Battery assembly and battery

Abstract

According to the battery assembly provided by the utility model, the first battery cell main body and the second battery cell main body are stacked together along the thickness direction, and the switching piece is arranged above the top surface of the first battery cell main body and the top surface of the second battery cell main body and comprises the tab connecting part; the first tab and the second tab are bent and then welded with the upper surface of the tab connecting part, and the first tab and the second tab are mutually overlapped to form an overlapping region, so that the first battery cell, the second battery cell and the tab connecting part are welded in the overlapping region to form a first welding mark. Due to the fact that the first welding mark can fix the first electrode lug and the second electrode lug which are bent, the battery assembly is not prone to contact between the electrode lugs and the electrode pieces, and therefore the risk that the electrode pieces are opened or the battery is short-circuited is reduced. Besides, less allowance is reserved for welding, and the length of the first tab and the length of the second tab of the battery assembly can be shortened, so that the manufacturing cost of the battery assembly is reduced.

Description

Technical Field

[0001] The utility model mainly relates to the technical field of batteries, and in particular to a battery assembly and a battery. Background Art

[0002] At present, the tabs of lithium-ion batteries are usually in a "C" shape. This is because in the conventional battery assembly process using flat ultrasonic welding, the distance between the two cells is required to be greater than the width of the cover plate, which will result in a relatively long welding redundancy of the tabs. During the core assembly process, the tabs need to be folded between the cell and the shell, and the folded tabs eventually present a "C" shape. However, due to the limited space between the cell and the shell, the folded tabs may pull on the pole pieces inside the cell, causing the pole pieces to open. In some cases, the tabs may also rub against the pole pieces of the cell due to vibration, collision and other factors, causing the risk of battery short circuit. Utility Model Content

[0003] The utility model aims to provide a battery assembly and an electrochemical device, which are used to solve the problem that the existing "C"-shaped lithium-ion battery is prone to pole piece opening or battery short circuit.

[0004] The utility model provides a battery assembly, comprising:

[0005] A first battery cell comprises a first battery cell body and a first pole lug extending from the top surface of the first battery cell body; a second battery cell is stacked together with the first battery cell in a thickness direction, the second battery cell comprises a second battery cell body and a second pole lug extending from the top surface of the second battery cell body; a transition piece is arranged above the top surface of the first battery cell body and the top surface of the second battery cell body, the transition piece comprises a pole lug connecting portion, wherein the first pole lug and the second pole lug are welded to the upper surface of the transition pole lug connecting portion after being bent, and the first pole lug and the second pole lug overlap each other to form an overlapping area, and the first battery cell, the second battery cell and the pole lug connecting portion are welded in the overlapping area to form a first weld mark.

[0006] In an embodiment of the present invention, the height of the first pole tab is smaller than the thickness of the first battery cell, and / or the height of the second pole tab is smaller than the thickness of the second battery cell.

[0007] In an embodiment of the present invention, the height of the first pole tab is 3-20 mm, and / or the height of the second pole tab is 3-20 mm.

[0008] In one embodiment of the utility model, the first weld mark is located in the overlapping area, and along the thickness direction, the first pole ear and the second pole ear are respectively welded to the adapter sheet on both sides of the overlapping area to form a second weld mark, wherein the second weld mark is arranged alternately with the first weld mark along the thickness direction, or the first pole ear and the second pole ear are completely pressed together in the overlapping area, and along the thickness direction, the length of the first weld mark is greater than the length of the overlapping area.

[0009] In an embodiment of the present invention, a plurality of first weld marks are formed in the overlapping area, and the plurality of first weld marks are arranged at intervals along the width direction.

[0010] In one embodiment of the present invention, the first pole lug includes a plurality of first sub-pole lugs, which are gathered and welded together on a side away from the first battery cell body to form a first connection area, and the first connection area is used to be welded to the adapter; and / or, the second pole lug includes a plurality of second sub-pole lugs, which are gathered and welded together on a side away from the second battery cell body to form a second connection area, and the second connection area is used to be welded to the adapter.

[0011] In one embodiment of the present invention, along the height direction, the distance between the first connection area and the top surface of the first battery cell body is 3-15mm; and / or, along the height direction, the distance between the second connection area and the top surface of the second battery cell body is 3-15mm.

