Battery cell cover plate and battery cell

Abstract

The invention relates to the technical field of batteries, in particular to a battery cell cover plate and a battery cell. The battery cell cover plate comprises a first mounting hole in which the terminal assembly is arranged on the cover plate main body and a second mounting hole in the first insulating part; the mounting piece is embedded in the first mounting hole, sleeves the pole and is spaced from the circumferential side wall of the pole; the second insulating piece is embedded in the second mounting hole and is arranged on one side, facing the interior of the battery cell, of the mounting piece; the first boss and the second boss are crimped in the second direction to form a compressed part; the size of the first boss in the second direction is A, the size of the second boss in the second direction is B, the size of the compression part in the second direction is C, and C / (A + B) is larger than or equal to 0.1 and smaller than or equal to 0.3. According to the invention, the terminal assembly is directly mounted on the cover plate main body and the first insulating part as a whole, so that the assembly process of the battery cell cover plate is simplified, the production efficiency is improved, the sealing property and the insulating property between the first boss and the second boss can be improved, and the safety performance of the battery cell is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cover and a battery. Background Art

[0002] Lithium-ion batteries have been widely used in electric vehicles due to their high energy density and long cycle life. A battery consists of a housing, a cover, and an electrode group. The housing and cover form a closed space for assembling the electrode group. The cover is provided with a pole to lead out the internal circuit. The pole needs to be assembled on the cover together with sealing rings, plastic parts, and other components to meet insulation and sealing requirements. As a result, the poles and cover need to be assembled through multiple steps in existing battery production lines. During the assembly process, the position of the housing or cover needs to be repeatedly adjusted, resulting in complex battery manufacturing processes and high costs. In addition, the sealing and insulation properties of the cover are crucial to the safety and life of the battery. Insufficient sealing can easily lead to electrolyte leakage, while excessive sealing can damage the sealing ring and cause electrolyte leakage. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a battery cell cover and a battery cell to solve the problems of multiple pole assembly steps on the existing battery cell cover, which leads to complex battery cell manufacturing process and high cost, and poor sealing performance of the battery cell cover, which easily causes electrolyte leakage, and poor insulation performance of the battery cell cover, which easily causes safety performance problems of the battery cell.

[0004] A first aspect of the present invention provides a cell cover, wherein the cell cover comprises:

[0005] The cover plate body is provided with a first mounting hole;

[0006] a first insulating member, disposed on a side of the cover body facing the interior of the battery cell, the first insulating member being provided with a second mounting hole;

[0007] A terminal assembly is provided in the first mounting hole and the second mounting hole; the terminal assembly includes a pole, a mounting member, and a second insulating member, the mounting member is embedded in the first mounting hole, the mounting member is sleeved on the pole and spaced from the circumferential side wall of the pole, and the second insulating member is embedded in the second mounting hole and is provided on a side of the mounting member facing the interior of the battery cell;

[0008] A first boss extending along the first direction toward the second insulating member is formed on the hole wall of the second mounting hole; a second boss extending along the first direction toward the first insulating member is formed on the circumferential side wall of the second insulating member, and the first boss and the second boss are crimped in the second direction to form a compression portion; before crimping, the size of the first boss in the second direction is A, in mm; before crimping, the size of the second boss in the second direction is B, in mm; after crimping, the size of the compression portion in the second direction is C, in mm; 0.1≤C / (A+B)≤0.3.

[0009] Preferably, a dimension of the compression portion in the first direction is L, 0.5 mm ≤ L ≤ 2 mm.

[0010] Preferably, the first boss is arranged on a side of the second mounting hole facing the outside of the battery cell, and the second boss is arranged on a side of the second insulating member facing the inside of the battery cell.

[0011] Preferably, the size of the first boss in the first direction is equal to the size of the second boss in the first direction.

[0012] Preferably, the second boss projects and covers a portion of the cover body in the second direction.

[0013] Preferably, a first mounting portion and a second mounting portion protruding along the first direction are formed at both ends of the pole in the second direction, and the second mounting portion is provided at one end of the pole facing the interior of the battery cell;

[0014] In the second direction, part of the first insulating member is sandwiched between the cover body and the second mounting portion, at least part of the second insulating member is sandwiched between the mounting member and the second mounting portion, and the compression portion is sandwiched between the cover body and the second mounting portion.

[0015] Preferably, the first mounting hole is formed as a stepped hole having a first step portion, a second step portion, and a third step portion arranged in sequence along the axial direction, the first step portion being provided on a side of the mounting hole facing the outside of the battery cell, and a dimension of the second step portion in the first direction being less than a dimension of the first step portion in the first direction and less than a dimension of the third step portion in the first direction;

[0016] The circumferential side wall of the mounting member is formed with a protruding first convex portion and a second convex portion, the second step portion is arranged around the first convex portion, and the third step portion is arranged around the second convex portion; the first convex portion and the second step portion are welded, and the protruding dimension of the first convex portion in the first direction is K1, 0.5mm≤K1≤1.5mm, and the distance between the surface of the first convex portion facing the outside of the battery cell and the surface of the mounting member facing the outside of the battery cell in the second direction is t, 0.1mm≤t≤1mm; the distance between the first step portion and the second step portion in the first direction is K2, 0.5mm≤K2≤1.5mm.

