Cover plate assembly and battery cell

Abstract

The utility model provides a cover plate assembly. The cover plate assembly comprises a cover plate body; the lower plastic comprises a first lower plastic and a second lower plastic and is arranged on the first side, facing the electrode assembly, of the cover plate body; the first pole penetrates through the cover plate body and the first lower plastic cement; the second pole penetrates through the cover plate body and the second lower plastic cement; one of the cover plate body and the lower plastic cement is provided with a clamping part, the other one of the cover plate body and the lower plastic cement is provided with a matching part, the first lower plastic cement and the second lower plastic cement are prevented from rotating through clamping of the clamping part and the matching part, and the first lower plastic cement and the second lower plastic cement are connected. The utility model aims to provide a cover plate assembly and a battery cell so as to at least prevent the first lower plastic cement and the second lower plastic cement from rotating.

Description

Technical Field

[0001] This utility model relates to a cover plate assembly and a battery cell. Background Technology

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Commonly used batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and rechargeable alkaline zinc-manganese batteries. Among these, lithium-ion batteries have become the mainstream power battery for new energy vehicles due to their advantages such as high specific energy, high specific power, long lifespan, and low cost. Utility Model Content

[0003] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a cover plate assembly and a battery cell to at least prevent the first and second lower plastics from rotating.

[0004] To achieve the above objectives, this utility model provides a cover plate assembly, comprising: a cover plate body; a lower plastic, including a first lower plastic and a second lower plastic, disposed on a first side of the cover plate body facing the electrode assembly; a first electrode post passing through the cover plate body and the first lower plastic; a second electrode post passing through the cover plate body and the second lower plastic; one of the cover plate body and the lower plastic has a snap-fit ​​portion, and the other has a mating portion, wherein the snap-fit ​​portion and the mating portion prevent the first lower plastic and the second lower plastic from rotating, and connect the first lower plastic and the second lower plastic.

[0005] In some embodiments, the engagement between the snap-fit ​​portion and the mating portion is a convex-concave fit.

[0006] In some embodiments, a first side of the cover plate body has a recessed portion facing away from the lower plastic recess, the recessed portion forming a mating portion, one of the first lower plastic and the second lower plastic has a first protrusion protruding toward the cover plate body, the other of the first lower plastic and the second lower plastic has a through hole, the first protrusion passes through the through hole and extends into the recessed portion, the first protrusion forming a snap-fit ​​portion.

[0007] In some embodiments, a first side of the cover plate body has a recessed portion that is opposite to the recess of the lower plastic, the recessed portion forming a mating portion, a first lower plastic having a first protrusion extending into the recessed portion, and a second lower plastic having a second protrusion protruding toward the cover plate body and embedded in the first protrusion, the first protrusion and the second protrusion forming a snap-fit ​​portion.

[0008] In some embodiments, the first side of the cover plate body has a recessed portion opposite to the recess of the lower plastic, the recessed portion forming a mating portion, the first lower plastic and the second lower plastic have a through hole, the lower plastic also includes a pin passing through the through hole, the pin protruding from the first lower plastic and the second lower plastic with a first protrusion extending into the recessed portion, the pin forming a snap-fit ​​portion.

[0009] In some embodiments, on the cross section of the axis passing through the first pole post and the axis of the second pole post, the first protrusion has an inverted trapezoidal shape that is wider at the top and narrower at the bottom facing the top of the cover plate body, and the recess has a shape that matches the inverted trapezoidal shape.

[0010] In some embodiments, on a cross section passing through the through hole and perpendicular to the direction from the first pole post to the second pole post, the top of the first protrusion facing the cover plate body has a trapezoidal shape that is narrower at the top and wider at the bottom.

[0011] In some embodiments, the top end is spaced out at a midpoint along the thickness direction of the electrode assembly.

[0012] In some embodiments, the length of the cover body in the direction from the first pole post to the second pole post ranges from 100 mm to 350 mm.

