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 body has a gas channel inside. The cover plate is connected to the body and has a vent hole communicating with the gas channel. The cover plate also has a weak area on its surface. The depth of the weak area is less than the thickness of the cover plate. The vent valve can quickly break the cover plate to discharge high-temperature gas 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, battery packs often 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, the high-temperature gas inside the battery pack needs to be expelled even faster to prevent the battery pack from exploding. The vent valve cover is usually quite robust, and it may not break quickly in the event of thermal runaway, resulting in the high-temperature gas not being able to escape rapidly. 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, which can quickly break the cover of the vent valve to discharge high-temperature gas in the event of thermal runaway of the battery pack, thereby at least partially solving the above-mentioned technical problems.

[0004] In a first aspect, the present invention provides a vent valve, the vent valve comprising: a body having a gas channel inside the body; a cover plate connected to the body, the cover plate having a vent hole communicating with the gas channel, and a weak area disposed on the surface of the cover plate, the depth of the weak area being less than the thickness of the cover plate.

[0005] Through the above technical solution, namely the vent valve provided by this utility model, when the battery pack is working normally, a small amount of gas generated by the heat inside the battery pack can be discharged normally through the vent hole of the vent valve, thereby stabilizing the internal temperature of the battery pack. However, when the battery is working under high load conditions, if the internal temperature of the battery pack becomes too high and thermal runaway occurs, the expanding high-temperature gas will pass through the gas channel of the vent valve more and impact the main body and the cover plate. The depth of the weak area set on the surface of the cover plate is less than the thickness of the cover plate. Under the impact of high-temperature and high-pressure gas, the weak area can be broken by the high-temperature and high-pressure gas, or indirectly the cover plate will be destroyed as a whole through the broken weak area. After the cover plate is destroyed, it is no longer connected to the main body, thereby increasing the rate of gas exhaust from the gas channel inside the main body. This allows the high-temperature gas to be discharged from the battery pack as soon as possible in the event of battery thermal runaway, thereby reducing or preventing further damage to the battery pack by the high-temperature gas.

[0006] The beneficial effects of the other alternative solutions described above will be explained in the following detailed implementation. 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 cover plate provided in an exemplary embodiment of the present utility model;

[0010] Figure 3 This is a schematic diagram of the gas channel 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. Body; 2. Cover plate; 3. Ventilation hole; 4. Weak area; 5. Shell. Detailed Implementation

[0015] 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.

[0016] During operation, battery packs often 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, the high-temperature gas inside the battery pack needs to be expelled even faster to prevent the battery pack from exploding. The vent valve cover is usually quite robust, and it may not break quickly in the event of thermal runaway, resulting in the high-temperature gas not being able to escape rapidly.

[0017] 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 body 1 has a gas channel inside. The cover plate 2 is connected to the body 1 and has a vent hole 3 communicating with the gas channel. The cover plate 2 also has a weak area 4 on its surface. The depth of the weak area 4 is less than the thickness of the cover plate 2.

[0018] Through the above technical solution, namely the vent valve provided by this utility model, when the battery pack is working normally, a small amount of gas generated by the heat inside the battery pack can be discharged normally through the vent hole 3 of the vent valve, thereby stabilizing the internal temperature of the battery pack. However, when the battery is working under high load conditions, if the internal temperature of the battery pack becomes too high and thermal runaway occurs, the expanding high-temperature gas will pass through the gas channel of the vent valve more and impact the body 1 and the cover plate 2. The depth of the weak area 4 on the surface of the cover plate 2 is less than the thickness of the cover plate 2. Under the impact of high-temperature and high-pressure gas, the weak area 4 can be broken by the high-temperature and high-pressure gas, or indirectly the cover plate 2 can be completely destroyed through the broken weak area 4. After the cover plate 2 is destroyed, it is no longer connected to the body 1, thereby increasing the rate of gas exhaust from the gas channel inside the body 1. This allows the high-temperature gas to be discharged from the battery pack as soon as possible in the event of battery thermal runaway, thereby reducing or preventing further damage to the battery pack by the high-temperature gas.

