WO2024148693A1 - End cap assembly, battery cell and electric device - Google Patents

Abstract

Disclosed in the present application are an end cap assembly, a battery cell and an electric device. The end cap assembly is used for the battery cell, and comprises an end cap and a sealing member, wherein a filling port is provided in the end cap, and the sealing member fits with the filling port in a sealing manner; the edge of the sealing member is fixed to the end cap by means of a first welding layer formed by means of welding along a first track, and the first welding layer comprises a plurality of welding spots distributed along the first track; the edge of the sealing member is further fixed to the end cap by means of a second welding layer formed by means of welding along a second track; the second welding layer comprises a plurality of welding spots distributed along the second track; and at least some of the welding spots of the second welding layer are connected to the welding spots of the first welding layer, such that the first welding layer and the second welding layer form a continuous welding seam.

Description

End cap assembly, battery cell and electrical equipment

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Chinese patent application 202320043896.6, entitled “End cover assembly, battery cell and electrical equipment”, filed on January 9, 2023, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to the field of battery cells, and in particular to an end cover assembly, a battery cell and an electrical device.

Background technique

The battery cell has a shell and an end cap, and an injection hole for injecting electrolyte is opened on the end cap. In order to seal the injection hole, a sealant is welded and fixed on the end cap in the existing end cap, and the gap at the joint between the sealant and the end cap is sealed by the weld point formed by welding.

During the welding process, there is a large amount of heat in the welding pool. Due to the influence of welding heat, the welding yield of the welded seal cannot meet the requirements.

Summary of the invention

The main purpose of the present application is to propose an end cover assembly, aiming to solve the problem of air holes existing in the welding process of the seal of the existing end cover assembly.

To achieve the above-mentioned purpose, the end cap assembly proposed in the present application is used for a battery cell, the end cap assembly comprising an end cap and a sealing member, a liquid injection hole is provided on the end cap, and the sealing member is in sealing cooperation with the liquid injection hole;

The edge of the sealing member is fixed to the end cover through a first welding layer formed by welding along a first track, wherein the first welding layer includes a plurality of welding points distributed along the first track;

The edge of the sealing member is also fixed to the end cover by a second welding layer formed by welding along a second track; the second welding layer includes a plurality of welding points distributed along the second track;

At least part of the welding spots of the second welding layer are connected to the welding spots of the first welding layer, so that the first welding layer and the second welding layer form a continuous weld.

The welding points of the first welding layer and the welding points of the second welding layer are used to weld and seal the joint between the edge of the seal and the end cover. By using the first welding layer and the second welding layer to form a continuous weld, the joint between the edge of the seal and the end cover is completely sealed by the weld, thereby ensuring the sealing performance of the joint between the seal and the end cover. Since the second welding layer can cover the pores formed by the first welding layer during the formation of the weld, the second welding layer welds and seals the pores formed during the welding of the first welding layer, thereby avoiding the problem of reduced sealing performance due to the presence of pores. Helps improve the welding yield of seals.

In some examples, the welding points of the first welding layer and the welding points of the second welding layer are staggered with each other.

By staggering the welding spots of the first welding layer and the adjacent welding spots of the second welding layer, it can be ensured that there is no gap between the adjacent welding spots of the first welding layer, avoiding the problem of welding leaks, so that the first welding layer and the second welding layer can form a continuous weld.

In some examples, the number of the second welding layers is multiple layers, and the first welding layer and the multiple layers of the second welding layers form a continuous weld.

By providing multiple layers of the second welding layer, the overlap rate between the second welding layer and the first welding layer can be increased, thereby improving the welding sealing performance and preventing the occurrence of pores or leaking welds. By providing multiple layers of the second welding layer, the welding rhythm can be conveniently controlled, so that when the second welding layer seals the pores formed by the first welding layer, the gas in the cavity formed between the seal and the end cover has sufficient time to escape, thereby helping to improve the safety performance of the end cover assembly.

In some examples, the welding points of the second welding layer adjacent to the first welding layer are at least partially offset from the welding points of the first welding layer.

The second welding layer adjacent to the first welding layer does not completely overlap with the first welding layer, so that the second welding layer can cover the pores formed by the first welding layer. At the same time, the partial staggered setting helps to improve the welding efficiency and increase the overlap rate between the first welding layer and the second welding layer.

In some examples, adjacent welding points of the second welding layer are at least partially staggered.

By cooperating with the adjacent second welding layers, the second welding layers can completely cover the possible weld leaks or pores on the first welding layer, thereby improving the welding efficiency.

In some examples, the first welding layer has an end welding spot arranged along the first track, the second welding layer has a head welding spot arranged along the second track, and the head welding spot of the second welding layer is at least partially connected to the end welding spot of the first welding layer.

The first end weld point of the second welding layer can be used to seal the pores formed at the end weld point of the first welding layer, and at the same time, it is convenient to control the welding rhythm and improve the welding efficiency.

In some examples, the end cover has a mounting surface for mounting the seal, and in a projection of the second welding layer on a plane parallel to the mounting surface, adjacent welding points of the second welding layer at least partially overlap.

By making adjacent welds of the second welding layer at least partially overlap, the welding rhythm can be conveniently controlled. The adjacent welds of the second welding layer cooperate with each other to seal the pores formed by the first welding layer while increasing the weld overlap rate, thereby ensuring the sealing performance of the product and improving the product yield.

In some examples, adjacent welding points of the first welding layer are connected.

By partially overlapping adjacent solder joints of the first soldering layer, the overlap rate of the solder joints can be increased, thereby improving the soldering yield of the product.

In some examples, the end cover has a mounting surface for mounting the seal, and in projections of the first welding layer and the second welding layer on a plane parallel to the mounting surface, a total overlap rate of weld points of the first welding layer and weld points of the second welding layer is not less than 75%.

When the overlap rate of the welding points of the first welding layer and the welding points of the second welding layer is not less than 75%, the sealing performance of the weld formed by welding is better, which helps to improve the sealing performance of the joint between the seal and the end cover, thereby improving the product yield.

In some examples, the weld points of the first welding layer are located away from a line connecting one end of the seal to form an outer edge, and the weld points of the first welding layer are located close to a line connecting one end of the seal to form an inner edge; the weld points of the second welding layer are located between the outer edge and the inner edge.