[0013] Embodiments of this application also provide a battery cell, comprising: a housing; a cover assembly of any of the above, the cover assembly covering the housing and defining a receiving cavity with the housing; an electrode assembly, housed within the receiving cavity, wherein a first tab of the electrode assembly is electrically connected to a first terminal, and a second tab of the electrode assembly is electrically connected to a second terminal.

[0014] The beneficial technical effects of this utility model are as follows:

[0015] In the embodiments of this application, one of the cover plate body and the lower plastic has a snap-fit ​​part, and the other has a mating part. The snap-fit ​​part and the mating part are used to prevent the first lower plastic and the second lower plastic from rotating. The snap-fit ​​part and the mating part also connect the first lower plastic and the second lower plastic. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A cover plate assembly of the prior art is shown.

[0018] Figure 2 An electronic device according to an embodiment of this application is shown.

[0019] Figure 3 A perspective view of a battery cell according to a first embodiment of this application is shown.

[0020] Figure 4 A perspective view of a cover plate assembly according to a first embodiment of this application is shown.

[0021] Figure 5 An exploded view of a cover plate assembly according to a first embodiment of this application is shown.

[0022] Figure 6 A perspective view of the second lower plastic facing the cover plate body side according to the first embodiment of this application is shown.

[0023] Figure 7 A perspective view of the first lower plastic facing the cover plate body side according to the first embodiment of this application is shown.

[0024] Figure 8 A top view of the cover plate assembly according to the first embodiment of this application, a cross-sectional view taken along the UU line in the top view, and an enlarged view of the V region in the cross-sectional view are shown.

[0025] Figure 9 A perspective view of a cover plate assembly according to a second embodiment of this application is shown.

[0026] Figure 10 An exploded view of a cover plate assembly according to a second embodiment of this application is shown.

[0027] Figure 11 A top view and a cross-sectional view taken along line WW of the top view are shown of a cover plate assembly according to a second embodiment of this application.

[0028] Figure 12 A cross-sectional view of a cover plate assembly according to a second embodiment of this application, extending along a length direction perpendicular to the first pole post and pointing towards the second pole post, and passing through the first protrusion, is shown.

[0029] Figure 13 The cover assembly is shown in relation to Figure 12 A partial 3D image obtained by cropping from the same plane.

[0030] Figure 14 A perspective view of the cover plate body according to a second embodiment of this application is shown.

[0031] Figure 15 A perspective view of the first and second lower plastics connected together and facing the cover plate body side according to the second embodiment of this application is shown, as well as an enlarged view of region X in the perspective view.

[0032] Figure 16 A perspective view of the second lower plastic facing the cover plate body side according to the second embodiment of this application is shown.

[0033] Figure 17 A perspective view of the first lower plastic facing the cover plate body side according to the second embodiment of this application is shown.

[0034] Figure 18 An exploded view of a battery cell according to a third embodiment of this application is shown.

[0035] Figure 19 A front view of a battery cell according to a third embodiment of this application is shown, as well as a cross-sectional view taken along line AA of the front view.

[0036] Figure 20 A top view of a cover plate assembly according to a fourth embodiment of this application, a cross-sectional view taken along line DD of the top view, a cross-sectional view taken along line EE of the top view, and an enlarged view of region F in the cross-sectional view are shown.

[0037] Figure 21 A top view of a cover plate assembly according to a fifth embodiment of this application, a cross-sectional view taken along line KK of the top view, and an enlarged view of region L in the cross-sectional view are shown.

[0038] Figure 22 The illustration shows a top view of the cover plate assembly facing the electrode assembly according to the sixth embodiment of this application, a cross-sectional view taken along the YY line of the top view, and an enlarged view of the Z region in the cross-sectional view. Detailed Implementation

[0039] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0040] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0041] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0042] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0043] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0044] Figure 1 The diagram illustrates a prior art cover assembly where the lower plastic of a typical battery cell is divided into two halves: a separate lower plastic 1 and a separate lower plastic 2, each fixed to a terminal post 3. However, the longer separate lower plastic 1 can twist, for example, rotating around the terminal post 3, causing interference when the cover assembly is placed over the housing. Furthermore, the position of the Mylar membrane encasing the electrode assembly, which is heat-fused to the lower plastic, is not fixed. The twisted position of the lower plastic can also affect the sealing performance around the terminal post 3, making it crucial to fix the position of the lower plastic.

