Connecting piece, battery cell, battery and vehicle

Abstract

The utility model provides a connecting piece, a battery cell, a battery and a vehicle. The connecting piece comprises a main body part and at least two tab connecting parts, each tab connecting part is connected with the main body part, the at least two tab connecting parts are located on the same side of the main body part, and the tab connecting parts located on the same side of the main body part are staggered in the thickness direction of the connecting piece. The battery cell comprises one or more naked battery cells, each naked battery cell comprises a pole piece unit, at least one naked battery cell is provided with two or more tabs with the same polarity, and the tabs with the same polarity of the same naked battery cell are staggered in the length direction of the pole piece unit of the naked battery cell. And the tab can be matched with a connecting piece with at least two tab connecting parts for use. According to the invention, a series of problems caused by too many layers of tabs are avoided, and the problem that the number of the tabs exceeds the actual welding capability and cannot be welded due to too many layers of tabs is solved without increasing the number of the naked battery cells, so that a series of defects caused by increasing the number of the naked battery cells are avoided.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a connector, a battery cell, a battery, and a vehicle. Background Technology

[0002] With the development of battery technology, the requirements for battery integration and fast charging performance are getting higher and higher. To improve battery integration, there is a need to increase the size of the bare cell, which will lead to an increase in the number of electrode layers. In order to improve fast charging performance, there is a need to reduce the thickness of the electrode, which will also lead to an increase in the number of electrode layers. The increase in the number of electrode layers will largely increase the number of layers of a single tab.

[0003] Single tabs of the same polarity need to be gathered together and welded to form tabs. If there are too many layers of tabs, it will exceed the actual welding capacity and make it impossible to weld the tabs. In addition, a large number of layers of tabs also means that the space required for bending the tabs is larger, which affects the energy density of the battery. Furthermore, the more layers of tabs there are, the longer the extension length of the outermost tab relative to the electrode needs to be to gather together with other tabs of the same polarity. The longer the extension length of the tab relative to the electrode, the more tab material is used, and the more difficult the electrode stacking or winding process becomes.

[0004] Therefore, we are now facing a series of problems caused by an excessive number of tab layers. Related technologies address the issue of "tabs becoming unusable due to excessive welding capacity" by increasing the number of bare cells. In other words, when the number of tab layers in a single bare cell exceeds the actual welding capacity, multiple (usually two) bare cells are used, and their tabs are welded separately. While this solves the problem of "tabs becoming unusable due to excessive tab layers," it also increases the amount of negative electrode material and separator material used, and increases the overall thickness of the cell, affecting battery cost and space utilization. Clearly, this is not an ideal solution.

[0005] In view of this, it is urgent for those skilled in the art to provide a better solution to the series of problems caused by an excessive number of tab layers. Utility Model Content

[0006] To solve the above-mentioned technical problems, this application provides a connecting piece, the connecting piece including a main body and at least two electrode connecting parts, each of the electrode connecting parts being connected to the main body, wherein at least two of the electrode connecting parts are located on the same side of the main body, and the electrode connecting parts located on the same side of the main body are staggered from each other in the thickness direction of the connecting piece.

[0007] In one embodiment of the connecting piece, at least two electrode connecting portions are provided on the first side of the main body, and at least one electrode connecting portion is not provided or is provided on the side of the main body opposite to the first side.

[0008] In one embodiment of the connecting piece, at least one of the tab connecting portions is disposed flush with the main body portion in the thickness direction of the connecting piece.

[0009] In one embodiment of the connecting piece, at least two adjacent electrode connecting portions on the same side of the main body are spaced apart from each other. In another embodiment of the connecting piece, at least two adjacent electrode connecting portions are provided with a second connecting portion, which connects the two adjacent electrode connecting portions.

[0010] This application also provides a battery cell, the battery cell comprising at least one bare battery cell, the bare battery cell comprising an electrode unit, the at least one bare battery cell having at least two electrodes of the same polarity, the electrodes of the same polarity of the same bare battery cell being offset from each other in the length direction of the electrode unit of the bare battery cell.

[0011] In one embodiment of the battery cell, the battery cell includes polarity terminals and a connecting piece as described in any one of the claims, wherein each of the same polarity tabs of the same bare battery cell is electrically connected to the tab connection portion on the same side of the main body of the same connecting piece, and the main body is electrically connected to the polarity terminals of the same polarity.

