Sealing nail cover plate and sealing structure

Abstract

The utility model discloses a sealing nail cover plate which is used for sealing a sealing nail and a top cover of a battery, the sealing nail cover plate comprises a cover plate main body which comprises a first main plane and a second main plane which are opposite to each other, and the second main plane abuts against the sealing nail; and a heat insulation layer is arranged on the first main plane. According to the sealing nail cover plate, the heat insulation layer is arranged on the cover plate body of the sealing nail cover plate, so that the speed of heat loss at the welding position is reduced, the problem of welding seam cracking caused by sudden temperature drop at the welding position can be effectively solved, the reject ratio of batteries is greatly reduced, and the sealing performance of welding is improved. The utility model further discloses a sealing structure which comprises a top cover, a sealing nail and the sealing nail cover plate recorded in the embodiment, a liquid injection hole is formed in the top cover, the sealing nail is packaged in the liquid injection hole, and the sealing nail cover plate is welded to the top cover.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a sealing nail cover plate and a sealing structure. Background Art

[0002] Lithium batteries are usually provided with a cover plate with a liquid injection hole for injecting electrolyte into the battery cell. After the electrolyte injection is completed, the liquid injection hole needs to be sealed by a sealing structure so that the inside of the battery cell is completely isolated from the external environment.

[0003] The existing sealing structure includes a sealing pin and a sealing pin cover plate, wherein the sealing pin cover plate is mostly made of aluminum or stainless steel. Due to its excellent thermal conductivity, the sealing pin cover plate is directly in contact with the air on all sides during welding, causing heat dissipation at the welding point too quickly. Problems such as weld cracking, insufficient welding strength, and poor welding morphology are prone to occur at the welding position, seriously affecting the sealing of the battery. Utility Model Content

[0004] The main purpose of the utility model is to provide a sealing nail cover plate and a sealing structure, aiming to solve the problem that the welding seam of the sealing nail cover plate is prone to cracking.

[0005] In order to achieve the above-mentioned purpose, the utility model provides a sealing nail cover plate, which is used to seal the sealing nail with the top cover of the battery, and the sealing nail cover plate includes:

[0006] The cover plate body comprises a first main plane and a second main plane which are opposite to each other, wherein the second main plane is in contact with the sealing nail; and a heat insulating layer is arranged on the first main plane.

[0007] In some embodiments, the cover plate body is recessed from the first main plane toward the second main plane to form an annular groove, and the heat insulation layer is disposed on a surface of the annular groove.

[0008] In some embodiments, the thermal insulation layer is made of ceramic and is coated on the surface of the annular groove.

[0009] In some embodiments, the annular groove is arranged in an inverted trapezoidal shape that is wider at the top and narrower at the bottom.

[0010] In some embodiments, the inner diameter of the annular groove is greater than half of the radius of the cover plate body.

[0011] In some embodiments, the side surface of the cover body is an inclined surface.

[0012] In some embodiments, the annular groove is formed by stamping from the first main plane toward the second main plane.

[0013] The utility model further proposes a sealing structure of a battery, comprising a top cover, a sealing nail and the sealing nail cover plate described in the aforementioned embodiment, wherein the top cover is provided with a liquid injection hole, the sealing nail is packaged in the liquid injection hole, and the sealing nail cover plate is welded to the top cover.

[0014] In some embodiments, an annular protrusion is provided at one end of the sealing pin, and the diameter of the annular protrusion is larger than the diameter of the injection hole.

[0015] In some embodiments, the injection hole is configured with a sink, and the sink is used to accommodate the annular protrusion.

[0016] The utility model provides a heat insulation layer on the cover plate body of the sealing nail cover plate to block the heat exchange between the sealing nail cover plate and the air, so as to slow down the speed of heat loss at the welding point, and can effectively solve the problem of weld cracking caused by a sudden drop in temperature at the welding point, greatly reduce the defective rate of the battery, and improve the sealing of the welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of an embodiment of a sealing nail cover plate of the utility model;

[0018] Figure 2 for Figure 1 A cross-sectional view of the middle sealing nail cover plate;

[0019] Figure 3 for Figure 1 A cross-sectional view of the middle cover body;

[0020] Figure 4 It is a structural schematic diagram of an embodiment of the sealing structure of the utility model.

