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, an insulating sealing element and lower plastic, the shell comprises an end wall, and a pole hole is formed in the end wall; the pole comprises a columnar part, an outer flange and an inner flange, the columnar part penetrates through the pole hole, the outer flange is located outside the shell and extends from the columnar part to the outer periphery of the end wall, and the inner flange is located in the shell and extends from the columnar part to the outer periphery of the end wall; the insulation sealing piece comprises an outer insulation part, a hole insulation part and an inner insulation part which are integrally formed, the outer insulation part is located between the outer flange and the end wall, the hole insulation part is located between the columnar part and the pole hole, and the inner insulation part is located between the inner flange and the end wall; the lower plastic is located on the side, facing the electrode assembly, of the end wall, and the lower plastic surrounds the columnar part; projections of the inner insulating part and the lower plastic on the end wall are at least partially overlapped, and the lower plastic isolates the electrode assembly and the end wall; the technical problem that the short circuit risk exists between the end wall and the current collecting component can be solved.

Description

Technical Field

[0001] The utility model relates to the field of batteries, and in particular to a secondary battery, a battery pack and an electronic device. Background Art

[0002] At present, cylinders are widely used in various industries because of their mature production technology, high yield rate, low processing cost, good safety performance and heat dissipation performance.

[0003] The end wall and electrode assembly of existing cylindrical batteries, as well as the end wall and the pole, are insulated by an insulating member. The insulating member is usually an integrated design. A lower plastic surrounding the insulating member is also provided between the end wall and the electrode assembly. There is a gap between the lower plastic and the insulating member. The existence of the gap will lead to the risk of short circuit between the end wall and the current collecting member. Utility Model Content

[0004] In view of the above shortcomings of the prior art, the utility model provides a secondary battery, a battery pack and an electronic device to improve the technical problem of the risk of short circuit between the end wall and the current collecting component.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a secondary battery, a battery pack and an electronic device, wherein the secondary battery comprises a shell, an electrode assembly, a pole, an insulating seal and a lower plastic; the shell comprises an end wall and a side wall surrounding the end wall, and the end wall is provided with a pole hole; the electrode assembly is arranged in the shell; the pole is fixed to the end wall and is electrically connected to the electrode assembly, and the pole comprises a columnar portion, an outer flange and an inner flange, the columnar portion passes through the pole hole, the outer flange is located outside the shell, and extends from the columnar portion to the outer periphery of the end wall The inner flange is located inside the shell and extends from the columnar portion to the outer periphery of the end wall; the insulating seal includes an integrally formed outer insulating portion, a hole insulating portion and an inner insulating 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 pole 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 the lower plastic surrounds the columnar portion; along the thickness direction of the end wall, the projections of the inner insulating portion and the lower plastic on the end wall at least partially overlap, and the lower plastic isolates the electrode assembly and the end wall.

[0006] In the above technical solution, the insulating seal is integrally formed and fully surrounds the pole hole, thereby improving the reliability of insulation between the pole and the end wall. Along the thickness direction of the end wall, the projections of the inner insulating part and the lower plastic on the end wall at least partially overlap, that is, the lower plastic and the inner insulating part at least partially overlap, so that there is no gap between the lower plastic and the inner insulating part, which can improve the technical problem of short circuit risk between the end wall and the current collecting component.

[0007] In an example of the secondary battery of the present invention, along the thickness direction of the end wall, the inner insulating part and the lower plastic overlap to form a lap joint, and the inner insulating part and / or the lower plastic includes a thinning structure for reducing the thickness of the lap joint.

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

[0009] In an example of a secondary battery of the utility model, the thinning structure includes a first step arranged on the outer periphery of the side of the inner insulating part facing the end wall, and the first step is recessed in a direction away from the end wall. The thinning structure also includes a second step arranged on the inner periphery of the side of the lower plastic facing the electrode assembly, and the second step is recessed in the direction of the end wall.

