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 body, a lower insulating part, a pole and a pole sealing ring, the columnar body of the pole penetrates through the pole through hole, 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; an annular matching flange is arranged in the second through hole, or an annular matching groove is formed in the middle of the second through hole, or an annular matching groove is formed in the edge part facing one side of the connecting plate, the body part of the pole sealing ring is sleeved outside the columnar body, and the protruding part extends into two sides of the matching flange along the thickness direction, or extends into the matching groove; the protruding part is in contact with the cover plate body and the connecting plate, so that 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 5' 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 4' with an L-shaped cross-section is usually installed around the pole 2'. The compressed part of the L-shaped sealing ring 4' will be compressed into the cavity 8' 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 injection 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 4', 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 5' 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] a pole sealing ring, disposed in the pole through-hole, comprising a main body portion sleeved on the outside of the columnar body and a protrusion portion extending away from the columnar body from the main body portion, wherein the protrusion portion contacts a surface of the cover plate body facing the connecting plate and contacts a surface of the connecting plate facing the cover plate body;

[0011] The lower insulating member has an annular mating flange, which is arranged in the second through hole, forming a first gap with the surface of the cover body facing the connecting plate, and forming a second gap with the surface of the connecting plate facing the cover body, and the protrusion extends into the first gap and the second gap, contacting the surfaces on both sides of the mating flange along the thickness direction.

[0012] In this solution, the protrusion of the lower insulating member contacts the surface of the cover body facing the connecting plate, and contacts the surface of the connecting plate facing the cover body, thereby forming a seal for the columnar body.

[0013] An annular mating flange is provided in the second through hole of the lower insulating member, and the protrusion of the pole sealing ring extends into the first gap and the second gap, that is, extends into both sides of the mating flange along the thickness direction. The protrusion contacts the surfaces of both sides of the mating flange along the thickness direction, forming a seal on both sides of the mating flange along the thickness direction, 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 plate body and the connecting plate. On the one hand, it can reduce the risk of voltage abnormality caused by the cover plate body and the connecting plate being connected by the electrolyte; on the other hand, it can reduce the risk of the electrolyte penetrating into the cover plate body and corroding the cover plate body; thereby, the safety and reliability of the cover plate body can be improved.

[0014] Preferably, the mating flange has a connecting surface connecting two side surfaces of the mating flange along the thickness direction; and the protrusion is in contact with the connecting surface.

[0015] In this solution, the protrusion is in contact with the connection surface, which can increase the contact area between the protrusion and the mating flange, improve the sealing performance, and further improve the reliability of preventing electrolyte penetration.

[0016] Preferably, the mating flange has a connecting surface connecting two side surfaces of the mating flange along the thickness direction, and the connecting surface is an arc surface protruding toward the columnar body.

[0017] In this solution, the connecting surface is an arc surface protruding toward the columnar body. On the one hand, it can play a guiding role, facilitating the protrusion to extend to both sides of the mating flange along the thickness direction; on the other hand, it can avoid damage to the mating flange and the protrusion.

[0018] Preferably, the dimension of the fitting flange along the thickness direction is between 0.5 mm and 0.6 mm.

[0019] In this solution, the arrangement is such that, on the one hand, the mating flange is large enough, strong enough, and easy to process; on the other hand, the mating flange is small enough to leave enough space on both sides of the mating flange along the thickness direction for the protrusion to extend into, so as to ensure sealing.

[0020] Preferably, the sum of the volumes of the portions of the protrusion extending into the first gap and the second gap is less than 2 mm. 3 ~3mm 3 between;

[0021] And / or, the sum of the volumes of the portions of the protrusion extending into the first gap and the second gap is smaller than the sum of the volumes of the first gap and the second gap.

[0022] In this solution, the arrangement is such that the volume of the portion of the protrusion extending into the first gap and the second gap is appropriate to ensure sealing.

[0023] Preferably, the cross section of the pole sealing ring along the thickness direction is L-shaped.

[0024] In this solution, the structure is simple and the processing direction is convenient.

[0025] A cover plate assembly, comprising:

[0026] 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;

[0027] 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;

[0028] a pole sealing ring, disposed in the pole through-hole, comprising a main body portion sleeved on the outside of the columnar body and a protrusion portion extending away from the columnar body from the main body portion, wherein the protrusion portion contacts a surface of the cover plate body facing the connecting plate and contacts a surface of the connecting plate facing the cover plate body;

[0029] The lower insulating member has an annular matching groove, which is arranged in the middle of the second through hole along the thickness direction. The protrusion extends into the matching groove and contacts the surfaces on both sides of the matching groove along the thickness direction.

