Connecting piece assembly, battery assembly and assembling method thereof

Abstract

The invention provides a connecting piece assembly, a battery assembly and an assembly method thereof, the connecting piece assembly is suitable for electrically connecting and fixing tabs of a plurality of pole groups, the connecting piece assembly comprises two connecting pieces, each connecting piece comprises a plurality of connecting parts along a first direction, the plurality of connecting parts comprise a first connecting part, and a second connecting part comprises a second connecting part; the upper edge and the lower edge extend in the first direction and are opposite to each other in the second direction perpendicular to the first direction, the multiple connecting parts are distributed in a step mode in the first direction, and the upper edge and the lower edge are arranged in the direction away from the first connecting part. The distances between the upper edges of the other connecting parts and the upper edge of the first connecting part in the second direction are increased, and the distances between the lower edges of the other connecting parts and the lower edge of the first connecting part in the second direction are increased; and the plurality of connecting parts are respectively provided with a connecting area at the positions close to the corresponding upper edges and lower edges, and are suitable for being electrically connected with the tabs.

Description

Technical Field

[0001] The present invention mainly relates to the field of batteries, and in particular to a connecting piece assembly, a battery assembly and an assembly method thereof. Background Art

[0002] At present, it has become an important trend to increase the capacity of single cells in the battery field. With the continuous increase in the size of single cells, the thickness of cells is also increasing. The increase in the thickness of cells leads to an increase in the thickness of the electrode group inside the cell. If a bipolar group solution is adopted, the excessive thickness of the single electrode group will bring a series of process challenges, such as high difficulty in hot pressing. Therefore, it has become a mainstream trend to use quadrupole groups or more electrode group solutions for large cells to solve these process problems. Taking the quadrupole group as an example, the prior art usually uses a rectangular or U-shaped connecting piece. First, the four electrode groups are assembled in pairs, and then the pole ears of each two electrode groups are overlapped and welded together to the corresponding position of the connecting piece, and finally folded. However, this will cause the pole ears to be folded multiple times to form an S-shaped bend, and there is a risk of short circuit caused by the inverted insertion of the pole ears into the pole group. In addition, in this case, in order to ensure folding, the pole ears usually have a high height, and there is a risk of wrinkling or folding the pole ears in the coating, rolling and winding processes. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a connecting piece assembly, a battery assembly and an assembly method thereof which can reduce the height of the tab, reduce the risk of wrinkles and folding and make the tab bend into a C-shape.

[0004] In order to solve the above technical problems, the present invention provides a connecting plate assembly suitable for electrically connecting and fixing the pole ears of multiple pole groups, the connecting plate assembly comprising two connecting plates, each of the connecting plates comprising a plurality of connecting parts connected in sequence along a first direction, the plurality of connecting parts comprising a first connecting part, the plurality of connecting parts having an upper edge and a lower edge extending along the first direction and opposite to each other in a second direction perpendicular to the first direction, wherein: the plurality of connecting parts are distributed in a stepped manner along the first direction, and in a direction away from the first connecting part, the distance between the upper edges of the plurality of connecting parts and the central axis of the connecting plate extending along the first direction in the second direction increases, and the distance between the lower edges of the plurality of connecting parts and the central axis in the second direction increases; the plurality of connecting parts respectively have a connecting area at a position close to the corresponding upper edge and the lower edge, which is suitable for electrically connecting to the pole ears.

[0005] In an embodiment of the present invention, the connecting piece is symmetrical about a central axis along the first direction.

[0006] In an embodiment of the present invention, the connecting piece further includes a fixing portion connected to the connecting portion, and the fixing portion is suitable for being electrically connected to the cover plate.

[0007] In an embodiment of the present invention, the fixing portion is located on a side of the first connecting portion away from the other connecting portions in the first direction.

[0008] In one embodiment of the present invention, there is a first distance between the upper edge and the lower edge of the first connecting portion in the second direction, and the first distance is less than or equal to a first threshold value, and the first threshold value is twice the thickness of the pole group.

[0009] In one embodiment of the present invention, there is a second distance in the second direction between the upper edges corresponding to two adjacent connecting parts, and there is a third distance in the second direction between the lower edges corresponding to two adjacent connecting parts. The second distance and the third distance are less than or equal to the second threshold and greater than the third threshold. The second threshold is the thickness of the pole group, and the third threshold is 0.5 times the thickness of the pole group.

