Shell with reinforcing structure, cylindrical battery and battery pack

Abstract

The utility model relates to a shell with a reinforcing structure, a cylindrical battery and a battery pack. The shell with the reinforcing structure is applied to the cylindrical battery and comprises an end wall and a side wall surrounding the peripheral side of the end wall, the end wall is provided with a pole hole for mounting a pole, one end of the pole is a pole flange and is arranged on the outer side of the end wall, a sealing ring is arranged between the pole flange and the outer surface of the end wall, and the other end of the pole is a pole flange and is arranged on the inner side of the end wall. The terminal post flange and the terminal post flange clamp the end wall so as to fix the terminal post on the end wall, and the shell comprises a reinforcing rib which is arranged on the surface of the end wall and is positioned above the terminal post flange. The reinforcing ribs can reinforce the end wall corresponding to the pole turnup, reduce the deformation of the shell in the pole turnup area, further reduce the bending force of the end wall to the pole turnup, and prevent the pole from flying out due to thermal deformation. Meanwhile, the sealing ring and the pole flange are structurally adjusted according to the reinforcing ribs and are correspondingly nested, so that the deformation of the end wall corresponding to the pole flange can be further weakened.

Description

Technical Field

[0001] This utility model relates to the field of power batteries, specifically to a casing with a reinforced structure, a cylindrical battery, and a battery pack. Background Technology

[0002] Currently, most power batteries are lithium-ion batteries. During storage, charging, and discharging, lithium batteries undergo various electrochemical and thermodynamic reactions. In extreme situations, lithium batteries are prone to thermal runaway, experiencing instantaneous short circuits and releasing large amounts of heat. This causes a rapid rise in battery temperature, potentially leading to dangerous incidents such as car smoke or spontaneous combustion. Cell-level safety testing typically simulates this extreme phenomenon using a needle penetration test. When a needle penetrates the cell casing and a short circuit occurs, a large amount of gas is rapidly generated inside the cell, and the internal temperature rises rapidly. (Reference) Figure 1 The cylindrical battery has the following internal riveting structure for the terminal posts: 1. The terminal post flange 132 is parallel to the inner surface of the bottom of the casing; 2. The shoulder of the casing has a rounded transition; 3. The end wall 11 is mostly flat and has no reinforcing structure; 4. The mating interface of the sealing ring 14 is flat and has no reinforcing structure.

[0003] Under the above structure, when a cylindrical battery undergoes a nail penetration test, the bottom position of the casing with the terminals will change as follows: 1. Under the combined effects of heating and the rebound of the sealing ring, the terminal flange will rapidly open. When the diameter of the terminal's open end is smaller than the casing's aperture, the terminal will fly out. 2. When high-temperature gas pressure is generated inside the cell, it will cause warping deformation at the bottom of the casing. Since the casing strength is greater than the terminal flange strength, it will cause deformation of the end wall of the terminal flange area. That is, the terminal flange, which was originally parallel to the inner surface of the casing bottom, will warp and deform. When the diameter of the terminal's open end is smaller than the casing's aperture, the terminal will fly out. After the terminal flies out, the charged / conductive material burning inside the cell will fly further out from the terminal hole, leading to system-level thermal runaway. At the same time, because the terminal itself is conductive, after flying out, the terminal is likely to connect and conduct with the positive and negative electrodes of the system / other cells, leading to system-level thermal runaway.

[0004] Therefore, it is necessary to design a cylindrical battery to prevent the terminals from deforming and flying out due to thermal runaway. Summary of the Invention

[0005] To address the above problems, this utility model provides a casing with a reinforced structure, a cylindrical battery, and a battery pack.

[0006] This utility model discloses a housing with a reinforced structure, applied to a cylindrical battery, including an end wall and a side wall surrounding the end wall. The central area of ​​the end wall is provided with a terminal hole for mounting a terminal. One end of the terminal is a terminal flange located on the outer side of the end wall, and the other end is a terminal flange located on the inner side of the end wall. The terminal flange and the terminal flange clamp the end wall to fix the terminal to the end wall. The housing includes a reinforcing rib located on the surface of the end wall and above the terminal flange.