[0030] In this solution, the protruding portion of the lower insulating member contacts the surface of the cover body facing the connecting plate, and contacts the surface of the connecting plate facing the cover body, thereby forming a seal for the columnar body.

[0031] An annular mating groove is provided in the middle of the second through hole of the lower insulating member, and the protrusion of the pole sealing ring extends into the mating groove and contacts the surfaces on both sides of the mating groove along the thickness direction, forming a seal at the mating 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 plate body and the connecting plate. On the one hand, it can reduce the risk of voltage abnormality caused by the cover plate body and the connecting plate being connected by the electrolyte; on the other hand, it can reduce the risk of the electrolyte penetrating into the cover plate body and corroding the cover plate body; thereby, the safety and reliability of the cover plate body can be improved.

[0032] Preferably, a chamfer is provided at the junction between the matching groove and the second through hole.

[0033] In this solution, such an arrangement can, on the one hand, play a guiding role, facilitating the protrusion to extend into the matching groove; on the other hand, it can avoid damage to the matching groove and the protrusion.

[0034] Preferably, the dimension of the fitting groove along the thickness direction is between 0.3 mm and 0.4 mm.

[0035] In this solution, the arrangement is such that, on the one hand, the size of the mating groove is large enough to facilitate processing and ensure that the protrusion is well sealed when inserted into the mating groove; on the other hand, the size of the mating groove is small enough so that the size of the lower insulating part on both sides of the mating groove along the thickness direction is large enough to ensure processing convenience and structural strength.

[0036] Preferably, the volume of the portion of the protrusion that extends into the matching groove is 2 mm 3 ~3mm 3 between.

[0037] In this solution, the arrangement is such that a sufficient portion of the protrusion extends into the matching groove to ensure a sufficiently good sealing performance at the matching groove.

[0038] A cover plate assembly, comprising:

[0039] 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;

[0040] 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;

[0041] A pole sealing ring is provided in the pole through hole and comprises a main body portion sleeved on the outside of the columnar body and a protrusion portion away from the columnar body from the main body portion;

[0042] The lower insulating member has an annular mating groove, which is provided at the edge of the second through hole facing the connecting plate. The protrusion extends into the mating groove. The protrusion contacts the surface of the cover body facing the connecting plate, contacts the surface of the mating groove facing the connecting plate, and contacts the surface of the connecting plate facing the cover body.

[0043] In this solution, the protruding portion of the lower insulating member contacts the surface of the cover body facing the connecting plate, and contacts the surface of the connecting plate facing the cover body, thereby forming a seal for the columnar body.

[0044] A mating groove is provided on the edge portion of the second through hole of the lower insulating member along the thickness direction toward the connecting plate side, and the protrusion of the pole sealing ring extends into the mating groove, contacts the surface of the mating groove toward the connecting plate, and contacts the surface of the connecting plate toward the cover plate body, forming a seal at the mating 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 plate body and the connecting plate. On the one hand, it can reduce the risk of voltage abnormality caused by the cover plate body and the connecting plate being connected by the electrolyte; on the other hand, it can reduce the risk of the electrolyte penetrating into the cover plate body and corroding the cover plate body; thereby, the safety and reliability of the cover plate body can be improved.

[0045] Preferably, the protrusion includes a first protrusion and a second protrusion, the first protrusion is away from the columnar body from the main body, the first protrusion is in contact with the surface of the cover body facing the connecting plate, the second protrusion is away from the columnar body from the first protrusion, extends into the matching groove, and contacts the surface of the matching groove facing the connecting plate, the dimension of the first protrusion along the thickness direction is greater than the dimension of the second protrusion along the thickness direction, and the surfaces of the first protrusion and the second protrusion facing the connecting plate are both in contact with the surface of the connecting plate facing the protrusions.

[0046] In this embodiment, the larger first protrusion contacts the surface of the cover plate body facing the connecting plate, and the surface of the connecting plate facing the cover plate body, forming a seal against the columnar body. The smaller second protrusion contacts the surface of the mating groove facing the connecting plate, and the surface of the connecting plate facing the protrusion, forming a seal at the mating groove. Separating the two parts to achieve separate sealing of the columnar body and the mating groove improves the reliability of the sealing at the mating groove.

[0047] Preferably, surfaces of the first protrusion and the second protrusion facing the connecting plate are located in the same plane.

[0048] In this solution, such an arrangement has a simple structure, is easy to process, and can also improve the sealing effect.

[0049] Preferably, the cross-section of the second protrusion along the thickness direction is rectangular.

[0050] In this solution, such an arrangement has a simple structure, is easy to process, and has a good sealing effect.

