Adapter sheet for battery cell, top cover and battery cell

Abstract

The utility model provides an adapter piece for a battery cell, a top cover and the battery cell, the battery cell comprises an electrode assembly and a tab extending outwards from the top surface of the electrode assembly, the adapter piece comprises an adapter piece body and a connecting part located on the adapter piece body, the connecting part extends in the direction away from the adapter piece body, and the connecting part is located on the adapter piece body and extends in the direction away from the adapter piece body. The extension direction of the connecting part is parallel to the extension direction of the tab, and when the tab is connected with the adapter plate, the tab does not need to be bent, and only the parallel tab and the connecting part need to be directly welded, so that the tab can be directly connected with the adapter plate without being bent, the tab can be prevented from being split and inserted inwards, and the connection of the tab and the adapter plate is facilitated. And a reserved space does not need to be provided for bending of the tabs, so that the space utilization rate of the battery cell can be improved, and the energy density of the battery cell is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an adapter plate, a top cover and an electric core for an electric core. Background Art

[0002] Lithium-ion batteries have the advantages of high energy density, small self-discharge and long cycle life, so they have been widely used in the fields of electronics, electric vehicles and energy storage. The adapter plate is one of the indispensable important components in lithium-ion batteries. The electrode assembly in the electric core is connected to the pole column through the adapter plate. However, when the existing adapter plate is connected to the electrode assembly, the ear of the electrode assembly must be bent before it can be connected to the adapter plate. However, the ear is easily split when bent, and in severe cases, the ear is inserted into the pole piece, resulting in insufficient safety performance of the battery. Summary of the Utility Model

[0003] In view of this, the purpose of the present utility model is to provide an adapter plate, a top cover and an electric core for an electric core to solve the problem that the bending of the ear easily causes insufficient safety performance of the battery.

[0004] Based on the above purpose, the first aspect of the present utility model provides an adapter plate for an electric core. The electric core includes an electrode assembly and an ear extending outward from the top surface of the electrode assembly. The adapter plate includes an adapter plate body and a connecting portion located on the adapter plate body. The connecting portion extends in a direction away from the adapter plate body, and the extending direction of the connecting portion is parallel to the extending direction of the ear.

[0005] Optionally, the ear includes a welding end away from the top surface, and the connecting portion is connected to a side of the welding end close to the connecting portion.

[0006] Optionally, the connecting portion includes two opposite first surfaces for connecting with the welding end, and the orthographic projection of the welding end on the plane where the first surface is located at least partially coincides with the first surface.

[0007] Optionally, the orthographic projection of the welding end on the plane where the first surface is located is entirely located within the first surface.

[0008] Optionally, the plane where the adapter plate body is located is parallel to the top surface of the electrode assembly, and the connecting portion is perpendicular to the adapter plate body.

[0009] Optionally, the thickness of the connecting portion is greater than the thickness of the adapter plate body, and the thickness direction is parallel to the extending direction of the connecting portion.

[0010] Optionally, the size of the orthographic projection of the connecting portion on the adapter sheet body is greater than a preset value; and / or the adapter sheet body includes two opposite side surfaces arranged along the length direction of the adapter sheet body, and the area of the side surface is greater than the preset value;

[0011] Wherein, the preset value is calculated according to the formula E max / (V min *τ), where E max is the maximum charge and discharge energy of the battery cell; V min is the lower limit of the battery cell voltage; and τ is the current-carrying capacity of the adapter sheet.

[0012] Optionally, the adapter sheet body includes a welding mark area and a non-welding mark area, and the connecting portion is arranged in the non-welding mark area.

[0013] The present application also provides a top cover for a battery cell, including a top cover body and two adapter sheets as described in any one of the above first aspects spaced apart on the top cover body, and the adapter sheet body of each adapter sheet is arranged on the top cover.

[0014] The present application also provides a battery cell, which includes an electrode assembly and the top cover as described in the above second aspect. The top surface of the electrode assembly extends outward to form a first tab and a second tab. The first tab is connected to the connecting portion of one of the adapter sheets on the top cover, and the second tab is connected to the connecting portion of the other adapter sheet on the top cover.

