Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device. The battery monomer comprises a shell, an electrode assembly and a buffer structure, the buffer structure is arranged between the electrode assembly and the side wall of the shell, the buffer structure comprises a buffer part, and the buffer part comprises a first contact piece and a telescopic piece; the telescopic piece is arranged between the first contact piece and the side wall, and the telescopic piece is used for absorbing and buffering deformation of the electrode assembly; the first contact piece is made of a hard material, the first contact piece plays a role in supporting the battery monomer, and when the battery core assembly expands and extrudes the first contact piece, pressure is dispersed to the whole first contact piece, and the first contact piece integrally extrudes the telescopic piece, so that the overall stress of the buffer part is uniform, and the problems that when the buffer part is made of a flexible material, the local stress of the flexible material is not uniform, and the service life of the battery is influenced are solved. The stress concentration of partial region of the electrode assembly is caused; and the lithium precipitation of the pole piece is caused.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] At present, the batteries most commonly used in vehicles are generally lithium-ion batteries. As a rechargeable battery, lithium-ion batteries have the advantages of small size, high energy density, high power density, many cycles and long storage time.

[0003] Rechargeable batteries generally include a shell and an electrode assembly. The shell is used to contain the electrode assembly and an electrolyte. The electrode assembly generally includes a positive electrode sheet and a negative electrode sheet. Electric energy is generated by the movement of metal ions (such as lithium ions) between the positive electrode sheet and the negative electrode sheet.

[0004] Lithium deposition is a common abnormal phenomenon in lithium batteries. It affects the charging efficiency and energy density of lithium ions. When lithium deposition is severe, lithium crystals may form. Lithium crystals can pierce the isolation membrane, causing internal short circuit thermal runaway, seriously endangering the safety of the battery. Therefore, how to reduce lithium deposition is a technical problem that needs to be solved in battery technology. Utility Model Content

[0005] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can improve the problem of battery lithium deposition and enhance battery performance.

[0006] In a first aspect, the present application provides a battery cell, comprising: a shell, comprising a bottom wall and a side wall connected to the bottom wall, the bottom wall and the side wall enclosing a chamber; an electrode assembly, accommodated in the chamber; a buffer structure, accommodated in the chamber, the buffer structure comprising a buffer portion, the buffer portion being arranged between the electrode assembly and the side wall, the buffer portion comprising a first contact piece and a telescopic piece, the first contact piece being in contact with the electrode assembly, the telescopic piece being arranged between the side wall and the first contact piece, the first contact piece being made of a hard material, and the telescopic piece being telescopically arranged along the thickness direction of the first contact piece so that the distance between the first contact piece and the side wall can be adjusted.

[0007] In the scheme of the embodiment of the present application, the battery cell includes a shell, an electrode assembly and a buffer structure. The electrode assembly is accommodated in the shell, and the shell serves to accommodate and protect the electrode assembly; the buffer structure is arranged between the electrode assembly and the side wall of the shell, and the buffer structure includes a buffer part, and the buffer part includes a first contact piece and a telescopic piece. The first contact piece is in contact with the electrode assembly, and the first contact piece serves to support the electrode assembly; the telescopic piece is arranged between the first contact piece and the side wall, so that when the electrode assembly expands, the telescopic piece can be elastically deformed, and the distance between the first contact piece and the side wall is adjustable. The buffer part absorbs and buffers the deformation of the electrode assembly, reduces the risk of the electrode assembly being squeezed and damaged, and improves the battery Reliability of the single cell; the first contact piece is a hard material, and the first contact piece plays the role of supporting the battery single cell, and when the battery cell assembly expands and squeezes the first contact piece, the pressure is dispersed to the entire first contact piece, so that the pressure of the buffer structure on various parts of the shell side wall is uniform, reducing local deformation of the shell, which leads to increased difficulty in controlling the external dimensions of the battery single cell and reduced flatness of the large surface; when the battery cell assembly expands and squeezes the first contact piece, the pressure is dispersed to the entire first contact piece, and the first contact piece as a whole squeezes the telescopic piece, so that the overall force of the buffer part is uniform, so as to improve the problem that when the buffer part is made of flexible material, the flexible material is locally subjected to uneven force, resulting in stress concentration in some areas of the electrode assembly, leading to lithium deposition on the electrode sheet.

[0008] In some embodiments, two buffer portions are disposed on both sides of the electrode assembly.

[0009] In the technical solution of the embodiment of the present application, two buffer parts are arranged on both sides of the electrode assembly to improve the buffering and supporting effect of the buffer structure on the electrode assembly.

[0010] In some embodiments, the buffer structure further includes a connecting portion, which is connected between the two buffer portions, and the connecting portion is located between the electrode assembly and the bottom wall.

[0011] In the technical solution of the embodiment of the present application, the buffer structure also includes a connecting portion, which is connected between two buffer portions, so that when the buffer structure and the electrode assembly are assembled in the battery shell, the electrode assembly can drive the buffer structure to enter the battery shell smoothly by pressing the connecting portion, thereby improving the problem of wrinkling and deformation of the buffer portion caused by assembly of the buffer structure and reducing the difficulty of assembling the buffer structure; the connecting portion is located between the electrode assembly and the bottom wall, and the insulation capacity of the electrode assembly and the shell is enhanced by the connecting portion.

[0012] In some embodiments, the buffer portion further includes a second contact member, and the second contact member is disposed between the telescopic member and the side wall.

[0013] In the technical solution of the embodiment of the present application, the second contact piece is arranged between the telescopic piece and the side wall, that is, the telescopic piece is arranged between the first contact piece and the second contact piece. The second contact piece protects the telescopic piece and improves the service life of the buffer part.

