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 first lower plastic cement and the second lower plastic cement are 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; the anti-explosion valve is fixed on the cover plate body, one of the anti-explosion valve and the lower plastic cement is provided with a clamping part, the other one of the anti-explosion valve and the lower plastic cement is provided with a matching part, and rotation of the first lower plastic cement is limited through clamping of the clamping part and the matching part. The utility model aims to provide a cover plate assembly and a battery cell so as to at least limit rotation of first lower plastic cement.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of cover plate assembly and electric core. BACKGROUND

[0002] Batteries are widely used in electronic devices, such as mobile phones, laptops, electric cars, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools, etc. The common batteries at present include cadmium-nickel batteries, hydrogen-nickel batteries, lithium-ion batteries and secondary alkaline zinc-manganese batteries, etc. Among them, lithium-ion batteries have become the mainstream power battery of new energy vehicles due to their high specific energy, high specific power, long life, low cost and other advantages. SUMMARY

[0003] In view of the problems in the related art, the utility model aims to provide a cover plate assembly and an electric core to at least limit the rotation of the first lower plastic.

[0004] To achieve the above-mentioned purpose, the utility model provides a cover plate assembly, comprising: a cover plate body; a first lower plastic and a second lower plastic, arranged on the first side of the cover plate body facing the electrode assembly; a first pole, passing through the cover plate body and the first lower plastic; a second pole, passing through the cover plate body and the second lower plastic; an explosion-proof valve, fixed on the cover plate body, one of the lower plastics has a clamping part, and the other has a matching part, which limits the rotation of the first lower plastic by clamping the clamping part and the matching part.

[0005] In some embodiments, the first lower plastic has a first protruding part protruding towards the cover plate body on the side facing the cover plate body, the first protruding part constitutes the matching part, the explosion-proof valve has a second protruding part protruding away from the cover plate body on the first side, the second protruding part constitutes the clamping part, and the first protruding part and the second protruding part abut to limit the rotation of the first lower plastic.

[0006] In some embodiments, the first protruding part and the second protruding part are both a ring of protruding structures.

[0007] In some embodiments, the first protruding part is arranged outside the second protruding part.

[0008] In some embodiments, a ring of grooves is arranged along the extension path of the second protruding part in the second protruding part, and the opening of the groove is away from the first lower plastic.

[0009] In some embodiments, the explosion-proof valve comprises a lap joint part around the second protruding part, which is lapped on the side of the first protruding part facing the cover plate body.

[0010] In some embodiments, the outer periphery of the explosion-proof valve is a groove structure opening towards the first lower plastic, the groove structure constitutes a clamping portion, the first lower plastic has a first protruding portion extending into the groove structure on the side facing the cover body, and the first protruding portion constitutes a matching portion.

[0011] In some embodiments, the groove structure includes a ring of grooves, and the first protruding portion is a ring of protruding structures embedded in the ring of grooves.

[0012] In some embodiments, the explosion-proof valve further includes a weak portion, the thickness of the weak portion is less than the thickness of other portions of the explosion-proof valve, and the second protruding portion or the groove structure is arranged around the weak portion.

[0013] In some embodiments, the first lower plastic has a third protruding portion protruding towards the cover body on the side facing the cover body, the third protruding portion is located between the first protruding portion and the second lower plastic, and abuts against the cover body.

[0014] In some embodiments, the length of the cover body in the direction from the first pole column to the second pole column ranges from 100 mm to 350 mm.

[0015] Embodiments of the present application also provide an electric core, comprising: a shell; the cover plate assembly of any one of the above, the cover plate assembly covering the shell and defining a containing cavity with the shell; and an electrode assembly contained in the containing cavity, a first tab of the electrode assembly being electrically connected to the first pole column, and a second tab of the electrode assembly being electrically connected to the second pole column.