[0015] As can be seen from the above, for the adapter sheet, top cover and battery cell provided by the present utility model, the adapter sheet includes an adapter sheet body and a connecting portion located on the adapter sheet body. The connecting portion extends in a direction away from the adapter sheet body, and the extending direction of the connecting portion is parallel to the extending direction of the tab. When connecting the tab and the adapter sheet, there is no need to bend the tab, and only the parallel tab and the connecting portion need to be directly welded. In this way, the tab can be directly connected to the adapter sheet without bending, which can avoid tab splitting and internal insertion, and there is no need to provide a reserved space for bending the tab, thereby improving the space utilization rate of the battery cell and further increasing the energy density of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is the first schematic diagram of the battery cell shown in the embodiment of the present application;

[0018] Figure 2 It is a top view of the adapter plate shown in the embodiment of the present application;

[0019] Figure 3 It is a front view of the adapter plate shown in the embodiment of the present application;

[0020] Figure 4 It is a schematic diagram of the assembly of the battery cell and the adapter plate shown in the embodiment of the present application;

[0021] Figure 5 It is another top view of the adapter plate shown in the embodiment of the present application;

[0022] Figure 6 It is another front view of the adapter plate shown in the embodiment of the present application;

[0023] Figure 7 It is a bottom view of the top cover shown in the embodiment of the present application;

[0024] Figure 8 It is a second structural schematic diagram of the battery cell shown in the embodiment of the present application;

[0025] Figure 9 It is a third structural schematic diagram of the battery cell shown in the embodiment of the present application;

[0026] Figure 10 It is a sectional view of the third structure of the battery cell shown in the embodiment of the present application in the B-B direction.

[0027] In the figure, 1. Adapter plate; 11. Adapter plate body; 111. Welding mark area; 112. Non-welding mark area; 113. Side surface; 12. Connection part; 121. First surface; 2. Battery cell; 21. Electrode assembly; 22. Tab; 221. First tab; 222. Second tab; 223. Welding end; 224. Fixed end; 23. Top cover; 231. Top cover body. Detailed implementation manners

[0028] In order to make the purpose, technical solutions and advantages of the present utility model clearer and more understandable, the following further describes the present utility model in detail with reference to specific embodiments and the accompanying drawings.

[0029] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present utility model should have the ordinary meanings understood by those with general skills in the field to which this application belongs. The "first", "second" and similar terms used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0030] Lithium-ion batteries have the advantages of high energy density, low self-discharge, and long cycle life, so they have been widely used in the fields of electronics, electric vehicles, and energy storage. The adapter plate is one of the indispensable important components in lithium-ion batteries. The electrode assembly in the battery cell is connected to the pole column through the adapter plate.

[0031] The currently used adapter plate is usually a planar structure perpendicular to the tab of the electrode assembly. When the electrode assembly is connected to the adapter plate, the tab of the electrode assembly needs to be bent first so that the tab can be connected to the planar adapter plate. This way of bending the tab to achieve the connection between the electrode assembly and the adapter plate, on the one hand, is very likely to cause the tab to split during bending, and in severe cases, the tab may be inserted into the electrode plate, causing a short circuit and resulting in insufficient safety performance of the battery; on the other hand, this connection method usually requires a large space reserved for tab bending during the battery assembly process, resulting in ineffective utilization of the battery space and reducing its energy density.

[0032] Therefore, if a connection method that does not require bending the tab to connect to the adapter plate can be provided, it can avoid tab splitting and insertion, and can also improve the space utilization rate of the battery, thereby increasing the energy density of the battery.

[0033] Based on this, the present application provides an adapter plate for a battery cell. Figure 1 The first schematic diagram of the battery cell is shown, as Figure 1 shown, the battery cell 2 includes an electrode assembly 21 and tabs 22 extending outward from the top surface of the electrode assembly 21. The electrode assembly 21 includes a stacked or wound positive electrode plate, a separator, and a negative electrode plate. The tabs 22 include a positive tab and a negative tab. The positive tab is formed by extending outward from one end of the positive electrode plate, and the negative tab is formed by extending outward from one end of the negative electrode plate.

[0034] Figure 2 The top view of the adapter piece 1 is shown, Figure 3 The front view of the adapter piece 1 is shown. Refer to Figure 1 and Figure 2 As shown, the adapter piece 1 includes an adapter piece body 11 and a connecting portion 12 located on the adapter piece body 11. The connecting portion 12 extends in a direction away from the adapter piece body 11, and the extending direction of the connecting portion 12 is parallel to the extending direction of the tab 22.

[0035] Specifically, during specific assembly, the adapter piece body 11 is connected to the top cover 23 of the battery cell 2, and the adapter piece body 11 is parallel to the plane where the top cover 23 of the battery cell 2 is located. The connecting portion 12 extends in a direction away from the adapter piece body 11, and the extending direction of the connecting portion 12 is parallel to the extending direction of the tab 22. In this way, when connecting the tab 22 to the adapter piece 1, there is no need to bend the tab 22, and only the parallel tab 22 and the connecting portion 12 need to be directly welded. In this way, the tab 22 can be directly connected to the adapter piece 1 without bending, which can avoid the splitting and internal insertion of the tab 22, and there is no need to provide a reserved space for the bending of the tab 22, which can improve the space utilization rate of the battery cell 2 and thus improve the energy density of the battery cell 2.

