Secondary battery, battery pack, and electronic device

Abstract

The utility model provides a secondary battery, a battery pack and an electronic device. The secondary battery comprises a shell, an electrode assembly, a pole, a sealing element and outer plastic, the shell comprises an end wall and a side wall surrounding the end wall, a pole hole is formed in the end wall, and the electrode assembly is arranged in the shell. The pole is riveted on the end wall and is electrically connected with the electrode assembly. The pole comprises an outer flange, the outer flange is located outside the shell, and the outer flange extends from the pole hole to the outer periphery of the end wall. The sealing piece is arranged between the outer flange and the end wall, the outer plastic comprises a first plastic part and a second plastic part, and the first plastic part surrounds the periphery of the outer flange; the second plastic part extends from the first plastic part to the pole hole; the second plastic part is arranged between the end wall and the outer flange. In the thickness direction of the end wall, the projections of the outer plastic and the sealing piece on the end wall at least partially coincide, the sealing piece isolates the outer plastic from the end wall, and the technical problem that the outer plastic is damaged, and the product yield is affected can be solved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a secondary battery, battery pack, and electronic device. Background Technology

[0002] Cylindrical batteries have garnered widespread attention in the industry due to their high production efficiency and energy density, leading to their large-scale adoption. The terminals of a cylindrical battery are formed by riveting, and plastic components and sealing rings are typically used around the terminals to create a sealed structure at the positive electrode. During the riveting process, the terminal flange undergoes a 90-degree bend, involving significant material flow and deformation. Simultaneously, the sealing ring is compressed, and the outer plastic also deforms accordingly. This can cause the outer plastic to detach or be crushed, resulting in contact between the terminal and the casing, posing a short-circuit risk and impacting product yield. Utility Model Content

[0003] This utility model provides a secondary battery, a battery pack, and an electronic device to improve the technical problem of damage to the outer plastic, which affects the product yield.

[0004] To achieve the above and other related objectives, this utility model provides a secondary battery, comprising a housing, an electrode assembly, terminals, a seal, and an outer plastic component. The housing includes an end wall and a side wall surrounding the end wall. A terminal hole is formed in the end wall, and the electrode assembly is disposed within the housing. The terminal is riveted to the end wall and electrically connected to the electrode assembly. The terminal includes an outer flange located outside the housing and extending from the terminal hole towards the outer periphery of the end wall. The seal is disposed between the outer flange and the end wall. The outer plastic component includes a first plastic portion and a second plastic portion. The first plastic portion surrounds the outer periphery of the outer flange. The second plastic portion extends from the first plastic portion towards the terminal hole and is disposed between the end wall and the outer flange. Along the thickness direction of the end wall, the projections of the outer plastic component and the seal on the end wall at least partially overlap, and the seal isolates the outer plastic component from the end wall.

[0005] In the above technical solution, the seal isolates the outer plastic from the end wall. The projections of the outer plastic and the seal on the end wall at least partially overlap, thus forming an overlapping area to increase the sealing surface of the seal and enhance the sealing effect between the end wall and the terminal. Simultaneously, the seal isolates the outer plastic from the end wall, allowing the seal to absorb most of the compressive energy from the end wall during the entire riveting process. The outer plastic does not need to directly bear the pressure from the end wall, reducing deformation and thus lowering the probability of it being crushed or detached, thereby avoiding the risk of short circuits caused by contact between the terminal and the casing. The first plastic part extends the surface insulation path between the casing and the outer surface of the terminal, increasing the surface creepage distance between them, further reducing the probability of electrical contact between the end wall and the terminal, and improving the battery's insulation performance and safety. Furthermore, due to the reduced deformation of the outer plastic, a material with lower elongation at break can be used to make the outer plastic, reducing production costs. This improves the technical problem of the outer plastic breaking or detaching, which affects product yield.

[0006] In one example of the secondary battery of this utility model, the sealing element and the outer plastic are separate structures.

[0007] In the above technical solution, the separate structure design of the seal and the outer plastic, compared with the integrated structure design, means that when the seal is deformed by external force, the direct impact of the seal on the outer plastic is smaller, further reducing the probability of the seal falling off or crushing the outer plastic. At the same time, the separate structure is more conducive to ensuring the reliability of the sealing and insulation between the electrode and the shell, effectively preventing the electrode from shifting or deforming during long-term use, while still maintaining good sealing and insulation performance.

[0008] In one example of the secondary battery of this utility model, the outer radial side of the outer flange includes a first notch facing the end wall, at least a portion of the second plastic part is accommodated in the first notch, and at least a portion of the seal overlaps the second plastic part located at the first notch.