[0012] In a second aspect, the utility model further discloses a battery, comprising a battery assembly as described in any one of the above-mentioned first aspects.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] (1) The utility model provides a battery assembly, wherein a first battery cell body and a second battery cell body are stacked together in the thickness direction, and a transfer plate is arranged on the top surface of the first battery cell body and above the top surface of the second battery cell body, the transfer plate includes a pole ear connection portion, and the first pole ear and the second pole ear are welded to the upper surface of the transfer plate after being bent, and the first pole ear and the second pole ear are overlapped with each other to form an overlapping area, so that the first battery cell, the second battery cell and the pole ear connection portion are welded in the overlapping area to form a first weld mark. Since the first pole ear and the second pole ear are welded to the upper surface of the transfer plate after being bent, the first weld mark will fix the first pole ear and the second pole ear after being bent, so the battery assembly involved in the utility model is not prone to contact between the pole ear and the pole piece, thereby reducing the risk of pole piece opening or battery short circuit. In addition, welding can be achieved by retaining a small amount of pole ear length margin, and the battery assembly involved in the utility model can also shorten the length of the first pole ear and the second pole ear, thereby reducing the manufacturing cost of the battery assembly.

[0015] (2) By allowing the first electrode tab and the second electrode tab to overlap each other to form an overlapping area, welding integration of different electrode tabs can be achieved, thereby improving the consistency of welding between different electrode tabs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are included to provide a further understanding of the present application. 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 application. In the accompanying drawings:

[0017] Figure 1 is a structural schematic diagram of a battery assembly provided in one embodiment of the present application;

[0018] Figure 2 is a side view of the battery assembly;

[0019] Figure 3 It is a schematic diagram of a first welding mark and a second welding mark provided in an embodiment of the present application;

[0020] Figure 4 is a schematic diagram of another first welding print provided by an embodiment of the present application;

[0021] Figure 5 It is a schematic diagram of a first sub-electrode tab and a second sub-electrode tab provided in one embodiment of the present application;

[0022] Figure 6 is a schematic diagram of a first connection area and a second connection area provided in an embodiment of the present application;

[0023] Figure 7 It is a schematic diagram of the structure of a battery provided in one embodiment of the present application. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The embodiments of the present utility model describe a battery assembly and a battery.

[0031] Figure 1 It is a structural schematic diagram of a battery assembly provided in one embodiment of the present application.

[0032] refer to Figure 1 , Figure 2 The battery assembly includes a first battery cell 1, a second battery cell 2 and a transfer sheet 3. The first battery cell 1 includes a first battery cell body 11 and a first pole tab 10. The second battery cell 2 includes a second battery cell body 21 and a second pole tab 20.

[0033] refer to Figure 1 In the battery assembly, the first battery cell body 11 and the second battery cell body 21 are stacked together along the thickness direction. The width direction, thickness direction and height direction of the first battery cell 1 and the second battery cell 2 are consistent. Figure 1 The x direction is shown, and the thickness direction is Figure 1 The y direction is shown, and the height direction is Figure 1The z direction is shown. The first pole tab 10 extends from the top surface of the first battery cell body 11. The second pole tab 20 extends from the top surface of the second battery cell body 21. For the first battery cell 1, the first battery cell 1 is usually provided with a positive pole tab and a negative pole tab, and the first pole tab 10 can be a positive pole tab or a negative pole tab. Similarly, for the second battery cell 2, the second battery cell 2 is also usually provided with a positive pole tab and a negative pole tab, and the second pole tab 20 is a pole tab with the same polarity as the first pole tab 10, that is, the first pole tab 10 and the second pole tab 20 are both positive pole tabs or negative pole tabs.

[0034] Continue to refer Figure 1 , Figure 2 In the battery assembly, the adapter sheet 3 is arranged on the top surface of the first battery cell body 11 and the top surface of the second battery cell body 21. Figure 1 The top surface is determined by the height direction shown. The adapter plate 3 includes a tab connection portion 30. The first tab 10 and the second tab 20 are bent and welded to the upper surface of the tab connection portion 30. The upper surface is also along Figure 1 The upper surface is determined in the height direction shown. The first pole tab 10 and the second pole tab 20 overlap each other to form an overlapping area 4, and the first battery cell 1, the second battery cell 2 and the pole tab connection portion 30 are welded in the overlapping area 4 to form a first weld mark 5. The first weld mark 5 can be one or more, and the multiple first weld marks 5 are spaced apart along the width direction.

[0035] The advantage of the utility model is that the battery assembly is stacked together along the thickness direction of the first battery cell body 11 and the second battery cell body 21, and a transfer plate 3 is arranged on the top surface of the first battery cell body 11 and above the top surface of the second battery cell body 21, and the transfer plate 3 includes a pole ear connection portion 30, so that the first pole ear 10 and the second pole ear 20 are welded to the upper surface of the pole ear connection portion 30 after being bent, and the first pole ear 10 and the second pole ear 20 are overlapped with each other to form an overlapping area 4, so that the first battery cell 1, the second battery cell 2 and the pole ear connection portion 30 are welded in the overlapping area 4 to form a first weld mark 5. Since the first pole ear 10 and the second pole ear 20 are welded to the upper surface of the pole ear connection portion 30 after being bent, the first weld mark 5 will fix the bent first pole ear 10 and the second pole ear 20, so in the battery assembly, the first pole ear 10 and the second pole ear 20 will not touch the first battery cell body 11 and the second battery cell body 21 due to external factors.

