Cylindrical battery with non-bending confluence plate structure

Abstract

The utility model discloses a cylindrical battery without a bending confluence disc structure. The cylindrical battery comprises an aluminum shell, a roll core is arranged in an inner cavity of the aluminum shell, a positive electrode assembly is arranged at the positive electrode end of the roll core, a negative electrode assembly is arranged at the negative electrode end of the roll core, and a negative electrode cover plate is arranged at the negative end of the aluminum shell. According to the cylindrical battery, the positive pole confluence plate and the negative pole confluence plate are both of a bending-free structure, so that the internal space of the aluminum shell is saved, the height of the cylindrical battery is reduced, the energy density of the cylindrical battery is improved, the overcurrent capacity of a structural part is improved, the internal resistance is reduced, and the rate capability of the cylindrical battery is improved; the positive pole and the shell are integrally formed, so that electrochemical corrosion of the inner wall of the shell can be effectively prevented, and the service life of the cylindrical battery can be prolonged; the center hole A can be used as a spot bottom welding cut-in hole and can also be used as a liquid injection hole, so that the liquid injection nozzle in the liquid injection process of the cylindrical battery does not need to be rotated and aligned, and the process difficulty and the equipment cost are reduced.

Description

Technical Field

[0001] This utility model belongs to the field of cylindrical battery technology, specifically relating to a cylindrical battery with a non-bending busbar structure. Background Technology

[0002] The full tab structure in cylindrical batteries can effectively reduce the internal resistance and heat generation of cylindrical batteries, improve the rate performance of batteries, achieve fast charging and increase power density.

[0003] The use of multiple tabs and a complex casing structure has become the mainstream development direction for cylindrical lithium-ion batteries, especially large cylindrical batteries. The aluminum casings of multi-tab cylindrical batteries are divided into barrel-shaped and tubular casings.

[0004] Currently, in assembly processes using cylindrical cells with barrel-shaped casings, the positive electrode busbar, after being welded to the positive end face of the cell, needs to be welded to the bottom of the barrel-shaped casing; the negative electrode busbar, after being welded to the negative end face of the cell, needs to be welded to the negative electrode cover plate. When using cylindrical cells with tubular casings, the positive and negative electrode busbars, after being welded to the positive and negative end faces of the cell, need to be welded to the positive and negative electrode cover plates at both ends of the tubular casing, respectively. In both of these casing structures, the connection between the busbar and the cover plate involves extending the busbar and then bending it. The bending point becomes the current path with the highest current density, the weakest point, and the most prone to heat generation, greatly limiting the performance of multi-tab batteries. Furthermore, the bending structure is prone to contact with the casing, causing internal short circuits and affecting battery safety. Utility Model Content

[0005] The purpose of this invention is to provide a cylindrical battery with a bend-free busbar structure to solve the technical problems of high current density at the bending position and heat generation current channel limiting battery performance in existing bend-type busbar structures.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A cylindrical battery with a bend-free busbar structure includes an aluminum shell with a negative terminal opening, an inner cavity containing a core, a positive electrode assembly at the positive terminal of the core, a negative electrode assembly at the negative terminal of the core, and a negative electrode cover plate at the negative terminal of the aluminum shell.

[0008] The aluminum shell includes a shell sleeved on the surface of the core. The closed end of the shell is integrally formed with a positive electrode post. A central hole A is opened in the center of the shell, and a welding area is formed between the positive electrode post and the central hole A.

[0009] The positive electrode assembly includes a positive electrode busbar located at the positive end of the winding core, and a positive electrode insulating sleeve is provided between the positive electrode busbar and the housing.

[0010] The negative electrode assembly includes a negative electrode post located at the center of the negative electrode cover plate, a negative electrode busbar between the negative electrode post and the winding core, and a negative electrode insulating sleeve between the negative electrode busbar and the negative electrode cover plate.

[0011] As a further embodiment of this utility model, the positive electrode busbar includes a disc body A welded to the positive end of the core. The center of the disc body A is integrally formed with a boss A. A central hole B communicating with the through hole of the core is opened at the center of the boss A. An opening A is opened on the surface of the disc body A, and an opening B is opened on the side of the boss A.

