Cover plate assembly and battery cell

Abstract

The present application relates to the technical field of batteries, and particularly relates to a cover plate assembly and a battery cell. The cover plate assembly comprises: a terminal post; a cover plate main body provided with a mounting hole for mounting the terminal post; and a sealing member arranged between the cover plate main body and the terminal post, wherein the dimension of the sealing member in a first direction is H; the cover plate main body is press-fitted with the sealing member in the first direction, such that a first compression amount L1 is formed on the sealing member; and a first compression ratio K1 of the sealing member is defined as K1=L1 / H, where 15%≤K1≤55%. The present application can avoid the situation of easy air leakage due to poor sealing performance caused by insufficient press-fitting strength between the sealing member and the cover plate main body, or avoid the situation of sealing failure due to easy damage to the sealing member when the battery cell bears a preset pressure caused by excessive press-fitting strength, thereby ensuring the effectiveness, sealing reliability and service life of the sealing member.

Description

Cover plate assembly and battery cell

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411366724.8, filed on September 29, 2024, and entitled "Cover plate assembly and battery cell", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a cover plate assembly and a battery cell. BACKGROUND

[0004] With the increasing maturity of lithium ion battery technology, power batteries are widely used in electric vehicles as new batteries, and the performance and safety requirements of power batteries are increasingly high.

[0005] The cover plate and the shell of the battery structure are sealingly connected to protect the bare battery cell in the shell. The cover plate includes an aluminum plate, a pole, and a sealing ring. The sealing ring is press-fitted at the connection between the aluminum plate and the pole to serve as a seal between the inside and outside of the battery. Once the sealing ring fails, the sealing and insulation performance of the battery will be reduced. Therefore, the service life and reliability of the sealing ring can ensure the reliability of the internal sealing of the battery and the cycle life of the battery. Since the sealing ring is an elastic member, air leakage may occur at the position where the sealing ring is arranged, resulting in detection failure and affecting the quality and yield of the product.

[0006] SUMMARY

[0007] Therefore, the purpose of the present application is to provide a cover plate assembly and a battery cell to solve the technical problem that the sealing ring in the existing battery cover plate assembly is prone to failure, resulting in air leakage at the position where the sealing ring is arranged, detection failure, and affecting the quality and yield of the product.

[0008] To achieve the above purpose, the technical solutions adopted by the embodiments of the present application are as follows:

[0009] The present application provides a cover plate assembly, comprising:

[0010] a pole;

[0011] a cover plate body having a mounting hole for mounting the pole;

[0012] a sealing member arranged between the cover plate body and the pole; the sealing member has a size H in a first direction, and the cover plate body is press-fitted with the sealing member in the first direction, so that the sealing member has a first compression amount L1, and the first compression rate K1 of the sealing member is L1 / H, 15%≤K1≤55%.

[0013] In the technical solution, further, in the first direction, the distance between the end of the cover plate body being press-contacted with the sealing element and the end of the cover plate body being away from the sealing element is X, X≥0.7mm.

[0014] In any of the above technical solutions, further, after the cover plate body is press-contacted with the sealing element, the size of the sealing element being in contact with the cover plate body in the second direction is B, 0.8mm≤B≤3mm.

[0015] In any of the above technical solutions, further, the cover plate assembly further comprises:

[0016] a first insulation element at least partially covering the side wall of the pole in the circumferential direction, and part of the first insulation element extending into the mounting hole and being in abutment with the sealing element in the first direction, so that the sealing element is formed with a second compression amount L2, 0mm≤L2≤0.8mm.

[0017] In any of the above technical solutions, further, the second compression rate K2 of the sealing element is K2=L2 / H, 0%≤K2≤50%.

[0018] In any of the above technical solutions, further, the cover plate assembly further comprises:

[0019] a support element formed in an annular structure, the support element being embedded between the first insulation element and the pole, and part of the first insulation element being clamped between the support element and the cover plate body.

[0020] In any of the above technical solutions, further, the support element is a weldable element, and the support element is welded with the pole.

[0021] In any of the above technical solutions, further, a pressure relief hole is formed in the cover plate body; and the cover plate assembly further comprises:

[0022] a pressure relief element installed in the pressure relief hole, and the opening pressure of the pressure relief element is P, P≤1.2MPa.