[0016] The beneficial technical effects of the present application are as follows:

[0017] In embodiments of the present application, one of the explosion-proof valve and the lower plastic (including the first lower plastic and the second lower plastic) has a clamping portion, and the other has a matching portion, and the first lower plastic is limited from rotating by clamping of the clamping portion and the matching portion (i.e., positioning by the shape contour). BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 A cover plate assembly of the prior art is shown.

[0020] Figure 2 An electronic device according to embodiments of the present application is shown.

[0021] Figure 3A perspective view of the battery cell according to the first embodiment of the present application is shown.

[0022] Figure 4 A perspective view of the cover plate assembly according to the first embodiment of the present application is shown.

[0023] Figure 5 An exploded view of the cover plate assembly according to the first embodiment of the present application is shown.

[0024] Figure 6 A top view of the cover plate assembly according to the first embodiment of the present application, a sectional view taken along the K-K line of the top view, and an enlarged view of the L region in the sectional view are shown.

[0025] Figure 7 A perspective view of the first lower plastic facing the cover plate body side according to the first embodiment of the present application is shown.

[0026] Figure 8 A perspective view of the explosion-proof valve facing the cover plate body side according to the first embodiment of the present application is shown.

[0027] Figure 9 A perspective view of the explosion-proof valve facing the electrode assembly side according to the first embodiment of the present application is shown.

[0028] Figure 10 A top view of the explosion-proof valve facing the cover plate body side according to the first embodiment of the present application, a sectional view taken along the M-M line of the top view, and an enlarged view of the O region in the sectional view are shown.

[0029] Figure 11 A top view of the cover plate assembly according to the second embodiment of the present application, a sectional view taken along the P-P line of the top view, and an enlarged view of the Q region in the sectional view are shown.

[0030] Figure 12 A perspective view of the first lower plastic facing the cover plate body side according to the second embodiment of the present application is shown.

[0031] Figure 13 A front view of the first lower plastic according to the second embodiment of the present application is shown.

[0032] Figure 14 A top view of the first lower plastic facing the cover plate body side according to the second embodiment of the present application is shown.

[0033] Figure 15 A perspective view of the explosion-proof valve facing the electrode assembly side according to the second embodiment of the present application is shown.

[0034] Figure 16A top view of a side of the explosion-proof valve facing the electrode assembly, a sectional view taken along the R-R line of the top view, and an enlarged view of a T region in the sectional view are shown according to a second embodiment of the present application.

[0035] Figure 17 An exploded view of the battery cell according to a third embodiment of the present application is shown.

[0036] Figure 18 A front view of the battery cell according to the third embodiment of the present application, and a sectional view taken along the A-A line of the front view are shown.

[0037] Figure 19 A top view of the cover plate assembly according to a fourth embodiment of the present application, a sectional view taken along the D-D line of the top view, a sectional view taken along the E-E line of the top view, and an enlarged view of a region F in the sectional view are shown.

[0038] Figure 20 A top view of the cover plate assembly according to a fifth embodiment of the present application, a sectional view taken along the U-U line of the top view, and an enlarged view of a V region in the sectional view are shown.

[0039] Figure 21 A top view of a side of the cover plate assembly facing the electrode assembly, a sectional view taken along the Y-Y line of the top view, and an enlarged view of a Z region in the sectional view are shown according to a sixth embodiment of the present application. DETAILED DESCRIPTION

[0040] For better understanding of the spirit of the embodiments of the present application, the same will be further described below in conjunction with some preferred embodiments of the present application.

[0041] The embodiments of the present application will be described in detail below. In the entire description of the present application, the same or similar components and components having the same or similar functions are denoted by similar reference numerals. The embodiments described herein with respect to the accompanying drawings are illustrative in nature, diagrammatic in nature, and are used to provide a basic understanding of the present application. The embodiments of the present application should not be interpreted as a limitation of the present application.

[0042] As used herein, the terms "approximately", "substantially", "essentially", and "about" are used to describe and account for small variations. When used in connection with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs exactly, as well as instances in which the event or circumstance occurs approximately.

