Housing, battery cell, battery, and electrical device

Abstract

The present invention provides a housing, a battery cell, a battery, and an electrical device. An end portion of the housing along a first direction is provided with a housing opening, the housing comprises a first side plate and a second side plate arranged along the circumferential direction of the housing opening, a connecting plate is connected to the first side plate and the second side plate, at least part of an outer surface of the connecting plate comprises a curved face, the connecting plate comprises a first plate portion and a second plate portion, and on the first direction, the second plate portion is located on the side of the first plate portion close to the housing opening. The maximum thickness of the second plate portion is greater than or equal to the maximum thickness of the first plate portion. The embodiments of the present application can reduce the risk of cracking and damage at a welding position between the second plate portion and an end cover caused by housing deformation or battery cell vibration due to factors such as expansion stress of an electrode assembly, and improve the usage reliability of the battery cell.

Description

Housing, battery cell, battery and electrical device Technical Field

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

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0003] However, during use, the shell of the battery cell is prone to cracking, affecting the reliability of the battery cell.

[0004] Summary of the Invention

[0005] In view of the above problems, the present application provides a housing, a battery cell, a battery and an electrical device, which can improve the reliability of the battery cell.

[0006] In one aspect, embodiments of the present application provide a battery cell housing, wherein the housing has a housing opening at an end along a first direction, the housing includes a first side plate and a second side plate arranged circumferentially along the housing opening, a connecting plate connected to the first and second side plates, and at least a portion of the outer surface of the connecting plate comprises a curved surface, the connecting plate includes a first plate portion and a second plate portion, and the second plate portion is located on a side of the first plate portion closer to the housing opening in the first direction. The maximum thickness of the second plate portion is greater than or equal to the maximum thickness of the first plate portion.

[0007] In the above solution, the second plate portion is positioned closer to the housing opening than the first plate portion. During the process of mating and connecting the housing and the end cap, the second plate portion of the connecting plate is welded to the end cap. Based on this, in this embodiment of the application, the maximum thickness of the second plate portion is set to be no less than the maximum thickness of the first plate portion. This reduces the risk of cracking and damage at the weld point between the second plate portion and the end cap due to housing deformation caused by factors such as expansion stress of the electrode assembly or battery cell vibration, thereby improving the reliability of the battery cells.

[0008] In some embodiments, the first side plate includes a third plate portion and a fourth plate portion, wherein in the first direction, the fourth plate portion is located on a side of the third plate portion close to the housing opening, wherein the maximum thickness of the fourth plate portion is greater than the maximum thickness of the third plate portion.

[0009] In the above solution, the maximum thickness of the fourth plate portion is set to be greater than the maximum thickness of the third plate portion, so that the fourth plate portion can have greater structural strength than the third plate portion, thereby reducing the risk of cracking and damage at the welding position between the fourth plate portion and the end cover due to the expansion stress of the electrode assembly, thereby improving the reliability of the battery cell.

[0010] In some embodiments, the inner surface of the third plate portion is concave relative to the inner surface of the fourth plate portion; and / or the inner surface of the first plate portion is concave relative to the inner surface of the second plate portion.

[0011] In the above solution, a relief space is formed by recessing at least one of the third plate portion and the first plate portion. The relief space can accommodate part of the structure of the battery cell, thereby maximizing the distance between the third plate portion or the first plate portion and the electrode assembly without reducing the size of the electrode assembly. Furthermore, when the electrode assembly expands, the relief space can accommodate a certain amount of expansion of the electrode assembly, thereby reducing the deformation of the third plate portion or the first plate portion caused by the expansion of the electrode assembly, reducing the risk of cracks in the housing, and improving the reliability of the housing and the corresponding battery cell.

[0012] In some embodiments, the outer surface of the third plate portion is flush with the outer surface of the fourth plate portion; and / or the outer surface of the first plate portion is flush with the outer surface of the second plate portion.

[0013] In the above solution, by arranging the outer surface of the third plate portion flush with the outer surface of the fourth plate portion, the flatness of the outer surface of the first side plate can be improved, reducing the risk of damage caused by collisions with other components due to protruding structures on the outer surface of the first side plate, thereby improving the reliability of the first side plate. Similarly, by arranging the outer surface of the first plate portion flush with the outer surface of the second plate portion, the flatness of the outer surface of the connecting plate can be improved, reducing the risk of damage caused by collisions with other components due to protruding structures on the outer surface of the connecting plate, thereby improving the reliability of the connecting plate.

[0014] In some embodiments, the maximum thickness of the third plate portion is H1, the maximum thickness of the fourth plate portion is H2, and H1 and H2 satisfy: 0.05 mm ≤ H2 - H1 ≤ 0.3 mm.

[0015] In the above solution, the thickness difference between the first plate portion and the second plate portion is set to be no less than 0.05 mm, so as to ensure that at least part of the structure within the battery cell can be accommodated in the avoidance space, thereby reducing the deformation of the first plate portion while improving the internal space utilization of the battery cell and increasing the energy density of the battery cell.

[0016] In some embodiments, the first side plate further includes a first transition portion, the first transition portion being located between the first plate portion and the second plate portion, wherein a thickness of the first transition portion gradually increases in a direction from the first plate portion to the second plate portion.

[0017] In the above scheme, the first transition portion is located between the first plate portion and the second plate portion. Since the inner surface of the first plate portion is concave relative to the inner surface of the second plate portion, the embodiment of the present application gradually increases the thickness of the first transition portion in the direction from one plate portion to the second plate portion, so as to achieve a smooth transition between the first plate portion and the second plate portion with the help of the first transition portion, reduce the difficulty of forming the shell, reduce stress concentration, and reduce the risk of cracking of the first side panel.

[0018] In some embodiments, the first transition portion includes a first transition surface facing the interior of the shell, and an angle α between the first transition surface and the first direction satisfies: 2°≤α≤60°.

[0019] In the above solution, the angle α between the first transition surface and the first direction is set to no greater than 60°, thereby reducing the risk of puncturing the electrode assembly and the first insulating member, thereby improving the reliability of the battery cell. This design also helps to reduce the difficulty of mold removal during casing production, thereby improving the casing production yield rate.

[0020] In some embodiments, 2°≤α≤40°.

[0021] In the above solution, by setting the angle α between the first transition surface and the first direction to no greater than 40°, the risk of puncturing the electrode assembly and the first insulating member is further reduced, thereby improving the reliability of the battery cell. This also helps to further reduce the difficulty of mold removal during casing production, thereby improving the casing production yield.

[0022] In some embodiments, the maximum thickness of the second plate portion is H3, the maximum thickness of the fourth plate portion 112 is H2, and H2 and H3 satisfy: 0.1 mm≤H3≤0.8H2.

[0023] In the above solution, the maximum thickness H3 of the second plate portion is set to no less than 0.1 mm, thereby ensuring that the second plate portion has a certain thickness dimension and improving its reliability. Furthermore, the maximum thickness H3 of the second plate portion is set to no more than 0.8H2, thereby reducing the risk of stress concentration at the connecting plate during the shell manufacturing process and the probability of cracking at the connecting plate.

[0024] In some embodiments, the maximum thickness of the second plate portion is not greater than the maximum thickness of the fourth plate portion; and / or the difference between the maximum thicknesses corresponding to the second plate portion and the first plate portion is not greater than the difference between the maximum thicknesses corresponding to the fourth plate portion and the third plate portion.

[0025] In the above scheme, the maximum thickness of the second plate portion is set not greater than the maximum thickness of the fourth plate portion, so that the thickness of the second plate portion is relatively small, thereby reducing the difficulty of demolding the shell at the connecting plate position, and reducing the risk of the connecting plate turning over and cracking, thereby improving the production yield of the shell.

[0026] In some embodiments, the two second side panels are disposed opposite each other in the second direction, and the first direction intersects the second direction. The fourth panel portion includes a central portion and an edge portion located on at least one side of the central portion along the second direction, the edge portion being connected to the second panel portion, and the maximum thickness of the edge portion being less than the maximum thickness of the central portion.

[0027] In the above solution, the maximum thickness of the edge portion of the fourth plate portion is smaller than the maximum thickness of the center portion. The existence of the edge portion makes the fourth plate portion partially unthickened or the locally thickened size is small, which helps to reduce the demolding difficulty corresponding to the fourth plate portion and improve the production yield of the shell.

[0028] In some embodiments, a dimension of the central portion in the second direction is Z1, a dimension of the housing in the second direction is Z2, and Z1 and Z2 satisfy: 0.5≤Z1 / Z2.

[0029] In the above solution, the size of the central portion in the second direction is limited so that the size Z1 of the central portion in the second direction is not less than half the size of the shell in the second direction. This improves the structural reliability of the fourth plate portion and reduces the risk of cracking and damage in the fourth plate portion.

[0030] In some embodiments, an included angle between an inner surface of the fourth plate portion and an inner surface of the second plate portion is β, and β satisfies: 155°≤β≤270°.

[0031] In the above solution, setting β to no less than 155° helps reduce the thickness of the fourth plate portion, thereby improving demolding difficulty and reducing the risk of cracking. Furthermore, setting β to no more than 270° reduces the difficulty of shell assembly, improves shell molding efficiency, and also helps strengthen the weld seam formed by welding.

[0032] In some embodiments, the second plate portion includes a plate body and a second transition portion connecting the plate body and the fourth plate portion, wherein the maximum thickness of the plate body is less than the maximum thickness of the second transition portion. The thickness of the second transition portion gradually increases in a direction approaching the fourth plate portion.

[0033] In the above solution, the fourth plate portion is provided with a second transition portion and a plate body, and the second transition portion enables connection between the plate body and the second plate portion. Furthermore, to reduce the occurrence of sudden changes in thickness at certain locations within the housing, the embodiment of the present application also provides a gradually decreasing thickness of the second transition portion along the direction from the second plate portion toward the plate body. This achieves a reliable transition between the second plate portion and the plate body, improves reliability at the interface between the second plate portion and the fourth plate portion, and reduces the difficulty of housing fabrication.

[0034] In some embodiments, the two second side plates are arranged opposite to each other in the second direction, and the first direction intersects the second direction. A dimension of the second transition portion in the second direction is L1, and L1 satisfies: 1mm≤L1≤15mm.

[0035] In the above solution, the dimension L1 of the second transition portion is set to no less than 1 mm, thereby reducing the difficulty of demolding the housing and improving the efficiency of housing production. Furthermore, the dimension L1 of the second transition portion is set to no more than 15 mm, thereby increasing the weld strength between the housing and the end cap, and improving the reliability of the subsequently formed battery cell.

[0036] In some embodiments, the inner surface of the second transition portion includes a curved surface structure; and / or, the inner surface of the second transition portion includes a planar structure.

[0037] In the above scheme, the second transition portion is used to connect the second plate portion and the plate main body. On this basis, in order to improve the structural reliability of the shell, the embodiment of the present application sets the inner surface of the second transition portion to include at least one of a curved surface structure and a plane structure. With the help of the curved surface structure, a smooth transition between the fourth plate portion and the plate main body can be achieved, and with the help of the plane structure, a smooth transition between the fourth plate portion and the plate main body can be achieved. This can improve the structural reliability of the shell at the junction of the second plate portion and the fourth plate portion, and at the same time, it can also improve the stress concentration at the connecting plate position and reduce the risk of cracking of the connecting plate.

[0038] In some embodiments, the maximum thickness of the second plate portion is greater than the maximum thickness of the first plate portion, and the connecting plate further includes a fifth transition portion located between the first plate portion and the second plate portion. The thickness of the fifth transition portion gradually increases in the first direction from the first plate portion toward the second plate portion 132.

[0039] In the above scheme, the fifth transition portion is located between the first plate portion and the second plate portion. Since the maximum thickness of the second plate portion is greater than or equal to the maximum thickness of the first plate portion, the embodiment of the present application gradually increases the thickness of the fifth transition portion in the direction from the first plate portion to the second plate portion, so as to achieve a smooth transition between the first plate portion and the second plate portion with the help of the fifth transition portion, reduce the difficulty of forming the shell, reduce stress concentration, and reduce the risk of cracking of the first side panel.

[0040] In some embodiments, the sixth plate portion is provided with a first recessed portion formed inwardly from the shell opening, and the first recessed portion is used to receive the end cover.

[0041] In the above solution, by providing a first recess at the sixth plate portion, the end cover can be partially located in the first recess, thereby enabling the relative position of the end cover to be determined with the help of the first recess, thereby improving the reliability of the relative position between the end cover and the shell.

[0042] In some embodiments, a thickness dimension of the sixth plate portion at the first recess is not less than a maximum thickness of the fifth plate portion.

[0043] In the above solution, the structural strength of the sixth plate portion can be further improved, thereby reducing the risk of cracking at the sixth plate portion and improving the reliability of the battery cell.

[0044] In some embodiments, the first side plate includes a third plate portion and a fourth plate portion, wherein the fourth plate portion is located on a side of the third plate portion close to the housing opening in the first direction, and wherein the size of the sixth plate portion is greater than or equal to the size of the fourth plate portion in the first direction.

[0045] In the above scheme, by setting the size of the sixth plate portion in the first direction to be greater than or equal to the size of the fourth plate portion in the first direction, the structural strength difference between the sixth plate portion and the fourth plate portion caused by the existence of the first recess can be reduced, thereby further reducing the risk of cracking of the sixth plate portion and improving overall reliability.

[0046] In some embodiments, the second plate portion is provided with a second recessed portion formed inwardly from the shell opening, and the first recessed portion is communicated with the second recessed portion.

[0047] In the above solution, a second recess is added to the first recess. Both the first and second recesses are used to receive the end cap, thereby improving the reliability of the relative position of the end cap relative to the second side plate and the connecting plate, thereby helping to improve the reliability of the connection between the end cap and the housing. Furthermore, in this embodiment of the application, the first and second recesses are connected. This helps reduce the risk of a sudden change in the thickness of the housing at the junction of the first and second recesses, reduces the difficulty of manufacturing the housing, and improves the reliability of the housing structure.

[0048] In some embodiments, a thickness of the second plate portion at the second recess is not less than a maximum thickness of the first plate portion.

[0049] In the above solution, the structural strength of the second plate portion can be further improved, thereby reducing the risk of cracking at the second plate portion and improving the reliability of the battery cell.

[0050] In some embodiments, the second side plate includes a fifth plate portion and a sixth plate portion. In the first direction, the sixth plate portion is located on a side of the fifth plate portion close to the shell opening, and the maximum thickness of the sixth plate portion is greater than the maximum thickness of the fifth plate portion.

