Battery cell, battery device, and electric device

Abstract

This application provides a battery cell, a battery device, and an electrical device. The battery cell includes a housing, an end cap, and an electrode assembly. The housing has an opening at one end along a first direction, and the end cap closes to the opening. The electrode assembly is housed within the housing. The housing includes at least two first walls disposed opposite each other along the thickness direction of the electrode assembly. A first recess is provided at the end of the first wall near the end cap along the first direction. The first recess extends through the first wall along the thickness direction, which is perpendicular to the thickness direction. Each first wall includes a main body and a first thickened portion. The first thickened portion is connected to the main body, and its dimension along the thickness direction is larger than that of the main body. Along the first direction, at least a portion of the first thickened portion is located on the side of the first recess away from the end cap. The end cap is welded to the first thickened portion. This application can effectively improve the reliability of the battery cell.

Description

Technical Field

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

[0002] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] In the development of battery technology, improving the reliability of individual battery cells is a continuous research direction. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an end cap, and an electrode assembly. The housing has an opening at one end along a first direction, and the end cap closes to the opening. The electrode assembly is housed within the housing. The housing includes at least two first walls disposed opposite each other along the thickness direction of the electrode assembly. A first recess is provided at the end of the first wall near the end cap along the first direction. The first recess extends through the first wall along the thickness direction, which is perpendicular to the thickness direction. Each first wall includes a main body and a first thickened portion. The first thickened portion is connected to the main body, and its dimension along the thickness direction is larger than that of the main body along the thickness direction. Along the first direction, at least a portion of the first thickened portion is located on the side of the first recess away from the end cap, and the end cap is welded to the first thickened portion.

[0006] The above technical solution improves the structural strength of the first wall in the area near the first recess by providing a first thickened portion on the side of the first recess away from the end cap along the first direction, thereby reducing the risk of cracking of the first wall and improving the reliability of the battery cell.

[0007] In some embodiments of the first aspect, the first wall includes a first end face for defining the first recess, and the first thickened portion includes at least a portion of the first end face.

[0008] The above technical solution makes it easier to weld the end cap to the first thickened part, reducing the difficulty of manufacturing the battery cell.

[0009] In some embodiments of the first aspect, the first thickened portion includes the entire first end face to further enhance the structural strength of the first wall in the region near the first recess.

[0010] In some embodiments of the first aspect, the first wall includes a first end face for defining a first recess, the first end face including a bottom surface and two side surfaces, the two side surfaces being respectively connected to the two ends of the bottom surface along a second direction, the first direction, the second direction and the thickness direction being perpendicular to each other.

[0011] The first thickened portion includes at least a portion of the bottom surface, or at least a portion of the first thickened portion is located on the side of the bottom surface away from the end cap along a first direction.

[0012] The above technical solution can effectively reduce the risk of cracking of the first wall by thickening the area near the bottom surface.

[0013] In some embodiments of the first aspect, a portion of the first thickened portion includes at least a portion of the side surface, or a portion of the first thickened portion is located along the second direction on the side surface away from the end cap.

[0014] The above technical solution can further enhance the overall structural strength of the first wall by thickening the area near the side.

[0015] In some embodiments of the first aspect, the projection of the first thickened portion along the first direction coincides with the projection of the bottom surface along the first direction.

[0016] The above technical solution, by thickening only the area near the bottom surface, can reduce the risk of cracking of the first wall while reducing the volume of the thickened part to a certain extent, thereby further reducing the weight of the casing and increasing the energy density of the battery cell.

[0017] In some embodiments of the first aspect, the first thickened portion includes a first part and two second parts, the two second parts being respectively connected to the two ends of the first part along the second direction, the maximum dimension of the second part along the thickness direction being smaller than the maximum dimension of the first part along the thickness direction, and the first direction, the second direction and the thickness direction being perpendicular to each other.

[0018] The above technical solution helps to make the inner shell of the mold easier to eject in the direction of the draft during the molding process, reducing the risk of jamming or sticking, while optimizing stress distribution and reducing the probability of part deformation, thereby improving production efficiency and product qualification rate.

[0019] In some embodiments of the first aspect, the second portion gradually decreases in size along the thickness direction in the direction pointing from the first portion to the second portion.

[0020] The gradual reduction in thickness in the second part of the above technical solution can effectively distribute the load, reduce local stress concentration, and decrease structural cracking and damage caused by material fatigue or external impact, significantly improving the overall durability and reliability of the structure. Furthermore, while maintaining structural strength, by rationally designing the thickness reduction area and reducing material usage, the overall weight of the battery cell can be reduced, thereby contributing to increasing the energy density of the battery cell.

[0021] In some embodiments of the first aspect, a portion of the first thickened portion protrudes from the side of the main body facing the electrode assembly in the thickness direction.

[0022] It can improve the flatness of the outer surface of the casing, thereby facilitating the assembly of battery cells and improving the appearance quality of battery cells.

[0023] In some embodiments of the first aspect, a portion of the end cap is disposed within the housing, and a groove recessed along the thickness direction is provided on the side of the end cap facing the first wall, at least a portion of the first thickened portion being accommodated in the groove.

[0024] The above technical solution reduces interference between the end cap and the first thickened part during the assembly process by setting a groove on the end cap to avoid the first thickened part, which facilitates the assembly between the end cap and the housing and thus improves the assembly efficiency of the battery cell.

[0025] In some embodiments of the first aspect, the first thickened portion abuts against the wall of the groove in a first direction.

[0026] The first thickened portion can limit the end cap along the first direction, which not only plays a certain positioning role in the assembly process of the end cap and the housing, improving assembly efficiency, but also enables the first thickened portion to provide a certain support for the end cap, improving the stability of the end cap.

[0027] In some embodiments of the first aspect, the thickness of at least a portion of the first thickened portion gradually decreases along the direction from the end cap toward the electrode assembly.

[0028] The above technical solution can reduce the risk of the electrode assembly being damaged by the compression of the first thickened section. The gradual reduction in the thickness of the first thickened section can effectively distribute the load, reduce local stress concentration, and decrease structural cracking and damage caused by material fatigue or external impact, significantly improving the overall durability and reliability of the structure. Furthermore, while maintaining structural strength, by rationally designing the thickness reduction area and reducing material usage, the overall weight of the battery cell can be reduced, thereby helping to improve the energy density of the battery cell.

[0029] In some embodiments of the first aspect, the first thickened portion includes a first segment and a second segment, the second segment being connected to the side of the first segment away from the end cap along a first direction. Along the direction from the end cap toward the electrode assembly, the thickness of the first segment remains constant, while the thickness of the second segment gradually decreases.

[0030] The above technical solution achieves a balance between the structural strength and space occupation of the first thickened part by subdividing the first thickened part into a first segment with a constant thickness and a second segment with a gradually decreasing thickness. This not only improves the reliability of the battery cell but also optimizes the internal space utilization of the battery cell, which helps to improve the energy density of the battery cell.

[0031] In some embodiments of the first aspect, the first thickened portion further includes a third segment connected to the second segment on the side away from the first segment along a first direction. The thickness of the third segment gradually decreases along the direction from the end cap to the electrode assembly, and the thickness change of the third segment per unit length in the direction from the end cap to the electrode assembly is greater than the thickness change of the second segment.

[0032] The above technical solution, by introducing a third segment and forming a multi-segment thickness-decreasing structure with the second segment, can effectively allocate the focus on the fabrication and function of the first thickened part, while also achieving a reasonable thickness gradient. On the one hand, the relatively gentle thickness reduction process of the second segment helps to reduce the fabrication difficulty of the first thickened part; on the other hand, the relatively rapid thickness reduction process of the third segment helps to meet the overall thickness reduction requirements of the first thickened part.

[0033] In some embodiments of the first aspect, the first thickened portion further includes a fourth segment connected to the third segment on the side away from the second segment along a first direction. The thickness of the fourth segment gradually decreases along the direction from the end cap to the electrode assembly, and the thickness change of the fourth segment per unit length in the direction from the end cap to the electrode assembly is less than the thickness change of the third segment.

[0034] The above technical solution can further reduce the difficulty of preparing the first thickened part by introducing a fourth segment.

[0035] In some embodiments of the first aspect, along the first direction, the entire first thickened portion is located on the side of the first recess away from the end cap.

[0036] By providing a first thickening portion only for the area near the first recess of the first wall, the structural strength of that area can be improved. This reduces the risk of cracking of the first wall and improves the reliability of the battery cell, while also reducing the amount of the first thickening portion to a certain extent, thereby increasing the energy density of the battery cell and reducing costs.

[0037] In some embodiments of the first aspect, the first wall further includes a second thickened portion, which is disposed along a second direction with the first thickened portion, and the projection of the second thickened portion along the first direction does not overlap with the projection of the first recess along the first direction, and the first direction, the second direction and the thickness direction are perpendicular to each other.

[0038] By further adding a second thickened section, the structural strength of the first wall can be further improved, the risk of cracking of the first wall can be reduced, and thus the reliability of the battery cell can be further improved.

[0039] In some embodiments of the first aspect, the first thickened portion is directly connected to the second thickened portion.

[0040] This design creates a reinforcing structure, enabling both the first and second thickened sections to work together to withstand external forces, effectively enhancing the overall structural strength of the first wall. This structural design not only optimizes the stress distribution and improves the deformation resistance of the first wall, but also facilitates the fabrication of the first and second thickened sections using an integral molding process, thereby simplifying the production process, reducing manufacturing costs, and improving production efficiency.

[0041] In some embodiments of the first aspect, along a first direction, the end of the first thickened portion away from the end cap is flush with the end of the second thickened portion away from the end cap.

[0042] The above technical solutions can further improve the reliability of battery cells and reduce costs.

[0043] In some embodiments of the first aspect, the first wall includes a first end face and a second end face, the first recess is recessed relative to the second end face, the first end face is connected to the second end face and is used to define the first recess, and the projection of the second end face along the first direction does not overlap with the projection of the first recess along the first direction.

