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, and at least part of the section of the first arc-shaped part is provided with a first avoiding groove used for avoiding the corresponding edge of the electrode assembly; the first avoiding groove can avoid the edge of the electrode assembly, and the interference risk between the edge of the electrode assembly and the first arc-shaped part is reduced, so that an insulating plate can be omitted or thinned, and the volume energy density of the single battery can be improved; besides, in the expansion process of the electrode assembly, the avoiding space provided by the first avoiding groove can also reduce the interference amount between the electrode assembly and the first arc-shaped part, reduce the risks of decarburization, lithium precipitation and the like caused by interference between the electrode assembly and the first arc-shaped part, and facilitate the improvement of the charge-discharge performance of the battery monomer.

Description

Technical Field

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

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

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

[0004] The above statements are only used to provide background technical information related to this application, and do not necessarily constitute prior art. Summary of the Utility Model

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

[0006] The technical solution adopted in the embodiments of this application is:

[0007] In a first aspect, a battery cell is provided. The battery cell includes an electrode assembly and a housing. The electrode assembly is located inside the housing. The housing includes a first sidewall and a second sidewall; a first arc portion is connected between the first sidewall and the second sidewall. The first arc portion is disposed opposite to the edge of the electrode assembly, and at least a part of the first arc portion is provided with a first avoidance groove for avoiding the corresponding edge of the electrode assembly.

[0008] In the battery cell of the embodiments of this application, the electrode assembly is installed inside the housing. A first arc portion is provided between the first sidewall and the second sidewall of the housing. The first arc portion is smoothly connected to the first sidewall and the second sidewall, reducing stress concentration, improving the structural strength of the housing, and also facilitating the molding of the housing; the first arc portion is disposed opposite to the edge of the electrode assembly, and the first arc portion is provided with a first avoidance groove for avoiding the edge of the electrode assembly. The first avoidance groove can avoid the edge of the electrode assembly, reducing the interference risk 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, enabling a larger volume of electrode assembly to be installed inside the housing, which is beneficial to improving the volumetric energy density of the battery cell; in addition, during the expansion process of the electrode assembly, the avoidance space provided by the first avoidance groove can also reduce the interference amount between the electrode assembly and the first arc portion, reducing the risks of decarbonization and lithium plating caused by the interference between the electrode assembly and the first arc portion, which is beneficial to improving the charge and discharge performance of the battery cell.

[0009] In some embodiments, a second avoidance groove is provided at an edge of the first side wall near the first arc portion. The first avoidance groove and the second avoidance groove communicate with each other and jointly form an avoidance groove for avoiding the corresponding edge of the electrode assembly.

[0010] By adopting the technical solution of this embodiment, the avoidance groove extends to the first side wall, the thickness of the edge of the first side wall near the first arc portion can be reduced, and the molding of the outer shell can be facilitated.

[0011] In some embodiments, a third avoidance groove is provided at an edge of the second side wall near the first arc portion. The first avoidance groove and the third avoidance groove communicate with each other and jointly enclose an avoidance groove for avoiding the corresponding edge of the electrode assembly.

[0012] By adopting the technical solution of this embodiment, the avoidance groove extends to the second side wall, the thickness of the edge of the second side wall near the first arc portion can be reduced, and the molding of the outer shell can be facilitated.

[0013] In some embodiments, a second avoidance groove is provided at an edge of the first side wall near the first arc portion, and a third avoidance groove is provided at an edge of the second side wall near the first arc portion. The first avoidance groove, the second avoidance groove and the third avoidance groove communicate with each other and jointly enclose an avoidance groove for avoiding the corresponding edge of the electrode assembly.

[0014] By adopting the technical solution of this embodiment, the avoidance groove extends to the first side wall and the second side wall, the thickness of the edge of the first side wall near the first arc portion and the thickness of the edge of the second side wall near the first arc portion can be reduced, and the molding of the outer shell can be facilitated.

[0015] In some embodiments, the groove wall surface of the avoidance groove includes an arc surface, the arc surface is provided at the first arc portion, and the arc surface is connected between the inner wall surface of the first side wall and the inner wall surface of the second side wall.

[0016] By adopting the technical solution of this embodiment, the inner wall surface of the first side wall and the inner wall surface of the second side wall can be smoothly transitioned through the arc surface, which is beneficial to reducing stress concentration and improving the structural strength of the outer shell.

[0017] In some embodiments, the groove wall surface of the avoidance groove further includes a first connection surface, the first connection surface is provided on the first side wall, and the first connection surface is connected between the arc surface and the inner wall surface of the first side wall. The first connection surface is inclined or perpendicular to the inner wall surface of the first side wall.

[0018] By adopting the technical solution of this embodiment, the structural form of the avoidance groove can be flexibly set to meet different requirements.

[0019] In some embodiments, the groove wall surface of the avoidance groove further includes a first plane, the first plane is provided on the first side wall; the first plane is connected between the first connection surface and the arc surface, and the first plane is parallel to the inner wall surface of the first side wall.

[0020] By adopting the technical solution of this embodiment, the setting of the first plane enables a flat transition region between the arc surface and the first connection surface, facilitating the molding of the housing; in addition, the structure is regular and the processing is convenient.

[0021] In some embodiments, the other side of the arc surface is tangent to the inner wall surface of the second side wall.

[0022] By adopting the technical solution of this embodiment, the arc surface is tangent to the inner wall surface of the second side wall, and the arc surface is smoothly transitionally connected to the inner wall surface of the second side wall, which is beneficial to reducing stress concentration and improving the structural strength of the housing.

[0023] In some embodiments, a third avoidance groove is provided at the edge of the second side wall close to the first arc portion. The first avoidance groove, the second avoidance groove, and the third avoidance groove communicate with each other and jointly enclose an avoidance groove for avoiding the corresponding edge of the electrode assembly; the groove wall surface of the avoidance groove further includes a second connection surface, the second connection surface is provided on the second side wall, and the second connection surface is connected between the arc surface and the second side wall, and the second connection surface is inclined or perpendicular to the inner wall surface of the second side wall.

[0024] By adopting the technical solution of this embodiment, the structural form of the avoidance groove can be flexibly set to meet different requirements.

[0025] In some embodiments, the groove wall surface of the avoidance groove further includes a second flat surface, the second flat surface is provided on the second side wall, and the second flat surface is connected between the second connection surface and the arc surface, and the second flat surface is parallel to the inner wall surface of the second side wall.

[0026] By adopting the technical solution of this embodiment, the setting of the second flat surface enables a flat transition region between the arc surface and the second connection surface, facilitating the molding of the housing; in addition, the structure is regular and the processing is convenient.

[0027] In some embodiments, the radius of the arc surface is R 1 , and the dimension of the avoidance groove in the direction perpendicular to the inner wall surface of the second side wall is W, where 1 ≤ W / R 1 ≤ 3.

[0028] By adopting the technical solution of this embodiment, the dimension of the second avoidance groove is reasonably designed, and the structural strength of the housing and the molding of the housing can be taken into account simultaneously.

[0029] In some embodiments, 1.5 ≤ W / R 1 ≤ 2.5.

[0030] By adopting the technical solution of this embodiment, 1.5 ≤ W / R 1The design with ≤ 2.5 makes the size design of the second relief groove more reasonable, and can better balance the structural strength of the housing and the molding of the housing. In some embodiments, the groove wall surface of the relief groove includes a third plane, a fourth plane and a third connecting surface connected in sequence. The third plane is coplanar with the inner wall surface of the second side wall, the third plane is perpendicular to the fourth plane, and the third connecting surface is connected between the fourth plane and the inner wall surface of the first side wall.

[0031] By adopting the technical solution of this embodiment, the third plane and the fourth plane form a right-angle structure, which has a simple structure and is convenient for processing and manufacturing.

[0032] In some embodiments, the groove depth of the first relief groove is h 1 , and the wall thickness of the first side wall is H, where 0.02 ≤ h 1 / H ≤ 2 / 3.

[0033] By adopting the technical solution of this embodiment, the groove depth design of the first relief groove is reasonable, and it can balance the edge of the electrode assembly and the structural strength of the housing at the same time.

[0034] In some embodiments, 0.1 ≤ h 1 / H ≤ 0.5.

[0035] By adopting the technical solution of this embodiment, the design of 0.1 ≤ h 1 / H ≤ 0.5 makes the size design of the first relief groove more reasonable, and can better balance the edge of the electrode assembly and the structural strength of the housing.

[0036] In some embodiments, the groove depth of the first relief groove is h 1 , where 0.1 mm ≤ h 1 ≤ 0.5 mm.

[0037] By adopting the technical solution of this embodiment, the groove depth design of the first relief groove is reasonable, and it can balance the edge of the electrode assembly and the structural strength of the housing at the same time.

[0038] In some embodiments, 0.15 mm ≤ h 1 ≤ 0.35 mm.

[0039] By adopting the technical solution of this embodiment, the design of 0.15 mm ≤ h 1 ≤ 0.35 mm makes the size design of the first relief groove more reasonable, and can better balance the edge of the electrode assembly and the structural strength of the housing.

[0040] In some embodiments, the outer shell includes a housing and two end caps. The housing has openings on two end faces distributed oppositely along a first direction. The electrode assembly is located inside the housing, and the two end caps respectively cover the two openings. The two side walls of the housing distributed oppositely along a second direction are the first side walls, and the two side walls of the housing distributed oppositely along a third direction are the second side walls. A first arc portion is connected between the first side wall and the adjacent second side wall. The first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0041] By adopting the technical solution of this embodiment, a first avoidance groove is correspondingly provided for the edge of the electrode assembly extending along the first direction for avoidance, and the avoidance effect of the electrode assembly is good. The outer shell adopts the structural form of a housing and two end caps, with a simple structure, and the assembly and sealing of the battery cell are simple.

[0042] In some embodiments, the electrode assembly includes a plurality of electrode sheets, and the plurality of electrode sheets are stacked along the third direction.

[0043] By adopting the technical solution of this embodiment, the plurality of electrode sheets are stacked along the third direction, so that the electrode assembly has four edges extending along the second direction, and the first avoidance grooves of the four first arc portions connected between the first side wall and the second side wall can be arranged opposite to the four edges, thereby providing an avoidance space, reducing the interference risk between the electrode assembly and the outer shell, and being beneficial to improving the volumetric energy density and charge-discharge performance of the battery cell.

[0044] In some embodiments, the outer shell includes a housing and an end cap, and the electrode assembly is located inside the housing. One of the two end faces of the housing distributed oppositely along the first direction is provided with an opening, and the end cap covers the opening. The side wall of the housing opposite to the end cap is the first side wall, the two side walls of the housing distributed oppositely along the second direction are the second side walls, and the two side walls of the housing distributed oppositely along the third direction are the third side walls. First arc portions are respectively connected between the two opposite partial sides of the first side wall and the two second side walls. The first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0045] By adopting the technical solution of this embodiment, a first avoidance groove is correspondingly provided for the edge of the electrode assembly extending along the third direction for avoidance, and the avoidance effect of the electrode assembly is good. The outer shell adopts the structural form of a housing and one end cap, with a simple structure, and the assembly and sealing of the battery cell are simple.

[0046] In some embodiments, the electrode assembly is a wound structure, and the winding axis of the electrode assembly is parallel to the first direction; or, the electrode assembly is a wound structure, and the winding axis of the electrode assembly is parallel to the second direction; or, the electrode assembly includes a plurality of electrode sheets, and the plurality of electrode sheets are stacked along the first direction.

[0047] By adopting the technical solution of this embodiment, the outer shell can meet the avoidance requirements of electrode assemblies in various structural forms, and has a wide application range.

