Cover plate and metal shell lithium battery

Abstract

The utility model provides a cover plate and a metal shell lithium battery, and the cover plate comprises a cover plate body and a sealing nail, a liquid injection opening is formed in the cover plate; the liquid injection port extends upwards to form a limiting step; the side wall of the sealing nail is attached to the side wall of the limiting step. The sealing nail is welded on the limiting step and is suitable for blocking the liquid injection opening; a molten pool formed after the sealing nails and the cover plate body are welded penetrates through the cover plate body and the bottom face of the limiting step. The welded molten pool penetrates through the cover plate body and the bottom face of the limiting step, the welding area between the sealing nail and the cover plate body is increased, the effective width of the molten pool is increased, multiple sealing is achieved, and the risk that a through crack is formed after the crack is caused by stress when the molten pool is cooled is reduced.

Description

Technical Field

[0001] The utility model relates to the field of lithium batteries, and particularly to a cover plate and a lithium battery with a metal shell. Background Art

[0002] The general processes of a lithium battery with a metal shell are as follows: electrode sheet production, winding, shell assembly, baking, liquid injection, formation, sealing nail welding, testing, etc. Sealing nail welding is a key process of a lithium battery with a metal shell. The sealing nail welding completes the final sealing of the battery cell, and the reliability of the welding has a direct impact on the performance and safety of the product.

[0003] In the related art, the sealing nail is welded to the side wall of the liquid injection port of the cover plate through laser welding. Cracks generated by the stress in the molten pool formed by laser welding are a common problem. The generation of cracks reduces the actual effective depth of the welding molten pool. In severe cases, through cracks occur, which will directly lead to the sealing failure at the welding position and affect the performance and safety of the product.

[0004] How to avoid cracks in the molten pool after sealing nail welding is an urgent problem to be solved at present. Content of the Utility Model

[0005] The purpose of the utility model is to provide a cover plate and a lithium battery with a metal shell.

[0006] In order to solve the above technical problems, the utility model provides a cover plate, including:

[0007] A cover plate body and a sealing nail;

[0008] The cover plate is provided with a liquid injection port;

[0009] The liquid injection port extends upward to form a limiting step;

[0010] The side wall of the sealing nail fits with the side wall of the limiting step;

[0011] The sealing nail is welded and arranged on the limiting step and is suitable for plugging the liquid injection port; wherein, the molten pool formed after the sealing nail is welded to the cover plate body penetrates through the bottom surface of the cover plate body and the limiting step.

[0012] Further, the sealing nail includes a welding part and a plugging part;

[0013] The plugging part faces the liquid injection port;

[0014] The welding part is arranged on the limiting step.

[0015] Further, the side wall of the sealing nail fits with the side wall of the limiting step, and the bottom of the sealing nail fits with the bottom surface of the limiting step.

[0016] Further, a plugging column extends downward from the plugging portion of the sealing nail;

[0017] The plugging column is inserted into the liquid injection port.

[0018] Further, the bottom of the sealing nail is conical, and the tip of the bottom of the sealing nail is inserted into the liquid injection port.

[0019] Further, the bottom of the sealing nail is flat.

[0020] Further, the thickness range of the welding portion is 0.3-0.8 mm.

[0021] Further, the number of the molten pools is N, where N is greater than or equal to 1 and less than or equal to 5.

[0022] Further, the molten pool completely covers the bottom surface of the limiting step and the part of the sealing nail opposite to the limiting step.

