Cover plate assembly and battery cell comprising same

Abstract

The utility model relates to the field of batteries, and discloses a cover plate assembly and a battery cell comprising the same, the battery cell comprises a shell, a cover plate assembly and an electrode assembly, the cover plate assembly covers the shell to form an accommodating cavity with the shell to accommodate the electrode assembly, the cover plate assembly comprises a cover plate, a pole and a first sealing ring, the cover plate comprises a cover plate body and a lower insulating part, and the lower insulating part is arranged on the cover plate body. The columnar body of the pole penetrates through the pole through hole of the cover plate, the connecting plate is electrically connected with the tab of the electrode assembly, the lower insulating part is located between the cover plate body and the connecting plate, and the pole through hole comprises a second through hole of the lower insulating part; at least one groove in the thickness direction is formed in the edge portion of the second through hole, the surface, facing the lower insulating part, of the cover plate body and the surface, facing the lower insulating part, of the connecting plate, the groove is communicated with the second through hole, the edge portion is sleeved with the first sealing ring, the end portion of the first sealing ring extends into the groove, and the first sealing ring makes contact with the surface of the lower insulating part and the surface of the connecting plate. The electrolyte is prevented from permeating along the surface of the lower insulating part to electrically conduct the cover plate body and the connecting plate.

Description

Technical Field

[0001] The utility model relates to the field of batteries, in particular to a cover plate assembly of a battery cell. Background Art

[0002] like Figure 1 In current battery cells, the negative electrode column 2' of the cover assembly 100' is provided with an upper plastic 6'. The upper plastic 6' is typically made of an insulating material with a resistance of 500MΩ or higher. This ensures good insulation between the cover body 1' and the connector 9' of the cover assembly 100', preventing corrosion of the cover body 1'. The cover body is typically made of aluminum.

[0003] In order to meet the sealing requirements, an annular sealing ring 5' with an L-shaped cross section is usually installed around the pole 2'. The compressed part of the L-shaped sealing ring 5' will be compressed into the cavity 8' area formed by the cover body 1', the connecting plate 21' of the pole 2' and the lower plastic 3', thereby achieving sealing.

[0004] During the battery cell filling and formation stages, the battery cell is usually in an upright state, so that the side of the cover assembly 100' facing the electrode assembly 400' in the battery cell is completely immersed in the electrolyte. The cavity 8' may not be filled by the L-shaped sealing ring 5', so the electrolyte may flow into the remaining part of the cavity 8'. Under certain circumstances, it will electrically conduct the connecting plate 21' between the cover body 1' and the pole 2', short-circuit the upper plastic 6' serving as the insulation resistor, and reduce the resistance between the connector 9' and the cover body 1', which may easily cause abnormal voltage on the positive side of the entire battery cell. The cover body 1' will also be at a certain risk of corrosion, affecting the overall safety of the battery cell. Utility Model Content

[0005] The technical problem to be solved by the present invention is to overcome the defects in the prior art that electrolyte penetrates the electrically conductive cover plate body and the connecting plate, causing abnormal battery cell voltage and corrosion of the cover plate body, thereby affecting battery safety, and provide a cover plate assembly and a battery cell including the same.

[0006] The utility model solves the above technical problems through the following technical solutions:

[0007] A cover plate assembly, comprising:

[0008] A cover plate having a pole through hole along its thickness direction; the cover plate comprises a cover plate body and a lower insulating member located on one side of the cover plate body in the thickness direction; the pole through hole comprises a first through hole formed in the cover plate body and a second through hole formed in the lower insulating member, the first through hole and the second through hole being coaxial;

[0009] The pole comprises a columnar body and a connecting plate; the columnar body passes through the pole through hole, and the connecting plate is located on a side of the lower insulating member away from the cover body;

[0010] At least one groove along the thickness direction is formed in the edge of the second through hole, the surface of the cover plate body facing the lower insulating member, and the surface of the connecting plate facing the lower insulating member, and the groove is connected to the second through hole;

[0011] The cover plate assembly also includes a first sealing ring, which is sleeved on the edge portion, and the end of the first sealing ring extends into the groove. The first sealing ring contacts the surface of the cover plate body facing the lower insulating member and contacts the surface of the connecting plate facing the lower insulating member.

