WO2023070288A1

WO2023070288A1 - End cap assembly, battery cell and preparation method therefor, and battery, and power consuming device

Info

Publication number: WO2023070288A1
Application number: PCT/CN2021/126216
Authority: WO
Inventors: 陈新祥; 林蹬华; 郑于炼; 王鹏; 金海族
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2023-05-04
Also published as: CN117461193A; CN219123345U

Abstract

Provided in the embodiments of the present application is an end cap assembly of a battery cell, the end cap assembly comprising: an end cap, which is provided with a first electrode leading-out hole and a first positioning structure surrounding the first electrode leading-out hole, the first positioning structure having a first protrusion, which faces toward the interior of the battery cell in the thickness direction of the end cap, and a first groove being formed on the side of the first protrusion away from the interior of the battery cell; an insulating member, which is arranged on the side of the end cap away from the interior of the battery cell, the insulating member having a second electrode leading-out hole corresponding to the first electrode leading-out hole, and being provided with a second positioning structure, the second positioning structure having a second protrusion, which is fitted with the first groove, and the first electrode leading-out hole and the second electrode leading-out hole being used for leading out an electrode terminal; and a seal, which is configured for sealing the first electrode leading-out hole and is arranged in the first electrode leading-out hole and the second electrode leading-out hole, wherein the first positioning structure and the second positioning structure are configured to press the seal in a direction perpendicular to the thickness of the end cap.

Description

End cap assembly, battery cell and preparation method thereof, battery and electrical device

technical field

The present application relates to the field of battery technology, in particular to an end cap assembly, a battery cell and a preparation method thereof, a battery and an electrical device.

Background technique

As an important energy conversion device, batteries have been widely used in electronic equipment, vehicles and other fields. With the development of battery technology, in addition to improving the energy density of batteries, battery life is a problem that cannot be ignored.

The sealing of the battery cell has an important impact on the life of the battery. For example, when the sealing of the battery is poor, it will cause the battery to leak or gas, thereby reducing the life of the battery and affecting the electrochemical performance of the battery. Therefore, how to improve the sealing performance of the battery is a problem to be solved.

Contents of the invention

The embodiment of the present application provides an end cover assembly, a battery cell, a battery, an electrical device, a method for preparing a battery cell, and a battery cell manufacturing equipment, which can effectively improve the sealing performance of the battery cell, thereby improving the battery life. life and chemical properties.

In the first aspect, the embodiment of the present application provides an end cover assembly, including: an end cover, the end cover is provided with a first electrode lead-out hole, and the end cover is provided with a first positioning hole surrounding the first electrode lead-out hole. structure, the first positioning structure has a first protrusion facing the inside of the battery cell along the thickness direction of the end cover, and the first protrusion is formed with a first protrusion on the side away from the inside of the battery cell. A groove; an insulating member, disposed on the side of the end cap away from the interior of the battery cell, the insulating member has a second electrode drawing hole corresponding to the first electrode drawing hole, the insulating member A second positioning structure is provided, and the second positioning structure has a second protrusion matched with the first groove, and the first electrode lead-out hole and the second electrode lead-out hole are used to lead out electrode terminals; sealing A component, used to seal the first electrode lead-out hole, is arranged in the first electrode lead-out hole and the second electrode lead-out hole; wherein, the first positioning structure and the second positioning structure are used for The seal is pressed against the direction perpendicular to the thickness of the end cap.

In this embodiment, a first positioning structure is provided around the first electrode lead-out hole of the end cover, and a second positioning structure is provided around the second electrode lead-out hole of the insulating member to cooperate with the first positioning structure. On the one hand, the first positioning structure Cooperate with the second positioning structure to facilitate accurate positioning during the assembly process of the end cover assembly and reduce the probability of offset during assembly of the end cover assembly; on the other hand, the cooperation between the first positioning structure and the second positioning structure makes it possible to set the The seals in the first electrode lead-out hole and the second electrode lead-out hole are simultaneously pressed by the first positioning structure and the second positioning structure in the direction perpendicular to the thickness of the end cover, which increases the resistance of the seal in the direction perpendicular to the thickness of the end cover When the electrode terminal is subjected to an external force perpendicular to the thickness direction of the end cover, the first positioning structure and the second positioning structure jointly bear the external force transmitted by the seal, compared with the case where the seal is only pressed by the end cover , the force-bearing area of the seal in this direction is increased, and the possibility of deformation or misalignment is reduced, thereby reducing the probability of electrode terminal leakage and air leakage, and effectively improving the battery life and electrochemical performance.

In some embodiments, the thickness of the bottom wall of the first groove is equal to the thickness of the end cap.

In this embodiment, the bottom wall of the first groove has the same thickness as that of the end cover, that is, the first groove is directly processed by a stamping process without complicated preparation process, and the process is simple and easy to produce, which helps to improve the thickness of the end cover. Component productivity.

In some embodiments, the thickness of the bottom wall of the first groove is smaller than the thickness of the end cap.

In this embodiment, the thickness of the bottom wall of the first groove is smaller than the thickness of the end cap, that is, the first groove can be obtained by machining between cutting processes, without complicated preparation process, and the process is simple and convenient for production, which helps to improve Productivity of end cap assemblies.

