Battery cover and battery

Abstract

The present invention relates to the field of battery technology, and in particular to a cell cover and a cell. The cell cover comprises: a cover body is provided with a first mounting hole; a pole comprises a first column portion and a second column portion arranged in sequence along the axial direction; the first column portion is inserted into the first mounting hole; an adapter is arranged on the side of the cover body facing the inside of the cell, and the adapter is provided with a second mounting hole for the first column portion to extend into; the adapter is welded to the first column portion to form a welding portion, and a sealing member is sandwiched between the cover body and the adapter; 10%≤()≤50%; when 10%≤()<25%,; when 25%≤()≤50%,. The present invention can ensure that the welding strength of the pole and the adapter is greater than or equal to the compression rebound force of the seal, and avoid the pole falling off from the cell cover, thereby reducing the risks of short circuit and failure of the cell, and ensuring the safety of the cell.

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] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the performance and safety of lithium-ion batteries are increasing.

[0003] The cover is a key component of lithium-ion batteries. The cover is equipped with poles and riveted blocks. The poles are mostly machined, with low material utilization, high processing costs, and great processing difficulty. The poles and riveted blocks are pre-riveted and then connected by laser welding, which is a complex process with high process costs. In addition, the part where the existing riveted block is connected to the pole is located outside the cover. The battery cell is often subjected to extrusion force in the application of modules or whole packages, that is, the force pointing from the outside of the cover perpendicular to the inside. The risk of the pole falling off the riveted block is high, which is easy to cause short circuit overlap. In severe cases, it will cause the whole package to fail or even catch fire and explode, causing safety accidents. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a battery cell cover and a battery cell to solve the problem that the poles on the existing battery cell cover are installed using riveted blocks, which has the characteristics of high cost, complex processing, low efficiency, and the poles are prone to fall off from the riveted blocks when subjected to extrusion pressure, thereby causing battery cell short circuit, failure, and even safety accidents.

[0005] A first aspect of the present invention provides a cell cover, wherein the cell cover comprises:

[0006] The cover plate body is provided with a first mounting hole;

[0007] The pole comprises a first column portion and a second column portion arranged in sequence along the circumferential direction thereof, wherein the circumferential side wall of the second column portion protrudes from the circumferential side wall of the first column portion; the first column portion is passed through the first mounting hole, and the second column portion is arranged on a side of the cover plate body facing the outside of the battery cell;

[0008] An adapter is arranged on a side of the cover plate body facing the inside of the battery cell, and the adapter is provided with a second mounting hole for the first column portion to extend therein; the adapter is welded to the first column portion to form a welding portion, and the penetration depth of the welding portion in the first direction is c, in mm;

[0009] A seal is clamped between the cover plate body and the adapter. The dimension of the seal in the first direction before compression is a, with the unit of mm, and the dimension of the seal in the first direction after compression is b, with the unit of mm; the compression amount of the seal is ;

[0010] 10% ≤ ( ) ≤ 50%;

[0011] When 10% ≤ ( ) < 25%, ;

[0012] When 25% ≤ ( ) ≤ 50%, ;

[0013] Wherein, A is the perimeter of the welding track of the welding part, with the unit of mm, is the tensile strength of the material of the adapter, with the unit of MPa, and S is the contact area between the seal and the cover plate body, with the unit of mm 2 .

[0014] Preferably, a fillet is formed at the connection of the first cylindrical part and the second cylindrical part, and the radius dimension of the fillet is R, 0mm < R ≤ 2mm.

[0015] Preferably, the dimension of the first cylindrical part away from the second cylindrical part decreases in the second direction to form a first support part arranged at an angle to the axis of the first cylindrical part. A second support part with an increasing dimension in the second direction is formed on the side of the second mounting hole facing the pole column, and the first support part abuts against the second support part.

[0016] Preferably, the dimension of the adapter in the first direction is f, 0.5mm ≤ f ≤ 3mm;

[0017] The second mounting hole is formed as a stepped hole. The second mounting hole includes a first step part and a second step part. The dimension of the first step part in the second direction is larger than that of the second step part in the second direction. The first step part is arranged on the side of the adapter facing the inside of the battery cell. The first cylindrical part extends into the second step part. The dimension of the first step part in the first direction is d, 0mm < d < f mm; the distance between the hole wall of the first step part and the hole wall of the second step part in the second direction is e, 0mm < e < 3mm.

