CN217134495U

CN217134495U - Battery and electric device

Info

Publication number: CN217134495U
Application number: CN202220832195.6U
Authority: CN
Inventors: 张涛; 何建福; 刘倩; 崔陈; 孙雪阳; 叶永煌
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-04-12
Filing date: 2022-04-12
Publication date: 2022-08-05
Anticipated expiration: 2032-04-12

Abstract

The application discloses a battery and a power consumption device. The battery of the embodiment of the application comprises a first battery cell and a second battery cell which are arranged along a first direction, wherein each of the first battery cell and the second battery cell comprises a shell and an electrode assembly accommodated in the shell. The first battery cell also includes a buffer member housed within the case, at least a portion of the buffer member overlapping the electrode assembly in the first direction, the buffer member configured to compress when the electrode assembly expands. The buffer member is not disposed in the case of the second battery cell. The first battery cell with the buffer parts arranged therein and the second battery cell without the buffer parts are mixed and stacked, the buffer parts of the first battery cell not only can provide space for expansion of the electrode assembly of the first battery cell through compression, but also can provide space for expansion of the electrode assembly of the second battery cell through compression, so that the expansion force increment of the battery is reduced, and the cycle performance of the first battery cell and the cycle performance of the second battery cell are improved.

Description

Battery and electric device

Technical Field

The present application relates to the field of batteries, and more particularly, to a battery and a power consumption device.

Background

The battery cell is widely used in electronic devices such as a mobile phone, a notebook computer, a battery car, an electric airplane, an electric ship, an electric toy car, an electric toy ship, an electric toy airplane, an electric tool, and the like. The battery monomer can comprise a cadmium-nickel battery monomer, a hydrogen-nickel battery monomer, a lithium ion battery monomer, a secondary alkaline zinc-manganese battery monomer and the like.

In the development of battery technology, how to improve the cycle performance of a battery cell is an important research direction in battery technology.

SUMMERY OF THE UTILITY MODEL

Provided are a battery and a power consumption device, which can improve cycle performance.

In a first aspect, the present application provides a battery including a first battery cell and a second battery cell arranged in a first direction, each of the first battery cell and the second battery cell including a case and an electrode assembly received in the case. The first battery cell also includes a buffer housed within the case, at least a portion of the buffer overlapping the electrode assembly in the first direction, the buffer configured to compress when the electrode assembly expands. The buffer member is not disposed in the case of the second battery cell.

In the technical scheme, the first battery cell with the built-in buffer piece and the second battery cell without the buffer piece are mixed and stacked, the buffer piece of the first battery cell not only can provide a space for the expansion of the electrode assembly of the first battery cell through compression, but also can provide a space for the expansion of the electrode assembly of the second battery cell through compression, so that the expansion amount of the expansion force of the battery is reduced, the risk that the battery fails in structure due to the fact that the battery cannot bear large expansion force is reduced, meanwhile, the cycle performance of the first battery cell and the cycle performance of the second battery cell are improved, and the compressible space of the buffer piece is fully utilized. This application embodiment only sets up the bolster in partial battery monomer, can save the quantity of bolster, improves the energy density of battery, increases the holistic structural strength of battery, improves the stability and the security of battery.

In some embodiments, a battery includes at least one battery module including a plurality of first battery cells and a plurality of second battery cells stacked in a first direction.

In some embodiments, in the battery module, a second battery cell is disposed between any adjacent two first battery cells.

In the technical scheme, two adjacent first battery cells can provide a space for the expansion of the second battery cell between the two first battery cells so as to reduce the expansion force of the second battery cell and improve the cycle performance of the second battery cell. The second battery cell separates adjacent first battery cells to reduce waste of compressible space of the buffer. The inside bolster that does not set up of second battery monomer, its structural strength is higher, sets up second battery monomer between adjacent first battery monomer, can guarantee the pressure between the adjacent battery monomer, reduces the risk of battery monomer skew when receiving external shock.

In some embodiments, in the battery module, the first battery cells and the second battery cells are alternately arranged in the first direction.

