Small cylindrical lithium ion battery shell capable of detecting leakage and exhausting

Abstract

The utility model relates to the technical field of battery shells, in particular to a small cylindrical lithium ion battery shell capable of detecting leakage and exhausting, which comprises a battery shell body, and a liquid injection and exhaust hole is formed in the middle of the lower end of the battery shell body. The liquid injection and exhaust hole can be used for injecting liquid into the battery shell body and exhausting gas in the battery shell body, guide springs are fixedly connected to the two sides of the middle of the inner bottom surface of the battery shell body, and a push plate is fixedly connected to the upper ends of the two guide springs; the outer wall of the push plate is tightly attached to the inner wall of the battery shell body, a piston rod is fixedly connected to the middle of the lower end face of the push plate, the lower end of the piston rod is slidably connected into the liquid injection exhaust hole, and a fixing ring is fixedly connected to the lower end of the middle of the inner wall of the liquid injection exhaust hole. Compared with the prior art, the problem that formation gas cannot be discharged after the small cylindrical lithium ion battery is sealed in the prior art is solved.

Description

Technical Field

[0001] This utility model relates to the field of battery casing technology, and in particular to a small cylindrical lithium-ion battery casing capable of detecting leaks and releasing gas. Background Technology

[0002] With the rapid development of global informatization, people's demand for battery performance in the field of small cylindrical lithium-ion batteries is also constantly increasing. From the initial 18650 to 21700, and now to the 26650 cylindrical lithium-ion battery, battery technology is developing steadily and rapidly. However, due to insufficient understanding of the battery cell in the initial design, there are obvious defects in the cell process design.

[0003] The current mainstream production process for small cylindrical lithium-ion batteries (18650, 21700, 26650, etc.) involves battery electrolyte injection → sealing → formation → capacity testing. This process has significant drawbacks: 1. Inability to detect leaks: After sealing, leak detection is impossible, leading to some micro-leaking cells going undetected and flowing into the next process or even into the hands of customers. 2. Risk of explosion-proof valve rupture: After sealing, the gas generated during battery formation remains trapped inside the cell's steel casing, increasing the internal pressure. This gas generation during subsequent cycles can easily cause the explosion-proof valve to rupture, affecting the battery's safe operation. 3. Risk of lithium plating and low capacity: The gas generated during formation cannot escape from the steel casing, affecting the physical contact between the separator and the electrodes, leading to bubble formation. This hinders lithium-ion transport and can result in lithium plating, significantly impacting the cell's capacity, rate capability, and cycle life.

[0004] Furthermore, we disclose a leak-detectable and venting small cylindrical lithium-ion battery casing to solve the problem that the gas formed after sealing small cylindrical lithium-ion batteries in the prior art cannot be released. Utility Model Content

[0005] In view of this, the purpose of this utility model is to propose a small cylindrical lithium-ion battery casing that can detect leaks and release gas, so as to solve the problem that the gas formed after the small cylindrical lithium-ion battery is sealed in the prior art cannot be released.

[0006] Based on the above objectives, this utility model provides a small cylindrical lithium-ion battery casing with leak detection and venting capability, comprising a battery casing body. A liquid injection and venting hole is provided at the lower center of the battery casing body. The liquid injection and venting hole can be used to inject liquid into the battery casing body and to vent gas from inside the battery casing body. Guide springs are fixedly connected to both sides of the inner bottom surface of the battery casing body. Push plates are fixedly connected to the upper ends of the two guide springs. The outer wall of the push plate is tightly fitted to the inner wall of the battery casing body. A piston rod is fixedly connected to the lower center of the push plate. The lower end of the piston rod is slidably connected to the liquid injection and venting hole. A fixing ring is fixedly connected to the lower center of the inner wall of the liquid injection and venting hole. Telescopic springs are fixedly connected to both sides of the lower end of the fixing ring. A sealing plate is fixedly connected to the end of the two telescopic springs away from the fixing ring. The end face of the sealing plate near the telescopic spring contacts the lower end face of the battery casing body. A sealing sleeve is threadedly connected to the middle of the sealing plate.

[0007] Preferably, each of the two guide springs has a guide rod inside, the lower end of the guide rod is fixedly connected to the battery casing body, and the upper end of the guide rod passes through the push plate and is fixedly connected to a limit plate.

[0008] Preferably, the guide rod is slidably connected to the push plate and a sealing structure is provided at the connection.

