CN221057596U - Battery monomer, battery and power consumption device - Google Patents

Abstract

The embodiment of the application provides a battery monomer, a battery and an electricity utilization device. The shell is provided with an accommodating space and an opening, and the top cover sealing cover is arranged at the opening. The electrode assembly is disposed in the receiving space. Wherein, the shell includes the main part region and the buffer area that connect gradually along the direction of height of shell. The buffer area is arranged on one side of the main body area, which is close to the top cover. On the section perpendicular to the height direction of the shell, the cross section of the buffer cavity formed by surrounding the buffer area is larger than the cross section of the main cavity formed by surrounding the main area. The battery monomer provided by the embodiment of the application can reduce the stress of the connecting structure between the shell and the top cover, reduce the risk of cracking of the connecting structure between the shell and the top cover, improve the problem of failure of the connecting structure between the shell and the top cover and prolong the service life of the battery monomer.

Description

Battery monomer, battery and power consumption device

Technical Field

The present application relates to the field of battery technologies, and in particular, to a battery cell, a battery, and an electric device.

Background

This section is intended to provide a background or context for embodiments of the application. The description herein is not admitted to be prior art by inclusion in this section.

The battery cell comprises a bare cell, a Mylar film, a shell and a top cover, wherein the Mylar film is coated outside the bare cell, and the shell and the top cover encapsulate the bare cell coated with the Mylar film to form the battery cell. In the related art, the case is deformed when the bare cell is cyclically expanded and breathes to generate gas, thereby stretching the connection structure between the case and the top cover, and there is a problem that the connection structure between the case and the top cover is failed.

Disclosure of utility model

In view of the foregoing, embodiments of the present application are expected to provide a battery cell, a battery and an electric device, which can improve the problem of failure of a connection structure between a housing and a top cover, and improve the service life of the battery cell.

To achieve the above object, a first aspect of an embodiment of the present application provides a battery cell, including:

the shell is provided with an accommodating space and an opening, and the top cover sealing cover is arranged at the opening;

An electrode assembly disposed in the receiving space;

The shell comprises a main body area and a buffer area which are sequentially connected in the height direction of the shell, wherein the buffer area is arranged on one side, close to the top cover, of the main body area, and the cross section perpendicular to the height direction of the shell is larger than the cross section of the main body cavity formed by surrounding the main body area.

According to the battery cell provided by the embodiment of the application, the top cover sealing cover is arranged at the opening of the shell, the shell is arranged to comprise the main body area and the buffer area which are sequentially connected along the height direction of the shell, the buffer area is arranged at one side of the main body area, which is close to the top cover, namely, is arranged close to the top cover, the cross section of the buffer cavity formed by surrounding the buffer area is larger than the cross section of the main body cavity formed by surrounding the main body area, namely, the buffer area expands outwards relative to the main body area, so that the whole shell forms a special-shaped structure, when the electrode assembly circularly expands and generates a force on the shell when the breathing generates a gas, the buffer area forms a stress buffer area of the shell, and the buffer area is arranged close to the top cover, so that the stress of a connecting structure between the shell and the top cover is reduced, the risk of cracking of the connecting structure between the shell and the top cover is reduced, the problem of failure of the connecting structure between the shell and the top cover is solved, and the service life of the battery cell is prolonged.

In some embodiments, at least a portion of the inner sidewall of the buffer region is recessed to form a groove.

Thus, when the electrode assembly is circularly expanded and the respiration generates a force to the shell, the force can be generated by the gas to the groove wall of the groove, and the pressure of the gas can be dispersed by the groove wall of the groove, so that the shearing force applied to the joint between the shell and the top cover is reduced. Furthermore, because the groove of the buffer area forms the trend of outwards expanding, the groove of the buffer area is easier to deform, and the stress of the joint between the shell and the top cover is further relieved, namely, the buffer area forms a stress buffer zone of the shell, so that the risk of cracking of a connecting structure between the shell and the top cover is reduced, the problem of failure of the connecting structure between the shell and the top cover is solved, and the service life of a battery is prolonged.

In some embodiments, at least a portion of the outer sidewall of the buffer region is convex such that the corresponding inner sidewall of the buffer region is concave to form a groove.

The inner side wall corresponding to the buffer area is recessed to form a groove by protruding at least part of the outer side wall of the buffer area, for example, by stamping and forming. In addition, the gas will form pressure to the wall of the groove, which can disperse the pressure of the gas, thereby reducing the shearing force applied to the connection between the housing and the top cover. Furthermore, because the grooves of the buffer area form a trend of outwards expanding, the grooves of the buffer area are easier to deform, and the stress of the connecting part between the shell and the top cover is further relieved, so that the problem of failure of the connecting structure between the shell and the top cover is further improved, and the service life of the battery cell is prolonged.

In some embodiments, at least a portion of the inner sidewall of the buffer region is thinned to form the recess.