In the above technical solution, each first battery cell may provide a space for the expansion of the second battery cell adjacent thereto, so as to reduce the expansion force of the second battery cell, and improve the cycle performance of the first battery cell and the cycle performance of the second battery cell.

In some embodiments, the battery module includes a first battery pack and a second battery pack arranged in a first direction, the first battery pack includes a plurality of first battery cells sequentially stacked in the first direction, and the second battery pack includes a plurality of second battery cells sequentially stacked in the first direction.

The first battery cell and the second battery cell are different, and the battery management system needs to adopt different control modes for the first battery cell and the second battery cell. According to the technical scheme, the plurality of first battery monomers are arranged in groups, the plurality of second battery monomers are arranged in groups, and the difficulty of the battery management system for managing the first battery monomers and the second battery monomers can be reduced.

In some embodiments, the plurality of first battery stacks and the plurality of second battery stacks are alternately arranged in the first direction.

In the above technical solution, each first battery pack may provide a space for expansion of a plurality of second battery cells of the second battery pack adjacent thereto, so as to reduce an expansion force of the second battery cells, and improve cycle performance of the first battery cells and cycle performance of the second battery cells.

In some embodiments, the battery module is provided in plurality, and the plurality of battery modules are arranged in a second direction, the first direction being perpendicular to the second direction. The first battery cells of the adjacent battery modules are arranged in a staggered manner in the first direction.

In the technical scheme, the battery cells adjacent to the first battery cells are the second battery cells, so that the buffer parts of the first battery cells can provide space for expansion of the second battery cells through compression, the utilization rate of the compressible space of the buffer parts is improved, stress concentration is reduced, and the cycle performance of the first battery cells and the cycle performance of the second battery cells are improved.

In some embodiments, both ends of the battery module in the first direction are provided as the second battery cell.

In the above technical solution, in the battery module, the expansion force may be concentrated toward the middle of the battery module, and correspondingly, the expansion forces at the two ends of the battery module are relatively small, so that the second battery cells may be disposed at the two ends of the battery module along the first direction.

In some embodiments, the number of the first battery cells is m, the number of the second battery cells is n, and both m and n are positive integers greater than 0. m and n satisfy: m/(m + n) is more than or equal to 0.2 and less than or equal to 0.95.

The greater the number of the first battery cells, the greater the expansion that the buffer member can absorb, and the smaller the expansion force that the first battery cell and the second battery cell are subjected to. Of course, the larger the number of the first battery cells, the larger the volume and weight of the buffer member, the smaller the energy density of the battery, and the lower the structural strength of the entire battery. The technical scheme limits the value of m/(m + n) to 0.2-0.95, and also balances the cycle performance and the energy density of the battery.

In some embodiments, the first battery cell has a capacity of C1, the second battery cell has a capacity of C2, and C1 and C2 satisfy: C1/C2 is more than or equal to 0.7 and less than or equal to 1.

When the capacity difference between the first battery cell and the second battery cell is too large, the charge/discharge cutoff condition is limited by the small-capacity battery cell, so that part of the capacity of the large-capacity battery cell is not released, and the capacity actually exerted by the battery is slightly small. The technical scheme limits the value of C1/C2 to 0.7-1 so as to reduce the capacity difference caused by the buffer parts and improve the performance of the battery.

In some embodiments, the shape of the first battery cell is the same as the shape of the second battery cell, so that the difficulty of stacking the first battery cell and the second battery cell is reduced, and the assembly process is simplified.

In a second aspect, the present application provides an electric device, which includes the battery of any embodiment of the first aspect, wherein the battery is used for providing electric energy.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying 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 provided in accordance with some embodiments of the present application;

fig. 3 is a simplified schematic diagram of a battery provided in accordance with some embodiments of the present application;

fig. 4 is an exploded view of a first cell of a battery provided in accordance with some embodiments of the present application;

fig. 5 is a schematic cross-sectional view of a first cell of a battery provided by some embodiments of the present application;

fig. 6 is a schematic cross-sectional view of a second cell of a battery provided by some embodiments of the present application;

FIG. 7 is a simplified schematic diagram of a battery provided in accordance with further embodiments of the present application;

fig. 8 is a simplified schematic diagram of a battery provided in accordance with further embodiments of the present application.