[0023] In any of the above technical solutions, further, the side wall of the pole is formed with a protruding limiting boss;

[0024] In the first direction, the sealing element is clamped between the limiting boss and the cover plate body.

[0025] The application also provides an electric core comprising the cover plate assembly according to any of the above technical solutions.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] The cover plate assembly provided in the present application comprises:

[0028] a pole column; a cover plate body provided with a mounting hole for mounting the pole column;

[0029] a sealing element arranged between the cover plate body and the pole column; the sealing element has a size H in a first direction, the cover plate body is pressed against the sealing element in the first direction, so that the sealing element has a first compression amount L1, and a first compression rate K1 of the sealing element is L1 / H, 15%≤K1≤55%.

[0030] The cover plate assembly provided in the present application limits the ratio between the first compression amount L1 of the sealing element caused by the cover plate body in the first direction and the size H of the sealing element in the first direction after the sealing element is pressed against the cover plate body, i.e. limits the range of the first compression rate K1, avoids the situation that the sealing performance between the sealing element and the cover plate body is poor due to insufficient pressing strength, or avoids the situation that the sealing element is damaged and the sealing fails due to excessive pressing strength when the battery cell bears a certain pressure, thereby ensuring the effectiveness and service life of the sealing element, and further improving the product quality and yield of the battery cell.

[0031] The battery cell provided in the present application comprises the cover plate assembly described above, and thus has all the beneficial effects of the cover plate assembly described above, which will not be described herein again. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0033] FIG. 1 is a structural schematic view of the cover plate assembly provided in the embodiments of the present application;

[0034] FIG. 2 is a structural schematic view of the cover plate assembly provided in the embodiments of the present application from another perspective;

[0035] FIG. 3 is a structural sectional view of the cover plate assembly provided in the embodiments of the present application;

[0036] FIG. 4 is an enlarged structural schematic view of A in FIG. 3;

[0037] FIG. 5 is an exploded structural view of the cover plate assembly provided in the embodiments of the present application;

[0038] FIG. 6 is a first structural schematic view of the pole column in the cover plate assembly provided in the embodiments of the present application;

[0039] Fig. 7 is a second structure diagram of the pole in the cover plate assembly provided by the embodiment of the present application;

[0040] Fig. 8 is a third structure diagram of the pole in the cover plate assembly provided by the embodiment of the present application;

[0041] Fig. 9 is a first structure diagram of the sealing member in the cover plate assembly provided by the embodiment of the present application;

[0042] Fig. 10 is a second structure diagram of the sealing member in the cover plate assembly provided by the embodiment of the present application;

[0043] Fig. 11 is a third structure diagram of the sealing member in the cover plate assembly provided by the embodiment of the present application.

[0044] Fig. 11 is a third structure diagram of the sealing member in the cover plate assembly provided by the embodiment of the present application. DETAILED DESCRIPTION

[0045] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0046] The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0047] Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0048] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0050] The cover plate assembly and the battery cell according to the embodiments of the present application are described below with reference to FIGS. 1-11.

[0051] As shown in FIGS. 1-3 and 5, the cover plate body 20 is provided with a mounting hole 21, which is a through hole structure penetrating the cover plate body 20, and the pole 10 is assembled with the cover plate through the mounting hole 21. The cover plate body 20 can be a sheet structure with a rectangular or circular shape, for example, the cover plate body 20 can be a rectangular aluminum sheet.

[0052] As shown in FIGS. 3 and 4, the sealing member 30 is assembled between the cover plate body 20 and the pole 10 to avoid a gap between the cover plate body 20 and the pole 10, so as to isolate the inside of the battery cell from the outside and ensure normal use of the battery cell. Specifically, in the thickness direction of the cover plate body 20, part of the sealing member 30 is clamped between the cover plate body 20 and the limiting boss 11 described below; the remaining part of the sealing member 30 extends towards the outside of the battery cell to be embedded in the area surrounded by the hole wall of the mounting hole 21 and the circumferential side wall of the pole 10. The sealing member 30 is a whole elastic member, for example, a sealing ring, and is formed in an annular structure to cover the side wall of the pole 10 in the circumferential direction. The sealing member 30 can ensure that there is no gap between the sealing member 30 and the pole 10 by utilizing the elasticity of the sealing member 30 itself, so as to avoid fluid passing between the side wall of the pole 10 and the inner wall of the sealing member 30.

