Battery cell top cover assembly and secondary battery

Abstract

The utility model provides a battery cell top cover assembly and a secondary battery, and relates to the technical field of battery structures. The battery cell top cover assembly comprises a top cover plate, a pole and lower plastic. The top cover plate is provided with a first side face and a second side face which are opposite, and meanwhile the top cover plate is provided with a pole hole penetrating through the first side face and the second side face. And the pole is arranged in the pole hole and is fixedly connected with the top cover plate through riveting deformation. The lower plastic is located on one side of the second side face of the top cover plate. The pole comprises a pole rod and a limiting plate fixedly connected to one end of the pole rod, the lower plastic comprises a gasket part and a main body part, and the compressive strength of the gasket part is larger than that of the main body part. At least part of the gasket part is clamped between the limiting plate and the second side face, the gasket part is used for bearing riveting pressure during riveting, the gasket part can bear larger riveting pressure, the problem that the lower plastic cement is prone to damage is solved, the main body part is made of materials with small compressive strength, and therefore the problem that the cost of the lower plastic cement is too high can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of battery structures, in particular to a battery core top cover assembly and a secondary battery. Background Art

[0002] With the development of new energy, various electric devices, such as electric vehicles, have received widespread attention, and secondary batteries, as an important device for storing electrical energy, have also developed rapidly.

[0003] In a secondary battery, the cell top cover assembly generally includes a top cover plate, a pole, a sealing ring, an upper plastic and a lower plastic. The pole is in an I-shaped shape and is inserted into the pole hole on the top cover plate. The sealing ring is set on the vertical rod in the middle of the pole to close the gap between the vertical rod and the pole hole. The upper plastic is located on the upper side of the top cover plate and is used to insulate the upper end convex part of the pole from the top cover plate. The lower plastic is located on the lower side of the top cover plate and is used to insulate the lower end convex part of the pole from the top cover plate. However, in this structure, the pole is machined in the middle by machining a groove to form a vertical rod, which increases the cost of the pole. Metal chips are easily hidden in the groove. In the process of injection molding the upper plastic, the metal chips may cause a short circuit and lead to insulation. In order to avoid this technical problem, some poles are currently set to be formed by riveting, so there is no need to machine the groove. However, the inventors have found that the poles made by riveting have the problem of easily damaging the lower plastic. Utility Model Content

[0004] The utility model aims to provide a battery cell top cover assembly, which can improve the problem that the lower plastic is easily damaged by the existing riveting method.

[0005] The utility model also aims to provide a secondary battery, which can improve the technical problem of the lower plastic being easily damaged in the prior art.

[0006] The embodiments of the present invention can be implemented in the following ways:

[0007] A battery cell top cover assembly, the battery cell top cover assembly comprising:

[0008] A top cover plate, the top cover plate having a first side surface and a second side surface opposite to each other; a pole hole is formed on the top cover plate, and the pole hole forms an opening on both the first side surface and the second side surface;

[0009] A pole, which is installed in the pole hole and is fixedly connected to the top cover plate by riveting and deformation; and

[0010] A lower plastic, the lower plastic being located on one side of the second side surface of the top cover plate;

[0011] Among them, the pole includes a pole rod and a limiting plate fixed at one end of the pole rod, the pole rod is inserted into the pole hole, the limiting plate is located on the side of the second side away from the first side, and the outline size of the limiting plate is larger than the pole hole; the lower plastic includes a gasket part and a main body part, the tensile strength of the gasket part is greater than that of the main body part; at least part of the gasket part is clamped between the limiting plate and the second side, and the gasket part is used to withstand the riveting pressure during riveting.

[0012] Optionally, the gasket portion and the main body portion are two independent parts, and the main body portion is fixedly connected to the gasket portion so as to mount the main body portion on the top cover plate.

[0013] Optionally, a first buckle portion is provided on the gasket portion, and a second buckle portion is provided on the main body portion, and the first buckle portion is buckled with the second buckle portion to fix the main body portion on the gasket portion.

[0014] Optionally, the first buckle portion is a hook protrusion provided on the gasket portion, and the second buckle portion is a clearance groove provided on the main body portion.

[0015] Optionally, the main body is directly fixedly connected to the top cover plate.

[0016] Optionally, the pole rod and the limiting plate are an integral structure; the pole further comprises a riveted cover, which is fixed to one end of the pole rod passing through the opening on the first side by riveting, and the outer contour of the riveted cover is larger than the pole hole.