The reference numerals for the specific embodiments are explained below:

1. a vehicle; 2. a battery; 3. a controller; 4. a motor; 5. a first battery cell; 6. a second battery cell;

10. an electrode assembly; 20. a housing; 21. a housing; 22. an end cap; 30. a buffer member; 40. an electrode terminal;

71. a first tank portion; 72. a second tank portion; 73. a seal member;

2a, a battery module; 2b, a first battery pack; 2c, a second battery pack;

x, a first direction; y, a second direction; z, third direction.

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

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of 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 in the description of the application in the present application 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. The terms "first," "second," and the like in the description and claims of this application or in the foregoing drawings are used for distinguishing between different elements and not for describing a particular sequential or chronological order.

Reference in the specification 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 specification. 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.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "attached" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

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

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

The appearances of "a plurality" in this application are intended to mean more than two (including two).

In this application, the battery cell may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, and the embodiment of the present application is not limited thereto. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application.

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

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive electrode piece, a negative electrode piece and a separator. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece comprises a positive current collector and a positive active substance layer, and the positive active substance layer is coated on the surface of the positive current collector; the positive pole mass flow body includes anodal coating district and connects in anodal utmost point ear in anodal coating district, and anodal coating district has anodal active substance layer, and anodal utmost point ear does not coat anodal active substance layer. Taking a lithium ion battery monomer as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece comprises a negative pole current collector and a negative pole active substance layer, and the negative pole active substance layer is coated on the surface of the negative pole current collector; the negative electrode current collector comprises a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area, wherein the negative electrode coating area is coated with a negative electrode active material layer, and the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector may be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon, silicon, or the like. The material of the spacer may be PP (polypropylene) or PE (polyethylene).

The battery cell further comprises a housing, and a containing cavity for containing the electrode assembly is formed inside the housing. The case may protect the electrode assembly from the outside to prevent foreign substances from outside from affecting the charge or discharge of the electrode assembly.

A battery is generally provided with a plurality of battery cells stacked in sequence to provide higher voltage and capacity to a power-using device. The battery cells expand during use, and the expansion of a plurality of stacked battery cells is superposed, so that a large expansion force is generated. Along with the increase of the expansion force, electrolyte between pole pieces of an electrode assembly of the battery cell can be extruded out, and the cycle performance of the electrode assembly is influenced; if the expansion force is too large, a risk of the battery cell being crushed may be caused.

In the related art, in order to reduce the swelling force generated from the battery cells during use, a buffer member is generally disposed between the adjacent battery cells. The buffer piece can compress when the battery monomer expands to provide space for the expansion of the battery monomer, reduce the bulging force that the battery monomer received. However, the inventor finds that the buffer member needs to be adhered to the battery cell during the assembly process of the battery, which needs to accurately position the gluing position on the battery cell and the installation position of the buffer member, and increases the assembly difficulty of the battery. The expansion of the battery monomer is a dynamic change process, namely the battery monomer expands when being charged and contracts when being discharged; along with whole battery live time increases, the compression resilience characteristic of bolster worsens, and the bolster can't in time kick-back when the battery monomer contracts, causes the clearance to appear between the adjacent battery monomer, has increased the risk that the battery became invalid when vibrations. In addition, the buffer part is continuously contracted and rebounded in the using process of the battery, so that the buffer part is easily deviated, and then the single battery is unevenly stressed, polarization occurs in the electrode assembly, and the performance of the electrode assembly is deteriorated.

The inventors found that the cause of the swelling of the battery cell is the swelling of the electrode assembly during the charging process. The inventors tried to mount the buffer member in the outer case of the battery cell such that the buffer member is compressed when being pressed by the electrode assembly during the cycling of the battery cell to provide a space for the expansion of the electrode assembly, reduce the pressure applied to the electrode assembly, reduce the expansion deformation of the battery cell, and improve the cycle life of the battery cell. In addition, install the bolster in the shell, can avoid the bolster to drop, reduce the risk of bolster skew dislocation. When a plurality of battery monomers are assembled into a group, a buffer piece is not required to be arranged between the battery monomers, so that the assembly process can be simplified, and the efficiency is improved.

