Sealing nail, cover plate for battery, and secondary battery

Abstract

The application provides a sealing nail, a cover plate and a secondary battery, comprising: a nail body, a through hole extending along the axial direction of the nail body is arranged in the nail body, a protrusion is arranged on the outer side of the nail body, and the protrusion is arranged along the circumferential side of the nail body; at least one elastic sheet is arranged in the through hole, one end of the at least one elastic sheet is fixedly connected with the nail body, the other end is a free end, the free end can be pushed away by external force and automatically returns to the original position, and the through hole is opened and closed. The sealing nail provided by the application can avoid electrolyte overflow during process flow and improve production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a sealing nail, cover plate, and secondary battery for a battery. Background Technology

[0002] The existing battery production process includes primary electrolyte filling, secondary electrolyte filling, pre-pressing, and helium return. During the process of transferring the battery to the "pre-pressing" stage after primary electrolyte filling, the electrolyte filling hole is not sealed. Due to fluctuations in the production line, electrolyte can overflow from the filling hole. After the battery reaches the "pre-pressing" stage, a sealing nail is pre-pressed at the filling hole location. Traditional sealing nails are solid rubber nails, and during pre-pressing, they are not fully compressed, leaving a gap for the next process, "helium return," which involves injecting helium into the battery for a "secondary helium check." Because helium filling causes pressure changes inside the battery, electrolyte can overflow from the gap between the filling hole and the pre-pressed sealing nail when the helium line is pulled out after filling. If too much overflow occurs, it will lead to a lack of electrolyte. Furthermore, the overflowing electrolyte adheres to the casing. If the filling hole is not automatically cleaned, it will affect the tightness of subsequent aluminum nail welding, requiring further manual cleaning, which affects production line efficiency. The electrolyte overflow also leads to a lack of electrolyte inside the battery, affecting battery performance and lifespan. Utility Model Content

[0003] In order to overcome the defects in the prior art, this utility model provides a sealing nail, cover plate and secondary battery for a battery, which can prevent electrolyte leakage during process flow and improve production efficiency.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] The first aspect of this utility model discloses a sealing nail for a battery, comprising:

[0006] The nail body has a through hole extending along its axial direction, and a protrusion is provided on the outer side of the nail body, the protrusion being arranged along the circumference of the nail body;

[0007] At least one elastic piece is disposed in the through hole. One end of the at least one elastic piece is fixedly connected to the nail body, and the other end is a free end. The free end can be pushed open by external force and automatically reset, so that the through hole is opened and closed.

[0008] The above technical solution, by setting a through hole inside the nail body and setting an openable and closable elastic sheet inside the through hole, allows the elastic sheet to automatically close after liquid injection or helium filling to seal the through hole inside the nail body, thereby sealing the liquid injection hole. This prevents electrolyte overflow during process flow. At the same time, due to the setting of the elastic sheet, the sealing nail can be fully pressed into the liquid injection hole during process flow, with no gap between the sealing nail and the liquid injection hole. Compared with the existing sealing nail installation method, this can prevent electrolyte from overflowing from the gap between the sealing nail and the liquid injection hole after helium filling, thus eliminating the need to clean the electrolyte outside the shell and improving production efficiency. The protrusion set on the nail body is used for interference fit with the cover plate to stably fix the sealing nail in the liquid injection hole, preventing the sealing nail from detaching from the liquid injection hole due to excessive internal pressure of the battery after helium filling.

[0009] Furthermore, it also includes a nail head, which is located at the tail end of the nail body. The nail head has a through hole that corresponds to and communicates with a through hole inside the nail body. An elastic sheet is disposed within the through hole of the nail head. The elastic sheet on the nail head can seal the injection hole from the top of the injection hole.

[0010] Furthermore, viewed axially from the nail body, the cross-sectional area of ​​the nail head is larger than that of the nail body, and the cross-sectional area of ​​the through hole within the nail body is greater than or equal to the cross-sectional area of ​​the through hole in the nail head. When sealing the injection hole, the nail head can be positioned at the top of the injection hole to further seal the end of the injection hole.

[0011] Furthermore, at least two elastic plates are provided within the through hole. One side of each elastic plate is connected to the nail body, and the other side extends away from the end face where the nail body is connected to the elastic plate until they abut against each other. The elastic plates are at least partially connected in an abutting manner, allowing them to be pushed open under external force. This facilitates easier syringe entry during liquid injection and helium filling, and automatically closes and seals the injection hole upon withdrawal. The abutting between the elastic plates ensures the tightness of the sealing nail after closure, preventing electrolyte leakage.

