Secondary battery, battery pack, and electrical device

Abstract

A secondary battery, a battery pack, and an electrical device, relating to the technical field of batteries. The secondary battery comprises a casing, an electrode assembly, and a top cover assembly. The casing has an accommodating cavity, and the electrode assembly is arranged in the accommodating cavity. The top cover assembly comprises a body (1), a pole (2), a clamping portion (3), and a plastic member (4). The body (1) is connected to the casing and seals the accommodating cavity, and the body (1) has a through hole (11). The pole (2) is inserted in the through hole (11), and the pole (2) comprises a first portion (21) and a second portion (22) which are arranged in a first direction. The first portion (21) comprises a first body portion (211), and the second portion (22) comprises a second body portion (221) and a flange (222) arranged around the second body portion (221). The first body portion (211) is at least connected to the second body portion (221). The clamping portion (3) is arranged around the first body portion (221) and is connected to the flange (222). A portion of the plastic member (4) is located in a mounting space (14), and the plastic member (4) is located between the clamping portion (3) and the body (1) and is separately connected to the clamping portion (3) and the body (1). By means of providing the clamping portion (3) connected to the first portion (21), the connection area of the first portion (21) is increased, and the possibility of separation between the first portion (21) and the second portion (22) is reduced.

Description

Secondary batteries, battery packs and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 4, 2024, with application number 202420404740.0 and application name “Secondary Batteries, Battery Packs and Electrical Equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery technology, and specifically relates to a battery pack and electrical equipment. Background Art

[0003] The composite pole comprises a first part and a second part which are composited with each other, and the first part and the second part are connected together by welding.

[0004] However, due to the limited connection area between the first part and the second part, there is a possibility that the connection between the first part and the second part will fail, thereby causing the first part to fall off and the secondary battery to fail. SUMMARY OF THE INVENTION

[0005] An embodiment of the present application provides a secondary battery, aiming to solve the problem of the first part of the composite electrode falling off.

[0006] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0007] In a first aspect, a secondary battery according to an embodiment of the present application includes:

[0008] a housing, wherein the housing has a receiving cavity;

[0009] an electrode assembly, the electrode assembly being disposed in the accommodating cavity;

[0010] A top cover assembly, comprising:

[0011] A body connected to the shell and covering the accommodating cavity, the body having a through hole;

[0012] The body has a groove on one side thereof away from or close to the electrode assembly along the first direction, and the groove surrounds the through hole;

[0013] a positioning structure, the positioning structure being connected to a side of the body that is away from or close to the electrode assembly along the first direction and surrounding the groove, the positioning structure and the body defining an installation space;

[0014] A pole, the pole being passed through the through hole, the pole having a first direction, the pole comprising a first portion and a second portion arranged along the first direction and passing through the through hole; the first portion comprising a first body portion, the second portion comprising a second body portion and a flange disposed around the second body portion, a portion of the flange being located in the installation space; the first body portion being connected to the second body portion;

[0015] a clamping portion, a portion of which is located in the installation space, the clamping portion being disposed around the first body portion and connected to the flange;

[0016] A plastic part, part of which is located in the installation space, is located between the clamping portion and the body and respectively connects the clamping portion and the body.

[0017] Optionally, the clamping portion has a first clamping surface and a first connecting surface which are opposite to each other in the first direction, and the first clamping surface is a surface of the clamping portion which is opposite to the electrode assembly;

[0018] The flange has a second clamping surface and a second connecting surface, the second clamping surface and the second connecting surface are opposite to each other, and the second clamping surface faces the electrode assembly;

[0019] The first connection surface and the second connection surface are connected.

[0020] Optionally, the pole has a second direction, and the pole has a maximum dimension D in the second direction, satisfying: 20 mm ≤ D ≤ 30 mm; wherein the first direction and the second direction intersect.

[0021] Optionally, the clamping portion has a maximum dimension H1 in the first direction, satisfying: 0mm

[0022] Optionally, the first portion has a maximum size H2 in the first direction, and the pole has a maximum size H3 in the first direction, satisfying: 0.6≤H2 / H3≤0.9.

[0023] Optionally, the clamping portion further has at least one first positioning surface, the first positioning surface is located between the first clamping surface and the first connecting surface, and the first clamping surface and the first connecting surface are respectively connected to the first positioning surface;

[0024] The flange further has at least one second positioning surface, and the second positioning surface is located and connected between the second clamping surface and the second connecting surface;

[0025] Wherein, the first positioning surface and the second positioning surface are flush and correspond one to one. ​

[0026] Optionally, the first portion has a first surface and a second surface facing away from each other in the first direction, the second surface faces the electrode assembly, and the second surface is connected to the second portion.