In some embodiments, the end cap assembly further includes: a metal terminal plate disposed on a side of the insulating member away from the end cap, the metal terminal plate is used for connecting with the electrode terminals, the A third positioning structure is provided on the side of the metal terminal plate facing the insulating member; wherein, a fourth positioning structure matched with the third positioning structure is provided on a side of the insulating member away from the end cover.

In some embodiments, the third positioning structure is a platform-shaped raised structure.

In this embodiment, a third positioning structure facing the insulating member is provided on the metal terminal plate, and a fourth positioning structure cooperating with the third positioning structure is provided on the insulating member. On the one hand, through the cooperation of the third positioning structure and the fourth positioning structure, the alignment and positioning of the metal terminal board and the insulating member during the assembly process of the end cover assembly is facilitated, and the assembly efficiency of the end cover assembly is improved; The third positioning structure of the structure is made of metal, which extends into the fourth positioning structure of the insulating member matched with it, which can enhance the strength of the insulating member, thereby strengthening the relationship between the second positioning structure of the insulating member and the first positioning structure of the end cover. The matching strength between them makes the deformation resistance of the end cover assembly in the direction perpendicular to the thickness of the end cover enhanced when the electrode terminal is subjected to external force, which helps reduce the possibility of deformation or misalignment of the seal, thereby reducing the possibility of leakage of the electrode terminal. Probability, improve battery life and safety performance.

In some embodiments, the shape of the first positioning structure on the surface of the end cap is polygonal.

In this embodiment, the first positioning structure may be polygonal on the surface of the end cap, such as a triangle, rectangle, hexagon, etc., so that when only one electrode terminal is provided on the end cap, the polygonal first positioning structure can help resist the contact perpendicular to the end cap. The external force of the electrode terminal is reversed in the thickness direction of the cover, thereby improving the deformation resistance of the end cover assembly and helping to improve the sealing performance of the battery cell.

In some embodiments, the end cap has a plurality of first electrode lead-out holes corresponding to the same electrode of the battery cell, and the shape of the first positioning structure on the surface of the end cap is a circle shape.

In this embodiment, when there are multiple electrode terminals corresponding to the same electrode on the end cover, the first positioning structure can be a circle that is convenient for processing. At this time, multiple circular positioning structures can cooperate with each other to resist the Twisting the external force of the electrode terminal in the thickness direction improves the deformation resistance of the end cover assembly and facilitates production and preparation.

In some embodiments, it is characterized in that the height of the first positioning structure in the thickness direction of the end cover is 1.33-10 times the thickness of the end cover.

In some embodiments, the insulating member is provided with a third protrusion in the second electrode lead-out hole, and the third protrusion is used to press the sealing member along the thickness direction of the end cap.

In this embodiment, the insulating member has a third protrusion in the second electrode lead-out hole, which can press the sealing member in the thickness direction of the end cover, and can prevent the electrode terminal from being pulled by an external force along the thickness direction of the end cover. Displacement in the thickness direction of the cover causes displacement of the seal, further enhancing the sealing performance of the end cover assembly.

In the second aspect, the embodiment of the present application provides a battery cell, including: an electrode assembly; a casing having an opening for accommodating the electrode assembly; the end cap assembly provided in the embodiment of the present application, the end cap assembly covering The opening is used to seal the electrode assembly in the casing.

In some embodiments, the end cap of the end cap assembly is the wall with the largest area of the battery cell.

In a third aspect, the embodiment of the present application provides a battery, including the battery cell provided in the embodiment of the present application.

In a fourth aspect, the embodiment of the present application provides an electric device, including the battery provided in the embodiment of the present application, and the battery is used to provide power for the electric device.

In a fifth aspect, an embodiment of the present application provides a method for preparing a battery cell, including: providing an electrode assembly; providing a housing, the housing having an opening for accommodating the electrode assembly; providing an end cap assembly, the The end cover assembly includes: an end cover, an insulating member and a seal, wherein the end cover is provided with a first electrode lead-out hole, and the end cover is provided with a first positioning structure surrounding the first electrode lead-out hole, the The first positioning structure has a first protrusion toward the interior of the battery cell along the thickness direction of the end cover, and a first groove is formed on a side of the first protrusion facing away from the interior of the battery cell; The insulating member is arranged on the side of the end cover away from the interior of the battery cell, the insulating member has a second electrode drawing hole corresponding to the first electrode drawing hole, and the insulating member is provided with a second electrode drawing hole. Two positioning structures, the second positioning structure has a second protrusion matched with the first groove, the first electrode lead-out hole and the second electrode lead-out hole are used to lead out electrode terminals; the sealing member Used to seal the first electrode lead-out hole, set in the first electrode hole and the second electrode lead-out hole; the first positioning structure and the second positioning structure are used to The direction of cover thickness presses against the sealing member; the opening is covered with the end cover assembly to enclose the electrode assembly in the case.

