CN218414707U - Battery cell, battery and power consumption device - Google Patents

Abstract

The application relates to a battery monomer, a battery and an electric device, which comprises a shell, an electrode assembly and a supporting body, wherein the electrode assembly is accommodated in the shell and comprises a straight part and bending parts positioned on two sides of the straight part; the support body is located between an outer surface of the bent portion and an inner wall of the case in a first direction, the support body being configured to block the case from being depressed toward the electrode assembly, the first direction being a direction in which the straight portion and the bent portion are arranged side by side. In this application, when the casing has the trend of indent under the influence of battery monomer internal and external pressure difference or temperature, blockked and resist its deformation that caves in by the supporter, casing sunken degree can be alleviated greatly, helps making the casing side keep better plane degree. When the battery monomer constitutes and forms battery module, because of the casing side plane degree is better, the moulding is good between the free casing of each battery, can avoid because of the safety problem that the moulding is bad to cause.

Description

Battery cell, battery and power consumption device

Technical Field

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

Background

With the national support of policies for new energy industries, the new energy industries are rapidly developed in recent years, the demand of lithium ion batteries is rapidly increased, higher requirements are put on the energy density of the batteries, the thickness of the shell of a battery monomer is thinner and thinner, and the thinnest shell reaches 0.4mm.

The thickness of the shell becomes thinner, the corresponding tensile strength is reduced, and the shell is more easily influenced by temperature/internal and external pressure difference in the single battery manufacturing process, so that the flatness consistency of the shell is more deteriorated, and the safety of the battery is greatly influenced.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, the present application provides a battery cell, a battery, and an electric device, which can alleviate the problem of battery safety caused by poor flatness uniformity of a battery cell case.

In a first aspect, the present application provides a battery cell, including a case, an electrode assembly and a support, the electrode assembly being accommodated in the case, the electrode assembly including a straight portion and bent portions located at both sides of the straight portion; the support body is located between an outer surface of the bent portion and an inner wall of the case in a first direction, the support body being configured to block the case from being depressed toward the electrode assembly, the first direction being a direction in which the straight portion and the bent portion are arranged side by side.

Among the technical scheme of this application embodiment, when the casing has the trend of indent under the influence of the interior external differential pressure of battery monomer or temperature, blockked and resist its sunken deformation by the supporter, the sunken degree of casing can be alleviated greatly, helps making the casing side keep better plane degree. When the battery monomer constitutes and forms battery module, because of the casing side plane degree is better, the moulding is good between the free casing of each battery, can avoid because of the safety problem that the moulding is bad to cause.

In some embodiments, the support has a hardness greater than that of the electrode assembly. At this time, the hardness of the support body is higher than that of the electrode assembly, when the shell is concave, the support body can absorb or resist most of the deformation force of the concave part of the shell, and can provide strong support for the shell to resist the concave deformation of the shell, so that the forced deformation of the electrode assembly can be relieved, and the electrode assembly is protected.

In some embodiments, the first surface of the support body facing the electrode assembly is formed in a curved surface corresponding to the shape of the outer surface of the bent portion. At this moment, the first surface of the support body and the outer surface of the bending part are the curved surfaces in adaptation, and the first surface can be in large-surface contact with the bending part. When the shell is concave, the support body resists the support source of the concave shell to be the electrode assembly, when the first surface is in contact with the large surface of the outer surface of the bent part, the reaction force of the support body received by the bent part is uniform, and the electrode assembly is prevented from being damaged due to local deformation of the bent part.

In some embodiments, in the first direction, the second surface of the support body facing the shell is located between the inner wall of the shell and the outer surface of the bent portion facing the shell. At this moment, the thickness of the support body in the first direction is large, and the support body can have good strength and can effectively prevent the shell from sinking inwards. Meanwhile, the support body can be surrounded on the outer surface of the bent part, so that the electrode assembly can be well protected

In some embodiments, in the first direction, an outer surface of the bent portion facing the housing is flush with a second surface of the support body facing the housing. When the second surface of the support body is flush with the outer surface of the bending part in the first direction, the bending part can be directly abutted against the shell or set to be a shorter distance, so that the size of the battery cell can be reduced, and the energy density of the battery cell is improved.

In some embodiments, at least two electrode assemblies are included, and all of the electrode assemblies are sequentially stacked in a second direction, which is a thickness direction of the electrode assemblies. The electrode assembly is a main place where electrochemical reaction occurs in the battery cells, and when the electrode assembly comprises at least two electrode assemblies, the electric capacity of the battery cells is large, so that the cruising ability of the battery cells can be improved.

In some embodiments, along the first direction, a projection of the support body and a projection of any one of the electrode assemblies have an overlap region. When the projection of the support body in the first direction and the projection of any electrode assembly have an overlapping region, the support body is uniformly arranged between the bending part of each electrode assembly and the shell, so that the support body can prevent the shell from being recessed towards any electrode assembly, and the flatness of each position of the shell is ensured.

