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, a second connecting part and a third connecting part, each connecting part is provided with an upper edge and a lower edge which extend in the first direction and are opposite in the second direction perpendicular to the first direction, the connecting piece is symmetrical about the central axis in the first direction, the connecting parts are distributed in a stepped mode in the first direction, and in the direction far away from the first connecting part, the upper edge and the lower edge of the connecting piece are arranged in a staggered mode. The distances between the upper edges and the central axes of the plurality of connecting parts in the second direction are increased, the distances between the lower edges and the central axes of the plurality of connecting parts in the second direction are increased, and the positions, close to the corresponding upper edges and lower edges, of the plurality of connecting parts are respectively provided with a connecting area which is suitable for being electrically connected with the tabs; the connecting piece is provided with a first surface and a second surface, the connecting piece is provided with a convex hull positioned on the first surface, and the plurality of connecting parts are respectively provided with a connecting area at the positions on the second surface close to the corresponding upper edge and lower edge, 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. As the size of single cells continues to increase, the thickness of cells is also getting larger. 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 a multi-electrode group solution for large cells to solve these process problems. In the existing technology, rectangular or U-shaped connecting pieces are usually used. First, multiple electrode groups are assembled in pairs, and then the tabs of each two electrode groups are overlapped and welded together to the corresponding positions of the connecting piece, and finally folded. However, this will cause the tabs to be folded multiple times, forming an S-shaped bend, and there is a risk of the tabs being inserted upside down into the electrode group, causing a short circuit. In addition, in this case, in order to ensure folding, the tabs usually have a high height. In the coating, rolling and winding processes, there is a risk of the tabs wrinkling or folding. 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 that can reduce the height of the tab, reduce the risk of wrinkles and folding, and make the tab bend into a C-shape.

[0004] To solve the above technical problems, the present invention provides a connecting piece assembly suitable for electrically connecting and fixing the tabs of multiple electrode groups, characterized in that the connecting piece assembly includes two connecting pieces, each of the connecting pieces includes a plurality of connecting parts connected in sequence along a first direction, the plurality of connecting parts include a first connecting part, the plurality of connecting parts have 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 the 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 piece extending along the first direction increases in the second direction, and the distance between the lower edges of the plurality of connecting parts and the central axis increases in the second direction, the plurality of connecting parts respectively have a connecting area at a position close to the corresponding upper edge and the lower edge thereof, suitable for electrically connecting to the tab; the connecting piece has a first surface and a second surface, the connecting piece has a convex bulge located on the first surface, and the plurality of connecting parts respectively have a connecting area at a position close to the corresponding upper edge and the lower edge thereof on the second surface.

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

[0006] In one embodiment of the present invention, the convex hull is located on a side of the first connecting portion on the first surface away from the other connecting portions.

[0007] In one embodiment of the present invention, a first distance is defined between an upper edge and a lower edge of the first connecting portion in the second direction. The first distance is less than or equal to a first threshold value, which is twice the thickness of the electrode group.

[0008] 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.

[0009] The present invention also provides a battery assembly, comprising: a cover plate, the cover plate having two through holes, the convex bumps of the positive connecting piece and the negative connecting piece being respectively suitable for connecting to the two through holes; a pole group assembly, comprising a plurality of pole groups adjacent to each other in sequence along a second direction, and each pole group is provided with a positive pole ear and a negative pole ear, the positive pole ear and the negative pole ear being respectively suitable for electrically connecting to the positive connecting piece and the negative connecting piece; a connecting piece assembly, comprising two connecting pieces, each of the connecting pieces comprising 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, wherein: the plurality of connecting portions are distributed in a stepped manner along the first direction, and in a direction away from the first connecting portion, a gap is formed between the upper edges of the plurality of connecting portions and the central axis of the connecting piece extending along the first direction in the second direction. The distance in the two directions 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 respectively have a connecting area at a position close to their corresponding upper edge and lower edge; the connecting piece has a first surface and a second surface, and the connecting piece has a bulge located on the first surface, and the multiple connecting parts respectively have a connecting area at a position close to their corresponding upper edge and lower edge located on the second surface, which is suitable for electrically connecting to the pole ears; the two connecting pieces include a positive pole connecting piece and a negative pole connecting piece, and the positive pole connecting part and the negative pole connecting part are respectively suitable for electrically connecting to the positive pole connecting piece and the negative pole connecting piece, and the multiple connecting areas of the positive pole connecting piece are respectively suitable for electrically connecting to the positive pole ears of the multiple pole groups, and the multiple connecting areas of the negative pole connecting piece are respectively suitable for electrically connecting to the negative pole ears of the multiple pole groups.

