A cylindrical secondary battery

Abstract

The utility model relates to cylindrical battery technical field, proposes a cylindrical secondary battery, including positive pole and sealed aluminium sheet, the first recess, second recess and third recess are seted up to positive pole, the inside diameter of first recess, second recess and third recess gradually reduces gradually, sealed aluminium sheet is fixed in second recess, the outer edge of sealed aluminium sheet is equipped with chamfer surface near third recess side, the angle of chamfer surface and second recess circumferential side is D1, the angle of chamfer surface and second recess near third recess side is D2, D1=26.87 DEG-46.87 DEG, D2=43.13 DEG-63.13 DEG. The utility model through setting chamfer surface on sealed aluminium sheet, and limiting the specification of chamfer surface, not only can promote the guiding effect that chamfer surface plays, makes sealed aluminium sheet more easily assemble to positive pole, also can reduce the processing difficulty of sealed aluminium sheet, promotes the yield of battery, thereby effectively promotes the overall performance of battery.

Description

Technical Field

[0001] This utility model relates to the field of cylindrical battery technology, and in particular to a cylindrical secondary battery. Background Technology

[0002] With the rapid development of technology, the demand for energy storage in various electronic devices, electric vehicles, and energy storage systems is increasing. Rechargeable batteries, due to their rechargeable nature, have become a key energy solution to meet these needs. Among them, cylindrical rechargeable batteries, with their compact structure, high energy density, and mature manufacturing processes, have been widely used in numerous application scenarios.

[0003] The terminals are an important component of a cylindrical lithium-ion secondary battery, serving as a key part for the electrical connection between the battery and external circuitry. Terminals are typically fixed to the battery casing using riveting. By applying pressure, plastic deformation occurs between the terminal and the battery casing, creating a strong mechanical and electrical connection. During the riveting process, some material from the terminal is compressed and deformed, filling the corresponding riveting holes or areas on the battery casing to achieve a tight bond.

[0004] For example, the invention patent with publication number CN119764698A discloses a cylindrical battery positive electrode cover assembly, which has an injection hole on the positive electrode post and a sealing aluminum nail in the injection hole to inject liquid into the battery. However, in order to facilitate the assembly of the sealing aluminum nail into the injection hole, the above technical solution sets the periphery of the sealing aluminum nail and the periphery of the injection hole as conical. This structure will increase the processing difficulty of the positive electrode post and the sealing aluminum nail, and reduce the production yield of the battery. Utility Model Content

[0005] In view of this, the present invention proposes a cylindrical secondary battery, which achieves the effect of balancing battery assembly efficiency and assembly yield by setting a chamfered surface on the sealing aluminum sheet and reasonably limiting the specifications of the chamfered surface.

[0006] The technical solution of this utility model is implemented as follows: This utility model provides a cylindrical secondary battery, including a positive electrode post and a sealing aluminum sheet. The positive electrode post has a first groove, a second groove, and a third groove. The first groove is located at one end of the positive electrode post. The first groove, the second groove, and the third groove are coaxially arranged and connected sequentially, and the inner diameters of the first groove, the second groove, and the third groove gradually decrease. The sealing aluminum sheet is fixed in the second groove and abuts against the side of the second groove near the third groove. The outer edge of the sealing aluminum sheet near the third groove has a chamfered surface. The angle between the chamfered surface and the periphery of the second groove is D1, and the angle between the chamfered surface and the side of the second groove near the third groove is D2. D1 = 26.87°-46.87°, D2 = 43.13°-63.13°.

[0007] Based on the above technical solution, preferably, the portion of the sealing aluminum sheet extending beyond the periphery of the third groove is a protrusion, the protrusion has an annular structure, and the chamfered surface is provided on the protrusion; the annular width of the end of the protrusion away from the third groove is L. 321 The annular width of the protrusion near the end of the third groove is L. 421 L 421 / L 321 =32.1%-43.4%.

[0008] Based on the above technical solutions, the preferred option is L. 321 =0.43-0.63mm.

[0009] Based on the above technical solutions, preferably, the thickness of the sealing aluminum sheet is H. 41 The length of the chamfered surface along the thickness direction of the sealing aluminum sheet is H. 402 H 402 / H 41 =35%-45%.

[0010] Based on the above technical solutions, the preferred option is H. 41 =0.8-1.2mm.