[0051] Preferably, the dimension of the second protrusion along the thickness direction is between 0.1 mm and 0.3 mm.

[0052] In this solution, the second protrusion is configured in such a way that the size of the second protrusion is appropriate, the processing is convenient, and the sealing reliability is good enough after the second protrusion is inserted into the matching groove.

[0053] Preferably, the dimension of the fitting groove along the thickness direction is between 0.05 mm and 0.25 mm.

[0054] In this solution, the arrangement is such that, on the one hand, the size of the mating groove is large enough to facilitate processing and ensure that the protrusion is well sealed when it extends into the mating groove; on the other hand, the size of the mating groove is small enough to avoid excessive weakening of the structural strength of the lower insulating part at the second through hole due to the arrangement of the mating groove.

[0055] Preferably, the inner diameter of the matching groove is 0.2 mm to 0.4 mm larger than the outer diameter of the protrusion.

[0056] In this solution, the arrangement is such that after the protrusion extends into the matching groove, the portion in the matching groove is compressed appropriately, thereby ensuring a sufficiently good sealing performance.

[0057] Preferably, the cross section of the pole sealing ring along the thickness direction is stepped.

[0058] In this solution, the structure is simple and the processing is convenient.

[0059] A battery cell, comprising:

[0060] case;

[0061] 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;

[0062] 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.

[0063] The positive progress effect of this utility model is:

[0064] The protruding portion of the pole sealing ring contacts the surface of the cover plate body facing the connecting plate and contacts the surface of the connecting plate facing the cover plate body, thereby forming a seal on the columnar body.

[0065] By arranging an annular mating flange in the second through hole, the protrusion extends into both sides of the mating flange along the thickness direction and contacts the surfaces of these two sides, forming a seal on these two sides; or, an annular mating groove is arranged in the middle part along the thickness direction in the second through hole, the protrusion extends into the mating groove and contacts the both sides of the mating groove along the thickness direction, forming a seal at the mating groove; or, an annular mating groove is arranged in the edge part of the second through hole along the thickness direction toward the connecting plate, the protrusion extends into the mating groove and contacts the surface of the mating groove toward the connecting plate along the thickness direction, forming a seal at the mating groove; thereby increasing the electrolyte penetration path and reducing the risk of the electrolyte penetrating along the surface of the lower insulating member to electrically connect the cover plate body and the connecting plate. On the one hand, the risk of the cover plate body and the connecting plate being connected by the electrolyte causing voltage abnormality can be reduced; on the other hand, the risk of the electrolyte penetrating into the cover plate body and corroding the cover plate body can be reduced; thereby improving the safety and reliability of the cover plate body.

[0066] By changing the shape of the lower insulating member or the pole sealing ring, the shape of the cavity between the body, the lower insulating member, and the connecting plate of the pole is changed, thereby improving the sealing performance of the pole sealing ring and reducing the remaining space in the cavity after the pole sealing ring is installed in place, while also preventing the electrolyte from flowing into the cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 is a schematic diagram of an existing battery cell;

[0068] Figure 2 This is a simplified schematic diagram of the battery cell of the present utility model;

[0069] Figure 3 It is a top view of the cover plate assembly in the present invention;

[0070] Figure 4 For Example 1 Figure 3 Cross-sectional view in the AA direction;

[0071] Figure 5 for Figure 4 A partial enlarged view of

[0072] Figure 6 This is an enlarged view of part B;

[0073] Figure 7 for Figure 6 Remove the crosshatching diagram;

[0074] Figure 8 This is a dimension diagram of Example 1;

[0075] Figure 9 is a three-dimensional diagram of the lower insulating member in Example 1;

[0076] Figure 10 is a top view of the lower insulating member in Example 1;

[0077] Figure 11 It is the CC section view;

[0078] Figure 12 The cover plate assembly in Example 2 corresponds to Figure 3 Cross-sectional view in the AA direction;

[0079] Figure 13 for Figure 12 A partial enlarged view of

[0080] Figure 14 This is an enlarged view of part D;

[0081] Figure 15 This is a dimensioning diagram of Example 2;

[0082] Figure 16 is a three-dimensional diagram of the lower insulating member in Example 2;

[0083] Figure 17 is a top view of the lower insulating member in Example 2;

[0084] Figure 18 It is the EE cross-sectional view;

[0085] Figure 19 The cover plate assembly in Example 3 corresponds to Figure 3 Cross-sectional view in the AA direction;

[0086] Figure 20 for Figure 19 A partial enlarged view of

[0087] Figure 21 This is an enlarged view of part F;

[0088] Figure 22 is a three-dimensional diagram of the lower insulating member in Example 3;

[0089] Figure 23 is a top view of the lower insulating member in Example 3;

[0090] Figure 24 It is the GG cross-sectional view;

[0091] Figure 25 This is an enlarged view of part H;

[0092] Figure 26 is a three-dimensional diagram of the pole seal in Example 3;

[0093] Figure 27 This is a top view of the pole seal in Example 3.

