Top cover, cap assembly and battery

Abstract

The application provides a top cover, a cap assembly and a battery. The top cover comprises a supporting outer ring, a plurality of gable connecting pieces and an outer connecting welding piece connected in sequence, the number of the gable connecting pieces is at least two, and a pressure relief channel for pressure relief is formed between each two adjacent gable connecting pieces; a plane where the supporting outer ring is located is defined as a gable reference plane, each gable connecting piece comprises a vertical extension part and a gable extension part, the gable extension part is connected to the vertical extension part and the outer connecting welding piece respectively, one end of the vertical extension part away from the gable extension part is connected to the supporting outer ring, a gable is formed between the surface extension direction of the end of the vertical extension part connected to the gable extension part and the gable reference plane, the degree of the gable is 40°-79°, the inclination angle of each gable connecting piece relative to the supporting outer ring is large, the top cover has good compression deformation resistance, and the compression residual deformation of the top cover is small compared with the cap assembly of the traditional battery.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a top cover, a cap assembly, and a battery. Background Technology

[0002] The cap assembly includes an explosion-proof valve, a rubber ring, a pressure relief plate, a top cover, and an outer plastic part. The rubber ring surrounds the periphery of the explosion-proof valve, which is welded to one side of the pressure relief plate. The other side of the pressure relief plate covers the periphery of the top cover, and the outer plastic part covers the periphery where the pressure relief plate connects to the top cover. The explosion-proof valve, welded to the electrode tab, functions as a circuit breaker. When the pressure inside the cell rises to a predetermined value, the explosion-proof valve deforms to cut off the current circuit. When the pressure inside the cell rises further, the explosion-proof valve structure is destroyed, releasing the internal pressure of the battery to prevent explosion. It also separates from the pressure relief plate when the internal pressure of the cell reaches a threshold. Simultaneously, the pressure relief plate deforms away from the explosion-proof valve and may even crack, allowing the pressure inside the cell to be released. When the pressure relief plate cracks, the pressure inside the cell is released sequentially through the pressure relief plate and the pressure relief holes in the top cover.

[0003] During PACK assembly, the cap assembly is prone to deformation due to lateral pressure. This deformation can lead to loss or weakening of the pressure relief function. Often, both the cap and the pressure relief plate deform simultaneously during assembly, as the internal pressure of the battery cell needs to be released through the pressure relief vent on the cap. Therefore, after battery assembly, especially during subsequent use, it is crucial to ensure reliable and effective pressure relief through the pressure relief vent, while simultaneously ensuring the flatness of the top of the cap meets predetermined standards.

[0004] The top cover includes a boss and an annular perimeter surrounding the boss. The part of the boss that connects to the annular perimeter has a conical structure, giving the top cover a frustum-shaped structure. The pressure relief plate covers and connects to the annular perimeter. The overall structure of the top cover has the characteristics of "small at the top and large at the bottom". This not only facilitates effective welding during PACK assembly, but also benefits the stamping and forming of the top cover.

[0005] However, considering that the reliability of the cap assembly is affected by lateral deformation during the assembly process, it is very important to comprehensively solve the relationship between the dimensional parameters of the top cover to deal with the problem of lateral deformation, especially for miniaturized batteries, such as small batteries, which are limited by the design of miniaturized batteries with less material and thinner design. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a top cover, cap assembly and battery with better resistance to lateral deformation and higher reliability.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A top cover includes a supporting outer ring, a beveled connecting piece, and an external welding piece connected in sequence, wherein the number of beveled connecting pieces is at least two, and a pressure relief channel for pressure relief is formed between each two adjacent beveled connecting pieces.

[0009] The plane containing the outer supporting ring is defined as the slope angle reference plane. Each slope angle connecting piece includes a vertical extension and a slope angle extension. The slope angle extension is connected to the vertical extension and the external welding piece, respectively. The end of the vertical extension away from the slope angle extension is connected to the outer supporting ring. The extension direction of the vertical extension is perpendicular to the slope angle reference plane. The surface extension direction of the end of the slope angle extension connected to the vertical extension forms a slope angle with the slope angle reference plane. The degree of the slope angle is 40° to 79°.

[0010] In one embodiment, the portion where the vertical extension connects to the supporting outer ring has a first transition fillet.

