Secondary battery, battery pack and electronic device

Abstract

To provide a secondary battery capable of avoiding a risk of short circuit between a casing end wall and a current collecting structure.SOLUTION: The casing includes an end wall, and the end wall is provided with a terminal hole. The terminal includes a columnar portion, an outer flange 143 and an inner flange 141, the columnar portion 142 passes through the terminal hole, the outer flange is located outside the casing and extends from the columnar portion toward an outer periphery of the end wall, the inner flange is located inside the casing and includes the outer periphery 152 of the end wall and an inner insulating portion 153 from the columnar portion, the outer insulating portion is located between the outer flange and the end wall, the hole insulating portion is located between the columnar portion and the terminal hole, and the inner insulating portion is located between the inner flange and the end wall. The lower plastic 160 is located on the side of the end wall facing the electrode assembly, and the lower plastic surrounds the columnar part. Projections of the inner insulating part and the lower plastic on the end wall at least partially overlap, and the lower plastic isolates the electrode assembly from the end wall.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of batteries, and more particularly to a type of secondary battery, battery pack and electronic device. [Background technology]

[0002] At present, cylindrical filters have mature production processes, high yield rates, low processing costs, and good safety and heat dissipation performance, and are therefore widely used in various industries.

[0003] In known cylindrical batteries, the end walls and the electrode assemblies, and the end walls and the terminals are insulated by insulating members, which are usually one-piece designs with a bottom plastic surrounding the insulating member between the end walls and the electrode assemblies, and gaps exist between the bottom plastic and the insulating member, which creates a risk of short circuits between the end walls and the current collecting structures. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above-mentioned drawbacks of the prior art, the present invention provides a type of secondary battery to improve the technical problem of the short circuit risk existing between the end wall and the current collecting structure. [Means for solving the problem]

[0005] To achieve the above and other related objectives, the present invention provides a secondary battery. The secondary battery includes a casing, an electrode assembly, a terminal, an insulating seal, and a lower plastic. The casing includes an end wall and a side wall surrounding the end wall, with a terminal hole in the end wall. The electrode assembly is disposed within the casing. A terminal is fixed to the end wall and electrically connected to the electrode assembly. The terminal includes a post, an outer flange, and an inner flange. The post passes through the terminal hole, the outer flange is located outside the casing and extends from the post toward the outer edge of the end wall, and the inner flange is located inside the casing and extends from the post toward the outer edge of the end wall. The insulating seal includes an outer insulating portion, a hole insulating portion, and an inner insulating portion, which are integrally molded. The outer insulating portion is located between the outer flange and the end wall, the hole insulating portion is located between the post and the terminal hole, and the inner insulating portion is located between the inner flange and the end wall. The lower plastic is located on the side of the end wall facing the electrode assembly and surrounds the post. Along the thickness of the end wall, the inner insulation and the lower plastic at least partially overlap with their projections on the end wall, and the lower plastic separates the electrode assembly from the end wall.

[0006] In the above technical solution, the insulating seal member is installed by integral molding and has a full-circumference type around the terminal hole, improving the reliability of insulation between the terminal and the end wall. Along the thickness direction of the end wall, the projections of the inner insulating part and the lower plastic part on the end wall at least partially overlap, i.e., there is at least a partial overlap between the lower plastic part and the inner insulating part, and there is no gap between the lower plastic part and the inner insulating part, thereby improving the technical problem of the risk of short circuit between the end wall and the current collecting structure.

[0007] In one example of a secondary battery of the present invention, the inner insulating portion and the lower plastic overlap along the thickness direction of the end wall to form an overlapping portion, and the inner insulating portion and / or the lower plastic includes a thinned structure to reduce the thickness of the overlapping portion.

[0008] In the above-mentioned technical solution, the provision of a thin-walled structure can reduce the thickness of the overlapping portion, which on the one hand improves the flatness of the overlapping portion and on the other hand reduces the amount of space occupied by the overlapping portion in the height direction of the secondary battery.

[0009] In one example of the secondary battery of the present invention, the thinned structure includes a first step located on the outer periphery of the inner insulating part on the side facing the end wall, the first step being recessed in a direction away from the end wall, and the thinned structure further includes a second step located on the inner periphery of the lower plastic on the side facing the electrode assembly, the second step being recessed in a direction toward the end wall.