[0018] Preferably, the part of the first cylindrical part connected to the adapter is made of the same material as the adapter.

[0019] Preferably, along the first direction, the pole is formed into a split structure including a first pole portion and a second pole portion, and the first pole portion and the second pole portion are made of different materials.

[0020] Preferably, the first pole portion includes a plate portion and a protrusion arranged on a side of the plate portion facing the second pole portion; a groove is formed on the side of the second pole portion facing the first pole portion, and an opening of the groove extends radially outward from the side wall of the second pole portion to form a flange portion, and the flange portion and the plate portion together form the second column portion, and the protrusion is embedded in the groove to jointly form the first column portion.

[0021] Preferably, the first pole portion is formed as a plate-like structure spaced apart from the cover plate body along the first direction; the second pole portion is formed with a first boss portion protruding from the circumferential side wall of the first column portion at one end facing the first pole portion, and the first boss portion and the first pole portion together form the second column portion.

[0022] Preferably, the first pole portion includes the second column portion and a second boss portion protruding outward from one end of the second column portion facing the first column portion, the second pole portion is formed into a columnar structure, and the second boss portion and the second pole portion together form the first column portion.

[0023] 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.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The cell cover of the present invention eliminates the riveting block structure in the traditional cell cover, and an adapter is added on the side of the cover body facing the inside of the cell. The adapter is welded to the first column part of the pole penetrating the first mounting hole to form a welding part, which is simple to assemble, has high assembly efficiency and low cost; the sealing member is sandwiched between the adapters of the cover body, and the relationship between the compression amount of the sealing member, the penetration depth of the welding part and the circumference of the welding track, the tensile strength of the material of the adapter and the contact area between the sealing member and the cover body is limited, that is, 10%≤( )≤50%; when 10%≤( ) < 25%, ; When 25%≤( )≤50%, ; Thereby ensuring that the welding strength between the pole and the adapter is greater than or equal to the compression rebound force of the seal, thereby ensuring reliable assembly of the pole, avoiding the pole from falling off the battery cover, reducing the risk of short circuit and failure of the battery, and ensuring the safe use of the battery.

[0026] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of the structure of a cell cover plate provided in an embodiment of the present invention;

[0029] Figure 2 A schematic structural diagram of a cell cover provided by an embodiment of the present invention from another perspective;

[0030] Figure 3 An exploded view of the structure of a cell cover provided by an embodiment of the present invention;

[0031] Figure 4 A schematic structural diagram of a cell cover provided by an embodiment of the present invention from another perspective;

[0032] Figure 5 A cross-sectional view of the structure of a cell cover provided by an embodiment of the present invention;

[0033] Figure 6 for Figure 5 A schematic diagram of the enlarged structure at A in the middle;

[0034] Figure 7 A schematic diagram of the assembly structure of a cover plate body and a sealing member in a cell cover plate provided by an embodiment of the present invention;

[0035] Figure 8 A schematic diagram of the structure of a sealing member in a cell cover provided by an embodiment of the present invention;

[0036] Fig. 9 A schematic diagram of the contact area between the cover plate body and the sealing member in the battery cell cover plate provided by an embodiment of the present invention;

[0037] Fig.10 A schematic diagram of the structure of a transition piece in a cell cover provided by an embodiment of the present invention;

[0038] Fig.11 A schematic structural diagram of a transition piece in a cell cover provided by an embodiment of the present invention from another viewing angle;

[0039] Fig.12A structural cross-sectional view of a transition piece in a cell cover provided by an embodiment of the present invention;

[0040] Fig.13 A schematic diagram of a first structure of a pole in a cell cover provided by an embodiment of the present invention;

[0041] Fig.14 for Fig.13 A cross-sectional view of the structure of the pole in FIG.