[0012] In one embodiment of the battery cell, there are multiple bare battery cells, and the same polarity tabs of adjacent bare battery cells are electrically connected to the tab connection portions on both sides of the same connecting piece.

[0013] This application also provides a battery comprising the cells described in any of the preceding claims.

[0014] This application also provides a vehicle that includes the aforementioned battery.

[0015] The connecting piece provided in this application can be used with bare cells having at least two tabs of the same polarity because at least two tabs are located on the same side of the main body and the tabs on the same side of the main body are staggered in the thickness direction of the connecting piece.

[0016] The battery cell provided in this application has at least one bare cell with two or more tabs of the same polarity. Compared with a single bare cell having only one tab of the same polarity, the number of layers of a single tab is reduced, thus avoiding a series of problems caused by too many tab layers.

[0017] The battery and vehicle provided in this application also have the aforementioned technical effects because they include the aforementioned battery cells. Attached Figure Description

[0018] Figure 1 A schematic diagram of one embodiment of the connecting piece provided in this application;

[0019] Figure 2 for Figure 1 View from direction A;

[0020] Figure 3 for Figure 1 View from direction B;

[0021] Figure 4 A schematic diagram of another embodiment of the connecting piece provided in this application;

[0022] Figure 5 for Figure 4 The C-direction view;

[0023] Figure 6 A schematic diagram of another embodiment of the connecting piece provided in this application;

[0024] Figure 7 A schematic diagram of another embodiment of the connecting piece provided in this application;

[0025] Figure 8 This is a partial structural schematic diagram of one embodiment of the battery cell provided in this application;

[0026] Figure 9 for Figure 8 The D-direction view;

[0027] Figure 10 for Figure 8 E-view

[0028] Figure 11 for Figure 8 A schematic diagram before the connecting piece is bent;

[0029] Figure 12 A partial structural schematic diagram of another embodiment of the battery cell provided in this application;

[0030] Figure 13 A partial structural schematic diagram of another embodiment of the battery cell provided in this application;

[0031] Figure 14 This is a partial structural schematic diagram of one embodiment of the battery cell provided in this application;

[0032] Figure 15 A partial structural schematic diagram of another embodiment of the battery cell provided in this application;

[0033] Figure 16This is a partial structural schematic diagram of another embodiment of the battery cell provided in this application.

[0034] The annotations in the attached figures are explained as follows:

[0035] 1 Connecting piece, 11 Main body, 12 Electrode connecting part, 13 First connecting part, 14 Second connecting part;

[0036] 2-pole unit;

[0037] 3. Positive electrode ear;

[0038] 4. Negative electrode ear. Detailed Implementation

[0039] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] like Figures 1-7 As shown, the connecting piece 1 provided in this application includes a main body 11 and at least two (may be two or more) electrode connecting parts 12. Each electrode connecting part 12 is connected to the main body 11, wherein at least two electrode connecting parts 12 are located on the same side of the main body 11, and the electrode connecting parts 12 located on the same side of the main body 11 are staggered from each other in the thickness direction of the connecting piece 1. In the thickness direction of the connecting piece 1, the gap between two staggered electrode connecting parts 12 is greater than or equal to 0, preferably greater than 0, for connection. Figure 2 It is understood that the two tab connecting portions 12 located on the left side of the main body 11 are offset from each other in the thickness direction of the connecting piece 1, and the gap between the two tab connecting portions 12 is greater than 0. In use, the main body 11 is electrically connected to the polarity terminal of the battery cell, and each tab connecting portion 12 is electrically connected to one tab of the battery cell. That is to say, the connecting piece 1 acts as a transfer between the tab and the polarity terminal.

[0041] In some embodiments, such as Figures 1-3 As shown, at least two (or more) tab connecting portions 12 are provided on the first side of the main body 11, and no tab connecting portions 12 are provided on the side of the main body 11 opposite to the first side.

[0042] In some embodiments, such as Figures 4-5 As shown, at least two (or more) tab connecting portions 12 are provided on the first side of the main body 11, and at least two (or more) tab connecting portions 12 are provided on the side of the main body 11 opposite to the first side.

[0043] In some embodiments, such as Figure 6As shown, at least two (or more) tab connecting portions 12 are provided on the first side of the main body 11, and one tab connecting portion 12 is provided on the side of the main body 11 opposite to the first side.

