CN216250985U

CN216250985U - Battery cell, battery and consumer

Info

Publication number: CN216250985U
Application number: CN202122368653.3U
Authority: CN
Inventors: 周文林; 李全坤; 王鹏; 金海族
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-09-28
Filing date: 2021-09-28
Publication date: 2022-04-08
Anticipated expiration: 2031-09-28

Abstract

The embodiment of the application provides a battery cell, a battery and electric equipment. The battery cell includes: an electrode assembly including a main body portion and tabs; and the shell is used for accommodating the electrode assembly, the first wall of the shell comprises a first body and a mounting body connected to the first body, a pressure relief mechanism is arranged on the mounting body and used for actuating to relieve the pressure when the internal pressure or temperature of the battery cell reaches a threshold value, in the thickness direction of the first wall, at least one part of the mounting body protrudes out of the surface of the first body facing the electrode assembly along the direction facing the electrode assembly, and the minimum distance between the pressure relief mechanism and the main body part is smaller than the minimum distance between the first body and the main body part. The application provides a battery monomer, battery and consumer can strengthen the security of battery.

Description

Battery cell, battery and consumer

Technical Field

The application relates to the technical field of batteries, in particular to a battery monomer, a battery and electric equipment.

Background

Energy conservation and emission reduction are the key points of sustainable development of the automobile industry. Under such circumstances, electric vehicles are an important component of sustainable development of the automobile industry due to their energy saving and environmental protection advantages. In the case of electric vehicles, battery technology is an important factor in the development thereof.

In addition to improving the performance of batteries, safety issues are also a considerable problem in the development of battery technology. If the safety problem of the battery cannot be guaranteed, the battery cannot be used. Therefore, how to enhance the safety of the battery is a technical problem to be solved urgently in the battery technology.

SUMMERY OF THE UTILITY MODEL

The application provides a battery monomer, battery and consumer, can strengthen the security of battery.

In a first aspect, a battery cell is provided, including: an electrode assembly including a main body portion and tabs; the first wall of the shell comprises a first body and a mounting body connected to the first body, wherein the mounting body is provided with a pressure relief mechanism, and the pressure relief mechanism is used for actuating to relieve the pressure when the internal pressure or the temperature of the battery cell reaches a threshold value; wherein, in the thickness direction of the first wall, at least a part of the mounting body protrudes from the surface of the first body facing the electrode assembly in the direction facing the electrode assembly, and the minimum distance between the pressure relief mechanism and the main body part is smaller than the minimum distance between the first body and the main body part.

Therefore, the battery monomer of this application embodiment, pressure release mechanism is closer to electrode subassembly for other regions of the first body of first wall, like this, pressure release mechanism receives the probability reduction of external force impact, even place first wall towards the bottom of the box of battery, bear battery monomer through first wall promptly, pressure release mechanism is closer to the free inside of battery for other regions of first wall, also be far away from the bottom of the box of battery more, this can reduce the probability that pressure release mechanism is directly impacted by the external force from the bottom half, just also avoid the pressure release mechanism inefficacy that external force impact leads to as far as possible.

In some embodiments, at least a portion of the mounting body has a thickness greater than a thickness of the first body.

Like this, even pressure release mechanism place region receives exogenic action, because pressure release mechanism place region thickness is great, then intensity increases, and the destroyed probability of this pressure release mechanism reduces, can further improve this pressure release mechanism's security.

In some embodiments, the mounting body includes an installation portion and a connection portion, the installation portion is used for installing the pressure relief mechanism, the thickness of the installation portion is greater than that of the connection portion, and the connection portion is used for connecting the installation portion and the first body.

If the first wall is deformed under the action of external force, the connecting part connected with the first body can be used as a main stress area around the pressure relief area, and the pressure relief mechanism is arranged at one end, close to the electrode assembly, of the mounting part with larger thickness.

In some embodiments, the mounting body is provided with a pressure relief hole, and the pressure relief mechanism covers the pressure relief hole and is activated to relieve the pressure through the pressure relief hole when the internal pressure or temperature of the battery cell reaches a threshold value.

In some embodiments, the mounting body has a first recess that is recessed away from the electrode assembly from a surface of the mounting body facing the electrode assembly, at least a portion of the pressure relief mechanism being received in the first recess.

In some embodiments, the bottom surface of the first recess is closer to the electrode assembly than the surface of the first body facing the electrode assembly, so as to ensure that the thickness of the region of the mounting part where the pressure relief structure is disposed is greater than the thickness of the first body, thereby ensuring the strength of the mounting part and improving the safety of the pressure relief mechanism.

In some embodiments, the pressure relief hole is provided in a bottom surface of the first recess.

In some embodiments, the battery cell further includes: and the protection plate is arranged on one side of the pressure relief hole, which is deviated from the electrode assembly, and is used for protecting the pressure relief mechanism.

In some embodiments, a side of the mounting body facing away from the electrode assembly has a protrusion surrounding the pressure relief hole, the protrusion protruding from a surface of the mounting body facing away from the electrode assembly in a direction facing away from the electrode assembly, and the protective sheet is disposed on a surface of the protrusion facing away from the electrode assembly for easy processing and installation.

In some embodiments, the mounting body has a second concave portion that is concave from a surface of the mounting body facing away from the electrode assembly toward a direction facing the electrode assembly, the pressure relief hole penetrates a bottom surface of the first concave portion and a bottom surface of the second concave portion, and the convex portion is located at the bottom surface of the second concave portion.

In some embodiments, the height of the protrusion is less than the depth of the second recess.

That is, the surface of the protective sheet facing away from the electrode assembly does not exceed the outer surface of the first body, and does not interfere with the mounting of other components on the end of the cap plate facing away from the electrode assembly, facilitating processing and mounting.

In some embodiments, the mounting body is a unitary structure with the first body.

