CN217788704U

CN217788704U - Battery cell, battery and consumer

Info

Publication number: CN217788704U
Application number: CN202221290772.XU
Authority: CN
Inventors: 陈龙; 陈新祥; 林蹬华; 黄守君; 郑于炼; 王鹏; 金海族
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-03-18
Filing date: 2022-05-27
Publication date: 2022-11-11
Anticipated expiration: 2032-05-27
Also published as: WO2023173429A1

Abstract

The embodiment of the application provides a single battery (20), a manufacturing method (300) and manufacturing equipment (400) of the single battery, a battery (10) and electric equipment (1) so as to improve the performance of a pressure relief mechanism (23) on the single battery (20). The battery cell (20) includes: a housing (21); an electrode assembly (22) housed in the case (21); an end cap for covering the housing (21); and the pressure relief mechanism (23) is arranged on a first wall (213) of the shell (21), the thickness of the first wall (213) is larger than that of other walls except the first wall (213) on the shell (21), and the pressure relief mechanism (23) is used for relieving the internal pressure of the battery cell (20) when the internal pressure of the battery cell (20) exceeds a threshold value.

Description

Battery cell, battery and consumer

The present application claims priority of PCT patent application No. PCT/CN2022/081791 entitled "battery cell and manufacturing method and manufacturing apparatus thereof, battery, and power consumption apparatus" filed at 18/3/2022 by the chinese patent office, which is incorporated herein by reference in its entirety.

Technical Field

The application relates to the technical field of batteries, in particular to a battery cell, a manufacturing method and manufacturing equipment thereof, a battery and electric equipment.

Background

The lithium ion battery has the advantages of small volume, high energy density, long cycle service life, long storage time and the like, and is widely applied to the fields of electronic equipment, electric vehicles, electric toys and the like, for example, mobile phones, notebook computers, electric bicycles, electric automobiles, electric airplanes, electric ships, electric toy automobiles, electric toy ships, electric toy airplanes, electric tools and the like.

With the continuous development of lithium ion battery technology, higher requirements are also put forward on the safety performance of the lithium ion battery. The pressure relief mechanism on the lithium ion battery has an important influence on the safety performance of the lithium ion battery. For example, when the lithium ion battery is short-circuited or overcharged, thermal runaway inside the lithium ion battery may occur, and the internal air pressure may suddenly rise. Therefore, the design of the pressure relief mechanism is extremely important.

SUMMERY OF THE UTILITY MODEL

The application provides a battery monomer, a manufacturing method and manufacturing equipment of the battery monomer, a battery and electric equipment, so that the performance of a pressure relief mechanism on the battery monomer is improved.

In a first aspect, a battery cell is provided, including: a housing; an electrode assembly housed within the case; the end cover is used for covering the shell; and the pressure relief mechanism is arranged on the first wall of the shell, the thickness of the first wall is greater than that of other walls except the first wall of the shell, and the pressure relief mechanism is used for relieving the internal pressure of the single battery when the internal pressure of the single battery exceeds a threshold value.

The utility model provides a be provided with pressure relief mechanism on the first wall of free casing of battery, because the thickness of first wall is thicker than other walls, not only improved pressure relief mechanism's welding reliability, and make first wall non-deformable, thereby make pressure relief mechanism receive the influence of the creep that internal pressure arouses less, and then make pressure relief mechanism's burst pressure receive the influence of this creep less, make pressure relief mechanism can release this internal pressure effectively when this internal pressure is greater than the threshold value. At the same time, thinning the thickness of the other walls also reduces the manufacturing cost of the housing 21.

In one implementation, the thickness of the first wall is greater than or equal to 0.2mm and less than or equal to 3mm.

The large thickness of the first wall brings about additional costs, and the small thickness easily makes the burst pressure of the pressure relief mechanism affected by creep due to the internal pressure of the battery cell, and for this reason, the thickness thereof should be set within a suitable range, for example, between 0.2mm and 3mm.

In one implementation, the thickness of the other wall of the housing except the first wall is greater than or equal to 0.2mm and less than or equal to 1mm.

The large thickness of the other walls of the housing than the first wall brings about additional costs, and the small thickness does not ensure the structural stability of the battery cell, and for this reason, the thickness of the other walls should be set within a suitable range, for example, between 0.2mm and 1mm.

In one implementation, the first wall is a bottom wall of the housing, and the bottom wall is a wall of the battery cell that is farthest from a passenger.

In this embodiment, the first wall provided with the pressure relief mechanism is the housing bottom wall, that is, the pressure relief mechanism is downward, so that, when the battery is placed under the seat of the vehicle, the pressure relief mechanism can be away from the passenger, so that the internal pressure of the battery cell is released downward, reducing the risk of injury to the passenger.

In one implementation, the thickness of the effective position of the pressure relief mechanism is greater than or equal to 0.01mm and less than or equal to 0.5mm.

When the thickness of the pressure relief mechanism is small, the assembly difficulty is increased, and the pressure relief mechanism is easy to damage in the assembly process. The thickness of the pressure relief mechanism should be set in consideration of the internal pressure of the battery cell, and generally should be matched with the threshold value, so that the pressure relief mechanism can be opened preferentially when the internal pressure of the battery cell exceeds the threshold value, for example, the thickness of the pressure relief mechanism is set to be between 0.01mm and 0.5mm.

