Convergence piece, cover plate assembly and battery cell

Abstract

The utility model provides a bus member, a cover plate assembly and a battery cell, and relates to the technical field of batteries. The bus piece comprises a disc body and a conductive handle; one end of the conductive handle is connected with the edge of the disc body; wherein the connecting part between the conductive handle and the disc body is a to-be-bent part, a weakening area is arranged in the to-be-bent part, and the weakening area is configured to enable the anti-bending strength of the to-be-bent part to be smaller than the anti-bending strength of the part, not provided with the weakening area, of the conductive handle. According to the application, the weakening area is arranged, so that the anti-bending strength of the to-be-bent part is smaller than the anti-bending strength of the part, without the weakening area, of the conductive handle, the strength of the to-be-bent part can be reduced, the bending difficulty of the to-be-bent part can be reduced, and the height size of the R angle on the bus piece can be reduced. Therefore, not only can the space, occupied by the confluence plate, in the battery cell be reduced so as to facilitate the improvement of the capacity density of the battery cell, but also the distance between the R angle and the roll core can be increased so as to reduce the risk of short circuit in the battery cell caused by the R angle pressed to a material area.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a busbar, a cover plate assembly and a battery cell. BACKGROUND

[0002] The battery cell comprises a shell, a winding core arranged in the shell, and a cover plate assembly for closing the shell. The cover plate assembly comprises an end cover, an output pole arranged on the end cover, and a busbar electrically connecting the output pole and the winding core. The winding core comprises a pole piece and a separator. The pole piece is connected to the busbar through a tab.

[0003] In the related art, the busbar comprises a busbar disc and a conductive handle connected to each other. The busbar disc is connected to the tab, and the conductive handle is connected to the output pole. The busbar disc occupies a large space inside the battery cell, which is not conducive to the reliability of the battery cell. CONTENT OF THE UTILITY MODEL

[0004] Embodiments of the present application provide a busbar, a cover plate assembly and a battery cell, which can reduce the space occupied by the busbar disc inside the battery cell.

[0005] In a first aspect, embodiments of the present application provide a busbar, which comprises a disc body and a conductive handle. One end of the conductive handle is connected to the edge of the disc body. The connection part between the conductive handle and the disc body is a to-be-bent part, and a weakening zone is arranged in the to-be-bent part. The weakening zone is configured to make the bending resistance of the to-be-bent part less than the bending resistance of the part of the conductive handle without the weakening zone.

[0006] In an embodiment, the weakening zone comprises a through hole arranged in the to-be-bent part.

[0007] In an embodiment, the width of the conductive handle is W, the through hole has a size a in the width direction of the conductive handle, and 0

[0008] In an embodiment, 0.5mm≤a≤0.8W.

[0009] In an embodiment, the thickness of the part of the conductive handle without the weakening zone is t, the through hole has a size b in the length direction of the conductive handle, and 0

[0010] In an embodiment, 0.5mm≤b≤bmax.

[0011] In an embodiment, the through hole is any one of the following holes: a strip hole, an elliptical hole, a circular hole, and a rectangular hole. When the through hole is a strip hole, the longest diameter of the strip hole is parallel to the width direction of the conductive handle. When the through hole is a rectangular hole, the through hole comprises a plurality of rectangular holes, and the plurality of rectangular holes are arranged at intervals in the width direction of the conductive handle.

[0012] In an embodiment, the center distance between the through hole and the disc body is L, the radius of the disc body is R0, and the width dimension of the conductive handle is W, satisfying:

[0013] In an embodiment, the thickness of the weakened area is less than the thickness of the part of the conductive handle where the weakened area is not arranged.

[0014] In an embodiment, the bending strength of the weakened area is lower than the bending strength of the part of the conductive handle where the weakened area is not arranged.

[0015] In a second aspect, an embodiment of the present application provides a cover plate assembly, comprising a cover plate, an output pole, and the busbar described above; the output pole is mounted on the cover plate; and the end of the conductive handle away from the disc body is connected to the output pole.

