Connecting sheet, cover plate assembly and battery cell

Abstract

The utility model provides a connecting piece, cover plate subassembly and battery cell, the connecting piece includes: connecting body, connecting body in the thickness direction of connecting body, connecting body has opposite first surface and second surface, connecting body is used for attaching to the end portion of core package, the first surface faces the core package, and the second surface faces the core package. The connecting body is further provided with a first side face and a second side face which are connected and located between the first surface and the second surface, and a reinforcing convex rib is arranged on the connecting body, protrudes out of the first surface and is used for being contained in the containing space. The tab connecting part is connected with the first side surface, the tab connecting part is bent relative to the connecting body and protrudes out of the second surface, and the tab connecting part is used for connecting a tab; and the pole connecting part is connected with the second side surface, and the pole connecting part is bent relative to the connecting body and protrudes out of the first surface. According to the invention, the reinforcing convex rib is arranged in the accommodating space between the two core packages, so that the spare space in the shell can be fully utilized.

Description

Technical Field

[0001] This utility model relates to the field of battery cell technology, specifically to a connecting piece, a cover plate assembly, and a battery cell. Background Technology

[0002] With the development of the new energy industry, various fields are placing increasingly higher demands on the performance of power battery cells, such as high energy density, high-rate fast charging, 800V high-voltage charging, and high safety. Therefore, structural optimization is needed to adapt to the requirements of thin and long battery cell structures, improving current carrying capacity while ensuring safety performance to meet market demands. To improve the energy density of lithium-ion battery cells, connecting tabs can be led out from the top cover assembly. After the connecting tabs are assembled and connected to the tabs of the cell package, they are bent and flattened before being inserted into the casing for assembly, reducing the internal space occupied by the connecting tabs. However, this connecting tab still cannot fully utilize the structural space. Under the same material thickness conditions, the current carrying capacity and structural strength of the connecting tabs are poor, failing to meet the high current carrying capacity and assembly requirements of thin and long battery cells. Utility Model Content

[0003] The embodiments of this utility model provide a connecting piece, a cover plate assembly, and a battery cell, which can improve the technical problem of the connecting piece occupying a large space.

[0004] In a first aspect, embodiments of the present invention provide a connecting piece applied in a battery cell, the battery cell comprising a plurality of core packages arranged sequentially along a first direction, each core package having a tab at its end, the ends of two adjacent core packages being separated and defining a receiving space, the connecting piece comprising:

[0005] The connecting body has a first surface and a second surface facing away from each other in the thickness direction. The connecting body is used to be attached to the end of the core package and the first surface faces the core package. The connecting body also has a first side surface and a second side surface connected and located between the first surface and the second surface. The connecting body is provided with a reinforcing rib. The reinforcing rib protrudes from the first surface and is used to be received in the receiving space.

[0006] The electrode connecting part is connected to the first side surface. The electrode connecting part is bent relative to the connecting body and protrudes from the second surface. The electrode connecting part is used to connect the electrode.

[0007] The pole connection portion is connected to the second side surface, and the pole connection portion is bent relative to the connection body and protrudes from the first surface.

[0008] In one embodiment, along the thickness direction of the connecting body, the height of the reinforcing rib protruding from the first surface is 0.5 to 1.5 times the thickness of the connecting piece; and / or

[0009] The reinforcing rib extends along the length of the connecting body, and the length of the reinforcing rib is 30% to 90% of the length of the connecting piece. The length direction of the connecting body is from the second side to the third side, and the third side is the side of the connecting body opposite to the second side.

[0010] In one embodiment, the length of the tab connection portion extending outward from the first side is 8mm-12mm.

[0011] In one embodiment, the root of the tab connector is bent, and the surface of the root of the tab connector near the connector body is recessed to form a bending groove, the depth of which is 25% to 75% of the thickness of the tab connector.

[0012] In one embodiment, the bending groove is provided with at least one through hole penetrating the root of the tab connection portion, and the total length of all the through holes is 20% to 70% of the length of the bending groove.

