CN214505622U

CN214505622U - Battery cover cap assembly and lithium battery

Info

Publication number: CN214505622U
Application number: CN202120204395.2U
Authority: CN
Inventors: 田好鹏; 赵悠曼
Original assignee: Dongguan Chuangming Battery Technology Co Ltd
Current assignee: Dongguan Chuangming Battery Technology Co Ltd
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2021-10-26
Anticipated expiration: 2031-01-25

Abstract

The application discloses a battery cover cap assembly and a lithium battery, relates to the technical field of batteries, and aims to solve the problem that the fluctuation of the internal resistance value of the cover cap assembly is large when the lithium battery in the related technology is used. The battery cap component comprises a sealing sleeve, and a top cap, a thermistor chip and an explosion-proof chip which are sequentially arranged in the sealing sleeve along the axial direction of the sealing sleeve; the edge of the top cover and the edge of the explosion-proof sheet are respectively welded with the thermistor sheet. The lithium battery can be used in a lithium battery.

Description

Battery cover cap assembly and lithium battery

Technical Field

The application relates to the technical field of batteries, in particular to a battery cover cap assembly and a lithium battery.

Background

The battery is used as an energy source, has stable voltage and current, can stably supply power within a certain time, is basically not influenced by external climate, has stable and reliable performance, and plays an indispensable role in a plurality of fields in modern life. Among them, the lithium battery is widely used in various electronic and electrical goods by virtue of advantages of high energy density, light weight, environmental protection, and the like.

The lithium battery mainly comprises a shell and a cap assembly arranged at one end of the shell, wherein the cap assembly mainly comprises a top cover, a thermistor chip, an explosion-proof chip and a pore plate which are sequentially assembled in a sealing sleeve in an overlapping mode. However, the lithium battery usually involves mechanical vibration, collision, dropping and the like during use, which easily has a certain influence on the stability of the internal resistance value of the cap assembly, and may generate fluctuation from several milliohms to several hundred milliohms, and if the internal resistance value of the cap assembly fluctuates too much, the electrical performance and safety performance of the lithium battery are directly affected.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a battery cover cap component and a lithium battery, and is used for solving the problem that the fluctuation of the internal resistance value of the battery cover cap component is large when the lithium battery in the related art is used.

In order to achieve the above object, in a first aspect, an embodiment of the present application provides a battery cap assembly, which includes a sealing sleeve, and a top cap, a thermistor chip, and an explosion-proof chip, which are sequentially disposed in the sealing sleeve along an axial direction of the sealing sleeve; the edge of the top cover and the edge of the explosion-proof sheet are respectively welded with the thermistor sheet.

In a second aspect, an embodiment of the present application provides a lithium battery, including a housing and the battery cap assembly described in the first aspect, the battery cap assembly being mounted at one end of the housing.

The embodiment of the application provides a battery cover cap subassembly and lithium cell, through the edge with the top cap, the edge of explosion-proof piece welds with the thermistor piece respectively mutually, the top cap has been improved like this, the fastness of connecting between explosion-proof piece and the thermistor piece three, so when the lithium cell is receiving mechanical oscillation or collision, just can avoid the top cap, produce between explosion-proof piece and the thermistor piece and become flexible, thereby guarantee the top cap, the stability of the contact resistance value between explosion-proof piece and the thermistor piece, and then guaranteed the stability of this battery cover cap subassembly's internal resistance value, so that this lithium cell has better electrical property.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a cross-sectional view of a battery cap assembly according to some embodiments of the present application;

FIG. 2 is a top view of the top cover of the battery cap assembly of FIG. 1;

FIG. 3 is a top view of a cap welded to a thermistor chip in some embodiments of the present application;

FIG. 4 is a bottom view of the rupture disk of FIG. 1;

fig. 5 is a bottom view of the rupture disc and thermistor disc welded together in some embodiments of the present application.