[0027] Optionally, the first portion further has a third surface, the third surface is located between the first surface and the second surface along the first direction, the third surface faces the electrode assembly, and the third surface is connected to the flange.

[0028] Optionally, the first portion further has a first circumferential surface, the first circumferential surface is located between the second surface and the third surface, the second surface and the third surface are respectively connected to the first circumferential surface, and the first circumferential surface is connected to the second portion.

[0029] Optionally, a rounded corner is provided between the first circumferential surface and the third surface.

[0030] Optionally, the radius of the rounded corner is R, satisfying: 2mm≤R≤7mm.

[0031] Optionally, the first portion has a first surface and a second surface facing away from each other in the first direction, the second surface faces the electrode assembly, and the second surface is connected to the second portion;

[0032] The first portion further has a fourth surface, the fourth surface being located between the first surface and the second surface along the first direction, the fourth surface facing away from the electrode assembly;

[0033] The first portion further has a second circumferential surface, the second circumferential surface is located between the first surface and the fourth surface, and the first surface and the fourth surface are respectively connected to the second circumferential surface;

[0034] The first portion further has a third circumferential surface, the third circumferential surface is located between the fourth surface and the first clamping surface, and the fourth surface and the first clamping surface are respectively connected to the third circumferential surface.

[0035] Optionally, the body has a groove on one side away from the electrode assembly along the first direction; the positioning structure is connected to the side of the body away from the electrode assembly in the first direction; the plastic part includes outer rubber and inner rubber, and the outer rubber part is located between the positioning structure and the first body part and connects the positioning structure, the first body part and the clamping part; the inner rubber is connected to the outer rubber, and the inner rubber part is located in the installation space and between the clamping part and the positioning structure and respectively connects the clamping part and the positioning structure.

[0036] In a second aspect, the present application also provides a battery pack comprising a secondary battery as described in any one of the above embodiments.

[0037] In a third aspect, the present application also provides an electrical device comprising a battery pack as described in any one of the above embodiments. Beneficial effects

[0038] The present application provides a secondary battery, which includes a shell, an electrode assembly and a top cover assembly, the shell having a accommodating cavity; the electrode assembly is arranged in the accommodating cavity; the top cover assembly includes a body, a pole, a clamping portion and a plastic part, the body is connected to the shell and covers the accommodating cavity, and the body has a through hole; the pole is passed through the through hole, the pole has a first direction, and the pole includes a first part and a second part arranged along the first direction; the first part includes a first body part, the second part includes a second body part and a flange arranged around the second body part; the first body part is connected to at least the second body part; the clamping portion is arranged around the first body part and is connected to the flange; part of the plastic part is located in the installation space, the plastic part is located between the clamping portion and the body and connects the clamping portion and the body respectively. The present application provides a clamping part connected to the first part, which can increase the connection area of ​​the first part, make the connection between the first part and the second part more stable, and reduce the possibility of separation of the first part and the second part. At the same time, since the clamping part can be clamped by the plastic part and the flange, the first part is not only limited by the second part but also by parts other than the second part, further preventing the first part and the second part from falling off.

[0039] In addition, the present application also provides a battery pack, which includes the above-mentioned secondary battery. Since the connection between the first part and the second part of the secondary battery is more stable, the battery pack has higher reliability.

[0040] In addition, the present application also provides an electrical device, which includes the above-mentioned battery pack. Since the battery pack has higher reliability, the reliability of the electrical device is also higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings used in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0042] FIG1 is a schematic structural diagram of a secondary battery electrode provided in an embodiment of the present application;

[0043] FIG2 is a top view of FIG1 ;

[0044] FIG3 is a bottom view of FIG1 ;

[0045] FIG4 is a schematic structural diagram of a top cover assembly of a secondary battery provided in an embodiment of the present application;

[0046] FIG. 5 is a detailed view of frame A in FIG. 4 .

[0047] Figure markings, 1-main body, 11-through hole, 12-positioning structure, 13-groove, 14-installation space, 2-pole, 21-first part, 211-first main body, 212-first surface, 213-second surface, 214-third surface, 215-first circumferential surface, 216-fourth surface, 217-second circumferential surface, 218-third circumferential surface, 22-second part, 221-second main body, 222-flange, 223-second clamping surface, 224-second connecting surface, 225-second positioning surface, 3-clamping part, 31-first clamping surface, 32-first connecting surface, 33-first positioning surface, 4-plastic part, 41-outer rubber bag, 42-inner rubber bag. Modes for Carrying Out the Invention

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly specified and specifically limited. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0050] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0051] The composite pole 2 includes a first portion 21 and a second portion 22 that are composited with each other. The first portion 21 and the second portion 22 are connected together by welding.

