Vent valves, battery packs, and electrical equipment

Abstract

This utility model relates to a vent valve, a battery pack, and an electrical device. The vent valve includes a body and a cover plate. The cover plate is connected to the body, and at least two connecting parts are provided between the cover plate and the body. The cover plate and the body are connected through the connecting parts, and the at least two connecting parts are distributed along the circumference of the vent valve. A vent hole is formed between two adjacent connecting parts. The connecting parts can be broken under preset conditions to detach the cover plate from the body, thereby increasing the exhaust volume of the body. The vent valve can expel high-temperature gas from the battery pack more quickly when the battery pack experiences thermal runaway.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a vent valve, a battery pack, and an electrical device. Background Technology

[0002] During operation, electric vehicle batteries typically experience a small amount of gas expansion due to internal heating. Therefore, a vent valve needs to be installed on the battery pack casing to quickly expel the gas and ensure that the internal temperature of the battery pack remains stable. However, when the battery temperature becomes too high and thermal runaway occurs, it is necessary to expel the high-temperature gas inside the battery pack even faster to prevent the battery pack from exploding. At this time, the opening of the vent valve is limited and cannot maximize the amount of gas expelled. Therefore, how to expel the high-temperature gas from the battery pack as quickly as possible in the event of thermal runaway is an urgent technical problem to be solved. Utility Model Content

[0003] Based on the above-mentioned technical problems, this utility model provides a vent valve, a battery pack, and an electrical device to expel high-temperature gas from the battery pack more quickly in the event of thermal runaway, thereby at least partially solving the above-mentioned technical problems.

[0004] In one aspect, this utility model provides a vent valve, the vent valve comprising: a body; a cover plate connected to the body, wherein at least two connecting portions are provided between the cover plate and the body, the cover plate and the body are connected by the connecting portions, and at least two of the connecting portions are distributed along the circumference of the vent valve, and a vent hole is formed between two adjacent connecting portions, wherein the connecting portions can be broken under preset conditions to detach the cover plate from the body, thereby increasing the exhaust volume of the body.

[0005] Through the above technical solution, namely the vent valve provided by this utility model, when one end of the vent valve body is connected to the battery pack shell, under normal battery pack operation, the gas generated by the thermal expansion inside the battery pack can be normally discharged from the flow channel inside the vent valve body to the vent hole between the body and the cover plate and discharged. Furthermore, the two adjacent connecting parts on both sides of the vent hole can also ensure the overall structural strength of the vent valve. However, when the battery is operating under high load and the temperature is too high, resulting in thermal runaway, the internal temperature of the battery is high and the gas content is high, requiring faster gas discharge from the vent valve. When the gas expands, the pressure and temperature of the gas flowing through the vent valve will also increase accordingly. When the pressure of the gas flowing through the vent valve exceeds the maximum pressure that the connection can withstand, or the temperature of the gas flowing through the vent valve exceeds the maximum temperature that the connection can withstand (i.e., under the above preset conditions), the connection can be damaged (e.g., it can be melted or stretched and broken), thereby allowing the cover to detach from the body. After the cover detaches from the body, the exhaust volume of the body can be further increased, and the high-temperature gas inside the battery pack can be discharged from the body to the outside more quickly, thereby improving the exhaust efficiency of the battery pack during thermal runaway.

[0006] The specific beneficial effects of other embodiments of this utility model will be explained in the following detailed description. Attached Figure Description

[0007] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of the structure of the vent valve provided in an exemplary embodiment of the present utility model;

[0009] Figure 2 This is a schematic diagram of the structure of the body and connecting part provided in an exemplary embodiment of this utility model;

[0010] Figure 3 This is a schematic diagram of the structure of the cover plate provided in an exemplary embodiment of the present utility model;

[0011] Figure 4 This is a schematic diagram of the battery pack provided in an exemplary embodiment of the present utility model;

[0012] Figure 5 for Figure 4 A magnified view of a portion of position A in the middle.

[0013] Explanation of reference numerals in the attached figures:

[0014] 1. Ontology;

[0015] 2. Cover plate;

[0016] 3. Connecting parts;

[0017] 4. Ventilation holes;

[0018] 5. Shell. Detailed Implementation

[0019] 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 with reference to the accompanying drawings. 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.

[0020] In related technologies, during the operation of electric vehicle batteries, a small amount of gas expansion occurs due to internal heating of the battery pack. Therefore, a vent valve needs to be installed on the battery pack casing to quickly expel the gas and ensure that the internal temperature of the battery pack remains stable. However, when the battery temperature becomes too high and thermal runaway occurs, it is necessary to expel the high-temperature gas inside the battery pack even faster to prevent the battery pack from exploding. At this time, the opening of the vent valve is limited and cannot maximize the amount of gas expelled. Therefore, how to expel the high-temperature gas from the battery pack as quickly as possible in the event of thermal runaway is an urgent technical problem to be solved.

