Collector plate of battery, lithium battery and battery pack

Abstract

The utility model discloses a current collecting plate of a battery, a plurality of batteries are connected through bars, and the current collecting plate comprises a plate surface positioned at one axial end of the battery; the protruding part protrudes outwards relative to the disc face in the axial direction, the protruding part comprises an end wall, the end wall is one end of the protruding part in the axial direction, and the end wall comprises a bar piece welding area welded to the bar pieces; wherein the disc surface and the protruding part are integrally formed. The current collecting plate can provide an area for direct welding of the current collecting plate and the busbar, so that the current transmission efficiency is improved, the overcurrent capacity of the battery is greatly improved, and the current collecting plate is easy to produce and manufacture. The utility model also discloses a lithium battery and a battery pack.

Description

Technical Field

[0001] The utility model relates to the field of novel batteries, in particular to a battery collecting plate, a lithium battery and a battery pack. Background Art

[0002] With the continuous advancement of technology, demand in areas such as mobile devices and electric vehicles is growing, placing higher demands on the energy density and current handling capacity of lithium batteries. In the field of new energy electric vehicles, in particular, as the penetration rate of new energy electric vehicles increases, electric vehicles using cylindrical battery cells are gradually gaining attention from users. In particular, with the increasing penetration rate of new energy electric vehicles, the fast charging capabilities of electric vehicles are gradually gaining attention from users. In response to users' urgent need for fast charging, various new energy vehicle companies are competing to launch fast charging models. Fast charging means that the battery pack and battery cell must withstand greater current and voltage in a short period of time. Fast charging not only places requirements on the battery cell chemistry, but also places higher current requirements on the battery pack and battery cell structure.

[0003] When the cells are grouped in a PACK, electrical connections (bars) are used to connect the positive and negative output terminals of the cells. Figure 1 As shown, the structural components of the positive output end of the cylindrical battery cell mainly include aluminum pole 01, rivet ring 02, outer plastic 03, sealing ring, inner plastic 04, current collecting plate 05, and steel shell assembly 06. In this structure, the aluminum pole 01 is welded to the plate in the plate welding area S02, allowing them to be grouped within the PACK. At this time, the output capacity of the battery is related to the welding area between the current collecting plate 05 and the welding pin, the welding area between the welding pin and the aluminum pole 01, and the welding area between the plate and the aluminum pole 01. It is subject to multiple restrictions. In addition, the current is conducted through the aluminum pole 01, requiring multiple transfers. The transmission rate and efficiency are low, and the battery's current capacity is also low. Utility Model Content

[0004] To solve the above technical problems, the embodiments of the present utility model disclose a current collecting tray for a battery, wherein multiple batteries are connected by tabs, and the current collecting tray includes:

[0005] The disk is located at one end of the battery axis;

[0006] a protrusion protruding outwardly relative to the disc surface in the axial direction, the protrusion including an end wall, the end wall being one end of the protrusion in the axial direction, and the end wall including a bar welding area for welding to the bar;

[0007] The disk surface and the protruding portion are integrally formed.

[0008] By adopting the above technical solution, an area for direct welding of the current collecting plate and the bar can be provided, without the need for switching through the pole, thereby improving the current transmission efficiency. The current carrying capacity is no longer limited by the contact area of ​​other structures of the current collecting plate. The area of ​​the bar welding area is also improved, which greatly improves the current carrying capacity of the battery and is easy to produce and manufacture.

[0009] Optionally, the battery includes a tab, and the disk surface includes a tab welding area welded to the tab; and / or, the battery includes a pole, the protrusion includes a side wall, the side wall is located between the disk surface and the end wall along the axial direction, and the side wall includes a pole welding area welded to the pole.

[0010] Optionally, the protrusion is a frustum structure, and the cross-sectional area of ​​the frustum structure increases along the direction from the end wall to the disk surface.

[0011] Optionally, the thicknesses of the end wall, the side wall and the disk surface are H1, H2 and H3 respectively, wherein H1=H2=H3.