The groove is formed by thinning at least part of the inner side wall of the buffer area, for example, by milling, planing and other processing technologies, the groove formed by the processing mode has higher precision and is convenient to form. In addition, the gas will form pressure to the wall of the groove, which can disperse the pressure of the gas, thereby reducing the shearing force applied to the connection between the housing and the top cover. Furthermore, as the wall thickness of the buffer area is smaller than that of the main body area, the wall of the groove can deform to a certain extent, so that the stress of the connecting part between the shell and the top cover is further relieved, the problem of failure of the connecting structure between the shell and the top cover is further solved, and the service life of the battery cell is prolonged.

In some embodiments, the wall thickness of the main body region and the wall thickness of the buffer region are x, and the recess depth of the groove in the direction perpendicular to the height direction of the shell is y, wherein y is 0.5 x.ltoreq.y.ltoreq.10x.

The concave depth of the groove in the direction perpendicular to the height direction of the shell is set to be 0.5x-10x, so that the structure of the shell is compact, the occupied installation space is small, and meanwhile, the groove has a good buffering effect on the stress of the joint between the shell and the top cover.

In some embodiments, the wall thickness of the body region is d and the wall thickness of the buffer region is p, wherein 0.3 d.ltoreq.p < d.

The wall thickness of the buffer area is set to be 0.3d-d, so that the buffer area has enough structural strength and can be deformed easily, and the buffer area has a good buffer effect on the stress of the connecting part between the shell and the top cover.

In some embodiments, the housing further comprises a connection region connected to a side of the cushioning region remote from the body region for connection with the top cover.

Here, the shell includes main part region, buffer zone and the connection region that connect gradually along the direction of height of shell, through setting up the connection region for be connected with the top cap, can make the junction between buffer zone and shell and the top cap have certain distance, further improve the buffer effect of buffer zone to the atress of junction between shell and the top cap.

In some embodiments, the height of the connection region is b and the height of the buffer region is c, wherein 0 < c.ltoreq.4b.

By setting the height c of the buffer area to be more than 0 and less than or equal to 4b, the structural compactness and the overall structural strength of the shell can be improved while the buffer effect of the buffer area on the stress of the joint between the shell and the top cover is better.

In some embodiments, the connection region is a welded connection with the top cover.

That is, the connection region of the housing is welded to the top cover to achieve the connection and sealing between the housing and the top cover.

In some embodiments, the weld penetration of the connecting area and the top cover is a, and the height of the connecting area is b, wherein a is less than or equal to b and less than or equal to 20a.

By setting the height of the connection area to be a-20a, the connection between the connection area and the top cover can be facilitated while the buffer effect of the buffer area on the stress of the connection between the shell and the top cover is better, and the buffer effect of reducing the stress of the buffer area on the connection between the shell and the top cover due to the fact that the height of the connection area is too small is avoided.

In some embodiments, the cross-sectional area of the connecting cavity formed by surrounding the connecting region is equal to the cross-sectional area of the main body cavity formed by surrounding the main body region, or the cross-sectional area of the connecting cavity formed by surrounding the connecting region is equal to the cross-sectional area of the buffer cavity formed by surrounding the buffer region.

The cross section area of the connecting cavity formed by surrounding the connecting area is equal to the cross section area of the main body cavity formed by surrounding the main body area, so that the structural compactness of the shell is improved.

The sectional area of the connecting cavity formed by surrounding the connecting area is equal to the sectional area of the buffer cavity formed by surrounding the buffer area, so that the forming of the shell is facilitated, the cost is reduced, and the production efficiency is improved.

A second aspect of an embodiment of the present application provides a battery, including at least one battery cell described above.

According to the battery provided by the embodiment of the application, the top cover sealing cover is arranged at the opening of the shell, the shell is arranged to comprise the main body area and the buffer area which are sequentially connected along the height direction of the shell, the buffer area is arranged at one side of the main body area, which is close to the top cover, namely, is arranged close to the top cover, the cross section of the buffer cavity formed by surrounding the buffer area is larger than the cross section of the main body cavity formed by surrounding the main body area, namely, the buffer area expands outwards relative to the main body area, so that the shell integrally forms a special-shaped structure, when the electrode assembly expands circularly and generates force on the shell when breathing generates gas, the buffer area forms a stress buffer area of the shell, and the buffer area is arranged close to the top cover, so that the stress of a connecting structure between the shell and the top cover is reduced, the risk of cracking of the connecting structure between the shell and the top cover is reduced, the problem of failure of the connecting structure between the shell and the top cover is solved, and the service life of a battery monomer is prolonged.

A third aspect of the embodiments of the present application provides an electric device, including the battery described above, where the battery is configured to provide electric energy for the electric device.

