Secondary battery, battery pack, and electronic device

Abstract

The utility model provides a kind of secondary battery, battery pack and electronic device, secondary battery includes: shell, including end wall and side wall, end wall is provided with first assembly hole;Pole, with the cylindrical portion of first assembly hole, first limit part and second limit part are passed in;Wherein, second limit part has the first surface towards end wall, first surface and the first side surface of cylindrical portion are connected by first chamfer transition surface, and, sealing ring has second surface and second side surface, first surface presses second surface, first side surface and second side surface are opposite, second side surface and second surface are connected by second chamfer transition surface, first chamfer transition surface presses second chamfer transition surface.The utility model at least avoids: sealing ring is raised after riveting, can influence the effective sealing area of sealing ring between pole and shell, to further affect the air tightness of secondary battery, lead to abnormal performance.

Description

Technical Field

[0001] This utility model relates to a secondary battery, a battery pack, and an electronic device. Background Technology

[0002] In the field of new energy batteries, the application of secondary batteries is becoming increasingly widespread. For example, secondary batteries (such as lithium-ion batteries) can be used in electronic devices such as cars, energy storage, mobile phones, tablets, wearable devices, power banks, e-cigarettes, digital products, power tools, power devices, and energy storage devices.

[0003] The secondary battery includes a casing with terminals electrically connected to the electrode assembly. A sealing ring is used to seal the casing between the terminals and the casing. However, one radially inward end of the sealing ring is prone to warping, reducing the effective sealing area between the terminals and the casing and weakening the sealing performance. Utility Model Content

[0004] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a secondary battery, battery pack and electronic device, so as to at least avoid the sealing ring lifting after riveting, which will reduce the effective sealing area of ​​the sealing ring between the terminal and the shell, and thus affect the airtightness of the secondary battery.

[0005] To achieve the above objectives, this utility model provides a secondary battery, comprising: a casing including an end wall and a side wall surrounding the end wall, the end wall having a first mounting hole; an electrode post having a columnar portion, a first limiting portion and a second limiting portion passing through the first mounting hole, the first limiting portion and the second limiting portion being respectively connected to both ends of the columnar portion and extending towards the outer periphery of the end wall, the first limiting portion being a riveted flange; and a sealing ring disposed between the second limiting portion and the end wall and sleeved on the columnar portion; wherein the second limiting portion has a first surface facing the end wall, the first surface being connected to the first peripheral side surface of the columnar portion through a first chamfer transition surface, and the sealing ring having a second surface and a second peripheral side surface, the first surface abutting against the second surface, the first peripheral side surface being opposite to the second peripheral side surface, the second peripheral side surface being connected to the second surface through a second chamfer transition surface, the first chamfer transition surface abutting against the second chamfer transition surface.

[0006] In some embodiments, the first chamfered transition surface has a first edge that contacts the first peripheral side surface and a second edge that contacts the first surface. In the radial direction of the pole post, the first edge and the second edge are spaced apart by a length of C2 mm, and in the axial direction of the pole post, the first edge and the second edge are spaced apart by a length of C4 mm. The second chamfered transition surface has a third edge that contacts the second peripheral side surface and a fourth edge that contacts the second surface. In the free state of the sealing ring, in the radial direction of the sealing ring, the third edge and the fourth edge are spaced apart by a length of C1 mm, and in the axial direction of the sealing ring, the third edge and the fourth edge are spaced apart by a length of C3 mm; wherein C1 ≥ C2; and / or, C3 ≥ C4.

[0007] In some embodiments, 0.2 ≤ C1 ≤ 1.0, 0.2 ≤ C3 ≤ 1.0.

[0008] In some embodiments, the second chamfered transition surface has a fourth edge that contacts the second surface, and in the radially outward direction of the pole post, the fourth edge does not extend beyond the wall of the first mounting hole.

[0009] In some embodiments, the distance between the fourth edge and the wall of the first mounting hole in the radial direction of the pole post is W2 mm, and the distance between the first circumferential side of the columnar portion and the wall of the first mounting hole is W3 mm, where 0.1 ≤ W2 / W3 ≤ 0.6.

[0010] In some embodiments, the sealing ring has a first top surface facing away from the second surface. In the free state of the sealing ring, the distance between the first top surface and the second surface in the axial direction of the sealing ring is the maximum thickness W5 mm of the sealing ring. In the free state of the sealing ring, the distance between the third edge and the first top surface in the axial direction of the sealing ring is W4 mm. Wherein, 0.2×W5≤W4≤0.8×W5.

