Cylindrical battery with liquid injection and pressure relief integrated structure

Abstract

The utility model discloses a cylindrical battery with a liquid injection and pressure relief integrated structure, which comprises a cylindrical shell and a roll core component arranged in the shell, two ends of the shell are respectively provided with a first end plate and a second end plate, the first end plate is provided with a pole component connected with the roll core component in a welding manner, and the second end plate is provided with a pole component connected with the roll core component in a welding manner. A sunken welding sinking table is coaxially arranged on the outer side of the second end plate, and a liquid injection hole is formed in the middle of the welding sinking table in a concentric penetrating mode. A sealing nail in a circular sheet shape is arranged on the welding sinking table in a matched mode, the middle of the sealing nail is concaved inwards to form a pressure relief area with the thickness reduced, and an anti-explosion nick which is integrally arranged in a C shape is formed in the pressure relief area. The utility model has the advantages that the structure is simple and reasonable, the number of parts can be reduced, the assembly process is simplified, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to cylindrical lithium battery technical field, especially a cylindrical battery with liquid injection and pressure relief integrated structure. BACKGROUND

[0002] Commercial lithium ion batteries can be divided into three categories according to the packaging form, namely square, cylindrical and soft package, among which the large cylindrical battery in the cylindrical battery is a hot spot in the battery industry in recent years, especially in the field of electric vehicles and energy storage. The design of such battery is concerned for its high energy density, excellent rate performance and good safety performance. The full tab technology is a key feature of the large cylindrical battery, which significantly reduces the internal resistance of the battery by setting current collectors on the surface of the entire electrode, thereby improving the charge and discharge efficiency of the battery. The full tab design makes the maximum distance of current transmission become the height of the electrode instead of the length, which is usually only 5%~20% of the electrode length, so the resistance is reduced by 5~20 times compared with the single tab. This design not only improves the rate performance of the battery, but also helps to improve the safety of the battery, because the full tab has no concentrated heating point inside the battery, and the heat is evenly distributed inside, which has an advantage in heat management for the whole battery. High-rate discharge is another significant feature of large cylindrical batteries. High-rate batteries can provide faster charging speed and higher power output, which is particularly important for application scenarios that require fast 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 to improve the charging convenience and practicality of electric vehicles.

[0003] In order to improve the safety performance of the cylindrical battery, an explosion-proof valve is usually provided on the shell, which is opened to achieve pressure relief when the pressure inside the shell reaches the pressure threshold. In the prior art, the liquid injection hole and the explosion-proof valve of the battery are usually separately and independently arranged, which has many parts and requires multiple assembly processes, resulting in low production efficiency. UTILITY MODEL CONTENTS

[0004] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a cylindrical battery with liquid injection and pressure relief integrated structure, which has simple and reasonable structure, can reduce the number of parts, is beneficial to simplify the assembly process and improve the production efficiency.

[0005] In order to solve the above technical problems, the utility model adopts the following technical scheme:

[0006] A cylindrical battery with an integrated liquid injection and pressure relief structure, comprising a cylindrical shell and a roll core assembly arranged in the shell, the shell having a first end plate and a second end plate at both ends, the first end plate having a pole assembly welded to the roll core assembly, the second end plate having a recessed welding pad coaxially arranged outside, the welding pad having a concentric through hole in the middle, the welding pad having a circular sheet-shaped sealing nail, the middle of the sealing nail being concave to form a pressure relief area with reduced thickness, the pressure relief area having a C-shaped anti-explosion notch.

[0007] In the above structure, the anti-explosion notch is directly arranged in the middle of the circular sheet-shaped sealing nail, forming an integrated structure of the sealing nail and the pressure relief valve, thereby reducing the number of parts. After completing the liquid injection of the battery through the liquid injection hole, the sealing nail is welded on the welding pad, which can complete the assembly of the sealing nail and the pressure relief valve, thereby reducing the cost of raw materials, reducing the processing procedure and improving the processing efficiency.

[0008] Further, the bottom of the welding pad has a through-welding pad with reduced thickness, and the diameter of the through-welding pad is smaller than that of the welding pad.

[0009] In this way, the second end plate and the roll core assembly are welded by the through-welding pad arranged at the bottom of the welding pad. In addition, the diameter of the through-welding pad is smaller than that of the welding pad, so that a gap is formed between the sealing nail and the through-welding pad, the heat conduction area between the sealing nail and the second end plate is reduced, and a larger space is formed at the pressure relief area, ensuring that the pressure relief area has a stable stress area and ensuring reliable pressure relief.

[0010] Further, the inner side of the second end plate has a coaxially protruding welding boss, and the diameter of the welding boss is larger than that of the through-welding pad.

[0011] In this way, the welding boss can make the inner side of the position where the through-welding pad is located more reliably adhere to the roll core assembly, thereby ensuring the reliability of the through-welding and improving the yield.

[0012] Further, the outer side of the welding pad has a concentricly arranged film sticking pad, and the film sticking pad can stick a protective film covering the welding pad.

[0013] Further, the pressure relief area has a pre-pressure relief part protruding outward in the form of a spherical cap, and the pre-pressure relief part is located in the anti-explosion notch.

