Anti-rebound pressure relief structure and battery module

Abstract

The utility model belongs to the technical field of batteries, and discloses an anti-springback pressure relief structure and a battery module, the anti-springback pressure relief structure is used for being installed at a pressure relief opening of a box body of the battery module, the anti-springback pressure relief structure comprises a base and a valve body, the base abuts against the side wall of the box body, the valve body is connected to the base, the valve body is communicated with the pressure relief opening, and the valve body is connected with the base. A valve cavity is defined by the valve body, an openable pressure relief end is formed at the end, away from the base, of the valve cavity, and the cross section area of the pressure relief end is smaller than that of the communicating position of the valve body and the pressure relief opening. When airflow with preset pressure enters the valve cavity, the pressure relief end can be opened under the action of the airflow so as to exhaust the airflow. According to the anti-springback pressure relief structure, the probability that springback high-temperature flue gas flows back through other subsequent pressure relief ports can be reduced while high temperature generated by thermal runaway of the battery cell is ensured to be stably discharged along the anti-springback pressure relief structure, the thermal runaway degree of the battery module is favorably inhibited, and the use safety of the battery module is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to an anti-rebound pressure relief structure and a battery module. Background Technology

[0002] The battery module is a key intermediate component in a battery pack, typically consisting of a housing structure and multiple battery cells (individual cells) housed within it. During battery module operation, if a cell experiences thermal runaway, it first releases pressure through a valve at a structurally weak point. To ensure the rapid discharge of the high-temperature fumes generated by thermal runaway, pressure relief vents are usually installed on the battery module's housing structure corresponding to the cell's pressure relief location. These pressure relief vents are usually arranged in a row. When a cell releases pressure, the high-temperature fumes are ejected from one vent. When these fumes come into contact with other structural components, they rebound, flowing back through other vents and accelerating thermal runaway in subsequent cells, potentially leading to short-circuit runaway. Utility Model Content

[0003] The first objective of this invention is to provide an anti-rebound pressure relief structure. This structure ensures the stable discharge of high-temperature fumes generated by thermal runaway of the battery cell. When high-temperature fumes discharged from other pressure relief ports of the battery module rebound, the pressure relief end of the anti-rebound pressure relief structure remains closed because there is no airflow entering the valve chamber or the airflow pressure entering the valve chamber is low. This prevents the rebounded high-temperature fumes from flowing back through the pressure relief end, thereby reducing the probability of high-temperature fumes flowing back. This helps to suppress the degree of thermal runaway of the battery module and improves the safety of the battery module.

[0004] The second objective of this utility model is to provide a battery module that ensures the stable discharge of high temperatures generated by thermal runaway of the battery cells and reduces the likelihood of high-temperature flue gas discharged from other pressure relief ports flowing back through them. This helps to suppress the degree of thermal runaway of the battery module and improve the safety of its use.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] This utility model discloses an anti-rebound pressure relief structure, which is used to install at the pressure relief port of the battery module housing. The anti-rebound pressure relief structure includes: a base, which abuts against the side wall of the housing; a valve body, which is connected to the base and communicates with the pressure relief port, the valve body defining a valve cavity, and the end of the valve cavity away from the base forming an openable pressure relief end, the cross-sectional area of ​​the pressure relief end being smaller than the cross-sectional area of ​​the valve body communicating with the pressure relief port; wherein: when an airflow with a preset pressure enters the valve cavity, the pressure relief end can open under the action of the airflow to discharge the airflow.

[0007] In some embodiments, at least a portion of the valve cavity has a gradually decreasing cross-sectional area in the direction away from the base.

[0008] In some specific embodiments, the valve body includes a straight section, a transition section and a tapering section connected in sequence. The straight section is connected to the base, the pressure relief end is formed at the small end of the tapering section, and the transition section is connected between the large end of the tapering section and the straight section.

[0009] In some specific embodiments, the outer surface of the transition section is an arc-shaped surface.

[0010] In some specific embodiments, the straight section and the transition section are of equal wall thickness.

[0011] In some embodiments, the adhesive layer is bonded to the inner wall of the housing, and the valve body passes through the pressure relief port; or, the adhesive layer is bonded to the outer wall of the housing, and the valve body is arranged around the pressure relief port.

[0012] In some embodiments, the base and the valve body are integrally formed, or the base and the valve body are bonded together.

[0013] In some embodiments, the valve body has a slot extending along its contour direction, and the base is sleeved on the valve body and snapped into the slot; or, the valve body and the base are connected by a clamp.

[0014] This utility model discloses a battery module, including a housing and the aforementioned anti-rebound pressure relief structure. The housing is provided with a pressure relief port, and the anti-rebound pressure relief structure is installed at the pressure relief port of the housing.

