Battery monomer, battery and electric device

Abstract

The utility model belongs to the technical field of battery energy density, and particularly relates to a battery monomer, a battery and a power utilization device, the battery monomer comprises an electrode assembly and a shell, the electrode assembly is located in the shell, and the shell comprises a first side wall and a second side wall; a first arc-shaped part is connected between the first side wall and the second side wall, the first arc-shaped part and the edge of the electrode assembly are oppositely arranged, the wall surface, facing the electrode assembly, of the first arc-shaped part comprises a first arc-shaped surface and a second arc-shaped surface, and the two ends of the second arc-shaped surface are connected with the first arc-shaped surface in the length direction of the edge of the electrode assembly; the radius of the second arc surface is smaller than the radius of the first arc surface, so that the second arc surface can provide an avoiding space for the edge corresponding to the electrode assembly, the interference risk between the edge of the electrode assembly and the first arc part is reduced, an insulating plate can be omitted or thinned, the electrode assembly with a larger size can be installed in the shell, and the service life of the electrode assembly is prolonged. And the volume energy density of the battery monomer is improved.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] A battery includes one or more battery cells to meet different capacity usage requirements; however, in battery cell technology, how to improve the energy density of battery cells is an important research direction.

[0004] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Utility Model Content

[0005] The purpose of the embodiments of the present application is to provide a battery cell, a battery and an electrical device, including but not limited to improving the volume energy density of the battery cell.

[0006] The technical solution adopted in the embodiment of the present application is:

[0007] In a first aspect, a battery cell is provided, which includes an electrode assembly and a shell, wherein the electrode assembly is located in the shell, and the shell includes a first side wall and a second side wall; a first arc portion is connected between the first side wall and the second side wall, and the first arc portion is arranged opposite to the edge of the electrode assembly, and the wall surface of the first arc portion facing the electrode assembly includes a first arc surface and a second arc surface, and along the length direction of the edge of the electrode assembly, both ends of the second arc surface are connected to the first arc surface; the radius of the second arc surface is smaller than the radius of the first arc surface.

[0008] In the battery cell of the embodiment of the present application, the electrode assembly is installed in the shell, and a first arc portion is provided between the first side wall and the second side wall of the shell, and the first arc portion smoothly transitions to connect the first side wall and the second side wall, thereby reducing stress concentration, improving the structural strength of the shell, and facilitating the molding of the shell; in addition, the first arc portion is arranged opposite to the edge of the electrode assembly, and the wall surface of the first arc portion facing the electrode assembly includes a first arc surface and a second arc surface, and along the length direction of the edge of the electrode assembly, the two ends of the second arc surface are connected to the first arc surface, so that the second arc surface is arranged opposite to the edge of the electrode assembly, and the second arc surface The radius is smaller than that of the first arc surface, so that the second arc surface can provide an avoidance space for the edge of the electrode assembly, reducing the risk of interference between the edge of the electrode assembly and the first arc portion. In this way, the insulating plate can be omitted or the insulating plate can be thinned, so that a larger volume of electrode assembly can be installed in the outer shell, which is beneficial to improving the volume energy density of the battery cell; in addition, during the expansion process of the electrode assembly, the avoidance space provided by the second arc surface can also reduce the amount of interference between the electrode assembly and the first arc portion, reducing the risk of decarbonization and lithium precipitation of the electrode assembly due to interference with the first arc portion, which is beneficial to improving the charge and discharge performance of the battery cell.

[0009] In some embodiments, the wall surface of the first arc-shaped portion facing the electrode assembly further includes a first connecting surface, the first connecting surface is connected between the second arc surface and the first arc surface, and the first connecting surface is an arc surface.

[0010] By adopting the technical solution of this embodiment, the first arc surface and the second arc surface are connected through the arc surface, the structure of the first arc portion is regular, which facilitates the molding of the shell, is also beneficial to reduce stress concentration, and improves the structural strength of the shell.

[0011] In some embodiments, in the direction from the second arc surface to the first arc surface, the radius of the first connecting surface increases.

[0012] By adopting the technical solution of this embodiment, the first arc surface and the second arc surface are connected by a smooth transition through the first connecting surface, which can better reduce stress concentration, improve the structural strength of the shell, and facilitate the molding of the shell.

[0013] By adopting the technical solution of this embodiment, the first arc surface and the second arc surface are connected by a smooth transition through the first connecting surface, which can reduce stress concentration, improve the structural strength of the shell, and facilitate the molding of the shell.

[0014] In some embodiments, the midline of the second arc surface is connected to the midline of the first connecting surface, and the angle between the midline of the second arc surface and the midline of the first connecting surface is α, wherein 90°≤α≤180°.

[0015] By adopting the technical solution of this embodiment, the first connecting surface can be exposed outside the first arc-shaped portion, thereby facilitating the molding of the shell and also facilitating improving the structural strength of the shell.

[0016] In some embodiments, 120°≤α≤160°.

[0017] By adopting the technical solution of this embodiment, the first connecting surface can be tilted and smoothly connected to the first arc surface and the second arc surface, which is beneficial to reducing stress concentration and improving the structural strength of the shell.

[0018] In some embodiments, the radius of the first arc surface is R 1 , the radius of the second arc surface is R 2 , where 1 / 3≤R 2 / R 1 <1.

[0019] By adopting the technical solution of this embodiment, it is possible to simultaneously take into account the avoidance of the edges of the electrode assembly, the structural strength of the shell, and the convenience of shell molding.

[0020] In some embodiments, 0.5≤R 2 / R 1 ≤0.9.

[0021] By adopting the technical solution of this embodiment, the radius design of the second arc surface is more reasonable, which can better take into account the avoidance of the edges of the electrode assembly, the structural strength of the shell and the convenience of shell molding.

[0022] In some embodiments, the radius of the second arc surface is R 2 , where 0.3mm≤R 2 ≤5mm.

[0023] By adopting the technical solution of this embodiment, it is possible to simultaneously take into account the avoidance of the edges of the electrode assembly, the structural strength of the shell, and the convenience of shell molding.

[0024] In some embodiments, 0.5 mm ≤ R 2 ≤3mm.

[0025] By adopting the technical solution of this embodiment, the radius of the second arc surface is designed more reasonably, which can better take into account the avoidance of the edges of the electrode assembly, the structural strength of the shell and the convenience of shell molding.

[0026] In some embodiments, the dimension of the first side wall in the length direction of the edge of the electrode assembly is L 1 The distance between the end of the second arc surface and the end of the adjacent first side wall is L 2 , where 0<L 2 / L 1 ≤0.2.

[0027] By adopting the technical solution of this embodiment, the second arc surface can play a better role in avoiding the edges of the electrode assembly, and at the same time, the shell also has good structural strength.

[0028] In some embodiments, 0.05≤L 2 / L 1 ≤0.15.

[0029] By adopting the technical solution of this embodiment, the length design of the second arc surface is more reasonable, which can better take into account the avoidance of the edges of the electrode assembly and the structural strength of the shell.

[0030] In some embodiments, the dimension of the second arc surface in the length direction of the edge of the electrode assembly is L 3 , the length of the edge of the electrode assembly is L 4 , where L 3 ≥L 4 .

[0031] By adopting the technical solution of this embodiment, L 3 ≥L 4 The design makes the length of the second arc surface greater than the length of the edge of the electrode assembly, and the first arc portion can completely avoid the edge of the electrode assembly, with a good avoidance effect.

[0032] In some embodiments, the outer shell includes a shell and two end covers, and openings are provided on two end surfaces of the shell relatively distributed along a first direction, the electrode assembly is located in the shell, and the two end covers cover the two openings respectively; the two side walls of the shell relatively distributed along a second direction are first side walls, and the two side walls of the shell relatively distributed along a third direction are second side walls, a first arc portion is connected between the first side wall and the adjacent second side wall, and the first direction, the second direction and the third direction are perpendicular to each other.

[0033] By adopting the technical solution of this embodiment, the edges of the electrode assembly extending along the first direction are correspondingly provided with second arc surfaces for avoidance, and the avoidance effect of the electrode assembly is good; the outer shell adopts the structural form of a shell and two end covers, the structure is simple, and the assembly and sealing of the battery cell are simple.

[0034] In some embodiments, the electrode assembly includes a plurality of pole pieces, and the plurality of pole pieces are stacked along a third direction.

[0035] By adopting the technical solution of this embodiment, multiple pole pieces are stacked along the third direction, so that the electrode assembly has four edges extending along the second direction, and the second arc surfaces of the four first arc-shaped portions connected between the first side wall and the second side wall can be arranged opposite to the four edges, thereby providing avoidance space, reducing the risk of interference between the electrode assembly and the outer shell, and is beneficial to improving the volume energy density and charge and discharge performance of the battery cell.

[0036] In some embodiments, the outer shell includes a shell and an end cover, and the electrode assembly is located in the shell; one of the two end surfaces of the shell relatively distributed along a first direction is provided with an opening, and the end cover covers the opening; the side wall of the shell and the end cover arranged opposite to each other is a first side wall, the two side walls of the shell relatively distributed along a second direction are second side walls, and the two side walls of the shell relatively distributed along a third direction are third side walls; a first arc portion is connected between at least one second side wall and the side portion corresponding to the first side wall, and the first direction, the second direction and the third direction are perpendicular to each other.

[0037] By adopting the technical solution of this embodiment, the edges of the electrode assembly extending along the third direction are correspondingly provided with second arc surfaces for avoidance, and the avoidance effect of the electrode assembly is good; the outer shell adopts the structural form of a shell and an end cover, the structure is simple, and the assembly and sealing of the battery cell are simple.

[0038] In some embodiments, the electrode assembly is a winding structure, and the winding axis of the electrode assembly is parallel to the first direction; or, the electrode assembly is a winding structure, and the winding axis of the electrode assembly is parallel to the second direction; or, the electrode assembly includes multiple pole pieces, and the multiple pole pieces are stacked along the first direction.

[0039] By adopting the technical solution of this embodiment, the shell can meet the avoidance requirements of electrode assemblies of various structural forms and has a wide range of applications.

[0040] In some embodiments, the electrode assembly is a winding structure, the winding axis of the electrode assembly is parallel to the first direction, and the size of the electrode assembly in the second direction is W. 1 , the distance between the second arc surface and the adjacent third side wall is W 2 , where 1 / 15≤W 2 / W 1 ≤0.5.

[0041] By adopting the technical solution of this embodiment, the length of the second arc surface is reasonably designed, which can take into account both the structural strength of the shell and the avoidance of the edges of the electrode assembly.

[0042] In some embodiments, 0.1≤W 2 / W 1 ≤0.4.

[0043] By adopting the technical solution of this embodiment, 0.1≤W 2 / W 1 The design of ≤0.4 makes the length design of the second arc surface more reasonable, which can better take into account the structural strength of the shell and the avoidance of the edges of the electrode assembly.

[0044] In some embodiments, the electrode assembly is a winding structure, the winding axis of the electrode assembly is parallel to the first direction, and the distance between the second arc surface and the adjacent third side wall is W. 2 , where 3mm≤W 2 ≤8mm.

[0045] By adopting the technical solution of this embodiment, the length of the second arc surface is reasonably designed, which can take into account both the structural strength of the shell and the avoidance of the edges of the electrode assembly.

[0046] In some embodiments, 4 mm ≤ W 2 ≤6mm.

[0047] By adopting the technical solution of this embodiment, 4mm≤W 2 The design of ≤6mm makes the length design of the second arc surface more reasonable, which can better take into account the structural strength of the shell and the avoidance of the edges of the electrode assembly.

[0048] In some embodiments, the second side wall includes a straight portion and two arc-shaped connecting portions, and the two arc-shaped connecting portions are respectively connected between the opposite sides of the straight portion and the two third side walls; the first arc-shaped portion includes a straight line segment and two arc-shaped segments, the straight line segment is connected between the straight line portion and the first side wall, and the two arc-shaped segments are respectively connected between the two arc-shaped connecting portions and the first side wall; at least a portion of the wall surface of the straight line segment facing the electrode assembly forms a second arc surface, and at least a portion of the first arc surface is arranged on the wall surface of the arc segment facing the electrode assembly.