[0036] In some embodiments, Figure 4 The schematic diagram after the assembly of the battery cell 2 and the adapter piece 1 is shown. As Figure 4 shown, the battery cell 2 includes two tabs 22, namely a positive tab and a negative tab. At this time, there are also two adapter pieces 1, and each adapter piece 1 corresponds to one tab 22. The tab 22 includes a fixed end 224 connected to the top surface of the electrode assembly 21 and a welding end 223 away from the top surface.

[0037] In some embodiments, the connecting portion 12 is connected to the welding end 223 of the tab 22. Specifically, the connecting portion 12 is connected to the side of the welding end 223 close to the connecting portion 12. In this way, it is very convenient for the welding process of the connecting portion 12 and the tab 22, and the assembly time of the battery cell 2 is reduced.

[0038] Continue to refer to Figure 2 and Figure 3 , the connecting portion 12 includes two first surfaces 121 arranged oppositely. The first surfaces 121 are used to connect to the welding end 223, and the orthographic projection of the welding end 223 on the plane where the first surfaces 121 are located at least partially coincides with the first surfaces 121.

[0039] Specifically, the orthographic projection of the welding end 223 on the plane where the first surface 121 is located coincides with the first surface 121 at least partially, that is, the overlapping part of the orthographic projection of the welding end 223 on the plane where the first surface 121 is located and the first surface 121 does not overlap, or the orthographic projection of the welding end 223 on the plane where the first surface 121 is located completely coincides with the first surface 121, or the orthographic projection of the welding end 223 on the plane where the first surface 121 is located is entirely within the first surface 121, and the first surface 121 completely covers the orthographic projection of the welding end 223.

[0040] The orthographic projection of the welding end 223 on the plane where the first surface 121 is located coincides with the first surface 121 at least partially, so that during actual welding, the area on the connecting part 12 that coincides with the projection of the welding end 223 can be directly welded to the welding end 223 without adjusting or twisting the position of the tab 22, ensuring that the tab 22 will not fork or be inserted internally, thereby improving the safety performance of the battery cell 2, and at the same time, it can also enhance the convenience of welding the tab 22 to the adapter plate 1.

[0041] Furthermore, the orthographic projection of the welding end 223 on the plane where the first surface 121 is located is entirely within the first surface 121. In this way, during actual welding, the connecting part 12 can be directly welded to the entire welding end 223 of the tab 22, further enhancing the connection firmness between the tab 22 and the adapter plate 1.

[0042] In some embodiments, the plane where the adapter plate body 11 is located is parallel to the top surface of the electrode assembly 21, and the connecting part 12 is perpendicular to the adapter plate body 11.

[0043] Specifically, the connecting part 12 is perpendicular to the adapter plate body 11, that is, the connecting part 12 is perpendicular to the top surface of the electrode assembly 21. This is because, generally speaking, the tab 22 extends vertically from the top surface of the electrode assembly 21. When the connecting part 12 is also perpendicular to the top surface of the electrode assembly 21, the setting directions of the tab 22 and the connecting part 12 are the same, which is more conducive to welding the tab 22 to the connecting part 12.

[0044] In some embodiments, continue to refer to Figure 3 as shown, the thickness of the connecting part 12 is greater than the thickness of the adapter plate body 11, and the thickness direction (such as Figure 3 the direction shown by A) is parallel to the extending direction of the connecting part 12.

[0045] Specifically, the thickness of the connecting portion 12 is relatively large, such that the area of the connecting portion 12 available for connection with the tab 22 is larger, facilitating the stable connection of the tab 22. The thickness of the adapter plate body 11 is relatively small, which can, without reducing the thickness of the connecting plate, minimize the thickness of the entire adapter plate 1 as much as possible, thereby reducing the space occupied by the assembled adapter plate 1 and further increasing the energy density of the entire battery cell 2.

[0046] Figure 5 Fig. shows another top view of the adapter plate 1. Figure 6 Fig. shows another front view of the adapter plate 1. As Figure 5 and Figure 6 shown, in some embodiments, the size of the orthographic projection of the connecting portion 12 on the adapter plate body 11 is greater than a preset value; and / or the adapter plate body 11 includes two opposite side surfaces 113 arranged along the length direction of the adapter plate body 11, and the area of the side surfaces 113 is greater than a preset value.