[0013] In one embodiment, the cross-sectional area of ​​the connection between the electrode connector and the connecting body is S1, the area of ​​the minimum cross-section of the connecting body is S2, the electrode connector is provided with a fusible hole, and the area of ​​the minimum cross-section of the electrode connector through the fusible hole is S3. S1, S2 and S3 satisfy: 2S1>S2>S3.

[0014] In one embodiment, the pole connection portion is provided with a pole mounting hole, the pole mounting hole is a stepped hole, the depth of the step of the stepped hole is 25% to 75% of the total depth of the stepped hole, and the width of the step of the stepped hole is 0.5mm to 2mm.

[0015] Secondly, embodiments of this utility model provide a cover plate assembly, including a cover plate body, an electrode post passing through the cover plate body, and the aforementioned connecting piece, wherein the electrode post connecting portion is connected to the electrode post.

[0016] In one embodiment, the surface of the electrode post facing the electrode post connection portion is recessed to form a first groove extending along the height direction of the electrode post, and the height of the electrode post is at least 3 mm greater than the depth of the first groove; and / or

[0017] A pole mounting hole is provided on the pole connection part. When the pole mounting hole is a stepped hole, a second groove is provided on the periphery of the end of the pole facing the pole connection part, which is adapted to the step of the stepped hole.

[0018] In one embodiment, the cover plate assembly further includes a plastic part and a pressure ring both sleeved on the pole post. The pole post connecting portion is disposed at one axial end of the pole post, and the pressure ring is disposed at the other axial end of the pole post. The plastic part is located between the pressure ring and the pole post connecting portion. The pole post has a first segment corresponding to the plastic part and a second segment corresponding to the pressure ring. The diameter of the first segment is 0.4 mm to 1.0 mm larger than the diameter of the second segment.

[0019] Thirdly, embodiments of this utility model provide a battery cell, including a core pack and the aforementioned cover plate assembly. A tab is provided at the end of the core pack. There are multiple core packs, all of which are arranged sequentially along a first direction. The ends of two adjacent core packs are separated and define a receiving space. A connecting body is attached to the end of the core pack with its first surface facing the core pack. The tab is connected to the tab connecting portion, and the reinforcing rib is disposed within the receiving space.

[0020] In one embodiment, the battery cell further includes a housing that covers the cover plate body. The core package is disposed within the housing. The tabs disposed on the same ends of all the core packages have the same polarity. The connecting body also has a third side opposite to the second side. Both the second side and the third side are connected to the tab connecting portions. A connecting piece is disposed between the tabs of every two adjacent core packages. The two tab connecting portions on each connecting body are respectively connected to the tabs on their two sides. The two tab connecting portions on each connecting body are bent toward each other in a direction away from the core package and are parallel to the end of the core package. The tabs and the tab connecting portions connected to them are bent in the same direction and are parallel to the end of the core package.

[0021] In one embodiment, along the first direction E, the width of the connecting body is W1, the total thickness of two adjacent core packages is W2, and W1 and W2 satisfy: 0.5≤W1 / W2≤1.

[0022] In one embodiment, the length of the battery cell is L, the height of the battery cell is H, and L and H satisfy: L / H≥3.

[0023] In one embodiment, the length of the tab connection portion extending outward from the first side is 8mm-12mm, and the thickness of a single cell along the first direction E is greater than or equal to 12mm.

[0024] The beneficial effects of the embodiments of this utility model are as follows:

[0025] In the embodiments of this utility model, by connecting the tab connection part of the connecting body to the tab of the core package, and connecting the pole connection part of the connecting body to the pole of the battery cell, the tab and pole can be connected through the connecting body. The reinforcing rib is set in the accommodating space between the two core packages, so as to make full use of the empty space in the shell and thereby improve the energy density of the battery cell. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a structural schematic diagram of the connecting piece provided in an embodiment of the present invention from a first-view perspective;

[0028] Figure 2 This is a structural schematic diagram of the connecting piece provided in an embodiment of the present invention from a second perspective;

[0029] Figure 3 This is an exploded view of the cover plate assembly provided in an embodiment of this utility model;

[0030] Figure 4 This is a schematic diagram of the pole structure provided in an embodiment of the present invention;

[0031] Figure 5 The embodiment of this utility model provides that the pole post is assembled on the cover plate body along the rear edge. Figure 3 A partial sectional view of AA;

[0032] Figure 6 This is a schematic diagram of the battery cell structure provided in an embodiment of this utility model.

