Secondary battery, battery pack, and electric device

Abstract

The utility model discloses a secondary battery, a battery pack and a power utilization device, the secondary battery has a first direction, and comprises a shell, an electrode assembly and a top cover assembly; the shell is provided with a containing cavity, the electrode assembly is arranged in the containing cavity, and the top cover assembly is connected with the shell and covers and seals the containing cavity; the top cover assembly comprises a top cover sheet, a lower insulating part and a locking part; the top cover plate comprises a first body and a first connecting part, the first connecting part is connected to one side, facing the electrode assembly, of the first body, and the first connecting part is provided with a first through hole; the lower insulating part is arranged on the side, facing the electrode assembly, of the first body, the lower insulating part and the first connecting part are oppositely arranged in the first direction, and a fixing hole is formed in the side, facing the first connecting part, of the lower insulating part; the locking piece is arranged in the first through hole and the fixing hole in a penetrating mode. The first connecting part and the lower insulating part are locked and connected through the locking part, so that the top cover piece or the lower insulating part is effectively prevented from being warped due to local stress, and the connection reliability of the top cover piece and the lower insulating part is ensured.

Description

Technical Field

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

[0002] Single cells usually use a top cover assembly to seal the shell. The top cover assembly usually includes a top cover sheet and a lower insulating member, and the lower insulating member and the top cover sheet are fixed together by clamping. However, for large-sized batteries, the top cover assembly is relatively large, and there will be local warping in the middle due to uneven stress distribution. At this time, if only clamping is used, there will be a large gap between the top cover sheet and the lower insulating member, and the fixing reliability is poor. Utility Model Content

[0003] Purpose of the utility model: An embodiment of the present application provides a secondary battery, aiming to solve the problem of poor fixing reliability between the existing top cover plate and the lower insulating member; another purpose of the embodiment of the present application is to provide a battery pack; another purpose of the embodiment of the present application is to provide an electrical device.

[0004] Technical solution: A secondary battery according to an embodiment of the present application has a first direction, and the secondary battery includes:

[0005] A housing having a receiving cavity;

[0006] An electrode assembly, disposed in the accommodating cavity;

[0007] A top cover assembly is connected to the shell and covers the accommodating cavity; the top cover assembly includes:

[0008] A top cover sheet, comprising a first body and a first connecting portion, wherein the first connecting portion is connected to a side of the first body facing the electrode assembly, and the first connecting portion has a first through hole;

[0009] a lower insulating member, disposed on a side of the first body facing the electrode assembly, the lower insulating member and the first connecting portion being arranged opposite to each other along the first direction, and a fixing hole being provided on a side of the lower insulating member facing the first connecting portion;

[0010] A locking piece is inserted into the first through hole and the fixing hole.

[0011] In some embodiments, the top cover assembly further includes a second connecting portion, wherein the second connecting portion includes:

[0012] A connecting plate connected to the lower insulating member;

[0013] A fixing plate connected to a side of the connecting plate away from the lower insulating member, wherein one end of the fixing plate away from the connecting plate extends toward the top cover plate;

[0014] Among them, the fixing plate, the connecting plate and the lower insulating member are surrounded by a groove, and the first connecting portion is at least partially arranged in the groove; the fixing plate is arranged opposite to the lower insulating member along the first direction, and the fixing plate is provided with a second through hole; the locking member is passed through the second through hole, the first through hole and the fixing hole.

[0015] In some embodiments, there is also a second direction, which intersects with the first direction; along the second direction, the first connecting part is provided with a plurality of the first through holes arranged at intervals, the lower insulating part is provided with a plurality of the fixing holes arranged at intervals, and the fixing plate is provided with a plurality of the second through holes arranged at intervals; the top cover assembly also includes a plurality of the locking members, each of which is respectively passed through a corresponding one of the first through holes, one of the second through holes and one of the fixing holes.

[0016] In some embodiments, the first connecting portion is interference fit with the groove.

[0017] In some embodiments, the orthographic projection of the first body on the lower insulating member covers the locking member and the lower insulating member.

[0018] In some embodiments, a side of the first connection portion away from the first body is chamfered.

[0019] In some embodiments, the top cover sheet includes two first connection portions, which are arranged on two sides of the lower insulating member opposite to each other along the first direction and are connected to the lower insulating member through the locking member.

[0020] In some embodiments, along the second direction, a size of the first connection portion is a mm, a size of the first body is b mm, and the following condition is satisfied: 0.5≤a / b<1.