[0016] In a third aspect, an embodiment of the present application provides a battery cell, comprising a shell, a winding core, and the cover plate assembly described above; the winding core is arranged in the shell; the disc body is connected to the winding core, and the to-be-bent part is bent to be arranged so that the conductive handle is located between the disc body and the output pole.

[0017] The beneficial effects of the embodiments of the present application are as follows:

[0018] In the embodiments of the present application, the bending strength of the to-be-bent part is less than the bending strength of the part of the conductive handle where the weakened area is not arranged by arranging the weakened area, which can reduce the strength of the to-be-bent part, thereby reducing the bending difficulty of the to-be-bent part, so as to facilitate reducing the height dimension of the R angle on the busbar. In this way, not only can the space occupied by the busbar in the battery cell be reduced to facilitate improving the power density of the battery cell, but also the distance between the R angle and the winding core can be increased to reduce the risk of short circuit caused by the R angle pressing the material area in the battery cell. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0020] Figure 1 is a schematic diagram of the cooperation between the busbar in the related art and the winding core;

[0021] Figure 2 is a structural schematic diagram of the busbar provided by an embodiment of the present application;

[0022] Figure 3 is a structural schematic diagram of another busbar provided by an embodiment of the present application;

[0023] Figure 4is a structural schematic view of another busbar provided by an embodiment of the present application;

[0024] Figure 5 is a structural schematic view of another busbar provided by an embodiment of the present application;

[0025] Figure 6 is a structural schematic view of a cover plate assembly provided by an embodiment of the present application;

[0026] Figure 7 is a structural schematic view of an electric core provided by an embodiment of the present application.

[0027] Legend of reference signs:

[0028] 1a - output pole; 2a - busbar; 3a - R angle; 4a - active material;

[0029] 1 - busbar; 11 - disc body; 12 - conductive handle; 13 - to-be-bent portion; 131 - weakened area; 132 - through hole; 14 - R angle;

[0030] 2 - cover plate assembly; 21 - cover plate; 22 - output pole; 23 - upper plastic part; 24 - lower plastic part; 25 - compression ring; 26 - sealing ring;

[0031] 3 - electric core; 31 - shell; 32 - winding core; 33 - tab. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0033] In addition, it should be understood that the specific implementations described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application. In the present application, the orientation words such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, and specifically refer to the direction of the drawing surface in the drawings; and "inner" and "outer" refer to the contour of the device.

[0034] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mount", "connected", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] And the term "including", "containing" or any other variant thereof is intended to cover non-exclusive containing, so that the current collector, the cap assembly and the battery including a series of elements not only include those elements, but also include other elements not explicitly listed, or include the elements inherent to the current collector, the cap assembly and the battery.

[0036] In the description of the embodiments of the present application, the words "example" or "for example" are used to mean example, illustration or description. Any embodiment or design scheme described as "example" or "for example" in the embodiments of the present application is not interpreted as more preferred or having more advantages than another embodiment or design scheme. The use of "example" or "for example" and the like is intended to present the relative concept in a clear manner.

[0037] Before introducing the current collector, the cap assembly and the battery provided by the embodiments of the present application, the related art of the present application is introduced.

[0038] In the related art, the current collector includes a bus bar and a conductive handle connected with each other. The bus bar is connected with the tab of the winding core, and the conductive handle is connected with the output pole of the battery. In order to ensure the connection area between the current collector and the tab, and to improve the operability of the connection between the current collector and the output pole, the connection part between the bus bar and the conductive handle is bent and arranged. The height dimension of the R angle formed by the bent arrangement of the current collector in the axial direction of the battery is greater than the height dimension of the other parts of the current collector, as shown in Figure 1 Figure 1 is a schematic view of the cooperation between the current collector in the related art and the winding core. Figure 1 In the related art, the side of the R angle close to the winding core will be convex to the winding core, which not only causes the current collector to occupy a larger space inside the battery, which is not conducive to the energy density of the battery, but also causes the R angle to press the material area of the winding core and cause short circuit. Moreover, as the charge-discharge rate of the battery increases, the current-carrying area requirement of the current collector increases. Correspondingly, the current-carrying area of the current collector is increased mainly by increasing the thickness of the current collector. The greater the thickness of the current collector, the higher the bending strength of the R angle, and correspondingly, the greater the radius of the R angle. In this way, the R angle of the current collector has a greater amount of pressing the winding core, and the R angle has a higher risk of pressing the material area and causing internal short circuit of the battery.

