Battery pressure relief structure and cylindrical battery

Abstract

The utility model discloses a battery pressure relief structure and a cylindrical battery, the battery pressure relief structure comprises an end plate located at one end of a battery shell and a sealing nail integrally in a circular sheet shape, the outer side of the end plate is coaxially provided with a sunken welding sinking table, and the middle part of the welding sinking table is provided with a liquid injection hole which is concentrically arranged in a penetrating manner; the diameter of the sealing nail is consistent with that of the welding sinking table, and the thickness of the sealing nail is matched with the depth of the welding sinking table; the middle of the sealing nail is concave inwards to form a pressure relief area with the thickness reduced, and the pressure relief area is provided with an anti-explosion nick which is integrally arranged in a C shape. The utility model has the advantages that the structure is simple and reasonable, the number of parts can be reduced, the processing procedure is simplified, and the production efficiency is improved.

Description

Technical Field

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

[0002] Commercial lithium-ion batteries can be classified into three categories according to their packaging form: prismatic, cylindrical, and pouch. Among them, large cylindrical batteries have become a hot topic in the battery industry in recent years, especially in the fields of electric vehicles and energy storage. This type of battery design has attracted attention due to its high energy density, excellent rate performance, and good safety performance. All-tab technology is a key feature of large cylindrical batteries. By placing current collectors across the entire surface of the electrodes, it significantly reduces the battery's internal resistance, thereby improving the battery's charge and discharge efficiency. The all-tab design makes the maximum current transmission distance the height of the electrode rather than its length, which is typically only 5% to 20% of the electrode length. Therefore, the resistance is reduced by 5 to 20 times compared to single-tab batteries. This design not only improves the battery's rate performance but also helps improve battery safety because there are no concentrated heat points inside the battery; heat is evenly distributed throughout the battery pack, offering advantages in thermal management. High-rate discharge is another significant characteristic of large cylindrical batteries. High-rate batteries can provide faster charging speeds and higher power output, which is particularly important for applications requiring rapid charging and discharging. For example, some high-rate batteries can support fast charging from 0 to 80% in a short time, which is of great significance for improving the charging convenience and practicality of electric vehicles.

[0003] To improve the safety performance of cylindrical batteries, an explosion-proof valve is usually installed on the casing. When the internal pressure of the casing reaches a pressure threshold, the explosion-proof valve opens to release pressure. In the current technology, the battery's electrolyte filling port and explosion-proof valve are usually set separately and independently, resulting in a large number of parts, a complex assembly process, and low production efficiency. Utility Model Content

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to provide a battery pressure relief structure and cylindrical battery with a simple and reasonable structure that can reduce the number of parts, simplify the processing steps, and improve production efficiency.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A battery pressure relief structure includes a pressure relief end plate located at one end of the battery casing and a sealing pin that is generally circular. The outer side of the pressure relief end plate is coaxially provided with a recessed welding platform, and the center of the welding platform has a concentrically through-hole for liquid injection. The diameter of the sealing pin is the same as the diameter of the welding platform, and the thickness matches the depth of the welding platform. The center of the sealing pin is recessed to form a pressure relief area with reduced thickness, and the pressure relief area has explosion-proof markings that are generally C-shaped.

[0007] In the above structure, the explosion-proof markings are directly set in the middle of the circular sealing pin, forming an integrated structure of the sealing pin and the pressure relief valve, thereby reducing the number of parts. After the battery is filled with electrolyte through the filling hole, the sealing pin is welded to the welding platform to complete the assembly of the sealing pin and the explosion-proof valve. This reduces the cost of raw materials, reduces processing steps, and improves processing efficiency.

[0008] Furthermore, the bottom of the welding platform has a concave, thinned penetration welding platform, the diameter of which is smaller than the diameter of the welding platform.

[0009] In this way, by setting a thinned through-weld countersunk at the bottom of the welding countersunk, the pressure relief end plate can be welded to the core or busbar through the through-weld countersunk. In addition, making the diameter of the through-weld countersunk smaller than the diameter of the welding countersunk creates a gap between the sealing pin and the through-weld countersunk, reducing the heat conduction area between the sealing pin and the pressure relief end plate, and also creating a larger space in the pressure relief area, ensuring that the pressure relief area has a stable stress area and ensuring reliable pressure relief.

[0010] Furthermore, the inner side of the pressure relief end plate has a coaxially protruding welding boss, the diameter of which is larger than the diameter of the through-welding countersink.