[0012] Furthermore, the thickness of the elastic sheet gradually decreases along its extension direction. This makes it easier for the syringe to enter during liquid injection and helium filling.

[0013] Furthermore, the thickness of the elastic sheet is the same along its extension direction, and the angle between the extension direction of the elastic sheet and the horizontal plane is 0° to 45°. The inclined arrangement of the elastic sheet provides deformation space for the sealing nail, facilitating the insertion and removal of the syringe.

[0014] Furthermore, the protrusions are provided in multiple portions, and the multiple protrusions are arranged at intervals along the axial direction of the nail body. This further improves the firmness of the sealing nail in sealing the injection hole.

[0015] The second aspect of this utility model discloses a cover plate, comprising:

[0016] The cover plate body has a recessed hole, an injection hole and a boss inside the recessed hole, the boss being located around the injection hole, and the wall surface of the cover plate used to form the injection hole has an annular groove.

[0017] As described in any of the first aspects, when the sealing pin closes the liquid injection hole on the cover plate, the pin head abuts against the boss, the pin body is inserted into the liquid injection hole, and the protrusion on the pin body is engaged in the annular groove.

[0018] Furthermore, it also includes a sealing aluminum nail, which includes a sealing portion and an extension portion disposed on the end face of the sealing portion, the extension portion extending for a length less than or equal to the thickness of the nail head.

[0019] The third aspect of this utility model discloses a secondary battery, including a housing and an electrode assembly housed in the housing, and a cover plate as described in any of the second aspects, the cover plate covering the housing and enclosing the electrode assembly in the housing.

[0020] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0021] 1. This application provides a through hole inside the nail body and an openable and closable elastic plate inside the through hole. The elastic plate can automatically close after liquid injection or helium filling to seal the through hole inside the nail body, thereby sealing the liquid injection hole. This can prevent electrolyte overflow during process flow. At the same time, due to the setting of the elastic plate, the sealing nail can be fully pressed into the liquid injection hole during process flow, with no gap between the sealing nail and the liquid injection hole. Compared with the existing sealing nail installation method, it can prevent electrolyte from overflowing from the gap between the sealing nail and the liquid injection hole after helium filling, thus eliminating the need to clean the electrolyte outside the shell and improving production efficiency.

[0022] 2. This application provides a protrusion on the outside of the nail body, which is used to press against the cover plate to secure the sealing nail in the injection hole, preventing the sealing nail from detaching from the injection hole due to excessive internal pressure after helium filling.

[0023] To make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a structural diagram of a sealing nail provided in an embodiment of the present utility model;

[0026] Figure 2 This is a cross-sectional view of a sealing nail provided in an embodiment of this utility model;

[0027] Figure 3 This is a side view of a sealing nail provided in an embodiment of the present invention;

[0028] Figure 4 This is a connection diagram of a sealing nail provided in an embodiment of the present utility model;

[0029] Figure 5 This is a cross-sectional view of a cover plate provided in an embodiment of this utility model.

[0030] The reference numerals in the above figures are as follows: 1. Nail body; 2. Elastic sheet; 3. Nail head; 4. Through hole; 5. Protrusion; 6. Cover plate; 7. Boss; 8. Sealing aluminum nail; 9. Syringe. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. In addition, the accompanying drawings of the present invention are only simple schematic illustrations and are not depictions based on actual dimensions, as stated in advance.

[0032] In this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "forward," "backward," "between," "nearer," and "farthest" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0034] Reference Figures 1-3 This application provides a sealing pin for a battery, which is used to seal the injection hole before secondary electrolyte injection. It includes: a pin body 1 and at least one elastic piece 2. The pin body 1 has a through hole 4 extending along its axial direction. The through hole 4 is used to inject electrolyte or introduce helium gas. The outer side of the pin body 1 has a protrusion 5, which is arranged along the periphery of the pin body 1. At least one elastic piece 2 is disposed in the through hole 4, with one end fixedly connected to the pin body 1 and the other end being a free end. The free end can be pushed open by external force and automatically reset, so that the through hole 4 is open and closed.