According to the sixth aspect, there is provided a battery cell manufacturing equipment, comprising: providing a module for providing an electrode assembly; providing a casing, the casing has an opening for accommodating the electrode assembly; providing an end cap assembly, the The end cover assembly includes: an end cover, an insulating member, and a seal; wherein, the end cover is provided with a first electrode lead-out hole, and the end cover is provided with a first positioning structure surrounding the first electrode lead-out hole, so The first positioning structure has a first protrusion toward the interior of the battery cell along the thickness direction of the end cap, and a first groove is formed on a side of the first protrusion facing away from the interior of the battery cell; The insulating member is arranged on the side of the end cap away from the inside of the battery cell, the insulating member has a second electrode drawing hole corresponding to the first electrode drawing hole, and the insulating member is provided with The second positioning structure, the second positioning structure has a second protrusion matching the first groove, the first electrode extraction hole and the second electrode extraction hole are used to extract electrode terminals; the sealing The component is used to seal the first electrode lead-out hole, and is arranged in the first electrode lead-out hole and the second electrode lead-out hole; the first positioning structure and the second positioning structure are used for The direction of the thickness of the end cap presses against the sealing member; an installation module is used to cover the opening with the end cap assembly, so as to seal the electrode assembly in the casing.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the embodiments of the present application. Obviously, the accompanying drawings described below are only some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on the accompanying drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic structural diagram of an electrical device of the present application.

Fig. 2 is a schematic structural diagram of a battery per se.

Fig. 3 is a schematic exploded view of a battery cell of the present application.

Fig. 4 is a schematic structural diagram of an end cover assembly of the present application.

Fig. 5 is a schematic cross-sectional view of an end cover assembly of the present application.

Fig. 6 is a sectional view along the thickness direction of an end cap of the present application.

Fig. 7 is a sectional view along the thickness direction of another end cap of the present application.

Fig. 8 is a schematic cross-sectional view of an end cover assembly of the present application.

9a-9c are schematic diagrams of several end cap assemblies of the present application installed on battery cells.

Fig. 10 is a schematic flowchart of a method for preparing a battery cell of the present application.

FIG. 11 is a schematic structure of a battery cell manufacturing equipment of the present application.

In the drawings, the drawings are not drawn to scale.

Detailed ways

The implementation manner of the present application will be further described in detail below with reference to the drawings and embodiments. The detailed description and drawings of the following embodiments are used to illustrate the principles of the application, but not to limit the scope of the application, that is, the application is not limited to the described embodiments.

In the description of this application, it should be noted that, unless otherwise specified, the meaning of "plurality" is more than two; the terms "upper", "lower", "left", "right", "inner", " The orientation or positional relationship indicated by "outside" and so on are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a reference to this application. Application Restrictions. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

The orientation words appearing in the following description are the directions shown in the figure, and do not limit the specific structure of the application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be interpreted in a broad sense, for example, it can be a fixed connection or a flexible connection. Disassembled connection, or integral connection; it can be directly connected or indirectly connected through an intermediary. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

The term "and/or" in this application is only an association relationship describing associated objects, which means that there may be three relationships, for example, A and/or B, which may mean: A exists alone, A and B exist simultaneously, and A and B exist alone. There are three cases of B. In addition, the character "/" in this application generally indicates that the contextual objects are an "or" relationship.

In the embodiments of the present application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are for illustrative purposes only, and should not constitute any limitation to the application .

"Plurality" in this application refers to two or more (including two).

In the present application, the battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, which are not limited in the embodiments of the present application. The battery cell can be in the shape of a round body, a flat body, a cuboid or other shapes, which is not limited in the embodiment of the present application. Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and pouch battery cells, which are not limited in this embodiment of the present application.

The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack, and the like. Batteries generally include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.

The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell works primarily by moving metal ions between the positive and negative plates. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The current collector without the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer. The current collector coated with the positive electrode active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector coated with the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current is passed without fusing, the number of positive pole tabs is multiple and stacked together, and the number of negative pole tabs is multiple and stacked together. The material of the diaphragm can be PP or PE, etc. In addition, the electrode assembly may be a wound structure or a laminated structure, which is not limited in the embodiment of the present application.

The case of the battery in the embodiment of the present application is used to accommodate a plurality of battery cells, bus components and other components of the battery. In some embodiments, a structure for fixing the battery cells may also be provided in the case. The shape of the box can be determined according to the number of battery cells to be accommodated. In some embodiments, the box may be square, with six walls.

The current-flow component mentioned in this application is used to realize the electrical connection between multiple battery cells, such as parallel connection, series connection or mixed connection. The bus component can realize the electrical connection between the battery cells by connecting the electrode terminals of the battery cells. In some embodiments, the bus member may be fixed to the electrode terminal of the battery cell by welding.

The electrode terminal and the end cap of the battery cell are usually assembled by riveting, and only through the alignment and positioning between the electrode lead-out hole and the electrode terminal, once there is a deviation during assembly, it is easy to cause the seal used to seal the electrode lead-out hole Displacement or deformation occurs; in addition, when the electrode terminal is subjected to an external force perpendicular to the thickness of the end cover, the seal will only contact the thinner end cover in the direction perpendicular to the thickness of the end cover, which will also easily lead to displacement of the seal, seriously Affect the sealing performance and electrochemical performance of the battery cell.

In view of this, an embodiment of the present application provides an end cover assembly, a battery cell, a battery, an electrical device, a method for preparing a battery cell, and a device for preparing a battery cell. Grooves are provided on the end cap, and the insulation member The protrusions are provided to improve the sealing performance of the battery cell, thereby improving the life and chemical performance of the battery.

It should be understood that the above-described components in the battery case should not be construed as limiting the embodiment of the present application, that is, the battery case in the embodiment of the present application may include the above-mentioned components, or may not include the above components.

The technical solutions described in the embodiments of the present application are applicable to various devices using batteries, such as mobile phones, portable devices, notebook computers, battery cars, electric toys, electric tools, vehicles, ships and spacecraft, etc. For example, spacecraft include aircraft , rockets, space shuttles and spaceships, etc.

