CN216251004U

CN216251004U - Explosion-proof device and battery cell

Info

Publication number: CN216251004U
Application number: CN202122494844.4U
Authority: CN
Inventors: 范辉贤; 李纾黎; 夏信德
Original assignee: He'nan Penghui Power Supply Co ltd
Current assignee: He'nan Penghui Power Supply Co ltd
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-04-08
Anticipated expiration: 2031-10-15

Abstract

The utility model provides an explosion-proof device and a battery cell, and relates to the technical field of lithium batteries, wherein the explosion-proof device comprises a battery top cover, an explosion-proof valve and a protective film, wherein the explosion-proof valve is used for relieving the pressure inside the battery; the protective film, the explosion-proof valve and the hole wall of the air hole form a cavity together; and a channel for connecting the cavity with the outside is arranged between the protective film and the battery top cover. The channel is arranged between the battery top cover and the explosion-proof membrane of the explosion-proof device, so that a cavity defined by the protective membrane, the explosion-proof valve and the hole wall of the air hole can be communicated with the outside atmosphere through the channel, stable air pressure in the cavity is further ensured, and the situation that the protective membrane is separated from the battery top cover by the gas in the cavity when a battery cell is compressed and the protective membrane cannot protect the explosion-proof valve can be avoided.

Description

Explosion-proof device and battery cell

Technical Field

The utility model relates to the technical field of lithium batteries, in particular to an explosion-proof device and a battery cell.

Background

The battery top cover generally comprises a top cover plate, a pole, upper plastic, lower plastic, an explosion-proof valve, a binder and an explosion-proof valve protective film. The function of the explosion-proof valve on the battery is mainly that when the battery core is abnormal, the battery core of the explosion-proof valve is opened to release pressure, so that great harm caused by overlarge air pressure is prevented.

The air pressure generated when the battery cell is normally used is less than the air pressure generated when the explosion-proof valve is opened and less than the air pressure generated when the aluminum shell is withstand voltage and the air pressure generated when the welding seam is sealed.

In order to avoid the pollution of foreign substances to the explosion-proof valve, the explosion-proof valve is corroded to cause the attenuation of an explosion value; and adding an explosion-proof valve protective film on the surface of the explosion-proof valve, wherein the protective film needs to be back-glued and is attached above the top cover plate corresponding to the position of the explosion-proof valve.

The addition of an explosion-proof valve protective film can cause two problems: firstly, when the top cover is fed, the gas leakage of the explosion-proof valve cannot be detected through helium detection, and finally the leakage of finished product battery cells is scrapped; secondly, when the battery cell contracts, air between the explosion-proof valve and the protective film is compressed and cannot be equivalent to atmospheric pressure, and the protective film can be expanded.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an explosion-proof device and a battery cell, which are used for relieving the technical problem that a protective film and an explosion-proof valve form a closed cavity, and the protective film is easy to open when the battery cell contracts, so that foreign substances cannot be prevented from polluting the explosion-proof valve.

In a first aspect, the utility model provides an explosion-proof device, which comprises a battery top cover, an explosion-proof valve for decompressing the interior of a battery and a protective film;

the battery top cover is provided with air holes, the explosion-proof valve covers the air holes, and the periphery of the explosion-proof valve is fixed on the inner surface of the battery top cover;

the protective film is fixed on the outer surface of the battery top cover and covers the air holes; the protective film, the explosion-proof valve and the hole wall of the air hole form a cavity together;

and a channel for connecting the cavity with the outside is arranged between the protective film and the battery top cover.

In an alternative embodiment, an adhesive is applied between the protective film and the cell top cover, the adhesive forming a bonding layer for bonding the protective film to the cell top cover.

In an optional embodiment, the adhesive layer is disposed along a circumferential direction of the air holes, and at least one notch for forming the channel is disposed on the adhesive layer.

In an optional embodiment, a ventilation groove is formed in the battery top cover, a notch of the adhesive layer is arranged corresponding to the ventilation groove, and the notch and the ventilation groove together form the channel.

In an alternative embodiment, the thickness of the adhesive layer is between 0 and 5 mm.

In an alternative embodiment, the length of the gas permeation groove is greater than the width of a contact portion of the protective film with the top cap of the battery.

In an alternative embodiment, the battery top cover is provided with a vent groove, and the vent groove forms the channel.

In an alternative embodiment, the vent groove on the battery top cover is arranged on one side of the vent hole far away from the liquid injection hole.

In an alternative embodiment, the distance between the bottom of the gas-permeable groove and the protective film is 0.5-2 mm.

The channel is arranged between the battery top cover and the explosion-proof membrane of the explosion-proof device, so that a cavity defined by the protective membrane, the explosion-proof valve and the hole wall of the air hole can be communicated with the outside atmosphere through the channel, stable air pressure in the cavity is further ensured, and the situation that the protective membrane is separated from the battery top cover by the gas in the cavity when a battery cell is compressed and the protective membrane cannot protect the explosion-proof valve can be avoided.