Detailed Description

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, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

Fig. 1 is a cross-sectional view of a battery cap assembly according to some embodiments of the present application, as shown in fig. 1. The battery cap component comprises a sealing sleeve 1, and a top cap 2, a thermistor chip 3, an explosion-proof chip 4, an insulating ring 6 and an orifice plate 5 which are sequentially arranged in the sealing sleeve 1 along the axial direction of the sealing sleeve 1.

As shown in fig. 1, the sealing sleeve 1 includes an end wall 11 and a side wall 12 surrounding the end wall 11, and a central hole 13 is opened on the end wall 11. The sealing sleeve 1 may be made of an elastic material, such as rubber, etc., and is not limited thereto.

As shown in fig. 1, the top cap 2 functions as a positive terminal in a lithium battery and is made of a conductive material, which may be steel, or other metal or metal alloy material.

In order to facilitate the contact of the top cover 2 with other components to output electric power, the center region of the top cover 2 is projected in a direction away from the thermistor chip 3 to form a first projection 21. Thus, as shown in fig. 1, the member located on the upper side of the top cover 2 is easily brought into contact with the first bosses 21 to electrically connect with the positive electrode terminals of the lithium battery.

The first boss 21 may be a circular truncated cone or a truncated pyramid, and is not limited herein.

As shown in fig. 2, fig. 2 is a top view of the top cover 2 in the battery cap assembly of fig. 1, and the top cover 2 is further provided with a plurality of pressure relief holes 22.

As shown in fig. 1, a through hole 31 is opened in the center region of the thermistor chip 3. The thermistor sheet 3 may be a PTC (Positive Temperature Coefficient) resistor sheet, or may be another type of resistor sheet, and is not limited in particular.

As shown in fig. 1 and 4, fig. 4 is a bottom view of the rupture disk 4 in fig. 1. The explosion-proof sheet 4 is made of a conductive material, such as aluminum or copper, and is not particularly limited herein. The explosion-proof plate 4 is provided with a closed explosion-proof score line 41, and the explosion-proof score line 41 divides the explosion-proof plate 4 into a central portion 42 located inside the explosion-proof score line 41 and an edge portion 43 located outside the explosion-proof score line 41. When the pressure on one side of the rupture disk 4 is greater than the critical value, part or all of the rupture score line 41 can be opened to form a pressure relief opening between the central portion 42 and the edge portion 43 of the rupture disk 4.

The explosion-proof score line 41 may be circular or square, and is not particularly limited herein.

In order to leave a certain deformation space for the central portion of the rupture disc 4 when the rupture score line 41 can be torn, as shown in fig. 1, the rupture disc 4 is protruded to the side away from the thermistor chip 3 to form a second boss 44, and the rupture score line 41 is disposed on the second boss 44. Thus, when the pressure on the side of the rupture disk 4 close to the orifice plate 5 is greater than the critical value, the central portion 42 of the rupture disk 4 can deform into the space surrounded by the second boss 44, so that the pressure relief opening is formed on the rupture disk 4 smoothly.

The second boss 44 may be a circular truncated cone or a truncated pyramid, and is not particularly limited herein.

As shown in fig. 1, the orifice plate 5 is made of a conductive material, such as aluminum or copper, and is not particularly limited thereto. The orifice plate 5 is electrically connected with the explosion-proof sheet 4. The orifice plate 5 and the rupture disk 4 may be electrically connected by welding, or may be electrically connected by being in contact with the rupture disk 4 by pressing, which is not limited herein.

When the rupture disk 4 has the second boss 44, as shown in fig. 1, the central region of the orifice plate 5 protrudes to the side away from the rupture disk 4 to form a third boss 51, so that the second boss 44 of the rupture disk 4 can penetrate into the space surrounded by the third boss 51, thereby better matching the orifice plate 5 with the rupture disk 4.

In order to better limit the orifice plate 5, as shown in fig. 1, the central hole 13 of the sealing sleeve 1 is a stepped hole, and the orifice plate 5 is matched with the central hole 13. The stepped central bore 13 thus limits the axial movement of the orifice plate 5, making the orifice plate 5 more securely fixed.

