Secondary battery and battery pack

Abstract

The utility model discloses a secondary battery and a battery pack, and belongs to the technical field of batteries, the secondary battery comprises a shell, an electrode assembly and a cover plate assembly, the cover plate assembly comprises a plate body, a pole, a connecting sheet and a sealing member, the plate body has a first direction and a second direction, and the plate body is connected with the shell; the pole penetrates through the plate body, the connecting piece is arranged in the containing cavity and connected with the pole, and a part of the sealing piece is arranged between the connecting piece and the plate body in the first direction and connected with the plate body and the connecting piece; wherein the connecting piece comprises a first part, a bent part and a second part, the first part is connected with the sealing element, one end of the bent part is connected with one side of the first part along the second direction, the second part is connected with one end of the bent part far away from the first part, and the tab is connected to one side of the second part facing the plate body along the first direction; when the bending part is bent, the second part extends along the first direction. The first part of the connecting piece is connected with the plate body to replace a welding block, so that the space utilization rate of the accommodating cavity is increased.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a secondary battery and a battery pack. BACKGROUND

[0002] The pole column and the welding block of the secondary battery are connected to clamp the plate body between the part of the pole column and the welding block, so that the plate body limits the pole column in the extension direction of the pole column hole, and the displacement of the pole column is avoided. Moreover, the welding block is used for connecting the connecting sheet, and the pole lug is drawn out from the body and connected to the connecting sheet after being bent.

[0003] However, the welding block and the pole lug connected to the connecting sheet occupy a certain space, so that the space utilization rate in the secondary battery is low. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims at providing a secondary battery to solve the technical problem of low space utilization rate in the secondary battery, and another object of the application is to provide a battery pack.

[0005] Technical scheme, the application provides a kind of secondary battery, comprising:

[0006] Shell, the shell has accommodating cavity;

[0007] Electrode assembly, the electrode assembly is set to the accommodating cavity, and the electrode assembly includes body and pole lug connected with the body;

[0008] Cover plate assembly, the cover plate assembly includes plate body, pole column, connecting sheet and sealing element, the plate body has first direction and second direction, and the plate body is connected with the shell and covers and seals the accommodating cavity;The pole column is arranged in the plate body, and the connecting sheet is arranged in the accommodating cavity, and the connecting sheet is connected with the pole column, and part of the sealing element is arranged between the connecting sheet and the plate body along the first direction and is connected with the plate body and the connecting sheet respectively;

[0009] Wherein, the connecting sheet includes first part, bending part and second part, the first part is connected with the sealing element, one end of the bending part is connected with the first part along one side of the second direction, the second part is connected with the end of the bending part away from the first part, and the pole lug is connected to one side of the second part along the first direction towards the plate body;When the bending part is bent, the second part extends along the first direction.

[0010] In some embodiments, the connecting sheet further includes a transition part, the transition part is connected to one side of the first part away from the plate body, and the bending part is connected between the transition part and the second part.

[0011] In some embodiments, the first portion has a maximum dimension T along the first direction, and 1.2mm≤T≤2.5mm is satisfied.

[0012] In some embodiments, the second portion has a maximum dimension t along the second direction when the bending portion is bent, and 0.2mm≤t≤1.8mm is satisfied.

[0013] In some embodiments, the pole post comprises a main body portion and a first limiting portion, the main body portion is arranged through the plate body, the first limiting portion is connected to the main body portion along the second direction, the first portion is sleeved with the main body portion, at least part of the first portion is arranged between the first limiting portion and the plate body, and is connected with the first limiting portion.

[0014] In some embodiments, the first portion has a mounting hole, the first limiting portion is arranged in the mounting hole, the first portion comprises a protrusion, the protrusion is arranged between the hole wall of the mounting hole and the first limiting portion, and is connected with the hole wall of the mounting hole and the first limiting portion respectively, and the protrusion forms a stepped structure.

[0015] In some embodiments, the pole post further comprises a second limiting portion, the second limiting portion is connected to the main body portion along the second direction, the first limiting portion and the second limiting portion are arranged at intervals along the first direction, and the plate body is arranged between the first portion and the second limiting portion; the cover plate assembly further comprises an insulating member, at least part of the insulating member is arranged between the second limiting portion and the plate body along the first direction, and is connected with the second limiting portion and the plate body respectively.

