Battery cell connecting piece and battery module

Abstract

The utility model provides a battery cell connecting piece and a battery module, relates to the technical field of battery structures, and aims to solve the problem of possible non-uniform overcurrent when the connecting piece is connected with a plurality of battery cells. The battery cell connecting piece comprises a first switching part, a second switching part and a connecting part, wherein the first switching part is provided with a first side edge and a second side edge; the pole connecting part is connected with the first side edge and is used for being connected with a pole; the first tab connecting part is connected with the second side edge and is used for being connected with a tab; and along the extension direction of the first side edge, the length of the first switching part is equal to the length of the pole connecting part. According to the invention, the problem of non-uniform overcurrent possibly occurring when a plurality of battery cells are connected in parallel can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery structures, and in particular to a battery cell connecting piece and a battery module. Background Art

[0002] In recent years, with the promotion of new energy and technological advancements, the power battery industry has seen significant growth. Currently, the most widely used power battery is the prismatic power battery, which is mostly composed of a single-cell or dual-cell pack. As the demand for battery capacity gradually increases, the requirements for battery cells are also becoming increasingly higher. In related technologies, increasing battery capacity mainly involves increasing the thickness of the battery cell, or replacing the single-cell pack with a dual-cell pack and increasing the thickness of each cell.

[0003] However, correspondingly, as the thickness of the battery cell increases, some problems will also arise. For example, the increased thickness of the battery cell will make the battery cell itself difficult to process, and the area of ​​the electrode used to conduct current will increase, resulting in a decrease in the electrode yield and difficulty in welding. Therefore, in the related art, a connecting piece structure is proposed. This connecting piece structure can connect multiple core packs in parallel to each other, thereby achieving the effect of increasing battery capacity without increasing the thickness of the battery cell. However, because this connecting piece structure needs to have multiple connecting parts to meet the connection of the connecting piece to the tabs and poles of different battery cells respectively, the connecting piece has unstable current capacity, uneven current flow, and even local current collection when conducting current. Utility Model Content

[0004] The embodiments of the present application provide a battery cell connecting piece and a battery module, which are used to improve the problem of uneven overcurrent that may occur when the connecting piece connects multiple battery cells.

[0005] In a first aspect, an embodiment of the present application provides a battery cell connecting sheet, comprising:

[0006] The first transition portion has a first side edge and a second side edge adjacent to each other;

[0007] a pole connecting portion connected to the first side and used for connecting to the pole;

[0008] a first tab connecting portion connected to the second side and used for connecting to the tab;

[0009] Wherein, along the extension direction of the first side, the length of the first transition portion is equal to the length of the pole connecting portion.

[0010] In some embodiments of the present application, along the extension direction of the first side, the length of the first tab connecting portion is not less than the length of the first transition portion.

[0011] In some embodiments of the present application, along the extension direction of the second side, the length of the pole connecting portion is not less than the length of the first transition portion.

[0012] In some embodiments of the present application, along the extension direction of the second side, when the length of the pole connecting portion is greater than the length of the first transition portion, the pole connecting portion is bent multiple times toward the first transition portion.

[0013] In some embodiments of the present application, the pole connecting portion has a first connecting end and a second connecting end relative to each other, the first connecting end is connected to the first side, the battery cell connecting piece also includes a second adapter portion and a second pole tab connecting portion, the second adapter portion has adjacent third side and fourth side, the third side is connected to the second connecting end, and the fourth side is connected to the second pole tab connecting portion.

[0014] In some embodiments of the present application, the cell connecting piece is axially symmetrical with a midline of the pole connecting portion along the extension direction of the second side as an axis.

[0015] In some embodiments of the present application, a second bending area is defined at a connection between the second pole connection portion and the second transition portion, and the second pole connection portion is configured to bend along the second bending area toward the second transition portion so that the second pole connection portion and the second transition portion are arranged opposite to each other.

[0016] In some embodiments of the present application, the strength of the first bending area is smaller than the strength of the pole connection part and the strength of the first transition part; the strength of the second bending area is smaller than the strength of the pole connection part and the strength of the second transition part.

