Explosion-proof valve and battery cell

Abstract

The utility model provides a kind of explosion-proof valve, for battery monomer, including opposite first surface and second surface, the direction of the thickness direction of the explosion-proof valve from the second surface to the direction of the first surface is first direction, comprising: valve piece body, including the middle area being provided with weak part, the weak part is thinner than the middle area, the surface where the weak part is the first surface;Reinforcement, including first reinforcement and second reinforcement, it is set in the middle area, and compared with the middle area, it is protruding to the first direction, the weak part surrounds the reinforcement, the first reinforcement surrounds the second reinforcement. The utility model aims at providing a kind of explosion-proof valve and battery monomer, to at least guarantee the reliability of explosion-proof valve.

Description

Technical Field

[0001] This utility model relates to an explosion-proof valve and a battery cell. Background Technology

[0002] Lithium-ion batteries are equipped with explosion-proof valves on their covers. When the battery is subjected to internal or external factors and the internal pressure reaches a threshold, the explosion-proof valve actively opens to release the internal pressure, thereby achieving the purpose of pressure relief and heat dissipation. Due to factors such as the material, thickness, and size of the explosion-proof valve itself, it is prone to deformation under pressure, resulting in a difference in the opening pressure at the battery level compared to the opening pressure at the cover level. Utility Model Content

[0003] In view of the problems existing in the related technologies, the purpose of this utility model is to provide an explosion-proof valve and a battery cell to at least ensure the reliability of the explosion-proof valve.

[0004] To achieve the above objectives, this utility model provides an explosion-proof valve for a battery cell, comprising a first surface and a second surface opposite to each other, wherein the direction from the second surface to the first surface along the thickness direction of the explosion-proof valve is a first direction, comprising: a valve body including an intermediate region having a weak portion, the weak portion being thinner than the intermediate region, the surface where the weak portion is located being the first surface; and a reinforcing portion including a first reinforcing portion and a second reinforcing portion disposed in the intermediate region and protruding in the first direction relative to the intermediate region, the weak portion surrounding the reinforcing portion, and the first reinforcing portion surrounding the second reinforcing portion.

[0005] In some embodiments, the reinforcing portion further includes: a third reinforcing portion disposed in the intermediate region and protruding in the first direction relative to the intermediate region, wherein the second reinforcing portion surrounds the third reinforcing portion.

[0006] In some embodiments, when projected along the first direction, the first reinforcing portion, the second reinforcing portion, and the third reinforcing portion are annular and include two opposing semicircular segments and two straight segments connecting the two semicircular segments. The centers of the corresponding semicircular segments of the first reinforcing portion, the second reinforcing portion, and the third reinforcing portion coincide and their radii decrease sequentially. The straight segments of the first reinforcing portion, the second reinforcing portion, and the third reinforcing portion have the same size.

[0007] In some embodiments, the first reinforcing portion protrudes along the first direction relative to the intermediate region, and the second reinforcing portion protrudes relative to one surface of the intermediate region and is recessed relative to or flush with the other surface of the intermediate region. Projected along the first direction, the first reinforcing portion has a runway shape, and the second reinforcing portion has a combined shape. The runway shape includes two opposing semicircular segments and two straight segments connecting the two semicircular segments. The combined shape includes two opposing semicircles and a rectangle connecting the two semicircles. The centers of the semicircular segments and the corresponding semicircles coincide, and the radius of the semicircles is smaller than that of the semicircular segments. The length of the straight segments is the same as that of the rectangle.

[0008] In some embodiments, projected along the first direction, the first reinforcing portion has a runway shape, and the second reinforcing portion has a combined ring shape. The runway shape includes two opposing semicircular ring segments and two straight segments connecting the two semicircular ring segments. The combined ring shape includes two opposing major arc ring segments and two connecting segments connecting the two major arc ring segments. Each connecting segment includes a minor arc ring segment located in the middle and straight segments located at both ends. The two connecting segments are spaced apart and have the smallest distance at the middle position of the minor arc ring segment. The centers of the semicircular ring segments and the corresponding major arc ring segments coincide, and the radius of the major arc ring segment is smaller than that of the semicircular ring segment.