[0094] Description of reference numerals:

[0095] Cover plate assembly 100;

[0096] Cover plate body 1;

[0097] Pole 2, connecting plate 21, columnar body 22;

[0098] Lower insulating member 3, second through hole 31, first gap 311, second gap 312, matching protrusion 32, matching groove 33;

[0099] The pole sealing ring 4, the main body 41, the protrusion 42, the first protrusion 421, and the second protrusion 422;

[0100] Connector 5;

[0101] Upper insulating member 6;

[0102] Anti-rotation part 7;

[0103] Housing 200;

[0104] Accommodating chamber 300;

[0105] Electrode assembly 400, tab 410;

[0106] Battery cells 1000. DETAILED DESCRIPTION

[0107] 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.

[0108] 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.

[0109] 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.

[0110] Example 1

[0111] This embodiment provides a battery cell. Figure 2-Figure 11 is a schematic diagram of this embodiment.

[0112] 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.

[0113] like Figure 3-Figure 5 The cover assembly 100 includes a cover and a pole 2. The cover has a through hole for the pole 2 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 Figures 9-11 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 through-hole of the pole 2 includes the first through-hole and the second through-hole 31. The pole 2 includes a columnar body 22 and a connecting plate 21. The columnar body 22 passes through the through-hole of the pole 2. The connecting plate 21 is 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.

[0114] 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.

[0115] like Figure 4 、 Figure 5 The cover assembly 100 also includes a pole sealing ring 4, which is arranged in the through hole of the pole 2. The pole sealing ring 4 has a main body 41 and a protrusion 42. The main body 41 is sleeved on the outside of the column 22, and the protrusion 42 is arranged away from the main body 41 and away from the column 22. The protrusion 42 contacts the surface of the cover body 1 facing the connecting plate 21, and contacts the surface of the connecting plate 21 facing the cover body 1, forming a seal with the column 22.

[0116] like Figure 6 The lower insulating member 3 has an annular mating flange, which is arranged in the second through hole 31, forming a first gap 311 with the surface of the cover body 1 facing the connecting plate 21, and forming a second gap 312 with the surface of the connecting plate 21 facing the cover body 1. Figure 7 The dashed lines in the figure indicate the boundaries of the first gap 311 and the second gap 312. The protrusions 42 extend into the first gap 311 and the second gap 312, that is, into the upper and lower sides of the mating flange. The protrusions 42 contact the upper and lower surfaces of the mating flange, forming a seal on the upper and lower sides of the mating flange. By providing a sealing fit between the mating flange and the protrusion 42 of the pole sealing ring 4, the electrolyte penetration path can be increased, and it is difficult for the electrolyte to enter the cavity area surrounded by the lower insulating part 3, the cover body 1, the connecting plate 21 and the pole sealing ring 4 from the gap between the contact surface of the connecting plate 21 and the lower insulating part 3, and the gap between the contact surface of the cover body 1 and the lower insulating part 3. If a small amount of electrolyte enters the cavity area, the protrusion 42 can prevent the electrolyte from electrically conducting the connecting plate 21 and the cover body 1, thereby reducing the risk of the electrolyte penetrating along the surface of the lower insulating part 3 to electrically conduct the cover body 1 and the connecting plate 21. On the one hand, the risk of voltage abnormality caused by the cover body 1 and the connecting plate 21 being conducted by the electrolyte can be reduced; on the other hand, the risk of the electrolyte penetrating into the cover body 1 and corroding the cover body 1 can be reduced; thereby, the safety and reliability of the cover body 1 can be improved.

[0117] like Figure 6 The mating flange has a connecting surface, which connects the upper and lower surfaces of the mating flange. Preferably, the protrusion 42 contacts the connecting surface, which can increase the contact area between the protrusion 42 and the mating flange, improve the sealing performance, and further improve the reliability of preventing electrolyte penetration. Preferably, as Figure 6The connecting surface is an arc-shaped surface that protrudes toward the columnar body 22. On the one hand, it can serve as a guide to facilitate the protrusion 42 to extend to the upper and lower sides of the mating flange; on the other hand, it can prevent damage to the mating flange and the protrusion 42. In other embodiments, the connecting surface can be set to other shapes such as an elliptical surface.