[0014] Further, the anti-explosion notch is arranged along the edge of the pre-pressure relief part.

[0015] Further, the winding core assembly comprises a winding core, two ends of the winding core are welded with a first busbar and a second busbar respectively; the pole column assembly is welded with the first busbar; the inner side of the second end plate is welded with the second busbar.

[0016] Further, the middle part of the first end plate is provided with a mounting hole arranged coaxially and through, the pole column assembly comprises a pole column riveted on the mounting hole, an insulating sealing ring is sleeved between the pole column and the mounting hole; the lower end of the pole column towards the inside is padded with a lower insulating pad arranged concentrically and connected with the sealing ring between the pole column and the first end plate, the diameter of the lower insulating pad is larger than the diameter of the first busbar; the other end of the pole column is padded with an upper insulating pad arranged concentrically and connected with the sealing ring between the pole column and the first end plate, the diameter of the upper insulating pad matches the diameter of the outer end of the pole column.

[0017] Further, the pole column comprises an upper column body and a lower column body which are both annular, the upper column body and the lower column body are mutually buckled and riveted on the first end plate; the middle part of the first busbar is provided with a center hole arranged through, the edge of the center hole is provided with a welding flange protruding towards the pole column, the outer diameter of the welding flange matches the inner hole diameter of the lower column body, and the welding flange is welded on the pole column; the inner hole of the upper column body is welded with a sealing plug.

[0018] Further, the pole column comprises a lower pole column and an upper pole column which is annular, the lower end of the lower column body is provided with a riveting disc protruding radially and outwardly, the upper end penetrates through the upper pole column and is riveted and connected; the first busbar comprises a conductive handle arranged in the radial direction, one end of the conductive handle away from the first busbar is provided with a riveting hole arranged through, the riveting hole is cooperatively sleeved on the lower column body and is riveted between the riveting disc and the lower insulating pad.

[0019] In summary, the utility model has the advantages of simple and reasonable structure, can reduce the number of parts, is favorable for simplifying the assembly process, improving production efficiency and the like. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of example 1.

[0021] Figure 2 It is a schematic diagram of the sectional structure of example 1.

[0022] Figure 3 And Figure 4 It is a schematic diagram of the sectional structure of example 1. Figure 2 It is a schematic diagram of the sectional structure of example 1.

[0023] Figure 5 It is an exploded schematic diagram of the sealing nail part in example 1. It is a schematic diagram of the sectional structure of example 1.

[0024] Figure 6 This is a cross-sectional view of the sealing nail portion in Example 1.

[0025] Figure 7 This is an overall exploded view of Example 1.

[0026] Figure 8 This is an overall exploded view of Example 2. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the embodiments.

[0028] Example 1: As Figures 1-7 As shown, a cylindrical battery with an integrated liquid injection and pressure relief structure includes a cylindrical housing 1 and a winding core assembly 2 disposed within the housing 1. The housing 1 has a first end plate and a second end plate at its two ends. The first end plate has an electrode assembly 3 welded to the winding core assembly 2. A recessed welding platform 11 is coaxially disposed on the outer side of the second 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 pressure relief area 41 with reduced thickness. The pressure relief area 41 has C-shaped explosion-proof markings 42. Specifically, the first end plate is integrally formed on the housing 1, and the second end plate is a cover plate welded to the housing 1.

[0029] 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 second end plate can be welded to the core assembly. 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 second end plate. This also allows for a larger space in the pressure relief zone, ensuring a stable stress area and reliable pressure relief. Simultaneously, the pressure relief zone 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 zone can be further increased.

[0030] The inner side of the second end plate is provided with a coaxially protruding welding boss 14, the diameter of the welding boss 14 is greater than the diameter of the penetration welding sink 13; the outer side of the welding sink 11 is provided with a concentric film sink 15, and the protective film covering the welding sink 11 can be pasted on the film sink 15. The penetration welding sink can be more reliably attached to the core assembly on the inner side of the penetration welding sink, thereby ensuring the reliability of the penetration welding, and improving the yield.

[0031] In the embodiment, the core assembly 2 includes a core 21, and the two ends of the core 21 are respectively welded with a first bus bar 22 and a second bus bar 23; the pole column assembly 3 is welded and connected with the first bus bar 22; and the inner side of the second end plate is welded and connected with the second bus bar 23. The middle part of the first end plate is provided with a coaxially penetrating mounting hole, the pole column assembly 3 includes a pole column 31 riveted on the mounting hole, and an insulating sealing ring 32 is sleeved between the pole column 31 and the mounting hole; a lower insulating pad 33 concentrically connected with the sealing ring 32 is arranged between the inner end of the pole column 31 and the first end plate, and the diameter of the lower insulating pad 33 is greater than the diameter of the first bus bar 22; and an upper insulating pad 34 concentrically connected with the sealing ring 32 is arranged between the other end of the pole column 31 and the first end plate, and the diameter of the upper insulating pad 34 matches the outer end diameter of the pole column 31.

