 72h<t 12 ≤120h, t13 also satisfies 120h<t 13 ≤168h.

[0153] In this embodiment, the first time detection point is the starting point for calculating the self-discharge rate of each battery cell 1. When t 11 Satisfying 24h≤t 11 When the time interval is ≤72h, the electrochemical state of each battery cell 1 approaches stability. At this point, detecting each battery cell 1 at this time yields accurate and reliable results, laying the foundation for subsequent calculations and helping to reduce the error range and improve the accuracy of the final calculation. The second time detection point is the termination point for calculating the self-discharge rate of each battery cell 1. When t... 12 Satisfying 72h < t 12 When the time interval is ≤120h, the electrochemical state of each battery cell 1 begins to decay. At this point, detecting and calculating the voltage difference between each battery cell 1 not only yields high-precision and high-reliability results but also simplifies the inspection process, reduces waiting time, and improves inspection efficiency. The third time point is the time point for calculating the voltage difference between each battery cell 1. 13 Satisfying 120h < t 13 When the time is ≤168h, each battery cell 1 has been left to stand for a relatively long time, and the electrochemical state of each battery cell 1 has high stability. At this time, testing and calculation of each battery cell 1 can not only obtain high-precision and high-reliability test results, but also avoid the risk that each battery cell 1 needs to be reworked due to being left for too long. This is conducive to ensuring the product quality of the battery device 3, improving the production efficiency of the battery device 3, and reducing the production cost of the battery device 3.

[0154] Optionally, the first detection point can be 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h, 48h, 50h, 52h, 54h, 56h, 58h, 60h, 62h, 64h, 66h, 68h, 70h, 72h, etc.

[0155] Optionally, the second time detection point can be 73h, 74h, 76h, 78h, 80h, 82h, 84h, 86h, 88h, 90h, 92h, 94h, 96h, 98h, 100h, 102h, 104h, 106h, 108h, 110h, 112h, 114h, 116h, 118h, 120h, etc.

[0156] Optionally, the third time detection point can be 121h, 122h, 124h, 126h, 128h, 130h, 132h, 134h, 136h, 138h, 140h, 142h, 144h, 146h, 148h, 150h, 152h, 154h, 156h, 158h, 160h, 162h, 164h, 166h, 168h, etc.

[0157] In one specific implementation, such as Figure 2 As shown, the voltage difference between each battery cell 1 in the first battery cell array 21 is β1, and β1 satisfies β1≤0.005mV.

[0158] In this embodiment of the application, when each battery cell 1 in the battery cell tray 2 is a first type of battery cell 11, the battery cell tray 2 is packaged as a first battery cell tray 21 to obtain the battery device 3.

[0159] Among them, the placement time of the first type of battery cell 11 satisfies 3 days ≤ t 01 Within 7 days, the voltage difference between each first-type battery cell 11 meets the requirement of β1≤0.005mV, so that the newly produced battery cell 1 and the reworked battery cell 1 can be subjected to the same voltage test standard. By detecting the voltage difference between each battery cell 1 in the first battery cell tray 21 before packaging, it is not only beneficial to improve the performance consistency of the first battery cell tray 21 and improve the stability and reliability of the battery device 3 during operation, but also beneficial to improve the production quality of the battery device 3 composed of first-type battery cells 11.

[0160] Meanwhile, when the voltage detection standards of the first battery cell disk group 21, the second battery cell disk group 22, and the third battery cell disk group 23 are the same, a good series and parallel connection effect can be achieved between each battery cell disk group 2, which is conducive to improving the connection flexibility of the battery cell disk group 2 during use and improving the working performance of the battery device 3.

[0161] In addition, adopting the same inspection standards can reduce the management difficulty and cost of battery cell 1, and better meet actual usage needs.

[0162] Optionally, the voltage difference between each battery cell 1 in the first battery cell array 21 can be 0.001mV, 0.002mV, 0.003mV, 0.004mV, 0.005mV, etc.

[0163] Optionally, within the first battery cell array 21 and the third battery cell array 23, the voltage range of the first type of battery cell 11 can specifically be 3.262mV, 3.263mV, 3.264mV, 3.265mV, 3.266mV, 3.267mV, etc.

[0164] Optionally, within the third battery cell array 23, the voltage of the third type of battery cell 13 is less than or equal to the voltage of the first type of battery cell 11.

