Secondary battery, battery pack and electric equipment

Abstract

The utility model discloses a secondary battery, a battery pack and electric equipment, and belongs to the technical field of batteries, the secondary battery comprises a shell, an electrode assembly and a top cover assembly, and the shell is provided with an accommodating cavity; the electrode assembly is arranged in the accommodating cavity; the top cover assembly comprises a body, a pole, a clamping part and a plastic part, the body is connected with the shell and covers the accommodating cavity, and the body is provided with a through hole; the pole penetrates through the through hole and comprises a first part and a second part which are arranged along a first direction; the first part comprises a first body part, and the second part comprises a second body part and a flange arranged around the second body part; the first body part is at least connected with the second body part; the clamping part is arranged around the first body part and is connected with the flange; a part of the plastic part is located in the installation space, and the plastic part is located between the clamping part and the body and connected with the clamping part and the body. By arranging the clamping part connected with the first part, the connecting area of the first part is increased, and the possibility that the first part is separated from the second part is reduced.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a secondary battery, a battery pack and an electrical device. Background Art

[0002] 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.

[0003] However, since the connection area between the first part and the second part is limited, there is a possibility that the connection between the first part and the second part will fail, thereby causing a technical problem that the first part falls off and the secondary battery fails. Utility Model Content

[0004] Purpose of the utility model: The present application provides a secondary battery for solving the technical problem of the first part of the composite pole falling off; another purpose of the present application is to provide a battery pack; another purpose of the present application is to provide an electrical device.

[0005] Technical solution: The present application provides a secondary battery, the secondary battery comprising:

[0006] A housing having a receiving cavity;

[0007] An electrode assembly, wherein the electrode assembly is disposed in the accommodating cavity;

[0008] A top cover assembly, the top cover assembly comprising:

[0009] A body, the body is connected to the shell and covers the accommodating cavity, and the body has a through hole;

[0010] The body has a groove on one side away from or close to the electrode assembly along the first direction, and the groove surrounds the through hole;

[0011] a positioning structure, the positioning structure being connected to a side of the body 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;

[0012] A pole, the pole is passed through the through hole, the pole has a first direction, the pole includes a first part and a second part arranged along the first direction and passed through the through hole; 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, and a part of the flange is located in the installation space; the first body part is connected to the second body part;

[0013] A clamping portion, part of which is located in the installation space, the clamping portion is arranged around the first body portion and connected to the flange;

[0014] A plastic part, part of which is located in the installation space, and the plastic part is located between the clamping part and the body and respectively connects the clamping part and the body.

[0015] In some embodiments, 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;

[0016] 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;

[0017] Wherein, the first connection surface and the second connection surface are connected.

[0018] In some embodiments, 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.

[0019] In some embodiments, the clamping portion has a maximum dimension H in the first direction. 1 , meet: 0mm<H 1 ≤1.5mm.

[0020] In some embodiments, the first portion has a maximum dimension H in the first direction. 2 , the pole has a maximum dimension H in the first direction 3 , satisfying: 0.6≤H 2 / H 3 ≤0.9.

[0021] In some embodiments, 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;

[0022] The flange also 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;

[0023] Wherein, the first positioning surface is flush with the second positioning surface and corresponds one to one.

[0024] In some embodiments, 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;

[0025] 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;

[0026] The first portion further comprises 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;

[0027] Wherein, a fillet is arranged between the first circumferential surface and the third surface.

[0028] In some embodiments, the radius of the rounded corner is R, satisfying: 2mm≤R≤7mm.

[0029] In some embodiments, 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;

[0030] The first portion further has a fourth surface, the fourth surface is located between the first surface and the second surface along the first direction, and the fourth surface faces away from the electrode assembly;

[0031] 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;

[0032] 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.

[0033] In some embodiments, 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 an outer rubber package and an inner rubber package, and the outer rubber package 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 package is connected to the outer rubber package, and the inner rubber package 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.

[0034] Correspondingly, the present application also provides a battery pack, comprising a secondary battery as described in any one of the above embodiments.