[0017] Preferably, a first convex portion protruding toward the outside of the battery cell is formed on the cover plate body, and a side of the first convex portion facing the inside of the battery cell is formed as a first concave portion;

[0018] A second convex portion protruding toward the outside of the battery cell is formed on the first insulating member, the second convex portion is embedded in the first concave portion, and a side of the second convex portion facing the inside of the battery cell is formed as a second concave portion;

[0019] In the second direction, a connection portion extending along the first direction is formed on one end of the pole facing the interior of the battery cell for mounting a pole lug;

[0020] In the second direction, the connecting portion and the second recess form an accommodating space, the tab is fixed in the accommodating space, and a size of the accommodating space in the second direction is n, 0.5 mm ≤ n ≤ 2 mm.

[0021] Preferably, the terminal assembly further comprises:

[0022] a third insulating member, sandwiched between the first mounting portion and the mounting member in the second direction;

[0023] A sealing member is sleeved on the pole; the sealing member has an axial portion and a radial portion, in the first direction, the axial portion is clamped between the hole wall of the first mounting hole and the circumferential side wall of the pole; in the second direction, the radial portion is clamped between the mounting member and the second mounting portion.

[0024] A second aspect of the present invention provides a battery cell, comprising the battery cell cover plate described in any of the above technical solutions.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The battery cell cover of the present invention has a cover body with a first mounting hole; a first insulating member is arranged on a side of the cover body facing the interior of the battery cell and has a second mounting hole; a terminal assembly is arranged in the first mounting hole and the second mounting hole; the terminal assembly includes a pole, a mounting member and a second insulating member, the mounting member is embedded in the first mounting hole and sleeved on the pole and spaced apart from the circumferential side wall of the pole, and the second insulating member is embedded in the second mounting hole and arranged on a side of the mounting member facing the interior of the battery cell; in this way, the terminal assembly is directly mounted on the cover body and the first insulating member as a whole, meeting the assembly requirements of battery cell covers of different sizes, simplifying the assembly process of the battery cell cover, and improving the production efficiency of the battery cell cover and the battery cell; a first boss extending along the first direction toward the second insulating member is formed on the hole wall of the second mounting hole; a second The circumferential side wall of the insulating part is formed with a second boss extending along the first direction toward the first insulating part, and the first boss and the second boss are crimped in the second direction to form a compression portion; the size of the first boss in the second direction is A, in mm; the size of the second boss in the second direction is B, in mm; the size of the compression portion in the second direction is C, in mm; 0.1≤C / (A+B)≤0.3, thereby improving the sealing between the first boss and the second boss, avoiding the leakage of electrolyte caused by insufficient or excessive sealing, thereby improving the insulation performance of the overlap between the first insulating part and the second insulating part, so that the first insulating part and the second insulating part separate the cover plate body and the mounting part from the interior of the battery cell, thereby forming effective insulation protection and ensuring the safety performance of the battery cell.

[0027] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 A schematic structural diagram of a cell cover provided in an embodiment of the present invention; Figure 2 for Figure 1 A cross-sectional view taken along AA in the middle; Figure 3 for Figure 2 Schematic diagram of the enlarged structure at P in the middle; Figure 4 for Figure 2 Schematic diagram of the enlarged structure at Q in the middle; Figure 5 A schematic structural diagram of a cell cover provided by an embodiment of the present invention from another perspective; Figure 6 A schematic structural diagram of the side of the cover plate body facing the inside of the battery cell provided in an embodiment of the present invention; Figure 7 A schematic structural diagram of the side of the first insulating member facing the outside of the battery cell in a battery cell cover provided by an embodiment of the present invention; Figure 8 A schematic structural diagram of a terminal assembly in a cell cover provided by an embodiment of the present invention; Figure 9 A cross-sectional view of the structure of the mounting member in the battery cover provided by an embodiment of the present invention; Figure 10 A cross-sectional view of a mounting member in a cell cover provided by an embodiment of the present invention; Figure 11 A cross-sectional view of a first mounting hole on a cover plate body in a cell cover plate provided in an embodiment of the present invention.

[0030] Icons: 10-cover plate body; 101-first convex portion; 102-first concave portion; 103-assembly groove; 11-first mounting hole; 111-first step portion; 112-second step portion; 113-third step portion; 12-pressure relief assembly; 13-exhaust hole; 20-first insulating member; 21-second mounting hole; 22-first boss; 201-second convex portion; 202-second concave portion; 23-assembly block; 30-pole; 31-first mounting portion; 32-second mounting portion; 33-connecting portion; 40-accommodating space; 50-mounting member; 51-first convex portion; 52-second convex portion; 60-second insulating member; 61-second boss; 70-compression portion; 80-third insulating member; 90-sealing member; 91-axial portion; 92-radial portion; D1-first direction; D2-second direction. DETAILED DESCRIPTION

[0031] The following detailed description is provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein. Rather, except for operations that must occur in a particular order, changes may be made that will be apparent upon understanding the disclosure of this application. Furthermore, descriptions of features known in the art may be omitted for clarity and brevity.