[0045] This utility model provides an electronic device 1000. For ease of explanation, the following embodiments use a vehicle as an example to illustrate the electronic device 1000. See also... Figure 2The vehicle has a battery pack 1002 installed inside, which can be located at the bottom, front, or rear of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body, and the battery pack 1002 is located at the bottom of the vehicle body, providing electrical power for the vehicle's movement or the operation of its internal electrical components. However, in some other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical energy from the battery pack 1002 and perform corresponding functions, such as a fan blade rotation unit or a vacuum cleaner's suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1000.

[0046] Figure 3 A perspective view of a battery cell 100 according to a first embodiment of this application is shown. Figure 4 A perspective view of a cover plate assembly according to a first embodiment of this application is shown. Figure 5 An exploded view of a cover plate assembly according to a first embodiment of this application is shown. Figure 6 A perspective view of the second lower plastic 22 facing the cover plate body 10 according to the first embodiment of this application is shown. Figure 7 A perspective view of the first lower plastic facing the cover plate body 10 according to the first embodiment of this application is shown. Figure 8 A top view of the cover plate assembly according to the first embodiment of this application, a cross-sectional view taken along the UU line in the top view, and an enlarged view of the V region in the cross-sectional view are shown. Figure 9 A perspective view of a cover plate assembly according to a second embodiment of this application is shown. Figure 10 An exploded view of a cover plate assembly according to a second embodiment of this application is shown. Figure 11 A top view and a cross-sectional view taken along line WW of the top view are shown of a cover plate assembly according to a second embodiment of this application. Figure 12 A cross-sectional view of a cover plate assembly according to a second embodiment of this application, extending along a length direction perpendicular to the first pole post 31 and pointing to the second pole post 32, and passing through the first protrusion 220, is shown. Figure 13 The cover assembly is shown in relation to Figure 12 A partial 3D image obtained by cropping from the same plane. Figure 14 A perspective view of the cover plate body according to a second embodiment of this application is shown. Figure 15 A perspective view of the first lower plastic 21 and the second lower plastic 22 after being connected according to the second embodiment of this application is shown, facing the cover plate body 10, and an enlarged view of the X region in the perspective view is shown. Figure 16 A perspective view of the second lower plastic 22 facing the cover plate body 10 according to the second embodiment of this application is shown. Figure 17 A perspective view of the first lower plastic 21 facing the cover plate body 10 according to the second embodiment of this application is shown.

[0047] The battery cell 100 is, for example, a prismatic battery. The battery cell 100 includes: a housing 102; a cover assembly that covers the housing 102 and defines a receiving cavity within the housing 102; and electrode assemblies 51 and 52 housed within the receiving cavity. The housing 102 includes a bottom wall and side walls surrounding the bottom wall. The receiving cavity houses the electrode assembly 120, electrolyte, and other necessary battery components. Specifically, the size of the housing can be determined based on the specific size and number of the electrode assemblies 51 and 52. The housing can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent the battery casing from rusting during long-term use, a rust-resistant material such as metallic nickel can be plated onto the surface of the housing.

