Lithium ion battery negative pressure formation nozzle

Abstract

The utility model provides a kind of lithium ion battery negative pressure formation suction nozzle, suction nozzle center is equipped with through hole, hole protrudes the lower end surface of suction nozzle, it is formed curved surface from hole to periphery extension, sealing ring is arranged outside curved surface, sealing ring lower end surface does not exceed the lower end surface of hole, support platform is arranged in the circumference of curved surface, support platform is connected with sealing ring.This utility model is communicated by hole and with the shell injection port of electricity core, since hole protrudes the lower end surface of suction nozzle, when electrolyte backflow, escaped electrolyte can be along curved surface and backflow to hole, thus there is no electrolyte or trace electrolyte in the lower end surface of suction nozzle, avoid or reduce the pollution of electrolyte to the lower end surface of suction nozzle, to make that suction nozzle surface is none or reduced crystallization formation.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery formation technology, specifically a negative pressure formation nozzle for lithium-ion batteries. Background Technology

[0002] In the manufacturing process of lithium-ion batteries, after the cell undergoes a liquid injection and high-temperature settling process, it enters the formation process. The formation process is the first charging of the cell. During this process, the ester electrolyte reacts on the surface of the negative electrode to form a solid electrolyte interphase (SEI) film. The SEI film can prevent further reactions of the electrolyte, avoid damage caused by solvent molecules to the electrode materials, and improve the cycle performance and lifespan of the lithium-ion battery.

[0003] During the formation process, a certain negative pressure is used to promptly extract the gases generated by the reaction within the battery cell. This prevents gas retention, which can lead to excessive localized internal resistance on the electrode surface, affecting the formation and uniformity of the SEI film, and ultimately impacting battery performance and lifespan. The vacuum pump pipe or negative pressure cup is connected to the battery cell casing via a negative pressure nozzle, which acts as a seal. Under negative pressure, the electrolyte within the cell, along with the gases, passes through the negative pressure nozzle into the buffer cup. Once atmospheric pressure is restored, the electrolyte flows back into the battery cell through the negative pressure nozzle. After the formation process, some electrolyte remains on the inner surface of the negative pressure nozzle orifice and at the contact seal between the nozzle and the casing. Prolonged exposure to high temperatures causes solvent evaporation and lithium salt crystallization, severely affecting airtightness. Frequent disassembly and cleaning of the negative pressure nozzle also weakens its strength and surface, leading to nozzle failure. A well-designed negative pressure nozzle structure can reduce lithium salt crystallization, decrease the frequency of disassembly and cleaning, and lower the manufacturing cost of lithium-ion batteries.

[0004] Chinese patent document CN219779138U discloses a suction nozzle structure, a formation apparatus, and battery production equipment. By setting the angle between the inner walls of the first and second channel sections of the suction channel to greater than 180°, droplets accumulate and naturally drip during electrolyte reflux, reducing the probability of electrolyte flowing along the inner wall of the first channel section to the contact surface between the suction nozzle structure and the battery cell casing. This reduces the probability of electrolyte contamination of the suction nozzle structure and minimizes electrolyte loss. However, in practical applications, to ensure effective electrolyte reflux, the transition from negative pressure to normal pressure (vacuum breaking) must be completed in a very short time. Because the lower end of the suction nozzle is concave upwards, the instantaneous reflux of electrolyte fills the space between the suction nozzle and the battery cell casing, resulting in poor actual performance of this suction nozzle structure.

[0005] Chinese patent document CN220290873U discloses a suction cup structure for a negative pressure cup. A protrusion on the inner wall of the lower end of the suction cup enhances its strength, preventing cracking and damage, and ensuring good airtightness between the suction cup and the battery filling port. However, in actual use, because the lower end of the suction cup is concave upwards, the electrolyte flows back instantly, filling the space between the suction cup and the battery cell casing. This results in some electrolyte failing to flow back to the battery cell, leading to electrolyte loss. Furthermore, the electrolyte remaining on the inner wall of the suction cup, after the battery cell is removed, flows along the inner wall to the lower edge of the suction cup under gravity. Under prolonged high temperatures, the solvent in the electrolyte remaining at the edge evaporates and solute crystals, affecting the suction cup's sealing performance and increasing the cost of cleaning or replacing the suction cup. Utility Model Content

[0006] The technical problem to be solved by this invention is how to reduce the crystallization of lithium-ion battery-formed negative pressure nozzles.

[0007] This utility model solves the above-mentioned technical problems through the following technical means:

[0008] This utility model provides a negative pressure formation nozzle for lithium-ion batteries. The nozzle has a through-hole in the center, which protrudes from the lower end face of the nozzle and extends outward to form a curved surface. A sealing ring is provided on the outer side of the curved surface, and the lower end face of the sealing ring does not exceed the lower end face of the through-hole. A support platform is arranged around the circumference of the curved surface, and the support platform is connected to the sealing ring.