[0052] However, when the pole 2 is fixed to the body 1, the first part 21 is only constrained by the connection with the second part 22, and since the connection area between the first part 21 and the second part 22 is limited, the connection between the first part 21 and the second part 22 may fail, which may lead to the first part 21 falling off and the secondary battery failing.

[0053] A first embodiment of the present application provides a secondary battery. Please refer to Figures 1 and 5. Figure 1 is a schematic structural diagram of a pole 2 of a secondary battery provided in an embodiment of the present application. The secondary battery includes a housing, an electrode assembly, and a top cover assembly. The housing has a receiving cavity; the electrode assembly is disposed in the receiving cavity; the top cover assembly includes a body 1, a positioning structure 12, a pole 2, a clamping portion 3, and a plastic part 4. The body 1 is connected to the housing and covers the receiving cavity. The body 1 has a through hole 11; the body 1 has a groove 13 on one side away from or close to the electrode assembly along a first direction X, and the groove 13 surrounds the through hole 11; the positioning structure 12 is connected to one side of the body 1 away from or close to the electrode assembly along the first direction X and surrounds the groove 13. The positioning structure 12 and the body 1 define an installation space 14. The pole 2 is arranged in the through hole 11, and the pole 2 has a first direction X, which is the direction indicated by the X-axis in the figure. The pole 2 includes a first portion 21 and a second portion 22 arranged along the first direction X and extending through the through hole 11; the first portion 21 includes a first body portion 211, and the second portion 22 includes a second body portion 221 and a flange 222 arranged around the second body portion 221, and a portion of the flange 222 is located in the installation space 14; the first body portion 211 is connected to the second body portion 221; a portion of the clamping portion 3 is located in the installation space 14, the clamping portion 3 is arranged around the first body portion 211, and is connected to the flange 222; a portion of the plastic part 4 is located in the installation space 14, and the plastic part 4 is located between the clamping portion 3 and the body 1 and connects the clamping portion 3 and the body 1 respectively.

[0054] In the first embodiment of the present application, the clamping portion 3 connected to the first portion 21 is connected to the flange 222 of the second portion 22, thereby improving the ability of the second portion 22 to constrain and limit the first portion 21, thereby reducing the possibility of the first portion 21 and the second portion 22 being separated, and further reducing the possibility of secondary battery failure caused by the separation of the first portion 21 and the second portion 22. In addition, the clamping portion 3, as an extension of the first portion 21, can also be constrained and limited by sources other than the second portion 22, preventing the first portion 21 from moving away from the second portion 22, thereby reducing the possibility of the first portion 21 and the second portion 22 being separated, and further reducing the possibility of secondary battery failure caused by the separation of the first portion 21 and the second portion 22.

[0055] In some embodiments of the present application, the first portion 21 and the clamping portion 3 are made of aluminum, and the second portion 22 is made of copper. In some embodiments of the present application, the pole 2 is made of a copper-aluminum composite plate by cold heading; in other embodiments of the present application, the first portion 21 and the second portion 22 are formed separately and then welded together.

[0056] In some embodiments, please refer to Figure 1 again. The clamping portion 3 has a first clamping surface 31 and a first connecting surface 32 that are opposite to each other in the first direction X. The first clamping surface 31 is the surface of the clamping portion 3 that is opposite to the electrode assembly; the flange 222 has a second clamping surface 223 and a second connecting surface 224. The second clamping surface 223 and the second connecting surface 224 are opposite to each other, and the second clamping surface 223 faces the electrode assembly; wherein the first connecting surface 32 and the second connecting surface 224 are connected.

[0057] In the above embodiment, the first connecting surface 32 and the second connecting surface 224 are provided to achieve a surface connection between the clamping portion 3 and the flange 222. Furthermore, because the clamping portion 3 is connected to the first portion 21, the connection between the first portion 21 and the second portion 22 via the clamping portion 3 is further strengthened. The provision of the first clamping surface 31 and the second clamping surface 223 allows the pole 2 to be clamped and positioned in the first direction X. Furthermore, the first clamping surface 31 of the clamping portion 3 applies a force toward the second portion 22 to the first portion 21, thereby preventing the first portion 21 from falling away from the second portion 22 and improving the reliability of the pole 2.

