Cover plate assembly and battery

Abstract

The application provides a cover plate assembly and a battery. The cover plate assembly comprises a cover, a sealing element and a limiting plate. The cover comprises a top side and a bottom side distributed along the thickness direction of the cover. The top side of the cover is provided with a mounting groove. The bottom surface of the mounting groove is provided with a through liquid injection hole. The sealing element is inserted into the liquid injection hole to seal the liquid injection hole. The limiting plate is at least partially mounted in the mounting groove. The limiting plate is located on the side of the sealing element close to the top side of the cover and is welded to the cover. One side surface of the limiting plate is provided with a groove. The groove is formed with a notch on the corresponding side surface. The minimum distance between the edge of the notch and the edge of the corresponding side surface is W. In the thickness direction of the cover, the maximum thickness of the limiting plate is D1, and 0.5D1≤W≤0.75D1. Thus, the welding stress in the limiting plate can be absorbed by the groove, the risk of excessive welding stress in the limiting plate leading to cracks at the welding seam between the limiting plate and the cover can be reduced, and the welding stability and welding strength between the limiting plate and the cover are improved.

Description

Technical Field

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

[0002] Battery cover assemblies typically have an injection hole. After electrolyte is injected into the battery through this hole, it needs to be sealed to prevent leakage. In related technologies, a sealing element is usually used to seal the injection hole, and a limiting plate is welded to the cover to limit the sealing element and provide a secondary seal for the injection hole.

[0003] However, during the welding of the limiting plate and the cover, welding stress will be generated inside the limiting plate, which can easily cause cracks at the weld between the limiting plate and the cover, affecting the welding stability of the limiting plate and the cover. Utility Model Content

[0004] The embodiments of this application provide a cover plate assembly and a battery, which can improve the technical problem that welding stress easily generated in the limit plate during the welding of the limit plate and the cover, which leads to cracks at the weld between the limit plate and the cover.

[0005] In a first aspect, embodiments of this application provide a cover plate assembly, comprising:

[0006] A cap includes a top side and a bottom side distributed along its thickness direction. The top side of the cap has an installation groove, and the bottom surface of the installation groove has a through injection hole.

[0007] A sealing element, which is inserted into the injection hole to seal the injection hole;

[0008] A limiting plate is at least partially installed in the mounting groove, the limiting plate being located on the side of the seal near the top of the cover, and is welded to the cover;

[0009] The limiting plate has a groove on one side, and the groove forms a slot on the corresponding plate surface. The minimum distance between the edge of the slot and the edge of the corresponding plate surface is W. In the thickness direction of the cover, the maximum thickness of the limiting plate is D1, where 0.5D1≤W≤0.75D1.

[0010] In some embodiments, the minimum distance W between the edge of the groove and the corresponding edge of the plate surface satisfies: W ≥ 1.25 mm. This allows the groove to effectively absorb welding stress within the limiting plate while preventing the groove from becoming too large and excessively weakening the strength of the limiting plate.

[0011] In some embodiments, the groove is a cylindrical groove extending along the thickness direction of the cover; the inner diameter of the groove is C1, wherein 1.5mm≤C1≤7mm, which enables the groove to effectively absorb the welding stress within the limiting plate while giving the limiting plate high structural strength, thus improving the welding strength and welding stability between the limiting plate and the cover; or,

[0012] The groove is an annular groove extending circumferentially along the limiting plate; the groove opening width is C2, where 0.5mm≤C1≤2mm, which enables the groove to effectively absorb the welding stress in the limiting plate while giving the limiting plate high structural strength, which is beneficial to improving the welding strength and welding stability between the limiting plate and the cover.

[0013] In some embodiments, the depth of the groove in the thickness direction of the cover is H1, wherein H1 / D1≤0.5; and / or, 0.2mm≤H1≤0.5mm. This allows the groove to effectively absorb welding stress within the limiting plate while preventing the groove depth from being too large and affecting the strength of the limiting plate.

[0014] In some embodiments, the groove is formed on the side of the limiting plate opposite to the seal; the groove is an annular groove extending circumferentially along the limiting plate, thereby enabling the groove to more effectively absorb the welding stress within the limiting plate, and at the same time, making the limiting plate stronger.

[0015] In some embodiments, the width of the groove gradually decreases from the top to the bottom of the cover. This helps to reduce the impact of creating the groove on the structural strength of the limiting plate.