[0011] In this way, by welding the boss, the inner side of the through-welding platform can be more reliably attached to the core or busbar, thereby ensuring the reliability of the through-welding and improving the yield rate.

[0012] Furthermore, the outer side of the welding platform has a concentrically arranged film-coated platform on which a protective film can be pasted to cover the welding platform.

[0013] Furthermore, the cross-sectional shape of the explosion-proof groove is rectangular or trapezoidal.

[0014] Furthermore, the battery housing includes an outer shell with an opening at at least one end, and the pressure relief end plate is a cover plate that fits into the opening of the outer shell.

[0015] Furthermore, the battery housing includes an outer shell with one end open, and the pressure relief plate is integrally formed on the outer shell.

[0016] Furthermore, the pressure relief area has a pre-pressure relief section that protrudes outward in a spherical shape, and the pre-pressure relief section is located within the explosion-proof groove.

[0017] Furthermore, the explosion-proof grooves extend along the edge of the pre-depression section.

[0018] A cylindrical battery, including the battery pressure relief structure described above.

[0019] In summary, this utility model has the advantages of simple and reasonable structure, reducing the number of parts, simplifying processing procedures, and improving production efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this embodiment.

[0021] Figure 2 This is a cross-sectional structural diagram of this embodiment.

[0022] Figure 3 and Figure 4 They are respectively Figure 2 A partially enlarged structural diagram.

[0023] Figure 5 This is an exploded view of the sealing nail portion in this embodiment.

[0024] Figure 6 This is a cross-sectional view of the sealing nail portion in this embodiment.

[0025] Figure 7 This is an overall exploded view of this embodiment. Detailed Implementation

[0026] The present invention will be further described in detail below using a cylindrical battery with the structure of the present invention.

[0027] In practical implementation: such as Figures 1 to 7 As shown, a cylindrical battery includes a cylindrical housing 1 and a winding core assembly 2 disposed within the housing 1. The housing 1 has a terminal end plate and a pressure relief end plate at its two ends. The terminal end plate has a terminal assembly 3 welded to the winding core assembly 2. A recessed welding platform 11 is coaxially disposed on the outer side of the pressure relief end plate. A liquid injection hole 12 is concentrically disposed in the center of the welding platform 11. A circular sealing pin 4 is fitted onto the welding platform 11. The center of the sealing pin 4 is recessed to form a thinned pressure relief area 41. The pressure relief area 41 has an explosion-proof groove 42 that is C-shaped. Specifically, the terminal end plate is integrally formed on the housing 1, and the pressure relief end plate is a cover plate welded to the housing 1.

[0028] The bottom of the welding countersunk 11 has a concave, thinned through-welding countersunk 13, the diameter of which is smaller than the diameter of the welding countersunk 11. By providing a thinned through-welding countersunk at the bottom of the welding countersunk, the pressure relief end plate and the core assembly can be welded together. Furthermore, by making the diameter of the through-welding countersunk smaller than the diameter of the welding countersunk, a gap is formed between the sealing pin and the through-welding countersunk, reducing the heat conduction area between the sealing pin and the pressure relief end plate. This also allows for a larger space in the pressure relief area, ensuring a stable stress area and reliable pressure relief. Simultaneously, the pressure relief area 41 has an outwardly protruding, spherical pre-pressure relief portion located within the explosion-proof notch 42; the explosion-proof notch 42 extends along the edge of the pre-pressure relief portion. By arranging the pre-pressure relief portion outwardly in a spherical shape, the internal space of the pressure relief area can be further increased.

[0029] The pressure relief end plate has a coaxially protruding welding boss 14 on its inner side, the diameter of which is larger than the diameter of the through-welding countersunk plate 13. The outer side of the welding countersunk plate 11 has a concentrically arranged film-coating countersunk plate 15, on which a protective film can be adhered to cover the welding countersunk plate 11. The welding boss allows the inner side of the through-welding countersunk plate to more reliably adhere to the core assembly, thereby ensuring the reliability of the through-welding and improving the yield rate.