[0053] As shown in FIGS. 1-8, the side wall of the pole 10 is formed with a protruding limiting boss 11, and the sealing member 30 is clamped between the limiting boss 11 and the cover plate body 20 in the first direction D1. The limiting boss 11 is preferably a closed annular structure and is arranged on the side of the pole 10 axially facing the inside of the battery cell.

[0054] It should be noted that the number of poles 10 can be one or more, and the mounting hole 21 is arranged one by one corresponding to the pole 10. When the number of poles 10 is one, at least two cover plate assemblies are mounted on the battery cell; when the number of poles 10 is multiple, at least part of the multiple poles 10 are positive poles 10, and the remaining part of the poles 10 are negative poles 10.

[0055] Optionally, as shown in FIGS. 6-8, the pole column 10 is formed as a block structure in a circular or rectangular shape, or a combination of circular and rectangular block structures, but the shape of the pole column 10 is not limited to this, and can also be an elliptical shape, as long as it can meet the function of conducting current of the battery cell.

[0056] Further, optionally, as shown in FIGS. 9-11, the sealing member 30 can be formed as a ring structure in a circular or rectangular shape, and the shape of the sealing member 30 is preferably adapted to the outer wall of the position where the sealing member 30 is arranged in the circumferential direction of the pole column 10, i.e., when the position where the pole column 10 is mounted with the sealing member 30 is circular in the cross section perpendicular to the axial direction, a circular sealing member 30 is selected to cooperate with it, so that the inner wall of the entire sealing member 30 can be tightly fitted with the side wall of the pole column 10, thereby improving the sealing between the sealing member 30 and the pole column 10.

[0057] It should be noted that, as shown in FIGS. 10 and 11, when the sealing member 30 is a polygonal structure, an arc-shaped chamfer can be provided at the corner between the two adjacent sides, as long as the sealing property of the cover plate assembly is met. It should be further noted that the shape of the sealing member 30 is not limited to this, and can also be a racetrack-shaped ring structure, as long as reliable sealing with the pole column 10 can be achieved.

[0058] As shown in FIGS. 3 and 4, the size of the sealing member 30 in the first direction D1 is H, the first direction D1 is the thickness direction of the cover plate body 20, i.e., the axial direction of the pole column 10; the cover plate body 20 is press-bonded with the sealing member 30 in the first direction D1, and due to the elasticity of the sealing member 30, the sealing member 30 deforms when it is press-bonded with the cover plate body 20, so that the sealing member 30 forms a first compression amount L1 under the extrusion of the cover plate body 20, and the first compression rate K1 of the sealing member 30 is L1 / H, and the preferred range of the first compression rate K1 is 15%≤K1≤55%. If the first compression amount is too small, it cannot guarantee that the cover plate body 20 and the sealing member 30 are tightly and reliably assembled, and the insufficient press-fit strength between the cover plate body 20 and the sealing member 30 can easily lead to poor sealing between the sealing member 30 and the cover plate body 20, thereby easily causing air leakage between the cover plate body 20 and the sealing member 30. If the first compression amount is too large, the initial first compression amount K1 will increase under the condition of increased pressure inside the battery cell, which can easily cause the sealing member 30 to fail, such as cracking, thereby reducing the sealing property and service life of the sealing member 30 due to excessive press-fit strength, and further causing the battery cell product to fail the helium test and the production yield to be low.

[0059] The first compression rate K1 is 15%≤K1≤55%, under which the problem of sealing failure caused by insufficient or excessive compression strength between the cover plate body 20 and the sealing element 30 can be effectively avoided. Since the battery cell also generates heat during operation, experiments are conducted to determine whether the first compression rate within the range of 15%≤K1≤55% under different temperatures can ensure the effectiveness of the sealing element 30. The experimental parameters are shown in Tables 1 and 2 below:

[0060] Table 1

[0061] Table 2 Note: "Helium detection NG" in Tables 1 and 2 means that the detection is unqualified, and "helium detection OK" means that the detection is qualified.