[0010] The present invention also provides a battery assembly, comprising a cover plate, the inner side of which has a positive electrode connecting portion and a negative electrode connecting portion; a pole group assembly, comprising a plurality of pole groups adjacent to each other in sequence along a second direction, and each of the pole groups is provided with a positive electrode ear and a negative electrode ear; a connecting piece assembly, comprising two connecting pieces, each of which comprises a plurality of connecting portions connected in sequence along a first direction, the plurality of connecting portions comprising a first connecting portion, the plurality of connecting portions having an upper edge and a lower edge extending along the first direction and opposite to each other in a second direction perpendicular to the first direction, the plurality of connecting portions being distributed in a stepped manner along the first direction, and in a direction away from the first connecting portion, the upper edges of the plurality of connecting portions and the The distance between the central axes of the connecting sheets extending along the first direction in the second direction increases, and the distance between the lower edges of the multiple connecting parts and the central axis in the second direction increases, and the multiple connecting parts each have a connecting area at a position close to the corresponding upper edge and the lower edge; the two connecting sheets include a positive connecting sheet and a negative connecting sheet, the positive connecting section and the negative connecting section are respectively suitable for being electrically connected to the positive connecting sheet and the negative connecting sheet, the multiple connecting areas of the positive connecting sheet are respectively suitable for being electrically connected to the positive ears of the multiple electrode groups, and the multiple connecting areas of the negative connecting sheet are respectively suitable for being electrically connected to the negative ears of the multiple electrode groups.

[0011] In one embodiment of the present invention, when the connecting sheet further includes a fixing portion located on a side of the first connecting portion away from the other connecting portions, the positive connecting portion and the negative connecting portion are respectively suitable for being electrically connected to the fixing portions of the positive connecting sheet and the negative connecting sheet.

[0012] In one embodiment of the present invention, the pole group assembly includes a first outer pole group, a first inner pole group, a second inner pole group and a second outer pole group which are adjacent to each other in sequence along the second direction; each connecting plate of the connecting plate assembly includes a first connecting portion and a second connecting portion along the first direction, the first connecting portion has a connecting area at a position close to its corresponding upper edge and lower edge, respectively, and the second connecting portion has a connecting area at a position close to its corresponding upper edge and lower edge, respectively.

[0013] In one embodiment of the present invention, the positive electrode ears / negative electrode ears of the first inner pole group and the second inner pole group are opposite in the second direction; the positive electrode ears / negative electrode ears of the first outer pole group and the second outer pole group are opposite in the second direction; and the positive electrode ears / negative electrode ears of the first inner pole group and the first outer pole group are staggered in the second direction.

[0014] In one embodiment of the present invention, the positive electrode ear / negative electrode ear of the first inner electrode group and the second inner electrode group are respectively suitable for being electrically connected to the connection area of ​​the first connection part of the positive electrode connecting sheet / negative electrode connecting sheet; the positive electrode ear / negative electrode ear of the first outer electrode group and the second outer electrode group are respectively suitable for being electrically connected to the connection area of ​​the second connection part of the positive electrode connecting sheet / negative electrode connecting sheet.

[0015] The present invention also provides an assembly method, which is suitable for assembling a battery assembly as in any of the previous embodiments, and the assembly method comprises the following steps: a. welding the positive / negative ears of the two electrode groups to the connection areas of the first connection parts of the positive / negative electrode connecting sheets respectively; b. welding the positive connection part and the negative connection part of the cover plate to the positive connection sheet and the negative connection sheet respectively; c. folding the positive ears and the negative ears of the two electrode groups welded in step a so that the two electrode groups are bonded to each other along the second direction; d. welding the positive ears / negative ears of the other two electrode groups to the connection areas of the positive / negative electrode connecting sheets which are closest to the first connection part and have a remaining connection part at this time; e. folding the positive ears and the negative ears of the two electrode groups welded in step d so that the two electrode groups are bonded to the adjacent electrode groups respectively along the second direction; f. repeating steps de until all electrode groups are installed, and at this time all electrode groups are bonded in sequence in the second direction.

[0016] In one embodiment of the present invention, when assembling a battery assembly having four electrode groups, the assembly method includes the following steps: welding the positive electrode ear / negative electrode ear of the first inner electrode group and the second inner electrode group to the connection area of ​​the first connection part of the positive electrode connecting sheet / negative electrode connecting sheet, respectively; welding the positive electrode connecting part and the negative electrode connecting part of the cover plate to the positive electrode connecting sheet and the negative electrode connecting sheet, respectively; folding the positive electrode ear and the negative electrode ear of the first inner electrode group and the second inner electrode group so that the first inner electrode group and the second inner electrode group are mutually attached to each other along the second direction; welding the positive electrode ear / negative electrode ear of the first outer electrode group and the second outer electrode group to the connection area of ​​the second connection part of the positive electrode connecting sheet / negative electrode connecting sheet, respectively; and folding the positive electrode ear and the negative electrode ear of the first outer electrode group and the second outer electrode group so that the first outer electrode group and the first inner electrode group, the second inner electrode group and the second outer electrode group are mutually attached to each other along the second direction.

[0017] Compared with the prior art, in the connecting plate assembly, battery assembly and assembly method thereof provided by the present invention, the pole ears of each pole group are individually welded to the connecting plate assembly. Taking the quadrupole battery cell as an example, the connecting plate is in a "T" shape, and the pole ears of the first inner pole group and the second inner pole group of the four pole groups are welded to the two connection areas of the narrower first connection part of the connecting plate, and the first outer pole group and the second outer pole group are welded to the two connection areas of the wider second connection part of the connecting plate, which can reduce the height of the pole ears. At the same time, the final pole ears only need to be bent once, and the bending shape is "C" shaped, which reduces the risk of wrinkles and folding, and has a low risk of short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the present application, and they are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present invention. In the accompanying drawings: Figure 1 It is a top view of a connecting piece of the present application.