[0042] Fig.15 A schematic diagram of a second structure of a pole in a cell cover provided by an embodiment of the present invention;

[0043] Fig.16 for Fig.15 A cross-sectional view of the structure of the pole in FIG.

[0044] Fig.17 A third structural schematic diagram of a pole in a cell cover provided by an embodiment of the present invention;

[0045] Fig.18 for Fig.17 A cross-sectional view of the structure of the pole in FIG.

[0046] Fig.19 A fourth structural schematic diagram of a pole in a cell cover provided by an embodiment of the present invention;

[0047] Fig. 20 for Fig.19 A cross-sectional view of the structure of the pole in FIG.

[0048] Fig.21 A schematic diagram of the assembly structure of a cell cover and a cell shell provided in an embodiment of the present invention.

[0049] Icons: 10-cover body; 11-first mounting hole; 111-first supporting portion; 20-pole; 21-first column portion; 22-second column portion; 201-first pole portion; 202-second pole portion; 203-protrusion; 2031-plate portion; 204-groove; 205-flanged portion; 206-first boss portion; 207-second boss portion; 30-adapter; 31-second mounting hole; 310-second supporting portion; 311-first step portion; 312-second step portion; 40-sealing member; 51-first insulating member; 52-second insulating member; 60-welding portion; 101-first cover plate; 102-second cover plate; 70-shell; D1-first direction; D2-second direction. DETAILED DESCRIPTION

[0050] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0051] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0052] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” 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 bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0053] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0054] 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 only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0055] 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 include different orientations of the device in use or operation in addition to the orientation 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 will subsequently be "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations 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.

[0056] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0057] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0058] The features of the examples described herein may 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.

[0059] According to a first aspect of the present invention, a cell cover is provided, which specifically includes a cover body 10 , a pole 20 , a transition piece 30 and a sealing piece 40 .

[0060] Hereinafter, the specific structure of the cell cover plate as described above according to this embodiment will be described.

[0061] In this embodiment, if Figures 1 to 6As shown, the cover body 10 is formed into a plate-like structure. For example, when the battery cell is a square battery cell or a blade battery cell, the cover body 10 can be formed into a rectangular plate-like structure; for example, when the battery cell is a cylindrical battery cell, the cover body 10 can be formed into a circular plate-like structure; a first mounting hole 11 is opened on the cover body 10, and the first mounting hole 11 is formed into a through hole structure that passes through the cover body 10; the first mounting hole 11 can be a circular hole, a rectangular hole, or a through hole structure such as a runway-shaped hole with semicircular ends and a rectangular middle.

[0062] like Figure 6 , Figures 13 to 20 As shown, the pole 20 includes a first column portion 21 and a second column portion 22 arranged in sequence along its axial direction. The second column portion 22 and the first column portion 21 can be arranged up and down along the axial direction of the pole 20. The circumferential side wall of the second column portion 22 protrudes from the circumferential side wall of the first column portion 21, so that the axial cross-section of the pole 20 is formed into a T-shaped structure. It should be noted that the axial cross-section of the pole 20 is a cross-section that coincides with the axis of the pole 20; wherein the first column portion 21 is penetrated through the first mounting hole 11, and the second column portion 22 is arranged on the side of the cover body 10 facing the outside of the battery cell.

[0063] Furthermore, in the present embodiment, the first column portion 21 is formed as a columnar structure, such as a polygonal body or a cylindrical structure, and the second column portion 22 is formed as a plate-like structure arranged parallel to the cover body 10. The projection of the second column portion 22 on the cover body 10 can be circular, elliptical, polygonal, or a runway shape with semicircular ends and a rectangular middle. Similarly, the cross section of the first column portion 21 perpendicular to the axis of the pole 20 (the cross section is parallel to the plane where the cover body 10 is located) can also be formed as a circular, elliptical, polygonal, or a runway shape with semicircular ends and a rectangular middle. The second column portion 22 and the first column portion 21 are preferably runway-shaped structures to facilitate the molding of the pole 20 and the structure can prevent the pole 20 from twisting relative to the cover body 10.