[0023] The utility model also provides a lithium battery with a metal shell, including:

[0024] A battery body and the cover plate as described above;

[0025] The cover plate covers the top of the battery body

[0026] The beneficial effect of the utility model is that the utility model provides a cover plate and a lithium battery with a metal shell. Among them, the cover plate includes: a cover plate body and a sealing nail; the cover plate is provided with a liquid injection port; the liquid injection port extends upward to form a limiting step; the side wall of the sealing nail fits with the side wall of the limiting step; the sealing nail is welded on the limiting step and is suitable for plugging the liquid injection port; wherein, the molten pool formed after the sealing nail is welded with the cover plate body penetrates through the cover plate body and the bottom surface of the limiting step. By making the molten pool after welding penetrate through the cover plate body and the bottom surface of the limiting step, the welding area between the sealing nail and the cover plate body is increased, the width of the effective molten pool is increased, multiple seals are achieved, and the risk of forming through cracks after cracks are caused by stress during the cooling of the molten pool is reduced. Description of the Drawings

[0027] The following further describes the utility model with reference to the drawings and embodiments.

[0028] Figure 1 is a cross-sectional view of the cover plate provided by the embodiment of the utility model.

[0029] Figure 2 is a structural schematic diagram of the cover plate provided by the embodiment of the utility model.

[0030] Figure 3 Yes Figure 1 It is an enlarged view of part A in the figure.

[0031] Figure 4 It is a cross-sectional view of the molten pool formed after welding the sealing nail and the cover plate body provided by the embodiment of the present invention.

[0032] Figure 5 It is a cross-sectional view of a partial structure of another sealing nail and cover plate provided by the embodiment of the present invention.

[0033] Figure 6 It is a cross-sectional view of a partial structure of the third sealing nail and cover plate provided by the embodiment of the present invention

[0034] In the figure: 100, cover plate body; 110, liquid injection port; 120, limiting step; 121, bottom surface; 122, side wall; 200, sealing nail; 210, welding part; 220, blocking part; 221, blocking column; 300, molten pool. Detailed implementation manners

[0035] Now, the present invention will be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0036] In the embodiment, please refer to Figures 1 - 6 , at least one embodiment provides a cover plate, including: a cover plate body 100 and a sealing nail 200; the cover plate is provided with a liquid injection port 110; the liquid injection port 110 extends upward to form a limiting step 120; the side wall 122 of the sealing nail 200 is attached to the side wall 122 of the limiting step 120; the sealing nail 200 is welded on the limiting step 120 and is adapted to block the liquid injection port 110; wherein, the molten pool 300 formed after welding the sealing nail 200 and the cover plate body 100 penetrates through the bottom surface 121 of the cover plate body 100 and the limiting step 120. By making the molten pool 300 after welding penetrate through the bottom surface 121 of the cover plate body 100 and the limiting step 120, the welding area between the sealing nail 200 and the cover plate body 100 is increased, the width of the effective molten pool 300 is increased, multiple seals are achieved, and the risk of forming through cracks due to stress caused by the cooling of the molten pool 300 is reduced.

[0037] It should be noted that the width range of the effective molten pool 300 is between 0.3 - 2 mm.

[0038] Please refer to Figure 3, wherein, the sealing nail 200 includes a welding part 210 and a plugging part 220; the plugging part 220 faces the liquid injection port 110; the welding part 210 is arranged on the limiting step 120. The side wall 122 of the sealing nail 200 fits with the side wall 122 of the limiting step 120, and the bottom of the sealing nail 200 fits with the bottom surface 121 of the limiting step 120. The bottom surface 121 of the welding part 210 is arranged on the limiting step 120. After melting the welding part 210 and the bottom surface 121 of the limiting step 120 by laser welding, a molten pool 300 is formed, increasing the sealing area and forming multiple seals.

[0039] Wherein, the thickness range of the welding part 210 is 0.3 - 0.8 mm. The effective width of the welding part 210 is greater than 2 mm.

[0040] In some embodiments, the plugging part 220 of the sealing nail 200 extends downward to form a plugging column 221; the plugging column 221 is inserted into the liquid injection port 110.

[0041] Please refer to Figure 5 , in other embodiments, the bottom of the sealing nail 200 is conical, and the tip of the bottom of the sealing nail 200 is inserted into the liquid injection port 110. Or, please refer to Figure 6 , the bottom of the sealing nail 200 is flat.

