Cover plate for cylindrical battery and cylindrical battery

Abstract

The invention relates to the technical field of batteries, and particularly provides a cover plate for a cylindrical battery and the cylindrical battery. Specifically, the cover plate comprises a first plate body and a second plate body, the first plate body is higher than the second plate body, the first plate body is used for supporting a roll core of the battery, and the second plate body is provided with an anti-explosion valve. The cover plate is provided with the first plate body capable of supporting the roll core, the supporting force on the roll core is larger, the roll core can be effectively prevented from collapsing when the battery is subjected to vibration impact, in addition, the anti-explosion valve is arranged on the second plate body, and the inner surface of the second plate body is lower than the inner surface of the first plate body, so that a buffer space is formed between the anti-explosion valve and the roll core, and the anti-explosion effect is improved. And even if the roll core collapses, the explosion-proof valve on the cover plate cannot be extruded, so that the condition that the explosion-proof valve is opened in advance can be avoided, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and specifically provides a cover plate for a cylindrical battery and a cylindrical battery. Background Art

[0002] As the energy crisis and environmental pollution problems become increasingly serious worldwide, people's requirements for energy conservation and emission reduction in automobiles are gradually increasing. New energy vehicles have attracted more and more attention due to their low noise, pollution-free and high energy efficiency, thus promoting the accelerated development of new energy vehicles. At present, new energy vehicles usually use batteries as a power source, which provides a broad space for the application and development of batteries.

[0003] Cylindrical batteries are attracting more and more attention. Cylindrical batteries mainly include shell, cover, winding core, negative electrode collector and positive electrode collector. The bottom end of the shell is open, the cover is set at the bottom of the shell to close the bottom opening, and the winding core, negative electrode collector and positive electrode collector are all installed in the shell.

[0004] The winding core is generally formed by winding the positive electrode sheet, the negative electrode sheet and the diaphragm, a positive electrode ear is arranged at the top of the winding core, and the positive electrode ear is electrically connected to the positive electrode sheet, a negative electrode ear is arranged at the bottom of the winding core, and the negative electrode ear is electrically connected to the negative electrode sheet, the positive current collecting disk is located directly above the winding core, the positive current collecting disk is fixedly connected to the shell, the positive electrode ear of the winding core is electrically connected to the positive current collecting disk, and the positive electrode ear and the positive current collecting disk are generally fixedly connected by welding, the negative current collecting disk is located directly below the winding core, the negative current collecting disk is also fixedly connected to the shell, the negative electrode ear of the winding core is electrically connected to the negative current collecting disk, and the negative electrode ear and the negative current collecting disk are generally fixedly connected by welding, in order to avoid short circuit, an insulating structure is arranged between the positive current collecting disk or the negative current collecting disk and the shell.

[0005] Existing batteries generally have explosion-proof valves installed on the cover plate, which is located directly below the negative electrode current collector. Due to the low structural strength of the negative electrode current collector, when the battery is subjected to vibration impact, the winding core is prone to collapse and the negative electrode current collector is deformed, thereby squeezing the explosion-proof valve on the cover plate. In severe cases, the explosion-proof valve may be opened prematurely, shortening the battery life.

[0006] Therefore, this field needs a new technical solution to solve the above problems. Summary of the invention

[0007] The present invention aims to solve the above technical problem, that is, to solve the problem that the collapse of the roll core of the existing cylindrical battery may cause the explosion-proof valve arranged on the cover plate to open prematurely, resulting in a shortened battery life.

[0008] In a first aspect, the present invention provides a cover plate for a cylindrical battery, the cover plate comprising a first plate body and a second plate body, the first plate body being higher than the second plate body, the first plate body being used to support a winding core of the battery, and the second plate body being provided with an explosion-proof valve.

[0009] In a preferred technical solution of the above cover plate, the second plate body includes a plurality of strip plates extending in the radial direction of the cover plate, and the plurality of strip plates are distributed at intervals in the circumferential direction of the cover plate.

[0010] In a preferred technical solution of the above cover plate, the explosion-proof valve is formed as an explosion-proof valve notch provided along the edge of the strip plate.

[0011] In a preferred technical solution of the above cover plate, the first plate body includes a plurality of sub-plate bodies, the plurality of sub-plate bodies are distributed at intervals along the circumference of the cover plate, and two adjacent sub-plate bodies are separated by the strip plate.