[0012] In this embodiment, a groove is provided at a position corresponding to the second through-hole of the lower insulating member. The groove can be provided on the edges of the second through-hole of the lower insulating member along the thickness direction, on the surface of the cover body facing the lower insulating member, and on the surface of the connecting plate facing the lower insulating member. A first sealing ring is provided between the cover body and the lower insulating member and is sleeved on the edge of the second through-hole, with its end extending into the groove to form a seal at the groove. This can increase the electrolyte penetration path and reduce the risk of electrolyte penetrating along the surface of the lower insulating member to electrically connect the cover body and the connecting plate. On the one hand, this can reduce the risk of voltage anomalies caused by the electrolyte conducting between the cover body and the connecting plate; on the other hand, it can reduce the risk of electrolyte penetrating into the cover body and corroding the cover body, thereby improving the safety and reliability of the cover body.

[0013] Preferably, one of the grooves is a first groove formed on the surface of the lower insulating member facing the cover body or a second groove on the surface facing the connecting plate; the first sealing ring has an L-shaped portion with an L-shaped cross-section along the thickness direction, the L-portion is sleeved on the edge portion, and the part of the L-portion extending perpendicular to the thickness direction forms the end portion, and the end portion extends into the first groove or the second groove.

[0014] In this solution, a groove is provided on the lower insulator, eliminating the need for grooves on the cover plate body and connecting plate. This facilitates process centralization and reduces manufacturing costs. Furthermore, it avoids the potential for grooves to weaken the strength, flow capacity, and other performance characteristics of the cover plate body and connecting plate. The first sealing ring is provided with an L-shaped portion to seal within the first or second groove, resulting in a simple structure and easy processing.

[0015] Preferably, the number of the grooves is at least two, and the two grooves are a first groove formed on the surface of the lower insulating member facing the cover body and a second groove formed on the surface facing the connecting plate; the cross-section of the first sealing ring along the thickness direction is [-shaped, U-shaped or C-shaped, and the two ends of the first sealing ring on both sides along the thickness direction, one extends into the first groove, and the other extends into the second groove.

[0016] In this solution, two grooves are provided, one on each side of the lower insulator's thickness, to seal the lower insulator, enhancing reliability against electrolyte penetration. Both grooves are located on the lower insulator, eliminating the need for grooves on the cover plate and connecting plate. This facilitates process centralization and reduces manufacturing costs. Furthermore, it avoids the potential for grooves to weaken the cover plate and connecting plate's strength, current handling capacity, and other performance characteristics. The first sealing ring has a cross-section along its thickness of [-, U-, or C-shaped, resulting in a simple structure and easy processing.

[0017] Preferably, the cross section of the first sealing ring along the thickness direction is [-shaped, and the corners of the [-shaped are arc angles.

[0018] In this solution, the first sealing ring is arranged so as to be easy to process. When the first sealing ring is cast, the arc angle is provided to facilitate demoulding.

[0019] Preferably, the diameter of the first through hole is smaller than the diameter of the second through hole.

[0020] Preferably, the cover plate assembly further includes a second sealing ring, which is arranged in the pole through hole and sleeved on the outer side of the columnar body.

[0021] Preferably, the first sealing ring and the second sealing ring are arranged at intervals.

[0022] In this solution, such a configuration can, on the one hand, reduce the consumables of the first sealing ring and lower the cost; on the other hand, the interval space between the first sealing ring and the second sealing ring can be used as a deformation space for the components in the cover assembly. When the cover assembly is impacted or heated, the deformation of the components of the cover assembly can squeeze the space, thereby preventing the cover assembly from expanding outward and affecting other structures.