[0011] In one embodiment, the portions of the slope extension that are connected to the vertical extension and the external welding piece respectively are each formed with a second transition fillet.

[0012] In one embodiment, the radius of the second transition fillet is 0.2 mm to 1 mm.

[0013] In one embodiment, the radius of the second transition fillet is 0.2 mm to 0.3 mm.

[0014] In one embodiment, the slope angle is 60° to 75°.

[0015] In one embodiment, the number of the beveled connecting pieces is multiple.

[0016] In one embodiment, the supporting outer ring is arranged parallel to the outer welding piece, and the distance between the supporting outer ring and the outer welding piece is 0.5mm to 6mm.

[0017] In one embodiment, the top cover is a one-piece molded structure.

[0018] A cap assembly comprising the top cover as described in any of the above embodiments.

[0019] A battery comprising the aforementioned cap assembly.

[0020] In one embodiment, the battery is a cylindrical battery.

[0021] Compared with the prior art, the present invention has at least the following advantages:

[0022] The aforementioned top cover, because each beveled connecting piece includes a vertical extension and a beveled extension, with the beveled extension connected to the vertical extension and the external welding piece respectively, and the end of the vertical extension away from the beveled extension connected to the supporting outer ring, and the surface extension direction of the end of the beveled extension connected to the vertical extension forming a bevel angle with the bevel reference surface, the bevel angle being 40° to 79°, makes the tilt angle of each beveled connecting piece relative to the supporting outer ring relatively small, so that the top cover has better compressive deformation resistance when subjected to lateral pressure. Compared with the traditional battery cap assembly, the top cover has a larger residual deformation under pressure, so that the top cover has better compressive strength and improves the reliability of the top cover. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the top cover of one embodiment;

[0025] Figure 2 for Figure 1 A cross-sectional view of the top cover shown;

[0026] Figure 3 for Figure 1 The diagram shows the deformation of the top cover under lateral pressure.

[0027] Figure 4 for Figure 1 The diagram shows another deformation of the top cover under lateral pressure.

[0028] Figure 5 The curve distribution of the residual compressive deformation of the roof under different lateral pressures at different slope angles;

[0029] Figure 6 A curve distribution diagram showing the residual compressive deformation of the top cover at different distances under different lateral pressures;

[0030] Figure 7 The curve distribution of the residual compressive deformation of top covers made of different materials under different pressure conditions;

[0031] Figure 8 This is a schematic diagram of a cap assembly according to one embodiment. Detailed Implementation

[0032] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0033] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] This application provides a top cover, including a supporting outer ring, a beveled connecting piece, and an external welding piece connected in sequence. The number of beveled connecting pieces is at least two, and a pressure relief channel for pressure relief is formed between each two adjacent beveled connecting pieces. The plane where the supporting outer ring is located is defined as the beveled reference plane. Each beveled connecting piece includes a vertical extension and a beveled extension. The beveled extension is connected to the vertical extension and the external welding piece, respectively. The end of the vertical extension away from the beveled extension is connected to the supporting outer ring. The extension direction of the vertical extension is perpendicular to the beveled reference plane. The surface extension direction of the beveled extension connected to the end of the vertical extension forms a bevel angle with the beveled reference plane. The degree of the bevel angle is 40° to 79°.

[0036] The aforementioned top cover, because each beveled connecting piece includes a vertical extension and a beveled extension, with the beveled extension connected to the vertical extension and the outer welding piece respectively, and the end of the vertical extension away from the beveled extension connected to the supporting outer ring, and the surface extension direction of the end of the beveled extension connected to the vertical extension forming a bevel angle with the bevel reference surface, the bevel angle being 40° to 79°, makes the tilt angle of each beveled connecting piece relative to the supporting outer ring relatively large, giving the top cover better compressive deformation resistance. Compared with traditional battery cap assemblies, the top cover has a larger residual compressive deformation, improving the reliability of the top cover.

[0037] To better understand the technical solution and beneficial effects of this application, the following detailed description is provided in conjunction with specific embodiments:

[0038] like Figure 1 and Figure 2 As shown, in one embodiment, the top cover 100 includes a supporting outer ring 110, a beveled connecting piece 120, and an external welding piece 130 connected in sequence, such that the beveled connecting piece 120 serves to connect to the supporting outer ring 110 and the external welding piece 130 respectively. The number of beveled connecting pieces 120 is at least two, and a pressure relief channel 122 for pressure relief is formed between each pair of adjacent beveled connecting pieces 120. The plane containing the supporting outer ring 110 is defined as the beveled reference plane a.