[0165] In one possible implementation, before detecting the voltage difference between each battery cell 1 in the first battery cell array 21, the self-discharge rate of each battery cell 1 in the first battery cell array 21 can also be detected, so as to screen the first type of battery cells 11 and select higher quality battery cells 1 for arraying, which is beneficial to improving the production quality of the battery device 3.

[0166] The self-discharge rate of each battery cell 1 in the first battery cell array 21 is α1, and α1 satisfies α1≤0.04% / day. Specifically, the self-discharge rate of each battery cell 1 in the first battery cell array 21 can be 0.01% / day, 0.012% / day, 0.014% / day, 0.016% / day, 0.018% / day, 0.02% / day, 0.022% / day, 0.024% / day, 0.026% / day, 0.028% / day, 0.03% / day, 0.032% / day, 0.034% / day, 0.036% / day, 0.038% / day, 0.04% / day, etc.

[0167] In summary, such as Figure 7As shown, in the process of offline battery device 3, the placement time t0 of the provided battery cell 1 is first checked to see if it satisfies t0 < 7 days. If it does, the battery cell 1 is a first-type battery cell 11; if it does not, the battery cell 1 is a second-type battery cell 12. Then, the first-type battery cells 11 and / or the second-type battery cells 12 are arranged in a tray to form a battery cell tray group 2. The battery cells 1 in the battery cell tray group 2 include at least three tray arrangements: tray arrangement of first-type battery cells 11, tray arrangement of second-type battery cells 12, and tray arrangement of the second-type battery cells 12. A mixed array of first-type battery cells 11 and second-type battery cells 12 is assembled into a disk. Then, it is detected whether the battery cell disk array 2 contains only first-type battery cells 11 (or whether it includes second-type battery cells 12). If the battery cell disk array 2 contains only first-type battery cells 11, it is designated as the first battery cell disk array 21. The self-discharge rate α1 of each battery cell 1 and the voltage difference β1 between each battery cell 1 are detected. When α1 satisfies α1≤0.04% / day and β1 satisfies β1≤0.005mV, the first battery cell disk array 21 is then... A battery cell tray 21 is packaged to obtain a battery device 3; simultaneously, when the battery cell tray 2 includes a second type of battery cell 12, the second type of battery cell 12 in the battery cell tray 2 is reworked to obtain a third type of battery cell 13; when the third type of battery cell 13 is packaged as a battery cell tray 2, the battery cell tray 2 is used as a second battery cell tray 22, and the self-discharge rate α2 of each battery cell 1 in the second battery cell tray 22 and the voltage difference β2 between each battery cell 1 are detected. When α2 satisfies α2≤0.04% / day, and β2 When β2 ≤ 0.005mV, the second battery cell array 22 is packaged to obtain the battery device 3. When the third type of battery cell 13 and the first type of battery cell 11 are grouped into a battery cell array 2, the battery cell array 2 is used as the third battery cell array 23. The self-discharge rate α3 of each battery cell 1 in the third battery cell array 23 and the voltage difference β3 between each battery cell 1 are detected. When α3 satisfies α3 ≤ 0.04% / day and β3 satisfies β3 ≤ 0.005mV, the third battery cell array 23 is packaged to obtain the battery device 3.

[0168] In one specific implementation, such as Figure 8 As shown, the preparation method further includes the following steps before providing the battery cell 1:

[0169] Provide sample battery cells;

[0170] Establish a table of rework charge states for sample battery cells;

[0171] When the battery cell assembly 2 includes a second type of battery cell 12, the step of reworking the second type of battery cell 12 in the battery cell assembly 2 to obtain a third type of battery cell 13 includes:

[0172] According to the rework state-of-charge correspondence table, the second type of battery cell 12 is reworked to the corresponding state of charge to obtain the third type of battery cell 13.

[0173] In this embodiment of the application, before manufacturing the battery device 3, one or more battery cells 1 can be selected as sample battery cells. By establishing a rework state-of-charge correspondence table for the sample battery cells, the rework state-of-charge corresponding to the second type of battery cell 12 can be directly obtained in a timely manner based on the placement time of the second type of battery cell 12 during the manufacturing process of the battery device 3. This can save calculation time, improve the rework efficiency and quality of the second type of battery cell 12, and thus ensure that the multiple third type of battery cells 13 after rework or the third type of battery cell 13 and the first type of battery cell 11 have high performance consistency. This is beneficial to improving the production efficiency of the battery device 3, improving the stability and reliability of the battery device 3 during operation, and reducing the production cost of the battery device 3.

[0174] In one specific implementation, such as Figure 8 As shown, the steps for establishing the rework state-of-charge correspondence table for sample battery cells include:

[0175] The sample battery cells were left to stand for a second time, which included multiple time sampling points.