[0017] Optionally, the battery cell top cover assembly also includes a sealing ring, which is sleeved on the pole rod and located between the riveted cover and the first side surface; the sealing ring is used to seal the gap between the pole and the top cover plate, and the sealing ring is used to insulate the riveted cover from the top cover plate.

[0018] Optionally, a step portion is further provided on the pole rod, and the step portion abuts against a side of the riveted cover close to the first side surface to limit the distance between the riveted cover and the first side surface.

[0019] Optionally, an anti-twist structure is provided on the gasket portion, and the anti-twist structure is used to limit the torsion of the pole.

[0020] A secondary battery comprises the above-mentioned battery cell top cover assembly.

[0021] The beneficial effects of the battery cell top cover assembly and the secondary battery provided by the embodiments of the utility model include:

[0022] An embodiment of the utility model provides a battery cell top cover assembly, which includes a top cover plate, a pole and a lower plastic. The top cover plate has a first side surface and a second side surface that are opposite to each other, and the top cover plate has a pole hole that penetrates the first side surface and the second side surface. The pole is installed in the pole hole, and the pole is fixedly connected to the top cover plate by riveting and deformation. The lower plastic is located on one side of the second side surface of the top cover plate. The pole includes a pole rod and a limit plate fixedly connected to one end of the pole rod, the pole rod is inserted into the pole hole, the limit plate is located on the side of the second side surface away from the first side surface, and the outline size of the limit plate is larger than the pole hole, so that the upward movement of the pole relative to the top cover plate can be limited by the limit plate. The lower plastic includes a gasket portion and a main body portion, and the compressive strength of the gasket portion is greater than that of the main body portion. At least a portion of the gasket portion is clamped between the limiting plate and the second side surface, and the gasket portion is used to withstand the riveting pressure during riveting. Since the compressive strength of the gasket portion is greater than that of the main body portion, it can withstand a greater riveting pressure, thereby improving the problem of easy damage to the lower plastic. At the same time, since the main body portion can be made of a material with lower compressive strength, the problem of excessively high cost of the lower plastic can be avoided.

[0023] The embodiment of the utility model further provides a secondary battery, which includes the above-mentioned battery cell top cover assembly, and thus has the beneficial effect of improving the problem of easy damage of the lower plastic and avoiding excessively high cost of the lower plastic. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0025] Figure 1 A schematic diagram of an exploded structure of a battery cell top cover assembly provided according to one aspect of the utility model is shown;

[0026] Figure 2 A schematic cross-sectional structure diagram of a battery cell top cover assembly provided according to one aspect of the utility model is shown;

[0027] Figure 3 Shows Figure 2 A schematic diagram of the enlarged local structure at point A in the middle;

[0028] Figure 4 Shows Figure 3 An exploded view of the structure shown in;

[0029] Figure 5 A partial structural schematic diagram of a first buckle portion and a second buckle portion at a buckling position provided according to one aspect of the utility model is shown;

[0030] Figure 6 Shows Figure 5 The schematic diagram of the structure after the main body is removed from the structure shown;

[0031] Figure 7 A schematic structural diagram of a pole before riveting is shown according to one aspect of the utility model.

[0032] Reference numerals:

[0033] 100-battery cell top cover assembly; 110-top cover plate; 111-first side; 112-second side; 113-pole hole; 114-positive pole hole; 115-negative pole hole; 116-sunk platform; 117-first matching part; 120-pole; 121-positive pole; 122-negative pole; 123-pole rod; 124-limiting plate; 125-riveted cover; 126-first rod section; 127-second rod section; 128-third rod section; 129-step part; 130-lower plastic; 131-gasket part; 132-insulating sleeve; 133-second matching part; 134-anti-twist groove; 135-first buckle part; 136-main body; 137-installation port; 138-second buckle part; 140-sealing ring; 151-pole body. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are only exemplary and should not be construed as limiting the scope of protection of the present invention.

[0035] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", "vertical" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model.

[0036] At the same time, it should be noted that the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified or limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, an integral connection, or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or the internal communication of two components, etc. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Figure 1 This is a schematic diagram of the exploded structure of the battery cell top cover assembly 100 provided in this embodiment. Figure 2 is a schematic cross-sectional structure diagram of the battery cell top cover assembly 100 provided in this embodiment, Figure 3 for Figure 2 A schematic diagram of the enlarged local structure at point A in the middle. Figure 4 for Figure 3 Please refer to the exploded view of the structure shown in Figure 1-Figure 4 This embodiment provides a battery cell top cover assembly 100 and also provides a secondary battery (not shown).