[0118] Better, such as Figure 6 In this embodiment, the cross-section of the pole sealing ring 4 along the thickness direction is L-shaped, which provides a simple structure and facilitates processing. The protrusion 42 of the pole sealing ring 4 is deformed by extrusion, partially pressed into the first gap 311 and the second gap 312, wrapping around the mating flange. In other embodiments, a raised structure can be provided on the protrusion 42 of the pole sealing ring 4, so that the protrusion 42 can naturally extend into the first gap 311 and the second gap 312.

[0119] The dimensions in Example 1 are as follows: Figure 7 、 Figure 8 The dimensions of the flange, the pole seal ring 4, and the through hole of the pole 2 are as follows:

[0120] L1: inner diameter of the first through hole on the cover body 1;

[0121] L2: outer diameter of the protrusion 42 in the pole sealing ring 4;

[0122] L3: inner diameter of the mating flange;

[0123] T1: the dimension of the protrusion 42 of the pole sealing ring 4 along the thickness direction;

[0124] T2: dimension of the second through hole 31 along the thickness direction;

[0125] T3: Dimension of the mating flange along the thickness direction;

[0126] The volume V1 of the compressed portion of the protrusion 42 can be expressed as:

[0127]

[0128] The protrusion 42 is spaced from the area V2 inside the mating flange, i.e. Figure 7 The areas represented by colored blocks in :

[0129]

[0130] The sum of the volumes of the protrusion 42 extending into the first gap 311 and the second gap 312 is V3, which can be expressed as:

[0131] V3=V1-V2

[0132] The sum of the volumes of the first gap 311 and the second gap 312 is denoted by V4.

[0133] Preferably, V3 < V4, that is, the protrusion 42 extends into and occupies part of the first gap 311 and the second gap 312, leaving some remaining space, so that the seal is reliable. Preferably, V3 is 2 mm 3 ~3mm 3 The volume of the portion of the protrusion 42 extending into the first gap 311 and the second gap 312 is appropriate to ensure sealing. In other embodiments, V3 can be set to V4. It is understood that the numerical values ​​and numerical ranges in the present invention are allowed to have a reasonable error range.

[0134] Preferably, T3 is between 0.5mm and 0.6mm. On the one hand, T3 is large enough to ensure that the strength of the mating flange is high enough and the mating flange is easy to process; on the other hand, T3 is small enough to leave enough space for the upper and lower sides of the mating flange, that is, the dimensions of the first gap 311 and the second gap 312 along the thickness direction are large enough, and the sealing is good enough after the protrusion 42 extends into the upper and lower sides of the mating flange.

[0135] Preferably, L1=9.6mm, L2=11mm, L3=12mm, T1=1.1mm, T2=0.7mm, T3=0.6mm.

[0136] Better, such as Figure 5 The cover plate assembly 100 further includes a connector 5 electrically connected to the column 22. The connector 5 is sleeved onto the column 22 and is located on the upper side of the cover plate body 1. The connector 5 having a larger outer diameter facilitates electrical connection between the pole 2 and other devices. The connector 5 and the column 22 can be electrically connected by welding or riveting, or by providing a metal layer on the facing surfaces of the connector 5 and the column 22. Similarly, the column 22 and the connecting plate 21 can be electrically connected by welding, riveting, or using a metal layer. The connecting plate 21 and the tab 410 can be electrically connected by laser welding. In other embodiments In the embodiment, the columnar body 22 and the connecting member 5 can be integrally formed, or the columnar body 22 and the connecting member 5 can be integrally formed. The plate 21 can be integrally formed; methods of integrally forming include machining, 3D printing, and the like.

[0137] The cover body 1, connector 5, 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 5 is made of aluminum. When the battery has multiple cells 1000, the connectors 5 of multiple cells 1000 in the battery can be connected and combined through an 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.

[0138] like Figure 5, an upper insulating member 6 is provided between the connector 5 and the cover body 1, which can also be called upper plastic when plastic material is used. In this embodiment, the lower insulating member 3, the pole sealing ring 4 and the upper insulating member 6 are made of insulating materials. The lower insulating member 3 is used for insulation between the cover body 1 and the connecting plate 21, the pole sealing ring 4 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 5 and the cover body 1. It can be understood that the ring or annular structure in the present invention refers to a ring-shaped structure, which can be square, circular or other shapes; the through hole can specifically be 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 5 and the columnar body 22 are all circular structures, and correspondingly, the pole sealing ring 4 and the upper insulating member 6 are circular ring structures.

[0139] Better, such as Figure 5 The connector 5 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 5, or the connector 5 and other equipment to be disconnected, thereby improving the reliability of the battery cell 1000.