[0049] By adopting the technical solution of this embodiment, the straight portion and the third side wall are smoothly connected through the arc-shaped connecting portion, and the arc-shaped connecting portion and the first side wall are smoothly connected through the arc-shaped segment, which is beneficial to improving the structural reliability of the shell; in addition, the length of the second arc surface can be flexibly set to meet different needs.

[0050] In some embodiments, the electrode assembly is a winding structure, the winding axis of the electrode assembly is parallel to the first direction, and second arc portions are connected between the opposite sides of the first side wall and the two third side walls respectively; the wall surface of the second arc portion facing the electrode assembly includes a third arc surface for being arranged opposite to the vertex of the end of the electrode assembly, and the radius of the third arc surface is smaller than the radius of the first arc surface.

[0051] By adopting the technical solution of this embodiment, the third arc surface of the second arc portion can avoid the apex of the end of the electrode assembly. In this way, during the expansion process of the electrode assembly, the third arc surface can also provide avoidance space for the apex of the end of the electrode assembly, and can also reduce the interference between the electrode assembly and the second arc portion, thereby reducing the risk of decarbonization and lithium deposition caused by interference between the electrode assembly and the second arc portion, which is beneficial to improving the charge and discharge performance of the battery cell.

[0052] In some embodiments, the size of the electrode assembly in the second direction is W. 1 , the distance between the third arc surface and the straight line portion is W 3 , where 1 / 15≤W 3 / W 1 ≤0.5.

[0053] By adopting the technical solution of this embodiment, the length of the third arc surface is reasonably designed, which can take into account both the structural strength of the shell and the avoidance of the electrode assembly.

[0054] In some embodiments, 0.1≤W 3 / W 1 ≤0.4.

[0055] By adopting the technical solution of this embodiment, 0.1≤W 3 / W 1 The design of ≤0.4 makes the length design of the third arc surface more reasonable, which can better take into account the structural strength of the shell and the avoidance of the electrode assembly.

[0056] In some embodiments, the distance between the third arc surface and the straight line portion is W. 3 , where 3mm≤W 3 ≤8mm.

[0057] By adopting the technical solution of this embodiment, the length of the third arc surface is reasonably designed, which can take into account both the structural strength of the shell and the avoidance of the electrode assembly.

[0058] In some embodiments, 4 mm ≤ W 3 ≤6mm.

[0059] By adopting the technical solution of this embodiment, 4mm≤W 3 The design of ≤6mm makes the length design of the third arc surface more reasonable, which can better take into account the structural strength of the shell and the avoidance of the electrode assembly.

[0060] In some embodiments, the electrode assembly is a winding structure, and the winding axis of the electrode assembly is parallel to the second direction; when the battery cell is in use, the two second side walls are arranged up and down, and a first arc portion is connected between the opposite side portions of the first side wall and the two second side walls; the radius of the second arc surface of the first arc portion located on the upper side is smaller than the radius of the first arc surface of the first arc portion located on the lower side.

[0061] By adopting the technical solution of this embodiment, a first arc-shaped portion is connected between the first side wall and two second side walls arranged upper and lower. The two first arc-shaped portions can be respectively arranged opposite to the long straight lines on the upper and lower sides of the electrode assembly, and the radius of the second arc surface of the first arc-shaped portion located on the upper side is smaller than the radius of the first arc surface of the first arc-shaped portion located on the lower side, so that the second arc surface located on the upper side can better avoid the long straight line located on the upper side, and the avoidance effect of the electrode assembly is better.

[0062] In some embodiments, the outer wall surface of the first arc-shaped portion includes a fourth arc surface and a fifth arc surface that are connected to each other, the fourth arc surface is arranged opposite to the first arc surface, the fifth arc surface is arranged opposite to the second arc surface, and the radius of the fifth arc surface is smaller than the radius of the fourth arc surface; or, the outer wall surface of the first arc-shaped portion includes a plane, the plane intersects with the outer wall surface of the first side wall, and the plane intersects with the outer wall surface of the second side wall.

[0063] By adopting the technical solution of this embodiment, the outer wall surface of the first arc-shaped portion can adopt a variety of structures for flexible selection.

[0064] In a second aspect, a battery is provided, comprising a battery cell as described in the above embodiment.

[0065] The battery of the embodiment of the present application adopts the above-mentioned battery cell, the battery has a large volume energy density and good reliability in use, the battery has a long battery life, and the battery has good reliability in use.

[0066] In a third aspect, an electrical device is provided, comprising a battery as described in the above embodiment.

[0067] The electric device of the embodiment of the present application adopts the above-mentioned battery, which has a large volume energy density and good reliability, a long battery life of the electric device, and better performance of the electric device.

[0068] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art 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 these drawings without paying creative labor.

[0070] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0071] Figure 2 A schematic diagram of an exploded view of a battery provided for some embodiments of the present application.

[0072] Figure 3 A schematic diagram of an exploded view of a battery cell provided in some embodiments of the present application.

[0073] Figure 4 for Figure 3 A partial enlarged view of point A in the middle.

[0074] Figure 5 A schematic diagram of the structure of a battery cell with an end cover hidden in some other embodiments of the present application.

[0075] Figure 6 For along Figure 5 Sectional view along the midline BB.

[0076] Figure 7 for Figure 6 A partial enlarged view of point C in the middle.

[0077] Figure 8 Schematic diagram of the exploded view of battery cells provided for other embodiments of the present application.

[0078] Fig. 9 for Figure 8 The structural schematic diagram of the shell is shown in FIG.

[0079] Fig.10 for Fig. 9 A partial enlarged view of point D in the middle.

[0080] Fig.11 The housing provided in some other embodiments of the present application is Fig. 9 A partial enlarged view of point D in the middle.

[0081] Fig.12 for Figure 8 Schematic diagram of the structure of a battery cell shown.

[0082] Fig.13 For along Fig.12 Sectional view along line EE.

[0083] Fig.14 for Fig.13 A partial enlarged view of point F in the middle.

[0084] Fig.15 Schematic diagram of the exploded view of battery cells provided in some other embodiments of the present application.

[0085] Fig.16 for Fig.15 Schematic diagram of the structure of a battery cell shown.

[0086] Fig.17 For along Fig.16 Sectional view along line GG.

[0087] Fig.18 for Fig.17 A partial enlarged view of point H in the middle.

[0088] Fig.19 for Fig.15 A schematic structural diagram of a housing from one perspective is shown in FIG.

[0089] Fig. 20 for Fig.19 A partial enlarged view of point I in the middle.

[0090] Fig.21 for Fig.15 A schematic structural diagram of the housing from another perspective is shown in FIG.

[0091] Fig. 22 for Fig.21 A partial enlarged view of the J in the middle.

[0092] Fig.23 Schematic diagram of the exploded view of battery cells provided in some other embodiments of the present application.

[0093] Fig.24 for Fig.23 Schematic diagram of the structure of a battery cell shown.

[0094] Fig.25 For along Fig.24 Sectional view along line KK.

[0095] Fig.26 for Fig.25 A partial enlarged view of point M in the middle.

[0096] Fig. 27 for Fig.23 A schematic structural diagram of a housing from one perspective is shown in FIG.

[0097] Fig.28 for Fig.23 A schematic structural diagram of the housing from another perspective is shown in FIG.

[0098] Fig.29 for Fig.28 A local enlarged view of point N in the middle.

[0099] Fig.30 The battery cells provided in some embodiments of the present application are Fig.17 A partial enlarged view of point H in the middle.

[0100] Among them, the reference numerals in the figure are:

[0101] 1000, vehicle; 1100, battery; 1200, controller; 1300, motor; 100, battery cell; 10, electrode assembly; 10a, edge; 10b, arc line; 10c, long straight line; 11, pole piece; 12, pole ear; 20, shell; 21, end cover; 211, electrode terminal; 212, pressure relief mechanism; 22, shell; 221, first side wall; 222, second side wall; 2221, straight line portion; 2222, arc connecting portion; 22 3. Third side wall; 224. First arc-shaped portion; 2241. Straight line segment; 2242. Arc segment; 224a. First arc surface; 224b. Second arc surface; 224c. First connecting surface; 224d. Fourth arc surface; 224e. Fifth arc surface; 224f. Second connecting surface; 224g. Plane; 225. Second arc-shaped portion; 225a. Third arc surface; 30. Insulating film; 200. Box body; 210. First part; 220. Second part. DETAILED DESCRIPTION

[0102] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0103] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein 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 figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0104] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0105] Reference to "embodiments" herein means that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least some embodiments 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. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments in any suitable manner.

[0106] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may 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 article generally indicates that the associated objects before and after are in an "or" relationship.

[0107] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces). "Several" means one or more than one, unless otherwise clearly and specifically defined.

[0108] 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.

[0109] 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.

[0110] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0111] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. 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.

[0112] A battery usually includes one or more battery cells, and the number of battery cells can be set according to power demand. A battery cell includes a shell and an electrode assembly. The electrode assembly is arranged in the shell. The two adjacent side walls of the shell are usually connected by a smooth transition using an arc portion (also called an R angle) to reduce stress concentration and improve the structural strength of the shell; the edges of the electrode assembly are arranged opposite to the arc portion. In order to avoid interference between the edges of the electrode assembly and the arc portion to a certain extent, an insulating plate is usually used to pad the electrode assembly so that the edges of the electrode assembly are away from the arc portion, but the insulating plate will occupy a part of the internal space of the shell, thereby limiting the volume energy density of the battery cell.

[0113] Based on this, in order to improve the volume energy density of the battery cell, an embodiment of the present application provides a battery cell, wherein the electrode assembly is installed in a shell, and a first arc portion is provided between the first side wall and the second side wall of the shell, and the first arc portion smoothly transitions to connect the first side wall and the second side wall, thereby reducing stress concentration, improving the structural strength of the shell, and facilitating the molding of the shell; in addition, the first arc portion is arranged opposite to the edge of the electrode assembly, and the wall surface of the first arc portion facing the electrode assembly includes a first arc surface and a second arc surface, and along the length direction of the edge of the electrode assembly, the two ends of the second arc surface are connected to the first arc surface, so that the second arc surface and the edge of the electrode assembly are closely connected. The second arc surface is relatively arranged, and the radius of the second arc surface is smaller than that of the first arc surface, so that the second arc surface can provide an avoidance space for the edge of the electrode assembly, reducing the risk of interference between the edge of the electrode assembly and the first arc portion, so that the insulating plate can be omitted or the insulating plate can be thinned, so that a larger volume of electrode assembly can be installed in the outer shell, which is beneficial to improving the volume energy density of the battery cell; in addition, during the expansion process of the electrode assembly, the avoidance space provided by the second arc surface can also reduce the amount of interference between the electrode assembly and the first arc portion, reducing the risk of decarbonization and lithium precipitation of the electrode assembly due to interference with the first arc portion, which is beneficial to improving the charge and discharge performance of the battery cell.

[0114] The battery cells, batteries and electrical devices according to the embodiments of the present application are described below.

[0115] The electric device of the embodiment of the present application may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, 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, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric device may also refer to an energy storage device for storing electric energy, such as an energy storage container, an energy storage cabinet, etc.

[0116] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0117] Reference Figure 1 The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 1100 is provided inside the vehicle 1000. The battery 1100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 1100 may be used to power the vehicle 1000. For example, the battery 1100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 1200 and a motor 1300. The controller 1200 is used to control the battery 1100 to power the motor 1300, for example, to meet the power requirements for starting, navigating and driving the vehicle 1000.

[0118] In some embodiments of the present application, the battery 1100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0119] In some embodiments, reference Figure 2 The battery 1100 includes a box body 200 and a battery cell 100, and the battery cell 100 is accommodated in the box body 200. The box body 200 is used to provide an accommodating space for the battery cell 100, and the box body 200 can adopt a variety of structures.