[0039] The secondary battery includes a cell top cover assembly 100 , and the secondary battery also includes other parts of a conventional battery structure, such as a core pack and a shell. The cell top cover assembly 100 is mounted on the shell to form a space for accommodating the core pack.

[0040] The cell top cover assembly 100 includes a top cover plate 110, a pole 120 and a lower plastic 130. The top cover plate 110 has a first side surface 111 and a second side surface 112 opposite to each other, and the top cover plate 110 has a pole hole 113 that penetrates the first side surface 111 and the second side surface 112. The pole 120 is installed in the pole hole 113, and the pole 120 is fixedly connected to the top cover plate 110 by riveting deformation. The lower plastic 130 is located on one side of the second side surface 112 of the top cover plate 110. The pole 120 includes a pole rod 123 and a limiting plate 124 fixedly connected to one end of the pole rod 123. The pole rod 123 is inserted into the pole hole 113. The limiting plate 124 is located on the side of the second side 112 away from the first side 111, and the outline size of the limiting plate 124 is larger than the pole hole 113, so that the pole 120 can be limited by the limiting plate 124 to move upward relative to the top cover plate 110. The lower plastic 130 includes a gasket portion 131 and a main body portion 136. The compressive strength of the gasket portion 131 is greater than that of the main body portion 136. At least a portion of the gasket portion 131 is clamped between the limiting plate 124 and the second side surface 112, and the gasket portion 131 is used to withstand the riveting pressure during riveting. Since the compressive strength of the gasket portion 131 is greater than that of the main body 136, it can withstand a greater riveting pressure, thereby improving the problem of easy damage to the lower plastic 130. At the same time, since the main body 136 can be made of a material with a lower compressive strength, the problem of excessively high cost of the lower plastic 130 can be avoided.

[0041] It should be noted that, generally speaking, the top cover plate 110 is horizontally arranged, and the first side 111 of the top cover plate 110 can also be regarded as the upper surface of the top cover plate 110, and the second side 112 of the top cover plate 110 can also be regarded as the lower surface of the top cover plate 110. In other words, in the description of this embodiment, one side of the first side 111 of the top cover plate 110 can also be described as the upper side of the top cover plate 110, and one side of the second side 112 of the top cover plate 110 can also be described as the lower side of the top cover plate 110.

[0042] The battery cell top cover assembly 100 provided in this embodiment is further described below:

[0043] Please continue to refer to Figure 1-Figure 4 In this embodiment, the top cover plate 110 is made of a plain aluminum plate. The pole 120 includes a positive pole 121 and a negative pole 122. Accordingly, the pole hole 113 on the top cover plate 110 includes a positive pole hole 114 and a negative pole hole 115. The positive pole 121 is installed in the positive pole hole 114, and the negative pole 122 is installed in the negative pole hole 115. In this embodiment, the mounting structure at the positive pole 121 is the same as the mounting structure at the negative pole 122, so the structures at the two places are not described separately. It can be understood that in some other embodiments, the mounting structure at the positive pole 121 and the mounting structure at the negative pole 122 can also be set to be different according to needs.

[0044] Optionally, the pole rod 123 and the limiting plate 124 are an integrated structure, and the integrated structure formed by the pole rod 123 and the limiting plate 124 is a pole body 151. The structure of the pole body 151 before riveting is as follows: Figure 7 Specifically, in this embodiment, the pole body 151 in the positive pole 121 is formed by stamping or cold heading, and the pole body 151 in the negative pole 122 is formed by friction welding or copper-aluminum composite. It can be understood that in some other embodiments, the pole rod 123 and the limit plate 124 can also be provided with a structure connected by other methods, such as riveting connection.