[0176] The voltage of each individual battery cell in the sample was measured at various time sampling points to plot a voltage-time curve;

[0177] Calculate the slope of the line connecting each time sampling point, and classify multiple time sampling points to form multiple time periods;

[0178] The rework state-of-charge correspondence table is established by querying the voltage-state-of-charge curve corresponding to the sample battery cells and combining it with the voltage-time curve.

[0179] The second time is t2, and t2 satisfies 7 days ≤ t2 ≤ 180 days.

[0180] In this embodiment, firstly, the sample battery cell is left to stand for a second time, and the voltage of the sample battery cell at each time sampling point during the second time is detected to record the voltage change process of the sample battery cell during the second time and to plot the corresponding voltage-time curve. Secondly, multiple time sampling points are connected to calculate the slope of each connection, and the multiple time sampling points are classified according to the slope to form multiple time periods, with at least two close time sampling points included in the same time period, so as to more significantly reflect the change process of the sample battery cell. Then, combined with the voltage-state-of-charge curve of the sample battery cell, the voltage parameter and the state-of-charge parameter are correlated through the time parameter to establish a rework state-of-charge correspondence table. This allows the staff to directly determine the rework state of the second type of battery cell 12 by placing it for a period of time during the preparation of the battery device 3, which is beneficial to improving the rework efficiency and accuracy of the second type of battery cell 12, avoiding the risk of over-processing or under-processing of the second type of battery cell 12 during the rework process, thereby improving the product quality of the third type of battery cell 13.

[0181] In particular, by reworking, the second type of battery cells 12, which have different storage times and electrochemical states but are similar to each other, can be unified again, laying the foundation for the performance consistency of each battery cell array 2 in the future. This will help improve the utilization rate of the second type of battery cells 12, reduce their scrap rate, and thus reduce the production cost of the battery device 3.

[0182] Meanwhile, the specific resting time for the sample battery cells can be 7 days, 14 days, 21 days, 28 days, 35 days, 42 days, 49 days, 56 days, 63 days, 70 days, 77 days, 84 days, 91 days, 98 days, 105 days, 112 days, 119 days, 126 days, 133 days, 140 days, 147 days, 154 days, 161 days, 168 days, 175 days, or 180 days. By extending the resting time of the sample battery cells, the range of second-type battery cells 12 that can be reworked is expanded, and the conditions are broadened. This helps to reduce the scrap rate of second-type battery cells 12, improve the utilization rate of second-type battery cells 12, thereby extending the storage time of battery cells 1, reducing the rework frequency of battery cells 1, and ultimately reducing the production cost of battery device 3.

[0183] In one specific implementation, such as Figure 6 and Figure 8 As shown, the slope of the line connecting the sampling points at each time point in the second time period is k, and k satisfies 0≤k≤0.05.

[0184] In this embodiment, the slope of each connecting line can significantly reflect the performance change trend of the sample battery cell in the second time period, so as to classify multiple time sampling points in the subsequent process. The slope of the connecting line satisfies 0≤k≤0.05, meaning that the various performance parameters of the sample battery cell are in a stable state. Classifying the time sampling points within this range can obtain more detailed time periods, thereby improving the matching degree between time, voltage, and state of charge. This is beneficial to improving the accuracy of the rework state of charge correspondence table, and thus enables batch processing of the provided second type of battery cell 12 to improve rework efficiency.

[0185] Optionally, the slope of the line connecting the sampling points in the second time interval can be 0, 0.001, 0.003, 0.005, 0.007, 0.009, 0.01, 0.011, 0.013, 0.015, 0.017, 0.019, 0.02, 0.021, 0.023, 0.025, 0.027, 0.029, 0.03, 0.031, 0.033, 0.035, 0.037, 0.039, 0.04, 0.041, 0.043, 0.045, 0.047, 0.049, 0.05, etc.

[0186] In one specific implementation, such as Figure 6 and Figure 8 As shown, there are multiple time periods, including the first time period, the second time period, the third time period, the fourth time period, the fifth time period, and the sixth time period.

[0187] The first time period is t. 21 , and t 21 Satisfying 7 days ≤ t 21 <14 days, the second time period is t 22 , and t 22 Satisfying 14 days ≤ t 22 <21 days, the third time period is t 23 , and t 23 Satisfying 21 days ≤ t 23 <30 days, the fourth time period is t 24 , and t 24 Satisfying 30 days ≤ t 24 <60 days, the fifth time period is t 25 , and t 25 Satisfying 60 days ≤ t 25 <90 days, the sixth time period is t 26 , and t 26 Satisfying 90 days ≤ t 26 ≤180 days.

