Secondary battery and battery pack

Abstract

Disclosed in the present application are a secondary battery and a battery pack. The secondary battery comprises a top cover assembly comprising a top cover plate, an electrode terminal and a first insulating member, wherein the top cover plate has a through hole; the electrode terminal is arranged through the through hole; the electrode terminal comprises a first body and a flange, the flange being circumferentially connected to the peripheral side of the first body; the first insulating member is arranged around the electrode terminal and is connected between the top cover plate and the electrode terminal; and the first insulating member comprises annular first, second and third sections, the first section being connected to the second section, and the end of the second section away from the first section being connected to the third section, the first section, the second section, and the third section being integrally formed and enclosing a groove, and at least part of the flange being arranged in the groove. In the present application, the first section, the second section and the third section, which are integrally connected, enclose the groove, and the flange is arranged in the groove, so that the first insulating member is interposed between the electrode terminal and the top cover plate, thereby ensuring the insulation reliability of the first insulating member.

Description

Secondary batteries and battery packs

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 31, 2024, with application number 202420254956.3 and application name “Secondary Batteries and Battery Packs”, the entire contents of which are incorporated herein by reference. Technical Field

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

[0003] Secondary batteries, the primary energy storage unit of power batteries, use a top cover assembly to encapsulate the electrode assembly within the housing. Charging and discharging are performed using the poles on the top cover assembly. The poles are fixed to the top cover sheet, and the two are insulated by an insulator. However, the insulators are often split, resulting in unstable connections and the risk of insulation failure during battery use. SUMMARY OF THE INVENTION

[0004] The embodiments of the present application provide a secondary battery, aiming to solve the problem that a split insulating member is prone to the risk of insulation failure.

[0005] 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.

[0006] In a first aspect, a secondary battery according to an embodiment of the present application includes a top cover assembly, wherein the top cover assembly includes:

[0007] a top cover sheet having a through hole;

[0008] an electrode terminal, passing through the through hole; the electrode terminal comprises a first body and a flange, the flange being connected to the outer circumference of the first body;

[0009] A first insulating member is arranged around the electrode terminal and connected between the top cover plate and the electrode terminal; the first insulating member includes a first segment, a second segment and a third segment in an annular shape, the first segment is connected to the second segment, and the second segment is connected to the third segment at one end away from the first segment, the first segment, the second segment and the third segment are integrally formed and surrounded by a groove, and at least a portion of the flange is arranged in the groove.

[0010] Optionally, the flange has a first surface and a second surface opposite to each other, and an outer peripheral surface intersecting the first surface and the second surface, the first section is in contact with the first surface, the second section is in contact with the outer peripheral surface, and the third section is in contact with the second surface.

[0011] Optionally, the flange includes a first limiting portion, and the first limiting portion is arranged on the outer peripheral surface.

[0012] Optionally, the first insulating member includes a second limiting portion, which is arranged on a side of the second section facing the flange, and the first limiting portion cooperates with the second limiting portion to limit the relative rotation of the electrode terminal and the first insulating member.

[0013] Optionally, the top cover sheet includes:

[0014] a second body, the through hole passing through the second body;

[0015] A support platform is arranged around the inner wall of the through hole and extends toward the central axis of the through hole;

[0016] a connecting portion, arranged around the through hole and connected to the second body, wherein the connecting portion is arranged on a side of the through hole away from the support platform;

[0017] The third limiting portion is arranged around the inner circumference of the connecting portion and extends toward the central axis of the through hole; the first insulating member is arranged between the third limiting portion and the support platform, and the first section is in contact with the third limiting portion, and the third section is in contact with the support platform.

[0018] Optionally, the first insulating member includes a first protrusion connected to a side of the first section facing away from the flange.

[0019] Optionally, a first limiting groove is provided on a side of the third limiting portion facing the first section, and the first protrusion is arranged in the first limiting groove.

[0020] Optionally, the first insulating member further includes a second protrusion, the second protrusion is connected to a side of the second section facing away from the flange, and the first protrusion is connected to the second protrusion.

[0021] Optionally, a second limiting groove is provided on the side of the connecting portion facing the second section, the second limiting groove extends along the inner wall of the through hole to the support platform, the second limiting groove is connected to the first limiting groove, and the second protrusion is arranged in the second limiting groove.

[0022] Optionally, the first protrusion and the second protrusion are connected to form a fourth limiting portion, there are at least two fourth limiting portions, and the central angle between two adjacent fourth limiting portions is α°, satisfying: 110≤α≤180.

