Housing, battery cell, battery, and electric device

Abstract

The embodiment of the utility model provides a shell, a single battery, a battery and a power utilization device, the shell comprises a shell body and an expansion part, the shell body is provided with a containing cavity, the containing cavity is used for containing an electrode assembly of the single battery, the shell body is provided with a first end and a second end which are back to back in a first direction, the first end is provided with a first opening, and the first opening is communicated with the containing cavity; the first direction is the depth direction of the shell body; the expansion part is connected to the first end and surrounds the first opening, and the size of the part, away from the first end, of the expansion part is larger than that of the part, close to the first end, of the expansion part in the direction perpendicular to the first direction. The energy density of the battery monomer can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and more specifically, to a housing, a battery cell, a battery, and an electrical device. Background Art

[0002] Battery monomers are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] In the development of battery technology, how to improve the energy density of battery cells is a research direction in battery technology. Utility Model Content

[0004] The present application provides a housing, a battery cell, a battery and an electrical device, which can improve the energy density of the battery cell.

[0005] An embodiment of the present application provides a shell, which includes a shell body and an expansion portion, the shell body having a accommodating cavity, the accommodating cavity being used to accommodate an electrode assembly of a battery cell, the shell body having a first end and a second end opposite to each other in a first direction, the first end having a first opening, the first opening being connected to the accommodating cavity, and the first direction being the depth direction of the shell body; the expansion portion is connected to the first end and surrounds the first opening, and along a direction perpendicular to the first direction, the size of a portion of the expansion portion away from the first end is larger than the size of a portion of the expansion portion close to the first end.

[0006] In the above technical scheme, the shell of the embodiment of the present application is provided with an expansion part, and along the direction perpendicular to the first direction, the size of the part of the expansion part away from the first end is larger than the size of the part of the expansion part close to the first end. The electrode assembly enters the shell through the expansion part. The expansion part can reduce the scratching phenomenon between the packaging film of the electrode assembly and the edge of the shell. Compared with the expansion part, the shell body is smaller in size in the direction perpendicular to the first direction, that is, it is in a contracted state relative to the expansion part, thereby improving the energy density of the battery cell.

[0007] In some embodiments, along the arrangement direction from the second end to the first end, at least a portion of the expansion portion gradually tilts outward.

[0008] In the above technical solution, the expansion portion is set to be inclined, which is not only easy to manufacture, but also can play a good guiding role for the electrode assembly and facilitate the entry of the electrode assembly.

[0009] In some embodiments, along the arrangement direction from the second end to the first end, the entire expansion portion surrounding the first opening is inclined outward.

[0010] In the above technical solution, the entire expansion portion is set to be inclined outward, which further reduces the scratching phenomenon caused by the interference between the packaging film of the electrode assembly and the edge of the shell, thereby reducing the lithium plating phenomenon and increasing the service life of the battery cell.

[0011] In some embodiments, the shell further includes a positive electrode cover, the second end has a second opening, and the positive electrode cover is connected to the second end and covers the second opening.

[0012] In the above technical solution, a positive electrode cover is provided, and the positive electrode of the battery cell is led out by the positive electrode cover, thereby improving the convenience of using the shell.

[0013] In some embodiments, the shell body and the expansion portion are connected in an integrally formed manner.

[0014] In the above technical solution, the shell body and the expansion part are manufactured in an integrally formed manner, so the connection process between the two can be omitted, thereby improving the production efficiency of the shell.

[0015] In some embodiments, an inclination angle of the expansion portion relative to the first direction is α, and α satisfies: 30°≤α≤60°.

[0016] In the above technical solution, the inclination angle of the expansion portion relative to the first direction is limited to greater than or equal to 30°, which makes it convenient for the electrode assembly to enter the accommodating cavity through the expansion portion, thereby reducing the probability of solid particles being generated due to scratching between the two; the inclination angle α of the expansion portion relative to the first direction X is limited to less than or equal to 60°, which makes it convenient to perform edge sealing on the expansion portion when forming a battery cell, that is, to fold the expansion portion inward.

[0017] In some embodiments, α satisfies: 40°≤α≤50°.

[0018] In the above technical solution, the inclination angle α of the expansion portion relative to the first direction X is limited to greater than or equal to 40°, which further facilitates the electrode assembly to enter the accommodating cavity through the expansion portion, reducing the probability of solid particles generated due to scraping between the two; the inclination angle α of the expansion portion relative to the first direction is limited to less than or equal to 50°, which further facilitates the subsequent edge sealing treatment of the expansion portion.

