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, with pole hole;Pole, with the columnar portion of through pole hole, with the outer flange of the end of columnar portion and is located the inside of shell, and with the inner flange of the end of columnar portion and is located the inside of shell, outer flange is riveting flanging;Upper plastic, between riveting flanging and the outer plane of end wall and is located the outside of shell;Sealing ring, between inner flange and the inner plane of end wall and is located the inside of shell;Upper plastic includes the first part and second part along first direction extension, first direction is perpendicular to the axial direction of the shell, and upper plastic is the part of second part by the outer plane, outer flange clamping, first part is arranged between second part and columnar portion, second part is connected with first part, and the compression rate of first part is greater than the compression rate of second part.The utility model forms double sealing effect together with sealing ring.

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] Secondary batteries typically consist of a casing and an electrode assembly. The electrode assembly includes a positive electrode, a first separator, a negative electrode, and a second separator, which are stacked sequentially to form a wound electrode assembly or a stacked electrode assembly. The casing has terminals electrically connected to the electrode assembly, and a sealing ring is used to seal the casing between the terminals and the casing. Nowadays, as battery performance improves, the sealing requirements for the casing also increase, and a single sealing ring is no longer sufficient to meet these requirements. 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 that the first part of the upper plastic is compressed to the maximum extent, forming a double sealing effect together with the sealing ring.

[0005] To achieve the above objectives, this utility model provides a secondary battery, comprising: a casing having an end wall and a side wall surrounding the end wall, the end wall having an electrode post hole; an electrode post having a columnar portion penetrating the electrode post hole, an outer flange connected to the end of the columnar portion located on the outer side of the casing, and an inner flange connected to the end of the columnar portion located on the inner side of the casing, the outer flange being a riveted flange; an upper plastic layer located between the riveted flange and the outer plane of the end wall located on the outer side of the casing; and a sealing ring located between the inner flange and the inner plane of the end wall located on the inner side of the casing; wherein, the upper plastic layer includes a first portion and a second portion extending along a first direction, the first direction being perpendicular to the axial direction of the casing, the portion of the upper plastic layer held by the outer plane and the outer flange being the second portion, the first portion being disposed between the second portion and the columnar portion, the second portion being connected to the first portion, and the compression ratio of the first portion being greater than the compression ratio of the second portion.

[0006] In some embodiments, the surface where the inner wall of the pole hole is located is the first reference surface, the area of ​​the upper plastic between the first reference surface and the second reference surface is the third part, the second reference surface L1 is connected to the riveting end point of the upper plastic and the end of the inner wall away from the inside of the housing, the compression ratio of the third part is greater than the compression ratio of the second part, and the compression ratio of the third part is less than the compression ratio of the first part.

[0007] In some embodiments, the maximum wall thickness of the upper plastic in the first part is T1 mm, and the maximum wall thickness of the second part is T2 mm, where 0.4 x T2 ≤ T1 ≤ 0.85 x T2.

[0008] In some embodiments, the end of the first portion away from the second portion has a first rounded corner region with a radius of R1 mm, wherein 0.8 ≤ R1 ≤ 1.5; the outer flange has a second rounded corner region that abuts against the first rounded corner region.

[0009] In some embodiments, the upper plastic further includes an inner edge and an outer edge, one end of the inner edge being connected to the first rounded corner region and extending into the pole hole, and the outer edge being connected to the first portion and extending in a direction away from the interior of the housing, wherein: in the radial direction of the housing, the distance between the inner side of the inner edge facing the pole and the outer wall of the columnar portion is W1 mm, and the distance between the inner wall of the pole hole and the outer wall of the columnar portion is W2 mm, wherein 0.08xW2≤W1≤0.4xW2.

[0010] In some embodiments, the distance between the inner peripheral sidewall of the outer edge of the housing facing the axis of the housing and the outer peripheral sidewall of the riveted flange facing away from the axis in the radial direction of the housing is W3 mm, wherein 0.05 ≤ W3 ≤ 0.3.