[0009] Preferably, the piston rod has a through hole in the middle, and the upper end of the through hole passes through the push plate.

[0010] Preferably, a mounting bracket is fixedly connected to the upper end of the inner wall of the through hole, a connecting spring is fixedly connected to the middle of the lower end face of the mounting bracket, a ball head is fixedly connected to the lower end of the connecting spring, a top plate is rotatably connected to the lower end of the ball head, the outer wall of the top plate is tightly fitted to the inner wall of the through hole, and rounded corners are provided at both the upper and lower ends of the outer wall of the top plate.

[0011] Preferably, a baffle is fixedly connected to the upper side of the middle part of the inner wall of the through hole, and a retaining ring is fixedly connected to the upper end of the inner wall of the through hole located on the top plate.

[0012] Preferably, a push rod is fixedly connected to both sides of the lower end of the piston rod, and the side of the push rod closest to the sealing plate is spherical.

[0013] The beneficial effects of this utility model are:

[0014] This small cylindrical lithium-ion battery features a liquid injection vent on its casing. Through this vent and a sophisticated internal mechanical design, the design automatically opens the vent when the internal pressure increases due to gas production from a chemical reaction. Specifically, the increased pressure pushes a push plate and piston rod upwards, lifting the sealing plate and allowing the gas to escape smoothly through the vent. This process effectively reduces internal pressure, preventing the explosion-proof valve from rupturing due to excessive pressure. It also improves the physical contact between the electrodes and the separator, reducing bubble formation and facilitating lithium-ion transport, thus preventing lithium plating and significantly enhancing the battery's cycle performance, rate performance, and capacity. Therefore, the venting mechanism greatly enhances battery safety and lifespan, providing a strong guarantee for stable battery operation.

[0015] The electrolyte filling and venting port on the small cylindrical lithium-ion battery casing allows for electrolyte filling inside the casing. When electrolyte needs to be added, the operator can easily add electrolyte to the battery through the filling and venting port. By gently turning the sealing sleeve with a wrench or other tools, it can be removed from the sealing plate, thus releasing the fixing effect of the sealing plate. Next, the electrolyte filling tube is accurately inserted into the through hole and contacts the top plate. Then, the top plate is deflected, thus completing the electrolyte filling process and adding the required electrolyte to the battery. After the electrolyte filling is completed, the top plate is reset by the retaining ring, ensuring that the gas inside the battery casing will not escape to the outside of the battery casing through the top plate. This ingenious design not only ensures the smooth progress of the electrolyte filling process but also effectively prevents the leakage of gas inside the battery, thereby maintaining the stability of the internal environment of the battery. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the internal three-dimensional structure of the present invention;

[0018] Figure 2 This is a partial three-dimensional structural diagram of the present invention;

[0019] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0020] Figure 4 This is a three-dimensional structural diagram of the piston rod of this utility model.

[0021] The diagram is marked as follows:

[0022] 1. Battery casing body; 2. Push plate; 3. Guide rod; 4. Guide spring; 5. Limiting plate; 6. Piston rod; 7. Through hole; 8. Mounting bracket; 9. Connecting spring; 10. Top plate; 11. Baffle; 12. Top rod; 13. Fixing ring; 14. Telescopic spring; 15. Sealing screw sleeve; 16. Sealing plate; 17. Fluid injection and venting hole; 18. Ball head; 19. Retaining ring. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments.

[0024] It should be noted that, unless otherwise defined, the technical or scientific terms used in this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] like Figures 1 to 4 As shown, a small cylindrical lithium-ion battery casing with leak detection and venting capability includes a battery casing body 1. A liquid injection and venting hole 17 is provided at the lower center of the battery casing body 1. The liquid injection and venting hole 17 can be used to inject liquid into the battery casing body 1 and to vent gas inside the battery casing body 1. Guide springs 4 are fixedly connected to both sides of the middle of the inner bottom surface of the battery casing body 1. Push plates 2 are fixedly connected to the upper ends of the two guide springs 4. The outer wall of the push plate 2 is tightly fitted to the inner wall of the battery casing body 1. The lower part of the push plate 2... A piston rod 6 is fixedly connected to the middle of the end face. The lower end of the piston rod 6 is slidably connected to the liquid injection and venting hole 17. A fixing ring 13 is fixedly connected to the lower end of the middle of the inner wall of the liquid injection and venting hole 17. A telescopic spring 14 is fixedly connected to both sides of the lower end face of the fixing ring 13. A sealing plate 16 is fixedly connected to the end of the two telescopic springs 14 away from the fixing ring 13. The end face of the sealing plate 16 near the telescopic spring 14 is in contact with the lower end face of the battery casing body 1. A sealing screw sleeve 15 is threadedly connected to the middle of the sealing plate 16.