[0019] In some embodiments, the maximum dimension of the expansion portion along the first direction is h1, and h1 satisfies: 2mm≤h1≤4mm.

[0020] In the above technical solution, the maximum size of the expansion portion along the first direction X is limited to be greater than or equal to 2 mm, which facilitates the subsequent edge sealing of the expansion portion when forming a battery cell; the maximum size of the expansion portion along the first direction X is limited to be less than or equal to 4 mm, which can reduce the wrinkling phenomenon of the expansion portion during edge sealing.

[0021] In some embodiments, h1 satisfies: 2mm≤h1≤3mm.

[0022] In the above technical solution, the maximum size of the expansion portion along the first direction is limited to be less than or equal to 3 mm, which can further reduce the wrinkling phenomenon of the expansion portion during edge sealing.

[0023] In some embodiments, the accommodating cavity of the shell is cylindrical.

[0024] In the above technical solution, for battery cells with cylindrical accommodating cavities, in order to reduce interference when the electrode assembly is inserted into the shell, the outer shell needs to be larger in size in the entire circumferential direction, resulting in lower energy density. Therefore, by setting the shell in this way, the energy density of the battery cell can be significantly improved.

[0025] In the second aspect, an embodiment of the present application also provides a battery cell, including the above-mentioned shell, electrode assembly and end cover, wherein the electrode assembly is located in the accommodating cavity; the end cover is connected to the shell and covers the first opening; wherein the expansion portion is configured to fold inwardly and abut against the side of the end cover facing away from the electrode assembly.

[0026] The expansion part is abutted against the side of the end cover away from the electrode assembly, that is, the expansion part is used for sealing, which can make full use of the expansion part to facilitate the connection between the end cover and the shell, while also reducing the space occupied by the expansion part due to its outward inclination, thereby improving the energy density of the battery cell.

[0027] In some embodiments, at least a portion of the housing body and the end cap is configured as a negative electrode of a battery cell.

[0028] In the above technical solution, at least part of the shell body and the end cover are configured as the negative electrode of the battery cell, and the shell body and the end cover do not need to be insulated from each other, which reduces the steps of insulation treatment and facilitates manufacturing.

[0029] In some embodiments, the battery cells are cylindrical battery cells.

[0030] In the above technical solution, for cylindrical battery cells, in order to reduce interference when the electrode assembly is put into the shell, the size of its shell needs to be enlarged in the entire circumferential direction, resulting in lower energy density. Therefore, using the shell in the cylindrical battery cell can significantly improve the energy density of the cylindrical battery cell.

[0031] In a third aspect, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.

[0032] In a fourth aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery, and the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0034] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0035] Figure 2 A schematic diagram of the exploded structure of a battery provided in some embodiments of the present application;

[0036] Figure 3 A schematic diagram of the structure of a housing provided in some embodiments of the present application;

[0037] Figure 4 for Figure 3 A schematic diagram of the structure of the housing shown at another angle;

[0038] Figure 5 for Figure 4 A cross-sectional view of the shell shown at AA;

[0039] Figure 6 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0040] Figure 7 for Figure 6 A cross-sectional view of the battery cell shown at BB;

[0041] Figure 8 for Figure 7 Enlarged view at C.

[0042] The reference numerals of the specific embodiments are as follows:

[0043] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Battery cell; 6. Box;

[0044] 7. Shell;

[0045] 71, shell body; 711, accommodating cavity; 712, first end; 713, second end; 714, first opening; 715, second opening;

[0046] 72. Expansion Department;

[0047] 73. positive electrode cover;

[0048] 8. Electrode assembly;

[0049] 9. End cap;

[0050] X, first direction. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0053] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0054] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0056] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0057] The term "plurality" used in the present application refers to two or more (including two).

[0058] 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.

[0059] 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.

[0060] 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 relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. 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 coating area and a positive electrode ear connected to the positive coating area. The positive coating area 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 cell 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 electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area, and the negative electrode coating area is coated with a negative electrode active material layer, and the negative electrode tab is not coated with a negative electrode active material layer. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.