[0140] Example 2

[0141] This embodiment provides a battery cell, and a simplified schematic diagram of the battery cell in this embodiment is shown as follows Figure 2 , the top view of the cover assembly is as follows Figure 3 , other schematic diagrams in this embodiment are shown in Figures 12-18 The difference between this embodiment and embodiment 1 lies mainly in the arrangement of the lower insulating member 3 and the protrusion 42 in the pole sealing ring 4. The structure of the lower insulating member 3 is shown in FIG. Figure 16-Figure 18 The other structures of this embodiment are the same as those of embodiment 1.

[0142] like Figure 12-14 The pole sealing ring 4 is arranged in the through hole of the pole 2, and the main body 41 of the pole sealing ring 4 is sleeved on the outside of the columnar body 22. The protrusion 42 of the pole sealing ring 4 contacts the surface of the cover body 1 facing the connecting plate 21, and contacts the surface of the connecting plate 21 facing the cover body 1, forming a seal with the columnar body 22.

[0143] like Figure 14The lower insulating member 3 has an annular mating groove 33, which is located in the middle of the second through hole 31 along the thickness direction. The protrusion 42 extends into the mating groove 33 and contacts the upper and lower surfaces of the mating groove 33, forming a seal at the mating groove 33. This can increase the electrolyte penetration path and reduce 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. On the one hand, this reduces the risk of voltage abnormalities caused by electrolyte conduction between the cover body 1 and the connecting plate 21; on the other hand, it reduces the risk of electrolyte penetrating into the cover body 1 and corroding the cover body 1, thereby improving the safety and reliability of the cover body 1.

[0144] Better, such as Figure 21 In this embodiment, the cross-section of the pole sealing ring 4 along the thickness direction is L-shaped, which provides a simple structure and facilitates processing. The protrusion 42 of the pole sealing ring 4 is deformed by extrusion and partially pressed into the mating groove 33. In other embodiments, a raised structure can be provided on the protrusion 42 of the pole sealing ring 4, so that the protrusion 42 can naturally extend into the mating groove 33. The shape of the pole sealing ring 4 can be flexibly adjusted according to sealing requirements.

[0145] Better, such as Figure 14 The connection between the mating groove 33 and the second through hole 31 is provided with a rounded corner. On the one hand, it can serve as a guide to facilitate the extension of the protrusion 42 into the mating groove 33; on the other hand, it can prevent damage to the mating groove 33 and the protrusion 42. In other embodiments, the connection between the mating groove 33 and the second through hole 31 can be set to an elliptical shape or other shapes.

[0146] The dimensions in Example 2 are as follows: Figure 15 , the dimensions of the groove 33, the pole seal ring 4, and the through hole of the pole 2 are as follows:

[0147] The definitions of L1, L2, T1, T2, and V1 are the same as those in Example 1;

[0148] L3': inner diameter of the second through hole 31;

[0149] L4: inner diameter of the matching groove 33;

[0150] T3': dimension of the matching groove 33 along the thickness direction;

[0151] The distance between the protrusion 42 and the mating groove 33 is:

[0152]

[0153] The volume of the protrusion 42 extending into the matching groove 33 is V3', which can be expressed as:

[0154] V3′=V1-V2′

[0155] Preferably, V3' is 2mm 3 ~3mm 3 The protrusion 42 extends into the mating groove 33 sufficiently to ensure that the sealing performance at the mating groove 33 is good enough.

[0156] Preferably, T3' is between 0.3mm and 0.4mm. On the one hand, T3' is large enough to facilitate processing of the matching groove 33 and ensure that the protrusion 42 extends into the matching groove 33 with good sealing. On the other hand, T3' is small enough so that the parts of the lower insulating member 3 on the upper and lower sides of the matching groove 33 are thick enough to ensure processing convenience and structural strength.

[0157] Preferably, L1=9.6 mm, L2=11 mm, L3'=12 mm, L4'=13.6 mm, T1=1.1 mm, T2=0.7 mm, and T3'=0.4 mm.

[0158] The pole sealing ring 4 and the lower insulating member 3 in this embodiment can be applied to other embodiments to obtain a new cap plate assembly 100 or a battery cell 1000 .

[0159] Example 3

[0160] This embodiment provides a battery cell, and a simplified schematic diagram of the battery cell in this embodiment is shown as follows Figure 2 , the top view of the cover assembly is as follows Figure 3 , other schematic diagrams in this embodiment are shown in Figures 19-27 The difference between this embodiment and embodiment 1 lies mainly in the arrangement of the lower insulating member 3 and the protrusion 42 in the pole sealing ring 4. The structure of the lower insulating member 3 is shown in FIG. Figure 22-Figure 25 , the structure of the pole 2 seal is shown in Figure 26-Figure 27 The other structures of this embodiment are the same as those of embodiment 1.