[0026] The small cylindrical lithium-ion battery casing features a unique liquid injection and venting port 17 design, enabling precise control of the battery's internal environment. The venting function automatically activates when increased pressure occurs due to gas production from chemical reactions inside the battery. This activates the push plate 2 and piston rod 6, lifting the sealing plate 16 and allowing the gas to escape smoothly. This effectively reduces internal battery pressure, preventing the risk of explosion-proof valve rupture. Simultaneously, it improves the physical contact between the electrodes and the separator, reduces bubble formation, enhances lithium-ion transport efficiency, significantly improves cycle performance, rate performance, and capacity, and greatly extends battery life. The liquid injection and venting port 17 allows operators to easily add electrolyte when needed, ensuring smooth liquid flow and effectively preventing gas leakage, maintaining a stable internal environment. This design not only improves battery production efficiency and quality but also greatly facilitates later maintenance and performance adjustments. It allows for flexible adjustments and optimizations during use according to actual needs, comprehensively improving battery safety and reliability and providing a solid guarantee for stable battery operation.

[0027] Furthermore, such as Figures 1 to 4 As shown, each of the two guide springs 4 has a guide rod 3 inside. The lower end of the guide rod 3 is fixedly connected to the battery casing body 1, and the upper end of the guide rod 3 passes through the push plate 2 and is fixedly connected to the limit plate 5. The guide rod 3 and the push plate 2 are slidably connected, and a sealing structure is provided at the connection. A through hole 7 is opened in the middle of the piston rod 6. The upper end of the through hole 7 passes through the push plate 2. A mounting bracket 8 is fixedly connected to the upper end of the inner wall of the through hole 7. A connecting spring 9 is fixedly connected to the middle of the lower end face of the mounting bracket 8. A ball head 18 is fixedly connected to the lower end of the spring 9. A top plate 10 is rotatably connected to the lower end of the ball head 18. The outer wall of the top plate 10 is tightly fitted with the inner wall of the through hole 7. The upper and lower ends of the outer wall of the top plate 10 are provided with rounded corners. A baffle 11 is fixedly connected to the upper side of the middle part of the inner wall of the through hole 7. A retaining ring 19 is fixedly connected to the upper end of the inner wall of the through hole 7. A push rod 12 is fixedly connected to both sides of the lower end of the piston rod 6. The side of the push rod 12 near the sealing plate 16 is spherical.

[0028] Venting process: During battery use, as internal chemical reactions proceed, gas may be generated inside the battery, causing the internal pressure to gradually increase. When this internal pressure reaches a certain level, a clever design mechanism comes into play. First, the increased pressure pushes the top plate 10 to slide smoothly inside the through hole 7. This movement of the top plate 10 essentially plays a role in pressure deviation adjustment, effectively mitigating the impact caused by a sudden increase in internal pressure. However, the sliding of the top plate 10 is not unlimited; as it continues to move and deviates from the pre-set... When the baffle 11 located in the middle of the inner wall of the through hole 7 comes into contact with the top plate 10, the baffle 11 plays a crucial blocking role. Since the outer corners of the top plate 10 are rounded, when the lower end of the baffle 11 contacts the top plate 10 via the elastic force of the connecting spring 9, the top plate 10 will flip. At this time, the gas inside the housing can enter the through hole 7, achieving the purpose of pressure deviation adjustment. As the internal pressure continues to increase, the internal pressure will be transmitted to the push plate 2. After being subjected to this pressure, the push plate 2 will begin to compress the guide spring 4 below it. As an elastic element, 4 can effectively absorb and buffer this pressure change. At the same time, it also guides the push plate 2 to slide smoothly on the guide rod 3. The guide rod 3 not only provides precise guidance for the movement of the push plate 2, but also ensures the sealing performance during the movement through its sliding connection and sealing structure with the push plate 2. As the push plate 2 moves downward, it drives the piston rod 6 to move downward together. The spherical design of the push rod 12 at the lower end of the piston rod 6 allows it to form point contact when it contacts the sealing plate 16, thus making it easier to push up the sealing plate 16. When the push rod 12 successfully pushes up the sealing plate 16, the seal between the sealing plate 16 and the lower end face of the battery casing 1 is broken, forming a tiny gap. This gap provides a smooth passage for the gas inside the battery to escape, allowing the gas to escape smoothly from inside the battery casing 1, thereby effectively reducing the internal pressure and avoiding potential safety hazards. After the gas inside the casing is released, the push plate 10 is pulled back by the tension of the connecting spring 9 and comes into contact with the retaining ring 19 to complete the seal, preparing for the next pressure deviation adjustment.