In a second aspect, the utility model provides a battery cell, which includes the explosion-proof device in any one of the foregoing embodiments.

The utility model also provides a battery cell which adopts the anti-explosion device, so that all the beneficial effects of the anti-explosion device are achieved.

Drawings

In order to more clearly illustrate the embodiments of the present invention 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, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is an exploded view of an explosion protection device provided in an embodiment of the present invention;

FIG. 2 is an exploded view of an alternative construction of an explosion vent apparatus according to an embodiment of the present invention;

FIG. 3 is an exploded view of yet another configuration of an explosion vent in accordance with an embodiment of the present invention;

FIG. 4 is a schematic structural view of a cross section of the explosion vent shown in FIG. 3;

fig. 5 is a partially enlarged view a of a structural schematic view in section of the explosion-proof valve device of fig. 4.

Icon: 100-a battery top cover; 101-a ventilation groove; 200-air holes; 300-protective film; 400-a glue layer; 401-notch; 500-explosion-proof valve; 600-liquid injection hole; 700-chamber.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. 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 invention.

Example 1

Referring to fig. 1 to 5, the present invention provides an explosion proof device, including a battery top cover 100, an explosion proof valve 500 for releasing pressure inside the battery, and a protective film 300;

the battery top cover 100 is provided with air holes 200, the explosion-proof valve 500 covers the air holes 200, and the periphery of the explosion-proof valve 500 is fixed on the inner surface of the battery top cover 100;

the protective film 300 is fixed on the outer surface of the battery top cover 100 and covers the vent holes 200; the hole walls of the protective film 300, the explosion-proof valve 500 and the air holes 200 form a cavity 700;

a passage for connecting the chamber 700 to the outside is provided between the protective film 300 and the battery top cover 100.

In some embodiments, the battery top cover 100 is provided with the vent holes 200, and the vent holes 200 are generally elongated holes; after the battery top cover 100 is assembled into a battery core, the exposed part is the outer surface, and the part inside the battery core is the inner surface; the protective film 300 is fixed to the outer surface of the battery top cap 100, the explosion-proof valve 500 is fixed to the inner surface of the battery top cap 100, the explosion-proof valve 500 is generally connected to the battery top cap 100 by welding, and the protective film 300 is connected to the battery top cap 100 by adhesion.

A passage is arranged between the protective film 300 and the battery top cover 100, and the passage enables the protective film 300, the explosion-proof valve 500 and the hole wall of the air vent 200 to jointly enclose a cavity 700 communicated with the outside atmosphere; when the battery core expands or contracts, gas in the cavity 700 can enter the cavity 700 through the channel, so that the cavity 700 has the same atmospheric pressure as the outside, and the phenomenon that the pressure in the cavity 700 is too large or too small is avoided, so that the protective film 300 is separated from the battery top cover 100, the protective film 300 is protected by the explosion-proof film, and foreign matters enter the air holes 200 to influence the service life of the explosion-proof valve 500.

After the passage is provided between the protective film 300 and the cell top cover 100, it is possible to detect whether the explosion-proof valve 500 is welded to leak gas by helium inspection when the cell top cover 100 is supplied.

In an alternative embodiment, an adhesive is applied between the protective film 300 and the battery top cover 100, and the adhesive constitutes an adhesive layer 400 for adhering the protective film 300 to the battery top cover 100.

Referring to fig. 1 and 3, in an alternative embodiment, the adhesive layer 400 is disposed along a circumferential direction of the airing hole 200, and at least one notch 401 for forming the passage is provided on the adhesive layer 400.

In some embodiments, the battery top cap 100 is coated with an adhesive to fix the protective film 300 to the battery top cap 100, the adhesive forming the adhesive layer 400 on the battery top cap 100; the adhesive layer 400 does not form a complete ring shape along the airing hole 200; a gap 401 is formed on the adhesive layer 400, and the gap 401 forms a passage through which the chamber 700 communicates with the outside.

The adhesive may be glue, double-sided tape, or the like, and may be another adhesive substance capable of adhering the protective film 300 to the battery top cap 100.

Referring to fig. 2 to 5, in an alternative embodiment, a ventilation groove 101 is formed in the battery top cover 100, and a notch 401 of the adhesive layer 400 is formed corresponding to the ventilation groove 101, and the notch 401 and the ventilation groove 101 together form the channel.

In order to better form and stabilize the channel between the protective film 300 and the battery top cover 100, the battery top cover 100 is provided with a ventilation groove 101, and the ventilation groove 101 and the notch 401 form the channel together; in order to prevent the instability of the notch 401 formed in the adhesive layer 400, the gas permeation groove 101 is formed in the battery top cap 100.

In an alternative embodiment, the thickness of the adhesive layer 400 is 0-5 mm.