[0011] In some embodiments, the portion of the sealing ring sandwiched between the end wall and the second limiting portion has a radial width of W1 mm; in the free state, the sealing ring has a radial width of W6 mm, wherein 0.15×W6≤W1≤0.45×W6.

[0012] In some embodiments, the first chamfer transition surface is set as a rounded corner surface with a radius of R2 mm, and the second chamfer transition surface is set as a rounded corner surface with a radius of R1 mm in the free state of the sealing ring, wherein R1≥R2.

[0013] Embodiments of this application also provide a battery pack, including any of the above-described secondary batteries.

[0014] Embodiments of this application also provide an electronic device including a battery pack of any of the above.

[0015] The beneficial technical effect of this utility model is at least that it avoids the following: after riveting, the lifting of the sealing ring will affect the effective sealing area of ​​the sealing ring between the terminal and the shell, thereby affecting the airtightness of the secondary battery and causing abnormal performance. Attached Figure Description

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

[0017] Figure 1 A schematic diagram of an electronic device, using a vehicle as an example, is shown.

[0018] Figure 2 A perspective view of a secondary battery according to an embodiment of this application is shown.

[0019] Figure 3 A top view schematic diagram of a secondary battery according to an embodiment of this application is shown.

[0020] Figure 4 It shows along Figure 3 A schematic diagram of the axial cross-section of the secondary battery taken from section AA.

[0021] Figure 5 It shows Figure 4 A magnified view of a portion of region B in the middle.

[0022] Figure 6 It shows Figure 5 A magnified view of a portion of region C.

[0023] Figure 7 A top view schematic diagram of a pole according to some embodiments of this application is shown.

[0024] Figure 8 It shows Figure 7 A schematic diagram of the axial cross-section of the pole taken from the DD section.

[0025] Figure 9 A top view schematic diagram of a sealing ring according to some embodiments of this application is shown.

[0026] Figure 10 It shows Figure 9 A schematic diagram of the axial cross-section of the sealing ring taken along the EE section.

[0027] Figure 11 A top view schematic diagram of a secondary battery according to some embodiments of this application is shown.

[0028] Figure 12 It shows Figure 11 A schematic axial cross-sectional view of the secondary battery taken along the FF section.

[0029] Figure 13 It shows Figure 12 A magnified view of a portion of region G in the middle. Detailed Implementation

[0030] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0031] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0032] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0033] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0034] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0035] The secondary battery includes a casing, which comprises an end wall and side walls surrounding the end wall. A first mounting hole is provided on the end wall. During assembly, the sealing ring is first fitted onto the cylindrical portion of the terminal post, then the cylindrical portion of the terminal post is passed through the first mounting hole, and finally the terminal post is riveted to the casing. Before assembly, one end of the terminal post has a limiting portion; after riveting, the other end of the terminal post forms another limiting portion, namely the riveting flange. To easily distinguish the limiting portions at both ends of the terminal post, the riveting flange is called the first limiting portion, and the non-riveting flange is called the second limiting portion. The riveting flange can be either an internal or external riveting flange. When the riveting flange is an internal riveting flange, the sealing ring is outside the casing; when the riveting flange is an external riveting flange, the sealing ring is inside the casing.

[0036] Typically, a sealing ring is fitted onto the first circumferential sidewall of the columnar portion of the electrode post and abuts against the surface of the second limiting portion of the electrode post facing the riveting flange. This surface is continuous with the first circumferential sidewall of the columnar portion. Ideally, this surface should form a smooth right-angle transition with the first circumferential sidewall of the columnar portion, but this right-angle transition area is difficult to process. Due to the limitations of existing technology, the first circumferential sidewall of the columnar portion and the surface continuous with it are difficult to process to a flat state in the right-angle transition area; in reality, they are uneven, resulting in an uneven right-angle transition area for the electrode post. When this right-angle transition area mates with the sealing ring, the uneven portion compresses the sealing ring, and one end of the sealing ring radially inward is prone to warping. When the electrode post is riveted to form a riveting flange, the compression of the sealing ring is affected, that is, the effective sealing area between the electrode post and the casing is reduced, thereby affecting the airtightness of the cell and leading to abnormal performance of the secondary battery.

[0037] See Figure 1This utility model provides an electronic device 1000, which includes a battery pack 1002. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. As an example, the electronic device 1000 is a vehicle, which can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body, and the battery pack 1002 is located at the bottom of the vehicle body, providing electrical power for the vehicle's operation or the operation of its internal electrical components. However, in other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical power from the battery pack 1002 and perform corresponding functions, such as a fan blade rotation unit or a vacuum cleaner suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1000.