The electric device provided by the embodiment of the application comprises a battery, wherein the top cover sealing cover is arranged at the opening of the shell, the shell is arranged to comprise a main body area and a buffer area which are sequentially connected along the height direction of the shell, the buffer area is arranged at one side of the main body area, which is close to the top cover, namely, is arranged close to the top cover, the cross section of a buffer cavity formed by surrounding the buffer area is larger than the cross section of a main body cavity formed by surrounding the main body area, namely, the buffer area expands outwards relative to the main body area, so that the whole shell forms a special-shaped structure, when the electrode assembly expands circularly and generates a force on the shell when breathing generates a gas, the buffer area forms a stress buffer area of the shell, and the buffer area is arranged close to the top cover, thereby reducing the stress of a connecting structure between the shell and the top cover, reducing the risk of cracking the connecting structure between the shell and the top cover, improving the problem of failure of the connecting structure between the shell and the top cover, and prolonging the service life of a battery monomer.

Drawings

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

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

FIG. 3 is a schematic structural view of a housing according to a first embodiment of the present application;

FIG. 4 is a partial cross-sectional view of FIG. 3;

FIG. 5 is a partial cross-sectional view of a housing provided by a second embodiment of the application, the cross-sectional position being the same as that of FIG. 4;

Fig. 6 is a partial cross-sectional view of a housing provided in a third embodiment of the present application, the cross-sectional position being the same as that of fig. 4.

Description of the reference numerals

1. A housing; 1a, an accommodating space; 1b, opening; 11. a body region; 12. a buffer region; 12a, grooves; 13. a connection region; 10. a battery cell; 20. a battery box; 100. a battery; 200. a controller; 300. a motor; 1000. a vehicle.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments of the present application and the technical features of the embodiments may be combined with each other, and the detailed description in the specific embodiments should be interpreted as an explanation of the gist of the present application and should not be construed as unduly limiting the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof, are intended to cover a non-exclusive inclusion.

In the description of embodiments of the present application, the technical terms "first," "second," "third," etc. are used merely to distinguish between different objects and should not be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In this context, the character "/" generally indicates that the associated object is an "or" relationship.

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "length", "width", "thickness", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", "height direction", "first direction", "second direction", etc. are based on the orientation or positional relationship shown in the drawings, only for convenience of describing the embodiments of the present application and for simplifying the description, but do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured, operated, or used in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the term "contact" is to be understood in a broad sense as either direct contact or contact across an intermediate layer, as either contact with substantially no interaction force between the two in contact or contact with interaction force between the two in contact.

With the development of clean energy, more and more devices use electric energy as driving energy, and further, as a power battery capable of storing more electric energy and being charged and discharged repeatedly, for example, a lithium ion battery is rapidly developed. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and various fields such as aerospace and the like.

With the great popularization of new energy automobiles by the country, the new energy automobiles come to develop at great opportunity. Safety and stability of automobiles have been of great concern. Therefore, improving the safety of the new energy automobile is one of the important factors for determining whether the new energy automobile can be popularized rapidly. The battery module is used as a main component of a battery pack of the new energy automobile, and improving the safety of the battery module is an important way for improving the safety of the new energy automobile.

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 embodiment of the present application. The battery cells may be in the shape of a cylinder, a cuboid, or other shapes, etc., which are not limited in this embodiment of the application.

Reference to a battery in accordance with an embodiment 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, or the like. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly consists of a positive plate, a negative plate and a separation membrane. The battery cell mainly relies on metal ions to move between the positive and negative electrode plates to operate. The positive plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protrudes out of the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer is used as a positive electrode lug. 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 electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector without the negative electrode active material layer protrudes out of the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer is used as a negative electrode tab. 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 high current is passed without fusing, the number of positive electrode lugs is multiple and stacked together, and the number of negative electrode lugs is multiple and stacked together. The material of the separator may be PP (polypropylene) or PE (polyethylene).

The battery cell also comprises a packaging film and a shell, wherein the packaging film is coated outside the electrode assembly, and the shell encapsulates the electrode assembly coated with the packaging film to form the battery cell. The packaging film may be mylar film (mylar film) and the outer shell may be aluminum. After the electrode assembly is wound and formed, the Mylar coating process and the shell entering process are carried out to complete the encapsulation of the Mylar and the shell. The Mylar film has the functions of sealing and protecting the electrode assembly, and can effectively insulate the electrode assembly and the shell from each other, so that the internal short circuit of the battery cell is avoided. The shell plays a role in protection.

In the related art, when a force is applied to the case while the electrode assembly is cyclically expanded and breathed (a process of charging and discharging) to generate a gas, the case is outwardly deformed, thereby stretching a connection structure between the case and the top cover, and there is a problem in that the connection structure between the case and the top cover is deteriorated.