[0012] Optionally, along the axial direction, the distance between the end wall and the disk surface is D, wherein 1 mm < D < 5 mm, and 1 < D / H2 < 25.

[0013] Optionally, the thicknesses of the end wall, the side wall and the disk surface are H1, H2 and H3 respectively, wherein H1>H2>H3, and 0.2mm≤H3≤0.8mm.

[0014] Optionally, the protrusion includes an abutment boss, which extends outward from the side wall along the circumference of the protrusion, and the pole and the abutment boss abut against each other along the axial direction.

[0015] Optionally, the disk surface includes a buffer zone, and the buffer zone protrudes toward the interior of the battery.

[0016] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a lithium battery, including the above-mentioned current collecting plate.

[0017] By adopting the above technical solution, a lithium battery with higher flow capacity can be obtained, which meets the demand for high flow capacity and expands the application range of lithium batteries.

[0018] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a battery pack including the above-mentioned lithium battery.

[0019] The above technical solution can meet higher fast charging requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1A schematic diagram showing the connection structure between the current collecting plate and the pole in the prior art is shown;

[0021] Figure 2 A schematic structural diagram of a current collecting plate according to an embodiment of the present invention is shown;

[0022] Figure 3 A schematic diagram showing the structure of a current collecting plate and a pole after welding according to an embodiment of the present invention is shown;

[0023] Figure 4 A schematic diagram of the planar structure of a current collecting disc according to an embodiment of the present invention is shown;

[0024] Figure 5 A schematic diagram showing the structure of a current collecting plate with equal wall thickness according to one embodiment of the present invention is shown;

[0025] Figure 6 A schematic diagram showing the structure of a current collecting plate with a gradually varying wall thickness according to an embodiment of the present invention is shown;

[0026] Figure 7 A schematic structural diagram of a collector plate with a gradually varying wall thickness and a pole after welding is shown in one embodiment of the present invention.

[0027] 01. Aluminum pole, 02. Riveted ring, 03. Outer plastic, 04. Inner plastic, 05. Collector plate, 06. Steel shell assembly, S01. Through-hole welding area, S02. Bar welding area,

[0028] 1. Collector plate, 2. Pole

[0029] 10. Disk, 11. Buffer, 20. Protrusion, 21. End wall, 22. Side wall, 23. Abutment boss

[0030] S1. Tab welding area, S2. Pole welding area, S3. Plate welding area DETAILED DESCRIPTION

[0031] The following is an explanation of the implementation of the present invention by means of specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation. On the contrary, the purpose of introducing the utility model in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0032] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0033] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0035] The first aspect of the present invention discloses a current collecting plate of a battery, wherein a plurality of batteries are connected by tabs, such as Figures 2 to 7 As shown, the collecting disc 1 includes a disc surface 10 and a protrusion 20. The disc surface 10 is located at one end of the battery axial direction. Figure 2 As shown, the axial direction is, for example, Figure 2 Direction A in the diagram. The protrusion 20 protrudes outwardly relative to the disk surface 10 in the axial direction, that is, it protrudes in the direction away from the battery, that is, the protrusion 20 takes the disk surface 10 as a starting point and extends in the direction away from the battery. The protrusion 20 includes an end wall 21, which is one end of the protrusion 20 in the axial direction, and the end wall 21 includes a bar welding area S3 for welding with the bar. Through the bar welding area S3, the collecting disk 1 can be directly welded to the bar, and the transfer of current between the bar and the battery cell is no longer limited to the contact area of ​​​​a variety of structures, and it is not necessary to conduct the current through the poles, which reduces the number of current transfers and can be conducted directly through the collecting disk, reducing the current loss during transmission. Moreover, compared to Figure 1 The structure shown, such as Figure 4 As shown, the area of ​​region S3 is relatively large, far exceeding the combined weld area between the collector plate 05 and the welding pins, the welding pins and the aluminum pole 01, and the tab and aluminum pole 01. This increases the cross-sectional area for current flow, enhances transmission efficiency, and improves battery performance. Furthermore, the disc surface 10 and the protrusion 20 are integrally formed. That is, the entire collector plate 1 is integrally stamped and stretched, with the protrusion 20 being pulled out of the disc-shaped structure. This restructures the collector plate 1 in a simple manner, elevating the current collector plate 1 to allow for direct contact with the tabs and facilitating manufacturing.

