Secondary battery and electronic device

Abstract

The utility model provides a secondary battery which comprises a shell which comprises an end wall which is provided with a first assembly hole; the lower plastic is in contact with the surface, facing the interior of the shell, of the end wall, and the lower plastic is provided with a second assembly hole corresponding to the first assembly hole; the pole comprises a columnar part and an inner flange, the columnar part penetrates through the first assembly hole and the second assembly hole, and the inner flange is connected with one end, located in the shell, of the columnar part and clamps the lower plastic together with the end wall; the electrode assembly is accommodated in the shell, and the electrode assembly comprises a tab facing the end wall; the switching piece is located between the lower plastic and the electrode assembly, the switching piece comprises a pole connecting part connected with the columnar part and a tab connecting part connected with the tab, and the inner flange is located between the pole connecting part and the lower plastic; and the supporting structure is arranged between the lower plastic and the tab connecting part so as to support the lower plastic and the tab connecting part. The utility model aims to provide a secondary battery and an electronic device so as to at least reduce the possibility of tab tearing.

Description

Technical Field

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

[0002] In the field of new energy power 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. Utility Model Content

[0003] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a secondary battery and electronic device to at least reduce the possibility of electrode tab tearing.

[0004] To achieve the above objectives, this utility model provides a secondary battery, comprising: a housing, including an end wall having a first mounting hole; a lower plastic contacting the surface of the end wall facing the interior of the housing, the lower plastic having a second mounting hole corresponding to the first mounting hole; an electrode post including a columnar portion and an inner flange, the columnar portion passing through the first and second mounting holes, the inner flange being connected to one end of the columnar portion located inside the housing and clamping the lower plastic together with the end wall; an electrode assembly housed within the housing, the electrode assembly including tabs facing the end wall; an adapter piece located between the lower plastic and the electrode assembly, the adapter piece including an electrode post connecting portion connecting the columnar portion and an electrode tab connecting portion connecting the tabs, the inner flange being located between the electrode post connecting portion and the lower plastic; and a support structure disposed between the lower plastic and the electrode tab connecting portion to support the lower plastic and the electrode tab connecting portion.

[0005] In some embodiments, the support structure is integral with the lower plastic or the adapter piece, or the support structure includes a first part and a second part, wherein the first part is integral with the lower plastic, the second part is integral with the adapter piece, and the first part abuts against the second part.

[0006] In some embodiments, the support structure supports the tab connection portion away from the outer edge of the pole post connection portion.

[0007] In some embodiments, the electrode connection includes a welding area welded to the electrode and a plurality of spaced-apart weight-reducing holes penetrating the adapter piece, a support structure supports the welding area, and the projection of the weight-reducing holes along the radial direction of the electrode post is offset from the support structure.

[0008] In some embodiments, the welding zone has a plurality of welds formed by welding with the electrode tabs, a plurality of support structures corresponding one-to-one with the welds, and the radial projection of the welds along the electrode post at least partially coincides with the support structures.

[0009] In some embodiments, the surface of the lower plastic facing the adapter piece has reinforcing ribs disposed around the second mounting hole and protruding toward the adapter piece, and a support structure is disposed between the reinforcing ribs and the electrode tab connection portion to support the reinforcing ribs and the electrode tab connection portion.

[0010] In some embodiments, the surface of the lower plastic away from the end wall has a first reinforcing rib surrounding the second mounting hole, a third reinforcing rib surrounding the first reinforcing rib, and a second reinforcing rib connecting the first reinforcing rib and the third reinforcing rib, and the support structure is disposed on the third reinforcing rib and located at the position where the third reinforcing rib and the second reinforcing rib are connected.

[0011] In some embodiments, the surface of the lower plastic away from the end wall has a first reinforcing rib surrounding the second mounting hole, a second reinforcing rib surrounding the first reinforcing rib, and a third reinforcing rib connecting the first and second reinforcing ribs.

[0012] The support structure is set on the third reinforcing rib and is disconnected at the position where the third reinforcing rib connects to the second reinforcing rib.

[0013] In some embodiments, along the axial direction of the pole post, the sum of the thickness of the reinforcing rib and the thickness of the support structure is the same as the thickness of the inner flange of the pole post.

[0014] Embodiments of this application also provide an electronic device including any of the above-described secondary batteries.