[0188] In this embodiment, multiple time sampling points of the second time are divided into a first time period, a second time period, a third time period, a fourth time period, a fifth time period, and a sixth time period. Each time period can correspond to the electrochemical stage of the sample battery cell in the second time period, so as to form a targeted rework plan. This is beneficial to improve the accuracy and success rate of rework of the second type of battery cell 12, so as to ensure the quality of rework. This can improve the performance consistency between multiple third type of battery cells 13 or between the third type of battery cell 13 and the first type of battery cell 11, and thus improve the product quality of the battery device 3.

[0189] Optionally, the first time period can be 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, etc.

[0190] Optionally, the second time period can be 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, etc.

[0191] Optionally, the third time period can be 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, etc.

[0192] Optionally, the fourth time period can be 30 days, 32 days, 34 days, 36 days, 38 days, 40 days, 42 days, 44 days, 46 days, 48 ​​days, 50 days, 52 days, 54 days, 56 days, 58 days, etc.

[0193] Optionally, the fifth time period can be 60 days, 62 days, 64 days, 66 days, 68 days, 70 days, 72 days, 74 days, 76 days, 78 days, 80 days, 82 days, 84 days, 86 days, 88 days, etc.

[0194] Optionally, the sixth time period can be 90 days, 95 days, 100 days, 105 days, 110 days, 115 days, 120 days, 125 days, 130 days, 135 days, 140 days, 145 days, 150 days, 155 days, 160 days, 165 days, 170 days, 175 days, 180 days, etc.

[0195] In one specific implementation, such as Figure 6 and Figure 8 As shown, the rework charge states corresponding to each time period include the first rework charge state, the second rework charge state, the third rework charge state, the fourth rework charge state, the fifth rework charge state, and the sixth rework charge state.

[0196] The first rework charge state is SOC1, and SOC1 satisfies 20% < SOC1 ≤ 21%. The second rework charge state is SOC2, and SOC2 satisfies 19.5% < SOC2 ≤ 20%. The third rework charge state is SOC3, and SOC3 satisfies 19.1% < SOC3 ≤ 19.5%. The fourth rework charge state is SOC4, and SOC4 satisfies 18.8% < SOC4 ≤ 19.1%. The fifth rework charge state is SOC5, and SOC5 satisfies 18.6% < SOC5 ≤ 18.8%. The sixth rework charge state is SOC6, and SOC6 satisfies 18.5% ≤ SOC6 ≤ 18.6%.

[0197] In this embodiment, by setting multiple rework states of charge corresponding to multiple time periods, targeted rework can be performed on the second type of battery cells 12 that have been stored for different periods. This ensures that the reworked third type of battery cell 13 has a similar or identical state of charge to the first type of battery cell 11, facilitating precise rework, improving work efficiency, and reducing unnecessary time and energy consumption. Simultaneously, precise rework of each second type of battery cell 12 ensures the performance consistency of the third type of battery cell 13, facilitating subsequent testing and improving the accuracy of test results. Furthermore, the rework-corresponding state of charge ensures that the input absolute lithium quantity matches the most stable capacity of the second type of battery cell 12, avoiding the risk of over-lithiation of the electrodes inside the second type of battery cell 12, thus improving the stability of the reworked third type of battery cell 13.

[0198] Optionally, the first rework charge state can be 20.1%, 20.2%, 20.3%, 20.4%, 20.5%, 20.6%, 20.7%, 20.8%, 20.9%, 21%, etc.

[0199] Optionally, the second rework charge state can be 19.55%, 19.6%, 19.65%, 19.7%, 19.75%, 19.8%, 19.85%, 19.9%, 19.95%, 20%, etc.

[0200] Optionally, the third rework charge state can be 19.15%, 19.2%, 19.25%, 19.3%, 19.35%, 19.4%, 19.45%, 19.5%, etc.

[0201] Optionally, the fourth rework charge state can be 18.85%, 18.9%, 18.95%, 19%, 19.05%, 19.1%, etc.

[0202] Optionally, the fifth rework charge state can be 18.65%, 18.7%, 18.75%, 18.8%, etc.

[0203] Optionally, the sixth rework charge state can be 18.5%, 18.55%, 18.6%, etc.

[0204] Optionally, the state of charge of both the first type of battery cell 11 and the third type of battery cell 13 is 21%.