[0019] Figure 2 It is a side view of a battery assembly of the present application.

[0020] Figure 3 It is a front view of a battery assembly of the present application.

[0021] Figure 4 It is a flow chart of an assembly method of the present application.

[0022] Figure 5 It is a flow chart of another assembly method of the present application.

[0023] Figure 6-14 This application adopts Figure 5 Assembly method: Figure 2-3 Schematic diagram of the battery assembly process.

[0024] Fig.15 It is a top view of another connecting piece of the present application.

[0025] Fig.16 It is a side view of another battery assembly of the present application.

[0026] Fig.17 It is a front view of another battery assembly of the present application.

[0027] Figure 18-20 This application adopts Figure 4 Assembly method: Figure 16-17 Schematic diagram of the battery assembly process.

[0028] Figure 1-20 The reference numerals are described as follows: Connecting pieces 10, 10'; connecting portion 100; first connecting portions 110, 110'; second connecting portions 120, 120'; first direction AA'; second direction BB'; upper edges L1, L3, L5; center axis O; lower edges L2, L4, L6; connecting areas T1, T2, T3, T4, T5, T6; positive connecting piece 10a; negative connecting piece 10b; fixing portion 101; first distance H1; second distance H2; third distance H3; battery assembly 20, 20'; cover plate 30; pole group assembly 40, 40'; positive electrode connection portion 30a; negative electrode connection portion 30b; first outer pole group 41, 41'; first inner pole group 42, 42'; second inner pole group 43, 43'; second outer pole group 44, 44'; positive pole ears 41a, 42a, 43a, 44a; negative pole ears 41b, 42b, 43b, 44b; third connection portion 130'; third pole group 45, 46. DETAILED DESCRIPTION

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0030] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0031] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0032] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0033] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0034] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0035] It should be understood that when a component is referred to as being "on another component," "connected to another component," "coupled to another component," or "contacting another component," it may be directly on, connected to, coupled to, or contacting the other component, or there may be intervening components. In contrast, when a component is referred to as being "directly on another component," "directly connected to," "directly coupled to," or "directly contacting" another component, there are no intervening components. Similarly, when a first component is referred to as being "electrically in contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between conductive components.

[0036] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0037] Figure 1 1 is a top view of a connecting sheet 10 of the present application. Figure 1 As shown, the present invention provides a connecting piece assembly suitable for electrically connecting and fixing the pole ears of multiple pole groups. The connecting piece assembly includes two Figure 1 The connecting piece 10 shown in the preferred embodiment is "T"-shaped and includes a plurality of connecting parts 100 connected in sequence along a first direction AA'. In this embodiment, the connecting part 100 includes a first connecting part 110 and a second connecting part 120, and the first connecting part 110 and the second connecting part 120 have an upper edge and a lower edge extending along the first direction AA', and the corresponding upper edge and lower edge of each connecting part 100 are opposite in a second direction BB' perpendicular to the first direction AA'.

[0038] Specifically, refer to Figure 1As shown, the multiple connecting parts 100 are distributed in a stepped manner in the first direction AA', and in the direction away from the first connecting part 110, the distance between the upper edge of the connecting part 100 (in this embodiment, the upper edge L1 of the first connecting part 110 and the upper edge L3 of the second connecting part 120) and the central axis O on the second edge BB' increases, and the distance between the lower edges of the remaining connecting parts (in this embodiment, the lower edge L2 of the first connecting part 110 and the lower edge L4 of the second connecting part 120) and the central axis O on the second edge BB' increases. That is, in the direction away from the first connecting part 110, the distance between the upper edge and the lower edge of the connecting part 100 in the second direction BB' gradually increases (for details, please refer to Fig.15 ).

[0039] Furthermore, each of the plurality of connecting portions 100 has a connecting area near the corresponding upper edge and lower edge, which is suitable for electrically connecting to the tabs of the electrode group. Figure 1 Taking the illustrated embodiment as an example, the first connection portion 110 has two connection areas near the upper edge L1 and the lower edge L2, which are named as connection area T1 and connection area T2 for easy distinction, and are suitable for electrical connection with the pole ears of the two pole groups. The second connection portion 120 also has two connection areas near the upper edge L3 and the lower edge L4, which are named as connection area T3 and connection area T4 for easy distinction, and are suitable for electrical connection with the pole ears of the other two pole groups.