[0036] In this way, it is not easy for the pole tab to contact the pole piece in the battery cell assembly 100, thereby reducing the risk of pole piece opening or battery short circuit. In addition, by allowing the first pole tab 10 and the second pole tab 20 to overlap each other to form an overlapping area, welding of different pole tabs can be integrated, thereby improving the consistency of welding between different pole tabs.

[0037] In one embodiment of the present invention, the height of the first pole tab 10 is less than the thickness of the first battery cell 1, and / or the height of the second pole tab 20 is less than the thickness of the second battery cell 2. Preferably, the height of the first pole tab 10 is 3-20 mm, and / or the height of the second pole tab 20 is 3-20 mm. It is particularly noted that the height of the pole tab in this application refers to the height of the pole tab at the Figure 6 The dimensions along the z direction are shown in the upright position.

[0038] Continue to refer Figure 1 , Figure 2 , exemplarily showing that the height of the first pole tab 10 is less than the thickness of the first battery cell 1, and the height of the second pole tab 10 is less than the thickness of the second battery cell 2. Compared with conventional battery assemblies, in the structure of the battery assembly 100, the bent first pole tab 10 and the second pole tab 20 are roughly "L" shaped, so that the length of the pole tabs for welding can be shorter, so that the height of the first pole tab 10 and the second pole tab 20 can be shorter than the setting height of the pole piece in the conventional battery assembly, so as to save the manufacturing cost of the battery assembly 100.

[0039] refer to Figure 3 In one embodiment of the utility model, the first weld mark 5 is located in the overlapping area 4, and along the thickness direction, the first pole ear 10 and the second pole ear 20 are respectively welded to the adapter sheet 3 on both sides of the overlapping area 4 to form a second weld mark 6. The second weld mark 6 is arranged at intervals with the first weld mark 5 along the thickness direction of the first battery cell 1. The advantage of this is that the first battery cell 1, the second battery cell 2 and the adapter sheet 3 can be connected and fixed by the first weld mark 5 and the second weld mark 6 at the same time, thereby increasing the tightness of the connection. Moreover, since the first weld mark 5 and the second weld mark 6 are arranged at intervals, the first weld mark 5 is located in the overlapping area 4, and the second weld mark 6 is located outside the overlapping area 4, the intersection where the first pole ear 10 and the second pole ear 20 overlap (i.e., the two ends of the overlapping area 4 along the thickness direction) can be avoided. The intersection where the first pole ear 10 and the second pole ear 20 overlap is prone to produce a gap. When there is a gap, welding instability is likely to occur, resulting in a burst point. By making the weld mark avoid the intersection, the stability of the welding can be improved, thereby ensuring the stability of the structure of the battery assembly 100.

[0040] refer to Figure 4 In one embodiment of the present invention, the first pole tab 10 and the second pole tab 20 are completely pressed together in the overlapping area 4, and along the thickness direction, the length of the first weld mark 5 is greater than the length of the overlapping area 4 along the first battery cell 1. The advantage of this is that the overlapping parts of the first pole tab 10 and the second pole tab 20 in the overlapping area 4 are completely pressed together (that is, the overlapping parts of the first pole tab 10 and the second pole tab 20 and the overlapping intersections thereof are tightly fitted without any gap, refer to Figure 2), since there is no gap between the first pole ear 10, the second pole ear 20 and the adapter sheet 3, unstable welding is not easy to occur during welding. In addition, along the thickness direction, the length of the first weld mark 5 is greater than the length of the overlapping area 4 along the thickness direction of the first battery cell 1, which can improve the stability of welding and has a higher welding efficiency.

[0041] refer to Figure 5 In one embodiment of the present invention, the first pole tab 10 includes a plurality of first sub-pole tabs 100, and / or the second pole tab 20 includes a plurality of second sub-pole tabs 200. Figure 6 , a plurality of first sub-electrode tabs 100 are gathered and welded on one side away from the first battery body 11 to form a first connection area 101, wherein the first connection area 101 is used to be welded with the adapter 3. And / or, a plurality of second sub-electrode tabs 200 are gathered and welded on one side away from the second battery body 21 to form a second connection area 201, wherein the second connection area is used to be welded with the adapter 3.