[0011] Based on the above technical solutions, preferably, the inner diameter of the third groove is L. 44 The outer diameter of the sealing aluminum sheet near the third groove is L. 42 L 42 / L 44 =101.8%-105.5%.

[0012] Based on the above technical solution, preferably, the outer diameter of the end of the sealing aluminum sheet furthest from the third groove is L. 41L 42 / L 41 =93.3%-96.7%.

[0013] Based on the above technical solutions, the preferred option is L. 42 =11.2-11.6mm.

[0014] Based on the above technical solution, preferably, the side of the sealing aluminum sheet away from the third groove is flush with the side of the first groove near the second groove, and the inner diameter of the first groove is L. 43 L 43 =12.5-14.5mm.

[0015] Based on the above technical solution, preferably, the distance between the sealing aluminum sheet and the side of the third groove away from the second groove is H. 42 H 42 =1.65-2.05mm.

[0016] The cylindrical secondary battery of this invention has the following advantages over the prior art: (1) By setting a chamfered surface on the sealing aluminum sheet and limiting the specifications of the chamfered surface, not only can the guiding effect of the chamfered surface be improved, making it easier to assemble the sealing aluminum sheet into the positive electrode post, but the processing difficulty of the sealing aluminum sheet can also be reduced, the yield of the battery can be improved, and thus the overall performance of the battery can be effectively improved.

[0017] (2) By further limiting the specifications and installation position of the sealing aluminum sheet and the positive electrode post, the assembly yield and assembly efficiency of the battery can be further improved, the processing cost of the battery can be reduced, and the energy density of the battery can be increased, thereby further improving the overall performance of the battery. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional view of a cylindrical secondary battery according to the present invention.

[0020] Figure 2 This is a cross-sectional view of the protruding part in a cylindrical secondary battery according to the present invention.

[0021] Figure 3This is a cross-sectional view of the chamfered surface of a cylindrical secondary battery according to the present invention.

[0022] Figure 4 This is a partial cross-sectional view of a cylindrical secondary battery according to the present invention.

[0023] Figure 5 This is a cross-sectional view of the overall structure of a cylindrical secondary battery according to the present invention.

[0024] Wherein: 1. Positive electrode post; 101. First groove; 102. Second groove; 103. Third groove; 2. Sealing aluminum sheet; 21. Protrusion; 201. Chamfered surface. Detailed Implementation

[0025] The technical solutions of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] This utility model discloses a cylindrical secondary battery, comprising a casing, a positive electrode post 1, and a sealing aluminum sheet 2. The casing is a cylindrical structure with an internal cavity. An installation hole is provided at the positive end of the casing. One end of the positive electrode post 1 passes through the installation hole and extends into the casing, while the other end of the positive electrode post 1 is located outside the casing. The two ends of the positive electrode post 1 are riveted to form two circular plate-like structures with an outer diameter larger than the inner diameter of the installation hole. A sealing and insulating component, such as an upper plastic and a sealing ring, is provided between the positive electrode post 1 and the casing to ensure a sealed and insulated connection between the positive electrode post 1 and the casing.

[0027] The positive electrode post 1 has a first groove 101, a second groove 102, a third groove 103, and a liquid injection hole. The first groove 101 is located at one end of the positive electrode post 1, and the liquid injection hole is located at the other end of the positive electrode post 1. The first groove 101, the second groove 102, the third groove 103, and the liquid injection hole are coaxially arranged and connected in sequence, and the inner diameters of the first groove 101, the second groove 102, the third groove 103, and the liquid injection hole gradually decrease. The sealing aluminum sheet 2 is fixed in the second groove 102, and the liquid injection pin is sealed and fixed in the liquid injection hole, thereby realizing a double sealing structure.

[0028] like Figure 1As shown, since the inner diameter of the injection hole is smaller than the inner diameter of the third groove 103, the plate-like structure below the positive electrode post 1 extends inward by a certain distance. This extended position is used to weld and fix it to the positive electrode current collector. When welding the positive electrode post 1 and the positive electrode current collector, first insert the laser welding head into the third groove 103, and then let the laser welding head weld the position of the positive electrode post 1 extending inward and the positive electrode current collector.