[0048] The cover plate assembly includes a cover plate body (plain aluminum sheet) 10; a first lower plastic 21 and a second lower plastic 22 disposed on the first side of the cover plate body 10 facing the electrode assemblies 51 and 52; a first electrode post 31 passing through the cover plate body 10 and the first lower plastic 21; and a second electrode post 32 passing through the cover plate body 10 and the second lower plastic 22. A first electrode tab (e.g., a positive electrode tab) of the electrode assembly is electrically connected to the first electrode post 31, and a second electrode tab (e.g., a negative electrode tab) of the electrode assembly is electrically connected to the second electrode post 32. The length of the cover plate body 10 in the direction from the first electrode post 31 to the second electrode post 32 ranges from 100 mm to 350 mm, and the first lower plastic 21 is longer than the second lower plastic 22. When the length of the cover plate body 10 is longer, the number of lower plastics can be adjusted according to the length; for example, the cover plate assembly may also include a third lower plastic or more lower plastics. The thickness of the cover plate body 10 is, for example, approximately 2 mm. The cover plate body 10 is provided with an injection hole 14 and an explosion-proof valve 70. The injection hole 14 is located, for example, between the explosion-proof valve 70 and the first electrode post 31, and the explosion-proof valve 70 is located between the injection hole 14 and the second electrode post 32. Along the direction from the cover plate body 10 to the electrode assembly, the portion of the first lower plastic 21 that overlaps with the explosion-proof valve 70 has a plurality of vent holes 82 for venting through the first lower plastic 21.

[0049] The cover plate assembly also includes a first adapter piece 61 and a second adapter piece 62. The first adapter piece 61 has a first electrode post connecting portion 610 located between the electrode assembly and the first lower plastic 21 and electrically connected to the first electrode post 31, and a first electrode tab connecting portion 612 connected to the positive electrode tab of the electrode assembly. Along the direction from the second electrode post 32 to the first electrode post 31, the first electrode tab connecting portion 612 is located on one side of the electrode assembly, and the first electrode post connecting portion 610 is connected to the first electrode tab connecting portion 612. The second adapter piece 62 has a second electrode post connecting portion 620 located between the electrode assembly and the second lower plastic 22 and electrically connected to the second electrode post 32, and a second electrode tab connecting portion 622 connected to the negative electrode tab of the electrode assembly. Along the direction from the second electrode post 32 to the first electrode post 31, the second electrode tab connecting portion 622 is located on the other side of the electrode assembly, and the second electrode post connecting portion 620 is connected to the second electrode tab connecting portion 622.

[0050] In the first and second embodiments, one of the cover plate body 10 and the lower plastic has a snap-fit ​​part, and the other has a mating part. The snap-fit ​​part and the mating part are used to prevent the first lower plastic 21 and the second lower plastic 22 from rotating. The snap-fit ​​part and the mating part also connect the first lower plastic 21 and the second lower plastic 22.

[0051] In the first and second embodiments, the engagement between the snap-fit ​​portion and the mating portion is a convex-concave fit, for example, the protruding snap-fit ​​portion extends into the recessed mating portion to achieve snap-fit ​​and limiting. The cover plate body 10 has a recessed portion 18 on the side facing the electrode assembly, which is opposite to the recesses of the lower plastics 21 and 22. The recessed portion 18 constitutes a mating portion. One of the first lower plastics 21 and the second lower plastic 22 has a first protrusion 220 protruding towards the cover plate body 10. The other of the first lower plastics 21 and the second lower plastic 22 has a through hole 216. The first protrusion 220 passes through the through hole 216 and extends into the recessed portion 18. The first protrusion 220 constitutes a snap-fit ​​portion. The first protrusion 220 passes through the through hole 216 to realize the connection between the first lower plastics 21 and the second lower plastics 22. The first protrusion 220 further extends into the recessed portion 18, and while connecting the first lower plastics 21 and the second lower plastics 22, it also fixes the first lower plastics 21 and the second lower plastics 22 onto the cover plate body 10. In the first and second embodiments, the first protrusion 220 is located on the second lower plastic 22.