[0015] The beneficial technical effects of this utility model are as follows:

[0016] The embodiments of this application provide a support structure between the tab connection and the lower plastic to add a physical limiting structure to the hollow space between the adapter piece and the lower plastic, thereby improving the impact resistance of the secondary battery in the axial direction of the electrode post, reducing the axial deformation of the tab connection, and thus preventing the tab connected to the tab connection from tearing. Attached Figure Description

[0017] 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.

[0018] Figure 1 A partial cross-sectional view of a prior art secondary battery is shown, along with an enlarged view of region A of the cross-sectional view.

[0019] Figure 2 A schematic diagram is shown when the electronic device according to an embodiment of this application is a vehicle.

[0020] Figure 3 A perspective view of a secondary battery according to an embodiment of this application is shown.

[0021] Figure 4 A portion of a cross-sectional view of a secondary battery according to an embodiment of this application is shown, as well as an enlarged view of region B of the cross-sectional view.

[0022] Figure 5 It shows the relationship with Figure 4 Partial cross-sectional views of secondary batteries from different embodiments.

[0023] Figures 6 to 8 Perspective views of the adapter piece according to the first embodiment of this application are shown at different angles, wherein Figure 6 and Figure 7 The side of the adapter plate facing downwards is shown. Figure 8 The side of the adapter plate facing the electrode assembly is shown.

[0024] Figure 9 A perspective view of the lower plastic according to a first embodiment of the present application is shown, showing the side of the lower plastic facing the adapter piece 20.

[0025] Figure 10 A perspective view shows the adapter piece and the lower plastic assembly according to the first embodiment of this application.

[0026] Figures 11 to 13 Perspective views of the lower plastic at different angles according to a second embodiment of the present application are shown, showing the side of the lower plastic facing the adapter piece.

[0027] Figure 14 A perspective view of an adapter piece according to a second embodiment of this application is shown, showing the side of the adapter piece with the plastic facing downwards.

[0028] Figure 15 A perspective view shows the adapter piece and the lower plastic assembly according to the second embodiment of this application.

[0029] Figure 16 A front view showing the adapter piece and the lower plastic assembly according to a second embodiment of this application is shown.

[0030] Figure 17 and Figure 18 Perspective views of the lower plastic at different angles according to a third embodiment of this application are shown, showing the side of the lower plastic facing the adapter piece.

[0031] Figure 19 A front view showing the adapter piece and the lower plastic assembly according to a third embodiment of this application is shown.

[0032] Figure 20A perspective view shows the adapter piece and the lower plastic assembly according to the fourth embodiment of this application.

[0033] Figure 21 A front view of the adapter piece and the lower plastic assembly according to the fourth embodiment of this application is shown.

[0034] Figure 22 The simulation results show the existing technology's adapter plate, lower plastic, electrode post, and electrode assembly, as well as the coordinate values ​​of various points on the surface of the adapter plate.

[0035] Figure 23 The simulation results of the support structure, adapter plate, lower plastic, pole, and electrode assembly of this application are shown, along with the coordinate values ​​of various points on the surface of the adapter plate. Detailed Implementation

[0036] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Figure 1 The diagram shows a partial cross-sectional view of a prior art secondary battery, as well as an enlarged view of region A of the cross-section. The secondary battery includes an adapter plate 1 and a lower plastic insert 2. The adapter plate 1 connects the terminal post 3 (e.g., a positive terminal post) and the positive electrode tab of the electrode assembly 4, and handles overcurrent. The lower plastic insert 2 provides insulation, separating the positive electrode (terminal post 3, adapter plate 1, positive electrode tab) from the negative electrode (casing 5) to prevent short circuits. In prior art secondary batteries, the space between the adapter plate 1 and the lower plastic insert 2 is occupied by the flange 6 of the terminal post 3, resulting in a large axial (Z-direction, height direction) gap between the adapter plate 1 and the lower plastic insert 2. When the secondary battery is subjected to axial impact, due to the lack of physical restraint between the adapter plate 1 and the lower plastic insert 2, the adapter plate 1 is prone to deformation, ultimately leading to tearing of the electrode tab welded to the adapter plate 1.

