Negative pressure device for reducing liquid loss during lithium battery formation

Abstract

The utility model discloses a negative pressure device that reduces the liquid loss of lithium battery formation, comprising: a cup body for temporarily storing the extracted lithium battery electrolyte; a suction nozzle connector detachably connected to the bottom of the cup body; a liquid loss prevention diaphragm fixed to the inner side of the cup body for isolating liquid; and a liquid inlet pipe connected to the lower side of the suction nozzle connector for aligning with the liquid injection port of the lithium battery. Advantage: the negative pressure cup designed in the application is internally provided with a liquid loss prevention gasket, which can effectively prevent the electrolyte from being lost during the formation process.

Description

Technical Field

[0001] This utility model relates to the field of new energy batteries, and in particular to a negative pressure device for reducing the amount of liquid loss during the formation of lithium batteries. Background Technology

[0002] The formation process of lithium-ion batteries is a crucial step in their manufacturing. During the formation and charging process, chemical reactions occur inside the cell, generating gases that form a solid electrolyte interphase (SEI) film on the negative electrode surface. If these gases are not removed in time, they will affect the performance of the lithium-ion battery. Therefore, a high negative pressure environment must be maintained during charging. To prevent electrolyte loss, a negative pressure cup is used to temporarily collect the electrolyte. However, even with this, some electrolyte will still be lost during the formation process, and this lost electrolyte cannot flow back into the cell.

[0003] In addition, lithium batteries generate heat during charging, which may cause the electrolyte to crystallize and become blocked in the negative pressure formation system, requiring the negative pressure cup to be replaced regularly, thus increasing production costs.

[0004] Some existing technologies offer solutions. For example, patent CN221668899U discloses an integrated negative pressure cup, which effectively reduces electrolyte loss during the formation process. However, partially vaporized electrolyte may still be drawn away by the high negative pressure, and the cleaning and maintenance of this device are relatively complex, requiring regular replacement.

[0005] In addition, patent CN120319899A proposes an integrated system comprising an independent electrolyte collection device, a negative pressure generating device, and a weighing system. The key feature of this technology is that each battery cell is equipped with an independent electrolyte collection device, which actively draws the electrolyte from the cavity into a collection container using negative pressure and quantifies the amount of electrolyte loss in real time, forming a closed-loop control of "collection-measurement-replenishment". While this solution solves the traditional problem of disordered electrolyte discharge and provides data support for the replenishment process, the use of high-precision weighing or level sensors significantly increases costs. Utility Model Content

[0006] Purpose of the utility model: The purpose of this utility model is to solve the problems in the prior art and provide a negative pressure device to reduce the amount of liquid loss during lithium battery formation.

[0007] Technical solution: A negative pressure device for reducing liquid loss during lithium battery formation is proposed, comprising: The cup body is used to temporarily store the lithium battery electrolyte that has been drawn in. The spout connector is detachably attached to the bottom of the cup body. A liquid-prevention diaphragm is fixed to the inside of the cup body to isolate the liquid. The liquid inlet tube is connected to the lower side of the suction nozzle connector and is used to align with the lithium battery liquid filling port; The suction nozzle is used to connect to the negative pressure device so that the liquid inlet tube generates suction to draw the electrolyte into the cup.

[0008] Preferably, the anti-liquid loss diaphragm is one of the following: waterproof, oil-proof, breathable membrane, semi-permeable membrane, or microporous structure material.

[0009] Preferably, the diameter of the inlet pipe is smaller than the diameter of the cup body.

[0010] Preferably, the nozzle connector is fixed to the bottom of the cup body by threads or snaps.

[0011] Preferably, the bottom diameter of the suction nozzle matches the size of the lithium battery filling hole, so that the suction nozzle can be inserted into the lithium battery filling hole in a close fit.

[0012] Preferably, the waterproof, oil-proof, and breathable membrane is made of expanded polytetrafluoroethylene (ePTFE).