[0014] In some embodiments, the telescopic member includes a plurality of telescopic units arranged at intervals, the telescopic units extending obliquely along the thickness direction of the buffer portion between the first contact member and the second contact member, and / or the telescopic unit includes a first segment, a second segment and a third segment arranged along the thickness direction of the buffer portion, the first segment is obliquely arranged along the thickness direction of the buffer portion between the second segment and the first contact member, the two first segments are respectively connected to the two ends of the second segment, the third segment is obliquely arranged along the thickness direction of the buffer portion between the second segment and the second contact member, and the two third segments are respectively connected to the two ends of the second segment.

[0015] In the technical solution of the embodiment of the present application, the telescopic part includes a plurality of telescopic units arranged at intervals, and the telescopic units extend obliquely along the thickness direction of the buffer portion between the first contact member and the second contact member. The telescopic unit has a simple structure and is easy to prepare, and / or the telescopic unit includes a first segment, a second segment and a third segment arranged along the thickness direction of the buffer portion, the first segment is obliquely arranged along the thickness direction of the buffer portion between the second segment and the first contact member, the two first segments are respectively connected to the two ends of the second segment, the third segment is obliquely arranged along the thickness direction of the buffer portion between the second segment and the second contact member, the two third segments are respectively connected to the two ends of the second segment, the telescopic unit has strong stability, and the reliability of the buffer portion is improved.

[0016] In some embodiments, the side wall includes two first side walls arranged opposite to each other along a first direction and two second side walls arranged opposite to each other along a second direction, the surface area of ​​the first side wall is greater than or equal to the surface area of ​​the second side wall, the first direction and the second direction intersect, and the buffer portion is arranged between the first side wall and the electrode assembly.

[0017] In the technical solution of the embodiment of the present application, the side wall includes two first side walls arranged opposite to each other along a first direction and two second side walls arranged opposite to each other along a second direction, the surface area of ​​the first side wall is greater than or equal to the surface area of ​​the second side wall, the first direction and the second direction intersect, and the buffer portion is arranged between the first side wall and the electrode assembly, that is, the buffer portion is arranged on the large surface of the electrode assembly and the side wall assembly, so that the buffer portion can fully play the effect of buffering the expansion of the electrode assembly.

[0018] In some embodiments, the buffer portion is disposed between the second side wall and the electrode assembly, and the second side wall is insulated from the electrode assembly by the buffer portion.

[0019] In the technical solution of the embodiment of the present application, the buffer portion is arranged between the second side wall and the electrode assembly. The second side wall is insulated from the electrode assembly by the buffer structure, so as to improve the insulation reliability between the electrode assembly and the shell. The buffer portion is arranged between the second side wall and the shell, and no additional mold is required, thereby reducing the difficulty of preparing the battery cell.

[0020] In some embodiments, the buffer structure further includes an insulating member, which is disposed between the second side wall and the electrode assembly, and the second side wall is insulated from the electrode assembly by the insulating member.

[0021] In the technical solution of the embodiment of the present application, the buffer structure also includes an insulating part, which is arranged between the second side wall and the electrode assembly. The second side wall is insulated from the electrode assembly by the insulating part, thereby improving the insulation reliability between the electrode assembly and the shell. The second side wall is insulated from the electrode assembly by the insulating part, the insulating part has a simple structure, and the material cost is low, thereby reducing the preparation cost of the battery cell.

[0022] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell according to an embodiment of the first aspect.

[0023] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery of the embodiment of the second aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0025] Figure 1 is a structural schematic diagram of a vehicle provided by an embodiment of the present application;

[0026] Figure 2 is a schematic diagram of the structure of a battery provided in one embodiment of the present application;

[0027] Figure 3 is a schematic structural diagram of a battery module provided in one embodiment of the application;

[0028] Figure 4 is an exploded diagram of a battery cell provided in one embodiment of the present application;

[0029] Figure 5 is a schematic structural diagram of a battery cell provided in one embodiment of the present application;

[0030] Figure 6 It is a structural schematic diagram of a buffer structure of a battery cell provided in one embodiment of the present application;

[0031] Figure 7 yes Figure 5 Sectional view at AA in the middle;

[0032] Figure 8 It is a structural schematic diagram of a buffer structure of a battery cell provided in one embodiment of the present application;

[0033] Fig. 9 yes Figure 6 The enlarged view of point B in the middle;

[0034] Fig.10 yes Figure 8 Enlarged view of point C in the middle;

[0035] Fig.11 It is an exploded diagram of a battery cell provided in one embodiment of the present application.

[0036] Description of reference numerals:

[0037] 1. Vehicle; 101. Motor; 102. Controller;

[0038] 2. Battery; 201. Battery module; 202. Box; 2021. First box portion; 2022. Second box portion;

[0039] 3. Battery cells;

[0040] 4. Shell; 41. Bottom wall; 42. Side wall; 421. First side wall; 422. Second side wall;

[0041] 5. Electrode assembly;

[0042] 6. Top cover assembly;

[0043] 7. Buffer structure; 71. Buffer part; 72. Connecting part; 73. Insulating member; 711. First contact member; 712. Telescopic member; 713. Second contact member;

[0044] 8. telescopic unit; 81. first segment; 82. second segment; 83. third segment. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0046] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0047] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0048] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0049] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0050] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0052] In the present 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, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this.

[0053] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0054] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. A battery cell mainly works by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive current collector and a positive electrode ear connected to the positive current collector. The positive current collector is coated with a positive active material layer, and the positive electrode ear is not coated with a positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative current collector and a negative electrode tab connected to the negative current collector, the negative current collector is coated with the negative active material layer, and the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0055] In the prior art, some batteries have the problem of lithium deposition.

[0056] In the related art, foam is filled between the electrode assembly and the battery shell to absorb the expansion of the electrode assembly. However, since the foam material is relatively soft, when the electrode assembly expands, the foam is subjected to uneven force in various places, resulting in deformation, wrinkling, and lamination of the foam in some areas. This causes uneven force in some areas of the electrode assembly, stress concentration, and causes lithium plating problems.