[0044] In some embodiments, at least one tab connection portion 12 is flush with the main body portion 11 in the thickness direction of the connecting piece 1. If the thickness direction of the connecting piece 1 is considered as the vertical direction, then the upper surface of the tab connection portion 12 flush with the main body portion 11 is coplanar with the upper surface of the main body portion 11, and the lower surface of the tab connection portion 12 flush with the main body portion 11 is coplanar with the lower surface of the main body portion 11. This design is more conducive to improving the space utilization of the battery. For example... Figure 2 In the middle, one of the two tab connecting portions 12 located on the left side of the main body 11 is flush with the main body 11 in the thickness direction of the connecting piece 1. Figure 5 In the middle, one of the two electrode connecting parts 12 located on the left side of the main body 11 is flush with the main body 11, and one of the two electrode connecting parts 12 located on the right side of the main body 11 is flush with the main body 11 in the thickness direction of the connecting piece 1.

[0045] Alternatively, all tab connecting portions 12 may not be flush with the main body 11 in the thickness direction of the connecting piece 1. If the thickness direction of the connecting piece 1 is considered as the vertical direction, then specifically, all tab connecting portions 12 may be located above the main body 11, or all tab connecting portions 12 may be located below the main body 11, or some tab connecting portions 12 may be located above the main body 11 and some tab connecting portions 12 may be located below the main body 11. Figure 2 or Figure 5 As shown, the tab connection portion 12, which is not flush with the main body portion 11, can be connected to the main body portion 11 through the inclined first connection portion 13.

[0046] In some embodiments, such as Figures 1-6 As shown, at least two adjacent tab connecting portions 12 located on the same side of the main body 11 are spaced apart from each other. For example, if the side where the tab connecting portion 12 is located is considered as one side in the length direction of the main body 11, then in the width direction of the main body 11, the tab connecting portions 12 located on the same side of the main body 11 are arranged sequentially, with gaps formed between adjacent tab connecting portions 12. For example, Figure 6 In the middle, there is a gap between the two pole tab connecting parts 12 located on the left side of the main body part 11.

[0047] In some embodiments, such as Figure 7 As shown, a second connecting portion 14 is provided between at least two adjacent electrode connecting portions 12 located on the same side of the main body portion 11, so that at least two adjacent electrode connecting portions 12 are connected through the second connecting portion 14.

[0048] Specifically, if there are three or more tab connecting portions 12 on the same side of the main body 11, then all adjacent tab connecting portions 12 may be spaced apart from each other, some adjacent tab connecting portions 12 may be spaced apart from each other and some adjacent tab connecting portions 12 may be connected by a second connecting portion 14, or all adjacent tab connecting portions 12 may be connected by a second connecting portion 14.

[0049] In some embodiments, the connecting piece 1 is an integral structure.

[0050] The battery cells provided in this application include bare battery cells, such as... Figures 8-10 As shown, a bare battery cell has a positive tab 3, a negative tab 4, and an electrode unit 2. The number of bare battery cells is one, two, or more, wherein at least one bare battery cell has two or more tabs of the same polarity. Figure 8 The bare cell has two positive tabs 3 and two negative tabs 4. The tabs of the same polarity of the same bare cell are staggered in the length direction of the electrode unit 2. In addition, the tabs of the same polarity of the same bare cell are also staggered in the stacking direction of the electrode unit 2.

[0051] In related technologies, a single bare cell is equipped with only one tab of the same polarity, namely a positive tab 3 and a negative tab 4. With the increasing demand for battery integration and fast charging performance, the number of layers of the tab pieces is increasing, which leads to a series of problems: the tab pieces of the same polarity need to be gathered together and welded to form the tab. Too many layers of tab pieces will exceed the actual welding capacity and make it impossible to weld the tabs. In addition, the large number of layers of tab pieces also leads to a larger space required for bending the tabs, resulting in low utilization of the internal space of the battery and affecting the energy density of the battery. Furthermore, the more layers of tab pieces there are, the longer the extension length of the outermost tab piece relative to the electrode needs to be to be gathered together with other tab pieces of the same polarity. The longer the extension length of the tab piece relative to the electrode, the more tab material is used, and the greater the difficulty of the electrode stacking or winding process. In related technologies, the problem of "exceeding the actual welding capacity and thus being unable to weld the tabs" is solved by increasing the number of bare cells. However, this brings a series of drawbacks: increased use of negative electrode materials, separator materials, etc., increased overall cell thickness, and impact on battery cost and space utilization.