In order to solve the problem of failure of a connecting structure between a housing and a top cover and improve the service life of a battery cell, embodiments of the present application provide a battery cell including the housing, the top cover and an electrode assembly. The shell is provided with an accommodating space and an opening, and the top cover sealing cover is arranged at the opening. The electrode assembly is disposed in the receiving space. Wherein, the shell includes the main part region and the buffer area that connect gradually along the direction of height of shell. The buffer area is arranged on one side of the main body area, which is close to the top cover. On the section perpendicular to the height direction of the shell, the cross section of the buffer cavity formed by surrounding the buffer area is larger than the cross section of the main cavity formed by surrounding the main area.

According to the battery cell provided by the embodiment of the application, the top cover sealing cover is arranged at the opening of the shell, the shell is arranged to comprise the main body area and the buffer area which are sequentially connected along the height direction of the shell, the buffer area is arranged at one side of the main body area, which is close to the top cover, namely, is arranged close to the top cover, the cross section of the buffer cavity formed by surrounding the buffer area is larger than the cross section of the main body cavity formed by surrounding the main body area, namely, the buffer area expands outwards relative to the main body area, so that the whole shell forms a special-shaped structure, and therefore, when the electrode assembly expands circularly and generates a force on the shell in the process of charging and discharging, the buffer area forms a stress buffer area of the shell, and the buffer area is arranged close to the top cover, so that the stress of the connecting structure between the shell and the top cover is reduced, the risk of cracking of the connecting structure between the shell and the top cover is reduced, the problem of failure of the connecting structure between the shell and the top cover is solved, and the service life of the battery cell is prolonged.

The technical scheme described by the embodiment of the application is suitable for the battery and the power utilization device using the battery.

The battery provided by the embodiment of the application is a battery cell comprising at least one battery cell provided by the embodiment of the application. One or more battery cells to provide a single physical module of higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, or the like. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The electric device may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, or the like. The vehicle can be a fuel oil vehicle, a fuel 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; spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the application does not limit the electric device in particular.

It should be noted that, the technical solution described in the embodiments of the present application is not limited to the above-described battery and power consumption device, but may be applied to all batteries including a case and power consumption devices using the batteries, but for simplicity of description, the following embodiments are all described by taking an electric vehicle as an example.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the application. The controller 200, the motor 300, and the battery 100 may be provided inside the vehicle 1000, and the controller 200 is used to control the battery 100 to supply power to the motor 300. For example, the battery 100 may be provided at the bottom or the head or tail of the vehicle 1000. Battery 100 may be used to power vehicle 1000, for example, battery 100 may be used as an operating power source for vehicle 1000, for circuitry of vehicle 1000, for example, for operating power requirements during start-up, navigation, and operation of vehicle 1000. In another embodiment of the present application, battery 100 may not only serve as an operating power source for vehicle 1000, but may also serve as a driving power source for vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 1000.

To meet various demands for power use, the battery 100 may include a plurality of battery cells 10, and the battery cells 10 refer to the smallest units constituting a battery module or a battery pack. The plurality of battery cells 10 can be connected in series or in parallel, and the series-parallel connection refers to that the plurality of battery cells 10 are connected in series or in parallel. The plurality of battery cells 10 can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells 10 is accommodated in the box body; of course, the battery 100 may be a form of a plurality of battery cells 10 connected in series or parallel or series-parallel to form a battery 100 module, and a plurality of battery 100 modules connected in series or parallel or series-parallel to form a whole and accommodated in a case. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for making electrical connection between the plurality of battery cells 10. Wherein each battery cell 10 may be a secondary battery or a primary battery; but not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. The battery cell 10 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc.

Fig. 2 is an exploded view of a battery according to an embodiment of the present application. The battery 100 includes a battery case 20 and at least one battery cell 10 (not shown), and the battery cell 10 is disposed in an installation space of the battery case 20.

The battery case 20 may have a simple three-dimensional structure such as a rectangular parallelepiped, a cylinder, or a sphere, or may have a complex three-dimensional structure formed by combining simple three-dimensional structures such as a rectangular parallelepiped, a cylinder, or a sphere. The battery case 20 may be made of an alloy material such as aluminum alloy or iron alloy, a polymer material such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

The battery case 20 is for accommodating the battery cells 10, and the battery case 20 may have various structures. In some embodiments, the battery case 20 may include a first case portion and a second case portion that are mutually covered, and the first case portion and the second case portion together define an installation space for accommodating the battery cell 10. The second case part may be a hollow structure having one end opened, the first case part being a plate-shaped structure, the first case part being covered on the opening side of the second case part to form a battery case 20 having an installation space; the first case portion and the second case portion may each be a hollow structure having one side opened, and the opening side of the first case portion is closed to the opening side of the second case portion to form the battery case 20 having an installation space. Of course, the first and second case portions may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the tightness after the first box body is connected with the second box body, a sealing element, such as a sealant, a sealing ring and the like, can be arranged between the first box body and the second box body.