[0011] In some embodiments, a transition portion is provided between the outer peripheral sidewall of the riveted flange facing away from the axis of the housing and the top surface of the riveted flange facing away from the inner flange. In the axial direction of the housing, the distance between the top surface of the riveted flange and the riveting termination point is T3 mm, wherein:

[0012] The transition section is an inclined plane. In the radial direction of the shell, the width of the inclined plane is C1 mm; in the axial direction of the shell, the height of the inclined plane is C2 mm, where C1 < 0.5 x T3 and C2 < 0.5 x T3; or...

[0013] The transition section is a circular arc surface with a radius of R2 mm, where R2 < 0.5 x T3; or,

[0014] The transition section is stepped, including a stepped surface and a transition surface. The transition surface is connected to the top surface and extends along the axial direction of the shell. The transition surface is connected to the outer peripheral sidewall through the stepped surface. In the axial direction of the shell, the distance between the stepped surface and the top surface of the riveted flange is W4 mm. In the radial direction of the shell, the distance between the transition surface and the outer peripheral sidewall is W5 mm, where W4 < 0.5 x T3 and W5 < 0.5 x T3.

[0015] In some embodiments, the compression rate of the first portion is in the range of 30% to 50%, and the compression rate of the second portion is in the range of 5% to 25%.

[0016] This application also provides a battery pack, including any of the secondary batteries described in this application.

[0017] This application also provides an electronic device including any of the battery packs described in this application.

[0018] The beneficial technical effects of this utility model are at least as follows:

[0019] The embodiments of this application at least ensure that the upper plastic is compressed to the maximum extent in the first part, forming a double sealing effect together with the sealing ring. Attached Figure Description

[0020] 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.

[0021] Figure 1 A schematic diagram of an electronic device, using a vehicle as an example, is shown.

[0022] Figure 2 A perspective view of a secondary battery according to an embodiment of this application is shown.

[0023] Figure 3 A top view schematic diagram of a secondary battery according to an embodiment of this application is shown.

[0024] Figure 4 It shows along Figure 3 A schematic diagram of a cross-section taken from section AA.

[0025] Figure 5 It shows Figure 4 A magnified view of a portion of region B in the middle.

[0026] Figure 6A and Figure 6B It shows Figure 5 A magnified view of a portion of region C, in which... Figure 6A Used to indicate the first part, the second part, and the third part. Figure 6B Used to indicate other features.

[0027] Figure 7 Some embodiments according to this application are shown. Figure 5 A magnified view of a portion of region D.

[0028] Figure 8 Other embodiments according to this application are shown. Figure 5 A magnified view of a portion of region D.

[0029] Figure 9 Some embodiments according to this application are shown. Figure 5 A magnified view of a portion of region D. 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] 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.

[0036] 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. Figure 2 A perspective view of a secondary battery 100 according to an embodiment of this application is shown.

[0037] 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 cross-sectional view taken from section AA. See also an example of the secondary battery of this utility model. Figure 2 , Figure 3 as well as Figure 4 The electrode assembly is sealed and installed within the housing 200. In some embodiments, the electrode assembly has a first tab and a second tab at both ends in the height direction of the secondary battery 100, and the first tab and the second tab have opposite polarities, wherein the first tab faces the opening side and is the negative tab. It should be noted that in other embodiments, the first tab may also be the positive tab and the second tab may be the negative tab.

[0038] 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.

[0039] 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.