[0012] In the preferred technical solution of the above cover plate, the sub-plate body is arranged in a fan shape.

[0013] In the preferred technical solution of the above cover plate, the minimum distance from the center point of the second plate body to the sub-plate body is not less than 5.0 mm.

[0014] In a preferred technical solution of the above cover plate, the second plate body is provided with a liquid injection hole, and the liquid injection hole is located at the center of the cover plate.

[0015] In a preferred technical solution of the above cover plate, a positioning groove is provided on the outer surface of the cover plate at a position corresponding to the injection hole.

[0016] In a preferred technical solution of the above cover plate, a height difference between the first plate body and the second plate body is not greater than 2.0 mm.

[0017] In a second aspect, the present invention provides a cylindrical battery, which includes the above-mentioned cover plate; a shell, one side of the shell has an opening, and the cover plate is arranged at the opening; a winding core, which is arranged in the shell; wherein the first plate is electrically connected to the negative electrode of the winding core.

[0018] When the above technical solution is adopted, the cover plate of the present invention has a first plate body capable of supporting the winding core. The structural strength of the cover plate is higher than that of the negative electrode current collecting disk, and the supporting force on the winding core is greater. When the battery is subjected to vibration impact, the winding core can be effectively prevented from collapsing. In addition, the cover plate of the present invention arranges the explosion-proof valve on the second plate body, and the inner surface of the second plate body is lower than the inner surface of the first plate body. In this way, a buffer space is created between the explosion-proof valve and the winding core. Even if the winding core collapses, the explosion-proof valve on the cover plate will not be squeezed, thereby avoiding the premature opening of the explosion-proof valve and extending the service life of the battery.

[0019] Furthermore, the second plate body of the present invention includes a plurality of strip plates spaced apart circumferentially along the cover plate, and the explosion-proof valve is formed as an explosion-proof valve notch arranged along the edge of the strip plate. Compared with the circular explosion-proof valve in the prior art, the special shape of the explosion-proof valve of the present invention has better structural strength and stronger pressure-bearing capacity, and is not prone to premature opening when squeezed by the winding core, thereby further extending the service life of the battery.

[0020] Furthermore, the cover plate of the present invention configures the first plate body to be composed of a plurality of sub-plate bodies distributed at intervals along the circumference of the cover plate, and each sub-plate body can support the winding core of the shell. Through such a configuration, the supporting force of the winding core can be further improved to prevent the winding core from collapsing. In addition, when the battery has thermal runaway, each sub-plate body can also effectively prevent the internal high-temperature objects from being directly sprayed out of the shell when the battery has thermal runaway, causing heat spread.

[0021] Furthermore, the present invention arranges the multiple sub-plates of the first plate body in a fan shape. Such an arrangement is conducive to increasing the area of ​​the first plate body, so that the negative electrode ears of the inner circle and the negative electrode ears of the outer circle can be welded to the first plate body of the cover plate, thereby reducing the internal resistance of the battery and increasing the battery power.

[0022] Furthermore, the cover plate of the present invention can ensure that the explosion-proof valve has a sufficient valve opening area by setting the minimum distance from the center point of the second plate body to the sub-plate body to be no less than 5.0 mm, thereby improving the safety of the battery.

[0023] Furthermore, the cover plate of the present invention is arranged at the center of the cover plate through the injection hole. During injection, the electrolyte can be directly injected into the battery through the center hole of the winding core, which is beneficial to improving the injection efficiency.

[0024] Furthermore, the cover plate of the present invention is provided with a sealing nail positioning groove for accommodating the sealing injection hole on the outer surface, thereby improving the connection stability between the sealing nail and the cover plate and improving the sealing of the injection hole.