By arranging the second welding layer in the area formed between the outer edge and the inner edge, the weld formed by welding can extend along a predetermined trajectory, which helps to improve the consistency of the appearance of the weld and make the appearance of the product more beautiful.

In some examples, the first trajectory at least partially overlaps with the second trajectory.

The weld points of the first welding layer are distributed along the first track, and the weld points of the second welding layer are distributed along the second track. By partially overlapping the first track and the second track, the overlap rate of the weld points of the second welding layer and the weld points of the first welding layer is higher; the weld formed by the second welding layer and the first welding layer can extend along a relatively close or even overlapping track, thereby making the appearance consistency of the weld better.

In some examples, the distance between adjacent welds of the second welding layer is equal to the distance between adjacent welds of the first welding layer.

When welding to form welds, since the distance between adjacent welds of the second welding layer is equal to the distance between adjacent welds of the first welding layer, the welding rhythm of the first welding layer and the second welding layer is the same during the welding process, which can make the control of the welding operation more convenient; since the spacing between the welds formed by welding is equal, the appearance of the weld formed by welding at different positions remains consistent, which helps to improve the aesthetics of the weld.

In some examples, the first welding layer has a head end welding spot arranged along the first track; the end cover is further formed with a welding cut-in layer formed by welding along a third track, the welding cut-in layer includes a plurality of welding spots distributed along the third track; the welding cut-in layer has a terminal welding spot arranged along the third track;

Adjacent welding points of the welding cut-in layer are connected;

The end welding point of the welding cutting layer is connected to the beginning welding point of the first welding layer.

By providing the welding cut-in layer, a channel for guiding impurities outward can be formed outside the first welding layer, thereby helping to improve welding quality.

In some examples, the welding cut-in layer further has a head end welding spot arranged along the third track; the head end welding spot of the welding cut-in layer is located on a side of the first welding layer away from the sealing member.

When impurities generated by welding move along the welding cut-in layer toward the outside of the first welding layer, the impurities move to the first end welding point of the welding cut-in layer, that is, located outside the first welding layer, and will not affect the first welding layer.

In some examples, the second welding layer has an end welding spot arranged along the second track; the end cover is further formed with a welding cut-out layer formed by welding along a fourth track, the welding cut-out layer includes a plurality of welding spots distributed along the fourth track; the welding cut-out layer has a head end welding spot distributed along the fourth track;

Adjacent welding points of the welded cut-out layer are connected;

The first end welding point of the welding cut-out layer is connected to the last end welding point of the second welding layer.

By providing the welding cut-out layer, a channel for guiding impurities outward can be formed outside the second welding layer, thereby helping to improve welding quality.

In some examples, the weld cut-out layer further has an end weld point arranged along the fourth track; and the end weld point of the weld cut-out layer is located on a side of the second weld layer away from the sealing member.

When impurities generated by welding move along the welding cut-out layer toward the outside of the first welding layer, the impurities move to the end welding point of the welding cut-out layer, that is, located outside the second welding layer, and will not affect the second welding layer.

In some examples, the first welding layer and the second welding layer are disposed around the seal.

The weld formed by welding the first welding layer and the second welding layer is arranged around the sealing member to completely seal the joint between the sealing member and the end cover, thereby improving the sealing performance of the end cover assembly.

Based on the above-mentioned end cover assembly, the present application also proposes an example of a battery cell, including an end cover assembly as described in any of the above items.

By adopting the end cover assembly described in the above example, the sealing performance of the battery cell can be improved and welding defects such as air holes can be avoided.

Based on the above-mentioned battery cell, the present application further proposes an example of an electrical device, wherein the electrical device includes the battery cell as described in the above-mentioned example.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

FIG1 is a partial cross-sectional schematic diagram of an example of the mating position of the sealing member and the end cover of the present application;

FIG2 is a schematic structural diagram of an example of the first welding layer of the present application;

FIG3 is a schematic structural diagram of an example of a cooperation state between a first welding layer and a second welding layer of the present application;

FIG4 is a schematic structural diagram of an example of a welding cut-in layer and a welding cut-out layer of the present application;

FIG5 is a schematic structural diagram of an example of a battery cell of the present application;

FIG. 6 is a schematic structural diagram of an example of an electrical device of the present application.

Description of Figure Numbers:

The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

Detailed ways

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

It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications 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.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. 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 the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that this is inconsistent. The combination of the above technical solutions does not exist and is not within the protection scope required by this application.

The battery cell includes a shell, one end of which is formed with an opening, a bare cell is installed in the shell, and an end cap assembly is provided at the opening of the shell, and the end cap assembly is used to close the opening. The end cap assembly of the battery cell usually reserves a liquid injection hole 51, which can serve as an inlet for injecting electrolyte.

Referring to FIG. 1 , the end cover 50 has a mounting surface for mounting the sealing member 60. The end cover 50 is provided with a liquid injection hole 51. In order to facilitate sealing of the liquid injection hole 51, a receiving groove 52 is recessed on the mounting surface of the end cover 50. The liquid injection hole 51 is provided at the bottom of the receiving groove 52, so that one end of the liquid injection hole 51 is connected to the receiving groove 52, and the other end is connected to the inner surface of the end cover 50. During installation, the glue nail 71 is inserted into the liquid injection hole 51 to seal the liquid injection hole 51. The sealing member 60 is located in the receiving groove 52, and the receiving groove 52 can be used to limit the radial movement of the sealing member 60, and the sealing member 60 is welded to the end cover 50.

The general outline of the existing seal 60 is generally cone-shaped, as shown in FIG1 . In the cross section parallel to the axial direction of the seal 60 , the upper end of the glue nail 71 is provided with a receiving groove 52 , which is used to accommodate the seal 60 . The side wall of the receiving groove 52 is an inclined surface, and the outer annular wall of the seal 60 matches the side wall of the receiving groove 52 , and the end of the outer annular wall of the seal 60 away from the glue nail 71 is close to the inner wall of the receiving groove 52 , so that the seal 60 can be used to fill the receiving groove 52 ; the top surface of the seal 60 is flush with the top surface of the end cover 50 , or the top surface of the seal 60 is slightly higher than the top surface of the end cover 50 . The circular joint between the seal 60 and the end cover 50 is welded so that the seal 60 is welded and fixed on the end cover 50 .