[0007] According to the above technical solution, the reinforcing ribs set above the flange of the terminal post can strengthen the end wall corresponding to the flange area of ​​the terminal post, reduce the shell deformation of the flange area of ​​the terminal post, and thus reduce the bending force of the end wall on the flange of the terminal post, preventing the terminal post from flying out due to thermal deformation when the cylindrical battery experiences thermal runaway.

[0008] Optionally, the reinforcing rib protrusion is provided on the outer surface of the end wall and located above the pole flange.

[0009] According to the above technical solution, the reinforcing ribs with protrusions are formed by stamping outwards from the inner surface of the end wall, and can be formed in one step during the shell stamping process.

[0010] Optionally, the reinforcing ribs are arranged in a closed manner around the pole hole.

[0011] Optionally, the reinforcing ribs are arranged in segments around the pole hole.

[0012] According to the above technical solution, the anti-torsion effect can be achieved by setting reinforcing ribs in a segmented manner.

[0013] Optionally, the reinforcing ribs are arranged in a single layer around the pole hole, or in multiple layers around the pole hole in the radial direction.

[0014] According to the above technical solution, by increasing the number of reinforcing ribs radially, the deformation resistance of the end wall corresponding to the flanged area of ​​the pole post can be further improved.

[0015] Optionally, a sealing ring is provided between the outer surface of the pole flange and the end wall. The sealing ring has a first recess facing the reinforcing rib and a first protrusion corresponding to the position of the first recess and facing away from the reinforcing rib. The pole flange has a second recess facing the first protrusion. The shape and position of the first recess match the protrusion of the reinforcing rib, and the shape and position of the first protrusion match the second recess.

[0016] According to the above technical solution, both the sealing ring and the pole flange undergo adaptive structural changes based on the raised structure of the reinforcing ribs. This allows the reinforcing ribs, sealing ring, and pole flange to be nested vertically together through a convex-concave structure fit. This makes the mating surfaces less prone to bending under stress and increases the connection strength at the mating points. It further reduces the deformation of the end wall corresponding to the pole flange area, thereby reducing the bending force of the end wall on the pole flange. Simultaneously, it ensures that the compression amount of the sealing ring is uniform across all locations.

[0017] Optionally, the compression of the sealing ring is 25%-45%.

[0018] According to the above technical solution, the sealing ring can ensure sealing performance while avoiding excessive compression that could lead to excessive rebound and deformation of the end wall.

[0019] Optionally, a sealing ring is provided between the outer surface of the pole flange and the end wall. The contact surface between the pole flange and the sealing ring is a plane. The sealing ring satisfies the following formulas: (AB) / A≥25% and (ABh) / A≤45%, where A is the initial thickness of the sealing ring, B is the distance between the bottom surface of the pole flange and the outer surface of the end wall, and h is the protrusion height of the reinforcing rib.

[0020] According to the above technical solution, the compression amount at each position of the sealing ring can be guaranteed, avoiding insufficient sealing performance due to insufficient compression amount or excessive rebound causing end wall deformation due to excessive compression amount.

[0021] The present invention provides a cylindrical battery, comprising the aforementioned casing with a reinforced structure.

[0022] The present invention provides a battery pack comprising the aforementioned cylindrical battery. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the internal riveting structure of the electrode posts in a cylindrical battery.

[0024] Figure 2 This is a schematic diagram of the sealing ring and pole flange in the first embodiment of the present invention, which are arranged according to the shape of the reinforcing rib.

[0025] Figure 3 This is a schematic diagram of the structure of the outer surface of the end wall in the first embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the structure when a sealing ring is installed on the outer surface of the end wall in the first embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of the structure in the second embodiment of the present invention, in which the sealing ring and pole flange are not set according to the shape of the reinforcing rib.