[0021] Accordingly, a battery pack according to an embodiment of the present application includes a secondary battery as described in any one of the aforementioned embodiments.

[0022] Accordingly, an electrical device according to an embodiment of the present application includes a secondary battery as described in any one of the aforementioned embodiments, or a battery pack as described in the aforementioned embodiments.

[0023] Beneficial effect: Compared with the prior art, a secondary battery in an embodiment of the present application has a first direction, and the secondary battery includes a shell, an electrode assembly and a top cover assembly; the shell has a receiving cavity, the electrode assembly is arranged in the receiving cavity, and the top cover assembly is connected to the shell and covers the receiving cavity; the top cover assembly includes: a top cover sheet, a lower insulating member and a locking member; the top cover sheet includes a first body and a first connecting portion, the first connecting portion is connected to the side of the first body facing the electrode assembly, and the first connecting portion has a first through hole; the lower insulating member is arranged on the side of the first body facing the electrode assembly, the lower insulating member and the first connecting portion are arranged oppositely along the first direction, and the side of the lower insulating member facing the first connecting portion is provided with a fixing hole; the locking member is inserted into the first through hole and the fixing hole. The top cover assembly of the present application locks the first connecting portion of the top cover sheet with the lower insulating member through the locking member, effectively avoiding the warping of the top cover sheet or the lower insulating member due to local stress, thereby ensuring the reliability of the connection between the top cover sheet and the lower insulating member, and further ensuring the insulation performance of the lower insulating member.

[0024] Compared with the prior art, a battery pack according to an embodiment of the present application includes a secondary battery as described in any one of the above embodiments. It is understandable that the battery pack has all the technical features and beneficial effects of the above batteries, which will not be described in detail here.

[0025] Compared with the prior art, an electric device in an embodiment of the present application includes a secondary battery as described in any one of the above embodiments, or a battery pack as described in the above embodiments. It can be understood that the electric device has all the technical features and beneficial effects of the above batteries or battery packs, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. 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.

[0027] Figure 1 is a schematic structural diagram of a secondary battery in an embodiment of the present application;

[0028] Figure 2 is an exploded view of a secondary battery according to an embodiment of the present application;

[0029] Figure 3 is an exploded view of a top cover assembly of an embodiment of the present application;

[0030] Figure 4 is a cross-sectional view of a top cover assembly according to an embodiment of the present application;

[0031] Figure 5 yes Figure 4A partial enlarged view of part A;

[0032] Figure 6 It is a side view of the top cover assembly of an embodiment of the present application.

[0033] Reference numerals:

[0034] 1. Shell; 11. Accommodating cavity; 2. Electrode assembly; 3. Top cover assembly; 31. Top cover sheet; 311. First body; 312. First connecting portion; 3121. First through hole; 3122. Chamfer; 32. Lower insulating member; 321. Fixing hole; 33. Locking member; 34. Second connecting portion; 341. Fixing plate; 3411. Second through hole; 342. Connecting plate; 35. Groove; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0035] 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.

[0036] 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 positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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. Thus, 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. In the description of this application, "vertical" means completely vertical at 90° or almost completely vertical, for example, an angle within the range of 80° to 100° is considered vertical. Similarly, "parallel" means completely parallel or almost completely parallel, for example, an angle within 10° of completely parallel is considered parallel.

[0037] The applicant noted that the top cover assembly of a conventional square shell battery corresponds to a rectangular parallelepiped shape. The top cover assembly usually includes a top cover sheet and a lower insulating member. The two are directly connected by snap-fitting. A pole mounting hole is provided in the middle, and a partial connection on the large surface of the top cover sheet and the lower insulating member is achieved by installing the pole. For small-sized secondary batteries, this connection method can achieve a better connection and fixation between the top cover sheet and the lower insulating member. However, when the battery size is large, the fixing reliability between the lower insulating member and the top cover sheet is relatively poor, and local warping is prone to occur, thereby reducing the insulation performance.

[0038] In view of this, an embodiment of the present application provides a secondary battery to solve the above problems.

[0039] Please refer to Figure 1-Figure 6 A secondary battery according to an embodiment of the present application has a first direction X, and the secondary battery includes a shell 1, an electrode assembly 2 and a top cover assembly 3; the shell 1 has a accommodating cavity 11, the electrode assembly 2 is arranged in the accommodating cavity 11, and the top cover assembly 3 is connected to the shell 1 and covers the accommodating cavity 11; the top cover assembly 3 includes: a top cover sheet 31, a lower insulating member 32 and a locking member 33; the top cover sheet 31 includes a first body 311 and a first connecting portion 312, the first connecting portion 312 is connected to a side of the first body 311 facing the electrode assembly 2, and the first connecting portion 312 has a first through hole 3121; the lower insulating member 32 is arranged on a side of the first body 311 facing the electrode assembly 2, the lower insulating member 32 and the first connecting portion 312 are arranged opposite to each other along the first direction X, and a fixing hole 321 is provided on a side of the lower insulating member 32 facing the first connecting portion 312; the locking member 33 is penetrated into the first through hole 3121 and the fixing hole 321.