[0058] The first connecting surface 32 and the second connecting surface 224 are completely aligned. In some embodiments of the present application, the first connecting surface 32 and the second connecting surface 224 are respectively planes; in other embodiments of the present application, the first connecting surface 32 and the second connecting surface 224 are respectively arcuate surfaces to increase the connection area between the clamping portion 3 and the flange 222.

[0059] Specifically, the distance between the first clamping surface 31 and the first surface 212 along the first direction X is greater than zero, so that when the clamping portion 3 is clamped, the first surface 212 can face away from the electrode assembly along the first direction X to expose the body 1, or the first surface 212 can be flush with the body 1, facilitating welding of the busbar. The second portion 22 has a fifth surface that faces away from the first surface 212 along the first direction X. The distance between the second clamping surface 223 and the fifth surface along the first direction X is greater than zero, so that when the flange 222 is clamped, the second portion 22 can face toward the electrode assembly along the first direction X to expose the body 1, facilitating welding of the second portion 22 to the connecting piece.

[0060] In some embodiments, please refer to Figures 2 and 3, where Figure 2 is a top view of Figure 1 and Figure 3 is a bottom view of Figure 1. The pole 2 has a second direction Y, which is the direction indicated by the Y axis in the figure. The pole 2 has a maximum dimension D in the second direction Y, satisfying: 20mm≤D≤30mm; wherein the first direction X and the second direction Y intersect.

[0061] In some embodiments, the first direction X and the second direction Y are perpendicular.

[0062] In the above embodiment, the maximum dimension D of the pole 2 in the second direction Y can be any one of 20.0 mm, 20.5 mm, 21.0 mm, 21.5 mm, 22.0 mm, 22.5 mm, 23.0 mm, 23.5 mm, 24.0 mm, 24.5 mm, 25.0 mm, 25.5 mm, 26.0 mm, 26.5 mm, 27.0 mm, 27.5 mm, 28.0 mm, 28.5 mm, 29.0 mm, 29.5 mm, and 30.0 mm, or a range between any two values. When the maximum dimension D of the pole 2 in the second direction Y is too large, the weight of the pole 2 will increase. Since the thickness of the clamping portion 3 and the flange 222 is relatively small, if D is too large, the strength of the clamping portion 3 and the flange 222 will decrease when subjected to force, and the connection between the clamping portion 3 and the flange 222 and the first portion 21 and the second portion 22 will be more likely to fail. If D is too small, the pole 2 will not be properly constrained and limited in the first direction X. When the maximum dimension D of the pole 2 in the second direction Y is too small, the first clamping surface 31 and the second clamping surface 223 are relatively small, and the pole 2 is likely to fall off from the body 1.

[0063] The following examples illustrate some embodiments. The top cover assembly is fixed, and a thrust is applied to the pole 2 until the pole 2 is broken. The thrust when the pole 2 is broken is recorded. The results when D takes different values ​​are as follows:

[0064]

[0065] In the above embodiments 1 and 2, the values ​​of D are 16 mm and 18 mm respectively, which are less than the lower limit of the value range. When the force applied by the push head on the pole 2 does not reach the 1500N required by the specification, the pole 2 will be separated from the body 1, and the top cover assembly will fail.

[0066] In Examples 3 to 5 above, the value of D was within the range of 20 mm to 30 mm. When the pusher applied a force of 1500 N to the terminal 2, the terminal 2 was not damaged, and the top cover assembly functioned normally. Furthermore, the closer the value of D was to the upper and lower limits of the range, the closer the force applied to the terminal 2, which would damage it, was to 1500 N.

[0067] In the above embodiments 6 and 7, the values ​​of D are 32 mm and 35 mm respectively, which are greater than the upper limit of the value range. When the force applied by the push head on the pole 2 does not reach the specification requirement of 1500 N, the pole 2 is damaged and the top cover assembly fails.

[0068] In some embodiments, referring to FIG. 1 again, the clamping portion 3 has a maximum dimension H1 in the first direction X, satisfying: 0 mm < H1 ≤ 1.0 mm.

[0069] In the above embodiment, the maximum dimension H1 of the clamping portion 3 in the first direction X can be any one of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, and 1.5 mm, or a range between any two of these values. When the maximum dimension H1 of the clamping portion 3 in the first direction X is too large, the thickness of the flange 222 along the first direction X is too small, resulting in poor mechanical properties at the flange 222. When the maximum dimension H1 of the clamping portion 3 in the first direction X is too small, the thickness of the flange 222 along the first direction X is too large. Furthermore, the flange 222 is part of the second portion 22, which is made of copper. Therefore, an increase in the thickness of the flange 222 will increase the weight of the pole 2.