[0017] In some embodiments of the present application, the flow area calculation formulas of the first tab connection portion and the second tab connection portion are both: A≥(1.5*C*B) / 10; the flow area calculation formulas of the first transition portion and the second transition portion are both: S≥A*F;

[0018] Among them, A represents the flow area of ​​the tab connection; B represents the number of battery packs connected to the tab connection; C represents the capacity of a single battery pack; S represents the flow area of ​​the adapter; F represents the number of the tab connection parts connected to the adapter.

[0019] In a second aspect, an embodiment of the present application further provides a battery module, comprising:

[0020] a plurality of electrode assemblies, wherein the plurality of electrode assemblies are sequentially arranged along an extension direction of the second side;

[0021] a cover plate assembly, covering the electrode assembly;

[0022] The battery cell connecting piece as described in the first aspect is provided between the electrode assembly and the cover assembly and electrically connects the cover assembly to the electrode assembly.

[0023] Beneficial effects of the embodiments of the present application:

[0024] In the embodiments of the present application, the pole connecting portion is connected to the first side edge, and the length of the first transition portion is set to be equal to the length of the pole connecting portion along the extension direction of the first side edge. This ensures that the length of the current path does not change as much as possible when the first transition portion and the pole connecting portion conduct current, that is, the current flow rate is always consistent, thereby achieving the purpose of uniform and stable current flow. Specifically, first, the pole connecting portion is connected to the first side edge of the first transition portion, and the first tab connecting portion is connected to the second side edge, so that the pole connecting portion and the pole connecting portion are connected and the first tab connecting portion and the tab connecting portion do not interfere with each other and current interference; second, the length of the first transition portion in the direction extending along the first side edge is equal to the length of the pole connecting portion in the direction extending along the first side edge. This ensures that the current flow rate is constant when the current is conducted between the first transition portion and the pole connecting portion, thereby improving the current flow uniformity of the cell connecting piece, reducing the phenomenon of current concentration, and helping to improve the performance and efficiency of the battery module. In addition, setting the length of the first transition portion in the direction extending along the first side edge to be equal to the length of the pole connecting portion in the direction extending along the first side edge is also beneficial for more uniform stress distribution when the pole connecting portion and the first transition portion are connected to each other, ensuring a tighter connection between the pole connecting portion and the first transition portion, thereby improving the stability and reliability of the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 is a structural schematic diagram of a battery module provided in an embodiment of the present application;

[0027] Figure 2 yes Figure 1 Schematic diagram of the explosion structure (first person perspective);

[0028] Figure 3 yes Figure 1 Schematic diagram of the explosion structure (second perspective);

[0029] Figure 4 This is a schematic structural diagram of another battery module provided by an embodiment of the present application when the cell connecting piece is not bent;

[0030] Figure 5 This is a schematic structural diagram of a battery cell connecting piece provided in an embodiment of the present application;

[0031] Figure 6 yes Figure 5 Schematic diagram of the flat unfolded structure of the cell connector;

[0032] Figure 7 This is a schematic structural diagram of another battery cell connecting piece provided in an embodiment of the present application;

[0033] Figure 8 yes Figure 7 Schematic diagram of the flat unfolded structure of the cell connector;

[0034] Figure 9 1 is a schematic diagram of a planar unfolded structure of another battery cell connecting sheet provided in an embodiment of the present application;

[0035] Figure 10 This is a schematic structural diagram of another battery cell connecting piece provided in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 1. Electrode assembly; 11. Battery cell; 12. Tab; 121. Welding groove; 2. Cover assembly; 21. Cover body; 22. Post; 3. Cell connector; 31. First adapter; 311. First side; 312. Second side; 32. Post connector; 321. First connection end; 322. Second connection end; 33. First tab connector; 34. First avoidance position; 35. First bending area; 36. Second adapter; 361. Third side; 362. Fourth side; 37. Second tab connector; 38. Second bending area; 39. Second avoidance position; X, length direction; Y, width direction. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; and "inside" and "outside" refer to the outline of the device.