[0010] In the above technical solution, by setting a first step on the side of the inner insulating part facing the end wall to form a thinning area, the side of the inner insulating part close to the electrode assembly is a plane, which ensures the flatness of the inner flange pressing surface and improves the stability of the inner flange pressing; by setting a second step on the inner periphery of the lower plastic, on the one hand, the flatness of the overlap part is improved, and on the other hand, the space occupied by the overlap part in the height direction of the secondary battery is reduced. In addition, the second step of the lower plastic can be arranged relative to the first step of the inner insulating part, and the first step and the second step can limit each other, which can improve the centering of the inner insulating part and the lower plastic during assembly. On the other hand, the side of the lower plastic close to the end wall has better flatness, which further reduces the space occupied by the lower plastic in the height direction of the secondary battery. Furthermore, the lower plastic is pressed to the end wall by the inner insulating part, which can fix the lower plastic and no gap will be generated due to movement, which further improves the insulation effect of the lower plastic.

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

[0012] In the above technical solution, the gap is used as the positioning gap between the inner insulating part and the lower plastic in the assembly process. During assembly, the positioning tool cooperates with the positioning gap to play a positioning role, thereby improving the concentricity of the inner insulating part and the lower plastic, and improving the assembly efficiency and assembly quality. In addition, this setting can weaken the radial stress transmission generated on the lower plastic when the insulating seal is folded, improve the problem of warping of the lower plastic, and improve the assembly quality.

[0013] In an example of the secondary battery of the present invention, along the radial direction of the end wall, the distance of the gap between the inner edge of the first step and the outer edge of the second step 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, the lower limit of a is the minimum gap adapted by the jig, which can meet the processing requirements of the positioning tooling; the upper limit of a is set to 2mm, which can prevent the strength of the lower plastic from being reduced due to the excessive length of the cantilever, resulting in the problem of sagging of the outer periphery of the lower plastic.

[0015] In an example of the secondary battery of the present invention, the inner flange clamps one end of the inner insulating part and includes a buckle structure extending toward the end wall, and a receiving groove matching the buckle structure is provided on one side of the inner insulating part facing the inner flange.

[0016] In the above technical solution, this arrangement can reduce the transmission of the pole riveting force in the radial direction, increase the riveting strength, and reduce the risk of the pole flying out.

[0017] In an example of the secondary battery of the present invention, a sealing ring is further provided between the outer flange and the end wall, and the sealing ring surrounds the outer insulating portion.

[0018] In the above technical solution, the insulating seal is mainly used for insulation, has low sealing performance and poor long-term sealing reliability. Since the compression amount of the added sealing ring is large, the sealing effect is improved.

[0019] In an example of the secondary battery of the utility model, an upper plastic is arranged between the outer flange and the end wall, the upper plastic surrounds the sealing ring, a first avoidance structure is arranged on one side of the upper plastic close to the sealing ring, and a second avoidance structure is arranged on one side of the outer insulating part close to the sealing ring.

[0020] In the above technical solution, the first avoidance structure and the second avoidance structure are used to accommodate the sealing ring that is squeezed and deformed, which can further improve the sealing performance.

[0021] The utility model also provides a battery pack, which comprises any one of the above-mentioned secondary batteries.

[0022] The utility model also provides an electronic device, which comprises the battery pack mentioned above.