[0062] As can be seen from Tables 1 and 2, in the examples 1-1 to 1-3 of Table 1 and the examples 2-1 to 2-3 of Table 2, the first compression amount K1 is less than 15% whether in a normal temperature state (i.e. room temperature) or in a temperature state of 120°C. This causes the cover plate body 20 and the sealing element 30 to be not tightly assembled, and the insufficient compression strength between the cover plate body 20 and the sealing element 30 will directly lead to unqualified helium detection, or the situation that the pole 10 leaks air when being pressurized to a preset pressure, resulting in a decrease in the yield.

[0063] In the examples 1-13 to 1-16 of Table 1 and the examples 2-13 to 2-16 of Table 2, the first compression amount K1 is greater than 55%. Although the cover plate body 20 and the sealing element 30 are tightly and reliably assembled, through experiments of pressurizing the pole 10 position to 1.2 MPa, baking at 85°C for 1000h, and applying a force of 800N to the pole 10 in the first direction D1 for 50,000 times to simulate the working conditions of the battery cell, when the battery cell is detected in this way, the examples 1-13 to 1-16 of Table 1 and the examples 2-13 to 2-16 of Table 2 all have the problem of unqualified helium detection and cracking of the sealing ring after baking at 85°C for 1000h or after the pole 10 bears a force of 800N in the first direction D1 for 50,000 times.

[0064] In the examples 1-4 to 1-12 of Table 1 and the examples 2-4 to 2-12 of Table 2, under the condition of pressurizing the pole 10 position to 1.2 MPa, after baking at 85°C for 1000h, under the condition of pressurizing the pole 10 position to 1.2 MPa, and under the condition of applying a force of 800N to the pole 10 in the first direction D1 for 50,000 times, there is no air leakage and the helium detection is qualified.

[0065] Therefore, the defined condition that the first compression rate K1 is 15%≤K1≤55% can guarantee the sealing effectiveness and reliability of the sealing member 30, so as to meet the sealing requirement of the cover plate assembly to the battery cell shell and improve the yield of the battery cell.

[0066] Further, as shown in FIG. 3 and FIG. 4, after the cover plate body 20 is pressure-bonded with the sealing member 30, the size of the sealing member 30 in contact with the cover plate body 20 in the second direction D2 is B, and the size B is too small to easily cause the sealing reliability to decrease, and the size B is too large to cause the corresponding size of the sealing member 30 in the second direction D2 to be thickened, so that the cost and weight are increased.

[0067] In a preferred embodiment, 0.8mm≤B≤3mm, wherein the second direction D2 is the length direction of the rectangular cover plate body 20.

[0068] The second direction D2 is perpendicular to the first direction D1.

[0069] In order to verify whether the defined condition that 0.8mm≤B≤3mm can improve the sealing under the condition that the first compression rate K1 is 15%≤K1≤55%, the following experiments are performed to verify whether the defined condition that 0.8mm≤B≤3mm can guarantee the effectiveness of the sealing member 30, and the experimental parameters are shown in Table 3 as follows:

[0070] Table 3 Note: “Helium detection NG” in Table 3 means that the detection is unqualified, and “helium detection OK” means that the detection is qualified.

[0071] As shown in Table 3, in the case that the first compression rate K is 35%, in the embodiment 3-1 to the embodiment 3-9 of Table 3, the size of B in the embodiment 3-1 of Table 3 is 0.5mm, which is less than the preferred range of B≥0.8mm, and because the size of the sealing member 30 in contact with the cover plate body 20 in the second direction D2 is too small, the pole 10 is easily caused to fail to seal when the pole 10 is subjected to high-intensity impact in the first direction D1, so that the helium detection is unqualified; and in the embodiment 3-2 to the embodiment 3-9 of Table 3, the size of B is greater than or equal to 0.8mm, and because the sealing member 30 has sufficient contact area with the cover plate body 20 in the second direction D2, the pole 10 can effectively seal after being subjected to 10 times of 1200N force in the first direction D1 (in the case of high-intensity impact) and after being subjected to 5 million times of 800N force (in the case of meeting the test conditions of the working environment and the service life), so that the helium detection is qualified, but the embodiment 3-9 of Table 3 can guarantee the helium detection to be qualified but causes the cost to be significantly increased, so that the defined condition that 0.8mm≤B≤3mm can meet the requirements of the sealing and the economy at the same time.