[0035] Correspondingly, the present application also provides an electrical device, comprising a battery pack as described in any one of the above embodiments.

[0036] Beneficial effects: Compared with the prior art, the present application provides a secondary battery, which includes a shell, an electrode assembly and a top cover assembly, wherein the shell has 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, and 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, and the plastic part is located between the clamping portion and the body and connects the clamping portion and the body respectively. By providing a clamping part connected to the first part, the present application 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 limited by parts other than the second part, thereby further preventing the first part from falling off.

[0037] In addition, the present application also provides a battery pack, which includes the secondary battery of any one of the above embodiments. Since the connection between the first part and the second part of the secondary battery is more stable, the reliability of the battery pack is higher.

[0038] In addition, the present application also provides an electrical device, which includes the battery pack in the above embodiment. Since the reliability of the battery pack is higher, the reliability of the electrical device is also higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0040] Figure 1 A schematic diagram of the structure of a pole of a secondary battery provided in an embodiment of the present application;

[0041] Figure 2 for Figure 1 A top view of

[0042] Figure 3 for Figure 1 Bottom view of

[0043] Figure 4 A schematic diagram of the structure of a top cover assembly of a secondary battery provided in an embodiment of the present application;

[0044] Figure 5 for Figure 4 Detailed view of center frame A.

[0045] 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 package, 42-inner rubber package. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0047] In the description of the present 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 can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, 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 the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. 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.

[0048] 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 parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0049] The composite pole 2 includes a first portion 21 and a second portion 22 which are composited with each other. The first portion 21 and the second portion 22 are connected together by welding.

[0050] 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 technical problem of secondary battery failure.

[0051] In order to solve the technical problem of secondary battery failure caused by the falling off of the first part 21, the first embodiment of the present application provides a secondary battery, see Figure 1 , Figure 5 , Figure 1 A schematic diagram of the structure of a pole 2 of a secondary battery provided in an embodiment of the present application, wherein the secondary battery comprises a shell, an electrode assembly and a top cover assembly, wherein the shell has a receiving cavity; the electrode assembly is arranged in the receiving cavity; the top cover assembly comprises a body 1, a positioning structure 12, a pole 2, a clamping portion 3 and a plastic part 4, wherein the body 1 is connected to the shell and covers the receiving cavity, and 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, and the positioning structure 12 and the body 1 define an installation space 14; the pole 2 is passed through the through hole 11, and the pole 2 has There is a first direction X, which is the direction indicated by the X-axis in the figure. The pole 2 includes a first part 21 and a second part 22 arranged along the first direction X and penetrating the through hole 11; the first part 21 includes a first body part 211, and the second part 22 includes a second body part 221 and a flange 222 arranged around the second body part 221, and a part of the flange 222 is located in the installation space 14; the first body part 211 is connected to the second body part 221; a part of the clamping part 3 is located in the installation space 14, the clamping part 3 is arranged around the first body part 211, and is connected to the flange 222; a part of the plastic part 4 is located in the installation space 14, and the plastic part 4 is located between the clamping part 3 and the body 1 and connects the clamping part 3 and the body 1 respectively.

[0052] 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, so that the restraining and limiting ability of the second portion 22 on the first portion 21 is improved, 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 restrained and limited from outside the second portion 22, preventing the first portion 21 from moving in a direction 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.

[0053] 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.

[0054] In some embodiments, please refer again to Figure 1 The clamping portion 3 has a first clamping surface 31 and a first connecting surface 32 which are opposite to each other in the first direction X, and the first clamping surface 31 is the surface of the clamping portion 3 which is opposite to the electrode assembly; the flange 222 has a second clamping surface 223 and a second connecting surface 224, and 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.

[0055] In the above embodiment, the first connection surface 32 and the second connection surface 224 are provided to realize the surface connection between the clamping portion 3 and the flange 222. Since the clamping portion 3 is connected to the first portion 21, the connection between the first portion 21 and the second portion 22 through the clamping portion 3 is more firmly established. The first clamping surface 31 and the second clamping surface 223 are provided so that the pole 2 can be clamped and limited in the first direction X. In addition, the first portion 21 can be subjected to a force toward the second portion 22 through the first clamping surface 31 of the clamping portion 3, thereby preventing the first portion 21 from falling off in a direction away from the second portion 22, thereby improving the reliability of the pole 2.