[0009] Beneficial effects: This utility model connects to the electrolyte injection port of the battery cell shell through a channel. Since the channel protrudes from the lower end face of the nozzle, when the electrolyte flows back, the escaped electrolyte will flow back along the curved surface towards the channel. Therefore, there is no electrolyte or only a small amount of electrolyte on the lower end face of the nozzle, which avoids or reduces the contamination of the lower end face of the nozzle by the electrolyte, thereby making the formation of crystals on the nozzle surface less or non-existent.

[0010] To prevent misalignment between the channel and the electrolyte inlet of the battery cell casing during actual use, which could lead to a failure to seal or poor sealing, this invention features a sealing ring on the outer side of the curved surface. The sealing ring contacts the battery cell casing during use, ensuring a seal under pressure. Furthermore, this invention includes a support platform arranged circumferentially on the curved surface. During use, under pressure, the support platform contacts the battery cell casing, ensuring vertical connection between the channel and the electrolyte inlet, preventing the suction nozzle from tilting and causing a failure to seal or poor sealing. Simultaneously, the support platform reinforces the sealing ring, preventing deformation or cracking after repeated use.

[0011] Preferably, a reinforcing ring is provided around the nozzle.

[0012] Beneficial effects: The suction nozzle of this utility model is equipped with a reinforcing ring to enhance the axial and radial strength of the suction nozzle and to facilitate gripping.

[0013] Preferably, the channel includes a first air hole and a second air hole, the first air hole communicating with the second air hole, and the second air hole protruding from the lower end face of the suction nozzle.

[0014] Preferably, the inner diameter of the first vent is larger than the inner diameter of the second vent, and the inner diameter of the second vent is 3-10 mm.

[0015] Beneficial effects: The lithium-ion battery negative pressure formation nozzle of this utility model is sleeved on the metal tube. The step formed by the difference in inner diameter between the first air hole and the second air hole is used to fix and limit the position of the nozzle. At the same time, the step and the metal tube wall form a sealing effect under radial compression.

[0016] Preferably, the angle between the curved surface and the horizontal plane is 10-45°.

[0017] Preferably, the bottom surface of the sealing ring is a plane or a curved surface.

[0018] Preferably, one end of the support platform is connected to the sealing ring, and the height of the end of the platform is not higher than the height of the sealing ring.

[0019] Preferably, the number of support platforms is 4-12, and the distance between them and the second air hole is 2-10mm.

[0020] Preferably, the reinforcing ring has multiple layers, with a vertical height of 5-20mm and a thickness of 2-10mm.

[0021] Preferably, the height difference between the lower end face of the sealing ring and the lower end face of the second air hole is 0-2mm. Attached Figure Description

[0022] Figure 1 This is a three-dimensional schematic diagram of a lithium-ion battery negative pressure formation nozzle in Example 1;

[0023] Figure 2 This is a schematic cross-sectional view of a lithium-ion battery negative pressure formation nozzle in Example 1;

[0024] Figure 3 This is a three-dimensional schematic diagram of a lithium-ion battery negative pressure formation nozzle in Example 2;

[0025] Figure 4 This is a schematic cross-sectional view of a lithium-ion battery negative pressure formation nozzle in Example 2. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should be noted that unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] Example 1

[0029] according to Figure 1-3As shown, this embodiment provides a negative pressure formation nozzle 1 for a lithium-ion battery. The nozzle 1 has a central through-hole that protrudes from its lower end face and connects to the electrolyte inlet on the battery cell casing. A curved surface 13 extends outwards from the through-hole, forming a 20° angle with the horizontal plane. When the electrolyte flows back, the escaping electrolyte flows back along the curved surface towards the through-hole. Therefore, the lower end face of the nozzle 1 is free of electrolyte or contains only trace amounts of electrolyte, thus avoiding or reducing electrolyte contamination of the lower end face and minimizing or preventing crystal formation on the nozzle's lower end face. To prevent the through-hole from contacting the battery cell casing... Misalignment of the liquid injection port on the casing leads to failure to seal or poor sealing during liquid injection. A sealing ring 11 is provided on the outer side of the curved surface 13, with the lower end face of the sealing ring 11 not exceeding the lower end face of the channel, ensuring sealing under pressure. A support platform 12 is arranged around the circumference of the curved surface 13, which connects to the sealing ring 11 and contacts the battery cell casing, ensuring vertical communication between the channel and the liquid injection port on the battery cell casing, preventing the suction nozzle 1 from tilting and causing failure to seal or poor sealing. At the same time, the support platform 12 strengthens the sealing ring 11, preventing deformation or cracking of the sealing ring 11 after repeated use.

[0030] The nozzle 1 is made of rubber, which is either EPDM rubber or fluorinated silicone rubber. In this embodiment, EPDM rubber is used to make the nozzle 1 through injection molding.

[0031] The nozzle 1 is provided with a reinforcing ring 10 on its periphery. The reinforcing ring 10 is provided in one layer. The vertical height of the reinforcing ring 1 is 7mm and the thickness is 5mm. The upper end face of the reinforcing ring 10 is 9mm away from the upper end face of the nozzle 1.