[0009] In the above technical solution, the sealing element and the outer plastic form a laminated structure. The cooperation between the sealing element and the outer plastic not only achieves sealing and insulation between the end wall and the outer flange, but also eliminates the contact area between the outer plastic and the casing, thereby reducing the probability of the outer plastic being crushed or detached during the terminal post riveting process and reducing the risk of battery short circuit. The design of the first notch can reduce the proportion of the terminal post's space outside the casing in the overall battery space, even with limited terminal post height. At the same time, it enables the installation and fixation of the outer plastic, reducing assembly complexity.

[0010] In one example of the secondary battery of this utility model, the edge of the seal extends beyond the edge of the outer plastic along the direction from the axis of the electrode post to the outer periphery of the end wall.

[0011] In the above technical solution, the sealing surface of the seal is enlarged, increasing the overlap area between the outer plastic and the seal, improving the stability of the outer plastic assembly, and further reducing the probability of the outer plastic falling off. At the same time, the increased sealing surface enhances the sealing effect.

[0012] In one example of the secondary battery of this utility model, the edge of the outer plastic extends beyond the edge of the seal along the direction from the axis of the electrode post to the outer periphery of the end wall.

[0013] In the above technical solution, the outer plastic effectively conceals the seal, ensuring the uniformity of the battery's appearance and making the battery look cleaner and more aesthetically pleasing. The seal is hidden between the outer plastic and the end wall, slowing down the aging process of the seal and reducing the probability of seal damage, thus extending the battery's lifespan.

[0014] In one example of the secondary battery of this utility model, the terminal post further includes a groove and a sealing pin. The groove is formed on the outside of the terminal post, the sealing pin overlaps and is welded to the outer flange, and at least part of the sealing pin is accommodated in the groove. The thickness of the outer flange at the welding position with the sealing pin is T, where 1mm≤T≤3mm.

[0015] In the above technical solution, the outer flange at the welding position to the sealing pin is thickened. By limiting the thickness of the outer flange at the welding position to no less than 1mm, the overall rigidity and strength of the outer flange are increased, and its resistance to thermal stress changes during welding is improved. When the sealing pin is welded to the outer flange, it prevents the edge of the outer flange from warping due to thermal expansion and contraction during welding. By limiting the thickness of the outer flange at the welding position to no more than 3mm, the overall height of the electrode post is controlled, reducing the proportion of the space outside the casing in the overall battery space, ensuring the battery's capacity density and energy density, and improving the battery's space utilization rate.

[0016] In one example of the secondary battery of this utility model, the sealing element and the outer plastic are integrally formed. The integrally formed sealing element and the outer plastic isolate the end wall and the outer flange, and cover the side of the outer flange away from the axis of the electrode post.

[0017] In the above technical solution, the integrated design of the seal and the outer plastic layer more effectively isolates the end wall and the outer flange, providing better sealing and isolation effects. This further prevents electrical contact between the end wall and the outer flange, reducing the risk of battery leakage and short circuits. Simultaneously, the integrated design of the seal and the outer plastic layer reduces the number of components and assembly steps, improving production efficiency and reducing costs.

[0018] In one example of the secondary battery of this utility model, the seal and the outer plastic of the integral structure further include a third plastic part, which extends from the first plastic part toward the electrode hole; the outer side of the outer flange radially includes a second notch away from the end wall, and at least a portion of the third plastic part is accommodated in the second notch.

[0019] In the above technical solution, the third plastic part can cooperate with the first and second plastic parts to snap onto the outer periphery of the outer flange, enabling rapid assembly and fixation of the outer plastic on the outer flange, thus improving battery assembly speed and efficiency. Simultaneously, a portion of the third plastic part is accommodated within the second notch, reducing the proportion of the electrode's space outside the casing within the overall battery space, even with limited electrode height. The third plastic part increases the surface creepage distance between the end wall and the outer flange compared to the first plastic part, further reducing the probability of electrical contact between the end wall and the electrode, thereby improving the battery's insulation performance and safety.

[0020] This utility model also provides a battery pack, which includes any of the above-mentioned secondary batteries.

[0021] This invention also provides an electronic device that includes the aforementioned battery pack.

[0022] This utility model relates to a secondary battery where a sealing element isolates the outer plastic from the end wall. The projections of the outer plastic and the sealing element onto the end wall at least partially overlap, forming an overlapping area to increase the sealing surface of the sealing element and enhance the sealing effect between the end wall and the terminal. Simultaneously, the sealing element isolates the outer plastic from the end wall, allowing the sealing element to absorb most of the compressive energy from the end wall during the entire riveting process. The outer plastic does not directly bear the pressure from the end wall, reducing deformation and thus lowering the probability of it being crushed or detached, thereby avoiding the risk of short circuits caused by contact between the terminal and the casing. The first plastic portion extends the surface insulation path between the casing and the outer surface of the terminal, increasing the surface creepage distance between them and further reducing the probability of electrical contact between the end wall and the terminal, improving the battery's insulation performance and safety. Furthermore, the outer plastic can be made from a material with low elongation at break, reducing production costs. This improves the technical problem of outer plastic breakage or detachment affecting product yield. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0024] Figure 1This is a schematic diagram of the overall structure of an example of a secondary battery of this utility model;