[0040] Figure 5 It shows Figure 4 A magnified view of a portion of region B. For ease of understanding, the sealing pins of the groove opening of the sealing pole are omitted from the diagram. Figure 6A and Figure 6B It shows Figure 5 A magnified view of a portion of region C in the middle, where, for clarity, Figure 6A It is mainly used to show Part A, Part B, and Part C. Figure 6B Primarily used to illustrate other features, both are magnified views of the same location. See also Figure 5 , Figure 6A as well as Figure 6BThe secondary battery 100 includes: a housing 200 having an end wall 201 and a side wall 202 surrounding the end wall 201, wherein the end wall 201 is provided with a terminal hole 2011; a terminal 300 having a columnar portion 301 penetrating the terminal hole 2011, an outer flange connected to the end of the columnar portion 301 located outside the housing 200, and an inner flange 303 connected to the end of the columnar portion 301 located inside the housing 200, wherein the outer flange is a riveted flange 302; an upper plastic 401 located between the riveted flange 302 and the outer plane 2012 of the end wall 201 located outside the housing 200; and a sealing ring 500 sealing the gap between the housing 200 and the terminal 300, wherein the sealing ring 500 is located between the inner flange 303 and the inner plane 2013 of the end wall 201 located inside the housing 200. The upper plastic 401 includes a first portion A and a second portion B extending along a first direction perpendicular to the axial direction of the housing. The portion of the upper plastic 401 held between the outer plane 2012 and the outer flange is the second portion A. The first portion A is disposed between the second portion B and the columnar portion. The second portion B is connected to the first portion A, and the compressibility of the first portion A is greater than that of the second portion B. The compressibility is the ratio of the difference between the wall thickness of the upper plastic 401 before compression and the wall thickness after compression to the wall thickness of the upper plastic 401 before compression. In this document, the term "compression ratio" has the same meaning.

[0041] It should be understood that, unless otherwise specified, the sealing ring 500 illustrated in the figures of this application represents the state of the sealing ring 500 before it is compressed. Figure 6A and Figure 6B The image shows the state of the sealing ring 500 after compression. In this example, before assembling the pole post 300 with the housing 200, the sealing ring 500 is fitted onto the columnar portion 301 of the pole post 300. The columnar portion 301 of the pole post 300 is passed through the pole post hole 2011 to assemble with the housing 200, and then the upper plastic 401 is fitted onto the columnar portion 301 of the pole post 300. Before assembly, the inner flange 303 is already formed, and the sealing ring 400 is fitted onto the columnar portion 301 and mates with the inner flange 303. After assembly, the upper plastic 401 is fitted onto the other end of the columnar portion 301, that is, the end located outside the housing 200, and then bent and riveted to form a riveted flange 302.

[0042] This application uses an outer flange as a riveting flange to apply a larger riveting force to the upper plastic 401 during the riveting process, thereby compressing the upper plastic 401. Furthermore, it should be understood that during the riveting flange process, the riveting flange 302 compresses the upper plastic 401, and the compressed upper plastic 401 simultaneously compresses the sealing ring 500 to seal the gap between the housing 200 and the pole post 300. In some embodiments, the compression rate of the first portion A is in the range of 30% to 50%, and the compression rate of the second portion B is in the range of 5% to 25%. At this time, the compression of the sealing ring 500 forms a first seal between the housing 200 and the pole post 300, and the upper plastic 401, especially the first portion A of the upper plastic 401, is also compressed, forming a second seal between the housing 200 and the pole post 300. Thus, the upper plastic 401 and the sealing ring 500 together form a double sealing effect on the housing 200 and the terminal post 300, resulting in a better sealing effect for the secondary battery 100.

[0043] Specifically, compared to the second part B, which is less subjected to the compression of the riveting flange 302, the first part A, which is compressed more under the pressure of the bending of the pole post 300, is compressed to the maximum extent. It is understood that if the compression ratio of the second part B is greater, then along the radial direction of the pole post 300, the second part B is prone to cracking at the riveting termination point I. Therefore, this application increases the local maximum compression ratio of the upper plastic 401 by making the compression ratio of the first part A greater than that of the second part B, and avoids the upper plastic 401 cracking at the riveting termination point I of the riveting flange 302 due to the large difference in force.

[0044] See Figure 6A The surface containing the inner wall 2011a of the pole post hole 2011 is the first reference surface L2. The second reference surface L1 connects the riveting end point I of the riveting flange on the upper plastic and the end of the inner wall 2011a away from the interior of the housing 200. The area of ​​the upper plastic 401 between the first reference surface L2 and the second reference surface L1 is the third part C. Figure 6A As can be seen, the third part C is a part of the second part B. The compression ratio of the third part C is greater than that of the second part B, and the compression ratio of the third part C is less than that of the first part A. This is to further reduce the possibility that the upper plastic 401 will be cracked at the riveting termination point I of the riveting flange 302 due to the large difference in force.