[0021] In view of the above-mentioned technical problems, the first aspect of this utility model provides a breathable valve, as shown in the reference. Figures 1 to 5 As shown, the vent valve includes a body 1 and a cover plate 2. The cover plate 2 is connected to the body 1. At least two connecting parts 3 are provided between the cover plate 2 and the body 1. The cover plate 2 and the body 1 are connected by the connecting parts 3. The at least two connecting parts 3 are distributed along the circumference of the vent valve. A vent hole 4 is formed between two adjacent connecting parts 3. The connecting parts 3 can be broken under preset conditions to detach the cover plate 2 from the body 1, thereby increasing the exhaust volume of the body 1.

[0022] Through the above technical solution, namely the vent valve provided by this utility model, when one end of the vent valve body 1 is connected to the battery pack shell, under normal battery pack operation, the gas generated by the thermal expansion inside the battery pack can be normally discharged from the flow channel inside the vent valve body 1 to the vent hole 4 between the body 1 and the cover plate 2 and discharged. Furthermore, the two adjacent connecting parts 3 on both sides of the vent hole 4 can also ensure the overall structural strength of the vent valve. However, when the battery is operating under high load and the temperature is too high, resulting in thermal runaway, the internal temperature of the battery is high and the gas content is high, requiring faster gas discharge from the vent valve. When the gas pressure and temperature of the gas flowing through the vent valve increase, the gas pressure and temperature of the gas flowing through the vent valve will also increase accordingly. When the gas pressure flowing through the vent valve exceeds the maximum pressure that the connecting part 3 can withstand, or when the gas temperature flowing through the vent valve exceeds the maximum temperature that the connecting part 3 can withstand (i.e., the above-mentioned preset conditions are met), the connecting part 3 can be destroyed (for example, it can be melted or stretched and broken), thereby allowing the cover plate 2 to detach from the body 1. After the cover plate 2 detaches from the body 1, the exhaust volume of the body can be further increased, and the high-temperature gas inside the battery pack can be discharged from the body 1 more quickly, thereby improving the exhaust efficiency of the battery pack during thermal runaway.

[0023] It should be noted that, in the above embodiments, the preset conditions under which the connecting part 3 can be destroyed can be any suitable condition. For example, when the connecting part 3 is made of different types of materials, the heat resistance temperature and tensile strength of the connecting part 3 can also be adapted to change. For example, when the connecting part 3 is made of rubber and metal materials respectively, the heat resistance temperature and tensile strength are also different. The connecting part 3 can be made of any suitable material according to the actual situation. This embodiment does not make any specific limitation in this regard.

[0024] For example, the above-mentioned preset conditions may include: the tensile strength of the connecting part 3 is greater than or equal to 30 kPa.

[0025] In the above manner, the preset conditions can include tensile strength factors. That is, 30 kPa can be the maximum tensile strength that the connecting part 3 is subjected to, or it can be the maximum impact of gas that the connecting part 3 can withstand. That is, it can be understood that when gas is discharged from inside the battery pack through the vent valve, part of the gas will be discharged through the vent hole 4, and the other part will impact the cover plate 2 connected to one end of the body 1. The maximum tensile strength can also be understood as the highest limit that the cover plate 2 can be stably connected to the body 1 through the connecting part 3. Once this upper limit is exceeded, the connecting part 3 will be broken by the huge impact of the gas, and the cover plate 2 can then be separated from the body 1, thereby increasing the exhaust volume of the body 1.

[0026] Based on the above, it can be understood that when the battery in the battery pack is working normally, the connecting part 3 can act as a reinforcing rib to improve the structural strength of the vent valve itself. When the battery pack experiences thermal runaway, the connecting part 3 can also break quickly to increase the vent valve's exhaust volume.

[0027] Furthermore, the vent valve can also use existing mature venting methods for venting. For example, a moisture-blocking structure can be set inside the vent valve, which is actually a two-way switch. A valve is set at the inlet and outlet of the vent valve. When one of the two directions of the inlet and outlet of the vent valve meets the preset pressure value, the corresponding valve can be opened to allow normal venting through the vent valve.

[0028] Furthermore, to ensure that the connection part 3 can both maintain structural strength and rapidly break during battery pack thermal runaway, reference can be made to... Figures 1 to 3 As shown, in the direction perpendicular to the length of the vent valve, the ratio of the projected area of ​​the maximum cross-section of the connecting part 3 to the projected area of ​​the minimum cross-section of the vent valve is A, where A is less than or equal to 20%; and / or, the ratio of the projected area of ​​the minimum cross-section of the connecting part 3 to the projected area of ​​the maximum cross-section of the vent valve is B, where B is greater than or equal to 3%.