[0048] In some embodiments, the electrode assembly has a wound structure, the winding axis of the electrode assembly is parallel to the first direction, and the dimension of the electrode assembly in the second direction is L 1 , and the distance between the first avoidance groove and the adjacent third side wall is L 2 , where 1 / 15 ≤ L 2 / L 1 ≤ 0.5

[0049] By adopting the technical solution of this embodiment, the length of the first avoidance groove is reasonably designed, and the structural strength of the housing and the avoidance of the edges of the electrode assembly can be taken into account simultaneously

[0050] In some embodiments, 0.1 ≤ L 2 / L 1 ≤ 0.4

[0051] By adopting the technical solution of this embodiment, the design of 0.1 ≤ L 3 / L 1 ≤ 0.4 makes the length design of the first avoidance groove more reasonable, and the structural strength of the housing and the avoidance of the edges of the electrode assembly can be better taken into account

[0052] In some embodiments, the electrode assembly has a wound structure, the winding axis of the electrode assembly is parallel to the first direction, and the distance between the first avoidance groove and the adjacent third side wall is L 2 , where 3 mm ≤ L 2 ≤ 8 mm

[0053] By adopting the technical solution of this embodiment, the length of the first avoidance groove is reasonably designed, and the structural strength of the housing and the avoidance of the edges of the electrode assembly can be taken into account simultaneously

[0054] In some embodiments, 4 mm ≤ L 2 ≤ 6 mm

[0055] By adopting the technical solution of this embodiment, the design of 4 mm ≤ L 2 ≤ 6 mm makes the length design of the first avoidance groove more reasonable, and the structural strength of the housing and the avoidance of the edges of the electrode assembly can be better taken into account

[0056] In some embodiments, the electrode assembly has a wound structure, the winding axis of the electrode assembly is parallel to the first direction, and second arc-shaped portions are respectively connected between the opposite two sides of the first side wall and the two third side walls. A fourth avoidance groove is provided inside the second arc-shaped portion, and the fourth avoidance groove is used to avoid the vertex of the end portion of the electrode assembly adjacent to the second arc-shaped portion

[0057] By adopting the technical solution of this embodiment, the fourth avoidance groove of the second arc portion can avoid the vertex at the end of the electrode assembly. In this way, during the expansion process of the electrode assembly, the fourth avoidance groove can also provide an avoidance space for the vertex at the end of the electrode assembly, and can also reduce the interference amount between the electrode assembly and the second arc portion, reducing the risks of decarburization and lithium plating caused by the interference between the electrode assembly and the second arc portion, which is beneficial to improving the charge and discharge performance of the battery cell.

[0058] In some embodiments, the size of the electrode assembly in the second direction is L 1 , and the distance between the fourth avoidance groove and the adjacent second side wall is L 3 , where 1 / 15 ≤ L 3 / L 1 ≤ 0.5.

[0059] By adopting the technical solution of this embodiment, the length of the fourth avoidance groove is reasonably designed, which can take into account both the structural strength of the housing and the avoidance of the electrode assembly.

[0060] In some embodiments, 0.1 ≤ L 3 / L 1 ≤ 0.4.

[0061] By adopting the technical solution of this embodiment, the design of 0.1 ≤ L 3 / L 1 ≤ 0.4 makes the length design of the fourth avoidance groove more reasonable and can better take into account both the structural strength of the housing and the avoidance of the electrode assembly.

[0062] In some embodiments, the distance between the fourth avoidance groove and the adjacent second side wall is L 3 , where 3 mm ≤ L 3 ≤ 8 mm.

[0063] By adopting the technical solution of this embodiment, the length of the fourth avoidance groove is reasonably designed, which can take into account both the structural strength of the housing and the avoidance of the edge of the electrode assembly.

[0064] In some embodiments, 4 mm ≤ L 3 ≤ 6 mm.

[0065] By adopting the technical solution of this embodiment, the design of 4 mm ≤ L 3 ≤ 6 mm makes the length design of the fourth avoidance groove more reasonable and can better take into account both the structural strength of the housing and the avoidance of the electrode assembly.

[0066] In some embodiments, the depth of the fourth avoidance groove is h 2 , where 0.1 mm ≤ h 2 ≤ 0.3 mm.

[0067] By adopting the technical solution of this embodiment, the groove depth of the fourth avoidance groove is reasonably designed, which can take into account both the edge of the electrode assembly and the structural strength of the housing at the same time.

[0068] In some embodiments, a third arc portion is connected between the adjacent third side wall and the second side wall. The third arc portion and the first side wall are connected with a fourth arc portion. One end of the fourth arc portion is connected with the first arc portion, and the other end of the fourth arc portion is connected with the second arc portion. A communication groove is arranged inside the fourth arc portion, and the communication groove communicates the first avoidance groove and the fourth avoidance groove.

[0069] By adopting the technical solution of this embodiment, the third arc portion can smoothly connect the second side wall and the third side wall, and the fourth arc portion can smoothly connect the third arc portion and the first side wall, which can reduce stress concentration and facilitate the molding of the housing; the setting of the fourth avoidance groove enables the housing to have a whole-circle groove structure, which can reduce the thickness of the fourth arc portion, facilitate the molding of the housing, and the processing of the groove structure is also simpler.

[0070] In some embodiments, the groove depth of the first avoidance groove is h 1 , and the groove depth of the communication groove is h 3 , where 0.2 ≤ h 3 / h 1 ≤ 1.

[0071] By adopting the technical solution of this embodiment, the groove depth of the communication groove is reasonably designed, which makes the molding of the housing convenient and the housing has good structural strength at the corner, which is beneficial to improving the structural strength of the housing.

[0072] In some embodiments, 0.3 ≤ h 3 / h 1 ≤ 0.7.

[0073] By adopting the technical solution of this embodiment, the design of 0.3 ≤ h 3 / h 1 ≤ 0.7 makes the groove depth of the communication groove more reasonable, which makes the molding of the housing more convenient and the housing has better structural strength at the corner, which is beneficial to improving the structural strength of the housing.

[0074] In some embodiments, the groove depth of the communication groove is h 3 , where 0.1 mm ≤ h 3 ≤ 0.3 mm.

[0075] By adopting the technical solution of this embodiment, the groove depth of the communication groove is reasonably designed, which can take into account both the molding and the structural strength of the housing.

[0076] In a second aspect, a battery is provided, including the battery cell as described in the above embodiment.

[0077] The battery according to the embodiment of the present application uses the above-mentioned battery cell, and has a large volumetric energy density, good reliability in use, a long battery life, and good reliability in use.

[0078] In a third aspect, an electrical device is provided, including the battery as described in the above embodiment.

[0079] The electrical device according to the embodiment of the present application uses the above-mentioned battery, and has a large volumetric energy density, good reliability in use, a long battery life, and better performance of the electrical device.

[0080] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically illustrates the specific implementation manners of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0082] Figure 1 It is a schematic structural diagram of a vehicle provided by some embodiments of the present application.

[0083] Figure 2 It is a schematic structural diagram of a battery provided by some embodiments of the present application.

[0084] Figure 3 It is an exploded view of a battery cell provided by some embodiments of the present application.

[0085] Figure 4 For Figure 3 It is a schematic structural diagram of the battery cell after hiding the end cap as shown.

[0086] Figure 5 For the Figure 4 sectional view taken along line A-A in

[0087] Figure 6 For Figure 5 the partial enlarged view at B in

[0088] Figure 7 It is the partial enlarged view at B of the battery cell provided by some other embodiments of the present application in Figure 5

[0089] Figure 8 ​Exploded view of the battery cell provided by some other embodiments of the present application.

[0090] Figure 9 Exploded view of the housing of the battery cell provided by some embodiments of the present application.

[0091] Figure 10 Along Figure 9 Cross-sectional view taken along line C-C in

[0092] Figure 11 Is Figure 10 Partial enlarged view at D in

[0093] Figure 12 Partial enlarged view at D of the housing of the battery cell provided by some other embodiments of the present application in Figure 10 Partial enlarged view at D in

[0094] Figure 13 Partial enlarged view at D of the battery cell provided by some other embodiments of the present application in Figure 10 Partial enlarged view at D in

[0095] Figure 14 Partial enlarged view at D of the battery cell provided by some other embodiments of the present application in Figure 10 Partial enlarged view at D in

[0096] Figure 15 Structural schematic diagram of the housing of the battery cell provided by some embodiments of the present application.

[0097] Figure 16 Is Figure 15 Partial enlarged view at E in

[0098] Figure 17 Partial enlarged view at E of the housing of the battery cell provided by some other embodiments of the present application in Figure 15 Partial enlarged view at E in

[0099] Figure 18 Structural schematic diagram of the housing of the battery cell provided by some other embodiments of the present application.

[0100] Figure 19 Is Figure 18 Partial enlarged view at F in

[0101] Figure 20 Partial enlarged view at F of the housing of the battery cell provided by some other embodiments of the present application in Figure 18 Partial enlarged view at F in

[0102] Figure 21 Along Figure 18 Cross-sectional view taken along line G-G in

[0103] Figure 22 Is Figure 21Partial enlarged view at H in the middle.

[0104] Figure 23 Exploded view of a battery cell provided by some other embodiments of the present application.

[0105] Figure 24 Exploded view of a battery cell provided by some other embodiments of the present application.

[0106] Among them, the reference numerals in the figure are as follows:

[0107] 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, tab; 20, housing; 21, end cap; 211, electrode terminal; 212, pressure relief mechanism; 22, shell; 221, first side wall; 2211, second avoidance groove; 222, second side wall; 2221, third avoidance groove; 223, third side wall; 224, first arc portion; 2241, first avoidance groove; 225, second arc portion; 2251, fourth avoidance groove; 226, third arc portion; 227, fourth arc portion; 2271, communication groove; 228, avoidance groove; 2281, arc surface; 2282, first connection surface; 2283, first plane; 2284, second connection surface; 2285, second plane; 2286, third plane; 2287, fourth plane; 2288, third connection surface; 30, insulating film; 200, box body; 210, first part; 220, second part. Detailed implementation manners

[0108] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, the present application will be further described in detail below with reference to 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.

[0109] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0110] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary-secondary relationship of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0111] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least some embodiments of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive of other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments in any suitable manner.

[0112] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0113] In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces). The meaning of "several" is one or more, unless otherwise specifically defined.

[0114] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the embodiments of the present application.

[0115] In the description of the embodiments of the present application, unless otherwise clearly specified or limited, technical terms such as "installation", "connection", "coupling", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0116] In the description of the embodiments of the present application, unless otherwise clearly specified or limited, when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0117] Currently, from the perspective of 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 hydraulic, thermal, wind, and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in many fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also continuously increasing.

[0118] A battery generally includes one or more battery cells, and the number of battery cells can be set according to the power demand. Each battery cell includes a housing and an electrode assembly. The electrode assembly is disposed inside the housing. Usually, the adjacent two side walls of the housing are smoothly connected by an arc portion (also called an R corner) to reduce stress concentration and improve the structural strength of the housing. The edge of the electrode assembly is disposed opposite to the arc portion. In order to avoid interference between the edge 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 edge of the electrode assembly is away from the arc portion. However, the insulating plate occupies a part of the internal space of the housing, thus limiting the improvement of the volume energy density of the battery cell.

[0119] Based on this, in order to improve the volumetric energy density of the battery cell, an embodiment of the present application provides a battery cell. The electrode assembly is installed inside the housing. A first arc portion is provided between the first side wall and the second side wall of the housing. The first arc portion is smoothly connected to the first side wall and the second side wall, reducing stress concentration, improving the structural strength of the housing, and also facilitating the molding of the housing. The first arc portion is disposed opposite to the edge of the electrode assembly, and the first arc portion is provided with a first avoidance groove for avoiding the edge of the electrode assembly. The first avoidance groove can clear the edge of the electrode assembly, reducing the interference risk 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, enabling a larger volume of the electrode assembly to be installed inside the housing, which is beneficial to improving the volumetric energy density of the battery cell. Additionally, during the expansion process of the electrode assembly, the avoidance space provided by the first avoidance groove can also reduce the interference amount between the electrode assembly and the first arc portion, reducing risks such as decarburization and lithium plating caused by the interference between the electrode assembly and the first arc portion, which is beneficial to improving the charge and discharge performance of the battery cell.

[0120] The battery cell, battery, and electrical device of the embodiments of the present application are described below.

[0121] The electrical device of the embodiments of the present application can be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, the electric toy can include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc. The electrical device can be an energy storage device, such as an energy storage container, an energy storage electrical cabinet, etc.

[0122] For the convenience of description in the following embodiments, the electrical device is taken as an example of a vehicle for illustration.

[0123] Please refer to Figure 1 , the vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc. The vehicle 1000 is internally provided with a battery 1100, and the battery 1100 can be arranged at the bottom, head, or tail of the vehicle 1000. The battery 1100 can be used for power supply of the vehicle 1000. For example, the battery 1100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 can also include a controller 1200 and a motor 1300. The controller 1200 is used to control the battery 1100 to supply power to the motor 1300. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0124] 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 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.

[0125] Please refer to Figure 2 , the battery 1100 includes a box body 200 and battery cells 100, and the battery cells 100 are accommodated in the box body 200. Among them, the box body 200 is used to provide an accommodation space for the battery cells 100, and the box body 200 can adopt various structures.

[0126] Exemplarily, the box body 200 can include a first part 210 and a second part 220. The first part 210 and the second part 220 are covered with each other, and the first part 210 and the second part 220 jointly define an accommodation space for accommodating the battery cells 100. The second part 220 can be a hollow structure with one end open, and the first part 210 can be a plate-like structure. The first part 210 is covered on the open side of the second part 220 so that the first part 210 and the second part 220 jointly define an accommodation space; the first part 210 and the second part 220 can also both be hollow structures with one side open, and the open side of the first part 210 is covered on 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 can be various shapes, such as a cylinder, a cuboid, etc.

[0127] In the battery 1100, there can be multiple battery cells 100, and the multiple battery cells 100 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 100.