The first housing portion may also be referred to as an upper cover and the second housing portion may also be referred to as a lower cover, assuming that the first housing portion is covered on top of the second housing portion.

In the battery 100, the number of the battery cells 10 may be one or more. If there are multiple battery cells 10, the multiple battery cells 10 may be connected in series or parallel or a series-parallel connection, where a series-parallel connection refers to that there are both series connection and parallel connection among the multiple battery cells 10. The plurality of battery cells 10 can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells 10 is accommodated in the battery box 20; of course, a plurality of battery cells 10 may be connected in series or parallel or series-parallel to form a battery module, and then connected in series or parallel or series-parallel to form a whole and be accommodated in the battery box 20.

Illustratively, the battery cell 10 may include a lithium ion battery cell, a sodium ion battery cell, a magnesium ion battery cell, or the like, which the embodiment of the application is not limited to. The battery cell 10 may have a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, which is not limited in this embodiment of the present application. The battery cells 10 are generally divided into three types in a package manner: the cylindrical battery cell, the square battery cell and the soft package battery cell are not limited in this embodiment.

Referring to fig. 3 to 6, a battery cell 10 according to an embodiment of the present application includes a case 1, a top cover, and an electrode assembly. The housing 1 has an accommodation space 1a and an opening 1b, and a top cover sealing cover is provided at the opening 1 b. The electrode assembly is disposed in the receiving space 1 a. Wherein the housing 1 includes a main body region 11 and a buffer region 12 connected in sequence in the height direction of the housing 1. The buffer area 12 is disposed on one side of the body area 11 near the top cover. In a cross section perpendicular to the height direction of the housing 1, the cross section of the buffer cavity surrounded by the buffer region 12 is larger than the cross section of the main cavity surrounded by the main region 11.

Here, the housing 1 may be in a cylindrical body, a flat body, a rectangular parallelepiped, or other shape, etc. When the housing 1 is cylindrical, the height direction of the housing 1 is the axial direction of the housing 1.

The cross-sectional area of the buffer cavity formed by surrounding the buffer region 12 refers to the cross-sectional area of the buffer cavity formed by surrounding the buffer region 12 taken along a plane perpendicular to the height direction of the housing 1. The cross-sectional area of the body cavity formed by surrounding the body region 11 means the cross-sectional area of the body cavity formed by surrounding the body region 11 taken along a plane perpendicular to the height direction of the housing 1.

The buffer cavity defined by the buffer region 12 has a larger cross-sectional area than the body cavity defined by the body region 11, that is, the buffer region 12 expands outwardly relative to the body region 11. Here, the buffer region 12 may be partially expanded outward with respect to the main body region 11, or may be entirely expanded outward with respect to the main body region 11. For example, when the housing 1 is cylindrical, the inner diameter of the buffer area 12 may be larger than the inner diameter of the body area 11.

In some embodiments, when the housing 1 has a rectangular parallelepiped shape, the buffer region 12 may be a partial or whole region of the long side that is expanded outward with respect to the main body region 11, or a partial or whole region of the short side that is expanded outward with respect to the main body region 11.

The top cap is generally perpendicular to the side of shell 1, shell 1 outwards warp, can produce the shearing force that is parallel to the top cap at the junction between shell 1 and the top cap, buffer zone 12 outwards expands for main part region 11, when electrode assembly cyclic expansion and breathe when producing the effect of gaseous to shell 1, buffer zone 12 forms the atress buffer zone of shell 1 to reduce the shearing force that junction between shell 1 and the top cap received, reduced the risk of the connection structure fracture between shell 1 and the top cap, improve the problem that connection structure between shell 1 and the top cap became invalid, improve battery cell 10's life.

According to the battery cell 10 provided by the embodiment of the application, the top cover sealing cover is arranged at the opening 1b of the shell 1, the shell 1 is arranged to comprise the main body area 11 and the buffer area 12 which are sequentially connected along the height direction of the shell 1, the buffer area 12 is arranged at one side of the main body area 11 close to the top cover, namely close to the top cover, the cross section perpendicular to the height direction of the shell 1 is larger than the cross section of the main body cavity formed by surrounding the main body area 11 by surrounding the buffer area 12, that is, the buffer area 12 expands outwards relative to the main body area 11, so that the shell 1 integrally forms a special-shaped structure, when the electrode assembly circularly expands and generates force on the shell 1 when breathing to generate gas, the buffer area 12 forms a stress buffer area of the shell 1, and the buffer area 12 is arranged close to the top cover, so that the stress of a connecting structure between the shell 1 and the top cover is reduced, the risk of cracking of the connecting structure between the shell 1 and the top cover is reduced, the problem of failure of the connecting structure between the shell 1 and the top cover is improved, and the service life of the battery cell 10 is prolonged.

