Pressure relief structure of cylindrical battery and cylindrical battery

Abstract

The utility model belongs to the technical field of cylindrical batteries, and provides a pressure relief structure of a cylindrical battery and the cylindrical battery, and the pressure relief structure comprises a first nick which is arranged on an end cover of the cylindrical battery and is of a C-shaped structure; the second nick is arranged on an end cover of the cylindrical battery, is of an arc-shaped structure and is connected with the first nick end to end to form a whole circle; wherein the depth of the first nick is greater than that of the second nick, so that when the part of the end cover surrounded by the whole circle is broken along the first nick, the part of the end cover can turn over around the second nick to realize pressure relief in the cylindrical battery. According to the utility model, the first nick and the second nick which are different in depth are connected into a whole circle, so that the cylindrical battery can break through the first nick and turn over around the second nick to be not thoroughly broken during pressure relief, the deformation sensitivity during pressure relief is improved, the explosion risk is avoided, fragments generated during pressure relief can be prevented from flying out to cause secondary risk, and the service life of the cylindrical battery is prolonged. And the safety of the battery in the using process is ensured.

Description

Technical Field

[0001] This utility model relates to the field of cylindrical battery technology, specifically to a pressure relief structure for a cylindrical battery and a cylindrical battery. Background Technology

[0002] Lithium-ion / sodium-ion cylindrical batteries have gradually become the mainstream product in the new energy industry due to their advantages such as high energy density, good capacity consistency, and ability to support high-rate charge and discharge. More and more manufacturers are continuously improving the energy density of cylindrical batteries while also pursuing high safety.

[0003] Currently, to ensure the safety of cylindrical batteries, a pressure relief structure is usually installed on the end cap of the cylindrical battery. This allows the airflow inside the cylindrical battery to be released by breaking through the pressure relief structure when the internal pressure exceeds a threshold, thus preventing the cylindrical battery from exploding.

[0004] However, the pressure relief structure of current cylindrical batteries is usually a simple groove, and this grooved pressure relief valve structure has the following problems:

[0005] 1. Cylindrical batteries are long and thin, and the grooves on their end caps are small. This makes it difficult for cylindrical batteries to break through the grooves in time to release pressure and vent gas during short circuit or high temperature storage tests, which can easily lead to explosions and pose a safety risk to customers.

[0006] 2. The casing of cylindrical batteries is generally made of steel. The grooves are usually set at the thicker bottom of the casing. When there is an abnormality or increased internal pressure, the cylindrical battery is not easily deformed. Moreover, due to the hardness of the steel casing, the breaking pressure of the grooves is generally high, and the deformation sensitivity is low.

[0007] 3. To avoid secondary risks caused by fragments flying out after the scratches break through, a scratch-free area with a certain central angle is usually set between the beginning and end of the scratches. The steel shell material in this area is thicker, which further reduces the sensitivity of the scratches to deformation, resulting in safety hazards in the use of cylindrical batteries. Utility Model Content

[0008] To address the shortcomings of existing technologies, this utility model provides a pressure relief structure for a cylindrical battery and a cylindrical battery, thereby solving the problems that existing linear grooved pressure relief structures cannot be broken by airflow in time and have low deformation sensitivity.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A pressure relief structure for a cylindrical battery, comprising:

[0011] The first notch, located on the end cap of the cylindrical battery, is C-shaped; and

[0012] The second notch is located on the end cap of the cylindrical battery. It has an arc-shaped structure and is connected end to end with the first notch to form a complete circle.

[0013] The depth of the first notch is greater than the depth of the second notch, so that when the end cap enclosed by the whole circle breaks along the first notch, it can be flipped around the second notch to release pressure inside the cylindrical battery.

[0014] In one embodiment disclosed in this application, the end cap has a circular pressure relief area in the middle;

[0015] The first and second notches are concentric and of equal radius in the pressure relief area.