[0010] In the above technical solution, a first step is provided on the side of the inner insulating part facing the end wall to form a thinned region, making the side of the inner insulating part closer to the electrode assembly flat, ensuring the flatness of the pressing surface of the inner flange and improving the pressing stability of the inner flange. A second step is provided on the inner peripheral edge of the lower plastic part, which improves the flatness of the overlapping part on the one hand and reduces the amount of space the overlapping part occupies in the height direction of the secondary battery on the other hand. Furthermore, the second step of the lower plastic part can be positioned relative to the first step of the inner insulating part, so that the first and second steps can serve as positioning elements, improving the alignment of the inner insulating part and the lower plastic part during assembly. On the other hand, the side of the lower plastic part closer to the end wall has better flatness, further reducing the amount of space the lower plastic occupies in the height direction of the secondary battery. Furthermore, the lower plastic part is fixed by being pressed against the end wall by the inner insulating part, preventing gaps from reoccurring due to movement and further improving the insulating effect of the lower plastic part.

[0011] In one example of the secondary battery of the present invention, the first step and the second step overlap, and a gap exists between the inner edge of the first step and the outer edge of the second step along the radial direction of the end wall.

[0012] In the above technical solution, the gap is a gap for positioning the inner insulating part and the lower plastic during the assembly process, and during assembly, the positioning jig cooperates with this positioning gap to perform the positioning role, improving the alignment of the inner insulating part and the lower plastic, and improving the assembly efficiency and assembly quality. In addition, this setting reduces the radial stress transmission that occurs in the lower plastic when the insulating seal member is folded back, improving the problem of warping of the lower plastic and improving the assembly quality.

[0013] In one example of the secondary battery of the present invention, the gap distance between the inner edge of the first step and the outer edge of the second step along the radial direction of the end wall is a, where 0.2 mm≦a≦2 mm.

[0014] In the above technical solution, the range of a is set to 0.2mm~2mm, and the lower limit of a is the minimum gap that the jig can fit into, which can meet the processing requirements of the positioning jig. By setting the upper limit of a to 2mm, it is possible to prevent the strength of the lower plastic from being reduced due to the cantilever beam being too long, and to prevent the outer edge of the lower plastic from sagging.

[0015] In one example of a secondary battery of the present invention, one end of the inner flange that clamps the inner insulating portion includes a locking structure extending toward the end wall, and a receiving groove that cooperates with the locking structure is provided on the side of the inner insulating portion facing the inner flange.

[0016] In the above technical solution, this setting can reduce the radial transmission of the riveting force of the terminal, increase the riveting strength, and reduce the risk of the terminal popping out.

[0017] In one example of the secondary battery of the present invention, a seal ring is further disposed between the outer flange and the end wall, and the seal ring surrounds the outer insulation.

[0018] In the above technical solution, the insulating seal member is mainly used for insulation, and its sealing performance is relatively low, resulting in poor long-term sealing reliability. However, the added seal ring has a large compression amount, which improves the sealing effect.

[0019] In one example of a secondary battery of the present invention, an upper plastic is further installed between the outer flange and the end wall, the upper plastic surrounds a sealing ring, a first avoidance structure is installed on the side of the upper plastic closer to the sealing ring, and a second avoidance structure is installed on the side of the outer insulating part closer to the sealing ring.

[0020] In the above technical solution, the first and second avoidance structures are used to accommodate the compressively deformed seal ring, which can further improve the sealing performance.

[0021] The present invention further provides a battery pack, which includes any of the secondary batteries described above.

[0022] The present invention further provides an electronic device, which includes the battery pack described above. [Effects of the Invention]

[0023] In the secondary battery of the present invention, the insulating seal member is integrally molded and fully surrounds the terminal hole, improving the reliability of insulation between the terminal and the end wall. The projection of the inner insulating part and the lower plastic part onto the end wall at least partially overlaps along the thickness direction of the end wall, i.e., there is at least a partial overlap between the lower plastic part and the inner insulating part, preventing any gap between them. This improves the technical issue of the risk of short circuits between the end wall and the current collecting structure. [Brief explanation of the drawings]

[0024] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the drawings necessary for use in the description of the embodiments or related art are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application, and those skilled in the art can obtain other embodiments based on these drawings without expending creative efforts.