[0042] This utility model provides an electronic device 1000. In some embodiments, the electronic device 1000 may include a battery pack, a battery group 1002, an electric vehicle, an energy storage cabinet, etc. For ease of explanation, the following embodiments will use a vehicle as an example to illustrate the electronic device 1000. Figure 2 A schematic diagram of an electronic device according to an embodiment of this application is shown when it is a vehicle. See also Figure 2 The vehicle has a battery pack 1002 installed inside, 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. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. The vehicle 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 movement or the operation of its internal electrical components. However, in some other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical energy from the battery pack 1002 and perform corresponding functions, such as a fan blade rotation unit or a vacuum cleaner's 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.

[0043] Figure 3 A perspective view of a secondary battery 100 according to an embodiment of this application is shown. Figure 4 A portion of a cross-sectional view of a secondary battery 100 according to an embodiment of this application is shown, as well as an enlarged view of region B of the cross-sectional view. Figure 5 It shows the relationship with Figure 4 Partial cross-sectional views of the secondary battery 100 in different embodiments, and Figure 4 The difference is that, Figure 5 In one embodiment, the adapter piece 20 also includes a protrusion 26 protruding toward the columnar portion 52 of the pole post 50, the protrusion 26 being electrically connected to the pole post 50.

[0044] This application provides a secondary battery 100, which includes a housing 200, an electrode assembly 10 located within the housing 200, an adapter plate 20, and terminal posts 50 mounted on the housing 200. The housing 200 includes an end wall 111 and a side wall 112 surrounding the end wall 111. The housing 200 can be formed in various ways, such as integral stamping, integral casting, or separate welding, as long as a stable seal and electrical connection can be established. A receiving cavity is formed within the housing 200 to accommodate the electrode assembly 10, electrolyte, adapter plate 20, and other necessary battery components. Specifically, the diameter of the housing 200 can be determined according to the specific size of the electrode assembly 10. The housing 200 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent rusting during long-term use, a rust-preventive material such as metallic nickel can be plated onto the surface of the housing 200. The secondary battery 100 can be a cylindrical battery, such as a 4680 cylindrical battery with a height of 80mm and a diameter of 46mm; or a cylindrical battery with a height of 15mm and a diameter of 46mm.

[0045] Electrode assembly 10 is a component in the secondary battery 100 where electrochemical reactions occur. The housing 200 may contain one or more electrode assemblies 10. Electrode assembly 10 is a wound or stacked electrode assembly, including a stacked and / or wound positive electrode, a first separator, a negative electrode, and a second separator. The positive electrode includes a positive current collector and a positive active material layer coated on the positive current collector. A first coated area coated with the positive active material layer and a first uncoated area without the positive active material layer are formed on the positive current collector. The first coated area and the first uncoated area are arranged along the height direction of the electrode assembly. The first uncoated area extends outward from the separator at one end in the height direction of the secondary battery 100 and forms a bent positive electrode tab. The negative electrode includes a negative current collector and a negative active material layer coated on the negative current collector. A second coated area with the negative active material layer and a second uncoated area without the negative active material layer are formed on the negative current collector. The second coated area and the second uncoated area are arranged along the height direction of the electrode assembly. The second uncoated area also extends towards one end of the secondary battery 100 in the height direction to the outside of the separator, forming a bent negative electrode tab. The first separator and the second separator are disposed between the positive electrode and the negative electrode to isolate the positive and negative active material layers. Taking the lithium-ion secondary battery 100 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 material of the negative current collector can be copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The substrate material of the first separator and the second separator can be PP (polypropylene) or PE (polyethylene), etc. To protect and insulate the electrode assembly 10, an insulating film can be wrapped around the outside of the electrode assembly 10. The insulating film can be synthesized from PP, PE, PET, PVC or other polymer materials.

[0046] In some embodiments, the end wall 111 has a first mounting hole 1110, and the lower plastic 60 contacts the surface of the end wall 111 facing the interior of the housing 200. The lower plastic 60 has a second mounting hole 600 corresponding to the first mounting hole 1110. In some embodiments, the electrode post 50 includes an outer flange, a columnar portion 52, and an inner flange 61. The columnar portion 52 passes through the first mounting hole 1110 and the second mounting hole 600. The inner flange 51 is connected to one end of the columnar portion 52 of the electrode post 50 located inside the housing 200, and the inner flange 51 and the end wall 111 together clamp the lower plastic 60. The inner flange 51 of the electrode post 50 contacts the surface of the lower plastic 60 facing the electrode assembly 10 / the surface away from the end wall 111, and fixes the lower plastic 60 to the surface of the end wall 111 facing the interior of the housing 200. The adapter 20 includes a pole post connection portion 22 that connects to the columnar portion 52 and a tab connection portion 24 that connects to the tab (e.g., a positive tab) facing the end wall 111 of the electrode assembly 10.