[0052] In other embodiments, although not shown in the figures, the first lower plastic 21 may have a first protrusion extending into the recess 18, and the second lower plastic 22 may have a second protrusion protruding toward the cover body 10 and embedded in the first protrusion 220. The first protrusion and the second protrusion together constitute a snap-fit ​​portion. The connection between the first lower plastic 21 and the second lower plastic 22 is achieved by the second protrusion being embedded in the first protrusion. The first protrusion further extends into the recess 18, and while connecting the first lower plastic 21 and the second lower plastic 22, the first lower plastic 21 and the second lower plastic 22 are fixed to the cover body 10. In other embodiments, although not shown in the figures, the first lower plastic 21 and the second lower plastic 22 have through holes. The lower plastic also includes a pin that passes through the through hole. The pin is separate from the first lower plastic 21 and the second lower plastic 22, and a first protrusion of the pin relative to the first lower plastic 21 and the second lower plastic 22 extends into the recess 18. The pin constitutes a snap-fit ​​part. By passing the pin through the through hole of the first lower plastic 21 and the second lower plastic 22, the connection between the first lower plastic 21 and the second lower plastic 22 is realized. The first protrusion of the pin further extends into the recess 18. While connecting the first lower plastic 21 and the second lower plastic 22, the first lower plastic 21 and the second lower plastic 22 are fixed to the cover plate body 10.

[0053] The first protrusion 220 has an inverted trapezoidal shape that is wider at the top and narrower at the bottom, facing the top 222 of the cover plate body 10, and the recess 18 has a shape that matches the inverted trapezoidal shape. As in the first embodiment Figure 8 As shown, the top end 220 is locked inside the recess 18 to prevent the top end 220 from falling out of the recess 18 and to ensure the stability of the engagement. The width of the top end 220 can be greater than the diameter of the through hole 216 in the first lower plastic 21. Since the lower plastics 21 and 22 are elastic, the first protrusion 220 can deform through the through hole 216 and be inserted into the recess 18.

[0054] On a cross-section perpendicular to the axis passing through the through hole 216 and pointing from the first pole post 31 to the second pole post 32, the top end 222 of the first protrusion 220 facing the cover plate body 10 has a trapezoidal shape that is narrower at the top and wider at the bottom. The trapezoidal shape of the top end 222 facilitates the first protrusion 220 passing through the through hole 216 and inserting into the recess 18. As in the second embodiment Figure 12 As shown, the width of the top end 220 can be greater than the diameter of the through hole 216 in the first lower plastic 21. Since the lower plastics 21 and 22 are elastic, and the top end 222 is interrupted at the middle position along the thickness direction of the electrode assembly, the first protrusion 220 can deform through the through hole 216 and insert into the recess 18. The sidewall of the recess 18 can be vertical, or, as in the first embodiment, the diameter of the recess 18 can be wider at the top and narrower at the bottom to hold the top end 222 in place.

[0055] Figure 18 An exploded view of a battery cell 100 according to a third embodiment of this application is shown. Figure 19 A front view of a battery cell 100 according to a third embodiment of this application is shown, as well as a cross-sectional view taken along line AA of the front view.

[0056] Based on the first or second embodiment, the third embodiment further includes a bracket 40 clamped between the adjacent stacked first electrode assembly 51 and second electrode assembly 52 of the electrode assembly, and the bracket 40 has an extension end 42 extending from the first electrode assembly 51 and the second electrode assembly 52, the extension end 42 being inserted into the first lower plastic 21 and the second lower plastic 22 to prevent the first lower plastic 21 and the second lower plastic 22 from rotating.

[0057] Figure 20 A top view, a cross-sectional view taken along line DD of the top view, a cross-sectional view taken along line EE of the top view, and an enlarged view of region F in the cross-sectional view are shown. Although the recess 18 and the shape-fitting structure at the recess 18 are not shown, it can be understood that the fourth embodiment includes the contents of the first or second embodiment.