[0025] [Figure 1] 1 is a structural schematic diagram illustrating an example of a secondary battery of the present invention. [Figure 2] 1 is a structural schematic diagram of an exemplary electrode assembly of a secondary battery of the present invention. [Figure 3] FIG. 2 is a partially enlarged view of part A of an example of the secondary battery of the present invention in FIG. [Figure 4] FIG. 4 is a partial enlarged view of part B in FIG. 3. [Figure 5] 2 is a partially enlarged view of part A of another example of the secondary battery of the present invention in FIG. 1. FIG. [Figure 6] FIG. 6 is a partial enlarged view of part C in FIG. 5. [Figure 7] 1 is a schematic diagram of an example of a battery pack of the present invention. [Figure 8] 1 is a schematic diagram illustrating an example of an electronic device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments of the present invention will be described through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed herein. The present invention can be implemented or applied in further different specific embodiments, and the details of each item in this specification can be modified or changed in various ways based on different perspectives and applications without departing from the spirit of the present invention. It should be noted that the following examples and features in the examples can be combined with each other, where not inconsistent. It should also be understood that the terms used in the examples of the present invention are intended to describe specific embodiments and are not intended to limit the scope of protection of the present invention. In the following examples, test methods for which specific conditions are not noted generally follow general conditions or conditions recommended by each manufacturer.

[0027] When an example shows a range of values, it should be understood that the two endpoints of each range and any value between those two endpoints can be selected unless otherwise specified in the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention are based on the understanding of well-known techniques by those skilled in the art and the description of the present invention, and the present invention can also be realized using any methods, devices, and materials well-known in the art that are similar or equivalent to the methods, devices, and materials in the examples of the present invention.

[0028] As is well known, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are used for the convenience of clarifying the description and do not limit the scope of the present invention. Any change or adjustment of their relative relationships should be considered within the scope of the present invention unless there is a substantial change in the technical content.

[0029] A secondary battery includes an electrode assembly, which is the component where the electrochemical reaction occurs in the secondary battery, and can include one or more electrode assemblies.

[0030] The secondary battery further includes a casing, a cover plate, and a terminal. The casing includes an end wall and a side wall surrounding the end wall. One end of the side wall has an opening. The electrode assembly is assembled into the casing through the opening. The cover plate is used to cover the opening of the casing and achieve a seal. The terminal passes through the end wall and is electrically connected to the electrode assembly to conduct power generated by the electrode assembly.

[0031] To reduce the risk of short circuits, it is necessary to insulate and separate the terminals and end walls, and also the electrode assembly and end walls. The insulation between the terminals and end walls is usually achieved by sandwiching an insulating seal between the terminals and end walls, and the insulation between the electrode assembly and end walls is usually achieved by placing a bottom plastic between the electrode assembly and end walls.

[0032] In related art, the lower plastic is installed to surround the insulating seal member, and a gap exists between the lower plastic and the insulating member. The existence of this gap creates a risk of a short circuit between the end wall and the current collecting structure. In particular, if a reduction hole is provided in the positive electrode, the tab may be exposed through the reduction hole and bend upward during gas generation, contacting the end wall and causing a short circuit.

[0033] In view of this, the present invention provides a technical solution, which is to at least partially overlap the projections of the inner insulating part and the lower plastic part onto the end wall along the thickness direction of the end wall, i.e., at least partially overlap the lower plastic part and the inner insulating part, and no gap exists between the lower plastic part and the inner insulating part, thereby improving the technical problem of the risk of short circuit between the end wall and the current collecting structure.

[0034] Referring to FIGS. 1 to 8, the present invention provides a secondary battery 100, which includes a casing 110, an electrode assembly 120, a terminal 140, an insulating sealing member 150 and a lower plastic 160.