For example, the mounting body may be formed by integral stamping, which may simplify the manufacturing process.

In some embodiments, the mounting body and the first body may also be independent components, so that the mounting body may be more flexibly configured, thereby improving the performance of the mounting body.

In some embodiments, the mounting body includes an installation portion and a connection portion, the installation portion is used for installing the pressure relief mechanism, the connection portion is used for connecting the installation portion and the first body, and the thickness of the connection portion gradually increases from the first body to the installation portion.

Connecting portion have an inclined plane from the installation department to first body promptly, when first wall received the exogenic action, this inclined plane can the even atress, avoids certain regional concentrated atress and arouses ground deformation and fracture, improves the security performance.

In some embodiments, the first wall further includes a second body connected to the first body, the first body protrudes away from the electrode assembly relative to the second body, and forms a recessed region on a same side facing the electrode assembly, the recessed region being configured to receive at least a portion of the mounting body and the pressure relief mechanism.

In some embodiments, the electrode assembly includes a body portion and a tab; the first wall is provided with an electrode terminal for electrical connection with the tab, and the recessed area is also for receiving at least a portion of the tab.

The depressed area can reduce the occupied space of the pressure relief mechanism and the lug in the shell, so that the space of the main body part of the electrode assembly is larger, and the energy density of a battery monomer can be improved.

In some embodiments, in the thickness direction, a minimum distance between a surface of the mounting body facing the electrode assembly and the main body portion is a first distance, and a minimum distance between a surface of the second body facing the electrode assembly and the main body portion is a second distance, the second distance being less than or equal to the first distance.

The surface of the pressure relief mechanism facing the electrode assembly does not exceed the inner surface of the second body, so that the pressure relief mechanism does not affect the space of the main body part of the electrode assembly, more space is reserved for the main body part of the electrode assembly, and the energy density of the battery monomer is favorably improved.

In some embodiments, the housing comprises: a case having an opening, the electrode assembly being received in the case; the cover plate is used for covering the opening, and the first wall is the cover plate.

In a second aspect, there is provided a battery comprising: the battery cell of the first aspect; the box is used for accommodating a plurality of battery cells.

In a third aspect, an electrical device is provided, comprising: the battery of the second aspect, for providing electrical energy to a powered device.

In some embodiments, the powered device is a vehicle, a watercraft, or a spacecraft.

In a fourth aspect, there is provided a method of making a battery cell, comprising: providing an electrode assembly; providing a cover plate and a shell, wherein the electrode assembly is contained in the shell, the cover plate comprises a first body and a mounting body connected to the first body, and a pressure relief mechanism is arranged on the mounting body and is used for actuating to relieve the pressure when the internal pressure or temperature of the battery cell reaches a threshold value; at least one part of the mounting body protrudes from the surface of the first body facing the electrode assembly in the thickness direction of the cover plate, and the minimum distance between the pressure relief mechanism and the electrode assembly is smaller than the minimum distance between the first body and the electrode assembly.

In a fifth aspect, there is provided an apparatus for preparing a battery cell, comprising means for performing the method of the fourth aspect.

Drawings

FIG. 1 is a schematic illustration of a vehicle according to an embodiment of the present disclosure;

fig. 2 is an exploded view of a battery according to an embodiment of the present disclosure;

fig. 3 is a schematic structural view of a battery module according to an embodiment of the present disclosure;

fig. 4 is a schematic diagram of a battery cell according to an embodiment of the present disclosure;

fig. 5 is an exploded view of a battery cell according to an embodiment of the present disclosure;

FIG. 6 is an exploded view of a cover plate with a pressure relief mechanism according to an embodiment of the present disclosure;

FIG. 7 is a top view of a cover plate with a pressure relief mechanism according to an embodiment of the present disclosure;

FIG. 8 is a cross-sectional view of a cover plate with a pressure relief mechanism as disclosed in one embodiment of the present application;

FIG. 9 is an enlarged, fragmentary view of a cross-sectional view of a cover plate provided with a pressure relief mechanism as disclosed in an embodiment of the present application;

FIG. 10 is a cross-sectional view of a mounting portion according to an embodiment of the present disclosure;

FIG. 11 is an exploded view of another cover plate with a pressure relief mechanism according to an embodiment of the present disclosure;

FIG. 12 is a top view of another cover plate with a pressure relief mechanism disclosed in an embodiment of the present application;

FIG. 13 is a cross-sectional view of another cover plate with a pressure relief mechanism disclosed in an embodiment of the present application;

FIG. 14 is an enlarged, fragmentary view of a cross-sectional view of another cover plate provided with a pressure relief mechanism as disclosed in an embodiment of the present application;

fig. 15 is a schematic flow chart of a method of making a cell disclosed in an embodiment of the present application;

fig. 16 is a schematic block diagram of an apparatus for manufacturing a battery cell according to an embodiment of the present disclosure.

In the drawings, the drawings are not necessarily 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 within the tolerance of the error.

The following description is given with the directional terms as they are used in the drawings and 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 exemplary 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 charging or discharging of battery monomer.

The battery monomer comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive pole piece, a negative pole piece and an isolating membrane. 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 current 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 development of battery technology needs to consider various design factors, such as energy density, cycle life, discharge capacity, charge and discharge rate, and other performance parameters, and also needs to consider the safety of the battery.

For the battery, the main safety hazard comes from the charging and discharging processes, and in order to improve the safety performance of the battery, a pressure relief mechanism is generally arranged on the battery cell. The pressure relief mechanism refers to an element or a component that is actuated to relieve the internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a predetermined threshold. The predetermined threshold may be adjusted according to design requirements. The predetermined threshold may depend on the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolyte and the separator in the battery cell. The pressure relief mechanism may employ, for example, a pressure-sensitive or temperature-sensitive element or component, i.e., the pressure relief mechanism is actuated when the internal pressure or temperature of the battery cell reaches a predetermined threshold, thereby forming a channel through which the internal pressure or temperature may be vented.