[0010] In one embodiment of the present invention, the through hole has a flange, the flange and the convex hull have the same height and are conformally matched, and the flange and the convex hull are fixed by welding.

[0011] 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 that 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 near its corresponding upper edge and lower edge, respectively, and the second connecting portion has a connecting area near its corresponding upper edge and the lower edge, respectively.

[0012] In one embodiment of the present invention, the positive electrode tabs / negative electrode tabs of the first inner electrode group and the second inner electrode group are opposite in the second direction; the positive electrode tabs / negative electrode tabs of the first outer electrode group and the second outer electrode group are opposite 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.

[0013] In one embodiment of the present invention, the positive electrode tabs / negative electrode tabs of the first inner electrode group and the second inner electrode group are respectively suitable for being electrically connected to the connection areas of the first connection parts of the positive electrode connecting sheet / negative electrode connecting sheet; the positive electrode tabs / negative electrode tabs of the first outer electrode group and the second outer 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.

[0014] 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 pieces respectively; b. folding the positive ears and 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; c. welding the positive / negative ears of the other two electrode groups to the connection areas of the positive / negative electrode connecting pieces that are closest to the first connection parts and are free at this time; d. folding the positive ears and negative ears of the two electrode groups welded in step c so that the two electrode groups are bonded to the adjacent electrode groups respectively along the second direction; e. repeating steps cd until all electrode groups are installed, and at this time all electrode groups are bonded in sequence in the second direction; f. welding the two through holes of the cover plate to the bulges on the positive and negative electrode connecting pieces respectively.

[0015] In one embodiment of the present invention, the assembly method includes the following steps: welding the positive electrode ears / negative electrode ears 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; folding the positive electrode ears and 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 mutually attached to each other along the second direction; welding the positive electrode ears / negative electrode ears 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; folding the positive electrode ears and 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 to each other along the second direction; and welding the two through holes of the cover plate to the bulges on the positive electrode connecting sheet and the negative electrode connecting sheet respectively.

[0016] Compared with the prior art, the present invention provides a connecting piece assembly, a battery assembly, and an assembly method thereof. Each electrode group's tab is individually welded to the connecting piece assembly, wherein the connecting piece is T-shaped. The tabs of the first and second inner electrode groups of the four electrode groups are welded to the narrower first and second sub-connecting portions of the connecting piece, while the first and second outer electrode groups are welded to the wider third and fourth sub-connecting portions. This reduces the tab height and ultimately requires only one bend, forming a C-shape. This reduces the risk of wrinkles and folding, and reduces the risk of short circuits. Furthermore, the connecting plate is integrated with a convex structure, eliminating the need to weld the cover plate during the electrode group welding process. The final snap-on installation is convenient and space-saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the present application, are incorporated into and constitute a part of this application, illustrate embodiments of the present application, and together with this specification serve to explain the principles of the present invention. In the accompanying drawings:

[0018] Figure 1 This is a top view of a connecting piece of the present application.

[0019] Figure 2 It is a three-dimensional schematic diagram of a battery assembly of the present application.

[0020] Figure 3A It is a flow chart of an assembly method of the present application.