[0039] like Figure 1 and Figure 2 As shown, in one embodiment, each beveled connecting piece 120 includes a vertical extension 123 and a beveled extension 125. The beveled extension 125 is connected to both the vertical extension 123 and the external welding piece 130. The end of the vertical extension 123 away from the beveled extension 125 is connected to the supporting outer ring 110. The extending direction of the vertical extension 123 is perpendicular to the beveled reference surface. A bevel angle θ is formed between the surface extending direction of the beveled extension 125 connected to the end of the vertical extension 123 and the beveled reference surface. The bevel angle θ is between 40° and 79°.

[0040] The aforementioned top cover 100, since each beveled connecting piece 120 includes a vertical extension 123 and a beveled extension 125, the beveled extension 125 is connected to the vertical extension 123 and the external welding piece respectively, and the end of the vertical extension 123 away from the beveled extension 125 is connected to the supporting outer ring, the surface extension direction of the beveled extension 125 connected to the end of the vertical extension 123 forms a bevel angle with the beveled reference surface, the bevel angle θ is 40° to 79°, so that the tilt angle of each beveled connecting piece 120 relative to the supporting outer ring 110 is small, so that the top cover 100 has better compressive deformation resistance when subjected to lateral pressure. Compared with the traditional battery cap assembly, the top cover 100 has a larger residual deformation under pressure, so that the top cover 100 has better compressive strength and improves the reliability of the top cover. It is understood that, in one embodiment, under the same compressive strength requirements, the structure of the top cover is thinner and lighter, making the top cover more suitable for miniaturized batteries with less material used in the design.

[0041] It should be noted that, as Figure 3 or Figure 4As shown, the residual compressive deformation is the deformation of the top cover under lateral pressure. The diameter of the top cover before deformation is defined as the initial diameter D1, and the diameter after deformation is defined as the stop diameter D2. Therefore, the stop diameter D2 is the residual compressive deformation, and it is smaller than the initial diameter D1. It can be understood that the larger the residual compressive deformation, the better the compressive deformation performance of the top cover 100, i.e., the better the compressive strength of the top cover 100.

[0042] To better illustrate the compressive deformation resistance of the top cover 100, the residual compressive deformation was tested under different lateral pressure conditions, namely, lateral pressures of 1KN, 3KN, and 5KN. The initial diameter D1 of the top cover in this application is equal to that of the conventional top cover, both being 8.76mm. The slope angles θ of the conventional top cover 100 are 80° (Comparative Example 1) and 89° (Comparative Example 2), while the slope angles θ of the top cover 100 in this application are 40° (Example 1), 60° (Example 2), 70° (Example 3), and 75° (Example 4). The direction of the lateral pressure is parallel to the slope angle reference plane. Table 1 below shows the residual compressive deformation of the top cover under different lateral pressures at different slope angles. A plot of the residual compressive deformation was also obtained. Figure 5 The following is a curve showing the distribution of residual compressive deformation of the roof under different lateral pressures at different slope angles:

[0043]

[0044] Based on Table 1 above and Figure 5 Analysis shows that, under the same lateral pressure conditions, the larger the slope angle, the smaller the residual compressive deformation of the top cover 100, and the worse the corresponding compressive strength. The residual compressive deformation of the top cover in the embodiment of this application is better than that of the traditional top cover. Compared with the traditional top cover, the top cover of this application has better compressive deformation performance.

[0045] In one embodiment, the slope angle is 60° to 75°, which gives the top cover 100 better resistance to compressive deformation and, under the same initial diameter D1 of the top cover, also makes the external welding piece of the top cover 100 more conductive.

[0046] In one embodiment, the portion where the vertical extension 123 connects to the supporting outer ring has a first transition fillet, which reduces the compressive deformation stress generated by the lateral pressure on the top cover. In this embodiment, the radius of the first transition fillet is 0.1 mm to 0.2 mm.