[0039] See Figures 1 to 4 , an embodiment of the present application proposes a battery module, comprising:

[0040] A plurality of electrode assemblies 1, wherein the plurality of electrode assemblies 1 are sequentially arranged along a length direction X;

[0041] A cover plate assembly 2, which is provided on the electrode assembly 1;

[0042] The cell connecting piece 3 is provided between the electrode assembly 1 and the cover assembly 2 and electrically connects the cover assembly 2 to the electrode assembly 1 .

[0043] The battery module is electrically connected to the electrode assembly 1 and the cover assembly 2 through the cell connecting piece 3 by setting a cell connecting piece 3 between the electrode assembly 1 and the cover assembly 2. That is to say, in order to increase the battery capacity, the battery module does not need to adopt the method of thickening the electrode assembly 1, but can adopt the method of increasing the number of electrode assemblies 1 and using the cell connecting piece 3 to realize the connection between multiple electrode assemblies 1 and the cover assembly 2 to increase the capacity of the battery module, thereby avoiding a series of problems caused by the excessive thickness of the electrode assembly 1 as mentioned in the background technology.

[0044] In some embodiments, the electrode assembly 1 includes a battery cell 11 and a tab 12. Each battery cell 11 is provided with at least one tab 12, which is located at the top of the battery cell 11. In this embodiment, each battery cell 11 is provided with two tabs 12, which are spaced apart along the width direction Y of the electrode assembly 1. Of course, each battery cell 11 may also be provided with only one tab 12 or with three or more tabs 12, depending on the actual structure of the battery module and actual needs. The cover plate assembly 2 includes a cover plate body 21 and a pole 22, wherein the cover plate body 21 is covered on the battery cell 11 and covers the pole lug 12, and the pole 22 is arranged on the side of the cover plate body 21 facing the battery cell 11; the battery cell connecting piece 3 is electrically connected to the pole lug 12 and the pole 22 to realize the electrical connection between the pole 22 and the pole lug 12, and because the battery cell connecting piece 3 can play the role of indirect conduction, one battery cell connecting piece 3 can connect multiple electrode assemblies 1 with the cover plate assembly 2, thereby realizing the increase of the capacity of the battery module.

[0045] It should be noted that, in this embodiment, multiple battery cells 11 are provided, and multiple battery cells 11 can be connected through a battery cell connecting piece 3, and the multiple battery cells 11 preferably have the same structure, the same size and the same thickness, which is convenient for calculating the battery capacity of the battery module and for the size design of the battery cell connecting piece 3.

[0046] Furthermore, the tab 12 is provided with a welding groove 121, and the welding groove 121 is open on one side facing the longitudinal direction X. The welding groove 121 extends along the width direction Y. One side of the battery cell connecting piece 3 is disposed within the welding groove 121 and welded to the inner wall of the welding groove 121, thereby achieving electrical conduction between the battery cell connecting piece 3 and the tab 12. Furthermore, along the longitudinal direction X, the tabs 12 on adjacent battery cells 11 are arranged in sequence, and the opening directions of the welding grooves 121 of adjacent tabs 12 are opposite. By utilizing the arrangement of welding grooves 121 with opposite opening directions, adjacent welding grooves 121 can have two situations: one is that the opening directions of two adjacent welding grooves 121 are arranged in opposite directions, and the other is that the opening directions of two adjacent welding grooves 121 are arranged in opposite directions, and the two situations appear staggered along the longitudinal direction X. A fixed space can be defined by two adjacent welding grooves 121 with openings facing each other, so that the portion where the cell connecting piece 3 is connected to the tab 12 can be confined within the fixed space, thereby improving the fixing stability of the cell connecting piece 3 and the stability of the electrical connection.