[0025] Figure 2 This is a schematic diagram of the electrode assembly structure of an example of the secondary battery of this utility model;

[0026] Figure 3 This is a partial three-dimensional structural schematic diagram of an example of a secondary battery of this utility model;

[0027] Figure 4 for Figure 3 A magnified structural diagram of region A;

[0028] Figure 5 This is a partial structural schematic diagram of an example of a secondary battery of this utility model;

[0029] Figure 6 for Figure 5 A magnified structural diagram of region B;

[0030] Figure 7 This is a partial structural schematic diagram of another example of the secondary battery of this utility model;

[0031] Figure 8 This is a partial structural schematic diagram of another example of the secondary battery of this utility model;

[0032] Figure 9 for Figure 8 A magnified structural diagram of region C;

[0033] Figure 10 This is a schematic diagram of an example of the battery pack of this utility model;

[0034] Figure 11 This is a schematic diagram of an example of the electronic device of this utility model.

[0035] Component designation explanation:

[0036] 1. Electronic device; 10. Battery pack; 101. Housing; 102. Cover; 11. Working part; 100. Secondary battery; 110. Housing; 111. End wall; 1111. Terminal hole; 112. Side wall; 113. Opening; 120. Electrode assembly; 121. Positive electrode; 1211. Positive current collector; 1212. First coated area; 1213. First uncoated area; 122. Separator; 123. Negative electrode; 1231. Negative current collector; 1232. Second coated area; 1233. Second uncoated area ; 124. Negative electrode tab; 125. Positive electrode tab; 130. Terminal post; 131. Columnar part; 132. Outer flange; 1321. First notch; 1322. Second notch; 133. Inner flange; 134. Groove; 135. Sealing pin; 140. Sealing and insulating assembly; 141. Inner plastic; 1411. Fourth plastic part; 1412. Fifth plastic part; 142. Seal; 143. Outer plastic; 1431. First plastic part; 1432. Second plastic part; 1433. Third plastic part; 150. Cover plate. Detailed Implementation

[0037] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0038] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0039] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0040] To address the technical problem of outer plastic being crushed or detached during the existing terminal post riveting process, which affects product yield, this utility model provides a secondary battery, battery pack, and electronic device. During the riveting process, the outer plastic of the secondary battery's terminals does not directly bear the pressure from the end walls, reducing deformation of the outer plastic and thus lowering the probability of it being crushed or detached. This avoids the risk of short circuits caused by contact between the terminal post and the casing, thereby improving product yield.

[0041] Please see Figures 1 to 11 This utility model provides a secondary battery, a battery pack and an electronic device. The secondary battery 100 includes a housing 110, an electrode assembly 120, a terminal post 130, a sealing and insulating assembly 140 and a cover plate 150.

[0042] Please see Figure 1 The housing 110 includes an end wall 111 and a side wall 112 surrounding the end wall 111. As long as a stable sealing and electrical connection can be formed, the connection between the end wall 111 and the side wall 112 can be achieved in various ways, such as integral stamping, integral casting, or separate welding. The circumference of the side wall 112 is not limited; it can be cylindrical or prismatic, or it can follow any other closed-loop contour that matches the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 is cylindrical, surrounding the outer edge of the end wall 111, with a circular opening 113 formed at the end of the side wall 112 facing away from the end wall 111. A receiving cavity is formed within the housing 110 formed by the end wall 111 and the side wall 112 to accommodate the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the diameter of the housing 110 can be determined according to the specific size of the electrode assembly 120, such as 18mm, 21mm, or 46mm. The shell 110 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. In order to prevent the shell 110 from rusting during long-term use, a layer of anti-rust material such as metallic nickel can be plated on the surface of the shell 110.

[0043] Please see Figures 1 to 2The electrode assembly 120 is disposed inside the housing 110 and is a component in the secondary battery 100 where electrochemical reactions occur. The housing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 includes an electrode sheet and a separator 122, which are wound to form a wound structure. Specifically, in this embodiment, the electrode assembly 120 includes a positive electrode sheet 121, a separator 122, and a negative electrode sheet 123 wound axially around the housing 110.

[0044] Please see Figures 1 to 2 The positive electrode 121 includes a positive current collector 1211 and a positive active material layer coated on the positive current collector 1211. A first coated area 1212 coated with the positive active material layer and a first uncoated area 1213 uncoated with the positive active material layer are formed on the positive current collector 1211. The first coated area 1212 and the first uncoated area 1213 are arranged along the axial direction of the housing 110. The first uncoated area 1213 extends to one end of the secondary battery 100 in the height direction to the outside of the separator 122 and is bent towards the axis of the housing 110 to form a stacked positive electrode tab 125.