[0009] In some embodiments, the corner where the reinforcing portion turns relative to the surface of the intermediate region is a rounded corner.

[0010] In some embodiments, the distance between the first reinforcing part and the weak part is ≥0.2mm, and the distance between the second reinforcing part and the first reinforcing part is ≥2mm.

[0011] In some embodiments, the thickness of the first reinforcing portion, the second reinforcing portion, and the third reinforcing portion is greater than or equal to the thickness of the intermediate region, and the distance between the third reinforcing portion and the second reinforcing portion is ≥2mm.

[0012] In some embodiments, the valve body further includes an edge region surrounding the intermediate region, the intermediate region being thinner than the edge region, and projected along the first direction, the ratio of the total area of ​​the reinforcement to the area of ​​the intermediate region being in the range of 0.25 to 0.75.

[0013] Embodiments of this application also provide a battery cell, comprising: a housing that accommodates an electrode assembly and includes an opening; a cover that closes the opening, wherein the cover is provided with the aforementioned explosion-proof valve.

[0014] The beneficial technical effects of this utility model are as follows:

[0015] In the embodiments of this application, at least two types of reinforcing parts (a first reinforcing part and a second reinforcing part) are provided from the outside to the inside in the middle region of the explosion-proof valve, and the first reinforcing part surrounds the second reinforcing part, so as to increase the reinforcing area of ​​the reinforcing part in the middle region, improve the strength of the middle region, and ensure the reliability of the explosion-proof valve. 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figures 1 to 4 The explosion-proof valves of different embodiments of the prior art are shown, wherein Figures 2 to 4 The explosion-proof valves are equipped with reinforcing parts of different shapes.

[0018] Figure 5 A front view of an explosion-proof valve according to a first embodiment of this application is shown.

[0019] Figure 6 It shows along Figure 5 A cross-sectional view taken from the EE line.

[0020] Figure 7 It shows Figure 6 A magnified view of region F.

[0021] Figure 8 A front view of an explosion-proof valve according to a second embodiment of this application is shown.

[0022] Figure 9 It shows along Figure 8 A cross-sectional view taken from the GG line.

[0023] Figure 10 It shows Figure 9 A magnified view of region H.

[0024] Figure 11 A front view of an explosion-proof valve according to a third embodiment of this application is shown.

[0025] Figure 12 It shows along Figure 11 A sectional view taken along line AA.

[0026] Figure 13 It shows Figure 12 A magnified view of region B.

[0027] Figure 14A front view of an explosion-proof valve according to a fourth embodiment of this application is shown.

[0028] Figure 15 It shows along Figure 14 A cross-sectional view taken by the CC line.

[0029] Figure 16 It shows Figure 15 A magnified view of region D.

[0030] Figure 17 A battery cell according to an embodiment of this application is shown.

[0031] Figure 18 A schematic diagram is shown when the electrical device in an embodiment of this application is a vehicle. Detailed Implementation

[0032] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0033] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0034] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0035] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0036] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0037] Figure 1 The prior art explosion-proof valve is shown. The explosion-proof valve is provided with a weak point 20. When the internal pressure of the battery exceeds the rated safety value, the explosion-proof valve is burst by the gas inside the battery at the weak point 20, so that the internal pressure of the battery is released and the battery is prevented from exploding. Figures 2 to 4 The prior art explosion-proof valves of different embodiments are shown. To address the problem of easy deformation of the explosion-proof valves, a certain reinforcing part 30 is provided. The reinforcing part 30 is, for example, as shown in the figure below. Figures 2 to 4 The different shapes of reinforcing ribs shown are all partially covering the explosion-proof valve. The reinforced area of ​​the reinforcing ribs is relatively small, and the area of ​​the explosion-proof valve not covered by the reinforcing ribs still has a certain degree of deformation.