[0016] In some embodiments, the plate body has a pole post hole; the pole post further comprises a protruding portion, the protruding portion is connected to the main body portion along the second direction, the protruding portion is connected to one side of the second limiting portion close to the first limiting portion, and part of the protruding portion is arranged through the pole post hole; part of the sealing member is arranged between the protruding portion and the first portion along the first direction, and is connected with the protruding portion and the first portion respectively.

[0017] In some embodiments, the sealing member comprises:

[0018] a first sealing portion, the first sealing portion is arranged through the pole post hole, and the first sealing portion is arranged between the plate body and the protruding portion, and is connected with the plate body and the protruding portion respectively;

[0019] A second sealing part is connected to one side of the first sealing part along the first direction towards the first part, and a part of the second sealing part is arranged between the plate body and the first part along the first direction and connected to the plate body and the first part respectively; and a part of the second sealing part is arranged between the protruding part and the first part along the first direction and connected to the protruding part and the first part respectively.

[0020] Correspondingly, the application also provides a battery pack comprising the battery pack according to any one of the above embodiments.

[0021] Beneficial effects: compared with the prior art, the secondary battery provided by the embodiments of the application comprises a shell, an electrode assembly and a cover plate assembly, the shell has a containing cavity; the electrode assembly is arranged in the containing cavity, and the electrode assembly comprises a body and a tab connected to the body; the cover plate assembly comprises a plate body, a pole, a connecting piece and a sealing piece, the plate body has a first direction and a second direction, the plate body is connected to the shell and covers the containing cavity; the pole is arranged in the plate body, the connecting piece is arranged in the containing cavity, the connecting piece is connected to the pole, and a part of the sealing piece is arranged between the connecting piece and the plate body along the first direction and connected to the plate body and the connecting piece respectively; wherein the connecting piece comprises a first part, a bent part and a second part, the first part is connected to the sealing piece, one end of the bent part is connected to one side of the first part along the second direction, the second part is connected to the end of the bent part away from the first part, and the tab is connected to one side of the second part along the first direction towards the plate body; when the bent part is bent, the second part extends along the first direction. The first part of the connecting piece is connected to the plate body to replace the welding block, and meanwhile, the bent part is arranged to enable the second part to rotate relative to the first part, so that the tab can be connected between the second part and the plate body, thereby improving the space utilization of the containing cavity. BRIEF DESCRIPTION OF DRAWINGS

[0022] The technical solutions and other beneficial effects of the application will become apparent from the following detailed description of the application, taken in conjunction with the accompanying drawings.

[0023] Figure 1 A structure diagram of the secondary battery provided by the embodiments of the application;

[0024] Figure 2 A sectional view of the secondary battery provided by the embodiments of the application in one direction;

[0025] Figure 3 A structure diagram of the secondary battery provided by the embodiments of the application; Figure 2 A structure diagram of the secondary battery provided by the embodiments of the application;

[0026] Figure 4 A sectional view of the secondary battery provided by the embodiments of the application in another direction;

[0027] Figure 5 A structure diagram of the secondary battery provided by the embodiments of the application;Figure 4 Detail view at middle frame B;

[0028] Figure 6 An installation schematic view of the cover plate assembly and the electrode assembly provided by the embodiment of the present application;

[0029] Figure 7 A structure schematic view of the connecting piece provided by the embodiment of the present application;

[0030] Figure 8 A structure schematic view of the connecting piece when being bent provided by the embodiment of the present application;

[0031] 1000 - shell, 1100 - accommodating cavity, 2000 - electrode assembly, 2100 - body, 2200 - tab, 3000 - cover plate assembly, 3100 - plate body, 3110 - pole hole, 3200 - pole, 3210 - main body part, 3220 - first limiting part, 3230 - second limiting part, 3240 - protruding part, 3300 - connecting piece, 3310 - first part, 3311 - mounting hole, 3312 - first accommodating groove, 3313 - protrusion, 3320 - bent part, 3321 - through hole, 3330 - second part, 3340 - transition part, 3400 - sealing piece, 3410 - first sealing part, 3420 - second sealing part, 3500 - insulating piece. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0033] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms “connected” and “linked” should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected, or can communicate with each other; can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In the description of the present application, the meaning of “multiple” is two or more than two, unless otherwise explicitly specified and limited. In addition, the terms “first” and “second” are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include one or more features.

[0034] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplifying the present application, the components and arrangements of the specific examples are described. Of course, they are only examples and are not intended to limit the present application.

