High-heat-resistance battery cell cover plate structure and lithium battery

Abstract

A high-heat-resistance battery cell cover plate structure and a lithium battery. The structure comprises: a top cover plate (1); terminals (2) located on one side of the top cover plate (1); supporting ceramic rings (3) supported between the terminals (2) and the top cover plate (1) and at least partially surrounding the ends of the terminals (2) close to the top cover plate (1), to limit the movement of the terminals (2) towards the top cover plate (1); limiting ceramic rings (4) spaced apart from the supporting ceramic rings (3) and at least partially surrounding the ends of the terminals (2) away from the top cove plate (1), to limit the movement of the terminals (2) away from the top cover plate (1); and fixing assemblies connected to the top cover plate (1) and at least partially surrounding the supporting ceramic rings (3) and the limiting ceramic rings (4), to fix the supporting ceramic rings (3), the limiting ceramic rings (4), and the terminals (2) onto the top cover plate (1). The structure of the terminals of the cover plate is simplified and improved; ceramic rings having a special structural design are used for limiting and mounting poles; and the supporting ceramic rings (3) and the limiting ceramic rings (4) spaced apart from each other are conducive to processing and mounting, and improve the supporting performance.

Description

High heat-resistant battery cell cover structure and lithium battery Technical Field

[0001] The utility model relates to the field of new energy power batteries, and in particular to a high-heat-resistant battery monomer cover plate structure and a lithium battery. Background Art

[0002] Lithium batteries, with their high energy density, lack of memory effect, long single-cell cycle times, high efficiency, cleanliness, and pollution-free properties, are widely used in portable electronic products such as mobile phones, laptops, and digital cameras. They also have promising applications in areas such as electric vehicles. In recent years, with the booming development of the new energy vehicle industry, the new energy vehicle power battery technology industry has also achieved significant development and progress.

[0003] A square power lithium-ion battery consists of a winding core, a shell, and a cover plate. The cover plate has holes and is equipped with a terminal assembly. In addition to serving as a lead-out component for the winding core pole piece, it should also have functions such as sealing, insulation, and high-temperature stability. The design of the terminal assembly structure of a lithium-ion battery is crucial to the safety performance of the battery. To ensure the insulation of the cover plate, the insulation parts in the current market-end terminal assembly structure design are mostly made of PPS material, which has a heat deformation temperature of 260°C and a temperature limit of 220-240°C for long-term use. Taking into account that power lithium-ion batteries may experience extreme high temperatures during service, such as the temperature inside the battery may exceed 250°C during thermal runaway, under such conditions, the insulation structure in the existing technology will no longer meet the insulation performance requirements. Therefore, there is an urgent need for a new type of high-heat-resistant battery cell cover plate structure to ensure the high-temperature stability of the terminal assembly insulation structure.

[0004] Utility Model Content

[0005] 1. Problems to be solved

[0006] In response to the problem in the prior art that insulating parts made of PPS material are assembled at the terminals of the battery cover, which cannot achieve stable insulation performance under high temperature conditions, the utility model provides a high-heat-resistant battery cell cover structure, adopts a specific battery terminal structure, designs and simplifies the terminal connection structure, and can ensure the high-temperature stability of the terminal assembly insulating part structure.

[0007] 2. Technical solution

[0008] In order to solve the above problems, the present invention adopts the following technical solutions.

[0009] A high heat-resistant battery cell cover plate structure includes a top cover plate provided with an electrode lead-out hole, and further includes:

[0010] a terminal, located on one side of the top cover plate and covering the electrode lead-out hole;

[0011] a supporting ceramic ring, supported between the terminal and the top cover plate, and at least partially surrounding an end of the terminal close to the top cover plate to limit the movement of the terminal toward the top cover plate;

[0012] a limiting ceramic ring, spaced apart from the supporting ceramic ring, and at least partially surrounding an end of the terminal away from the top cover plate, so as to limit the movement of the terminal in a direction away from the top cover plate;

[0013] A fixing assembly is connected to the top cover plate and at least partially surrounds the supporting ceramic ring and the limiting ceramic ring to fix the supporting ceramic ring, the limiting ceramic ring and the terminal on the top cover plate.