[0023] Preferably, the compression amount of the portion of the first sealing ring located in the groove is between 15% and 45%.

[0024] In this solution, such a configuration can, on the one hand, make the compression amount of the part of the first sealing ring located in the groove small enough, so that the force exerted by the part of the first sealing ring located in the groove on the cover body and the connecting plate is small enough, reducing the stress of the cover body and the connecting plate; on the other hand, the compression amount of the part of the first sealing ring located in the groove can be large enough, thereby ensuring that the sealing performance at the groove is good enough.

[0025] Preferably, the dimension of the groove along the thickness direction is between 0.04 mm and 0.06 mm.

[0026] In this solution, such a setting can, on the one hand, make the depth of the groove large enough to facilitate processing and ensure sufficient sealing when the first sealing ring is pressed into the groove; on the other hand, the depth of the groove can be small enough to avoid excessive weakening of the structural performance of the lower insulating part, the cover plate body or the connecting plate by setting the groove.

[0027] Preferably, the first sealing ring and the second through hole are interference fit.

[0028] In this solution, the second through hole of the lower insulating member and the first sealing ring are arranged in close contact, further improving the reliability of preventing electrolyte penetration.

[0029] Preferably, a cross-sectional profile of the second through hole along the thickness direction is in an arc shape convex toward the columnar body.

[0030] In this solution, the arc-shaped structure of the second through hole can, on the one hand, serve as a guide to facilitate the installation of the first sealing ring into the second through hole; on the other hand, it can increase the contact area between the surface of the second through hole and the surface of the first sealing ring, increase the friction force, and improve the sealing reliability of the first sealing ring; on the third hand, when the first sealing ring adopts a C-shaped or U-shaped structure, it is convenient for the first sealing ring and the second through hole to fit closely.

[0031] A battery cell, comprising:

[0032] case;

[0033] The cover plate assembly as described in any of the above technical solutions, wherein the cover plate assembly is disposed on the shell and defines a receiving cavity together with the shell, and the connecting plate is located on a side of the cover plate facing the receiving cavity along the thickness direction;

[0034] At least one electrode assembly is accommodated in the accommodating cavity, and the electrode tab of the electrode assembly is electrically connected to the connecting plate.

[0035] The positive progress effect of this utility model is:

[0036] A first sealing ring is provided between the cover body and the lower insulating member. The first sealing ring is sleeved on the edge of the second through hole of the lower insulating member, and the end portion extends into the groove connected to the second through hole to form a seal at the groove, which can increase the electrolyte penetration path and reduce the risk of the electrolyte penetrating along the surface of the lower insulating member to electrically connect the cover body and the connecting plate. On the one hand, the risk of voltage abnormality caused by the cover body and the connecting plate being connected by the electrolyte can be reduced; on the other hand, the risk of the electrolyte penetrating into the cover body and corroding the cover body can be reduced; thereby, the safety and reliability of the cover body can be improved.

[0037] Applying cover plate components with high safety and reliability to battery cells can improve the safety and reliability of the battery cells, thereby improving the safety and reliability of electricity use. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram of an existing battery cell;

[0039] Figure 2 This is a simplified schematic diagram of a battery cell in one embodiment of the present utility model;

[0040] Figure 3 This is a schematic diagram of a cover plate assembly in one embodiment of the present invention;

[0041] Figure 4 for Figure 3 Middle AA section view;

[0042] Figure 5 for Figure 4 A partial enlarged view of

[0043] Figure 6 for Figure 4 Enlarged view of middle part B;

[0044] Figure 7 This is a schematic diagram of a lower insulating member in one embodiment of the present utility model;

[0045] Figure 8 This is a schematic diagram of a lower insulating member in one embodiment of the present utility model;

[0046] Figure 9 This is a schematic diagram of a first sealing ring in an embodiment of the present utility model;

[0047] Figure 10 This is a schematic diagram of a first sealing ring in an embodiment of the present utility model;

[0048] Figure 11 for Figure 10 Middle CC section view;

[0049] Figure 12 for Figure 11 A partial enlarged view of

[0050] Figure 13 This is a schematic diagram of the cooperation between the lower insulating member and the first sealing ring in one embodiment of the present utility model;

[0051] Figure 14 for Figure 13 Enlarged view of the middle D part;

[0052] Figure 15 It is a partial cross-sectional view of another embodiment of the present invention.