[0028] Reference numerals: End wall 11, Side wall 12, Pole post 13, Pole post flange 131, Pole post flange 132, Sealing ring 14, Outer insulating component 15, Inner insulating component 16, Reinforcing rib 20. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] <First Implementation Method>

[0031] Figure 1 This is a schematic diagram of the internal riveting structure of the electrode posts in a cylindrical battery.

[0032] like Figure 1 As shown, in the internal riveting structure of the cylindrical battery, the housing includes an end wall 11 and a side wall 12 surrounding the end wall 11. The central area of ​​the end wall 11 is provided with a terminal hole for mounting the terminal 13. The terminal 13 is riveted and fixed to the end wall 11 and is insulated from it.

[0033] The upper end of the pole post 13 is a pole post flange 131. A sealing ring 14 and an outer insulating member 15 are provided between the pole post flange 131 and the outer surface of the end wall 11. The sealing ring 14 surrounds the pole post 13 and contacts the bottom surface of the pole post flange 131. The outer insulating member 15 surrounds the sealing ring 14, so that the pole post flange 131 is insulated from the outer surface of the end wall 11.

[0034] The lower end of the pole post 13 is a pole post flange 132. An inner insulating member 16 is provided between the pole post flange 132 and the inner surface of the end wall 11, so that the pole post flange 132 and the inner surface of the end wall 11 are insulatedly connected.

[0035] The pole flange 131 and the pole ferrule 132 clamp the end wall 11 to fix the pole 13 to the end wall 11.

[0036] refer to Figure 1 In the internal riveting structure of the cylindrical battery terminals, the interface between the sealing ring 14 and the terminal flange 131 and the outer surface of the end wall 11 is planar and without reinforcement. Simultaneously, the outer surface of the end wall 11 corresponding to the terminal flange 132 area lacks reinforcement. When the cylindrical battery experiences thermal runaway, the high temperature and pressure generated inside the cell cause deformation of the end wall, which can easily lead to deformation of the terminal flange 132, causing the terminal to fly out.

[0037] Therefore, it is necessary to strengthen the mating interface between the end wall 11 and the sealing ring 14 in the area corresponding to the terminal flange 132, reduce the deformation of the end wall in the area corresponding to the terminal flange 132, thereby reducing the bending force of the end wall 11 on the terminal flange 132, and preventing the terminal from flying out due to thermal deformation when the cylindrical battery experiences thermal runaway.

[0038] Figure 2 This is a schematic diagram of the structure of the sealing ring and pole flange in the first embodiment of the present invention, which are set according to the shape of the reinforcing rib.

[0039] like Figure 2 As shown, in this embodiment, the reinforcing rib 20 protrudes from the outer surface of the end wall 11 and is located above the pole flange 132.

[0040] Specifically, the reinforcing rib 20 is a protruding structure located on the outer surface of the end wall 11, formed by stamping outward from the inner surface of the end wall 11, and can be formed in one step during the shell stamping process.

[0041] refer to Figure 2 and Figure 3 In this embodiment, the reinforcing rib 20 is arranged in a single layer around the pole post hole, and the single layer of reinforcing rib 20 has a total of four segments, which are arranged in a segmented manner around the pole post hole.

[0042] A sealing ring 14 is provided between the outer surface of the pole flange 131 and the end wall 11. The sealing ring 14 has a first recess facing the reinforcing rib 20 and a first protrusion facing away from the reinforcing rib 20, corresponding to the position of the first recess. The pole flange 131 has a second recess facing the first protrusion. The shape and position of the first recess match the protrusion of the reinforcing rib 20, and the shape and position of the first protrusion match the second recess.

[0043] Specifically, refer to Figure 2 and Figure 4 The sealing ring 14, based on the protruding structure of the reinforcing rib 20, has a first recessed portion corresponding to the protruding shape of the reinforcing rib 20 on the side in contact with the reinforcing rib 20, and a first protruding portion corresponding to the side away from the reinforcing rib 20. In this embodiment, the sealing ring 14 undergoes an adaptive structural change according to the protruding shape of the reinforcing rib 20, correspondingly forming a stepped structure with horizontal sides and a protruding middle position.