[0058] Based on the first or second embodiment, in the fourth embodiment, the cover plate body 10 includes a liquid injection boss 12 protruding from a first side facing the electrode assembly, a liquid injection hole 14 penetrating the liquid injection boss 12, and a recess 16 surrounding the liquid injection hole 14 and recessed away from the electrode assembly. The first lower plastic 21 has a protrusion 212 protruding towards the cover plate body 10, the protrusion 212 being inserted into the recess 16 to prevent the first lower plastic 21 from rotating. The first lower plastic 21 has a through hole 211 communicating with the liquid injection hole 14, the protrusion 212 surrounding the through hole 211, the through hole 211 being used for the passage of electrolyte during liquid injection. The fourth embodiment further fixes the first lower plastic 21 at the location of the liquid injection hole 14 to prevent the first lower plastic from tilting or twisting.

[0059] Figure 21 A top view of a cover plate assembly according to a fifth embodiment of this application, a cross-sectional view taken along line KK of the top view, and an enlarged view of region L in the cross-sectional view are shown. Although the recessed portion 18 and the shape-fitting structure at the recessed portion 18 are not shown, it can be understood that the fifth embodiment includes the contents of the first or second embodiment.

[0060] Based on the first or second embodiment, in the fifth embodiment, the first lower plastic 21 has a lower plastic protrusion 213 protruding towards the cover plate body 10 on the side facing the cover plate body 10. The explosion-proof valve 70 has an explosion-proof valve protrusion 72 protruding away from the cover plate body 10 on the first side. The lower plastic protrusion 213 and the explosion-proof valve protrusion 72 abut against each other to restrict the rotation of the first lower plastic 21. There may be a gap between the lower plastic protrusion 213 and the explosion-proof valve protrusion 72, or they may be tightly fitted. Both the lower plastic protrusion 213 and the explosion-proof valve protrusion 72 are circular protrusion structures. The lower plastic protrusion 213 is disposed around the explosion-proof valve protrusion 72. The explosion-proof valve protrusion 72 is provided with a circular explosion-proof valve groove 74 arranged along the extension path of the explosion-proof valve protrusion 72. The opening of the explosion-proof valve groove 74 is away from the first lower plastic 21. The explosion-proof valve 70 includes an overlapping portion 76 surrounding the explosion-proof valve protrusion 72. The overlapping portion 76 overlaps the first protrusion 213 on the side facing the cover plate body 10 and is laser welded to the cover plate body 10.

[0061] Figure 22 The illustration shows a top view of the cover plate assembly facing the electrode assembly according to the sixth embodiment of this application, a cross-sectional view taken along the YY line of the top view, and an enlarged view of the Z region in the cross-sectional view. Although the recessed portion 18 and the shape-fitting structure at the recessed portion 18 are not shown, it can be understood that the sixth embodiment includes the contents of the first or second embodiment.

[0062] Based on the first or second embodiment, in the sixth embodiment, the first adapter piece 61 engages with the first lower plastic piece 21 in a pin-hole manner at a position offset from the first pole post 31 to further prevent the first lower plastic piece 21 from rotating. One of the first lower plastic piece 21 and the first adapter piece 61 is provided with a pin 218, and the other is provided with a hole 616. The pin 218 is inserted into the hole 616 to form a pin-hole engagement. Along the radial direction of the first pole post 31, the hole 616 is located between the first pole post 31 and the first pin 612.

[0063] The fit between the second adapter piece 62 and the second lower plastic is similar to the fit between the first lower plastic and the first adapter piece 61. The second adapter piece 62 is also positioned at a position offset from the second pole post 32 and the second lower plastic 22 by means of a pin hole fit, so as to further prevent the second lower plastic 22 from rotating around the second pole post 32.