[0045] Please see Figures 1 to 2 The negative electrode 123 includes a negative current collector 1231 and a negative active material layer coated on the negative current collector 1231. A second coated area 1232 coated with the negative active material layer and a second uncoated area 1233 uncoated with the negative active material layer are formed on the negative current collector 1231. The second coated area 1232 and the second uncoated area 1233 are arranged along the axial direction of the housing 110. The second uncoated area 1233 extends to the other end of the secondary battery 100 in the height direction to the outside of the separator 122 and is bent towards the axis of the housing 110 to form a stacked negative electrode tab 124.

[0046] Please see Figures 1 to 2A separator 122 is disposed between the positive electrode 121 and the negative electrode 123 to isolate the positive and negative active material layers. Taking a lithium-ion secondary battery 100 as an example, the positive current collector 1211 can be made of 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 current collector 1231 can be made of copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The substrate material of the separator 122 can be polypropylene (PP) or polyethylene (PE), etc. To protect and insulate the battery cell, an insulating film can also be wrapped around the outside of the battery cell. The insulating film can be synthesized from PP, PE, polyethylene terephthalate (PET), polyvinyl chloride (PVC), or other polymer materials.

[0047] Please see Figure 1 and Figure 2 Furthermore, in this invention, the positive electrode tab 125 faces the end wall 111 or the opening 113, while the negative electrode tab 124 faces the other end of the housing 110. In this embodiment, the positive electrode tab 125 faces the end wall 111 and is electrically connected to the terminal post 130, making the terminal post 130 positively charged. The negative electrode tab 124 faces the opening 113, and the housing 110 is electrically connected to the negative electrode tab 124, thus becoming negatively charged. However, in another embodiment, the negative electrode tab 124 can be connected to the terminal post 130, and the positive electrode tab 125 can be connected to the housing 110.

[0048] Please see Figure 1 The cover plate 150 is sealed and installed on the opening 113. The outer edge shape of the cover plate 150 corresponds to the shape of the opening 113 and is connected to the side wall 112 to seal the opening 113. The installation method of the cover plate 150 includes, but is not limited to, mechanical sealing or welding sealing. In this embodiment, the cover plate 150 is sealed and plugged on the opening 113 by means of mechanical sealing.

[0049] Please see Figures 1 to 9The electrode post 130 is riveted and fixed to the end wall 111 and electrically connected to the electrode assembly 120. The electrode post 130 can be riveted and fixed to the end wall 111 by internal riveting or external riveting. In this embodiment, the electrode post 130 is riveted internally. Specifically, the end wall 111 is provided with an electrode post hole 1111, and the electrode post 130 is installed through the electrode post hole 1111 and is insulated from the end wall 111. The end of the electrode post 130 facing the electrode assembly 120 passes through the end wall 111 and is directly electrically connected to the positive electrode tab 125 or indirectly connected by an adapter. The structure of the electrode post 130 can be any suitable form that can pass through the end wall 111 and be electrically connected to the positive electrode tab 125 of the electrode assembly 120. For example, the cross-section can be circular, square, prismatic, or an irregular contour that can achieve stable conductivity. The shape of the electrode post hole 1111 corresponds to the shape of the electrode post 130. In this embodiment, the cross-section of the electrode post 130 is circular.

[0050] Please see Figures 3 to 6 The pole post 130 includes a columnar portion 131, an outer flange 132, and an inner flange 133. The columnar portion 131 penetrates the pole post hole 1111. The cross-section of the columnar portion 131 can be circular, square, prismatic, or other irregular contours that can achieve stable conductivity. Considering better sealing and fitting effects, preferably, the columnar portion 131 is adapted to the pole post hole 1111, that is, the shape of the pole post hole 1111 corresponds to that of the columnar portion 131. In this embodiment, the cross-section of the columnar portion 131 is circular. The circular design facilitates processing, assembly, and sealing.

[0051] Please see Figures 3 to 6 The outer flange 132 is located outside the housing 110 and extends from the pole hole 1111 to the outer periphery of the end wall 111. The cross-section of the outer flange 132 can be circular, square, prismatic, or other irregular shapes that can achieve stable conductivity, and there is no limitation thereto. The inner flange 133 is located inside the housing 110 and extends from the pole hole 1111 to the outer periphery of the end wall 111. Specifically, the inner flange 133 is formed by a 90-degree flange at the end of the original columnar portion 131 located inside the housing 110, and extends along the pole hole 1111 to the outer periphery of the end wall 111. The cross-section of the inner flange 133 can be circular, square, prismatic, or other irregular shapes that can achieve stable conductivity, and there is no limitation thereto.