[0014] The high-heat-resistant battery cell cover plate structure of the utility model simplifies and improves the cover plate terminal structure, and adopts a ceramic ring with a special structural design to limit the installation of the pole. The support ceramic ring and the limiting ceramic ring arranged at intervals can be conveniently processed and installed, and improve the supporting performance. At the same time, it can also ensure the insulation performance of the terminal structure connection, improve the sealing performance, and ensure the high-temperature stability of the terminal structure.

[0015] Furthermore, the supporting ceramic ring includes a base portion supported between the top cover plate and the terminal, and a cylindrical portion surrounding the terminal. Preferably, the terminal includes a columnar body and a flange portion facing the top cover plate, and the limiting ceramic ring includes a radial limiting portion surrounding the columnar body and an axial limiting portion surrounding the flange portion.

[0016] In some possible embodiments, the fixing assembly includes:

[0017] a limiting member connected to the top cover plate and at least partially surrounding the supporting ceramic ring and the limiting ceramic ring to limit the relative positions of the supporting ceramic ring, the limiting ceramic ring and the terminal on the top cover plate;

[0018] The fixing member is connected to the top cover plate and at least partially surrounds the limiting member to fix the limiting member, the supporting ceramic ring, the limiting ceramic ring and the terminal on the top cover plate.

[0019] Furthermore, the top cover plate is provided with a small-diameter primary groove and a large-diameter secondary groove in sequence on the side facing the terminal, and the supporting ceramic ring is arranged on the bottom of the primary groove. The limiting member includes an annular base provided at the bottom of the primary groove, and an extension portion extending and wrapping the outer peripheral wall of the supporting ceramic ring and the limiting ceramic ring, and the outer peripheral wall of the annular base is connected to the inner side wall of the primary groove by welding. The fixing member is formed by an insulating injection molding process, and has a filling portion that fills the gap between the inner side wall of the secondary groove and the outer peripheral wall of the limiting member. The fixing member extends from its filling portion to wrap around the limiting member and the limiting ceramic ring to the outer peripheral wall of the terminal.

[0020] In addition, in order to improve the sealing performance of the pole connection structure, a seal is provided between the terminal and the top cover plate. The seal includes a cylindrical portion wrapping the inner wall of the electrode lead-out hole and an annular portion filled between the terminal and the top cover plate.

[0021] A lithium battery comprises a shell with at least one end open, a battery cell arranged in the shell, and the shell opening is provided with the above-mentioned high heat-resistant battery cell cover plate structure.

[0022] It will be apparent that elements or features described above in connection with a single embodiment may be used alone or in combination in other embodiments.

[0023] 3. Beneficial effects

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] (1) The utility model provides a high-heat-resistant battery cell cover plate structure, which simplifies and improves the cover plate terminal structure and adopts a ceramic ring with a special structural design to limit the installation of the pole. The support ceramic ring and the limiting ceramic ring arranged at intervals can be easily processed and installed, and the supporting performance is improved. At the same time, it can also ensure the insulation performance of the terminal structure connection, improve the sealing performance, and ensure the high-temperature stability of the terminal structure.

[0026] (2) The utility model provides a high-heat-resistant battery cell cover plate structure, which can fasten the supporting ceramic ring, the limiting ceramic ring and the terminal on the top cover plate by setting the limiting parts and the fixing parts, and the top cover plate is provided with a primary sinking groove and a secondary sinking groove, which can play a positioning role when installing the terminal and the connecting structural parts, and increase the compactness and stability of the overall battery cover plate structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In the drawings, the sizes and proportions do not represent the sizes and proportions of actual products. The drawings are merely illustrative and some non-essential elements or features are omitted for clarity.

[0028] FIG1 is a schematic structural diagram of the terminal connection portion of a high-heat-resistant battery cell cover structure in Example 1;

[0029] FIG2 is a perspective view of the high heat-resistant battery cell cover structure of Example 1;

[0030] FIG3 is a schematic structural diagram of the high heat-resistant battery cell cover structure of Example 1 viewed from above.