[0038] Figure 5 A front view of an explosion-proof valve 100 according to a first embodiment of this application is shown. Figure 6 It shows along Figure 5 A cross-sectional view taken from the EE line. Figure 7 It shows Figure 6 A magnified view of region F.

[0039] Figure 8 A front view of an explosion-proof valve 100 according to a second embodiment of this application is shown. Figure 9 It shows along Figure 8 A cross-sectional view taken from the GG line. Figure 10 It shows Figure 9 A magnified view of region H.

[0040] Figure 11 A front view of an explosion-proof valve 100 according to a third embodiment of this application is shown. Figure 12 It shows along Figure 11 A sectional view taken along line AA. Figure 13 It shows Figure 12 A magnified view of region B.

[0041] Figure 14 A front view of an explosion-proof valve 100 according to a fourth embodiment of this application is shown. Figure 15 It shows along Figure 14 A cross-sectional view taken by the CC line. Figure 16 It shows Figure 15 A magnified view of region D.

[0042] Figure 17 A battery cell 500 according to an embodiment of this application is shown, including a cover plate 200, an electrode assembly 300, and a housing 400. The housing 400 accommodates the electrode assembly 300 and includes an opening, the cover plate 200 closes the opening, and an explosion-proof valve 100 of any one of the first to fourth embodiments is provided on the cover plate 200.

[0043] The first to fourth embodiments provide an explosion-proof valve 100, which includes a first surface (e.g., a surface facing away from the electrode assembly 300) and a second surface (e.g., a surface facing the electrode assembly 300). The explosion-proof valve 100 includes a valve body 10 and a reinforcing portion 30 disposed on the valve body 10. The valve body 10 includes an intermediate region 12 with a thinner ... In the embodiments of this application, at least two reinforcing parts (a first reinforcing part 31 and a second reinforcing part 32) surrounded by a weak part 20 are provided from the outside to the inside in the middle region 12 of the explosion-proof valve 100, and the first reinforcing part 31 surrounds the second reinforcing part 32 to increase the reinforcing area of ​​the reinforcing part 30 in the middle region 12, improve the strength of the middle region 12, and ensure the reliability of the explosion-proof valve 100.

[0044] In some embodiments, the weak part 20 is a groove, and the reinforcing part 30 is integrally formed with the valve plate body 10.

[0045] See Figure 17The cover plate 200 includes a cover plate body 210 and an explosion-proof port 220 disposed on the cover plate body 210. The explosion-proof valve 100 is installed in the explosion-proof port 220, and the shape of the explosion-proof valve 100 matches the explosion-proof port 220. The valve plate body 10 of the first to fourth embodiments also includes an edge region 14 surrounding the intermediate region 12, the intermediate region 12 being thinner than the edge region 14. The edge region 14 is used for a sealing connection with the cover plate body 210 and is connected to the periphery of the explosion-proof port 220. The thickness of the edge region 14 is greater than the thickness of the intermediate region 12, so that a more reliable connection is formed between the edge region 14 and the cover plate body 210. The edge region 14 is connected to the inner surface of the cover plate body 210, and the connection method can be welding, such as laser welding. Projected along the thickness direction of the valve plate body 10 or along the first direction, the ratio of the total area of ​​the reinforcing portion 30 to the area of ​​the intermediate region 12 is in the range of 0.25 to 0.75. If the area occupied by the reinforcing part 30 in the intermediate region 12 is too small, for example, less than 0.25, the reinforcing area of ​​the reinforcing part 30 is too small, the strength of the intermediate region 12 is insufficient, and the explosion-proof valve 100 is prone to deformation. The strength of the intermediate region 12 increases with the increase of the area of ​​the reinforcing part 30. When the area of ​​the reinforcing part 30 increases to a certain extent, the increase in strength of the intermediate region 12 becomes smaller until it approaches 0. If the area occupied by the reinforcing part 30 in the intermediate region 12 is too large, for example, greater than 0.75, compared with the area ratio of 0.75, the reinforcing effect on the intermediate region 12 is negligible, which will further cause problems affecting the positional arrangement of the weak part 20, the first reinforcing part 31, the second reinforcing part 32 and / or the third reinforcing part 33.