[0036] In a specific embodiment of the present invention, the battery includes a tab, and the disk surface 10 includes a tab welding area S1 welded to the tab.

[0037] In the specific implementation of the present invention, further reference is made to Figure 2 and Figure 3 The battery includes a pole, the protrusion 20 includes a side wall 22, the side wall 22 is axially located between the disk surface 10 and the end wall 21, and the side wall 22 includes a pole welding area S2 welded to the pole.

[0038] In order to improve the energy density and overcurrent capacity of the battery cell, Figure 1 In the penetration welding area S01 of the structure, the collector plate and the pole are connected by penetration welding to improve the stability of the connection. However, when welding a thin collector plate, it is easy to melt through, causing a short circuit in the battery cell. Figure 3 The welding position of the pole 2 can be shifted to the side wall 22, specifically to the S2 region. Instead of using penetration welding to weld the pole 2 to the current collecting plate 1, the pole 2 can be securely connected to the current collecting plate 1 using lap welding, without penetrating the plate. This improves manufacturing consistency, significantly increases production efficiency, and results in a high manufacturing yield and improved battery performance stability. Furthermore, the pole 2 can be arranged around the protrusion 20, specifically around the side wall 22, abutting against it, and then the two can be welded together using lap welding.

[0039] In other words, the integrated collector tray of the present invention can simultaneously generate multiple weld zones. These zones are spatially separated and welded to different components. This not only improves the battery's current handling capacity but also enhances structural connection stability, facilitating manufacturing and increasing yield. The collector tray's structure also provides sufficient mechanical support for the multiple weld zones, ensuring structural stability and reliable function.

[0040] In a specific embodiment of the present invention, one end of the battery is the positive terminal, and the current collecting plate is the positive electrode current collecting plate of the battery, which can improve the connection stability of the positive electrode and prevent the positive electrode from melting through, thereby ensuring the energy density and current capacity of the battery.

[0041] In a specific embodiment of the present invention, the battery is a cylindrical battery. Accordingly, Figure 4 As shown, the disk surface 10 of the collecting disk 1 is circular, forming a disk-shaped structure.

[0042] In a specific embodiment of the present invention, Figure 2-Figure 3 as well as Figure 5-Figure 7As shown, the protrusion 20 is a truncated cone structure and extends in a direction from the end wall 21 to the disk surface 10 (as shown in FIG. Figure 4 In the direction B shown in the figure, the cross-sectional area of ​​the truncated cone structure becomes larger. Especially in the case of a cylindrical battery, the shape of the current collecting disk 1 can be seen as a truncated cone protruding outward from the disk. Taking the disk surface 10 as the starting point, the side wall 22 is not an upright structure, that is, the side wall 22 is not at a right angle to the disk surface 10. The side wall 22 has a certain inclination angle and is inclined toward the center position of the protrusion 20. The protrusion 20 is a hollow truncated cone with a certain taper. The side wall 22 is the side of the truncated cone structure, the end wall 21 is the top surface of the truncated cone structure, and the truncated cone structure does not have a bottom surface. Through this arrangement, after the pole 2 is welded to the side wall 22 by lap welding, the inclination of the side wall 22 can also provide certain mechanical support for the pole 2, especially in the direction along the axial direction of the battery, which can give the pole 2 a certain supporting force, making the connection between the pole 2 and the current collecting disk 1 more stable, thereby ensuring the reliability of the battery end structure.

[0043] Furthermore, in the embodiment of the present invention, the disk surface 10, the end wall 21 and the side wall 22 all have a certain wall thickness, such as Figure 2 As shown, the wall thickness of the disk surface 10 is H1, the wall thickness of the end wall 21 is H3, and the wall thickness of the side wall 22 is H2.