[0012] As a further embodiment of this utility model, the positive electrode insulating sleeve is sleeved on the surface of the disk body A, and the boss A is welded to the welding area.

[0013] As a preferred embodiment of this utility model, there are multiple openings A and B arranged in a ring at equal intervals, and openings A and B are spaced apart.

[0014] As a preferred embodiment of this utility model, the center hole A, the center hole B, and the core are coaxially arranged.

[0015] As a preferred embodiment of this utility model, the negative electrode busbar includes a disk body B welded to the negative end of the core and disposed opposite to the disk body A. The center of the disk body B is integrally formed with a boss B, and an opening C is formed on the surface of the disk body B. An opening D is formed on the side of the boss B.

[0016] As a further embodiment of this utility model, the negative electrode insulating sleeve is sleeved on the negative end of the winding core, the disk body B is located in the inner cavity of the negative electrode insulating sleeve, and the boss B is welded to the negative electrode post.

[0017] Compared with the prior art, the cylindrical battery with a bend-free busbar structure provided by this utility model has the following advantages:

[0018] 1. In this utility model, both the positive and negative electrode busbars adopt a non-bending structure, which saves internal space of the aluminum shell, reduces the height of the cylindrical battery, and improves the energy density of the cylindrical battery; at the same time, it increases the current carrying capacity of the structural components, reduces internal resistance, and improves the rate performance of the cylindrical battery.

[0019] 2. The use of openings A, B, C and D in this utility model facilitates the flow and wetting of electrolyte.

[0020] 3. This utility model adopts a barrel-shaped aluminum shell, and uses a negative electrode cover plate for sealing welding at the open end of the aluminum shell, reducing equipment costs; the positive electrode post is integrally formed with the shell and carries a positive charge, which can effectively prevent electrochemical corrosion of the inner wall of the shell and help extend the service life of the cylindrical battery; the central hole A can be used as a spot welding entry hole and also as an injection hole, so that the injection nozzle does not need to be rotated and aligned in the injection process of the cylindrical battery, reducing the process difficulty and equipment costs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only examples of embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model. Figure 1 ;

[0023] Figure 2 This is a schematic diagram of the structure of an embodiment of the present utility model. Figure 2 ;

[0024] Figure 3 This is a cross-sectional structural diagram of an embodiment of the present utility model;

[0025] Figure 4 This is a cross-sectional view of the shell, core, and positive electrode assembly in an embodiment of the present invention.

[0026] Figure 5 This is a cross-sectional view of the shell, core, and negative electrode assembly in an embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the positive electrode busbar in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the negative electrode busbar in an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the structure of the negative electrode post and the negative electrode cover plate in an embodiment of this utility model.

[0030] Figure label:

[0031] 100. Aluminum shell; 110. Shell; 120. Positive electrode post; 130. Center hole A; 140. Welding area;

[0032] 200. Roll core;

[0033] 300. Positive electrode assembly; 310. Positive electrode busbar; 311. Panel A; 312. Boss A; 313. Center hole B; 314. Opening A; 315. Opening B; 320. Positive electrode insulating sleeve;

[0034] 400. Negative electrode assembly; 410. Negative electrode post; 420. Negative electrode busbar; 421. Panel B; 422. Boss B; 423. Opening C; 424. Opening D; 430. Negative electrode insulating sleeve;

[0035] 500, Negative electrode cover. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0037] In the description of the embodiments of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0038] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to the internal connection of two components; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.

[0039] See appendix Figures 1-8 As shown in the figure, an embodiment of the present invention discloses a cylindrical battery with a bend-free busbar structure, including an aluminum shell 100, a core 200, a positive electrode assembly 300, a negative electrode assembly 400, and a negative electrode cover plate 500. The core 200, the positive electrode assembly 300, and the negative electrode assembly 400 are all disposed in the inner cavity of the aluminum shell 100. The positive electrode assembly 300 is disposed at the positive end of the core 200, the negative electrode assembly 400 is disposed at the negative end of the core 200, and the negative electrode cover plate 500 is disposed at the opening at the negative end of the aluminum shell 100.