[0016] In some embodiments, in the thickness direction of the cover, the thickness of the limiting plate at the groove is D2, wherein 0.2mm ≤ D2 ≤ 0.5mm. This allows the limiting plate to also have high structural strength at the groove.

[0017] In some embodiments, the side of the limiting plate facing the seal abuts against the bottom surface of the mounting groove; the depth of the mounting groove in the thickness direction of the cover is H2, where H2 ≥ D1. This allows the limiting plate to be completely contained within the mounting groove, preventing the limiting plate from protruding from the top surface of the cover and reducing the risk of damage to the limiting plate after impact.

[0018] In some embodiments, the difference between the depth H2 of the mounting groove and the maximum thickness D1 of the limiting plate is M1, where 0.1mm ≤ M1 ≤ 1mm. This prevents the limiting plate from protruding from the top surface of the cover while maximizing the thickness of the limiting plate, thereby increasing its strength.

[0019] In some embodiments, the assembly gap between the outer peripheral surface of the limiting plate and the inner peripheral surface of the mounting groove is N1, wherein 0.01mm≤N1≤0.1mm. This allows the limiting plate to be installed more easily into the mounting groove, while the mounting groove accurately positions the limiting plate, making welding between the limiting plate and the cover easier.

[0020] In some embodiments, the limiting plate and the sealing element are spaced apart; the distance between the limiting plate and the sealing element is greater than or equal to 0.2 mm and less than or equal to 0.5 mm. This creates a spring-loaded space between the limiting plate and the sealing element. When the sealing element moves a certain distance toward the top of the cover under the pressure of high-pressure gas inside the battery, the spring-loaded space provides cushioning, preventing the sealing element from directly contacting the limiting plate and causing the limiting plate to be subjected to the pushing force of the sealing element, thus affecting the welding stability between the limiting plate and the cover.

[0021] In some embodiments, the outer peripheral surface of the limiting plate is a tapered surface, and the outer diameter of the outer peripheral surface of the limiting plate gradually decreases in the direction from the top side to the bottom side of the cover; the inner peripheral surface of the mounting groove includes a tapered surface adapted to the outer peripheral surface of the limiting plate;

[0022] The difference between the cone angle of the outer circumferential surface of the limiting plate and the cone angle of the inner circumferential surface of the mounting groove is less than or equal to 10°. Therefore, by engaging the outer circumferential surface of the limiting plate with the inner circumferential surface of the mounting groove, rapid positioning of the limiting plate can be achieved, and the installation of the limiting plate can be prevented from being mistaken.

[0023] In some embodiments, the maximum thickness of the cap is H3, where D1 / H3 ≥ 0.5. This allows the limiting plate to have higher structural strength, which is beneficial for improving the limiting effect of the limiting plate on the sealing element and the secondary sealing effect on the injection hole.

[0024] Secondly, embodiments of this application provide a battery including a cover assembly as described above, the cover assembly comprising:

[0025] A cap includes a top side and a bottom side distributed along its thickness direction. The top side of the cap has an installation groove, and the bottom surface of the installation groove has a through injection hole.

[0026] A sealing element, which is inserted into the injection hole to seal the injection hole;

[0027] A limiting plate is at least partially installed in the mounting groove, the limiting plate being located on the side of the seal near the top of the cover, and is welded to the cover;

[0028] The limiting plate has a groove on one side, and the groove forms a slot on the corresponding plate surface. The minimum distance between the edge of the slot and the edge of the corresponding plate surface is W. In the thickness direction of the cover, the maximum thickness of the limiting plate is D1, where 0.5D1≤W≤0.75D1.

[0029] The beneficial effects of the embodiments of this application are as follows:

[0030] The cover assembly provided in this application provides a mounting groove on the top side of the cover and a through injection hole on the bottom surface of the mounting groove. A sealing element is inserted into the injection hole to seal it. Simultaneously, at least a portion of a limiting plate is installed within the mounting groove, positioning the limiting plate on the side of the sealing element closest to the top of the cover, and welded to the cover. This limiting plate effectively restricts the sealing element, preventing it from dislodging from the injection hole and achieving a secondary seal.