[0120] For example, the box body 200 may include a first part 210 and a second part 220, the first part 210 and the second part 220 cover each other, and the first part 210 and the second part 220 jointly define a storage space for accommodating the battery cell 100. The second part 220 may be a hollow structure with one end open, and the first part 210 may be a plate-like structure, and the first part 210 covers the open side of the second part 220, so that the first part 210 and the second part 220 jointly define a storage space; the first part 210 and the second part 220 may also be hollow structures with one side open, and the open side of the first part 210 covers the open side of the second part 220. Of course, the box body 200 formed by the first part 210 and the second part 220 may be in various shapes, such as a cylinder, a cuboid, etc.

[0121] In the battery 1100 , there may be a plurality of battery cells 100 , and the plurality of battery cells 100 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 100 are connected in series and in parallel.

[0122] In some embodiments, multiple battery cells 100 can be directly connected in series, parallel or hybrid, and then the whole formed by the multiple battery cells 100 is accommodated in the box 200; of course, the battery 1100 can also be a battery module formed by connecting multiple battery cells 100 in series, parallel or hybrid, and then the multiple battery modules are connected in series, parallel or hybrid to form a whole and accommodated in the box 200. The battery 1100 can also include other structures, for example, the battery 1100 can also include a busbar component for realizing electrical connection between multiple battery cells 100.

[0123] Each battery cell 100 may be a secondary battery cell or a primary battery cell, or a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell. The battery cell 100 may be cylindrical, flat, rectangular, or in other shapes.

[0124] In some embodiments, the battery 1100 may not include the housing 200 , but a plurality of battery cells 100 may be electrically connected and formed into a whole through necessary fixing structures and then assembled into an electrical device.

[0125] The following combination Figures 3 to 30 A battery cell 100 according to an embodiment of the present application is described.

[0126] For ease of understanding and description, the embodiments provided in this application are described using only a rectangular parallelepiped battery cell 100 . It should be understood that the embodiments provided in this application are also applicable to a cylindrical or prismatic battery cell 100 .

[0127] See also Figures 3 to 20As shown, the battery cell 100 has a height direction, a length direction and a width direction, and the shell 20 defines the outer structure of the battery cell 100. The height direction of the shell 20 may be the height direction of the battery cell 100, the length direction of the shell 20 is the length direction of the battery cell 100, and the width direction of the shell 20 is the width direction of the battery cell 100.

[0128] For example, see Figures 3 to 7 As shown, the height direction of the battery cell 100 can refer to the Z direction in the figure, the width direction of the battery cell 100 can refer to the Y direction in the figure, and the length direction of the battery cell 100 can refer to the X direction in the figure.

[0129] For example, see Figures 8 to 22 As shown, the height direction of the battery cell 100 can refer to the X direction in the figure, the width direction of the battery cell 100 can refer to the Y direction in the figure, and the length direction of the battery cell 100 can refer to the Z direction in the figure.

[0130] For example, see Figures 23 to 29 As shown, the height direction of the battery cell 100 can refer to the Y direction in the figure, the width direction of the battery cell 100 can refer to the X direction in the figure, and the length direction of the battery cell 100 can refer to the Z direction in the figure.

[0131] See also Figures 3 to 7 As shown, in some embodiments of the present application, a battery cell 100 is provided, which includes an electrode assembly 10 and a shell 20, the electrode assembly 10 is located in the shell 20, and the shell 20 includes a first side wall 221 and a second side wall 222; a first arc portion 224 is connected between the first side wall 221 and the second side wall 222, the first arc portion 224 is arranged opposite to the edge 10a of the electrode assembly 10, and the wall surface of the first arc portion 224 facing the electrode assembly 10 includes a first arc surface 224a and a second arc surface 224b, along the length direction of the edge 10a of the electrode assembly 10, the first arc surface 224a is connected at both ends of the second arc surface 224b; the radius of the second arc surface 224b is smaller than the radius of the first arc surface 224a.

[0132] The outer shell 20 refers to a shell structure with a space inside to accommodate and protect the electrode assembly 10. The outer shell 20 can be made of a material with a certain hardness and strength, so that the outer shell 20 is not easily deformed when squeezed or collided, so that the battery cell 100 can have a higher structural strength and improved reliability. The outer shell 20 can be made of a variety of materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The outer shell 20 can be a variety of structures.

[0133] In some examples, the housing 20 may be a sealed structure or a non-sealed structure. As an example, when the housing 20 is a sealed structure, the housing 20 may protect the electrode assembly 10 and prevent leakage of electrolyte. When the housing 20 is a non-sealed structure, the housing 20 may protect the electrode assembly 10, and a sealing bag may be included between the housing 20 and the electrode assembly 10, and the sealing bag is used to encapsulate the electrode assembly 10 and the electrolyte. Specifically, the sealing bag may be a bag-shaped insulating member or an aluminum-plastic film.

[0134] For example, see Figure 3 As shown, the housing 20 includes a housing 20 and an end cap 21. The end cap 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 100 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 22 to match the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 is not easily deformed when squeezed and collided, so that the battery cell 100 can have a higher structural strength and the reliability performance can also be improved. The material of the end cap 21 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0135] The shell 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 100, wherein the formed internal environment can be used to accommodate the electrode assembly 10. The shell 22 and the end cap 21 can be independent components, and an opening can be set on the shell 22, and the internal environment of the battery cell 100 is formed by covering the opening with the end cap 21 at the opening. Without limitation, the end cap 21 and the shell 22 can also be integrated; the end cap 21 and the shell 22 can form a common connection surface before other components are put into the shell, and when the interior of the shell 22 needs to be encapsulated, the end cap 21 covers the shell 22. The shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 10. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The number of end caps 21 can be one or more, and for example, the number of end caps 21 is one or two.

[0136] For example, see Figure 3 , Figure 8 , Fig.15 and Fig.23 As shown, the shape of the shell 22 defines the shape of the outer shell 20 , the height direction of the shell 22 is the height direction of the outer shell 20 , the width direction of the shell 22 is the width direction of the outer shell 20 , and the length direction of the shell 22 is the length direction of the outer shell 20 .

[0137] The electrode assembly 10 is a component where an electrochemical reaction occurs in the battery cell 100. One or more electrode assemblies 10 may be contained in the housing 20.

[0138] For example, the electrode assembly 10 includes a positive electrode sheet, a negative electrode sheet and a separator. The battery cell 100 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 electrode collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode collector, the positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer, and the positive electrode collector not coated with the positive electrode active material layer serves as a positive electrode ear. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode collector, the negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer, and the negative electrode collector not coated with the negative electrode active material layer serves as a negative electrode ear.

[0139] Taking a lithium-ion battery cell as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, lithium metal or lithium alloy, etc. In order to ensure that a large current passes without melting, the number of positive pole ears is multiple and stacked together, and the number of negative pole ears is multiple and stacked together. The material of the isolation film may be polypropylene (PP) or polyethylene (PE), etc. In addition, the electrode assembly 10 in the embodiment of the present application includes but is not limited to a winding structure or a laminated structure.

[0140] For the sake of convenience, the positive electrode sheet and the negative electrode sheet are collectively referred to as the electrode sheet 11, and the positive electrode ear and the negative electrode ear are collectively referred to as the electrode ear 12; the "inner wall surface" can be understood as the wall surface of the component facing the electrode assembly 10, and the "outer wall surface" can be understood as the wall surface of the component facing away from the electrode assembly 10, unless otherwise defined.

[0141] The edge 10 a of the electrode assembly 10 may refer to an intersection line formed by two adjacent surfaces of the electrode assembly 10 , and the intersection line is likely to interfere with the housing 20 .

[0142] Among the two adjacent side walls of the outer shell 20, one side wall is the first side wall 221, and the other side wall is the second side wall 222. A first arc-shaped portion 224 is connected between the first side wall 221 and the second side wall 222. The first arc-shaped portion 224 may refer to a structure for smoothly transitioning the first side wall 221 and the second side wall 222. After the electrode assembly 10 is installed in the outer shell 20, the edge 10a of the electrode assembly 10 is arranged opposite to the first arc-shaped portion 224.

[0143] For example, see Figure 7As shown, the first arc portion 224 is a rounded structure, which can also be called an R angle. The rounded structure closest to the edge 10a of the electrode assembly 10 can be called the first arc portion 224. The boundary line between the first side wall 221 and the first arc portion 224 can refer to the dotted line c in the figure, and the boundary line between the second side wall 222 and the first arc portion 224 can refer to the dotted line d in the figure.

[0144] For example, see Figure 3 As shown, the electrode assembly 10 is a laminated structure, and the electrode assembly 10 includes a plurality of pole pieces 11, and the plurality of pole pieces 11 are stacked along the height direction of the battery cell 100; two end caps 21 are respectively covered at the left and right openings of the shell 22. After the electrode assembly 10 is placed in the shell 22, the two edges of the pole piece 11 located on the lower side that are relatively distributed along the width direction of the battery cell 100 and the two edges of the pole piece 11 located on the upper side that are relatively distributed along the width direction of the battery cell 100 are easy to interfere with the shell 20, and the pole piece 11 located on the lower side is relatively distributed along the width direction of the battery cell 100. The two edges of the pole piece 11 that are relatively distributed along the width direction of the battery cell 100 can be called the edges 10a of the electrode assembly 10, and the two edges of the pole piece 11 located on the upper side that are relatively distributed along the width direction of the battery cell 100 can also be called the edges 10a of the electrode assembly 10, the bottom wall and the top wall of the shell 22 can be called the second side wall 222, the front wall and the rear wall of the shell 22 can be called the first side wall 221, and the four chamfered structures connected between the first side wall 221 and the second side wall 222 can be called the first arc portion 224.

[0145] For example, see Figure 8 As shown, the electrode assembly 10 is a laminated structure, and the electrode assembly 10 includes a plurality of pole pieces 11, and the plurality of pole pieces 11 are stacked along the height direction of the battery cell 100; the end cover 21 is covered on the upper opening of the shell 22, and after the electrode assembly 10 is placed in the shell 22, the edges of the pole pieces 11 located on the lower side that are relatively distributed along the width direction of the battery cell 100 are easily interfered with the shell 22, and the two edges of the pole pieces 11 located on the lower side that are relatively distributed along the width direction of the battery cell 100 are called edges 10a of the electrode assembly 10, the bottom wall of the shell 22 can be called the first side wall 221, the left wall and the right wall of the shell 22 can be called the second side wall 222, and the two chamfered structures connected between the first side wall 221 and the second side wall 222 can be called the first arc portion 224.

[0146] For example, see Fig.15As shown, the electrode assembly 10 may be in a wound flat structure, and the end cover 21 is covered on the upper opening of the shell 22. After the electrode assembly 10 is placed in the shell 22, the winding axis of the electrode assembly 10 (refer to the straight line g) is parallel or nearly parallel to the height direction of the battery cell 100; the top surface of the electrode assembly 10 leads to the pole ear 12, and in the edge line of the bottom surface of the electrode assembly 10, its two ends are arc lines 10b, and the middle part is a long straight line 10c or similar to the long straight line 10c; after the electrode assembly 10 is installed in the shell 20, the long straight line 10c is easy to interfere with the shell 20, and the long straight line 10c can be called the edge 10a of the electrode assembly 10. The long straight line 10c may refer to the edge line of the lower end of the electrode sheet 11 or diaphragm located in the outermost circle of the electrode assembly 10 extending along the length direction of the battery cell 100, the bottom wall of the shell 22 may be called the first side wall 221, the front wall and the rear wall of the shell 22 may be called the second side wall 222, and the two chamfered structures connected between the first side wall 221 and the second side wall 222 may be called the first arc portion 224.