Taking the use of a laser welding device as a welding assembly as an example, when the welding assembly is used for welding, the welding assembly emits a high-energy laser to the joint of the seal 60 and the end cover 50. Under the action of the laser, a liquid metal portion with a certain shape is formed at the joint of the seal 60 and the end cover 50. The liquid metal portion is called a welding molten pool. During the welding process, as the welding assembly moves, the metal at the tail of the molten pool cools and crystallizes to form a weld.

The existing seal 60 is welded by a continuous laser. During the movement of the continuous laser along the preset trajectory, there is a large amount of heat in the welding molten pool, and the electrolyte remaining in the injection hole 51 decomposes into gas under the high heat of the high-energy laser beam; when the seal 60 is welded, a sealed cavity is formed between the seal 60 and the inner wall surface of the receiving groove 52, and the gas remains in the sealed cavity between the seal 60 and the receiving groove 52, resulting in excessive gas pressure in the sealed cavity; high-pressure gas is prone to form pores at the beginning and end of the weld, and because the pores are connected to the sealed cavity, the receiving groove 52 cannot be completely sealed, which leads to product defects in the end cover 50, and the welding yield of the product cannot meet the requirements. At the same time, in order to avoid the formation of pores, the welding speed needs to be reduced in the existing continuous laser welding process to provide sufficient escape time for the gas in the sealed cavity, resulting in a significant reduction in the welding speed, which directly affects the processing efficiency of the battery cell.

The present application aims to solve the problem of easy generation of pores in the welding process of the existing end cap assembly, and proposes an end cap assembly for a battery cell. The battery cell can be a square battery, a cylindrical battery, a special-shaped battery, a soft-pack battery, etc. The battery cell has a shell corresponding to its shape and an end cap assembly corresponding to the shape of the shell.

The shell is a component used to form the internal environment of the battery cell. The internal environment formed by the shell can be used to accommodate the battery cell assembly, electrolyte and other components. An opening is set on the shell, and the internal environment of the battery cell is formed by covering the opening with the end cap 50 at the opening. In some examples, the end cap 50 and the shell are integrally arranged. Specifically, the end cap 50 and the shell can form a common connection surface before other components enter the shell. When the interior of the shell needs to be encapsulated, the end cap 50 is covered with the shell. The shell can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc., or other required shapes. The shape of the shell can be determined according to the specific shape and size of the battery cell assembly. The material of the shell can be copper, iron, aluminum, aluminum alloy, stainless steel, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this.

The end cap 50 is covered at the opening of the shell to isolate the internal environment of the battery cell from the external environment. The shape of the end cap 50 is adapted to the shape of the shell. The end cap 50 can be made of a material with a certain hardness and strength (such as aluminum alloy) to prevent the end cap 50 from deforming when squeezed and collided, thereby helping to improve the structural strength and safety performance of the battery cell. Functional components such as electrode terminals can be provided on the end cap 50. In some examples, a pressure relief mechanism for releasing the internal environmental pressure can also be provided on the end cap 50. The material of the end cap 50 can also be a variety of materials, such as iron, copper, aluminum, aluminum alloy, stainless steel, plastic, etc., and this application does not impose special restrictions on this. In some examples, an insulating layer for isolating the electrical connection components in the shell from the end cap 50 can also be provided on the inner side of the end cap 50 to improve the safety performance of the battery cell.

The seal 60 is welded and fixed on the end cover 50. When welding the end cover 50 and the seal 60, laser welding can be used. For example, a laser pulse welding head can be used as a welding tool. For the convenience of description, the welding tool used for welding is referred to as a welding assembly. The seal 60 can be a sealing pin or other sealing structure that is connected and fixed to the end cover 50 by welding and can seal the injection hole 51.

Please refer to Figures 1, 2 and 3. The end cover assembly described in this example includes an end cover 50 and a sealing member 60. The end cover 50 is provided with an injection hole 51, and the sealing member 60 is sealed and matched with the injection hole 51. The edge of the sealing member 60 is fixed to the end cover 50 by a first welding layer 10 formed by welding along a first track, and the first welding layer 10 includes a plurality of welding points distributed along the first track. The edge of the sealing member 60 is also fixed to the end cover 50 by a second welding layer 20 formed by welding along a second track. The second welding layer 20 includes a plurality of welding points distributed along the second track. At least part of the welding points of the second welding layer 20 are connected to the welding points of the first welding layer 10, so that the first welding layer 10 and the second welding layer 20 form a continuous weld.

The first welding layer 10 includes a plurality of welding spots distributed along the first track. When the welding assembly moves along the first track, welding is performed to form the first welding layer 10. Adjacent welding spots of the first welding layer 10 may be spaced apart from each other or partially overlapped.

The second welding layer 20 includes a plurality of welding spots distributed along the second track, and the welding spots of the second welding layer 20 at least partially overlap with the welding spots of the first welding layer 10 , so that the second welding layer 20 can form a continuous weld with the first welding layer 10 .

Assume that the surface on the end cover 50 for mounting the seal 60 is the mounting surface, and the surface parallel to the mounting surface is the projection surface. The overlap mentioned in the present application refers to that the graphics formed by projecting the first welding layer 10 and/or the second welding layer 20 onto the projection surface have overlapping parts.

The first track and the second track are adapted to the shape of the sealing member 60. When forming the first welding layer 10, the first welding spot formed by welding along the first track is the first end welding spot of the first welding layer 10, and the last welding spot is the end welding spot of the first welding layer 10; the first welding spot formed along the second track is the first end welding spot of the second welding layer 20, and the last welding spot is the end welding spot of the second welding layer 20.

In some examples, the first track and the second track at least partially overlap. In order to facilitate the control of the operating efficiency of the welding assembly, further, the first track overlaps the second track. Taking the shapes shown in Figures 2 and 3 as an example, the ω direction shown is the first direction, the first direction is the first track direction and the second track direction, and the first welding layer 10 and the second welding layer 20 are both composed of multiple welding points formed by welding along the ω direction. Since the first welding layer 10 and the second welding layer 20 can be welded along the same track, the weld formed by welding can extend along the path corresponding to the first track, thereby making the weld formed by welding more beautiful.