The term "activate" as used herein refers to the action of the pressure relief mechanism, such that the internal pressure and temperature of the battery cell are released. The actions generated by the pressure relief mechanism may include, but are not limited to: at least a portion of the pressure relief mechanism ruptures, is torn or melts, etc. After the pressure relief mechanism is actuated, high-temperature and high-pressure substances inside the battery cells are discharged outwards from the pressure relief mechanism as emissions. In this way, the cells can be vented under controlled pressure or temperature, thereby avoiding potentially more serious accidents.

Reference herein to emissions from the battery cell includes, but is not limited to: electrolyte, dissolved or split anode and cathode pole pieces, fragments of a separation film, high-temperature and high-pressure gas generated by reaction, flame and the like.

The pressure relief mechanism on the battery cell has an important influence on the safety of the battery. For example, when a short circuit, overcharge, or the like occurs in a battery cell, thermal runaway may occur inside the battery cell, and thus, pressure or temperature may suddenly rise. In this case, the internal pressure and temperature can be released outwards by the actuation of the pressure relief mechanism, so as to prevent the explosion and the fire of the battery cells.

Because pressure release mechanism need can in time open when battery monomer takes place thermal runaway, the region is comparatively weak around the pressure release mechanism usually, like this, when pressure release mechanism received external force and assaulted, its security and reliability were relatively poor, had destroyed risk, and then probably lead to battery monomer weeping. Especially when placing under the wall at free pressure relief mechanism of battery place, for example, pressure relief mechanism sets up on the free apron of battery, and the battery monomer is inverted in the box of battery, and the apron at pressure relief mechanism place need bear whole free weight of battery this moment, and the external force that the apron received strikes greatly, easily takes place to warp, and the external force that pressure relief mechanism received just also increases so strikes, arouses pressure relief mechanism more easily to warp and is destroyed even, and then influences the security and the life of battery.

In view of the above problems, an embodiment of the present application provides a single battery, where a first wall of a housing of the single battery includes a first body and an installation body connected to the first body, and a pressure relief mechanism is arranged on the installation body, and the pressure relief mechanism is used for actuating to release pressure when internal pressure or temperature of the single battery reaches a threshold value; at least one part of the mounting body protrudes out of the surface of the first body facing the electrode assembly in the direction facing the electrode assembly in the thickness direction of the first wall, and the minimum distance between the pressure relief mechanism and the electrode assembly is smaller than that between the first body and the electrode assembly.

Like this, pressure relief mechanism receives the probability reduction of external force impact, even place first wall down, pressure relief mechanism is close to the free inside of battery more for other regions of first wall, also keeps away from the bottom of the box of battery promptly, can reduce the probability that pressure relief mechanism is directly strikeed by the external force from the bottom half, avoids the pressure relief mechanism that external force impact leads to inefficacy as far as possible.

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; 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 power tools include metal cutting electric power tools, grinding electric power tools, assembly electric power tools, and electric power 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-oil vehicle, a gas-fired vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid electric vehicle, or an extended range vehicle. The vehicle 1 may be provided with a motor 40, a controller 30 and a battery 10, the controller 30 being configured to control 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.

In order to meet different power requirements, the battery may include a plurality of battery cells, wherein the plurality of battery cells may be connected in series or in parallel or in series-parallel, and the series-parallel refers to a mixture of series connection and parallel connection. The battery may also be referred to as a battery pack. Alternatively, a plurality of battery cells may be connected in series or in parallel or in series-parallel to form a battery module, and a plurality of battery modules may be connected in series or in parallel or in series-parallel to form a battery. That is, a plurality of battery cells may directly constitute a battery, or a battery module may be first constituted and then a battery may be constituted.

For example, fig. 2 shows a schematic diagram of a battery 10 according to an embodiment of the present disclosure, and the battery 10 may include at least one battery module 200. The battery module 200 includes 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 manner of the box 11 of the embodiment of the present application, and as shown in fig. 2, the box 11 may include two parts, which are referred to as a first part 111 and a second part 112, respectively, and the first part 111 and the second part 112 are buckled together. The shape of the first and

second portions

111 and 112 may be determined according to the shape of the battery module 200 in which at least one of the first and

second portions

111 and 112 has an opening. For example, as shown in fig. 2, each of the first portion 111 and the second portion 112 may be a hollow rectangular parallelepiped and only one surface of each may be an opening surface, the opening of the first portion 111 and the opening of the second portion 112 are oppositely disposed, and the first portion 111 and the second portion 112 are fastened to each other to form the case 11 having a closed chamber.

For another example, unlike the one shown in fig. 2, only one of the first and

second 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, taking the second part 112 as a hollow rectangular parallelepiped with only one surface being an open surface and the first part 111 as a plate, the first part 111 covers the open surface of the second part 112 to form the case 11 with 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 or in series-parallel combination and then placed in the case 11 formed by buckling the first part 111 and the second part 112.

Optionally, the 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 electrically connecting the plurality of battery cells 20, such as in parallel or in series-parallel. 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 the battery cells 20 in the battery module 200 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 required. For example, fig. 3 is an example of a battery module 200. The battery may include a plurality of battery modules 200, and the battery modules 200 may be connected in series, parallel, or series-parallel.

Fig. 4 is a schematic structural diagram of a battery cell 20 according to an embodiment of the present disclosure, and fig. 5 is an exploded structural diagram of the battery cell 20 according to an embodiment of the present disclosure. As shown in fig. 4 and 5, the battery cell 20 includes an electrode assembly 22, a case 211, a cap plate 212, and a pressure relief mechanism 213. The electrode assembly 22 is accommodated in the case 211, and the cap plate 212 is adapted to cover the opening of the case 211.