[0047] Figures 6 to 8 Perspective views of the adapter piece 20 according to the first embodiment of this application are shown at different angles, wherein Figure 6 and Figure 7 The side of the adapter piece 20 facing downwards on the plastic 60 is shown. Figure 8 The side of the adapter 20 facing the electrode assembly 10 is shown. Figure 9 A perspective view of the lower plastic 60 according to a first embodiment of the present application is shown, showing the side of the lower plastic 60 facing the adapter piece 20. Figure 10 A perspective view shows the adapter piece 20 and the lower plastic piece 60 assembled together according to the first embodiment of this application.

[0048] Figures 11 to 13 Perspective views of the lower plastic 60 from different angles according to the second embodiment of this application are shown, showing the side of the lower plastic 60 facing the adapter piece 20. Figure 14 A perspective view of the adapter piece 20 according to a second embodiment of this application is shown, showing the side of the adapter piece 20 facing downwards onto the plastic 60. Figure 15 A perspective view shows the adapter piece 20 and the lower plastic piece 60 assembled together according to the second embodiment of this application. Figure 16 A front view showing the adapter piece 20 and the lower plastic piece 60 assembled together according to a second embodiment of this application is shown.

[0049] Figure 17 and Figure 18 Perspective views of the lower plastic 60 from different angles according to a third embodiment of the present application are shown, showing the side of the lower plastic 60 facing the adapter piece 20. Figure 19 A front view showing the adapter piece 20 and the lower plastic piece 60 assembled together according to a third embodiment of this application is shown.

[0050] Figure 20 A perspective view shows the adapter piece 20 and the lower plastic piece 60 assembled together according to the fourth embodiment of this application. Figure 21 A front view showing the adapter piece 20 and the lower plastic piece 60 assembled together according to the fourth embodiment of this application is shown.

[0051] In the first to fourth embodiments, the inner flange 51 of the electrode post 50 is located between the electrode post connecting portion 22 and the lower plastic 60, and the support structure 30 is disposed between the lower plastic 60 and the tab connecting portion 24 to support the lower plastic 60 and the tab connecting portion 24. The embodiments of this application, by providing the support structure 30 located between the tab connecting portion 24 and the lower plastic 60, add a physical limiting structure to the hollow space between the adapter piece 20 and the lower plastic 60, thereby improving the impact resistance of the secondary battery 100 in the axial direction of the electrode post 50, reducing the axial deformation of the tab connecting portion 24, and thus preventing the tab connected to the tab connecting portion 24 from tearing.

[0052] In the first embodiment, the adapter piece 20 is improved, and the support structure 30 is integral with the adapter piece 20. In the second and third embodiments, the lower plastic 60 is improved, and the support structure 30 is integral with the lower plastic 60. In the fourth embodiment, both the adapter piece 20 and the lower plastic 60 are improved. The support structure 30 includes a first part 31 and a second part 32. The first part 31 is integral with the lower plastic 60, and the second part 32 is integral with the adapter piece 20. The first part 31 abuts against the second part 32, and the first part 31 and the second part 32 cooperate to limit each other. In the first to fourth embodiments, the support structure 30 is integral with the adapter piece 20 and / or the lower plastic 60, thus fixing the relative position of the support structure 30 with the adapter piece 20 and the lower plastic 60. This is more convenient to assemble than a solution where the support structure 30 is independent of the adapter piece 20 and the lower plastic 60. Furthermore, the support structure 30 can be integrally molded with the adapter piece 20 and / or the lower plastic 60, simplifying the forming process.