[0021] Figure 3B It is a flow chart of another assembly method of the present application.

[0022] Figure 4A-8 This application adopts the assembly method as shown in Figure 3 to assemble Figure 2 Schematic diagram of the battery assembly process.

[0023] Figure 9 This is a top view of another connecting piece of the present application.

[0024] Figure 10 It is a three-dimensional schematic diagram of another battery assembly of the present application.

[0025] Figure 1-10 The reference numerals are described as follows:

[0026]

[0027] DETAILED DESCRIPTION

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0029] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0030] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​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 drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0031] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0032] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. 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 figures. For example, if the device in the 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.

[0033] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. Furthermore, while the terms used in this application are selected from commonly known and commonly used terms, some terms mentioned in this specification may have been selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of this description. Furthermore, this application should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0034] 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 can be directly on, connected to, coupled to, or contacting the other component, or intervening components may be present. 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, an electrical path exists between the first and second components that allows current to flow. This electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between the conductive components.

[0035] Flowcharts are used in this application to illustrate the operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the various steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0036] Figure 1 This is a top view of a connecting piece of the present application. Figure 1 As shown, the present invention provides a connecting piece assembly suitable for electrically connecting and fixing the tabs of multiple electrode 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 portions 100 connected in sequence along a first direction AA'. In this embodiment, the connecting portion 100 includes a first connecting portion 110 and a second connecting portion 120, and the first connecting portion 110 and the second connecting portion 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 portion 100 are opposite in a second direction BB' perpendicular to the first direction AA'.

[0037] Preferably, in this embodiment, the connecting piece may be symmetrical about the central axis O along the first direction AA′.

[0038] Specifically, refer to Figure 1As shown, 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 (in this embodiment, the upper edge L1 of the first connecting part 10 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 area 110 and the lower edge L4 of the second connecting part 120) and the central axis O on the second edge BB' increases. In other words, in the direction away from the first connecting part 110, the distance between the upper edge and the lower edge of the connecting part in the second direction BB' gradually increases (for details, please refer to Figure 9 ).

[0039] Furthermore, each of the plurality of connecting portions 100 has a connecting area near the corresponding upper edge and lower edge, suitable for electrically connecting to the tabs of the electrode group. Figure 1 Taking the embodiment shown as an example, the first connecting portion 110 has two connecting areas near the upper edge L1 and the lower edge L2, which are named as the connecting area T1 and the connecting area T2 for the convenience of distinction, and are suitable for electrically connecting to the tabs of the two electrode groups. The second connecting portion 120 also has two connecting areas near the upper edge L3 and the lower edge L4, which are named as the connecting area T3 and the connecting area T4 for the convenience of distinction, and are suitable for electrically connecting to the tabs of the other two electrode groups. Among them, the connecting areas T1, T2, T3, and T4 are respectively suitable for electrically connecting to the positive tabs of the four electrode groups or the negative tabs of the four electrode groups, depending on whether the connecting piece 10 is the positive electrode connecting piece 10a or the negative electrode connecting piece 10b (refer to FIG. 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.

[0040] In such Figure 1 In the embodiment shown, the connecting piece 10 has a first surface 11 and a second surface 12. Figure 1The figure shows a schematic diagram of the first surface 11 of the connecting piece 10. In this embodiment, the connecting piece 10 also has a bulge 101 located on the first surface 11. The first surface 11 provided with the bulge 101 is suitable for cooperating with the cover plate after installation, while the second surface 12 is suitable for cooperating with the electrode group. In other words, the connection areas T1, T2, T3, and T4 located on the second surface 12 are respectively suitable for electrically connecting to the positive tabs of the four electrode groups or the negative tabs of the four electrode groups, and the parts located on the first surface 11 do not contact the tabs. Furthermore, in this embodiment, the bulge 101 is located on the side of the connection area T1 on the first surface 11 away from the connection area T2, that is, Figure 1 Shown on the right.

