Double-explosion-proof cylindrical battery

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a double-explosion-proof cylindrical battery. In order to solve the technical problem of explosion caused by the fact that only one end of a cylindrical battery in the prior art is provided with an explosion-proof valve, the utility model provides the double-explosion-proof cylindrical battery which is characterized in that a first explosion-proof valve is arranged on a battery top cover, and a second explosion-proof valve is arranged on a battery bottom cover; the center of the second anti-explosion valve and the center of the battery cell are coaxially arranged, and the second anti-explosion valve is of a closed or non-closed structure or a combination thereof. The double-explosion-proof cylindrical battery disclosed by the utility model has the beneficial effects that when the battery is in thermal runaway, stepped pressure relief and explosion prevention are realized, the exhaust speed is effectively ensured, and the battery explosion is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, in particular to a double explosion-proof cylindrical battery. Background Art

[0002] Lithium-ion cylindrical batteries can cause thermal runaway of the cells due to various reasons such as overcharging, overdischarging or high temperature. During thermal runaway, a large amount of gas will be generated inside the battery in a short period of time. If it cannot be discharged in time, it is easy to cause the battery to explode. Existing cylindrical batteries generally only have an explosion-proof valve installed at one end for pressure relief and explosion prevention. However, when the gas pressure inside the battery exceeds the pressure relief range of the explosion-proof valve instantly, only one end is used for pressure relief, and the internal pressure of the battery is still very high, which can easily lead to explosion. In addition, when the battery explosion-proof valve is used for exhaust and pressure relief, the internal gas will push the cells inside to move, which can easily block the pressure relief port. The gas cannot be discharged in time, which may also cause the battery to explode, posing a greater safety hazard. Utility Model Content

[0003] The utility model aims to provide a double explosion-proof cylindrical battery to solve the technical problem of explosion caused by poor pressure release due to the fact that only one end of the cylindrical battery in the prior art is provided with an explosion-proof valve.

[0004] To achieve the above purpose, the technical solution of the double explosion-proof cylindrical battery provided by the utility model is:

[0005] A double explosion-proof cylindrical battery comprises a shell, wherein the two axial ends of the shell are a battery top cover and a battery bottom cover respectively, a battery cell is contained inside the shell, a first explosion-proof valve is arranged on the battery top cover, a second explosion-proof valve is arranged on the battery bottom cover, the center of the second explosion-proof valve is coaxially arranged with the center of the battery cell, and the second explosion-proof valve is a closed or non-closed structure or a combination thereof.

[0006] Furthermore, the second explosion-proof valve is integrally formed with the battery bottom cover or separately welded and connected thereto.

[0007] Furthermore, the second explosion-proof valve includes at least one explosion-proof notch around the center of the battery bottom cover.

[0008] Furthermore, the shape of the explosion-proof notch is a centrally symmetrical or axially symmetrical figure.

[0009] Furthermore, the explosion-proof notch has a shape of at least 1 / 2 circle.

[0010] Furthermore, the explosion-proof notch is in a polygonal shape.

[0011] Furthermore, the shape of the explosion-proof notch is a regular polygon.

[0012] Furthermore, the cross-sectional shape of the explosion-proof notch is trapezoidal or stepped.

[0013] The beneficial effects of the double-explosion-proof cylindrical battery of the present utility model are as follows:

[0014] 1. Explosion-proof valves are respectively provided on the battery top cover and the battery bottom cover, which can effectively ensure the exhaust speed during battery thermal runaway and prevent the battery from exploding.

[0015] 2. The center of the second explosion-proof valve on the battery bottom cover is coaxially arranged with the center of the battery cell, which can ensure that when the second explosion-proof valve is opened, the center hole of the battery cell corresponds to the second explosion-proof valve, preventing the second explosion-proof valve from being blocked, ensuring smooth gas flow inside the battery, and avoiding explosion caused by blockage.