[0053] In existing technologies, the axial displacement of the adapter piece is typically greatest at its outer edge. In the first to fourth embodiments of this application, the support structure 30 supports the outer edge of the tab connection portion 24 away from the pole post connection portion 22 to support the suspended end of the tab connection portion 24, thereby reducing the overall axial deformation of the adapter piece 20. In the first and fourth embodiments, the support structure 30 / second part 32 is formed at the outer edge of the tab connection portion 24. In the second and third embodiments, the support structure 30 abuts against the outer edge of the tab connection portion 24.

[0054] In the first to fourth embodiments, the tab connection portion 24 includes a welding area 240 for welding to the tab and a plurality of spaced-apart weight-reducing holes 242 penetrating the adapter piece 20. The structural strength of the tab connection portion 24 at the welding area 240 is greater than that at the weight-reducing holes 242. The support structure 30 supports the welding area 240 to reduce the overall axial deformation of the adapter piece 20. The projection of the weight-reducing holes 242 along the radial direction of the pole post 50 is offset from the support structure 30. Furthermore, the support structure 30 supports the welding area 240 to support the key portion of the adapter piece 20 used for welding to the tab, reducing the axial displacement of this key portion and preventing tearing of the tab. In the first and fourth embodiments, the support structure 30 / second portion 32 is formed in the welding area 240. In the second and third embodiments, the support structure 30 abuts against the welding area 240.

[0055] Furthermore, the welding area 240 has a plurality of welds 244 formed by welding with the electrode tab, and a plurality of support structures 30 correspond one-to-one with the welds 244, and the radial projection of the welds 244 along the pole post 50 at least partially overlaps with the support structures 30. That is, on the outside of each weld 244, there is a corresponding support structure 30 to support the transition piece welding area 240, so as to reduce the axial displacement of the electrode tab connection 24 at the weld 244 and avoid tearing of the electrode tab. In the first to fourth embodiments, see, for example, Figure 6 The illustration shows four welds 244 (the number of welds is not limited in the embodiments of this application), with the support structures on the outer sides of two opposing welds 244 being symmetrical about the line connecting the other two welds 244. That is, the four support structures 30 evenly divide the outer edge of the transition piece 20, and the circumferential distance between the support structures 30 is consistent. In the first and fourth embodiments, the support structure 30 / second portion 32 is formed on the outer side of the weld 244; in the second and third embodiments, the support structure 30 abuts against the outer side of the weld 244.

[0056] In the first to fourth embodiments, the surface of the lower plastic 60 facing the adapter piece 20 has reinforcing ribs 61 / 62 / 63 (a first reinforcing rib 61 surrounds the second mounting hole 600, a third reinforcing rib 63 surrounds the first reinforcing rib 61, and a second reinforcing rib 62 connects the first reinforcing rib 61 and the third reinforcing rib 63) disposed around the second mounting hole 600 and protruding towards the adapter piece 20. A support structure 30 is disposed between the reinforcing ribs and the tab connection portion 24 to support the reinforcing ribs and the tab connection portion 24. The support structure 30 is located on the reinforcing ribs that already protrude towards the adapter piece 20 on the lower plastic 60, thus reducing the required thickness of the support structure 30 (along the axial direction of the electrode post 50), thereby reducing the weight of the support structure 30 and also reducing the total weight of the secondary battery 100. In the first embodiment, the support structure 30 abuts against the reinforcing rib; in the second and third embodiments, the support structure 30 is formed on the reinforcing rib; and in the fourth embodiment, a first portion 31 of the support structure 30 is formed on the reinforcing rib. Along the axial direction of the electrode post 50, the sum of the thickness of the reinforcing rib and the thickness of the support structure 30 is the same as the thickness of the inner flange 51 of the electrode post 50, so as to keep the adapter piece 20 as a flat plate when the secondary battery 100 is subjected to axial impact or when the electrode assembly 10 expands.

[0057] In the first, second, and fourth embodiments, the support structure 30 is disposed on the third reinforcing rib 63 and located at the position where the third reinforcing rib 63 connects to the second reinforcing rib 62. The third reinforcing rib 63 corresponds to the outer edge of the transition piece 20, and the structural strength is higher at the position where the third reinforcing rib 63 connects to the second reinforcing rib 62, resulting in more stable support from the support structure 30. In the third embodiment, see, for example, [reference needed]. Figure 18 The intermittent support structure 30 is set on the third reinforcing rib 63, and is broken at the position where the third reinforcing rib 63 is connected to the second reinforcing rib 62 to form a break 34, which is conducive to the flow of electrolyte.