[0051] In the above solution, the maximum thickness of the sixth plate portion is set to be greater than the maximum thickness of the fifth plate portion, so that the sixth plate portion can have greater structural strength than the fifth plate portion, thereby reducing the risk of cracking and damage due to the expansion stress of the electrode assembly near the welding position between the sixth plate portion and the end cover, thereby improving the reliability of the battery cell.

[0052] In some embodiments, the second side plate further includes a fourth transition portion, the fourth transition portion being located between the fifth plate portion and the sixth plate portion;

[0053] In the first direction and in the direction from the fifth plate portion to the sixth plate portion, the thickness of the fourth transition portion gradually increases; and / or the outer surface of the fifth plate portion is flush with the outer surface of the sixth plate portion.

[0054] In this embodiment, by aligning the outer surface of the fifth plate with the outer surface of the sixth plate, the flatness of the outer surface of the second side plate is improved, enhancing the appearance of the housing. Furthermore, if multiple battery cells are positioned adjacent to each other in the battery, this design reduces the risk of collisions between the cells, improving the reliability of the battery cells.

[0055] In some embodiments, the two first side panels are arranged opposite to each other in the third direction, the two second side panels are arranged opposite to each other in the second direction, the first direction, the second direction, and the third direction intersect each other, and the dimension of the first side panel in the second direction is greater than the dimension of the second side panel in the third direction.

[0056] In the above solution, the dimension of the first side plate in the second direction is greater than the dimension of the second side plate in the third direction, that is, the outer surface dimension of the first side plate can be greater than the outer surface dimension of the second side plate. This design allows the first plate portion of the first side plate to have a larger dimension, thereby allowing the escape space formed by the inward concavity of the first plate portion to have a larger accommodation size, thereby further meeting the expansion requirements of the electrode assembly and improving the corresponding energy density of the battery cell.

[0057] In some embodiments, the first side plate includes a third plate portion disposed circumferentially corresponding to the first plate portion, and the second side plate includes a fifth plate portion disposed circumferentially corresponding to the first plate portion. The first plate portion is directly connected to the third and fifth plate portions, and the inner surfaces of the first, third, and fifth plate portions are smoothly transitioned.

[0058] In the above solution, the first and third panels are directly connected, i.e., there is no other transition structure between them. This improves the smoothness of the transition at the intersection of the inner surfaces of the first and third panels, thereby simplifying the connection between the first side panel and the connecting panel, and improving the reliability of the relative position between them. Furthermore, the first and fifth panels are directly connected, i.e., there is no other transition structure between them. This improves the smoothness of the transition at the intersection of the inner surfaces of the first and fifth panels, thereby simplifying the connection between the second side panel and the connecting panel, and improving the reliability of the relative position between them.

[0059] In some embodiments, the maximum thickness of the second plate portion is H3, the maximum thickness of the fourth plate portion is H2, and H2 and H3 satisfy: 0.1 mm≤H3≤0.8H2.

[0060] In the above solution, the thickness H3 of the second plate portion is set to no less than 0.1 mm, thereby ensuring that the second plate portion has a certain thickness dimension and improving its reliability. Furthermore, the thickness H3 of the second plate portion is set to no more than 0.8H2, thereby reducing the risk of stress concentration at the connecting plate during the shell manufacturing process and the probability of cracking at the connecting plate.

[0061] In a second aspect, an embodiment of the present application provides a battery cell, which includes a shell, an end cover, and an electrode assembly in any of the aforementioned embodiments. The electrode assembly is accommodated in the shell, and the end cover is welded to the second plate, the first side plate, and the second side plate.

[0062] In some embodiments, the battery cell further includes an insulating assembly disposed externally of the electrode assembly and insulating the electrode assembly from the housing. The first side plate includes a third plate portion and a fourth plate portion. In the first direction, the fourth plate portion is located on the side of the third plate portion closest to the housing opening. The inner surface of the third plate portion is recessed relative to the inner surface of the fourth plate portion to form a clearance space. The insulating assembly is at least partially located within the clearance space.

[0063] In the above solution, the insulating assembly is at least partially disposed in the avoidance space, so that there is more space inside the shell for accommodating the electrode assembly, thereby improving the energy density of the battery cell.

[0064] In some embodiments, the insulating assembly includes a first insulating member and a second insulating member, the second insulating member is enclosed to form a hollow structure for accommodating the electrode assembly and having an opening, the first insulating member is located on the side of the second insulating member facing away from the electrode assembly, and the first insulating member is at least partially located in the avoidance space.

[0065] In the above solution, at least part of the first insulating member is arranged in the avoidance space, thereby reducing the occupation of the first insulating member on other spaces inside the shell, so that there is more space inside the shell to accommodate the electrode assembly, thereby improving the energy density of the battery cell.

[0066] In some embodiments, the second insulating member surrounds and connects to form an overlapping area, and the first insulating member is fixed to the overlapping area. In some embodiments, a portion of the electrode assembly is located in the avoidance space.

[0067] In the above solution, the first insulating member is fixed in the overlapping region, thereby reducing the risk of damage or cracking of the second insulating member due to the fixing of the first and second insulating members, thereby improving the structural reliability of the second insulating member. Furthermore, the placement of the first insulating member in the overlapping region also helps reduce the risk of the second insulating member unraveling in the overlapping region, further improving the reliability of the second insulating member.

[0068] In some embodiments, the second insulating member is partially located in the escape space.

[0069] In the above solution, at least part of the structure of the first insulating member and part of the second insulating member are arranged in the avoidance space, thereby further allowing more space inside the shell to accommodate the electrode assembly, thereby improving the energy density of the battery cell.

[0070] In some embodiments, a portion of the electrode assembly is located within the escape space.

[0071] In the above scheme, by controlling the concave size of the third plate portion relative to the fourth plate portion, in addition to the first insulating member and the second insulating member, a part of the structure of the electrode assembly is also located in the avoidance space. In this way, the size of the electrode assembly inside the shell can be further increased without changing the overall size of the battery cell, thereby improving the energy density of the battery cell and increasing the capacity of the battery cell.

[0072] In some embodiments, the first side plate further includes a first transition portion, the first transition portion being located between the third plate portion and the fourth plate portion, the fourth plate portion being located on a side of the third plate portion closer to the housing opening, and the thickness of the first transition portion gradually increasing in a first direction from the third plate portion toward the fourth plate portion. The electrode assembly includes a main body portion and a tab connected to the main body portion, the main body portion being located on a side of the first transition portion facing away from the housing opening.

[0073] In the above solution, by arranging the main body on the side of the first transition portion away from the shell opening, part of the structure in the main body can be more easily accommodated in the avoidance space, thereby improving the energy density of the battery cell. At the same time, the risk of the sharp angle formed by the first transition portion puncturing the main body can be reduced, thereby improving the reliability of the main body.

[0074] In some embodiments, in the first direction, the projection of the main body portion overlaps with the projection of the fourth plate portion; in the thickness direction of the first side plate, the projection of the first transition portion does not overlap with the projection of the main body portion.

[0075] In this solution, by arranging the projection of the main body and the projection of the fourth plate to overlap in the first direction, the main body is partially located within the avoidance space, thereby increasing the energy density of the battery cell. Furthermore, by arranging the projection of the first transition portion to not overlap with the projection of the main body in the thickness direction of the first side plate, the risk of the sharp angle formed by the first transition portion puncturing the main body is reduced, thereby improving the reliability of the main body.

[0076] In some embodiments, the battery cell further includes a second insulating member, which encloses a hollow structure having an opening for accommodating the electrode assembly. The electrode assembly includes a main body and a tab connected to the main body. The second insulating member extends beyond the main body in the first direction by a dimension L1, where L1 satisfies the following: 1 mm ≤ L1 ≤ 10 mm.

[0077] In the above solution, the second insulating member is used to block electrical conduction and friction between the electrode assembly and the housing. Furthermore, in this embodiment of the present application, the second insulating member is positioned beyond the main body in the first direction to enhance the insulating effect of the second insulating member on the electrode assembly. Furthermore, in this embodiment of the present application, the dimension L1 of the second insulating member extending beyond the main body in the first direction is set to be no less than 1 mm to ensure the second insulating member's insulating and protective effect on the main body. Furthermore, the dimension L1 of the second insulating member extending beyond the main body in the first direction is set to be no more than 10 mm to reduce the possibility of the second insulating member being too large occupying excessive space within the battery cell, thereby enhancing the energy density of the battery cell.

[0078] In some embodiments, the second insulating member faces the side of the housing opening, and the distance between the second insulating member and the housing opening in the first direction is L2, and L2 satisfies: 1mm≤L2≤10mm.

[0079] In the above solution, L2 is set to no less than 1mm, which helps to improve the welding strength between the second insulating member and the lower plastic and other insulating structures, thereby improving reliability. At the same time, L2 is also set to no more than 10mm to reduce the space occupied by the second insulating member inside the housing, which helps to increase the energy density of the battery cell.

[0080] In some embodiments, the housing further includes a bottom plate disposed opposite to the housing opening, and the thickness of the bottom plate is W3, where W3 satisfies: 0.7 mm ≤ W3 ≤ 5 mm.

[0081] In the above solution, the thickness of the bottom plate is reduced to no more than 5mm, thereby providing more space for the electrode assembly and improving the energy density of the battery cell. Furthermore, in this embodiment, W3 is set to no less than 0.7mm to ensure that the bottom plate has a certain structural strength, reduce the risk of bottom plate cracking, and improve reliability.

[0082] In some embodiments, the thickness of the second plate portion is less than the thickness of the bottom plate.

[0083] In this embodiment of the present application, to ensure the reliability of the housing's fabrication and its ability to withstand stress, the maximum thickness of the bottom plate is set to be greater than the maximum thickness of the second plate portion. This provides the bottom plate with a certain structural strength, reduces the risk of cracking, and improves reliability. Furthermore, optionally, the maximum thickness of the bottom plate is greater than the maximum thickness of the fourth plate portion; and / or the maximum thickness of the bottom plate is greater than the maximum thickness of the sixth plate portion.

[0084] In some embodiments, the first side panel includes a third panel portion and a fourth panel portion. In the first direction, the fourth panel portion is located on a side of the third panel portion that is closer to the housing opening. The second side panel includes a fifth panel portion and a sixth panel portion. In the first direction, the sixth panel portion is located on a side of the fifth panel portion that is closer to the housing opening. The sixth panel portion is provided with a first recessed portion that is recessed inward from the housing opening. The end cap portion is located within the first recessed portion and is connected to the sixth panel portion and the fourth panel portion.

[0085] In the above scheme, the end cover can be partially located in the first recess, so that the relative position of the end cover can be determined with the help of the first recess. On this basis, the end cover can also be connected and fixed to the fourth plate and the sixth plate by welding, so as to improve the reliability of the relative position between the end cover and the shell.

[0086] In a second aspect, an embodiment of the present application provides a battery comprising a battery cell according to any of the aforementioned embodiments.

[0087] In some embodiments, referring to Figures 20 and 21 , a battery includes a battery cell group and an end plate. The battery cell group includes a plurality of battery cells stacked along a third direction. The first side plate includes a third plate portion and a fourth plate portion. In the first direction, the fourth plate portion is located on a side of the third plate portion that is closer to the housing opening. The maximum thickness of the fourth plate portion is greater than the maximum thickness of the third plate portion. The third direction is parallel to the thickness direction of the first side plate and intersects the first direction. Along the third direction, the end plate is disposed at an end of the battery cell group. In the direction from the third plate portion to the fourth plate portion, the fourth plate portion at least partially extends beyond the end plate.

[0088] In the above solution, the fourth plate portion is arranged beyond the end plate along the direction from the third plate portion to the fourth plate portion. In the direction from the third plate portion to the fourth plate portion, the fourth plate portion may be arranged entirely beyond the end plate, or the fourth plate portion may be arranged only partially beyond the end plate. At least the portion of the structure where the fourth plate portion extends beyond the end plate will not be constrained by the end plate. On this basis, by setting the thickness of the fourth plate portion to be greater than that of the third plate portion, the strength of the portion of the structure not constrained by the end plate is increased, thereby alleviating the risk of cracking due to being constrained by the end plate and improving the reliability of the battery.

[0089] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell according to any of the aforementioned embodiments, wherein the battery cell is used to provide electrical energy.

[0090] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0092] FIG1 is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0093] FIG2 is a schematic diagram of an exploded structure of a battery provided in an embodiment of the present application;

[0094] FIG3 is a schematic structural diagram of a battery module provided in an embodiment of the present application;

[0095] FIG4 is a schematic structural diagram of a housing in a battery cell provided in an embodiment of the present application;

[0096] FIG5 is a schematic diagram of the internal structure of a battery cell provided in an embodiment of the present application;

[0097] FIG6 is a schematic diagram of a housing structure provided in an embodiment of the present application;

[0098] FIG7 is an enlarged schematic diagram of the structure of area P in FIG6;

[0099] FIG8 is a schematic cross-sectional view of a connecting plate in another housing according to an embodiment of the present application;

[0100] FIG9 is a schematic diagram of the internal structure of another battery cell provided in an embodiment of the present application;

[0101] FIG10 is a schematic cross-sectional view of the structure taken along line AA in FIG9 ;

[0102] FIG11 is a schematic diagram of the enlarged structure of area Q in FIG10;

[0103] FIG12 is a schematic diagram of a partial structure of another housing provided in an embodiment of the present application;

[0104] FIG13 is a schematic diagram of a partial structure of another housing provided in an embodiment of the present application;

[0105] FIG14 is an enlarged structural diagram of another housing at area P provided by an embodiment of the present application;

[0106] FIG15 is a schematic cross-sectional view of the structure taken along line BB in FIG9 ;

[0107] FIG16 is a schematic diagram of a partial structure of another housing provided in an embodiment of the present application;

[0108] FIG17 is a schematic diagram of a partial structure of another housing provided in an embodiment of the present application;

[0109] FIG18 is a schematic diagram of a partial structure of another housing provided in an embodiment of the present application;

[0110] FIG19 is a schematic diagram of an exploded structure of some components in another battery cell provided in an embodiment of the present application;

[0111] FIG20 is a schematic diagram of the internal structure of a battery provided in an embodiment of the present application;

[0112] FIG21 is a schematic diagram of a partial cross-sectional structure of a battery provided in an embodiment of the present application.