[0015] In some embodiments, a cavity is provided inside the side wall of the housing, the cavity has an exhaust port communicating with the external environment, and the pressure relief port is located on the side wall of the housing and communicates with the cavity.

[0016] The beneficial effects of the anti-rebound pressure relief structure of this utility model are as follows: In actual operation, when a battery cell experiences thermal runaway, the high-temperature flue gas generated will enter the valve cavity from the pressure relief port adjacent to or directly opposite the thermal runaway point. The pressure generated by the high-temperature flue gas directly entering the valve cavity is relatively large, exceeding the preset pressure, causing the valve cavity to open and the pressure relief end to expand, allowing the high-temperature flue gas to be discharged from the opened pressure relief end. When a battery cell experiences thermal runaway, and the generated high-temperature flue gas is discharged from other pressure relief ports of the battery module and rebounds, the anti-rebound pressure relief structure is not impacted by the high-temperature flue gas or is only minimally impacted. The pressure relief end remains in its initial unopened state. Even if high-temperature flue gas rebounds, it will disperse to other locations along the outer surface of the valve body, preventing the rebounded high-temperature flue gas from flowing back through the pressure relief end. This reduces the probability of high-temperature flue gas backflow, which helps to suppress the degree of thermal runaway of the battery module and improves the safety of the battery module.

[0017] The beneficial effects of this utility model's battery module are as follows: Due to the aforementioned anti-rebound pressure relief structure, on the one hand, it can ensure the stable discharge of high temperatures generated by thermal runaway of the battery cell; on the other hand, when a large amount of high-temperature flue gas is discharged from other pressure relief ports and rebounds, it can reduce the probability that the rebounded high-temperature flue gas will flow back through the pressure relief port where the anti-rebound pressure relief structure is located, which is beneficial to suppressing the degree of thermal runaway of the battery module and improving the safety of the battery module in use.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the anti-rebound pressure relief structure according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the cooperation structure between the anti-rebound pressure relief structure and the battery module in an embodiment of this utility model;

[0021] Figure 3 This is a schematic diagram of the battery module housing according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the casing of another battery module according to an embodiment of the present invention.

[0023] Figure label:

[0024] 100. Anti-rebound pressure relief structure; 110. Base; 120. Valve body; 121. Straight section; 122. Transition section; 123. Gradual reduction section; 1231. Pressure relief end;

[0025] 200, housing; 210, pressure relief port; 220, cavity. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure. In the description of the present invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0027] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0028] like Figure 1 As shown, this utility model discloses an anti-rebound pressure relief structure 100. The anti-rebound pressure relief structure 100 is used to install at the pressure relief port 210 of the battery module housing 200. The anti-rebound pressure relief structure 100 includes a base 110 and a valve body 120. The base 110 abuts against the side wall of the housing 200. The valve body 120 is connected to the base 110 and communicates with the pressure relief port 210. The valve body 120 defines a valve cavity. The end of the valve cavity away from the base 110 forms an openable pressure relief end 1231. The cross-sectional area of ​​the pressure relief end 1231 is smaller than the cross-sectional area of ​​the valve body 120 communicating with the pressure relief port 210. When airflow with a preset pressure enters the valve cavity, the pressure relief end 1231 can open under the action of the airflow to discharge the airflow.

[0029] It is understood that, in actual operation, the anti-rebound pressure relief structure 100 of this embodiment, when the high-temperature flue gas generated after the thermal runaway of the battery cell occurs, will be discharged from the pressure relief port 210 adjacent to or directly opposite the thermal runaway point. When the anti-rebound pressure relief structure 100 is provided at the pressure relief port 210, the discharged high-temperature flue gas will enter the valve cavity. When the pressure generated by the high-temperature flue gas entering the valve cavity is large and exceeds the preset pressure, the pressure relief end 1231 opens, and the high-temperature flue gas can be discharged from the pressure relief end 1231. However, when there is rebounding high-temperature flue gas outside the valve body 120, for example, when the high-temperature flue gas generated after the thermal runaway of the battery cell is mainly discharged from another pressure relief port 210 and rebounds, the anti-rebound pressure relief structure 100 is not impacted by the high-temperature flue gas. Alternatively, if the impact of high-temperature flue gas is relatively small (i.e., the pressure on the pressure relief end 1231 of the anti-rebound pressure relief structure 100 is less than the preset pressure), the pressure relief end 1231 remains closed. Since the cross-sectional area of ​​the pressure relief end 1231 is smaller than the cross-sectional area at the connection between the valve body 120 and the pressure relief port 210, even if high-temperature flue gas rebounds, it will be dispersed to other locations under the guidance of the outer surface of the valve body 120 and will not enter the space where the battery cell is located from the closed pressure relief end 1231. Thus, while ensuring that the high temperature generated by the thermal runaway of the battery cell is stably discharged, it can prevent the rebounding high-temperature flue gas from flowing back through other pressure relief ports 210, which is beneficial to suppressing the degree of thermal runaway of the battery module and improving the safety of the battery module.