In one implementation mode, the pressure relief mechanism is provided with a notch, and the thickness of the pressure relief mechanism is the residual thickness of the notch.

In the embodiment, the notch is arranged on the pressure relief mechanism, when the internal pressure of the battery cell exceeds the threshold value, the pressure relief mechanism is opened preferentially through the notch, the manufacturing process is simple, and the pressure relief effect is excellent. At this time, the thickness of the pressure relief mechanism is the residual thickness of the nick.

In one implementation, the battery cell is a cuboid, and the first wall is parallel to a length direction of the battery cell.

In this embodiment, the battery monomer can be the cuboid, because the free casing of battery is longer, is unfavorable for the free internal pressure's of battery release, consequently, with pressure relief mechanism setting and edge on the free parallel first wall of length direction of battery, can form the effective route that can supply this internal pressure to release through this pressure relief mechanism when the free internal pressure of battery surpasses the threshold value, solved the difficult pressure release's of long battery monomer problem.

In one implementation, the housing has a first opening and a second opening opposite to each other along a length direction of the battery cell, and the end caps include a first end cap and a second end cap, and the first end cap and the second end cap are respectively used for covering the first opening and the second opening.

Because the casing of the battery monomer is provided with the first opening and the second opening along the length direction of the battery monomer, and the battery monomer also comprises the first end cover and the second end cover which are respectively used for covering the first opening and the second opening, the electrode component can be conveniently placed into the casing, and the assembly process of the battery monomer is simplified.

In a second aspect, a battery is provided, which includes the battery cell described in the first aspect or any implementation manner of the first aspect, and the battery cell is used for providing electric energy.

In a third aspect, an electric device is provided, which includes the battery cell described in the first aspect or any implementation manner of the first aspect, where the battery cell is used to provide electric energy.

In a fourth aspect, a method of manufacturing a battery cell is provided, including: providing a shell and an electrode assembly, wherein a first wall of the shell is provided with a pressure relief mechanism, the thickness of the first wall is greater than that of other walls except the first wall of the shell, and the pressure relief mechanism is used for relieving the internal pressure of the battery cell when the internal pressure of the battery cell exceeds a threshold value; the electrode assembly is housed within the case.

In a fifth aspect, there is provided a battery cell manufacturing apparatus including: the battery pack comprises a providing module, a battery module and a battery module, wherein the providing module is used for providing a shell and an electrode assembly, a first wall of the shell is provided with a pressure relief mechanism, the thickness of the first wall is greater than that of other walls except the first wall of the shell, and the pressure relief mechanism is used for relieving the internal pressure of the battery monomer when the internal pressure of the battery monomer exceeds a threshold value; an assembly module for housing the electrode assembly within the case.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a battery according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a battery cell according to an embodiment of the present application;

fig. 4 is a schematic view of a first wall of the housing of the battery cell shown in fig. 3;

fig. 5 isbase:Sub>A sectional view of the battery cell shown in fig. 4 taken along the directionbase:Sub>A-base:Sub>A;

fig. 6 is an enlarged view of a partial region B of the battery cell shown in fig. 5;

fig. 7 is a schematic structural diagram of a battery cell according to an embodiment of the present application;

fig. 8 is a schematic diagram of a vent path of the internal pressure of the battery cell;

fig. 9 is an exploded schematic view of a battery cell;

FIG. 10 is a schematic view of the structure of an electrode assembly in accordance with an embodiment of the present application;

fig. 11 is a schematic view of the structure of another electrode assembly according to an embodiment of the present application;

FIG. 12 is a schematic view of a further electrode assembly according to an embodiment of the present application;

fig. 13 is a schematic flow chart of a method of manufacturing a battery cell of an embodiment of the present application;

fig. 14 is a schematic block diagram of a manufacturing apparatus of a battery cell of an embodiment of the present application.

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

Detailed Description

Embodiments of the present application will be described in further detail below with reference to the drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the application and are not intended to limit the scope of the application, i.e., the application is not limited to the described embodiments.

In the description of the present application, it is to be noted that, unless otherwise specified, "a plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like, indicate an orientation or positional relationship that is merely for convenience in describing the application and to simplify the description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. "vertical" is not strictly vertical, but is within the tolerance of the error. "parallel" is not strictly parallel but is within the tolerance of the error.

The directional terms used in the following description are intended to refer to directions shown in the drawings, and are not intended to limit the specific structure of the present application. In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present application can be understood as appropriate by one of ordinary skill in the art.

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

In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiments of the present application. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application. The battery cells are generally divided into three types in an encapsulation manner: the cylindrical battery monomer, the square battery monomer and the soft package battery monomer are also not limited in the embodiment of the application.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The box can avoid liquid or other foreign matters to influence the charge or discharge of battery cells.