[0053] Description of reference numerals:

[0054] Cover plate assembly 100;

[0055] Cover plate body 1;

[0056] Pole 2, connecting plate 21, columnar body 22; connecting piece 9;

[0057] Lower insulating member 3, second through hole 31, groove 32, first groove 321, second groove 322;

[0058] First sealing ring 4, third through hole 41, main body 42, extension part (end part) 43;

[0059] Second sealing ring 5;

[0060] Upper insulating member 6;

[0061] Anti-rotation part 7;

[0062] Housing 200;

[0063] Accommodating chamber 300;

[0064] Electrode assembly 400, tab 410;

[0065] Battery cells 1000. DETAILED DESCRIPTION

[0066] The following describes in detail embodiments of the present invention, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0067] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0069] Example 1

[0070] This embodiment provides a battery cell. Figure 2-Figure 14 is a schematic diagram of this embodiment.

[0071] like Figure 2 The battery cell 1000 includes a housing 200, a cover plate assembly 100, and an electrode assembly 400. The cover plate assembly 100 is disposed on the housing 200 and defines a receiving cavity 300 with the housing 200. The electrode assembly 400 is disposed within the receiving cavity 300. The number of electrode assemblies 400 can be one, two, three, four, or other values.

[0072] like Figure 3-Figure 6 The cover assembly 100 includes a cover and a pole 2. The cover has a pole through hole along the thickness direction T. The cover includes a cover body 1 and a lower insulating member 3. The lower insulating member 3 is located on one side of the cover body 1 in the thickness direction. When plastic material is used, it can also be called lower plastic. The structure is as follows Figure 7 、 Figure 8 As shown, the first through-hole on the cover body 1 and the second through-hole 31 on the lower insulating member 3 are coaxial, and the pole through-hole includes the first through-hole and the second through-hole 31. The pole 2 includes a columnar body 22 passing through the pole through-hole and a connecting plate 21 electrically connected to the columnar body 22. The connecting plate 21 is located on the side of the lower insulating member 3 facing away from the cover body 1, facing the electrode assembly 400, and the connecting plate 21 is electrically connected to the electrode tab 410 of the electrode assembly 400.

[0073] In this embodiment, the cover plate assembly 100 is disposed at one end of the battery cell 1000 in the height direction, and the T direction of the cover plate body 1 is parallel to the height direction of the battery cell 1000. When the battery cell 1000 is laid flat, the cover plate body 1 is located above the lower insulating member 3, and the lower insulating member 3 is located above the connecting plate 21. In other embodiments, the cover plate assembly 100 can be disposed at one end of the battery cell 1000 in the width or length direction.

[0074] like Figure 5 、 Figure 6 The upper and lower edges of the second through hole 31 of the lower insulating member 3 are formed with two grooves 32 to connect with the second through hole 31, namely a first groove 321 and a second groove 322. The first groove 321 is formed at the upper edge of the second through hole 31, and the lower insulating member 3 faces the surface of the cover body 1. The second groove 322 is formed at the lower edge of the second through hole 31, and the lower insulating member 3 faces the surface of the connecting plate 21. Figure 3-Figure 6 The cover plate assembly 100 further includes a first sealing ring 4. The structure of the first sealing ring 4 is as follows: Figures 9-12 As shown, the first sealing ring 4 is sleeved on the edge of the second through hole 31, and the two ends of the first sealing ring 4, namely the two protrusions 43, extend into the two grooves 32. Specifically, the upper side of the first sealing ring 4 is sleeved on the upper edge of the second through hole 31, and the upper protrusion 43 extends into the first groove 321. The lower side is sleeved on the lower edge of the second through hole 31, and the lower protrusion 43 extends into the second groove. By arranging the protrusion 43 of the first sealing ring 4 to extend into the groove 32 connected to the second through hole 31 to form a seal, the electrolyte penetration path can be increased, and the risk of electrolyte penetrating along the surface of the lower insulating member 3 to electrically connect the cover body 1 and the connecting plate 21 can be reduced. On the one hand, the risk of voltage abnormality caused by the electrolyte conducting between the cover body 1 and the connecting plate 21 can be reduced; on the other hand, the risk of electrolyte penetrating into the cover body 1 and corroding the cover body 1 can be reduced, thereby improving the safety and reliability of the cover body 1.