[0031] Explanation of the accompanying symbols: 1. Top cover plate; 101. Electrode lead-out hole; 102. Primary sink; 103. Secondary sink; 2. Terminal; 201. Columnar body; 202. Flange; 3. Supporting ceramic ring; 301. Base; 302. Cylindrical; 4. Limiting ceramic ring; 401. Radial limiting portion; 402. Axial limiting portion; 5. Limiting member; 501. Annular base; 502. Extension; 6. Fixing member; 7. Sealing member; 701. Cylindrical portion; 702. Annular portion. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below with reference to the accompanying drawings. What is described here is merely a preferred embodiment of the present invention, and those skilled in the art may conceive of other methods for implementing the present invention based on the preferred embodiment, and such other methods also fall within the scope of the present invention.

[0033] Example 1

[0034] This embodiment provides a high-heat-resistant battery cell cover plate structure, which is mainly used in secondary batteries, especially lithium batteries. The high-heat-resistant battery cell cover plate structure can be assembled at the opening of the battery shell and is suitable for batteries with one end open as well as batteries with two ends open.

[0035] As shown in FIG1-3 , the high heat-resistant battery cell cover plate structure mainly includes a top cover plate 1 , terminals 2 mounted on the cover plate, and a connection structure between the two.

[0036] An electrode lead-out hole 101 is provided on the top cover plate 1, and a terminal 2 is provided on one side of the top cover plate 1, and the terminal 2 covers the electrode lead-out hole 101. Specifically, one electrode lead-out hole 101 can be provided on the top cover plate 1 to install the positive terminal 2 or the negative terminal 2, that is, the positive and negative terminals 2 are located at opposite ends of the battery. Two electrode lead-out holes 101 can also be provided on the top cover plate 1 to install the positive terminal 2 and the negative terminal 2, that is, the positive and negative terminals 2 are located at the same end of the battery.

[0037] In order to ensure the insulation between the terminal 2 and the top cover plate 1, an insulating member made of PPS material is installed on the outside of the terminal 2 in the prior art. However, during the use of the battery, thermal runaway and other situations may occur, causing the internal temperature of the battery to be too high. In this environment, the insulating member is heated and can no longer meet the insulation performance requirements.

[0038] To this end, in this embodiment, a supporting ceramic ring 3 is provided between the terminal 2 and the top cover plate 1. The supporting ceramic ring 3 supports the terminal 2 and at least partially surrounds one end of the terminal 2 close to the top cover plate 1 to limit the movement of the terminal 2 toward the top cover plate 1. The ring of ceramic material adopts high-temperature ceramic material, which has good stability and is not easy to melt in a high-temperature environment. It also has the characteristics of good insulation, high strength, and high hardness. Specifically, the supporting ceramic ring 3 includes a base 301 supported between the top cover plate 1 and the terminal 2, and a barrel 302 surrounding the side of the terminal 2. It should be noted that the wrapping or surrounding here and below can be a full or partial wrapping of the wrapped part according to actual conditions.

[0039] Furthermore, a limiting ceramic ring 4 is disposed outside the terminal 2 and spaced apart from the supporting ceramic ring 3. The limiting ceramic ring 4 at least partially surrounds the end of the terminal 2 away from the top cover plate 1, thereby limiting the movement of the terminal 2 in the direction away from the top cover plate 1. The cooperation between the limiting ceramic ring 4 and the supporting ceramic ring 3 can better achieve its insulation performance and can still ensure the insulation effect under high temperature conditions. In addition, the supporting ceramic ring 3 and the limiting ceramic ring 4 are disposed separately, which can facilitate the processing and installation of the two. Leaving a gap between the two can also improve their supporting performance.