[0032] The channel includes a first air hole 2 and a second air hole 3. The first air hole 2 communicates with the second air hole 3. The second air hole 3 protrudes from the lower end face of the suction nozzle 1 and is connected to the liquid injection port of the battery cell shell. The inner diameter of the first air hole 2 is larger than the inner diameter of the second air hole. The inner diameter of the first air hole 2 is 7.5 mm, and the inner diameter of the second air hole 3 is 4 mm.

[0033] The lower end face of the sealing ring 11 is curved, the radius of the curved surface is 2mm, the thickness of the sealing ring 11 is 1mm, and the lower end face of the sealing ring 11 is 0.4mm lower than the lower end face of the second vent 3.

[0034] There are 6 support platforms 12. The support platforms 12 are evenly distributed around the circumference of the sealing ring 11. The cross-section of the support platform 12 is rectangular, with a length and width of 2mm. The cross-section of the support platform 12 is trapezoidal. The lower base of the trapezoid is where the support platform 12 connects to the sealing ring 11. The upper base of the trapezoid is the end of the support platform 12 away from the sealing ring 11. The upper base is smaller than the lower base. The support platform 12 is 3mm away from the second air hole 3.

[0035] Example 2

[0036] This embodiment provides a negative pressure formation nozzle for lithium-ion batteries. The difference between this embodiment and embodiment 1 is that this embodiment uses fluorinated silicone rubber to form the nozzle 1 through injection molding.

[0037] The angle between the curved surface 13 and the horizontal plane is 15°.

[0038] The inner diameter of the first vent 2 is 8mm, and the inner diameter of the second vent 3 is 6mm.

[0039] The reinforcing ring 10 has a vertical height of 10mm and a width of 4mm. The upper end face of the reinforcing ring 10 is 8mm away from the upper end face of the nozzle 1.

[0040] The sealing ring 11 has a thickness of 2 mm, and the lower end face of the sealing ring 11 is 0.1 mm lower than the lower end face of the second vent 3.

[0041] The cross-section of the support platform 12 is a rounded rectangle with a width of 3mm and a length of 3mm for the longest side. The support platform 12 is 1.1mm away from the second air hole 3.

[0042] This utility model proposes a negative pressure formation nozzle for lithium-ion batteries. The second air hole 3 protrudes from the lower end face of the nozzle 1, and the lower end of the nozzle 1 is inserted into the electrolyte injection port of the battery cell shell to prevent the electrolyte from flowing back and contaminating the lower end face of the nozzle 1 during the formation process, thereby reducing the formation of crystals on the surface of the nozzle 1. At the same time, a sealing ring 11 and a support platform 12 are provided to ensure the sealing effect of the nozzle 1 and improve its service life.

[0043] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A negative pressure formation nozzle for lithium-ion batteries, characterized in that, The nozzle (1) has a through hole in the center. The hole protrudes from the lower end face of the nozzle (1) and extends outward to form a curved surface (13). A sealing ring (11) is provided on the outside of the curved surface (13). The lower end face of the sealing ring (11) does not exceed the lower end face of the hole. A support platform (12) is arranged along the circumference of the curved surface (13). The support platform (12) is connected to the sealing ring (11).

2. The lithium-ion battery negative pressure formation nozzle according to claim 1, characterized in that, A reinforcing ring (10) is provided around the nozzle (1).

3. The lithium-ion battery negative pressure formation nozzle according to claim 1, characterized in that, The channel includes a first air hole (2) and a second air hole (3), the first air hole (2) and the second air hole (3) are connected, and the second air hole (3) protrudes from the lower end face of the suction nozzle (1).

4. The lithium-ion battery negative pressure formation nozzle according to claim 3, characterized in that, The inner diameter of the first vent (2) is larger than the inner diameter of the second vent (3), and the inner diameter of the second vent (3) is 3-10 mm.

5. The lithium-ion battery negative pressure formation nozzle according to claim 1, characterized in that, The angle between the curved surface (13) and the horizontal plane is 10-45°.

6. The lithium-ion battery negative pressure formation nozzle according to claim 1, characterized in that, The lower end face of the sealing ring (11) is either a plane or a curved surface.

7. The lithium-ion battery negative pressure formation nozzle according to claim 1, characterized in that, One end of the support platform (12) is connected to the sealing ring (11), and the height of its end is not higher than the height of the sealing ring (11).

8. The lithium-ion battery negative pressure formation nozzle according to claim 3, characterized in that, The number of support platforms (12) is 4-12, and the distance between them and the second air hole (3) is 2-10mm.

9. The lithium-ion battery negative pressure formation nozzle according to claim 2, characterized in that, The reinforcing ring (10) has multiple layers, with a vertical height of 5-20mm and a thickness of 2-10mm.

10. The lithium-ion battery negative pressure formation nozzle according to claim 3, characterized in that, The height difference between the lower end face of the sealing ring (11) and the lower end face of the second air hole (3) is 0-2mm.

Images