The case 211 is a member for receiving the electrode assembly 22, and the case 211 may have a hollow structure with one end opened, or the case 211 may have a hollow structure with opposite ends opened. If the housing 211 is a hollow structure with an opening formed at one end, the cover plates 212 may be provided as one; if the housing 211 is a hollow structure with two opposite ends forming an opening, two cover plates 212 may be provided, and the two cover plates 212 respectively cover the openings at the two ends of the housing 211. The material of the housing 211 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The housing 211 may be various shapes such as a cylinder, a rectangular parallelepiped, etc. Illustratively, in fig. 4 and 5, the housing 211 has a rectangular parallelepiped structure, and the housing 211 has a hollow structure with an opening formed at one end.

In the battery cell 20, according to actual use requirements, there may be 1 or more electrode assemblies 22 in the case 211, and as shown in fig. 5, there are 4 independent electrode assemblies 22 in the battery cell 20.

The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. Electrode assembly 22 may be cylindrical, rectangular parallelepiped, or the like, and case 211 may be cylindrical if electrode assembly 22 has a cylindrical structure, or case 211 may have a rectangular parallelepiped structure if electrode assembly 22 has a rectangular parallelepiped structure. The electrode assembly 22 includes a tab 222 and a body part 221, wherein the tab 222 of the electrode assembly 22 may include a positive electrode tab 222a and a negative electrode tab 222b, the positive electrode tab 222a may be formed by laminating a portion of the positive electrode sheet on which the positive electrode active material layer is not coated, the negative electrode tab 222b may be formed by laminating a portion of the negative electrode sheet on which the negative electrode active material layer is not coated, and the body part 221 may be formed by laminating a portion of the positive electrode sheet on which the positive electrode active material layer is coated and a portion of the negative electrode sheet on which the negative electrode active material layer is coated or winding.

The cap plate 212 is a member covering the opening of the case 211 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the cover 212 may be adapted to the shape of the housing 211, as shown in fig. 5, the housing 211 is a rectangular parallelepiped structure, and the cover 212 is a rectangular plate structure adapted to the housing 211. The cover 212 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc., and the cover 212 may be made of the same material as or different from that of the housing 211.

The battery cell 20 may further include a cover patch 25, wherein the cover patch 25 is attached to an outer surface of the cover plate 212 for protecting the cover plate; the battery cell 20 may further include a holder 24, the holder 24 being located between the cap plate 212 and the electrode assembly 22 for separating the cap plate 212 and the electrode assembly 22.

The cap plate 212 may be provided with an electrode terminal 214, and the electrode terminal 214 is used to electrically connect with the electrode assembly 22 to output electric power of the battery cell 20. The electrode terminals 214 may include a positive electrode terminal 214a for electrical connection with the positive tab 222a and a negative electrode terminal 214b for electrical connection with the negative tab 222 b. The positive electrode terminal 214a and the positive electrode tab 222a may be directly connected or indirectly connected, and the negative electrode terminal 214b and the negative electrode tab 222b may be directly connected or indirectly connected. Illustratively, the positive electrode terminal 214a is electrically connected to the positive tab 222a via a connecting member 23, and the negative electrode terminal 214b is electrically connected to the negative tab 222b via a connecting member 23.

The pressure relief mechanism 213 is a component for relieving the pressure inside the battery cell 20, and when the pressure or temperature inside the battery cell 20 reaches a threshold value, the pressure relief mechanism 213 relieves the pressure inside the battery cell 20, specifically, the pressure relief mechanism 213 is provided with a notch groove, and when the pressure or temperature inside the battery cell 20 reaches the threshold value, the pressure relief mechanism 213 is broken along the notch groove, thereby releasing the internal pressure. The specific structure and location of the pressure relief mechanism 213 will be described in detail below with reference to the drawings.

Fig. 6 is a schematic exploded view illustrating a cover plate provided with a pressure relief mechanism according to an embodiment of the present disclosure, and as shown in fig. 5 and 6, a battery cell 20 according to an embodiment of the present disclosure may include: an electrode assembly 22; a case 21 for accommodating the electrode assembly 22, wherein the first wall 212 of the case 21 includes a first body 2121 and a mounting body 2122 connected to the first body 2121, the mounting body 2122 is provided with a pressure relief mechanism 213, the pressure relief mechanism 213 is configured to be actuated to relieve pressure when the internal pressure or temperature of the battery cell reaches a threshold value, at least a portion of the mounting body 2122 protrudes from a surface of the first body 2121 facing the electrode assembly 22 in a direction facing the electrode assembly 22 in a thickness direction of the first wall 212, and a minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 is smaller than a minimum distance between the first body 2121 and the electrode assembly 22.

The first wall 212 of the outer shell 21 is provided with the pressure relief mechanism 213, the first wall 212 of the outer shell 21 may be a wall of the housing 211, for example, a side wall or a bottom wall of the housing 211, and the pressure relief mechanism 213 may be a separate component welded to the side wall or the bottom wall, or may be a part of the side wall or the bottom wall; the first wall 212 of the housing 21 may be a cover plate 212, and the pressure relief mechanism 213 may be a separate component welded to the cover plate 212 or may be a part of the cover plate 212. For convenience of description, the first wall 212 is taken as a cover 212 as an example for description.

It should be understood that the pressure relief mechanism 213 of the present embodiment may be any possible pressure relief structure 213, and the present embodiment is not limited thereto. For example, the pressure relief mechanism 213 may be a temperature-sensitive pressure relief mechanism configured to be able to melt when the internal temperature of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value; and/or, pressure relief mechanism 213 may be a pressure sensitive pressure relief mechanism configured to rupture when the internal air pressure of battery cell 20 in which pressure relief mechanism 213 is disposed reaches a threshold value.