[0043] In this description, relative terms such as "central," "longitudinal," "lateral," "forward," "rearward," "rightward," "leftward," "internal," "external," "lower," "higher," "horizontal," "vertical," "above," "below," "top," "bottom," and derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the embodiments of the application still operate effectively. The terms of degree such as "proximal," "distal," "superior," "inferior," "superiorly," "inferiorly," "superiorly," "inferiorly," etc. are used herein with reference to a particular one of the embodiments described herein. However, it will be appreciated that a specific structural orientation or orientation is not required unless specifically designated or limited.

[0044] For ease of description, "first," "second," "third," etc. can be used herein to distinguish between different components of one figure or series of figures. "First," "second," "third," etc. are not intended to describe corresponding components.

[0045] Figure 1 The prior art cover plate assembly is shown, wherein the lower plastic of the general battery is divided into two halves, including split lower plastic 1, split lower plastic 2, respectively fixed on the pole 3, and the longer split lower plastic 1 is too long to twist, such as rotating around the pole 3, resulting in interference with the shell when the cover plate assembly is covered on the shell; the position of the mylar film wrapped around the electrode assembly and the lower plastic hot melt is not fixed; the position of the twisted lower plastic will also affect the sealing performance around the pole 3 to some extent, so the position of the fixed lower plastic will be particularly important

[0046] The utility model provides a kind of electronic device 1000, the following embodiment is for the convenience of explanation, and electronic device 1000 is taken as vehicle to explain. Referring to Figure 2The vehicle is internally provided with a battery pack 1002, which can be arranged at the bottom, head or tail of the vehicle body 1001. The battery pack 1002 can be used for power supply of the vehicle, for example, the battery pack 1002 can be used as the operating power supply of the vehicle. The working part of the electronic device 1000 is electrically connected with the battery pack 1002 to obtain electric energy support. The vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid automobile or a range extended automobile, but is not limited thereto. The working part is the vehicle body, the battery pack 1002 is arranged at the bottom of the vehicle body, and provides electric energy support for driving of the vehicle or operation of electrical elements in the vehicle. However, in other embodiments, the electronic device 1000 can also be a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The working part can obtain electric energy from the battery pack 1002, and make corresponding working unit parts, such as a fan blade rotating unit, a dust suction working unit of a dust collector, etc. The electric toy includes a fixed or mobile electric toy, such as a game machine, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer, etc. The electronic device 1000 is not specially limited in the embodiments of the present application.

[0047] Figure 3 A perspective view of the battery cell 100 according to the first embodiment of the present application is shown. Figure 4 A perspective view of the cover plate assembly according to the first embodiment of the present application is shown. Figure 5 An exploded view of the cover plate assembly according to the first embodiment of the present application is shown. Figure 6 A top view of the cover plate assembly according to the first embodiment of the present application, a sectional view taken along the K-K line of the top view, and an enlarged view of the L area in the sectional view are shown. Figure 7 A perspective view of the first lower plastic 21 facing the cover plate body 10 side according to the first embodiment of the present application is shown. Figure 8 A perspective view of the explosion-proof valve 70 facing the cover plate body 10 side according to the first embodiment of the present application is shown. Figure 9 A perspective view of the explosion-proof valve 70 facing the electrode assembly side according to the first embodiment of the present application is shown. Figure 10 A top view of the explosion-proof valve 70 facing the cover plate body 10 side according to the first embodiment of the present application, a sectional view taken along the M-M line of the top view, and an enlarged view of the O area in the sectional view are shown.