[0035] Referring to FIG. 1 , the casing 110 includes an end wall 111 and a side wall 112 surrounding the end wall 111. The connection between the end wall 111 and the side wall 112 can be realized in various ways, as long as a stable sealing performance and electrical connection can be formed. For example, this can be achieved by integral press molding, integral casting, or separate welding. The side wall 112 can be surrounded by a cylindrical or prismatic shape, or can be surrounded by any other closed loop contour that matches the end wall 111, but this is not limited to these. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 cylindrically surrounds the outer edge of the end wall 111, with a circular opening 113 formed at one end of the side wall 112 remote from the end wall 111. A cavity is formed within the casing 110, surrounded by the end wall 111 and the side wall 112, and is used to accommodate the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the diameter of the casing 110 can be determined based on the specific dimensions of the electrode assembly 120, and may be, for example, 18 mm, 21 mm, 46 mm, etc. The casing 110 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. To prevent the casing 110 from rusting during long-term use, the surface of the casing 110 may be coated with an anti-rust material such as metallic nickel.

[0036] 1 and 2, the electrode assembly 120 is installed inside the casing 110 and is a component where an electrochemical reaction occurs in the secondary battery 100. One or more electrode assemblies 120 may be included within the casing 110. The electrode assembly 120 includes a sheet and a separator 122, which are wound together 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 in the axial direction of the casing 110.

[0037] 1 and 2, the positive electrode sheet 121 includes a positive electrode current collector 1211 and a positive electrode active material layer coated on the positive electrode current collector 1211. A first coated region 1212 coated with the positive electrode active material layer and a first uncoated region 1213 not coated with the positive electrode active material layer are formed on the positive electrode current collector 1211. The first coated region 1212 and the first uncoated region 1213 are arranged along the axial direction of the casing 110, and the first uncoated region 1213 extends to the outside of the separator 122 at one end in the height direction of the secondary battery 100 and is bent toward the axis of the casing 110 to form a stacked positive electrode tab 125.

[0038] 1 and 2, the negative electrode sheet 123 includes a negative electrode current collector 1231 and a negative electrode active material layer coated on the negative electrode current collector 1231. A second coated region 1232 coated with the negative electrode active material layer and a second uncoated region 1233 not coated with the negative electrode active material layer are formed on the negative electrode current collector 1231. The second coated region 1232 and the second uncoated region 1233 are arranged along the axial direction of the casing 110, and the second uncoated region 1233 extends to the outside of the separator 122 at the other end in the height direction of the secondary battery 100 and is bent toward the axis of the casing 110 to form a stacked negative electrode tab 124.

[0039] 1 and 2, the separator 122 is disposed between the positive electrode sheet 121 and the negative electrode sheet 123 to separate the positive electrode active material layer from the negative electrode active material layer. Taking the lithium-ion secondary battery 100 as an example, the positive electrode current collector 1211 is made of aluminum, the positive electrode active material layer includes a positive electrode active material, such as lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode current collector 1231 is made of copper, and the negative electrode active material layer includes a negative electrode active material, such as carbon or silicon. The substrate material of the separator 122 is polypropylene (PP) or polyethylene (PE). To protect and insulate the battery cells, the outside of the battery cells can be coated with an insulating film, which can be made from PP, PE, polyethylene terephthalate (PET), polyvinyl chloride (PVC) or other high molecular weight polymer materials.

[0040] 1 and 2, in the present invention, when the positive electrode tab 125 faces the end wall 111 or the opening 113, the negative electrode tab 124 faces the other end of the casing 110. In this embodiment, the positive electrode tab 125 faces the end wall 111 and is electrically connected to the terminal 140, giving the terminal 140 a positive charge, and the negative electrode tab 124 faces the opening 113, giving the casing 110 a negative charge due to its electrical connection with the negative electrode tab 124. However, in other embodiments, the negative electrode tab 124 may be connected to the terminal 140, and the positive electrode tab 125 may be connected to the casing 110.

[0041] 1, the cover plate 130 is hermetically attached to the opening 113. The shape of the outer edge of the cover plate 130 corresponds to the shape of the opening 113 and connects with the side wall 112 to seal the opening 113. The attachment method of the cover plate 130 includes, but is not limited to, mechanical sealing or welding sealing. In this embodiment, the cover plate 130 hermetically closes the opening 113 by mechanical sealing.