[0031] Based on this, a groove is provided on one side of the limiting plate, such that the minimum distance W between the edge of the groove and the edge of the corresponding plate surface, and the maximum thickness D1 of the limiting plate in the thickness direction of the cover, satisfy 0.5D1≤W≤0.75D1. This allows the welding stress within the limiting plate to be absorbed through the groove during welding between the limiting plate and the cover, reducing the risk of excessive welding stress and cracks at the weld between the limiting plate and the cover. This is beneficial for improving the welding stability and strength between the limiting plate and the cover. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the structure of one embodiment of the battery provided in this application;

[0034] Figure 2 A cross-sectional view of one embodiment of the cover plate assembly provided in this application;

[0035] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0036] Figure 4 This is a schematic diagram of the structure after the limiting plate and the cover are welded together, as provided in an embodiment of this application.

[0037] Figure 5A schematic diagram of the structure of one embodiment of the limiting plate provided in this application;

[0038] Figure 6 A cross-sectional view of one embodiment of the limiting plate provided in this application;

[0039] Figure 7 A partially enlarged cross-sectional view of another embodiment of the cover plate assembly provided in this application;

[0040] Figure 8 A schematic diagram of another embodiment of the limiting plate provided in this application;

[0041] Figure 9 A cross-sectional view of another embodiment of the limiting plate provided in this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1-Battery; 10-Casing; 20-Cover assembly; 21-Positive terminal; 22-Negative terminal; 23-Cap; 231-Top side; 232-Bottom side; 233-Mounting groove; 2331-First groove segment; 2332-Second groove segment; 2333-Bottom surface; 2334-Support step; 2335-Step surface; 234-Injection hole; 24-Seal; 25-Limiting plate; 251-Plate surface; 253-Weld; 255-Annular groove; 256-Groove; 30-Casing; Z-Thickness direction. Detailed Implementation

[0044] 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 a part of the embodiments of this application, and not all of the 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. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0045] This application provides a cover plate assembly and a battery. These will be described in detail below.

[0046] Figure 1 This is a schematic diagram of the structure of one embodiment of the battery provided in this application. Figure 1As shown, battery 1 includes a casing 10 and a core pack (not shown in the figure). The casing 10 includes a cover assembly 20 and a housing 30, which are connected and enclose a cavity (not shown in the figure), within which the core pack is disposed. The cover assembly 20 has a positive terminal 21 and a negative terminal 22, with the positive terminal 21 connected to the positive tab of the core pack and the negative terminal 22 connected to the negative tab of the core pack.

[0047] The cover assembly 20 is also provided with an injection hole 234, which is used to inject electrolyte into the cavity of the housing 10. After the electrolyte injection is completed, the injection hole 234 is sealed by a sealing structure to prevent electrolyte in the cavity of the housing 10 from leaking out of the injection hole 234.

[0048] like Figure 1 and Figure 2 As shown, the cover assembly 20 may include a cap 23, which is connected to the housing 30 and encloses a cavity. A positive electrode post 21 passes through the cap 23 and connects to the positive tab of the core package within the cavity. The positive electrode post 21 and the cap 23 are insulated from each other by an insulating element and remain sealed. A negative electrode post 22 passes through the cap 23 and connects to the negative tab of the core package within the cavity. The negative electrode post 22 and the cap 23 are insulated from each other by an insulating element and remain sealed. An injection port 234 is located between the positive electrode post 21 and the negative electrode post 22 and extends through the cap 23.

[0049] In some embodiments, such as Figure 3 As shown, the cover assembly 20 may include a cover 23, a seal 24, and a limiting plate 25. The cover 23 includes a top side 231 and a bottom side 232 distributed along its thickness direction Z. The top side 231 of the cover 23 has a mounting groove 233, and the bottom surface 2333 of the mounting groove 233 has a through injection hole 234. The seal 24 is inserted into the injection hole 234 to seal the injection hole 234. The limiting plate 25 is at least partially installed in the mounting groove 233. The limiting plate 25 is located on the side of the seal 24 near the top side 231 of the cover 23 and is welded to the cover 23.

[0050] Among them, such as Figure 3 and Figure 6 As shown, a groove 256 is provided on one side plate surface 251 of the limiting plate 25. The groove 256 forms a slot on the corresponding plate surface 251. The minimum distance between the edge of the slot and the edge of the corresponding plate surface 251 is W. In the thickness direction Z of the cover 23, the maximum thickness of the limiting plate 25 is D1, 0.5D1≤W≤0.75D1.