[0047] See Figures 5 to 9 In some embodiments, the cell connecting piece 3 includes:

[0048] The first connecting portion 31 has a first side 311 and a second side 312 adjacent to each other;

[0049] a pole connecting portion 32 connected to the first side 311 and configured to connect to the pole 22;

[0050] The first tab connecting portion 33 is connected to the second side 312 and is used to connect to the tab 12;

[0051] Wherein, along the extension direction of the first side 311 , the length of the transition portion is equal to the length of the pole connecting portion 32 .

[0052] The technical solution provided in the embodiment of the present application is mainly to connect the pole connection part 32 with the first side 311, and along the extension direction of the first side 311, the length of the first adapter part 31 is set to be equal to the length of the pole connection part 32, so that when the first adapter part 31 and the pole connection part 32 conduct current, it is possible to ensure as much as possible that the length of the overcurrent path does not change, that is, the current flow is always consistent, so as to achieve the purpose of uniform and stable overcurrent. In detail, first, the pole connection part 32 is connected to the first side 311 of the first adapter part 31, and the first pole tab connection part 33 is connected to the second side 312, so that the pole connection part 32 is connected to the pole 22, and the first pole tab connection part 33 is connected to the pole tab 12 without causing interference and current interference; secondly, the length of the first adapter part 31 in the direction extending along the first side 311 is equal to the length of the pole connection part 32 in the direction extending along the first side 311, so that when the current is conducted between the first adapter part 31 and the pole connection part 32, the current flow can be kept constant, thereby improving the overcurrent uniformity of the battery cell connecting piece 3, reducing the current concentration phenomenon, and helping to improve the performance and efficiency of the battery module. In addition, setting the length of the first transition portion 31 in the direction extending along the first side 311 to be equal to the length of the pole connection portion 32 in the direction extending along the first side 311 is also beneficial for more uniform stress distribution when the pole connection portion 32 and the first transition portion 31 are connected to each other, ensuring a tighter connection between the pole connection portion 32 and the first transition portion 31, thereby improving the stability and reliability of the connection.

[0053] It should also be noted that the structure of the battery cell connecting piece 3 in the present application is evenly distributed, which makes the transmission of current in the connection part more stable. The parallel connection of multiple battery cells 11 can disperse the current load and reduce the risk of local current overload. In addition, the connection part adopts an integrally formed connection in this embodiment, and the adapter and the pole connection part 32 adopt the same width design to ensure the stability of the connection as much as possible and effectively avoid overcurrent problems caused by poor connection. Accordingly, because the structure of the battery cell connecting piece 3 can reduce the local concentration of current and reduce the risk of heating in the connection part, the heating problem caused by excessive local current is reduced. In addition, the stability and reliability of the connection part improve the heat transfer efficiency and help reduce the overall heat generation.

[0054] Furthermore, there are multiple first tab connecting portions 33, and the multiple first tab connecting portions 33 are spaced apart along the extension direction of the second side 312, i.e., the length direction X. By providing multiple tab connecting portions on the adapter portion, each tab connecting portion can be connected to at least one tab 12, allowing the battery module to have multiple cells 11, not limited to current single-cell or dual-cell batteries. In other words, to increase battery capacity, the number of cells 11 can be increased instead of increasing the thickness of the cells 11, effectively avoiding a series of problems caused by increasing the thickness of the cells 11, such as difficulty in processing the cells 11, excessive area of ​​the tabs 12, and increased defective rate. Regarding the multiple tab connecting portions being spaced apart in sequence along the length direction X, the spacing is primarily determined by the spacing between adjacent tabs 12, and the number of tab connecting portions is also primarily determined by the number of tabs 12.

[0055] In some embodiments, along the extension direction of the first side 311, i.e., the width direction Y, the length of the first tab connection portion 33 is not less than the length of the first adapter portion 31. This configuration allows the first tab connection portion 33 to adapt to the length of the tab 12 in the width direction Y, thereby preventing the first tab connection portion 33 from being too short, which would increase the difficulty of welding the first tab connection portion 33 to the tab 12 and affect the yield and construction efficiency.