[0075] In this embodiment, the groove 32 is provided on the lower insulator 3, eliminating the need for the groove 32 on the cover body 1 or the connecting plate 21. This allows the process for providing the groove 32 to be centralized on the lower insulator 3, reducing manufacturing costs. Furthermore, this prevents the presence of the groove 32 from weakening the strength of the cover body 1 and the connecting plate 21, or the current carrying capacity of the connecting plate 21. In other embodiments, the surface of the cover body 1 facing the lower insulator 3 and the surface of the connecting plate 21 facing the lower insulator 3 may both be provided with a groove 32 to connect to the second through hole 31 and allow the extension 43 of the first sealing ring 4 to extend therein to form a seal.

[0076] In this embodiment, grooves 32 are provided at corresponding positions on both sides of the first sealing ring 4 along the T direction for double-sided sealing, thereby improving the reliability of preventing electrolyte penetration. In other embodiments, grooves 32 may be provided only at corresponding positions on one side of the first sealing ring 4 along the T direction for single-sided sealing. In other embodiments, grooves 32 may be provided on both the surface of the lower insulating member 3 facing the cover body 1 and the surface of the cover body 1 facing the lower insulating member 3 to connect to the second through hole 31, so that an extension 43 of the first sealing ring 4 can extend into these two grooves 32; grooves 32 may be provided on both the surface of the lower insulating member 3 facing the connecting plate 21 and the surface of the connecting plate 21 facing the lower insulating member 3 to connect to the second through hole 31, so that an extension 43 of the first sealing ring 4 can extend into these two grooves 32.

[0077] Better, such as Figure 5 The cover plate assembly 100 further includes a second sealing ring 5, which is disposed within the through-hole of the pole and sleeved onto the outside of the columnar body 22. In this embodiment, the cross-section of the second sealing ring 5 along the T-direction is L-shaped, also known as an L-shaped sealing ring. The portion of the second sealing ring 5 extending along the T-direction is located inside the first through-hole of the cover plate body 1. The portion of the second sealing ring 5 extending perpendicular to the T-direction is located inside the second through-hole 31 of the lower insulator 3. The upper surface of the second sealing ring 5 contacts the surface of the cover plate body 1 facing the lower insulator 3, and the lower surface contacts the surface of the connecting plate 21 facing the lower insulator 3, thereby forming a seal against the columnar body 22.

[0078] Preferably, the first sealing ring 4 and the second sealing ring 5 are spaced apart to form a spacing space. On the one hand, the consumables of the first sealing ring 4 can be reduced, thereby reducing costs. On the other hand, the spacing space between the first sealing ring 4 and the second sealing ring 5 can serve as a deformation space for components in the cover assembly 100. When the cover assembly 100 is impacted or heated, the deformation of the components of the cover assembly 100 can squeeze the space, thereby preventing the cover assembly 100 from expanding outward and affecting other structures.

[0079] Preferably, the diameter (i.e., inner diameter) of the first through hole on the cover body 1 is smaller than the diameter (i.e., inner diameter) of the second through hole 31 on the lower insulating member 3, so that the portion of the second sealing ring 5 extending perpendicular to the T direction can be arranged in the second through hole 31, thereby improving the sealing effect on the columnar body 22.

