Cover plate assembly and battery cell

Abstract

The application provides a cover plate assembly and a battery cell. The cover plate assembly comprises a cover plate body, an explosion-proof valve, a support frame and a support column. The cover plate body is provided with an explosion-proof hole. The explosion-proof valve is arranged in the explosion-proof hole. The support frame is located on the side of the explosion-proof valve close to the pole group. The support column extends along the thickness direction of the cover plate body, and the two ends of the support column are fixedly connected with the cover plate body and the support frame respectively. When the lower plastic melts due to thermal runaway of the battery cell, the support frame can abut against the pole group, and the support frame and the cover plate body have an exhaust passage communicating with the explosion-proof hole. In this way, a stable exhaust passage is formed between the cover plate body and the support frame. When the lower plastic melts due to thermal runaway of the battery cell, the support frame will not melt due to high temperature, and abuts against and supports between the cover plate body and the pole group, ensuring smooth exhaust passage, preventing the pole group from blocking the explosion-proof valve under the impact of airflow, and solving the problem that the pole group blocks the explosion-proof valve when the battery cell has thermal runaway in the prior art.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a cover plate assembly and a battery cell. Background Technology

[0002] In the battery cell structure, the explosion-proof valve plays an important role in ensuring the safety of the battery cell. When the battery cell experiences thermal runaway, it will produce a large amount of gas, which will cause excessive internal pressure. At this time, the explosion-proof valve is opened to release the internal gas and prevent the battery cell from side spraying and exploding.

[0003] Currently, some battery cell models have the explosion-proof valve designed on the cover plate. After overcharging and thermal runaway, the internal temperature of the battery cell will rise rapidly. The lower plastic between the electrode group and the cover plate will begin to melt when the temperature exceeds 160°C. The lower plastic loses its function of isolating the electrode group. During rapid pressure relief, the electrode group is easily impacted by the airflow and shifted to the pressure relief end, blocking the explosion-proof valve. This poses a risk of shell tearing or even fire. Utility Model Content

[0004] In view of this, this application provides a cover plate assembly and a battery cell to solve the problem of electrode blockage of the explosion-proof valve when the battery cell experiences thermal runaway in the prior art.

[0005] To achieve the above objectives, this application provides the following technical solution: A cover plate assembly, comprising: The cover plate body has explosion-proof holes; An explosion-proof valve is installed in the explosion-proof hole; The support frame is located on the side of the explosion-proof valve closest to the electrode assembly; The support column extends along the thickness direction of the cover plate body, and both ends of the support column are fixedly connected to the cover plate body and the support frame, respectively. When thermal runaway of the battery cell causes the lower plastic to melt, the support frame can abut against the electrode assembly, and the support frame and the cover plate body have an exhaust channel communicating with the explosion-proof hole.

[0006] Optionally, the support column is formed on the side of the cover plate body facing the support frame, and the side of the cover plate body facing away from the support frame is provided with a groove that is directly opposite the position of the support column; the support column is welded to the support frame.

[0007] Optionally, on a plane perpendicular to the thickness direction of the cover plate body, the orthographic projection edge of the groove is located within the orthographic projection edge of the support column.

[0008] Optionally, the support frame is inserted into the cover plate body along the thickness direction of the cover plate body.

[0009] Optionally, the support frame includes: Motherboard body; The plug-in portion is disposed on the side of the main board facing the cover plate body and protrudes relative to the main board body; The cover plate body is provided with a positioning slot that engages with the insertion part.

[0010] Optionally, the motherboard body is rectangular, and the plug-in portion is L-shaped and located at the corner of the motherboard body.

[0011] Optionally, along the thickness direction of the cover plate body, the thickness of the main body is D, where 0.5mm≤D≤1mm.

[0012] Optionally, along the thickness direction of the cover plate body, the sum of the height at which the plug protrudes relative to the main board body and the thickness of the main board body is H, where H ≤ 2.5 mm.

[0013] Optionally, the exhaust channel includes an opening formed between the edge of the main body and the cover body, the effective flow area of ​​the opening is S1, the opening area of ​​the explosion-proof valve is S2, and S1 / S2≥1.2.

[0014] A battery cell comprising the cover assembly described in any of the preceding claims.