[0041] In a preferred embodiment of the present invention, a first distance H1 is defined between the upper edge L1 and the lower edge L2 of the first connecting portion 110 in the second direction BB'. This distance H1 is less than or equal to a first threshold value, which is twice the thickness of the electrode assembly. This arrangement ensures that the electrode assemblies connected to the connection areas T1 and T2, after folding, completely shield the first connecting portion 110 when affixed to each other, preventing problems such as mis-welding during subsequent electrode assembly welding.

[0042] In the present invention, Figure 1 In the preferred embodiment shown, a second distance H2 is provided between the upper edges (i.e., L1 and L3) corresponding to two adjacent connecting portions (i.e., the first connecting portion 110 and the second connecting portion 120) in the second direction BB', and a third distance H3 is provided between the lower edges (i.e., L2 and L4) corresponding to two adjacent connecting portions (i.e., the first connecting portion 110 and the second connecting portion 120) in the second direction BB', and the second distance H2 and the third distance H3 are less than or equal to a second threshold value and greater than a third threshold value, the second threshold value being the thickness of the electrode group, and the third threshold value being 0.5 times the thickness of the electrode group. It will be understood that the second distance H2 and the third distance H3 are greater than the third threshold value to ensure that after the electrode group connected to the connection areas T1 and T2 is folded, there is still enough space between the connection areas T3 and T4 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 electrode groups are folded, they completely cover the portion between the upper and lower edges of the second connection portion 120 of the connecting sheet 10 when they are in contact. Furthermore, when the connecting sheet has more connecting parts, the distance relationship between the upper and lower edges of two adjacent connecting parts in the second direction BB′ all meets the above conditions, thereby ensuring the accuracy of welding.

[0043] Figure 2 This is a three-dimensional schematic diagram of a battery assembly of the present application. Figure 2As shown, the present invention further provides a battery assembly 20, including a cover plate 30, an electrode assembly 40, and a connecting piece assembly proposed in any embodiment of the present application, such as the connecting piece assembly described above. 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 are no other differences except for polarity. The cover plate 30 has two through-holes 31 extending therethrough, and the bumps 101 of the positive and negative electrode connecting tabs 10a and 10b are respectively adapted to electrically connect to the two through-holes 31. In this preferred embodiment, the through-holes 31 have flanges 32. The flanges 32 and bumps 101 are of the same height and conform to each other, and are secured to each other by welding.

[0044] Furthermore, in this 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 tab 41a and a negative electrode tab 41b, the first inner electrode group 42 is provided with a positive electrode tab 42a and a negative electrode tab 42b, the second inner electrode group 43 is provided with a positive electrode tab 43a and a negative electrode tab 43b, and the second outer electrode group 44 is provided with a positive electrode tab 44a and a negative electrode tab 44b. The positive electrode tabs 41a, 42a, 43a, and 44a are suitable for electrical connection to the positive electrode connecting tab 10a, and the negative electrode tabs 41b, 42b, 43b, and 44b are suitable for electrical connection to the negative electrode connecting tab 10b.

[0045] Specifically, in this embodiment, the connection areas T1, T2, T3, and T4 of the positive electrode connecting piece 10a are respectively adapted to electrically connect to the positive electrode tabs 41a, 42a, 43a, and 44a of the four electrode groups 41, 42, 43, and 44. The connection areas T1, T2, T3, and T4 of the negative electrode connecting piece 10b are respectively adapted to electrically connect to the negative electrode tabs 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 correspondence for the above connections. For details, please refer to the description of the assembly method below.