[0080] Better, such as Figure 5The cover assembly 100 also includes a connector 9 electrically connected to the column 22. The connector 9 is sleeved on the column 22 and is located on the upper side of the cover body 1. The connector 9 with a larger outer diameter is provided to facilitate the electrical connection of the pole 2 and other devices. The connector 9 and the column 22 can be electrically connected by welding or riveting, etc., and can be electrically connected by providing a metal layer on the facing surfaces of the connector 9 and the column 22; similarly, the column 22 and the connecting plate 21 can be electrically connected by welding, riveting or a metal layer; the connecting plate 21 and the tab 410 can be electrically connected by laser welding. In other embodiments, the column 22 and the connector 9 can be integrally formed, or the column 22 and the connecting plate 21 can be integrally formed; the integral forming method includes machining, 3D printing, etc.

[0081] The cover body 1, connector 9, columnar body 22, and connecting plate 21 can be made of pure aluminum, pure copper, nickel-plated copper, alloys, etc. In this embodiment, the cover body 1 is made of aluminum, which can be called an aluminum plate. The connector 9 is made of aluminum. When the battery has multiple cells 1000, the connectors 9 of multiple cells 1000 in the battery can be connected and combined through the aluminum busbar. The connecting plate 21 is made of copper to facilitate electrical connection to the tab 410 when the tab is made of copper.

[0082] like Figure 5 , an upper insulating member 6 is provided between the connector 9 and the cover body 1, which can also be called upper plastic when made of plastic material. In this embodiment, the lower insulating member 3, the first sealing ring 4, the second sealing ring 5 and the upper insulating member 6 are made of insulating material. The lower insulating member 3 is used for insulation between the cover body 1 and the connecting plate 21, the second sealing ring 5 is used for insulation between the cover body 1 and the columnar body 22 of the pole 2, and the upper insulating member 6 is used for insulation between the connector 9 and the cover body 1. It can be understood that the description of the sealing ring in the present invention uses a ring or annular shape, which means that the sealing ring has an annular through hole. The through hole can be specifically circular, square or other shapes. The outer shape of the sealing ring can be set according to specific needs. In this embodiment, the second through hole 31, the connector 9 and the columnar body 22 are all circular structures. Correspondingly, the first sealing ring 4, the second sealing ring 5 and the upper insulating member 6 are circular ring structures.

[0083] Better, such as Figure 5 The connector 9 and the upper insulating member 6 are matched in a concave-convex manner, and the cover assembly 100 is also provided with an anti-rotation member 7 inserted into the upper insulating member 6 and the cover body 1 to prevent the cover body 1 and the upper insulating member 6 from rotating relative to each other and pulling the pole 2 when the battery cell 1000 is impacted, causing the electrical connection between the pole 2 and the connecting plate 21, or the connecting plate 21 and the column 22, or the column 22 and the connector 9, or the connector 9 and other equipment to be disconnected, thereby improving the reliability of the battery cell 1000.

[0084] like Figures 9-12The first sealing ring 4 has a main body 42, and two extensions 43 are located on the upper and lower sides of the main body 42. The main body 42 and one of the extensions 43 together form an L-shaped L portion with an L-shaped cross section along the T direction. In this embodiment, the first sealing ring 4 has two L portions. Figure 12 The approximate boundary between the extension portion 43 and the main body portion 42 is indicated by a dotted line for easier understanding. In fact, in this embodiment, the main body portion 42 and the extension portion 43 are integrally formed.

[0085] Preferably, the two grooves 32 have the same size, and the two protruding portions 43 have the same size, so as to facilitate processing.