The battery monomer comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive electrode plate, a negative electrode plate and a separation film. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece includes anodal mass flow body and anodal active substance layer, and anodal active substance layer coats in anodal mass flow body's surface, and the anodal mass flow body protrusion in the anodal mass flow body that has coated anodal active substance layer of uncoated anodal active substance layer, and the anodal mass flow body that does not coat anodal active substance layer is as anodal utmost point ear. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece includes negative pole mass flow body and negative pole active substance layer, and the negative pole active substance layer coats in the surface of negative pole mass flow body, and the negative pole mass flow body protrusion in the negative pole mass flow body of coating the negative pole active substance layer not coating the negative pole active substance layer, and the negative pole mass flow body of not coating the negative pole active substance layer is as negative pole utmost point ear. The material of the negative electrode collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, the number of the positive electrode tabs is multiple and the positive electrode tabs are stacked together, and the number of the negative electrode tabs is multiple and the negative electrode tabs are stacked together. The material of the isolation film may be polypropylene (PP) or Polyethylene (PE). In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The single battery can be provided with a pressure relief mechanism, and the pressure relief mechanism is used for releasing the internal pressure of the single battery when the internal pressure of the single battery reaches a threshold value. When the internal pressure of the battery cell reaches a threshold value, a path through which the internal pressure can be released can be formed by the pressure release mechanism. The performance of the pressure relief mechanism directly affects the safety of the battery cell.

Generally, the respective walls of the case of the battery cell are equally thick for convenience of manufacture. If the thickness of the shell is smaller, the bursting pressure of the pressure relief mechanism is easily influenced by creep deformation caused by the internal pressure of the single battery, so that the pressure relief performance of the pressure relief mechanism is influenced; if the thickness of the housing is large, additional cost is added.

For this reason, this application embodiment provides a battery monomer, battery monomer includes electrode assembly, electrode assembly holds in the casing, be provided with pressure relief mechanism on the first wall of this casing, it is thicker than other walls through the thickness that sets up this first wall, can improve pressure relief mechanism's welding reliability, and make first wall non-deformable, thereby it is less to make pressure relief mechanism receive the influence of the creep that internal pressure arouses, and then make pressure relief mechanism's burst pressure receive the influence of this creep less, make pressure relief mechanism can discharge this internal pressure effectively when this internal pressure is greater than the threshold value. At the same time, thinning the thickness of the other walls also reduces the manufacturing cost of the housing 21.

The technical scheme described in the embodiment of the application is suitable for various electric equipment using batteries.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like; spacecraft include aircraft, rockets, space shuttles, and spacecraft, among others; the electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not specifically limit the above-mentioned electric devices.

For convenience of explanation, the following embodiments will be described by taking an electric device as an example of a vehicle.

For example, as shown in fig. 1, which is a schematic structural diagram of a vehicle 1 according to an embodiment of the present disclosure, the vehicle 1 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or an extended range automobile. The vehicle 1 may be provided with a motor 40, a controller 30 and a battery 10, wherein the controller 30 is used for controlling the battery 10 to supply power to the motor 40. For example, the battery 10 may be provided at the bottom or the head or tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, for example, the battery 10 may be used as an operation power supply of the vehicle 1 for a circuit system of the vehicle 1, for example, for power demand for operation at the start, navigation, and running of the vehicle 1. In another embodiment of the present application, the battery 10 may be used not only as an operation power source of the vehicle 1 but also as a driving power source of the vehicle 1 instead of or in part of fuel or natural gas to provide driving power to the vehicle 1. Battery 10 may also be referred to as a battery pack.

In order to meet different power requirements, the battery 10 may include a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in series-parallel, where series-parallel refers to a mixture of series connection and parallel connection.

For example, fig. 2 shows a schematic structural diagram of a battery 10 according to an embodiment of the present application, and the battery 10 may include a plurality of battery cells 20. The battery 10 may further include a case 11, the inside of the case 11 is a hollow structure, and the plurality of battery cells 20 are accommodated in the case 11. Fig. 2 shows a possible implementation of the box body 11 of the embodiment of the present application, and as shown in fig. 2, the box body 11 may include two parts, which are referred to as a first box body part 111 and a second box body part 112, respectively, and the first box body part 111 and the second box body part 112 are buckled together. The shape of the first and second casing portions 111 and 112 may be determined according to the shape of the plurality of battery cells 20 combined, and at least one of the first and second casing portions 111 and 112 may have one opening. For example, as shown in fig. 2, each of the first casing portion 111 and the second casing portion 112 may be a hollow rectangular parallelepiped, and only one surface of each of the first casing portion 111 and the second casing portion 112 is an open surface, the opening of the first casing portion 111 and the opening of the second casing portion 112 are disposed to face each other, and the first casing portion 111 and the second casing portion 112 are engaged with each other to form the casing 11 having a closed chamber.

For another example, unlike the case shown in fig. 2, only one of the first and second casing portions 111 and 112 may be a hollow rectangular parallelepiped having an opening, and the other may be plate-shaped to cover the opening. For example, here, the second case portion 112 is a hollow rectangular parallelepiped, and only one surface is an opening surface, and the first case portion 111 is a plate shape, then the first case portion 111 covers the opening of the second case portion 112 to form the case 11 having a closed chamber, which can be used to accommodate a plurality of battery cells 20. The plurality of battery cells 20 are connected in parallel, in series, or in series-parallel combination, and then placed in the case 11 formed by fastening the first case portion 111 and the second case portion 112.

