Lithium battery PACK pressure relief structure

Abstract

The utility model provides a lithium battery PACK pressure relief structure, which belongs to the technical field of lithium battery, the lithium battery PACK pressure relief structure comprises a Pack assembly, a welding elbow, a connecting pipe and an explosion-proof valve, the side wall of the Pack assembly is provided with a cabinet door, the welding elbow is a 90-degree welding elbow, the welding elbow is provided with a pipe thread, and the explosion-proof valve is connected with the cabinet door. The welding elbow comprises a first elbow and a second elbow, one end of the first elbow is directly connected with the Pack assembly through a pipe thread, the other end of the first elbow is connected with the connecting pipe through a pipe thread, the other end of the connecting pipe is connected to the second elbow, and the other end of the second elbow is connected to the explosion-proof valve through the cabinet door. The explosion-proof valves are arranged on the outer sides of the cabinet doors, the number of the cabinet doors is matched with the number of the Pack assemblies, the connecting pipes are made of stainless steel, the outer surfaces of the connecting pipes are corrugated pipes of stainless steel woven meshes, and potential safety hazards caused by thermal runaway of a traditional lithium battery are avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium batteries, and specifically relates to a lithium battery PACK pressure relief structure. Background Art

[0002] With the accelerating promotion of the global energy transformation, the wide application of renewable energy has promoted energy storage technology to become a key component of the power system. Lithium batteries, as an efficient and portable energy storage solution, play a core role in energy storage systems. A lithium battery Pack (or simply Li-ion Pack) refers to a battery pack formed by combining multiple lithium-ion battery cells (cores) through certain electrical and mechanical means, with higher energy density, larger capacity or higher voltage. However, lithium batteries inevitably generate heat during operation. Especially for high-power and high-energy-density lithium batteries during high-current discharge or rapid charging, the internal chemical reactions intensify, resulting in a significant increase in the temperature of the cores. Although the selection and ratio of components such as the positive electrode material, negative electrode material, and electrolyte of lithium batteries have been optimized to improve energy density and cycle life, their inherently poor thermal conductivity remains an unavoidable problem.

[0003] In practical applications, although lithium battery energy storage systems are generally equipped with cooling and heat dissipation systems, including air cooling, liquid cooling, heat pipe cooling, etc., under extreme conditions, such as rapid charging and discharging, too high ambient temperature or heat dissipation system failure, the accumulation of heat inside the cores often cannot be effectively suppressed. Once the temperature of the cores exceeds the safety threshold, thermal runaway may occur. Thermal runaway is a catastrophic failure mode of lithium batteries. It starts with local overheating of a certain core, and then triggers a series of chemical reactions, such as the decomposition of the SEI film, the decomposition of the electrolyte, the decomposition of the positive and negative electrode materials, etc. These reactions will release a large amount of heat, further increasing the temperature of the cores, forming a vicious cycle, and ultimately may lead to a sharp rise in the internal pressure of the battery, and even combustion or explosion, causing chain damage to other electrical components and the Pack inside the energy storage cabinet. Summary of the Utility Model

[0004] In view of this, the utility model provides a lithium battery PACK pressure relief structure to solve the safety hazards caused by thermal runaway of traditional lithium batteries and improve the safety and reliability of the energy storage system.

[0005] The utility model is implemented as follows:

[0006] The present utility model provides a pressure relief structure for a lithium battery PACK, which includes a Pack assembly, a welded elbow, a connecting pipe, and an explosion-proof valve. A cabinet door is provided on the side wall of the Pack assembly. The welded elbow is a 90° welded elbow, and the welded elbow is provided with a pipe thread. The welded elbow includes a first elbow and a second elbow. One end of the first elbow is directly connected to the Pack assembly through the pipe thread, and the other end is connected to the connecting pipe through the pipe thread. The other end of the connecting pipe is connected to the second elbow, and the other end of the second elbow is connected to the explosion-proof valve through the cabinet door. The explosion-proof valve is arranged outside the cabinet door, and the number of cabinet doors matches the number of Pack assemblies.

