Button cell

Abstract

The utility model discloses a button battery, which relates to the technical field of batteries and comprises a shell, a cover plate and an electrode assembly. The shell is provided with an opening end; the cover plate is connected with the shell, and the shell and the cover plate are made of metal materials; the electrode assembly is connected with the cover plate, and the cover plate and the electrode assembly are matched to seal the opening end; the cover plate is provided with a thin-wall part, the outer contour of the thin-wall part is annular, the thickness of the thin-wall part is smaller than the thickness of the rest part of the cover plate and smaller than the wall thickness of the thinnest part of the shell, and the thin-wall part is communicated with gas pressure in the shell. When the air pressure in the shell is increased, the thin-wall part is subjected to the pressure of the air, the thin-wall part is easier to break through by the air pressure to release the air pressure and realize the explosion-proof effect due to the fact that the structural strength of the thin-wall part is smaller than that of other parts, and the thin-wall part can be formed through punching, so that the forming is convenient, and the cost is low.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a button battery. Background Technology

[0002] Button batteries, also known as coin cells, are batteries that resemble small buttons in shape. They are small in size and widely used in electronic products.

[0003] Figure 16 A cross-sectional schematic diagram of a button battery is shown. The button battery includes a housing 90 with one end open, a cover plate 91 that seals the open end of the housing 90, and an electrode 92 disposed on the cover plate 91. The electrode 92 and the cover plate 91 are separated by an insulating layer 93.

[0004] Button batteries have casings made of metal. To improve battery safety, they typically incorporate explosion-proof structures. However, due to their small size, button batteries cannot accommodate complex explosion-proof valves; therefore, explosion-proof markings (like 94) are usually used for protection. For example... Figures 17 to 18 As shown, Figure 17 for Figure 16 Enlarged view of the middle IV section, Figure 18 yes Figure 16 The diagram shows the positions of the middle insulation layer 93 and the cover plate 91. The battery is designed to prevent explosion by setting explosion-proof markings 94. When the internal pressure of the battery is too high, the explosion-proof markings 94 will break first due to their relatively weak structure, thereby releasing the pressure and preventing an explosion.

[0005] The button cell battery with the above structure still has some defects. For example, during the processing, the explosion-proof etched line 94 needs to be achieved by laser grooving, which requires very high precision to complete the grooving. The dimensions of the formed explosion-proof etched line are unstable, the yield is low, and the equipment used for laser grooving is expensive and the machine maintenance frequency is high.

[0006] For example, machining explosion-proof markings 94 on a flat cover plate 91 is generally more convenient than machining them on a complex housing 90. However, the area on the cover plate 91 where explosion-proof markings 94 can be installed is small. The markings 94 can only be placed on the outside of the insulating layer 93 and the electrode 92; otherwise, they will be obstructed, affecting the explosion-proof effect. Therefore, the area where explosion-proof markings 94 can be installed is quite limited. When explosion-proof markings are placed on the cover plate 91, the positional and dimensional accuracy requirements for the insulating layer 93 and the electrode 92 are high; otherwise, the insulating layer 93 may cover the explosion-proof markings 94, affecting the explosion-proof effect.

[0007] Therefore, it is necessary to improve the existing technology to overcome the aforementioned defects. Utility Model Content

[0008] The purpose of this invention is to provide a button battery that can be easily molded into an explosion-proof structure.

[0009] To achieve the above-mentioned utility model objectives, this utility model proposes a button battery, comprising:

[0010] The casing has an open end;

[0011] A cover plate, connected to the housing, wherein both the housing and the cover plate are made of metal; and,

[0012] An electrode assembly is connected to the cover plate, and the cover plate and the electrode assembly cooperate to seal the opening end;

[0013] The cover plate has a thin-walled portion with an annular outer contour. The thickness of the thin-walled portion is less than the thickness of the rest of the cover plate and less than the wall thickness at the thinnest part of the shell. The thin-walled portion is in communication with the gas pressure inside the shell.