[0086] The compression amount of the extension 43 is (original volume - compressed volume) / original volume. Figure 6 , the dimension of the groove 32 along the T direction, ie the depth, is h1; Figure 12 The original dimension of the extension 43 along the T direction is h2, and the compression of the extension 43 can be expressed as (h2-h1) / h2. Preferably, the compression of the extension 43 is between 15% and 45%. On the one hand, the compression of the extension 43 can be sufficiently small, thereby reducing the force exerted by the two extensions 43 on the cover body 1 and the connecting plate 21, thereby reducing the stress on the cover body 1 and the connecting plate 21. On the other hand, the compression of the extension 43 can be sufficiently large to ensure sufficient sealing at the groove 32, thereby ensuring sufficient reliability in preventing leakage.

[0087] Preferably, the depth h1 of the groove 32 is between 0.04 mm and 0.06 mm. This ensures that the depth of the groove 32 is sufficiently large for ease of processing and sufficient sealing when the first sealing ring 4 is compressed within the groove 32. Furthermore, the depth of the groove 32 is sufficiently small to avoid excessively weakening the structural performance of the lower insulator 3, the cover body 1, or the connecting plate 21. In this embodiment, h1 = 0.05 mm, resulting in approximately 30% compression of the extension 43. In other embodiments, the depth of the groove 32 and the compression of the extension 43 can be flexibly adjusted based on the dimensions of the cover body 1, the lower insulator 3, the connecting plate 21, and other components.

[0088] like Figure 11 The inner diameter of the first sealing ring 4 is D1, that is, the diameter D1 of the third through hole 41 in the first sealing ring 4, and the outer diameter of the first sealing ring 4 is D2, D2 is larger than the inner diameter of the second through hole 31 in the lower insulating member 3, so that the first sealing ring 4 and the second through hole 31 of the lower insulating member 3 are interference fit, so that the lower insulating member 3 and the first sealing ring 4 are tightly attached, further improving the reliability of preventing electrolyte penetration.

[0089] like Figure 11 、 Figure 12, the cross-section of the first sealing ring 4 along the T direction is [-shaped, with a simple structure and easy processing. Preferably, the corners of the [-shaped corners of the first sealing ring, that is, the corners of the main body 42 and the extension portion 43, are specifically arc angles, so that the first sealing ring 4 is easy to process. When the first sealing ring 4 is cast, the arc angles facilitate demolding. Specifically, the inner corner and / or the outer corner can be set as an arc angle. In other embodiments, the cross-section of the first sealing ring 4 along the T direction can be set to U-shaped or C-shaped, which can also facilitate processing. In other embodiments, the shape of the first sealing ring 4 can be flexibly adjusted according to the shape of the groove 32 and the second through hole 31 in the lower insulating member 3. In other embodiments, the cross-sectional profile of the second through hole 31 along the T direction can be set to be an arc convex toward the columnar body 22. On the first hand, it can play a guiding role to facilitate the first sealing ring 4 to be installed into the second through hole 31; on the second hand, it can increase the contact area between the surface of the second through hole 31 and the surface of the first sealing ring 4, increase the friction force, and improve the sealing reliability of the first sealing ring 4; on the third hand, when the first sealing ring 4 adopts a C-shaped or U-shaped structure, it has a concave arc, which facilitates the close fit between the concave arc of the first sealing ring 4 and the convex arc of the second through hole 31.

[0090] The battery cell 1000 provided by the present invention includes but is not limited to: being used as a single battery, being used as the battery cell 1000 in a battery pack; and being used as a power source for electrical equipment such as mobile phones, cars, computers, household appliances, machine tools, and robots.

[0091] Example 2

[0092] This embodiment provides a battery cell. Figure 15 This is a partial cross-sectional view of the cover plate assembly of this embodiment. The difference between this embodiment and embodiment 1 mainly lies in the arrangement of the groove 32 and the first sealing ring 4. The other structures of this embodiment are the same as those of embodiment 1.