[0070] The following examples illustrate a top cover assembly fixed to a tensile testing machine. A φ16 pusher is used to apply a thrust to the pole 2 until the pole 2 is broken. The thrust at which the pole 2 is broken is recorded. The results are as follows when H1 takes different values ​​and the dimension of the first clamping surface 31 and the second clamping surface 223 in the first direction X is 1.5 mm:

[0071]

[0072] In the above Examples 8 and 9, the values ​​of H1 are both greater than the upper limit of the value range. Although they can pass the test, when the value of H1 is greater than 1.0 mm, the thrust when the pole 2 is destroyed is very close to 1500 N. In order to provide a redundant value for the pole 2 during actual use and to have better reliability, H1 is not set to a value greater than 1.0 mm.

[0073] In Examples 10 and 11 above, the value of H1 was within the range of 0 mm to 1.0 mm. When the push head applied a force of 1500 N to the terminal 2, the terminal 2 was not damaged, and the top cover assembly functioned normally. Furthermore, the closer the value of H1 was to the upper limit of the range, the closer the force applied to the terminal 2, which would cause damage, was to 1500 N.

[0074] In the above embodiment 12, the value of H1 is 0 mm, which is less than the lower limit of the value range. Although it can pass the test, when the value of H1 is 0 mm, the clamping portion does not exist, that is, when the value of H1 is 0 mm, the technical problem of secondary battery failure caused by the falling off of the first portion 21 cannot be solved. Therefore, H1 is not 0 mm.

[0075] In some embodiments, referring again to FIG. 1 , the first portion 21 has a maximum dimension H2 in the first direction X, and the pole 2 has a maximum dimension H3 in the first direction X, satisfying: 0.6≤H2 / H3≤0.9.

[0076] In the above embodiment, when the value of H2 / H3 is too large, the thickness of the second portion 22 is too small, and the welding performance of the second portion 22 when welded to the tab cannot be guaranteed. Taking H3=6mm as an example, if H2 / H3>0.9, H2=5.5mm, the thickness between the fourth surface 216 and the fifth surface along the first direction X is only 0.5mm, and the welding penetration of the copper layer is 0.7mm, which affects the welding performance of the pole 2 when welded to the tab; if the value of H2 / H3 is too small, the thickness of the first portion 21 is too small, and the thickness between the fourth surface 216 and the fifth surface along the first direction X is too large. The material between the fourth surface 216 and the fifth surface is copper, and the amount of copper used increases, resulting in an increase in the weight of the pole 2.

[0077] In some embodiments, please refer to Figures 2 and 3 again. The clamping portion 3 also has at least one first positioning surface 33, which is located between the first clamping surface 31 and the first connecting surface 32. The first clamping surface 31 and the first connecting surface 32 are respectively connected to the first positioning surface 33; the flange 222 also has at least one second positioning surface 225, which is located and connected between the second clamping surface 223 and the second connecting surface 224; wherein the first positioning surface 33 is flush with the second positioning surface 225 and corresponds one to one.

[0078] In the above embodiment, the first positioning surface 33 and the second positioning surface 225 are provided flush so that the first positioning surface 33 and the second positioning surface 225 form a plane, and the rotation of the pole 2 is constrained by the inner rubber cover connected to the plane, thereby preventing the pole 2 from rotating in the through hole 11.

[0079] In some embodiments, please refer to Figure 1 again. The first part 21 has a first surface 212 and a second surface 213 that are opposite to each other in the first direction X, the second surface 213 faces the electrode assembly, and the second surface 213 is connected to the second part 22; the first part 21 also has a third surface 214, the third surface 214 is located between the first surface 212 and the second surface 213 along the first direction X, the third surface 214 faces the electrode assembly, and the third surface 214 is connected to the flange 222; the first part 21 also has a first circumferential surface 215, the first circumferential surface 215 is located between the second surface 213 and the third surface 214, the second surface 213 and the third surface 214 are respectively connected to the first circumferential surface 215, and the first circumferential surface 215 is connected to the second part 22; wherein, a rounded corner is provided between the first circumferential surface 215 and the third surface 214.

[0080] In the above embodiment, rounded corners are provided to ensure that the first portion 21 and the second portion 22 can still be fitted after cold heading, thereby preventing the first portion 21 and the second portion 22 from separating and improving the yield rate of the cold heading process.

[0081] In some embodiments, the radius of the rounded corner is R, satisfying: 2mm≤R≤7mm.