[0147] For example, see Fig.23 As shown, the electrode assembly 10 may be in a wound flat structure, and the end cover 21 is covered on the right opening of the shell 22. After the electrode assembly 10 is placed in the shell 22, the winding axis of the electrode assembly 10 (refer to the straight line g) is parallel or nearly parallel to the height direction of the battery cell 100; the electrode ear 12 is led out from the right side of the top surface of the electrode assembly 10, and in the edge line of the bottom surface of the electrode assembly 10, its two ends are arc lines 10b, and the middle part is a long straight line 10c or similar to the long straight line 10c; in the edge line of the top surface of the electrode assembly 10, its two ends are arc lines 10b, and the middle part is also a long straight line 10c or similar to the long straight line 10c; wherein, after the electrode assembly 10 is loaded into the shell 20, the long straight line 10c on the left side of the top and bottom of the electrode assembly 10 is easy to interfere with the shell 20, and the long straight line 10c on the left side of the top and bottom of the electrode assembly 10 can be called the edge 10a of the electrode assembly 10. The long straight line 10c may refer to the edge lines of the top and bottom of the electrode sheet 11 or the diaphragm located in the outermost circle of the electrode assembly 10 extending along the length direction of the battery cell 100, the left wall of the shell 22 may be called the first side wall 221, the bottom wall and the top wall of the shell 22 may be called the second side wall 222, and the two chamfered structures connected between the first side wall 221 and the second side wall 222 may be called the first arc portion 224.

[0148] The wall surface of the first arc-shaped portion 224 facing the electrode assembly 10 may refer to the inner wall surface of the first arc-shaped portion 224; the cross-sectional shape of the inner wall surface of the first arc-shaped portion 224 may be an arc or close to an arc, and the inner wall surface of the first arc-shaped portion 224 includes two arc surfaces with different radii, wherein the arc surface with a smaller radius is the second arc surface 224b, and the arc surface with a larger radius is the first arc surface 224a; the number of the first arc surfaces 224a may be two, and the length direction of the edge of the electrode assembly (see Figure 4 In the X direction), the two first arc surfaces 224a are respectively connected to the two ends of the second arc surface 224b, that is, the second arc surface 224b is located in the middle position of the first arc portion 224, and the two first arc surfaces 224a are respectively located at the two ends of the first arc portion 224, so that the second arc surface 224b can be arranged opposite to the edge 10a of the electrode assembly 10.

[0149] The radius of the second arc surface 224b is smaller than the radius of the first arc surface 224a, so that the second arc surface 224b can provide an escape space 101 for the edge 10a corresponding to the electrode assembly 10. It can be understood that, referring to Figure 7 As shown, after the electrode assembly 10 is installed in the outer shell 20, the distance between the second arc surface 224b and the edge 10a of the electrode assembly 10 is greater than the distance between the first arc surface 224a and the edge 10a of the electrode assembly 10, so that the second arc surface 224b can provide an avoidance space 101 for the edge 10a of the electrode assembly 10.

[0150] Based on this, in order to improve the volume energy density of the battery cell 100, the embodiment of the present application provides a battery cell 100, the electrode assembly 10 is installed in the shell 20, and a first arc portion 224 is provided between the first side wall 221 and the second side wall 222 of the shell 20, and the first arc portion 224 smoothly transitions to connect the first side wall 221 and the second side wall 222, thereby reducing stress concentration, improving the structural strength of the shell 20, and facilitating the molding of the shell 20; in addition, the first arc portion 224 is arranged opposite to the edge 10a of the electrode assembly 10, and the wall surface of the first arc portion 224 facing the electrode assembly 10 includes a first arc surface 224a and a second arc surface 224b, and along the length direction of the edge 10a of the electrode assembly 10, the two ends of the second arc surface 224b are connected to the first arc surface 224a, so that the second arc surface 224b and the electrode The edges 10a of the assembly 10 are arranged relatively to each other, and the radius of the second arc surface 224b is smaller than the radius of the first arc surface 224a, so that the second arc surface 224b can provide an avoidance space 101 for the edge 10a of the electrode assembly 10, thereby reducing the risk of interference between the edge 10a of the electrode assembly 10 and the first arc portion 224. In this way, the insulating plate can be omitted or the insulating plate can be thinned, so that a larger volume of electrode assembly 10 can be installed in the shell 20, which is beneficial to improving the volume energy density of the battery cell 100; in addition, during the expansion process of the electrode assembly 10, the avoidance space 101 provided by the second arc surface 224b can also reduce the amount of interference between the electrode assembly 10 and the first arc portion 224, reducing the risk of decarbonization and lithium precipitation of the electrode assembly 10 due to interference with the first arc portion 224, which is beneficial to improving the charging and discharging performance of the battery cell 100.

[0151] In some embodiments, the battery cell 100 further includes an electrode terminal 211, which may be disposed on the end cap 21 or on the housing 22. There are two electrode terminals 211, which are electrically connected to the positive electrode tab and the negative electrode tab, respectively, so that the battery cell 100 outputs or inputs electrical energy.

[0152] In some embodiments, the battery cell 100 further includes a pressure relief mechanism 212 , which may be disposed on the end cover 21 or on the housing 22 . The pressure relief mechanism 212 may be an explosion-proof valve, an explosion-proof disk, or the like.

[0153] In some embodiments, the battery cell 100 further includes an insulating member, which may be disposed inside the end cap 21 to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be plastic, rubber, or the like.

[0154] In some embodiments, the battery cell 100 further includes an insulating film 30, which is coated on the outside of the electrode assembly 10 to isolate the housing 20 and the electrode assembly 10 to reduce the risk of short circuit. For example, the insulating film 30 can be polypropylene, polyethylene, polybutylene, etc.

[0155] In other embodiments of the present application, see Figure 4 As shown, the wall surface of the first arc-shaped portion 224 facing the electrode assembly 10 further includes a first connecting surface 224c, which is connected between the second arc surface 224b and the first arc surface 224a, and is an arc surface.

[0156] The first connecting surface 224c may refer to a portion of the inner wall surface of the first arc-shaped portion 224 located between the first arc surface 224a and the second arc surface 224b; the cross-sectional shape of the first connecting surface 224c is an arc, that is, the first connecting surface 224c is an arc surface.

[0157] For example, see Figure 4 As shown, the boundary line between the second arc surface 224b and the first connecting surface 224c can be referred to as the dotted line a in the figure, and the boundary line between the first arc surface 224a and the first connecting surface 224c can be referred to as the dotted line b in the figure.

[0158] By adopting the technical solution of this embodiment, the first arc surface 224a and the second arc surface 224b are connected by the arc surface, and the structure of the first arc portion 224 is regular, which facilitates the molding of the shell 20 and is also beneficial to reducing stress concentration and improving the structural strength of the shell 20.

[0159] In other embodiments of the present application, see Figure 4 As shown, in the direction from the second arc surface 224b to the first arc surface 224a, the radius of the first connecting surface 224c increases.

[0160] The direction of the second arc surface 224b toward the first arc surface 224a can be referred to Figure 4 In the X direction, in the direction from the second arc surface 224b to the first arc surface 224a, the radius of the first connecting surface 224c may increase in steps or gradually and smoothly.

[0161] By adopting the technical solution of this embodiment, the first arc surface 224a and the second arc surface 224b are smoothly connected through the first connecting surface 224c, which can reduce stress concentration, improve the structural strength of the shell 20, and facilitate the molding of the shell 20.

[0162] In other embodiments of the present application, see Figures 8 to 10As shown, the midline of the second arc surface 224b is connected to the midline of the first connecting surface 224c, and the angle between the midline of the second arc surface 224b and the midline of the first connecting surface 224c is α, wherein 90°≤α≤180°.

[0163] The midline of the second arc surface 224b may refer to a line that bisects the second arc surface 224b, and the line is located between two opposite side lines of the first arc surface 224a that are relatively distributed along its arc extension direction; the midline of the first connecting surface 224c may refer to a line that bisects the first connecting surface 224c, and the line may extend from the second arc surface 224b to the first arc surface 224a.

[0164] For example, combined with Fig.10 As shown, the midline of the second arc surface 224b can refer to the straight line e, and the midline of the first connecting surface 224c can refer to the straight line f.

[0165] 90°≤α≤180°. It can be understood that the midline of the second arc surface 224b is perpendicular to, or forms an obtuse angle with, or coincides with the midline of the first connecting surface 224c.

[0166] By adopting the technical solution of this embodiment, the first connecting surface 224 c can be exposed outside the first arc-shaped portion 224 , thereby facilitating the molding of the shell 22 and also facilitating improving the structural strength of the housing 20 .

[0167] In other embodiments of the present application, see Figures 8 to 10 As shown, 120°≤α≤160°.

[0168] 120°≤α≤160°. It can be understood that α≤160° allows the second arc surface 224b to be tilted and extended to the first arc surface 224a, and the first arc surface 224a and the first connecting surface 224c can be smoothly connected, which is beneficial to reducing stress concentration and improving the structural strength of the shell 20; in addition, α≥120°, so that the inclination angle of the second arc surface 224b extending to the first arc surface 224a is not too large, which is also beneficial to reducing stress concentration and improving the structural strength of the shell 20.

[0169] By adopting the technical solution of this embodiment, the first connecting surface 224c can be tilted and smoothly connected to the first arc surface 224a and the second arc surface 224b, which is beneficial to reducing stress concentration and improving the structural strength of the housing 20.

[0170] In some embodiments, the value of α may be 90°, 180°, or any number between 90° and 180°. For example, the value of α may be, but is not limited to, 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 140°, 150°, 160°, 170°, or 180°.

[0171] In other embodiments of the present application, see Figure 7 As shown, the radius of the first arc surface 224a is R 1 , the radius of the second arc surface 224b is R 2 , where 1 / 3≤R 2 / R 1 <1.

[0172] 1 / 3≤R 2 / R 1 <1, it is understandable that R 2 / R 1 <1, so that the radius of the second arc surface 224b is smaller than the radius of the first arc surface 224a, and the second arc surface 224b can provide an escape space 101 for the edge 10a of the electrode assembly 10; R 2 / R 1 ≥1 / 3, so that the radius of the second arc surface 224b is not too small, stress concentration is reduced, the structural strength of the shell 20 is improved, and the molding of the shell 20 is also facilitated.

[0173] By adopting the technical solution of this embodiment, the avoidance of the edge 10a of the electrode assembly 10, the structural strength of the shell 20 and the convenience of forming the shell 20 can be taken into consideration at the same time.

[0174] In other embodiments of the present application, see Figure 7 As shown, 0.5≤R 2 / R 1 ≤0.9.

[0175] By adopting the technical solution of this embodiment, the radius design of the second arc surface 224b is more reasonable, which can better take into account the avoidance of the edge 10a of the electrode assembly 10, the structural strength of the shell 20 and the convenience of forming the shell 20.

[0176] In some embodiments, R 2 / R 1 The value of can be 1 / 3 or any number between 1 / 3 and 1. For example, R 2 / R 1 The value of can be 1 / 3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.99.

[0177] In some embodiments, see Fig.15As shown, 0.5mm≤R 1 ≤2mm, 0.3mm≤R 2 ≤0.8mm, such a design can better take into account the avoidance of the edge 10a of the electrode assembly 10, the structural strength of the shell 20 and the convenience of molding the shell 20.

[0178] In other embodiments of the present application, see Figure 7 As shown, the radius of the second arc surface 224b is R 2 , where 0.3mm≤R 2 ≤5mm.

[0179] 0.3mm≤R 2 ≤5mm, it is understandable that R 2 ≤5mm, the radius of the second arc surface 224b is small, and the second arc surface 224b can provide a larger avoidance space 101 for the edge 10a of the electrode assembly 10; R 2 ≥0.3mm, so that the radius of the second arc surface 224b is not too small, stress concentration is reduced, the structural strength of the shell 20 is improved, and the molding of the shell 20 is also facilitated.

[0180] By adopting the technical solution of this embodiment, the avoidance of the edge 10a of the electrode assembly 10, the structural strength of the shell 20 and the convenience of forming the shell 20 can be taken into consideration at the same time.

[0181] In other embodiments of the present application, see Figure 7 As shown, 0.5mm≤R 2 ≤3mm.

[0182] By adopting the technical solution of this embodiment, the radius of the second arc surface 224b is designed to be more reasonable, which can better take into account the avoidance of the edge 10a of the electrode assembly 10, the structural strength of the shell 20 and the convenience of forming the shell 20.

[0183] In some embodiments, R 2 The value of can be 0.3mm, 5mm or any number between 0.3mm and 5mm. For example, R 2 The value of can be 0.3mm, 0.4mm, 0.5mm, 0.7mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm.