[0057] Based on the above problems, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and a buffer structure. The electrode assembly is accommodated in the shell, and the shell serves to accommodate and protect the electrode assembly; the buffer structure is arranged between the electrode assembly and the side wall of the shell, the buffer structure includes a buffer part, the buffer part includes a first contact piece and a telescopic piece, the first contact piece is in contact with the electrode assembly, and the first contact piece serves to support the electrode assembly; the telescopic piece is arranged between the first contact piece and the side wall, so that when the electrode assembly expands, the telescopic piece can undergo elastic deformation, the distance between the first contact piece and the side wall is adjustable, and the buffer part absorbs and buffers the deformation of the electrode assembly, thereby reducing the risk of the electrode assembly being squeezed and damaged. Risk, improve the reliability of the battery cell; the first contact piece is a hard material, the first contact piece plays the role of supporting the battery cell, and when the battery cell assembly expands and squeezes the first contact piece, the pressure is dispersed to the entire first contact piece, so that the pressure of the buffer structure on various parts of the shell side wall is uniform, and the local deformation of the shell is reduced, which leads to the problem of increased difficulty in controlling the external dimensions of the battery cell and reduced flatness of the large surface; when the battery cell assembly expands and squeezes the first contact piece, the pressure is dispersed to the entire first contact piece, and the first contact piece squeezes the telescopic piece as a whole, so that the buffer part is evenly stressed, so as to improve the problem that when the buffer part is made of flexible material, the flexible material is locally subjected to uneven stress, resulting in stress concentration in some areas of the electrode assembly and lithium deposition in the electrode piece.

[0058] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0059] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0060] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the batteries and electrical equipment described above, but can also be applied to all batteries including a box and electrical equipment using the battery. However, for the sake of simplicity, the following embodiments are described using electric vehicles as an example.

[0061] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1 provided for some embodiments of the present application. Vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 2 is provided inside the vehicle 1, and the battery may be provided at the bottom, head or tail of the vehicle 1. Battery 2 may be used to power the vehicle 1, for example, battery 2 may be used as an operating power source for the vehicle 1. Vehicle 1 may also include a controller 102 and a motor 101, and the controller 102 is used to control the battery to power the motor 101, for example, for starting, navigating and operating power requirements of the vehicle 1 during driving.

[0062] In some embodiments of the present application, the battery can be used not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0063] In order to meet different power requirements, the battery 2 may include a plurality of battery cells, and a battery cell refers to the smallest unit that constitutes a battery module or a battery pack. A plurality of battery cells can be connected in series and / or in parallel via electrode terminals for use in various applications. The battery 2 mentioned in the present application includes a battery module or a battery pack. Among them, a plurality of battery cells can be connected in series, in parallel, or in mixed connection, and mixed connection refers to a mixture of series and parallel connection. In the embodiments of the present application, a plurality of battery cells can directly constitute a battery pack, or they can first constitute a battery module, and then the battery module constitutes a battery pack.

[0064] Figure 2 A schematic structural diagram of a battery 2 according to an embodiment of the present application is shown.

[0065] like Figure 2 As shown, the battery includes a housing 202 and a battery cell (not shown), and the battery cell is accommodated in the housing 202 .

[0066] The box 202 may be a simple three-dimensional structure such as a single cuboid, cylinder or sphere, or a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders or spheres. The box 202 may be made of alloy materials such as aluminum alloy, iron alloy, polymer materials such as polycarbonate, polyisocyanurate foam plastic, or composite materials such as glass fiber and epoxy resin.

[0067] The box 202 is used to accommodate the battery cells, and the box 202 can be of various structures. In some embodiments, the box 202 can include a first box portion 2021 and a second box portion 2022, the first box portion 2021 and the second box portion 2022 cover each other, and the first box portion 2021 and the second box portion 2022 jointly define a storage space for accommodating the battery cells 3. The second box portion 2022 can be a hollow structure with one end open, the first box portion 2021 is a plate-like structure, and the first box portion 2021 covers the open side of the second box portion 2022 to form a box 202 with a storage space; the first box portion 2021 and the second box portion 2022 can also be hollow structures with one side open, and the open side of the first box portion 2021 covers the open side of the second box portion 2022 to form a box 202 with a storage space. Of course, the first box body 2021 and the second box body 2022 can be in various shapes, such as a cylinder, a cuboid, etc.

[0068] In order to improve the sealing performance after the first box body 2021 and the second box body 2022 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 2021 and the second box body 2022 .

[0069] Assuming that the first box body portion 2021 covers the top of the second box body portion 2022 , the first box body portion 2021 can also be referred to as an upper box cover, and the second box body portion 2022 can also be referred to as a lower box cover.

[0070] In the battery 2, there can be one or more battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells are connected in series and in parallel. Multiple battery cells can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells can be accommodated in the box 202; of course, multiple battery cells can also be connected in series, in parallel, or in mixed connection to form a battery module 201, and then multiple battery modules 201 can be connected in series, in parallel, or in mixed connection to form a whole, and then accommodated in the box 202.

[0071] Figure 3 A schematic structural diagram of a battery module 201 according to an embodiment of the present application is shown.

[0072] In some embodiments, Figure 2 and Figure 3 As shown, there are multiple battery cells 3, and the multiple battery cells 3 are first connected in series, parallel or mixed to form a battery module 201. The multiple battery modules 201 are then connected in series, parallel or mixed to form a whole, and are accommodated in the box 202.

[0073] The multiple battery cells 3 in the battery module 201 can be electrically connected via a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 3 in the battery module 201 .

[0074] In the present application, the battery cell 3 may include a lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., which is not limited in the embodiments of the present application.

[0075] Figure 4 The schematic diagram of the structure of the battery cell 3 provided in some embodiments of the present application. The battery cell 3 refers to the smallest unit that constitutes the battery. Figure 4 The battery cell 3 includes a top cover assembly 6 , a shell 4 and an electrode assembly 5 .