[0025] In addition, the cylindrical battery further provided by the present invention on the basis of the above technical solution includes the above cover plate, and thus has the technical effect possessed by the above cover plate. Compared with the cylindrical battery before the improvement, the cylindrical battery of the present invention supports the winding core in the shell through the first plate body of the cover plate, and can effectively prevent the winding core from collapsing when the battery is subjected to vibration impact. In addition, by arranging the explosion-proof valve on the second plate body, since the inner surface of the second plate body is lower than the inner surface of the first plate body, a buffer space is created between the explosion-proof valve and the winding core. Even if the winding core collapses, the explosion-proof valve on the cover plate will not be squeezed, thereby avoiding the premature opening of the explosion-proof valve and extending the service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a partial cross-sectional view of a cylindrical battery of the present invention;

[0028] Figure 2 It is a schematic structural diagram of the shell and cover plate of the cylindrical battery of the present invention;

[0029] Figure 3 It is a schematic structural diagram of the cover plate of the cylindrical battery of the present invention.

[0030] List of reference numerals:

[0031] 1. Shell;

[0032] 2. Cover plate; 21. First plate body; 22. Second plate body; 23. Explosion-proof valve notch; 24. Liquid injection hole; 25. Positioning groove; 211. Sub-plate body; 221. Strip plate;

[0033] 3. winding core; 31. negative electrode ear; 32. center hole. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0035] It should be noted that in the description of the present invention, the terms "inside", "outside", "upper", "lower", "top", "bottom" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "setting", "connection" and "installation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Specifically, first refer to Figure 1 , Figure 1 It is a partial cross-sectional view of a cylindrical battery of the present invention.

[0038] The present invention provides a cylindrical battery, such as Figure 1 As shown, the cylindrical battery of the present invention comprises a housing 1, a cover plate 2 and a winding core 3. The housing 1 has an opening at the bottom, the cover plate 2 is used to close the opening, and the winding core 3 is installed in the housing 1.

[0039] For example, Figure 1 As shown, the cover plate 2 is welded and fixed to the shell 1 , and the cover plate 2 is located below the winding core 3 and can support the winding core 3 .

[0040] As can be seen from the background technology, due to the low structural strength of the negative electrode current collector, when the battery is subjected to vibration impact, the winding core is prone to collapse and the negative electrode current collector is deformed, thereby squeezing the explosion-proof valve on the cover plate 2. In severe cases, the explosion-proof valve may be opened prematurely, resulting in a shortened battery life.

[0041] The battery of the present invention directly supports the winding core 3 in the shell 1 through the cover plate 2. The structural strength of the cover plate 2 is higher than that of the negative electrode collector disk, and the supporting force on the winding core 3 is greater. When the battery is subjected to vibration impact, the winding core 3 can be effectively prevented from collapsing.

[0042] Continue reading Figure 1 , and then see Figure 2 and Figure 3 ,in, Figure 2 It is a schematic structural diagram of the shell and cover plate of the cylindrical battery of the present invention; Figure 3 It is a structural schematic diagram of a cover plate of a cylindrical battery of the present invention; Figure 2 What we see is the outer surface of the cover plate 2. Figure 3 What is seen is the inner surface of the cover plate 2.

[0043] like Figures 1 to 3 As shown, the cover plate 2 of the present invention includes a first plate body 21 and a second plate body 22, wherein the first plate body 21 is higher than the second plate body 22, the first plate body 21 is used to support the winding core 3 of the battery, and the second plate body 22 is provided with an explosion-proof valve.

[0044] That is to say, the inner surface of the first plate body 21 is higher than the inner surface of the second plate body 22, wherein the first plate body 21 can be convex along the direction from the outer surface of the cover plate 2 toward the inner surface of the cover plate 2 so that the inner surface of the first plate body 21 is higher than the inner surface of the second plate body 22, or the second plate body 22 can be recessed along the direction from the inner surface of the cover plate 2 toward the outer surface of the cover plate 2 so that the inner surface of the first plate body 21 is higher than the inner surface of the second plate body 22.

[0045] The inner surface of the cover plate 2 is the side of the cover plate 2 close to the winding core 3 (from Figure 1 The upper surface of the cover plate 2 is the upper surface of the cover plate 2 when viewed from above, and the outer surface of the cover plate 2 is the side of the cover plate 2 away from the winding core 3 (from the Figure 1 The lower surface of the cover plate 2 when viewed from above).