[0058] Figure 22 The simulation results of the adapter piece 1, lower plastic 2, electrode post 3, and electrode assembly 4 in the prior art are shown; and the coordinate values ​​of each point on the surface of the adapter piece 1 (the surface facing the lower plastic 2 or the surface facing the electrode assembly 4) are obtained, where the maximum value is 16.521 mm, the minimum value is 16.018 mm, and the maximum axial displacement (i.e., the maximum deformation) of the adapter piece 1 is about 0.5 mm.

[0059] Figure 23The simulation results of the support structure 30, adapter piece 20, lower plastic 60, electrode post 50, and electrode assembly 10 of this application are shown; and the coordinate values ​​of each point on the surface of the adapter piece 20 (the surface facing the lower plastic 60 or the surface facing the electrode assembly 10) are obtained, where the maximum value is 16.780 mm, the minimum value is 16.700 mm, and the maximum axial displacement (i.e., the maximum deformation) of the adapter piece 20 is about 0.08 mm, which is 84% ​​lower than that of the prior art.

[0060] 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 by comprising: The secondary battery comprises: a case including an end wall having a first fitting hole; a lower plastic in contact with a surface of the end wall facing an inside of the case, the lower plastic having a second fitting hole corresponding to the first fitting hole; a pole post including a post portion passing through the first fitting hole and the second fitting hole, and an inner flange connected to an end of the post portion inside the case and clamping the lower plastic together with the end wall; an electrode assembly accommodated in the case, the electrode assembly including a tab facing the end wall; a transition piece between the lower plastic and the electrode assembly, the transition piece including a tab connecting portion connected to the post portion and a tab connecting portion connected to the tab, the inner flange being between the tab connecting portion and the lower plastic; a support structure provided between the lower plastic and the tab connecting portion to support the lower plastic and the tab connecting portion.

2. The secondary battery according to claim 1, wherein: the support structure is a unitary piece with the lower plastic or the transition piece, or the support structure includes a first portion that is a unitary piece with the lower plastic and a second portion that is a unitary piece with the transition piece, the first portion abutting against the second portion.

3. The secondary battery according to claim 1, wherein: the support structure supports an outer edge of the tab connecting portion that faces away from the tab connecting portion.

4. The secondary battery according to claim 3, wherein: the tab connecting portion includes a welding area welded to the tab, and a plurality of mutually spaced weight-reducing holes passing through the transition piece, the support structure supports the welding area, and projections of the weight-reducing holes along a radial direction of the post portion are offset from the support structure.

5. The secondary battery according to claim 4, wherein: the welding area has a plurality of welds formed by welding to the tab, a plurality of support structures correspond one-to-one to the welds, and projections of the welds along the radial direction of the post portion at least partially coincide with the support structures.

6. The secondary battery according to claim 1, wherein: a surface of the lower plastic facing the transition piece has a reinforcing rib provided around the second fitting hole and protruding toward the transition piece, and the support structure is provided between the reinforcing rib and the tab connecting portion to support the reinforcing rib and the tab connecting portion.

7. The secondary battery according to claim 6, wherein: a surface of the lower plastic facing away from the end wall has a first reinforcing rib surrounding the second fitting hole, a third reinforcing rib surrounding the first reinforcing rib, and a second reinforcing rib connecting the first reinforcing rib and the third reinforcing rib, the support structure is provided on the third reinforcing rib and at a position where the third reinforcing rib is connected to the second reinforcing rib.

8. The secondary battery according to claim 6, wherein: a first reinforcing rib surrounding the second assembly hole, a second reinforcing rib surrounding the first reinforcing rib, and a third reinforcing rib connecting the first reinforcing rib and the second reinforcing rib on a surface of the lower plastic facing away from the end wall, the support structure is provided on the third reinforcing rib and is broken at a position where the third reinforcing rib connects with the second reinforcing rib.

9. The secondary battery according to claim 6, wherein the sum of the thickness of the reinforcing rib and the thickness of the support structure is the same as the thickness of the inner flange of the pole in the axial direction of the pole.

10. An electronic device, comprising: A secondary battery according to any one of claims 1 to 9.

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