[0013] Preferably, the semipermeable membrane has a hydrophobic fiber structure.

[0014] Preferably, the micropore size of the microporous structure material is larger than that of a gas molecule and smaller than that of a droplet.

[0015] Preferably, the inner wall of the cup body is provided with a limiting block for fixing the anti-liquid loss diaphragm.

[0016] Preferably, the number of limiting blocks is greater than or equal to four, and they are at the same height. Beneficial effects

[0017] The negative pressure cup designed in this invention features an internal anti-leakage gasket, which effectively prevents electrolyte loss during the formation process. The anti-leakage gasket is made of oil-resistant and wear-resistant rubber or plastic material, combined with a waterproof, oil-proof, and breathable membrane, a semi-permeable membrane, or a microporous structure material. These materials not only prevent electrolyte loss but also ensure smooth gas discharge, thereby improving the overall performance of the negative pressure cup.

[0018] Thanks to the presence of anti-loss gaskets, the electrolyte can be retained inside the cell or in the negative pressure cup under negative pressure, thus preventing clogging of the negative pressure device during the formation process. At the same time, the probability of clogging of the negative pressure device is greatly reduced, minimizing maintenance work required due to blockages.

[0019] The negative pressure cup features a detachable structure, with the base connected to the cup body via threads and snap-fit, facilitating disassembly and cleaning. The anti-liquid-loss gasket is also removable, allowing for regular cleaning or replacement, thus reducing maintenance costs and complexity.

[0020] By optimizing the design, the use of complex high-precision weighing or level sensors is avoided, reducing system costs while retaining the core functions of a traditional negative pressure system. This allows the invention to significantly reduce production costs while maintaining high performance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] Figure 2 This is a schematic diagram of the anti-liquid loss diaphragm structure of this utility model.

[0023] Figure label: 1. Inlet pipe; 2. Cup body; 3. Limiting block; 4. Suction nozzle connector; 5. Anti-liquid loss diaphragm; 6. Suction nozzle. Detailed Implementation

[0024] To make the technical solution of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0025] To make the technical solution of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects.

[0027] In response to the problems existing in the current technology, combined with Figure 1-2 A negative pressure device for reducing liquid loss during lithium battery formation, comprising: Cup 2 is used to temporarily store the absorbed lithium battery electrolyte; The nozzle connector 4 is detachably connected to the bottom of the cup body 2; The anti-liquid-loss diaphragm 5 is fixed to the inside of the cup body 2 to isolate liquid; The liquid inlet pipe 1 is connected to the lower side of the suction nozzle connector 4 and is used to align with the lithium battery liquid filling port. The suction nozzle 6 is used to connect to the negative pressure device so that the liquid inlet pipe 1 generates suction to draw the electrolyte into the cup body 2.

[0028] Specifically, the liquid inlet pipe 1 is connected to the existing negative pressure device to generate gas suction, which facilitates the absorption of electrolyte through the suction nozzle 6 and makes it easier to absorb the electrolyte inside the cup body 2. At the same time, the liquid loss diaphragm prevents liquid from passing through the anti-liquid loss diaphragm 5. Only the negative pressure gas generated by the negative pressure device passes through the anti-liquid loss diaphragm 5, thus preventing electrolyte loss and blockage inside the negative pressure device. After the suction is completed, the nozzle and electrolyte are separated, and the negative pressure device is turned off to facilitate the discharge of electrolyte from the cup 2.

[0029] In some specific embodiments, the anti-liquid loss diaphragm 5 is one of a waterproof, oil-proof, and breathable membrane, a semi-permeable membrane, or a microporous material. These materials prevent the passage of liquids such as moisture and electrolyte, while allowing gas to pass through smoothly. They can effectively block electrolyte while simultaneously removing gas from inside the battery cell.

[0030] In some specific embodiments, the diameter of the inlet pipe 1 is smaller than the diameter of the cup body 2, reducing the possibility of electrolyte clogging the negative pressure system.