[0030] Specifically, the following description uses two adjacent pressure relief ports 210 and the anti-rebound pressure relief structure 100 as examples. Figure 2 There are two pressure relief ports 210, designated as the first pressure relief port and the second pressure relief port, respectively. Each of the first and second pressure relief ports is equipped with an anti-rebound pressure relief structure 100. The high-temperature flue gas generated after thermal runaway of the battery cell is mainly discharged from the first pressure relief port directly opposite the thermal runaway point. The anti-rebound pressure relief structure 100 corresponding to the first pressure relief port (corresponding to...) Figure 2 The anti-rebound pressure relief structure 100 (indicated by arrow c) opens at the pressure relief end 1231 under the significant impact of the high-temperature flue gas, allowing the high-temperature flue gas to exit from the pressure relief end 1231. Meanwhile, at the anti-rebound pressure relief structure 100 at the second pressure relief port adjacent to the first pressure relief port, less high-temperature flue gas exits from the second pressure relief port, thus allowing the gas to enter the anti-rebound pressure relief structure 100 corresponding to the second pressure relief port (corresponding to...). Figure 2 The airflow pressure in the valve chamber of the anti-rebound pressure relief structure 100 (indicated by the middle arrow b, where the pressure relief end 1231 is not open) is relatively low. Since the pressure relief end 1231 is not open, the high-temperature flue gas discharged from the pressure relief end 1231 of the anti-rebound pressure relief structure 100 at the first pressure relief port rebounds. Under the guidance of the outer surface of the valve body 120 of the anti-rebound pressure relief structure 100 at the second pressure relief port, the airflow is dispersed to other positions and cannot flow back through the anti-rebound pressure relief structure 100 at the second pressure relief port.

[0031] It should be noted that the cross-sectional area mentioned above refers to the area where the pressure relief end 1231 and the valve body 120 connect with the pressure relief port 210 in the direction of airflow ( Figure 2 The plane perpendicular to the direction a) Figure 2 The cross-sectional area on the vertical plane (in the middle).

[0032] Optionally, the preset pressure is 5 kPa. The peak pressure of the battery cell's depressurization is generally around 20 kPa. With a preset pressure of 5 kPa, the high-temperature flue gas can quickly open the depressurization end 1231 during the battery cell depressurization process, ensuring that the high-temperature flue gas is discharged rapidly. Of course, in other embodiments of this utility model, the preset pressure can be determined based on parameters such as the type of battery cell and the material of the valve body 120.

[0033] refer to Figure 1 As shown, in the direction away from the base 110, the cross-sectional area of ​​at least a portion of the valve cavity gradually decreases. It is understandable that with the cross-sectional area of ​​a portion of the valve cavity gradually decreasing, the airflow velocity increases upon entering the valve cavity, and the pressure generated by the airflow also increases, thus allowing the pressure relief end 1231 to open smoothly under the impact of the airflow. Furthermore, with the cross-sectional area of ​​a portion of the valve cavity gradually decreasing, a portion of the outer wall of the valve body 120 is formed as a slope. This slope effectively guides the rebounding high-temperature flue gas, causing it to diffuse towards the outer side of the outer wall of the valve body 120, thus significantly reducing the probability of high-temperature flue gas backflow.

[0034] Optionally, the valve body 120 includes a straight section 121, a transition section 122, and a tapered section 123 connected in sequence. The straight section 121 is connected to the base 110, and the pressure relief end 1231 is formed at the small end of the tapered section 123. The transition section 122 connects the large end of the tapered section 123 and the straight section 121. It is understood that the straight section 121 facilitates the connection between the valve body 120 and the base 110 and enhances the connection strength. The transition section 122 enables the connection between the straight section 121 (without changing dimensions) and the tapered section 123 (with gradually decreasing dimensions), facilitating the manufacturing of the valve body 120 and reducing the internal stress of the valve body 120. The tapered section 123 can open stably when impacted by high-temperature flue gas, ensuring that the high-temperature flue gas can be stably discharged from the pressure relief end 1231. On the other hand, it can play a good guiding role for the rebounding high-temperature flue gas, reducing the probability that the rebounding high-temperature flue gas will flow back through other pressure relief ports 210.

