Cover assembly of cylindrical lithium battery and single cylindrical lithium battery

Abstract

The utility model relates to the technical field of cylindrical secondary lithium batteries, in particular to a cover assembly of a cylindrical lithium battery and a cylindrical lithium battery monomer, an insulating washer is arranged between an anti-explosion sheet and a pore plate of the cover assembly, the insulating washer comprises a coating part and an extension part, the extension part is in a circular ring shape and is positioned between the anti-explosion sheet and the pore plate, and the coating part is arranged between the coating part and the pore plate. The pressure relief areas of the anti-explosion sheet and the pore plate are correspondingly arranged in the range of the central hole of the extension part, and the coating part coats the anti-explosion sheet and the pore plate and is connected with the outer end of the extension part. The insulating gasket meets the insulating requirement between the explosion-proof sheet and the pore plate, and can reduce the occupied space to the maximum extent and reduce the influence on pressure relief.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of cylindrical secondary lithium battery, specifically relates to a cover assembly of cylindrical lithium battery and a cylindrical lithium battery monomer. BACKGROUND

[0002] Cylindrical lithium battery has the advantages of high working voltage, large energy density, long cycle life, low self-discharge rate and small monomer volume, and becomes the power energy favored by home appliances, vehicle electricity and the like. In the process of assembling and sealing of the cylindrical lithium battery, the sealing ring of the combined cap is extruded and deformed to ensure the sealing of the battery and prevent liquid leakage or direct contact with the outside world.

[0003] The cover assembly of the cylindrical lithium battery is provided with a burst valve. When the internal pressure of the battery monomer reaches the threshold of the burst valve, the burst valve is opened to release pressure, and the pressure release rate is directly related to the area of the pressure release through hole of the cover assembly. In the conventional cover assembly, the edge of the hole plate exceeds the bending part of the burst disc. To avoid interference with the sealing ring, the outer diameter of the pressure release through hole of the hole plate and the diameter of the burst disc are limited. Taking a 21700 cylindrical battery monomer as an example, the outer diameter of the pressure release through hole of the conventional structure hole plate and the diameter of the burst disc are difficult to exceed 11mm, resulting in limited area of the pressure release through hole of the cover assembly, insufficient pressure release rate when the battery cell is in thermal runaway, and possible rupture of the shell side wall.

[0004] To solve the above technical problems, a cover assembly of a cylindrical lithium battery and a cylindrical lithium battery monomer using the cover assembly are provided. Utility model content

[0005] The utility model solves the technical problem to provide a cover assembly of a cylindrical lithium battery and a cylindrical lithium battery monomer, saves the space occupation in the cover, increases the area of the pressure release through hole of the cover assembly, improves the top pressure release rate when the battery cell is in thermal runaway, and improves the safety performance of the battery cell.

[0006] To solve the above technical problems, the utility model adopts the technical scheme that a cover assembly of a cylindrical lithium battery, including a top cover, a burst disc, an insulating gasket, a hole plate and a sealing ring, the hole plate is arranged in the sealing ring, the burst disc is arranged above the hole plate, the insulating gasket is arranged between the burst disc and the hole plate, the top cover is arranged in the sealing ring and connected between the burst disc, the insulating gasket includes a cladding part and an extension part, the extension part is circular, the extension part is located between the burst disc and the hole plate and abuts against the lower end surface of the burst disc and the upper end surface of the hole plate, the cladding part is cylindrical, the cladding part is wrapped outside the burst disc and the hole plate and connected with the outer end of the extension part, and the cladding part and the extension part are integrated. The insulating gasket with T-shaped cross section isolates the burst disc and the hole plate, not only meets the insulation requirement between the burst disc and the hole plate, but also maximally reduces the space occupation and reduces the influence on pressure release.

[0007] As an optional scheme, the insulating gasket is made of PBT or PFA.

[0008] As an optional scheme, the part of the covering part above the extension part is equal to the part below the extension part, the thickness of the covering part is 0.2cm-0.4cm, and the thickness of the extension part is 0.2cm-0.4cm.

[0009] Based on the same concept, the utility model also provides a cylindrical lithium battery monomer, including the above-mentioned cover assembly.

[0010] Compared with the prior art, the utility model has the beneficial effects that: 1, the combination cover adopts the insulating gasket with T-shaped cross section to isolate the explosion-proof sheet and the hole plate, not only meets the insulation requirement between the explosion-proof sheet and the hole cover plate, but also maximally reduces the space occupation, increases the area of the pressure relief channel of the cover assembly, improves the top pressure relief rate when the battery cell is in thermal runaway, and improves the safety performance of the battery cell; 2, the covering part of the insulating gasket covers the hole plate, and the broken hole plate cannot move to the position of contacting the steel shell or damaging the pole group. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor on the premise of not paying creative labor.