[0072] In addition, as shown in FIG. 3 and FIG. 4, the part of the cover plate body 20 for being in pressure contact with the sealing member 30 can form support for the sealing member 30 in the first direction D1, as shown in FIG. 4, the distance between the end of the cover plate body 20 in pressure contact with the sealing member 30 and the end of the cover plate body 20 away from the sealing member 30 in the first direction D1 is X, X≥0.7mm, that is, the thickness of the part of the cover plate body 20 for being in pressure contact with the sealing member 30 is not less than 0.7mm, so as to avoid the situation that the sealing reliability between the cover plate body 20 and the sealing member 30 is reduced due to the deformation of the cover plate body 20, thereby further improving the sealing reliability between the cover plate body 20 and the sealing member 30.

[0073] Further, as shown in FIG. 1 to FIG. 5, the cover plate assembly further comprises a first insulating member 40, the first insulating member 40 at least partially covers the side wall of the pole 10 in the circumferential direction, the first insulating member 40 can be made of plastic material to play an insulating role, the first insulating member 40 is formed in a ring structure and is arranged on the side of the cover plate body 20 facing the outside of the battery cell, part of the first insulating member 40 extends into the mounting hole 21 and abuts against the sealing member 30 in the first direction D1, so that the sealing member 30 is formed with a second compression amount L2, wherein 0mm≤L2≤0.8mm, so as to avoid that the second compression amount is too large to affect the sealing between the sealing member 30 and the pole 10. It should be noted that when L2 is 0, that is, the sealing member 30 does not deform obviously in the first direction D1.

[0074] Preferably, the second compression rate K2 of the sealing member 30 is L2 / H, 0%≤K2≤50%, so as to avoid the situation that the pressure is too large due to the too large second compression rate and exceeds the tolerance strength of the first insulating member 40, thereby causing the first insulating member 40 to crack, or the problem of low sealing reliability caused by the non-contact between the first insulating member 40 and the sealing member 30.

[0075] The effectiveness of the limitation condition 0%≤K2≤50% is tested as follows, and the experimental parameters are shown in Table 4:

[0076] Table 4 Note: "helium detection NG" in Table 4 means unqualified detection, and "helium detection OK" means qualified detection.

[0077] As can be seen from Table 4, in the embodiments 4-1 to 4-9, K1 is within the range of 15%≤K1≤55%, but in the embodiments 4-7 to 4-9, due to the too large parameter of K2, the first insulating part 40 is cracked, which has the risk of insulation failure, resulting in unqualified helium detection; and in the embodiments 4-1 to 4-6 of Table 4, K2 is within the range of 0%≤K2≤50%, the first insulating part 40 is not cracked, so that the first insulating part 40 has good insulation, ensuring that the helium detection is qualified.

[0078] Further, as shown in FIGS. 1 to 3 and 5, the cover plate assembly further comprises a second insulating part 50, which is arranged on the side of the cover plate body 20 facing the inside of the battery cell. The second insulating part 50 is formed in a structure matching the shape of the cover plate body 20, and is made of an insulating material such as plastic, so as to ensure the insulation between the cover plate body 20 and the inside of the battery cell.

[0079] In addition, as shown in FIGS. 1 to 5, the cover plate assembly further comprises a support part 60 formed in a ring structure, which is embedded between the first insulating part 40 and the pole 10, and part of the first insulating part 40 is clamped between the support part 60 and the cover plate body 20, so that the first insulating part 40 is tightly attached to the surface of the cover plate body 20 facing the outside of the battery cell, improving the assembly reliability.

[0080] Preferably, the support part 60 is a weldable part, i.e., the support part 60 is formed of a weldable material, for example, the support part 60 can be made of aluminum alloy, copper or ceramic material, so that the support part 60 can be welded to the pole 10.

[0081] As shown in FIG. 5, the cover plate body 20 is provided with a pressure relief hole 22, which is a through hole structure penetrating through the cover plate body 20; the cover plate assembly further comprises a pressure relief part 70 mounted on the pressure relief hole 22. When the battery cell has an abnormal condition, the pressure inside the battery cell will increase. When the pressure increases to a preset pressure, the pressure relief part 70 will open to allow the inside of the battery cell to communicate with the outside through the pressure relief hole 22, thereby releasing the pressure and avoiding explosion and other dangers. Preferably, the opening pressure of the pressure relief part 70 is P, P≤1.2MPa, so as to meet the working requirements of the battery cell. The pressure relief part 70 can be an explosion-proof valve.

