A large cylindrical lithium battery structure with hard connection of current collecting plate and pole

Abstract

This utility model discloses a large cylindrical lithium battery structure with a hard connection between the current collector and the terminal, relating to the technical field of cylindrical batteries. It includes a casing, inside which a core is connected. A positive current collector and a negative current collector are respectively connected to the upper and lower sides of the core. The positive and negative current collectors have a plurality of heat dissipation and ventilation holes arranged in a circular array. The center of the negative current collector has a flange, which is inserted into the terminal below the top cover assembly. This application divides the current collector into a positive and a negative current collector, and the terminal is directly welded to the flange at the center of the current collector, which is equivalent to the terminal being directly connected to the negative electrode of the core. This reduces the internal resistance of the cell and avoids heat generation, making it suitable for high-rate charge and discharge conditions. Compared with the original soft connection scheme, the "Z" folding process of the current collector can be omitted, significantly reducing the current collector area and greatly lowering the manufacturing cost of the large cylindrical lithium battery.

Description

Technical Field

[0001] This utility model relates to the technical field of cylindrical batteries, and in particular to a large cylindrical lithium battery structure with a current collector and a terminal post rigidly connected. Background Technology

[0002] Existing large cylindrical collectors are connected to the poles using a flexible welding method. The method involves shaped like a tennis racket, with the head welded to the core and the tail welded to the end face of the pole. After welding, the tail is folded into a "Z" shape before being inserted into the casing.

[0003] After welding this type of current collector to the core and terminals, the conductive path of the cell becomes longer, increasing the internal resistance and heat generation, posing a safety hazard. Furthermore, this current collector requires a "Z" folding process before being packaged, adding to the manufacturing process of the large cylindrical battery and increasing its cost. This type of current collector is very thin, making it difficult to operate under high-rate charging and discharging conditions, as it is prone to melting. To operate under high-rate charging and discharging conditions, thicker materials are needed, but thicker materials are more susceptible to damage or breakage at the folds during the "Z" folding process. To avoid breakage, a larger fold radius is needed, but this fold radius occupies internal space in the casing, requiring a shorter core design and reducing battery capacity. This type of current collector has a large overall area, resulting in high material costs. Additionally, its thinness and large area make it prone to deformation, affecting the welding quality in subsequent processes, and it is unsuitable for high-rate functional batteries. Utility Model Content

[0004] Purpose of the invention: The purpose of this utility model is to provide a large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post, which solves the problems of existing current collectors causing serious heat generation during use, high installation cost, inability to be used for high-rate charging and discharging functions, and easy damage during the welding process.

[0005] Technical solution

[0006] A large cylindrical lithium battery structure with a rigid connection between the current collector and the terminal post includes an outer shell that is open at one end and closed at the other. The closed end has a recessed platform and a small through hole at its center. A core is connected inside the outer shell. A positive current collector and a negative current collector are respectively connected to the upper and lower sides of the core. The positive and negative current collectors are provided with a plurality of ventilation and heat dissipation holes arranged in a circular array on their circumference. There is a fan-shaped thinning area under the positive current collector. The thinning area is welded to the positive end of the core. The negative current collector has a flange at its center. A top cover assembly is connected to the upper side of the negative current collector. The top cover assembly has a negative terminal post that is inserted into the flange.

[0007] Furthermore, the center of the positive flow collector is provided with a punch for liquid injection and air permeation, and the upper and lower end faces of the positive flow collector are laser welded to the positive electrode of the core and the bottom inner surface of the outer shell, respectively.

[0008] Furthermore, a sealing aluminum sheet for sealing is laser-welded to the bottom outer recessed area of ​​the housing.

[0009] Furthermore, the negative current collector has a through hole extending vertically through the inner side of the flange.

[0010] Furthermore, the negative electrode post passes through the through hole, and the flange is welded to the negative electrode post.

[0011] Furthermore, the top cover assembly includes a top cover sheet, a negative electrode lower rubber pad is connected below the top cover sheet, an insulating ring is connected above the top cover sheet, and a negative electrode post is connected through the center of the insulating ring, the top cover sheet, and the negative electrode lower rubber pad.

[0012] Furthermore, a sealing ring is connected between the negative electrode post and the lower negative electrode pad.

[0013] Furthermore, the upper end of the insulating ring is connected to a negative electrode aluminum cap, which covers the negative electrode.