[0046] See Figures 5 to 7 In the first embodiment, the reinforcing portion 30 further includes a third reinforcing portion 33 disposed in the intermediate region 12. The third reinforcing portion 33 protrudes in the first direction relative to the intermediate region 12, and the second reinforcing portion 32 surrounds the third reinforcing portion 33. In this application, the first reinforcing portion 31 surrounds the second reinforcing portion 32, and the second reinforcing portion 32 surrounds the third reinforcing portion 33. The annular first reinforcing portion 31 and the second reinforcing portion 32 have stronger resistance to deformation, which is beneficial to maintaining the shape of the intermediate region 12.

[0047] In the first to fourth embodiments, the first reinforcing part 31, the second reinforcing part 32 (and the third reinforcing part 33) protrude along the thickness direction of the valve plate body 10, that is, the protrusion direction of the first reinforcing part 31, the second reinforcing part 32 (and the third reinforcing part 33) is perpendicular to the surface of the middle region 12, which provides better support compared to other directions.

[0048] The thicknesses of the first reinforcing part 31, the second reinforcing part 32 (and the third reinforcing part 33) are greater than or equal to the thickness of the intermediate region 12. In the first, third, and fourth embodiments, the thicknesses of the first reinforcing part 31, the second reinforcing part 32 (and the third reinforcing part 33) can be the same as the thickness of the intermediate region 12. That is, although the reinforcing part 30 protrudes from one side of the intermediate region 12, it is recessed on the other side, and the thickness of the explosion-proof valve 100 at the reinforcing part 30 remains unchanged. This ensures the support effect for the intermediate region 12 while avoiding further increasing the mass of the explosion-proof valve 100. In the second embodiment, the thickness of the first reinforcing part 31 can be the same as the thickness of the intermediate region 12, and the thickness of the second reinforcing part 32 can be greater than the thickness of the intermediate region 12 to further enhance the support effect for the intermediate region 12.

[0049] For the first embodiment, see Figure 5 Projected along the first direction, the first reinforcing part 31, the second reinforcing part 32, and the third reinforcing part 33 are annular, and include two opposing semicircular segments and two straight segments connecting the two semicircular segments. The centers O1 and O2 of the corresponding semicircular segments of the first reinforcing part 31, the second reinforcing part 32, and the third reinforcing part 33 coincide, and the radius R1 of the semicircular segment of the first reinforcing part 31 is greater than the radius R2 of the semicircular segment of the second reinforcing part 32, which is greater than the radius R3 of the semicircular segment of the third reinforcing part 33. The straight segments of the first reinforcing part 31, the second reinforcing part 32, and the third reinforcing part 33 have the same dimension L4. Furthermore, the weak portion 20 conforms to a section of the first reinforcing portion 31, the second reinforcing portion 32, and the third reinforcing portion 33. The weak portion 20 also includes a semi-circular ring segment whose center coincides with the centers O1 and O2. The outer edges of the intermediate region 12 and the valve body 10 also conform to the first reinforcing portion 31, the second reinforcing portion 32, and the third reinforcing portion 33. That is, the outer edges of the intermediate region 12 and the valve body 10 also include semi-circular arcs whose centers coincide with the centers O1 and O2, with radii R5 and R6 of 11.50 mm and 13.50 mm, respectively. The weak portion 20 is not a complete annular structure but includes a notch, the size of which is L5 ≤ L4.