[0061] During the manufacturing process of battery cells, the electrode assembly needs to go through the shelling process, that is, putting the electrode assembly into the shell. If the size difference between the shell and the electrode assembly is not big, it will cause the outer packaging film of the electrode assembly to easily scrape against the edge of the shell during the shelling process, resulting in the generation of solid particles, which is easy to cause lithium deposition and shorten the service life of the battery cell.

[0062] To alleviate this phenomenon, the size of the housing is usually made larger, thus making the energy density of the battery cell lower.

[0063] In view of this, the present application provides a shell, in which an expansion portion is provided, and along a direction perpendicular to the first direction, the size of the portion of the expansion portion away from the first end is larger than the size of the portion of the expansion portion close to the first end. The electrode assembly enters the shell through the expansion portion, and the expansion portion can reduce the scratching phenomenon between the packaging film of the electrode assembly and the edge of the shell. Compared with the expansion portion, the shell body is smaller in size in the direction perpendicular to the first direction, that is, it is in a contracted state relative to the expansion portion, thereby improving the energy density of the battery cell.

[0064] The housing described in the embodiments of the present application is suitable for a battery cell, a battery, and an electrical device using the battery.

[0065] 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.

[0066] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0067] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0068] like Figure 1 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0069] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0070] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve 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.

[0071] Figure 2 Schematic diagram of the exploded structure of a battery provided for some embodiments of the present application.

[0072] like Figure 2 As shown, the battery 2 includes a box body 6 and a battery cell 5. The box body 6 has a receiving space, and the battery cell 5 is arranged in the receiving space.

[0073] In the battery 2, the battery cell 5 can be one or more. If there are more than one battery cell 5, the battery cells 5 can be connected in series, in parallel or in mixed connection. Mixed connection means that the battery cells 5 are connected in series and in parallel. The battery cells 5 can be directly connected in series, in parallel or in mixed connection, and then the whole formed by the battery cells 5 is fixed to the box 6; of course, the battery cells 5 can be connected in series, in parallel or in mixed connection to form a battery module, and then the battery modules are connected in series, in parallel or in mixed connection to form a whole and fixed to the box 6. The battery can also include other structures. For example, the battery can also include a converging component for realizing electrical connection between the battery cells.

[0074] Each battery cell may be a secondary battery or a primary battery; the battery cell may be cylindrical, flat, rectangular or in other shapes.

[0075] Figure 3 A schematic diagram of the structure of a housing provided in some embodiments of the present application; Figure 4 for Figure 3 A schematic diagram of the structure of the housing shown at another angle; Figure 5 for Figure 4 A cross-sectional view of the housing is shown at AA.

[0076] like Figure 3-Figure 5As shown, the present application also provides a shell 7, which includes a shell body 71 and an expansion portion 72. The shell body 71 has a accommodating cavity 711, and the accommodating cavity 711 is used to accommodate the electrode assembly of the battery cell 5. The shell body 71 has a first end 712 and a second end 713 opposite to each other in a first direction X. The first end 712 has a first opening 714, and the first opening 714 is connected to the accommodating cavity 711. The first direction X is the depth direction of the shell body 71; the expansion portion 72 is connected to the first end 712 and surrounds the first opening 714. Along the direction perpendicular to the first direction X, the size of the portion of the expansion portion 72 away from the first end 712 is larger than the size of the portion of the expansion portion 72 close to the first end 712.

[0077] The housing 7 of the embodiment of the present application can be used for cylindrical battery cells or square-shell battery cells.

[0078] The depth direction of the shell body 71 in the embodiment of the present application refers to the direction in which the electrode assembly enters. Exemplarily, when the shell body 71 is applied to a cylindrical battery cell, the depth direction of the shell body 71 is the axial direction of the shell body 71 .

[0079] The second end 713 of the embodiment of the present application may be closed, or may have an opening but not be closed.

[0080] The expansion portion 72 of the embodiment of the present application can be connected to the shell body 71 by welding or integral molding.

[0081] The expansion portion 72 of the embodiment of the present application is arranged in an annular shape, and the size of the portion of the expansion portion 72 away from the first end 712 is larger than the size of the portion of the expansion portion 72 close to the first end 712. For example, at least part of the expansion portion 72 may have an L-shaped cross section at AA, and the lower end of the L-shaped structure is connected to the shell body 71, and the upper end is a free end. For another example, at least part of the expansion portion 72 may have a stepped cross section at AA, and the lower end of the stepped structure is connected to the shell body 71, and the upper end is a free end.