[0039] ​Based on this, the embodiment of the present application provides a current collector, a cover plate assembly and a battery cell, so as to reduce the height size of the R angle of the current collector, thereby reducing the space occupied by the current collector in the battery cell, facilitating the improvement of the capacity density of the battery cell, and increasing the distance between the R angle and the winding core, thereby reducing the risk of short circuit caused by the R angle pressing into the material area.

[0040] The present application will be described in detail through the following embodiments.

[0041] Please refer to Figure 2 , Figure 2 is a structural schematic diagram of the current collector 1 provided by the embodiment of the present application. The embodiment of the present application provides a current collector 1. The current collector 1 comprises a disc body 11 and a conductive handle 12. One end of the conductive handle 12 is connected with the edge of the disc body 11. The connection part between the conductive handle 12 and the disc body 11 is a to-be-bent part 13. The to-be-bent part 13 is provided with a weakening area 131. The weakening area 131 is configured to make the bending resistance of the to-be-bent part 13 less than the bending resistance of the part of the conductive handle 12 which is not provided with the weakening area 131.

[0042] It can be understood that the bending resistance, also called the bending strength, refers to the ability of a material to resist bending and cracking. When the material is subjected to bending load, stress distribution will occur inside the material. The bending resistance is the limit ability of the material to withstand such bending stress without permanent deformation or fracture. The bending resistance is usually represented by the maximum bending stress that the material can withstand in the bending test.

[0043] Correspondingly, the smaller the bending resistance of the to-be-bent part 13 is, the smaller the R angle 14 formed after the to-be-bent part 13 is bent, that is, the smaller the size of the R angle 14 in the axial direction of the battery cell 3.

[0044] It can be understood that the to-be-bent part 13 is bent to fold the conductive handle 12 to one side of the disc body 11, so as to form the R angle 14 in the to-be-bent part 13.

[0045] It can be understood that the weakening area 131 can be a hole arranged at the to-be-bent portion 13, so that the bending resistance of the to-be-bent portion 13 is less than that of the portion of the conductive handle 12 which is not provided with the weakening area 131. The weakening area 131 can also be a thinning treatment on the to-be-bent portion 13, so that the bending resistance of the to-be-bent portion 13 is less than that of the portion of the conductive handle 12 which is not provided with the weakening area 131. The to-be-bent portion 13 can also be formed of a material with relatively low bending resistance to form the weakening area 131, for example, the to-be-bent portion 13 can be a pure aluminum material, and the rest of the busbar 1 can be an aluminum alloy. For another example, the busbar can also be made of the same material, but the to-be-bent portion 13 and the rest of the busbar 1 are subjected to different process treatments. Specifically, the rest of the busbar 1 can be subjected to a proper heat treatment process to refine the grains, thereby improving the bending resistance of the rest of the busbar 1.

[0046] In the embodiment, by arranging the weakening area 131 so that the bending resistance of the to-be-bent portion 13 is less than that of the portion of the conductive handle 12 which is not provided with the weakening area 131, the strength of the to-be-bent portion 13 can be reduced, thereby reducing the bending difficulty of the to-be-bent portion 13, so as to facilitate reducing the height dimension of the R corner 14 of the busbar 1. In this way, not only the space occupied by the busbar 1 in the inside of the battery cell 3 can be reduced to facilitate improving the capacity density of the battery cell 3, but also the distance between the R corner 14 and the winding core 32 can be increased to reduce the risk of short circuit of the battery cell 3 caused by the R corner 14 pressing the material area.