[0044] The first thickened portion includes at least a portion of the first end face, and / or the second thickened portion includes at least a portion of the second end face.

[0045] The above technical solution can further simplify the manufacturing process of battery cells and reduce the difficulty of manufacturing battery cells.

[0046] In some embodiments of the first aspect, there are multiple first recesses, which are spaced apart along a second direction, with the first direction, the second direction, and the thickness direction being perpendicular to each other. There are also multiple first thickened portions, each corresponding to a first recess.

[0047] By setting the number of first recesses to multiple, the design flexibility of the first wall can be further improved, thereby increasing the applicability of the battery cell.

[0048] In some embodiments of the first aspect, at least a portion of the first recesses are disposed at both ends of the first wall along the second direction, wherein the first direction, the second direction, and the thickness direction are perpendicular to each other.

[0049] By providing a first recess at the end of the first wall along the second direction, the first recess is relatively far from the central region of the electrode assembly, thereby reducing the expansion force from the electrode assembly on the first wall near the first recess. This reduces the risk of cracking in the welding area between the end cap and the first wall near the first recess, and improves the reliability of the battery cell.

[0050] In some embodiments of the first aspect, the first recess is located in the middle region of the first wall along the second direction, wherein the first direction, the second direction, and the thickness direction are perpendicular to each other.

[0051] The above technical solution enables the electrode terminals to be located in the middle area of ​​the first wall, which reduces the risk of the battery cell interfering with other structures during assembly and thus damaging the electrode terminals.

[0052] In some embodiments of the first aspect, the projections of the first thickened portions of the two first walls along the thickness direction at least partially overlap.

[0053] It can form a more uniform stress support structure on the casing, reducing the risk of casing deformation due to uneven stress, thereby further improving the reliability of the battery cell.

[0054] In some embodiments of the first aspect, the dimension of the first thickened portion along the thickness direction is 0.05mm-0.5mm.

[0055] The above technical solution, by setting the thickness of the first thickened part within the above range, can reduce the risk of cracking of the first wall, improve the reliability of the battery cell, and at the same time reduce the impact on the energy density of the battery cell and reduce the manufacturing difficulty to a certain extent.

[0056] In some embodiments of the first aspect, the dimension of the first thickened portion along the thickness direction is 0.1mm-0.3mm. This can further improve the balance between the reliability, energy density, and manufacturing difficulty of the battery cell.

[0057] In some embodiments of the first aspect, the dimension of the first thickened portion along the first direction is 0.5mm-20mm.

[0058] The above technical solution, by setting the size of the first thickened portion along the first direction within the above-mentioned range, can reduce the risk of cracking of the first wall, improve the reliability of the battery cell, and at the same time reduce the impact on the energy density of the battery cell and reduce the manufacturing difficulty to a certain extent.

[0059] In some embodiments of the first aspect, the dimension of the first thickened portion along the first direction is 1mm-10mm. This can further improve the balance between the reliability, energy density, and manufacturing difficulty of the battery cell.

[0060] In some embodiments of the first aspect, the end cap includes a first cap portion and a second cap portion, wherein along a first direction, the second cap portion is closer to the electrode assembly than the first cap portion, and the second cap portion is welded to the first thickened portion.

[0061] The space formed by the height difference between the first cover and the second cover in the first direction helps to reduce the overall volume of the battery cell and increase the energy density of the battery cell.

[0062] In some embodiments of the first aspect, the battery cell further includes an electrode terminal, and the electrode assembly includes a tab, the electrode terminal being disposed on the second cover and electrically connected to the tab.

[0063] By placing the electrode terminals on the second cover, the electrode terminals can make full use of the space formed by the height difference between the first cover and the second cover in the first direction, which is beneficial to reducing the size of the battery cell and increasing the energy density of the battery cell.

[0064] In some embodiments of the first aspect, a second recess is formed on the side of the end cap facing the electrode assembly, and the second recess is disposed opposite to the first cover portion along the first direction, and at least a portion of the electrode tab is accommodated in the second recess.

[0065] The above technical solution accommodates at least a portion of the tab within the second recess, thus enabling the tab to fully utilize the space formed by the height difference between the first cover and the second cover in the first direction. This is beneficial for reducing the size of the battery cell and increasing its energy density.

[0066] In some embodiments of the first aspect, the projection of the electrode terminal along the second direction at least partially overlaps with the projection of the tab along the second direction, and the first direction, the second direction and the thickness direction are perpendicular to each other.

[0067] This allows the electrode terminals and tabs to make better use of the space formed by the height difference between the first cover and the second cover in the first direction, which is beneficial for reducing the size of the battery cell and increasing the energy density of the battery cell.

[0068] Secondly, this application provides a battery device that includes a battery cell provided in any of the embodiments of the first aspect.

[0069] Thirdly, this application provides an electrical device that includes a battery cell provided in any embodiment of the first aspect or a battery device provided in any embodiment of the second aspect, wherein the battery cell or battery device is used to store or provide electrical energy.

[0070] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0071] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0072] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application;

[0073] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application;

[0074] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0075] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in some embodiments of this application;

[0076] Figure 5 This is a three-dimensional structural diagram of a battery cell casing provided in some embodiments of this application;

[0077] Figure 6 This is a front view structural diagram of the first wall of a battery cell provided in some embodiments of this application;

[0078] Figure 7 This is a front view structural diagram of the first wall of another battery cell provided in some embodiments of this application;

[0079] Figure 8 This is a top view of the casing of a battery cell provided in some embodiments of this application;

[0080] Figure 9 for Figure 8 A magnified schematic diagram of the local structure at point F;

[0081] Figure 10 This is a three-dimensional structural diagram of the end cap of a battery cell provided in some embodiments of this application;

[0082] Figure 11 for Figure 10 A magnified schematic diagram of the local structure at point G;

[0083] Figure 12 for Figure 5 A magnified schematic diagram of the local structure at point H;

[0084] Figure 13 This is a front view structural diagram of the first wall of another battery cell provided in some embodiments of this application;

[0085] Figure 14 This is a schematic diagram of the exploded structure of another battery cell provided in some embodiments of this application.

[0086] The reference numerals in the detailed embodiments are as follows:

[0087] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 6. Battery module; 7. Battery cell;

[0088] 10. Shell; 101. Opening;

[0089] 11. First wall; 111. Main body; 112. First thickened part; 1121. First section; 1122. Second section; 1123. First segment; 1124. Second segment; 1125. Third segment; 1126. Fourth segment; 113. Second thickened part;

[0090] 114. First end face; 1141. Bottom face; 1142. Side face; 11421. Planar segment; 11422. First arc segment; 11423. Second arc segment; 115. Second end face;

[0091] 110. The first concave part;

[0092] 12. The second wall;

[0093] 20. Electrode assembly;

[0094] 30. End cap; 31. Groove; 32. First cap portion; 33. Second cap portion; 301. Second recess portion;

[0095] 40. Electrode terminals;

[0096] X, first direction; Y, second direction; Z, thickness direction. Detailed Implementation

[0097] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0098] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0099] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0100] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0101] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0102] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0103] In this application, "multiple" means two or more (including two).

[0104] In this application, the term "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0105] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0106] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0107] In the development of battery technology, improving the reliability of individual battery cells is a continuous research direction.

[0108] The battery cell includes a housing and an end cap. The housing has an opening, and the end cap closes to the opening and seals the connection to form a sealed space for accommodating the electrode assembly and electrolyte.

[0109] In related technologies, the housing and end caps are connected by welding. Welding ensures both the connection strength between the housing and end caps and achieves a seal between them.

[0110] However, after welding, a heat-affected zone (HAZ) forms near the molten pool in the casing. This HAZ is subjected to residual thermal stress, resulting in lower strength compared to other areas. When the HAZ is subjected to pressure during battery cell use, the casing may crack in the HAZ, leading to electrolyte leakage, battery cell failure, and safety risks.

[0111] Furthermore, as the demand for energy density of individual battery cells increases, some structural designs will be made to the battery cell casing. For example, a recess will be provided on the side edge of the casing near the opening to facilitate the adaptation of end caps with different structures designed to improve energy density.

[0112] The end cap is welded to the side wall of the housing. Due to the presence of the recess, along the height direction of the battery cell, the position of the side wall near the recess is closer to the central area of ​​the electrode assembly. During the cyclic expansion of the electrode assembly, the expansion amount of the electrode assembly closer to the central area will be relatively greater. This makes the welded area of ​​the end cap and the side wall near the recess more prone to deformation and cracking, affecting the reliability of the battery cell.

[0113] Based on the above considerations, this application designs a battery cell, which includes a housing, an end cap, and an electrode assembly. The housing has an opening at one end along a first direction, and the end cap closes to the opening. The electrode assembly is housed within the housing. The housing includes at least two first walls disposed opposite each other along the thickness direction of the electrode assembly. A first recess is provided at the end of the first wall near the end cap along the first direction. The first recess penetrates the first wall along the thickness direction, and the first direction is perpendicular to the thickness direction. The first wall includes a main body and a first thickened portion. The first thickened portion is connected to the main body, and its dimension along the thickness direction is larger than that of the main body along the thickness direction. Along the first direction, at least a portion of the first thickened portion is located on the side of the first recess away from the end cap, and the end cap is welded to the first thickened portion.

[0114] The above technical solution improves the structural strength of the first wall in the area near the first recess by providing a first thickened portion on the side of the first recess away from the end cap along the first direction, thereby reducing the risk of cracking of the first wall and improving the reliability of the battery cell.

[0115] The battery cells described in this application are applicable to battery devices and electrical equipment using battery devices. Electrical equipment can be devices that use battery devices as a power source or various energy storage systems that use battery devices as energy storage elements. Electrical equipment can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0116] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0117] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0118] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0119] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0120] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0121] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0122] In some embodiments, the battery device 2 may include one or more battery cell assemblies for providing voltage and capacity.