[0047] Wherein, the preset value is calculated according to the formula E max / ( Vmin *τ), where E max is the maximum charge-discharge energy of the battery cell 2, with the unit of Wh; V min is the lower limit of the voltage of the battery cell 2, with the unit of V; τ is the current-carrying capacity of the adapter plate 1, the current-carrying capacity of the adapter plate 1.

[0048] Specifically, the orthographic projection of the connecting portion 12 on the adapter plate body 11 is the surface area of the surface where the connecting portion 12 is connected to the top surface of the electrode assembly 21. The size of the orthographic projection of the connecting portion 12 on the adapter plate body 11 being greater than a preset value means that the surface area of the surface where the connecting portion 12 is connected to the top surface of the electrode assembly 21 is greater than a preset value. This surface area can be calculated by multiplying the length of the connecting portion 12 (i.e., Figure 6 shown as a in Figure 5 ) by the width (i.e., max shown as c in min ), that is, a*c > E

[0049] The adapter plate body 11 includes two opposite side surfaces 113 arranged along the length direction of the adapter plate body 11. The side surfaces 113 are parallel to the extending direction of the connecting portion 12, and the area of the side surfaces 113 is greater than a preset value.

[0050] Specifically, the area of the side surface 113 can be calculated by multiplying the length of the side surface 113 (i.e., Figure 5 shown as d in Figure 6 ) by the width of the side surface 113 (i.e., max shown as e in min ), that is, d*e > E

[0051] Since the current flowing through the adapter piece 1 is very large during the use of the battery, the large current will generate a large amount of heat, which may also reduce the service life of the adapter piece 1 and increase the heat dissipation difficulty of the entire battery cell 2. In this application, E max / (V min *τ) is used to calculate a preset value, and it is controlled that the surface area of the surface where the connecting portion 12 is connected to the top surface of the electrode assembly 21 is greater than this preset value, and / or the side surface area 113 of the adapter piece body 11 is greater than this preset value, which can reduce the heat generation amount when the current passes through the adapter piece 1 and improve the service life of the adapter piece 1.

[0052] In some embodiments, the adapter piece body 11 includes a welding mark area 111 and a non-welding mark area 112. The welding mark area 111 is the laser welding mark area when the adapter piece 1 is laser welded, and the connecting portion 12 is arranged in the non-welding mark area 112. The connecting portion 12 cannot be arranged in the laser welding mark area, otherwise the laser welding will have an adverse effect on the connection between the connecting portion 12 and the tab 22.

[0053] This application also provides a top cover 23 for the battery cell 2, Figure 7 showing a bottom view of the top cover 23 for the battery cell 2. As Figure 7 shown, the top cover 23 includes a top cover body 231 and two adapter pieces 1 of any of the above embodiments arranged at intervals on the top cover body 231. The adapter piece body 11 of each adapter piece 1 is arranged on the top cover 23.

[0054] This application also provides a battery cell 2, Figure 8 showing a second structural schematic diagram of the battery cell 2. In the figure, the lower plastic arranged at the edge of the top cover body 231 is omitted to expose the tab 22 and the adapter piece 1. As Figure 8 shown, the battery cell 2 includes an electrode assembly 21 and the top cover 23 of any of the above embodiments. The top surface of the electrode assembly 21 extends outwards to form a first tab 221 and a second tab 222. The first tab 221 is connected to the connecting portion 12 of one of the adapter pieces 1 on the top cover 23, and the second tab 222 is connected to the connecting portion 12 of the other adapter piece 1 on the top cover 23. In this way, the connection between the two adapter pieces 1 and the two tabs 22 on one electrode assembly 21 is realized, and when the tab 22 is welded to the adapter piece 1, there is no need to bend the tab 22, and only the tab 22 needs to be directly welded to the connecting portion 12. In this way, the tab 22 can be directly connected to the adapter piece 1 without bending, which can avoid the tab 22 from splitting and being inserted internally, and there is no need to provide a reserved space for the bending of the tab 22, which can improve the space utilization rate of the battery cell 2 and further improve the energy density of the battery cell 2.