[0045] The pole 120 further includes a riveted cover 125, which is fixed to one end of the pole rod 123 passing through the opening on the first side surface 111 by riveting, and the outer contour of the riveted cover 125 is larger than the pole hole 113. Specifically, the riveted cover 125 is a circular ring structure, the pole hole 113 is a circular hole, and the outer contour of the riveted cover 125 is larger than the pole hole 113, which means that the outer diameter of the riveted cover 125 is larger than the inner diameter of the pole hole 113. During installation, the pole rod 123 is inserted into the pole hole 113 from the lower side of the top cover plate 110, and the upper end of the pole rod 123 is extended from the upper opening of the pole hole 113, so that the upper end of the pole rod 123 is located on the upper side of the top cover plate 110, and then the riveted cover 125 is sleeved on the upper end of the pole rod 123, and the upper end of the pole rod 123 is fixedly connected to the riveted cover 125 through riveting deformation, so that the pole 120 forms an "I"-shaped structure, and the riveted cover 125 limits the downward movement of the pole 120 relative to the top cover plate 110. Optionally, in order to further ensure the connection reliability between the riveted cover 125 and the pole rod 123, after the riveting connection, the riveted cover 125 and the pole rod 123 can also be fixed by laser welding.

[0046] Furthermore, the battery cell top cover assembly 100 also includes a sealing ring 140, which is sleeved on the pole rod 123 and is located between the riveted cover 125 and the first side surface 111. The gap between the pole 120 and the top cover plate 110 is sealed by the sealing ring 140, and the sealing ring 140 can also achieve insulation between the riveted cover 125 and the top cover plate 110. That is, in this embodiment, the sealing ring 140 is placed outside the pole hole 113, replacing the upper plastic used in the prior art to achieve insulation of the upper end of the pole 120. On the one hand, the external placement of the sealing ring 140 can facilitate real-time detection of the sealing state and ensure the sealing effect. On the other hand, the elimination of the upper plastic helps to simplify the structure of the top cover assembly and reduce the size of the battery cell in the height direction.

[0047] Since the riveted cover 125 and the pole rod 123 are fixed by riveting, during riveting, the riveted cover 125 will compress the sealing ring 140, so that the sealing ring 140 has a certain compression amount, thereby ensuring the sealing effect of the sealing ring 140. Moreover, the thickness of the sealing ring 140 after compression is the distance between the riveted cover 125 and the first side surface 111, so that the compression amount change of the sealing ring 140 can be detected in real time and conveniently to ensure the reliability of the seal. Preferably, the compression amount of the sealing ring 140 is 15% to 45%.

[0048] Furthermore, a step portion 129 is provided on the pole rod 123 , and the step portion 129 abuts against a side of the riveted cover 125 close to the first side surface 111 to limit the distance between the riveted cover 125 and the first side surface 111 , thereby achieving control of the compression amount of the sealing ring 140 .

[0049] Specifically, the pole rod 123 includes a first rod segment 126, a second rod segment 127 and a third rod segment 128 which are arranged in sequence from bottom to top, and the radial dimension of the first rod segment 126 is larger than that of the second rod segment 127, and the radial dimension of the second rod segment 127 is larger than that of the third rod segment 128. The first rod segment 126 is located in the pole hole 113, the second rod segment 127 is located on the upper side of the pole hole 113, and the sealing ring 140 is sleeved outside the second rod segment 127. The step surface formed at the upper end of the first rod segment 126 is flush with the first side surface 111, so that the radial inner end of the sealing ring 140 can cooperate with the step surface to further ensure the sealing effect. A step portion 129 is formed at the upper end of the second rod segment 127, and the riveted cover 125 is sleeved outside the third rod segment 128, and is limited by the interference between the step portion 129 and the riveted cover 125.

[0050] In this embodiment, the lower plastic 130 includes a gasket portion 131 and a main body portion 136 which are independent of each other. When installing, the gasket portion 131 is first installed on the top cover plate 110 along with the pole main body 151, and the gasket portion 131 will bear the riveting pressure when the pole 120 is riveted. In order to ensure that the gasket portion 131 can withstand the riveting pressure and avoid damage, the gasket portion 131 can be made of a material with a large tensile strength, including but not limited to Lcp (liquid crystal polymer) or pps (polyphenylene sulfide).

[0051] The main body 136 is installed after the riveting is completed, so the main body 136 will not be subjected to riveting pressure during the riveting process. Accordingly, the main body 136 can be made of a material with a lower tensile strength than the gasket 131, including but not limited to pp (polypropylene). By setting the main body 136 and the gasket 131 to different materials, on the one hand, the gasket 131 can withstand the riveting pressure during riveting, ensuring that the lower plastic 130 is not damaged during riveting. On the other hand, the main body 136 does not need to use a material with higher requirements, which helps to reduce the overall cost of the lower plastic 130.