[0040] In certain possible embodiments, the terminal 2 includes a connected columnar body 201 and a flange portion 202 facing the top cover plate 1. Furthermore, the limiting ceramic ring 4 includes a radial limiting portion 401 surrounding the circumference of the columnar body 201 to limit radial movement of the terminal 2. The limiting ceramic ring 4 also includes an axial limiting portion 402 surrounding the flange portion 202 to limit axial movement of the terminal 2. In certain possible embodiments, the outer dimensions of the limiting ceramic ring 4 and the supporting ceramic ring 3 may or may not be the same.

[0041] In order to fix the supporting ceramic ring 3, the limiting ceramic ring 4 and the terminal 2 on the top cover plate 1, this embodiment also includes a fixing component connected to the top cover plate 1, which at least partially surrounds the supporting ceramic ring 3 and the limiting ceramic ring 4, so that the supporting ceramic ring 3, the limiting ceramic ring 4 and the terminal 2 can be fixed on the top cover plate 1.

[0042] In some possible embodiments, the fixing assembly may include a limiter 5 and a fixing member 6. The limiter 5 may be connected to the top cover plate 1 by laser welding or other methods, and at least partially surround the supporting ceramic ring 3 and the limiting ceramic ring 4 to limit the relative positions of the supporting ceramic ring 3, the limiting ceramic ring 4, and the terminal 2 on the top cover plate 1.

[0043] In order to better position and install the fixed components, support ceramic ring 3, limit ceramic ring 4 and terminal 2, in some possible embodiments, a small-diameter primary groove 102 and a large-diameter secondary groove 103 are sequentially provided on the side of the top cover plate 1 facing the terminal 2, that is, the diameter of the primary groove 102 is smaller than that of the secondary groove 103, and the support ceramic ring 3 is arranged on the bottom of the primary groove 102.

[0044] The limiting member 5 includes an annular base 501 arranged at the bottom of the primary trough 102, and an extension portion 502 extending and wrapping the outer peripheral wall of the supporting ceramic ring 3 and the limiting ceramic ring 4. The outer peripheral wall of the annular base 501 is connected to the inner wall of the primary trough 102 by welding. The fixing member 6 is formed by an insulating injection molding process, and has a filling portion that fills the gap between the inner wall of the secondary trough 103 and the outer peripheral wall of the limiting member 5. The fixing member 6 extends from its filling portion to wrap around the limiting member 5 and the limiting ceramic ring 4 to the outer peripheral wall of the terminal 2. In this way, it can play a positioning role when installing the terminal 2 and the connecting structural parts, and increase the compactness and stability of the overall battery cover structure. In addition, the limiting member 5 can be made of high-strength metal materials such as aluminum alloy and steel. The raw materials of this material are easy to obtain and low in price. At the same time, the welding difficulty is small and the welding quality is high.

[0045] In addition, to improve the sealing performance of the connection structure between the pole or terminal 2, a seal 7 is also provided between the terminal 2 and the top cover plate 1. The seal 7 includes a cylindrical portion 701 that wraps around the inner wall of the electrode lead-out hole 101, and an annular portion 702 that fills the gap between the terminal 2 and the top cover plate 1. In addition, the seal 7 can be a gasket structure, made of an elastic material with good compressibility, which can be compressed to ensure airtightness. The compression of the gasket can also be ensured by buckling the limiter 5 and welding one end to the top cover plate 1, so that the terminal 2 has good sealing performance.

[0046] Example 2

[0047] This embodiment provides a lithium battery, which is mainly used in new energy power battery modules. Multiple lithium batteries can form a large power battery module to provide power for new energy vehicles and other equipment.

[0048] The lithium battery mainly includes a shell with at least one end open, a battery cell is arranged in the shell, and the high heat-resistant battery cell cover structure in Example 1 is arranged at the shell opening. The connecting piece at the end of the battery cell is electrically connected to the pole to draw out the current.

[0049] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "front", "back", "left", "right", "up", "down", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0050] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0051] The scope of protection of the present invention is limited solely by the claims. Thanks to the teachings of the present invention, those skilled in the art will readily recognize that alternative structures to the structures disclosed in the present invention may be used as viable alternative embodiments, and that the embodiments disclosed in the present invention may be combined to produce new embodiments, which also fall within the scope of the appended claims.