As shown in fig. 1, the central portion 42 of the rupture disk 4 is welded to the orifice plate 5, specifically, the orifice plate 5 has an orifice plate center hole 52, and the central portion 42 of the rupture disk 4 may be welded to an edge of the orifice plate center hole 52.

As shown in fig. 1, the edge portion 43 of the rupture disc 4 is spaced from the orifice plate 5 by the insulating ring 6. When the pressure inside the lithium battery is higher and exceeds a critical value, the explosion-proof scribed line 41 can be completely opened by the pressure, and the pressure inside the lithium battery is discharged out of the lithium battery through the hole on the pore plate 5, the pressure relief opening on the explosion-proof sheet 4, the through hole 31 on the thermistor sheet 3 and the pressure relief hole 22 on the top cover 2. At this time, the central part 42 and the edge part 43 of the explosion-proof sheet 4 are separated, and the edge part 43 of the explosion-proof sheet 4 is separated from the pore plate 5 by the insulating ring 6, so that the electrical connection between the pore plate 5 and the explosion-proof sheet 4 can be avoided, and the safety of the lithium battery after pressure release is ensured.

Of course, if the tab of the battery cell can be cut off from the top cap 2 by other means after the pressure of the lithium battery is released, the insulating ring 6 may not be provided.

The top cover 2 may be entirely located in a cavity defined by the end wall 11 and the side wall 12, or may be partially located in a cavity defined by the end wall 11 and the side wall 12, which is not particularly limited herein; the orifice plate 5 may be located entirely in the cavity defined by the end wall 11 and the side wall 12, or may be located partially in the cavity defined by the end wall 11 and the side wall 12, which is not limited in this respect.

As shown in fig. 1, the edge of the top cover 2 and the edge of the rupture disk 4 are welded to the thermistor chip 3. Through the edge with top cap 2, the edge of explosion-proof piece 4 welds with thermistor piece 3 mutually respectively, top cap 2 has been improved like this, the fastness of connecting between explosion-proof piece 4 and the thermistor piece 3 three, so when the lithium cell is receiving mechanical oscillation or when colliding, just can avoid top cap 2, produce between explosion-proof piece 4 and the thermistor piece 3 not hard up, thereby guarantee top cap 2, the stability of the contact resistance value between explosion-proof piece 4 and the thermistor piece 3, and then guaranteed the stability of the internal resistance value of this battery cap subassembly, so that this lithium cell has better electrical property.

In some embodiments, as shown in fig. 1, 2 and 3, fig. 3 is a top view of the cap 2 and thermistor chip 3 welded together. The edge of the top cover 2 is provided with a first notch 23 which is sunken towards the center of the top cover 2, and a first welding spot 81 is arranged at a first corner 71 formed by the notch wall of the first notch 23 and the thermistor chip 3 so as to weld the top cover 2 and the thermistor chip 3. By providing the first welding spot 81 at the first corner 71 to weld the top cover 2 to the thermistor chip 3, the first welding spot 81 can be prevented from being misaligned so that the top cover 2 and the thermistor chip 3 are welded together firmly.

In some embodiments, as shown in fig. 1 and 3, a plurality of first welding points 81 are disposed at the first corner 71, and the plurality of first welding points 81 are arranged along the circumferential direction of the first notch 23. Through setting up like this, can increase the welding fastness of top cap 2 with thermistor piece 3 like this to it is not hard up to prevent to appear between top cap 2 and the thermistor piece 3 better.

In some embodiments, as shown in fig. 2 and 3, the number of the first notches 23 is multiple, the multiple first notches 23 are uniformly arranged along the circumferential direction of the top cover 2, that is, the distance between two adjacent first notches 23 in the circumferential direction of the top cover 2 is equal, and a first welding point 81 is arranged at each first notch 23. Through setting up like this, can make top cap 2 in its circumference with thermistor piece 3 even welding to further increase top cap 2 and thermistor piece 3's welding fastness, in order to avoid appearing becoming flexible between top cap 2 and the thermistor piece 3.