[0051] The cover plate assembly 20 provided in this application embodiment has an installation groove 233 on the top side 231 of the cover 23 and a through injection hole 234 on the bottom surface 2333 of the installation groove 233. The sealing member 24 is inserted into the injection hole 234 to seal the injection hole 234. At the same time, at least a portion of the limiting plate 25 is installed in the installation groove 233, so that the limiting plate 25 is located on the side of the sealing member 24 near the top side 231 of the cover 23 and is welded to the cover 23. This allows the limiting plate 25 to limit the sealing member 24, prevent the sealing member 24 from falling out of the injection hole 234, and achieve a secondary seal for the injection hole 234.

[0052] Based on this, a groove 256 is provided on one side surface 251 of the limiting plate 25, such that the minimum distance W between the edge of the groove 256 and the edge of the corresponding surface 251, and the maximum thickness D1 of the limiting plate 25 in the thickness direction Z of the cover 23, satisfy 0.5D1≤W≤0.75D1. This allows the welding stress within the limiting plate 25 to be absorbed through the groove 256 when the limiting plate 25 is welded to the cover 23, reducing the risk of excessive welding stress within the limiting plate 25, which could lead to cracks at the weld 253 between the limiting plate 25 and the cover 23. This is beneficial for improving the welding stability and welding strength between the limiting plate 25 and the cover 23.

[0053] It should be noted that the groove 256 can be formed on the side surface 251 of the limiting plate 25 facing the seal 24, or the groove 256 can be formed on the side of the limiting plate 25 away from the seal 24. Figure 3 As shown, when the groove 256 is opened on the side of the limiting plate 25 facing the seal 24, the minimum distance between the edge of the groove 256 on the side of the limiting plate 251 facing the seal 24 and the edge of the side of the limiting plate 25 facing the seal 24 is W.

[0054] like Figure 7 As shown, when the groove 256 is opened on the side of the limiting plate 25 away from the seal 24, the minimum distance between the edge of the groove 256 on the side of the limiting plate 251 away from the seal 24 and the edge of the plate surface 251 on the side of the limiting plate 25 away from the seal 24 is W.

[0055] In some embodiments, the seal 24 may be elastic. After the seal 24 is inserted into the injection hole 234, the seal 24 and the injection hole 234 are press-fitted together, thereby sealing the injection hole 234.

[0056] In some embodiments, such as Figure 4As shown, the edge of the limiting plate 25 can be welded to the cover 23 to further improve the connection strength between the limiting plate 25 and the cover 23. Specifically, the thickness direction Z of the limiting plate 25 is basically consistent with the thickness direction Z of the cover 23. A weld 253 is formed between the edge of the limiting plate 25 and the edge of the mounting groove 233 to weld the limiting plate 25 to the cover 23. The weld 253 extends circumferentially along the mounting groove 233 in a ring structure to further improve the welding strength between the limiting plate 25 and the cover 23, and the weld 253 can keep the edge of the limiting plate 25 and the edge of the mounting groove 233 sealed, which is beneficial to further improve the sealing effect of the injection hole 234.

[0057] In some embodiments, the minimum distance W between the edge of the groove 256 and the edge of the corresponding plate surface 251 can satisfy: W≥1.25mm. This allows the groove 256 to effectively absorb welding stress within the limiting plate 25 while preventing the groove 256 from becoming too large and excessively weakening the strength of the limiting plate 25.

[0058] The minimum distance W between the edge of the groove 256 and the edge of the corresponding plate surface 251 can be 1.3mm, 1.4mm, 1.7mm, 2mm, etc., depending on the size of the limiting plate 25.

[0059] In some embodiments, such as Figure 5 and Figure 6 As shown, the groove 256 on the limiting plate 25 can be a cylindrical groove extending along the thickness direction Z of the cover 23. The inner diameter of the groove 256 is C1, where 1.5mm≤C1≤7mm. This allows the groove 256 to effectively absorb the welding stress within the limiting plate 25 while giving the limiting plate 25 high structural strength, which is beneficial for improving the welding strength and stability between the limiting plate 25 and the cover 23.

[0060] The inner diameter C1 of the groove 256 can be 1.6mm, 1.7mm, 2mm, 3mm, 4.2mm, 5mm, 5.7mm, 6mm, etc., depending on the size of the limiting plate 25.