[0040] The aluminum shell 100 includes a shell 110 sleeved on the surface of the core 200. The shell 110 is open at the end facing the negative electrode cover plate 500. The positive electrode post 120 is integrally formed at the closed end of the shell 110 away from the negative electrode cover plate 500. A central hole A130 is opened on the shell 110. The central hole A130 is located at the center of the positive electrode post 120. A welding area 140 is formed between the positive electrode post 120 and the central hole A130.

[0041] See Figure 4 As shown, the positive electrode assembly 300 includes a positive electrode busbar 310 disposed at the positive end of the winding core 200, and a positive electrode insulating sleeve 320 is provided between the positive electrode busbar 310 and the housing 110; see also Figure 5 As shown, the negative electrode assembly 400 includes a negative electrode post 410 fixedly installed on the negative electrode cover plate 500, a negative electrode busbar 420 is provided between the negative electrode post 410 and the core 200, and a negative electrode insulating sleeve 430 is provided between the negative electrode busbar 420 and the negative electrode cover plate 500.

[0042] See Figure 6 As shown, the positive electrode busbar 310 includes a disk body A311 welded to the positive end of the winding core 200. The thickness of the disk body A311 is 0.3-2mm. A boss A312 is integrally formed at the center of the disk body A311. A central hole B313 communicating with the through hole of the winding core 200 is opened at the center of the boss A312. The diameter of the central hole B313 is 2-10mm. An opening A314 is opened on the surface of the disk body A311, and an opening B315 is opened on the side of the boss A312. The positive electrode assembly 300 can effectively collect and conduct current, and at the same time effectively dissipate heat to maintain the normal operating temperature of the cylindrical battery.

[0043] See Figure 4 As shown, the positive electrode insulating sleeve 320 is sleeved on the surface of the disc body A311, and the thickness of the positive electrode insulating sleeve 320 is 0.5-2mm. The boss A312 is welded and fixed to the welding area 140, and the thickness of the welding area 140 is 0.5-2mm. There are four holes A314 and B315 in a ring at equal intervals, and the holes A314 and B315 are spaced apart. The central hole A130, the central hole B313 and the central axis of the core 200 are on the same straight line.

[0044] See Figure 7 As shown, the negative electrode busbar 420 includes a disk body B421 welded to the negative end of the winding core 200 and arranged opposite to the disk body A311. The thickness of the disk body B421 is 0.2-1mm. A boss B422 is integrally formed at the center of the disk body B421. An opening C423 is opened on the surface of the disk body B421, and an opening D424 is opened on the side of the boss B422. The negative electrode assembly 400 can effectively collect and conduct current, and can also effectively dissipate heat to maintain the normal operating temperature of the cylindrical battery. The negative electrode insulating sleeve 430 is sleeved on the negative end of the winding core 200. The disk body B421 is located in the inner cavity of the negative electrode insulating sleeve 430. The boss B422 is welded and fixed to the negative electrode post 410. The protruding directions of the boss B422 and the boss A312 are opposite.

[0045] The assembly steps of the cylindrical battery in the above-described technical solution of this utility model embodiment are as follows:

[0046] a. Use laser welding to make an electrical connection between the disc body A311 and the positive end of the core 200, with the welding trajectory avoiding the opening A314;

[0047] b. Connect the positive electrode insulating sleeve 320 to the positive end of the core 200 so that the positive electrode busbar 310 is installed inside the positive electrode insulating sleeve 320.

[0048] c. Place the opening of the housing 110 upwards, and place the boss B422 of the disc body B421 upwards on the negative end of the core 200. Use laser welding to achieve electrical connection between the disc body B421 and the negative end of the core 200, with the welding trajectory avoiding the opening C423.

[0049] e. Place the core 200, which is equipped with the positive electrode busbar 310 and the positive electrode insulating sleeve 320, into the housing 110. Apply pressure to the negative end of the core 200 so that the boss A312 is in close contact with the inner wall of the housing 110. Align the through hole, the center hole B313 and the center hole A130 of the core 200. Perform laser penetration welding from the welding area 140 outside the housing 110 to achieve the connection between the housing 110 and the boss A312.