[0035] Optionally, the straight section 121 and the transition section 122 have equal wall thickness. This facilitates the manufacturing of the valve body 120 and also allows the high-temperature flue gas to flow towards the pressure relief end 1231 under the guidance of the straight section 121 and the transition section 122.

[0036] Optionally, the outer surface of the transition section 122 is arc-shaped. This facilitates the manufacturing of the valve body 120, and the arc shape helps guide the airflow when the rebounding high-temperature flue gas passes through the outer surface of the transition section 122, allowing the high-temperature flue gas to dissipate to other locations and further reducing the probability of high-temperature flue gas backflow. Optionally, an adhesive layer is provided on the base 110, and the adhesive layer is bonded to the inner wall of the battery module. This bonding method allows for easy fixation of the anti-rebound pressure relief structure 100 of this embodiment to the housing 200.

[0037] Optionally, the base 110 and the valve body 120 are integrally molded parts. Since the base 110 and the valve body 120 are integrally molded parts, the anti-rebound pressure relief structure 100 of this embodiment can be directly manufactured by die casting or injection molding, which is convenient for manufacturing.

[0038] Optionally, the base 110 and valve body 120 are bonded together. Understandably, compared to a one-piece molded structure, separating the base 110 and valve body 120 into two bonded parts allows for the use of different materials in the actual manufacturing process. The base 110 can be injection molded from a high-temperature resistant material (such as SCM material, a composite material composed of epoxy resin and polyimide) to reduce the risk of heat melting under the impact of high-temperature flue gas. The valve body 120 can be made from high-temperature resistant mica paper, facilitating its molding and opening under the impact of high-temperature flue gas, thus better meeting usage requirements. Furthermore, it should be noted that the valve body 120 can be made from high-temperature resistant, fold-resistant materials, or other materials such as fiberglass paper.

[0039] Optionally, the tapered section 123 includes two stop walls and two connecting walls. The stop walls and connecting walls are arranged adjacently and connected in sequence to form a cavity structure with an open large end (connected to the transition section 122) and a pressure relief end 1231. The two stop walls stop at the pressure relief end 1231, and the two connecting walls have a folded structure. The folded structure is used to: when the airflow with a preset pressure enters the valve cavity, the folded structure extends so that the size of the connecting wall at the pressure relief end 1231 increases, so that the two stop walls can move in a direction away from each other, thereby realizing the opening of the pressure relief end 1231.

[0040] It should be noted that in the actual production process, mica paper or fiberglass paper (or other materials) is pre-pressed to form creases, placed in a mold, and pre-pressed to form valve body 120.

[0041] Optionally, the base 110 needs to withstand a high temperature of 400℃. Of course, the material of the base 110 can also be selected according to actual needs, as long as it is ensured that the base 110 will not melt or deform under the impact of high-temperature flue gas and will not fall off the side wall of the box 200.

[0042] Optionally, the valve body 120 has a slot extending along its contour, and the base 110 is fitted onto the valve body 120 and snapped into the slot. Compared to adhesive bonding, direct snap-fit ​​connection between the valve body 120 and the base 110 is more convenient for assembly. Of course, in other embodiments of this utility model, the base 110 and the valve body 120 can also be connected by clamps or welding or other methods, and are not limited to the above limitations.

[0043] Optionally, the valve body 120 and the base 110 are connected by clamps. Specifically, the valve body 120 is provided with two clamp slots. After the base 110 is fitted onto the valve body 120, clamps are installed in the two clamp slots. The two clamps abut against two opposite surfaces of the base 110 to fix the base 110 relative to the valve body 120.

[0044] This utility model also discloses a battery module, including a housing 200 and the aforementioned anti-rebound pressure relief structure 100. The housing 200 is provided with a pressure relief port 210, and the anti-rebound pressure relief structure 100 is installed at the pressure relief port 210 of the housing 200. Due to the aforementioned anti-rebound pressure relief structure 100, while ensuring that the high temperature generated by the thermal runaway of the battery cell is stably discharged along it, it can reduce the backflow of high-temperature flue gas from the rebound through other pressure relief ports 210, which is beneficial to suppressing the degree of thermal runaway of the battery module and improving the safety of the battery module in use.