[0023] Optionally, a dimension of the first protrusion extending into the first limiting groove is a mm, satisfying: 0.1≤a≤0.5.

[0024] Optionally, the top cover assembly further includes a sealing member, which is disposed around the first body and is at least partially located between the first body and the support platform.

[0025] Optionally, the top cover assembly also includes a second insulating member, a portion of which is covered on the outer peripheral side of the connecting portion and the third limiting portion and is arranged around the first body; a portion of the second insulating member is spaced between the third limiting portion and the first section and the first body.

[0026] In a second aspect, a battery pack according to an embodiment of the present application includes a secondary battery as described in any one of the aforementioned embodiments. Beneficial effects

[0027] A secondary battery according to an embodiment of the present application includes a top cover assembly, the top cover assembly including a top cover sheet, an electrode terminal, and a first insulating member; the top cover sheet has a through hole; the electrode terminal is inserted into the through hole; the electrode terminal includes a first body and a flange, the flange being connected to the outer periphery of the first body; the first insulating member is arranged around the electrode terminal and connected between the top cover sheet and the electrode terminal; the first insulating member includes a first segment, a second segment, and a third segment in an annular shape, the first segment being connected to the second segment, the second segment being connected to the third segment at one end away from the first segment, the first segment, the second segment, and the third segment being integrally formed and surrounded by a groove, at least a portion of the flange being disposed within the groove. The present application achieves this by providing an integrally connected first segment, second segment, and third segment to form a groove, and placing the flange of the electrode terminal within the groove, so that the flange of the electrode terminal is wrapped on three sides by the first insulating member. This allows the first insulating member to be spaced between the electrode terminal and the top cover sheet from three directions, achieving a better insulation effect and ensuring the insulation reliability of the first insulating member.

[0028] A battery pack according to an embodiment of the present application includes the secondary battery according to the aforementioned embodiment. It is understood that the battery pack according to the embodiment of the present application has all the technical features and technical effects of the aforementioned secondary battery, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] FIG1 is a schematic diagram of the overall structure of a secondary battery according to an embodiment of the present application;

[0031] FIG2 is an exploded view of a secondary battery according to an embodiment of the present application;

[0032] FIG3 is a schematic structural diagram of a top cover assembly according to an embodiment of the present application;

[0033] FIG4 is an exploded view of a top cover assembly according to an embodiment of the present application;

[0034] FIG5 is a cross-sectional view of a top cover assembly according to an embodiment of the present application;

[0035] FIG6 is a schematic diagram of the overall structure of the top cover sheet according to an embodiment of the present application;

[0036] FIG7 is a cross-sectional view of a top cover sheet according to an embodiment of the present application;

[0037] FIG8 is a schematic structural diagram of an electrode terminal connected to a first insulating member according to an embodiment of the present application;

[0038] FIG9 is a cross-sectional view of an electrode terminal connected to a first insulating member according to an embodiment of the present application;

[0039] FIG10 is a schematic diagram of the overall structure of the first insulating member according to an embodiment of the present application;

[0040] FIG11 is a schematic diagram of the overall structure of the first insulating member from another perspective according to an embodiment of the present application;

[0041] FIG12 is a top view of the first insulating member according to an embodiment of the present application;

[0042] FIG13 is a partial enlarged view of the top cover assembly of an embodiment of the present application;

[0043] FIG14 is a top view of an electrode terminal according to an embodiment of the present application;

[0044] FIG15 is a schematic structural diagram of a top cover assembly according to an embodiment of the present application;

[0045] FIG16 is an exploded view of a top cover assembly according to an embodiment of the present application;

[0046] FIG17 is a cross-sectional view of the top cover assembly according to an embodiment of the present application.