In some embodiments, battery 10 may also include other structures, which are not described in detail herein. For example, the battery 10 may further include a bus member for achieving electrical connection between the plurality of battery cells 20, such as parallel connection, series connection, or series-parallel connection. Specifically, the bus member may achieve electrical connection between the battery cells 20 by connecting electrode terminals of the battery cells 20. Further, the bus bar member may be fixed to the electrode terminals of the battery cells 20 by welding. The electric energy of the plurality of battery cells 20 can be further led out through the case 11 by the conductive mechanism.

The number of cells 20 in the battery 10 may be set to any number according to different power requirements. A plurality of battery cells 20 may be connected in series, parallel, or series-parallel to achieve greater capacity or power. Since the number of the battery cells 20 included in each battery 10 may be large, the battery cells 20 are arranged in groups for convenience of installation, and each group of the battery cells 20 constitutes the battery module 200. The number of the battery cells 20 included in the battery module 200 is not limited and may be set as desired. That is, the plurality of battery cells 20 may be directly assembled into the battery 10, or may be assembled into a battery module, and then the battery module is assembled into the battery 10.

Fig. 3 to 6 show a battery cell 20 of an embodiment of the present application. Fig. 4 is a schematic view of the first wall 213 of the housing 21 of the battery cell 20 shown in fig. 3. Fig. 5 isbase:Sub>A sectional view of the battery cell 20 shown in fig. 4 taken along thebase:Sub>A-base:Sub>A direction. Fig. 6 is an enlarged view of a partial region B of the battery cell 20 shown in fig. 5.

As shown in fig. 3 to 6, the battery cell 20 of the embodiment of the present application includes a case 21, an electrode assembly 22 (not shown in fig. 3 to 6), and a pressure relief mechanism 23. Wherein the electrode assembly 22 is accommodated in the case 21. The pressure relief mechanism 23 is provided on the first wall 213 of the case 21, the thickness of the first wall 213 is greater than the thickness of the other walls of the case 21 except the first wall 213, and the pressure relief mechanism 23 is configured to relieve the internal pressure of the battery cell 20 when the internal pressure of the battery cell 20 exceeds a threshold value.

With the battery cell 20 of the embodiment of the present application, the thickness of the first wall 213 of the case 21 is greater than the thickness of the other walls of the case 21 except for the first wall 213. For example, as shown in fig. 5, the thickness of the first wall 213 is larger than the thickness of the second wall 214, the third wall 215, and the fourth wall 216 on the housing 21 except for the first wall 213.

Because the thickness of the first wall 213 for installing the pressure relief mechanism 23 on the casing 21 is thicker than the other wall thicknesses except the first wall 213 on the casing 21, the thicker first wall 213 makes the welding reliability of the pressure relief mechanism 23 higher, and makes the first wall 213 not easily deform, thereby making the influence of the creep deformation caused by the internal pressure on the pressure relief mechanism 23 smaller, further making the influence of the creep deformation on the burst pressure of the pressure relief mechanism 23 smaller, making the pressure relief mechanism 23 able to effectively release the internal pressure when the internal pressure is greater than the threshold value. Meanwhile, thinning the thicknesses of the other walls also reduces the manufacturing cost of the housing 21.

The large thickness of the first wall 213 causes additional cost, and the small thickness easily causes the burst pressure of the pressure relief mechanism to be affected by creep due to the internal pressure of the battery cell, and for this reason, the thickness thereof should be set within a proper range. For example, in one implementation, the thickness of the first wall is greater than or equal to 0.2mm and less than or equal to 3mm.

The thickness of the other walls of the case 21 except the first wall 213 is large, which causes additional cost, and the small thickness does not ensure the structural stability of the battery cell 20, and for this reason, the thickness of the other walls should be set within a proper range. For example, in one implementation, the thickness of the walls of the housing 21 other than the first wall 213 is greater than or equal to 0.2mm and less than or equal to 1mm.

In one implementation, the thickness of the pressure relief mechanism 23 is less than the thickness of the housing 21, the thickness of the pressure relief mechanism 23 being the thickness at the active location of the pressure relief mechanism 23, which is the location on the pressure relief mechanism 23 that is preferentially open. In this way, by setting the thickness of the pressure relief mechanism 23 to be smaller than the thickness of the case 21, when the internal pressure of the battery cell 20 is greater than the threshold value, the pressure relief mechanism 23 can be opened preferentially, thereby providing an effective pressure relief path.

For example, as shown in fig. 5 and 6, the thickness of the first wall 213 of the housing 21 is greater than the thickness of the other walls of the housing 21 except for the first wall 213, and the thickness of the pressure relief mechanism 23 is less than the thickness of the other walls of the housing 21 except for the first wall 213. Assuming that the thicknesses of the pressure relief mechanism 23, the first wall 213, the second wall 214, the third wall 215, and the fourth wall 216 are T0, T1, T2, T3, T4, respectively, the relationship between the thickness of the case 22 and the thickness of the pressure relief mechanism 23 satisfies T0 < T2= T3= T4 < T1. Here, when the first wall 213 has a plurality of thicknesses, T1 is a size of the maximum wall thickness of the first wall 213. Accordingly, assuming that the maximum pressures that the pressure relief mechanism 23, the first wall 213, the second wall 214, the third wall 215, and the fourth wall 216 can withstand are P0, P1, P2, P3, P4, respectively, P0 < P2= P3= P4 < P1.