[0044] refer to Figure 2 The bottom surface of the pole flange 131 contacts the sealing ring 14, and a matching second recess is provided along the first protrusion of the sealing ring 14.

[0045] After the sealing ring 14 and the pole flange 131 undergo adaptive structural changes based on the raised reinforcing rib 20, the reinforcing rib 20 and the sealing ring 14, as well as the sealing ring 14 and the pole flange 131, can be nested and connected through the protruding and recessed fit. By setting the raised reinforcing rib 20, the structural strength can be effectively enhanced, and the deformation of the end wall 11 corresponding to the pole flange 132 can be reduced. At the same time, the concave and convex structure fit between the reinforcing rib 20, the sealing ring 14, and the pole flange 131 makes the mating surface less prone to bending under stress, and also makes the connection strength at the mating position higher, which can further reduce the deformation of the end wall 11 in the area corresponding to the pole flange 132, thereby reducing the bending force of the end wall 11 on the pole flange 132.

[0046] In some embodiments, the reinforcing rib 20 may also be recessed in the end wall 11 and located above the pole flange 132. When recessed, the reinforcing rib 20 can be stamped inwards on the outer surface of the end wall 11 after the housing is stamped, forming a recessed structure. The recessed reinforcing rib 20 can also enhance structural strength and reduce deformation of the end wall 11 corresponding to the pole flange 132. Simultaneously, the sealing ring 14 and the pole flange 131 can also be structurally adjusted according to the recessed structure of the reinforcing rib 20, so that the reinforcing rib 20, sealing ring 14, and pole flange 131 are connected by a concave-convex structure.

[0047] Furthermore, the reinforcing rib 20 is arranged in a segmented manner around the pole hole, and the reinforcing rib 20, the sealing ring 14 and the pole flange 131 are connected by a corresponding protrusion and recess nesting. When the sealing ring 14 and the pole flange 131 twist, they can be limited by the segmented protrusions to achieve the anti-twist effect.

[0048] In some embodiments, the reinforcing rib 20 can also be arranged in a continuous closed form around the pole hole, and the sealing ring 14 and the pole flange 131 can be arranged in a similar shape.

[0049] Furthermore, insufficient compression of the sealing ring 14 will result in poor sealing performance, while excessive compression may cause it to break. Excessive rebound can also lead to end-wall deformation and ultimately, flange deformation of the pole post. Therefore, the compression of the sealing ring 14 needs to be controlled. Specifically, the compression of the sealing ring 14 should be maintained between 25% and 45%. Preferably, the compression is 35%.

[0050] In this embodiment, the sealing ring 14 forms a stepped structure, which enables all positions of the sealing ring 14 to maintain the same amount of compression. This ensures sealing performance while preventing excessive compression from causing excessive rebound and deformation of the end wall.

[0051] The cylindrical battery of this embodiment includes the casing with the above-mentioned reinforced structure, which can prevent the terminals from flying out due to thermal deformation when the cylindrical battery experiences thermal runaway or when the cylindrical battery is subjected to a nail penetration test, thus effectively improving the safety performance of the cylindrical battery.

[0052] The battery pack of this embodiment includes the aforementioned cylindrical batteries, with multiple cylindrical batteries connected in series or parallel to form a battery pack, effectively improving the safety performance of the battery pack. This battery pack can be applied to new energy vehicles / electric vehicles, providing assurance for vehicle safety.

[0053] <Second Implementation Method>

[0054] refer to Figure 5 In this embodiment, the sealing ring 14 and the pole flange 131 do not undergo structural changes according to the reinforcing ribs 20 provided by the protrusion, and two layers of reinforcing ribs 20 are provided to surround the pole hole.