[0030] In this embodiment, the core assembly 2 includes a core 21, with a first busbar 22 and a second busbar 23 welded to both ends of the core 21, respectively; the pole assembly 3 is welded to the first busbar 22; and the inner side of the pressure relief end plate is welded to the second busbar 23. The pole end plate has a coaxially through mounting hole in its center. The pole assembly 3 includes a pole 31 riveted to the mounting hole, with an insulating sealing ring 32 fitted between the pole 31 and the mounting hole. A lower insulating pad 33, concentrically connected to the sealing ring 32, is placed between the inward-facing end of the pole 31 and the pole end plate. The diameter of the lower insulating pad 33 is larger than the diameter of the first busbar 22. An upper insulating pad 34, concentrically connected to the sealing ring 32, is placed between the other end of the pole 31 and the pole end plate. The diameter of the upper insulating pad 34 matches the outer diameter of the pole 31.

[0031] The pole end plate has a coaxial through mounting hole in the middle. The pole assembly 3 includes a pole 31 riveted to the mounting hole. An insulating sealing ring 32 is sleeved between the pole 31 and the mounting hole. A lower insulating pad 33, which is concentrically connected to the sealing ring 32, is placed between the inward end of the pole 31 and the pole end plate. The diameter of the lower insulating pad 33 is larger than the diameter of the first busbar 22. An upper insulating pad 34, which is concentrically connected to the sealing ring 32, is placed between the other end of the pole 31 and the pole end plate. The diameter of the upper insulating pad 34 matches the outer diameter of the pole 31.

[0032] In this embodiment, the pole post 31 includes a lower pole post 313 and an annular upper pole post 314. The lower end of the lower pole post 313 has a riveting disc that protrudes radially outward, and the upper end passes through the upper pole post 314 and is riveted together. The first busbar 22 includes a conductive handle that extends radially. The end of the conductive handle away from the first busbar 22 has a through riveting hole. The riveting hole is fitted onto the lower pole post 313 and riveted between the riveting disc and the lower insulating pad 34.

[0033] In the above structure, the explosion-proof markings are directly set in the middle of the circular sealing pin, forming an integrated structure of the sealing pin and the pressure relief valve, thereby reducing the number of parts. After the battery is filled with electrolyte through the filling hole, the sealing pin is welded to the welding platform to complete the assembly of the sealing pin and the explosion-proof valve. This reduces the cost of raw materials, reduces processing steps, and improves processing efficiency.

[0034] 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 and improvements 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 battery pressure relief structure, characterized in that, The device includes a pressure relief end plate located at one end of the battery casing and a sealing pin (4) that is circular in shape. A recessed welding platform (11) is coaxially provided on the outer side of the pressure relief end plate. The center of the welding platform (11) has a liquid injection hole (12) that is concentrically and through. The diameter of the sealing pin (4) is the same as the diameter of the welding platform (11), and the thickness matches the depth of the welding platform (11). The center of the sealing pin (4) is recessed to form a pressure relief area (41) with reduced thickness. The pressure relief area (41) has explosion-proof grooves (42) that are C-shaped in shape.

2. The battery pressure relief structure as described in claim 1, characterized in that, The bottom of the welding platform (11) has a concave through-welding platform (13) with reduced thickness, the diameter of which is smaller than that of the welding platform (11).

3. The battery pressure relief structure as described in claim 2, characterized in that, The inner side of the pressure relief end plate has a coaxially protruding welding boss (14), the diameter of which is larger than the diameter of the through welding sink (13).

4. The battery pressure relief structure as described in any one of claims 1 to 3, characterized in that, The welding platform (11) has a concentrically arranged film-coated platform (15) on its outer side, and a protective film can be pasted on the film-coated platform (15) to cover the welding platform (11).

5. The battery pressure relief structure as described in claim 1, characterized in that, The cross-sectional shape of the explosion-proof markings is rectangular or trapezoidal.

6. The battery pressure relief structure as described in claim 1, characterized in that, The battery casing includes an outer shell with an opening at at least one end, and the pressure relief end plate is a cover plate that fits into the opening of the outer shell.

7. The battery pressure relief structure as described in claim 1, characterized in that, The battery casing includes an outer shell with one end open, and the pressure relief plate is integrally formed on the outer shell.

8. The battery pressure relief structure as described in claim 1, characterized in that, The pressure relief zone (41) has a pre-pressure relief section that protrudes outward in a spherical shape and is located within the explosion-proof groove (42).

9. The battery pressure relief structure as described in claim 8, characterized in that, The explosion-proof groove (42) extends along the edge of the pre-depressurization section.

10. A cylindrical battery, characterized in that, Includes the battery pressure relief structure as described in any one of claims 1 to 9.

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