[0045] See also Figure 5 , Figure 6A and Figure 6BIn some embodiments, along the axial direction of the housing, the upper plastic 401 has a maximum wall thickness of T1 mm in the first portion A and a maximum wall thickness of T2 mm in the second portion B, where 0.4 x T2 ≤ T1 ≤ 0.85 x T2. The wall thickness of the first portion A is the distance from the surface of the first portion A facing the pole post 300 to the other surface. For example, see [link to relevant documentation]. Figure 6A The first part A has a first rounded corner region at the end away from the second part B. The wall thickness of the first rounded corner region is the distance from the surface facing the pole post 300 to the inner wall 2011a of the pole post hole 2011, specifically the distance between the surface facing the pole post 300 and the end of the inner wall 2011a away from the electrode assembly.

[0046] It should be understood that if the ratio of T1 to T2 is too small, for example, T1 / T2 < 0.4, it means that the upper plastic 401 is over-compressed in the first part A, which may lead to problems with insulation and pressure resistance of the upper plastic 401. Conversely, if the ratio of T1 to T2 is too large, for example, if T1 / T2 > 0.85, it means that the upper plastic 401 is under-compressed in the first part A, resulting in a weaker sealing effect. Limiting T1 / T2 within the above range ensures that the insulation and pressure resistance of the upper plastic 401 are not compromised, and ensures that the upper plastic 401 effectively seals, achieving a double sealing effect together with the sealing ring 500.

[0047] In some embodiments, the end of the first part A away from the second part B has a first rounded corner region with a radius of R1 mm, wherein 0.8 ≤ R1 ≤ 1.5. The outer flange has a second rounded corner region that abuts against the first rounded corner region. If the radius R1 of the first rounded corner region is small, for example, when R1 < 0.8, the bending area generated by the flange riveting of the pole post 300 may be small, and the bending area is prone to cracking, and the pole post bending process is more difficult; if the radius R1 of the first rounded corner region is large, for example, when R1 > 1.5, the compressive force of the flange riveting 302 on the sealing ring 500 (especially the compressive force decomposed into the direction perpendicular to the end wall) may be reduced or limited after the flange riveting 302 is completed, that is, the compressive force of the flange riveting 302 and the end wall 201 on the sealing ring 500 is reduced, and the sealing ring 500 is not fully compressed, resulting in weakened sealing performance.

[0048] In some embodiments, the upper plastic 401 includes an outer edge 4013 and an inner edge 4011. One end of the inner edge 4011 is connected to the first rounded corner region and extends into the pole hole 2011, while the outer edge 4013 is connected to the first portion A and extends in a direction away from the interior of the housing. The upper plastic 401 is better assembled with the housing 200 by means of the inner edge 4011, which extends into the pole hole 2011 and engages with the inner wall 2011a of the pole hole 2011. Furthermore, during riveting, the inner edge 4011 prevents the upper plastic 401 from slipping relative to the housing 200 under stress, thus positioning the upper plastic 401 with the housing 200 during riveting. Figure 6A and Figure 6B It can be seen that the inner edge 4011 is located between the inner wall 2011a of the pole hole 2011 and the columnar part 301, and one end of the inner edge 4011 facing the inner flange 303 abuts against the sealing ring 500.

[0049] See also Figure 5 , Figure 6A and Figure 6B In some embodiments, in the radial X direction of the housing 200, the distance between the inner side surface 4111 of the inner edge 4011 facing the pole post 300 and the outer side wall of the columnar portion 301 is W1 mm, and the distance between the inner side wall 2011a of the pole post hole 2011 and the outer side wall of the columnar portion 301 is W2 mm, wherein 0.08 x W2 ≤ W1 ≤ 0.4 x W2. If the ratio of W1 to W2 is small, for example, if W1 / W2 < 0.08, the gap between the upper plastic 401 and the columnar portion 301 is too small, and the second rounded corner area formed during the riveting flange 302 folding process is prone to over-compressing the first part A, resulting in an excessively large compression ratio of the first part A. It can be understood that the setting of this gap is beneficial to the control of the compression ratio of the first part A. If the ratio of W1 to W2 is large, for example, if W1 / W2 > 0.4, the gap between the upper plastic 401 and the columnar part 301 will be too large. After riveting, the upper plastic 401 will wobble more than the columnar part 301, affecting the limiting effect of riveting on the upper plastic 401.