[0082] In the above embodiment, the radius R of the fillet can be 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, Any value among 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5.0mm, 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, 6.0mm, 6.1mm, 6.2mm, 6.3mm, 6.4mm, 6.5mm, 6.6mm, 6.7mm, 6.8mm, 6.9mm, 7.0mm, or the range between any two values. When the radius R of the fillet is too large, the sealing ring cannot be compressed normally. During the cold forging process, when the radius R of the fillet is too small, the first part 21 and the second part 22 are easily separated during the cold forging process, and the pole 2 cannot withstand sufficient shear force.

[0083] The following examples illustrate the ultimate shear force that the pole 2 can withstand through experiments. The results of the ultimate shear force that can be withstand when R takes different values ​​are as follows:

[0084] Example 13 Example 14 Example 15 Example 16 R / mm 0.257 Shear force / N 420 89 195 1985

[0085] The test method is as follows: fix the pole 2, apply opposite and gradually increasing forces in the second direction Y to the first body part and the second body part respectively, and record the magnitude of the force when cracks occur in the clamping part 3 and the flange 222.

[0086] In the above embodiment 13, the value of R is 0 mm, which is less than the lower limit of the value range, that is, there is no fillet between the first peripheral surface and the third surface 214. When the shear force is small, the pole 2 is damaged and the top cover assembly fails.

[0087] In the above Examples 14 to 16, the values ​​of D are all within the range of 2 mm to 7 mm, and the shear force when the clamping portion 3 and the flange 222 are separated is significantly greater than that in Example 13.

[0088] When the radius R of the fillet is greater than 7 mm, the difficulty of processing the first pole increases and the cost increases significantly. Since the fillet radius is too large, the sealing ring cannot be compressed normally, affecting the sealing performance.

[0089] In some embodiments, please refer to Figure 1 again. The first portion 21 has a first surface 212 and a second surface 213 that are opposite to each other in the first direction X, the second surface 213 faces the electrode assembly, and the second surface 213 is connected to the second portion 22; the first portion 21 also has a fourth surface 216, the fourth surface 216 is located between the first surface 212 and the second surface 213 along the first direction X, and the fourth surface 216 faces away from the electrode assembly; the first portion 21 also has a second circumferential surface 217, the second circumferential surface 217 is located between the first surface 212 and the fourth surface 216, the first surface 212 and the fourth surface 216 are respectively connected to the second circumferential surface 217; the first portion 21 also has a third circumferential surface 218, the third circumferential surface 218 is located between the fourth surface 216 and the first clamping surface 31, and the fourth surface 216 and the first clamping surface 31 are respectively connected to the third circumferential surface 218.

[0090] In the above embodiment, by providing the third circumferential surface 218 and the fourth surface 216, the first part 21 is separated from the main body 1 along the first direction X away from the portion of the electrode assembly where the top cover is exposed, so as to avoid the bus being lifted up by the main body 1 when welding the bus on the first part 21, thereby avoiding a cold weld between the bus and the first part 21, and thereby improving the welding reliability of the bus.

[0091] In some embodiments, please refer to Figures 4 and 5 again, where Figure 4 is a structural schematic diagram of the top cover assembly of the secondary battery provided in an embodiment of the present application, and Figure 5 is a detailed view of the frame A in Figure 4. The body 1 has a groove 13 on the side away from the electrode assembly along the first direction X, and the groove 13 surrounds the through hole 11; the top cover assembly also includes a positioning structure 12, which is connected to the side of the body 1 away from the electrode assembly in the first direction X and surrounds the groove 13, and the positioning structure 12 and the body 1 define an installation space; a portion of the flange 222 is located in the installation space, and a portion of the clamping portion 3 is located in the installation space; the plastic part 4 includes an outer rubber package 41 and an inner rubber package 42, a portion of the outer rubber package 41 is located between the positioning structure 12 and the first body portion 211 and connects the positioning structure 12, the first body portion 211 and the clamping portion 3; the inner rubber package 42 is connected to the outer rubber package 41, and a portion of the inner rubber package 42 is located in the installation space 14 and between the clamping portion 3 and the positioning structure 12 and connects the clamping portion 3 and the positioning structure 12 respectively.

[0092] In the above embodiment, the inner rubber coating 42 and the flange 222 respectively clamp the clamping portion 3 from two directions, so that the clamping portion 3 and the first body portion 211 connected to the clamping portion 3 are constrained in the first direction X, preventing the first body portion 211 from moving in the first direction X, thereby preventing the first portion 21 from separating from the second portion 22, thereby ensuring the reliability of the pole 2. In addition, the inner rubber coating 42, which is arranged around the clamping portion 3 and the flange 222 and connected to the positioning structure 12, can also limit the position of the pole 2 in the second direction Y.