[0046] It is understandable that since the connection areas T1 and T2 in the connecting sheet 10 are opposite in the second direction BB', the connection areas T3 and T4 are opposite in the second direction BB', and the connection areas T1 and T3 are staggered in the second direction BB', in order to ensure that the four electrode groups are completely aligned and fit together after folding, their positive and negative electrode tabs must also be adaptively arranged. Specifically, the positive electrode tabs 42a and 43a (or negative electrode tabs 42b and 43b) of the first inner electrode group 42 and the second inner electrode group 43 are opposite in the second direction BB'; the positive electrode tabs 41a and 44a (or negative electrode tabs 41b and 44b) of the first outer electrode group 41 and the second outer electrode group 44 are opposite in the second direction BB'; and the positive electrode tabs 42a and 41a (or negative electrode tabs 42b and 41b) of the first inner electrode group 42 and the first outer electrode group 41 are staggered in the second direction BB'.

[0047] In such Figure 2 In the illustrated embodiment, the positive electrode ears 42a, 43a (or the negative electrode ears 42b, 43b) of the first inner electrode group 42 and the second inner electrode group 43 are respectively adapted to be electrically connected to the connection areas T1 and T2 of the positive electrode connecting sheet 10a (or the negative electrode connecting sheet 10b); the positive electrode ears 41a, 44a (or the negative electrode ears 41b, 44b) of the first outer electrode group 41 and the second outer electrode group 44 are respectively adapted to be electrically connected to the connection areas T3 and T4 of the positive electrode connecting sheet 10a (or the negative electrode connecting sheet 10b) (due to angle reasons, some structures are in Figure 2 For details, please refer to the following description of the assembly steps).

[0048] 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 will be welded and folded first. Therefore, it is necessary to set an electrical connection with the connection areas T1 and T2 of the connecting piece 10 to ensure that the outer first outer pole group 41 and the second outer pole group 44 can continue to be welded and folded after folding. However, the correspondence between the first inner pole group 42, the second inner pole group 43 and the connection areas T1 and T2, as well as the correspondence between the first outer pole group 41 and the second outer pole group 44 and the connection areas T3 and T4, are not specifically limited in this application.

[0049] Figure 3A This is a flow chart of an assembly method of the present application. Figure 3A As shown, the present invention further provides an assembly method 50 suitable for assembling a battery assembly as in any of the previous embodiments. The assembly method 50 comprises the following steps:

[0050] S51: Welding the positive electrode tabs / negative electrode tabs of the two electrode groups to the connection areas of the first connection portions of the positive electrode connecting piece / negative electrode connecting piece, respectively;

[0051] S52: Folding the positive electrode tabs and the negative electrode tabs of the two electrode groups welded in step S51 so that the two electrode groups are bonded to each other along the second direction;

[0052] S53: Welding the positive / negative tabs of the other two electrode groups to the connection areas of the positive / negative connecting pieces that are closest to the first connecting portion and the remaining connecting portion;

[0053] S54: folding the positive electrode tabs and the negative electrode tabs of the two electrode groups welded in step S53 so that the two electrode groups are respectively attached to the adjacent electrode groups along the second direction;

[0054] S55: Repeat steps S53-S54 until all electrode groups are installed and all electrode groups are sequentially attached in the second direction;

[0055] S56: Welding the two through holes of the cover plate to the convex bumps on the positive electrode connecting piece and the negative electrode connecting piece respectively.

[0056] Specifically, when assembling Figure 2 When the battery assembly 20 shown has four electrode groups, the assembly method 50 is preferably as follows: Figure 3B Assembly method 60 shown:

[0057] S61: Welding the positive electrode tabs / negative electrode tabs of the first inner electrode group and the second inner electrode group to the connection areas of the first connection portions of the positive electrode connecting piece / negative electrode connecting piece, respectively.

[0058] S62: Folding the positive electrode tabs and the negative electrode tabs 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.

[0059] S63: Welding the positive electrode tabs / negative electrode tabs of the first and second external electrode groups to the connection areas of the second connection portions of the positive electrode connecting piece / negative electrode connecting piece, respectively.

[0060] S64: Fold the positive electrode tabs and the negative electrode tabs 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 attached to each other along the second direction.