[0015] The cover plate assembly provided in this application includes a cover plate body, an explosion-proof valve, a support frame, and a support column. The cover plate body has an explosion-proof hole. The explosion-proof valve is disposed in the explosion-proof hole. The support frame is located on the side of the explosion-proof valve near the electrode assembly. The support column extends along the thickness direction of the cover plate body, and both ends of the support column are fixedly connected to the cover plate body and the support frame, respectively. When the lower plastic melts due to thermal runaway of the battery cell, the support frame can abut against the electrode assembly, and there is an exhaust channel between the support frame and the cover plate body that communicates with the explosion-proof hole. This design adds a support frame inside the explosion-proof valve. The support frame is fixedly connected to the cover plate body, and through the spatial support of the support column, a stable exhaust channel is formed between the cover plate body and the support frame. Since the support frame is located between the cover plate body and the lower plastic, when the lower plastic melts due to thermal runaway of the battery cell, the support frame will not melt due to high temperature. It also abuts and supports between the cover plate body and the electrode assembly, ensuring that the exhaust channel is unobstructed and preventing the electrode assembly from blocking the explosion-proof valve under the impact of airflow. This solves the problem of electrode assembly blocking the explosion-proof valve when the battery cell experiences thermal runaway in the existing technology, alleviates the adverse consequences of battery cell thermal runaway, and thus increases battery safety performance. Attached Figure Description

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

[0017] Figure 1 This is an exploded view of the cover plate assembly provided in an embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the structure of the cover plate body provided in an embodiment of this application.

[0019] Figure 3 This is a side view of the cover plate assembly provided in an embodiment of this application.

[0020] Figure 4 This is a schematic diagram of the support frame provided in an embodiment of this application.

[0021] Figure 5 This is a dimensional diagram of the support frame provided in an embodiment of this application.

[0022] exist Figures 1-5 middle: 1. Cover plate body; 2. Explosion-proof valve; 3. Support frame; 4. Support column; 5. Opening; 6. Explosion-proof valve patch; 101. Explosion-proof hole; 102. Groove; 103. Positioning slot; 31. Mainboard body; 32. Connector. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] like Figures 1-5As shown, this application embodiment provides a cover plate assembly, including a cover plate body 1, an explosion-proof valve 2, a support frame 3, and a support column 4. The cover plate body 1 has an explosion-proof hole 101; the explosion-proof valve 2 is disposed in the explosion-proof hole 101; the support frame 3 is located on the side of the explosion-proof valve 2 near the electrode group; the support column 4 extends along the thickness direction of the cover plate body 1, and both ends of the support column 4 are fixedly connected to the cover plate body 1 and the support frame 3 respectively. The support column 4 has a plurality of columns distributed around the explosion-proof hole 101; wherein, when the lower plastic melts due to thermal runaway of the battery cell, the support frame 3 can abut against the electrode group, and there is an exhaust channel between the support frame 3 and the cover plate body 1 that communicates with the explosion-proof hole 101.

[0025] With this configuration, a support frame 3 is added inside the explosion-proof valve 2. The support frame 3 is fixedly connected to the cover plate body 1, and through the spatial support of the support column 4, a stable exhaust channel is formed between the cover plate body 1 and the support frame 3. Since the support frame 3 is located between the cover plate body 1 and the lower plastic, when the lower plastic melts due to thermal runaway of the battery cell, the support frame 3 will not melt due to high temperature. It also abuts and supports between the cover plate body 1 and the electrode assembly, ensuring that the exhaust channel is unobstructed and preventing the electrode assembly from blocking the explosion-proof valve 2 under the impact of airflow. This solves the problem of electrode assembly blocking the explosion-proof valve 2 when the battery cell experiences thermal runaway in the prior art, alleviates the adverse consequences of battery cell thermal runaway, and thus increases battery safety performance.

[0026] Those skilled in the art know that the lower plastic is placed between the cover plate body 1 and the electrode assembly; the lower plastic is not shown in the figure.

[0027] The thickness direction of the cover plate body is in Figure 1 The first direction is shown in the middle.

[0028] It should be noted that the cover plate body 1 can also be called the cover plate body 1. The material of the support frame 3 and the support column 4 can be set to be the same as that of the cover plate body 1, such as 3-series aluminum. This can ensure that the melting point of the support frame 3 and the support column 4 is higher than that of the lower plastic.

[0029] Regarding how the support column 4 is specifically fixed between the cover plate body 1 and the support frame 3, in some optional embodiments, the support column 4 is integrally formed on the side of the cover plate body 1 facing the support frame 3, and the support column 4 is welded to the support frame 3.