Claims

1. A high heat-resistant battery cell cover plate structure, comprising a top cover plate (1) provided with an electrode lead-out hole (101), characterized in that: Also includes: A terminal (2) is located on one side of the top cover plate (1) and covers the electrode lead-out hole (101); a supporting ceramic ring (3), supported between the terminal (2) and the top cover plate (1), and at least partially surrounding an end of the terminal (2) close to the top cover plate (1) to restrict movement of the terminal (2) toward the top cover plate (1); a limiting ceramic ring (4), spaced apart from the supporting ceramic ring (3), and at least partially surrounding an end of the terminal (2) away from the top cover plate (1), so as to limit movement of the terminal (2) in a direction away from the top cover plate (1); A fixing assembly is connected to the top cover plate (1) and at least partially surrounds the supporting ceramic ring (3) and the limiting ceramic ring (4) to fix the supporting ceramic ring (3), the limiting ceramic ring (4) and the terminal (2) on the top cover plate (1).

2. The high heat-resistant battery cell cover structure according to claim 1, characterized in that: The supporting ceramic ring (3) comprises a base (301) supported between the top cover plate (1) and the terminal (2), and a cylindrical portion (302) surrounding the peripheral side of the terminal (2).

3. The high heat-resistant battery cell cover structure according to claim 1, characterized in that: The terminal (2) comprises a columnar body (201) and a flange portion (202) facing the top cover plate (1); the limiting ceramic ring (4) comprises a radial limiting portion (401) surrounding the circumference of the columnar body (201) and an axial limiting portion (402) surrounding the flange portion (202).

4. The high heat-resistant battery cell cover structure according to claim 1, characterized in that: The fixing assembly includes: a limiting member (5), the limiting member (5) being connected to the top cover plate (1) and at least partially surrounding the supporting ceramic ring (3) and the limiting ceramic ring (4) to limit the relative positions of the supporting ceramic ring (3), the limiting ceramic ring (4) and the terminal (2) on the top cover plate (1); A fixing member (6) is connected to the top cover plate (1) and at least partially surrounds the limiting member (5) to fix the limiting member (5), the supporting ceramic ring (3), the limiting ceramic ring (4) and the terminal (2) on the top cover plate (1).

5. The high heat-resistant battery cell cover structure according to claim 4, characterized in that: A first-level sinking groove (102) with a small diameter and a second-level sinking groove (103) with a large diameter are sequentially provided on the side of the top cover plate (1) facing the terminal (2), and the supporting ceramic ring (3) is arranged on the bottom of the first-level sinking groove (102).

6. The high heat-resistant battery cell cover structure according to claim 5, characterized in that: The limiting member (5) comprises an annular base (501) arranged at the bottom of the primary trough (102), and an extension portion (502) extending and wrapping the outer peripheral walls of the supporting ceramic ring (3) and the limiting ceramic ring (4); the outer peripheral wall of the annular base (501) is connected to the inner side wall of the primary trough (102) by welding.

7. The high heat-resistant battery cell cover structure according to claim 5, characterized in that: The fixing member (6) is formed by an insulating injection molding process and has a filling portion that fills the gap between the inner side wall of the secondary sink (103) and the outer peripheral wall of the limiting member (5).

8. The high heat-resistant battery cell cover structure according to claim 7, characterized in that: The fixing member (6) extends from its filling portion to wrap around the limiting member (5) and the limiting ceramic ring (4) to the outer peripheral wall of the terminal (2).

9. The high heat-resistant battery cell cover structure according to any one of claims 1 to 8, characterized in that: A sealing member (7) is further provided between the terminal (2) and the top cover plate (1), and the sealing member (7) comprises a cylindrical portion (701) wrapping the inner wall of the electrode lead-out hole (101), and an annular portion (702) filling between the terminal (2) and the top cover plate (1).

10. A lithium battery comprising a housing with at least one end open, wherein a battery cell is provided in the housing, characterized in that: The shell opening is provided with the high heat-resistant battery cell cover structure according to any one of claims 1 to 9.

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