[0205] Embodiments of this application also provide a battery device, such as... Figure 5 As shown, the battery device 3 is manufactured using any of the above-described preparation methods, and the battery device 3 includes one or more of the following: battery module, battery pack, and energy storage battery.

[0206] In this embodiment, there may be multiple battery cells 1 within the battery device 3. These multiple battery cells 1 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 1 are connected in both series and parallel configurations. Multiple battery cells 1 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 1 is housed within the casing of the battery device 3. Alternatively, the battery device 3 can also consist of multiple battery cells 1 first connected in series, parallel, or in a mixed configuration to form a battery module, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the casing of the battery device 3. The battery device 3 may also include other structures; for example, it may include a busbar component for realizing the electrical connection between the multiple battery cells 1.

[0207] Embodiments of this application also provide an electrical device, such as... Figure 9 As shown, the electrical device 4 includes the battery device 3 as described above, which is used to provide electrical energy.

[0208] In this embodiment, the electrical device 4 can be, but is not limited to, a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, electric car, ship, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft.

[0209] Embodiments of this application also provide an energy storage device, such as... Figure 10 As shown, the energy storage device 5 includes the battery device 3 as described above, which is used to store electrical energy.

[0210] In this embodiment, the energy storage device 5 can be, but is not limited to, an energy storage container, an energy storage cabinet, an energy storage power station, an energy storage battery pack, or a portable energy storage system. The energy storage device 5 employs the battery device 3 described above, enabling long-term energy storage to meet the needs of long-term energy storage applications such as 4-hour or 8-hour storage.

[0211] The above description, based on the embodiments shown in the drawings, details the structure, features, and effects of this application. The above description is only a preferred embodiment of this application, but this application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of this application, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and drawings, should be within the protection scope of this application.

Claims

1. A method for preparing a battery device, characterized in that, The preparation method includes: Provide battery cells; The placement time of the battery cells is detected so that the battery cells include a first type of battery cells and a second type of battery cells; The first type of battery cells and / or the second type of battery cells are stacked together to form a battery cell stack. When the battery cell tray group contains only the first type of battery cell, the battery cell tray group is packaged as the first battery cell tray group to obtain the battery device. When the battery cell array includes the second type of battery cell, the second type of battery cell in the battery cell array is reworked to obtain the third type of battery cell. The third type of battery cell, or the third type of battery cell and the first type of battery cell, are assembled into a tray to form a second battery cell tray group and a third battery cell tray group, respectively. The second battery cell tray group and the third battery cell tray group are then packaged to obtain the battery device. Wherein, the placement time of the first type of battery cell is t. 01 , and t 01 Satisfy t 01 <7 days, the placement time of the second type of battery cell is t 02 , and t 02 Satisfy t 02 ≥7 days, the placement time of the third type of battery cell is t 03 , and t 03 Satisfy t 03 <7 days.

2. The preparation method according to claim 1, characterized in that, The steps of assembling the third type of battery cell, or the third type of battery cell and the first type of battery cell, into a tray to form a second battery cell tray group and the third battery cell tray group respectively, and packaging the second battery cell tray group and the third battery cell tray group respectively to obtain the battery device include: The battery cells in the second battery cell array and / or the third battery cell array are placed synchronously at a first time. Detect the self-discharge rate of each battery cell in the second battery cell array and / or the third battery cell array. Detect the pressure difference between the battery cells in the second battery cell array and / or the battery cell array in the third battery cell array; The second battery cell tray and / or the third battery cell tray are packaged to obtain the battery device; Wherein, the self-discharge rate of each battery cell in the second battery cell array is α2, and α2 satisfies α2≤0.04% / day; the voltage difference between each battery cell in the second battery cell array is β2, and β2 satisfies β2≤0.005mV; the self-discharge rate of each battery cell in the third battery cell array is α3, and α3 satisfies α3≤0.04% / day; the voltage difference between each battery cell in the third battery cell array is β3, and β3 satisfies β3≤0.005mV.

3. The preparation method according to claim 2, characterized in that, The steps of detecting the self-discharge rate of each battery cell in the second battery cell array and / or the third battery cell array include: The first time period includes a first time period detection point and a second time period detection point; The voltage of each battery cell is detected at the first time detection point and the second time detection point; The voltage-state-of-charge curve of the battery cell is queried, and the voltages at the first and second time detection points are converted into the corresponding states of charge. The self-discharge rate of each of the battery cells is calculated. Wherein, the first time detection point is t 11 The second time detection point is t 12 , and t 11 and t 12 Satisfy t 12 >t 11 .