[0123] A battery cell assembly may include multiple battery cells ( Figure 2 (Not shown), multiple battery cells are connected in series, parallel, or mixed connection through a busbar. Mixed connection refers to multiple battery cells being connected in both series and parallel.

[0124] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0125] As an example, a single battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0126] As an example, a battery cell can be a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0127] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module 6, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module 6 can be formed by bundling multiple battery cells together with cable ties.

[0128] In some embodiments, the battery device 2 may be a battery pack, which includes a housing 5 and one or more battery cell assemblies housed within the housing 5. As an example, the battery cell assembly may be a battery module 6, which can be housed within the housing by securing the battery module 6 to the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells to the housing.

[0129] In some embodiments, the housing 5 is used to house individual battery cells, and the housing 5 can have various structures.

[0130] In some embodiments, the housing 5 may include a first housing 5a and a second housing 5b. The first housing 5a and the second housing 5b are fastened together to form a closed space inside the housing 5 to house the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0131] In some embodiments, the housing 5 may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, forming an enclosed space inside the housing to accommodate individual battery cells. As an example, the frame may include multiple side beams.

[0132] In some embodiments, the housing 5 may be part of the vehicle's chassis structure. For example, a portion of the housing 5 may be at least a portion of the vehicle's floor, or a portion of the housing 5 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0133] In some embodiments, the battery device 2 may be an energy storage device.

[0134] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0135] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0136] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0137] In some embodiments, such as Figure 3 As shown, there are multiple battery cells 7, which are first connected in series, parallel, or a combination of both to form a battery module 6. These battery modules 6 are then connected in series, parallel, or a combination of both to form a whole, which is housed within the casing.

[0138] Multiple battery cells 7 in battery module 6 can be electrically connected through a busbar to achieve parallel, series, or mixed connection of multiple battery cells 7 in battery module 6. There can be one or more busbars, each used to electrically connect at least two battery cells 7.

[0139] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0140] In some embodiments, the outer casing may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing).

[0141] The outer shell can be a hollow structure, with an internal cavity for accommodating the electrode assembly and electrolyte.

[0142] In some embodiments, the casing of the battery cell is a cylindrical casing, a square casing, a prismatic casing, or a casing of other shapes.

[0143] In some embodiments, the housing includes a housing and an end cap, the housing having an opening and the end cap being connected to the housing and covering the opening;

[0144] The housing is a component used to fit the end cap to form the internal cavity of the battery cell. The formed internal cavity can be used to house the electrode assembly, electrolyte, and other components.

[0145] The housing and end cap can be separate components. For example, an opening can be provided on the housing, and the end cap can be used to close the opening to form an internal cavity for the battery cell.

[0146] The housing can come in various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing can be determined based on the specific shape and size of the electrode assembly. The housing can be made of various materials, such as copper, iron, aluminum, stainless steel, and aluminum alloy.

[0147] The shape of the end cap can be adapted to the shape of the housing to fit the housing. The material of the end cap can be the same as or different from that of the housing. Optionally, the end cap can be made of a material with a certain degree of hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap is not easily deformed when subjected to compression and impact, enabling the battery cell to have higher structural strength and improve reliability.

[0148] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0149] The housing may be open at one end or at both ends. In some examples, the housing may be a structure with an opening on one side, with one end cap fitting over the housing. In other examples, the housing may be a structure with openings on both sides, with two end caps fitting over the two openings of the housing, respectively.

[0150] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0151] In some embodiments, the electrode assembly includes a positive electrode, a negative electrode, and a separator, wherein the positive electrode and the negative electrode have opposite polarities, and the separator separates the positive electrode and the negative electrode.

[0152] At least a portion of the separator is located between the positive and negative electrode plates. During the charging and discharging of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrode plates. The separator, positioned between the positive and negative electrode plates, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0153] In some embodiments, the positive electrode may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector.

[0154] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0155] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0156] As an example, the positive electrode film layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional 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 phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0157] In some embodiments, the negative electrode may include a negative current collector.

[0158] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0159] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0160] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0161] As an example, the negative electrode film layer includes a negative electrode active material, which 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, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0162] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0163] In some embodiments, the separator includes a separator membrane. The separator membrane in this application can be any known porous membrane with good chemical and mechanical stability.

[0164] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different.

[0165] Inorganic particle coating, organic particle coating, or organic / inorganic composite coating can also be applied to the surface of the separator.

[0166] The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surface of the positive or negative electrode.

[0167] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrode plates, serving both to transport ions and to isolate the positive and negative electrodes.

[0168] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte used in this application can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0169] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0170] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0171] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0172] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0173] In some embodiments, the gel electrolyte comprises a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0174] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0175] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0176] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0177] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0178] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0179] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0180] In some implementations, the electrode assembly is a stacked structure.

[0181] As an example, multiple positive and negative electrode plates can be set, with multiple positive and multiple negative electrode plates stacked alternately. As an example, multiple positive electrode plates can be set, and negative electrode plates are folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0182] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0183] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0184] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0185] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0186] In some embodiments, the positive current collector may include a positive tab, and the negative current collector may include a negative tab. The positive and negative tabs can be used to transmit current. As an example, at least a portion of the positive tab is not coated with a positive film layer, and at least a portion of the negative tab is not coated with a negative film layer.

[0187] In some embodiments, the electrode assembly is a wound structure. The positive electrode tab is wound multiple turns along the winding direction. Optionally, the end of the positive electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. Optionally, the positive electrode tab is annular.

[0188] In some embodiments, the negative electrode tab is wound multiple turns along the winding direction. Optionally, the end of the negative electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. The negative electrode tab is annular.

[0189] In some embodiments, the electrode assembly includes an electrode body. As an example, the electrode body includes a positive electrode film, a portion of the positive electrode current collector covered by the positive electrode film, a negative electrode film, a portion of the negative electrode current collector covered by the negative electrode film, and a separator.

[0190] The positive and negative tabs can be led out from the same end of the electrode body, or they can be led out from opposite ends of the electrode body. At least a portion of the positive tab protrudes to the outside of the insulating member, and at least a portion of the negative tab protrudes to the outside of the insulating member.

[0191] In some embodiments, a battery cell includes a positive electrode lead and a negative electrode lead, wherein the positive electrode lead is electrically connected to a positive electrode plate and the negative electrode lead is electrically connected to a negative electrode plate.

[0192] The positive and negative leads are used to connect to the external circuit to enable charging or discharging of the battery cells.

[0193] In some embodiments, the positive lead-out portion includes a positive terminal. At least a portion of the positive terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0194] As an example, the positive terminal may be a separately molded component that is mounted on the housing. Alternatively, the positive terminal may also be part of the housing.

[0195] In some examples, the positive terminal is directly connected to the positive plate; in other examples, the positive terminal and the positive plate are indirectly connected through other conductive structures, such as a positive adapter plate.

[0196] In some embodiments, the positive terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0197] In some embodiments, the negative lead-out portion includes a negative terminal. At least a portion of the negative terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0198] As an example, the negative terminal can be a separately molded component that is mounted on the housing. Alternatively, the negative terminal can also be part of the housing.

[0199] In some examples, the negative terminal is directly connected to the negative electrode plate; in other examples, the negative lead-out section also includes other conductive structures connecting the negative terminal and the negative electrode plate, such as a negative electrode adapter plate.

[0200] In some embodiments, the negative terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0201] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in some embodiments of this application. Figure 5 This is a three-dimensional structural diagram of the casing of a battery cell provided in some embodiments of this application.

[0202] Continue to refer to Figures 4 to 5 This application provides a battery cell 7, which includes a housing 10, an end cap 30, and an electrode assembly 20. The housing 10 has an opening 101 at one end along a first direction X, and the end cap 30 covers the opening 101. The electrode assembly 20 is housed within the housing 10. The housing 10 includes at least two first walls 11 disposed opposite each other along the thickness direction Z of the electrode assembly 20. A first recess 110 is provided at the end of the first wall 11 near the end cap 30 along the first direction X. The first recess 110 penetrates the first wall 11 along the thickness direction Z, and the first direction X is perpendicular to the thickness direction Z. The first wall 11 includes a main body portion 111 and a first thickened portion 112. The first thickened portion 112 is connected to the main body portion 111. The dimension of the first thickened portion 112 along the thickness direction Z is larger than the dimension of the main body portion 111 along the thickness direction Z. Along the first direction X, at least a portion of the first thickened portion 112 is located on the side of the first recess 110 away from the end cap 30. The end cap 30 is welded to the first thickened portion 112.

[0203] The first recess 110 is used to facilitate adaptation to end caps 30 with different structures designed to improve energy density. For example, to improve the energy density of the battery cell 7, the end cap 30 may include a first cover portion 32 and a second cover portion 33. Along the first direction X, the second cover portion 33 is closer to the electrode assembly 20 than the first cover portion 32. Electrode terminals 40 are disposed on the second portion 1122 and electrically connected to the tabs. The second cover portion 33 is welded to the first thickened portion 112. The electrode terminals 40 being disposed on the second cover portion 33 effectively reduces the protrusion height of the electrode terminals 40, providing more installation space for the electrode terminals 40 and their related electrical connections during the assembly of the battery cell 7, and optimizing the overall layout of the assembled battery cell 7, thereby contributing to improved battery energy density.

[0204] Of course, in order to improve the energy density of the battery cell 7, other structural designs can be made to the end cover 30, as long as the first recess 110 can be adapted to the structure of the end cover 30.

[0205] For example, the end of the first wall 11 near the end cap 30 along the first direction X may include a first end face 114 and a second end face 115, the first recess 110 is recessed relative to the second end face 115, the first end face 114 is connected to the second end face 115 and is used to define the first recess 110, and the projection of the second end face 115 along the first direction X does not overlap with the projection of the first recess 110 along the first direction X.