[0055] Figure 9 showing a third structural schematic diagram of the battery cell 2. In the figure, the lower plastic arranged at the edge of the top cover body 231 is not omitted. Figure 10shows Figure 9 a cross-sectional view of the battery cell in the B-B direction. As Figure 9 and Figure 10 shown, the battery cell 2 includes two electrode assemblies 21. Two first tabs 221 of the two electrode assemblies 21 (exemplarily, two positive tabs of the two electrode assemblies 21) are both connected to the connecting portion 12 of a transfer piece 1 on the top cover 23. Two second tabs 222 of the two electrode assemblies 21 (exemplarily, two negative tabs of the two electrode assemblies 21) are both connected to the connecting portion 12 of another transfer piece 1 on the top cover 23. In this way, the connection between the two transfer pieces 1 and the four tabs 22 on the two electrode assemblies 21 is realized. And when welding the tab 22 to the transfer piece 1, there is no need to bend the tab 22, and only the tab 22 needs to be directly welded to the connecting portion 12. In this way, the tab 22 can be directly connected to the transfer piece 1 without bending, which can avoid the splitting and internal insertion of the tab 22, and there is no need to provide a reserved space for the bending of the tab 22, which can improve the space utilization rate of the battery cell 2, and further improve the energy density of the battery cell 2.

[0056] The transfer piece 1, the top cover 23 and the battery cell 2 provided by the present utility model for the battery cell 2. The transfer piece 1 includes a transfer piece body 11 and a connecting portion 12 located on the transfer piece body 11. The connecting portion 12 extends in a direction away from the transfer piece body 11, and the extending direction of the connecting portion 12 is parallel to the extending direction of the tab 22. When connecting the tab 22 to the transfer piece 1, there is no need to bend the tab 22, and only the parallel tab 22 needs to be directly welded to the connecting portion 12. In this way, the tab 22 can be directly connected to the transfer piece 1 without bending, which can avoid the splitting and internal insertion of the tab 22, and there is no need to provide a reserved space for the bending of the tab 22, which can improve the space utilization rate of the battery cell 2, and further improve the energy density of the battery cell 2.

[0057] Those of ordinary skill in the art should understand that: the discussion of any embodiment above is only exemplary, and is not intended to imply that the scope of the present application (including the claims) is limited to these examples; under the idea of the present utility model, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present utility model as above, which are not provided in detail for the sake of brevity.

[0058] The embodiments of the present utility model are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A transfer sheet for a battery cell, the battery cell comprising an electrode assembly and a tab extending outward from a top surface of the electrode assembly, characterized in that: The adapter plate includes an adapter plate body and a connecting portion located on the adapter plate body, the connecting portion extends in a direction away from the adapter plate body, and the extending direction of the connecting portion is parallel to the extending direction of the tab.

2. The adapter according to claim 1, characterized in that: The electrode tab includes a welding end away from the top surface, and the connecting portion is connected to a side of the welding end close to the connecting portion.

3. The adapter according to claim 2, characterized in that: The connecting portion includes two first surfaces arranged opposite to each other, the first surfaces are used to connect with the welding end, and the orthographic projection of the welding end on the plane where the first surfaces are located at least partially overlaps with the first surface.

4. The adapter according to claim 3, characterized in that: The orthographic projections of the welding ends on the plane where the first surface is located are all located within the first surface.

5. The adapter according to claim 1, characterized in that: The plane where the adapter body is located is parallel to the top surface of the electrode assembly, and the connecting portion is arranged perpendicular to the adapter body.

6. The adapter according to claim 5, characterized in that: The thickness of the connecting portion is greater than the thickness of the adapter plate body, and the thickness direction is parallel to the extending direction of the connecting portion.

7. The adapter according to claim 1, characterized in that: The size of the orthographic projection of the connecting portion on the adapter body is greater than a preset value; and / or the adapter body includes two side surfaces that are arranged opposite to each other, the two side surfaces are arranged along the length direction of the adapter body, and the area of ​​the side surfaces is greater than the preset value; Wherein, the preset value is according to formula E max / (V min *τ) is calculated, E max V is the maximum charge and discharge energy of the battery cell; min is the lower limit of the cell voltage; τ is the overcurrent capacity of the adapter.

8. The adapter according to claim 1, characterized in that: The adapter plate body includes a weld print area and a non-weld print area, and the connecting portion is arranged in the non-weld print area.

9. A top cover for a battery cell, characterized in that: It comprises a top cover body and two adapter plates according to any one of claims 1 to 8 which are arranged on the top cover body at intervals, and the adapter plate body of each adapter plate is arranged on the top cover.

10. A battery cell, characterized in that: The battery cell includes an electrode assembly and the top cover as described in claim 9, and a first pole ear and a second pole ear extend outward from the top surface of the electrode assembly, the first pole ear is connected to the connecting portion of one of the adapter plates on the top cover, and the second pole ear is connected to the connecting portion of another adapter plate on the top cover.

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