[0064] like Figure 6 , Figures 10 to 12 As shown, the adapter 30 is arranged on the side of the cover body 10 facing the inside of the battery cell, and the adapter 30 is provided with a second mounting hole 31 for the first column portion 21 to extend into. The adapter 30 can be formed into a plate-like structure arranged parallel to the cover body 10. The adapter 30 can be a circular, elliptical or polygonal plate-like structure, preferably a rectangular shape, so that the pole ear inside the battery cell can be connected to the adapter 30 to realize electrical transmission; the adapter 30 is welded to the first column portion 21 to form a welding portion 60. Specifically, the welding portion 60 is formed between the outer wall of the first column portion 21 and the hole wall of the second mounting hole 31, and the welding portion 60 is formed into a closed annular structure.

[0065] like Figures 1 to 9As shown, the seal 40 is formed into an annular structure. The seal 40 can be an elastic sealing ring. In the first direction D1, the seal 40 is sandwiched between the cover body 10 and the adapter 30 to play a sealing and insulating role; the seal 40 is compressed to achieve sealing. The material of the seal 40 can be fluororubber with a melting point of about 350°C; the size of the seal 40 in the first direction D1 before compression is a, in mm, the size of the seal 40 in the first direction D1 after compression is b, in mm, and the compression amount of the seal 40 is It should be noted that the first direction D1 is the thickness direction of the cover body 10.

[0066] In this embodiment, the preferred range of the compression amount of the seal 40 is 10%≤( )≤50%; thus, the sealing reliability of the sealing member 40 is ensured. Next, an airtightness test is performed on the sealing member 40 under different compression amounts. The test results are shown in Table 1.

[0067] Table 1

[0068]

[0069] It can be seen from Table 1 above that in Examples 1-1 to 1-3, the compression amount of the seal 40 is within 10%≤( )≤50%, the air tightness test is qualified, and the comprehensive performance of Example 1-2 is better than that of Example 1-3; in Comparative Example 1-1, the seal 40 has no compression, resulting in seal failure. In Comparative Example 1-2, the compression of the seal 40 is less than 10%, and there is still a risk of failure due to insufficient compression; in Comparative Example 1-3, the air tightness test is qualified due to a large compression, but the compression is too large, the seal 40 is prone to aging, the service life is short, and it is even easy to crack the sealing ring, resulting in seal failure; in Comparative Example 1-4, the compression of 100% is an illusion, which does not exist in actual production applications.

[0070] Furthermore, when 10%≤( ) < 25%, the following relationship is satisfied: ; When 25%≤( )≤50%, the following relationship is satisfied: ; Wherein, c is the penetration depth of the welding portion 60 in the first direction D1, in mm; A is the circumference of the welding track of the welding portion 60, in mm, is the tensile strength of the material of the adapter 30, in MPa, and S is the contact area between the seal 40 and the cover body 10, in mm 2, under the above-defined relationship, it can be ensured that the welding strength between the terminal post 20 and the adapter 30 is greater than or equal to the resilience of the seal 40 after compression, making the installation structure of the terminal post 20 reliable, ensuring that the terminal post 20 is firmly assembled on the cell cover plate, avoiding the situation where the terminal post 20 falls off the cell cover plate, thereby reducing risks such as short circuits and failures of the cell and ensuring the safe use of the cell.

[0071] The following conducts experimental verification on the above-defined relationship. The experimental results are shown in Table 2-1 and Table 2-2. Among them, Table 2-1 shows the situation where the compression amount of the seal 40 is within the range of 10% ≤ ( ) < 25%, and Table 2-2 shows the situation where the compression amount of the seal 40 is within the range of 25% ≤ ( ) ≤ 50%.

[0072] Table 2-1

[0073]

[0074] Table 2-2

[0075]

[0076] Note: The symbol " / " in Table 2-1 and Table 2-2 represents "or". For example, " / =" represents less than, greater than, or equal to.