[0021] Reference numerals:

[0022] 100, sealing nail cover plate; 110, cover plate body; 111, first main plane; 112, second main plane; 120, thermal insulation layer; 130, annular groove; 200, sealing nail; 210, annular protrusion; 300, top cover; 310, injection hole; 311, sinker. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the scheme in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0025] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0026] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0027] The utility model provides a sealing nail cover plate 100, which is used to seal the sealing nail 200 with the top cover of the battery. Figure 1-Figure 3 , the sealing nail cover plate 100 comprises:

[0028] The cover plate body 110 includes a first main plane 111 and a second main plane 112 opposite to each other. The second main plane 112 is in contact with the sealing nail. A heat insulation layer 120 is disposed on the first main plane 111 .

[0029] In the closure of the battery, the sealing nail cover plate 100 plays a key sealing role. A suitable sealing nail cover plate 100 can greatly improve the safety and stability of the battery. The sealing nail cover plate 100 of the battery is usually made of metal, such as aluminum or stainless steel. Its functions include: preventing leakage of internal substances of the battery; preventing external environmental substances from entering the battery to maintain the stability of the internal environment of the battery; and providing mechanical support and fixation. Therefore, the structural design of the sealing nail cover plate 100 is very important.

[0030] In this embodiment, the sealing nail cover 100 includes a cover body 110 and a heat insulating layer 120 disposed on the cover body 110. The shape design of the cover body 110 is affected by many factors, including the battery type, purpose, and the structural shape of the battery body. For example, a circular sealing nail cover 100 is suitable for large cylindrical batteries. This shape of sealing nail cover 100 usually surrounds the top or bottom of the battery and is combined with the battery casing; a rectangular sealing nail cover 100 is suitable for some square or rectangular batteries and is suitable for thinner battery types; and in order to improve the sealing performance, the edge of the sealing nail cover 100 can also be wavy or serrated to increase the sealing area and improve the sealing effect. The shape of the cover body 110 of the present application is not limited.

[0031] The cover plate body 110 is usually welded to the metal shell of the battery. Since a large amount of heat is generated during the welding process, and the metal cover plate body 110 has excellent thermal conductivity, the heat is lost quickly, causing a rapid temperature rise and fall process at the welding point, which can easily lead to weld cracking and insufficient welding strength, thereby affecting the sealing of the battery. Therefore, in this embodiment, a heat insulation layer 120 is provided on the cover plate body 110 to slow down the heat loss rate and prevent weld cracking.

[0032] The heat insulation layer 120 can be only arranged in a partial area of ​​the first main plane 111 of the cover body 110, or it can cover the entire first main plane 111 to isolate the cover body 110 from the air and prevent heat from flowing into the air. The specific setting method can be adjusted according to the actual demand for thermal insulation performance. It can be understood that there are many ways to connect the heat insulation layer 120 to the cover body 110. It can be coated on the cover body 110 or bonded to the cover body 110. The heat insulation layer 120 includes a composite layer composed of one or more of a ceramic layer, a glass fiber layer, a rock wool layer, and a polystyrene board layer.

[0033] This embodiment provides a heat insulating layer 120 on the cover body of the sealing nail cover 100, which can slow down the rate of heat loss at the welding point, effectively solve the problem of weld cracking caused by a sudden drop in temperature at the welding point, greatly reduce the defective rate of the battery, and improve the sealing of the welding.

[0034] like Figure 1 As shown, in some embodiments, the cover plate body 110 is recessed from the first main plane 111 to the second main plane 112 to form an annular groove 130 , and the heat insulation layer 120 is disposed on the surface of the annular groove 130 .