[0032] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0033] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, it may be directly “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on,” “directly connected to,” “directly coupled to,” “directly over,” or “directly covering” another element, there may be no other elements intervening therebetween.

[0034] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0035] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion in the examples described herein may also be referred to as a second member, component, region, layer, or portion without departing from the teachings of the examples.

[0036] For ease of description, spatial relational terms such as "above," "upper," "below," and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element would subsequently be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations "above" and "below," depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0037] The terms used herein are intended only to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0038] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0039] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0040] According to a first aspect of the present invention, a cell cover is provided, which specifically includes a cover body 10, a first insulating member 20 and a terminal assembly.

[0041] Hereinafter, the specific structure of the cell cover plate according to this embodiment as described above will be described.

[0042] In this embodiment, if Figures 1 to 4 and Figure 6 As shown, the cover plate body 10 can be a rectangular plate structure suitable for square shell batteries or blade batteries; alternatively, the cover plate body 10 can also be a circular plate structure. The cover plate body 10 is provided with a first mounting hole 11. The first mounting hole 11 is formed as a through hole that penetrates the cover plate body 10 in the thickness direction (i.e., the second direction D2 described below). The first mounting hole 11 can be circular, elliptical, or polygonal in shape. The number of first mounting holes 11 is the same as the number of poles 30 to be installed on the cover plate body 10.

[0043] It should be noted that, in this embodiment, one or more terminal assemblies are provided on the cover body 10; when only one terminal assembly is provided, the terminal assembly can be a positive terminal or a negative terminal; when multiple terminal assemblies are provided on the cover body 10, some of the terminal assemblies are negative terminals and the remaining terminal assemblies are positive terminals.

[0044] like Figure 2 、 Figure 3 and Figure 5As shown, the first insulating member 20 is arranged on the side of the cover body 10 facing the inside of the battery cell. The first insulating member 20 can be formed into a plate-like structure, preferably adapted to the shape of the cover body 10. For example, when the cover column is formed into a rectangular plate-like structure, the first insulating member 20 is correspondingly formed into a rectangular plate-like structure; a second mounting hole 21 is opened on the first insulating member 20, and the second mounting hole 21 is formed as a through hole that penetrates the thickness direction of the first insulating member 20 (that is, the second direction D2 described below). The second mounting hole 21 can be circular, elliptical or polygonal in shape; the second mounting hole 21 is arranged one-to-one with the first mounting hole 11, and the axis of the first mounting hole 11 is collinear with the axis of the second mounting hole 21.

[0045] In this embodiment, if Figure 2 As shown, the terminal assembly is arranged in the first mounting hole 11 and the second mounting hole 21, and part of the terminal assembly extends out of the side of the first mounting hole 11 facing the outside of the battery cell, and is used to connect with the power supply device or power device outside the battery cell; part of the terminal assembly extends out of the side of the second mounting hole 21 facing the inside of the battery cell and is used to connect with the pole ear on the pole group, thereby realizing the transmission of electrical energy.

[0046] Specifically, the terminal assembly includes a pole 30, a mounting member 50 and a second insulating member 60. The pole ear is mounted on the pole 30 to connect and realize the transmission of electric energy. The mounting member 50 is used to fix the pole 30 on the cover body 10. The mounting member 50 and the second insulating member 60 are both formed into an annular structure. The mounting member 50 is embedded in the first mounting hole 11. The mounting member 50 is sleeved on the pole 30 and is spaced from the circumferential side wall of the pole 30. The second insulating member 60 is embedded in the second mounting hole 21 and is arranged on the side of the mounting member 50 facing the interior of the battery cell to insulate and separate the mounting member 50 from the interior of the battery cell, thereby forming insulation protection. In this way, the terminal assembly can be directly mounted as a whole on the cover body 10 and the first insulating member 20, meeting the assembly requirements of battery cell covers of different sizes, simplifying the assembly process of the battery cell cover, and improving the production efficiency of the battery cell cover and the battery cell.