[0184] In other embodiments of the present application, see Figure 4 and Figure 5 As shown, the dimension of the first side wall 221 in the length direction of the edge 10a of the electrode assembly 10 is L 1The distance between the end of the second arc surface 224b and the end of the adjacent first side wall 221 is L 2 , where 0<L 2 / L 1 ≤0.2.

[0185] See also Figure 4 and Figure 5 As shown, the length direction of the edge 10a of the electrode assembly 10 can be referred to Figure 4 In the X direction, the dimension L of the first side wall 221 is 1 The distance L between the end of the second arc surface 224b and the end of the adjacent first side wall 221 may refer to the distance between the two end surfaces of the first side wall 221 that are opposite to each other along the X direction. 2 It may refer to the distance between the edge line of the second arc surface 224 b in the X direction and the end surface of the adjacent first side wall 221 .

[0186] See also Fig.13 and Fig.14 As shown, the length of the edge 10a of the electrode assembly 10 can be referred to Fig. 9 In the Z direction, the dimension L of the first side wall 221 is 1 It may refer to the distance between two side walls of the housing 20 that are oppositely distributed along the Z direction; the distance L between the end of the second arc surface 224b and the end of the adjacent first side wall 221 2 It may refer to the distance between the second arc surface 224 b and the adjacent side wall (third side wall 223 ) in the Z direction.

[0187] See also Fig.19 , Fig. 20 , Fig.25 and Fig.26 As shown, the length of the edge 10a of the electrode assembly 10 can be referred to Fig.19 In the Z direction, the dimension L of the first side wall 221 is 1 It may refer to the distance between two outer wall surfaces of the housing 20 that are oppositely distributed along the Z direction, the distance L between the end of the second arc surface 224b and the end of the adjacent first side wall 221 2 It may refer to the distance between the second arc surface 224 b and the outer wall surface of the adjacent side wall (third side wall 223 ) in the Z direction.

[0188] 0<L 2 / L 1≤0.2, it can be understood that the second arc surface 224b is longer and can better avoid most of the edge 10a of the electrode assembly 10. The length of the edge 10a of the electrode assembly 10 can be greater than the length of the second arc surface 224b, so that the second arc surface 224b can completely avoid the edge 10a of the electrode assembly 10; the length of the second arc surface 224b can also be slightly smaller than the length of the edge 10a of the electrode assembly 10, so that the end of the edge 10a of the electrode assembly 10 cannot be avoided, but when the electrode assembly 10 expands, the expansion amount of the electrode assembly 10 at the end of the edge 10a is small, and its interference amount is small, so the second arc surface 224b does not extend to the end of the edge 10a of the electrode assembly 10 and can also meet the use; in addition, the length of the second arc surface 224b is slightly smaller than the length of the edge 10a of the electrode assembly 10, which is also beneficial to improve the structural strength of the first arc portion 224.

[0189] By adopting the technical solution of this embodiment, the second arc surface 224b can play a better role in avoiding the edge 10a of the electrode assembly 10, and at the same time, the shell 20 also has good structural strength.

[0190] In other embodiments of the present application, see Figure 4 and Figure 5 As shown, 0.05≤L 2 / L 1 ≤0.15.

[0191] By adopting the technical solution of this embodiment, the length design of the second arc surface 224 b is more reasonably designed, which can better take into account the avoidance of the edge 10 a of the electrode assembly 10 and the structural strength of the shell 20 .

[0192] In some embodiments, L 2 / L 1 The value of can be 0.2 or any number between 0 and 0.2. For example, L 2 / L 1 The value of can be but is not limited to 0.01, 0.03, 0.05, 0.07, 0.09, 0.11, 0.13, 0.15, 0.17, 0.2.

[0193] In other embodiments of the present application, the size of the second arc surface 224b in the length direction of the edge 10a of the electrode assembly 10 is L 3 , the length of the edge 10a of the electrode assembly 10 is L 4 , where L 3 ≥L 4 .

[0194] See also Figure 3 and Figure 4 As shown, the length L of the edge 10a of the electrode assembly 10 is 4It may refer to the length of the sideline of the electrode assembly 10 extending along the X direction. The dimension L of the second arc surface 224b in the length direction of the edge 10a of the electrode assembly 10 is 3 It may refer to the distance between two side edges of the second arc surface 224b that are relatively distributed in the X direction.

[0195] See also Figure 8 , Figures 12-14 As shown, the length L of the edge 10a of the electrode assembly 10 is 4 It may refer to the length of the sideline of the electrode assembly 10 extending along the Z direction. The dimension L of the second arc surface 224b in the length direction of the edge 10a of the electrode assembly 10 is 3 It may refer to the distance between two side edges of the second arc surface 224b that are relatively distributed in the Z direction.

[0196] See also Fig.15 , Fig.19 , Fig. 20 , Figures 23-26 As shown, the length L of the edge 10a of the electrode assembly 10 is 4 It may refer to the length of the long straight line 10c of the electrode assembly 10 extending along the Z direction. The dimension L of the second arc surface 224b in the length direction of the edge 10a of the electrode assembly 10 3 It may refer to the distance between two side edges of the second arc surface 224b that are relatively distributed in the Z direction.

[0197] By adopting the technical solution of this embodiment, L 3 ≥L 4 The design makes the length of the second arc surface 224b greater than the length of the edge 10a of the electrode assembly 10, and the first arc portion 224 can completely avoid the edge 10a of the electrode assembly 10, with a good avoidance effect.

[0198] In some embodiments, see Fig.13 and Fig.14 As shown, when the first arc surface 224a is connected to both ends of the second arc surface 224b, L 1 =L 3 +2*L 2 .

[0199] In other embodiments of the present application, see Figure 3As shown, the shell 20 includes a shell 22 and two end covers 21. The two end surfaces of the shell 22 that are relatively distributed along the first direction are provided with openings. The electrode assembly 10 is located in the shell 22, and the two end covers 21 cover the two openings respectively. The two side walls of the shell 22 that are relatively distributed along the second direction are first side walls 221, and the two side walls of the shell 22 that are relatively distributed along the third direction are second side walls 222. A first arc portion 224 is connected between the first side wall 221 and the adjacent second side wall 222, and the first direction, the second direction and the third direction are perpendicular to each other.

[0200] The first direction is perpendicular to the second direction, the second direction is perpendicular to the third direction, the third direction is perpendicular to the first direction, and the first direction can refer to Figures 3 to 7 The X direction in the second direction can be found in Figures 3 to 7 The Y direction in the third direction can be found in Figures 3 to 7 In the Z direction, the shell 22 has openings at two ends that are opposite to each other in the first direction, and the two end covers 21 are respectively covered at the two openings, thereby realizing the packaging of the shell 20; the two side walls of the shell 22 that are opposite to each other in the second direction can both be called first side walls 221, and the two side walls of the shell 22 that are opposite to each other in the third direction are called second side walls 222, wherein the first arc-shaped portions 224 are connected between the two opposite sides of one first side wall 221 and the two second side walls 222, respectively, and the first arc-shaped portions 224 are connected between the two opposite sides of the other first side wall 221 and the two second side walls 222, respectively, thereby enclosing a space for accommodating the electrode assembly 10.

[0201] By adopting the technical solution of this embodiment, the edge 10a of the electrode assembly 10 extending along the first direction is correspondingly provided with a second arc surface 224b for avoidance, and the avoidance effect of the electrode assembly 10 is good; the outer shell 20 adopts the structural form of a shell 22 and two end covers 21, the structure is simple, and the assembly and sealing of the battery cell 100 are simple.

[0202] In other embodiments of the present application, see Figure 3 As shown, the electrode assembly 10 includes a plurality of pole pieces 11, and the plurality of pole pieces 11 are stacked along a third direction.

[0203] The electrode assembly 10 is a laminated structure, and a plurality of electrode sheets 11 in the electrode assembly 10 are stacked along a third direction.

[0204] By adopting the technical solution of this embodiment, multiple pole pieces 11 are stacked along the third direction, so that the electrode assembly 10 has four edges 10a extending along the second direction, and the second arc surfaces 224b of the four first arc-shaped portions 224 connected between the first side wall 221 and the second side wall 222 can be arranged opposite to the four edges 10a, thereby providing an avoidance space 101, reducing the risk of interference between the electrode assembly 10 and the outer shell 20, and is beneficial to improving the volume energy density and charge and discharge performance of the battery cell 100.

[0205] In other embodiments of the present application, see Figure 8 , Fig.15 and Fig.23 As shown, the shell 20 includes a shell 22 and an end cover 21, and the electrode assembly 10 is located in the shell 22; one of the two end surfaces of the shell 22 relatively distributed along the first direction is provided with an opening, and the end cover 21 covers the opening; the side wall of the shell 22 and the end cover 21 relatively arranged is a first side wall 221, the two side walls of the shell 22 relatively distributed along the second direction are second side walls 222, and the two side walls of the shell 22 relatively distributed along the third direction are third side walls 223; a first arc portion 224 is connected between at least one second side wall 222 and the side portion corresponding to the first side wall 221, and the first direction, the second direction and the third direction are perpendicular to each other.

[0206] For the first direction, please refer to Figures 8 to 30 The X direction in the second direction can be found in Figures 8 to 30 The Y direction in the third direction can be found in Figures 8 to 30 In the Z direction, the shell 22 is provided with an opening, which is located on one of the two end surfaces of the shell 22 that are oppositely arranged in the first direction, and the end cover 21 is covered at the opening, so as to realize the packaging of the shell 20; the two side walls of the shell 22 that are oppositely arranged in the second direction can be called second side walls 222, and the two side walls of the shell 22 that are oppositely arranged in the third direction are called third side walls 223, one opposite side portion of the first side wall 221 is respectively connected to the two second side walls 222, and the other opposite side portions of the first side wall 221 are respectively connected to the two third side walls 223, and a space for accommodating the electrode assembly 10 is formed. Among them, a first arc-shaped portion 224 is connected between one second side wall 222 and the first side wall 221, and the other second side wall 222 can directly intersect with the first side wall 221 or be connected to the first side wall 221 through an arc-shaped portion; or, the first arc-shaped portion 224 is connected between the two second side walls 222 and the first side wall 221.

[0207] By adopting the technical solution of this embodiment, the edge 10a of the electrode assembly 10 extending along the third direction is correspondingly provided with a second arc surface 224b for avoidance, and the avoidance effect of the electrode assembly 10 is good; the outer shell 20 adopts the structural form of a shell 22 and an end cover 21, the structure is simple, and the assembly and sealing of the battery cell 100 are simple.

[0208] In some embodiments, see Figure 8 As shown, the third side wall 223 may be a stepped structure to provide installation space for the tab 12 of the electrode assembly 10. Of course, in other embodiments, see Fig.14 As shown, the third side wall 223 may be a flat plate structure.

[0209] In other embodiments of the present application, see Figure 8 , Fig.15 and Fig.23 As shown, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the first direction; or, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the second direction; or, the electrode assembly 10 includes a plurality of pole pieces 11, and the plurality of pole pieces 11 are stacked along the first direction.

[0210] The electrode assembly 10 is a wound structure. It can be understood that the electrode sheet 11 is wound to form the electrode assembly 10. For example, the electrode assembly 10 can be a wound flat structure, wherein the electrode sheet 11 can be wound into a cylinder and then flattened to obtain the wound flat structure electrode assembly 10. The electrode assembly 10 can also be obtained in other ways; of course, the electrode assembly 10 can be a wound cylindrical structure; wherein the winding axis of the electrode assembly 10 can refer to Fig.15 , Fig.17 and Fig.23 The straight line g in the winding flat electrode assembly 10 , the long straight line 10 c of the electrode assembly 10 is likely to interfere with the case 22 .

[0211] In one possible implementation, see Fig.15As shown, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the first direction, so that after the electrode assembly 10 is installed in the shell 22, the long straight line 10c of the electrode assembly 10 facing away from the opening of the shell 22 is easy to interfere with the shell 22, but in this embodiment, the second arc surface 224b of the first arc portion 224 is located on the side of the opening facing away from the shell 22 and is arranged opposite to the long straight line 10c of the electrode assembly 10, thereby avoiding the long straight line 10c, reducing the risk of interference between the electrode assembly 10 and the shell 22, and is conducive to improving the volume energy density of the battery cell 100 and the charge and discharge performance of the battery cell 100. Among them, the number of the first arc portion 224 can be one, thereby avoiding the long straight line 10c located on one side, and the number of the second arc portion 225 can be two, thereby avoiding the long straight lines 10c located on both sides.