[0029] like Figure 2 As shown, the side of the sealing aluminum sheet 2 near the third groove 103 abuts against the side of the second groove 102 near the third groove 103, so that the second groove 102 supports the sealing aluminum sheet 2, thereby improving the pre-fixation firmness of the sealing aluminum sheet 2 and helping to improve the welding effect of the sealing aluminum sheet 2. At the same time, the side of the sealing aluminum sheet 2 away from the third groove 103 is flush with the side of the first groove 101 near the second groove 102. The welding position of the sealing aluminum sheet 2 and the positive electrode post 1 is away from the periphery of the first groove 101, thereby preventing the welding line of the sealing aluminum sheet 2 and the positive electrode post 1 from being higher than the top side of the positive electrode post 1, thus ensuring that the overall height of the battery is not affected.

[0030] like Figures 1-5 As shown, the outer edge of the sealing aluminum sheet 2 near the third groove 103 is provided with a chamfered surface 201, which reduces the outer diameter of the sealing aluminum sheet 2 near the third groove 103. This not only makes it easier for the end of the sealing aluminum sheet 2 near the third groove 103 to be inserted into the second groove 102, but also allows the sealing aluminum sheet 2 to be better guided into the second groove 102 by the sliding fit between the chamfered surface 201 and the side wall of the second groove 102, thereby improving the assembly efficiency and yield of the sealing aluminum sheet 2.

[0031] like Figure 2 As shown, the cross-section of the middle position of the sealing aluminum sheet 2 is the same as the cross-section of the third groove 103. The position on the sealing aluminum sheet 2 that extends out of the periphery of the third groove 103 is the protrusion 21. The protrusion 21 has an annular structure, and the chamfered surface 201 is provided on the protrusion 21.

[0032] like Figures 1-4 As shown, the angle between the chamfered surface 201 and the periphery of the second groove 102 is D1, the angle between the chamfered surface 201 and the side of the second groove 102 near the third groove 103 is D2, and the circumferential width of the protrusion 21 away from the third groove 103 is L. 321 The annular width of the protrusion 21 near the end of the third groove 103 is L. 421 The thickness of the sealing aluminum sheet 2 is H. 41 The distance between the sealing aluminum sheet 2 and the side of the third groove 103 furthest from the second groove 102 is H. 42 The length of the chamfered surface 201 along the thickness direction of the sealing aluminum sheet 2 is H. 402The outer diameter of the end of the sealing aluminum sheet 2 furthest from the third groove 103 is L. 41 The outer diameter of the sealing aluminum sheet 2 near the end of the third groove 103 is L. 42 The inner diameter of the first groove 101 is L. 43 The inner diameter of the third groove 103 is L. 44 .

[0033] In some embodiments, D1 = 26.87°-46.87°, that is, the angle between the chamfered surface 201 and the periphery of the second groove 102 is 26.87°, 36.87° or 46.87°, etc. If D1 < 26.87°, the angle between the chamfered surface 201 and the periphery of the second groove 102 is too small, the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is too large, the guiding effect of the chamfered surface 201 on the sealing aluminum sheet 2 is weakened, resulting in a decrease in battery assembly efficiency. If D1 > 46.87°, the angle between the chamfered surface 201 and the periphery of the second groove 102 is too large, the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is too small, the contact area between the sealing aluminum sheet 2 and the side of the second groove 102 near the third groove 103 is reduced, the sealing aluminum sheet 2 is prone to skew when installed in the second groove 102, and may even fall into the third groove 103, resulting in a decrease in the assembly yield of the sealing aluminum sheet 2.

[0034] In some embodiments, D2 = 43.13°-63.13°, that is, the angle between the chamfered surface 201 and the side of the second groove 102 near the third groove 103 is 43.13°, 53.13°, or 63.13°, etc. If D2 < 43.13°, the angle between the chamfered surface 201 and the side of the second groove 102 near the third groove 103 is too small, the length of the chamfered surface 201 along the thickness direction of the sealing aluminum sheet 2 is too small, the guiding effect of the chamfered surface 201 on the sealing aluminum sheet 2 is weakened, resulting in a decrease in battery assembly efficiency; if D2 > 63.13°, the angle between the chamfered surface 201 and the side of the second groove 102 near the third groove 103 is too large, the length of the chamfered surface 201 along the thickness direction of the sealing aluminum sheet 2 is too large, the processing difficulty of the sealing aluminum sheet 2 increases, the cost increases, and the yield decreases.