[0077] Referring to Table 2-1 and Table 2-2 above, when 10% ≤ ( ) < 25%, the following relationship is satisfied: ; when 25% ≤ ( ) ≤ 50%, the following relationship is satisfied: Under the defined conditions, the resilience corresponding to the compression amount of the seal 40 is less than or equal to the welding connection strength between the terminal post 20 and the adapter 30, that is, less than or equal to the force that the penetration depth of the welding between the adapter 30 and the terminal post 20 can support the seal 40, which can ensure the reliability and stability of the installation structure of the terminal post 20, ensure that the terminal post 20 is firmly assembled on the cell cover plate, avoid the situation where the terminal post 20 falls off the cell cover plate, thereby reducing risks such as short circuits and failures of the cell and ensuring the safe use of the cell.

[0078] In addition, in this embodiment, as Figures 13 to 20 shown, a fillet is formed at the connection between the first cylindrical portion 21 and the second cylindrical portion 22. The fillet is formed into a structure that is recessed towards the inside of the terminal post 20. The radius dimension of the fillet is R, where 0 mm < R ≤ 2 mm. In this way, it is avoided that the mold is not easy to process and is prone to die collapse, or the dimension of R exceeds 2 mm, resulting in the fillet overly occupying the length and width dimension space; in a preferred embodiment, R = 0.8 mm.

[0079] Furthermore, in this embodiment, if Figures 12 to 20 As shown, the end of the first column portion 21 away from the second column portion 22 has a reduced size in the second direction D2 to form a first support portion 111 arranged at an angle to the axial direction of the first column portion 21, and the second mounting hole 31 has a second support portion 310 with an increased size in the second direction D2 formed on the side facing the pole 20, and the first support portion 111 abuts against the second support portion 310, so that the adapter 30 supports the pole 20 to a certain extent. In an optional embodiment, as Figures 12 to 20 As shown, the first support portion 111 can be arranged to be axially inclined relative to the first cylindrical portion 21, so that the first support portion 111 forms a funnel-shaped annular surface, and the shape of the second support portion 310 is adapted to the shape of the first support portion 111, that is, the second support portion 310 forms a funnel-shaped hole structure.

[0080] In this embodiment, the second supporting portion 310 is disposed on a side of the adapter 30 facing the cover body 10 .

[0081] It should be noted that, in the present embodiment, the second direction D2 is perpendicular to the first direction D1. For example, when the cover body 10 is formed as a rectangular plate structure, the second direction D2 may be the length direction of the cover.

[0082] In this embodiment, if Fig.12 As shown, the dimension of the adapter 30 in the first direction D1 is f, 0.5mm≤f≤3mm, so as to avoid the welding temperature affecting the seal 40 when the dimension of f is less than 0.5mm, causing the adapter 30 to have insufficient strength and be easily deformed, or to avoid the problem of heavy weight and high cost of the adapter 30 when the dimension of f is greater than 3mm; preferably, f=2mm.

[0083] Furthermore, in this embodiment, if Figures 10 to 12As shown, the second mounting hole 31 is formed as a stepped hole. The second mounting hole 31 includes a first stepped portion 311 and a second stepped portion 312. The dimension of the first stepped portion 311 in the second direction D2 is greater than that of the second stepped portion 312 in the second direction D2. The first stepped portion 311 is disposed on the side of the adapter 30 facing the inside of the battery cell. The first cylindrical portion 21 extends into the second stepped portion 312, and the pole 20 is welded to the second stepped portion 312. The dimension of the first stepped portion 311 in the first direction D1 is d, where 0 mm < d < f mm. The formation of the second mounting hole 31 as a stepped hole structure is beneficial for accommodating the welding portion 60. The welding portion 60 has a certain height. Therefore, the dimension of d needs to be greater than 0 and less than the thickness dimension of the adapter 30. Preferably, d = 0.3 mm. The distance between the hole wall of the first stepped portion 311 and the hole wall of the second stepped portion 312 in the second direction D2 is e, where 0 mm < e < 3 mm. As described above, the formation of the second mounting hole 31 as a stepped hole structure is beneficial for accommodating the welding portion 60. The welding portion 60 has a certain width. Therefore, the dimension of e needs to be greater than 0. If the dimension of e exceeds 3 mm, it will affect the structural strength of the adapter 30. Preferably, e = 1.2 mm.