[0047] In this embodiment, if Figure 2 、 Figure 3 、 Figure 10 and Figure 11As shown, a first boss 22 extending along the first direction D1 toward the second insulating member 60 is formed on the hole wall of the second mounting hole 21; a second boss 61 extending along the first direction D1 toward the first insulating member 20 is formed on the circumferential side wall of the second insulating member 60. The first boss 22 and the second boss 61 are both formed into an annular structure. The first boss 22 and the second boss 61 are crimped in the second direction D2 to form a compression portion 70. The compression portion 70 can be understood as the compression amount generated by the first boss 22 and the second boss 61 being subjected to the extrusion force along the second direction D2, so that the size of the first boss 22 and / or the second boss 61 in the second direction D2 is thinned; before crimping, the first boss 22 in the second direction D 2 is A, in mm; the dimension of the second boss 61 in the second direction D2 before crimping is B, in mm; the dimension of the compression portion 70 in the second direction D2 after crimping is C, in mm; 0.1≤C / (A+B)≤0.3, thereby improving the sealing between the first boss 22 and the second boss 61, avoiding the leakage of electrolyte due to insufficient or excessive sealing, thereby improving the insulation performance of the overlap between the first insulating member 20 and the second insulating member 60, so that the first insulating member 20 and the second insulating member 60 separate the cover plate body 10 and the mounting member 50 from the interior of the battery cell, thereby forming effective insulation protection and ensuring the safety performance of the battery cell.

[0048] In a preferred embodiment, the first boss 22 is arranged on the side of the second mounting hole 21 facing the outside of the battery cell, and the second boss 61 is arranged on the side of the second insulating member 60 facing the inside of the battery cell, that is, the second boss 61 is arranged on the side facing the inside of the battery cell compared to the first boss 22, and the material hardness of the first insulating member 20 is greater than the material hardness of the second insulating member 60, so that the compression portion 70 is formed on the second boss 61, that is, after the first boss 22 and the second boss 61 are crimped, the thickness of the second boss 61 in the second direction D2 is reduced, and only the second boss 61 produces elastic deformation, thereby maximizing the improvement of the sealing and insulation effect and ensuring reliable insulation sealing. In other optional embodiments, the compression portion 70 is formed on the first boss 22 (that is, after the first boss 22 and the second boss 61 are crimped, only the first boss 22 produces elastic deformation), or part of the compression portion 70 is formed on the first boss 22 and the rest of the compression portion 70 is formed on the second boss 61 (that is, the first boss 22 and the second boss 61 both produce elastic deformation after crimping).

[0049] In a preferred embodiment, Figure 3 As shown, the dimension of the compression portion 70 in the first direction D1 is L, 0.5mm≤L≤2mm, so as to ensure that the first boss 22 and the second boss 61 have sufficient overlap, thereby improving the sealing effect and avoiding the dimension of L being too large to occupy the space of the cover body 10 in the width direction.

[0050] Further, if Figure 3 As shown, the size of the first boss 22 in the first direction D1 is equal to the size of the second boss 61 in the first direction D1, so that the end of the first boss 22 facing the second insulating member 60 in the first direction D1 can fit with the circumferential side wall of the second insulating member 60, and the end of the second boss 61 facing the first insulating member 20 in the first direction D1 can fit with the circumferential side wall of the first insulating member 20, thereby avoiding interference or excessive gap between the first boss 22 and the second boss 61 during crimping, which may cause reduced sealing and insulation.

[0051] Preferably, in this embodiment, Figure 3 As shown, the second boss 61 projects and covers part of the cover body 10 in the second direction D2 to ensure that the second insulating member 60 can block the gap between the cover body 10 and the mounting member 50, that is, the maximum size of the second insulating member 60 in the first direction D1 is greater than the maximum size of the first mounting hole 11 in the first direction D1, thereby improving the insulation protection and sealing reliability.

[0052] In this embodiment, the first direction D1 is arranged perpendicular to the second direction D2. The first direction D1 can be the width direction of the battery cover or the length direction of the battery cover (i.e., the radial direction of the pole 30), and the second direction D2 is the thickness direction of the battery cover (i.e., the axial direction of the pole 30).

[0053] The following tests were conducted on battery cell covers with different parameters A, B, C, and L to verify the reliability of the limiting conditions of 0.1≤C / (A+B)≤0.3 and 0.5mm≤L≤2mm. The test results are shown in Table 1.

[0054] Table 1

[0055]

[0056] As shown in Table 1, in Examples 1-1 to 1-5, C / (A+B) and L are respectively within the limited ranges of 0.1 to 0.3 and 0.5 to 2 mm, the first insulating member 20 and the second insulating member 60 are intact, the insulation test is qualified, and there is no electrolyte leakage, and the insulation and sealing meet the requirements of battery cell use; in Comparative Examples 1-1 and 1-2, the size of L is too small, resulting in insufficient compression in the first direction D1, and electrolyte leakage occurs; in Comparative Example 1-3, since the parameter C / (A+B) is too small, the compression in the second direction D2 is insufficient, and electrolyte leakage occurs; in Comparative Example 1-4, since the parameter C / (A+B) is too large, the first insulating member 20 and the second insulating member 60 are crushed, the insulation is unqualified, and electrolyte leakage occurs.

[0057] In addition, in this embodiment, Figure 5 and Figure 8 As shown, a recessed assembly groove 103 is formed on the side of the cover body 10 facing the interior of the battery cell, and a protruding assembly block 23 is formed on the side of the first insulating member 20 facing the cover body 10. The first insulating member 20 is hot-melt connected to the cover body 10 so that the assembly block 23 is embedded in the assembly groove 103. In this way, the cover body 10 and the first insulating member 20 are assembled first (that is, the cover body 10 and the first insulating member 20 are assembled into a whole first) and then the terminal assembly is assembled on the cover body 10, so that the terminal assembly can be adapted to cover bodies 10 of different sizes.