The mounting body 2122 and the pressure relief mechanism 213 in the embodiment of the present application may be integrally formed, or may be two separate components, and then connected by welding or the like. The mounting body 2122 and the first body 2121 of the embodiment of the present application may be formed integrally, or may be formed as two separate components and then connected by welding or the like.

The pressure relief mechanism 213 is disposed on the side of the mounting body 2122 facing the electrode assembly 22, and the minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 is smaller than the minimum distance between the first body 2121 and the electrode assembly 22, i.e., the pressure relief mechanism 213 is disposed on the mounting body 2122, so that the pressure relief mechanism 213 is closer to the electrode assembly 22 relative to the other region of the first body 2121 of the first wall 212. Specifically, the minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 in the embodiment of the present application may represent the minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 in the thickness direction, where the thickness direction is the thickness direction of the first wall 212, or the thickness direction is a direction perpendicular to the surface of the pressure relief mechanism 213 facing the electrode assembly 22. For example, in the thickness direction, if the pressure relief mechanism 213 corresponds to the main body portion 221 of the electrode assembly 22, the minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 is equal to the minimum distance between the pressure relief mechanism 213 and the main body portion 221; for another example, if the pressure relief mechanism 213 corresponds to the tab 222 in the thickness direction, the minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 is equal to the minimum distance between the pressure relief mechanism 213 and the tab 222.

Similarly, the minimum distance between the first body 2121 and the electrode assembly 22 of the embodiment of the present application also means the minimum distance between the first body 2121 and the electrode assembly 22 in the thickness direction. For example, in the thickness direction, if the first body 2121 corresponds to the main body portion 221, the minimum distance between the first body 2121 and the electrode assembly 22 is equal to the minimum distance between the first body 2121 and the main body portion 221; for another example, if the first body 2121 corresponds to the tab 222 in the thickness direction, the minimum distance between the first body 2121 and the electrode assembly 22 is equal to the minimum distance between the first body 2121 and the tab 222.

Therefore, the first wall 212 of the battery cell 20 of the embodiment of the present application is provided with the pressure relief mechanism 213, the first wall 212 includes the first body 2121 and the mounting body 2122 connected to each other, at least a portion of the mounting body 2122 protrudes from the first body 2121 toward the electrode assembly 22, and the pressure relief mechanism 213 is disposed on a side of the mounting body 2133 facing the electrode assembly 22, that is, the pressure relief mechanism 213 is closer to the electrode assembly 22 than other regions of the first body 2121 of the first wall 212, so that the probability of the pressure relief mechanism 213 being impacted by an external force is reduced, even if the first wall 212 is placed toward the bottom of the case 11 of the battery cell 20, that is, the battery cell 20 is supported by the first wall 212, the pressure relief mechanism 213 is closer to the inside of the battery cell 20 than other regions of the first wall 212, that is, farther away from the bottom of the case 11 of the battery 10, which can reduce the probability of the pressure relief mechanism 213 being directly impacted by an external force from the bottom of the case 11, the failure of the pressure relief mechanism 213 caused by the impact of external force is avoided as much as possible.

Further, the thickness of at least a part of the mounting body 2122 of the embodiment of the present application may be set to be greater than the thickness of the first body 2121, that is, the thickness of the mounting body 2122 provided with the pressure relief mechanism 213 is set to be greater, so that even if an external force acts on the region of the mounting body 2122 where the pressure relief mechanism 213 is located, the strength is increased due to the greater thickness of the region, the probability of the pressure relief mechanism 213 being damaged is reduced, and the safety of the pressure relief mechanism 213 may be further improved.

The mounting body 2122 and the first body 2121 will be described first with reference to the accompanying drawings.

Alternatively, as an embodiment, the mounting body 2122 and the first body 2121 may be two separate components. For example, the mounting body 2122 and the first body 2121 shown in fig. 6 are separate parts, fig. 7 is a plan view of the cover plate 212 provided with the pressure relief mechanism 213 corresponding to fig. 6, fig. 8 is a schematic cross-sectional view taken along the direction a-a' shown in fig. 7, fig. 9 is a partially enlarged view of the region B shown in fig. 8, and fig. 10 is a schematic view of the mounting body 2122 shown in fig. 9.

As shown in fig. 6 to 10, the mounting body 2122 includes a mounting portion 2122a and a connecting portion 2122 b. The mounting portion 2122a is used for mounting the pressure relief mechanism 213, and the connecting portion 2122b is used for connecting the mounting portion 2122a and the first body 2121. In the embodiment of the present application, the mounting portion 2122a provided with the pressure relief mechanism 213 has a thickness greater than that of the connecting portion 2122b, and the mounting portion 2122a has a thickness greater than that of the first body 2121.

Specifically, as shown in fig. 6 to 10, the connection part 2122b of the embodiment of the present application may be located at one end of the mounting part 2122a away from the electrode assembly 22, and the connection part 2122b may be a boss structure protruding from the mounting part 2122 a. Correspondingly, a corresponding boss structure is also provided on the first body 2121 of the cover plate 212, so that the connecting portion 2122b can be connected with the boss structure of the first body 2121 in a matching manner, for example, by welding, where the bold solid line in fig. 9 can be a welding point, but the embodiment of the present application is not limited thereto.

It is understood that when the mount body 2122 of the embodiment of the present application is disposed in the manner as shown in fig. 6 to 10, on the one hand, the pressure relief mechanism 213 is closer to the electrode assembly 22 than the outer surface of the first body 2121, and then the cover plate 212 is acted on by an external force, the possibility of affecting the pressure relief mechanism 213 is reduced; on the other hand, if the cover plate 212 is deformed by an external force, the area of the connection part 2122b contacting the first body 2121 around the pressure relief area 213 may be used as a main force-bearing area, and the pressure relief mechanism 213 is disposed at one end of the mounting part 2122a with a larger thickness close to the electrode assembly 22, so that the pressure relief mechanism 213 is less stressed, that is, less influenced by the deformation of the cover plate 212, due to the protection of the mounting part 2122a, and the safety and reliability of the pressure relief mechanism 213 are effectively improved.