[0061] Or, such as Figures 7 to 9 As shown, the groove 256 on the limiting plate 25 can be an annular groove 255 extending circumferentially along the limiting plate 25. The groove width of the groove 256 is C2, where 0.5mm≤C1≤2mm. This allows the groove 256 to effectively absorb welding stress within the limiting plate 25, while also making the processing of the groove 256 easier. Furthermore, the limiting plate 25 has high structural strength, which is beneficial for improving the welding strength and stability between the limiting plate 25 and the cover 23.

[0062] The groove width C2 of the groove 256 can be 0.6mm, 0.7mm, 1mm, 1.3mm, 1.5mm, 1.7mm, 1.8mm, etc., depending on the size of the limiting plate 25.

[0063] like Figure 3 and Figure 6 As shown, in the thickness direction Z of the cover 23, the depth of the groove 256 on the limiting plate 25 is H1, where H1 / D1 ≤ 0.5, so that the groove 256 can effectively absorb the welding stress in the limiting plate 25 while avoiding the groove 256 being too deep and affecting the strength of the limiting plate 25.

[0064] The value of H1 / D1 can be 0.2, 0.25, 0.31, 0.35, 0.38, 0.42, etc., depending on the size and structure of the limiting plate 25.

[0065] In addition, the depth H of the groove 256 on the limiting plate 25 can be made to satisfy: 0.2mm ≤ H1 ≤ 0.5mm. This also allows the groove 256 to effectively absorb the welding stress within the limiting plate 25 while preventing the groove 256 from being too deep and affecting the strength of the limiting plate 25. The depth H1 of the groove 256 on the limiting plate 25 can be 0.25mm, 0.28mm, 0.32mm, 0.37mm, 0.4mm, 0.45mm, etc., depending on the size and structure of the limiting plate 25.

[0066] In some embodiments, the groove 256 may be formed on the side surface 251 of the limiting plate 25 facing away from the seal 24. The groove 256 is an annular groove 255 extending circumferentially along the limiting plate 25, thereby enabling the groove 256 to more effectively absorb the welding stress within the limiting plate 25, and at the same time, making the limiting plate 25 stronger.

[0067] Specifically, the width of the groove 256 can be gradually reduced in the direction from the top side 231 to the bottom side 232 of the cover 23. This helps to reduce the impact of the groove 256 on the structural strength of the limiting plate 25.

[0068] In some embodiments, the thickness of the limiting plate 25 at the groove 256 in the thickness direction Z of the cover 23 is D2, wherein 0.2mm≤D2≤0.5mm. This allows the limiting plate 25 to also have high structural strength at the groove 256.

[0069] The thickness D2 of the limiting plate 25 at the groove 256 can be 0.25mm, 0.28mm, 0.32mm, 0.37mm, 0.4mm, 0.45mm, etc., depending on the size and structure of the limiting plate 25.

[0070] In some embodiments, the side surface 251 of the limiting plate 25 facing the seal 24 can abut against the bottom surface 2333 of the mounting groove 233. The depth of the mounting groove 233 in the thickness direction Z of the cover 23 is H2, wherein the maximum thickness D1 of the limiting plate 25 in the thickness direction Z of the cover 23 and the depth H2 of the mounting groove 233 in the thickness direction Z of the cover 23 satisfy: H2≥D1. This allows the limiting plate 25 to be completely contained within the mounting groove 233, preventing the limiting plate 25 from protruding from the top side 231 surface of the cover 23 and reducing the risk of damage to the limiting plate 25 after impact.

[0071] The difference between the depth H2 of the mounting groove 233 and the maximum thickness D1 of the limiting plate 25 is M1, which can satisfy the condition: 0.1mm ≤ M1 ≤ 1mm. This prevents the limiting plate 25 from protruding from the top side 231 of the cover 23 while maximizing the thickness of the limiting plate 25, thus increasing its strength.

[0072] The difference M1 between the depth H2 of the mounting groove 233 and the maximum thickness D1 of the limiting plate 25 can be 0.15mm, 0.18mm, 0.22mm, 0.37mm, 0.4mm, 0.45mm, 0.6mm, 0.8mm, etc., depending on the size and shape of the limiting plate 25 and the cover 23.

