Explosion-proof battery case and cylindrical battery

Abstract

The utility model discloses an explosion-proof battery case and a cylindrical battery. The explosion-proof battery shell comprises a shell body, a boss and explosion-proof nicks, the shell body is provided with a hollow inner cavity, one end of the shell body is provided with an opening, and the other end of the shell body is closed; the boss is located at the closed end of the shell, and the protruding direction of the boss faces the open end of the shell; and the anti-explosion nicks are distributed around the boss. According to the anti-explosion valve, the boss and the anti-explosion nick form the anti-explosion valve, the structural design of the anti-explosion valve can be simplified, and the cost is effectively reduced; the anti-explosion valve is high in structural strength, the closed end of the shell serves as the bottom of the shell, so that the boss protrudes inwards and is hidden, and the situation that the anti-explosion valve is damaged and fails due to external force is avoided; meanwhile, the explosion-proof valve is arranged at the bottom of the battery cell, and when the battery cell fails, the pressure relief outlet faces downwards, so that direct impact on passengers is avoided, and the safety is improved.

Description

Technical Field

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

[0002] Almost all safety accidents caused by lithium batteries are caused by short circuits. When a lithium battery is short-circuited, a very large current and heat will be generated inside the battery. The heat and excessive electrical energy release will not only seriously damage the battery life, but also for lithium batteries made of sealed packages, a certain amount of pressure will be generated inside, resulting in a sudden increase in the internal pressure of the battery. And because the chemical properties of lithium ions are very active, the shell will eventually burst and burn.

[0003] Traditional explosion-proof battery shells and explosion-proof caps have complex structures, cannot effectively release pressure, and are prone to aging or deformation due to collision, affecting normal use and low safety. As shown in patents CN117810622A, CN117832706A and CN220984772U, in square aluminum shell batteries, the explosion-proof valve is generally set in the middle of the battery cover slightly below the horizontal position of the cover, and is integrated with the cover by welding. As shown in patents CN117497928A and CN117895154A, in cylindrical batteries, the explosion-proof valve is generally set at an eccentric position next to the top pole of the battery, and is integrated with the cover by welding. As shown in patents CN117810517A and CN117832707A, in single-out cylindrical batteries, there is also an explosion-proof valve set at an eccentric position at the bottom of the battery shell, and is integrated with the shell by welding. The above-mentioned explosion-proof valve has one or more of the following disadvantages: 1. The structural design is complex and requires additional welding to be integrated with the cover plate / housing, which increases the cost; 2. The structural strength of the explosion-proof valve itself is low and it is easily damaged and ineffective due to external forces; 3. After the battery cell PACK is integrated into a battery pack, it is placed horizontally on the bottom of the vehicle. At this time, the openings of the explosion-proof valves are all facing upwards. After thermal runaway occurs, the ejected material will directly face the passengers, posing a safety hazard.

[0004] In summary, the existing explosion-proof valves and batteries have technical problems of complex structure, low strength and poor safety. Utility Model Content

[0005] The purpose of this application is to overcome the above-mentioned technical deficiencies, propose an explosion-proof battery case and a cylindrical battery, and solve the technical problems of complex structure, low strength and poor safety in the prior art.

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the present application provides an explosion-proof battery case, comprising a case body, a boss and explosion-proof indentations:

[0008] The case body has a hollow inner cavity, one end of the case body has an opening, and the other end is closed;

[0009] The boss is located at the closed end of the case body, and the protruding direction of the boss faces the opening end of the case body; and

[0010] The explosion-proof indentations are distributed around the boss.

[0011] In some embodiments of the present application, the contour of the case body is cylindrical, and the orthographic projection of the boss on the closed end of the case body covers the center of the circle of the closed end of the case body.

[0012] In some embodiments of the present application, the boss is connected to the case body through a connection part, and the thickness of the connection part is less than the thickness of the boss and also less than the thickness of the closed end of the case body.

[0013] In some embodiments of the present application, the explosion-proof indentations are formed on the connection part and are located on the inner side, outer side or both inner and outer sides of the connection part facing the inside of the case body.

[0014] In some embodiments of the present application, it further comprises an auxiliary boss and auxiliary explosion-proof indentations. The auxiliary boss is located at the opening end or the side wall of the case body, and the protruding direction of the auxiliary boss faces the inside of the case body. The auxiliary explosion-proof indentations are distributed around the auxiliary boss.

[0015] In some embodiments of the present application, the cross-sectional contour of the boss includes a circle, and the cross-sectional contour of the explosion-proof indentations includes a circle.

[0016] In some embodiments of the present application, the cross-sectional contour of the boss includes a polygon, and the cross-sectional contour of the explosion-proof indentations includes a polygon.