[0093] In some embodiments, the side of the main body 1 facing the electrode assembly in the first direction X has a groove 13, and the groove 13 surrounds the through hole 11; the top cover assembly also includes a positioning structure 12, the positioning structure 12 is connected to the side of the main body 1 facing the electrode assembly in the first direction X and surrounds the groove 13, and the positioning structure 12 and the main body 1 define an installation space; part of the flange 222 is located in the installation space, and part of the clamping portion 3 is located in the installation space.

[0094] In the above embodiment, the positioning structure 12 and the body 1 respectively clamp the second clamping surface 223 and the first clamping surface 31, so that the terminal 2 is constrained in the first direction X, preventing the terminal 2 from moving in the first direction X. In addition, the constraint of the first clamping surface 31 by the body 1 can also prevent the first portion 21 from separating from the second portion 22, thereby ensuring the reliability of the terminal 2. In addition, by arranging the positioning structure 12 on the side of the body 1 facing the electrode assembly, the height of the terminal 2 on the side of the body 1 away from the electrode assembly can be reduced, thereby facilitating the arrangement of the secondary battery within the battery pack.

[0095] Specifically, the top cover assembly also includes upper plastic, a sealing ring and lower plastic. Part of the upper plastic is located in the installation space, and at least one of the clamping portion 3 and the flange 222 is connected to the part of the upper plastic located in the installation space, and the part of the upper plastic located in the installation space is also connected to the main body 1; the sealing ring is located in the installation space, and at least one of the clamping portion 3 and the flange 222 is sealed and connected to the part of the sealing ring located in the installation space, and the sealing ring is also sealed and connected to the main body 1; at least part of the lower plastic is located in the installation space, and at least one of the clamping portion 3 and the flange 222 is connected to the part of the lower plastic located in the installation space, and the part of the lower plastic located in the installation space is also connected to the main body 1.

[0096] Accordingly, the present application also provides a battery pack including a secondary battery as described in any of the above embodiments. The battery pack includes the secondary battery as described in the above embodiments, so the battery module includes the functions of the battery described in the above embodiments, which will not be repeated here.

[0097] Accordingly, the present application further provides an electrical device including a battery pack as described in any of the above embodiments. The electrical device includes the battery pack described in the above embodiments, so the functions of the battery pack described in the above embodiments are not repeated here.

[0098] Of course, the electrical equipment referred to in this application may include but is not limited to backup power supplies, electrodes, electric vehicles, electric bicycles, electric motorcycles, large batteries, etc.

[0099] In summary, the secondary battery, battery pack, and electrical equipment provided in the present application provide the clamping portion 3 so that the pole 2 and the first portion 21 can be better constrained, thereby effectively improving the reliability of the pole 2 .

[0100] The above is a detailed introduction to a secondary battery, a battery pack and an electrical device provided in the embodiments of the present application. Specific examples are used in the present application to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A secondary battery, wherein: The secondary battery includes: a housing, wherein the housing has a receiving cavity; an electrode assembly, the electrode assembly being disposed in the accommodating cavity; A top cover assembly having a first direction (X), the top cover assembly comprising: A body (1), the body (1) being connected to the shell and covering the accommodating cavity, the body (1) having a through hole (11); the body (1) having a groove (13) on a side away from or close to the electrode assembly along the first direction (X), the groove (13) surrounding the through hole (11); a positioning structure (12), the positioning structure (12) being connected to a side of the body (1) away from or close to the electrode assembly along the first direction (X) and surrounding the groove (13), the positioning structure (12) and the body (1) defining an installation space (14); A pole (2), the pole (2) being passed through the through hole (11), the pole (2) comprising a first portion (21) and a second portion (22) arranged along the first direction (X) and passing through the through hole (11); the first portion (21) comprising a first body portion (211), the second portion (22) comprising a second body portion (221) and a flange (222) arranged around the second body portion (221), a portion of the flange (222) being located in the installation space (14); the first body portion (211) being connected to the second body portion (221); a clamping portion (3), a portion of the clamping portion (3) being located in the installation space (14), the clamping portion (3) being arranged around the first body portion (211) and connected to the flange (222); A plastic part (4), part of which is located in the installation space (14), and the plastic part (4) is located between the clamping portion (3) and the body (1) and respectively connects the clamping portion (3) and the body (1).