[0007] The technical effects of the pressure relief structure for a lithium battery PACK provided by the present utility model are as follows: By integrating a high-performance explosion-proof exhaust system, the present utility model can effectively cope with the high-pressure and high-temperature gas generated during the thermal runaway of the battery cells, timely guide it to a safe area, significantly reduce the internal pressure of the energy storage cabinet, avoid explosion or fire accidents, and greatly improve the safety level of the entire energy storage system.

[0008] On the basis of the above technical solution, the pressure relief structure for a lithium battery PACK of the present utility model can be further improved as follows:

[0009] Among them, the connecting pipe is made of stainless steel, and the outer surface of the connecting pipe is a corrugated pipe with a stainless steel braided mesh.

[0010] The beneficial effects of adopting the above improvement scheme are: By adopting the design of a corrugated pipe with a stainless steel braided mesh, the present utility model not only enhances the mechanical strength and thermal shock resistance of the connecting pipe, but also optimizes the thermal management efficiency, can better adapt to the thermal expansion and contraction of the battery cells during operation, ensure that the battery cells operate within a safe temperature range, thereby extending the battery life and improving the overall operation efficiency of the system.

[0011] Further, both the welded elbow and the connecting pipe are multiple. Specifically, each connecting pipe is matched with two welded elbows.

[0012] Further, the number of connecting pipes is the same as the number of Pack assemblies.

[0013] Further, both ends of the connecting pipe are respectively connected to the first elbow at the Pack assembly and the second elbow at the cabinet door.

[0014] Further, the connection between the welded elbow and the connecting pipe adopts a double-layer sealing structure, including a first layer of sealing and a second layer of sealing.

[0015] The implementation methods of the double-layer sealing structure include but are not limited to using O-rings, lip seals, etc.

[0016] The innovative double - layer sealing structure design, including static sealing and dynamic sealing, ensures airtightness under normal working and extreme conditions, effectively preventing gas leakage. Even under the impact of high - pressure gas, the system can remain stable, greatly enhancing the overall reliability of the energy storage system.

[0017] The sealing structure design of this utility model takes into account the convenience of maintenance, making the replacement of seals quick and simple, reducing maintenance costs and downtime. At the same time, its flexible structure design makes this explosion - proof exhaust system easy to integrate with existing energy storage systems. Whether for newly built equipment or upgrading of old systems, it can be easily achieved, improving the system's compatibility and scalability.

[0018] Furthermore, the first - layer seal of the double - layer sealing structure is a static seal, and the first - layer seal is embedded in the contact surface between the connecting pipe and the welded elbow.

[0019] Furthermore, the second - layer seal of the double - layer sealing structure is a dynamic seal, and the second - layer seal is designed with a spring - loaded metal gasket.

[0020] When high - pressure gas passes through, the dynamic gasket of the second - layer seal clings to the inner wall of the stainless - steel connecting pipe under the action of gas pressure, further enhancing the sealing effect.

[0021] Furthermore, the thickness of the first - layer seal is greater than the thickness of the second - layer seal and less than twice the thickness of the second - layer seal.

[0022] Furthermore, the total length of the double - layer sealing structure is less than or equal to twice the diameter of the interface between the connecting pipe and the welded elbow.

[0023] Compared with the prior art, the beneficial effects of a lithium - battery PACK pressure - relief structure provided by this utility model are:

[0024] Immediate response and safe pressure relief: When the internal pressure rises due to thermal runaway of the battery cell, the explosion - proof valve can respond quickly and open in time, discharging the high - temperature combustible gas through a pre - designed stainless - steel high - temperature and high - pressure pipeline out of the energy storage cabinet, avoiding the continuous accumulation of internal pressure and reducing the risk of explosion;