[0042] As a preferred embodiment, along the height direction, the distance between the first connection area 101 and the top surface of the first battery body 11 is 3-15mm; and / or, along the height direction, the distance between the second connection area 201 and the top surface of the second battery body 21 is 3-15mm. In this embodiment, the distance between the first connection area 101 and the top surface of the first battery body 11 refers to the distance between the tabs. Figure 6 In the vertical state shown, the distance between the lower end of the first connection area 101 and the top surface of the first battery body 11, and the distance between the second connection area 201 and the top surface of the second battery body 21 also refers to the distance between the tabs. Figure 6 The distances shown are in the upright position.

[0043] As a preferred embodiment, the angle between the root of the first sub-electrode tab 100 and the top surface of the first battery cell body 11 is in the range of 10-60°; and / or the angle between the root of the second sub-electrode tab 200 and the top surface of the second battery cell body 21 is in the range of 10-60°.

[0044] As a preferred embodiment, along the thickness direction, the length of the overlap region 4 is 1-15 mm. If the length of the overlap region 4 is too short, the welding strength will be insufficient, and if the length is too long, the cost will increase.

[0045] further, Figure 7 1 is a schematic diagram of a battery structure provided in an embodiment of the present application, wherein the battery comprises one or more battery cell assemblies 70, and each battery cell assembly 70 can be any battery assembly involved in the above embodiments.

[0046] refer to Figure 7The battery includes two or more battery cell assemblies 70 (for ease of understanding, two are shown in the figure as examples, respectively labeled as 70a and 70b). The battery cell assembly 70a and the battery cell assembly 70b can be stacked together in the thickness direction, so as to be suitable for energy storage purposes. The technical effects of the battery can be specifically referred to the description in the above embodiment, which will not be repeated here.

[0047] The basic concepts have been described above. Obviously, for those skilled in the art, the above utility model disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to the present application. Such modifications, improvements and corrections are suggested in the present application, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present application.

[0048] 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 utility model embodiments, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, drawing 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.

[0049] In some embodiments, numbers describing the number of components and attributes are used. 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 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 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 setting of such numerical values ​​is as accurate as possible within the feasible range.

[0050] 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 battery assembly, characterized in that: include: A first battery cell, comprising a first battery cell body and a first electrode tab extending from a top surface of the first battery cell body; A second battery cell, stacked together with the first battery cell in a thickness direction, the second battery cell comprising a second battery cell body and a second electrode tab extending from a top surface of the second battery cell body; A transition piece is arranged above the top surface of the first battery cell body and the top surface of the second battery cell body, and the transition piece includes a pole ear connecting portion, wherein the first pole ear and the second pole ear are welded to the upper surface of the pole ear connecting portion after being bent, and the first pole ear and the second pole ear overlap each other to form an overlapping area, and the first battery cell, the second battery cell and the pole ear connecting portion are welded in the overlapping area to form a first weld mark.

2. The battery assembly according to claim 1, characterized in that The height of the first pole tab is smaller than the thickness of the first battery cell, and / or the height of the second pole tab is smaller than the thickness of the second battery cell.

3. The battery assembly according to claim 2, characterized in that: The height of the first pole tab is 3-20 mm, and / or the height of the second pole tab is 3-20 mm.

4. The battery assembly according to claim 1, wherein: The first weld mark is located in the overlapping area, and along the thickness direction, the first pole ear and the second pole ear are respectively welded to the adapter sheet on both sides of the overlapping area to form a second weld mark, wherein the second weld mark is arranged alternately with the first weld mark along the thickness direction; or the first pole ear and the second pole ear are completely pressed together in the overlapping area, and along the thickness direction, the length of the first weld mark is greater than the length of the overlapping area.

5. The battery assembly according to claim 1, characterized in that: The overlapping area is formed with a plurality of the first welding marks, and the plurality of the first welding marks are arranged at intervals along the width direction.

6. The battery assembly according to claim 1, characterized in that: The first pole lug includes a plurality of first sub-pole lugs, which are gathered and welded together on a side away from the first battery cell body to form a first connection area, and the first connection area is used to be welded to the adapter; and / or, the second pole lug includes a plurality of second sub-pole lugs, which are gathered and welded together on a side away from the second battery cell body to form a second connection area, and the second connection area is used to be welded to the adapter.

7. The battery assembly according to claim 6, characterized in that: Along the height direction, the distance between the first connection area and the top surface of the first battery cell body is 3-15 mm; and / or, along the height direction, the distance between the second connection area and the top surface of the second battery cell body is 3-15 mm.

8. The battery assembly according to claim 6, characterized in that: The angle between the root of the first sub-pole tab and the top surface of the first battery cell body is in the range of 10-60°; and / or the angle between the root of the second sub-pole tab and the top surface of the second battery cell body is in the range of 10-60°.

9. The battery assembly according to claim 1, wherein: Along the thickness direction, the length of the overlapping area is 1-15 mm.

10. A battery, characterized in that: Comprising a battery assembly as described in any one of claims 1-9.

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