[0042] Please refer to Figure 4 , in order to ensure the width of the effective molten pool 300, in some embodiments, the number of the molten pools 300 is N, where N is greater than or equal to 1 and less than or equal to 5.

[0043] In some embodiments, the molten pool 300 completely covers the bottom surface 121 of the limiting step 120 and the part of the sealing nail 200 opposite to the limiting step 120. Thus, the width of the effective molten pool 300 between the sealing nail 200 and the cover plate is ensured, and multiple seals are achieved.

[0044] At least one embodiment further provides a metal - shell lithium battery, including: a battery body and the cover plate as described above; the cover plate covers the top of the battery body. By making the molten pool 300 after welding penetrate through the cover plate body 100 and the bottom surface 121 of the limiting step 120, the welding area between the sealing nail 200 and the cover plate body 100 is increased, the width of the effective molten pool 300 is improved, multiple seals are achieved, and the risk of forming through - cracks due to stress caused by the cooling of the molten pool 300 is reduced.

[0045] In summary, the present utility model provides a cover plate and a lithium battery with a metal casing. Among them, the cover plate includes: a cover plate body 100 and a sealing nail 200; a liquid injection port 110 is provided on the cover plate; the liquid injection port 110 extends upward to form a limiting step 120; the side wall 122 of the sealing nail 200 fits with the side wall 122 of the limiting step 120; the sealing nail 200 is welded on the limiting step 120 and is adapted to block the liquid injection port 110; wherein, the molten pool 300 formed after welding the sealing nail 200 and the cover plate body 100 penetrates through the bottom surface 121 of the cover plate body 100 and the limiting step 120. By making the molten pool 300 after welding penetrate through the bottom surface 121 of the cover plate body 100 and the limiting step 120, the welding area between the sealing nail 200 and the cover plate body 100 is increased, the width of the effective molten pool 300 is increased, multiple seals are achieved, and the risk of forming through cracks after cracks are caused by stress during the cooling of the molten pool 300 is reduced.

[0046] All the components (components without specific structures described) selected in this application are common standard components or components known to those skilled in the art. Their structures and principles can all be learned by those skilled in the art through technical manuals or obtained through conventional experimental methods. Moreover, the software programs involved in this application are all prior arts, and this application does not involve any improvement to the software programs.

[0047] In the description of the embodiments of the present utility model, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0048] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] Based on the above-mentioned ideal embodiments of the present utility model as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A cover plate, characterized in that: include: Cover plate body and sealing nails; The cover plate is provided with a liquid injection port; The liquid injection port extends upward to form a limiting step; The side wall of the sealing pin is in contact with the side wall of the limiting step; The sealing pin is welded on the limiting step and is suitable for sealing the liquid injection port; wherein the molten pool formed by welding the sealing pin and the cover plate body penetrates the cover plate body and the bottom surface of the limiting step; The molten pool completely covers the bottom surface of the limiting step and the portion of the sealing pin opposite to the limiting step; The sealing nail comprises a welding portion and a sealing portion; The blocking portion is opposite to the liquid injection port; The welding portion is arranged on the limiting step; The side wall of the sealing pin is in contact with the side wall of the limiting step, and the bottom of the sealing pin is in contact with the bottom surface of the limiting step.

2. The cover plate according to claim 1, characterized in that: The sealing portion of the sealing nail extends downward to form a sealing column; The blocking column is inserted into the injection port.

3. The cover plate according to claim 1, characterized in that: The bottom of the sealing pin is conical, and the tip of the bottom of the sealing pin is inserted into the liquid injection port.

4. The cover plate according to claim 1, characterized in that: The bottom of the sealing nail is a plane.

5. The cover plate according to claim 1, characterized in that: The thickness of the welding portion is in the range of 0.3-0.8 mm.

6. The cover plate according to claim 1, characterized in that: The number of the molten pools is N, where N is greater than or equal to 1 and less than or equal to 5.

7. A metal shell lithium battery, characterized in that: include: A battery body and a cover plate as claimed in any one of claims 1 to 6; The cover plate covers the top of the battery body.

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