[0050] In some embodiments, in the radial direction X of the housing 200, the distance between the inner peripheral sidewall 4113 of the outer edge 4013 facing the axis H of the housing 200 and the outer peripheral sidewall 3021 of the riveting flange 302 facing away from the axis H of the housing 200 is W3 mm, where 0.05 ≤ W3 ≤ 0.3. If W3 is too small, for example, W3 < 0.05, the gap between the riveting flange 302 and the upper plastic 401 is too small. Since there are dimensional deviations in the riveting flange 302 and the upper plastic 401 during the production process, it is difficult to ensure assembly feasibility. If W3 is too large, for example, W3 > 0.3, the gap between the riveting flange 302 and the upper plastic 401 is too large, and the movable space of the pole post 300 is larger than that of the upper plastic 401. During the assembly process, it is easy to cause poor concentricity consistency between the pole post 300 and the upper plastic 401.

[0051] Figure 7 Some embodiments according to this application are shown. Figure 5 A magnified view of a portion of region D.

[0052] Figure 8 Other embodiments according to this application are shown. Figure 5 A magnified view of a portion of region D.

[0053] Figure 9 Some embodiments according to this application are shown. Figure 5 A magnified view of a portion of region D. See also Figure 7 , Figure 8 as well as Figure 9 In some embodiments, a transition portion 3023 is provided between the outer peripheral sidewall 3021 of the riveting flange 302 facing away from the axis H of the housing 200 and the top surface 3022 of the riveting flange 302 facing away from the inner flange 303. The transition portion 3023 is an arc surface, an inclined plane, or a stepped shape. By providing the transition portion 3023, the residual stress at the end of the riveting flange 302 facing away from the housing 200 after riveting and bending is released, enhancing the reliability of the riveting flange 302 during long-term use and continuously compressing the plastic 402.

[0054] In some embodiments, the distance between the top surface 3022 of the riveting flange 302 and the riveting termination point I along the axial Z direction of the housing 200 is T3 mm. In one example, as... Figure 7 As shown, when the transition portion 3023 is an inclined plane and surrounds the perimeter, the width of the inclined plane in the radial direction X of the housing 200 is C1 mm, and the height of the inclined plane in the axial direction Z of the housing 200 is C2 mm, where C1 < 0.5 x T3 and C2 < 0.5 x T3. If the dimensions of the transition portion 3023 are too large, for example, C1 ≥ 0.5 x T3 and C2 ≥ 0.5 x T3, it may lead to a decrease in the strength of the pole post 300. In another example, such as... Figure 8As shown, when the transition portion 3023 is an arc surface, the radius of the arc surface is R2 mm, where R2 < 0.5 x T3. Similar to the aforementioned, if the size of the transition portion 3023 is too large, for example, R2 ≥ 0.5 x T3, it may lead to a decrease in the strength of the pole post 300. In another example, such as... Figure 9 As shown, when the transition portion 3023 is stepped, it includes a stepped surface 3023b and a transition surface 3023a. The transition surface 3023a is connected to the top surface 3022 and extends along the axial direction of the housing. The transition surface 3023a is connected to the outer peripheral sidewall 3021 via the stepped surface 3023b. In the axial direction Z of the housing 200, the distance between the stepped surface 3023b and the top surface 3022 of the riveted flange 302 is W4 mm. In the radial direction X of the housing 200, the distance between the transition surface 3023a and the outer peripheral sidewall 3021 is W5 mm, where W4 < 0.5 x T3 and W5 < 0.5 x T3. Similar to the aforementioned, if the size of the transition portion 3023 is too large, for example, W4 ≥ 0.5 x T3 and W5 ≥ 0.5 x T3, it may lead to a decrease in the strength of the pole post 300.