[0035] With the above structure, the sealing nail in this embodiment of the application can be closed after the through hole 4 is filled with an elastic piece 2, thereby sealing the injection hole and preventing electrolyte from overflowing during process flow. Compared with the existing fully enclosed sealing nail, the sealing nail of this application can seal the injection hole before secondary injection and helium filling. Moreover, the setting of the elastic piece 2 makes it easier for the sealing nail to be inserted by the syringe, which can prevent the electrolyte from overflowing after the syringe punctures the surface of the sealing nail and causes an uncontrollable wound to be formed on the surface of the sealing nail.

[0036] Specifically, such as Figures 1-3 As shown, the sealing nail of this application also includes a nail head 3, which is located at the tail end of the nail body 1 and fixed to the top of the injection hole. Viewed axially from the nail body 1, the cross-sectional area of ​​the nail head 3 is larger than that of the nail body 1, thus sealing the top of the injection hole. The nail head 3 has a through hole, which corresponds to and communicates with a through hole 4 inside the nail body 1. The cross-sectional area of ​​the through hole 4 inside the nail body 1 is greater than or equal to the cross-sectional area of ​​the through hole.

[0037] In the embodiments of this application, the elastic sheet 2 is disposed in the through hole of the nail cap, thereby sealing the injection hole from the top of the injection hole and providing space for the electrolyte to rise.

[0038] It should be noted that the shape and size of the through holes of the nail body 1 and nail head 3, and the nail body 1 and nail head 3 can be flexibly set according to the actual situation, such as round, square, oval, etc., and this application does not limit them here.

[0039] In one possible embodiment, at least two elastic pieces 2 are provided in the through hole 4. One side of the at least two elastic pieces 2 is connected to the nail body 1, and the other side extends in a direction away from the end face where the nail body 1 is connected to the elastic piece 2 until they abut against each other. The abutting position between the at least two elastic pieces 2 is used for opening and closing.

[0040] In the embodiments of this application, the sealing nail is provided with four elastic pieces 2, which are arranged in a circle. The contact ends of the four elastic pieces 2 form a cross structure. When the electrolyte is injected, the syringe 9 enters the injection hole from the cross structure. After the electrolyte is injected, the syringe 9 leaves the sealing nail, and the cross structure closes automatically.

[0041] To facilitate the insertion and removal of the syringe 9, the thickness of the elastic sheet 2 gradually decreases along its extension direction, making it easier for the syringe 9 to enter and providing deformation space for the elastic sheet 2. When the sealing pin is installed on the battery cover 6, the elastic sheet 2 extends from the cover 6 toward the inside of the battery.

[0042] In one possible embodiment, the thickness of the elastic sheet 2 is the same along its extension direction, and the angle between the extension direction of the elastic sheet 2 and the horizontal plane is 0° to 45°.

[0043] In the embodiments of this application, the protrusion 5 is formed by extending from the wall surface of the nail body 1 in a direction away from the nail body 1, and is disposed around the periphery of the nail body 1. The protrusion 5 is used to firmly engage the sealing nail at the injection hole, thereby sealing the injection hole. The shape, size, and number of the protrusion 5 can be flexibly set according to the actual situation.

[0044] In the embodiments of this application, in order to further improve the sealing strength of the sealing nail, two protrusions 5 are provided on the nail body 1, and the two protrusions 5 are arranged at intervals along the axial direction of the nail body 1.

[0045] To ensure the sealing pin automatically closes after liquid injection and helium filling, it needs to be made of a corrosion-resistant and highly elastic material. In the embodiments of this application, the sealing pin is made of rubber. In one possible embodiment, the sealing pin is integrally molded.

[0046] This application embodiment also provides a cover plate 6, as shown in the following example. Figure 4 As shown, the cover plate 6 includes a cover plate body and a sealing pin for the battery as described in the above embodiment. The cover plate body has a recessed hole, and the recessed hole has an injection hole and a boss 7. The boss 7 is located around the injection hole. The wall surface of the cover plate 6 used to form the injection hole has an annular groove. When the sealing pin closes the injection hole on the cover plate 6, the pin head 3 abuts against the boss 7, the pin body 1 is inserted into the injection hole, and the protrusion 5 on the pin body 1 is stuck in the annular groove.

[0047] Specifically, before the secondary injection, the sealing pin is pressed into the injection hole so that the protrusion 5 of the sealing pin can be locked in the annular groove and the pin head 3 abuts against the boss 7. During the secondary injection, a syringe 9 that is compatible with the contact end of the elastic sheet 2 can be used. The syringe 9 is pushed into the sealing pin by squeezing the cross structure to inject liquid. After the injection is completed, the syringe 9 is pulled out and the cross structure automatically closes to seal the injection hole and prevent electrolyte from overflowing during the process flow.

