A high voltage differential triggered explosion-proof sheet for lithium batteries

Abstract

This utility model provides a high-pressure differential triggered lithium battery explosion-proof sheet, relating to the field of lithium battery explosion-proof technology. It includes a sheet body with an arc-shaped top cover and serrated lines on the outer side of the top cover. A fixing ring is located on the outer side of the top of the sheet body. A diaphragm is located at the bottom of the sheet body, and a cavity is located at the bottom of the sheet body. A supporting frame is located inside the cavity, and a base plate is located at the bottom of the inner part of the sheet body. A spiral hole is located at the bottom of the base plate. By employing the supporting frame, when the internal gas of the lithium battery increases rapidly under abnormal conditions, the high gas pressure impacts the explosion-proof sheet. When the impact force reaches a certain value, the supporting frame inside the sheet body will buckle or become unstable. The buckled or unstable frame structure will form micro-gaps. When these micro-gaps connect, they form a pressure relief channel. This prevents the explosion-proof sheet from deforming without breaking, thus avoiding the risk of thermal runaway, combustion, or explosion.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery explosion-proof technology, and in particular to a lithium battery explosion-proof sheet triggered by high voltage differential. Background Technology

[0002] According to Chinese Patent Publication No. CN214227083U, an explosion-proof sheet for a lithium battery top cover is disclosed. The lithium battery top cover includes an outwardly protruding arc-shaped sheet and a flat sheet located on the bottom periphery of the arc-shaped sheet. At least one non-penetrating explosion-proof groove is provided on the periphery of the arc-shaped sheet. The thickness of the flat sheet is greater than the thickness of the arc-shaped sheet. A welding area is formed on the outer bottom of the flat sheet. The distance between the explosion-proof groove and the welding area is 2.5 mm. The welding has less than 0.01 MPa of impact on the explosion-proof sheet's burst pressure. The explosion-proof sheet welding has almost no impact on the burst pressure. The lithium battery top cover also includes an explosion-proof hole that matches the shape of the explosion-proof sheet. The explosion-proof sheet is fixedly fitted into the explosion-proof hole.

[0003] The aforementioned comparative documents and existing technologies have the following technical problems: under abnormal conditions, existing lithium batteries will cause the internal gas to increase rapidly. If the pressure cannot be released in time, there will be risks of thermal runaway, combustion or explosion. The explosion-proof sheet must be opened quickly when the internal pressure of the battery exceeds the set threshold to ensure battery safety. However, the explosion-proof sheet may undergo permanent deformation but not yet rupture. At this time, there will be risks such as internal gas accumulation that cannot be released and may lead to an explosion. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-voltage differential triggering lithium battery explosion-proof sheet.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a high-voltage differential triggered lithium battery explosion-proof sheet, comprising a sheet body, an arc-shaped top cover on the top of the sheet body, a serrated line on the outer side of the arc-shaped top cover, and a fixing ring on the outer side of the top of the sheet body.

[0006] Preferably, a membrane is provided at the bottom end of the sheet, and the membrane is embedded at the bottom end of the sheet.

[0007] Preferably, the bottom end of the sheet is provided with a cavity, and a supporting skeleton is provided inside the cavity.

[0008] Preferably, the support frame is shaped like a cone, and the two sides of the support frame are connected to the inner wall of the cavity, and the top of the outer periphery of the support frame is connected to the etched line.

[0009] Preferably, the bottom of the inner part of the sheet is provided with a bottom plate, and the bottom of the bottom plate is provided with a spiral hole.

[0010] Preferably, the spiral hole has a tapered thread shape, with the outer side of the spiral hole being the cone apex and the inner side being the cone trough.

[0011] Preferably, the spiral hole penetrates through the bottom plate into the cavity, and the spiral hole is located on the side of the supporting frame.