[0052] Please see Figures 3 to 6The sealed insulation assembly 140 includes an inner plastic 141, a seal 142, and an outer plastic 143. The inner plastic 141 is located on the side of the end wall 111 facing the electrode assembly 120, and surrounds the columnar portion 131. The material of the inner plastic 141 is any one of soluble polytetrafluoroethylene (PFA), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), PP, polyphenylene sulfide (PPS), and polycarbonate (PC), and there is no limitation on this. The inner plastic 141 includes a fourth plastic portion 1411 and a fifth plastic portion 1412. The fourth plastic portion 1411 and the fifth plastic portion 1412 can be integrally molded or have separate structures. Specifically, in this embodiment, the fourth plastic portion 1411 and the fifth plastic portion 1412 are integrally molded. The fourth plastic portion 1411 is disposed around the electrode post hole 1111. A portion of the fourth plastic portion 1411 is along the thickness direction of the end wall 111, isolating the columnar portion 131 from the sidewall of the electrode post hole 1111 of the end wall 111. The remaining portion of the fourth plastic portion 1411 is located on the surface of the end wall 111 facing the electrode assembly 120, inside the housing 110, and extends from the electrode post hole 1111 towards the outer periphery of the end wall 111 to isolate the inner flange 133 from the end wall 111. The fifth plastic part 1412 extends from the electrode hole 1111 to the outer periphery of the end wall 111, isolating the end wall 111 from the electrode assembly 120, forming an all-round isolation to avoid electrical contact between the electrode 130 and the housing 110.

[0053] Please see Figures 3 to 9A sealing element 142 is disposed around the outer flange 132 and the end wall 111. The sealing element 142 can be an annular plate structure, a labyrinth structure, a ring structure, etc., but is not limited thereto. The inner annular sidewall of the sealing element 142 can surround and fit the inner plastic 141 protruding from the pole hole 1111, and the inner annular sidewall of the sealing element 142 can also surround and fit the columnar portion 131, as long as the insulation isolation between the columnar portion 131 and the end wall 111 is satisfied. Specifically, in this embodiment, the sealing element 142 is an annular plate structure, the inner annular sidewall of the sealing element 142 fits the outer sidewall of the columnar portion 131, and at the same time, one end face of the fourth plastic portion 1411 of the inner plastic 141 fits the surface of the sealing element 142, thereby avoiding gaps between the columnar portion 131 and the end wall 111 and ensuring insulation. Meanwhile, the fourth plastic portion 1411, along the thickness direction of the end wall 111, is sandwiched between the inner flange 133 and the seal 142. When the inner flange 133 is flanged and riveted, the elastic deformation of the seal 142 buffers the impact, reducing the probability of the fourth plastic portion 1411 being crushed. The seal 142 is made of an elastic material, such as EPDM rubber, fluorosilicone rubber, or fluororubber, but is not limited to these. In this embodiment, the seal 142 is made of fluororubber.

[0054] Please see Figures 3 to 6 The outer plastic 143 is located at the outer edge of the outer flange 132, used to increase the surface insulation path length between the outer flange 132 and the end wall 111, and to provide mechanical protection for the outer flange 132. The outer plastic 143 can be made of PP, PPS, PC, PFA, PBT, and LCP, or the same material as the seal 142, such as EPDM rubber, fluorosilicone rubber, or fluororubber, but is not limited thereto. The outer plastic 143 includes a first plastic portion 1431 and a second plastic portion 1432, which are integrally formed in an L-shape. The first plastic portion 1431 surrounds the outer periphery of the outer flange 132, extending the insulation path between the housing 110 and the outer surface of the outer flange 132, increasing the surface creepage distance between the end wall 111 and the outer flange 132, and reducing the risk of battery short circuits. The second plastic part 1432 extends from the first plastic part 1431 toward the pole hole 1111. The second plastic part 1432 is disposed between the end wall 111 and the outer flange 132. The second plastic part 1432 is sandwiched between the outer plastic 143 and the end wall 111. The outer plastic 143 and the end wall 111 do not directly contact each other, so as to realize the installation and fixation of the outer plastic 143.

[0055] Along the thickness direction of the end wall 111, the projections of the outer plastic part 143 and the seal 142 on the end wall 111 at least partially overlap, thereby forming an overlap area between the second plastic part 1432 and the seal 142. The overlap area between the second plastic part 1432 and the seal 142 is not limited; it can be any suitable size area that isolates the outer plastic part 143 from the end wall 111 and can be clamped by the seal 142 and the outer flange 132, fixing the outer plastic part 143 to the outside of the outer flange 132. The seal 142 isolates the outer plastic part 143 from the end wall 111, ensuring no contact area between the outer plastic part 143 and the end wall 111. Since the seal 142 isolates the end wall 111 and the outer plastic 143, pressure is generated on the end wall 111 during the riveting process of the inner flange 133. The seal 142 is an elastic element and can undergo elastic deformation. At the same time, the seal 142 is sandwiched between the end wall 111 and the outer plastic 143, which can absorb most of the extrusion energy from the housing 110. The outer plastic 143 does not need to directly bear the extrusion from the end wall 111, reducing the deformation of the outer plastic 143 and thus reducing the probability of the outer plastic 143 being crushed or falling off, thereby avoiding the risk of short circuit caused by contact between the pole post 130 and the housing 110. At the same time, since the deformation of the outer plastic 143 is reduced, compared with the material of the inner plastic 141, a material with a lower elongation at break can be used to make the outer plastic 143, thereby reducing production costs.