In some embodiments, along the second direction, a projection of the support body in the first direction does not exceed a projection of the outermost electrode assembly in the first direction. Because the structural strength of the corners in the shell is high, the battery monomer is not easy to indent under the action of the temperature difference/pressure difference between the inside and the outside of the battery monomer, and at the moment, the electrode assembly on the outermost side and the corners form an empty space without a support body, so that the setting cost of the support body can be reduced.

In some embodiments, the supporting body includes at least one sub-supporting body, and in the second direction, one sub-supporting body is disposed in the accommodating space between each two adjacent bending portions and the housing. At the moment, when the shell is concave, the sub-supporting bodies can apply force to the bending parts of the two electrode assemblies forming the accommodating space, the concave deformation of the shell is blocked, the stress of each electrode assembly is equal to the average, and the stress of the electrode assembly is smaller and safer.

In some embodiments, the support body comprises a plurality of sub-support bodies, each sub-support body being connected in series in the second direction. At the moment, the sub-supporting bodies are connected to form a whole, the inward concave deformation of the shell can be resisted by means of force, the inward concave force of the shell, which is received by one sub-supporting body, is dispersed to other sub-supporting bodies through the sub-supporting bodies, and then the acting force applied to each electrode assembly can be dispersed, so that the protection of the electrode assembly is improved.

In some embodiments, the battery cell further includes an insulating film between the electrode assembly and the case, the insulating film for insulating and separating the electrode assembly from the case. The case and the electrode assembly are electrically insulated by an insulating film, and the case is prevented from leaking electricity.

In some embodiments, the support is located between the electrode assembly and the insulating film. Because the insulating film is the rete, its thickness is thinner, and it can follow the casing indent when the casing takes place the indent, and at this moment, the supporter realizes blockking to casing indent deformation through hindering the indent of insulating film.

In some embodiments, the support is located between the insulating film and the housing. At this time, the support body is positioned outside the insulating film and is not in direct contact with the electrode assembly, so that the electrode assembly can be prevented from being damaged by the support body.

In a second aspect, the present application provides a battery including the battery cell of the above embodiment.

In a third aspect, the present application provides an electric device, which includes the battery in the above embodiments, wherein the battery is used for providing electric energy.

The foregoing description is only an overview of the technical solutions of the present application, and the present application can be implemented according to the content of the description in order to make the technical means of the present application more clearly understood, and the following detailed description of the present application is given in order to make the above and other objects, features, and advantages of the present application more clearly understandable.

Drawings

Various additional advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Moreover, like reference numerals are used to refer to like elements throughout. In the drawings:

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

FIG. 2 is an exploded schematic view of a battery in some embodiments of the present application;

fig. 3 is an exploded view of a battery cell in some embodiments of the present application;

fig. 4 is a front view of the battery cell shown in fig. 3;

fig. 5 is a side view of the battery cell shown in fig. 3;

FIG. 6 is an end view at A-A of FIG. 5;

FIG. 7 is an enlarged view at B in FIG. 6;

FIG. 8 is a schematic view of the structure of FIG. 6 with the support body removed;

fig. 9 is a schematic structural view of a support body of the battery cell shown in fig. 3;

fig. 10 is a schematic structural view of a support body of a battery cell in another embodiment of the present application;

fig. 11 is a schematic view of an internal structure of a battery cell in another embodiment of the present application;

fig. 12 is a schematic structural view of a support body of the battery cell shown in fig. 11.

The reference numbers in the detailed description are as follows:

1000. a vehicle; 100. a battery; 200. a controller; 300. a motor; 10. a box body; 11. a first portion; 12. a second portion; 20. a battery cell; 21. an end cap; 21a, electrode terminals; 22. a housing; 22a, a first wall portion; 22b, a second wall portion; 22c, corners; 23. an electrode assembly; 23a, a bending part; 23b, a straight portion; 24. a support body; 24a, a first surface; 24b, a second surface; 24c, a sub-support; 25. an insulating film; q, an accommodating space; K. a vacant space; x, a first direction; y, a second direction; z, height direction.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

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 "including" and "having," and any variations thereof in the description and claims of this application and the description of the figures above, are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary-secondary relationship of the technical features indicated. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase 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. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two sets), "plural pieces" refers to two or more (including two pieces).

In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length"

Width, thickness, up, down, front, back, left, right, vertical, horizontal and top "

The references to "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are based on the orientation or positional relationship shown in the drawings and are intended only to facilitate description of the embodiments and to simplify the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed or operated in a particular 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 otherwise explicitly specified or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

The battery cell generally includes a case and an electrode assembly disposed in the case, wherein the electrode assembly is a component formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet and capable of performing an electrochemical reaction. With the increasing requirements of the industry on the energy density of the battery, the thinner the shell thickness of the battery cell is, so that the tensile strength of the shell is lower.