[0040] The top cover assembly 3 of the embodiment of the present application locks the first connection portion 312 of the top cover sheet 31 with the lower insulating member 32 through the locking member 33, effectively avoiding the top cover sheet 31 or the lower insulating member 32 from warping due to local stress, thereby ensuring the reliability of the connection between the top cover sheet 31 and the lower insulating member 32, and further ensuring the insulation performance of the lower insulating member 32.

[0041] In the embodiment of the present application, the first body 311 of the top cover sheet 31 and the lower insulating member 32 are arranged opposite to each other along the height direction of the battery, and the first connecting portion 312 of the top cover sheet 31 is arranged opposite to the lower insulating member 32 along the first direction X, and is locked and connected by the locking member 33. At this time, even if the top cover sheet 31 or the lower insulating member 32 is partially warped, the first connecting portion 312 will not be separated from the lower insulating member 32, thereby ensuring the reliability of the connection between the top cover sheet 31 and the lower insulating member 32, and further ensuring the insulation performance of the top cover assembly 3.

[0042] like Figure 3-Figure 6As shown, in some embodiments, the top cover assembly 3 also includes a second connecting portion 34, the second connecting portion 34 includes a connecting plate 342 and a fixing plate 341, the connecting plate 342 is connected to the lower insulating member 32, the fixing plate 341 is connected to the side of the connecting plate 342 away from the lower insulating member 32, and the end of the fixing plate 341 away from the connecting plate 342 extends toward the top cover sheet 31; wherein, the fixing plate 341, the connecting plate 342 and the lower insulating member 32 are surrounded by a groove 35, and the first connecting portion 312 is at least partially arranged in the groove 35; the fixing plate 341 is arranged opposite to the lower insulating member 32 along the first direction X, and the fixing plate 341 is provided with a second through hole 3411; the locking member 33 is penetrated into the second through hole 3411, the first through hole 3121 and the fixing hole 321.

[0043] In the embodiment of the present application, by providing the second connection portion 34, further limiting and fixing of the first connection portion 312 can be achieved, thereby improving the accuracy of the connection and engagement positioning between the lower insulating member 32 and the top cover sheet 31 and the connection stability.

[0044] Specifically, this embodiment sets the second connection part 34 so that the second connection part 34 is connected with the lower insulating member 32 to form a groove 35, and sets at least part of the first connection part 312 in the groove 35, and uses the groove 35 to limit the position of the first connection part 312, so that the alignment and positioning of the top cover sheet 31 and the lower insulating member 32 are more accurate when connected. Furthermore, the present application sets the second through hole 3411 on the fixing plate 341, so that the locking member 33 can pass through the second through hole 3411 and the first through hole 3121 from the outside in sequence and be fixed in the fixing hole 321, thereby realizing the fixed connection of the first connection part 312, the second connection part 34 and the lower insulating member 32.

[0045] It should be noted that the second connection portion 34 is preferably made of the same material as the lower insulating member 32 , and the connection plate 342 is preferably integrally connected to the lower insulating member 32 , thereby ensuring the stability of the connection between the second connection portion 34 and the lower insulating member 32 .

[0046] like Figure 3 and Figure 6 As shown, in some embodiments, there is also a second direction Y, which intersects with the first direction X; along the second direction Y, the first connecting portion 312 is provided with a plurality of first through holes 3121 arranged at intervals, the lower insulating member 32 is provided with a plurality of fixing holes 321 arranged at intervals, and the fixing plate 341 is provided with a plurality of second through holes 3411 arranged at intervals, and each first through hole 3121 is respectively arranged opposite to a second through hole 3411 and a fixing hole 321; the top cover assembly 3 also includes a plurality of locking members 33, each locking member 33 respectively passes through a corresponding first through hole 3121, a second through hole 3411, and finally is partially passed through a fixing hole 321.

[0047] In the embodiment of the present application, by providing a combination of multiple groups of first through holes 3121, second through holes 3411 and fixing holes 321, multiple fixing points between the top cover sheet 31 and the lower insulating member 32 can be provided, thereby improving the fixing stability and further effectively avoiding local warping.