It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the devices described above, but also applicable to all devices that use batteries. However, for the sake of brevity, the following embodiments take vehicles as examples for illustration.

For example, as shown in Figure 1, it is a schematic structural diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or Extended range cars, etc. A motor 40 , a controller 30 and a battery 10 can be arranged inside the vehicle 1 , and the controller 30 is used to control the battery 10 to supply power to the motor 40 . For example, the battery 10 may be provided at the bottom or front or rear of the vehicle 1 . The battery 10 can be used for power supply of the vehicle 1, for example, the battery 10 can be used as an operating power source of the vehicle 1, for the circuit system of the vehicle 1, for example, for starting, navigating and working power requirements of the vehicle 1 during operation. In another embodiment of the present application, the battery 10 can not only be used as an operating power source for the vehicle 1 , but can also be used as a driving power source for the vehicle 1 , replacing or partially replacing fuel oil or natural gas to provide driving power for the vehicle 1 .

In order to meet different power requirements, the battery 10 may include multiple battery cells. For example, FIG. 2 is a schematic diagram of an exploded structure of a battery 10 according to an embodiment of the present application, and the battery 10 may include a plurality of battery cells 20 . According to different power requirements, the number of battery cells 20 can be set to any value. A plurality of battery cells 20 can be connected in series, in parallel or in parallel to achieve greater capacity or power. Since the number of battery cells 20 included in each battery 10 may be large, for the convenience of installation, the battery cells 20 may be arranged in groups, and each group of battery cells 20 constitutes a battery module. The number of battery cells 20 included in the battery module is not limited and can be set according to requirements. A battery can include a plurality of battery modules, and these battery modules can be connected in series, in parallel or in parallel.

Optionally, the battery 10 may also include other structures. For example, the battery 10 may also include a confluence part, which is used to realize electrical connection between a plurality of battery cells 20 , such as parallel connection, series connection or mixed connection. Specifically, the current-combining component can realize the electrical connection between the battery cells 20 by connecting the electrode terminals of the battery cells 20 . Further, the bus member may be fixed to the electrode terminal of the battery cell 20 by welding. The electric energy of the plurality of battery cells 20 can be further drawn out through the box through the conductive mechanism. Optionally, the conduction means can also belong to the current-collecting part.

The battery 10 may also include a box body (or called a cover body), and the inside of the box body is a hollow structure, and a plurality of battery cells 20 are accommodated in the box body. As shown in Figure 2, the casing can include two parts, referred to here as the first part 111 and the second part 112 (or also can be referred to as the upper case and the lower case), the first part 111 and the second part 112 snap together. The shapes of the first part 111 and the second part 112 may be determined according to the combined shape of a plurality of battery cells 20 , and at least one of the first part 111 and the second part 112 has an opening. For example, only one of the first part 111 and the second part 112 included in the box may be a hollow cuboid with an opening, while the other is in the shape of a plate to cover the opening. For example, as shown in Figure 2, here the second part 112 is a hollow cuboid and only one face is an open face, and the first part 111 is a plate-shaped example, and the first part 111 is covered at the opening of the second part 112 to form A box with a closed chamber that can be used to accommodate a plurality of battery cells 20 .

Optionally, the first part 111 and the second part 112 included in the box in the embodiment of the present application may also have other shapes, for example, both the first part 111 and the second part 112 may be hollow cuboids with only one surface It is an open surface, the opening of the first part 111 and the opening of the second part 112 are arranged oppositely, and the first part 111 and the second part 112 are interlocked to form a box with a closed cavity. A plurality of battery cells 20 are combined in parallel, in series or in parallel and placed in the box formed by fastening the first component 111 and the second component 112 .

For the convenience of description, the box body 11 shown in FIG. 2 is mainly used as an example for description below, but the embodiment of the present application is not limited thereto.

As shown in FIG. 3 , it is an exploded view of a battery cell 20 of the present application. The battery cell 20 accommodated in the box usually includes an end cap assembly 21, a casing 22 and an electrode assembly 23. The casing 22 has an opening. For accommodating the electrode assembly 23 , the end cap assembly 21 covers the opening of the casing 22 to seal the electrode assembly 23 in the casing.

In addition, the end cap assembly 21 is also electrically connected to the electrode assembly 23 , so that the electrode assembly 23 can transmit electric energy to the outside of the casing 22 through the electrode terminal 210 of the end cap assembly 21 , and be combined or assembled with other battery cells 20 .

Optionally, the end cover assembly 21 is provided with an electrode lead-out hole 201 , and the electrode terminal 210 is sealed and installed in the electrode lead-out hole 201 through a seal 211 such that the electrode terminal 210 and the end cover 212 are riveted.

It should be understood that the end cover 212 refers to the wall where the electrode terminal 210 is located among all the walls of the battery cell 20 .

Optionally, the end cover 212 is the wall of the battery cell 20 with the largest area.

The embodiment of the present application provides an end cap assembly, which can effectively improve the sealing performance of the battery cell, thereby improving the battery life and electrochemical performance.

As shown in FIG. 4 and FIG. 5 , which are respectively a schematic structural view and a cross-sectional view of an end cap assembly of the present application, the end cap assembly 21 includes: an end cap 212 , an insulating member 213 and a sealing member 211 .