[0033] Explanation of reference numerals in the attached drawings: Connecting piece -1; Connecting body -11; First surface -111; Second surface -112; Reinforcing rib -113; Electrode connecting part -12; Bending groove -121; Through hole -1211; Electrode connecting part -13; Electrode mounting hole -131; Fusible hole -132; Cover plate body -2; Electrode -3; First groove -31; Second groove -32; First section -33; Second section -34; Plastic part -4; Pressure ring -5; Electrode -6; Housing -7; Core package -8; Accommodation space -9. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0035] Firstly, please refer to Figures 1-6 This utility model provides a connecting piece 1, applied in a battery cell. The battery cell package 8 includes a plurality of core packages 8 arranged sequentially along a first direction E. A tab 6 is provided on the end of each core package 8. The ends of two adjacent core packages 8 are separated and define a receiving space 9. The connecting piece 1 includes:

[0036] The connecting body 11 has a first surface 111 and a second surface 112 facing away from each other in the thickness direction. The connecting body 11 is used to attach to the end of the core package 8 with the first surface 111 facing the core package. The connecting body 11 also has a first side and a second side connected and located between the first surface 111 and the second surface 112. The connecting body 11 is provided with a reinforcing rib 113, which protrudes from the first surface 111 and is used to be received in the receiving space 9.

[0037] The tab connection 12 is connected to the first side surface. The tab connection 12 is bent relative to the connecting body 11 and protrudes from the second surface 112. The tab connection 12 is used to connect the tab 6.

[0038] The pole connection part 13 is connected to the second side surface. The pole connection part 13 is bent relative to the connecting body 11 and protrudes from the first surface 111.

[0039] It is understandable that, to improve the energy density of the battery cell, the tab 6 can be led out from one end of the core package 8, and the terminal post 3 can be set at one end of the core package 8 and integrated into the cover plate. When multiple core packages 8 are arranged side by side, to improve the energy density of the battery cell, adjacent core packages 8 can be arranged close together. However, even after being close together, there is still a certain accommodating space 9 at the edge of the contact surface between the two. As an example, the cross-section of the core package 8 is elliptical, or the width of the two sides of the core package 8 along the first direction E is smaller than that of the middle. By setting the reinforcing rib 113 in the middle of the connecting body 11, the reinforcing rib 113 can be accommodated in the accommodating space 9, which can improve the utilization rate of the internal length space of the battery cell.

[0040] It is understood that this application connects the tab connection portion 12 of the connecting body 11 to the tab 6 of the core package 8, and connects the terminal connection portion 13 of the connecting body 11 to the terminal 3 of the battery cell. Thus, the tab 6 and terminal 3 can be connected through the connecting body 11. After the tab connection portion 12 is connected to the tab 6, the tab connection portion 12 and the tab 6 can be bent and flattened before being placed into the battery cell housing 7 for assembly. This reduces the space occupied by the connecting piece 1 in the housing 7, fully utilizing the space within the housing 7 and thereby increasing the energy density of the battery cell. The tab 6 of the core package 8 is divided into a positive tab and a negative tab, and the corresponding connecting piece 1 is divided into a positive connecting piece 1 and a negative connecting piece 1. The positive connecting piece 1 is used to connect to the positive tab, and the negative connecting piece 1 is used to connect to the negative tab.