The inventor notices that the battery monomer can sequentially pass through a primary liquid injection process, a formation process, a secondary liquid injection process, a nitrogen return process, sealing nail welding and the like in the preparation process, the battery monomer is respectively in a vacuum state and a negative pressure state in the primary liquid injection stage and the formation stage, and the side surface of the shell is easy to indent and deform under the action of pressure difference. Certain positive pressure nitrogen gas can be filled into the battery single body in the nitrogen returning process to improve the concave phenomenon of the shell, but in the subsequent sealing nail welding process, the shell can be concave to a certain degree due to the influence of welding temperature. The side flatness of the shell is easy to exceed the specification when the shell is recessed, and poor glue pressing can occur between the shell and the shell when a battery monomer is assembled to form a battery module, so that the safety problem of a battery is easily caused.

Based on the above consideration, in order to solve the safety problem of the battery caused by poor uniformity of the flatness of the side surface of the housing of the battery cell, through intensive research, the inventor designs a battery cell, wherein a support body is arranged between the housing of the battery cell and the bending part of the electrode assembly, and the support body is supported between the housing and the bending part of the electrode assembly, so that the housing can be prevented from being deformed inwards towards the electrode assembly, the flatness of the side surface of the housing can be maintained, and the safety problem caused by poor glue pressing between the housings can be avoided.

The battery cell disclosed in the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but not limited thereto. A power supply system including the electric device composed of the battery cell, the battery, and the like disclosed in the present application may be used. The powered device may be, but is not limited to, a cell phone, tablet, laptop, electronic toy, electric tool, battery car, electric car, ship, spacecraft, and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electric device according to an embodiment of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or a range-extended automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000. Vehicle 1000 may also include a controller 200 and a motor 300, controller 200 being configured to control battery 100 to power motor 300, for example, for start-up, navigation, and operational power requirements while traveling of vehicle 1000.

In some embodiments of the present application, the battery 100 may not only serve as an operating power source of the vehicle 1000, but also serve as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas to provide driving power for the vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide a receiving space for the battery cell 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 cover each other, and the first portion 11 and the second portion 12 together define a receiving space for receiving the battery cell 20. The second part 12 may be a hollow structure with one open end, the first part 11 may be a plate-shaped structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a containing space; the first portion 11 and the second portion 12 may be both hollow structures with one side open, and the open side of the first portion 11 may cover the open side of the second portion 12. Of course, the case 10 formed by the first and second portions 11 and 12 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 100, the number of the battery cells 20 may be multiple, and the multiple battery cells 20 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the multiple battery cells 20. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery cells 20 is accommodated in the box body 10; of course, the battery 100 may also be formed by connecting a plurality of battery cells 20 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and the whole is accommodated in the box 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 20 may be cylindrical, flat, rectangular parallelepiped, or other shape.

Referring to fig. 3, fig. 3 is an exploded schematic view of a battery cell 20 according to some embodiments of the present disclosure. The battery cell 20 refers to the smallest unit constituting the battery. As shown in fig. 3, the battery cell 20 includes an end cap 21, a case 22, an electrode assembly 23, and other functional components.

The case 22 is formed with an opening at one side in the height direction Z thereof, and the end cap 21 is fitted to the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 may be adapted to the shape of the housing 22 to fit the housing 22. Alternatively, the end cap 21 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap 21 is not easily deformed when being impacted, and the battery cell 20 may have a higher structural strength and improved safety. The end cap 21 may be provided with functional components such as the electrode terminals 21 a. The electrode terminals 21a may be used to be electrically connected with the electrode assembly 23 for outputting or inputting electric energy of the battery cells 20. In some embodiments, the end cap 21 may further include a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in this embodiment. In some embodiments, insulation (not shown) may also be provided on the inside of the end cap 21, which may be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. Illustratively, the insulator may be plastic, rubber, or the like.

The case 22 is an assembly for mating with the end cap 21 to form an internal environment of the battery cell 20, wherein the formed internal environment may be used to house the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 may be separate components, and an opening may be provided in the housing 22, and the opening may be covered by the end cap 21 to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing 22 may be integrated, and specifically, the end cap 21 and the housing 22 may form a common connecting surface before other components are inserted into the housing, and when it is necessary to enclose the inside of the housing 22, the end cap 21 covers the housing 22. The housing 22 may be a variety of shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present invention is not limited thereto.

The electrode assembly 23 is a part in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 may be contained within the case 22. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive and negative electrode tabs having the active material constitute the body portions of the electrode assembly, and the portions of the positive and negative electrode tabs having no active material each constitute a tab. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs are connected with the electrode terminals to form a current loop.