Alternatively, as another embodiment, the mounting body 2122 and the first body 2121 may be a unitary structure. FIG. 11 is an exploded view of the pressure relief mechanism 213 and the cover 212; fig. 12 is a plan view of the cover plate 212 provided with the relief mechanism 213 corresponding to fig. 11, fig. 13 is a schematic sectional view taken along the direction C-C' shown in fig. 12, and fig. 14 is a partially enlarged view of the region D shown in fig. 13.

As shown in fig. 11 to 14, the mounting body 2122 includes a mounting portion 2122a and a connecting portion 2122 b. The mounting portion 2122a is used for mounting the pressure relief mechanism 213, and the connecting portion 2122b is used for connecting the mounting portion 2122a and the first body 2121. The mounting body 2122 is integrated with the first body 2121, for example, the mounting body 2122 of the embodiment of the present application may be formed on the cover plate 212 by stamping, etc., so that the first body 2121, the connecting portion 2122b and the mounting portion 2122a are three regions connected to each other on the cover plate 212. However, the three parts have different thicknesses, in which the mounting part 2122a of the pressure relief mechanism 213 is thicker than the connecting part 2122b, and the mounting part 2122a is thicker than the first body 2121.

Specifically, as shown in fig. 11 to 14, the connection part 2122b is located between the first body 2121 and the mounting part 2122a, and the thickness of the connection part 2122b is relatively small. For example, the thickness of the connecting portion 2122b may gradually increase from the first body 2121 to the mounting portion 2122a to form an inclined surface, but the embodiment of the present application is not limited thereto. The inclined surface of the connecting portion 2122b from the mounting portion 2122a to the first body 2121 can be uniformly stressed when the first wall 212 is subjected to an external force, so as to avoid deformation and breakage caused by concentrated stress in a certain region, thereby improving safety.

Similar to the embodiment shown in fig. 6 to 10, when the mounting body 2122 of the embodiment of the present application is disposed in the manner shown in fig. 11 to 14, on one hand, the pressure relief mechanism 213 is closer to the electrode assembly 22 than the outer surface of the first body 2121, and then the cover plate 212 is subjected to an external force, so that the possibility of affecting the pressure relief mechanism 213 is reduced; on the other hand, if the cover plate 212 is deformed by an external force, the connecting portion 2122b with a relatively small thickness around the pressure relief region 213 may serve as a main force-bearing region, and the pressure relief mechanism 213 is disposed at an end of the mounting portion 2122a with a relatively large thickness, which is close to the electrode assembly 22, and the mounting portion 2122a has a relatively large thickness, so that the strength is relatively large, and the pressure relief mechanism 213 is ensured to bear a relatively small force, that is, the pressure relief mechanism 213 is less affected by the deformation of the cover plate 212, thereby effectively improving the safety and reliability of the pressure relief mechanism 213.

The relationship between the mounting body 2122 and the first body 2121 of the embodiment of the present application is described in detail above with reference to the accompanying drawings, and the arrangement of the pressure relief mechanism 213 of the embodiment of the present application will be described in detail below with reference to fig. 6 to 14.

It is to be understood that the mounting body 2122 of the embodiment of the present application is provided with a pressure relief hole 2122c, and the pressure relief mechanism 213 is actuated to relieve pressure through the pressure relief hole 2122c when the internal pressure or temperature of the battery cell reaches a threshold value. For example, the pressure relief mechanism 213 may be disposed at an end of the pressure relief hole 2122c near the electrode assembly 22, and cover the pressure relief hole 2122 c.

Specifically, as shown in fig. 6 to 14, the mount body 2122 has a first recess 2122d, the first recess 2122d is recessed from a surface of the mount body 2122 facing the electrode assembly 22 in a direction away from the electrode assembly 22, and at least a part of the pressure relief mechanism 213 is accommodated in the first recess 2122 d. A pressure relief hole 2122c is provided in a bottom surface of the first recess 2122d so that the pressure relief mechanism 213 accommodated in the first recess 2122d can cover the pressure relief hole 2122 c.

It is to be understood that the bottom surface of the first recess 2122d of the embodiment of the present application is closer to the electrode assembly 22 than the surface of the first body 2121 facing the electrode assembly 22, so as to ensure that the thickness of the region of the mounting part 2122 where the pressure relief structure 213 is disposed is greater than the thickness of the first body 2121, and thus the strength of the mounting part 2122 is ensured, so as to improve the safety of the pressure relief structure 213.

It should be understood that, in order to ensure that the pressure relief mechanism 213 can be damaged and release the internal pressure of the battery cell 20 when the thermal runaway of the battery cell 20 occurs, a certain gap is formed between the surface of the pressure relief mechanism 213 facing the electrode assembly and the lower bracket to provide a deformation space for the pressure relief mechanism 213.

In addition, the pressure relief mechanism 213 may further include a first recess 2131, so that the thickness of the first recess 2131 is small, and the pressure relief mechanism 213 is easy to be damaged when the battery cell 20 is thermally runaway. Further, a second groove 2132 may be provided in the first groove 2131, and the second groove 2132 may be a notch provided on the bottom wall of the first groove 2131, so that the area where the thickness of the pressure relief mechanism 213 is the smallest is the area where the second groove 2132 is located, so that when the battery cell 20 is in thermal runaway, the pressure relief mechanism 213 is broken from the second groove 2132, that is, the broken position can be preset, so as to improve the flexibility and reliability of the pressure relief mechanism 213.