[0035] In some embodiments, L 321 =0.43-0.63mm, that is, the circumference width of the end of the protrusion 21 away from the third groove 103 is 0.43mm, 0.53mm or 0.63mm, etc.

[0036] In some embodiments, L 421 / L 321 =32.1%-43.4%, meaning the circumferential width of the protrusion 21 near the third groove 103 is 32.1%, 37.8%, or 43.4% of the circumferential width of the protrusion 21 away from the third groove 103, etc. If L 421 / L321 If the ratio is less than 32.1%, the annular width of the protrusion 21 near the third groove 103 is too small, reducing the contact area between the sealing aluminum sheet 2 and the side of the second groove 102 near the third groove 103. This results in insufficient support for the sealing aluminum sheet 2, making it prone to skew when inserted into the second groove 102, and it may even fall into the third groove 103, leading to a decrease in the assembly yield of the sealing aluminum sheet 2. 421 / L 321 If the diameter is greater than 43.4%, the annular width of the protrusion 21 near the third groove 103 is too large, the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is too large, the guiding effect of the chamfered surface 201 on the sealing aluminum sheet 2 is weakened, resulting in a decrease in battery assembly efficiency.

[0037] In some embodiments, H 41 =0.8-1.2mm, that is, the thickness of the sealing aluminum sheet 2 is 0.8mm, 1mm or 1.2mm, etc.

[0038] In some embodiments, H 402 / H 41 =35%-45%, meaning the length of the chamfered surface 201 along the thickness direction of the sealing aluminum sheet 2 is 35%, 40%, or 45% of the thickness of the sealing aluminum sheet 2, etc. If H 402 / H 41 If H < 35%, then the length of the chamfered surface 201 along the thickness direction of the sealing aluminum sheet 2 is too small, weakening the guiding effect of the chamfered surface 201 on the sealing aluminum sheet 2, resulting in a decrease in battery assembly efficiency; if H 402 / H 41 If the length of the chamfered surface 201 along the thickness direction of the sealing aluminum sheet 2 is too large, the processing difficulty of the sealing aluminum sheet 2 will increase, the cost will rise, and the yield will decrease.

[0039] In some embodiments, L 42 =11.2-11.6mm, that is, the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is 11.2mm, 11.4mm or 11.6mm, etc.

[0040] In some embodiments, L 42 / L 44 =101.8%-105.5%, meaning the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is 101.8%, 103.6%, or 105.5% of the inner diameter of the third groove 103, etc. If L 42 / L 44If the diameter of the sealing aluminum sheet 2 is less than 101.8%, the outer diameter of the end of the sealing aluminum sheet 2 near the third groove 103 is too small. This reduces the contact area between the sealing aluminum sheet 2 and the side of the second groove 102 near the third groove 103. When the sealing aluminum sheet 2 is installed in the second groove 102, it is prone to tilting, and may even fall into the third groove 103, resulting in a decrease in the assembly yield of the sealing aluminum sheet 2. 42 / L 44 If the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is too large, the guiding effect of the chamfered surface 201 on the sealing aluminum sheet 2 will be weakened, resulting in a decrease in the battery assembly efficiency.

[0041] In some embodiments, L 42 / L 41 =93.3%-96.7%, meaning the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is 93.3%, 95%, or 96.7% of the outer diameter of the sealing aluminum sheet 2 away from the third groove 103, etc. If L 42 / L 41 If the ratio is less than 93.3%, the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is too small, reducing the contact area between the sealing aluminum sheet 2 and the side of the second groove 102 near the third groove 103. This makes the sealing aluminum sheet 2 prone to misalignment when installed in the second groove 102, and it may even fall into the third groove 103, resulting in a decrease in the assembly yield of the sealing aluminum sheet 2. 42 / L 41 If the outer diameter of the sealing aluminum sheet 2 near the third groove 103 is too large, the guiding effect of the chamfered surface 201 on the sealing aluminum sheet 2 will be weakened, resulting in a decrease in the battery assembly efficiency.

[0042] In some embodiments, L 43 =12.5-14.5mm, that is, the inner diameter of the first groove 101 is 12.5mm, 13.5mm or 14.5mm, etc.