[0084] In this embodiment, as Fig.12 shown, the first stepped portion 311 and the second support portion 310 are respectively located on both sides of the second stepped portion 312 in the first direction D1. That is, in the axial direction of the second mounting hole 31, the second stepped portion 312 is disposed between the first stepped portion 311 and the second support portion 310.

[0085] In this embodiment, the portion of the first cylindrical portion 21 connected to the adapter 30 is made of the same material as the adapter 30, so that the main body portion and the adapter 30 are reliably welded. The material of the adapter 30 can be copper material. For example, it is preferably in the Cu T2 state. At this time, as described above is the tensile strength of Cu T2. Generally, ≥195 MPa; the material of the adapter 30 can also be aluminum material. For example, it is preferably in the AL 1060 H18 state. At this time, as described above is the tensile strength of AL 1060 H18. Generally, ≥125 MPa.

[0086] In the first implementation manner, as Figures 13 to 18 shown, along the first direction D1, the pole 20 is formed as a split structure including a first pole portion 201 and a second pole portion 202. The materials of the first pole portion 201 and the second pole portion 202 are different. That is, the pole 20 is formed of a composite material. The composite pole 20 can be formed by stamping, upsetting, machining, or a combination of multiple processes from a composite material plate. Among them, the upsetting process is preferably used, and the process is simple and the cost is low.

[0087] When the pole 20 is formed into a two-part split structure including a first pole part 201 and a second pole part 202, the three structures are included but not limited to the following. In the first embodiment described below, the first pole part 201 in the three structures can be made of aluminum material, and the second pole part 202 can be made of copper material.

[0088] The first structure is Fig.13 and Fig.14 As shown, the first pole part 201 includes a plate part 2031 and a protrusion 203 arranged on the side of the plate part 2031 facing the second pole part 202; a groove 204 is formed on the side of the second pole part 202 facing the first pole part 201, and a flange part 205 extending radially outward along the side wall of the second pole part 202 is formed at the opening of the groove 204. The flange part 205 can be an annular plate structure, and the flange part 205 extends to the edge of the first pole part 201. The flange part 205 and the plate part 203 are connected. 1 is fitted so that the flange portion 205 and the plate portion 2031 jointly form a second column portion 22 arranged on the side of the cover plate body 10 facing the outside of the battery cell, and the protrusion 203 is embedded in the groove 204 so that at least part of the protrusion 203 and the groove wall of the groove 204 jointly form the first column portion 21, that is, the separation surface between the first pole portion 201 and the second pole portion 202 can be formed on the second column portion 22 and the first column portion 21, and the second column portion 22 and the first column portion 21 are both made of copper-aluminum composite materials.

[0089] The second structure is Fig.15 and Fig.16 As shown, the first pole portion 201 is formed as a plate-like structure spaced apart from the cover body 10 along the first direction D1, and the first pole portion 201 is preferably arranged parallel to the cover body 10; the second pole portion 202 is formed with a first boss portion 206 protruding from the circumferential side wall of the first column portion 21 at one end facing the first pole portion 201, and the first boss portion 206 is arranged on the side of the cover body 10 facing the outside of the battery cell, and the first boss portion 206 and the first pole portion 201 together form the second column portion 22, that is, the dividing surface between the first pole portion 201 and the second pole portion 202 can be formed on the second column portion 22, the second column portion 22 is a copper-aluminum composite material, and the first column portion 21 is a copper material.

[0090] The third structure is Fig.17 and Fig.18As shown, the first pole portion 201 includes a second column portion 22 and a second boss portion 207 protruding outward from one end of the second column portion 22 facing the first column portion 21, that is, the second boss portion 207 extends toward the second pole portion 202, and the second pole portion 202 is formed as a columnar structure. The second boss portion 207 and the second pole portion 202 jointly form the first column portion 21 penetrating into the second mounting hole 31, that is, the dividing surface between the first pole portion 201 and the second pole portion 202 can be formed on the first column portion 21, the second column portion 22 is made of aluminum material, and the first column portion 21 is made of copper-aluminum composite material.

[0091] In a second embodiment, if Fig.19 and Fig. 20 In the fourth structure shown, the pole 20 is formed as an integral structure, and the pole 20 of the integral structure may be made of aluminum.