[0035] The pole column 3200 is connected with the welding block to clamp the plate body 3100 between the part of the pole column 3200 and the welding block, so as to realize the limiting of the plate body 3100 to the pole column 3200 in the extending direction of the pole column hole 3110, avoiding the displacement of the pole column 3200. Moreover, the welding block is used to connect the connecting sheet 3300, and the tab 2200 is led out from the body 2100 and connected to the connecting sheet 3300 after being bent.

[0036] However, the welding block and the tab 2200 connected to the connecting sheet 3300 occupy a certain space, so that the space utilization rate inside the secondary battery is low.

[0037] In order to solve the above technical problem of low space utilization rate inside the secondary battery, the first embodiment of the present application provides a secondary battery, please refer to Figure 1 、 Figure 2 and Figure 4 The secondary battery comprises a shell 1000, an electrode assembly 2000 and a cover plate assembly 3000, the shell 1000 has a containing cavity 1100; the electrode assembly 2000 is arranged in the containing cavity 1100, and the electrode assembly 2000 comprises a body 2100 and a tab 2200 connected with the body 2100; the cover plate assembly 3000 comprises a plate body 3100, a pole column 3200, a connecting sheet 3300 and a sealing piece 3400, the plate body 3100 has a first direction X and a second direction Y, the plate body 3100 is connected with the shell 1000 and covers and seals the containing cavity 1100; the pole column 3200 is arranged in the plate body 3100, the connecting sheet 3300 is arranged in the containing cavity 1100, the connecting sheet 3300 is connected with the pole column 3200, and part of the sealing piece 3400 is arranged between the connecting sheet 3300 and the plate body 3100 along the first direction X and connected with the plate body 3100 and the connecting sheet 3300 respectively;

[0038] The connecting sheet 3300 comprises a first part 3310, a bent part 3320 and a second part 3330, the first part 3310 is connected with the sealing piece 3400, one end of the bent part 3320 is connected with the first part 3310 along one side of the second direction Y, the second part 3330 is connected with the end of the bent part 3320 away from the first part 3310, and the tab 2200 is connected to one side of the second part 3330 along the first direction X and towards the plate body 3100; when the bent part 3320 is bent, the second part 3330 extends along the first direction X.

[0039] The first direction X is the direction of arrow X, and the second direction Y is the direction of arrow Y.

[0040] Specifically, when the bending portion 3320 is flattened, the second portion 3330 is arranged opposite to the plate body 3100 along the first direction X, and the first portion 3310 and the second portion 3330 are respectively located on both sides of the bending portion 3320 along the second direction Y. The tab 2200 is connected to one side of the second portion 3330 along the first direction X towards the plate body 3100.

[0041] In some embodiments, part of the pole 3200 is arranged on one side of the plate body 3100 away from the first portion 3310 along the first direction X. The plate body 3100 is clamped between the part of the pole 3200 and the first portion 3310 along the first direction X, that is, the first portion 3310 not only serves as a connection for the tab 2200, but also serves as a clamping for the plate body 3100, which can replace the welding block.

[0042] In some embodiments, the cover plate assembly 3000 further comprises an insulating piece 3500. At least part of the insulating piece 3500 is arranged between the plate body 3100 and the part of the pole 3200 along the first direction X, and insulatingly connects the part of the pole 3200 and the plate body 3100.

[0043] In some embodiments, the sealing piece 3400 is composed of insulating material, and the sealing piece 3400 can also serve as insulation between the first portion 3310 and the plate body 3100.

[0044] In some embodiments, referring to Figure 4 and Figure 6 , the first portion 3310 extends along the second direction YY, and the second portion 3330 has a connecting surface. During assembly of the secondary battery, the bending portion 3320 is bent so that the second portion 3330 can extend along the first direction X, and thus the connecting surface is perpendicular to the second direction Y. Since there is more operating space for connecting the second portion 3330 and the tab 2200 in the second direction Y, it is easier to connect the tab 2200 to the connecting surface along the second direction Y.

[0045] In the above embodiments, the connection piece 3300 capable of clamping the plate body 3100 with the pole 3200 is arranged to replace the function of the welding block, thereby reducing the types of parts of the cover plate assembly 3000, reducing the size of the cover plate assembly 3000 along the first direction X, and making the structure of the cover plate assembly 3000 more compact. At the same time, since the connection piece 3300 has the bending portion 3320 capable of bending, it also reduces the difficulty of connecting the tab 2200 between the second portion 3330 and the plate body 3100, and also reduces the space occupied by the tab 2200 in the first direction X in the accommodating cavity 1100, making the structure of the secondary battery more compact and the specific energy of the secondary battery better.