[0058] Preferably, if Figure 3 As shown, the assembly groove 103 is formed into a dovetail groove structure, and the assembly block 23 is formed into a shape complementary to the assembly groove 103, so that after the first insulating member 20 and the cover body 10 are hot-melt connected, the assembly block 23 is clamped in the assembly groove 103, thereby improving the connection reliability between the first insulating member 20 and the cover body 10.

[0059] In this embodiment, if Figures 1 to 4 and Figure 11 As shown, the first mounting hole 11 is formed as a stepped hole, which has a first step portion 111, a second step portion 112 and a third step portion 113 arranged in sequence along the axial direction, the first step portion 111 is arranged on the side of the mounting hole facing the outside of the battery cell, the third step portion 113 is arranged on the side of the mounting hole facing the inside of the battery cell, the second step portion 112 is arranged between the first step portion 111 and the third step portion 113, and the size of the second step portion 112 in the first direction D1 is less than the size of the first step portion 111 in the first direction D1 and less than the size of the third step portion 113 in the first direction D1.

[0060] Further, if Figures 1 to 4 、 Figure 10 and Figure 11 As shown, the circumferential side wall of the mounting member 50 is formed with a protruding first protrusion 51 and a second protrusion 52, and the size of the first protrusion 51 in the first direction D1 is smaller than the size of the second protrusion 52 in the first direction D1, so that before the cover body 10 and the mounting member 50 are welded, the mounting member 50 can be clamped in the first mounting hole 11, and the first insulating member 20 is clamped in the second mounting hole 21, thereby realizing the positioning of the terminal assembly and the cover body 10 before welding, thereby improving the welding quality.

[0061] Specifically, the second stepped portion 112 is disposed around the first protrusion 51. The first protrusion 51 and the second stepped portion 112 are welded together, so that the weld portion is located on the side of the second stepped portion 112 facing the exterior of the battery cell. The weld portion can be understood as a weld mark formed by a welding process, such as a laser weld mark. The weld portion is formed into a closed annular structure to ensure welding quality. The shape of the weld portion is adapted to the outer edge shape of the mounting member 50. For example, when the circumferential outer edge of the mounting member 50 is circular, the weld portion is correspondingly formed into a circular annular structure.

[0062] More specifically, if Figure 10 and Figure 11 As shown, the third step portion 113 is arranged around the second protrusion 52; the size of the second step portion 112 in the first direction D1 is b, and the size of the second protrusion 52 in the first direction D1 is a, b<a, so that before welding, the mounting member 50 is assembled into the first mounting hole 11 from the side of the battery cell cover facing the inner side, thereby meeting the assembly requirement of the electrode ear on the electrode group being mounted on the side of the battery cell cover facing the inner side of the battery cell, thereby facilitating the assembly of the electrode group and the battery cell cover before being installed into the shell.

[0063] In this embodiment, if Figure 4 As shown ( Figure 4 The schematic structure of the welding portion is omitted in the figure), the first step portion 111 and the side wall of the mounting member 50 form a welding space in the first direction D1; the first protrusion 51 is provided at the middle position of the mounting member 50 along the second direction D2, the protrusion dimension of the first protrusion 51 in the first direction D1 is K1, 0.5mm≤K1≤1.5mm, the distance between the surface of the first protrusion facing the outside of the battery cell and the surface of the mounting member 50 facing the outside of the battery cell in the second direction D2 is t, 0.1mm≤t≤1mm; the first step portion 111 and the second step portion 112 in the first direction The distance on D1 is K2, 0.5mm≤K2≤1.5mm, so as to avoid appearance defects caused by the welding portion extending to contact the side wall of the first step portion, or avoiding the welding portion extending beyond the size of the first protrusion 51 in the first direction D1, or avoiding the welding portion extending beyond the surface of the mounting member 50 and the cover body 10 facing the outside of the battery cell (that is, avoiding the welding portion protruding from the welding space in the first direction D1 or the second direction D2). It also avoids the situation where the dimensions of K1, K2, and t are too large and occupy space, causing an impact on the structural strength of the cover body 10.

[0064] The following tests are conducted on battery cell covers with different parameters K1, K2, and t to verify the reliability of the limiting conditions of 0.5mm≤K1≤1.5mm, 0.1mm≤t≤1mm, and 0.5mm≤K2≤1.5mm. The test results are shown in Table 2.

[0065] Table 2

[0066]

[0067] As shown in Table 2, in Examples 2-1 to 2-3, K1, K2 and t are all within the specified ranges of 0.5mm≤K1≤1.5mm, 0.1mm≤t≤1mm and 0.5mm≤K2≤1.5mm, and the test results are all qualified; while in Comparative Example 2-1, the dimensions of K1, K2 and t are too small, resulting in the welding portion protruding from the welding space, causing appearance defects; in Comparative Example 2-2, the structural strength of the cover plate body 10 is affected by the excessive dimensions of K1, K2 and t.