[0092] In this embodiment, if Fig.21 As shown, when the battery cell is a blade battery cell, the battery cell cover includes a first cover 101 and a second cover 102, and the first cover 101 and the second cover 102 are respectively arranged on both sides of the battery cell housing 70, and one of the first cover 101 and the second cover 102 is a positive electrode cover, and the other is a negative electrode cover, wherein the pole 20 on the positive electrode cover is a positive pole pole, and the positive pole pole can constitute a positive terminal, and the positive pole pole is connected to the positive terminal inside the battery cell, and the pole 20 on the negative electrode cover is a negative pole pole, and the negative pole pole can constitute a negative terminal, and the negative pole pole is connected to the negative terminal inside the battery cell. When the adapter 30 and the portion of the pole 20 connected to the adapter 30 are made of aluminum, the battery cell cover is suitable for the positive electrode cover, and when the adapter 30 and the portion of the pole 20 connected to the adapter 30 are made of copper, the battery cell cover is suitable for the negative electrode cover.

[0093] When the positive pole and the negative pole are arranged on the cell cover at the same time, the positive pole and the adapter 30 connected to the positive pole are made of aluminum, and the negative pole and the adapter 30 connected to the negative pole are made of copper.

[0094] The relationship between the above four types of pole 20 structures and the adapters 30 of different materials to match different battery cover plates is shown in Table 3, where Scheme 1 is as follows Fig.13 and Fig.14 The first structure shown; Scheme 2 is as follows Fig.15 and Fig.16 The second structure shown, Scheme 3 is as follows Fig.17 and Fig.18 The third structure shown in FIG. 1 is a structure in which the first pole portion 201 is made of aluminum and the second pole portion 202 is made of copper. Fig.19 and Fig. 20In the fourth structure shown, the pole 20 is an integrated structure, and the pole 20 is made of aluminum.

[0095] Table 3

[0096]

[0097] Note: “ / ” in Table 3 means or.

[0098] As can be seen from Table 3, the material of the adapter 30 in the positive electrode cover or the positive electrode terminal is copper, and the material of the portion connected to the pole 20 (when the pole 20 is a split structure, this portion is the second pole portion 202) is copper; the material of the adapter 30 in the negative electrode cover or the negative electrode terminal is aluminum, and the material of the portion connected to the pole 20 is aluminum.

[0099] In addition, in this embodiment, Figures 1 to 6 As shown, the cell cover also includes a first insulating member 51 and a second insulating member 52. In the first direction D1, the first insulating member 51 is arranged between the second column portion 22 of the pole 20 and the cover body 10 to insulate the pole 20 and the cover body 10. The material of the first insulating member 51 can be polyphenylene sulfide (PPS) or liquid crystal polymer (LCP) and other materials, preferably PPS. The resistance range of the first insulating member 51 can be 5~100000Ω, which is suitable for the positive terminal or the positive cover; the resistance range of the first insulating member 51 can also be greater than 200MΩ, which is suitable for the negative terminal or the negative cover. In the first direction D1, at least part of the second insulating member 52 is arranged between the adapter 30 and the cover body 10 to insulate the adapter 30 and the cover body 10. The material of the second insulating member 52 can be polypropylene (PP) with a melting point of about 160°C.

[0100] According to a cell cover provided by the present invention, the riveted block structure in the traditional cell cover is omitted, and an adapter is added on the side of the cover body facing the inside of the cell, and the adapter is welded to the first column part of the pole penetrating the first mounting hole to form a welding part, which is simple to assemble, has high assembly efficiency and low cost; the sealing member is sandwiched between the adapters of the cover body, and the relationship between the compression amount of the sealing member, the penetration depth of the welding part and the circumference of the welding track, the tensile strength of the material of the adapter and the contact area between the sealing member and the cover body is limited, that is, 10%≤( )≤50%; when 10%≤( ) < 25%, ; When 25%≤( )≤50%, ; Thereby ensuring that the welding strength between the pole and the adapter is greater than or equal to the compression rebound force of the seal, thereby ensuring reliable assembly of the pole.