The inventor further researches and discovers that the buffer member arranged in each battery unit of the battery can absorb the expansion amount exceeding the total expansion amount of the electrode assemblies of a plurality of battery units, so that the compressible space of part of the buffer member is wasted, and the buffer member has certain volume and weight, so that the energy density of the battery is low. In the battery, a plurality of battery cells need to be clamped so as to reduce the risk of dislocation of the battery cells when the battery cells are subjected to external impact; and because all set up the bolster in each battery monomer, this clamping force that probably causes the battery monomer to receive is on the low side, and the overall structure's of battery structural strength is not enough, causes the risk of battery monomer dislocation.

In view of the above, the inventor stacks the battery cell with the buffer member inside and the battery cell without the buffer member in a mixed manner, so as to improve the cycle performance of the battery cell, increase the energy density of the battery, and increase the structural strength of the whole battery under the condition that the expansion force meets the requirement.

The battery described in the embodiment of the present application is suitable for an electric device using the battery.

The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like; spacecraft include aircraft, rockets, space shuttles, spacecraft, and the like; electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric power tools include metal cutting electric power tools, grinding electric power tools, assembly electric power tools, and electric power tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not specifically limit the above power utilization device.

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

Fig. 1 is a schematic structural diagram of a vehicle according to some embodiments of the present application.

As shown in fig. 1, a battery 2 is provided inside a vehicle 1, and the battery 2 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 2 may be used for power supply of the vehicle 1, and for example, the battery 2 may serve as an operation power source of the vehicle 1.

The vehicle 1 may further comprise a controller 3 and a motor 4, the controller 3 being adapted to control the battery 2 to power the motor 4, e.g. for start-up, navigation and operational power demands while driving of the vehicle 1.

In some embodiments of the present application, the battery 2 may be used not only as an operating power source of the vehicle 1, but also as a driving power source of the vehicle 1, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1.

Fig. 2 is an exploded schematic view of a battery provided in accordance with some embodiments of the present application; fig. 3 is a simplified schematic diagram of a battery provided in accordance with some embodiments of the present application; fig. 4 is an exploded view of a first cell of a battery provided in accordance with some embodiments of the present application; fig. 5 is a schematic cross-sectional view of a first cell of a battery provided by some embodiments of the present application; fig. 6 is a schematic cross-sectional view of a second battery cell of a battery provided in some embodiments of the present application.

As shown in fig. 2 to 6, the battery 2 of the embodiment of the present application includes a first battery cell 5 and a second battery cell 6 arranged in a first direction X, and each of the first battery cell 5 and the second battery cell 6 includes a case 20 and an electrode assembly 10 accommodated in the case 20. The first battery cell 5 further includes a buffer member 30 accommodated in the case 20, at least a portion of the buffer member 30 overlapping the electrode assembly 10 in the first direction X, the buffer member 30 being configured to compress when the electrode assembly 10 expands. The buffer member 30 is not provided in the case 20 of the second battery cell 6.

The case 20 has a hollow structure, and an accommodating chamber for accommodating the electrode assembly 10 and an electrolyte is formed inside thereof. The housing 20 may be a variety of shapes, such as a rectangular parallelepiped, and the like. The shape of the case 20 may be determined according to the specific shape of the electrode assembly 10, for example, if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped case may be used.

In the present embodiment, the material of the housing 20 is not limited. For example, the housing 20 may be made of hard materials such as aluminum, steel, and plastic, or may be made of plastic-aluminum films, plastic-steel films, or other soft materials.