[0056] The first connection surface 32 and the second connection surface 224 are completely fitted. In some embodiments of the present application, the first connection surface 32 and the second connection surface 224 are respectively planes; in other embodiments of the present application, the first connection surface 32 and the second connection surface 224 are respectively arc surfaces to increase the connection area between the clamping portion 3 and the flange 222.

[0057] Specifically, the distance between the first clamping surface 31 and the first surface 212 along the first direction X is greater than 0, so that when the clamping portion 3 is clamped, the first surface 212 can be 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, so as to facilitate the welding of the busbar. The second portion 22 has a fifth surface, which is away from the first surface 212 along the first direction X, and the distance between the second clamping surface 223 and the fifth surface along the first direction X is greater than 0, so that when the flange 222 is clamped, the second portion 22 can be exposed to the body 1 toward the electrode assembly along the first direction X, so as to facilitate the welding of the second portion 22 and the connecting piece.

[0058] In some embodiments, see Figure 2 and Figure 3 ,in, Figure 2 for Figure 1 A top view of Figure 3 for Figure 1 In the bottom view, the pole 2 has a second direction Y, the second direction Y is the direction indicated by the Y axis in the figure, the pole 2 has a maximum dimension D in the second direction Y, and satisfies: 20mm≤D≤30mm; wherein the first direction X and the second direction Y intersect.

[0059] In some embodiments, the first direction X and the second direction Y are perpendicular.

[0060] In the above embodiment, the maximum dimension D of the pole 2 in the second direction Y can be any one of 20.0mm, 20.5mm, 21.0mm, 21.5mm, 22.0mm, 22.5mm, 23.0mm, 23.5mm, 24.0mm, 24.5mm, 25.0mm, 25.5mm, 26.0mm, 26.5mm, 27.0mm, 27.5mm, 28.0mm, 28.5mm, 29.0mm, 29.5mm, and 30.0mm, 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 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 well 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 small, the clamping portion 3 and the flange 222 cannot be effectively clamped, and the pole 2 is easy to fall off from the body 1.

[0061] Some embodiments are given below. The top cover assembly is fixed, a thrust is applied to the pole 2 until the pole 2 is destroyed, and the thrust when the pole 2 is destroyed is recorded. The results when D takes different values ​​are as follows:

[0062]

[0063]

[0064] 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.

[0065] In the above embodiments 3 to 5, the values ​​of D are all within the range of 20 mm to 30 mm. When the push head applies a force of 1500 N to the pole 2, the pole 2 is not damaged and the top cover assembly works normally. At the same time, the closer the value of D is to the upper and lower limits of the range, the closer the thrust force borne by the pole 2 when it is damaged is to 1500 N.

[0066] 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 1500N required by the specification, the pole 2 is damaged and the top cover assembly fails.

[0067] In some embodiments, please refer again to Figure 1 The clamping portion 3 has a maximum dimension H in the first direction X. 1 , meet: 0mm<H 1 ≤1.0mm.

[0068] In the above embodiment, the clamping portion 3 has a maximum dimension H in the first direction X. 1 It can be any value among 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or a range between any two values. 1 When the value of is too large, the thickness of the flange 222 along the first direction X is too small, and the mechanical properties of the flange 222 are poor. 1 If the value of is too small, the thickness of the flange 222 along the first direction X is too large, and the flange 222 is a part of the second part 22, and the second part 22 is made of copper. The increase in the thickness of the flange 222 will cause the weight of the pole 2 to increase.