[0025] Precise control and intelligent monitoring: Combined with an advanced battery management system (BMS), this invention can real - time monitor key parameters such as the temperature, voltage, and current of the battery cell. Once an abnormal situation is detected, corresponding safety measures are immediately initiated, such as cutting off the power supply, activating the cooling system, or starting the explosion - proof exhaust mechanism, thereby effectively preventing the occurrence of thermal runaway;

[0026] Enhanced Structural Stability and Safety: By adopting a high-strength stainless steel braided mesh corrugated pipe as the connecting pipe, the present invention not only improves the mechanical strength of the entire exhaust system, but also can adapt to thermal expansion and contraction under different working conditions, ensuring the stability and safety of the system under various extreme working conditions;

[0027] Double-layer Sealing Guarantee: The innovative double-layer sealing structure, including static sealing and dynamic sealing, ensures airtightness during normal operation and emergency situations, prevents leakage of high-temperature gases, and also reduces maintenance costs and frequencies. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the description of the embodiments of the present utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is an example diagram of a pressure relief structure of a lithium battery PACK;

[0030] Figure 2 It is a connection diagram of the Pack components of a pressure relief structure of a lithium battery PACK;

[0031] In the drawings, the list of components represented by each reference numeral is as follows:

[0032] 10. Pack components; 20. Welded elbow; 21. First elbow; 22. Second elbow; 30. Connecting pipe; 40. Explosion-proof valve; 50. Cabinet door. Detailed Embodiments

[0033] To make the purposes, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model.

[0034] Such as Figure 1 、 Figure 2As shown in the figure, it is the first embodiment of a lithium battery PACK pressure relief structure provided by the present utility model. In this embodiment, it includes a Pack assembly 10, a welded elbow 20, a connecting pipe 30, and an explosion-proof valve 40. A cabinet door 50 is provided on the side wall of the Pack assembly 10. The welded elbow 20 is a 90° welded elbow, and the welded elbow 20 is provided with a pipe thread. The welded elbow 20 includes a first elbow 21 and a second elbow 22. One end of the first elbow 21 is directly connected to the Pack assembly 10 through the pipe thread, and the other end is connected to the connecting pipe 30 through the pipe thread. The other end of the connecting pipe 30 is connected to the second elbow 22, and the other end of the second elbow 22 is connected to the explosion-proof valve 40 through the cabinet door 50. The explosion-proof valve 40 is arranged outside the cabinet door 50, and the number of cabinet doors 50 matches the number of Pack assemblies 10.

[0035] Among them, in the above technical solution, the connecting pipe 30 is made of stainless steel, and the outer surface of the connecting pipe 30 is a corrugated pipe with a stainless steel braided mesh.

[0036] Further, in the above technical solution, both the welded elbow 20 and the connecting pipe 30 are multiple. Specifically, each connecting pipe 30 is matched with two welded elbows 20.

[0037] Further, in the above technical solution, the number of connecting pipes 30 is the same as the number of Pack assemblies 10.

[0038] Further, in the above technical solution, both ends of the connecting pipe 30 are respectively connected to the first elbow 21 at the Pack assembly 10 and the second elbow 22 at the cabinet door 50.

[0039] Further, in the above technical solution, the connection between the welded elbow 20 and the connecting pipe 30 adopts a double-layer sealing structure, including a first layer of seal and a second layer of seal.

[0040] During use, steps for the O-ring implementation:

[0041] The first layer of static seal of the double-layer sealing structure is realized by an O-ring, and its specific implementation steps are as follows:

[0042] According to the connection dimensions between the stainless steel connecting pipe and the 90° welded elbow of part 2, select a suitable O-ring material and size to ensure that the O-ring can maintain elasticity and provide sealing under a predetermined pressure.

[0043] Machine a sealing groove matching the O-ring on the contact surface between the stainless steel connecting pipe and the welded elbow or the explosion-proof valve. The depth and width of the groove should be accurately calculated to ensure that the O-ring can be properly compressed during installation without being damaged.

[0044] Install the O-ring into the sealing groove, ensuring that the O-ring is evenly placed without distortion to prevent uneven sealing pressure.

