Sealing structure for liquid injection hole and liquid injection nail of lithium ion battery

Abstract

The utility model relates to a sealing structure for a liquid injection hole and a liquid injection nail of a lithium ion battery, which comprises a cover plate assembly, a pole is arranged above the cover plate assembly, the pole comprises the liquid injection hole, a through hole is arranged below the liquid injection hole, the through hole is connected with the inside of the lithium ion battery, a liquid injection bead is arranged in the liquid injection hole, and the liquid injection hole and the liquid injection bead form the sealing structure. A fluororubber sealing ring is mounted at the bottom of the liquid injection hole; the liquid injection bead and the fluororubber sealing ring form a first mechanical seal, and the liquid injection hole and the liquid injection bead are in interference fit to form a second structural seal; and the boss is arranged on the surface of the pole and above the liquid injection hole. The fluororubber sealing washer is arranged, the liquid injection bead and the fluororubber sealing ring form a first mechanical seal, the liquid injection hole and the liquid injection bead are in interference fit to form a second structural seal, meanwhile, in the process that the liquid injection bead is squeezed into the liquid injection hole, it is guaranteed that the contact area of the liquid injection bead and the liquid injection hole is increased, and the sealing performance is greatly improved.

Description

Technical Field

[0001] The utility model relates to a sealing structure of a liquid injection hole and a liquid injection nail of a lithium ion battery. Background Art

[0002] Lithium-ion batteries are increasingly widely used in various fields. In the production and application of lithium-ion batteries, the battery filling hole often has poor leakage at the enterprise end, resulting in the scrapping of the entire battery cell, production line shutdown, idleness and waste of personnel, and waste of personnel production costs. At the customer application end, the battery cannot work due to leakage problems, the entire battery pack is short-circuited, the exterior of the lithium battery is deformed, the volume of the lithium battery expands, and even some cracks appear on the battery shell, causing the air to smell irritating and toxic gases, affecting people's life and health.

[0003] At present, lithium batteries often use liquid injection nail laser sealing welding and special liquid injection rivets. Laser sealing welding is more commonly used in low-capacity types. When used in high-capacity types, the welding position is prone to cracks due to the high internal air pressure of the lithium battery, affecting the overall lithium battery leakage performance. When the battery is injected with electrolyte, electrolyte crystals are likely to remain in the layer pores and on the surface of the orifice. During laser sealing welding, the position where the electrolyte crystals are present is prone to explosion, resulting in cracks, which makes it impossible to fully seal. There are many potential leakage channels, which poses a risk of leakage and affects the safety of battery use. Special liquid injection rivets are costly to use, complex to process, and have high processing precision. After processing, the surface of the liquid injection nails is raised, which increases the cost of battery group production.

[0004] In order to solve the above problems, the present utility model is hereby proposed. Utility Model Content

[0005] The utility model aims to provide a sealing structure for a liquid injection hole and a liquid injection nail of a lithium ion battery.

[0006] The above purpose is achieved by the following technical solutions:

[0007] A sealing structure for a liquid injection hole and a liquid injection nail of a lithium ion battery comprises a cover plate assembly, a pole is arranged above the cover plate assembly, the pole comprises a liquid injection hole, a through hole is arranged below the liquid injection hole, the through hole is connected to the inside of the lithium ion battery, a liquid injection bead is arranged in the liquid injection hole, the liquid injection hole and the liquid injection bead form a sealing structure through interference fit, and a fluororubber sealing ring is installed at the bottom of the liquid injection hole.

[0008] Preferably, the injection bead and the fluororubber sealing ring form a first mechanical seal, and the injection hole and the injection bead are interference fit to form a second structural seal.

[0009] Furthermore, it also includes a boss, which is installed on the surface of the pole and above the injection hole.

[0010] Preferably, the thickness of the boss is 1-1.5 mm.

[0011] Preferably, the injection beads are ceramic beads, aluminum beads or steel beads.

[0012] Beneficial technical effects:

[0013] The utility model provides a fluororubber sealing gasket, forms a first mechanical seal through the injection bead and the fluororubber sealing ring, and forms a second structural seal through interference fit between the injection hole and the injection bead. At the same time, during the process of the injection bead squeezing into the injection hole, residual electrolyte crystals on the inner surface of the injection hole can be separated from the hole wall of the injection hole 3, ensuring that the contact area between the injection bead and the injection hole is increased, thereby greatly improving the sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The utility model will be further described below in conjunction with the accompanying drawings.

[0015] Figure 1 The utility model is a schematic diagram of the process of installing the boss of the sealing structure of the lithium-ion battery injection hole and the injection nail.