Alternatively, the openings of the first grooves 2131 and the openings of the second grooves 2132 may be disposed to face away from the electrode assembly 22, so that the first grooves 2131 and the second grooves 2132 are prevented from being corroded by the electrolyte inside the battery cell 20, and the service life of the pressure relief mechanism 213 is prolonged.

In the embodiment of the present application, the battery cell 20 may further include: the protective sheet 215 is disposed on a side of the pressure relief hole 2122c facing away from the electrode assembly 22, and protects the pressure relief mechanism 213, for example, from damage caused by object particles or the like to the pressure relief mechanism 213.

It is to be understood that the protective sheet 215 of the embodiments of the present application may be provided on a raised structure to facilitate installation and fixation. Specifically, as shown in fig. 6 to 14, the side of the mount body 2122 facing away from the electrode assembly 22 has a convex portion 2122e surrounding the pressure relief hole 2122c, the convex portion 2122e protrudes from the surface of the mount body 2122 facing away from the electrode assembly 22 in a direction facing away from the electrode assembly 22, and the protective sheet 215 is disposed on the surface of the convex portion 2122e facing away from the electrode assembly 22.

Alternatively, the mounting body 2122 of the embodiment of the present application may further have a second recess 2122f, the second recess 2122f is recessed from a surface of the mounting body 2122 facing away from the electrode assembly 22 in a direction facing the electrode assembly 22, the pressure relief hole 2122c penetrates through a bottom surface of the first recess 2122d and a bottom surface of the second recess 2122f, and the protrusion 2122e is located at a bottom surface of the second recess 2122 f. For example, as shown in fig. 10 to 14, the second recess 2122f is also provided around the pressure relief hole 2122c such that the convex portion 2122e is convex with respect to the bottom wall of the second recess 2122f, and the protective sheet 215 is provided on the surface of the convex portion 2122e facing away from the electrode assembly 22.

When the second recess 2122f is provided, the height of the convex portion 2122e may be set to be smaller than the depth of the second recess 2122f, for example, as shown in fig. 10 to 14, so that the surface of the protective sheet 215 facing away from the electrode assembly 22 does not exceed the outer surface of the first body 2121, and the mounting of other components on the end of the cap plate 212 facing away from the electrode assembly 22 is not affected, facilitating processing and mounting.

In the present embodiment, the first body 2121 of the cap plate 212 may also be provided with an electrode terminal 214. Considering that the tab 222 and the connection member 23 are further disposed between the body part 221 of the electrode assembly 22 and the electrode terminal 214, if the tab 222 is disposed in the case 211, the tab 222 needs to occupy a portion of the space inside the case 211, so that the space inside the case 211 that can be provided to the body part 221 of the electrode assembly 22 is reduced, resulting in a reduction in the energy density of the battery cell 20.

In view of this, as shown in fig. 6 to 14, the first wall 212 of the embodiment of the present application may further include a second body 2123, and the second body 2123 is connected to the first body 2121, for example, the second body 2123 is located at the outer edge of the first body 2121. The first body 2121 protrudes away from the electrode assembly 22 relative to the second body 2123 and forms a recessed region on the same side facing the electrode assembly 22, which may then be used to accommodate the pressure relief mechanism 213, at least a portion of the tab 222, and at least a portion of the mounting body 2122.

Alternatively, the recessed area may be used to accommodate the entire pressure relief mechanism 213, tab 222 and mounting body 2122 in order to more fully utilize the interior space of case 211 to accommodate the body portion 211 of electrode assembly 22. For example, as shown in fig. 6 to 14, in the thickness direction along the first wall 212, for the pressure relief mechanism 213 in the recessed region, the minimum distance between the surface of the mount 2122 facing the electrode assembly 22 and the main body portion 221 is a first distance, which may be the distance between the pressure relief mechanism 213 and the main body portion 221, for example; the minimum distance between the surface of the second body 2123 facing the electrode assembly 22 and the main body 221 is a second distance, and the second distance is smaller than or equal to the first distance, that is, the surface of the pressure relief mechanism 213 facing the electrode assembly 22 does not exceed the inner surface of the second body 2123, so that the pressure relief mechanism 213 does not affect the space of the main body 221 of the electrode assembly 22, and leaves more space for the main body 221 of the electrode assembly 22, which is beneficial to increasing the energy density of the battery cell 20.

The battery cell, the battery and the electric device according to the embodiment of the present application are described above, and the method and the device for manufacturing the battery cell according to the embodiment of the present application will be described below, wherein portions not described in detail may be referred to in the foregoing embodiments.

Fig. 15 shows a schematic flow diagram of a method 300 of preparing a battery cell 20 according to an embodiment of the present application. As shown in fig. 15, the method 300 may include: s310, providing electrode assembly 22; s320, providing a case 211 and a cover plate 212, wherein the electrode assembly 22 is accommodated in the case 211, the cover plate 212 includes a first body 2121 and a mounting body 2122 connected to the first body 2121, a pressure relief mechanism 213 is disposed on the mounting body 2122, the pressure relief mechanism 213 is configured to be actuated to relieve internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a threshold value, in a thickness direction of the cover plate 212, at least a portion of the mounting body 2122 protrudes from a surface of the first body 2121 facing the electrode assembly 22 in a direction facing the electrode assembly 22, and a minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 is smaller than a minimum distance between the first body 2121 and the electrode assembly 22.

Fig. 16 shows a schematic block diagram of an apparatus 400 for preparing a battery cell 20 according to an embodiment of the present application. As shown in fig. 16, the apparatus 400 may include: a first providing module 410 and a second providing module 420. The first providing module 410 is configured to: providing an electrode assembly 22; the second providing module 420 is configured to: providing a case 211 and a cover plate 212, wherein the electrode assembly 22 is accommodated in the case 211, the cover plate 212 includes a first body 2121 and a mounting body 2122 connected to the first body 2121, a pressure relief mechanism 213 is disposed on the mounting body 2122, the pressure relief mechanism 213 is configured to be actuated to relieve internal pressure or temperature of the battery cell when the pressure reaches a threshold value, in a thickness direction of the cover plate 212, at least a portion of the mounting body 2122 protrudes from a surface of the first body 2121 facing the electrode assembly 22 in a direction facing the electrode assembly 22, and a minimum distance between the pressure relief mechanism 213 and the electrode assembly 22 is smaller than a minimum distance between the first body 2121 and the electrode assembly 22.