[0056] In some embodiments, the connection between the first pole connection portion 32 and the first adapter portion 31 defines a first bending area 35, and the first pole connection portion 32 is configured to bend along the first bending area 35 toward the first adapter portion 31, so that the first pole connection portion 32 and the first adapter portion 31 are arranged relative to each other. By enabling the pole connection portion 32 and the adapter portion to bend toward each other, the morphological structure of the cell connection piece 3 can be changed through bending, thereby improving the ability of the cell connection piece 3 to adapt to different internal structures of the battery and improving the applicability of the cell connection piece 3. In this embodiment, the pole connection portion 32 and the adapter portion are bent relative to each other, which helps to reduce the space inside the battery occupied by the pole connection portion 32 and the adapter portion, thereby improving the battery integration.

[0057] In some embodiments, along the extension direction of the second side 312, the length of the pole connecting portion 32 is not less than the length of the first transition portion 31, so that the pole connecting portion 32 has sufficient length for bending. For example, when the length of the pole connecting portion 32 is equal to the length of the first transition portion 31, only one bend is required between the pole connecting portion 32 and the first transition portion 31 to achieve the relative arrangement of the pole connecting portion 32 and the first transition portion 31. Figure 10 If the length of the pole connection portion 32 is greater than the length of the first adapter portion 31, especially when the length of the pole connection portion 32 is twice or even more than twice the length of the first adapter portion 31, the pole connection portion 32 can be bent multiple times toward the first adapter portion 31, thereby adjusting the connection distance between the first adapter portion 31 and the pole 22. By adjusting the number of bends, the distance between the surface where the pole connection portion 32 is connected to the pole 22 and the adapter portion can be changed. In other words, the cover plate assembly 2 can be set at different distances from the battery cell 11 according to actual conditions. When the distance is large, the number of bends can be increased to reduce the distance between the pole connection portion 32 and the pole 22, so that the pole connection portion 32 can be connected to the pole 22, thereby expanding the range of different battery module structures and different requirements for internal space that the battery cell connecting piece 3 can adapt to. Furthermore, by setting the number of bends of the pole connecting portion 32 , the distance between the adapter portion and the pole 22 can be changed, so that welding between the pole connecting portion 32 and the pole 22 can be performed within a distance that is more convenient for operation.

[0058] In the above embodiment, the cell connection sheet 3 includes only the first transition portion 31, and the first tab connection portion 33 and the pole connection portion 32 are respectively connected to the two side edges of the first transition portion 31. The following will also illustrate an embodiment in which the cell connection sheet 3, in addition to the first transition portion 31, also includes a second transition portion 36 connected to the pole connection portion 32, and a second tab connection portion 37 connected to the second transition portion 36.

[0059] See Figure 7 and Figure 8 The pole connecting portion 32 has a first connecting end 321 and a second connecting end 322 relative to each other, the first connecting end 321 is connected to the first side 311, and the battery cell connecting piece 3 also includes a second adapter portion 36 and a second pole tab connecting portion 37, the second adapter portion 36 has adjacent third side 361 and fourth side 362, the third side 361 is connected to the second connecting end 322, and the fourth side 362 is connected to the second pole tab connecting portion 37. The structure of the battery cell connecting piece 3 in this embodiment is mainly used to adapt to a situation: the number of battery cells 11 is large, such as more than four and they are all arranged in sequence along the length direction X, and the multiple tabs 12 are also arranged in sequence accordingly, and the number of poles 22 is small, such as only one and the area is small. At this time, the lengths of the first adapter portion 31 and the second adapter portion 36 on both sides of the pole connection portion 32 and the number of tab connections can be selected according to the number of battery cells 11 to adapt to a larger number of battery cells 11. At the same time, the pole connection portion 32 located between the two sub-portions can also be unaffected by the number of tab connections, and a pole connection portion 32 not less than the area of ​​the pole 22 is set.

[0060] Furthermore, a plurality of second tab connecting portions 37 may be provided, and the plurality of second tab connecting portions 37 are spaced apart along the extension direction of the fourth side 362. By matching the number of first tab connecting portions 33, the number of battery cells 11 that can be connected to the battery cell connecting sheet 3 can be greatly increased.