[0040] The connection areas T1, T2, T3, and T4 are respectively suitable for being electrically connected to the positive electrodes of the four electrode groups or the negative electrodes of the four electrode groups, depending on whether the connection sheet 10 is a positive electrode connection sheet 10a or a negative electrode connection sheet 10b (see Figure 2 In this embodiment, the connection areas T3 and T4 of the second connection portion 120 are respectively located outside the connection areas T1 and T2 in the second direction BB', that is, in the second direction BB', the connection area T3 is located between the upper edge L1 of the first connection portion 110 and the upper edge L3 of the second connection portion 120, and the connection area T4 is located between the lower edge L2 of the first connection portion 110 and the lower edge L4 of the second connection portion 120.

[0041] Preferably, in this embodiment, the connecting piece 10 may be symmetrical about the central axis O along the first direction AA′.

[0042] In such Figure 1 In the illustrated embodiment, the connecting sheet 10 further includes a side of the first connecting portion 110 that is away from the remaining connecting portions 100 along the first direction AA′ (eg Figure 1 The fixing portion 101 is suitable for being electrically connected to the cover plate 30, and the specific connection method will be introduced in the content about the battery assembly later.

[0043] In a preferred embodiment of the present invention, there is a first distance H1 between the upper edge L1 and the lower edge L2 of the first connection portion 110 in the second direction BB', and the first distance H1 is less than or equal to the first threshold value, and the first threshold value is twice the thickness of the electrode group. This setting can make the electrode groups connected to the connection area T1 and the connection area T2 completely cover the first connection portion 110 when they are attached to each other after folding, so as to avoid problems such as miswelding in subsequent welding of the electrode groups.

[0044] In the present invention, Figure 1 In the preferred embodiment shown, there is a second distance H2 between the upper edges (i.e., L1, L3) corresponding to two adjacent connecting parts 100 (i.e., the first connecting part 110 and the second connecting part 120) in the second direction BB', and there is a third distance H3 between the lower edges (i.e., L2, L4) corresponding to two adjacent connecting parts (i.e., the first connecting part 110 and the second connecting part 120) in the second direction BB', and the second distance H2 and the third distance H3 are less than or equal to the second threshold value and greater than the third threshold value, the second threshold value is the thickness of the pole group, and the third threshold value is 0.5 times the thickness of the pole group. It can be understood that the second distance H2 and the third distance H3 are greater than the third threshold value to ensure that after the pole groups connected to the connection area T1 and the connection area T2 are folded, the connection area T3 and the connection area T4 still have enough parts to be exposed for subsequent welding. The second distance H2 and the third distance H3 are less than or equal to the second threshold value so that after the four pole groups are folded, they completely cover the part between the upper edge (i.e., L1, L3) and the lower edge (i.e., L2, L4) of the second connection part 120 of the connecting sheet 10 when they are fitted. Further, when there are more connection parts 100 in the connecting sheet 10, the distance relationship between the upper edge (i.e., L1, L3) and the lower edge (i.e., L2, L4) of two adjacent connection parts 100 in the second direction BB' meets the above conditions, thereby ensuring the accuracy of welding.

[0045] Figure 2 is a side view of a battery assembly 20 of the present application, Figure 3 2 is a front view of a battery assembly 20 of the present application. Figure 1-3 As shown, the present invention further provides a battery assembly 20, including a cover plate 30, an electrode assembly 40 and a connecting piece assembly provided in any embodiment of the present application. The specific structure of the connecting piece assembly can refer to the above description, and no further details are given here. Among them, the number of electrode groups in the electrode assembly 40 is the same as the number of connecting parts 100 of the connecting piece 10. Among them, the connecting piece assembly includes two connecting pieces 10, namely a positive electrode connecting piece 10a and a negative electrode connecting piece 10b, and their specific structures are as shown in FIG. Figure 1 As shown, there is no other difference except the polarity.

[0046] The inner side of the cover plate 30 has a positive electrode connection portion 30a and a negative electrode connection portion 30b, and the positive electrode connection portion 30a and the negative electrode connection portion 30b are respectively suitable for being electrically connected to the positive electrode connection sheet 10a and the negative electrode connection sheet 10b. Figure 1-3 In the preferred embodiment shown, the positive electrode connecting portion 30a and the negative electrode connecting portion 30b are also suitable for being electrically connected to the fixing portions 101 of the positive electrode connecting sheet 10a and the negative electrode connecting sheet 10b, respectively.

[0047] In such Figure 1-3 In the illustrated embodiment, the electrode assembly 40 includes four electrode groups that are adjacent to each other in sequence along the second direction BB': a first outer electrode group 41, a first inner electrode group 42, a second inner electrode group 43, and a second outer electrode group 44. The first outer electrode group 41 is provided with a positive electrode ear 41a and a negative electrode ear 41b, the first inner electrode group 42 is provided with a positive electrode ear 42a and a negative electrode ear 42b, the second inner electrode group 43 is provided with a positive electrode ear 43a and a negative electrode ear 43b, and the second outer electrode group 44 is provided with a positive electrode ear 44a and a negative electrode ear 44b. The positive electrode ears 41a, 42a, 43a, and 44a are suitable for being electrically connected to the positive electrode connecting sheet 10a, and the negative electrode ears 41b, 42b, 43b, and 44b are suitable for being electrically connected to the negative electrode connecting sheet 10b.