It can be seen that when the thickness of the case 22 and the thickness of the pressure relief mechanism 23 satisfy the above relationship, on one hand, since the thickness of the pressure relief mechanism 23 is smaller than the thickness of other walls of the case 21, when the internal pressure of the battery cell 20 is greater than the threshold value, the pressure relief mechanism 23 can be opened preferentially, so as to provide an effective pressure relief path; on the other hand, increasing the thickness of the first wall 213 can improve the welding reliability of the pressure relief mechanism 23 on the first wall 213, and make the first wall 213 less susceptible to deformation, so that the influence of creep caused by the internal pressure on the pressure relief mechanism 23 is small, and further the influence of the creep on the burst pressure of the pressure relief mechanism 23 is small, so that the pressure relief mechanism 23 can effectively release the internal pressure when the internal pressure is greater than the threshold value. Meanwhile, thinning the thicknesses of the other walls also reduces the manufacturing cost of the housing 21.

Here, the thickness of the relief mechanism 23 is a thickness at an effective position of the relief mechanism 23, and the effective position is a position on the relief mechanism 23 that is preferentially opened. For example, in one implementation, as shown in fig. 6, a notch 231 is provided on the pressure relief mechanism 23, and the thickness of the pressure relief mechanism 23 is the residual thickness of the notch 231. When the internal pressure of the battery cell 20 exceeds the threshold value, the pressure relief mechanism 23 is preferentially opened through the notch 231, the manufacturing process is simple, and a superior pressure relief effect is achieved. At this time, the position of the notch 213 is the effective position of the pressure relief mechanism 23, and the thickness of the pressure relief mechanism 23 is the residual thickness of the notch 213.

The battery cell 20 further includes end caps for covering the housing 21, and the number of the end caps may be one or more. The above description is made by taking the case that the battery cell 20 includes the housing 21 and the two end caps as an example, in this case, the housing 21 includes four walls, and the thickness of the first wall 213 is greater than the thickness of the other three walls. It should be understood that when the battery cell 20 includes a housing 21 and an end cap, the thickness of the first wall 213, where the pressure relief mechanism 23 is located, may be greater than the thickness of the other four walls, since the housing 21 includes five walls.

The embodiment of the present application does not limit the form of the pressure relief mechanism 23. The pressure relief mechanism 23 may be a component independent from the first wall 213, for example, an opening is formed on the first wall 213, the pressure relief mechanism 23 covers the opening, and a notch 231 is formed on the pressure relief mechanism 23; alternatively, the pressure relief mechanism 23 may be a notch 231 formed directly on the first wall 213.

In order to avoid the influence of the assembly process on the pressure relief performance of the pressure relief mechanism 23, in one implementation, the pressure relief mechanism 23 is recessed in the first wall 213 of the housing 21, that is, buried in the first wall 213, so that the influence of collision and the like on the pressure relief mechanism 23 is avoided in the assembly process of the pressure relief mechanism 23 and the housing 21.

The pressure relief mechanism 23 may not be opened preferentially when the thickness is large, and the difficulty of assembly is increased when the thickness of the pressure relief mechanism 23 is small, and the pressure relief mechanism is easily damaged in the assembly process. The thickness of the pressure relief mechanism 23 should be set in consideration of the internal pressure of the battery cell 20, and generally should match the threshold value described above so that the pressure relief mechanism can be opened preferentially when the internal pressure of the battery cell exceeds the threshold value. For example, in one implementation, the thickness at the active location of the pressure relief mechanism 23 is greater than or equal to 0.01mm and less than or equal to 0.5mm.

In one implementation, as shown in fig. 7, the first wall 213 of the housing 21 is a bottom wall of the housing 21, and the bottom wall is a wall of the battery cell 20 farthest from the passenger. That is, the pressure relief mechanism 23 is directed downward such that when the battery 10 is placed under the seat of the vehicle 1, the pressure relief mechanism 23 can be distanced away from the occupant such that the internal pressure of the battery cell 20 is vented downward, reducing the risk of injury to the occupant.

The present embodiment does not limit the number of electrode assemblies 22 in the battery cell 20. The battery cell 20 may include one electrode assembly 22, or the battery cell 20 may include a plurality of electrode assemblies 22. Hereinafter, the description will be made taking the case where the battery cell 20 includes a plurality of electrode assemblies 22 as an example. For example, the battery cell 20 may include two electrode assemblies 22, and in this case, the two electrode assemblies 22 may be arranged in the length direction X of the battery cell 20; for another example, the battery cell 20 may include a plurality of sets of electrode assemblies 22, and the plurality of sets of electrode assemblies 22 may be arranged along the thickness direction Y of the battery cell 20, wherein each set of electrode assemblies 22 includes two electrode assemblies 22 arranged along the length direction X of the battery cell 20; for another example, the battery cell 20 may include more than two electrode assemblies 22, and the electrode assemblies 22 are arranged along the length direction X of the battery cell 20.

Hereinafter, the description of the battery cell 20 according to the embodiment of the present application is continued by taking an example in which the battery cell 20 includes two electrode assemblies 22, and the two electrode assemblies 22 are arranged in the length direction X of the battery cell 20.