According to some embodiments of the present disclosure, referring to fig. 3 to 6, the present disclosure provides a battery cell 20 including a case 22, an electrode assembly 23, and a support body 24, wherein the electrode assembly 23 is accommodated in the case 22, the electrode assembly 23 includes a straight portion 23b and bending portions 23a located at two sides of the straight portion 23b, the support body 24 is located between an outer surface of the bending portion 23a and an inner wall of the case 22 along a first direction X, the support body 24 is configured to prevent the case 22 from being recessed toward the electrode assembly 23, and the first direction X is a direction in which the straight portion 23b and the bending portions 23a are arranged side by side.

The case 22 refers to a component having a certain space formed therein to accommodate the electrode assembly 23. The housing 22 may be, but not limited to, a member having an opening at one end in the height direction Z, and the opening is covered by the end cap 21 to form the internal environment of the battery cell 20. Reference may be made to the above description for the housing 22.

The electrode assembly 23 is a part in which electrochemical reactions occur in the battery cell 20. The structure of the electrode assembly 23 can be referred to the above description, and details thereof are omitted. The number of the electrode assemblies 23 is not limited.

The electrode assembly 23 includes a straight portion 23b and bent portions 23a, the bent portions 23a being located at both sides of the straight portion 23b in the first direction X. The straight portion 23b is a portion of the electrode assembly 23 in which the outer surface is planar, and the bent portion 23a is a portion of the electrode assembly 23 in which the outer surface is non-planar.

In general, when the electrode assembly 23 is in a winding type structure, the straight portion 23b corresponds to a portion of the electrode assembly 23 that is arranged straight, and the bent portion 23a corresponds to a portion of the electrode assembly 23 where winding is reversed, the first direction X corresponding to a winding direction. Of course, the form of the folded portion 23a is not limited to the winding form, and the folded portion 23a formed in other cases is also applicable to the present application, and is not limited herein.

When the electrode assembly 23 is placed in the case 22, a spacing space is formed at a spacing between an inner wall (defined as a first wall portion 22 a) of the case 22 facing the bent portion 23a of the electrode assembly 23 and the bent portion 23a, and an inner wall (defined as a second wall portion 22 b) of the case 22 facing the flat portion 23b of the electrode assembly 23 and an outer surface of the flat portion 23b may be in large-area contact without the spacing space.

Since a space exists between the bent portion 23a and the first wall portion 22a of the housing 22, the housing 22 may be recessed into the space, which affects the flatness of the first wall portion 22 a. Since the flat portion 23b can make a large-area contact with the second wall portion 22b of the housing 22, the housing 22 is hindered from being recessed toward the flat portion 23b to some extent by the flat portion 23 b.

The support body 24 is arranged between the outer surface of the bent portion 23a and the inner wall of the housing 22, i.e., within the above-described interval space, in the first direction X. The support 24 is provided in the space and can spread the case 22 and the electrode assembly 23 apart from each other to prevent the case 22 from being deformed toward the electrode assembly 23. The support body 24 is in the form of a support block, a support sheet, a support plate, and the like, particularly, without limitation.

The support body 24 blocks a deformation path of the case 22 depressed toward the electrode assembly 23, i.e., the support body 24 can block the case 22 from being concavely deformed. Reference herein to an obstruction includes a complete obstruction and an incomplete obstruction.

The complete obstruction means that the supporting body 24 does not substantially allow the housing 22 to be deformed inwards, for example, when the supporting body 24 is made of a hard material, the supporting body 24 can substantially obstruct the housing 22 from being deformed inwards due to its high hardness (for example, the supporting body 24 is made of ceramic or metal, etc. to form a supporting block); in another example, the supporting body 24 is an elastic body with a large deformation resistance, and the elastic body has a large rigidity, and can be designed to resist the concave force of the casing 22 without deformation.

The incomplete hindrance includes the support 24 allowing some degree of concave deformation of the housing 22 (e.g., the support 24 is a support made of plastic), but when the force generated by the temperature/pressure difference between the inside and outside of the battery cell 20 applied to the housing 22 is removed, the support 24 causes the housing 22 to deform reversely under its own restoring force to relieve the deformation of the housing 22, e.g., the support 24 is a less rigid spring.

Of course, it can be understood that, since the supporting body 24 is located between the case 22 and the bending portion 23a of the electrode assembly 23, regardless of the material of the supporting body 24, the space occupied by itself reduces the concave deformation space of the case 22 to a certain extent, that is, the concave deformation degree of the case 22 can be relieved to a certain extent, and the concave deformation of the case 22 is hindered to a certain extent.