[0048] Specifically, the connection area T1, the connection area T2, the connection area T3, and the connection area T4 of the positive electrode connecting piece 10a in this embodiment are respectively suitable for electrically connecting to the positive electrode ears 41a, 42a, 43a, and 44a of the four electrode groups 41, 42, 43, and 44, and the connection area T1, the connection area T2, the connection area T3, and the connection area T4 of the negative electrode connecting piece 10b are respectively suitable for electrically connecting to the negative electrode ears 41b, 42b, 43b, and 44b of the four electrode groups 41, 42, 43, and 44. It should be noted that there is no specific order or corresponding relationship for the above connections. Please refer to the introduction of the assembly method below for details.

[0049] It can be understood that, since the connection area T1 and the connection area T2 in the connection sheet 10 are located in the first connection part 110 and are opposite to each other in the second direction BB', the third connection area T3 and the fourth connection area T4 are located in the second connection part 120 and are opposite to each other in the second direction BB', and the first connection area T1 and the third connection area T3 are staggered in the second direction BB', in order to ensure that the four pole groups are completely aligned and attached after folding, their positive and negative pole ears must also be adaptively arranged. Specifically, the positive pole ears 42a and 43a (or negative pole ears 42b and 43b) of the first inner pole group 42 and the second inner pole group 43 are opposite to each other in the second direction BB'; the positive pole ears 41a and 44a (or negative pole ears 41b and 44b) of the first outer pole group 41 and the second outer pole group 44 are opposite to each other in the second direction BB'; and the positive pole ears 42a and 41a (or negative pole ears 42b and 41b) of the first inner pole group 42 and the first outer pole group 41 are staggered in the second direction BB'.

[0050] In such Figure 2-3 In the illustrated embodiment, the positive pole ears 42a, 43a (or the negative pole ears 42b, 43b) of the first inner pole group 42 and the second inner pole group 43 are respectively suitable for being electrically connected to the connection area T1 and the connection area T2 of the positive electrode connecting sheet 10a (or the negative electrode connecting sheet 10b); the positive pole ears 41a, 44a (or the negative pole ears 41b, 44b) of the first outer pole group 41 and the second outer pole group 44 are respectively suitable for being electrically connected to the connection area T3 and the connection area T4 of the positive electrode connecting sheet 10a (or the negative electrode connecting sheet 10b).

[0051] It should be noted that the first inner pole group 42 and the second inner pole group 43 are located on the inner side of the four pole groups, and the welding handle folding will be performed first. Therefore, it is necessary to set an electrical connection with the connection area T1 and the connection area T2 of the connecting piece 10 to ensure that the first outer pole group 41 and the second outer pole group 44 can continue to be welded and folded after folding. However, the corresponding relationship between the first inner pole group 42, the second inner pole group 43 and the connection area T1, the connection area T2, and the corresponding relationship between the first outer pole group 41 and the second outer pole group 44 and the connection area T3, the connection area T4, are not specifically limited in this application.

[0052] Figure 4 is a flow chart of an assembly method of the present application. Figure 4 As shown, the present invention also provides an assembly method 50 suitable for assembling a battery assembly, and the assembly method 50 comprises the following steps: S51: welding the positive electrode ears / negative electrode ears of the two electrode groups to the connection areas of the first connection parts of the positive electrode connecting sheet / negative electrode connecting sheet respectively; S52: welding the positive electrode connection part and the negative electrode connection part of the cover plate to the positive electrode connection sheet and the negative electrode connection sheet respectively; S53: folding the positive electrode ears and the negative electrode ears of the two electrode groups welded in step S51, so that the two electrode groups are attached to each other along the second direction; S54: welding the positive electrode ears / negative electrode ears of the other two electrode groups to the connection areas of the positive electrode connecting piece / negative electrode connecting piece which are closest to the first connection part and the remaining connection part; S55: folding the positive electrode ears and the negative electrode ears of the two electrode groups welded in step S54, so that the two electrode groups are respectively attached to the adjacent electrode groups along the second direction; S56: Repeat steps S54-S55 until all pole groups are installed.

[0053] Specifically, when assembling Figure 2-3 When the battery assembly 20 has four electrode groups as shown, the assembly method 50 is preferably as follows Figure 5 Assembly method 60 shown: S61: Welding the positive electrode tabs / negative electrode tabs of the first inner electrode group and the second inner electrode group to the first connection area and the second connection area of ​​the positive electrode connecting sheet / negative electrode connecting sheet, respectively.

[0054] S62: Welding the positive electrode connection part and the negative electrode connection part of the cover plate to the positive electrode connection sheet and the negative electrode connection sheet respectively.

[0055] S63: folding the positive electrode ears and the negative electrode ears of the first inner electrode group and the second inner electrode group so that the first inner electrode group and the second inner electrode group are attached to each other along the second direction.