[0014] Furthermore, the electrode assembly includes an electrode element and an insulating layer. The electrode element includes a plate and a column protruding from the middle of the plate. The insulating layer connects the plate and the cover plate and is located inside the housing. The column passes through the insulating layer and the cover plate to be exposed outside the cover plate.

[0015] Furthermore, along the extension direction of the cover plate, the thin-walled portion is completely located inside the outer contour of the insulating layer, and the plate body is provided with a first through hole, the first through hole and the thin-walled portion being at least partially opposite to each other, the insulating layer being made of a soft material, and the area of ​​the thin-walled portion being not less than 0.2 mm. 2 .

[0016] Furthermore, the insulating layer is provided with a second through hole, the second through hole and the thin-walled portion being at least partially opposite to each other and communicating with the first through hole.

[0017] Furthermore, two or all three of the first through hole, the second through hole, and the thin-walled portion are arranged coaxially.

[0018] Furthermore, in the extension direction of the cover plate, the thin-walled portion is at least partially located outside the outer contour of the insulating layer, and the extension direction is perpendicular to the thickness direction of the cover plate.

[0019] Furthermore, the projections of the insulating layer and the plate on the cover plate are entirely within the outer contour of the thin-walled portion, and the plate is provided with a first through hole.

[0020] Furthermore, the insulating layer is provided with a second through hole that communicates with the first through hole.

[0021] Furthermore, the first through hole and the second through hole are arranged on the same axis.

[0022] Furthermore, the insulating layer, the plate, the thin-walled portion, and the cover plate are arranged coaxially, and the distance between the outer diameter of the insulating layer and the plate, which is larger, and the outer edge of the cover plate is no greater than 0.5 mm.

[0023] Furthermore, the thin-walled portion is formed by stamping;

[0024] The inner or outer surface of the cover plate is provided with a recessed area, and the portion of the cover plate corresponding to the position of the recessed area forms the thin-walled portion, which is formed by stamping.

[0025] Furthermore, the thickness of the thin-walled portion is not less than 0.01 mm and not more than 0.05 mm.

[0026] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the button battery includes a thin-walled portion with an annular outer contour. The thickness of the thin-walled portion is less than the thickness of the rest of the cover plate and less than the wall thickness at the thinnest part of the shell. The thin-walled portion is connected to the gas pressure inside the shell. When the gas pressure inside the shell increases, the thin-walled portion will be subjected to gas pressure. Since the structural strength of the thin-walled portion is lower than that of other parts, it is easier to be broken by the gas pressure to release the gas pressure and achieve the explosion-proof effect. Since the thin-walled portion can be stamped by stamping equipment, there is no need to use laser grooving equipment to form explosion-proof lines, so the forming is convenient and the cost is lower. Attached Figure Description

[0027] Figure 1 This is a cross-sectional schematic diagram of a button battery according to an embodiment of the present invention.

[0028] Figure 2 yes Figure 1 The diagram shows the connection between the cover and electrode assembly of the button battery.

[0029] Figure 3 yes Figure 2 The exploded view of the structure shown.

[0030] Figure 4 yes Figure 2 The top view of the structure shown.

[0031] Figure 5 yes Figure 1 Enlarged view of section I in the middle.

[0032] Figure 6 This is a schematic diagram of the structure of the recessed area in one embodiment of the present invention. In the figure, the connecting surface is inclined.

[0033] Figure 7 This is a schematic diagram of the structure of the recessed area in one embodiment of the present invention. In the figure, the connecting surface is arc-shaped.

[0034] Figure 8 yes Figure 1 Enlarged view of section II.

[0035] Figure 9 This is a cross-sectional schematic diagram of the thin-walled portion of one embodiment of the present invention.

[0036] Figure 10 This is a top view of a cover plate and electrode assembly according to an embodiment of the present invention. In the figure, the thin-walled portion is located outside the insulating layer.

[0037] Figure 11 This is a top view of a cover plate and electrode assembly according to an embodiment of the present invention. In the figure, the outer contour of the thin-walled portion surrounds the insulating layer and the plate body.

[0038] Figure 12 yes Figure 11 A cross-sectional schematic diagram of the structure shown.