Electrode assembly 10 includes a first pole piece and a second pole piece, and electrode assembly 10 operates primarily by virtue of metal ions moving between the first pole piece and the second pole piece. Illustratively, the electrode assembly 10 further includes a separator for insulating and separating the first and second pole pieces. The polarity of the first pole piece is opposite to that of the second pole piece. Specifically. One of the first pole piece and the second pole piece is a positive pole piece, and the other is a negative pole piece.

In the first battery cell 5, the electrode assembly 10 may be one or a plurality of. Illustratively, the plurality of electrode assemblies 10 of the first battery cell 5 are stacked in the first direction X.

In the second battery cell 6, the electrode assembly 10 may be one or a plurality of. Illustratively, the plurality of electrode assemblies 10 of the second battery cell 6 are stacked in the first direction X.

The first battery cell 5 may be a ternary lithium battery cell, a lithium iron phosphate battery cell, a sodium ion battery cell, a lithium manganate battery cell, a lithium titanate battery cell, or other types of battery cells. The type of the second battery cell 6 may be the same as or different from the type of the first battery cell 5. Illustratively, the first battery cell 5 may be a ternary lithium battery cell, and the second battery cell 6 may be a lithium iron phosphate battery cell.

The first battery cell 5 and the second battery cell 6 may or may not have the same shape. For example, the size of the first battery cell 5 in the first direction X may be equal to, smaller than, or larger than the size of the second battery cell 6 in the first direction X.

In the first battery cell 5, there may be one or more buffering members 30, which is not limited in the embodiment of the present application.

The buffer member 30 may be compressed when pressed by the electrode assembly 10 to provide a space for expansion of the electrode assembly 10, reducing the force between the can 20 and the electrode assembly 10. Illustratively, the buffer member 30 has a certain elastic deformability, when the electrode assembly 10 is fully charged, the buffer member 30 can be compressed by the electrode assembly 10, and when the electrode assembly 10 is fully discharged, the buffer member 30 can recover at least partial deformation, so as to ensure that the buffer member 30 can abut against the electrode assembly 10, improve the uniformity of the stress distribution of the electrode assembly 10, and reduce the risk of wrinkles occurring on the pole pieces of the electrode assembly 10.

The specific material of the buffer member 30 is not limited in the embodiment of the present application, and it needs to have a certain ability to deform and recover at least part of the deformation when the external force is removed.

In the embodiment of the present application, the first battery cell 5 with the built-in buffer member 30 and the second battery cell 6 without the buffer member 30 are stacked in a mixed manner, the buffer member 30 of the first battery cell 5 can provide a space for the expansion of the electrode assembly 10 of the first battery cell 5 by compression, and can also provide a space for the expansion of the electrode assembly 10 of the second battery cell 6 by compression, so that the expansion amount of the battery is reduced, the risk of structural failure of the battery due to the fact that the battery cannot bear a large expansion force is reduced, the cycle performance of the first battery cell 5 and the cycle performance of the second battery cell 6 are improved, and the compressible space of the buffer member 30 is fully utilized. This application embodiment only sets up bolster 30 in partial battery monomer, can save the quantity of bolster 30, improves battery 2's energy density, increases the holistic structural strength of battery 2, improves battery 2's stability and security.

In some embodiments, the battery 2 further includes a case in which the first battery cell 5 and the second battery cell 6 are housed.

The case is used for accommodating the first battery cell 5 and the second battery cell 6, and the case may have various structures. In some embodiments, the box body may include a first box body portion 71 and a second box body portion 72, the first box body portion 71 and the second box body portion 72 cover each other, and the first box body portion 71 and the second box body portion 72 together define a receiving space for receiving the battery cell. The second tank part 72 may be a hollow structure with one open end, the first tank part 71 is a plate-shaped structure, and the first tank part 71 covers the open side of the second tank part 72 to form a tank body with an accommodating space; the first tank portion 71 and the second tank portion 72 may be hollow structures with one side open, and the open side of the first tank portion 71 may cover the open side of the second tank portion 72 to form a tank body with an accommodating space. Of course, the first tank portion 71 and the second tank portion 72 may be various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first tank 71 and the second tank 72 are connected, a sealing member 73, such as a sealant or a gasket, may be provided between the first tank 71 and the second tank 72.