[0048] Figure 11A top view of the cover plate assembly according to the second embodiment of the present application, a sectional view taken along the P-P line of the top view, and an enlarged view of the Q area in the sectional view are shown. Figure 12 A perspective view of the first lower plastic 21 facing the cover plate body 10 side according to the second embodiment of the present application is shown. Figure 13 A front view of the first lower plastic 21 according to the second embodiment of the present application is shown. Figure 14 A top view of the first lower plastic 21 facing the cover plate body 10 side according to the second embodiment of the present application is shown. Figure 15 A perspective view of the explosion-proof valve 70 facing the electrode assembly side according to the second embodiment of the present application is shown. Figure 16 A top view of the explosion-proof valve 70 facing the electrode assembly side according to the second embodiment of the present application, a sectional view taken along the R-R line of the top view, and an enlarged view of the T area in the sectional view are shown.

[0049] The electric cell 100 is, for example, a square battery, and includes a housing 102, a cover plate assembly covering the housing 102 and defining a containing cavity with the housing 102, and an electrode assembly 51, 52 contained in the containing cavity. The housing 102 includes a bottom wall and a side wall surrounding the bottom wall, and the containing cavity contains the electrode assembly 120, electrolyte, and other necessary components of the battery. Specifically, the size of the housing can be determined according to the specific size and number of the electrode assembly 51, 52. The material of the housing can be various, such as copper, iron, aluminum, steel, aluminum alloy, etc., and a layer of anti-rust material such as metal nickel can be plated on the surface of the housing to prevent rusting of the battery shell during long-term use.

[0050] The cover plate assembly includes a cover plate body (aluminum sheet) 10, a first lower plastic 21 and a second lower plastic 22 arranged on the first side of the cover plate body 10 facing the electrode assembly 51, 52, a first pole 31 passing through the cover plate body 10 and the first lower plastic 21, and a second pole 32 passing through the cover plate body 10 and the second lower plastic 22, with the first pole 31 electrically connected to the first tab of the electrode assembly (for example, the positive electrode tab), and the second pole 32 electrically connected to the second tab of the electrode assembly (for example, the negative electrode tab). In the direction from the first pole 31 to the second pole 32, the length of the cover plate body 10 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 further includes a third lower plastic or more lower plastics. The thickness of the cover plate body 10 is, for example, about 2 mm. The cover plate body 10 is provided with a liquid injection hole 14 and an explosion-proof valve 70, the liquid injection hole 14 is, for example, located between the explosion-proof valve 70 and the first pole 31, and the explosion-proof valve 70 is located between the liquid injection hole 14 and the second pole 32.

[0051] The cover plate assembly further comprises a first adapter plate 61 and a second adapter plate 62. The first adapter plate 61 has a first pole post connecting portion 610 located between the electrode assembly and the first lower plastic 21 and electrically connected with the first pole post 31, and a first tab connecting portion 612 connected with the positive electrode tab of the electrode assembly, the first tab connecting portion 612 is located on one side of the electrode assembly in the direction from the second pole post 32 to the first pole post 31, and the first pole post connecting portion 610 is connected with the first tab connecting portion 612. The second adapter plate 62 has a second pole post connecting portion 620 located between the electrode assembly and the second lower plastic 22 and electrically connected with the second pole post 32, and a second tab connecting portion 622 connected with the negative electrode tab of the electrode assembly, the second tab connecting portion 622 is located on the other side of the electrode assembly in the direction from the second pole post 32 to the first pole post 31, and the second pole post connecting portion 620 is connected with the second tab connecting portion 622.

[0052] In the first and second embodiments, the explosion-proof valve 70 has a clamping portion in one of the lower plastics (including the first lower plastic 21 and the second lower plastic 22) and a matching portion in the other, and the first lower plastic 21 is limited from rotating by clamping of the clamping portion and the matching portion (i.e. positioning by the contour).