[0012] Beneficial effects

[0013] In this invention, a support frame is used. When the lithium battery is in an abnormal situation, the internal gas will increase rapidly. The high gas pressure will impact the explosion-proof sheet. When the impact force reaches a certain value, the support frame inside the sheet will buckle or become unstable. The buckled or unstable frame structure will form micro gaps. When the micro gaps connect, they form a pressure relief channel. This will prevent the explosion-proof sheet from deforming but not breaking, which could lead to thermal runaway, combustion, or explosion.

[0014] In this invention, a spiral hole and a cavity are used. When high-pressure air impacts the explosion-proof sheet, if the internal support frame does not fully buckle, the air pressure will continue to impact the diaphragm, causing it to rupture. After rupture, the air pressure will enter the cavity of the support frame through the spiral hole. Within the cavity, the pressure will rapidly accumulate through the fluid throttling effect and form a local pressure pulse, which will impact the support frame and the arc-shaped top cover, causing the support frame to buckle and the arc-shaped top cover to develop micro-cracks in the scoring lines, thus releasing pressure. This provides a double protection against pressure evacuation. Attached Figure Description

[0015] Figure 1 This is an isometric view of the present invention;

[0016] Figure 2 This is a side sectional view of the present invention;

[0017] Figure 3 This is an internal sectional view of the present invention;

[0018] Figure 4 This is a bottom sectional view of the present invention;

[0019] Figure 5 This is a schematic diagram of the support frame of this utility model;

[0020] Figure 6 This is a schematic diagram of the spiral hole of this utility model.

[0021] Legend:

[0022] 1. Sheet body; 2. Arc-shaped top cover; 3. Scoring line; 4. Fixing ring; 5. Diaphragm; 6. Support frame; 7. Cavity; 8. Base plate; 9. Spiral hole. Detailed Implementation

[0023] To make the technical means, creative features, and achieved objectives and effects of this utility model easier to understand, the present utility model is further described below with reference to specific embodiments and accompanying drawings. However, the following embodiments are merely preferred embodiments of this utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments described in the implementation plan without creative effort are all within the protection scope of this utility model.

[0024] The specific embodiments of this utility model are described below with reference to the accompanying drawings. Specific Implementation Example 1:

[0026] Reference Figure 1-6 This invention provides a high-voltage differential triggered lithium battery explosion-proof sheet, comprising a sheet body 1, an arc-shaped top cover 2 on the top of the sheet body 1, a groove line 3 on the outer side of the arc-shaped top cover 2, a fixing ring 4 on the outer side of the top of the sheet body 1, a diaphragm 5 at the bottom of the sheet body 1, the diaphragm 5 being embedded in the bottom of the sheet body 1, a cavity 7 at the bottom of the sheet body 1, and a support frame 6 inside the cavity 7. The support frame 6 is shaped like a cone, and its two sides are connected to the inner wall of the cavity 7. The outer top of the support frame 6 is connected to the groove line 3. When the lithium battery experiences an abnormal situation that causes a rapid increase in internal gas, the high gas pressure will impact the explosion-proof sheet. When the impact force reaches a certain value, the support frame 6 inside the sheet body 1 will buckle or become unstable. The buckled or unstable frame structure will form micro-gaps. When the micro-gaps connect, they form a pressure relief channel, thus preventing the explosion-proof sheet from deforming. To mitigate the risk of thermal runaway, combustion, or explosion without rupture, the inner bottom of the sheet 1 is equipped with a base plate 8. The bottom of the base plate 8 has a spiral hole 9. The spiral hole 9 has a conical thread shape, with the outer side of the spiral hole 9 forming the cone apex and the inner side forming the cone trough. The spiral hole 9 penetrates the base plate 8 into the cavity 7, and its position is located on the side of the support frame 6. By employing the spiral hole 9 and the cavity 7, when high-pressure impacts the explosion-proof sheet, if the internal support frame 6 does not fully buckle, the continued pressure will impact the diaphragm 5, causing it to rupture. After rupture, the pressure will enter the cavity 7 containing the support frame 6 through the spiral hole 9. Within the cavity, the pressure will rapidly accumulate through the fluid throttling effect, forming a localized pressure pulse that impacts the support frame 6 and the arc-shaped top cover 2, causing the support frame 6 to buckle and the arc-shaped top cover 2 to develop micro-cracks in the scoring line 3, thus releasing pressure. This provides a double layer of protection against pressure rupture. Specific Implementation Example 2:

[0028] Reference Figure 1An ultra-thin weak layer is attached to the outside or inside of the original explosion-proof sheet. When the main layer undergoes plastic deformation but does not crack, the secondary weak layer has already cracked, forming an initial incision sufficient to guide the main layer to continue cracking. A third layer of micropore array can be arranged below the weak layer to form multi-level triggering. The premature cracking of the weak layer will not affect the overall pressure bearing capacity of the main layer, and the crack is precisely controllable. It can realize three-level pressure relief from the main layer to the weak layer and then to the micropores, ensuring that it can be activated in time even if the main layer deforms.

[0029] In summary:

[0030] By adopting the support frame 6, when the internal gas of the lithium battery increases rapidly under abnormal conditions, the high gas will impact the explosion-proof sheet. When the impact force reaches a certain value, the support frame 6 inside the sheet 1 will buckle or become unstable. The buckled or unstable frame structure will form micro gaps. When the micro gaps connect, they form a pressure relief channel. This will prevent the explosion-proof sheet from deforming but not breaking, which could lead to thermal runaway, combustion, or explosion risks.

[0031] By employing a spiral hole 9 and a cavity 7, when high-pressure air impacts the explosion-proof sheet, if the internal support frame 6 does not fully buckle, the air pressure will continue to impact the diaphragm 5, causing it to rupture. After rupture, the air pressure will enter the cavity 7 containing the support frame 6 through the spiral hole 9. Within the cavity, the pressure will rapidly accumulate through the fluid throttling effect and form a local pressure pulse, impacting the support frame 6 and the arc-shaped top cover 2. This causes the support frame 6 to buckle, and the impact on the arc-shaped top cover 2 causes micro-cracks to appear in the scoring line 3, thus releasing pressure. This provides a double guarantee of pressure relief.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A high-voltage differential triggered lithium battery explosion venting disc comprising a disc body (1), characterized in that: The top of the sheet (1) is provided with an arc-shaped top cover (2), and the outer side of the arc-shaped top cover (2) is provided with a scribe line (3). The outer side of the top of the sheet (1) is provided with a fixing ring (4). The bottom end of the sheet (1) is provided with a cavity (7). The cavity (7) is provided with a support frame (6). The two sides of the support frame (6) are connected to the inner wall of the cavity (7). The top edge of the support frame (6) is connected to the scribe line (3).

2. The high-voltage differential triggered lithium battery explosion suppression sheet according to claim 1, characterized in that: The bottom end of the sheet (1) is provided with a diaphragm (5), which is embedded in the bottom end of the sheet (1).

3. The high-voltage differential triggering lithium battery explosion-proof sheet according to claim 1, characterized in that: The supporting skeleton (6) is shaped like a vertebra.

4. The high-voltage differential triggered lithium battery explosion suppression sheet according to claim 1, characterized in that: The bottom of the inner part of the sheet (1) is provided with a bottom plate (8), and the bottom of the bottom plate (8) is provided with a spiral hole (9).

5. The high-voltage differential triggered lithium battery explosion suppression sheet according to claim 4, characterized in that: The spiral hole (9) has a tapered thread shape, with the outer side of the spiral hole (9) being the cone apex and the inner side of the spiral hole (9) being the cone trough.

6. The high-voltage differential triggered lithium battery explosion suppression sheet according to claim 5, characterized in that: The spiral hole (9) penetrates the bottom plate (8) into the cavity (7).

7. The high-voltage differential triggered lithium battery explosion suppression sheet according to claim 5, characterized in that: The spiral hole (9) is located on the side of the support frame (6).

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