When the first welding layer 10 is formed by welding along the first track, the first welding layer 10 has a first end welding spot and a terminal welding spot arranged along the first track. When the second welding layer 20 is formed by welding along the second track, the second welding layer 20 has a first end welding spot and a terminal welding spot arranged along the second track.

When the first welding layer 10 and the second welding layer 20 form a continuous weld, the second welding layer 20 and the first welding layer 10 weld and fix the seal 60 to the end cover 50, thereby achieving fixation between the seal 60 and the end cover 50. Since the welding assembly is welded along the first track, when the welding assembly is welded along the first track to form the first welding layer 10, the welding points of the first welding layer 10 are formed in sequence. Compared with the existing continuous welding method, more escape time can be provided for the gas in the sealed cavity between the seal 60 and the inner wall surface of the receiving groove 52, thereby reducing the formation of pores at the end of the first welding layer 10. When the welding assembly is welded from the head end to the end end in sequence, the welding point at the head end of the first welding layer 10 has solidified; secondary welding is performed on the first welding layer 10 to form the second welding layer 20, and the pores at the end of the first welding layer 10 are sealed by the second welding layer 20, thereby avoiding the problem that the closed cavity cannot be completely sealed due to the existence of pores, thereby helping to solve the problem of reduced welding yield.

In some examples, adjacent welds of the first welding layer 10 are partially connected to form a continuous weld of the first welding layer 10. The welds of the second welding layer 20 at least partially overlap with the welds of the first welding layer 10 to form a secondary welding weld, and when welded to the end welds of the first welding layer 10, the welds of the second welding layer 20 can close the pores formed at the end of the first welding layer 10.

Furthermore, in some examples, when welding to form a base weld, the existing pulse welding control device can be used to control the running speed of the welding assembly along the first track and the welding frequency of the welding assembly so that the first welding layer 10 During the welding process, after the previous weld is formed, the welding molten pool of the weld is solidified before welding the next weld, so that the welding molten pools of adjacent welds do not interfere with each other. The solidification time of a common welding molten pool is 10-30ms. Therefore, the movement speed and welding frequency of the welding assembly can be controlled by an existing pulse welding control device so that adjacent welding molten pools do not interfere with each other. By controlling the movement speed and welding frequency of the welding assembly, the gas between the seal 60 and the inner wall surface of the receiving groove 52 during the welding process can have sufficient time to escape, thereby reducing the generation of pores. Further, in some examples, when controlling the welding assembly to weld and form the first welding layer 10 and the second welding layer 20, the welding assembly can be kept on after the welding of the first welding layer 10 is completed, so that the welding assembly continues to weld along the second track to form the second welding layer 20; wherein, the movement speed and welding frequency of the welding assembly when welding the second welding layer 20 can be the same as the movement speed and welding frequency when forming the first welding layer 10, so as to reduce the change and debugging of the welding assembly and facilitate the control of the welding assembly.

In some examples, the adjacent welds of the first welding layer 10 are arranged at intervals, and the welds of the second welding layer 20 are located between the adjacent welds of the first welding layer 10, so as to weld and seal the area between the adjacent welds of the first welding layer 10. Since the adjacent welds of the first welding layer 10 are arranged at intervals, during the process of forming the first welding layer 10, the gaps between the adjacent welds can be used to form a channel for gas to escape, thereby allowing sufficient time for the high-pressure gas between the seal 60 and the inner wall surface of the receiving groove 52 to escape. When the second welding layer 20 completely seals the gaps between the adjacent welds of the first welding layer 10, the first welding layer 10 and the second welding layer 20 form a continuous weld.

In some examples, the number of second welding layers 20 is multiple layers, and the multiple layers of second welding layers 20 can be stacked in sequence in the thickness direction of the end cover 50; in some examples, in the top view of the end cover 50, the multiple layers of second welding layers 20 can also be staggered, so that the multiple layers of second welding layers 20 can cooperate with the first welding layer 10 to form a continuous weld.

In some examples, the distance between adjacent welding points of the first welding layer 10 is equal to the distance between adjacent welding points of the second welding layer 20. Since the first welding layer 10 and the second welding layer 20 are both composed of multiple welding points, by making the spacing between adjacent welding points of the second welding layer 20 and the adjacent welding points of the first welding layer 10 equal, after welding is completed, the shapes of the welding points formed by the first welding layer 10 and the second welding layer 20 are consistent, so that the consistency of the weld formed by welding is relatively better, and then the shape of the continuous weld formed by welding can be made relatively more beautiful; when performing welding operations, it is also convenient to control the welding rhythm.

Please refer to FIG. 3 , in some examples, the welding points of the first welding layer 10 and the welding points of the second welding layer 20 are staggered with each other.

Two adjacent welding spots of the second welding layer 20 are used to perform secondary welding on both sides of the welding spots of the first welding layer 10 along the second track direction to prevent gaps between adjacent welding spots of the first welding layer 10 from causing welding leaks.

Please refer to FIG. 3. In some examples, the number of the second welding layer 20 is one layer, and the welding points of the second welding layer 20 and the welding points of the first welding layer 10 are mutually staggered, so that each welding point of the second welding layer 20 can overlap with two adjacent welding points of the first welding layer 10 at the same time, so that the welding points of the second welding layer 20 can form a continuous weld with the welding points of the first welding layer 10. For example, for any welding point n of the first welding layer 10 in FIG. 3, welding point N and welding point N+1 of the second welding layer 20 partially overlap with welding point n respectively.

In some examples, the difference from the previous example is that the number of second welding layers 20 is at least two layers. Taking the number of second welding layers 20 as two layers as an example, it includes but is not limited to the following situations: first, weld point n of the first welding layer 10 partially overlaps with weld point N and weld point N+1 of the first layer of second welding layer 20 as shown in Figure 3; second, weld point n at least partially overlaps with two adjacent weld points of the second layer of second welding layer 20; third, weld point n partially overlaps with a weld point of the first layer of second welding layer 20, and partially overlaps with a weld point of the second layer of second welding layer 20; fourth, weld point n of the first welding layer 10 completely overlaps with a weld point of the first layer of second welding layer 20, and partially overlaps with two weld points of the second layer of second welding layer 20.