[0082] The shell 7 of the embodiment of the present application is provided with an expansion portion 72. Along the direction perpendicular to the first direction X, the size of the portion of the expansion portion 72 away from the first end 712 is larger than the size of the portion of the expansion portion 72 close to the first end 712. The electrode assembly is inserted into the shell through the expansion portion 72. The expansion portion 72 can reduce the scratching phenomenon between the packaging film of the electrode assembly and the edge of the shell 7. Compared with the expansion portion 72, the shell body 71 is smaller in size in the direction perpendicular to the first direction X, that is, it is in a contracted state relative to the expansion portion 72, thereby improving the energy density of the battery cell 5.

[0083] In some embodiments, along the arrangement direction from the second end 713 to the first end 712 , at least a portion of the expansion portion 72 gradually tilts outward.

[0084] In the entire expansion portion 72, part of the expansion portion 72 may be inclined outward, while another part of the expansion portion 72 may maintain the same extension trend as the shell body 71 along the arrangement direction from the second end 713 to the first end 712; or the entire expansion portion 72 may be inclined outward. Inclining outward means extending outward in a direction away from the accommodating cavity 711. When the shell body 71 is used in a cylindrical battery cell, inclining outward means inclining in a direction away from the axis of the shell body 71.

[0085] The expansion portion of the embodiment of the present application may be inclined in a curved shape or in a linear shape along the arrangement direction from the second end 713 to the first end 712 .

[0086] Setting the expansion portion 72 to be inclined is not only easy to manufacture, but also can provide a good guide for the electrode assembly, facilitating the entry of the electrode assembly.

[0087] In some embodiments, along the arrangement direction from the second end 713 to the first end 712 , the entire expansion portion 72 surrounding the first opening 714 is inclined outward.

[0088] The expansion portion 72 of the embodiment of the present application is in a trumpet shape.

[0089] Setting the entire expansion portion 72 to be inclined outward further reduces the scratching phenomenon caused by the interference between the packaging film of the electrode assembly 8 and the edge of the shell 7, thereby reducing the lithium deposition phenomenon and increasing the service life of the battery cell 5.

[0090] In some embodiments, the housing 7 further includes a positive electrode cover 73 . The second end 713 has a second opening 715 . The positive electrode cover 73 is connected to the second end 713 and covers the second opening 715 .

[0091] The positive electrode cover 73 and the shell body 71 in the embodiment of the present application can be connected by welding or bonding.

[0092] A positive electrode cover 73 is provided, and the positive electrode of the battery cell 5 is led out by the positive electrode cover 73 , so as to improve the convenience of using the housing 7 .

[0093] In some embodiments, the shell body 71 and the expansion portion 72 are connected in an integrally formed manner.

[0094] Optionally, the expansion portion 72 is manufactured by a rolling process.

[0095] The shell body 71 and the expansion portion 72 are manufactured in an integrally formed manner, so that the connection process between the two can be omitted, thereby improving the production efficiency of the shell 7.

[0096] Please continue reading Figure 5In some embodiments, the inclination angle of the expansion portion 72 relative to the first direction X is α, and α satisfies: 30°≤α≤60°.

[0097] Optionally, α is 30°, 40°, 45°, 50° or 60°.

[0098] Limiting the inclination angle α of the expansion portion 72 relative to the first direction X to be greater than or equal to 30° facilitates the electrode assembly 8 to enter the accommodating cavity 711 through the expansion portion 72, thereby reducing the probability of solid particles being generated due to scraping between the two. Limiting the inclination angle α of the expansion portion 72 relative to the first direction X to be less than or equal to 60° facilitates the subsequent edge sealing of the expansion portion 72 when forming a battery cell, that is, folding the expansion portion 72 inward.

[0099] In some embodiments, α satisfies: 40°≤α≤50°.

[0100] Optionally, α is 42°, 43°, 45° or 48°.

[0101] Limiting the inclination angle α of the expansion portion 72 relative to the first direction X to be greater than or equal to 40° further facilitates the electrode assembly 8 to enter the accommodating cavity 711 through the expansion portion 72, thereby reducing the probability of solid particles being generated due to scraping between the two; limiting the inclination angle α of the expansion portion 72 relative to the first direction X to be less than or equal to 50° further facilitates the subsequent edge sealing treatment of the expansion portion 72.