[0019] It should be noted that in the above embodiments, this utility model reduces or prevents the cover plate 2 from failing to break quickly during battery thermal runaway, thereby increasing the venting capacity, by appropriately weakening the structural strength of the cover plate 2 itself. Figure 1 As shown, in Figure 1 In the example, the weak area 4 on the surface of the cover plate 2 is a groove structure recessed in the thickness direction of the cover plate 2, and the depth of the weak area 4 is also less than the overall thickness of the cover plate 2. When the battery pack experiences thermal runaway, the high-temperature gas impacts the cover plate 2 along the gas channel inside the body 1. The weak area 4 is more likely to be melted by the high temperature of the high-temperature gas, or broken by the excessive pressure of the high-temperature gas, thus destroying the weak area 4 of the cover plate 2. The high-temperature gas can be exhausted from the vent 3 and the destroyed weak area 4 at the same time. Alternatively, when the pressure of the high-temperature gas is higher, the destruction of the weak area 4 can further reduce the overall strength of the cover plate 2, and thus the entire cover plate 2 can be directly destroyed by the impact of the high-temperature gas. That is, the cover plate 2 can break on its own or detach from the body 1 as a whole. At this time, the exhaust volume of the vent valve is the largest, which can maximize the exhaust of the high-temperature gas through the vent valve.

[0020] Furthermore, combined Figures 1 to 3As can be seen from the above embodiments, the number of weak areas 4 arranged on the cover plate 2, the arrangement position of each of the multiple weak areas 4, and the shape of a single weak area 4 can be any suitable, as long as it can satisfy the requirement that the weak area 4 can break as soon as possible to increase the exhaust volume when the high-temperature gas impacts the cover plate. This embodiment does not limit this too much. Specifically, the layout of the weak area 4 will be illustrated with examples below, and will not be elaborated on here.

[0021] In some implementations, reference Figures 1 to 3 As shown, the ratio of the depth of the weak zone to the thickness of the cover plate is A, where A is less than or equal to 0.9 and greater than or equal to 0.1.

[0022] In this way, the depth of the weak area 4 and the overall thickness A of the cover plate 2 are limited to between 0.9 and 0.1. This ensures that the weak area 4 will not be damaged during normal venting, i.e., melted or broken, and that the weak area 4 itself will not be too thick and unable to break quickly in the event of thermal runaway of the battery pack.

[0023] In some implementations, reference Figures 1 to 3 As shown, the ratio of the projected area of ​​the weak zone 4 toward the end face of the cover plate 2 to the total area of ​​the end face of the cover plate 2 is B, where B is less than or equal to 0.9 and greater than 0.05.

[0024] Through the above method, the total area B of the weak area 4 in the cover plate 2 is limited to between 0.9 and 0.05. This satisfies the condition that the vent valve will not damage the weak area 4 during normal venting, i.e., it will not be melted or broken. It also ensures that the weak area 4 itself will not be too thick and unable to break quickly in the event of thermal runaway of the battery pack. In other words, it can be understood that the proportion of the area of ​​the weak area 4 can complement the depth of the weak area 4 in the above embodiment. That is, when the proportion of the area of ​​the weak area 4 is relatively reduced, the depth of the weak area 4 can be appropriately increased, and vice versa. It is only necessary to ensure that the weak area 4 is not damaged during normal venting and can break quickly in the event of thermal runaway of the battery pack.

[0025] In some implementations, reference Figures 1 to 5 As shown, weak zone 4 is constructed as a groove recessed into the surface of the cover plate.

[0026] By constructing the weak area 4 as a groove in the above manner, the processing difficulty of the cover plate 2 can be simplified. That is to say, when processing the cover plate 2, it is only necessary to use a grooving machine or other equipment that can dig out the groove to groove the surface of the cover plate 2, so that the weak area 4 can be easily processed. The processing is simple, efficient and fast.