[0161] like Figures 19-21 The pole sealing ring 4 is arranged in the through hole of the pole 2, and the main body 41 of the pole sealing ring 4 is sleeved on the outside of the columnar body 22. The protrusion 42 of the pole sealing ring 4 contacts the surface of the cover body 1 facing the connecting plate 21, and contacts the surface of the connecting plate 21 facing the cover body 1, forming a seal with the columnar body 22.

[0162] like Figure 21 The lower insulating member 3 has an annular matching groove 33, which is provided at the edge of the second through hole 31 facing the connecting plate 21, that is, at the lower edge of the second through hole 31. The marking of the matching groove 33 is shown in FIG. Figure 25The protrusion 42 extends into the matching groove 33, and the protrusion 42 contacts the surface of the connecting plate 21 facing the cover body 1, and also contacts the surface of the matching groove 33 facing the connecting plate 21, forming a seal at the matching groove 33, which can increase the electrolyte penetration path and reduce the risk of the electrolyte penetrating along the surface of the lower insulating member 3 to electrically connect the cover body 1 and the connecting plate 21. On the one hand, it can reduce the risk of voltage abnormality caused by the cover body 1 and the connecting plate 21 being connected by the electrolyte; on the other hand, it can reduce the risk of the electrolyte penetrating into the cover body 1 and corroding the cover body 1; thereby, the safety and reliability of the cover body 1 can be improved.

[0163] Better, such as Figure 21 The protrusion 42 includes a first protrusion 421 and a second protrusion 422. The first protrusion 421 is arranged away from the main body 41 and away from the column 22. The first protrusion 421 contacts the surface of the cover body 1 facing the connecting plate 21 and the surface of the connecting plate 21 facing the cover body 1, forming a seal with the column 22. The second protrusion 422 is arranged away from the first protrusion 421 and away from the column 22. The second protrusion 422 of the protrusion 42 extends into the mating groove 33 and contacts the surface of the mating groove 33 facing the connecting plate 21 and the surface of the connecting plate 21 facing the protrusion 42, forming a seal at the mating groove 33. The first protrusion 421 has a greater thickness dimension than the second protrusion 422, that is, the first protrusion 421 is thicker than the second protrusion 422. The thicker first protrusion 421 achieves sealing of the column 22, while the thinner second protrusion 422 achieves sealing at the mating groove 33, thereby improving the reliability of the sealing at the mating groove 33.

[0164] Better, such as Figure 21 The lower surface of the first protrusion 421 and the lower surface of the second protrusion 422 are located in the same plane, which makes the structure of the pole sealing ring 4 simple and easy to process, and can also improve the sealing effect.

[0165] Better, such as Figure 21 The cross-section of the pole sealing ring 4 along the thickness direction is stepped, and the cross-section of the second protrusion 422 along the thickness direction is rectangular, which makes the pole sealing ring 4 simple in structure and easy to process. In other embodiments, the shape of the second protrusion 422 can be set to other shapes such as stepped or wavy, and the shape of the pole sealing ring 4 can be flexibly adjusted according to sealing requirements.

[0166] Preferably, the dimension of the second protrusion 422 in the thickness direction, ie, the thickness, is between 0.1 mm and 0.3 mm, so that the second protrusion 422 has an appropriate size and is easy to process, and has good sealing reliability after being inserted into the matching groove 33 .

[0167] Preferably, the dimension of the mating groove 33 along the thickness direction, i.e., the depth, is between 0.05 mm and 0.25 mm. On the one hand, the dimension of the mating groove 33 is large enough to facilitate processing and ensure that the protrusion 42 extends into the mating groove 33 with good sealing performance; on the other hand, the dimension of the mating groove 33 is small enough to avoid excessive weakening of the structural strength of the lower insulating member 3 at the second through hole 31 due to the provision of the mating groove 33.

[0168] Preferably, the inner diameter of the matching groove 33 is 0.2 mm to 0.4 mm larger than the outer diameter of the protrusion 42, so that after the protrusion extends into the matching groove 33, the partial compression amount in the matching groove 33 is appropriate, ensuring sufficient sealing performance.

[0169] Preferably, the outer diameter of the second protrusion 422 is 2.8 mm larger than the outer diameter of the first protrusion 421, 0.2 mm larger than the inner diameter of the second through hole 31, and 0.3 mm smaller than the inner diameter of the matching groove 33. The thickness of the second protrusion 422 is 0.2 mm, and the depth of the matching groove 33 is 0.15 mm. Preferably, the compression of the second protrusion 422 is approximately 30%.