[0047] In one embodiment, the portions of the beveled extension 125 that connect to the vertical extension 123 and the external weld plate are each formed with a second transition fillet, further reducing the compressive deformation stress generated by the lateral pressure on the top cover. In this embodiment, the radius of the second transition fillet is 0.2mm to 1mm. Specifically, the radius of the second transition fillet is 0.2mm to 0.3mm.

[0048] In one embodiment, the supporting outer ring 110 is arranged parallel to the outer welding piece 130 to allow the top cover 100 to be better stamped.

[0049] In one embodiment, the distance between the supporting outer ring 110 and the external welding piece 130 is 0.5mm to 6mm. In this embodiment, the distance between the supporting outer ring 110 and the external welding piece 130 is 2mm to 4mm, which gives the top cover 100 better compressive deformation resistance. Compared with traditional top covers, the above-mentioned top cover 100 has a larger residual compressive deformation.

[0050] To better illustrate the different residual deformation of the top cover under different lateral pressures at different distances, the distances between the supporting outer ring 110 and the external welding piece 130 were further set to 0.5mm, 1mm, 2mm, 4mm, and 6mm, respectively, and the slope angle of the top cover was set to 70° for all of them. Under lateral pressures of 1KN, 3KN, 5KN, and 13KN, the residual deformation of the top cover 100 under different lateral pressures at different distances was obtained as shown in Table 2 below. A plot of the residual deformation was also obtained. Figure 6 The following is a curve showing the distribution of residual compressive deformation of the top cover 100 at different distances under different lateral pressures:

[0051]

[0052] Based on Table 2 above and Figure 6 Analysis shows that as the distance between the outer supporting ring 110 and the outer welding piece 130 increases, the residual compressive deformation of the top cover 100 is worse under the same slope angle, that is, the compressive deformation performance of the cap assembly is worse.

[0053] Furthermore, the top cover 100 is an SPCC (Steel Plate Cold Rolled Commercial) nickel-plated cover, an iron nickel-plated cover, a zinc nickel-plated cover, or a pure nickel cover. To better illustrate the relationship between the compressive deformation resistance of the top cover 100 and its material, the top cover 100 is an SPCC nickel-plated cover, an iron nickel-plated cover, a zinc nickel-plated cover, or a pure nickel cover, with a slope angle of 70°. Under lateral pressures of 1KN, 3KN, 5KN, and 7KN, the residual compressive deformation of the top cover 100 is different. Table 3 below shows the data on the residual compressive deformation of the top cover 100 of different materials under different lateral pressure conditions, and the plotted data based on Table 3 is shown in Table 3. Figure 7 The graph shows the residual deformation under different pressure conditions for top covers 100 made of different materials.

[0054]

[0055] According to Table 3 above and Figure 7 Analysis shows that under different lateral pressure conditions, the top cover 100 has the best residual deformation under pressure when it is made of pure nickel; followed by nickel-plated iron, nickel-plated zinc, and pure nickel.

[0056] like Figure 1 and Figure 2 As shown, in one embodiment, the number of the beveled connecting pieces 120 is multiple, giving the top cover 100 a better venting and pressure relief effect. In this embodiment, the number of beveled connecting pieces 120 is three, four, or some other number.

[0057] Furthermore, there are multiple beveled connecting pieces, and a pressure relief channel is formed between each pair of adjacent beveled connecting pieces for pressure relief. In this embodiment, the two ends of each pair of adjacent beveled connecting pieces are connected as one unit, and each pressure relief channel is formed at the middle position of the two adjacent beveled connecting pieces. Multiple beveled connecting pieces together form a beveled connection structure.

[0058] Furthermore, the total area of ​​the projection of the slope angle connection structure onto the plane where the slope angle reference surface is located is S1, and the total area of ​​the projection of the pressure relief channel onto the plane where the slope angle reference surface is located is S2. The area ratio of the pressure relief channel is S2 / S1, and S2 / S1 is 0.1% to 30%, which gives the top cover better compressive deformation resistance and thus better compressive strength.