[0206] Understandably, due to the presence of the first recess 110, the first end face 114 is closer to the central region of the electrode assembly 20 along the first direction X. In other words, the first end face 114 is closer to the central axis of the electrode assembly 20 parallel to the second direction Y along the first direction X. During the cyclic expansion of the electrode assembly 20, the expansion amount of the electrode assembly 20 is relatively greater closer to the central region. That is, the expansion amount of the electrode assembly 20 is relatively greater closer to its own central axis parallel to the second direction Y. This makes the welding area between the end cap 30 and the first wall 11 near the first recess 110 more prone to deformation and cracking.

[0207] In the thickness direction Z, the first thickened portion 112 may protrude from one side surface of the main body portion 111 along the thickness direction Z, or it may protrude from the two opposite sides surface of the main body portion 111 along the thickness direction Z.

[0208] The end cap 30 is welded to the first thickened portion 112 to form a welded portion. After the welded portion is formed, thermal stress remains in the area of ​​the first thickened portion 112 near the welded portion. Exemplarily, the projection of the welded portion along the thickness direction Z at least partially overlaps with the projection of the first thickened portion 112 along the thickness direction Z.

[0209] This embodiment increases the thickness of the first thickened portion 112 to improve the strength of the first wall 11 in the area near the weld, reduce the risk of cracking of the first wall 11, and improve reliability.

[0210] Furthermore, this embodiment only increases the thickness of the first thickened portion 112. Compared to the solution of increasing the overall thickness of the first wall 11, this embodiment can reduce the weight of the casing 10 and increase the energy density of the battery cell 7.

[0211] The first thickened portion 112 can be detachably connected to the main body portion 111, or it can be integrally provided on the main body portion 111. The first thickened portion 112 can be directly connected to the main body portion 111, or it can be restricted to the main body portion 111 by other components.

[0212] Along the first direction X, at least a portion of the first thickened portion 112 is located on the side of the first recess 110 away from the end cap 30. In other words, the projection of the first end face 114 along the first direction X at least partially overlaps with the projection of the first thickened portion 112 along the first direction X. Exemplarily, the first wall 11 includes a first end face 114 for defining the first recess 110, and at least a portion of the first thickened portion 112 may be spaced apart from the first end face 114 along the first direction X, or it may include at least a portion of the first end face 114.

[0213] Along the first direction X, the first thickened portion 112 may be partially located on the side of the first recess 110 away from the end cap 30, or it may be entirely located on the side of the first recess 110 away from the end cap 30.

[0214] The above technical solution improves the structural strength of the first wall 11 in the area near the first recess 110 by providing a first thickened portion 112 on the side of the first recess 110 away from the end cap 30 along the first direction X, thereby reducing the risk of cracking of the first wall 11 and improving the reliability of the battery cell 7.

[0215] For example, the thickness of the first thickened portion 112 and the main body portion 111 can be measured using a contact mechanical measurement method. As an example, the housing 10 is placed flat, and the thickness of the first thickened portion 112 and the main body portion 111 is measured directly using a precision caliper or micrometer. As another example, the thickness of the first thickened portion 112 and the main body portion 111 is measured directly using a thickness gauge, and then the thickness value is read.

[0216] Figure 6 This is a front view structural diagram of the first wall of a battery cell provided in some embodiments of this application.

[0217] Continue to refer to Figure 6 In some embodiments, the first wall 11 includes a first end face 114 for defining the first recess 110, and the first thickened portion 112 includes at least a portion of the first end face 114.

[0218] The first end face 114 is used to define the first recess 110; in other words, the shape of the first recess 110 is formed by the first end face 114.

[0219] The first thickened portion 112 includes at least a portion of the first end face 114. In other words, the end of the first thickened portion 112 near the end cap 30 along the first direction X is flush with at least a portion of the first end face 114.

[0220] The first thickened portion 112 may be a part of the first end face 114 or may include the entire first end face 114.

[0221] The above technical solution can more easily weld the end cap 30 to the first thickened part 112, reducing the difficulty of manufacturing the battery cell 7.

[0222] In some embodiments, the first thickened portion 112 includes the entire first end face 114 to further enhance the structural strength of the first wall 11 in the region near the first recess 110.

[0223] In some embodiments, the first wall 11 includes a first end face 114 for defining the first recess 110. The first end face 114 includes a bottom face 1141 and two side faces 1142. The two side faces 1142 are respectively connected to the two ends of the bottom face 1141 along the second direction Y. The first direction X, the second direction Y and the thickness direction Z are perpendicular to each other.

[0224] In some embodiments, the first thickened portion 112 includes at least a portion of the bottom surface 1141. In other words, one end of the first thickened portion 112 near the end cap 30 along the first direction X is flush with at least a portion of the bottom surface 1141.

[0225] The first thickened portion 112 may be a part of the bottom surface 1141 or it may include the entire bottom surface 1141.

[0226] In some embodiments, at least a portion of the first thickened portion 112 is located along a first direction X on the side of the bottom surface 1141 away from the end cap 30. In other words, at least a portion of the first thickened portion 112 is spaced apart from the bottom surface 1141 along the first direction X.

[0227] The first thickened portion 112 may be a portion located along the first direction X on the side of the bottom surface 1141 away from the end cap 30, or it may be entirely located along the first direction X on the side of the bottom surface 1141 away from the end cap 30.

[0228] It is understandable that the bottom surface 1141 of the first end face 114 is closer to the electrode assembly 20 than the side surface 1142. Therefore, during the cyclic expansion of the electrode assembly 20, the area near the bottom surface 1141 will be subjected to a greater expansion force from the electrode assembly 20.

[0229] Thus, by thickening the area near the bottom surface 1141, the above technical solution can effectively reduce the risk of cracking of the first wall 11.

[0230] In some embodiments, the dimension of the bottom surface 1141 along the second direction Y is greater than the dimension of the first thickened portion 112 along the second direction Y.

[0231] In some embodiments, the dimension of the bottom surface 1141 along the second direction Y is equal to the dimension of the first thickened portion 112 along the second direction Y.

[0232] Figure 7This is a front view structural diagram of the first wall of another battery cell provided in some embodiments of this application.

[0233] Continue to refer to Figure 7 In some embodiments, a portion of the first thickened portion 112 includes at least a portion of the side surface 1142. In other words, one end of the first thickened portion 112 near the end cap 30 along the first direction X is flush with at least a portion of the side surface 1142.

[0234] A portion of the first thickened portion 112 may be a part of the side 1142 or may include the entire side 1142.

[0235] In some embodiments, a portion of the first thickened portion 112 is located along the second direction Y on the side surface 1142 away from the bottom surface 1141. In other words, a portion of the first thickened portion 112 is spaced apart from the side surface 1142 along the second direction Y.

[0236] The above technical solution can further enhance the overall structural strength of the first wall 11 by thickening the area near the side 1142.

[0237] In some embodiments, the side surface 1142 includes a planar segment 11421 and a first arcuate segment 11422, the first arcuate segment 11422 being connected between the planar segment 11421 and the bottom surface 1141.

[0238] The first arc segment 11422 connects the planar segment 11421 and the bottom surface 1141 to form an arc structure that transitions from the planar surface to the bottom surface 1141.

[0239] This structural design can effectively improve the stress distribution in the area near the first arc segment 11422. The arc transition of the first arc segment 11422 alleviates the sharp corner or stress concentration problems that may occur when the planar segment 11421 is directly connected to the bottom surface 1141, and further improves the reliability of the shell 10.

[0240] In some embodiments, the first thickened portion 112 includes at least a portion of the planar segment 11421.

[0241] In some embodiments, a portion of the first thickened portion 112 is located along the second direction Y on the side of the planar segment 11421 away from the bottom surface 1141.

[0242] In some embodiments, the first thickened portion 112 includes at least a portion of the first arcuate segment 11422.

[0243] In some embodiments, a portion of the first thickened portion 112 is located along the second direction Y on the side of the first arcuate segment 11422 away from the bottom surface 1141.

[0244] In some embodiments, the side surface 1142 further includes a second arcuate segment 11423, which is connected to the end of the planar segment 11421 away from the first arcuate segment 11422.

[0245] For example, the first wall 11 further includes a second end face 115, the first recess 110 is recessed relative to the second end face 115, the first end face 114 is connected to the second end face 115 and is used to define the first recess 110, and the projection of the second end face 115 along the first direction X does not overlap with the projection of the first recess 110 along the first direction X, and the second arcuate segment 11423 is connected between the planar segment 11421 and the second end face 115 to form an arcuate structure that transitions from the planar segment 11421 to the second end face 115.

[0246] This structural design can effectively improve the stress distribution in the area near the second arc segment 11423. The arc transition of the second arc segment 11423 alleviates the sharp corner or stress concentration problems that may occur when the planar segment 11421 is directly connected to the second end face 115, and further improves the reliability of the housing 10.

[0247] In some embodiments, the first thickened portion 112 includes at least a portion of the second arcuate segment 11423.

[0248] In some embodiments, a portion of the first thickened portion 112 is located along the second direction Y on the side of the second arcuate segment 11423 away from the bottom surface 1141.

[0249] In some embodiments, the first thickened portion 112 includes at least a portion of the second arcuate segment 11423.

[0250] In some embodiments, a portion of the first thickened portion 112 is located along the second direction Y on the side of the second arc segment 11423 away from the bottom surface 1141.

[0251] In some embodiments, the projection of the first thickened portion 112 along the first direction X coincides with the projection of the bottom surface 1141 along the first direction X.

[0252] The above technical solution, by thickening the area only near the bottom surface 1141, can reduce the risk of cracking of the first wall 11 and reduce the volume of the thickened part to a certain extent, thereby further reducing the weight of the casing 10 and increasing the energy density of the battery cell 7.