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, comprising:

an electrode assembly (22) including a body portion (221) and tabs (222);

a case (21) for accommodating the electrode assembly (22), wherein a first wall (212) of the case (21) comprises a first body (2121) and a mounting body (2122) connected to the first body (2121), the mounting body (2122) is provided with a pressure relief mechanism (213), and the pressure relief mechanism (213) is actuated to relieve the internal pressure or temperature of the battery cell when the pressure reaches a threshold value;

wherein, in a thickness direction of the first wall (212), at least a part of the mounting body (2122) protrudes from a surface of the first body (2121) facing the electrode assembly (22) in a direction facing the electrode assembly (22), and a minimum distance between the pressure relief mechanism (213) and the main body portion (221) is smaller than a minimum distance between the first body (2121) and the main body portion (221).

2. The battery cell according to claim 1, wherein at least a portion of the mounting body (2122) has a thickness greater than a thickness of the first body (2121).

3. The battery cell according to claim 2, wherein the mounting body (2122) comprises a mounting portion (2122a) and a connecting portion (2122b), the mounting portion (2122a) is used for mounting the pressure relief mechanism (213), the thickness of the mounting portion (2122a) is greater than that of the connecting portion (2122b), and the connecting portion (2122b) is used for connecting the mounting portion (2122a) and the first body (2121).

4. The battery cell according to any of claims 1-3, wherein the mounting body (2122) is provided with a pressure relief hole (2122c), and the pressure relief mechanism (213) covers the pressure relief hole (2122c) to actuate to relieve the pressure through the pressure relief hole (2122c) when the internal pressure or temperature of the battery cell reaches a threshold value.

5. The battery cell according to claim 4, wherein the mounting body (2122) has a first recess (2122d), the first recess (2122d) being recessed from a surface of the mounting body (2122) facing the electrode assembly (22) in a direction away from the electrode assembly (22), at least a portion of the pressure relief mechanism (213) being received in the first recess (2122 d).

6. The battery cell according to claim 5, wherein a bottom surface of the first recess (2122d) is closer to the electrode assembly (22) than a surface of the first body (2121) facing the electrode assembly (22).

7. The battery cell according to claim 5, wherein the pressure relief hole (2122c) is provided at a bottom surface of the first recess (2122 d).

8. The battery cell of claim 5, further comprising:

and a protective sheet (215) disposed on a side of the pressure release hole (2122c) facing away from the electrode assembly (22) and configured to protect the pressure release mechanism (213).

9. The battery cell according to claim 8, wherein the side of the mounting body (2122) facing away from the electrode assembly (22) has a protrusion (2122e) surrounding the pressure relief hole (2122c), the protrusion (2122e) protruding from the surface of the mounting body (2122) facing away from the electrode assembly (22) in a direction away from the electrode assembly (22), and the protective sheet (215) is disposed on the surface of the protrusion (2122e) facing away from the electrode assembly (22).

10. The battery cell according to claim 9, wherein the mounting body (2122) has a second recess (2122f), the second recess (2122f) is recessed from a surface of the mounting body (2122) facing away from the electrode assembly (22) in a direction facing the electrode assembly (22), the pressure relief hole (2122c) penetrates a bottom surface of the first recess (2122d) and a bottom surface of the second recess (2122f), and the protrusion (2122e) is located at the bottom surface of the second recess (2122 f).

11. The battery cell according to claim 10, wherein the height of the protrusion (2122e) is less than the depth of the second recess (2122 f).

12. The battery cell according to any of claims 1-3, wherein the mounting body (2122) is of unitary construction with the first body (2121).

13. The battery cell according to claim 12, wherein the mounting body (2122) comprises a mounting portion (2122a) and a connecting portion (2122b), the mounting portion (2122a) is used for mounting the pressure relief mechanism (213), the connecting portion (2122b) is used for connecting the mounting portion (2122a) and the first body (2121), and the thickness of the connecting portion (2122b) gradually increases from the first body (2121) to the mounting portion (2122 a).

14. A battery cell according to any of claims 1-3, characterized in that the first wall (212) further comprises a second body (2123), the second body (2123) being connected to the first body (2121), the first body (2121) protruding with respect to the second body (2123) in a direction away from the electrode assembly (22) and forming a recessed region on the same side facing the electrode assembly (22) for accommodating the pressure relief mechanism (213) and at least a part of the mounting body (2122).

15. The battery cell of claim 14,

the first wall (212) is provided with an electrode terminal (214), the electrode terminal (214) being for electrical connection with the tab (222), the recessed region also being for receiving at least a portion of the tab (222).

16. The battery cell according to claim 15, wherein, in the thickness direction, a minimum distance between a surface of the mounting body (2122) facing the electrode assembly (22) and the main body portion (221) is a first distance, and a minimum distance between a surface of the second body (2123) facing the electrode assembly (22) and the main body portion (221) is a second distance, the second distance being less than or equal to the first distance.

17. The battery cell of any of claims 1-3,

the housing (21) includes:

a case (211) having an opening, the electrode assembly (22) being accommodated within the case (211);

a cover plate (212) for covering the opening, the first wall (212) being the cover plate (212).

18. A battery, comprising:

a battery cell according to any one of claims 1 to 17;

the box, the box is used for holding a plurality of battery monomer.

19. An electrical device, comprising: the battery of claim 18, the battery to provide electrical energy to the powered device.