[0059] To better illustrate the influence of S2 / S1 on the compressive deformation performance of the top cover, the residual compressive deformation of the top cover of this application was tested under different lateral pressures. D1 was 8.76 mm, and the slope angle was 70°. The area ratio of the pressure relief channel of the top cover of this application was 3% (Example 1), 7% (Example 2), 8% (Example 3), 12% (Example 4), and 30% (Example 5), respectively. Tests were conducted under lateral pressures of 1 KN, 3 KN, 5 KN, and 13 KN, and the data in Table 4 below, showing the residual compressive deformation data generated by the area ratio of the pressure relief channel under different lateral pressures, are presented below.

[0060]

[0061] According to the data in Table 4, under the same slope angle, the smaller the area ratio of the pressure relief channel of the top cover, the greater the residual deformation of the top cover under pressure, that is, the higher the compressive strength of the top cover. In this embodiment, S2 / S1 is 3% to 12%. Preferably, S2 / S1 is 7% to 8%, which makes the compressive strength of the top cover better, and at the same time makes the top cover have a better pressure relief effect.

[0062] like Figure 2 As shown, in one embodiment, the slope extension 125 of each slope connecting piece 120 includes a first rounded transition curved surface 120a, a supporting curved surface 120b, and a second rounded transition curved surface 120c connected in sequence. The first rounded transition curved surface 120a is connected to the supporting outer ring 110, and the second rounded transition curved surface 120c is connected to the external welding piece 130, so that each slope connecting piece 120 is well connected to the supporting outer ring 110 and the external welding piece 130 respectively, while reducing the compressive stress generated in each slope connecting piece 120. In this embodiment, the slope angle is the maximum angle between the tangent plane of the supporting curved surface 120b and the slope angle reference plane. Furthermore, the first rounded corner transition curved surface 120a, the supporting curved surface 120b, and the second rounded corner transition curved surface 120c are integrally formed structures, making the structure of each of the slope connecting pieces 120 more compact, while ensuring that the first rounded corner transition curved surface 120a, the supporting curved surface 120b, and the second rounded corner transition curved surface 120c are firmly connected.

[0063] like Figure 1 and Figure 2 As shown, in one embodiment, the top cover 100 is a one-piece molded structure, making the structure of the top cover 100 more compact, while firmly connecting the supporting outer ring 110, the beveled connecting piece 120, and the external welding piece 130. In this embodiment, the top cover 100 is a one-piece stamped structure.

[0064] like Figure 1 and Figure 8 As shown, this application also provides a cap assembly 10, including the top cover 100 described in any of the above embodiments. Further, the top cover 100 includes a supporting outer ring 110, a beveled connecting piece 120, and an external welding piece 130 connected in sequence, such that the beveled connecting piece 120 serves to connect to the supporting outer ring 110 and the external welding piece 130 respectively. The number of beveled connecting pieces 120 is at least two, and a pressure relief channel 122 for pressure relief is formed between each pair of adjacent beveled connecting pieces 120. The plane containing the supporting outer ring 110 is defined as the beveled reference plane a.

[0065] In one embodiment, each beveled connecting piece 120 includes a vertical extension 123 and a beveled extension 125. The beveled extension 125 is connected to both the vertical extension 123 and an external welding piece. The end of the vertical extension 123 away from the beveled extension 125 is connected to a supporting outer ring. The extending direction of the vertical extension 123 is perpendicular to the beveled reference surface. A bevel angle θ is formed between the surface extending direction of the beveled extension 125 connected to the end of the vertical extension 123 and the beveled reference surface. The bevel angle θ is between 40° and 79°.

[0066] The cap assembly 10 described above, since each beveled connecting piece 120 includes a vertical extension 123 and a beveled extension 125, the beveled extension 125 is connected to the vertical extension 123 and the external welding piece respectively, the end of the vertical extension 123 away from the beveled extension 125 is connected to the supporting outer ring, the surface extension direction of the beveled extension 125 connected to the end of the vertical extension 123 forms a bevel angle with the beveled reference surface, the bevel angle θ is 40° to 79°, so that the tilt angle of each beveled connecting piece 120 relative to the supporting outer ring 110 is small, so that the top cover 100 has better compressive deformation resistance when subjected to lateral pressure. Compared with the cap assembly of traditional batteries, the top cover 100 has a larger residual deformation under pressure, thus making the cap assembly 10 have better compressive strength.