[0061] S65: Welding the two through holes of the cover plate to the convex bumps on the positive electrode connecting piece and the negative electrode connecting piece respectively.

[0062] Figure 4A-8 This application adopts Figure 3B Assembly method of assembly as follows Figure 2 Schematic diagram of the battery assembly process, combined with reference Figure 1-8 The assembly method 60 and the battery assembly 20 are described in detail as follows:

[0063] First, in step S61, the positive electrode connecting tab 10a and the negative electrode connecting tab 10b are aligned along the first direction AA', with their ends having the bumps 101 facing each other. The distance between the connection areas T1 of the positive electrode connecting tab 10a and the negative electrode connecting tab 10b in the first direction AA' is equal to the distance between the positive electrode tab 42a and the negative electrode tab 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 second surfaces 12 of the positive electrode connecting tab 10a and the negative electrode connecting tab 10b, respectively, with the positive electrode tabs 42a, 43a and the negative electrode tabs 42b, 43b of the first inner electrode group 42 and the second inner electrode group 43 aligned with the connection areas T1 and T2 of the positive electrode connecting tab 10a and the connection areas T1 and T2 of the negative electrode connecting tab 10b, respectively. Welding is then performed at these four locations. Figures 4A-4C They are respectively the view of the semi-finished battery assembly from the second surface 12, the first surface 11 and the front view after the welding in step S61 is completed. Figure 4C As shown, after welding is completed, 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 side surfaces of the first inner pole group 42 and the second inner pole group 43 can fit together after folding in step S62.

[0064] In step S62, since the bump 101 in the battery assembly 20 provided by the present invention has been integrated on the connecting piece 10, there is no need to weld the cover plate 30 in advance, and the welded first inner electrode group 42 and the second inner electrode group 43 can be directly folded. The positive electrode tabs 42a, 43a and the negative electrode tabs 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 degrees in the direction away from the connecting pieces 10a, 10b, and are affixed to each other along the second direction BB', and finally as shown in FIG. Figure 5 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.

[0065] Next, in step S63, the first external pole group 41 and the second external pole group 44 are welded so that the positive pole ears 41a, 44a and the negative pole ears 41b, 44b of the first external pole group 41 and the second external pole group 44 are aligned with the connection areas T3, T4 of the positive electrode connecting piece 10a and the connection areas T3, T4 of the negative electrode connecting piece 10b, respectively, and welding is performed at these four locations. Figures 6A-6B They are respectively a view from the second surface 12 and a front view of the semi-finished battery assembly after the welding in step S64 is completed.

[0066] For further reference, Figure 6BAs 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 S64, 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 together (as shown in FIG. Figures 7A-7B As shown), the final assembly becomes as follows Figure 2 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 side surfaces are in contact with each other. The pole ears of each pole group are individually welded to the connecting sheet and can be formed by bending once. After folding, the bending shape of the pole ears is C-shaped.

[0067] Finally, in step S65, the cover plate 30 is installed. The cover plate 30 is placed on the first surface 11 of the connecting tabs 10a and 10b. The two through-holes 130 of the cover plate 30 are aligned with the bumps 101 of the positive and negative connecting tabs 10a and 10b, respectively, and the cover plate 30 is pressed downward to complete the installation. It is important to note that in this step, the side of the through-hole 31 without the flange 32 should be oriented toward the bump 101. This ensures that the bump 101 is protected by the flange 32 after installation.

[0068] Figure 9 This is a top view of another connecting piece of the present application. Figure 10 This is a three-dimensional schematic diagram of another battery assembly of the present application. Figure 9-10 As shown, in another embodiment of the present application, and Figure 1-2 Compared to the previous embodiment shown, the connecting sheet further includes a third connecting area 130' located in the first direction AA' away from the first connecting area 110' from the second connecting area 120'. The first connecting area 110', the second connecting area 120', and the third connecting area 130' are also arranged in a stepped manner. When the six electrode groups are folded and attached, they completely cover the connecting sheet 10'.

