Secondary battery with automatic current cut-off device

Abstract

The utility model discloses a secondary battery with an automatic current cut-off device, which comprises a battery body, a lug seat and a power-off component, and a top cover is arranged at the top of the battery body. The top cover comprises an insulating layer and is provided with a mounting groove. And a ventilation channel is arranged at the bottom of the mounting groove. The ventilation channel penetrates through the top cover layer. And the tab seat is arranged below the top cover and is propped against the top cover. The power-off assembly comprises an overturning piece. The turnover piece is arranged in the mounting groove, the central part of the turnover piece is convexly arranged close to the tab seat along the axial direction, the ventilation channel can be used as a liquid injection port of the secondary battery, and when the interior of the secondary battery is in a high-voltage environment, the central part of the turnover piece is disconnected from the bottom of the mounting groove and is turned over outwards, so that the effect of cutting off current is achieved; meanwhile, the functions of an anti-explosion valve and an automatic current cut-off device are achieved. According to the device, the explosion-proof valve, the current automatic cut-off device and the liquid injection port are integrated, so that the thickness of the top cover is reduced, the internal space of the battery is liberated, and the energy density of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a secondary battery with an automatic current cut-off device. Background Art

[0002] In the prior art, lithium-ion secondary batteries need to prevent overcharging and explosion during battery thermal runaway. An explosion-proof valve and an automatic current cut-off device need to be provided at the top cover, and a liquid injection port also needs to be reserved. The stacking of these complex structures will increase the thickness of the top cover and occupy a lot of internal space of the battery, thus reducing the energy density of the battery. Summary of the Utility Model

[0003] To overcome the above-mentioned drawbacks, the purpose of the utility model is to provide a secondary battery with an automatic current cut-off device to solve the problems caused in the above-mentioned background art.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is a secondary battery with an automatic current cut-off device, including:

[0005] A battery body extending along the axial direction, with a top cover provided at the top.

[0006] The top cover includes an insulating layer and is provided with a mounting groove. A ventilation channel is provided at the bottom of the mounting groove. The ventilation channel penetrates through the top cover layer.

[0007] An ear seat is provided below the top cover and is in contact with the bottom of the top cover.

[0008] A power-off component includes a flipping piece. The flipping piece is arranged in the mounting groove, and the central part protrudes along the axial direction close to the ear seat and is connected to the bottom of the mounting groove for closing the ventilation channel. When the pressure inside the battery body is too high, the central part flips along the axial direction away from the ear seat.

[0009] The secondary battery with an automatic current cut-off device provided by the utility model, by providing a mounting groove with a ventilation channel in the top cover, the ventilation channel can be used as the liquid injection port of the secondary battery. The ear seat is electrified and in contact with the bottom of the top cover. Since an insulating layer is provided in the top cover, the central part of the flipping piece can be conductive only after being connected to the bottom of the mounting groove. Therefore, by using the feature that the flipping piece can flip, when the inside of the secondary battery is in a high-pressure environment, the central part of the flipping piece disconnects from the bottom of the mounting groove and flips outwards, thereby achieving the effect of current cut-off and simultaneously playing the roles of an explosion-proof valve and an automatic current cut-off device.

[0010] In some embodiments, the top cover further includes a first sealing layer and a second sealing layer, and the first sealing layer and the second sealing layer are respectively disposed on the upper and lower sides of the insulating layer. The first sealing layer is provided with a first through hole, and the insulating layer is provided with a corresponding second through hole. The first through hole, the second through hole, and the second sealing layer define the mounting groove. The ventilation channel is disposed in the second sealing layer and is correspondingly arranged with the second through hole. The central portion is connected to the second sealing layer.

[0011] In some embodiments, a stepped portion is provided at the top edge of the first through hole for supporting and sealingly connecting to the edge portion of the flipping piece.