[0045] Using appropriate tools and lubricants (if required), align and tighten the welded elbow or explosion-proof valve with the stainless steel connecting pipe until the O-ring is sufficiently compressed, but avoid over-compression that may damage the O-ring.

[0046] Implementation steps for the lip seal:

[0047] The second layer of dynamic seal in the double-seal structure is achieved by using a lip seal. The specific implementation steps are as follows:

[0048] Select a lip seal material that matches the working conditions (such as temperature, pressure, and medium properties), such as polyurethane, nitrile rubber, or fluororubber.

[0049] Design the shape and angle of the lip of the lip seal to ensure that under the action of gas pressure, the lip can tightly fit the inner wall of the stainless steel connecting pipe to form a dynamic seal.

[0050] Machine a guiding groove for the lip seal on the inner wall of the stainless steel connecting pipe to ensure that the lip seal can slide freely after installation but will not fall off due to vibration.

[0051] Install the lip seal, ensure that its lip is correctly aligned with the guiding groove, and gently push it in using a special tool to avoid damaging the lip.

[0052] Adjust the pre-compression amount of the lip seal to ensure that there is a slight contact pressure between the lip and the inner wall of the stainless steel connecting pipe in the non-pressure state to reduce the possibility of leakage.

[0053] Furthermore, in the above technical solution, the first layer of seal in the double-seal structure is a static seal, and the first layer of seal is embedded in the contact surface between the connecting pipe 30 and the welded elbow 20.

[0054] Furthermore, in the above technical solution, the second layer of seal in the double-seal structure is a dynamic seal, and the second layer of seal is designed with a spring-loaded metal gasket.

[0055] Implementation steps for the spring-loaded gasket

[0056] The dynamic seal in the double-seal structure can also be achieved by using a spring-loaded gasket. The specific implementation steps are as follows:

[0057] Select an appropriate spring material, such as stainless steel or phosphor bronze, to ensure that the spring can still maintain its elasticity in high-temperature and high-pressure environments.

[0058] Design the size and stiffness of the helical spring to ensure that under the expected working pressure, the spring can provide sufficient load to keep the gasket tightly against the inner wall of the stainless steel connecting pipe.

[0059] Manufacture a gasket, usually made of high-temperature resistant and corrosion-resistant materials such as graphite, carbon fiber composite materials, etc., to ensure that it fits perfectly with the inner wall of the stainless steel connecting pipe.

[0060] Machine spiral springs and positioning grooves for the gasket on the inner wall of the stainless steel connecting pipe to ensure that the springs and gaskets can be correctly aligned and the springs can apply force evenly under pressure.

[0061] Install the spiral spring and the gasket. First, place the gasket into the positioning groove, then slip the spiral spring over the gasket, and finally install the entire assembly onto the stainless steel connecting pipe to ensure that the gasket always tightly adheres to the inner wall under the action of the spring.

[0062] Furthermore, in the above technical solution, the thickness of the first layer of seal is greater than the thickness of the second layer of seal and less than twice the thickness of the second layer of seal.

[0063] Furthermore, in the above technical solution, the total length of the double-layer seal structure is less than or equal to twice the diameter of the interface between the connecting pipe 30 and the welded elbow 20.

[0064] Specifically, the principle of the present utility model is as follows: The core technical principle of the present utility model lies in achieving effective management and control of the thermal runaway phenomenon of the lithium battery energy storage system through a series of innovative designs. First, through optimized thermal management design, the temperature of the battery cells is ensured to be controllable under normal operating conditions; second, an advanced explosion-proof exhaust mechanism is adopted. Once thermal runaway occurs, it can quickly and safely guide the high-temperature combustible gas out of the energy storage cabinet, avoiding a sharp increase in internal pressure and explosion risk; third, through a precise double-layer seal structure, even under extreme working conditions, the airtightness and structural stability of the system can be maintained, preventing gas leakage and ensuring the safety of operators and the surrounding environment.