[0056] S64: Welding the positive electrode tabs / negative electrode tabs of the first external electrode group and the second external electrode group to the third connection area and the fourth connection area of ​​the positive electrode connecting sheet / negative electrode connecting sheet, respectively.

[0057] S65: Folding the positive electrode ears and the negative electrode ears of the first outer electrode group and the second outer electrode group, so that the first outer electrode group and the first inner electrode group, the second inner electrode group and the second outer electrode group are mutually attached along the second direction.

[0058] Figure 6-8 This application adopts Figure 5 Assembly method 60 Assembly as Figure 2-3 A schematic diagram of the process of the battery assembly 20. Figure 1-3 , 5-14 The assembly method 60 is described in detail as follows: First, in step S51, the positive electrode connecting sheet 10a and the negative electrode connecting sheet 10b need to be aligned and placed along the first direction AA', so that the ends of the two with the fixing portion 101 are opposite, and the distance between the connection area T1 of the positive electrode connecting sheet 10a and the negative electrode connecting sheet 10b in the first direction AA' is equal to the distance between the positive electrode ear 42a and the negative electrode ear 42b of the first inner electrode group 42. The first inner electrode group 42 and the second inner electrode group 43 are placed flat on the positive electrode connecting sheet 10a and the negative electrode connecting sheet 10b (this surface is referred to as the front surface of the connecting sheet 10), so that the positive electrode ears 42a, 43a, and the negative electrode ears 42b, 43b of the first inner electrode group 42 and the second inner electrode group 43 are aligned with the connection area T1 and the connection area T2 of the positive electrode connecting sheet 10a and the connection area T1 and the connection area T2 of the negative electrode connecting sheet 10b, and welding is performed on these four locations. Figure 6-8 They are respectively a top view, a bottom view and a front view of the semi-finished battery assembly 20 after the welding in step S61 is completed. Figure 8 As shown, after welding, there is a certain distance between the first inner pole group 42 and the second inner pole group 43, which is twice the thickness of the pole group, so that the sides of the first inner pole group 42 and the second inner pole group 43 can fit each other after folding in step S63.

[0059] In step S62, the cover plate 30 is installed and placed on the side of the positive electrode connecting sheet 10a and the negative electrode connecting sheet 10b that is not in contact with the first inner electrode group 42 and the second inner electrode group 43 (this side is referred to as the back side of the connecting sheet 10). Figure 8 As shown, the positive electrode connecting piece 10a and the negative electrode connecting piece 10b are placed below the cover plate 30, and the positive electrode connecting part 30a and the negative electrode connecting part 30b of the cover plate 30 are aligned with the fixing part 101 of the positive electrode connecting piece 10a and the negative electrode connecting piece 10b respectively, and welding is performed on the front side of the positive electrode connecting piece 10a and the negative electrode connecting piece 10b. Figure 9-11 They are respectively a top view, a bottom view and a front view of the semi-finished battery assembly 20 after the welding is completed in step S62.

[0060] Next, in step S63, the positive electrode ears 42a, 43a and the negative electrode ears 42b, 43b of the first inner electrode group 42 and the second inner electrode group 43 are folded so that the first inner electrode group 42 and the second inner electrode group 43 are folded 90° in a direction away from the positive electrode connecting sheet 10a and the negative electrode connecting sheet 10b, and are attached to each other along the second direction BB'. Fig.12 As shown, a tool can also be used to clamp the bonded first inner pole group 42 and the second inner pole group 43 for subsequent operations.

[0061] In step S64, the first external electrode group 41 and the second external electrode group 44 are welded so that the positive electrode ears 41a, 44a and the negative electrode ears 41b, 44b of the first external electrode group 41 and the second external electrode group 44 are aligned with the connection area T3, connection area T4 of the positive electrode connecting piece 10a and the connection area T3, connection area T4 of the negative electrode connecting piece 10b, respectively, and welding is performed at these four locations. Figure 13-14 They are respectively a top view and a front view of the semi-finished battery assembly after welding is completed in step S64.

[0062] For further reference, Fig.14 As shown, after the welding is completed, there is a certain distance between the first outer electrode group 41 and the first inner electrode group 42, and between the second outer electrode group 44 and the second inner electrode group 43. The distance is the thickness of the electrode group, so that after the folding is completed in step S65, the side surfaces of the first outer electrode group 41 and the first inner electrode group 42, and the side surfaces of the second outer electrode group 44 and the second inner electrode group 43 can fit each other, and finally assemble into the following Figure 2-3 In the battery assembly 20 shown, the first outer electrode group 41, the first inner electrode group 42, the second inner electrode group 43 and the second outer electrode group 44 are adjacent to each other in sequence along the second direction BB', and the sides are fitted together, and the pole ears of each pole group are individually welded to the connecting sheet 10, and only one bending is required to form them, and the bending shape of the pole ears after folding is C-shaped.