[0069] Furthermore, compared with the battery assembly 20 in the previous embodiment, the battery assembly 20' in this embodiment includes six adjacent electrode groups. In some other embodiments of the present application, the connecting piece can also have a larger number of connection areas and sub-connection parts, which are suitable for connecting and assembling a larger number of electrode groups. The present application does not impose any specific restrictions on this.

[0070] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

[0071] At the same time, this application uses specific terms to describe the embodiments of this 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 this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0072] Similarly, it should be noted that, in order to simplify the presentation of this application and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0073] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change 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 general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0074] 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 can 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 scope of 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 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 multiple connecting parts 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 parts and the central axis in the second direction increases, and the multiple connecting parts respectively have a connecting area at a position close to the corresponding upper edge and the lower edge thereof, which is suitable for being electrically connected to the tab; The connecting piece has a first surface and a second surface. The connecting piece has a convex bulge on the first surface. The multiple connecting parts each have a connecting area on the second surface near the corresponding upper edge and lower edge.

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 convex hull is located on a side of the first connecting portion on the first surface away from the other connecting portions.

4. The connecting piece assembly according to claim 1, 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.

5. The connecting piece assembly according to claim 4, 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.

6. A battery assembly, characterized in that: include: A cover plate, wherein the cover plate has two through holes, and the convex bulges of the positive electrode connecting piece and the negative electrode connecting piece are respectively suitable for connecting with the two through holes; 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 ear and a negative electrode ear, wherein the positive electrode ear and the negative electrode ear are respectively suitable for being electrically connected to the positive electrode connecting sheet and the negative electrode connecting sheet; A connecting piece assembly, comprising two connecting pieces, each of which comprises a plurality of connecting parts connected in sequence along a first direction, wherein the plurality of connecting parts comprises a first connecting part, wherein the plurality of connecting parts have 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 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 positions close to the corresponding upper edges and lower edges thereof, which are suitable for being electrically connected to a tab; the connecting piece comprises a first surface and a second surface, the connecting piece comprises a convex bulge located on the first surface, and the plurality of connecting parts respectively have a connecting area at positions close to the corresponding upper edges and lower edges thereof on the second surface; The two connecting plates include the positive connecting plate and the negative connecting plate, the positive connecting portion and the negative connecting portion are respectively suitable for being electrically connected to the positive connecting plate and the negative connecting plate, the multiple connecting areas of the positive connecting plate 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 plate are respectively suitable for being electrically connected to the negative pole ears of the multiple pole groups.

7. The battery assembly according to claim 6, characterized in that: The through hole has a flange, the flange and the convex hump have the same height and are conformally matched, and the flange and the convex hump are fixed by welding.

8. The battery assembly according to claim 6, 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.

9. The battery assembly according to claim 8, 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.

10. The battery assembly according to claim 9, 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.

11. An assembly method, characterized in that: Suitable for assembling the battery assembly according to any one of claims 6 to 10, the assembling method comprising the following steps: a. Welding the positive / negative tabs of the two electrode groups to the connection areas of the first connection portions of the positive / negative electrode connectors, respectively; b. folding the positive and negative electrode 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; c. welding the positive / negative tabs of the other two electrode groups to the connection areas of the positive / negative connecting sheet which are closest to the first connecting portion and are left vacant; d. folding the positive and negative electrode ears of the two electrode groups welded in step c so that the two electrode groups are respectively attached to adjacent electrode groups along the second direction; e. Repeat steps cd until all pole groups are installed, and at this time all pole groups are sequentially fitted in the second direction; f. Welding the two through holes of the cover plate to the convex bumps on the positive electrode connecting piece and the negative electrode connecting piece, respectively.

12. The assembly method according to claim 11, 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; 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 ear / negative electrode ear 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; 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; and The two through holes of the cover plate are welded together with the convex bumps on the positive electrode connecting piece and the negative electrode connecting piece respectively.

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