[0068] In this embodiment, if Figure 1 、 Figure 2 and Figure 6 As shown, the battery cover also includes a pressure relief component 12, which can be an explosion-proof valve or a combination of an explosion-proof valve and an explosion-proof patch. An exhaust hole 13 is provided on the cover body 10, and the explosion-proof valve is installed in the exhaust hole 13. The explosion-proof valve can be opened when the battery cover fails to achieve internal and external connectivity of the battery cell and reduce the risk of safety failure of the battery cell. The explosion-proof patch is arranged on the surface of the cover body 10 facing the outside of the battery cell and covers at least part of the explosion-proof valve to avoid the impact of components outside the battery cell on the pressure relief component, causing the pressure relief component to open prematurely.

[0069] In this embodiment, if Figure 1 、 Figure 2 、 Figures 5 to 7 As shown, a first convex portion 101 protruding toward the outside of the battery cell is formed on the cover body 10, and the size of the first convex portion 101 protruding toward the outside of the battery cell does not exceed the surface of the pole 30 facing the outside of the battery cell. The pressure relief assembly 12 is installed in the exhaust hole 13 opened on the first convex portion 101, and the side of the first convex portion 101 facing the inside of the battery cell is formed as a first concave portion 102; the first convex portion 101 can be formed from the side of the cover body 10 facing the inside of the battery cell through a stamping process so that the first convex portion 101 01 A concave first recess 102 is directly formed on the side facing the interior of the battery cell; a second convex portion 201 protruding toward the outside of the battery cell is formed on the first insulating member 20, the second convex portion 201 is embedded in the first recess 102, and the side of the second convex portion 201 facing the interior of the battery cell is formed as a second recess 202; in this way, the first insulating member 20 is attached to the surface of the cover body 10 facing the interior of the battery cell, thereby improving the insulation effect and increasing the space inside the battery cell for accommodating the electrode group, thereby improving the energy density of the battery cell.

[0070] Furthermore, in this embodiment, Figure 2 、 Figure 5 、 Figure 8 and Figure 9As shown, in the second direction D2, a connecting portion 33 extending along the first direction D1 is formed at one end of the pole 30 facing the interior of the battery cell, which is used to install the pole ear; preferably, the pole ear is arranged on the side of the connecting portion 33 facing the cover body 10, that is, the weld mark formed by welding the pole ear and the connecting portion 33 is located on the surface of the connecting portion 33 facing the cover body 10, thereby reducing the distance between the pole group and the pole 30 in the second direction D2, which helps to improve the energy density of the battery cell cover.

[0071] Furthermore, if Figure 2 As shown, in the second direction D2, the connecting portion 33 and the second recess 202 enclose an accommodating space 40, and the tab is fixed in the accommodating space 40. The size of the accommodating space 40 in the second direction D2 is n, 0.5mm≤n≤2mm, thereby ensuring smooth installation of the tab and avoiding damage to the tab. It can also avoid the size of n being too large, resulting in a reduction in the space for accommodating the pole group in the battery cell, which reduces the space utilization in the battery cell and affects the energy density of the battery cell.

[0072] Next, cell covers with different parameters n are tested to verify the reliability of the limiting condition of 0.5 mm ≤ n ≤ 2 mm. The test results are shown in Table 3.

[0073] Table 3

[0074]

[0075]

[0076] As shown in Table 3, in Examples 3-1 to 3-4, the parameter n is within the limited range of 0.5 mm to 2 mm, and the tabs are assembled smoothly without damage; while in Comparative Example 1-1, the tabs cannot be installed smoothly due to the small size of n, and are damaged by extrusion; in Comparative Example 1-2, the size of n is too large, resulting in reduced space utilization inside the battery cell, reduced energy density of the battery cell cover, and failure to meet the use requirements of the battery cell cover.

[0077] Preferably, in this embodiment, Figure 2 As shown, the connecting portion 33 is formed into a plate-like structure extending along the first direction D1, and at least part of the projection of the connecting portion 33 in the second direction D2 is located in the accommodating space 40, and the length of the connecting portion 33 projected in the accommodating space 40 in the first direction D1 is d, 10mm≤d≤50mm, which meets the assembly requirements of the tab and avoids the size of d being too large to block the exhaust hole 13, affecting the exhaust effect when the battery cell fails.

[0078] Preferably, in this embodiment, Figure 2As shown, in the second direction D2, the distance between the surface of the cover body 10 facing the outside of the battery cell except the first protrusion 51 and the surface of the pole 30 facing the inside of the battery cell (the surface of the pole 30 facing the inside of the battery cell can be the surface of the connecting portion 33 facing the inside of the battery cell or the surface of the second mounting portion 32 facing the inside of the battery cell as described below) is e, 2mm≤e≤8mm, which meets the strength, insulation and overcurrent requirements of the battery cell cover, and also avoids excessive occupation of the battery cell space in the second direction D2 due to the excessive size of e, which reduces the energy density of the battery cell.