[0042] 3 to 6 , the terminal 140 is fixed to the end wall 111 and electrically connected to the electrode assembly 120. Specifically, a terminal hole 1111 is provided in the end wall 111, and the terminal 140 is attached by penetrating through the terminal hole 1111 and is insulated from the end wall 111. One end of the terminal 140 facing the electrode assembly 120 penetrates the end wall 111 and is electrically connected to the positive electrode tab 125 directly or via an indirect intermediate connection. The structural form of the terminal 140 may be any suitable form that can penetrate the end wall 111 and electrically connect to the positive electrode tab 125 of the electrode assembly 120, for example, a cross section that is circular, square, prism-shaped, or a contoured shape that can achieve stable electrical conduction. The terminal hole 1111 corresponds to the shape of the terminal 140. In this embodiment, the cross section of the terminal 140 is circular.

[0043] 3 to 6, terminal 140 includes a post-shaped portion 142, an outer flange 143, and an inner flange 141. The post-shaped portion 142 penetrates a terminal hole 1111. The cross section of the post-shaped portion 142 may be circular, rectangular, prismatic, or have any other irregular contour that can achieve stable electrical conductivity. For better sealing and fitting effects, the post-shaped portion 142 is preferably matched with the terminal hole 1111. That is, the terminal hole 1111 corresponds to the shape of the post-shaped portion 142. In this embodiment, the cross section of the post-shaped portion 142 is circular, and the circular design is easy to process, assemble, and seal.

[0044] 3 to 6 , the outer flange 143 is located outside the casing 110 and extends from the columnar portion 142 toward the outer periphery of the end wall 111. The outer cross section of the outer flange 143 may be, but is not limited to, a circle, a square, a prism, or any other irregular shape that can achieve stable electrical conductivity. The inner flange 141 is located inside the casing 110 and extends from the columnar portion 142 toward the outer periphery of the end wall 111. Specifically, the inner flange 141 is connected to one end of the columnar portion 142 that is located inside the casing 110 and extends toward the outer edge of the end wall 111 along the side of the end wall 111 facing the inside of the casing 110. The outer cross section of the inner flange 141 may be, but is not limited to, a circle, a square, a prism, or any other irregular shape that can achieve stable electrical conductivity.

[0045] 3 to 6, the insulating seal member 150 includes an integrally molded outer insulating portion 151, a hole insulating portion 152, and an inner insulating portion 153. The insulating seal member 150 may be made of, but is not limited to, soluble polytetrafluoroethylene (PFA), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), PP, polyphenylene sulfide (PPS), or polycarbonate (PC). The outer insulating portion 151 is located between the outer flange 143 and the end wall 111, the hole insulating portion 152 is located between the column portion 142 and the terminal hole 1111, and the inner insulating portion 153 is located between the inner flange 141 and the end wall 111. The insulating seal member 150 is integrally formed and surrounds the entire terminal hole 1111, improving the reliability of insulation between the terminal 140 and the end wall 111.

[0046] 3 to 6 , the lower plastic 160 is located on the side of the end wall 111 facing the electrode assembly 120, and the lower plastic 160 surrounds the columnar portion 142. The material of the lower plastic 160 may be any one of PP, PPS, PC, PFA, PBT, and LCP, but is not limited thereto. Furthermore, the projections of the inner insulating portion 153 and the lower plastic 160 onto the end wall 111 at least partially overlap along the thickness direction of the end wall 111. The lower plastic 160 separates the electrode assembly 120 from the end wall 111, i.e., the lower plastic 160 and the inner insulating portion 153 at least partially overlap, and the manner of overlap is not limited thereto. For example, along the thickness direction of the end wall 111, the outer periphery of the inner insulating portion 153 may be located between the end wall 111 and the lower plastic 160, or the inner periphery of the lower plastic 160 may be located between the end wall 111 and the inner insulating portion 153. Alternatively, the connection may be achieved by using an insertion connection method between the outer periphery of the inner insulating part 153 and the inner periphery of the lower plastic 160. Either of the above configurations can eliminate any gap between the lower plastic 160 and the inner insulating part 153, thereby alleviating the technical problem of the risk of a short circuit between the end wall 111 and the current collecting structure.