[0035] When welding the cover plate body 110, due to the high temperature and deformation at the welding point, stress concentration will inevitably occur, which will reduce the strength of the welding point. In this embodiment, an annular groove 130 is set on the cover plate body 110, so that the stress generated during welding can be released more evenly at the annular groove 130, thereby improving the strength of the welding point and extending the battery life. The heat insulation layer 120 is set in the annular groove 130, which can increase the coverage area of ​​the heat insulation layer 120 and improve the effect of delaying heat loss. It can be understood that the shape of the annular groove 130 is related to the shape of the cover plate body 110. If the cover plate body 110 is circular, the annular groove 130 is also circular. If the cover plate body 110 is square, the annular groove 130 is also square. The same applies to other shapes, which will not be repeated here.

[0036] like Figure 2 As shown, in some embodiments, the material of the heat insulating layer 120 is ceramic, which is coated on the surface of the annular groove 130. In addition to low thermal conductivity, the ceramic material also has excellent high temperature stability, and can maintain its structure and performance under extreme temperature conditions. The ceramic material also has electrical insulation, chemical stability and oxidation resistance, and is very suitable for being set inside the battery as the heat insulating layer 120 of the cover plate body 110.

[0037] like Figure 1-Figure 4 As shown, in some embodiments, the annular groove 130 is arranged in an inverted trapezoidal shape that is wider at the top and narrower at the bottom.

[0038] It can not only ensure that the cover plate body 110 has sufficient strength and is not prone to cracking, but also reduce the difficulty of processing the cover plate body 110. Preferably, the depth of the annular groove 130 is half the thickness of the cover plate body 110, so that the annular groove 130 can improve the stress generated during welding while reducing the impact on the structural strength of the cover plate body 110 itself. Furthermore, the inner corners of the annular groove 130 can be set as rounded corners to enhance the durability of the structure and reduce stress concentration; and in the manufacturing process, especially in terms of cutting and forming, sharp corners may increase the difficulty of manufacturing, while rounded corners are relatively easier to process, which helps to simplify the production process.

[0039] like Figure 1 and Figure 2 As shown, in some embodiments, the inner diameter of the annular groove 130 is greater than half of the radius of the cover plate body 110 .

[0040] Specifically, if the inner diameter of the annular groove 130 is one third of the radius of the cover body 110, it means that the annular groove 130 is set in the middle of the cover body 110, and its position is far away from the welding point, and it cannot well reflect the effect of eliminating the stress of the welding point. Therefore, the inner diameter of the annular groove 130 is greater than one half of the radius of the cover body 110. For example, the inner diameter of the annular groove 130 is set to three quarters of the radius of the cover body 110. At this time, the annular groove 130 is close to the welding point, and the stress generated during welding can be evenly released through the annular groove 130, avoiding the problem of weld cracking.

[0041] like Figure 2 and Figure 3 As shown, in some embodiments, the side surface of the cover body 110 is an inclined surface.

[0042] Compared with a vertical or horizontal mating surface, setting the side of the cover body 110 as an inclined surface can guide the cover body 110 to automatically enter the correct position, simplify the assembly process, and reduce the possibility of jamming or wrong mating. At the same time, the contact area between the inclined surfaces is larger, and the connection after welding is also tighter. Therefore, setting the side of the cover body 110 as an inclined surface helps to improve assembly efficiency, reduce friction, and reduce manufacturing costs.

[0043] In some embodiments, the annular groove 130 is formed by stamping from the first main plane 111 to the second main plane 112. The required shape can be obtained by preparing a corresponding mold and then using the die to stamp the metal. Stamping has high processing accuracy and efficiency, high production stability, and easy quality control, which is more suitable for the production of sealing nail cover plates.

[0044] like Figure 4 As shown, the utility model further proposes a sealing structure, including a top cover 300, a sealing pin 200 and the sealing pin cover plate 100 recorded in the aforementioned embodiment, a liquid injection hole 310 is provided on the top cover 300, the sealing pin 200 is encapsulated in the liquid injection hole 310, and the sealing pin cover plate 100 is welded to the top cover 300.

