A sealing leak-proof structure of a lithium battery liquid injection port

Abstract

The utility model discloses a kind of sealing leakproof structure of lithium battery liquid injection port, belong to lithium battery technical field.The structure includes liquid injection mechanism and the sealing mechanism matched with it;Liquid injection mechanism is equipped with conical liquid injection pipe and outer thread;Sealing mechanism is equipped with the conical sealing head matched with conical pipe, the connecting ring with internal thread, second sealing ring and welding ring.Tighten connecting ring, make conical sealing head and conical pipe adhere, and compress second sealing ring and adhere battery body, finally welding ring and battery body are welded and fixed.The utility model constructs fourfold sealing protection by taper face, elasticity, thread and welding, solve the single sealing level of prior art, long-term reliability is poor, the problem of easy leakage, with excellent sealing performance, structure connection is stable, can comprehensively guarantee the remarkable advantages of battery use safety.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a sealing and leak-proof structure for the filling port of a lithium battery. Background Technology

[0002] During the production of lithium batteries, electrolyte needs to be injected into the battery through a pre-designed injection port. After injection, the injection port must be strictly and permanently sealed to prevent leakage of the internal electrolyte. Electrolyte leakage not only affects the battery's capacity and cycle life but can also cause serious safety accidents such as short circuits and fires.

[0003] Currently, the industry mainly uses two methods to seal the filling port: using elastic plugs or laser welding with metal covers. The sealing performance of the elastic plug method relies primarily on the interference fit and elastic deformation of the plug itself. During long-term battery use, especially under frequent temperature changes and continuous vibration, the elastic material is prone to aging and creep, leading to a decrease in sealing stress and the creation of tiny leakage channels, resulting in insufficient long-term reliability.

[0004] To improve the permanence of the seal, laser welding of metal caps or sealing studs is more common. While this method can create a strong metal connection, the success of the seal depends entirely on the quality of a single weld. During the welding process, any minor process defect, such as incomplete welds, discontinuous welds, or the presence of porosity, can directly create a leak point. This structure, relying on a single sealing interface, lacks redundant protection mechanisms. Once the primary seal fails, there is no second line of defense, posing a risk of single-point failure.

[0005] Therefore, this utility model proposes a sealing and leak-proof structure for the lithium battery filling port to overcome the shortcomings of the prior art. Utility Model Content

[0006] To overcome the above deficiencies, this utility model provides a sealing and leak-proof structure for the electrolyte filling port of a lithium battery, aiming to improve the problems of the existing lithium battery filling port, such as a single sealing structure, lack of multiple protection, easy leakage of electrolyte due to single point failure under long-term use or complex working conditions, and low reliability.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a sealing and leak-proof structure for a lithium battery filling port, comprising: a battery body, a filling mechanism disposed on the battery body, and a sealing mechanism for sealing the filling mechanism.

[0008] The injection mechanism includes a tapered injection tube and an external thread on the outside of the tapered injection tube; the sealing mechanism includes a tapered sealing head that mates with the tapered injection tube, a connecting ring with an internal thread, a second sealing ring, and a welding ring.

[0009] The connecting ring of the sealing mechanism is combined with the external thread of the liquid injection mechanism by means of a threaded connection. When the connecting ring is tightened, it can compress the second sealing ring so that it fits tightly against the outer wall of the battery body. At the same time, the welding ring is used to weld and fix the sealing mechanism to the battery body.

[0010] Preferably, the conical injection tube of the injection mechanism is provided with a sealing groove; the sealing mechanism further includes a first sealing ring, which is disposed on the conical sealing head and is engaged in the sealing groove when the conical sealing head and the conical injection tube are engaged to form an enhanced internal seal.

[0011] Preferably, the first sealing ring is disposed around the outer periphery of the conical sealing head and is located between the conical surface of the conical sealing head and the connecting ring.

[0012] Preferably, the second sealing ring is disposed at the end of the connecting ring facing the battery body to achieve the best compression sealing effect.

[0013] Preferably, the welding ring is disposed around the outer periphery of the connecting ring to facilitate welding operations.

[0014] Preferably, the outer conical surface of the conical sealing head and the inner conical surface of the conical injection tube are matched in shape and size to ensure a tight contact seal between them.

[0015] Preferably, both the first sealing ring and the second sealing ring are made of elastic material to provide reliable elastic sealing performance.

[0016] Preferably, the sealing and leak-proof structure of the lithium battery filling port also includes a pull ring, which is integrally formed or fixedly connected to the battery body for easy handling.