[0053] In the first embodiment, the first lower plastic 21 has a first protruding portion 213 protruding towards the cover plate body 10 on the side facing the cover plate body 10, the first protruding portion 213 constitutes a matching portion, the explosion-proof valve 70 has a second protruding portion 72 protruding away from the cover plate body 10 on the first side, the second protruding portion 72 constitutes a clamping portion, the first protruding portion 213 and the second protruding portion 72 abut to realize the clamping of the clamping portion and the matching portion, thereby limiting the rotation of the first lower plastic 21. There can be a gap between the first protruding portion 213 and the second protruding portion 72, or it can be a tight fit. The first protruding portion 213 and the second protruding portion 72 are both a circle of protruding structures, so they can abut each other on the whole circle, which is beneficial to the fixation of the first lower plastic 21. The first protruding portion 213 is arranged outside the second protruding portion 72, that is, the first protruding portion 213 surrounds the second protruding portion 72, and the first lower plastic 21 covers the second protruding portion 72. It can be understood that although it is not shown in the figure, the second protruding portion 72 can also be arranged outside the first protruding portion 213, and the first protruding portion 213 is limited in the second protruding portion 72 to fix the first lower plastic. The second protruding portion 72 is provided with a circle of grooves 74 arranged along the extension path of the second protruding portion 72, the opening of the groove 74 faces away from the first lower plastic 21, and the second protruding portion 72 is not a solid structure, which can reduce the weight of the explosion-proof valve 70, and the groove 74 can absorb the deformation generated when the explosion-proof valve 70 is welded with the cover plate body 10. The explosion-proof valve 70 includes a lap portion 76 surrounding the second protruding portion 72, the lap portion 76 is lapped on the side of the first protruding portion 213 facing the cover plate body 10, and is laser welded with the cover plate body 10. By arranging the lap portion 76, the height difference between the cover plate body 10 and the edge portion of the explosion-proof valve 70 is reduced, which facilitates the welding of the two.

[0054] In the second embodiment, the outer periphery of the explosion-proof valve 70 is a groove structure 78 with an opening facing the first lower plastic 21, the outer side wall of the groove structure 78 is welded with the cover plate body 10, and the groove structure 78 constitutes a clamping portion. The first lower plastic 21 has a first protruding portion 213 extending into the groove structure 78 on the side facing the cover plate body 10, and the first protruding portion 213 constitutes a matching portion. The first protruding portion 213 extends into the groove structure 78 to complete the clamping of the clamping portion and the matching portion, thereby limiting the rotation of the first lower plastic 21. The groove structure 78 includes a circle of grooves 74, and the first protruding portion 213 is a circle of protruding structures embedded in the circle of grooves 74. The first protruding portion 213 is clamped in the groove 74 and is limited in the whole circumferential direction.

[0055] In the first and second embodiments, the explosion-proof valve 70 further includes a weak portion (score) 79, the thickness of the weak portion 79 is less than the thickness of other parts of the explosion-proof valve 70, see Figure 10The weak part 79 can be a discontinuous structure or a continuous ring structure. The weak part 79 is located at the weakest area of the explosion-proof valve 70. When the pressure inside the battery cell 100 exceeds a certain threshold, the weak part 79 will break, and the pressure inside the battery cell 100 will be released from the broken part. The second protruding part 72 or the groove structure 78 is arranged around the weak part 79. The groove 74 in the second protruding part 72 or the groove structure 78 can simultaneously absorb the heat-affected deformation of the welding of the explosion-proof valve 70 and the cover plate body 10, and simultaneously reduce the influence on the weak part 79.

[0056] In the first and second embodiments, the first lower plastic 21 has a third protruding part 214 protruding towards the cover plate body 10 on the side facing the cover plate body 10. The third protruding part 214 is located between the first protruding part 213 and the second lower plastic 22 and abuts against the cover plate body 10 to support the cover plate body 10 and the first lower plastic 21. In the direction from the cover plate body 10 to the electrode assembly, the part of the first lower plastic 21 overlapping the explosion-proof valve 70 has a plurality of exhaust holes 82 for exhaust through the first lower plastic 21. The first protruding part 213 surrounds the plurality of exhaust holes 82. The first protruding part 213 and the third protruding part 214 support the first lower plastic 21 at the exhaust holes 82, avoiding the exhaust holes 82 from contacting the explosion-proof valve and affecting the exhaust.