[0253] Figure 8 This is a top view of the casing of a battery cell provided in some embodiments of this application. Figure 9 for Figure 8 A magnified schematic diagram of the local structure at point F.

[0254] Continue to refer to Figures 8 to 9In some embodiments, the first thickened portion 112 includes a first portion 1121 and two second portions 1122. The two second portions 1122 are respectively connected to the two ends of the first portion 1121 along the second direction Y. The maximum dimension of the second portion 1122 along the thickness direction Z is smaller than the maximum dimension of the first portion 1121 along the thickness direction Z. The first direction X, the second direction Y and the thickness direction Z are perpendicular to each other.

[0255] For example, the first part 1121 can be understood as the middle part of the first thickened part 112, and the second part 1122 can be understood as the edge part of the first thickened part 112 along the second direction Y. The maximum thickness of the second part 1122 is less than the maximum thickness of the first part 1121, that is, the thickness of the second part 1122 is generally smaller than the thickness of the first part 1121.

[0256] Part 1121 and Part 1122 may be made of the same material or different materials.

[0257] As an example, the first part 1121 and the second part 1122 are made of the same material, which can simplify the manufacturing process and reduce costs.

[0258] Understandably, when the housing 10 is manufactured using processes such as injection molding or stamping, it needs to be removed from the mold after it has solidified or set. The edge portion of the first thickened portion 112 is less prone to deformation than the middle portion. Therefore, appropriately reducing the thickness of the second portion 1122 reduces the contact area between the second portion 1122 and the mold, thereby reducing friction or jamming during demolding and facilitating demolding of the housing 10.

[0259] The above technical solution helps the inner shell 10 of the mold to be more easily ejected in the direction of the draft during the molding process, reducing the risk of jamming or sticking, while optimizing stress distribution and reducing the probability of part deformation, so as to improve production efficiency and product qualification rate.

[0260] In some embodiments, the second portion 1122 has a gradually decreasing dimension along the thickness direction Z in the direction from the first portion 1121 to the second portion 1122.

[0261] For example, the thickness of the second portion 1122 can vary linearly, meaning the thickness of the second portion 1122 decreases uniformly along the direction from the first portion 1121 to the second portion 1122. The thickness of the second portion 1122 can also vary non-linearly, meaning the thickness of the second portion 1122 gradually decreases along the direction from the first portion 1121 to the second portion 1122 according to a specific curve (such as a quadratic curve or a parabola). The thickness of the second portion 1122 can also vary in a stepwise manner, meaning the thickness of the second portion 1122 decreases segmentally and progressively along the direction from the first portion 1121 to the second portion 1122.

[0262] The gradual reduction in thickness of the second part 1122 of the above technical solution can effectively distribute the load, reduce local stress concentration, and reduce structural cracking and damage caused by material fatigue or external impact, significantly improving the overall durability and reliability of the structure. Furthermore, while maintaining structural strength, by rationally designing the thickness reduction area and reducing material usage, the overall weight of the battery cell 7 can be reduced, thereby helping to improve the energy density of the battery cell 7.

[0263] In some embodiments, a portion of the first thickened portion 112 protrudes from the side of the main body portion 111 facing the electrode assembly 20 in the thickness direction Z. This improves the flatness of the outer surface of the housing 10, thereby facilitating the assembly of the battery cell 7 and improving the appearance quality of the battery cell 7.

[0264] Figure 10 This is a three-dimensional structural diagram of the end cap 30 of a battery cell 7 provided in some embodiments of this application. Figure 11 for Figure 10 A magnified schematic diagram of the local structure at point G.

[0265] Continue to refer to Figures 10 to 11 In some embodiments, a portion of the end cap 30 is disposed within the housing 10, and the end cap 30 is provided with a groove 31 recessed along the thickness direction Z on the side facing the first wall 11, and at least a portion of the first thickened portion 112 is accommodated in the groove 31.

[0266] For example, the first thickened portion 112 may be partially or entirely contained within the groove 31. The structural shape of the groove 31 matches the structural shape of the first thickened portion 112.

[0267] The above technical solution reduces the interference between the end cover 30 and the first thickened part 112 during the assembly of the end cover 30 and the housing 10 by setting a groove 31 on the end cover 30 to avoid the first thickened part 112, which facilitates the assembly between the end cover 30 and the housing 10 and improves the assembly efficiency of the battery cell 7.

[0268] In some embodiments, the first thickened portion 112 abuts against the wall surface of the groove 31 in the first direction X. In other words, the side of the first thickened portion 112 near the end cap 30 along the first direction X abuts against the side wall surface of the groove 31 along the first direction X.

[0269] The first thickened portion 112 can limit the end cover 30 along the first direction X, which not only plays a certain positioning role in the assembly process of the end cover 30 and the housing 10, improving assembly efficiency, but also enables the first thickened portion 112 to play a certain supporting role for the end cover 30, improving the stability of the end cover 30.

[0270] In some embodiments, the first thickened portion 112 abuts against the wall of the groove 31 in the thickness direction Z. In other words, the side of the first thickened portion 112 closest to the electrode assembly 20 in the thickness direction Z abuts against the wall of the groove 31 in the thickness direction Z. This increases the contact area between the first thickened portion 112 and the end cap 30, thereby further improving the stability of the end cap 30.

[0271] Figure 12 for Figure 5 A magnified schematic diagram of the structure at point H.

[0272] Continue to refer to Figure 12 In some embodiments, the thickness of at least a portion of the first thickened portion 112 gradually decreases along the direction from the end cap 30 to the electrode assembly 20.

[0273] For example, the thickness of a portion of the first thickened portion 112 may gradually decrease along the direction from the end cap 30 to the electrode assembly 20, while the thickness of another portion of the first thickened portion 112 remains unchanged; or the thickness of the entire first thickened portion 112 may gradually decrease along the direction from the end cap 30 to the electrode assembly 20.

[0274] The thickness of the first thickened part 112 can vary linearly or non-linearly, such as a quadratic curve or a step-like variation. The specific form can be adjusted according to the actual application requirements.

[0275] The above technical solution can reduce the risk of the electrode assembly 20 being damaged by the compression of the first thickened portion 112. The gradual reduction in the thickness of the first thickened portion 112 can effectively distribute the load, reduce local stress concentration, reduce structural cracking and damage caused by material fatigue or external impact, and significantly improve the overall durability and reliability of the structure. In addition, while maintaining structural strength, by rationally designing the thickness reduction area and reducing the amount of material used, the overall weight of the battery cell 7 can be reduced, thereby helping to improve the energy density of the battery cell 7.

[0276] In some embodiments, the first thickened portion 112 includes a first segment 1123 and a second segment 1124, the second segment 1124 being connected to the side of the first segment 1123 away from the end cap 30 along a first direction X. Along the direction from the end cap 30 toward the electrode assembly 20, the thickness of the first segment 1123 remains constant, while the thickness of the second segment 1124 gradually decreases.

[0277] For example, the first segment 1123 and the second segment 1124 are arranged along the first direction X. The second segment 1124 can be directly connected to the first segment 1123, or it can be indirectly connected to the first segment 1123 through other components.

[0278] The uniform thickness design of the first segment 1123 ensures, to some extent, that the connection between the end cap 30 and the first thickened portion 112 has sufficient welding or sealing area, improving the mechanical strength and sealing performance of the connection. The thickness of the second segment 1124 gradually decreases along the direction from the end cap 30 to the electrode assembly 20, which can reduce local stress concentration, reduce material usage, and to some extent avoid crushing damage to the electrode assembly 20.

[0279] The above technical solution achieves a balance between the structural strength and space occupation of the first thickened part 112 by subdividing the first thickened part 112 into a first segment 1123 with a constant thickness and a second segment 1124 with a gradually decreasing thickness. This not only improves the reliability of the battery cell 7, but also optimizes the internal space utilization of the battery cell 7, which helps to improve the energy density of the battery cell 7.

[0280] In some embodiments, the end cap 30 is welded to the first segment 1123.

[0281] In some embodiments, a portion of the end cap 30 is disposed within the housing 10, and the end cap 30 is provided with a groove 31 recessed along the thickness direction Z on the side facing the first wall 11, and at least a portion of the first segment 1123 is accommodated in the groove 31.

[0282] In some embodiments, the first segment 1123 abuts against the wall of the groove 31 in the first direction X.

[0283] In some embodiments, the first thickened portion 112 further includes a third segment 1125, which is connected to the second segment 1124 on the side away from the first segment 1123 along the first direction X. Along the direction from the end cap 30 to the electrode assembly 20, the thickness of the third segment 1125 gradually decreases, and the thickness change per unit length in the direction from the end cap 30 to the electrode assembly 20 is greater than the thickness change of the second segment 1124.

[0284] For example, the first segment 1123, the second segment 1124 and the third segment 1125 are arranged along the first direction X. The third segment 1125 can be directly connected to the second segment 1124, or it can be indirectly connected to the second segment 1124 through other components.

[0285] Over a unit length in the direction from end cap 30 to electrode assembly 20, the thickness change of the third segment 1125 is greater than that of the second segment 1124. This can be understood as the second segment 1124 decreasing in thickness relative to the third segment 1125 in the direction from end cap 30 to electrode assembly 20.

[0286] The above technical solution, by introducing a third segment 1125 and forming a multi-segment thickness-decreasing structure with the second segment 1124, can effectively allocate the emphasis on the fabrication and function of the first thickened portion 112, and also achieve a reasonable thickness gradient. On the one hand, the relatively gentle thickness reduction process of the second segment 1124 helps to reduce the fabrication difficulty of the first thickened portion 112; on the other hand, the relatively rapid thickness reduction process of the third segment 1125 helps to meet the overall thickness reduction requirements of the first thickened portion 112.

[0287] In some embodiments, the thickness of the second segment 1124 varies non-linearly.

[0288] In some embodiments, the thickness of the third segment 1125 varies linearly.