[0063] Fig.15 is a top view of another connecting sheet 10' of the present application, Fig.16 is a side view of another battery assembly 20' of the present application, Fig.17 2 is a front view of another battery assembly 20' of the present application. Fig.15 In the embodiment shown, and Figure 1-3 Compared with the previous embodiment shown, the connecting piece 10' further includes a third connecting portion 130' located in the first direction AA' away from the first connecting portion 110' of the second connecting portion 120', and the first connecting portion 110', the second connecting portion 120', and the third connecting portion 130' are also distributed in a stepped manner, and the third connecting portion 130' has a connecting area T5 and a connecting area T6 respectively at a position close to its upper edge L5 and lower edge L6, respectively suitable for being electrically connected to the tab. In the second direction BB', the distance between the upper edge L5 of the third connecting portion 130' and the upper edge L1 of the first connecting portion 110' is greater than the distance between the upper edge L3 of the second connecting portion 120' and the upper edge L1 of the first connecting portion 110', and the distance between the lower edge L6 of the third connecting portion 130' and the lower edge L2 of the first connecting portion 110' is greater than the distance between the lower edge L4 of the second connecting portion 120' and the lower edge L2 of the first connecting portion 110'.

[0064] Similarly, the third connection part 130' and the second connection part 120' are adjacent connection parts 100, and the upper edges L3 and L5 of the two have a second distance H2 in the second direction BB', and the lower edges L4 and L6 have a third distance H3 in the second direction BB', and the second distance H2 and the third distance H3 are less than or equal to the second threshold value, that is, the thickness of the electrode group. After the electrode group connected to the first connection part 110' and the second connection part 120' is welded and folded, the connection area T5 and the connection area T6 still have enough parts to be exposed for subsequent welding, and when the six electrode groups are folded, they completely cover the connecting sheet 10' in the case of being fitted.

[0065] Figure 18-20 This application adopts Figure 4 Assembly method 50 Assembly as Figure 16-17 Schematic diagram of the process of the battery assembly 20'. Further, compared with the battery assembly 20 in the previous embodiment, the battery assembly 20' in this embodiment has a pole assembly 40', in addition to the first outer pole group 41', the first inner pole group 42', the second inner pole group 43' and the second outer pole group 44', further including a third pole group 45, 46 attached to the outside of the first outer pole group 41' and the second outer pole group 44'. In the actual installation process, when the first outer pole group 41', the first inner pole group 42', the second inner pole group 43' and the second outer pole group 44' have been welded and folded, and attached to each other, the third pole groups 45, 46 are welded to the third connecting portion 130' of the connecting sheet 10' and folded.

[0066] In some other embodiments of the present application, the connecting piece may also have a larger number of connecting parts and connecting areas, suitable for connecting and assembling a larger number of pole groups, and the present application does not impose any specific limitation thereto.

[0067] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0068] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0069] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0070] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used for the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which can be changed according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the method of general digit retention. Although the numerical domains and parameters used to confirm the breadth of the range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0071] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A connecting piece assembly, suitable for electrically connecting and fixing the tabs of a plurality of electrode groups, characterized in that: The connecting piece assembly includes two connecting pieces, each of which includes a plurality of connecting parts connected in sequence along a first direction, the plurality of connecting parts including a first connecting part, the plurality of connecting parts having an upper edge and a lower edge extending along the first direction and opposite to each other in a second direction perpendicular to the first direction, wherein: The multiple connecting portions are distributed in a stepped manner along the first direction, and in a direction away from the first connecting portion, the distance between the upper edges of the multiple connecting portions and the central axis of the connecting piece extending along the first direction in the second direction increases, and the distance between the lower edges of the multiple connecting portions and the central axis in the second direction increases; The plurality of connection portions each have a connection area near the corresponding upper edge and lower edge, which is suitable for being electrically connected to the tab.

2. The connecting piece assembly according to claim 1, characterized in that: The connecting piece is symmetrical about a central axis along the first direction.

3. The connecting piece assembly according to claim 1, characterized in that: The connecting piece further comprises a fixing portion connected to the connecting portion, and the fixing portion is suitable for being electrically connected to the cover plate.

4. The connecting piece assembly according to claim 3, characterized in that: The fixing portion is located on a side of the first connecting portion away from the other connecting portions in the first direction.

5. The connecting piece assembly according to claim 4, characterized in that: There is a first distance between the upper edge and the lower edge of the first connecting portion in the second direction, and the first distance is less than or equal to a first threshold value, which is twice the thickness of the pole group.

6. The connecting piece assembly according to claim 5, characterized in that: There is a second distance between the upper edges corresponding to two adjacent connecting parts in the second direction, and there is a third distance between the lower edges corresponding to two adjacent connecting parts in the second direction. The second distance and the third distance are less than or equal to a second threshold and greater than a third threshold. The second threshold is the thickness of the pole group, and the third threshold is 0.5 times the thickness of the pole group.