[0212] In another possible implementation, see Fig.23 As shown, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the second direction, so that after the electrode assembly 10 is loaded into the shell 22, the long straight line 10c of the electrode assembly 10 facing away from the opening of the shell 22 is easy to interfere with the shell 22, but in this embodiment, the second arc surface 224b of the first arc portion 224 is located on the opening side facing away from the shell 22 and is arranged opposite to the long straight line 10c of the electrode assembly 10, thereby avoiding the long straight line 10c, which is beneficial to improve the volume energy density of the battery cell 100 and the charge and discharge performance of the battery cell 100.

[0213] For example, see Figures 23 to 27As shown, after the electrode assembly 10 is loaded into the shell 22, under the action of its own gravity, the long straight line 10c of the electrode assembly 10 on the lower side is most likely to interfere with the shell 22. Therefore, the first arc portion 224 may be connected only between the second side wall 222 on the lower side and the lower side of the first side wall 221, and the second arc surface 224b of the first arc portion 224 may be used to avoid the long straight line 10c on the lower side; the upper side of the second side wall 222 may directly intersect with the upper side of the first side wall 221, or may be connected through the arc portion to reduce stress concentration; or, the first arc portion 224 may be connected between the second side walls 222 on the upper and lower sides and the upper and lower sides of the first side wall 221, and the second arc surfaces 224b of the two first arc portions 224 may be used to avoid the long straight lines 10c on the upper and lower sides of the electrode assembly 10, so that the avoidance effect is better. Among them, the middle part of the second side wall 222 located on the upper side can be recessed so that space for accommodating the pole ear 12 is formed at both ends of the second side wall 222. At this time, the recessed part of the second side wall 222 is easy to interfere with the long straight line 10c located on the upper side. Therefore, a first arc-shaped portion 224 is connected between the second side wall 222 located on the upper side and the upper side of the first side wall 221. The second arc surface 224b on the first arc-shaped portion 224 can pass through the part where the first arc-shaped portion 224 is connected to the recessed part, or it can only occupy a partial area where the first arc-shaped portion 224 is connected to the recessed part.

[0214] In another possible implementation, see Figure 8 As shown, the electrode assembly 10 includes a plurality of pole pieces 11, and the plurality of pole pieces 11 are stacked along a first direction. The electrode assembly 10 is a laminated structure. After the electrode assembly 10 with the plurality of pole pieces 11 stacked along the first direction is loaded into the housing 22, the edge 10a of the electrode assembly 10 facing away from the opening of the housing 22 and extending along the third direction is easy to interfere with the housing 22. However, in this embodiment, the second arc surface 224b of the first arc portion 224 is located on the side facing away from the opening of the housing 22 and can be arranged opposite to the edge 10a, thereby avoiding the edge 10a, which is beneficial to improving the volume energy density of the battery cell 100 and the charge and discharge performance of the battery cell 100.

[0215] By adopting the technical solution of this embodiment, the housing 20 can meet the avoidance requirements of electrode assemblies 10 in various structural forms and has a wide range of applications.

[0216] In other embodiments of the present application, see Fig.15 , Fig.19 and Fig. 20 As shown, the electrode assembly 10 is a winding structure, the winding axis of the electrode assembly 10 is parallel to the first direction, and the size of the electrode assembly 10 in the second direction is W 1 The distance between the second arc surface 224b and the adjacent third side wall 223 is W 2, where 1 / 15≤W 2 / W 1 ≤0.5.

[0217] The dimension W of the electrode assembly 10 in the second direction 1 It may refer to the distance between two sides of the electrode assembly 10 that are relatively distributed in the second direction; for example, the shape of the shell 22 may be adapted to the shape of the electrode assembly 10 to better accommodate the electrode assembly 10, see Fig.15 As shown, the shell 22 is a rectangular parallelepiped, and the electrode assembly 10 has a height direction, a width direction, and a length direction. The width direction of the electrode assembly 10 is parallel to the width direction of the shell 22, the height direction of the electrode assembly 10 is parallel to the height direction of the shell 22, and the length direction of the shell 22 is parallel to the length direction of the shell 22. The dimension W of the electrode assembly 10 in the second direction is 1 It may refer to the width of the electrode assembly 10. Of course, in other embodiments, the dimension W of the electrode assembly 10 in the second direction may be 1 It may refer to the height or length of the electrode assembly 10 , which may be specifically determined according to the placement and shape of the electrode assembly 10 .

[0218] The distance W between the second arc surface 224b and the adjacent third side wall 223 is 2 It may refer to the distance between the inner wall surface of the third side wall 223 and the second arc surface 224 b.

[0219] For example, see Fig.15 , Fig.19 and Fig. 20 As shown, when the arc line 10b is a semicircular arc or similar to a semicircular arc, the width W of the electrode assembly 10 is 1 equal to the diameter of the arc line 10b; in the length direction of the electrode assembly 10, the distance between the vertex of the arc line 10b and the long straight line 10c is equal to or greater than half the width of the electrode assembly 10.

[0220] 1 / 15≤W 2 / W 1 ≤0.5, it is understandable that W 2 / W 1 ≤0.5, so that the length of the second arc surface 224b can be greater than or equal to the length of the long straight side of the electrode assembly 10, that is, the length of the second arc surface 224b is greater than or equal to the length of the edge 10a of the electrode assembly 10, so that the second arc surface 224b can avoid the end point of the edge 10a of the electrode assembly 10, that is, the second arc surface 224b can avoid the entire edge 10a of the electrode assembly 10; W 2 / W 1≥1 / 15, so that there is a certain distance between the second arc surface 224b and the third side wall 223, and the second arc surface 224b is not too long, which is beneficial to improve the structural strength of the first arc portion 224 and the shell 22.

[0221] For example, see Fig. 20 As shown, W 2 / W 1 ≥1 / 15, so that the second arc surface 224b does not extend to the arc segment 2242, and the shell 22 has better structural strength.

[0222] By adopting the technical solution of this embodiment, the length of the second arc surface 224 b is reasonably designed, which can take into account both the structural strength of the shell 22 and the avoidance of the edge 10 a of the electrode assembly 10 .

[0223] In other embodiments of the present application, see Fig.15 , Fig.19 and Fig. 20 As shown, 0.1≤W 2 / W 1 ≤0.4.

[0224] By adopting the technical solution of this embodiment, 0.1≤W 2 / W 1 The design of ≤0.4 makes the length design of the second arc surface 224 b more reasonable, which can better take into account the structural strength of the shell 22 and the avoidance of the edge 10 a of the electrode assembly 10 .

[0225] In some embodiments, W 2 / W 1 The value of can be 1 / 15, 0.5 or any value between 1 / 15 and 0.5. For example, W 2 / W 1 The value of can be but is not limited to 1 / 15, 0.07, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5.

[0226] In other embodiments of the present application, see Fig.15 , Fig.19 and Fig. 20 As shown, the electrode assembly 10 is a winding structure, the winding axis of the electrode assembly 10 is parallel to the first direction, and the distance between the second arc surface 224b and the adjacent third side wall 223 is W 2 , where 3mm≤W 2 ≤8mm.

[0227] 3mm≤W 2 ≤8mm, it is understandable that W 2≥3mm, so that there is a certain distance between the second arc surface 224b and the third side wall 223, and the second arc surface 224b is not too long, which is beneficial to improve the structural strength of the shell 22; W 2 ≤8mm, so that the second arc surface 224b can avoid most of the edge 10a of the electrode assembly 10, or even the entire edge 10a.

[0228] For example, see Fig.19 As shown, in some cases, the radius R of the inner wall surface of the arc-shaped connecting portion 2222 is 3 Less than or equal to 3mm, W 2 The design of ≥3 mm prevents the second arc surface 224 b from extending to the arc segment 2242 , and the housing 22 has better structural strength.

[0229] By adopting the technical solution of this embodiment, the length of the second arc surface 224 b is reasonably designed, which can take into account both the structural strength of the shell 22 and the avoidance of the edge 10 a of the electrode assembly 10 .

[0230] In other embodiments of the present application, see Fig.15 , Fig.19 and Fig. 20 As shown, 4mm≤W 2 ≤6mm.

[0231] By adopting the technical solution of this embodiment, 4mm≤W 2 The design of ≤6 mm makes the length design of the second arc surface 224 b more reasonable, which can better take into account the structural strength of the shell 22 and the avoidance of the edge 10 a of the electrode assembly 10 .

[0232] In some embodiments, W 2 The value of can be 3mm, 8mm or any value between 3mm and 8mm. For example, W 2 The value can be but is not limited to 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, and 8mm.

[0233] In other embodiments of the present application, see Figures 8 to 11As shown, the second side wall 222 includes a straight portion 2221 and two arc-shaped connecting portions 2222, and the two arc-shaped connecting portions 2222 are respectively connected between the opposite sides of the straight portion 2221 and the two third side walls 223; the first arc-shaped portion 224 includes a straight segment 2241 and two arc-shaped segments 2242, the straight segment 2241 is connected between the straight portion 2221 and the first side wall 221, and the two arc-shaped segments 2242 are respectively connected between the two arc-shaped connecting portions 2222 and the first side wall 221; at least a portion of the straight segment 2241 facing the wall of the electrode assembly 10 forms a second arc surface 224b, and at least a portion of the first arc surface 224a is arranged on the arc segment 2242 facing the wall of the electrode assembly 10.

[0234] From the opening of the housing 22, the portion of the second side wall 222 extending in a straight line or close to a straight line may be a straight line portion 2221, and the arc-shaped connecting portion 2222 may refer to a structure for smoothly transitioning between the straight line portion 2221 and the third side wall 223; for example, see Fig.10 As shown, the arc-shaped connecting portion 2222 may refer to a rounded structure between the straight portion 2221 and the third side wall 223. The arc-shaped connecting portion 2222 may also be referred to as an R angle.

[0235] Seen from the opening of the shell 22, the portion of the first arcuate portion 224 that extends in a straight line or nearly in a straight line is a straight line segment 2241, and the straight line segment 2241 is connected between the straight line portion 2221 and the first side wall 221. The arcuate segment 2242 may refer to the portion of the first arcuate portion 224 that extends in an arc shape, and the arcuate segment 2242 is connected between the first side wall 221 and the arcuate connecting portion 2222. The shape of the arcuate segment 2242 is adapted to the shape of the arcuate connecting portion 2222 to facilitate the molding of the shell 22. For example, refer to Fig.10 As shown, the arc segment 2242 may refer to a rounded structure between the first side wall 221 and the arc connecting segment. The arc segment 2242 may also be called a corner.

[0236] At least part of the wall of the straight segment 2241 facing the electrode assembly 10 forms the second arc surface 224b, and at least part of the first arc surface 224a is provided on the wall of the arc segment 2242 facing the electrode assembly 10. It can be understood that a part of the inner wall of the straight segment 2241 forms the second arc surface 224b, and another part of the inner wall forms the first connecting surface 224c or the first connecting surface 224c plus a part of the first arc surface 224a; or, the entire inner wall of the straight segment 2241 forms the second arc surface 224b, that is, the inner wall of the straight segment 2241 is the second arc surface 224b, and the first arc surface 224a forms the inner wall of the arc segment 2242, or, the first connecting surface 224c and the second arc surface 224b together form the inner wall of the arc segment 2242. Of course, there are other ways.

[0237] By adopting the technical solution of this embodiment, the straight portion 2221 and the third side wall 223 are smoothly connected through the arc-shaped connecting portion 2222, and the arc-shaped connecting portion 2222 and the first side wall 221 are smoothly connected through the arc segment 2242, which is beneficial to improving the structural reliability of the shell 20; in addition, the length of the second arc surface 224b can be flexibly set to meet different needs.