[0038] For ease of explanation, the following embodiments use a vehicle as an example to illustrate the concept of electronic device 1000. See also Figure 1 The vehicle is equipped with a battery pack 1002, which can be located at the bottom, front, or rear of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source.

[0039] Figure 2 A perspective view of a secondary battery 100 according to an embodiment of this application is shown. Figure 3 A top view schematic diagram of a secondary battery 100 according to an embodiment of this application is shown. Figure 4 It shows along Figure 3 A schematic diagram of the axial cross-section of the secondary battery taken from the AA section. For simplicity, only one side of the terminal post is shown.

[0040] In one example of the secondary battery of this utility model, see Figure 2 , Figure 3 as well as Figure 4The electrode assembly is sealed and installed within the housing 200. A first electrode tab and a second electrode tab are respectively provided at both ends of the electrode assembly in the height direction of the secondary battery 100, and the first electrode tab and the second electrode tab have opposite polarities, with the first electrode tab facing the opening side and being the negative electrode tab. It should be noted that in other embodiments, the first electrode tab can also be the positive electrode tab and the second electrode tab can be the negative electrode tab.

[0041] The electrode assembly of the secondary battery 100 is mainly formed by winding and placing positive and negative electrode sheets, and typically a first separator and a second separator are provided between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer, the positive active material layer being coated on the surface of the positive current collector; the positive current collector includes a positive electrode coating area and a positive electrode tab connected to the positive electrode coating area, the positive electrode coating area being coated with the positive active material layer, and the positive electrode tab not being coated with the positive active material layer. The negative electrode sheet includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector; the negative current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area, the negative electrode coating area being coated with the negative active material layer, and the negative electrode tab not being coated with the negative active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode current collector can be made of copper, and the negative electrode active material layer includes a negative electrode active material, which can be carbon or silicon, etc. The first and second separators can be made of PP or PE, etc. To protect and insulate the electrode assembly, an insulating film can be wrapped around the outside of the electrode assembly. The insulating film can be synthesized from PP, PE, PET, PVC, or other polymer materials.

[0042] In some embodiments, the housing 200 is made of materials such as copper, iron, aluminum, steel, or aluminum alloy, preferably steel (e.g., SPCC) for higher strength. To prevent the housing 200 from rusting during long-term use, a rust-preventive material such as metallic nickel can be plated on the surface of the housing 200. The electrode assembly is sealed and installed inside the housing 200.

[0043] Figure 5 It shows Figure 4 A magnified view of a portion of region B in the middle. Figure 6 It shows Figure 5 A magnified view of a portion of region C in the middle, for ease of explanation. Figure 6 The image shows the state of the sealing ring 400 after it has been assembled to the pole post and is compressed. See also... Figures 4 to 6The secondary battery 100 includes: a housing 200, the housing 200 including an end wall 201 and a side wall 202 surrounding the end wall 201, the end wall 201 having a first mounting hole 203. The end wall 201 can be integrally formed with the side wall 202, or the end wall 201 can be a cover plate independent of the side wall 202 and closing one end of the side wall 202. The secondary battery 100 also includes an electrode post 300, the electrode post 300 having a columnar portion 302 passing through the first mounting hole 203, a first limiting portion 301 and a second limiting portion 303. The first limiting portion 301 and the second limiting portion 303 are respectively connected to both ends of the columnar portion 302 and extend towards the outer periphery of the end wall 201, the first limiting portion 301 being a riveted flange. Although Figures 3 to 6 Taking the riveted flange as an example of an external riveted flange, this example is not limited to this. For example, the following... Figures 11 to 13 In one embodiment, the first limiting part 301 is a riveted flange, but it is located inside the housing and is an internal riveted flange.