[0170] The pole sealing ring 4 and the lower insulating member 3 in this embodiment can be applied to other embodiments to obtain a new cap plate assembly 100 or a battery cell 1000 .

[0171] 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.

[0172] 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; a pole sealing ring, disposed in the pole through-hole, comprising a main body portion sleeved on the outside of the columnar body and a protrusion portion extending away from the columnar body from the main body portion, wherein the protrusion portion contacts a surface of the cover plate body facing the connecting plate and contacts a surface of the connecting plate facing the cover plate body; The lower insulating member has an annular mating flange, which is arranged in the second through hole, forming a first gap with the surface of the cover body facing the connecting plate, and forming a second gap with the surface of the connecting plate facing the cover body, and the protrusion extends into the first gap and the second gap, contacting the surfaces on both sides of the mating flange along the thickness direction.

2. A cover plate assembly according to claim 1, characterized in that: The mating flange has a connecting surface connecting two side surfaces of the mating flange along the thickness direction; The protrusion is in contact with the connecting surface, and / or the connecting surface is an arc surface convex toward the columnar body.

3. A cover plate assembly according to claim 2, characterized in that: The dimension of the fitting flange along the thickness direction is between 0.5 mm and 0.6 mm.

4. The cover plate assembly according to claim 1, wherein: The sum of the volumes of the portions of the protrusion extending into the first gap and the second gap is less than 2 mm. 3 ~3mm 3 between; And / or, the sum of the volumes of the portions of the protrusion extending into the first gap and the second gap is smaller than the sum of the volumes of the first gap and the second gap.

5. The cover plate assembly according to claim 1, wherein: The cross section of the pole sealing ring along the thickness direction is L-shaped.

6. 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; a pole sealing ring, disposed in the pole through-hole, comprising a main body portion sleeved on the outside of the columnar body and a protrusion portion extending away from the columnar body from the main body portion, wherein the protrusion portion contacts a surface of the cover plate body facing the connecting plate and contacts a surface of the connecting plate facing the cover plate body; The lower insulating member has an annular matching groove, which is arranged in the middle of the second through hole along the thickness direction. The protrusion extends into the matching groove and contacts the surfaces on both sides of the matching groove along the thickness direction.

7. A cover plate assembly according to claim 6, characterized in that: A chamfer is provided at the junction of the matching groove and the second through hole; and / or, the dimension of the mating groove along the thickness direction is between 0.3 mm and 0.4 mm; And / or, the volume of the portion of the protrusion that extends into the matching groove is less than 2 mm 3 ~3mm 3 between.

8. 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; A pole sealing ring is provided in the pole through hole and comprises a main body portion sleeved on the outside of the columnar body and a protrusion portion away from the columnar body from the main body portion; The lower insulating member has an annular mating groove, which is provided at the edge of the second through hole facing the connecting plate. The protrusion extends into the mating groove. The protrusion contacts the surface of the cover body facing the connecting plate, contacts the surface of the mating groove facing the connecting plate, and contacts the surface of the connecting plate facing the cover body.

9. A cover plate assembly according to claim 8, characterized in that: The protrusion includes a first protrusion and a second protrusion, the first protrusion is away from the columnar body from the main body, the first protrusion is in contact with the surface of the cover plate body facing the connecting plate, the second protrusion is away from the columnar body from the first protrusion, extends into the matching groove, and contacts the surface of the matching groove facing the connecting plate, the dimension of the first protrusion along the thickness direction is greater than the dimension of the second protrusion along the thickness direction, and the surfaces of the first protrusion and the second protrusion facing the connecting plate are both in contact with the surface of the connecting plate facing the protrusion.

10. The cover plate assembly according to claim 9, wherein: The surfaces of the first protrusion and the second protrusion facing the connecting plate are located in the same plane; And / or, the cross-section of the second protrusion along the thickness direction is rectangular.

11. The cover plate assembly according to claim 9, wherein: A dimension of the second protrusion along the thickness direction is between 0.1 mm and 0.3 mm.

12. The cover plate assembly according to claim 8, wherein: The dimension of the matching groove along the thickness direction is between 0.05 mm and 0.25 mm; And / or, the inner diameter of the fitting groove is 0.2 mm to 0.4 mm larger than the outer diameter of the protrusion.

13. The cover plate assembly according to claim 8, wherein: The cross section of the pole sealing ring along the thickness direction is stepped.

14. A battery cell, characterized in that: It includes: case; The cover plate assembly according to any one of claims 1 to 13, 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 tabs of the electrode assembly are electrically connected to the connecting plate.

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