[0238] In other embodiments of the present application, see Fig.15 , 19 As shown in Figures 22 to 22, the electrode assembly 10 is a winding structure, the winding axis of the electrode assembly 10 is parallel to the first direction, and the second arc portion 225 is connected between the two opposite sides of the first side wall 221 and the two third side walls 223 respectively; the wall surface of the second arc portion 225 facing the electrode assembly 10 includes a third arc surface 225a for being arranged opposite to the vertex of the end of the electrode assembly 10, and the radius of the third arc surface 225a is smaller than the radius of the first arc surface 224a.

[0239] The second arc portion 225 may refer to a structure for smoothly transitioning and connecting the first side wall 221 and the third side wall 223. For example, see Fig.21 As shown, the second arc portion 225 is a rounded structure, and the second arc portion 225 can also be called an R angle. Fig.15 As shown, the vertex of the end of the electrode assembly 10 may refer to the vertex of the arc line 10b of the electrode assembly 10, and the second arc portion 225 is arranged opposite to the vertex of the arc line 10b of the electrode assembly 10, and the vertex of the arc line 10b is also easy to interfere with the second arc portion 225, and the inner wall surface of the second arc portion 225 includes a third arc surface 225a, and the radius of the third arc surface 225a is smaller than the radius of the first arc surface 224a, so that the third arc surface 225a can avoid the vertex of the arc line 10b.

[0240] By adopting the technical solution of this embodiment, the third arc surface 225a of the second arc portion 225 can avoid the apex of the end of the electrode assembly 10. In this way, during the expansion process of the electrode assembly 10, the third arc surface 225a can also provide an avoidance space 101 for the apex of the end of the electrode assembly 10, and can also reduce the interference between the electrode assembly 10 and the second arc portion 225, thereby reducing the risk of decarbonization and lithium deposition of the electrode assembly 10 due to interference with the second arc portion 225, which is beneficial to improving the charging and discharging performance of the battery cell 100.

[0241] In other embodiments of the present application, see Fig.15 , 19 As shown in FIG. 22 , the size of the electrode assembly 10 in the second direction is W 1 The distance between the third arc surface 225a and the straight portion 2221 is W3 , where 1 / 15≤W 3 / W 1 ≤0.5.

[0242] The distance W between the third arc surface 225a and the adjacent straight line portion 2221 is 3 It may refer to the distance between the inner wall surface of the straight portion 2221 and the third arc surface 225 a.

[0243] For example, see Fig.15 , Fig.19 and Fig. 20 As shown, over the width of the electrode assembly 10 , the distance between the vertex of the arc line 10 b and the straight line portion 2221 is equal to or greater than half of the width of the electrode assembly 10 .

[0244] 1 / 15≤W 3 / W 1 ≤0.5, it is understandable that W 3 / W 1 ≤0.5, so that the spacing between the third arc surface 225a and the straight portion 2221 is less than or equal to half the width of the electrode assembly 10, the third arc surface 225a can avoid the vertex of the arc line 10b, and the third arc surface 225a can better avoid the vertex of the end of the electrode assembly 10. In addition, when a plurality of electrode assemblies 10 are arranged in a stacked manner along the width direction of the electrode assembly 10 in the shell 22, the third arc surface 225a can also avoid the vertex of the arc line 10b of all the electrode assemblies 10, and the avoidance effect is better; W 3 / W 1 ≥1 / 15, so that there is a certain distance between the third arc surface 225a and the straight portion 2221, and the third arc surface 225a is not too long, which is beneficial to improving the structural strength of the second arc portion 225 and the shell 22.

[0245] For example, see Fig. 20 As shown, W 3 / W 1 ≥1 / 15, so that the third arc surface 225a does not extend to the arc segment 2242, and the shell 22 has better structural strength.

[0246] By adopting the technical solution of this embodiment, the length of the third arc surface 225 a is reasonably designed, which can take into account both the structural strength of the shell 22 and the avoidance of the electrode assembly 10.

[0247] In other embodiments of the present application, see Fig.15 , Fig.19 and Fig. 20 As shown, 0.1≤W 3 / W 1 ≤0.4.

[0248] By adopting the technical solution of this embodiment, 0.1≤W 3 / W 1 The design of ≤0.4 makes the length design of the third arc surface 225 a more reasonable, which can better take into account the structural strength of the shell 22 and the avoidance of the electrode assembly 10.

[0249] In some embodiments, W 3 / W 1 The value of can be 1 / 15, 0.5 or any value between 1 / 15 and 0.5. For example, W 3 / W 1 The value of can be but is not limited to 1 / 15, 0.07, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5.

[0250] In other embodiments of the present application, see Fig.15 , Fig.19 and Fig. 20 As shown, the distance between the third arc surface 225a and the adjacent straight line portion 2221 is W 3 , where 3mm≤W 3 ≤8mm.

[0251] 3mm≤W 3 ≤8mm, it is understandable that W 3 ≥3mm, so that there is a certain distance between the third arc surface 225a and the straight portion 2221, and the third arc surface 225a is not too long, which is beneficial to improve the structural strength of the shell 22; W 3 ≤8mm, so that the third arc surface 225a can avoid the vertex of the arc line 10b of the electrode assembly 10, and the third arc surface 225a can better avoid the end of the electrode assembly 10 in the length direction.

[0252] For example, see Fig. 20 As shown, in some cases, the radius R of the inner wall surface of the arc-shaped connecting portion 2222 is 3 Less than or equal to 3mm; W 3 The design of ≥3 mm prevents the third arc surface 225 a from extending to the arc segment 2242 , and the housing 22 has better structural strength.

[0253] By adopting the technical solution of this embodiment, the length of the third arc surface 225 a is reasonably designed, which can take into account both the structural strength of the shell 22 and the avoidance of the electrode assembly 10.

[0254] In other embodiments of the present application, see Fig.15 , Fig.19 and Fig. 20As shown, 4mm≤W 3 ≤6mm.

[0255] By adopting the technical solution of this embodiment, 4mm≤W 3 The design of ≤6 mm makes the length design of the third arc surface 225 a more reasonable, which can better take into account the structural strength of the shell 22 and the avoidance of the electrode assembly 10.

[0256] In some embodiments, W 3 The value of can be 3mm, 8mm or any value between 3mm and 8mm. For example, W 3 The value can be but is not limited to 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, and 8mm.

[0257] In other embodiments of the present application, see Fig.23 and Fig. 27 As shown, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the second direction; when the battery cell 100 is in use (see Fig.23 In the orientation shown in the figure, the two second side walls 222 are arranged up and down, and the first arc-shaped portion 224 is connected between the opposite two side portions of the first side wall 221 and the two second side walls 222; the radius of the second arc surface 224b of the first arc-shaped portion 224 located on the upper side is smaller than the radius of the first arc surface 224a of the first arc-shaped portion 224 located on the lower side.

[0258] By adopting the technical solution of this embodiment, a first arc portion 224 is connected between the first side wall 221 and the two second side walls 222 arranged upper and lower. The two first arc portions 224 can be respectively arranged opposite to the long straight lines 10c on the upper and lower sides of the electrode assembly 10, and the radius of the second arc surface 224b of the first arc portion 224 located on the upper side is smaller than the radius of the first arc surface 224a of the first arc portion 224 located on the lower side, so that the second arc surface 224b located on the upper side can better avoid the long straight line 10c located on the upper side, and the avoidance effect of the electrode assembly 10 is better.

[0259] In other embodiments of the present application, see Figures 28-30 As shown, the outer wall surface of the first arc-shaped portion 224 includes a fourth arc surface 224d and a fifth arc surface 224e connected to each other, the fourth arc surface 224d is arranged opposite to the first arc surface 224a, the fifth arc surface 224e is arranged opposite to the second arc surface 224b, and the radius of the fifth arc surface 224e is smaller than the radius of the fourth arc surface 224d; or, the outer wall surface of the first arc-shaped portion 224 includes a plane 224g, the plane 224g intersects with the outer wall surface of the first side wall 221, and the plane 224g intersects with the outer wall surface of the second side wall 222.

[0260] The outer wall surface of the first arc-shaped portion 224 may refer to the wall surface of the first arc-shaped portion 224 facing away from the electrode assembly 10; the cross-sectional shape of the outer wall surface of the first arc-shaped portion 224 may be an arc, and the outer wall surface of the first arc-shaped portion 224 includes two arc surfaces with different radii, wherein the arc surface with a smaller radius is the fifth arc surface 224e, and the arc surface with a larger radius is the fourth arc surface 224d; the fourth arc surface 224d and the fifth arc surface 224e are arranged along the length direction of the first arc-shaped portion 224 (see Fig.29 The fourth arc surface 224d is arranged opposite to the first arc surface 224a, and the fifth arc surface 224e is arranged opposite to the second arc surface 224b.

[0261] The outer wall surface of the first arc-shaped portion 224 is a plane 224g, and the plane 224g is inclined relative to the outer wall surface of the first side wall 221 and the outer wall surface of the second side wall 222, thereby forming a chamfered angle structure.

[0262] In one possible implementation, see Fig.28 and Fig.29 As shown, the outer wall surface of the first arc-shaped portion 224 includes a fourth arc surface 224d and a fifth arc surface 224e connected to each other. The fourth arc surface 224d is arranged opposite to the first arc surface 224a, and the fifth arc surface 224e is arranged opposite to the second arc surface 224b. The radius of the fifth arc surface 224e is smaller than the radius of the fourth arc surface 224d, so that the shapes of the inner and outer wall surfaces of the first arc-shaped portion 224 are adapted to each other, so that the material is evenly distributed during molding, reducing stress concentration, which is beneficial to improving the structural strength of the shell 22 and also facilitates the molding of the shell 22.

[0263] In another possible implementation, see Fig.30 As shown, the outer wall surface of the first arc-shaped portion 224 includes a plane 224g, which intersects with the outer wall surface of the first side wall 221, and the plane 224g intersects with the outer wall surface of the second side wall 222. An oblique angle structure can be formed at the outer side of the first arc-shaped portion 224, which is beneficial to reduce stress concentration, improve the structural strength of the shell 22, and facilitate the molding of the shell 22.

[0264] By adopting the technical solution of this embodiment, the structural strength of the shell 22 is improved, and the molding of the shell 22 is also facilitated. In addition, the outer wall surface of the first arc-shaped portion 224 can adopt a variety of structures for flexible selection.

[0265] In some embodiments, see Fig.28 and Fig.29As shown, the outer wall surface of the first arc-shaped portion 224 also includes a second connecting surface 224f, which is arranged opposite to the first connecting surface 224c and has a matching shape, so that the shapes of the inner and outer walls of the first arc-shaped portion 224 are matched, so that the material is evenly distributed during molding, which is beneficial to improving the structural strength of the shell 20.

[0266] The battery cell 100 of the present application is described below in conjunction with some embodiments.

[0267] Embodiment 1

[0268] In this embodiment, see Figures 3 to 7 As shown, the battery cell 100 includes an electrode assembly 10 and a shell 20, the electrode assembly 10 is located in the shell 20, and the shell 20 includes a first side wall 221 and a second side wall 222; a first arc portion 224 is connected between the first side wall 221 and the second side wall 222, the inner wall surface of the first arc portion 224 includes a first arc surface 224a and a second arc surface 224b used to be arranged opposite to the edge 10a of the electrode assembly 10, and the first arc surface 224a is connected to the end of the second arc surface 224b; the radius of the second arc surface 224b is smaller than the radius of the first arc surface 224a, so that the second arc surface 224b can provide avoidance space for the corresponding edge 10a of the electrode assembly 10.

[0269] In this embodiment, the inner wall surface of the first arc-shaped portion 224 also includes a first connecting surface 224c, which is connected between the second arc surface 224b and the first arc surface 224a, and the first connecting surface 224c is an arc surface; in the direction from the second arc surface 224b to the first arc surface 224a, the radius of the first connecting surface 224c increases.

[0270] In this embodiment, the shell 20 includes a shell 22 and two end covers 21. The two end surfaces of the shell 22 relatively distributed along the first direction are provided with openings. The electrode assembly 10 is located in the shell 22, and the two end covers 21 cover the two openings respectively. The two side walls of the shell 22 relatively distributed along the second direction are first side walls 221, and the two side walls of the shell 22 relatively distributed along the third direction are second side walls 222. A first arc portion 224 is connected between the first side wall 221 and the adjacent second side wall 222, and the first direction, the second direction and the third direction are perpendicular to each other.