The thickness of the adhesive layer 400 is 0-5mm, and since the thickness of the adhesive layer 400 is not easy to control, the thickness of the adhesive layer 400 has a wide range; when the air permeation groove 101 and the notch 401 form a channel together, the depth of the air permeation groove 101 may be 0.05mm, and the thickness of the adhesive layer 400 is 0.05-1 mm.

In an alternative embodiment, the length of the gas permeation groove 101 is greater than the width of a portion of the protective film 300 contacting the battery top cap 100.

In an alternative embodiment, the battery top cover 100 is provided with a gas permeation groove 101, and the gas permeation groove 101 forms the channel.

In some embodiments, when the protective film 300 is adhered to the battery top cover 100, the protective film 300 does not completely cover the vent groove 101 formed in the battery top cover 100, and one end of the vent groove 101, which is far away from the vent hole 200, is exposed; this ensures that the channels formed by the ventilation slots 101 are open to the outside atmosphere.

The air permeable groove 101 can be formed in the battery top cover 100 independently, and the air permeable groove 101 formed in the battery top cover 100 can control the size of the channel more accurately because the height of the adhesive layer 400 is not easy to control relative to the depth of the air permeable groove 101.

In an alternative embodiment, the ventilation groove 101 on the battery top cover 100 is arranged on the side of the ventilation hole 200 far away from the liquid injection hole 600, so that the electrolyte can be prevented from being directly sprayed to the ventilation groove 101 during the liquid injection of the battery core.

In an alternative embodiment, the distance between the bottom of the gas-permeable groove 101 and the protective film 300 is 0.5 to 2 mm.

The ventilation groove 101 on the battery top cover 100 and the notch 401 of the adhesive layer 400 form channels respectively, or the ventilation groove 101 and the notch 401 form channels together, and the size of the channels is also influenced by the number of the channels on the explosion-proof device; when a plurality of channels are provided on the explosion-proof device, the channels may be relatively small, that is, the distance between the bottom of the air-permeable groove 101 and the protective film 300 is relatively small, and when a small number of channels are provided, the distance between the bottom of the air-permeable groove 101 and the protective film 300 is relatively large.

The channel is arranged between the battery top cover 100 and the explosion-proof membrane of the explosion-proof device, so that the protective membrane 300, the explosion-proof valve 500 and the hole wall of the air hole 200 together form a cavity 700 which can be communicated with the outside atmosphere through the channel, and further stable air pressure in the cavity 700 is ensured, and further the situation that when a battery core is compressed, the protective membrane 300 is separated from the battery top cover 100 by the gas in the cavity 700 and the protective membrane 300 cannot play a role in protecting the explosion-proof valve 500 can be avoided.

Example 2

The utility model provides a battery cell which comprises the explosion-proof device in any one of the above embodiments.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the utility model has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An explosion-proof device is characterized by comprising a battery top cover (100), an explosion-proof valve (500) for decompressing the interior of a battery and a protective film (300);

the battery top cover (100) is provided with air holes (200), the explosion-proof valve (500) covers the air holes (200), and the periphery of the explosion-proof valve (500) is fixed on the inner surface of the battery top cover (100);

the protective film (300) is fixed on the outer surface of the battery top cover (100) and covers the air holes (200); the hole walls of the protective film (300), the explosion-proof valve (500) and the air vent (200) jointly enclose a cavity (700);

a channel for connecting the chamber (700) to the outside is provided between the protective film (300) and the battery top cover (100).

2. Explosion vent according to claim 1, characterized in that an adhesive is applied between the protective film (300) and the cell top cover (100), said adhesive constituting an adhesive layer (400) for adhering the protective film (300) to the cell top cover (100).

3. The explosion-proof device according to claim 2, wherein the adhesive layer (400) is disposed along a circumferential direction of the vent hole (200), and at least one notch (401) for forming the passage is provided on the adhesive layer (400).

4. The explosion-proof device according to claim 3, wherein the battery top cover (100) is provided with a ventilation groove (101), a notch (401) of the adhesive layer (400) is arranged corresponding to the ventilation groove (101), and the notch (401) and the ventilation groove (101) jointly form the channel.

5. Explosion protection device according to claim 2, wherein the thickness of the adhesive layer (400) is between 0 and 5 mm.

6. Explosion vent according to claim 4, characterized in that the length of the venting groove (101) is greater than the width of the contact portion of the protective film (300) with the cell top cover (100).

7. Explosion vent according to claim 1, characterized in that a venting groove (101) is provided on the battery top cover (100), and the venting groove (101) forms the channel.

8. The explosion protection device according to claim 4 or 7, wherein the vent groove (101) on the battery top cover (100) is provided on a side of the vent hole (200) away from the liquid injection hole (600).

9. Explosion protection device according to claim 4 or 7, wherein the distance between the bottom of the gas-permeable groove (101) and the protective film (300) is 0.5-2 mm.

10. A battery cell comprising the explosion-proof device of any one of claims 1-9.