[0029] As can be seen from the above, the ratio A is the upper limit of the connecting part 3 in the overall cross-section of the vent valve. If the ratio is higher than A, the vent valve's permeability will decrease, meaning the diameter or number of vent holes 4 is too small, affecting the vent valve's exhaust efficiency during normal exhaust. The ratio B is the lower limit of the connecting part 3 in the overall cross-section of the vent valve. If the ratio is lower than B, although the vent valve's permeability is improved (i.e., the diameter or number of vent holes 4 increases), the proportion of the connecting part 3 decreases, which will reduce the connection performance between the cover plate 2 and the body 1. Consequently, during normal exhaust, the gas is more likely to break the connecting part 3, thus failing to achieve the effect of improving the structural strength of the vent valve through the connecting part 3.

[0030] It should be noted that the ratios A and B mentioned above are exemplary, for example, in... Figure 1In the example shown, the cross-section of the vent valve provided by this utility model is circular in the length direction. In this embodiment, the ratio A can be the upper limit and the ratio B can be the lower limit. In the embodiment not shown in the figure, the cross-section of the vent valve can also be other shapes, such as rectangular or irregular shapes. In this case, the upper and lower limits of the above ratio can be changed according to the actual situation. Moreover, the above ratio can also be applied to vent valves with variable cross-sections along the length direction of the vent valve. That is, no matter how the cross-sectional size of the vent valve changes, as long as the connecting part 3 is at the upper and lower limits of the corresponding cross-section, the connecting part 3 can improve the structural strength of the vent valve without affecting the exhaust efficiency under normal conditions.

[0031] In some implementations, reference Figures 1 to 3 As shown, the vent 4 is constructed as a strip-shaped hole extending circumferentially along the vent valve.

[0032] By employing the above method and arranging the slotted holes, the air volume during normal exhaust can be further increased, which can be referenced. Figure 1 As shown, multiple connecting parts 3 can also be arranged at intervals along the circumference of the vent valve, and a strip-shaped vent hole 4 is formed between any two adjacent connecting parts 3. In this arrangement, when the battery pack is working normally, the discharged gas can be discharged through multiple strip-shaped vent holes 4, thereby ensuring that the battery pack can stably discharge gas when it generates heat and gas.

[0033] It should be noted that the above-described implementation of the strip-shaped hole is exemplary. In the embodiment not shown in the figure, the vent hole 4 can also be other shapes, such as circular, square or irregular. Since the exhaust volume is different under various types of working conditions, it is only necessary to ensure that the exhaust can be stably discharged through the vent hole 4 of various suitable shapes when the battery pack is working normally.

[0034] Furthermore, the number of vents and connections can be chosen arbitrarily according to the actual exhaust volume, and is not limited to any specific number. Figures 1 to 3 The figure shows four vent holes and four connecting parts. In the embodiment not shown in the figure, the number of connecting parts 3 and vent holes 4 can also be other suitable numbers. The number of connecting parts 3 and vent holes 4 can be the same or different. This embodiment does not make a specific limitation on this.

[0035] In this embodiment, the connecting part 3 can be made of one or more of the following materials: PBT and glass fiber, ABS, ABS and glass fiber, PC, PC and ABS, and glass fiber. In this way, the connecting part made of the above materials can not only improve the overall structural strength of the vent valve during normal exhaust, but also self-destruct when the vent valve needs a larger exhaust volume and meets any of the above preset conditions, thereby increasing the exhaust volume of the main body. Since the above materials are relatively mature materials in the prior art, those skilled in the art can easily use the above materials to make the connecting part 3. Therefore, the above materials will not be described in detail in this embodiment.

[0036] In some implementations, reference Figures 1 to 3 As shown, one end of the connecting part 3 is integrally formed with the cover plate 2, and the other end is detachably connected to the body 1; or, one end of the connecting part 3 is integrally formed with the body 1, and the other end is detachably connected to the cover plate 2; or, the cover plate 2, the body 1 and the connecting part 3 are integrally formed.

[0037] As can be clearly seen from the above, the cover plate 2, the body 1, and the connecting part 3 can be combined or connected in any suitable way. For example, when one end of the connecting part 3 is integrally formed with the cover plate 2 and the other end is detachably connected to the body 1, the cover plate 2 can be directly molded integrally with the connecting part and connected to the body 1 during manufacturing. When one end of the connecting part 3 is integrally formed with the body 1, the body 1 can also be molded integrally with the connecting part 3 and connected to the cover plate 2 during manufacturing. When the cover plate 2, the body 1, and the connecting part 3 are all integrally formed, they can be directly connected into one unit using a mold, such as injection molding or any other suitable manufacturing method. Those skilled in the art can choose any suitable combination method according to the actual situation, as long as the assembly difficulty or manufacturing difficulty of the vent valve can be reduced as much as possible during the manufacturing process.