[0050] The distance L1 between the first reinforcing part 31 and the weak part 20 is ≥0.2mm, and the distance L2 between the second reinforcing part 32 and the first reinforcing part 31 is ≥2mm; for the first embodiment, the distance L3 between the third reinforcing part 33 and the second reinforcing part 32 is ≥2mm. The shortest distance L1 between the first reinforcing part 31 and the weak part 20 is ≥0.2mm, which is at least greater than the processing error. The reinforcing area of ​​the reinforcing part 30 includes not only the reinforcing part 30 itself, but also the area around the reinforcing part 30. The strength of the intermediate region 12 increases as the distance between the first reinforcing part 31, the second reinforcing part 32 and / or the third reinforcing part 33 decreases. When the distance between the first reinforcing part 31, the second reinforcing part 32 and / or the third reinforcing part 33 decreases to a certain extent, the strength increase of the intermediate region 12 becomes smaller until it approaches 0. When the minimum distance between the first reinforcing part 31, the second reinforcing part 32 and / or the third reinforcing part 33 is ≥2mm, the reinforcing parts 30 are not too dense while ensuring the reinforcement effect on the intermediate region 12. Furthermore, the number of reinforcing portions 30 in the embodiments of this application is not limited to three in the first embodiment and two in the second to fourth embodiments; the number of reinforcing portions 30 can be adjusted according to the size of the explosion-proof valve 100. Also, the annular third reinforcing portion 33 in the first embodiment can be a solid structure like the second reinforcing portion 32 in the second and third embodiments, i.e., a single reinforcing ridge.

[0051] See Figure 6 The thickness T1 of the edge region 14 is greater than the thickness T2 of the middle region 12.

[0052] See Figure 7 The distance T3 between the top surfaces of the first reinforcing part 31, the second reinforcing part 32, and the third reinforcing part 33 and the top surface of the intermediate region 12 is greater than 0. The distance T4 between the bottom surfaces of the first reinforcing part 31, the second reinforcing part 32, and the third reinforcing part 33 and the bottom surface of the intermediate region 12 is greater than 0. Furthermore, the corners where the first reinforcing part 31, the second reinforcing part 32, and the third reinforcing part 33 transition relative to the surface of the intermediate region 12 are rounded. This smooth transition further enhances the supporting effect of the reinforcing part 30, contributing to structural stability.

[0053] See Figures 8 to 10 In the second embodiment, the first reinforcing part 31 protrudes along the first direction relative to the middle region 12, and the second reinforcing part 32 protrudes relative to one surface of the middle region 12 and is flush with the other surface of the middle region 12.

[0054] See Figure 8Projected along a first direction, the first reinforcing part 31 has a runway shape, and the second reinforcing part 32 has a combined shape. The runway shape of the first reinforcing part 31 includes two opposing semicircular segments and two straight segments connecting the two semicircular segments. The combined shape of the second reinforcing part 32 includes two opposing semicircles and a rectangle connecting the two semicircles. The centers O1 and O2 of the semicircular segments and the corresponding semicircles coincide, and the radius R2 of the semicircles is smaller than the radius R1 of the semicircular segments. The lengths of the straight segments and the rectangles are the same (both are L4).

[0055] Figure 10 In the middle, the thickness T5 of the second reinforcing part 32 is greater than T2.

[0056] See Figures 11 to 13 In the third embodiment, the first reinforcing portion 31 protrudes along the first direction relative to the intermediate region 12, and the second reinforcing portion 32 protrudes from one surface of the intermediate region 12 and is recessed from the other surface of the intermediate region 12 (a difference from the second embodiment). The second reinforcing portion 32 in the third embodiment can also be referred to as a convex hull.

[0057] Figure 13 In the middle, the radius R9 of the turning angle where the second reinforcing part 32 itself turns is greater than the radius R7 of the turning angle where the first reinforcing part 31 turns relative to the surface of the middle region 12 and the radius R8 of the turning angle where the first reinforcing part 31 itself turns.