[0076] The electrode assembly 5 is a component in the battery cell 3 where electrochemical reactions occur. One or more electrode assemblies 5 may be included in the housing 4. The electrode assembly 5 is mainly formed by winding or stacking pole sheets, which are divided into positive pole sheets and negative pole sheets, and a separator is usually provided between the positive pole sheet and the negative pole sheet. The parts of the positive pole sheet and the negative pole sheet with active materials constitute the electrode body, and the parts of the positive pole sheet and the negative pole sheet without active materials each constitute a pole ear. The positive pole ear and the negative pole ear may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the pole ears connect the electrode terminals to form a current loop.

[0077] The shell 4 is a component used to cooperate with the top cover assembly 6 to form the internal environment of the battery cell 3, wherein the formed internal environment can be used to accommodate the electrode assembly 5, the electrolyte (not shown in the figure) and other components. The shell 4 and the top cover assembly 6 can be independent components, and an opening can be set on the shell 4, and the internal environment of the battery cell 3 is formed by covering the opening with the top cover assembly 6 at the opening. Optionally, the top cover assembly 6 and the shell 4 can also be integrated. Optionally, the top cover assembly 6 and the shell 4 can form a common connection surface before other components are put into the shell, and when it is necessary to encapsulate the interior of the shell 4, the top cover assembly 6 covers the shell 4. The material of the shell 4 can be various, and the material of the shell 4 can be copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0078] See also Figures 5 to 7 , Figure 5 is a schematic structural diagram of a battery cell provided in one embodiment of the present application; Figure 6 It is a structural schematic diagram of a buffer structure of a battery cell provided in one embodiment of the present application; Figure 7 yes Figure 5 Cross-sectional view at AA in the middle.

[0079] First, as Figures 4 to 7As shown, the present application provides a battery cell 3, the battery cell 3 includes a shell 4, an electrode assembly 5 and a buffer structure 7, the shell 4 includes a bottom wall 41 and a side wall 42 connected to the bottom wall 41, the bottom wall 41 and the side wall 42 enclose a chamber; the electrode assembly 5 is accommodated in the chamber; the buffer structure 7 is accommodated in the chamber, the buffer structure 7 includes a buffer portion 71, the buffer portion 71 is arranged between the electrode assembly 5 and the side wall 42, the buffer portion 71 includes a first contact piece 711 and a telescopic piece 712, the first contact piece 711 is in contact with the electrode assembly 5, the telescopic piece 712 is arranged between the side wall 42 and the first contact piece 711, the first contact piece 711 is a hard material, and the telescopic piece 712 is telescopically arranged along the thickness direction of the first contact piece 711, so that the distance between the first contact piece 711 and the side wall 42 is adjustable.

[0080] In the scheme of the embodiment of the present application, the battery cell 3 includes a shell 4, an electrode assembly 5 and a buffer structure 7. The electrode assembly 5 is accommodated in the shell 4, and the shell 4 serves to accommodate and protect the electrode assembly 5; the buffer structure 7 is arranged between the electrode assembly 5 and the side wall 42 of the shell 4, and the buffer structure 7 includes a buffer portion 71, and the buffer portion 71 includes a first contact piece 711 and a telescopic piece 712. The first contact piece 711 contacts the electrode assembly 5, and the first contact piece 711 serves to support the electrode assembly 5; the telescopic piece 712 is arranged between the first contact piece 711 and the side wall 42, so that when the electrode assembly 5 expands, the telescopic piece 712 can undergo elastic deformation, and the distance between the first contact piece 711 and the side wall 42 is adjustable. The buffer portion 71 absorbs and buffers the deformation of the electrode assembly 5, thereby reducing the compression of the electrode assembly 5. The risk of damage is reduced, and the reliability of the battery cell 3 is improved; and the first contact piece 711 is a hard material, and the first contact piece 711 plays a role in supporting the battery cell 3. When the battery cell assembly expands and squeezes the first contact piece 711, the pressure is dispersed to the entire first contact piece 711, and the first contact piece 711 squeezes the telescopic piece 712 as a whole, so that the buffer part 71 is uniformly stressed as a whole, so as to improve the problem that when the buffer part 71 is made of a flexible material, the local force is uneven, resulting in stress concentration in some areas of the electrode assembly 5, resulting in lithium deposition on the pole piece, and it can also improve the problem that when the buffer part 71 is made of a flexible material, the buffer part 71 is unevenly stressed, resulting in excessive force on the side wall 42 of the shell 4 and deformation, resulting in difficulty in controlling the external dimensions of the battery cell 3 and reduced flatness of the large surface, thereby improving the grouping efficiency of the battery 2 to improve the performance of the battery 2.

[0081] The buffer structure 7 includes a buffer portion 71, and the buffer portion 71 includes a first contact piece 711 and a telescopic piece 712. The first contact piece 711 contacts the electrode assembly 5, and the telescopic piece 712 is telescopically arranged along the thickness direction of the first contact piece 711, so that when the electrode assembly 5 expands, the electrode assembly 5 squeezes the first contact piece 711, and then under the elastic action of the telescopic piece 712, the distance between the first contact piece 711 and the side wall 42 changes, and the expansion squeezing force of the electrode assembly 5 is absorbed by the telescopic deformation of the telescopic piece 712 to improve the problem of lithium deposition caused by excessive deformation of the electrode assembly 5.

[0082] The electrode assembly 5 is insulated from the housing 4 by the buffer portion 71. Specifically, at least one of the first contact member 711 and the telescopic member 712 is made of an insulating material. Optionally, both the first contact member 711 and the telescopic member 712 are made of an insulating material to improve the insulating performance of the insulating portion.

[0083] “The first contact member 711 contacts the electrode assembly 5 and is made of a hard material”, specifically, the first contact member 711 is a hard material plate member that contacts the electrode assembly 5. Exemplarily, the first contact member 711 is a hard plastic plate or a hard rubber plate.