[0039] Figure 13 yes Figure 12 Enlarged view of Part III.

[0040] Figure 14 yes Figure 13 The diagram shown illustrates the first through hole in the plate.

[0041] Figure 15 yes Figure 14 The diagram shown illustrates the second through-hole in the insulating layer of the structure.

[0042] Figure 16 This is a cross-sectional schematic diagram of the button battery described in the background section.

[0043] Figure 17 yes Figure 16 Enlarged view of the middle IV section.

[0044] Figure 18 yes Figure 16 Schematic diagram showing the positions of the middle cover plate and the insulation layer. Detailed Implementation

[0045] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0046] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0047] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0048] like Figures 1 to 5 As shown, this utility model proposes a button battery, which includes a casing 1, a cover plate 2, and an electrode assembly 3.

[0049] Both the housing 1 and the cover plate 2 are made of metal materials, such as alloy materials, such as stainless steel materials, and more preferably, stainless steel 316L.

[0050] The housing 1 has a receiving space 11 and an opening 10, the opening 10 connecting the receiving space 11 to the outside. A cover plate 2 is connected to the housing 1, and an electrode assembly 3 is connected to the cover plate 2. The cover plate 2 is located at the opening 10, and it cooperates with the electrode assembly 3 to seal the opening 10 of the housing 1 to form a relatively sealed receiving space 11 for placing components such as battery cells.

[0051] The cover plate 2 has a thin-walled portion 20, the outer contour 200 of which is annular. Unlike the traditional linear explosion-proof markings, the outer contour 200 of the thin-walled portion 20 encloses and forms a surface area. The thickness of the thin-walled portion 20 is less than the thickness of the rest of the cover plate 2 and less than the wall thickness of the thinnest part of the housing 1. The thin-walled portion 20 is also in communication with the internal gas pressure of the housing 1.

[0052] The communication between the thin-walled portion 20 and the internal gas pressure of the housing 1 means that the gas pressure within the housing space 11 of the housing 1 can act on the thin-walled portion 20. In some embodiments, the thin-walled portion 20 is in communication with the housing space 11, and is at least partially exposed within the housing space 11, so that the gas pressure of the thin-walled portion 20 and the housing 1 is in communication. In this case, the gas pressure within the housing 1 can directly act on the thin-walled portion 20. In other embodiments, the thin-walled portion 20 and the interior of the housing 1 are separated by a soft material. Since the soft material is relatively weak and easily deformed under the action of gas, it can still transmit gas pressure to the thin-walled portion 20. Therefore, the communication between the thin-walled portion 20 and the housing space 11 of the housing 1 can be achieved by separating the thin-walled portion 20 from the housing space 11 using a soft material.

[0053] Since the thin-walled portion 20 is connected to the internal air pressure of the housing 1, when the internal air pressure of the housing 1 increases, the thin-walled portion 20 will be subjected to gas pressure. Furthermore, since the thickness of the thin-walled portion 20 is smaller than that of the rest of the cover plate 2 and the thinnest part of the housing 1, the structural strength of the thin-walled portion 20 is smaller than that of other parts, making it easier to be broken through by air pressure and release the gas pressure, thus achieving the explosion-proof effect.

[0054] Optionally, the thickness B1 of the thin-walled portion 20 is not less than 0.01 mm, so that the structural strength of the thin-walled portion 20 is not too low, causing the cover plate 2 to be easily damaged. More optionally, the thickness B1 of the thin-walled portion 20 is not greater than 0.05 mm, so that the thin-walled portion 20 can achieve a good explosion-proof effect without being too thick and causing the explosion-proof to become insensitive. More optionally, the thickness B1 of the thin-walled portion 20 is 0.02–0.04 mm.