[0113] In the accompanying drawings: 1000, vehicle; 100, battery; 200, controller; 300, motor; 400, housing; 41, first housing portion; 42, second housing portion; 43, accommodating portion; 500, battery module; 600, battery cell; 610, housing; 10, housing; 11, first side plate; 111, third plate portion; 112, fourth plate portion; 113, first transition portion; 12, second side plate; 121, fifth plate portion; 122, sixth plate portion; 123, fourth transition portion; 13, connecting plate; 131, first plate portion; 132, second plate portion; 1321, plate body; 1322, second transition portion; 1323, third transition portion; 133, fifth transition portion; 14, bottom plate; 20, electrode assembly; 21, main body; 22, tab; 30, first insulating member; 40, second insulating member; 50. End cover; 60. End plate; B1. Center; B2. Edge; K1. Shell opening; J. Insulation assembly; A1. Avoidance space; A2. First recess; A3. Second recess; A4. Recessed space; M1. First transition surface; X. First direction; Y. Second direction; Z. Third direction. DETAILED DESCRIPTION

[0114] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0115] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0116] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0117] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0118] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0119] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0120] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0121] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0122] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0123] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0124] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0125] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0126] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0127] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0128] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0129] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0130] As an example, the negative electrode current collector can be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium can be used. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0131] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0132] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0133] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate.

[0134] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0135] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0136] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical and mechanical stability can be selected.

[0137] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0138] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0139] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0140] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0141] In some embodiments, the electrode assembly is a laminate structure.

[0142] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0143] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0144] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0145] In some embodiments, the housing may be provided with functional components such as electrode terminals, etc. The electrode terminals may be used to electrically connect to the electrode assembly to output or input electrical energy of the battery cell.

[0146] In some embodiments, a current collecting member may be disposed in the housing, and the electrode assembly may be electrically connected to the housing or electrode terminals disposed on the housing through the current collecting member.

[0147] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0148] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0149] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0150] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0151] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0152] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0153] In related art, a housing typically consists of a shell and end caps. The shell includes a first side panel, a second side panel, and a connecting plate connecting the first and second side panels. The connecting plate typically has a curved surface and is less structurally strong than the first and second side panels. Consequently, after the shell and end caps are welded together, stress concentration near the weld between the connecting plate and the end caps is prone to occur due to factors such as expansion of the electrode assembly, leading to cracks and damage in the connecting plate, impacting the reliability of the battery cells.

[0154] Based on the above technical problems, the present application provides a shell, a battery cell, a battery and an electrical device. By setting the maximum thickness of the second plate portion to be greater than the maximum thickness of the first plate portion, the risk of cracking at the connecting plate can be reduced and the reliability of the battery cell can be improved.

[0155] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries, such as mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys and electric tools, etc., among which spacecraft include airplanes, rockets, space shuttles and spacecraft, etc., electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers.

[0156] The battery cells described in the embodiments of the present application are not limited to being applicable to the electrical devices described above, but for the sake of simplicity, the following embodiments are described using electric vehicles as an example.

[0157] Please refer to Figure 1, which is a simple schematic diagram of a vehicle 1000 provided in an embodiment of the present application. 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 vehicle or an extended-range vehicle, etc. A battery 100 can be provided inside the vehicle 1000. For example, the battery 100 can be provided at the bottom, front or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can be used as an operating power source for the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control the battery to power the motor 300, for example. The battery can be used for starting and navigating the vehicle 1000. Of course, the battery 100 can also be used to drive the vehicle 1000, replacing or partially replacing fuel or natural gas to provide drive for the vehicle 1000.

[0158] FIG2 is an exploded view of a battery according to some embodiments of the present application. As shown in FIG2 , the battery 100 includes a housing 400 and battery cells (not shown), with the battery cells being housed in the housing 400 .

[0159] The housing 400 is used to accommodate battery cells and can have various structures. In some embodiments, the housing 400 can include a first housing portion 41 and a second housing portion 42. The first housing portion 41 and the second housing portion 42 overlap each other, and the first housing portion 41 and the second housing portion 42 together define a housing portion 43 for accommodating battery cells. The second housing portion 42 can be a hollow structure with one end open. The first housing portion 41 is a plate-like structure. The first housing portion 41 overlaps the open side of the second housing portion 42 to form a housing with a housing portion 43. The first housing portion 41 and the second housing portion 42 can also be hollow structures with one end open. The open side of the first housing portion 41 overlaps the open side of the second housing portion 42 to form the housing 400 with a housing portion 43. Of course, the first housing portion 41 and the second housing portion 42 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0160] In the battery 100, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery cell structure can be housed within the housing 400. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid configuration to form a battery module 500, and then the multiple battery modules 500 can be connected in series, in parallel, or in a hybrid configuration to form a single unit and housed within the housing 400.

[0161] FIG3 is a schematic structural diagram of the battery module 500 shown in FIG2 .

[0162] In some embodiments, as shown in FIG3 , there are multiple battery cells 600, which are first connected in series, parallel, or in series to form a battery module 500. The multiple battery modules 500 are then connected in series, parallel, or in series to form a whole and housed in a box.

[0163] Figure 4 is a schematic diagram of the structure of a battery cell. Battery cell 600 includes a housing 610 and an electrode assembly 20. Housing 610 is hollow, forming a space for accommodating electrode assembly 20 and other components. Electrode assembly 20 is the primary component of battery cell 600 for providing electrical energy. The shape of housing 610 can be determined based on the specific shape of electrode assembly 20. For example, if electrode assembly 20 is cylindrical, a cylindrical housing can be used; if electrode assembly 20 is rectangular, a rectangular housing can be used.

[0164] 4 , the housing 610 may include a shell 10 and an end cap 50. The shell 10 has a shell opening, and the end cap 50 is used to cover the shell opening of the shell 10. The structure of the shell will be described below with reference to the accompanying drawings.

[0165] Referring to Figures 5 to 8 , the housing 10 has a housing opening K1 at its end along the first direction X. The housing 10 includes a first side plate 11 and a second side plate 12 arranged circumferentially along the housing opening K1. A connecting plate 13 is connected to the first and second side plates 11, 12. At least a portion of the outer surface of the connecting plate 13 comprises a curved surface. The connecting plate 13 includes a first plate portion 131 and a second plate portion 132. In the first direction X, the second plate portion 132 is located on a side of the first plate portion 131 that is closer to the housing opening K1. The maximum thickness of the second plate portion 132 is greater than or equal to the maximum thickness of the first plate portion 131.

[0166] The housing 10 has a housing opening K1 in the first direction X. The number of the housing opening K1 can be one or two. That is, the housing 10 can have the housing opening K1 only at one end in the first direction X, or the housing 10 can have housing openings K1 at two opposite ends in the first direction X. The outer contour of the housing 10 can have various forms. Optionally, the housing 10 can have a cylindrical structure, a rectangular parallelepiped structure, etc.

[0167] The housing 10 includes a first side panel 11, a second side panel 12, and a connecting panel 13. The first side panel 11 and the second side panel 12 are arranged along the circumference of the housing opening K1. The number of first side panels 11 can be one or more, and the number can be set according to the shape of the housing 10. Similarly, the number of second side panels 12 can be one or more, and the number can be set according to the shape of the housing 10. Furthermore, depending on the specific shape of the housing 10, the area corresponding to the outer surface of the first side panel 11 can be larger than the area corresponding to the outer surface of the second side panel 12, or the area corresponding to the outer surface of the first side panel 11 can be less than or equal to the area corresponding to the outer surface of the second side panel 12.

[0168] The first side plate 11 and the second side plate 12 are arranged on different sides of the shell opening K1, and the connecting plate 13 is connected to the first side plate 11 and the second side plate 12. Furthermore, at least part of the outer surface of the connecting plate 13 includes a curved surface. The "outer surface of the connecting plate 13" mentioned here refers to the surface of the connecting plate 13 facing away from the electrode assembly 20. The outer surface of the connecting plate 13 can be a curved surface as a whole, or only partially. At the same time, the inner surface of the connecting plate 13 may include a curved surface, or may not include a curved surface. Optionally, the connecting plate 13 is bent into an arc shape so that its outer surface includes a curved surface.

[0169] In the embodiment of the present application, the outer surface of the connecting plate 13 includes a curved surface, which facilitates a smooth transition between the first side plate 11 and the second side plate 12. The presence of the curved surface also helps improve the flatness of the outer surface of the housing 10, thereby enhancing the appearance of the housing 10.

[0170] The number of connecting plates 13 is generally determined by the number of the first side plate 11 and the second side plate 12. For example, if the housing 10 includes only one first side plate 11 and one second side plate 12, the number of connecting plates 13 is also one. If the housing 10 includes both one first side plate 11 and two second side plates 12, the number of connecting plates 13 is two, one located at each end of the first side plate 11. If the housing 10 includes both two first side plates 11 and two second side plates 12, the number of connecting plates 13 is four, and these four connecting plates 13 are used to connect the two first side plates 11 and the two second side plates 12 end to end.

[0171] The connecting plate 13 includes a first plate portion 131 and a second plate portion 132 arranged side by side in the first direction X. The second plate portion 132 is located on a side of the first plate portion 131 that is closer to the housing opening K1. The first plate portion 131 and the second plate portion 132 may be arranged adjacent to each other in the first direction X, or the first plate portion 131 and the second plate portion 132 may be spaced apart in the first direction X.

[0172] In the embodiment of the present application, the second plate portion 132 is positioned closer to the housing opening K1 than the first plate portion 131. During the mating connection between the housing 10 and the end cap 50, at least a portion of the second plate portion 132 of the connecting plate 13 is welded to the end cap 50. Furthermore, the surface of the second plate portion 132 facing away from the first plate portion 131 is the outer surface of the connecting plate 13 in the first direction X.

[0173] On this basis, the embodiment of the present application sets the maximum thickness of the second plate portion 132 to be no less than the maximum thickness of the first plate portion 131, thereby reducing the risk of cracking and damage caused by shell deformation or battery cell vibration caused by factors such as the expansion stress of the electrode assembly 20 at the welding position of the second plate portion 132 and the end cover 50, thereby improving the reliability of the battery cell 600.

[0174] It should be noted that, depending on actual needs, the thickness of the second plate portion 132 at different locations can be maintained constant, or the thickness of the second plate portion 132 at different locations can be maintained different. Similarly, the thickness of the first plate portion 131 at different locations can be maintained constant, or the thickness of the first plate portion 131 at different locations can be maintained different. On this basis, the embodiments of the present application only need to ensure that the maximum thickness of the second plate portion 132 is greater than the maximum thickness of the first plate portion 131.

[0175] In some embodiments, as shown in Figures 5 to 7 , the first side plate 11 includes a third plate portion 111 and a fourth plate portion 112 . In the first direction X, the fourth plate portion 112 is located on a side of the third plate portion 111 that is closer to the housing opening K1 . The maximum thickness of the fourth plate portion 112 is greater than the maximum thickness of the third plate portion 111 .

[0176] The first side plate 11 includes a third plate portion 111 and a fourth plate portion 112, and the third plate portion 111 and the fourth plate portion 112 are arranged side by side in the first direction X. Optionally, in the circumferential direction of the shell 10, the third plate portion 111 is arranged corresponding to the first plate portion 131, and the fourth plate portion 112 is arranged corresponding to the second plate portion 132. In the first direction X, the fourth plate portion 112 is located on the side of the third plate portion 111 close to the shell opening K1. Furthermore, the third plate portion 111 and the fourth plate portion 112 can be arranged adjacent to each other, or the third plate portion 111 and the fourth plate portion 112 can be arranged at intervals. The size of the fourth plate portion 112 in the first direction X can be the same as or different from the size of the second plate portion 132 in the first direction X.

[0177] Similar to the second plate portion 132 of the connecting plate 13, the fourth plate portion 112 of the first side plate 11 is also welded to the end cap 50. Based on this, in the embodiment of the present application, the maximum thickness of the fourth plate portion 112 is set to be greater than the maximum thickness of the third plate portion 111. This allows the fourth plate portion 112 to have greater structural strength than the third plate portion 111. This reduces the risk of cracking and damage at the weld between the fourth plate portion 112 and the end cap 50 due to the expansion stress of the electrode assembly 20, thereby improving the reliability of the battery cell 600.

[0178] It should be noted that, depending on actual needs, the thickness of the third plate portion 111 at different locations can be maintained equal, or the thickness of the third plate portion 111 at different locations can be maintained different. Similarly, the thickness of the fourth plate portion 112 at different locations can be maintained equal, or the thickness of the fourth plate portion 112 at different locations can be maintained different. On this basis, the embodiment of the present application only needs to meet the requirement that the maximum thickness of the fourth plate portion 112 is greater than the maximum thickness of the third plate portion 111.

[0179] In some embodiments, please refer to Figures 9 to 11 , the inner surface of the third plate portion 111 is concave relative to the inner surface of the fourth plate portion 112; and / or, the inner surface of the first plate portion 131 is concave relative to the inner surface of the second plate portion 132.

[0180] The first side plate 11 has an inner surface and an outer surface along its thickness direction. The inner surface is the surface of the first side plate 11 that faces the electrode assembly 20, and the outer surface is the surface of the first side plate 11 that forms the outer contour of the housing 10. Depending on the shape of the housing 10, the inner and outer surfaces of the first side plate 11 can have various forms. For example, the outer surface of the first side plate 11 can have a certain curvature, or the outer surface of the first side plate 11 can also have a flat structure. The thickness direction of the first side plate 11 is the Z direction shown in Figure 6.

[0181] During insertion of the electrode assembly 20 into the housing, the electrode assembly 20 first moves from the outside to the position within the housing 10 corresponding to the fourth plate portion 112 and the second plate portion 132, and then moves deeper into the housing 10 to the position corresponding to the third plate portion 111 and the first plate portion 131. Therefore, the presence of the fourth plate portion 112 and the second plate portion 132 typically affects the insertion of the electrode assembly 20 into the housing. During use of the battery cell 600, the third plate portion 111 and the first plate portion 131 are positioned around the outer periphery of the electrode assembly 20.

[0182] In the related art, to increase the energy density of the battery cell 600, it is necessary to ensure that the electrode assembly 20 has a certain size and the size of the housing 10 cannot be too large. This results in the distance between the electrode assembly 20 and the third plate portion 111 and the first plate portion 131 being generally small. As a result, when the electrode assembly 20 expands during charging and discharging, the spacing margin between at least one of the first plate portion 131 and the third plate portion 111 and the electrode assembly 20 is difficult to meet the required expansion of the electrode assembly 20. This can cause the first plate portion 131 and the third plate portion 111 to easily deform due to the expansion of the electrode assembly 20 during use of the battery cell 600, which can easily cause the housing 10 to rupture, leading to the risk of failure of the battery cell 600.