[0055] 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.

[0056] 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.

[0057] The technical solution provided in this application at least enables the first part of the upper plastic to be compressed to the maximum extent, forming a double sealing effect together with the sealing ring.

[0058] 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 has an end wall and a side wall surrounding the end wall, and the end wall is provided with a pole post hole; The pole post has a columnar portion that passes through the pole post hole, an outer flange connected to the end of the columnar portion located on the outside of the housing, and an inner flange connected to the end of the columnar portion located on the inside of the housing, wherein the outer flange is a riveted flange. The plastic is applied between the riveted flange and the outer plane of the end wall located on the outside of the housing; A sealing ring is located between the inner flange and the inner plane of the end wall located inside the housing. The upper plastic includes a first part and a second part extending along a first direction, the first direction being perpendicular to the axial direction of the housing. The portion of the upper plastic held by the outer plane and the outer flange is the second part. The first part is disposed between the second part and the columnar portion. The second part is connected to the first part. The compression ratio of the first part is greater than that of the second part.

2. The secondary battery according to claim 1, characterized in that, The inner wall of the pole post hole is the first reference surface. The area of ​​the upper plastic between the first reference surface and the second reference surface is the third part. The second reference surface is connected to the riveting end point of the upper plastic and the end of the inner wall away from the inside of the housing. The compression ratio of the third part is greater than that of the second part and less than that of the first part.

3. The secondary battery according to claim 1, characterized in that, The maximum wall thickness of the upper plastic in the first part is T1 mm, and the maximum wall thickness of the second part is T2 mm, where 0.4 x T2 ≤ T1 ≤ 0.85 x T2.

4. The secondary battery according to claim 1, characterized in that, The first portion has a first rounded corner region at the end away from the second portion, the radius of the first rounded corner region being R1 mm, wherein 0.8 ≤ R1 ≤ 1.5; the outer flange has a second rounded corner region that abuts against the first rounded corner region.

5. The secondary battery according to claim 4, characterized in that, The upper plastic also includes: an inner edge and an outer edge, one end of the inner edge being connected to the first rounded corner region and extending into the pole hole, and the outer edge being connected to the first portion and extending in a direction away from the interior of the housing, wherein: In the radial direction of the housing, the distance between the inner side of the inner edge facing the pole post and the outer wall of the columnar part is W1 mm, and the distance between the inner wall of the pole post hole and the outer wall of the columnar part is W2 mm, wherein 0.08xW2≤W1≤0.4xW2.

6. The secondary battery according to claim 5, characterized in that, In the radial direction of the housing, the distance between the inner peripheral sidewall of the outer edge facing the axis of the housing and the outer peripheral sidewall of the riveted flange facing away from the axis is W3 mm, where 0.05 ≤ W3 ≤ 0.

3.

7. The secondary battery according to claim 1, characterized in that, A transition portion is provided between the outer peripheral sidewall of the riveted flange that is opposite to the axis of the housing and the top surface of the riveted flange that is opposite to the inner flange. In the axial direction of the housing, the distance between the top surface of the riveted flange and the riveting termination point is T3 mm, wherein: The transition section is an inclined plane. In the radial direction of the housing, the width of the inclined plane is C1 mm; in the axial direction of the housing, the height of the inclined plane is C2 mm, where C1 < 0.5 x T3 and C2 < 0.5 x T3; or... The transition section is an arc surface with a radius of R2 mm, where R2 < 0.5 x T3; or, The transition portion is stepped, including a stepped surface and a transition surface. The transition surface is connected to the top surface and extends along the axial direction of the housing. The transition surface is connected to the outer peripheral sidewall through the stepped surface. In the axial direction of the housing, the distance between the stepped surface and the top surface of the riveted flange is W4 mm. In the radial direction of the housing, the distance between the transition surface and the outer peripheral sidewall is W5 mm, where W4 < 0.5 x T3 and W5 < 0.5 x T3.

8. The secondary battery according to any one of claims 1 to 7, characterized in that, The compression rate of the first part is in the range of 30% to 50%, and the compression rate of the second part is in the range of 5% to 25%.

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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