[0046] In some embodiments, referring to Figure 4 and Figure 5 The connecting piece 3300 further comprises a transition portion 3340 connected to the first portion 3310 away from the plate body 3100, and the bending portion 3320 is connected between the transition portion 3340 and the second portion 3330.

[0047] In the above embodiments, by arranging the transition portion 3340, the maximum dimension between the second portion 3330 and the first portion 3310 in the first direction X is increased, and the distance between the second portion 3330 and the plate body 3100 in the first direction X is increased, so as to provide more space for the tab 2200 after the bending portion 3320 is flattened. At the same time, arranging the transition portion 3340 can also avoid the first portion 3310 being warped or tilted when the bending portion 3320 is bent, thereby improving the reliability of the cover plate assembly 3000.

[0048] In some embodiments, referring to Figure 7 and Figure 8 The bending portion 3320 has a through hole 3321 penetrating through the bending portion 3320.

[0049] In some embodiments, the bending portion 3320 has a plurality of through holes 3321, and the plurality of through holes 3321 are arranged at intervals along a third direction, and the first direction X, the second direction Y and the third direction intersect.

[0050] In some embodiments, part of the plurality of through holes 3321 are oblong holes.

[0051] In the above embodiments, by arranging the through hole 3321, the bending portion 3320 is a weak portion, and when the second portion 3330 is turned, the bending portion 3320 is bent, avoiding the first portion 3310 or the second portion 3330 being bent when the second portion 3330 is turned over, thereby avoiding the first portion 3310 or the second portion 3330 being warped or tilted, and thereby improving the reliability of the connecting piece 3300.

[0052] In some embodiments, referring to Figure 5 In the first direction X, the first portion 3310 has a maximum dimension T, which satisfies: 1.2mm≤T≤2.5mm.

[0053] Specifically, the value of T can be 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm. When the value of T is larger, the mechanical property of the first part 3310 is better, the effect of the clamping plate body 3100 is better, and the pole piece 3200 is not easy to move relative to the plate body 3100 in the use process. When the value of T is smaller, the size of the first part 3310 in the first direction X is smaller, the volume of the first part 3310 occupying the accommodation cavity 1100 is smaller, and the space utilization rate inside the secondary battery is higher. When the value of T is within the range defined in the embodiments of the present application, the mechanical property of the first part 3310 is better, which can better position the pole piece 3200, and also can avoid occupying too much space by the first part 3310, so that the structure of the secondary battery is more compact, and the volume specific energy of the secondary battery is better.

[0054] In the above embodiments, by limiting the value of T, the mechanical property of the first part 3310 is better, the first part 3310 is not easy to deform when clamping the plate body 3100, the limiting effect of the first part 3310 on the pole piece 3200 is better, and at the same time, the first part 3310 will not occupy too much space in the first direction X, so that the structure of the secondary battery is more compact, and the volume specific energy of the secondary battery is better.

[0055] In some embodiments, please refer to Figure 5 , when the bending part 3320 is bent, the second part 3330 has a maximum size t in the second direction Y, which satisfies: 0.2 mm≤t≤1.8 mm.

[0056] Specifically, the value of t can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm. When the value of t is larger, the mechanical property of the second part 3330 is better, and the second part 3330 suspended at one end in the second direction Y is not easy to deform, and is not easy to cause short circuit by contacting other components. When the value of t is smaller, the volume of the second part 3330 occupying the accommodation cavity 1100 is smaller, and the space utilization rate inside the secondary battery is higher. When the value of T is within the range defined in the embodiments of the present application, the mechanical property of the second part 3330 is better, which can avoid deformation, thereby avoiding the connection piece 3300 and the tab 2200 from contacting other components and causing short circuit, and the reliability of the secondary battery is better, and at the same time, the structure of the secondary battery is more compact, and the volume specific energy of the secondary battery is better.