[0128] In some embodiments, the multiple battery cells 100 can be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 100 is accommodated in the box body 200; of course, the battery 1100 can also be that multiple battery cells 100 are first connected in series, in parallel, or in a mixed connection to form a battery module form, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole and are accommodated in the box body 200. The battery 1100 can also include other structures. For example, the battery 1100 can also include a busbar component for realizing the electrical connection among the multiple battery cells 100.

[0129] Among them, each battery cell 100 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell. The battery cell 100 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0130] In some embodiments, the battery 1100 may not include the housing 200. Instead, a plurality of battery cells 100 are electrically connected and assembled into an electrical device as a whole through necessary fixing structures.

[0131] The following will describe the battery cell 100 of the embodiments of the present application in conjunction with Figures 3 - 24 the battery cell 100 of the embodiments of the present application.

[0132] For the convenience of understanding and description, in the embodiments provided by the present application, only the battery cell 100 in the shape of a cuboid is described. It should be understood that the embodiments provided by the present application are also applicable to the battery cell 100 in the shape of a cylinder or a prism.

[0133] Referring to Figures 3 - 24 as shown, the battery cell 100 has a height direction, a length direction, and a width direction. The outer shell 20 defines the outer shape structure of the battery cell 100. The height direction of the outer shell 20 can be the height direction of the battery cell 100, the length direction of the outer shell 20 is the length direction of the battery cell 100, and the width direction of the outer shell 20 is the width direction of the battery cell 100.

[0134] Exemplarily, referring to Figures 3 - 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.

[0135] Exemplarily, referring to Figures 8 - 23 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.

[0136] Exemplarily, referring to Figure 24 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.

[0137] Referring to Figures 3 - 6 as shown, in some embodiments of the present application, a battery cell 100 is provided. The battery cell 100 includes an electrode assembly 10 and an outer shell 20. The electrode assembly 10 is located inside the outer shell 20. The outer 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 disposed opposite to the edge 10a of the electrode assembly 10, and at least a part of the first arc portion 224 is provided with a first avoidance groove 2241 for avoiding the corresponding edge 10a of the electrode assembly 10.

[0138] The outer shell 20 refers to a housing 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. In this way, when the outer shell 20 is squeezed or collided, it is not easily deformed, enabling the battery cell 100 to have higher structural strength and improved reliability. The material of the outer shell 20 can be various, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0139] In some examples, the outer shell 20 can be a sealed structure or a non-sealed structure. As an example, when the outer shell 20 is a sealed structure, the outer shell 20 can protect the electrode assembly 10 and prevent, for example, electrolyte leakage. When the outer shell 20 is a non-sealed structure, the outer shell 20 can protect the electrode assembly 10, and a sealing bag can also be included between the outer shell 20 and the electrode assembly 10. The sealing bag is used to encapsulate the electrode assembly 10 and the electrolyte, etc. Specifically, the sealing bag can be a bag-shaped insulating part or an aluminum-plastic film.

[0140] Exemplarily, referring to Figure 3 As shown, the outer shell 20 includes a housing 22 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 cooperate with the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, when the end cap 21 is squeezed or collided, it is not easily deformed, enabling the battery cell 100 to have higher structural strength and improved reliability. The material of the end cap 21 can also be various, for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0141] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 100, where the formed internal environment can be used to accommodate the electrode assembly 10. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 is covered at the opening to form the internal environment of the battery cell 100. Without limitation, the end cap 21 and the housing 22 can also be integrated; the end cap 21 and the housing 22 can form a common connection surface before other components are inserted into the housing, and when it is necessary to encapsulate the inside of the housing 22, the end cap 21 is then covered on the housing 22. The shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 10. The material of the housing 22 can be various, for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. Exemplarily, the number of end caps 21 is one or two.

[0142] Exemplarily, referring to Figure 3 、 Figure 8 、 Figure 23 and Figure 24As shown, the shape of the housing 22 defines the shape of the outer casing 20. The height direction of the housing 22 is the height direction of the outer casing 20, the width direction of the housing 22 is the width direction of the outer casing 20, and the length direction of the housing 22 is the length direction of the outer casing 20.

[0143] The electrode assembly 10 is a component in the battery cell 100 where an electrochemical reaction occurs. One or more electrode assemblies 10 can be included within the outer casing 20.

[0144] Exemplarily, the electrode assembly 10 includes a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell 100 mainly operates by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the coated positive electrode active material layer protrudes from the positive electrode current collector with the coated positive electrode active material layer, and the positive electrode current collector without the coated positive electrode active material layer serves as the positive electrode tab. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the coated negative electrode active material layer protrudes from the negative electrode current collector with the coated negative electrode active material layer, and the negative electrode current collector without the coated negative electrode active material layer serves as the negative electrode tab.

[0145] Taking a lithium-ion battery cell as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon, silicon, lithium metal, lithium alloy, etc. To ensure that large currents can pass through without fusing, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the separator can be polypropylene (PP), polyethylene (PE), etc. In addition, the electrode assembly 10 in the embodiments of the present application includes, but is not limited to, a wound structure or a stacked structure. For the convenience of description, hereinafter, the positive electrode sheet and the negative electrode sheet are collectively referred to as the electrode sheet 11, and the positive electrode tab and the negative electrode tab are collectively referred to as the electrode tab 12.

[0146] The edge 10a of the electrode assembly 10 can refer to the intersection line formed by two adjacent surfaces of the electrode assembly 10, and this intersection line is likely to interfere with the outer casing 20.

[0147] Among two adjacent side walls of the outer casing 20, one side wall is the first side wall 221, and the other side wall is the 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 can refer to a structure for smoothly connecting the first side wall 221 and the second side wall 222 in a transitional manner; after the electrode assembly 10 is installed in the outer casing 20, the edge 10a of the electrode assembly 10 is disposed opposite to the first arc portion 224.

[0148] Exemplarily, refer to Figure 6 , Figure 7 , Figures 11 - 14 As shown, the first arc portion 224 is a chamfered corner structure, and the first arc portion 224 can also be referred to as an R corner. The chamfered corner structure closest to the edge 10a of the electrode assembly 10 can be called the first arc portion 224. The demarcation line between the first side wall 221 and the first arc portion 224 can be referred to as the dotted line N in the figure, and the demarcation line between the second side wall 222 and the first arc portion 224 can be referred to as the dotted line M in the figure.

[0149] Exemplarily, refer to Figure 3 As shown, the electrode assembly 10 is a stacked structure. The electrode assembly 10 includes a plurality of electrode plates 11, and the plurality of electrode plates 11 are stacked along the height direction of the battery cell 100; two end caps 21 are respectively disposed at the left and right openings of the housing 22. After the electrode assembly 10 is placed in the housing 22, the two edges of the electrode plates 11 at the lower side that are relatively distributed along the width direction of the battery cell 100 and the two edges of the electrode plates 11 at the upper side that are relatively distributed along the width direction of the battery cell 100 are likely to interfere with the outer shell 20. The two edges of the electrode plates 11 at the lower side 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 electrode plates 11 at 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 housing 22 can be called the second side wall 222, the front wall and the rear wall of the housing 22 can be called the first side wall 221, and the four chamfered corner structures connected between the first side wall 221 and the second side wall 222 can be called the first arc portion 224.

[0150] Exemplarily, refer to Figure 23 As shown, the electrode assembly 10 is a stacked structure. The electrode assembly 10 includes a plurality of electrode plates 11, and the plurality of electrode plates 11 are stacked along the height direction of the battery cell 100; the end cap 21 is disposed at the upper opening of the housing 22. After the electrode assembly 10 is placed in the housing 22, the edges of the electrode plates 11 at the lower side that are relatively distributed along the width direction of the battery cell 100 are likely to interfere with the housing 22. The two edges of the electrode plates 11 at the lower side that are relatively distributed along the width direction of the battery cell 100 are called the edges 10a of the electrode assembly 10. The bottom wall of the housing 22 can be called the first side wall 221, the left wall and the right wall of the housing 22 can be called the second side wall 222, and the two chamfered corner structures connected between the first side wall 221 and the second side wall 222 can be called the first arc portion 224.

[0151] Exemplarily, refer to Figure 8As shown, the electrode assembly 10 can be in a wound flat structure. The end cap 21 covers the upper opening of the housing 22. After the electrode assembly 10 is placed into the housing 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 tab 12 is led out from the top surface of the electrode assembly 10. Among the side edges 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 into the outer shell 20, the long straight line 10c is likely to interfere with the outer shell 20, and the long straight line 10c can be referred to as the edge 10a of the electrode assembly 10. The long straight line 10c can refer to the side edges where the bottom ends of the outermost layer of electrode plates 11 or diaphragms of the electrode assembly 10 extend along the length direction of the battery cell 100. The bottom wall of the housing 22 can be referred to as the first side wall 221, the front wall and the rear wall of the housing 22 can be referred to as the second side walls 222, and the two rounded corner structures connecting the first side wall 221 and the second side walls 222 can be referred to as the first arc portions 224.

[0152] Exemplarily, refer to Figure 24 As shown, the electrode plates 11 of the electrode assembly 10 can be in a wound flat structure. The end cap 21 covers the right opening of the housing 22. After the electrode assembly 10 is placed into the housing 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 tab 12 is led out from the right side of the top surface of the electrode assembly 10. Among the side edges 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. Among the side edges 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. Among them, after the electrode assembly 10 is installed into the outer shell 20, the long straight lines 10c on the left side of the top and bottom of the electrode assembly 10 are likely to interfere with the outer shell 20, and the long straight lines 10c on the left side of the top and bottom of the electrode assembly 10 can be referred to as the edges 10a of the electrode assembly 10. The long straight line 10c can refer to the side edges where the top and bottom ends of the outermost layer of electrode plates 11 or diaphragms of the electrode assembly 10 extend along the length direction of the battery cell 100. The left wall of the housing 22 can be referred to as the first side wall 221, the bottom wall and the top wall of the housing 22 can be referred to as the second side walls 222, and the two rounded corner structures connecting the first side wall 221 and the second side walls 222 can be referred to as the first arc portions 224.

[0153] At least a partial section of the first arc portion 224 is provided with a first avoidance groove 2241 for avoiding the corresponding edge 10a of the electrode assembly 10. It can be understood that the first avoidance groove 2241 is provided on the inner side of the first arc portion 224, and the first avoidance groove 2241 is disposed opposite to the edge 10a of the electrode assembly 10, and the first avoidance groove 2241 can avoid the edge 10a of the electrode assembly 10; the first arc portion 224 may be provided with the first avoidance groove 2241 in a partial section, or may be provided with the first avoidance groove 2241 in all sections, that is, the first avoidance groove 2241 may penetrate through the first arc portion 224.

[0154] Exemplarily, referring to Figure 3 and Figure 4 As shown, the length of the first arc portion 224 is greater than the length of the corresponding edge 10a of the electrode assembly 10. Among them, the section of the first arc portion 224 corresponding to the electrode assembly 10 may be provided with the first avoidance groove 2241, or the entire section of the first arc portion 224 may be provided with the first avoidance groove 2241. The length of the first avoidance groove 2241 may be greater than or equal to the length of the edge 10a of the electrode assembly 10 to avoid the entire edge 10a of the electrode assembly 10.

[0155] Exemplarily, the first avoidance groove 2241 penetrates through the first arc portion 224 along the length direction of the first arc portion 224.

[0156] Of course, in other examples, the length of the first avoidance groove 2241 may also be less than the length of the edge 10a of the electrode assembly 10 to avoid a partial section of the edge 10a of the electrode assembly 10.

[0157] In the battery cell 100 of the embodiment of the present application, the electrode assembly 10 is installed in the housing 20. A first arc portion 224 is provided between the first side wall 221 and the second side wall 222 of the housing 20. The first arc portion 224 is smoothly connected to the first side wall 221 and the second side wall 222, reducing stress concentration, improving the structural strength of the housing 20, and also facilitating the molding of the housing 20; the first arc portion 224 is disposed opposite to the edge 10a of the electrode assembly 10, and the first arc portion 224 is provided with a first avoidance groove 2241 for avoiding the edge 10a of the electrode assembly 10. The first avoidance groove 2241 can avoid the edge 10a of the electrode assembly 10, reducing the interference risk 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 the electrode assembly 10 can be installed in the housing 20, which is beneficial to improving the volumetric energy density of the battery cell 100; in addition, during the expansion process of the electrode assembly 10, the avoidance space provided by the first avoidance groove 2241 can also reduce the interference amount between the electrode assembly 10 and the first arc portion 224, reducing risks such as decarbonization and lithium plating caused by the interference between the electrode assembly 10 and the first arc portion 224, which is beneficial to improving the charge and discharge performance of the battery cell 100.