In some examples, the number of the second welding layer 20 is multiple layers, and the first welding layer 10 and the multiple layers of second welding layers 20 form a continuous weld.

The number of the second welding layer 20 can be two, three or even more layers. By setting multiple layers of the second welding layer 20, the second welding layer 20 can cooperate with the first welding layer 10 to form a continuous weld at the joint between the seal 60 and the end cover 50, thereby improving the sealing of the joint between the seal 60 and the end cover 50. Further, in some examples, along the thickness direction of the end cover 50, the multiple layers of the second welding layer 20 can be stacked in sequence above the first welding layer 10, and the multiple layers of the second welding layer 20 cooperate with each other, so that the first welding layer 10 and the multiple layers of the second welding layer 20 can form a continuous and reliable weld. In some examples, on the plane where the upper surface of the end cover 50 is located, the multiple layers of the second welding layer 20 are staggered with each other, so that the welding points of the multiple layers of the second welding layer 20 are staggered with each other, and the multiple layers of the second welding layer 20 cooperate with the base layer to form a continuous weld.

In some examples, the welding points of the second welding layer 20 adjacent to the first welding layer 10 are at least partially offset from the welding points of the first welding layer 10 .

The staggered arrangement means that the geometric centers of the weld points of the first welding layer 10 and the weld points of the second welding layer 20 adjacent to the first welding layer 10 are staggered. As shown in FIG3, there is a second welding layer 20 on top of the first welding layer 10, wherein the weld point n on the first welding layer 10 corresponds to the weld points N and N+1 on the second welding layer 20, wherein the weld point N and the weld point N+1 are at least partially staggered with the weld point n, so that the weld points of the second welding layer 20 adjacent to the first welding layer 10 can be used for the gaps between the weld points of the first welding layer 10, thereby avoiding the existence of gaps between the weld points of the first welding layer 10. When there is a second layer of the second welding layer 20 on top of the second welding layer 20 as shown in FIG3, the second layer of the second welding layer 20 is The welding points of the welding layer 20 may correspond to the welding points of the first welding layer 10, or may be mutually offset with the welding points of the first welding layer 10, so that the first welding layer 10 and the multi-layer second welding layer 20 can cooperate to form a continuous weld. Since the multi-layer second welding layer 20 can cooperate with each other, the adjacent welding points of the first welding layer 10 are supplemented with welding, which can improve the sealing of the welding, and at the same time, the second welding layer 20 completely closes the pores at the end of the first welding layer 10, further improving the welding sealing of the joint between the sealing member 60 and the end cover 50.

In some examples, the welding points of adjacent second welding layers 20 are at least partially staggered.

The geometric centers of the welds of the adjacent second welding layers 20 are staggered so that the welds of the adjacent second welding layers 20 match the welds of the first welding layer 10, and the gap at the joint of the seal 60 and the end cover 50 is completely sealed, thereby improving the sealing of the battery cell end cover assembly. Further, in some examples, there is a gap between the adjacent welds of the first welding layer 10, and the multiple second welding layers 20 are used to weld and seal the positions between the adjacent welds of the first welding layer 10. In some examples, the adjacent welds of the first welding layer 10 partially overlap, and the welds of the second welding layer 20 adjacent to the first welding layer 10 partially overlap with the adjacent two welds of the first welding layer 10. Further, the second second welding layer 20 can weld and seal the gap between the adjacent welds of the first first welding layer 10.

In some examples, the first welding layer 10 has an end welding spot arranged along the first track; the second welding layer 20 has a head welding spot arranged along the second track; the head welding spot of the second welding layer 20 is at least partially connected to the end welding spot of the first welding layer 10.

During welding, the first end welding point of the second welding layer 20 can be used to seal the pores generated at the end welding point of the first welding layer 10, thereby improving the sealing of the weld.

When the welding assembly is used for welding, after the welding assembly forms the first welding layer 10 by welding along the first track, the welding assembly can continue to weld along the second track to form the second welding layer 20 without stopping, so as to shorten the downtime between the first welding layer 10 and the second welding layer 20 and improve the processing efficiency. In some examples, the spacing between adjacent welding points of the first welding layer 10 is equal to the spacing between adjacent welding points of the second welding layer 20, so that when welding to form the first welding layer 10 and the second welding layer 20, the welding assembly does not need to stop and adjust parameters, and performs continuous welding operations to accelerate the welding process.

Please refer to FIG. 3 , in some examples, the end cover 50 has a mounting surface for mounting a seal, and in a projection of the second welding layer 20 on a plane parallel to the mounting surface, adjacent welding points of the second welding layer 20 at least partially overlap.

When the second welding layer 20 is a single layer, as shown in FIG3 , the adjacent welding points of the second welding layer 20 partially overlap, and the welding points of the second welding layer 20 and the welding points of the first welding layer 10 form a continuous weld. The welding point N of the second welding layer 20 and the welding points N+1 and N-1 adjacent to the welding point N, wherein the welding point N partially overlaps with the welding point N+1 and the welding point N-1 respectively. When the second welding layer 20 is a multi-layer, the adjacent welding points in the same second welding layer 20 can be partially overlapped. The welding points of the second welding layers 20 of adjacent layers are staggered with each other so that the multi-layer second welding layers 20 and the first welding layer 10 form a continuous weld, and the second welding layer 20 closes the pores formed at the end of the first welding layer 10.

Referring to FIG. 2 , in some examples, adjacent welding points of the first welding layer 10 are connected.

As shown in FIG2 , the welding spot n of the first welding layer 10 and the welding spots n+1 and n-1 adjacent to the welding spot n are respectively overlapped with the welding spots n+1 and n-1 to form a continuous weld of the first welding layer 10. When the welding assembly is welding, the existing welding control system can be used to control the movement speed and welding frequency of the welding assembly, so that the molten pool of the welding spot n solidifies before welding to form the welding spot n+1, thereby avoiding interference with the molten pool of the adjacent welding spots when the molten pool of the welding spot n is not solidified.

Please refer to Figure 3. In some examples, the line connecting the welding points of the first welding layer 10 away from one end of the seal 60 forms an outer edge, and the line connecting the welding points of the first welding layer 10 close to one end of the seal 60 forms an inner edge; the welding points of the second welding layer 20 are located between the outer edge and the inner edge.