In some embodiments, as shown in fig. 2 and 3, the contour of the first notch 23 is rounded. Can avoid first breach 23 to have the edges and corners like this, avoid first breach 23 to appear stress concentration in edges and corners department after the welding to be favorable to improving top cap 2 and thermistor piece 3's welding fastness.

In some embodiments, as shown in fig. 1, 4 and 5, fig. 5 is a bottom view of the explosion-proof disc 4 and the thermistor disc 3 welded together. The edge of the explosion-proof sheet 4 is provided with a second notch 45 which is sunken towards the center of the explosion-proof sheet 4, and a second welding spot 82 is arranged at a second corner 72 formed by the notch wall of the second notch 45 and the thermistor sheet 3 so as to weld the explosion-proof sheet 4 and the thermistor sheet 3. By providing the second welding spot 82 at the second corner 72 to weld the rupture disc 4 and the thermistor chip 3, the second welding spot 82 can be prevented from being misaligned so that the rupture disc 4 and the thermistor chip 3 are welded together firmly.

In some embodiments, as shown in fig. 1 and 5, a plurality of second welding points 82 are disposed at the second corner 72, and the plurality of second welding points 82 are arranged along the circumference of the second gap 45. Through setting up like this, can increase the welding fastness of explosion-proof piece 4 with thermistor piece 3 like this to it is not hard up to prevent better to appear between explosion-proof piece 4 and the thermistor piece 3.

In some embodiments, as shown in fig. 4 and 5, the number of the second notches 45 is multiple, the multiple second notches 45 are uniformly arranged along the circumferential direction of the rupture disk 4, that is, the distance between two adjacent second notches 45 in the circumferential direction of the rupture disk 4 is equal, and a second welding point 82 is arranged at each second notch 45. Through setting up like this, can make explosion-proof piece 4 evenly weld with thermistor piece 3 in its circumference to further increase explosion-proof piece 4 and thermistor piece 3's welding fastness, in order to avoid appearing becoming flexible between explosion-proof piece 4 and the thermistor piece 3.

In some embodiments, as shown in fig. 4 and 5, the contour of the second notch 45 is rounded. Can avoid second breach 45 to have the edges and corners like this, avoid second breach 45 to appear stress concentration in edges and corners department after the welding to be favorable to improving the welding fastness of explosion-proof piece 4 and thermistor piece 3.

As shown in fig. 1, orthographic projections of the first notch 23 and the second notch 45 on the thermistor sheet 3 may overlap each other (that is, the first notch 23 and the second notch 45 correspond to the same position on the thermistor sheet 3 along the circumferential direction of the thermistor sheet 3), and orthographic projections of the first notch 23 and the second notch 45 on the thermistor sheet 3 may not overlap each other, which is not particularly limited herein.

The first notch 23 and the second notch 45 may be formed by a punching process. The top cover 2 and the explosion-proof sheet 4 can be welded with the thermistor sheet 3 through laser welding.

In some embodiments, as shown in fig. 1, the side wall 12 of the sealing sleeve 1 is provided with a limiting protrusion 14, and the limiting protrusion 14 abuts against a side surface of the top cover 2 away from the thermistor chip 3. The end wall 11 of the sealing sleeve 1 is provided with a supporting bulge 15, and the supporting bulge 15 is abutted with the surface of one side of the explosion-proof sheet 4 far away from the thermistor sheet 3. Through setting up like this, spacing arch 14, support arch 15 play spacing effect to top cap 2, the subassembly that explosion-proof piece 4 and thermistor piece 3 formed in the axial of seal cover 1 to avoid top cap 2, explosion-proof piece 4 and thermistor piece 3 to produce in seal cover 1 and rock, improved top cap 2, the laminating degree between explosion-proof piece 4 and the thermistor piece 3 three, and then more be favorable to guaranteeing the stability of this battery cover cap subassembly's internal resistance.