[0047] In addition, compared with the scheme of arranging the weakening area 131 at the edge line of the to-be-bent portion 13, the embodiment arranges the weakening area 131 in the to-be-bent portion 13, which can effectively avoid the weakening area 131 from being scratched or rubbed with other components due to being located at the edge line of the to-be-bent portion 13, so as to avoid damage to the busbar 1, thereby facilitating guaranteeing the quality of the busbar 1 and facilitating guaranteeing the reliability of the battery cell 3.

[0048] Please refer to Figure 2 In an embodiment, the weakening area 131 includes a through hole 132 arranged at the to-be-bent portion 13. In this way, the weakening area 131 can be formed in a simple manner and is easy to manufacture. Moreover, the material usage of the busbar 1 can be reduced, thereby facilitating lightweight design of the battery cell 3 and reducing material cost.

[0049] Please refer to Figure 2 In an embodiment, the width dimension of the conductive handle 12 is W. Along the width direction X of the conductive handle 12, the through hole 132 has a dimension a, which satisfies: 0

[0050] It can be understood that the size a of the through hole 132 includes but is not limited to 0.05W, 0.1W, 0.18W, 0.22W, 0.25W, 0.28W, 0.32W, 0.35W, 0.4W, 0.41W, 0.45W, 0.48W, 0.5W, 0.55W, 0.58W, 0.6W, 0.66W, 0.75W, 0.8W.

[0051] In the embodiment, through the above setting, on the one hand, the forming of the through hole 132 can be ensured, and on the other hand, the to-be-bent portion 13 can be prevented from being melted to ensure the overcurrent capacity of the to-be-bent portion 13.

[0052] In an embodiment, 0.5mm≤a≤0.8W. In this way, the forming difficulty of the through hole 132 can be reduced, and the bendability of the to-be-bent portion 13 can be improved.

[0053] In an embodiment, the thickness of the part of the conductive handle 12 which is not provided with the weakening area 131 is t, the through hole 132 has a size b along the length direction Y of the conductive handle 12, and 0

[0054] It can be understood that the size b of the through hole 132 includes but is not limited to 0.1πt, 0.4πt, 0.6πt, 0.7πt, 0.8πt, 1πt, 2πt, 3πt, 4πt, 5πt, 6πt, 7πt, 8πt, 9πt, 10πt, 11πt, 12πt.

[0055] It can be understood that after the through hole 132 is set, the diameter d of the R angle 14 formed by bending the to-be-bent portion 13 is (7-12)t, and the circumferential line of the R angle 14 is a curve approximating to a circular arc. Therefore, the circumference L of the R angle 14 is πd=(7-12)πt. Since the conductive handle 12 and the disc body 11 are located on one side of the R angle 14 after the to-be-bent portion 13 is bent, the central angle of the R angle 14 is less than 360°, and part of the circumferential line of the R angle 14 extends to the conductive handle 12 and the disc body 11. Therefore, the size b of the through hole 132 is defined by the length of a whole circle, which can improve the coverage of the size b on the to-be-bent portion 13, so as to facilitate the bending to be carried out smoothly.

[0056] In the embodiment, through the above setting, on the one hand, the forming of the through hole 132 can be ensured, and on the other hand, the size b of the through hole 132 can be prevented from being too long to affect the strength of the conductive handle 12 and the area of the disc body 11.

[0057] In an embodiment, 0.5mm≤b≤bmax. In this way, the forming difficulty of the through hole 132 can be reduced, and the bendability of the to-be-bent portion 13 can be improved.

[0058] Please refer to Figure 2 to Figure 5 , Figure 3is a structural schematic view of another busbar 1 provided by an embodiment of the present application, Figure 4 is a structural schematic view of another busbar 1 provided by an embodiment of the present application, Figure 5 is a structural schematic view of another busbar 1 provided by an embodiment of the present application. In an embodiment, the through hole 132 is any one of the following hole bodies: a strip-shaped hole, an elliptical hole, a circular hole, and a rectangular hole. When the through hole 132 is a strip-shaped hole, the direction of the longest diameter of the strip-shaped hole is parallel to the width direction of the conductive handle 12, as shown in Figure 2 When the through hole 132 is a rectangular hole, the through hole 132 includes a plurality of rectangular holes, and the plurality of rectangular holes are arranged at intervals along the width direction of the conductive handle 12, as shown in Figure 5

[0059] It can be understood that the shape of the through hole 132 can be various, as long as the bending resistance of the to-be-bent portion 13 is less than that of the portion of the conductive handle 12 without the weakening area 131.