It should be noted that the specific structure type of the buffer area 12 is not limited herein. In some embodiments, referring to fig. 4-6, at least a portion of the inner sidewall of the buffer region 12 is recessed to form a recess 12a.

Here, the recess 12a may be formed by recessing a part of the inner side wall of the buffer region 12, or the recess 12a may be formed by recessing the entire inner side wall of the buffer region 12.

At least a portion of the inner side wall of the buffer region 12 is recessed to form a groove 12a, so that when the electrode assembly is cyclically expanded and the respiration generates a force to the case 1, the gas will form a pressure on the groove wall of the groove 12a, and the groove wall of the groove 12a can disperse the pressure of the gas, thereby reducing the shearing force applied to the junction between the case 1 and the top cover. Furthermore, due to the outward expansion trend of the grooves 12a of the buffer area 12, the grooves 12a of the buffer area 12 are easier to deform, so that the stress of the connection part between the shell 1 and the top cover is further relieved, namely, the buffer area 12 forms a stress buffer area of the shell 1, thereby reducing the risk of cracking of the connection structure between the shell 1 and the top cover, improving the problem of failure of the connection structure between the shell 1 and the top cover, and prolonging the service life of the battery cell 10.

The grooves 12a may be formed in various ways.

In some embodiments, referring to fig. 6, at least a portion of the inner sidewall of the buffer region 12 is thinned to form a recess 12a.

Here, the portion of the inner side wall of the buffer region 12 in the circumferential direction may be thinned to form the groove 12a, or the portion of the inner side wall of the buffer region 12 in the circumferential direction may be thinned to form the groove 12a.

In this embodiment, at least a portion of the inner side wall of the buffer region 12 is thinned to form the groove 12a, that is, the wall thickness of the buffer region 12 is smaller than that of the body region 11.

By thinning at least part of the inner side wall of the buffer area 12 to form the groove 12a, for example, by milling, planing or the like, the groove 12a is formed by thinning at least part of the inner side wall of the buffer area 12, the accuracy of the groove 12a formed by this processing is high, and the molding is convenient. In addition, the gas may form a pressure to the wall of the groove 12a, and the wall of the groove 12a may disperse the pressure of the gas, thereby reducing the shearing force applied to the connection between the housing 1 and the top cover. Furthermore, as the wall thickness of the buffer area 12 is smaller than that of the main body area 11, the gas can deform the wall of the groove 12a to a certain extent, so that the stress at the joint between the shell 1 and the top cover is further relieved, the problem of failure of the connecting structure between the shell 1 and the top cover is further improved, and the service life of the battery cell 10 is prolonged.

In some embodiments, referring to FIG. 6, the wall thickness of the body region 11 is d and the wall thickness of the buffer region 12 is p, wherein 0.3 d.ltoreq.p < d. That is, the wall thickness of the buffer region 12 is 0.3 times or more the wall thickness of the body region 11, and is smaller than the wall thickness of the body region 11.

P is, for example, 0.3d, 0.35d, 0.4d, 0.45d, 0.5d, 0.55d, 0.6d, 0.65d, 0.7d, 0.75d, 0.8d, 0.85d, 0.9d, 0.95d, or d, etc.

The wall thickness of the main body region 11 is d, the wall thickness of the buffer region 12 is p 0.3d-d, in other words, the recess depth of the groove 12a in the direction perpendicular to the height direction of the housing 1 is 0 to 0.7d.

It will be appreciated that in this embodiment, the greater the recess depth of the recess 12a in the direction perpendicular to the height direction of the housing 1, the smaller the wall thickness of the cushioning region 12, the more likely the cushioning region 12 will deform, the better the cushioning effect against the force applied to the junction between the housing 1 and the top cover, but the lower the structural strength of the cushioning region 12.

By setting the wall thickness of the buffer area 12 to 0.3d-d, the buffer area 12 can have enough structural strength and can be easily deformed at the same time, so that the buffer area 12 has a better buffer effect on the stress of the connecting part between the shell 1 and the top cover.

In other embodiments, referring to fig. 4 to 5, at least a portion of the outer sidewall of the buffer area 12 is protruded, so that the corresponding inner sidewall of the buffer area 12 is recessed to form a groove 12a.

Here, the outer side wall of the buffer region 12 may be partially protruded in the circumferential direction so that the inner side wall corresponding to the buffer region 12 is recessed to form the groove 12a, or the entire outer side wall of the buffer region 12 may be protruded in the circumferential direction so that the inner side wall corresponding to the buffer region 12 is recessed to form the groove 12a.

In this embodiment, the wall thickness of the buffer zone 12 is equal to the wall thickness of the body zone 11.