[0044] In a specific embodiment of the present invention, the collecting plate 1 is in the form of uniform wall thickness, such as Figure 5 As shown, H1 = H2 = H3, meaning that the disc surface 10, end wall 21, and side wall 22 are of equal thickness, with consistent thickness across all components. More specifically, the disc surface 10 and protrusion 20 are integrally formed, meaning the entire collecting disc 1 is integrally stamped and stretched, conveniently achieving a thickness relationship of H1 = H2 = H3 across all components. Specifically, H1 ≥ 0.8 mm.

[0045] More specifically, if Figure 5 As shown, the distance between the end wall 21 and the disk surface 10 is D. That is, the length from the bottom of the end wall 21 to the top of the disk surface 10 is D. Here, 1mm < D < 5mm, and 1 < D / H2 < 25. With this arrangement, the protrusion 20 can have more stable mechanical properties, a more reliable structure, and further enhance the weld to the terminal.

[0046] In a specific embodiment of the present invention, the collecting plate 1 is in the form of a gradually changing wall thickness, such as Figure 6-Figure 7As shown, H1>H2>H3. In other words, the disc 10, end wall 21, and side wall 22 are not of equal thickness. The disc 10 is thinnest, the end wall 21 is thickest, and the side wall 22 is intermediate. From the disc 10 to the side wall 22 and then to the end wall 21, the wall thickness gradually changes from thin to thick, making the protrusion 20 more stable. Furthermore, considering that the welding location between the pole and the collector plate is near the end wall 21 in the side wall 22, the end wall 21 is thickest. The relatively thin end wall 21 ensures both convenient and stable welding at the connection between the end wall 21 and the side wall 22, while also ensuring strength. Furthermore, the disc 10 and the protrusion 20 are integrally formed. When the protrusion 20 and the disc 10 are integrally formed, the side wall 22 connecting the end wall 21 and the disc 10 has an intermediate thickness. This not only improves the structural stability of the collector plate 1, but also facilitates its manufacture and facilitates stretch forming. Furthermore, during stretch forming, the connection between the side wall 22 and the disk surface 10, and the connection between the side wall 22 and the end wall 21, can naturally form a stable bending area. With the structure of the gradually varying wall thickness, the connection has reliable mechanical stability. Specifically, 0.2mm≤H3≤0.8mm. More specifically, 0.2mm≤H1≤0.8mm. In this case, the collector plate 1 is relatively thin as a whole. For example, by using a 0.2mm thick sheet and controlling the integrated stamping process, H1>H2>H3 can be achieved during the formation of the protrusion 20. However, the difference between H1, H2, and H3 is not very large, and can be achieved within a small size range of about 0.2mm. Furthermore, 0.2mmH2>H3. Preferably, 0.8 mm ≤ H1 ≤ 1.5 mm, which can more reliably ensure the stability of welding between the collecting plate and the pole, and facilitate further processing.<h1>

[0047] In a specific embodiment of the present invention, Figure 2-Figure 3 The protrusion 20 may also include an abutment boss 23. Along the circumference of the protrusion 20, the abutment boss 23 extends outward from the side wall 22, and along the axial direction of the battery, the pole 2 and the abutment boss 23 abut each other. The abutment boss 23 can be set in a position slightly above the middle of the side wall 22, closer to the welding position between the pole 2 and the side wall 22. The abutment boss 23 can further provide support for the pole 2, improve the overall mechanical properties of the protrusion 20, and facilitate the positioning of the current collecting plate 1 and the pole 2 during welding. In addition, during the use of the battery, some gas may be generated from the battery, thereby generating a certain thrust on the protrusion 20. By utilizing this thrust, the abutment boss 23 can improve the tightness of the connection between the current collecting plate 1 and the pole 2, enhance the sealing of the weld, and further improve the battery performance.