[0041] As an example, the connecting body 11, the tab connection portion 12, and the pole connection portion 13 are all sheet-like, thereby reducing the space occupied by the connecting piece 1. The extension direction of the tab connection portion 12 can be parallel to the extension direction of the tab 6, and the extension direction of the pole connection portion 13 can be parallel to the cover plate. During installation, the connecting body 11 is parallel to and fits against the side of the core package 8, and the pole connection portion 13 is parallel to the end face of the core package 8, thereby facilitating the connection of the tab connection portion 12 to the tab 6 and the connection of the pole connection portion 13 to the pole 3. After installation, the tab connection portion 12 and the tab 6 connected thereto can be folded toward the second surface 112 of the connecting body 11, thereby reducing the space occupied by the tab connection portion 12 and the tab 6 in the housing 7, and thus improving the energy density of the battery cell.

[0042] In one embodiment, along the thickness direction of the connecting body 11, the height of the reinforcing rib 113 protruding from the first surface 111 is 0.5 to 1.5 times the thickness of the connecting piece 1, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5 times, etc. This facilitates the processing of the reinforcing rib 113.

[0043] In one embodiment, the connecting body 11 also has a third side opposite to the second side, and both the second side and the third side are connected to the tab connecting portion 12, and the reinforcing rib 113 is disposed in the middle of the connecting body 11.

[0044] It is understood that the second and third sides of the connecting body 11 are provided with tab connecting portions 12, so that the tabs 6 of two core packages 8 can be connected by a connecting piece 1, thereby reducing the number of connecting pieces 1 and facilitating processing and installation. When multiple core packages 8 are arranged side by side, in order to improve the energy density of the battery cell, adjacent core packages 8 can be arranged close together. However, after being close together, there is still a certain accommodating space 9 at the edge of the contact surface between the two. By setting the reinforcing rib 113 in the middle of the connecting body 11, the reinforcing rib 113 can be accommodated in the accommodating space 9, thereby improving the utilization rate of the internal length space of the battery cell.

[0045] In one embodiment, the reinforcing rib 113 extends along the length direction of the connecting body 11, and the length of the reinforcing rib 113 is 30% to 90% of the length of the connecting piece 1. The length direction of the connecting body 11 is from the second side to the third side, and the third side is the side of the connecting body 11 opposite to the second side.

[0046] It can be understood that the length direction of the connecting body 11 is from the first side to the third side, and also the height direction of the core package 8. The length of the reinforcing rib 113 is 30% to 90% of the length of the connecting piece 1, for example, it can be 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc. In this way, the reinforcing rib 113 can effectively strengthen the strength of the connecting body 11, and at the same time, it can make the reinforcing rib 113 easy to manufacture.

[0047] In one embodiment, the length of the tab connecting portion 12 extending outward from the first side is 8mm-12mm, for example, it can be 8mm, 9mm, 10mm, 11mm, 12mm, etc. This facilitates the connection between the tab connecting portion 12 and the tab 6, while reducing material waste.

[0048] In one embodiment, the root of the tab connection 12 is bent, and a bending groove 121 is formed on the side surface of the root of the tab connection 12 near the connecting body 11. The depth of the bending groove 121 is 25% to 75% of the thickness of the tab connection 12.

[0049] It is understood that the root of the tab connection 12 is located on the side where the tab connection 12 connects to the connecting body 11. By providing a bending groove 121 at the root of the tab connection 12, after the tab connection 12 is connected to the tab 6, it is convenient for the tab connection 12 to be bent toward the second surface 112, thereby reducing the space occupied by the tab connection 12 in the housing 7. The depth of the bending groove 121 is controlled to be 25% to 75% of the thickness of the tab connection 12, for example, it can be 25%, 35%, 45%, 55%, 65%, 75%, etc.

[0050] It is understandable that if the bending groove 121 is too deep, the strength of the connecting piece 1 will be reduced, which will make the connecting piece 1 easy to break. If the bending groove 121 is too shallow, the connecting piece 1 will not be easy to bend at the bending groove 121, which will easily lead to the deformation of the connecting piece 1.

[0051] In one embodiment, at least one through hole 1211 is provided in the bending groove 121, which penetrates the root of the tab connection portion 12. The total length of all through holes 1211 is 20% to 70% of the length of the bending groove 121, for example, it can be 20%, 30%, 40%, 50%, 60%, 70%, etc.