[0047] 3 and 5 , in one example of the secondary battery 100 of the present invention, the inner insulating portion 153 and the lower plastic 160 overlap along the thickness direction of the end wall 111 to form an overlapping portion 170, and the inner insulating portion 153 and / or the lower plastic 160 includes a thinning structure 171 for reducing the thickness of the overlapping portion 170. The provision of the thinning structure 171 can reduce the thickness of the overlapping portion 170, which on the one hand improves the flatness of the overlapping portion 170 and on the other hand reduces the space occupied by the overlapping portion 170 in the height direction of the secondary battery 100.

[0048] 3 and 5 , in one example of the secondary battery 100 of the present invention, the thinned structure 171 includes a first step 154 ​​provided on the outer periphery of the side of the inner insulating part 153 facing the end wall 111. The first step 154 ​​is recessed away from the end wall 111. The provision of the first step 154 ​​forms a thinned region, making the side of the inner insulating part 153 closer to the electrode assembly 120 flat, thereby ensuring the flatness of the pressing surface of the inner flange 141 and improving the stability of pressing the inner flange 141. The thinned structure 171 further includes a second step 161 provided on the inner periphery of the side of the lower plastic 160 facing the electrode assembly 120. The second step 161 is recessed toward the end wall 111. The provision of the second step 161 forms a thinned region, which on the one hand improves the flatness of the overlapping part 170 and on the other hand reduces the space occupied by the overlapping part 170 in the height direction of the secondary battery 100. Furthermore, the second step 161 of the lower plastic 160 can be positioned relative to the first step 154 ​​of the inner insulating part 153, and the first step 154 ​​and the second step 161 can serve to position each other, improving the alignment of the inner insulating part 153 and the lower plastic 160 during assembly. On the other hand, the side of the lower plastic 160 closer to the end wall 111 can have better flatness, further reducing the space occupied by the lower plastic 160 in the height direction of the secondary battery 100. Furthermore, in this embodiment, the outer ring of the lower plastic 160 is located between the inner insulating part 153 and the end wall 111, and the lower plastic 160 is pressed against the end wall 111 by the inner insulating part 153, thereby fixing the lower plastic 160 and preventing gaps from moving, further improving the insulating effect of the lower plastic 160.

[0049] 3 to 5, in one example of the secondary battery 100 of the present invention, the first step 154 ​​and the second step 161 are overlapped, and a gap exists between the inner edge of the first step 154 ​​and the outer edge of the second step 161 along the radial direction of the end wall 111. This gap is used as a positioning gap in the assembly process of the inner insulating part 153 and the lower plastic part 160. During assembly, a positioning jig cooperates with this positioning gap to perform a positioning function, improving the alignment of the inner insulating part 153 and the lower plastic part 160 and improving assembly efficiency and assembly quality. Furthermore, this configuration reduces the radial stress transmission that occurs in the lower plastic part 160 when the insulating seal member 150 is folded back, alleviating the problem of warping of the lower plastic part 160 and improving assembly quality.

[0050] 3 and 4, in one example of the secondary battery 100 of the present invention, the gap distance between the inner edge of the first step 154 ​​and the outer edge of the second step 161 along the radial direction of the end wall 111 is a, where a satisfies 0.2 mm≦a≦2 mm. The value of a can be 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, etc. The reason for setting the range of a to 0.2 mm to 2 mm is that the lower limit of a is the minimum gap compatible with the jig and satisfies the processing requirements of the positioning jig. On the other hand, setting the upper limit of a to 2 mm prevents a decrease in strength of the lower plastic 160 due to an excessively long cantilever and prevents the outer edge of the lower plastic 160 from sagging.

[0051] 5 and 6, in another example of the secondary battery 100 of the present invention, one end of the inner flange 141 that holds the inner insulating part 153 includes a locking structure 144 that extends toward the end wall 111, and the side of the inner insulating part 153 that faces the inner flange 141 is provided with an accommodating groove 155 that cooperates with the locking structure 144. This configuration reduces the radial transmission of the riveting force of the terminal 140, increases the riveting strength, and reduces the risk of the terminal 140 popping out.

[0052] 3 to 5, in one example of the secondary battery 100 of the present invention, a seal ring 180 is further installed between the outer flange 143 and the end wall 111, and the seal ring 180 surrounds the outer insulating portion 151. The material of the seal ring 180 may be, but is not limited to, EPDM (tertiary ethylene propylene rubber), fluorine silicone rubber, or fluorine rubber. The insulating seal member 150 is mainly used for insulation and has relatively low sealing performance and lacks long-term sealing reliability, but the large compression amount of the seal ring 180 can improve the sealing effect.