[0052] Specifically, the gasket portion 131 includes a positive gasket portion 131 disposed at the positive pole 121 and a negative gasket portion 131 disposed at the negative pole 122, and the main body 136 is provided with an installation opening 137 for installing the positive gasket portion 131 and the negative gasket portion 131, that is, the main body 136 is provided with two installation openings 137. After riveting, the gasket portion 131 is clamped and installed on the top cover plate 110 through the joint action of the limit plate 124 and the top cover plate 110, that is, at least part of the gasket portion 131 is clamped between the limit plate 124 and the second side surface 112 of the top cover plate 110, and the limit plate 124 and the top cover plate 110 are insulated by the gasket portion 131. Further, in order to achieve insulation between the pole rod 123 and the top cover plate 110, the gasket portion 131 also includes an insulating sleeve 132 disposed between the pole rod 123 and the pole hole 113. Specifically, the insulating sleeve 132 covers the first rod segment 126 of the pole rod 123 .

[0053] Furthermore, the main body 136 is fixedly connected to the gasket portion 131 , so that the connection with the top cover plate 110 is achieved through the gasket portion 131 , that is, in this embodiment, the main body 136 and the top cover plate 110 are indirectly connected.

[0054] Figure 5 FIG. 1 shows a partial structural diagram of the first buckle portion 135 and the second buckle portion 138 provided in this embodiment at the buckling position. Figure 6 Shows Figure 5 The structure shown is a schematic diagram of the structure after the main body 136 is removed. Optionally, a first snap-on portion 135 is provided on the gasket portion 131, and a second snap-on portion 138 is provided on the main body 136. The main body 136 is fixedly connected to the gasket portion 131 by the snap-on engagement of the first snap-on portion 135 and the second snap-on portion 138. Specifically, the first snap-on portion 135 is a hook protrusion provided on the gasket portion 131, and the second snap-on portion 138 is a clearance groove provided on the main body 136. When snapped, the hook protrusion is snapped with the clearance groove to connect. The two mounting openings 137 of the main body 136 are both provided with a second snap-on portion 138, and the two second snap-on portions 138 are respectively snapped with the first snap-on portion 135 on the positive gasket portion 131 and the first snap-on portion 135 on the negative gasket portion 131, so that the stable installation of the main body 136 is achieved through the snap-on engagement at the two locations. It is understandable that in other embodiments, a connection structure between the gasket portion 131 and the main body portion 136 may be provided as required, or other snap-fit ​​structures may be used to achieve the connection between the gasket portion 131 and the main body portion 136 as required.

[0055] It should be noted that, in some other embodiments, the main body 136 may also be a structure directly connected to the top cover plate 110 , and accordingly, the main body 136 and the gasket portion 131 may be indirectly connected.

[0056] Please refer to it again Figure 1-Figure 4 In this embodiment, an anti-twist structure is provided on the gasket portion 131 , and the anti-twist structure is used to limit the torsion of the pole 120 .

[0057] Optionally, the anti-twist structure includes an anti-twist groove 134 disposed below the gasket portion 131 and a plurality of second matching portions 133 disposed above the gasket portion 131. The limit plate 124 is engaged in the anti-twist groove 134, and the anti-twist groove 134 and the limit plate 124 are both configured to be square or other shapes with inconsistent circumferential dimensions, that is, the limit plate 124 and the anti-twist groove 134 are not in a perfect circle. At the same time, a plurality of first matching portions 117 disposed around the pole hole 113 are also disposed on the second side surface 112 of the top cover plate 110, and the plurality of second matching portions 133 correspond one-to-one to the plurality of first matching portions 117. One of the first matching portion 117 and the second matching portion 133 is a protrusion, and the other of the first matching portion 117 and the second matching portion 133 is a groove, and the protrusion is engaged with the groove. In this way, when the pole 120 is twisted, the anti-twist groove 134 limits the twisting of the limit plate 124 relative to the gasket portion 131, and the first matching portion 117 and the second matching portion 133 cooperate to limit the twisting of the gasket portion 131 relative to the top cover plate 110, thereby playing an anti-twist role. Specifically, as Figure 1-Figure 4 As shown, in this embodiment, the first matching portion 117 is a groove, and the second matching portion 133 is a protrusion. It can be understood that in some other embodiments, the first matching portion 117 can be set as a protrusion, and the second matching portion 133 can be set as a groove.