Wherein, the end cover 212 is provided with a first electrode lead-out hole 201 and a first positioning structure 2011 arranged around the electrode lead-out hole 201 , and the first positioning structure 2011 has a first A protrusion 2011a, and a first groove 2011b is formed on a side of the first protrusion 2011a away from the interior of the battery cell 20 .

The insulating member 213 is disposed on the side of the end cap 212 facing away from the inside of the battery cell 20 , the insulating member 213 has a second electrode lead-out hole 202 corresponding to the first electrode lead-out hole 201 , and the insulating member 213 is provided with a second positioning structure 2012 , The second positioning structure 2012 has a second protrusion 2012a matched with the first groove 2011b, and the first electrode lead-out hole 201 and the second electrode lead-out hole 202 are used to lead out the electrode terminal 210 .

The sealing member 211 is used to seal the first electrode lead-out hole 201, and is arranged in the first electrode lead-out hole 201 and the second electrode lead-out hole 202; the first positioning structure 2011 and the second positioning structure 2012 are used for The direction of the pressure seal 211.

That is to say, during the assembly process of the battery cell 20, the electrode terminal 210 needs to pass through the end cap 212 and the insulating member 213 that cooperate with each other, and the sealing member 211 is located in the first electrode lead-out hole 201 and the second electrode lead-out hole 202, That is, the end cover 212 and the insulating member 213 can jointly press the sealing member 211 in the direction perpendicular to the thickness of the end cover 212 through the first positioning structure 2011 and the second positioning structure 2012. The positioning structure 2011 and the second positioning structure 2012, on the one hand, help the accurate positioning of the end cover assembly 21 during the assembly process, reduce the probability of offset during assembly of the end cover assembly 21, and on the other hand, can increase the size of the seal 211 is pressed against the area perpendicular to the thickness direction of the end cap 212. When the electrode terminal 210 is twisted by an external force perpendicular to the thickness direction of the end cap 212, the first positioning structure 2011 and the second positioning structure 2012 jointly bear the pressure transmitted by the seal 211. Compared with the case where the sealing member 211 is only pressed by the end cover 212, the force bearing area of the sealing member 211 in this direction is increased, and the possibility of deformation or misalignment is reduced, thereby reducing the leakage of the electrode terminal 210. The probability of gas leakage can effectively improve the lifespan and electrochemical performance of the battery 10 .

Optionally, the first positioning structure 2011 includes a plurality of first protrusions 2011a. Exemplarily, the multiple first protrusions 2011 a of the first positioning structure 2011 are multiple concentric circles with different radii on the surface of the end cap 212 , and the centers of the concentric circles are also the centers of the first electrode lead-out holes 201 . For another example, the plurality of first protrusions 2011 a of the first positioning structure 2011 are formed on the surface of the end cap 212 as a plurality of geometric figures with the same geometric center, which is also the center of the first electrode lead-out hole 201 .

It should be understood that when the surface of the first positioning structure 2011 on the end cover 212 facing the inside of the battery cell 20 includes a plurality of first protrusions 2011a, that is, the surface facing the outside of the battery cell 20 includes a plurality of corresponding first concaves. When the groove 2011b is used, the corresponding second positioning structure 2012 includes a plurality of second protrusions 2012a on the surface facing the battery cell 20 .

Preferably, the thickness of the bottom wall of the first groove 2011 b is equal to the thickness of the end cover 212 .

Specifically, as shown in FIG. 6 , it is a cross-sectional view of the end cover 212 along the thickness direction. The end cap 212 has a thickness h1, the bottom wall of the first groove 2011b has a thickness h2 and h1=h2, and the depth of the first groove 2011b along the thickness direction is H.

In this embodiment, h1=h2 is designed, that is, the first groove 2011b can be directly processed by stamping the end cap 212, without complicated preparation process, the process is simple and easy to produce, which helps to improve the production of the end cap assembly 21 efficiency.

Optionally, the thickness of the bottom wall of the first groove 2011b is smaller than the thickness of the end cover 212 . Specifically, as shown in FIG. 7 , it is another cross-sectional view of the end cover 212 along the thickness direction.

In this embodiment, h1>h2 is designed, that is, the first groove 2011b can be directly processed by cutting the end cap 212, without complicated preparation process, the process is simple and easy to produce, which is helpful to improve the production of the end cap assembly 21 efficiency.

Optionally, as shown in FIG. 4 or FIG. 8 , the end cover assembly 21 further includes: a metal terminal plate 214 , the metal terminal plate 214 is disposed on the side of the insulating member 213 away from the end cover 212 for connecting with the electrode terminal 210 . A third positioning structure 2013 is provided on the side of the metal terminal plate 214 facing the insulating member 213 , and a fourth positioning structure 2014 matching the third positioning structure 2013 is provided on the side of the insulating member 213 facing away from the end cap 212 .

Optionally, as shown in FIG. 8, the third positioning structure 2013 is a raised structure 2013a. That is, the third positioning structure 2013 is a raised structure on the section along the thickness direction of the end cover 212 , and correspondingly, the fourth positioning structure 2014 is also a groove structure 2014 a on the section along the thickness direction of the end cover 212 .

Optionally, the third positioning structure 1031 is a spherical or table-shaped raised structure. That is, the third positioning structure 1031 is a spherical or table-shaped raised structure on the section along the thickness direction of the end cover 212, and correspondingly, the fourth positioning structure 1041 is also a spherical or table-shaped groove structure on the section along the thickness direction of the end cover 212. .