[0061] Furthermore, the cell connection piece 3 is axially symmetrical about the midline of the pole connection portion 32 along the extension direction of the second side 312. That is, the number of first tab connection portions 33 and second tab connection portions 37 is the same, the spacing between adjacent first tab connection portions 33 and adjacent second tab connection portions 37 is equal, and the lengths of the first transition portion 31 and the second transition portion 36 in the longitudinal direction X are also equal. Providing the cell connection piece 3 with an axially symmetrical shape helps improve the uniformity and stability of the cell connection piece 3 during current flow.

[0062] In some embodiments, along the extension direction of the third side 361, the length of the second tab connection portion 37 is not less than the length of the second transition portion 36. This configuration allows the second tab connection portion 37 to adapt to the length of the tab 12 in the width direction Y, thereby preventing the second tab connection portion 37 from being too short, which would increase the difficulty of welding the second tab connection portion 37 to the tab 12 and affect the yield and construction efficiency.

[0063] In some embodiments, the connection between the second pole connection portion 32 and the second adapter portion 36 defines a second bending area 38, and the second pole connection portion 32 is configured to bend along the second bending area 38 toward the second adapter portion 36, so that the second pole connection portion 32 and the second adapter portion 36 are arranged relative to each other. By allowing the pole connection portion 32 and the second adapter portion 36 to bend toward each other, the morphological structure of the cell connection piece 3 can be changed through bending, thereby improving the adaptability of the cell connection piece 3 to different internal structures of the battery and improving the applicability of the cell connection piece 3. In this embodiment, the pole connection portion 32 and the second adapter portion 36 are bent relative to each other, which helps to reduce the space occupied by the pole connection portion 32 and the second adapter portion 36 inside the battery, thereby improving the battery integration.

[0064] Furthermore, the strength of the first area to be bent 35 is less than the strength of the pole connection part 32 and the strength of the first transition part 31; the strength of the second area to be bent 38 is less than the strength of the pole connection part 32 and the strength of the second transition part 36, and is used to improve the bendability between the transition part and the pole connection part 32. The method of reducing the strength of the area to be bent 35 can be selected according to actual conditions. For example, the area to be bent 35 can be provided with holes, that is, a plurality of small holes spaced apart can be provided in the area to be bent 35 to reduce its strength and improve its bendability; the area to be bent 35 can also be thinned; or a partial fold can be preset in the area to be bent 35 to improve its bendability.

[0065] Here, it is necessary to further explain the fact that one side of the cell connecting piece 3 is disposed in the welding groove 121 in the aforementioned embodiment. Specifically, one side of the tab connection portion of the cell connecting piece 3 is disposed in a welding groove 121. In addition, a fixed space can be defined by two adjacent welding grooves 121 with openings arranged in opposite directions, so that the portion of the cell connecting piece 3 connected to the tab 12 can be confined within the fixed space, thereby improving the fixing stability of the cell connecting piece 3 and the stability of the electrical connection. Specifically, the portion of the cell connecting piece 3 connected to the tab 12 refers to a portion of the tab connection portion that can be located within the fixed space and welded to the inner wall of the welding groove 121 to achieve electrical connection.

[0066] In some embodiments, a first avoidance position 34 with an arcuate profile is provided at the connection between the first tab connection portion 33 and the first adapter portion 31; and a second avoidance position 39 with an arcuate profile is provided at the connection between the second tab connection portion 37 and the second adapter portion 36. The first avoidance position 34 and the second avoidance position 39 are both intended to facilitate welding between the tab connection portion and the tab 12; and also to facilitate bending between the pole connection portion 32 and the adapter portion, reducing or even eliminating the impact of bending on the tab connection portion. The use of an arcuate profile to define the avoidance position is primarily intended to smooth the connection between the tab connection portion and the adapter portion, prevent greater wear on the cell connector 3 during operation, and reduce the chance of injury from the telecommunications connector. Furthermore, the arcuate connection also, to a certain extent, has a transitional and dispersing effect on the stress generated by bending.