[0045] The specific structure of the sealing nail cover plate 100 refers to the above embodiment. Since the sealing structure in this embodiment adopts all the technical solutions of all the above embodiments, it at least has all the technical effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0046] It can be understood that the top of the sealing pin 200 should be configured to cooperate with the bottom of the sealing pin cover plate 100, so that after welding, the top of the sealing pin 200 can fit the bottom of the sealing pin cover plate 100 to enhance the sealing performance.

[0047] like Figure 4As shown, in some embodiments, an annular protrusion 210 is provided at one end of the sealing pin 200 , and the diameter of the annular protrusion 210 is greater than the diameter of the injection hole 310 .

[0048] By providing an annular protrusion 210 with a larger diameter at one end of the sealing pin 200, one end of the sealing pin 200 extends into the injection hole 310 to complete the sealing of the injection hole 310, and the annular protrusion 210 at the other end abuts against the top of the injection hole 310 to enhance its sealing performance. Preferably, an adhesive can be provided on the side of the annular protrusion 210 connected to the injection hole 310 to improve the tightness of the connection between the sealing pin 200 and the injection hole 310. Preferably, the sealing pin 200 is integrally formed, with higher strength and better sealing performance.

[0049] like Figure 4 As shown, in some embodiments, the injection hole 310 is configured with a sink 311 , and the sink 311 is used to accommodate the annular protrusion 210 .

[0050] During welding, the sealing nail 200 is inserted into the injection hole 310, the annular protrusion 210 abuts against the sink 311, and then the sealing nail cover plate 100 is covered on the top of the sealing nail 200, and then the side of the sealing nail cover plate 100 and the side of the sink 311 are welded together to complete the sealing of the injection hole 310. By setting the sink 311, the sealing nail 200 and the injection hole 310 are directly matched more closely, the assembly between the sealing nail cover plate 100 and the top cover 300 is more convenient, and the welding point is not easily affected by the outside world, which further improves the sealing performance of the injection hole 310.

[0051] The above description is only a partial or preferred embodiment of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A sealing nail cover plate, used to seal the sealing nail with the top cover of the battery, characterized in that: The sealing nail cover plate comprises: The cover plate body comprises a first main plane and a second main plane which are opposite to each other, wherein the second main plane is in contact with the sealing nail; and a heat insulating layer is arranged on the first main plane.

2. The sealing nail cover plate according to claim 1, characterized in that: The cover plate body is recessed from the first main plane toward the second main plane to form an annular groove, and the heat insulation layer is arranged on the surface of the annular groove.

3. The sealing nail cover plate according to claim 2, characterized in that: The material of the heat insulation layer is ceramic, and is coated on the surface of the annular groove.

4. The sealing nail cover plate according to claim 3, characterized in that: The annular groove is arranged in an inverted trapezoidal shape which is wider at the top and narrower at the bottom.

5. The sealing nail cover plate according to claim 4, characterized in that: The inner diameter of the annular groove is greater than half of the radius of the cover plate body.

6. The sealing nail cover plate according to any one of claims 1 to 5, characterized in that: The side surface of the cover plate body is an inclined surface.

7. The sealing nail cover plate according to claim 5, characterized in that: The annular groove is formed by stamping from the first main plane toward the second main plane.

8. A sealing structure of a battery, characterized in that: It comprises a top cover, a sealing pin and a sealing pin cover plate according to any one of claims 1 to 7, wherein the top cover is provided with a liquid injection hole, the sealing pin is packaged in the liquid injection hole, and the sealing pin cover plate is welded to the top cover.

9. The sealing structure according to claim 8, characterized in that: An annular protrusion is arranged at one end of the sealing pin, and the diameter of the annular protrusion is larger than the diameter of the injection hole.

10. The sealing structure according to claim 9, characterized in that: The injection hole is configured with a sink, and the sink is used to accommodate the annular protrusion.

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