[0046] That is to say, the cover plate 2 of the present invention has two plates, namely the first plate body 21 and the second plate body 22. The inner surfaces of the first plate body 21 and the second plate body 22 are not on the same plane, and the inner surface of the first plate body 21 is higher than the inner surface of the second plate body 22. The first plate body 21 is used to support the core 3 in the shell 1 to increase the supporting force for the core 3 and prevent the core 3 from collapsing. The explosion-proof valve is arranged on the second plate body 22. Since the inner surface of the second plate body 22 is lower than the inner surface of the first plate body 21, a buffer space can be formed between the explosion-proof valve and the core 3. In this way, even if the core 3 collapses, it will not cause squeezing of the explosion-proof valve on the cover plate 2, thereby avoiding the premature opening of the explosion-proof valve and extending the service life of the battery.

[0047] It should be noted that, in practical applications, those skilled in the art can make the first plate 21 protrude along the outer surface of the cover plate 2 toward the inner surface of the cover plate 2, so as to form a height difference between the first plate 21 and the second plate 22. Figure 1 From the top, the first plate 21 is convex upward in the vertical direction, or the second plate 22 can be recessed along the inner surface of the cover plate 2 toward the outer surface of the cover plate 2 to form a height difference between the first plate 21 and the second plate 22. Figure 1 Seen from above, the second plate body 22 is sunken downward in the vertical direction. Such flexible adjustment and change does not deviate from the principle and scope of the present invention and should be limited within the protection scope of the present invention.

[0048] In a preferred case, the first plate body 21 of the cover plate 2 protrudes 1.0 mm from the outer surface of the cover plate 2 toward the inner surface of the cover plate 2 , that is, the height difference between the inner surface of the first plate body 21 and the inner surface of the second plate body 22 is 1.0 mm.

[0049] It should be noted that the protrusion height of the first plate body 21 is not limited to the above-mentioned 1.0 mm. For example, those skilled in the art may also set the protrusion height of the first plate body 21 to 0.3 mm, 0.5 mm, 0.8 mm, 1.2 mm, 1.3 mm, 1.5 mm, 1.8 mm or 2.0 mm, etc. in actual applications. Such flexible adjustment and change does not deviate from the principle and scope of the present invention and should be limited within the protection scope of the present invention.

[0050] Of course, the present invention preferably sets the height difference between the first plate body 21 and the second plate body 22 to be no greater than 2.0 mm.

[0051] In another preferred embodiment, the second plate body 22 of the cover plate 2 is recessed 1.0 mm along the inner surface of the cover plate 2 toward the outer surface of the cover plate 2 , that is, the height difference between the inner surface of the first plate body 21 and the inner surface of the second plate body 22 is 1.0 mm.

[0052] It should be noted that the recessed depth of the second plate body 22 is not limited to the above-mentioned 1.0 mm. For example, those skilled in the art may also set the recessed depth of the second plate body 22 to 0.3 mm, 0.5 mm, 0.8 mm, 1.2 mm, 1.3 mm, 1.5 mm, 1.8 mm or 2.0 mm, etc. in actual applications. Such flexible adjustment and change does not deviate from the principle and scope of the present invention and shall be limited within the protection scope of the present invention.

[0053] Of course, the present invention preferably sets the difference between the second plate bodies 22 to be no greater than 2.0 mm.

[0054] Preferably, if Figure 2 and Figure 3 As shown, the second plate body 22 of the cover plate 2 of the present invention includes a plurality of strip plates 221 . The strip plates 221 extend in the radial direction of the cover plate 2 . The plurality of strip plates 221 are distributed at intervals along the circumference of the cover plate 2 .

[0055] Preferably, if Figure 2 and Figure 3 As shown, the explosion-proof valve is formed as an explosion-proof valve notch 23 provided along the edge of the strip plate 221 .

[0056] That is to say, explosion-proof valve notches 23 are provided on the outer surface of the cover plate 2 near the edge of each strip plate 221 .

[0057] The second plate body 22 of the cover plate 2 of the present invention includes a plurality of strip plates 221 spaced apart along the circumference of the cover plate 2, and explosion-proof valve notches 23 are provided on the outer surface of the cover plate 2 near the edge of each strip plate 221. Compared with the explosion-proof valve with a circular structure in the prior art, the explosion-proof valve with a special shape of the present invention has better structural strength and stronger pressure-bearing capacity, and is not prone to premature opening when squeezed by the winding core 3, thereby further extending the service life of the battery.