[0048] In some embodiments, the first connection portion 312 is interference fit with the groove 35 .

[0049] In this embodiment, the first connection part 312 and the groove 35 are interference fit, which can further improve the connection stability of the first connection part 312 when it is in the groove 35, and prevent the first connection part 312 from being separated from the groove 35. At this time, the first connection part 312 is clamped by the fixing plate 341 and the lower insulating member 32, which further reduces the degree of freedom of the first connection part 312 in the groove 35, making it easier to fix, and can also maintain the fixing stability of the first connection part 312 when there is no locking member 33. Therefore, the interference fit of the first connection part 312 and the groove 35 can further improve the stability of the connection between the top cover sheet 31 and the lower insulating member 32.

[0050] In some embodiments, the orthographic projection of the first body 311 on the lower insulating member 32 covers the locking member 33 and the lower insulating member 32 .

[0051] In the embodiment of the present application, the orthographic projection of the first body 311 on the lower insulating member 32 covers the locking member 33 and the lower insulating member 32, so that the first body 311 can completely cover the lower insulating member 32, the first connecting portion 312 and the locking member 33. At this time, a sealed connection between the first body 311 and the shell 1 can be achieved.

[0052] like Figure 5 As shown, in some embodiments, a chamfer 3122 is provided on one side of the first connection portion 312 away from the first body 311, so that the first connection portion 312 can be smoothly inserted into the groove 35 to achieve rapid assembly. Furthermore, the chamfer 3122 can be a rounded corner, which can make the transition smoother, thereby making it easier for the first connection portion 312 to be inserted into the groove 35 to achieve an interference fit.

[0053] like Figure 3 and Figure 4 As shown, in some embodiments, the top cover sheet 31 includes two first connection portions 312 , which are arranged on both sides of the lower insulating member 32 along the first direction X and connected to the lower insulating member 32 through the locking member 33 .

[0054] In the embodiment of the present application, two first connection portions 312 are provided, which can achieve fixed connection with the lower insulating member 32 from both sides of the lower insulating member 32 , and can further improve the fixing stability.

[0055] Furthermore, two first connection parts 312 opposite to each other along the second direction Y may be provided. In this case, the two first connection parts 312 can be connected to the lower insulating member 32 in the second direction Y, thereby preventing the lower insulating member 32 or the first body 311 from warping along the first direction X.

[0056] like Figure 6 As shown, in some embodiments, along the second direction Y, the size of the first connection portion 312 is a mm, and the size of the first body 311 is b mm, satisfying: 0.5≤a / b<1.

[0057] Since the size of the first connection part 312 is large, the corresponding contact range with the first body 311 is also larger. At this time, the first connection part 312 can play a role in reinforcing the edge of the first body 311, which is equivalent to a reinforcing rib, and can improve the strength of the first body 311, thereby reducing the probability of local warping of the first body 311. In addition, the longer the first connection part 312 is, the larger the range of its connection with the lower insulating member 32 is, and the connection and fixation with the lower insulating member 32 in a larger range can be achieved, thereby also reducing the degree of freedom of the edge of the lower insulating member 32, and then also preventing the local warping of the lower insulating member 32 after being connected to the top cover sheet 31. Therefore, within the allowable range, the larger the size of the first connection part 312, the better. Of course, since the first body 311 needs to be sealed and connected to the shell 1, the size of the first connection part 312 needs to be smaller than the size of the first body 311.

[0058] Therefore, the embodiment of the present application defines 0.5≤a / b<1, at which time the size of the first connection part 312 is not less than half the size of the first body 311, and the line connecting the center of the first connection part 312 and the center of the first body 311 is preferably arranged perpendicular to the large surface of the first body 311, that is, the first connection part 312 is arranged in the center, at which time it can be ensured that the first connection part 312 can at least strengthen the middle part of the edge extending along the second direction Y of the first body 311, and only the part less than one-quarter of the length along the second direction Y of the two ends of the first body 311 is not connected to the first connection part 312, and under the action of the reinforced tensile stress of the first connection part 312, the end of the first body 311 can be effectively prevented from warping. And it can ensure that there is a large fixed connection range between the middle part and the lower insulating member 32.

[0059] It should be noted that the range of a / b is: 0.5≤a / b<1, that is, the value can be any value among 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.65, 0.7, 0.75, 0.8, 0.9, 0.95, 0.99 or a range value between any two values.