[0047] Figure markings: 100, top cover assembly; 1, top cover sheet; 11, through hole; 12, support platform; 13, connecting part; 14, third limiting part; 141, first limiting groove; 142, second limiting groove; 15, second body; 2, electrode terminal; 21, first body; 22, flange; 221, first surface; 222, second surface; 223, outer peripheral surface; 224, first limiting part; 3, first insulating member; 31, first section; 32, second section; 33, third section; 34, groove; 35, second limiting part; 36, first protrusion; 37, second protrusion; 38, fourth limiting part; 4, sealing member; 5, second insulating member; 200, outer shell; 210, accommodating cavity; 300, electrode assembly. 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 the present application, it should be understood that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. 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. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined. The applicant has noticed that in the field of power batteries, with the continuous development of battery application scenarios, working conditions have become more complex, and the insulation requirements for secondary battery structural parts are also gradually increasing, especially the top cover assembly 100. The electrode terminal 2 of the top cover assembly 100 is connected to the pole ear of the electrode assembly 300, which is the connection window between the inside and the outside of the secondary battery. At the same time, the outer shell 200 of the secondary battery and the top cover sheet 1 of the top cover assembly 100 are usually made of aluminum. Ensuring the insulation reliability between the electrode terminal 2 and the top cover sheet 1 is crucial to the safety of the entire secondary battery. In one optional method, the electrode terminal 2 is usually made of an insulating shell 200 on the upper and lower sides, which is assembled and wrapped to form an insulating part. The insulating part is spaced between the top cover sheet 1 and the electrode terminal 2 to achieve the insulation effect between the electrode terminal 2 and the top cover sheet 1. However, this split insulating part is prone to unstable connection during the use of the secondary battery, resulting in poor insulation effect or direct insulation failure.

[0050] Please refer to Figures 1, 2 and 9. An embodiment of the present application provides a secondary battery, including a shell, an electrode assembly 300 and a top cover assembly 100. The shell has a accommodating cavity 210. The electrode assembly 300 is disposed in the accommodating cavity 210. The top cover assembly 100 is connected to the shell and covers the accommodating cavity 210. The top cover assembly 100 includes a top cover sheet 1, an electrode terminal 2 and a first insulating member 3; the top cover sheet 1 has a through hole 11; the electrode terminal 2 is passed through the through hole 11; the electrode terminal 2 includes a first body 21 and a flange 22, and the flange 22 is connected to the outer peripheral side of the first body 21; the first insulating member 3 is arranged around the electrode terminal 2 and connected between the top cover sheet 1 and the electrode terminal 2; the first insulating member 3 includes a ring-shaped first section 31, a second section 32 and a third section 33, the first section 31 is connected to the second section 32, and the end of the second section 32 away from the first section 31 is connected to the third section 33, the first section 31, the second section 32 and the third section 33 are integrally formed and surrounded by a groove 34, that is, the first section 31 and the third section 33 are bent relative to the second section 32, and the bending direction is the same, so that the groove 34 is formed, and at least part of the flange 22 is arranged in the groove 34.

[0051] In the embodiment of the present application, the first section 31, the second section 32 and the third section 33 are integrally connected to form a groove 34, and the flange 22 of the electrode terminal 2 is placed in the groove 34, so that the flange 22 of the electrode terminal 2 is wrapped on three sides by the first insulating member 3. In this way, the first insulating member 3 is spaced between the electrode terminal 2 and the top cover sheet 1 from three directions, thereby achieving a better insulation effect and ensuring the insulation reliability of the first insulating member 3.

[0052] In some embodiments, the flange 22 has a first surface 221 and a second surface 222 opposite to each other, and an outer peripheral surface 223 intersecting the first surface 221 and the second surface 222 , the first section 31 is in contact with the first surface 221 , the second section 32 is in contact with the outer peripheral surface 223 , and the third section 33 is in contact with the second surface 222 .

[0053] In the embodiment of the present application, the first surface 221 and the second surface 222 are arranged relative to each other along the direction of the electrode assembly 300 toward the top cover assembly 100; the first surface 221 is in contact with the first section 31, and at this time the first section 31 is arranged on the side of the flange 22 away from the electrode assembly 300; the second section 32 is in contact with the outer peripheral surface 223, and at this time it is equivalent to the second section 32 being arranged around the flange 22; the third section 33 is in contact with the second surface 222, and at this time the third section 33 is arranged on the side of the flange 22 facing the electrode assembly 300; in this way, the first section 31, the second section 32 and the third section 33 wrap the flange 22 from three sides. In addition, the flange 22 is disposed around the periphery of the first body 21 and connected to the first body 21. In this case, the flange 22 has only four side surfaces, three of which are protected by the three sections of the first insulating member 3. The inner peripheral surface faces the first body 21 and is connected to the first body 21. Therefore, the flange 22 has only three side surfaces facing outward: the first surface 221, the second surface 222, and the outer peripheral surface 223. These three side surfaces are also covered by the first insulating member 3. Therefore, the first insulating member 3 can be completely separated from the flange 22 and the top cover sheet 1, thus preventing contact between the flange 22 and the top cover sheet 1. At the same time, the first section 31, the second section 32, and the third section 33 are connected in sequence as a whole. When the first insulating member 3 is separated from the electrode terminal 2 and the top cover sheet 1, the connection between the first section 31, the second section 32, and the third section 33 can be effectively prevented from loosening, thereby maintaining the insulation effectiveness of the first insulating member 3 between the electrode terminal 2 and the top cover sheet 1. At the same time, when the surfaces of the first insulating member 3 and the flange 22 are in contact with each other, the contact between the first insulating member 3 and the flange 22 can be improved, and the possibility of displacement of the first insulating member 3 can be reduced.