The recess 12a is formed by projecting at least a portion of the outer side wall of the buffer region 12 such that the corresponding inner side wall of the buffer region 12 is recessed, for example, by press forming, and projecting at least a portion of the outer side wall of the buffer region 12 such that the corresponding inner side wall of the buffer region 12 is recessed to form the recess 12a. In addition, the gas may form a pressure to the wall of the groove 12a, and the wall of the groove 12a may disperse the pressure of the gas, thereby reducing the shearing force applied to the connection between the housing 1 and the top cover. Furthermore, due to the outward expansion trend of the grooves 12a of the buffer area 12, the grooves 12a of the buffer area 12 are more prone to deformation, so that the stress at the connection part between the housing 1 and the top cover is further relieved, the problem of failure of the connection structure between the housing 1 and the top cover is further improved, and the service life of the battery cell 10 is prolonged.

The recess depth of the groove 12a in the direction perpendicular to the height direction of the housing 1 is not limited here.

In some embodiments, referring to fig. 4 to 5, the wall thickness of the main body region 11 and the wall thickness of the buffer region 12 are x, and the recess depth of the recess 12a in the direction perpendicular to the height direction of the housing 1 is y, wherein 0.5 x.ltoreq.y.ltoreq.10x. That is, the recess 12a has a recess depth in a direction perpendicular to the height direction of the housing 1 of 0.5 times or more the wall thickness of the main body region 11 and the wall thickness of the buffer region 12 and 10 times or less the wall thickness of the main body region 11 and the wall thickness of the buffer region 12.

Y is, for example, 0.5x, 1x, 1.5x, 2x, 2.5x, 3x, 3.5x, 4x, 4.5x, 5x, 5.5x, 6x, 6.5x, 7x, 7.5x, 8x, 8.5x, 9x, 9.5x, or 10x, etc.

It will be appreciated that in this embodiment, the greater the recess depth of the recess 12a in the direction perpendicular to the height direction of the housing 1, the better the cushioning effect against the force applied to the junction between the housing 1 and the top cover, but this results in a larger protruding space of the cushioning region 12 outwards, resulting in a larger footprint of the housing 1.

By setting the recess depth of the recess 12a in the direction perpendicular to the height direction of the housing 1 to 0.5x-10x, the structure of the housing 1 can be compact, the occupied installation space is small, and meanwhile, the recess 12a has a good buffering effect on the stress of the connection part between the housing 1 and the top cover.

It is to be understood that the specific form in which the opening 1b is formed is not limited herein.

In some embodiments, referring to fig. 4 to 6, the housing 1 further includes a connection region 13, and the connection region 13 is connected to a side of the buffer region 12 away from the main body region 11, for connection with a top cover.

The connection region 13 is connected to a side of the buffer region 12 remote from the body region 11, that is, the housing 1 includes the body region 11, the buffer region 12, and the connection region 13, which are sequentially connected in the height direction of the housing 1.

The connection region 13 is adapted to be connected to a top cover, i.e. an opening 1b is formed in the side of the connection region 13 remote from the buffer region 12, and a top cover sealing cover is provided at the opening 1b of the connection region 13.

Here, the housing 1 includes a main body region 11, a buffer region 12, and a connection region 13 sequentially connected in the height direction of the housing 1, and by providing the connection region 13 for connection with the top cover, the connection between the buffer region 12 and the housing 1 and the top cover can be made to have a certain distance, further enhancing the buffer effect of the buffer region 12 on the stress of the connection between the housing 1 and the top cover.

In other embodiments, the housing 1 may be provided without the connection region 13, and the opening 1b may be formed directly on the side of the buffer region 12 away from the main body region 11, i.e., the top cover is connected to the side of the buffer region 12 away from the main body region 11.

In some embodiments, referring to FIGS. 4-6, the height of the connection region 13 is m and the height of the buffer region 12 is n, where 0 < n.ltoreq.4m.

The height of the buffer region 12 is, for example, 0.1m, 0.2m, 0.5m, 0.8m, 1m, 1.5m, 1.8m, 2m, 2.5m, 3m, 3.3m, 3.5m, 3.8m, 4m, or the like.

It will be appreciated that the height of the cushioning region 12 is too small and that the cushioning region 12 is less effective at cushioning the forces applied to the connection between the housing 1 and the top cover. Too high a height of the buffer zone 12 can affect the compactness and overall structural strength of the housing 1.

By setting the height n of the buffer area 12 to 0 < n.ltoreq.4m, the structural compactness and the overall structural strength of the housing 1 can be improved while the buffer effect of the buffer area 12 on the stress of the connection part between the housing 1 and the top cover is good.

The connection between the housing 1 and the top cover is not limited herein.

In some embodiments, referring to fig. 4 to 6, the connection region 13 is welded to the top cover.

That is, the connection region 13 of the housing 1 is welded to the top cover to achieve a connection and seal between the housing 1 and the top cover.

Of course, in some embodiments, the housing 1 and the top cover may be in a clamping, plugging or fastening connection.

In some embodiments, referring to FIG. 6, the weld penetration of the connection region 13 is r, and the height of the connection region 13 is m, where r.ltoreq.m.ltoreq.20r.