Taking the first welding layer 10 as shown in FIG3 as an example, the ring formed by the line connecting the welding points of the first welding layer 10 away from the end of the sealing member 60 is the outer edge of the first welding layer 10; the ring formed by the line connecting the welding points of the first welding layer 10 close to the end of the sealing member 60 is the inner edge of the first welding layer 10, and the inner edge and the outer edge enclose a ring area, and the second welding layer 20 is located in the ring area. Since the second welding layer 20 and the first welding layer 10 are located inside the preset ring area, the weld formed by the second welding layer 20 and the first welding layer 10 can extend along the preset area, thereby making the trajectory of the weld relatively constant, and the appearance of the end cap assembly formed by welding is more controllable and relatively more beautiful. Since the second welding layer 20 can cover the gaps between adjacent welding points of the first welding layer 10, it is avoided that there is an unwelded area between adjacent welding points of the first welding layer 10, and leakage welding is prevented.

In some examples, the end cover has a mounting surface for mounting a seal, and in projections of the first welding layer 10 and the second welding layer on a plane parallel to the mounting surface, a total overlap rate of weld points of the first welding layer 10 and the second welding layer 20 is not less than 75%.

The total overlap rate refers to the ratio of the overlap area of the second welding layer 20 and the first welding layer 10 to the total area of the weld formed by the second welding layer 20 and the first welding layer 10 in the projection of the first welding layer 10 and the second welding layer 20 on the plane where the upper surface of the end cover 50 is located. By making the total overlap rate of the welding points of the first welding layer 10 and the welding points of the second welding layer 20 not less than 75%, the welding seal at the joint of the sealing member 60 and the end cover 50 can be ensured, thereby ensuring the sealing effect.

In some examples, the first trajectory at least partially overlaps the second trajectory.

When there is a second welding layer 20, the second track of the second welding layer 20 is adjacent to the first track, or the second track of the second welding layer 20 overlaps with the first track to ensure that the welded spot is close to the welded spot of the first welding layer 10. In some examples, the number of the second welding layers 20 is multiple layers, the multiple layers of second welding layers 20 are respectively distributed along the second track, and the welding points of adjacent second welding layers 20 are staggered with each other, so that the first welding layer 10 and the multiple layers of second welding layers 20 form a continuous weld.

Referring to FIG. 2 and FIG. 3 , in some examples, the distance between adjacent welding points of the second welding layer 20 is equal to the distance between adjacent welding points of the first welding layer 10 .

When welding, when forming the first welding layer 10 and the second welding layer 20, the welding assembly can use the same operating parameters, that is, the same movement speed and welding frequency, so there is no need to additionally adjust the operating state of the welding assembly. Further, in some examples, after completing the welding of the first welding layer 10, the welding assembly does not stop, and continues to weld to form the adjacent second welding layer 20 to speed up the welding process.

Please refer to Figure 4. In some examples, the first welding layer 10 has a head end weld point set along the first track; a welding cut-in layer 30 formed by welding along a third track is also formed on the end cover 50, and the welding cut-in layer 30 includes a plurality of weld points distributed along the third track; the welding cut-in layer 30 has an end weld point set along the third track; adjacent weld points of the welding cut-in layer 30 are connected; and the end weld point of the welding cut-in layer 30 is connected to the head end weld point of the first welding layer 10.

During the welding operation, a welding pool is formed at the joint of the seal 60 and the end cover 50. The welding pool contains liquid metal. During the movement of the welding assembly, the metal at the tail of the pool cools and crystallizes to form a weld. There may be some impurities formed by welding in the pool. By forming the welding cut-in layer 30, a channel for guiding impurities can be formed outside the first welding layer 10, so that the impurities generated during the welding process are guided to the outside of the first welding layer 10.

The third track may be a direction tangent to the first track of the first welding layer 10, as shown in the second direction D1 in FIG4, and the welding assembly moves along the second direction D1 toward the sealing member 60, and when it reaches the joint between the sealing member 60 and the end cover 50, the welding assembly starts welding the first welding layer 10. In this example, the movement speed and welding frequency of the welding assembly may be controlled by an existing welding control system so that adjacent welding points of the welding cut-in layer 30 are connected to form a channel for guiding impurities outward.

Furthermore, in some examples, the welding cut-in layer 30 also has a head end welding point arranged along the third track; the head end welding point of the welding cut-in layer 30 is located on a side of the first welding layer 10 away from the sealing member 60 .

Since the welding cut-in layer 30 is used to form a channel to guide impurities outward, when the welding point of the first end of the welding cut-in layer 30 is connected to the outside of the first welding layer 10 and the second welding layer 20, the impurities formed during the welding process of the first welding layer 10 can be guided out of the welding point.

Please continue to refer to FIG. 4. In some examples, the second welding layer 20 has an end welding spot arranged along the second track; the end cover 50 is further formed with a welding cut-out layer 40 formed by welding along the fourth track, and the welding cut-out layer 40 includes a plurality of welding spots distributed along the fourth track; the welding cut-out layer 40 has a head end welding spot distributed along the fourth track; The adjacent welding points are connected; the first end welding point of the welding cut layer 40 is connected to the end welding point of the second welding layer 20.

By forming the welding cut-out layer 40 , a channel for guiding impurities can be formed outside the second welding layer 20 , so that impurities generated during welding are guided toward the outside of the second welding layer 20 .

The fourth track may be a direction tangent to the second track of the second welding layer 20, as shown in the third direction D2 in FIG4 , and the welding assembly moves along the third direction D2 in a direction away from the sealing member 60. In this example, the movement speed and welding frequency of the welding assembly may be controlled by an existing welding control system so that adjacent welding points of the welding cut-out layer 40 are connected to form a channel for guiding impurities outward.

In some examples, the weld cut-out layer 40 further has an end weld point disposed along a fourth track; the end weld point of the weld cut-out layer 40 is located at a side of the second weld layer 20 away from the sealing member 60 .

Since the welding cut-out layer 40 is used to form a channel to guide impurities outward, when the end weld of the welding cut-out layer 40 is connected to the first welding layer 10 and the outside of the second welding layer 20, impurities formed during the welding process of the second welding layer 20 can be guided out of the weld.