It should be noted that the supporting body 24 is not limited to be deformed completely by the internal concave force of the casing 22, that is, the casing 22 is not limited to be deformed completely by the internal and external temperature/pressure difference of the battery cell 20, as long as the internal concave degree is within the design range.

When the housing 22 tends to recess under the influence of the pressure difference between the inside and the outside of the battery cell 20 or the temperature, the housing 20 is blocked by the support 24 to resist the recessed deformation, so that the recessed degree of the housing 22 is greatly reduced, and the side surface of the housing 22 can maintain a good flatness. When the single batteries 20 form a battery 100 module, the side flatness of the shell 22 is good, and the glue pressing between the shells 22 of the single batteries 20 is good, so that the safety problem caused by poor glue pressing can be avoided.

In some embodiments, the support body 24 has a hardness greater than that of the electrode assembly 23.

The hardness of the support body 24 and the electrode assembly 23 may be compared based on, but not limited to, rockwell hardness. Specifically, the Rockwell hardness measurement method can be executed by referring to the national standards GB/T230.1-2018 metal Rockwell hardness test, GB/T3398.2-2008 Plastic hardness determination-Rockwell hardness test and the like.

The support body 24 may be a metal, ceramic, or plastic, and is not particularly limited as long as it has a hardness greater than that of the electrode assembly 23.

The support body 24 may be made of a high molecular polymer material. First, the high molecular polymer material has a small mass, and the weight of the battery cell 20 can be reduced. Secondly, the high molecular polymer material is not easy to react with the electrolyte inside the battery cell 20, does not absorb the electrolyte easily, and has good insulation property, thereby not easily affecting the performance of the battery cell 20. The casing 22 is generally made of an aluminum shell, and when the supporting body 24 is made of a high polymer material, the hardness thereof is lower than that of the casing 22, so that the casing 22 can be prevented from being scratched.

Further, the support body 24 may be made of any one of polyethylene, polyethylene terephthalate, and polypropylene. Polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP) are widely used as materials of the insulating film 25 and the separator in the battery cell 20, and have better electrical insulation, so that compared with other materials that are not applied inside the battery cell 20, the probability of unknown risks occurring in the battery cell 20 can be reduced, and the safety of the battery cell 20 can be ensured.

The support body 24 has a hardness higher than that of the electrode assembly 23, and when the case 22 is recessed, the support body 24 can absorb or resist most of the deformation force of the recess of the case 22, and can provide strong support for the case 22 to resist the recessed deformation of the case 22, so that the forced deformation of the electrode assembly 23 can be relieved, and the electrode assembly 23 can be protected.

In some embodiments, referring to fig. 6, 7 and 9, the first surface 24a of the support body 24 facing the electrode assembly 23 is formed in a curved surface corresponding to the shape of the outer surface of the bent portion 23 a.

The outer surface of the bent portion 23a is a curved surface, and may be, but is not limited to, a curved surface. When the electrode assembly 23 is in a winding structure, the bent portion 23a corresponds to a portion of the electrode assembly 23 where the arc is reversed, and the outer surface of the bent portion 23a is an arc surface.

The first surface 24a of the support body 24 and the outer surface of the bent portion 23a are curved surfaces adapted to each other, and the first surface 24a can make large-surface contact with the bent portion 23 a. When the case 22 is recessed, the support body 24 supports the electrode assembly 23 against the recess of the case 22, and when the first surface 24a contacts with the large outer surface of the bent portion 23a, the reaction force of the support body 24 on the bent portion 23a is uniform, which helps to prevent the electrode assembly 23 from being damaged due to local deformation of the bent portion 23 a.

In some embodiments, referring to fig. 6, 9 and 10, in the first direction X, the second surface 24b of the support 24 facing the housing 22 is located between the inner wall of the housing 22 and the outer surface of the bent portion 23a facing the housing 22.

The second surface 24b may be configured to fit the shape of the opposing inner wall of the housing 22. Typically, the inner wall of the housing 22 is planar and the second surface 24b is correspondingly planar.

In the first direction X, the second surface 24b is located between the outer surface of the bent portion 23a and the inner wall of the housing 22, i.e., the second surface 24b is closer to the inner wall of the housing 22 than the bent portion 23 a. At this time, the spaced distance between the bent portion 23a and the case 22 includes a distance between the bent portion 23a and the second surface 24b and a distance between the second surface 24b and the case 22.

At this time, the support body 24 has a large thickness in the first direction X, and can have a good strength, thereby effectively preventing the housing 22 from being recessed. Meanwhile, the support body 24 may surround the outer surface of the bent portion 23a, which may provide better protection for the electrode assembly 23.

In other embodiments, referring to fig. 11 and 12, in the first direction X, the outer surface of the bent portion 23a facing the housing 22 is flush with the second surface 24b of the supporting body 24 facing the housing 22.