7. A battery assembly, characterized in that: include: A cover plate, wherein the inner side of the cover plate has a positive electrode connection portion and a negative electrode connection portion; The electrode group assembly comprises a plurality of electrode groups which are adjacent to each other in sequence along the second direction, and each of the electrode groups is provided with a positive electrode tab and a negative electrode tab; A connecting piece assembly, comprising two connecting pieces, each of the connecting pieces comprising a plurality of connecting parts connected in sequence along a first direction, the plurality of connecting parts comprising a first connecting part, the plurality of connecting parts having an upper edge and a lower edge extending along the first direction and opposite to each other in a second direction perpendicular to the first direction, the plurality of connecting parts being distributed in a stepped manner along the first direction, and in a direction away from the first connecting part, the distance between the upper edges of the plurality of connecting parts and a central axis of the connecting piece extending along the first direction in the second direction increases, and the distance between the lower edges of the plurality of connecting parts and the central axis in the second direction increases, and the plurality of connecting parts respectively have a connecting area at a position close to the corresponding upper edge and the corresponding lower edge; The two connecting sheets include a positive connecting sheet and a negative connecting sheet, the positive connecting portion and the negative connecting portion are respectively suitable for being electrically connected to the positive connecting sheet and the negative connecting sheet, the multiple connecting areas of the positive connecting sheet are respectively suitable for being electrically connected to the positive pole ears of the multiple pole groups, and the multiple connecting areas of the negative connecting sheet are respectively suitable for being electrically connected to the negative pole ears of the multiple pole groups.

8. The battery assembly according to claim 7, characterized in that: The connecting piece further comprises a fixing portion located on a side of the first connecting portion away from the other connecting portions, and the positive connecting portion and the negative connecting portion are respectively suitable for being electrically connected to the fixing portions of the positive connecting piece and the negative connecting piece.

9. The battery assembly according to claim 7, characterized in that: The pole group assembly comprises a first outer pole group, a first inner pole group, a second inner pole group and a second outer pole group which are adjacent to each other in sequence along the second direction; Each of the connecting plates of the connecting plate assembly includes a first connecting portion and a second connecting portion along the first direction, wherein the first connecting portion has a connecting area near the corresponding upper edge and the corresponding lower edge, respectively, and the second connecting portion has a connecting area near the corresponding upper edge and the corresponding lower edge, respectively.

10. The battery assembly according to claim 9, characterized in that: The positive electrode ears / negative electrode ears of the first inner electrode group and the second inner electrode group are opposite to each other in the second direction; The positive electrode tabs / negative electrode tabs of the first external electrode group and the second external electrode group are opposite to each other in the second direction; and The positive electrode tabs / negative electrode tabs of the first inner electrode group and the first outer electrode group are staggered in the second direction.

11. The battery assembly according to claim 10, characterized in that: The positive electrode ear / negative electrode ear of the first inner electrode group and the second inner electrode group are respectively suitable for being electrically connected to the connection area of ​​the first connection part of the positive electrode connecting sheet / negative electrode connecting sheet; The positive electrode tabs / negative electrode tabs of the first external electrode group and the second external electrode group are respectively suitable for being electrically connected to the connection areas of the second connection parts of the positive electrode connecting sheet / negative electrode connecting sheet.

12. An assembly method, characterized in that: Suitable for assembling the battery assembly according to any one of claims 7 to 11, the assembling method comprising the following steps: a. The positive and negative electrodes of the two electrode groups are welded together with the connection area of ​​the positive and negative electrode connectors, respectively; b. The positive electrode connection portion of the cover plate, the negative electrode connection portion and the positive electrode connection sheet, the negative electrode connection sheet are welded together; c folding the positive and negative electrodes of the two electrode groups welded in step a, so that the two electrode groups are bonded to each other along the second direction; d. welding the positive / negative ears of the other two electrode groups to the positive / negative electrode connecting piece which is closest to the first connecting portion and the remaining connecting portion; e. folding the positive and negative electrodes of the two electrode groups welded in step d so that the two electrode groups are respectively attached to adjacent electrode groups along the second direction; f. Repeat steps de until all pole groups are installed, and at this time all pole groups are sequentially fitted in the second direction.

13. The assembly method according to claim 12, characterized in that: The assembly method comprises the following steps: Welding the positive electrode ear / negative electrode ear of the first inner electrode group in the electrode group assembly and the second inner electrode group in the electrode group assembly to the connection area of ​​the first connection part of the positive electrode connecting piece / negative electrode connecting piece respectively; Welding the positive electrode connection part and the negative electrode connection part of the cover plate to the positive electrode connection sheet and the negative electrode connection sheet respectively; Folding the positive electrode ears and the negative electrode ears of the first inner electrode group and the second inner electrode group so that the first inner electrode group and the second inner electrode group are attached to each other along the second direction; Welding the positive electrode tab / negative electrode tab of the first external electrode group in the electrode group assembly and the second external electrode group in the electrode group assembly to the connection area of ​​the second connection part of the positive electrode connecting sheet / negative electrode connecting sheet respectively; and The positive electrode ears and the negative electrode ears of the first outer electrode group and the second outer electrode group are folded so that the first outer electrode group and the first inner electrode group, the second inner electrode group and the second outer electrode group are attached to each other along the second direction.

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