[0016] In one embodiment disclosed in this application, the cross-section of the first notch has a V-shaped structure with a narrower bottom;

[0017] The second notch has a U-shaped cross-section with a wider bottom.

[0018] In one embodiment disclosed in this application, the first and second notches are integrally stamped or cold-extruded to form a stepped structure at both ends of the first notch.

[0019] In one embodiment disclosed in this application, the thickness of the retained portion of the first notch corresponding to the pressure relief area is 0.02–0.08 mm;

[0020] The thickness of the retained portion of the second notch corresponding to the pressure relief area is 0.2 to 0.8 mm.

[0021] In one embodiment disclosed in this application, the central angle corresponding to the second notch is 10 to 35°.

[0022] In one embodiment disclosed in this application, the end cap is located at the bottom of the cylindrical battery and is connected to the casing of the cylindrical battery by integral molding or welding.

[0023] In one embodiment disclosed in this application, the end cap and the shell are made of steel or aluminum.

[0024] A cylindrical battery comprising the pressure relief structure described in any one of the above.

[0025] Compared with the prior art, the beneficial effects of this utility model are:

[0026] 1. By connecting the first and second scribes of different depths to form a complete circle, the cylindrical battery can break through the first scribe and rotate around the second scribe without completely breaking when the pressure is released. This improves the deformation sensitivity during pressure release, avoids the risk of explosion, and prevents secondary risks caused by flying fragments during pressure release, thus ensuring the safety of the battery during use.

[0027] 2. The central angle corresponding to the second notch is preferably 10 to 35°, which can ensure the deformation sensitivity of the end cap when the cylindrical battery is depressurized, and at the same time ensure that the reserved part of the corresponding depressurization area has sufficient length to ensure its toughness and avoid breakage during depressurization. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a three-dimensional structural diagram of the cylindrical battery in this utility model;

[0030] Figure 2 This is a schematic diagram of the main structure of the pressure relief structure in this utility model;

[0031] Figure 3 This is a cross-sectional view of the pressure relief structure in this utility model;

[0032] Figure 4 for Figure 3 A magnified schematic diagram of section A in the middle;

[0033] Figure 5 for Figure 3 A magnified schematic diagram of part B in the middle section. Detailed Implementation

[0034] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0035] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0038] 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.

[0039] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this invention.

[0040] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0041] See Figures 1-5 As shown, on one hand, this utility model provides a pressure relief structure for a cylindrical battery, including:

[0042] The first notch 11 is provided on the end cap 10 of the cylindrical battery, and it has a C-shaped structure; and

[0043] The second notch 12 is provided on the end cap 10 of the cylindrical battery. It has an arc-shaped structure and is connected end to end with the first notch 11 to form a complete circle.

[0044] The depth of the first notch 11 is greater than the depth of the second notch 12, so that when the end cap 10 enclosed by the whole circle breaks along the first notch 11, it can be flipped around the second notch 12 to achieve pressure relief inside the cylindrical battery.

[0045] Specifically, see Figure 3 As shown, the end cap 10 has a circular pressure relief area in the middle. The first notch 11 and the second notch 12 are concentric and of equal radius in this pressure relief area. The first notch 11 is deeper, making the reserved portion of its corresponding pressure relief area thinner and weaker; the second notch 12 is shallower, making the reserved portion of its corresponding pressure relief area thicker and stronger. Therefore, during the use of the cylindrical battery, when its internal pressure exceeds the threshold, the airflow inside the cylindrical battery will first break through the first notch 11, causing the pressure relief area (i.e., the part of the end cap 10 enclosed by the circle) to flip around the reserved portion at the second notch 12 to achieve pressure relief, thereby preventing the cylindrical battery from exploding. Due to the pressure relief, the internal pressure of the cylindrical battery decreases, and the reserved portion at the second notch 12 will not break but remain connected, thus effectively preventing the flipped pressure relief area from flying out and causing secondary risks. In other words, by connecting the first scribbles 11 and the second scribbles 12 of different depths to form a complete circle, the cylindrical battery can break through the first scribbles 11 and rotate around the second scribbles 12 without completely breaking when the pressure is released. This improves the deformation sensitivity during pressure release, avoids the risk of explosion, and prevents the secondary risks caused by the flying fragments generated during pressure release, thus ensuring the safety of the battery during use.