[0067] like Figure 1 and Figure 8As shown, the cap assembly 10 further includes an explosion-proof valve 200, an outer plastic part 300, a pressure relief plate 400, and a sealing ring 500. The explosion-proof valve 200 is connected to the outer periphery of the supporting outer ring 110. The top cover 100 has a deformable groove 202 connected to the pressure relief channel 122 on the side adjacent to the explosion-proof valve 200. The outer plastic part 300 is plastic-coated around the outer periphery of the explosion-proof valve 200 and the periphery of the supporting outer ring 110, thus sealing the outer plastic part 300 to both the explosion-proof valve 200 and the supporting outer ring 110. The explosion-proof valve 200 is welded to the pressure relief plate 400 on the side opposite to the top cover 100. A sealing ring 500 is plastic-coated around the outer periphery of the pressure relief plate 400, and the sealing ring 500 elastically abuts against the side of the top cover 100 opposite to the explosion-proof valve 200, forming a pressure relief groove 204 between the sealing ring 500, the pressure relief plate 400, and the explosion-proof valve 200. In this embodiment, the outer peripheral wall of the outer plastic part 300 is insulated and sealed to the inner peripheral wall of the housing (not shown), thus insulating the housing from the cap assembly 10.

[0068] like Figure 8 As shown, the explosion-proof valve 200 further includes an explosion-proof valve body 210 and a covering and fixing part 220 extending outward from the explosion-proof valve body. The explosion-proof valve body 210 abuts against the bottom of the supporting outer ring 110, and the covering and fixing part 220 covers the outer periphery and top of the supporting outer ring 110, respectively, so that the explosion-proof valve 200 is reliably connected to the outer periphery of the supporting outer ring 110. The explosion-proof valve body 210 is welded to the pressure relief plate 400. Further, the cap assembly 10 also includes a PTC (Positive Temperature Coefficient thermistor) (not shown). The PTC is disposed between the explosion-proof valve body 210 and the supporting outer ring 110, and the PTC abuts against the explosion-proof valve body 210 and the supporting outer ring 110 respectively. When the resistance increases suddenly, the PTC cuts off the current, which can play a temperature protection role.

[0069] like Figure 1 and Figure 8 As shown, further, the pressure relief plate 400 has an explosion-proof pressure relief hole 402 at the welding point with the explosion-proof valve 200, and the pressure relief plate 400 also has a vent hole 404 communicating with the pressure relief groove 204. When the pressure of the battery cell inside the housing reaches a first predetermined pressure value, the pressure inside the housing is greater than the pressure in the pressure relief groove 204, causing the explosion-proof valve 200 to deform upwards towards the deformation groove 202 in the direction away from the pressure relief plate 400; when the pressure of the battery cell inside the housing reaches a second predetermined pressure value, the explosion-proof valve 200 deforms upwards towards the deformation groove 202 in the direction away from the pressure relief plate 400, until the welding point between the pressure relief plate 400 and the explosion-proof valve 200 detaches, thereby disconnecting the pressure relief plate 400 from the explosion-proof valve 200 and cutting off the battery's current circuit. The first predetermined pressure value is less than the second predetermined pressure value.

[0070] When the pressure inside the battery cell reaches the third predetermined pressure value, the explosion-proof valve 200 deforms upwards toward the deformation groove 202 in the direction away from the pressure relief plate 400. The welded part between the pressure relief plate 400 and the explosion-proof valve 200 detaches, and the explosion-proof cracking area 201 of the explosion-proof valve 200 cracks. At this time, the pressure in the housing can be discharged through the vent 404, pressure relief groove 204, explosion-proof cracking area 201, deformation groove 202, and pressure relief channel 122, or through the explosion-proof pressure relief hole 402, pressure relief groove 204, explosion-proof cracking area, deformation groove 202, and pressure relief channel 122. This improves the pressure relief effect of the cap assembly 10, avoids the problem of abnormal battery explosion, and improves the safety performance of the battery. The second predetermined pressure value is less than the third predetermined pressure value.