[0289] In some embodiments, the first thickened portion 112 further includes a fourth segment 1126, which is connected to the third segment 1125 on the side away from the second segment 1124 along the first direction X. Along the direction from the end cap 30 to the electrode assembly 20, the thickness of the fourth segment 1126 gradually decreases, and the thickness change per unit length in the direction from the end cap 30 to the electrode assembly 20 is less than the thickness change of the third segment 1125.

[0290] For example, the first segment 1123, the second segment 1124, the third segment 1125 and the fourth segment 1126 are arranged along the first direction X. The fourth segment 1126 can be directly connected to the third segment 1125, or it can be indirectly connected to the third segment 1125 through other components.

[0291] Over a unit length in the direction from end cap 30 to electrode assembly 20, the thickness change of the fourth segment 1126 is less than that of the third segment 1125. This can be understood as the thickness of the fourth segment 1126 decreasing more slowly relative to the thickness of the third segment 1125 in the direction from end cap 30 to electrode assembly 20.

[0292] The above technical solution can further reduce the difficulty of manufacturing the first thickened part 112 by introducing a fourth segment 1126.

[0293] In some embodiments, the thickness of the fourth segment 1126 varies non-linearly.

[0294] In some embodiments, along the first direction X, the entire first thickened portion 112 is located on the side of the first recess 110 away from the end cap 30. In other words, the entire first thickened portion 112 is located on the side of the first recess 110 away from the end cap 30.

[0295] For example, the projection of the entire first thickened portion 112 along the first direction X is located within the projection of the first recess 110 along the first direction X.

[0296] As an example, the first wall 11 may include a first end face 114 for defining the first recess 110, and the entire first thickened portion 112 may be spaced apart from the first end face 114 along a first direction X, or may include at least a portion of the first end face 114.

[0297] By providing a first thickened portion 112 only for the area near the first recess 110 of the first wall 11, the structural strength of that area can be improved. This reduces the risk of cracking of the first wall 11 and improves the reliability of the battery cell 7. At the same time, it can reduce the amount of the first thickened portion 112 to a certain extent, thereby increasing the energy density of the battery cell 7 and reducing the cost.

[0298] Figure 13 This is a front view structural diagram of the first wall 11 of another battery cell 7 provided in some embodiments of this application.

[0299] Continue to refer to Figure 13 In some embodiments, the first wall 11 further includes a second thickened portion 113, which is disposed along the second direction Y with the first thickened portion 112, and the projection of the second thickened portion 113 along the first direction X does not overlap with the projection of the first recess 110 along the first direction X, and the first direction X, the second direction Y and the thickness direction Z are perpendicular to each other.

[0300] For example, the first thickened portion 112 and the second thickened portion 113 may be connected together, or the first thickened portion 112 and the second thickened portion 113 may be spaced apart along the second direction Y.

[0301] As an example, when the first thickened portion 112 and the second thickened portion 113 are connected, the first thickened portion 112 may be directly connected to the second thickened portion 113, or it may be indirectly connected to the second thickened portion 113 through other components.

[0302] The dimensions of the first thickened portion 112 along the thickness direction Z and the dimensions of the second thickened portion 113 along the thickness direction Z can be the same or different.

[0303] By further adding a second thickened portion 113, the structural strength of the first wall 11 can be further improved, the risk of cracking of the first wall 11 can be reduced, and the reliability of the battery cell 7 can be further improved.

[0304] In some embodiments, a portion of the end cap 30 is welded to the second thickened portion 113.

[0305] In some embodiments, the first thickened portion 112 is directly connected to the second thickened portion 113, forming a reinforced structure that enables both to work together to withstand external forces, effectively improving the overall structural strength of the first wall 11. This structural design not only optimizes the stress distribution and improves the deformation resistance of the first wall 11, but also facilitates the fabrication of the first thickened portion 112 and the second thickened portion 113 through an integral molding process, thereby simplifying the production process, reducing manufacturing costs, and improving production efficiency.

[0306] In some embodiments, along the first direction X, one end of the first thickened portion 112 away from the end cap 30 is flush with one end of the second thickened portion 113 away from the end cap 30.

[0307] This flush design ensures that the first thickened portion 112 and the second thickened portion 113 are structurally consistent. When the first wall 11 is subjected to external pressure or vibration, the stress on the first wall 11 is more evenly distributed at the locations of the first thickened portion 112 and the second thickened portion 113, which to some extent avoids excessive stress concentration in one area, thereby optimizing the stress condition of the first wall 11 and reducing the possibility of structural weaknesses. Furthermore, this flush design makes it easier to process the first thickened portion 112 and the second thickened portion 113 using a one-piece molding process, without the need for separate process adjustments.

[0308] Thus, the above technical solution can further improve the reliability of the battery cell 7 and reduce costs.

[0309] In some embodiments, the first wall 11 includes a first end face 114 and a second end face 115, the first recess 110 is recessed relative to the second end face 115, the first end face 114 is connected to the second end face 115 and is used to define the first recess 110, and the projection of the second end face 115 along the first direction X does not overlap with the projection of the first recess 110 along the first direction X.

[0310] The first end face 114 is used to define the first recess 110; in other words, the shape of the first recess 110 is formed by the first end face 114.

[0311] In some embodiments, the first thickened portion 112 includes at least a portion of the first end face 114. In other words, one end of the first thickened portion 112 near the end cap 30 along the first direction X is flush with at least a portion of the first end face 114. The first thickened portion 112 may include a part of the first end face 114 or may include the entire first end face 114.

[0312] In some embodiments, the second thickened portion 113 includes at least a portion of the second end face 115. In other words, one end of the second thickened portion 113 near the end cap 30 along the first direction X is flush with at least a portion of the second end face 115. The second thickened portion 113 may include a part of the second end face 115 or may include the entire second end face 115.

[0313] This embodiment can use an integral molding process to process a first wall 11 with a first thickened portion 112 and a second thickened portion 113, and then directly process a first recess 110 on the first thickened portion 112. Furthermore, it is easier to weld the end cap 30 to the first thickened portion 112, and easier to weld the end cap 30 to the second thickened portion 113.

[0314] Thus, the above technical solution can further simplify the manufacturing process of battery cell 7 and reduce the difficulty of manufacturing battery cell 7.

[0315] Figure 14 This is a schematic diagram of the exploded structure of another battery cell provided in some embodiments of this application.

[0316] Continue to refer to Figure 14 In some embodiments, there are multiple first recesses 110, which are spaced apart along the second direction Y, and the first direction X, the second direction Y, and the thickness direction Z are perpendicular to each other. There are multiple first thickened portions 112, each of which is corresponding to a first recess 110.

[0317] For example, the number of first recesses 110 can be one, two, three or more, depending on the actual application environment.

[0318] The number of first thickened portions 112 corresponds to the number of first recesses 110. As an example, there are two first recesses 110 and two first thickened portions 112, along the first direction X, where at least a portion of one of the first thickened portions 112 is located on the side of one of the first recesses 110 away from the end cap 30, and at least a portion of the other first thickened portion 112 is located on the side of the other first recess 110 away from the end cap 30.

[0319] By setting the number of first recesses 110 to multiple, the design flexibility of the first wall 11 can be further improved, thereby increasing the applicability of the battery cell 7.

[0320] In some embodiments, at least a portion of the first recesses 110 are disposed at both ends of the first wall 11 along the second direction Y, wherein the first direction X, the second direction Y and the thickness direction Z are perpendicular to each other.

[0321] As an example, there are two first recesses 110, which are disposed at both ends of the first wall 11 along the second direction Y.

[0322] For example, the end of the first wall 11 near the end cap 30 along the first direction X may include a first end face 114 and a second end face 115, the first recess 110 is recessed relative to the second end face 115, the first end face 114 is connected to the second end face 115 and is used to define the first recess 110, and the projection of the second end face 115 along the first direction X does not overlap with the projection of the first recess 110 along the first direction X.

[0323] By providing a first recess 110 at the end of the first wall 11 along the second direction Y, the first recess 110 is relatively far from the central region of the electrode assembly 20, thereby reducing the expansion force from the electrode assembly 20 on the first wall 11 near the first recess 110. This reduces the risk of cracking in the welding area between the end cap 30 and the first wall 11 near the first recess 110, and improves the reliability of the battery cell 7.

[0324] In some embodiments, the first recess 110 is located in the middle region of the first wall 11 along the second direction Y, and the first direction X, the second direction Y and the thickness direction Z are perpendicular to each other.

[0325] As an example, refer to Figure 4 The number of first recesses 110 is one, and one first recess 110 is located in the middle region of the first wall 11 along the second direction Y.

[0326] The first recess 110 of this application is located in the middle region of the first wall 11 along the second direction Y. This includes not only the case where the first recess 110 is absolutely located in the middle region of the first wall 11 along the second direction Y, but also the case where the first recess 110 is generally located in the middle region of the first wall 11 along the second direction Y, as is commonly understood in engineering.

[0327] The above technical solution enables the electrode terminal 40 to be located in the middle area of ​​the first wall 11, which can reduce the risk of the battery cell 7 interfering with other structures during the assembly process and causing damage to the electrode terminal 40.

[0328] For example, the end cap 30 includes two first cap portions 32 and a second cap portion 33, which are disposed along a second direction Y, and the second cap portion 33 is connected between the two first cap portions 32.

[0329] The second recesses 301 corresponding to the two first cover portions 32 can respectively accommodate two tabs with opposite polarities, so that the tabs with opposite polarities are separated by the second cover portion 33, reducing the risk of short circuit of the battery cell 7 and improving the reliability of the battery cell 7.

[0330] In some embodiments, the projections of the first thickened portions 112 of the two first walls 11 along the thickness direction Z at least partially overlap.

[0331] It can form a more uniform stress support structure on the housing 10, reduce the risk of deformation of the housing 10 due to uneven stress, and thus further improve the reliability of the battery cell 7.