[0052] It is understandable that by providing through holes 1211 within the bending groove 121, it is easier for the connecting piece 1 to bend at the bending groove 121. The number of through holes 1211 can be one or more. If the total length of the through holes 1211 is too small, it is not conducive to the connecting piece 1 bending at the bending groove 121; if the total length of the through holes 1211 is too long, the flow area at the bending groove 121 is relatively small, resulting in insufficient strength at the bending groove 121 and easy breakage during bending.

[0053] In one embodiment, the cross-sectional area of ​​the connection between the tab connection 12 and the connection body 11 is S1, the area of ​​the minimum cross-section of the connection body 11 is S2, the pole connection 13 is provided with a fuse hole 132, and the area of ​​the minimum cross-section of the pole connection 13 through the fuse hole 132 is S3. S1, S2 and S3 satisfy: 2S1>S2>S3.

[0054] It is understandable that by making 2S1 > S2 > S3, the electrode connection 13 and the connection body 11 can have good current-carrying capacity, while the fuse hole 132 can have good fusing function. Please refer to [link / reference]. Figure 1 S1 is the section along BB, S2 is the section along CC, and S3 is the section along DD.

[0055] In one embodiment, the pole connection portion 13 is provided with a pole mounting hole 131. The pole mounting hole 131 is a stepped hole. The depth of the step of the stepped hole is 25% to 75% of the total depth of the stepped hole, for example, it can be 25%, 35%, 45%, 55%, 65%, 75%, etc. The width of the step of the stepped hole is 0.5mm to 2mm, for example, it can be 0.5mm, 1.0mm, 1.5mm, 2mm, etc.

[0056] It is understandable that by providing a pole mounting hole 131 on the pole connector 13, the connection between the pole connector 13 and the pole 3 can be facilitated. If the depth of the step is too small as a proportion of the total depth of the step hole, it is not convenient to fix and limit the pole 3. If the depth of the step is too large as a proportion of the total depth of the step hole, the remaining depth of the step hole is too small, and the flow area at the weld after the pole connector 13 and the pole 3 are welded is too small.

[0057] Secondly, embodiments of the present invention provide a cover plate assembly, including a cover plate body 2, an electrode post 3 passing through the cover plate body 2, and the aforementioned connecting piece 1, wherein the electrode post connecting part 13 is connected to the electrode post 3.

[0058] In one embodiment, the surface of the pole post 3 facing the pole post connection portion 13 is recessed to form a first groove 31 extending along the height direction of the pole post 3, and the height of the pole post 3 is at least 3 mm greater than the depth of the first groove 31.

[0059] It is understood that by forming a first groove 31 recessed on the side surface of the pole post 3 facing the pole post connection portion 13, the material usage and weight of the pole post 3 can be reduced. By making the height of the pole post 3 at least 3 mm greater than the depth of the first groove 31, the pole post 3 can meet its welding requirements.

[0060] In one embodiment, a pole mounting hole 131 is provided on the pole connection portion 13. When the pole mounting hole 131 is a stepped hole, a second groove 32 is provided on the periphery of one end of the pole 3 facing the pole connection portion 13, which is adapted to the step of the stepped hole.

[0061] It is understood that by providing a second groove 32 with a stepped hole at the periphery of one end of the pole post 3 facing the pole post connection part 13, when the pole post 3 is connected to the pole post connection part 13, the pole post 3 can be positioned in the pole post mounting hole 131 by matching the stepped hole with the second groove 32, thereby facilitating the connection between the two.

[0062] In one embodiment, the cover plate assembly further includes a plastic part 4 and a pressure ring 5 both sleeved on the pole post 3. The pole post connecting part 13 is disposed at one axial end of the pole post 3, and the pressure ring 5 is disposed at the other axial end of the pole post 3. The plastic part 4 is located between the pressure ring 5 and the pole post connecting part 13. The pole post 3 has a first segment 33 corresponding to the plastic part 4 and a second segment 34 corresponding to the pressure ring 5. The diameter of the first segment 33 is 0.4 mm to 1.0 mm larger than the diameter of the second segment 34, for example, it can be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, etc.