[0079] In this embodiment, if Figure 2 and Figure 9 As shown, the pole 30 has a first mounting portion 31 and a second mounting portion 32 formed at both ends in the second direction D2, which protrude along the first direction D1. The first mounting portion 31 and the second mounting portion 32 can be formed into an annular structure. The first mounting portion 31 is provided at the end of the pole 30 facing the outside of the battery cell and is used to connect to a power supply device or an electrical device. The second mounting portion 32 is provided at the end of the pole 30 facing the inside of the battery cell and is used to connect to the terminal lug. The connecting portion 33 as described above is preferably formed by the side wall of the second mounting portion 32 extending outward along the first direction D1. The second mounting portion 32 can also sandwich the second insulating member 60 and the third insulating member 80 and the sealing member 90 described below between it and the first mounting portion 31. Specifically, in the second direction D2, part of the first insulating member 20 is sandwiched between the cover body 10 and the second mounting portion 32, at least part of the second insulating member 60 is sandwiched between the mounting member 50 and the second mounting portion 32, and the compression portion 70 is sandwiched between the cover body 10 and the second mounting portion 32.

[0080] In this embodiment, if Figures 1 to 9 As shown, the terminal assembly further includes a third insulating member 80 and a sealing member 90. In the second direction D2, the third insulating member 80 is sandwiched between the first mounting portion 31 and the mounting member 50, thereby separating the first mounting portion 31 from the mounting member 50, thereby providing insulation protection for the mounting member 50 and preventing short circuits caused by metal overlap. Preferably, a portion of the third insulating member 80 is disposed around the circumferential sidewalls of the first mounting portion 31, thereby enhancing the insulation protection effect of the third insulating member 80.

[0081] The seal 90 is an annular structure with elastic properties, allowing it to be fitted around the circumferential sidewalls of the terminal 30. Specifically, the seal 90 includes an axial portion 91 extending along the second direction D2 and a radial portion 92 extending along the first direction D1, forming a rotating body with an L-shaped cross-section. In the first direction D1, the axial portion 91 is sandwiched between the wall of the first mounting hole 11 and the circumferential sidewalls of the terminal 30. In the second direction D2, the radial portion 92 is sandwiched between the mounting member 50 and the second mounting portion 32, generating compression, thereby ensuring the sealing of the terminal assembly. Preferably, the top of the seal 90 is pressed against the third insulating member 80, causing the axial portion 91 to also be compressed, thereby enhancing the sealing strength of the seal 90.

[0082] In this embodiment, if Figures 1 to 9 As shown, the first insulating member 20 , the second insulating member 60 and the third insulating member 80 are all made of insulating materials, such as plastic members made of PP (polypropylene) or PPS (polyphenylene sulfide), as long as they can play the role of insulation protection.

[0083] Preferably, the sealing member 90 may be a fluororubber ring, which has insulating properties, thereby improving the insulating protection effect while ensuring sealing.

[0084] In an optional embodiment, the pole 30 is formed as a split structure, so that the pole 30 includes at least two parts arranged along its axial direction, and the first mounting portion 31 and the second mounting portion 32 are provided on different parts of the pole 30; in other optional embodiments, the pole 30 is formed as an integrated structure, the second insulating member 60, the sealing member 90, and the third insulating member 80 are sleeved on the pole 30 and axially limited by the second mounting portion 32, and then the first mounting portion 31 is folded outward so that it is crimped onto the third insulating member 80.

[0085] According to a battery cell cover provided by the present invention, the cover plate body is provided with a first mounting hole; the first insulating member is arranged on the side of the cover plate body facing the interior of the battery cell and is provided with a second mounting hole; the terminal assembly is arranged in the first mounting hole and the second mounting hole; the terminal assembly includes a pole, a mounting member and a second insulating member, the mounting member is embedded in the first mounting hole and is sleeved on the pole and spaced apart from the circumferential side wall of the pole, and the second insulating member is embedded in the second mounting hole and is arranged on the side of the mounting member facing the interior of the battery cell; in this way, the terminal assembly is directly mounted on the cover plate body and the first insulating member as a whole, meeting the assembly requirements of battery cell covers of different sizes, simplifying the assembly process of the battery cell cover plate, and improving the production efficiency of the battery cell cover plate and the battery cell; a first boss extending along the first direction toward the second insulating member is formed on the hole wall of the second mounting hole ; The circumferential side wall of the second insulating member is formed with a second boss extending along the first direction toward the first insulating member, and the first boss and the second boss are crimped in the second direction to form a compression portion; the size of the first boss in the second direction is A, in mm; the size of the second boss in the second direction is B, in mm; the size of the compression portion in the second direction is C, in mm; 0.1≤C / (A+B)≤0.3, thereby improving the sealing between the first boss and the second boss, avoiding the leakage of electrolyte caused by insufficient or excessive sealing, thereby improving the insulation performance of the overlap between the first insulating member and the second insulating member, so that the first insulating member and the second insulating member separate the cover plate body and the mounting member from the interior of the battery cell, thereby forming effective insulation protection and ensuring the safety performance of the battery cell.