[0332] For example, the projections of the first thickened portions 112 of the two first walls 11 along the thickness direction Z can be partially overlapping or completely overlapping.

[0333] In some embodiments, the dimension of the first thickened portion 112 along the thickness direction Z is 0.05mm-0.5mm.

[0334] For example, the dimension of the first thickened portion 112 along the thickness direction Z can be understood as the thickness of the first thickened portion 112.

[0335] As an example, the dimension of the first thickened portion 112 along the thickness direction Z can be, but is not limited to, 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.5mm, etc.

[0336] Understandably, the greater the thickness of the first thickened portion 112, the better its effect on strengthening the structural strength of the first wall 11. However, the larger the space occupied by the first thickened portion 112, the more difficult it is to demold. Conversely, the smaller the thickness of the first thickened portion 112, the worse its effect on strengthening the structural strength of the first wall 11. However, the smaller the space occupied by the first thickened portion 112, the easier it is to demold.

[0337] By setting the thickness of the first thickened portion 112 within the aforementioned range, the above-mentioned technical solution can reduce the risk of cracking of the first wall 11, improve the reliability of the battery cell 7, and at the same time, reduce the impact on the energy density of the battery cell 7 and reduce the manufacturing difficulty to a certain extent.

[0338] For example, the thickness of the first thickened portion 112 can be measured using a contact mechanical measurement method. As an example, the housing 10 is placed flat, and the thickness of the first thickened portion 112 is measured directly using a precision caliper or micrometer. As another example, the first thickened portion 112 is measured directly using a thickness gauge, and the thickness value is then read.

[0339] In some embodiments, the first thickened portion 112 has a dimension of 0.1 mm to 0.3 mm along the thickness direction Z. This can further improve the balance between the reliability, energy density, and manufacturing difficulty of the battery cell 7.

[0340] In some embodiments, the dimension of the first thickened portion 112 along the first direction X is 0.5mm-20mm.

[0341] For example, the dimension of the first thickened portion 112 along the first direction X can be understood as the height of the first thickened portion 112.

[0342] As an example, the size of the first thickened portion 112 along the first direction X can be, but is not limited to, 0.5mm, 1mm, 2mm, 5mm, 10mm, 15mm, 20mm, etc.

[0343] Understandably, the larger the dimension of the first thickened portion 112 along the first direction X, the better the strengthening effect of the first thickened portion 112 on the structural strength of the first wall 11. At the same time, the space occupied by the first thickened portion 112 is also larger, and demolding is more difficult. Conversely, the smaller the dimension of the first thickened portion 112 along the first direction X, the worse the strengthening effect of the first thickened portion 112 on the structural strength of the first wall 11. At the same time, the space occupied by the first thickened portion 112 is smaller, and demolding is easier.

[0344] The above technical solution, by setting the size of the first thickened portion 112 along the first direction X within the above range, can reduce the risk of cracking of the first wall 11, improve the reliability of the battery cell 7, and at the same time reduce the impact on the energy density of the battery cell 7 and reduce the manufacturing difficulty to a certain extent.

[0345] For example, the dimension of the first thickened portion 112 along the first direction X can be measured using contact mechanical measurement. As an example, the housing 10 is placed flat, and the dimension of the first thickened portion 112 along the first direction X is measured directly using a precision caliper or micrometer. As another example, the first thickened portion 112 is measured directly using a rangefinder, and then the measurement value is read.

[0346] In some embodiments, the first thickened portion 112 has a dimension of 1mm-10mm along the first direction X. This can further improve the balance between the reliability, energy density, and manufacturing difficulty of the battery cell 7.

[0347] As an example, the size of the first thickened portion 112 along the first direction X can be, but is not limited to, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.

[0348] In some embodiments, the end cap 30 includes a first cap portion 32 and a second cap portion 33. Along a first direction X, the second cap portion 33 is closer to the electrode assembly 20 than the first cap portion 32. The second cap portion 33 is welded to the first thickened portion 112.

[0349] For example, along the first direction X, the first cover portion 32 has a first surface facing away from the electrode assembly 20 and a second surface facing the electrode assembly 20, and the second cover portion 33 protrudes from the second surface in a direction close to the electrode assembly 20. A recessed region is formed on the side of the end cap 30 facing away from the electrode assembly 20, and the recessed region is disposed opposite to the second cover portion 33 along the first direction X.

[0350] The recessed area can be formed on the end cap 30 by means of grooving, stamping, casting, bending, etc. The end cap 30 can be a one-piece molded structure. For example, the end cap 30 can be a one-piece molded structure formed by one-piece molding methods such as stamping and casting.

[0351] The space formed by the height difference between the first cover portion 32 and the second cover portion 33 in the first direction X helps to reduce the overall volume of the battery cell 7 and increase the energy density of the battery cell 7.

[0352] In some embodiments, the battery cell 7 further includes an electrode terminal 40, the electrode assembly 20 includes a tab, and the electrode terminal 40 is disposed on the second cover portion 33 and electrically connected to the tab.

[0353] For example, at least a portion of the electrode terminal 40 is accommodated in the aforementioned recessed region.

[0354] In some examples, along the first direction X, the electrode terminal 40 may protrude from the surface of the second cover 33 away from the electrode assembly 20. Of course, the surface of the electrode terminal 40 away from the electrode assembly 20 may also be flush with the surface of the second cover 33 away from the electrode assembly 20, or the surface of the electrode terminal 40 away from the electrode assembly 20 may be closer to the electrode assembly 20 than the surface of the second cover 33 away from the electrode assembly 20.

[0355] In an embodiment where the battery cell 7 includes two electrode terminals 40, both electrode terminals 40 may be disposed on the second cover portion 33; alternatively, one electrode terminal 40 may be disposed on the second cover portion 33 and the other electrode terminal 40 may be disposed on the first cover portion 32.

[0356] By placing the electrode terminal 40 on the second cover portion 33, the electrode terminal 40 can make full use of the space formed by the height difference between the first cover portion 32 and the second cover portion 33 in the first direction X, which is beneficial to reduce the size of the battery cell 7 and increase the energy density of the battery cell 7.

[0357] In some embodiments, along the first direction X, the first cover portion 32 protrudes from the surface of the electrode terminal 40 away from the electrode assembly 20. That is, there is a height difference between the first cover portion 32 and the electrode terminal 40 in the first direction X, and the surface of the first cover portion 32 away from the electrode assembly 20 is further away from the electrode assembly 20 than the surface of the electrode terminal 40 away from the electrode assembly 20.

[0358] By extending along the first direction X, the first cover portion 32 protrudes from the surface of the electrode terminal 40 away from the electrode assembly 20, and a space is formed between the portion of the first cover portion 32 that extends beyond the surface of the electrode terminal 40 away from the electrode assembly 20 and the electrode terminal 40. This space can be used to accommodate other structures (such as busbar components) connected to the electrode terminal 40, making it easier to electrically connect the battery cell 7 to other structures, reducing the risk of interference when the battery cell 7 is electrically connected to other structures, and improving the stability of the electrical connection.

[0359] In some embodiments, a second recess 301 is formed on the side of the end cap 30 facing the electrode assembly 20. Along the first direction X, the second recess 301 is disposed opposite to the first cover portion 32, and at least a portion of the electrode tab is accommodated in the second recess 301.

[0360] For example, along the first direction X, the second cover portion 33 has a third surface facing away from the electrode assembly 20 and a fourth surface facing the electrode assembly 20. The first cover portion 32 protrudes from the third surface in a direction away from the electrode assembly 20, and the second recess 301 is recessed from the fourth surface in a direction away from the electrode assembly 20. The second recess 301 and the first cover portion 32 are disposed opposite to each other, and along the first direction X, the projection of the first cover portion 32 can be located within the projection of the second recess 301. The wall shape of the second recess 301 located on the end cap 30 can match the shape of the outer surface of the first cover portion 32 in the first direction X.

[0361] The second recess 301 can be formed on the end cap 30 by means of grooving, stamping, casting, bending, etc. The electrode lug can be completely accommodated in the second recess 301, or it can be partially accommodated in the second recess 301.

[0362] The above technical solution accommodates at least a portion of the tab within the second recess 301, thereby enabling the tab to fully utilize the space formed by the height difference between the first cover portion 32 and the second cover portion 33 in the first direction X, which is beneficial for reducing the size of the battery cell 7 and increasing the energy density of the battery cell 7.

[0363] In some embodiments, the projection of the electrode terminal 40 along the second direction Y at least partially overlaps with the projection of the tab along the second direction Y, and the first direction X, the second direction Y and the thickness direction Z are perpendicular to each other.

[0364] This allows the electrode terminals 40 and the tabs to make fuller use of the space formed by the height difference between the first cover portion 32 and the second cover portion 33 in the first direction X, which is beneficial to reduce the size of the battery cell 7 and increase the energy density of the battery cell 7.

[0365] In some embodiments, the housing 10 further includes two second walls 12, which are disposed opposite to each other along the second direction Y, and the two second walls 12 are respectively connected between the two first walls 11, with the first direction X, the second direction Y and the thickness direction Z being perpendicular to each other.

[0366] The first wall 11 and the second wall 12 can be made of the same material or different materials.

[0367] As an example, the first wall 11 and the second wall 12 are made of the same material, which helps to reduce the manufacturing process and lower costs.

[0368] According to some embodiments of this application, this application also provides a battery device including a battery cell 7 of any of the above schemes.

[0369] According to some embodiments of this application, this application also provides an electrical device, including a battery cell 7 or a battery device of any of the above schemes, wherein the battery cell 7 or the battery device is used to store or provide electrical energy.

[0370] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. All technical features and optional technical features of this application can be combined to form new technical solutions.

[0371] To better understand the battery cell 7 provided in the embodiments of this application, based on the same inventive concept, embodiments of the battery cell 7 in practical applications are provided here for illustration.