[0057] In some embodiments, please refer to Figure 2 ,Figure 3 、 Figure 4 and Figure 5 The pole 3200 includes a main body portion 3210 and a first limiting portion 3220. The main body portion 3210 is arranged through the plate body 3100. The first limiting portion 3220 is connected to the main body portion 3210 along the second direction Y. The first portion 3310 is sleeved with the main body portion 3210. At least part of the first portion 3310 is arranged between the first limiting portion 3220 and the plate body 3100, and is connected with the first limiting portion 3220.

[0058] In some embodiments, the first limiting portion 3220 is annularly arranged on the main body portion 3210.

[0059] In some embodiments, the first limiting portion 3220 is integrally formed with the main body portion 3210.

[0060] In some embodiments, the main body portion 3210 has a blind hole. The first limiting portion 3220 is outwardly folded from a portion of the main body portion 3210 surrounding the blind hole.

[0061] In the above-mentioned embodiments, the first limiting portion 3220 is arranged to limit the movement of the connecting piece 3300 along the first direction X, so as to avoid the movement of the connecting piece 3300 away from the plate body 3100 along the first direction X.

[0062] It can be understood that when connecting the pole 3200 and the connecting piece 3300, the first portion 3310 needs to be sleeved on the pole 3200 first, and then welding is performed. In the above-mentioned embodiments, the first limiting portion 3220 capable of performing certain positioning action on the connecting piece 3300 is arranged to reduce the difficulty of welding the pole 3200 and the connecting piece 3300, thereby reducing the assembly difficulty of the cover plate assembly 3000.

[0063] In some embodiments, referring to FIGS. 3 and Figure 5 The first portion 3310 has a mounting hole 3311. The first limiting portion 3220 is arranged in the mounting hole 3311. The first portion 3310 includes a protrusion 3313. The protrusion 3313 is arranged between the hole wall of the mounting hole 3311 and the first limiting portion 3220, and is connected with the hole wall of the mounting hole 3311 and the first limiting portion 3220 respectively. The protrusion 3313 forms a stepped structure.

[0064] Specifically, the stepped structure includes a face of the protrusion 3313 away from the cover plate assembly 3000 along the first direction X and a face of the protrusion 3313 toward the first limiting portion 3220 along a direction perpendicular to the first direction X.

[0065] Specifically, the first part 3310 has a first accommodating groove 3312 formed by a step structure of the protrusion 3313 and a hole wall of the mounting hole 3311 on a side of the cover plate assembly 3000 facing away from the first direction X, the first accommodating groove 3312 is arranged around the mounting hole 3311, and the first accommodating groove 3312 is in communication with the mounting hole 3311.

[0066] In some embodiments, the protrusion 3313 is arranged around the first limiting part 3220 in the circumferential direction of the first limiting part 3220.

[0067] In the above-mentioned embodiments, by arranging the first limiting part 3220 on the mounting hole 3311, the first limiting part 3220 is prevented from being exposed to the first part 3310, thereby occupying the space of the accommodation cavity 1100 in the secondary battery, and the space utilization inside the secondary battery is further improved. At the same time, it can be understood that when the first limiting part 3220 and the first part 3310 are welded, a weld reinforcement may be generated. In the above-mentioned embodiments, by arranging the protrusion 3313 to form the first accommodating groove 3312 to accommodate the weld reinforcement, the weld reinforcement is prevented from being exposed to the connecting piece 3300, thereby preventing the weld reinforcement from contacting other components to cause short circuit, and the reliability of the cover plate assembly 3000 and the secondary battery is improved.

[0068] In some embodiments, the plate body 3100 has a first surface and a second surface facing away from each other in the first direction X in the first direction X, the first limiting part 3220 has a limiting surface, the limiting surface is a tapered surface, and the included angle between the limiting surface and the first surface is an acute angle.

[0069] In some embodiments, referring to Figure 3 , the included angle α between the limiting surface and the first surface satisfies: 5°≤α≤75°.

[0070] In some embodiments, the mounting hole 3311 has a hole wall capable of abutting the limiting surface.

[0071] In the above-mentioned embodiments, by arranging the limiting surface and the hole wall capable of abutting the limiting surface, the connecting piece 3300 can be automatically centered after being sleeved on the pole 3200, and the difficulty of welding the pole 3200 and the connecting piece 3300 is further reduced, thereby reducing the assembly difficulty of the cover plate assembly 3000.