It should be understood that the third positioning structure 1031 may include only one table-shaped or spherical raised structure 2013a, or may include multiple table-shaped or spherical raised structures 2013a.

Optionally, the table-shaped or spherical raised structure 2013 a corresponds to the second protrusion 2012 a of the second positioning structure 2012 one-to-one. That is, one table-shaped or spherical raised structure 2013a only extends into one second protrusion 2012a, and the number of the third positioning structure 2013's table-shaped or spherical raised structure 2013a is equal to the number of the second positioning structure 2012's second protrusions 2012a . If the second positioning structure 2012 has only one second protrusion 2012a, then the third positioning structure 2013 is only provided with a table-shaped or spherical raised structure 2013a, and a second positioning structure 2012 only relies on a table-shaped or spherical raised structure 2013a to increase mechanical strength ; If the second positioning structure 2012 has a plurality of second protrusions 2012a, the third positioning structure 2013 is provided with a plurality of table-shaped or spherical raised structures 2013a corresponding to the plurality of second protrusions 2012a, one second positioning structure 2012 relies on a plurality of table-shaped or spherical raised structures 2013a acting together to increase mechanical strength.

Optionally, a plurality of the table-shaped or spherical raised structures 2013 a correspond to the second protrusion 2012 a of the second positioning structure 2012 . That is, a plurality of table-shaped or spherical protruding structures 2013a extend into a second protrusion 2012a to jointly strengthen the second positioning structure 2012 of the insulating member 213, and the number of table-shaped or spherical protruding structures 2013a of the third positioning structure 2013 is greater than that of the second protrusion 2012a. The number of the second protrusions 2012a of the positioning structure 2012. If the second positioning structure 2012 has only one second protrusion 2012a, then a plurality of table-shaped or spherical raised structures 2013a of the third positioning structure 2013 all extend into the second protrusion 2012a; if the second positioning structure 2012 has multiple first Two protrusions 2012a, each of the second protrusions 2012a is provided with a plurality of table-shaped or spherical raised structures 2013a extending therein, and the second positioning structure 2012 relies on a plurality of table-shaped or spherical raised structures 2013a to work together to increase the mechanical strength .

In this embodiment, on the one hand, the third positioning structure 2013 and the fourth positioning structure 2014 that cooperate with each other facilitate the alignment and positioning of the metal terminal plate 214 and the insulating member 213 during the assembly process of the end cover assembly 21, and improve the assembly of the end cover assembly 21 Efficiency; on the other hand, the third positioning structure 2013 with the protruding structure 2013a is made of metal material, which extends into the fourth positioning structure 2014 of the insulating member 213 that cooperates with it, so that the strength of the insulating member 213 can be enhanced, thereby strengthening the insulating member 213 The matching strength between the second positioning structure 2012 of the end cover 212 and the first positioning structure 2011 of the end cover 212 makes the electrode terminal 210 receive an external force parallel to the direction of the surface of the end cover 212, the end cover assembly 21 is perpendicular to the thickness direction of the end cover 212 The anti-deformation ability on the surface is enhanced, which helps to reduce the possibility of deformation or misalignment of the sealing member 211 , thereby reducing the probability of liquid leakage and air leakage of the electrode terminal 210 , and improving the lifespan and electrochemical performance of the battery 10 .

As shown in FIGS. 9 a - 9 c , it is a schematic diagram of installing the end cover assembly 21 with the first positioning structure 2011 of different shapes on the battery cell 20 .

Optionally, the shape of the first positioning structure 2011 on the surface of the end cover 212 is a polygon. Such as triangles, rectangles, hexagons, etc.

In this embodiment, the first positioning structure 2011 is an angular polygon on the surface of the end cover 212, so that when only one electrode terminal 210 is provided on the end cover 212, the polygonal first positioning structure 2011 can help resist the thickness perpendicular to the thickness of the end cover 212. The direction of the external force of the electrode terminal 210 is reversed, thereby improving the deformation resistance of the end cover assembly 21 and helping to improve the sealing performance of the battery cell 20 . It should be understood that the direction perpendicular to the thickness of the end cap 212 is the direction parallel to the surface of the end cap 212 .

As shown in FIG. 3 , it shows a schematic diagram of installing the end cap assembly 21 with a plurality of electrode extraction holes 201 on the battery cell 20 .

Optionally, the end cap 212 has a plurality of first electrode lead-out holes 201 corresponding to the same electrode of the battery cell 20 , and the shape of the first positioning structure 2011 on the surface of the end cap 212 is circular.

In this embodiment, the battery cell 20 has a plurality of electrode terminals 210 corresponding to the same electrode, and has a plurality of first electrode lead-out holes 201 corresponding to the same electrode on the end cover 212. At this time, the first positioning structure 2011 can be convenient Processed circular, multiple circular first positioning structures 2011 can cooperate with each other, resist the external force of twisting the electrode terminal 210 perpendicular to the thickness direction of the end cover 212, improve the deformation resistance of the end cover assembly 21, and facilitate production and preparation .

Optionally, the height of the first positioning structure 2011 in the thickness direction of the end cover 212 is 1.33-10 times the thickness of the end cover 212 .