[0084] In the prior art, foam is filled between the electrode assembly 5 and the shell 4. Since the foam itself is a flexible material, during the process of repeated compression and resetting, due to uneven force in various places, it is easy to cause local wrinkles and stacking, as well as local elastic changes, resulting in local stress concentration in the electrode assembly 5, leading to lithium plating problems.

[0085] Therefore, in the embodiment of the present application, the first contact piece 711 is made of a hard material, specifically a hard plate, so that the extrusion force of the electrode assembly 5 is dispersed to the entire first contact piece 711, the first contact surface has high flatness, and the electrode assembly 5 is subjected to uniform force at various locations of the first contact piece 711, so as to reduce the risk of local stress concentration in the electrode assembly 5 and causing lithium deposition.

[0086] In the embodiment of the present application, the first contact member 711 is made of a hard material, specifically a hard plate, so that when the electrode assembly 5 squeezes the first contact member 711, the first contact member 711 squeezes the battery 2 shell 4 as a whole through the telescopic member 712, so that the pressure between the buffer portion 71 and the side wall 42 of the shell 4 is uniform, thereby reducing the problem of uneven force in some areas of the side wall 42 of the shell 4, resulting in deformation of the side wall 42, reduced flatness of the large surface of the shell 4, and changes in the external dimensions of the shell 4.

[0087] Optionally, one end of the first contact member 711 abuts against the bottom wall 41 , and the other end thereof abuts against the cover plate. The first contact member 711 supports the housing 4 to improve the structural strength of the battery cell 3 .

[0088] Optionally, the first contact member 711 and the telescopic member 712 are integrally formed, and the buffer portion 71 can be made of PC (Polycarbonate) or PP material, and is integrally formed by injection molding or extrusion molding, which has low processing difficulty and good structural consistency. Alternatively, the first contact member 711 and the telescopic member 712 are separately prepared, and the telescopic member 712 can be elastic foam, and the telescopic member 712 and the first contact member 711 are bonded and connected.

[0089] In some embodiments, Figure 5 and Figure 7 As shown, two buffer portions 71 are disposed on both sides of the electrode assembly 5 .

[0090] In these embodiments, two buffer portions 71 are disposed on both sides of the electrode assembly 5 to enhance the buffering and supporting effect of the buffer structure 7 on the electrode assembly 5 .

[0091] The two buffer parts 71 are disposed on both sides of the electrode assembly 5, and the position of the electrode assembly 5 in the housing 4 can be fixed by the buffer parts 71. The electrode assembly 5 expands synchronously on its opposite sides, so the two buffer parts 71 are disposed on both sides of the electrode assembly 5 to make the forces on both sides of the electrode assembly 5 uniform, improve the buffering effect of the buffer structure 7 on the electrode assembly 5, and reduce the problem of lithium deposition caused by excessive expansion of the electrode assembly 5, or excessive compression of the housing 4 by the electrode assembly 5, resulting in damage to the battery cell 3.

[0092] Optionally, the buffer portions 71 disposed on both sides of the electrode assembly 5 have the same structure and size, so that the forces on both sides of the electrode assembly 5 are uniform.

[0093] In some embodiments, Figures 4 to 7 As shown, the buffer structure 7 further includes a connecting portion 72 , which is connected between the two buffer portions 71 , and the connecting portion 72 is located between the electrode assembly 5 and the bottom wall 41 .

[0094] In these embodiments, the buffer structure 7 also includes a connecting portion 72, which is connected between the two buffer portions 71, so that when the buffer structure 7 and the electrode assembly 5 are assembled in the battery 2 shell 4, the electrode assembly 5 can drive the buffer structure 7 to smoothly enter the battery 2 shell 4 by pressing the connecting portion 72, thereby improving the problem of wrinkling and deformation of the buffer portion 71 caused by the assembly of the buffer structure 7, and reducing the difficulty of assembling the buffer structure 7; the connecting portion 72 is located between the electrode assembly 5 and the bottom wall 41, and the insulation capacity of the electrode assembly 5 and the shell 4 is enhanced by the connecting portion 72.

[0095] During the process of assembling the buffer structure 7 and the electrode assembly 5 in the shell 4, the two buffer parts 71 are connected by the connecting part 72, the electrode assembly 5 is arranged between the two buffer parts 71, and the connecting part 72 is located between the electrode assembly 5 and the shell 4. During the process of the electrode assembly 5 pressing the connecting part 72 and entering the interior of the shell 4 through the opening of the shell 4, the connecting part 72 can drive the buffer part 71 to move toward the bottom wall 41 in the gap between the electrode assembly 5 and the side wall 42. Due to the traction and stretching effect of the connecting part 72, the buffer part 71 can be stretched smoothly between the side wall 42 and the electrode assembly 5, reducing the risk of wrinkling and bending of the buffer part 71.

[0096] Optionally, the connecting portion 72 is made of insulating material to improve the insulation effect between the electrode assembly 5 and the bottom wall 41 of the shell 4 .

[0097] Optionally, the connection part 72 and the insulating part are integrally provided to improve the overall strength of the buffer structure 7; or the connection part 72 and the insulating part are bonded or sewed to facilitate the selection of materials for the connection part 72 and the insulating part.

[0098] Optionally, the connecting portion 72 and the insulating portion have the same structure, and no additional mold is required for the connecting portion 72 , thereby reducing the preparation cost of the buffer structure 7 .

[0099] Optionally, the connecting portion 72 is an insulating sheet, and the material cost of the insulating sheet is lower than that of the insulating portion, so as to reduce the material cost of the buffer structure 7 .

[0100] Optionally, the connection portion 72 is made of a flexible insulating material to reduce the risk of the connection portion 72 being squeezed and damaged during assembly.

[0101] In some embodiments, Figures 4 to 7 As shown, the buffer portion 71 further includes a second contact member 713 , and the second contact member 713 is disposed between the telescopic member 712 and the side wall 42 .