[0016] Figure 2 The utility model is a schematic diagram of the sealing structure of the liquid injection hole and the liquid injection nail of the lithium ion battery.

[0017] The numbers in the figure are: 1, pole; 2, injection bead; 3, injection hole; 4, sealing hob; 5, cover plate assembly; 6, through hole; 7, boss; 8, fluororubber sealing gasket. DETAILED DESCRIPTION

[0018] Reference Figure 1-Figure 2 As shown, a sealing structure of a lithium-ion battery injection hole and injection nail includes a cover plate assembly 5, a pole 1 is arranged above the cover plate assembly 5, the pole 1 includes an injection hole 3, a through hole 6 is arranged below the injection hole 3, the through hole 6 is connected to the inside of the lithium-ion battery, an injection bead 2 is arranged in the injection hole 3, the injection hole 3 and the injection bead 2 form a sealing structure through interference fit, a fluororubber sealing ring 8 is installed at the bottom of the injection hole 3, the injection bead 2 and the fluororubber sealing ring 8 form a first mechanical seal, and the injection hole 3 and the injection bead 2 form a second structural seal through interference fit. At the same time, in the process of squeezing the injection bead 2 into the injection hole 3, the residual electrolyte crystals on the inner surface of the injection hole 3 can be separated from the hole wall of the injection hole 3, ensuring that the contact area between the injection bead 2 and the injection hole 3 is increased, thereby greatly improving the sealing performance.

[0019] The injection beads 2 are selected from ceramic beads, aluminum beads or steel beads.

[0020] It also includes a boss 7, which is installed on the surface of the pole 1 and above the injection hole 3. The thickness of the boss 7 is 1-1.5mm. Due to the 1-1.5mm boss designed on the surface of the pole 1, the boss 7 is filled into the injection hole 3 through the thrust of the sealing roller 4 of the pole 1, thereby ensuring the flatness of the surface of the pole 1, enhancing the sealing force of the injection bead 2, and ensuring that the sealing performance of the injection bead 2 is improved in high internal air pressure, effectively avoiding the risk of leakage, and improving the safety of the battery.

[0021] When in use, the injection bead 2 is installed in the injection hole 3 of the pole 1 with an interference fit, and the injection bead 2 and the fluororubber sealing gasket 8 are squeezed with external pressure equipment to form plastic deformation, so that the fluororubber sealing gasket 8 fills the internal space of the pole 1 to achieve mechanical sealing performance, which is the first seal of the injection hole 3. The injection bead 2 and the pole hole 1 have an interference fit, and the internal contact surface is precisely matched, so that the injection bead 2 and the pole 1 achieve self-sealing performance between the parts, which is the second seal of the injection hole 3.

[0022] After meeting the above assembly process, the sealing hob 4 of the pole 1 and the boss 7 of the pole 1 are processed and sealed to allow the boss 7 of the pole 1 to be filled with the injection hole 3, ensuring that the injection bead 2 and the injection hole 3 cooperate stably to achieve a safe and stable sealing effect. This sealing structure of the lithium-ion battery injection hole and injection nail can control the sealing performance defects of the battery injection port through two sealings to meet the safety of battery use.

[0023] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A sealing structure for a lithium-ion battery injection hole and injection nail, comprising a cover plate assembly (5), characterized in that: A pole (1) is arranged above the cover plate assembly (5), the pole (1) includes a liquid injection hole (3), a through hole (6) is arranged below the liquid injection hole (3), the through hole (6) is connected to the inside of the lithium-ion battery, a liquid injection bead (2) is arranged in the liquid injection hole (3), the liquid injection hole (3) and the liquid injection bead (2) form a sealing structure through interference fit, and a fluororubber sealing ring (8) is installed at the bottom of the liquid injection hole (3); The liquid injection bead (2) and the fluororubber sealing ring (8) form a first mechanical seal, and the liquid injection hole (3) and the liquid injection bead (2) form a second structural seal by using interference fit.

2. The sealing structure of the lithium-ion battery injection hole and injection nail according to claim 1, characterized in that: It also includes a boss (7), which is installed on the surface of the pole (1) and above the liquid injection hole (3).

3. The sealing structure of the lithium-ion battery injection hole and injection nail according to claim 2, characterized in that: The thickness of the boss (7) is 1-1.5 mm.

4. The sealing structure of the lithium-ion battery injection hole and injection nail according to claim 1, characterized in that: The liquid injection beads (2) are selected from ceramic beads, aluminum beads or steel beads.

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