[0067] See Figure 2 and Figure 3 In some embodiments, the surface area of ​​the pole connection portion 32 facing the pole 22 is not less than the surface area of ​​the pole 22 facing the pole connection portion 32, so as to ensure that the pole connection portion 32 can fully contact and connect with the pole 22 to play a stable current guiding role.

[0068] In some embodiments, the flow area of ​​the tab connection portion is calculated as: A ≥ (1.5 * C * B) / 10; the flow area of ​​the transition portion is calculated as: S ≥ A * F. That is, the flow area of ​​the first tab connection portion 33 and the second tab connection portion 37 is calculated as: A ≥ (1.5 * C * B) / 10; and the flow area of ​​the first transition portion 31 and the second transition portion 36 is calculated as: S ≥ A * F.

[0069] Among them, A represents the flow area of ​​the tab connection part; B represents the number of battery cell 11 packs connected to the tab connection part; C represents the capacity of a single battery cell 11 pack; S represents the flow area of ​​the adapter part; F represents the number of the tab connection parts connected to the adapter part.

[0070] The above calculation formula design means that the flow area of ​​the tab connection should be proportional to the capacity and number of battery cell packs 11. When the capacity or number of battery cell packs 11 increases, the flow area of ​​the tab connection should also increase accordingly to ensure that the battery module can safely handle higher currents. The flow area of ​​the adapter should be at least equal to the sum of the flow areas of all connected tab connections. This formula ensures that the adapter has sufficient flow capacity to handle the current that all connected tab connections may withstand.

[0071] To facilitate understanding of the formula, a simple example is provided: assuming that in this embodiment, the capacity of a single battery cell 11 pack is C = 700Ah, the number of battery cell 11 packs connected to the tab connection portion is B = 4, and the number of tab connection portions connected to the adapter portion is F = 2. The calculation is as follows:

[0072] The flow area of ​​the tab connection is A≥(1.5*700*4) / 10=420mm2;

[0073] The flow area of ​​the transition part is S≥420*2=840mm2.

[0074] Furthermore, in this embodiment, along the width direction Y, the width of the cell connection piece 3 ranges from 95 to 500 mm, and the height ranges from 50 to 200 mm. Both the width and height ranges herein refer to the size ranges of the cell connection piece 3 after it has been bent and formed. Specifically, the width range is the sum of the width of the transition portion and the length of the tab connection portion in the width direction Y; the height range is the distance between the surface of the transition portion facing away from the pole connection portion 32 and the surface of the pole connection portion 32 farthest from the transition portion facing away from the transition portion.

[0075] Furthermore, along the extension direction of the first side edge 311, the length of the first transition portion 31 ranges from 30 mm to 250 mm, and the length of the first tab connection portion 33 ranges from 65 mm to 470 mm. By limiting the length range of the first transition portion 31 and the first tab connection portion 33 along the extension direction of the first side edge 311, the first transition portion 31 can meet the current transfer function and stabilize the center of gravity of the battery cell 11 connection piece while minimizing the required consumables and molding volume of the battery cell 11 connection piece. Generally speaking, because the first tab connection portion 33 connects to the tab 12 and the first transition portion 31 is generally suspended, the shorter the length of the first transition portion 31 along the extension direction of the first side edge 311, the more stable the fixation of the battery cell 11 connection piece. Therefore, in this embodiment, the length of the first transition portion 31 along the extension direction of the first side plate is preferably 30 mm, and the length of the first tab connection portion 33 is selected based on the length of the tab 12. In this embodiment, the length of the first tab connection portion 33 is 200 mm. Along the extension direction of the first side edge 311, the length of the connection portion of the pole 22 ranges from 30 mm to 250 mm. Preferably, the length of the connection portion of the pole 22 along the extension direction of the first side plate is 30 mm. This ensures that the length of the connection portion of the pole 22 and the first transition portion 31 along the extension direction of the first side plate are equal, thereby improving the flow uniformity of the connecting piece of the battery cell 11. Otherwise, along the extension direction of the second side edge 312, the length of the connection portion of the pole 22 and the length of the first transition portion 31 are not limited. The length of the first transition portion 31 is primarily determined by the number and thickness of the battery cells 11 arranged along the extension direction of the second side edge 312. Accordingly, the length of the connection portion of the pole 22 only needs to be greater than or equal to the length of the first transition portion 31.