[0030] Furthermore, in some preferred embodiments, the side of the cover plate body 1 facing away from the support frame 3 is provided with a groove 102 that is directly opposite the position of the support column 4.

[0031] With this design, the groove 102 on the cover plate body 1 results in a localized thinning of the cover plate body 1, which facilitates through welding of the cover plate body 1 and the support frame 3 at this location. This solution is highly feasible and enhances the reliability of the welding.

[0032] In some preferred embodiments, on a plane perpendicular to the thickness direction of the cover plate body 1, the orthographic projection edge of the groove 102 is located within the orthographic projection edge of the support column 4.

[0033] This configuration improves the feasibility and reliability of through-welding by creating the groove 102 on the cover plate body 1. However, considering that the groove 102 can only be formed by partial material reduction of the cover plate body 1, in order to prevent excessive loss of structural strength at this location, i.e., to reduce the degree of structural strength loss, the distribution area of ​​the groove 102 is controlled within the edge of the support column 4. In this way, when the battery cell experiences thermal runaway and the cover plate body 1 is impacted by airflow, the support column 4 will generate shear force on the cover plate body 1. Through experiments and verification, controlling the distribution area of ​​the groove 102 within the edge of the support column 4 can weaken the impact of shear force on the cover plate body 1 and maintain the structural reliability of the cover plate body 1.

[0034] Of course, in addition to the above methods, it is also feasible to integrally form the support column 4 on the support frame 3 and weld the support column 4 to the cover plate body 1.

[0035] In some other preferred embodiments, the support frame 3 is inserted into the cover plate body 1 along the thickness direction of the cover plate body 1. This arrangement positions the support frame 3 on the cover plate body 1 before welding it to the support column 4, preventing the support frame 3 from being misaligned relative to the cover plate body 1. Furthermore, if the support frame 3 is subjected to excessive force during the venting process, the positioning and insertion between the support frame 3 and the cover plate body 1 can prevent excessive stress and failure at the weld between the support frame 3 and the support column 4, thereby avoiding displacement of the support frame 3 due to the influence of the electrode assembly.

[0036] In some specific embodiments, the support frame 3 includes a main board body 31 and a plug-in part 32; the main board body 31 is a solid plate parallel to the cover plate body 1; the plug-in part 32 is integrally formed on the side of the main board body 31 facing the cover plate body 1 and protrudes relative to the main board body 31; wherein, the cover plate body 1 is provided with a positioning slot 103 that engages with the plug-in part 32, and the positioning slot 103 is a partial material removal on the surface of the cover plate body 1.

[0037] It should be noted that when the explosion-proof valve 2 is oblong, the main body 31 can be rectangular or rounded; when the explosion-proof valve 2 is circular, the main body 31 can be circular.

[0038] Furthermore, in some optional embodiments, the motherboard body 31 is rectangular, and the plug-in portion 32 is L-shaped and located at the four corners of the motherboard body 31. This L-shaped design of the plug-in portion 32 not only improves the structural stability of the plug-in portion 32, but also reduces the amount of material removed from the cover plate body due to the positioning slot 103, thus ensuring the structural strength of the cover plate body 1.

[0039] Of course, it is also feasible to design the shape of the plug part 32 as having a circular or rectangular cross-section.

[0040] In addition, when the main body plate of the support frame 3 is designed to be rectangular, there are four support columns 4. The support columns 4 are welded to the main body plate of the support frame 3 near the middle position of the edge.

[0041] In some preferred embodiments, the thickness of the main body 31 of the support frame 3 is D along the thickness direction of the cover plate body 1, where 0.5mm ≤ D ≤ 1mm. Undoubtedly, the thickness direction of the main body 31 is consistent with the thickness direction of the cover plate body 1.

[0042] With this setup, after testing and verification, if the thickness of the main body 31 of the support frame 3 is greater than 1mm, the excessive thickness is not conducive to the penetration welding process and may easily lead to welding defects; if the thickness of the main body 31 of the support frame 3 is less than 0.5mm, the structural strength of the support frame 3 is insufficient, and there is a risk that the support frame 3 will fail to resist the failure of the support electrode assembly when thermal runaway of the battery cell occurs; when the thickness of the main body 31 of the support frame 3 meets the above range, it can ensure the normal progress of penetration welding, and the structural strength of the support frame 3 is sufficient to support the electrode assembly when thermal runaway occurs.