[0271] In this embodiment, the electrode assembly 10 includes a plurality of pole pieces 11 , and the plurality of pole pieces 11 are stacked along a third direction.

[0272] Embodiment 2

[0273] The difference between this embodiment and the first embodiment is that: Figures 8 to 14As shown, the shell 20 includes a shell 22 and an end cover 21, and the electrode assembly 10 is located in the shell 22; one of the two end surfaces of the shell 22 relatively distributed along the first direction is provided with an opening, and the end cover 21 covers the opening; the side wall of the shell 22 and the end cover 21 relatively arranged is a first side wall 221, the two side walls of the shell 22 relatively distributed along the second direction are second side walls 222, and the two side walls of the shell 22 relatively distributed along the third direction are third side walls 223; a first arc portion 224 is connected between at least one second side wall 222 and the side portion corresponding to the first side wall 221, and the first direction, the second direction and the third direction are perpendicular to each other.

[0274] In this embodiment, the electrode assembly 10 includes a plurality of pole pieces 11 , and the plurality of pole pieces 11 are stacked along a first direction.

[0275] In this embodiment, the inner wall surface of the first arc-shaped portion 224 also includes a first connecting surface 224c, which is connected between the second arc surface 224b and the first arc surface 224a, and the center line of the second arc surface 224b is connected to the center line of the first connecting surface 224c, and the angle between the center line of the second arc surface 224b and the center line of the first connecting surface 224c is α, wherein 90°≤α≤180°.

[0276] In this embodiment, the dimension of the second arc surface 224b in the length direction of the edge 10a of the electrode assembly 10 is L 3 , the length of the edge 10a of the electrode assembly 10 is L 4 , where L 3 ≥L 4 .

[0277] Embodiment 3

[0278] The difference between this embodiment and the second embodiment is that: Figures 15 to 22 As shown, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the first direction.

[0279] In this embodiment, the second side wall 222 includes a straight portion 2221 and two arc-shaped connecting portions 2222, and the two arc-shaped connecting portions 2222 are respectively connected between the opposite sides of the straight portion 2221 and the two third side walls 223; the first arc-shaped portion 224 includes a straight segment 2241 and two arc-shaped segments 2242, the straight segment 2241 is connected between the straight portion 2221 and the first side wall 221, and the two arc-shaped segments 2242 are respectively connected between the two arc-shaped connecting portions 2222 and the first side wall 221; at least a portion of the inner wall surface of the straight segment 2241 forms a second arc surface 224b, and at least a portion of the first arc surface 224a is arranged on the inner wall surface of the arc segment 2242.

[0280] In this embodiment, a second arc portion 225 is connected between the two opposite sides of the first side wall 221 and the two third side walls 223 respectively; the inner wall surface of the second arc portion 225 includes a third arc surface 225a which is arranged opposite to the vertex of the end of the electrode assembly 10, and the radius of the third arc surface 225a is smaller than the radius of the first arc surface 224a.

[0281] Embodiment 4

[0282] The difference between this embodiment and the third embodiment is that: Figures 23 to 29 As shown, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the second direction; when the battery cell 100 is in use, the two second side walls 222 are arranged up and down, and the first arc portion 224 is connected between the opposite side portions of the first side wall 221 and the two second side walls 222; the radius of the second arc surface 224b of the first arc portion 224 located on the upper side is smaller than the radius of the first arc surface 224a of the first arc portion 224 located on the lower side.

[0283] In this embodiment, the outer wall surface of the first arc-shaped portion 224 includes a fourth arc surface 224d and a fifth arc surface 224e connected to each other, the fourth arc surface 224d is arranged opposite to the first arc surface 224a, the fifth arc surface 224e is arranged opposite to the second arc surface 224b, and the radius of the fifth arc surface 224e is smaller than the radius of the fourth arc surface 224d;

[0284] Embodiment 5

[0285] The difference between this embodiment and the third embodiment is that: Fig.30 As shown, the outer wall surface of the first arc-shaped portion 224 includes a plane 224 g , the plane 224 g intersects with the outer wall surface of the first side wall 221 , and the plane 224 g intersects with the outer wall surface of the second side wall 222 .

[0286] In some other embodiments of the present application, a battery 1100 is provided, comprising the battery cell 100 as described in the above embodiment.

[0287] The battery 1100 of the embodiment of the present application adopts the above-mentioned battery cell 100. The battery 1100 has a large volume energy density and good reliability in use. The battery 1100 has a long battery life and good reliability in use.

[0288] In some other embodiments of the present application, an electrical device is provided, comprising the battery 1100 as described in the above embodiment.

[0289] The electric device of the embodiment of the present application adopts the above-mentioned battery 1100. The battery 1100 has a large volume energy density and good reliability. The electric device has a long battery life and better performance.

[0290] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0291] 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: Electrode assembly; a housing, wherein the electrode assembly is located in the housing, and the housing comprises a first side wall and a second side wall; A first arc portion is connected between the first side wall and the second side wall, and the first arc portion is arranged opposite to the edge of the electrode assembly. The wall surface of the first arc portion facing the electrode assembly includes a first arc surface and a second arc surface. Along the length direction of the edge of the electrode assembly, both ends of the second arc surface are connected to the first arc surface; the radius of the second arc surface is smaller than the radius of the first arc surface.

2. The battery cell according to claim 1, characterized in that: The first arc-shaped portion further includes a first connecting surface facing the electrode assembly. The first connecting surface is connected between the second arc surface and the first arc surface. The first connecting surface is an arc surface.

3. The battery cell according to claim 2, characterized in that: In the direction from the second arc surface to the first arc surface, the radius of the first connecting surface increases.

4. The battery cell according to claim 2 or 3, characterized in that: The midline of the second arc surface is connected to the midline of the first connecting surface, and the angle between the midline of the second arc surface and the midline of the first connecting surface is α, wherein 90°≤α≤180°.

5. The battery cell according to claim 4, characterized in that: 120°≤α≤160°。 6. The battery cell according to any one of claims 1 to 5, characterized in that: The radius of the first arc surface is R1, and the radius of the second arc surface is R2, wherein 1 / 3≤R2 / R1<1.

7. The battery cell according to claim 6, characterized in that: 0.5≤R2 / R1≤0.

9.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The radius of the second arc surface is R2, wherein 0.3 mm ≤ R2 ≤ 5 mm.

9. The battery cell according to claim 8, characterized in that: 0.5mm≤R2≤3mm.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The dimension of the first side wall in the length direction of the edge of the electrode assembly is L1, and the distance between the end of the second arc surface and the adjacent end of the first side wall is L2, wherein 0<L2 / L1≤0.

2.

11. The battery cell according to claim 10, characterized in that: 0.05≤L2 / L1≤0.

15.

12. The battery cell according to any one of claims 1 to 11, characterized in that: The dimension of the second arc surface in the length direction of the edge of the electrode assembly is L3, and the length of the edge of the electrode assembly is L4, wherein L3≥L4.

13. The battery cell according to any one of claims 1 to 12, characterized in that: The shell includes a shell and two end covers, and openings are provided on two end surfaces of the shell that are relatively distributed along a first direction, the electrode assembly is located in the shell, and the two end covers cover the two openings respectively; the two side walls of the shell that are relatively distributed along a second direction are the first side walls, and the two side walls of the shell that are relatively distributed along a third direction are the second side walls, the first arc portion is connected between the first side wall and the adjacent second side wall, and the first direction, the second direction and the third direction are perpendicular to each other.

14. The battery cell according to claim 13, characterized in that: The electrode assembly includes a plurality of pole pieces, and the plurality of pole pieces are stacked along the third direction.

15. The battery cell according to any one of claims 1 to 12, characterized in that: The housing comprises a shell and an end cover, the electrode assembly is located in the shell; one of the two end surfaces of the shell that are opposite to each other along a first direction is provided with an opening, and the end cover covers the opening; The side wall of the shell body that is opposite to the end cover is the first side wall, the two side walls of the shell body that are opposite to each other along the second direction are the second side walls, and the two side walls of the shell body that are opposite to each other along the third direction are the third side walls; the first arc-shaped portion is connected between at least one of the second side walls and the side portion corresponding to the first side wall, and the first direction, the second direction and the third direction are perpendicular to each other.

16. The battery cell according to claim 15, characterized in that: The electrode assembly is a winding structure, and the winding axis of the electrode assembly is parallel to the first direction; or, the electrode assembly is a winding structure, and the winding axis of the electrode assembly is parallel to the second direction; or, the electrode assembly includes a plurality of pole pieces, and the plurality of pole pieces are stacked along the first direction.

17. The battery cell according to claim 15, characterized in that: The electrode assembly is a winding structure, the winding axis of the electrode assembly is parallel to the first direction, the size of the electrode assembly in the second direction is W1, and the spacing between the second arc surface and the adjacent third side wall is W2, wherein 1 / 15≤W2 / W1≤0.

5.

18. The battery cell according to claim 17, characterized in that: 0.1≤W2 / W1≤0.

4.

19. The battery cell according to any one of claims 15 to 18, characterized in that: The electrode assembly is a winding structure, the winding axis of the electrode assembly is parallel to the first direction, and the spacing between the second arc surface and the adjacent third side wall is W2, wherein 3mm≤W2≤8mm.

20. The battery cell according to claim 19, characterized in that: 4mm≤W2≤6mm.

21. The battery cell according to any one of claims 15 to 20, characterized in that: The second side wall includes a straight portion and two arc-shaped connecting portions, and the two arc-shaped connecting portions are respectively connected between opposite sides of the straight portion and the two third side walls; The first arc portion includes a straight line segment and two arc segments, the straight line segment is connected between the straight line portion and the first side wall, and the two arc segments are respectively connected between the two arc-shaped connecting portions and the first side wall; at least part of the straight line segment facing the wall surface of the electrode assembly forms the second arc surface, and at least part of the first arc surface is arranged on the wall surface of the arc segment facing the electrode assembly.

22. The battery cell according to claim 21, characterized in that: The electrode assembly is a winding structure, the winding axis of the electrode assembly is parallel to the first direction, and second arc portions are connected between two opposite sides of the first side wall and two third side walls respectively; The wall surface of the second arc-shaped portion facing the electrode assembly includes a third arc surface arranged opposite to the vertex of the end of the electrode assembly, and the radius of the third arc surface is smaller than the radius of the first arc surface.

23. The battery cell according to claim 22, characterized in that: The dimension of the electrode assembly in the second direction is W1, and the distance between the third arc surface and the straight portion is W3, wherein 1 / 15≤W3 / W1≤0.

5.

24. The battery cell according to claim 23, characterized in that: 0.1≤W3 / W1≤0.

4.

25. The battery cell according to any one of claims 22 to 24, characterized in that: The distance between the third arc surface and the straight portion is W3, wherein 3mm≤W3≤8mm.

26. The battery cell according to claim 25, characterized in that: 4mm≤W3≤6mm.

27. The battery cell according to any one of claims 15 to 26, characterized in that: The electrode assembly is a winding structure, and the winding axis of the electrode assembly is parallel to the second direction; when the battery cell is in use, the two second side walls are arranged up and down, and the first arc portion is connected between the opposite two sides of the first side wall and the two second side walls; the radius of the second arc surface of the first arc portion located on the upper side is smaller than the radius of the first arc surface of the first arc portion located on the lower side.

28. The battery cell according to any one of claims 1 to 27, characterized in that: The outer wall surface of the first arc-shaped portion includes a fourth arc surface and a fifth arc surface connected to each other, the fourth arc surface is arranged opposite to the first arc surface, the fifth arc surface is arranged opposite to the second arc surface, and the radius of the fifth arc surface is smaller than the radius of the fourth arc surface; Alternatively, the outer wall surface of the first arc-shaped portion includes a plane, the plane intersects with the outer wall surface of the first side wall, and the plane intersects with the outer wall surface of the second side wall.

29. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 28.

30. An electrical device, characterized in that: Comprising the battery of claim 29.

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