[0017] This utility model has the following beneficial effects: 1. In this utility model, by setting a conical sealing head to fit the conical surface of the conical injection tube, and combining the first sealing ring that is inserted into the sealing groove and the second sealing ring that is compressed by tightening the thread, a multi-layer sealing structure from the inside to the outside is formed. This solves the problem of single sealing layer of the injection port in the prior art, which is prone to electrolyte leakage due to single-point failure. It achieves the technical effect of high sealing reliability and significant leakage prevention effect.

[0018] 2. In this utility model, by setting a welding ring to weld the entire sealing mechanism to the battery body as one unit, the problem of non-permanent connection sealing structure in the prior art will loosen under long-term vibration, impact or temperature change environment, thus leading to sealing failure is solved. The technical effect of stable structural connection, strong impact and vibration resistance, and long-lasting and reliable sealing effect is achieved. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of a sealing and leak-proof structure for a lithium battery filling port proposed in this utility model. Figure 2 An exploded view of a sealing and leak-proof structure for a lithium battery filling port proposed in this utility model; Figure 3 This is a schematic diagram of the liquid injection mechanism of a sealing and leak-proof structure for a lithium battery liquid injection port proposed in this utility model; Figure 4 This is an exploded view of the sealing mechanism of a sealing and leak-proof structure for a lithium battery filling port proposed in this utility model.

[0020] Legend: 1. Battery body; 2. Pull ring; 3. Liquid injection mechanism; 301. Conical liquid injection tube; 302. External thread; 303. Sealing groove; 4. Sealing mechanism; 401. Conical sealing head; 402. First sealing ring; 403. Connecting ring; 404. Internal thread; 405. Second sealing ring; 406. Welding ring. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Reference Figure 1 - Figure 4 The present invention provides an embodiment of a sealing and leak-proof structure for a lithium battery filling port, which aims to solve the problem that the existing lithium battery filling port has a single sealing layer and insufficient long-term reliability, which easily leads to electrolyte leakage.

[0023] The sealing and leak-proof structure of the lithium battery filling port includes a battery body 1, a filling mechanism 3 disposed on the battery body 1, and a sealing mechanism 4 for sealing the filling mechanism 3. The battery body 1 is used to contain electrolyte and serves as the mounting base for the entire sealing and leak-proof structure. The filling mechanism 3 and the sealing mechanism 4 cooperate with each other to achieve the sealing of the filling port. The structure also includes a pull ring 2, which is integrally formed or fixedly connected to the battery body 1. The electrolyte injection mechanism 3 includes a tapered injection tube 301, the inner wall of which forms an inner conical surface, and the outer wall of which is provided with an external thread 302 and a sealing groove 303. The tapered injection tube 301 is used to guide the electrolyte into the battery body 1.

[0024] The sealing mechanism 4 includes a conical sealing head 401, whose outer conical surface matches the inner conical surface of the conical injection tube 301 in shape and size, so that it can be tightly inserted into the conical injection tube 301. The sealing mechanism 4 also includes a connecting ring 403, on the inner wall of which is provided an internal thread 404 that mates with the external thread 302.

[0025] During the assembly and sealing process, the conical sealing head 401 is first inserted into the conical injection tube 301 to form a preliminary fit and seal. Then, by rotating the connecting ring 403, its internal thread 404 forms a threaded connection with the external thread 302 of the injection mechanism 3. During the tightening process, the second sealing ring 405, located at the end of the connecting ring 403 facing the battery body 1, is compressed and tightly fits against the outer wall of the battery body 1, forming a second seal. Finally, the welding ring 406, which is located around the outer periphery of the connecting ring 403, forms a permanent fixed connection with the battery body 1 through a welding process, thereby achieving the final seal. This multi-seal structure, consisting of conical surface fitting, threaded compression and final welding, ensures the long-term and reliable leak-proof performance of the injection port.

[0026] The specific process for welding the welding ring 406 to the battery body 1 can be achieved by various conventional methods such as laser welding, which are known in the art and will not be described in detail here.