[0158] In some embodiments, the battery cell 100 further includes electrode terminals 211. The electrode terminals 211 can be disposed on the end cap 21 or on the housing 22. The number of the electrode terminals 211 is two, and the two electrode terminals 211 are electrically connected to the positive electrode tab and the negative electrode tab respectively, so that the battery cell 100 outputs or inputs electric energy.

[0159] In some embodiments, the battery cell 100 further includes a pressure relief mechanism 212. The pressure relief mechanism 212 can be disposed on the end cap 21 or on the housing 22. The pressure relief mechanism 212 can be an explosion-proof valve, an explosion-proof sheet, etc.

[0160] In some embodiments, the battery cell 100 further includes an insulating member. The insulating member can be disposed inside the end cap 21 to isolate the electrical connection components inside the housing 22 from the end cap 21, so as to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0161] In some embodiments, the electrode assembly 10 is further coated with an insulating film 30. The insulating film 30 is used to insulate and separate the electrode assembly 10 from the outer shell 20, reduce the risk of short circuit, and is beneficial to improving the use reliability of the battery cell 100; the material of the insulating film 30 can be plastic.

[0162] In other embodiments of the present application, refer to Figures 4 - 6 As shown, a second avoidance groove 2211 is provided at the edge of the first side wall 221 close to the first arc portion 224. The first avoidance groove 2241 communicates with the second avoidance groove 2211 and jointly forms an avoidance groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10.

[0163] The avoidance groove 228 can refer to a groove structure provided inside the outer shell 20 for avoiding the edge 10a of the electrode assembly 10; the avoidance groove 228 extends from the first arc portion 224 to the first side wall 221, and the part of the avoidance groove 228 located on the first side wall 221 is the second avoidance groove 2211, and the part of the avoidance groove 228 located on the first arc portion 224 is the first avoidance groove 2241.

[0164] By adopting the technical solution of this embodiment, the avoidance groove 228 extends to the first side wall 221, the thickness of the edge of the first side wall 221 close to the first arc portion 224 can be reduced, and the forming of the outer shell 20 can be facilitated.

[0165] In other embodiments of the present application, refer to Figure 7 As shown, a third avoidance groove 2221 is provided at the edge of the second side wall 222 close to the first arc portion 224. The first avoidance groove 2241 and the third avoidance groove 2221 communicate with each other and jointly enclose an avoidance groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10.

[0166] The avoidance groove 228 extends from the first arc portion 224 to the second side wall 222. The portion of the avoidance groove 228 located on the second side wall 222 is the third avoidance groove 2221, and the portion of the avoidance groove 228 located on the first arc portion 224 is the first avoidance groove 2241.

[0167] By adopting the technical solution of this embodiment, the avoidance groove 228 extends to the second side wall 222, which can reduce the thickness of the edge of the second side wall 222 close to the first arc portion 224, and facilitate the molding of the housing 20.

[0168] In some other embodiments of the present application, refer to Figure 7 As shown, a second avoidance groove 2211 is provided on the edge of the first side wall 221 close to the first arc portion 224, and a third avoidance groove 2221 is provided on the edge of the second side wall 222 close to the first arc portion 224. The first avoidance groove 2241, the second avoidance groove 2211, and the third avoidance groove 2221 communicate with each other and jointly enclose an avoidance groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10.

[0169] The avoidance groove 228 extends from opposite sides of the first arc portion 224 to the first side wall 221 and the second side wall 222 respectively. The portion of the avoidance groove 228 located on the first side wall 221 is the second avoidance groove 2211, the portion of the avoidance groove 228 located on the first arc portion 224 is the first avoidance groove 2241, and the portion of the avoidance groove 228 located on the second side wall 222 is the third avoidance groove 2221.

[0170] By adopting the technical solution of this embodiment, the avoidance groove 228 extends to the first side wall 221 and the second side wall 222, which can reduce the thickness of the edge of the first side wall 221 close to the first arc portion 224 and the thickness of the edge of the second side wall 222 close to the first arc portion 224, and facilitate the molding of the housing 20.

[0171] In some other embodiments of the present application, refer to Figure 6 As shown, the groove wall surface of the avoidance groove 228 includes an arc surface 2281. The arc surface 2281 is provided on the first arc portion 224, and the arc surface 2281 is connected between the inner wall surfaces of the first side wall 221 and the second side wall 222.

[0172] The inner wall surface of the first side wall 221 may refer to the wall surface of the first side wall 221 facing the electrode assembly 10; in the case where the second avoidance groove 2211 is provided on the first side wall 221, the inner wall surface of the first side wall 221 may also refer to the area of the wall surface of the first side wall 221 facing the electrode assembly 10 excluding the second avoidance groove 2211.

[0173] The inner wall surface of the second side wall 222 may refer to the wall surface of the second side wall 222 facing the electrode assembly 10; in the case where a third avoidance groove 2221 is provided in the second side wall 222, the inner wall surface of the second side wall 222 may also refer to the area of the wall surface of the second side wall 222 facing the electrode assembly 10 excluding the third avoidance groove 2221.

[0174] The arc surface 2281 may refer to the side surface of the first arc portion 224 facing the electrode assembly 10, that is, the inner side surface of the first arc portion 224, and the shape of the inner side surface of the first arc portion 224 may be an arc cylindrical shape.

[0175] By adopting the technical solution of this embodiment, the inner wall surface of the first side wall 221 and the inner wall surface of the second side wall 222 can be smoothly transitioned through the arc surface 2281, which is beneficial to reducing stress concentration and improving the structural strength of the housing 20.

[0176] In some other embodiments of the present application, refer to Figures 8 - 13 As shown, the groove wall surface of the avoidance groove 228 further includes a first connection surface 2282. The first connection surface 2282 is provided on the first side wall 221. The first connection surface 2282 is connected between the arc surface 2281 and the inner wall surface of the first side wall 221. The first connection surface 2282 is inclined or perpendicular to the inner wall surface of the first side wall 221.

[0177] The first connection surface 2282 may refer to the surface located between the inner wall surface of the first side wall 221 and the arc surface 2281. The first connection surface 2282 is located on the first side wall 221.

[0178] The first connection surface 2282 may be inclined relative to the inner wall surface of the first side wall 221, that is, an angle is formed between the first connection surface 2282 and the inner wall surface of the first side wall 221, and this angle is an acute angle or an obtuse angle; the first connection surface 2282 forms at least part of the groove wall surface of the second avoidance groove 2211.

[0179] The first connection surface 2282 may be perpendicular to the inner wall surface of the first side wall 221, that is, the first connection surface 2282 and the inner wall surface of the first side wall 221 are perpendicular to each other, with a simple structure and convenient processing and manufacturing.

[0180] In a possible embodiment, refer to Figure 13 As shown, the groove wall surface of the avoidance groove 228 further includes a first connection surface 2282. The first connection surface 2282 is provided on the first side wall 221. The first connection surface 2282 is connected between the arc surface 2281 and the inner wall surface of the first side wall 221. The first connection surface 2282 is inclined relative to the inner wall surface of the first side wall 221, and a chamfer structure can be formed, which can reduce stress concentration and improve the structural strength of the housing 20.

[0181] Exemplarily, refer to Figure 13As shown, the two opposite sides of the first connecting surface 2282 are directly connected to the edge of the arc surface 2281 and the edge of the inner wall surface of the first side wall 221. The structure is simple and easy to manufacture.

[0182] In another possible embodiment, refer to Figure 11 and Figure 12 As shown, the groove wall surface of the avoidance groove 228 further includes a first connecting surface 2282. The first connecting surface 2282 is provided on the first side wall 221. The first connecting surface 2282 is connected between the arc surface 2281 and the inner wall surface of the first side wall 221. The first connecting surface 2282 is perpendicular to the inner wall surface of the first side wall 221. The structure is simple and convenient for processing and manufacturing.

[0183] By adopting the technical solution of this embodiment, the structural form of the avoidance groove 228 can be flexibly set to meet different requirements.

[0184] In some other embodiments of the present application, refer to Figure 6 、 Figure 11 and Figure 12 As shown, the groove wall surface of the avoidance groove 228 further includes a first plane 2283. The first plane 2283 is provided on the first side wall 221. The first plane 2283 is connected between the first connecting surface 2282 and the arc surface 2281. The first plane 2283 is parallel to the inner wall surface of the first side wall 221.

[0185] The first plane 2283 may refer to the plane connected between the arc surface 2281 and the first connecting surface 2282, and this plane is parallel or nearly parallel to the inner wall surface of the first side wall 221.

[0186] Exemplarily, refer to Figure 6 As shown, the first plane 2283 is located on the first side wall 221. The first plane 2283 and the first connecting surface 2282 together form the groove wall surface of the second avoidance groove 2211; the first plane 2283 can be the groove bottom surface of the second avoidance groove 2211.

[0187] By adopting the technical solution of this embodiment, the setting of the first plane 2283 makes there be a flat transition area between the arc surface 2281 and the first connecting surface 2282, which is convenient for the molding of the housing 20; in addition, the structure is regular and convenient for processing.

[0188] In some other embodiments of the present application, refer to Figure 6 、 Figure 11 and Figure 12 As shown, the other side of the arc surface 2281 is tangent to the inner wall surface of the second side wall 222.

[0189] The inner wall surface of the second side wall 222 is distributed along the arc surface 2281 in the tangential direction. That is, the third avoidance groove 2221 is not provided on the second side wall 222, and the arc surface 2281 is smoothly connected to the inner wall surface of the second side wall 222.

[0190] By adopting the technical solution of this embodiment, the arc surface 2281 is tangent to the inner wall surface of the second side wall 222, and the arc surface 2281 is smoothly connected to the inner wall surface of the second side wall 222, which is beneficial to reducing stress concentration and improving the structural strength of the housing 20.

[0191] In some embodiments, referring to Figure 11 and Figure 12 as shown, both the first plane 2283 and the inner wall surface of the second side wall 222 are tangent to the arc surface 2281. In this way, the arc surface 2281 can retain a complete quarter - arc shape, so that the first arc portion 224 can retain a complete rounded - corner structure. Its structure is regular and simple, convenient for processing and manufacturing, and is also beneficial to improving the structural strength of the housing 20. Of course, the first plane 2283 may not be tangent to the arc surface 2281.

[0192] In other embodiments of the present application, referring to Figure 7 as shown, a third avoidance groove 2221 is provided at the edge of the second side wall 222 close to the first arc portion 224. The first avoidance groove 2241, the second avoidance groove 2211, and the third avoidance groove 2221 communicate with each other and jointly enclose an avoidance groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10; the groove wall surface of the avoidance groove 228 further includes a second connection surface 2284. The second connection surface 2284 is provided on the second side wall 222, and the second connection surface 2284 is connected between the arc surface 2281 and the second side wall 222. The second connection surface 2284 is inclined or perpendicular to the inner wall surface of the second side wall 222.

[0193] The second connection surface 2284 may refer to the surface located between the inner wall surface of the second side wall 222 and the arc surface 2281, and the second connection surface 2284 is located on the second side wall 222.

[0194] The second connection surface 2284 can be inclined with respect to the inner wall surface of the second side wall 222, that is, an angle is formed between the second connection surface 2284 and the inner wall surface of the second side wall 222, and this angle is an acute angle or an obtuse angle; the second connection surface 2284 forms at least part of the groove wall surface of the third avoidance groove 2221.

[0195] The second connection surface 2284 can be perpendicular to the inner wall surface of the second side wall 222, that is, the second connection surface 2284 is perpendicular to the inner wall surface of the second side wall 222, with a simple structure and convenient for processing and manufacturing.

[0196] In a possible embodiment, referring to Figure 7As shown, a third relief groove 2221 is provided at an edge of the second side wall 222 close to the first arc portion 224. The first relief groove 2241, the second relief groove 2211, and the third relief groove 2221 communicate with each other and jointly enclose a relief groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10; the groove wall surface of the relief groove 228 further includes a second connection surface 2284, and the second connection surface 2284 is provided on the second side wall 222. The second connection surface 2284 is connected between the arc surface 2281 and the second side wall 222. The second connection surface 2284 is inclined relative to the inner wall surface of the second side wall 222, and a chamfer structure can be formed, thus reducing stress concentration and improving the structural strength of the housing 20.

[0197] In another possible embodiment, a third relief groove 2221 is provided at an edge of the second side wall 222 close to the first arc portion 224. The first relief groove 2241, the second relief groove 2211, and the third relief groove 2221 communicate with each other and jointly enclose a relief groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10; the groove wall surface of the relief groove 228 further includes a second connection surface 2284, and the second connection surface 2284 is provided on the second side wall 222. The second connection surface 2284 is connected between the arc surface 2281 and the second side wall 222. The second connection surface 2284 is perpendicular to the inner wall surface of the second side wall 222, with a simple structure and convenient processing and manufacturing.

[0198] By adopting the technical solution of this embodiment, the structural form of the relief groove 228 can be flexibly set to meet different requirements.