[0043] In some other preferred embodiments, along the thickness direction of the cover plate body 1, the sum of the height of the protrusion of the plug portion 32 relative to the main board body 31 and the thickness of the main board body 31 is H, where H≤2.5mm.

[0044] With this setup, since the support frame 3 is also limited by the space of the lower plastic, after testing and verification, when the total dimension H of the support frame 3 in the thickness direction does not exceed 2.5mm, interference with the lower plastic can be effectively avoided.

[0045] In some other preferred embodiments, the exhaust channel includes an opening 5 formed between the edge of the main body 31 and the cover body 1, the effective flow area of ​​the opening 5 is S1, and the opening area of ​​the explosion-proof valve 2 is S2, which is the effective flow area through which gas in the power supply core passes when the explosion-proof valve 2 opens due to thermal runaway, S1 / S2≥1.2. If the main body 31 is rectangular, four lateral openings 5 ​​are formed between the edge of the main body 31 and the cover body 1; if the main body 31 is circular, an annular opening 5 is formed between the edge of the main body 31 and the cover body 1. Figures 1-5 The example shows that the main body 31 is rectangular and forms four oriented side openings 5 ​​between it and the cover body 1.

[0046] With this setup, after testing and verification, it can be ensured that the exhaust requirements are met when the effective flow area of ​​the opening 5 and the effective flow area of ​​the explosion-proof valve 2 after opening satisfy the above relationship.

[0047] In addition, in some optional embodiments, an explosion-proof valve patch 6 is provided on the side surface of the cover plate body 1 facing away from the support frame 3, and the explosion-proof valve patch 6 covers the explosion-proof valve 2.

[0048] Based on the aforementioned cover plate assembly, this application embodiment also provides a battery cell, which includes an electrode group, a housing, and the aforementioned cover plate assembly. The electrode group is located within the housing, and the cover plate assembly is connected to an opening in the housing. Since this battery cell has the aforementioned cover plate assembly, the beneficial effects brought by the cover plate assembly are described above and will not be repeated here.

[0049] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0050] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0051] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0052] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0053] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0054] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A cover plate assembly, characterized in that, include: The cover plate body has explosion-proof holes; An explosion-proof valve is installed in the explosion-proof hole; The support frame is located on the side of the explosion-proof valve closest to the electrode assembly; The support column extends along the thickness direction of the cover plate body, and both ends of the support column are fixedly connected to the cover plate body and the support frame, respectively. When thermal runaway of the battery cell causes the lower plastic to melt, the support frame can abut against the electrode assembly, and the support frame and the cover plate body have an exhaust channel communicating with the explosion-proof hole.

2. The cover plate assembly according to claim 1, characterized in that, The support column is formed on the side of the cover plate body facing the support frame, and the side of the cover plate body away from the support frame is provided with a groove that is directly opposite the position of the support column; the support column is welded to the support frame.

3. The cover plate assembly according to claim 2, characterized in that, On a plane perpendicular to the thickness direction of the cover plate body, the orthographic projection edge of the groove lies within the orthographic projection edge of the support column.

4. The cover plate assembly according to claim 1, characterized in that, The support frame is inserted into the cover plate body along the thickness direction of the cover plate body.

5. The cover plate assembly according to claim 1, characterized in that, The support frame includes: Motherboard body; The plug-in portion is disposed on the side of the main board facing the cover plate body and protrudes relative to the main board body; The cover plate body is provided with a positioning slot that engages with the insertion part.

6. The cover plate assembly according to claim 5, characterized in that, The motherboard body is rectangular, and the plug-in part is L-shaped and located at the corner of the motherboard body.

7. The cover plate assembly according to claim 5, characterized in that, Along the thickness direction of the cover plate body, the thickness of the main body is D, where 0.5mm≤D≤1mm.

8. The cover plate assembly according to claim 7, characterized in that, Along the thickness direction of the cover plate body, the sum of the height of the protrusion of the plug portion relative to the main board body and the thickness of the main board body is H, where H≤2.5mm.

9. The cover plate assembly according to claim 5, characterized in that, The exhaust channel includes an opening formed between the edge of the main body and the cover plate body, the effective flow area of ​​the opening is S1, the opening area of ​​the explosion-proof valve is S2, and S1 / S2≥1.

2.

10. A battery cell, characterized in that, Includes the cover plate assembly as described in any one of claims 1-9.

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