[0012] Figure 1 It is an explosion schematic view of the cover assembly;

[0013] Figure 2 It is a cross-sectional schematic view of the cover assembly;

[0014] Figure 3 It is Figure 2 The enlarged view of A in the middle;

[0015] In the figure: 1, top cover, 2, explosion-proof sheet, 3, insulating gasket, 31, covering part, 32, extension part, 4, hole plate, 5, sealing ring. DETAILED DESCRIPTION

[0016] The technical scheme in the embodiments of the utility model will be clearly and completely described in combination with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0017] Embodiment 1

[0018] Please refer to 1- Figure 3 A cover assembly of a cylindrical lithium battery includes a top cover 1, a rupture disc 2, an insulating gasket 3, a hole plate 4 and a sealing ring 5, the hole plate 4 is arranged in the sealing ring 5, the rupture disc 2 is arranged above the hole plate 4, the pressure relief area of the rupture disc 2 corresponds to the pressure relief hole area of the hole plate 4, the insulating gasket 3 is arranged between the rupture disc 2 and the hole plate 4, and the top cover 1 is arranged in the sealing ring 5 and connected with the rupture disc 2. The assembly relationship of the top cover 1, the rupture disc 2, the insulating gasket 3, the hole plate 4 and the sealing ring 5 can also be referred to the authorized announcement No. CN221805772U, and the patent name is 202323162607.3 A combined cap cover with a notch on the top cover 1 and a battery monomer, which will not be described here.

[0019] The insulating gasket 3 includes a cladding part 31 and an extension part 32, and the cladding part 31 and the extension part 32 are of an integral structure. The extension part 32 is in a circular ring shape, the extension part 32 is located between the rupture disc 2 and the hole plate 4, the upper end surface of the extension part 32 is in contact with the lower end surface of the rupture disc 2, the lower end surface of the extension part 32 is in contact with the upper end surface of the hole cover plate, the extension part 32 is fixed by being extruded by the rupture disc 2 and the hole plate 4, and the pressure relief area of the rupture disc 2 and the pressure relief hole area of the hole cover plate are both within the range of the central hole of the extension part 32. The cladding part 31 is in a cylindrical shape, the cladding part 31 clads outside the rupture disc 2 and the hole plate 4, the inner end surface of the cladding part 31 is in contact with the outer end surface of the rupture disc 2 and the hole plate 4, and when the battery cell is in thermal runaway, the broken hole plate 4 and other structures will not move to a position in contact with the battery steel shell under the action of the cladding part 31, so as to avoid damaging the pole group. The inner end surface of the cladding part 31 is also connected with the outer end of the extension part 32.

[0020] Please refer to Figure 2 and Figure 3 The cross section of the insulating gasket is in a T shape, the cladding part 31 clads the rupture disc 2 and the hole plate 4, and the extension part 32 extends to between the rupture disc 2 and the hole plate 4. The structure of the T-shaped cross section of the insulating gasket not only meets the insulation requirement between the rupture disc 2 and the hole plate 4, but also maximally reduces the space occupation, thereby saving space for the rupture line of the rupture disc 2 and the pressure relief hole of the hole plate 4.

[0021] The part of the cladding part 31 above the extension part 32 is equal to the part below the extension part 32, the thickness of the cladding part 31 is 0.2cm-0.4cm, and the thickness of the extension part 32 is 0.2cm-0.4cm.

[0022] The insulating gasket is made of PBT or PFA or other high-temperature-resistant plastics by injection molding.

[0023] Example 2

[0024] A cylindrical lithium battery monomer includes the cover assembly of example 1.

[0025] In the description of the present specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0026] The above merely describes a preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art, within the technical range disclosed by the present application, according to the technical scheme and the inventive concept of the present application, makes equivalent substitutions or changes, should be covered within the protection scope of the present application.

Claims

1. A cover assembly of a cylindrical lithium battery, comprising a top cover (1), a rupture disc (2), an insulating washer (3), a hole plate (4) and a sealing ring (5), the hole plate (4) is arranged in the sealing ring (5), the rupture disc (2) is arranged above the hole plate (4), the insulating washer (3) is arranged between the rupture disc (2) and the hole plate (4), and the top cover (1) is arranged in the sealing ring (5) and connected between the rupture disc (2), characterized in that: the insulating washer (3) comprises a covering part (31) and an extending part (32), the extending part (32) is in a circular ring shape, the extending part (32) is located between the rupture disc (2) and the hole plate (4) and abuts against the lower end surface of the rupture disc (2) and the upper end surface of the hole plate (4), the covering part (31) is in a cylindrical shape, the covering part (31) covers the outside of the rupture disc (2) and the hole plate (4) and is connected with the outer end of the extending part (32), and the covering part (31) and the extending part (32) are in an integrated structure. The insulating washer (3) is made of PBT or PFA.

2. The lid assembly of the cylindrical lithium battery according to claim 1, characterized in that: The part of the covering part (31) above the extending part (32) is equal to the part below the extending part (32), the thickness of the covering part (31) is 0.2-0.4 cm, and the thickness of the extending part (32) is 0.2-0.4 cm.

3. The lid assembly of the cylindrical lithium battery according to claim 1, wherein: The cover assembly according to any one of claims 1-3.

4. A cylindrical lithium battery cell characterized by: ​

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