The shape of the battery cell 20 is not limited in the embodiment of the present application, and for example, the battery cell 20 may be a rectangular parallelepiped including the electrode assembly 22 arranged in the length direction X.

When the battery cell 20 is a rectangular parallelepiped, since the case 21 of the battery cell 20 is long, it is not favorable for the internal pressure of the battery cell 20 to be discharged. Thus, in one implementation, the battery cell 20 is a rectangular parallelepiped, and the first wall 213 is parallel to the length direction X of the battery cell 20. Like this, when free internal pressure of battery surpassed the threshold value, can form the effective path that can supply this internal pressure to release through this pressure relief mechanism, solved the difficult pressure release's of long battery monomer problem.

When the battery cell 20 is out of control due to heat, the internal pressure of the battery cell exceeds the threshold, and the pressure relief mechanism 23 can be actuated when the internal pressure of the battery cell reaches the threshold, so that a path for releasing the internal pressure is formed, the internal pressure is released, the explosion risk of the battery cell 20 is reduced, and the safety of the battery cell 20 is improved.

In this embodiment, for example, as shown in fig. 8 and 9, the pressure relief mechanism 23 may be provided on the first wall 213 at a position opposite to the region between the first electrode assembly 221 and the second electrode assembly 222 arranged in the length direction X. In this way, when the internal pressure of the battery cell 20 reaches the threshold value, the path formed by the pressure relief mechanism 213 through which the internal pressure can be released is short, which facilitates the release of the pressure. Wherein, the arrows in fig. 8 indicate the path of pressure relief, when the internal pressure of the battery cell 20 is greater than the threshold value, the pressure relief mechanism 23 is activated and releases the internal pressure to the outside of the battery cell 20 along the direction of the arrows, so as to achieve rapid pressure relief. The two square-shaped dashed boxes in fig. 8 represent the first electrode assembly 221 and the second electrode assembly 222, respectively.

The above-mentioned "activation" means that the pressure relief mechanism 23 is operated so that the internal pressure of the battery cell 20 is relieved. The action of the pressure relief mechanism 23 includes, but is not limited to, at least a portion of the pressure relief mechanism 23 rupturing, melting, splitting, etc. When the pressure relief mechanism 23 is activated, the internal pressure of the battery cell 20 may be released from the activated portion of the pressure relief mechanism 23, and may carry high-temperature and high-pressure excreta, such as electrolyte, fragments of dissolved or split positive and negative electrode plates or separators, high-temperature and high-pressure gas generated by reaction, or flame.

In one implementation, adjacent two electrode assemblies 22 are electrically isolated. For example, as shown in fig. 9, an insulation sheet 24 is disposed between the first electrode assembly 221 and the second electrode assembly 222 to reduce the possibility of contact between the first electrode assembly 221 and the second electrode assembly 222, reduce the risk of short circuit, and improve the safety of the battery cell 20.

For example, as shown in fig. 9 for the first electrode assembly 221, the tab 2212 of the first electrode assembly 221 is disposed at a first end surface 223 of the first electrode assembly 221, the first end surface 223 being perpendicular to the length direction X and facing the outside of the battery cell 20. The tabs 2212 include a first tab 2212a and a second tab 2212b, wherein one of the first tab 2212a and the second tab 2212b is a positive tab and the other is a negative tab. Similarly, with respect to the second electrode assembly 222, the tabs of the second electrode assembly 222 are disposed at the end surfaces of the second electrode assembly 222 perpendicular to the length direction X and directed to the outside of the battery cell 20, and are not illustrated here for the sake of brevity.

As can be seen, the connection of the electrode terminals 214 of the battery cell 20 is facilitated by respectively locating the tabs of the adjacent two electrode assemblies 22 at both end surfaces in the length direction X of the battery cell 20.

In one implementation, as shown in fig. 9, the housing 21 has a first opening 2211 and a second opening 2212 opposite to each other along the length direction X of the battery cell 20, and the battery cell 20 further includes a first end cover 2121 and a second end cover 2122, and the first end cover 2121 and the second end cover 2122 are respectively used for covering the first opening 2211 and the second opening 2212.

Since the case 21 of the battery cell 20 has the first and

second openings

2211 and 2212 along the length direction X of the battery cell 20, and the battery cell 20 further includes the first and

second end caps

2121 and 2122 for covering the first and

second openings

2211 and 2212, respectively, the insertion of the electrode assembly 22 into the case is facilitated, and the assembly process of the battery cell 20 is simplified.

In one implementation, the two adjacent electrode assemblies 22 arranged along the length direction X of the battery cell 20 are arranged in an insulating manner; the first end cover 2121 is provided with a positive electrode terminal and a negative electrode terminal of the battery cell 20, and is used for leading out electric energy of one electrode assembly 22 in the two adjacent electrode assemblies 22; the second end cover 2122 is provided with a positive electrode terminal and a negative electrode terminal of the battery cell 20 for drawing out electric energy of the other electrode assembly 22 of the two adjacent electrode assemblies 22.