[0069] Some embodiments are given below. The top cover assembly is fixed to a tensile machine. A φ16 pusher is used to apply a thrust to the pole 2 until the pole 2 is destroyed. The thrust when the pole 2 is destroyed is recorded. H 1 When different values ​​are taken and the size of the first clamping surface 31 and the second clamping surface 223 in the first direction X is 1.5 mm, the results are as follows:

[0070]

[0071]

[0072] The above examples 8-9, H 1 The values ​​are all greater than the upper limit of the range. Although they can pass the test, due to H 1 When the value of is greater than 1.0 mm, the thrust when the pole 2 is damaged is very close to 1500 N. In order to make the pole 2 have a redundant value in actual use and have better reliability, H 1 Do not take a value greater than 1.0mm.

[0073] The above examples 10-11, H 1 The values ​​are all within the range of 0mm-1.0mm. When the push head applies a force of 1500N to the pole 2, the pole 2 is not damaged and the top cover assembly works normally. 1 The closer the value is to the upper limit of the range, the closer the thrust that pole 2 bears when it is destroyed is to 1500N.

[0074] Example 12 above, H 1 The value of is 0mm, which is less than the lower limit of the value range. Although it can pass the test, due to H 1 When the value of is 0mm, the clamping part does not exist, that is, H 1 When the value of is 0 mm, the technical problem of secondary battery failure caused by the falling off of the first part 21 cannot be solved, so H 1 Do not use 0mm.

[0075] In some embodiments, please refer again to Figure 1 The first portion 21 has a maximum dimension H in the first direction X. 2 , the pole 2 has a maximum dimension H in the first direction X 3 , satisfying: 0.6≤H 2 / H 3 ≤0.9.

[0076] In the above embodiment, H 2 / H 3 When the value of H is too large, the thickness of the second portion 22 is too small, and the welding performance of the second portion 22 when welding with the tab cannot be guaranteed. 3 = 6mm, if H 2 / H 3 >0.9,H 2 =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 welding with the pole ear; H 2 / H 3 When the value 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 again to Figure 2 and Figure 3The 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, and 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 arranged flush so that the first positioning surface 33 and the second positioning surface 225 form a plane, and then the rotation of the pole 2 is restricted by the inner rubber package connected to the plane to prevent the pole 2 from rotating in the through hole 11.

[0079] In some embodiments, please refer again to Figure 1 The first part 21 has a first surface 212 and a second surface 213 which 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 fillet is arranged 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 fit together 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 one of the following values ​​or the range between any two values ​​is selected from the group consisting of 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, and 7.0mm. When the radius R of the fillet is too large, the sealing ring cannot be compressed normally. During the cold heading 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 heading process, and the pole 2 cannot withstand sufficient shear force.

[0083] Some embodiments are given below to determine 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]

[0085] The test method is: 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 again to Figure 1The first part 21 has a first surface 212 and a second surface 213 which 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 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 part 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 part 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, the third circumferential surface 218 and the fourth surface 216 are provided so that the portion of the first part 21 that is exposed from the top cover away from the electrode assembly along the first direction X is separated from the main body 1, thereby preventing the bus from being lifted up by the main body 1 when welding the bus on the first part 21, thereby avoiding cold welding between the bus and the first part 21, and further improving the welding reliability of the bus.

[0091] In some embodiments, please refer to Figure 4 and Figure 5 ,in, Figure 4 A schematic diagram of the structure of a top cover assembly of a secondary battery provided in an embodiment of the present application, Figure 5 for Figure 4 Detailed view of the middle frame A, the body 1 has a groove 13 on one 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, the positioning structure 12 is connected to the side of the body 1 in the first direction X away from the electrode assembly and surrounds the groove 13, the positioning structure 12 and the 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; the plastic part 4 includes an outer rubber package 41 and an inner rubber package 42, part 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 part 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 package 42 and the flange 222 clamp the clamping part 3 from two directions respectively through the positive riveting structure, so that the clamping part 3 and the first body part 211 connected to the clamping part 3 are constrained in the first direction X, and the first body part 211 is prevented from moving in the first direction X, thereby preventing the first part 21 from being separated from the second part 22, thereby ensuring the reliability of the pole 2. In addition, the inner rubber package 42, which is arranged around the clamping part 3 and the flange 222 and connected to the positioning structure 12, can also limit the pole 2 in the second direction Y.