[0073] like Figure 3 As shown, the assembly gap N1 between the outer peripheral surface of the limiting plate 25 and the inner peripheral surface of the mounting groove 233 is such that N1 satisfies the following condition: 0.01mm ≤ N1 ≤ 0.1mm. This allows the limiting plate 25 to be installed more easily into the mounting groove 233, while the mounting groove 233 accurately positions the limiting plate 25, making welding between the limiting plate 25 and the cover 23 easier.

[0074] The assembly gap N1 between the outer peripheral surface of the limiting plate 25 and the inner peripheral surface of the mounting groove 233 can be 0.15mm, 0.18mm, 0.22mm, 0.37mm, 0.4mm, 0.45mm, 0.6mm, 0.8mm, etc., which can be determined according to the size and shape of the limiting plate 25 and the cover 23.

[0075] In some embodiments, the limiting plate 25 and the sealing member 24 may have a gap. The gap between the limiting plate 25 and the sealing member 24 is greater than or equal to 0.2 mm and less than or equal to 0.5 mm. This creates a spring-loaded space between the limiting plate 25 and the sealing member 24. When the sealing member 24 moves a certain distance toward the top side 231 of the cover 23 under the pressure of high-pressure gas inside the battery 1, the spring-loaded space provides cushioning, preventing the sealing member 24 from directly contacting the limiting plate 25 and causing the limiting plate 25 to be subjected to the pushing force of the sealing member 24, thereby affecting the welding stability between the limiting plate 25 and the cover 23.

[0076] The distance between the limiting plate 25 and the sealing element 24 can be 0.27mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, etc., and there is no restriction here.

[0077] In some embodiments, such as Figure 3 and Figure 6 As shown, the outer peripheral surface of the limiting plate 25 is a conical surface, and the outer diameter of the outer peripheral surface of the limiting plate 25 gradually decreases in the direction from the top side 231 to the bottom side 232 of the cover 23. The inner peripheral surface of the mounting groove 233 includes a conical surface that matches the outer peripheral surface of the limiting plate 25.

[0078] Specifically, the difference between the cone angle of the outer peripheral surface of the limiting plate 25 and the cone angle of the inner peripheral surface of the mounting groove 233 can be less than or equal to 10°. Therefore, by engaging the outer peripheral surface of the limiting plate 25 with the inner peripheral surface of the mounting groove 233, rapid positioning of the limiting plate 25 can be achieved, and the installation of the limiting plate 25 can be prevented from going wrong.

[0079] It should be noted that the cone angle of the outer peripheral surface of the limiting plate 25 can be greater than the cone angle of the inner peripheral surface of the mounting groove 233, or the cone angle of the outer peripheral surface of the limiting plate 25 can be smaller than the cone angle of the inner peripheral surface of the mounting groove 233, or the cone angle of the outer peripheral surface of the limiting plate 25 can be equal to the cone angle of the inner peripheral surface of the mounting groove 233. Furthermore, the difference between the cone angle of the outer peripheral surface of the limiting plate 25 and the cone angle of the inner peripheral surface of the mounting groove 233 can be 9°, 7°, 6°, 5.5°, 4°, 2°, 0°, etc., and is not limited here.

[0080] In some embodiments, the cone angle of the outer peripheral surface of the limiting plate 25 can be greater than or equal to 10° and less than or equal to 90°, so that the outer peripheral surface of the limiting plate 25 has a better guiding effect, enabling the limiting plate 25 to be quickly and accurately installed into the mounting groove 233. The cone angle of the outer peripheral surface of the limiting plate 25 can be 20°, 30°, 45°, 70°, 80°, etc., and is not limited here.

[0081] In some embodiments, the cone angle of the inner circumferential surface of the mounting groove 233 may be greater than or equal to 10° and less than or equal to 90°, so that the inner circumferential surface of the mounting groove 233 has a better guiding effect on the limiting plate 25, enabling the limiting plate 25 to be quickly and accurately installed into the mounting groove 233. The cone angle of the inner circumferential surface of the mounting groove 233 may be 20°, 30°, 45°, 70°, 80°, etc., and is not limited here.

[0082] In some embodiments, such as Figure 3 As shown, the maximum thickness of the cap 23 is H3. The maximum thickness H3 of the cap 23 can be such that the maximum thickness D1 of the limiting plate 25 in the thickness direction Z of the cap 23 satisfies: D1 / H3 ≥ 0.5. This allows the limiting plate 25 to have higher structural strength, which is beneficial for improving the limiting effect of the limiting plate 25 on the sealing element 24, as well as the secondary sealing effect on the injection hole 234.