[0052] The battery cell provided in this application has two or more tabs of the same polarity in the same bare cell. Compared with a single bare cell having only one tab of the same polarity, the number of layers in a single tab is reduced, thus avoiding the series of problems caused by too many tab layers. For example, the total number of layers of the positive tab 3 is 10. When only one positive tab 3 is provided, the number of layers in a single positive tab 3 is 10. When two positive tabs 3 are provided and the number of layers in the two positive tabs 3 is the same, the number of layers in a single positive tab 3 is 5. This application reduces the number of tab layers by having two or more tabs of the same polarity in the same bare cell. Therefore, the problem of being unable to weld due to excessive tab layers is avoided. Thus, it is not necessary to increase the number of bare cells to solve the problem of excessive tab layers exceeding the actual welding capacity. Therefore, the aforementioned series of drawbacks caused by increasing the number of bare cells are avoided.

[0053] The connecting piece 1 provided in this application can be used with bare cells having two or more electrodes of the same polarity because at least two tab connecting portions 12 are located on the same side of the main body 11, and the tab connecting portions 12 located on the same side of the main body 11 are staggered in the thickness direction of the connecting piece 1.

[0054] When used together, the battery cell includes the connecting piece 1 provided in this application. Each tab of the same polarity of the same bare battery cell is electrically connected to the corresponding tab connection portion 12 on the same side of the connecting piece 1. The main body 11 of the connecting piece 1 is electrically connected to the polarity terminal of the battery cell. Specifically, the electrical connection methods include, but are not limited to, welding, riveting, and conductive adhesive bonding.

[0055] Alternatively, the tabs of the same polarity in the same bare cell can be electrically connected to the polarity terminal through multiple independent conventional connecting pieces.

[0056] When connecting the tab connection part 12 of the connecting piece 1 to the tab of the bare battery cell, such as Figure 11 As shown, the main body 11 and the electrode connecting part 12 of the connecting piece 1 are both aligned with the stacking direction of the electrode unit 2 (i.e., Figure 11 (The direction perpendicular to the paper plane) is basically perpendicular. After the tab connection part 12 of the connecting piece 1 is connected to the tab of the bare cell, it is necessary to continue along... Figure 11 The dotted line bends the main body 11 of the connecting piece 1. After bending, as shown... Figure 8 As shown, the stacking direction of the main body 11 and the electrode unit 2 (i.e., Figure 8 The direction perpendicular to the paper plane is basically parallel, and the stacking direction of the tab connection 12 and the electrode unit 2 is basically parallel. Figure 8The direction perpendicular to the paper is basically perpendicular. That is to say, during assembly, first connect the tab connection part 12 of the connecting piece 1 to the tab of the bare cell, and then bend the main body part 11 of the connecting piece 1. When bending the main body part 11, the tab connection part 12 will inevitably be pulled, causing the tab connection part 12 to deform slightly. However, since the tab connection part 12 is already connected to the tab of the bare cell when the main body part 11 is bent, even if the tab connection part 12 is slightly deformed, it will not affect its connection with the tab.

[0057] In some embodiments, the battery cell includes a housing, polarity terminals are disposed on the housing, and the bare battery cell is located inside the housing. The bare battery cell and the housing are insulated. The insulation method is not limited; for example, an insulating film can be used. The electrode unit 2 of the battery cell includes a positive electrode, a separator, and a negative electrode. A single tab of the battery cell includes one or more tab sheets, and the tab sheets of the same tab are gathered together and welded together. The tab sheet is electrically connected to the current collector of the electrode sheet of the same polarity, and the electrical connection method includes, but is not limited to, welding, integral assembly, etc.

[0058] In some embodiments, the electrode unit 2 of the battery cell is a wound structure. Before winding, the positive electrode and the negative electrode are stacked layer by layer through a separator to form a long strip-shaped stacked unit, and then the stacked unit is wound along the length direction.

[0059] In some embodiments, the electrode unit 2 of the battery cell has a stacked structure, which is formed by stacking several positive electrode plates and several negative electrode plates layer by layer with a separator in between. Specifically, the separator can be stacked layer by layer or stacked in a Z-shape.

[0060] In some embodiments, such as Figure 12 As shown, the number of tabs of both polarities in the same bare cell is two or more. That is to say, the number of positive tabs 3 is two or more, and the number of negative tabs 4 is also two or more.