[0058] For example, Figure 3 As shown, there are three strip plates 221, which are evenly distributed along the circumference of the cover plate 2. Each strip plate 221 radially extends from the center of the cover plate 2 to the edge of the cover plate 2. Figure 2As shown, three sections of explosion-proof valve notches 23 connected end to end are provided on the outer surface of the cover plate 2, and each section of the explosion-proof valve notch 23 extends along the edge of the corresponding strip plate 221. The shape of the explosion-proof valve is approximately a "human" shape. Compared with the circular explosion-proof valve in the prior art, the explosion-proof valve of this special shape has better structural strength and stronger pressure-bearing capacity.

[0059] It should be noted that the number of the strip plates 221 is not limited to the above-mentioned three. For example, skilled technicians can also set the number of the strip plates 221 to two or four, etc. in actual applications. Such adjustments and changes to the specific number of the strip plates 221 do not deviate from the principle and scope of the present invention and should be limited within the protection scope of the present invention.

[0060] Preferably, if Figure 2 and Figure 3 As shown, the first plate body 21 of the cover plate 2 of the present invention includes a plurality of sub-plate bodies 211, which are distributed at intervals along the circumference of the cover plate 2, and two adjacent sub-plate bodies 211 are separated by a strip plate 221, and each sub-plate body 211 is used to support the winding core 3.

[0061] The cover plate 2 of the present invention is configured such that the first plate body 21 is composed of a plurality of sub-plate bodies 211 distributed at intervals along the circumference of the cover plate 2, and each sub-plate body 211 can support the winding core 3 of the shell 1. In this way, the supporting force of the cover plate 2 on the winding core 3 can be further improved, which is more conducive to preventing the winding core 3 from collapsing. In addition, when the battery has thermal runaway, each sub-plate body 211 can also effectively prevent the internal high-temperature objects from being directly sprayed out of the shell 1 when the battery has thermal runaway, causing heat spread.

[0062] For example, Figure 2 and Figure 3 As shown, the first plate body 21 is composed of three sub-plate bodies 211, and the three sub-plate bodies 211 are evenly distributed along the circumference of the cover plate 2. The number of the strip plates 221 is also three, and the three strip plates 221 are respectively arranged between two adjacent sub-plate bodies 211, that is, two adjacent sub-plate bodies 211 are separated by a strip plate 221.

[0063] It should be noted that the number of sub-board bodies 211 is not limited to the above-mentioned three. For example, technical personnel in practical applications can also set the number of sub-board bodies 211 to two or four, etc. Such adjustments and changes to the specific number of sub-board bodies 211 do not deviate from the principle and scope of the present invention and should be limited within the protection scope of the present invention.

[0064] Preferably, if Figure 1 and Figure 2 As shown, each sub-plate body 211 of the first plate body 21 is directly electrically connected to the negative electrode tab 31 of the winding core 3 .

[0065] That is to say, the first plate body 21 of the cover plate 2 of the present invention can not only be used to support the winding core 3, but also can be used to directly connect with the negative electrode of the winding core 3. In other words, the battery of the present invention eliminates the negative electrode collector plate, and directly electrically connects the negative electrode ear 31 of the winding core 3 with the first plate body 21 on the cover plate 2. Through such a setting, it is possible to increase the space utilization rate in the height direction of the battery and improve the energy density of the battery, and reduce the number of structural parts of the battery, thereby reducing the weight of the battery.

[0066] It should be noted that, in practical applications, the negative electrode tab 31 of the winding core 3 is preferably fixedly connected to the sub-plate body 211 of the cover plate 2 by welding.

[0067] Preferably, if Figure 2 and Figure 3 As shown, in the cover plate 2 of the present invention, each sub-plate body 211 is configured to be fan-shaped.

[0068] The cover plate 2 of the present invention is configured as a fan through each sub-plate body 211 of the first plate body 21. Such a structural design is very beneficial to increasing the area of ​​the first plate body 21, so that the negative electrode tab 31 located on the inner circle of the winding core 3 and the negative electrode tab 31 located on the outer circle of the winding core 3 can be welded to the first plate body 21 of the cover plate 2, thereby reducing the internal resistance of the battery and increasing the battery power.

[0069] Preferably, if Figure 3 As shown, the minimum distance L from the center point A of the second plate body 22 of the cover plate 2 of the present invention to the sub-plate body 211 is not less than 5.0 mm.