[0083] In some embodiments, the side of the limiting plate 25 facing away from the seal 24, surface 251, is a circular or annular surface. The outer diameter of this side of the limiting plate 25 facing away from the seal 24 is A1, which can satisfy the following condition: 4.5mm ≤ A1 ≤ 10mm. This allows for a larger outer diameter of the limiting plate 25, providing sufficient welding space when the edge of the limiting plate 25 is welded to the cover 23, thus improving the welding quality between the limiting plate 25 and the cover 23. The outer diameter A1 of the side of the limiting plate 25 facing away from the seal 24 can be 5mm, 6.5mm, 7mm, 8mm, 9mm, etc., and is not limited here.

[0084] In some embodiments, such as Figure 3 As shown, the side surface 251 of the limiting plate 25 facing the sealing element 24 is circular or annular. The outer diameter of the side surface 251 of the limiting plate 25 facing the sealing element 24 is B1, which can satisfy: 4mm ≤ B1 ≤ 9mm. This allows the limiting plate 25 to have a larger size, facilitating welding the limiting plate 25 to the cover 23. The outer diameter B1 of the side surface 251 of the limiting plate 25 facing the sealing element 24 can be 5mm, 6.5mm, 7mm, 8mm, etc., and is not limited here.

[0085] In some embodiments, the maximum thickness D1 of the limiting plate 25 can satisfy: 0.4mm ≤ D1 ≤ 1mm. This allows the limiting plate 25 to have high structural strength. The maximum thickness D1 of the limiting plate 25 can be 0.5mm, 0.65mm, 0.7mm, 0.8mm, 0.9mm, etc., and is not limited here.

[0086] In some embodiments, the groove 233 forms a circular opening on the top side 231 of the cover 23. The inner diameter of the groove 233 on the top side 231 of the cover 23 is A2, wherein the inner diameter A2 of the groove 233 on the top side 231 of the cover 23 can satisfy: 4.5mm ≤ A2 ≤ 10mm. This allows the groove 233 to have a larger opening size, facilitating the quick and accurate installation of the limiting plate 25 into the groove 233. The inner diameter A2 of the groove 233 on the top side 231 of the cover 23 can be 5mm, 6.5mm, 7mm, 8mm, 9mm, etc., and is not limited here.

[0087] In some embodiments, such as Figure 7 As shown, a support step 2334 can be protruding from the bottom surface 2333 of the mounting groove 233, surrounding the injection hole 234. One side plate 251 of the limiting plate 25 is supported by the support step 2334. By having the support step 2334 support one side plate 251 of the limiting plate 25, the limiting plate 25 can be positioned, keeping the position of the limiting plate 25 relative to the cover 23 and the seal 24 stable. This helps to improve the welding stability between the limiting plate 25 and the cover 23, and keeps the distance between the limiting plate 25 and the seal 24 stable.

[0088] The supporting step 2334 extends circumferentially along the injection hole 234. The supporting step 2334 has a ring structure. The mounting groove 233 includes a first groove segment 2331 and a second groove segment 2332 connected sequentially along the thickness direction Z of the cover 23. The first groove segment 2331 is located between the second groove segment 2332 and the injection hole 234. The bottom surface 2333 of the mounting groove 233 is located at the end of the first groove segment 2331 near the injection hole 234. The first groove segment 2331 is located within the supporting step 2334. The second groove segment 2332 is located on the side of the supporting step 2334 near the top side 231 of the cover 23. A portion of the seal 24 is located within the injection hole 234. When the air pressure inside the battery 1 is too high, the seal 24 can be pushed into the first groove segment 2331 by the air pressure to buffer the seal 24 and prevent the seal 24 from directly contacting the limiting plate 25. At least a portion of the limiting plate 25 is located within the second groove section 2332, and one side plate surface 251 of the limiting plate 25 abuts against the step surface 2335 of the supporting step 2334 near the top side 231 of the cover 23.

[0089] In some embodiments, the support step 2334 is an annular structure. The inner diameter of the support step 2334 is A3, where 2mm ≤ A3 ≤ 8mm. This allows the support step 2334 to have a larger inner diameter, making it less likely to obstruct the seal 24 and facilitating the rebound of the seal 24. The inner diameter A3 of the support step 2334 can be 2mm, 3.5mm, 5mm, 6mm, 7mm, etc., and is not limited here.