[0199] In other embodiments of the present application, refer to Figure 7 、 Figure 11 and Figure 12 As shown, the groove wall surface of the relief groove 228 further includes a second plane 2285, and the second plane 2285 is provided on the second side wall 222. The second plane 2285 is connected between the second connection surface 2284 and the arc surface 2281, and the second plane 2285 is parallel to the inner wall surface of the second side wall 222.

[0200] The second plane 2285 may refer to a plane connected between the arc surface 2281 and the second connection surface 2284, and this plane is parallel or nearly parallel to the inner wall surface of the second side wall 222.

[0201] Exemplarily, refer to Figure 7 As shown, the second plane 2285 is located on the second side wall 222, and the second plane 2285 and the second connection surface 2284 jointly form the groove wall surface of the third relief groove 2221; the second plane 2285 can be the groove bottom surface of the third relief groove 2221.

[0202] By adopting the technical solution of this embodiment, the arrangement of the second plane 2285 enables a flat transition region between the arc surface 2281 and the second connection surface 2284, facilitating the molding of the housing 20; in addition, the structure is regular and the processing is convenient.

[0203] In some embodiments, referring to Figure 7 as shown, both the first plane 2283 and the second plane 2285 are tangent to the arc surface 2281, so that the arc surface 2281 can retain a complete quarter - arc shape, enabling the first arc portion 224 to retain a complete rounded - corner structure. Its structure is regular and simple, and the processing and manufacturing are convenient. Of course, in other embodiments, the first plane 2283 may not be tangent to the arc surface 2281, and the second plane 2285 may not be tangent to the arc surface 2281 either.

[0204] In other embodiments of the present application, referring to Figure 6 and Figure 7 as shown, the radius of the arc surface 2281 is R 1 , and the dimension of the avoidance groove 228 in the direction perpendicular to the inner wall surface of the second side wall 222 is W, where 1 ≤ W / R 1 ≤ 3.

[0205] The direction perpendicular to the inner wall surface of the second side wall 222 can refer to the Z - direction in Figure 6.

[0206] 1 ≤ W / R 1 ≤ 3. It can be understood that W / R 1 ≥ 1 can enable the first side wall 221 to be provided with the second avoidance groove 2211, which can reduce the thickness of the first side wall 221 near the first arc portion 224, facilitating the molding of the housing 20; W / R 1 ≤ 3, the dimension of the second avoidance groove 2211 will not be too large, and the thinning area of the first side wall 221 will not be too large, enabling the first side wall 221 to have appropriate structural strength to protect the electrode assembly 10.

[0207] By adopting the technical solution of this embodiment, the dimension design of the second avoidance groove 2211 is reasonable, which can take into account both the structural strength of the housing 20 and the molding of the housing 20.

[0208] In other embodiments of the present application, referring to Figure 6 and Figure 7 as shown, 1.5 ≤ W / R 1 ≤ 2.5.

[0209] By adopting the technical solution of this embodiment, the design of 1.5 ≤ W / R 1 ≤ 2.5 makes the dimension design of the second avoidance groove 2211 more reasonable, which can better take into account both the structural strength of the housing 20 and the molding of the housing 20.

[0210] In some embodiments, W / R 1 may have a value of 1, 3, or any number between 1 and 3. By way of example, W / R 1 may have a value of, but not limited to, 1, 1.2, 1.4, 1.5, 1.7, 1.9, 2.1, 2.3, 2.5, 2.7, 2.9, 3.

[0211] In some other embodiments of the present application, referring to Figure 14 as shown, the groove wall surface of the avoidance groove 228 includes a third plane 2286, a fourth plane 2287, and a third connection surface 2288 that are sequentially connected. The third plane 2286 is coplanar with the inner wall surface of the second side wall 222. The third plane 2286 is perpendicular to the fourth plane 2287. The third connection surface 2288 is connected between the fourth plane 2287 and the inner wall surface of the first side wall 221.

[0212] The third plane 2286 may refer to the surface that is coplanar with the inner wall surface of the second side wall 222. The fourth plane 2287 is perpendicular to the third plane 2286. The third connection surface 2288 is connected between the fourth plane 2287 and the inner wall surface of the first side wall 221. By way of example, a part of the third plane 2286 and the fourth plane 2287 forms the groove wall surface of the first avoidance groove 2241, and another part of the fourth plane 2287 and the third connection surface 2288 form the groove wall surface of the second avoidance groove 2211. The third connection surface 2288 may be inclined or perpendicular to the inner wall surface of the first side wall 221.

[0213] By adopting the technical solution of this embodiment, the third plane 2286 and the fourth plane 2287 form a right-angle structure, which has a simple structure and is convenient for processing and manufacturing.

[0214] In some other embodiments of the present application, referring to Figure 6 and Figure 7 as shown, the groove depth of the first avoidance groove 2241 is h 1 , and the wall thickness of the first side wall 221 is H. Among them, 0.02 ≤ h 1 / H ≤ 2 / 3.

[0215] 0.02 ≤ h 1 / H ≤ 2 / 3. It can be understood that h 1 / H ≥ 0.02, so that the first avoidance groove 2241 has a certain depth, and thus there is a certain space to better avoid the edge 10a of the electrode assembly 10; h 1 / H ≤ 2 / 3, so that the groove depth of the first avoidance groove 2241 is not too large, and thus the housing 20 has better structural strength at the first arc portion 224.

[0216] By adopting the technical solution of this embodiment, the groove depth of the first avoidance groove 2241 is reasonably designed, which can take into account both the edge 10a of the electrode assembly 10 and the structural strength of the housing 20.

[0217] In some other embodiments of the present application, refer to Figure 6 and Figure 7 as shown, 0.1 ≤ h 1 / H ≤ 0.5.

[0218] By adopting the technical solution of this embodiment, the design of 0.1 ≤ h 1 / H ≤ 0.5 makes the size design of the first avoidance groove 2241 more reasonable, and can better take into account the avoidance of the edge 10a of the electrode assembly 10 and the structural strength of the housing 20.

[0219] In some embodiments, the value of h 1 / H can be 0.02, 2 / 3 or any number between 0.02 and 2 / 3. Exemplarily, the value of h 1 / H can be but is not limited to 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 2 / 3.

[0220] In some other embodiments of the present application, refer to Figure 6 and Figure 7 as shown, the groove depth of the first avoidance groove 2241 is h 1 , where 0.1 mm ≤ h 1 ≤ 0.5 mm.

[0221] 0.1 mm ≤ h 1 ≤ 0.5 mm. It can be understood that h 1 ≥ 0.1 mm makes the first avoidance groove 2241 have a certain depth, so that there is a certain space to better avoid the edge 10a of the electrode assembly 10; h 1 ≤ 0.5 mm makes the groove depth of the first avoidance groove 2241 not too large, so that the housing 20 has better structural strength at the first arc portion 224.

[0222] By adopting the technical solution of this embodiment, the groove depth of the first avoidance groove 2241 is reasonably designed, which can take into account both the edge 10a of the electrode assembly 10 and the structural strength of the housing 20.

[0223] In some other embodiments of the present application, refer to Figure 6 and Figure 7 as shown, 0.15 mm ≤ h 1 ≤ 0.35 mm.

[0224] By adopting the technical solution of this embodiment, 0.15 mm ≤ h 1 ≤ 0.35 mm, the size design of the first avoidance groove 2241 is more reasonable, which can better balance the avoidance of the edge 10a of the electrode assembly 10 and the structural strength of the housing 20.

[0225] In some embodiments, the value of h 1 can be 0.1 mm, 0.5 mm or any number between 0.1 mm and 0.5 mm. Exemplarily, the value of h 1 can be but not limited to 0.1 mm, 0.12 mm, 0.15 mm, 0.17 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm.

[0226] In other embodiments of the present application, as shown in Figures 3 - 6 , the housing 20 includes a housing body 22 and two end caps 21. The two end faces of the housing body 22 distributed relatively along the first direction are provided with openings. The electrode assembly 10 is located inside the housing body 22, and the two end caps 21 are respectively covered on the two openings; the two side walls of the housing body 22 distributed relatively along the second direction are the first side walls 221, and the two side walls of the housing body 22 distributed relatively along the third direction are the second side walls 222. A first arc portion 224 is connected between the first side wall 221 and the adjacent second side wall 222. The first direction, the second direction and the third direction are perpendicular to each other in pairs.

[0227] The first direction is perpendicular to the second direction, the second direction is perpendicular to the third direction, and the third direction is perpendicular to the first direction. The first direction can be referred to as the X direction in Figures 3 - 7 , the second direction can be referred to as the Y direction in Figures 3 - 7 , and the third direction can be referred to as the Z direction in Figures 3 - 7 . The two ends of the housing body 22 arranged relatively in the first direction are provided with openings, and the two end caps 21 are respectively covered at the two openings, so as to realize the encapsulation of the housing 20; the two side walls of the housing body 22 arranged relatively in the second direction can both be called the first side walls 221, and the two side walls of the housing body 22 arranged relatively in the third direction are called the second side walls 222. A first arc portion 224 is respectively connected between the two opposite sides of one of the first side walls 221 and the two second side walls 222, and a first arc portion 224 is respectively connected between the two opposite sides of the other first side wall 221 and the two second side walls 222, so as to enclose a space for accommodating the electrode assembly 10.

[0228] By adopting the technical solution of this embodiment, a first avoidance groove 2241 is correspondingly provided for avoidance at the edge 10a of the electrode assembly 10 extending in the first direction, and the avoidance effect of the electrode assembly 10 is good; the outer shell 20 adopts a structural form of a housing 22 and two end caps 21, with a simple structure, and the assembly and sealing of the battery cell 100 are simple.

[0229] In some other embodiments of the present application, refer to Figure 3 As shown, the electrode assembly 10 includes a plurality of electrode plates 11, and the plurality of electrode plates 11 are stacked in the third direction.

[0230] The electrode assembly 10 has a stacked structure, and the plurality of electrode plates 11 in the electrode assembly 10 are stacked in the third direction.

[0231] By adopting the technical solution of this embodiment, the plurality of electrode plates 11 are stacked in the third direction, so that the electrode assembly 10 has four edges 10a extending in the second direction, and the first avoidance grooves 2241 of the four first arc portions 224 connected between the first side wall 221 and the second side wall 222 can be disposed opposite to the four edges 10a, thereby providing an avoidance space and reducing the interference risk between the electrode assembly 10 and the outer shell 20, which is beneficial to improving the volumetric energy density and charge-discharge performance of the battery cell 100.

[0232] In some other embodiments of the present application, refer to Figure 8 、 Figure 23 and Figure 24 As shown, the outer shell 20 includes a housing 22 and an end cap 21, and the electrode assembly 10 is located inside the housing 22; one of the two end faces of the housing 22 distributed relatively in the first direction is provided with an opening, and the end cap 21 covers the opening; the side wall of the housing 22 opposite to the end cap 21 is the first side wall 221, the two side walls of the housing 22 distributed relatively in the second direction are the second side walls 222, and the two side walls of the housing 22 distributed relatively in the third direction are the third side walls 223; first arc portions 224 are connected between the two second side walls 222 on the opposite sides of the first side wall 221 respectively, and the first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0233] The first direction can refer to the X direction in Figures 8 - 24 The second direction can refer to the Y direction in Figures 8 - 24 The third direction can refer to the Figures 8 - 24In the Z direction, the housing 22 is provided with an opening, which is located on one of the two end faces of the housing 22 oppositely arranged in the first direction. The end cover 21 is covered at the opening, thereby realizing the encapsulation of the outer shell 20; both of the two side walls of the housing 22 oppositely arranged in the second direction can be referred to as the second side walls 222, and the two side walls of the housing 22 oppositely arranged in the third direction are called the third side walls 223. One pair of opposite sides of the first side wall 221 are respectively connected to the two second side walls 222, and the other pair of opposite sides of the first side wall 221 are respectively connected to the two third side walls 223, and they enclose a space for accommodating the electrode assembly 10. Among them, a first arc 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 portion; alternatively, first arc portions 224 are connected between both of the two second side walls 222 and the first side wall 221.

[0234] By adopting the technical solution of this embodiment, a first avoidance groove 2241 is correspondingly provided for avoiding the edge 10a of the electrode assembly 10 extending in the third direction, and the avoidance effect of the electrode assembly 10 is good; the outer shell 20 adopts the structural form of the housing 22 and an end cover 21, the structure is simple, and the assembly and sealing of the battery cell 100 are simple.

[0235] In some other embodiments of the present application, referring to Figure 8 、 Figure 23 and Figure 24 shown, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the first direction; alternatively, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the second direction; alternatively, the electrode assembly 10 includes a plurality of pole pieces 11, and the plurality of pole pieces 11 are stacked along the first direction.