[0012] With the above technical solution, the first sealing layer and the second sealing layer are conductive layers, and the insulating layer isolates the two conductive layers. The flipping piece is set as the connecting member between the first sealing layer and the second sealing layer. In the normal state, the central portion of the flipping piece is connected to the second sealing layer to connect the two conductive layers. When in the high-voltage state, the central portion of the flipping piece flips to disconnect the connection between the first sealing layer and the second sealing layer, thereby achieving the effect of current cut-off. Specifically, the edge portion of the flipping piece is welded to the stepped portion.

[0013] In some embodiments, the flipping piece includes a flipping score line. Along the axial direction, on the side of the flipping piece facing the tab seat, the flipping score line is disposed at a position of the central portion close to the edge portion and is arranged in a circumferential manner around the central portion, and the circumferential direction surrounds the axial direction.

[0014] With the above technical solution, the setting of the flipping score line makes the position where it is located more fragile than other parts of the flipping piece. When the pressure in the secondary battery further increases to the overpressure state, the central portion can burst along the flipping score line to release pressure.

[0015] In some embodiments, the power-off assembly further includes a cap. The cap is disposed on the top of the first sealing layer and is correspondingly arranged with the flipping piece. The cap protrudes away from the flipping piece along the axial direction for protection when the flipping piece flips.

[0016] With the above technical solution, the cap is used to protect the flipping piece and protrudes outward in cooperation with the flipping piece in the high-voltage state. When in the overpressure state, the cap separates from the first sealing layer to release pressure.

[0017] In some embodiments, the ventilation channel includes a plurality of ventilation holes, and the plurality of ventilation holes are arranged around the connection between the central portion and the second sealing layer.

[0018] With the above technical solution, the plurality of ventilation holes can be used both as a liquid injection port and as a guiding channel for air pressure.

[0019] In some embodiments, the connection between the central part and the second sealing layer is connected by spot welding.

[0020] With the above technical solution, the central part of the spot welding and the second sealing layer not only ensure the connection between the first sealing layer and the second sealing layer, but also enable the flipping piece to be easily separated and flipped under high pressure.

[0021] In some embodiments, the material of the insulating layer is one of polyvinyl chloride, polyethylene or polypropylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. is a perspective view of an embodiment of a secondary battery with an automatic current cut-off device according to the present invention;

[0023] Figure 2 FIG. is a partial structural schematic diagram of an embodiment of a secondary battery with an automatic current cut-off device according to the present invention Figure 1 ;

[0024] Figure 3 FIG. is a partial structural schematic diagram of an embodiment of a secondary battery with an automatic current cut-off device according to the present invention Figure 2 ;

[0025] Figure 4 FIG. is a perspective view of a flipping piece of an embodiment of a secondary battery with an automatic current cut-off device according to the present invention;

[0026] In the figure:

[0027] 1 - battery body; 10 - top cover; 100 - insulating layer; 101 - first sealing layer; 102 - second sealing layer; 11 - mounting groove; 12 - ventilation channel; 120 - ventilation hole; 130 - step portion; 2 - tab seat; 3 - power-off assembly; 30 - flipping piece; 300 - central part; 301 - edge part; 302 - flipping score line; 31 - cap. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following describes in detail the preferred embodiments of the present invention with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0029] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification.

[0030] It should be noted that in the description of the present utility model, it should be stated that for the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present utility model is usually placed during use. It is only for the convenience of describing the present utility model 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 to the present utility model. In addition, the terms "first", "second", "third", etc. are only used for differential description and cannot be understood as indicating or implying relative importance. The terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0031] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0032] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the protection scope of the present application; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0033] Reference Figures 1 to 2 , Figure 1 shows a perspective view of a secondary battery equipped with an automatic current cut-off device provided by an embodiment of the present utility model; Figure 2 shows a structural schematic of a secondary battery equipped with an automatic current cut-off device provided by an embodiment of the present utility model Figure 1 ; Figure 3 shows a structural schematic of a secondary battery equipped with an automatic current cut-off device provided by an embodiment of the present utility model Figure 2 ; Figure 2Shows a three-dimensional view of the flip piece 30 in an automatic current cut-off device provided by an embodiment of the present utility model.