[0065] Specifically, the technical principle of the present utility model can be broken down into the following key points:

[0066] Thermal management mechanism: Utilize an efficient cooling system and an intelligent temperature monitoring and control system to adjust the operating temperature of the battery cells in real time and avoid thermal runaway caused by overheating.

[0067] Explosion-proof exhaust system: When thermal runaway occurs in the battery cells, the explosion-proof valve will automatically open, and the high-pressure gas will be guided to a safe area through a stainless steel high-temperature and high-pressure pipeline, effectively avoiding the accumulation of internal pressure and reducing the risk of explosion.

[0068] Double-layer seal structure: The dual design of the static sealing ring and the dynamic gasket can ensure the airtightness of the system even under the impact of high-pressure gas, prevent gas leakage, and at the same time improve the overall stability and reliability of the system.

[0069] Intelligent management: Combined with an advanced Battery Management System (BMS), it can monitor the status of the battery cells in real time. Once an anomaly is detected, immediate measures will be taken, including activating the cooling system, cutting off the power supply or activating the explosion-proof exhaust mechanism, thus achieving proactive management and prevention of thermal runaway phenomena.

Claims

1. A lithium battery PACK pressure relief structure, characterized in that: The invention comprises a Pack assembly (10), a welding elbow (20), a connecting pipe (30), and an explosion-proof valve (40); a cabinet door (50) is arranged on the side wall of the Pack assembly (10); the welding elbow (20) is a 90° welding elbow; the welding elbow (20) is provided with a pipe thread; the welding elbow (20) comprises a first elbow (21) and a second elbow (22); one end of the first elbow (21) is directly connected to the Pack assembly (10) via a pipe thread; the other end of the first elbow (21) is connected to the connecting pipe (30) via a pipe thread; the other end of the connecting pipe (30) is connected to the second elbow (22); the other end of the second elbow (22) is connected to the explosion-proof valve (40) via the cabinet door (50); the explosion-proof valve (40) is arranged on the outside of the cabinet door (50); the number of the cabinet doors (50) matches the number of the Pack assembly (10).

2. A lithium battery PACK pressure relief structure according to claim 1, characterized in that: The connecting pipe (30) is made of stainless steel, and the outer surface of the connecting pipe (30) is a corrugated pipe of a stainless steel braided mesh.

3. A lithium battery PACK pressure relief structure according to claim 2, characterized in that: There are multiple welding elbows (20) and multiple connecting pipes (30). Specifically, each connecting pipe (30) is matched with two welding elbows (20).

4. A lithium battery PACK pressure relief structure according to claim 3, characterized in that: The number of the connecting pipes (30) is the same as the number of the Pack components (10).

5. A lithium battery PACK pressure relief structure according to claim 4, characterized in that: The two ends of the connecting pipe (30) are respectively connected to a first elbow (21) located at the Pack component (10) and a second elbow (22) located at the cabinet door (50).

6. A lithium battery PACK pressure relief structure according to claim 5, characterized in that: The connection between the welding elbow (20) and the connecting pipe (30) adopts a double-layer sealing structure, including a first layer of sealing and a second layer of sealing.

7. A lithium battery PACK pressure relief structure according to claim 6, characterized in that: The first sealing layer of the double-layer sealing structure is a static sealing layer, and the first sealing layer is embedded in the contact surface between the connecting pipe (30) and the welding elbow (20).

8. A lithium battery PACK pressure relief structure according to claim 7, characterized in that: The second seal of the double-layer seal structure is a dynamic seal, and the second seal is designed with a spring-loaded metal seal pad.

9. A lithium battery PACK pressure relief structure according to claim 8, characterized in that: The thickness of the first layer of seal is greater than the thickness of the second layer of seal and less than twice the thickness of the second layer of seal.

10. A lithium battery PACK pressure relief structure according to claim 9, characterized in that: The total length of the double-layer sealing structure is less than or equal to twice the diameter of the interface between the connecting pipe (30) and the welding elbow (20).

Images