[0044] See Figure 5 and Figure 6 As shown, the secondary battery 100 also includes a sealing ring 400, which is disposed between the second limiting portion 303 and the end wall 201 and sleeved on the columnar portion 302. The second limiting portion 303 has a first surface 600 facing the end wall 201, and the first surface 600 is connected to the first peripheral side surface 3021 of the columnar portion 302 via a first chamfered transition surface 304. The sealing ring 400 has a second surface 401 and a second peripheral side surface 403, with the first surface 600 abutting against the second surface 401, and the first peripheral side surface 3021 facing the second peripheral side surface 403. The second peripheral side surface 403 is connected to the second surface 401 via a second chamfered transition surface 402, and the first chamfered transition surface 304 abuts against the second chamfered transition surface 402. It is understandable that, compared to the interference caused by the right-angle transition area between the sealing ring 400 and the terminal post 300 in the prior art, this application avoids this interference by setting a first chamfered transition surface 304 to press against the second chamfered transition surface 402. This eliminates the problem of the sealing ring 400 lifting after the terminal post is riveted due to the interference, thereby eliminating the impact of this lifting on the airtightness of the secondary battery 200. On the one hand, the addition of the first chamfered transition surface 304 reduces the processing difficulty of the right-angle transition area; on the other hand, it reduces the possibility of the sealing ring lifting caused by unevenness of the terminal post surface due to processing.

[0045] Combination Figure 6 The second chamfered transition surface 402 of the sealing ring is further described. Preferably, the second chamfered transition surface 402 of the sealing ring has a fourth edge 4021 that contacts the second surface 401 and a third edge 4022 that contacts the second peripheral side surface 403. Figure 10 The seal is shown in its free state. See also Figure 10In the free state of the sealing ring, the distance between the third edge 4022 and the fourth edge 4021 in the radial direction S of the sealing ring 400 is C1 mm, and the distance between the third edge 4022 and the fourth edge 4021 in the axial direction I of the sealing ring 400 (in the direction of the axis M of the sealing ring) is C3 mm.

[0046] See Figure 8 The first chamfered transition surface 304 of the pole post is described. In some embodiments, the first chamfered transition surface 304 of the pole post has a first edge 3041 that contacts the first circumferential side surface 3021 and a second edge 3042 that contacts the first surface 600. In the radial direction X of the pole post, the first edge 3041 and the second edge 3042 are spaced apart by a length of C2 mm, and in the axial direction Z of the pole post (in the direction of the axis H of the pole post), the first edge 3041 and the second edge 3042 are spaced apart by a length of C4 mm.

[0047] Preferably, C1 ≥ C2; and / or, C3 ≥ C4. This arrangement ensures that the first chamfered transition surface 304 and the second chamfered transition surface 402 do not excessively compress each other when they mate, preventing the sealing ring 400 from warping more severely and reducing the adverse effects on the airtightness of the secondary battery 100. Further, in some embodiments, 0.2 ≤ C1 ≤ 1.0, 0.2 ≤ C3 ≤ 1.0. If C1 or C3 is small, for example, C1 ≤ 0.2 or C3 ≤ 0.2, it is difficult to conveniently process the second chamfered transition surface 402 with this size. If C1 or C3 is large, for example, C1 ≥ 1.0 or C3 ≥ 1.0, it is difficult to ensure the strength of the electrode post 300 and ensure that the sealing ring 400 can have a flat surface in contact with the end wall 201, thus ensuring the reliability of the compression seal of the sealing ring 400.

[0048] See Figure 6 In the radially outward direction of the electrode post, the fourth edge 4021 of the sealing ring does not extend beyond the wall of the first mounting hole 203. If the second chamfered transition surface 402 extends beyond the first mounting hole 203, the portion of the sealing ring 400 that is clamped by the second limiting part 303 and the end wall 201 and generates a large amount of compression is reduced, that is, the corresponding sealing area is reduced, affecting the airtightness of the secondary battery 100. In some embodiments, in the radial X direction of the housing 200, the distance between the fourth edge 4021 of the sealing ring and the wall of the first mounting hole 203 is W2 mm, and the distance between the first peripheral side surface 3021 of the columnar part 302 and the wall of the first mounting hole 203 is W3 mm, 0.1≤W2 / W3≤0.6. If the ratio of W2 to W3 is large, for example, W2 / W3≥0.6, it means that W2 is too large and the second chamfer transition surface 402 is difficult to process; if the ratio of W2 to W3 is small, for example, W2 / W3≤0.1, it means that W2 is too small and the extrusion pressure of the first chamfer transition surface 304 on the sealing ring 400 is likely to affect the sealing surface of the sealing ring 400.

[0049] In some embodiments, the first chamfered transition surface 304 can be configured as a rounded corner surface with a radius of R2 mm. When the sealing ring 400 is in a free state, the second chamfered transition surface 402 can also be configured as a rounded corner surface with a radius of R1 mm, where R1 ≥ R2. Although both the first chamfered transition surface 304 and the second chamfered transition surface 402 can be configured as chamfers, it is understood that rounded corners can avoid stress concentration at the corners of the pole post 300 compared to chamfers, and more effectively prevent the pole post 300 from breaking at the corners.