[0017] In a second aspect, the present application further provides a cylindrical battery, comprising an electric core and the explosion-proof battery case according to any one of the embodiments in the first aspect. The electric core is filled in the inner cavity of the explosion-proof battery case.

[0018] In some embodiments of the present application, it further comprises a negative electrode case cover. The negative electrode case cover is connected to the explosion-proof battery case and covers the opening end of the explosion-proof battery case.

[0019] In some embodiments of the present application, the thickness of the connection part in the explosion-proof battery case is 0.1 mm - 2 mm, the height of the boss is 1 mm - 5 mm, and the opening pressure of the cylindrical battery is 0.5 Mpa - 6 Mpa.

[0020] Compared with the prior art, the technical solution provided by this application has the following beneficial technical effects:

[0021] The embodiment of the present application forms an explosion-proof valve by a boss and an explosion-proof notch, which can simplify the structural design of the explosion-proof valve and effectively reduce costs; the explosion-proof valve itself has high structural strength, and by using the closed end of the shell as the bottom of the shell, the boss is raised inward, which is relatively hidden, avoiding the explosion-proof valve from being broken and failing due to external forces; at the same time, the explosion-proof valve is arranged at the bottom of the battery cell. When the battery cell fails, the pressure relief outlet faces downward to avoid direct impact on passengers, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution in this application, the following is a brief introduction to the drawings required for use in the embodiments:

[0023] Figure 1 It is a schematic structural diagram of an explosion-proof battery case provided in an embodiment of the present application;

[0024] Figure 2 It is a partial enlarged view of an explosion-proof battery case provided in an embodiment of the present application;

[0025] Figure 3 is a cross-sectional view of an explosion-proof battery case provided in an embodiment of the present application;

[0026] Figure 4 It is an enlarged cross-sectional view of an explosion-proof battery shell provided in an embodiment of the present application.

[0027] Reference numerals:

[0028] Shell 1, closed end 11, open end 12, boss 2, explosion-proof notch 3, connection 4. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] Those skilled in the art will appreciate that in this specification, the wording "including" is an open-ended expression, which means that the described features exist but does not exclude other features. The directional words "up", "down", "left", "right", etc. are exemplary directions based on the drawings. Features defined as "first" and "second" implicitly include one or more of the features. Singular expressions can also be used in the plural. "Multiple" means two or more. The terms "installed", "connected", and "connected" can be fixed connections, detachable connections, or integrated connections; they can be directly connected, or indirectly connected through an intermediate medium, or they can be internal connections between two elements. In addition, "connected" can include wireless connections.

[0031] The purpose of this application is to overcome the above-mentioned technical deficiencies, propose an explosion-proof battery case and a cylindrical battery, and solve the technical problems of complex structure, low strength and poor safety in the prior art.

[0032] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0033] In a first aspect, the present application provides an explosion-proof battery case, such as Figure 1 and Figure 2 As shown, Figure 1 It is a schematic structural diagram of an explosion-proof battery case provided in an embodiment of the present application; Figure 2 It is a partial enlarged view of an explosion-proof battery case provided in an embodiment of the present application.

[0034] An explosion-proof battery case, comprising a shell 1, a boss 2 and an explosion-proof notch 3:

[0035] A shell 1, wherein the shell 1 has a hollow inner cavity, one end of the shell 1 has an opening, and the other end is closed;

[0036] a boss 2, wherein the boss 2 is located at the closed end 11 of the housing 1, and the protruding direction of the boss 2 is toward the open end 12 of the housing 1; and

[0037] The explosion-proof notches 3 are distributed around the boss 2 .

[0038] The embodiment of the present application forms an explosion-proof valve by forming a boss 2 and an explosion-proof notch 3, which can simplify the structural design of the explosion-proof valve and effectively reduce costs; the explosion-proof valve itself has high structural strength, and by using the closed end 11 of the shell 1 as the bottom of the shell 1, the boss 2 is raised inward, which is relatively hidden, avoiding the explosion-proof valve from being damaged and failing due to external forces; at the same time, the explosion-proof valve is arranged at the bottom of the battery cell. When the battery cell fails, the pressure relief outlet faces downward to avoid direct impact on passengers, thereby improving safety.

[0039] In some embodiments of the present application, the contour of the housing 1 is cylindrical, and the orthographic projection of the boss 2 on the closed end 11 of the housing 1 covers the center of the closed end 11 of the housing 1.

[0040] In this embodiment, the boss 2 is disposed at the center of the bottom of the housing 1. The boss 2 / raised portion at the bottom center is formed by stamping. The boss 2 protrudes toward the open end 12, so that the metal at the connection 4 between the bottom of the housing 1 and the boss is stretched.