[0060] It should also be noted that in the embodiments of the present application, the sizes of a and b can be directly measured by length measuring tools such as a ruler and a vernier caliper.

[0061] Accordingly, a battery pack according to an embodiment of the present application includes a secondary battery as described in any one of the aforementioned embodiments.

[0062] It is understandable that the battery pack has all the technical features and beneficial effects of the aforementioned batteries, which will not be described in detail here.

[0063] Accordingly, an electrical device according to an embodiment of the present application includes a secondary battery as in any one of the aforementioned embodiments, or a battery pack as in the aforementioned embodiments.

[0064] It is understandable that the electrical device has all the technical features and beneficial effects of the aforementioned battery or battery pack, which will not be repeated here.

[0065] It should be noted that the power-consuming device in the embodiment of the present application can be a backup power supply, an electrode, an electric car, an electric bicycle, an electric motorcycle, a large storage battery, etc. In the above embodiments, the description of each embodiment has its own emphasis. For the part not described in detail in one embodiment, please refer to the relevant description of other embodiments.

[0066] 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, 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 solution and its core idea 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 solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A secondary battery, characterized in that: Having a first direction (X), the secondary battery comprises: A housing (1) having a receiving chamber (11); An electrode assembly (2) is arranged in the accommodating cavity (11); A top cover assembly (3) is connected to the housing (1) and covers the accommodating cavity (11); the top cover assembly (3) comprises: A top cover sheet (31), comprising a first body (311) and a first connecting portion (312), wherein the first connecting portion (312) is connected to a side of the first body (311) facing the electrode assembly (2), and the first connecting portion (312) has a first through hole (3121); a lower insulating member (32) disposed on a side of the first body (311) facing the electrode assembly (2), the lower insulating member (32) and the first connecting portion (312) being arranged opposite to each other along the first direction (X), and a fixing hole (321) being provided on a side of the lower insulating member (32) facing the first connecting portion (312); A locking member (33), wherein the locking member (33) is inserted into the first through hole (3121) and the fixing hole (321).

2. The secondary battery according to claim 1, characterized in that: The top cover assembly (3) further comprises a second connecting portion (34), wherein the second connecting portion (34) comprises: A connecting plate (342) connected to the lower insulating member (32); A fixing plate (341) connected to a side of the connecting plate (342) away from the lower insulating member (32), wherein one end of the fixing plate (341) away from the connecting plate (342) extends toward the top cover plate (31); The fixing plate (341), the connecting plate (342) and the lower insulating member (32) are surrounded by a groove (35), and the first connecting portion (312) is at least partially arranged in the groove (35); the fixing plate (341) is arranged opposite to the lower insulating member (32) along the first direction (X), and the fixing plate (341) is provided with a second through hole (3411); the locking member (33) is passed through the second through hole (3411), the first through hole (3121) and the fixing hole (321).

3. The secondary battery according to claim 2, characterized in that: It also has a second direction (Y), which intersects with the first direction (X); along the second direction (Y), the first connecting portion (312) is provided with a plurality of the first through holes (3121) arranged at intervals, the lower insulating member (32) is provided with a plurality of the fixing holes (321) arranged at intervals, and the fixing plate (341) is provided with a plurality of the second through holes (3411) arranged at intervals; the top cover assembly (3) also includes a plurality of the locking members (33), each of the locking members (33) is respectively inserted into a corresponding one of the first through holes (3121), one of the second through holes (3411) and one of the fixing holes (321).

4. The secondary battery according to claim 2, characterized in that: The first connecting portion (312) is interference fit with the groove (35).

5. The secondary battery according to claim 1, characterized in that: The orthographic projection of the first body (311) on the lower insulating member (32) covers the locking member (33) and the lower insulating member (32).

6. The secondary battery according to claim 1, characterized in that: A chamfer (3122) is provided on a side of the first connecting portion (312) away from the first body (311).

7. The secondary battery according to claim 1, characterized in that: The top cover sheet (31) comprises two first connection parts (312), which are arranged opposite to each other on two sides of the lower insulating member (32) along the first direction (X) and are connected to the lower insulating member (32) via the locking member (33).

8. The secondary battery according to claim 3, characterized in that: Along the second direction (Y), the size of the first connecting portion (312) is a mm, and the size of the first body (311) is b mm, satisfying: 0.5≤a / b<1.

9. A battery pack, characterized in that: Comprising the secondary battery as claimed in any one of claims 1 to 8.

10. An electrical device, characterized in that: It comprises the secondary battery as claimed in any one of claims 1 to 8, or the battery pack as claimed in claim 9.

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