Since the positive electrode terminal and the negative electrode terminal of the battery cell 20 are disposed on the first end cap 2121 and the second end cap 2122, that is, a set of electrode terminals is disposed on each of the first end cap 2121 and the second end cap 2122, and the adjacent electrode assemblies 2 disposed along the length direction X of the battery cell 20 are insulated from each other, the two sets of electrode terminals can respectively conduct the currents of the different electrode assemblies 22, so as to reduce the current flowing between the electrode assemblies 22, reduce the heat generated by the battery cell, and improve the charge and discharge performance of the battery cell 20.

For example, as shown in fig. 9, the first end cover 2121 is provided with a set of electrode terminals 214 of the battery cell 20, including a first electrode terminal 214a and a second electrode terminal 214b; similarly, a set of electrode terminals 214 of the battery cell 20, including a first electrode terminal 214a and a second electrode terminal 214b, are also disposed on the second end cover 2122, and the electrode terminals 214 on the second end cover 2122 are not shown in fig. 9 for simplicity. One of the first electrode terminal 214a and the second electrode terminal 214b is a positive electrode terminal, and the other is a negative electrode terminal. The electrode terminal 214 of the first end cap 2121 and the electrode terminal 214 of the second end cap 2122 are capable of conducting current of the first electrode assembly 221 and the second electrode assembly 222, respectively, so as to reduce current flowing between the first electrode assembly 221 and the second electrode assembly 222, reduce heat generated by the battery cell 20, and improve charge and discharge performance of the battery cell 20.

In one implementation, as shown in fig. 9, case 21 further includes separator 25 covering first wall 213 of case 21 to isolate the surface of electrode assembly 22 from case 21.

In one implementation, as shown in FIG. 9, the first wall 213 of the housing 21 is a wall of the housing 21 that has a smaller area. Since the first electrode assembly 221 and the second electrode assembly 222 expand and press the separator 25 covering the first wall 23 during charging, the separator 25 is deformed, thereby causing deformation of the pressure relief mechanism 23. The smaller the area, the smaller the expansion force received, and the smaller the degree of deformation. By providing the pressure relief mechanism 23 on the first wall 213 with a smaller area on the case 21, the deformation of the pressure relief mechanism 23 can be reduced, the risk of fatigue damage to the pressure relief mechanism 23 can be reduced, and the safety of the battery cell 20 can be improved.

The present embodiment does not limit the type of electrode assembly 22. For example, as shown in fig. 10, the electrode assembly 22 includes a first pole piece 224 and a second pole piece 225, and the first pole piece 224 and the second pole piece 225 are wound around a winding axis that is parallel to the length direction X of the battery cell 20; for another example, as shown in fig. 11, the electrode assembly 22 includes a plurality of first pole pieces 224 and a plurality of second pole pieces 225, the plurality of first pole pieces 224 and the plurality of second pole pieces 225 are alternately stacked in a second direction Y, which is perpendicular to the length direction X of the battery cell 20; for another example, as shown in fig. 12, the electrode assembly 22 includes a first pole piece 224 and a plurality of second pole pieces 225, the first pole piece 224 includes a plurality of lamination segments 224a and a plurality of bending segments 224b, the bending segments 224b are used for connecting two adjacent lamination segments 224a, the plurality of second pole pieces 225 and the plurality of lamination segments 224a are alternately laminated in a second direction Y, and the second direction Y is perpendicular to the length direction X of the electrode assembly 22.

Since the winding axes of the first and

second pole pieces

224 and 225 of the electrode assembly 22 are parallel to the longitudinal direction X of the battery cell 20, or the lamination direction of the first and

second pole pieces

224 and 225 of the electrode assembly 22 is perpendicular to the longitudinal direction X thereof, most of the gas generated by the electrode assembly 22 is discharged along the end of the first pole piece in the longitudinal direction X and the end of the second pole piece in the longitudinal direction X, and a gap through which the gas passes may be formed between the end of the first pole piece 224 in the longitudinal direction X and the end of the second pole piece 225 in the longitudinal direction X. The pressure relief mechanism 23 is located on the first wall 213 at a position opposite to a region between the first electrode assembly 221 and the second electrode assembly 222 arranged in the length direction X, and when the internal pressure of the battery cell 20 exceeds a threshold value, gas can pass through the gap and act on the pressure relief mechanism 23 to actuate the pressure relief mechanism 23, thereby relieving the internal pressure.

In which, one of the first pole piece 224 and the second pole piece 225 is a positive pole piece, and the other is a negative pole piece, and fig. 10 and 11 take the second pole piece 225 as the negative pole piece, and the first pole piece 224 as the positive pole piece as an example; fig. 12 illustrates the second pole piece 225 as a positive pole piece, and the first pole piece 224 as a negative pole piece.

In one implementation, as shown in fig. 10-12, electrode assembly 22 further includes a separator 226 for insulating first pole piece 224 from second pole piece 225.

In one implementation, two tabs of the electrode assembly 22 are disposed at a first end surface 223 of the electrode assembly 22, the first end surface 223 is perpendicular to the length direction X of the battery cell 20, and the tabs of two adjacent electrode assemblies 22 face opposite directions and both face the outside of the battery cell 20.