[0050] See also Figure 6 Taking the first limiting portion 301 as an example of an externally riveted flange, the secondary battery 100 also includes an upper plastic 101 sandwiched between the first limiting portion 301 and the end wall 201, and a lower plastic 102 sandwiched between the second limiting portion 303 and the end wall 201. The sealing ring 400 has a first portion 410 and a second portion 420 with different thicknesses, the first portion 410 being thicker than the second portion 420. The first portion 410 and the second portion 420 are continuous radially in the sealing ring 400. Compared to the columnar portion 302 of the first portion 410, which is further away from the pole post 300, the first portion 410 is pressed between the inner flange 303 and the end wall 201. A portion of the lower plastic 102 can extend into the space between the second portion 420 and the lower surface of the end wall 201. The cooperation between the sealing ring 400 and the lower plastic 102 ensures insulation between the pole post 300 and the end wall 201. Furthermore, the first portion 410 partially extends into the first mounting hole 203 and abuts against the upper plastic 101 to ensure insulation between the terminal post 300 and the hole wall of the first mounting hole 203. In one example, when assembling the secondary battery, the lower plastic 102 is inserted into the housing first, the columnar portion 302 pre-fitted with the sealing ring 400 passes through the first mounting hole 203 to press against the lower plastic 102, and the upper plastic 101 is fitted onto the columnar portion 302 of the terminal post 300 outside the housing 200, and then the first limiting portion 301 of the terminal post 300 is riveted with an outward flange. In another example, the columnar portion 302 is pre-fitted with the sealing ring 400 and the lower plastic 102, and after the columnar portion 302 passes through the first mounting hole 203, the first limiting portion 301 is riveted with an outward flange.

[0051] See also Figure 6 And see also Figure 10 In some embodiments, the sealing ring 400 has a portion sandwiched between the end wall 201 and the second limiting portion 303, the width of which in the radial direction is W1 mm. This width W1 can be referred to as the effective sealing width (i.e., the portion of the sealing ring 400 that is fully compressed, i.e., the radial width of the portion of the sealing ring 400 that is simultaneously sandwiched between the end wall 201 and the second limiting portion). Figure 10As shown, in the free state of the sealing ring 400, the radial width of the sealing ring 400 is W6 mm, where 0.15×W6≤W1≤0.45×W6. If W6 is small, for example, 0.45×W6≤W1, the sealing reliability of the sealing ring 400 cannot be guaranteed, and a certain effective sealing width is required; if W6 is too large, for example, 0.15×W6≤W1, the rebound force of the sealing ring 400 is too large, which will affect the riveting strength of the riveting flange.

[0052] See also Figure 9 and Figure 10 In some embodiments, the sealing ring 400 has a first top surface 404 facing away from the second surface 401. In the free state, the distance between the first top surface 404 and the second surface 401 along the axial direction I of the sealing ring 400 is equal to the maximum thickness W5 mm of the sealing ring 400. Furthermore, the distance between the third edge 4022 of the sealing ring and the first top surface 404 along the axial direction I of the sealing ring 400 is W4 mm. Preferably, 0.2 × W5 ≤ W4 ≤ 0.8 × W5. If W4 is relatively small, for example, 0.2 × W5 > W4, the ease of processing and stability of the sealing ring 400 are difficult to guarantee. If W4 is relatively large, for example, W4 > 0.8 × W5, the compressive stability of the sealing ring 400 is difficult to guarantee.

[0053] See above Figures 3 to 6 The first limiting part 301 of the pole post is described as having an externally riveted flange. Figures 11 to 13 In the example shown, the first limiting part of the pole is shown as an inner riveted flange. Figure 11 A top view schematic diagram of a secondary battery 100 according to some embodiments of this application is shown. Figure 12 It shows Figure 11 A schematic axial cross-sectional view of the secondary battery 100 taken along the FF section is shown. For simplicity, only one side of the terminal post is shown. Figure 13 It shows Figure 12 A magnified view of a portion of region G. See also... Figure 13 The first limiting part 301 with internal riveting and flange is located inside the housing, the second limiting part 303 is located outside the housing, and the sealing ring 400 is disposed between the second limiting part 303 and the surface of the end wall 201 facing the outside of the housing. Figure 13 The first chamfered transition surface 402 of the sealing ring and the second chamfered transition surface 304 of the pole post are also shown, which abut against each other. Except for the first limiting part being an inner riveted flange and the mating position of the sealing ring and the second limiting part on the outer side of the housing, the foregoing description of the first limiting part, the second limiting part, the sealing ring, and the mating of the sealing ring and the second limiting part of the pole post are all applicable here, and will not be repeated.