[0053] 3 and 4, in one example of the secondary battery 100 of the present invention, an upper plastic 190 is further disposed between the outer flange 143 and the end wall 111. The material of the upper plastic 190 may be, but is not limited to, PP, PPS, PC, PFA, PBT, and LCP. The upper plastic 190 surrounds the seal ring 180. A first escape structure 191 is disposed on the side of the upper plastic 190 closest to the seal ring 180, and a second escape structure 1511 is disposed on the side of the outer insulating part 151 closest to the seal ring 180. The first escape structure 191 and the second escape structure 1511 are intended to accommodate the compressed and deformed seal ring 180, further improving sealing performance. Both the first escape structure 191 and the second escape structure 1511 are disposed as recesses formed in a direction away from the seal ring 180. Preferably, in this embodiment, the first avoidance structure 191 is a groove formed by chamfering the side of the upper plastic 190 closer to the end wall 111, and the second avoidance structure 1511 is a groove formed by chamfering the side of the outer insulating part 151 closer to the terminal 140. With this configuration, after the seal ring 180 is compressed and deformed, it overlaps with the outer insulating part 151 and the upper plastic 190, and they are successively brought into close contact with each other. In addition, the contact areas between the seal ring 180 and the outer flange 143 and between the seal ring 180 and the end wall 111 are increased along the radial direction of the end wall 111, both of which further improve the sealing effect.

[0054] 7, the present invention further provides a battery pack 10, which includes any of the secondary batteries 100 described above. In one embodiment of the battery pack 10 of the present invention, the battery pack 10 includes a case 101, a case cover 102, and a plurality of secondary batteries 100, the plurality of secondary batteries 100 being disposed within the case 101 and connected to each other in series, parallel, or a combination of series and parallel, and the case cover 102 covering the case 101 to protect the plurality of secondary batteries 100. It should be noted that the battery pack 10 may include components such as a thermal management system and a circuit board for the battery pack 10 in addition to the secondary battery 100 of the present invention, and the battery pack 10 may be a battery module, a battery pack, an energy storage cabinet, etc. This will not be described in further detail here.

[0055] Referring to FIG. 8 , the present invention further provides an electronic device 1, which includes the battery pack 10 described above. An actuator 11 is electrically connected to the battery pack 10 to receive power. For example, the electronic device 1 is a vehicle, which may be a gasoline-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be, but is not limited to, a pure electric vehicle, a hybrid vehicle, or a range-extended vehicle. The actuator 11 is a vehicle body, and the battery pack 10 is installed at the bottom of the body and provides power for driving the vehicle or operating electrical components inside the vehicle. However, in other embodiments, the electronic device 1 may be a mobile phone, a portable device, a laptop, a boat, space equipment, an electric toy, an electric tool, or the like. Space equipment includes airplanes, rockets, space shuttles, and spacecraft. The actuator 11 may be a unit component that receives power from the battery pack 10 and performs a corresponding operation, such as a blade rotation unit of an electric fan or a suction unit of a vacuum cleaner. The electric toys include stationary and mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys. The power tools include metal cutting power tools, polishing power tools, assembly power tools and railway power tools, such as power drills, power grinders, power wrenches, power screwdrivers, power hammers, impact drills, concrete vibrators and power planers, etc. The embodiments of the present invention do not impose any particular restrictions on the electronic device 1.

[0056] In the secondary battery of the present invention, the insulating seal member is integrally molded and completely surrounds the terminal hole, improving the reliability of insulation between the terminal and the end wall. The projection of the inner insulating portion onto the end wall of the lower plastic at least partially overlaps with the projection of the lower plastic on the end wall in the thickness direction, i.e., there is at least a partial overlap between the lower plastic and the inner insulating portion, eliminating any gap between the lower plastic and the inner insulating portion. This alleviates the technical problem of the risk of short circuits between the end wall and the current collecting structure. Therefore, the present invention effectively overcomes the practical problems in the known art and has high utility and practical significance. The above examples are merely illustrative of the principles and advantages of the present invention and are not intended to limit the present invention. Those skilled in the art may modify or alter the above examples without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or variations achieved by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention are still intended to be encompassed by the claims of the present invention. [Industrial Applicability]