[0041] The design of the cylindrical housing 1 provides a uniform and stable structure that can withstand the pressure generated by the internal battery components and the influence of the external environment. The boss covers the center of the closed end 11 of the housing 1, ensuring the symmetry of the structure of the housing 1. This symmetry helps to improve the rigidity and torsional resistance of the housing 1.

[0042] As Figure 3 and Figure 4 shown, Figure 3 is a cross-sectional view of an explosion-proof battery housing provided by an embodiment of the present application; Figure 4 is an enlarged cross-sectional view of an explosion-proof battery housing provided by an embodiment of the present application. It is worth mentioning that by inverting the directions of the explosion-proof battery housings in Figure 1 and Figure 2 , the directions of the explosion-proof battery housings in Figure 3 and Figure 4 are obtained.

[0043] In some embodiments of the present application, the boss 2 is connected to the housing 1 through the connection 4. The thickness of the connection 4 is less than the thickness of the boss 2 and also less than the thickness of the closed end 11 of the housing 1.

[0044] In this embodiment, the connection position between the bottom of the housing 1 and the boss 2 is stretched, resulting in the mechanical strength of the connection 4 being lower than that of other positions of the housing 1, and having a certain explosion-proof valve function. When the internal pressure of the battery cell is too high, the valve will open first here.

[0045] The height of the boss (the height from the top plane of the boss to the bottom plane of the housing 1) will directly affect the stretching length, and thus affect the mechanical strength of the metal at the stretched portion.

[0046] In some embodiments of the present application, the explosion-proof notch 3 is opened on the connection 4 and is located on the inner side, outer side or both inner sides of the connection 4 facing the housing 1.

[0047] In this embodiment, at the stretching position, anti-explosion valve indentations are set by means of laser etching, rolling, thinning, extrusion, etc. The anti-explosion valve indentations are circular or arc-shaped groove structures. The combination of the two can further realize the function of the anti-explosion valve for the entire boss. When the battery cell undergoes thermal runaway, the anti-explosion valve will open the valve at a position other than the housing 1 first, and then release pressure to release the internal gas and pressure.

[0048] The design of the anti-explosion indentation 3 can add a pressure release channel at the connection 4, improving the safety and reliability of the battery; compared with opening an additional anti-explosion valve on the housing 1, by opening the anti-explosion indentation 3 at the connection 4, the structure of the battery can be optimized, the demand for the anti-explosion valve can be reduced, materials can be saved, and the production cost can be lowered.

[0049] In some embodiments of the present application, it further includes an auxiliary boss and an auxiliary anti-explosion indentation. The auxiliary boss is located at the open end 12 or the side wall of the housing 1, and the protruding direction of the auxiliary boss faces the inner side of the housing 1. The auxiliary anti-explosion indentation is distributed around the auxiliary boss.

[0050] In this embodiment, an auxiliary boss can also be provided at the top or side of the housing 1, and a circle of auxiliary anti-explosion indentations is also provided at the connection part (stretching position) between the auxiliary boss and the housing 1.

[0051] When the auxiliary boss is provided at the top of the housing 1, the top of the housing 1 can be partially open and partially closed. The auxiliary boss is provided at the partially closed part, or can be provided on the structure covering the open end 12.

[0052] The design of the auxiliary anti-explosion indentation can form a pressure release channel around the auxiliary boss. When the internal pressure of the battery rises rapidly, the auxiliary anti-explosion indentation can open the valve to help the main channel release the internal pressure, further improving the safety and reliability.

[0053] In some embodiments of the present application, the cross-sectional profile of the boss 2 includes a circle, and the cross-sectional profile of the anti-explosion indentation 3 includes a circle.

[0054] In some embodiments of the present application, the cross-sectional profile of the boss 2 includes a polygon, and the cross-sectional profile of the anti-explosion indentation 3 includes a polygon.

[0055] In a second aspect, the present application further provides a cylindrical battery, including a battery cell and an anti-explosion battery housing as described in any one of the embodiments in the first aspect. The battery cell is filled in the inner cavity of the anti-explosion battery housing.

[0056] In some embodiments of the present application, it further includes a negative electrode shell cover. The negative electrode shell cover is connected to the anti-explosion battery housing and covers the open end 12 of the anti-explosion battery housing.

[0057] In this embodiment, the interior of the housing 1 is a cavity, and the top is provided with an opening. The top is connected to the negative electrode housing cover by peripheral welding, and the cylindrical size can be freely adjusted.

[0058] In some embodiments of the present application, the thickness of the connection part 4 in the explosion-proof battery housing is 0.1 mm - 2 mm, the height of the boss 2 is 1 mm - 5 mm, and the opening pressure of the cylindrical battery is 0.5 Mpa - 6 Mpa.