In one possible specific implementation manner of the battery cell 20, the pressure relief mechanism 23 on the battery cell 20 is disposed on the first wall 213 of the housing 21, and the first wall 213 is a bottom wall of the housing 21. The relief mechanism 23 is provided with a notch 231. The thickness of the first wall is greater than the thickness of the other walls of the housing except the first wall, and the residual thickness of the score 231 is less than the thickness of the housing 21. The pressure relief mechanism 23 is located on the first wall 213 at a position opposite to a region between two adjacent electrode assemblies 22 arranged in the length direction X of the battery cell 20.

Based on the above description, it can be seen that, the pressure relief mechanism 23 is disposed on the first wall 213 of the housing 21 on the battery cell 20 in the embodiment of the present application, because the thickness of the pressure relief mechanism 23 is smaller than that of the housing 21, and the thickness of the first wall 213 on the housing 21 for disposing the pressure relief mechanism 23 is thicker than other walls, while it is ensured that the pressure relief mechanism 23 can be preferentially opened to form an effective path for releasing internal pressure, the welding reliability of the pressure relief mechanism 23 is also improved, the pressure relief performance of the battery cell 20 is improved, the safety of the battery cell 20 is ensured, and the influence of creep caused by the internal pressure of the battery cell 20 on the first wall 213 in the pressure relief process is small, and the stability of the housing 21 is ensured.

Having described the battery cell 20, the battery 10, and the electric device 1 of the embodiment of the present application, a manufacturing method and a manufacturing apparatus of the battery cell 20 of the embodiment of the present application will be described below, and portions not described in detail may be referred to the foregoing embodiments.

Fig. 10 shows a schematic flow chart of a method 300 of manufacturing the battery cell 20 of the embodiment of the present application. As shown in fig. 13, the method 300 includes: providing a case 21 and an electrode assembly 22, wherein a pressure relief mechanism 23 is arranged on a first wall 213 of the case 21, the thickness of the first wall 213 is greater than that of the other walls of the case 21 except the first wall 213, and the pressure relief mechanism 23 is used for relieving the internal pressure of the battery cell 20 when the internal pressure of the battery cell 20 exceeds a threshold value; electrode assembly 22 is accommodated in case 21.

Fig. 11 shows a schematic block diagram of a manufacturing apparatus 400 of the battery cell 20 of the embodiment of the present application. As shown in fig. 14, the apparatus 400 includes: a providing module 410, configured to provide the case 21 and the electrode assembly 22, wherein a pressure relief mechanism 23 is disposed on a first wall 213 of the case 21, a thickness of the first wall 213 is greater than a thickness of other walls of the case 21 except the first wall 213, and the pressure relief mechanism 23 is configured to relieve an internal pressure of the battery cell 20 when the internal pressure of the battery cell 20 exceeds a threshold value; and an assembly module 420 for accommodating the electrode assembly 22 in the case 21.

The structure of the battery cell 20 manufactured by the manufacturing method 300 and the manufacturing apparatus 400 can be referred to the battery cell 20 in the above-mentioned various implementation manners, and for brevity, the description is omitted here.

It should be noted that, in the case of no conflict, the methods in the above-mentioned respective implementation modes may be combined with each other.

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, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims

1. A battery cell (20), comprising:

a housing (21);

an electrode assembly (22) housed in the case (21);

an end cap for covering the housing (21); and (c) a second step of,

the pressure relief mechanism (23) is arranged on a first wall (213) of the shell (21), the thickness of the first wall (213) is larger than the thickness of other walls except the first wall (213) on the shell (21), and the pressure relief mechanism (23) is used for relieving the internal pressure of the battery cell (20) when the internal pressure of the battery cell (20) exceeds a threshold value.

2. The battery cell (20) of claim 1, wherein the first wall (213) has a thickness greater than or equal to 0.2mm and less than or equal to 3mm.

3. The battery cell (20) according to claim 1 or 2, wherein the thickness of the wall of the housing (21) other than the first wall (213) is greater than or equal to 0.2mm and less than or equal to 1mm.

4. The battery cell (20) of claim 1 or 2, wherein the first wall (213) is a bottom wall of the housing (21), the bottom wall being the wall of the battery cell furthest from a passenger.

5. The battery cell (20) according to claim 1 or 2, wherein the thickness of the pressure relief mechanism (23) at the effective position is greater than or equal to 0.01mm and less than or equal to 0.5mm.

6. The battery cell (20) according to claim 5, wherein a notch (231) is arranged on the pressure relief mechanism (23), and the thickness of the pressure relief mechanism (23) is the residual thickness of the notch (231).

7. The battery cell (20) of claim 1 or 2, wherein the battery cell (20) is a cuboid, the first wall (213) being parallel to a length direction (X) of the battery cell (20).

8. The battery cell (20) of claim 1 or 2, wherein the housing (21) has first and second openings (2211, 2212) opposite in a length direction (X) of the battery cell (20), the end caps comprising first and second end caps (2121, 2122), the first and second end caps (2121, 2122) for covering the first and second openings (2211, 2212), respectively.

9. A battery (10) comprising: the battery cell (20) according to any one of claims 1 to 8, the battery cell (20) being for providing electrical energy.

10. An electrical consumer (10) comprising: the battery cell (20) of any of claims 1 to 8, the battery cell (20) being for providing electrical energy.