[0183] In view of this, in the embodiment of the present application, the inner surface of the third plate portion 111 is recessed relative to the inner surface of the fourth plate portion 112, or the inner surface of the first plate portion 131 is recessed relative to the inner surface of the second plate portion 132, so as to form an escape space A1 on at least one of the first side plate 11 and the connecting plate 13. The escape space A1 is provided corresponding to the first plate portion 131 or the third plate portion 111, and the escape space A1 is used to accommodate the partial structure of the battery cell 600 located within the shell 10. The "partial structure located within the shell 10" mentioned here includes, but is not limited to, the partial structure of the electrode assembly 20, as well as other components located within the shell 10. For example, an insulating component may be present between the electrode assembly 20 and the third plate portion 111, and the insulating component may be at least partially located within the escape space A1.

[0184] In the embodiment of the present application, at least one of the third plate portion 111 and the first plate portion 131 is recessed to form an escape space A1. The existence of the escape space A1 can accommodate part of the structure of the battery cell 600, thereby maximizing the distance between the third plate portion 111 or the first plate portion 131 and the electrode assembly 20 without reducing the size of the electrode assembly 20. Furthermore, when the electrode assembly 20 expands, the escape space A1 can withstand a certain amount of expansion of the electrode assembly 20, thereby reducing the deformation of the third plate portion 111 or the first plate portion 131 caused by the expansion of the electrode assembly 20, reducing the risk of cracks in the housing 10, and improving the reliability of the housing 10 and the corresponding battery cell 600.

[0185] It should be noted that although the inner surface of the third plate portion 111 is concave relative to the inner surface of the fourth plate portion 112, the outer surface of the third plate portion 111 can be flush with the outer surface of the fourth plate portion 112, or the outer surface of the third plate portion 111 can be concave or convex relative to the outer surface of the fourth plate portion 112. Similarly, the outer surface of the first plate portion 131 can be flush with the outer surface of the second plate portion 132, or the outer surface of the first plate portion 131 can be concave or convex relative to the outer surface of the second plate portion 132.

[0186] In some embodiments, the outer surface of the third plate portion 111 is flush with the outer surface of the fourth plate portion 112 ; and / or the outer surface of the first plate portion 131 is flush with the outer surface of the second plate portion 132 .

[0187] In the embodiment of the present application, by arranging the outer surface of the third plate portion 111 flush with the outer surface of the fourth plate portion 112, the flatness of the outer surface of the first side plate 11 can be improved, the risk of damage caused by collisions with other components due to protruding structures on the outer surface of the first side plate 11 is reduced, and the reliability of the first side plate 11 is improved. Similarly, by arranging the outer surface of the first plate portion 131 flush with the outer surface of the second plate portion 132, the flatness of the outer surface of the connecting plate 13 can be improved, the risk of damage caused by collisions with other components due to protruding structures on the outer surface of the connecting plate 13 is reduced, and the reliability of the connecting plate 13 is improved.

[0188] In some embodiments, as shown in FIG11 , the maximum thickness of the third plate portion 111 is H1, and the maximum thickness of the fourth plate portion 112 is H2, where H1 and H2 satisfy the relationship: 0.05 mm ≤ H2 - H1 ≤ 0.3 mm. Alternatively, H2 - H1 is one of 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, and 0.3 mm.

[0189] As can be seen from the foregoing, the inner surface of the third plate portion 111 is recessed relative to the inner surface of the fourth plate portion 112 to form an escape space A1 for accommodating a portion of the structure. On this basis, the thickness difference between the third plate portion 111 and the fourth plate portion 112 is positively correlated with the size of the escape space A1. Specifically, the smaller the thickness difference between the third plate portion 111 and the fourth plate portion 112, the smaller the size of the corresponding escape space A1 in the thickness direction of the third plate portion 111; similarly, the greater the thickness difference between the third plate portion 111 and the fourth plate portion 112, the larger the size of the corresponding escape space A1 in the thickness direction of the third plate portion 111. The thickness direction of the third plate portion 111 is the thickness direction of the first side plate 11.

[0190] Furthermore, in this embodiment of the present application, the maximum thickness H1 of the third plate portion 111 and the maximum thickness H2 of the fourth plate portion 112 are set to H2-H1≤0.3mm, i.e., the thickness difference between the third plate portion 111 and the fourth plate portion 112 is limited to no more than 0.3mm. This design can reduce the problem of low reliability of the third plate portion 111 due to a too small thickness, while also reducing the risk of difficulty in inserting the electrode assembly 20 into the battery housing due to an excessive thickness of the fourth plate portion 112. This achieves a comprehensive consideration of the difficulty of manufacturing the battery cell 600 and its reliability in use, and has strong practicality.

[0191] Furthermore, if the thickness difference H2-H1 between the third plate portion 111 and the fourth plate portion 112 is too small, the avoidance space A1 may not be able to accommodate the component structures within the battery cell 600. Therefore, in this embodiment of the present application, the thickness difference between the third plate portion 111 and the fourth plate portion 112 is set to be no less than 0.05 mm. This ensures that at least part of the structure within the battery cell 600 can be accommodated within the avoidance space A1. This reduces the deformation of the third plate portion 111 while improving the internal space utilization of the battery cell 600 and increasing the energy density of the battery cell 600.

[0192] In some embodiments, the first side plate 11 further includes a first transition portion 113, which is located between the third plate portion 111 and the fourth plate portion 112. In the first direction X and from the third plate portion 111 to the fourth plate portion 112, the thickness of the first transition portion 113 gradually increases.

[0193] The first transition portion 113 is located between the third plate portion 111 and the fourth plate portion 112 in the first direction X. The first transition portion 113 is used to achieve a transition from the third plate portion 111 to the fourth plate portion 112. In the first direction X, the first transition portion 113 can be disposed adjacent to the third plate portion 111, or the first transition portion 113 can be spaced apart from the third plate portion 111. Similarly, in the first direction X, the first transition portion 113 can be disposed adjacent to the fourth plate portion 112, or the first transition portion 113 can be spaced apart from the fourth plate portion 112.

[0194] In an embodiment of the present application, the first transition portion 113 is located between the third plate portion 111 and the fourth plate portion 112. Since the inner surface of the third plate portion 111 can be concave relative to the inner surface of the fourth plate portion 112, the embodiment of the present application gradually increases the thickness of the first transition portion 113 in the direction from the third plate portion 111 to the fourth plate portion 112, so as to achieve a smooth transition between the third plate portion 111 and the fourth plate portion 112 with the help of the first transition portion 113, reduce the molding difficulty of the shell 10, reduce stress concentration, and reduce the risk of cracking of the first side panel 11.

[0195] In some embodiments, as shown in FIG11 , the first transition portion 113 includes a first transition surface M1 facing the interior of the housing 10 . The angle α between the first transition surface M1 and the first direction X satisfies the following: 0<α≤60°. Optionally, the value of α is one of 10°, 15°, 20°, 40°, and 60°.

[0196] The first transition surface M1 is the surface of the first transition portion 113 facing the electrode assembly 20. As can be seen from the foregoing, the avoidance space A1 can be used to accommodate at least a portion of the structure of the battery cell 600. Optionally, the battery cell 600 can include a second insulating member 40. The second insulating member 40 is located between the first side plate 11 and the electrode assembly 20 to insulate the electrode assembly 20 from the first side plate 11. At least a portion of the second insulating member 40 can be located within the avoidance space A1.

[0197] Furthermore, during use of the battery cell 600, the electrode assembly 20, second insulating member 40, or other components within the battery cell 600 may easily come into contact with the first transition surface M1 due to factors such as shaking. If the inclination angle of the first transition surface M1 relative to the first direction X is too large, the interface between the first transition surface M1 and the inner surface of the third plate portion 111, as well as the interface between the first transition surface M1 and the inner surface of the fourth plate portion 112, may be too sharp, thereby increasing the risk of puncturing the electrode assembly 20 and the second insulating member 40.

[0198] Furthermore, during the production of the housing 10, a drafting process is typically required. Drafting is typically used to add an inclination to the vertical surfaces of a model, component, mold, or die, so that the component or model can be separated from the mold or die using the draft surface. Furthermore, if the angle between the first transition surface M1 and the first direction X is too large, this can increase the difficulty of drafting during the production of the housing 10, hindering the production of the housing 10.

[0199] In view of this, the embodiment of the present application sets the angle α between the first transition surface M1 and the first direction X to no greater than 60°, thereby reducing the risk of puncturing the electrode assembly 20 and the first insulating member 30, and improving the reliability of the battery cell 600. This design also helps to reduce the difficulty of demolding the housing 10, thereby improving the production yield of the housing 10.

[0200] In some embodiments, 2°≤α≤40°. Optionally, the value of α is 2°, 15°, 20°, 30°, 40°, etc.

[0201] In this embodiment of the present application, by setting the angle α between the first transition surface M1 and the first direction X to no greater than 40°, the risk of puncturing the electrode assembly 20 and the first insulating member 30 is further reduced, thereby improving the reliability of the battery cell 600. This also helps to further reduce the difficulty of mold removal during the production of the housing 10, thereby improving the production yield of the housing 10. Furthermore, this embodiment of the present application also sets α to no less than 2° to ensure that the third plate portion 111 has a certain thickness dimension to meet the reliability requirements of the battery cell 600.

[0202] In some embodiments, the maximum thickness of the second plate portion 132 is H3, the maximum thickness of the fourth plate portion 112 is H2, and H2 and H3 satisfy: 0.1 mm≤H3≤0.8H2.

[0203] In view of this, the embodiment of the present application sets the maximum thickness H3 of the second plate portion 132 to no less than 0.1 mm, thereby ensuring that the second plate portion 132 has a certain thickness dimension and improving its reliability. Furthermore, the maximum thickness H3 of the second plate portion 132 is set to no more than 0.8H2, thereby reducing the risk of stress concentration at the connecting plate 13 during the production process of the housing 10 and reducing the probability of cracking at the connecting plate 13.

[0204] In some embodiments, the maximum thickness of the second plate portion 132 is not greater than the maximum thickness of the fourth plate portion 112; and / or, the difference between the maximum thicknesses corresponding to the second plate portion 132 and the first plate portion 131 is not greater than the difference between the maximum thicknesses corresponding to the fourth plate portion 112 and the third plate portion 111.

[0205] During the insertion of the electrode assembly 20 into the housing, the electrode assembly 20 first moves from the outside to the position within the housing 10 corresponding to the second plate portion 132, and then moves deeper into the housing 10 to the position corresponding to the first plate portion 131. That is, after the electrode assembly 20 is inserted into the housing, the electrode assembly 20 is positioned corresponding to the first plate portion 131.

[0206] Furthermore, since the outer surface of the connecting plate 13 may include an arc surface, during the demolding process of the shell 10, the material has nowhere to flow, resulting in an increased risk of deformation and flanging of the connecting plate 13 at the position of the second plate portion 132. At the same time, stress is easily concentrated on the connecting plate 13 during the demolding process, which may cause the connecting plate 13 to crack.

[0207] In view of this, the embodiment of the present application can set the maximum thickness of the second plate portion 132 to be no greater than the maximum thickness of the fourth plate portion 112, so that the thickness of the second plate portion 132 is relatively small, thereby reducing the difficulty of demolding the shell 10 at the position of the connecting plate 13, and reducing the risk of the connecting plate 13 turning outward and cracking, thereby improving the production yield of the shell 10.

[0208] Alternatively, in the embodiment of the present application, the difference between the maximum thicknesses corresponding to the second plate portion 132 and the first plate portion 131 can be set to be no greater than the difference between the maximum thicknesses corresponding to the fourth plate portion 112 and the third plate portion 111. That is, the difference between the maximum thickness of the second plate portion 132 and the maximum thickness of the first plate portion 131 is no greater than the difference between the maximum thickness of the fourth plate portion 112 and the maximum thickness of the third plate portion 111. This design ensures that the thickening dimension of the second plate portion 132 relative to the first plate portion 131 is no greater than the thickening dimension of the fourth plate portion 112 relative to the third plate portion 111. This also helps to reduce the difficulty of demolding the shell 10 at the position of the connecting plate 13, and reduces the risk of the connecting plate 13 turning outward and cracking, thereby improving the production yield rate of the shell 10.

[0209] In some embodiments, as shown in Figures 7, 9, and 11, the two second side panels 12 are arranged relative to each other in the second direction Y, with the first direction X intersecting the second direction Y. The fourth panel 112 includes a central portion B1 and an edge portion B2 located at least to one side of the central portion B1 along the second direction Y. The edge portion B2 is connected to the second panel 132, and the maximum thickness of the edge portion B2 is less than the maximum thickness of the central portion B1. In Figure 9, the relative positions of the central portion B1 and the edge portion B2 are indicated by arrows.

[0210] The fourth plate portion 112 includes a central portion B1 and an edge portion B2. The edge portion B2 is located on at least one side of the central portion B1 along the second direction Y. Depending on actual needs, the number of edge portions B2 can be one or two. When there are two edge portions B2, the two edge portions B2 are located on either side of the central portion B1 along the second direction Y.

[0211] The maximum thickness of the edge portion B2 is less than the maximum thickness of the center portion B1, so the maximum thickness of the fourth plate portion 112 is equal to the maximum thickness of the center portion B1. The maximum thickness of the edge portion B2 can be greater than the maximum thickness of the third plate portion 111, or the maximum thickness of the edge portion B2 can be equal to the maximum thickness of the third plate portion 111.

[0212] In the embodiment of the present application, the maximum thickness of the edge portion B2 in the fourth plate portion 112 is less than the maximum thickness of the center portion B1. The existence of the edge portion B2 makes the fourth plate portion 112 partially unthickened or partially thickened to a smaller size, which helps to reduce the demolding difficulty corresponding to the fourth plate portion 112 and improve the production yield of the shell 10.

[0213] In some embodiments, a dimension of the center portion B1 in the second direction Y is Z1 , a dimension of the housing 10 in the second direction Y is Z2 , and Z1 and Z2 satisfy: 0.5≤Z1 / Z2.

[0214] From the foregoing, it can be seen that the presence of the edge portion B2 helps to reduce the difficulty of demolding corresponding to the fourth plate portion 112. If the size of the edge portion B2 is too large, the size of the center portion B1 will be too small, which will affect the structural strength of the fourth plate portion 112, resulting in cracking and damage after the fourth plate portion 112 is welded to the end cover 50. At the same time, it may also cause the risk of laser leakage at the position of the fourth plate portion 112 during the welding process of the shell 10 and the end cover 50.