[0086] According to a battery cell provided by the present invention, comprising the battery cell cover plate as described above, the assembly quality and efficiency of the battery cell cover plate are effectively improved, thereby improving the production efficiency of the battery cell, reducing costs, and improving the safety performance and service life of the battery cell.

[0087] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. A battery cover, characterized in that: The battery cover plate includes: The cover plate body is provided with a first mounting hole; a first insulating member, disposed on a side of the cover body facing the interior of the battery cell, the first insulating member being provided with a second mounting hole; A terminal assembly is provided in the first mounting hole and the second mounting hole; the terminal assembly includes a pole, a mounting member, and a second insulating member, the mounting member is embedded in the first mounting hole, the mounting member is sleeved on the pole and spaced from the circumferential side wall of the pole, and the second insulating member is embedded in the second mounting hole and is provided on a side of the mounting member facing the interior of the battery cell; A first boss extending along the first direction toward the second insulating member is formed on the hole wall of the second mounting hole; a second boss extending along the first direction toward the first insulating member is formed on the circumferential side wall of the second insulating member, and the first boss and the second boss are crimped in the second direction to form a compression portion; before crimping, the size of the first boss in the second direction is A, in mm; before crimping, the size of the second boss in the second direction is B, in mm; after crimping, the size of the compression portion in the second direction is C, in mm; 0.1≤C / (A+B)≤0.

3.

2. The cell cover according to claim 1, characterized in that: A dimension of the compression portion in the first direction is L, and 0.5 mm ≤ L ≤ 2 mm.

3. The cell cover according to claim 1, wherein: The first boss is arranged on a side of the second mounting hole facing the outside of the battery cell, and the second boss is arranged on a side of the second insulating member facing the inside of the battery cell.

4. The cell cover according to claim 1, wherein: The size of the first boss in the first direction is equal to the size of the second boss in the first direction.

5. The battery cell cover according to claim 1, characterized in that: The second boss projects in the second direction to cover a portion of the cover body.

6. The cell cover according to claim 1, characterized in that: The pole has a first mounting portion and a second mounting portion formed at both ends in the second direction, the first mounting portion protruding along the first direction, and the second mounting portion is provided at one end of the pole facing the interior of the battery cell; In the second direction, part of the first insulating member is sandwiched between the cover body and the second mounting portion, at least part of the second insulating member is sandwiched between the mounting member and the second mounting portion, and the compression portion is sandwiched between the cover body and the second mounting portion.

7. The battery cell cover according to claim 1, characterized in that: The first mounting hole is formed as a stepped hole, having a first step portion, a second step portion, and a third step portion arranged in sequence along the axial direction, the first step portion being provided on a side of the mounting hole facing the outside of the battery cell, and a dimension of the second step portion in the first direction being less than a dimension of the first step portion in the first direction and less than a dimension of the third step portion in the first direction; The circumferential side wall of the mounting member is formed with a protruding first convex portion and a second convex portion, the second step portion is arranged around the first convex portion, and the third step portion is arranged around the second convex portion; the first convex portion and the second step portion are welded, and the protruding dimension of the first convex portion in the first direction is K1, 0.5mm≤K1≤1.5mm, and the distance between the surface of the first convex portion facing the outside of the battery cell and the surface of the mounting member facing the outside of the battery cell in the second direction is t, 0.1mm≤t≤1mm; the distance between the first step portion and the second step portion in the first direction is K2, 0.5mm≤K2≤1.5mm.

8. The cell cover according to claim 1, characterized in that: The cover body is formed with a first convex portion protruding toward the outside of the battery cell, and a side of the first convex portion facing the inside of the battery cell is formed as a first concave portion; A second convex portion protruding toward the outside of the battery cell is formed on the first insulating member, the second convex portion is embedded in the first concave portion, and a side of the second convex portion facing the inside of the battery cell is formed as a second concave portion; In the second direction, a connection portion extending along the first direction is formed on one end of the pole facing the interior of the battery cell for mounting a pole lug; In the second direction, the connecting portion and the second recess form an accommodating space, the tab is fixed in the accommodating space, and a size of the accommodating space in the second direction is n, 0.5 mm ≤ n ≤ 2 mm.

9. The battery cell cover according to claim 6, characterized in that: The terminal assembly further comprises: a third insulating member, sandwiched between the first mounting portion and the mounting member in the second direction; A sealing member is sleeved on the pole; the sealing member has an axial portion and a radial portion, in the first direction, the axial portion is clamped between the hole wall of the first mounting hole and the circumferential side wall of the pole; in the second direction, the radial portion is clamped between the mounting member and the second mounting portion.

10. A battery cell, characterized in that: The invention comprises the battery cell cover according to any one of claims 1 to 9.

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