In some examples, with the line connecting the geometric center of the head end weld point of the first welding layer 10 and the center of the seal 60 as the axis of symmetry, the welding cut-in layer 30 and the welding cut-out layer 40 are relatively symmetrically arranged to make the weld formed by welding more beautiful and to facilitate the control of the movement trajectory of the welding assembly.

In some examples, the first welding layer 10 and the second welding layer 20 are disposed around the seal 60 .

The weld formed by the combination of the first welding layer 10 and the second welding layer 20 is arranged around the seal 60, so that a continuous weld is formed at the joint of the seal 60 and the end cover 50, thereby sealing the joint of the seal 60 and the end cover 50. Since the second welding layer 20 can close the pores formed by the first welding layer 10, the sealing performance of the joint of the seal 60 and the end cover 50 can be effectively improved.

Based on the above end cap assembly, the present application also proposes an example of a welding assembly. The welding assembly is used to weld the end cap assembly as in any of the above examples, the welding assembly includes a pulse welding head with a movement speed of S and a welding frequency of P, the first welding layer 10 and/or the second welding layer 20 are formed by pulse welding of the pulse welding head, S is not less than 15 mm/s and not more than 80 mm/s, and P is not less than 25 Hz and not more than 140 Hz.

The welding assembly uses a pulse welding head for pulse welding. The pulse welding head can move along the first track, the second track, the third track or the fourth track to form a continuous weld at the joint of the seal 60 and the end cover 50. Further, in some examples, after the first welding layer 10 is welded, the pulse welding head does not stop, but continues to run along the second track to weld and form the second welding layer 20, so that the first end welding point of the second welding layer 20 corresponds to the end welding point of the first welding layer 10, so that the second welding layer 20 can seal the pores at the end of the first welding layer 10.

The welding assembly described in this example may also include other functional components. For example, the welding assembly may also use an existing welding control system, using a motor and other components to drive the pulse welding head to move along a preset trajectory, so that the pulse welding head with the above-mentioned movement speed and welding frequency can perform welding operations along the preset trajectory. In this example, other functional components of the welding assembly are not limited. It should be noted that although the example of the welding assembly in this example lists some components, it only illustrates a component for implementing pulse welding for ease of understanding.

The movement speed of the pulse welding head is 15mm/s≤S≤80mm/s, and the corresponding welding frequency is 25Hz≤P≤140Hz. The welding frequency of the pulse welding head can be 25Hz, 26Hz, 30Hz, 40Hz, 50Hz, 60Hz, 70Hz, 80Hz, 90Hz, 100Hz, 110Hz, 120Hz, 130Hz, 140Hz, and the corresponding movement speed of the pulse welding head can be 15mm/s, 18mm/s, 20mm/s, 26mm/s, 31mm/s, 36mm/s, 41mm/s, 46mm/s, 51mm/s, 58mm/s, 64mm/s, 70mm/s, 74mm/s, 80mm/s. The above movement speed and welding frequency of the pulse welding head are only examples and are not limitations of the present application. In this example, the movement speed of the pulse welding head is proportional to its welding frequency to control the welding beat. Since the first welding layer 10 and the second welding layer 20 form a continuous weld, the quality of the weld formed by welding is adapted to the welding rhythm of the pulse welding head by controlling the movement speed and welding frequency of the pulse welding head.

Further, in some examples, when the operating speed of the pulse welding head is 80 mm/s, the corresponding welding frequency is 140 Hz.

During the pulse welding process, the solidification time of the welding pool of the welding point is about 10-30ms. By controlling the pulse welding head according to the above-mentioned movement speed and welding frequency, the interval time between adjacent welding points during the welding process can meet the time required for the welding pool to solidify, thereby avoiding interference between adjacent welding pools.

Please refer to FIG. 5 . Based on the above end cover assembly, the present application further provides an example of a battery cell 100 . The battery cell 100 includes the end cover assembly as described in any of the above examples.

It is worth noting that since the examples of the battery cells of the present application are based on the examples of the end cap assemblies described above, the examples of the battery cells of the present application include all the technical solutions of all the examples of the end cap assemblies described above, and the technical effects achieved are also exactly the same, which will not be described in detail here. The battery cells may be cylindrical, rectangular, or in other shapes. The battery cell 100 has a housing 110, and a battery cell 120 and other functional components are arranged inside the housing 110. The prior art can be referred to and will not be described in detail here.

Based on the above-mentioned battery cell, the present application further proposes an example of an electrical device, and the electrical device includes the battery cell 110 as in the above-mentioned example.

The electrical equipment includes but is not limited to: mobile phones, portable devices, laptops, battery cars, electric vehicles, ships, spacecraft, electric toys and electric tools, etc. By using the above battery cells, the stability of power supply to the electrical equipment can be effectively guaranteed, thereby improving the safety of the electrical equipment and user experience. Please refer to Figure 6, which shows an electrical equipment This is an example of an electric vehicle 1000, wherein the electric vehicle 1000 has a controller 200 and a motor 300. The electric vehicle 1000 may also include other functional components, which may be referred to in the prior art and will not be described in detail.

In some examples, the electrical device may include a battery cell 100 as described in any of the above examples.

In some examples, multiple battery cells 100 described in any of the above examples are combined to form a battery pack, and the battery pack is installed on an electrical device. The battery pack can be composed of battery cells 100 connected in series; the battery pack can also be composed of battery cells 100 connected in parallel; the battery pack can also connect multiple battery cells 100 in a mixed manner of series and parallel to each other, so as to adapt to the use requirements of specific electrical devices as needed.