[0029] Electrolyte Addition Process: When the battery needs electrolyte addition, a simple and efficient method is adopted. First, the sealing sleeve 15 is gently turned off the sealing plate 16 by using a wrench or other tools, thereby releasing the fixing effect on the sealing plate 16. Next, the electrolyte addition tube is accurately inserted into the through hole 7 and comes into contact with the top plate 10. Then, the top plate 10 is deflected, which realizes the electrolyte addition work and replenishes the battery with the required electrolyte. After the electrolyte addition work is completed, the top plate 10 is reset by the retaining ring 19, which ensures that the gas inside the battery casing 1 will not be discharged to the outside of the battery casing 1 through the top plate 10. This ingenious design not only ensures the smooth progress of the electrolyte addition process, but also effectively prevents the leakage of gas inside the battery, thereby maintaining the stability of the battery's internal environment.

[0030] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.

[0031] This utility model is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A hermetically sealable, vented, small cylindrical lithium-ion battery case, characterized by: The utility model provides a battery shell body (1) is provided with the injection liquid exhaust hole (17) in the lower end middle part, and the injection liquid exhaust hole (17) can be used for injecting liquid to the inside of battery shell body (1) and discharging the gas in the inside of battery shell body (1), the inside bottom surface middle part of battery shell body (1) is fixedly connected with the guide spring (4) on both sides, the upper end of two guide springs (4) is fixedly connected with the push plate (2), the outer wall of push plate (2) is closely combined with the inner wall of battery shell body (1), the lower end surface middle part of push plate (2) is fixedly connected with the piston rod (6), the lower end of piston rod (6) is connected in the injection liquid exhaust hole (17) in sliding, the inner wall middle part lower end of injection liquid exhaust hole (17) is fixedly connected with the fixed ring (13), the lower end surface both sides of fixed ring (13) are fixedly connected with the telescopic spring (14), one end of two telescopic springs (14) away from fixed ring (13) is fixedly connected with the sealing plate (16), the side end surface of sealing plate (16) close to telescopic spring (14) is in contact with the lower end surface of battery shell body (1), the middle part of sealing plate (16) is threadedly connected with the sealing screw sleeve (15).

2. A hermetically sealable cylindrical lithium-ion battery case according to claim 1, wherein: The inside of two guide springs (4) is provided with guide rod (3), the lower end of guide rod (3) is fixedly connected with battery shell body (1), the upper end of guide rod (3) penetrates push plate (2) and is fixedly connected with limiting plate (5).

3. A hermetically sealable vented small cylindrical lithium-ion battery case according to claim 2, characterized in that: The guide rod (3) is connected with push plate (2) in sliding and is provided with sealing structure at the connecting place.

4. A hermetically sealable vented small cylindrical lithium-ion battery case according to claim 1, wherein: The middle part of piston rod (6) is provided with through hole (7), the upper end of through hole (7) penetrates push plate (2).

5. A hermetically sealable vented small cylindrical lithium-ion battery case according to claim 4, characterized in that: The inner wall upper end of through hole (7) is fixedly connected with mounting bracket (8), the lower end surface middle part of mounting bracket (8) is fixedly connected with connecting spring (9), the lower end of connecting spring (9) is fixedly connected with ball head (18), the lower end of ball head (18) is rotatably connected with top plate (10), the outer wall of top plate (10) is closely combined with the inner wall of through hole (7), and the outer wall of top plate (10) is provided with round corner on the upper end.

6. A hermetically sealable vented small cylindrical lithium-ion battery case according to claim 5, characterized in that: The inner wall middle part of through hole (7) is fixedly connected with baffle (11) on one side close to the upper end, the inner wall of through hole (7) is fixedly connected with baffle ring (19) on the upper end of top plate (10).

7. A hermetically sealable vented small cylindrical lithium-ion battery case according to claim 1, wherein: The lower end both sides of piston rod (6) are fixedly connected with jacks (12), and the side close to sealing plate (16) of jacks (12) is spherical.

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