Specifically, as shown in FIG. 6 or FIG. 7, the first positioning structure 2011 has a first protrusion 2011a on the side of the end cover 212 facing the inside of the battery cell 20 along the thickness direction of the end cover 212, and at the same time, on the side away from the battery cell A first groove 2011b is formed on one side of the body 20, and the depth H of the first groove 2011b is the height of the first positioning structure 2011 along the thickness direction of the end cover 212, 1.33*h1≤H≤10*h1.

For example, the thickness h1 of the end cap 212 is 0.3mm, and the depth H of the first groove 2011b is 0.4mm; for another example, the thickness of the end cap 212 is h1=0.1mm, and the depth H of the first groove 2011b is 1mm.

In this embodiment, by setting the depth range of the first groove 2011b, it avoids the problem that the mechanical strength of the thinner end cap 212 at the first electrode lead-out hole 2011 is not enough to meet the assembly requirements due to the excessive depth of the first groove 2011b It also avoids the problem that the first positioning structure 2011 has an insignificant positioning effect and is difficult to process due to the too small depth of the first groove 2011b.

Optionally, as shown in FIG. 8 , the insulating member 213 is provided with a third protrusion 2013 b inside the second electrode lead-out hole 202 , and the third protrusion 2013 b is used to press the sealing member 211 along the thickness direction of the end cap 212 .

In this embodiment, the insulating member 213 has a third protrusion 2013b in the second electrode lead-out hole 201, which can press the sealing member 211 in the thickness direction of the end cap 212, thereby preventing the sealing member 211 from being pulled when the electrode terminal 210 is pulled by an external force. Displacement occurs in the thickness direction of the end cap 212 to cause displacement of the sealing element 211 , which further enhances the sealing performance of the end cap assembly 21 .

The end cap assembly 21, the battery cell 10, the battery 10, and the electrical device 1 of the embodiment of the present application are described above, and the method and device for preparing the battery cell 10 of the embodiment of the present application will be described below. Part of it can be referred to the foregoing embodiments.

As shown in FIG. 10, the embodiment of the present application also provides a method for preparing a battery cell 10, including:

S1001, providing an electrode assembly 23;

S1002, providing a casing 22, the casing 22 has an opening for accommodating the electrode assembly 21;

S1003, providing an end cover assembly 21, the end cover assembly 21 comprising: an end cover 212, an insulating member 213 and a seal 211, wherein the end cover 212 is provided with a first electrode lead-out hole 201, and the end cover 212 is provided with a The first positioning structure 2011 of the first electrode lead-out hole 201, the first positioning structure 2011 has a first protrusion 2011a toward the inside of the battery cell 20 along the thickness direction of the end cover 212, and the first protrusion 2011a faces away from the battery cell 20. One side inside the battery cell 20 is formed with a first groove 2011b; the insulating member 213 is disposed on the side of the end cover 212 away from the inside of the battery cell 20, and the insulating member 213 has a The second electrode lead-out hole 202 corresponding to the hole 201, the insulating member 213 is provided with a second positioning structure 2012, the second positioning structure 2012 has a second protrusion 2012a matched with the first groove 2011b, the first electrode lead-out The hole 201 and the second electrode lead-out hole 202 are used to lead out the electrode terminal 210; the seal 211 is used to seal the first electrode lead-out hole 201, and is arranged in the first electrode hole 201 and the second electrode lead-out hole 202; The first positioning structure 2011 and the second positioning structure 2012 are used to press the sealing member 211 in a direction perpendicular to the thickness of the end cover 212;

S1004, cover the opening with the end cap assembly 21 to seal the electrode assembly 23 in the casing 22 .

As shown in FIG. 11 , the embodiment of the present application also provides a preparation device 1100 for a battery cell 20, including:

Provide a module 1101 for providing an electrode assembly 23; provide a casing 22, which has an opening for accommodating the electrode assembly 21; provide an end cap assembly 21, which includes: an end cap 212, an insulating member 213 and a sealing member 211; wherein, the end cover 212 is provided with a first electrode extraction hole 201, and the end cover 212 is provided with a first positioning structure 2011 surrounding the first electrode extraction hole 201, and the first positioning structure 2011 has along the The thickness direction of the end cover 212 faces the first protrusion 2011a inside the battery cell 20, and a first groove 2011b is formed on the side of the first protrusion 2011a away from the inside of the battery cell 20; the insulating member 213 is disposed on On the side of the end cover 212 away from the interior of the battery cell 20 , the insulating member 213 has a second electrode lead-out hole 202 corresponding to the first electrode lead-out hole 201 , and the insulating member 213 is provided with a second positioning structure 2012 , the second positioning structure 2012 has a second protrusion 2012a matched with the first groove 2011b, the first electrode lead-out hole 201 and the second electrode lead-out hole 202 are used to lead out the electrode terminal 210; the seal 211 is used To seal the first electrode lead-out hole 201, it is arranged in the first electrode hole 201 and the second electrode lead-out hole 202; the first positioning structure 2011 and the second positioning structure 2012 are used to The direction of thickness presses against the seal 211;

The installation module 1102 is used for covering the opening with the end cap assembly 21 to seal the electrode assembly 23 in the casing 22 .

It should be noted that, on the premise of no conflict, each embodiment described in this application and/or the technical features in each embodiment can be combined with each other arbitrarily, and the technical solution obtained after the combination should also fall within the protection scope of this application .