[0072] Specifically, the value of a can be 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°. When the value of a is small, the difficulty of folding the first limiting portion 3220 through the main body portion 3210 is low, and the connection difficulty of the connecting sheet 3300 and the pole 3200 is low. When the value of a is small, the supporting effect of the first limiting portion 3220 on the first portion 3310 is better, and the effect of the connecting sheet 3300 clamping the plate body 3100 is also better. When the value of a is within the range defined in the embodiments of the present application, the connecting sheet 3300 and the pole 3200 can be connected with low difficulty, and at the same time, the clamping effect of the connecting sheet 3300 on the plate body 3100 is good.

[0073] In some embodiments, referring to Figure 3 and Figure 5 The pole 3200 further comprises a second limiting portion 3230, the second limiting portion 3230 is connected to the main body portion 3210 along the second direction Y, the first limiting portion 3220 and the second limiting portion 3230 are arranged at intervals along the first direction X, and the plate body 3100 is arranged between the first portion 3310 and the second limiting portion 3230; the cover plate assembly 3000 further comprises an insulating piece 3500, at least part of the insulating piece 3500 is arranged between the second limiting portion 3230 and the plate body 3100 along the first direction X, and respectively connected to the second limiting portion 3230 and the plate body 3100.

[0074] In some embodiments, the second limiting portion 3230 is arranged around the main body portion 3210.

[0075] In some embodiments, the insulating piece 3500 is arranged between the second limiting portion 3230 and the plate body 3100 along the first direction X. In other embodiments, part of the insulating piece 3500 is arranged between the second limiting portion 3230 and the plate body 3100 along the first direction X, and respectively connected to the second limiting portion 3230 and the plate body 3100 to insulate the second limiting portion 3230 and the plate body 3100; part of the insulating piece 3500 is arranged around the second limiting portion 3230 to avoid the pole 3200 contacting other components to cause short circuit.

[0076] In the above embodiments, the second limiting portion 3230 is arranged to enable the pole 3200 to clamp the plate body 3100 in the first direction X with the connecting sheet 3300, so that the connecting sheet 3300 can play the role of a welding block, and thus the structure of the cover plate assembly 3000 is more compact, and the space utilization rate inside the secondary battery using the cover plate assembly 3000 is higher.

[0077] In some embodiments, referring to Figure 3 and Figure 5, the plate body 3100 has a pole hole 3110; the pole 3200 further comprises a protruding part 3240 connected to the main body part 3210 along the second direction Y, the protruding part 3240 is connected to one side of the second limiting part 3230 close to the first limiting part 3220, and part of the protruding part 3240 penetrates the pole hole 3110; part of the sealing element 3400 is arranged between the protruding part 3240 and the first part 3310 along the first direction X and connected to the protruding part 3240 and the first part 3310 respectively.

[0078] In some embodiments, the protruding part 3240 is arranged around the main body part 3210.

[0079] In the above-mentioned embodiments, by arranging the protruding part 3240 to increase the size of the pole 3200 along the second direction Y, the degree of elastic deformation of part of the sealing element 3400 along the second direction Y is increased, and the sealing performance of the sealing element 3400 is improved. At the same time, part of the sealing element 3400 can be clamped between the protruding part 3240 and the first part 3310 along the first direction X, that is, the protruding part 3240 also cooperates with the sealing element 3400 to extend the sealing path of the sealing element 3400, thereby improving the sealing effect of the sealing element 3400, and further improving the reliability of the cover plate assembly 3000. At the same time, the sealing element 3400 can indirectly connect the protruding part 3240 and the first part 3310, and when the first part 3310 is sleeved on the pole 3200, the indirectly connected protruding part 3240 can avoid the inclination of the first part 3310, thereby playing a positioning role on the connecting sheet 3300, reducing the welding difficulty of the connecting sheet 3300 and the pole 3200, and thereby reducing the assembly difficulty of the cover plate assembly 3000.

[0080] In some embodiments, referring to Figure 3 and Figure 5 , the sealing element 3400 comprises a first sealing part 3410 and a second sealing part 3420, the first sealing part 3410 penetrates the pole hole 3110, and the first sealing part 3410 is arranged between the plate body 3100 and the protruding part 3240 and connected to the plate body 3100 and the protruding part 3240 respectively; the second sealing part 3420 is connected to one side of the first sealing part 3410 along the first direction X towards the first part 3310, part of the second sealing part 3420 is arranged between the plate body 3100 and the first part 3310 along the first direction X and connected to the plate body 3100 and the first part 3310 respectively; part of the second sealing part 3420 is arranged between the protruding part 3240 and the first part 3310 along the first direction X and connected to the protruding part 3240 and the first part 3310 respectively.