[0023] In the secondary battery of the utility model, the insulating seal is integrally formed and fully surrounds the pole hole, thereby improving the reliability of insulation between the pole and the end wall. Along the thickness direction of the end wall, the projections of the inner insulating part and the lower plastic on the end wall at least partially overlap, that is, the lower plastic and the inner insulating part at least partially overlap, so that there is no gap between the lower plastic and the inner insulating part, which can improve the technical problem of short circuit risk between the end wall and the current collecting component. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic structural diagram of an example of a secondary battery of the utility model;

[0026] Figure 2 This is a schematic diagram of the structure of an electrode assembly of an example of a secondary battery of the utility model;

[0027] Figure 3 for Figure 1 A partial enlarged view of A in an example of a secondary battery of the utility model;

[0028] Figure 4 for Figure 3 A partial enlarged view of point B in the middle;

[0029] Figure 5 for Figure 1 A partial enlarged view of A in another example of the secondary battery of the utility model;

[0030] Figure 6 for Figure 5 A partial enlarged view of point C in the middle;

[0031] Figure 7 A schematic diagram of an example of a battery pack of the utility model;

[0032] Figure 8 It is a schematic diagram of an example of the electronic device of the present invention.

[0033] Component number description

[0034] 1. Electronic device; 10. Battery pack; 11. Working part; 101. Box; 102. Box cover; 100. Secondary battery; 110. Shell; 111. End wall; 1111. Post hole; 112. Side wall; 113. Opening; 120. Electrode assembly; 121. Positive electrode sheet; 1211. Positive electrode current collector; 1212. First coating area; 1213. First uncoated area; 122. Separator; 123. Negative electrode sheet; 1231. Negative electrode current collector; 1232. Second coating area; 1233. Second uncoated area; 124. Negative electrode ear; 125, positive electrode ear; 130, cover plate; 140, pole; 141, inner flange; 142, columnar portion; 143, outer flange; 144, snap-fit ​​structure; 150, insulating seal; 151, outer insulating portion; 1511, second avoidance structure; 152, hole insulating portion; 153, inner insulating portion; 154, first step; 155, accommodating groove; 160, lower plastic; 161, second step; 170, overlapping portion; 171, thinning structure; 180, sealing ring; 190, upper plastic; 191, first avoidance structure. DETAILED DESCRIPTION

[0035] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and the features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific implementation schemes, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0036] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are in accordance with the prior art mastery of those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0037] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present utility model. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present utility model without substantially changing the technical content.

[0038] The secondary battery includes an electrode assembly, which is a component in the secondary battery where electrochemical reactions occur, and may include one or more electrode assemblies.

[0039] The secondary battery also includes a shell, a cover plate and a pole. The shell includes an end wall and a side wall surrounding the end wall. One end of the side wall has an opening. The electrode assembly can be assembled into the shell through the opening of the shell. The cover plate is used to cover the opening of the shell to achieve sealing. The pole passes through the end wall and is electrically connected to the electrode assembly to conduct the electrical energy generated by the electrode assembly.

[0040] In order to reduce the risk of short circuit, it is necessary to insulate and isolate the pole and end wall, and the electrode assembly and the end wall. The insulation of the pole and the end wall is usually achieved by sandwiching a sealed insulating part between the pole and the end wall, and the insulation between the electrode assembly and the end wall is usually achieved by setting a lower plastic part between the electrode assembly and the end wall.

[0041] In the related art, the lower plastic is arranged around the sealing insulating part, and there is a gap between the lower plastic and the insulating part. The existence of the gap will lead to the risk of short circuit between the end wall and the current collecting component, especially when the weight reduction hole is arranged in the positive electrode, the pole ear may be exposed from the weight reduction hole, and it may be warped up and contact the end wall during gas production, causing a short circuit.

[0042] In view of this, the utility model provides a technical solution, along the thickness direction of the end wall, the projections of the inner insulating part and the lower plastic on the end wall at least partially overlap, that is, the lower plastic and the inner insulating part at least partially overlap, so that there is no gap between the lower plastic and the inner insulating part, which can improve the technical problem of short circuit risk between the end wall and the current collecting component.

[0043] See also Figures 1 to 8 The utility model provides a secondary battery 100 , which includes a shell 110 , an electrode assembly 120 , a pole 140 , an insulating seal 150 and a lower plastic 160 .