[0093] like Figure 15 , a groove 32 is provided only at a corresponding position on one side of the first sealing ring 4 along the T-direction to form a single-sided seal, simplifying the structure of the cover assembly. The groove 32 is a second groove 322 formed on the surface of the lower insulator 3 facing the connecting plate 21. The cross-section of the first sealing ring along the T-direction is L-shaped, forming an L-portion. The end of the L-shape, i.e., the extension 43, extends perpendicular to the thickness direction and is located within the second groove 322. In other embodiments, the first groove can be provided on the surface of the first sealing ring 4 facing the cover body 1. The first sealing ring 4 in this embodiment can be inverted so that the extension 43 is located within the first groove.

[0094] The groove 32 and the first sealing ring 4 in this embodiment can be applied to other embodiments to obtain a new cover plate assembly or battery cell.

[0095] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of protection of the present invention.

Claims

1. A cover plate assembly, characterized in that: It includes: A cover plate having a pole through hole along its thickness direction; the cover plate comprises a cover plate body and a lower insulating member located on one side of the cover plate body in the thickness direction; the pole through hole comprises a first through hole formed in the cover plate body and a second through hole formed in the lower insulating member, the first through hole and the second through hole being coaxial; The pole comprises a columnar body and a connecting plate; the columnar body passes through the pole through hole, and the connecting plate is located on a side of the lower insulating member away from the cover body; At least one groove along the thickness direction is formed in the edge of the second through hole, the surface of the cover plate body facing the lower insulating member, and the surface of the connecting plate facing the lower insulating member, and the groove is connected to the second through hole; The cover plate assembly also includes a first sealing ring, which is sleeved on the edge portion, and the end of the first sealing ring extends into the groove. The first sealing ring contacts the surface of the cover plate body facing the lower insulating member and contacts the surface of the connecting plate facing the lower insulating member.

2. A cover plate assembly according to claim 1, characterized in that: One of the grooves is a first groove formed on the surface of the lower insulating member facing the cover plate body or a second groove on the surface facing the connecting plate; the first sealing ring has an L-shaped portion with an L-shaped cross-section along the thickness direction, the L-portion is sleeved on the edge portion, and the part of the L-portion extending perpendicular to the thickness direction forms the end portion, and the end portion extends into the first groove or the second groove.

3. The cover plate assembly according to claim 1, wherein: The number of the grooves is at least two, and the two grooves are a first groove formed on the surface of the lower insulating member facing the cover body and a second groove formed on the surface facing the connecting plate; the cross-section of the first sealing ring along the thickness direction is [-shaped, U-shaped or C-shaped, and the two ends of the first sealing ring on both sides along the thickness direction, one extends into the first groove, and the other extends into the second groove.

4. A cover plate assembly according to claim 3, characterized in that: The cross section of the first sealing ring along the thickness direction is [-shaped, and the corners of the [-shaped are arc angles.

5. The cover plate assembly according to claim 1, wherein: A diameter of the first through hole is smaller than a diameter of the second through hole.

6. A cover plate assembly as claimed in claim 1, characterized in that: The cover plate assembly further includes a second sealing ring, which is arranged in the pole through hole and sleeved on the outside of the columnar body.

7. The cover plate assembly according to claim 6, wherein: The second sealing ring and the first sealing ring are spaced apart.

8. The cover plate assembly according to claim 1, wherein: The compression amount of the portion of the first sealing ring located in the groove is between 15% and 45%; And / or, a dimension of the groove along the thickness direction is between 0.04 mm and 0.06 mm.

9. The cover plate assembly according to claim 1, wherein: The first sealing ring and the second through hole are interference fit; And / or, a cross-sectional profile of the second through hole along the thickness direction is in an arc shape convex toward the columnar body.

10. A battery cell, characterized in that: It includes: case; The cover plate assembly according to any one of claims 1 to 9, wherein the cover plate assembly is disposed on the housing and defines a receiving cavity together with the housing, and the connecting plate is located on a side of the cover plate facing the receiving cavity along the thickness direction; At least one electrode assembly is accommodated in the accommodating cavity, and the electrode tab of the electrode assembly is electrically connected to the connecting plate.

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