[0055] In some embodiments, reference Figure 5 The inner surface 22 or outer surface 23 of the cover plate 2 is provided with a recessed area 21. The recessed area 21 makes the thickness of the corresponding part of the cover plate 2 thinner, so the part of the cover plate 2 corresponding to the position of the recessed area 21 will naturally form a thin-walled part 20. The thin-walled part 20 can be formed by stamping. By stamping, the material of a part of the cover plate 2 is squeezed, causing that part to be recessed to form the recessed area 21, thereby forming the recessed area 21 and the thin-walled part 20. Compared with laser equipment, stamping equipment has a relatively low cost, and the stamping process is simpler, which is conducive to reducing costs and improving production efficiency. Moreover, the precision can be controlled by controlling the precision of the stamping die, resulting in better consistency.

[0056] The sidewall of the recessed area 21 has a connecting surface 210 that connects to the thin-walled portion 20. In some embodiments, refer to Figure 5 The connecting surface 210 is perpendicular to the surface 201 (i.e., the bottom surface of the recessed region 21) exposed by the thin-walled portion 20 in the recessed region 21. In other embodiments, reference is made to... Figure 6The connecting surface 210 and the surface 201 of the thin-walled portion 20 exposed in the recessed area 21 are inclined, and the connecting surface 210 is a slope. In some other embodiments, refer to Figure 7 The connecting surface 210 is arc-shaped, and at this time, the sidewall of the recessed area 21 and the thin-walled part 20 are transitioned by the arc surface. The outer contour 200 of the thin-walled part 20 can be understood as the boundary line between the connecting surface 210 and the surface 201, and the area of ​​the thin-walled part 20 is the area of ​​the region enclosed by its outer contour 200.

[0057] Optionally, the connecting surface 210 is also connected to the surface of the cover plate 2 where the recessed area 21 is provided. Figures 5 to 7 In the middle, the connecting surface 210 is connected to the outer surface 23 of the cover plate 2. It can be understood that the recessed area 21 can be set on the inner surface 22 or the outer surface 23 of the cover plate 2. Setting the recessed area 21 on the inner surface 22 of the cover plate 2 can make the button battery look more beautiful.

[0058] The shape of the outer contour 200 of the thin-walled portion 20 is not limited; for example, it can be circular, elliptical, polygonal, etc. It is understood that the shape of the outer contour 200 of the thin-walled portion 20 is related to the pressure required for its rupture. Therefore, the explosion-proof pressure of the button battery can also be adjusted by changing the shape of the thin-walled portion 20. In addition, the explosion-proof pressure (that is, the pressure required for the thin-walled portion 20 to rupture) can also be adjusted by the thickness of the thin-walled portion 20, the area of ​​the thin-walled portion 20, and the shape of the connecting surface 210.

[0059] like Figure 3 and Figure 8 As shown, the electrode assembly 3 includes an electrode 30 and an insulating layer 31. The electrode 30 includes a plate 301 and a column 300 protruding from the center of the plate 301. It is understood that the electrode 30 is made of a conductive material, such as aluminum or other metal. The insulating layer 31 connects the plate 301 and the cover plate 2 and is located inside the housing 1. It serves to separate the plate 301 and the cover plate 2 to provide insulation between them. The insulating layer 31 is made of a soft material, such as hot melt adhesive, or more specifically, PP hot melt adhesive. The plate 301 of the electrode 30 is located inside the housing 1, and its column 300 passes through the insulating layer 31 and the cover plate 2 to be exposed outside the cover plate 2, facilitating connection of external devices to the electrode 30. The cell 4 inside the button cell has two tabs, one connected to the plate 301 and the other connected to the casing 1. Thus, the electrode 30 can serve as the positive (or negative) electrode of the button cell, and the casing 1 or cover 2 can serve as the other electrode. Understandably, to prevent short circuits, the electrode 30 does not contact the cover 2 or the casing 1.

[0060] Optionally, the insulating layer 31, plate 301, thin-walled portion 20, and cover plate 2 are arranged coaxially, and the distance D1 between the outer diameter of the insulating layer 31 and plate 301 and the outer edge of the cover plate 2 is not greater than 0.5 mm. Figure 1 and Figure 4 As shown, Figure 4 It shows Figures 1 to 3 The top view of the cover plate 2 and electrode assembly 3 is shown. The relative positions of the insulating layer 31 and the plate 301 are indicated by dashed lines. The outer diameter of the insulating layer 31 is smaller than the outer diameter of the plate 301. Therefore, the distance D1 between the outer edges of the plate 301 and the cover plate 2 is set to be no more than 0.5 mm.