[0044] See also Figure 1The shell 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 relationship can be formed, the connection between the end wall 111 and the side wall 112 can be achieved in a variety of ways, such as integral stamping, integral casting or split welding. The surrounding of the side wall 112 is not limited, and can be cylindrical or prismatic, or can be surrounded along any other closed loop contour that can match the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 is cylindrical and surrounds the outer edge of the end wall 111, and a circular opening 113 is formed at one end of the side wall 112 away from the end wall 111. A housing cavity is formed in the shell 110 surrounded by the end wall 111 and the side wall 112, which is used to accommodate the electrode assembly 120, the electrolyte and other necessary battery components. Specifically, the diameter of the shell 110 can be determined according to the specific size of the electrode assembly 120, such as 18mm, 21mm, 46mm, etc. The shell 110 may be made of a variety of 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 rust-proof material such as metal nickel may be plated on the surface of the shell 110.

[0045] See also Figure 1 to Figure 2 The electrode assembly 120 is disposed inside the housing 110. The electrode assembly 120 is a component where an electrochemical reaction occurs in the secondary battery 100. The housing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 includes a pole piece and a separator 122, which are wound to form a winding structure. Specifically, in this embodiment, the electrode assembly 120 includes a positive pole piece 121, a separator 122, and a negative pole piece 123 axially wound around the housing 110.

[0046] See also Figure 1 to Figure 2 The positive electrode sheet 121 includes a positive electrode collector 1211 and a positive electrode active material layer coated on the positive electrode collector 1211. A first coated area 1212 coated with the positive electrode active material layer and a first uncoated area 1213 not coated with the positive electrode active material layer are formed on the positive electrode collector 1211. The first coated area 1212 and the first uncoated area 1213 are arranged axially along the shell 110. The first uncoated area 1213 extends to the outside of the diaphragm 122 at one end in the height direction of the secondary battery 100, and is bent toward the axis of the shell 110 to form a stacked positive electrode ear 125.

[0047] See also Figure 1 to Figure 2The 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, and a second coating area 1232 coated with the negative electrode active material layer and a second uncoated area 1233 not coated with the negative electrode active material layer are formed on the negative electrode current collector 1231. The second coating area 1232 and the second uncoated area 1233 are arranged axially along the shell 110, and the second uncoated area 1233 extends to the outside of the diaphragm 122 toward the other end in the height direction of the secondary battery 100, and is bent toward the axis of the shell 110 to form a stacked negative electrode tab 124.

[0048] See also Figure 1 to Figure 2 , the diaphragm 122 is arranged between the positive electrode plate 121 and the negative electrode plate 123 to isolate the positive electrode active material layer and the negative electrode active material layer. Taking the lithium-ion secondary battery 100 as an example, the material of the positive electrode current collector 1211 can be aluminum, the positive electrode active material layer includes the positive electrode active material, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc. The material of the negative electrode current collector 1231 can be copper, the negative electrode active material layer includes the negative electrode active material, and the negative electrode active material can be carbon or silicon, etc. The base material of the diaphragm 122 can be polypropylene (PP for short) or polyethylene (PE for short), etc. In order to protect and insulate the battery cell, an insulating film can also be coated on the outside of the battery cell, and the insulating film can be synthesized by PP, PE, polyethylene terephthalate (PET for short), polyvinyl chloride (PVC for short) or other high molecular polymer materials.

[0049] See also Figure 1 and Figure 2 Further, the positive electrode tab 125 in the present invention faces the end wall 111 or the opening 113, and 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 pole 140 so that the pole 140 is positively charged, and the negative electrode tab 124 faces the opening 113, and the housing 110 is electrically connected to the negative electrode tab 124, so that it is negatively charged. However, in other embodiments, the negative electrode tab 124 can be connected to the pole 140, and the positive electrode tab 125 can be connected to the housing 110.