[0215] In view of this, the embodiment of the present application limits the size of the center portion B1 in the second direction Y, such that the dimension Z1 of the center portion B1 in the second direction Y is not less than half the dimension of the housing 10 in the second direction Y. This improves the structural reliability of the fourth plate portion 112 and reduces the risk of cracking and damage in the fourth plate portion 112.

[0216] In some embodiments, referring to Figures 12 and 13 , the angle β between the inner surface of the second plate portion 132 and the inner surface of the fourth plate portion 112 satisfies the following relationship: 155°≤β≤270°. Alternatively, the value of β is one of 155°, 175°, 180°, 210°, 250°, and 270°.

[0217] As can be seen from the foregoing, the outer surface of the second plate portion 132 comprises a curved surface. Based on this, in order to ensure that the thickness of the second plate portion 132 is less than that of the fourth plate portion 112, it is necessary to limit the angle β between the inner surface of the fourth plate portion 112 and the inner surface of the second plate portion 132. Furthermore, experiments have shown that when β is less than 155°, the thickness of the second plate portion 132 is relatively large, which has little impact on improving the demolding difficulty and reducing the risk of cracking at the connecting plate 13. Therefore, in this embodiment of the present application, β is set to no less than 155°, which helps reduce the thickness of the second plate portion 132, thereby improving the demolding difficulty and reducing the risk of cracking.

[0218] Furthermore, experiments have shown that when β is greater than 270°, the difficulty of manufacturing the housing 10 increases significantly, resulting in a decrease in the efficiency of forming the housing 10. This can also adversely affect the weld between the housing 10 and the end cap 50, resulting in insufficient weld strength. In view of this, the present embodiment further sets β to no greater than 270°, thereby reducing the difficulty of manufacturing the housing 10, improving the efficiency of forming the housing 10, and also helping to strengthen the weld strength formed by welding.

[0219] In summary, in the embodiment of the present application, by setting β to no less than 155°, the thickness of the second plate portion 132 is reduced, thereby improving the difficulty of demolding and reducing the risk of cracking. Furthermore, by setting β to no more than 270°, the difficulty of separating the housing 10 is reduced, the efficiency of forming the housing 10 is improved, and the strength of the weld formed by welding is enhanced.

[0220] In some embodiments, as shown in Figures 12 and 13, the second plate portion 132 includes a plate body 1321 and a second transition portion 1322 connecting the plate body 1321 and the fourth plate portion 112. The maximum thickness of the plate body 1321 is less than the maximum thickness of the second transition portion 1322. The thickness of the second transition portion 1322 gradually increases as it approaches the fourth plate portion 112.

[0221] According to actual usage needs, the thickness of the fourth plate portion 112 can be greater than the thickness of the second plate portion 132. If the thickness of the second plate portion 132 is suddenly reduced at the junction of the fourth plate portion 112 and the second plate portion 132, it will easily lead to the structural strength at the junction of the fourth plate portion 112 and the second plate portion 132 being too low, and it will also increase the difficulty of preparing the shell 10, which is not suitable for actual production use.

[0222] In the embodiment of the present application, the second plate portion 132 is provided with a second transition portion 1322 and a plate body 1321. The plate body 1321 is the main portion of the second plate portion 132, and the maximum thickness of the plate body 1321 is less than the maximum thickness of the second transition portion 1322. The second transition portion 1322 enables the plate body 132 to be connected to the fourth plate portion 112.

[0223] Furthermore, in order to reduce the situation where thickness mutations occur at some positions in the shell 10, the embodiment of the present application also sets the thickness of the second transition portion 1322 to gradually increase in the direction close to the fourth plate portion 112, so as to achieve a reliable transition between the fourth plate portion 112 and the plate body 1321, improve the reliability of the junction between the fourth plate portion 112 and the second plate portion 132, and reduce the difficulty of preparing the shell 10.

[0224] In some embodiments, as shown in FIG13 , the two second side panels 12 are disposed opposite each other in the second direction Y, with the first direction X intersecting the second direction Y. The second transition portion 1322 has a dimension L1 in the second direction Y, where L1 satisfies the following: 1 mm ≤ L1 ≤ 15 mm. Alternatively, L1 can be 1 mm, 2 mm, 5 mm, 8 mm, 10 mm, 15 mm, and so on.

[0225] The two second side panels 12 are arranged relative to each other in the second direction Y. Optionally, the second direction Y can be arranged perpendicular to the first direction X. Furthermore, if the outer surface of the first side panel 11 is a flat surface, the second direction Y can be parallel to the outer surface of the first side panel 11. In the second direction Y, the size of the second transition portion 1322 is L1. And in the direction close to the fourth plate portion 112, the thickness of the second transition portion 1322 tends to gradually increase. On this basis, if the value of L1 is too large, it is easy to cause the thickness at the junction of the second transition portion 1322 and the plate body 1321 to be too small, which is not conducive to the welding reliability between the shell 10 and the end cover 50. If the value of L1 is too small, the thickness of the second transition portion 1322 changes too much, which is easy to have an adverse effect on the demolding process of the shell 10.

[0226] In view of this, the embodiment of the present application sets the dimension L1 of the second transition portion 1322 to no less than 1 mm, thereby helping to reduce the difficulty of demolding the housing 10 and improving the production efficiency of the housing 10. At the same time, the dimension L1 of the second transition portion 1322 is set to no more than 15 mm, thereby helping to improve the welding strength between the housing 10 and the end cap 50, and improving the reliability of the subsequently formed battery cell 600.

[0227] In some embodiments, the inner surface of the second transition portion 1322 includes a curved surface structure; and / or, the inner surface of the second transition portion 1322 includes a flat surface structure.

[0228] In an embodiment of the present application, the second transition portion 1322 is used to connect the fourth plate portion 112 and the plate main body 1321. On this basis, in order to improve the structural reliability of the shell 10, the embodiment of the present application sets the inner surface of the second transition portion 1322 to include at least one of a curved surface structure and a plane structure. With the help of the curved surface structure, a smooth transition between the fourth plate portion 112 and the plate main body 1321 can be achieved, and with the help of the plane structure, a smooth transition between the fourth plate portion 112 and the plate main body 1321 can be achieved. In this way, the structural reliability of the shell 10 at the junction of the fourth plate portion 112 and the second plate portion 132 can be improved, and at the same time, the stress concentration at the position of the connecting plate 13 can be improved, thereby reducing the risk of cracking of the connecting plate 13.

[0229] It should be noted that the outer surface of the second transition portion 1322 can have various forms. For example, the outer surface of the second transition portion 1322 can include a flat structure and be flush with the outer surface of the fourth plate portion 112. Alternatively, the outer surface of the second transition portion 1322 can include a curved surface structure to achieve a smooth transition with the outer surface of the plate body 1321.

[0230] Furthermore, when the inner surface of the second transition portion 1322 includes a curved surface structure, the radius corresponding to the curved surface structure can have various sizes. Optionally, the radius of the curved surface structure is no less than 0.05 mm and no greater than half the thickness difference between the plate body 1321 and the first plate portion 131. This allows the curved surface structure to have a certain radius size, thereby reducing stress concentration issues and reducing the problem of the plate body 1321 being too small due to an excessively large radius of the curved surface structure. Optionally, the radius of the curved surface structure is 0.05 mm, 0.06 mm, 0.08 mm, 0.1 mm, etc.

[0231] In some embodiments, as shown in FIG16 , the maximum thickness H3 of the second plate portion 132 is greater than the maximum thickness H7 of the first plate portion 131. The connecting plate 13 further includes a fifth transition portion 133, which is located between the first plate portion 131 and the second plate portion 132. The thickness of the fifth transition portion 133 gradually increases in the first direction X from the first plate portion 131 to the second plate portion 132.

[0232] The fifth transition portion 133 is located between the first plate portion 131 and the second plate portion 132 in the first direction X. The fifth transition portion 133 is used to achieve a transition from the first plate portion 131 to the second plate portion 132. In the first direction X, the fifth transition portion 133 can be disposed adjacent to the first plate portion 131, or the fifth transition portion 133 can be spaced apart from the first plate portion 131. Similarly, in the first direction X, the fifth transition portion 133 can be disposed adjacent to the second plate portion 132, or the fifth transition portion 133 can be spaced apart from the second plate portion 132.

[0233] In an embodiment of the present application, the fifth transition portion 133 is located between the first plate portion 131 and the second plate portion 132. Since the maximum thickness of the second plate portion 132 is greater than or equal to the maximum thickness of the first plate portion 131, the embodiment of the present application gradually increases the thickness of the fifth transition portion 133 in the direction from the first plate portion 131 to the second plate portion 132, so as to achieve a smooth transition between the first plate portion 131 and the second plate portion 132 with the help of the fifth transition portion 133, reduce the molding difficulty of the shell 10, reduce stress concentration, and reduce the risk of cracking of the first side panel 11.

[0234] In some embodiments, referring to Figures 5, 14 and 15, the second side plate 12 includes a fifth plate portion 121 and a sixth plate portion 122. In the first direction X, the sixth plate portion 122 is located on the side of the fifth plate portion 121 close to the shell opening K1. The sixth plate portion 122 is provided with a first recess A2 formed inwardly from the shell opening K1. The first recess A2 is used to receive the end cover 50.

[0235] The sixth plate portion 122 is provided with a first recess A2 for receiving the end cap 50. Due to the presence of the first recess A2, the thickness of the sixth plate portion 122 is relatively thinner at the location corresponding to the first recess A2, resulting in different thicknesses at different locations on the sixth plate portion 122. Optionally, the sixth plate portion 122 has a two-part structure in the first direction, one part relatively close to the fifth plate portion 121 and the other part relatively far away from the fifth plate portion 121. On this basis, the thickness of the portion of the sixth plate portion 122 relatively close to the fifth plate portion 121 is greater than the thickness of the portion relatively far away from the fifth plate portion 121, thereby forming the first recess A2.

[0236] In the embodiment of the present application, a first recess A2 is provided at the sixth plate portion 122 so that the end cover 50 can be partially located within the first recess A2, thereby enabling the relative position of the end cover 50 to be determined with the aid of the first recess A2, thereby improving the reliability of the relative position between the end cover 50 and the shell 10.

[0237] It should be noted that the thickness dimension H8 of the sixth plate portion 122 corresponding to the first recess A2 can be greater than the maximum thickness of the fifth plate portion 121, or the thickness dimension of the sixth plate portion 122 corresponding to the first recess A2 can also be less than or equal to the maximum thickness of the fifth plate portion 121.

[0238] In some embodiments, the thickness dimension H8 of the sixth plate portion 122 at the first recess A2 is not less than the maximum thickness of the fifth plate portion 121. This can further improve the structural strength of the sixth plate portion 122, thereby reducing the risk of cracking at the sixth plate portion 122 and improving the reliability of the battery cell 600.

[0239] In some embodiments, the first side plate 11 includes a third plate portion 111 and a fourth plate portion 112 . In the first direction X, the fourth plate portion 112 is located on a side of the third plate portion 111 that is closer to the housing opening K1 . In the first direction X, the size of the sixth plate portion 122 is greater than or equal to that of the fourth plate portion 112 .

[0240] As can be seen from the foregoing, the sixth plate portion 122 is provided with a first recess A2, and the second recess A3 is primarily used to accommodate the end cap 50, thereby improving the connection reliability between the end cap 50 and the housing 10. Optionally, the dimension of the first recess A2 in the first direction X may be greater than or equal to the thickness of the end cap 50, so that the end cap 50 can fully penetrate into the first recess A2.

[0241] Optionally, because the sixth plate portion 122 is provided with the first recess A2, in order to improve the molding accuracy of the second side plate 12, the embodiment of the present application adjusts the dimensions of the sixth plate portion 122 so that the dimension of the sixth plate portion 122 in the first direction X is greater than or equal to the dimension of the fourth plate portion 112 in the first direction X. This ensures that the sixth plate portion 122 has a certain dimension in the first direction X to meet the requirements of the first recess A2. Furthermore, the first recess A2 improves the connection strength between the housing 10 and the end cap 50, thereby enhancing the reliability of the subsequently formed battery cell 600. Furthermore, optionally, the dimension difference between the sixth plate portion 122 and the fourth plate portion 112 in the first direction X is less than the dimension of the first recess A2, thereby helping to improve production efficiency and yield.

[0242] In addition, by setting the size of the sixth plate portion 122 in the first direction X to be greater than or equal to the size of the fourth plate portion 112 in the first direction X, the structural strength difference between the sixth plate portion 122 and the fourth plate portion 112 caused by the existence of the first recess A2 can be reduced, thereby further reducing the risk of cracking of the sixth plate portion 122 and improving overall reliability.

[0243] In some embodiments, referring to FIG. 16 and FIG. 17 , the second plate portion 132 is provided with a second recess A3 recessed inwardly from the housing opening K1 , and the first recess A2 is communicated with the second recess A3 .

[0244] In addition to the first recess A2, the embodiment of the present application also includes a second recess A3. Both the first recess A2 and the second recess A3 are used to receive the end cap 50. This improves the reliability of the relative position of the end cap 50 relative to the second side plate 12 and the connecting plate 13, thereby helping to improve the reliability of the connection between the end cap 50 and the housing 10. Furthermore, the embodiment of the present application also connects the first recess A2 and the second recess A3. This helps reduce the risk of a sudden change in the thickness of the housing 10 at the junction of the first recess A2 and the second recess A3, reduces the difficulty of manufacturing the housing 10, and improves the reliability of the housing 10 structure.

[0245] It should be noted that Figures 16 and 17 illustrate two types of connecting plate 13 structures. In Figure 16 , the second plate portion 132 includes portions having different thicknesses, and the minimum thickness of the second plate portion 132 is the same as the maximum thickness of the first plate portion 131. In Figure 17 , the second plate portion 132 also includes portions having different thicknesses, but the maximum thickness of the second plate portion 132 is the same as the maximum thickness of the first plate portion 131. The second plate portion 132 and the first plate portion 131 can be divided by the dotted line between the second plate portion 132 and the first plate portion 131 in Figure 17 .

[0246] In some embodiments, as shown in FIG16 , the thickness H6 of the second plate portion 132 at the second recess A3 is not less than the maximum thickness H7 of the first plate portion 131. This can further enhance the structural strength of the second plate portion 132, thereby reducing the risk of cracking in the second plate portion 132 and improving the reliability of the battery cell 600.