[0236] The electrode assembly 10 is a winding structure. It can be understood that the pole pieces 11 are wound to form the electrode assembly 10. Exemplarily, the electrode assembly 10 can be in a wound flat structure. Among them, the pole pieces 11 can be wound into a cylinder and then flattened to obtain the wound flat structure of the electrode assembly 10. The electrode assembly 10 can also be obtained by other methods; of course, the electrode assembly 10 can be in a wound cylindrical structure; among them, the winding axis of the electrode assembly 10 can refer to the straight line g in Figure 15 、 Figure 17 and Figure 23 For the wound flat electrode assembly 10, the long straight line 10c of the electrode assembly 10 is likely to interfere with the housing 22.

[0237] In a possible implementation manner, referring to Figure 8As shown, the electrode assembly 10 is of a wound structure, and the winding axis of the electrode assembly 10 is parallel to the first direction. After the electrode assembly 10 is installed in the housing 22, the long straight line 10c of the electrode assembly 10 facing away from the opening of the housing 22 is likely to interfere with the housing 22. However, in this embodiment, the first avoidance groove 2241 of the first arc portion 224 is located on the side facing away from the opening of the housing 22 and is disposed opposite to the long straight line 10c of the electrode assembly 10, thereby avoiding the long straight line 10c and reducing the risk of interference between the electrode assembly 10 and the housing 22, which is beneficial to improving the volumetric 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 portions 224 can be one to avoid the long straight line 10c on one side; the number of the first arc portions 224 can be two to avoid the long straight line 10c on both sides.

[0238] In another possible embodiment, refer to Figure 24 As shown, the electrode assembly 10 is of a wound structure, and the winding axis of the electrode assembly 10 is parallel to the second direction. After the electrode assembly 10 is installed in the housing 22, the long straight line 10c of the electrode assembly 10 facing away from the opening of the housing 22 is likely to interfere with the housing 22. However, in this embodiment, the first avoidance groove 2241 of the first arc portion 224 is located on the side facing away from the opening of the housing 22 and is disposed opposite to the long straight line 10c of the electrode assembly 10, thereby avoiding the long straight line 10c and being beneficial to improving the volumetric energy density of the battery cell 100 and the charge and discharge performance of the battery cell 100.

[0239] Exemplarily, refer to Figure 24As shown, after the electrode assembly 10 is installed in the housing 22, under the action of its own gravity, the long straight line 10c on the lower side of the electrode assembly 10 is most likely to interfere with the housing 22. Therefore, a first arc portion 224 may be connected only between the lower side of the second side wall 222 and the lower side of the first side wall 221, and the first avoidance groove 2241 of the first arc portion 224 is 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 by an arc portion to reduce stress concentration; or, first arc portions 224 are connected between the upper and lower sides of the second side wall 222 and the first side wall 221, and the first avoidance grooves 2241 of the two first arc portions 224 can avoid the long straight lines 10c on the upper and lower sides of the electrode assembly 10, and the avoidance effect is better in this way. Among them, the middle of the second side wall 222 on the upper side may be recessed so that a space for accommodating the tab 12 is formed at both ends of the second side wall 222. At this time, the recessed portion of the second side wall 222 is likely to interfere with the long straight line 10c on the upper side. Therefore, a first arc portion 224 is connected between the upper side of the second side wall 222 and the upper side of the first side wall 221, and the avoidance groove 224 on the first arc portion 224 may penetrate through the portion where the first arc portion 224 is connected to the recessed portion, or may only occupy a partial area of the portion where the first arc portion 224 is connected to the recessed portion.

[0240] In another possible implementation, refer to Figure 23 As shown, the electrode assembly 10 includes a plurality of electrode plates 11, and the plurality of electrode plates 11 are stacked along a first direction. The electrode assembly 10 has a stacked structure. After the electrode assembly 10 with the plurality of electrode plates 11 stacked along the first direction is installed in the housing 22, the edge 10a of the electrode assembly 10 that faces away from the opening of the housing 22 and extends along the third direction is likely to interfere with the housing 22. However, in this implementation, the first avoidance groove 2241 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, so as to avoid 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.

[0241] By adopting the technical solution of this embodiment, the outer shell 20 can meet the avoidance requirements of the electrode assembly 10 in various structural forms, and has a wide application range.

[0242] In some other embodiments of the present application, refer to Figure 8 、 Figure 18 and Figure 19 As shown, the electrode assembly 10 has a wound structure, the winding axis of the electrode assembly 10 is parallel to the first direction, and the dimension of the electrode assembly 10 in the second direction is L 1 ,and the distance between the first avoidance groove 2241 and the adjacent third side wall 223 is L 2, where 1 / 15 ≤ L 2 / L 1 ≤ 0.5.

[0243] The distance L between the first avoidance groove 2241 and the adjacent third side wall 223 2 may refer to the distance between the inner wall surface of the third side wall 223 and the first avoidance groove 2241.

[0244] Exemplarily, referring to Figure 8 、 Figure 18 and Figure 19 shown, when the arc line 10b is a semi - circle or similar to a semi - circle, the width L of the electrode assembly 10 1 is 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 of the width of the electrode assembly 10.

[0245] 1 / 15 ≤ L 2 / L 1 ≤ 0.5. It can be understood that L 2 / L 1 ≤ 0.5, so that the length of the first avoidance groove 2241 can be greater than or equal to the length of the long straight side of the electrode assembly 10, and the length of the first avoidance groove 2241 is greater than or equal to the length of the edge 10a of the electrode assembly 10, so that the first avoidance groove 2241 can avoid the end points of the edge 10a of the electrode assembly 10, and thus the first avoidance groove 2241 can avoid the entire edge 10a of the electrode assembly 10; L 2 / L 1 ≥ 1 / 15, so that there is a certain distance between the first avoidance groove 2241 and the third side wall 223, and the first avoidance groove 2241 is not too long, which is beneficial to improving the structural strength of the first arc portion 224 and the housing 22.

[0246] Exemplarily, referring to Figure 19 shown, L 2 / L 1 ≥ 1 / 15, so that the first avoidance groove 2241 does not extend to the fourth arc portion 227, and the housing 22 has good structural strength.

[0247] By adopting the technical solution of this embodiment, the length of the first avoidance groove 2241 is reasonably designed, and the structural strength of the housing 22 and the avoidance of the edge 10a of the electrode assembly 10 can be taken into account at the same time.

[0248] In some other embodiments of the present application, referring to Figure 8 、 Figure 18 and Figure 19 shown, 0.1 ≤ L 3 / L 1 ≤ 0.4.

[0249] By adopting the technical solution of this embodiment, 0.1 ≤ L 3 / L 1 ≤ 0.4, the design of the length of the first avoidance groove 2241 is more reasonable, which can better balance the structural strength of the housing 22 and the avoidance of the edge 10a of the electrode assembly 10.

[0250] In some embodiments, the value of L 2 / L 1 can be 1 / 15, 0.5, or any value between 1 / 15 and 0.5. By way of example, the value of L 2 / L 1 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.

[0251] In some other embodiments of the present application, referring to Figure 8 , Figure 18 and Figure 19 as shown, the electrode assembly 10 is a wound structure, the winding axis of the electrode assembly 10 is parallel to the first direction, and the distance between the first avoidance groove 2241 and the adjacent third side wall 223 is L 2 , where 3 mm ≤ L 2 ≤ 8 mm.

[0252] 3 mm ≤ L 2 ≤ 8 mm. It can be understood that L 2 ≥ 3 mm, so that there is a certain distance between the first avoidance groove 2241 and the third side wall 223, and the first avoidance groove 2241 is not too long, which is beneficial to improving the structural strength of the housing 22; L 2 ≤ 8 mm, so that the first avoidance groove 2241 can avoid the end point of the edge 10a of the electrode assembly 10, and the first avoidance groove 2241 can avoid the entire edge 10a of the electrode assembly 10.

[0253] By way of example, referring to Figure 19 as shown, in some cases, the radius R 4 of the inner wall surface of the third arc portion 226 is less than or equal to 3 mm, and the design of L 2 ≥ 3 mm makes the first avoidance groove 2241 not extend to the fourth arc portion 227, and the housing 22 has better structural strength.

[0254] By adopting the technical solution of this embodiment, the length design of the first avoidance groove 2241 is reasonable, which can balance the structural strength of the housing 22 and the avoidance of the edge 10a of the electrode assembly 10 at the same time.

[0255] In some other embodiments of the present application, referring toFigure 8 , Figure 18 and Figure 19 As shown, 4mm ≤ L 2 ≤ 6mm.

[0256] By adopting the technical solution of this embodiment, the design of 4mm ≤ L 2 ≤ 6mm makes the length design of the first avoidance groove 2241 more reasonable, and can better balance the structural strength of the housing 22 and the avoidance of the edge 10a of the electrode assembly 10.

[0257] In some embodiments, the value of L 2 can be 3mm, 8mm or any value between 3mm and 8mm. By way of example, the value of L 2 can be, but is not limited to, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm.

[0258] In other embodiments of the present application, referring to Figure 8 , Figure 15 and Figure 17 as shown, the electrode assembly 10 is a wound structure, the winding axis of the electrode assembly 10 is parallel to the first direction, and second arc portions 225 are connected between two opposite side portions of the first side wall 221 and two third side walls 223 respectively. A fourth avoidance groove 2251 is provided inside the second arc portion 225 for avoiding the vertex of the end portion of the electrode assembly 10 adjacent to the second arc portion 225.

[0259] The second arc portion 225 may refer to a structure for smoothly connecting the first side wall 221 and the third side wall 223. By way of example, referring to Figure 22 as shown, the second arc portion 225 is a chamfered corner structure, and the second arc portion 225 can also be referred to as an R corner. Referring to Figure 8 as shown, the fourth avoidance groove 2251 for avoiding the vertex of the end portion of the electrode assembly 10 adjacent to the second arc portion 225 may refer to the vertex of the arc line 10b of the electrode assembly 10. The second arc portion 225 is disposed opposite to the vertex of the arc line 10b of the electrode assembly 10, and the vertex of the arc line 10b is also likely to interfere with the second arc portion 225. A fourth avoidance groove 2251 is provided inside the second arc portion 225, so that the fourth avoidance groove 2251 can avoid the vertex of the arc line 10b.

[0260] By way of example, referring to Figure 21 and Figure 22 as shown, the demarcation line between the first side wall 221 and the second arc portion 225 can be referred to as the dotted line R in the figure, and the demarcation line between the third side wall 223 and the second arc portion 225 can be referred to as the dotted line Q in the figure.

[0261] By adopting the technical solution of this embodiment, the fourth avoidance groove 2251 of the second arc portion 225 can avoid the vertex of the end portion of the electrode assembly 10. In this way, during the expansion process of the electrode assembly 10, the fourth avoidance groove 2251 can also provide an avoidance space for the vertex of the end portion of the electrode assembly 10, and can also reduce the interference amount between the electrode assembly 10 and the second arc portion 225, reducing the risks of decarburization and lithium plating caused by the interference between the electrode assembly 10 and the second arc portion 225, which is beneficial to improving the charge and discharge performance of the battery cell 100.

[0262] In some other embodiments of the present application, refer to Figure 8 、 Figure 18 and Figure 20 As shown, the electrode assembly 10 is a wound structure, and the winding axis of the electrode assembly 10 is parallel to the first direction, which is L 1 , and the distance between the fourth avoidance groove 2251 and the adjacent second side wall 222 is L 3 , where 1 / 15 ≤ L 3 / L 1 ≤ 0.5.

[0263] The distance L between the fourth avoidance groove 2251 and the adjacent second side wall 222 3 may refer to the distance between the inner wall surface of the second side wall 222 and the fourth avoidance groove 2251.

[0264] Exemplarily, refer to Figure 8 、 Figure 18 and Figure 20 As shown, in the width direction of the electrode assembly 10, the distance from the vertex of the arc line 10b to the second side wall 222 is equal to or greater than half of the width of the electrode assembly 10.

[0265] 1 / 15 ≤ L 3 / L 1 ≤ 0.5. It can be understood that L 3 / L 1 ≤ 0.5 makes the distance between the fourth avoidance groove 2251 and the second side wall 222 less than or equal to half of the width of the electrode assembly 10, and the fourth avoidance groove 2251 can avoid the vertex of the arc line 10b. The fourth avoidance groove 2251 can better avoid the end portion of the electrode assembly 10 in the length direction. In addition, when a plurality of electrode assemblies 10 are provided in the housing 22 and the plurality of electrode assemblies 10 are arranged in layers in the width direction of the electrode assembly 10, the fourth avoidance groove 2251 can also avoid the vertices of the arc lines 10b of all the electrode assemblies 10, and the avoidance effect is better; L 3 / L 1 ≥ 1 / 15 makes there be a certain distance between the fourth avoidance groove 2251 and the second side wall 222, and the fourth avoidance groove 2251 is not too long, which is beneficial to improving the structural strength of the housing 22.