The weld penetration refers to the distance between the deepest position of the melted portion of the base material and the surface of the base material. I.e. the distance in the butt weld from the end face of the opening 1b of the connection region 13 to the deepest part of the melting zone.

It will be appreciated that the height of the connection region 13 is too small, which on the one hand is detrimental to the connection between the connection region 13 and the top cover, i.e. is detrimental to the welding between the connection region 13 and the top cover, and on the other hand the force of the buffer region 12 is easily transferred to the connection between the connection region 13 and the top cover, thereby reducing the buffer effect of the force of the buffer region 12 on the connection between the housing 1 and the top cover. Too high a height of the connection region 13 may result in a poor cushioning effect of the cushioning region 12 against the forces applied at the connection between the housing 1 and the top cover.

By setting the height of the connection region 13 to r-20r, the connection between the connection region 13 and the top cover can be facilitated while the buffer effect of the buffer region 12 on the stress of the connection between the housing 1 and the top cover is better, and the buffer effect of reducing the stress of the buffer region 12 on the connection between the housing 1 and the top cover due to the too small height of the connection region 13 can be avoided.

In some embodiments, referring to fig. 4 to 6, the cross-sectional area of the connecting cavity formed by surrounding the connecting region 13 is equal to the cross-sectional area of the main cavity formed by surrounding the main region 11, or the cross-sectional area of the connecting cavity formed by surrounding the connecting region 13 is equal to the cross-sectional area of the buffer cavity formed by surrounding the buffer region 12.

The cross-sectional area of the connecting cavity formed by surrounding the connecting region 13 refers to the cross-sectional area of the connecting cavity formed by surrounding the connecting region 13 cut along a plane perpendicular to the height direction of the housing 1.

By setting the cross-sectional area of the connection cavity formed by enclosing the connection region 13 to be equal to the cross-sectional area of the body cavity formed by enclosing the body region 11, the structural compactness of the housing 1 is facilitated to be improved.

The cross section area of the connecting cavity formed by surrounding the connecting area 13 is equal to the cross section area of the buffer cavity formed by surrounding the buffer area 12, so that the forming of the shell 1 is facilitated, the cost is reduced, and the production efficiency is improved.

In the description of the present application, reference to the term "one embodiment," "in some embodiments," "in other embodiments," "in yet other embodiments," or "exemplary" etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In the present application, the schematic representations of the above terms are not necessarily for the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the various embodiments or examples described in the present application and the features of the various embodiments or examples may be combined by those skilled in the art without contradiction.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims (13)

1. A battery cell, comprising:

the shell is provided with an accommodating space and an opening, and the top cover sealing cover is arranged at the opening;

An electrode assembly disposed in the receiving space;

The shell comprises a main body area and a buffer area which are sequentially connected in the height direction of the shell, wherein the buffer area is arranged on one side, close to the top cover, of the main body area, and the cross section perpendicular to the height direction of the shell is larger than the cross section of the main body cavity formed by surrounding the main body area.

2. The battery cell of claim 1, wherein at least a portion of the inner sidewall of the buffer region is recessed to form a groove.

3. The battery cell of claim 2, wherein at least a portion of the outer sidewall of the buffer region is convex such that the corresponding inner sidewall recess of the buffer region forms a groove.

4. The battery cell of claim 2, wherein at least a portion of the inner side wall of the buffer region is thinned to form the recess.

5. A battery cell according to any one of claims 2 to 3, wherein the wall thickness of the main body region and the wall thickness of the buffer region are each x, and the recess depth of the recess in a direction perpendicular to the height direction of the case is y, wherein 0.5 x.ltoreq.y.ltoreq.10x.

6. The battery cell of claim 4, wherein the body region has a wall thickness d and the buffer region has a wall thickness p, wherein 0.3d +.p < d.

7. A battery cell according to any one of claims 1 to 3, wherein the housing further comprises a connection region connected to a side of the buffer region remote from the body region for connection with the top cover.

8. The battery cell of claim 7, wherein the connection region has a height of m and the buffer region has a height of n, wherein 0 < n.ltoreq.4m.

9. The battery cell of claim 7, wherein the connection region is a welded connection with the top cap.

10. The battery cell of claim 9, wherein the weld penetration of the connection region to the top cap is r and the height of the connection region is m, wherein r.ltoreq.m.ltoreq.20r.

11. The battery cell of claim 7, wherein the cross-sectional area of the connecting cavity defined by the connecting region is equal to the cross-sectional area of the main body cavity defined by the main body region, or the cross-sectional area of the connecting cavity defined by the connecting region is equal to the cross-sectional area of the buffer cavity defined by the buffer region.

12. A battery comprising at least one cell according to any one of claims 1-11.

13. An electrical device comprising the battery of claim 12 for providing electrical energy to the electrical device.