[0050] See also Figure 1 The cover plate 130 is sealed and installed on the opening 113; the outer edge shape of the cover plate 130 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 130 includes but is not limited to mechanical sealing or welding sealing. In this embodiment, the cover plate 130 is sealed and blocked on the opening 113 by mechanical sealing.

[0051] See also Figures 3 to 6 The pole 140 is fixed to the end wall 111 and electrically connected to the electrode assembly 120. Specifically, the end wall 111 is provided with a pole hole 1111. The pole 140 is installed through the pole hole 1111 and is insulated from the end wall 111. The end of the pole 140 facing the electrode assembly 120 passes through the end wall 111 to be directly electrically connected to the positive pole ear 125 or is electrically connected through an indirect transfer. The structure of the pole 140 can be any suitable form that can pass through the end wall 111 and be electrically connected to the positive pole ear 125 of the electrode assembly 120. For example, the cross-section can be circular, square, prismatic or a special-shaped profile that can achieve stable conductivity. The pole hole 1111 corresponds to the shape of the pole 140. In this embodiment, the cross-section of the pole 140 is circular.

[0052] See also Figures 3 to 6 The pole 140 includes a columnar portion 142, an outer flange 143 and an inner flange 141. The columnar portion 142 passes through the pole hole 1111. The cross-section of the columnar portion 142 can be circular, square, prismatic or other special-shaped contours that can achieve stable conduction. Considering the better sealing and matching effects, preferably, the columnar portion 142 is adapted to the pole hole 1111, that is, the shape of the pole hole 1111 corresponds to that of the columnar portion 142. In this embodiment, the cross-section of the columnar portion 142 is circular, and the circular design facilitates processing, assembly and sealing.

[0053] See also Figures 3 to 6 The outer flange 143 is located outside the shell 110 and extends from the columnar portion 142 to the outer periphery of the end wall 111. The outer cross-section of the outer flange 143 can be circular, square, prismatic or other special-shaped contours that can achieve stable conductivity, and there is no limitation on this. The inner flange 141 is located inside the shell 110 and extends from the columnar portion 142 to the outer periphery of the end wall 111. Specifically, the inner flange 141 connects one end of the columnar portion 142 located inside the shell 110, and extends along the side of the end wall 111 facing the inside of the shell 110 toward the outer edge of the end wall 111; the outer cross-section of the inner flange 141 can be circular, square, prismatic or other special-shaped contours that can achieve stable conductivity, and there is no limitation on this.

[0054] See also Figures 3 to 6The insulating seal 150 includes an integrally formed outer insulating portion 151, a hole insulating portion 152 and an inner insulating portion 153. The insulating seal 150 is made of any one of soluble polytetrafluoroethylene (Perfluoroalkoxy, PFA), polybutylene terephthalate (Polybutylene Terephthalate, PBT), liquid crystal polymer (Liquid Crystal Polymer, LCP), PP, polyphenylene sulfide (Polyphenylene Sulfide, PPS) and polycarbonate (Polycarbonate, PC), and is not limited thereto. 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 columnar portion 142 and the pole hole 1111, and the inner insulating portion 153 is located between the inner flange 141 and the end wall 111; the insulating seal 150 is integrally formed and fully surrounds the pole hole 1111, thereby improving the reliability of the insulation between the pole 140 and the end wall 111.

[0055] See also Figures 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 is any one of PP, PPS, PC, PFA, PBT and LCP, which is not limited. Furthermore, along the thickness direction of the end wall 111, the projections of the inner insulating part 153 and the lower plastic 160 on the end wall 111 at least partially overlap, and the lower plastic 160 isolates the electrode assembly 120 and the end wall 111, that is, the lower plastic 160 and the inner insulating part 153 at least partially overlap, and the overlapping method is not limited. For example, along the thickness direction of the end wall 111, the outer circle of the inner insulating part 153 is located between the end wall 111 and the lower plastic 160, or the inner circle of the lower plastic 160 can be located between the end wall 111 and the inner insulating part 153, or the outer circle of the inner insulating part 153 and the inner circle of the lower plastic 160 are connected by plugging. The above settings can make there is no gap between the lower plastic 160 and the inner insulating part 153, which can improve the technical problem of short circuit risk between the end wall 111 and the current collecting component.