[0057] Figure 17 An exploded view of the battery cell 100 according to the third embodiment of the present application is shown. Figure 18 A front view of the battery cell 100 according to the third embodiment of the present application is shown, as well as a cross-sectional view taken along the A-A line of the front view. Although the shape matching structure at the explosion-proof valve 70 is not shown, it can be understood that the third embodiment includes the content of the first or second embodiment.

[0058] On the basis of the first and second embodiments, the third embodiment further provides 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 extending end 42 extending from the first electrode assembly 51 and the second electrode assembly 52. The extending end 42 is 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.

[0059] Figure 19 A top view of the cover plate assembly according to the fourth embodiment of the present application is shown, as well as a cross-sectional view taken along the D-D line of the top view, a cross-sectional view taken along the E-E line of the top view, and an enlarged view of the area F in the cross-sectional view. Although the shape matching structure at the explosion-proof valve 70 is not shown, it can be understood that the fourth embodiment includes the content of the first or second embodiment.

[0060] On the basis of 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 passing through the liquid injection boss 12, and a groove 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 groove 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 passing electrolyte during liquid injection. The fourth embodiment further fixes the first lower plastic 21 at the position of the liquid injection hole 14, avoiding the first lower plastic from being skewed and twisted.

[0061] Figure 20 A top view of a cover plate assembly according to a fifth embodiment of the present application, a sectional view taken along the U-U line of the top view, and an enlarged view of the V area in the sectional view are shown. Although the shape fitting structure at the explosion-proof valve 70 is not shown, it is understood that the fifth embodiment includes the content of the first or second embodiment.

[0062] On the basis of the first or second embodiment, in the fifth embodiment, a side of the cover plate body 10 facing the electrode assembly has a recessed portion 18 recessed away from the lower plastics 21, 22, one of the first lower plastic 21 and the second lower plastic 22 has a protrusion portion 220 protruding towards the cover plate body 10, and the other of the first lower plastic 21 and the second lower plastic 22 has a lower plastic through hole 216, the protrusion portion 220 passing through the lower plastic through hole 216 and extending into the recessed portion 18, fixedly connecting the first lower plastic 21 and the second lower plastic 22, and simultaneously locating the first lower plastic 21 and the second lower plastic 22 at the cover plate body 10, further preventing the first lower plastic 21 and the second lower plastic 22 from rotating.

[0063] Figure 21 A top view of a side of a cover plate assembly facing an electrode assembly according to a sixth embodiment of the present application, a sectional view taken along the Y-Y line of the top view, and an enlarged view of the Z area in the sectional view are shown. Although the shape fitting structure at the explosion-proof valve 70 is not shown, it is understood that the sixth embodiment includes the content of the first or second embodiment.

[0064] On the basis of the first or second embodiment, in the sixth embodiment, the first adapter piece 61 is connected to the first lower plastic 21 in a pin-hole fitting manner at a position deviated from the first pole post 31, to further prevent the first lower plastic 21 from rotating. One of the first lower plastic 21 and the first adapter piece 61 is provided with a pin 218, and the other of the first lower plastic 21 and the first adapter piece 61 is provided with a hole 616, the pin 218 being inserted into the hole 616 to form a pin-hole fitting, the hole 616 being arranged between the first pole post 31 and the first lead 612 along a radial direction of the first pole post 31.

[0065] The cooperation between the second adapter piece 62 and the second lower plastic is similar to the cooperation between the first lower plastic 21 and the first adapter piece 61, and the second adapter piece 62 is also positioned in the pin hole cooperation manner with the second lower plastic 22 at the position deviated from the second pole post 32, so as to further prevent the second lower plastic 22 from rotating around the second pole post 32.