[0016] 3. By designing the bursting pressure ranges of the first explosion-proof valve and the second explosion-proof valve, stepped pressure relief and explosion prevention are achieved during battery thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the double-explosion-proof cylindrical battery of the present utility model;

[0018] Figure 2 is an exploded view of the structure of the double-explosion-proof cylindrical battery of the present utility model;

[0019] Figure 3 is a bottom view of the battery bottom cover according to an embodiment of the present utility model;

[0020] Figure 4 is Figure 3 a view taken along the line A-A of

[0021] Figure 5 is a bottom view of the battery bottom cover according to an embodiment of the present utility model;

[0022] Figure 6 is Figure 5 a view taken along the line B-B of

[0023] Figure 7 is a bottom view of the battery bottom cover according to an embodiment of the present utility model;

[0024] Figure 8 is Figure 7 a view taken along the line C-C of

[0025] Figure 9 is Figure 4 a partial enlarged view at G in

[0026] Figure 10 is Figure 8 a partial enlarged view at H in

[0027] Figure 11 is a bottom view of the battery bottom cover according to another embodiment of the present utility model;

[0028] Figure 12Bottom view of the battery bottom cover according to another embodiment of the present utility model;

[0029] Figure 13 Bottom view of the battery bottom cover according to another embodiment of the present utility model.

[0030] Explanation of reference numerals:

[0031] 1. Housing; 2. Battery top cover; 3. Battery bottom cover; 4. Battery cell; 5. First explosion-proof valve; 6. Second explosion-proof valve; 601. Explosion-proof notch. Detailed implementation manners

[0032] To solve the problems in the background art, the core inventive concept of the present utility model is: the first explosion-proof valve and the second explosion-proof valve are respectively arranged at the upper and lower parts of the battery, which can effectively avoid the problem of unsmooth pressure relief. In actual use, the bursting thresholds of the explosion-proof valve and the explosion-proof notch can be respectively set to achieve staged pressure relief. The coaxial arrangement of the explosion-proof notch, the explosion-proof valve and the center of the battery cell can also ensure the smooth discharge of the gas inside the battery during pressure relief and avoid explosion caused by blockage.

[0033] The following further describes the present utility model in detail with reference to embodiments.

[0034] Specific embodiment of the double-explosion-proof cylindrical battery provided by the present utility model

[0035] Refer to Figures 1-13 As shown, a double-explosion-proof cylindrical battery includes a housing 1. The two axial ends of the housing 1 are respectively a battery top cover 2 and a battery bottom cover 3. A battery cell 4 is accommodated inside the housing 1. A first explosion-proof valve 5 is provided on the battery top cover 2, and a second explosion-proof valve 6 is provided on the battery bottom cover. The center of the second explosion-proof valve 6 is coaxially arranged with the center of the battery cell 4. The second explosion-proof valve 6 is a closed or non-closed structure or a combination thereof.

[0036] In a specific implementation, assume that the bursting pressure range of the first explosion-proof valve on the battery top cover is A, and the bursting pressure range of the second explosion-proof valve on the battery bottom cover is B. When there is a subset or intersection relationship between the ranges A and B, when the internal pressure of the battery is too high and pressure relief is required, the first explosion-proof valve bursts first, or the second explosion-proof valve bursts first, or they burst simultaneously for pressure relief; when there is no intersection between the ranges A and B, if the internal pressure of the battery first reaches the bursting pressure range A, the first explosion-proof valve bursts first for pressure relief. If the internal pressure of the battery continues to increase and reaches the bursting pressure range B, at this time, the second explosion-proof valve bursts for pressure relief to achieve a stepped explosion-proof effect; conversely, if the internal pressure of the battery first reaches the bursting pressure range B, the second explosion-proof valve bursts first for pressure relief. If the internal pressure of the battery continues to increase and reaches the bursting pressure range A, at this time, the first explosion-proof valve bursts for pressure relief to achieve a stepped explosion-proof effect.