[0045] Optional, see reference Figure 2 and Figure 3As shown, a cavity 220 is formed inside the side wall of the housing 200. The cavity 220 has an exhaust port that communicates with the external environment. Multiple pressure relief ports 210 are located on the side wall of the housing 200 and communicate with the cavity 220. Each pressure relief port 210 is equipped with an anti-rebound pressure relief structure 100. In the prior art, when high-temperature flue gas impacts the side wall of the cavity 220, it rebounds and flows back through other pressure relief ports 210. This can cause thermal runaway to spread, seriously affecting the operational reliability and safety of the battery module. In this embodiment, since the anti-rebound pressure relief structure 100 described above is provided in the cavity 220, the high-temperature flue gas generated after the battery cell experiences thermal runaway will enter the valve cavity from the pressure relief port 210, causing the valve cavity to open and the pressure relief end 1231 to open. The high-temperature flue gas can be discharged from the pressure relief end 1231 into the cavity 220, and then discharged from the exhaust port of the cavity 220 into the housing 200. After the high-temperature flue gas bounces off the side wall of the cavity 220, since the other anti-rebound pressure relief structures 100 are not impacted by the high-temperature flue gas or are only slightly impacted, the pressure relief end 1231 remains closed, thereby reducing the probability of high-temperature flue gas flowing back from the other anti-rebound pressure relief structures 100.

[0046] Optional, see reference Figure 4 As shown, the side wall of the housing 200 is provided with multiple pressure relief ports 210. In the prior art, after the high-temperature flue gas is discharged from the pressure relief port 210, it impacts the external structural components of the battery module, such as the support structure and mounting structure of the battery module, and may flow back into the battery module from other pressure relief ports 210. This can cause thermal runaway to spread, seriously affecting the operational reliability and safety of the battery module. In this embodiment, due to the provision of the anti-rebound pressure relief structure 100, the probability of high-temperature flue gas flowing back into the battery module from other anti-rebound pressure relief structures 100 can be reduced.

[0047] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A rebound-resistant pressure relief structure, characterized in that, The anti-rebound pressure relief structure is installed at the pressure relief port (210) of the battery module housing (200), and the anti-rebound pressure relief structure includes: A base (110) abuts against the side wall of the housing (200); A valve body (120) is connected to the base (110) and communicates with the pressure relief port (210). The valve body (120) defines a valve cavity, and one end of the valve cavity away from the base (110) forms an openable pressure relief end (1231). The cross-sectional area of ​​the pressure relief end (1231) is smaller than the cross-sectional area of ​​the valve body (120) communicating with the pressure relief port (210). When a gas flow with a preset pressure enters the valve chamber, the pressure relief end (1231) can open under the action of the gas flow to discharge the gas flow.

2. The anti-rebound pressure relief structure according to claim 1, characterized in that, In the direction away from the base (110), the cross-sectional area of ​​at least a portion of the valve cavity gradually decreases.

3. The anti-rebound pressure relief structure according to claim 2, characterized in that, The valve body (120) includes a straight section (121), a transition section (122) and a tapering section (123) connected in sequence. The straight section (121) is connected to the base (110). The pressure relief end (1231) is formed at the small end of the tapering section (123). The transition section (122) is connected between the large end of the tapering section (123) and the straight section (121).

4. The anti-rebound pressure relief structure according to claim 3, characterized in that, The outer surface of the transition section (122) is an arc-shaped surface.

5. The anti-rebound pressure relief structure according to claim 3, characterized in that, The straight section (121) and the transition section (122) are of equal wall thickness.

6. The anti-rebound pressure relief structure according to claim 1, characterized in that, An adhesive layer is provided on the base (110), and the adhesive layer is bonded to the inner wall of the housing (200). The valve body (120) passes through the pressure relief port (210); or, The adhesive layer is bonded to the outer wall of the housing (200), and the valve body (120) is arranged around the pressure relief port (210).

7. The anti-rebound pressure relief structure according to any one of claims 1-6, characterized in that, The base (110) and the valve body (120) are integrally formed, or, The base (110) and the valve body (120) are bonded together.

8. The anti-rebound pressure relief structure according to any one of claims 1-6, characterized in that, The valve body (120) has a slot extending along its contour direction, and the base (110) is sleeved on the valve body (120) and snapped into the slot; or, the valve body (120) and the base (110) are connected by a clamp.

9. A battery module, characterized in that, The device includes a housing (200), an anti-rebound pressure relief structure as described in any one of claims 1-8, and a battery cell stored inside the housing (200). The housing (200) is provided with a pressure relief port (210), and the anti-rebound pressure relief structure is installed at the pressure relief port (210) of the housing (200).

10. The battery module according to claim 9, characterized in that, The side wall of the housing (200) has a cavity (220) inside, the cavity (220) has an exhaust port that communicates with the external environment, and the cavity (220) is connected to the space inside the housing (200) where the battery cells are stored through the pressure relief port (210) provided on the side wall of the housing (200).

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