[0054] In some embodiments, the flange 22 includes a first limiting portion 224, which is arranged on the outer peripheral surface 223, and the first insulating member 3 includes a second limiting portion 35, which is arranged on the side of the second section 32 facing the flange 22. The first limiting portion 224 cooperates with the second limiting portion 35 to limit the relative rotation of the electrode terminal 2 and the first insulating member 3.

[0055] In the embodiment of the present application, a first limiting portion 224 and a second limiting portion 35 are provided to cooperate with each other so as to limit each other, thereby limiting the relative rotation between the electrode terminal 2 and the first insulating member 3, thereby effectively preventing the twisting movement of the electrode terminal 2 during use and ensuring the stability of the fixation of the electrode terminal 2.

[0056] Specifically, as shown in Figures 10, 11, and 14, the opposing sides of the first limiting portion 224 and the second limiting portion 35 can be flat surfaces. In this case, the first limiting portion 224 and the second limiting portion 35 are in flat contact and fit. When the electrode terminal 2 is subjected to a torsional force, the second limiting portion 35 and the first limiting portion 224 abut against each other, effectively preventing the electrode terminal 2 from rotating circumferentially within the first insulating member 3. Of course, the first limiting portion 224 can also be a groove 34 recessed toward the first body 21, and the second limiting portion 35 can be a protrusion protruding toward the flange 22, with the protrusion placed in the groove 34 to achieve positional stop.

[0057] In some embodiments, the top cover sheet 1 includes a second body 15, a support platform 12, a connecting portion 13 and a third limiting portion 14; the through hole 11 passes through the second body 15; the support platform 12 is arranged around the inner wall of the through hole 11 and extends to the central axis of the through hole 11; the connecting portion 13 is arranged around the through hole 11 and connected to the second body 15, and the connecting portion 13 is arranged on the side of the through hole 11 away from the support platform 12; the third limiting portion 14 is arranged around the inner peripheral side of the connecting portion 13 and extends to the central axis of the through hole 11; the first insulating member 3 is arranged between the third limiting portion 14 and the support platform 12, and the first section 31 is in contact with the third limiting portion 14, and the third section 33 is in contact with the support platform 12.

[0058] In this embodiment, the support platform 12, the inner wall of the through hole 11, the connecting portion 13 and the third limiting portion 14 are used to wrap the first insulating member 3, and at the same time, the top cover sheet 1 is limited on the three sides of the first insulating member 3, thereby improving the limiting effect of the top cover sheet 1 on the combination of the electrode terminal 2 and the first insulating member 3 and improving the fixing effect of the electrode terminal 2 on the top cover sheet 1.

[0059] Specifically, in the embodiment of the present application, the first insulating member 3 is disposed between the first limiting portion 224 and the support platform 12, while the flange 22 of the electrode terminal 2 is disposed between the first segment 31 and the third segment 33 of the first insulating member 3. Therefore, the flange 22 is also confined between the third limiting portion 14 and the support platform 12. The support platform 12 is in contact with the third segment 33, supporting the first insulating member 3 and the flange 22 within the through-hole 11, preventing the electrode terminal 2 and the first insulating member 3 from falling into the accommodating cavity 210. Simultaneously, the support platform 12 is in contact with the first insulating member 3 to seal the through-hole 11, thereby achieving a sealed top cover sheet 1. The connecting portion 13 protects the first insulating member 3 from the outer peripheral side of the second section 32. The third connecting portion 13 is arranged on the side of the first section 31 away from the support platform 12, and is used to limit the first insulating member 3 and the electrode terminal 2 in the direction of the electrode assembly 300 toward the top cover assembly 100, and is used to confine the electrode terminal 2 and the first insulating member 3 in the through hole 11 of the top cover sheet 1, so as to fix the electrode terminal 2 and the first insulating member 3.