[0048] Specifically, the abutment boss 23 is a structure fixedly connected to the side wall 22. Preferably, the abutment boss 23 and the side wall 22 are integrally formed. Specifically, during the manufacturing process, the side wall 22 can be bent inward in the upper middle area of ​​the protrusion 20, thereby forming a step-shaped abutment boss 23. It can be considered that with the abutment boss 23 as the boundary, the protrusions 20 on both sides thereof will undergo a sudden change in cross-sectional area, and the side wall 22 forms a dislocation. Along the direction from the connection part of the side wall 22 and the disk surface 10 to the end wall 21, the side wall 22 forms an inwardly contracted part at the abutment boss 23. Furthermore, the pole 2 can be designed to have a structure corresponding to the shape of the abutment boss 23, forming a matching relationship, which makes assembly more convenient and the abutment can also be more stable.

[0049] In a specific embodiment of the present invention, Figure 5 As shown, the disc 10 includes a buffer zone 11 that protrudes toward the interior of the battery. Specifically, during manufacturing, the disc 10 can be bent to form a convex, bent rib area, which serves as the buffer zone 11. The structural design of the buffer zone 11 can reduce vibration amplitude, absorb and disperse vibration energy, and weaken the vibration energy transmitted from the cell casing to the winding core during battery cell vibration. This reduces vibration interference with the internal structure of the cell, helps maintain the cell's optimal operating state, and improves its performance stability.

[0050] The second aspect of the present invention discloses a lithium battery, which adopts the above-mentioned collecting disc structure, and the current flow capacity is improved and relatively stable, thereby improving the safety performance and cycle performance of the battery, and is simple to manufacture and easy to produce and process.

[0051] The third aspect of the present invention discloses a battery pack, comprising the above-mentioned lithium battery, wherein the lithium battery is electrically connected to other batteries via a tab to form a battery pack.

[0052] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above description is provided to further illustrate the present invention in conjunction with specific embodiments, and that the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make various changes in form and detail, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A current collecting tray of a battery, wherein a plurality of batteries are connected by tabs, characterized in that: The collecting plate comprises: A disk surface is located at one end of the battery axis; a protrusion protruding outwardly relative to the disk surface along the axial direction, the protrusion including an end wall, the end wall being one end of the protrusion along the axial direction, and the end wall including a bar welding area welded to the bar; Wherein, the disk surface and the protrusion are integrally formed.

2. A current collecting tray for a battery as claimed in claim 1, characterized in that: The battery includes a tab, and the disk includes a tab welding area welded to the tab; And / or, the battery includes a pole, the protrusion includes a side wall, the side wall is located between the disk surface and the end wall along the axial direction, and the side wall includes a pole welding area welded to the pole.

3. A current collecting tray for a battery as claimed in claim 2, characterized in that: The protrusion is a truncated cone structure, and the cross-sectional area of ​​the truncated cone structure increases along the direction from the end wall to the disk surface.

4. A current collecting tray for a battery as claimed in claim 2, characterized in that: The thicknesses of the end wall, the side wall and the disk surface are H1, H2 and H3 respectively, wherein H1=H2=H3.

5. A current collecting tray for a battery as claimed in claim 2, characterized in that: Along the axial direction, the distance between the end wall and the disk surface is D, wherein 1 mm < D < 5 mm, and 1 < D / H2 < 25.

6. A current collecting plate for a battery as claimed in claim 2, characterized in that: The thicknesses of the end wall, the side wall and the disk surface are H1, H2 and H3 respectively, wherein H1>H2>H3, and 0.2mm≤H3≤0.8mm.

7. A current collecting tray for a battery as claimed in claim 2, characterized in that: The protrusion includes an abutting boss, which extends outward from the side wall along the circumference of the protrusion. Along the axial direction, the pole and the abutting boss abut against each other.

8. The current collecting tray of a battery according to claim 1, characterized in that: The disk surface includes a buffer zone protruding toward the interior of the battery.

9. A lithium battery, characterized in that: The device comprises the collecting plate according to any one of claims 1 to 8.

10. A battery pack, characterized in that: Including the lithium battery as claimed in claim 9.

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