[0090] This application also provides a battery, which includes a cover assembly. The specific structure of the cover assembly is as described in the above embodiments. Since this battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0091] Among them, such as Figure 1 As shown, battery 1 includes a casing 10 and a core pack (not shown in the figure). The casing 10 includes a cover assembly 20 and a housing 30, which are connected and enclose a cavity (not shown in the figure), within which the core pack is disposed. The structure of the cover assembly 20 can refer to the above embodiments and will not be repeated here. The structure of the core pack can be an existing structure including a core, a positive electrode tab, and a negative electrode tab, and is not limited here.

[0092] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A cover plate assembly, characterized in that, include: A cap includes a top side and a bottom side distributed along its thickness direction. The top side of the cap has an installation groove, and the bottom surface of the installation groove has a through injection hole. A sealing element, which is inserted into the injection hole to seal the injection hole; A limiting plate is at least partially installed in the mounting groove, the limiting plate being located on the side of the seal near the top of the cover, and is welded to the cover; The limiting plate has a groove on one side, and the groove forms a slot on the corresponding plate surface. The minimum distance between the edge of the slot and the edge of the corresponding plate surface is W. In the thickness direction of the cover, the maximum thickness of the limiting plate is D1, where 0.5D1≤W≤0.75D1.

2. The cover plate assembly as claimed in claim 1, characterized in that, The minimum distance W between the edge of the slot and the corresponding edge of the plate surface satisfies: W≥1.25mm.

3. The cover plate assembly as claimed in claim 1, characterized in that, The groove is a cylindrical groove extending along the thickness direction of the cover; the inner diameter of the groove is C1, where 1.5mm ≤ C1 ≤ 7mm; or, The groove is an annular groove extending circumferentially along the limiting plate; the groove opening width is C2, wherein 0.5mm≤C1≤2mm.

4. The cover plate assembly as claimed in claim 1, characterized in that, In the thickness direction of the cap, the depth of the groove is H1, wherein H1 / D1≤0.5; and / or, 0.2mm≤H1≤0.5mm.

5. The cover plate assembly as claimed in claim 1, characterized in that, The groove is formed on the side of the limiting plate opposite to the sealing element; the groove is an annular groove extending circumferentially along the limiting plate.

6. The cover plate assembly as claimed in claim 5, characterized in that, The width of the groove gradually decreases from the top side to the bottom side of the cover.

7. The cover plate assembly as claimed in claim 1, characterized in that, In the thickness direction of the cover, the thickness of the limiting plate at the groove is D2, wherein 0.2mm≤D2≤0.5mm.

8. The cover plate assembly as claimed in any one of claims 1 to 7, characterized in that, The side of the limiting plate facing the seal abuts against the bottom surface of the mounting groove; the depth of the mounting groove in the thickness direction of the cover is H2, where H2≥D1.

9. The cover plate assembly as claimed in claim 8, characterized in that, The difference between the depth H2 of the mounting groove and the maximum thickness D1 of the limiting plate is M1, where 0.1mm≤M1≤1mm.

10. The cover plate assembly as claimed in any one of claims 1 to 7, characterized in that, The assembly gap between the outer peripheral surface of the limiting plate and the inner peripheral surface of the mounting groove is N1, wherein 0.01mm≤N1≤0.1mm.

11. The cover plate assembly as claimed in any one of claims 1 to 7, characterized in that, The limiting plate and the sealing element have a gap; the gap between the limiting plate and the sealing element is greater than or equal to 0.2 mm and less than or equal to 0.5 mm.

12. The cover plate assembly as claimed in any one of claims 1 to 7, characterized in that, The outer peripheral surface of the limiting plate is a conical surface, and the outer diameter of the outer peripheral surface of the limiting plate gradually decreases in the direction from the top side to the bottom side of the cover; the inner peripheral surface of the mounting groove includes a conical surface that matches the outer peripheral surface of the limiting plate. The difference between the cone angle of the outer circumferential surface of the limiting plate and the cone angle of the inner circumferential surface of the mounting groove is less than or equal to 10°.

13. The cover plate assembly as claimed in any one of claims 1 to 7, characterized in that, The maximum thickness of the cap is H3, where D1 / H3≥0.

5.

14. A battery, characterized in that, Includes the cover plate assembly as described in any one of claims 1 to 13.

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