The technical solution of the present application is comprehensively described below in conjunction with Figures 1 to 4. The end cap assembly of the present application includes an end cap 50 and a sealing member 60. The end cap 50 is provided with an injection hole 51 for injecting electrolyte, and the sealing member 60 is used to seal the injection hole 51. A receiving groove 52 for accommodating the sealing member 60 is provided on the end cap 50. The sealing member 60 is mounted on the end cap 50 and placed in the receiving groove 52. A glue nail 71 is provided in the injection hole 51 to close the injection hole 51. A joint is formed between the sealing member 60 and the upper edge of the receiving groove 52. The welding operation is performed by a pulse welding head of a welding assembly with a moving speed of S and a welding frequency of P, wherein S is not less than 15 mm/s and not more than 80 mm/s, and P is not less than 25 Hz and not more than 140 Hz; the greater the moving speed S of the pulse welding head, the greater the corresponding welding frequency P. Optionally, the moving speed of the pulse welding head is selected to be 80 mm/s and the welding frequency is 140 Hz, so that the adjacent welding molten pools have sufficient solidification time. The pulse welding head welds the joint of the seal 60 and the end cover 50 to form a first welding layer 10 and a second welding layer 20, and the first welding layer 10 and the second welding layer 20 form a continuous weld so that the joint of the seal 60 and the end cover 50 is sealed by the weld formed by welding. By controlling the moving speed and welding frequency of the pulse welding head, the welding beat is controlled and the welding efficiency is improved. At the same time, the moving speed of the pulse welding head is proportional to its welding frequency, so that the welding molten pools of adjacent welding points formed during the welding process do not interfere with each other. Since the second welding layer 20 can seal the pores formed by the first welding layer 10, the problem of pores at the end of the weld due to the existing continuous welding can be avoided, and the welding sealing performance of the joint between the seal 60 and the end cover 50 can be effectively improved. In the continuous weld described in the present application, the overlap rate of the first welding layer 10 and the second welding layer 20 in the projection of the upper surface of the end cover 50 is not less than 75%, so as to ensure the welding sealing performance. The second welding layer 20 in the present application can be a single layer or multiple layers. In order to improve the consistency and aesthetics of the weld, the second welding layer 20 can be stacked in sequence above the first welding layer 10, so that the welding point forms a weld extending along a fixed track, thereby improving the aesthetics of the weld.

The above description is only an optional example of the present application, and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly/indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims (19)

1. An end cap assembly is used for a battery cell, the end cap assembly comprises an end cap and a sealing member, the end cap is provided with a liquid injection hole, the sealing member is in sealing cooperation with the liquid injection hole; wherein,

   The edge of the sealing member is fixed to the end cover through a first welding layer formed by welding along a first track, wherein the first welding layer includes a plurality of welding points distributed along the first track;

   The edge of the sealing member is also fixed to the end cover by a second welding layer formed by welding along a second track; the second welding layer includes a plurality of welding points distributed along the second track;

   At least part of the welding spots of the second welding layer are connected to the welding spots of the first welding layer, so that the first welding layer and the second welding layer form a continuous weld.
2. The end cover assembly according to claim 1, wherein the welding points of the first welding layer and the welding points of the second welding layer are staggered with each other.
3. The end cover assembly according to claim 1 or 2, wherein the number of the second welding layers is multiple layers, and the first welding layer and the multiple layers of the second welding layers form a continuous weld.
4. The end cap assembly of claim 3, wherein the weld points of the second welding layer adjacent to the first welding layer are at least partially offset from the weld points of the first welding layer.
5. The end cover assembly according to claim 3 or 4, wherein adjacent welding points of the second welding layer are at least partially staggered.
6. The end cover assembly according to any one of claims 1 to 5, wherein the first welding layer has an end weld point arranged along the first track, the second welding layer has a head end weld point arranged along the second track, and the head end weld point of the second welding layer is at least partially connected to the end weld point of the first welding layer.
7. The end cover assembly according to any one of claims 1 to 6, wherein the end cover has a mounting surface for mounting the seal, and in a projection of the second welding layer on a plane parallel to the mounting surface, adjacent welding points of the second welding layer at least partially overlap.
8. The end cap assembly according to any one of claims 1 to 7, wherein adjacent welds of the first welding layer are connected.
9. The end cover assembly according to any one of claims 1 to 8, wherein the end cover has a mounting surface for mounting the seal, and in projections of the first welding layer and the second welding layer on a plane parallel to the mounting surface, the total overlap rate of the welding points of the first welding layer and the welding points of the second welding layer is not less than 75%.
10. The end cap assembly according to any one of claims 1 to 9, wherein the weld points of the first welding layer are far away A line connecting one end of the seal forms an outer edge, and a line connecting the welding points of the first welding layer close to one end of the seal forms an inner edge; the welding points of the second welding layer are located between the outer edge and the inner edge.
11. The end cap assembly of any one of claims 1 to 10, wherein the first trajectory at least partially overlaps the second trajectory.
12. The end cap assembly according to any one of claims 1 to 11, wherein the distance between adjacent welds of the second weld layer is equal to the distance between adjacent welds of the first weld layer.
13. The end cap assembly according to any one of claims 1 to 12, wherein:

    The first welding layer has a head end welding spot arranged along the first track;

    The end cover is also provided with a welding cut-in layer formed by welding along the third track, wherein the welding cut-in layer includes a plurality of welding points distributed along the third track; the welding cut-in layer has an end welding point arranged along the third track;

    Adjacent welding points of the welding cut-in layer are connected;

    The end welding point of the welding cutting layer is connected to the beginning welding point of the first welding layer.
14. The end cover assembly as described in claim 13, wherein the welding cut-in layer also has a head end weld point arranged along the third track; the head end weld point of the welding cut-in layer is located on a side of the first welding layer away from the sealing member.
15. The end cap assembly according to any one of claims 1 to 14, wherein:

    The second welding layer has end welding spots arranged along the second track;

    The end cover is also provided with a welding cut-out layer formed by welding along a fourth track, wherein the welding cut-out layer includes a plurality of welding points distributed along the fourth track; the welding cut-out layer has a head end welding point distributed along the fourth track;

    Adjacent welding points of the welded cut-out layer are connected;

    The first end welding point of the welding cut-out layer is connected to the last end welding point of the second welding layer.
16. The end cap assembly as claimed in claim 15, wherein the weld cut-out layer further has an end weld point arranged along the fourth track; and the end weld point of the weld cut-out layer is located on a side of the second weld layer away from the seal.
17. The end cap assembly of any one of claims 1 to 16, wherein the first weld layer and the second weld layer are disposed around the seal.
18. A battery cell, comprising the end cap assembly according to any one of claims 1 to 17.
19. An electrical device, comprising the battery cell as claimed in claim 18.