[0372] This application provides a battery cell 7, which includes a housing 10, an end cap 30, electrode terminals 40, and an electrode assembly 20. The housing 10 has an opening 101 at one end along a first direction X, and the end cap 30 closes to the opening 101. The electrode assembly 20 is housed within the housing 10. The end cap 30 includes a first cover portion 32 and a second cover portion 33. Along the first direction X, the second cover portion 33 is closer to the electrode assembly 20 than the first cover portion 32. The electrode assembly 20 includes tabs, and the electrode terminals 40 are disposed on the second cover portion 33 and electrically connected to the tabs.

[0373] The housing 10 includes at least two first walls 11 disposed opposite each other along the thickness direction Z of the electrode assembly 20. A first recess 110 is provided at one end of the first wall 11 near the end cap 30 along the first direction X. The first recess 110 penetrates the first wall 11 along the thickness direction Z. The first wall 11 includes a first end face 114 for defining the first recess 110. The first direction X is perpendicular to the thickness direction Z.

[0374] A second recess 301 is formed on the side of the end cap 30 facing the electrode assembly 20. Along the first direction X, the second recess 301 is disposed opposite to the first cap portion 32, and at least a portion of the electrode tab is accommodated in the second recess 301. The projection of the electrode terminal 40 along the second direction Y at least partially overlaps with the projection of the electrode tab along the second direction Y. The first direction X, the second direction Y, and the thickness direction Z are perpendicular to each other.

[0375] The first wall 11 includes a main body 111 and a first thickened portion 112. The first thickened portion 112 is connected to the main body 111. The dimension of the first thickened portion 112 along the thickness direction Z is larger than that of the main body 111 along the thickness direction Z. Along the first direction X, at least a portion of the first thickened portion 112 is located on the side of the first recess 110 away from the end cap 30. The first thickened portion 112 includes the entire first end face 114. The second cap portion 33 is welded to the first thickened portion 112. The dimension of the first thickened portion 112 along the thickness direction Z is 0.1mm-0.3mm.

[0376] By providing a first recess 110 on the first wall 11 of the housing 10 and a second cover 33 that cooperates with it on the end cover 30, the electrode terminal 40 is disposed on the second cover 33, which effectively reduces the protrusion height of the electrode terminal 40. During the assembly of the battery cell 7, it can provide more installation space for the electrode terminal 40 and its related electrical connectors, and optimize the overall layout of the battery cell 7 after assembly, thereby helping to improve the battery energy density.

[0377] By providing a first thickened portion 112 on the side of the first recess 110 away from the end cap 30 along the first direction X, the structural strength of the first wall 11 in the area near the first recess 110 is improved, the risk of cracking of the first wall 11 is reduced, and the reliability of the battery cell 7 is improved.

[0378] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0379] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The housing has an opening at one end along a first direction; End cap, which closes the opening; Electrode assembly, housed within the housing; The housing includes at least two first walls disposed opposite each other along the thickness direction of the electrode assembly. A first recess is provided at one end of the first wall near the end cap along the first direction. The first recess penetrates the first wall along the thickness direction, and the first direction is perpendicular to the thickness direction. The first wall includes a main body and a first thickened portion, the first thickened portion being connected to the main body, the dimension of the first thickened portion along the thickness direction being greater than the dimension of the main body along the thickness direction, at least a portion of the first thickened portion being located on the side of the first recess away from the end cap along the first direction, and the end cap being welded to the first thickened portion.

2. The battery cell according to claim 1, characterized in that, The first wall includes a first end face for defining the first recess, and the first thickened portion includes at least a portion of the first end face.

3. The battery cell according to claim 2, characterized in that, The first thickened portion includes the entire first end face.

4. The battery cell according to claim 1, characterized in that, The first wall includes a first end face for defining the first recess, the first end face including a bottom surface and two side surfaces, the two side surfaces being respectively connected to both ends of the bottom surface along a second direction, the first direction, the second direction and the thickness direction being perpendicular to each other; The first thickened portion includes at least a portion of the bottom surface, or at least a portion of the first thickened portion is located on the side of the bottom surface away from the end cap along the first direction.

5. The battery cell according to claim 4, characterized in that, A portion of the first thickened portion includes at least a portion of the side surface, or a portion of the first thickened portion is located along the second direction on the side surface away from the bottom surface.

6. The battery cell according to claim 4, characterized in that, The projection of the first thickened portion along the first direction coincides with the projection of the bottom surface along the first direction.

7. The battery cell according to claim 1, characterized in that, The first thickened portion includes a first part and two second parts. The two second parts are respectively connected to the two ends of the first part along the second direction. The maximum dimension of the second part along the thickness direction is smaller than the maximum dimension of the first part along the thickness direction. The first direction, the second direction and the thickness direction are perpendicular to each other.

8. The battery cell according to claim 7, characterized in that, Along the direction from the first portion to the second portion, the dimension of the second portion gradually decreases along the thickness direction.

9. The battery cell according to claim 1, characterized in that, In the thickness direction, a portion of the first thickened portion protrudes from the side of the main body facing the electrode assembly.

10. The battery cell according to claim 1, characterized in that, A portion of the end cap is disposed within the housing, and the end cap has a groove recessed along the thickness direction on the side facing the first wall, at least a portion of the first thickened portion being accommodated in the groove.

11. The battery cell according to claim 10, characterized in that, The first thickened portion abuts against the wall of the groove in the first direction.

12. The battery cell according to claim 1, characterized in that, Along the direction from the end cap toward the electrode assembly, the thickness of at least a portion of the first thickened portion gradually decreases.

13. The battery cell according to claim 12, characterized in that, The first thickened portion includes a first segment and a second segment, wherein the second segment is connected to the first segment on the side away from the end cap along the first direction; Along the direction from the end cap to the electrode assembly, the thickness of the first segment remains constant, while the thickness of the second segment gradually decreases.

14. The battery cell according to claim 13, characterized in that, The first thickened portion further includes a third segment, which is connected to the second segment on the side away from the first segment along the first direction; Along the direction from the end cap to the electrode assembly, the thickness of the third segment gradually decreases, and the change in thickness of the third segment per unit length in the direction from the end cap to the electrode assembly is greater than the change in thickness of the second segment.

15. The battery cell according to claim 14, characterized in that, The first thickened portion further includes a fourth segment, which is connected to the third segment on the side away from the second segment along the first direction; Along the direction from the end cap to the electrode assembly, the thickness of the fourth segment gradually decreases, and the thickness change per unit length in the direction from the end cap to the electrode assembly is less than the thickness change of the third segment.

16. The battery cell according to claim 1, characterized in that, Along the first direction, the entire first thickened portion is located on the side of the first recess away from the end cap.

17. The battery cell according to claim 16, characterized in that, The first wall further includes a second thickened portion, which is disposed along a second direction with the first thickened portion, and the projection of the second thickened portion along the first direction does not overlap with the projection of the first recess along the first direction. The first direction, the second direction and the thickness direction are perpendicular to each other.

18. The battery cell according to claim 17, characterized in that, The first thickened portion is directly connected to the second thickened portion.

19. The battery cell according to claim 17, characterized in that, Along the first direction, the end of the first thickened portion away from the end cap is flush with the end of the second thickened portion away from the end cap.

20. The battery cell according to claim 17, characterized in that, The first wall includes a first end face and a second end face, the first recess is recessed relative to the second end face, the first end face is connected to the second end face and is used to define the first recess, and the projection of the second end face along the first direction does not overlap with the projection of the first recess along the first direction. The first thickened portion includes at least a portion of the first end face, and / or the second thickened portion includes at least a portion of the second end face.

21. The battery cell according to claim 16, characterized in that, There are multiple first recesses, and the multiple first recesses are spaced apart along the second direction, with the first direction, the second direction and the thickness direction being perpendicular to each other; There are multiple first thickened portions, and each first thickened portion is provided corresponding to each first recess.

22. The battery cell according to claim 21, characterized in that, At least a portion of the first recesses are disposed at both ends of the first wall along the second direction, wherein the first direction, the second direction, and the thickness direction are perpendicular to each other.

23. The battery cell according to claim 1, characterized in that, The first recess is located in the middle region of the first wall along the second direction, and the first direction, the second direction and the thickness direction are perpendicular to each other.

24. The battery cell according to claim 1, characterized in that, The projections of the first thickened portions of the two first walls along the thickness direction at least partially overlap.

25. The battery cell according to claim 1, characterized in that, The dimension of the first thickened portion along the thickness direction is 0.05mm-0.5mm.

26. The battery cell according to claim 25, characterized in that, The dimension of the first thickened portion along the thickness direction is 0.1mm-0.3mm.

27. The battery cell according to claim 1, characterized in that, The dimension of the first thickened portion along the first direction is 0.5mm-20mm.

28. The battery cell according to claim 27, characterized in that, The dimension of the first thickened portion along the first direction is 1mm-10mm.

29. The battery cell according to any one of claims 1-28, characterized in that, The end cap includes a first cover portion and a second cover portion. Along the first direction, the second cover portion is closer to the electrode assembly than the first cover portion, and the second cover portion is welded to the first thickened portion.

30. The battery cell according to claim 29, characterized in that, The battery cell also includes an electrode terminal, and the electrode assembly includes a tab. The electrode terminal is disposed on the second cover and electrically connected to the tab.

31. The battery cell according to claim 30, characterized in that, A second recess is formed on the side of the end cap facing the electrode assembly. Along the first direction, the second recess is disposed opposite to the first cover portion, and at least a portion of the electrode tab is accommodated in the second recess.

32. The battery cell according to claim 31, characterized in that, The projection of the electrode terminal along the second direction at least partially overlaps with the projection of the tab along the second direction, and the first direction, the second direction and the thickness direction are perpendicular to each other.

33. A battery device, characterized in that, It includes multiple battery cells as described in any one of claims 1-32.

34. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-32 or a battery device as described in claim 33, wherein the battery cell or the battery device is used to store or provide electrical energy.

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