[0048] During the helium return process, a suitable syringe is used to squeeze the cross structure into the battery to fill it with helium. After filling, the syringe is withdrawn, and the recessed part of the sealing pin closes to prevent the battery from overflowing due to excessive internal pressure.

[0049] Optionally, the syringe is made of a corrosion-resistant material, such as stainless steel.

[0050] After helium filling is complete, the sealing pins and the recessed holes on the cover plate 6 need to be further sealed to ensure the battery's airtightness. Figure 5 As shown, the cover plate 6 is also provided with a sealing aluminum nail 8. The sealing aluminum nail 8 includes a sealing part and an extension part provided on the end face of the sealing part. When the sealing aluminum nail 8 seals the concave hole, the side of the sealing part away from the injection hole is at the same horizontal plane as the end face of the cover plate 6. The side of the sealing part near the injection hole forms the extension part, and the extension part extends toward the boss 7.

[0051] The shape and size of the sealing aluminum nail 8 are flexibly set according to the shape and size of the recess on the cover plate 6. The length of the extension is flexibly set according to the actual situation, and can be the same as or less than the thickness of the nail head 3. When the thickness of the extension is the same as that of the nail head 3, the end of the extension away from the sealing part is connected to the end face of the boss 7.

[0052] Optionally, the sealing aluminum nail 8 and the cover plate 6 are connected by welding to improve the strength of the seal.

[0053] This application also provides a battery including a housing and an electrode assembly housed in the housing, as well as a cover plate 6 as described in the above embodiments, the cover plate 6 covering the housing and enclosing the electrode assembly in the housing.

[0054] This utility model uses specific embodiments to illustrate the principle and implementation of the utility model. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the utility model. Therefore, the content of this specification should not be construed as a limitation of the utility model.

Claims

1. A sealing pin for a battery, characterized in that, include: The nail body has a through hole extending along its axial direction, and a protrusion is provided on the outer side of the nail body, the protrusion being arranged along the circumference of the nail body; At least one elastic piece is disposed in the through hole. One end of the at least one elastic piece is fixedly connected to the nail body, and the other end is a free end. The free end can be pushed open by external force and automatically reset, so that the through hole is opened and closed.

2. The sealing pin for a battery according to claim 1, characterized in that, It also includes a nail head, which is located at the tail end of the nail body. The nail head has a nail head through hole, which is connected to a through hole in the nail body. The elastic sheet is located in the nail head through hole.

3. The sealing pin for a battery according to claim 2, characterized in that, Viewed from the axial direction of the nail body, the cross-sectional area of ​​the nail head is greater than that of the nail body, and the cross-sectional area of ​​the through hole in the nail body is greater than or equal to that of the through hole in the nail head.

4. The sealing pin for a battery according to claim 1, characterized in that, The through hole is provided with at least two elastic pieces. One side of the at least two elastic pieces is connected to the nail body, and the other side extends in a direction away from the end face where the nail body is connected to the elastic piece until they abut against each other.

5. A sealing pin for a battery according to claim 4, characterized in that, The thickness of the elastic sheet gradually decreases along its extension direction.

6. A sealing pin for a battery according to claim 4, characterized in that, The thickness of the elastic sheet is the same along its extension direction, and the angle between the extension direction of the elastic sheet and the horizontal plane is 0° to 45°.

7. The sealing pin for a battery according to claim 1, characterized in that, The protrusions are provided in multiple portions, and the multiple protrusions are arranged at intervals along the axial direction of the nail body.

8. A cover plate, characterized in that, include: The cover plate body has a recessed hole, an injection hole and a boss inside the recessed hole, the boss being located around the injection hole, and the wall surface of the cover plate used to form the injection hole has an annular groove. The sealing pin of the battery as described in any one of claims 1 to 7, when the sealing pin closes the liquid injection hole on the cover plate, the pin head abuts against the boss, the pin body is inserted into the liquid injection hole, and the protrusion on the pin body is stuck in the annular groove.

9. A cover plate according to claim 8, characterized in that, It also includes a sealing aluminum nail, which includes a sealing part and an extension provided on the end face of the sealing part, the extension extending for a length less than or equal to the thickness of the nail head.

10. A secondary battery, characterized in that, It includes a housing and an electrode assembly housed within the housing, and a cover plate as claimed in any one of claims 8 to 9, the cover plate covering the housing and enclosing the electrode assembly within the housing.

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