[0060] When the through hole 132 includes a plurality of rectangular holes, the total size of the plurality of rectangular holes in the width direction of the conductive handle 12 is size a. For example, the through hole 132 includes three rectangular holes, and the sizes of the three rectangular holes in the width direction of the conductive handle 12 are a1, a2, and a3 in sequence. Correspondingly, the total size of the three rectangular holes in the width direction of the conductive handle 12 is a1+a2+a3, and a1+a2+a3=a.

[0061] When the through hole 132 includes a plurality of rectangular holes, the size of each rectangular hole in the length direction of the conductive handle 12 is size b.

[0062] When the through hole 132 includes a plurality of rectangular holes, the center-to-center distance between the center of each rectangular hole and the center of the disc body 11 in the length direction parallel to the conductive handle 12 is L.

[0063] Please refer to Figure 2 In an embodiment, the center-to-center distance between the through hole 132 and the disc body 11 is L, the radius of the disc body 11 is R0, and the width size of the conductive handle 12 is W, which satisfy:

[0064] In this way, the center position of the through hole 132 is determined by the center of the disc body 11, which can reduce the processing difficulty of the through hole 132 on the one hand, and can ensure the bending position to effectively avoid the interference between the to-be-bent portion 13 and the shell 31 of the battery cell 3.

[0065] ​In addition to the embodiments of the weakening zone 131 provided in the above embodiments, the embodiments of the present application can also adopt another embodiment of the weakening zone 131. In another embodiment, the thickness of the weakening zone 131 is less than the thickness of the part of the conductive handle 12 which is not provided with the weakening zone 131. That is, the weakening zone 131 is thinned so that the bending resistance of the to-be-bent part 13 is less than the bending resistance of the part of the conductive handle 12 which is not provided with the weakening zone 131.

[0066] Referring to Figure 6 , Figure 6 is a structural schematic diagram of the cover plate assembly 2 provided by the embodiments of the present application. Accordingly, the embodiments of the present application provide a cover plate assembly 2. The cover plate assembly 2 comprises a cover plate 21, an output pole 22, and the aforementioned busbar 1. The output pole 22 is mounted on the cover plate 21. The end of the conductive handle 12 away from the disc body 11 is connected with the output pole 22.

[0067] It can be understood that the cover plate assembly 2 further comprises an upper plastic part 23, a lower plastic part 24, a compression ring 25, and a sealing ring 26. Among them, the output pole 22 is provided on the cover plate 21, and the end of the output pole 22 away from the busbar 1 is sleeved by the compression ring 25. The upper plastic part 23 is located between the compression ring 25 and the cover plate 21. The lower plastic part 24 is located between the cover plate 21 and the busbar 1. The sealing ring 26 is located on the side of the cover plate 21 close to the lower plastic part 24 and is sleeved on the output pole 22.

[0068] In the present embodiment, by adopting the busbar 1 provided by some embodiments of the present application, the strength of the to-be-bent part 13 can be reduced, thereby reducing the bending difficulty of the to-be-bent part 13, so as to facilitate reducing the height dimension of the R corner 14 on the busbar 1. In this way, not only the space occupied by the busbar 1 inside the battery cell 3 can be reduced to facilitate improving the capacity density of the battery cell 3, but also the distance between the R corner 14 and the winding core 32 can be increased to reduce the risk of short circuit in the battery cell 3 caused by the R corner 14 pressing the material area.