[0102] In these embodiments, the second contact member 713 is disposed between the telescopic member 712 and the side wall 42 , that is, the telescopic member 712 is disposed between the first contact member 711 and the second contact member 713 . The second contact member 713 protects the telescopic member 712 and improves the service life of the buffer portion 71 .

[0103] Optionally, the second contact member 713 is made of a hard material and is disposed between the telescopic member 712 and the side wall 42 , so that the second contact member 713 can guide the telescopic member 712 into the shell 4 , thereby reducing the difficulty of assembling the shell 4 and the buffer structure 7 .

[0104] Optionally, the second contact member 713 is an insulating plate member to improve the insulation performance of the shell 4 and the electrode assembly 5 .

[0105] Optionally, the first contact member 711 and the second contact member 713 have the same structure, and the second contact member 713 does not need to be additionally molded, thereby reducing the preparation cost of the buffer structure 7 .

[0106] Optionally, the first contact member 711, the second contact member 713 and the telescopic member 712 are integrally prepared and integrally formed by injection molding or extrusion molding, which has low processing difficulty and good structural consistency.

[0107] Optionally, an adhesive layer is provided between the second contact member 713 and the side wall 42 to improve the connection reliability between the buffer structure 7 and the housing 4 .

[0108] See also Figures 8 to 10 , Figure 8 It is a structural schematic diagram of a buffer structure of a battery cell provided in one embodiment of the present application; Fig. 9 yes Figure 6 The enlarged view of point B in the middle; Fig.10 yes Figure 8 Enlarged view of point C in the middle.

[0109] In some embodiments, Figures 6 to 10 As shown, the telescopic member 712 includes a plurality of telescopic units 8 arranged at intervals, the telescopic unit 8 extending obliquely along the thickness direction of the buffer portion 71 between the first contact member 711 and the second contact member 713, and / or the telescopic unit 8 includes a first segment 81, a second segment 82 and a third segment 83 arranged along the thickness direction of the buffer portion 71, the first segment 81 is obliquely arranged along the thickness direction of the buffer portion 71 between the second segment 82 and the first contact member 711, the two first segments 81 are respectively connected to the two ends of the second segment 82, the third segment 83 is obliquely arranged along the thickness direction of the buffer portion 71 between the second segment 82 and the second contact member 713, and the two third segments 83 are respectively connected to the two ends of the second segment 82.

[0110] In these embodiments, the telescopic member 712 includes a plurality of telescopic units 8 arranged at intervals, the telescopic unit 8 extending obliquely along the thickness direction of the buffer portion 71 between the first contact member 711 and the second contact member 713, the telescopic unit 8 has a simple structure and is easy to prepare, and / or the telescopic unit 8 includes a first segment 81, a second segment 82 and a third segment 83 arranged along the thickness direction of the buffer portion 71, the first segment 81 is obliquely arranged along the thickness direction of the buffer portion 71 between the second segment 82 and the first contact member 711, the two first segments 81 are respectively connected to the two ends of the second segment 82, the third segment 83 is obliquely arranged along the thickness direction of the buffer portion 71 between the second segment 82 and the second contact member 713, the two third segments 83 are respectively connected to the two ends of the second segment 82, the telescopic unit 8 has strong stability, and the reliability of the buffer portion 71 is improved.

[0111] The telescopic member 712 includes a plurality of telescopic units 8 arranged at intervals, and each telescopic unit 8 is telescopically arranged along the thickness direction of the buffer portion 71 .

[0112] Optionally, the telescopic members 712 are evenly spaced so that the buffer portion 71 is subjected to uniform force at all locations.

[0113] Optional, such as Fig.10 As shown, the telescopic unit 8 is tilted between the first contact piece 711 and the second contact piece 713. When the electrode assembly 5 expands and squeezes the first contact piece 711, the two ends of the tilted telescopic unit 8 approach each other, the telescopic unit 8 is in a compressed state, and the distance between the first contact piece 711 and the side wall 42 decreases; when the electrode assembly 5 contracts, the telescopic unit 8 stretches, the two ends of the tilted telescopic unit 8 move away from each other, and the distance between the first contact piece 711 and the second contact piece 713 increases. Optionally, the tilt directions of the telescopic units 8 are the same, so that the buffer portion 71 is subjected to uniform force at all locations.

[0114] Optional, such as Fig. 9 As shown, the telescopic unit 8 includes a first segment 81, a second segment 82 and a third segment 83. The first segment 81 is obliquely arranged between the second segment 82 and the first contact member 711 along the thickness direction of the buffer portion 71. The two first segments 81 are respectively connected to the two ends of the second segment 82. The third segment 83 is obliquely arranged between the second segment 82 and the second contact member 713 along the thickness direction of the buffer portion 71. The two third segments 83 are respectively connected to the two ends of the second segment 82. When the electrode assembly 5 expands and squeezes the first contact member 711, the end connected to the first segment 81 and the first contact member 711 and the end connected to the third segment 83 and the second contact member 713 are connected. The ends connected are close to each other, the ends connected to the two first segments 81 and the first contact piece 711 are away from each other, and the ends connected to the two third segments 83 and the second contact piece 713 are away from each other, so that the first contact piece 711 is close to the second contact piece 713; when the electrode assembly 5 contracts, the end connected to the first segment 81 and the first contact piece 711 and the end connected to the third segment 83 and the second contact piece are away from each other, the ends connected to the two first segments 81 and the first contact piece 711 are close to each other, and the ends connected to the two third segments 83 and the second contact piece 713 are close to each other, so that the first contact piece 711 is away from the second contact piece 713.

[0115] Optionally, the telescopic member 712 may be an elastic foam sandwiched between the first contact member 711 and the second contact member 713 . Alternatively, the telescopic member 712 may be an elastic foam sandwiched between the first contact member 711 and the side wall 42 .

[0116] See also Fig.11 , Fig.11 It is an exploded diagram of a battery cell provided in one embodiment of the present application.