[0247] In other embodiments not shown, the thickness of the second plate portion 132 at the second recess A3 is smaller than the maximum thickness H7 of the first plate portion 131 .

[0248] 14 and 15 , the second side plate 12 includes a fifth plate portion 121 and a sixth plate portion 122 . In the first direction X, the sixth plate portion 122 is located on a side of the fifth plate portion 121 that is closer to the housing opening K1 . The maximum thickness H4 of the sixth plate portion 122 is greater than the maximum thickness H5 of the fifth plate portion 121 .

[0249] The second side plate 12 includes a fifth plate portion 121 and a sixth plate portion 122. The fifth plate portion 121 and the sixth plate portion 122 are arranged side by side in the first direction X. Optionally, the fifth plate portion 121 is arranged corresponding to the first plate portion 131, and the sixth plate portion 122 is arranged corresponding to the second plate portion 132. In the first direction X, the sixth plate portion 122 is located on the side of the fifth plate portion 121 that is closest to the housing opening K1. Furthermore, the fifth plate portion 121 and the sixth plate portion 122 can be arranged adjacent to each other, or the fifth plate portion 121 and the sixth plate portion 122 can be arranged with a gap between them.

[0250] Optionally, the second side panel 12 further includes a fourth transition portion 123. The fourth transition portion 123 is located between the fifth panel 121 and the sixth panel 122. The thickness of the fourth transition portion 123 gradually increases in the first direction X from the fifth panel 121 to the sixth panel 122. The fourth transition portion 123 can reduce the difficulty of molding the housing 10.

[0251] Similar to the second plate portion 132 of the connecting plate 13, the sixth plate portion 122 of the second side plate 12 is also welded to the end cap 50. Based on this, in this embodiment of the present application, the maximum thickness H4 of the sixth plate portion 122 is set to be greater than the maximum thickness H5 of the fifth plate portion 121. This allows the sixth plate portion 122 to have greater structural strength than the fifth plate portion 121. This reduces the risk of cracking and damage near the welding point between the sixth plate portion 122 and the end cap 50 due to the expansion stress of the electrode assembly 20, thereby improving the reliability of the battery cell 600.

[0252] It should be noted that, depending on actual needs, the thickness of the fifth plate portion 121 at different locations can remain the same, or the thickness of the fifth plate portion 121 at different locations can also remain different. Similarly, the thickness of the sixth plate portion 122 at different locations can remain the same, or the thickness of the sixth plate portion 122 at different locations can also remain different. On this basis, the embodiment of the present application only needs to meet the maximum thickness H4 of the sixth plate portion 122 greater than the maximum thickness H5 of the fifth plate portion 121.

[0253] In some embodiments, the outer surface of the fifth plate portion 121 is flush with the outer surface of the sixth plate portion 122 .

[0254] The outer surface of the fifth plate portion 121 is the surface of the fifth plate portion 121 facing away from the electrode assembly 20, and the outer surface of the sixth plate portion 122 is the surface of the sixth plate portion 122 facing away from the electrode assembly 20. The maximum thickness of the sixth plate portion 122 is greater than the maximum thickness of the fifth plate portion 121. Based on this, in this embodiment of the present application, the outer surface of the fifth plate portion 121 is arranged flush with the outer surface of the sixth plate portion 122, so that the inner surface of the sixth plate portion 122 at least partially protrudes from the inner surface of the fifth plate portion 121.

[0255] Further optionally, the minimum thickness of the sixth plate portion 122 is greater than or equal to the maximum thickness of the fifth plate portion 121. In other words, the thickness of the sixth plate portion 122 at the position corresponding to the first recess A2 is still greater than or equal to the maximum thickness H5 of the fifth plate portion 121. This helps to improve the welding reliability between the sixth plate portion 122 and the end cover 50.

[0256] In the embodiment of the present application, by aligning the outer surface of the fifth plate portion 121 with the outer surface of the sixth plate portion 122, the flatness of the outer surface of the second side plate 12 is improved, thereby enhancing the appearance of the housing 10. Furthermore, if multiple battery cells 600 are positioned adjacent to each other in a battery, this design can reduce the risk of collisions between the different battery cells 600, thereby improving the reliability of the battery cells 600.

[0257] In some embodiments, the two first side panels 11 are disposed opposite each other in the third direction Z, and the two second side panels 12 are disposed opposite each other in the second direction Y. The first direction X, the second direction Y, and the third direction Z intersect with each other. The dimension of the first side panel 11 in the second direction Y is greater than the dimension of the second side panel 12 in the third direction Z.

[0258] The two first side panels 11 and the two second side panels 12 are alternately arranged along the circumference of the housing opening K1. Optionally, the first side panels 11 and the second side panels 12 are arranged perpendicularly in the first direction X, the second direction Y, and the third direction Z, so that the first side panels 11 and the second side panels 12 are relatively perpendicular. Further, optionally, the number of connecting panels 13 can be four, each connecting panel 13 being used to connect adjacent first side panels 11 and second side panels 12.

[0259] Furthermore, the dimension of the first side plate 11 in the second direction Y is greater than the dimension of the second side plate 12 in the third direction Z. That is, the outer surface dimension of the first side plate 11 can be greater than the outer surface dimension of the second side plate 12. This design allows the third plate portion 111 of the first side plate 11 to have a larger dimension, thereby allowing the avoidance space A1 formed by the inward recess of the third plate portion 111 to have a larger accommodation dimension, thereby further meeting the expansion requirements of the electrode assembly 20 and improving the corresponding energy density of the battery cell 600. Furthermore, the first recess A2 provided on the second side plate 12 can be used to meet the assembly requirements of the end cap 50, improving the reliability of the relative position between the housing 10 and the end cap 50.

[0260] In some embodiments, referring to Figures 5 and 18 , the first side plate 11 includes a third plate portion 111 disposed circumferentially of the housing 10 in correspondence with the first plate portion 131, and the second side plate 12 includes a fifth plate portion 121 disposed circumferentially of the housing 10 in correspondence with the first plate portion 131. The first plate portion 131 is directly connected to the third plate portion 111 and the fifth plate portion 121, and the inner surfaces of the first plate portion 131, the third plate portion 111, and the fifth plate portion 121 are smoothly transitioned.

[0261] In the embodiment of the present application, the first plate portion 131 is directly connected to the third plate portion 111, that is, there is no other transition structure between the two. This improves the smoothness of the transition at the intersection of the inner surface of the first plate portion 131 and the inner surface of the third plate portion 111, thereby helping to simplify the connection between the first side plate 11 and the connecting plate 13 and improve the reliability of the relative position between the two. In addition, the first plate portion 131 is directly connected to the fifth plate portion 121, that is, there is no other transition structure between the two. This improves the smoothness of the transition at the intersection of the inner surface of the first plate portion 131 and the inner surface of the fifth plate portion 121, thereby helping to simplify the connection between the second side plate 12 and the connecting plate 13 and improve the reliability of the relative position between the two.

[0262] It should be noted that the thicknesses of the third plate portion 111 and the fifth plate portion 121 may be different. For example, the thickness of the third plate portion 111 is less than the thickness of the fifth plate portion 121. Based on this, the thickness of the first plate portion 131 may decrease gradually as it approaches the third plate portion 111, and may increase gradually as it approaches the fifth plate portion 121.

[0263] On the second aspect, please refer to Figures 4 and 5. An embodiment of the present application provides a battery cell 600, which includes a shell 10, an end cover 50 and an electrode assembly 20 in any of the aforementioned embodiments. The electrode assembly 20 is accommodated in the shell 10, and the end cover 50 is welded to the second plate portion 132, the first side plate 11 and the second side plate 12.

[0264] It should be noted that the battery cell 600 provided in the embodiment of the present application has the beneficial effects of the inner shell 10 in any of the aforementioned embodiments. Please refer to the aforementioned description of the beneficial effects of the shell 10 for details, and the embodiment of the present application does not limit this.

[0265] In some embodiments, referring to Figures 4, 11, and 19, the battery cell 600 further includes an insulation assembly J, which is disposed outside the electrode assembly 20 and insulates the electrode assembly 20 from the housing 10. The first side plate 11 includes a third plate portion 111 and a fourth plate portion 112. In the first direction X, the fourth plate portion 112 is located on the side of the third plate portion 111 that is closer to the housing opening K1. The inner surface of the third plate portion 111 is recessed relative to the inner surface of the fourth plate portion 112 to form an escape space A1. The insulation assembly J is at least partially located within the escape space A1.

[0266] The electrode assembly 20 is the core component that enables the charge and discharge functions of the battery cell 600. It may include two electrode sheets with opposite polarity and a separator located between the two electrode sheets. The separator is used to insulate the two electrode sheets. The electrode assembly 20 primarily operates by the movement of metal ions between the two electrode sheets. The electrode assembly 20 can have various forms, optionally including a wound structure, a laminated structure, or other structures. There can be one or more electrode assemblies 20.

[0267] The housing 10 is a hollow structure used to accommodate components such as the electrode assembly 20 and the first insulating member 30. The insulating member J can be located between the electrode assembly 20 and the housing 10, and the insulating member J30 is used to insulate the housing 10 from the electrode assembly 20. The insulating member J can have various shapes and structures. For example, the insulating member J can include a plate-like structure and be positioned between the electrode assembly 20 and the housing 10. Alternatively, the insulating member J can include a hollow structure with an opening, which is positioned to surround the electrode assembly 20.

[0268] Furthermore, in the embodiment of the present application, the insulating assembly J is at least partially disposed in the avoidance space A1, so that there is more space inside the shell 10 for accommodating the electrode assembly 20, thereby improving the energy density of the battery cell 600.

[0269] In some embodiments, the insulating component J includes a first insulating member 30 and a second insulating member 40, the second insulating member 40 is enclosed to form a hollow structure for accommodating the electrode assembly 20 and having an opening, the first insulating member 30 is located on the side of the second insulating member 40 away from the electrode assembly 20, and the first insulating member 30 is at least partially located in the avoidance space A1.

[0270] The insulating component J includes at least a first insulating member 30 and a second insulating member 40. The first insulating member 30 and the second insulating member 40 are both used to insulate and separate the electrode assembly 20 from the shell 10. The second insulating member 40 encloses a hollow structure that accommodates the electrode assembly 20 and has an opening. Optionally, the contour shape formed by the second insulating member 40 can be the same as the contour shape of the electrode assembly 20, and the second insulating member 40 can be fitted with the electrode assembly 20. The presence of the second insulating member 40 can further improve the insulation reliability between the electrode assembly 20 and the shell 10.

[0271] Furthermore, in the embodiment of the present application, at least a portion of the first insulating member 30 is disposed in the avoidance space A1, thereby reducing the occupation of other space inside the shell 10 by the first insulating member 30, so that there is more space inside the shell 10 for accommodating the electrode assembly 20, thereby improving the energy density of the battery cell 600.

[0272] In some embodiments, the second insulating member 40 surrounds and connects to form an overlapping region C, and the first insulating member 30 is fixed to the overlapping region C.

[0273] As can be seen from the foregoing, the second insulating member 40 is a hollow structure with an opening. During the formation of the second insulating member 40, insulating films are typically formed end-to-end to enclose the hollow structure. This results in an area of ​​overlapping insulating films on the second insulating member 40, namely, an overlap region C. This overlap region C has a greater thickness than other locations on the second insulating member 40.

[0274] On this basis, the present embodiment secures the first insulating member 30 to the overlapping region C, thereby reducing the risk of damage or cracking of the second insulating member 40 caused by the securing of the first insulating member 30 to the second insulating member 40 and improving the structural reliability of the second insulating member 40. Furthermore, the placement of the first insulating member 30 in the overlapping region C also helps reduce the risk of the second insulating member 40 unraveling in the overlapping region C, further improving the reliability of the second insulating member 40.

[0275] In some embodiments, the second insulating member 40 is partially located in the avoidance space A1 .

[0276] In the embodiment of the present application, at least part of the structure of the first insulating member 30 and part of the second insulating member 40 are arranged in the avoidance space A1, thereby further allowing more space inside the shell 10 to accommodate the electrode assembly 20, thereby improving the energy density of the battery cell 600.

[0277] In some embodiments, a portion of the electrode assembly 20 is located in the avoidance space A1.

[0278] In this embodiment of the present application, by controlling the recessed dimension of the third plate portion 111 relative to the fourth plate portion 112, a portion of the electrode assembly 20, in addition to the first insulating member 30 and the second insulating member 40, can be positioned within the avoidance space A1. This allows the size of the electrode assembly 20 within the housing 10 to be increased without changing the overall size of the battery cell 600, thereby increasing the energy density and capacity of the battery cell 600.

[0279] In some embodiments, as shown in FIG11 , the first side plate 11 further includes a first transition portion 113. The first transition portion 113 is located between the third plate portion 111 and the fourth plate portion 112. The fourth plate portion 112 is located on the side of the third plate portion 111 that is closest to the housing opening K1. In the first direction X, the thickness of the first transition portion 113 gradually increases from the third plate portion 111 toward the fourth plate portion 112. The electrode assembly 20 includes a main body 21 and a tab 22 connected to the main body 21. The main body 21 is located on the side of the first transition portion 113 that is away from the housing opening K1.

[0280] The first transition portion 113 is located between the third plate portion 111 and the fourth plate portion 112 and is used to connect the third plate portion 111 and the fourth plate portion 112. Optionally, the thickness of the first transition portion 113 may gradually increase in the direction from the third plate portion 111 to the fourth plate portion 112.

[0281] The electrode assembly 20 includes a main body 21 and a tab 22 . The main body 21 is the electricity generating part of the electrode assembly 20 . Active material is provided on the main body 21 . The tab 22 is led out from the end of the main body 21 and is used to conduct the electricity generated by the main body 21 .

[0282] Optionally, the main body 21 may include a positive electrode current collector, a positive electrode active material layer, a negative electrode current collector, a negative electrode active material layer, and a separator, and the tabs 22 may include a positive electrode tab 22 and a negative electrode tab 22 .

[0283] Furthermore, in the embodiment of the present application, by arranging the main body 21 on the side of the first transition portion 113 away from the shell opening K1, part of the structure in the main body 21 can be more easily accommodated in the avoidance space A1, thereby improving the energy density of the battery cell 600, and at the same time reducing the risk of the sharp angle formed by the first transition portion 113 puncturing the main body 21, thereby improving the reliability of the main body 21.

[0284] In some embodiments, in the first direction X, the projection of the main body 21 overlaps with the projection of the fourth plate portion 112 ; in the thickness direction of the first side plate 11 , the projection of the first transition portion 113 does not overlap with the projection of the main body 21 .