[0031] In some specific embodiments, the suction nozzle connector 4 is fixed to the bottom of the cup body 2 by threads or snaps, which facilitates disassembly for maintenance of the inside of the cup body 2 and for cleaning.

[0032] In some specific embodiments, the bottom diameter of the suction nozzle 6 matches the size of the lithium battery injection hole so that the suction nozzle 6 can be inserted into the lithium battery injection hole in a close fit. The precise docking of the suction nozzle and the injection hole is the key to achieving vacuum pressure maintenance and helps maintain the required negative pressure environment.

[0033] In some specific embodiments, the waterproof, oil-proof, and breathable membrane is made of expanded polytetrafluoroethylene (ePTFE).

[0034] In some specific embodiments, the semipermeable membrane is a hydrophobic fiber structure.

[0035] In some specific embodiments, the micropore size of the microporous structure material is larger than that of a gas molecule and smaller than that of a droplet.

[0036] The above materials prevent liquids such as water and electrolyte from passing through, while allowing gas to pass through smoothly. This can effectively block electrolyte while removing gas generated inside the battery cell.

[0037] In some specific embodiments, the inner wall of the cup body 2 is provided with a limiting block 3 for fixing the anti-liquid loss diaphragm 5.

[0038] In some specific embodiments, the number of limiting blocks 3 is greater than or equal to four, and they are at the same height. The limiting blocks clamp and fix the anti-liquid loss diaphragm on both sides.

[0039] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A negative pressure device for reducing liquid loss during lithium battery formation, characterized in that, include: The cup body (2) is used to temporarily store the absorbed lithium battery electrolyte; The nozzle connector (4) is detachably connected to the bottom of the cup body (2); A liquid-prevention diaphragm (5) is fixed to the inside of the cup body (2) to allow only gas to pass through while isolating the liquid. The liquid inlet pipe (1) is connected to the lower side of the suction nozzle connector (4) and is used to align with the lithium battery liquid inlet. The nozzle (6) is used to connect with the negative pressure device so that the liquid inlet pipe (1) generates suction to draw the electrolyte into the cup body (2).

2. The negative pressure device for reducing liquid loss during lithium battery formation according to claim 1, characterized in that, The anti-liquid loss diaphragm (5) is one of the following: waterproof, oil-proof and breathable membrane, semi-permeable membrane, and microporous structure material.

3. The negative pressure device for reducing liquid loss during lithium battery formation according to claim 1, characterized in that, The diameter of the inlet pipe (1) is smaller than the diameter of the cup body (2).

4. The negative pressure device for reducing liquid loss during lithium battery formation according to claim 1, characterized in that, The nozzle connector (4) is fixed to the bottom of the cup body (2) by threads or snaps.

5. The negative pressure device for reducing liquid loss during lithium battery formation according to claim 1, characterized in that, The bottom diameter of the suction nozzle (6) matches the size of the lithium battery injection hole so that the suction nozzle (6) can be inserted into the lithium battery injection hole in a close fit.

6. The negative pressure device for reducing liquid loss during lithium battery formation according to claim 2, characterized in that, The waterproof, oil-proof, and breathable membrane is made of expanded polytetrafluoroethylene (ePTFE).

7. The negative pressure device for reducing liquid loss during lithium battery formation according to claim 2, characterized in that, The semi-permeable membrane has a hydrophobic fiber structure.

8. The negative pressure device for reducing liquid loss during lithium battery formation according to claim 2, characterized in that, The micropore size of the microporous structure material is larger than that of a gas molecule but smaller than that of a droplet.

9. A negative pressure device for reducing liquid loss during lithium battery formation according to claim 1, characterized in that, The inner wall of the cup body (2) is provided with a limiting block (3) for fixing the anti-liquid loss diaphragm (5).

10. A negative pressure device for reducing liquid loss during lithium battery formation according to claim 9, characterized in that, The number of the limiting blocks (3) is greater than or equal to four, and they are at the same height.

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