[0014] Furthermore, an explosion-proof valve is connected between the top cover and the negative electrode pad, extending vertically through both the top cover and the negative electrode pad. A protective patch is connected above the top cover to the explosion-proof valve. Beneficial effects: Dividing the current collector into a positive and a negative current collector, with the electrode directly welded to the raised edge of the current collector, is equivalent to the electrode being directly connected to the negative electrode of the core. This reduces the cell's internal resistance and avoids overheating, making it suitable for high-rate charge / discharge functions. The current collector area is significantly reduced, greatly lowering the manufacturing cost of large cylindrical lithium batteries. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall unfolded structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the negative collector disk structure of this utility model;

[0017] Figure 3 This is a schematic diagram of the positive collector disk structure of this utility model;

[0018] Figure 4 This is a schematic diagram of the unfolded structure of the top cover assembly of this utility model;

[0019] Figure 5 This is a cross-sectional structural diagram of the top cover assembly of this utility model.

[0020] Reference Numerals: 1, insulating ring; 2, negative electrode post aluminum cap; 3, negative electrode post; 4, top cover sheet; 5, lower rubber pad of negative electrode; 6, sealing ring; 7, explosion-proof valve; 8, protective patch; 21, negative current collector; 22, heat dissipation holes; 23, flanging; 24, positive current collector; 25, through hole; 26, thinning area; 31, outer shell; 32, winding core; 33, top cover assembly; 34, sealing aluminum sheet. Detailed Embodiments

[0021] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Embodiment 1

[0022] As Figure 1 shown, a large cylindrical lithium battery structure with a hard connection between the current collector and the electrode post includes an outer shell 31. The outer shell 31 is a hollow cylinder with an open end, and its overall shape is "U". There are holes and a counterbore at the center of the bottom of the outer shell 31. The function of this hole is to be the inlet for filling the electrolyte after the battery assembly is completed. After the filling is completed, this opening is welded and sealed.

[0023] A winding core 32 is connected inside the outer shell 31. A positive current collector 24 and a negative current collector 21 are respectively connected to the upper and lower sides of the winding core 32. Both the positive current collector 24 and the negative current collector 21 are circular. A number of heat dissipation holes 22 are arranged in a circumferential array on the positive current collector 24 and the negative current collector 21. A flanging 23 is provided at the center of the negative current collector 21.

[0024] As Figure 2 and Figure 3 shown, a punching 25 is provided at the center of the positive current collector 24. The heat dissipation holes 22 are arranged in an array around the punching 25. There are arrays of thinning areas on the lower end face of the positive current collector 24. The upper and lower end faces of the positive current collector 24 are respectively connected to the positive electrode of the winding core 32 and the bottom wall of the outer shell 31.

[0025] However, after the middle of the negative current collector 21 is die-cut, the two flangings 23 are erected. The erected flangings 23 in the middle present a "U" shape. A through hole 26 that penetrates up and down is provided at the center of the two flangings 23. The through hole 26 is the position before the flangings 23 are erected.

[0026] Furthermore, the shape of the erected flanging at the center position of the current collector includes but is not limited to shapes such as "U", "mouth", "◇", "○", "△", circular divided into 3 petals, circular divided into 4 petals, circular divided into 6 petals, circular divided into 8 petals, etc. The electrode post is in interference fit with the shape of these erected flangings to achieve the function of circuit conduction.

[0027] The heat dissipation holes 22 of the negative current collector 21 are arranged in a circumferential array on the circumferential side of the flanging 23.

[0028] This innovative stamping and flanging process allows the negative electrode post 3 in the top cover assembly 33 to be tightly inserted into the "U"-shaped flanging before welding, thus achieving a concentric direct connection between the electrode post 3 and the core 32 in the top cover assembly 33. This shortens the battery's conductive path and reduces its internal resistance. Compared to existing methods, this connection method eliminates the "Z" folding process, reducing battery assembly time. After the upper and lower ends of the negative electrode current collector 21 are welded to the electrode post 3 and the core 32 in the top cover assembly 33, respectively, they can be directly inserted into the casing.

[0029] The top cover assembly 33 is connected to the upper side of the negative current collector 21, and the top cover assembly 33 is welded to the periphery of the outer shell 31.

[0030] like Figure 4 and Figure 5 As shown, the top cover assembly 33 includes a top cover plate 4, which is the main body. The top cover plate 24 and the outer shell 31 are laser welded to wrap and fix the bare battery cell and achieve the sealing effect of the outer shell 31.

[0031] A negative electrode pad 5 is connected below the top cover plate 4, and an insulating ring 1 is connected above the top cover plate 4. A negative electrode post 3 is connected through the center of the insulating ring 1, the top cover plate 4 and the negative electrode pad 5. The lower end of the negative electrode post 3 is welded to the core 32 to ensure that the core 32 conducts electricity normally.

[0032] During assembly, the two raised flanges 23 are inserted into the negative terminal 3 with an interference fit, and then through soldering is performed.

[0033] The negative electrode pad 5 has several heat dissipation holes to ensure normal operation of the battery cell.