Assuming that the first box portion 71 covers the top of the second box portion 72, the first box portion 71 may also be referred to as an upper box cover, and the second box portion 72 may also be referred to as a lower box body.

In some embodiments, the first battery cell 5 is provided in plurality, and the second battery cell 6 is provided in plurality. The plurality of first battery cells 5 and the plurality of second battery cells 6 may be connected in series, in parallel, or in series-parallel, where the plurality of first battery cells 5 and the plurality of second battery cells 6 are both connected in series or in parallel.

In some embodiments, the first battery cell 5 and the second battery cell 6 may be electrically connected by a bus member (not shown).

In some embodiments, the housing 20 includes a shell 21 and an end cap 22, the shell 21 having an opening, the end cap 22 covering the opening.

The housing 21 may be an open-sided structure, and the end caps 22 are disposed in one and cover the opening of the housing 21. Alternatively, the housing 21 may have a structure with two openings on two sides, and two end caps 22 are provided, and the two end caps 22 cover the two openings of the housing 21 respectively.

Illustratively, the end cap 22 is welded, bonded, snapped or otherwise attached to the housing 21.

In some embodiments, two electrode terminals 40 are disposed on the end cap 22, one electrode terminal 40 is used for electrical connection with a first pole piece of the electrode assembly 10, and the other electrode terminal 40 is used for electrical connection with a second pole piece, so as to lead out the electric energy generated by the electrode assembly 10 to the outside of the case 20.

In some embodiments, the buffer 30 may be a porous structure. The pores in the buffer member 30 may serve to store the electrolyte, and the electrolyte of the buffer member 30 may be squeezed out when the electrode assembly 10 expands and presses the buffer member 30.

In some embodiments, the bumper 30 may be made of foam.

In some embodiments, in the first battery cell 5, the buffer member 30 and the electrode assembly 10 are stacked in the first direction X. Illustratively, the buffer 30 is a flat plate structure. The flat plate structure is easily molded and can improve the uniformity of the stress distribution of the electrode assembly 10 when the electrode assembly 10 is expanded.

In some embodiments, the number of the first battery cells 5 is m, the number of the second battery cells 6 is n, and both m and n are positive integers greater than 0. m and n satisfy: m/(m + n) is more than or equal to 0.2 and less than or equal to 0.95.

The greater the number of the first battery cells 5, the greater the expansion that the cushion member 30 can absorb, and the smaller the expansion force that the first battery cell 5 and the second battery cell 6 receive. Of course, the greater the number of first battery cells 5, the greater the volume and weight of the buffer 30, the lower the energy density of the battery 2, and the lower the structural strength of the battery 2 as a whole. The inventors also balanced the cycle performance and energy density of the cell 2 by limiting the value of m/(m + n) to 0.2-0.95.

Alternatively, the value of m/(m + n) may be 0.2, 0.3, 0.5, 0.7, 0.8, 0.9, or 0.95.

In some embodiments, the capacity of the first battery cell 5 is C1, the capacity of the second battery cell 6 is C2, and C1 and C2 satisfy: C1/C2 is more than or equal to 0.7 and less than or equal to 1. The capacity refers to the amount of electricity stored in the battery cell.

When the capacity difference between the first battery cell 5 and the second battery cell 6 is too large, the charge/discharge cutoff condition is limited by the small-capacity battery cell, so that a part of the capacity of the large-capacity battery cell is not released, and the capacity actually exhibited by the battery 2 is small. In the embodiment of the present application, the value of C1/C2 is limited to 0.7 to 1, so as to reduce the capacity difference caused by the buffer 30 and improve the performance of the battery 2.

In some embodiments, the first battery cell 5 and the second battery cell 6 have the same shape, so as to reduce the difficulty of stacking the first battery cell 5 and the second battery cell 6 and simplify the assembly process.

In some embodiments, the battery 2 includes at least one battery module 2a, and the battery module 2a includes a plurality of first battery cells 5 and a plurality of second battery cells 6 stacked in the first direction X.

One or more battery modules 2a may be provided.