[0064] The embodiments of this application, by fixing the first lower plastic 21 and the second lower plastic 22, prevent the first lower plastic 21 and the second lower plastic 22 from twisting / rotating, and simultaneously bring the following advantages: improved sealing around the first electrode post 31 and the second electrode post 32, enhancing the overall safety and airtightness of the battery cell 100; facilitated heat fusion between the Mylar membrane 80 and the first lower plastic 21 and the second lower plastic 22 during the manufacturing process of the battery cell 100; and during the housing insertion process after assembling the cover plate assembly and the electrode assemblies 51 and 52, the first lower plastic 21 and the second lower plastic 22 are properly secured. Plastic 21 and the second lower plastic 22 do not rotate but are centered for easy guidance. The Mylar membrane 80 will not rotate with the first lower plastic 21 and the second lower plastic 22, reducing the friction between the Mylar membrane 80 and the casing 102 and improving the safety performance of the battery cell 100. The positions of the first lower plastic 21 and the second lower plastic 22 are stable, and during the supply chain, transportation and production process, no impurity particles will be generated due to shaking and friction. Impurity particles will bring the risk of corrosion to the battery cell 100. The embodiments of this application improve the safety performance of the battery.

[0065] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A cover plate assembly, characterized in that, include: Cover plate body; The lower plastic, including a first lower plastic and a second lower plastic, is disposed on the first side of the cover plate body facing the electrode assembly; The first pole passes through the cover plate body and the first lower plastic; The second pole passes through the cover plate body and the second lower plastic; The cover plate body and the lower plastic have a snap-fit ​​part and a mating part, respectively. The snap-fit ​​part and the mating part are used to prevent the first lower plastic and the second lower plastic from rotating, and to connect the first lower plastic and the second lower plastic.

2. The cover plate assembly according to claim 1, characterized in that, The engagement between the snap-fit ​​portion and the mating portion is a convex-concave fit.

3. The cover plate assembly according to claim 2, characterized in that, The first side of the cover plate body has a recessed portion that faces away from the lower plastic recess, and the recessed portion constitutes the mating portion. One of the first and second lower plastics has a first protrusion protruding toward the cover plate body, and the other of the first and second lower plastics has a through hole. The first protrusion passes through the through hole and extends into the recess, and the first protrusion constitutes the snap-fit ​​portion.

4. The cover plate assembly according to claim 2, characterized in that, The first side of the cover plate body has a recessed portion that faces away from the lower plastic recess, and the recessed portion constitutes the mating portion. The first lower plastic has a first protrusion extending into the recess, and the second lower plastic has a second protrusion protruding toward the cover plate body and embedded in the first protrusion. The first protrusion and the second protrusion constitute the snap-fit ​​portion.

5. The cover plate assembly according to claim 2, characterized in that, The first side of the cover plate body has a recessed portion that faces away from the lower plastic recess, and the recessed portion constitutes the mating portion. The first and second lower plastics have a through hole, and the lower plastics also include a pin that passes through the through hole. The pin extends into the recessed portion with a first protrusion protruding relative to the first and second lower plastics, and the pin constitutes the snap-fit ​​portion.

6. The cover plate assembly according to any one of claims 3 to 5, characterized in that, In a cross section passing through the axis of the first pole post and the axis of the second pole post, the first protrusion has an inverted trapezoidal shape that is wider at the top and narrower at the bottom facing the top of the cover plate body, and the recess has a shape that matches the inverted trapezoidal shape.

7. The cover plate assembly according to any one of claims 3 and 5, characterized in that, On a cross section passing through the through hole and perpendicular to the direction from the first pole post to the second pole post, the top of the first protrusion facing the cover plate body has a trapezoidal shape that is narrower at the top and wider at the bottom.

8. The cover plate assembly according to claim 7, characterized in that, The top end is spaced out at the middle position along the thickness direction of the electrode assembly.

9. The cover plate assembly according to claim 1, characterized in that, Along the direction from the first pole post to the second pole post, the length of the cover plate body ranges from 100 mm to 350 mm.

10. A battery cell, characterized in that, include: case; The cover assembly as described in any one of claims 1-9, the cover assembly covering the housing and defining a receiving cavity with the housing; An electrode assembly is housed within the receiving cavity, wherein a first tab of the electrode assembly is electrically connected to a first electrode post, and a second tab of the electrode assembly is electrically connected to a second electrode post.

Images