[0285] In the embodiment of the present application, the projection of the main body 21 and the projection of the fourth plate portion 112 are arranged to overlap in the first direction X, so that the main body 21 is partially located within the avoidance space A1, thereby improving the energy density of the battery cell 600. At the same time, in the thickness direction of the first side plate 11, the projection of the first transition portion 113 is arranged to not overlap with the projection of the main body 21, thereby reducing the risk of the sharp angle formed by the first transition portion 113 puncturing the main body 21 and improving the reliability of the main body 21.

[0286] In some embodiments, in the thickness direction of the second side plate 12 , the projection of the fourth transition portion 123 does not overlap with the projection of the main body 21 , so as to reduce the impact of the fourth transition portion 123 on the main body 21 .

[0287] Optionally, in the first direction X, the projection of the main body 21 overlaps with the projection of the sixth plate 122 , that is, the main body 21 is accommodated in the recessed space A4 formed by the fifth plate 121 and the sixth plate 122 , thereby improving the energy density of the battery cell 600 .

[0288] It should be noted that, with reference to FIG. 21 , the spacing dimension T between the surface of the main body 21 facing the housing opening K1 and the junction between the first transition portion 113 and the third plate portion 111 in the first direction X can have various forms, wherein T must satisfy the following requirement: T ≥ 0 mm. Optionally, T can be equal to 0 mm, i.e., the surface of the main body 21 facing the housing opening K1 and the junction between the first transition portion 113 and the third plate portion 111 are at the same height in the first direction X. Alternatively, as shown in the figure, T can be greater than 0 mm. For example, T can be 1 mm, 5 mm, 8 mm, 10 mm, etc.

[0289] In some embodiments, as shown in Figures 10 and 11, the housing 10 includes two first side plates 11 disposed opposite each other along a third direction Z. The spacing between the fourth plate portions 112 of the two first side plates 11 in the third direction Z is D1. The dimension of the electrode assembly 20 in the third direction Z is D2. Within the same first side plate 11, the spacing between the inner surface of the third plate portion 111 and the inner surface of the fourth plate portion 112 in the third direction Z is D3. D1, D2, and D3 satisfy the following relationship: 2mm-2*D3≤D1-D2≤22mm. That is, 2mm-2*D3+D2≤D1≤22mm+D2.

[0290] It should be noted that the dimension D2 of the electrode assembly 20 in the third direction Z provided in the embodiment of the present application refers to the dimension of the electrode assembly 20 when it enters the housing 10. After the electrode assembly 20 is in operation, the dimension of the electrode assembly 20 may change to a certain extent, that is, the electrode assembly 20 may expand to a certain extent, resulting in an increase in some dimensions.

[0291] As can be seen from the foregoing, during the insertion of the electrode assembly 20 into the housing, it first enters the housing 10 from the external environment to the position corresponding to the fourth plate portion 112. During this process, the two fourth plates 112 on the two opposing first side plates 11 restrict the insertion of the electrode assembly 20 into the housing. Therefore, to ensure the proper insertion of the electrode assembly 20 and the required energy density of the battery cell 600, the present embodiment controls the spacing D1 between the two fourth plates 112 in the third direction Z.

[0292] Specifically, the dimension of the electrode assembly 20 in the third direction Z is D2. Within the same first side plate 11, the distance between the inner surface of the third plate portion 111 and the inner surface of the fourth plate portion 112 in the third direction Z is D3. When the outer surface of the third plate portion 111 is flush with the outer surface of the fourth plate portion 112, D3 can be the difference between the thickness of the third plate portion 111 and the thickness of the fourth plate portion 112.

[0293] Furthermore, if D1 is less than 2mm-2*D3, during the process of the electrode assembly 20 being inserted into the shell, the distance between the electrode assembly 20 and the fourth plate portion 112 is too close, which makes it difficult for the electrode assembly 20 to be inserted into the shell. In addition, during the use of the battery cell 600, the tearing force generated by the expansion of the electrode assembly 20 on the fourth plate portion 112 increases, the electrode assembly 20 is squeezed to a large extent, and the battery cell 600 is prone to the risk of failure and explosion.

[0294] If D1 is greater than 22 mm + D2 , the distance between the electrode assembly 20 and the first side plate 11 in the formed battery cell 600 is too large, resulting in unused excess space in the battery cell 600 , which is not conducive to the energy density of the battery cell 600 .

[0295] In view of this, the embodiment of the present application sets D1, D2 and D3 to: 2mm-2*D3≤D1-D2≤22mm, thereby meeting the requirements of housing the electrode assembly 20 while improving the energy density of the battery cell 600, which has strong practicality.

[0296] In some embodiments, 2mm-2*D3≤D1-D2≤10mm. Optionally, the value of D1-D2 is one of 2mm-2*D3, 2mm, 3mm, 5mm, 7mm and 10mm.

[0297] In this embodiment of the present application, by further defining the gap dimension D1-D2 between the electrode assembly 20 and the third plate portion 111, the spacing between the electrode assembly 20 and the first side plate 11 can be further reduced, further increasing the energy density of the battery cell 600 and improving practicality. Optionally, 2mm-2*D3≤D1-D2≤6mm. For example, the value of D1-D2 is one of 2mm-2*D3, 2mm, 3mm, 5mm, and 6mm.

[0298] In some embodiments, the housing 10 includes two first side plates 11 disposed opposite each other along the second direction Y. The electrode assembly 20 has a dimension D2 in the third direction Z, the housing 10 has a dimension D4 in the third direction Z, and the fourth plate portion 112 has a dimension H2 in the third direction Z. Within the same first side plate 11, the inner surface of the third plate portion 111 is spaced apart from the inner surface of the fourth plate portion 112 in the second direction Y by a distance D3. D2, D3, D4, and H2 satisfy the following: D4 - 2*H2 - 22 mm ≤ D2 ≤ D4 - 2*H2 - (1.5 - 2*D3) - 0.2 mm.

[0299] In the formula, D4-2*H2 refers to the spacing between the two fourth plate portions 112. Experimental results show that if D2 is less than D4-2*H2-22mm, the electrode assembly 20 will be spaced a large distance from the first side plate 11 in the battery cell 600, which is detrimental to the energy density of the battery cell 600. If D2 is greater than D4-2*H2-(1.5-2*D3)-0.2mm, the distance between the electrode assembly 20 and the first side plate 11 is too close, which is detrimental to the insertion process of the electrode assembly 20 into the battery cell 600. Furthermore, during use of the battery cell 600, even a slight expansion of the electrode assembly 20 may cause contact with the first side plate 11, causing deformation of the first side plate 11 and potentially leading to failure of the battery cell 600.

[0300] In view of this, the embodiment of the present application sets D2 to be no less than D4-2*H2-22mm to ensure that the battery cell 600 can have a certain energy density and meet the capacity requirements of the battery cell 600. At the same time, D2 is set to be no greater than D4-2*H2-(1.5-2*D3)-0.2mm. This ensures that the electrode assembly 20 can be separated from the first side plate 11 by a certain distance during the use of the battery cell 600, thereby meeting the expansion requirements of the electrode assembly 20 and improving the reliability of the battery cell 600.

[0301] In some embodiments, as shown in FIG11 , the battery cell 600 further includes a second insulating member 40 . The second insulating member 40 encloses and forms a hollow structure with an opening for accommodating the electrode assembly 20 . The electrode assembly 20 includes a main body 21 and a tab 22 connected to the main body 21 . The second insulating member 40 extends beyond the main body 21 by a dimension L1 in the first direction X, where L1 satisfies the following conditions: 1 mm ≤ L1 ≤ 10 mm. Optionally, L1 is one of 1 mm, 2 mm, 4 mm, 5 mm, 7 mm, and 10 mm.

[0302] The second insulating member 40 is used to block electrical conduction and friction between the electrode assembly 20 and the housing 10. Furthermore, in the embodiment of the present application, the second insulating member 40 is disposed beyond the main body 21 in the first direction X to enhance the insulating effect of the second insulating member 40 on the electrode assembly 20. Furthermore, in the embodiment of the present application, the dimension L1 of the second insulating member 40 extending beyond the main body 21 in the first direction X is set to be no less than 1 mm to ensure the insulating and protective effect of the second insulating member 40 on the main body 21. Furthermore, the dimension L1 of the second insulating member 40 extending beyond the main body 21 in the first direction X is set to be no greater than 10 mm to reduce the possibility of the second insulating member 40 occupying excessive space within the battery cell 600 due to an oversized second insulating member 40, thereby enhancing the energy density of the battery cell 600.

[0303] In some embodiments, the second insulating member 40 faces the housing opening K1 and is spaced L2 from the housing opening K1 in the first direction X, where L2 satisfies: 1 mm ≤ L2 ≤ 10 mm. Optionally, L2 is one of 1 mm, 2 mm, 4 mm, 5 mm, 7 mm, and 10 mm.

[0304] During the battery cell 600 manufacturing process, the second insulating member 40 is typically welded to an insulating structure such as the lower plastic. Positioning the second insulating member 40 too far from the housing opening K1 can easily lead to welding problems. Positioning the second insulating member 40 too close to the housing opening K1 can also significantly increase the internal space of the housing 10, negatively impacting the energy density of the battery cell 600.

[0305] In view of this, the embodiment of the present application sets L2 to be no less than 1 mm, thereby helping to improve the welding strength between the second insulating member 40 and the lower plastic and other insulating structures, thereby improving reliability. L2 is also set to be no greater than 10 mm, thereby reducing the space occupied by the second insulating member 40 within the housing 10, thereby helping to increase the energy density of the battery cell 600.

[0306] In some embodiments, as shown in FIG10 , the housing 10 further includes a bottom plate 14 disposed opposite the housing opening K1 . The bottom plate 14 has a maximum thickness W3 , where W3 satisfies the following relationship: 0.7 mm ≤ W3 ≤ 5 mm. Optionally, the value of W3 is one of 0.7 mm, 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm.

[0307] The bottom plate 14 is arranged opposite to the shell opening K1. Optionally, the first side plate 11 and the second side plate 12 are arranged around the circumference of the bottom plate 14. In the related art, the maximum thickness of the bottom plate 14 is usually greater than 7 mm, or even greater than 10 mm. In the embodiment of the present application, in order to provide more space in the shell 10 for arranging the electrode assembly 20, the embodiment of the present application reduces the maximum thickness of the bottom plate 14 so that W3 is not greater than 5 mm, thereby providing more space for the electrode assembly 20 and improving the energy density of the battery cell 600. Furthermore, the embodiment of the present application also sets W3 to be not less than 0.7 mm to ensure that the bottom plate 14 has a certain structural strength, reduce the risk of cracking of the bottom plate 14, and improve reliability.

[0308] In some embodiments, the thickness of the second plate portion 132 is smaller than the thickness of the bottom plate 14 .

[0309] In this embodiment of the present application, to ensure the reliability of the manufacturing of the housing 10 and its ability to withstand stress, the maximum thickness of the bottom plate 14 is set to be greater than the maximum thickness of the second plate portion 132. This provides a certain structural strength for the bottom plate 14, reduces the risk of cracking, and improves reliability. Furthermore, optionally, the maximum thickness of the bottom plate 14 is greater than the maximum thickness of the fourth plate portion 112; and / or the maximum thickness of the bottom plate 14 is greater than the maximum thickness of the sixth plate portion 122.

[0310] In some embodiments, the first side panel 11 includes a third panel portion 111 and a fourth panel portion 112. In the first direction X, the fourth panel portion 112 is located on the side of the third panel portion 111 closest to the housing opening K1. The second side panel 12 includes a fifth panel portion 121 and a sixth panel portion 122. In the first direction X, the sixth panel portion 122 is located on the side of the fifth panel portion 121 closest to the housing opening K1. The sixth panel portion 122 is provided with a first recess A2 that extends inward from the housing opening K1. The end cap 50 is partially located within the first recess A2 and is connected to the sixth panel portion 122 and the fourth panel portion 112.

[0311] In an embodiment of the present application, the end cover 50 can be partially located in the first recess A2, so that the relative position of the end cover 50 can be determined with the help of the first recess A2. On this basis, the end cover 50 can also be connected and fixed to the sixth plate portion 122 and the fourth plate portion 112 by welding, so as to improve the reliability of the relative position between the end cover 50 and the shell 10.

[0312] In a second aspect, an embodiment of the present application provides a battery, comprising the battery cell 600 in any of the aforementioned embodiments.

[0313] It should be noted that the battery provided in the embodiment of the present application has the beneficial effects of the battery cell 600 in any of the aforementioned embodiments. For details, please refer to the aforementioned description of the beneficial effects of the battery cell 600, which will not be repeated in the embodiment of the present application.

[0314] In some embodiments, referring to Figures 7 and 20 , a battery includes a battery cell group and an end plate 60 . The battery cell group includes a plurality of battery cells 600 stacked along a third direction Z. The first side plate 11 includes a third plate portion 111 and a fourth plate portion 112 . In the first direction X, the fourth plate portion 112 is located on a side of the third plate portion 111 that is closer to the housing opening K1 . The maximum thickness of the fourth plate portion 112 is greater than the maximum thickness of the third plate portion 111 . The third direction Z is parallel to the thickness direction of the first side plate 11 and intersects the first direction X. Along the third direction Z, the end plate 60 is disposed at an end of the battery cell group. In the direction from the third plate portion 111 to the fourth plate portion 112 , the fourth plate portion 112 at least partially extends beyond the end plate 60 .

[0315] The battery cell group includes a plurality of battery cells 600, which are arranged side by side in a third direction Z. An end plate 60 is disposed on at least one side of the plurality of battery cells 600 along the third direction Z. The number of end plates 60 may be one or two. If there are two end plates 60, the two end plates 60 may be located on both sides of the battery cell group along the third direction Z.

[0316] The first side plate 11 includes a third plate portion 111 and a fourth plate portion 112 . The fourth plate portion 112 is thicker than the third plate portion 111 , so the strength of the fourth plate portion 112 is generally greater than that of the third plate portion 111 .

[0317] In the embodiment of the present application, along the direction from the third plate portion 111 to the fourth plate portion 112, the fourth plate portion 112 is arranged beyond the end plate 60. In the direction from the third plate portion 111 to the fourth plate portion 112, the fourth plate portion 112 may be arranged entirely beyond the end plate 60, or the fourth plate portion 112 may be arranged only partially beyond the end plate 60. At least the portion of the structure where the fourth plate portion 112 exceeds the end plate 60 will not be constrained by the end plate 60. On this basis, by setting the thickness of the fourth plate portion 112 to be greater than the thickness of the third plate portion 111, it helps to improve the strength of the portion of the structure not constrained by the end plate 60, thereby improving the risk of cracking due to being constrained by the end plate 60 and improving the reliability of the battery.