The second surface 24b is flush with the outer surface of the bent portion 23a, which means that the minimum distance from the bent portion 23a to the housing 22 in the first direction X is equal to the distance from the second surface 24b to the housing 22. Specifically, the second surface 24b is flush with a portion of the bent portion 23a closest to the housing 22 in the first direction X. In the embodiment shown in fig. 11, the outer surface of the bent portion 23a is a circular arc surface, and the second surface 24b is tangent to the circular arc surface of the bent portion 23 a.

Incidentally, when the battery cell 20 includes a plurality of electrode assemblies 23, the bent portions 23a of the respective electrode assemblies 23 may be disposed to be all flush with the second surface 24b of the support body 24. At this time, the support body 24 may have a configuration as shown in fig. 12, and the second surface 24b is a plane.

When the second surface 24b of the support body 24 is flush with the outer surface of the bent portion 23a in the first direction X, the bent portion 23a may directly abut against the housing 22 or be disposed at a shorter interval, so that the size of the battery cell 20 may be reduced and the energy density of the battery cell 20 may be increased.

In some embodiments, referring to fig. 5, 6 and 11, the battery cell 20 includes at least two electrode assemblies 23, all the electrode assemblies 23 are sequentially stacked along a second direction Y, which is a thickness direction of the electrode assemblies 23.

The straight portions 23b of the respective electrode assemblies 23 are stacked and connected in the second direction Y, and the bent portions 23a of the respective electrode assemblies 23 are spaced apart from the case 22 to form spaced spaces, and the support body 24 is disposed in each of the spaced spaces. The width direction of the housing 22 (parallel to the first direction X), the height direction Z of the housing 22, and the thickness direction of the housing 22 (parallel to the second direction Y) intersect with each other spatially. In general, the same electrode assembly 23 is used for the same battery cell 20, the electrodes formed by all the electrode assemblies 23 are spaced from the case 22 in the width direction as a whole, and the electrode assemblies 23 are reasonably arranged in a manner that the electrode assemblies 23 in all the electrode assemblies 23 are spaced from the case 22 in the width direction of the case 22.

The electrode assembly 23 is a main site where electrochemical reactions occur in the battery cell 20, and when the electrode assembly 23 includes at least two, the capacity of the battery cell 20 is large, which can improve the endurance of the battery 100. The bent portion 23a of each electrode assembly 23 is spaced from the case 22 in the width direction of the case 22, facilitating the assembly of the electrode assembly 23 as a whole into the case 22.

Meanwhile, providing the support 24 between the bent portion 23a of the electrode assembly 23 and the case 22 can greatly alleviate or even avoid the case 22 from being recessed, and particularly, for a battery cell 20 in which a plurality of wound electrode assemblies 23 are stacked, can greatly alleviate the degree of recess of the portion of the case 22 opposite to the arc-shaped outer surface of the bent portion 23a of the electrode assembly 23, which helps to maintain the side flatness of the portion of the case 22.

In some embodiments, referring to fig. 6 and 11, along the first direction X, the projection of the support body 24 and the projection of any one of the electrode assemblies 23 have an overlapping region.

The projection of the support 24 in the first direction X and the projection of any one of the electrode assemblies 23 have an overlapping region, all projections of each electrode assembly 23 may be located within the projection range of the support 24, or part projections of each electrode assembly 23 may be located within the projection range of the support 24.

When the projection of the support 24 in the first direction X and the projection of any one of the electrode assemblies 23 have an overlapping region, it is indicated that the support 24 is disposed between the bending portion 23a of each of the electrode assemblies 23 and the case 22, so that the support 24 can prevent the case 22 from recessing toward any one of the electrode assemblies 23, and ensure the flatness of the case 22 at all positions.

In some embodiments, referring to fig. 6 and 11, along the second direction Y, the projection of the supporting body 24 in the first direction X does not exceed the projection of the outermost electrode assembly 23 in the first direction X.

In the embodiment shown in fig. 6 and 11, the housing 22 is a square housing 22. When the housing 22 is a square housing 22, the inner wall of the housing 22 includes two first wall portions 22a and two second wall portions 22b connected to each other, the two first wall portions 22a are disposed oppositely along the first direction X, and the two second wall portions 22b are disposed oppositely along the second direction Y. The first wall portion 22a and the second wall portion 22b intersect to form a corner 22c, and when the case 22 is a square case 22, 4 corners 22c are formed. The case 22 at the corner 22c has a good structural strength and is not easily dented by the internal and external temperature/pressure difference of the battery cell 20.

When the projection of the support body 24 in the first direction X does not exceed the projection of the outermost electrode assembly 23 in the first direction X along the second direction Y, empty spaces K are formed between the bent portions 23a and the adjacent corners 22c of the outermost electrode assemblies 23 in the second direction Y among all the electrode assemblies 23. The empty space K is a space in an empty state, and is mainly a space in an empty state without accommodating the support body 24.