[0056] Please see Figure 5 and Figure 6 The seal 142 and the outer plastic 143 can be an integral structure or a separate structure. In one example of the secondary battery of this utility model, the seal 142 and the outer plastic 143 are separate structures. Compared with the integral structure design, the separate structure design of the seal 142 and the outer plastic 143 has a smaller direct impact on the outer plastic 143 when the seal 142 is deformed by external force, further reducing the probability of the seal 142 falling off or being crushed by the outer plastic. At the same time, the separate structure is more conducive to ensuring the reliability of the sealing and insulation between the terminal 130 and the shell 110, effectively preventing the terminal 130 from shifting or deforming during long-term use, and still maintaining good sealing and insulation performance.

[0057] Please see Figure 5 and Figure 6In one example of the secondary battery of this utility model, the outer flange 132 includes a first notch 1321 facing the end wall 111 on its radially outer side. The first notch 1321 serves as a receiving cavity for the second plastic part 1432, with at least a portion of the second plastic part 1432 accommodated within the first notch 1321, forming a stepped structure on the radially outer side of the outer flange 132. At least a portion of the sealing member 142 overlaps with the second plastic part 1432 located within the first notch 1321. The sealing member 142 is sandwiched between the outer flange 132 and the end wall 111 to seal and isolate a portion of the columnar portion 131 of the electrode post 130, a portion of the outer flange 132, and the end wall 111, preventing electrical connection between the end wall 111 and the electrode post 130. The outer flange 132 at the first notch 1321 and the sealing member 142 form a clamping structure, clamping and fixing the second plastic part 1432 located within the first notch 1321, thereby achieving the assembly of the outer plastic part 143 on the outer side of the outer flange 132. The sealing element 142 and the outer plastic 143 form a stacked structure. The cooperation between the sealing element 142 and the outer plastic 143 can achieve sealing and insulation between the outer side of the end wall 111 and the outer flange 132, and also eliminate the contact area between the outer plastic 143 and the housing 110. This reduces the probability of the outer plastic 143 being crushed or falling off during the riveting process of the terminal post 130, thus reducing the risk of battery short circuit. The design of the first notch 1321 reduces the thickness of the outer flange 132 and, given the limited height of the terminal post 130, reduces the proportion of the terminal post 130 located outside the housing 110 in the overall battery space, ensuring the battery's capacity density and energy density, and improving the battery's space utilization.

[0058] For further details, please refer to Figure 6 The side of the second plastic part 1432 facing the axis of the pole post 130 is attached to the pole post 130, so that the surface of the second plastic part 1432 facing the seal 142 and the surface of the outer flange 132 attached to the seal 142 are connected. Even if the second plastic part 1432 completely fills the first gap 1321, it avoids the seal 142 being squeezed and deformed. The presence of the gap will push the second plastic part 1432, reducing the probability of the outer plastic 143 falling off.

[0059] Please see Figure 7In one example of the secondary battery of this utility model, along the axis of the terminal post 130 towards the outer periphery of the end wall 111, the edge of the sealing member 142 extends beyond the edge of the outer plastic 143. Specifically, in this embodiment, the sealing surface of the sealing member 142 is enlarged, so that the sealing surface of the sealing member 142 extends beyond the outer edge of the outer plastic 143, and the surface of the outer plastic 143 that is in contact with the sealing member 142 completely overlaps the surface of the sealing member 142, increasing the overlap area between the outer plastic 143 and the sealing member 142 and enhancing the sealing effect of the sealing member 142. At the same time, when the second plastic part 1432 of the outer plastic 143 is sandwiched between the sealing member 142 and the outer flange 132, the stability of the assembly of the outer plastic 143 is improved, further reducing the probability of the outer plastic 143 falling off.

[0060] Please see Figure 5 and Figure 6 In one example of the secondary battery of this utility model, along the axis of the terminal post 130 towards the outer periphery of the end wall 111, the edge of the outer plastic 143 extends beyond the edge of the seal 142. Specifically, in this embodiment, the seal 142 partially overlaps with the second plastic part 1432, and the edge of the seal 142 does not extend beyond the outer wall of the first plastic part 1431. This hides the seal 142 within the interlayer area between the outer plastic 143 and the end wall 111, reducing the significant color difference between the seal 142 and the outer plastic 143 that affects the aesthetics of the battery, making the battery appearance cleaner and more beautiful. Simultaneously, since the seal 142 is made of an elastic material, and is hidden between the outer plastic 143 and the end wall 111, it can also slow down the aging rate of the seal 142 and reduce the probability of damage due to partial exposure of the seal 142, thus extending the battery's service life.