[0318] In the third aspect, referring to FIG. 5 to FIG. 13 , FIG. 15 and FIG. 16 , an embodiment of the present application provides an electrical device, comprising a battery cell 600 in any of the aforementioned embodiments, and the battery cell 600 is used to provide electrical energy.

[0319] According to some embodiments of the present application, a battery cell 600 includes a housing 10, an electrode assembly 20, a first insulating member 30, and a second insulating member 40. The electrode assembly 20, the first insulating member 30, and the second insulating member 40 are all housed within the housing 10. The housing 10 has a housing opening K1 at an end thereof along a first direction X. The housing 10 includes a first side plate 11, a second side plate 12, and a connecting plate 13. The first side plate 11 and the second side plate 12 are arranged circumferentially around the housing opening K1. The connecting plate 13 is connected to the first side plate 11 and the second side plate 12, and at least a portion of an outer surface of the connecting plate 13 includes a curved surface.

[0320] The first side plate 11 includes a third plate portion 111, a fourth plate portion 112 and a first transition portion 113 located between the third plate portion 111 and the fourth plate portion 112. The fourth plate portion 112 is located on the side of the third plate portion 111 close to the shell opening K1. The outer surfaces of the third plate portion 111 and the fourth plate portion 112 are flush. The inner surface of the third plate portion 111 is concave relative to the inner surface of the fourth plate portion 112 to form an avoidance space A1 on the first side plate 11. The first insulating member 30, the second insulating member 40 and the electrode assembly 20 are at least partially located in the avoidance space A1.

[0321] The thickness of the first transition portion 113 gradually increases from the third plate portion 111 to the fourth plate portion 112. The first transition portion 113 includes a first transition surface M1 facing the interior of the housing 10. The angle α between the first transition surface M1 and the first direction X satisfies: 0<α≤60°.

[0322] The connecting plate 13 includes a first plate portion 131 and a second plate portion 132. The second plate portion 132 is located on the side of the first plate portion 131 closest to the housing opening K1. The thickness of the second plate portion 132 is greater than that of the first plate portion 131 and less than that of the fourth plate portion 112. The angle β between the inner surface of the second plate portion 132 and the inner surface of the fourth plate portion 112 satisfies the following conditions: 155° ≤ β ≤ 270°. The second plate portion 132 includes a plate body 1321 and a second transition portion 1322 connecting the plate body 13 and the fourth plate portion 112. The thickness of the second transition portion 1322 decreases gradually along the direction from the fourth plate portion 112 to the plate body 1321.

[0323] The second side plate 12 includes a fifth plate portion 121 and a sixth plate portion 122. The sixth plate portion 122 is located on the side of the fifth plate portion 121 that is closer to the housing opening K1. The thickness of the sixth plate portion 122 is no less than that of the fifth plate portion 121. The second plate portion 132 includes a third transition portion 1323 that connects the plate body 1321 and the sixth plate portion 122. The thickness of the third transition portion 1323 gradually decreases along the direction from the sixth plate portion 122 to the plate body 1321.

[0324] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A housing of a battery cell, the housing having a housing opening at an end in a first direction, the housing comprising: a first side plate and a second side plate arranged circumferentially along the housing opening; a connecting plate connected to the first side plate and the second side plate, and at least part of an outer surface of the connecting plate includes an arc surface, the connecting plate includes a first plate portion and a second plate portion, in the first direction, the second plate portion is located on a side of the first plate portion close to the housing opening; wherein, a maximum thickness of the second plate portion is greater than or equal to a maximum thickness of the first plate portion.

2. The housing according to claim 1, wherein, the first side plate includes a third plate portion and a fourth plate portion, in the first direction, the fourth plate portion is located on a side of the third plate portion close to the housing opening; wherein, a maximum thickness of the fourth plate portion is greater than a maximum thickness of the third plate portion.

3. The housing according to claim 2, wherein, an inner surface of the third plate portion is recessed relative to an inner surface of the fourth plate portion; and / or, an inner surface of the first plate portion is recessed relative to an inner surface of the second plate portion.

4. The housing according to claim 3, wherein, an outer surface of the third plate portion is flush with an outer surface of the fourth plate portion; and / or, an outer surface of the first plate portion is flush with an outer surface of the second plate portion.

5. The housing according to any one of claims 2 to 4, wherein, a maximum thickness of the third plate portion is H1, a maximum thickness of the fourth plate portion is H2, H1 and H2 satisfy: 0.05 mm ≤ H2 - H1 ≤ 0.3 mm.

6. The housing according to any one of claims 2 to 5, wherein, the first side plate further includes a first transition portion, the first transition portion is located between the third plate portion and the fourth plate portion; in the first direction and in a direction pointing from the third plate portion to the fourth plate portion, a thickness of the first transition portion gradually increases.

7. The housing according to claim 6, wherein, the first transition portion includes a first transition surface facing the inside of the housing, an angle between the first transition surface and the first direction is α, α satisfies: 0 < α ≤ 60°.

8. The housing according to any one of claims 2 to 7, wherein, a maximum thickness of the second plate portion is H3, a maximum thickness of the fourth plate portion is H2, H2 and H3 satisfy: 0.1 mm ≤ H3 ≤ 0.8H2.

9. The housing according to any one of claims 2 to 8, wherein, a maximum thickness of the second plate portion is not greater than a maximum thickness of the fourth plate portion; and / or, a difference between maximum thicknesses corresponding to the second plate portion and the first plate portion is not greater than a difference between maximum thicknesses corresponding to the fourth plate portion and the third plate portion.

10. The housing according to claim 9, wherein, two of the second side plates are oppositely arranged in a second direction, the first direction intersects with the second direction; the fourth plate portion includes a central portion and an edge portion located on at least one side of the central portion in the second direction, the edge portion is connected to the second plate portion, and a maximum thickness of the edge portion is less than a maximum thickness of the central portion.

11. The housing according to claim 10, wherein, the size of the central portion in the second direction is Z1, the size of the housing in the second direction is Z2, and Z1 and Z2 satisfy: 0.5 ≤ Z1 / Z2.

12. The housing according to any one of claims 2 to 11, wherein, the included angle between the inner surface of the fourth plate portion and the inner surface of the second plate portion is β, and β satisfies: 155° ≤ β ≤ 270°.

13. The housing according to any one of claims 2 to 12, wherein, the second plate portion includes a plate main body and a second transition portion connecting the plate main body and the fourth plate portion, and the maximum thickness of the plate main body is less than the minimum thickness of the second transition portion; in the direction gradually approaching the fourth plate portion, the thickness of the second transition portion shows a gradually increasing trend.

14. The housing according to claim 13, wherein, the two second side plates are oppositely arranged in the second direction, and the first direction intersects with the second direction; the size of the second transition portion in the second direction is L1, and L1 satisfies: 1 mm ≤ L1 ≤ 15 mm.

15. The housing according to claim 13 or 14, wherein, the inner surface of the second transition portion includes an arc surface structure; and / or. the inner surface of the second transition portion includes a flat surface structure.

16. The housing according to any one of claims 1 to 15, wherein, the maximum thickness of the second plate portion is greater than the maximum thickness of the first plate portion, the connecting plate further includes a fifth transition portion, and the fifth transition portion is located between the first plate portion and the second plate portion; in the first direction and in the direction pointing from the first plate portion to the second plate portion, the thickness of the fifth transition portion gradually increases.

17. The housing according to any one of claims 1 to 16, wherein, the second side plate includes a fifth plate portion and a sixth plate portion, and in the first direction, the sixth plate portion is located on the side of the fifth plate portion close to the opening of the housing; the sixth plate portion is provided with a first recess formed by recessing inward from the opening of the housing, and the first recess is used to receive the end cover of the battery cell.

18. The housing according to claim 17, wherein, the thickness of the sixth plate portion at the position of the first recess is not less than the maximum thickness of the fifth plate portion.

19. The housing according to claim 17 or 18, wherein, the first side plate includes a third plate portion and a fourth plate portion, and in the first direction, the fourth plate portion is located on the side of the third plate portion close to the opening of the housing; in the first direction, the size of the sixth plate portion is greater than or equal to the size of the fourth plate portion.

20. The housing according to any one of claims 17 to 19, wherein, the second plate portion is provided with a second recess formed by recessing inward from the opening of the housing, and the first recess and the second recess are communicated with each other.

21. The housing according to claim 20, wherein, the thickness of the second plate portion at the position of the second recess is not less than the maximum thickness of the first plate portion.

22. The housing according to any one of claims 1 to 21, wherein, The second side plate includes a fifth plate portion and a sixth plate portion, and in the first direction, the sixth plate portion is located on a side of the fifth plate portion close to the shell opening; The maximum thickness of the sixth plate portion is greater than the maximum thickness of the fifth plate portion.

23. The housing according to claim 22, in, The second side plate further includes a fourth transition portion, the fourth transition portion being located between the fifth plate portion and the sixth plate portion; In the first direction and in the direction from the fifth plate portion to the sixth plate portion, the thickness of the fourth transition portion gradually increases; and / or, The fifth plate portion is flush with an outer surface of the sixth plate portion.

24. A housing according to any one of claims 17 to 23, in, The two first side plates are arranged opposite to each other in the third direction, the two second side plates are arranged opposite to each other in the second direction, and the first direction, the second direction and the third direction intersect each other; A dimension of the first side plate in the second direction is greater than a dimension of the second side plate in the third direction.

25. A housing according to any one of claims 1 to 24, in, The first side plate includes a third plate portion arranged corresponding to the first plate portion in the circumferential direction of the shell, and the second side plate includes a fifth plate portion arranged corresponding to the first plate portion in the circumferential direction of the shell; the first plate portion is connected to the third plate portion and the fifth plate portion, and the inner surfaces of the first plate portion, the third plate portion and the fifth plate portion are smoothly transitioned.

26. A battery cell, include: A housing as claimed in any one of claims 1 to 25; an electrode assembly, contained in the housing; An end cover is welded to the second plate portion, the first side plate and the second side plate.

27. The battery cell according to claim 26, further comprising an insulating component, the insulating component being disposed outside the electrode assembly and insulating the electrode assembly from the housing; The first side plate includes a third plate portion and a fourth plate portion, wherein in the first direction, the fourth plate portion is located on a side of the third plate portion close to the shell opening, and an inner surface of the third plate portion is concave relative to an inner surface of the fourth plate portion to form an escape space; The insulating component is at least partially located in the avoidance space.

28. The battery cell according to claim 27, in, The insulating assembly comprises a first insulating member and a second insulating member, wherein the second insulating member is enclosed to form a hollow structure having an opening for accommodating the electrode assembly; the first insulating member is located on a side of the second insulating member away from the electrode assembly; The first insulating member is at least partially located in the escape space.

29. The battery cell according to claim 28, in, The second insulating members are surrounded and connected to form an overlapping area, and the first insulating member is fixed to the overlapping area.

30. The battery cell according to claim 28 or 29, in, The second insulating member is partially located in the escape space.

31. The battery cell according to any one of claims 26 to 30, in, The first side plate includes a third plate portion and a fourth plate portion, wherein in the first direction, the fourth plate portion is located on a side of the third plate portion close to the shell opening, and an inner surface of the third plate portion is concave relative to an inner surface of the fourth plate portion to form an escape space; The electrode assembly is partially located in the avoidance space.

32. The battery cell according to any one of claims 26 to 31, in, The first side plate includes a third plate portion, a fourth plate portion, and a first transition portion connecting the third plate portion and the fourth plate portion, wherein in the first direction, the fourth plate portion is located at a side of the third plate portion close to the shell opening, and in the first direction and in a direction from the third plate portion to the fourth plate portion, a thickness of the first transition portion gradually increases; The electrode assembly includes a main body and a pole ear connected to the main body, and the main body is located on a side of the first transition portion away from the shell opening.

33. The battery cell according to claim 32, in, In the first direction, the projection of the main body portion and the projection of the fourth plate portion are arranged to overlap; In the thickness direction of the first side plate, a projection of the first transition portion does not overlap with a projection of the main body portion.

34. The battery cell according to any one of claims 26 to 33, in, The battery cell further includes a second insulating member, the second insulating member enclosing and forming a hollow structure for accommodating the electrode assembly and having an opening; The electrode assembly includes a main body and a tab connected to the main body. The second insulating member exceeds the main body by a dimension L1 in the first direction, and L1 satisfies: 1 mm ≤ L1 ≤ 10 mm.

35. The battery cell according to claim 34, in, The second insulating member faces the shell opening, and the distance between the second insulating member and the shell opening in the first direction is L2, and L2 satisfies: 1mm≤L2≤10mm.

36. The battery cell according to any one of claims 26 to 35, in, The shell further includes a bottom plate arranged opposite to the shell opening, and the maximum thickness of the bottom plate is W3, and W3 satisfies: 0.7 mm ≤ W3 ≤ 5 mm.

37. The battery cell according to claim 36, in, The maximum thickness of the second plate portion is smaller than the maximum thickness of the bottom plate.

38. The battery cell according to any one of claims 26 to 37, in, The first side plate includes a third plate portion and a fourth plate portion, and in the first direction, the fourth plate portion is located on a side of the third plate portion close to the shell opening; The second side plate includes a fifth plate portion and a sixth plate portion, wherein in the first direction, the sixth plate portion is located on a side of the fifth plate portion close to the shell opening, and the sixth plate portion is provided with a first recessed portion formed inwardly from the shell opening; The end cover portion is located in the first recess and is connected to the sixth plate portion and the fourth plate portion.

39. A battery comprising the battery cell according to any one of claims 26 to 38.

40. The battery according to claim 39, wherein the battery include: The battery cell group includes a plurality of battery cells stacked in the third direction. The first side plate includes a third plate portion and a fourth plate portion. In the first direction, the fourth plate portion is located on the side of the third plate portion closer to the opening of the housing. The maximum thickness of the fourth plate portion is greater than the maximum thickness of the third plate portion. The third direction is parallel to the thickness direction of the first side plate and intersects the first direction. The end plate is disposed at the end of the battery cell group along the third direction. Wherein, along the direction from the third plate portion to the fourth plate portion, at least a part of the fourth plate portion exceeds the end plate.

41. An electrical device, comprising the battery cell according to any one of claims 26 to 38, wherein the battery cell is used to provide electrical energy.

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