[0058] See Figures 14 to 16 In the fourth embodiment, projected along the first direction, the first reinforcing part 31 has a runway shape, and the second reinforcing part 32 has a combined ring shape. The runway shape of the first reinforcing part 31 includes two opposing semicircular ring segments and two straight segments connecting the two semicircular ring segments. The combined ring shape of the second reinforcing part 32 includes two opposing major arc ring segments and two connecting segments connecting the two major arc ring segments. Each connecting segment includes a minor arc ring segment located in the middle and straight segments located at both ends. The two connecting segments are separated and the distance is minimized at the middle position of the minor arc ring segment. The radius of the major arc ring segment is smaller than the radius of the minor arc ring segment. The centers O1 and O2 of the semicircular ring segments of the first reinforcing part 31 and the corresponding major arc ring segments of the second reinforcing part 32 coincide, and the radius of the major arc ring segment is smaller than that of the semicircular ring segment.

[0059] In the first to fourth embodiments, a section of the first reinforcing part 31 conforms to the weak part 20, and the shape of the second reinforcing part 32 may be the same as or different from the shape of the first reinforcing part 31; in the first embodiment, the shape of the third reinforcing part 33 may be the same as or different from the shape of the first reinforcing part 31. When a section of the first reinforcing part 31 conforms to the weak part 20, and the shapes of the first reinforcing part 31, the second reinforcing part 32 (and the third reinforcing part 33) are the same, it is beneficial to keep the distance between any two constant, ensuring a balanced reinforcement effect and avoiding insufficient local reinforcement. In embodiments where the shapes of the first reinforcing part 31, the second reinforcing part 32 (and the third reinforcing part 33) are different, such as the second and third embodiments, the shape of the outer wall of the second reinforcing part 12 can be the same as the shape of the side wall of the first reinforcing part 31, which can also ensure the reinforcement effect in each area. In the fourth embodiment, although the distance between the second reinforcing part 32 and the first reinforcing part 31 is not constant, the specific shape of the second reinforcing part 32 is used to focus on reinforcing the relatively open (weak structural strength) central area of ​​the explosion-proof valve 100, thereby ensuring the overall structural stability of the explosion-proof valve 100.

[0060] Compared with the prior art, the explosion-proof valve 100 of the present application embodiment has a greater burst pressure, i.e., greater strength, under the condition that the thickness of the weak part 20 is the same; under the condition that the thickness of the weak part 20 is the same, the difference between the battery-level burst value and the cover-level burst value of the lithium-ion battery using the explosion-proof valve 100 of the present application embodiment is much smaller than that of the lithium-ion battery using the explosion-proof valve of the prior art; the limit number of breaths of the lithium-ion battery using the explosion-proof valve 100 of the present application embodiment is higher than that of the lithium-ion battery using the explosion-proof valve of the prior art, i.e., longer life and better reliability.

[0061] This utility model also provides a battery cell 500 and an electrical device 1000. The battery cell 500 includes the explosion-proof valve 100 mentioned above. For ease of explanation, the following embodiments will use a vehicle as an example for the electrical device 1000. Figure 18This illustration shows a schematic diagram of an electrical device 1000 in an embodiment of this application when it is a vehicle. The vehicle's interior is equipped with a battery 1002 comprising multiple battery cells 500. The battery 1002 can be located at the bottom, head, or tail of the vehicle body 1001. The battery 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The working part of the electrical device 1000 is electrically connected to the battery 1002 to obtain electrical energy. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The battery 1002 provides electrical energy support for the vehicle's operation or the operation of its internal electrical components. However, in other embodiments, the electrical device 1000 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part is a unit component that can obtain electrical energy from the battery 1002 and perform corresponding tasks, such as a fan blade rotation unit or a vacuum cleaner's suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electrical device 1000.