2. The secondary battery according to claim 1, wherein The clamping portion (3) has a first clamping surface (31) and a first connecting surface (32) that are opposite to each other in the first direction (X), and the first clamping surface (31) is a surface of the clamping portion (3) that is opposite to the electrode assembly; The flange (222) has a second clamping surface (223) and a second connecting surface (224), the second clamping surface (223) and the second connecting surface (224) are opposite to each other, and the second clamping surface (223) faces the electrode assembly; The first connecting surface (32) and the second connecting surface (224) are connected.

3. The secondary battery according to claim 2, wherein The top cover assembly also has a second direction (Y), and the pole (2) has a maximum dimension D in the second direction (Y), satisfying: 20 mm ≤ D ≤ 30 mm; wherein the first direction (X) and the second direction (Y) intersect.

4. The secondary battery according to claim 1, wherein The clamping portion (3) has a maximum dimension H1 in the first direction (X), satisfying: 0 mm < H1 ≤ 1.0 mm.

5. The secondary battery according to claim 1, wherein The first portion (21) has a maximum size H2 in the first direction (X), and the pole (2) has a maximum size H3 in the first direction (X), satisfying: 0.6≤H2 / H3≤0.

9.

6. The secondary battery according to claim 2, wherein The clamping portion (3) further comprises at least one first positioning surface (33), the first positioning surface (33) being located between the first clamping surface (31) and the first connecting surface (32), the first clamping surface (31) and the first connecting surface (32) being respectively connected to the first positioning surface (33); The flange (222) further has at least one second positioning surface (225), and the second positioning surface (225) is located between and connected to the second clamping surface (223) and the second connecting surface (224); The first positioning surface (33) and the second positioning surface (225) are flush and correspond one to one.

7. The secondary battery according to claim 1, wherein The first portion (21) has a first surface (212) and a second surface (213) that are opposite to each other in the first direction (X), the second surface (213) faces the electrode assembly, and the second surface (213) is connected to the second portion (22).

8. The secondary battery according to claim 7, wherein The first portion (21) further has a third surface (214), the third surface (214) being located between the first surface (212) and the second surface (213) along the first direction (X), the third surface (214) facing the electrode assembly, and the third surface (214) being connected to the flange (222).

9. The secondary battery according to claim 8, wherein The first portion (21) further has a first circumferential surface (215), the first circumferential surface (215) is located between the second surface (213) and the third surface (214), the second surface (213) and the third surface (214) are respectively connected to the first circumferential surface (215), and the first circumferential surface (215) is connected to the second portion (22).

10. The secondary battery according to claim 9, wherein A rounded corner is provided between the first circumferential surface (215) and the third surface (214).

11. The secondary battery according to claim 10, wherein The radius of the fillet is R, which satisfies: 2mm≤R≤7mm.

12. The secondary battery according to claim 2, wherein The first portion (21) has a first surface (212) and a second surface (213) facing away from each other in the first direction (X), the second surface (213) faces the electrode assembly, and the second surface (213) is connected to the second portion (22); The first portion (21) further has a fourth surface (216), the fourth surface (216) being located between the first surface (212) and the second surface (213) along the first direction (X), and the fourth surface (216) facing away from the electrode assembly; The first portion (21) further has a second circumferential surface (217), the second circumferential surface (217) is located between the first surface (212) and the fourth surface (216), and the first surface (212) and the fourth surface (216) are respectively connected to the second circumferential surface (217); The first portion (21) further has a third circumferential surface (218), the third circumferential surface (218) being located between the fourth surface (216) and the first clamping surface (31), and the fourth surface (216) and the first clamping surface (31) being respectively connected to the third circumferential surface (218).

13. The secondary battery according to claim 1, wherein The body (1) has a groove (13) on one side away from the electrode assembly along the first direction (X); the positioning structure (12) is connected to the side of the body (1) away from the electrode assembly along the first direction (X); the plastic part (4) includes an outer rubber (41) and an inner rubber (42), and a portion of the outer rubber (41) is located between the positioning structure (12) and the first body part (211) and connects the positioning structure (12), the first body part (211) and the clamping part (3); the inner rubber (42) is connected to the outer rubber (41), and a portion of the inner rubber (42) is located in the installation space (14), and is located between the clamping part (3) and the positioning structure (12) and respectively connects the clamping part (3) and the positioning structure (12).

14. A battery pack, wherein: The secondary battery according to any one of claims 1 to 13 is included.

15. An electrical device, wherein: Comprising the battery pack as claimed in claim 14.

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