[0066] The embodiments of the present application can improve the sealing around the first pole post 31 and the second pole post 32, and improve the safety and air tightness of the whole battery cell 100 by fixing the first lower plastic 21 and the second lower plastic 22 and avoiding the torsion / rotation of the first lower plastic 21 and the second lower plastic 22. In the manufacturing process of the battery cell 100, the first lower plastic 21 and the second lower plastic 22 can be easily heat-fused with the Mylar film 80. After the cover plate assembly is assembled with the electrode assemblies 51 and 52, the first lower plastic 21 and the second lower plastic 22 are not rotated but centered in the process of being put into the shell 102, which is convenient for guiding, the Mylar film 80 will not rotate with the first lower plastic 21 and the second lower plastic 22, the Mylar film 80 is less scratched by the shell 102, and the safety performance of the battery cell 100 is improved. The positions of the first lower plastic 21 and the second lower plastic 22 are stable, and no impurity particles are generated due to shaking and friction in the supply chain, transportation and production processes, which can cause the risk of corrosion of the battery cell 100. The embodiments of the present application improve the safety performance of the battery.

[0067] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cover assembly, characterized by The cover plate assembly comprises: a cover plate body; a lower plastic, comprising a first lower plastic and a second lower plastic arranged on a first side of the cover plate body facing the electrode assembly; a first pole post passing through the cover plate body and the first lower plastic; a second pole post passing through the cover plate body and the second lower plastic; an explosion-proof valve fixed on the cover plate body, the explosion-proof valve having a clamping portion with one of the lower plastics and a matching portion with the other one of the lower plastics, the rotation of the first lower plastic being limited by the clamping of the clamping portion and the matching portion.

2. The cover plate assembly according to claim 1, wherein the first lower plastic has a first protruding portion protruding towards the cover plate body on a side facing the cover plate body, the first protruding portion constituting the matching portion, the explosion-proof valve has a second protruding portion protruding away from the cover plate body on the first side, the second protruding portion constituting the clamping portion, the first protruding portion and the second protruding portion abut to limit the rotation of the first lower plastic.

3. The cover plate assembly according to claim 2, wherein the first protruding portion and the second protruding portion are both a ring of protruding structures.

4. The cover plate assembly of claim 3, wherein, the first protruding portion is arranged peripherally to the second protruding portion.

5. The cover plate assembly according to claim 3, wherein the second protruding portion is provided with a ring of grooves arranged along the extension path of the second protruding portion, the openings of the grooves facing away from the first lower plastic.

6. The cover plate assembly according to claim 4, wherein the explosion-proof valve comprises an overlapping portion surrounding the second protruding portion, the overlapping portion overlapping on a side of the first protruding portion facing the cover plate body.

7. The cover plate assembly according to claim 1, wherein the outer periphery of the explosion-proof valve is a groove structure with openings facing the first lower plastic, the groove structure constituting the clamping portion, the first lower plastic has a first protruding portion protruding towards the cover plate body on a side facing the cover plate body, the first protruding portion extending into the groove structure and constituting the matching portion.

8. The cover plate assembly according to claim 7, wherein the groove structure comprises a ring of grooves, the first protruding portion being a ring of protruding structures embedded in the ring of grooves.

9. The cover plate assembly of any one of claims 2 to 8, wherein, the explosion-proof valve further comprises a weak portion having a thickness smaller than that of other portions of the explosion-proof valve, the second protruding portion or the groove structure being arranged around the weak portion; and / or the first lower plastic has a third protruding portion protruding towards the cover plate body on a side facing the cover plate body, the third protruding portion being located between the first protruding portion and the second lower plastic and abutting against the cover plate body.

10. An electric cell characterized by The battery pack comprises: a housing; a cover plate assembly according to any one of claims 1-9, the cover plate assembly covering the housing and defining a containing cavity with the housing; an electrode assembly contained in the containing cavity, a first tab of the electrode assembly being electrically connected to the first pole post, and a second tab of the electrode assembly being electrically connected to the second pole post.

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