[0060] It should be noted that the support platform 12, the inner wall of the through hole 11, the connecting portion 13 and the third limiting portion 14 cooperate with each other to limit and surround the first insulating member 3 for protection, providing an accommodation space for the first insulating member 3, thereby effectively preventing the first insulating member 3 from being squeezed or damaged during the use of the secondary battery, thereby ensuring that the first insulating member 3 continues to maintain a good insulating state.

[0061] In addition, it should be noted that the first section 31 is arranged between the third limiting portion 14 and the flange 22. Preferably, the first section 31 is respectively fitted with the first surface 221 of the flange 22 and the third limiting portion 14, the second section 32 is respectively fitted with the outer peripheral surface 223 of the flange 22 and the inner wall and connecting portion 13 of the through hole 11, and the third section 33 is respectively fitted with the second surface 222 of the flange 22 and the support platform 12, thereby realizing the limiting fixation of the first insulating part 3 and preventing the first insulating part 3 from shaking between the third limiting portion 14 and the support platform 12, which is more conducive to maintaining the stability of the structure of the first insulating part 3, and thus ensuring the insulation performance of the first insulating part 3.

[0062] As shown in Figures 6 to 8 and Figures 10-11, in some embodiments, the first insulating member 3 includes a first protrusion 36, which is connected to the side of the first section 31 facing away from the flange 22; the third limiting portion 14 is provided with a first limiting groove 141 on the side facing the first section 31, and the first protrusion 36 is arranged in the first limiting groove 141.

[0063] In the embodiment of the present application, the first protrusion 36 and the first limiting groove 141 cooperate with each other to prevent the first insulating member 3 from rotating circumferentially between the third limiting portion 14 and the support platform 12, thereby ensuring the fixing stability of the electrode terminal 2.

[0064] In some optional embodiments, as shown in Figures 6-8 and Figures 10-11, in some embodiments, the first insulating member 3 also includes a second protrusion 37, the second protrusion 37 is connected to the side of the second section 32 facing away from the flange 22, and the first protrusion 36 is connected to the second protrusion 37; the connecting portion 13 is provided with a second limiting groove 142 on the side facing the second section 32, the second limiting groove 142 extends along the inner wall of the through hole 11 to the support platform 12, the second limiting groove 142 is connected to the first limiting groove 141, and the second protrusion 37 is arranged in the second limiting groove 142.

[0065] In the embodiment of the present application, a second protrusion 37 is provided to connect with the first protrusion 36 to form an L-shaped fourth limiting portion 38, and a second limiting groove 142 is provided to connect with the first limiting groove 141 to form an L-shaped limiting groove. At this time, the coverage range of the limiting portion and the limiting groove is increased, thereby improving the limiting effect, providing greater anti-torsion force, and thus more effectively rotating the first insulating part 3, maintaining the stability of the first insulating part 3 fixed on the top cover plate 1.

[0066] It should be noted that the first protrusion 36 and the second protrusion 37 are connected as one piece, which is equivalent to adding an L-shaped reinforcement rib to the outer wall of the first insulating member 3, thereby improving the structural strength of the integrated first insulating member 3 and ensuring its structural stability is not destroyed, thereby ensuring its insulation effect.

[0067] As shown in FIG12 , in some embodiments, the first protrusion 36 and the second protrusion 37 are connected to form a fourth limiting portion 38 . There are at least two fourth limiting portions 38 , and the central angle between two adjacent fourth limiting portions 38 is α°, satisfying: 110≤α≤180.

[0068] In an embodiment of the present application, the fourth limiting portion 38 cooperates with the first limiting groove 141 and the second limiting groove 142 to stop rotation, wherein the number of the fourth limiting portions 38 is preferably 2 or more, wherein the angle range between the two fourth limiting portions 38 is from 110° to 180°. While achieving the goal of anti-torsion, the number of the fourth limiting portions 38 is as small as possible, preferably two, so as to facilitate the production, processing and manufacturing of the fourth limiting portion 38 and the first limiting groove 141 and the second limiting groove 142.

[0069] Of course, it should be noted that the angle between two adjacent fourth limiting portions 38 in the embodiment of the present application can also be any value among 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, or a range between any two values. The angle can also be directly measured using an angle measuring tool.