Since the corner 22c of the case 22 has high structural strength and is not easy to recess under the internal and external temperature/pressure difference of the battery cell 20, the empty space K is formed between the outermost electrode assembly 23 and the corner 22c without the support 24, so that the cost for disposing the support 24 can be reduced.

Of course, in other embodiments, the supporting body 24 may be disposed in the empty space K, and in this case, along the second direction Y, the projection of the supporting body 24 in the first direction X may exceed the projection of the outermost electrode assembly 23 in the first direction X.

In some embodiments, referring to fig. 8, 6 and 11, the supporting body 24 includes at least one sub-supporting body 24c, and the sub-supporting body 24c is disposed in the accommodating space Q between each two connected bent portions 23a and the housing 22 in the second direction Y.

In the embodiment shown in fig. 8, the outer surface of the bent portion 23a is a circular arc surface, and the outer surface of the bent portion 23a of each electrode assembly 23 has portions which are opposite and spaced from each other in the second direction Y and form the respective receiving spaces Q together with the case 22.

Each receiving space Q is provided with a sub-support 24c. Each sub-support 24c is configured to block the housing 22 from being recessed into the housing space Q. The sub-supports 24c may be made of a metal material, a polymer material, or the like, and the hardness of all the sub-supports 24c may be greater than that of the electrode assembly 23.

When the case 22 is recessed, each sub-support 24 can apply force to the bending portion 23a of the two electrode assemblies 23 forming the accommodating space Q, and prevent the recessed deformation of the case 22, which means that the force applied to each electrode assembly 23 is equally divided, and the electrode assemblies 23 are less stressed and safer.

In some embodiments, the support body 24 includes a plurality of sub-support bodies 24c, and the sub-support bodies 24c are sequentially connected in the second direction Y.

The sub-supports 24c may be provided separately from each other (as shown in fig. 9) or may be provided integrally with each other (as shown in fig. 10). When the sub-supports 24c are provided separately, they may be connected by means of contact, adhesion, or the like.

At this time, the sub-supports 24c are connected to form a whole, and the concave deformation of the case 22 is resisted by the mutual force, and the concave force of the case 22 received by one sub-support 24c is dispersed to other sub-supports 24c by the sub-supports 24c, so that the acting force applied to the electrode assemblies 23 can be dispersed, which is helpful for improving the protection of the electrode assemblies 23.

In some embodiments, referring to fig. 3 to 6, the battery cell 20 further includes an insulating film 25, the insulating film 25 being located between the electrode assembly 23 and the case 22, the insulating film 25 serving to insulate and separate the electrode assembly 23 from the case 22.

The insulating film 25 is an electrically insulating member such as polyethylene, polyethylene terephthalate, or polypropylene. The insulating film 25 may be made of the same material as the support 24.

In general, case 22 is a metal case 22 (e.g., an aluminum case), and when electrode assembly 23 is in direct contact with case 22, leakage of electricity is easily caused, and case 22 and electrode assembly 23 are electrically insulated by insulating film 25, so that leakage of electricity from case 22 is prevented.

In some embodiments, referring to fig. 6, the support 24 is positioned between the electrode assembly 23 and the insulating film 25.

The support body 24 is disposed in a space between the insulating film 25 and the electrode assembly 23. At this time, the support body 24 may be connected to the insulating film 25 to achieve the mounting and fixing (e.g., adhered to the insulating film 25, or adhered to the electrode assembly 23 to achieve the mounting and fixing), of course, the support body 24 may be sandwiched between the insulating film 25 and the electrode assembly 23 to maintain the self-fixing or fixed in other manners (e.g., fixed to the bottom of the case 22).

The insulating film 25 is a film layer, the thickness of the film layer is thin, when the shell 22 is concave, the insulating film layer can be concave along with the shell 22, and at the moment, the support body 24 blocks the concave deformation of the shell 22 by blocking the concave of the insulating film 25.

In other embodiments, the support 24 is located between the insulating film 25 and the housing 22.

The support 24 is disposed in a space between the insulating film 25 and the case 22. In this case, the support 24 may be connected to the insulating film 25 for mounting and fixing (e.g., adhered to the insulating film 25), or may be adhered to the housing 22. Of course, the support 24 may be sandwiched between the insulating film 25 and the case 22 to be fixed to itself.

At this time, the support 24 is located outside the insulating film 25 and does not directly contact the electrode assembly 23, so that damage to the electrode assembly 23 by the support 24 can be avoided.

Specifically, in some embodiments, the insulating film 25 is attached to the bent portion 23a of the electrode assembly 23 facing the bent portion 23a, and the support 24 is attached to the insulating film 25.