[0070] The cover plate 2 of the present invention can ensure that the explosion-proof valve has a sufficient valve opening area by setting the minimum distance from the center point A of the second plate body 22 to the sub-plate body 211 to be no less than 5.0 mm, thereby improving the safety of the battery.

[0071] like Figure 3 As shown, the straight-line distance between the center point A of the second plate body 22 and the vertex O of the sub-plate body 211 is the minimum distance L, where L≥5.0mm. For example, technicians in this field can set the distance L to 5.0mm, 8.0mm or 10.0mm, etc. in actual applications. Those skilled in the art can flexibly set it according to actual conditions.

[0072] Preferably, if Figure 1 and Figure 2 As shown, the cover plate 2 of the present invention is provided with a liquid injection hole 24 on the second plate body 22 , and the liquid injection hole 24 is located at the center of the cover plate 2 .

[0073] The electrolyte can be injected into the battery housing 1 through the injection hole 24. The cover plate 2 of the present invention is arranged at the center of the cover plate 2 through the injection hole 24. Figure 1 As shown, after the battery is assembled, the injection hole 24 on the cover plate 2 is aligned with the central hole 32 of the winding core 3. When the electrolyte is added through the injection hole 24, the electrolyte can be directly injected into the battery through the central hole 32 of the winding core 3, which is beneficial to improving the injection efficiency of the electrolyte.

[0074] Preferably, if Figure 1 and Figure 2 As shown, the outer surface of the cover plate 2 of the present invention is provided with a positioning groove 25 recessed toward the inner surface of the cover plate 2 at a position corresponding to the injection hole 24 , and the positioning groove 25 is used to accommodate a sealing pin for sealing the injection hole 24 .

[0075] The cover plate 2 of the present invention is provided with a sealing nail positioning groove 25 on the outer surface for accommodating the sealing injection hole 24 , thereby improving the connection stability between the sealing nail and the cover plate 2 and improving the sealing performance of the injection hole 24 .

[0076] After the battery core 3 is installed into the battery shell 1, electrolyte is added to the battery shell 1 through the injection hole 24 on the cover plate 2. After the electrolyte is added, the sealing pin is installed into the positioning groove 25. The size of the positioning groove 25 matches the size of the sealing pin. Then, the sealing pin is welded to the shell 1 to seal the injection hole 24.

[0077] Those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims of the present application, any one of the claimed embodiments may be used in any combination.

[0078] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A cover plate for a cylindrical battery, characterized in that: The cover plate includes a first plate body and a second plate body, the first plate body is higher than the second plate body, the first plate body is used to support the winding core of the cylindrical battery, and the second plate body is provided with an explosion-proof valve.

2. The cover plate according to claim 1, characterized in that: The second plate body includes a plurality of strip plates extending in a radial direction of the cover plate, and the plurality of strip plates are distributed at intervals in a circumferential direction of the cover plate.

3. The cover plate according to claim 2, characterized in that: The explosion-proof valve is formed as an explosion-proof valve notch provided along the edge of the strip plate.

4. The cover plate according to claim 2, characterized in that: The first plate body includes a plurality of sub-plate bodies, and the plurality of sub-plate bodies are distributed at intervals along the circumference of the cover plate, and two adjacent sub-plate bodies are separated by the strip plate.

5. The cover plate according to claim 4, characterized in that: The sub-plate body is arranged in a fan shape.

6. The cover plate according to claim 5, characterized in that: The minimum distance from the center point of the second plate body to the sub-plate body is not less than 5.0 mm.

7. The cover plate according to claim 5, characterized in that: The second plate body is provided with a liquid injection hole, and the liquid injection hole is located at the center of the cover plate.

8. The cover plate according to claim 7, characterized in that: The outer surface of the cover plate is provided with a positioning groove at a position corresponding to the liquid injection hole.

9. The cover plate according to any one of claims 1 to 8, characterized in that: A height difference between the first plate body and the second plate body is no more than 2.0 mm.

10. A cylindrical battery, characterized in that: It comprises the cover plate according to any one of claims 1 to 9; a shell, one side of which has an opening, and the cover plate is arranged at the opening; a winding core, which is arranged on the shell; wherein the first plate body is electrically connected to the negative electrode of the winding core.

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