[0038] Furthermore, when the connecting part 3 is detachably connected to the body 1, or when the connecting part 3 is detachably connected to the cover plate 2, any suitable fitting method can be used at the connection between the connecting part 3 and the body 1 or the connection between the connecting part 3 and the cover plate 2. For example, any suitable method such as plugging, riveting, or welding can be used. This embodiment does not impose too many limitations on this.

[0039] Understandably, the vent valve of this utility model is equipped with a waterproof, breathable and moisture-proof structure, which can prevent water and moisture from entering the battery pack through the vent valve and forming condensation.

[0040] A second aspect of this utility model provides a battery pack, as referenced. Figures 1 to 5As shown, the battery pack includes a housing 5, battery cells disposed within the housing 5, and a vent valve mentioned in the above embodiments. The vent valve is disposed on the housing 5, and the battery pack also has all the beneficial effects of the above embodiments, which will not be elaborated further in this embodiment.

[0041] In some embodiments, a plurality of vent valves are arranged at intervals on the battery pack housing 5.

[0042] By employing the above-described method and arranging multiple vent valves, gas can be discharged from multiple different locations within the battery pack. This improves the stability of gas discharge during normal operation, enhances the battery pack's safety performance, and, in the event of thermal runaway, can increase the venting capacity of the vent valves by disrupting the connecting parts 3 on multiple vent valves, or at least partially disrupting the connecting parts 3 on several vent valves. This allows high-temperature gas to be discharged from the battery pack's casing 5 as quickly as possible, thereby reducing or preventing further damage to the battery pack.

[0043] In a third aspect, this embodiment provides an electrical device that includes the battery pack mentioned in the above-described embodiments. This electrical device also has all the beneficial effects described in the above embodiments, which will not be elaborated further in this embodiment. Furthermore, the electrical device can be any device that can be applied to the battery pack, such as a mobile phone, tablet computer, or power bank in a smart device; it can also be a lighting device such as a flashlight or work light; or it can be a cooking device such as an electric cooker, electric baking pan, or rice cooker, etc. This embodiment does not impose any limitations on these.

[0044] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A vent valve, characterized in that, The vent valve includes: Ontology(1); A cover plate (2) is connected to the body (1). At least two connecting parts (3) are provided between the cover plate (2) and the body (1). The cover plate (2) and the body (1) are connected through the connecting parts (3). At least two connecting parts (3) are distributed around the vent valve. A vent hole (4) is formed between two adjacent connecting parts (3). The connecting parts (3) can be destroyed under preset conditions so that the cover plate (2) is separated from the body (1), thereby increasing the exhaust volume of the body (1).

2. The vent valve according to claim 1, characterized in that, The preset conditions include: the tensile strength of the connecting part (3) is greater than or equal to 30 kPa.

3. The vent valve according to claim 1, characterized in that, In the direction perpendicular to the length of the vent valve, the ratio of the projected area of ​​the maximum cross-section of the connecting portion (3) to the projected area of ​​the minimum cross-section of the vent valve is A, where A is less than or equal to 20%; and / or, The ratio of the projected area of ​​the minimum cross section of the connecting part (3) to the projected area of ​​the maximum cross section of the vent valve is B, and B is greater than or equal to 3%.

4. The vent valve according to claim 3, characterized in that, The vent hole (4) is constructed as a strip-shaped hole extending circumferentially along the vent valve.

5. The vent valve according to any one of claims 1-3, characterized in that, The connecting part (3) is made of one or more of the following materials: PBT and glass fiber, ABS, ABS and glass fiber, PC, PC and ABS, and glass fiber.

6. The vent valve according to claim 1, characterized in that, One end of the connecting part (3) is integrally formed with the cover plate (2), and the other end is detachably connected to the body (1); or, One end of the connecting part (3) is integrally formed with the body (1), and the other end is detachably connected to the cover plate (2).

7. The vent valve according to claim 1, characterized in that, The cover plate (2), the body (1) and the connecting part (3) are integrally formed.

8. A battery pack, characterized in that, It includes a housing (5), a battery cell disposed within the housing (5), and a vent valve as described in any one of claims 1-7, the vent valve being disposed on the housing (5).

9. The battery pack according to claim 8, characterized in that, The number of vent valves is multiple and they are arranged at intervals on the housing (5) of the battery pack.

10. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 8-9.

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