In some embodiments, the battery module 2a further includes a frame structure (not shown) for securing the first battery cell 5 and the second battery cell 6. Illustratively, the frame structure includes two end plates disposed oppositely in the first direction X, between which the plurality of first battery cells 5 and the plurality of second battery cells 6 are stacked, the two end plates sandwiching the first battery cells 5 and the second battery cells 6 from both ends.

In some embodiments, in the battery module 2a, the second battery cell 6 is disposed between any adjacent two of the first battery cells 5.

The adjacent two first battery cells 5 may provide a space for the expansion of the second battery cell 6 therebetween, so as to reduce the expansion force of the second battery cell 6 and improve the cycle performance of the second battery cell 6. The second battery cell 6 spaces the adjacent first battery cells 5 to reduce the waste of compressible space of the buffer member 30. The second battery monomer 6 is not internally provided with the buffer member 30, the structural strength of the buffer member is high, the second battery monomer 6 is arranged between the adjacent first battery monomers 5, the pressure between the adjacent battery monomers can be ensured, and the risk of the battery monomer shifting when being subjected to external impact is reduced.

In some embodiments, the battery module 2a is provided in plurality, and the plurality of battery modules 2a are arranged in the second direction Y, and the first direction X is perpendicular to the second direction Y. The first battery cells 5 of the adjacent battery modules 2a are arranged offset in the first direction X.

In the present embodiment, the offset arrangement means that the first battery cell 5 of one battery module 2a does not overlap with the first battery cell 5 of another adjacent battery module 2a in the second direction Y. Alternatively, the first battery cell 5 of one battery module 2a and the second battery cell 6 of another adjacent battery module 2a are arranged in the second direction Y.

In this embodiment, the battery cell adjacent to each first battery cell 5 is the second battery cell 6, so that the buffer member 30 of the first battery cell 5 provides a space for the expansion of the second battery cell 6 by compression, thereby improving the utilization rate of the compressible space of the buffer member 30, reducing stress concentration, and improving the cycle performance of the first battery cell 5 and the cycle performance of the second battery cell 6.

In some embodiments, both ends of the battery module 2a in the first direction X are provided as the second battery cells 6.

In the battery module 2a, the swelling force is concentrated toward the middle of the battery module 2a, and accordingly, the swelling force at both ends of the battery module 2a is small, and therefore, the second battery cells 6 may be disposed at both ends of the battery module 2a in the first direction X.

The second battery cell 6 is not provided with the buffer member 30, the structural strength of the second battery cell is high, the second battery cell 6 is arranged at the two ends of the battery module 2a along the first direction X, the end plates can conveniently clamp the second battery cell 6, and clamping force is guaranteed.

In some embodiments, one end of the housing 21 along the third direction Z is provided with an opening, and the third direction Z is perpendicular to the first direction X and the second direction Y.

Fig. 7 is a simplified schematic diagram of a battery according to further embodiments of the present application.

As shown in fig. 7, in some embodiments, in the battery module 2a, the first battery cells 5 and the second battery cells 6 are alternately arranged in the first direction X.

In the embodiment of the present application, each first battery cell 5 may provide a space for the expansion of the second battery cell 6 adjacent to the first battery cell 5, so as to reduce the expansion force of the second battery cell 6, and improve the cycle performance of the first battery cell 5 and the cycle performance of the second battery cell 6.

The present embodiment may also simplify the stacking process of the first battery cell 5 and the second battery cell 6, and improve the assembly efficiency of the battery 2.

Fig. 8 is a simplified schematic diagram of a battery according to further embodiments of the present application.

As shown in fig. 8, in some embodiments, the battery module 2a includes a first battery pack 2b and a second battery pack 2c arranged along the first direction X, the first battery pack 2b includes a plurality of first battery cells 5 sequentially stacked along the first direction X, and the second battery pack 2c includes a plurality of second battery cells 6 sequentially stacked along the first direction X.