[0034] A sealing ring 6 is connected between the negative electrode post 3 and the negative electrode lower pad 5. The sealing ring 6 can prevent the electrolyte inside the outer casing 31 from leaking.

[0035] The upper end of the insulating ring 1 is connected to the negative terminal aluminum cap 2, which covers the negative terminal 3. The negative terminal aluminum cap 2 is the negative terminal of the large cylindrical battery.

[0036] Furthermore, an explosion-proof valve 7 is connected between the top cover plate 4 and the negative electrode lower rubber pad 5. The explosion-proof valve 7 is located on one side of the negative electrode post 3. The explosion-proof valve 7 passes through the top cover plate 4 and the negative electrode lower rubber pad 5 from top to bottom. A protective patch 8 is connected above the top cover plate 4 to the explosion-proof valve 7.

[0037] The explosion-proof valve 7 is installed on the top cover assembly 33. When the battery malfunctions and the internal pressure increases to a certain value, the explosion-proof valve 7 can open to release pressure and reduce the risk of explosion.

[0038] During assembly, firstly, the positive current collector 24 is firmly welded to the positive terminal of the core 32. Next, the negative current collector 21 is firmly welded to the negative terminal of the core 32. Then, the negative terminal post 3 of the top cover assembly 33 is inserted into the upright position of the middle flange 23 of the negative current collector 21. Laser penetration welding is then performed on the upright positions of both flanges 23 to firmly connect the negative current collector 21 to the negative terminal post 3. Next, the core 32 and the welded positive and negative current collectors are aligned with the center of the outer shell and inserted into the shell, assembling the core 32 inside the shell. Then, penetration welding is performed at the contact point between the positive current collector 24 and the outer shell 31. Finally, a sealing weld is performed around the contact area between the top cover assembly 33 and the outer shell 31. The assembled and welded large cylindrical cell is then baked to remove moisture. After baking, electrolyte is injected into the cell's electrode coil at the center hole of the positive terminal of the outer shell 31. Finally, the sealing aluminum sheet 34 is installed on the positive end injection hole and sealed by welding.

[0039] After the large cylindrical battery cell is assembled, injected with electrolyte, and sealed, it can be activated by charging and discharging.

[0040] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A large cylindrical lithium battery structure with a current collector and a terminal post rigidly connected, comprising a casing (31) that is open at one end and closed at the other end, with a recessed platform and a through-hole at the center of the closed end, and a winding core (32) connected inside the casing (31), characterized in that: The upper and lower sides of the core (32) are respectively connected to a positive current collector (24) and a negative current collector (21). The positive current collector (24) and the negative current collector (21) are provided with a number of ventilation and heat dissipation holes (22) in a circular array. There are four fan-shaped thinning areas (26) under the positive current collector (24). The thinning areas (26) are welded to the positive end of the core (32). The center of the negative current collector (21) is provided with a flange (23). The upper side of the negative current collector (21) is connected to a top cover assembly (33). The top cover assembly (33) is provided with a negative terminal post (3) that is inserted into the flange (23).

2. The large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 1, characterized in that, The center of the positive flow collector (24) is provided with a punch (25) for liquid injection and air permeation. The upper and lower end faces of the positive flow collector (24) are laser welded to the positive pole of the core (32) and the bottom inner surface of the outer shell (31), respectively.

3. The large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 2, characterized in that, The outer bottom surface of the housing (31) is laser-welded with a sealing aluminum sheet (34) for sealing.

4. The large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 1, characterized in that, The negative collector (21) has a through hole (26) that runs vertically through the inside of the flange (23).

5. A large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 4, characterized in that, The negative electrode post (3) passes through the through hole (26), and the flange (23) and the negative electrode post (3) are welded together.

6. A large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 4, characterized in that, The top cover assembly (33) includes a top cover plate (4), a negative electrode lower rubber pad (5) is connected below the top cover plate (4), an insulating ring (1) is connected above the top cover plate (4), and a negative electrode post (3) is connected through the center of the insulating ring (1), the top cover plate (4) and the negative electrode lower rubber pad (5).

7. A large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 6, characterized in that, A sealing ring (6) is connected between the negative electrode post (3) and the negative electrode lower pad (5).

8. A large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 6, characterized in that, The upper end of the insulating ring (1) is connected to the negative electrode aluminum cap (2), and the negative electrode aluminum cap (2) covers the negative electrode (3).

9. A large cylindrical lithium battery structure with a hard connection between the current collector and the terminal post according to claim 6, characterized in that, An explosion-proof valve (7) is connected between the top cover plate (4) and the negative electrode lower rubber pad (5). The explosion-proof valve (7) passes through the top cover plate (4) and the negative electrode lower rubber pad (5) from top to bottom. A protective patch (8) is connected above the top cover plate (4) to the explosion-proof valve (7).

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