[0027] It should be noted that the specific construction method of constructing the weak area 4 as a groove recessed into the surface of the cover plate 2 is exemplary. In the embodiment not shown in the figure, the materials used to manufacture the weak area 4 and the cover plate 2 can be different. For example, the cover plate 2 itself can be made of metal, while the weak area 4 can be formed of thermoplastic materials such as plastic. In this way, when thermal runaway occurs inside the battery pack, the weak area 4 made of plastic or other materials can melt more quickly due to the heat transfer of high temperature gas, or break more quickly due to the strong impact of gas, thereby increasing the exhaust volume.

[0028] In some implementations, reference Figures 1 to 5 As shown, there are multiple grooves, which are arranged at intervals on at least one side of the cover plate 2.

[0029] With the above arrangement, in the event of thermal runaway of the battery pack, the high-temperature gas can impact the multiple grooves, thereby melting or breaking at least some of the grooves more quickly. This increases the venting efficiency and volume of the high-temperature gas inside the battery pack. Furthermore, the multiple grooves can be arranged at intervals on one side of the cover plate 2 or at intervals on both sides of the cover plate 2. When arranged on one side of the cover plate 2, it is preferable to arrange them on the side of the cover plate 2 closer to the gas channel, that is, the side of the cover plate 2 facing the body 1. In this arrangement, the high-temperature gas during thermal runaway of the battery pack can directly contact the grooves, thereby destroying the grooves more quickly and increasing the venting volume of the vent valve. When the multiple grooves are arranged on opposite sides of the cover plate 2, the destruction rate of the grooves by the high-temperature gas can be further increased. That is, the grooves can be more easily destroyed under the impact of the high-temperature gas, thereby increasing the venting volume more quickly.

[0030] Furthermore, the cover material of the vent valve can be one or more of PBT and glass fiber, ABS, ABS and glass fiber, PC or PC, ABS and glass fiber. When high-temperature gas impacts the cover 2 and the grooves on its surface, the cover 2 made of the above materials can be more easily damaged, thereby increasing the exhaust efficiency of the vent valve. Since the above materials are relatively mature materials in related technologies, those skilled in the art are familiar with the properties of each of the above materials. Therefore, this embodiment will not elaborate further.

[0031] In some implementations, reference Figures 1 to 5 As shown, there can be multiple vent holes 3, which are arranged at intervals on the cover plate 2.

[0032] In the above manner, the exhaust efficiency can be increased by using multiple vent holes 3, and the normal exhaust can be met under normal battery pack operation. In combination with the above implementation method, when there are multiple vent holes 3, the number of weak areas 4 or the depth of weak areas 4, or the total area of ​​weak areas 4 on the cover plate 2 can also be adaptively reduced.

[0033] Furthermore, when there are multiple vent holes 3, the arrangement of the vent holes 3 and the grooves can be any suitable arrangement, for example, refer to Figures 1 to 3 Multiple grooves are arranged at intervals along the circumference of the vent holes 3 on the cover plate 2, and at least one groove is provided between any two adjacent vent holes 3.

[0034] With the above-described layout, multiple vent holes 3 can cooperate with multiple grooves in the layout, thereby improving the overall susceptibility of the cover plate 2 to damage during battery pack thermal runaway. Furthermore, the presence of at least one groove between two adjacent vent holes 3 can further weaken the structural strength of the cover plate 2. In the event of battery pack thermal runaway, the damage to the groove can trigger a chain reaction, leading to a more brittle fracture of the cover plate 2 and allowing the high-temperature gas inside the battery pack to be discharged through the vent valve more quickly.

[0035] It should be noted that the vent 3 may or may not be connected to the groove. Figure 1 and Figure 2 In the example, the vent 3 is arranged to be connected to the groove, which can break faster. The vent 3 can also be not connected to the groove, which can increase the overall structural strength of the cover plate 2. The specific layout can be selected according to the exhaust volume of the battery pack. This embodiment will not limit it too much.

[0036] In some implementations, reference Figures 1 to 3 As shown, the ratio of the total area of ​​the vent hole 3 to the cross-sectional area of ​​the cover plate 2 is C, where C is less than or equal to 0.5 and greater than or equal to 0.05.