[0037] In some embodiments, the second explosion-proof valve 6 is integrally formed by stamping with the battery bottom cover 2, or is made by grooving on the battery bottom cover, or the second explosion-proof valve is made of an aluminum sheet, and then a groove or hole is made on the battery bottom cover, and then the separate second explosion-proof valve is welded to the battery bottom cover.

[0038] In some embodiments, the second explosion-proof valve 6 includes at least one explosion-proof notch 601 around the center of the battery bottom cover. However, in other specific embodiments, such as Figures 3-12 shown, the explosion-proof notch 601 can be 1 or 2 or other numbers, and the position can be close to the center of the battery bottom cover, or can be set close to the outer edge of the battery bottom cover, or a combination of both.

[0039] In some embodiments, the shape of the explosion-proof notch 601 is a centrally symmetric or axisymmetric figure, such as a circle, a rectangle, a polygon, etc. Preferably, it is a circle in terms of processing simplicity, mainly to satisfy that the center of the second explosion-proof valve 6 is coaxial with the center of the battery cell 4. The action area of the second explosion-proof valve 6 should cover or partially cover the corresponding projection area of the center hole of the battery cell 4 on the battery bottom cover 2, so as to achieve the purpose of not blocking the center hole of the battery cell during pressure relief and exhaust, and achieving fast and smooth exhaust.

[0040] In some embodiments, such as Figure 11 and Figure 12 shown, the shape of the explosion-proof notch 601 is at least 1 / 2 of a circle. In specific applications, such as Figure 11 or Figure 12 shown, the explosion-proof notch 601 can be set as 3 / 4 of a circle, and the position is set close to the inner or outer circle of the battery bottom cover 3. This structure can, when the battery is under pressure relief, cause the explosion-proof notch 601 to rupture and push out an opening on the battery bottom cover along its shape, realizing pressure relief and exhaust. This structure realizes the limitation of the exhaust direction, meets specific module designs, such as realizing uniform outward exhaust on a double-row battery module without affecting other batteries.

[0041] In some embodiments, the cross-section of the explosion-proof notch can be triangular, rectangular or other shapes. In specific applications, such as Figure 9 shown, the cross-sectional shape of the explosion-proof notch 601 is trapezoidal; or as Figure 10 shown, the cross-sectional shape of the explosion-proof notch 601 is stepped.

[0042] In some embodiments, the shape of the explosion-proof notch is a polygon, such as Figure 13 shown. In practical applications, it is preferably a regular polygon, which is convenient for production and processing.

[0043] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still make modifications to the technical solutions recorded in the foregoing embodiments without creative efforts, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A double-explosion-proof cylindrical battery, characterized in that: It includes a housing, with a battery top cover and a battery bottom cover at the two axial ends of the housing respectively. The housing accommodates battery cells inside. A first explosion-proof valve is provided on the battery top cover, and a second explosion-proof valve is provided on the battery bottom cover. The center of the second explosion-proof valve is coaxially arranged with the center of the battery cell. The second explosion-proof valve is of a closed or non-closed structure or a combination thereof.

2. The double-explosion-proof cylindrical battery according to claim 1, wherein: The second explosion-proof valve is integrally formed with the battery bottom cover or is connected by split welding.

3. The double-explosion-proof cylindrical battery according to claim 1 or 2, characterized in that: The second explosion-proof valve includes at least one explosion-proof notch around the center of the battery bottom cover.

4. The double-explosion-proof cylindrical battery according to claim 3, wherein: The shape of the explosion-proof notch is a centrally symmetric or axially symmetric figure.

5. The double-explosion-proof cylindrical battery according to claim 3, wherein: The shape of the explosion-proof notch is at least half a circle.

6. The double-explosion-proof cylindrical battery according to claim 3, characterized in that: The shape of the explosion-proof notch is a polygon.

7. The double-explosion-proof cylindrical battery according to claim 6, characterized in that: The shape of the explosion-proof notch is a regular polygon.

8. The double-explosion-proof cylindrical battery according to claim 3, wherein: The cross-sectional shape of the explosion-proof notch is trapezoidal or stepped.

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