[0043] In some embodiments, H 42 =1.65-2.05mm, meaning the distance between the sealing aluminum sheet 2 and the side of the third groove 103 furthest from the second groove 102 is 1.65mm, 1.85mm, or 2.05mm, etc. If H 42 If the distance is less than 1.65mm, the gap between the sealing aluminum sheet 2 and the side of the third groove 103 furthest from the second groove 102 is too small. Under the premise of ensuring a constant height of the positive electrode post 1, the thickness of the area on the positive electrode post 1 used to assemble the sealing aluminum sheet 2 increases, and the thickness of the sealing aluminum sheet 2 also increases accordingly, leading to increased battery cost and weight, and decreased battery energy density. If H 42If the gap is greater than 2.05mm, the distance between the sealing aluminum sheet 2 and the side of the third groove 103 away from the second groove 102 is too large. Under the premise of ensuring that the height of the positive electrode post 1 is constant, the thickness of the position on the positive electrode post 1 used for assembling the sealing aluminum sheet 2 is reduced, and the thickness of the sealing aluminum sheet 2 will also be reduced. The structural strength of the sealing aluminum sheet is reduced. When welding the positive electrode post 1 and the busbar, the sealing aluminum sheet 2 is prone to deformation and welding defects such as incomplete welding may occur.

[0044] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A cylindrical secondary battery, characterized in that: The device includes a positive electrode post (1) and a sealing aluminum sheet (2). The positive electrode post (1) has a first groove (101), a second groove (102), and a third groove (103). The first groove (101) is located at one end of the positive electrode post (1). The first groove (101), the second groove (102), and the third groove (103) are coaxially arranged and connected in sequence. The inner diameters of the first groove (101), the second groove (102), and the third groove (103) gradually decrease. The sealing aluminum sheet (2) is fixed in the second groove (102) and abuts against the side of the second groove (102) near the third groove (103). The sealing aluminum sheet (2) has a chamfered surface (201) on the outer edge near the third groove (103). The chamfered surface (201) and the periphery of the second groove (102) form an angle D1, and the chamfered surface (201) and the second groove (102) near the third groove (103) form an angle D2. D1 = 26.87°-46.87°, D2 = 43.13°-63.13°.

2. The cylindrical secondary battery as described in claim 1, characterized in that: The sealing aluminum sheet (2) extends out of the periphery of the third groove (103) as a protrusion (21), the protrusion (21) is a ring structure, and the chamfered surface (201) is provided on the protrusion (21); The annular width of the protrusion (21) at the end away from the third groove (103) is L. 321 The annular width of the protrusion (21) near the end of the third groove (103) is L. 421 L 421 / L 321 =32.1%-43.4%.

3. A cylindrical secondary battery as described in claim 2, characterized in that: L 321 =0.43-0.63mm.

4. A cylindrical secondary battery as described in claim 1, characterized in that: The thickness of the sealing aluminum sheet (2) is H 41 The length of the chamfered surface (201) along the thickness direction of the sealing aluminum sheet (2) is H. 402 H 402 / H 41 =35%-45%.

5. A cylindrical secondary battery as described in claim 4, characterized in that: H 41 =0.8-1.2mm。 6. A cylindrical secondary battery as described in claim 1, characterized in that: The inner diameter of the third groove (103) is L. 44 The outer diameter of the sealing aluminum sheet (2) near the end of the third groove (103) is L. 42 L 42 / L 44 =101.8%-105.5%.

7. A cylindrical secondary battery as described in claim 6, characterized in that: The outer diameter of the end of the sealing aluminum sheet (2) away from the third groove (103) is L. 41 L 42 / L 41 =93.3%-96.7%.

8. A cylindrical secondary battery as described in claim 7, characterized in that: L 42 =11.2-11.6mm。 9. A cylindrical secondary battery as described in claim 8, characterized in that: The side of the sealing aluminum sheet (2) away from the third groove (103) is flush with the side of the first groove (101) near the second groove (102), and the inner diameter of the first groove (101) is L. 43 L 43 =12.5-14.5mm.

10. A cylindrical secondary battery as described in any one of claims 1-9, characterized in that: The distance between the sealing aluminum sheet (2) and the side of the third groove (103) away from the second groove (102) is H. 42 H 42 =1.65-2.05mm.

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