[0056] See also Figure 3 and Figure 5 In an example of the secondary battery 100 of the present invention, along the thickness direction of the end wall 111, the inner insulating part 153 and the lower plastic 160 overlap to form a lap joint 170, and the inner insulating part 153 and / or the lower plastic 160 include a thinning structure 171 for reducing the thickness of the lap joint 170. The thinning structure 171 can reduce the thickness of the lap joint 170, which improves the flatness of the lap joint 170 on the one hand, and reduces the space occupied by the lap joint 170 in the height direction of the secondary battery 100 on the other hand.

[0057] See also Figure 3 and Figure 5 In an example of the secondary battery 100 of the utility model, the thinning structure 171 includes a first step 154 ​​arranged on the outer periphery of the side of the inner insulating part 153 facing the end wall 111, and the first step 154 ​​is recessed in the direction away from the end wall 111. By setting the first step 154 ​​to form a thinning area, the side of the inner insulating part 153 close to the electrode assembly 120 is a plane, which ensures the flatness of the pressing surface of the inner flange 141 and improves the stability of the pressing of the inner flange 141; the thinning structure 171 also includes an inner periphery arranged on the side of the lower plastic 160 facing the electrode assembly 120. The second step 161 is recessed toward the end wall 111. The second step 161 is provided to form a thinning area. On the one hand, the flatness of the overlapping portion 170 is improved. On the other hand, the space occupied by the overlapping portion 170 in the height direction of the secondary battery 100 is reduced. In addition, the second step 161 of the lower plastic 160 can be arranged opposite to the first step 154 ​​of the inner insulating portion 153. The first step 154 ​​and the second step 161 can limit each other, which can improve the centering of the inner insulating portion 153 and the lower plastic 160 during assembly. On the other hand, the side of the lower plastic 160 close to the end wall 111 has better flatness, which further reduces the space occupied by the lower plastic 160 in the height direction of the secondary battery 100. Furthermore, in this embodiment, the outer circle of the lower plastic 160 is located between the inner insulating portion 153 and the end wall 111, and the lower plastic 160 is pressed onto the end wall 111 by the inner insulating portion 153, which can fix the lower plastic 160 without generating a gap due to movement, thereby further improving the insulation effect of the lower plastic 160.

[0058] See also Figures 3 to 5 In an example of the secondary battery 100 of the utility model, the first step 154 ​​and the second step 161 overlap, and there is a gap 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. The above gap is used for the positioning gap between the inner insulating part 153 and the lower plastic 160 in the assembly process. During assembly, the positioning tool cooperates with the positioning gap to play a positioning role, improves the centering of the inner insulating part 153 and the lower plastic 160, and improves the assembly efficiency and assembly quality. In addition, this setting can weaken the radial stress transmission generated by the insulating seal 150 to the lower plastic 160 when it is folded, improves the problem of the lower plastic 160 warping, and improves the assembly quality.

[0059] See also Figure 3 to Figure 4In an example of the secondary battery 100 of the utility model, along the radial direction of the end wall 111, the distance of the gap between the inner edge of the first step 154 ​​and the outer edge of the second step 161 is a, where 0.2mm≤a≤2mm. The value of a can be 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, etc. The range of a is set to 0.2mm to 2mm, because the lower limit of a is the minimum gap adapted by the jig, which can meet the processing requirements of the positioning tooling; and the upper limit of a is set to 2mm, which can prevent the lower plastic 160 from reducing its strength due to the excessive cantilever, and the problem of sagging of the outer periphery of the lower plastic 160.