[0061] In some embodiments, such as Figure 13 As shown, the number of tabs of one polarity in the same bare cell is two or more, and the number of tabs of the other polarity is one. Specifically, the number of positive tabs 3 can be two or more, and the number of negative tabs 4 can be one, or the number of negative tabs 4 can be two or more, and the number of positive tabs 3 can be one.

[0062] In some embodiments, such as Figure 8 As shown, the two polarities of the same bare cell are located on the same side of the electrode unit 2.

[0063] In some embodiments, the positive tab 3 of the same bare cell is located on one side of the electrode unit 2, and the negative tab 4 is located on the other side of the electrode unit 2, for example, Figure 12In the middle, the positive electrode 3 and the negative electrode 4 are located on opposite sides of the electrode unit 2.

[0064] In some embodiments, such as Figure 14 As shown, the battery cell has two or more bare cells, and the terminals of adjacent bare cells with the same polarity are respectively connected to the tab connection parts 12 on both sides of the same connecting piece 1.

[0065] In some embodiments, such as Figure 15 As shown, the battery cell has two or more bare cells. One type of terminal of adjacent bare cells with the same polarity is connected to the tab connection portion 12 on both sides of the same connecting piece 1, and the other type of terminal of adjacent bare cells with the same polarity is connected to different connecting pieces 1.

[0066] In some embodiments, such as Figure 16 As shown, the battery cell has two or more bare cells, some of which have two or more tabs of the same polarity, while some of which have only one tab of the same polarity, i.e., one positive tab 3 and one negative tab 4.

[0067] The battery provided in this application includes the aforementioned battery cells. Furthermore, it may also include a housing, with multiple battery cells arranged inside the housing to form a cell pack.

[0068] The vehicle provided in this application includes the aforementioned battery, and the vehicle may be a pure electric vehicle or a hybrid vehicle.

[0069] The above embodiments can be freely combined without conflict.

[0070] It should be understood that the phrase "some embodiments" throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "some embodiments" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0071] The above examples illustrate the principles and implementation methods of this application. The descriptions of the embodiments are merely for the purpose of helping to understand the methods and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A connecting piece, characterized in that, The connecting piece (1) includes a main body (11) and at least two tab connecting parts (12), each of the tab connecting parts (12) being connected to the main body (11). At least two of the tab connecting parts (12) are located on the same side of the main body (11), and the tab connecting parts (12) located on the same side of the main body (11) are staggered from each other in the thickness direction of the connecting piece (1).

2. The connecting piece according to claim 1, characterized in that, The first side of the main body (11) is provided with at least two electrode connecting parts (12), and the side of the main body (11) opposite to the first side is not provided or is provided with at least one electrode connecting part (12).

3. The connecting piece (1) according to claim 1, characterized in that, At least one of the tab connecting portions (12) and the main body portion (11) are disposed flush with each other in the thickness direction of the connecting piece (1).

4. The connecting piece (1) according to claim 1, characterized in that, Among all the tab connecting portions (12) on the same side of the main body portion (11), at least two adjacent tab connecting portions (12) are spaced apart from each other.

5. The connecting piece (1) according to claim 1, characterized in that, Among all the electrode connecting parts (12) on the same side of the main body (11), at least two adjacent electrode connecting parts (12) are provided with a second connecting part (14) so ​​that at least two adjacent electrode connecting parts (12) are connected through the second connecting part (14).

6. A battery cell, characterized in that, The battery cell includes at least one bare battery cell, the bare battery cell includes an electrode unit (2), at least one of the bare battery cells is provided with at least two electrodes of the same polarity, and the electrodes of the same polarity of the same bare battery cell are staggered from each other in the length direction of the electrode unit (2) of the bare battery cell.

7. The battery cell according to claim 6, characterized in that, The battery cell includes polarity terminals and a connecting piece (1) as described in any one of claims 1-5. Each electrode tab of the same polarity of the same bare battery cell is electrically connected to the electrode tab connecting part (12) on the same side of the main body part (11) of the same connecting piece (1). The main body part (11) is electrically connected to the polarity terminals of the same polarity.

8. The battery cell according to claim 7, characterized in that, The number of bare cells is multiple, and the same polarity tabs of adjacent bare cells are electrically connected to the tab connection portions (12) on both sides of the same connecting piece (1) in a one-to-one correspondence.

9. A battery, characterized in that, The battery comprises the cell according to any one of claims 6-8.

10. A vehicle, characterized in that, The vehicle includes the battery as described in claim 9.

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