[0032] The middle part of the first end plate is provided with a coaxially penetrating mounting hole, the pole column assembly 3 includes a pole column 31 riveted on the mounting hole, and an insulating sealing ring 32 is sleeved between the pole column 31 and the mounting hole; a lower insulating pad 33 concentrically connected with the sealing ring 32 is arranged between the inner end of the pole column 31 and the first end plate, and the diameter of the lower insulating pad 33 is greater than the diameter of the first bus bar 22; and an upper insulating pad 34 concentrically connected with the sealing ring 32 is arranged between the other end of the pole column 31 and the first end plate, and the diameter of the upper insulating pad 34 matches the outer end diameter of the pole column 31.

[0033] In the embodiment, the pole column 31 includes a lower pole column 313 and a circular ring-shaped upper pole column 314, the lower end of the lower pole column 313 is provided with a riveting disc protruding outward in the radial direction, and the upper end penetrates through the upper pole column 314 and is riveted and connected; the first bus bar 22 includes a conductive handle extending in the radial direction, and the end of the conductive handle away from the first bus bar 22 is provided with a penetrating riveting hole, the riveting hole is sleeved on the lower pole column 313 in a matching manner, and is riveted between the riveting disc and the lower insulating pad 33.

[0034] In the structure, the explosion-proof notch is directly arranged in the middle of the sealing nail in a disc shape, an integrated structure of the sealing nail and the pressure relief valve is formed, thereby reducing the number of parts. After liquid injection is completed through the liquid injection hole, the sealing nail is welded on the welding sink in cooperation, assembly of the sealing nail and the pressure relief valve is completed, raw material cost is reduced, processing procedures are reduced, and processing efficiency is improved.

[0035] Embodiment 2: The main difference between this embodiment and embodiment 1 is that, as shown in Figure 8 The first bus bar 22 has a center hole in the middle, the edge of the center hole has a welding flange which is protrudingly arranged towards the pole 31, the outer diameter of the welding flange matches the inner hole diameter of the lower pole body 312, and the welding flange is welded on the pole 31; the inner hole of the upper pole body 311 has a sealing plug 35 welded thereon.

[0036] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cylindrical battery with an integrated liquid injection and pressure relief structure, characterized in that, The device includes a cylindrical shell (1) and a core assembly (2) disposed within the shell (1). The shell (1) has a first end plate and a second end plate at its two ends. The first end plate has a pole assembly (3) welded to the core assembly (2). The second end plate has a recessed welding platform (11) coaxially disposed on its outer side. The welding platform (11) has a concentrically through-hole (12) in the middle. The welding platform (11) is fitted with a circular sealing nail (4). The sealing nail (4) has a recessed center forming a pressure relief area (41) with reduced thickness. The pressure relief area (41) has an explosion-proof groove (42) that is C-shaped.

2. The cylindrical battery with an integrated liquid injection and 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 cylindrical battery with an integrated liquid injection and pressure relief structure as described in claim 2, characterized in that, The inner side of the second end plate has a coaxially protruding welding boss (14), the diameter of which is larger than the diameter of the through welding sinker (13).

4. The cylindrical battery with an integrated liquid injection and 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 cylindrical battery with an integrated liquid injection and 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).

6. The cylindrical battery with an integrated liquid injection and pressure relief structure as described in claim 5, characterized in that, The explosion-proof groove (42) extends along the edge of the pre-depressurization section.

7. The cylindrical battery with an integrated liquid injection and pressure relief structure as described in claim 1, characterized in that, The core assembly (2) includes a core (21), and a first busbar (22) and a second busbar (23) are welded to both ends of the core (21); the pole assembly (3) is welded to the first busbar (22); and the inner side of the second end plate is welded to the second busbar (23).

8. The cylindrical battery with an integrated liquid injection and pressure relief structure as described in claim 7, characterized in that, The first 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) is provided between the inward end of the pole (31) and the first end plate, and is concentrically connected with the sealing ring (32). The diameter of the lower insulating pad (33) is larger than the diameter of the first busbar (22). An upper insulating pad (34) is provided between the other end of the pole (31) and the first end plate, and is concentrically connected with the sealing ring (32). The diameter of the upper insulating pad (34) matches the outer diameter of the pole (31).

9. The cylindrical battery with an integrated liquid injection and pressure relief structure as described in claim 8, characterized in that, The pole post (31) includes an upper post (311) and a lower post (312) that are both circular. The upper post (311) and the lower post (312) are riveted to the first end plate in a snap-fit ​​manner. The first busbar (22) has a through-hole in the middle. The edge of the central hole has a welding flange that protrudes toward the pole post (31). The outer diameter of the welding flange matches the inner diameter of the lower post (312) and is welded onto the pole post (31). A sealing plug (35) is welded onto the inner hole of the upper post (311).

10. The cylindrical battery with an integrated liquid injection and pressure relief structure as described in claim 8, characterized in that, The pole (31) includes a lower pole (313) and an annular upper pole (314). The lower end of the lower pole (313) has a riveting disc that protrudes radially outward, and the upper end passes through the upper pole (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 (313) and riveted between the riveting disc and the lower insulating pad (33).

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