[0060] See also Figure 5 to Figure 6 In another example of the secondary battery 100 of the present invention, one end of the inner flange 141 clamping the inner insulating part 153 includes a buckle structure 144 extending toward the end wall 111, and a receiving groove 155 matching the buckle structure 144 is provided on the side of the inner insulating part 153 facing the inner flange 141. This arrangement can reduce the transmission of the riveting force of the pole 140 in the radial direction, increase the riveting strength, and reduce the risk of the pole 140 flying out.

[0061] See also Figures 3 to 5 In an example of the secondary battery 100 of the utility model, a sealing ring 180 is further provided between the outer flange 143 and the end wall 111, and the sealing ring 180 surrounds the outer insulating portion 151. The material of the sealing ring 180 can be EPDM rubber, fluorosilicone rubber or fluororubber, etc., but is not limited thereto. The insulating seal 150 is mainly used for insulation, has low sealing performance, and poor long-term sealing reliability. Due to the large compression amount of the sealing ring 180, the sealing effect can be improved.

[0062] See also Figure 3 to Figure 4In an example of the secondary battery 100 of the utility model, an upper plastic 190 is further provided between the outer flange 143 and the end wall 111. The material of the upper plastic 190 can be PP, PPS, PC, PFA, PBT and LCP, etc., which is not limited thereto. The upper plastic 190 surrounds the sealing ring 180. A first avoidance structure 191 is provided on the side of the upper plastic 190 close to the sealing ring 180, and a second avoidance structure 1511 is provided on the side of the outer insulating part 151 close to the sealing ring 180. The first avoidance structure 191 and the second avoidance structure 1511 are used to accommodate the squeezed and deformed sealing ring 180, which can further improve the sealing performance. The first avoidance structure 191 and the second avoidance structure 1511 are both arranged to be recessed in a direction away from the sealing ring 180. Preferably, the first avoidance structure 191 in the present embodiment is a groove formed by chamfering a side of the upper plastic 190 close to the end wall 111, and the second avoidance structure 1511 is a groove formed by chamfering a side of the outer insulating portion 151 close to the pole 140. The arrangement of the present embodiment enables the sealing ring 180 to overlap with the outer insulating portion 151 and the upper plastic 190 after being extruded and deformed, and to be pressed in sequence. In addition, the contact area between the sealing ring 180 and the outer flange 143, as well as the contact area between the sealing ring 180 and the end wall 111 are increased in the radial direction of the end wall 111, thereby further improving the sealing effect.

[0063] See also Figure 7 The utility model also provides a battery pack 10, the battery pack 10 includes any of the above-mentioned secondary batteries 100. In one embodiment of the battery pack 10 of the utility model, the battery pack 10 includes a box body 101, a box cover 102 and a plurality of secondary batteries 100. The plurality of secondary batteries 100 are placed in the box body 101, connected in series or in parallel, or in a mixture of series and parallel. The box cover 102 is sealed on the box body 101 to protect the plurality of secondary batteries 100. It should be noted that, in addition to the secondary battery 100 of the utility model, the battery pack 10 may also include a battery pack 10 thermal management system, a circuit board and other parts. The battery pack 10 may be a battery module, a battery pack, an energy storage cabinet, etc.; they will not be described one by one here.

[0064] See also Figure 8The utility model also provides an electronic device 1, which includes the above-mentioned battery pack 10. The working part 11 is electrically connected to the battery pack 10 to obtain power support. As an example, the electronic device 1 is a vehicle, and the vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc., but is not limited to this. The working part 11 is a vehicle body, and the battery pack 10 is arranged at the bottom of the vehicle body, and provides power support for the driving of the vehicle or the operation of electrical components in the vehicle. However, in some other embodiments, the electronic device 1 can also be a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy and an electric tool, etc. Spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc.; the working part 11 can be a unit component that can obtain the power of the battery pack 10 and perform corresponding work, such as a fan blade rotation unit, a vacuum cleaner dust removal unit, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The present application embodiment does not impose any special restrictions on the above-mentioned electronic device 1.