[0076] In any of the above embodiments, when the pole connecting portion 32 and the adapter portion are disposed relative to each other, the angle between the plane in which the pole connecting portion 32 lies and the plane in which the adapter portion lies is no greater than 20°. In other words, after the pole connecting portion 32 is bent and formed, the angle between the plane in which it lies and the plane in which the adapter portion lies is no greater than 20°, which helps to reduce the height space occupied by the pole connecting portion 32 within the battery module, thereby making the internal structure of the battery module more compact.

[0077] It should be noted that the length direction X mentioned in any embodiment of the present application refers to the extension direction of the second side 312 or the fourth side 362, and the width direction Y refers to the extension direction of the third side panel or the first side 311.

[0078] It should also be noted that the battery module in this application can be used as a power battery for new energy vehicles, new energy operating machinery, etc.

[0079] The present invention is described in detail with reference to the examples. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery cell connecting piece, characterized in that: include: The first transition portion has a first side edge and a second side edge adjacent to each other; a pole connecting portion connected to the first side and used for connecting to the pole; a first tab connecting portion connected to the second side and used for connecting to the tab; Wherein, along the extension direction of the first side, the length of the first transition portion is equal to the length of the pole connecting portion; Along the extension direction of the second side, the length of the pole connecting portion is not less than the length of the first transition portion; Along the extension direction of the second side, when the length of the pole connecting portion is greater than the length of the first transition portion, the pole connecting portion is bent multiple times toward the first transition portion.

2. The battery cell connecting sheet according to claim 1, characterized in that: Along the extension direction of the first side, the length of the first tab connecting portion is not less than the length of the first transition portion.

3. The battery core connecting sheet according to claim 1 or 2, characterized in that: The pole connecting portion has a first connecting end and a second connecting end relative to each other, the first connecting end is connected to the first side, the battery cell connecting piece also includes a second adapter portion and a second pole tab connecting portion, the second adapter portion has adjacent third side and fourth side, the third side is connected to the second connecting end, and the fourth side is connected to the second pole tab connecting portion.

4. The battery cell connecting piece according to claim 3, characterized in that: The cell connecting pieces are axially symmetrical with respect to a midline of the pole connecting portion along the extension direction of the second side as an axis.

5. The battery cell connecting piece according to claim 3, characterized in that: A second bending area is defined at a connection between the pole connection portion and the second transition portion. The pole connection portion is configured to bend along the second bending area toward the second transition portion so that the pole connection portion and the second transition portion are arranged opposite to each other.

6. The battery cell connecting sheet according to claim 5, characterized in that: The strength of the second to-be-bent area is smaller than the strength of the pole connecting portion and the strength of the second transition portion.

7. The battery cell connecting sheet according to claim 3, characterized in that: The flow area calculation formulas of the first tab connection portion and the second tab connection portion are both: A≥(1.5*C*B) / 10; the flow area calculation formulas of the first transition portion and the second transition portion are both: S≥A*F; Among them, A represents the flow area of ​​the tab connection; B represents the number of battery packs connected to the tab connection; C represents the capacity of a single battery pack; S represents the flow area of ​​the adapter; F represents the number of the tab connection parts connected to the adapter.

8. A battery module, characterized in that: include: a plurality of electrode assemblies, wherein the plurality of electrode assemblies are sequentially arranged along an extension direction of the second side; a cover plate assembly, covering the electrode assembly; The battery cell connecting piece according to any one of claims 1 to 7 is arranged between the electrode assembly and the cover assembly and electrically connects the cover assembly to the electrode assembly.

Images