[0034] As Figures 1 to 4 shown, the technical solution provided by the present application is a secondary battery with an automatic current cut-off device, including a battery body 1, a tab seat 2, and a power-off component 3. Among them, the battery body 1 extends along the axial direction ( Figure 1 as shown by the Z direction in the figure), and a top cover is provided at the top. The top cover includes an insulating layer 100 and is provided with an installation groove. The bottom of the installation groove is provided with a ventilation channel 12. The ventilation channel 12 penetrates through the top cover layer. The tab seat 2 is arranged below the top cover and is in contact with the top cover. The power-off component 3 includes a flip piece 30. The flip piece 30 is arranged in the installation groove, and the central part 300 protrudes along the axial direction close to the tab seat 2 and is connected to the bottom of the installation groove for closing the ventilation channel 12. When the pressure in the battery body 1 is too high, the central part 300 flips along the axial direction away from the tab seat 2.

[0035] For the secondary battery with an automatic current cut-off device provided by the present application, by setting an installation groove with a ventilation channel 12 in the top cover, the ventilation channel 12 can be used as the liquid injection port of the secondary battery. The tab seat 2 is electrified and abuts against the bottom of the top cover. Since the top cover is provided with an insulating layer 100, the central part 300 of the flip piece 30 can conduct electricity only after being connected to the bottom of the installation groove. Therefore, by utilizing the flipable characteristic of the flip piece 30, when the secondary battery is in a high-pressure environment, the central part 300 of the flip piece 30 disconnects from the bottom of the installation groove and flips outwards, thereby achieving the effect of current cut-off, and at the same time playing the role of an explosion-proof valve and an automatic current cut-off device. This device integrates the explosion-proof valve, the automatic current cut-off device, and the liquid injection port in one place, thereby reducing the overall required space, reducing the thickness of the top cover, liberating the space inside the battery, and improving the energy density of the battery.

[0036] In some embodiments, referring to Figures 1 to 4 , the top cover further includes a first sealing layer 101 and a second sealing layer 102. The first sealing layer 101 and the second sealing layer 102 are respectively arranged on the upper and lower sides of the insulating layer 100. The first sealing layer 101 is provided with a first through hole, and the insulating layer 100 is provided with a corresponding second through hole. The first through hole, the second through hole, and the second sealing layer 102 enclose the installation groove. The ventilation channel 12 is arranged in the second sealing layer 102 and is correspondingly arranged with the second through hole. The central part 300 is connected to the second sealing layer 102.

[0037] The top edge of the first through hole is provided with a step portion 130 for carrying and sealingly connecting with the edge portion 301 of the flip piece 30.

[0038] Exemplarily, the first sealing layer 101 and the second sealing layer 102 are conductive layers, and the insulating layer 100 isolates the two conductive layers. The flipping piece 30 is set as a connecting member between the first sealing layer 101 and the second sealing layer 102. In the normal state, the central part 300 of the flipping piece 30 is connected to the second sealing layer 102 to connect the two conductive layers. When in the high-voltage state, the central part 300 of the flipping piece 30 flips to disconnect the connection between the first sealing layer 101 and the second sealing layer 102, thereby achieving the effect of current cut-off. Specifically, the edge part 301 of the flipping piece 30 is welded to the stepped part 130.

[0039] In some embodiments, referring to Figures 1 to 4 , the flipping piece 30 includes a flipping score line 302. Along the axial direction, on the side of the flipping piece 30 facing the tab seat 2, the flipping score line 302 is arranged at a position of the central part 300 close to the edge part 301 and is arranged in a circumferential direction ( Figure 1 as shown by the θ direction in

[0040] ) around the central part 300, and the circumferential direction surrounds the axial direction.