[0061] The cover plate 2 has an extension direction A, which is a direction perpendicular to the thickness direction B of the cover plate 2. Optionally, the thickness direction B of the cover plate 2 is parallel to the axis of the column 300.

[0062] In some embodiments, reference Figure 4 and Figure 5 In the extension direction A of the cover plate 2, the thin-walled portion 20 is completely located inside the outer contour 311 of the insulating layer 31, and the plate body 301 is provided with a first through hole 3010. The first through hole 3010 and the thin-walled portion 20 are at least partially opposite each other, that is, the projections of the first through hole 3010 and the thin-walled portion 20 along the thickness direction B of the cover plate 2 have an overlapping area, so that the thin-walled portion 20 is separated from the receiving space 11 of the housing 1 by a soft material (i.e., the insulating layer 31). Optionally, the first through hole 3010 and the thin-walled portion 20 are arranged coaxially. In this way, the area of ​​the overlapping area between the first through hole 3010 and the thin-walled portion 20 is larger, and the insulating layer 31 can more reliably transmit gas pressure to the thin-walled portion 20, reducing the gas pressure required for the thin-walled portion 20 to rupture.

[0063] Optionally, the area of ​​the thin-walled portion 20 is not less than 0.2 mm. 2 The smaller the area, the stronger the structural strength of the thin-walled portion 20. Therefore, the area of ​​the thin-walled portion 20 is set to be no less than 0.2 mm. 2 This ensures that the structural strength of the thin-walled section 20 is not too high, thus providing a more reliable explosion-proof effect.

[0064] It is understandable that blocking the insulating layer 31 of the thin-walled portion 20 would increase the gas pressure required for the thin-walled portion 20 to rupture, as in some embodiments, such as Figure 9As shown, the insulating layer 31 is provided with a second through hole 310. The second through hole 310 and the thin-walled portion 20 are at least partially opposite each other and communicate with the first through hole 3010. In this way, the thin-walled portion 20 can be directly connected to the internal space of the housing 1 through the first through hole 3010 and the second through hole 310, reducing the gas pressure required for the thin-walled portion 20 to rupture. Therefore, the second through hole 310 can be selectively opened according to the required explosion-proof pressure. Optionally, two or all three of the first through hole 3010, the second through hole 310 and the thin-walled portion 20 are arranged coaxially. More optionally, all three of the first through hole 3010, the second through hole 310 and the thin-walled portion 20 are arranged coaxially, so that the gas pressure can act on the thin-walled portion 20 more efficiently.

[0065] In some embodiments, in the extension direction A of the cover plate 2, the thin-walled portion 20 is at least partially located outside the outer contour 311 of the insulating layer 31, such that the thin-walled portion 20 is partially in communication with the receiving space 11 of the housing 1.

[0066] For example, Figure 10 In the illustrated embodiment, the thin-walled portion 20 is located outside the outer contour 311 of the insulating layer 31.

[0067] For example, Figures 11 to 13 In the illustrated embodiment, the projection of the insulating layer 31 along the thickness direction B of the cover plate 2 onto the cover plate 2 lies entirely within the outer contour 200 of the thin-walled portion 20, meaning the thin-walled portion 20 surrounds the insulating layer 31. In this case, gas pressure can act from the outer edge of the thin-walled portion 20 to the thin-walled portion 20. Optionally, the projection of the plate body 301 along the thickness direction B of the cover plate 2 onto the cover plate 2 also lies entirely within the outer contour of the thin-walled portion 20, thereby helping to prevent the plate body 301 from contacting the cover plate 2. Further optional, such as... Figure 14 As shown, the plate 301 is provided with a first through hole 3010 to reduce the gas pressure required for the thin-walled portion 20 to rupture. Further optionally, such as... Figure 15 As shown, the insulating layer 31 is provided with a second through hole 310 communicating with the first through hole 3010, so as to further reduce the gas pressure required for the thin-walled portion 20 to rupture. More optionally, the first through hole 3010 and the second through hole 310 are arranged coaxially.