[0037] By limiting the area ratio of the vent hole 3 on the cross-section of the cover plate 2, we can prevent the vent hole 3 from being too large and causing insufficient structural strength of the cover plate 2, and also prevent the vent hole 3 from being too small and causing poor air permeability. In other words, when C is greater than 0.5, the vent hole 3 accounts for too much of the cross-section of the cover plate 2, and the structural performance of the cover plate 2 itself will decrease. When C is less than 0.05, the vent hole 3 accounts for too little of the cross-section of the cover plate 2, and the air permeability of the vent valve itself will also decrease. Therefore, considering all factors, setting the ratio C between 0.05 and 0.5 is the most reasonable range.

[0038] 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.

[0039] A second aspect of this utility model provides a battery pack, as referenced. Figures 1 to 5 As shown, the battery pack includes a housing 5, battery cells disposed within the housing 5, and a vent valve mentioned in the above specific embodiment. The vent valve is disposed on the housing 5 of the battery pack, and the battery pack has all the beneficial effects of the above specific embodiment. In the event of thermal runaway of the battery pack, the high-temperature gas inside the battery pack can be quickly discharged through the vent valve. Furthermore, when there is an excessive amount of high-temperature gas, the high-temperature gas can also impact and damage the weak area 4 on the cover plate 2 of the vent valve, thereby damaging the weak area 4 or destroying the cover plate 2 as a whole, thereby increasing the exhaust volume.

[0040] In some embodiments, the number of vent valves may also be multiple and spaced apart in the housing 5 of the battery pack.

[0041] In the above manner, when thermal runaway occurs in the cells inside the battery pack, multiple vent valves can further improve the venting efficiency. Furthermore, this embodiment does not specify the exact number of vent valves; for example, the number of vent valves can be two, three, or more.

[0042] A third aspect of this utility model provides an electrical device including the battery pack mentioned in the above specific embodiments. The electrical device also has all the beneficial effects of the above embodiments. 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 smart devices; it can also be a flashlight, work light, or other lighting device; 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 further limitations on these aspects.

[0043] 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: Body (1), wherein a gas channel is provided inside the body (1); A cover plate (2) is connected to the body (1). The cover plate (2) is provided with a vent hole (3) communicating with the gas channel, and a weak area (4) is provided on the surface of the cover plate (2). The depth of the weak area (4) is less than the thickness of the cover plate (2).

2. The vent valve according to claim 1, characterized in that, The ratio of the depth of the weak area (4) to the thickness of the cover plate (2) is A, where A is less than or equal to 0.9 and greater than or equal to 0.

1.

3. The vent valve according to claim 1, characterized in that, The ratio of the area of ​​the weak area (4) projected toward the end face of the cover plate (2) to the total area of ​​the end face of the cover plate (2) is B, where B is less than or equal to 0.9 and greater than or equal to 0.

05.

4. The vent valve according to claim 1, characterized in that, The weak area (4) is constructed as a groove recessed into the surface of the cover plate (2).

5. The vent valve according to claim 4, characterized in that, The number of grooves is multiple, and the multiple grooves are arranged at intervals on at least one side of the cover plate (2).

6. The vent valve according to claim 5, characterized in that, The number of the vent holes (3) is multiple, and the multiple vent holes (3) are arranged at intervals on the cover plate (2).

7. The vent valve according to claim 6, characterized in that, Multiple grooves are arranged at intervals along the circumference of the vent holes (3) on the cover plate (2), and at least one groove is provided between any two adjacent vent holes (3).

8. The vent valve according to claim 1, characterized in that, The ratio of the total area of ​​the vent hole (3) to the cross-sectional area of ​​the cover plate (2) is C, where C is less than or equal to 0.5 and greater than or equal to 0.

05.

9. 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 1-8, the vent valve being disposed on the housing (5).

10. The battery pack according to claim 9, characterized in that, The number of vent valves is multiple and they are spaced apart on the housing (5) of the battery pack.

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

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