[0069] Referring to Figure 7 , Figure 7 is a structural schematic diagram of the battery cell 3 provided by the embodiments of the present application. Accordingly, the embodiments of the present application provide a battery cell 3. The battery cell 3 comprises a shell 31, a winding core 32, and the aforementioned cover plate assembly 2. The winding core 32 is arranged in the shell 31. The disc body 11 is connected with the winding core 32, and the to-be-bent part 13 is bent to be arranged so that the conductive handle 12 is located between the disc body 11 and the output pole 22.

[0070] It can be understood that the winding core 32 comprises a positive electrode sheet, a separator, and a negative electrode sheet which are sequentially stacked and wound. The positive electrode sheet is connected with the busbar 1 through the tab 33. The tab 33 of the negative electrode sheet can be connected with the busbar 1 of another cover plate assembly 2, or can be connected with the shell 31.

[0071] In the embodiment, by adopting the cover plate assembly 2 provided by some embodiments of the application, the strength of the to-be-bent part 13 can be reduced, so that the bending difficulty of the to-be-bent part 13 can be reduced, thereby facilitating the reduction of the height dimension of the R corner 14 on the busbar 1. In this way, not only the space occupied by the busbar 1 in the inside of the battery cell 3 can be reduced, thereby facilitating the improvement of the capacity density of the battery cell 3, but also the distance between the R corner 14 and the winding core 32 can be increased, thereby reducing the risk that the R corner 14 is pressed to the material area to cause short circuit in the battery cell 3.

[0072] The above describes the embodiments of the application in detail, and the principles and implementation manners of the application are described by applying specific examples; the above embodiment descriptions are only used to help understand the method of the application and the core idea thereof; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range can be changed, and the above description should not be understood as the limitation of the application.

Claims

1. A busbar, characterized in that, include: Disk body; A conductive handle, one end of which is connected to the edge of the disk body; The connection between the conductive handle and the disk body is a bending section, and a weakening zone is provided in the bending section. The weakening zone is configured such that the bending resistance of the bending section is less than the bending resistance of the part of the conductive handle without the weakening zone.

2. The busbar according to claim 1, characterized in that, The weakened area includes a through hole disposed in the part to be bent.

3. The busbar according to claim 2, characterized in that, The width of the conductive handle is W, and the through hole has a size a along the width direction of the conductive handle, satisfying: 0 < a ≤ 0.8W.

4. The busbar according to claim 3, characterized in that, 0.5mm≤a≤0.8W.

5. The busbar according to any one of claims 2-4, characterized in that, The thickness of the portion of the conductive handle without the weakened area is t. Along the length of the conductive handle, the through hole has a size b, satisfying: 0 < b ≤ bmax, 7πt ≤ bmax ≤ 12πt.

6. The busbar according to claim 5, characterized in that, 0.5mm≤b≤bmax.

7. The busbar according to any one of claims 2-4, characterized in that, The through hole can be any of the following types of holes: strip hole, elliptical hole, circular hole, or rectangular hole; Wherein, when the through hole is a strip-shaped hole, the direction of the longest diameter of the strip-shaped hole is parallel to the width direction of the conductive handle; When the through hole is a rectangular hole, the through hole includes multiple rectangular holes, and the multiple rectangular holes are spaced apart along the width direction of the conductive shank.

8. The busbar according to any one of claims 2-4, characterized in that, The center distance between the through hole and the disk body is L, the radius of the disk body is R0, and the width of the conductive handle is W, satisfying the following:

9. The busbar according to claim 1, characterized in that, The thickness of the weakened region is less than the thickness of the portion of the conductive handle where no weakened region is provided.

10. The busbar according to claim 1, characterized in that, The bending strength of the weakened region is lower than that of the part of the conductive handle where no weakened region is provided.

11. A cover plate assembly, characterized in that, include: Cover plate; The output terminal is mounted on the cover plate; And the busbar as described in any one of claims 1-10, wherein the end of the conductive handle away from the disk body is connected to the output electrode.

12. A battery cell, characterized in that, include: case; The winding core is disposed within the housing; And the cover plate assembly as claimed in claim 11, wherein the disc body is connected to the winding core, and the portion to be bent is bent such that the conductive handle is located between the disc body and the output electrode.

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