[0070] Some specific embodiments of this application are as follows:

[0071] Angle α between two adjacent fourth limiting portions 38 / degree Torque / N·m Whether the manufacturing mold interferes Example 190 11.4 Yes Example 2 110 11.5 No Example 3 120 11.7 No Example 4 150 11.3 No Example 5 180 11.5 No

[0072] It should be noted that in the embodiment of the present application, when the angle between two adjacent fourth limiting portions 38 is larger (the total angle range is from 0 to 180 degrees), it is convenient to process and manufacture when it is set in the range of 110° to 180°, and the force is also more uniform. An angle less than 110° will interfere with the manufacturing mold, and the mold cannot be used for batch manufacturing, which significantly increases the production cost.

[0073] As shown in FIG. 13 , in some embodiments, the dimension of the first protrusion 36 extending into the first limiting groove 141 is a mm, satisfying: 0.1≤a≤0.5.

[0074] In the embodiment of the present application, the size range of the first protrusion 36 extending into the first limiting groove 141 is set from 0.1 mm to 0.5 mm, which can ensure sufficient torque and ensure that the connecting portion 13 and the third limiting portion 14 of the top cover plate 1 are not too thin to affect the fixing strength of the electrode terminal 2.

[0075] Specifically, the dimension of the first protrusion 36 of the embodiment extending into the first limiting groove 141 can be any value among 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, or a range between any two values. This dimension can be directly measured using a length measuring tool such as a vernier caliper.

[0076] Some specific embodiments of this application are as follows:

[0077] Dimension of the first protrusion 36 extending into the first limiting groove 141 / mm Torque / N·m Thrust / N Example 1 0 6 2 2 10 Example 2 0.1 8.8 2 1 8 8 Example 3 0.3 1 0.5 2 0 4 6 Example 4 0.5 1 3.2 1 5 3 3 Example 5 0.6 1 5.3 1 1 2 4

[0078] As can be seen from the above embodiment, while the thickness of the third limiting portion 14 remains unchanged, the greater the extent to which the first protrusion 36 extends into the first limiting groove 141, the deeper the first limiting groove 141. Consequently, the greater the torque it can withstand, and the correspondingly smaller the thrust it can withstand. Therefore, to maintain reasonable thrust and torsional strength, the embodiment of the present application selects a dimension range of 0.1 ≤ a ≤ 0.5 for the extent to which the first protrusion 36 extends into the first limiting groove 141.

[0079] The torque test is performed by fixing the top cover at the bottom end of a torque machine and the electrode terminal 2 at the top end. The torque test is performed at a speed of 20° / min until failure, and the maximum torque is recorded. The thrust test is performed by fixing the top cover with a tensile machine. For a φ16 electrode terminal 2, a φ16 pusher is used to push the terminal until failure, and the maximum force is recorded.

[0080] In some embodiments, the top cover assembly 100 further includes a seal 4 , which is disposed around the first body 21 , and at least partially located between the first body 21 and the support platform 12 .

[0081] In the embodiment of the present application, a seal 4 is provided to seal the gap between the electrode terminal 2 and the top cover sheet 1 . The sealing effect of the Baocheng top cover assembly 100 prevents the electrolyte from overflowing from around the electrode terminal 2 .

[0082] It should be noted that at least a portion of the seal 4 is located between the first body 21 and the support platform 12. This prevents the first body 21 and the support platform 12 from short-circuiting and ensures insulation between the first body 21 and the support platform 12. The seal 4 can also be partially located between the flange 22 and the support platform 12. In this case, the seal 4 is used as a spacer between the flange 22 and the support platform 12 to prevent contact between the support platform 12 and the flange 22, thereby improving the insulation effect.

[0083] As shown in Figures 15-17, in some embodiments, the top cover assembly 100 also includes a second insulating member 5, and a portion of the second insulating member 5 is arranged on the outer peripheral side of the connecting portion 13 and the third limiting portion 14 and is arranged around the first body 21; a portion of the second insulating member 5 is arranged at intervals between the third limiting portion 14 and the first section 31 and the first body 21.

[0084] In the embodiment of the present application, the second insulating member 5 may or may not be provided outside the connecting portion 13 and the third limiting portion 14, because the first insulating member 3 already effectively insulates the electrode terminal 2 from the top cover sheet 1. When the second insulating member 5 is not provided, insulating material can be saved, reducing the overall cost of the battery.