[0266] Exemplarily, referring to Figure 19 shown, L 3 / L 1 ≥ 1 / 15, so that the fourth avoidance groove 2251 does not extend to the fourth arc portion 227, and the housing 22 has better structural strength.

[0267] By adopting the technical solution of this embodiment, the length of the fourth avoidance groove 2251 is reasonably designed, and the structural strength of the housing 22 and the avoidance of the electrode assembly 10 can be taken into account at the same time.

[0268] In some other embodiments of the present application, referring to Figure 8 , Figure 18 and Figure 20 shown, 0.1 ≤ L 3 / L 1 ≤ 0.4.

[0269] By adopting the technical solution of this embodiment, the design of 0.1 ≤ L 3 / L 1 ≤ 0.4 makes the length design of the fourth avoidance groove 2251 more reasonable, and the structural strength of the housing 22 and the avoidance of the electrode assembly 10 can be better taken into account.

[0270] In some embodiments, the value of L 3 / L 1 can be 1 / 15, 0.5 or any value between 1 / 15 and 0.5. Exemplarily, the value of L 3 / L 1 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.

[0271] In some other embodiments of the present application, referring to Figure 8 , Figure 18 and Figure 20 shown, the distance between the fourth avoidance groove 2251 and the adjacent second side wall 222 is L 3 , wherein, 3 mm ≤ L 3 ≤ 8 mm.

[0272] 3 mm ≤ L 3 ≤ 8 mm. It can be understood that L 3 ≥ 3 mm, so that there is a certain distance between the fourth avoidance groove 2251 and the second side wall 222, and the fourth avoidance groove 2251 is not too long, which is beneficial to improving the structural strength of the housing 22; L 3≤8 mm, so that the fourth avoidance groove 2251 can avoid the vertex of the arc line 10b of the electrode assembly 10, and the fourth avoidance groove 2251 can preferably avoid the end part of the electrode assembly 10 in the length direction.

[0273] Exemplarily, referring to Figure 19 as shown, in some cases, the radius R of the inner wall surface of the third arc part 226 4 is less than or equal to 3 mm; L 3 ≥3 mm design enables the fourth avoidance groove 2251 not to extend to the fourth arc part 227, and the housing 22 has better structural strength.

[0274] By adopting the technical solution of this embodiment, the length of the fourth avoidance groove 2251 is reasonably designed, and the structural strength of the housing 22 and the avoidance of the electrode assembly 10 can be taken into account at the same time.

[0275] In some other embodiments of the present application, referring to Figure 8 , Figure 18 and Figure 20 as shown, 4 mm ≤ L 3 ≤ 6 mm.

[0276] By adopting the technical solution of this embodiment, the 4 mm ≤ L 3 ≤ 6 mm design makes the length of the fourth avoidance groove 2251 more reasonable, and the structural strength of the housing 22 and the avoidance of the electrode assembly 10 can be better taken into account.

[0277] In some embodiments, the value of L 3 can be 3 mm, 8 mm or any value between 3 mm and 8 mm. Exemplarily, the value of L 3 can be but not limited to 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm.

[0278] In some other embodiments of the present application, referring to Figure 21 and Figure 22 as shown, the groove depth of the fourth avoidance groove 2251 is h 2 , where 0.1 mm ≤ h 2 ≤ 0.3 mm.

[0279] 0.1 mm ≤ h 2 ≤ 0.3 mm. It can be understood that h 2 ≥ 0.1 mm enables the fourth avoidance groove 2251 to have a certain depth, so that there is a certain space to preferably avoid the side of the electrode assembly 10; h 2≤0.3 mm, so that the depth of the fourth avoidance groove 2251 is not too large, so that the housing 20 has better structural strength at the second arc portion 225.

[0280] By adopting the technical solution of this embodiment, the depth of the fourth avoidance groove 2251 is reasonably designed, and it can take into account both avoiding the edge 10a of the electrode assembly 10 and the structural strength of the housing 20.

[0281] In some embodiments, the value of h 2 can be 0.1 mm, 0.3 mm or any number between 0.1 mm and 0.3 mm. Exemplarily, the value of h 2 can be but not limited to 0.1 mm, 0.12 mm, 0.15 mm, 0.17 mm, 0.2 mm, 0.25 mm, 0.3 mm.

[0282] In some embodiments, the housing 22 is usually made by stamping or bending a plate member, etc. The thickness of the plate member is equal to or not much different from the wall thickness of the side wall of the housing 22 and the wall thickness of the arc portion. The range of the wall thickness H of the first side wall 221 can be 0.2 mm to 1.5 mm, and the thickness of the plate member is also equal to or not much different from the wall thickness of the first side wall 221; the design of the above wall thickness makes the plate have a certain thickness and can be formed smoothly; in addition, the wall thickness is not too large to cause problems such as the housing 22 being too large in volume and too heavy in mass and difficult to form; for example: the value of the wall thickness H of the first side wall 221 can be but not limited to 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0283] In other embodiments of the present application, referring to Figure 15 and Figure 17 as shown, a third arc portion 226 is connected between the adjacent third side wall 223 and the second side wall 222. The third arc portion 226 is connected to the first side wall 221 with a fourth arc portion 227. One end of the fourth arc portion 227 is connected to the first arc portion 224, and the other end of the fourth arc portion 227 is connected to the second arc portion 225. A communication groove 2271 is provided inside the fourth arc portion 227, and the communication groove 2271 communicates the first avoidance groove 2241 and the fourth avoidance groove 2251.

[0284] The third arc portion 226 can refer to a structure for smoothly connecting the second side wall 222 and the third side wall 223; Exemplarily, referring to Figure 15 as shown, the third arc portion 226 is a fillet structure, and the third arc portion 226 can also be called an R corner.

[0285] A fourth arc portion 227 is connected between the third arc portion 226 and the first side wall 221. The fourth arc portion 227 can refer to a structure for smoothly connecting the first side wall 221 and the third arc portion 226. Exemplarily, referring toFigure 16 As shown, the fourth arc portion 227 is a fillet structure, and the fourth arc portion 227 can also be referred to as the corner of the housing 22.

[0286] A communication groove 2271 is formed on the inner side of the fourth arc portion 227. The communication groove 2271 can communicate with the first avoidance groove 2241 and the fourth avoidance groove 2251, so that the bottom of the housing 22 has a whole-circle groove structure.

[0287] By adopting the technical solution of this embodiment, the third arc portion 226 can be smoothly connected to the second side wall 222 and the third side wall 223, and the fourth arc portion 227 can be smoothly connected to the third arc portion 226 and the first side wall 221, which can reduce stress concentration and facilitate the molding of the housing 22; the setting of the fourth avoidance groove 2251 enables the housing 22 to have a whole-circle groove structure, which can reduce the thickness of the fourth arc portion 227, facilitate the molding of the housing 22, and the processing of the groove structure is also simpler.

[0288] In some embodiments, referring to Figure 12 and Figure 22 as shown, the groove wall surface of the third avoidance groove 2221 may also include an arc surface with a radius of R 2 ; the groove wall surface of the communication groove 2271 may also include an arc surface with a radius of R 3 , such a design enables the inner wall surface between the first side wall 221 and the third side wall 223 and the inner wall surface between the first side wall 221 and the third arc portion 226 to be smoothly connected, reducing stress concentration and being beneficial to improving the structural strength of the housing 22; in addition, the value of R 1 , the value of R 2 and the value of R 3 may be the same or different.

[0289] In other embodiments of the present application, referring to Figure 12 as shown, the groove depth of the first avoidance groove 2241 is h 1 , and the groove depth of the communication groove 2271 is h 3 , where 0.2 ≤ h 3 / h 1 ≤ 1.

[0290] 0.2 ≤ h 3 / h 1 ≤ 1. It can be understood that h 3 / h 1 ≥ 0.2, so that the fourth arc portion 227 has a communication groove 2271 with a certain depth. The communication groove 2271 can reduce the stress concentration of the fourth arc portion 227, improve the structural strength, and can also reduce the tensile cracking of the housing 22 and facilitate the molding of the housing 22; h 3 / h 1≤1, the groove depth of the communication groove 2271 is less than or equal to the groove depth of the first relief groove 2241, so that the thickness of the fourth arc portion 227 is relatively large, so that the housing 22 has good structural strength at the corner, which is beneficial to improving the structural strength of the housing 22.

[0291] By adopting the technical solution of this embodiment, the groove depth of the communication groove 2271 is reasonably designed, so that the housing 22 is convenient to form and the housing 22 has good structural strength at the corner, which is beneficial to improving the structural strength of the housing 22.

[0292] In some other embodiments of the present application, refer to Figure 12 as shown, 0.3 ≤ h 3 / h 1 ≤ 0.7.

[0293] By adopting the technical solution of this embodiment, the design of 0.3 ≤ h 3 / h 1 ≤ 0.7 makes the groove depth of the communication groove 2271 more reasonable, so that the housing 22 is more convenient to form and the housing 22 has better structural strength at the corner, which is beneficial to improving the structural strength of the housing 22.

[0294] In some embodiments, the value of h 3 / h 1 can be 0.2, 1 or any number between 0.2 and 1. Exemplarily, the value of h 3 can be but not limited to 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.

[0295] In some other embodiments of the present application, refer to Figure 12 as shown, the groove depth of the communication groove 2271 is h 3 , where 0.1 mm ≤ h 3 ≤ 0.3 mm.

[0296] 0.1 mm ≤ h 3 ≤ 0.3 mm. It can be understood that h 3 ≥ 0.1 mm, so that the communication groove 2271 with a certain depth is formed in the fourth arc portion 227. The communication groove 2271 can reduce the stress concentration of the fourth arc portion 227, improve the structural strength, and also reduce the tensile cracking of the housing 22. h 3 ≤ 0.3 mm, so that the groove depth of the communication groove 2271 is not too large, so that the outer shell 20 has better structural strength at the fourth arc portion 227.

[0297] By adopting the technical solution of this embodiment, the groove depth of the communication groove 2271 is reasonably designed, which can take into account both the molding of the housing 20 and the structural strength at the same time.

[0298] In some embodiments, the value of h 3 can be 0.1 mm, 0.3 mm or any number between 0.1 mm and 0.3 mm. By way of example, the value of h 3 can be, but is not limited to, 0.1 mm, 0.12 mm, 0.15 mm, 0.17 mm, 0.2 mm, 0.25 mm, 0.3 mm.

[0299] The battery cell 100 of the present application will be described below in conjunction with some specific embodiments.

[0300] Embodiment 1

[0301] In this embodiment, as shown in Figures 3 - 6 , the battery cell 100 includes an electrode assembly 10 and a housing 20. The electrode assembly 10 is located inside the housing 20. The housing 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 disposed opposite to the edge 10a of the electrode assembly 10, and at least a part of the first arc portion 224 is provided with a first avoidance groove 2241 for avoiding the corresponding edge 10a of the electrode assembly 10.

[0302] In this embodiment, the housing 20 includes a housing body 22 and two end caps 21. The housing body 22 is provided with openings at both end faces distributed along the first direction. The electrode assembly 10 is located inside the housing body 22, and the two end caps 21 are respectively covered on the two openings; the two side walls of the housing body 22 distributed along the second direction are the first side walls 221, and the two side walls of the housing body 22 distributed along the third direction are the second side walls 222. A first arc portion 224 is connected between the first side wall 221 and the adjacent second side wall 222. The first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0303] In this embodiment, the electrode assembly 10 includes a plurality of electrode plates 11, and the plurality of electrode plates 11 are stacked along the third direction.

[0304] In this embodiment, the side edge of the first side wall 221 close to the first arc portion 224 is provided with a second avoidance groove 2211. The first avoidance groove 2241 and the second avoidance groove 2211 are communicated with each other to jointly form an avoidance groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10.

[0305] In this embodiment, the groove wall surface of the avoidance groove 228 includes an arc surface 2281. The arc surface 2281 is provided on the first arc portion 224, and the arc surface 2281 is connected between the inner wall surfaces of the first side wall 221 and the second side wall 222.

[0306] In this embodiment, the groove wall surface of the avoidance groove 228 further includes a first connection surface 2282. The first connection surface 2282 is provided on the first side wall 221. The first connection surface 2282 is connected between the arc surface 2281 and the inner wall surface of the first side wall 221, and the first connection surface 2282 is inclined with respect to the inner wall surface of the first side wall 221.

[0307] In this embodiment, the groove wall surface of the avoidance groove 228 further includes a first plane 2283. The first plane 2283 is provided on the first side wall 221. The first plane 2283 is connected between the first connection surface 2282 and the arc surface 2281, and the first plane 2283 is parallel to the inner wall surface of the first side wall 221.

[0308] In this embodiment, the other side of the arc surface 2281 is tangent to the inner wall surface of the second side wall 222.