[0061] Please see Figure 6 and Figure 7In one example of the secondary battery of this utility model, the terminal post 130 further includes a groove 134 and a sealing pin 135. The groove 134 is formed on the outside of the terminal post 130, and the sealing pin 135 covers the opening of the groove 134, with a portion of the sealing pin 135 accommodated in the groove. The outer side of the sealing pin 135 overlaps with the outer flange 132, and welding is performed at the overlap area between the sealing pin 135 and the outer flange 132, thus welding the sealing pin 135 and the outer flange 132 together. In this embodiment, the sealing pin 135 and the outer flange 132 are connected and fixed by laser welding. To prevent the edge of the outer flange 132 from warping due to thermal expansion and contraction during welding, the outer flange 132 at the welding position with the sealing pin 135 is thickened. Along the thickness direction of the end wall 111, the thickness of the outer flange 132 at this welding position is denoted as T, with a value range of 1mm ≤ T ≤ 3mm. Understandably, the minimum thickness requirement for the outer flange 132 at this welding location is no less than 1mm, and the maximum thickness requirement is no more than 3mm. For example, the thickness of the outer flange 132 at this welding location can be any one of 1mm, 1.5mm, 1.8mm, 2mm, 2.4mm, or 3mm. By limiting the thickness of the outer flange 132 at the welding location to no less than 1mm, the overall rigidity and strength requirements of the outer flange 132 are met, and the resistance of the outer flange 132 to changes in thermal stress during welding is improved, thus preventing the edge of the outer flange 132 from warping due to thermal expansion and contraction during welding. By limiting the thickness of the outer flange 132 at the welding location to no more than 3mm, the overall height of the electrode post 130 is controlled, reducing the proportion of the electrode post 130 located outside the housing 110 in the entire battery space, ensuring the battery's capacity density and energy density, and improving the battery's space utilization rate.

[0062] Please see Figure 8 and Figure 9 In one example of the secondary battery of this utility model, the sealing element 142 and the outer plastic 143 adopt an integrated structural design, and the material of the outer plastic 143 is the same as that of the sealing element 142. In this embodiment, the outer plastic 143 uses the same elastic material as the sealing element 142, such as EPDM rubber, fluorosilicone rubber, or fluororubber, but is not limited to these. The integrated structure design of the sealing element 142 and the outer plastic 143 isolates the end wall 111 and the outer flange 132, and covers the side of the outer flange 132 away from the axis of the terminal post 130, providing better sealing and isolation effects, further avoiding electrical contact between the end wall 111 and the outer flange 132, and reducing the risk of battery leakage and short circuit. At the same time, the integrated structural design reduces the number of components and assembly steps, improves production efficiency, and reduces costs.

[0063] The specific structure of the integral seal 142 and the outer plastic 143 is not limited; it can be any suitable structural type that isolates the end wall 111 and the outer flange 132 and covers and fixes the outer side wall of the outer flange 132. Specifically, in this embodiment, the integral structure is a concave covering structure; please refer to [reference needed]. Figure 8 and Figure 9 The integrated sealing element 142 and outer plastic 143 include a sealing element 142, a second plastic portion 1432, a first plastic portion 1431, and a third plastic portion 1433. The sealing element 142 and the second plastic portion 1432 are integrally sandwiched between the end wall 111 and the outer flange 132. The first plastic portion 1431 is located on the side of the outer flange 132 opposite to the axis of the terminal post 130. The third plastic portion 1433 is located on the outer side of the terminal post 130, extending from the first plastic portion 1431 towards the terminal post hole 1111. The third plastic portion 1433 can cooperate with the first plastic portion 1431 and the second plastic portion 1432 to form a groove covering structure, covering the outer periphery of the outer flange 132, enabling rapid assembly and fixation of the sealing and insulating component 140 on the outer flange, improving battery assembly speed and efficiency. The area of ​​the surface of the third plastic part 1433 covering the outer flange 132 is not limited, but it is necessary to ensure that the surface of the outer flange 132 has sufficient metal area to ensure electrical connection between batteries.

[0064] For further details, please refer to Figure 9 The outer flange 132 radially outward includes a second notch 1322 facing away from the end wall 111, and at least a portion of the third plastic portion 1433 is accommodated within the second notch 1322. The design of the second notch 1322 reduces the proportion of the terminal post 130 located outside the housing 110 in the overall battery space, even with limited height, thus ensuring battery capacity density and energy density and improving space utilization. The third plastic portion 1433 increases the surface creepage distance between the end wall 111 and the outer flange 132 based on the first plastic portion 1431, further reducing the probability of electrical contact between the end wall 111 and the terminal post 130, and improving the battery's insulation performance and safety.