[0041] In some embodiments, referring to Figures 1 to 4 , the power-off assembly 3 further includes a cap 31. The cap 31 is arranged on the top of the first sealing layer 101 and is correspondingly arranged with the flipping piece 30. The cap 31 protrudes axially away from the flipping piece 30 and is used for protection when the flipping piece 30 flips.

[0042] Exemplarily, the cap 31 is used to protect the flipping piece 30 and cooperates with the flipping piece 30 in the high-voltage state to protrude outward. When in the overpressure state, the cap 31 is separated from the first sealing layer 101 for pressure relief.

[0043] In some embodiments, referring to Figures 1 to 4 , the ventilation channel 12 includes a plurality of ventilation holes 120, and the plurality of ventilation holes 120 are arranged around the connection part of the central part 300 and the second sealing layer 102.

[0044] Exemplarily, the plurality of ventilation holes 120 can be used both as liquid injection ports and as air pressure guiding channels.

[0045] In some embodiments, the connection part of the central part 300 and the second sealing layer 102 is connected by spot welding.

[0046] Exemplarily, the central portion 300 of the spot weld not only ensures the connection between the first sealing layer 101 and the second sealing layer 102, but also enables the flipping piece 30 to be easily separated and perform a flipping action under high pressure.

[0047] In some embodiments, the insulating layer 100 is made of one of polyvinyl chloride, polyethylene, or polypropylene.

[0048] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A secondary battery with an automatic current cut-off device, characterized in that: include: The battery body extends axially and is provided with a top cover on the top; The top cover includes an insulating layer and is provided with a mounting groove; a ventilation channel is provided at the bottom of the mounting groove; the ventilation channel is provided through the top cover layer; A pole lug seat is disposed below the top cover and is disposed in contact with the top cover; The power-off assembly includes a flip plate; the flip plate is arranged in the installation groove, and the central part protrudes along the axial direction close to the pole lug seat and is connected to the bottom of the installation groove, so as to close the air permeable channel. When the pressure in the battery body is too large, the central part flips along the axial direction away from the pole lug seat.

2. The secondary battery with an automatic current cutoff device according to claim 1, characterized in that: The top cover also includes a first sealing layer and a second sealing layer, which are respectively arranged on the upper and lower sides of the insulating layer; the first sealing layer is provided with a first through hole, and the insulating layer is provided with a corresponding second through hole, and the first through hole, the second through hole and the second sealing layer form the installation groove; the air permeable channel is arranged in the second sealing layer and corresponds to the second through hole; the central part is connected to the second sealing layer.

3. The secondary battery with an automatic current cutoff device according to claim 2, characterized in that: A step portion is provided on the top edge of the first through hole for supporting the edge portion of the flip sheet and being sealed therewith.

4. The secondary battery with an automatic current cutoff device according to claim 1, characterized in that: The flip sheet includes a flip engraved line; along the axial direction, the flip sheet faces the side of the pole lug seat, and the flip engraved line is arranged at a position close to the edge of the center portion and is arranged circumferentially, and the circumference surrounds the axial direction.

5. The secondary battery with an automatic current cutoff device according to claim 2, characterized in that: The power-off assembly further includes a cap; the cap is disposed on the top of the first sealing layer and is disposed corresponding to the flip sheet; the cap is disposed to protrude away from the flip sheet along the axial direction and is used for protecting the flip sheet when it flips.

6. The secondary battery with an automatic current cutoff device according to claim 2, characterized in that: The ventilation channel includes a plurality of ventilation holes, and the plurality of ventilation holes are arranged around the connection between the central portion and the second sealing layer.

7. The secondary battery with an automatic current cutoff device according to claim 6, characterized in that: The connection between the central portion and the second sealing layer is connected by spot welding.

8. The secondary battery with an automatic current cutoff device according to claim 1, characterized in that: The insulating layer is made of polyvinyl chloride, polyethylene or polypropylene.

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