[0054] Embodiments of this application also provide a battery pack 1002, including a secondary battery 100 of any of the above-described embodiments, and the battery pack 1002 may have the beneficial effects described above with respect to the secondary battery 100.

[0055] Embodiments of this application also provide an electronic device 1000, which includes a battery pack 1002 of any of the above-mentioned components, and the electronic device 1000 may have the beneficial effects described above with respect to the secondary battery 100.

[0056] The technical solution provided in this application at least avoids the sealing ring from lifting after riveting, which would affect the effective sealing area of ​​the sealing ring between the terminal and the shell, thereby affecting the airtightness of the secondary battery and causing abnormal performance.

[0057] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A secondary battery, characterized in that, include: The housing includes an end wall and a side wall surrounding the end wall, wherein a first mounting hole is provided on the end wall; The pole has a columnar portion, a first limiting portion and a second limiting portion passing through the first assembly hole. The first limiting portion and the second limiting portion are respectively connected to the two ends of the columnar portion and extend to the outer periphery of the end wall. The first limiting portion is a riveted flange. A sealing ring is disposed between the second limiting portion and the end wall and is sleeved on the columnar portion; The second limiting portion has a first surface facing the end wall, and the first surface is connected to the first peripheral side surface of the columnar portion through a first chamfered transition surface. Furthermore, the sealing ring has a second surface and a second circumferential side surface, the first surface abuts against the second surface, the first circumferential side surface is opposite to the second circumferential side surface, the second circumferential side surface is connected to the second surface through a second chamfer transition surface, and the first chamfer transition surface abuts against the second chamfer transition surface.

2. The secondary battery according to claim 1, characterized in that, The first chamfered transition surface has a first edge that contacts the first peripheral side surface and a second edge that contacts the first surface. In the radial direction of the pole post, the first edge and the second edge are spaced apart by a length of C2 mm, and in the axial direction of the pole post, the first edge and the second edge are spaced apart by a length of C4 mm. The second chamfered transition surface has a third edge that contacts the second peripheral side surface and a fourth edge that contacts the second surface, wherein: in the free state of the sealing ring, the distance between the third edge and the fourth edge in the radial direction of the sealing ring is C1 mm, and the distance between the third edge and the fourth edge in the axial direction of the sealing ring is C3 mm; Where C1≥C2; and / or, C3≥C4.

3. The secondary battery according to claim 2, characterized in that, 0.2≤C1≤1.0, 0.2≤C3≤1.

0.

4. The secondary battery according to claim 1, characterized in that, The second chamfered transition surface has a fourth edge that is in contact with the second surface, and in the radially outward direction of the pole post, the fourth edge does not extend beyond the wall of the first mounting hole.

5. The secondary battery according to claim 4, characterized in that, In the radial direction of the pole post, the distance between the fourth edge and the wall of the first mounting hole is W2 mm, and the distance between the first circumferential side of the columnar portion and the wall of the first mounting hole is W3 mm, 0.1≤W2 / W3≤0.

6.

6. The secondary battery according to claim 2, characterized in that, The sealing ring has a first top surface facing away from the second surface. In the free state of the sealing ring, the distance between the first top surface and the second surface in the axial direction of the sealing ring is the maximum thickness W5 mm of the sealing ring. In the free state of the sealing ring, the distance between the third edge and the first top surface in the axial direction of the sealing ring is W4 mm. Wherein, 0.2×W5≤W4≤0.8×W5.

7. The secondary battery according to claim 1, characterized in that, The portion of the sealing ring that is held between the end wall and the second limiting portion has a radial width of W1 mm. In its free state, the sealing ring has a radial width of W6 mm, where 0.15×W6≤W1≤0.45×W6.

8. The secondary battery according to claim 1, characterized in that, The first chamfer transition surface is set as a rounded corner surface with a radius of R2 mm. In the free state of the sealing ring, the second chamfer transition surface is set as a rounded corner surface with a radius of R1 mm, wherein R1 ≥ R2.

9. A battery pack, characterized in that, The secondary battery includes any one of claims 1 to 8.

10. An electronic device, characterized in that, Includes the battery pack as described in claim 9.

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