4. The preparation method according to claim 3, characterized in that, The step of detecting the pressure difference between the individual cells in the second battery cell array, or the third battery cell array, includes: The first time point also includes a third time point; The voltage of each of the battery cells is detected at the third time point. The maximum and minimum voltages at the third time detection point are selected for calculation to obtain the voltage difference between each battery cell. The third time detection point is t. 13 , and t 11 t 12 and t 13 Satisfy t 13 >t 11 , t 13 >t 12 The maximum voltage of the battery cell at the third time detection point is β. max The minimum voltage of the battery cell at the third time detection point is β. min , and β max and β min Satisfy β max -β min ≤0.005mv.

5. The preparation method according to claim 4, characterized in that, t 11 It also satisfies 24h≤t 11 ≤72h,t 12 It also satisfies 72h < t 12 ≤120h,t 13 It also satisfies 120h < t 13 ≤168h.

6. The preparation method according to claim 1, characterized in that, The voltage difference between each battery cell in the first battery cell array is β1, and β1 satisfies β1≤0.005mV.

7. The preparation method according to any one of claims 1-6, characterized in that, Prior to providing the battery cell, the preparation method further includes: Provide sample battery cells; Establish a table corresponding to the rework state of charge of the sample battery cells; When the battery cell array includes the second type of battery cell, the step of reworking the second type of battery cell in the battery cell array to obtain the third type of battery cell includes: The second type of battery cell is reworked to the corresponding state of charge according to the rework state of charge correspondence table to obtain the third type of battery cell.

8. The preparation method according to claim 7, characterized in that, The steps for establishing the rework state-of-charge correspondence table for the sample battery cells include: The sample battery cell is left to stand for a second time, the second time including multiple time sampling points; The voltage of the sample battery cell at each of the specified time sampling points is detected to plot a voltage-time curve; Calculate the slope of the line connecting each of the time sampling points, and classify the multiple time sampling points to form multiple time periods; The rework state-of-charge correspondence table is established by querying the voltage-state curve corresponding to the sample battery cell and combining it with the voltage-time curve. The second time is t2, and t2 satisfies 7 days ≤ t2 ≤ 180 days.

9. The preparation method according to claim 8, characterized in that, The slope of the line connecting each time sampling point in the second time period is k, and k satisfies 0≤k≤0.

05.

10. The preparation method according to claim 8, characterized in that, The multiple time periods include a first time period, a second time period, a third time period, a fourth time period, a fifth time period, and a sixth time period; The first time period is t 21 , and t 21 Satisfying 7 days ≤ t 21 <14 days, the second time period is t 22 , and t 22 Satisfying 14 days ≤ t 22 <21 days, the third time period is t 23 , and t 23 Satisfying 21 days ≤ t 23 <30 days, the fourth time period is t 24 , and t 24 Satisfying 30 days ≤ t 24 <60 days, the fifth time period is t 25 , and t 25 Satisfying 60 days ≤ t 25 <90 days, the sixth time period is t 26 , and t 26 Satisfying 90 days ≤ t 26 ≤180 days.

11. The preparation method according to claim 10, characterized in that, The rework charge states corresponding to each of the aforementioned time periods include the first rework charge state, the second rework charge state, the third rework charge state, the fourth rework charge state, the fifth rework charge state, and the sixth rework charge state; The first rework charge state is SOC1, and SOC1 satisfies 20% < SOC1 ≤ 21%; the second rework charge state is SOC2, and SOC2 satisfies 19.5% < SOC2 ≤ 20%; the third rework charge state is SOC3, and SOC3 satisfies 19.1% < SOC3 ≤ 19.5%; the fourth rework charge state is SOC4, and SOC4 satisfies 18.8% < SOC4 ≤ 19.1%; the fifth rework charge state is SOC5, and SOC5 satisfies 18.6% < SOC5 ≤ 18.8%; the sixth rework charge state is SOC6, and SOC6 satisfies 18.5% ≤ SOC6 ≤ 18.6%.

12. A battery device, characterized in that, The battery device is manufactured using the preparation method described in any one of claims 1-11, and the battery device includes one or more of the following: battery module, battery pack, and energy storage battery.

13. An electrical appliance, characterized in that, The electrical device includes the battery device as described in claim 12, the battery device being used to provide electrical energy.

14. An energy storage device, characterized in that, The energy storage device includes the battery device as described in claim 12, the battery device being used to store electrical energy.

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