[0065] Please see Figure 10 This utility model also provides an electronic device 1, which includes a battery pack 10. Please refer to [link / reference]. Figure 8The battery pack 10 includes any of the aforementioned secondary batteries 100. In one embodiment of the battery pack 10 of this utility model, the battery pack 10 includes a housing 101, a cover 102, and multiple secondary batteries 100. The multiple secondary batteries 100 are placed in the housing 101 and are connected in series or in parallel, or a combination of series and parallel connections. The cover 102 seals the housing 101 to protect the multiple secondary batteries 100. It should be noted that, in addition to the secondary batteries 100 of this utility model, the battery pack 10 may also include a battery pack thermal management system, circuit boards, etc. The battery pack 10 can be a battery module, a battery pack, an energy storage cabinet, etc.; these will not be described in detail here.

[0066] Further, please refer to Figure 11 The working part 11 is electrically connected to the battery pack 10 to obtain electrical power. As an example, the electronic device 1 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 11 is the vehicle body, and the battery pack 10 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 1 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 11 can be a unit component capable of obtaining electrical power from the battery pack 10 and performing corresponding tasks, 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 1.

[0067] This utility model relates to a secondary battery where a sealing element isolates the outer plastic from the end wall. The projections of the outer plastic and the sealing element onto the end wall at least partially overlap, forming an overlapping area to increase the sealing surface of the sealing element and enhance the sealing effect between the end wall and the terminal. Simultaneously, the sealing element isolates the outer plastic from the end wall, allowing the sealing element to absorb most of the compressive energy from the casing during the entire riveting process. The outer plastic does not directly bear the pressure from the end wall, reducing deformation and thus lowering the probability of it being crushed or detached, thereby avoiding the risk of short circuits caused by contact between the terminal and the casing. The first plastic portion extends the surface insulation path between the casing and the outer surface of the terminal, increasing the surface creepage distance between them and further reducing the probability of electrical contact between the end wall and the terminal, improving the battery's insulation performance and safety. Furthermore, the outer plastic can be made from a material with low elongation at break, reducing production costs. Therefore, this utility model effectively overcomes some practical problems in the prior art, thus having high utilization value and practical significance. The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit its scope. Anyone skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A secondary battery, characterized in that, include: A housing, the housing including an end wall and a side wall surrounding the end wall, the end wall having an electrode post hole; Electrode assemblies are disposed within the housing; An electrode post is riveted to the end wall and electrically connected to the electrode assembly. The electrode post includes an outer flange located outside the housing and extending from the electrode post hole to the outer periphery of the end wall. A sealing element is disposed between the outer flange and the end wall; The outer plastic part includes a first plastic part and a second plastic part, wherein the first plastic part surrounds the outer periphery of the outer flange; the second plastic part extends from the first plastic part toward the pole hole; and the second plastic part is disposed between the end wall and the outer flange. Wherein, along the thickness direction of the end wall, the projection of the outer plastic and the sealing member on the end wall at least partially overlaps, and the sealing member isolates the outer plastic from the end wall.

2. The secondary battery according to claim 1, characterized in that, The sealing element and the outer plastic are separate structures.

3. The secondary battery according to claim 2, characterized in that, The outer radial side of the outer flange includes a first notch facing the end wall, at least a portion of the second plastic portion is accommodated within the first notch, and at least a portion of the seal overlaps the second plastic portion located at the first notch.

4. The secondary battery according to claim 2, characterized in that, Along the axis of the pole towards the outer periphery of the end wall, the edge of the seal extends beyond the edge of the outer plastic.

5. The secondary battery according to claim 2, characterized in that, Along the axis of the pole towards the outer periphery of the end wall, the edge of the outer plastic extends beyond the edge of the seal.

6. The secondary battery according to claim 1, characterized in that, The pole post also includes a groove and a sealing pin. The groove is formed on the outside of the pole post. The sealing pin overlaps and is welded to the outer flange, and at least a portion of the sealing pin is accommodated in the groove. The thickness of the outer flange at the welding position with the sealing pin is T, where 1mm ≤ T ≤ 3mm.

7. The secondary battery according to claim 1, characterized in that, The sealing element and the outer plastic are integrally molded. The integrally molded sealing element and the outer plastic isolate the end wall and the outer flange, and cover the side of the outer flange that is away from the pole axis.

8. The secondary battery according to claim 7, characterized in that, The integral seal and the outer plastic also include a third plastic portion, which extends from the first plastic portion toward the pole hole; the outer flange radially outward includes a second notch away from the end wall, and at least a portion of the third plastic portion is accommodated within the second notch.

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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