The first battery cell 5 and the second battery cell 6 are different, and the battery management system needs to adopt different control modes for the first battery cell 5 and the second battery cell 6. This application embodiment arranges a plurality of first battery monomer 5 in groups, arranges a plurality of second battery monomer 6 in groups, can reduce the degree of difficulty that battery management system managed first battery monomer 5 and second battery monomer 6.

In some embodiments, in the battery module 2a, the plurality of first battery stacks 2b and the plurality of second battery stacks 2c are alternately arranged in the first direction X. Each first battery pack 2b may provide a space for expansion of the plurality of second battery cells 6 of the second battery pack 2c adjacent thereto to reduce the expansion force of the second battery cells 6, improving the cycle performance of the first battery cells 5 and the cycle performance of the second battery cells 6.

According to some embodiments of the present application, there is also provided an electric device, which includes the battery provided in any of the above embodiments, wherein the battery is used for providing electric energy for the electric device.

According to some embodiments of the present application, referring to fig. 3 to 6, a battery 2 of an embodiment of the present application includes a plurality of battery modules 2a, the battery modules 2a including a plurality of first battery cells 5 and a plurality of second battery cells 6 stacked in a first direction X, the plurality of battery modules 2a being arranged in a second direction Y, the first direction X being perpendicular to the second direction Y.

Each of the first and

second battery cells

5 and 6 includes a case 20 and an electrode assembly 10 accommodated in the case 20. The first battery cell 5 further includes a buffer member 30 accommodated in the case 20, at least a portion of the buffer member 30 overlapping the electrode assembly 10 in the first direction X, the buffer member 30 being configured to compress when the electrode assembly 10 expands. The buffer member 30 is not provided in the case 20 of the second battery cell 6.

In the battery module 2a, a second battery cell 6 is provided between any adjacent two first battery cells 5. The first battery cells 5 of the adjacent battery modules 2a are arranged offset in the first direction X.

While the present application has been described with reference to preferred embodiments, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the present application, and in particular, features shown in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims

1. A battery comprising a first cell and a second cell disposed in a first direction, each of the first cell and the second cell comprising a housing and an electrode assembly housed within the housing;

the first battery cell further includes a buffer member housed within the case, at least a portion of the buffer member overlapping the electrode assembly in the first direction, the buffer member configured to compress when the electrode assembly expands;

the buffer member is not disposed in the case of the second battery cell.

2. The battery according to claim 1, comprising at least one battery module including a plurality of the first battery cells and a plurality of the second battery cells stacked in the first direction.

3. The battery according to claim 2, wherein the second battery cell is provided between any adjacent two of the first battery cells in the battery module.

4. The battery according to claim 3, wherein the first battery cell and the second battery cell are alternately arranged in the first direction in the battery module.

5. The battery according to claim 2, wherein the battery module includes a first battery pack and a second battery pack arranged in the first direction, the first battery pack includes a plurality of the first battery cells sequentially stacked in the first direction, and the second battery pack includes a plurality of the second battery cells sequentially stacked in the first direction.

6. The battery according to claim 5, wherein a plurality of the first battery stacks and a plurality of the second battery stacks are alternately arranged in the first direction.

7. The battery according to claim 2, wherein the battery module is provided in plurality, and the plurality of battery modules are arranged in a second direction, the first direction being perpendicular to the second direction;

the first battery cells of the adjacent battery modules are arranged in a staggered manner in the first direction.

8. The battery according to claim 2, wherein both ends of the battery module in the first direction are provided as the second battery cell.

9. The battery of claim 1, wherein the number of the first battery cells is m, the number of the second battery cells is n, and both m and n are positive integers greater than 0;

m and n satisfy: m/(m + n) is more than or equal to 0.2 and less than or equal to 0.95.

10. The battery according to claim 1, wherein the capacity of the first battery cell is C1, the capacity of the second battery cell is C2, and C1 and C2 satisfy: C1/C2 is more than or equal to 0.7 and less than or equal to 1.

11. The battery of claim 1, wherein the first cell has the same outer shape as the second cell.

12. An electrical device comprising a battery as claimed in any one of claims 1 to 11 for providing electrical energy.