[0057] The present invention provides a secondary battery, a battery pack, and an electronic device for improving the technical problem of the risk of short circuit between an end wall and a current collecting structure. [Explanation of symbols]

[0058] 1 Electronic equipment 10 Battery Pack 11. Operating unit 101 cases 102 Case Cover 100 Secondary battery 110 Casing 111 End Wall 1111 Terminal hole 112 Side wall 113 Aperture 120 Electrode Assembly 121 Positive electrode sheet 1211 Positive electrode current collector 1212 First application area 1213 First non-coated area 122 Separator 123 Negative electrode sheet 1231 Negative electrode current collector 1232 Second application area 1233 Second non-coating area 124 Negative electrode tab 125 Positive electrode tab 130 Lid plate 140 terminals 141 Inner flange 142 Columnar part 143 Outer flange 144 Locking structure 150 Insulating seal material 151 Outer insulation 1511 Second avoidance structure 152 hole insulation part 153 Inner insulation 154 First step 155 Storage groove 160 Lower Plastic 161 Second step 170 overlapping section 171 Thin structure 180 Seal Ring 190 Upper Plastic 191 First avoidance structure

Claims

1. a casing including an end wall and a side wall surrounding the end wall, the end wall having a terminal hole; an electrode assembly disposed within the casing; a terminal fixed to the end wall and electrically connected to the electrode assembly, the terminal including a post, an outer flange, and an inner flange, the post extending through the terminal hole, the outer flange located outside the casing and extending from the post toward the outer edge of the end wall, and the inner flange located inside the casing and extending from the post toward the outer edge of the end wall; an insulating seal member including an outer insulating portion, a hole insulating portion, and an inner insulating portion, which are integrally molded, the outer insulating portion being located between the outer flange and the end wall, the hole insulating portion being located between the columnar portion and the terminal hole, and the inner insulating portion being located between the inner flange and the end wall; a lower plastic portion located on the end wall facing the electrode assembly and surrounding the post. A secondary battery characterized in that the inner insulating portion and the projection of the lower plastic onto the end wall at least partially overlap along the thickness direction of the end wall, and the lower plastic separates the electrode assembly from the end wall.

2. 2. The secondary battery of claim 1, wherein the inner insulating portion and the lower plastic overlap to form an overlapping portion along the thickness direction of the end wall, and the inner insulating portion and / or the lower plastic includes a thin-walled structure to reduce the thickness of the overlapping portion.

3. the thinned structure includes a first step provided on an outer periphery of the inner insulating portion on a side facing the end wall, the first step being recessed in a direction away from the end wall; 3. The secondary battery of claim 2, wherein the thinned structure further includes a second step provided on an inner periphery of the lower plastic on the side facing the electrode assembly, the second step being recessed in a direction toward the end wall.

4. 4. The secondary battery according to claim 3, wherein the first step and the second step are overlapped, and a gap exists between an inner edge of the first step and an outer edge of the second step along the radial direction of the end wall.

5. 5. The secondary battery of claim 4, wherein the gap distance between the inner edge of the first step and the outer edge of the second step along the radial direction of the end wall is a, where 0.2 mm≦a≦2 mm.

6. 2. The secondary battery according to claim 1, wherein one end of the inner flange that clamps the inner insulating portion includes a locking structure extending in the end wall direction, and a housing groove that cooperates with the locking structure is provided on the side of the inner insulating portion facing the inner flange.

7. 2. The secondary battery according to claim 1, further comprising a seal ring disposed between the outer flange and the end wall, the seal ring surrounding the outer insulating portion.

8. A secondary battery as described in claim 7, characterized in that an upper plastic is further installed between the outer flange and the end wall, the upper plastic surrounds the sealing ring, a first avoidance structure is installed on the side of the upper plastic closer to the sealing ring, and a second avoidance structure is installed on the side of the outer insulating part closer to the sealing ring.

9. A battery pack comprising the secondary battery according to any one of claims 1 to 8.

10. An electronic device comprising the battery pack of claim 9.

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