In some embodiments, as shown in fig. 1, the stop protrusion 14 is ring-shaped and is disposed around a circumference of the edge of the top cover 2. Support protrusion 15 is cyclic annular, and a week around the centre bore 13 of seal cover 1 sets up through setting up like this, when top cap 2, the diaphragm subassembly and annular spacing arch 14 that explosion-proof piece 4 and thermistor piece 3 formed, when support protrusion 15 looks butt, can make this diaphragm subassembly atress in week more even, top cap 2 has not only further been improved, laminating degree between explosion-proof piece 4 and the thermistor piece 3 three, but also avoid this diaphragm subassembly to appear the slope better and rock, make top cap 2, explosion-proof piece 4 and thermistor piece 3 three firmly set up in seal cover 1, and then guarantee the stability of the internal resistance value of this battery cover cap subassembly further.

Some embodiments of the present application further provide a lithium battery including a case and the battery cap assembly described in any of the above embodiments.

Wherein, a battery core, electrolyte and the like are arranged in the shell. The battery cap assembly is installed at one end of the housing, specifically, a mounting hole is opened at one end of the housing, and the sealing sleeve 1 is fittingly arranged in the mounting hole.

The housing may be cylindrical, square or rectangular, and is not particularly limited herein.

Other structures of the lithium battery are known to those skilled in the art and will not be described herein.

In the description herein, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery cap component is characterized by comprising a sealing sleeve, and a top cap, a thermistor chip and an explosion-proof chip which are sequentially arranged in the sealing sleeve along the axial direction of the sealing sleeve;

the edge of the top cover and the edge of the explosion-proof sheet are respectively welded with the thermistor sheet.

2. The battery cap assembly of claim 1,

a first notch which is sunken towards the center of the top cover is formed in the edge of the top cover, and a first welding spot is arranged at a first corner formed by the notch wall of the first notch and the thermistor piece so as to weld the top cover and the thermistor piece;

and a second notch which is sunken towards the center of the explosion-proof sheet is formed in the edge of the explosion-proof sheet, and a second welding spot is arranged at a second corner formed by the notch wall of the second notch and the thermistor sheet so as to weld the explosion-proof sheet and the thermistor sheet.

3. The battery cap assembly of claim 2,

the first corner is provided with a plurality of first welding spots, and the first welding spots are distributed along the circumferential direction of the first notch.

4. The battery cap assembly of claim 2,

the second corner is provided with a plurality of second welding spots which are distributed along the circumferential direction of the second gap.

5. The battery cap assembly of claim 2,

the contour lines of the first notch and the second notch are arc-shaped.

6. The battery cap assembly of claim 2,

the number of the first notches is multiple, the first notches are uniformly distributed along the circumferential direction of the top cover, and each first notch is provided with the first welding point;

the number of the second notches is multiple, the second notches are evenly distributed along the circumferential direction of the explosion-proof sheet, and each second notch is provided with a second welding point.

7. The battery cap assembly of any one of claims 1 to 6,

the sealing sleeve comprises an end wall and a side wall surrounding the end wall for one circle, and a central hole is formed in the end wall;

a limiting bulge is arranged on the side wall and is abutted against the surface of one side of the top cover, which is far away from the thermistor chip;

and a support bulge is arranged on the end wall and is abutted against the surface of one side of the explosion-proof sheet far away from the thermistor sheet.

8. The battery cap assembly of claim 7,

the limiting bulge is annular and is arranged around the periphery of the edge of the top cover;

the supporting bulge is annular and is arranged around the center hole in a circle.

9. The battery cap assembly of any one of claims 1 to 6,

the battery cover cap assembly further comprises a pore plate and an insulating ring, and the pore plate is positioned on one side of the explosion-proof sheet far away from the thermistor sheet;

the explosion-proof piece is provided with a closed explosion-proof scribed line, and the explosion-proof scribed line divides the explosion-proof piece into a central part positioned in the explosion-proof scribed line and an edge part positioned outside the explosion-proof scribed line;

the central part of the explosion-proof sheet is welded with the pore plate; the edge part of the explosion-proof sheet is separated from the pore plate by the insulating ring.

10. A lithium battery, comprising:

a housing;

the battery cap assembly of any of claims 1-9, mounted at one end of the housing.