[0062] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An explosion-proof valve for a battery cell, comprising a first surface and a second surface opposite to each other, wherein a first direction is defined as the direction along the thickness direction of the explosion-proof valve from the second surface to the first surface, characterized in that, include: The valve body includes a middle region having a weak portion, the weak portion being thinner than the middle region, and the surface where the weak portion is located is the first surface; The reinforcing portion, including a first reinforcing portion and a second reinforcing portion, is disposed in the intermediate region and protrudes in the first direction relative to the intermediate region. The weak portion surrounds the reinforcing portion, and the first reinforcing portion surrounds the second reinforcing portion.

2. The explosion-proof valve according to claim 1, characterized in that, The reinforcing part also includes: A third reinforcing portion is disposed in the intermediate region and protrudes along the first direction relative to the intermediate region, and the second reinforcing portion surrounds the third reinforcing portion.

3. The explosion-proof valve according to claim 2, characterized in that, Projected along the first direction, the first reinforcing part, the second reinforcing part, and the third reinforcing part are annular, and include two opposing semicircular segments and two straight segments connecting the two semicircular segments. The centers of the corresponding semicircular segments of the first reinforcing part, the second reinforcing part, and the third reinforcing part coincide, and their radii decrease sequentially. The straight segments of the first reinforcing part, the second reinforcing part, and the third reinforcing part have the same dimensions.

4. The explosion-proof valve according to claim 1, characterized in that, The first reinforcing portion protrudes along the first direction relative to the intermediate region, and the second reinforcing portion protrudes from one surface of the intermediate region and is recessed from or flush with the other surface of the intermediate region. Projected along the first direction, the first reinforcing part has a runway shape, and the second reinforcing part has a combined shape. The track shape includes two opposing semicircular segments and two straight segments connecting the two semicircular segments. The combined shape comprises two opposing semicircles and a rectangle connecting the two semicircles. The center of the semicircular segment coincides with the center of the corresponding semicircle, and the radius of the semicircle is smaller than that of the semicircular segment. The length of the straight line segment is the same as that of the rectangle.

5. The explosion-proof valve according to claim 1, characterized in that, Projected along the first direction, the first reinforcing part has a runway shape, and the second reinforcing part has a combined ring shape. The track shape includes two opposing semicircular segments and two straight segments connecting the two semicircular segments. The combined ring shape includes two opposing major arc ring segments and two connecting segments connecting the two major arc ring segments. Each connecting segment includes a minor arc ring segment in the middle and straight segments at both ends. The two connecting segments are spaced apart and have the smallest distance at the middle position of the minor arc ring segment. The centers of the semicircular ring segment and the corresponding major arc ring segment coincide, and the radius of the major arc ring segment is smaller than that of the semicircular ring segment.

6. The explosion-proof valve according to claim 1, characterized in that, The corner where the reinforcing part turns from the surface of the intermediate region is a rounded corner.

7. The explosion-proof valve according to claim 1, characterized in that, The distance between the first reinforcing part and the weak part is ≥0.2mm. The distance between the second reinforcing part and the first reinforcing part is ≥2mm.

8. The explosion-proof valve according to claim 2, characterized in that, The thickness of the first reinforcing part, the second reinforcing part, and the third reinforcing part is greater than or equal to the thickness of the intermediate region, and the distance between the third reinforcing part and the second reinforcing part is ≥2mm.

9. The explosion-proof valve according to claim 1, characterized in that, The valve body also includes an edge region surrounding the central region, the central region being thinner than the edge region. Projected along the first direction, the ratio of the total area of ​​the reinforcing portion to the area of ​​the intermediate region is in the range of 0.25 to 0.

75.

10. A single battery cell, characterized in that, include: A housing that accommodates the electrode assembly and includes an opening; A cover plate, which closes the opening, and the cover plate is provided with an explosion-proof valve as described in any one of claims 1-9.

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