[0027] In a preferred embodiment, to further enhance the sealing effect between the conical sealing head 401 and the conical injection tube 301, the conical injection tube 301 of the injection mechanism 3 is provided with a sealing groove 303. The sealing mechanism 4 also includes a first sealing ring 402, which is arranged around the outer periphery of the conical sealing head 401 and located between the conical surface of the conical sealing head 401 and the connecting ring 403. When the conical sealing head 401 and the conical injection tube 301 are engaged, the first sealing ring 402 can be inserted into the sealing groove 303 to form an additional enhanced seal. To ensure the reliability of the seal and the elastic deformation capability, both the first sealing ring 402 and the second sealing ring 405 are made of elastic material. To optimize the force and sealing position of the second sealing ring 405, the second sealing ring 405 is specifically arranged around the end of the connecting ring 403 facing the battery body 1, so as to ensure that when the connecting ring 403 is tightened, the pressure can be directly and evenly applied to it. To facilitate welding operations and form a robust welded structure, the welding ring 406 is specifically arranged around the outer periphery of the connecting ring 403; to facilitate the operator to pick up and move the battery body 1, the structure also includes a pull ring 2, which is integrally formed or fixedly connected to the battery body 1.

[0028] Working principle: In use, electrolyte is first injected into the battery body 1 through the conical injection tube 301 of the injection mechanism 3. After injection, a sealing operation is performed. The conical sealing head 401 of the sealing mechanism 4 is inserted into the conical injection tube 301. Since the outer conical surface of the conical sealing head 401 matches the inner conical surface of the conical injection tube 301 in shape and size, the two fit together to form a preliminary seal. As the sealing mechanism 4 is pushed in, its first sealing ring 402 is engaged in the sealing groove 303 of the conical injection tube 301, achieving the first layer of enhanced sealing. Then, the connecting ring 403 is rotated, and its internal thread 404 engages with the external thread 302 of the injection mechanism 3. The conical sealing head 401 and the first sealing ring 402 are tightened together, which makes the fit between them more tighter and compresses the second sealing ring 405, making it fit tightly against the outer wall of the battery body 1, forming a second external seal. Finally, the welding ring 406 is fixedly connected to the battery body 1 by welding, forming an integrated permanent sealing structure. Through the multi-level synergistic effect of the conical surface fitting, double sealing ring compression, thread tightening and final welding, this utility model effectively solves the problem of electrolyte leakage caused by the single sealing structure in the prior art, and significantly improves the safety and long-term reliability of the battery.

Claims

1. A sealing and leak-proof structure for the electrolyte filling port of a lithium battery, comprising: The battery body (1), the liquid injection mechanism (3) disposed on the battery body (1), and the sealing mechanism (4) for sealing the liquid injection mechanism (3) are characterized in that: The injection mechanism (3) includes a tapered injection tube (301) and an external thread (302) located outside the tapered injection tube (301). The sealing mechanism (4) includes a conical sealing head (401) that mates with the conical injection tube (301), and also includes a connecting ring (403) with an internal thread (404). The sealing mechanism (4) further includes a second sealing ring (405) and a welding ring (406). When the connecting ring (403) is tightened with the external thread (302) through its internal thread (404), it can compress the second sealing ring (405) so that it fits against the outer wall of the battery body (1). The welding ring (406) is used to weld and fix the sealing mechanism (4) to the battery body (1).

2. The sealing and leak-proof structure for the lithium battery filling port according to claim 1, characterized in that, The conical injection tube (301) of the injection mechanism (3) is provided with a sealing groove (303). The sealing mechanism (4) further includes a first sealing ring (402), which is disposed on the conical sealing head (401) and is inserted into the sealing groove (303) when the conical sealing head (401) and the conical injection tube (301) are engaged.

3. The sealing and leak-proof structure for the lithium battery filling port according to claim 2, characterized in that, The first sealing ring (402) is disposed around the outer periphery of the conical sealing head (401) and is located between the conical surface of the conical sealing head (401) and the connecting ring (403).

4. The sealing and leak-proof structure for the lithium battery filling port according to claim 1 or 2, characterized in that, The second sealing ring (405) is disposed on the end of the connecting ring (403) facing the battery body (1).

5. The sealing and leak-proof structure for the lithium battery filling port according to claim 1 or 2, characterized in that, The welding ring (406) is disposed around the outer periphery of the connecting ring (403).

6. The sealing and leak-proof structure for the lithium battery filling port according to claim 1, characterized in that, The outer conical surface of the conical sealing head (401) matches the inner conical surface of the conical injection tube (301) in shape and size.

7. The sealing and leak-proof structure for the lithium battery filling port according to claim 2, characterized in that, Both the first sealing ring (402) and the second sealing ring (405) are made of elastic material.

8. The sealing and leak-proof structure for the lithium battery filling port according to claim 1, characterized in that, The structure also includes a pull ring (2), which is integrally formed or fixedly connected to the battery body (1).

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