[0068] It should be noted that the thin-walled portion 20 described above is not the only type of explosion-proof structure that can be used on the same button battery. For example, other explosion-proof structures, such as explosion-proof markings, can also be provided at the same time.

[0069] The above are merely specific embodiments of this utility model. Any improvements made based on the concept of this utility model shall be considered within the scope of protection of this utility model.

Claims

1. A button battery, characterized in that, include: The housing (1) has an open end (10); A cover plate (2) is connected to the housing (1), and the housing (1) and the cover plate (2) are made of metal; and, The electrode assembly (3) is connected to the cover plate (2), and the cover plate (2) and the electrode assembly (3) cooperate to seal the opening end (10); The cover plate (2) is provided with a thin-walled part (20), the outer contour (200) of the thin-walled part (20) is annular, the thickness of the thin-walled part (20) is less than the thickness of the rest of the cover plate (2) and less than the wall thickness of the thinnest part of the shell (1), and the thin-walled part (20) is in communication with the gas pressure inside the shell (1).

2. The button battery as described in claim 1, characterized in that, The electrode assembly (3) includes an electrode (30) and an insulating layer (31). The electrode (30) includes a plate (301) and a column (300) protruding from the middle of the plate (301). The insulating layer (31) is connected between the plate (301) and the cover plate (2) and is located inside the housing (1). The column (300) passes through the insulating layer (31) and the cover plate (2) to be exposed outside the cover plate (2).

3. The button battery as described in claim 2, characterized in that, Along the extension direction of the cover plate (2), the thin-walled portion (20) is completely located inside the outer contour of the insulating layer (31), and the plate body (301) is provided with a first through hole (3010). The first through hole (3010) and the thin-walled portion (20) are at least partially opposite to each other. The insulating layer (31) is made of a soft material, and the area of ​​the thin-walled portion (20) is not less than 0.2 mm. 2 .

4. The button battery as described in claim 3, characterized in that, The insulating layer (31) is provided with a second through hole (310), and the second through hole (310) and the thin-walled portion (20) are at least partially opposite to each other and communicate with the first through hole (3010).

5. The button battery as described in claim 4, characterized in that, Two or all of the first through hole (3010), the second through hole (310), and the thin-walled portion (20) are arranged coaxially.

6. The button battery as described in claim 2, characterized in that, In the extension direction of the cover plate (2), the thin-walled portion (20) is at least partially located outside the outer contour of the insulating layer (31), and the extension direction is perpendicular to the thickness direction of the cover plate (2).

7. The button battery as described in claim 6, characterized in that, The projections of the insulating layer (31) and the plate (301) on the cover plate (2) are completely within the outer contour of the thin-walled portion (20), and the plate (301) is provided with a first through hole (3010).

8. The button battery as described in claim 7, characterized in that, The insulating layer (31) is provided with a second through hole (310) that communicates with the first through hole (3010).

9. The button battery as described in claim 8, characterized in that, The first through hole (3010) and the second through hole (310) are arranged on the same axis.

10. The button battery as claimed in claim 7, characterized in that, The insulating layer (31), the plate (301), the thin-walled portion (20) and the cover plate (2) are arranged on the same axis, and the distance between the outer diameter of the insulating layer (31) and the plate (301) and the outer edge of the cover plate (2) is no greater than 0.5 mm.

11. The button battery according to any one of claims 1 to 10, characterized in that, The thin-walled portion (20) is formed by stamping; The inner surface (22) or outer surface (23) of the cover plate (2) is provided with a recessed area (21), and the portion of the cover plate (2) corresponding to the position of the recessed area (21) forms the thin-walled portion (20), and the recessed area (21) is formed by stamping.

12. The button battery as claimed in claim 10, characterized in that, The thickness of the thin-walled portion (20) is not less than 0.01 mm and not more than 0.05 mm.

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