[0063] It is understandable that by making the diameter of the first segment 33 larger than the diameter of the second segment 34, the burning of the plastic part 4 by the welding laser can be reduced when the pressure ring 5 is welded to the electrode post 3. If the difference between the diameters of the first segment 33 and the second segment 34 is too small, the probability of the welding laser burning the plastic part 4 is high when the pressure ring 5 is welded to the electrode post 3. If the difference between the diameters of the first segment 33 and the second segment 34 is too large, it will increase the size of the electrode post 3 and the plastic part 4, wasting space and materials.

[0064] Thirdly, an embodiment of the present invention provides a battery cell, including a core pack 8 and the aforementioned cover plate assembly. A tab 6 is provided on the end of the core pack 8, and the tab 6 is connected to the tab connecting part 12. There are multiple core packs 8, and all core packs 8 are arranged sequentially along the first direction E. The ends of two adjacent core packs 8 are separated and define a receiving space 9. A connecting body 11 is attached to the end of the core pack 8 and the first surface 111 faces the core pack 8. The tab 6 is connected to the tab connecting part 12, and a reinforcing rib 113 is provided in the receiving space 9.

[0065] In one embodiment, the battery cell further includes a housing 7, which is closed to the cover plate body 2. The core package 8 is disposed inside the housing 7. The tabs 6 disposed on the same end of all core packages 8 have the same polarity. The connecting body 11 also has a third side opposite to the second side. Both the second side and the third side are connected to the tab connecting portions 12. A connecting piece 1 is disposed between the tabs 6 of every two adjacent core packages 8. The two tab connecting portions 12 on each connecting body 11 are respectively connected to the tabs 6 on both sides. The two tab connecting portions 12 on each connecting body 11 are bent toward each other in a direction away from the core package 8 and are parallel to the end of the core package 8. The tabs 6 and the tab connecting portions 12 connected to them are bent in the same direction and are parallel to the end of the core package 8.

[0066] It is understood that the second and third sides of the connecting body 11 are provided with tab connecting portions 12, so that the tabs 6 of two core packages 8 can be connected by a connecting piece 1, thereby reducing the number of connecting pieces 1 and facilitating processing and installation. When multiple core packages 8 are arranged side by side in the first direction E, in order to improve the energy density of the battery cell, adjacent core packages 8 can be arranged close together. However, after being close together, there is still a certain accommodating space 9 at the edge of the contact surface between the two. By setting the reinforcing rib 113 in the middle of the connecting body 11, the reinforcing rib 113 can be accommodated in the accommodating space 9, thereby improving the utilization rate of the internal length space of the battery cell. After the tab connecting portion 12 is connected to the tab 6, the tab connecting portion 12 and the tab 6 can be bent and flattened and then placed into the housing 7 of the battery cell for assembly, thereby reducing the space occupied by the connecting piece 1 in the housing 7, making full use of the space inside the housing 7, and thus improving the energy density of the battery cell.

[0067] As an example, each core package 8 has a positive electrode tab and a negative electrode tab protruding from its opposite ends. All positive electrode tabs are located on the same side of the core package 8, and all negative electrode tabs are located on the other side of the core package 8. The positive electrode tabs are connected by a positive electrode connecting piece 1, and the negative electrode tabs are connected by a negative electrode connecting piece 1.

[0068] In one embodiment, along the first direction E, the width of the connecting body 11 is W1, and the total thickness of two adjacent core packages 8 is W2. W1 and W2 satisfy: 0.5≤W1 / W2≤1.