[0071] Furthermore, the explosion-proof pressure relief hole 402 and the vent hole 404 are staggered. In this embodiment, the explosion-proof pressure relief hole 402 is located at the center of the pressure relief plate 400. The vent hole 404 is located at the periphery of the pressure relief plate 400, so that the vent hole 404 is offset from the center of the pressure relief plate 400, allowing the pressure inside the housing to enter the pressure relief groove 204 more effectively through the vent hole 404. Specifically, there are multiple vent holes 404, which are spaced apart circumferentially along the pressure relief plate 400. This gives the cap assembly 10 a better pressure relief effect and ensures that the sealing ring 500 of the cap assembly 10 is tightly connected to the pressure relief plate 400, preventing the pressure relief plate 400 from easily falling off and separating from the sealing ring 500. In other words, the periphery where the pressure relief plate 400 and the sealing ring 500 are connected acts as a buffer. In addition, the top cover has a large residual deformation under pressure, meaning that the top cover has good compressive strength, which improves the structural strength of the cap assembly 10.

[0072] This application also provides a battery (not shown) including the aforementioned cap assembly 10. In one embodiment, the battery is a cylindrical battery. Further, the battery also includes a housing and a core, with a receiving cavity formed within the housing, the core disposed within the receiving cavity, one end of the core welded to the inner peripheral wall of the housing, and the other end of the core welded to a pressure relief sheet 400. Both ends of the core are electrically connected to the housing and the cap assembly 10, respectively. The aforementioned battery, due to the use of the high-strength cap assembly 10, exhibits high overall structural strength.

[0073] Furthermore, the cylindrical battery model is 10290, 10310, 10440, 14500, or 14650. In this embodiment, the cylindrical battery is a small cylindrical battery. Due to the high structural strength of the battery, less material is used and the structure is thinner and lighter under the same structural strength requirements.

[0074] Compared with the prior art, the present invention has at least the following advantages:

[0075] The aforementioned top cover 100, since each beveled connecting piece 120 includes a vertical extension 123 and a beveled extension 125, the beveled extension 125 is connected to the vertical extension 123 and the external welding piece respectively, and the end of the vertical extension 123 away from the beveled extension 125 is connected to the supporting outer ring, the surface extension direction of the beveled extension 125 connected to the end of the vertical extension 123 forms a bevel angle with the bevel reference surface, the degree of the bevel angle is 40° to 79°, so that the tilt angle of each beveled connecting piece 120 relative to the supporting outer ring 110 is small, so that the top cover 100 has better compressive deformation resistance when subjected to lateral pressure. Compared with the traditional battery cap assembly, the top cover 100 has a larger residual deformation under pressure, so that the top cover has better compressive strength and improves the reliability of the top cover.

[0076] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A top cover, characterized in that, It includes a support outer ring, a beveled connecting piece, and an external welding piece connected in sequence. The number of beveled connecting pieces is at least two, and a pressure relief channel for pressure relief is formed between each two adjacent beveled connecting pieces. The plane containing the outer supporting ring is defined as the slope angle reference plane. Each slope angle connecting piece includes a vertical extension and a slope angle extension. The slope angle extension is connected to the vertical extension and the external welding piece, respectively. The end of the vertical extension away from the slope angle extension is connected to the outer supporting ring. The extension direction of the vertical extension is perpendicular to the slope angle reference plane. The surface extension direction of the end of the slope angle extension connected to the vertical extension forms a slope angle with the slope angle reference plane. The degree of the slope angle is 40° to 79°.

2. The top cover according to claim 1, characterized in that, The portion where the vertical extension connects to the supporting outer ring has a first transition fillet.

3. The top cover according to claim 1, characterized in that, The portions of the slope extension that connect to the vertical extension and the external welding piece respectively are all formed with a second transition rounded corner.

4. The top cover according to claim 3, characterized in that, The radius of the second transition fillet is 0.2mm to 1mm.

5. The top cover according to claim 4, characterized in that, The radius of the second transition fillet is 0.2mm to 0.3mm.

6. The top cover according to claim 1, characterized in that, The slope angle is 60° to 75°; and / or, The number of the beveled connecting pieces is multiple.

7. The top cover according to claim 1, characterized in that, The supporting outer ring is arranged parallel to the outer welding piece, and the distance between the supporting outer ring and the outer welding piece is 0.5mm to 6mm; and / or, The top cover is a one-piece molded structure.

8. A cap assembly, characterized in that, The top cover includes any one of claims 1 to 7.

9. A battery, characterized in that, Includes the cap assembly as described in claim 8.

10. The battery according to claim 9, characterized in that, The battery is a cylindrical battery.

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