[0117] In some embodiments, Fig.11 As shown, the side wall 42 includes two first side walls 421 arranged opposite to each other along the first direction X and two second side walls 422 arranged opposite to each other along the second direction Y, the surface area of ​​the first side wall 421 is greater than or equal to the surface area of ​​the second side wall 422, the first direction X and the second direction Y intersect, and the buffer portion 71 is arranged between the first side wall 421 and the electrode assembly 5.

[0118] In these embodiments, the side wall 42 includes two first side walls 421 arranged opposite to each other along the first direction X and two second side walls 422 arranged opposite to each other along the second direction Y, the surface area of ​​the first side wall 421 is greater than or equal to the surface area of ​​the second side wall 422, the first direction X and the second direction Y intersect, and the buffer portion 71 is arranged between the first side wall 421 and the electrode assembly 5, that is, the buffer portion 71 is arranged on the large surface of the electrode assembly 5 and the side wall 42 assembly, so that the buffer portion 71 can fully play the role of buffering the expansion of the electrode assembly 5.

[0119] Optionally, in the first direction X, the cross-sectional area of ​​the first side wall 421 is the same as the cross-sectional area of ​​the buffer portion 71 , that is, the buffer portion 71 can completely cover the side of the first side wall 421 facing the electrode assembly 5 to enhance the buffering effect of the buffer structure 7 on the electrode assembly 5 .

[0120] Optionally, the first side wall 421 is insulated from the shell 4 by the buffer portion 71 , an insulating gap exists between the second side wall 422 and the electrode assembly 5 , and the electrode assembly 5 is insulated from the second side wall 422 by the insulating gap.

[0121] In some embodiments, Figure 6 and Fig.11 As shown, the buffer portion 71 is disposed between the second side wall 422 and the electrode assembly 5 , and the second side wall 422 is insulated from the electrode assembly 5 by the buffer portion 71 .

[0122] In these embodiments, the buffer portion 71 is disposed between the second side wall 422 and the electrode assembly 5. The second side wall 422 is insulated from the electrode assembly 5 by the buffer structure 7, thereby improving the insulation reliability between the electrode assembly 5 and the shell 4. The buffer portion 71 is disposed between the second side wall 422 and the shell 4 without the need for additional mold opening, thereby reducing the difficulty of preparing the battery cell 3.

[0123] A buffer portion 71 is disposed between the second side wall 422 and the electrode assembly 5 , and is insulated from the electrode assembly 5 by the electrode assembly 5 and the second side wall 422 .

[0124] Optionally, the electrode assembly 5 and the connecting portion 72 are connected so that each buffer portion 71 and the connecting portion 72 are connected as a whole, which facilitates the assembly of the shell 4 and the buffer structure 7 .

[0125] Optionally, the buffer parts 71 are interconnected so that the buffer structure 7 forms a hollow cylinder with a one-way opening, and the electrode assembly 5 is accommodated in the cavity of the hollow cylinder, which facilitates the assembly of the shell 4 and the buffer structure 7.

[0126] In some embodiments, Figure 6 and Fig.11 As shown, the buffer structure 7 further includes an insulating member 73 , which is disposed between the second side wall 422 and the electrode assembly 5 , and the second side wall 422 is insulated from the electrode assembly 5 by the insulating member 73 .

[0127] In these embodiments, the buffer structure 7 also includes an insulating member 73, which is disposed between the second side wall 422 and the electrode assembly 5. The second side wall 422 is insulated from the electrode assembly 5 by the insulating member 73, thereby improving the insulation reliability between the electrode assembly 5 and the shell 4. The second side wall 422 is insulated from the electrode assembly 5 by the insulating member 73. The insulating member 73 has a simple structure and low material cost, thereby reducing the preparation cost of the battery cell 3.

[0128] Optionally, the insulating member 73 may be a flexible insulating material, and the insulating member 73 is connected to the buffer portion 71 to facilitate adjustment of the spacing of the buffer portion 71 and reduce the difficulty of assembling the buffer structure 7 and the housing 4. Exemplarily, the insulating member 73 is an insulating film material.

[0129] Optionally, the insulating member 73 may be a hard insulating material, and the insulating member 73 is connected to the buffer portion 71 to improve the structural strength of the buffer structure 7. Exemplarily, the insulating member 73 is an insulating plate.

[0130] Optionally, the insulating member 73 and the connecting portion 72 are of the same insulating structure to reduce the difficulty of preparing the buffer structure 7 .

[0131] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell according to an embodiment of the first aspect.

[0132] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery of the embodiment of the second aspect above.