[0058] It should also be noted that the specific structural form of the anti-twist structure is not limited here. For example, in some other embodiments, the first matching portion 117 can be set on the limiting plate 124, and the second matching portion 133 can be set on the lower side of the gasket portion 131, etc.

[0059] Furthermore, a circle of sinking platform 116 is provided around the pole hole 113 on the second side surface 112 , and the gasket portion 131 is embedded in the cover sinking platform 116 , thereby effectively reducing the height space occupied by the battery top cover assembly 100 . The first matching portion 117 is provided on the bottom surface of the sinking platform 116 .

[0060] The battery cell top cover assembly 100 and the secondary battery provided by the embodiment of the utility model, wherein the pole 120 is fixed on the top cover plate 110 by riveting, which effectively avoids the adverse problems caused by CNC processing of the pole 120; the lower plastic 130 is configured to include a gasket portion 131 and a main body portion 136 with different tensile strengths, and the gasket portion 131 with stronger tensile strength is used to withstand the riveting pressure during riveting, thereby avoiding damage to the lower plastic 130, and the main body portion 136 is made of a material with weaker tensile strength, which effectively reduces the cost of the lower plastic 130. Moreover, the battery cell top cover assembly 100 places the sealing ring 140 externally between the riveted cover 125 and the first side surface 111, and the sealing ring 140 replaces the upper plastic, thereby simplifying the structure of the battery cell top cover assembly 100, which helps to reduce the height space occupied, and the anti-twist structure can effectively prevent the pole 120 from twisting.

[0061] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technology in this field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention.

Claims

1. A battery cell top cover assembly, characterized in that: The battery cell top cover assembly comprises: A top cover plate, the top cover plate having a first side surface and a second side surface opposite to each other; a pole hole is formed on the top cover plate, and the pole hole forms an opening on both the first side surface and the second side surface; A pole, which is installed in the pole hole and is fixedly connected to the top cover plate by riveting and deformation; and A lower plastic, the lower plastic being located on one side of the second side surface of the top cover plate; Among them, the pole includes a pole rod and a limiting plate fixed at one end of the pole rod, the pole rod is inserted into the pole hole, the limiting plate is located on the side of the second side away from the first side, and the outline size of the limiting plate is larger than the pole hole; the lower plastic includes a gasket part and a main body part, the tensile strength of the gasket part is greater than that of the main body part; at least part of the gasket part is clamped between the limiting plate and the second side, and the gasket part is used to withstand the riveting pressure during riveting.

2. The battery cell top cover assembly according to claim 1, characterized in that: The gasket portion and the main body portion are two independent parts, and the main body portion is fixedly connected to the gasket portion so as to mount the main body portion on the top cover plate.

3. The battery cell top cover assembly according to claim 2, characterized in that: The gasket portion is provided with a first buckle portion, and the main body portion is provided with a second buckle portion, and the first buckle portion is buckled with the second buckle portion to fix the main body portion on the gasket portion.

4. The battery cell top cover assembly according to claim 3, characterized in that: The first buckle portion is a hook protrusion arranged on the gasket portion, and the second buckle portion is a clearance groove arranged on the main body portion.

5. The battery cell top cover assembly according to claim 1, characterized in that: The main body is directly fixedly connected to the top cover plate.

6. The battery cell top cover assembly according to claim 1, characterized in that: The pole rod and the limiting plate are an integral structure; the pole further comprises a riveted cover, which is fixed to one end of the pole rod passing through the opening on the first side surface by riveting, and the outer contour of the riveted cover is larger than the pole hole.

7. The battery cell top cover assembly according to claim 6, characterized in that: The battery cell top cover assembly also includes a sealing ring, which is sleeved on the pole rod and located between the riveted cover and the first side surface; the sealing ring is used to seal the gap between the pole and the top cover plate, and the sealing ring is used to insulate the riveted cover from the top cover plate.

8. The battery cell top cover assembly according to claim 7, characterized in that: The pole rod is also provided with a step portion, and the step portion abuts against a side of the riveted cover close to the first side surface to limit the distance between the riveted cover and the first side surface.

9. The battery cell top cover assembly according to claim 1, characterized in that: The gasket portion is provided with an anti-twist structure, and the anti-twist structure is used to limit the torsion of the pole.

10. A secondary battery, characterized in that: The secondary battery comprises the battery cell top cover assembly as described in any one of claims 1 to 9.

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