At this time, the electrode assembly 23 can provide better support for the supporting body 24 through the insulating film 25, so as to avoid that the easily deformable insulating film 25 cannot provide strong support for the supporting body 24 and cannot effectively block the concave deformation of the casing 22, and ensure that the supporting body 24 can effectively block the concave deformation of the casing 22.

Generally, the concave deformation of the shell 22 is represented by its flatness, which represents the depth of the depression of the shell 22. Table 1 shows the flatness of the housing 22 after the formation stage of the battery cell 20 and the common battery cell provided in the embodiment of the present application.

TABLE 1

Group of	Mean flatness/mm	Flatness maximum value/mm	Uniformity (alpha)
				Reference group	-0.5	-1.1	0.18
Test group	-0.4	-0.6	0.08

In table 1, the reference group is a general battery cell, and the test group is the battery cell 20 provided in the examples of the present application. As can be seen from table 1, the average flatness value of the case 22 of the battery cell 20 provided in the embodiments of the present application is lower than that of the case of the general battery cell, the flatness value of the former is lower than that of the latter, and the flatness uniformity of the former is higher than that of the latter.

In the embodiment of the present application, the support 24 is disposed between the bent portion 23a of the electrode assembly 23 and the case 22 to prevent the case 22 from being recessed, and the flatness of the case 22 can be maintained between-0.6 mm and 0mm after the formation stage, that is, the recessed depth of the case 22 is not more than 0.6mm at most, and the flatness of the case 22 has good consistency.

In an embodiment of the present disclosure, the battery cell 20 includes a case 22, a support body 24, and at least two electrode assemblies 23, each electrode assembly 23 includes a straight portion 23b and a bent portion 23a arranged along a first direction X, all the electrode assemblies 23 are sequentially stacked along a second direction Y perpendicular to the first direction X, an accommodating space Q is formed between an outer surface of each of two adjacent bent portions 23a along the second direction Y and the case 22, the support body 24 includes a sub-support body 24c disposed in each accommodating space Q, and a first surface 24a of each sub-support body 24c is attached to a corresponding outer surface. All the sub-supports 24c are connected in sequence in the second direction Y. The case 22 can be prevented from being concavely deformed toward the electrode assembly 23 via the respective sub-supports 24c.

On the other hand, the embodiment of the present application further provides a battery 100, which includes the battery cell 20.

On the other hand, the embodiment of the present application further provides an electric device, which includes the above battery 100, where the battery 100 is used to provide electric energy.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is specific and detailed, but not construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent application shall be subject to the appended claims.

Claims (15)

1. A battery cell, comprising:

a housing;

an electrode assembly received in the case, the electrode assembly including a straight portion and bending portions at both sides of the straight portion;

a support located between an outer surface of the bending portion and an inner wall of the case along a first direction, the support configured to block the case from being depressed toward the electrode assembly, the first direction being a direction in which the straight portion and the bending portion are disposed side by side.

2. The battery cell according to claim 1, wherein the support body has a hardness greater than a hardness of the electrode assembly.

3. The battery cell according to claim 1, wherein a first surface of the support body facing the electrode assembly is formed to be curved corresponding to the shape of the outer surface of the bent portion.

4. The battery cell as recited in claim 1, wherein in the first direction, a second surface of the support body facing the housing is located between an inner wall of the housing and an outer surface of the bent portion facing the housing.

5. The battery cell as recited in claim 1, wherein in the first direction, an outer surface of the bent portion facing the housing is flush with a second surface of the support body facing the housing.

6. The battery cell according to any one of claims 1-5, comprising at least two of the electrode assemblies, all of which are sequentially stacked in a second direction, the second direction being a thickness direction of the electrode assemblies.

7. The battery cell according to claim 6, wherein along the first direction, a projection of the support body and a projection of any one of the electrode assemblies each have an overlapping region.

8. The battery cell as recited in claim 7, wherein along the second direction, a projection of the support body in the first direction does not exceed a projection of the outermost electrode assembly in the first direction.

9. The battery cell according to claim 6, wherein the support body comprises at least one sub-support body,

in the second direction, the accommodating space between each two adjacent bending parts and the shell is internally provided with one sub-support body.

10. The battery cell according to claim 9, wherein the support body comprises a plurality of the sub-support bodies, and each of the sub-support bodies is connected in sequence in the second direction.

11. The battery cell as recited in claim 1 further comprising an insulating film between the electrode assembly and the housing, the insulating film serving to insulate and isolate the electrode assembly from the housing.

12. The battery cell according to claim 11, wherein the support body is located between the electrode assembly and the insulating film.

13. The battery cell as recited in claim 11 wherein the support is located between the insulating film and the housing.

14. A battery comprising a cell according to any one of claims 1 to 13.

15. An electrical device comprising a battery according to claim 14 for providing electrical energy.

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