[0069] It is understandable that by ensuring 0.5 ≤ W1 / W2 ≤ 1, the width of the connecting body 11 can be maximized, increasing the current-carrying capacity of the connecting piece 1, thereby reducing the internal resistance of the battery cell and improving its energy efficiency. Simultaneously, it can enhance the main strength of the connecting piece 1, reduce deformation during bending and assembly of the terminal connection 13 and the tab connection 12, and ensure the manufacturability of the assembly. Furthermore, it can fully utilize the space in the thickness direction of the core package 8. When W1 / W2 < 0.5, the width of the connecting body 11 is narrow, resulting in poor current-carrying capacity and poor main strength of the connecting piece 1. When W1 / W2 > 1, the width of the tab connection 12 after bending and flattening exceeds the thickness of the core package 8. During subsequent assembly into the casing, the portion of the tab connection 12 exceeding the width is prone to interference with the aluminum casing, reducing the manufacturability of the battery cell.

[0070] In one embodiment, the length of the battery cell is L, and the height of the battery cell is H, where L and H satisfy: L / H≥3.

[0071] It can be understood that the length of the battery cell refers to the extension length of the battery cell along the first direction E. The height of the battery cell refers to the axial length of the battery cell. By making L / H≥3, the proportion of the tab connection 12 and the tab 6 in the total length L of the battery cell can be reduced, thereby improving the utilization rate of the battery cell housing 7. Compared with the battery cell structure with the tab 6 at the top of the core package 8 (since the positive and negative electrode connecting pieces 1 are set at the same horizontal position, assuming that the two together occupy a height of m, the structure with the tab 6 at the side of the core package 8 is adopted. Because the positive and negative electrode connecting pieces 1 are placed vertically and parallel, and there is a folded part, according to the embodiment, it occupies a length of about 3m (three times m).

[0072] In one embodiment, the length of the tab connection portion 12 extending outward from the first side is 8mm-12mm, and the thickness of a single cell along the first direction E is greater than or equal to 12mm.

[0073] In one embodiment, when a connecting piece 1 has two tab connecting portions 12 that can connect to the tabs 6 of two core packages 8, by making the thickness of a single cell along the first direction E greater than or equal to 12 mm, the width of the tab connecting portion 12 after bending and flattening does not exceed the thickness of the core package 8 (when the tab connecting portion 12 and the tab 6 are assembled and welded, the tab connecting portion 12 extends outward perpendicular to the core package; after the tab connecting portion 12 and the tab 6 are connected, the two tab connecting portions 12 are bent towards the middle of the connecting body 11, and the width of the flattened connecting piece 1 does not exceed the thickness of the core package 8). This makes it less likely to interfere with the aluminum shell and improves the manufacturability of the cell. By making the area of ​​the tab connecting portion 12 as large as possible, the connection area between the tab connecting portion 12 and the tab 6 can be increased. By providing two tab connecting portions 12 on the connecting piece 1, the connection area between the tab connecting portion 12 and the connecting body 11 can be increased, thereby improving the current carrying capacity of the connecting piece 1.

[0074] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A connecting piece, used in a battery cell, the battery cell comprising a plurality of core packages arranged sequentially along a first direction, wherein tabs are provided at the ends of the core packages, and the ends of adjacent core packages are separated and define a receiving space, characterized in that, The connecting piece includes: The connecting body has a first surface and a second surface facing away from each other in the thickness direction. The connecting body is used to be attached to the end of the core package and the first surface faces the core package. The connecting body also has a first side surface and a second side surface connected and located between the first surface and the second surface. The connecting body is provided with a reinforcing rib. The reinforcing rib protrudes from the first surface and is used to be received in the receiving space. The electrode connecting part is connected to the first side surface. The electrode connecting part is bent relative to the connecting body and protrudes from the second surface. The electrode connecting part is used to connect the electrode. The pole connection portion is connected to the second side surface, and the pole connection portion is bent relative to the connection body and protrudes from the first surface.

2. The connecting piece according to claim 1, characterized in that, Along the thickness direction of the connecting body, the height of the reinforcing rib protruding from the first surface is 0.5 to 1.5 times the thickness of the connecting piece; and / or The reinforcing rib extends along the length of the connecting body, and the length of the reinforcing rib is 30% to 90% of the length of the connecting piece. The length direction of the connecting body is from the second side to the third side, and the third side is the side of the connecting body opposite to the second side.

3. The connecting piece according to claim 1, characterized in that, The length of the tab connection portion extending outward from the first side is 8mm-12mm.