[0093] In some embodiments, a side of the main body 1 in the first direction X facing the electrode assembly 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 in the first direction X facing the electrode assembly and surrounds the groove 13, and the positioning structure 12 and the main 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.

[0094] In the above embodiment, the positioning structure 12 and the body 1 clamp the second clamping surface 223 and the first clamping surface 31 respectively through the reverse rivet structure, so that the pole 2 is constrained in the first direction X to prevent the pole 2 from moving in the first direction X. In addition, the constraint of the body 1 on the first clamping surface 31 can also prevent the first part 21 from being separated from the second part 22, thereby ensuring the reliability of the pole 2. In addition, by arranging the positioning structure 12 on the side of the body 1 facing the electrode assembly, the height of the pole 2 on the side of the body 1 away from the electrode assembly can be reduced, so as to facilitate the arrangement of the secondary battery in the battery pack.

[0095] Specifically, the top cover assembly also includes an upper plastic, a sealing ring and a 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 one 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 also provides an electric device, including a battery pack as in any one of the above embodiments. The electric 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 by the present application provide a 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 replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A secondary battery, characterized in that: The secondary battery comprises: A housing having a receiving cavity; An electrode assembly, wherein the electrode assembly is 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 inserted into the through hole (11), the pole (2) comprising a first portion (21) and a second portion (22) which are arranged along the first direction (X) and inserted into 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) is 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 being connected to the flange (222); A plastic part (4), part of which is located in the installation space (14); the plastic part (4) is located between the clamping part (3) and the body (1) and respectively connects the clamping part (3) and the body (1).

2. The secondary battery according to claim 1, characterized in that: The clamping portion (3) comprises a first clamping surface (31) and a first connecting surface (32) which are opposite to each other in the first direction (X), and the first clamping surface (31) is a surface of the clamping portion (3) which 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.

3. The secondary battery according to claim 2, characterized in that: 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: 20mm≤D≤30mm; wherein the first direction (X) and the second direction (Y) intersect.

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

5. The secondary battery according to claim 1, characterized in that: 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.

6. The secondary battery according to claim 2, characterized in that: The clamping portion (3) further comprises at least one first positioning surface (33), wherein the first positioning surface (33) is located between the first clamping surface (31) and the first connecting surface (32), and 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), and the second positioning surface (225) is located between and connected to the second clamping surface (223) and the second connecting surface (224); Wherein, 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, characterized in that: The first part (21) has a first surface (212) and a second surface (213) which 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 portion (21) further comprises 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); The first portion (21) further comprises a first circumferential surface (215), the first circumferential surface (215) being located between the second surface (213) and the third surface (214), the second surface (213) and the third surface (214) being connected to the first circumferential surface (215) respectively, and the first circumferential surface (215) being connected to the second portion (22); Wherein, a rounded corner is arranged between the first circumferential surface (215) and the third surface (214).

8. The secondary battery according to claim 7, characterized in that: The radius of the fillet is R, satisfying: 2mm≤R≤7mm.

9. The secondary battery according to claim 2, characterized in that: The first part (21) has a first surface (212) and a second surface (213) which 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 portion (21) further comprises a fourth surface (216), wherein 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) further comprises a second circumferential surface (217), the second circumferential surface (217) being located between the first surface (212) and the fourth surface (216), and the first surface (212) and the fourth surface (216) being respectively connected to the second circumferential surface (217); The first portion (21) further comprises a third circumferential surface (218), wherein 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).

10. The secondary battery according to claim 1, characterized in that: 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) comprises an outer rubber coating (41) and an inner rubber coating (42); a portion of the outer rubber coating (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 coating (42) is connected to the outer rubber coating (41); a portion of the inner rubber coating (42) is located in the installation space (14) and between the clamping part (3) and the positioning structure (12) and respectively connects the clamping part (3) and the positioning structure (12).

11. A battery pack, characterized in that: The invention comprises the secondary battery according to any one of claims 1 to 10.

12. An electrical device, characterized in that: Comprising the battery pack as claimed in claim 11.

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