[0082] Further, as shown in FIG. 5, the cover plate assembly further comprises a protection part 71 mounted on the pressure relief hole 22 and arranged on the side of the cover plate body 20 facing the outside of the battery cell, so as to protect the pressure relief part 70 and avoid the impact of the components outside the battery cell on the pressure relief part 70, which may cause the pressure relief part 70 to open prematurely, thereby failing to effectively protect the battery cell.

[0083] In addition, as shown in FIGS. 1-3 and 5, the cover plate body 20 is further provided with a liquid injection hole 23 formed as a through hole structure penetrating through the cover plate body 20, and after the cover plate body 20 and the shell of the battery cell are assembled, electrolyte can be injected into the battery cell through the liquid injection hole 23. After the injection is completed, the liquid injection hole 23 is plugged with a sealing nail.

[0084] According to the cover plate assembly provided in the present application, by limiting the ratio between the first compression amount L1 of the sealing member caused by the cover plate body in the first direction and the size H of the sealing member in the first direction after the cover plate body is press-fitted with the sealing member, i.e. limiting the range of the first compression rate K1, the situation that the sealing member and the cover plate body have poor sealing and are prone to air leakage due to insufficient press-fitting strength, or the situation that the sealing member is damaged and the sealing fails due to excessive press-fitting strength when the battery cell bears the preset pressure, is avoided, so as to ensure the effectiveness and service life of the sealing member.

[0085] According to the battery cell provided in the present application, the sealing member can be reliably press-fitted with the cover plate body and will not be damaged under the preset pressure, so as to ensure the effectiveness, sealing reliability and service life of the sealing member, and further improve the product quality and yield of the battery cell.

[0086] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. Industrial applicability

[0087] The cover plate assembly and the battery cell provided in the present application can avoid the situation that the sealing member and the cover plate body have poor sealing and are prone to air leakage due to insufficient press-fitting strength, or the situation that the sealing member is damaged and the sealing fails due to excessive press-fitting strength when the battery cell bears the preset pressure, so as to ensure the effectiveness, sealing reliability and service life of the sealing member.

Claims

1. A cover assembly, characterized by The cover plate assembly comprises: a pole; a cover plate body provided with a mounting hole for mounting the pole; a sealing element arranged between the cover plate body and the pole; the sealing element has a size H in a first direction, the cover plate body is pressed against the sealing element in the first direction, so that the sealing element has a first compression amount L1, the first compression rate K1 of the sealing element is L1 / H, and 15%≤K1≤55%.

2. The cover plate assembly of claim 1, wherein, In the first direction, the distance between the end of the cover plate body pressed against the sealing element and the end of the cover plate body away from the sealing element is X, and X≥0.7mm.

3. The cover plate assembly of claim 1, wherein, After the cover plate body is pressed against the sealing element, the size of the sealing element in contact with the cover plate body in a second direction is B, and 0.8mm≤B≤3mm.

4. The cover plate assembly of claim 1, wherein, The cover plate assembly further comprises: a first insulating element at least partially covering the side wall of the pole in the circumferential direction, and part of the first insulating element extends into the mounting hole and abuts against the sealing element in the first direction, so that the sealing element has a second compression amount L2, and 0mm≤L2≤0.8mm.

5. The cover plate assembly of claim 4, wherein, The second compression rate K2 of the sealing element is L2 / H, and 0%≤K2≤50%.

6. The cover plate assembly of claim 4, wherein, The cover plate assembly further comprises: a support element formed in an annular structure, the support element is embedded between the first insulating element and the pole, and part of the first insulating element is clamped between the support element and the cover plate body.

7. The cover plate assembly of claim 6, wherein, The support element is a weldable element, and the support element is welded to the pole.

8. The cover plate assembly of claim 1, wherein, The cover plate body is provided with a pressure relief hole; the cover plate assembly further comprises: a pressure relief element installed in the pressure relief hole; the opening pressure of the pressure relief element is P, and P≤1.2MPa.

9. The cover plate assembly of claim 1, wherein, The side wall of the pole is formed with a protruding limiting boss; In the first direction, the sealing element is clamped between the limiting boss and the cover plate body.

10. An electric cell characterized by The cover plate assembly comprises the cover plate assembly according to any one of claims 1 to 9.

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