[0085] In the embodiment of the present application, a second insulating member 5 can also be provided on the outside of the connecting portion 13 and the third limiting portion 14. At this time, the second insulating member 5 is not only wrapped around the outside of the connecting portion 13 and the third limiting portion 14, but part of the second insulating member 5 fills the gap between the first body 21 and the third connecting portion 13 and the second insulating member 5, thereby ensuring the insulation effect and the creepage distance, thereby ensuring the insulation effect between the electrode terminal 2 and the top cover sheet 1.

[0086] Accordingly, a battery pack according to an embodiment of the present application includes the secondary battery according to the aforementioned embodiment.

[0087] It can be understood that the battery pack of the embodiment of the present application has all the technical features and technical effects of the aforementioned secondary battery, which will not be described in detail here.

[0088] It should be noted that the battery pack of the embodiment itself can be used for backup power supply, electrodes, electric vehicles, electric bicycles, electric motorcycles, large batteries, etc.

[0089] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0090] The above is a detailed introduction to a secondary battery and a battery pack provided in the embodiments of the present application, and specific examples are used 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 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 invention comprises a top cover assembly, wherein the top cover assembly comprises: a top cover sheet having a through hole; an electrode terminal, passing through the through hole; the electrode terminal comprises a first body and a flange, the flange being connected to the outer circumference of the first body; A first insulating member is arranged around the electrode terminal and connected between the top cover plate and the electrode terminal; the first insulating member includes a first segment, a second segment and a third segment in an annular shape, the first segment is connected to the second segment, and the second segment is connected to the third segment at one end away from the first segment, the first segment, the second segment and the third segment are integrally formed and surrounded by a groove, and at least a portion of the flange is arranged in the groove.

2. The secondary battery according to claim 1, wherein The flange has a first surface and a second surface facing each other, and an outer peripheral surface intersecting the first surface and the second surface. The first section is in contact with the first surface, the second section is in contact with the outer peripheral surface, and the third section is in contact with the second surface.

3. The secondary battery according to claim 2, wherein The flange includes a first limiting portion, and the first limiting portion is arranged on the outer peripheral surface.

4. The secondary battery according to claim 3, wherein The first insulating member includes a second limiting portion, which is arranged on a side of the second section facing the flange. The first limiting portion cooperates with the second limiting portion to limit relative rotation between the electrode terminal and the first insulating member.

5. The secondary battery according to claim 2, wherein The top cover sheet comprises: a second body, the through hole passing through the second body; A support platform is arranged around the inner wall of the through hole and extends toward the central axis of the through hole; a connecting portion, arranged around the through hole and connected to the second body, wherein the connecting portion is arranged on a side of the through hole away from the support platform; The third limiting portion is arranged around the inner circumference of the connecting portion and extends toward the central axis of the through hole; the first insulating member is arranged between the third limiting portion and the support platform, and the first section is in contact with the third limiting portion, and the third section is in contact with the support platform.

6. The secondary battery according to claim 5, wherein The first insulating member includes a first protrusion connected to a side of the first segment facing away from the flange.

7. The secondary battery according to claim 6, wherein A first limiting groove is provided on a side of the third limiting portion facing the first section, and the first protrusion is disposed in the first limiting groove.

8. The secondary battery according to claim 7, wherein The first insulating member further includes a second protrusion connected to a side of the second section facing away from the flange, and the first protrusion is connected to the second protrusion.

9. The secondary battery according to claim 8, wherein A second limiting groove is provided on the side of the connecting portion facing the second section. The second limiting groove extends along the inner wall of the through hole to the support platform. The second limiting groove is connected to the first limiting groove. The second protrusion is provided in the second limiting groove.

10. The secondary battery according to claim 8, wherein The first protrusion and the second protrusion are connected to form a fourth limiting portion. There are at least two fourth limiting portions. The central angle between two adjacent fourth limiting portions is α°, satisfying the following: 110≤α≤180.

11. The secondary battery according to claim 7, wherein The dimension of the first protrusion extending into the first limiting groove is a mm, which satisfies the following: 0.1≤a≤0.

5.

12. The secondary battery according to claim 5, wherein The top cover assembly further includes a sealing member disposed around the first body, and the sealing member is at least partially located between the first body and the support platform.

13. The secondary battery according to claim 12, wherein The top cover assembly also includes a second insulating member, a portion of which is covered on the outer peripheral side of the connecting portion and the third limiting portion and is arranged around the first body; a portion of the second insulating member is spaced apart and arranged between the third limiting portion and the first section and the first body.

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

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