[0102] In some embodiments, the maximum dimension of the expansion portion 72 along the first direction X is h1, and h1 satisfies: 2 mm≤h1≤4 mm.

[0103] Optionally, h1 is 2 mm, 3 mm or 4 mm.

[0104] Limiting the maximum size of the expansion portion 72 along the first direction X to be greater than or equal to 2 mm facilitates the subsequent edge sealing of the expansion portion 72 when forming a battery cell; limiting the maximum size of the expansion portion 72 along the first direction X to be less than or equal to 4 mm can reduce the wrinkling phenomenon of the expansion portion 72 during edge sealing.

[0105] In some embodiments, h1 satisfies: 2mm≤h1≤3mm.

[0106] Optionally, h1 is 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm or 3mm.

[0107] Limiting the maximum dimension of the expansion portion 72 along the first direction X to be less than or equal to 3 mm can further reduce the wrinkling phenomenon of the expansion portion 72 during edge sealing.

[0108] In some embodiments, the accommodating cavity of the housing 7 is cylindrical.

[0109] For battery cells with cylindrical accommodating cavities, in order to reduce interference when the electrode assembly 8 is inserted into the shell, the outer shell needs to be larger in size in the entire circumferential direction, resulting in lower energy density. Therefore, by configuring the shell 7 in this way, the energy density of the battery cell can be significantly improved.

[0110] Figure 6 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application; Figure 7 for Figure 6 A cross-sectional view of the battery cell shown at BB; Figure 8 for Figure 7 Enlarged view at C.

[0111] like Figure 6-8 As shown, the present application also provides a battery cell 5, including the above-mentioned shell 7, electrode assembly 8 and end cover 9, the electrode assembly 8 is located in the accommodating cavity 711, the end cover 9 is connected to the shell 7 and covers the first opening 714; the expansion portion 72 is configured to fold inward and abut against the side of the end cover 9 facing away from the electrode assembly 8.

[0112] The end cap 9 refers to a component that covers the first opening 714 of the housing 7 to isolate the internal environment of the battery cell 5 from the external environment. Without limitation, the shape of the end cap 9 can be adapted to the shape of the housing 7 to match the housing 7. Optionally, the end cap 9 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 9 is not easily deformed when squeezed and collided, so that the battery cell 5 can have a higher structural strength and the safety performance can also be improved.

[0113] The housing 7 is a component used to cooperate with the end cap 9 to form an internal environment of the battery cell 5, wherein the formed internal environment can be used to accommodate the electrode assembly 8, electrolyte and other components. The housing 7 and the end cap 9 are independent components, and the internal environment of the battery cell 5 is formed by covering the first opening 714 with the end cap 9 at the first opening 714. Specifically, the shape of the housing 7 can be determined according to the specific shape and size of the electrode assembly 8.

[0114] The electrode assembly 8 is a component in the battery cell 5 where an electrochemical reaction occurs. One or more electrode assemblies 8 may be contained in the housing 7. The electrode assembly 8 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 8, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a pole ear.

[0115] The expansion portion 72 of the embodiment of the present application is folded inwards, and can be sealed by a rolling process, and then the expansion portion 72 is bonded to the end cover 9.

[0116] The expansion portion 72 is abutted against the side of the end cover 9 facing away from the electrode assembly 8, that is, the expansion portion 72 is used for sealing, which can fully utilize the expansion portion 72 to facilitate the connection between the end cover 9 and the shell 7, while also reducing the space occupied by the expansion portion 72 due to its outward inclination, thereby improving the energy density of the battery cell 5.

[0117] In some embodiments, at least a portion of the shell body 71 and the end cover 9 are configured as the negative electrode of the battery cell 5 .

[0118] When the housing 7 has a positive electrode cover 73 , part of the housing body 71 and the end cover 9 are configured as the negative electrode of the battery cell 5 .

[0119] At least part of the shell body 71 and the end cover 9 are configured as the negative electrode of the battery cell 5. The shell body 71 and the end cover 9 do not need to be insulated from each other, which reduces the steps of insulation treatment and facilitates manufacturing.

[0120] In some embodiments, the battery cell 5 is a cylindrical battery cell.