[0050] f. Install the negative electrode post 410, the negative electrode insulating sleeve 430 and the negative electrode cover plate 500 in sequence, so that the negative electrode cover plate 500 is closed with the housing 110 and sealed by welding.

[0051] g. Place the housing 110 with the center hole A130 facing upwards. Insert the spot welding needle sequentially through the center hole A130, the center hole B313, and the through hole of the core 200 until it contacts the boss B422. Apply pressure to make the boss B422 and the negative terminal 410 make tight contact. Then, perform resistance welding or ultrasonic welding on the boss B422 and the negative terminal 410 to achieve the connection between the boss B422 and the negative terminal 410. After welding, remove the welding needle to complete the assembly of the cylindrical battery. Finally, the center hole A130 is used as the baking water outlet and the liquid injection hole, and is sealed by welding in the subsequent process.

[0052] This utility model embodiment of a cylindrical battery with a bend-free busbar structure eliminates the structure of the extended bending of the busbar at both the positive and negative terminals. Without affecting the effective space of the cell, it achieves effective electrical connection between the cell end face, busbar, and cover plate of the all-tab aluminum-cased cylindrical battery. The central hole A130 serves as both the bottom welding entry point and the liquid injection hole.

[0053] The foregoing has shown and described the basic principles of the present invention. The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. The above embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention without departing from the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A cylindrical battery with a non-bendable busbar structure, comprising an aluminum shell (100) with a negative terminal opening, an inner cavity having a core (200), a positive electrode assembly (300) being provided at the positive terminal of the core (200), a negative electrode assembly (400) being provided at the negative terminal of the core (200), and a negative electrode cover plate (500) being provided at the negative terminal of the aluminum shell (100). The aluminum shell (100) includes a shell (110) sleeved on the surface of the core (200). The closed end of the shell (110) is integrally formed with a positive electrode post (120). A central hole A (130) is opened in the center of the shell (110). A welding area (140) is formed between the positive electrode post (120) and the central hole A (130). The positive electrode assembly (300) includes a positive electrode busbar (310) disposed at the positive end of the core (200), and a positive electrode insulating sleeve (320) is provided between the positive electrode busbar (310) and the housing (110). The negative electrode assembly (400) includes a negative electrode post (410) disposed at the center of the negative electrode cover plate (500), a negative electrode busbar (420) is provided between the negative electrode post (410) and the core (200), and a negative electrode insulating sleeve (430) is provided between the negative electrode busbar (420) and the negative electrode cover plate (500).

2. The cylindrical battery of claim 1, wherein: The positive electrode busbar (310) includes a disk body A (311) welded to the positive end of the core (200). The disk body A (311) has a boss A (312) integrally formed at the center. The boss A (312) has a central hole B (313) that communicates with the through hole of the core (200) at the center. The disk body A (311) has an opening A (314) on its surface and an opening B (315) on the side of the boss A (312).

3. The cylindrical battery of claim 2, wherein: The positive electrode insulating sleeve (320) is sleeved on the surface of the disk body A (311), and the boss A (312) is welded to the welding area (140).

4. The cylindrical battery of claim 2, wherein: The openings A (314) and B (315) are multiple and are arranged in a ring at equal intervals, and the openings A (314) and B (315) are spaced apart.

5. The cylindrical battery of claim 2, wherein: The center hole A (130), center hole B (313), and core (200) are coaxially arranged.

6. The cylindrical battery of claim 2, wherein: The negative electrode busbar (420) includes a disk body B (421) welded to the negative end of the core (200) and arranged opposite to the disk body A (311). The disk body B (421) has a boss B (422) integrally formed at the center. The disk body B (421) has an opening C (423) on its surface and an opening D (424) on its side.

7. The cylindrical battery of claim 6, wherein: The negative electrode insulating sleeve (430) is sleeved on the negative end of the core (200), the disk body B (421) is located in the inner cavity of the negative electrode insulating sleeve (430), and the boss B (422) is welded to the negative electrode post (410).

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