[0065] In the secondary battery of the utility model, the insulating seal is integrally formed and fully surrounds the pole hole, which improves the reliability of insulation between the pole and the end wall. Along the thickness direction of the end wall, the projections of the inner insulating part and the lower plastic on the end wall at least partially overlap, that is, the lower plastic and the inner insulating part at least partially overlap, so that there is no gap between the lower plastic and the inner insulating part, which can improve the technical problem of short circuit risk between the end wall and the current collecting component. Therefore, the utility model effectively overcomes some practical problems in the prior art and has high utilization value and use significance. The above embodiments are only illustrative of the principles and effects of the utility model, and are not used to limit the utility model. Anyone familiar with this technology can modify or change the above embodiments without violating the spirit and scope of the utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical ideas disclosed by the utility model should still be covered by the claims of the utility model.

Claims

1. A secondary battery, characterized in that: include: A shell, comprising an end wall and a side wall surrounding the end wall, wherein the end wall is provided with a pole hole; An electrode assembly is disposed in the housing; A pole, fixed to the end wall and electrically connected to the electrode assembly, the pole comprising a columnar portion, an outer flange and an inner flange, the columnar portion passing through the pole hole, the outer flange being located outside the shell and extending from the columnar portion to the outer periphery of the end wall, the inner flange being located inside the shell and extending from the columnar portion to the outer periphery of the end wall; An insulating seal, comprising an integrally formed outer insulating portion, a hole insulating portion and an inner insulating portion, wherein 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 pole hole, and the inner insulating portion is located between the inner flange and the end wall; A lower plastic, located on a side of the end wall facing the electrode assembly, the lower plastic surrounding the columnar portion; Wherein, along the thickness direction of the end wall, the projections of the inner insulating portion and the lower plastic on the end wall at least partially overlap, and the lower plastic isolates the electrode assembly from the end wall.

2. The secondary battery according to claim 1, characterized in that: Along the thickness direction of the end wall, the inner insulating portion and the lower plastic overlap to form an overlapping portion, and the inner insulating portion and / or the lower plastic includes a thinning structure for reducing the thickness of the overlapping portion.

3. The secondary battery according to claim 2, characterized in that: The thinning structure includes a first step arranged on the outer periphery of the side of the inner insulating portion facing the end wall, and the first step is recessed in a direction away from the end wall. The thinning structure also includes a second step arranged on the inner periphery of the side of the lower plastic facing the electrode assembly, and the second step is recessed in a direction toward the end wall.

4. The secondary battery according to claim 3, characterized in that: The first step and the second step overlap, and along the radial direction of the end wall, there is a gap between the inner edge of the first step and the outer edge of the second step.

5. The secondary battery according to claim 4, characterized in that: Along the radial direction of the end wall, the distance of the gap between the inner edge of the first step and the outer edge of the second step is a, wherein 0.2 mm≤a≤2 mm.

6. The secondary battery according to claim 1, characterized in that: The inner flange clamps one end of the inner insulating part and comprises a buckle structure extending toward the end wall, and a receiving groove matched with the buckle structure is provided on one side of the inner insulating part facing the inner flange.

7. The secondary battery according to claim 1, characterized in that: A sealing ring is further arranged between the outer flange and the end wall, and the sealing ring surrounds the outer insulating portion.

8. The secondary battery according to claim 7, characterized in that: An upper plastic is also arranged between the outer flange and the end wall, the upper plastic surrounds the sealing ring, a first avoidance structure is arranged on a side of the upper plastic close to the sealing ring, and a second avoidance structure is arranged on a side of the outer insulating part close to the sealing ring.

9. A battery pack, characterized in that: A secondary battery comprising the secondary battery according to any one of claims 1 to 8.

10. An electronic device, characterized in that: A battery pack comprising the battery pack of claim 9.

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