[0101] A battery cell provided by the present invention includes the battery cell cover as described above, and the pole and the adapter are firmly and reliably installed to prevent the pole from falling off the battery cell cover, thereby reducing the risks of short circuit and failure of the battery cell and ensuring the safe use of the battery cell.

[0102] 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 protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery cell cover, characterized in that: The cell cover plate includes: A cover plate main body, which is provided with a first mounting hole; A pole post, which includes a first cylinder part and a second cylinder part arranged in sequence along its axial direction, and the circumferential side wall of the second cylinder part protrudes from the circumferential side wall of the first cylinder part; the first cylinder part penetrates through the first mounting hole, and the second cylinder part is arranged on the side of the cover plate main body facing the outside of the cell; An adapter, which is arranged on the side of the cover plate main body facing the inside of the cell, and the adapter is provided with a second mounting hole for the first cylinder part to extend into; the adapter is welded to the first cylinder part to form a welded part, and the penetration depth of the welded part in the first direction is c, with the unit of mm; The sealing member is sandwiched between the cover plate body and the adapter. The dimension of the sealing member in the first direction before compression is a, in mm, and the dimension of the sealing member in the first direction after compression is b, in mm. The compression amount of the sealing member is ; 10%≤（ ）≤50%； When 10%≤( ) < 25%, ; When 25%≤( )≤50%, ; Wherein, A is the circumference of the welding track of the welding part, in mm, is the tensile strength of the material of the adapter, in MPa, and S is the contact area between the seal and the cover body, in mm 2 .

2. The cell cover plate according to claim 1, characterized in that: A fillet is formed at the connection between the first cylinder part and the second cylinder part, and the radius dimension of the fillet is R, where 0mm < R ≤ 2mm.

3. The cell cover plate according to claim 1, characterized in that: One end of the first cylinder part away from the second cylinder part has a reduced dimension in the second direction to form a first support part arranged at an angle to the axial direction of the first cylinder part. A second support part with an increased dimension in the second direction is formed on the side of the second mounting hole facing the pole post, and the first support part abuts against the second support part.

4. The cell cover plate according to claim 1, characterized in that: The dimension of the adapter in the first direction is f, where 0.5mm ≤ f ≤ 3mm; The second mounting hole is formed as a stepped hole. The second mounting hole includes a first step part and a second step part. The dimension of the first step part in the second direction is larger than the dimension of the second step part in the second direction. The first step part is arranged on the side of the adapter facing the inside of the cell. The first cylinder part extends into the second step part. The dimension of the first step part in the first direction is d, where 0mm < d < f mm; the distance between the hole wall of the first step part and the hole wall of the second step part in the second direction is e, where 0mm < e < 3mm.

5. The cell cover plate according to claim 1, characterized in that: The part of the first cylinder part connected to the adapter is made of the same material as the adapter.

6. The cell cover plate according to claim 1, characterized in that: Along the first direction, the pole post is formed as a split structure including a first pole post part and a second pole post part, and the materials of the first pole post part and the second pole post part are different.

7. The cell cover plate according to claim 6, characterized in that: The first pole post part includes a plate part and a protrusion arranged on the side of the plate part facing the second pole post part; a groove is formed on the side of the second pole post part facing the first pole post part. The opening of the groove extends radially outward from the side wall of the second pole post part to form a flanging part. The flanging part and the plate part together form the second cylinder part, and the protrusion is embedded in the groove to together form the first cylinder part.

8. The cell cover plate according to claim 6, characterized in that: The first pole post part is formed as a plate-like structure spaced from the cover plate main body along the first direction; one end of the second pole post part facing the first pole post part forms a first boss part protruding from the circumferential side wall of the first cylinder part, and the first boss part and the first pole post part together form the second cylinder part.

9. The cell cover plate according to claim 6, characterized in that: The first pole portion includes the second column portion and a second boss portion protruding outward from one end of the second column portion facing the first column portion. The second pole portion is formed into a columnar structure. The second boss portion and the second pole portion together form the first column portion.

10. A battery cell, characterized in that: The invention comprises a cell cover plate as described in any one of claims 1 to 9.

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