[0133] In some embodiments, Figures 1 to 11As shown, the battery cell 3 includes a shell 4, an electrode assembly 5 and a buffer structure 7, the shell 4 includes a bottom wall 41 and a side wall 42 connected to the bottom wall 41, the bottom wall 41 and the side wall 42 enclose a chamber, the side wall 42 includes two first side walls 421 arranged opposite to each other along a first direction X and two second side walls 422 arranged opposite to each other along a second direction Y, the surface area of ​​the first side wall 421 is greater than or equal to the surface area of ​​the second side wall 422, the first direction X and the second direction Y intersect; the electrode assembly 5 is accommodated in the chamber; the buffer structure 7 is accommodated in the chamber, and the buffer structure 7 includes a buffer portion 71 and a connecting portion The buffer portion 71 is disposed between the electrode assembly 5 and the two first side walls 421, the connecting portion 72 is connected between the two buffer portions 71, the connecting portion 72 is located between the electrode assembly 5 and the bottom wall 41, the buffer portion 71 includes a first contact member 711, a telescopic member 712 and a second contact member 713, the first contact member 711 contacts the electrode assembly 5, the telescopic member 712 is disposed between the second contact member 713 and the first contact member 711, the second contact member 713 is disposed between the telescopic member 712 and the side wall 42, the first contact member 711 is a hard material, and the telescopic member 712 is disposed along the first contact member 711. The contact member 711 is retractable in the thickness direction so that the distance between the first contact member 711 and the side wall 42 can be adjusted. The retractable member 712 includes a plurality of retractable units 8 arranged at intervals. The retractable units 8 extend obliquely along the thickness direction of the buffer portion 71 between the first contact member 711 and the second contact member 713, and / or the retractable unit 8 includes a first segment 81, a second segment 82 and a third segment 83 arranged along the thickness direction of the buffer portion 71. The first segment 81 is obliquely arranged along the thickness direction of the buffer portion 71 between the second segment 82 and the first contact member 711. The two first segments 83 are arranged along the thickness direction of the buffer portion 71. 81 are respectively connected to the two ends of the second segment 82, the third segment 83 is obliquely arranged between the second segment 82 and the second contact member 713 along the thickness direction of the buffer portion 71, the two third segments 83 are respectively connected to the two ends of the second segment 82, the buffer portion 71 is arranged between the second side wall 422 and the electrode assembly 5, and the second side wall 422 is insulated from the electrode assembly 5 by the buffer portion 71, or the buffer structure 7 also includes an insulating member 73, the insulating member 73 is arranged between the second side wall 422 and the electrode assembly 5, and the second side wall 422 is insulated from the electrode assembly 5 by the insulating member 73.

[0134] In the scheme of the embodiment of the present application, the battery cell 3 includes a shell 4, an electrode assembly 5 and a buffer structure 7. The electrode assembly 5 is accommodated in the shell 4, and the shell 4 serves to accommodate and protect the electrode assembly 5; the buffer structure 7 is arranged between the electrode assembly 5 and the side wall 42 of the shell 4, and the buffer structure 7 includes a buffer portion 71, and the buffer portion 71 includes a first contact piece 711 and a telescopic piece 712. The first contact piece 711 contacts the electrode assembly 5, and the first contact piece 711 serves to support the electrode assembly 5; the telescopic piece 712 is arranged between the first contact piece 711 and the side wall 42, so that when the electrode assembly 5 expands, the telescopic piece 712 can undergo elastic deformation, and the distance between the first contact piece 711 and the side wall 42 is adjustable. The buffer portion 71 absorbs and buffers the deformation of the electrode assembly 5, thereby reducing the compression of the electrode assembly 5. The risk of damage is reduced, and the reliability of the battery cell 3 is improved; and the first contact piece 711 is a hard material, and the first contact piece 711 plays a role in supporting the battery cell 3. When the battery cell assembly expands and squeezes the first contact piece 711, the pressure is dispersed to the entire first contact piece 711, and the first contact piece 711 squeezes the telescopic piece 712 as a whole, so that the buffer part 71 is uniformly stressed as a whole, so as to improve the problem that when the buffer part 71 is made of a flexible material, the local force is uneven, resulting in stress concentration in some areas of the electrode assembly 5, resulting in lithium deposition on the pole piece, and it can also improve the problem that when the buffer part 71 is made of a flexible material, the buffer part 71 is unevenly stressed, resulting in excessive force on the side wall 42 of the shell 4 and deformation, resulting in difficulty in controlling the external dimensions of the battery cell 3 and reduced flatness of the large surface, thereby improving the grouping efficiency of the battery 2 to improve the performance of the battery 2.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: The shell comprises a bottom wall and a side wall connected to the bottom wall, wherein the bottom wall and the side wall enclose a chamber; an electrode assembly, contained in the chamber; A buffer structure is accommodated in the chamber, the buffer structure includes a buffer portion, the buffer portion is arranged between the electrode assembly and the side wall, the buffer portion includes a first contact piece and a telescopic piece, the first contact piece is in contact with the electrode assembly, the telescopic piece is arranged between the side wall and the first contact piece, the first contact piece is made of a hard material, and the telescopic piece is telescopically arranged along the thickness direction of the first contact piece so that the distance between the first contact piece and the side wall can be adjusted.

2. The battery cell according to claim 1, characterized in that: The two buffer parts are arranged on both sides of the electrode assembly.

3. The battery cell according to claim 2, characterized in that: The buffer structure further includes a connecting portion, which is connected between the two buffer portions and is located between the electrode assembly and the bottom wall.

4. The battery cell according to claim 1, characterized in that: The buffer portion further includes a second contact piece, and the second contact piece is arranged between the telescopic piece and the side wall.

5. The battery cell according to claim 4, characterized in that: The telescopic member comprises a plurality of telescopic units arranged at intervals. The telescopic unit extends obliquely along the thickness direction of the buffer portion between the first contact piece and the second contact piece, and / or the telescopic unit includes a first segment, a second segment and a third segment arranged along the thickness direction of the buffer portion, the first segment is obliquely arranged along the thickness direction of the buffer portion between the second segment and the first contact piece, two first segments are respectively connected to the two ends of the second segment, the third segment is obliquely arranged along the thickness direction of the buffer portion between the second segment and the second contact piece, and two third segments are respectively connected to the two ends of the second segment.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The side wall comprises two first side walls arranged opposite to each other along a first direction and two second side walls arranged opposite to each other along a second direction, the surface area of ​​the first side wall is greater than or equal to the surface area of ​​the second side wall, and the first direction intersects with the second direction. The buffer portion is disposed between the first side wall and the electrode assembly.

7. The battery cell according to claim 6, characterized in that: The buffer portion is disposed between the second side wall and the electrode assembly, and the second side wall is insulated from the electrode assembly by the buffer structure.

8. The battery cell according to claim 6, characterized in that: The buffer structure further includes an insulating member, which is disposed between the second side wall and the electrode assembly, and the second side wall is insulated from the electrode assembly by the insulating member.

9. A battery, characterized in that: The battery cell comprises the battery cell as claimed in claim 8.

10. An electrical device, characterized in that: A battery comprising the battery as claimed in claim 9.

Images