[0081] In some embodiments, the first sealing part 3410 is arranged around the protruding part 3240, and the second sealing part 3420 is arranged around the main body part 3210.

[0082] In the above embodiments, the first sealing portion 3410 is arranged to seal the connecting protrusion 3240 and the plate body 3100, and the second sealing portion 3420 is arranged to seal the plate body 3100 and the first portion 3310, so as to improve the sealing performance of the cover plate assembly 3000, thereby improving the reliability of the cover plate assembly 3000. Meanwhile, the second sealing portion 3420 is arranged to be partially located between the protrusion 3240 and the first portion 3310, so as to indirectly connect the protrusion 3240 and the connecting sheet 3300, thereby avoiding the connecting sheet 3300 from being inclined when being sleeved on the pole 3200, and playing a certain positioning role.

[0083] Correspondingly, the application further provides a battery pack comprising the battery pack according to any one of the above embodiments.

[0084] The above describes in detail a secondary battery and a battery pack provided by the embodiments of the application. The principles and implementation manners of the application are described by using specific examples. The above descriptions of the embodiments are only used to help understand the technical solutions of the application and the core ideas thereof. Those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some technical features thereof can be replaced by 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 application.

Claims

1. A secondary battery characterized by comprising: The application relates to a battery cover plate assembly. The battery cover plate assembly comprises a housing, an electrode assembly arranged in the housing, and a cover plate assembly. The cover plate assembly comprises a plate body, a post, a connecting piece, and a sealing member. The plate body has a first direction and a second direction. The plate body is connected to the housing and covers the housing.

2. The secondary battery according to claim 1, characterized by The post is arranged in the plate body.

3. The secondary battery according to claim 1, characterized by The connecting piece is arranged in the housing and connected to the post.

4. The secondary battery according to claim 1, characterized by The sealing member is arranged between the connecting piece and the plate body along the first direction.

5. The secondary battery according to claim 1, characterized by The connecting piece comprises a first part, a bending part, and a second part.

6. The secondary battery according to claim 5, characterized by The first part is connected to the sealing member.

7. The secondary battery according to claim 5, characterized by One end of the bending part is connected to the first part along one side of the second direction.

8. The secondary battery according to claim 7, characterized by The second part is connected to the other end of the bending part.

9. The secondary battery according to claim 8, characterized by The post is connected to one side of the second part along the first direction. The bending part can be deformed to make the second part rotate away from the plate body. The connecting piece further comprises a transition part. The transition part is connected to one side of the first part away from the plate body. The bending part is connected between the transition part and the second part. The first part has a maximum dimension T along the first direction. 1.2mm<=T<=2.5mm. The second part has a maximum dimension t along the first direction. 0.2mm<=t<=1.8mm. The post comprises a main body and a first limiting part. The main body is arranged in the plate body. The first limiting part is connected to the main body along the second direction. The first part is sleeved on the main body. At least part of the first part is arranged between the first limiting part and the plate body. The first part has a mounting hole. The first limiting part is arranged in the mounting hole. The first part comprises a protrusion. The protrusion is arranged between the hole wall of the mounting hole and the first limiting part. The protrusion forms a stepped structure. The post further comprises a second limiting part. The second limiting part is connected to the main body along the second direction. The first limiting part and the second limiting part are arranged apart along the first direction. The plate body is arranged between the first part and the second limiting part. The cover plate assembly further comprises an insulating member. At least part of the insulating member is arranged between the second limiting part and the plate body along the first direction. The plate body has a post hole. The post further comprises a protruding part. The protruding part is connected to the main body along the second direction. The protruding part is connected to one side of the second limiting part close to the first limiting part. Part of the protruding part is arranged in the post hole. The sealing member is arranged between the protruding part and the first part along the first direction. The sealing member comprises: A first sealing portion is provided between the plate body and the protruding portion and connects the plate body and the protruding portion, respectively, and is provided in the pole hole. A second sealing portion is connected to the first sealing portion on the side of the first portion in the first direction, and a part of the second sealing portion is provided between the plate body and the first portion in the first direction and connects the plate body and the first portion, respectively. A part of the second sealing portion is provided between the protruding portion and the first portion in the first direction and connects the protruding portion and the first portion, respectively.

10. A battery pack, characterized by, A secondary battery including any one of claims 1-9.

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