[0046] See Figure 4 and Figure 5 As shown, the cross-section of the first notch 11 is V-shaped with a narrower bottom; the cross-section of the second notch 12 is U-shaped with a wider bottom.

[0047] The first notch 11 and the second notch 12 are integrally stamped or cold-extruded to form a stepped structure at both ends of the first notch 11. Specifically, on a sheet material with a total thickness of T for the end cap 10, the stamping or cold-extruded depth of the first notch 11 is h1 through fine-tuning, and the thickness of the retained portion of the corresponding pressure relief area is T1; the stamping or cold-extruded depth of the second notch 12 is h2 through fine-tuning (appropriately reducing the processing amount), and the thickness of the retained portion of the corresponding pressure relief area is T2. In this embodiment, T1 is preferably in the range of 0.02 to 0.08 mm, and T2 is preferably in the range of 0.2 to 0.8 mm.

[0048] See Figure 2 As shown, the central angle α corresponding to the second notch 12 is preferably 10 to 35°. This ensures the deformation sensitivity of the end cap 10 when the cylindrical battery is depressurized, while also ensuring that the retained portion of the corresponding depressurization area has sufficient length to guarantee its toughness and prevent breakage during depressurization.

[0049] The end cap 10 is located at the bottom of the cylindrical battery and is connected to the cylindrical battery casing 20 by integral molding or welding.

[0050] In this embodiment, the end cap 10 and the shell 20 are made of steel or aluminum.

[0051] On the other hand, this utility model provides a cylindrical battery, including the pressure relief structure described above.

[0052] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the technical solutions of this utility model. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of this utility model patent.

Claims

1. A pressure relief structure of a cylindrical battery, characterized by comprising: The cylindrical battery comprises: a first notch in the shape of a C on the end cover of the cylindrical battery; and a second notch in the shape of an arc on the end cover of the cylindrical battery, which is connected to the first notch to form a complete circle. The depth of the first notch is greater than that of the second notch, so that when the part of the end cover enclosed by the complete circle breaks along the first notch, it can be flipped around the second notch to achieve pressure relief inside the cylindrical battery.

2. The pressure relief structure of the cylindrical battery according to claim 1, wherein: the middle part of the end cover has a circular pressure relief area; the first notch and the second notch are arranged in the same radius and concentrically in the pressure relief area.

3. The pressure relief structure of the cylindrical battery according to claim 2, wherein: the cross section of the first notch is in the shape of a V, with a narrow bottom; the cross section of the second notch is in the shape of a U, with a wide bottom. The first notch and the second notch are integrally punched or cold extruded to form a stepped structure at the two ends of the first notch.

4. The pressure relief structure for a cylindrical battery according to any one of claims 1 to 3, characterized in that 5. The pressure relief structure of the cylindrical battery according to claim 2 or 3, wherein: the thickness of the remaining part of the first notch corresponding to the pressure relief area is 0.02-0.08 mm; the thickness of the remaining part of the second notch corresponding to the pressure relief area is 0.2-0.8 mm. The central angle of the second notch is 10-35°.

6. The pressure relief structure of a cylindrical battery according to claim 5, wherein The end cover is located at the bottom of the cylindrical battery and is connected to the shell of the cylindrical battery in an integrally formed or welded manner.

7. The pressure relief structure of a cylindrical battery according to claim 1 or 6, wherein The material of the end cover and the shell is steel or aluminum. 8.The pressure relief structure of a cylindrical battery according to claim 7, wherein, The cylindrical battery comprises the pressure relief structure according to any one of claims 1-8.

9. A cylindrical battery, characterized by ​

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