4. The connecting piece according to claim 1, characterized in that, The root of the electrode connector is bent, and the surface of the root of the electrode connector near the connector body is recessed to form a bending groove. The depth of the bending groove is 25% to 75% of the thickness of the electrode connector.

5. The connecting piece according to claim 4, characterized in that, The bending groove is provided with at least one through hole penetrating the root of the electrode connecting part, and the total length of all the through holes is 20% to 70% of the length of the bending groove.

6. The connecting piece according to claim 1, characterized in that, The cross-sectional area of ​​the connection between the electrode connecting part and the connecting body is S1, the area of ​​the minimum cross-section of the connecting body is S2, the electrode connecting part is provided with a fuse hole, and the area of ​​the minimum cross-section of the electrode connecting part through the fuse hole is S3. S1, S2 and S3 satisfy: 2S1>S2>S3.

7. The connecting piece according to claim 1, characterized in that, The electrode connection part is provided with an electrode mounting hole, which is a stepped hole. The depth of the step of the stepped hole is 25% to 75% of the total depth of the stepped hole, and the width of the step is 0.5mm to 2mm.

8. A cover plate assembly, characterized in that, It includes a cover plate body, an electrode post passing through the cover plate body, and a connecting piece as described in any one of claims 1 to 7, wherein the electrode post connecting portion is connected to the electrode post.

9. The cover plate assembly according to claim 8, characterized in that, The electrode post has a recessed surface on the side facing the electrode post connection portion, forming a first groove extending along the height direction of the electrode post. The height of the electrode post is at least 3 mm greater than the depth of the first groove; and / or The pole connection part is provided with a pole mounting hole. When the pole mounting hole is a stepped hole, the periphery of the end of the pole facing the pole connection part is provided with a second groove that corresponds to the stepped hole.

10. The cover plate assembly according to claim 8, characterized in that, The cover plate assembly also includes a plastic part and a pressure ring, both sleeved on the pole post. The pole post connecting part is disposed at one axial end of the pole post, and the pressure ring is disposed at the other axial end of the pole post. The plastic part is located between the pressure ring and the pole post connecting part. The pole post has a first segment corresponding to the plastic part and a second segment corresponding to the pressure ring. The diameter of the first segment is 0.4 mm to 1.0 mm larger than the diameter of the second segment.

11. A battery cell, characterized in that, The assembly includes a core package and a cover plate assembly as described in any one of claims 7-10. The core package has an electrode tab at its end, the electrode tab is connected to the electrode tab connecting portion, the number of core packages is multiple, all the core packages are arranged sequentially along a first direction, the ends of two adjacent core packages are separated and define a receiving space, the connecting body is attached to the end of the core package and the first surface faces the core package, and the reinforcing rib is disposed in the receiving space.

12. The battery cell according to claim 11, characterized in that, The battery cell also includes a housing, which is closed to the cover plate body. The core package is disposed inside the housing. The tabs disposed on the ends of all the core packages have the same polarity. The connecting body also has a third side opposite to the second side. The second side and the third side are both connected to the tab connecting portions. A connecting piece is disposed between the tabs of every two adjacent core packages. The two tab connecting portions on each connecting body are respectively connected to the tabs on both sides. The two tab connecting portions on each connecting body are bent toward each other in a direction away from the core package and are parallel to the end of the core package. The tabs and the tab connecting portions connected to them are bent in the same direction and are parallel to the end of the core package.

13. The battery cell according to claim 11, characterized in that, Along the first direction, the width of the connecting body is W1, and the total thickness of two adjacent core packages is W2. W1 and W2 satisfy: 0.5≤W1 / W2≤1.

14. The battery cell according to claim 11, characterized in that, The length of the battery cell is L, and the height of the battery cell is H. The L and H satisfy: L / H≥3.

15. The battery cell according to claim 12, characterized in that, The length of the tab connection portion extending outward from the first side is 8mm-12mm, and the thickness of a single core package along the first direction is greater than or equal to 12mm.

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