In the several embodiments provided in this application, it should be understood that the disclosed systems and devices can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices or units, and may also be electrical, mechanical or other forms of connection.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment of the present application.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

An end cover assembly of a battery cell, characterized in that it comprises:

An end cover, the end cover is provided with a first electrode lead-out hole, the end cover is provided with a first positioning structure surrounding the first electrode lead-out hole, and the first positioning structure has a direction along the thickness direction of the end cover a first protrusion inside the battery cell, and a first groove is formed on the side of the first protrusion facing away from the inside of the battery cell;

The insulating member is arranged on the side of the end cover away from the inside of the battery cell, the insulating member has a second electrode drawing hole corresponding to the first electrode drawing hole, and the insulating member is provided with a second electrode drawing hole. a positioning structure, the second positioning structure has a second protrusion matching the first groove, and the first electrode extraction hole and the second electrode extraction hole are used to extract electrode terminals;

A seal, used to seal the first electrode lead-out hole, is arranged in the first electrode lead-out hole and the second electrode lead-out hole;

Wherein, the first positioning structure and the second positioning structure are used to press the sealing member in a direction perpendicular to the thickness of the end cover.
The end cap assembly according to claim 1, wherein the thickness of the bottom wall of the first groove is equal to the thickness of the end cap.
The end cap assembly according to claim 1, characterized in that, the thickness of the bottom wall of the first groove is smaller than the thickness of the end cap.
The end cover assembly according to any one of claims 1-3, wherein the end cover assembly further comprises:

A metal terminal plate is disposed on a side of the insulating member away from the end cap, the metal terminal plate is used to connect to the electrode terminals, and a side of the metal terminal plate facing the insulating member is provided with third positioning structure;

Wherein, a fourth positioning structure cooperating with the third positioning structure is provided on a side of the insulating member away from the end cap.
The end cap assembly according to claim 4, wherein the third positioning structure is a raised structure.
The end cover assembly according to any one of claims 1-5, wherein the shape of the first positioning structure on the surface of the end cover is polygonal.
The end cap assembly according to any one of claims 1-6, wherein the end cap has a plurality of first electrode lead-out holes corresponding to the same electrode of the battery cell, and the first The shape of a positioning structure on the surface of the end cap is circular.
The end cover assembly according to any one of claims 1-7, wherein the height of the first positioning structure in the thickness direction of the end cover is 1.33-10 of the thickness of the end cover times.
The end cover assembly according to any one of claims 1-8, wherein the insulating member is provided with a third protrusion in the second electrode lead-out hole, and the third protrusion is used for The thickness direction of the end cover is pressed against the sealing element.
A battery cell, characterized in that it comprises:

electrode assembly;

a housing having an opening for receiving the electrode assembly;

The end cap assembly according to any one of claims 1-9, wherein the end cap assembly covers the opening to seal the electrode assembly in the casing.
The battery cell according to claim 10, wherein the end cap of the end cap assembly is the wall with the largest area of the battery cell.
A battery, characterized by comprising the battery cell according to claim 10 or 11.
An electrical device, characterized by comprising the battery according to claim 12, the battery being used for powering the electrical device.
A method for preparing a battery cell, comprising:

Provide electrode assemblies;

providing a case having an opening for receiving the electrode assembly;

An end cover assembly is provided, and the end cover assembly includes: an end cover, an insulating member, and a seal, wherein the end cover is provided with a first electrode extraction hole, and the end cover is provided with a hole surrounding the first electrode extraction hole. A first positioning structure, the first positioning structure has a first protrusion toward the interior of the battery cell along the thickness direction of the end cover, and the first protrusion is formed on a side away from the interior of the battery cell There is a first groove; the insulating member is disposed on the side of the end cap away from the interior of the battery cell, the insulating member has a second electrode lead-out hole corresponding to the first electrode lead-out hole, The insulating member is provided with a second positioning structure, the second positioning structure has a second protrusion matched with the first groove, and the first electrode extraction hole and the second electrode extraction hole are used to extract Electrode terminals; the seal is used to seal the first electrode lead-out hole, and is arranged in the first electrode hole and the second electrode lead-out hole; the first positioning structure and the second positioning structure are used pressing against the seal in a direction perpendicular to the thickness of the end cap;

Covering the opening with the end cap assembly to seal the electrode assembly in the casing.
A preparation device for a battery cell, characterized in that it comprises:

providing a module for providing an electrode assembly; providing a housing having an opening for receiving the electrode assembly; providing an end cap assembly comprising: an end cap, an insulating member, and a seal; wherein , the end cover is provided with a first electrode lead-out hole, the end cover is provided with a first positioning structure surrounding the first electrode lead-out hole, and the first positioning structure has a direction along the thickness direction of the end cover toward the A first protrusion inside the battery cell, and a first groove is formed on the side of the first protrusion facing away from the inside of the battery cell; the insulating member is arranged on the side of the end cover away from the battery cell One side inside the body, the insulating member has a second electrode lead-out hole corresponding to the first electrode lead-out hole, the insulating member is provided with a second positioning structure, and the second positioning structure has a A second protrusion matched with a groove, the first electrode lead-out hole and the second electrode lead-out hole are used to lead out electrode terminals; the sealing member is used to seal the first electrode lead-out hole, and is arranged on the In the first electrode hole and the second electrode lead-out hole; the first positioning structure and the second positioning structure are used to press the sealing member in a direction perpendicular to the thickness of the end cap;

An installation module is used for covering the opening with the end cap assembly to seal the electrode assembly in the casing.