[0121] For cylindrical battery cells, in order to reduce interference when the electrode assembly 8 is inserted into the shell, the size of its shell needs to be enlarged in the entire circumferential direction, resulting in lower energy density. Therefore, using the shell 7 in the cylindrical battery cell can significantly improve the energy density of the cylindrical battery cell.

[0122] The embodiment of the present application further provides a battery 2, comprising the above-mentioned battery cell 5.

[0123] The embodiment of the present application also provides an electrical device, comprising the above-mentioned battery 2.

[0124] See also Figure 3-Figure 5The embodiment of the present application provides a shell 7, which includes a shell body 71 and an expansion portion 72. The shell body 71 has a housing cavity 711, which is used to accommodate the electrode assembly of the battery cell 5. The shell body 71 has a first end 712 and a second end 713 opposite to each other in a first direction X. The first end 712 has a first opening 714, which is connected to the housing cavity 711. The first direction X is the depth direction of the shell body 71. The expansion portion 72 is connected to the first end 712 and surrounds the first opening 714. In the direction perpendicular to the first direction X, the size of the portion of the expansion portion 72 away from the first end 712 is larger than the size of the portion of the expansion portion 72 close to the first end 712. Along the arrangement direction from the second end 713 to the first end 712, the entire expansion portion 72 surrounding the first opening 714 is inclined outward. The shell 7 also includes a positive electrode cover 73, the second end 713 has a second opening 715, and the positive electrode cover 73 is connected to the second end 713 and covers the second opening 715. The shell body 71 and the expansion part 72 are connected in an integrally formed manner. The inclination angle of the expansion part 72 relative to the first direction X is α, and α satisfies: 40°≤α≤50°. The maximum dimension of the expansion part 72 along the first direction X is h1, and h1 satisfies: 2mm≤h1≤3mm. The accommodating cavity of the shell 7 is cylindrical.

[0125] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0126] 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 it. 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 make equivalent replacements for some of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A housing, characterized in that: include: A shell body having a receiving cavity, the receiving cavity being used to receive an electrode assembly of a battery cell, the shell body having a first end and a second end opposite to each other in a first direction, the first end having a first opening, the first opening being connected to the receiving cavity, and the first direction being a depth direction of the shell body; An expansion portion is connected to the first end and surrounds the first opening. Along a direction perpendicular to the first direction, a size of a portion of the expansion portion away from the first end is larger than a size of a portion of the expansion portion close to the first end.

2. The housing according to claim 1, characterized in that Along the arrangement direction from the second end to the first end, at least a portion of the expansion portion gradually tilts outward.

3. The housing according to claim 2, characterized in that: Along the arrangement direction from the second end to the first end, the entire expansion portion surrounding the first opening is inclined outward.

4. The housing according to claim 1, characterized in that The shell further includes a positive electrode cover, the second end has a second opening, and the positive electrode cover is connected to the second end and covers the second opening.

5. The housing according to claim 1, characterized in that: The shell body and the expansion portion are connected in an integrally formed manner.

6. The housing according to any one of claims 2 to 5, characterized in that: The inclination angle of the expansion portion relative to the first direction is α, and α satisfies: 30°≤α≤60°.

7. The housing according to claim 6, characterized in that The α satisfies: 40°≤α≤50°.

8. The housing according to any one of claims 1 to 5, characterized in that: The maximum dimension of the expansion portion along the first direction is h1, and h1 satisfies: 2mm≤h1≤4mm.

9. The housing according to claim 8, characterized in that The h1 satisfies: 2mm≤h1≤3mm.

10. The housing according to claim 1, characterized in that The accommodating cavity of the shell is cylindrical.

11. A battery cell, characterized in that: include: The housing according to any one of claims 1 to 10; An electrode assembly, located in the accommodating cavity; An end cover connected to the housing and covering the first opening; Wherein, the expansion portion is configured to be folded inwardly and abut against a side of the end cover away from the electrode assembly.

12. The battery cell according to claim 11, characterized in that: At least a portion of the shell body and the end cover is configured as a negative electrode of the battery cell.

13. The battery cell according to claim 11, characterized in that: The battery cell is a cylindrical battery cell.

14. A battery, characterized in that: Comprising a battery cell as claimed in any one of claims 11 to 13.

15. An electrical device, characterized in that: Comprising a battery as claimed in claim 14, the battery is used to provide electrical energy.

Images