[0059] In this embodiment, by adjusting the notch depth, that is, the thickness of the connection part 4 and the height of the boss, different opening pressures can be achieved. This explosion-proof valve design can appropriately adjust the height of the boss and the thickness at the notch according to the internal space height of the housing 1 and the specific opening pressure requirements, so as to flexibly adapt to different battery cores.

[0060] When the thickness of the connection part 4 ranges from 0.1 mm to 2 mm and the height of the boss is from 1 mm to 5 mm, the corresponding opening pressure of the cylindrical battery core is 0.5 Mpa to 6 Mpa. The actual situation can be adjusted accordingly according to the thickness of the battery core housing 1.

[0061] Compared with the prior art, the beneficial technical effects brought by the technical solution provided in the present application include:

[0062] In the embodiment of the present application, the explosion-proof valve is composed of the boss 2 and the explosion-proof notch 3, which can simplify the structural design of the explosion-proof valve and effectively reduce the cost; the explosion-proof valve itself has high structural strength. By using the closed end 11 of the housing 1 as the bottom of the housing 1, the explosion-proof valve structure can also be located at the bottom of the housing 1, which is relatively concealed and can avoid the explosion-proof valve being damaged and ineffective due to external forces; at the same time, the explosion-proof valve is arranged at the bottom of the battery core. When the battery core fails, the pressure relief outlet faces downward, avoiding direct impact on passengers and improving safety.

[0063] Compared with the scheme where the boss 2 protrudes outward, the explosion-proof notch 3 is exposed on the outside and is easily damaged by external forces such as bumps, collisions, and abrasions. In this embodiment, the boss 2 protrudes inward, and the explosion-proof notch 3 is not easily damaged by external forces (main function); the inward protrusion of the boss 2 can be in close contact with the internal wound core, improving the laser welding effect between the battery core and the housing (auxiliary function); when the battery cores are integrated into a module, the battery cores need to be placed vertically, and it is necessary to ensure that the bottom of the battery cores is a flat surface. Therefore, generally, the boss 2 needs to protrude inward (auxiliary function).

[0064] Those skilled in the art of the present technology can understand that the various operations, methods, steps, measures, and solutions in the processes discussed in the present application can be alternated, changed, rearranged, decomposed, combined, or deleted.

[0065] The specific embodiments of the present application described above do not limit the protection scope of the present application. Any other corresponding changes and deformations made according to the technical concept of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. An explosion-proof battery case, characterized in that: include: A shell, wherein the shell has a hollow inner cavity, one end of the shell has an opening, and the other end of the shell is closed; a boss, the boss being located at the closed end of the shell, and the protruding direction of the boss being toward the open end of the shell; and Explosion-proof notches are distributed around the boss.

2. An explosion-proof battery case according to claim 1, characterized in that: The shell has a cylindrical profile, and the orthographic projection of the boss on the closed end of the shell covers the center of the closed end of the shell.

3. An explosion-proof battery case according to claim 1, characterized in that: The boss is connected to the shell through a connection, and the thickness of the connection is smaller than the thickness of the boss and also smaller than the thickness of the closed end of the shell.

4. An explosion-proof battery case according to claim 3, characterized in that: The explosion-proof notch is opened on the connection and is located at the connection toward the inside, outside or both sides of the inside of the shell.

5. An explosion-proof battery case according to claim 1, characterized in that: It also includes an auxiliary boss and an auxiliary explosion-proof notch, wherein the auxiliary boss is located at the opening end or the side wall of the shell, and the protruding direction of the auxiliary boss faces the inner side of the shell, and the auxiliary explosion-proof notch is distributed around the auxiliary boss.

6. An explosion-proof battery case according to claim 1, characterized in that: The cross-sectional profile of the boss includes a circle, and the cross-sectional profile of the explosion-proof notch includes a circle.

7. An explosion-proof battery case according to claim 1, characterized in that: The cross-sectional profile of the boss includes a polygon, and the cross-sectional profile of the explosion-proof notch includes a polygon.

8. A cylindrical battery, characterized in that: It comprises a battery cell and an explosion-proof battery shell as described in any one of claims 1 to 7, wherein the battery cell is filled in the inner cavity of the explosion-proof battery shell.

9. A cylindrical battery according to claim 8, characterized in that: The invention also includes a negative electrode case cover, which is connected to the explosion-proof battery case and covers the open end of the explosion-proof battery case.

10. A cylindrical battery according to claim 8, characterized in that: The thickness of the connection in the explosion-proof battery shell is 0.1mm-2mm, the height of the boss is 1mm-5mm, and the valve opening pressure of the cylindrical battery is 0.5Mpa-6Mpa.

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