[0055] Furthermore, when the sealing ring 14 and the pole flange 131 are not structurally modified according to the reinforcing rib 20, since the outer surface of the end wall 11 is also provided with a raised reinforcing rib 20, the compression amount of the sealing ring 14 between the outer surface of the end wall 11 and the bottom surface of the pole flange 131, and the compression amount between the reinforcing rib 20 and the bottom surface of the pole flange 131, cannot be guaranteed to be the same, and the compression amount cannot be guaranteed to be maintained between 25% and 45%. Therefore, it is necessary to limit the protrusion height of the reinforcing rib 20 to avoid excessive compression in the corresponding area.

[0056] Specifically, when the sealing ring 14 and the pole flange 131 do not undergo structural changes according to the raised reinforcing rib 20, the contact surface between the pole flange 131 and the sealing ring 14, i.e., the bottom surface of the pole flange 131, is a plane. The sealing ring 14 satisfies the following formulas: (AB) / A≥25% and (ABh) / A≤45%, where A is the initial thickness of the sealing ring 14, B is the distance between the bottom surface of the pole flange 131 and the outer surface of the end wall 11, and h is the raised height of the reinforcing rib 20. By correspondingly limiting the raised height of the reinforcing rib 20, the compression of the sealing ring 14 can be maintained at 25%-45% at each position, which can ensure sealing performance while avoiding excessive compression that would cause excessive rebound and end wall deformation.

[0057] Further, refer to Figure 5 In this embodiment, two layers of reinforcing ribs 20 are provided around the pole hole in the radial direction. By increasing the number of reinforcing ribs 20 in the radial direction, the deformation resistance of the end wall corresponding to the pole flange 132 area can be further improved.

[0058] In some embodiments, the reinforcing ribs 20 surrounding the pole post hole can be configured in two or more layers, which are simply provided on the outer surface of the end wall 11 above the pole post flange 132 area to ensure the end wall's resistance to deformation corresponding to the pole post flange 132 area.

[0059] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A case having a reinforcing structure applied to a cylindrical battery, comprising an end wall and a side wall surrounding the periphery of the end wall, a center region of the end wall is provided with a pole hole for mounting a pole, one end of the pole is a pole flange provided on the outside of the end wall, the other end is a pole turnup provided on the inside of the end wall, the pole flange and the pole turnup clamp the end wall to fix the pole to the end wall, characterized in that, The shell comprises: A reinforcing rib is arranged on the surface of the end wall and above the pole flange.

2. The shell with reinforcing structure according to claim 1, wherein The reinforcing rib is arranged on the outer surface of the end wall and above the pole flange.

3. The shell with reinforcing structure according to claim 1 or 2, wherein The reinforcing rib is arranged in a closed form around the pole hole.

4. The shell with reinforcing structure according to claim 1 or 2, wherein The reinforcing rib is arranged in a segmented form around the pole hole.

5. The shell with reinforcing structure according to claim 1 or 2, wherein The reinforcing rib is arranged in a single layer around the pole hole, or in multiple layers along the radial direction of the pole hole.

6. The shell with reinforcing structure according to claim 2, wherein A sealing ring is arranged between the pole flange and the outer surface of the end wall, the sealing ring has a first recess facing the reinforcing rib, and a first protrusion facing away from the reinforcing rib corresponding to the position of the first recess; the pole flange has a second recess facing the first protrusion; the shape and position of the first recess match the protrusion of the reinforcing rib, and the shape and position of the first protrusion match the second recess.

7. The shell with reinforcing structure according to claim 6, wherein The compression amount of the sealing ring is 25%-45%.

8. The shell with reinforcing structure according to claim 2, wherein A sealing ring is arranged between the pole flange and the outer surface of the end wall, the contact surface between the pole flange and the sealing ring is a plane, and the sealing ring satisfies the formula: (A-B) / A≥25% and (A-B-h) / A≤45%, A is the initial thickness of the sealing ring, B is the distance between the bottom surface of the pole flange and the outer surface of the end wall, and h is the protrusion height of the reinforcing rib.

9. A cylindrical battery, characterized by The cylindrical battery comprises the shell with reinforcing structure according to any one of claims 1-8.

10. A battery pack characterized by comprising: The cylindrical battery comprises the shell with reinforcing structure according to claim 9.

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