[0309] Embodiment Two

[0310] The difference between this embodiment and Embodiment One is as follows: Refer to Figure 7 As shown, a second avoidance groove 2211 is provided at the edge of the first side wall 221 close to the first arc portion 224, and a third avoidance groove 2221 is provided at the edge of the second side wall 222 close to the first arc portion 224. The first avoidance groove 2241, the second avoidance groove 2211, and the third avoidance groove 2221 are communicated and jointly enclose an avoidance groove 228 for avoiding the corresponding edge 10a of the electrode assembly 10.

[0311] In this embodiment, the groove wall surface of the avoidance groove 228 further includes a second connection surface 2284. The second connection surface 2284 is provided on the second side wall 222. The second connection surface 2284 is connected between the arc surface 2281 and the second side wall 222, and the second connection surface 2284 is inclined with respect to the inner wall surface of the second side wall 222.

[0312] In this embodiment, the groove wall surface of the avoidance groove 228 further includes a second plane 2285. The second plane 2285 is provided on the second side wall 222. The second plane 2285 is connected between the second connection surface 2284 and the arc surface 2281, and the second plane 2285 is parallel to the inner wall surface of the second side wall 222.

[0313] Embodiment Three

[0314] The difference between this embodiment and Embodiment One is as follows: Refer to Figures 8 - 11As shown, the outer shell 20 includes a housing 22 and an end cap 21. The electrode assembly 10 is located inside the housing 22. One of the two end faces of the housing 22 distributed relatively along the first direction is provided with an opening, and the end cap 21 covers the opening. The side wall of the housing 22 opposite to the end cap 21 is the first side wall 221. The two side walls of the housing 22 distributed relatively along the second direction are the second side walls 222. The two side walls of the housing 22 distributed relatively along the third direction are the third side walls 223. First arc-shaped portions 224 are connected between the two second side walls 222 and the two opposite sides of the first side wall 221 respectively. The first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0315] In this embodiment, the electrode assembly 10 is a winding structure, and the winding axis of the electrode assembly 10 is parallel to the first direction.

[0316] In this embodiment, the groove wall surface of the avoidance groove 228 further includes a first connection surface 2282. The first connection surface 2282 is provided on the first side wall 221. The first connection surface 2282 is connected between the arc surface 2281 and the inner wall surface of the first side wall 221, and the first connection surface 2282 is perpendicular to the inner wall surface of the first side wall 221.

[0317] Embodiment Four

[0318] The difference between this embodiment and Embodiment Three is as follows: Refer to Figure 13 As shown, the groove wall surface of the avoidance groove 228 further includes a first connection surface 2282. The first connection surface 2282 is provided on the first side wall 221. One side of the first connection surface 2282 is connected to one side of the arc surface 2281, and the other side of the first connection surface 2282 is connected to the inner wall surface of the first side wall 221. The first connection surface 2282 is inclined with respect to the inner wall surface of the first side wall 221.

[0319] Embodiment Five

[0320] The difference between this embodiment and Embodiment Three is as follows: Refer to Figure 14 As shown, the groove wall surface of the avoidance groove 228 includes a third plane 2286, a fourth plane 2287, and a third connection surface 2288 that are connected in sequence. The third plane 2286 is coplanar with the inner wall surface of the second side wall 222. The third plane 2286 is perpendicular to the fourth plane 2287. The third connection surface 2288 is connected between the fourth plane 2287 and the inner wall surface of the first side wall 221.

[0321] Embodiment Six

[0322] The difference between this embodiment and Embodiment Three is as follows: Refer to Figure 12 、 Figure 15 、 Figure 16 、 Figure 18 and Figure 19As shown, second arc portions 225 are connected between opposite side portions of the first side wall 221 and two third side walls 223 respectively.

[0323] In this embodiment, a third arc portion 226 is connected between adjacent third side walls 223 and second side wall 222. The third arc portion 226 is connected to the first side wall 221 by a fourth arc portion 227. One end of the fourth arc portion 227 is connected to the first arc portion 224, and the other end of the fourth arc portion 227 is connected to the second arc portion 225.

[0324] Embodiment Seven

[0325] The difference between this embodiment and Embodiment Six is as follows: Referring to Figure 15 、 Figure 17 、 Figure 18 and Figures 20 - 22 As shown, a fourth avoidance groove 2251 is provided inside the second arc portion 225. The fourth avoidance groove 2251 is used to avoid the vertex of the end portion of the electrode assembly 10 adjacent to the second arc portion 225.

[0326] In this embodiment, a communication groove 2271 is provided inside the fourth arc portion 227. The communication groove 2271 communicates the first avoidance groove 2241 and the fourth avoidance groove 2251.

[0327] Embodiment Eight

[0328] The difference between this embodiment and Embodiment Three is as follows: Referring to FIG. 23, the electrode assembly 10 includes a plurality of electrode plates 11, and the plurality of electrode plates 11 are stacked along the first direction.

[0329] Embodiment Nine

[0330] The difference between this embodiment and Embodiment Three is as follows: Referring to FIG. 24, the electrode assembly 10 is a wound structure, and the winding axis of the electrode assembly 10 is parallel to the second direction.

[0331] In some other embodiments of the present application, a battery 1100 is provided, including the battery cell 100 as described in the above embodiments.

[0332] The battery 1100 of the embodiment of the present application adopts the above battery cell 100. The battery 1100 has a large volumetric energy density, good use reliability, a long battery life, and good use reliability.

[0333] In some other embodiments of the present application, an electrical device is provided, including the battery 1100 as described in the above embodiments.

[0334] The electrical device according to the embodiment of the present application uses the above-mentioned battery 1100. The battery 1100 has a large volumetric energy density and good usage reliability, so that the electrical device has a long battery life and better performance.

[0335] The descriptions of the above embodiments tend to emphasize the differences between the embodiments. For their similarities, reference can be made to each other. For the sake of brevity, they will not be elaborated herein.

[0336] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling 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. The first arc portion is arranged opposite to the edge of the electrode assembly. At least part of the first arc portion is provided with a first avoidance groove for avoiding the edge corresponding to the electrode assembly.

2. The battery cell according to claim 1, characterized in that: A second avoidance groove is provided on the edge of the first side wall close to the first arc-shaped portion, and the first avoidance groove is connected to the second avoidance groove and together forms a avoidance groove for avoiding the corresponding edge of the electrode assembly.

3. The battery cell according to claim 1, characterized in that: A third avoidance groove is provided on the edge of the second side wall close to the first arc-shaped portion, and the first avoidance groove and the third avoidance groove are connected and jointly formed to form a avoidance groove for avoiding the corresponding edge of the electrode assembly.

4. The battery cell according to claim 1, characterized in that: A second avoidance groove is provided on the edge of the first side wall near the first arc-shaped portion, and a third avoidance groove is provided on the edge of the second side wall near the first arc-shaped portion. The first avoidance groove, the second avoidance groove and the third avoidance groove are connected and jointly formed to form a avoidance groove for avoiding the corresponding edges of the electrode assembly.

5. The battery cell according to claim 2 or 4, characterized in that: The groove wall surface of the avoidance groove includes an arc surface, the arc surface is arranged on the first arc-shaped portion, and the arc surface is connected between the inner wall surface of the first side wall and the inner wall surface of the second side wall.

6. The battery cell according to claim 5, characterized in that: The groove wall surface of the avoidance groove also includes a first connecting surface, which is arranged on the first side wall, the first connecting surface is connected between the arc surface and the inner wall surface of the first side wall, and the first connecting surface is inclined or perpendicular to the inner wall surface of the first side wall.

7. The battery cell according to claim 6, characterized in that: The groove wall surface of the avoidance groove also includes a first plane, which is arranged on the first side wall; the first plane is connected between the first connecting surface and the arc surface, and the first plane is parallel to the inner wall surface of the first side wall.

8. The battery cell according to claim 5, characterized in that: The other side of the arc surface is tangent to the inner wall surface of the second side wall.

9. The battery cell according to claim 5, characterized in that: A third avoidance groove is provided on the edge of the second side wall near the first arc-shaped portion, and the first avoidance groove, the second avoidance groove and the third avoidance groove are connected and jointly formed to form a avoidance groove for avoiding the corresponding edge of the electrode assembly; the groove wall surface of the avoidance groove also includes a second connecting surface, and the second connecting surface is provided on the second side wall, and the second connecting surface is connected between the arc surface and the second side wall, and the second connecting surface is inclined or perpendicular to the inner wall surface of the second side wall.

10. The battery cell according to claim 9, characterized in that: The groove wall surface of the avoidance groove also includes a second plane, the second plane is arranged on the second side wall, the second plane is connected between the second connecting surface and the arc surface, and the second plane is parallel to the inner wall surface of the second side wall.

11. The battery cell according to claim 5, characterized in that: The radius of the arc surface is R1, and the dimension of the avoidance groove in a direction perpendicular to the inner wall surface of the second side wall is W, wherein 1≤W / R1≤3.

12. The battery cell according to claim 11, characterized in that: 1.5≤W / R1≤2.

5.

13. The battery cell according to claim 2, characterized in that: The groove wall surface of the avoidance groove includes a third plane, a fourth plane and a third connecting surface connected in sequence, the third plane is coplanar with the inner wall surface of the second side wall, the third plane is perpendicular to the fourth plane, and the third connecting surface is connected between the fourth plane and the inner wall surface of the first side wall.

14. The battery cell according to any one of claims 1 to 4, characterized in that: The groove depth of the first avoidance groove is h1, and the wall thickness of the first side wall is H, wherein 0.02≤h1 / H≤2 / 3.

15. The battery cell according to claim 14, characterized in that: 0.1≤h1 / H≤0.

5.

16. The battery cell according to claim 14, characterized in that: The groove depth of the first avoidance groove is h1, wherein 0.1 mm≤h1≤0.5 mm.

17. The battery cell according to claim 16, characterized in that: 0.15mm≤h1≤0.35mm.

18. The battery cell according to any one of claims 1 to 4, 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.

19. The battery cell according to claim 18, characterized in that: The electrode assembly includes a plurality of pole pieces, and the plurality of pole pieces are stacked along the third direction.

20. The battery cell according to any one of claims 1 to 4, 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 portions are connected between the two opposite side portions of the first side wall and the two second side walls respectively, and the first direction, the second direction and the third direction are perpendicular to each other.

21. The battery cell according to claim 20, 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.

22. The battery cell according to claim 20, 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 L1, and the spacing between the first avoidance groove and the adjacent third side wall is L2, wherein 1 / 15≤L2 / L1≤0.

5.

23. The battery cell according to claim 22, characterized in that: 0.1≤L2 / L1≤0.

4.

24. The battery cell according to claim 20, 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 first avoidance groove and the adjacent third side wall is L2, wherein 3mm≤L2≤8mm.

25. The battery cell according to claim 24, characterized in that: 4mm≤L2≤6mm.

26. The battery cell according to claim 20, characterized in that: The electrode assembly is a winding structure, the winding axis of the electrode assembly is parallel to the first direction, a second arc portion is connected between the two opposite sides of the first side wall and the two third side walls respectively, and a fourth avoidance groove is provided on the inner side of the second arc portion, and the fourth avoidance groove is used to avoid the vertex of the end of the electrode assembly adjacent to the second arc portion.

27. The battery cell according to claim 26, characterized in that: The dimension of the electrode assembly in the second direction is L1, and the distance between the fourth avoidance groove and the adjacent second side wall is L3, wherein 1 / 15≤L3 / L1≤0.

5.

28. The battery cell according to claim 27, characterized in that: 0.1≤L3 / L1≤0.

4.

29. The battery cell according to claim 26, characterized in that: The distance between the fourth avoidance groove and the adjacent second side wall is L3, wherein 3mm≤L3≤8mm.

30. The battery cell according to claim 28, characterized in that: 4mm≤L3≤6mm.

31. The battery cell according to claim 26, characterized in that: The groove depth of the fourth avoidance groove is h2, wherein 0.1 mm≤h2≤0.3 mm.

32. The battery cell according to claim 26, characterized in that: A third arc portion is connected between the adjacent third side wall and the second side wall, a fourth arc portion is connected between the third arc portion and the first side wall, one end of the fourth arc portion is connected to the first arc portion, and the other end of the fourth arc portion is connected to the second arc portion, and a connecting groove is provided on the inner side of the fourth arc portion, and the connecting groove connects the first avoidance groove and the fourth avoidance groove.

33. The battery cell according to claim 32, characterized in that: The groove depth of the first avoidance groove is h1, and the groove depth of the connecting groove is h3, wherein 0.2≤h3 / h1≤1.

34. The battery cell according to claim 33, characterized in that: 0.3≤h3 / h1≤0.

7.

35. The battery cell according to claim 32, characterized in that: The depth of the connecting groove is h3, wherein 0.1 mm≤h3≤0.3 mm.

36. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 35.

37. An electrical device, characterized in that: Comprising the battery of claim 36.

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